CN102324567A - Lithium secondary battery and use therein nonaqueous electrolytic solution - Google Patents

Lithium secondary battery and use therein nonaqueous electrolytic solution Download PDF

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Publication number
CN102324567A
CN102324567A CN2011102544054A CN201110254405A CN102324567A CN 102324567 A CN102324567 A CN 102324567A CN 2011102544054 A CN2011102544054 A CN 2011102544054A CN 201110254405 A CN201110254405 A CN 201110254405A CN 102324567 A CN102324567 A CN 102324567A
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active material
electrolyte
negative pole
expression
compound
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宫城秀和
加藤竜一
横沟正和
宇尾野宏之
松本一志
佐藤智洋
古田土稔
中岛孝之
铃木仁
大岛裕之
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Mitsubishi Chemical Corp
Mitsubishi Kasei Corp
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Mitsubishi Kasei Corp
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The present invention provides a kind of lithium secondary battery; It comprises positive pole and negative pole and the nonaqueous electrolytic solution with specific composition and rerum natura; Said nonaqueous electrolytic solution contains at least a compound that is selected from the following substances; Its content is more than the 10ppm, and said material comprises: the compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that have the S-F key in the fluorosilane compounds of the cyclic siloxane compound of formula (1) expression, formula (2) expression, the compound of formula (3) expression, the molecule.This lithium secondary battery has high power capacity, long-life, high-output power.In the formula (1), R 1And R 2Be the organic group of carbon number 1～12, n is 3～10 integer; In the formula (2), R 3～R 5Be the organic group of carbon number 1～12, x is 1～3 integer, and p, q and r are respectively 0～3 integers, and 1≤p+q+r≤3; In the formula (3), R 6～R 8Be the organic group of carbon number 1～12, A is the group that is made up of H, C, N, O, F, S, Si and/or P.

Description

Lithium secondary battery and use therein nonaqueous electrolytic solution
The application be that October 19, application number in 2006 are 201010242620.8 the applying date, denomination of invention divides an application for the application of " lithium secondary battery and use therein nonaqueous electrolytic solution ".
Technical field
The present invention relates to lithium secondary battery and use therein nonaqueous electrolytic solution; In more detail; Relate to have the secondary lithium batteries nonaqueous electrolytic solution that contains special component and have specific composition and rerum natura can occlusion and emit the positive pole and the negative pole of lithium, and particularly cryogenic discharging characteristic excellence and capacity height, long-life, high lithium secondary battery and the use therein nonaqueous electrolytic solution of exporting.
Background technology
In recent years, be accompanied by the miniaturization of electronic equipment, the requirement of the high capacity of secondary cell is improved constantly, energy density receives publicity than nickel-cadmium cell and the high lithium secondary battery of Ni-MH battery.
Therefore lithium secondary battery can be used in the various uses owing to be the secondary cell of high power capacity, but it mainly uses in the battery of smaller types such as mobile phone, and expectation enlarges its application from now in the large-sized battery of car applications etc.In large-sized battery, particularly output there is requirement, just compact battery is in the past become also insufficient on performance greatly merely.In addition, the various modification methods (for example, with reference to patent documentation 1～25, non-patent literature 1 etc.) that are used to improve the battery material of output have been proposed., still can not obtain enough output, require further to improve.
Patent documentation 1: the spy opens the 2005-071749 communique
Patent documentation 2: the spy opens the 2005-123180 communique
Patent documentation 3: the spy opens the 2001-206722 communique
Patent documentation 4: the spy opens the 2003-267732 communique
Patent documentation 5: the spy opens the 2001-015108 communique
Patent documentation 6:WO2003/34518 communique
Patent documentation 7: the spy opens flat 11-067270 communique
Patent documentation 8: the spy opens clear 61-168512 communique
Patent documentation 9: the spy opens flat 6-275263 communique
Patent documentation 10: the spy opens the 2000-340232 communique
Patent documentation 11: the spy opens the 2005-235397 communique
Patent documentation 12: the spy opens flat 11-031509 communique
Patent documentation 13: the spy opens flat 3-055770 communique
Patent documentation 14: the spy opens the 2004-071458 communique
Patent documentation 15: the spy opens the 2004-087459 communique
Patent documentation 16: the spy opens flat 10-270074 communique
Patent documentation 17: the spy opens the 2002-075440 communique
Patent documentation 18: the spy opens flat 10-270075 communique
Patent documentation 19: the spy opens flat 8-045545 communique
Patent documentation 20: the spy opens the 2001-006729 communique
Patent documentation 21: the spy opens flat 10-050342 communique
Patent documentation 22: the spy opens flat 9-106835 communique
Patent documentation 23: the spy opens the 2000-058116 communique
Patent documentation 24: the spy opens the 2001-015158 communique
Patent documentation 25: the spy opens the 2005-306619 communique
Non-patent literature 1:J.Electrochem.soc., 145, L1 (1998)
Summary of the invention
The problem that invention will solve
The present invention is in view of such background technology and making, and it also is high power capacity, long-life and the lithium secondary battery with high output processing when more large-scale that its problem is to provide a kind of.
Solve the method for problem
The inventor etc. further investigate above-mentioned problem; The result finds; Have the positive pole and the negative pole of specific composition and rerum natura and the nonaqueous electrolytic solution that contains the compound of from specific group, selecting through use; Can obtain the lithium secondary battery of high power capacity, long-life and high output, thereby accomplish the present invention.
Promptly; The present invention provides a kind of lithium secondary battery, and this lithium secondary battery comprises at least: between positive pole and negative pole, clip the micro-porous film dividing plate and the electrode group that constitutes and in nonaqueous solvents, contain lithium salts and the nonaqueous electrolytic solution that forms, and they are contained in the battery case; Wherein
Said positive pole and said negative pole form active material layer respectively on collector body, this active material layer contains can occlusion and emit the active material of lithium ion;
This nonaqueous electrolytic solution contains at least a compound that is selected from the following substances, and its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises:
The cyclic siloxane compound of formula (1) expression,
[Chemical formula 1]
Figure BDA0000087738240000031
[in the general formula (1), R 1And R 2Can be the same or different, the organic group of expression carbon number 1～12, n representes 3～10 integer.]
The fluorosilane compounds of formula (2) expression,
[Chemical formula 2]
SiF xR 3 pR 4 qR 5 r (2)
[in the general formula (2), R 3～R 5Can be the same or different, the organic group of expression carbon number 1～12, x representes 1～3 integer, p, q and r represent 0～3 integer respectively, and 1≤p+q+r≤3.]
The compound of formula (3) expression,
[chemical formula 3]
Figure BDA0000087738240000032
[in the general formula (3), R 6～R 8Can be the same or different, the organic group of expression carbon number 1～12, A representes the group that is made up of H, C, N, O, F, S, Si and/or P.], and
The compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that have the S-F key in the molecule;
And said positive pole is any one positive pole that is selected from following positive pole [1]～positive pole [5]:
Anodal [1]: comprise the positive pole of positive active material, this positive active material contains manganese;
Anodal [2]: comprise the positive pole of positive active material, this positive active material has the composition of following composition formula (4) expression,
Li xNi (1-y-z)Co yM zO 2Composition formula (4)
[in the composition formula (4), M representes to be selected from least a element among Mn, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤1.2, and y representes to satisfy the number of 0.05≤y≤0.5, and z representes to satisfy the number of 0.01≤z≤0.5.]；
Anodal [3]: comprise the positive pole that is selected from any positive active material in following (a)～(d),
(a) the BET specific area is 0.4m 2/ g～2m 2The positive active material of/g
(b) average primary particle diameter is the positive active material of 0.1 μ m～2 μ m
(c) median particle diameter d 50It is the positive active material of 1 μ m～20 μ m
(d) tap density is 1.3g/cm 3～2.7g/cm 3Positive active material;
Anodal [4]: satisfy the positive pole of any condition in following (e)～(f) that is selected from,
(e) on collector body, form the positive pole that contains the positive electrode active material layer of positive active material, electric conducting material and adhesive and make, wherein, the content of the electric conducting material in the positive electrode active material layer is the scope of 6 quality %～20 quality %
(f) on collector body, form the positive pole that contains the positive electrode active material layer of positive active material and adhesive and make, wherein, the density of positive electrode active material layer is 1.7g/cm 3～3.5g/cm 3Scope
(g) on collector body, form the positive pole that contains the positive electrode active material layer of positive active material and adhesive and make; Wherein, the value of the ratio of the thickness of positive electrode active material layer and collector body (injecting the thickness of a nonaqueous electrolytic solution side active material layer before)/(thickness of collector body) is 1.6～20;
Anodal [5]: contain and form the different positive poles of positive active material more than 2 kinds.
In addition; The present invention provides a kind of lithium secondary battery, and this lithium secondary battery comprises at least: between positive pole and negative pole, clip the micro-porous film dividing plate and the electrode group that constitutes and in nonaqueous solvents, contain lithium salts and the nonaqueous electrolytic solution that forms, and they are contained in the battery case; Wherein
Said positive pole and said negative pole form active material layer respectively on collector body, this active material layer contains can occlusion and emit the active material of lithium ion;
This nonaqueous electrolytic solution contains at least a compound that is selected from the following substances; And its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises: the compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that have the S-F key in the fluorosilane compounds of the cyclic siloxane compound of above-mentioned general formula (1) expression, above-mentioned general formula (2) expression, the compound of above-mentioned general formula (3) expression, the molecule;
And said negative pole is any one negative pole that is selected from following negative pole [1]～negative pole [10]:
Negative pole [1]: contain crystallinity is different more than 2 kinds carbonaceous material negative pole as negative electrode active material;
Negative pole [2]: contain the negative pole of amorphous carbonaceous as negative electrode active material; Said amorphous carbonaceous is more than the 0.337nm through the interplanar distance (d002) of (002) face that wide-angle x-ray diffraction is measured; Crystallite size (Lc) is below the 80nm, adopt that the argon laser Raman spectroscopy measures with 1360cm -1Peak intensity with respect to 1580cm -1The Raman R value of ratio definition of peak intensity be more than 0.2;
Negative pole [3]: contain the negative pole of metal oxide as negative electrode active material, said metal oxide contains can occlusion and emit the titanium of lithium;
Negative pole [4]: contain the negative pole of carbonaceous material as negative electrode active material, the circularity of said carbonaceous material is more than 0.85, and surface functional group amount O/C value is 0～0.01;
Negative pole [5]: contain the negative pole of different orientation carbon complex as negative electrode active material, said different orientation carbon complex contains the different carbonaceous material of orientation more than 2 kinds;
Negative pole [6]: contain the negative pole of graphite matter carbon particle as negative electrode active material; The circularity of said graphite matter carbon particle is more than 0.85; The interplanar distance (d002) of (002) face of measuring through wide-angle x-ray diffraction is lower than 0.337nm, adopt that the argon laser Raman spectroscopy measures with 1360cm -1Peak intensity with respect to 1580cm -1The Raman R value of ratio definition of peak intensity be 0.12～0.8;
Negative pole [7]: contain the negative pole of the following negative electrode active material that comprises multielement (C) as negative electrode active material; The said negative electrode active material (C) that comprises multielement contains at least a in the lithium occlusion metal (A) that is selected from Al, Pb, Zn, Sn, Bi, In, Mg, Ga, Cd, Ag, Si, B, Au, Pt, Pd and Sb and/or the lithium occlusion alloy (B), and contains C and/or N as element Z;
Negative pole [8]: contain the negative pole of the negative electrode active material more than 2 kinds of different in kind as negative electrode active material;
Negative pole [9]: containing tap density is 0.1g/cm 3More than, and the micropore volume of the particle that is equivalent to diameter 0.01 μ m～1 mu m range of employing mercury porosimeter mensuration is the negative pole of the above negative electrode active material of 0.01mL/g;
Negative pole [10]: be charged to 60% o'clock of nominal capacity of this negative pole, the reaction resistance that is produced by the opposed battery of negative pole is the negative pole below 500 Ω.
In addition; The present invention provides a kind of lithium secondary battery, and this lithium secondary battery comprises at least: anodal and negative pole are clipped the micro-porous film dividing plate and the electrode group that constitutes and in nonaqueous solvents, contain lithium salts and the nonaqueous electrolytic solution that forms, and they are contained in the battery case; Wherein
Said positive pole and said negative pole form active material layer respectively on collector body, this active material layer contains can occlusion and emit the active material of lithium ion;
This nonaqueous electrolytic solution contains at least a compound that is selected from the following substances; And its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises: the compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that have the S-F key in the fluorosilane compounds of the cyclic siloxane compound of above-mentioned general formula (1) expression, above-mentioned general formula (2) expression, the compound of above-mentioned general formula (3) expression, the molecule;
And said nonaqueous electrolytic solution is the electrolyte that satisfies the arbitrary condition in following electrolyte [1]～electrolyte [9] that is selected from:
Electrolyte [1]: the nonaqueous solvents that constitutes electrolyte is the mixed solvent that contains ethylene carbonate at least, and ethylene carbonate is 1 capacity %～25 capacity % with respect to the ratio of nonaqueous solvents total amount;
Electrolyte [2]: the nonaqueous solvents that constitutes electrolyte contains at least a asymmetric linear carbonate, and this asymmetric linear carbonate is shared in whole nonaqueous solventss, and to contain proportional be 5 volume %～90 volume %;
Electrolyte [3]: the nonaqueous solvents that constitutes electrolyte contains at least a chain carboxylate;
Electrolyte [4]: it is the solvent more than 70 ℃ that the nonaqueous solvents of formation electrolyte contains flash-point, and its content is more than the 60 capacity % of whole nonaqueous solventss;
Electrolyte [5]: contain LiN (C nF 2n+1SO 2) 2(in the formula, n is 1～4 integer) and/or two (oxalate closes) lithium borate are as the lithium salts that constitutes electrolyte;
Electrolyte [6]: the lithium salts that constitutes electrolyte is fluorine-containing lithium salts, and in whole nonaqueous electrolytic solutions, contains the hydrogen fluoride (HF) of 10ppm～300ppm;
Electrolyte [7]: in electrolyte, contain vinylene carbonate, the content of this vinylene carbonate is the scope of the 0.001 quality %～3 quality % of electrolyte gross mass;
Electrolyte [8]: in electrolyte, also contain at least a compound in the compound that is selected from formula (4) expression, the heterocyclic compound that contains nitrogen and/or sulphur, cyclic carboxylic esters, the fluorine-containing cyclic carbonate; Its content in whole nonaqueous electrolytic solutions is the scope of 0.001 quality %～5 quality %
[chemical formula 4]
Figure BDA0000087738240000061
[in the general formula (4), R 9～R 12Can be the same or different the group that expression is made up of at least a element that is selected among H, C, N, O, F, S and the P.]；
Electrolyte [9]: in electrolyte, also containing overcharges prevents agent.
In above-mentioned secondary cell, especially preferably have the secondary cell that is selected from any character in following (1)～(3),
(1) the electrode area summation of positive pole is more than 20 times with respect to the area ratio of the surface area of the shell of secondary cell;
(2) DC resistance component of secondary cell is below 20 milliohms (m Ω);
(3) being contained in the electric capacity that the battery key element in the battery case of secondary cell had is more than 3 ampere-hours (Ah).
In addition; The present invention provides a kind of lithium secondary battery, and this lithium secondary battery comprises at least: anodal and negative pole are clipped the micro-porous film dividing plate and the electrode group that constitutes and in nonaqueous solvents, contain lithium salts and the nonaqueous electrolytic solution that forms, and they are contained in the battery case; Wherein
Said positive pole and said negative pole form active material layer respectively on collector body, this active material layer contains can occlusion and emit the active material of lithium ion;
This nonaqueous electrolytic solution contains at least a compound that is selected from the following substances; And its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises: the compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that have the S-F key in the fluorosilane compounds of the cyclic siloxane compound of above-mentioned general formula (1) expression, above-mentioned general formula (2) expression, the compound of above-mentioned general formula (3) expression, the molecule;
And this secondary cell has any character that is selected from following structure [1]～structure [6]:
Structure [1]: the electrode area summation of said positive pole is more than 20 times with respect to the area ratio of the surface area of the shell of said secondary cell;
Structure [2]: the DC resistance component of said secondary cell is below 20 milliohms (m Ω);
Structure [3]: being contained in the electric capacity that the battery key element in the battery case of said secondary cell had is more than 3 ampere-hours (Ah);
Structure [4]: the positive pole of said secondary cell and the collector body of negative pole are processed by metal material respectively, and the metal material of said collector body be used for that electric current is fetched into outside electric conductor and weld through any method of slot welding, high-frequency welding or ultrasonic bonding;
Structure [5]: the shell of said secondary cell is an aluminum or aluminum alloy;
Structure [6]: the sheathing material of the above-mentioned battery case of formation of said secondary cell is following sheathing material: at least a portion of the inner face side of battery comprises the sheet material that uses thermoplastic resin and form; When holding said battery pack, can also seal each other and said battery pack is sealed through making said thermoplastic resin.
In addition, the present invention also provides a kind of secondary cell to use nonaqueous electrolytic solution, and this nonaqueous electrolytic solution comprises nonaqueous solvents and lithium salts at least, wherein,
This nonaqueous electrolytic solution contains at least a compound that is selected from the following substances; And its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises: the compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that have the S-F key in the fluorosilane compounds of the cyclic siloxane compound of above-mentioned general formula (1) expression, above-mentioned general formula (2) expression, the compound of above-mentioned general formula (3) expression, the molecule;
And said nonaqueous electrolytic solution satisfies the arbitrary condition in following electrolyte [1]～electrolyte [9] that is selected from:
Electrolyte [1]: the nonaqueous solvents that constitutes electrolyte is the mixed solvent that contains ethylene carbonate at least, and ethylene carbonate is 1 capacity %～25 capacity % with respect to the ratio of nonaqueous solvents total amount;
Electrolyte [2]: the nonaqueous solvents that constitutes electrolyte contains at least a asymmetric linear carbonate, and this asymmetric linear carbonate is shared in whole nonaqueous solventss, and to contain proportional be 5 volume %～90 volume %;
Electrolyte [3]: the nonaqueous solvents that constitutes electrolyte contains at least a chain carboxylate;
Electrolyte [4]: it is the solvent more than 70 ℃ that the nonaqueous solvents of formation electrolyte contains flash-point, and its content is more than the 60 capacity % of whole nonaqueous solventss;
Electrolyte [5]: contain LiN (C nF 2n+1SO 2) 2(in the formula, n is 1～4 integer) and/or two (oxalate closes) lithium borate are as the lithium salts that constitutes electrolyte;
Electrolyte [6]: the lithium salts that constitutes electrolyte is fluorine-containing lithium salts, and in whole nonaqueous electrolytic solutions, contains the hydrogen fluoride (HF) of 10ppm～300ppm;
Electrolyte [7]: in electrolyte, contain vinylene carbonate, and the content of this vinylene carbonate is the scope of the 0.001 quality %～3 quality % of electrolyte gross mass;
Electrolyte [8]: in electrolyte, also contain at least a compound in the compound that is selected from above-mentioned general formula (4) expression, the heterocyclic compound that contains nitrogen and/or sulphur, cyclic carboxylic esters, the fluorine-containing cyclic carbonate, and its content in whole nonaqueous electrolytic solutions is the scope of 0.001 quality %～5 quality %;
Electrolyte [9]: in electrolyte, also containing overcharges prevents agent.
The effect of invention
According to the present invention, can provide cryogenic discharging characteristic particularly excellent lithium secondary battery, the variety of way of the invention through the back narration can be brought into play the effect that for example is described below.
Anodal [1]:
According to the present invention, can obtain long-life, high output with more cheap material, therefore the lithium secondary battery of the large-sized battery that is specially adapted to car applications for example etc. can be provided.
Anodal [2]:
According to the present invention, high power capacity can be provided and have the lithium secondary battery of long-life, high output, the lithium secondary battery of the large-sized battery that is specially adapted to car applications for example etc. can also be provided.
Anodal [3]:
According to the present invention, can obtain the lithium secondary battery of long-life, high output, therefore the lithium secondary battery of the large-sized battery that is specially adapted to car applications for example etc. can be provided.
Anodal [4]:
According to the present invention, can obtain the lithium secondary battery of high output, therefore the lithium secondary battery of the large-sized battery that is specially adapted to car applications for example etc. can be provided.
Anodal [5]:
According to the present invention; Can obtain high power capacity, long-life, high output; And suppressed lithium secondary battery, therefore the lithium secondary battery of the large-sized battery that is specially adapted to car applications for example etc. can be provided because of the reduction (repeated charge characteristic (cycle characteristics) excellence) of carrying out battery capacity that discharging and recharging of battery cause and output repeatedly.
Negative pole [1]:
According to the present invention; The lithium secondary battery that is particularly suitable for as large-sized battery can be provided; The effect that this lithium secondary battery can keep cycle characteristics to improve; Simultaneously can all keep high output characteristic in circulation initial stage to latter stage,, also can keep the output characteristic under high-power even after the deterioration after carrying out charge and discharge cycles.
Negative pole [2]:
According to the present invention, can provide short time high current density charge-discharge characteristic good lithium secondary battery.
Negative pole [3]:
According to the present invention, can provide output resistance little, and can effectively utilize the lithium secondary battery of energy.
Negative pole [4]:
According to the present invention, the high temperature that can be provided under the low depth of charge is preserved the lithium secondary battery that patience is improved.
Negative pole [5]:
According to the present invention, also can keep the lithium secondary battery of superperformance when can be provided in discharging and recharging for a long time repeatedly under the low depth of charge.
Negative pole [6]:
According to the present invention, recover the fast lithium secondary battery of output from low output state in the time of can low temperature being provided.
Negative pole [7]:
According to the present invention, it is also big to can be provided in the capacity of processing when more large-scale, and the good lithium secondary battery of charging acceptance.
Negative pole [8]:
According to the present invention, can provide the output of cycle characteristics and low temperature all good lithium secondary battery.
Negative pole [9] [10]:
According to the present invention, can be provided in that battery is processed when more large-scale the circulation conservation rate is also big, and can realize good battery life, even after the charge and discharge cycles test, also can realize high output, the perhaps lithium secondary battery of both.
Electrolyte [1]:
According to the present invention, can significantly improve the low-temperature characteristics of rechargeable nonaqueous electrolytic battery, in more detail, cycle characteristics and preservation characteristics are worsened and the raising low-temperature characteristics.
Electrolyte [2]:
According to the present invention, can provide secondary cell that cycle characteristics and low-temperature characteristics significantly improve simultaneously with nonaqueous electrolytic solution and the secondary cell that uses the above-mentioned excellent performance of this nonaqueous electrolytic solution.
Electrolyte [3]:
According to the present invention, can provide secondary cell that the low temperature output characteristic is largely increased with nonaqueous electrolytic solution and secondary cell.
Electrolyte [4]:
According to the present invention; Can provide following secondary cell with nonaqueous electrolytic solution and secondary cell: although this secondary cell with nonaqueous electrolytic solution be evaporation owing to solvent make salt out or flash-point reduces, at high temperature in the pressure-volume few electrolyte of problem that when containing a large amount of low viscosity solvent, produces such as be prone to rise form, but still can keep high low-temperature characteristics and output characteristic.
Electrolyte [5]:
According to the present invention, can provide output characteristic significantly to improve, and the secondary cell of high temperature preservation characteristics and cycle characteristics excellence is with nonaqueous electrolytic solution and secondary cell.
Electrolyte [6]:
According to the present invention, can provide high temperature preservation characteristics and cycle characteristics excellent, and the secondary cell that output characteristic significantly improves is used nonaqueous electrolytic solution.
Electrolyte [7]:
According to the present invention, the secondary cell that can provide cycle characteristics and low-temperature characteristics significantly to improve simultaneously.
Electrolyte [8]:
According to the present invention, can provide cryogenic discharging characteristic significantly to improve, and the secondary cell of high temperature preservation characteristics and cycle characteristics excellence is with nonaqueous electrolytic solution and secondary cell.
Electrolyte [9]:
According to the present invention, the secondary cell of the fail safe when satisfying high speed characteristic simultaneously and overcharging can be provided.
Structure [1]～[5]:
According to the present invention, can obtain high power capacity, long-life, high output, and when overcharging the also high lithium secondary battery of fail safe, therefore, the lithium secondary battery of the large-sized battery that is specially adapted to car applications for example etc. can be provided.
Structure [6]:
According to the present invention, can obtain high power capacity, long-life, high output, and it is few to produce gas, even when overcharging the also high lithium secondary battery of fail safe, therefore, the lithium secondary battery of the large-sized battery that is specially adapted to car applications for example etc. can be provided.
Embodiment
Specify execution mode of the present invention below, but the explanation of the constitutive requirements of record is an example (typical example) of execution mode of the present invention below, otherwise exceed its main points, then the present invention is not limited to these concrete contents.
Lithium secondary battery of the present invention comprises at least: anodal and negative pole clipped the micro-porous film dividing plate and the electrode group that constitutes and in nonaqueous solvents, contain lithium salts and the nonaqueous electrolytic solution that forms, and they is contained in the battery case, wherein,
Said positive pole and said negative pole form active material layer respectively on collector body, this active material layer contains can occlusion and emit the active material of lithium ion;
This nonaqueous electrolytic solution contains at least a compound (following they are abbreviated as " specific compound ") that is selected from the following substances; And its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises: the compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that have the S-F key in the fluorosilane compounds of the cyclic siloxane compound of above-mentioned general formula (1) expression, above-mentioned general formula (2) expression, the compound of above-mentioned general formula (3) expression, the molecule;
And said positive pole, negative pole, electrolyte or battery structure satisfy certain conditions.
Below, lithium secondary battery of the present invention is described in more detail.
< positive pole >
Describe in the face of the positive pole that uses in the lithium secondary battery of the present invention down.
The positive pole that uses among the present invention so long as form contain can occlusion and the positive pole of the active material layer of the active material of emitting lithium ion get final product, do not limit especially, this positive pole is preferably selected from any one positive pole in following positive pole [1]～positive pole [5]:
Anodal [1]: comprise the positive pole of positive active material, this positive active material contains manganese;
Anodal [2]: comprise the positive pole of positive active material, this positive active material has the composition of following composition formula (4) expression,
Li xNi (1-y-z)Co yM zO 2Composition formula (4)
[in the composition formula (4), M representes to be selected from least a element among Mn, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤1.2, and y representes to satisfy the number of 0.05＜y≤0.5, and z representes to satisfy the number of 0.01≤z≤0.5.]；
Anodal [3]: comprise the positive pole that is selected from any positive active material in following (a)～(d),
(a) the BET specific area is 0.4m 2/ g～2m 2The positive active material of/g
(b) average primary particle diameter is the positive active material of 0.1 μ m～2 μ m
(c) median particle diameter d 50It is the positive active material of 1 μ m～20 μ m
(d) tap density is 1.3g/cm 3～2.7g/cm 3Positive active material;
Anodal [4]: satisfy the positive pole of any condition in following (e)～(f) that is selected from,
(e) this positive pole is on collector body, to form the positive pole that contains the positive electrode active material layer of positive active material, electric conducting material and adhesive and make, and wherein, the content of the electric conducting material in the positive electrode active material layer is the scope of 6 quality %～20 quality %
(f) this positive pole is on collector body, to form the positive pole that contains the positive electrode active material layer of positive active material and adhesive and make, and wherein, the density of positive electrode active material layer is 1.7g/cm 3～3.5g/cm 3Scope
(g) this positive pole is on collector body, to form the positive pole that contains the positive electrode active material layer of positive active material and adhesive and make; Wherein, the value of the ratio of the thickness of positive electrode active material layer and collector body (injecting the thickness of a nonaqueous electrolytic solution side active material layer before)/(thickness of collector body) is 1.6～20 scope;
Anodal [5]: contain and form the different positive poles of positive active material more than 2 kinds.
Below, at first normally used positive pole in the lithium secondary battery of the present invention is described.
[positive active material]
Below normally used positive active material in the positive pole is described.
[[composition]]
As positive active material, so long as can get final product not special restriction with electrochemical means occlusion and the material of emitting lithium ion.The material that preferably contains lithium and at least a transition metal for example can be enumerated lithium-compound transition metal oxide, contain the transition metal phosphate cpd of lithium.
As the transition metal of lithium-compound transition metal oxide, preferred V, Ti, Cr, Mn, Fe, Co, Ni, Cu etc. as object lesson, can enumerate LiCoO 2Deng lithium-cobalt composite oxide; LiNiO 2Deng lithium-ni compound oxide; LiMnO 2, LiMn 2O 4, Li 2MnO 3Deng lithium-manganese composite oxide; Substitute the part of the transition metal atoms that forms these lithiums-compound transition metal oxide main body and the material that obtains etc. with other metals such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si.The object lesson of the material that obtains as substituting for example can be enumerated LiNi 0.5Mn 0.5O 2, LiNi 0.85Co 0.10Al 0.05O 2, LiNi 0.33Co 0.33Mn 0.33O 2, LiMn 1.8Al 0.2O 4, LiMn 1.5Ni 0.5O 4Deng.
As the transition metal of the transition metal phosphate cpd that contains lithium, preferred V, Ti, Cr, Mn, Fe, Co, Ni, Cu etc. as object lesson, for example can enumerate LiFePO 4, Li 3Fe 2(PO 4) 3, LiFeP 2O 7Deng the ferric phosphate class; LiCoPO 4Deng the cobalt phosphate class; Substitute the part of the transition metal atoms that forms these transition metal phosphate cpd main bodys that contain lithium and the material that obtains etc. with other metals such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si.
[[surface coats]]
In addition, preferably in the surface attachment of these positive active materials by forming different materials with the positive active material of core.As attached to the material on surface (below, abbreviate " surface attachment material " as), for example can enumerate oxides such as aluminium oxide, silica, titanium oxide, zirconia, magnesia, calcium oxide, boron oxide, antimony oxide, bismuth oxide; Sulfate such as lithium sulfate, sodium sulphate, potassium sulfate, magnesium sulfate, calcium sulfate, aluminum sulfate; Carbonate such as lithium carbonate, calcium carbonate, magnesium carbonate etc.
These surface attachment materials can be through following method attached to the positive active material surface, and said method comprises: for example, the surface attachment material is dissolved or suspended in the solvent, impregnation is added in the positive active material and carries out dry method again; Surface attachment material precursor is dissolved or suspended in the solvent, and impregnation is added in the positive active material again, waits the method that makes it to react through heating then; The surface attachment material is added in the positive active material precursor, carry out the method for sintering etc. simultaneously.
As the amount of surface attachment material, with respect to positive active material in mass, its lower limit is preferably more than the 0.1ppm, more preferably more than the 1ppm, further is preferably more than the 10ppm; Its upper limit is preferably below 20%, more preferably below 10%, further is preferably below 5%.Can suppress the oxidation reaction of nonaqueous electrolytic solution by the surface attachment material, thereby can improve battery life, but its adhesion amount is when very few on positive active material surface; Can not fully show its effect; And too much the time, owing to hinder the discrepancy of lithium ion, therefore impedance sometimes increases.
[[shape]]
The shape of particle of the positive active material among the present invention can be used in the past the bulk used, polyhedral, spherical, oval spherical, tabular, needle-like, column etc.; Wherein, Preferred primary particle cohesion and form offspring, and this offspring be shaped as spherical or oval spherical.Usually, electrochemical element is along with it discharges and recharges, and the active material in the electrode expands and shrinks, and therefore takes place easily because deteriorations such as the destruction of the active material that this stress causes or conductive path cut-outs.Therefore, compare with the single particle active material that is primary particle, preferred primary particle condenses and the situation of formation offspring, can relax the stress that expansion is shunk because form offspring, thus the deterioration of preventing.In addition; Compare with the particle of axle orientation such as tabular; Preferred spherical or oval spherical particle, because the spherical or oval spherical orientation of particle when electrode moulding is few, the expansion of the electrode when discharging and recharging is shunk also few; And when making electrode during with the mixing of conductive agent, also easy and uniform mixing.
[[tap density]]
The tap density of positive active material is generally 1.3g/cm 3More than, be preferably 1.5g/cm 3More than, 1.6g/cm more preferably 3More than, most preferably be 1.7g/cm 3More than.If the tap density of positive active material is lower than above-mentioned lower limit; Then when forming positive electrode active material layer; The decentralized medium amount that needs increases; The necessary amount of electric conducting material or adhesive increases simultaneously, and the filling rate of positive active material in positive electrode active material layer is restricted, and battery capacity is restricted sometimes.Through using the high composite oxide power of tap density, can form highdensity positive electrode active material layer.In general; Tap density is preferred more greatly more, does not have the special upper limit, if but tap density is too big; In the positive electrode active material layer with the nonaqueous electrolytic solution factor that the diffusion of the lithium ion of medium becomes decision speed then; Part throttle characteristics reduces sometimes easily, and therefore, tap density is generally 2.9g/cm 3Below, be preferably 2.7g/cm 3Below, 2.5g/cm more preferably 3Below.
In the present invention, tap density is as giving a definition: make test portion fall 20cm through the sieve of aperture 300 μ m 3Jolt ramming container (tapping cell) in; Be full of after the vessel volume; (for example use the powder density determination device; The Tap densor (タ Star プ デ Application サ one) that Seishin (セ イ シ Application) society of enterprise makes), carry out the vibration of 1000 length of stroke 10mm, the density that the volume with thus time the and the weight of test portion are obtained is as tap density.
[[median particle diameter d 50]]
The median particle diameter d of the particle of positive active material 50(primary particle cohesion and when forming offspring, be the offspring diameter) is generally more than the 0.1 μ m, is preferably more than the 0.5 μ m; More preferably more than the 1 μ m; Most preferably be more than the 3 μ m, its upper limit is generally below the 20 μ m, is preferably below the 18 μ m; More preferably below the 16 μ m, most preferably be below the 15 μ m.If median particle diameter d 50Be lower than above-mentioned lower limit; Then can not obtain the product of high-tap density sometimes; And if above the upper limit, then because the diffusion of the lithium in the particle needs the time, therefore producing battery performance sometimes reduces; Perhaps processing the positive pole of battery, when just slurryization is coated with into film like again in solvent with conductive agent or adhesive etc. with active material, producing problems such as striped.Here, has different median particle diameter d more than 2 kinds through mixing 50Positive active material, can further improve the fillibility of making when anodal.
In addition, the median particle diameter d among the present invention 50Can utilize known laser diffraction/diffuse transmission type particle size distribution device to measure.The LA-920 that uses the HORIBA manufactured is as the particle size distribution timing, and the decentralized medium that uses when measuring uses 0.1 quality % sodium hexametaphosphate solution, carry out 5 minutes ultrasonic dispersing after, set and measure refractive index 1.24 and measure.
[[average primary particle diameter]]
Primary particle cohesion and when forming offspring,, being generally more than the 0.01 μ m as the average primary particle diameter of positive active material; Be preferably more than the 0.05 μ m, more preferably more than the 0.08 μ m, most preferably be more than the 0.1 μ m; And be generally below the 3 μ m; Be preferably below the 2 μ m, more preferably below the 1 μ m, most preferably be below the 0.6 μ m.If average primary particle diameter surpasses the above-mentioned upper limit, then be difficult to form spherical offspring, the powder fillibility is brought harmful effect, perhaps specific area significantly reduces, and therefore, the possibility that battery performances such as output characteristic reduce uprises sometimes.On the contrary, if average primary particle diameter is lower than above-mentioned lower limit,, therefore produce the problems such as invertibity difference that discharge and recharge sometimes then usually because crystallization is incomplete.
In addition, primary particle size can be measured through the observation of using scanning electron microscopy (SEM).Particularly, obtain: in the photo of 10000 times of multiplying powers, 50 primary particles are arbitrarily obtained the greatest length of the section that the right sides boundary line by primary particle on the straight line of horizontal direction produces, and got its mean value through following method.
[[BET specific area]]
The BET specific area that offers the positive active material of lithium secondary battery of the present invention is generally 0.2m 2More than/the g, be preferably 0.3m 2More than/the g, 0.4m more preferably 2More than/the g, its upper limit is generally 4.0m 2Below/the g, be preferably 2.5m 2Below/the g, 1.5m more preferably 2Below/the g.If the BET specific area is littler than this scope, then battery performance reduces easily, and if the BET specific area is bigger than this scope, then tap density is difficult to improve, and is easy to generate problem sometimes on the coating when forming positive active material.
The BET specific area is defined as following value: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation 150 ℃ to test portion carry out 30 minutes predrying; Using then and correctly being adjusted into nitrogen is 0.3 nitrogen helium gas mixture body with respect to atmospheric relative pressure value, the value of measuring through the nitrogen absorption BET1 point method that adopts the gas flow method to carry out.
[[autofrettage]]
As the autofrettage of positive active material, use usual way as the autofrettage of inorganic compound.Particularly when making spherical or oval spherical active material; Can consider the whole bag of tricks; Method for example can be listed below: the raw material dissolving of transition metal raw material such as transition metal nitrate, transition metal sulfate and other elements of using as required or grinding dispersion in the water equal solvent, are regulated pH while stirring, make and obtain spherical precursor; After being dried as required, add LiOH, Li 2CO 3, LiNO 3In the Li source, sintering and obtain the method for active material at high temperature; With the raw material dissolving of transition metal raw material such as transition metal nitrate, transition metal sulfate, transition metal hydroxide, transition metal oxide and other elements of using as required or grinding dispersion in the water equal solvent; Be dried moulding through spray dryer etc. again; Process spherical or oval spherical precursor, add LiOH, Li then therein 2CO 3, LiNO 3In the Li source, sintering and obtain the method for active material at high temperature; And with transition metal raw materials such as transition metal nitrate, transition metal sulfate, transition metal hydroxide, transition metal oxide and LiOH, Li 2CO 3, LiNO 3Deng the raw material dissolving of Li source and other elements of using as required or grinding dispersion in the water equal solvent; Be dried moulding through spray dryer etc. again; Process spherical or oval spherical precursor, at high temperature its sintering is obtained the method for active material etc. then.
[anodal structure]
Below, the structure of the positive pole that uses among the present invention is narrated.
[[electrode structure and facture]]
The positive pole that uses in the lithium secondary battery of the present invention forms the positive electrode active material layer that contains positive active material and adhesive and makes on collector body.Use the manufacturing of the positive pole of positive active material to carry out according to usual way.That is,, process sheet with positive active material and adhesive and dry mixed such as electric conducting material that uses as required and thickener; Again the tablet that obtains is pressed and be bonded on the positive electrode collector; Perhaps with these material dissolves or be dispersed in the liquid medium, process slurry, be coated on this slurry on the positive electrode collector again and carry out drying; Positive electrode active material layer can be on collector body, formed thus, thereby positive pole can be obtained.
In the present invention, the content of the positive active material in the positive electrode active material layer is generally more than the 10 quality %, is preferably more than the 30 quality %, is preferably especially more than the 50 quality %.In addition, its upper limit is generally below the 99.9 quality %, is preferably below the 99 quality %.If the content of the positive electrode active material powder in the positive electrode active material layer is very low, then electric capacity becomes insufficient sometimes.If opposite too high levels, then anodal intensity is not enough sometimes.In addition, positive active material can use a kind of separately, also can form the positive active materials more than 2 kinds different or that powder property is different with ratio combination use with combination arbitrarily.
[[compacting]]
In order to improve the packed density of positive active material, preferably utilize hand press, roll squeezer etc. to carry out compacting through coating, the dry positive electrode active material layer that obtains.The lower limit of the density of positive electrode active material layer is preferably 1g/cm 3More than, 1.5g/cm more preferably 3More than, further be preferably 2g/cm 3More than, its upper limit is preferably 4g/cm 3Below, 3.5g/cm more preferably 3Below, further be preferably 3g/cm 3Following scope.If surpass this scope, then near the permeability of nonaqueous electrolytic solution collector body/reactive species interface reduces, and particularly the charge-discharge characteristic under high current density reduces sometimes.In addition, if be lower than this scope, then the conductivity between active material reduces, and battery impedance increases sometimes.
[[electric conducting material]]
As electric conducting material, can use known electric conducting material arbitrarily.As concrete example, can enumerate metal materials such as copper, nickel; Graphite such as native graphite, Delanium; Carbon blacks such as acetylene black; Material with carbon elements such as amorphous carbon such as needle coke etc.These materials can use a kind of separately, also can use more than 2 kinds with combination and ratio combination arbitrarily.
The usage ratio of electric conducting material in positive electrode active material layer is generally more than the 0.01 weight %; Be preferably more than the 0.1 weight %, more preferably more than the 1 weight %, its upper limit is generally below the 50 weight %; Be preferably below the 30 weight %, more preferably below the 15 weight %.If content is lower than this scope, then conductivity is insufficient sometimes.Otherwise if content is higher than this scope, then battery capacity reduces sometimes.
[[adhesive]]
As the adhesive that when making positive electrode active material layer, uses; Not special the qualification; When using rubbing method; So long as solubilized or the material that is dispersed in the liquid medium that uses when electrode is made get final product,, can enumerate resinae macromolecules such as polyethylene, polypropylene, PETG, polymethyl methacrylate, aromatic polyamide, cellulose, NC Nitroncellulose as object lesson; Rubber-like macromolecules such as SBR (SBR styrene butadiene rubbers), NBR (acrylonitrile-butadiene rubber), fluorubber, isoprene rubber, butadiene rubber, ethylene-propylene rubber; Thermoplastic elastomer (TPE) shape macromolecules such as SBS or its hydrogenation thing, EPDM (ethylene-propylene-diene terpolymers), styrene-ethylene-butadiene vinyl copolymer, SIS or its hydrogenation thing; Syndiotactic 1, soft resinous macromolecules such as 2-polybutadiene, polyvinyl acetate, vinyl-vinyl acetate copolymer, propylene-alpha-olefin copolymers; Kynoar (PVdF), polytetrafluoroethylene, fluoridize fluorine family macromolecules such as Kynoar, polytetrafluoroethylene-ethylene copolymer; Polymeric composition etc. with ionic conductivity of alkali metal ion (particularly lithium ion).In addition, these materials can use a kind of separately, also can use more than 2 kinds with combination and ratio combination arbitrarily.
The ratio of adhesive in positive electrode active material layer is generally more than the 0.1 quality %, is preferably more than the 1 quality %, more preferably more than the 3 quality %; Its upper limit is generally below the 80 quality %; Be preferably below the 60 quality %, more preferably below the 40 quality %, most preferably below the 10 quality %.If the ratio of adhesive is too low, then can not fully keep positive active material, anodal mechanical strength is not enough, and battery performances such as cycle characteristics worsen.On the other hand, if the ratio of adhesive is too high, then cause battery capacity or conductivity to reduce sometimes.
[[liquid medium]]
As the liquid medium that is used to form slurry; So long as can dissolve or disperse positive active material, conductive agent, adhesive and the solvent of the thickener that uses as required; Its kind is just not special to be limited, and can use in water solvent and the organic solvent any.
As water-medium, for example can enumerate the mixed solvent of water, alcohol and water etc.As organic solvent, for example can enumerate aliphatic hydrocarbons such as hexane; Benzene,toluene,xylene, methyl naphthalene etc. are aromatic hydrocarbon based; Heterocyclic compound such as quinoline, pyridine; Ketones such as acetone, MEK, cyclohexanone; Ester such as methyl acetate, methyl acrylate class; Diethylenetriamines, N, amines such as N-dimethylamino propylamine; Ether, expoxy propane, oxolane ethers such as (THF); Amide-types such as N-methyl pyrrolidone (NMP), dimethyl formamide, dimethylacetylamide; Aprotic polar solvents such as hexamethyl phosphonic amide, methyl-sulfoxide etc.
Particularly when using water solvent, preferably use the latex of thickener and SBR styrene butadiene rubbers (SBR) etc. carry out slurryization.Thickener normally is used to regulate the viscosity of slurry to be used.As thickener, not special restriction particularly, can be enumerated carboxymethyl cellulose, methylcellulose, CMC, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and their salt etc.They can use a kind of separately, also can use more than 2 kinds with combination and ratio combination arbitrarily.In addition, when adding thickener, thickener is generally more than the 0.1 quality % with respect to the ratio of active material; Be preferably more than the 0.5 quality %, more preferably more than the 0.6 quality %, its upper limit is generally below the 5 quality %; Be preferably below the 3 quality %, more preferably the scope below the 2 quality %.If be lower than this scope, then coating significantly reduces sometimes.And if surpass this scope, then active material shared ratio in positive electrode active material layer reduces, and produces the problem that problem that the capacity of battery reduces or the impedance between positive active material increase sometimes.
[[collector body]]
As the material of positive electrode collector, material known can be at random used in not special restriction.As object lesson, can enumerate metal materials such as aluminium, stainless steel, nickel plating, titanium, tantalum; Material with carbon element such as carbon cloth, carbon paper.Wherein, preferred metal materials, preferred especially aluminium.
As the shape of collector body, under the situation of metal material, can enumerate metal forming, metal cylinder, wire coil, metallic plate, metallic film, expansion alloy (エ キ ス パ Application De メ タ Le), perforated metal, foaming metal etc.; Under the situation of material with carbon element, can enumerate carbon plate, carbon film, carbon cylinder etc.In the middle of these, the preferable alloy film.In addition, film can also suitably form netted.The thickness of film is arbitrarily, but is generally more than the 1 μ m, is preferably more than the 3 μ m, more preferably more than the 5 μ m, and is generally below the 1mm, is preferably below the 100 μ m, more preferably below the 50 μ m.If film is thinner than this scope, then the necessary strength as collector body is not enough sometimes.On the contrary, if film is thicker than this scope, then damage operability sometimes.
The ratio of the thickness of collector body and positive electrode active material layer does not have special qualification; (injecting the active material layer thickness of a nonaqueous electrolytic solution side before)/(thickness of collector body) is preferably below 150; More preferably below 20, most preferably be below 10, its lower limit is preferably more than 0.1; More preferably more than 0.4, most preferably be the scope more than 1.If surpass this scope, then when high current density discharged and recharged, collector body produced heating sometimes because of Joule heat.If be lower than this scope, then collector body is with respect to the volume ratio increase of positive active material sometimes, and the capacity of battery reduces.
[[electrode area]]
When using nonaqueous electrolytic solution of the present invention, from height output and the viewpoint of the stability when improving high temperature, the area of preferred positive electrode active material layer is bigger than the external surface area of battery case.Particularly, the electrode area summation of above-mentioned positive pole, is preferably more than 15 times, more preferably more than 40 times in the area ratio with respect to the surface area of the shell of secondary cell.The external surface area of so-called shell under the situation that end square configuration is arranged, is meant the gross area of being obtained by the size calculating of length and width and thickness except the housing parts that is filled with the generating key element of the jut of terminal.Under the situation that the round-ended cylinder shape is arranged, be that the housing parts that is filled with the generating key element except the jut of terminal is approximately cylinder and the geometrical surface that obtains.The summation of the electrode area of so-called positive pole; It is geometrical surface with the opposed anodal plied timber layer of the plied timber layer that comprises negative electrode active material (closing material
Figure BDA0000087738240000191
); Form in the structure of anodal plied timber layer on the two sides clipping the collector body paper tinsel, be meant the summation of the area that calculates each face respectively.
[[discharge capacity]]
When using secondary cell of the present invention to use nonaqueous electrolytic solution; Be contained in electric capacity (electric capacity when battery is discharged to discharge condition by fully charged state) that the battery key element in the battery case of 1 secondary cell had if be more than 3 ampere-hours (Ah); Then the raising effect of cryogenic discharging characteristic becomes big, so preferred.
Therefore, positive plate is preferably designed to that discharge capacity is more than 3 ampere-hours (Ah) and is lower than 20Ah when completely charging, and more preferably 4Ah is above and be lower than 10Ah.When being lower than 3Ah, when taking out big electric current, the voltage that is caused by the electrode reaction impedance reduces change greatly, and power efficiency is variation sometimes.When 20Ah was above, though the electrode reaction impedance diminishes, power efficiency improved; But the Temperature Distribution that is caused by the inside battery heating when pulse discharges and recharges is big; The poor durability of repeated charge in addition, is being overcharged or the violent adstante febre when unusual such as internal short-circuit; Its exothermal efficiency is variation also, presses the probability that rises and make phenomenon (valve work), the cell contents of vent valve work be ejected into the phenomenon (breaking) of outside tempestuously in the generation and raises sometimes.
[[thickness of positive plate]]
The thickness of positive plate is not special to be limited; But viewpoint from high power capacity and high output; The metal foil thickness plied timber layer afterwards that deducts core is preferably more than the 10 μ m at the lower limit of the thickness on the one side of collector body; 20 μ m more preferably, its upper limit is preferably below the 200 μ m, more preferably below the 100 μ m.
< anodal [1] >
Below, the positive pole [1] " positive pole that comprises the positive active material that contains manganese " that uses in the lithium secondary battery of the present invention is described.
[positive active material of anodal [1]]
Below, the positive active material that uses in anodal [1] is described.
[[composition]]
As positive active material, be to contain and to emit the material of the transition metal of lithium ion with the electrochemical means occlusion, as at least a portion of transition metal, in the present invention, use the positive active material that contains manganese.Preferably further contain lithium, more preferably contain the composite oxides of lithium and manganese.
The above-mentioned positive active material that contains manganese does not limit especially, but preferably has the positive active material of the composition of following composition formula (5) expression.
Li xMn (1-y)M 1 yO 2Composition formula (5)
[in the composition formula (5), M 1Expression is selected from least a element among Ni, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤1.2, and y representes to satisfy the number of 0.05≤y≤0.8].
In composition formula (5), M 1Preferred especially Ni, Co, Fe, in addition, the preferred especially 0.2≤x of x≤1.15, the preferred especially 0.1≤y of y≤0.7.As the object lesson of the material of composition, for example can enumerate LiMn with composition formula (5) expression 0.5Ni 0.5O 2
In addition, preferred especially M 1Be Ni, and have the positive active material of the composition of following composition formula (6) expression.
Li xMn (1-y-z)Ni 1 yM 2 zO 2Composition formula (6)
[in the composition formula (6), M 2Expression is selected from least a element among Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤1.2, and y representes to satisfy the number of 0.05≤y≤0.8, and z representes to satisfy the number of 0.01≤z≤0.5].
In composition formula (6), M 2Preferred especially Co, Al, Fe, Mg, the preferred especially 0.2≤x of x≤1.15, the preferred especially 0.1≤y of y≤0.7, the preferred especially 0.1≤z of z≤0.7, the preferred especially 0.2≤y+z of y+z≤0.7.As the object lesson of the material of composition, for example can enumerate LiMn with composition formula (6) expression 0.33Ni 0.33Co 0.33O 2Deng.
As the positive active material that contains manganese, preferably has the positive active material of the composition of following composition formula (7) expression.
Li xMn (2-y)M 3 yO 4Composition formula (7)
[in the composition formula (7), M 3Expression is selected from least a element among Ni, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤1.2, and y representes to satisfy the number of 0.05≤y≤0.8].
In composition formula (7), M 3Preferred especially Ni, Co, Al, Mg, in addition, the preferred especially 0.05≤x of x≤1.15, the preferred especially 0.1≤y of y≤0.7.As the object lesson of the material of composition, for example can enumerate LiMn with composition formula (7) expression 1.8Al 0.2O 4, LiMn 1.5Ni 0.5O 4Deng.
[[surface coats]]
In addition, the preferred use in the surface attachment of this positive active material by forming the positive active material of different materials with the above-mentioned positive active material that contains manganese.The kind of surface attachment material, adherence method, adhesion amount etc. are same as described above.
[[shape]]
The shape of particle of this positive active material is same as described above.
[[tap density]]
The tap density of this positive active material is same as described above.
[[median particle diameter d 50]]
The median particle diameter d of the particle of this positive active material 50(primary particle cohesion and when forming offspring, be the offspring diameter) is same as described above.
[[average primary particle diameter]]
Primary particle cohesion and when forming offspring, the average primary particle diameter of positive active material is same as described above.
[[BET specific area]]
The BET specific area of positive active material is same as described above.
[[autofrettage]]
As the autofrettage of this positive active material, use usual way as the autofrettage of inorganic compound.Particularly when making spherical or oval spherical active material; Can consider the whole bag of tricks; Method for example can be listed below: the raw material dissolving of manganese raw material such as manganese nitrate, manganese sulfate and other elements of using as required or grinding dispersion in the water equal solvent, are regulated pH while stirring, make and obtain spherical precursor; After being dried as required, add LiOH, Li 2CO 3, LiNO 3In the Li source, sintering and obtain the method for active material at high temperature; With the raw material dissolving of manganese raw material such as manganese nitrate, manganese sulfate, manganese oxide, manganese oxyhydroxide and other elements of using as required or grinding dispersion in the water equal solvent; Be dried moulding through spray dryer etc. again; Process spherical or oval spherical precursor, add LiOH, Li then therein 2CO 3, LiNO 3In the Li source, sintering and obtain the method for active material at high temperature; And with manganese raw materials such as manganese nitrate, manganese sulfate, manganese oxide, manganese oxyhydroxide and LiOH, Li 2CO 3, LiNO 3Deng the raw material dissolving of Li source and other elements of using as required or grinding dispersion in the water equal solvent; Be dried moulding through spray dryer etc. again; Process spherical or oval spherical precursor, at high temperature its sintering is obtained the method for active material then.
Positive active material among the present invention can use this positive active material that contains manganese separately, also can this contain positive active material of manganese and the positive active materials that the positive active material composition is different or powder property is different that one or more and this contain manganese with the use of combination and ratio combination arbitrarily.As the preferred combination of this moment, can enumerate the positive active material and the LiNiO that contain manganese 2Or its part Ni is substituted by other transition metal and the combination of the material that obtains; The positive active material and the LiCoO that perhaps contain manganese 2Or its Part of Co is substituted by other transition metal and the combination of the material that obtains.In addition, as especially preferably combination, also can enumerate the positive active material and the LiNiO of composition formula (5)～(7) expression 2Or its part Ni is substituted by other transition metal and the combination of the material that obtains; The perhaps positive active material and the LiCoO of composition formula (5)～(7) expressions 2Or its Part of Co is substituted by other transition metal and the combination of the material that obtains.The positive active material of the positive active material that contains manganese, particularly composition formula (5)～(7) expression is preferably more than the 30 quality % of whole positive active materials, more preferably more than the 50 quality %.Composition formula (5)～(7) then can not reduce anodal cost sometimes if the usage ratio of the positive active material of expression tails off.
[structure of the positive pole of anodal [1]]
Below, the structure of positive pole of using in anodal [1] is described.
The thickness of the jointing material that uses during the manufacturing of the compacting of electrode structure in anodal [1] and manufacture method, positive electrode active material layer, electric conducting material, positive electrode active material layer, the liquid medium that is used to form slurry, collector body, electrode area, discharge capacity, positive plate etc. are same as described above.
< anodal [2] >
Below, the positive pole [2] " positive pole that contains the positive active material with specific composition of composition formula (4) expression " that uses in the lithium secondary battery of the present invention is described.
[positive active materials of anodal [2]]
Below, the positive active material that uses in anodal [2] is described.
[[composition]]
As positive active material, use composition with following composition formula (4) expression, contain and can and emit the material (below, abbreviate " this positive active material " as) of the transition metal of lithium ion with the electrochemical means occlusion.
Li xNi (1-y-z)Co yM zO 2Composition formula (4)
[in the composition formula (4), M representes to be selected from least a element among Mn, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤1.2, and y representes to satisfy the number of 0.05≤y≤0.5, and z representes to satisfy the number of 0.01≤z≤0.5].
In composition formula (4), M is preferably Mn, Al or Mg, in addition, and the preferred 0.2≤x of x≤1.15.In addition, the preferred 0.08≤y of y≤0.4, preferred especially 0.1≤y≤0.3.In addition, the preferred 0.02≤z of z≤0.4, preferred especially 0.03≤z≤0.3.
[[surface coats]]
In addition, the preferred use in the surface attachment of this positive active material by forming the positive active material of different materials with this positive active material.The kind of surface attachment material, adherence method, adhesion amount etc. are same as described above.
[[shape]]
The shape of particle of this positive active material is same as described above.
[[tap density]]
The tap density of this positive active material is same as described above.
[[median particle diameter d 50]]
The median particle diameter d of the particle of this positive active material 50(primary particle cohesion and when forming offspring, be the offspring diameter) is same as described above.
[[average primary particle diameter]]
Primary particle cohesion and when forming offspring, the average primary particle diameter of positive active material is same as described above.
[[BET specific area]]
The BET specific area of positive active material is same as described above.
[[autofrettage]]
As the autofrettage of this positive active material, can use usual way as the autofrettage of inorganic compound.Particularly when making spherical or oval spherical active material; Can consider the whole bag of tricks; Method for example can be listed below: the raw material dissolving of the M in cobalt raw material material such as nickel raw material such as nickel nitrate, nickelous sulfate and cobalt nitrate, cobaltous sulfate and the composition formula (4) or grinding dispersion in the water equal solvent, are regulated pH while stirring, make and obtain spherical precursor; After being dried as required, add LiOH, Li 2CO 3, LiNO 3In the Li source, sintering and obtain the method for active material at high temperature; With the raw material dissolving of the M in cobalt raw material material such as nickel raw material such as nickel nitrate, nickelous sulfate, nickel oxide, nickel hydroxide, nickel oxyhydroxide and cobalt nitrate, cobaltous sulfate, cobalt oxide, cobalt hydroxide, alkali formula cobalt hydroxide and the composition formula (4) or grinding dispersion in the water equal solvent; Be dried moulding through spray dryer etc. again; Process spherical or oval spherical precursor, add LiOH, Li then therein 2CO 3, LiNO 3In the Li source, sintering and obtain the method for active material at high temperature; And with the raw material of the M in cobalt raw material materials such as nickel raw materials such as nickel nitrate, nickelous sulfate, nickel oxide, nickel hydroxide, nickel oxyhydroxide and cobalt nitrate, cobaltous sulfate, cobalt oxide, cobalt hydroxide, alkali formula cobalt hydroxide and the composition formula (4) and LiOH, Li 2CO 3, LiNO 3In the water equal solvent, be dried moulding through spray dryer etc. Deng Li source dissolving or grinding dispersion again, process spherical or oval spherical precursor, at high temperature its sintering is obtained the method for active material then.
In order to make the positive pole among the present invention; Can use this positive active material (positive active material of composition formula (4) expression and/or the positive active material of representing by the composition formula (4) that above-mentioned surface attachment material coats) separately, also can use this positive active material to form different materials with this positive active material with combination and ratio combination arbitrarily with more than one.As the preferred combination of this moment, can enumerate this positive active material and LiMn 2O 4Or its part Mn is substituted by other transition metal and the combination of the material that obtains; Perhaps this positive active material and LiCoO 2Or its Part of Co is substituted by other transition metal and the combination of the material that obtains.
Here, preferably this positive active material is more than the 30 quality % of whole positive active materials, more preferably more than the 50 quality %.If the usage ratio of this positive active material tails off, then battery capacity diminishes sometimes.In addition, " this positive active material " and " positive active material beyond this positive active material " is generically and collectively referred to as " positive active material ".
[structure of the positive pole of anodal [2]]
Below, the structure of the positive pole of use in anodal [2] is narrated.
The thickness of the jointing material that uses during the manufacturing of the compacting of electrode structure in anodal [2] and manufacture method, positive electrode active material layer, electric conducting material, positive electrode active material layer, the liquid medium that is used to form slurry, collector body, electrode area, discharge capacity, positive plate etc. are same as described above.
< anodal [3] >
Below, the positive pole [3] that uses in the lithium secondary battery of the present invention " is comprised the positive pole that is selected from any positive active material in following (a)～(d) " describe.
(a) the BET specific area is 0.4m 2/ g～2m 2The positive active material of/g
(b) average primary particle diameter is the positive active material of 0.1 μ m～2 μ m
(c) median particle diameter d 50It is the positive active material of 1 μ m～20 μ m
(d) tap density is 1.3g/cm 3～2.7g/cm 3Positive active material.
[positive active materials of anodal [3]]
Below, the positive active material that uses in anodal [3] is narrated.
[[composition]]
As positive active material, so long as can get final product not special restriction with electrochemical means occlusion and the material of emitting lithium ion.The material that preferably contains lithium and at least a transition metal for example can be enumerated lithium-compound transition metal oxide, contain the transition metal phosphate cpd of lithium.Particularly, can use the material that has with above-mentioned same composition.
[[surface coats]]
The surface attachment of preferred this positive active material is by forming the positive active material of different materials with the positive active material of core.The kind of surface attachment material, adherence method, adhesion amount etc. are same as described above.
[[shape]]
The shape of particle of this positive active material is same as described above.
[[BET specific area]]
The BET specific area of this positive active material is preferably 0.4m 2More than/the g, 0.5m more preferably 2More than/the g, further be preferably 0.6m 2More than/the g, its upper limit is preferably 2m 2Below/the g, 1.8m more preferably 2Below/the g, further be preferably 1.5m 2Below/the g.If the BET specific area is littler than this scope, then battery performance reduces easily, and if the BET specific area is bigger than this scope, then tap density is difficult to improve, and is easy to generate problem sometimes on the coating when forming positive active material.
The BET specific area is defined as following value: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation 150 ℃ to test portion carry out 30 minutes predrying; Using then and correctly being adjusted into nitrogen is 0.3 nitrogen helium gas mixture body with respect to atmospheric relative pressure value, the value of measuring through 1 method of nitrogen absorption BET that adopts the gas flow method to carry out.
[[average primary particle diameter]]
Primary particle cohesion and when forming offspring, the average primary particle diameter of this positive active material is preferably more than the 0.1 μ m, more preferably more than the 0.2 μ m; Further be preferably more than the 0.3 μ m; Most preferably be more than the 0.4 μ m, its upper limit is preferably below the 2 μ m, more preferably below the 1.6 μ m; Further be preferably below the 1.3 μ m, most preferably be below the 1 μ m.If average primary particle diameter surpasses the above-mentioned upper limit, then be difficult to form spherical offspring, the powder fillibility is brought harmful effect, perhaps specific area significantly reduces, and therefore, the possibility that battery performances such as output characteristic reduce uprises sometimes.On the contrary, if average primary particle diameter is lower than above-mentioned lower limit,, therefore produce the problems such as invertibity difference that discharge and recharge sometimes then usually because crystallization is incomplete.
Primary particle size can be measured through the observation of using scanning electron microscopy (SEM).Particularly, obtain: in the photo of 10000 times of multiplying powers, 50 primary particles are arbitrarily obtained the greatest length of the section that the right sides boundary line by primary particle on the straight line of horizontal direction produces, and got its mean value through following method.
[[median particle diameter d 50]]
The median particle diameter d of the particle of this positive active material 50(primary particle cohesion and when forming offspring, be the offspring diameter) is preferably more than the 1 μ m, more preferably more than the 1.2 μ m; Further be preferably more than the 1.5 μ m; Most preferably be more than the 2 μ m, its upper limit is preferably below the 20 μ m, more preferably below the 18 μ m; Further be preferably below the 16 μ m, most preferably be below the 15 μ m.If median particle diameter d 50Be lower than above-mentioned lower limit; Then can not obtain the product of high-tap density sometimes; And if above the upper limit, then because the diffusion of the lithium in the particle needs the time, therefore producing battery performance sometimes reduces; Perhaps processing the positive pole of battery, when just slurryization is coated with into film like again in solvent with conductive agent or adhesive etc. with active material, producing problems such as striped.Positive active material of the present invention is to have mixed to have different median particle diameter d more than 2 kinds 50Positive active material and the positive active material that obtains the time, can further improve the fillibility of making when anodal, be preferred.
In addition, the median particle diameter d among the present invention 50Can utilize known laser diffraction/diffuse transmission type particle size distribution device to measure.The LA-920 that uses the HORIBA manufactured is as the particle size distribution timing, and the decentralized medium that uses when measuring uses 0.1 quality % sodium hexametaphosphate solution, carry out 5 minutes ultrasonic dispersing after, set and measure refractive index 1.24 and measure.
[[tap density]]
The tap density of this positive active material is preferably 1.3g/cm 3More than, 1.5g/cm more preferably 3More than, further be preferably 1.6g/cm 3More than, most preferably be 1.7g/cm 3More than.If the tap density of positive active material is lower than above-mentioned lower limit; Then when forming positive electrode active material layer; The decentralized medium amount that needs increases; The necessary amount of electric conducting material or adhesive increases simultaneously, and the filling rate of positive active material in positive electrode active material layer is restricted, and battery capacity is restricted sometimes.Through using the high composite oxide power of tap density, can form highdensity positive electrode active material layer.In general; Tap density is preferred more greatly more, does not have the special upper limit, if but tap density is too big; In the positive electrode active material layer with electrolyte the factor that the diffusion of the lithium ion of medium becomes decision speed then; Part throttle characteristics reduces sometimes easily, and therefore, the upper limit of tap density is preferably 2.7g/cm 3Below, 2.5g/cm more preferably 3Below.
In the present invention, tap density is as giving a definition: make test portion fall 20cm through the sieve of aperture 300 μ m 3The jolt ramming container in, be full of after the vessel volume, use powder density determination device (for example, the Tap densor that society of seishin enterprise makes), carry out the vibration of 1000 length of stroke 10mm, with the volume density of this moment as tap density.
From long-life, high output facet, the positive active material in the lithium secondary battery of the present invention especially preferably satisfies above-mentioned BET specific area, average primary particle diameter, median particle diameter d simultaneously 50With the rerum natura more than 2 kinds in the tap density.
[[autofrettage]]
The autofrettage of this positive active material is same as described above.
Positive active material in the lithium secondary battery of the present invention can use a kind of separately, also can form positive active materials different or that powder property is different more than 2 kinds with combination arbitrarily and ratio combination and use.In addition, from improve the life-span this put, positive pole of the present invention preferably contains positive active material (this positive active material) with above-mentioned any one rerum natura and forms the positive pole of different positive active materials with this positive active material.
[structure of the positive pole of anodal [3]]
Below, the structure of the positive pole of use in anodal [3] is narrated.
The thickness of the jointing material that uses during the manufacturing of the compacting of electrode structure in anodal [3] and manufacture method, positive electrode active material layer, electric conducting material, positive electrode active material layer, the liquid medium that is used to form slurry, collector body, electrode area, discharge capacity, positive plate etc. are same as described above.
< anodal [4] >
Below, the positive pole [4] that uses in the lithium secondary battery of the present invention " is satisfied the positive pole of the arbitrary condition in following (e)～(f) that is selected from " describe.
(e) on collector body, form the positive pole that contains the positive electrode active material layer of positive active material, electric conducting material and adhesive and make, wherein, the content of the electric conducting material in the positive electrode active material layer is the scope (mode 1) of 6 quality %～20 quality %
(f) on collector body, form the positive pole that contains the positive electrode active material layer of positive active material and adhesive and make, wherein, the density of positive electrode active material layer is 1.7g/cm 3～3.5g/cm 3Scope (mode 2)
(g) on collector body, form the positive pole that contains the positive electrode active material layer of positive active material and adhesive and make; Wherein, the value of the ratio of the thickness of positive electrode active material layer and collector body (injecting the thickness of a nonaqueous electrolytic solution side active material layer before)/(thickness of collector body) is 1.6～20 (modes 3).
[positive active materials of anodal [4]]
Below, the positive active material that uses in anodal [4] is narrated.
As positive active material, so long as can get final product not special restriction with electrochemical means occlusion and the material of emitting lithium ion.The material that preferably contains lithium and at least a transition metal for example can be enumerated lithium-compound transition metal oxide, contain the transition metal phosphate cpd of lithium.Particularly, can use the material that has with above-mentioned same composition.
The surface coating of this positive active material, shape, tap density, median particle diameter d 50, average primary particle diameter, BET specific area, autofrettage etc. be same as described above.
[structure of the positive pole of anodal [4]]
Below, the structure of the positive pole of use in anodal [4] is narrated.
[[electrode structure and facture]]
Positive pole in the lithium secondary battery of the present invention [4] forms the positive electrode active material layer that contains positive active material and adhesive and makes on collector body.Use the manufacturing of the positive pole of positive active material to carry out according to usual way.Promptly; Carry out dry mixed to the thickener of major general's positive active material, adhesive, the electric conducting material (in mode 1 for to contain composition) that uses as required and use as required etc. and process sheet, again this flaky material pressure is bonded on the positive electrode collector, perhaps with these material dissolves or be dispersed in the liquid medium; Process slurry; Be coated on this slurry on the positive electrode collector again and carry out drying, can on collector body, form positive electrode active material layer thus, thereby obtain positive pole.
The content of the positive active material in the positive electrode active material layer is preferably more than the 80 quality %, more preferably more than the 82 quality %, is preferably especially more than the 84 quality %.Its upper limit is preferably below the 95 quality %, more preferably below the 93 quality %.If the content of the positive active material in the positive electrode active material layer is low, then electric capacity becomes insufficient sometimes.On the contrary, if the content of positive active material is too high, then anodal intensity is insufficient sometimes.
[[electric conducting material]]
As electric conducting material, can use known electric conducting material arbitrarily.As concrete example, can enumerate electric conducting material same as described above.
The content of the electric conducting material that uses in the positive pole of lithium secondary battery of the present invention in positive electrode active material layer is following: in mode 1, be necessary for more than the 6 quality %; Be preferably more than the 7 quality %; More preferably more than the 8 quality %, further be preferably more than the 9 quality %; In addition, not special qualification the in mode 2 and mode 3, but be preferably more than the 6 quality %, more preferably more than the 7 quality %, further be preferably more than the 8 quality %.If the content of the electric conducting material in the positive electrode active material layer very little, conductivity is insufficient, can not get high output sometimes.
In addition, the upper limit of the content of the electric conducting material in the positive electrode active material layer is following: in mode 1, be necessary for below the 20 quality %, be preferably below the 18 quality %, be preferably especially below the 15 quality %; In addition, not special qualification the in mode 2 and mode 3, but be preferably below the 20 quality %, more preferably below the 18 quality %, further be preferably below the 15 quality %.If its content is too many, then battery capacity reduces, and can not get high output sometimes.
[[adhesive]]
As the adhesive that in the manufacturing of positive electrode active material layer, uses; Not special the qualification is when using rubbing method, so long as solubilized or the material that is dispersed in the liquid medium that uses when electrode is made get final product; As object lesson, can enumerate material same as described above.
The ratio of adhesive in positive electrode active material layer is generally more than the 0.1 quality %, is preferably more than the 1 quality %, more preferably more than the 3 quality %; Its upper limit is generally below the 80 quality %; Be preferably below the 60 quality %, more preferably below the 40 quality %, further be preferably below the 10 quality %.If the ratio of adhesive is too low, then can not fully keep positive active material sometimes, anodal mechanical strength is not enough, and battery performances such as cycle characteristics worsen.On the other hand, if the ratio of adhesive is too high, then cause battery capacity or conductivity to reduce sometimes.
[[being used to form the liquid medium of slurry]]
As the liquid medium that is used to form slurry; So long as can dissolve or disperse positive active material, conductive agent, adhesive and the solvent of the thickener that uses as required; Its kind is just not special to be limited, and can use in water solvent and the organic solvent any.As object lesson, can enumerate and above-mentioned same material.The kind of tackify material and addition are also same as described above.
[[compacting]]
In order to improve the packed density of positive active material, preferably utilize hand press, roll squeezer etc. to carry out compacting through coating, the dry positive electrode active material layer that obtains.The lower limit of the density of positive electrode active material layer is necessary for 1.7g/cm in mode 2 3More than, be preferably 2.0g/cm 3More than, be preferably 2.2g/cm especially 3More than; In addition, not special qualification the in mode 1 and mode 3, but be preferably 1.7g/cm 3More than, 2.0g/cm more preferably 3More than, further be preferably 2.2g/cm 3More than.If density is lower than this scope, then the conductivity between active material reduces, and battery impedance increases, and can not obtain high output sometimes.
The upper limit of the density of positive electrode active material layer is necessary for 3.5g/cm in mode 2 3Below, be preferably 3.0g/cm 3Below, be preferably 2.8g/cm especially 3Below; In addition, not special qualification the in mode 1 and mode 3, but be preferably 3.5g/cm 3Below, 3.0g/cm more preferably 3Below, further be preferably 2.8g/cm 3Below.If density is higher than this scope, then near the permeability of nonaqueous electrolytic solution collector body/reactive species interface reduces, and particularly the charge-discharge characteristic under high current density reduces, and can not obtain high output sometimes.
[[collector body]]
As the material of positive electrode collector, not special restriction, same as described above.In addition, the thickness of the shape of collector body and film is also same as described above.
For the ratio of the thickness of positive electrode active material layer and collector body, the value of (injecting the active material layer thickness of the side before the nonaqueous electrolytic solution)/(thickness of collector body) is necessary for below 20 in mode 3, is preferably below 15, is preferably especially below 10; In addition, not special qualification the in mode 1 and mode 2, but be preferably below 20, more preferably below 15, be preferably below 10 especially.If surpass this scope, then when high current density discharged and recharged, collector body can produce heating because of Joule heat sometimes, and positive pole sustains damage.
Lower limit for the value of (injecting the active material layer thickness of the side before the nonaqueous electrolytic solution)/(thickness of collector body) is necessary for more than 1.6 in mode 1, is preferably more than 1.8, is preferably especially more than 2; In addition, not special qualification the in mode 1 and mode 2, but be preferably more than 1.6, more preferably more than 1.8, further be preferably more than 2.If be lower than this scope, then owing to the volume ratio of collector body with respect to positive active material increases, the capacity of battery reduces, and can not obtain high output sometimes.
Above-mentioned " content of electric conducting material in positive electrode active material layer ", " density of positive electrode active material layer ", " ratio of the thickness of positive electrode active material layer and collector body; promptly (inject the active material layer thickness of the side before the nonaqueous electrolytic solution)/value of (thickness of collector body) " are if combination preferred range separately then can form the lithium secondary battery of preferred high output.
[[electrode area]]
When using nonaqueous electrolytic solution of the present invention, from height output and the viewpoint of the stability when improving high temperature, the area of preferred positive electrode active material layer is bigger than the external surface area of battery case, this with above-mentioned be identical.
[[discharge capacity]]
When using secondary cell of the present invention to use nonaqueous electrolytic solution; Be contained in electric capacity (electric capacity when battery is discharged to discharge condition by fully charged state) that the battery key element in the battery case of 1 secondary cell had if be more than 3 ampere-hours (Ah); Then the raising effect of output characteristic becomes big, so preferred.
Therefore, design of positive plate etc. etc. is also same as described above.
[[thickness of positive plate]]
The thickness of positive plate is not special to be limited, same as described above.
< anodal [5] >
Below, the positive pole [5] that uses in the lithium secondary battery of the present invention is described.
[positive active materials of anodal [5]]
Below, the positive active material that uses in anodal [5] is described.
[[composition]]
As positive active material, so long as can get final product not special restriction with electrochemical means occlusion and the material of emitting lithium ion.The material that preferably contains lithium and at least a transition metal for example can be enumerated lithium-compound transition metal oxide, contain the transition metal phosphate cpd of lithium.
As the transition metal of lithium-compound transition metal oxide, preferred V, Ti, Cr, Mn, Fe, Co, Ni, Cu etc. as object lesson, can enumerate LiCoO 2Deng lithium-cobalt composite oxide; LiNiO 2Deng lithium-ni compound oxide; LiMnO 2, LiMn 2O 4, Li 2MnO 3Deng lithium-manganese composite oxide; Substitute the part of the transition metal atoms that forms these lithiums-compound transition metal oxide main body and the material that obtains etc. with other metals such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si.
Above-mentioned lithium-cobalt composite oxide is not special to be limited, but preferably has the material of the composition of following composition formula (8) expression.
Li xCo (1-y)M 1 yO 2Composition formula (8)
[in the composition formula (8), M 1Expression is selected from least a element among Ni, Mn, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤1.2, and y representes to satisfy the number of 0.05≤y≤0.8].
In composition formula (8), M 1Preferred especially Ni, Mn, Al, Fe, in addition, the preferred especially 0.2≤x of x≤1.15, the preferred especially 0.1≤y of y≤0.5.
Above-mentioned lithium-ni compound oxide is not special to be limited, but preferably has the material of the composition of following composition formula (9) expression.
Li xNi (1-y)M 2 yO 2Composition formula (9)
[in the composition formula (9), M 2Expression is selected from least a element among Co, Mn, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤1.2, and y representes to satisfy the number of 0.05≤y≤0.8].
In composition formula (9), M 2Preferred especially Co, Mn, Al, Fe, in addition, the preferred especially 0.2≤x of x≤1.15, the preferred especially 0.1≤y of y≤0.5.
Above-mentioned lithium-manganese composite oxide is not special to be limited, but preferably has the material of the composition of following composition formula (10) expression.
Li xMn (1-y)M 3 yO 2Composition formula (10)
[in the composition formula (10), M 3Expression is selected from least a element among Ni, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤1.2, and y representes to satisfy the number of 0.05≤y≤0.8].
In composition formula (10), M 3Preferred especially Ni, Co, Fe, in addition, the preferred especially 0.2≤x of x≤1.15, the preferred especially 0.1≤y of y≤0.7.
As above-mentioned lithium-manganese composite oxide, preferably has the material of the composition of following composition formula (11) expression.
Li xMn (2-y)M 4 yO 4Composition formula (11)
[in the composition formula (11), M 4Expression is selected from least a element among Ni, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤1.2, and y representes to satisfy the number of 0.05≤y≤0.8].
In composition formula (11), M 4Preferred especially Ni, Co, Al, Mg, in addition, the preferred especially 0.05≤x of x≤1.15, the preferred especially 0.1≤y of y≤0.7.
As above-mentioned lithium-manganese composite oxide, preferably has the material of the composition of following composition formula (12) expression.
Li xMn (1-y)M 5 yO 3Composition formula (12)
[in the composition formula (12), M 5Expression is selected from least a element among Ni, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤2.4, and y representes to satisfy the number of 0.05≤y≤0.8].
In composition formula (12), M 5Preferred especially Ni, Co, Al, Mg, in addition, the preferred especially 0.1≤x of x≤2.3, the preferred especially 0.1≤y of y≤0.5.
As the transition metal of the transition metal phosphate cpd that contains lithium, preferred V, Ti, Cr, Mn, Fe, Co, Ni, Cu etc. as object lesson, for example can enumerate LiFePO 4, Li 3Fe 2(PO 4) 3, LiFeP 2O 7Deng the ferric phosphate class; LiCoPO 4Deng the cobalt phosphate class; Substitute a part and the material that obtains etc. of the transition metal atoms of the main body that forms these transition metal phosphate cpds that contain lithium with other metals such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si.
Above-mentioned ferric phosphate class is not special to be limited, but preferably has the material of the composition of following composition formula (13) expression.
Li xFe (1-y)M 6 yPO 4Composition formula (13)
[in the composition formula (13), M 6Expression is selected from least a element among Ni, Co, Mn, Al, Ti, Mg, Cr, Ga, Cu, Zn and the Nb, and x representes to satisfy the number of 0＜x≤1.2, and y representes to satisfy the number of 0.05≤y≤0.8].
In composition formula (13), M 6Preferred especially Ni, Co, Mn, Al, in addition, the preferred especially 0.2≤x of x≤1.15, the preferred especially 0.1≤y of y≤0.5.
Positive active material among the present invention preferably makes up the different material more than 2 kinds of composition that uses in the above-mentioned positive active material with combination arbitrarily with ratio.Because the performance that various positive active materials are good at separately is different, so positive active material preferably makes up the performance of needs according to the purposes of target battery.In general; Think and to make the performance addition average through combination; But for the life-span; All of a sudden can further obtain the effect of long positive active material of life-span sometimes, through the better positive active material of combined lifetime with the life-span poor but other well behaved positive active materials, can realize high output of the present invention, capacity, long-life lithium secondary battery greatly.
As the example of preferred combination, combination can be listed below:
The positive active material of the positive active material of composition formula (8) expression and composition formula (10) expression,
The positive active material of the positive active material of composition formula (8) expression and composition formula (11) expression,
The positive active material of the positive active material of composition formula (8) expression and composition formula (12) expression,
The positive active material of the positive active material of composition formula (8) expression and composition formula (13) expression,
The positive active material of the positive active material of composition formula (9) expression and composition formula (10) expression,
The positive active material of the positive active material of composition formula (9) expression and composition formula (11) expression,
The positive active material of the positive active material of composition formula (9) expression and composition formula (12) expression,
The positive active material of the positive active material of composition formula (9) expression and composition formula (13) expression,
The positive active material of the positive active material of composition formula (10) expression and composition formula (11) expression,
The positive active material of the positive active material of composition formula (10) expression and composition formula (12) expression,
The positive active material of the positive active material of composition formula (10) expression and composition formula (13) expression.
Particularly preferably be,
The positive active material of the positive active material of composition formula (9) expression and composition formula (11) expression,
The positive active material of the positive active material of composition formula (10) expression and composition formula (11) expression.
Portfolio ratio is not special to be limited, but be preferably 10: 90～90: 10, more preferably 20: 80～80: 20.
In the positive pole that uses in the lithium secondary battery of the present invention, contain and form the different positive active materials more than 2 kinds, BET specific area, average primary particle diameter, the median particle diameter d of preferred at least a positive active material wherein 50And/or tap density (below, note by abridging be " following rerum natura ") is in following specific scope.Form in the different positive active materials more than 2 kinds, also comprise the not positive active material in following ranges of certain rerum natura, but certain rerum natura of all materials of preferred positive active material more than 2 kinds is all in following ranges." following any rerum natura all positive active materials in following particular range " are with respect to containing of " all positive active materials that contain in the positive pole " of proportional its rerum natura that depends on; Not special the qualification; But be preferably more than the 30 quality %; More preferably more than the 50 quality %, especially preferably they are whole.In the preferred anodal positive active material more than 2 kinds that is contained each; The above rerum natura of in its following rerum natura any one is in the following specific scope; More preferably arbitrarily more than 2 kinds rerum natura be in the following specific scope; Preferred especially arbitrarily more than 3 kinds rerum natura be in the following specific scope, most preferably following all rerum naturas all are in the following specific scope.
[[BET specific area]]
The BET specific area of at least a positive active material in this positive active material is preferably 0.4m 2More than/the g, 0.5m more preferably 2More than/the g, further be preferably 0.6m 2More than/the g, be limited to 2m on it 2Below/the g, be preferably 1.8m 2Below/the g, 1.5m more preferably 2Below/the g.If the BET specific area is littler than this scope, then battery performance reduces easily, and if the BET specific area is bigger than this scope, then tap density is difficult to improve, and is easy to generate problem sometimes on the coating when forming positive active material.
The BET specific area is defined as following value: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation 150 ℃ to test portion carry out 30 minutes predrying; Using then and correctly being adjusted into nitrogen is 0.3 nitrogen helium gas mixture body with respect to atmospheric relative pressure value, the value of measuring through the nitrogen absorption BET1 point method that adopts the gas flow method to carry out.
[[average primary particle diameter]]
As the average primary particle diameter of at least a positive active material in this positive active material, be preferably more than the 0.1 μ m, more preferably more than the 0.2 μ m; Further be preferably more than the 0.3 μ m; Most preferably be more than the 0.4 μ m, its upper limit is preferably below the 2 μ m, more preferably below the 1.6 μ m; Further be preferably below the 1.3 μ m, most preferably be below the 1 μ m.If surpass the above-mentioned upper limit, then be difficult to form spherical offspring, the powder fillibility is brought harmful effect, perhaps specific area significantly reduces, and therefore, the possibility that battery performances such as output characteristic reduce uprises sometimes.On the contrary, if be lower than above-mentioned lower limit,, therefore produce the problems such as invertibity difference that discharge and recharge sometimes then usually because crystallization is incomplete.
In addition, primary particle size can be measured through the observation of using scanning electron microscopy (SEM).Particularly, obtain: in the photo of 10000 times of multiplying powers, 50 primary particles are arbitrarily obtained the greatest length of the section that the right sides boundary line by primary particle on the straight line of horizontal direction produces, and got its mean value through following method.Form the situation of offspring though there is the primary particle cohesion, in this case, also only primary particle is measured.
[[median particle diameter d 50]]
The median particle diameter d of the particle of at least a positive active material in this positive active material 50(primary particle cohesion and when forming offspring, be the offspring diameter) is preferably more than the 1 μ m, more preferably more than the 1.2 μ m; Further be preferably more than the 1.5 μ m; Most preferably be more than the 2 μ m, its upper limit is preferably below the 20 μ m, more preferably below the 18 μ m; Further be preferably below the 16 μ m, most preferably be below the 15 μ m.If be lower than above-mentioned lower limit; Then can not obtain the product of high-tap density sometimes; And if above the upper limit, then because the diffusion of the lithium in the particle needs the time, therefore producing battery performance sometimes reduces; Perhaps processing the positive pole of battery, when just slurryization is coated with into film like again in solvent with conductive agent or adhesive etc. with active material, producing problems such as striped.Here, has different median particle diameter d more than 2 kinds through mixing 50Positive active material, can further improve the fillibility of making when anodal.
Median particle diameter d among the present invention 50Can utilize known laser diffraction/diffuse transmission type particle size distribution device to measure.The LA-920 that uses the HORIBA manufactured is as the particle size distribution timing, and the decentralized medium that uses when measuring uses 0.1 quality % sodium hexametaphosphate solution, carry out 5 minutes ultrasonic dispersing after, set and measure refractive index 1.24 and measure.
[[[tap density]]]
The tap density of at least a positive active material in this positive active material is preferably 1.3g/cm 3More than, 1.5g/cm more preferably 3More than, further be preferably 1.6g/cm 3More than, most preferably be 1.7g/cm 3More than.If the tap density of positive active material is lower than above-mentioned lower limit; Then when forming positive electrode active material layer; The decentralized medium amount that needs increases; The necessary amount of electric conducting material or adhesive increases simultaneously, and the filling rate of positive active material in positive electrode active material layer is restricted, and battery capacity is restricted sometimes.Through using the high composite oxide power of tap density, can form highdensity positive electrode active material layer.In general; Tap density is preferred more greatly more, does not have the special upper limit, if but tap density is too big; In the positive electrode active material layer with the nonaqueous electrolytic solution factor that the diffusion of the lithium ion of medium becomes decision speed then; Part throttle characteristics reduces sometimes easily, and therefore, the upper limit of tap density is preferably 2.7g/cm 3Below, 2.5g/cm more preferably 3Below.
In the present invention, tap density is as giving a definition: make test portion fall 20cm through the sieve of aperture 300 μ m 3The jolt ramming container in, be full of after the vessel volume, use powder density determination device (for example, the Tap densor that society of seishin enterprise makes), carry out the vibration of 1000 length of stroke 10mm, with the volume density of this moment as tap density.
[[surface coats]]
At least a positive active material in this positive active material preferably uses its surface attachment by forming different material (below, note by abridging be " surface attachment material ") with the positive active material of positive active material that constitutes its positive active material main body or core.The kind of surface attachment material, adherence method, adhesion amount etc. are same as described above.
[[shape]]
The shape of particle of at least a positive active material in this positive active material can adopt the shape same as described above as in the past using.
[[autofrettage]]
As the autofrettage of positive active material, can use usual way with above-mentioned same autofrettage as inorganic compound.
[structure of the positive pole of anodal [5]]
Below, the structure of the positive pole of use in anodal [5] is narrated.
In the present invention, thickness of the jointing material that uses during the manufacturing of the compacting of electrode structure and manufacture method, positive electrode active material layer, electric conducting material, positive electrode active material layer, the liquid medium that is used to form slurry, collector body, electrode area, discharge capacity, positive plate etc. is same as described above.When making positive pole, positive active material can mix use more than 2 kinds in advance, also can when making positive pole, add simultaneously and mix.
< negative pole >
The negative pole that uses in the lithium secondary battery of the present invention; Contain the negative pole of active material layer of can occlusion and emitting the active material of lithium ion and get final product so long as on collector body, form; Not special restriction, but this negative pole is preferably selected from any one negative pole in following negative pole [1]～negative pole [10]:
Negative pole [1]: contain crystallinity is different more than 2 kinds carbonaceous material negative pole as negative electrode active material;
Negative pole [2]: contain the negative pole of amorphous carbonaceous as negative electrode active material; Said amorphous carbonaceous is more than the 0.337nm through the interplanar distance (d002) of (002) face that wide-angle x-ray diffraction is measured; Crystallite size (Lc) is below the 80nm, adopt that the argon laser Raman spectroscopy measures with 1360cm -1Peak intensity with respect to 1580cm -1The Raman R value of ratio definition of peak intensity be more than 0.2;
Negative pole [3]: contain the negative pole of metal oxide as negative electrode active material, said metal oxide contains can occlusion and emit the titanium of lithium ion;
Negative pole [4]: contain the negative pole of carbonaceous material as negative electrode active material, the circularity of said carbonaceous material is more than 0.85, and surface functional group amount O/C value is 0～0.01;
Negative pole [5]: contain the negative pole of different orientation carbon complex as negative electrode active material, said different orientation carbon complex contains the different carbonaceous material of orientation more than 2 kinds;
Negative pole [6]: contain the negative pole of graphite matter carbon particle as negative electrode active material; The circularity of said graphite matter carbon particle is more than 0.85; The interplanar distance (d002) of (002) face of measuring through wide-angle x-ray diffraction is lower than 0.337nm, adopt that the argon laser Raman spectroscopy measures with 1360cm -1Peak intensity with respect to 1580cm -1The Raman R value of ratio definition of peak intensity be 0.12～0.8;
Negative pole [7]: contain the negative pole of the following negative electrode active material that comprises multielement (C) as negative electrode active material; The said negative electrode active material (C) that comprises multielement contains at least a in the lithium occlusion metal (A) that is selected from Al, Pb, Zn, Sn, Bi, In, Mg, Ga, Cd, Ag, Si, B, Au, Pt, Pd and Sb and/or the lithium occlusion alloy (B), and contains C and/or N as element Z;
Negative pole [8]: contain the negative pole of the negative electrode active material more than 2 kinds of different in kind as negative electrode active material;
Negative pole [9]: containing tap density is 0.1g/cm 3More than, and the micropore volume of the particle that is equivalent to diameter 0.01 μ m～1 mu m range of employing mercury porosimeter mensuration is the negative pole of the above negative electrode active material of 0.01mL/g;
Negative pole [10]: be charged to 60% o'clock of nominal capacity of this negative pole, the reaction resistance that is produced by the opposed battery of negative pole is the negative pole below 500 Ω.
Below, at first normally used negative pole in the lithium secondary battery of the present invention is described.
[negative electrode active material]
Below, normally used negative electrode active material is narrated in the anticathode.
[[composition]]
As negative electrode active material; As long as can and emit lithium ion with the electrochemical means occlusion; Have no particular limits, can enumerate lithium alloy, Sn or Si etc. such as metal oxides such as carbonaceous material, tin oxide or silica, composite oxide of metal, lithium simple substance or lithium-aluminium alloy and can form metal of alloy etc. with lithium.They can use separately, also can use more than 2 kinds with combination and ratio combination arbitrarily.Wherein, from security point, preferably use carbonaceous material or lithium composite xoide.
As composite oxide of metal,, have no particular limits, but on high current density charge-discharge characteristic this point, preferably contain titanium and/or lithium as constituent as long as can occlusion and emit lithium.
As carbonaceous material, from the balance of initial stage irreversible capacity, high current density charge-discharge characteristic, preferred following carbonaceous material:
(1) native graphite;
(2) artificial carbon's metallic substance and Delanium material; [for example, native graphite, coal class coke, petroleum-type coke, coal class pitch, petroleum-type pitch are perhaps handled these bitumen blowings and material, needle coke, pitch coke that obtains and the material with carbon element that their part graphitizations are obtained with carbonaceous material; But the organic substance of organic thermal decomposition product carbonizations such as furnace black, acetylene black, pitch-based carbon fiber (for example, straight run class heavy oil such as coal such as coal tar asphalt from the maltha to the pitch or dry distillation liquid carburetion class heavy oil, atmospheric resids, decompression residual oil; The ethylene bottom oil of by-product etc. decomposes a type black petroleum products during thermal decomposition such as crude oil, naphtha; And aromatic hydrocarbon such as acenaphthylene, decacyclene, anthracene, phenanthrene; Azo-cycle compound such as azophenlyene or acridine; Sulphur cycle compounds such as thiophene, di-thiophene; Polyphenyl such as biphenyl, terphenyl; Polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral resin, they do not dissolve organic polymers such as handled thing, nitrogenous polyacrylonitrile, polypyrrole; Organic polymers such as the polythiophene of sulfur-bearing, polystyrene; With cellulose, lignin, mannosan, polygalacturonic acid, shitosan, sucrose is the natural polymers such as polysaccharide of representative; Thermoplastic resin such as polyphenylene sulfide, polyphenylene oxide; Thermosetting resins such as furfuryl alcohol resin, phenolic resins, imide resin) and their carbide; Perhaps but the organic substance of carbonization is dissolved in the small molecular organic solvents such as benzene,toluene,xylene, quinoline, n-hexane and solution that forms and their carbide] heat treatment more than in 400～3200 ℃ of scopes, carrying out once and the material with carbon element that forms;
(3) negative electrode active material layer is by having more than at least 2 kinds that different crystalline carbonaceous constitute and/or its different crystalline carbonaceous have the material with carbon element at contacted interface;
(4) negative electrode active material layer is made up of the carbonaceous that has different orientation property more than at least 2 kinds and/or the carbonaceous of its different orientation property has the material with carbon element at contacted interface.
[structure of negative pole, rerum natura and preparation method]
About the character of material with carbon element, comprise cathode of carbon material electrode, electric polarization method, collector body and lithium secondary battery, preferred satisfy simultaneously below shown in (1)～(9) in wantonly 1 or multinomial.
(1) X ray parameter
Material with carbon element is preferably more than the 0.335nm through the d value (interfloor distance) of the lattice plane (002) that X-ray diffraction that adopt to learn the method for shaking is tried to achieve, and its upper limit is generally below the 0.36nm, is preferably below the 0.35nm, more preferably below the 0.345nm.In addition, the crystallite size (Lc) of the material with carbon element of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is preferably more than the 1nm, more preferably more than the 1.5nm.
(2) ash content
Contained ash content is preferably below the 1 quality % with respect to the gross mass of carbonaceous material in the carbonaceous material, more preferably below the 0.5 quality %, is preferably especially below the 0.1 quality %, as lower limit, is preferably more than the 1ppm.If surpass above-mentioned scope, the deterioration of the battery performance that causes owing to the reaction with nonaqueous electrolytic solution when then discharging and recharging can not be ignored.If be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
(3) volume reference average grain diameter
The volume reference average grain diameter of carbonaceous material is the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method, is generally more than the 1 μ m, is preferably more than the 3 μ m, more preferably more than the 5 μ m, further is preferably more than the 7 μ m.In addition, its upper limit is generally below the 100 μ m, is preferably below the 50 μ m, more preferably below the 40 μ m, further is preferably below the 30 μ m, is preferably especially below the 25 μ m.If be lower than above-mentioned scope, then irreversible capacity increases, and causes the loss of initial stage battery capacity sometimes.In addition, if surpass above-mentioned scope, when then making electrode through coating, forming uneven coated face easily, is not preferred sometimes on the battery production process.
In the present invention; The volume reference average grain diameter defines with median particle diameter; Said median particle diameter is measured through following method: carbon dust is dispersed in the 0.2 quality % aqueous solution (about 10mL) of polyoxyethylene (20) Span-20 as surfactant; Use laser diffraction/diffuse transmission type particle size distribution meter (for example, the hole field makes the LA-700 of institute's manufactured) to measure.
(4) Raman R value, Raman half breadth
Use the R value of the carbonaceous material of argon laser Raman light method mensuration to be generally more than 0.01, be preferably more than 0.03, more preferably more than 0.1; Be limited to below 1.5 on it; Be preferably below 1.2, more preferably below 1.0, further be preferably the scope below 0.5.If the R value is lower than this scope, then the crystallinity of particle surface is too high, along with the site (サ イ ト) that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.In addition, be coated on the collector body after, when making the negative pole densification through compacting, crystallization is oriented to the direction parallel with battery lead plate easily, causes part throttle characteristics to reduce sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of nonaqueous electrolytic solution, causes the gas of efficient reduction or generation to increase sometimes.
In addition, carbonaceous material is at 1580cm -1Near Raman half breadth has no particular limits, and is generally 10cm -1More than, be preferably 15cm -1More than, its upper limit is generally 100cm -1Below, be preferably 80cm -1Below, 60cm more preferably -1Below, further be preferably 40cm -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, along with the site (サ イ ト) that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.In addition, be coated on the collector body after, when making the negative pole densification through compacting, crystallization is oriented to the direction parallel with battery lead plate easily, causes part throttle characteristics to reduce sometimes.On the other hand, if be higher than this scope, then the crystallinity of particle surface reduces, with the reactivity increase of nonaqueous electrolytic solution, and the gas increase that causes efficient to reduce sometimes or produce.
The mensuration of Raman spectrum is carried out as follows: use raman spectroscopy device (the raman spectroscopy device of for example Japanese beam split manufactured); Sample is fallen naturally and be filled in the cell (cell); To the specimen surface in pond irradiation argon laser, make simultaneously the pond with the face of laser vertical in rotate.For the Raman spectrum that obtains, measure 1580cm -1Near peak P AIntensity I AAnd 1360cm -1Near peak P BIntensity I B, calculate its strength ratio R (R=I B/ I A), it is defined as the Raman R value of carbonaceous material.In addition, measure the Raman spectrum obtain at 1580cm -1Near peak P AHalf breadth, it is defined as the Raman half breadth of carbonaceous material.
In addition, the Raman condition determination here is following.
Argon laser wavelength: 514.5nm
Laser power on the sample: 15～25mW
Resolution: 10～20cm -1
Measurement range: 1100cm -1～1730cm -1
R value, half breadth analysis: background (background) is handled
Smooth (smoothing) handles: simple average, convolution 5 points (コ Application ボ リ ユ シ ヨ Application 5 Port イ Application ト)
(5) BET specific area
Use the specific area of the carbonaceous material of the present invention of BET method mensuration to be generally 0.1m 2More than/the g, be preferably 0.7m 2More than/the g, 1.0m more preferably 2More than/the g, further be preferably 1.5m 2More than/the g.Its upper limit is generally 100m 2Below/the g, be preferably 25m 2Below/the g, 15m more preferably 2Below/the g, further be preferably 10m 2Below/the g.If the value of specific area is lower than above-mentioned scope, then as under the situation of negative pole, the acceptance variation of lithium when charging, lithium is separated out at electrode surface easily.On the other hand, if be higher than above-mentioned scope, during then as negative material, with the reactivity increase of nonaqueous electrolytic solution, it is many that the gas of generation becomes easily, is difficult to obtain preferred battery sometimes.
The specific area that adopts the BET method to measure is used the following value of measuring: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation, under 350 ℃ to sample carry out 15 minutes predrying, then; Use nitrogen accurately to be adjusted into 0.3 nitrogen helium gas mixture body, measure through the nitrogen absorption BET1 point method that adopts the gas flow method with respect to atmospheric relative pressure value.
(6) micropore diameter distributes
The micropore diameter of the carbonaceous material that uses among the present invention distribute be through the space in mercury porosimeter (mercury penetration method) being equivalent to of trying to achieve the particle that micro-pore diameter is 0.01 μ m～1 μ m, since the amount of concavo-convex, the interparticle contact-making surface that causes of being uneven of particle surface etc. as more than the 0.01mL/g; Be preferably more than the 0.05mL/g; More preferably more than the 0.1mL/g; Be limited on it below 0.6mL/g, be preferably below the 0.4mL/g, more preferably the scope below the 0.3mL/g.If surpass this scope, then when making pole plate, need a large amount of adhesives sometimes.If be lower than this scope, then the high current density charge-discharge characteristic reduces, and, the alleviation effects that the electrode in the time of can not obtaining discharging and recharging sometimes expands and shrinks.
In addition, the total micropore volume that is equivalent to the micropore diameter of 0.01 μ m～100 mu m ranges is preferably more than the 0.1mL/g, more preferably more than the 0.25mL/g; Further be preferably more than the 0.4mL/g; Be limited on it below 10mL/g, be preferably below the 5mL/g, more preferably the scope below the 2mL/g.If be higher than this scope, then when making pole plate, need a large amount of adhesives sometimes.If be lower than this scope, then when making pole plate, can not obtain the dispersion effect of thickener or binding agent sometimes.
In addition, average micropore diameter is preferably more than the 0.05 μ m, more preferably more than the 0.1 μ m, further is preferably more than the 0.5 μ m, is limited on it below 50 μ m, is preferably below the 20 μ m, more preferably the scope below the 10 μ m.If surpass this scope, then need a large amount of adhesives sometimes.If be lower than this scope, then the high current density charge-discharge characteristic reduces sometimes.
Device as as the mercury porosimeter can use mercury void determination appearance (autopore (オ one ト Port ア) 9520; Micrometritics (マ イ Network ロ メ リ テ Star Network ス) manufactured).About 0.2g sample is encapsulated into powder with in the container, carries out the degassing in 10 minutes, carry out pre-treatment at (below the 50 μ mHg) under room temperature, the vacuum.Then, be decompressed to 4psia (about 28kPa), import mercury, boost to 40000psia (about 280MPa) from 4psia (about 28kPa) stage shape after, be depressurized to 25psia (about 170kPa) again.Number of stages when boosting is more than 80 stages, in each stage, after 10 seconds equilibration time, measures the mercury amount of being pressed into.Use the Washburn formula to be pressed into opisometer and calculate the micropore diameter distribution from the mercury that obtains like this.In addition, the surface tension of mercury (γ) is 485dyne/cm, and contact angle (φ) is 140 °.Average micropore diameter uses the accumulation micro pore volume to reach 50% o'clock micropore diameter.
(7) circularity
Use the degree of circularity as the sphere of carbonaceous material, its particle diameter is that the circularity of the particle of 3～40 mu m ranges is preferably more than 0.1, is preferably especially more than 0.5, more preferably more than 0.8, further is preferably more than 0.85, most preferably is more than 0.9.When circularity was big, the high current density charge-discharge characteristic improved, and is therefore preferred.
Circularity defines with following formula, and circularity is 1 o'clock, is theoretical proper sphere.
Circularity=(having girth)/(perimeter of particle projection of shape) with particle projection of shape equivalent circular of the same area
Use the following value of measuring as the value of circularity: for example use flow-type particle picture analytical equipment (for example; The FPIA of Sysmex Industrial (シ ス メ Star Network ス イ Application ダ ス ト リ ア Le) manufactured); About 0.2g sample is scattered in the 0.2 quality % aqueous solution (about 50mL) of polyoxyethylene (20) Span-20 as surfactant; Behind the ultrasonic wave with 1 minute 28kHz of the power output of 60W irradiation; Specifying 0.6～400 μ m is detection range, and the particle of particle diameter 3～40 mu m ranges is measured.
The method that improves circularity has no particular limits, but handles (mechanical energy processings) and make it to become sphere the shape of inter-particle voids is neatly unified through implementing spheroidization, so preferably.As the example that spheroidization is handled, can enumerate, through apply shearing force, compression stress is come the mechanically method of subglobular, the adhesive force that has through adhesive or particle self is with the machinery/physical treatment method of a plurality of particulate granulations etc.
(8) real density
The real density of carbonaceous material is generally 1.4g/cm 3More than, be preferably 1.6g/cm 3More than, 1.8g/cm more preferably 3More than, further be preferably 2.0g/cm 3More than, be limited to 2.26g/cm on it 3Below.On be limited to the theoretical value of graphite.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.In the present invention, real density is defined as the value of measuring through the liquid phase displacement method (hydrometer method) of using butanols.
(9) tap density
The tap density of carbonaceous material is generally 0.1g/cm 3More than, be preferably 0.5g/cm 3More than, 0.7g/cm more preferably 3More than, be preferably 1.0g/cm especially 3More than.In addition, its upper limit is preferably 2g/cm 3Below, 1.8g/cm more preferably 3Below, be preferably 1.6g/cm especially 3Below.If tap density is lower than this scope, when then using as negative pole, packed density is difficult to improve, and can not obtain the battery of high power capacity sometimes.On the other hand, if surpass this scope, then the interparticle space in the electrode is very few, is difficult to guarantee interparticle conductivity, is difficult to obtain preferred battery behavior sometimes.Tap density through with positive pole in the same method of method set forth measure, and through this method definition.
(10) orientation ratio
The orientation ratio of carbonaceous material is generally more than 0.005, is preferably more than 0.01, more preferably more than 0.015, is limited to the scope of theoretical value below 0.67 on it.If be lower than this scope, then the high density charge-discharge characteristic can reduce sometimes.
Orientation ratio is after with the sample extrusion forming, to measure through X-ray diffraction.The 0.47g sample is filled in the make-up machine of diameter 17mm, with 600kgf/cm 2Compression obtains formed body, the fixing above-mentioned formed body of use clay, and making it is with one side with measuring the face that uses the sample retainer, measures X-ray diffraction then.Calculate with the ratio that (110) diffraction integral intensity/(004) diffraction integral intensity is represented from (110) diffraction of the carbon that obtains and the peak intensity of (004) diffraction, this ratio is defined as the orientation ratio of active material.
The X-ray diffraction condition determination here is following.In addition, " 2 θ " expression angle of diffraction.
The monochromatic photometer of target: Cu (K alpha ray) graphite
Slit:
Divergent slit=0.5 degree receives optical slits=0.15mm, scatter slit=0.5 degree
Measurement range and step angle/minute
(110) face: 75 degree≤2 θ≤80 degree 1 are spent/60 seconds
(004) face: 52 degree≤2 θ≤57 degree 1 are spent/60 seconds
(11) draw ratio (powder)
Draw ratio is more than 1 in theory, on be limited to below 10, be preferably below 8, more preferably below 5.If surpass the upper limit, produce striped when then making pole plate sometimes, can't obtain uniform coated face, the high current density charge-discharge characteristic reduces.
The ratio A/B of the major diameter A of carbonaceous material particle and perpendicular minor axis B represented when in addition, draw ratio was with three dimensional viewing.The observation of carbon particle is carried out through the scanning electron microscope that can amplify observation.Selection is fixed on any 50 graphite particles on the end face of the metallic plate of thickness below 50 microns, rotation, tilts to be fixed with the objective table of sample, measures A, the B of these particles respectively, obtains the mean value of A/B.
(12) auxiliary material mixes
So-called " auxiliary material mixing " is meant in the negative electrode and/or contains the carbonaceous material of different in kind more than 2 kinds in the negative electrode active material.Here said character is meant the more than one characteristic in X-ray diffraction parameter, median particle diameter, draw ratio, BET specific area, orientation ratio, Raman R value, tap density, real density, micropore distribution, circularity, the ash amount.
As especially preferred embodiment, can enumerate, the volume reference particle size distribution is asymmetric about when being the center with the median particle diameter, it is not equal to contain Raman R value is different more than 2 kinds carbonaceous material or X ray parameter.
As an example of its effect, can enumerate, through containing graphite such as native graphite, Delanium; Carbon blacks such as acetylene black; Carbonaceous materials such as amorphous carbon such as needle coke can reduce resistance as conductive agent.They can use separately, also can use more than 2 kinds with combination in any and arbitrary proportion combination.When adding, be more than the 0.1 quality %, be preferably more than the 0.5 quality %, more preferably more than the 0.6 quality %, be limited on it below 45 quality %, be preferably the scope of 40 quality % as conductive agent.If be lower than this scope, then be difficult to obtain the effect that conductivity improves sometimes.If be higher than above-mentioned scope, then cause the increase of initial stage irreversible capacity sometimes.
(13) electrode is made
Make electrode and can adopt usual way.For example, in negative electrode active material, add adhesive, solvent, the thickener that adds as required, electric conducting material, packing material etc., process slurry, it is coated on the collector body, dry back forms electrode through compacting.In stage before the nonaqueous electrolytic solution injection process, the thickness of every negative electrode active material of battery is generally more than the 15 μ m, is preferably more than the 20 μ m; More preferably more than the 30 μ m; Be limited on it below 150 μ m, be preferably below the 120 μ m, more preferably below the 100 μ m.If surpass this scope, then nonaqueous electrolytic solution is difficult to be impregnated into the collector body near interface, and therefore, the high current density charge-discharge characteristic reduces.In addition, if be lower than this scope, then collector body increases with respect to the volume ratio of negative electrode active material, and battery capacity reduces sometimes.In addition, can negative electrode active material be carried out the roller moulding and process pellet electrode, or process mosaic electrode through compression forming.
(14) collector body
As collector body, can at random use known collector body.As the collector body of negative pole, can enumerate, metal materials such as copper, nickel, stainless steel, nickel-plated steel, wherein, and from the viewpoint of handling ease and cost, preferably copper.When the shape of collector body is metal material at collector body, can enumerate metal forming, metal cylinder, wire coil, metallic plate, metallic film, expansion alloy, perforated metal, foaming metal etc.Wherein, preferable alloy film, more preferably Copper Foil, further preferred rolling process rolled copper foil that makes and the electrolytic copper foil that adopts electrolysis to make of adopting, any one can use as collector body.When the thickness of Copper Foil is thinner than 25 μ m, can use the copper alloy higher (phosphor bronze, titanium copper, Corson alloy, Cu-Cr-Zr alloy etc.) than fine copper intensity.In addition, therefore aluminium foil preferably uses because its light specific gravity when therefore being used in collector body, can reduce the weight of battery.
In the collector body that adopts the rolling process copper foil manufactured to make, because the copper crystallization arranges at rolling direction, even with closely bending or negative pole is bent into acute angle of negative pole, easy fracture not is applicable to small cylinder shape battery.Electrolytic copper foil makes as follows: for example, the drum that impregnating metal is made in being dissolved with the nonaqueous electrolytic solution of copper ion, the limit makes this drum rotation limit circulating current, and copper is separated out on the surface of drum, it is peeled off again.Can also separate out copper through electrolysis on the surface of above-mentioned rolled copper foil.Can carry out roughened or surface treatment (for example, thickness is bottom layer treatment of chromate processing, Ti etc. about several nm～1 μ m etc.) to the one or both sides of Copper Foil.
For the collector body substrate, require to have following rerum natura.
(1) average surface roughness (Ra)
The average surface roughness (Ra) that the active material film of the collector body substrate of stipulating in the method according to JIS B 0601-1994 record forms face has no particular limits; But be generally more than the 0.05 μ m; Be preferably more than the 0.1 μ m, be preferably especially more than the 0.15 μ m, its upper limit is generally below the 1.5 μ m; Be preferably below the 1.3 μ m, be preferably especially below the 1.0 μ m.Through the scope of average surface roughness (Ra) between the above-mentioned lower limit and the upper limit that makes the collector body substrate, can expect the favorable charge-discharge cycle characteristics.Through being set at more than the above-mentioned lower limit, big with the interfacial area change of active material film, with the adaptation raising of active material.The higher limit of average surface roughness (Ra) has no particular limits, and when average surface roughness (Ra) surpasses 1.5 μ m, is difficult to obtain the paper tinsel as the battery suitable thickness, therefore is preferably below the 1.5 μ m.
(2) hot strength
The hot strength of collector body substrate has no particular limits, but is generally 100N/mm 2More than, be preferably 250N/mm 2More than, 400N/mm more preferably 2More than, be preferably 500N/mm especially 2More than.So-called hot strength is meant the value that needed maximum pull obtained divided by the sectional area of test film when test film reached fracture.Hot strength among the present invention can adopt and measure the same apparatus and method of percentage elongation and measure.If the high collector body substrate of hot strength, the be full of cracks of the collector body substrate that causes owing to active material film expansion in the time of then can suppressing charge/discharge, thus can obtain good cycle characteristics.
(3) 0.2% endurance
0.2% endurance of collector body substrate has no particular limits, but is generally 30N/mm 2More than, be preferably 150N/mm 2More than, be preferably 300N/mm especially 2More than.So-called 0.2% endurance is meant that producing 0.2% plasticity (forever) is out of shape needed payload, apply the load of this size after, remove load and also can keep 0.2 distortion.0.2% endurance among the present invention can be through measuring with the identical apparatus and method of mensuration percentage elongation.If the high collector body substrate of 0.2% endurance, the plastic deformation of the collector body substrate that causes owing to active material film expansion in the time of then can suppressing charge/discharge, thus can obtain good cycle characteristics.
The thickness of metallic film is arbitrarily, is generally more than the 1 μ m, is preferably more than the 3 μ m, more preferably more than the 5 μ m.In addition, its upper limit is generally below the 1mm, is preferably below the 100 μ m, more preferably below the 30 μ m.If thinner than 1 μ m, then intensity reduces, coating difficulty sometimes.In addition, if thicker, then make the shape of electrode that the curling distortion that waits takes place sometimes than 100 μ m.In addition, metallic film also can be netted.
(15) ratio of the thickness of collector body and active material layer
The ratio of the thickness of collector body and active material layer has no particular limits; (injecting the thickness of a nonaqueous electrolytic solution side active material layer before)/(thickness of collector body) is preferably below 150; Be preferably especially below 20, more preferably below 10, its lower limit is preferably more than 0.1; More preferably below 0.4, further be preferably the scope more than 1.If surpass this scope, when then high current density discharged and recharged, collector body produced heating sometimes because of Joule heat.If be lower than this scope, then collector body is with respect to the volume ratio increase of negative electrode active material sometimes, and the capacity of battery reduces.
(16) electrode density
Electrode structure when negative electrode active material is processed electrode has no particular limits, and the density that is present in the active material on the collector body is preferably 1.0g/cm 3More than, 1.2g/cm more preferably 3More than, further be preferably 1.3g/cm 3More than, its upper limit is generally 2.0g/cm 3Below, be preferably 1.9g/cm 3Below, 1.8g/cm more preferably 3Below, further be preferably 1.7g/cm 3Following scope.If surpass this scope, then active material is destroyed, and causes initial stage irreversible capacity increase, near the impregnability of nonaqueous electrolytic solution collector body/reactive species interface to reduce, thereby causes the high current density charge-discharge characteristic to worsen.In addition, if be lower than this scope, then the conductivity between active material descends, and cell resistance increases, and the battery capacity of unit volume reduces sometimes.
(17) adhesive
As the adhesive of bonding active material,, have no particular limits so long as the material of the solvent-stable that uses to nonaqueous electrolytic solution or when making electrode gets final product.Particularly, can enumerate resinae macromolecules such as polyethylene, polypropylene, PETG, polymethyl methacrylate, aromatic polyamide, cellulose, NC Nitroncellulose; Rubber-like macromolecules such as SBR (butadiene-styrene rubber), isoprene rubber, butadiene rubber, fluorubber, NBR (acrylonitrile-butadiene rubber), styrene-propene rubber; SBS or its hydrogenation thing; Thermoplastic elastomer (TPE) shape macromolecules such as EPDM (ethylene-propylene-diene terpolymer), SIS/SEBS, styrene-isobutene-styrene block copolymer or its hydrogenation thing; Soft resinous macromolecules such as syndiotactic 1,2 polybutadiene, polyvinyl acetate, ethylene-vinyl acetate copolymer, propylene-alpha-olefin copolymers; Kynoar, polytetrafluoroethylene, fluoridize fluorine family macromolecules such as Kynoar, polytetrafluoroethylene-ethylene copolymer; Polymeric composition etc. with ionic conductivity of alkali metal ion (particularly lithium ion).They can use a kind of separately, also can use more than 2 kinds with combination in any and ratio combination.
As the solvent that is used to form slurry; So long as can dissolve or dispersed activity material, adhesive and the thickener that uses as required and the solvent of conductive agent get final product; Its kind has no particular limits, and can use in water solvent or the organic kind solvent any.As the example of water solvent, can enumerate water, alcohol etc.; Example as organic kind solvent; Can enumerate N-methyl pyrrolidone (NMP), dimethyl formamide, dimethylacetylamide, MEK, cyclohexanone, methyl acetate, methyl acrylate, diethyl triamine, N, N-dimethylamino propylamine, expoxy propane, oxolane (THF), toluene, acetone, ether, dimethylacetylamide, hexamethyl phosphoramide, dimethyl sulfide, benzene, xylenes, quinoline, pyridine, methyl naphthalene, hexane etc.Particularly when using water solvent, add above-mentioned thickener and dispersant etc. simultaneously, the latex of use SBR etc. carry out slurryization.In addition, they can use a kind of separately, also can use more than 2 kinds with combination in any and ratio combination.
Adhesive is preferably more than the 0.1 quality % with respect to the ratio of active material; Be preferably especially more than the 0.5 quality %; More preferably more than the 0.6 quality %, its upper limit is generally below the 20 quality %, is preferably below the 15 quality %; More preferably below the 10 quality %, further be preferably the scope below the 8 quality %.If surpass this scope, then can not bring the adhesive ratio of help to increase in the amount of adhesive to battery capacity, cause battery capacity to reduce sometimes.In addition, if be lower than above-mentioned scope, then cause the intensity of negative electrode to reduce sometimes.Particularly; Contain in the main component with SBR when being the rubber-like macromolecule of representative, adhesive is generally more than the 0.1 quality % with respect to the ratio of active material, is preferably more than the 0.5 quality %; More preferably more than the 0.6 quality %; Its upper limit is generally below the 5 quality %, is preferably below the 3 quality %, more preferably the scope below the 2 quality %.In addition; Contain in the main component with the Kynoar when being the fluorine family macromolecule of representative, adhesive is generally more than the 1 quality % with respect to the ratio of active material, is preferably more than the 2 quality %; More preferably more than the 3 quality %; Its upper limit is generally below the 15 quality %, is preferably below the 10 quality %, more preferably below the 8 quality %.
Thickener normally uses for the viscosity of regulating slurry.As thickener, have no particular limits, particularly, can enumerate carboxymethyl cellulose, methylcellulose, CMC, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and their salt etc.They can use a kind of separately, also can use more than 2 kinds with combination in any and ratio combination.In addition, when adding thickener, thickener is generally more than the 0.1 quality % with respect to the ratio of active material; Be preferably more than the 0.5 quality %, more preferably more than the 0.6 quality %, its upper limit is generally below the 5 quality %; Be preferably below the 3 quality %, more preferably the scope below the 2 quality %.If be lower than this scope, then coating significantly reduces sometimes.If surpass this scope, then the ratio of the shared active material of negative electrode active material layer reduces, and produces the problem that problem that battery capacity reduces or the resistance between the negative electrode active material increase sometimes.
(18) pole plate orientation ratio
The pole plate orientation ratio is preferably more than 0.001, more preferably more than 0.005, be preferably especially more than 0.01, on be limited to theoretical value, promptly below 0.67.If be lower than this scope, then the high density charge-discharge characteristic reduces sometimes.
The mensuration of pole plate orientation ratio is carried out as follows.Measure the active material orientation ratio of electrode through X-ray diffraction to being pressed into negative electrode after the target density.The not special restriction of concrete grammar; Method as standard; Use asymmetric Pearson (ピ ア ソ Application) VII as (profile) function that distributes; (110) diffraction of the carbon that match obtains through X-ray diffraction and the peak of (004) diffraction carry out the peak and separate, and calculate the integrated intensity at the peak of (110) diffraction and (004) diffraction respectively.By the integrated intensity that obtains, calculate ratio by (110) diffraction integral intensity/(004) diffraction integral intensity is represented.The active material orientation ratio of the electrode that this mensuration is calculated is defined as the pole plate orientation ratio.
The X-ray diffraction condition determination here is following.In addition, " 2 θ " expression angle of diffraction.
The monochromatic photometer of target: Cu (K α line) graphite
Slit: divergent slit=1 degree receives optical slits=0.1mm, scatter slit=1 degree
Measurement range and step angle/minute
(110) face: 76.5 degree≤2 θ≤78.5 degree 0.01 are spent/3 seconds
(004) face: 53.5 degree≤2 θ≤56.0 degree 0.01 are spent/3 seconds
Specimen preparation: the two-sided tape thick with 0.1mm is fixed on electrode on the glass plate
(19) impedance
60% o'clock the negative pole impedance that is charged to nominal capacity from discharge condition is preferably below 100 Ω, more preferably below 50 Ω, be preferably especially below 20 Ω, and/or the electric double layer capacity is preferably 1 * 10 -6More than the F, more preferably 1 * 10 -5F is preferably 1 * 10 especially -4F.This scope output characteristic is good, so preferred.
Negative pole resistance and electric double layer capacity are measured according to following method.Lithium secondary battery to be determined uses following battery: with after can charging with the current value that charged to nominal capacity in 5 hours; Keep the state that did not did not discharge and recharge in 20 minutes; Then; With discharging with 1 hour current value with the nominal capacity discharge, the capacity of this moment is more than 80% of nominal capacity.For the lithium secondary battery of above-mentioned discharge condition,, immediately lithium secondary battery is transferred in the spherical container under the argon atmosphere through being charged to 60% of nominal capacity with the current value that charged to nominal capacity in 5 hours.Do not discharge or the state of not short circuit under rapidly this lithium secondary battery is disintegrated; Take out negative pole; If the double spread electrode, electrode active material that so will one side is peeled off and is not damaged the electrode active material of another side, and 2 negative electrode stamping-outs are become 12.5mm φ; Sandwich dividing plate, make the active material face not have mistake liftoff opposed.Between dividing plate and two negative poles, drip the nonaqueous electrolytic solution 60 μ L that use in the battery, carry out bondingly, keep not and extraneous state of contact, make the collector body conduction of two negative poles, implement AC impedence method.Measure and carry out as follows, under 25 ℃ temperature, 10 -2～10 5The frequency band of Hz is measured complex impedance, and the circular arc of the negative pole resistance components of the callcallplot that tries to achieve is approximately semicircle, obtains sheet resistance (R) and electric double layer capacity (Cdl).
(20) area of negative plate and thickness
The area of negative plate has no particular limits, and is usually designed to greatlyyer slightly than opposed positive plate, makes positive plate can not be exposed to negative plate outside.From the cycle life of repeated charge or suppress because high temperature is preserved the viewpoint of the deterioration that causes; If as far as possible near the area that equates with positive pole; The electrode ratio that can further improve evenly and work effectively so, thus characteristic is improved, therefore preferred.Particularly, when using with big electric current, the design of this electrode area is important.
The thickness of negative plate designs according to the positive plate that uses; Have no particular limits, but the thickness that deducts the plied timber layer after the metal foil thickness of core is generally more than the 15 μ m, is preferably more than the 20 μ m; More preferably more than the 30 μ m; Its upper limit is generally below the 150 μ m, is preferably below the 120 μ m, more preferably below the 100 μ m.
< negative pole [1] >
Below, the negative pole [1] that uses in the lithium secondary battery of the present invention " is contained more than 2 kinds the negative pole as the different carbonaceous material of the crystallinity of negative electrode active material " describe.
[negative electrode active material of negative pole [1]]
Below, the negative electrode active material that negative pole [1] uses is described.
[[formation]]
The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [1] is characterised in that and contains the different carbonaceous material of crystallinity more than 2 kinds.Here; " contain the different carbonaceous material of crystallinity more than 2 kinds " and represent that coexistence has the different carbonaceous material of crystallinity in the negative pole; In addition; Its coexistence form can be the state that exists and mix with the form of single particle one by one, or is included in the offspring, or the mixing of said two devices.In addition; As negative electrode active material; Preferably contain the composite carbonaceous material that comprises the carbonaceous material that crystallinity is different more than 2 kinds, more preferably in this composite carbonaceous material, also contain more than one with this composite carbonaceous material in carbonaceous material (carbonaceous material) different aspect the rerum natura of carbonaceous as auxiliary material.
Here the different carbonaceous material of said " being included in the offspring " expression crystallinity is constrained in the state of together state, physical constraint, keeps the state of shape etc. through electrostatic confinement by bonding.Here the different a kind of carbonaceous material of said " physical constraint " expression crystallinity is mingled with the state in the another kind of carbonaceous material, the state that tangles each other, and the different a kind of carbonaceous material of so-called " electrostatic confinement " expression crystallization is attached to the state on the another kind of carbonaceous material through electrostatic energy.In addition, chemical bonds such as " through the state of bonding constraint " expression hydrogen bond, covalent bond, ionic bond.
Wherein, the part surface at least that becomes the carbonaceous material of core has under the state at the tectal interface different with the crystallinity that forms through bonding, and the mobile impedance of the lithium between the different carbonaceous material of crystallinity is little, so favourable.This cover layer can be through forming with the material of supplying with from the outside and/or the bonding of their modifier, and perhaps the modification of the material of the surface element through carbonaceous material forms.Here; The so-called covering; At least a portion in the interface on the surface of expression and carbonaceous material has chemical bond, and shows that (1) covers the state of all surfaces, optionally state, (4) on surface, cover part are present in the interior state of very small region that contains chemical bond to local state, (3) of (2) coated carbon particle.In addition, crystallinity can change continuously on the interface, also can discontinuously change.
Composite carbonaceous material preferably have be coated with interface that crystallinity forms with this different carbonaceous material of particle shape carbonaceous material on the particle shape carbonaceous material and/or on particle shape carbonaceous material bonding crystallinity and this different carbonaceous material of particle shape carbonaceous material are arranged and the interface that forms, and the crystallinity at this interface is continuous and/or discontinuous variation.Which the high this point of crystallinity of " particle shape carbonaceous material " and " with the different carbonaceous material of this particle shape carbonaceous material crystallinity " does not have special qualification; But when the crystallinity of particle shape carbonaceous material is high; Can realize above-mentioned effect of the present invention, so preferred.
Here; Crystalline difference is judged through the difference of the interplanar distance (d002) of (002) face of employing X ray wide-angle diffraction method mensuration, the difference of Lc, the difference of La; This puts from showing effect of the present invention; Preferred crystalline difference is counted more than the 0.0002nm with (d002), and perhaps La is more than the 1nm, and perhaps Lc is more than the 1nm.In the above-mentioned scope, difference (d002) is preferably more than the 0.0005nm, more preferably more than the 0.001nm, further is preferably more than the 0.003nm, and its upper limit is generally below the 0.03nm, is preferably the scope below the 0.02nm.If be lower than this scope, the effect that is caused by crystalline difference diminishes sometimes.On the other hand, if surpass above-mentioned scope, the crystallinity of the part that then crystallinity is low has the tendency of step-down, and the irreversible capacity that causes thus may increase.In addition, in the above-mentioned scope, the difference of La or Lc is preferably more than the 2nm, more preferably more than the 5nm, further is preferably the above scope of 10nm.Usually, graphite can not define more than 100nm, therefore can not specify the upper limit.If be lower than this scope, the caused effect of then crystalline difference diminishes sometimes.
Composite carbonaceous material be on particle shape carbonaceous material, cover and/or bonding crystallinity form with the different carbonaceous material of this particle shape carbonaceous material; " particle shape carbonaceous material " needs only any one with " with the different carbonaceous material of this particle shape carbonaceous material crystallinity " is the graphite-like carbonaceous material; And another to be the low-crystalline carbonaceous material get final product; In addition; Preferably " particle shape carbonaceous material " is the graphite-like carbonaceous material, and " with the different carbonaceous material of this particle shape carbonaceous material crystallinity " is the low-crystalline carbonaceous material.
[[[particle shape carbonaceous material]]]
As particle shape carbonaceous material, preferably contain the graphite-like carbonaceous material of native graphite and/or Delanium, or contain be selected from than the low slightly (a) and (b) of they crystallinity with (c) in carbonaceous material one of at least,
(a) be selected from organic pyrolysate in coal class coke, petroleum-type coke, furnace black, acetylene black and the pitch-based carbon fiber;
(b) carbide of organic gas;
(c) with (a) or a part (b) or all carry out graphitization and the carbonaceous material that obtains.
[[[[graphite-like carbonaceous material]]]]
Particle shape carbonaceous material preferably contains the graphite-like carbonaceous material of native graphite and/or Delanium.The graphite-like carbonaceous material is meant that the interplanar distance (d002) of (002) face that adopts X ray wide-angle diffraction method mensuration shows the high various carbonaceous material of crystallinity of not enough 0.340nm.
As the object lesson of graphite-like carbonaceous material, be preferably selected from the powder of following product: native graphite, Delanium or their mechanical disintegration thing, the heat treated article again of heat treated article, expanded graphite or the high-purity purified product of these graphite again.Object lesson as above-mentioned Delanium; Preferably the organic substance with more than one carries out graphitization usually under the sintering temperature about 2500 ℃～3200 ℃; Carry out the material that powdered obtains through suitable breaking method again, said organic substance is selected from: coal tar asphalt, coal class heavy oil, atmospheric resids, petroleum-type heavy oil, aromatic hydrocarbon, nitrogenous cyclic compound, sulphur-containing cyclic compound, polyphenyl, polyvinyl chloride, polyvinyl alcohol, polyacrylonitrile, polyvinyl butyral resin, natural polymer, polyphenylene sulfide, polyphenylene oxide, furfuryl alcohol resin, phenolic resins, imide resin etc.
(rerum natura of graphite-like carbonaceous material)
The character of graphite-like carbonaceous material is preferred satisfy simultaneously below shown in (1)～(11) in any one or multinomial.
(1) X ray parameter
The graphite-like carbonaceous material is preferably more than the 0.335nm through the d value (interfloor distance) of the lattice plane (002) that X-ray diffraction that adopt to learn the method for shaking is tried to achieve.In addition,, be limited to not enough 0.340nm down, be preferably below the 0.337nm from definition.If the d value is excessive, then crystallinity reduces, and increases the initial stage irreversible capacity sometimes.On the other hand, 0.335 is the theoretical value of graphite.In addition, the crystallite size (Lc) of the material with carbon element of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is generally more than the 30nm, is preferably more than the 50nm, more preferably the above scope of 100nm.If be lower than this scope, then crystallinity reduces, and might increase the initial stage irreversible capacity.
(2) ash content
Contained ash content is preferably below the 1 quality % with respect to the gross mass of graphite-like carbonaceous material in the graphite-like carbonaceous material, more preferably below the 0.5 quality %, below the preferred especially 0.1 quality %, is limited to more than the 1ppm down.If surpass above-mentioned scope, can not ignore with the reaction of electrolyte and the deterioration of the battery performance that causes when then discharging and recharging.If be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
(3) volume reference average grain diameter
The volume reference average grain diameter of graphite-like carbonaceous material is the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method, is generally more than the 1 μ m, is preferably more than the 3 μ m, more preferably more than the 5 μ m, further is preferably more than the 7 μ m.In addition, its upper limit is generally below the 100 μ m, is preferably below the 50 μ m, more preferably below the 40 μ m, further is preferably below the 30 μ m, is preferably especially below the 25 μ m.If be lower than above-mentioned scope, then irreversible capacity increases, and causes the loss of initial stage battery capacity sometimes.In addition, if surpass above-mentioned scope, then when processing electrode pad, forming uneven coated face easily, is not preferred sometimes on the battery production process.
In the present invention; The volume reference average grain diameter defines with median particle diameter; Said median particle diameter is measured through following method: carbon dust is dispersed in the 0.2 quality % aqueous solution (about 1mL) of polyoxyethylene (20) Span-20 as surfactant; Use laser diffraction/diffuse transmission type particle size distribution meter (for example, the hole field makes the LA-700 of institute's manufactured) to measure.
(4) Raman R value, Raman half breadth
Use the R value of the graphite-like carbonaceous material of argon laser Raman spectroscopy mensuration to be generally more than 0.01, be preferably more than 0.03, more preferably more than 0.10, its upper limit is generally below 0.60, is preferably the scope below 0.40.If the R value is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of electrolyte, causes the gas of efficient reduction or generation to increase sometimes.
In addition, the graphite-like carbonaceous material is at 1580cm -1Near Raman half breadth has no particular limits, and is generally 10cm -1More than, preferred 15cm -1More than, the upper limit is generally 60cm -1Below, be preferably 45cm -1Below, 40cm more preferably -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if be higher than this scope, then the crystallinity of particle surface reduces, with the reactivity increase of electrolyte, and the gas increase that causes efficient to reduce sometimes or produce.
The mensuration of Raman spectrum is carried out as follows: use raman spectroscopy device (the raman spectroscopy device that for example Japanese beam split society makes); Sample is fallen naturally and be filled in the cell; To the specimen surface in pond irradiation argon laser, simultaneously, make the pond with the face of laser vertical in rotate.For the Raman spectrum that obtains, measure 1580cm -1Near peak P AIntensity I AAnd 1360cm -1Near peak P BIntensity I B, calculate its strength ratio R (R=I B/ I A), it is defined as the Raman R value of material with carbon element.In addition, measure the Raman spectrum obtain at 1580cm -1Near peak P AHalf breadth, it is defined as the Raman half breadth of material with carbon element.
In addition, the Raman condition determination here is following.
Argon laser wavelength: 514.5nm
Laser power on the sample: 15～25mW
Resolution: 10～20cm -1
Measurement range: 1100cm -1～1730cm -1
R value, half breadth analysis: background is handled
Smooth treatment: simple average, convolution 5 points
(5) BET specific area
Use the specific area of the graphite-like carbonaceous material of the present invention of BET method mensuration to be generally 0.1m 2More than/the g, be preferably 0.7m 2More than/the g, 1m more preferably 2More than/the g, further be preferably 1.5m 2More than/the g.Its upper limit is generally 100m 2Below/the g, be preferably 25m 2Below/the g, 15m more preferably 2Below/the g, further be preferably 10m 2Below/the g.If the value of specific area is lower than above-mentioned scope, under the situation about then using as negative pole, when charging, the acceptance variation of lithium, lithium is separated out at electrode surface easily.On the other hand, if surpass above-mentioned scope, then when using as negative material, with the reactivity increase of electrolyte, it is many that the gas of generation becomes, and is difficult to obtain preferred battery sometimes.
The BET specific area is defined as the value of following mensuration: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation, 350 ℃ to sample carry out 15 minutes predrying; Then, use nitrogen accurately to be adjusted into 0.3 nitrogen helium gas mixture body, measure through the nitrogen absorption BET1 point method that adopts the gas flow method with respect to atmospheric relative pressure value.
(6) micropore distributes
As the graphite-like carbonaceous material; Through mercury porosimeter (mercury penetration method) try to achieve be equivalent to diameter be in the particle of 0.01 μ m～1 μ m the space, since the concavo-convex amount that causes that is uneven of particle surface be generally more than the 0.01mL/g; Be preferably more than the 0.05mL/g, more preferably more than the 0.1mL/g, the upper limit is generally below the 0.6mL/g; Be preferably below the 0.4mL/g, more preferably the scope below the 0.3mL/g.If surpass this scope, need a large amount of adhesives when then manufacturing pole plate.On the other hand, if be lower than this scope, then the high current density charge-discharge characteristic reduces, and, the alleviation effects that the electrode in the time of can not obtaining discharging and recharging sometimes expands and shrinks.
In addition, total micropore volume is preferably more than the 0.1mL/g, and more preferably more than the 0.25mL/g, its upper limit is generally below the 10mL/g, is preferably below the 5mL/g, more preferably the scope below the 2mL/g.If surpass this scope, then when processing substrate, need a large amount of adhesives sometimes.If be lower than this scope, then when processing pole plate, can not obtain the dispersion effect of thickener or binding agent sometimes.
In addition, average micropore diameter is preferably more than the 0.05 μ m, more preferably more than the 0.1 μ m, further is preferably more than the 0.5 μ m, and its upper limit is generally below the 50 μ m, is preferably below the 20 μ m, more preferably the scope below the 10 μ m.If surpass this scope, then need a large amount of adhesives sometimes.On the other hand, if be lower than this scope, then the high current density charge-discharge characteristic reduces sometimes.
As the device that is used for the mercury porosimeter, can use mercury porosimeter (autopore9520; The micrometritics manufactured).The about 0.2g sample of weighing (negative material) is encapsulated into powder with in the container, carries out the degassing in 10 minutes at (below the 50 μ mHg) under room temperature, the vacuum, implements pre-treatment.Then, be decompressed to 4psia (about 28kPa), import mercury, boost to 40000psia (about 280MPa), be depressurized to 25psia (about 170kPa) then from 4psia (about 28kPa) stage shape.Number of stages when boosting is more than 80 stages, in each stage, after 10 seconds equilibration time, measures the mercury amount of being pressed into.Use the Washburn formula to be pressed into opisometer and calculate the micropore distribution from the mercury that obtains like this.In addition, the surface tension of mercury (γ) is 485dyne/cm, and contact angle (φ) is 140 °.Average micropore diameter uses the accumulation micro pore volume to reach 50% o'clock micropore diameter.
(7) circularity
Use the degree of circularity as the sphere of graphite-like carbonaceous material; The particle diameter of graphite-like carbonaceous material is that the circularity of the particle of 3～40 mu m ranges is preferably more than 0.1, is preferably especially more than 0.5, more preferably more than 0.8; Further be preferably more than 0.85, most preferably be more than 0.9.When circularity was big, the high current density charge-discharge characteristic improved, and is therefore preferred.Circularity is through the following formula definition, and circularity is 1 o'clock, becomes theoretical proper sphere.
Circularity=(having girth)/(perimeter of particle projection of shape) with particle projection of shape equivalent circular of the same area
Use the following value of measuring as the value of circularity: for example use flow-type particle picture analytical equipment (for example; The FPIA of Sysmex Industrial manufactured); About 0.2g sample is scattered in the 0.2 quality % aqueous solution (about 50mL) of polyoxyethylene (20) Span-20 as surfactant; Behind the ultrasonic wave with 1 minute 28kHz of the power output of 60W irradiation, specifying 0.6～400 μ m is detection range, and the particle of particle diameter 3～40 mu m ranges is measured.
Improve the not special restriction of method of circularity, but handle and make it to become sphere and can make when processing electrode body the shape of inter-particle voids neatly unified, so preferably through implementing spheroidization.As the example that spheroidization is handled, can enumerate, through apply shearing force, compression stress is come the mechanically method of subglobular; The adhesive force that has through adhesive or particle self is with machinery/physical treatment method of a plurality of particulate granulations etc.
(8) real density
The real density of graphite-like carbonaceous material is generally 2g/cm 3More than, be preferably 2.1g/cm 3More than, 2.2g/cm more preferably 3More than, further be preferably 2.22g/cm 3More than, be limited to 2.26g/cm on it 3Below.On be limited to the theoretical value of graphite.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.In the present invention, real density is defined as the value of measuring through the liquid phase displacement method (hydrometer method) of using butanols.
(9) tap density
The tap density of graphite-like carbonaceous material is generally 0.1g/cm 3More than, be preferably 0.5g/cm 3More than, 0.7g/cm more preferably 3More than, be preferably 0.9g/cm especially 3More than.In addition, its upper limit is preferably 2g/cm 3Below, 1.8g/cm more preferably 3Below, be preferably 1.6g/cm especially 3Below.If tap density is lower than this scope, then when using as negative pole, packed density is difficult to improve, and can not obtain the battery of high power capacity sometimes.On the other hand, if be higher than this scope, then the interparticle space in the electrode is very few, is difficult to guarantee interparticle conductivity, is difficult to obtain preferred battery behavior sometimes.
In the present invention, tap density is as giving a definition: make sample drop on 20cm through the sieve of aperture 300 μ m 3The jolt ramming container in, be full of the upper surface of container up to sample after, use powder density determination device (for example, the Tap densor that seishin enterprise-like corporation makes), carry out the vibration of 1000 length of stroke 10mm, the volume density of this moment is defined as tap density.
(10) orientation ratio (powder)
The orientation ratio of graphite-like carbonaceous material is generally more than 0.005, is preferably more than 0.01, and more preferably more than 0.015, the upper limit is the scope below 0.67 in theory.If be lower than this scope, then the high density charge-discharge characteristic reduces sometimes.
Orientation ratio is measured through X-ray diffraction.Use asymmetric Pearson VII as distribution function, (110) diffraction of the carbon that match obtains through X-ray diffraction and the peak of (004) diffraction carry out the peak and separate, and calculate the integrated intensity at the peak of (110) diffraction and (004) diffraction respectively.Calculate by the ratio that (110) diffraction integral intensity/(004) diffraction integral intensity is represented by the integrated intensity that obtains, this ratio is defined as the active material orientation ratio.
The X-ray diffraction condition determination here is following.In addition, " 2 θ " expression angle of diffraction.
The monochromatic photometer of target: Cu (K alpha ray) graphite
Slit:
Divergent slit=1 degree receives optical slits=0.1mm, scatter slit=1 degree
Measurement range and step angle/minute
(110) face: 76.5 degree≤2 θ≤78.5 degree 0.01 are spent/3 seconds
(004) face: 53.5 degree≤2 θ≤56.0 degree 0.01 are spent/3 seconds
(11) draw ratio (powder)
The draw ratio of graphite-like carbonaceous material is that the upper limit is generally below 10 more than 1 in theory, is preferably below 8, more preferably below 5.If surpass its upper limit, striped can be produced when processing pole plate, uniform coated face can't be obtained, the high current density charge-discharge characteristic reduces sometimes.
The ratio A/B of the major diameter A of material with carbon element particle and perpendicular minor axis B represented when in addition, draw ratio was with three dimensional viewing.The observation of carbon particle is carried out through the scanning electron microscope that can amplify observation.Selection is fixed on any 50 graphite particles on the end face of the metal below the thickness 50 μ m, rotation, tilts to be fixed with the objective table of sample, measures A, the B of these particles respectively, obtains the mean value of A/B.
[[[[low-crystalline carbonaceous material]]]]
The low-crystalline carbonaceous material is meant that the interplanar distance (d002) of (002) face of measuring through X ray wide-angle diffraction method is the above low carbonaceous material of crystallinity of 0.340nm.
(composition of low-crystalline carbonaceous material)
" with the different carbonaceous material of particle shape carbonaceous material crystallization " preferably low low-crystalline carbonaceous material than the crystallinity of particle shape carbonaceous material.In addition, preferred especially following (d) or carbide (e).
(d) but be selected from coal class heavy oil, straight run class heavy oil, decompose the organic substance of the carbonization in a type black petroleum products, aromatic hydrocarbon, N cycle compound, S cycle compound, polyphenyl, organic synthesis macromolecule, natural polymer, thermoplastic resin and the heat reactive resin;
(e) but the organic substance of these carbonizations is dissolved in the small molecular organic solvent and the solution that obtains.
As coal class heavy oil, preferably coal tar asphalt from the maltha to the pitch or dry distillation liquid carburetion etc.; As straight run class heavy oil, preferred atmospheric resids, decompression residual oil etc.; As decomposing a type black petroleum products, the ethylene bottom oil of by-product etc. during thermal decompositions such as preferred crude oil, naphtha; As aromatic hydrocarbon, preferred acenaphthylene, decacyclene, anthracene, phenanthrene etc.; As the N cycle compound, preferred azophenlyene, acridine etc.; As the S cycle compound, preferred thiophene, di-thiophene etc.; As polyphenyl, preferred biphenyl, terphenyl etc.; As organic polymer, preferred polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral resin, they do not dissolve handled thing, polyacrylonitrile, polypyrrole, polythiophene, polystyrene etc.; As natural polymer, polysaccharides such as preferred cellulose, lignin, mannosan, polygalacturonic acid, shitosan, sucrose etc.; As thermoplastic resin, preferred polyphenylene sulfide, polyphenylene oxide etc.; As thermosetting resin, preferred furfuryl alcohol resin, phenolic resins, imide resin etc.
The carbide of " with the different carbonaceous material of particle shape carbonaceous material crystallinity " preferably above-mentioned " but organic substance of carbonization "; In addition, also preferably these " but organic substances of carbonization " are dissolved in the small molecular organic solvents such as benzene,toluene,xylene, quinoline, n-hexane and obtain the carbide of solution etc.In addition, the carbide of " with the different carbonaceous material of particle shape carbonaceous material crystallinity " preferred coal class coke, petroleum-type coke.
As above-mentioned (d) or (e), preferred especially liquid.That is,, preferably in liquid phase, carry out carbonization from partly generating the viewpoint at interface with the graphite-like carbonaceous material.
(rerum natura of low-crystalline carbonaceous material)
Show under preferably satisfying simultaneously as the rerum natura of low-crystalline carbonaceous material in (1)～(5) any one or multinomial.In addition, can use a kind of low-crystalline carbonaceous material that shows these rerum naturas separately, also can use more than 2 kinds with combination in any and ratio combination.
(1) X ray parameter
For low-crystalline carbonaceous material part, the d value (interfloor distance) through adopt learning the lattice plane (002 face) that X-ray diffraction that the method for shaking carries out tries to achieve is preferably more than the 0.340nm from defining to more than the 0.340nm, is preferably more than the 0.341nm especially.In addition, be limited on it below 0.380nm, be preferably especially below the 0.355nm, further be preferably below 0.350.If the d value is excessive, then form obviously low surface of crystallinity, increase irreversible capacity sometimes, and if d value is too small, then the low-crystalline carbonaceous material is set and the effect of the charging acceptance raising that obtains diminishes, thereby effect of the present invention diminishes on the surface.In addition, the crystallite size (Lc) of the material with carbon element of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is generally more than the 1nm, is preferably the above scope of 1.5nm.If be lower than this scope, then crystallinity reduces, and increases the increase of initial stage irreversible capacity sometimes.
(2) ash content
The contained ash content of low-crystalline carbonaceous material part is preferably below the 1 quality % with respect to the gross mass of composite carbonaceous material, more preferably below the 0.5 quality %, is preferably especially below the 0.1 quality %, as lower limit, is preferably more than the 1ppm.If surpass above-mentioned scope, can not ignore with the reaction of electrolyte and the deterioration of the battery performance that causes when then discharging and recharging.And if be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
(3) Raman R value, Raman half breadth
The low-crystalline carbonaceous material R value partly of using the argon laser Raman spectroscopy to measure is generally more than 0.5, is preferably more than 0.7, and more preferably more than 0.9, its upper limit is generally below 1.5, is preferably the scope below 1.2.If the R value is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.In addition, be coated on the collector body after, when making the negative pole densification through compacting, crystallization is oriented to the direction parallel with battery lead plate easily, causes part throttle characteristics to reduce sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of electrolyte, causes the gas of efficient reduction or generation to increase sometimes.
In addition, low-crystalline carbonaceous material part is at 1580cm -1Near Raman half breadth has no particular limits, and is generally 40cm -1More than, be preferably 50cm -1More than, its upper limit is generally 100cm -1Below, be preferably 90cm -1Below, 80cm more preferably -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.In addition, be coated on the collector body after, when making the negative pole densification through compacting, crystallization is oriented to the direction parallel with battery lead plate easily, causes part throttle characteristics to reduce sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of electrolyte, causes the gas of efficient reduction or generation to increase sometimes.
(4) real density
The real density of low-crystalline carbonaceous material part is generally 1.4g/cm 3More than, be preferably 1.5g/cm 3More than, 1.6g/cm more preferably 3More than, further be preferably 1.7g/cm 3More than, its upper limit is generally 2.1g/cm 3Below, be preferably 2g/cm 3Below.If surpass this scope, the acceptance of then charging maybe be impaired.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.
(5) orientation ratio (powder)
The orientation ratio of low-crystalline carbonaceous material part is generally more than 0.005, is preferably more than 0.01, more preferably more than 0.015, is limited to theoretical value on it below 0.67.If be lower than this scope, then the high density charge-discharge characteristic reduces sometimes, and is not preferred.Orientation ratio is measured through X-ray diffraction.Use asymmetric Pearson VII as distribution function, (110) diffraction that match carbon obtains through X-ray diffraction and the peak of (004) diffraction carry out the peak and separate, and calculate the integrated intensity at the peak of (110) diffraction and (004) diffraction respectively.Calculate by the ratio that (110) diffraction integral intensity/(004) diffraction integral intensity is represented by the integrated intensity that obtains, this ratio is defined as the active material orientation ratio.
[[[composite carbonaceous material]]]
The composite carbonaceous material that uses in the negative pole in the lithium secondary battery of the present invention [1] preferably contains " particle shape carbonaceous material " and " with the different carbonaceous material of this particle shape carbonaceous material crystallinity "; At this moment; As long as wherein any one is the graphite-like carbonaceous material, and another gets final product for the low-crystalline carbonaceous material.In addition, preferred " particle shape carbonaceous material " is the graphite-like carbonaceous material, and " with the different carbonaceous material of this particle shape carbonaceous material crystallinity " is the low-crystalline carbonaceous material.
In composite carbonaceous material, the mass ratio of graphite-like carbonaceous material and low-crystalline carbonaceous material is preferably more than 50/50, more preferably more than 80/20; Be preferably more than 90/10 especially; And be preferably below the 99.9/0.1, more preferably below 99/1, be preferably the scope below 98/2 especially.If surpass above-mentioned scope, then can not obtain having the effect of 2 kinds of crystalline carbonaceous material sometimes, if be lower than above-mentioned scope, the initial stage irreversible capacity shows the tendency of increase, on battery design, has problems sometimes.The graphite-like carbonaceous material is more than the 50 quality % with respect to whole composite carbonaceous materials.
(rerum natura of composite carbonaceous material)
As composite carbonaceous material, preferred satisfy simultaneously below shown in (1)～(11) in any one or multinomial.In addition, can use a kind of composite carbonaceous material that shows these rerum naturas separately, also can use more than 2 kinds with combination in any and ratio combination.
(1) X ray parameter
Composite carbonaceous material is preferably more than the 0.335nm through the d value (interfloor distance) of the lattice plane (002) that X-ray diffraction that adopt to learn the method for shaking is tried to achieve, and is generally below the 0.350nm, is preferably below the 0.345nm, more preferably below the 0.340nm.In addition, the crystallite size (Lc) of the material with carbon element of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is generally more than the 1.5nm, is preferably the above scope of 3.0nm.If be lower than this scope, then crystallinity reduces, and might increase the increase of initial stage irreversible capacity.
(2) ash content
The contained ash content of composite carbonaceous material is preferably below the 1 quality % with respect to the gross mass of composite carbonaceous material, more preferably below the 0.5 quality %, is preferably especially below the 0.1 quality %, as its lower limit, is preferably more than the 1ppm.If surpass above-mentioned scope, can not ignore with the reaction of electrolyte and the deterioration of the battery performance that causes when then discharging and recharging.If be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
(3) volume reference average grain diameter
The volume reference average grain diameter of composite carbonaceous material is the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method, is generally more than the 1 μ m, is preferably more than the 3 μ m, more preferably more than the 5 μ m, further is preferably more than the 7 μ m.In addition, its upper limit is generally below the 100 μ m, is preferably below the 50 μ m, more preferably below the 40 μ m, further is preferably below the 30 μ m, is preferably especially below the 25 μ m.If be lower than above-mentioned scope, then irreversible capacity increases, and causes the loss of initial stage battery capacity sometimes.In addition, if surpass above-mentioned scope, then when processing electrode pad, forming uneven coated face easily, is not preferred sometimes on the battery production process.
(4) Raman R value, Raman half value are wide
Use the R value of the composite carbonaceous material of argon laser Raman spectroscopy mensuration to be generally more than 0.03, be preferably more than 0.10, more preferably more than 0.15, its upper limit is generally below 0.60, is preferably the scope below 0.50.If the R value is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.In addition, be coated on the collector body after, when making the negative pole densification through compacting, crystallization is oriented to the direction parallel with battery lead plate easily, causes part throttle characteristics to reduce sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of electrolyte, causes the gas of efficient reduction or generation to increase sometimes.
In addition, composite carbonaceous material is at 1580cm -1Near Raman half breadth has no particular limits, and is generally 15cm -1More than, be preferably 20cm -1More than, its upper limit is generally 70cm -1Below, be preferably 60cm -1Below, 50cm more preferably -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.In addition, be coated on the collector body after, when making the negative pole densification through compacting, crystallization is oriented to the direction parallel with battery lead plate easily, causes part throttle characteristics to reduce sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of electrolyte, causes the gas of efficient reduction or generation to increase sometimes.
(5) BET specific area
Use the specific area of the composite carbonaceous material of the present invention of BET method mensuration to be generally 0.1m 2More than/the g, be preferably 0.7m 2More than/the g, 1m more preferably 2More than/the g, further be preferably 1.5m 2More than/the g.Its upper limit is generally 100m 2Below/the g, be preferably 25m 2Below/the g, 15m more preferably 2Below/the g, further be preferably 10m 2Below/the g.If the value of specific area is lower than above-mentioned scope, then under situation about using as negative material, the acceptance variation of lithium during charging, lithium is separated out at electrode surface easily.On the other hand, if surpass above-mentioned scope, when then using as negative material, with the reactivity increase of electrolyte, it is many that the gas of generation becomes, and is difficult to obtain preferred battery sometimes.
(6) micropore distributes
As the complex class carbonaceous material; Space in the particle that is equivalent to diameter 0.01 μ m～1 μ m of trying to achieve through mercury porosimeter (mercury penetration method), since the concavo-convex amount that causes that is uneven of particle surface be generally more than the 0.01mL/g; Be preferably more than the 0.05mL/g, more preferably more than the 0.1mL/g, its upper limit is generally below the 0.6mL/g; Be preferably below the 0.4mL/g, more preferably the scope below the 0.3mL/g.If surpass this scope, need a large amount of adhesives when then processing pole plate.If be lower than this scope, then the high current density charge-discharge characteristic reduces, and, the alleviation effects that the electrode in the time of can not obtaining discharging and recharging sometimes expands and shrinks.
In addition, total micropore volume is preferably more than the 0.1mL/g, and more preferably more than the 0.25mL/g, its upper limit is generally below the 10mL/g, is preferably below the 5mL/g, more preferably the scope below the 2mL/g.If surpass this scope, then need a large amount of adhesives sometimes.And if be lower than this scope, then when processing pole plate, can not obtain the dispersion effect of thickener or binding agent sometimes.
In addition, average micropore diameter is preferably more than the 0.05 μ m, more preferably more than the 0.1 μ m, further is preferably more than the 0.5 μ m, and its upper limit is generally below the 80 μ m, is preferably below the 50 μ m, more preferably the scope below the 20 μ m.If surpass this scope, then need a large amount of adhesives sometimes.And if be lower than this scope, then the high current density charge-discharge characteristic reduces sometimes.
(7) circularity
Use the degree of circularity as the sphere of composite carbonaceous material, the particle diameter of composite carbonaceous material is that the circularity of the particle of 3～40 mu m ranges is preferably more than 0.85, more preferably more than 0.87, further is preferably more than 0.9.When circularity was big, the high current density charge-discharge characteristic improved, and is therefore preferred.
(8) real density
The real density of composite carbonaceous material is generally 1.9g/cm 3More than, be preferably 2g/cm 3More than, 2.1g/cm more preferably 3More than, further be preferably 2.2g/cm 3More than, be limited to 2.26g/cm on it 3Below.On be limited to the theoretical value of graphite.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.
(9) tap density
The tap density of composite carbonaceous material is generally 0.1g/cm 3More than, be preferably 0.5g/cm 3More than, 0.7g/cm more preferably 3More than, be preferably 1g/cm especially 3More than.In addition, its upper limit is preferably 2g/cm 3Below, 1.8g/cm more preferably 3Below, be preferably 1.6g/cm especially 3Below.If tap density is lower than this scope, then when using as negative pole, packed density is difficult to improve, and can not obtain the battery of high power capacity sometimes.On the other hand, if surpass this scope, then the interparticle space in the electrode is very few, is difficult to guarantee interparticle conductivity, is difficult to obtain preferred battery behavior sometimes.Tap density is measured through the method identical with said method, and according to this method definition.
(10) orientation ratio (powder)
The orientation ratio of composite carbonaceous material is generally more than 0.005, is preferably more than 0.01, and more preferably more than 0.015, its upper limit is the scope below 0.67 in theory.If be lower than this scope, then the high density charge-discharge characteristic reduces sometimes.
(11) draw ratio (powder)
The draw ratio of composite carbonaceous material is that its upper limit is generally below 10 more than 1 in theory, is preferably below 8, more preferably below 5.If surpass its upper limit, produce striped when processing pole plate sometimes, can't obtain uniform coated face, the high current density charge-discharge characteristic reduces.
(manufacturing approach of composite carbonaceous material)
The manufacturing approach of these composite carbonaceous materials has no particular limits, and can enumerate the method shown in following.
Compoundization of graphite-like carbonaceous material and low-crystalline carbonaceous material can adopt following method: the carbon precursor that directly is used to obtain the low-crystalline carbonaceous material; The mixture of heat treated carbon precursor and graphite-like carbonaceous material powder obtains the method for composite powder; Above-mentioned carbon precursor is carried out partially carbonized, prepare low-crystalline carbonaceous material powder in advance, with graphite-like carbonaceous material powder, heat treated is to carry out the method for compoundization again; Make above-mentioned low-crystalline carbonaceous material powder in advance, admixed graphite class carbonaceous material powder, low-crystalline carbonaceous material powder and carbon precursor, the method for compoundization etc. is carried out in heating.In addition, in the back two kinds methods of preparing low-crystalline carbonaceous material powder in advance, preferably use the low-crystalline carbonaceous material particle 1/10th below of average grain diameter as the average grain diameter of graphite-like carbonaceous material.In addition, can also adopt following method:, process a kind of material and be mingled with the structure in another material, perhaps the method for the structure of electrostatic adherence through the low-crystalline carbonaceous material and the graphite-like carbonaceous material of making in advance applied mechanics energy such as pulverizing.
Preferably, the mixture that has mixed graphite-like carbonaceous material particle and carbon precursor is heated, obtain intermediate material; Perhaps, the mixture of graphite-like carbonaceous material particle and low-crystalline carbonaceous material particle is mixed with the carbon precursor and the mixture that obtains heats, obtain intermediate material; Then; Carburizing sintering is pulverized, and finally obtains the composite carbonaceous material that in the graphite-like material particle compoundization has the low-crystalline carbonaceous material thus.
The manufacturing process that is used to obtain composite carbonaceous material is divided into following 4 operations.
The 1st operation: use various commercially available mixers or mixing roll with the carbon precursor of (graphite-like carbonaceous material particle or (stuff and other stuff of graphite-like carbonaceous material particle and low-crystalline carbonaceous material particle)) and low-crystalline carbonaceous material particle and the solvent of adding as required, obtain mixture.
The 2nd operation: add hot mixt, be removed solvent and the intermediate material of the volatile ingredient that produces by the carbon precursor.At this moment, as required, can carry out on stirring said mixture limit, limit.In addition, even residual have volatile ingredient, owing to can in the 3rd follow-up operation, remove, so also out of question.
The 3rd operation: under non-active gas atmosphere such as nitrogen, carbon dioxide, argon gas, said mixture or intermediate material are heated to 400 ℃～3200 ℃, obtain graphite low-crystalline carbonaceous material compound substance.
The 4th operation: as required to above-mentioned compound substance pulverize, powder processing such as fragmentation, hierarchical processing.
In these operations, according to circumstances can omit the 2nd operation and the 4th operation, the 4th operation also can be carried out before the 3rd operation.But, when implementing the 4th operation before the 3rd operation, as required, pulverize once more, powder such as fragmentation, classification process, and obtain composite carbonaceous material.
In addition, as the heat treated condition of the 3rd operation, the thermal history temperature conditions is important.The lower limit of this temperature is according to the kind of carbon precursor, this thermal history and different, but is generally more than 400 ℃, is preferably more than 900 ℃.On the other hand, ceiling temperature can reach the temperature of the structure order that does not have the crystalline texture that surmounts graphite-like carbonaceous material particle core basically.Therefore,, be generally below 3200 ℃, be preferably below 2000 ℃, more preferably below 1500 ℃ as heat treated ceiling temperature.Under such heat-treat condition, can set programming rate, cooling rate, heat treatment time etc. arbitrarily according to purpose.In addition, can also, lower temperature province be warmed up to the temperature of regulation after heat-treating.In addition, the reactor that uses in this operation can be a batch (-type), also can be continous way, in addition, can be one and also can be many.
[[auxiliary material mixing]]
Except that above-mentioned composite carbonaceous material; In the negative electrode active material of lithium secondary battery of the present invention, contain more than one with above-mentioned composite carbonaceous material in carbonaceous material (carbonaceous material) different aspect the rerum natura of carbonaceous, can further seek the raising of battery performance thus.Here said " rerum natura of carbonaceous " is meant the more than one characteristic of X-ray diffraction parameter, median particle diameter, draw ratio, BET specific area, orientation ratio, Raman R value, tap density, real density, micropore distribution, circularity, ash amount.In addition,, can enumerate as preferred embodiment, asymmetric about when the volume reference particle size distribution is the center with the median particle diameter, to contain Raman R value is different more than 2 kinds carbonaceous material or X ray parameter not equal.As an example of its effect, can enumerate through containing graphite such as native graphite, Delanium; Carbon blacks such as acetylene black; Material with carbon elements such as amorphous carbon such as needle coke reduce resistance etc. as auxiliary material.They can use a kind of separately, also can use more than 2 kinds with combination in any and arbitrary proportion combination.When adding as auxiliary material, its addition is more than the 0.1 quality %, is preferably more than the 0.5 quality %; More preferably more than the 0.6 quality %, be limited on it below 80 quality %, be preferably below the 50 quality %; More preferably below the 40 quality %, further be preferably the scope below the 30 quality %.If be lower than this scope, then be difficult to obtain the effect that conductivity improves sometimes.If surpass above-mentioned scope, then cause the increase of initial stage irreversible capacity sometimes.
[making negative pole [1] electrode]
Make negative pole [1] and can adopt usual way, can with the above-mentioned negative pole [1] that likewise forms.The thickness ratio of collector body, collector body and active material layer, electrode density, adhesive, pole plate orientation ratio, impedance etc. are also same as described above.
< negative pole [2] >
Below; Negative pole [2] to using in the lithium secondary battery of the present invention describes; This negative pole contains amorphous carbonaceous as active material; It is more than the 0.337nm that said amorphous carbonaceous adopts the interplanar distance (d002) of (002) face that wide-angle x-ray diffraction measures, and crystallite size (Lc) is below the 80nm, in the argon laser Raman spectroscopy with 1360cm -1Peak intensity with respect to 1580cm -1The Raman R value of ratio value defined of peak intensity be more than 0.2.
[negative electrode active material of negative pole [2]]
Below, the negative electrode active material that uses in the anticathode [2] describes.
The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [2] is to contain at least to satisfy following (a) and (b) and amorphous carbonaceous (c).
(a) adopting the interplanar distance (d002) of (002) face of wide-angle x-ray diffraction mensuration is more than the 0.337nm;
(b) adopting the crystallite size Lc of (002) face of wide-angle x-ray diffraction mensuration is below the 80nm;
(c) in the argon laser Raman spectroscopy with 1360cm -1Peak intensity with respect to 1580cm -1The Raman R value (below, abbreviate " Raman R value " sometimes as) of ratio value defined of peak intensity be more than 0.2.
The negative electrode active material that uses among the present invention contains at least and satisfies (a) and (b) and (c) amorphous carbonaceous; The content of these amorphous carbonaceous in total negative electrode active material is preferably more than the 10 quality %; More preferably more than the 50 quality %; Be preferably 100 quality % especially, just all active materials all are amorphous carbonaceous.As making up the negative electrode active material that uses with amorphous carbonaceous, there is not special qualification, can use known negative electrode active material, for example, Delanium, native graphite etc.
[[interplanar distance (d002), Lc]]
The interplanar distance (d002) of (002) face that the amorphous carbonaceous of using as the negative electrode active material of negative pole [2] in the lithium secondary battery of the present invention is measured through wide-angle x-ray diffraction is preferably more than the 0.34nm as more than the 0.337nm.Its upper limit is generally below the 0.39nm, is preferably below the 0.38nm, more preferably below the 0.37nm, further is preferably below the 0.36nm, is preferably below the 0.35nm especially.If surpass this scope, then crystallinity significantly reduces, and the reduction of interparticle conductivity can not be ignored, and is difficult to obtain the raising effect of short time high current density charge-discharge characteristic sometimes.On the other hand, if be lower than this scope, then crystallinity becomes too high, is difficult to obtain the raising effect of short time high current density charge-discharge characteristic sometimes.
The interplanar distance (d002) of (002) face that the said employing wide-angle x-ray of the present invention method is measured is meant through adopting the d value (interfloor distance) of lattice plane (002) face that the X-ray diffraction of learning the method for shaking tries to achieve.
The crystallite size (Lc) of (002) face through adopt learning the amorphous carbonaceous that X-ray diffraction that the method for shaking measures tries to achieve is preferably below the 35nm for below the 80nm, more preferably below the 20nm, further is preferably below the 10nm.Its lower limit is generally more than the 0.1nm, is preferably more than the 1nm.If be lower than this scope, then crystallinity significantly reduces, and the reduction of conductivity can not be ignored between particle sometimes, and, be difficult to obtain the raising effect that the short time high current density discharges and recharges sometimes.On the other hand, if surpass this scope, then crystallinity becomes too high, is difficult to obtain the raising effect that the short time high current density discharges and recharges sometimes.
[[Raman R value]]
The Raman R value of the amorphous carbonaceous of using as the negative electrode active material of negative pole [2] in the lithium secondary battery of the present invention is necessary for more than 0.2, is preferably more than 0.5, is preferably especially more than 0.7, more preferably more than 0.8.Its upper limit is generally below 1.5, more preferably below 1.2.If Raman R value is lower than this scope, then the crystallinity of particle surface is too high, and the charging acceptance reduces, and therefore, is difficult to obtain the raising effect of short time high current density charge-discharge characteristic sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface significantly descends, and therefore, it is big that interparticle contact resistance becomes, and is difficult to obtain the raising effect that the short time high current density discharges and recharges sometimes.
The mensuration of Raman spectrum is carried out as follows: (for example use the raman spectroscopy device; The raman spectroscopy device of Japan's beam split manufactured); Sample is dropped into naturally measure in the container, carry out sample and fill, the mensuration process is; To the specimen surface in container irradiation argon laser, make simultaneously this container with the face of laser vertical in rotate.For the Raman spectrum that obtains, measure 1580cm -1Peak P AIntensity I AAnd 1360cm -1Peak P BIntensity I B, calculate its strength ratio R (R=I B/ I A), it is defined as the Raman R value of amorphous carbonaceous.In addition, measure the Raman spectrum obtain at 1580cm -1Peak P AHalf breadth, it is defined as the Raman half breadth of amorphous carbonaceous.
In addition, the Raman condition determination here is following.
Argon laser wavelength: 514.5nm
Laser power on the sample: 15～25mW
Resolution: 10～20cm -1
Measurement range: 1100cm -1～1730cm -1
Raman R value, Raman half breadth are analyzed: background is handled
Smooth treatment: simple average, convolution 5 points
In addition, the amorphous carbonaceous of using as the negative electrode active material of negative pole [2] in the lithium secondary battery of the present invention is at 1580cm -1The Raman half breadth have no particular limits, be generally 20cm -1More than, be preferably 25cm -1More than, in addition, its upper limit is generally 150cm -1Below, be preferably 140cm -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface becomes too high, and the charging acceptance reduces, and therefore, is difficult to obtain the raising effect that the short time high current density discharges and recharges sometimes.On the other hand, if surpass above-mentioned scope, then the crystallinity of particle surface significantly reduces, and therefore, it is big that interparticle contact resistance becomes, and might be difficult to obtain the raising effect that the short time high current density discharges and recharges.But the Raman half breadth can not be judged through peak shape sometimes.
The amorphous carbonaceous that the present invention uses satisfies the condition of above-mentioned interplanar distance (d002), crystallite size (Lc) and Raman R value, but from the balance this point of battery, more preferably satisfies any one or multinomial condition in the following project simultaneously.Among these, especially preferably satisfy any one or multinomial condition in micropore volume, ash content and the volume average particle size of real density, H/C value, O/C value, tap density, BET specific area, 0.01 μ m～1 mu m range simultaneously.
[[real density]]
The real density of amorphous carbonaceous is generally 2.22g/cm 3Below, be preferably 2.2g/cm 3Below, 2.1g/cm more preferably 3Below, further be preferably 2.0g/cm 3Below, its lower limit is generally 1.4g/cm 3More than, be preferably 1.5g/cm 3More than, 1.6g/cm more preferably 3More than, further be preferably 1.7g/cm 3More than, be preferably 1.8g/cm especially 3Above scope.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.If surpass this scope, then the crystallinity of carbon is too high, is difficult to obtain the raising effect that the short time high current density discharges and recharges.
In the present invention, real density is defined as the value of measuring through the liquid phase displacement method (hydrometer method) of using butanols.
[[O/C value]]
The upper limit that the atom of amorphous carbonaceous is made a gesture of measuring the O/C value is generally below 0.15, is preferably below 0.1, more preferably below 0.05, further is preferably below 0.03, and its lower limit is generally more than 0, is preferably more than 0.01.
The ratio of the molar concentration of the oxygen atom that exists in the O/C value representation amorphous carbonaceous and the molar concentration of carbon atom is the index of the amount of functional groups such as expression carboxyl, phenol property hydroxyl, carbonyl.The big amorphous carbonaceous of O/C value is combined with oxygen-containing functional group at end face of carbon crystallite etc. mostly.If the O/C value surpasses above-mentioned scope, then irreversible capacity increases sometimes.
[[H/C value]]
The upper limit that the atom of amorphous carbonaceous is made a gesture of measuring the H/C value is generally below 0.3, is preferably below 0.15, more preferably below 0.1, further is preferably below 0.08, and its lower limit is generally more than 0, is preferably more than 0.01.
So-called H/C value, the ratio of the molar concentration of the hydrogen atom that exists in the expression amorphous carbonaceous and the molar concentration of carbon atom is an index of representing to be present in the amount of the hydrogen on the crystallite end face of amorphous carbonaceous.The amorphous carbon material that the H/C value is big is represented the amount of the crystallite end face etc. of particle face carbon more than carbon mostly.If the H/C value surpasses above-mentioned scope, then irreversible capacity increases sometimes.
Said among the present invention " O/C value " and " H/C value " are obtained through the CHN elementary analysis shown in following.
[[CHN elementary analysis]]
With amorphous carbonaceous to be determined about 15 hours of 120 ℃ of following drying under reduced pressure, be placed on then on the hot plate in the drying box in 100 ℃ dry 1 hour down.Then; In argon atmosphere, sample is placed the aluminium cup, the weight of the carbon dioxide that produces through burning is obtained carbon content; In addition; Weight through the water that produces is obtained hydrogen content, calculates nitrogen content through the weight of the nitrogen dioxide that produces, obtains inorganic content by the weight of the residual residue in burning back.The value of oxygen content draws through from total weight, deducting carbon content, hydrogen content, nitrogen content, inorganic content.Calculate molal quantity by these values, adopt each content molal quantity that obtains to obtain O/C value, H/C value through following formula.
O/C value=contain oxygen molal quantity/carbon containing molal quantity
H/C value=hydrogeneous molal quantity/carbon containing molal quantity
[[tap density]]
The tap density of the amorphous carbonaceous of using as the active material of negative pole [2] in the lithium secondary battery of the present invention is preferably 0.1g/cm 3More than, 0.2g/cm more preferably 3More than, further be preferably 0.5g/cm 3More than, be preferably 0.7g/cm especially 3More than.In addition, its upper limit is preferably 1.4g/cm 3Below, 1.2g/cm more preferably 3Below, be preferably 1.1g/cm especially 3Below.If tap density is lower than this scope, be difficult to improve packed density when then using as negative pole, interparticle contact area reduces, and therefore interparticle impedance increases, and reduces short time high current density charge-discharge characteristic sometimes.On the other hand, if surpass this scope, then the interparticle space in the electrode is very few, and the stream of nonaqueous electrolytic solution can reduce, and therefore reduces short time high current density charge-discharge characteristic sometimes.
In the present invention, tap density is as giving a definition: make sample pass through the sieve of aperture 300 μ m, make sample fall into 20cm 3The jolt ramming container in; Be full of the upper surface of container to sample after, use powder density determination device (for example, the Tap densor of seishin enterprise-like corporation manufacturing); Carry out the vibration of 1000 length of stroke 10mm, the density that the volume with thus time the and the weight of sample are obtained is as tap density.
[[BET specific area]]
The specific area that the amorphous carbonaceous of using as the negative electrode active material of negative pole [2] in the lithium secondary battery of the present invention is measured through the BET method is preferably 0.1m 2More than/the g, be preferably 0.5m especially 2More than/the g, 0.7m more preferably 2More than/the g, further be preferably 1.5m 2More than/the g.Its upper limit is preferably 100m 2Below/the g, be preferably 50m especially 2Below/the g, 25m more preferably 2Below/the g, further be preferably 15m 2Below/the g.If the value of BET specific area is lower than this scope, then under situation about using as negative material, the easy variation of acceptance of lithium when charging, lithium can be separated out at electrode surface sometimes.On the other hand, if the value of BET specific area surpasses this scope, when using as negative material, with the reactivity increase of nonaqueous electrolytic solution, it is many that the gas of generation becomes, and can not get preferred battery sometimes.
The BET specific area is defined as following value: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation, 350 ℃ to sample carry out 15 minutes predrying; Then, use nitrogen accurately to be adjusted into 0.3 nitrogen helium gas mixture body, adsorb the value that BET1 point method is measured through the nitrogen that adopts the gas flow method with respect to atmospheric relative pressure value.
[[volume average particle size]]
The volume average particle size of the amorphous carbonaceous of using as the negative electrode active material of negative pole [2] in the lithium secondary battery of the present invention is defined as the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method; Be generally more than the 1 μ m; Be preferably more than the 3 μ m; More preferably more than the 5 μ m, further be preferably more than the 7 μ m.In addition, its upper limit is generally below the 50 μ m, is preferably below the 40 μ m, more preferably below the 30 μ m, further is preferably below the 25 μ m.If be lower than above-mentioned scope, then irreversible capacity increases, and causes the loss of initial stage battery capacity sometimes.In addition, if surpass above-mentioned scope, when then processing the pole plate of electrode, forming uneven coated face easily, is not preferred sometimes on the battery production process.
[[micropore volume]]
The micropore volume of the amorphous carbonaceous of using as the negative electrode active material of negative pole [2] in the lithium secondary battery of the present invention; Space in the particle that is equivalent to diameter 0.01 μ m～1 μ m of trying to achieve through mercury porosimeter (mercury penetration method), because the concavo-convex amount that causes that is uneven of particle surface is more than the 0.01mL/g; Be preferably more than the 0.05mL/g; More preferably more than the 0.1mL/g; Its upper limit is generally below the 0.6mL/g, is preferably below the 0.4mL/g, more preferably the scope below the 0.3mL/g.If surpass this scope, need a large amount of adhesives when then manufacturing pole plate.And if be lower than this scope, then short time high current density charge-discharge characteristic reduces, and, the alleviation effects that the electrode in the time of can not obtaining discharging and recharging sometimes expands and shrinks.
In addition, more than total preferred 0.1mL/g of micropore volume, more preferably more than the 0.25mL/g, its upper limit is generally below the 10mL/g, is preferably below the 5mL/g, more preferably the scope below the 2mL/g.If surpass this scope, then need a large amount of adhesives sometimes.If be lower than this scope, then when processing pole plate, can not obtain the dispersion effect of thickener or binding agent sometimes.
In addition, average micropore diameter is preferably more than the 0.05 μ m, more preferably more than the 0.1 μ m, further is preferably more than the 0.5 μ m, and its upper limit is generally below the 50 μ m, is preferably below the 20 μ m, more preferably the scope below the 10 μ m.If surpass this scope, then need a large amount of adhesives sometimes.On the other hand, if be lower than this scope, then short time high current density charge-discharge characteristic reduces sometimes.
As the device that is used for the mercury porosimeter, can use mercury porosimeter (autopore9520; The micrometritics manufactured).The about 0.2g sample of weighing (negative material) is encapsulated into powder with in the container, carries out the degassing in 10 minutes at (below the 50 μ mHg) under room temperature, the vacuum, implements pre-treatment.Then, be decompressed to 4psia (about 28kPa), import mercury, boost to 40000psia (about 280MPa) from 4psia (about 28kPa) stage shape after, be depressurized to 25psia (about 170kPa) again.Number of stages when boosting is more than 80 stages, in each stage, after 10 seconds equilibration time, measures the mercury amount of being pressed into.Using the Washburn formula to be pressed into the curve calculation micropore from the mercury that obtains like this distributes.In addition, the surface tension of mercury (γ) is 485dyne/cm, and contact angle (φ) is 140 °.Average micropore diameter uses the accumulation micro pore volume to reach 50% o'clock micropore diameter.
[[ash content]]
Contained ash content is preferably below the 1 quality % with respect to the gross mass of carbonaceous material in the carbonaceous material, more preferably below the 0.5 quality %, is preferably especially below the 0.1 quality %, in addition, as lower limit, in mass, is preferably more than the 1ppm.If surpass above-mentioned scope, the deterioration of the battery performance that causes owing to the reaction with nonaqueous electrolytic solution when then discharging and recharging can not be ignored.On the other hand, if be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
[[circularity]]
The circularity of the amorphous carbonaceous of using as the negative electrode active material of negative pole [2] in the lithium secondary battery of the present invention is generally more than 0.1, is preferably more than 0.8, more preferably more than 0.85, further is preferably more than 0.9.As the upper limit, circularity is to reach theoretic proper sphere at 1 o'clock.If be lower than this scope, then the fillibility of negative electrode active material reduces, and interparticle impedance increases, and short time high current density charge-discharge characteristic reduces sometimes.
Circularity of the present invention defines with following formula.
Circularity=(having girth)/(perimeter of particle projection of shape) with particle projection of shape equivalent circular of the same area
Use following value as the value of circularity: for example use flow-type particle picture analytical equipment (for example; The FPIA of Sysmex Industrial manufactured); About 0.2g sample is scattered in the 0.2 quality % aqueous solution (about 50mL) of polyoxyethylene (20) Span-20 as surfactant; Behind the ultrasonic wave with 1 minute 28kHz of the power output of 60W irradiation; Specifying 0.6～400 μ m is detection range, the particle of particle diameter 3～40 mu m ranges is measured, and used the mean value of its mensuration.
[[orientation ratio]]
The orientation ratio of the amorphous carbonaceous of using as the negative electrode active material of negative pole [2] in the lithium secondary battery of the present invention is generally more than 0.005, is preferably more than 0.01, and more preferably more than 0.015, its upper limit is below 0.67 in theory.If be lower than this scope, then short time high density charge-discharge characteristic reduces sometimes.
Orientation ratio is measured through X-ray diffraction.Use asymmetric Pearson VII as distribution function, (110) diffraction of the carbon that match obtains through X-ray diffraction and the peak of (004) diffraction carry out the peak and separate, and calculate the integrated intensity at the peak of (110) diffraction and (004) diffraction respectively.By the integrated intensity that obtains, calculate by the ratio that (110) diffraction integral intensity/(004) diffraction integral intensity is represented, this ratio is defined as the active material orientation ratio.
The X-ray diffraction condition determination here is following.In addition, " 2 θ " expression angle of diffraction.
The monochromatic photometer of target: Cu (K alpha ray) graphite
Slit:
Divergent slit=1 degree receives optical slits=0.1mm, scatter slit=1 degree
Measurement range and step angle/minute
(110) face: 76.5 degree≤2 θ≤78.5 degree 0.01 are spent/3 seconds
(004) face: 53.5 degree≤2 θ≤56.0 degree 0.01 are spent/3 seconds
[[draw ratio]]
The draw ratio of the amorphous carbonaceous of using as the negative electrode active material of negative pole [2] in the lithium secondary battery of the present invention is that the upper limit is generally below 10 more than 1 in theory, is preferably below 8, more preferably below 5.If surpass its upper limit, then when processing pole plate, produce striped sometimes, can't obtain uniform coated face, short time high current density charge-discharge characteristic reduces.
The ratio A/B of the major diameter A of carbonaceous material particle and perpendicular minor axis B represented when in addition, draw ratio was with three dimensional viewing.The observation of carbon particle is carried out through the scanning electron microscope that can amplify observation.Select to be fixed on 50 particles on the end face that thickness is the metallic plate below the 50 μ m arbitrarily, rotation, inclination are fixed with the objective table of sample, measure A, the B of these particles respectively, obtain the mean value of A/B.
In addition, the amorphous carbonaceous that contains in the negative electrode active material use as negative pole [2] in the lithium secondary battery of the present invention is preferably selected from the amorphous carbonaceous of following (1)～(4).
(1) will be selected from that carbide in coal class coke, petroleum-type coke, furnace black, acetylene black and the pitch-based carbon fiber is heat-treated again and the material that obtains;
(2) will be selected from organic substance and/or its thermal decomposition product and/or further heat treatment and the material that obtains in asphalt stock, aromatic hydrocarbon, N cycle compound, S cycle compound, polyphenyl, organic synthesis macromolecule, natural polymer, thermoplastic resin and the thermosetting resin;
(3) organic substance of (2) is dissolved in the small molecular organic solvent and obtains the pyrolysate of solution and/or further heat-treat and obtain material;
(4) contain the carbide of organic gas.
For (2),, can enumerate aromatic hydrocarbons such as asphalt stock, acenaphthylene, decacyclene, anthracene, phenanthrene so long as material that can carbonization gets final product; N such as azophenlyene or acridine cycle compound; S cycle compounds such as thiophene, di-thiophene; Polyphenyl such as biphenyl, terphenyl; Polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral resin, they the crosslinking Treatment thing, do not dissolve organic polymers such as handled thing, nitrogenous polyacrylonitrile, polypyrrole; Organic polymers such as the polythiophene of sulfur-bearing, polystyrene; With cellulose, lignin, mannosan, polygalacturonic acid, shitosan, sucrose is the natural polymers such as polysaccharide of representative; Thermoplastic resin such as polyphenylene sulfide, polyphenylene oxide; Thermosetting resins such as furfuryl alcohol resin, phenolic resins, imide resin; The organic substances such as solution that perhaps they are dissolved in the small molecular organic solvents such as benzene,toluene,xylene, quinoline, n-hexane and form; But contain the gas of these organic carbonizations etc.
In the middle of these, because carbon yield (carbon yield) height of asphalt stock can be made the high material of yield, so preferred.In addition, in this specification, " asphalt stock " is pitch and the material that belongs to pitch, is meant and can carries out carbonization or graphited material through proper process.As the example of concrete asphalt stock, can use tar, heavy oil or pitch etc.As the object lesson of tar, can enumerate coal tar, petroleum-type tar etc.As the object lesson of heavy oil, the contact that can enumerate petroleum-type heavy oil decomposes that oil, thermal decomposition are oily, atmospheric resids, decompression residual oil etc.In addition, as the object lesson of pitch, can enumerate coal tar asphalt, petroleum-type pitch, synthetic asphalts etc.Wherein, the armaticity of coal tar asphalt is high, so preferred.These asphalt stocks can use any one separately, also can use more than 2 kinds with combination in any and ratio combination.
As the preferred example of (3), can enumerate organic substance with above-mentioned (2) and be dissolved in the small molecular organic solvents such as benzene,toluene,xylene, quinoline, n-hexane and obtain solution, again with the pyrolysate of this solution carbide as precursor.
About (4), can enumerate hydrocarbon compounds such as methane, ethane, propane, benzene, acetylene, ethene; Carbon monoxide etc.
Preferably carry out crosslinking Treatment.So-called crosslinking Treatment is heat-treated the carbonaceous material that obtains for the asphalt stock that will carry out crosslinking Treatment etc. and is carried out difficult graphitization and carry out, and handles through implementing these, can increase the charging capacity of unit mass.
Example as crosslinking Treatment; The processing method that can be listed below: at divinylbenzene, trivinylbenzene, diallyl phthalate, ethylene glycol dimethacrylate, N; Use α in the vinyl monomers such as N-methylene-bisacrylamide as radical polymerization initiator; α '-azodiisobutyronitrile (AIBN), such crosslinking Treatment such as benzoyl peroxide (BPO), lauroyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, hydrogen peroxide; Use oxidizing gas such as oxygen, ozone, nitrogen dioxide, oxidizing liquid such as sulfuric acid, nitric acid, aqueous hydrogen peroxide solution and the oxidizer treatment of carrying out.As an example of the method for crosslinking Treatment, can be set forth under the state that the temperature that makes asphalt stock is controlled at 50 ℃～400 ℃, mix the method for handling again with crosslinking agent or oxidant etc.
[[Li-NMR moves]]
If be charged under the state of full charging, the amorphous carbonaceous that the negative electrode active material of so-called negative pole [2] in the lithium secondary battery of the present invention uses is carried out 7When Li-NMR analyzes, observed to the primary resonance peak of the downfield side shifting 80～200ppm of the resonant line of primary standard substance LiCl, so in order to increase the capacity of per unit mass amorphous carbon metallic substance, the preferred amorphous carbon metallic substance of using through crosslinking Treatment.
[[manufacture method of amorphous carbonaceous]]
As long as the preparation method of above-mentioned amorphous carbonaceous then has no particular limits in the scope that does not exceed main points of the present invention, can enumerate the whole bag of tricks.In the making of amorphous carbonaceous, must be through 1 heat treatment step, but also can heat treatment be divided into more than 2 times, also preferably in heat treated front and back and/or the heat treated interstage carry out various processing.So-called various processing can be enumerated pulverizing, classification, above-mentioned crosslinking Treatment etc., pulverizing, hierarchical processing so long as solid state then can carry out the one of any of heat treated front and back, interstage.Crosslinking Treatment is preferably being heat-treated preceding or the interstage carries out.Handle through carrying out these, can control the specific area of negative electrode active material, and increase the capacity of unit mass.
The device that uses in the pulverizing before the heat treatment has no particular limits; For example, as Roughpulverizer, can enumerate shearing mill, jaw crusher, impact type crushing machine, cone crusher etc.; As middle pulverizer; Can enumerate roll crusher, beater grinder etc.,, can enumerate ball milling, vibration milling, pin rod pulverizer, stir mill, jet mill etc. as atomizer.
The device that uses in the heat treatment as raw material; Have no particular limits; For example, can use shuttle-type stove (シ ヤ ト Le ), tunnel furnace (ト Application ネ Le
Figure BDA0000087738240000742
), electric furnace, coke baking furnace (リ one De Ha Application マ one ), reactors such as rotary furnace, autoclave, coke (heat treatment groove that cokes makes), the direct stove etc. of switching on.When handling raw material, can stir as required.
Temperature conditions when heat-treating has no particular limits, and is generally more than 600 ℃, is preferably more than 900 ℃, and in addition, its upper limit is generally below 2500 ℃, is preferably below 1300 ℃.When temperature conditions was lower than above-mentioned scope, it is low that crystallinity became, and might increase irreversible capacity.On the other hand, prescribe a time limit if surpass on it, then crystallinity becomes too high, and short time high current density charge-discharge characteristic is reduced.
For the amorphous carbonaceous after the heat treatment, can pulverize or classification according to the size of its piece material or particle.Pulverize the device that uses and have no particular limits, for example, as Roughpulverizer; Can enumerate shearing mill, jaw crusher, impact type crushing machine, cone crusher etc.; As middle pulverizer, can enumerate roll crusher, beater grinder etc., as atomizer; Can enumerate ball milling, vibration milling, pin rod pulverizer, stirring mill, jet mill etc.Classification treatment apparatus used is not particularly limited, for example, in the case of dry-sieving, using a rotary sieve, sieve shaking type, rotary sieve (sieve rotating type), vibration sieve, etc., the dry case of air classification, gravity classifier can be used, the inertia force classifier machine-type centrifugal classifier (classifier, a cyclone), etc. In addition, the wet sieving using a mechanical wet classifier, hydraulic classifier , sedimentation grading machine, centrifugal wet grading machines.
[making the electrode of negative pole [2]]
The manufacturing of negative pole [2] can be adopted usual way, can with the above-mentioned negative pole [2] that likewise forms.The thickness ratio of collector body, collector body and active material layer, electrode density, adhesive, pole plate orientation ratio, impedance etc. are also same as described above.
< negative pole [3] >
Below, the negative pole [3] that uses in the lithium secondary battery of the present invention is described, this negative pole contains metal oxide as negative electrode active material, and said metal oxide contains can occlusion and emit the titanium of lithium.
[negative electrode active material of negative pole [3]]
Below, the negative electrode active material that uses in the anticathode [3] describes.
[[formation of negative electrode active material]]
The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [3] contains metal oxide, and said metal oxide contains can occlusion and emit the titanium of lithium.In metal oxide, the composite oxides of preferred, lithium and titanium (below, abbreviate " lithium-titanium composite oxide " as), in addition, this metal oxide preferably has the titanium-containing metal oxide of spinel structure.In addition, in the negative electrode for lithium secondary battery active material, use the metal oxide that satisfies these conditions simultaneously, when just containing lithium-titanium composite oxide, can significantly reduce output impedance, so preferred especially with spinel structure.
In addition, lithium in the preferred, lithium titanium composite oxide or titanium for example are selected from least a element substitution among Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb by other metallic elements.
This metal oxide is the lithium-titanium composite oxide of general formula (1) expression, the Stability Analysis of Structures during from the doping of lithium ion/dedoping, and preferably in general formula (1), 0.7≤x≤1.5,1.5≤y≤2.3,0≤z≤1.6.
Li xTi yM zO 4 (1)
[in the general formula (1), M representes to be selected from least a element among Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and the Nb].
In the composition of above-mentioned general formula (1) expression, below shown in structure because the balance of battery performance is good, so preferred especially.
At general formula (1) Li xTi yM zO 4In,
(a)1.2≤x≤1.4、1.5≤y≤1.7、z＝0
(b)0.9≤x≤1.1、1.9≤y≤2.1、z＝0
(c)0.7≤x≤0.9、2.1≤y≤2.3、z＝0
The consisting of of preferred representative especially of above-claimed cpd: (a) be Li 4/3Ti 5/3O 4, (b) be Li 1Ti 2O 4, (c) be Li 4/5Ti 11/5O 4
In addition, for the structure of Z ≠ 0, for example can enumerate Li 4/3Ti 4/3Al 1/3O 4As preferred composition.
[[rerum natura of negative electrode active material, shape etc.]]
The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [3] also satisfies at least a in the following rerum natura preferably except above-mentioned important document.In addition, especially preferably except above-mentioned important document, satisfy simultaneously in the following rerum natura more than at least 2 kinds.
[[[BET specific area]]]
The specific area that the metal oxide that contains titanium that the negative electrode active material of the negative pole in the lithium secondary battery of the present invention [3] uses is measured through the BET method is preferably 0.5m 2More than/the g, 0.7m more preferably 2More than/the g, be preferably 1.0m especially 2More than/the g, further be preferably 1.5m 2More than/the g.Its upper limit is preferably 200m 2Below/the g, 100m more preferably 2Below/the g, be preferably 50m especially 2Below/the g, further be preferably 25m 2Below/the g.If the value of BET specific area is lower than this scope, then under situation about using as negative material, the response area that contacts with nonaqueous electrolytic solution reduces, and output impedance increases sometimes.On the other hand, if the value of BET specific area surpasses this scope, the crystal surface or the end face part that then contain the metal oxide of titanium increase, and also produce the inequality (askew) of crystallization thus, and irreversible capacity becomes and can not ignore, and can not get preferred battery sometimes.
The BET specific area is defined as following value: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation, 350 ℃ to sample carry out 15 minutes predrying; Then, use nitrogen accurately to be adjusted into 0.3 nitrogen helium gas mixture body, adsorb the value that BET1 point method is measured through the nitrogen that adopts the gas flow method with respect to atmospheric relative pressure value.
[[[volume average particle size]]]
(the primary particle cohesion and when forming offspring of the volume average particle size of the metal oxide that contains titanium that uses as the negative electrode active material of negative pole [3] in the lithium secondary battery of the present invention; Be aggregate particle size) be defined as the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method; Be preferably more than the 0.1 μ m; More preferably more than the 0.5 μ m, further be preferably more than the 0.7 μ m.In addition, its upper limit is generally below the 50 μ m, is preferably below the 40 μ m, more preferably below the 30 μ m, further is preferably below the 25 μ m.If be lower than above-mentioned scope, then when making electrode, need a large amount of adhesives, result's battery capacity sometimes reduces.In addition, if surpass above-mentioned scope, when then processing the pole plate of electrode, forming uneven coated face easily, is not preferred sometimes on the battery production process.
[[[average primary particle diameter]]]
Primary particle cohesion and when forming offspring is preferably more than the 0.01 μ m as the average primary particle diameter as the metal oxide that contains titanium of the negative electrode active material of lithium secondary battery of the present invention, more preferably more than the 0.05 μ m; Further be preferably more than the 0.1 μ m; Most preferably be more than the 0.2 μ m, its upper limit is preferably below the 2 μ m, more preferably below the 1.6 μ m; Further be preferably below the 1.3 μ m, most preferably be below the 1 μ m.If average primary particle diameter surpasses the above-mentioned upper limit, then be difficult to form spherical offspring, the powder fillibility is brought harmful effect, perhaps specific area significantly reduces, and therefore, the possibility that battery performances such as output characteristic reduce uprises sometimes.On the contrary, if average primary particle diameter is lower than above-mentioned lower limit,, therefore produce the problems such as invertibity difference that discharge and recharge sometimes then usually because crystallization is incomplete.
Primary particle size can be measured through the observation of using scanning electron microscopy (SEM).Particularly, obtain: in the photo of 10000～100000 times of multiplying powers, 50 primary particles are arbitrarily obtained the greatest length of the section that the right sides boundary line by primary particle on the straight line of horizontal direction produces, and got its mean value through following method.
[[[shape]]]
This shape of particle that contains the metal oxide of titanium of using in the negative pole of lithium secondary battery of the present invention [3] can be used the bulk in the past used, polyhedral, spherical, oval spherical, tabular, needle-like, column etc.; Wherein, Preferred primary particle cohesion and form offspring, and this offspring be shaped as spherical or oval spherical.Usually, electrochemical element is along with it discharges and recharges, and the active material in the electrode expands and shrinks, and therefore takes place easily because deteriorations such as the destruction of the active material that this stress causes or conductive path cut-outs.Therefore, compare with the single particle active material that is primary particle, preferred primary particle condenses and the situation of formation offspring, can relax the stress that expansion is shunk because form offspring, thus the deterioration of preventing.In addition; Compare with the particle of axle orientation such as tabular; Preferred spherical or oval spherical particle, because the spherical or oval spherical orientation of particle when electrode moulding is few, the expansion of the electrode when discharging and recharging is shunk also few; And when making electrode during with the mixing of conductive agent, also easy and uniform mixing.
[[[tap density]]]
The tap density of the metal oxide that contains titanium that the negative electrode active material as negative pole [3] in the lithium secondary battery of the present invention uses is preferably 0.05g/cm 3More than, 0.1g/cm more preferably 3More than, further be preferably 0.2g/cm 3More than, be preferably 0.4g/cm especially 3More than.In addition, its upper limit is preferably 2.8g/cm 3Below, 2.4g/cm more preferably 3Below, be preferably 2g/cm especially 3Below.If tap density is lower than this scope, be difficult to improve packed density when then using as negative pole, and the minimizing of interparticle contact area, therefore interparticle impedance increases, and increases output resistance sometimes.On the other hand, if surpass this scope, then the interparticle space in the electrode is very few, and the stream of nonaqueous electrolytic solution can reduce, and therefore increases output resistance sometimes.
In the present invention, tap density is as giving a definition: make sample pass through the sieve of aperture 300 μ m, make sample fall into 20cm 3The jolt ramming container in; Be full of the upper surface of container to sample after, use powder density determination device (for example, the Tap densor of seishin enterprise-like corporation manufacturing); Carry out the vibration of 1000 length of stroke 10mm, the density that the volume with thus time the and the weight of sample are obtained is as tap density.
[[[circularity]]]
The circularity of the metal oxide that contains titanium that uses as the negative electrode active material of negative pole [3] in the lithium secondary battery of the present invention is generally more than 0.10, is preferably more than 0.80, more preferably more than 0.85, further is preferably more than 0.90.As the upper limit, circularity is to become theoretic proper sphere at 1 o'clock.If be lower than this scope, then the fillibility of negative electrode active material reduces, and interparticle impedance increases, and short time high current density charge-discharge characteristic reduces sometimes.
Circularity of the present invention defines with following formula.
Circularity=(having girth)/(perimeter of particle projection of shape) with particle projection of shape equivalent circular of the same area
Use following value as the value of circularity: for example use flow-type particle picture analytical equipment (for example; The FPIA of Sysmex Industrial manufactured); About 0.2g sample is scattered in the 0.2 quality % aqueous solution (about 50mL) of polyoxyethylene (20) Span-20 as surfactant; Behind the ultrasonic wave with 1 minute 28kHz of the power output of 60W irradiation; Specifying 0.6～400 μ m is detection range, and the particle of particle diameter 3～40 mu m ranges is measured and the value that obtains.
[[[draw ratio]]]
The draw ratio of the metal oxide that contains titanium that uses as the negative electrode active material of negative pole [3] in the lithium secondary battery of the present invention is more than 1 in theory, on be limited to below 5, be preferably below 4, more preferably below 3, further be preferably below 2.If surpass its upper limit, then when processing pole plate, produce striped sometimes, can't obtain uniform coated face, short time high current density charge-discharge characteristic reduces.
In addition, the major diameter of particle is set at A during with three dimensional viewing, and when perpendicular minor axis was set at B, draw ratio was represented with A/B.The observation of particle is carried out through the scanning electron microscope that can amplify observation.Select to be fixed on 50 graphite particles on the end face that thickness is the metallic plate below the 50 μ m arbitrarily, rotation, inclination are fixed with the objective table of sample, measure A, the B of these particles respectively, obtain the mean value of A/B.
[[autofrettage of negative electrode active material]]
As the autofrettage of the negative electrode active material of the negative pole in the lithium secondary battery of the present invention [3], not special restriction can be enumerated several method in being no more than the scope of main idea of the present invention, can use the usual way as the autofrettage of inorganic compound.For example can enumerate raw material and LiOH, the Li of other elements that use with titanium material materials such as titanium oxide, as required 2CO 3, LiNO 3Evenly mix in the Li source, at high temperature sintering and obtain the method for active material.Particularly when making spherical or oval spherical active material; Can consider the whole bag of tricks; Method for example can be listed below: the raw material dissolving of other elements that use with titanium material materials such as titanium oxide, as required or grinding dispersion are regulated pH while stirring in the water equal solvent, make and obtain spherical precursor; After being dried as required, add LiOH, Li 2CO 3, LiNO 3In the Li source, sintering and obtain the method for active material at high temperature; The raw material dissolving of other elements that use with titanium material materials such as titanium oxide, as required or grinding dispersion are dried moulding through spray dryer etc. again in the water equal solvent, process spherical or oval spherical precursor, add LiOH, Li then therein 2CO 3, LiNO 3In the Li source, sintering and obtain the method for active material at high temperature; And with titanium material materials such as titanium oxide and LiOH, Li 2CO 3, LiNO 3Deng the raw material dissolving of Li source and other elements of using as required or grinding dispersion in the water equal solvent; Be dried moulding through spray dryer etc. again; Process spherical or oval spherical precursor, at high temperature its sintering is obtained the method for active material etc. then.
In addition; In these operations; Can also be in containing the metal oxide structures of titanium and/or with contain the form that titanyl compound contacts and have the element except that Ti, for example Al, Mn, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, C, Si, Sn, Ag.Through containing these elements, can control operating voltage, the capacity of battery.
[making the electrode of negative pole [3]]
The manufacturing of negative pole [3] can be adopted usual way, can with the above-mentioned negative pole [3] that likewise forms.The thickness ratio of collector body, collector body and active material layer, electrode density, adhesive, pole plate orientation ratio, impedance etc. are also same as described above.
< negative pole [4] >
Below, the negative pole [4] that uses in the lithium secondary battery of the present invention is described, this negative pole contains carbonaceous material as negative electrode active material, and the circularity of said carbonaceous material is more than 0.85, surface functional group amount O/C value is 0～0.01.
[negative electrode active material of negative pole [4]]
Below, the negative electrode active material that uses in the anticathode [4] describes.
The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [4] contains meet the following conditions (a) and carbonaceous material (b) at least.
(a) circularity is more than 0.85;
(b) surface functional group amount O/C value is 0～0.01.
Below, the details of the carbonaceous material used among the present invention is described.
[[circularity]]
The circularity of carbonaceous material is generally more than 0.85, is preferably more than 0.87, more preferably more than 0.89, is preferably more than 0.92 especially.As the upper limit, circularity is to become theoretic proper sphere at 1 o'clock.If be lower than this scope, then the fillibility of negative electrode active material reduces, and it is difficult that the compacting of negative electrode becomes, the destruction that causes particle during compacting, and the high temperature of particle inside under low depth of charge is preserved the surface of patience difference and possibly exposed easily.
Said circularity defines with following formula among the present invention.
Circularity=(having girth)/(perimeter of particle projection of shape) with particle projection of shape equivalent circular of the same area
Use following value as the value of circularity: for example use flow-type particle picture analytical equipment (for example; The FPIA of Sysmex Industrial manufactured); About 0.2g sample is scattered in the 0.2 quality % aqueous solution (about 50mL) of polyoxyethylene (20) Span-20 as surfactant; Behind the ultrasonic wave with 1 minute 28kHz of the power output of 60W irradiation; Specifying 0.6～400 μ m is detection range, and the particle of particle diameter 3～40 mu m ranges is measured and the value that obtains.
[[O/C value]]
The surface functional group amount O/C value of carbonaceous material is necessary for 0～0.01.The upper limit of O/C value is preferably below 0.005, approaches 0 preferred more more.
Said O/C value is to use the ratio of the surface functional group amount of X ray photoelectricity optical spectroscopy (XPS) mensuration among the present invention; If surface functional group amount O/C value surpasses above-mentioned scope; Then the amount of functional groups of particle surface increases; When under having the condition of specific compound, charging, the SEI coverlay that the surface generates stable insufficient, the reduction that causes hanging down the high temperature preservation characteristics under the depth of charge sometimes.
The ratio of the molar concentration of the oxygen atom that exists in the surface of surface functional group amount O/C value representation graphite material etc. and the molar concentration of carbon atom is the indexs of functional groups such as expression carboxyl, phenol property hydroxyl, carbonyl at the amount on surface.The big material with carbon element of surface functional group amount O/C value is combined with surface oxygen functional group at crystallite end face of particle face carbon etc. mostly.In addition, as the surface functional group amount O/C value of graphite material, use following value: in X ray photoelectricity optical spectroscopy is analyzed, obtain the peak area of the spectrum of C1s and O1s, the atomic concentration that calculates C and O thus is than (O atomic concentration/C atomic concentration).The not special restriction of concrete mensuration program as the example, is described below.
Promptly; (for example use X ray photoelectricity optical splitter; The ESCA of ulvac-phi (ア Le バ Star Network Off ア イ) manufactured) measures as X ray photoelectricity optical spectroscopy; Determination object (here for graphite material) is placed on the test portion platform and makes have an even surface, as x-ray source, measure C1s (280～300eV) and O1s (525～545eV) spectrum through multiplexed mensuration with the K alpha ray of aluminium.The summit of the C1s that obtains is set at 284.3eV carries out charged compensation, obtain the peak area of the spectrum of C1s and O1s, multiply by device sensitivity coefficient again, calculate the surface atom concentration of C and O respectively.The atomic concentration that calculates this O that obtains and C is defined as the surface functional group amount O/C value of graphite material than O/C (O atomic concentration/C atomic concentration) with it.
The carbonaceous material of using among the present invention satisfies the condition of above-mentioned " circularity " and " surface functional group amount O/C value ", but this puts from the balance of battery, more preferably further satisfies each or multinomial condition in the following project simultaneously.In the middle of these, preferably satisfy each or multinomial condition in tap density, Raman R value and the volume average particle size simultaneously.
[[tap density]]
The tap density of carbonaceous material is generally 0.55g/cm 3More than, be preferably 0.7g/cm 3More than, 0.8g/cm more preferably 3More than, be preferably 0.9g/cm especially 3More than.In addition, its upper limit is preferably 2g/cm 3Below, 1.8g/cm more preferably 3Below, be preferably 1.6g/cm especially 3Below.If tap density is lower than this scope, be difficult to improve packed density when then using as negative pole, can not obtain the battery of high power capacity sometimes.On the other hand, if surpass this scope, then the interparticle space in the electrode is very few, is difficult to guarantee interparticle conductivity, is difficult to obtain preferred battery behavior sometimes.
In the present invention, tap density is as giving a definition: make sample pass through the sieve of aperture 300 μ m, make sample fall into 20cm 3The jolt ramming container in, be full of the upper surface of container to sample after, (for example use the powder density determination device; The Tap densor that seishin enterprise-like corporation makes); Carry out the vibration of 1000 length of stroke 10mm, the volume and weight bulk density in the time of thus should be worth as tap density.
[[Raman R value, half breadth]]
Use the R value of the carbonaceous material of argon laser Raman spectroscopy mensuration to be generally more than 0.001, be preferably more than 0.01, its upper limit is generally below 0.2, is preferably below 0.18, more preferably the scope below 0.15.If the R value is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, when under having the condition of specific compound, charging, and the SEI coverlay that the surface generates stable insufficient, the reduction that causes hanging down the high temperature preservation characteristics under the depth of charge sometimes.
In addition, carbonaceous material is at 1580cm -1Near Raman half breadth has no particular limits, and is generally 10cm -1More than, be preferably 15cm -1More than, the upper limit is generally 35cm -1Below, be preferably 30cm -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if be higher than this scope, then the crystallinity of particle surface reduces, when under having the condition of specific compound, charging, and the SEI coverlay that the surface generates stable insufficient, the reduction that causes hanging down the high temperature preservation characteristics under the depth of charge sometimes.
The mensuration of Raman spectrum is carried out as follows: (for example use raman spectroscopy; The raman spectroscopy device of Japan's beam split manufactured); Sample is dropped into naturally measure in the container, carry out sample and fill, the mensuration process is; To the specimen surface in container irradiation argon laser, make simultaneously this container with the face of laser vertical in rotate.For the Raman spectrum that obtains, measure 1580cm -1Near peak P AIntensity I AAnd 1360cm -1Near peak P BIntensity I B, calculate its strength ratio R (R=I B/ I A), it is defined as the Raman R value of carbonaceous material.In addition, measure the Raman spectrum obtain at 1580cm -1Near peak P AHalf breadth, it is defined as the Raman half breadth of carbonaceous material.
In addition, the Raman condition determination here is following.
Argon laser wavelength: 514.5nm
Laser power on the sample: 15～25mW
Resolution: 10～20cm -1
Measurement range: 1100cm -1～1730cm -1
R value, half breadth analysis: background is handled
Smooth treatment: simple average, convolution 5 points
[[volume reference average grain diameter]]
The volume reference average grain diameter of carbonaceous material is the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method, is generally more than the 1 μ m, is preferably more than the 3 μ m, more preferably more than the 5 μ m, further is preferably more than the 7 μ m.In addition, its upper limit is generally below the 50 μ m, is preferably below the 40 μ m, more preferably below the 30 μ m, further is preferably below the 25 μ m.If be lower than above-mentioned scope, then irreversible capacity increases, and causes the loss of the battery capacity at initial stage sometimes.In addition, if surpass above-mentioned scope, when then processing the pole plate of electrode, forming uneven coated face easily, is not preferred sometimes on the battery production process.
In addition, in the particle diameter of volume reference, the ratio (d of 90% particle diameter of its distribution and 10% particle diameter 90/ d 10) be more than 1.2, be preferably more than 1.5, more preferably more than 1.7.On be limited to below 8, be preferably below 5, more preferably below 4, further be preferably the scope below 3.
In the present invention; The volume reference average grain diameter defines with median particle diameter; Said median particle diameter is measured through following method: carbon dust is dispersed in the 0.2 quality % aqueous solution (about 1mL) of polyoxyethylene (20) Span-20 as surfactant; Use laser diffraction/diffuse transmission type particle size distribution meter (for example, the hole field makes the LA-700 of institute's manufactured) to measure.Ratio (d as 90% particle diameter and 10% particle diameter 90/ d 10), can likewise measure volume reference 90% particle diameter and 10% particle diameter, and use its ratio (d 90/ d 10).
[[X ray parameter]]
Carbonaceous material is preferably more than the 0.335nm through the d value (interfloor distance) of the lattice plane (002) that X-ray diffraction that adopt to learn the method for shaking is tried to achieve.In addition, on be limited to below the 0.340nm, be preferably below the 0.337nm.If the d value is excessive, then crystallinity reduces, and increases the initial stage irreversible capacity sometimes.On the other hand, 0.335 is the theoretical value of graphite.In addition, the crystallite size (Lc) of the material with carbon element of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is generally more than the 30nm, is preferably more than the 50nm, more preferably the above scope of 80nm.If be lower than this scope, then the crystallinity of particle reduces, and might increase the initial stage irreversible capacity.
[[ash content]]
Contained ash content is below the 1 quality % with respect to the gross mass of carbonaceous material in the carbonaceous material, is preferably below the 0.5 quality %, is preferably especially below the 0.1 quality %, is limited to more than the 1ppm under it.If surpass above-mentioned scope, can not ignore with the reaction of electrolyte and the deterioration of the battery performance that causes when then discharging and recharging.If be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
[[BET specific area]]
Use the specific area of the carbonaceous material of BET method mensuration to be generally 0.1m 2More than/the g, be preferably 0.7m 2More than/the g, 1m more preferably 2More than/the g, further be preferably 1.5m 2More than/the g.Its upper limit is generally 100m 2Below/the g, be preferably 25m 2Below/the g, 15m more preferably 2Below/the g, further be preferably 10m 2Below/the g.If the value of specific area is lower than above-mentioned scope, then under situation about using as negative material, the acceptance variation of lithium when charging, lithium is separated out at electrode surface easily.On the other hand, if surpass above-mentioned scope, then when using as negative material, with the reactivity increase of electrolyte, it is many that the gas of generation becomes, and is difficult to obtain preferred battery sometimes.
The BET specific area is defined as the value of following mensuration: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation, 350 ℃ to sample carry out 15 minutes predrying; Then, use nitrogen accurately to be adjusted into 0.3 nitrogen helium gas mixture body, measure through the nitrogen absorption BET1 point method that adopts the gas flow method with respect to atmospheric relative pressure value.
[[micropore distribution]]
Space in the particle that is equivalent to diameter 0.01 μ m～1 μ m of the carbonaceous material of trying to achieve through mercury porosimeter (mercury penetration method), since the concavo-convex amount that causes that is uneven of particle surface be generally more than the 0.01mL/g; Be preferably more than the 0.05mL/g; More preferably more than the 0.1mL/g; The upper limit is generally below the 0.6mL/g, is preferably below the 0.4mL/g, more preferably the scope below the 0.3mL/g.If surpass this scope, need a large amount of adhesives when then manufacturing pole plate sometimes.On the other hand, if be lower than this scope, then the high current density charge-discharge characteristic reduces, and, the alleviation effects that the electrode in the time of can not obtaining discharging and recharging sometimes expands and shrinks.
In addition, total micropore volume is preferably more than the 0.1mL/g, and more preferably more than the 0.25mL/g, its upper limit is generally below the 10mL/g, is preferably below the 5mL/g, more preferably the scope below the 2mL/g.If surpass this scope, then when processing substrate, need a large amount of adhesives sometimes.If be lower than this scope, then when processing pole plate, can not obtain the dispersion effect of thickener or binding agent sometimes.
In addition, average micropore diameter is preferably more than the 0.05 μ m, more preferably more than the 0.1 μ m, further is preferably more than the 0.5 μ m, and its upper limit is generally below the 50 μ m, is preferably below the 20 μ m, more preferably the scope below the 10 μ m.If surpass this scope, then need a large amount of adhesives sometimes.On the other hand, if be lower than this scope, then the high current density charge-discharge characteristic reduces sometimes.
As the device that is used for the mercury porosimeter, can use mercury porosimeter (autopore9520; The micrometritics manufactured).The about 0.2g sample of weighing (negative material) is encapsulated into powder with in the container, carries out the degassing in 10 minutes at (below the 50 μ mHg) under room temperature, the vacuum, implements pre-treatment.Then, be decompressed to 4psia (about 28kPa), import mercury, boost to 40000psia (about 280MPa), be depressurized to 25psia (about 170kPa) then from 4psia (about 28kPa) stage shape.Number of stages when boosting is more than 80 stages, in each stage, after 10 seconds equilibration time, measures the mercury amount of being pressed into.Use the Washburn formula to be pressed into opisometer and calculate the micropore distribution from the mercury that obtains like this.In addition, the surface tension of mercury (γ) is 485dyne/cm, and contact angle (φ) is 140 °.Average micropore diameter uses the accumulation micro pore volume to reach 50% o'clock micropore diameter.
[[real density]]
The real density of carbonaceous material is generally 2g/cm 3More than, be preferably 2.1g/cm 3More than, 2.2g/cm more preferably 3More than, further be preferably 2.22g/cm 3More than, be limited to 2.26g/cm on it 3Below.On be limited to the theoretical value of graphite.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.In the present invention, real density is defined as the value of measuring through the liquid phase displacement method (hydrometer method) of using butanols.
[[orientation ratio]]
The orientation ratio of carbonaceous material is generally more than 0.005, is preferably more than 0.01, and more preferably more than 0.015, the upper limit is the scope below 0.67 in theory.If be lower than this scope, then the high density charge-discharge characteristic reduces sometimes.
Orientation ratio is measured through X-ray diffraction.Use asymmetric Pearson VII as distribution function, (110) diffraction of the carbon that match obtains through X-ray diffraction and the peak of (004) diffraction carry out the peak and separate, and calculate the integrated intensity at the peak of (110) diffraction and (004) diffraction respectively.Calculate by the ratio that (110) diffraction integral intensity/(004) diffraction integral intensity is represented by the integrated intensity that obtains, this ratio is defined as the active material orientation ratio.
The X-ray diffraction condition determination here is following.In addition, " 2 θ " expression angle of diffraction.
The monochromatic photometer of target: Cu (K alpha ray) graphite
Slit: divergent slit=1 degree receives optical slits=0.1mm, scatter slit=1 degree
Measurement range and step angle/minute
(110) face: 76.5 degree≤2 θ≤78.5 degree 0.01 are spent/3 seconds
(004) face: 53.5 degree≤2 θ≤56.0 degree 0.01 are spent/3 seconds
[[draw ratio]]
The draw ratio of carbonaceous material is more than 1 in theory, on be limited to below 10, be preferably below 8, more preferably below 5.If surpass its upper limit, striped can be produced when processing pole plate, uniform coated face can't be obtained, the high current density charge-discharge characteristic reduces sometimes.
The ratio A/B of the major diameter A of particle and perpendicular minor axis B represented when in addition, draw ratio was with three dimensional viewing.The observation of particle is carried out through the scanning electron microscope that can amplify observation.Selection is fixed on any 50 graphite particles on the end face of the metal of thickness below 50 microns, rotation, tilts to be fixed with the objective table of sample, measures A, the B of these particles respectively, obtains the mean value of A/B.
[[autofrettage of carbonaceous material and raw material]]
The carbonaceous material of using among the present invention can be the natural material of producing, and also can be made material, but preferably comes from the material of native graphite.In addition, natural material of producing or made material also can apply specific processing.The not special restriction of manufacturing approach (also comprising method for separating) for example, can be to use stage division sortings such as screening or air classification to have the carbonaceous material of above-mentioned characteristic and the material obtained.
In the middle of these, from the operation of easy acquisition, front handling ease this put, preferably through the natural material with carbon element of producing (native graphite raw material) is heat-treated the carbonaceous material that obtains.In addition; From viewpoints such as raising fillibilities; The preferred following carbonaceous material that obtains: natural material with carbon element of producing (native graphite raw material) or made material with carbon element are applied the mechanics energy process and carry out modification, spheroidization, again the spheroidization carbonaceous that obtains is heat-treated.In addition, from the viewpoints such as balance of the performance of lithium secondary battery, the carbonaceous material that especially preferably is prepared as follows: the native graphite raw material is applied the mechanics energy process, and the spheroidization native graphite that obtains is heat-treated.Below, sometimes the material with carbon element (raw material) before the heat treatment of above-mentioned native graphite raw material etc. only is called " raw material before the heat treatment ".
[[native graphite raw material]]
As stated, as the raw material of carbonaceous material, special preferred natural graphite.
Native graphite is according to its proterties; Be classified as flaky graphite (Flake Graphite), flaky graphite (Crystalline (Vein) Graphite), soil graphite (Amorphous Graphite) (referring to " powder body technology technology is integrated "; (strain) industrial technology center, one in the graphite of clear and distribution in 49 years; And " HAND BOOK OF CARBON, GRAPHITE, DIAMOND AND FULLERENES ", Noyes Publications distribution).Degree of graphitization is the highest with flaky graphite, is 100%, then is flaky graphite, be 99.9%, and soil graphite is low to moderate 28%.The quality of native graphite is mainly confirmed according to the place of production and mineral ore.Flaky graphite mainly originates from Madagascar, China, Brazil, Ukraine, Canada etc.; Flaky graphite mainly originates from Sri Lanka, and the main product ground of soil graphite is the Korea peninsula, China, Mexico etc.In these native graphites, because flaky graphite and flaky graphite have advantages such as degree of graphitization height, impurity level are few, therefore preferred raw material as carbonaceous material.
[[[mechanics energy process, spheroidization are handled]]]
Carrying out the mechanics energy process, to make the volume average particle size before and after handling be below 1.So-called " the volume average particle size ratio before and after handling " is the value that the volume average particle size after handling obtains divided by the volume average particle size before handling.It is below 1 that the mechanics energy process of carrying out in order to make the raw material before the heat treatment in the present invention, preferably makes the average grain diameter ratio before and after handling.
The mechanics energy process is to reduce particle size so that the average grain diameter ratio of powder particle before and after handling is below 1, controls shape of particle simultaneously and the processing carried out.In the engineering unit operation that pulverizing, classification, mixing, granulation, surface modification, reaction etc. can effectively utilize in seed designs, the mechanics energy process belongs to pulverization process.
The so-called pulverizing is meant material is applied power, and its size is reduced with the particle diameter of regulating material or particle size distribution, fillibility.Pulverization process is classified according to kind, the processing form of the power that material is applied.The power that material is applied roughly is divided into following 4 kinds: (1) beats that power (impulsive force), (2) crushing force (compression stress), (3) grind power (grinding power), the power of scraping (shearing force) is cut in (4).On the other hand, handle form and roughly be divided into following 2 kinds: pulverize on the surface of pulverizing and cut particle surface at the inner volume that produces be full of cracks and make it to propagate of particle.Volume is pulverized and can be adopted impulsive force, compression stress, shearing force to carry out; The surface pulverizing can adopt the power of grinding, shearing force to carry out.Pulverizing is with the kind of the power that these materials are applied and handles the processing that form is carried out various combinations.Its combination can suitably be confirmed according to processing intent.
Though pulverize the reaction of using chemistry such as explosion or the situation that volumetric expansion is carried out arranged also, to use mechanical device such as pulverizer to carry out usually.The processing that the preferred final shared ratio of surface treatment of the pulverization process of using in the manufacturing as the spheroidization carbonaceous of raw material of the present invention uprises, and no matter have or not volume to pulverize.This is because the angle of removing the particle surface pulverizing is important so that shape of particle is imported circle.Particularly, can after the volume pulverizing of carrying out to a certain degree, carry out surface treatment again, also can carry out the volume pulverizing hardly and only carry out surface treatment, can also carry out volume simultaneously and pulverize and surface treatment.Preferably carry out the surface at last and pulverize, remove the pulverization process at angle from the surface of particle.
Carrying out the device of mechanics energy process selects from the device that can carry out above-mentioned preferred processing.The mechanics energy process can realize through using more than one the power in 4 kinds of power that above-mentioned substance is applied, but preferably main body comprised repeatedly the mechanisms such as interactional compression, friction, shearing force of particle, thereby gives impulsive force to particle.Therefore; Particularly; Preferred following device: this device has the rotor that is provided with a plurality of blades in case inside; And give the effect of machineries such as Shock Compression, friction, shearing force through the rotation of this rotor high-speed and to importing to inner material with carbon element, thereby the limit is carried out volume and is pulverized the limit and carry out surface treatment.In addition, more preferably have through making carbonaceous material circulation or convection current and give the device of the mechanism of mechanism repeatedly.
As preferred device, can enumerate hybrid system (nara machinery is made institute's manufactured), Kryptron (Network リ プ ト ロ Application) (Earth Technica (ア one ス テ Network ニ カ) manufactured), CF mill (the emerging product manufactured of space portion), mechanical fusing system (hosokawamicron (ホ ソ カ ワ ミ Network ロ Application) manufactured) etc.In the middle of these, preferred nara machinery is made the hybrid system of institute's manufactured.When using this device to handle, preferably the peripheral speed with rotor rotated is set at 30～100m/ second, more preferably is set at 40～100m/ second, further is preferably set to 50～100m/ second.In addition, processing can be that carbonaceous material is passed through, but preferably in device circulation or be detained 30 seconds with on handle, more preferably in device, circulate or be detained 1 minute with on handle.
Through carrying out the mechanics energy process like this, carbon particle becomes following particle: keep high crystalline on the whole, just the near surface of particle becomes coarse, tilts and exposes edge surface.Like this, the face that lithium ion can be come in and gone out increases, even under high current density, also have high capacity.
In general, the particle diameter of flakey, squamous, tabular material with carbon element is more little, and its fillibility has the tendency of deterioration more.This can think because following reason: since particle through pulverizing amorphization more; Perhaps " burr ", " peeling off " or the overshooting shape things such as " warpages " of particle surface generation increase; And be attached with finer reasons such as amorphous particle with to a certain degree intensity at particle surface; Like this, and big in abutting connection with the change of the impedance between the particle, fillibility is worsened.
If the amorphism of these particles reduces, shape of particle approaches sphere, even then particle diameter diminishes, and the reducing also seldom of fillibility, in theory, big particle diameter carbon dust, small particle diameter carbon dust all should show the tap density of equal extent.
[[[rerum natura of the raw material before the heat treatment]]]
The rerum natura of the raw material before the heat treatment is preferred satisfy simultaneously below shown in (1)～(11) in any one or multinomial.In addition, all the situation with above-mentioned carbonaceous material is identical for invisible assay method or definition.
(1) X ray parameter
Raw material before the heat treatment is preferably more than the 0.335nm through the d value (interfloor distance) of the lattice plane (002) that adopts the X-ray diffraction of learning the method for shaking and try to achieve.In addition, be limited to not enough 0.340nm under it, be preferably below the 0.337nm.If the d value is excessive, then crystallinity reduces, and increases the initial stage irreversible capacity sometimes.On the other hand, 0.335 is the theoretical value of graphite.In addition, the crystallite size (Lc) of the material with carbon element of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is generally more than the 30nm, is preferably more than the 50nm, more preferably the above scope of 80nm.If be lower than this scope, then crystallinity reduces, and might increase the initial stage irreversible capacity.
(2) ash content
The gross mass of the contained ash content raw material before with respect to heat treatment is generally below the 1 quality % in the raw material before the heat treatment, is preferably below the 0.5 quality %, is preferably especially below the 0.1 quality %, and its lower limit is generally more than the 1ppm.If surpass above-mentioned scope, can not ignore with the reaction of electrolyte and the deterioration of the battery performance that causes when then discharging and recharging.If be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
(3) volume reference average grain diameter
The volume reference average grain diameter of the raw material before the heat treatment is the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method, is generally more than the 1 μ m, is preferably more than the 3 μ m, more preferably more than the 5 μ m, further is preferably more than the 7 μ m.In addition, its upper limit is generally below the 50 μ m, is preferably below the 40 μ m, more preferably below the 30 μ m, further is preferably below the 25 μ m.If be lower than above-mentioned scope, then irreversible capacity increases, and causes the loss of initial stage battery capacity sometimes.In addition, if surpass above-mentioned scope, then when processing electrode pad, forming uneven coated face easily, is not preferred sometimes on the battery production process.
(4) Raman R value, Raman half breadth
The R value of the raw material that the heat treatment of using the argon laser Raman spectroscopy to measure is preceding is generally more than 0.10, is preferably more than 0.15, more preferably more than 0.17; Further be preferably more than 0.2; Its upper limit is generally below 0.8, is preferably below 0.6, more preferably the scope below 0.4.If the R value is lower than this scope, then might not carry out the spheroidization of particle, might be able to not obtain the effect that fillibility improves.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of electrolyte, causes the gas of efficient reduction or generation to increase sometimes.
In addition, the raw material before the heat treatment is at 1580cm -1Near Raman half breadth has no particular limits, and is generally 10cm -1More than, be preferably 15cm -1More than, the upper limit is generally 80cm -1Below, be preferably 60cm -1Below, 45cm more preferably -1Below, further be preferably 40cm -1Following scope.If the Raman half breadth is lower than this scope, then might not carry out the spheroidization of particle, might be able to not obtain the effect that fillibility improves.On the other hand, if be higher than this scope, then the crystallinity of particle surface reduces, with the reactivity increase of electrolyte, and the gas increase that causes efficient to reduce sometimes or produce.
(5) BET specific area
The specific area of the raw material that the heat treatment of using the BET method to measure is preceding is generally 0.1m 2More than/the g, be preferably 0.7m 2More than/the g, 1m more preferably 2More than/the g, further be preferably 1.5m 2More than/the g.Its upper limit is generally 100m 2Below/the g, be preferably 50m 2Below/the g, 15m more preferably 2Below/the g, further be preferably 10m 2Below/the g.If the value of specific area is lower than above-mentioned scope, under the situation about then using as negative material, the acceptance variation of lithium when charging, lithium is separated out at electrode surface easily.On the other hand, if surpass above-mentioned scope, specific area is reduced, produce necessary above and reaction electrolyte, it is many that the gas of generation becomes, and is difficult to obtain preferred battery sometimes.
(6) micropore distributes
Raw material before the heat treatment of trying to achieve through mercury porosimeter (mercury penetration method) be equivalent in the particle that diameter is 0.01 μ m～1 μ m the space, since the concavo-convex amount that causes that is uneven of particle surface be generally more than the 0.01mL/g; Be preferably more than the 0.05mL/g; More preferably more than the 0.1mL/g; Its upper limit is generally below the 0.6mL/g, is preferably below the 0.4mL/g, more preferably the scope below the 0.3mL/g.If surpass this scope, need a large amount of adhesives when then manufacturing pole plate.On the other hand, if be lower than this scope, then the high current density charge-discharge characteristic reduces, and, the alleviation effects that the electrode in the time of can not obtaining discharging and recharging sometimes expands and shrinks.
In addition, total micropore volume is preferably more than the 0.1mL/g, and more preferably more than the 0.25mL/g, its upper limit is generally below the 10mL/g, is preferably below the 5mL/g, more preferably the scope below the 2mL/g.If surpass this scope, then when processing substrate, need a large amount of adhesives sometimes.If be lower than this scope, then when processing pole plate, can not obtain the dispersion effect of thickener or binding agent sometimes.
In addition, average micropore diameter is preferably more than the 0.05 μ m, more preferably more than the 0.1 μ m, further is preferably more than the 0.5 μ m, and its upper limit is generally below the 50 μ m, is preferably below the 20 μ m, more preferably the scope below the 10 μ m.If surpass this scope, then need a large amount of adhesives sometimes.On the other hand, if be lower than this scope, then the high current density charge-discharge characteristic reduces sometimes.
(7) circularity
The degree of the sphere of the raw material before using circularity as heat treatment; The particle diameter of the raw material before the heat treatment is that the circularity of the particle of 3～40 mu m ranges is preferably more than 0.85; More preferably more than 0.87, be preferably especially more than 0.90, further be preferably more than 0.92.When circularity was big, the high current density charge-discharge characteristic improved, and is therefore preferred.
The method of raising circularity does not have special the qualification, but sphere is processed in the preferred above-mentioned energy enforcement spheroidization processing of passing through mechanics, because like this, and the shape neat and consistent of the inter-particle voids when processing electrode body.
(8) real density
The real density of the raw material before the heat treatment is generally 2g/cm 3More than, be preferably 2.1g/cm 3More than, 2.2g/cm more preferably 3More than, further be preferably 2.22g/cm 3More than, be limited to 2.26g/cm on it 3Below.On be limited to the theoretical value of graphite.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.
(9) tap density
The tap density of the raw material before the heat treatment is generally 0.55g/cm 3More than, be preferably 0.7g/cm 3More than, 0.8g/cm more preferably 3More than, be preferably 0.9g/cm especially 3More than.In addition, its upper limit is preferably 2g/cm 3Below, 1.8g/cm more preferably 3Below, be preferably 1.6g/cm especially 3Below.If tap density is lower than this scope, then when using as negative pole, packed density is difficult to improve, and can not obtain the battery of high power capacity sometimes.On the other hand, if be higher than this scope, then the interparticle space in the electrode is very few, is difficult to guarantee interparticle conductivity, is difficult to obtain preferred battery behavior sometimes.
(10) orientation ratio
The orientation ratio of the raw material before the heat treatment is generally more than 0.005, is preferably more than 0.01, and more preferably more than 0.015, the upper limit is the scope below 0.67 in theory.If be lower than this scope, then the high density charge-discharge characteristic reduces sometimes.
(11) draw ratio
The draw ratio of the raw material before the heat treatment is that the upper limit is generally below 10 more than 1 in theory, is preferably below 8, more preferably below 5.If surpass its upper limit, striped can be produced when processing pole plate, uniform coated face can't be obtained, the high current density charge-discharge characteristic reduces sometimes.
[[[heat treatment temperature]]]
As the heat treatment temperature of the raw material before the heat treatment, be generally more than 600 ℃, be preferably more than 1200 ℃, more preferably more than 2000 ℃, further be preferably more than 2500 ℃, be preferably the scope more than 2800 ℃ especially.Its upper limit is generally below 3200 ℃, is preferably the scope below 3100 ℃.If temperature conditions is lower than this scope, the crystallization on the graphite particle surface at random of then carrying out through spheroidization processing etc. is repaired insufficient, and Raman R value and BET specific area can not diminish sometimes.On the other hand, if surpass above-mentioned scope, then the distillation amount of graphite becomes many sometimes easily.
[[[heat treatment method]]]
Heat treatment can be through realizing through once above-mentioned temperature range.Temperature conditions is remained the not special restriction of retention time of above-mentioned scope, but be generally the time longer, and be below 168 hours than 10 seconds.
Heat treatment is being carried out under the non-active gas atmosphere such as nitrogen or under the non-oxidizable atmosphere that obtains at the gas that is produced by raw material graphite usually.But, in the stove of the type in being embedded in coke powder (tiny pitch sintered carbon), sometimes at initial mixing air.Under these circumstances, also can need not to be complete inactive atmosphere.
Device as using in the heat treatment has no particular limits, and for example, can use shuttle-type stove, tunnel furnace, electric furnace, coke baking furnace, rotary furnace, directly switch on stove, acheson furnace, resistance-heated furnace, induction heater etc.
In addition, except above-mentioned each processing, can also carry out various processing such as hierarchical processing.Hierarchical processing is in order to obtain target grain size, to remove meal and micro mist and the processing carried out.Device as using in the hierarchical processing has no particular limits, and for example, under the situation of dry type screening, can use gyratory sifter, rock type sieve, rotary type sieve, oscillatory type sieve etc.; Under the situation of dry type air current classifying, can use gravity type grader, inertia force formula grader, centrifugal force type grader (sizer, cyclone separator) etc.; Under the situation of wet screening, can use mechanical type wet classifier, hydraulic classifier, settling classifier, centrifugal wet classifier etc.Hierarchical processing can be carried out before heat treatment, also can for example carry out after the heat treatment at other times.In addition, can also omit hierarchical processing itself.But,, preferably handle and just finish the back and before heat treatment, carry out hierarchical processing at spheroidization from the productive viewpoint of powdered graphite negative material.
[[auxiliary material mixing]]
Except that above-mentioned carbonaceous material, through contain in the negative electrode active material that uses in the present invention more than one with above-mentioned carbonaceous material in carbonaceous material (carbonaceous material) different aspect the rerum natura of carbonaceous, can further seek the raising of battery performance.Here said " rerum natura of carbonaceous " is meant more than one the characteristic in X-ray diffraction parameter, median particle diameter, draw ratio, BET specific area, orientation ratio, Raman R value, tap density, real density, micropore distribution, circularity, the ash amount.In addition,, can enumerate as preferred embodiment, asymmetric about when the volume reference particle size distribution is the center with the median particle diameter, to contain Raman R value is different more than 2 kinds material with carbon element or X ray parameter not equal.As an example of its effect, can enumerate through containing graphite such as native graphite, Delanium; Carbon blacks such as acetylene black; Material with carbon elements such as amorphous carbon such as needle coke reduce resistance etc. as auxiliary material.They can use a kind of separately, also can use more than 2 kinds with combination in any and arbitrary proportion combination.When adding as auxiliary material; Its addition is generally more than the 0.1 quality %, is preferably more than the 0.5 quality %, more preferably more than the 0.6 quality %; Its upper limit is generally below the 80 quality %; Be preferably below the 50 quality %, more preferably below the 40 quality %, be preferably the scope below the 30 quality % especially.If be lower than this scope, then be difficult to obtain the effect that conductivity improves sometimes.If surpass above-mentioned scope, then cause the increase of initial stage irreversible capacity sometimes.
[making the electrode of negative pole [4]]
Make negative pole [4] and can adopt usual way, can with the above-mentioned negative pole [4] that likewise forms.The thickness ratio of collector body, collector body and active material layer, electrode density, adhesive, pole plate orientation ratio, impedance etc. are also same as described above.
< negative pole [5] >
Below, the negative pole [5] that uses in the lithium secondary battery of the present invention is described, this negative pole contains different orientation carbon complex as active material, and said different orientation carbon complex contains the different carbonaceous material of orientation more than 2 kinds.
[negative electrode active material of negative pole [5]]
Below, the negative electrode active material that uses in the anticathode [5] describes.
[[formation of different orientation carbon complex]]
The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [5] contains different orientation carbon complex, and this different orientation carbon complex contains the different carbonaceous material of orientation more than 2 kinds.
Here said " orientation is different "; Be meant the time with the polarized light microscope observing powder; The pattern of the anisotropy unit of visual contrast optical anisotropy tissue; When being the size, direction, quantity etc. of anisotropy unit, any at least one in their size, direction, the quantity etc. is different.For example can enumerate, in carbonaceous 1 and the carbonaceous 2, a crystallization direction property that has to a direction, another has the situation of random crystallization direction property; Perhaps carbonaceous 1 all has the crystallization direction property to certain orientation respectively with carbonaceous 2, but its direction condition of different etc.In addition, carbonaceous 1 and 2 kinds of carbonaceous one or both are not single crystallizations, but during the aggregate of a plurality of crystallizations, and the unit of aggregate as 1 zone, is contrasted the set pattern of the anisotropy unit of its optical anisotropy sex organization.
In addition, the form of the carbonaceous 1 in the anisotropy carbon complex, carbonaceous 2 coexistences preferably is contained in 1 offspring.Here said " being included in 1 offspring " is meant the state that the different carbonaceous material of orientation is physically retrained, adheres to; Constraint through static, adhere to the state that keeps shape; Restrained state etc. through bonding.Here said " constraint of physics, adhere to " is meant the state that a kind of carbonaceous material is mixed in the another kind of carbonaceous material, connects together; So-called " constraint of static, adhere to " be meant a kind of carbonaceous material through electrostatic energy attached to the state in the another kind of carbonaceous material.In this constraint, the state that adheres to, can be above-mentioned orientation different state, also can be original carbonaceous material is same material.In addition, so-called " through bonding restrained state " is meant chemical bondings such as hydrogen bond, covalent bond, ionic bond.
Wherein, preferably on a kind of part surface at least of carbonaceous material through adhering to and/or bonding makes another kind of carbonaceous material have the state at the different interface of orientation.Have the interface and compare with the situation that does not have the interface, when the particle of same shape compares, when charging lithium ion be mingled with and the expansion that causes is dispersed in the many-side, thereby can prevent deterioration of battery, see it is preferred from this aspect.
The formation of this orientation different portions can form through the material supplied with the outside and/or the bonding of their modifier, and the modification of the material of surface portion that perhaps can be through carbonaceous material forms.Wherein, The so-called covering; Be with the interface of part at least on the surface of carbonaceous material in have chemical bond, thereby show: the state, (2) that (1) covers whole surface be state, (3) the optionally state, the state that (4) are present in the atomic zonule that comprises chemical bond on surface, cover part of coated carbon metallic substance partly.
In addition, near interface, the orientation of carbonaceous material can change continuously, also can change discontinuously.That is, preferred different orientation carbon complex has that the different carbonaceous material of orientation is adhered to and/or bonding and the interface that forms, and the orientation of the carbonaceous material at this interface is discontinuous and/or change continuously.
In addition; Constituent as different orientation carbonaceous compound (A); As long as have crystallinity, not special the qualification put but uprise this from the charging capacity of unit mass; More than one of the carbonaceous material that preferred orientation property is different are for coming from the graphite-like carbonaceous material (B) (below, abbreviate " native graphite class carbonaceous material (B) " as) of native graphite (D).
In addition; The native graphite class carbonaceous material (B) that contains in the different orientation carbon complex is generally more than the 5 quality % with respect to the ratio of different orientation carbon complex; Be preferably more than the 20 quality %; More preferably more than the 30 quality %, further be preferably more than the 40 quality %, be preferably the above scope of 50 quality % especially.Its upper limit is generally below the 99.9 quality %, is preferably below the 99 quality %, more preferably below the 95 quality %, further is preferably the scope below the 90 quality %.If be lower than this scope, then the loading the during calendering of electrode is significantly risen, and causes peeling off of electrode etc. sometimes.On the other hand, if surpass this scope, die down during then as being bonded with of the interface of the complex of the different particle of orientation.
In addition; Other constituent as different orientation carbon complex; Interface when different orientation carbon complex prepares generates the viewpoint with the adhesiveness raising at interface, and preferably the different carbonaceous material of more than one orientations is the carbonaceous material (C) that is selected from following (1)～(5).
(1) carbide of from coal class coke, petroleum-type coke, furnace black, acetylene black and pitch-based carbon fiber, selecting;
(2) will be selected from organic substance and/or its thermal decomposition product in asphalt stock, aromatic hydrocarbon, N cycle compound, S cycle compound, polyphenyl, organic synthesis macromolecule, natural polymer, thermoplastic resin and the thermosetting resin as the carbide of precursor;
(3) organic substance of (2) is dissolved in the small molecular organic solvent and obtains the carbide of the pyrolysate of solution as precursor;
(4) contain the carbide of organic gas;
The graphitization thing of (5) (1)～(4).
For (2), so long as material that can carbonization gets final product, not special the qualification can not enumerated aromatic hydrocarbons such as asphalt stock, acenaphthylene, decacyclene, anthracene, phenanthrene; N such as azophenlyene, acridine cycle compound; S cycle compounds such as thiophene, di-thiophene; Polyphenyl such as biphenyl, terphenyl; Polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral resin, they do not dissolve organic polymers such as handled thing, nitrogenous polyacrylonitrile, polypyrrole; Organic polymers such as the polythiophene of sulfur-bearing, polystyrene; With cellulose, lignin, mannosan, polygalacturonic acid, shitosan, sucrose is the natural polymers such as polysaccharide of representative; Thermoplastic resin such as polyphenylene sulfide, polyphenylene oxide; Thermosetting resins such as furfuryl alcohol resin, phenolic resins, imide resin; The organic substances such as solution that perhaps they are dissolved in the small molecular organic solvents such as benzene,toluene,xylene, quinoline, n-hexane and form; But the gas of carbonization etc.
In the middle of these,, can make the high material of yield, so preferred because the carbon yield of asphalt stock is high.In addition, in this specification, " asphalt stock " is pitch and the material that belongs to pitch, is meant and can carries out carbonization and/or graphited material through proper process.As the example of concrete asphalt stock, can use tar, heavy oil or pitch etc.As the object lesson of tar, can enumerate coal tar, petroleum-type tar etc.As the object lesson of heavy oil, the contact that can enumerate petroleum-type heavy oil decomposes that oil, thermal decomposition are oily, atmospheric resids, decompression residual oil etc.In addition, as the object lesson of pitch, can enumerate coal tar asphalt, petroleum-type pitch, synthetic asphalts etc.Wherein, the armaticity of coal tar asphalt is high, so preferred.These asphalt stocks can use any one separately, also can use more than 2 kinds with combination in any and ratio combination.
As the preferred example of (3), can enumerate organic substance with above-mentioned (2) and be dissolved in the small molecular organic solvents such as benzene,toluene,xylene, quinoline, n-hexane and obtain solution, again with the pyrolysate of this solution carbide as precursor.
About (4), can enumerate hydrocarbon compounds such as methane, ethane, propane, benzene, acetylene, ethene; Carbon monoxide etc.
The ratio of the carbonaceous material (C) that contains in the different orientation carbon complex is generally more than the 0.1 quality %, is preferably more than the 1 quality %, more preferably more than the 5 quality %, further is preferably the above scope of 10 quality %.Its upper limit has no particular limits, as long as have the different interface of orientation.If be lower than this scope, die down during being bonded with of the interface in the then different orientation carbon complex.In addition, if surpass this scope, then because the particles Deformation when containing the compacting that carbonaceous material (C) causes suppresses effect reduces, cycle characteristics reduces.
Preferred formation as the negative electrode active material that uses in the lithium secondary battery among the present invention; The viewpoint of the compacting loading when electrode rolls and as the viewpoint of the fusible balance at the interface of complex, preferred different orientation carbon complex contains more than one native graphite class carbonaceous material (B) and more than one carbonaceous material (C) simultaneously.
Because with above-mentioned same reason; The native graphite class carbonaceous material (B) in the different orientation carbon complex and the quality ratio of carbonaceous material (C) (native graphite class carbonaceous material (B)/carbonaceous material (C)) are generally more than 20/80; Be preferably more than 40/60; More preferably more than 60/40, further be preferably the scope more than 70/30.Be limited on it below 99.9/0.1, be preferably below 99/1, more preferably the scope below 95/5.If surpass this scope (if the ratio of native graphite class carbonaceous material (B) is excessive), the adhesiveness at the interface that is then produced by carbonaceous material (C) has the possibility of reduction.On the other hand, if be lower than this scope (if the ratio of native graphite class carbonaceous material (B) is too small), it is big that the compacting loading when then electrode rolls significantly becomes, and when calendering, peels off sometimes.
As the different orientation carbon complex that contains native graphite class carbonaceous material (B) and carbonaceous material (C), only otherwise exceed the scope of purport of the present invention, then can take form arbitrarily, an example is shown below.
(1) the whole surface of native graphite class carbonaceous material (B) or part surface adheres to and/or covering and/or bonding have the form of carbonaceous material (C);
(2) carbonaceous material (C) bonds the form of native graphite class carbonaceous material (B) more than 2 and/or compoundization of carbonaceous material (C) with the whole surface or the part surface of native graphite class carbonaceous material (B);
(3) above-mentioned (1) and (2) are with the form of mixed arbitrarily.
In addition; Above-mentioned native graphite class carbonaceous material (B) can also be replaced with carbonaceous material (C); In addition, as the concrete complex method of this different orientation carbon complex, can be set forth in as surface attachment and/or the covering of the particle of nuclear and/or the form that bonding has carbonaceous material; A plurality of as the surface attachment of the particle of examining and/or the form of covering and/or bonding; Perhaps as the state etc. of non-parallel ground of the particle granulation of nuclear.Here the said state that carries out granulation is meant that particle with certain crystallinity fixed by other carbonaceous material with the state towards at random direction, thereby becomes the state with the bonding that shows different orientation non-parallelly.
[[preparation of different orientation carbon complex]]
Preparation for different orientation carbon complex; In " manufacturing approach 1 and the manufacturing approach 2 of different orientation carbon complex " of back, narrate; When the different orientation carbon complex of preparation, can seek to improve crystallinity through applying heat treatment, and can increase the capacity of per unit weight.As heat treatment temperature, be generally more than 400 ℃, be preferably more than 1000 ℃, more preferably more than 2000 ℃, further be preferably more than 2400 ℃, be preferably the scope more than 2800 ℃ especially.Its upper limit is generally below 3400 ℃, is preferably the scope below 3200 ℃.If be lower than this scope, then can not fully improve crystallinity, and might be able to not obtain the effect of the capacity increase of per unit weight.On the other hand, if surpass this scope, then, might cause the minimizing of yield because the loss that the distillation of carbon causes can not be ignored.
[[character of different orientation carbon complex]]
For character about different orientation carbon complex, preferred satisfy simultaneously below shown in (1)～(5) in any one or multinomial.
(1) circularity
Use the degree of circularity as the sphere of different orientation carbon complex; The particle diameter of different orientation carbon complex is that the circularity of the particle of 3～40 mu m ranges is generally more than 0.1, is preferably more than 0.5, more preferably more than 0.8; Further be preferably more than 0.85, most preferably be more than 0.9.When circularity was big, the high current density charge-discharge characteristic improved, and is therefore preferred.Circularity defines with following formula, and circularity is 1 o'clock, is theoretical proper sphere.
Circularity=(having girth)/(perimeter of particle projection of shape) with particle projection of shape equivalent circular of the same area
Use the following value of measuring as the value of circularity: for example use flow-type particle picture analytical equipment (for example; The FPIA of Sysmex Industrial manufactured); About 0.2g sample is scattered in the 0.2 quality % aqueous solution (about 50mL) of polyoxyethylene (20) Span-20 as surfactant; Behind the ultrasonic wave with 1 minute 28kHz of the power output of 60W irradiation, specifying 0.6～400 μ m is detection range, and the particle of particle diameter 3～40 mu m ranges is measured.
The method that improves circularity has no particular limits, but handles and make it to become sphere and can make when processing electrode body the shape of inter-particle voids neatly unified through implementing spheroidization, so preferably.As the example that spheroidization is handled, can enumerate, through apply shearing force, compression stress is come the mechanically method of subglobular, the adhesive force that has through adhesive or particle self is with the machinery/physical treatment method of a plurality of particulate granulations etc.
(2) Raman R value, Raman half breadth
Use the Raman R value of the different orientation carbon complex of argon laser Raman spectroscopy mensuration to be generally more than 0.01; Be preferably more than 0.02, more preferably more than 0.04, its upper limit is generally below 0.35; Be preferably below 0.30, more preferably the scope below 0.25.If Raman R value is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of nonaqueous electrolytic solution, causes the gas of efficient reduction or generation to increase sometimes.
In addition, material with carbon element of the present invention is at 1580cm -1Near Raman half breadth has no particular limits, but is generally 5cm -1More than, be preferably 10cm -1More than, in addition, its upper limit is generally 40cm -1Below, be preferably 35cm -1Below, 30cm more preferably -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if be higher than this scope, then the crystallinity of particle surface reduces, with the reactivity increase of nonaqueous electrolytic solution, and the gas increase that causes efficient to reduce sometimes or produce.
The mensuration of Raman spectrum is carried out as follows: use raman spectroscopy device (the raman spectroscopy device that for example Japanese beam split society makes); Sample is fallen naturally and be filled in the cell; To the specimen surface in pond irradiation argon laser, simultaneously, make the pond with the face of laser vertical in rotate.For the Raman spectrum that obtains, measure 1580cm -1Near peak P AIntensity I AAnd 1360cm -1Near peak P BIntensity I B, calculate its strength ratio R (R=I B/ I A), it is defined as the Raman R value of material with carbon element.In addition, measure the Raman spectrum obtain at 1580cm -1Near peak P AHalf breadth, it is defined as the Raman half breadth of material with carbon element.
In addition, the Raman condition determination here is following.
Argon laser wavelength: 514.5nm
Laser power on the sample: 15～25mW
Resolution: 10～20cm -1
Measurement range: 1100cm -1～1730cm -1
Raman R value, Raman half breadth are analyzed: background is handled
Smooth treatment: simple average, convolution 5 points
(3) tap density
The tap density of different orientation carbon complex is generally 0.55g/cm 3More than, be preferably 0.70g/cm 3More than, 0.9g/cm more preferably 3More than, be preferably 1g/cm especially 3More than.In addition, be preferably 2.0g/cm 3Below, 1.8g/cm more preferably 3Below, further be preferably 1.7g/cm 3Below, be preferably 1.5g/cm especially 3Below.If tap density is lower than this scope, then when using as negative pole, packed density is difficult to improve, and can not obtain the battery of high power capacity sometimes.On the other hand, if be higher than this scope, then the interparticle space in the electrode is very few, is difficult to guarantee interparticle conductivity, is difficult to obtain preferred battery behavior sometimes.
In the present invention, tap density is as giving a definition: make sample drop on 20cm through the sieve of aperture 300 μ m 3The jolt ramming container in; Be full of the upper surface of container up to sample after; Use powder density determination device (for example, the Tap densor that seishin enterprise-like corporation makes) to carry out the vibration of 1000 length of stroke 10mm, the density that the volume with thus time the and the weight of sample are tried to achieve is defined as tap density.
(4) BET specific area
Use the specific area of the different orientation carbon complex of BET method mensuration to be generally 0.1m 2More than/the g, be preferably 0.7m 2More than/the g, 1.0m more preferably 2More than/the g, further be preferably 1.2m 2More than/the g.Its upper limit is generally 100m 2Below/the g, be preferably 25m 2Below/the g, 15m more preferably 2Below/the g, further be preferably 10m 2Below/the g.If the value of specific area is lower than this scope, when then using as negative material, the easy variation of acceptance of lithium when charging, lithium is separated out at electrode surface easily.On the other hand, if be higher than above-mentioned scope, during then as negative material, with the reactivity increase of nonaqueous electrolytic solution, it is many that the gas of generation becomes easily, is difficult to obtain preferred battery sometimes.
The BET specific area is defined as the value of following mensuration: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation, under 350 ℃ to sample carry out 15 minutes predrying, then; Use nitrogen accurately to be adjusted into 0.3 nitrogen helium gas mixture body, measure through the nitrogen absorption BET1 point method that adopts the gas flow method with respect to atmospheric relative pressure value.
(5) volume reference average grain diameter
The volume reference average grain diameter of different orientation carbon complex is the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method, is generally more than the 1 μ m, is preferably more than the 3 μ m, more preferably more than the 5 μ m, further is preferably more than the 7 μ m.In addition, its upper limit is generally below the 100 μ m, is preferably below the 50 μ m, more preferably below the 40 μ m, further is preferably below the 30 μ m, is preferably especially below the 25 μ m.If be lower than above-mentioned scope, then irreversible capacity increases, and causes the loss of initial stage battery capacity sometimes.In addition, if surpass above-mentioned scope, then when processing electrode pad, forming uneven coated face easily, is not preferred sometimes on the battery production process.
In the present invention; The volume reference average grain diameter defines with median particle diameter; Said median particle diameter is measured through following method: carbon dust is dispersed in the 0.2 quality % aqueous solution (about 1mL) of polyoxyethylene (20) Span-20 as surfactant; Use laser diffraction formula particle size distribution meter (for example, the hole field makes the LA-700 of institute's manufactured) to measure.
From the viewpoint of the balance of battery behavior, preferably except above-mentioned (1)～(5), also satisfy in following (6)～(11) more than one.
(6) X ray parameter
Different orientation carbon complex is preferably more than the 0.335nm through the d value (interfloor distance) of the lattice plane (002) that X-ray diffraction that adopt to learn the method for shaking is tried to achieve, and is generally below the 0.340nm, is preferably below the 0.337nm.If be lower than this scope, then crystallinity reduces, and might increase the initial stage irreversible capacity.In addition, 0.335 of lower limit is the theoretical value of graphite.In addition, the crystallite size (Lc) of the material with carbon element of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is generally more than the 30nm, is preferably more than the 50nm, more preferably the above scope of 80nm.If be lower than this scope, then crystallinity reduces, and might increase the initial stage irreversible capacity.
(7) ash content
Contained ash content is generally below the 1 quality % with respect to the gross mass of different orientation carbon complex in the different orientation carbon complex, is preferably below the 0.5 quality %, is preferably especially below the 0.1 quality %, and its lower limit is generally more than the 1ppm.If surpass above-mentioned scope, can not ignore with the reaction of nonaqueous electrolytic solution and the deterioration of the battery performance that causes when then discharging and recharging.If be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
(8) micropore distributes
Space in the particle that is equivalent to diameter 0.01 μ m～1 μ m of the different orientation carbon complex of trying to achieve through mercury porosimeter (mercury penetration method), since the concavo-convex amount that causes that is uneven of particle surface be generally more than the 0.001mL/g; Be preferably more than the 0.002mL/g; Its upper limit is generally below the 0.6mL/g; Be preferably below the 0.4mL/g, more preferably the scope below the 0.3mL/g.If surpass this scope, need a large amount of adhesives when then manufacturing pole plate sometimes.On the other hand, if be lower than this scope, then the high current density charge-discharge characteristic reduces, and, the alleviation effects that the electrode in the time of can not obtaining discharging and recharging sometimes expands and shrinks.
In addition, total micropore volume is preferably more than the 0.1mL/g, and more preferably more than the 0.25mL/g, its upper limit is generally below the 10mL/g, is preferably below the 5mL/g, more preferably the scope below the 2mL/g.If surpass this scope, then when processing substrate, need a large amount of adhesives sometimes.If be lower than this scope, then when processing pole plate, can not obtain the dispersion effect of thickener or binding agent sometimes.
In addition, average micropore diameter is preferably more than the 0.05 μ m, more preferably more than the 0.1 μ m, further is preferably more than the 0.5 μ m, and its upper limit is generally below the 50 μ m, is preferably below the 20 μ m, more preferably the scope below the 10 μ m.If surpass this scope, then need a large amount of adhesives sometimes.On the other hand, if be lower than this scope, then the high current density charge-discharge characteristic reduces sometimes.
As the device that is used for the mercury porosimeter, can use mercury porosimeter (autopore9520; The micrometritics manufactured).The about 0.2g sample of weighing (negative material) is encapsulated into powder with in the container, carries out the degassing in 10 minutes at (below the 50 μ mHg) under room temperature, the vacuum, implements pre-treatment.Then, be decompressed to 4psia (about 28kPa), import mercury, boost to 40000psia (about 280MPa), be depressurized to 25psia (about 170kPa) then from 4psia (about 28kPa) stage shape.Number of stages when boosting is more than 80 stages, in each stage, after 10 seconds equilibration time, measures the mercury amount of being pressed into.Use the Washburn formula to be pressed into opisometer and calculate the micropore distribution from the mercury that obtains like this.In addition, the surface tension of mercury (γ) is 485dyne/cm, and contact angle (φ) is 140 °.Average micropore diameter uses the accumulation micro pore volume to reach 50% o'clock micropore diameter.
(9) real density
The real density of different orientation carbon complex is generally 2.0g/cm 3More than, be preferably 2.1g/cm 3More than, 2.2g/cm more preferably 3More than, further be preferably 2.22g/cm 3More than, be limited to 2.26g/cm on it 3Below.On be limited to the theoretical value of graphite.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.In the present invention, real density is defined as the value of measuring through the liquid phase displacement method (hydrometer method) of using butanols.
(10) orientation ratio (powder)
The orientation ratio of different orientation carbon complex is generally more than 0.005, is preferably more than 0.01, and more preferably more than 0.015, the upper limit is the scope below 0.67 in theory.If be lower than this scope, then the high density charge-discharge characteristic reduces sometimes.
Orientation ratio is measured through X-ray diffraction.Use asymmetric Pearson VII as distribution function, (110) diffraction of the carbon that match obtains through X-ray diffraction and the peak of (004) diffraction carry out the peak and separate, and calculate the integrated intensity at the peak of (110) diffraction and (004) diffraction respectively.Calculate by the ratio that (110) diffraction integral intensity/(004) diffraction integral intensity is represented by the integrated intensity that obtains, this ratio is defined as the active material orientation ratio.
The X-ray diffraction condition determination here is following.In addition, " 2 θ " expression angle of diffraction.
The monochromatic photometer of target: Cu (K alpha ray) graphite
Slit: divergent slit=1 degree receives optical slits=0.1mm, scatter slit=1 degree
Measurement range and step angle/minute
(110) face: 76.5 degree≤2 θ≤78.5 degree 0.01 are spent/3 seconds
(004) face: 53.5 degree≤2 θ≤56.0 degree 0.01 are spent/3 seconds
(11) draw ratio (powder)
The draw ratio of different orientation carbon complex is more than 1 in theory, on be limited to below 10, be preferably below 8, more preferably below 5.If surpass its upper limit, striped can be produced when processing pole plate, uniform coated face can't be obtained, the high current density charge-discharge characteristic reduces sometimes.
The ratio A/B of the major diameter A of material with carbon element particle and perpendicular minor axis B represented when in addition, draw ratio was with three dimensional viewing.The observation of particle is carried out through the scanning electron microscope that can amplify observation.Selection is fixed on any 50 graphite particles on the end face of the metal of thickness below 50 microns, rotation, tilts to be fixed with the objective table of sample, measures A, the B of these particles respectively, obtains the mean value of A/B.
[[raw material of native graphite class carbonaceous material (B)]]
As the raw material of the native graphite class carbonaceous material (B) that contains in the different orientation carbon complex, the interplanar distance (d002) that can enumerate (002) face of measuring with employing X ray wide-angle diffraction method usually shows that the high native graphite of crystallinity below the 0.340nm is the material of raw material.Particularly, be preferably selected from the powder of following material: native graphite or add therein that the mechanical disintegration thing improves circularity and the product that obtains and/or they are being heat-treated and the product that obtains, the heat treated article of expanded graphite or the high-purity purified product of these graphite more than 100 ℃.
Native graphite (D) as the precursor of native graphite class carbonaceous material (B); According to its proterties; Be classified as flaky graphite (Flake Graphite), flaky graphite (Crystalline (Vein) Graphite), soil graphite (Amorphous Graphite) (referring to " powder body technology technology is integrated "; One in the graphite of ((strain) industrial technology center, clear and distribution in 49 years); And " HAND BOOK OF CARBON, GRAPHITE, DIAMOND AND FULLERENES ", (Noyes Publications distribution)).Degree of graphitization is the highest with flaky graphite, is 100%, then is flaky graphite, be 99.9%, and soil graphite is low to moderate 28%.Flaky graphite as native graphite originates from Madagascar, China, Brazil, Ukraine, Canada etc.; Flaky graphite mainly originates from Sri Lanka.The main product ground of soil graphite is the Korea peninsula, China, Mexico etc.In these native graphites, not only particle diameter is less usually for soil graphite, and purity is low.On the contrary, because flaky graphite and flaky graphite have advantages such as degree of graphitization or impurity level are low, so can preferably use in the present invention.
[[preparation of native graphite class carbonaceous material (B)]]
For the preparation of native graphite class carbonaceous material (B), in " manufacturing approach 1 and the manufacturing approach 2 of different orientation carbon complex " of back, narrate.
[[character of native graphite class carbonaceous material (B)]]
For native graphite class carbonaceous material (B), preferred satisfy simultaneously below shown in (1)～(11) in each or multinomial.In addition, definition, the assay method partly put down in writing of separately definition, assay method etc. and different orientation carbon complex is identical.
(1) X ray parameter
Native graphite class carbonaceous is preferably more than the 0.335nm through the d value (interfloor distance) of the lattice plane (002) that X-ray diffraction that adopt to learn the method for shaking is tried to achieve, and is generally below the 0.340nm, is preferably below the 0.337nm.If be lower than this scope, then crystallinity reduces, and might increase the initial stage irreversible capacity.In addition, 0.335nm is the theoretical value of graphite.In addition, the crystallite size (Lc) of the material with carbon element of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is generally more than the 30nm, is preferably more than the 50nm, more preferably the above scope of 90nm.If be lower than this scope, then crystallinity reduces, and might increase the increase of initial stage irreversible capacity.
(2) ash content
Contained ash content is generally below the 1 quality % with respect to the gross mass of native graphite class carbonaceous in the native graphite class carbonaceous, is preferably below the 0.5 quality %, is preferably especially below the 0.1 quality %, and its lower limit is generally more than the 1ppm.If surpass above-mentioned scope, can not ignore sometimes with the reaction of nonaqueous electrolytic solution and the deterioration of the battery performance that causes when then discharging and recharging.If be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
(3) volume reference average grain diameter
The volume reference average grain diameter of native graphite class carbonaceous is the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method, is generally more than the 1 μ m, is preferably more than the 3 μ m, more preferably more than the 5 μ m, further is preferably more than the 7 μ m.In addition, its upper limit is generally below the 50 μ m, is preferably below the 40 μ m, more preferably below the 30 μ m, further is preferably below the 25 μ m.If be lower than above-mentioned scope, then irreversible capacity increases, and causes the loss of initial stage battery capacity sometimes.In addition, if surpass above-mentioned scope, then when processing electrode pad, forming uneven coated face easily, is not preferred sometimes on the battery production process.
(4) Raman R value, Raman half breadth
Use the Raman R value of the native graphite class carbonaceous of argon laser Raman spectroscopy mensuration to be generally more than 0.01; Be preferably more than 0.02, more preferably more than 0.04, its upper limit is generally below 0.35; Be preferably below 0.30, more preferably the scope below 0.25.If Raman R value is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of nonaqueous electrolytic solution, causes the gas of efficient reduction or generation to increase sometimes.
In addition, material with carbon element of the present invention is at 1580cm -1Near Raman half breadth has no particular limits, and is generally 5cm -1More than, preferred 10cm -1More than, in addition, its upper limit is generally 40cm -1Below, be preferably 35cm -1Below, 30cm more preferably -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if be higher than this scope, then the crystallinity of particle surface reduces, with the reactivity increase of nonaqueous electrolytic solution, and the gas increase that causes efficient to reduce sometimes or produce.
(5) BET specific area
Use the specific area of the native graphite class carbonaceous of BET method mensuration to be generally 0.1m 2More than/the g, be preferably 0.7m 2More than/the g, 1.0m more preferably 2More than/the g, further be preferably 1.5m 2More than/the g.Its upper limit is generally 100m 2Below/the g, be preferably 25m 2Below/the g, 15m more preferably 2Below/the g, further be preferably 10m 2Below/the g.If the value of specific area is lower than this scope, when then using as negative material, the acceptance variation of lithium when charging, lithium is separated out at electrode surface easily.On the other hand, if be higher than above-mentioned scope, during then as negative material, with the reactivity increase of nonaqueous electrolytic solution, it is many that the gas of generation becomes easily, is difficult to obtain preferred battery sometimes.
(6) micropore distributes
Space in the particle that is equivalent to diameter 0.01 μ m～1 μ m of the native graphite class carbonaceous of trying to achieve through mercury porosimeter (mercury penetration method), since the concavo-convex amount that causes that is uneven of particle surface be generally more than the 0.01mL/g; Be preferably more than the 0.05mL/g; More preferably more than the 0.1mL/g; Its upper limit is generally below the 0.6mL/g, is preferably below the 0.4mL/g, more preferably the scope below the 0.3mL/g.If surpass this scope, need a large amount of adhesives when then manufacturing pole plate sometimes.If be lower than this scope, then the high current density charge-discharge characteristic reduces, and, the alleviation effects that the electrode in the time of can not obtaining discharging and recharging sometimes expands and shrinks.
In addition, total micropore volume is preferably more than the 0.1mL/g, and more preferably more than the 0.25mL/g, its upper limit is generally below the 10mL/g, is preferably below the 5mL/g, more preferably the scope below the 2mL/g.If surpass this scope, then when processing substrate, need a large amount of adhesives sometimes.If be lower than this scope, then when processing pole plate, can not obtain the dispersion effect of thickener or binding agent sometimes.
In addition, average micropore diameter is preferably more than the 0.05 μ m, more preferably more than the 0.1 μ m, is preferably especially more than the 0.5 μ m, and its upper limit is generally below the 50 μ m, is preferably below the 20 μ m, more preferably the scope below the 10 μ m.If surpass this scope, then need a large amount of adhesives sometimes.If be lower than this scope, then the high current density charge-discharge characteristic reduces sometimes.
(7) circularity
Use the degree of circularity as the sphere of native graphite class material with carbon element; The particle diameter of native graphite class material with carbon element is that the circularity of the particle of 3～40 mu m ranges is generally more than 0.1, is preferably more than 0.5, more preferably more than 0.8; Further be preferably more than 0.85, most preferably be more than 0.9.When circularity was big, the high current density charge-discharge characteristic improved, and is therefore preferred.
(8) real density
The real density of native graphite class carbonaceous is generally 2.0g/cm 3More than, be preferably 2.1g/cm 3More than, 2.2g/cm more preferably 3More than, further be preferably 2.22g/cm 3More than, be limited to 2.26g/cm on it 3Below.On be limited to the theoretical value of graphite.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.
(9) tap density
The tap density of native graphite class carbonaceous is generally 0.1g/cm 3More than, be preferably 0.5g/cm 3More than, 0.7g/cm more preferably 3More than, be preferably 0.9g/cm especially 3More than.In addition, be preferably 2.0g/cm 3Below, 1.8g/cm more preferably 3Below, be preferably 1.6g/cm especially 3Below.If tap density is lower than this scope, then when using as negative pole, packed density is difficult to improve, and can not obtain the battery of high power capacity sometimes.On the other hand, if be higher than this scope, then the interparticle space in the electrode is very few, is difficult to guarantee interparticle conductivity, is difficult to obtain preferred battery behavior sometimes.
(10) orientation ratio (powder)
The orientation ratio of native graphite class carbonaceous is generally more than 0.005, is preferably more than 0.01, and more preferably more than 0.015, the upper limit is the scope below 0.67 in theory.If be lower than this scope, then the high density charge-discharge characteristic reduces sometimes.
(11) draw ratio (powder)
The draw ratio of native graphite class carbonaceous is that the upper limit is generally below 10 more than 1 in theory, is preferably below 8, more preferably below 5.If surpass its upper limit, striped can be produced when processing pole plate, uniform coated face can't be obtained, the high current density charge-discharge characteristic reduces sometimes.
[[raw material of carbonaceous material (C)]]
As the raw material of the carbonaceous material (C) that contains in the different orientation carbon complex of the present invention, so long as material that can carbonization gets final product, not special the qualification can not enumerated aromatic hydrocarbons such as asphalt stock, acenaphthylene, decacyclene, anthracene, phenanthrene; N such as azophenlyene, acridine cycle compound; S cycle compounds such as thiophene, di-thiophene; Polyphenyl such as biphenyl, terphenyl; Polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral resin, they do not dissolve organic polymers such as handled thing, nitrogenous polyacrylonitrile, polypyrrole; Organic polymers such as the polythiophene of sulfur-bearing, polystyrene; With cellulose, lignin, mannosan, polygalacturonic acid, shitosan, sucrose is the natural polymers such as polysaccharide of representative; Thermoplastic resin such as polyphenylene sulfide, polyphenylene oxide; Thermosetting resins such as furfuryl alcohol resin, phenolic resins, imide resin; The organic substances such as solution that perhaps they are dissolved in the small molecular organic solvents such as benzene,toluene,xylene, quinoline, n-hexane and form; But the gas of carbonization etc.
In the middle of these,, can make the high material of yield, so preferred because the carbon yield of asphalt stock is high.In addition, in this specification, " asphalt stock " is pitch and the material that belongs to pitch, is meant and can carries out carbonization and/or graphited material through proper process.As the example of concrete asphalt stock, can use tar, heavy oil or pitch etc.As the object lesson of tar, can enumerate coal tar, petroleum-type tar etc.As the object lesson of heavy oil, the contact that can enumerate petroleum-type heavy oil decomposes that oil, thermal decomposition are oily, atmospheric resids, decompression residual oil etc.In addition, as the object lesson of pitch, can enumerate coal tar asphalt, petroleum-type pitch, synthetic asphalts etc.Wherein, the armaticity of coal tar asphalt is high, so preferred.These asphalt stocks can use any one separately, also can use more than 2 kinds with combination in any and ratio combination.
In addition, the not special restriction of the content of the asphalt stock of above-mentioned quinoline non-soluble composition, but the common asphalt stock that uses the 30 following scopes that are in.So-called quinoline non-soluble composition is carbon particle or the atomic little greasy filth etc. of the ultra micro that trace contains in the coal tar, if these materials are too many, then in graphitizing process, significantly hindering crystallinity improves, thereby causes the discharge capacity after the graphitization significantly to reduce.In addition, as the assay method of quinoline non-soluble composition, for example can use the method for stipulating among the JIS K2425.
In addition, as long as do not hinder effect of the present invention, except above-mentioned asphalt stock, can also make up and use various thermosetting resins, thermoplastic resin etc. as raw material.
[[preparation of carbonaceous material (C)]]
For the preparation of carbonaceous material (C), in " manufacturing approach 1 and the manufacturing approach 2 of different orientation carbon complex " of back, narrate.
[[character of carbonaceous material (C)]]
For carbonaceous material (C), preferred satisfy simultaneously below shown in (1)～(4) in any one or multinomial.In addition, definition, the assay method partly put down in writing of their definition, assay method etc. and different orientation carbon complex is identical.
(1) X ray parameter
Carbonaceous material (C) is preferably more than the 0.335nm through the d value (interfloor distance) of the lattice plane (002) that X-ray diffraction that adopt to learn the method for shaking is tried to achieve, and is generally below the 0.345nm, is preferably below the 0.340nm, more preferably below the 0.337nm.In addition, the crystallite size (Lc) of the material with carbon element of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is generally more than the 5nm, is preferably more than the 10nm, more preferably more than the 50nm, further is preferably the above scope of 80nm.If be lower than this scope, then crystallinity reduces, and might increase the increase of initial stage irreversible capacity.
(2) ash content
Contained ash content is generally below the 1 quality % with respect to the gross mass of different orientation carbon complex in the carbonaceous material (C), is preferably below the 0.5 quality %, is preferably especially below the 0.1 quality %, and its lower limit is generally more than the 1ppm.If surpass above-mentioned scope, can not ignore sometimes with the reaction of nonaqueous electrolytic solution and the deterioration of the battery performance that causes when then discharging and recharging.If be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
(3) Raman R value, Raman half breadth
Use the Raman R value of the carbonaceous material (C) of argon laser Raman spectroscopy mensuration to be generally more than 0.01, be preferably more than 0.03, more preferably more than 0.05, its upper limit is generally below 0.60, is preferably the scope below 0.30.If Raman R value is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of nonaqueous electrolytic solution, causes the gas of efficient reduction or generation to increase sometimes.
In addition, carbonaceous material of the present invention (C) is at 1580cm -1Near Raman half breadth has no particular limits, and is generally 5cm -1More than, preferred 10cm -1More than, in addition, its upper limit is generally 60cm -1Below, be preferably 45cm -1Below, 30cm more preferably -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.On the other hand, if be higher than this scope, then the crystallinity of particle surface reduces, with the reactivity increase of nonaqueous electrolytic solution, and the gas increase that causes efficient to reduce sometimes or produce.
(4) real density
The real density of carbonaceous material (C) is generally 2.0g/cm 3More than, be preferably 2.2g/cm 3More than, 2.22g/cm more preferably 3More than, be limited to the theoretical upper limit 2.26g/cm of graphite on it 3Below.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.
[manufacturing approach of the different orientation carbon complex of negative pole [5]]
As manufacturing approach, not special the qualification only otherwise exceed the scope of main idea of the present invention, just can be used any method, preferably the summary of example such as following (1), (2).
(1) initial feed of carbonaceous material (C) in any one operation its all or part of all form liquid state, and become liquid state with this and mix with native graphite (D) and/or mediate;
(2) compound that obtains in this operation is carried out devolatilization composition/sintering, graphitization, pulverize again, classification adjusts granularity.Can also be between these operations through the pulverizing once/classification operation.
The concrete example of above-mentioned summary is shown below.
[[manufacturing approach 1 of different orientation carbon complex]]
Compoundization of carbonaceous material (C) that different orientation carbon complex preferred natural graphite class carbonaceous material (B) among the present invention is different with native graphite class carbonaceous material (B) with orientation; As an example; Method can be listed below: in above-mentioned native graphite (D) with the mixed of regulation as the asphalt stock of the precursor of above-mentioned carbonaceous material (C) or material that asphalt stock etc. is heat-treated and pulverized and obtains (below; Abbreviate " heat treatment graphite crystallization precursor " as), natural polymer etc.; Pulverize again after heat-treating A, heat-treat the method for B (sintering, graphitization) etc. then.In addition, if there is no need to make median particle diameter fully little, also can not carry out above-mentioned pulverizing.
[[[manufacturing of heat treatment graphite crystallization precursor]]]
In advance asphalt stock is implemented heat treatment, obtain heat treatment graphite crystallization precursor.The heat treatment that this is prior is called pitch heat treatment.After this heat treatment graphite crystallization precursor pulverizing, (D) mixes with native graphite, heat-treats A then; At this moment, the part or all of fusion of one of which, here; Can adjust the content of volatile ingredient through prior heat treatment (pitch heat treatment), come suitably to control its molten condition thus.In addition, as the volatile ingredient that contains in the heat treatment graphite crystallization precursor, can enumerate hydrogen, benzene, naphthalene, anthracene, pyrene etc. usually.
The not special restriction of temperature conditions during pitch heat treatment is generally 300 ℃～550 ℃ scope.If heat treated temperature is lower than this scope, then volatile ingredient becomes many, therefore is difficult to sometimes in air, pulverize safely.On the other hand; If surpass its upper limit; Then when heat-treating A, the part of heat treatment graphite crystallization precursor or all can fusion is difficult to obtain the particle (different orientation carbon complex) of bluk recombinationization before native graphite class carbonaceous material (B) and the heat treatment graphite crystallization sometimes.When carrying out pitch heat treatment, carrying out under the non-active gas atmosphere such as nitrogen or under the volatile ingredient atmosphere that produces by asphalt stock.
The device that uses during as pitch heat treatment, not special restriction for example can be used reactors such as shuttle-type stove, tunnel furnace, electric furnace, autoclave, coka (コ one カ one) (heat treatment groove that cokes (コ one Network ス) makes) etc.When carrying out pitch heat treatment, can stir as required.
In addition, as heat treatment graphite crystallization precursor, preferably use the volatile ingredient containing ratio to be generally the above material of 5 quality %.Through using the volatile ingredient containing ratio is the graphite crystallization precursor of this scope, makes native graphite class carbonaceous material (B) and compoundization of carbonaceous material (C) through heat treatment A, thus the different orientation carbon complex that can obtain having the afore mentioned rules rerum natura.
At first; For in advance asphalt stock being implemented heat treatment; Thereby make middle phase (バ Le Network メ ソ Off エ one ズ of body as the precursor of graphite crystallization; Bulk mesophase) method of (the graphite crystallization precursor of heat-treating in advance, brief note is " heat treatment graphite crystallization precursor " below) describes.
(volatile ingredient of heat treatment graphite crystallization precursor)
The not special restriction of the volatile ingredient of the graphite crystallization precursor that obtains through pitch heat treatment, but be generally more than the 5 quality %, be preferably more than the 6 quality %, in addition, be generally below the 20 quality %, be preferably below the 15 quality %.If volatile ingredient is lower than above-mentioned scope; Then because volatile ingredient is many; Therefore be difficult to sometimes in air, pulverize safely, and if surpass its upper limit, then when heat-treating A; The part of graphite crystallization precursor or all can fusion is difficult to obtain the particle (different orientation carbon complex) of bluk recombinationization before native graphite class carbonaceous material (B) and the heat treatment graphite crystallization sometimes.In addition, as the assay method of volatile ingredient, for example use the method for stipulating among the JIS M8812.
(softening point of heat treatment graphite crystallization precursor)
The not special restriction of the softening point of the graphite crystallization precursor that obtains through pitch heat treatment, but be generally more than 250 ℃, be preferably more than 300 ℃; More preferably more than 370 ℃, in addition, be generally below 470 ℃; Be preferably below 450 ℃, more preferably the scope below 430 ℃.If be lower than lower limit; Then the carbonization yield of the graphite crystallization precursor after the heat treatment is low; The uniform mixture that is difficult to acquisition and native graphite class carbonaceous material (B) is if surpass the upper limit, then when heat-treating A; The part of graphite crystallization precursor or all can fusion is difficult to obtain the particle (different orientation carbon complex) of bluk recombinationization before native graphite class carbonaceous material (B) and the heat treatment graphite crystallization sometimes.
As softening point; Use the following value of measuring: (for example use the thermo-mechanical analysis device; The TMA4000 that bruke-axs (Block Le カ one エ イ エ Star Network ス) Co., Ltd. makes); In nitrogen circulation down, 10 ℃/minute of programming rates, needlepoint form 1mm φ, increase the weight of under the condition of 20gf, employing through-transmission technique (ペ ネ ト レ one シ ヨ Application method) is measured be shaped to the thick test portion of 1mm with the tablet former.
(pulverizing of heat treatment graphite crystallization precursor)
Then, will pulverize through the heat treatment graphite crystallization precursor that pitch heat treatment obtains.This is because through heat treatment, with big unit and be arranged in the crystallization miniaturization of the heat treatment graphite crystallization precursor on the same direction, and/or carry out mixing, compoundization of native graphite (D) and heat treatment graphite crystallization precursor equably.
The not special restriction of the pulverizing of the graphite crystallization precursor that obtains through pitch heat treatment; But the granularity of the heat treatment graphite crystallization precursor after pulverizing is generally more than the 1 μ m, is preferably more than the 5 μ m, and is generally below the 10mm; Be preferably below the 5mm; More preferably below the 500 μ m, be preferably especially below the 200 μ m, further be preferably below the 50 μ m.When above-mentioned granularity is lower than 1 μ m, because the surface of heat treated heat treatment graphite crystallization precursor contacts and oxidation with air, hinder the crystalline raising in the graphitizing process in pulverizing or after pulverizing, cause the reduction of graphitization discharge capacity afterwards sometimes.On the other hand, if above-mentioned granularity surpasses 10mm, then weaken owing to pulverizing the micronized effect that brings; Crystallization is orientated easily; Carbonaceous material (C) is orientation easily, uses the active material orientation ratio step-down of the electrode of different orientation carbonaceous compound (A), and the electrode when being difficult to suppress the electrode charging expands.And/or, therefore being difficult to even mixing because the particle diameter difference of native graphite (D) and heat treatment graphite crystallization precursor becomes big, it is inhomogeneous that compoundization becomes sometimes easily.
The device that is used to pulverize has no particular limits, and for example, as Roughpulverizer, can enumerate shearing mill, jaw crusher, impact type crushing machine, cone crusher etc.; As middle pulverizer, can enumerate roll crusher, beater grinder etc.; As atomizer, can enumerate ball milling, vibration milling, pin rod pulverizer, stir mill, jet mill, turbine mill (turbomill) etc.
[[[heat treatment of native graphite (D) and heat treatment graphite crystallization precursor]]]
With native graphite (D) and the mixed of heat treatment graphite crystallization precursor (raw material of carbonaceous material (C)), and heat-treat A, pulverizing, heat treatment B (sintering, graphitization), make different orientation carbon complex thus to stipulate.
(mixing of native graphite (D) and heat treatment graphite crystallization precursor)
The not special restriction of the native graphite (D) that before heat treatment A, carries out and the mixed proportion of heat treatment graphite crystallization precursor; Native graphite (D) is generally more than the 20 quality % with respect to the ratio of mixture; Be preferably more than the 30 quality %, more preferably more than the 40 quality %, in addition; Be generally below the 95 quality %, be preferably below the 90 quality %.If be lower than its lower limit; Then because the increase of the ratio of the carbonaceous material (C) in the different orientation carbon complex (A); When processing electrode, be difficult to improve packed density, need excessive compacting loading, can not obtain effect sometimes compoundization of native graphite class carbonaceous material (B).If surpass its upper limit, native graphite class carbonaceous material (B) surface in the then different orientation carbon complex (A) expose increase, the specific area of different orientation carbon complex (A) has the possibility that becomes big, and is not preferred sometimes on powder property.
When native graphite (D) and the heat treatment graphite crystallization precursor that is adjusted into designated size are mixed; Do not limit the device that uses is special, for example can enumerate V-Mixer, Wtypeofblender, container changeable type mixer, mixing roll, cylinder mixer, shearing blender etc.
(heat treatment A)
Then, the mixture of native graphite (D) and heat treatment graphite crystallization precursor is implemented heat treatment A.This is because through heat treatment graphite crystallization precursor fusion or the fusion again after will pulverizing, the heat treatment graphite crystallization precursor particles after native graphite (D) and the miniaturization contacts and immobilization with no state of orientation.Thus, the mixture of native graphite (D) and heat treatment graphite crystallization precursor is not only the mixture of particle, also can process the mixture (following suitably be called " graphite compound mixture ") of more uniform compoundization.
The not special restriction of the temperature conditions of heat treatment A, but be generally more than 300 ℃, be preferably more than 400 ℃, more preferably more than 450 ℃, in addition, be generally below 650 ℃, be preferably below 600 ℃.If the temperature of heat treatment A is lower than above-mentioned scope, then therefore remaining a large amount of volatile ingredients in the material after heat treatment A might cause powder fusion each other when sintering or graphitization process, must pulverize sometimes again.On the other hand, if surpass above-mentioned scope, then the composition of fusion separates into needle-like when pulverizing again, causes the reduction of tap density sometimes.Heat treatment A is carrying out under the non-active gas atmosphere such as nitrogen or under the volatile ingredient atmosphere of the heat treatment graphite crystallization precursor of the miniaturization by pulverizing generation.
The not special restriction of the device that heat treatment A uses for example can be used shuttle-type stove, tunnel furnace, electric furnace etc.
(pulverizing of heat treatment graphite crystallization precursor and the replacement of heat treatment A are handled)
; Replacement as above-mentioned pulverizing and heat treatment A is handled; It can be the processing of organizing miniaturization, nothing orientationization that can make heat treatment graphite crystallization precursor; For example, the processing of can be on one side giving mechanical energy in the fusion of heat treated graphite crystallization precursor or softening temperature province, with native graphite (D) mix and heat-treat on one side.
Replace the heat treatment of processing as this, not special restriction, but usually more than 200 ℃, preferably more than 250 ℃, and usually below 450 ℃, preferably carrying out below 400 ℃.If temperature conditions is lower than above-mentioned scope, the fusion of the graphite crystallization precursor in then replacing handling, softening insufficient is difficult to carry out compoundization with native graphite (D) sometimes.In addition, if surpass above-mentioned scope, then heat treatment is carried out easily rapidly, and the separate particles of carbonaceous heat treatment graphite crystallization precursor etc. becomes needle-like when pulverizing, and causes the reduction of tap density sometimes easily.
This replacement is handled usually and under inactive atmospheres such as nitrogen, perhaps under oxidizability atmosphere such as air, is carried out.But, when under the oxidizability atmosphere, handling, after graphitization, be difficult to obtain high crystalline sometimes, therefore be necessary to make not melting that oxygen causes excessively not carry out.Particularly, the oxygen amount in the graphite crystallization precursor after replacing handling is generally below the 8 quality %, is preferably below the 5 quality %.
In addition, the not special restriction of the device that uses when replacing handling for example can be used blender, kneader etc.
(pulverizing)
The graphite compound mixture that then, will carry out heat treatment A is pulverized.This is because with compoundization of native graphite (D), reach target grain size with the piece of graphite compound mixture of organizing miniaturization, not having state fusion or a fusion of orientationization through pulverizing through heat treatment A.
The not special restriction of the granularity of the graphite compound mixture after the pulverizing, but be generally more than the 1 μ m, be preferably more than the 3 μ m; More preferably more than the 5 μ m, further be preferably more than the 7 μ m, in addition; Be generally below the 50 μ m, be preferably below 35, more preferably below the 30 μ m.If granularity is lower than above-mentioned scope, then the tap density as different orientation carbonaceous compound (A) diminishes, and therefore when processing electrode, is difficult to improve the packed density of active material, is difficult to obtain the battery of high power capacity.On the other hand,, then be coated with when making electrode, be easy to generate crawling sometimes in form with different orientation carbonaceous compound (A) if surpass above-mentioned scope.
For the not special restriction of the device that is used for pulverizing, for example,, can enumerate jaw crusher, impact type crushing machine, cone crusher etc. as Roughpulverizer; As middle pulverizer, can enumerate roll crusher, beater grinder etc.; As atomizer, can enumerate ball milling, vibration milling, pin rod pulverizer, stir mill, jet mill etc.
(heat treatment B: sintering)
Heat treatment B is meant sintering and graphitization.Below, begin explanation from sintering.But, also can omit sintering.To carry out sintering through the graphite compound mixture that pulverizing is pulverized.This be because, the fusion of graphite compound mixture when suppressing graphitization, and remove the volatile ingredient of graphite compound mixture through sintering.
The not special restriction of temperature conditions when carrying out sintering, but be generally more than 600 ℃ is preferably more than 1000 ℃, and the upper limit is generally below 2400 ℃, is preferably below 1300 ℃.If temperature conditions is lower than above-mentioned scope, then when graphitization, cause the fusion of graphite compound mixture powder sometimes easily.On the other hand, if surpass above-mentioned scope, then agglomerating plant needs expense, therefore in the scope of said temperature condition, carries out usually.
Sintering is carrying out under the inactive atmospheres such as nitrogen or under the non-oxidizable atmosphere that the gas that is produced by the graphite compound mixture after pulverizing again forms.In addition, in order to simplify manufacturing process, can not carry out sintering circuit yet and directly carry out graphitization.
As the device that is used for sintering, not special restriction for example can be used shuttle-type stove, tunnel furnace, electric furnace, coke baking furnace, rotary furnace etc.
(heat treatment B: graphitization)
Then, the graphite compound mixture that carries out oversintering is implemented graphitization.This is because increase the discharge capacity in the cell evaluation, and improve crystallinity.Through graphitization, can obtain different orientation carbonaceous compound (A).
The not special restriction of temperature conditions when carrying out graphitization, but be generally more than 2800 ℃ is preferably more than 2900 ℃, more preferably more than 3000 ℃, and is generally below 3400 ℃, is preferably below 3200 ℃.If surpass above-mentioned scope, then the reversible capacity of battery diminishes sometimes, is difficult to make the battery of high power capacity sometimes.In addition, if surpass above-mentioned scope, then the distillation amount of graphite becomes many easily sometimes.
Carry out under the non-oxidizable atmosphere that the gas that graphitization produces at the graphite compound mixture of perhaps being crossed by sintering under the inactive atmospheres such as argon gas forms.As the employed device of graphitization, not special restriction for example can be enumerated direct energising stove, acheson furnace, as the resistance-heated furnace of energized indirectly, induction heater etc.
In addition, when graphitization processing or the operation before it, promptly from the operation that is heat-treated to sintering, can also be in material (native graphite (D), asphalt stock or graphite crystallization precursor) or the surface graphitization catalyst of adding Si, B etc.
(other processing)
In addition, as long as do not hinder effect of the present invention, each handles, can also carry out various processing such as hierarchical processing except above-mentioned.Hierarchical processing is to be target grain size in order to make the granularity after the graphitization processing, and removes corase meal and micropowder.
As the device as hierarchical processing, not special restriction for example, under the situation of dry type screening, can be used gyratory sifter, rock type sieve, rotary type sieve, oscillatory type sieve etc.; Under the situation of dry type air current classifying, can use gravity type grader, inertia force formula grader, centrifugal force type grader (sizer, cyclone separator) etc.; Wet screening can use mechanical type wet classifier, hydraulic classifier, settling classifier, centrifugal wet classifier etc.
Hierarchical processing can be proceeded after the pulverizing behind the heat treatment A immediately, also can after the sintering after for example pulverizing, perhaps carry out after the graphitization at other times.In addition, can also omit hierarchical processing itself.But, from this point of BET specific area that reduces different orientation carbonaceous compound (A), and productivity this put, preferably proceed immediately after the pulverizing behind heat treatment A.
(processing after the manufacturing of different orientation carbonaceous compound (A))
For the BET specific area of controlling negative material, improve the electrode briquettability, improve discharge capacity and cheap etc., can also add Delanium powder or the native graphite powder of making separately to the different orientation carbonaceous compound made from above-mentioned sequential system (A) and mix.
[manufacturing approach 2 of the different orientation carbon complex of negative pole [5]]
Different orientation carbon complex can be made according to the methods below.The carbonaceous material (C) that different orientation carbon complex preferred natural graphite class carbonaceous material (B) among the present invention is different with native graphite class carbonaceous material (B) with orientation carry out compoundization; As an example; Method can be listed below: in above-mentioned native graphite (D), will make through the operation of " mediating (mixing) ", " moulding ", " sintering ", " graphitization ", " pulverizing " as the asphalt stock of the precursor of above-mentioned carbonaceous material (C) etc.But in these operations, " moulding ", " sintering ", " pulverizing " can be omitted and/or implemented simultaneously with other operations.Particularly, can be through the following acquisitions of enumerating such as manufacturing approach.
[[mediating (mixing)]]
The mixing of the raw materials such as graphitization catalyst that carry out native graphite (D), asphalt stock and add according to hope.At this moment, for even mixing, preferably heat.Thus, become at native graphite (D) and mediate the state that adds liquid asphalt stock in the raw material of not fusion under the temperature.At this moment; Can in kneader, add all raw materials mediates simultaneously and heats up; The asphalt stock of also can in kneader, packing into composition and heating under stirring in addition after temperature rises to and mediates temperature, adds the asphalt stock of normal temperature or sulfuration molten condition again.
Heating-up temperature usually more than the softening point of asphalt stock, preferably in high temperature more than 10 ℃ than softening point, more preferably than softening point high temperature range more than 20 ℃ carry out.In addition, the upper limit is generally below 300 ℃, is preferably the scope below 250 ℃.If be lower than this scope, then the viscosity of asphalt stock uprises, and is mixed with the difficulty that possibly become.On the other hand, if surpass this scope, then owing to volatilize and polycondensation, it is too high that the viscosity of mixed system becomes sometimes.
Mixer preferably has the machine of agitator, and agitator can use Z type, the so general agitator of マ チ ス ケ one タ type.The amount of putting into the raw material in the mixer is generally more than the 10 volume % of mixer volume, is preferably more than the 15 volume %, and is below the 50 volume %, is preferably below the 30 volume %.Incorporation time was necessary for more than 5 minutes, the longest time for bringing tangible viscosity change up to the volatilization owing to volatile ingredient, was generally 30～120 minutes.Mixer preferably was preheating to the kneading temperature before mixing.
[[moulding]]
The mixture that obtains can directly offer the devolatilization composition/sintering circuit that is used to remove volatile ingredient and carbonization, but for easy operation, preferably after moulding, offers devolatilization composition/sintering circuit again.
As long as can keep shape, the then not special restriction of forming method can be adopted extrusion molding, mould molding, hydrostatic pressing moulding etc.Wherein, Preferred extrusion molding or mould molding because extrusion molding particle in formed body is orientated easily, though and the mould molding particle orientation keeps random; But in view of productivity; Operate easily than hydrostatic pressing moulding, in addition, when mixing, can not make randomly-oriented structural deterioration and obtain formed body.
Forming temperature can be any of room temperature (low temperature), heating following (temperature that the softening point of high temperature, asphalt stock is above).At low temperatures during moulding, in order to improve mouldability and to obtain the homogeneity of formed body, hope will be mediated the mixture coarse crushing in advance of back cooling to full-size 1mm.The shape of formed body, size do not have special restriction, but when thermoforming, if formed body is excessive, then before moulding, carrying out uniform preheating needs the time, and therefore, preferred maximum dimension is a size following about 150cm usually.
If the pressure of briquetting pressure is too high, then the volatile ingredient of the micropore through formed body remove the difficulty that becomes, and be not that the native graphite (D) of proper circle is orientated, the difficulty that becomes of the pulverizing in the subsequent handling, so the upper limit of briquetting pressure is generally 3000kgf/cm 2(294MPa), be preferably 500kgf/cm 2(49MPa), 10kgf/cm more preferably 2(0.98MPa).The not special restriction of the pressure of lower limit, but be preferably set at the degree that can keep the shape of formed body in devolatilization composition/sintering circuit.
[[devolatilization composition/sintering]]
In order to remove the volatile ingredient of native graphite (D) and asphalt stock, and pollution, the filler of the filler when preventing graphitization are bonding to formed body, and the formed body that obtains is carried out devolatilization composition/sintering.Devolatilization composition/sintering is usually more than 600 ℃, preferably more than 650 ℃, and usually below 1300 ℃, preferably carried out 0.1 hour～10 hours in the temperature below 1100 ℃.For anti-oxidation, heat in the non-oxidizable atmosphere that under the circulation of non-active gas such as nitrogen, argon or in the gap, is filled with breeze (breeze), filling coke (Packing coke) equigranular material with carbon element usually and carry out.
The equipment that uses in devolatilization composition/sintering is so long as electric furnace or gas burner, electrode material can get final product by the equipment of sintering not special the qualification with coke baking furnace etc. in non-oxidizable atmosphere.In order to remove volatile ingredient, the programming rate during heating is preferably low speed, usually is warmed up near 700 ℃ that only produce hydrogen with 3～100 ℃/hour begin to volatilize from low boiling point component about 200 ℃.
[[graphitization]]
The carbide formed body that obtains through devolatilization composition/sintering then heating at high temperature carries out graphitization.For graphited condition, identical with manufacturing approach 1 record.
For anti-oxidation, graphitization is carried out under the non-oxidizable atmosphere that perhaps in the gap, is filled with breeze, filling coke equigranular material with carbon element under the circulation of non-active gas such as nitrogen, argon.The equipment that uses in the graphitization is so long as electric furnace or gas burner, electrode material can realize that with acheson furnace etc. the equipment of above-mentioned purpose gets final product; Not special the qualification, programming rate, cooling rate, heat treatment time etc. can be set arbitrarily in the scope of using that equipment allowed.
[[pulverizing]]
The graphitization processing thing that obtains like this is normally block, is difficult to use as negative electrode active material, therefore pulverizes and/or the removing of big particle diameter shape material, small particle diameter material.The not special restriction of the breaking method of graphitization processing thing, the reducing mechanism that as reducing mechanism, the device that machinery grinds for example can enumerate ball milling, beater grinder, CF mill, atomizer mill, pulverizer (pulverize), utilize wind-force be jet mill etc. for example.For coarse crushing, the middle pulverizing, can use jaw crusher, hammer crusher, edge runner etc. to utilize the grinding mode of impulsive force.Here, the pulverizing time can be before the graphitization, also can be after the graphitization.
[auxiliary material of negative pole [5] mixes]
Except that above-mentioned different orientation carbon complex; Through in the negative electrode active material of lithium secondary battery of the present invention, contain more than one with above-mentioned different orientation carbon complex in carbonaceous material (carbonaceous material) different aspect the rerum natura of carbonaceous, can further seek the raising of battery performance.Here said " rerum natura of carbonaceous " is meant more than one characteristic of X-ray diffraction parameter, median particle diameter, draw ratio, BET specific area, orientation ratio, Raman R value, tap density, real density, micropore distribution, circularity, ash amount.In addition,, can enumerate as preferred embodiment, asymmetric about when the volume reference particle size distribution is the center with the median particle diameter, to contain Raman R value is different more than 2 kinds material with carbon element or X ray parameter not equal.As an example of its effect, can enumerate through containing graphite such as native graphite, Delanium; Carbon blacks such as acetylene black; Material with carbon elements such as amorphous carbon such as needle coke reduce resistance etc. as auxiliary material.They can use a kind of separately, also can use more than 2 kinds with combination in any and arbitrary proportion combination.When adding as auxiliary material; Its addition is generally more than the 0.1 quality %, is preferably more than the 0.5 quality %, more preferably more than the 0.6 quality %; Its upper limit is generally below the 80 quality %; Be preferably below the 50 quality %, more preferably below the 40 quality %, further be preferably the scope below the 30 quality %.If be lower than this scope, then be difficult to obtain the effect that conductivity improves sometimes.If surpass above-mentioned scope, then cause the increase of initial stage irreversible capacity sometimes.
[making the electrode of negative pole [5]]
Make negative pole and can adopt usual way, can with the above-mentioned negative pole [5] that likewise forms.The ratio of the thickness of collector body, collector body and active material layer, electrode density, adhesive, pole plate orientation ratio, impedance etc. are also same as described above.
< negative pole [6] >
Below; Negative pole [6] to using in the lithium secondary battery of the present invention describes; This negative pole contains graphite matter carbon particle as negative electrode active material; The circularity of said graphite matter carbon particle is more than 0.85, and the interplanar distance (d002) of (002) face of measuring through wide-angle x-ray diffraction is lower than 0.337nm, adopt that the argon laser Raman spectroscopy measures with 1360cm -1Peak intensity with respect to 1580cm -1The Raman R value of ratio definition of peak intensity be 0.12～0.8.
[negative electrode active material of negative pole [6]]
Below, the negative electrode active material that uses in the anticathode [6] describes.
The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [6] contains satisfied following (a) and (b) and graphite matter carbon particle (c) at least.
(a) circularity is more than 0.85;
(b) interplanar distance (d002) of (002) face of wide-angle x-ray diffraction mensuration is lower than 0.337nm;
(c) adopt that the argon laser Raman spectroscopy measures with 1360cm -1Peak intensity with respect to 1580cm -1The Raman R value (below, only brief note is " a Raman R value " sometimes) of ratio definition of peak intensity be 0.12～0.8.
[[circularity]]
The circularity of the graphite matter carbon particle that uses as the negative electrode active material of lithium secondary battery of the present invention is generally more than 0.85, is preferably more than 0.87, more preferably more than 0.89, is preferably more than 0.92 especially.As the upper limit, circularity is 1 o'clock, is theoretical proper sphere.If circularity is lower than this scope, then the fillibility of negative electrode active material reduces, and heat conductivity reduces, and therefore the early stage output of overslaugh sometimes recovers, and particularly, the recovery of the output of the low output state during by low temperature is slack-off sometimes.
Said circularity defines with following formula among the present invention.
Circularity=(having girth)/(perimeter of particle projection of shape) with particle projection of shape equivalent circular of the same area
Use the following value of measuring as the value of circularity: (for example use flow-type particle picture analytical equipment; The FPIA of Sysmex Industrial manufactured); About 0.2g sample is scattered in the 0.2 quality % aqueous solution (about 50mL) of polyoxyethylene (20) Span-20 as surfactant; Behind the ultrasonic wave with 1 minute 28kHz of the power output of 60W irradiation, specifying 0.6～400 μ m is detection range, and the particle of particle diameter 3～40 mu m ranges is measured.
[[interplanar distance (d002)]]
The graphite matter carbon particle that uses as the negative electrode active material of negative pole [6] in the lithium secondary battery of the present invention adopts the interplanar distance (d002) of (002) face that wide-angle x-ray diffraction measures to be lower than 0.337nm, is preferably below the 0.336nm.As lower limit, be the theoretical value 0.335 of graphite.If surpass this scope, then crystallinity reduces, and the heat conductivity that is caused by electronics reduces, and early stage output recovery characteristics reduces sometimes, and particularly, the recovery of the output of the low output state during by low temperature is slack-off sometimes.
The interplanar distance (d002) of (002) face that said employing wide-angle x-ray diffraction is measured among the present invention is through adopting the d value (interfloor distance) of the lattice plane (002 face) that the X-ray diffraction of learning the method for shaking tries to achieve.
In addition, not special qualification of crystallite size (Lc) of the graphite matter material with carbon element of trying to achieve through X-ray diffraction that adopt to learn the method for shaking, but be generally more than the 10nm, be preferably more than the 30nm, more preferably the above scope of 80nm.If be lower than this scope, then crystallinity reduces, and the heat conductivity that is caused by electronics reduces, and early stage output recovery characteristics reduces sometimes.
[[Raman R value]]
The Raman R value of the graphite matter carbon particle that uses as the negative electrode active material of negative pole [6] in the lithium secondary battery of the present invention is necessary for more than 0.12, is preferably more than 0.15, more preferably more than 0.17, is preferably more than 0.2 especially.Its upper limit is preferably below 0.8, more preferably below 0.6, is preferably below 0.45 especially.If Raman R value is lower than this scope, then the crystallinity of particle surface is too high, and along with the minimizing that discharges and recharges the site, output reduces sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and the heat conduction that is caused by electronics reduces, and the recovery characteristics of output reduces sometimes.
The mensuration of Raman spectrum is carried out as follows: use raman spectroscopy device (the raman spectroscopy device that for example Japanese beam split society makes); Sample is fallen naturally and be filled in the cell; To the specimen surface in pond irradiation argon laser, simultaneously, make the pond with the face of laser vertical in rotate.For the Raman spectrum that obtains, measure 1580cm -1Near peak P AIntensity I AAnd 1360cm -1Near peak P BIntensity I B, calculate its strength ratio R (R=I B/ I A), it is defined as the Raman R value of graphite matter material with carbon element.In addition, measure the Raman spectrum obtain at 1580cm -1Near peak P AHalf breadth, it is defined as the Raman half breadth of graphite matter material with carbon element.
In addition, the Raman condition determination here is following.
Argon laser wavelength: 514.5nm
Laser power on the sample: 15～25mW
Resolution: 10～20cm -1
Measurement range: 1100cm -1～1730cm -1
Raman R value, half breadth analysis: background is handled
Smooth treatment: simple average, convolution 5 points
The graphite matter carbon particle that uses as the negative electrode active material of negative pole [6] in the lithium secondary battery of the present invention is at 1580cm -1Near Raman half breadth has no particular limits, but is generally 10cm -1More than, be preferably 15cm -1More than, in addition, its upper limit is generally 60cm -1Below, be preferably 50cm -1Below, 45cm more preferably -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, and along with the minimizing that discharges and recharges the site, output reduces sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and the heat conduction that is caused by electronics reduces, and the recovery characteristics of output reduces sometimes.
[[tap density]]
The tap density of the graphite matter carbon particle that uses as the negative electrode active material of negative pole [6] in the lithium secondary battery of the present invention is generally 0.55g/cm 3More than, be preferably 0.7g/cm 3More than, 0.8g/cm more preferably 3More than, be preferably 1g/cm especially 3More than.In addition, the upper limit is preferably 2g/cm 3Below, 1.8g/cm more preferably 3Below, be preferably 1.6g/cm especially 3Below.If tap density is lower than this scope, then when using as negative pole, packed density is difficult to improve, and interparticle contact area reduces, so heat conductivity reduces sometimes.On the other hand, if surpass this scope, then the interparticle space in the electrode is very few, and the stream of nonaqueous electrolytic solution reduces, so output itself reduces sometimes.
In the present invention, tap density is as giving a definition: make sample drop on 20cm through the sieve of aperture 300 μ m 3The jolt ramming container in; Be full of the upper surface of container up to sample after; Use powder density determination device (for example, the Tap densor that seishin enterprise-like corporation makes) to carry out the vibration of 1000 length of stroke 10mm, the density that the volume with thus time the and the weight of sample are tried to achieve is defined as tap density.
[[BET specific area]]
The specific area of the graphite matter carbon particle that the negative electrode active material of negative pole [6] uses in the conduct lithium secondary battery of the present invention that use BET method is measured is preferably 0.1m 2More than/the g, 0.7m more preferably 2More than/the g, be preferably 1m especially 2More than/the g, further be preferably 1.5m 2More than/the g.Its upper limit is preferably 100m 2Below/the g, 50m more preferably 2Below/the g, be preferably 25m especially 2Below/the g, further be preferably 15m 2Below/the g.If the value of BET specific area is lower than this scope, when then using as negative material, the easy variation of acceptance of lithium when charging, lithium is separated out at electrode surface sometimes easily.On the other hand, if be higher than above-mentioned scope, during then as negative material, with the reactivity increase of nonaqueous electrolytic solution, it is many that the gas of generation becomes easily, is difficult to obtain preferred battery sometimes.
The BET specific area is defined as the value of following mensuration: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation, under 350 ℃ to sample carry out 15 minutes predrying, then; Use nitrogen accurately to be adjusted into 0.3 nitrogen helium gas mixture body, measure through the nitrogen absorption BET1 point method that adopts the gas flow method with respect to atmospheric relative pressure value.
[[volume average particle size]]
The volume average particle size of the graphite matter carbon particle that uses as the negative electrode active material of negative pole [6] in the lithium secondary battery of the present invention is defined as the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method; Be preferably more than the 1 μ m; More preferably more than the 3 μ m; Be preferably especially more than the 5 μ m, further be preferably more than the 7 μ m.In addition, its upper limit is generally below the 50 μ m, be preferably below the 40 μ m, and more preferably below the 30 μ m,, be preferably especially below the 25 μ m.If be lower than above-mentioned scope, then irreversible capacity increases, and causes the loss of initial stage battery capacity sometimes.In addition, if surpass above-mentioned scope, then when processing electrode pad, forming uneven coated face easily, is not preferred sometimes on the battery production process.
[[micropore volume]]
The micropore volume of the graphite matter carbon particle that uses for the negative electrode active material of negative pole [6] in the lithium secondary battery of the present invention; Space in the particle that is equivalent to diameter 0.01 μ m～1 μ m of trying to achieve through mercury porosimeter (mercury penetration method), since the concavo-convex amount that causes that is uneven of particle surface be generally more than the 0.01mL/g; Be preferably more than the 0.05mL/g; More preferably more than the 0.1mL/g; Its upper limit is generally below the 0.6mL/g, is preferably below the 0.4mL/g, more preferably the scope below the 0.3mL/g.If surpass this scope, need a large amount of adhesives when then manufacturing pole plate sometimes.If be lower than this scope, then the high current density charge-discharge characteristic reduces, and, the alleviation effects that the electrode in the time of can not obtaining discharging and recharging sometimes expands and shrinks.
In addition, total micropore volume is preferably more than the 0.1mL/g, and more preferably more than the 0.25mL/g, its upper limit is generally below the 10mL/g, is preferably below the 5mL/g, more preferably the scope below the 2mL/g.If surpass this scope, then when processing substrate, need a large amount of adhesives sometimes.If be lower than this scope, then when processing pole plate, can not obtain the dispersion effect of thickener or binding agent sometimes.
In addition, average micropore diameter is preferably more than the 0.05 μ m, more preferably more than the 0.1 μ m, further is preferably more than the 0.5 μ m, and its upper limit is generally below the 50 μ m, is preferably below the 20 μ m, more preferably the scope below the 10 μ m.If surpass this scope, then need a large amount of adhesives sometimes.If be lower than this scope, then the high current density charge-discharge characteristic reduces sometimes.
As the device that is used for the mercury porosimeter, can use mercury porosimeter (autopore9520; The micrometritics manufactured).The about 0.2g sample of weighing (negative material) is encapsulated into powder with in the container, carries out the degassing in 10 minutes at (below the 50 μ mHg) under room temperature, the vacuum, implements pre-treatment.Then, be decompressed to 4psia (about 28kPa), import mercury, boost to 40000psia (about 280MPa), be depressurized to 25psia (about 170kPa) then from 4psia (about 28kPa) stage shape.Number of stages when boosting is more than 80 stages, in each stage, after 10 seconds equilibration time, measures the mercury amount of being pressed into.Use the Washburn formula to be pressed into opisometer and calculate the micropore distribution from the mercury that obtains like this.In addition, the surface tension of mercury (γ) is 485dyne/cm, and contact angle (φ) is 140 °.Average micropore diameter uses the accumulation micro pore volume to reach 50% o'clock micropore diameter.
[[ash content]]
The ash content of the graphite matter carbon particle that uses as the negative electrode active material of negative pole [6] in the lithium secondary battery of the present invention is preferably below the 1 quality % with respect to the gross mass of graphite matter carbon particle; Be preferably especially below the 0.5 quality %, more preferably below the 0.1 quality %.In addition, its lower limit is preferably more than the 1ppm.If surpass above-mentioned scope, can not ignore sometimes with the reaction of nonaqueous electrolytic solution and the deterioration of the battery performance that causes when then discharging and recharging.On the other hand, if be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
The real density of graphite matter carbon particle is generally 2.0g/cm 3More than, be preferably 2.1g/cm 3More than, 2.2g/cm more preferably 3More than, further be preferably 2.22g/cm 3More than, be limited to 2.26g/cm on it 3Below.On be limited to the theoretical value of graphite.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.In the present invention, real density is defined as the value of measuring through the liquid phase displacement method (hydrometer method) of using butanols.
[[orientation ratio]]
The orientation ratio of the graphite matter carbon particle that uses as the negative electrode active material of negative pole [6] in the lithium secondary battery of the present invention is generally more than 0.005, is preferably more than 0.01, and more preferably more than 0.015, the upper limit is the scope below 0.67 in theory.If be lower than this scope, then the high density charge-discharge characteristic reduces sometimes.
Orientation ratio is measured through X-ray diffraction.Use asymmetric Pearson VII as distribution function, (110) diffraction of the carbon that match obtains through X-ray diffraction and the peak of (004) diffraction carry out the peak and separate, and calculate the integrated intensity at the peak of (110) diffraction and (004) diffraction respectively.Calculate by the ratio that (110) diffraction integral intensity/(004) diffraction integral intensity is represented by the integrated intensity that obtains, this ratio is defined as the active material orientation ratio.
The X-ray diffraction condition determination here is following.In addition, " 2 θ " expression angle of diffraction.
The monochromatic photometer of target: Cu (K alpha ray) graphite
Slit: divergent slit=1 degree receives optical slits=0.1mm, scatter slit=1 degree
Measurement range and step angle/minute
(110) face: 76.5 degree≤2 θ≤78.5 degree 0.01 are spent/3 seconds
(004) face: 53.5 degree≤2 θ≤56.0 degree 0.01 are spent/3 seconds
[[draw ratio]]
The draw ratio of the graphite matter carbon particle that uses as the negative electrode active material of negative pole [6] in the lithium secondary battery of the present invention is more than 1 in theory, on be limited to below 10, be preferably below 8, more preferably below 5.If surpass its upper limit, striped can be produced when processing pole plate, uniform coated face can't be obtained, the high current density charge-discharge characteristic reduces sometimes.
The ratio A/B of the major diameter A of particle and perpendicular minor axis B represented when in addition, draw ratio was with three dimensional viewing.The observation of particle is carried out through the scanning electron microscope that can amplify observation.Selection is fixed on any 50 graphite particles on the end face of the metal of thickness below 50 microns, rotation, tilts to be fixed with the objective table of sample, measures A, the B of these particles respectively, obtains the mean value of A/B.
The graphite matter carbon particle that uses as the negative electrode active material of negative pole [6] in the lithium secondary battery of the present invention can be the natural material of producing, and also can be made material, but preferred graphite matter carbon particle contains native graphite.In addition, natural material of producing or made material also can apply specific processing.In addition, the not special restriction of manufacturing approach (also comprising method for separating) for example, can be used stage division sortings such as screening or air classification to have the graphite matter carbon particle of above-mentioned characteristic and obtains.
In the middle of these, preferred especially graphite matter carbon particle applies the mechanics energy process to the natural carbonaceous particle of producing or made carbonaceous particle to carry out modification and makes.More preferably the carbonaceous particle as the raw material of mechanics energy process contains native graphite.
[[mechanics energy process]]
Below, this mechanics energy process is described.As the carbonaceous particle of the raw material of the object that applies the mechanics energy process, not special the qualification is natural or artificial graphite-like carbonaceous particle, as the carbonaceous particle of graphite precursor etc.These Material Characteristics are as follows.
[[[as the raw material graphite-like carbonaceous particle of mechanics energy process]]]
About the character of raw material graphite-like carbonaceous particle, preferably satisfy simultaneously (1) as follows～(11) each or multinomial.In addition, physical property measurement method or definition, all the situation with above-mentioned graphite matter carbon particle is identical.
(1) X ray parameter
Raw material graphite-like carbonaceous particle is preferably more than the 0.335nm through the d value (interfloor distance) of the lattice plane (002) that X-ray diffraction that adopt to learn the method for shaking is tried to achieve, and its upper limit is generally below the 0.340nm, is preferably below the 0.337nm.In addition, the crystallite size (Lc) of the graphite-like carbonaceous particle of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is generally more than the 30nm, is preferably more than the 50nm, more preferably the above scope of 100nm.If be lower than this scope, then crystallinity reduces, and might increase the increase of initial stage irreversible capacity.
(2) ash content
Contained ash content is below the 1 quality % with respect to the gross mass of graphite-like carbonaceous in the raw material graphite-like carbonaceous particle, is preferably below the 0.5 quality %, is preferably especially below the 0.1 quality %, and its lower limit is generally more than the 1ppm.If surpass above-mentioned scope, can not ignore sometimes with the reaction of nonaqueous electrolytic solution and the deterioration of the battery performance that causes when then discharging and recharging.If be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
(3) volume reference average grain diameter
The volume reference average grain diameter of raw material graphite-like carbonaceous particle is defined as the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method; Be generally more than the 1 μ m; Be preferably more than the 3 μ m, more preferably more than the 5 μ m, further be preferably more than the 7 μ m.In addition, the not special restriction of its upper limit is generally below the 10mm, is preferably below the 1mm, more preferably below the 500 μ m, further is preferably below the 100 μ m, is preferably especially below the 50 μ m.If be lower than above-mentioned scope, then make particle diameter become too small through applying the mechanics energy process, cause irreversible capacity to increase sometimes.In addition, if surpass above-mentioned scope, the device difficult that then applies the mechanics energy process effectively turns round, and causes temporal loss sometimes.
(4) Raman R value, Raman half breadth
Use the Raman R value of the raw material graphite-like carbonaceous particle of argon laser Raman spectroscopy mensuration to be generally more than 0.01, be preferably more than 0.03, more preferably more than 0.1, its upper limit is generally below 0.6, is preferably below 0.4.If Raman R value is lower than this scope, then the crystallinity of particle surface is too high, owing to the increase that applies the Raman value that the mechanics energy process causes; And because crystalline reduction; Along with the site that discharges and recharges Li entering interlayer tails off sometimes, that is, the charging acceptance reduces sometimes.On the other hand,, then the crystallinity of particle surface is further reduced owing to applying the mechanics energy process if surpass this scope, with the reactivity increase of nonaqueous electrolytic solution, the gas increase that causes efficient to reduce sometimes or produce.
In addition, 1580cm -1The Raman half breadth have no particular limits, be generally 10cm -1More than, preferred 15cm -1More than, in addition, its upper limit is generally 50cm -1Below, be preferably 45cm -1Below, 40cm more preferably -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, owing to the increase that applies the Raman value that the mechanics energy process causes; And because crystalline reduction; Along with the site that discharges and recharges Li entering interlayer tails off sometimes, that is, the charging acceptance reduces sometimes.On the other hand,, then the crystallinity of particle surface is further reduced owing to applying the mechanics energy process if be higher than this scope, with the reactivity increase of nonaqueous electrolytic solution, the gas increase that causes efficient to reduce sometimes or produce.
(5) BET specific area
Use the specific area of the raw material graphite-like carbonaceous particle of BET method mensuration to be generally 0.05m 2More than/the g, be preferably 0.2m 2More than/the g, 0.5m more preferably 2More than/the g, be preferably 1m especially 2More than/the g.Its upper limit is generally 50m 2Below/the g, be preferably 25m 2Below/the g, 15m more preferably 2Below/the g, be preferably 10m especially 2Below/the g.If the value of BET specific area is lower than this scope, then the BET specific area is increased owing to applying the mechanics energy process, the easy variation of acceptance of lithium when charging, lithium is separated out at electrode surface easily.On the other hand, if be higher than above-mentioned scope, then the BET specific area is further increased owing to applying the mechanics energy process; During as negative electrode active material; Increase with the reactivity of nonaqueous electrolytic solution, it is many that the gas of generation becomes easily, is difficult to obtain preferred battery sometimes.
(7) circularity
Use the degree of circularity as the sphere of raw material graphite-like carbonaceous particle; The particle diameter of raw material graphite-like carbonaceous particle is that the circularity of the particle of 3～40 mu m ranges is preferably more than 0.1; More preferably more than 0.2; Be preferably especially more than 0.4, further be preferably more than 0.5, most preferably be more than 0.6.If be lower than this scope, even then apply the mechanics energy process, also spheroidization fully not, the high current density charge-discharge characteristic reduces sometimes.
(8) real density
The real density of raw material graphite-like carbonaceous particle is generally 2g/cm 3More than, be preferably 2.1g/cm 3More than, 2.2g/cm more preferably 3More than, further be preferably 2.22g/cm 3More than, be limited to 2.26g/cm on it 3Below.On be limited to the theoretical value of graphite.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.
(9) tap density
The tap density of raw material graphite-like carbonaceous particle is generally 0.05g/cm 3More than, be preferably 0.1g/cm 3More than, 0.2g/cm more preferably 3More than, be preferably 0.5g/cm especially 3More than.In addition, be preferably 2g/cm 3Below, 1.8g/cm more preferably 3Below, be preferably 1.6g/cm especially 3Below.If tap density is lower than this scope, even then apply the mechanics energy process, the raising of tap density is also insufficient, and when using as negative electrode active material, packed density is difficult to improve, and can not obtain the battery of high power capacity sometimes.On the other hand, if be higher than this scope, when then applying the mechanics energy process, tap density further rises, and the interparticle space of processing in the electrode behind the electrode is very few, because the stream of nonaqueous electrolytic solution is not enough, the high current density charge-discharge characteristic might reduce.The tap density of graphite-like carbonaceous particle also adopts method same as described above to measure and definition.
(10) orientation ratio (powder)
The orientation ratio of raw material graphite-like carbonaceous particle is generally more than 0.001, is preferably more than 0.005.The upper limit is below 0.67 in theory.If be lower than this scope, even then apply the mechanics energy process, the raising of orientation ratio is also insufficient, and the high density charge-discharge characteristic reduces sometimes.
(11) draw ratio (powder)
The draw ratio of graphite-like carbonaceous particle is that the upper limit is generally below 10 more than 1 in theory, is preferably below 8, more preferably below 5.If surpass its upper limit, even then apply the mechanics energy process, draw ratio can not fully reduce, and can produce striped when processing pole plate, can't obtain uniform coated face, and the high current density charge-discharge characteristic reduces sometimes.
In the above-mentioned raw material graphite-like carbonaceous particle; As the high crystalline material with carbon element of carbon hexagonal net surface structure prosperity, can enumerate the height that the hexagonal wire side is obviously grown with planar orientation and be orientated graphite and make the isotropism high-density graphite on the directions such as the high graphite particle that is orientated is integrated into.As preferred high orientation graphite, the so-called kish that can enumerate native graphite that Sri Lanka or Madagascar produces, separate out with the form of oversaturated carbon by the iron of fusion, the Delanium of part high graphitization degree etc.
Native graphite is according to its proterties; Be classified as flaky graphite (Flake Graphite), flaky graphite (Crystalline (Vein) Graphite), soil graphite (Amorphous Graphite) (referring to " powder body technology technology is integrated "; One in the graphite of ((strain) industrial technology center, clear and distribution in 49 years); And " HAND BOOK OF CARBON, GRAPHITE, DIAMOND AND FULLERENES ", (Noyes Publications distribution)).Degree of graphitization is the highest with flaky graphite, is 100%, then is flaky graphite, be 99.9%, and soil graphite is low to moderate 28%.Flaky graphite as native graphite originates from Madagascar, China, Brazil, Ukraine, Canada etc.; Flaky graphite mainly originates from Sri Lanka.The main product ground of soil graphite is the Korea peninsula, China, Mexico etc.In these native graphites, the common particle diameter of soil graphite is little, and purity is low.In contrast, flaky graphite or flaky graphite have advantages such as degree of graphitization height, impurity level are few, therefore can preferably use in the present invention.
Delanium can made through petroleum-type heavy oil, coal class heavy oil, petroleum-type coke or coal class coke are heated under 1500～3000 ℃ or its this temperature more than temperature under the non-oxidizable atmosphere.
In the present invention, be orientated and high power capacity, then can use arbitrarily Delanium as raw material as long as carrying out mechanics energy process and heat treatment after, show height.In addition; In above-mentioned Delanium, even the incomplete material of graphitization, for example graphite precursor; As long as it can become the graphite matter carbon particle that satisfies above-mentioned rerum natura through carrying out the mechanics energy process, the raw material that then can be used as mechanics energy process of the present invention uses.
[[[mechanics energy processed content]]]
The mechanics energy process that these raw material graphite-like carbonaceous particles are carried out can reduce particle diameter; Making the ratio of the volume average particle size before handling the back and handling is below 1; And improve tap density through this processing, Raman R value is reached more than 1.1 times through this processing.
Through carrying out such mechanics energy process, become following particle as the carbonaceous particles such as graphite-like carbonaceous particle of raw material: keep high crystalline on the whole, just the near surface of particle becomes coarse, tilts and exposes edge surface.Like this, the face that lithium ion can be come in and gone out increases, even under high current density, also have high capacity.
In the primitive operation that can effectively be utilized on the engineering in the seed designs such as pulverizing, classification, mixing, granulation, surface modification, reaction; " mechanics energy process " among the present invention belongs to " pulverization process ", but also comprise simultaneously through surface texture is impacted, friction or compression etc. produce the such surface treatment of fine fault of construction.
In general, so-called pulverization process is meant material is applied power, and its size is reduced with the particle diameter of regulating material or particle size distribution, fillibility.Pulverization process is classified according to kind, the processing form of the power that material is applied.The power that material is applied roughly is divided into following 4 kinds: (1) is beaten power (impulsive force), (2) crushing force (compression stress), (3) and is ground power (grinding power), cuts the power of scraping (shearing force).On the other hand, handle form and roughly be divided into following 2 kinds: pulverize on the surface of pulverizing and cut particle surface at the inner volume that produces be full of cracks and make it to propagate of particle.Volume is pulverized and can be adopted impulsive force, compression stress, shearing force to carry out; The surface pulverizing can adopt the power of grinding, shearing force to carry out.Pulverization process is with the kind of the power that these materials are applied and handles the processing that form is carried out various combinations.Its combination can suitably be confirmed according to processing intent.Though pulverization process also has the reaction of using chemistry such as explosion or the situation that volumetric expansion is carried out, use mechanical device such as pulverizer to carry out usually.
The preferred mechanics energy process of using preferably finally comprises the processing that the shared ratio of pulverizing (pulverize on the surface) that surface treatment gets the particle surface part uprises in the manufacturing of graphitic carbon plasmid of the present invention, and with to have or not volume to pulverize irrelevant.This be because, the pulverizing of particle surface for the angle of removing carbonaceous particles such as graphitic carbon plasmid so that shape of particle becomes circle is important.Particularly, can carry out surface after pulverizing again and pulverize and carry out the mechanics energy process in this wise carrying out to a certain degree volume, also can carry out the volume pulverizing hardly and only carry out the surface pulverizing and carry out the mechanics energy process in this wise.Can also carry out the volume pulverizing simultaneously and carry out the mechanics energy process in this wise with the surface pulverizing.Preferably carry out the surface at last and pulverize, remove the angle from the surface of particle and carry out the mechanics energy process in this wise.
Mechanics energy process of the present invention can reduce particle diameter, and making the ratio of the volume average particle size before handling the back and handling is below 1, and improves tap density through this processing, through this processing Raman R value is reached more than 1.1 times.
So-called " ratio of the volume average particle size before and after handling " is the value that the volume average particle size after handling obtains divided by the volume average particle size before handling.The value of (volume average particle size after the processing)/(volume average particle size before handling) is below 1, to be preferably below 0.95.If be essentially 1, the effect that the fillibility that then obtains through mechanics energy process raising circularity improves is sometimes very little.In addition, can also through reduce particle size make to handle the back and handle before the ratio of average grain diameter be 1 to control shape of particle to get off.
Mechanics energy process through among the present invention can improve tap density.Improve tap density and be meant that like the described raising in back be the spheroidization degree of representative with the circularity.Therefore, the mechanics energy process must be such processing.The value of (tap density after the processing)/(tap density before handling) is more than 1, to be preferably more than 1.1.If be lower than 1, then to improve the effect that the fillibility brought improves sometimes very little for circularity.
Can make Raman R value through the mechanics energy process among the present invention is more than 1.1 times.Improve Raman R value and be meant that the mechanics energy process must be such processing like near the crystallinity the described reduction particle surface in back.The value of (the Raman R value after the processing)/(the Raman R value before handling) is more than 1.1, to be preferably more than 1.4.If be lower than 1.1, then because the effect that the caused charging acceptance of Raman R value variation improves is sometimes very little.
Mechanics energy process of the present invention is to make particle become circle, thereby the tap density of these particles is risen.In order to improve the tap density of powder particle, the littler particle that known filling can enter into the space that forms between particle and the particle is preferred.Therefore, think that then can improve tap density, but adopt such method to reduce particle diameter, in general tap density reduces on the contrary if carbonaceous particles such as graphite-like carbonaceous particle processing such as are pulverized to reduce particle diameter.As its reason, think because pulverizing makes shape of particle become more amorphous.
On the other hand, the number (ligancy n) of the particle that contacts with a particle (particle of concern) in the powder particle group is many more, and the shared ratio in the space of packed layer reduces.That is, as the factor of tap density being brought influence, the ratio of the size of particle and ratio of components, promptly particle size distribution is important.But; This research is just carried out with the spheroidal particle group of model; Carbonaceous particles such as graphite-like carbonaceous particle before the processing of using among the present invention are flakey, squamous, tabular; Control particle size distribution though attempted only adopting common pulverizing, classification to wait, thereby improve tap density, can not produce such high occupied state.
In general, the particle diameter of flakey, squamous, tabular carbonaceous particles such as graphite-like carbonaceous particle is more little, and its tap density has the tendency of reduction more.This can think because following reason: since particle through pulverizing amorphization more; And " burr " that particle surface generates, " peeling off " or overshooting shape things such as " warpages " increase; And be attached with finer reasons such as amorphous particle with to a certain degree intensity at particle surface; Like this, and big in abutting connection with the change of the impedance between the particle, fillibility is worsened.
If the amorphism of these particles reduces, shape of particle approaches sphere, even then particle diameter diminishes, the reducing of fillibility also tails off, and in theory, big particle diameter particle, small particle diameter particle all should show the tap density of equal extent.
The inventor etc. have confirmed following content through research: carbonaceous that real density equates basically, average grain diameter also equates basically or graphite plasmid, and shape is spherical, and tap density shows high value more.That is, make the shape of particle band with circular, it is important approaching sphere.If the shape of particle subglobular, then the fillibility of powder also obviously improves simultaneously.Among the present invention, because above-mentioned reason, the index when applying the mechanics energy adopts the tap density of powder.When the fillibility of the powder body after the processing rises than processing is preceding, can think the result who the particle spheroidization is brought through the processing method of using.In addition; In the method for the present invention; Handle the tap density of the material with carbon element of the equal extent particle diameter that the tap density of the material with carbon element that makes when particle diameter obviously reduces to be obtained obtains with adopting common pulverizing and compare,, can think the result of spheroidization if when showing high value.
As the crystallinity of particle and the roughness of particle surface, the index of the edge surface amount of crystallization just can be used interplanar distance (d002), crystallite size (Lc) and Raman R value through (002) face of wide-angle x-ray diffraction mensuration.In general, material with carbon element is little, the big material of crystallite size (Lc) of value of the interplanar distance (d002) of (002) face, and its Raman R value is more little.That is, whole carbonaceous particles of graphite-like carbonaceous particle etc. almost present same crystalline state.In contrast, though the value of the interplanar distance (d002) of graphite matter carbon particle of the present invention (002) face is little, crystallite size (Lc) big, Raman R value is taked big value.Promptly; Though the piece crystallinity of graphite matter carbon particle is high; But the crystallinity of near surface (apart from particle surface level) is chaotic, show edge surface to expose change many.
From improving the viewpoint of fillibility, more preferably make circularity reach 1.02 times through the mechanics energy process among the present invention, especially preferably make circularity reach 1.04 times.
[[[the employed device of mechanics energy process]]]
Carrying out the device of mechanics energy process selects from the device that can carry out above-mentioned preferred processing.The inventor etc. find when studying; Though more than one that use above-mentioned 4 kinds of power that material is applied also can be realized; But preferred following device: with impulsive force is main, and particle is applied the mechanisms such as compression, friction, shearing force of the interaction that comprises particle repeatedly.Particularly; Preferred following device: this device has the rotor that is provided with a plurality of blades in case inside; And give the effect of machineries such as Shock Compression, friction, shearing force through the rotation of this rotor high-speed and to importing to inner carbonaceous particle, thereby the limit is carried out volume and is pulverized the limit and carry out surface pulverizing.In addition, more preferably have through making circulation of carbonaceous particle or convection current and give the device of the mechanism of mechanism repeatedly.The quantity of the blade that case is inner is preferred more than 3, preferred especially more than 5.
As an example of the preferred device that satisfies such important document, can enumerate the hybrid system that (strain) nara machinery is made institute's manufactured.When using this device to handle, preferably the peripheral speed with rotor rotated is set at 30～100m/ second, more preferably is set at 40～100m/ second, further is preferably set to 50～100m/ second.In addition, processing can be that the carbonaceous particle is passed through, but preferably in device circulation or be detained 30 seconds with on handle, more preferably in device, circulate or be detained 1 minute with on handle.
Real density as the graphite-like carbonaceous particle of raw material is lower than 2.25, and crystallinity preferably further improves crystalline heat treatment when so high after carrying out the mechanics energy process.Such heat treatment is preferably being carried out more than 2000 ℃, is more preferably carrying out more than 2500 ℃, is further preferably carrying out more than 2800 ℃.
[making the electrode of negative pole [6]]
Make negative pole and can adopt usual way, can with the above-mentioned negative pole [6] that likewise forms.The ratio of the thickness of collector body, collector body and active material layer, electrode density, adhesive, pole plate orientation ratio, impedance etc. are also same as described above.
< negative pole [7] >
Below; Negative pole [7] to using in the lithium secondary battery of the present invention describes; This negative pole contain comprise multielement negative electrode active material (C) as negative electrode active material; The said negative electrode active material (C) that comprises multielement contains at least a in the lithium occlusion metal (A) that is selected from Al, Pb, Zn, Sn, Bi, In, Mg, Ga, Cd, Ag, Si, B, Au, Pt, Pd and Sb and/or the lithium occlusion alloy (B), and contains C and/or N as element Z.
[negative electrode active material of negative pole [7]]
Below, the negative electrode active material that uses in the anticathode [7] describes.
[[composition]]
The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [7] is characterised in that, contain at least can the occlusion lithium metal (lithium occlusion metal (A)) and/or alloy (lithium occlusion alloy (B)), and contain C and/or N as element Z.
So-called lithium occlusion metal (A) is meant to be selected among Al, Pb, Zn, Sn, Bi, In, Mg, Ga, Cd, Ag, Si, B, Au, Pt, Pd and the Sb more than one.Wherein, be preferably Al, Si, Sn or Pb, more preferably Si or Sn further are preferably Si.As the reason of preferred Si, the capacity that can enumerate per unit mass is big.
So-called lithium occlusion alloy (B) is meant the alloy that contains above-mentioned lithium occlusion metal (A) more than 2 kinds, perhaps in lithium occlusion metal (A), contains the alloy of " element beyond lithium occlusion metal (A) and C, the N ".As this " element beyond lithium occlusion metal (A) and C, the N "; Be preferably selected from a kind of or element more than 2 kinds in periodic table 4 families, 5 families, 6 families, 8 families, 9 families, 10 families, 11 families, 13 families, 16 families; More preferably Ti, Zr, V, Cr, W, B, O, Co element further are preferably Ti, Zr, W, O, Co element.Because these elements form high melting compound easily, therefore put at reactive this of control, can preferably use.From the viewpoint of capacity, the content that forms " lithium occlusion metal (A) and C, the N element in addition " of alloy is 50 moles below the % with respect to lithium occlusion alloy (B) preferably.
In addition, as C and/or the contain mode of N in comprising the negative electrode active material of multielement (C) of element Z, mode can be listed below:
1. the state that in lithium occlusion metal (A) and/or lithium occlusion alloy (B), contains (including the lithium occlusion material (D) of element Z);
2. the state (the external lithium occlusion of element Z material (F)) on every side that is present in lithium occlusion metal (A) and/or lithium occlusion alloy (B);
3. above-mentioned 1 and 2 the compound state of state.
As the preferred mode of the lithium occlusion material (D) that includes element Z, preferred elements Z (C and/or N) is present in lithium occlusion metal (A) and/or the lithium occlusion alloy (B) with nonequilibrium condition, and special preferred, lithium occlusion metal (A) is Si.
As the preferred mode of the external lithium occlusion of element Z material (F), preferred elements Z is C, and C can show the state of conductivity.
The negative electrode active material that comprises multielement (C) that uses among the present invention as negative electrode active material; Contain lithium occlusion metal (A) and/or lithium occlusion alloy (B); And contain C and/or N for must composition, preferably further contain a kind of or element more than 2 kinds that is selected from periodic table 4 families, 5 families, 6 families, 8 families, 9 families, 10 families, 11 families, 13 families, 16 families.As such element, more preferably Ti, Zr, V, Cr, W, B, O, Co element further are preferably Ti, Zr, W, O, Co element.
1. include the lithium occlusion material (D) of element Z
In the lithium occlusion metal of the present invention (A), because Si obtains effect easily, therefore, as the lithium occlusion material (D) that includes element Z, the compound that preferably is present in the phase among the Si with element Z is the general formula SiZ of principal component non-equilibriumly xM yThe material of (in the formula, Z, M, x, y are shown in following condition (1)～(4)) expression.
(1) element Z is the element that comprises C and/or N;
(2) element M is a kind of in the element that is selected from beyond Si and the element Z or more than 2 kinds;
(3) x makes Z concentration ratio Q (Z) reach 0.10～0.95 value; Said Z concentration ratio Q (Z) is with respect to the compound S iaZp that exists with the Compositional balance that approaches most Si (in the formula; A, p are integer) Z concentration (p/ (a+p)), calculate by formula Q (Z)=[x/ (1+x)]/[p/ (a+p)];
(4) y is the number of 0≤y≤0.50 scope.
(about SiZ xM y)
((element Z))
SiZ xM yIn element Z be the element that comprises C and/or N.In addition, preferred C and/or N the reasons are as follows as the element Z that includes:
(1) can form the compound higher than Si fusing point;
(2) covalent radius is littler than Si;
(3) diffusion coefficient in Si is little;
(4) even react with lithium, its change in volume is also little etc.
Particularly, Elements C, N can form SiC, Si 3N 4Compound Deng the fusing point balance existence higher than Si.And the free energy that high melting compound usually generates is very stable compound for negative, therefore from can effectively reducing the activity of Si, suppresses the reactive viewpoint with nonaqueous electrolytic solution, and preferred C and/or N are as element Z.
In addition, because Elements C, N are littler than the covalent bond atomic radius of Si, therefore can think to be difficult to be formed on SiZ xM yThe compound that balance exists in the compound, under high concentration, more evenly distributing for element Z is effectively, though its details is not really clear, from can effectively reducing the activity of Si, reactive viewpoint of inhibition and nonaqueous electrolytic solution is preferred.
In addition, Elements C, the N diffusion coefficient in Si is little, thus Elements C, when N is dispersed among the Si, the cohesion or the crystallization that are accompanied by the Si that discharges and recharges generation are suppressed, and are preferred from the viewpoint of the reaction of the micronizing inclusive NAND water electrolysis liquid that suppresses Si.In addition, even because Elements C, N and lithium reaction, its change in volume is also little, therefore is difficult for the conductive path cut-out of Si is brought influence, so preferred.
In addition, as elements such as Cu, Ni, Cu 3Si, Ni 2The compound that Si etc. can balance exist is during than the Si low melting point; The activity of Si is effectively reduced and be difficult to suppress the reactivity with nonaqueous electrolytic solution; And Cu, the diffusion coefficient of Ni element in Si are big; Therefore be accompanied by and discharge and recharge cohesion or the crystallization that carries out Si, cause the micronizing of Si easily, cycle characteristics can not be enhanced sometimes.In addition, at SiZ xM yWhen the compound that balance exists in the compound becomes principal component, the activity of Si is reduced, and can not suppress the reactivity with nonaqueous electrolytic solution, therefore have situation such as cycle characteristics deterioration.
((element M))
SiZ xM yIn element M be select the element beyond Si and element Z a kind of or element more than 2 kinds; Be preferably a kind of or element more than 2 kinds that is selected from periodic table 4 families, 5 families, 6 families, 8 families, 9 families, 10 families, 11 families, 13 families, 16 families; Owing to form high melting compound easily; This puts from inhibitory reaction property, and more preferably Ti, Zr, V, Cr, W, B, O element further are preferably Ti, Zr, W, O element.
At SiZ xM yComposition in, SiZ xM yX make Z concentration ratio Q (Z) reach the value of following scope; Said scope is: be generally more than 0.10, be preferably more than 0.15, more preferably more than 0.30, be preferably more than 0.40 especially; In addition, the upper limit is generally below 0.95, is preferably below 0.85, more preferably below 0.75, further be preferably below 0.65; Said Z concentration ratio Q (Z) is with respect to the Z concentration (p/ (a+p)) of the compound S iaZp that exists with the Compositional balance that approaches most Si (in the formula, a, p are integer), is calculated by formula Q (Z)=[x/ (1+x)]/[p/ (a+p)].In addition, said " compound that exists with the Compositional balance that approaches most Si " is meant in SiaZp, and the value of p/ (a+p) is got minimum and compound S iaZp that balance exists.
In addition; The compound S iaZp that the Compositional balance to approach most Si among the present invention exists at the phasor of Si and element Z (for example; " the Desk Handbooks Phase Diagrams for Binary Alloys " that ASM International company publishes) on the books in; In the present invention, set above-mentioned Z concentration ratio Q (Z) with respect to the Z concentration (p/ (a+p)) of this SiaZp, and the number range of use Z concentration ratio Q (Z) limits the scope of x.
Here the compound that said so-called balance exists is as the compound S i of the summit record of line chart in above-mentioned phasor etc. aZ pDaltonides such as (in the formula, a, p are integer), for example, when Z was C, known SiC was stable compound, in the present invention, with the compound of this compound as the balance existence.Therefore, when Z was C, SiC was equivalent to Si of the present invention aZ pIn addition, when for example Z is N, though known Si 3N 4Be the most stable compound, but also known Si 2N 3, SiN also exists as daltonide, in the present invention, the compound that the compound that these are all exists as balance.Therefore, when Z was N, SiN was equivalent to Si of the present invention aZ p
On the other hand, the compound of the phase of so-called non-equilibrium existence is meant the compound compound in addition that balance exists.Under the situation of the compound of non-equilibrium existence, do not form specific daltonide, see that from macroscopic view Si atom and Z atom evenly disperse.
Z concentration ratio Q (Z) is if be lower than this scope, and the effect of activity that then reduces Si is little, can not suppress the reactivity with nonaqueous electrolytic solution, and electrode expands and becomes big, can not obtain preferred cycle characteristics sometimes.On the other hand, if surpass this scope, then form the stable compound S i that balance exists aZ pDeng, even increase element Z, the activity of Si does not also reduce, and can not suppress the reactivity with nonaqueous electrolytic solution sometimes.In addition, because Si aZ pDeng conductivity low, therefore when forming such compound, the conductivity of active material worsens, the doping of lithium, the dedoping difficulty that becomes can not discharge and recharge sometimes.
Here, Z concentration ratio Q (Z) is 1 o'clock, means that Si forms stable compound S i aZ p, not preferred.In addition,, then be difficult to obtain to contain the effect of the high capacity that Si brings, can not obtain preferred battery behavior sometimes if significantly surpass this scope.
In addition, as element Z, when using C and N element at the same time, obtain Si with respect to each of 2 kinds of elements aZ pThe Z concentration ratio Q (Z) of the element Z concentration of benchmark, and regard its aggregate value as Z concentration ratio Q (Z).
SiZ xM yIn y be the real number that satisfies 0≤y≤0.5.Compound S iZ xM yIn contain element M, and y ≠ 0 o'clock, compound S iZ xM yIn the ratio y of element M be generally more than 0.08, be preferably more than 0.10, in addition, its upper limit is generally below 0.50, is preferably below 0.40, more preferably below 0.30.If y surpasses this scope, then the content of Si tails off, and is difficult to obtain high power capacity sometimes.When not containing element M in fact; The ratio y of element M be y=0 or
Figure BDA0000087738240001331
in the present invention; So-called
Figure BDA0000087738240001332
is meant in the manufacturing process of the negative electrode active material that the present invention relates to etc.; Contain the element M situation of (not containing M in fact) inevitably; For example, y is less than 0.08 situation.
The composition that comprises the negative electrode active material (C) of multielement can be obtained according to usual way; For example, use X ray photoelectricity optical splitter (for example, " ESCA " of ulvac-phi manufactured); Make and contain negative polarization compound one side and be placed on up on the test portion platform; And it is had an even surface, as x-ray source, carry out depth curve (デ プ ス プ ロ Off ア イ Le with the K alpha ray of aluminium while carry out the Ar sputter; Depth profile) measures, calculate the atomic concentration of Si, element Z, element M etc. respectively.
(SiC xO yComposition)
Element Z is that C and element M are when being O, at general formula SiC xO yIn, x is generally more than 0.053, is preferably more than 0.08, more preferably more than 0.15, is preferably especially more than 0.25, and its upper limit is generally below 0.90, is preferably below 0.75, more preferably below 0.60, is preferably below 0.45 especially.In addition, y is generally more than 0, is preferably more than 0 value, is preferably especially more than 0.08, and more preferably more than 0.10, in addition, its upper limit is generally below 0.50, is preferably below 0.40, is preferably below 0.30 especially.
(including the existence of element Z in Si in the lithium occlusion material (D) of element Z)
At negative polarization compound SiZ of the present invention xM yIn, for the existence of element Z in Si, the not special restriction of the XIsz value that its X-ray diffraction is measured when element Z is C, is preferably below 1.2, more preferably below 0.7.When element Z is N, be preferably below 1.1, more preferably below 1.0.The XIsz value be this below scope, be meant that be present in element Z among the Si is principal component non-equilibriumly mutually, and Si aZ pThe compound that isoequilibrium exists is not a principal component, can not produce the problem that following XIsz value surpasses the situation of above-mentioned scope, so preferred.When the XIsz value surpasses above-mentioned scope, i.e. Si aZ pThe compound that isoequilibrium exists mutually for principal component (element Z is that carborundum, element Z are silicon nitrides during for N during for C) time, have following situation: the activity of Si is reduced, can not suppress the reactivity with nonaqueous electrolytic solution, the situation that cycle characteristics worsens; Because Si aZ pDeng conductivity low, the conductivity of active material film worsens, the doping of lithium, the dedoping difficulty that becomes, thereby the situation that can not discharge and recharge; The perhaps discharge capacity of per unit mass active material situation about diminishing.The lower limit of XIsz value is generally more than 0.00.
((X-ray diffraction assay method))
XIsz value through X-ray diffraction is measured for example can be arranged to shadow surface with negative electrode active material of the present invention; And (for example use the X-ray diffraction device; " the X-ray diffraction device " of (リ ガ Network) manufactured of science) measure, for condition determination, as after shown in the embodiment that states.
In addition, the definition of XIsz value is following.
(((the XIsz value when element Z is C)))
Peak intensity Isz, 2 θ that measure 2 θ and be 35.7 degree are the peak intensity Is of 28.4 degree, calculate its strength ratio XIsz (XIsz=Isz/Is), and it is defined as the XIsz of active material film.Here, 2 θ are the peak that SiC is thought to come from the peak of 35.7 degree, and the peak of 28.4 degree is the peaks that come from silicon, and the XIsz value is to be meant below 1.2 almost not detect SiC.
(((the XIsz value when element Z is N)))
Peak intensity Isz, 2 θ that measure 2 θ and be 70.2 degree are the peak intensity Is of 28.4 degree, calculate its strength ratio XIsz (XIsz=Isz/Is), and it is defined as the XIsz of active material film.Here, 2 θ be 27.1 the degree the peak think to come from Si 3N 4The peak, 28.4 the degree the peak be the peak that comes from silicon, the XIsz value is to be meant below 1.1 almost not detect Si 3N 4
(including the distribution of the element Z in the lithium occlusion material (D) of element Z)
SiZ of the present invention xM yIn element Z for example exist with lower horizontal size with atom or molecule or cluster 1 μ m such as (cluster), the distribution of element Z is preferably at SiZ xM yIn evenly distribute, more preferably from SiZ xM yCentral part make the concentration gradient of element Z uprise crustal inclination to surface direction (under the situation of the film like negative material of afterwards stating, to make concentration gradient uprise crustal inclination to film surface from contact portion with collector body; Under the situation of Powdered negative material, make concentration gradient uprise crustal inclination to film surface from the particle central part) distribute.In negative electrode active material, local unevenly when having the distribution of element Z, be accompanied by expansion that discharging and recharging of Si cause and concentrate and occur in the Si part that does not have element Z, therefore, along with the carrying out of circulation, conductivity worsens sometimes.The dispersity of element Z can be through affirmations such as EPMA shown in the back.
(distribution of element M)
SiZ of the present invention xM yIn the not special restriction of distribution of element M, can be even distribution, also can be uneven distribution.
(Raman RC value, Raman RSC value, Raman RS value)
The Raman RC value that the lithium occlusion material (D) that includes element Z among the present invention is measured through Raman spectrum analysis is generally more than 0.0, and its upper limit is preferably below 2.0.If Raman RC value surpasses this scope, then be difficult to obtain to contain the effect of the high capacity that Si brings, be difficult to obtain preferred battery behavior.When particularly element Z contains C, about negative electrode active material SiZ of the present invention xM yRaman RC value, be preferably below 2.0, more preferably below 1.0, be preferably below 0.5 especially.Because on measuring, the lower limit of Raman RC value is generally more than 0.0.
The Raman RSC value that the lithium occlusion material (D) that includes element Z among the present invention is measured through Raman spectrum analysis is generally more than 0.0, and its upper limit is preferably below 0.25.If Raman RSC value surpasses this scope, then conductivity worsens, and it is difficult that the doping of lithium, dedoping become, and can not discharge and recharge sometimes.In addition, when particularly element Z contained C, the RSC value was preferably below 0.25, more preferably below 0.20.Because on measuring, the lower limit of Raman RSC value is generally more than 0.0.
The Raman RS value that the lithium occlusion material (D) that includes element Z among the present invention is measured through Raman spectrum analysis is preferably more than 0.40, and more preferably more than 0.50, its upper limit is preferably below 1.00, more preferably below 0.90.If Raman RS value is lower than this scope, then cycle characteristics might worsen.On the other hand,, then might be able to not discharge and recharge if surpass this scope, not preferred.When particularly element Z contained C, the RS value was preferably more than 0.40, more preferably more than 0.50; Its upper limit is preferably below 0.75, is preferably below 0.65.When particularly element Z contained N, the RS value was preferably more than 0.40, more preferably more than 0.50; Its upper limit is preferably below 1.00, is preferably below 0.90.
The Raman RC value of passing through Raman spectrum analysis mensuration among the present invention, Raman RSC value, Raman RS value are tried to achieve by the Raman spectrum analysis of the Raman assay method below adopting, and respectively as giving a definition.
((Raman assay method))
Use raman spectroscopy device (for example, " the raman spectroscopy device " of Japanese beam split manufactured), anode for nonaqueous electrolyte secondary battery of the present invention is installed in the cell, to the irradiation argon laser of the specimen surface in the pond and measure.Through the Raman spectrum of measuring being carried out the background compensation, obtain Raman RC value, Raman RSC value, Raman RS value.In addition, the background compensation is carried out as follows: with the whole initial point at straight line connection peak, obtain background, deduct this value by peak intensity again.
The Raman condition determination here is following, and smooth treatment is the simple average of 15 of convolution.
Argon laser wavelength: 514.5nm
Laser power on the sample: 15～40mW
Resolution: 10～20cm -1
Measurement range: 200cm -1～1900cm -1
(((Raman RC value)))
Measure 1300cm -1～1600cm -1Peak intensity Ic, the 300cm of near the peak c that occurs -1～500cm -1The peak intensity Ias of the peak as that occurs near calculates its strength ratio RC (RC=Ic/Ias), and it is defined as the Raman RC value of negative pole.Here, can think that peak c and peak as are the peaks that comes from carbon and silicon respectively, therefore, the amount of Raman RC value reflection carbon, Raman RC value is to be meant below 2.0 almost not detect carbon.
(((Raman RSC value)))
Measure 650cm -1～850cm -1Peak intensity Isc, the 300cm of near the peak sc that occurs -1～500cm -1The peak intensity Ias of the peak as that occurs near calculates its strength ratio RSC (RSC=Isc/Ias), and it is defined as the Raman RSC value of negative pole.
Here, can think that peak sc and peak as are respectively the peaks that comes from SiC and silicon, therefore, the amount of Raman RSC value reflection SiC, Raman RSC value is to be meant below 0.25 almost not detect SiC.
(((Raman RS value)))
Measure 520cm -1Intensity I s, 300cm -1～500cm -1The peak intensity Ias of the peak as that occurs near calculates its strength ratio RS (RS=Is/Ias), and it is defined as the Raman RS value of negative pole.The state of Raman RS value reflection Si.
(IRsc value)
For the negative pole with negative electrode active material that uses among the present invention after discharging and recharging, the IRsc value through the assay determination of infrared external reflection light is preferably more than 0.90, more preferably more than 1.1, is preferably more than 1.2 especially.If IRsc is lower than this scope, then in circulation, contain negative pole and the nonaqueous electrolytic solution reaction of Si, the active matter quality that can discharge and recharge in fact slowly reduces, and is difficult to obtain preferred cycle characteristics sometimes.The higher limit of IRsc value is about 3.0.In addition, the IRsc value of the employing infrared external reflection light assay determination of the negative pole among the present invention is tried to achieve by the following infrared external reflection light measurement that utilizes infrared spectrophotometer to carry out, and defines as follows.
((the infrared external reflection light analysis determining method that utilizes infrared spectrophotometer to carry out))
(for example will use infrared spectrophotometer; Hot electron (サ one モ エ レ Network ト ロ Application; Thermo electron) " Magna560 " of manufactured), the active material face of the negative pole of the lithium secondary battery after discharging and recharging is installed in the cell, measures through bounce technique.Measure to use window material be adamantine reflection measurement with sample retainer (Off オ Le ダ one), under inactive atmosphere, carry out.Through the background compensation of the infrared absorption spectrum measured, obtain the IRsc value.In addition, the background compensation is carried out as follows: connect 2000～4000cm -1The minimum value of scope, and, obtain background with the straight line prolongation, deduct this value by each intensity again.Measure 1600cm -1Under intensity of reflected light Isc, 1650cm -1Under intensity of reflected light Iaco, calculate its strength ratio IRsc (IRsc=Isc/Iaco), it is defined as the IRsc value after discharging and recharging.
Though details is also indeterminate; But think that Isc is the epithelium that comes from Si; Iaco is the epithelium that comes from the alkyl lithium carbonate; Therefore, (solid electrolyte interface: state SEI) and amount ratio, the value of IRsc are to mean more than 0.9 by epithelium that comes from the alkyl lithium carbonate and the epithelium that comes from Si to constitute to the epithelium of IRsc reflection negative pole.
< effect, principle >
At first, activity is described.In general, so-called activity is a kind of thermodynamics concentration.For inclusion quality n 1, n 2N iThe multicomponent system, if the chemical potential of component i is set at μ i, the chemical potential of pure material is set at μ i 0, then will be with following formula
μ i-μ i 0＝RTloga i
The a of definition iBe called activity.
In addition, with activity a iAnd concentration c iRatio γ iBe called activity coefficient.
a i/c i＝γ i
For example; When a certain system that will comprise solvent and solute was considered as thermodynamic (al) solution, activity coefficient was the amount of difference of the real chemical potential of the chemical potential of a certain composition when regarding system as perfect solution and a certain composition when regarding system as real solution.(1) be that if the concentration step-down of solute, then system approaches the perfect solution that component i is a solute under the situation of real solution of solute in a certain component i, activity coefficient approaches 1.On the contrary, (2) are that if the concentration of solvent uprises, then system approaches the perfect solution that component i is a solvent under the situation of real solution of solvent in a certain component i, and activity coefficient approaches 1.In addition, when real solution was stablized than perfect solution, the chemical potential of component i was γ i＜1.
In the present invention, be example if enumerate the Si that shows superperformance, component i is Si, through containing the element Z that is counted as solute, the activity ai of solvent Si reduces, γ in being counted as the Si of solvent i＜1, the Si compound (solid solution: regard real solution as) that contains element Z is more stable than Si (regarding perfect solution as), and its result can suppress the reactivity with nonaqueous electrolytic solution.
But, if form the compound S i of Si and the existence of element Z balance aZ pDeng, then can not effectively reduce the activity of Si, therefore, it is important that element Z exists in Si non-equilibriumly.
[form of negative pole [7]]
The form of the negative electrode active material that uses in the negative pole [7] in the present invention, is generally film like or Powdered.In the present invention; Such as after the manufacturing approach stated record; Use the negative pole of film like active material to obtain through on collector body, active material layer being carried out the gas phase film forming, the negative pole of Powdered active material can through for example on collector body coated powder shape active material and adhesive etc. form active material layer.
[[film like active material]]
[[[structure]]]
As the structure of the film like active material of film forming on collector body, for example can enumerate column structure, layer structure etc.
[[[thickness]]]
The thickness of film like active material is suitable with the thickness of the active material layer that uses this film like active material, is generally more than the 1 μ m, is preferably more than the 3 μ m, and in addition, its upper limit is generally below the 30 μ m, is preferably below the 20 μ m, more preferably below the 15 μ m.If the thickness of film like active material is lower than this scope; Then use the capacity of its each piece of negative pole of the present invention (below, will use the negative pole of film like active material to be called sometimes " film cathode ") of this film like active material little, in order to obtain jumbo battery; Need a large amount of negative poles; Therefore, correspondingly, it is big that the total measurement (volume) of the collector body of the positive pole that needs, dividing plate, film cathode itself becomes; The negative electrode active material that per unit battery volume can be filled reduces in fact, is difficult to increase battery capacity.On the other hand, if surpass this scope, then owing to discharge and recharge the expansion that causes, the film like active material layer is peeled off from the collector body substrate sometimes, and cycle characteristics might worsen.
[[Powdered active material]]
[[[shape]]]
As the shape of Powdered active material, for example can enumerate sphere, polyhedron shape, amorphous etc.
[[[volume reference average grain diameter]]]
The not special restriction of the volume reference average grain diameter of Powdered active material is generally more than the 0.1 μ m, is preferably more than the 1 μ m, and more preferably more than the 3 μ m, in addition, its upper limit is generally below the 50 μ m, is preferably below the 30 μ m, more preferably below the 25 μ m.If the volume reference average grain diameter of Powdered active material is lower than above-mentioned scope; Then because particle diameter is too small; Be difficult to obtain between Powdered active material conductive path or Powdered active material and after conductive path between the conductive agent stated, cycle characteristics worsens sometimes.On the other hand, if surpass above-mentioned scope, then as hereinafter described pass through to be coated on when making negative electrode active material layer on the collector body, produce uneven sometimes.
In addition; Volume reference average grain diameter as Powdered active material; Use the following value of measuring: in the 2 volume % aqueous solution (about 1mL) of mixing as polyoxyethylene (20) Span-20 of surfactant, as decentralized medium, laser diffraction/diffuse transmission type particle size distribution meter (for example in use with ion exchange water in determination object; The hole field makes " LA-920 " of institute's manufactured), the average grain diameter (median particle diameter) of mensuration volume reference.After among the embodiment that states, obtain the volume reference average grain diameter through this method.
[[[BET specific area]]]
The not special restriction of the BET specific area of Powdered active material, but be generally 0.1m 2More than/the g, be preferably 0.5m 2More than/the g, 1.0m more preferably 2More than/the g, in addition, be generally 100m 2Below/the g, be preferably 30m 2Below/the g, 15m more preferably 2Scope below the/g.If the value of BET specific area is lower than the lower limit of above-mentioned scope, then be used under the situation of negative pole, when the charging of battery, the easy variation of the acceptance of lithium, lithium is separated out at electrode surface easily, therefore sees not preferred from safety.On the other hand, if the value of BET specific area surpasses the upper limit of above-mentioned scope, then when processing negative pole, with the reactivity increase of nonaqueous electrolytic solution, it is many that the gas of generation becomes, and is difficult to obtain preferred battery sometimes.
In addition; The BET specific area of Powdered active material is used the following value of measuring: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made), under nitrogen circulation, 350 ℃ to Powdered active material carry out 15 minutes predrying, then; Use nitrogen accurately to be adjusted into 0.3 nitrogen helium gas mixture body, measure through the nitrogen absorption BET1 point method that adopts the gas flow method with respect to atmospheric relative pressure value.
[[[tap density]]]
The not special restriction of the tap density of Powdered active material is generally 0.2g/cm 3More than, be preferably 0.3g/cm 3More than, 0.5g/cm more preferably 3More than, in addition, be generally 3.5g/cm 3Below, be preferably 2.5g/cm 3Following scope.If tap density is lower than this scope, then be difficult to improve the packed density of negative electrode active material layer, can not obtain the battery of high power capacity sometimes.On the other hand, if surpass this scope, then the pore amount in the negative electrode active material tails off sometimes, is difficult to obtain preferred battery behavior sometimes.
In the present invention, tap density is as giving a definition: make sample drop on 20cm through the sieve of aperture 300 μ m 3The jolt ramming container in; Be full of the upper surface of container up to Powdered active material after; Use powder density determination device (for example, the Tap densor that seishin enterprise-like corporation makes), carry out the vibration of 1000 length of stroke 10mm; The volume in the time of thus and the weight of test portion are obtained density, and this density is defined as tap density.
2. the external lithium occlusion of element Z material (F)
So-called element Z external lithium occlusion material (F) is meant in negative pole lithium occlusion metal (A) and/or lithium occlusion alloy (B) and the material that obtains as C (carbon) (carbonaceous material (E)) compoundization of element Z.In addition, said here " compoundization " expression lithium occlusion metal (A) and/or lithium occlusion alloy (B) and carbonaceous material (E) keep the state of shape etc. through the restrained state of bonding, by the state of physical constraint, through electrostatic confinement.Here said " constraint of physics " is meant the state that lithium occlusion metal (A) and/or lithium occlusion alloy (B) are mixed in the carbonaceous material (E), connect together; So-called " constraint of static " is meant that lithium occlusion metal (A) and/or lithium occlusion alloy (B) pass through electrostatic energy attached to the state in the carbonaceous material (E).In addition, so-called " through bonding restrained state " is meant chemical bondings such as hydrogen bond, covalent bond, ionic bond.
Wherein, see that at least a portion on lithium occlusion metal (A) and/or lithium occlusion alloy (B) surface is favourable through the state that bonding has with the interface of the layer of carbonaceous material (E) from the viewpoint that reduces impedance.Here said covering; Be with the interface of part at least on the surface of carbonaceous material (E) in have chemical bond, and show that (1) covers the state on whole surface, (2) state, (3) the optionally state, the state that (4) are present in the atomic zonule of containing chemical bond on surface, cover part of coated carbon plasmid partly.
In addition, crystallinity can change on the interface continuously, also can change discontinuously.That is, the external lithium occlusion of element Z material (F) has the interface that lithium occlusion metal (A) and/or lithium occlusion alloy (B) are formed by carbonaceous material (E) covering and/or bonding, and the crystallinity at this interface is preferred discontinuous and/or change continuously.
[character of the carbonaceous material (E) of negative pole [7]]
[[composition of carbonaceous material (E)]]
(a) or carbide (b) shown in below carbonaceous material (E) is preferred especially can also contain graphite metallic substance (G) such as native graphite, Delanium simultaneously.Because the crystallinity of graphite matter (G) is very high, therefore in general, its conductivity is than graphite matter (E) height, and (E) compares with graphite matter, because it is high to improve the effect of conductivity, therefore, sees from the viewpoint that improves conductivity, preferably exists simultaneously with graphite matter (E).
(a) but be selected from coal class heavy oil, straight run class heavy oil, decompose the organic substance of the carbonization in a type black petroleum products, aromatic hydrocarbon, N cycle compound, S cycle compound, polyphenyl, organic synthesis macromolecule, natural polymer, thermoplastic resin and the heat reactive resin;
(b) but the organic substance of these carbonizations is dissolved in the small molecular organic solvent and the solution that obtains.
Here, as coal class heavy oil, preferably coal tar asphalt from the maltha to the pitch or dry distillation liquid carburetion etc.; As straight run class heavy oil, preferred atmospheric resids, decompression residual oil etc.; As decomposing a type black petroleum products, the ethylene bottom oil of by-product etc. during thermal decompositions such as preferred crude oil, naphtha; As aromatic hydrocarbon, preferred acenaphthylene, decacyclene, anthracene, phenanthrene etc.; As the N cycle compound, preferred azophenlyene, acridine etc.; As the S cycle compound, preferred thiophene, di-thiophene etc.; As polyphenyl, preferred biphenyl, terphenyl etc.; As organic polymer, preferred polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral resin, they do not dissolve handled thing, polyacrylonitrile, polypyrrole, polythiophene, polystyrene etc.; As natural polymer, polysaccharides such as preferred cellulose, lignin, mannosan, polygalacturonic acid, shitosan, sucrose etc.; As thermoplastic resin, preferred polyphenylene sulfide, polyphenylene oxide etc.; As thermosetting resin, preferred furfuryl alcohol resin, phenolic resins, imide resin etc.
Carbonaceous material (E) is preferably the carbide of above-mentioned " but organic substance of carbonization "; In addition, also preferably such " but organic substance of carbonization " is dissolved in the small molecular organic solvents such as benzene,toluene,xylene, quinoline, n-hexane and the carbide of the solution that obtains.
As above-mentioned (a) and (b), preferred especially liquid.That is, see, preferably in liquid phase, carry out carbonization from the generation and the viewpoint at the interface of occlusion metal (A) and/or lithium occlusion alloy (B).
[[rerum natura of carbonaceous material (E)]]
As the rerum natura of carbonaceous material (E), preferred satisfy simultaneously below shown in (1)～(3) in any one or multinomial.In addition, can use a kind of carbonaceous material (E) that shows such rerum natura separately, also can use more than 2 kinds with combination and ratio combination arbitrarily.
(1) X ray parameter
Rerum natura for carbonaceous material (E); D value (interfloor distance) through adopt learning the lattice plane (002 face) that X-ray diffraction that the method for shaking carries out tries to achieve (below; Brief note is " d002 ") be preferably below the 0.38nm, be preferably especially below the 0.36nm, further be preferably below the 0.35nm.If the d value is excessive, then form obviously low surface of crystallinity, impedance increases, and the effect that the acceptance of therefore charging improves diminishes, thus effect of the present invention diminishes.In addition, for lower limit, more than the 0.335nm for the theoretical value of graphite.
In addition, the crystallite size (Lc) of the material with carbon element of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is generally more than the 1nm, is preferably the above scope of 1.5nm.If be lower than this scope, then impedance increases, and the effect that the charging acceptance improves diminishes sometimes.
(2) Raman R value, Raman half breadth
Carbonaceous material (E) the Raman R value partly of using the argon laser Raman spectroscopy to measure is generally more than 0.2, is preferably more than 0.3, and more preferably more than 0.4, its upper limit is generally below 1.5, is preferably the scope below 1.2.If Raman R value is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of nonaqueous electrolytic solution, causes the gas of efficient reduction or generation to increase sometimes.
In addition, carbonaceous material (E) part is at 1580cm -1Near Raman half breadth has no particular limits, and is generally 20cm -1More than, be preferably 30cm -1More than, in addition, its upper limit is generally 140cm -1Below, be preferably 100cm -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of nonaqueous electrolytic solution, causes the gas of efficient reduction or generation to increase sometimes.
(3) real density
The real density of carbonaceous material (E) part is generally 1.4g/cm 3More than, be preferably 1.5g/cm 3More than, 1.6g/cm more preferably 3More than, further be preferably 1.7g/cm 3More than, be limited to the theoretical value 2.26g/cm of graphite on it 3Below.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.
The negative electrode active material that comprises multielement (C) that uses in the negative electrode active material of the negative pole of lithium secondary battery of the present invention [7]; Be preferably the external lithium occlusion of the element Z material (F) that occlusion metal (A) and/or lithium occlusion alloy (B) obtain with carbonaceous material (E) compoundization, also preferably further contain the carbon (C) of carbonaceous material (E) graphite metallic substance (G) in addition as element Z.
[[composition and the rerum natura of graphite metallic substance (G)]]
Example as the composition of graphite metallic substance (G); Can enumerate native graphite, Delanium and their implemented processing such as pulverizing and the material that obtains; As the rerum natura of graphite metallic substance (G), preferred satisfy simultaneously below shown in (1)～(3) in any one or multinomial.In addition, can use a kind of graphite metallic substance (G) that shows such rerum natura separately, also can use more than 2 kinds with combination and ratio combination arbitrarily.
(1) X ray parameter
For graphite metallic substance (G) part, be more than the theoretical value 0.335nm of graphite through d value (interfloor distance) that adopt to learn the lattice plane (002 face) that X-ray diffraction that the method for shaking carries out tries to achieve.Its upper limit is preferably below the 0.340nm, more preferably below the 0.338nm, is preferably below the 0.337nm especially.If the d value is excessive, then form obviously low surface of crystallinity, impedance increases, and the effect that the acceptance of therefore charging improves diminishes, thus effect of the present invention diminishes.
In addition, the crystallite size (Lc) of the graphite metallic substance (G) of trying to achieve through X-ray diffraction that adopt to learn the method for shaking is generally more than the 10nm, is preferably more than the 50nm, more preferably the above scope of 80nm.If be lower than this scope, then impedance increases, and the effect that the acceptance of therefore charging improves diminishes sometimes.
(2) Raman R value, Raman half breadth
Graphite metallic substance (G) the Raman R value partly of using the argon laser Raman spectroscopy to measure is generally more than 0.01, is preferably more than 0.10, and its upper limit is generally below 0.40, is preferably below 0.35, more preferably the scope below 0.25.If Raman R value is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of nonaqueous electrolytic solution, causes the gas of efficient reduction or generation to increase sometimes.
In addition, graphite metallic substance (G) part is at 1580cm -1Near Raman half breadth has no particular limits, and is generally 10cm -1More than, be preferably 15cm -1More than, in addition, its upper limit is generally 50cm -1Below, be preferably 40cm -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, along with the site that discharges and recharges Li entering interlayer tails off sometimes.That is, the charging acceptance reduces sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and with the reactivity increase of nonaqueous electrolytic solution, causes the gas of efficient reduction or generation to increase sometimes.
(3) real density
The real density of graphite metallic substance (G) part is generally 2.0g/cm 3More than, be preferably 2.1g/cm 3More than, 2.2g/cm more preferably 3More than, further be preferably 2.22g/cm 3More than, be limited to the theoretical value 2.26g/cm of graphite on it 3Below.If be lower than this scope, then the crystallinity of carbon is low excessively, and the initial stage irreversible capacity increases sometimes.
In the external lithium occlusion of the element Z material (F) that uses in the negative electrode active material of the negative pole of lithium secondary battery of the present invention [7]; Occlusion metal (A) and/or lithium occlusion alloy (B) are generally more than 20/80 with the mass ratio of carbonaceous material (E), are preferably more than 50/50, more preferably more than 80/20; Be preferably more than 90/10 especially; And be preferably below the 99.9/0.1, more preferably below 99/1, be preferably the scope below 98/2 especially.If surpass above-mentioned scope, then can not obtain to have the effect of carbonaceous material (E) sometimes, and if be lower than above-mentioned scope, then the effect that increases of the capacity of per unit mass diminishes sometimes.Preferred occlusion metal (A) and/or lithium occlusion alloy (B) are more than the 20 quality % with respect to whole element Z external lithium occlusion materials (F).
When containing graphite metallic substance (G), with respect to the total amount of carbonaceous material (E) and graphite metallic substance (G), graphite metallic substance (G) is preferably more than the 5 quality %, more preferably more than the 20 quality %, further is preferably more than the 50 quality %.In addition, its upper limit is preferably below the 99 quality %, more preferably below the 95 quality %.If graphite metallic substance (G) is too much, then the bonding at interface dies down, and is difficult to obtain the effect that conductivity improves sometimes, and if graphite metallic substance (G) is very few, then be difficult to sometimes obtain to contain graphite metallic substance (G) and effect that the conductivity brought improves.
In the present invention, the form of the external lithium occlusion of element Z material (F) is generally film like or Powdered.In addition; In the present invention; The negative pole that has used the film like active material such as in the manufacturing approach of back record; Can obtain through on collector body, active material layer being carried out the gas phase film forming, the negative pole of Powdered active material can through for example on collector body coated powder shape active material and adhesive etc. form active material layer.
The scope of the preferred powder property when the external lithium occlusion of element Z material (F) is Powdered is identical with the scope of the preferred powder property of the lithium occlusion material (D) that includes element Z.
[collector body of negative pole [7]]
(material)
As the material of collector body, can enumerate copper, nickel, stainless steel etc., wherein, preferably be processed into film and cheap copper easily.Copper Foil has employing rolling process rolled copper foil that makes and the electrolytic copper foil that adopts electrolysis to make, and any one can use as collector body.In addition, when the thickness of Copper Foil is thinner than 25 μ m, can use the copper alloy higher (phosphor bronze, titanium copper, Corson alloy, Cu-Cr-Zr alloy etc.) than fine copper intensity.
In the collector body that adopts the rolling process copper foil manufactured to make, because the copper crystallization arranges at rolling direction, even with closely bending or negative pole is bent into acute angle of negative pole, easy fracture not is applicable to small cylinder shape battery.Electrolytic copper foil makes as follows: for example, the drum that impregnating metal is made in being dissolved with the nonaqueous electrolytic solution of copper ion, the limit makes this drum rotation limit circulating current, and copper is separated out on the surface of drum, it is peeled off again.Can also separate out copper through electrolysis on the surface of above-mentioned rolled copper foil.Can carry out roughened or surface treatment (for example, thickness is bottom layer treatment of chromate processing, Ti etc. about several nm～1 μ m etc.) to the one or both sides of Copper Foil.
(thickness)
In the collector body substrate of being processed by Copper Foil etc., thin can make thin film cathode, and this puts from the film cathode of the high surface area more of can in the identical battery case of taking in volume, packing into; Be preferred; If but too thin, when undercapacity then, the coiling when making battery etc.; Worry that Copper Foil cuts off, therefore be preferably the thickness of 10～70 μ m.When the two sides of Copper Foil forms active material layer; Copper Foil preferably more approaches; But the viewpoint of the generation of the be full of cracks that causes from the expansion of avoiding being accompanied by the active material film that charging and discharging produces, in this case, the preferred thickness of Copper Foil is 8～35 μ m.In addition, when using Copper Foil metal forming in addition, can use preferred thickness corresponding to various metal formings, but be roughly in the scope about 10～70 μ m as collector body.
(rerum natura)
For the collector body substrate, also hope to have following rerum natura.
(1) average surface roughness (Ra)
The average surface roughness (Ra) that forms face with the active material film of the collector body substrate of the method regulation of JIS B0601-1994 record has no particular limits; But be generally more than the 0.01 μ m; Be preferably more than the 0.03 μ m; And be generally below the 1.5 μ m, be preferably below the 1.3 μ m, be preferably especially below the 1.0 μ m.
In the scope of average surface roughness (Ra) between the above-mentioned lower limit and the upper limit that makes the collector body substrate, can expect the favorable charge-discharge cycle characteristics.That is, big through being set at more than the above-mentioned lower limit with the interfacial area change of active material film, with the adaptation raising of active material film.In addition, the higher limit of average surface roughness (Ra) has no particular limits, and when average surface roughness (Ra) surpasses 1.5 μ m, is difficult to obtain the paper tinsel as the battery suitable thickness, therefore is preferably below the 1.5 μ m.
(2) hot strength
The not special restriction of the hot strength of collector body substrate is generally 50N/mm 2More than, be preferably 100N/mm 2More than, 150N/mm more preferably 2More than.So-called hot strength is meant the value that needed maximum pull obtained divided by the sectional area of test film when test film reached fracture.Hot strength among the present invention can adopt and measure the same apparatus and method of percentage elongation and measure.If the high collector body substrate of hot strength, the be full of cracks of the collector body substrate that causes owing to active material film expansion in the time of then can suppressing charge/discharge, thus can obtain good cycle characteristics.
(3) 0.2% endurance
0.2% endurance of collector body substrate has no particular limits, but is generally 30N/mm 2More than, be preferably 100N/mm 2More than, be preferably 150N/mm especially 2More than.So-called 0.2% endurance is meant that producing 0.2% plasticity (forever) is out of shape needed payload, apply the load of this size after, remove load and also can keep 0.2% distortion.0.2% endurance among the present invention can be through measuring with the identical apparatus and method of mensuration percentage elongation.If the high collector body of 0.2% endurance, the plastic deformation of the collector body substrate that causes owing to active material film expansion in the time of then can suppressing charge/discharge, thus can obtain good cycle characteristics.
[manufacturing approach of the negative electrode active material that contains multielement (C) of negative pole [7]]
The not special restriction of manufacturing approach that contains the negative electrode active material (C) (including lithium occlusion material (D) and the external lithium occlusion of the element Z material (F) of element Z) of multielement of the present invention for example, can be made through the following autofrettage of enumerating.
1. include the manufacturing approach of the lithium occlusion material (D) of element Z
< autofrettage 1 >
Any in the following material used in vapor deposition source, sputtering source or spraying plating source:
(i) composition of Si, element Z and element M when y=0 or
Figure BDA0000087738240001451
(wherein, be the composition of Si and element Z);
The (ii) mixture of Si, element Z and element M when y=0 or (wherein, be the mixture of Si and element Z);
(iii) separately simple substance (each simple substance also can be the gas that contains each element) of Si, element Z and element M when y=0 or
Figure BDA0000087738240001453
(wherein, be Si and element Z simple substance separately);
The (iv) simple substance of the composition of Si and element Z or mixture and element M (also can be the gas that contains M);
(gas when y=0 or
Figure BDA0000087738240001461
(wherein, be the gas that contains Si and element Z) that v) contains Si, element Z and element M;
(the vi) composition or the mixture of Si simple substance, element Z and element M;
(the vii) simple substance of the composition of Si and element M or mixture and element Z (also can be the gas that contains M),
And utilize vapour deposition method and/or sputtering method and metallikon simultaneously with Si, element Z and element M when y=0 or
Figure BDA0000087738240001462
(wherein, be Si and element Z) on above-mentioned collector body substrate, form 1～30 μ m thickness, be preferably the film of the thickness of record in one of the thickness of active material film.
(raw material)
Si simple substance raw material as vapor deposition source, sputtering source or spraying plating (dissolve and penetrate) source (following suitably be called sometimes " raw material ") for example can use crystallinity Si, amorphous Si etc.As the Z raw material, can use C, N element.In addition, element Z can use the multiple element more than 2 kinds simultaneously so long as satisfy the element of above-mentioned project and get final product.
In the raw material; As the composition of (i) Si, element Z and element M (wherein; When y=0 or
Figure BDA0000087738240001463
is the composition of Si and element Z); Can use and make up Si, element Z and element M; The unification compound that has perhaps made up Si and element Z and formed perhaps also can be processed multiple compound and use.In addition, the form of these Si, Z raw material, M raw material for example can be made into Powdered, graininess, use such as coccoid, block, tabular.
At general formula SiZ xM yIn; Y ≠ 0 and when containing element M; Element M can be used a kind of in the element that is selected from periodic table 2 families, 4 families, 8 families, 9 families, 10 families, 11 families, 13 families, 14 families, 15 families and 16 families beyond Si and the element Z or more than 2 kinds; Preferred Ti, Zr, W, O, the Co element of using more preferably uses the O element.
(one-tenth embrane method)
As the formation method of active material film, can enumerate gas phase and become embrane method, particularly, can enumerate vapour deposition method (vacuum vapour deposition, CVD method, ion plating method), sputtering method, metallikon (flame spraying, plasma spraying process) etc.Can also sputtering method and vapour deposition method, sputtering method and metallikon be made up film forming.
The formation method of following anticathode active material film describes.
A. sputtering method
Sputtering method is the active material and the collision of collector body substrate that under reduced pressure utilize plasma to make to be sent by the target that contains above-mentioned raw materials, pile up and form film.If the employing sputtering method, the active material film that then forms and the interface state of collector body substrate are good, and the active material film is also high for the adaptation of collector body.
As applying method for the sputtering voltage of target, can use any one of direct voltage, alternating voltage, at this moment, the collector body substrate is applied negative bias voltage in fact, can control the collision energy of the ion that derives from plasma.The final vacuum that begins to form in the preceding chamber of film is generally below the 0.1Pa to prevent to sneak into impurity.
As sputter gas, use inert gases such as Ne, Ar, Kr, Xe.Wherein, consider, preferably use argon gas from aspects such as sputtering yields.In addition, compound S iZ xM yIn element Z when being N, in above-mentioned inert gas, having the nitrogen of trace simultaneously is preferred on making.Usually, sputter gas pressure is about 0.05～70Pa.Collector body substrate when forming the active material film through sputtering method can wait through water cooling or heater controls temperature.As the temperature range of collector body substrate, be generally room temperature～900 ℃, but be preferably below 150 ℃.Film forming speed when forming the active material film through sputtering method is generally 0.01～0.5 μ m/ minute.
And, before forming the active material film, can come the collector body substrate surface is carried out etching through reverse sputtering or other pre-treatments such as Cement Composite Treated by Plasma.Such pre-treatment is effective for the raising as the adaptation of the removing of the pollutant of the copper foil surface of collector body substrate or oxide-film, active material film.
B. vacuum vapour deposition
Vacuum vapour deposition is above-mentioned raw materials fusion, the evaporation that makes as active material, thereby is deposited in the method on the collector body substrate, and in general, this method has that compare with sputtering method can be with the film forming advantage of higher film forming speed.From the viewpoint of the formation time of the active material film of seeking to shorten the regulation thickness, vacuum vapour deposition is compared with sputtering method, flexible Application advantageously aspect manufacturing cost.As its concrete method, can enumerate induction heating, electrical resistance heating, electron beam heating vapour deposition method etc.Induction heating is in the vapor deposition crucible of graphite etc., to make deposition material heating and melting and evaporation and film forming through induced current; Electrical resistance heating is that the heating current through energising makes deposition material heating and melting and evaporation and film forming in vapor deposition boat etc.; Electron beam heating vapor deposition is through electron beam the deposition material heating and melting also to be evaporated and film forming.
Atmosphere gas as vacuum vapour deposition generally uses vacuum.In addition, compound S iZ xM yIn element Z when being N, can the nitrogen of trace be imported with inert gas and reduce pressure, under vacuum, form SiZ simultaneously xM yThe final vacuum that begins to form in the preceding chamber of film is generally below the 0.1Pa to prevent to sneak into impurity.
Collector body substrate when forming the active material film through vacuum vapour deposition can be through control temperature such as heaters.As the temperature range of collector body substrate, be generally room temperature～900 ℃, but be preferably below 150 ℃.Film forming speed when forming the negative electrode active material film through vacuum vapour deposition is generally 0.1～50 μ m/ minute.
In addition, with the situation of sputtering method likewise, before piling up the active material film on the collector body substrate, can come the collector body substrate surface is implemented etch processes through carrying out ion exposure with ion gun etc.Through such etch processes, can further improve the adaptation of substrate and active material film.In addition, when forming film,, can further improve the adaptation of active material film for the collector body substrate through making the collision of ion and collector body substrate.
The C.CVD method
The CVD method is through gas-phase chemical reaction the above-mentioned raw materials as active material to be deposited on the collector body substrate.In general; The CVD method has following characteristic: owing to flow into the chemical compound gas in the control reative cell through gas; Therefore various materials can be synthesized to high-purity,, hot CVD method, plasma CVD method, optical cvd method, cat-CVD method etc. can be enumerated as its concrete method.The hot CVD method is in the reaction vessel of unstrpped gas with carrier gas or reacting gas import to heating about 1000 ℃ after of halogen compound that vapour pressure is high, makes it produce thermal chemical reaction and forms film.Plasma CVD method is to use plasma to substitute the method for heat energy; Optical cvd is to use luminous energy to substitute the method for heat energy.The cat-CVD method is a catalytic chemical vapor deposition technique, forms film through using unstrpped gas with the decomposition reaction that contacts of heatable catalyst.
In the unstrpped gas of using in the CVD method, be SiH as the elements Si source 4, SiCl 4Deng; As element Z source is NH 3, N 2, BCl 3, CH 4, C 2H 6, C 3H 8Deng.
D. ion plating method
Ion plating method is above-mentioned raw materials fusion, the evaporation that makes as active material, under plasma with the evaporation particle ionization with excite, film forming securely on the collector body substrate thus.Specifically, as the method that makes raw materials melt, evaporation, can enumerate induction heating, electrical resistance heating, electron beam heating vapour deposition method etc.; As ionization and the method that excites, can enumerate priming reaction vapour deposition method, many cathode primary electron irradiation, high frequency excitation method, HCD method, ion cluster bundle method (Network ラ ス タ one イ オ Application PVC one system method), multi sphere method etc.In addition, can method and the ionization of evaporation above-mentioned raw materials and the method that excites suitably be selected to make up and carry out.
E. metallikon
Metallikon is to make as the above-mentioned raw materials fusion of active material or softening through heating, forms finely particulate and quickens, thereby make particle solidify, be deposited on the collector body substrate.As its concrete method, can enumerate flame-spray processes, arc spraying method, direct-current plasma metallikon, RF plasma spraying method, laser metallikon etc.
F. the combination of sputtering method and vapour deposition method
Utilize the advantage to the strong film forming adaptation of collector body substrate of advantage and sputtering method of the high film forming speed of vapour deposition method; For example; Form the 1st thin layer through sputtering method; Form the 2nd thin layer at a high speed through vapour deposition method then, can form thus and the excellent interface zone of the adaptation of collector body substrate, form the active material film with high film forming speed simultaneously.Utilize the combined method of the mixing of such film build method, can make the film cathode of charge/discharge capacity height and excellent charge efficiently.
Sputtering method and vapour deposition method made up form the active material film and preferably keep reducing pressure atmosphere gas and carry out continuously.This is owing to form the 1st thin layer and the 2nd thin layer continuously through not being exposed under the atmosphere, can prevent to sneak into impurity.For example, preferably use following film forming device: in same vacuum environment, the collector body substrate is moved, carry out sputter and vapor deposition simultaneously successively.
In the present invention; When on the two sides of collector body substrate, forming the active material film through such one-tenth embrane method; Forming active material thin layer (also can be the combination of above-mentioned the 1st thin layer and the 2nd thin layer) on the one side of collector body substrate and on the another side of collector body substrate, forming active material thin layer (also can be the combination of above-mentioned the 1st thin layer and the 2nd thin layer), preferably under the state that keeps decompression atmosphere gas, carry out continuously.
< autofrettage 2 >
Following mutual-through type SiZ xM yManufacturing approach when middle element Z is C describes.
Any in the following substances used in vapor deposition source, sputtering source or spraying plating source:
(i) composition of Si, C and element M when y=0 or
Figure BDA0000087738240001491
(wherein, be the composition of Si and C);
The (ii) mixture of Si, C and element M when y=0 or
Figure BDA0000087738240001492
(wherein, be the mixture of Si and C);
(iii) separately simple substance of Si, C and element M when y=0 or
Figure BDA0000087738240001493
(wherein, be Si and C simple substance separately);
The (iv) simple substance of the composition of Si and C or mixture and element M (also can for containing the gas of M);
(gas when y=0 or
Figure BDA0000087738240001494
(wherein, be the gas that contains Si and C) that v) contains Si, C and element M;
(the vi) composition of Si simple substance and C and element M or mixture;
(the vii) composition of Si and element M or mixture and C simple substance,
And utilize vapour deposition method and/or sputtering method and metallikon simultaneously with Si, C and element M when y=0 or
Figure BDA0000087738240001501
(wherein, be Si and C) on above-mentioned collector body substrate, form 1～30 μ m thickness, be preferably the film of the thickness of putting down in writing in the thickness item of active material film.
(raw material)
Si raw material as vapor deposition source or sputtering source (following suitably be called sometimes " raw material ") for example can use crystallinity Si, amorphous Si etc.As the C raw material, for example can use material with carbon elements such as native graphite, Delanium.As the M raw material, be generally the element of periodic table 2 families, 4 families, 8 families, 9 families, 10 families, 11 families, 13 families, 14 families, 15 families and 16 families beyond Si and the element Z, preferably use Ti, Zr, W, O, Co element, especially preferably use the O element.
In the raw material,, can use Si, C and element M to make up and the unification compound of formation, perhaps also can process multiple compound and use as the composition of (i) Si, C and element M.In addition, the form of these Si, C, M raw material for example can be made into Powdered, graininess, use such as coccoid, block, tabular.In addition, the oxide that element M can be processed nitride, Si or the C of Si or C uses, and for the O that exists as gas under the normal temperature etc., it is preferred in Si, C film forming, co-existing in the manufacturing as unstrpped gas O etc.
(one-tenth embrane method)
Use with above-mentioned autofrettage 1 same become embrane method.
A. sputtering method
As sputter gas, use inert gases such as Ne, Ar, Kr, Xe.Wherein, consider, preferably use argon gas from aspects such as sputtering yields.In addition, general formula SiC xM yIn M element when being O, the oxygen of coexistence trace is preferred on making respectively in above-mentioned inert gas.Usually, sputter gas pressure is about 0.05～70Pa.
B. vacuum vapour deposition
Atmosphere gas as vacuum vapour deposition generally uses vacuum.In addition, general formula SiC xM yIn element M when being O, can be respectively the oxygen of trace be imported with inert gas, reduce pressure simultaneously, thereby under vacuum, form Si/C/M simultaneously.
The C.CVD method
In the unstrpped gas that the CVD method is used, be SiH as the elements Si source 4, SiCl 4Deng; As the Elements C source is CH 4, C 2H 6, C 3H 8Deng.
< autofrettage 3 >
Following mutual-through type SiZ xM yMiddle element Z is that C, the manufacturing approach when element M is O describe.
Any in the following substances used in vapor deposition source, sputtering source or spraying plating source:
(I) composition of Si and C;
(II) mixture of Si and C;
(III) Si and C simple substance separately,
Perhaps
(IV) contain the gas of Si and C,
The oxygen concentration of when film forming (be in residual gas in a vacuum) is under 0.0001～0.125% the atmosphere gas in film forming gas, utilize vapour deposition method and/or sputtering method and metallikon simultaneously with Si and C on above-mentioned collector body substrate, form 1～30 μ m thickness, be preferably the film of the thickness of putting down in writing in the thickness item of active material film.
(raw material)
Si raw material as vapor deposition source, sputtering source or the spraying plating source of raw material for example can use crystallinity Si, amorphous Si etc.As the C raw material, for example can use material with carbon elements such as native graphite, Delanium.As the oxygen in the film forming gas, the gas that oxygen etc. is contained the O element uses separately or uses with the inert gas combination.The form of these Si, C raw material for example can be made into Powdered, graininess, use such as coccoid, block, tabular.In addition, to co-exist in the manufacturing in Si, C film forming as unstrpped gas be preferred to oxygen.
(one-tenth embrane method)
Use with above-mentioned autofrettage 1 same become embrane method.
(oxygen concentration during film forming)
When vapor deposition and/or sputter and spraying plating in film forming gas the oxygen concentration of when film forming (in the vacuum be in the residual gas) be generally more than 0.0001%, and be generally below 0.125%, be preferably below 0.100%, more preferably below 0.020%.If the oxygen concentration that contains in the film forming gas surpasses this scope, then the amount of the element O in the Si/C/O film increases, and the reactivity increase with nonaqueous electrolytic solution causes the reduction of efficiency for charge-discharge sometimes.If oxygen concentration is very few, then can not form the Si/C/O film sometimes.
And; As the oxygen concentration in the film forming gas; For example, can be through using the sub-Off イ Le タ of quadrupole mass filter (four
Figure BDA0000087738240001511
) mass spectrum of analyzing film forming gas obtains.In addition, use to coexist when the argon gas of oxygen is arranged as film forming gas, can measure this argon gas through oxygen analyzer and try to achieve.
< autofrettage 4 >
Following mutual-through type SiZ xM yIn element Z be N and y=0 or The time manufacturing approach describe.
Any in the following substances used in vapor deposition source, sputtering source or spraying plating source:
(I) Si simple substance;
(II) contain the composition of Si;
(III) contain the mixture of Si,
Or
(IV) contain the gas of Si,
The nitrogen concentration of when film forming (be in residual gas in a vacuum) is under 1～22% the atmosphere gas in film forming gas, utilize vapour deposition method and/or sputtering method and metallikon simultaneously with Si and N on above-mentioned collector body substrate, form 1～30 μ m thickness, be preferably the film of the thickness of putting down in writing in the thickness item of active material film.
(raw material)
Si simple substance raw material as vapor deposition source, sputtering source or the spraying plating source of raw material for example can use crystallinity Si, amorphous Si etc.As the N in the film forming gas, the gas that nitrogen etc. is contained the N element uses separately or uses with the inert gas combination.The form of these Si etc. for example can be made into Powdered, graininess, use such as coccoid, block, tabular.In addition, to co-exist in the manufacturing in the Si film forming as unstrpped gas be preferred to nitrogen.
(one-tenth embrane method)
Use with above-mentioned autofrettage 1 same become embrane method.
(nitrogen concentration during film forming)
When vapor deposition and/or sputter and spraying plating in film forming gas the nitrogen concentration of when film forming (in the vacuum be in the residual gas) be generally more than 1%, and be generally below 22%, be preferably below 15%, more preferably below 10%.If the nitrogen concentration that contains in the film forming gas surpasses this scope, then SiN xElement N in film amount increases, and produces and does not participate in the silicon nitride that discharges and recharges, the reduction of guiding discharge capacity sometimes.If nitrogen concentration is very few, then can not form the SiN that contains N sometimes xFilm and cause the reduction of cycle characteristics.In addition, as the nitrogen concentration in the film forming gas, for example, can obtain through the mass spectrum that uses quadrupole mass filter to analyze film forming gas.
2. the method for making of the external lithium occlusion of element Z material (F)
< autofrettage 5 >
With lithium occlusion metal (A) and/or lithium occlusion alloy (B) with carbonaceous material (E) but the composition item described in the organic substance of carbonization mix; And with organic substance heating, decomposition; Pass through solid phase and/or liquid phase and/or gas phase and carry out carbonization, form carbonaceous material (E), obtain compound.Again to this particle pulverize, classification, making the volume reference average grain diameter is suitable value.
(raw material)
Be generally below the 100 μ m as the lithium occlusion metal (A) of raw material and/or the volume reference average grain diameter of lithium occlusion alloy (B), be preferably below the 10 μ m, more preferably below the 1 μ m, it is limited to the scope more than the 1nm down.If surpass the upper limit, the expansion when then being difficult to relax charging, the circulation conservation rate reduces sometimes.In addition,, then be difficult to pulverize, cause last, loss economically of time sometimes if be lower than lower limit.In addition, as the raw material of carbonaceous material (E) as stated, but be preferably when carbonization material through liquid phase.
< autofrettage 6 >
Lithium occlusion metal (A) and/or lithium occlusion alloy (B) are mixed with graphite matter (G); Mix again described in the composition item of carbonaceous material (E) can carbonization organic substance, and with the organic substance heating, decompose, carry out carbonization with liquid phase; Form carbonaceous material (E), obtain compound.Again to this particle pulverize, classification, making the volume reference average grain diameter is suitable value.
(raw material)
Raw material is identical with < autofrettage 5 >.
< autofrettage 7 >
Lithium occlusion metal (A) and/or lithium occlusion alloy (B) are mixed with graphite matter (G); Mix again described in the composition item of carbonaceous material (E) can carbonization organic substance, and with the organic substance heating, decompose, carry out carbonization with solid phase; Through forming carbonaceous material (E) mutually, obtain compound.Further to this particle pulverize, classification, making the volume reference average grain diameter is suitable value.
(raw material)
Raw material is identical with < autofrettage 5 >.
< autofrettage 8 >
Lithium occlusion metal (A) and/or lithium occlusion alloy (B) are mixed with graphite matter (G); Mix again described in the composition item of carbonaceous material (E) can carbonization organic substance, and with the organic substance heating, decompose, carry out carbonization with gas phase; Through forming carbonaceous material (E) mutually, obtain compound.Further to this particle pulverize, classification, making the volume reference average grain diameter is suitable value.
(raw material)
Raw material is identical with < autofrettage 5 >.
[electric polarization of the Powdered active material of negative pole [7]]
The manufacturing of negative pole can be carried out according to conventional method; For example; As stated, can be through in negative electrode active material, adding adhesive, solvent, add thickener, electric conducting material, packing material etc. as required and process slurry; Be coated on the collector body it and after carrying out drying, suppress and form.The thickness of the negative electrode active material layer of each face in the stage before the electrolyte implantation step of battery be generally 5 μ m above, be preferably 10 μ m above, more preferably more than the 15 μ m, be limited to below the 150 μ m on it, be preferably below the 120 μ m, more preferably below the 100 μ m.If surpass this scope, owing to nonaqueous electrolytic solution is difficult to soak into to the collector body near interface, so the high current density charge-discharge characteristic reduces sometimes.In addition, if be lower than this scope, then collector body increases for the volume ratio of negative electrode active material, and the capacity of battery reduces sometimes.In addition, can the moulding of negative electrode active material roller be formed plate electrode, perhaps form mosaic electrode through compression forming.
Operable adhesive, thickener etc. are same as described above.
< negative pole [8] >
In the face of the negative pole [8] that uses in the lithium secondary battery of the present invention describes, said negative pole [8] contains the negative electrode active material more than 2 kinds of different in kind as negative electrode active material down.
[negative electrode active material of negative pole [8]]
The negative electrode active material that uses in the following anticathode [8] describes.
The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [8] is characterised in that, contains the negative electrode active material more than 2 kinds of different in kind.
Wherein said " different in kind " not only is meant with X-ray diffraction parameter, median particle diameter, draw ratio, BET specific area, orientation ratio, Raman R value, tap density, real density, micropore distribution, circularity, ash amount etc. is that the powder shape of representative is different with powder property; The formation that also comprises materials such as " the composite carbonaceous material that contains the carbonaceous material that crystallinity is different more than 2 kinds ", " the different orientation carbon complex that contains the different carbonaceous material of orientation more than 2 kinds " is different, or processed condition of different such as " the anticathode active material is implemented heat treatment ", " the anticathode active material is implemented the mechanics energy process ".
[differences of shape, rerum natura etc.]
Wherein, the negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [8] can be kept the low temperature power output through containing the different negative electrode active material more than 2 kinds of volume reference average grain diameter (median particle diameter), can improve cycle characteristics simultaneously.Poor as volume reference average grain diameter (median particle diameter), exist usually 1 μ m above, preferably exist 2 μ m above, more preferably have above poor of 5 μ m.As the upper limit, be generally below the 30 μ m, be preferably below the 25 μ m.If surpass this scope, the particle diameter that then median particle diameter is big has excessive trend, therefore when electrode is made, might produce the problems such as wire drawing of coated face.On the other hand, if be lower than this scope, then might be difficult to show the effect of mixing 2 kinds of negative electrode active materials.
In addition, for the negative electrode active material that uses in the negative pole [8] of lithium secondary battery of the present invention, because reason same as described above, the uneven material of volume reference particle size distribution also can show good characteristic.So-called " the volume reference particle size distribution is uneven "; Be meant the volume reference particle size distribution when transverse axis is logarithmic scale; When being the center with volume reference average grain diameter (median particle diameter); Do not form left-right symmetric, as non-symmetrical degree, the Z value of representing with following formula (1) is generally more than the 0.3 μ m, is preferably more than the 0.5 μ m, more preferably more than the 1 μ m.If Z is lower than this value, then might be difficult to obtain effect through the uneven cycle characteristics raising that is brought of particle size distribution.
Z=| (mould footpath)-(median particle diameter) | (1)
In the formula (1), the unit of mould footpath and median particle diameter all is " μ m ", " || " expression absolute value.
In the present invention; Volume reference average grain diameter (median particle diameter) and mould directly are defined as following value: negative electrode active material is dispersed in the 0.2 quality % aqueous solution (about 1mL) of polyoxyethylene (20) Span-20 as surfactant, uses laser diffraction formula particle size distribution meter (the hole field makes the LA-700 of institute's manufactured) and the value of mensuration." median particle diameter " is also referred to as d usually 50This particle diameter when referring under volume reference larger side and smaller side equivalent when powder is divided into two parts by certain particle diameter; " mould footpath " refers in the particle size distribution of volume reference; The particle diameter of the maximum that expression distributes, any one all be that the hole field makes the value that is called " median particle diameter ", " mould directly " among the LA-700 of institute's manufactured, is illustrated respectively on the device.
In addition, be the negative electrode active material below the 10 μ m through at least a use median particle diameter that makes negative electrode active material, can keep the low temperature power output, obtain the raising effect of cycle characteristics simultaneously, see it is preferred from this aspect.Be preferably especially below the 8 μ m.Median particle diameter be negative electrode active material below the 10 μ m with respect to whole negative electrode active materials, use in the scope particularly preferably in 0.5～10 quality %.
In addition; The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [8]; Through containing the different negative electrode active material more than 2 kinds of Raman R value that adopts the argon laser Raman spectroscopy to measure, can keep cycle characteristics, improve the low temperature power output simultaneously.Poor as Raman R value is generally more than 0.1, is preferably more than 0.2, more preferably more than 0.3, as the upper limit, is generally below 1.4, is preferably below 1.3, the scope below 1.2 more preferably.If be lower than this scope, then be difficult to obtain the effect of bringing owing to the difference of Raman R value sometimes.On the other hand, if surpass this scope, then owing to the high part of Raman R value, irreversible capacity increases sometimes.
In the present invention; The mensuration of Raman spectrum is carried out as follows: use raman spectroscopy device (for example, the raman spectroscopy device of Japanese beam split manufactured), sample is dropped into naturally measure in the container; Carrying out sample fills; The mensuration process is, to the irradiation of the specimen surface in container argon laser, make simultaneously this container with the face of laser vertical in rotate.For the Raman spectrum that obtains, measure 1580cm -1Peak P AIntensity I AAnd 1360cm -1Peak P BIntensity I B, calculate its strength ratio R (R=I B/ I A), it is defined as the Raman R value of graphite matter carbon particle.In addition, measure the Raman spectrum obtain at 1580cm -1Peak P AHalf breadth, it is defined as the Raman half breadth of graphite matter carbon particle.
In addition, the Raman condition determination here is following.
Argon laser wavelength: 514.5nm
Laser power on the sample: 15～25mW
Resolution: 10～20cm -1
Measurement range: 1100cm -1～1730cm -1
Raman R value, half breadth analysis: background is handled
Smooth treatment: simple average, convolution 5 points
In addition, as the employed negative electrode active material of negative electrode active material that uses in the negative pole [8] of lithium secondary battery of the present invention, its 1580cm -1Not special qualification of Raman half breadth, but be generally 10cm -1More than, be preferably 15cm -1More than, in addition, its upper limit is generally 150cm -1Below, be preferably 140cm -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, and the low temperature power output reduces sometimes.On the other hand, if surpass this scope, then because the crystallinity of particle surface reduces, irreversible capacity increases sometimes.
In addition, as the employed negative electrode active material of negative electrode active material that uses in the negative pole [8] of lithium secondary battery of the present invention,, also can keep cycle characteristics and improve the low temperature power output even contain the different negative electrode active material more than 2 kinds of crystallinity.So-called crystallinity is meant the laminated construction such as thickness, spacing of repetitive structure of laminated body of the hexagonal wire side of carbon here.The concrete physics value that the expression crystallinity is different is not special to be limited, and interplanar distance, crystallite size etc. are for example arranged, different in the negative electrode active material more than 2 kinds that preferably they use in lithium secondary battery of the present invention.If the difference of crystallinity is too small, then be difficult to obtain the effect of bringing through mixing sometimes.
The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [8]; Through containing the different negative electrode active material more than 2 kinds of interplanar distance (d002) of (002) face that adopts wide-angle x-ray diffraction mensuration, can keep cycle characteristics and improve the low temperature power output.Poor as interplanar distance (d002); Be generally 0.0005nm above, be preferably 0.001nm above, more preferably 0.003nm above, further be preferably more than the 0.004nm, its upper limit is generally below the 0.05nm, is preferably below the 0.04nm, more preferably below the 0.03nm, further be preferably the scope below the 0.02nm.If be lower than this scope, then be difficult to sometimes obtain owing to the different effects of bringing of crystallinity.On the other hand, if surpass this scope, then owing to the low part of crystallinity, irreversible capacity increases sometimes.The interplanar distance (d002) of (002) face that said employing wide-angle x-ray diffraction is measured among the present invention is meant the d value (interfloor distance) of the lattice plane (002 face) of trying to achieve through the X-ray diffraction that adopts the method for shaking to carry out.
In addition; The negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [8]; Learn the different negative electrode active material more than 2 kinds of crystallite size (Lc) that the method for shaking is tried to achieve with X-ray diffraction through containing to adopt, can keep cycle characteristics and improve the low temperature power output.The difference of the crystallite size (Lc) of trying to achieve with X-ray diffraction through the method for shaking be generally 1nm above, be preferably 10nm above, more preferably more than the 50nm.If be lower than this scope, then be difficult to sometimes obtain because the different effects of being brought of crystallite size.
In addition, the negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [8] through containing the different negative electrode active material more than 2 kinds of real density, can be kept cycle characteristics and improve the low temperature power output.Poor as real density is generally 0.03g/cm 3More than, be preferably 0.05g/cm 3More than, 0.1g/cm more preferably 3More than, further be preferably 0.2g/cm 3More than, its upper limit is generally 0.7g/cm 3Below, be preferably 0.5g/cm 3Below, 0.4g/cm more preferably 3Following scope.If be lower than this scope, then be difficult to sometimes obtain owing to the different effects of bringing of real density.On the other hand, if surpass this scope, then owing to the low part of real density, irreversible capacity increases sometimes.
Alleged real density is defined as the value of measuring through the liquid phase displacement method (hydrometer method) of using butanols among the present invention.
In addition, the negative electrode active material that uses among the present invention also can be kept the low temperature power output and improve cycle characteristics through containing the different negative electrode active material more than 2 kinds of circularity.Poor as circularity is generally more than 0.01, is preferably more than 0.02, more preferably more than 0.03, and its upper limit is generally below 0.3, is preferably below 0.2, the scope below 0.1 more preferably.If be lower than this scope, then be difficult to sometimes obtain because the different effects of being brought of circularity.On the other hand, if surpass this scope, then because the low part of circularity during electric polarization, produces problems such as wire drawing sometimes.
Said circularity defines with following formula among the present invention.
Circularity=(having girth)/(perimeter of particle projection of shape) with particle projection of shape equivalent circular of the same area
Use the following value of measuring as the value of circularity: (for example use flow-type particle picture analytical equipment; The FPIA of Sysmex Industrial manufactured); About 0.2g sample is scattered in the 0.2 quality % aqueous solution (about 50mL) of polyoxyethylene (20) Span-20 as surfactant; Behind the ultrasonic wave with 1 minute 28kHz of the power output of 60W irradiation, specifying 0.6～400 μ m is detection range, and the particle of particle diameter 3～40 mu m ranges is measured.
In addition, the negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [8] through containing the different negative electrode active material more than 2 kinds of tap density, can be kept the low temperature power output and improve cycle characteristics.Poor as tap density is generally 0.1g/cm 3More than, be preferably 0.2g/cm 3More than, 0.3g/cm more preferably 3More than.If be lower than this scope, then be difficult to sometimes obtain through mixing the effect that the tap density material different is brought.
In the present invention, tap density is as giving a definition: make sample pass through the sieve of aperture 300 μ m, make sample fall into 20cm 3The jolt ramming container in, be full of the upper surface of container to sample after, (for example use the powder density determination device; The Tap densor that seishin enterprise-like corporation makes); Carry out the vibration of 1000 length of stroke 10mm, the weight bulk density of volume in the time of thus and test portion should be worth as tap density.
In addition, the negative electrode active material that uses in the negative pole of lithium secondary battery of the present invention [8] through containing the different negative electrode active material more than 2 kinds of BET specific area, can be kept cycle characteristics and improve the low temperature power output.Poor as the BET specific area is generally 0.1m 2/ g is above, be preferably 0.5m 2/ g is above, 1m more preferably 2More than/the g, its upper limit is generally 20m 2Below/the g, be preferably 15m 2Below/the g, 12m more preferably 2Scope below the/g.If be lower than this scope, then be difficult to sometimes obtain through mixing the effect that BET specific area material different is brought.On the other hand, if surpass this scope, then owing to the big part of BET specific area, irreversible capacity increases sometimes.
In the present invention; The BET specific area is defined as following value: use surface area meter (the full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation 350 ℃ to test portion carry out 15 minutes predrying; Using then and correctly being adjusted into nitrogen is 0.3 nitrogen helium gas mixture body with respect to atmospheric relative pressure value, the value of measuring through the nitrogen absorption BET1 point method that adopts the gas flow method to carry out.
As the blending ratio of different active material more than 2 kinds that uses in the negative pole [8] of lithium secondary battery of the present invention; The shared ratio of a kind of negative electrode active material is generally more than the 0.1 quality %, is preferably more than the 1 quality %, more preferably more than the 10 quality %, further be preferably more than the 20 quality % with respect to total amount, and its upper limit is generally below the 99.9 quality %, is preferably below the 99 quality %, more preferably below the 90 quality %, further be preferably the scope below the 80 quality %.If outside this scope, then be difficult to sometimes obtain through containing the different effects that negative electrode active material brought more than 2 kinds.
In addition, contain the machining object of native graphite and/or native graphite in 2 kinds of wherein different negative electrode active materials at least a, see it is preferred from the high aspect of cost performance.
Native graphite is according to its proterties; Be classified as flaky graphite (Flake Graphite), flaky graphite (Crystalline (Vein) Graphite), soil graphite (Amorphous Graphite) (referring to " powder body technology technology is integrated "; One in the graphite of ((strain) industrial technology center, clear and distribution in 49 years); And " HAND BOOK OF CARBON, GRAPHITE, DIAMOND AND FULLERENES ", (Noyes Publications distribution)).Degree of graphitization is the highest with flaky graphite, is 100%, then is flaky graphite, be 99.9%, and soil graphite is low to moderate 28%.Flaky graphite as native graphite originates from Madagascar, China, Brazil, Ukraine, Canada etc.; Flaky graphite mainly originates from Sri Lanka.The main product ground of soil graphite is the Korea peninsula, China, Mexico etc.In these native graphites, the general particle diameter of soil graphite is little and purity is low.In contrast, flaky graphite, flaky graphite can preferably use owing to have advantages such as degree of graphitization height, impurity level are low in the present invention.
[difference that negative pole [8] is handled]
The negative electrode active material that uses among the present invention can be kept cycle characteristics and improve the low temperature power output through containing the different negative electrode active material more than 2 kinds of processed.As the processing method of native graphite, can enumerate and apply heat-treating methods, apply the method for mechanics energy process etc.A heat treated example is described below.
[[heat treatment temperature]]
As the heat treatment temperature of negative electrode active material, be generally more than 600 ℃, be preferably more than 1200 ℃, more preferably more than 2000 ℃, further be preferably more than 2500 ℃, be preferably more than 2800 ℃ especially.The upper limit is generally below 3200 ℃, is preferably below 3100 ℃.If temperature conditions is lower than this scope, then the crystallization reparation on the surface of native graphite particle is insufficient sometimes.On the other hand, if surpass above-mentioned scope, then the distillation amount of graphite increases sometimes easily.The negative electrode active material that uses among the present invention preferably contains the different negative electrode active material more than 2 kinds of heat treatment temperature.
[[heat treatment method]]
Heat treatment is through realizing through a said temperature scope.Temperature conditions is remained on not special qualification of retention time of above-mentioned scope, but be generally the time of being longer than for 10 seconds, and be below 168 hours.
Heat treatment is being carried out under the non-active gas atmosphere such as nitrogen or under the non-oxidizable atmosphere that the gas that is produced by the raw material native graphite forms usually.But the stove for being embedded in type in the coal dust (thin pitch sintered carbon) is mixed with atmosphere at first sometimes.In this case, non-active gas atmosphereization fully.As the device that uses in the heat treatment, not special the qualification for example can be used shuttle-type stove, tunnel furnace, electric furnace, coke baking furnace, rotary furnace, directly switch on stove, acheson furnace, resistance-heated furnace, induction heater etc.The negative electrode active material that uses among the present invention preferably contains the different negative electrode active material more than 2 kinds of heat treatment method.
In addition, except above-mentioned each processing, can also carry out various processing such as hierarchical processing.Hierarchical processing is in order to obtain target grain size, to remove meal and micro mist and the processing carried out.Device as using in the hierarchical processing has no particular limits, and for example, under the situation of dry type screening, can use gyratory sifter, rock type sieve, rotary type sieve, oscillatory type sieve etc.; Under the situation of dry type air current classifying, can use gravity type grader, inertia force formula grader, centrifugal force type grader (sizer, cyclone separator) etc.; Under the situation of wet screening, can use mechanical type wet classifier, hydraulic classifier, settling classifier, centrifugal wet classifier etc.Hierarchical processing can be carried out before heat treatment, also can for example carry out after the heat treatment at other times.In addition, can also omit hierarchical processing itself.The negative electrode active material that uses among the present invention preferably contains the different negative electrode active material more than 2 kinds of hierarchical processing condition.
The mechanics energy process different negative electrode active material 2 kind or more of the negative electrode active material that uses among the present invention through stating after containing can be kept cycle characteristics and improve the low temperature power output.An example of mechanics energy process is described below.
[[mechanics energy process]]
Carrying out the mechanics energy process, to make the volume average particle size ratio before and after handling be below 1.So-called " the volume average particle size ratio before and after handling " is the value that the volume average particle size after handling obtains divided by the volume average particle size before handling.It is below 1 that the mechanics energy process of carrying out in order to make the raw material before the heat treatment in the present invention, preferably makes the average grain diameter ratio before and after handling.The mechanics energy process is to reduce particle size so that the average grain diameter ratio of powder particle before and after handling is below 1, controls shape of particle simultaneously and the processing carried out.In the engineering unit operation that pulverizing, classification, mixing, granulation, surface modification, reaction etc. can effectively utilize in seed designs, the mechanics energy process belongs to pulverization process.
The so-called pulverizing is meant material is applied power, and its size is reduced with the particle diameter of regulating material or particle size distribution, fillibility.Pulverization process is classified according to kind, the processing form of the power that material is applied.The power that material is applied roughly is divided into following 4 kinds: (1) beats that power (impulsive force), (2) crushing force (compression stress), (3) grind power (grinding power), the power of scraping (shearing force) is cut in (4).On the other hand, handle form and roughly be divided into following 2 kinds: pulverize on the surface of pulverizing and cut particle surface at the inner volume that produces be full of cracks and make it to propagate of particle.Volume is pulverized and can be adopted impulsive force, compression stress, shearing force to carry out; The surface pulverizing can adopt the power of grinding, shearing force to carry out.Pulverizing is with the kind of the power that these materials are applied and handles the processing that form is carried out various combinations.Its combination can suitably be confirmed according to processing intent.
Though pulverize the reaction of using chemistry such as explosion or the situation that volumetric expansion is carried out arranged also, to use mechanical device such as pulverizer to carry out usually.The processing that the preferred final shared ratio of surface treatment of the pulverization process of using in the manufacturing as the spheroidization carbonaceous of raw material of the present invention uprises, and with to have or not volume to pulverize irrelevant.This is because remove the angle that particle surface pulverizes so that shape of particle becomes circle is important.Particularly, can after the volume pulverizing of carrying out to a certain degree, carry out surface treatment again, also can carry out the volume pulverizing hardly and only carry out surface treatment, can also carry out volume simultaneously and pulverize and surface treatment.Preferably carry out the surface at last and pulverize, remove the pulverization process at angle from the surface of particle.The negative electrode active material that uses among the present invention through containing the different negative electrode active material more than 2 kinds of above-mentioned surface-treated degree, can be kept cycle characteristics and improve the low temperature power output.
Carrying out the device of mechanics energy process selects from the device that can carry out above-mentioned preferred processing.The mechanics energy process can realize through using more than one the power in 4 kinds of power that above-mentioned substance is applied, but is main with impulsive force preferably, and particle applied the mechanisms such as compression, friction, shearing force of the interaction that comprises particle repeatedly.Therefore; Particularly; Preferred following device: this device has the rotor that is provided with a plurality of blades in case inside; And give the effect of machineries such as Shock Compression, friction, shearing force through the rotation of this rotor high-speed and to importing to inner material with carbon element, thereby the limit is carried out volume and is pulverized the limit and carry out surface treatment.In addition, more preferably have through making carbonaceous material circulation or convection current and give the device of the mechanism of mechanism repeatedly.
As preferred device, can enumerate hybrid system (nara machinery is made institute's manufactured), Kryptron (Earth Technica manufactured), CF mill (the emerging product manufactured of space portion), mechanical fusing system (hosokawamicron manufactured) etc.In the middle of these, preferred nara machinery is made the hybrid system of institute's manufactured.When using this device to handle, preferably the peripheral speed with rotor rotated is set at 30～100m/ second, more preferably is set at 40～100m/ second, further is preferably set to 50～100m/ second.In addition, processing can be that carbonaceous material is passed through, but preferably in device circulation or be detained 30 seconds with on handle, more preferably in device, circulate or be detained 1 minute with on handle.
Through carrying out the mechanics energy process like this, carbon particle becomes following particle: keep high crystalline on the whole, just the near surface of particle becomes coarse, tilts and exposes edge surface.Like this, the face that lithium ion can be come in and gone out increases, even under high current density, also have high capacity.
In general, the particle diameter of flakey, squamous, tabular material with carbon element is more little, and its fillibility has the tendency of deterioration more.This can think because following reason: since particle through pulverizing amorphization more; Perhaps " burr ", " peeling off " or the overshooting shape things such as " warpages " of particle surface generation increase; And be attached with finer reasons such as amorphous particle with to a certain degree intensity at particle surface; Like this, and big in abutting connection with the change of the impedance between the particle, fillibility is worsened.If the amorphism of these particles reduces, shape of particle approaches sphere, even then particle diameter diminishes, and the reducing also seldom of fillibility, in theory, big particle diameter carbon dust, small particle diameter carbon dust all should show the tap density of equal extent.
Ratio as the machining object of these native graphites and/or native graphite; Be generally 0.1 quality % above, be preferably 1 quality % above, more preferably 10 quality % above, further be preferably more than the 20 quality %, its upper limit is generally below the 99.9 quality %, is preferably below the 99 quality %, more preferably below the 90 quality %, further be preferably below the 80 quality %.If be lower than this scope, then be difficult to obtain the raising of the cost performance brought through the machining object that adds native graphite and/or native graphite sometimes.On the other hand, if surpass this scope, then be difficult to obtain the raising of the effect that different active material brings sometimes.
[[micropore volume etc.]]
The pore volume of the negative electrode active material that uses as the negative electrode active material of lithium secondary battery of the present invention; Through mercury porosimeter (mercury penetration method) try to achieve since be equivalent to the concavo-convex amount that causes of being uneven that diameter is space, particle surface in the particle of 0.01 μ m～1 μ m (below; Brief note is " micropore volume ") be generally more than the 0.01mL/g; Be preferably more than the 0.05mL/g, more preferably more than the 0.1mL/g, its upper limit is generally below the 0.6mL/g; Be preferably below the 0.4mL/g, more preferably the scope below the 0.3mL/g.If surpass this scope, need a large amount of adhesives when then manufacturing pole plate.If be lower than this scope, then the high current density charge-discharge characteristic reduces, and, the alleviation effects that the electrode in the time of can not obtaining discharging and recharging sometimes expands and shrinks.
In addition, total micropore volume is preferably more than the 0.1mL/g, and more preferably more than the 0.25mL/g, its upper limit is generally below the 10mL/g, is preferably below the 5mL/g, more preferably the scope below the 2mL/g.If surpass this scope, then when processing substrate, need a large amount of adhesives sometimes.If be lower than this scope, then when processing pole plate, can not obtain the dispersion effect of thickener or binding agent sometimes.
In addition, average micropore diameter is preferably more than the 0.05 μ m, more preferably more than the 0.1 μ m, further is preferably more than the 0.5 μ m, and its upper limit is generally below the 50 μ m, is preferably below the 20 μ m, more preferably the scope below the 10 μ m.If surpass this scope, then need a large amount of adhesives sometimes.If be lower than this scope, then the high current density charge-discharge characteristic reduces sometimes.
As the device that is used for the mercury porosimeter, can use mercury porosimeter (autopore9520; The micrometritics manufactured).Sample about weighing 0.2g (negative material) is encapsulated into powder with in the container, carries out the degassing in 10 minutes at (below the 50 μ mHg) under room temperature, the vacuum, implements pre-treatment.Then, be decompressed to 4psia (about 28kPa), import mercury, boost to 40000psia (about 280MPa), be depressurized to 25psia (about 170kPa) then from 4psia (about 28kPa) stage shape.Number of stages when boosting is more than 80 stages, in each stage, after 10 seconds equilibration time, measures the mercury amount of being pressed into.Use the Washburn formula to be pressed into opisometer and calculate the micropore distribution from the mercury that obtains like this.In addition, the surface tension of mercury (γ) is 485dyne/cm, and contact angle (φ) is 140 °.Average micropore diameter uses the accumulation micro pore volume to reach 50% o'clock micropore diameter.
[[ash content]]
The ash content of the negative electrode active material of lithium secondary battery of the present invention is preferably below the 1 quality %, more preferably below the 0.5 quality %, be preferably below the 0.1 quality % especially with respect to the gross mass of graphite matter carbon particle.In addition, its lower limit is preferably more than the 1ppm.If surpass above-mentioned scope, can not ignore with the reaction of nonaqueous electrolytic solution and the deterioration of the battery performance that causes when then discharging and recharging.On the other hand, if be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
[[orientation ratio]]
The orientation ratio of the graphite matter carbon particle that uses as the negative electrode active material of lithium secondary battery of the present invention is generally more than 0.005, is preferably more than 0.01, more preferably more than 0.015, be below 0.67 on the upper-bound theory.If be lower than this scope, then the high density charge-discharge characteristic reduces sometimes.
Orientation ratio is measured through X-ray diffraction.Use asymmetric Pearson VII as distribution function, (110) diffraction of the carbon that match obtains through X-ray diffraction and the peak of (004) diffraction carry out the peak and separate, and calculate the integrated intensity at the peak of (110) diffraction and (004) diffraction respectively.Calculate by the ratio that (110) diffraction integral intensity/(004) diffraction integral intensity is represented by the integrated intensity that obtains, this ratio is defined as the active material orientation ratio.
The X-ray diffraction condition determination here is following.In addition, " 2 θ " expression angle of diffraction.
The monochromatic photometer of target: Cu (K alpha ray) graphite
Slit: divergent slit=1 degree receives optical slits=0.1mm, scatter slit=1 degree
Measurement range and step angle/minute
(110) face: 76.5 degree≤2 θ≤78.5 degree 0.01 are spent/3 seconds
(004) face: 53.5 degree≤2 θ≤56.0 degree 0.01 are spent/3 seconds
[[draw ratio]]
The draw ratio of the graphite matter carbon particle that uses as the negative electrode active material of lithium secondary battery of the present invention is more than 1 in theory, on be limited to below 10, be preferably below 8, more preferably below 5.If surpass its upper limit, wire drawing maybe can't obtain uniform coated face when processing pole plate, and the high current density charge-discharge characteristic reduces sometimes.
The ratio A/B of the major diameter A of particle and perpendicular minor axis B represented when in addition, draw ratio was with three dimensional viewing.The observation of particle is carried out through the scanning electron microscope that can amplify observation.Selection is fixed on any 50 graphite particles on the end face of the metal of thickness below 50 microns, rotation, tilts to be fixed with the objective table of sample, measures A, the B of these particles respectively, obtains the mean value of A/B.
Of the present invention have negative pole [8] if lithium secondary battery contain the negative electrode active material more than 2 kinds of different in kind, the kind of negative electrode active material is not special to be limited.But, for the character through X-ray diffraction mensuration such as interplanar distance (d002), crystallite size (Lc), orientation ratio, pole plate orientation ratio; The character relevant such as Raman R value, Raman half breadth with Raman spectrum; And ash content, because above-mentioned numerical value is prerequisite with the carbonaceous material, therefore the difference of above-mentioned numerical value is applicable to carbonaceous material.On the other hand, for character relevant such as median particle diameter, mould footpath, Z with particle size distribution; The BET specific area; Micropore volume, total micropore volume, average micropore diameter etc. are through the fixed character of mercury voidage instrumentation; Real density; Circularity; Tap density; And draw ratio, above-mentioned numerical value is not limited to carbonaceous material, is applicable to that all can be as the material of negative electrode active material, and the difference of above-mentioned numerical value also is applicable to all materials.But the material that preferably has above-mentioned 2 kinds of character is a carbonaceous material.At this moment, above-mentioned numerical value is regarded the value of the character of representing carbonaceous material as, and the carbonaceous material more than 2 kinds of preferably using this different in kind is as negative electrode active material.
[mixed method of negative electrode active material more than 2 kinds of negative pole [8]]
When mixing more than 2 kinds negative electrode active material, the device of use is not special to be limited, and for example can enumerate V-Mixer, Wtypeofblender, container changeable type mixer, mixing roll, barrel mixer, shear mixer etc.
[the electrode manufacturing of negative pole [8]]
The manufacturing of negative pole [8] can be carried out through conventional method, can with the above-mentioned negative pole [8] that likewise forms.The thickness ratio of collector body, collector body and active material layer, electrode density, adhesive, pole plate orientation ratio, impedance etc. are also same as described above.
< negative pole [9] and [10] >
In the face of negative pole [9] (mode A) and the negative pole [10] (mode B) that uses in the lithium secondary battery of the present invention describes, it is 0.1g/cm that said negative pole [9] contains tap density down 3More than, and the micropore volume of the particle that is equivalent to diameter 0.01 μ m～1 mu m range of employing mercury porosimeter mensuration is the above negative electrode active material of 0.01mL/g; Said negative pole [10] is charged to 60% o'clock of nominal capacity of this negative pole, and the reaction resistance that is produced by the opposed battery of negative pole is below 500 Ω.
＜＜negative pole [9] (mode A)＞＞
Mode A of the present invention relates to a kind of lithium secondary battery; Wherein, Negative pole to using among the present invention is stipulated with the rerum natura of the negative electrode active material that wherein contains; And this lithium secondary battery comprises nonaqueous electrolytic solution and negative pole, and said nonaqueous electrolytic solution contains above-mentioned specific compound, and said negative pole contains the negative electrode active material with following specific rerum natura.Describe in the face of mode A of the present invention down.
[negative electrode active material of negative pole [9]]
Negative electrode active material among the mode A of the present invention can occlusion on electrochemistry, emit lithium ion, and (a) and important document (b) below satisfying at least.
(a) tap density is 0.1g/cm 3More than;
(b) micropore volume of the scope of the 0.01 μ m～1 μ m of employing mercury porosimeter mensuration is more than the 0.01mL/g.
[[tap density]]
The tap density of the negative electrode active material that contains in the negative pole of lithium second electrode of the present invention [9] is preferably 0.1g/cm 3More than, 0.5g/cm more preferably 3More than, further be preferably 0.7g/cm 3More than, be preferably 0.9g/cm especially 3More than.In addition, its upper limit is preferably 2g/cm 3Below, 1.8g/cm more preferably 3Below, be preferably 1.6g/cm especially 3Below.If tap density is lower than this scope, then particularly can not realize the effect of high-output power.On the other hand, if surpass this scope, then the interparticle space in the electrode is very few, and the stream in the nonaqueous electrolytic solution reduces, and power output itself reduces sometimes.
In the present invention, tap density is as giving a definition: make sample pass through the sieve of aperture 300 μ m, make sample fall into 20cm 3The jolt ramming container in, be full of the upper surface of container to sample after, (for example use the powder density determination device; The Tap densor that seishin enterprise-like corporation makes); Carry out the vibration of 1000 length of stroke 10mm, the volume and weight bulk density in the time of thus should be worth as tap density.
[[micropore volume]]
The micropore volume of the negative electrode active material that contains in the negative pole of lithium secondary battery of the present invention [9]; Through mercury porosimeter (mercury penetration method) try to achieve since be equivalent to the concavo-convex amount that causes of being uneven that diameter is space, particle surface in the particle of 0.01 μ m～1 μ m (below; Brief note is " micropore volume ") be more than the 0.01mL/g; Be preferably more than the 0.05mL/g, more preferably more than the 0.1mL/g, its upper limit is generally below the 0.6mL/g; Be preferably below the 0.4mL/g, more preferably the scope below the 0.3mL/g.If surpass this scope, need a large amount of adhesives when then manufacturing pole plate.On the other hand, if be lower than this scope, then can not realize long-life, high-output power.
In addition, total micropore volume is preferably more than the 0.1mL/g, more preferably more than the 0.25mL/g, further is preferably more than the 0.4mL/g, and its upper limit is generally below the 10mL/g, is preferably below the 5mL/g, more preferably the scope below the 2mL/g.If surpass this scope, then when processing substrate, need a large amount of adhesives sometimes.If be lower than this scope, then when processing pole plate, can not obtain the dispersion effect of thickener or binding agent sometimes.Here said " total micropore volume " is meant the micropore volume sum of in the four corner of following condition determination, measuring.
In addition, average micropore diameter is preferably more than the 0.05 μ m, more preferably more than the 0.1 μ m, further is preferably more than the 0.5 μ m, and its upper limit is generally below the 50 μ m, is preferably below the 20 μ m, more preferably the scope below the 10 μ m.If surpass this scope, then need a large amount of adhesives sometimes.If be lower than this scope, then the high current density charge-discharge characteristic reduces sometimes.
As the device that is used for the mercury porosimeter, can use mercury porosimeter (autopore9520; The micrometritics manufactured).Sample about weighing 0.2g (negative material) is encapsulated into powder with in the container, carries out the degassing in 10 minutes at (below the 50 μ mHg) under room temperature, the vacuum, implements pre-treatment.Then, be decompressed to 4psia (about 28kPa), import mercury, boost to 40000psia (about 280MPa), be depressurized to 25psia (about 170kPa) then from 4psia (about 28kPa) stage shape.Number of stages when boosting is more than 80 stages, in each stage, after 10 seconds equilibration time, measures the mercury amount of being pressed into.Use the Washburn formula to be pressed into opisometer and calculate the micropore distribution from the mercury that obtains like this.In addition, the surface tension of mercury (γ) is 485dyne/cm, and contact angle (φ) is 140 °.Average micropore diameter uses the accumulation micro pore volume to reach 50% o'clock micropore diameter.
The lithium secondary battery of mode A of the present invention is for negative electrode active material, as long as satisfy above-mentioned important document (a) and (b) just can bring into play the effect of the invention described above; Give full play to performance; Further, for negative electrode active material, preferably satisfy following rerum natura simultaneously any one or multinomial.In addition, for negative pole, in the rerum natura of the negative pole among the preferred especially mode B that states after satisfying simultaneously or the structure any one or multinomial.
[[BET specific area]]
The specific area of the negative electrode active material that contains in the negative pole [9] of the lithium secondary battery of the present invention that use BET method is measured is preferably 0.1m 2More than/the g, be preferably 0.7m especially 2More than/the g, 1m more preferably 2More than/the g, further be preferably 1.5m 2More than/the g.Its upper limit is preferably 100m 2Below/the g, be preferably 50m especially 2Below/the g, 25m more preferably 2Below/the g, further be preferably 15m 2Below/the g.If the value of BET specific area is lower than above-mentioned scope, then under situation about using as negative material, the acceptance variation of lithium when charging, lithium is separated out at electrode surface easily, can not obtain high-output power sometimes.On the other hand, if surpass above-mentioned scope, then when using as negative material, with the reactivity increase of electrolyte, it is many that the gas of generation becomes, and is difficult to obtain preferred battery sometimes.
The BET specific area is defined as the value of following mensuration: (for example use the surface area meter; The full automatic watch area estimation device that the reason development of big storehouse is made); Under nitrogen circulation, 350 ℃ to sample carry out 15 minutes predrying; Then, use nitrogen accurately to be adjusted into 0.3 nitrogen helium gas mixture body, measure through the nitrogen absorption BET1 point method that adopts the gas flow method with respect to atmospheric relative pressure value.
[[volume average particle size]]
The volume average particle size of the negative electrode active material that contains in the negative pole of lithium secondary battery of the present invention [9] is defined as the average grain diameter (median particle diameter) of the volume reference of trying to achieve through laser diffraction/scattering method; Be preferably more than the 1 μ m; Be preferably especially more than the 3 μ m; More preferably more than the 5 μ m, further be preferably more than the 7 μ m.In addition, its upper limit is generally below the 50 μ m, is preferably below the 40 μ m, more preferably below the 30 μ m, further is preferably below the 25 μ m.If be lower than above-mentioned scope, then irreversible capacity increases, and causes the loss of initial stage battery capacity sometimes.In addition, if surpass above-mentioned scope, then when processing electrode pad, forming uneven coated face easily, is not preferred sometimes on the battery production process.
In the present invention; The volume reference average grain diameter defines with median particle diameter; Said median particle diameter is measured through following method: carbon dust is dispersed in the 0.2 quality % aqueous solution (about 1mL) of polyoxyethylene (20) Span-20 as surfactant; Use laser diffraction/diffuse transmission type particle size distribution meter (for example, the hole field makes the LA-700 of institute's manufactured) to measure.
[[circularity]]
The circularity of the negative electrode active material that contains in the negative pole of lithium second electrode of the present invention [9] is generally more than 0.1, is preferably more than 0.5, more preferably more than 0.8, is preferably especially more than 0.85, further is preferably more than 0.9.As the upper limit, circularity is to form proper sphere at 1 o'clock in theory.If circularity is lower than this scope, then might produce problems such as wire drawing during electric polarization.
Said circularity defines with following formula among the present invention.
Circularity=(having girth)/(perimeter of particle projection of shape) with particle projection of shape equivalent circular of the same area
Use the following value of measuring as the value of circularity: (for example use flow-type particle picture analytical equipment; The FPIA of Sysmex Industrial manufactured); About 0.2g sample is scattered in the 0.2 quality % aqueous solution (about 50mL) of polyoxyethylene (20) Span-20 as surfactant; Behind the ultrasonic wave with 1 minute 28kHz of the power output of 60W irradiation, specifying 0.6～400 μ m is detection range, and the particle of particle diameter 3～40 mu m ranges is measured.
[[interplanar distance (d002)]]
The negative electrode active material that contains in the negative pole of lithium secondary battery of the present invention [9] adopts the interplanar distance (d002) of (002) face of wide-angle x-ray diffraction mensuration to be generally below the 0.38nm; Be preferably below the 0.36nm; More preferably below the 0.35nm; Further be preferably below the 0.345nm, it is limited to more than the theoretical value 0.335nm of graphite down.If surpass this scope, then crystallinity significantly reduces, and irreversible capacity increases sometimes.
The interplanar distance (d002) of said (002) face of measuring through wide-angle x-ray diffraction among the present invention is meant the d value (interfloor distance) of lattice plane (002) face of trying to achieve with X-ray diffraction through the method for shaking.
[[crystallite size (Lc)]]
In addition, not special qualification of crystallite size (Lc) of the negative electrode active material of trying to achieve with X-ray diffraction through the method for shaking is generally more than the 0.1nm, is preferably more than the 0.5nm, more preferably the above scope of 1nm.If be lower than this scope, then crystallinity significantly reduces, and irreversible capacity increases sometimes.
[[real density]]
The real density of the negative electrode active material that contains in the negative pole of lithium secondary battery of the present invention [9] is generally 1.5g/cm 3More than, be preferably 1.7g/cm 3More than, 1.8g/cm more preferably 3More than, further be preferably 1.85g/cm 3More than, be limited to 2.26g/cm on it 3Below.On be limited to the theoretical value of graphite.If be lower than this scope, then the crystallinity of carbon is low excessively, and irreversible capacity increases sometimes.In the present invention, real density is defined as the value of measuring through the liquid phase displacement method (hydrometer method) of using butanols.
[[Raman R value]]
The Raman R value of the negative electrode active material that contains in the negative pole of lithium secondary battery of the present invention [9] is generally more than 0.01, is preferably more than 0.03, more preferably more than 0.1.As the upper limit, be preferably below 1.5, more preferably below 1.2, be preferably below 0.5 especially.If Raman R value is lower than this scope, then the crystallinity of particle surface is too high, and along with the minimizing that discharges and recharges the site, power output reduces sometimes.On the other hand, if surpass this scope, then the crystallinity of particle surface reduces, and irreversible capacity increases sometimes.
The mensuration of Raman spectrum is carried out as follows: use raman spectroscopy device (the raman spectroscopy device that for example Japanese beam split society makes); Sample is fallen naturally and be filled in the cell; To the specimen surface in pond irradiation argon laser, simultaneously, make the pond with the face of laser vertical in rotate.For the Raman spectrum that obtains, measure 1580cm -1Peak P AIntensity I AAnd 1360cm -1Peak P BIntensity I B, calculate its strength ratio R (R=I B/ I A), it is defined as the Raman R value of negative electrode active material.In addition, measure the Raman spectrum obtain at 1580cm -1Near peak P AHalf breadth, it is defined as the Raman half breadth of negative electrode active material.
In addition, the Raman condition determination here is following.
Argon laser wavelength: 514.5nm
Laser power on the sample: 15～25mW
Resolution: 10～20cm -1
Measurement range: 1100cm -1～1730cm -1
Raman R value, Raman half breadth are analyzed: background is handled
Smooth treatment: simple average, convolution 5 points
In addition, the negative electrode active material that contains in the negative pole of lithium secondary battery of the present invention [9] is at 1580cm -1The Raman half breadth have no particular limits, be generally 10cm -1More than, be preferably 15cm -1More than, in addition, its upper limit is generally 150cm -1Below, be preferably 100cm -1Below, 60cm more preferably -1Following scope.If the Raman half breadth is lower than this scope, then the crystallinity of particle surface is too high, and along with the minimizing that discharges and recharges the site, power output reduces sometimes.On the other hand, if be higher than this scope, then the crystallinity of particle surface reduces, and irreversible capacity increases sometimes.
[[ash content]]
The ash content of the negative electrode active material that contains in the negative pole of lithium secondary battery of the present invention [9] is preferably below the 1 quality %, more preferably below the 0.5 quality %, be preferably below the 0.1 quality % especially.In addition, as lower limit, be preferably more than the 1ppm.If surpass above-mentioned scope, can not ignore with the reaction of nonaqueous electrolytic solution and the deterioration of the battery performance that causes when then discharging and recharging, the circulation conservation rate reduces sometimes.On the other hand, if be lower than this scope, then on making, need long period and energy and be used for antipollution equipment, cost can rise sometimes.
[[draw ratio]]
The negative electrode active material that contains in the negative pole of lithium secondary battery of the present invention [9] draw ratio be more than 1 in theory, as the upper limit, be generally below 10, be preferably below 8, more preferably below 5.If surpass its upper limit, the active material wire drawing maybe can't obtain uniform coated face when then making negative pole, and the high current density charge-discharge characteristic reduces sometimes.
The ratio A/B of the major diameter A of particle and perpendicular minor axis B represented when in addition, draw ratio was with three dimensional viewing.The observation of particle is carried out through the scanning electron microscope that can amplify observation.Selection is fixed on any 50 graphite particles on the end face of the metal of thickness below 50 microns, rotation, tilts to be fixed with the objective table of sample, measures A, the B of these particles respectively, obtains the mean value of A/B.
[[orientation ratio]]
The orientation ratio of the negative electrode active material that contains in the negative pole of lithium secondary battery of the present invention [9] is generally more than 0.005, is preferably more than 0.01, and more than 0.015, be below 0.67 on the upper-bound theory more preferably.If be lower than this scope, then the high density charge-discharge characteristic reduces sometimes.
Orientation ratio is measured through X-ray diffraction.Use asymmetric Pearson VII as distribution function, (110) diffraction of the carbon that match obtains through X-ray diffraction and the peak of (004) diffraction carry out the peak and separate, and calculate the integrated intensity at the peak of (110) diffraction and (004) diffraction respectively.Calculate by the ratio that (110) diffraction integral intensity/(004) diffraction integral intensity is represented by the integrated intensity that obtains, this ratio is defined as the negative electrode active material orientation ratio.
The X-ray diffraction condition determination here is following.In addition, " 2 θ " expression angle of diffraction.
The monochromatic photometer of target: Cu (K alpha ray) graphite
Slit: divergent slit=1 degree receives optical slits=0.1mm, scatter slit=1 degree
Measurement range and step angle/minute
(110) face: 76.5 degree≤2 θ≤78.5 degree 0.01 are spent/3 seconds
(004) face: 53.5 degree≤2 θ≤56.0 degree 0.01 are spent/3 seconds
[making the electrode of negative pole [9]]
The manufacturing of negative pole can be carried out through conventional method, can with the above-mentioned negative pole [9] that likewise forms.The thickness ratio of collector body, collector body and active material layer, electrode density, adhesive, pole plate orientation ratio, impedance etc. are also same as described above.
＜＜for negative pole [10] (mode B)＞＞
Negative pole of the present invention [10] (mode B) relates to a kind of lithium secondary battery; Wherein, Negative pole to using among the present invention is stipulated with the rerum natura and/or the structure of negative pole itself; This lithium secondary battery comprises nonaqueous electrolytic solution and has the following specific rerum natura and/or the negative pole of structure that said nonaqueous electrolytic solution contains above-mentioned specific compound.Describe in the face of negative pole of the present invention [10] (mode B) down.
[rerum natura, the structure of negative pole [10] negative pole]
Below the rerum natura and the structure of the negative pole that uses in the lithium secondary battery to mode B describe.Negative pole has negative electrode active material layer on collector body.
[[reaction resistance]]
The reaction resistance that the opposed impedance of the negative pole that uses among the mode B of the present invention (subtend イ Application ピ one ダ Application ス) is tried to achieve in measuring is necessary for below 500 Ω, is preferably below 100 Ω, more preferably below 50 Ω.Lower limit is not special to be limited.If surpass this scope, when then processing lithium secondary battery, reduce with afterwards characteristics of output power before the cyclic test.In addition, produce the reduction of circulation conservation rate sometimes owing to high resistance.
The assay method of opposed impedance is described below.General in the impedance measuring of lithium secondary battery; Measure implementing AC impedance between the positive terminal of battery and the negative terminal; But if the impedance that then finally expression is anodal and negative pole mixes of this method of use can not confirm clearly which which positive and negative electrode resistance produced by.Therefore, in the present invention, only measure the reaction resistance that the opposed battery by negative pole produces.Narrate the assay method of the reaction resistance among the present invention below.
The lithium secondary battery of measuring uses following battery: after can charging with the current value of 5 hours charging nominal capacitys; Keep the state that did not did not discharge and recharge in 20 minutes; Discharging with the current value of 1 hour discharge nominal capacity, the capacity of this moment is more than 80% of nominal capacity then.For the lithium secondary battery of above-mentioned discharge condition,, immediately lithium secondary battery is transferred in the gloves work box under the argon atmosphere charging to 60% of nominal capacity with the current value of 5 hours charging nominal capacitys.Wherein, With this lithium secondary battery negative pole do not discharge or the state of not short circuit under apace dismounting take out; If two sided coatings electrode; Then do not damage another side electrode active material ground electrode active material is simultaneously peeled off, 2 negative electrode punchings are become 12.5mm φ, it is opposed to make the active material face not depart from ground through dividing plate.To between dividing plate and two negative poles, drip the nonaqueous electrolytic solution 60 μ L that use in the battery and also seal, keep not and extraneous state of contact, on the collector body of two negative poles, conduct electricity, implement AC impedence method.Mensuration is under 25 ℃ of the temperature, carry out complex impedance measuring under the frequency band of 10-2～105Hz; The circular arc of the negative pole resistance components of the Ke Li that tries to achieve-Ke Li curve (コ one Le コ one Le プ ロ Star ト) is approximately semicircle, tries to achieve reaction resistance (Rct) and double-deck capacity (Cdl).
In the lithium secondary battery of mode B of the present invention; For negative pole; As long as the reaction resistance that is produced by the opposed battery (subtend セ Le) of negative pole satisfies above-mentioned important document, just can bring into play the effect of the invention described above, thus the performance of giving full play to; Further, preferably satisfy rerum natura or structure any one or multinomial of following negative pole simultaneously.In addition, for negative electrode active material, especially preferably satisfy any or multinomial of rerum natura of the negative electrode active material described in the mode A item simultaneously.
[[double-deck capacity (Cdl)]]
The double-deck capacity (Cdl) of trying to achieve in the opposed impedance measuring of the negative pole that uses among the present invention is preferably 1 * 10 -6F is above, be preferably 1 * 10 especially -5F is above, more preferably 3 * 10 -5More than the F.If be lower than this scope, then because the area that can react reduces, power output reduces sometimes as a result.
[[adhesive]]
As with negative electrode active material and the bonding adhesive of collector body; So long as the material of the solvent-stable that uses when making for nonaqueous electrolytic solution or electrode gets final product; Not special restriction, operable material, adhesive are same as described above with respect to the ratio of whole negative electrode active material layers etc.
[negative pole [10] electrode manufacturing]
The manufacturing of negative pole [10] can be carried out through conventional method, can with the above-mentioned negative pole [10] that likewise forms.The thickness ratio of collector body, collector body and active material layer, electrode density, adhesive, pole plate orientation ratio, impedance etc. are also same as described above.
< nonaqueous electrolytic solution >
As long as the nonaqueous electrolytic solution that uses among the present invention contains electrolyte (lithium salts) and dissolves this electrolytical nonaqueous solvents, specific compound; Not special the qualification, this nonaqueous electrolytic solution preferably satisfies the electrolyte of the arbitrary condition in following electrolyte [1]～electrolyte [9] that is selected from:
Electrolyte [1]: the nonaqueous solvents that constitutes electrolyte is the mixed solvent that contains ethylene carbonate at least, and ethylene carbonate is 1 volume %～25 volume % with respect to the ratio of nonaqueous solvents total amount;
Electrolyte [2]: the nonaqueous solvents that constitutes electrolyte contains at least a asymmetric linear carbonate, and this asymmetric linear carbonate is shared in whole nonaqueous solventss, and to contain proportional be 5 volume %～90 volume %;
Electrolyte [3]: the nonaqueous solvents that constitutes electrolyte contains at least a chain carboxylate;
Electrolyte [4]: it is the solvent more than 70 ℃ that the nonaqueous solvents of formation electrolyte contains flash-point, and its content is more than the 60 volume % of whole nonaqueous solventss;
Electrolyte [5]: contain LiN (C nF 2n+1SO 2) 2(in the formula, n is 1～4 integer) and/or two (oxalate closes) lithium borate are as the lithium salts that constitutes electrolyte;
Electrolyte [6]: the lithium salts that constitutes electrolyte is fluorine-containing lithium salts, and in whole nonaqueous electrolytic solutions, contains the hydrogen fluoride (HF) of 10ppm～300ppm;
Electrolyte [7]: in electrolyte, contain vinylene carbonate, the content of this vinylene carbonate is the scope of the 0.001 quality %～3 quality % of electrolyte gross mass;
Electrolyte [8]: in electrolyte, also contain at least a compound in the compound that is selected from above-mentioned general formula (4) expression, the heterocyclic compound that contains nitrogen and/or sulphur, cyclic carboxylic esters, the fluorine-containing cyclic carbonate, its content in whole nonaqueous electrolytic solutions is the scope of 0.001 quality %～5 quality %;
Electrolyte [9]: in electrolyte, also containing overcharges prevents agent.
Below, at first normally used nonaqueous electrolytic solution in the lithium secondary battery of the present invention is described.
[lithium salts]
As electrolyte, do not limit so long as the lithium salts that the known electrolyte that can be used as the secondary lithium batteries nonaqueous electrolytic solution uses is then special, for example can enumerate following lithium salts.
Inorganic lithium salt: LiPF 6, LiBF 4, LiAsF 6, LiSbF 6Etc. inorganic fluoride salts; LiClO 4, LiBrO 4, LiIO 4Deng perhalide; LiAlCl 4Deng butter salt etc.
Fluorine-containing organic lithium salt: LiCF 3SO 3Etc. perfluoroalkanesulfosalt salt; LiN (CF 3SO 2) 2, LiN (CF 3CF 2SO 2) 2, LiN (CF 3SO 2) (C 4F 9SO 2) wait perfluoroalkane sulfimide salt; LiC (CF 3SO 2) 3Deng perfluoroalkane sulfonymethyl salt, Li [PF 5(CF 2CF 2CF 3)], Li [PF 4(CF 2CF 2CF 3) 2], Li [PF 3(CF 2CF 2CF 3) 3], Li [PF 5(CF 2CF 2CF 2CF 3)], Li [PF 4(CF 2CF 2CF 2CF 3) 2], Li [PF 3(CF 2CF 2CF 2CF 3) 3] wait fluoroalkyl fluorinated phosphate salt etc.
Oxalate closes borate: two (oxalate closes) lithium borate, difluoro oxalate root close lithium borate etc.
They can use a kind of separately, also can use more than 2 kinds with combination and ratio combination arbitrarily.Wherein, if comprehensively judge dissolubility in nonaqueous solvents, the charge-discharge characteristic when processing secondary cell, characteristics of output power, cycle characteristics etc., then be preferably LiPF 6
Preferred example when combination is used more than 2 kinds uses LiPF for combination 6With LiBF 4, at this moment, LiBF 4Account for both ratios of total and be preferably 0.01 quality %～20 quality %, be preferably 0.1 quality %～5 quality % especially.
In addition, the another one example uses inorganic fluoride salts and perfluoroalkane sulfimide salt for combination, and at this moment, inorganic fluoride salts accounts for both ratios of total and is preferably 70 quality %～99 quality %, more preferably 80 quality %～98 quality %.This both combination is used to have and is suppressed the effect that Yin Gaowen preserves the deterioration that causes.
The not special restriction of the concentration of the above-mentioned lithium salts in the nonaqueous electrolytic solution, but be generally more than the 0.5mol/L, be preferably more than the 0.6mol/L, more preferably more than the 0.7mol/L.In addition, its upper limit is generally below the 2mol/L, is preferably below the 1.8mol/L, more preferably below the 1.7mol/L.If concentration is low excessively, then the conductivity of nonaqueous electrolytic solution is insufficient sometimes, and on the other hand, if excessive concentration, then because viscosity raises, and conductivity reduces sometimes, the performance of lithium secondary battery reduces sometimes.
[nonaqueous solvents]
As nonaqueous solvents, can from the solvent that proposes as the solvent of nonaqueous electrolytic solution in the past, suitably select to use.For example can enumerate following nonaqueous solvents.
1) cyclic carbonate:
The carbon number that constitutes the alkylidene of cyclic carbonate is preferably 2～6, is preferably 2～4 especially.Specifically, for example can enumerate ethylene carbonate, propylene carbonate, butylene carbonate etc.Wherein, be preferably ethylene carbonate, propylene carbonate.
2) linear carbonate
As linear carbonate, be preferably dialkyl carbonate, the carbon number that constitutes the alkyl of dialkyl carbonate is preferably 1～5 respectively, is preferably 1～4 especially.Specifically, for example can enumerate dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, carbonic acid di-n-propyl ester, methyl ethyl carbonate, carbonic acid methyl n-pro-pyl ester, carbonic acid ethyl n-pro-pyl ester.Wherein, be preferably dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate.
3) cyclic ester:
Specifically, for example can enumerate gamma-butyrolacton, gamma-valerolactone etc.
4) chain ester:
Specifically, for example can enumerate methyl acetate, ethyl acetate, propyl acetate, methyl propionate etc.
5) cyclic ether
Specifically, for example can enumerate oxolane, 2-methyltetrahydrofuran, oxinane etc.
6) chain ether:
Specifically, for example can enumerate dimethoxy-ethane, dimethoxymethane etc.
7) sulfur-bearing organic solvent:
Specifically, for example can enumerate sulfolane, diethyl sulfone etc.
They can use separately, also can make up and use more than 2 kinds, and preferred compositions is used the compound more than 2 kinds.For example, the solvent and the low viscosity solvent combinations such as linear carbonate class or chain ester class of high-ks such as preferred cyclic carbonates or cyclic ester class are used.
One of preferred compositions of nonaqueous solvents is the combination that is the main body with cyclic carbonates and linear carbonate class.Wherein, the total of cyclic carbonates and linear carbonate class accounts in nonaqueous solvents more than the 80 capacity %, more than the preferred 85 capacity %, more preferably more than the 90 capacity %.In addition, with respect to the total of cyclic carbonates and linear carbonate class, the capacity of cyclic carbonates is more than 5%, is preferably more than 10%, more preferably more than 15%, and is generally below 50%, is preferably below 35%, more preferably below 30%.Especially preferably with the total of carbonates in nonaqueous solvents shared above-mentioned preferred range of capacity, with the preferred above-mentioned range of capacity combination of cyclic carbonates with respect to ring-type and linear carbonate class.If use the combination of this nonaqueous solvents, then owing to the balance of the cycle characteristics of the battery that uses this combination to make and high temperature preservation characteristics (residual capacity and high load capacity discharge capacity after the particularly high temperature is preserved) excellence that becomes, so preferably.
In this mixed solvent, contain the nonaqueous electrolytic solution that is selected from least a compound in compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that has the S-F key in the compound shown in the fluorosilane compounds shown in the cyclic siloxane compound shown in lithium salts and the above-mentioned general formula (1), the above-mentioned general formula (2), the above-mentioned general formula (3), the molecule; So the excellence because the balance that the cycle characteristics of the battery that this nonaqueous electrolytic solution of use is made and high temperature preservation characteristics (residual capacity and high load capacity discharge capacity after particularly high temperature is preserved) and inhibition gas produce becomes is preferred.
Object lesson as the preferred compositions of cyclic carbonates and linear carbonate class; Can enumerate ethylene carbonate and dimethyl carbonate, ethylene carbonate and diethyl carbonate, ethylene carbonate and methyl ethyl carbonate; Ethylene carbonate, dimethyl carbonate and diethyl carbonate; Ethylene carbonate, dimethyl carbonate and methyl ethyl carbonate, ethylene carbonate, diethyl carbonate and methyl ethyl carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate etc.Can enumerate the combination that in the combination of these ethylene carbonates and linear carbonate, has further added propylene carbonate makes up as preferred.When containing propylene carbonate, the Capacity Ratio of ethylene carbonate and propylene carbonate is generally 99: 1～and 40: 60, be preferably 95: 5～50: 50.
Further; If the amount that makes propylene carbonate account for whole nonaqueous solventss is more than the 0.1 capacity %, is preferably more than the 1 capacity %, more preferably more than the 2 capacity %; And be generally below the 10 capacity %, be preferably below the 8 capacity %, more preferably below the 5 capacity %; Then because can be on the basis of the characteristic of the combination of keeping ethylene carbonate and linear carbonate class, low-temperature characteristics be more excellent, so preferably.
Wherein, Further preferably contain asymmetric linear carbonate class; Particularly contain ethylene carbonate, dimethyl carbonate and methyl ethyl carbonate, ethylene carbonate, diethyl carbonate and methyl ethyl carbonate, ethylene carbonate, symmetrical linear carbonate class and asymmetric linear carbonate time-likes such as ethylene carbonate, dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate; Because the balance of cycle characteristics and heavy-current discharge characteristic is excellent, so preferred.Wherein, preferred asymmetric linear carbonate class is a methyl ethyl carbonate, and in addition, the carbon number that constitutes the alkyl of dialkyl carbonate is preferably 1～2.
Other example of preferred nonaqueous solvents is the nonaqueous solvents that contains the chain ester.As the chain ester, be preferably methyl acetate, ethyl acetate etc. especially.Chain ester shared capacity in nonaqueous solvents is generally more than 5%, is preferably more than 8%, more preferably more than 15%, and be generally below 50%, be preferably below 35%, more preferably below 30%, further be preferably below 25%.Particularly, consider, preferably in the mixed solvent of above-mentioned cyclic carbonates and linear carbonate class, contain the chain ester from the low-temperature characteristics aspect that improves battery.
The example of other preferred nonaqueous solvents; For being selected from a kind of organic solvent in ethylene carbonate, propylene carbonate, gamma-butyrolacton and the gamma-valerolactone, or contain the above nonaqueous solvents of 60 capacity % that the mixed solvent of organic solvent more than 2 kinds that is selected from this group accounts for whole solvents.The preferred flash-point of such mixed solvent is more than 50 ℃, and wherein, preferred especially flash-point is more than 70 ℃.Even use the nonaqueous electrolytic solution of this solvent at high temperature to use, the evaporation or the leakage of solvent also reduce.Wherein, If using gamma-butyrolacton shared amount in nonaqueous solvents is the solvent more than the 60 capacity %; The total of ethylene carbonate and gamma-butyrolacton accounts for more than the 80 capacity % in nonaqueous solvents, be preferably more than the 90 capacity % and the Capacity Ratio of ethylene carbonate and gamma-butyrolacton is 5: 95～45: 55 a solvent; Or the total of ethylene carbonate and propylene carbonate accounts for more than the 80 capacity % in nonaqueous solvents, is preferably more than the 90 capacity % and the Capacity Ratio of ethylene carbonate and propylene carbonate is 30: 70～60: 40 a solvent, the balance of then general cycle characteristics and heavy-current discharge characteristic etc. the excellence that becomes.
[specific compound]
Nonaqueous electrolytic solution of the present invention; As stated; It is characterized in that, contain or add at least a compound (sometimes they being abbreviated as " specific compound ") that is selected from compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that has the S-F key in the compound shown in the fluorosilane compounds shown in the cyclic siloxane compound shown in the general formula (1), the general formula (2), the general formula (3), the molecule.
[[cyclic siloxane compound shown in the general formula (1)]]
R in the cyclic siloxane compound shown in the general formula (1) 1And R 2For the organic group of the carbon number 1～12 that can be same to each other or different to each other, as R 1And R 2, can enumerate chain-like alkyls such as methyl, ethyl, n-pro-pyl, isopropyl, butyl, isobutyl group, sec-butyl, the tert-butyl group; Cyclic alkyls such as cyclohexyl, norborneol alkyl; Alkenyls such as vinyl, 1-acrylic, pi-allyl, cyclobutenyl, 1,3-butadiene base; Alkynyls such as acetenyl, propinyl, butynyl; Haloalkyls such as trifluoromethyl; 3-pyrrolidines and propyl group etc. have the alkyl of saturated heterocyclyl; The aryl such as phenyl that can have alkyl substituent; Aralkyl such as phenyl methyl, phenylethyl; Trialkylsilkls such as trimethyl silyl; Trialkyl silica oxyalkyls such as trimethylsiloxane group etc.
Wherein, the group that carbon number is few is prone to show characteristic, is preferably the organic group of carbon number 1～6.In addition, alkenyl improves characteristics of output power owing to acting on filming of nonaqueous electrolytic solution or electrode surface, and aryl has the effect that improves cell integrated performance owing to catching the free radical that in battery, produces when discharging and recharging, so preferred.Therefore, as R 1And R 2, be preferably methyl, vinyl or phenyl especially.
In the general formula (1), n representes 3～10 integer, is preferably 3～6 integer, is preferably 3 or 4 especially.
As the example of the cyclic siloxane compound shown in the general formula (1), for example can enumerate hexamethyl cyclotrisiloxane, Hexaethyl cyclotrisiloxane, hexaphenyl cyclotrisiloxane, 1,3,5-trimethyl-1,3, cyclotrisiloxane such as 5-trivinyl cyclotrisiloxane; Cyclotetrasiloxanes such as octamethylcy-clotetrasiloxane; D5s such as decamethylcyclopentaandoxane etc.Wherein, preferred especially cyclotrisiloxane.
[[fluorosilane compounds shown in the general formula (2)]]
R in the fluorosilane compounds shown in the general formula (2) 3～R 5For the carbon number that can be same to each other or different to each other is 1～12 organic group, except as the R in the general formula (1) 1And R 2The chain-like alkyl enumerated of example, cyclic alkyl, alkenyl, alkynyl, haloalkyl, alkyl, the aryl such as phenyl that can have alkyl, aralkyl, trialkylsilkl, trialkyl silica oxyalkyl with saturated heterocyclyl outside, can also enumerate carbonyls such as ethoxycarbonyl-ethyl; Carboxyls such as acetoxyl group, acetoxy-methyl, trifluoroacetyl oxygen base; Oxygen bases such as methoxyl group, ethyoxyl, propoxyl group, butoxy, phenoxy group, allyloxy; Amino such as allyl amino; Benzyl etc.
In the general formula (2), x representes 1～3 integer, and p, q and r represent 0～3 integer respectively, and 1≤p+q+r≤3.In addition, inevitably, x+p+q+r=4.
Example as the fluorosilane compounds shown in the general formula (2); Can enumerate single silicon fluoride classes such as trimethyl silicon fluoride, triethyl group silicon fluoride, tripropyl silicon fluoride, phenyl dimethyl silicon fluoride, triphenyl silicon fluoride, vinyl-dimethyl base silicon fluoride, vinyl diethyl silicon fluoride, vinyl diphenyl silicon fluoride, trimethoxy silicon fluoride, triethoxy silicon fluoride, and difluoro silanes such as dimethyl two silicon fluorides, diethyl two silicon fluorides, divinyl two silicon fluorides, ethyl vinyl two silicon fluorides; Silicofluoroform classes such as methyl trifluoro silane, ethyl silicofluoroform.
General formula (2) if shown in the fluorosilane compounds boiling point low, then because volatilization is difficult in nonaqueous electrolytic solution, contain the amount of regulation sometimes.In addition, contain in nonaqueous electrolytic solution after, because to discharge and recharge heating or the external environment condition of the battery that causes be might volatilize under the condition such as high temperature.Therefore, preferably at the compound that has boiling point more than 50 ℃ under 1 atmospheric pressure, wherein especially preferably has the compound of boiling point more than 60 ℃.
In addition; With the compound of general formula (1) likewise; As organic group; The group that carbon number is few is prone to show effect, and carbon number is that 1～6 alkenyl acts on filming of nonaqueous electrolytic solution or electrode surface and improves characteristics of output power, and aryl is caught the free radical that in battery, produces when discharging and recharging and had the effect that improves cell integrated performance.Therefore,,, be preferably methyl, vinyl or phenyl,, be preferably trimethyl silicon fluoride, vinyl-dimethyl base silicon fluoride, phenyl dimethyl silicon fluoride, vinyl diphenyl silicon fluoride etc. especially as the example of compound as organic group from this viewpoint.
[[compound shown in the general formula (3)]]
R in the compound shown in the general formula (3) 6～R 8For the organic group of the carbon number 1～12 that can be same to each other or different to each other,, can likewise enumerate as the R in the general formula (2) as its example 3～R 5Example and the chain-like alkyl enumerated, cyclic alkyl, alkenyl, alkynyl, haloalkyl, alkyl, the aryl such as phenyl that can have alkyl, aralkyl, trialkylsilkl, trialkyl silica oxyalkyl, carbonyl, carboxyl, oxygen base, amino, benzyl etc. with saturated heterocyclyl.
A in the compound shown in the general formula (3), so long as the group that is made up of H, C, N, O, F, S, Si and/or P gets final product, not special restriction as in the general formula (3) and the element oxygen atom Direct Bonding, is preferably C, S, Si or P.As the existing way of these atoms, preference is as being present in chain-like alkyl, cyclic alkyl, alkenyl, alkynyl, haloalkyl, carbonyl, sulfonyl, trialkylsilkl, phosphoryl, the phosphinyl etc.
In addition, the molecular weight of the compound shown in the general formula (3) is preferably below 1000, wherein is preferably especially below 800, more preferably below 500.As the example of the compound shown in the general formula (3), can enumerate HMDO, 1, silicone compounds classes such as 3-diethyl tetramethyl disiloxane, hexaethyldisiloxane, octamethyltrisiloxane; Alkoxyl silicone such as methoxytrimethylsilane, ethoxytrimethylsilane alkanes; The two peroxides such as (trimethyl silyls) of peroxidating; Carboxylic acid esters such as acetate trimethyl silyl ester, acetate triethylsilyl ester, propionic acid trimethyl silyl ester, methacrylic acid trimethyl silyl ester, trifluoroacetic acid trimethyl silyl ester; Sulfonic acid esterses such as methanesulfonic acid trimethyl silyl ester, ethyl sulfonic acid trimethyl silyl ester, methanesulfonic acid triethylsilyl ester, fluorine methanesulfonic acid trimethyl silyl ester; Sulfuric acid esters such as two (trimethyl silyl) sulfuric ester; Borate esters such as three (trimethylsiloxy) boron; Phosphoric acid such as three (trimethyl silyl) phosphate, three (trimethyl silyl) phosphite ester or phosphorous acid esters etc.
Wherein, preferred silicone compounds class, sulfonic acid esters, sulfuric acid ester, preferred especially sulfonic acid esters.As the silicone compounds class, preferred HMDO; As sulfonic acid esters, preferred methanesulfonic acid trimethyl silyl ester; As sulfuric acid ester, preferred two (trimethyl silyl) sulfuric esters.
[[compound that has the S-F key in the molecule]]
As the compound that has the S-F key in the molecule, not special the qualification, but be preferably sulfuryl fluoride class, fluosulfonic acid ester class.
For example can enumerate Fumette, second sulfuryl fluoride, methane two (sulfuryl fluoride), ethane-1,2-two (sulfuryl fluoride), propane-1,3-two (sulfuryl fluoride), butane-1; 4-two (sulfuryl fluoride), difluoromethane two (sulfuryl fluoride), 1,1,2,2-HFC-134a-1; 2-two (sulfuryl fluoride), 1,1,2,2; 3,3-HFC-236fa-1,3-two (sulfuryl fluoride), methyl fluorosulfonates, ethyl fluorosulfonate etc.Wherein, preferred Fumette, methane two (sulfuryl fluoride) or methyl fluorosulfonates.
[[nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate, propionate]]
As the counter cation of nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate, propionate, not special the qualification except metallic elements such as Li, Na, K, Mg, Ca, Fe, Cu, can also be enumerated with NR 9R 10R 11R 12(in the formula, R 9～R 12Represent that independently of one another hydrogen atom or carbon number are 1～12 organic group) expression ammonium, quaternary ammonium.Wherein, as R 9～R 12Carbon number be 1～12 organic group, can enumerate can by the substituted alkyl of halogen atom, can by the substituted cycloalkyl of halogen atom, can be by heterocyclic radical of the substituted aryl of halogen atom, nitrogen atom etc.As R 9～R 12, be preferably the heterocyclic radical of hydrogen atom, alkyl, cycloalkyl, nitrogen atom etc. respectively.In these counter cations, consider aspect the battery behavior when lithium secondary battery, using, be preferably lithium, sodium, potassium, magnesium, calcium or NR 9R 10R 11R 12, be preferably lithium especially.In addition, wherein, consider, be preferably nitrate or difluorophosphoric acid salt, be preferably difluorophosphate especially from power output raising rate or cycle characteristics aspect.In addition, these compounds can directly use the compound that in nonaqueous solvents, is synthesized in fact, also can in nonaqueous solvents, add synthetic in addition and separated in fact compound.
Specific compound; It is a kind of to be that the compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate or the propionate that have the S-F key in the compound shown in the fluorosilane compounds shown in the cyclic siloxane compound shown in the general formula (1), the general formula (2), the general formula (3), the molecule can use separately, also can be with combination arbitrarily and the compound of ratio combination use more than 2 kinds.In addition, in the specific compound, even in the compound of above-mentioned classification respectively, also can use separately a kind of, perhaps with combination arbitrarily and the compound of ratio combination use more than 2 kinds.
The ratio of these specific compounds in the nonaqueous electrolytic solution is with respect to whole nonaqueous electrolytic solutions, in total amount; Be necessary for 10ppm above (more than the 0.001 quality %); Be preferably more than the 0.01 quality %, more preferably more than the 0.05 quality %, further be preferably more than the 0.1 quality %.In addition, the upper limit is preferably below the 5 quality %, more preferably below the 4 quality %, further is preferably below the 3 quality %.If the concentration of specific compound is low excessively, then be difficult to obtain the raising effect of battery power output or the prolongation effect of battery life sometimes, on the other hand, if excessive concentration then causes the reduction of efficiency for charge-discharge sometimes.
In addition, if these specific compounds are then dismantled this battery and taken out nonaqueous electrolytic solution once more in secondary cell is made as actual confession of nonaqueous electrolytic solution, content wherein significantly reduces mostly.Therefore, by detecting above-mentioned specific compound at least also within the scope of the invention in the nonaqueous electrolytic solution of from battery, extracting out.The nonaqueous electrolytic solution that the present invention relates to can prepare through in nonaqueous solvents, dissolving electrolyte lithium salt, specific compound and other compound as required.During the preparation nonaqueous electrolytic solution, preferably in advance each raw material is dewatered, make moisture be generally below the 50ppm, be preferably below the 30ppm, be preferably below the 10ppm especially.
[other compound]
Nonaqueous electrolytic solution among the present invention contains in nonaqueous solvents as electrolytical lithium salts and the necessary composition of specific compound conduct, as required, in the scope of not damaging effect of the present invention, can also contain other compound of any amount.As this other compound, specifically, can enumerate following material, for example:
(1) aromatic compounds such as the partial hydrogenation thing of biphenyl, alkyl biphenyl, terphenyl, terphenyl, cyclohexyl benzene, tert-butyl benzene, tert-amyl benzene, diphenyl ether, dibenzofurans; 2-fluorine biphenyl, adjacent cyclohexyl fluorobenzene, to the partially fluorinated thing of above-mentioned aromatic compounds such as cyclohexyl fluorobenzene; 2,4-difluoroanisole, 2,5-difluoroanisole, 2,6-difluoroanisole, 3, fluorine-containing benzyl ether compounds such as 5-difluoroanisole etc. overcharge and prevent agent;
(2) negative poles such as vinylene carbonate, vinylethylene carbonate, fluorine ethylene carbonate, trifluoro propylene carbonate, succinyl oxide, glutaric anhydride, maleic anhydride, citraconic anhydride, glutaconic anhydride, itaconic anhydride, the cyclohexane dicarboxylic acid acid anhydride formation agent of filming;
(3) anodal protective agents such as the inferior propyl ester of glycol sulfite, sulfurous acid, dimethyl sulfite, propane sultone, butyl sultone, methyl mesylate, 1,4-dimethane sulfonoxybutane, toluenesulfonic acid methyl esters, dimethyl suflfate, ethyl sulfate, sulfolane, dimethyl sulfone, diethyl sulfone, dimethyl sulfoxide (DMSO), diethyl sulfoxide, tetramethylene sulfoxide, diphenyl sulfide, THIOANISOLE, diphenyl disulfide, two pyridine disulfides etc.
Prevent agent as overcharging, aromatic compounds such as the partial hydrogenation thing of preferred biphenyl, alkyl biphenyl, terphenyl, terphenyl, cyclohexyl benzene, tert-butyl benzene, tert-amyl benzene, diphenyl ether, dibenzofurans.They can make up and use more than 2 kinds.When combination was used more than 2 kinds, preferred especially cyclohexyl benzene or terphenyl (or its partial hydrogenation thing) and tert-butyl benzene or tert-amyl benzene combination were used.
As the negative pole formation agent of filming, preferred vinylene carbonate, vinylethylene carbonate, fluorine ethylene carbonate, succinyl oxide, maleic anhydride.They can make up and use more than 2 kinds.When combination is used more than 2 kinds, be preferably vinylene carbonate and vinylethylene carbonate, fluorine ethylene carbonate, succinyl oxide or maleic anhydride.As anodal protective agent, be preferably glycol sulfite, the inferior propyl ester of sulfurous acid, propane sultone, butyl sultone, methyl mesylate, methanesulfonic acid butyl ester.They can make up and use more than 2 kinds.In addition, especially preferably negative pole is filmed and form agent and the combination of anodal protective agent is used, and will overcharge and prevent that agent, negative pole from filming and form agent and the combination of anodal protective agent is used.
The ratio that contains to these other compounds in the nonaqueous electrolytic solution does not limit especially; With respect to whole nonaqueous electrolytic solutions, be preferably respectively more than the 0.01 quality %, more preferably 0.1 quality %; Further be preferably 0.2 quality %; Its upper limit is preferably below the 5 quality %, and more preferably 3 quality % further are preferably below the 2 quality %.Through adding these compounds, can suppress the breaking of battery/on fire when unusual causing, or capacity retention performance, cycle characteristics after high temperature is preserved are improved owing to overcharging.
For the preparation method of secondary cell of the present invention with nonaqueous electrolytic solution, not special the qualification can be dissolved lithium salts, specific compound, other compound as required according to conventional methods and prepared in nonaqueous solvents.
< electrolyte [1] >
In above-mentioned nonaqueous electrolytic solution, the nonaqueous solvents that preferably constitutes electrolyte is for contain the mixed solvent of " ethylene carbonate " at least, and ethylene carbonate is 1 capacity %～25 capacity % (electrolyte [1]) with respect to the ratio of nonaqueous solvents total amount.
The preparation methods of the kind of " lithium salts " among the present invention (electrolyte [1]), " ethylene carbonate (EC) nonaqueous solvents in addition ", " specific compound ", " other compound " and content thereof, service condition, nonaqueous electrolytic solution etc. are same as described above.
< electrolyte [2] >
In above-mentioned nonaqueous electrolytic solution, the nonaqueous solvents that preferably constitutes electrolyte contains " at least a asymmetric linear carbonate " and this asymmetric linear carbonate shared ratio that contains in whole nonaqueous solventss is 5 volume %～90 volume % (electrolyte [2]).
The preparation methods of the kind of " lithium salts " among the present invention (electrolyte [2]), " nonaqueous solvents beyond the asymmetric linear carbonate ", " specific compound ", " other compound " and content thereof, service condition, nonaqueous electrolytic solution etc. are same as described above.
Among the present invention (electrolyte [2]), in whole nonaqueous solventss, contain at least a asymmetric linear carbonate of 5 volume %～90 volume %.Further; All the content of at least a asymmetric linear carbonate in the nonaqueous solventss be preferably 8 volume % above, more preferably 10 volume % above, further be preferably 15 volume % above, more than the preferred especially 20 volume %; In addition the upper limit be preferably below the 85 volume %, more preferably below the 70 volume %, further be preferably below the 60 volume %, be preferably below the 45 volume % especially, preferably owing to have high low-temperature characteristics of the present invention and cycle characteristics etc. concurrently.
For asymmetric linear carbonate, not special the qualification, but be preferably asymmetric alkyl carbonate, the carbon number of preferred alkyl is 1～4.Object lesson as so asymmetric alkyl carbonate; For example can enumerate methyl ethyl carbonate, carbonic acid methyl n-pro-pyl ester, carbonic acid ethyl n-pro-pyl ester, carbonic acid isopropyl methyl ester, carbonic acid ethyl isopropyl esters, carbonic acid methyl n-butyl, carbonic acid ethyl n-butyl etc.Wherein, Be preferably methyl ethyl carbonate, carbonic acid methyl n-pro-pyl ester, carbonic acid ethyl n-pro-pyl ester, carbonic acid methyl n-butyl, carbonic acid ethyl n-butyl; More preferably methyl ethyl carbonate, carbonic acid methyl n-pro-pyl ester, carbonic acid methyl n-butyl are preferably methyl ethyl carbonate especially.These asymmetric linear carbonate can be mixed use more than 2 kinds.
As stated, nonaqueous solvents can mix use more than 2 kinds.Particularly consider, preferably except this asymmetric linear carbonate, further contain at least a cyclic carbonate from aspects such as the cycle characteristics of secondary cell, preservation characteristics raisings.When containing cyclic carbonate; Cyclic carbonate shared ratio in whole nonaqueous solventss is generally more than the 5 volume %, is preferably more than the 10 volume %, more preferably more than the 15 volume %, the upper limit is generally below the 50 volume %, is preferably below the 35 volume %, more preferably below the 30 volume %, further be preferably below the 25 volume % in addition.If cyclic carbonate shared ratio in whole nonaqueous solventss is very few, then might can not get the raising of the cycle characteristics or the preservation characteristics of secondary cell, on the other hand, if too much, then cryogenic discharging characteristic reduces sometimes.
In addition, consider, preferably except this asymmetric linear carbonate, further contain at least a symmetrical linear carbonate from the aspects such as raising of the balance of the cycle characteristics of secondary cell or preservation characteristics and cryogenic discharging characteristic.When containing symmetrical linear carbonate; Symmetry linear carbonate shared ratio in whole nonaqueous solventss is generally more than the 5 volume %, is preferably more than the 10 volume %, more preferably more than the 15 volume %; In addition, the upper limit is generally below the 80 volume %, is preferably below the 70 volume %, more preferably below the 50 volume %, further be preferably below the 40 volume %.If symmetrical linear carbonate shared ratio in whole nonaqueous solventss is very few, then can not get the raising of the balance of cycle characteristics or preservation characteristics and cryogenic discharging characteristic sometimes, on the other hand,, then can not get the cycle characteristics of excellence sometimes if too much.
In addition, the mixed solvent of preferred asymmetric linear carbonate and the nonaqueous solvents more than 2 kinds in addition.That is the above mixed solvent of 3 compositions that, preferably comprises this asymmetric linear carbonate.Mixed solvent as the nonaqueous solvents more than 2 kinds outside the asymmetric linear carbonate; Owing to can improve all batteries performances such as charge-discharge characteristic, battery life; So preferably with high dielectric constant solvent and low viscosity solvents combination uses such as symmetrical linear carbonate or chain ester such as cyclic carbonate or cyclic esters, the combination of preferred especially cyclic carbonate and symmetrical linear carbonate.The mixing ratio of this moment is not special to be limited; But consider from improving aspects such as cycle characteristics, preservation characteristics; Preferably with respect to the asymmetric linear carbonate of 100 parts by volume, high dielectric constant solvents such as cyclic carbonate or cyclic ester are that low viscosity solvents such as 10～400 parts by volume, symmetrical linear carbonate or chain ester are 10～800 parts by volume.
One of preferred compositions of the nonaqueous solvents more than 2 kinds outside the asymmetric linear carbonate is the combination that is the main body with cyclic carbonate and symmetrical linear carbonate.As the object lesson of the preferred compositions of cyclic carbonate and symmetrical linear carbonate, can enumerate ethylene carbonate and dimethyl carbonate, ethylene carbonate and diethyl carbonate, ethylene carbonate and dimethyl carbonate and diethyl carbonate etc.The ratio that contains in whole nonaqueous solventss does not limit especially, is that 10～35 volume %, symmetrical linear carbonate are 10～70 volume % but preferred asymmetric linear carbonate is 8～80 volume %, cyclic carbonate.
Can enumerate the combination that in the combination of these ethylene carbonates and symmetrical linear carbonate, further adds propylene carbonate makes up as preferred.When containing propylene carbonate, the Capacity Ratio of ethylene carbonate and propylene carbonate is preferably 99: 1～and 40: 60, be preferably 95: 5～50: 50 especially.
The another kind of the preferred compositions of the nonaqueous solvents more than 2 kinds outside the asymmetric linear carbonate is the combination that contains the chain ester.Particularly consider from the low-temperature characteristics raising aspect of battery, the preferred above-mentioned combination that contains cyclic carbonate and chain ester, as the chain ester, preferred especially methyl acetate, ethyl acetate etc.Chain ester shared ratio in whole nonaqueous solventss is preferably more than the 5 volume %, more preferably more than the 8 volume %, be preferably more than the 15 volume % especially, its upper limit is preferably below the 50 volume %, more preferably below the 35 volume %, further be preferably below the 30 volume %, be preferably below the 25 volume % especially.Therefore, in whole nonaqueous solventss, contain the preferred following ratio of ratio this moment: asymmetric linear carbonate is that 8～85 volume %, cyclic carbonate are that 10～35 volume %, chain ester are 5～50 volume %.
Can enumerate the combination that in the combination of these cyclic carbonates and chain ester, further adds symmetrical linear carbonate makes up as preferred.When containing symmetrical linear carbonate, all the ratio that contains of the symmetrical linear carbonate in the nonaqueous solventss is preferably 10～60 volume %.
As the object lesson of secondary cell of the present invention with the preferred compositions of the nonaqueous solvents of nonaqueous electrolytic solution; For example can enumerate: methyl ethyl carbonate and ethylene carbonate; Carbonic acid methyl n-pro-pyl ester and ethylene carbonate; Methyl ethyl carbonate, ethylene carbonate and propylene carbonate, the combination of asymmetric linear carbonate such as carbonic acid methyl n-pro-pyl ester, ethylene carbonate and propylene carbonate and cyclic carbonate; Methyl ethyl carbonate, ethylene carbonate and dimethyl carbonate; Methyl ethyl carbonate, ethylene carbonate and diethyl carbonate; Methyl ethyl carbonate, ethylene carbonate, diethyl carbonate and dimethyl carbonate; Carbonic acid methyl n-pro-pyl ester, ethylene carbonate and dimethyl carbonate; Carbonic acid methyl n-pro-pyl ester, ethylene carbonate and diethyl carbonate, the combination of asymmetric linear carbonate, cyclic carbonate and symmetrical linear carbonate such as carbonic acid methyl n-pro-pyl ester, ethylene carbonate, diethyl carbonate and dimethyl carbonate; Methyl ethyl carbonate, ethylene carbonate and methyl acetate, the combination of asymmetric linear carbonate, cyclic carbonate and chain esters such as methyl ethyl carbonate, ethylene carbonate and ethyl acetate; Methyl ethyl carbonate, ethylene carbonate, dimethyl carbonate and methyl acetate, the combination of asymmetric linear carbonate such as methyl ethyl carbonate, ethylene carbonate, diethyl carbonate and methyl acetate, cyclic carbonate, symmetrical linear carbonate and chain ester etc.
In this mixed solvent, contain lithium salts and be the above-mentioned specific compound difluorophosphoric acid salt for example more than the 10ppm with respect to the electrolyte gross mass; This asymmetric linear carbonate in whole nonaqueous solventss shared the containing nonaqueous electrolytic solution that ratio is 5 volume %～90 volume % owing to use cycle characteristics, cryogenic discharging characteristic, the high temperature preservation characteristics (residual capacity and high load capacity discharge capacity after particularly high temperature is preserved) of the secondary cell of its manufacturing and suppress the balance that gas produces and become excellent, thereby preferably.
< electrolyte [3] >
In above-mentioned nonaqueous electrolytic solution, the nonaqueous solvents that preferably constitutes electrolyte contains " more than one chain carboxylate " (electrolyte [3]) at least.
The preparation methods of the kind of " lithium salts " among the present invention (electrolyte [3]), " nonaqueous solvents beyond the chain carboxylate ", " specific compound ", " other compound " and content thereof, service condition, nonaqueous electrolytic solution etc. are same as described above.
As the chain carboxylate that uses among the present invention (electrolyte [3]), not special the qualification, the carbon that preferably comprises carboxyl is the Arrcostab of the carbon number 1～4 of 1～5 carboxylic acid at interior carbon number.In addition, do not limit, be preferably monocarboxylic acid or dicarboxylic acids for first number of above-mentioned carboxylic acid is special.
Wherein, be preferably fatty acid esters such as formic acid esters, acetic acid esters, propionic ester, butyrate; Various dicarboxylic ester classes etc., preferred especially acetic acid esters or propionic ester.
Specifically, preferred methyl acetate, ethyl acetate, propyl acetate, methyl propionate or ethyl propionate, preferred especially methyl acetate, ethyl acetate or methyl propionate.
In addition, these chain carboxylates can mix 2 kinds with on use.The combination that mixes is not special to be limited, and as preferred combination, can enumerate methyl acetate and ethyl acetate, methyl acetate and methyl propionate, ethyl acetate and methyl propionate, methyl acetate, ethyl acetate and methyl propionate etc.Thus, can regulate the balance of characteristics of output power and high temperature preservation characteristics etc. according to purpose.
When using the mixed solvent of above-mentioned chain carboxylate and nonaqueous solvents in addition; The chain carboxylate with respect to these whole nonaqueous solventss contain ratio be preferably more than the 3 volume %, more preferably more than the 5 volume %, further be preferably more than the 8 volume %, be preferably especially more than the 10 volume %; In addition; Its upper limit is preferably below the 50 volume %, more preferably below the 35 volume %, further be preferably below the 30 volume %, be preferably below the 25 volume % especially, preferably owing to have high low-temperature characteristics of the present invention and cycle characteristics etc. concurrently.
Though significantly improve the reason of low temperature characteristics of output power for using chain carboxylate and above-mentioned specific compound through combination also indeterminate; Even but the low-temperature characteristics that also might have when above-mentioned specific compound does not contain the chain carboxylate to a certain degree improves effect; Think that this is that the chain carboxylate has promoted this effect, in other words because electrode is had certain effect; Think because; Through existing in the yet high chain carboxylate of low temperature current downflow property, these specific compounds soak into to battery lead plate inside does not bring into play effect lavishly, and perhaps the chain carboxylate is propagated the interaction of above-mentioned specific compound and electrode.
< electrolyte [4] >
In the above-mentioned nonaqueous electrolytic solution, the nonaqueous solvents that preferably constitutes electrolyte contains the above solvent (electrolyte [4]) of flash-point more than 70 ℃ of 60 capacity % of whole nonaqueous solventss.
The preparation methods of the kind of " lithium salts " among the present invention (electrolyte [4]), " nonaqueous solvents beyond the solvent of flash-point more than 70 ℃ ", " specific compound ", " other compound " and content thereof, service condition, nonaqueous electrolytic solution etc. are same as described above.
Among the present invention, nonaqueous solvents must contain the above solvent of flash-point more than 70 ℃ of 60 capacity % of whole nonaqueous solventss in total amount.Further, preferably contain the solvent of flash-point more than 80 ℃ more than the 60 capacity % of whole nonaqueous solventss, especially preferably contain the solvent of flash-point more than 90 ℃ more than the 60 capacity % of whole nonaqueous solventss in total amount in total amount.
The solvent of flash-point more than 70 ℃ is not special to be limited; For example can enumerate; The preferred solvent of conduct such as ethylene carbonate, propylene carbonate, butylene carbonate, gamma-butyrolacton, gamma-valerolactone, wherein, preferred especially ethylene carbonate, propylene carbonate or gamma-butyrolacton.These solvents can use a kind of, also can mix more than 2 kinds and use, and its combination is not special to be limited.
In addition, consider, preferably contain ethylene carbonate or the composition of propylene carbonate more than the 10 capacity % with respect to whole nonaqueous solventss from cycle characteristics raising aspect.On the other hand, if contain a large amount of ethylene carbonates, then because low-temperature characteristics reduces, the content of ethylene carbonate is preferably below the 70 capacity % of whole nonaqueous solventss, is preferably below the 60 capacity % especially.
In total amount, the preferred example that contains the nonaqueous solvents of the above solvent of flash-point more than 70 ℃ of 60 capacity % of whole nonaqueous solventss is:
(1) gamma-butyrolacton shared amount in whole nonaqueous solventss is the nonaqueous solvents more than the 60 capacity %;
(2) total of ethylene carbonate and gamma-butyrolacton is all accounting for more than the 80 capacity % in the nonaqueous solventss, is preferably accounting for more than the 85 capacity % and the Capacity Ratio of ethylene carbonate and gamma-butyrolacton is 5: 95～45: 55 a nonaqueous solvents;
(3) total of ethylene carbonate and propylene carbonate is all accounting for more than the 80 capacity % in the nonaqueous solventss, is preferably accounting for more than the 85 capacity % and the Capacity Ratio of ethylene carbonate and propylene carbonate is 30: 70～60: 40 a nonaqueous solvents etc.
If use these nonaqueous solventss, then particularly the balance of cycle characteristics and heavy-current discharge characteristic etc. becomes excellent.
In addition, the preferred flash-point of nonaqueous electrolytic solution be more than 40 ℃, more preferably more than 50 ℃, further be preferably more than 60 ℃, be preferably more than 70 ℃ especially.If not the flash-point of water electrolysis liquid is low excessively, when then battery exposes at high temperature, worry igniting of electrolyte sometimes.
Secondary cell of the present invention can further cooperate flash-point less than 70 ℃ nonaqueous solvents composition (below abbreviate " other nonaqueous solvents composition " as) in the solvent of flash-point more than 70 ℃ with the nonaqueous solvents that uses in the nonaqueous electrolytic solution.Suitably select to use the solvent that other nonaqueous solvents composition like this can propose from the solvent as nonaqueous electrolytic solution in the past.For example can enumerate following nonaqueous solvents.
(1) linear carbonate
As linear carbonate, be preferably dialkyl carbonate, the carbon number that constitutes the alkyl of dialkyl carbonate is preferably 1～5 respectively, preferred especially 1～4.Specifically, for example can enumerate dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, carbonic acid di-n-propyl ester, methyl ethyl carbonate, carbonic acid methyl n-pro-pyl ester, carbonic acid ethyl n-pro-pyl ester.Wherein, preferred dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate.
(2) chain ester
Specifically, for example can enumerate methyl acetate, ethyl acetate, propyl acetate, methyl propionate etc.
(3) cyclic ether
Specifically, for example can enumerate oxolane, 2-methyltetrahydrofuran, oxinane etc.
(4) chain ether
Specifically, for example can enumerate dimethoxy-ethane, dimethoxymethane etc.
Other nonaqueous solvents composition can a kind ofly use with " solvent of flash-point more than 70 ℃ " combination, also can make up other nonaqueous solvents composition use more than 2 kinds.At this moment, particularly consider, preferably linear carbonate and/or chain ester are used with " solvent of flash-point more than 70 ℃ " combination from cycle characteristics and heavy-current discharge characteristic aspect.
Flash-point in whole nonaqueous solventss is that the content of the solvent more than 70 ℃ is necessary for more than the 60 capacity %, is preferably more than the 70 capacity %, more preferably more than the 75 capacity %, further is preferably more than the 80 capacity %, is preferably especially more than the 85 capacity %.In addition, its upper limit is preferably below the 100 capacity %, is preferably especially below the 90 capacity %.If flash-point is that the content of the solvent more than 70 ℃ is very few; Sometimes pressure-volume is prone to desired effects such as rising in can not get when then at high temperature preserving battery, on the other hand, if too much; Then owing to viscosity raises conductivity is reduced, the performance of lithium secondary battery reduces sometimes.
Though the reason for the rechargeable nonaqueous electrolytic battery that uses nonaqueous electrolytic solution of the present invention (electrolyte [4]) characteristics of output power excellence when using the high solvent of the above flash-point of certain amount is also indeterminate; But can think following reason, but the present invention should be not limited to following reason.That is, think and above-mentioned specific compound and electrode effect reduce the reaction resistance relevant, thereby improve characteristics of output power with the turnover of lithium ion.Think in addition; The high solvents of flash-point such as ethylene carbonate, propylene carbonate, butylene carbonate, gamma-butyrolacton, gamma-valerolactone are compared with linear carbonate; Dielectric constant is high, and when having the high solvent of above to a certain degree dielectric constant, it is remarkable that its effect becomes.Think further because; The battery capacity that the battery key element of taking in 1 battery case of secondary cell is had be 3 ampere-hours (Ah) when above and/or the DC resistance component of secondary cell be that 10 milliohms (Ω) are when following; The contribution of DC resistance component reduces; Compare with the battery that the contribution of DC resistance component is big, show the original effect of this nonaqueous electrolytic solution easily.
< electrolyte [5] >
In above-mentioned nonaqueous electrolytic solution, preferably contain LiN (C nF 2n+1SO 2) 2(in the formula, n is 1～4 integer) and/or two (oxalate closes) lithium borate are as the electrolyte (electrolyte [5]) of " lithium salts " that constitute electrolyte.
The preparation methods of " nonaqueous solvents ", " specific compound " among the present invention (electrolyte [5]), the kind of " other compound " and content thereof, service condition, nonaqueous electrolytic solution etc. are same as described above.
Secondary cell of the present invention is dissolved with lithium salts at least with nonaqueous electrolytic solution (electrolyte [5]) in nonaqueous solvents, as such lithium salts, contain and be selected from LiN (C nF 2n+1SO 2) 2At least a in (in the formula, n is 1～4 integer) and two (oxalate closes) lithium borate.They can use a kind of separately, also can use more than 2 kinds with combination and ratio combination arbitrarily.
Secondary cell is with in the nonaqueous electrolytic solution; Through using above (b) above-mentioned " specific compound " of 10ppm for following (a) combination; Can provide characteristics of output power significantly to improve, and high temperature preservation characteristics or the excellent nonaqueous electrolytic solution that is used for secondary cell of cycle characteristics.
(a) LiN (C nF 2n+1SO 2) 2(in the formula, n is 1～4 integer) and/or two (oxalate closes) lithium borate
As (a), not special qualification, LiN (CF 3SO 2) 2Or two (oxalate closes) lithium borate is preferred owing to can bring into play above-mentioned effect especially.
Secondary cell of the present invention as stated, as lithium salts, contains LiN (C with in the nonaqueous electrolytic solution nF 2n+1SO 2) 2(in the formula, n is 1～4 integer) and/or two (oxalate closes) lithium borate be as must composition, but also can make up in addition known in the past lithium salts of use (below abbreviate " other lithium salts " as).
As other lithium salts, not special the qualification for example can be enumerated following lithium salts.
Inorganic lithium salt: LiPF 6, LiBF 4, LiAsF 6, LiSbF 6Etc. inorganic fluoride salts; LiClO 4, LiBrO 4, LiIO 4Deng perhalide; LiAlCl 4Deng butter salt etc.
Fluorine-containing organic lithium salt: LiCF 3SO 3Etc. perfluoroalkanesulfosalt salt; LiC (CF 3SO 2) 3Deng perfluoroalkane sulfonymethyl salt; Li [PF 5(CF 2CF 2CF 3)], Li [PF 4(CF 2CF 2CF 3) 2], Li [PF 3(CF 2CF 2CF 3) 3], Li [PF 5(CF 2CF 2CF 2CF 3)], Li [PF 4(CF 2CF 2CF 2CF 3) 2], Li [PF 3(CF 2CF 2CF 2CF 3) 3] wait fluoroalkyl fluorinated phosphate salt etc.
Other oxalate closes the lithium borate class: the difluoro oxalate root closes lithium borate etc.
They can use a kind of separately, also can use more than 2 kinds with combination and ratio combination arbitrarily.In these " other lithium salts ", if comprehensively judge dissolubility in nonaqueous solvents, the charge-discharge characteristic during as secondary cell, characteristics of output power, cycle characteristics etc., then preferred LiPF 6, LiBF 4, preferred especially LiPF 6
LiN (C in the nonaqueous electrolytic solution nF 2n+1SO 2) 2(in the formula; N is 1～4 integer) and/or the concentration of two (oxalate closes) lithium borate when these salt are used as main salt; Be generally 0.3mol/L above, be preferably 0.5mol/L above, more preferably more than the 0.7mol/L, its upper limit is generally below the 2mol/L, is preferably below the 1.8mol/L, more preferably below the 1mol/L.In addition, with LiPF 6, LiBF 4When waiting other lithium salts to use as main salt, LiN (C nF 2n+1SO 2) 2(in the formula; N is 1～4 integer) and/or the concentration of two (oxalate closes) lithium borate be 0.001mol/L above, be preferably 0.01mol/L above, more preferably more than the 0.03mol/L; In addition, its upper limit is generally below the 0.3mol/L, is preferably below the 0.2mol/L, more preferably below the 0.1mol/L.Here said main salt is meant the maximum lithium salts of concentration in nonaqueous electrolytic solution.
The total concentration of the lithium salts in the nonaqueous electrolytic solution, not special the qualification, but be generally 0.5mol/L above, be preferably 0.6mol/L above, more preferably more than the 0.7mol/L.In addition, its upper limit is generally below the 2mol/L, is preferably below the 1.8mol/L, more preferably below the 1.7mol/L.If concentration is low excessively, then the conductivity of nonaqueous electrolytic solution is insufficient sometimes, and on the other hand, if excessive concentration, then because viscosity raises, and conductivity reduces sometimes, the performance of lithium secondary battery reduces sometimes.
Preferred example when lithium salts more than 2 kinds is used in combination is with being selected from LiN (C nF 2n+1SO 2) 2At least a lithium salts and LiPF in (in the formula, n is 1～4 integer) and two (oxalate closes) lithium borate 6Combination is used.Use through combination, particularly can improve characteristics of output power, preservation characteristics.This moment be selected from LiN (C nF 2n+1SO 2) 2(in the formula; N is 1～4 integer) and two (oxalate closes) lithium borate in the concentration of at least a lithium salts in nonaqueous electrolytic solution following: when these lithium salts are used as main salt, be preferably 0.4mol/L above, more preferably 0.5mol/L above, be preferably more than the 0.6mol/L especially.Its upper limit is preferably below the 1.8mol/L, more preferably below the 1.5mol/L, be preferably below the 1.2mol/L especially.The LiPF of this moment 6Concentration be preferably 0.001mol/L above, more preferably 0.01mol/L above, be preferably more than the 0.1mol/L especially.In addition, its upper limit is at LiPF 6Than being selected from LiN (C nF 2n+1SO 2) 2In the low scope of the concentration of at least a lithium salts in (in the formula, n is 1～4 integer) and two (oxalate closes) lithium borate, be preferably below the 1mol/L, more preferably below the 0.8mol/L, be preferably below the 0.3mol/L especially.
With LiPF 6When using, be selected from LiN (C as main salt nF 2n+1SO 2) 2The concentration of at least a lithium salts in (in the formula, n is 1～4 integer) and two (oxalate closes) lithium borate be preferably 0.001mol/L above, more preferably 0.01mol/L above, be preferably more than the 0.03mol/L especially.In addition, its upper limit is preferably below the 0.3mol/L, more preferably below the 0.2mol/L, be preferably below the 0.1mol/L especially.The LiPF of this moment 6Concentration be preferably 0.5mol/L above, more preferably 0.6mol/L above, be preferably more than the 0.7mol/L especially.In addition, its upper limit is preferably below the 1.8mol/L, more preferably below the 1.7mol/L, be preferably below the 1.5mol/L especially.
In addition, if be selected from LiN (C at this nF 2n+1SO 2) 2At least a lithium salts and LiPF in (in the formula, n is 1～4 integer) and two (oxalate closes) lithium borate 6Combination in combination use LiBF 4, then owing to have and suppress that Yin Gaowen preserves the effect of the deterioration that causes and preferred.At this moment, LiBF 4Concentration be generally 0.001mol/L above, be preferably 0.01mol/L above, more preferably more than the 0.03mol/L, its upper limit is generally below the 0.4mol/L, is preferably below the 0.15mol/L, more preferably below the 0.1mol/L.
Contain LiN (C nF 2n+1SO 2) 2(in the formula; N is 1～4 integer) and/or two (oxalate closes) lithium borate and the compound that is selected from the compound that has the S-F key in the chain compound that has structure shown in the general formula (3) in the compound shown in the cyclic compound shown in the above-mentioned general formula (1), the above-mentioned general formula (2), the molecule, the molecule, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate, the propionate in the nonaqueous electrolytic solution of at least a compound; Because the balance of the cycle characteristics of the battery that this nonaqueous electrolytic solution of use is made and high temperature preservation characteristics (residual capacity and high load capacity discharge capacity after particularly high temperature is preserved) becomes excellent, so preferred.
Though the excellent reason of excellent and high temperature keeping quality or cycle characteristics is also indeterminate for the output characteristic of the rechargeable nonaqueous electrolytic battery that uses nonaqueous electrolytic solution of the present invention; But can think because above-mentioned specific compound has certain effect to electrode; Reduce the reaction resistance relevant, thereby improve characteristics of output power with the turnover of lithium ion.Wherein infer, through using LiN (C nF 2n+1SO 2) 2(in the formula; N is 1～4 integer) and/or two (oxalate closes) lithium borate as lithium salts, these lithium salts moderately react on negative pole and anodal surface, form the excellent stable composite protection of lithium ion permeability derive from this lithium salts with other nonaqueous electrolytic solution composition and film; Through this compelx coating; Suppress the active high electrode and the unnecessary side reaction of nonaqueous electrolytic solution, thereby improve characteristics of output power, high temperature preservation characteristics and cycle characteristics improve simultaneously.
< electrolyte [6] >
In the above-mentioned nonaqueous electrolytic solution, the lithium salts that preferably constitutes electrolyte is fluorine-containing lithium salts, and in whole nonaqueous electrolytic solutions, contains the hydrogen fluoride (HF) (electrolyte [6]) of 10ppm～300ppm.
The preparation methods of " nonaqueous solvents ", " specific compound " among the present invention (electrolyte [6]), the kind of " other compound " and content thereof, service condition, nonaqueous electrolytic solution etc. are same as described above.Among the present invention (electrolyte [6]), as " fluorine-containing lithium salts ", so long as known can getting final product as the electrolytical fluorine-containing lithium salts of secondary lithium batteries nonaqueous electrolytic solution, not special the qualification for example can be used above-mentioned lithium salts.They can use a kind of separately, also can use more than 2 kinds with combination and ratio combination arbitrarily.Wherein, from easily after state in the presence of the alcohols viewpoint that generates hydrogen fluoride (HF), preferred LiPF 6, LiBF 4Deng.In addition, if comprehensively judge dissolubility in nonaqueous solvents, the charge-discharge characteristic when processing secondary cell, characteristics of output power, cycle characteristics etc., then preferred LiPF 6
In addition, except fluorine-containing lithium salts, can also mix the not fluorine-containing lithium salts of use in the electrolyte, as an example, can enumerate following lithium salts.
Inorganic lithium salt: LiClO 4, LiBrO 4, LiIO 4Deng perhalide; LiAlCl 4Deng butter salt etc.
Oxalate closes borate: two (oxalate closes) lithium borate etc.
The concentration of the above-mentioned lithium salts in the nonaqueous electrolytic solution is not special to be limited, and is generally more than the 0.5mol/L, is preferably more than the 0.6mol/L, more preferably more than the 0.7mol/L.In addition, its upper limit is generally below the 2mol/L, is preferably below the 1.8mol/L, more preferably below the 1.7mol/L.If concentration is low excessively, then the conductivity of nonaqueous electrolytic solution is insufficient sometimes, and on the other hand, if excessive concentration, then because viscosity raises, and conductivity reduces sometimes, the performance of lithium secondary battery reduces sometimes.
The concentration of the above-mentioned fluorine-containing lithium salts in the nonaqueous electrolytic solution is not special to be limited, but be generally 0.5mol/L above, be preferably 0.6mol/L above, more preferably more than the 0.7mol/L.In addition, its upper limit is generally below the 2mol/L, is preferably below the 1.8mol/L, more preferably below the 1.7mol/L.If concentration is low excessively; Then the generation insufficient sometimes or hydrogen fluoride (HF) of the conductivity of nonaqueous electrolytic solution is insufficient sometimes; On the other hand, if excessive concentration, then because the viscosity rising; Conductivity reduces sometimes or the generation of hydrogen fluoride (HF) is excessive sometimes carries out, and the performance of lithium secondary battery might reduce.
Fluorine-containing lithium salts in the nonaqueous electrolytic solution is with respect to the ratio of whole lithium salts, and with respect to whole lithium salts, preferred fluorine-containing lithium salts is more than the 50 quality %, is preferably more than the 70 quality % especially.In addition, the preferred especially lithium salts that mixes all is fluorine-containing lithium salts.If the ratio of fluorine-containing lithium salts is low excessively, then hydrofluoric generation is insufficient sometimes.
Lithium salts can use a kind of separately, also uses more than 2 kinds with combination arbitrarily and ratio combination, and a preferred example that makes up when using lithium salts more than 2 kinds is LiPF 6And LiBF 4Combination use, at this moment, LiBF 4Shared ratio is preferably 0.01 quality %～20 quality % in both amount to, more preferably 0.1 quality %～5 quality %.In addition, other preferred example uses inorganic fluoride salts and perfluoroalkane sulfimide salt for combination, and at this moment, inorganic fluoride salts shared ratio in both amount to is preferably 70 quality %～99 quality %, more preferably 80 quality %～98 quality %.This both combination is used to have and is suppressed the effect that Yin Gaowen preserves the deterioration that is caused.
In above-mentioned nonaqueous solvents, be dissolved with LiPF 6Etc. fluorine-containing lithium salts and in the nonaqueous electrolytic solution that obtains, contain hydrogen fluoride (HF) mostly.As the reason that contains hydrogen fluoride (HF), the hydrogen fluoride of the impurity in deriving from fluorine-containing lithium salts, also there be moisture or alcohols and the reaction of fluorine-containing lithium salts of the trace in the nonaqueous solvents and the hydrogen fluoride that generates.In the above-mentioned patent documentation 16, must do one's utmost to remove the hydrogen fluoride (HF) in the nonaqueous electrolytic solution, be preferably especially below the 15ppm, the cycle characteristics of the nonaqueous electrolytic solution of 9ppm is the most excellent result among the embodiment.
Under the present invention's (electrolyte [6]) the situation; Content as hydrogen fluoride (HF); Be generally 10ppm above, be preferably 12ppm above, more preferably 15ppm above, be preferably more than the 20ppm especially, and be generally below the 300ppm, be preferably below the 250ppm, more preferably below the 200ppm, be preferably below the 150ppm especially.If content is low excessively, then the effect of power output raising is insufficient sometimes, if content surpasses this scope, then sometimes power output and cycle characteristics is had harmful effect.
In order to contain hydrogen fluoride (HF); Can in the nonaqueous solvents of nonaqueous electrolytic solution or raw material, directly add; Perhaps utilize the nonaqueous electrolytic solution inside that is reflected at of water or alcohols and fluorine-containing lithium salts to produce; Therefore, can use and in nonaqueous electrolytic solution, add entry or alcohols, or in the nonaqueous solvents of raw material, contain the method that these one-tenth grade with suitable concentration in advance.At this moment, need sometimes to finish the regular hour to reaction.In other words; The fluorine-containing lithium salts of dissolving in the nonaqueous solvents that contains water or alcohols when preparation has added the electrolyte of specific compound, needs the time before the reaction of water or alcohols and fluorine-containing lithium salts finishes; But when using it for the battery manufacturing, can wait question response to finish.In the present invention, during as battery performance function, exist the hydrogen fluoride (HF) of certain concentration range to get final product, also can in battery, generate.When in the nonaqueous solvents of raw material, generating hydrogen fluoride (HF), also can in the part of the nonaqueous solvents that uses as raw material, generate hydrogen fluoride (HF), it is mixed with the nonaqueous solvents that does not contain water or alcohols.
In nonaqueous solvents, contain water or pure time-like in advance,, just contain the water or the alcohols of Duoing from beginning sometimes than necessary amount according to the purity of the solvent that uses.At this moment, preferably method purifying nonaqueous solvents such as separate out, remove and anhydrate or alcohols and using through adsorption treatment, distillation, crystallization.Can directly use to remove and anhydrate or alcohols, the water of residual ormal weight or the nonaqueous solvents of alcohols, also can hydrous water or alcohols being that ormal weight uses in the nonaqueous solvents of purifying.
Adsorption treatment be if can implement in that the state of liquid is next, can carry out purification process through dissolving in nonaqueous solventss such as aluminium oxide, active carbon, silica gel, molecular sieve (trade name) 4A and/or molecular sieve 5A or through the adsorbent that does not react with nonaqueous solvents.At this moment, also can distinguish the purified carbon dimethyl phthalate such be liquid raw material at normal temperatures, and ethylene carbonate such also can form liquid with other raw materials mix for the raw material of solid at normal temperatures, carry out purification process together.Contact method can be enumerated the method for flooding nonaqueous solvents continuously (below be called continuity method), or in nonaqueous solvents, adds adsorbent, leaves standstill or stirring method (below be called batch process).Under the situation of continuity method, be preferably 0.1～5/ hour in liquid hourly space velocity (LHSV) (LHSV) time of contact.In addition, the contact temperature is preferably 10～60 ℃.Under the situation of batch process, preferably add the adsorbent of 0.1～30 quality %, handled 0.25 hour～24 hours with respect to nonaqueous solvents.
In addition, normal temperature such as ethylene carbonate is separated out processing for the raw material of solid also can carry out crystallization down.Crystallization is separated out and can be used acetonitrile, acetone, toluene equal solvent to carry out.
This purification condition preferably suitably regulates according to kind or purity, the water of target or the content of alcohols of the raw material that uses.
When not adding hydrogen fluoride (HF) and preparing the present invention's (electrolyte [6]) nonaqueous electrolytic solution, contain water or alcohols at the nonaqueous solvents that is used for nonaqueous electrolytic solution.That is, add to use behind water or the alcohols or not remove and anhydrate or alcohols uses.Preferably contain alcohols particularly monobasic or di-alcohols.As alcohols, not special the qualification, first number of the kind of alkyl or alcohol is not special yet to be limited, and specifically, for example can enumerate unary alcohols such as methyl alcohol, ethanol, normal propyl alcohol, isopropyl alcohol, n-butanol, the tert-butyl alcohol; Di-alcohols such as ethylene glycol or propane diols; Ternary alcohols such as glycerine etc. are as preferred alcohols.When adding preferred " water or alcohols " especially, can enumerate methyl alcohol, ethanol, ethylene glycol, propane diols etc.
In the nonaqueous solvents of the used for electrolyte that uses, use because of its manufacture process etc. former thereby alcohols that sneak into to consider in industry it is preferred from aspects such as productivity, costs.Particularly preferably in containing methyl alcohol, ethanol, ethylene glycol or propane diols in the preferred nonaqueous solvents that uses.
At the nonaqueous solvents that is used for nonaqueous electrolytic solution of the present invention (electrolyte [6]); The content of hoping water or alcohols be 3ppm above, be preferably 10ppm above, more preferably 20ppm above, further be preferably more than the 30ppm, be limited to below the 150ppm on it, be preferably below the 130ppm, more preferably below the 120ppm, further be preferably below the 100ppm.If the content of water in the nonaqueous solvents or alcohols is very few, then can not fully obtain high-output power characteristic sometimes as characteristic of the present invention, if too much, cycle characteristics or high temperature preservation characteristics variation sometimes then.
Wherein, as unary alcohol, in nonaqueous solvents, be preferably more than the 5ppm, more preferably more than the 10ppm, further be preferably more than the 15ppm, and be preferably below the 100ppm, more preferably below the 80ppm, further be preferably below the 50ppm.In addition; As di-alcohols; In nonaqueous solvents for more than the 3ppm, be preferably more than the 10ppm, more preferably more than the 15ppm, further be preferably more than the 20ppm, and be preferably below the 100ppm, more preferably below the 90ppm, further be preferably below the 80ppm, be preferably below the 70ppm especially.In addition, water in nonaqueous solvents for more than the 3ppm, be preferably more than the 5ppm, more preferably more than the 10ppm, and be preferably below the 100ppm, more preferably below the 80ppm, further be preferably below the 70ppm.
If above-mentioned a certain amount of hydrogen fluoride (HF) and above-mentioned specific compound coexist in nonaqueous electrolytic solution, then can not bring harmful effect, and can improve the power output of lithium secondary battery cycle characteristics.
In nonaqueous electrolytic solution of the present invention through coexistence a certain amount of hydrogen fluoride (HF) though and specific compound can not bring harmful effect and improve the reason of power output also indeterminate to cycle characteristics, can think following reason.In addition, the invention is not restricted to the following action principle.That is, the power output that above-mentioned specific compound might have to a certain degree improves effect, and no matter the content of hydrogen fluoride (HF) how.Think that this is because specific compound has certain effect to the electrode of battery, has reduced the reaction resistance relevant with the turnover of lithium ion.Wherein, hydrogen fluoride (HF) might play enhancing or transmit the function of this effect.For example, specific compound and hydrogen fluoride (HF) one reacts on the function of electrode or specific compound hydrogen fluoride (HF) performance media when acting on electrode.In addition, think that the hydrogen fluoride (HF) of giving function like this can stably exist in battery, thus the harmful effects such as reduction that are difficult for bringing cycle characteristics.
< electrolyte [7] >
In above-mentioned nonaqueous electrolytic solution, preferably in electrolyte, contain vinylene carbonate, and the content of this vinylene carbonate is the scope (electrolyte [7]) of the 0.001 quality %～3 quality % of electrolyte gross mass.
The preparation methods of the kind of " lithium salts ", " nonaqueous solvents " among the present invention (electrolyte [7]), " specific compound ", " other compound " and content thereof, service condition, nonaqueous electrolytic solution etc. are same as described above.
Nonaqueous electrolytic solution of the present invention as stated, is characterized in that containing vinylene carbonate.In the present invention, vinylene carbonate shared ratio in whole nonaqueous electrolytic solutions be generally more than the 0.001 quality %, be preferably more than the 0.01 quality %, more preferably more than the 0.1 quality %.In addition, be generally below the 3 quality %, be preferably below the 2.8 quality %, more preferably below the 2.5 quality %.If the concentration of vinylene carbonate is low excessively, then be difficult to obtain the effect of improving of cycle characteristics sometimes, on the other hand, if excessive concentration then causes the low-temperature characteristics of battery to reduce sometimes.
The content of the vinylene carbonate in the nonaqueous electrolytic solution does not limit with respect to the content of above-mentioned specific compound is special; Be preferably more than 0.01 by quality ratio, more preferably more than 0.1, be preferably more than 0.3 especially; In addition, its upper limit is preferably below 300, more preferably below 100, be preferably below 30 especially.If obviously depart from this scope, then can not realize excellent cycle characteristics and the such purpose of low-temperature characteristics sometimes simultaneously.
For using through above-mentioned specific compound such as vinylene carbonate and difluorophosphoric acid salt is made up; Even vinylene carbonate is a small amount of; Though the reason that cycle characteristics also improves is also indeterminate; But think that its reason is: specific compounds such as difluorophosphoric acid salt have suppressed because discharging and recharging of battery and the amount of the vinylene carbonate that consumes at positive pole, and vinylene carbonate can not form at negative pole lavishly and film; And mix through specific compound such as difluorophosphoric acid salt and vinylene carbonate, the matter of filming that forms at negative pole changes, the filming of high-quality that forms thin, low resistance and can further significantly suppress the decomposition of electrolyte lithium salt.Thereby think the improvement that can also realize low-temperature characteristics.
< electrolyte [8] >
In above-mentioned nonaqueous electrolytic solution; Preferably in electrolyte, further contain at least a compound that is selected from the compound shown in the above-mentioned general formula (4), the heterocyclic compound that contains nitrogen and/or sulphur, cyclic carboxylic esters, the fluorine-containing cyclic carbonate, and its content range in whole nonaqueous electrolytic solutions is 0.001 quality %～5 quality % (electrolyte [8]).
The preparation methods of the kind of " lithium salts ", " nonaqueous solvents " among the present invention (electrolyte [8]), " specific compound ", " other compound " and content thereof, service condition, nonaqueous electrolytic solution etc. are same as described above.
In the present invention's (electrolyte [8]) the nonaqueous electrolytic solution; Further contain at least a compound (following sometimes they are abbreviated as " specific compound B ") that is selected from the compound shown in the above-mentioned general formula (4), the heterocyclic compound that contains nitrogen and/or sulphur, cyclic carboxylic esters, the fluorine-containing cyclic carbonate, and its content range in whole nonaqueous electrolytic solutions is 0.001 quality %～5 quality %.
[[compound shown in the general formula (4)]]
In the above-mentioned general formula (4), R 9～R 12The group that more than one the element by being selected among H, C, N, O, F, S and the P that expression can be same to each other or different to each other constitutes.
Existing way as these atoms; Specifically, preferably be present in hydrogen atom, fluorine atom, alkyl, cycloalkyl, alkenyl, alkynyl, haloalkyl, alkoxyl, carbonyl, carbonyl oxygen base, oxygen base carbonyl, oxygen base carbonyl oxygen base, sulfonyl, oxygen base sulfonyl, sulfonyloxy, phosphoryl, the phosphinyl etc.In addition, the molecular weight of compound shown in the general formula (4) is preferably below 500, wherein more preferably below 300, further be preferably below 200.
As the object lesson of compound shown in the general formula (4), can enumerate carbonates such as vinylethylene carbonate, divinyl ethylene carbonate, carbonic acid methyl ethylene ester, carbonic acid cyclic olefin copolymers, ethylvinyl, carbonic acid propyl ethylene base ester, carbonic acid divinyl ester, carbonic acid allyl methyl ester, carbonic acid pi-allyl ethyl ester, carbonic acid pi-allyl propyl diester, carbonic acid diallyl ester; Ester classes such as vinyl acetate, propionate, vinyl acrylate, butenoic acid vinyl acetate, metering system vinyl acetate, allyl acetate, allyl propionate, methyl acrylate, ethyl acrylate, propyl acrylate, methyl methacrylate, EMA, propyl methacrylate; Sulfone classes such as divinylsulfone, methyl ethylene sulfone, ethyl vinyl sulfone, propyl ethylene base sulfone, diallyl sulfone, allyl methyl sulfone, pi-allyl ethyl sulfone, pi-allyl propyl group sulfone; Sulfurous esters such as divinyl sulfite, methyl ethylene sulfite, ethyl vinyl sulfite, diallyl sulfite; Sulfonic acid esterses such as vinyl methanesulfonates, vinyl esilate, pi-allyl methanesulfonates, pi-allyl esilate, methyl ethylene sulphonic acid ester, ethyl vinyl sulphonic acid ester; Sulfuric acid esters such as divinyl sulfuric ester, methyl ethylene sulfuric ester, ethyl vinyl sulfuric ester, diallyl sulfuric ester etc.Wherein, special preferred vinyl ethylene carbonate, divinyl ethylene carbonate, vinyl acetate, propionate, vinyl acrylate, divinylsulfone, vinyl methanesulfonates etc.
[[heterocyclic compound that contains nitrogen and/or sulphur]]
As containing nitrogen and / or sulfur containing heterocyclic compound is not particularly limited, and examples thereof include 1 - methyl-2 - pyrrolidone, 1,3 - dimethyl-2 - pyrrolidone, 1,5 - dimethyl- - pyrrolidone, 1 - ethyl-2 - pyrrolidone, 1 - cyclohexyl-2 - pyrrolidone, pyrrolidone; 3 - methyl -2 - oxazolidinone 3 - ethyl -2 -
Figure BDA0000087738240001952
oxazolidinone 3 - cyclohexyl -2 - oxazolidinone, etc.
Figure BDA0000087738240001954
oxazolidinone; 1 - Methyl-2 - piperidone, 1 - ethyl-2 - piperidone piperidine ketone, etc.; 1,3 - dimethyl-2 - imidazole morpholine, 1,3 - diethyl-2 - imidazolidinone imidazolinone; sulfolane 2 - methyl sulfolane, 3-- methyl sulfolane sulfolane; sulfolene; ethylene sulfite , esters such as propylene sulfite, sulfite esters; 1,3 - propane sultone, 1 - methyl-1 ,3 - propane sultone 3 - methyl-1 - propanesulfonic acid lactone, 1,4 - butane sultone, 1,3 - propene sultone, 1,4 - butylene acid lactone sulfonate esters.Wherein, preferred especially 1-Methyl-2-Pyrrolidone, 1-methyl-2-piperidones, 1,3-N-morpholinopropanesulfonic acid lactone, 1,4-butyl sultone, 1,3-propene sulfonic acid lactone, 1,4-butylene sultones etc.
[[cyclic carboxylic esters]]
As cyclic carboxylic esters; Not special the qualification; For example can enumerate gamma-butyrolacton, gamma-valerolactone, γ-Ji Neizhi, γ-Geng Neizhi, γ-Xin Neizhi, nonyl lactone, γ-decalactone, γ-hendecane lactone, γ-dodecane lactone, Alpha-Methyl-gamma-butyrolacton, α-ethyl-gamma-butyrolacton, α-propyl group-gamma-butyrolacton, Alpha-Methyl-gamma-valerolactone, α-ethyl-gamma-valerolactone, α; Alpha-alpha-dimethyl-gamma-butyrolacton, α, alpha-alpha-dimethyl-gamma-valerolactone, δ-Wu Neizhi, δ-caprolactone, δ-Xin Neizhi, δ-nonalactone, δ-Gui Neizhi, δ-hendecane lactone, δ-dodecane lactone etc.Wherein, preferred especially gamma-butyrolacton, gamma-valerolactone etc.
[[fluorine-containing cyclic carbonate]]
As fluorine-containing cyclic carbonate, not special the qualification can be enumerated fluorine ethylene carbonate, difluoro ethylene carbonate, trifluoro ethylene carbonate, tetrafluoro ethylene carbonate, trifluoro propylene carbonate etc.Wherein, preferred especially fluorine ethylene carbonate etc.
Specific compound B; Promptly be selected from least a compound in the compound shown in the general formula (4), the heterocyclic compound that contains nitrogen and/or sulphur, cyclic carboxylic esters, the fluorine-containing cyclic carbonate can use separately a kind of, also can be with combination arbitrarily and the compound of ratio combination use more than 2 kinds.In addition, among the specific compound B, even the above-mentioned compound of classification respectively also can use a kind of separately or with combination arbitrarily and the compound of ratio combination use more than 2 kinds.
These specific compounds B is generally more than the 0.001 quality %, more preferably more than the 0.05 quality %, further be preferably more than the 0.1 quality % with respect to the ratio that contains of whole nonaqueous electrolytic solutions in total amount in the nonaqueous electrolytic solution.In addition, in total amount, its upper limit is generally below the 5 quality %, more preferably below the 4 quality %, further be preferably below the 3 quality %.If the concentration of specific compound B is low excessively, then be difficult to obtain the effect of improving of cycle characteristics and preservation characteristics sometimes, on the other hand, if excessive concentration then causes the reduction of efficiency for charge-discharge sometimes.
Though use the excellent reason of cryogenic discharging characteristic excellence and high temperature preservation characteristics or the cycle characteristics of rechargeable nonaqueous electrolytic battery of nonaqueous electrolytic solution of the present invention also indeterminate, can think following reason, but the invention is not restricted to the following action principle.That is, infer that its reason is following: specific compound B receives reduction decomposition during in the early stage charging on negative pole, on negative terminal surface, forms stable the filming that derives from specific compound B, can improve preservation characteristics, cycle characteristics.The increase of resistance at low temperatures is remarkable but this is filmed, the problem that exists cryogenic discharging characteristic to reduce.Through coexisting with specific compound A, suppress the excessive response of specific compound B, film even also form the excellent stable complex protection of lithium ion permeability at low temperatures, thereby improve cryogenic discharging characteristic and improve high temperature preservation characteristics or cycle characteristics.
Think further because; The battery capacity that the battery key element of taking in 1 battery case of secondary cell is had be 3 ampere-hours (Ah) when above and/or the DC resistance component of secondary cell be that 10 milliohms (Ω) are when following; The contribution of DC resistance component reduces; Compare with the battery that the contribution of DC resistance component is big, show the original effect of this nonaqueous electrolytic solution easily.
< electrolyte [9] >
In above-mentioned nonaqueous electrolytic solution, preferably in electrolyte, further containing overcharges prevents agent (electrolyte [9]).
The preparation methods of the kind of " lithium salts ", " nonaqueous solvents " among the present invention (electrolyte [9]), " specific compound ", " other compound " and content thereof, service condition, nonaqueous electrolytic solution etc. are same as described above.
The present invention's (electrolyte [9]) secondary cell is characterised in that with nonaqueous electrolytic solution containing overcharges prevents agent.Prevent agent as overcharging, not special qualification the, but the compound shown in preferably following (1), (2) or (3) etc.
(1) can be by alkyl and/or the substituted biphenyl of fluorine atom, terphenyl, diphenyl ether or dibenzofurans;
(2) the partial hydrogenation thing of terphenyl;
(3) by the substituted benzene of tertiary alkyl, cycloalkyl, fluorine atom and/or methoxyl group.
As the compound of (1), not special the qualification for example can be enumerated phenyl ring such as biphenyl, alkyl biphenyl, terphenyl and connected compounds; Fluorine-containing phenyl ring such as 2-fluorine biphenyl connects compounds; Aromatic series ethers such as diphenyl ether; Heteroaromatics such as dibenzofurans connect compounds etc.
As the compound of (3), not special the qualification for example can be enumerated (ring) alkyl benzenes such as cyclohexyl benzene, tert-butyl benzene, tert-amyl benzene; Adjacent cyclohexyl fluorobenzene, to fluorine atom substituted benzenes such as cyclohexyl fluorobenzene; 2,4-difluoroanisole, 2,5-difluoroanisole, 2,6-difluoroanisole, 3,5-difluoroanisole etc. contains fluoroanisole class etc.
As preferred object lesson, can enumerate the aromatic compound such as partial hydrogenation thing, cyclohexyl benzene, tert-butyl benzene, tert-amyl benzene, diphenyl ether, dibenzofurans of biphenyl, alkyl biphenyl, terphenyl, terphenyl.These compounds are because the speed characteristics of the high temperature among the present invention after preserving are improved effect increases, thereby preferred especially.
Overcharge prevent agent can make up use two or more.When the combination use is two or more, especially preferably with cyclohexyl benzene or terphenyl (or its partial hydrogenation thing) and tert-butyl benzene or tert-amyl benzene combination use.
Here the partial hydrogenation thing of said terphenyl is meant the hydride that obtains at two keys top of the phenyl ring of terphenyl ground addition hydrogen.The partial hydrogenation thing of terphenyl can be the unification compound, also can be the mixture that contains a plurality of compounds.For example, can be the mixture of partial hydrogenation thing with 2 above terphenyls of different portions hydrogenation ratio, also can be the partial hydrogenation thing of the terphenyl that equates of partial hydrogenation rate.In addition, can also be different mixture of position of double bond or the mixture that contains constitutional isomer for the mixture of the different hydride in the position of the phenyl ring of hydrogenation.
The partial hydrogenation rate of terphenyl is meant; With not on two keys of the phenyl ring of terphenyl the partial hydrogenation rate of addition hydrogen as 0%, with the complete hydride of terphenyl promptly on all two keys during addition hydrogen the partial hydrogenation rate of when hydrogen atom of 18 moles of additions (in 1 mole the terphenyl) calculate as 100% and the value that obtains, be every mole of average value during mixture.For example, during the hydrogen atom of 2 moles of additions, the partial hydrogenation rate is 11.1% (=2/18) on 1 mole terphenyl.
When using the partial hydrogenation rate of above-mentioned definition, the partial hydrogenation rate of the partial hydrogenation thing of the terphenyl that uses among the present invention can be got and surpassed 0% and less than 100% value.The partial hydrogenation thing of terphenyl can contain the complete hydride (partial hydrogenation rate 100%) of terphenyl (partial hydrogenation rate 0%), meta-terphenyl, and the mole average portion hydrogenation ratio of mixture is preferably got and surpassed 0% and less than 100% value.Consider that aspect the preservation characteristics of battery and the dissolubility electrolyte the partial hydrogenation rate of terphenyl is preferably 30～70%, more preferably 35～60%.In addition,, do not have special the qualification, but be preferably the partial hydrogenation thing of meta-terphenyl or meta-terphenyl especially as the partial hydrogenation thing of terphenyl or terphenyl.
In the nonaqueous electrolytic solution these overcharge the ratio that prevents agent be generally respectively 0.01 quality % above, be preferably 0.1 quality % above, be preferably more than the 0.2 quality % especially, its upper limit is generally below the 5 quality %, is preferably below the 3 quality %, is preferably below the 2 quality % especially.If less than lower limit, the fail safe in the time of then can not fully guaranteeing to overcharge sometimes if surpass the upper limit, can not form the excellent battery of preservation characteristics even then mix with following specific compound sometimes.
Though be difficult for when having above-mentioned specific compound producing owing to the reason of the variation of speed characteristic after the preservation that overcharge additives caused is also indeterminate, supposition is following reason.In general; Prevent though overcharge that agent from can be when overcharging forming on anodal surface that polymerization is filmed and the internal resistance that significantly improves battery; The gas that produces during perhaps through this polymerization makes the inner current blocking device work of battery can; Improve the fail safe of secondary cell etc. thus, even but when the high temperature of charged state battery is preserved, also generating this polymerization of a part films, thus become the discharge capacity reduction of battery or the reason of speed characteristic variation.If there is the specific compound of appointment among the present invention therein, then compound effects is in anodal surface, and through forming weak shielding, suppressing to overcharge under the common charged state prevents the reaction of agent and positive active material.But when battery overcharge, positive pole became the state of overactivity, this weak shielding destroyed or anodally quickens with the reaction that prevents agent of overcharging, and surpasses the obstruction that forms through shielding, carries out polymerization reaction thus, fail safe in the time of can guaranteeing the overcharging of purpose.
<battery design (battery structure) >
Carry out detailed explanation in the face of the structure (battery structure) of lithium secondary battery of the present invention down.
The lithium secondary battery that discharges and recharges of the present invention at least by can occlusion and emit positive pole and negative pole, the above-mentioned nonaqueous electrolytic solution of lithium ion, micro-porous film dividing plate, current-collecting terminals and the shells etc. that are configured between positive pole and the negative pole constitute.Can also protection component be installed in the inside of battery and/or the outside of battery as required.And in this specification, the characteristic with the structure (battery structure) of lithium secondary battery of the present invention is called structure [1]～structure [6] sometimes.
[discharge capacity] (structure [3])
In the lithium secondary battery of the present invention; If it is the electric capacity (electric capacity when battery is discharged to discharge condition by fully charged state) that the battery key element of taking in 1 battery case of secondary cell is had (sometimes it being abbreviated as " battery capacity ") is more than 3 ampere-hours (Ah), then preferred because the raising effect of characteristics of output power increases.Therefore, it is 3 ampere-hours (Ah)～20Ah under full charging that positive plate is preferably designed to discharge capacity, more preferably 4Ah～10Ah (structure [3]).When being lower than 3Ah, when discharging big electric current, increase because the voltage that electrode reaction resistance is caused reduces, power efficiency is variation sometimes.On the other hand, during greater than 20Ah, though electrode reaction resistance reduces; Power efficiency improves, and the formed Temperature Distribution of inside battery heat release when still discharging and recharging owing to pulse is big, the poor durability of repeated charge; And for overcharging or also variation of the exothermal efficiency of the rapid heating when unusual such as internal short-circuit; In press liter, gas release valve work phenomenon (valve work) does not stop, to such an extent as to take place cell contents outwards sharply the probability of the phenomenon (breaking) of ejection might improve
[current collection structure] (structure [2], structure [4])
The current collection structure is not special to be limited, but for the raising of the characteristics of output power that more effectively realizes lithium secondary battery of the present invention, needs to form the structure of the resistance that reduces distribution part or bonding part.This internal resistance hour can be brought into play the effect of using above-mentioned nonaqueous electrolytic solution especially excellently.
When the electrode group is stated laminated construction after being, preferably use collector plate (current collection タ Block) harness with each electrode layer to be connected on the terminal and the structure that forms.Because when a cube electrode area increased, internal resistance increased, therefore a plurality of collector plates preferably are set in electrode reduces resistance.During winding-structure that the electrode group is stated after being, on anodal and negative pole, a plurality of collector plates are set respectively, harness can reduce internal resistance thus on terminal.
Through making above-mentioned current collection structural optimization, can reduce internal resistance as much as possible.In the battery that uses with big electric current, the impedance of measuring with the 10kHz alternating current method (below abbreviate " DC resistance component " as) is preferably below 20 milliohms (m Ω), more preferably below 10 milliohms (m Ω), further be preferably 5 milliohms (m Ω) following (structure [2]).On the other hand, less than 0.1 milliohm, though then the high-output power characteristic is improved, the shared ratio of the current collection structural material that is to use increases as if DC resistance component, and battery capacity reduces sometimes.
In the mensuration of impedance; The battery determinator 1470 of use SOLAR (ソ one ラ one ト ロ Application) manufactured and the frequency response analyzer 1255B of SOLAR manufactured are as determinator; Resistance when under the bias voltage of 5mV, applying the interchange of 10kHz is measured, as DC resistance component.
Above-mentioned nonaqueous electrolytic solution among the present invention produces effect with the relevant reaction resistance of the turnover of lithium in electrode active material for reducing, thereby can think that it becomes the main cause that can realize excellent characteristics of output power.But, in the big battery of common DC resistance component, hindered by DC resistance component, the effect that reaction resistance reduces can not 100% be reflected in the characteristics of output power.This problem can be improved through the little battery of use DC resistance component, thereby effect of the present invention can be given full play to.
In addition; Consider that from the effect of making the performance nonaqueous electrolytic solution and viewpoint especially preferably satisfying the electric capacity (electric capacity when battery is discharged to discharge condition by fully charged state) (battery capacity) that this condition and the above-mentioned battery key element of in 1 battery case of secondary cell, taking in had simultaneously is the condition more than 3 ampere-hours (Ah) with battery of high-output power characteristic.
Being connected preferably through any one of means of spot welds, high-frequency welding or ultrasonic bonding of above-mentioned collector plate and terminal engages (structure [4]).These welding methods were little, the easy welding methods of resistance in the past, but because long-time the use, reaction such as impurity in welding portion and the nonaqueous electrolytic solution or accessory substance and deterioration, DC resistance component increase.But; When use contains the above-mentioned nonaqueous electrolytic solution of specific compound, can form stable filming at welding portion, in addition; Can suppress the side reaction of nonaqueous electrolytic solution in positive pole; Even, can not increase DC resistance component and can keep high-output power so when long-time the use, the deterioration of welding portion also is difficult for carrying out.
[battery case 1] (structure 5)
The material of battery case is so long as get final product not special the qualification to the stable material of nonaqueous electrolytic solution that uses.Specifically, can use metal species such as nickel steel plating plate, stainless steel, aluminum or aluminum alloy, magnesium alloy, or the stack membrane of resin and aluminium foil (laminated film) is as preferred material.Consider from the lightweight aspect, especially preferably use the metal or the laminated film of aluminum or aluminum alloy.
In the present invention, when using above-mentioned nonaqueous electrolytic solution, especially preferably use the metal (structure [5]) of aluminum or aluminum alloy.The material that aluminum or aluminum alloy is a light weight, mouldability is high, but because when using for a long time as battery case, the deterioration with reaction such as impurity in the nonaqueous electrolytic solution or accessory substance is if variation then might reduce the intensity or the perforate of shell.When use contains the above-mentioned nonaqueous electrolytic solution of specific compound, can on aluminium surface or aluminum alloy surface, form stable filming, in addition, can suppress the side reaction of nonaqueous electrolytic solution on positive pole, so even long-time the use, the deterioration of shell also is difficult for carrying out.
For the shell that uses above-mentioned metal species, can enumerate through laser welding, resistance welded, ultrasonic bonding the metal welding is formed the shell that seals closed structure, or use above-mentioned metal species to form the shell of riveted structure through resin system packing ring.For the shell that uses above-mentioned laminated film, can enumerate through with resin bed each other heat fused form the shell etc. of sealing closed structure.In order to improve sealing, can between above-mentioned resin bed, exist with laminated film in the different resin of resin that uses.When particularly the resin bed heat fused being formed closed structure, owing to form engaging of metal and resin, therefore preferably use the modified resin conduct that has the resin of polar group or imported polar group to be present in the resin between the resin bed through current-collecting terminals.
[battery case 2] (structure [6])
Among the present invention; Form in the sheathing material of battery case, at least a portion of the inner face side of preferred battery comprises the sheet that uses thermoplastic resin and form, and this electrode is assembled into wherein; With this thermoplastic resin heat-sealing, can seal this battery pack (structure [6]) thus simultaneously.
In order to realize the battery lightweight; The material of the battery case of structure [6] situation is a light weight and for the stable material of using of nonaqueous electrolytic solution; Because must be easily and enclosed electrode group positively, so at least a portion of the inner face side of battery must contain the sheet that uses thermoplastic resin and form.
In the structure [6]; Seal this electrode group through thermoplastic resin is sealed, wherein, so-called " heat-sealing " is meant and makes thermoplastic resin each other on the basis of driving fit; Set the above temperature of fusing point of this thermoplastic resin, this thermoplastic resin is bonded to each other.The preferred use has banded heat generating part, and the sealer that can heat when pressurizeing.In addition, at least a portion of the inner face side of battery is used thermoplastic resin, and wherein, " at least a portion " is meant that the outer peripheral portion at sheet contains the zone that only can seal the part of this electrode group, can only use thermoplastic resin in heat seal lands.Consider that from the efficient aspect of the production process of sheet the whole sheet surface of the inner face side of preferred battery is covered by thermoplastic resin.
In addition; In structure [6]; After the micro-porous film dividing plate stated when having the character through the heating plugging hole; Fail safe aspect from overcharging etc. when unusual considers, sheathing material preferably contains the sheet that uses the obstruction that has than the hole of this micro-porous film dividing plate to begin the thermoplastic resin of the high fusing point of temperature and form at least a portion of the inner face side of battery.That is, when in overcharging etc., producing abnormal heating, battery temperature raises; If surpass the fusing point of the thermoplastic resin of sheathing material, to such an extent as to then exist battery case to break or the liquid leakage situation on fire that produces electrolysis, if but the micro-porous film dividing plate has the character through the heating plugging hole; Then owing to leak the hole plug of micro-porous film dividing plate before from sheathing material at the liquid that produces electrolysis; Therefore can suppress more heating, be unlikely to break, on fire, so preferred.Wherein, so-called fusing point is meant the fusion temperature of measuring through JIS K7121.
As the thermoplastic resin in the structure [6], not special the qualification can preferably be enumerated TPOs such as polyethylene, polypropylene, improved polyalkene, polyolefin copolymer; Polyesters such as PETG; Nylon etc. are polyamide-based etc.Thermoplastic resin can use a kind of, also can use more than 2 kinds.
As " at least a portion of sheathing material " in this structure [6], can only use thermoplastic resin, the composite material of still preferred use thermoplastic resin and heat-curing resin, elastomer, metal material, glass fiber, carbon fiber etc.In addition, can also contain packing materials such as filler.As composite material, the laminated of elemental metals such as special preferred thermoplastic resin layer and aluminium, iron, copper, nickel, titanium, molybdenum, gold or alloys such as stainless steel, the anti-corrosion Langaloy of haas troy, further not preferably and the laminated of the aluminum metal of excellent in workability.That is, sheathing material further preferably comprises the laminated that has aluminium lamination and thermoplastic resin layer laminate and obtain at least.These metal or alloy can use with the form of the paper tinsel of metal etc., also can use with the form of metal evaporation film.
In structure [6], use in the shell of above-mentioned sheathing material, can enumerate through the resin bed heat fused being formed the shell etc. of sealing closed structure.In order to improve sealing, can between above-mentioned resin bed, exist with sheathing material in the different resin of resin that uses.When particularly the resin bed heat fused being formed closed structure, owing to form engaging of metal and resin, therefore preferably use the modified resin conduct that has the resin of polar group or imported polar group to be present in the resin between the resin bed through current-collecting terminals.
In structure [6], the thickness of sheathing material is not special to be limited, but be preferably 0.03mm above, more preferably 0.04mm above, further be preferably more than the 0.05mm.In addition, its upper limit is preferably below the 0.5mm, more preferably below the 0.3mm, further be preferably below the 0.2mm.If sheathing material is thinner than this scope, then intensity reduces, but receives distortion, fragmentation etc. when having easily.On the other hand, if exterior material is thicker than this scope, then, do not reach the light-weighted purpose of battery sometimes because the quality of shell increases.
Use the battery of the structure [6] of above-mentioned sheathing material to have the high advantage of the degree of freedom of light weight, shape, on the other hand, if inside battery produces gas, then in voltage rise high, sheathing material is easy deformation sometimes.In the lithium secondary battery among the present invention; Specific compound in the nonaqueous electrolytic solution is adsorbed on the positive active material surface, can suppress anodal side reaction thus, and suppresses the generation of gas componant; Even therefore use above-mentioned sheathing material; Do not show above-mentioned shortcoming yet, only show the above-mentioned advantage of above-mentioned sheathing material, so preferred.
[micro-porous film dividing plate]
The micro-porous film dividing plate that uses among the present invention is so long as have the mechanical strength of the regulation that on electronics, two interpolars is insulated; The ion permeability is big; And have both getting final product with the join dividing plate of patience of reproducibility of patience and anticathode side of oxidizability of a side of positive pole, do not limit especially.As the material of micro-porous film dividing plate, use resin, inorganic matter, glass fiber etc. with this characteristic.
As above-mentioned resin, not special the qualification for example can be enumerated olefin polymer, fluorine-based polymer, cellulosic polymer, polyimides, nylon etc.Specifically, preferably from stable to nonaqueous electrolytic solution and protect the excellent material of fluidity and select, preferably use with TPOs such as polyethylene, polypropylene to be the porous chips of raw material or non-weaving cloth etc.As above-mentioned inorganic matter, not special the qualification for example can use aluminium oxide, silicon dioxide etc. oxide-based; Aluminium nitride or silicon nitride etc. are nitride-based; Sulfates such as barium sulfate, calcium sulfate etc.For shape, can use particle shape or fibrous.
As form, be preferably non-weaving cloth, weave cotton cloth, film shape such as little porous membrane.In the film shape, preferably using the aperture is that 0.01～1 μ m, thickness are the film of 5～50 μ m.Except above-mentioned independently the film shape, can use the composite porous layer that will contain above-mentioned inorganic particles to be formed on the form on the top layer of positive pole and/or negative pole with resinous adhesive.As such form, for example can enumerate on the two sides of positive pole, using fluororesin to form 90% particle diameter as adhesive is the porous layer that the aluminium oxide particles below the 1 μ m obtains.
The micro-porous film dividing plate that uses among the present invention preferably has the dividing plate through the character of heating plugging hole.The sheathing material that the thermoplastic resin that if above-mentioned micro-porous film dividing plate is used in combination and use the hole plug that has than this micro-porous film dividing plate to begin the high fusing point of temperature as at least a portion in the inner face side of battery of sheathing material forms; Then when abnormal heating such as overcharging, have can battery case break or electrolyte leakage before the effect that stops to generate heat.In addition; Here said " through the character of heating plugging hole "; Be meant that having formed the porous layer that electrolyte can move between both positive and negative polarity contains thermoplastic resin; And when the fusing point that is heated to this thermoplastic resin was neighbouring, this porous layer stopped up, the character that electrolyte can not move between both positive and negative polarity.
[cell shapes]
Do not limit cell shapes is special, can enumerate end cartridge type shape, end square configuration is arranged, slim shape, sheet, paper shape etc.When being assembled in system or the machine, improving taking in property in order to improve volumetric efficiency, can also be abnormity such as the shape of a hoof of taking in of considering the perimeter systems that is configured in battery circumferential, comb type shape.From the heat release of inside battery is considered preferably have at least one large-area smoother square configuration effectively to outside aspect.
In the battery that end cartridge type shape is arranged, owing to reduce with respect to the external surface area of the generating element of filling, the Joule heat that produces owing to internal resistance when therefore being preferably formed effectively with charge or discharge is discharged into outside design.In addition, be preferably designed to the filling ratio that improves the high material of thermal conductivity and reduce temperature inside and distribute.
The area S of preferred largest face is arranged in the end square configuration 1(remove wide and high product, the cm of unit of the overall dimension of portion of terminal 2) 2 times of ratio (2 * S with the thickness T (cm of unit) of battery profile 1/ T) value is more than 100, more preferably more than 200.Through increasing largest face, even be high-output power and jumbo battery, also can improve characteristics such as cyclicity or high temperature preservation, the exothermal efficiency in the time of can improving abnormal heating simultaneously, thus can suppress the precarious position of formation " breaking " or " on fire ".
[electrode group]
The electrode group can be after the micro-porous film dividing plate stated after clipping between the positive plate stated and the negative plate and the laminated construction electrode group that forms, and after the micro-porous film dividing plate stated after clipping between the positive plate stated and the negative plate be wound into any one of spiral helicine winding-structure electrode group.The volume of electrode group shared ratio (below abbreviate " electrode group occupation rate " as) in the volume of the jut that does not comprise battery case is preferably 0.3～0.7, and more preferably 0.4～0.6.Above-mentioned electrode group occupation rate was less than 0.3 o'clock, and battery capacity diminishes, in addition; If surpass 0.7, then because void space reduces the necessary volume of stating after can not fully guaranteeing of current collection structure; Cell resistance might increase; In addition, because battery forms high temperature, parts expand or the vapour pressure of electrolytical liquid component raises; Internal pressure raises, and has the situation that reduces or further internal pressure is released to outside gas release valve work as various characteristicses such as the repeated charge performance of battery or high temperature preservations.
In addition, when the electrode group is laminated construction, the summation L (cm of unit) of length and electrode area S around positive pole and the negative pole electrode 2(the cm of unit 2) ratio (L/ (2 * S of 2 times 2)) be below 1, more preferably below 0.5, further be preferably below 0.3.In addition, its lower limit is preferably more than 0.02, more preferably more than 0.03, further be preferably more than 0.05.Under the situation of laminated construction and since with approaching part around the electrode under the impact that causes because of residual stress or cut-out, the adhesiveness of electrode film might variation, therefore as L/ (2 * S 2) when surpassing above-mentioned scope, characteristics of output power reduces sometimes.In addition, if L/ (2 * S 2) be lower than above-mentioned scope, then cell area is excessive, and is also impracticable sometimes.
In addition, when the electrode group was winding-structure, the length of length direction that preferably should positive pole was 15～200 for the ratio of the length of Width.If this ratio is less than above-mentioned scope, what then have battery case has end cartridge type shape highly excessive with respect to floor space, balance variation and impracticable, perhaps positive electrode active material layer thickening and can not obtain the situation of high-output power.In addition, if this ratio is lower than above-mentioned scope, what then have battery case has end cartridge type shape highly too small with respect to floor space, and the balance variation is and impracticable, and perhaps the shared ratio of collector body increases, the situation that battery capacity reduces.
[anode electrode area] (structure [1])
In the present invention, when using above-mentioned nonaqueous electrolytic solution, from high-output power and the stable aspect when improving high temperature consider that the area of preferred positive electrode active material layer is bigger than the external surface area of battery case.Specifically; Can effectively the viewpoint that discharges and recharges the heating release that brings be considered from the raising of power output with through collector body; The summation of the electrode area of preferred above-mentioned positive pole is counted more than 15 times with the area ratio with respect to the surface area of the shell of secondary cell, more preferably (structure [1]) more than 20 times.The external surface area of so-called shell has under the situation of end square configuration, is meant the gross area of trying to achieve by except the size calculating by length and width and thickness of the shell part that is filled with the generating key element of the jut of terminal.Have under the situation of round-ended cylinder shape, be meant the geometrical surface that partly is approximately cylinder except the shell that is filled with the generating key element of the jut of terminal.The summation of the electrode area of so-called positive pole; Be meant and the geometrical surface that contains the opposed anodal plied timber layer of plied timber layer of negative electrode active material; On the two sides, forming in the structure of anodal plied timber layer, be meant the summation of the area that calculates each face respectively through the collector body paper tinsel.
[protection component]
As above-mentioned protection component; When the PTC (positive temperature coefficient, positive temperature coefficient) that resistance increases in the time of can enumerating abnormal heating or super-high-current and flow through, temperature fuse, thermistor, abnormal heating because the valve (current blocking valve) of the rapid rising of cell internal pressure or internal temperature and the electric current that flows through in the blocking circuit etc.Above-mentioned protection component preferably is chosen in the element of inoperation condition in the common use of high electric current, considers from the viewpoint of high-output power, more preferably forms the design that also is unlikely to abnormal heating or thermal runaway even without protection component.
[assembled battery]
Lithium secondary battery of the present invention is supplied when the practical application as power supply, is more than the single battery voltage for the voltage of power requirement mostly, must correspondingly use increasing apparatus that monocell is connected in series etc.Therefore, lithium secondary battery of the present invention is preferably processed its a plurality of Battery packs that form that are connected in series is used.Through forming Battery pack, reduce the resistance of coupling part, thereby can suppress to reduce as the power output of Battery pack.As Battery pack, consider from the supply voltage aspect, preferably be connected in series more than 5.
In addition, connect a plurality ofly when processing Battery pack, increase, therefore preferably have and be used for battery is remained on the cooling body below the uniform temperature owing to discharge and recharge the influence of the heating that brings.As battery temperature, be preferably 10 ℃～40 ℃, the preferred water cooling perhaps uses outer gas to cool off through air cooling.
[purposes]
Lithium secondary battery of the present invention and the Battery pack that a plurality of lithium secondary batteries of the present invention are formed by connecting; Owing to have high-output power, long-life, high security etc.; Therefore be preferred for being loaded on the vehicle, its power is at least in the purposes of the drive system of supply vehicle.
In addition, think above-mentioned specific compound, can suppress side reaction with electrolyte etc. through being adsorbed on positive active material surface or metal material surface.Think to be suppressed at the surperficial side reaction of positive active material through this, gas produces few, even use the sheathing material of sheet also to be difficult for causing the distortion of battery or the rising of interior pressure, so preferred.Think that in addition through suppressing the side reaction on positive active material surface, the life-span of battery, power output, the fail safe when overcharging improve, this helps the application in large-sized battery.Think in addition; Through suppressing the side reaction of metal material surface, in being connected of collector plate and terminal, even during little, the easy welding method of use resistance; Because the increase of DC resistance component is inhibited during long-term the use, therefore help the application in large-sized battery.Think that in addition reducing anodal reaction resistance is effectively in the battery that cell shapes or anodal area etc. is designed to high-output power, further improving power output, so preferred.
Embodiment
Below, enumerate embodiment and comparative example the present invention more specifically is described, but only otherwise exceed purport of the present invention, then the present invention does not receive the qualification of these embodiment.
Anodal [1] [positive active material]
The kind and the rerum natura of the positive active material that uses in following embodiment and the comparative example are following.
Anodal [1] table 1
[table 1]
Figure BDA0000087738240002061
In anodal [1] table 1,,, carry out BET specific area, average primary particle diameter (measuring), median particle diameter d with SEM according to the method for above-mentioned record as the rerum natura of positive active material 50, tap density mensuration.
[positive active material A]
Positive active material A is through the synthetic lithium-transition metal composite oxide of the method shown in following, uses composition formula LiMn 0.33Ni 0.33Co 0.33O 2Expression.With Mn: Ni: Co=1: 1: 1 molar ratio weighing is as the Mn of manganese raw material 3O 4, as the NiO of nickel raw material with as the Co (OH) of cobalt raw material 2, and process slurry to wherein adding pure water, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.2 μ m while stirring.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 5 μ m of particle diameter of manganese raw material, nickel raw material, cobalt raw material.In the granulation particle that obtains, add the LiOH powder of median particle diameter 3 μ m; And the ratio of the molal quantity that makes Li and the total mole number of Mn, Ni and Co is 1.05; Mix with high-speed mixer, obtain the granulation particle of nickel raw material, cobalt raw material, manganese raw material and the mixed-powder of lithium raw material.Under circulation of air, 950 ℃ to behind this mixed-powder sintering 12 hours (warming and cooling rate is 5 ℃/minute), pulverizes, and through the sieve of mesh 45 μ m, obtains positive active material A.
[positive active material B]
Positive active material B is the lithium-transition metal composite oxide likewise synthetic with positive active material A, uses composition formula LiMn 0.33Ni 0.33Co 0.33O 2Expression, its difference is: change spray-dired condition, process the granulation particle of the about 1 μ m of particle diameter, and sintering temperature is 930 ℃.
[positive active material C]
Positive active material C be according to the method shown in following synthetic in the surface attachment of positive active material A sulphur compound and antimonial and the positive active material that forms.That is, 96.7 weight portion positive active material A are stirred in flowing grooves, simultaneously to the 1.3 weight portion lithium sulfate (Li that wherein spray 2SO 4H 2O) the aqueous solution becomes spray form.In the mixture that obtains, add 2.0 weight portion antimony trioxide (Sb 2O 3, the particle median particle diameter is 0.8 μ m), fully mix.This mixture is transferred in the alumina container, under air atmosphere,, obtained positive active material C in 680 ℃ of sintering 2 hours.
[positive active material D]
Positive active material D is through the synthetic lithium-transition metal composite oxide of the method shown in following, uses composition formula Li 1.04Mn 1.84Al 0.12O 4Expression.With Li: Mn: Al=1.04: 1.84: 0.12 molar ratio weighing is as the LiOH of lithium raw material, as the Mn of manganese raw material 2O 3With AlOOH, and process slurry, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.5 μ m while stirring to wherein adding pure water as aluminum feedstock.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 10 μ m of particle diameter of lithium raw material, manganese raw material, aluminum feedstock.This granulation particle after nitrogen circulation, 900 ℃ of following sintering 3 hours (programming rate is 5 ℃/minute), is transformed into air with circulated gases by nitrogen, again at 900 ℃ of following sintering 2 hours (cooling rate is 1 ℃/minute).Behind the cool to room temperature, take out and pulverize,, obtain positive active material D through the sieve of mesh 45 μ m.
[positive active material E]
Positive active material E is commercially available article (the cobalt acid lithiums that Japanese chemical industrial company makes), is to use composition formula Li 103CoO 2The lithium and cobalt oxides of expression.
Anodal [1] embodiment 1
" anodal making "
In N crassitude ketone solvent, mix 90 quality % the positive active material A as positive active material, 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, using press to roll into thickness is 80 μ m, be cut into again have wide 100mm, the shape of the uncoated part of positive electrode active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of positive active material is 2.35g/cm 3, the value of (thickness of the positive electrode active material layer of one side)/(thickness of collector body) is 2.2.
" making of negative pole "
In 98 weight portion Delanium powder KS-44 (timcal (テ イ system カ Le) manufactured; Trade name) adds the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose be 1 quality %) of 100 weight portions in as the sodium carboxymethylcellulose of thickener; 2 weight portions are as the aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) of the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of negative electrode active material layer that long 104mm is big or small and wide 30mm, as negative pole.
" making of electrolyte "
Under the argon atmosphere of drying, in 3: 3: 4 the mixed solvent of volume ratio of ethylene carbonate (EC), dimethyl carbonate (DMC) and the methyl ethyl carbonate (EMC) of purifying, with the lithium hexafluoro phosphate (LiPF of the concentration dissolving intensive drying of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that contains 0.3 quality %.
" making of battery "
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject 20mL electrolyte, electrode is fully soaked into, seal and manufacture batteries.Anodal electrode area summation is 20.6 with the ratio of the long-pending summation of the case surface of battery.
" evaluation of battery "
(assay method of battery capacity)
To new battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.1V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.The 0.2C discharge capacity of the 5th circulation of this moment is as initial capacity.The result of cell evaluation is shown in positive pole [1] table 2.
(assay method of initial stage power output)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as power output (W).The result of cell evaluation is shown in positive pole [1] table 2.
(cyclic test (assay method of durable back battery capacity and durable back power output))
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.After being charged to charging upper voltage limit 4.1V with 2C constant-current constant-voltage method, be discharged to final discharging voltage 3.0V, as a charge and discharge cycles, carry out this circulation with this repeatedly, until 500 circulations with the constant current of 2C.Battery after finishing for cyclic test, the current value with 0.2C under 25 ℃ environment carries out discharging and recharging of 3 circulations, with the 0.2C discharge capacity of the 3rd circulation as durable back battery capacity.In addition, the battery for after the cyclic test end carries out output test, as durable back power output.The result of cell evaluation is shown in positive pole [1] table 2.
Anodal [1] embodiment 2
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 1.The result of cell evaluation is shown in positive pole [1] table 2.
Anodal [1] embodiment 3
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 1.The result of cell evaluation is shown in positive pole [1] table 2.
Anodal [1] embodiment 4
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 1.The result of cell evaluation is shown in positive pole [1] table 2.
Anodal [1] comparative example 1
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [1] embodiment 1.The result of cell evaluation is shown in positive pole [1] table 2.
Anodal [1] table 2
[table 2]
Figure BDA0000087738240002101
Anodal [1] embodiment 5
The positive active material that obtains except using positive active material A and positive active material B fully to mix with 2: 1 mass ratio is processed beyond the positive pole as positive active material, and [1] embodiment 1 implements equally with positive pole.The BET specific area of the positive active material of this mixing is 1.8m 2/ g, average primary particle diameter are 0.22 μ m, median particle diameter d 50Be 3.2 μ m, tap density is 1.5g/cm 2The result of cell evaluation is shown in positive pole [1] table 3.
Anodal [1] embodiment 6
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 5.The result of cell evaluation is shown in positive pole [1] table 3.
Anodal [1] embodiment 7
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 5.The result of cell evaluation is shown in positive pole [1] table 3.
Anodal [1] embodiment 8
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 5.The result of cell evaluation is shown in positive pole [1] table 3.
Anodal [1] comparative example 2
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [1] embodiment 5.The result of cell evaluation is shown in positive pole [1] table 3.
Anodal [1] table 3
[table 3]
Figure BDA0000087738240002111
Anodal [1] embodiment 9
Except using positive active material C as positive active material, process beyond the positive pole, implement equally with anodal [1] embodiment 1.The result of cell evaluation is shown in positive pole [1] table 4.
Anodal [1] embodiment 10
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 9.The result of cell evaluation is shown in positive pole [1] table 4.
Anodal [1] embodiment 11
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 9.The result of cell evaluation is shown in positive pole [1] table 4.
Anodal [1] embodiment 12
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 9.The result of cell evaluation is shown in positive pole [1] table 4.
Anodal [1] comparative example 3
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [1] embodiment 9.The result of cell evaluation is shown in positive pole [1] table 4.
Anodal [1] table 4
[table 4]
Figure BDA0000087738240002121
Anodal [1] embodiment 13
Use positive active material D as positive active material, process positive pole, using press to roll into thickness is 108 μ m, and use 28 should positive pole and 29 negative poles, in addition, with anodal [1] embodiment 1 manufacture batteries likewise.(thickness of the positive electrode active material layer thickness/positive electrode collector of anodal one side) is 3.1, and the summation of anodal electrode area is 18.1 with the ratio of the long-pending summation of the case surface of battery.The voltage range of solid measure is 3.0～4.2V, and the upper voltage limit of cyclic test is 4.2V, in addition, likewise estimates battery with anodal [1] embodiment 1.The result of cell evaluation is shown in positive pole [1] table 5.
Anodal [1] embodiment 14
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 13.The result of cell evaluation is shown in positive pole [1] table 5.
Anodal [1] embodiment 15
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 13.The result of cell evaluation is shown in positive pole [1] table 5.
Anodal [1] embodiment 16
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 13.The result of cell evaluation is shown in positive pole [1] table 5.
Anodal [1] comparative example 4
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [1] embodiment 13.The result of cell evaluation is shown in positive pole [1] table 5.
Anodal [1] table 5
[table 5]
Figure BDA0000087738240002131
Anodal [1] embodiment 17
The positive active material that uses positive active material D and positive active material E fully to mix with 2: 1 mass ratio and obtain is as positive active material; Process positive pole; Using press to roll into thickness is 94 μ m; And use 29 should positive pole and 30 negative poles, in addition, implement equally with anodal [1] embodiment 1.(thickness of the positive electrode active material layer thickness/positive electrode collector of anodal one side) is 2.6, and the summation of anodal electrode area is 18.7 with the ratio of the long-pending summation of the case surface of battery.In addition, the BET specific area of the positive active material of this mixing is 0.8m 2/ g, average primary particle diameter are 0.50 μ m, median particle diameter d 50Be 8.3 μ m, tap density is 2.5g/cm 3The result of cell evaluation is shown in positive pole [1] table 6.
Anodal [1] embodiment 18
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 17.The result of cell evaluation is shown in positive pole [1] table 6.
Anodal [1] embodiment 19
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 17.The result of cell evaluation is shown in positive pole [1] table 6.
Anodal [1] embodiment 20
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [1] embodiment 17.The result of cell evaluation is shown in positive pole [1] table 6.
Anodal [1] comparative example 5
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [1] embodiment 17.The result of cell evaluation is shown in positive pole [1] table 6.
Anodal [1] table 6
[table 6]
Figure BDA0000087738240002141
Result by anodal [1] table 2～positive pole [1] table 6 can know, in any positive pole, owing in electrolyte, all contain specific compound; Therefore; Power output, capability retention are improved, even and after cyclic test, also can fully keep battery capacity and power output.
Anodal [2] [positive active material]
The kind and the rerum natura of the positive active material that uses in following embodiment and the comparative example are following.
Anodal [2] table 1
[table 7]
Figure BDA0000087738240002142
In anodal [2] table 1,,, carry out BET specific area, average primary particle diameter (measuring), median particle diameter d with SEM according to the method for above-mentioned record as the rerum natura of positive active material 50, tap density mensuration.
[positive active material A]
Positive active material A is through the synthetic lithium-transition metal composite oxide of the method shown in following, uses composition formula Li 1.05Ni 0.80Co 0.15Al 0.05O 2Expression.With Ni: Co: Al=80: 15: 5 molar ratio weighing is as the NiO of nickel raw material, as the Co (OH) of cobalt raw material 2With AlOOH, and process slurry, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.25 μ m while stirring to wherein adding pure water as the Al raw material.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 10 μ m of particle diameter of nickel raw material, cobalt raw material, aluminum feedstock.In the granulation particle that obtains, add the LiOH powder of median particle diameter 3 μ m; And the ratio of the molal quantity that makes Li and the total mole number of Ni, Co and Al is 1.05; Mix with high-speed mixer, obtain the granulation particle of nickel raw material, cobalt raw material, aluminum feedstock and the mixed-powder of lithium raw material.Logical down at oxygen flow, 740 ℃ to behind this mixed-powder sintering 6 hours (warming and cooling rate is 5 ℃/minute), pulverizes, and through the sieve of mesh 45 μ m, obtains positive active material A.
[positive active material B]
Positive active material B is the lithium-transition metal composite oxide likewise synthetic with positive active material A, uses composition formula Li 1.05Ni 0.80Co 0.15Al 0.05O 2Expression, its difference is: change spray-dired condition, process the granulation particle of the about 1 μ m of particle diameter, and sintering temperature is 720 ℃.
[positive active material C]
Positive active material C be according to the method shown in following synthetic in the surface attachment of positive active material A sulphur compound and antimonial and the positive active material that forms.That is, 96.7 weight portion positive active material A are stirred in flowing grooves, simultaneously to the 1.3 weight portion lithium sulfate (Li that wherein spray 2SO 4H 2O) the aqueous solution becomes spray form.In the mixture that obtains, add 2.0 weight portion antimony trioxide (Sb 2O 3, the particle median particle diameter is 0.8 μ m), fully mix.This mixture is transferred in the alumina container, under air atmosphere,, obtained positive active material C in 680 ℃ of sintering 2 hours.
[positive active material D]
Positive active material D is through the synthetic lithium-transition metal composite oxide of the method shown in following, uses composition formula Li 1.03Ni 0.65Co 0.20Mn 0.15O 2Expression.With Li: Co: Mn=65: 20: 15 molar ratio weighing is as the Ni (OH) of nickel raw material 2, as the Co (OH) of cobalt raw material 2With Mn as the manganese raw material 2O 3, and process slurry to wherein adding pure water, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.2 μ m while stirring.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 12 μ m of particle diameter of nickel raw material, cobalt raw material, manganese raw material.In the granulation particle that obtains, add the LiOH powder of median particle diameter 3 μ m; And the ratio of the molal quantity that makes Li and the total mole number of Ni, Co and Mn is 1.05; Mix with high-speed mixer, obtain the granulation particle of nickel raw material, cobalt raw material, manganese raw material and the mixed-powder of lithium raw material.Under circulation of air, 950 ℃ to behind this mixed-powder sintering 12 hours (warming and cooling rate is 5 ℃/minute), pulverizes, and through the sieve of mesh 45 μ m, obtains positive active material D.
[positive active material E]
Positive active material E is through the synthetic lithium-transition metal composite oxide of the method shown in following, uses composition formula Li 1.04Mn 1.84Al 0.12O 4Expression.With Li: Mn: Al=1.04: 1.84: 0.12 molar ratio weighing is as the LiOH of lithium raw material, as the Mn of manganese raw material 2O 3With AlOOH, and process slurry, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.5 μ m while stirring to wherein adding pure water as aluminum feedstock.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 10 μ m of particle diameter of lithium raw material, manganese raw material, aluminum feedstock.This granulation particle after nitrogen circulation, 900 ℃ of following sintering 3 hours (programming rate is 5 ℃/minute), is transformed into air with circulated gases by nitrogen, again at 900 ℃ of following sintering 2 hours (cooling rate is 1 ℃/minute).Behind the cool to room temperature, take out and pulverize,, obtain positive active material E through the sieve of mesh 45 μ m.
Anodal [2] embodiment 1
" anodal making "
In N crassitude ketone solvent, mix 90 quality % the positive active material A as positive active material, 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, using press to roll into thickness is 66 μ m, be cut into again have wide 100mm, the shape of the uncoated part of positive electrode active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of positive active material is 2.35g/cm 3, the value of (thickness of the positive electrode active material layer of one side)/(thickness of collector body) is 1.7.
" making of negative pole "
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose be 1 quality %) of 100 weight portions in as the sodium carboxymethylcellulose of thickener; 2 weight portions are as the aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) of the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of negative electrode active material layer that long 104mm is big or small and wide 30mm, as negative pole.
" making of electrolyte "
Under the argon atmosphere of drying, in 3: 3: 4 the mixed solvent of volume ratio of ethylene carbonate (EC), dimethyl carbonate (DMC) and the methyl ethyl carbonate (EMC) of purifying, with the lithium hexafluoro phosphate (LiPF of the concentration dissolving intensive drying of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that contains 0.3 quality %.
" making of battery "
With 34 positive poles and 35 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject 20mL electrolyte, electrode is fully soaked into, seal and manufacture batteries.Anodal electrode area summation is 21.9 with the ratio of the long-pending summation of the case surface of battery.
" evaluation of battery "
(assay method of battery capacity)
To new battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.1V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.The 0.2C discharge capacity of the 5th circulation of this moment is as initial capacity.The result of cell evaluation is shown in positive pole [2] table 2.
(assay method of initial stage power output)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as power output (W).The result of cell evaluation is shown in positive pole [2] table 2.
(cyclic test (assay method of durable back battery capacity and durable back power output))
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.After being charged to charging upper voltage limit 4.1V with 2C constant-current constant-voltage method, be discharged to final discharging voltage 3.0V, as a charge and discharge cycles, carry out this circulation with this repeatedly, until 500 circulations with the constant current of 2C.Battery after finishing for cyclic test, the current value with 0.2C under 25 ℃ environment carries out discharging and recharging of 3 circulations, with the 0.2C discharge capacity of the 3rd circulation as durable back battery capacity.In addition, the battery for after the cyclic test end carries out output test, as durable back power output.The result of cell evaluation is shown in positive pole [2] table 2.
Anodal [2] embodiment 2
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 1.The result of cell evaluation is shown in positive pole [2] table 2.
Anodal [2] embodiment 3
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 1.The result of cell evaluation is shown in positive pole [2] table 2.
Anodal [2] embodiment 4
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 1.The result of cell evaluation is shown in positive pole [2] table 2.
Anodal [2] comparative example 1
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [2] embodiment 1.The result of cell evaluation is shown in positive pole [2] table 2.
Anodal [2] table 2
[table 8]
Figure BDA0000087738240002181
Anodal [2] embodiment 5
The positive active material that obtains except using positive active material A and positive active material B fully to mix with 2: 1 mass ratio is processed beyond the positive pole as positive active material, and [2] embodiment 1 implements equally with positive pole.The BET specific area of the positive active material of this mixing is 1.4m 2/ g, average primary particle diameter are 0.2 μ m, median particle diameter d 50Be 6.3 μ m, tap density is 1.9g/cm 2The result of cell evaluation is shown in positive pole [2] table 3.
Anodal [2] embodiment 6
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 5.The result of cell evaluation is shown in positive pole [2] table 3.
Anodal [2] embodiment 7
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 5.The result of cell evaluation is shown in positive pole [2] table 3.
Anodal [2] embodiment 8
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 5.The result of cell evaluation is shown in positive pole [2] table 3.
Anodal [2] comparative example 2
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [2] embodiment 5.The result of cell evaluation is shown in positive pole [2] table 3.
Anodal [2] table 3
[table 9]
Anodal [2] embodiment 9
Except using positive active material C as positive active material, process beyond the positive pole, implement equally with anodal [2] embodiment 1.The result of cell evaluation is shown in positive pole [2] table 4.
Anodal [2] embodiment 10
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 9.The result of cell evaluation is shown in positive pole [2] table 4.
Anodal [2] embodiment 11
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 9.The result of cell evaluation is shown in positive pole [2] table 4.
Anodal [2] embodiment 12
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 9.The result of cell evaluation is shown in positive pole [2] table 4.
Anodal [2] comparative example 3
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [2] embodiment 9.The result of cell evaluation is shown in positive pole [2] table 4.
Anodal [2] table 4
[table 10]
Figure BDA0000087738240002201
Anodal [2] embodiment 13
Use positive active material D as positive active material, process positive pole, using press to roll into thickness is 68 μ m, and use 34 should positive pole and 35 negative poles, in addition, with anodal [2] embodiment 1 manufacture batteries likewise.(thickness of the positive electrode active material layer thickness/positive electrode collector of anodal one side) is 1.8, and the summation of anodal electrode area is 21.9 with the ratio of the long-pending summation of the case surface of battery.The voltage range of solid measure is 3.0～4.2V, and the upper voltage limit of cyclic test is 4.2V, in addition, likewise estimates battery with anodal [2] embodiment 1.The result of cell evaluation is shown in positive pole [2] table 5.
Anodal [2] embodiment 14
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 13.The result of cell evaluation is shown in positive pole [2] table 5.
Anodal [2] embodiment 15
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 13.The result of cell evaluation is shown in positive pole [2] table 5.
Anodal [2] embodiment 16
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 13.The result of cell evaluation is shown in positive pole [2] table 5.
Anodal [2] comparative example 4
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [2] embodiment 13.The result of cell evaluation is shown in positive pole [2] table 5.
Anodal [2] table 5
[table 11]
Figure BDA0000087738240002211
Anodal [2] embodiment 17
The positive active material that uses positive active material A and positive active material E fully to mix with 2: 1 mass ratio and obtain is as positive active material; Process positive pole; Using press to roll into thickness is 76 μ m; And use 32 should positive pole and 33 negative poles, in addition, implement equally with anodal [2] embodiment 1.(thickness of the positive electrode active material layer thickness/positive electrode collector of anodal one side) is 2.0, and the summation of anodal electrode area is 20.6 with the ratio of the long-pending summation of the case surface of battery.In addition, the BET specific area of the positive active material of this mixing is 0.7m 2/ g, average primary particle diameter are 0.6 μ m, median particle diameter d 50Be 8.7 μ m, tap density is 2.2g/cm 3The result of cell evaluation is shown in positive pole [2] table 6.
Anodal [2] embodiment 18
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 17.The result of cell evaluation is shown in positive pole [2] table 6.
Anodal [2] embodiment 19
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 17.The result of cell evaluation is shown in positive pole [2] table 6.
Anodal [2] embodiment 20
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [2] embodiment 17.The result of cell evaluation is shown in positive pole [2] table 6.
Anodal [2] comparative example 5
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [2] embodiment 17.The result of cell evaluation is shown in positive pole [2] table 6.
Anodal [2] table 6
[table 12]
Figure BDA0000087738240002221
Result by anodal [2] table 2～positive pole [2] table 6 can know, in any positive pole, owing in electrolyte, all contain specific compound; Therefore; Power output, capability retention are improved, even and after cyclic test, also can fully keep battery capacity and power output.
Anodal [3] [positive active material]
The kind and the rerum natura of the positive active material that uses in following embodiment and the comparative example are following.
Anodal [3] table 1
[table 13]
Figure BDA0000087738240002231
In anodal [3] table 1,,, carry out BET specific area, average primary particle diameter (measuring), median particle diameter d with SEM according to the method for above-mentioned record as the rerum natura of positive active material 50, tap density mensuration.
[positive active material A]
Positive active material A is through the synthetic lithium-transition metal composite oxide of the method shown in following, uses composition formula Li 1.05Ni 0.8Co 0.2O 2Expression.With Ni: Co=80: 20 molar ratio weighing is as the NiO of nickel raw material with as the Co (OH) of cobalt raw material 2, and process slurry to wherein adding pure water, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.25 μ m while stirring.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 8 μ m of particle diameter of nickel raw material, cobalt raw material.In the granulation particle that obtains, add the LiOH powder of median particle diameter 3 μ m, and the ratio of the molal quantity that makes Li and the total mole number of Ni and Co is 1.05, mixes, obtain the granulation particle of nickel raw material, cobalt raw material and the mixed-powder of lithium raw material with high-speed mixer.Logical down at oxygen flow, 740 ℃ to behind this mixed-powder sintering 6 hours (warming and cooling rate is 5 ℃/minute), pulverizes, and through the sieve of mesh 45 μ m, obtains positive active material A.
[positive active material B]
Positive active material B is the lithium-transition metal composite oxide likewise synthetic with positive active material A, uses composition formula Li 1.05Ni 0.8Co 0.2O 2Expression, its difference is: change spray-dired condition, process the granulation particle of the about 1 μ m of particle diameter, and sintering temperature is 720 ℃.
[positive active material C]
Positive active material C be according to the method shown in following synthetic in the surface attachment of positive active material A sulphur compound and antimonial and the positive active material that forms.That is, 96.7 weight portion positive active material A are stirred in flowing grooves, simultaneously to the 1.3 weight portion lithium sulfate (Li that wherein spray 2SO 4H 2O) the aqueous solution becomes spray form.In the mixture that obtains, add 2.0 weight portion antimony trioxide (Sb 2O 3, the particle median particle diameter is 0.8 μ m), fully mix.This mixture is transferred in the alumina container, under air atmosphere,, obtained positive active material C in 680 ℃ of sintering 2 hours.
[positive active material D]
Positive active material D is through the synthetic lithium-transition metal composite oxide of the method shown in following, uses composition formula Li 1.04Mn 1.84Al 0.12O 4Expression.With Li: Mn: Al=1.04: 1.84: 0.12 molar ratio weighing is as the LiOH of lithium raw material, as the Mn of manganese raw material 2O 3With AlOOH, and process slurry, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.5 μ m while stirring to wherein adding pure water as aluminum feedstock.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 10 μ m of particle diameter of lithium raw material, manganese raw material, aluminum feedstock.This granulation particle after nitrogen circulation, 900 ℃ of following sintering 3 hours (programming rate is 5 ℃/minute), is transformed into air with circulated gases by nitrogen, again at 900 ℃ of following sintering 2 hours (cooling rate is 1 ℃/minute).Behind the cool to room temperature, take out and pulverize,, obtain positive active material D through the sieve of mesh 45 μ m.
Anodal [3] embodiment 1
" anodal making "
In N-crassitude ketone solvent, mix 90 quality % the positive active material A as positive active material, 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, using press to roll into thickness is 65 μ m, be cut into again have wide 100mm, the shape of the uncoated part of positive electrode active material layer that long 100mm is big or small and wide 30mm, process positive pole.The density of positive active material is 2.35g/cm 3, the value of (thickness of the positive electrode active material layer of one side)/(thickness of collector body) is 1.7.
" making of negative pole "
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose be 1 quality %) of 100 weight portions in as the sodium carboxymethylcellulose of thickener; 2 weight portions are as the aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) of the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of negative electrode active material layer that long 104mm is big or small and wide 30mm, as negative pole.
" making of electrolyte "
Under the argon atmosphere of drying, in 3: 3: 4 the mixed solvent of volume ratio of ethylene carbonate (EC), dimethyl carbonate (DMC) and the methyl ethyl carbonate (EMC) of purifying, with the lithium hexafluoro phosphate (LiPF of the concentration dissolving intensive drying of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that contains 0.3 quality %.
" making of battery "
With 34 positive poles and 35 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject 20mL electrolyte, electrode is fully soaked into, seal and manufacture batteries.Anodal electrode area summation is 21.9 with the ratio of the long-pending summation of the case surface of battery.
" evaluation of battery "
(assay method of battery capacity)
To new battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.1V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.The 0.2C discharge capacity of the 5th circulation of this moment is as initial capacity.The result of cell evaluation is shown in positive pole [3] table 2.
(assay method of initial stage power output)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as power output (W).The result of cell evaluation is shown in positive pole [3] table 2.
(cyclic test (assay method of durable back battery capacity and durable back power output))
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.After being charged to charging upper voltage limit 4.1V with 2C constant-current constant-voltage method, be discharged to final discharging voltage 3.0V, as a charge and discharge cycles, carry out this circulation with this repeatedly, until 500 circulations with the constant current of 2C.Battery after finishing for cyclic test, the current value with 0.2C under 25 ℃ environment carries out discharging and recharging of 3 circulations, with the 0.2C discharge capacity of the 3rd circulation as durable back battery capacity.In addition, the battery for after the cyclic test end carries out output test, as durable back power output.The result of cell evaluation is shown in positive pole [3] table 2.
Anodal [3] embodiment 2
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 1.The result of cell evaluation is shown in positive pole [3] table 2.
Anodal [3] embodiment 3
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 1.The result of cell evaluation is shown in positive pole [3] table 2.
Anodal [3] embodiment 4
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 1.The result of cell evaluation is shown in positive pole [3] table 2.
Anodal [3] comparative example 1
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [3] embodiment 1.The result of cell evaluation is shown in positive pole [3] table 2.
Anodal [3] table 2
[table 14]
Figure BDA0000087738240002261
Anodal [3] embodiment 5
The positive active material that obtains except using positive active material A and positive active material B fully to mix with 2: 1 mass ratio is processed beyond the positive pole as positive active material, and [3] embodiment 1 implements equally with positive pole.The BET specific area of the positive active material of this mixing is 1.8m 2/ g, average primary particle diameter are 0.2 μ m, median particle diameter d 50Be 4.3 μ m, tap density is 1.8g/cm 2The result of cell evaluation is shown in positive pole [3] table 3.
Anodal [3] embodiment 6
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 5.The result of cell evaluation is shown in positive pole [3] table 3.
Anodal [3] embodiment 7
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 5.The result of cell evaluation is shown in positive pole [3] table 3.
Anodal [3] embodiment 8
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 5.The result of cell evaluation is shown in positive pole [3] table 3.
Anodal [3] comparative example 2
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [3] embodiment 5.The result of cell evaluation is shown in positive pole [3] table 3.
Anodal [3] table 3
[table 15]
Figure BDA0000087738240002271
Anodal [3] embodiment 9
Except using positive active material C as positive active material, process beyond the positive pole, implement equally with anodal [3] embodiment 1.The result of cell evaluation is shown in positive pole [3] table 4.
Anodal [3] embodiment 10
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 9.The result of cell evaluation is shown in positive pole [3] table 4.
Anodal [3] embodiment 11
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 9.The result of cell evaluation is shown in positive pole [3] table 4.
Anodal [3] embodiment 12
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 9.The result of cell evaluation is shown in positive pole [3] table 4.
Anodal [3] comparative example 3
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [3] embodiment 9.The result of cell evaluation is shown in positive pole [3] table 4.
Anodal [3] table 4
[table 16]
Figure BDA0000087738240002281
Anodal [3] embodiment 13
The positive active material that uses positive active material A and positive active material D fully to mix with 2: 1 mass ratio and obtain is as positive active material; Process positive pole; Using press to roll into thickness is 74 μ m; And use 32 should positive pole and 33 negative poles, in addition, implement equally with anodal [3] embodiment 1.(thickness of the positive electrode active material layer thickness/positive electrode collector of anodal one side) is 2.0, and the summation of anodal electrode area is 20.6 with the ratio of the long-pending summation of the case surface of battery.The BET specific area of the positive active material of this mixing is 1.2m 2/ g, average primary particle diameter are 0.6 μ m, median particle diameter d 50Be 6.7 μ m, tap density is 2.2g/cm 2The result of cell evaluation is shown in positive pole [3] table 5.
Anodal [3] embodiment 14
Make the methanesulfonic acid trimethyl silyl ester that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 13.The result of cell evaluation is shown in positive pole [3] table 5.
Anodal [3] embodiment 15
Make the phenyl dimethyl silicon fluoride that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 13.The result of cell evaluation is shown in positive pole [3] table 5.
Anodal [3] embodiment 16
Make the difluorophosphate that electrolyte contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [3] embodiment 13.The result of cell evaluation is shown in positive pole [3] table 5.
Anodal [3] comparative example 4
In electrolyte, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [3] embodiment 13.The result of cell evaluation is shown in positive pole [3] table 5.
Anodal [3] table 5
[table 17]
Figure BDA0000087738240002291
Result by anodal [3] table 2～positive pole [3] table 5 can know, in any positive pole, owing in electrolyte, all contain specific compound; Therefore; Power output, capability retention are improved, even and after cyclic test, also can fully keep battery capacity and power output.
Anodal [4] [positive active material]
The kind and the rerum natura of the positive active material that uses in following embodiment and the comparative example are following.
Anodal [4] table 1
[table 18]
Figure BDA0000087738240002301
In anodal [4] table 1,,, carry out BET specific area, average primary particle diameter (measuring), median particle diameter d with SEM according to the method for above-mentioned record as the rerum natura of positive active material 50, tap density mensuration.
[positive active material A]
Positive active material A is through the synthetic lithium cobalt composite oxide of the method shown in following, uses composition formula LiCoO 2Expression.With Li: Co=1: 1 molar ratio weighing is as the LiOH of lithium raw material with as the Co (OH) of cobalt raw material 2, and process slurry to wherein adding pure water, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.2 μ m while stirring.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 9 μ m of particle diameter of lithium raw material, cobalt raw material.Under circulation of air, 880 ℃ to this granulation particles sintering 6 hours (warming and cooling rate is 5 ℃/minute).Behind the cool to room temperature, take out and pulverize,, obtain positive active material A through the sieve of mesh 45 μ m.
[positive active material B]
Positive active material B is the lithium-transition metal composite oxide likewise synthetic with positive active material A, uses composition formula LiCoO 2Expression, its difference is: change spray-dired condition, process the granulation particle of the about 1 μ m of particle diameter, and sintering temperature is 860 ℃.
[positive active material C]
Positive active material C be according to the method shown in following synthetic in the surface attachment of positive active material A sulphur compound and antimonial and the positive active material that forms.That is, 96.7 weight portion positive active material A are stirred in flowing grooves, simultaneously to the 1.3 weight portion lithium sulfate (Li that wherein spray 2SO 4H 2O) the aqueous solution becomes spray form.In the mixture that obtains, add 2.0 weight portion antimony trioxide (Sb 2O 3, the particle median particle diameter is 0.8 μ m), fully mix.This mixture is transferred in the alumina container, under air atmosphere,, obtained positive active material C in 680 ℃ of sintering 2 hours.
[positive active material D]
Positive active material D is through the synthetic lithium-transition metal composite oxide of the method shown in following, uses composition formula Li 1.04Mn 1.84Al 0.12O 4Expression.With Li: Mn: Al=1.04: 1.84: 0.12 molar ratio weighing is as the LiOH of lithium raw material, as the Mn of manganese raw material 2O 3With AlOOH, and process slurry, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.5 μ m while stirring to wherein adding pure water as aluminum feedstock.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 10 μ m of particle diameter of lithium raw material, manganese raw material, aluminum feedstock.This granulation particle after nitrogen circulation, 900 ℃ of following sintering 3 hours (programming rate is 5 ℃/minute), is transformed into air with circulated gases by nitrogen, again at 900 ℃ of following sintering 2 hours (cooling rate is 1 ℃/minute).Behind the cool to room temperature, take out and pulverize,, obtain positive active material D through the sieve of mesh 45 μ m.
Anodal [4] embodiment 1
" anodal making "
In N crassitude ketone solvent, mix 85 quality % the positive active material A as positive active material, 10 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, using press to roll into thickness is 85 μ m, be cut into again have wide 100mm, the shape of the uncoated part of positive electrode active material layer that long 100mm is big or small and wide 30mm, process positive pole.The density of positive active material is 2.35g/cm 3, the value of (thickness of the positive electrode active material layer of one side)/(thickness of collector body) is 2.3.
" making of negative pole "
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose be 1 quality %) of 100 weight portions in as the sodium carboxymethylcellulose of thickener; 2 weight portions are as the aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) of the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of negative electrode active material layer that long 104mm is big or small and wide 30mm, as negative pole.
" making of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixed solvent of 3: 3: 4 (volume ratio) of ethylene carbonate (EC), dimethyl carbonate (DMC) and the methyl ethyl carbonate (EMC) of purifying, with the lithium hexafluoro phosphate (LiPF of the concentration dissolving intensive drying of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that contains 0.3 quality %.
" making of battery "
With 31 positive poles and 32 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and manufacture batteries.Anodal electrode area summation is 20.0 with the ratio of the long-pending summation of the case surface of battery.
" evaluation of battery "
(assay method of battery capacity)
To new battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.2V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.The 0.2C discharge capacity of the 5th circulation of this moment is as initial capacity.The result of cell evaluation is shown in positive pole [4] table 2.
(assay method of initial stage power output)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as power output (W).The result of cell evaluation is shown in positive pole [4] table 2.
(cyclic test (assay method of durable back battery capacity and durable back power output))
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.After being charged to charging upper voltage limit 4.2V with 2C constant-current constant-voltage method, be discharged to final discharging voltage 3.0V, as a charge and discharge cycles, carry out this circulation with this repeatedly, until 500 circulations with the constant current of 2C.Battery after finishing for cyclic test, the current value with 0.2C under 25 ℃ environment carries out discharging and recharging of 3 circulations, with the 0.2C discharge capacity of the 3rd circulation as durable back battery capacity.In addition, the battery for after the cyclic test end carries out output test, as durable back power output.The result of cell evaluation is shown in positive pole [4] table 2.
Anodal [4] embodiment 2
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 1.The result of cell evaluation is shown in positive pole [4] table 2.
Anodal [4] embodiment 3
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 1.The result of cell evaluation is shown in positive pole [4] table 2.
Anodal [4] embodiment 4
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 1.The result of cell evaluation is shown in positive pole [4] table 2.
Anodal [4] comparative example 1
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [4] embodiment 1.The result of cell evaluation is shown in positive pole [4] table 2.
Anodal [4] table 2
[table 19]
Figure BDA0000087738240002331
Anodal [4] embodiment 5
Except using positive active material B as positive active material, process beyond the positive pole, implement equally with anodal [4] embodiment 1.The result of cell evaluation is shown in positive pole [4] table 3.
Anodal [4] embodiment 6
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 5.The result of cell evaluation is shown in positive pole [4] table 3.
Anodal [4] embodiment 7
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 5.The result of cell evaluation is shown in positive pole [4] table 3.
Anodal [4] embodiment 8
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 5.The result of cell evaluation is shown in positive pole [4] table 3.
Anodal [4] comparative example 2
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [4] embodiment 5.The result of cell evaluation is shown in positive pole [4] table 3.
Anodal [4] table 3
[table 20]
Figure BDA0000087738240002341
Anodal [4] embodiment 9
The positive active material that uses positive active material A and positive active material B fully to mix with 2: 1 mass ratio and obtain is processed positive pole as positive active material, and in addition, [4] embodiment 1 implements equally with positive pole.The BET specific area of the positive active material of this mixing is 1.8m 2/ g, average primary particle diameter are 0.2 μ m, median particle diameter d 50Be 4.9 μ m, tap density is 1.8g/cm 3The cell evaluation result is shown in positive pole [4] table 4.
Anodal [4] embodiment 10
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 9.The result of cell evaluation is shown in positive pole [4] table 4.
Anodal [4] embodiment 11
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 9.The result of cell evaluation is shown in positive pole [4] table 4.
Anodal [4] embodiment 12
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 9.The result of cell evaluation is shown in positive pole [4] table 4.
Anodal [4] comparative example 3
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [4] embodiment 9.The result of cell evaluation is shown in positive pole [4] table 4.
Anodal [4] table 4
[table 21]
Figure BDA0000087738240002351
Anodal [4] embodiment 13
Except using positive active material C as positive active material, process beyond the positive pole, implement equally with anodal [4] embodiment 1.The result of cell evaluation is shown in positive pole [4] table 5.
Anodal [4] embodiment 14
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 13.The result of cell evaluation is shown in positive pole [4] table 5.
Anodal [4] embodiment 15
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 13.The result of cell evaluation is shown in positive pole [4] table 5.
Anodal [4] embodiment 16
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 13.The result of cell evaluation is shown in positive pole [4] table 5.
Anodal [4] comparative example 4
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [4] embodiment 13.The result of cell evaluation is shown in positive pole [4] table 5.
Anodal [4] table 5
[table 22]
Figure BDA0000087738240002361
Anodal [4] embodiment 17
The positive active material that uses positive active material A and positive active material D fully to mix with 2: 1 mass ratio and obtain is as positive active material; Process positive pole; Roll into thickness 92 μ m with press; And use 30 should positive pole and 31 negative poles, in addition, implement equally with anodal [4] embodiment 1.(the positive electrode active material layer thickness of anodal one side)/(thickness of positive electrode collector) is 2.6, and anodal electrode area summation is 19.4 with the ratio of the long-pending summation of the case surface of battery.In addition, the BET specific area of the positive active material of this mixing is 1.1m 2/ g, average primary particle diameter are 0.6 μ m, median particle diameter d 50Be 7.3 μ m, tap density is 2.2g/cm 3The cell evaluation result is shown in positive pole [4] table 6.
Anodal [4] embodiment 18
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 17.The result of cell evaluation is shown in positive pole [4] table 6.
Anodal [4] embodiment 19
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 17.The result of cell evaluation is shown in positive pole [4] table 6.
Anodal [4] embodiment 20
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [4] embodiment 17.The result of cell evaluation is shown in positive pole [4] table 6.
Anodal [4] comparative example 5
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [4] embodiment 17.The result of cell evaluation is shown in positive pole [4] table 6.
Anodal [4] table 6
[table 23]
Figure BDA0000087738240002371
Can know that from the result of anodal [4] table 2～positive pole [4] table 6 in any positive pole, owing in nonaqueous electrolytic solution, all contain specific compound, the initial stage power output is improved.In addition, capability retention is improved, even after cyclic test, also can fully keep battery capacity and power output.
Anodal [5] [positive active material]
The kind and the rerum natura of the positive active material that uses in following embodiment and the comparative example are following.
Anodal [5] table 1
[table 24]
Figure BDA0000087738240002381
In anodal [5] table 1,,, carry out BET specific area, average primary particle diameter (measuring), median particle diameter d with SEM according to the method for above-mentioned record as the rerum natura of positive active material 50, tap density mensuration.
[positive active material A]
Positive active material A is through the synthetic lithium cobalt composite oxide of the method shown in following, uses composition formula LiCoO 2Expression.With Li: Co=1: 1 molar ratio weighing is as the LiOH of lithium raw material with as the Co (OH) of cobalt raw material 2, and process slurry to wherein adding pure water, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.2 μ m while stirring.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 9 μ m of particle diameter of lithium raw material, cobalt raw material.Under circulation of air, 880 ℃ to this granulation particles sintering 6 hours (warming and cooling rate is 5 ℃/minute).Behind the cool to room temperature, take out and pulverize,, obtain positive active material A through the sieve of mesh 45 μ m.
[positive active material B]
Positive active material B is through the synthetic lithium-transition metal composite oxide of following method, with composition formula Li 1.05Ni 0.80Co 0.2O 2Expression.With Ni: Co=80: 20 molar ratio weighing is as the NiO of nickel raw material, as the Co (OH) of cobalt raw material 2, and process slurry to wherein adding pure water, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.25 μ m while stirring.
Through spray dryer slurry is carried out spray drying, the particle diameter that is only comprised nickel raw material, cobalt raw material is about the roughly spherical granulation particle of 8 μ m.In the granulation particle that obtains, adding median particle diameter is the LiOH powder of 3 μ m, makes that the ratio of molal quantity and the total mole number of Ni and Co of Li is 1.05, mixes with high-speed mixer, obtains the granulation particle of nickel raw material, cobalt raw material and the mixed-powder of lithium raw material.This mixed-powder is pulverized down in 740 ℃ of following sintering (warming and cooling rate is 5 ℃/minute) 6 hours in that oxygen flow is logical then, through the sieve of mesh 45 μ m, obtains positive active material B.
[positive active material C]
Positive active material C is through the synthetic lithium-transition metal composite oxide of following method, with composition formula Li 1.05Ni 0.80Co 0.15Al 0.05O 2Expression.With Ni: Co: Al=80: 15: 5 molar ratio weighing is as the NiO of nickel raw material, as the Co (OH) of cobalt raw material 2And, process slurry to wherein adding pure water as the AlOOH of aluminum feedstock, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.25 μ m while stirring.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 10 μ m of particle diameter of nickel raw material, cobalt raw material, aluminum feedstock.In the granulation particle that obtains, add the LiOH powder of median particle diameter 3 μ m; Make that the molal quantity of Li is 1.05 with respect to the ratio of the total mole number of Ni, Co and Al; Mix with high-speed mixer, obtain the granulation particle of nickel raw material, cobalt raw material, aluminum feedstock and the mixed-powder of lithium raw material.This mixed-powder is pulverized down in 740 ℃ of following sintering (warming and cooling rate is 5 ℃/minute) 6 hours in that oxygen flow is logical then, through the sieve of mesh 45 μ m, obtains positive active material C.
[positive active material D]
Positive active material C be according to the method shown in following synthetic in the surface attachment of positive active material C sulphur compound and antimonial and the positive active material that forms.That is, 96.7 weight portion positive active material C are stirred in flowing grooves, simultaneously to the 1.3 weight portion lithium sulfate (Li that wherein spray 2SO 4H 2O) the aqueous solution becomes spray form.In the mixture that obtains, add 2.0 weight portion antimony trioxide (Sb 2O 3, the particle median particle diameter is 0.8 μ m), fully mix.This mixture is transferred in the alumina container, under air atmosphere,, obtained positive active material D in 680 ℃ of sintering 2 hours.
[positive active material E]
Positive active material E is through the synthetic lithium-transition metal composite oxide of following method, with composition formula LiMn 0.33Ni 0.33Co 0.33O 2Expression.With Mn: Ni: Co=1: 1: 1 molar ratio weighing is as the Mn of manganese raw material 3O 4, as the NiO of nickel raw material and as the Co (OH) of cobalt raw material 2, process slurry to wherein adding pure water, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.2 μ m while stirring.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 5 μ m of particle diameter of manganese raw material, nickel raw material, cobalt raw material.In the granulation particle that obtains, add the LiOH powder of median particle diameter 3 μ m; Make that the molal quantity of Li is 1.05 with respect to the ratio of the total mole number of Mn, Ni and Co; Mix with high-speed mixer, obtain the granulation particle of manganese raw material, nickel raw material, cobalt raw material and the mixed-powder of lithium raw material.This mixed-powder is pulverized down in 950 ℃ of following sintering (warming and cooling rate is 5 ℃/minute) 12 hours in that oxygen flow is logical then, through the sieve of mesh 45 μ m, obtains positive active material E.
[positive active material F]
Positive active material F is through the synthetic lithium-transition metal composite oxide of following method, with composition formula Li 1.04Mn 1.84Al 0.12O 4Expression.With Li: Mn: Al=1.04: 1.84: 0.12 molar ratio weighing is as the LiOH of lithium raw material, as the Mn of manganese raw material 2O 3With AlOOH as aluminum feedstock, process slurry to wherein adding pure water, use circulating medium-stirring wet-type ball mill that the solid constituent case of wet attrition in the slurry is become median particle diameter 0.5 μ m while stirring.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 10 μ m of particle diameter of lithium raw material, manganese raw material and aluminum feedstock.With the granulation particle that obtains under nitrogen circulation in 900 ℃ of following sintering (warming and cooling rate is 5 ℃/minute) 3 hours, then, circulated gases is transformed into air by nitrogen, again 900 ℃ of following sintering (cooling rate is 1 ℃/minute) 2 hours.Behind the cool to room temperature, take out and pulverize,, obtain positive active material F through the sieve of mesh 45 μ m.
Anodal [5] embodiment 1
" anodal making "
Positive active material A and negative electrode active material B are fully mixed with 1: 1 mass ratio, and it is anodal to use the positive active material that obtains to make.The BET specific area of this mixed positive active material is 1.2m 2/ g, average primary particle diameter are 0.8 μ m, median particle diameter d 50Be 6.5 μ m, tap density is 2.1g/cm 3
In N crassitude ketone solvent, mix the above-mentioned mixed positive active material A of 90 quality %, 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, using press to roll into thickness is 70 μ m, be cut into again have wide 100mm, the shape of the uncoated part of positive electrode active material layer that long 100mm is big or small and wide 30mm, process positive pole.The density of positive active material is 2.35g/cm 3, the value of (thickness of the positive electrode active material layer of one side)/(thickness of collector body) is 1.8.
" making of negative pole "
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose be 1 quality %) of 100 weight portions in as the sodium carboxymethylcellulose of thickener; 2 weight portions are as the aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) of the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of negative electrode active material layer that long 104mm is big or small and wide 30mm, as negative pole.
" making of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixed solvent of 3: 3: 4 (volume ratio) of ethylene carbonate (EC), dimethyl carbonate (DMC) and the methyl ethyl carbonate (EMC) of purifying, with the lithium hexafluoro phosphate (LiPF of the concentration dissolving intensive drying of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that contains 0.3 quality %.
" making of battery "
With 33 positive poles and 34 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and manufacture batteries.Anodal electrode area summation is 21.3 with the ratio of the long-pending summation of the case surface of battery.
" evaluation of battery "
(assay method of battery capacity)
To new battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.2V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.The 0.2C discharge capacity of the 5th circulation of this moment is as initial capacity.The result of cell evaluation is shown in positive pole [5] table 2.
(assay method of initial stage power output)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as power output (W).The result of cell evaluation is shown in positive pole [5] table 2.
(cyclic test (assay method of durable back battery capacity and durable back power output))
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.After being charged to charging upper voltage limit 4.2V with 2C constant-current constant-voltage method, be discharged to final discharging voltage 3.0V, as a charge and discharge cycles, carry out this circulation with this repeatedly, until 500 circulations with the constant current of 2C.Battery after finishing for cyclic test, the current value with 0.2C under 25 ℃ environment carries out discharging and recharging of 3 circulations, with the 0.2C discharge capacity of the 3rd circulation as durable back battery capacity.In addition, the battery for after the cyclic test end carries out output test, as durable back power output.The result of cell evaluation is shown in positive pole [5] table 2.
Anodal [5] embodiment 2
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 1.The result of cell evaluation is shown in positive pole [5] table 2.
Anodal [5] embodiment 3
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 1.The result of cell evaluation is shown in positive pole [5] table 2.
Anodal [5] embodiment 4
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 1.The result of cell evaluation is shown in positive pole [5] table 2.
Anodal [5] comparative example 1
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [5] embodiment 1.The result of cell evaluation is shown in positive pole [5] table 2.
Anodal [5] table 2
[table 25]
Figure BDA0000087738240002421
Anodal [5] embodiment 5
The positive active material that uses positive active material A and positive active material E fully to mix with 1: 1 mass ratio and obtain is as positive active material; Process positive pole; Roll into thickness 78 μ m with press; And use 32 should positive pole and 33 negative poles, in addition, implement equally with anodal [5] embodiment 1.(the positive electrode active material layer thickness of anodal one side)/(thickness of positive electrode collector) is 2.1, and anodal electrode area summation is 20.6 with the ratio of the long-pending summation of the case surface of battery.The BET specific area of the positive active material of this mixing is 1.2m 2/ g, average primary particle diameter are 0.8 μ m, median particle diameter d 50Be 5.7 μ m, tap density is 2.0g/cm 3The cell evaluation result is shown in positive pole [5] table 3.
Anodal [5] embodiment 6
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 5.The result of cell evaluation is shown in positive pole [5] table 3.
Anodal [5] embodiment 7
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 5.The result of cell evaluation is shown in positive pole [5] table 3.
Anodal [5] embodiment 8
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 5.The result of cell evaluation is shown in positive pole [5] table 3.
Anodal [5] comparative example 2
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [5] embodiment 5.The result of cell evaluation is shown in positive pole [5] table 3.
Anodal [5] table 3
[table 26]
Anodal [5] embodiment 9
The positive active material that uses positive active material A and positive active material F fully to mix with 1: 1 mass ratio and obtain is as positive active material; Process positive pole; Roll into thickness 91 μ m with press; And use 30 should positive pole and 31 negative poles, in addition, implement equally with anodal [5] embodiment 1.(the positive electrode active material layer thickness of anodal one side)/(thickness of positive electrode collector) is 2.5, and anodal electrode area summation is 19.4 with the ratio of the long-pending summation of the case surface of battery.The BET specific area of the positive active material of this mixing is 1.0m 2/ g, average primary particle diameter are 0.6 μ m, median particle diameter d 50Be 7.5 μ m, tap density is 2.2g/cm 3The cell evaluation result is shown in positive pole [5] table 4.
Anodal [5] embodiment 10
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 9.The result of cell evaluation is shown in positive pole [5] table 4.
Anodal [5] embodiment 11
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 9.The result of cell evaluation is shown in positive pole [5] table 4.
Anodal [5] embodiment 12
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 9.The result of cell evaluation is shown in positive pole [5] table 4.
Anodal [5] comparative example 3
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [5] embodiment 9.The result of cell evaluation is shown in positive pole [5] table 4.
Anodal [5] table 4
[table 27]
Figure BDA0000087738240002451
Anodal [5] embodiment 13
The positive active material that uses positive active material C and positive active material E fully to mix with 1: 1 mass ratio and obtain is as positive active material; Process positive pole; Roll into thickness 72 μ m with press; Use 33 should positive pole and 34 negative poles, in addition, implement equally with anodal [5] embodiment 1.The BET specific area of this mixed positive active material is 0.9m 2/ g, average primary particle diameter are 0.7 μ m, median particle diameter d 50Be 6.7 μ m, tap density is 2.0g/cm 3(the positive electrode active material layer thickness of anodal one side)/(thickness of positive electrode collector) is 1.9, and anodal electrode area summation is 21.3 with the ratio of the long-pending summation of the case surface of battery.Voltage range in solid measure is that the upper voltage limit of 3.0～4.1V, cyclic test is the 4.1V, likewise estimates battery with anodal [5] embodiment 1.The cell evaluation result is shown in positive pole [5] table 5.
Anodal [5] embodiment 14
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 13.The result of cell evaluation is shown in positive pole [5] table 5.
Anodal [5] embodiment 15
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 13.The result of cell evaluation is shown in positive pole [5] table 5.
Anodal [5] embodiment 16
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 13.The result of cell evaluation is shown in positive pole [5] table 5.
Anodal [5] comparative example 4
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [5] embodiment 13.The result of cell evaluation is shown in positive pole [5] table 5.
Anodal [5] table 5
[table 28]
Figure BDA0000087738240002461
Anodal [5] embodiment 17
The positive active material that uses positive active material C and positive active material F fully to mix with 1: 1 mass ratio and obtain is as positive active material; Process positive pole; Roll into thickness 78 μ m with press; Use 32 should positive pole and 33 negative poles, in addition, implement equally with anodal [5] embodiment 1.(the positive electrode active material layer thickness of anodal one side)/(thickness of positive electrode collector) is 2.1, and anodal electrode area summation is 20.6 with the ratio of the long-pending summation of the case surface of battery.The BET specific area of the positive active material of this mixing is 0.8m 2/ g, average primary particle diameter are 0.6 μ m, median particle diameter d 50Be 8.5 μ m, tap density is 2.2g/cm 3The cell evaluation result is shown in positive pole [5] table 6.
Anodal [5] embodiment 18
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 6.
Anodal [5] embodiment 19
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 6.
Anodal [5] embodiment 20
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 6.
Anodal [5] comparative example 5
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 6.
Anodal [5] table 6
[table 29]
Figure BDA0000087738240002471
Anodal [5] embodiment 21
The positive active material that uses positive active material D and positive active material E fully to mix with 1: 1 mass ratio and obtain is as positive active material; Process positive pole; Roll into thickness 72 μ m with press; Use 33 should positive pole and 34 negative poles, in addition, implement equally with anodal [5] embodiment 1.The BET specific area of this mixed positive active material is 0.9m 2/ g, average primary particle diameter are 0.7 μ m, median particle diameter d 50Be 6.7 μ m, tap density is 2.0g/cm 3(the positive electrode active material layer thickness of anodal one side)/(thickness of positive electrode collector) is 1.9, and anodal electrode area summation is 21.3 with the ratio of the long-pending summation of the case surface of battery.Voltage range in solid measure is that the upper voltage limit of 3.0～4.1V, cyclic test is the 4.1V, likewise estimates battery with anodal [5] embodiment 1.The cell evaluation result is shown in positive pole [5] table 7.
Anodal [5] embodiment 22
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 7.
Anodal [5] embodiment 23
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 7.
Anodal [5] embodiment 24
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 7.
Anodal [5] comparative example 6
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 7.
Anodal [5] table 7
[table 30]
Figure BDA0000087738240002481
Anodal [5] embodiment 25
The positive active material that uses positive active material E and positive active material F fully to mix with 1: 1 mass ratio and obtain is as positive active material; Process positive pole; Roll into thickness 86 μ m with press; Use 31 should positive pole and 32 negative poles, in addition, implement equally with anodal [5] embodiment 1.(the positive electrode active material layer thickness of anodal one side)/(thickness of positive electrode collector) is 2.4, and anodal electrode area summation is 20.0 with the ratio of the long-pending summation of the case surface of battery.The BET specific area of this mixed positive active material is 1.1m 2/ g, average primary particle diameter are 0.6 μ m, median particle diameter d 50Be 6.2 μ m, tap density is 2.0g/cm 3The cell evaluation result is shown in positive pole [5] table 8.
Anodal [5] embodiment 26
Make the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 8.
Anodal [5] embodiment 27
Make the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 8.
Anodal [5] embodiment 28
Make the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % replace hexamethyl cyclotrisiloxane, in addition, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 8.
Anodal [5] comparative example 7
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane, implement equally with anodal [5] embodiment 17.The result of cell evaluation is shown in positive pole [5] table 8.
Anodal [5] table 8
[table 31]
Figure BDA0000087738240002491
Can know from the result of anodal [5] table 2～positive pole [5] table 8, in any positive pole, owing in nonaqueous electrolytic solution, all contain specific compound; Therefore; Power output, capability retention are improved, even and after cyclic test, also can fully keep battery capacity and power output.
Negative pole [1] [making of negative electrode active material]
(making 1 of negative electrode active material)
In order to prevent to sneak into oversize grain in the commercially available native graphite powder as particle shape carbonaceous material, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative material that obtains like this as carbonaceous material (A).
(making 2 of negative electrode active material)
The petroleum-type heavy oil that in non-active gas, obtains during to the naphtha pyrolysis is implemented 1300 ℃ carbonization treatment, then, obtains carbonaceous material (B) through sinter being carried out hierarchical processing.In the hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times in order to prevent to sneak into oversize grain.
(making 3 of negative electrode active material)
The carbonaceous material (B) of the carbonaceous material (A) of 95 quality % and 5 quality % is evenly mixed, with mixture as 2 kinds of crystallinity carbonaceous material mixtures (C).
(making 4 of negative electrode active material)
The petroleum-type heavy oil that obtains when in carbonaceous material (A), mixing the naphtha pyrolysis; In non-active gas, implement 1300 ℃ carbonization treatment; Then; Obtain carbonaceous material (D) through sinter being carried out hierarchical processing, said composite carbonaceous material (D) is on carbonaceous material (A) particle surface, to have coated the composite carbonaceous material with different crystalline carbonaceous material.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times in order to prevent to sneak into oversize grain.Can confirm that from carbon yield the negative electrode active material powder that obtains is coated by the low-crystalline carbonaceous material that with respect to 95 weight portion graphite is 5 weight.
(making 5 of negative electrode active material)
The petroleum-type heavy oil that in the making 4 that reduces negative electrode active material, when the naphtha pyrolysis, obtains also mixes; According to carrying out with the making 4 same methods of negative electrode active material; Obtain composite carbonaceous material (E), it is coated by the low-crystalline carbonaceous material that with respect to 99 weight portion graphite is 1 weight.
(making 6 of negative electrode active material)
The petroleum-type heavy oil that in the making 4 that increases negative electrode active material, when the naphtha pyrolysis, obtains also mixes; According to carrying out with the making 4 same methods of negative electrode active material; Obtain composite carbonaceous material (F), it is coated by the low-crystalline carbonaceous material that with respect to 90 weight portion graphite is 10 weight.
(making 7 of negative electrode active material)
The petroleum-type heavy oil that in the making 4 that increases negative electrode active material, when the naphtha pyrolysis, obtains also mixes; According to carrying out with the making 4 same methods of negative electrode active material; Obtain composite carbonaceous material (G), it is coated by the low-crystalline carbonaceous material that with respect to 70 weight portion graphite is 30 weight.
(making 8 of negative electrode active material)
Except in the making 4 of negative electrode active material, in non-active gas, implementing 3000 ℃ graphitization processing; According to carrying out with the making 4 identical methods of negative electrode active material; Obtain composite carbonaceous material (I), it is coated by the low-crystalline carbonaceous material that with respect to 95 weight portion graphite is 5 weight.
(making 9 of negative electrode active material)
In carbonaceous material (A), mix phenol-formalin; In non-active gas, implement 1300 ℃ carbonization treatment; Then; Obtain composite carbonaceous material powder through sinter is carried out hierarchical processing, said composite carbonaceous material powder is on the graphite particle surface, to have coated the composite carbonaceous material powder with different crystalline carbonaceous material.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times, obtain composite carbonaceous material (J) in order to prevent to sneak into oversize grain.Can confirm that from carbon yield the negative electrode active material powder that obtains is coated by the low-crystalline carbonaceous material that with respect to 95 weight portion graphite is 5 weight.
(making 10 of negative electrode active material)
The composition that in reacting furnace, under 460 ℃, will be insoluble to quinoline is that the coal tar asphalt below the 0.05 quality % carries out heat treatment in 10 hours; Use pulverizer (the orient mill (オ リ エ Application ト ミ Le) that seishin enterprise-like corporation makes) that the block carbon metallic substance that obtains is pulverized; Re-using the atomizer turbine type of matsubo (the マ Star ボ one) manufactured (mill), to carry out micro mist broken, miniaturization to median particle diameter 17 μ m.This particle is packed in the container of made, in the electric furnace of box-shaped, under the nitrogen circulation, carry out heat treatment in 2 hours in 540 ℃.The cake mass that obtains is pulverized with Roughpulverizer (Jitian makes the roll crusher (ロ one Le ジ ヨ one Network ラ Star シ ヤ one) of manufacturing); It is broken to use the atomizer turbine type of the matsubo manufactured (mill) to carry out micro mist again; The powder that obtains is packed in the container; Under nitrogen atmosphere, with electric furnace 1300 ℃ of following sintering 1 hour.Then, the sinter that obtains is carried out hierarchical processing, obtain carbonaceous material (K) thus.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times in order to prevent to sneak into oversize grain.
(making 11 of negative electrode active material)
In carbonaceous material (K), mix phenol-formalin; In non-active gas, implement 1300 ℃ carbonization treatment; Then; Obtain composite carbonaceous material powder through sinter is carried out hierarchical processing, said composite carbonaceous material powder is on the graphite particle surface, to have coated the composite carbonaceous material powder with different crystalline carbonaceous material.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times, obtain composite carbonaceous material (L) in order to prevent to sneak into oversize grain.Can confirm that from carbon yield the negative electrode active material powder that obtains is coated by the low-crystalline carbonaceous material that with respect to 60 weight portion graphite is 40 weight.
(making 12 of negative electrode active material)
The petroleum-type heavy oil that obtains when in carbonaceous material (K), mixing the naphtha pyrolysis; In non-active gas, implement 1300 ℃ carbonization treatment; Then; Obtain composite carbonaceous material powder through sinter is carried out hierarchical processing, said composite carbonaceous material powder is on the graphite particle surface, to have coated the composite carbonaceous material powder with different crystalline carbonaceous material.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times, obtain composite carbonaceous material (M) in order to prevent to sneak into oversize grain.Can confirm that from carbon yield the negative electrode active material powder that obtains is coated by the low-crystalline carbonaceous material that with respect to 95 weight portion graphite is 5 weight.
(making 13 of negative electrode active material)
The composition that in reacting furnace, under 460 ℃, will be insoluble to quinoline is that the coal tar asphalt below the 0.05 quality % carries out heat treatment in 10 hours; Use pulverizer (the orient mill that senshin enterprise-like corporation makes) that the block carbon metallic substance that obtains is pulverized; Re-using the atomizer turbine type of the matsubo manufactured (mill), to carry out micro mist broken, miniaturization to median particle diameter 17 μ m.This particle is packed in the container of made, in the electric furnace of box-shaped, under the nitrogen circulation, carry out heat treatment in 2 hours in 540 ℃.The cake mass that obtains is pulverized with Roughpulverizer (Jitian makes the roll crusher of manufacturing); It is broken to use the atomizer turbine type of the matsubo manufactured (mill) to carry out micro mist again; The powder that obtains is packed in the container, under nitrogen atmosphere, with electric furnace 1000 ℃ of following sintering 1 hour.Then, the powder transfer behind the sintering in graphite crucible, down with 5 hour is carried out graphitization in 3000 ℃ with the stove of directly switching in the non-active gas atmosphere, obtain carbonaceous material (N).The petroleum-type heavy oil that obtains when in carbonaceous material (N), mixing the naphtha pyrolysis; In non-active gas, implement 900 ℃ carbonization treatment; Then; Obtain carbonaceous material (O) through sinter being carried out hierarchical processing, said composite carbonaceous material (O) has coated on the graphite particle surface to have different crystalline carbonaceous material and obtains.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times in order to prevent to sneak into oversize grain.Can confirm that from carbon yield the negative electrode active material powder that obtains is coated by the low-crystalline carbonaceous material that with respect to 95 weight portion graphite is 5 weight.
(making 14 of negative electrode active material)
Except using the flakey native graphite to replace the carbonaceous material (A) in the making 4 of negative electrode active material; According to carrying out with the making 4 identical methods of negative electrode active material; Obtain composite carbonaceous material (P), it is coated by the low-crystalline carbonaceous material that with respect to 95 weight portion graphite is 5 weight.
(making 15 of negative electrode active material)
The petroleum-type heavy oil that in the making 14 that reduces negative electrode active material, when the naphtha pyrolysis, obtains also mixes; According to carrying out with the making 4 same methods of negative electrode active material; Then; With the powder transfer that obtains in graphite crucible, with direct energising stove in the non-active gas atmosphere in 3000 ℃ down with carrying out graphitization in 5 hours.Then, obtain carbonaceous material (Q) through sinter being carried out hierarchical processing, said composite carbonaceous material (Q) has coated on the graphite particle surface to have different crystalline carbonaceous material and obtains.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times in order to prevent to sneak into oversize grain.Can confirm that from carbon yield the negative electrode active material powder that obtains is coated by the low-crystalline carbonaceous material that with respect to 99 weight portion graphite is 1 weight.
(making 16 of negative electrode active material)
Except using volume average particle size is that the native graphite of 48 μ m replaces the carbonaceous material (A) in the making 4 of negative electrode active material; According to carrying out with the making 4 identical methods of negative electrode active material; Obtain composite carbonaceous material (R), it is coated by the low-crystalline carbonaceous material that with respect to 95 weight portion graphite is 5 weight.
(making 17 of negative electrode active material)
Except using low residual of degree of purification to have the native graphite of 1% ash content to replace the carbonaceous material (A) in the making 4 of negative electrode active material; According to carrying out with the making 4 identical methods of negative electrode active material; Obtain composite carbonaceous material (S), it is coated by the low-crystalline carbonaceous material that with respect to 95 weight portion graphite is 5 weight.
The rerum natura of the negative electrode active material that obtains is shown in negative pole [1] table 1.The assay method of rerum natura is same as described above.
Negative pole [1] table 1
[table 32]
Figure BDA0000087738240002531
Negative pole [1] [making of battery]
" anodal making 1 "
The cobalt acid lithium (LiCoO that in N-crassitude ketone solvent, mixes 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of positive electrode active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of the positive active material of this moment is 2.35g/cm 3
" anodal making 2 "
Except the quality of the active material of each face coating be 2 times of making 1 of positive pole, likewise carry out the making of anode electrode with the making 1 of positive pole.
" anodal making 3 "
The LiNi that in N-crassitude ketone solvent, mixes 90 quality % as positive active material 0.80Co 0.15Al 0.05O 2, 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 65 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of positive electrode active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of the positive active material of this moment is 2.35g/cm 3
" making 1 of negative pole "
In 98 weight portion negative electrode active materials, add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the rolled copper foil two sides of thickness 10 μ m; And it is dry; Roll into thickness 75 μ m with press, be cut into again have wide 104mm, the shape of the uncoated part of the negative electrode active material layer of long 104mm size and wide 30mm, as negative pole.The negative electrode active material density of this moment is 1.35g/cm 3
" making 2 of negative pole "
Except the quality of the active material of each face coating is in the making 1 of negative pole 2 times of use amount, likewise carry out the making of negative electrode with the making 1 of negative pole.
" making 3 of negative pole "
Except the density of the active material of a side in the making 1 that makes negative pole is 1.70g/cm 3In addition, likewise carry out the making of negative electrode with the making 1 of negative pole.
" making 4 of negative pole "
In 95 weight portion negative electrode active materials, add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 8 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, rolls into thickness 75 μ m with press, be cut into again have wide 104mm, the shape of the uncoated part of negative electrode active material layer that long 104mm is big or small and wide 30mm, as negative pole.The active material density of this moment is 1.35g/cm 3
" making 1 of electrolyte "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the difluorophosphoric acid lithium salts (LiPO that also contains 0.3 quality % 2F 2).
" making 2 of electrolyte "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the methanesulfonic acid trimethyl silyl ester that also contains 0.3 quality %.
" making 3 of electrolyte "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that also contains 0.3 quality %.
" making 4 of electrolyte "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).
" making 1 of battery "
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.The specified discharge capacity of this battery is about 6 ampere-hours (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms (m Ω).
" making 2 of battery "
With 16 positive poles and 17 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.The specified discharge capacity of this battery is about 6 ampere-hours (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 7 milliohms (m Ω).
Negative pole [1] embodiment 1
The electrolyte of making in the positive pole of making in the negative pole that use is processed as two kinds of crystallinity carbonaceous material mixtures (C) with the negative electrode active material of " making 1 of negative pole " item, " anodal making 1 " item and " making 1 of electrolyte " item is through the method manufacture batteries in " making 1 of battery " item.Method and said determination method through described in following " evaluation of battery " item are measured this battery.
Negative pole [1] embodiment 2
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (D) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 3
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (E) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 4
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (F) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 5
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (G) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 6
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (J) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 7
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (I) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 8
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (M) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 9
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (R) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 10
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (L) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 11
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (S) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 12
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (O) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 13
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (P) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 14
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the composite carbonaceous material (Q) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 15
The electrolyte of making in the positive pole of making in the negative pole that use is processed as composite carbonaceous material (D) with the negative electrode active material of " making 2 of negative pole " item, " anodal making 2 " item and " making 1 of electrolyte " item is through the method manufacture batteries in " making 2 of battery " item.In addition, likewise carry out the evaluation of battery with negative pole [1] embodiment 1.
Negative pole [1] embodiment 16
The electrolyte of making in the positive pole of making in the negative pole that use is processed as composite carbonaceous material (D) with the negative electrode active material of " making 3 of negative pole " item, " anodal making 1 " item and " making 1 of electrolyte " item is through the method manufacture batteries in " making 1 of battery " item.In addition, likewise carry out the evaluation of battery with negative pole [1] embodiment 1.
Negative pole [1] embodiment 17
The electrolyte of making in the positive pole of making in the negative pole that use is processed as composite carbonaceous material (D) with the negative electrode active material of " making 4 of negative pole " item, " anodal making 1 " item and " making 1 of electrolyte " item is through the method manufacture batteries in " making 1 of battery " item.In addition, likewise carry out the evaluation of battery with negative pole [1] embodiment 1.
The evaluation result of negative pole [1] embodiment 1～negative pole [1] embodiment 17 is shown in negative pole [1] table 2.
Negative pole [1] embodiment 18～34
Except the electrolyte with negative pole [1] embodiment 1～17 is replaced with the electrolyte of " making 2 of an electrolyte " making, carry out the evaluation of battery with same method.The evaluation result of negative pole [1] embodiment 18～negative pole [1] embodiment 34 is shown in negative pole [1] table 3.
Negative pole [1] embodiment 35～51
Except the electrolyte with negative pole [1] embodiment 1～17 is replaced with the electrolyte of " making 3 of an electrolyte " making, carry out the evaluation of battery with same method.The evaluation result of negative pole [1] embodiment 35～negative pole [1] embodiment 51 is shown in negative pole [1] table 4.
Negative pole [1] comparative example 1
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (A) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] comparative example 2
Except the electrolyte that electrolyte use " making 4 of the electrolyte " item of negative pole [1] comparative example 1 is made, manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] comparative example 3
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (B) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] comparative example 4
Except the electrolyte of negative pole [1] comparative example 3 uses " making 4 of electrolyte " the electrolyte of making, with negative pole [1] comparative example 3 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] comparative example 5
Except the electrolyte of negative pole [1] embodiment 1 uses " making 4 of electrolyte " the electrolyte of making, with negative pole [1] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] comparative example 6
Except the electrolyte that electrolyte use " making 4 of the electrolyte " item of negative pole [1] embodiment 2 is made, manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] comparative example 7
Except the negative electrode active material of negative pole [1] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (K) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] comparative example 8
Except the electrolyte that electrolyte use " making 4 of the electrolyte " item of negative pole [1] comparative example 7 is made, manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] comparative example 9～11
Except the electrolyte with negative pole [1] comparative example 1,3,7 is replaced with the electrolyte of " making 2 of an electrolyte " making, carry out the evaluation of battery with same method.
Negative pole [1] comparative example 12～14
Except the electrolyte with negative pole [1] comparative example 1,3,7 is replaced with the electrolyte of " making 3 of an electrolyte " making, carry out the evaluation of battery with same method.
The evaluation result of negative pole [1] comparative example 1～negative pole [1] comparative example 14 is shown in negative pole [1] table 5.
Negative pole [1] embodiment 52
The electrolyte of making in anodal and " making 1 of electrolyte " item of making in the negative pole that use is processed as composite carbonaceous material (D) with the negative electrode active material of " making 1 of negative pole " item, " anodal making 1 " item; Through the method manufacture batteries in " making 1 of battery " item, carry out the cell evaluation of record in " evaluation of battery " item.
Negative pole [1] embodiment 53
Except electrolyte uses " making 2 of electrolyte " the electrolyte of making, with embodiment 52 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] embodiment 54
Except electrolyte uses " making 3 of electrolyte " the electrolyte of making, with embodiment 52 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [1] comparative example 15
Except electrolyte uses " making 4 of electrolyte " the electrolyte of making, with embodiment 52 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
The evaluation result of embodiment 52～54 and comparative example 15 is shown in negative pole [1] table 6.
Negative pole [1] " evaluation of battery "
(solid measure)
To battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.2V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.With the 0.2C discharge capacity of the 5th circulation of this moment as initial capacity.Output test shown in below carrying out then.
(output test)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as power output (W).
(cyclic test)
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.After being charged to charging upper voltage limit 4.2V with 2C constant-current constant-voltage method, be discharged to final discharging voltage 3.0V, as a charge and discharge cycles, carry out this circulation with this repeatedly, until 500 circulations with the constant current of 2C.Battery after finishing for cyclic test carries out discharging and recharging of 3 circulations under 25 ℃ environment, with the 0.2C discharge capacity of the 3rd circulation as circulation back capacity.Obtain the circulation conservation rate by capacity after the circulation of measuring after initial capacity of measuring before the circulation and the cyclic test end through following calculating formula.
Circulation conservation rate (%)=100 * circulation back capacity/initial capacity
Battery after the cyclic test end is carried out output test of (output test) record.At this moment, the power output of using preceding power output of cyclic test and cyclic test to finish to implement the back is calculated the power output conservation rate shown in the following formula.
Power output conservation rate (%)=100 * cyclic test finishes the preceding power output of back power output/circulation
Impedance Rct and double-deck capacity C dl in negative pole [1] table 2 are to one of contributive parameter of power output, and the value of impedance Rct is more little, and perhaps the value of double-deck capacity C dl is big more, and then power output has the tendency of improvement more.In addition, " impedance Rct " and " double-deck capacity C dl " obtains through the method put down in writing of part of explanation impedance.
Negative pole [1] table 2
[table 33]
In negative pole [1] table 2, electrolyte contains the difluorophosphoric acid lithium salts (LiPO that makes in 0.3 quality % " making 1 of electrolyte " 2F 2).
Negative pole [1] table 3
[table 34]
Figure BDA0000087738240002621
In negative pole [1] table 3, electrolyte contains the methanesulfonic acid trimethyl silyl ester of making in 0.3 quality % " making 2 of electrolyte ".
Negative pole [1] table 4
[table 35]
Figure BDA0000087738240002631
In negative pole [1] table 4, electrolyte contains the hexamethyl cyclotrisiloxane of making in 0.3 quality % " making 3 of electrolyte ".
Negative pole [1] table 5
[table 36]
Figure BDA0000087738240002641
Negative pole [1] table 6
Table [36]
Result by negative pole [1] table 2～6 can know; Situation through containing difluorophosphoric acid lithium salts, methanesulfonic acid trimethyl silyl ester, hexamethyl cyclotrisiloxane makes up with the situation that makes negative electrode active material contain the carbonaceous material that crystallinity is different more than 2 kinds, can make the power output conservation rate after the circulation obtain tremendous raising.
Negative pole [2] [making of negative electrode active material]
(making 1 of negative electrode active material)
The composition that in reacting furnace, under 460 ℃, will be insoluble to quinoline is that the coal tar asphalt below the 0.05 quality % carries out heat treatment in 10 hours; Use pulverizer (the orient mill that seishin enterprise-like corporation makes) that the block carbon metallic substance that obtains is pulverized; Re-using the atomizer turbine type of the matsubo manufactured (mill), to carry out micro mist broken, miniaturization to median particle diameter 18 μ m.This particle is encased in the container of made, in the electric furnace of box-shaped, the nitrogen circulation is carried out heat treatment in 2 hours in 540 ℃ down.With Roughpulverizer (Jitian makes the roll crusher of manufacturing) cake mass that obtains is pulverized; It is broken to use the atomizer turbine type of the matsubo manufactured (mill) to carry out micro mist again; The powder that obtains is packed in the container, under nitrogen atmosphere, under 1000 ℃, fired 1 hour with electric furnace.Then, the sinter that obtains is carried out hierarchical processing, obtain amorphous carbonaceous (A) thus.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times in order to prevent to sneak into oversize grain.
(making 2 of negative electrode active material)
In reacting furnace, be that coal tar asphalt below the 0.05 quality % carries out heat treatment in 10 hours, the cake mass that obtains is packed in the container, under nitrogen atmosphere, under 1000 ℃, carry out heat treatment in 2 hours with the box-shaped electric furnace in 460 ℃ of compositions that will be insoluble to down quinoline.Then, the sinter that obtains is carried out hierarchical processing, obtain amorphous carbonaceous (A) thus.The amorphous block material that uses Roughpulverizer (Jitian makes the roll crusher of manufacturing) to obtain is pulverized, and re-using atomizer (the turbine type mill of matsubo manufactured), to carry out micro mist broken, obtains amorphous powder.In order to sneak into oversize grain in the powder that prevents to obtain, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as amorphous carbon metallic substance (B).
(making 3 of negative electrode active material)
Transfer to the amorphous block material that obtains in (making 2 of negative electrode active material) in the graphite crucible again; Use directly energising stove, under the non-active gas atmosphere, 2200 ℃ of following heat treatments 5 hours; With Roughpulverizer (Jitian makes the roll crusher of manufacturing) cake mass that obtains is pulverized; Re-using the atomizer turbine type of the matsubo manufactured (mill), to carry out micro mist broken, in order to sneak into oversize grain in the powder that prevents to obtain, uses ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as amorphous carbon metallic substance (C).
(making 4 of negative electrode active material)
Transfer in the graphite crucible again with obtaining amorphous block material in (making 2 of negative electrode active material); Use directly energising stove, under the non-active gas atmosphere, under 3000 ℃, carry out 5 hours graphitizations; With Roughpulverizer (Jitian makes the roll crusher of manufacturing) cake mass that obtains is pulverized; Re-using the atomizer turbine type of the matsubo manufactured (mill), to carry out micro mist broken, in order to sneak into oversize grain in the powder that prevents to obtain, uses ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as amorphous carbon metallic substance (D).
(making 5 of negative electrode active material)
In order to prevent to sneak into oversize grain in the commercially available flakey native graphite powder, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as amorphous carbon metallic substance (E).
The negative electrode active material that obtains in the making 1～5 through said method anticathode active material is measured rerum natura, shape etc.The result is shown in negative pole [2] table 1.
Negative pole [2] table 1
[table 37]
Figure BDA0000087738240002661
Negative pole [2] [making of battery]
" anodal making 1 "
The cobalt acid lithium (LiCoO that in N-crassitude ketone solvent, mixes 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of the positive active material of this moment is 2.35g/cm 3
" making 1 of negative pole "
In 98 weight portion negative electrode active materials, add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the rolled copper foil two sides of thickness 10 μ m, and dry, rolls into thickness 75 μ m with press, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.The negative electrode active material density of this moment is 1.35g/cm 3
" making 1 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the difluorophosphoric acid lithium salts (LiPO that also contains 0.3 quality % 2F 2).
" making 2 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the methanesulfonic acid trimethyl silyl ester that also contains 0.3 quality %.
" making 3 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that also contains 0.3 quality %.
" making 4 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).
" making 1 of battery "
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.The specified discharge capacity of this battery is about 6 ampere-hours (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms (m Ω).Anodal electrode area summation is 20.6 with respect to the ratio of battery case surface area summation.
Negative pole [2] embodiment 1
The negative pole that use is processed as amorphous carbonaceous (A) with the negative electrode active material of " making 1 of negative pole " item; The electrolyte of making in anodal and " making 1 of electrolyte " item of making in " anodal making 1 " item is through the method manufacture batteries in " making 1 of battery " item.Method through described in following " evaluation of battery " item is carried out cell evaluation to this battery.The result is shown in negative pole [2] table 2.
Negative pole [2] embodiment 2
Except the negative electrode active material of negative pole [2] embodiment 1 " making 1 of negative pole " uses the amorphous carbonaceous (B) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [2] table 2.
Negative pole [2] embodiment 3
Except the negative electrode active material of negative pole [2] embodiment 1 " making 1 of negative pole " uses the amorphous carbonaceous (C) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [2] table 2.
Negative pole [2] embodiment 4～6
Except the nonaqueous electrolytic solution with negative pole [2] embodiment 1～2 changes the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [2] table 2.
Negative pole [2] embodiment 7～9
Except the nonaqueous electrolytic solution with negative pole [2] embodiment 1～3 changes the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [2] table 2.
Negative pole [2] comparative example 1～3
Except the nonaqueous electrolytic solution with negative pole [2] comparative example 1～3 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [2] table 2.
Negative pole [2] comparative example 4
Except the negative electrode active material of negative pole [2] embodiment 1 " making 1 of negative pole " uses the graphite matter carbonaceous (D) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [2] table 2.
Negative pole [2] comparative example 5
Except the negative electrode active material of negative pole [2] embodiment 1 " making 1 of negative pole " uses the graphite matter carbonaceous material (E) manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [2] table 2.
Negative pole [2] comparative example 6～7
Except the nonaqueous electrolytic solution with negative pole [2] comparative example 4～5 changes the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [2] table 2.
Negative pole [2] comparative example 8～9
Except the nonaqueous electrolytic solution with negative pole [2] comparative example 4～5 changes the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [2] table 2.
Negative pole [2] comparative example 10～11
Except the nonaqueous electrolytic solution with negative pole [2] comparative example 4～5 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [2] table 2.
Negative pole [2] " evaluation of battery "
(solid measure)
To the new battery without charge and discharge cycles, the initial stage of under 25 ℃, the voltage range of 4.1V～3.0V, carrying out 5 circulations discharges and recharges (voltage range 4.1V～3.0V).0.2 (as 1C, said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate) with the current value of 1 hour discharge rated capacity, down with) C discharge capacity of the 5th circulation of this moment is as initial capacity.
(short time high current density charge-discharge characteristic test)
Under 25 ℃ of room temperature environments, carry out charging in 150 minutes to having carried out the battery after the solid measure with the constant current of 0.2C.Voltage with this moment is the center, all switches on about 10 seconds to charging direction, course of discharge with the high load capacity electric current of 10C, comprises the test of intermittent time in an interior circulation in 35 seconds continuously repeatedly.Take out battery in moment of the 100,000 circulation, with the current discharge of 0.2C to 3V, through carrying out 1 circulation, as circulation back capacity with (solid measure) same method.And short time high current density charge-discharge characteristic passes through computes.
[short time high current density charge-discharge characteristic]=100 * [circulation back capacity]/[initial capacity]
Negative pole [2] table 2
[table 38]
Result by negative pole [2] table 2 can know; Through containing difluorophosphoric acid lithium salts, methanesulfonic acid trimethyl silyl ester, hexamethyl cyclotrisiloxane; And the interplanar distance (d002) that contains (002) face that wide-angle x-ray diffraction measures is 0.337 or more, Lc be the following and Raman R value of 80nm be amorphous carbonaceous more than 0.2 as negative electrode active material, can make short time high current density charge-discharge characteristic be able to improve tremendously.
Negative pole [3] [making of negative electrode active material]
(making 1 of negative electrode active material)
In order to prevent to sneak into oversize grain, use the Li of ASTM400 purpose sieve with commercially available volume average particle size 23 μ m 1.33Ti 1.66O 4Sieve repeatedly 5 times, obtain lithium-titanium composite oxide (A).
(making 2 of negative electrode active material)
In order to prevent to sneak into oversize grain, use the Li of ASTM400 purpose sieve with commercially available volume average particle size 1.0 μ m 1.33Ti 1.66O 4Sieve repeatedly 5 times, obtain lithium-titanium composite oxide (B).
(making 3 of negative electrode active material)
In order to prevent to sneak into oversize grain, use the Li of ASTM400 purpose sieve with commercially available volume average particle size 0.1 μ m 1.33Ti 1.66O 4Sieve repeatedly 5 times, obtain lithium-titanium composite oxide (C).
(making 4 of negative electrode active material)
In order to prevent to sneak into oversize grain in the commercially available flakey native graphite powder, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as graphite matter carbonaceous (D).
Conclusions such as the composition of negative electrode active material, structure, shape, rerum natura are shown in negative pole [3] table 1.
Negative pole [3] table 1
[table 39]
Negative pole [3] [making of battery]
" anodal making 1 "
The cobalt acid lithium (LiCoO that in N-crassitude ketone solvent, mixes 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of the active material of the positive pole of this moment is 2.35g/cm 3
" making 1 of negative pole "
In N-crassitude ketone solvent, mix 90 quality % negative electrode active materials, 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the one side of the rolled copper foil of thickness 10 μ m, and dry, rolls into thickness 90 μ m with press, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.
" making 1 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the difluorophosphoric acid lithium salts (LiPO that also contains 0.3 quality % 2F 2).
" making 2 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the methanesulfonic acid trimethyl silyl ester that also contains 0.3 quality %.
" making 3 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that also contains 0.3 quality %.
" making 4 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).
(making 1 of battery)
Negative pole is become 12.5mm φ with anodal punching; After carrying out vacuumize under 110 ℃; Transfer in the gloves work box; Under the argon atmosphere, positive pole is clipped punching with negative pole and become the polyethylene separator of 14mm φ opposed, and add the nonaqueous electrolytic solution of putting down in writing in the making item of nonaqueous electrolytic solution, make 2032 type coin batteries (lithium secondary battery).
Negative pole [3] embodiment 1
Use the electrolyte of making in anodal and " making 1 of nonaqueous electrolytic solution " made in the negative pole that the negative electrode active material of " making 1 of negative pole " makes as lithium-titanium composite oxide (A), " anodal making 1 ", through the method manufacture batteries in " making 1 of battery " item.This battery is carried out the cell evaluation described in following " evaluation of battery " item.The result is shown in negative pole [3] table 2.
Negative pole [3] embodiment 2
Except the negative electrode active material of negative pole [3] embodiment 1 " making 1 of negative pole " uses the lithium-titanium composite oxide (B), with negative pole [3] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [3] table 2.
Negative pole [3] embodiment 3
Except the negative electrode active material of negative pole [3] embodiment 1 " making 1 of negative pole " uses the lithium-titanium composite oxide (C), with negative pole [3] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [3] table 2.
Negative pole [3] embodiment 4～6
Except the nonaqueous electrolytic solution with negative pole [3] embodiment 1～3 changes the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [3] table 2.
Negative pole [3] embodiment 7～9
Except the nonaqueous electrolytic solution with negative pole [3] embodiment 1～3 changes the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [3] table 2.
Negative pole [3] comparative example 1～3
Except the nonaqueous electrolytic solution with negative pole [3] embodiment 1～3 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [3] table 2.
Negative pole [3] comparative example 4
Except the negative electrode active material of negative pole [3] embodiment 1 " making 1 of negative pole " uses the graphite matter carbonaceous (D), with negative pole [3] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [3] table 2.
Negative pole [3] comparative example 5
Except the nonaqueous electrolytic solution with negative pole [3] comparative example 4 changes the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [3] table 2.
Negative pole [3] comparative example 6
Except the nonaqueous electrolytic solution with negative pole [3] comparative example 4 changes the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [3] table 2.
Negative pole [3] comparative example 7
Except the nonaqueous electrolytic solution with negative pole [3] comparative example 4 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " item into, the manufacture batteries that uses the same method respectively, and estimate.The result is shown in negative pole [3] table 2.
Negative pole [3] " evaluation of battery "
(mensuration of capacity)
To new battery without charge and discharge cycles, be that 175mAh/g, graphite matter carbonaceous are that 350mAh/g converts with the lithium-titanium composite oxide, calculate battery capacity by the active matter quality that is present on the Copper Foil.And; With this battery capacity is benchmark under 25 ℃, the voltage range of 2.7V～1.9V; With 0.2C (with 1 hour the discharge rated capacity current value as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage that lithium-titanium composite oxide is carried out 5 circulations discharges and recharges.Likewise under 25 ℃, the voltage range of 4.1V～3.0V, the graphite matter carbonaceous initial stage of carrying out is discharged and recharged.With the 0.2C discharge capacity of the 5th circulation of this moment as initial capacity.
(mensuration of output resistance)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, under-30 ℃ environment, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.As output resistance (Ω), its result is shown in negative pole [3] table 2 with the slope of current-voltage straight line.
Negative pole [3] table 2
[table 40]
Figure BDA0000087738240002751
In negative pole [3] table 2, " output resistance slip " is to compare with the output resistance of the corresponding battery that does not contain specific compound and the slip (%) of the output resistance that obtains.
Result by negative pole [3] table 2 can know; Contain difluorophosphoric acid lithium salts, methanesulfonic acid trimethyl silyl ester, hexamethyl cyclotrisiloxane through use; And contain comprise can occlusion, emit the negative electrode active material of metal oxide of the titanium of lithium, can reduce output resistance tremendously.
Negative pole [4] [making of negative electrode active material]
(making 1 of negative electrode active material)
Use spheroidization processing unit (nara machinery is made the hybrid system of institute's manufactured); With rotating speed 6500rpm the flakey native graphite (ash content 0.05 weight %) of the about 150 μ m of the median particle diameter of high-purity processing being carried out 5 minutes spheroidizations handles; Re-use wind-force formula grader (OMC-100 that seishin enterprise-like corporation makes) and remove 45 weight % micro mists, obtain spheroidization native graphite (C).
(making 2 of negative electrode active material)
The powder of the spheroidization native graphite (C) after the above-mentioned classification is installed in the graphite crucible, use directly switch on stove under inactive atmosphere in 3000 ℃ of heat treatments 5 hours, obtain carbonaceous material (D).
(making 3 of negative electrode active material)
Except the heat treatment temperature in (making 2 of negative electrode active material) is set at 2000 ℃, likewise obtain carbonaceous material (E).
(making 4 of negative electrode active material)
Except the heat treatment temperature in (making 2 of negative electrode active material) is set at 1600 ℃, likewise obtain carbonaceous material (F).
(making 5 of negative electrode active material)
Except the heat treatment temperature in (making 2 of negative electrode active material) is set at 1200 ℃, likewise obtain carbonaceous material (G).
(making 5 of negative electrode active material)
Median particle diameter 17 μ m, tap density 0.5g/cm with the high-purity processing 3, BET specific area 6m 2The flakey native graphite of/g (ash content 0.1 weight %) is directly likewise heat-treated with (making 2 of negative electrode active material) and is not carried out spheroidization and handle, and obtains heat treatment native graphite (H).
(making 6 of negative electrode active material)
Median particle diameter 20 μ m, tap density 0.75g/cm with the high-purity processing 3, BET specific area 3m 2The native graphite of/g (ash content 0.5 weight %) is directly likewise heat-treated with (making 2 of negative electrode active material) and is not carried out spheroidization and handle, and obtains carbonaceous material (I).
According to above-mentioned method, the shape and the rerum natura of the spheroidization native graphite (C) that mensuration is made, carbonaceous material (D), carbonaceous material (E), carbonaceous material (F), carbonaceous material (G), heat treatment native graphite (H), carbonaceous material (I).The result is shown in negative pole [4] table 1.
Negative pole [4] table 1
Figure BDA0000087738240002771
Negative pole [4] [making of battery]
" anodal making 1 "
The cobalt acid lithium (LiCoO that in N-crassitude ketone solvent, mixes 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of the active material of the positive pole of this moment is 2.35g/cm 3
" making 1 of negative pole "
In 98 weight portion negative electrode active materials, add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the rolled copper foil two sides of thickness 10 μ m, and dry, rolls into thickness 75 μ m with press, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.The density of the active material of the negative pole of this moment is 1.35g/cm 3
" making 1 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the difluorophosphoric acid lithium salts (LiPO that also contains 0.3 quality % 2F 2).
" making 2 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the methanesulfonic acid trimethyl silyl ester that also contains 0.3 quality %.
" making 3 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that also contains 0.3 quality %.
" making 4 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).
(making 1 of battery)
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.The specified discharge capacity of this battery is about 6 ampere-hours (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms (m Ω).Anodal electrode area summation is 20.6 with respect to the ratio of battery case surface area summation.
Negative pole [4] embodiment 1
Use the nonaqueous electrolytic solution of making in anodal and " making 1 of nonaqueous electrolytic solution " made in the negative pole that the negative electrode active material of " making 1 of negative pole " processes as carbonaceous material (D), " anodal making 1 ", through the method manufacture batteries in " making 1 of battery ".Method and said determination method through described in following " evaluation of battery " item are measured this battery.The result is shown in negative pole [4] table 2.
Negative pole [4] embodiment 2
Except the negative electrode active material of negative pole [4] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (E), with negative pole [4] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [4] table 2.
Negative pole [4] embodiment 3
Except the negative electrode active material of negative pole [4] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (F), with negative pole [4] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [4] table 2.
Negative pole [4] embodiment 4
Except the negative electrode active material of negative pole [4] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (G), with negative pole [4] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [4] table 2.
Negative pole [4] embodiment 5
Except the negative electrode active material of negative pole [4] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (I), with negative pole [4] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [4] table 2.
Negative pole [4] embodiment 6～10
Except the nonaqueous electrolytic solution with negative pole [4] embodiment 1～5 changes the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " item respectively into, the manufacture batteries that uses the same method, and estimate.The result is shown in table 2 (negative pole [4] table 2).
Negative pole [4] embodiment 11～15
Except the nonaqueous electrolytic solution with negative pole [4] embodiment 1～5 changes the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " item respectively into, the manufacture batteries that uses the same method, and estimate.The result is shown in negative pole [4] table 2.
Negative pole [4] comparative example 1
Except the negative electrode active material of negative pole [4] embodiment 1 " making 1 of negative pole " uses the spheroidization native graphite (C), with negative pole [4] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [4] table 2.
Negative pole [4] comparative example 2
Except the nonaqueous electrolytic solution of negative pole [4] comparative example 1 uses the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution ", with negative pole [4] comparative example 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [4] table 2.
Negative pole [4] comparative example 3
Except the negative electrode active material of negative pole [4] embodiment 1 " making 1 of negative pole " uses the heat treatment native graphite (H), with negative pole [4] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [4] table 2.
Negative pole [4] comparative example 4
Except the nonaqueous electrolytic solution of negative pole [4] comparative example 3 uses the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution ", with negative pole [4] comparative example 3 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [4] table 2.
Negative pole [4] comparative example 5
Except the nonaqueous electrolytic solution of negative pole [4] embodiment 5 uses the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution ", with negative pole [4] embodiment 5 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [4] table 2.
Negative pole [4] comparative example 6
Except the nonaqueous electrolytic solution of negative pole [4] embodiment 1 uses the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution ", with negative pole [4] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [4] table 2.
Negative pole [4] comparative example 7,8
Except the nonaqueous electrolytic solution with negative pole [4] comparative example 1,3 changed the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " item into, difference is manufacture batteries after the same method, and estimates.The result is shown in negative pole [4] table 2.
Negative pole [4] comparative example 9,10
Except the nonaqueous electrolytic solution with negative pole [4] comparative example 1,3 changed the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " item into, difference is manufacture batteries after the same method, and estimates.The result is shown in negative pole [4] table 2.
Negative pole [4] table 2
Figure BDA0000087738240002821
Negative pole [4] " evaluation of battery "
(solid measure)
To battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.2V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.With the 0.2C discharge capacity of the 5th circulation of this moment as initial capacity.
(preserving test)
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, preserve.20% of the initial capacity of measuring when reaching solid measure with the constant-current constant-voltage method capacity of charging to of 0.2C, and reach charging upper voltage limit 4.2V, under 60 ℃ hot environment, preserved for 1 week then.Battery after will preserving under 25 ℃ of environment is discharged to 3V with 0.2C, further under the condition identical with (solid measure), carries out discharging and recharging of 3 circulations, and the 0.2C discharge capacity of the 3rd circulation is preserved the back capacity as low depth of charge.Preserve the back capacity by the low depth of charge of measuring after preserving the initial capacity of measuring before the test and preserving off-test and obtain the circulation conservation rate according to following calculating formula.
Low depth of charge is preserved back recovery rate (%)=100 * low depth of charge and is preserved back capacity/initial capacity
Can know by The above results; Through containing difluorophosphoric acid lithium salts, methanesulfonic acid trimethyl silyl ester, hexamethyl cyclotrisiloxane; And process that the circularity that contains negative electrode active material is more than 0.85, negative pole that surface functionalities group amount O/C value is 0～0.01 carbonaceous material, low depth of charge after the preservation test of low depth of charge is preserved after recovery rate obtain tremendous raising.
Negative pole [5] [making of negative material]
[making 1 of negative material]
With the quinoline non-soluble composition be coal tar asphalt below the 0.05 quality % in reacting furnace in 460 ℃ of heat treatments 10 hours, obtain the heat treatment graphite crystallization precursor of the bulk with meltbility of 385 ℃ of softening points.The heat treatment graphite crystallization precursor of the bulk that will obtain with middle pulverizer (seishin enterprise-like corporation make orient mill) is pulverized; Re-using the atomizer turbine type of the matsubo manufactured (mill), to carry out micro mist broken, obtains the graphite crystallization precursor powder (E) of the miniaturization of median particle diameter 17 μ m.
In the graphite crystallization precursor powder (E) of above-mentioned miniaturization, be that the mixed median particle diameter of 50 quality % is that 17 μ m, draw ratio are 1.4, tap density is 1.0g/cm with total weight with respect to miniaturization graphite crystallization precursor powder and native graphite 3, the BET specific area is 6.5g/cm 3, circularity is 0.92 native graphite, obtains mixed-powder.
The mixed-powder of this heat treatment graphite crystallization precursor is encased in the metal container, in the electric furnace of box-shaped, under the nitrogen circulation, carries out 2 hours heat treatment A in 540 ℃.In heat treatment A, the graphite crystallization precursor powder fusion of miniaturization becomes and the native graphite piece of the mixture of the heat treatment graphite crystallization precursor of compoundization equably.
The piece of the mixture of the heat treatment graphite crystallization precursor after will solidifying with Roughpulverizer (Jitian makes the roll crusher of manufacturing) is pulverized; It is broken to use the atomizer turbine type of the matsubo manufactured (mill) to carry out micro mist again, obtains the powder of median particle diameter 18.5 μ m.
The powder that obtains is packed in the container, under nitrogen atmosphere, under 1000 ℃, fired 1 hour with electric furnace.After firing, the powder that obtains (precursor mixture (F) before the heat treatment B) still is the form of powder, does not almost find fusion, fusion.
In addition, with the powder transfer after firing in graphite crucible, use directly the energising stove under inactive atmosphere in 3000 ℃ of graphitizations 5 hours, in order to prevent to sneak into oversize grain, use ASTM400 purpose sieve sieves 5 times repeatedly, obtains different orientation carbon complex (G).
[making 2 of negative material]
Mix with 100: 30 weight ratio with the native graphite that uses in [making 1 of negative material] with as the binder pitch of 88 ℃ of softening points that can graphited adhesive; Put into again in the kneader that is heated to 128 ℃ in advance, mixed 20 minutes with mastication type agitator.
Mixture after fully mediating is filled in the mould of the moulding press that is preheating to 108 ℃ in advance, placed 5 minutes, the extruding plunger applies 2kfg/cm when the temperature stabilization of mixture 2Pressure (0.20MPa) carries out moulding.Kept this pressure 1 minute, and stopped then driving, after pressure reduces end, the formed body after taking-up native graphite and graphite crystallization precursor powder are compound.
The formed body that obtains is encased in the metallic Fire-resistant cabinet as heatproof container, and in the space, fills graphite matter coke powder.Be warmed up to 1000 ℃ through 48 hours from room temperature with electric furnace, kept 3 hours down, carry out the devolatilization composition, fire at 1000 ℃.Then, formed body is placed in the graphite crucible, and in the space, fills graphite matter coke powder, use directly the energising stove in inactive atmosphere, to heat 4 hours in 3000 ℃, carry out graphitization.
After the formed body coarse crushing of jaw crusher with the graphite matter that obtains, employing will be pulverized grinding mill that blade rotational speed is set at 4000 rev/mins, and to carry out micro mist broken.In addition, when hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times, obtain different orientation carbon complex (H) in order to prevent to sneak into oversize grain.
[making 3 of negative material]
Except the use that makes [making 2 of negative material] is directly switched on heat treatment that stove carries out carrying out under 2200 ℃, according to obtaining different orientation carbon complex (I) with [making 2 of negative material] same method.
[making 4 of negative material]
Except the native graphite that makes [making 2 of negative material] is that median particle diameter is that 10 μ m, draw ratio are 2.3, tap density is 0.64g/cm 3, the BET specific area is 9.5m 2/ g, circularity are beyond 0.83 the coke, with [making 2 of negative material] likewise, obtain different orientation carbon complex (J).
[making 5 of negative material]
Except mixing with 100: 10: 30 mass ratio with the carborundum of the coke that uses in [making 4 of negative material], graphitization catalyst with as the binder pitch of 88 ℃ of softening points that can graphited adhesive; With [making 2 of negative material] likewise, obtain different orientation carbon complex (K).
[making 6 of negative material]
Except the native graphite that makes [making 2 of negative material] is that median particle diameter is that 19.8 μ m, draw ratio are 3.2, tap density is 0.47g/cm 3, the BET specific area is 5.9m 2/ g, circularity are beyond 0.81 the flakey native graphite, with [making 2 of negative material] likewise, obtain different orientation carbon complex (L).
[making 7 of negative material]
Except the native graphite that makes [making 2 of negative material] is that median particle diameter is that 35 μ m, draw ratio are 1.4, tap density is 1.02g/cm 3, the BET specific area is 3.9m 2/ g, circularity are beyond 0.90 the native graphite, with [making 2 of negative material] likewise, obtain different orientation carbon complex (M).
[making 8 of negative material]
Except the pulverizing blade rotational speed with [making 2 of negative material] is set at 1500 rev/mins, with [making 2 of negative material] likewise, obtain different orientation carbon complex (N).
[making 9 of negative material]
Except the native graphite that makes [making 2 of negative material] is that median particle diameter is that 6 μ m, draw ratio are 1.5, tap density is 0.15g/cm 3Native graphite beyond, with [making 2 of negative material] likewise, obtain different orientation carbon complex (O).
[making 10 of negative material]
The graphite crystallization precursor powder (E) that obtains in [making 1 of negative material] is encased in the metal container, in the electric furnace of box-shaped, under the nitrogen circulation, carries out 2 hours heat treatment A in 540 ℃.In heat treatment A, graphite crystallization precursor powder (E) fusion becomes bulk.
Heat treatment graphite crystallization precursor piece after will solidifying with Roughpulverizer (Jitian makes the roll crusher of manufacturing) is pulverized, and it is broken to use atomizer (the turbine type mill of matsubo manufactured) to carry out micro mist again, obtains the powder of median particle diameter 18.5 μ m.
The powder that obtains is put into container, under nitrogen atmosphere, under 1000 ℃, fired 1 hour with electric furnace.After firing, the powder that obtains still is the form of powder, does not almost find fusion, fusion.
In addition, with the powder transfer after firing in graphite crucible, use directly the energising stove under inactive atmosphere in 3000 ℃ of graphitizations 5 hours, in order to prevent to sneak into oversize grain, use ASTM400 purpose sieve sieves 5 times repeatedly, obtains carbonaceous material (P).
[making 11 of negative material]
The native graphite that uses in [making 1 of negative material] is encased in the metal container, in the electric furnace of box-shaped, under the nitrogen circulation, carries out 2 hours heat treatment A in 540 ℃.After heat treatment A, native graphite is not almost found fusion, fusion.The powder that obtains is put into container, under nitrogen atmosphere, under 1000 ℃, fired 1 hour with electric furnace.After firing, the powder that obtains still is the form of powder, does not almost find fusion, fusion.
In addition, with the powder transfer after firing in graphite crucible, use directly the energising stove under inactive atmosphere in 3000 ℃ of graphitizations 5 hours, in order to prevent to sneak into oversize grain, use ASTM400 purpose sieve sieves 5 times repeatedly, obtains carbonaceous material (Q).
[making 12 of negative material]
Carbonaceous material (P) and each 50 quality % of carbonaceous material (Q) are mixed, after evenly mixing, obtain carbonaceous material mixture (R).
Negative pole [5] [making of battery]
" anodal making 1 "
The cobalt acid lithium (LiCoO that in N-crassitude ketone solvent, mixes 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of the active material of the positive pole of this moment is 2.35g/cm 3
" making 1 of negative pole "
In 98 weight portion negative electrode active materials, add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the rolled copper foil two sides of thickness 10 μ m, and dry, rolls into thickness 75 μ m with press, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.The active material density of the negative pole of this moment is 1.35g/cm 3
" making 1 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the difluorophosphoric acid lithium salts (LiPO that also contains 0.3 quality % 2F 2).
" making 2 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the methanesulfonic acid trimethyl silyl ester that also contains 0.3 quality %.
" making 3 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that also contains 0.3 quality %.
" making 4 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).
(making 1 of battery)
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.The specified discharge capacity of this battery is about 6 ampere-hours (Ah), and the D.C. resistance of measuring with the 10kHz alternating current method is about 5 milliohms (m Ω).
Negative pole [5] embodiment 1
The negative electrode active material that uses " making 1 of negative pole " is the nonaqueous electrolytic solution of making in anodal and " making 1 of nonaqueous electrolytic solution " made in the negative pole processed of different orientation carbon complex (G), " anodal making 1 ", through the method manufacture batteries in " making 1 of battery ".Method and said determination method through described in following " evaluation of battery " item are measured this battery.
Negative pole [5] embodiment 2
Except the negative electrode active material of negative pole [5] embodiment 1 " making 1 of negative pole " uses the different orientation carbon complex (H), with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] embodiment 3
Except the negative electrode active material of negative pole [5] embodiment 1 " making 1 of negative pole " uses the different orientation carbon complex (I), with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] embodiment 4
Except the negative electrode active material of negative pole [5] embodiment 1 " making 1 of negative pole " uses the different orientation carbon complex (J), with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] embodiment 5
Except the negative electrode active material of negative pole [5] embodiment 1 " making 1 of negative pole " uses the different orientation carbon complex (K), with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] embodiment 6
Except the negative electrode active material of negative pole [5] embodiment 1 " making 1 of negative pole " uses the different orientation carbon complex (L), with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] embodiment 7
Except the negative electrode active material of negative pole [5] embodiment 1 " making 1 of negative pole " uses the different orientation carbon complex (M), with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] embodiment 8
Except the negative electrode active material of negative pole [5] embodiment 1 " making 1 of negative pole " uses the different orientation carbon complex (N), with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] embodiment 9
Except the negative electrode active material of negative pole [5] embodiment 1 " making 1 of negative pole " uses the different orientation carbon complex (O), with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] embodiment 10～18
Except the nonaqueous electrolytic solution with negative pole [5] embodiment 1～9 changes the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " into, manufacture batteries likewise, and carry out cell evaluation after the same method.
Negative pole [5] embodiment 19～27
Except the nonaqueous electrolytic solution with negative pole [5] embodiment 1～9 changes the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " into, manufacture batteries likewise, and carry out cell evaluation after the same method.
Negative pole [5] comparative example 1
Except the negative electrode active material of negative pole [5] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (P), with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] comparative example 2
Except the nonaqueous electrolytic solution with negative pole [5] comparative example 1 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [5] comparative example 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] comparative example 3
Except the negative electrode active material of negative pole [5] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (Q), with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] comparative example 4
Except the nonaqueous electrolytic solution with negative pole [5] comparative example 3 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [5] comparative example 3 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] comparative example 5
Except the negative electrode active material of negative pole [5] embodiment 1 " making 1 of negative pole " uses the carbonaceous material mixture (R), with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] comparative example 6
Except the nonaqueous electrolytic solution with negative pole [5] comparative example 5 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [5] comparative example 5 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] comparative example 7
Except the nonaqueous electrolytic solution with negative pole [5] embodiment 1 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [5] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] comparative example 8
Except the nonaqueous electrolytic solution with negative pole [5] embodiment 2 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [5] embodiment 2 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] comparative example 9
Except the nonaqueous electrolytic solution with negative pole [5] embodiment 4 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [5] embodiment 4 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] comparative example 10
Except the nonaqueous electrolytic solution with negative pole [5] embodiment 5 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [5] embodiment 5 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.
Negative pole [5] comparative example 11～13
Except the nonaqueous electrolytic solution with negative pole [5] comparative example 1,3,5 changes the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " into, manufacture batteries likewise, and carry out cell evaluation after the same method.
Negative pole [5] comparative example 14～16
Except the nonaqueous electrolytic solution with negative pole [5] comparative example 1,3,5 changes the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " into, manufacture batteries likewise, and carry out cell evaluation after the same method.
Negative pole [5] " evaluation of battery "
(solid measure)
To battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.2V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.With the 0.2C discharge capacity of the 5th circulation of this moment as initial capacity.Then carry out the output test shown in following.
(low depth of charge cyclic test)
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.20% of the initial capacity of measuring when reaching solid measure with the constant-current constant-voltage method capacity of charging to of 2C; And reach charging upper voltage limit 4.2V; Constant current with 2C is discharged to final discharging voltage 3.0V then; With this charge and discharge cycles as 1 circulation, and carry out repeatedly this circulation until 500 the circulation.
Battery after finishing for cyclic test carries out discharging and recharging of 3 circulations under 25 ℃ of environment, with the 0.2C discharge capacity of the 3rd circulation as the low depth of charge capacity afterwards that circulates.Low depth of charge circulation back capacity by initial capacity of measuring before the cyclic test and cyclic test finish to measure the back is obtained the circulation conservation rate according to following calculating formula.
Circulation conservation rate (%)=100 * low depth of charge circulation back capacity/initial capacity
The negative electrode active material guide look of using in negative pole [5] embodiment and negative pole [5] comparative example is shown in negative pole [5] table 1, and the result of cell evaluation is shown in negative pole [5] table 2 and negative pole [5] table 3.Result by negative pole [5] table 2 and negative pole [5] table 3 can know; Through containing difluorophosphoric acid lithium salts, methanesulfonic acid trimethyl silyl ester, hexamethyl cyclotrisiloxane; And combination is as the different orientation carbon complex of negative electrode active material, can make the capability retention (circulation conservation rate) after the cyclic test of low depth of charge obtain tremendous raising.
Negative pole [5] table 1
Figure BDA0000087738240002921
Negative pole [5] table 2
[table 44]
Figure BDA0000087738240002931
Negative pole [5] table 3
[table 45]
Figure BDA0000087738240002941
Negative pole [6] [making of negative electrode active material]
(making 1 of negative electrode active material)
In order to prevent in commercially available native graphite powder (A), to sneak into oversize grain, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as carbonaceous material (B).
(making 2 of negative electrode active material)
With the atomizer turbine type of the matsubo manufactured (mill) to commercially available native graphite powder (C) (d002:0.336nm, above, the Raman R value of Lc:100nm: 0.11, tap density: 0.46g/cm 3, real density: 2.27g/cm 3, volume average particle size: 28.7 μ m) handle, in order to prevent to sneak into oversize grain, use ASTM400 purpose sieve to sieve repeatedly 5 times, preparation carbonaceous material (D).
(making 3 of negative electrode active material)
Use hybrid system ((strain) nara machinery is made the hybrid system NHS-1 type of manufacturing) native graphite powder (C) to be handled with treating capacity 90g, rotor peripheral speed 60m/s, 3 minutes processing times; Carry out spheroidization thus; In addition; In order to prevent to sneak into oversize grain, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as carbonaceous material (E).Through carrying out this operation repeatedly, guaranteed that battery makes necessary amount.
(making 4 of negative electrode active material)
Use hybrid system with treating capacity 90g, rotor peripheral speed 30m/s, the condition in 1 minute processing time to commercially available native graphite powder (F) (d002:0.336nm, above, the Raman R value of Lc:100nm: 0.09, tap density: 0.57g/cm 3, real density: 2.26g/cm 3, volume average particle size: 85.4 μ m) carry out spheroidization, in addition, in order to prevent to sneak into oversize grain, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as carbonaceous material (G).Through carrying out this operation repeatedly, guaranteed that battery makes necessary amount.
(making 5 of negative electrode active material)
With the quinoline non-soluble composition be coal tar asphalt below the 0.05 quality % in reacting furnace in 460 ℃ of heat treatments 10 hours, obtain the carbonization treatment precursor of the bulk with meltbility of 385 ℃ of softening points.The carbonization treatment precursor of the bulk that obtains is encased in the metal container, in the electric furnace of box-shaped, under the nitrogen circulation, carries out heat treatment in 2 hours in 1000 ℃.With the unbodied pulverizing that Roughpulverizer (Jitian makes the roll crusher of manufacturing) will obtain, it is broken to use the atomizer turbine type of the matsubo manufactured (mill) to carry out micro mist again, obtains the amorphous powder of volume reference average grain diameter 18 μ m.In order to sneak into oversize grain in the powder that prevents to obtain, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as carbonaceous material (H).
(making 6 of negative electrode active material)
Transfer to the carbonaceous material (H) that obtains in (making 5 of negative electrode active material) in the graphite crucible again; Use directly the energising stove carries out 5 hours graphitizations in 3000 ℃ under inactive atmosphere; In order to sneak into oversize grain in the powder that prevents to obtain, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains here as carbonaceous material (I).
(making 7 of negative electrode active material)
Use hybrid system the carbonaceous material (I) that obtains in (making 6 of negative electrode active material) to be carried out spheroidization with treating capacity 90g, rotor peripheral speed 30m/s, the condition in 1 minute processing time; In addition; In order to prevent to sneak into oversize grain, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as carbonaceous material (J).Through carrying out this operation repeatedly, guaranteed that battery makes necessary amount.
(making 8 of negative electrode active material)
The native graphite powder (K) that purity is lower than native graphite powder (A) (d002:0.336nm, above, the Raman R value of Lc:100nm: 0.10, tap density: 0.49g/cm 3, real density: 2.27g/cm 3, volume average particle size: 27.3 μ m, ash content 0.5 quality %) with (making 3 of negative electrode active material) same condition under carry out spheroidization and screening, the preparation carbonaceous material (L).Through carrying out this operation repeatedly, guaranteed that battery makes necessary amount.
(making 9 of negative electrode active material)
In order to prevent in commercially available flakey native graphite powder (M), to sneak into oversize grain, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as carbonaceous material (N).
Measure shape and the rerum natura of carbonaceous material (B), (D), (E), (G), (H), (I), (J), (L), (N) according to above-mentioned method.The result is shown in negative pole [6] table 1.
Negative pole [6] table 1
Figure BDA0000087738240002971
Negative pole [6] [making of battery]
" anodal making 1 "
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of the active material of the positive pole of this moment is 2.35g/cm 3
" making 1 of negative pole "
In 98 weight portion negative electrode active materials, add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the rolled copper foil two sides of thickness 10 μ m, and dry, rolls into thickness 75 μ m with press, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.The density of the active material of the negative pole of this moment is 1.35g/cm 3
" making 1 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the difluorophosphoric acid lithium salts (LiPO that also contains 0.3 quality % 2F 2).
" making 2 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the methanesulfonic acid trimethyl silyl ester that also contains 0.3 quality %.
" making 3 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that also contains 0.3 quality %.
" making 4 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).
" making 1 of battery "
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.The specified discharge capacity of this battery is about 6 ampere-hours (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms (m Ω).The ratio of the summation that the summation of anodal electrode area is long-pending with respect to the case surface of battery is 20.6.
Negative pole [6] embodiment 1
Use the nonaqueous electrolytic solution of making in anodal and " making 1 of nonaqueous electrolytic solution " made in the negative pole that the negative electrode active material of " making 1 of negative pole " processes as carbonaceous material (D), " anodal making 1 ", through the method manufacture batteries in " making 1 of battery ".Method and said determination method through described in following " evaluation of battery " item are measured this battery.The result is shown in table 2 (negative pole [6] table 2).
Negative pole [6] embodiment 2
Except the negative electrode active material in negative pole [6] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (E), with negative pole [6] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] embodiment 3
Except the negative electrode active material in negative pole [6] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (G), with negative pole [6] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] embodiment 4
Except the negative electrode active material in negative pole [6] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (J), with negative pole [6] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] embodiment 5
Except the negative electrode active material in negative pole [6] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (L), with negative pole [6] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] embodiment 6～10
Except the nonaqueous electrolytic solution with negative pole [6] embodiment 1～5 changed the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " item into, difference is manufacture batteries after the same method, and estimates.The result is shown in negative pole [6] table 2.
Negative pole [6] embodiment 11～15
Except the nonaqueous electrolytic solution with negative pole [6] embodiment 1～5 changed the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " item into, difference is manufacture batteries after the same method, and estimates.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 1
Except the negative electrode active material in negative pole [6] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (B), with negative pole [6] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 2
Except the nonaqueous electrolytic solution with negative pole [6] comparative example 1 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [6] comparative example 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 3
Except the nonaqueous electrolytic solution with negative pole [6] embodiment 2 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [6] embodiment 2 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 4
Except the nonaqueous electrolytic solution with negative pole [6] embodiment 1 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [6] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 5
Except the negative electrode active material in negative pole [6] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (H), with negative pole [6] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 6
Except the nonaqueous electrolytic solution with negative pole [6] comparative example 5 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [6] comparative example 5 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 7
Except the negative electrode active material in negative pole [6] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (N), with negative pole [6] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 8
Except the nonaqueous electrolytic solution with negative pole [6] comparative example 7 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [6] comparative example 7 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 9
Except the negative electrode active material in negative pole [6] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (I), with negative pole [6] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 10
Except the nonaqueous electrolytic solution with negative pole [6] comparative example 9 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [6] comparative example 9 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 11～14
Except the nonaqueous electrolytic solution with negative pole [6] comparative example 1,5,7,9 changed the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " item into, difference is manufacture batteries after the same method, and estimates.The result is shown in negative pole [6] table 2.
Negative pole [6] comparative example 15～18
Except the nonaqueous electrolytic solution with negative pole [6] comparative example 1,5,7,9 changed the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " item into, difference is manufacture batteries after the same method, and estimates.The result is shown in negative pole [6] table 2.
Negative pole [6] " evaluation of battery "
(solid measure)
To the new battery without charge and discharge cycles, the initial stage of carrying out 5 circulations at 25 ℃, the voltage range of 4.1V～3.0V discharges and recharges (voltage range 4.1V～3.0V).With the 0.2C of the 5th circulation of this moment (as 1C, said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate) with the current value of 1 hour discharge rated capacity, down with) discharge capacity as initial capacity.
(output test 1)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, under-30 ℃ of environment, leaves standstill 3 hours, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 5.0C respectively then, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as initial stage low temperature power output (W).
(output test 2)
After output test 1, implement the low-voltage charging of 1 hour 4.1V, then battery is transferred under 25 ℃ the environment, after 15 minutes, discharged for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 5.0C, measure the 10th second voltage.Power output (W) when the leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded rises as temperature.
Result by output test 1 and output test 2 calculates temperature adaptation power output raising rate (%) through following calculating formula.
Temperature adapts to power output raising rate (%)
=[(power output (W)/initial stage low temperature power output (W) when temperature rises)-1] * 100
Impedance Rct and double-deck capacity C dl in negative pole [6] table 2 are to one of contributive parameter of power output, and the value of impedance Rct is more little, and perhaps the value of double-deck capacity C dl is big more, and then power output has the tendency of improvement more.In addition, " impedance Rct " and " double-deck capacity C dl " obtains through the method put down in writing of part of explanation impedance.
Negative pole [6] table 2
[table 47]
Figure BDA0000087738240003031
Result by negative pole [6] table 2 can know; Through containing difluorophosphoric acid lithium salts, methanesulfonic acid trimethyl silyl ester, hexamethyl cyclotrisiloxane; And the interplanar distance (d002) of (002) face of contain circularity and be more than 0.85, wide-angle x-ray diffraction being measured be lower than 0.337 and Raman R value be 0.12～0.8 graphite matter carbon particle as negative electrode active material, can make the power output under-30 ℃ the low-temperature condition be able to accelerate along with the recovery of temperature rising tremendously.
Negative pole [7] < making of negative pole >
(making 1 of negative pole)
The mixture (area of Si and C is than the plectane that is roughly 100 to 9) that uses Si and C is as target material, and using average surface roughness (Ra) is that 0.2 μ m, hot strength are 280N/mm 2, 0.2% endurance is 220N/mm 2, thickness be the electrolytic copper foil of 18 μ m as the collector body substrate, adopt dc sputtering device (" HSM-52 " of Shimadzu Seisakusho Ltd.'s manufactured) to carry out the film forming of 45 minutes active material films, obtain film cathode (1).
At this moment, the collector body substrate is installed on the water-cooled anchor clamps, is maintained at about 25 ℃, and container is vacuum-drawn against 4 * 10 in advance -4Pa, the highly purified argon gas of circulation 40sccm in container is after the aperture of adjusting main valve becomes the atmosphere of 1.6Pa, at power density 4.7W/cm 2, carry out film forming under the about 1.8nm/ of deposition velocity (film forming speed) second (0.108 μ m/ branch).The oxygen concentration of this sputter gas is 0.0010%.In addition, in order to remove the oxide-film of electrolytic copper foil surface, before forming film, carry out reverse sputtering and carry out the etching of substrate surface.
Observe through scanning electron microscope (SEM) is carried out in the cross section of the film of the film cathode (1) that obtains, the thickness of the film after the film forming is 6 μ m (with reference to Fig. 1 (a)).In addition, when carrying out the composition analysis of film according to following method with XPS, containing Elements C in the film is 24 atom %, and the C concentration ratio Q (C) with respect to Elements C concentration among the SiC is equivalent to 0.49.In addition, if recently represent with atomic concentration, Si/C/O=1.00/0.33/0.04 then.In addition, when adopting Raman mensuration to obtain the Raman value of film according to following method, RC=0.05, the peak that does not detect RSC=sc, RS=0.55.In addition, when carrying out the X-ray diffraction mensuration of film, do not detect the peak of clear and definite SiC, XIsz=0.38 according to following method.The result is shown in negative pole [7] table 1.
In addition; Adopt electron probe microanalyzer (EPMA) to measure in the film Si when the mass concentration of film thickness direction distributes according to following method; Shown in Fig. 1 (b), poor (absolute value) of the maximum of Si or minimum value and mean value is in 25%, and Si is film forming continuously from the collector body in fact.In addition, when measuring the distribution of the Elements C in the film, shown in Fig. 1 (c), Elements C evenly distributes with the size below the 1 μ m in the Si film.
(making 2 of negative pole)
Except target material uses Si,, make film cathode (2) with (making 1 of negative pole) film forming active material film likewise.
Observe through scanning electron microscope (SEM) is carried out in the cross section of the film of the film cathode (2) that obtains, the thickness of the film after the film forming is 6 μ m.In addition, when carrying out the composition analysis of film, do not contain Elements C, N in the film, when representing with the atomic concentration ratio, Si/O=1.00/0.02.In addition, when obtaining the Raman value of film, do not detect the peak of RC=c, the peak that does not detect RSC=sc, RS=0.30.The result is shown in negative pole [7] table 1.
< XPS mensuration >
Measure as X ray photoelectricity optical spectroscopy; Use X ray photoelectricity optical splitter (for example, " ESCA " of ulvac-phi manufactured), film cathode is placed on the test portion platform and makes have an even surface;, carry out depth curve and measure as x-ray source with the K alpha ray of aluminium while carry out the Ar sputter.Must reach Si2p under the certain degree of depth of concentration (for example 200nm) (90～110eV), C1s (280～300eV) and O1s (525～545eV) spectrogram.The summit of the C1s that obtains is set at 284.5eV carries out charged compensation, obtain the peak area of the spectrogram of Si2p, C1s and O1s, multiply by device sensitivity coefficient again, calculate the atomic concentration of Si, C and O respectively.Atomic concentration by this Si, O and the C that obtain calculates atomic concentration than Si/C/O (Si atomic concentration/C atomic concentration/O atomic concentration), and it is defined as the composition value Si/C/O of film.
< Raman mensuration >
Measure as Raman, use raman spectroscopy device (" raman spectroscopy device " that for example Japanese beam split society makes), film cathode is installed in the cell, mensuration is that the irradiation of the specimen surface in pond argon laser is carried out.
In addition, the Raman condition determination here is following.
Argon laser wavelength: 514.5nm
Laser power on the sample: 15～40mW
Resolution: 10～20cm -1
Measurement range: 200cm -1～1900cm -1
Smooth treatment: simple average, convolution 15 points
< X-ray diffraction mensuration >
Measure as X-ray diffraction, use " RINT2000PC " of manufactured of science, film cathode is installed in the cell, use the out-of-plane method to carry out the mensuration of 2 θ=10～70 degree scopes.Background compensation is with being connected and carrying out with straight line with 40～45 degree are neighbouring near 2 θ=15～20 degree.
< EPMA mensuration >
As the mass concentration distribution of the film thickness direction that adopts EPMA to measure or the distributional analysis in film cross section; Use electron probe microanalyzer (" JXA-8100 " of JEOL manufactured), do not carry out resin embedding and the film cathode of processing the cross section with slicing machine is carried out the elementary analysis from the collector body to the film surface.When the mass concentration of obtaining film thickness direction distributes, use summation with the element of measuring to be converted into 100% and the value that obtains is obtained Si and distributed in the mass concentration of film thickness direction.
Negative pole [7] table 1
[table 48]
Figure BDA0000087738240003061
In negative pole [7] table 1, (Si) be not equivalent to element Z.
Negative pole [7] < anodal making >
(anodal making 1)
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on face of aluminium foil of thickness 15 μ m, and dry, roll into thickness 80 μ m with press.
Negative pole [7] < making of nonaqueous electrolytic solution >
(making 1 of nonaqueous electrolytic solution)
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the difluorophosphoric acid lithium salts (LiPO that also contains 0.3 quality % 2F 2).
(making 2 of nonaqueous electrolytic solution)
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the methanesulfonic acid trimethyl silyl ester that also contains 0.3 quality %.
(making 3 of nonaqueous electrolytic solution)
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that also contains 0.3 quality %.
(making 4 of nonaqueous electrolytic solution)
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).
Negative pole [7] < making of lithium secondary battery >
Film cathode is become 10mm φ with anodal punching; After carrying out vacuumize under 110 ℃, transfer in the gloves work box, under the argon atmosphere, become the polyethylene separator of 14mm φ that positive pole and negative pole is opposed through punching; And the adding nonaqueous electrolytic solution, make 2032 type coin batteries (lithium secondary battery).
Negative pole [7] embodiment 1
Use the nonaqueous electrolytic solution of making in anodal and (making 1 of nonaqueous electrolytic solution) made in the negative pole made in (making 1 of negative pole), (anodal making), make coin battery through the method in " making of lithium secondary battery ".Obtain the battery behavior of this secondary cell through the method described in following < cell evaluation>item.
Negative pole [7] embodiment 2
Except the nonaqueous electrolytic solution with negative pole [7] embodiment 1 changes the nonaqueous electrolytic solution of making in (making 2 of nonaqueous electrolytic solution) into,, and adopt the method for < evaluation of battery>record to carry out cell evaluation with negative pole [7] embodiment 1 manufacture batteries likewise.The result is shown in negative pole [7] table 2.
Negative pole [7] embodiment 3
Except the nonaqueous electrolytic solution with negative pole [7] embodiment 1 changes the nonaqueous electrolytic solution of making in (making 3 of nonaqueous electrolytic solution) into,, and adopt the method for < evaluation of battery>record to carry out cell evaluation with negative pole [7] embodiment 1 manufacture batteries likewise.The result is shown in negative pole [7] table 2.
Negative pole [7] comparative example 1
Except the nonaqueous electrolytic solution with negative pole [7] embodiment 1 changes the nonaqueous electrolytic solution of making in (making 4 of nonaqueous electrolytic solution) into,, and adopt the method for < evaluation of battery>record to carry out cell evaluation with negative pole [7] embodiment 1 manufacture batteries likewise.The result is shown in negative pole [7] table 2.
Negative pole [7] comparative example 2
Except the negative pole with negative pole [7] embodiment 1 changes the electrode of making in (making 2 of negative pole) into,, and adopt the method for < evaluation of battery>record to carry out cell evaluation with negative pole [7] embodiment 1 manufacture batteries likewise.The result is shown in negative pole [7] table 2.
Negative pole [7] comparative example 3
Except the nonaqueous electrolytic solution with negative pole [7] comparative example 2 changes the nonaqueous electrolytic solution of making in (making 2 of nonaqueous electrolytic solution) into,, and adopt the method for < evaluation of battery>record to carry out cell evaluation with negative pole [7] comparative example 2 manufacture batteries likewise.The result is shown in negative pole [7] table 2.
Negative pole [7] comparative example 4
Except the nonaqueous electrolytic solution with negative pole [7] comparative example 2 changes the nonaqueous electrolytic solution of making in (making 3 of nonaqueous electrolytic solution) into,, and adopt the method for < evaluation of battery>record to carry out cell evaluation with negative pole [7] comparative example 2 manufacture batteries likewise.The result is shown in negative pole [7] table 2.
Negative pole [7] comparative example 5
Except the nonaqueous electrolytic solution with negative pole [7] comparative example 2 changes the nonaqueous electrolytic solution of making in (making 4 of nonaqueous electrolytic solution) into,, and adopt the method for " evaluation of battery " record to carry out cell evaluation with negative pole [7] comparative example 2 manufacture batteries likewise.The result is shown in negative pole [7] table 2.
Negative pole [7] < evaluation of battery >
According to following method, the coin battery of making in < making of lithium secondary battery>item is carried out the evaluation of discharge capacity, the Receptive mensuration of charging.
" evaluation of discharge capacity "
With 1.23mA/cm 2Current density lithium is charged to 4.2V to electrode, the constant-potential charge with 4.2V reaches 0.123mA to current value again, in negative pole after the elements doped lithium, with 1.23mA/cm 2Current density lithium is discharged up to 2.5V to electrode, this charge and discharge cycles is carried out 5 circulations repeatedly, with the mean value of discharge of the 3rd～5 circulation as discharge capacity.In addition, under the situation as the discharge capacity of unit mass, the active material quality can become the quality of Copper Foil of the same area to try to achieve through deducted punching by the negative pole quality, and according to computes.
Discharge capacity (mAh/g)
=[the average discharge capacity (mAh) of the 3rd～5 circulation]/[active material quality (g)]
Active material quality (g)=negative pole quality (g)-Copper Foil quality of the same area (g)
" the Receptive mensuration of charging "
Under 25 ℃ environment; Will with 0.2C (with 1 hour the discharge rated capacity current value as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) capacity when being charged to 4.2V is as the 0.2C charging capacity, discharges into 2.5V with 0.2C again; Be charged to 4.2V with 1C then, with this moment capacity as the 1C charging capacity.Obtain the charging acceptance by the result who obtains through following formula.
Charging acceptance (%)=100 * [1C charging capacity]/[0.2C charging capacity]
Negative pole [7] table 2
[table 49]
Figure BDA0000087738240003091
Result by negative pole [7] table 2 can know; In nonaqueous electrolytic solution, contain difluorophosphoric acid lithium salts, methanesulfonic acid trimethyl silyl ester or hexamethyl cyclotrisiloxane; And use and contain the lithium secondary battery of the negative electrode active material (C) of multielement as negative electrode active material; Can make receiving property of charging be able to improve tremendously; The said negative electrode active material (C) that contains multielement contains at least a lithium occlusion metal (A) and/or lithium occlusion alloy (B), and contains at least a element (element Z) that is selected among C or the N.
Negative pole [8] [making of negative electrode active material]
(making 1 of negative electrode active material)
Use hybrid system ((strain) nara machinery is made the hybrid system NHS-1 type of manufacturing) with treating capacity 90g, rotor peripheral speed 60m/s, the condition in 3 minutes processing times to native graphite powder (d002:0.336nm, above, the Raman R value of Lc:100nm: 0.11, tap density: 0.46g/cm 3, real density: 2.27g/cm 3, the volume reference average grain diameter: 35.4 μ m) handle, carry out spheroidization thus, in addition, in order to prevent to sneak into oversize grain, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as carbonaceous material (A).Through carrying out this operation repeatedly, guaranteed that battery makes necessary amount.
(making 2 of negative electrode active material)
With wind classification device commercially available flakey native graphite powder is removed micro mist,, use ASTM400 purpose sieve to sieve repeatedly 5 times in order to sneak into oversize grain in the powder that prevents to obtain.With the negative electrode active material that obtains like this as carbonaceous material (B).
(making 3 of negative electrode active material)
With the quinoline non-soluble composition be coal tar asphalt below the 0.05 quality % in reacting furnace in 460 ℃ of heat treatments 10 hours, obtain the block carbonization treatment precursor with meltbility of 385 ℃ of softening points.The block carbonization treatment precursor that obtains is encased in the metal container, in the electric furnace of box-shaped, under the nitrogen circulation, carries out heat treatment in 2 hours in 1000 ℃.The unbodied pulverizing that will obtain with Roughpulverizer (Jitian makes the roll crusher of manufacturing); It is broken to use the atomizer turbine type of the matsubo manufactured (mill) to carry out micro mist again; Remove micro mist with wind classification device then; In order to sneak into oversize grain in the powder that prevents to obtain, use ASTM400 purpose sieve to sieve repeatedly 5 times, obtain the amorphous powder that the volume reference particle diameter is 9 μ m.With the negative electrode active material that obtains like this as carbonaceous material (C).
(making 4 of negative electrode active material)
The petroleum-type heavy oil that obtains when in carbonaceous material (A), mixing the naphtha pyrolysis; In non-active gas, implement 1300 ℃ carbonization treatment; Then; Obtain carbonaceous material through sinter is carried out hierarchical processing, said carbonaceous material is on carbonaceous material (A) particle surface, to have coated the carbonaceous material that has different crystalline carbonaceous material and obtain.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times, obtain carbonaceous material (D) in order to prevent to sneak into oversize grain.Can confirm that from carbon yield the negative electrode active material powder that obtains is coated by the carbonaceous that comes from petroleum-type heavy oil that with respect to 95 weight portion graphite is 5 weight.
(making 5 of negative electrode active material)
80 quality % carbonaceous material (A) and 20 quality % carbonaceous material (B) are mixed until evenly, process and mix carbonaceous material (E).
(making 6 of negative electrode active material)
95 quality % carbonaceous material (A) and 5 quality % carbonaceous material (C) are mixed until evenly, process and mix carbonaceous material (F).
(making 7 of negative electrode active material)
80 quality % carbonaceous material (D) and 20 quality % carbonaceous material (A) are mixed until evenly, process and mix carbonaceous material (G).
Obtain carbonaceous material (A), (B), (C) and the rerum natura of mixing carbonaceous material (E), (F), (G), the shape etc. of making in the making 1～7 of negative electrode active material with said method.The result concludes and is shown in negative pole [8] table 1.
Negative pole [8] table 1
Negative pole [8] [making of battery]
" anodal making 1 "
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of the active material of the positive pole of this moment is 2.35g/cm 3
" making 1 of negative pole "
In 98 weight portion negative electrode active materials, add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the rolled copper foil two sides of thickness 10 μ m, and dry, rolls into thickness 75 μ m with press, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.The density of the active material of the negative pole of this moment is 1.35g/cm 3
" making 1 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the difluorophosphoric acid lithium salts (LiPO that also contains 0.3 quality % 2F 2).
" making 2 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the methanesulfonic acid trimethyl silyl ester that also contains 0.3 quality %.
" making 3 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that also contains 0.3 quality %.
" making 4 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).
" making 1 of battery "
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.The specified discharge capacity of this battery is about 6 ampere-hours (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms (m Ω).The ratio of the summation that the summation of anodal electrode area is long-pending with respect to the case surface of battery is 20.6.
Negative pole [8] embodiment 1
The nonaqueous electrolytic solution of making in the positive pole of making and " making 1 of nonaqueous electrolytic solution " item in the negative pole that the negative electrode active material of use " making 1 of negative pole " item is made for mixing carbonaceous material (E), " anodal making 1 " item is through the method manufacture batteries in " making 1 of battery " item.This battery is carried out the cell evaluation described in following " evaluation of battery " item.The result is shown in negative pole [8] table 2.
Negative pole [8] embodiment 2
Except using, mixes the carbonaceous material (F) negative electrode active material of negative pole [8] embodiment 1 " making 1 of negative pole ", with negative pole [8] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [8] table 2.
Negative pole [8] embodiment 3
Except using, mixes the carbonaceous material (G) negative electrode active material of negative pole [8] embodiment 1 " making 1 of negative pole ", with negative pole [8] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [8] table 2.
Negative pole [8] embodiment 4～6
Except the nonaqueous electrolytic solution with negative pole [8] embodiment 1～3 changed the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " item into, difference is manufacture batteries after the same method, and carries out cell evaluation.The result is shown in negative pole [8] table 2.
Negative pole [8] embodiment 7～9
Except the nonaqueous electrolytic solution with negative pole [8] embodiment 1～3 changed the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " item into, difference is manufacture batteries after the same method, and carries out cell evaluation.The result is shown in negative pole [8] table 2.
Negative pole [8] comparative example 1
Except the nonaqueous electrolytic solution with negative pole [8] embodiment 1 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [8] embodiment 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [8] table 2.
Negative pole [8] comparative example 2
Except the nonaqueous electrolytic solution with negative pole [8] embodiment 2 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into, with negative pole [8] embodiment 2 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [8] table 2.
Negative pole [8] comparative example 3
Except the negative electrode active material of " making 1 of negative pole " of negative pole [8] comparative example 1 uses the carbonaceous material (A), with negative pole [8] comparative example 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [8] table 2.
Negative pole [8] comparative example 4
Except the negative electrode active material of " making 1 of negative pole " of negative pole [8] comparative example 1 uses the carbonaceous material (B), with negative pole [8] comparative example 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [8] table 2.
Negative pole [8] comparative example 5
Except the negative electrode active material of " making 1 of negative pole " of negative pole [8] comparative example 1 uses the carbonaceous material (C), with negative pole [8] comparative example 1 manufacture batteries likewise, and the cell evaluation that carries out " evaluation of a battery " record.The result is shown in negative pole [8] table 2.
Negative pole [8] comparative example 6～8
Except the nonaqueous electrolytic solution with negative pole [8] comparative example 3～5 changed the nonaqueous electrolytic solution of making in " making 1 of nonaqueous electrolytic solution " item into, difference is manufacture batteries after the same method, and estimates.The result is shown in negative pole [8] table 2.
Negative pole [8] comparative example 9～11
Except the nonaqueous electrolytic solution with negative pole [8] comparative example 3～5 changed the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " item into, difference is manufacture batteries after the same method, and estimates.The result is shown in negative pole [8] table 2.
Negative pole [8] comparative example 12～14
Except the nonaqueous electrolytic solution with negative pole [8] comparative example 3～5 changed the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " item into, difference is manufacture batteries after the same method, and estimates.The result is shown in negative pole [8] table 2.
Negative pole [8] " evaluation of battery "
(solid measure)
To the new battery without charge and discharge cycles, the initial stage of carrying out 5 circulations at 25 ℃, the voltage range of 4.1V～3.0V discharges and recharges (voltage range 4.1V～3.0V).With the 0.2C of the 5th circulation of this moment (as 1C, said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate) with the current value of 1 hour discharge rated capacity, down with) discharge capacity as initial capacity.
(output test 1)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, under-30 ℃ of environment, leaves standstill 3 hours, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 5.0C respectively then, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as low temperature power output (W).
(cyclic test)
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.Charge to charging upper voltage limit 4.2V with the constant-current constant-voltage method of 2C, the constant current with 2C is discharged to final discharging voltage 3.0V then, and this charge and discharge cycles as 1 circulation, and is carried out this circulation repeatedly and circulated until 500.Battery after finishing for cyclic test carries out discharging and recharging of 3 circulations under 25 ℃ of environment, with the 0.2C discharge capacity of the 3rd circulation as circulation back capacity.Obtain the circulation conservation rate by capacity after the circulation of initial capacity of measuring before the cyclic test and cyclic test end back mensuration according to following calculating formula.
Circulation conservation rate (%)=100 * circulation back capacity/initial capacity
Negative pole [8] table 2
[table 51]
Figure BDA0000087738240003161
Result by negative pole [8] table 2 can know; Through containing difluorophosphoric acid lithium salts, methanesulfonic acid trimethyl silyl ester, hexamethyl cyclotrisiloxane; And using the negative pole that contains the negative electrode active material of different in kind more than 2 kinds, cycle characteristics and low temperature power output are all good.
Negative pole [9] [10] [making of negative electrode active material]
(making 1 of negative electrode active material)
Use spheroidization processing unit (nara machinery is made the hybrid system of manufacturing) with flakey native graphite (d002:0.336nm, Lc:100nm above, the Raman R value: 0.11, real density: 2.27g/cm of rotating speed 6500rpm to the about 150 μ m of the median particle diameter of high-purity processing 3, ash content: 0.05 quality %) carry out 5 minutes spheroidizations and handle, re-use wind-force formula grader (OMC-100 that seishin enterprise-like corporation makes) and remove 45 quality % micro mists, obtain carbonaceous material (A).
(making 2 of negative electrode active material)
The carbonaceous material (A) of making in (making 1 of negative electrode active material) is encased in the graphite crucible, uses directly the energising stove under inactive atmosphere, to carry out heat treatment in 5 hours in 3000 ℃, obtain carbonaceous material (B).
(making 3 of negative electrode active material)
The petroleum-type heavy oil that obtains when in the carbonaceous material (A) that (making 1 of negative electrode active material) made, mixing the naphtha pyrolysis; In non-active gas, implement 1300 ℃ carbonization treatment; Then; Obtain carbonaceous material through sinter is carried out hierarchical processing, said carbonaceous material is on carbonaceous material (A) particle surface, to have coated the carbonaceous material that has different crystalline carbonaceous material and obtain.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times, obtain carbonaceous material (C) in order to prevent to sneak into oversize grain.Can confirm that from carbon yield the negative electrode active material powder that obtains is coated by the carbonaceous that comes from petroleum-type heavy oil that with respect to 95 weight portion graphite is 5 weight.
(making 4 of negative electrode active material)
With the quinoline non-soluble composition be coal tar asphalt below the 0.05 quality % in reacting furnace in 460 ℃ of heat treatments 10 hours, obtain the block carbonization treatment precursor with meltbility of 385 ℃ of softening points.The block carbonization treatment precursor that obtains is encased in the metal container, in the electric furnace of box-shaped, under the nitrogen circulation, carries out heat treatment in 2 hours in 1000 ℃.With the unbodied pulverizing that Roughpulverizer (Jitian makes the roll crusher of manufacturing) will obtain, it is broken to use the atomizer turbine type of the matsubo manufactured (mill) to carry out micro mist again, obtains the amorphous powder of volume reference average grain diameter 17 μ m.In order to sneak into oversize grain in the powder that prevents to obtain, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative electrode active material that obtains like this as carbonaceous material (D).
The shape and the rerum natura of the carbonaceous material (A) of measure making with said method, carbonaceous material (B), carbonaceous material (C), carbonaceous material (D).The result is shown in negative pole [9] [10] table 1.
Negative pole [9] [10] table 1
[table 52]
Figure BDA0000087738240003181
Negative pole [9] [10] [making of battery]
" anodal making 1 "
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of positive electrode active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of the positive electrode active material layer of the positive pole of this moment is 2.35g/cm 3
" making 1 of negative pole "
In 98 weight portion negative electrode active materials, add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the rolled copper foil two sides of thickness 10 μ m; And it is dry; Roll into thickness 75 μ m with press, be cut into again have wide 104mm, the shape of the uncoated part of the negative electrode active material layer of long 104mm size and wide 30mm, as negative pole.
The density of the negative electrode active material layer of the negative pole of this moment is 1.33～1.36g/cm 3Scope (being shown in the rightest hurdle of negative pole [9] [10] table 2 respectively).From the above, be 1 quality % as the SBR styrene butadiene rubbers of adhesive with respect to the content of whole negative electrode active material layer in the negative electrode active material layer.In addition, the value of [(thickness of the negative electrode active material layer of one side)/(thickness of collector body)] is 75 μ m/10 μ m=7.5.
" making 1 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the difluorophosphoric acid lithium salts (LiPO that also contains 0.3 quality % 2F 2).
" making 2 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the methanesulfonic acid trimethyl silyl ester that also contains 0.3 quality %.
" making 3 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).In addition, the hexamethyl cyclotrisiloxane that also contains 0.3 quality %.
" making 4 of nonaqueous electrolytic solution "
Under the argon atmosphere of drying, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC), dissolve the lithium hexafluoro phosphate (LiPF of intensive drying with the concentration of 1mol/L 6).
" making 1 of battery "
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.The specified discharge capacity of this battery is about 6 ampere-hours (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms (m Ω).The ratio of the summation that the summation of anodal electrode area is long-pending with respect to the case surface of battery is 20.6.
Negative pole [9] [10] embodiment 1
Use the nonaqueous electrolytic solution of making in anodal and " making 1 of nonaqueous electrolytic solution " made in the negative pole that the negative electrode active material of " making 1 of negative pole " makes as carbonaceous material (A), " anodal making 1 ", through the method manufacture batteries in " making 1 of battery " item.Method described in following " evaluation of battery " item is measured this battery.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] embodiment 2
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 1 changes the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 1.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] embodiment 3
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 1 changes the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 1.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] comparative example 1
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 1 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 1.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] embodiment 4
Except the negative electrode active material of negative pole [9] [10] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (B),, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 1.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] embodiment 5
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 4 changes the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 4.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] embodiment 6
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 4 changes the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 4.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] comparative example 2
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 4 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 4.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] embodiment 7
Except the negative electrode active material of negative pole [9] [10] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (C),, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 1.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] embodiment 8
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 7 changes the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 7.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] embodiment 9
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 7 changes the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 7.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] comparative example 3
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 7 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 7.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] embodiment 10
Except the negative electrode active material of negative pole [9] [10] embodiment 1 " making 1 of negative pole " uses the carbonaceous material (D),, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 1.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] embodiment 11
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 10 changes the nonaqueous electrolytic solution of making in " making 2 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 10.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] embodiment 12
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 10 changes the nonaqueous electrolytic solution of making in " making 3 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 10.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] comparative example 4
Except the nonaqueous electrolytic solution with negative pole [9] [10] embodiment 10 changes the nonaqueous electrolytic solution of making in " making 4 of nonaqueous electrolytic solution " into,, and likewise estimate according to the method manufacture batteries same with negative pole [9] [10] embodiment 10.The result is shown in negative pole [9] [10] table 2.
Negative pole [9] [10] " evaluation of battery "
(solid measure)
To battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.2V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.With the 0.2C discharge capacity of the 5th circulation of this moment as initial capacity.Then carry out the output test shown in following.
(output test)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as power output (W).With the power output before the cyclic test as " initial stage power output ".
(cyclic test)
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.Charge to charging upper voltage limit 4.2V with the constant-current constant-voltage method of 2C, the constant current with 2C is discharged to final discharging voltage 3.0V then, and this charge and discharge cycles as 1 circulation, and is carried out this circulation repeatedly and circulated until 500.Battery after finishing for cyclic test carries out discharging and recharging of 3 circulations under 25 ℃ of environment, with the 0.2C discharge capacity of the 3rd circulation as circulation back capacity.Obtain the circulation conservation rate by capacity after the circulation of initial capacity of measuring before the cyclic test and cyclic test end back mensuration according to following calculating formula.
Circulation conservation rate (%)=100 * circulation back capacity/initial capacity
Impedance Rct and double-deck capacity C dl in negative pole [9] [10] table 2 are to one of contributive parameter of power output, and the value of impedance Rct is more little, and perhaps the value of double-deck capacity C dl is big more, and then power output has the tendency of improvement more.In addition, " impedance Rct " and " double-deck capacity C dl " obtains through the method put down in writing of part of explanation impedance.
Carry out the output test described in above-mentioned (output test) item for the battery after the cyclic test end, and the value that will obtain is as " power output after the cyclic test ".The reaction resistance of obtaining in the output test result of the lithium secondary battery of above-mentioned negative pole [9] [10] embodiment and negative pole [9] [10] comparative example, solid measure result, circulation conservation rate and the above-mentioned opposed impedance measuring and the mensuration result of double-deck capacity conclude and are shown in negative pole [9] [10] table 2.
Negative pole [9] [10] table 2
[table 53]
Result by negative pole [9] [10] table 2 can know; Through in nonaqueous electrolytic solution, containing specific compounds such as difluorophosphoric acid lithium salts, methanesulfonic acid trimethyl silyl ester, hexamethyl cyclotrisiloxane; And be the negative electrode active material more than the 0.01mL/g through in negative pole, to contain tap density be more than 0.1 and adopt the micropore volume of 0.01 μ m～1 mu m range that the mercury porosimeter measures; Even for large-scale battery; Also can realize power output and high circulation conservation rate after the high circulation, thereby the lithium secondary battery with high-output power and long-life can be provided.
In addition; Through in nonaqueous electrolytic solution, containing specific compound; And the reaction resistance that the opposed battery that makes negative pole produces is below 500 Ω; Even for large-scale battery, also can realize power output and high circulation conservation rate after the high circulation, thereby have both high-output power and good life-span.
Electrolyte [1] < making of secondary cell >
[anodal making]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.
[making of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the two sides of the Copper Foil of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.
[assembling of battery]
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.The specified discharge capacity of this battery is about 6 ampere-hours (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms.
[evaluation of battery]
(assay method of initial capacity)
To the new battery without charge and discharge cycles, the initial stage of carrying out 5 circulations at 25 ℃, the voltage range of 4.1V～3.0V discharges and recharges (voltage range 4.1V～3.0V).With the 0.2C of the 5th circulation of this moment (as 1C, said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate) with the current value of 1 hour discharge rated capacity, down with) discharge capacity as initial capacity.
(assay method of low temperature power output)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, under-30 ℃ of environment, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 5.0C respectively, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as power output (W).
Electrolyte [1] embodiment 1
Under dry argon atmosphere, in the mixture (volume ratio 15: 85) of ethylene carbonate (EC), methyl ethyl carbonate (EMC), add lithium hexafluoro phosphate (LiPF with 1mol/L 6) and dissolve, in this mixed solution, mix the hexamethyl cyclotrisiloxane of the amount of 0.3 quality %, the preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution manufacture batteries according to the method described above, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] embodiment 2
Use among electrolyte [1] embodiment 1 nonaqueous electrolytic solution to come manufacture batteries with the volume ratio preparation in 20: 80 of EC and EMC, and mensuration low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] embodiment 3
Use nonaqueous solvents among electrolyte [1] embodiment 1 to change to the mixture (volume ratio 15: 40: 45) of EC, dimethyl carbonate (DMC), EMC and the nonaqueous electrolytic solution of preparation comes manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] embodiment 4
Use is mixed with that phenyl dimethyl silicon fluoride comes the hexamethyl cyclotrisiloxane among alternative electrolyte [1] embodiment 1 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] embodiment 5
Use is mixed with that HMDO comes the hexamethyl cyclotrisiloxane among alternative electrolyte [1] embodiment 1 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] embodiment 6
Use is mixed with that methanesulfonic acid trimethyl silyl ester comes the hexamethyl cyclotrisiloxane among alternative electrolyte [1] embodiment 1 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] embodiment 7
Use is mixed with that methyl fluorosulfonate comes the hexamethyl cyclotrisiloxane among alternative electrolyte [1] embodiment 1 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] embodiment 8
Use is mixed with lithium nitrate and comes the hexamethyl cyclotrisiloxane among alternative electrolyte [1] embodiment 1 and preserved 3 days and the nonaqueous electrolytic solution that obtains comes manufacture batteries, and measures the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] embodiment 9
Use is mixed with according to Inorganic Nuclear Chemistry Letters (1969); In the 581st page～the 582nd page of 5 (7) difluorophosphate of the method preparation of record come the hexamethyl cyclotrisiloxane among alternative electrolyte [1] embodiment 1 and the nonaqueous electrolytic solution for preparing as nonaqueous electrolytic solution; Manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] embodiment 10
Among electrolyte [1] embodiment 9, using combined amount with difluorophosphate to change to mixed solution with respect to nonaqueous solvents and lithium hexafluoro phosphate is that the nonaqueous electrolytic solution that the amount of 0.08 quality % obtains comes manufacture batteries, and mensuration low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] embodiment 11
Use is mixed with lithium acetate and comes the hexamethyl cyclotrisiloxane among alternative electrolyte [1] embodiment 1 and preserved 3 days and the nonaqueous electrolytic solution that obtains, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] embodiment 12
< making of secondary cell-2 >
[anodal making]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 20 μ m, and dry, rolls into thickness 80 μ m, be cut into wide 52mm again, long 830mm is big or small, as positive pole with press.Wherein, the surperficial back side all is provided with the uncoated part of 50mm in the longitudinal direction, and the length of active material layer is 780mm.
[making of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is uniformly coated on the two sides as the Copper Foil of the thickness 18 μ m of negative electrode collector, and after the drying, using press to roll into thickness is 85 μ m, is cut into the size of wide 56mm, long 850mm again, as negative pole.Wherein, the surperficial back side all is provided with the uncoated part of 30mm in the longitudinal direction.
[making of electrolyte]
Make the nonaqueous electrolytic solution same with electrolyte [1] embodiment 1.
[assembling of battery]
With anodal and negative pole with the overlapping coiling of the dividing plate of polyethylene system so that positive pole does not directly contact with negative pole, process electrode body.The terminal of anodal and negative pole is exposed externally to be contained in the battery can.
Then, behind the electrolyte of after wherein injecting 5mL, stating, carry out riveting molding, make 18650 type cylinder batteries.The specified discharge capacity of this battery is about 0.7 ampere-hour (Ah), and the D.C. resistance of measuring with the 10kHz alternating current method is about 35 milliohms (m Ω).In addition, the summation of the electrode area of above-mentioned positive pole is 19.4 times with respect to the area ratio of the surface area of the shell of this secondary cell.For above-mentioned battery, likewise measure the low temperature power output with electrolyte [1] embodiment 1.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 1
Use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane among electrolyte [1] embodiment 1 and prepare to come manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 2
Use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane among electrolyte [1] embodiment 2 and prepare to come manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 3
Use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane among electrolyte [1] embodiment 3 and prepare to come manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 4
Under dry argon atmosphere, in the mixture (volume ratio 4: 6) of ethylene carbonate and methyl ethyl carbonate, add lithium hexafluoro phosphate (LiPF with 1mol/L 6) and dissolve, again being that the amount of 0.3 quality % is mixed hexamethyl cyclotrisiloxane and prepared nonaqueous electrolytic solution with respect to this mixed solution.
Use this nonaqueous electrolytic solution manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 5
Use is mixed with that phenyl dimethyl silicon fluoride comes the hexamethyl cyclotrisiloxane in alternative electrolyte [1] comparative example 4 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 6
Use is mixed with that HMDO comes the hexamethyl cyclotrisiloxane in alternative electrolyte [1] comparative example 4 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 7
Use is mixed with that methanesulfonic acid trimethyl silyl ester comes the hexamethyl cyclotrisiloxane in alternative electrolyte [1] comparative example 4 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 8
Use is mixed with that methyl fluorosulfonate comes the hexamethyl cyclotrisiloxane in alternative electrolyte [1] comparative example 4 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 9
Use is mixed with lithium nitrate and comes the hexamethyl cyclotrisiloxane in alternative electrolyte [1] comparative example 4 and preserved 3 days and the nonaqueous electrolytic solution that obtains, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 10
Use is mixed with that difluorophosphate comes the hexamethyl cyclotrisiloxane in alternative electrolyte [1] comparative example 4 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 11
Use is mixed with lithium acetate and comes the hexamethyl cyclotrisiloxane in alternative electrolyte [1] comparative example 4 and preserved 3 days and the nonaqueous electrolytic solution that obtains, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 12
Use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane in electrolyte [1] comparative example 4 and prepare, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] comparative example 13
Among electrolyte [1] embodiment 12, use the nonaqueous electrolytic solution same with electrolyte [1] comparative example 1, manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [1] table 1.
Electrolyte [1] table 1
[table 54]
Figure BDA0000087738240003291
Can know by electrolyte [1] table 1; The lithium secondary battery that in nonaqueous electrolytic solution, contains the EC of specified quantitative and the electrolyte of specific compound [1] embodiment 1～11; Not only compare with the lithium secondary battery that contains excessive EC and do not contain electrolyte [1] comparative example 12 of specific compound; Though even with EC amount in particular range but the electrolyte [1] that does not contain specific compound though comparative example 1～3 and the lithium secondary battery that contains the excessive electrolyte of specific compound EC [1] comparative example 4～11 are compared, the low temperature characteristics of output power improves.In addition; The lithium secondary battery that in nonaqueous electrolytic solution, contains the EC of specified quantitative and the electrolyte of specific compound [1] embodiment 12; Do not compare though in particular range, still do not contain the lithium secondary battery of electrolyte [1] comparative example 13 of specific compound with the EC amount, the low temperature characteristics of output power improves.
In addition, this effect is not both simple stacks, and through satisfying two aspect conditions, effect obviously strengthens.Put down in writing when using the nonaqueous electrolytic solution that contains specific compound (in addition being same composition) climbing of the low temperature power output when using the nonaqueous electrolytic solution that does not contain specific compound in electrolyte [1] table 1; Compare with excessive electrolyte [1] comparative example 4～11 of EC amount; Among electrolyte [1] embodiment 1～12; This value is big, and effect of the present invention is big.
In addition; Electrolyte [1] embodiment 12 is 20.8% with respect to the power output climbing of electrolyte [1] comparative example 13; And though but to use different electrolyte [1] embodiment 1 of same material battery structure be 26.4% with respect to the power output climbing of electrolyte [1] comparative example 1, can know battery structure the effect of nonaqueous electrolytic solution of the present invention is had big influence.That is, for the little battery of battery, the D.C. resistance of high power capacity, effect of the present invention is big especially.
Further, though record in the table when being to use EC content less than the electrolyte of 1 capacity %, is compared with electrolyte [1] embodiment 1, initial capacity reduces a little, characteristics of output power under the normal temperature or cycle characteristics variation.
As stated; The nonaqueous electrolytic solution of the application of the invention; The secondary cell that promptly has following characteristics is used nonaqueous electrolytic solution; Can bring into play very large low temperature characteristics of output power; Said secondary cell is characterized as with nonaqueous electrolytic solution: it is for contain the mixed solvent of ethylene carbonate at least, and ethylene carbonate is 1 capacity %～25 capacity % for the ratio of nonaqueous solvents total amount, and this nonaqueous electrolytic solution also contains at least a compound that is selected from the following substances; And its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises: the compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that have the S-F key in the fluorosilane compounds of the cyclic siloxane compound of general formula (1) expression, general formula (2) expression, the compound of general formula (3) expression, the molecule.
In addition, compare,, in the battery that promptly battery of high power capacity, D.C. resistance are little, can bring into play this effect more significantly at the battery structure of electrolyte [1] embodiment 1 with the battery structure of electrolyte [1] embodiment 12.
Electrolyte [2] < making of secondary cell-1 >
[anodal making]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 20 μ m, and dry, rolls into thickness 80 μ m, be cut into wide 52mm again, long 830mm is big or small, as positive pole with press.Wherein, the surperficial back side all is provided with the uncoated part of 50mm in the longitudinal direction, and the length of active material layer is 780mm.
[making of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is uniformly coated on the two sides as the Copper Foil of the thickness 18 μ m of negative electrode collector, and after the drying, using press to roll into thickness is 85 μ m, is cut into the size of wide 56mm, long 850mm again, as negative pole.Wherein, the surperficial back side all is provided with the uncoated part of 30mm in the longitudinal direction.
[assembling of battery]
With anodal and negative pole with the overlapping coiling of the dividing plate of polyethylene system so that positive pole does not directly contact with negative pole, process electrode body.The terminal of anodal and negative pole is exposed externally to be contained in the battery can.Then, behind the electrolyte of after wherein injecting 5mL, stating, carry out riveting molding, make 18650 type cylinder batteries.The electric capacity that the battery key element that 1 battery case of secondary cell is taken in is had, promptly the specified discharge capacity of secondary cell is about 0.7 ampere-hour (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 35 milliohms (m Ω).
[evaluation of battery]
(initial stage discharges and recharges)
To the battery of making, 25 ℃ charge to 4.2V with the constant-current constant-voltage mise-a-la-masse methods of 0.2C down after, be discharged to 3.0V with the constant current of 0.2C.It is carried out 5 circulations makes battery stable.With the discharge capacity of the 5th circulation of this moment as initial capacity.And, with 1 hour the discharge rated capacity current value as 1C, said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate).
(cyclic test)
The battery that the initial stage of having implemented is discharged and recharged is carrying out being discharged to 500 circulations that discharge and recharge of 3.0V again with the constant current of 1C after constant-current constant-voltage with 1C charges to 4.2V under 60 ℃.With the 500th cyclic discharge capacity of this moment with respect to the ratio of the 1st cyclic discharge capacity as the circulation conservation rate.
(low-temperature test)
The battery that the initial stage of having implemented is discharged and recharged, 25 ℃ charge to 4.2V with the constant-current constant-voltage mise-a-la-masse methods of 0.2C down after, discharge at-30 ℃ of constant currents of implementing 0.2C down.With the discharge capacity of this moment as initial stage low temperature capacity, with initial stage low temperature capacity with respect to the ratio of initial capacity as initial stage low temperature discharge rate.
In addition, to the battery after the cyclic test 25 ℃ down charge to 4.2V with the constant-current constant-voltage mise-a-la-masse methods of 0.2C after, be discharged to 3.0V with the constant current of 0.2C.It is carried out 3 circulations, with the discharge capacity of its 3rd circulation as circulation back capacity.Then, to same battery after charging to 4.2V with the constant-current constant-voltage mise-a-la-masse method of 0.2C under 25 ℃ ,-30 ℃ of constant currents discharges of implementing 0.2C down.With the discharge capacity of this moment as circulation back low temperature capacity, with circulation back low temperature capacity with respect to the ratio of circulation back capacity as circulation back low temperature discharge rate.
Electrolyte [2] embodiment 1
Under dry argon atmosphere, in the mixture (volume ratio 2: 4: 4) of ethylene carbonate (EC), methyl ethyl carbonate (EMC) and diethyl carbonate (DEC), add lithium hexafluoro phosphate (LiPF with 0.9mol/L 6) and dissolve, make contain in this mixed solution 0.3 quality % according to Inorganic Nuclear Chemistry Letters (1969), the difluorophosphate of the method preparation of record in the 581st page～the 582nd page of 5 (7), preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution to make 18650 type cylinder batteries, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [2] table 1.And with reclaiming electrolyte the battery after the low temperature solid measure of centrifugal separator after circulation, when through gas-chromatography (GC) amount of the dimethyl carbonate (DMC) that generates in the ester exchange reaction being analyzed, its amount is 0.5 quality % in the electrolyte.
Electrolyte [2] comparative example 1
Except not containing the difluorophosphate, likewise make 18650 type cylinder batteries with electrolyte [2] embodiment 1, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [2] table 1.And with reclaiming electrolyte the battery after the low temperature solid measure of centrifugal separator after circulation, when through gas-chromatography (GC) amount of the dimethyl carbonate (DMC) that generates in the ester exchange reaction being analyzed, its amount is 9.7 quality % in the electrolyte.
Electrolyte [2] comparative example 2
Under dry argon atmosphere, in the mixture (volume ratio 2: 8) of ethylene carbonate (EC) and diethyl carbonate (DEC), add lithium hexafluoro phosphate (LiPF with 0.9mol/L 6) and dissolve, make the difluorophosphate that contains 0.3 quality % in this mixed solution, the preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution to make 18650 type cylinder batteries, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [2] table 1.
Electrolyte [2] embodiment 2
Except using carbonic acid methyl n-pro-pyl ester to come the alternative methyl ethyl carbonate, likewise make 18650 type cylinder batteries with electrolyte [2] embodiment 1, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [2] table 1.
Electrolyte [2] comparative example 3
Except not containing the difluorophosphate, likewise make 18650 type cylinder batteries with electrolyte [2] embodiment 2, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [2] table 1.
Electrolyte [2] < making of secondary cell-2 >
< anodal making >
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.
< making of negative pole >
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose be 1 quality %) of 100 weight portions in as the sodium carboxymethylcellulose of thickener; 2 weight portions are as the aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) of the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.
< assembling of battery >
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.The electric capacity that the battery key element of taking in 1 battery case of secondary cell has, promptly the specified discharge capacity of secondary cell is about 6 ampere-hours (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms (m Ω).
Electrolyte [2] embodiment 3
Use the electrolyte that uses among electrolyte [2] embodiment 1 to make rectangular cell, and employing implement cyclic test, low-temperature test with electrolyte [2] embodiment 1 identical method, and mensuration circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [2] table 1.
Electrolyte [2] comparative example 4
Use the electrolyte that uses in electrolyte [2] comparative example 1 to make rectangular cell, implement cyclic test, low-temperature test, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [2] table 1.
Electrolyte [2] comparative example 5
Use the electrolyte that uses in electrolyte [2] comparative example 2 to make rectangular cell, implement cyclic test, low-temperature test, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [2] table 1.
Electrolyte [2] table 1
[table 55]
Figure BDA0000087738240003341
Can know by electrolyte [2] table 1; If to each cylinder battery (electrolyte [2] embodiment 1,2; Electrolyte [2] comparative example 1～3), rectangular cell (electrolyte [2] embodiment 3; Electrolyte [2] comparative example 4,5) compares; The lithium secondary battery that then contains electrolyte [2] embodiment of asymmetric linear carbonate and difluorophosphoric acid salt in the nonaqueous electrolytic solution is simultaneously compared with the lithium secondary battery that does not contain these any one electrolyte [2] comparative example, and circulation conservation rate, low temperature discharge rate all improve.
As stated, the specified discharge capacity of the cylinder battery of present embodiment and this comparative example is less than 3 ampere-hours (Ah), and DC resistance component is greater than 10 milliohms (m Ω).On the other hand, the specified discharge capacity of the rectangular cell of present embodiment and this comparative example is more than 3 ampere-hours (Ah), and DC resistance component is below 10 milliohms (m Ω).That is, the rectangular cell of present embodiment, this comparative example is compared with the cylinder battery, and resistance is little, and electric capacity is big.And; Compare with respect to the low-temperature characteristics raising degree of electrolyte [2] comparative example 1 with electrolyte [2] embodiment 1; Electrolyte [2] embodiment 3 is big with respect to the low-temperature characteristics raising degree of electrolyte [2] comparative example 4; In the little secondary cell of the big secondary cell of electric capacity or D.C. resistance, effect of the present invention is bigger.
Electrolyte [3] < manufacturing of secondary cell-1 >
[anodal manufacturing]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.
[manufacturing of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.
[assembling of battery]
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).
Then, in the battery can that the electrode group is housed, inject the nonaqueous electrolytic solution of 20mL following electrolyte [3] embodiment and electrolyte [3] comparative example, electrode is fully soaked into, seal and the making rectangular cell.The specified discharge capacity of this battery is about 6 ampere-hours (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms (m Ω).In addition, the summation of the electrode area of above-mentioned positive pole is 20.65 times with respect to the area ratio of the surface area of the shell of this secondary cell.
[evaluation of battery]
(solid measure)
To without the new battery that discharges and recharges, the initial stage of carrying out 5 circulations at 25 ℃, the voltage range of 4.1V～3.0V discharges and recharges (voltage range 4.1V～3.0V).With the 0.2C of the 5th circulation of this moment (as 1C, said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate) with the current value of 1 hour discharge rated capacity, down with) discharge capacity as initial capacity.
(output test)
Constant current with 0.2C under 25 ℃ of environment carries out charging in 150 minutes, under-30 ℃ of environment, discharges 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 5.0C respectively, measures the 10th second voltage.The leg-of-mutton area that will be surrounded by current-voltage straight line and lower voltage limit (3V) is as power output (W).
Electrolyte [3] embodiment 1
Under dry argon atmosphere, in the mixture (volume ratio 3: 6: 1) of ethylene carbonate (EC), methyl ethyl carbonate (EMC) and methyl propionate (MP), add lithium hexafluoro phosphate (LiPF with 1mol/L 6) and dissolve, in this mixed solution, mix the hexamethyl cyclotrisiloxane of the amount of 0.3 quality % then, the preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution to use the said method manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 2
The nonaqueous electrolytic solution that uses ethyl acetate (EA) with equivalent to come the methyl propionate among alternative electrolyte [3] embodiment 1 and prepare comes manufacture batteries, and mensuration low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 3
The nonaqueous electrolytic solution that uses methyl acetate (MA) with equivalent to come the methyl propionate among alternative electrolyte [3] embodiment 1 and prepare comes manufacture batteries, and mensuration low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 4
Under dry argon atmosphere, to the mixture (volume ratio 30: 60: 5: add lithium hexafluoro phosphate (LiPF with 1mol/L 5) of ethylene carbonate (EC), methyl ethyl carbonate (EMC), methyl propionate (MP) and methyl acetate (MA) 6) and dissolve, in this mixed solution, mix the hexamethyl cyclotrisiloxane of the amount of 0.3 quality % then, the preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution to use the said method manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 5
The nonaqueous electrolytic solution that uses among electrolyte [3] embodiment 1 volume ratio with the mixture of ethylene carbonate (EC), methyl ethyl carbonate (EMC) and methyl propionate (MP) to change to 3: 4: 3 and prepare, the low temperature of manufacture batteries, and mensuration according to the method described above power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 6
Under dry argon atmosphere, in the mixture (volume ratio 3: 7) of ethylene carbonate (EC) and methyl propionate (MP), add lithium hexafluoro phosphate (LiPF with 1mol/L 6) and dissolve, in this mixed solution, mix the hexamethyl cyclotrisiloxane of the amount of 0.3 quality % then, the preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution to use the said method manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 7
The phenyl dimethyl silicon fluoride that uses equivalent volumes comes the hexamethyl cyclotrisiloxane among alternative electrolyte [3] embodiment 1 and the nonaqueous electrolytic solution that obtains comes manufacture batteries as nonaqueous electrolytic solution, and measures the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 8
The pregnancy basic ring disiloxane that uses equivalent volumes comes the hexamethyl cyclotrisiloxane among alternative electrolyte [3] embodiment 1 and the nonaqueous electrolytic solution that obtains comes manufacture batteries as nonaqueous electrolytic solution, and measures the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 9
The methanesulfonic acid trimethyl silyl ester that uses equivalent volumes comes the hexamethyl cyclotrisiloxane among alternative electrolyte [3] embodiment 1 and the nonaqueous electrolytic solution that obtains comes manufacture batteries as nonaqueous electrolytic solution, and measures the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 10
The methyl fluorosulfonate that uses equivalent volumes comes the hexamethyl cyclotrisiloxane among alternative electrolyte [3] embodiment 1 and the nonaqueous electrolytic solution that obtains comes manufacture batteries as nonaqueous electrolytic solution, and measures the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 11
Use the lithium nitrate of equivalent volumes to come the hexamethyl cyclotrisiloxane among alternative electrolyte [3] embodiment 1 and preserved 3 days and the nonaqueous electrolytic solution that obtains comes manufacture batteries as nonaqueous electrolytic solution, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 12
Use equivalent volumes (mixed solution with respect to nonaqueous solvents and lithium hexafluoro phosphate is the amount of 0.3 quality %) according to Inorganic Nuclear Chemistry Letters (1969); In the 581st page～the 582nd page of 5 (7) difluorophosphate of the method preparation of record come the hexamethyl cyclotrisiloxane among alternative electrolyte [3] embodiment 1 and the nonaqueous electrolytic solution for preparing as nonaqueous electrolytic solution; Manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 13
Using the combined amount of the difluorophosphate among electrolyte [3] embodiment 12 to change to mixed solution with respect to nonaqueous solvents and lithium hexafluoro phosphate is the nonaqueous electrolytic solution that the amount of 0.08 quality % prepares, manufacture batteries, and mensuration low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] embodiment 14
< making of secondary cell-2 >
< anodal making >
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 20 μ m, and dry, rolls into thickness 80 μ m, be cut into wide 52mm again, long 830mm is big or small, as positive pole with press.Wherein, the surperficial back side all is provided with the uncoated part of 50mm in the longitudinal direction, and the length of active material layer is 780mm.
< making of negative pole >
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is uniformly coated on the two sides as the Copper Foil of the thickness 18 μ m of negative electrode collector, and after the drying, using press to roll into thickness is 85 μ m, is cut into the size of wide 56mm, long 850mm again, as negative pole.Wherein, the surperficial back side all is provided with the uncoated part of 30mm in the longitudinal direction.
[preparation of electrolyte]
The nonaqueous electrolytic solution that preparation is identical with electrolyte [3] embodiment 1.
[assembling of battery]
Directly do not contact with negative pole with overlapping coiling of the dividing plate of polyethylene system and feasible positive pole with negative pole anodal, process electrode body.The terminal of anodal and negative pole is exposed externally to be accommodated in the battery can.Then, behind the electrolyte of after wherein injecting 5mL, stating, carry out riveting molding, make 18650 type cylinder batteries.The specified discharge capacity of this battery is about 0.7Ah, and the D.C. resistance of measuring with the 10kHz alternating current method is about 35 milliohms (m Ω).In addition, the summation of the electrode area of above-mentioned positive pole is 19.4 times with respect to the area ratio of the surface area of the shell of this secondary cell.In the above-mentioned battery, likewise measure the low temperature power output with electrolyte [3] embodiment 1.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 1
Use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane among electrolyte [3] embodiment 1 and prepare, use the said method manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 2
Use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane among electrolyte [3] embodiment 2 and prepare, use the said method manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 3
Use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane among electrolyte [3] embodiment 3 and prepare, use the said method manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 4
Use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane among electrolyte [3] embodiment 4 and prepare, use the said method manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 5
Use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane among electrolyte [3] embodiment 5 and prepare, use the said method manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 6
Under dry argon atmosphere, in the mixture (volume ratio 3: 7) of ethylene carbonate and methyl ethyl carbonate, add lithium hexafluoro phosphate (LiPF with 1mol/L 6) and dissolve the preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution to use the said method manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 7
Under dry argon atmosphere, in the mixture (volume ratio 3: 7) of ethylene carbonate and methyl ethyl carbonate, add lithium hexafluoro phosphate (LiPF with 1mol/L 6) and dissolve, in this mixed solution, mix the hexamethyl cyclotrisiloxane of the amount of 0.3 quality % then, the preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution to use the said method manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 8
The phenyl dimethyl silicon fluoride that uses equivalent volumes come the hexamethyl cyclotrisiloxane in alternative electrolyte [3] comparative example 7 and the nonaqueous electrolytic solution that obtains as nonaqueous electrolytic solution, use the said method manufacture batteries, and mensuration low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 9
The pregnancy basic ring disiloxane that uses equivalent volumes come the hexamethyl cyclotrisiloxane in alternative electrolyte [3] comparative example 7 and the nonaqueous electrolytic solution that obtains as nonaqueous electrolytic solution, use the said method manufacture batteries, and mensuration low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 10
The methanesulfonic acid trimethyl silyl ester that uses equivalent volumes come the hexamethyl cyclotrisiloxane in alternative electrolyte [3] comparative example 7 and the nonaqueous electrolytic solution that obtains as nonaqueous electrolytic solution, use the said method manufacture batteries, and mensuration low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 11
The methyl fluorosulfonate that uses equivalent volumes come the hexamethyl cyclotrisiloxane in alternative electrolyte [3] comparative example 7 and the nonaqueous electrolytic solution that obtains as nonaqueous electrolytic solution, use the said method manufacture batteries, and mensuration low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 12
Use the lithium nitrate of equivalent volumes to come the hexamethyl cyclotrisiloxane in alternative electrolyte [3] comparative example 7 and preserved 3 days and the nonaqueous electrolytic solution that obtains as nonaqueous electrolytic solution, use the said method manufacture batteries, and mensuration low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 13
The difluorophosphate that uses equivalent volumes come the hexamethyl cyclotrisiloxane in alternative electrolyte [3] comparative example 7 and the nonaqueous electrolytic solution that obtains as nonaqueous electrolytic solution, use the said method manufacture batteries, and mensuration low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] comparative example 14
Among electrolyte [3] embodiment 14, use the nonaqueous electrolytic solution that likewise prepares with electrolyte [3] comparative example 1, use the said method manufacture batteries, and measure the low temperature power output.The result is shown in electrolyte [3] table 1.
Electrolyte [3] table 1
[table 56]
Can know by electrolyte [3] table 1; The lithium secondary battery that in nonaqueous electrolytic solution, contains electrolyte [3] embodiment 1～13 of chain carboxylate and specific compound; Not only compare with the lithium secondary battery that does not contain wherein any electrolyte [3] comparative example 6; Even compare with the electrolyte that does not contain specific compound [3] comparative example 1～5, the lithium secondary battery that do not contain electrolyte [3] comparative example 7～13 of chain carboxylate, the low temperature characteristics of output power also improves.In addition, this effect is not both simple stacks, and through using both, effect obviously strengthens.
In addition; Electrolyte [3] embodiment 14 is about 21% with respect to the power output climbing of electrolyte [3] comparative example 14; And use different electrolyte [3] embodiment 1 of identical materials, battery structure to be about 29% for the power output climbing of electrolyte [3] comparative example 1, can know that battery structure is influential to the effect size of nonaqueous electrolytic solution of the present invention.
As stated; The nonaqueous electrolytic solution of the application of the invention; The secondary cell that promptly has following characteristics is used nonaqueous electrolytic solution; Can bring into play very large low temperature characteristics of output power; Said secondary cell with the characteristic of nonaqueous electrolytic solution is: contain at least a above chain carboxylate; Also contain at least a compound that is selected from the following substances, and its content in whole nonaqueous electrolytic solutions is more than the 10ppm, said material comprises: the compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that have the S-F key in the fluorosilane compounds of the cyclic siloxane compound of general formula (1) expression, general formula (2) expression, the compound of general formula (3) expression, the molecule.
Electrolyte [4] < making of secondary cell-1 (manufacturing of rectangular cell) >
[anodal making]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.
[making of negative pole]
2kg Delanium powder KS-44 (timcal manufactured, trade name) and 1kg petroleum-type pitch are mixed, the mixture of the pulpous state that obtains is heated up 2 hours until 1100 ℃ in batch kiln in inactive atmosphere under, maintenance is 2 hours under this temperature.
With its pulverizing, through the oscillatory type sieve particle diameter is adjusted into 18～22 μ m, finally obtain covering " the amorphous coated graphite class carbonaceous material " of graphite surface with the amorphous carbon of 7 quality %.Originally " amorphous coated graphite class carbonaceous material " is as negative electrode active material; In 98 weight portions " amorphous coated graphite class carbonaceous material ", add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.
[assembling of battery]
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in the battery can (external dimensions: in 120 * 110 * 10mm) that has dump valve.Then, in the battery can that the electrode group is housed, inject the nonaqueous electrolytic solution of stating behind the 20mL, electrode is fully soaked into, seal and the making rectangular cell.The electric capacity that the battery key element of taking in 1 battery case of secondary cell is had, promptly the specified discharge capacity of this battery is about 6Ah, and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms.
" evaluation of battery "
(solid measure)
To battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.2V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.With the 0.2C discharge capacity of the 5th circulation of this moment as initial capacity.
(output test)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as power output (W).
Electrolyte [4] embodiment 1
143 ℃ of flash-points), gamma-butyrolacton (GBL: 101 ℃ of flash-points) and diethyl carbonate (DEC: the LiPF that adds 0.3mol/L in the mixture 25 ℃ of flash-points) (Capacity Ratio 2: 7: 1) under dry argon atmosphere, to ethylene carbonate (EC: 6LiBF with 0.7mol/L 4, and dissolve, make the vinylene carbonate that contains 1 quality % in this mixed solution, the hexamethyl cyclotrisiloxane of 0.3 quality %, the preparation nonaqueous electrolytic solution.The flash-point of this nonaqueous electrolytic solution is 61 ℃.Use this nonaqueous electrolytic solution to make rectangular cell, and measure power output with said method.The result is shown in electrolyte [4] table 1.
Electrolyte [4] embodiment 2
Process the nonaqueous electrolytic solution except using phenyl dimethyl silicon fluoride to substitute hexamethyl cyclotrisiloxane, likewise make rectangular cell with electrolyte [4] embodiment 1, and measure power output.The result is shown in electrolyte [4] table 1.
Electrolyte [4] embodiment 3
Process the nonaqueous electrolytic solution except using methyl fluorosulfonate to substitute hexamethyl cyclotrisiloxane, likewise make rectangular cell, and measure power output with electrolyte [4] embodiment 1.The result is shown in electrolyte [4] table 1.
Electrolyte [4] embodiment 4
Except using according to Inorganic Nuclear Chemistry Letters (1969); The difluorophosphate that the method for record prepares in the 581st page～the 582nd page of 5 (7) substitutes hexamethyl cyclotrisiloxane and processes beyond the nonaqueous electrolytic solution; Likewise make rectangular cell with electrolyte [4] embodiment 1, and measure power output.The result is shown in electrolyte [4] table 1.
Electrolyte [4] comparative example 1
Except nonaqueous electrolytic solution is not contained the hexamethyl cyclotrisiloxane, likewise make rectangular cell with electrolyte [4] embodiment 1, and measure power output.The result is shown in electrolyte [4] table 1.
Electrolyte [4] < manufacturing of secondary cell-2 (making of cylinder battery) >
[anodal manufacturing]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 20 μ m, and dry, rolls into thickness 80 μ m, be cut into wide 52mm again, long 830mm is big or small, as positive pole with press.Wherein, the surperficial back side all is provided with the uncoated part of 50mm in the longitudinal direction, and the length of active material layer is 780mm.
[manufacturing of negative pole]
2kg Delanium powder KS-44 (timcal manufactured, trade name) and 1kg petroleum-type pitch are mixed, the mixture of the pulpous state that obtains is heated up 2 hours until 1100 ℃ in batch kiln in inactive atmosphere under, maintenance is 2 hours under this temperature.
With its pulverizing, through the oscillatory type sieve particle diameter is adjusted into 18～22 μ m, finally obtain covering " the amorphous coated graphite class carbonaceous material " of graphite surface with the amorphous carbon of 7 quality %.Originally " amorphous coated graphite class carbonaceous material " is as negative electrode active material; In 98 weight portions " amorphous coated graphite class carbonaceous material ", add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the two sides as the Copper Foil of the thickness 18 μ m of negative electrode collector, and dry, and using press to roll into thickness is 85 μ m, is cut into the size of wide 56mm, long 850mm again, as negative pole.Wherein, the surperficial back side all is provided with the uncoated part of 30mm in the longitudinal direction.
[assembling of battery]
Directly do not contact with negative pole with overlapping coiling of the dividing plate of polyethylene system and feasible positive pole with negative pole anodal, process electrode body.The terminal of anodal and negative pole is exposed externally to be accommodated in the battery can.Then, behind the nonaqueous electrolytic solution of after wherein injecting 5mL, stating, carry out riveting molding, make 18650 type cylinder batteries.The electric capacity that the battery key element of taking in 1 battery case of secondary cell is had, promptly the specified discharge capacity of this battery is about 0.7 ampere-hour (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 35 milliohms (m Ω).
Electrolyte [4] embodiment 5
Use the nonaqueous electrolytic solution that uses among electrolyte [4] embodiment 1 as nonaqueous electrolytic solution, make the cylinder battery, and measure power output.The result is shown in electrolyte [4] table 1.
Electrolyte [4] comparative example 2
The nonaqueous electrolytic solution that in using electrolyte [4] comparative example 1, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [4] embodiment 5, and measures power output.The result is shown in electrolyte [4] table 1.
Electrolyte [4] table 1
[table 57]
No. Specific compound Power output (W)
Embodiment 1 Hexamethyl cyclotrisiloxane 500
Embodiment 2 Phenyl dimethyl silicon fluoride 510
Embodiment 3 Methyl fluorosulfonate 510
Embodiment 4 Difluorophosphate 525
Embodiment 5 Hexamethyl cyclotrisiloxane 45
Comparative example 1 --- 390
Comparative example 2 --- 37
Can know by electrolyte [4] table 1; If to each rectangular cell (electrolyte [4] embodiment 1～4; Electrolyte [4] comparative example 1), cylinder battery (electrolyte [4] embodiment 5, electrolyte [4] comparative example 2) compares, but then the power output of the lithium secondary battery of knowledge capital embodiment improves.
As stated, the specified discharge capacity of the rectangular cell of present embodiment and this comparative example is more than 3 ampere-hours (Ah), and DC resistance component is below 10 milliohms (m Ω).On the other hand, the specified discharge capacity of the cylinder battery of present embodiment and this comparative example is less than 3 ampere-hours (Ah), and DC resistance component is greater than 10 milliohms (m Ω).That is, the rectangular cell of present embodiment, this comparative example is compared with the cylinder battery, and resistance is little, and electric capacity is big.And; Electrolyte [4] embodiment 1 improves degree with respect to the power output of electrolyte [4] comparative example 1; Bigger than electrolyte [4] embodiment 5 with respect to the power output raising degree of electrolyte [4] comparative example 2; In the little secondary cell of the big secondary cell of electric capacity or D.C. resistance, effect of the present invention is bigger.
Electrolyte [5] < making of secondary cell >
[anodal making]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.
[making of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.
[assembling of battery]
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in the battery can (external dimensions: in 120 * 110 * 10mm) that has dump valve.Then, in the battery can that the electrode group is housed, inject the nonaqueous electrolytic solution of stating behind the 20mL, electrode is fully soaked into, seal and the making rectangular cell.The electric capacity that the battery key element of taking in 1 battery case of secondary cell is had, promptly the specified discharge capacity of this battery is about 6Ah, and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms (m Ω).
[evaluation of battery]
(solid measure)
To battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.2V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.With the 0.2C discharge capacity of the 5th circulation of this moment as initial capacity.
(output test)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as power output (W).
(cyclic test)
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.After charging to charging upper voltage limit 4.2V with the constant-current constant-voltage method of 2C, be discharged to final discharging voltage 3.0V, this charge and discharge cycles as 1 circulation, is repeated this circulation up to 500 times with the constant current of 2C.
(preserving test)
Under 60 ℃ hot environment, preserve test.The battery that in advance under 25 ℃ environment, charges to charging upper voltage limit 4.2V with the constant-current constant-voltage method is descended preservation 1 month at 60 ℃.
Battery after the solid measure, the battery after the cyclic test, the battery of preserving after testing are carried out output test, respectively as initial stage power output, circulation back power output, preservation back power output.
Electrolyte [5] embodiment 1
Under dry argon atmosphere, in the mixture (volume ratio 2: 5: 3) of ethylene carbonate (EC), methyl ethyl carbonate (EMC) and dimethyl carbonate (DMC), add the LiPF of 1mol/L 6LiN (CF with 0.01mol/L 3SO 2) 2, and dissolve, make the hexamethyl cyclotrisiloxane that contains 0.3 quality % in this mixed solution, the preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution to use the said method manufacture batteries, and measure initial stage power output, circulation back power output and preserve the back power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] embodiment 2
Process the nonaqueous electrolytic solution except using phenyl dimethyl silicon fluoride to substitute hexamethyl cyclotrisiloxane, with electrolyte [5] embodiment 1 manufacture batteries likewise, and measure initial stage power output, circulation back power output and preserve after power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] embodiment 3
Process the nonaqueous electrolytic solution except using methyl fluorosulfonate to substitute hexamethyl cyclotrisiloxane, with electrolyte [5] embodiment 1 manufacture batteries likewise, and measure initial stage power output, circulation back power output and preserve after power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] embodiment 4
Except using according to Inorganic Nuclear Chemistry Letters (1969); The difluorophosphate that the method for record prepares in the 581st page～the 582nd page of 5 (7) substitutes hexamethyl cyclotrisiloxane and processes beyond the nonaqueous electrolytic solution; With electrolyte [5] embodiment 1 manufacture batteries likewise, and measure initial stage power output, circulation back power output and preserve the back power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] embodiment 5
Except using two (oxalate closes) lithium borate (LiBOB) to substitute LiN (CF 3SO 2) 2Process beyond the nonaqueous electrolytic solution,, and measure initial stage power output, circulation back power output and preserve the back power output with electrolyte [5] embodiment 1 manufacture batteries likewise.The result is shown in electrolyte [5] table 1.
Electrolyte [5] embodiment 6
Except using two (oxalate closes) lithium borate (LiBOB) to substitute LiN (CF 3SO 2) 2Process beyond the nonaqueous electrolytic solution,, and measure initial stage power output, circulation back power output and preserve the back power output with electrolyte [5] embodiment 4 manufacture batteries likewise.The result is shown in electrolyte [5] table 1.
Electrolyte [5] comparative example 1
Except not dissolving LiN (CF in the nonaqueous electrolytic solution 3SO 2) 2In addition, with embodiment 1 manufacture batteries likewise, and measure initial stage power output, circulation back power output and preserve the back power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] comparative example 2
In nonaqueous electrolytic solution, do not contain the hexamethyl cyclotrisiloxane,, and measure initial stage power output, circulation back power output and preserve the back power output with electrolyte [5] embodiment 1 manufacture batteries likewise.The result is shown in electrolyte [5] table 1.
Electrolyte [5] comparative example 3
Except not containing LiN (CF in the nonaqueous electrolytic solution 3SO 2) 2Beyond hexamethyl cyclotrisiloxane,, and measure initial stage power output, circulation back power output and preserve the back power output with electrolyte [5] embodiment 1 manufacture batteries likewise.The result is shown in electrolyte [5] table 1.
Electrolyte [5] embodiment 7
< manufacturing of secondary cell-2 >
[anodal manufacturing]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 20 μ m, and dry, rolls into thickness 80 μ m, be cut into wide 52mm again, long 830mm is big or small, as positive pole with press.Wherein, the surperficial back side all is provided with the uncoated part of 50mm in the longitudinal direction, and the length of active material layer is 780mm.
[manufacturing of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is uniformly coated on the two sides as the Copper Foil of the thickness 18 μ m of negative electrode collector, and after the drying, using press to roll into thickness is 85 μ m, is cut into the size of wide 56mm, long 850mm again, as negative pole.Wherein, the surperficial back side all is provided with the uncoated part of 30mm in the longitudinal direction.
[assembling of battery]
Directly do not contact with negative pole with overlapping coiling of the dividing plate of polyethylene system and feasible positive pole with negative pole anodal, process electrode body.The terminal of anodal and negative pole is exposed externally to be accommodated in the battery can.Then, behind the nonaqueous electrolytic solution of after wherein injecting 5mL, stating, carry out riveting molding, make 18650 type cylinder batteries.The electric capacity that the battery key element that the outer dress of 1 battery of secondary cell is taken in has, promptly the specified discharge capacity of secondary cell is about 0.7 ampere-hour (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 35 milliohms (m Ω).
Use the nonaqueous electrolytic solution that uses among electrolyte [5] embodiment 1 to make the cylinder battery, and measure initial stage power output, circulation back power output and preserve the back power output as nonaqueous electrolytic solution.The result is shown in electrolyte [5] table 1.
Electrolyte [5] embodiment 8
The nonaqueous electrolytic solution that in using electrolyte [5] embodiment 2, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [5] embodiment 7, and measures initial stage power output, circulation back power output and preserve the back power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] embodiment 9
The nonaqueous electrolytic solution that in using electrolyte [5] embodiment 3, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [5] embodiment 7, and measures initial stage power output, circulation back power output and preserve the back power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] embodiment 10
The nonaqueous electrolytic solution that in using electrolyte [5] embodiment 4, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [5] embodiment 7, and measures initial stage power output, circulation back power output and preserve the back power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] embodiment 11
The nonaqueous electrolytic solution that in using electrolyte [5] embodiment 5, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [5] embodiment 7, and measures initial stage power output, circulation back power output and preserve the back power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] embodiment 12
The nonaqueous electrolytic solution that in using electrolyte [5] embodiment 6, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [5] embodiment 7, and measures initial stage power output, circulation back power output and preserve the back power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] comparative example 4
The nonaqueous electrolytic solution that in using electrolyte [5] comparative example 1, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [5] embodiment 7, and measures initial stage power output, circulation back power output and preserve the back power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] comparative example 5
The nonaqueous electrolytic solution that in using electrolyte [5] comparative example 2, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [5] embodiment 7, and measures initial stage power output, circulation back power output and preserve the back power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] comparative example 6
The nonaqueous electrolytic solution that in using electrolyte [5] comparative example 3, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [5] embodiment 7, and measures initial stage power output, circulation back power output and preserve the back power output.The result is shown in electrolyte [5] table 1.
Electrolyte [5] table 1
[table 58]
Figure BDA0000087738240003511
Can know by electrolyte [5] table 1; If to each rectangular cell (electrolyte [5] embodiment 1～6; Electrolyte [5] comparative example 1～3), cylinder battery (electrolyte [5] embodiment 7～12, electrolyte [5] comparative example 4～6) compares, then can know and in nonaqueous electrolytic solution, contain LiN (C simultaneously nF 2n+1SO 2) 2The lithium secondary battery of electrolyte [5] embodiment of (in the formula, n is 1～4 integer) and/or two (oxalate closes) lithium borates and specific compound is compared with the lithium secondary battery that does not contain any electrolyte [5] comparative example in these, and power output improves.
As stated, the specified discharge capacity of the rectangular cell of present embodiment and this comparative example is more than 3 ampere-hours (Ah), and DC resistance component is below 10 milliohms (m Ω).On the other hand, the specified discharge capacity of the cylinder battery of present embodiment and this comparative example is less than 3 ampere-hours (Ah), and DC resistance component is greater than 10 milliohms (m Ω).That is, the rectangular cell of present embodiment, this comparative example is compared with the cylinder battery, and resistance is little, and electric capacity is big.And electrolyte [5] embodiment 1 improves degree with respect to the power output of electrolyte [5] comparative example 1, and is bigger with respect to the power output raising degree of electrolyte [5] comparative example 4 than electrolyte [5] embodiment 7.There is big difference in the power output raising degree after particularly the power output after circulation improves degree and preserves.Hence one can see that, and in the little secondary cell of the big secondary cell of electric capacity or D.C. resistance, effect of the present invention is bigger.
Electrolyte [6] < preparation of nonaqueous solvents >
With molecular sieve 4A commercially available ethylene carbonate (EC) is carried out adsorption treatment (50 ℃, LHSV, 1/ hour).On the other hand, with reflux ratio 1, theoretical cam curve 30 column plates dimethyl carbonate and methyl ethyl carbonate are fully carried out rectifying respectively after, carry out adsorption treatment (25 ℃, LHSV, 1/ hour) with molecular sieve 4A.Then, with EC: DMC: EMC (volume ratio 3: 3: 4) they are mixed, further carry out adsorption treatment (25 ℃, LHSV, 1/ hour) with molecular sieve 4A, preparation mixes nonaqueous solvents.At this moment, in the nonaqueous solvents, do not detect water outlet or alcohols.
Electrolyte [6] < making of secondary cell >
[anodal making]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.
[making of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.
[assembling of battery]
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in the battery can (external dimensions: in 120 * 110 * 10mm) that has vent valve.Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.The specified discharge capacity of this battery is a high power capacity, is about 6Ah, and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms.
[evaluation of battery]
(solid measure)
To new battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.2V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.With the 0.2C discharge capacity of the 5th circulation of this moment as initial capacity.
(output test)
Under 25 ℃ environment, the constant current through 0.2C carries out charging in 150 minutes, discharges for 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that current-voltage straight line and lower voltage limit (3V) are surrounded is as power output (W).
(cyclic test)
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is counted as lithium secondary battery, carry out cyclic test.After charging to charging upper voltage limit 4.2V with the constant-current constant-voltage method of 2C, be discharged to final discharging voltage 3.0V, this charge and discharge cycles as 1 circulation, is repeated this circulation up to 500 times with the constant current of 2C.Battery after finishing for cyclic test carries out discharging and recharging of 3 circulations under 25 ℃ of environment, with the 0.2C discharge capacity of the 3rd circulation as circulation back capacity, with this circulation back capacity with respect to the ratio of initial capacity as capability retention.
Electrolyte [6] embodiment 1
Under dry argon atmosphere, in above-mentioned mixing nonaqueous solvents, mix the methyl alcohol of 10ppm amount, add lithium hexafluoro phosphate (LiPF with 0.8mol/L 6), and dissolve.Hydrogen fluoride in the solution after 1 day (HF) amount is 14ppm for 12ppm when measuring once more after 2 weeks.The hexamethyl cyclotrisiloxane that in this mixed solution (after mixing for 2 weeks), mixes the amount of 0.3 quality %, the preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution to use the said method manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] embodiment 2
Except in electrolyte [6] embodiment 1, changing to the combined amount of methyl alcohol with respect to mixing nonaqueous solvents is the amount of 20ppm; Likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 1; Use this nonaqueous electrolytic solution manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.In addition, mix LiPF 6Hydrogen fluoride (HF) amount in the mixed solution after 1 day is 19ppm for 16ppm when measuring once more after 2 weeks.
Electrolyte [6] embodiment 3
Except in electrolyte [6] embodiment 1, changing to the combined amount of methyl alcohol with respect to mixing nonaqueous solvents is the amount of 35ppm; Likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 1; Use this nonaqueous electrolytic solution manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.In addition, mix LiPF 6Hydrogen fluoride (HF) amount in the mixed solution after 1 day is 27ppm for 22ppm when measuring once more after 2 weeks.
Electrolyte [6] embodiment 4
Except in electrolyte [6] embodiment 1, coming the instead of methanol with respect to the ethylene glycol (EG) that mixes nonaqueous solvents mixing 15ppm amount; Likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 1; Use this nonaqueous electrolytic solution manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.In addition, mix LiPF 6Hydrogen fluoride (HF) amount in the mixed solution after 1 day is 16ppm for 14ppm when measuring once more after 2 weeks.
Electrolyte [6] embodiment 5
Except in electrolyte [6] embodiment 1, coming the instead of methanol with respect to the ethylene glycol that mixes nonaqueous solvents mixing 35ppm amount; Likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 1; Use this nonaqueous electrolytic solution to make battery, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.In addition, mix LiPF 6Hydrogen fluoride (HF) amount in the mixed solution after 1 day is 27ppm for 23ppm when measuring once more after 2 weeks.
Electrolyte [6] embodiment 6
Except in electrolyte [6] embodiment 1 with respect to mixing nonaqueous solvents mixing 25ppm methyl alcohol and the 25ppm ethylene glycol; Likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 1; Use this nonaqueous electrolytic solution manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.In addition, mix LiPF 6Hydrogen fluoride (HF) amount in the mixed solution after 1 day is 36ppm for 31ppm when measuring once more after 2 weeks.
Electrolyte [6] embodiment 7
Except the difluorophosphate that in electrolyte [6] embodiment 1, mixes the amount of 0.3 quality % with respect to mixed solution (according to Inorganic Nuclear Chemistry Letters (1969); The method of record preparation in the 581st page～the 582nd page of 5 (7)) comes beyond the alternative hexamethyl cyclotrisiloxane; Likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 1; Use this nonaqueous electrolytic solution manufacture batteries, and measure power output and capability retention calmly.The result is shown in electrolyte [6] table 1.
Electrolyte [6] embodiment 8
Except the difluorophosphate that in electrolyte [6] embodiment 3, mixes the amount of 0.3 quality % with respect to mixed solution comes the alternative hexamethyl cyclotrisiloxane; Likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 3; Use this nonaqueous electrolytic solution manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] embodiment 9
Except the difluorophosphate that in electrolyte [6] embodiment 4, mixes the amount of 0.3 quality % with respect to mixed solution comes the alternative hexamethyl cyclotrisiloxane; Likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 4; Use this nonaqueous electrolytic solution manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] embodiment 10
Except the difluorophosphate that in electrolyte [6] embodiment 6, mixes the amount of 0.3 quality % with respect to mixed solution comes the alternative hexamethyl cyclotrisiloxane; Likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 6; Use this nonaqueous electrolytic solution manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] embodiment 11
Except the methanesulfonic acid trimethyl silyl ester that in electrolyte [6] embodiment 6, mixes the amount of 0.3 quality % with respect to mixed solution comes the alternative hexamethyl cyclotrisiloxane; Likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 6; Use this nonaqueous electrolytic solution manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] embodiment 12
< making of secondary cell-2 >
[anodal making]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 20 μ m, and dry, rolls into thickness 80 μ m, be cut into wide 52mm again, long 830mm is big or small, as positive pole with press.Wherein, the surperficial back side all is provided with the uncoated part of 50mm in the longitudinal direction, and the length of active material layer is 780mm.
[making of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is uniformly coated on the two sides as the Copper Foil of the thickness 18 μ m of negative electrode collector, and after the drying, using press to roll into thickness is 85 μ m, is cut into the size of wide 56mm, long 850mm again, as negative pole.Wherein, the surperficial back side all is provided with the uncoated part of 30mm in the longitudinal direction.
[making of nonaqueous electrolytic solution]
Make the nonaqueous electrolytic solution same with electrolyte [6] embodiment 6.
[assembling of battery]
Directly do not contact with negative pole with overlapping coiling of the dividing plate of polyethylene system and feasible positive pole with negative pole anodal, process electrode body.The terminal of anodal and negative pole is exposed externally to be accommodated in the battery can.Then, behind the nonaqueous electrolytic solution of after wherein injecting 5mL, stating, carry out riveting molding, make 18650 type cylinder batteries.The specified discharge capacity of this battery is about 0.7 ampere-hour (Ah), and the D.C. resistance of measuring with the 10kHz alternating current method is about 35 milliohms (m Ω).For above-mentioned battery, likewise measure power output and capability retention with electrolyte [6] embodiment 6.The result is shown in electrolyte [6] table 1.
Electrolyte [6] comparative example 1
Among electrolyte [6] embodiment 3, use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane and prepare, manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] comparative example 2
Among electrolyte [6] embodiment 5, use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane and prepare, manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] comparative example 3
Among electrolyte [6] embodiment 6, use the nonaqueous electrolytic solution that does not mix hexamethyl cyclotrisiloxane and prepare, manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] comparative example 4
Among electrolyte [6] embodiment 1, use the nonaqueous electrolytic solution that in mixing nonaqueous solvents, does not mix methyl alcohol and prepare, manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.In addition, mix LiPF 6Hydrogen fluoride (HF) amount in the solution after 1 day is 9ppm, still is 9ppm when measuring once more after 2 weeks.
Electrolyte [6] comparative example 5
In electrolyte [6] comparative example 4, the difluorophosphate that use to mix 0.3 quality % substitutes hexamethyl cyclotrisiloxane and the nonaqueous electrolytic solution for preparing, manufacture batteries, and mensuration power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] comparative example 6
In electrolyte [6] comparative example 4, the methanesulfonic acid trimethyl silyl ester that use to mix 0.3 quality % substitutes hexamethyl cyclotrisiloxane and the nonaqueous electrolytic solution for preparing, manufacture batteries, and mensuration power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] comparative example 7
Among electrolyte [6] embodiment 1; Except the combined amount with methyl alcohol changes to respect to mixing nonaqueous solvents is the amount of 700ppm; Likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 1, use this nonaqueous electrolytic solution manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.In addition, mix LiPF 6Hydrogen fluoride (HF) amount in the solution after 1 day is 403ppm for 321ppm when measuring once more after 2 weeks.
Electrolyte [6] comparative example 8
Among electrolyte [6] embodiment 1, use in mixing nonaqueous solvents and do not mix methyl alcohol, and do not mix hexamethyl cyclotrisiloxane and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] comparative example 9
Except in electrolyte [6] embodiment 12, not mixing the hexamethyl cyclotrisiloxane, likewise prepare nonaqueous electrolytic solution with electrolyte [6] embodiment 12, use this nonaqueous electrolytic solution manufacture batteries, and measure power output and capability retention.The result is shown in electrolyte [6] table 1.
Electrolyte [6] table 1
[table 59]
Figure BDA0000087738240003581
Can know by electrolyte [6] table 1; The lithium secondary battery that contains electrolyte [6] comparative example 1～3 of more hydrogen fluoride (HF) is compared with the lithium secondary battery of electrolyte [6] comparative example 8; Inferior aspect characteristics of output power, cycle characteristics two; But be added with the lithium secondary battery of electrolyte [6] embodiment 1～11 of specific compound therein, aspect characteristics of output power, cycle characteristics two, find the raising of characteristic.Further; Aspect power output; The lithium secondary battery of electrolyte [6] embodiment 1～11 though compare with the lithium secondary battery that contains the poor electrolyte of specific compound hydrogen fluoride (HF) [6] comparative example 4～6, has higher performance; Through there being hydrogen fluoride, being strengthened and improved the surprising result of effect through the power output of specific compound realization.But, contain in the lithium secondary battery of electrolyte [6] comparative example 7 of excessive hydrogen fluoride (HF), obtain the particularly result of cycle characteristics difference.
In addition; Electrolyte [6] embodiment 12 of low capacity, battery structure that D.C. resistance is high only is about 19% with respect to the power output climbing of electrolyte [6] comparative example 9; On the other hand; Electrolyte [6] embodiment 6 of high power capacity, battery structure that D.C. resistance is low is about 29% with respect to the power output climbing of electrolyte [6] comparative example 3 (containing methyl alcohol 25ppm and ethylene glycol 25ppm); Electrolyte [6] embodiment 5 is about 26% with respect to the power output climbing of electrolyte [6] comparative example 2 (containing ethylene glycol 35ppm); Electrolyte [6] embodiment 3 is about 26% with respect to the power output climbing of electrolyte [6] comparative example 1 (containing methyl alcohol 35ppm), and is bigger.Hence one can see that in the low battery structure of high power capacity, D.C. resistance, and effect of the present invention is big especially.
As stated; The nonaqueous electrolytic solution of the application of the invention; The secondary cell that just in nonaqueous solvents, mixes fluorine-containing lithium salts and form is used nonaqueous electrolytic solution; Cycle characteristics can variation; And can obtain big characteristics of output power, said secondary cell with the characteristic of nonaqueous electrolytic solution is: the hydrogen fluoride in the above-mentioned nonaqueous electrolytic solution (HF) is 10ppm～300ppm, also contains at least a compound that is selected from the following substances; And its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises: the compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that have the S-F key in the fluorosilane compounds of the cyclic siloxane compound of general formula (1) expression, general formula (2) expression, the compound of general formula (3) expression, the molecule.
In the present embodiment, add alcohols, can bring into play effect, when still in nonaqueous solvents, containing alcohols or moisture originally,, needn't specially add alcohols, can obtain same effect through regulating the purification condition of nonaqueous solvents through nonaqueous solvents to purifying.In general, the purifying of nonaqueous solvents need spend time, causes that in industry cost improves, and among the present invention, can need not unnecessary purifying and prepare high performance nonaqueous electrolytic solution that its value is very big.
Electrolyte [7] < making of battery-1 >
[anodal manufacturing]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 20 μ m, and dry, rolls into thickness 80 μ m, be cut into wide 52mm again, long 830mm is big or small, as positive pole with press.Wherein, the surperficial back side all is provided with the uncoated part of 50mm in the longitudinal direction, and the length of active material layer is 780mm.
[making of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is uniformly coated on the two sides as the Copper Foil of the thickness 18 μ m of negative electrode collector, and after the drying, using press to roll into thickness is 85 μ m, is cut into the size of wide 56mm, long 850mm again, as negative pole.Wherein, the surperficial back side all is provided with the uncoated part of 30mm in the longitudinal direction.
[preparation of electrolyte]
Under dry argon atmosphere, in 3: 3: 4 the mixed solvent of volume ratio of ethylene carbonate (EC), dimethyl carbonate (DMC) and the methyl ethyl carbonate (EMC) of purifying, with the lithium hexafluoro phosphate (LiPF of the concentration dissolving intensive drying of 1mol/L 6), preparation nonaqueous electrolytic solution (1).Further make contain in this nonaqueous electrolytic solution (1) 0.5 quality % according to Inorganic Nuclear Chemistry Letters (1969), the difluorophosphate of the method for record preparation in the 581st page～the 582nd page of 5 (7), preparation nonaqueous electrolytic solution (2).
[assembling of battery]
Directly do not contact with negative pole with overlapping coiling of the dividing plate of polyethylene system and feasible positive pole with negative pole anodal, process electrode body.The terminal of anodal and negative pole is exposed externally to be accommodated in the battery can.Then, behind the nonaqueous electrolytic solution of after wherein injecting 5mL, stating, carry out riveting molding, make 18650 type cylinder batteries.
[evaluation of battery]
(initial stage discharges and recharges)
To the cylindrical battery of making, 25 ℃ charge to 4.2V with the constant-current constant-voltage mise-a-la-masse methods of 0.2C down after, be discharged to 3.0V with the constant current of 0.2C.It is carried out 5 circulations makes battery stable.With the discharge capacity of the 5th circulation of this moment as initial capacity.In addition, with 1 hour the discharge rated capacity current value as 1C, said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate).
(cyclic test)
The battery that the initial stage of having implemented is discharged and recharged after charging to 4.2V with the constant-current constant-voltage of 1C under 60 ℃, is discharged to 3.0V with the constant current of 1C, and such discharging and recharging carried out 500 circulations.With the 500th cyclic discharge capacity of this moment with respect to the ratio of the 1st cyclic discharge capacity as the circulation conservation rate.
(low-temperature test)
The battery that the initial stage of having implemented is discharged and recharged, 25 ℃ charge to 4.2V with the constant-current constant-voltage mise-a-la-masse methods of 0.2C down after, discharge at-30 ℃ of constant currents of implementing 0.2C down.With the discharge capacity of this moment as initial stage low temperature capacity, with initial stage low temperature capacity with respect to the ratio of initial capacity as initial stage low temperature discharge rate.
In addition, to the battery after the cyclic test 25 ℃ down charge to 4.2V with the constant-current constant-voltage mise-a-la-masse methods of 0.2C after, be discharged to 3.0V with the constant current of 0.2C.It is carried out 3 circulations, with the discharge capacity of its 3rd circulation as circulation back capacity.Then, to same battery after charging to 4.2V with the constant-current constant-voltage mise-a-la-masse method of 0.2C under 25 ℃ ,-30 ℃ of constant currents discharges of implementing 0.2C down.With the discharge capacity of this moment as circulation back low temperature capacity, with circulation back low temperature capacity with respect to the ratio of circulation back capacity as circulation back low temperature discharge rate.
Electrolyte [7] embodiment 1
In nonaqueous electrolytic solution (2), with respect to whole electrolyte qualities to be the amount mixed carbonic acid vinylene (below abbreviate " VC " as) of 1 quality %, preparation nonaqueous electrolytic solution (3).Use this nonaqueous electrolytic solution (3), make 18650 type batteries, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [7] table 1.In addition, discharge and recharge the battery after the end from the initial stage with centrifugal separator and to reclaim electrolyte, the amount of the VC that records is 0.40 quality %.
Electrolyte [7] comparative example 1
Use nonaqueous electrolytic solution (1), likewise make 18650 type batteries, and measure circulation conservation rate and low temperature discharge rate with electrolyte [7] embodiment 1.The result is shown in electrolyte [7] table 1.
Electrolyte [7] comparative example 2
In nonaqueous electrolytic solution (1), with respect to total electrolyte quality to be the amount mixing VC of 1 quality %, preparation nonaqueous electrolytic solution (4).Use this nonaqueous electrolytic solution (4), likewise make 18650 type batteries, and measure circulation conservation rate and low temperature discharge rate with electrolyte [7] embodiment 1.The result is shown in electrolyte [7] table 1.In addition, discharge and recharge the battery after the end from the initial stage with centrifugal separator and to reclaim electrolyte, the amount of the VC that records is 0.22 quality %.
Electrolyte [7] comparative example 3
Except use nonaqueous electrolytic solution (2), and do not mix beyond the VC, likewise make 18650 type batteries, and measure circulation conservation rate and low temperature discharge rate with electrolyte [7] embodiment 1.The result is shown in electrolyte [7] table 1.
Electrolyte [7] comparative example 4
In nonaqueous electrolytic solution (2), with respect to total electrolyte quality to be the amount mixing VC of 5 quality %, preparation nonaqueous electrolytic solution (5).In electrolyte [7] embodiment 1, use this nonaqueous electrolytic solution (5), make 18650 type batteries, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [7] table 1.
Electrolyte [7] embodiment 2
< making of battery-2 >
[anodal making]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.
[making of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.
[assembling of battery]
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in battery can (external dimensions: in 120 * 110 * 10mm).Then, in the battery can that the electrode group is housed, inject 20mL nonaqueous electrolytic solution (3), electrode is fully soaked into, seal and the making rectangular cell.
To the rectangular cell of such making, adopt with electrolyte [7] embodiment 1 identical method and implement cyclic test, low-temperature test, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [7] table 1.
Electrolyte [7] comparative example 5
Among electrolyte [7] embodiment 2, use nonaqueous electrolytic solution (1) to substitute nonaqueous electrolytic solution (3), make rectangular cell, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [7] table 1.
Electrolyte [7] comparative example 6
Among electrolyte [7] embodiment 2, use nonaqueous electrolytic solution (4) to substitute nonaqueous electrolytic solution (3), make rectangular cell, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [7] table 1.
Electrolyte [7] comparative example 7
Among electrolyte [7] embodiment 2, use nonaqueous electrolytic solution (2) to substitute nonaqueous electrolytic solution (3), make rectangular cell, and measure circulation conservation rate and low temperature discharge rate.The result is shown in electrolyte [7] table 1.
Electrolyte [7] table 1
[table 60]
Figure BDA0000087738240003631
Can know by electrolyte [7] table 1; Contain in the nonaqueous electrolytic solution vinylene carbonate and difluorophosphoric acid salt electrolyte [7] embodiment 1 lithium secondary battery with do not compare for the lithium secondary battery of the electrolyte of same structure [7] comparative example 1 except in nonaqueous electrolytic solution, not containing them, circulation conservation rate, low temperature discharge rate all improve.
Can know in addition, though with compare for the lithium secondary battery of the electrolyte of same structure [7] comparative example 2 except in nonaqueous electrolytic solution, only containing the VC, circulation conservation rate, low temperature discharge rate also all improve.The circulation conservation rate is because of the significant change that has or not of VC, and through to wherein adding difluorophosphoric acid salt, its effect increases.There is about 2 times difference in the VC amount that battery detecting after being discharged and recharged by the initial stage goes out, thinks that wherein residual VC has suppressed the deterioration of battery in the cyclic test.
Can know by electrolyte [7] embodiment 1 and electrolyte [7] comparative example 3, only can not fully improve the circulation conservation rate through difluorophosphoric acid salt.In addition, the lithium secondary battery of electrolyte [7] embodiment 1 is compared with the lithium secondary battery of electrolyte [7] comparative example 3, though initial stage low temperature discharge rate is identical, the conservation rate that not only circulates has big improvement, and circulation back low temperature discharge efficient also is improved.Through the synergy of VC and difluorophosphoric acid salt, suppressed because the increase of the inside battery resistance that cyclic test caused.
More than between electrolyte [7] embodiment 2 and electrolyte [7] comparative example 5～7, also be same.
If the lithium secondary battery to electrolyte [7] embodiment 1 compares with the lithium secondary battery that contains electrolyte [7] comparative example 4 of more VC; Then can know in electrolyte [7] comparative example 4; Though the circulation conservation rate is quite excellent; But the cryogenic discharging characteristic significance difference can not tolerate the use under low temperature environment.
The value of the D.C. resistance that adopts 10kHz alternating current method mensuration has been shown in the table.The rectangular cell of this experiment is compared with the cylinder battery, and resistance is little, electric capacity is big.Compare with respect to the low-temperature characteristics raising degree of electrolyte [7] comparative example 1 with electrolyte [7] embodiment 1; Electrolyte [7] embodiment 2 is big with respect to the low-temperature characteristics raising degree of electrolyte [7] comparative example 5; Can know the objective for implementation as nonaqueous electrolytic solution of the present invention, the secondary cell that secondary cell that electric capacity is high or D.C. resistance are little is specially suitable.
Electrolyte [8] < making of secondary cell >
[anodal making]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.
[making of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.
[assembling of battery]
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in the battery can (external dimensions: in 120 * 110 * 10mm) that has vent valve.Then, in the battery can that the electrode group is housed, inject the nonaqueous electrolytic solution of stating behind the 20mL, electrode is fully soaked into, seal and the making rectangular cell.
The electric capacity that the battery key element of taking in 1 battery case of secondary cell is had, promptly the specified discharge capacity of secondary cell is about 6 ampere-hours (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 5 milliohms (m Ω).
Electrolyte [8] < evaluation of battery >
[circulation conservation rate]
[initial stage discharges and recharges]
25 ℃ down charge to 4.2V with the constant-current constant-voltage mise-a-la-masse methods of 0.2C after, be discharged to 3.0V with the constant current of 0.2C.It is carried out 5 circulations makes battery stable.With the discharge capacity of the 5th circulation of this moment as initial capacity.And, with 1 hour the discharge rated capacity current value as 1C.
(cyclic test)
To the battery that the initial stage of having implemented discharges and recharges, the constant-current constant-voltage method with 1C under 60 ℃ charges to 4.2V, and the constant current with 1C is discharged to 3.0V then, this is discharged and recharged carry out 500 circulations.With the 500th cyclic discharge capacity of this moment with respect to the ratio of the 1st cyclic discharge capacity as the circulation conservation rate.
[initial stage low temperature discharge rate]
(low-temperature test)
The battery that the initial stage of having implemented is discharged and recharged, 25 ℃ charge to 4.2V with the constant-current constant-voltage mise-a-la-masse methods of 0.2C down after, discharge at-30 ℃ of constant currents of implementing 0.2C down.With the discharge capacity of this moment as initial stage low temperature capacity, with initial stage low temperature capacity with respect to the ratio of initial capacity as initial stage low temperature discharge rate.
[circulation back low temperature discharge rate]
In addition, the constant-current constant-voltage mise-a-la-masse method with 0.2C under 25 ℃ of the battery after the cyclic test is charged to 4.2V, the constant current with 0.2C is discharged to 3.0V then.It is carried out 3 circulations, with the discharge capacity of its 3rd circulation as circulation back capacity.Then, same battery constant-current constant-voltage mise-a-la-masse method with 0.2C under 25 ℃ is charged to 4.2V, then-30 ℃ of constant current discharges of implementing 0.2C down.With the discharge capacity of this moment as circulation back low temperature capacity, with circulation back low temperature capacity with respect to the ratio of circulation back capacity as circulation back low temperature discharge rate.
Electrolyte [8] embodiment 1
Under dry argon atmosphere, in the mixture (volume ratio 2: 5: 3) of ethylene carbonate (EC), methyl ethyl carbonate (EMC) and dimethyl carbonate (DMC), add LiPF with 1mol/L 6, and dissolve, make and contain 0.3 quality % hexamethyl cyclotrisiloxane, 1 quality % vinylethylene carbonate in this mixed solution, the preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution to use the said method manufacture batteries, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate.The result is shown in electrolyte [8] table 1.
Electrolyte [8] embodiment 2
Process the nonaqueous electrolytic solution except using phenyl dimethyl silicon fluoride to substitute hexamethyl cyclotrisiloxane,, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation low temperature discharge rate afterwards with electrolyte [8] embodiment 1 manufacture batteries likewise.The result is shown in electrolyte [8] table 1.
Electrolyte [8] embodiment 3
Process the nonaqueous electrolytic solution except using methyl fluorosulfonate to substitute hexamethyl cyclotrisiloxane,, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation low temperature discharge rate afterwards with electrolyte [8] embodiment 1 manufacture batteries likewise.The result is shown in electrolyte [8] table 1.
Electrolyte [8] embodiment 4
Except using according to Inorganic Nuclear Chemistry Letters (1969); The difluorophosphate that the method for record prepares in the 581st page～the 582nd page of 5 (7) substitutes hexamethyl cyclotrisiloxane and processes beyond the nonaqueous electrolytic solution; With electrolyte [8] embodiment 1 manufacture batteries likewise, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate.The result is shown in electrolyte [8] table 1.
Electrolyte [8] embodiment 5
Except using 1,3-third sultone substitutes vinylethylene carbonate and processes beyond the nonaqueous electrolytic solution, with electrolyte [8] embodiment 1 manufacture batteries likewise, and measures circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate.The result is shown in electrolyte [8] table 1.
Electrolyte [8] embodiment 6
Process the nonaqueous electrolytic solution except using gamma-butyrolacton to substitute vinylethylene carbonate,, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate with electrolyte [8] embodiment 1 manufacture batteries likewise.The result is shown in electrolyte [8] table 1.
Electrolyte [8] embodiment 7
Process the nonaqueous electrolytic solution except using the fluorine ethylene carbonate to substitute vinylethylene carbonate,, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate with electrolyte [8] embodiment 1 manufacture batteries likewise.The result is shown in electrolyte [8] table 1.
Electrolyte [8] embodiment 8
Except using 1,3-third sultone substitutes vinylethylene carbonate and processes beyond the nonaqueous electrolytic solution, with electrolyte [8] embodiment 4 manufacture batteries likewise, and measures circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate.The result is shown in electrolyte [8] table 1.
Electrolyte [8] embodiment 9
Process the nonaqueous electrolytic solution except using gamma-butyrolacton to substitute vinylethylene carbonate,, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate with electrolyte [8] embodiment 4 manufacture batteries likewise.The result is shown in electrolyte [8] table 1.
Electrolyte [8] embodiment 10
Process the nonaqueous electrolytic solution except using the fluorine ethylene carbonate to substitute vinylethylene carbonate,, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate with electrolyte [8] embodiment 4 manufacture batteries likewise.The result is shown in electrolyte [8] table 1.
Electrolyte [8] comparative example 1
Except nonaqueous electrolytic solution is not contained the hexamethyl cyclotrisiloxane,, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate with electrolyte [8] embodiment 1 manufacture batteries likewise.The result is shown in electrolyte [8] table 1.
Electrolyte [8] comparative example 2
Except nonaqueous electrolytic solution is not contained the vinylethylene carbonate,, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate with electrolyte [8] embodiment 1 manufacture batteries likewise.The result is shown in electrolyte [8] table 1.
Electrolyte [8] comparative example 3
Except making nonaqueous electrolytic solution not contain hexamethyl cyclotrisiloxane and the vinylethylene carbonate,, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate with electrolyte [8] embodiment 1 manufacture batteries likewise.The result is shown in electrolyte [8] table 1.
Electrolyte [8] embodiment 11
< making of secondary cell-2 >
[anodal making]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 20 μ m, and dry, rolls into thickness 80 μ m, be cut into wide 52mm again, long 830mm is big or small, as positive pole with press.Wherein, the surperficial back side all is provided with the uncoated part of 50mm in the longitudinal direction, and the length of active material layer is 780mm.
[making of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is uniformly coated on the two sides as the Copper Foil of the thickness 18 μ m of negative electrode collector, and after the drying, using press to roll into thickness is 85 μ m, is cut into the size of wide 56mm, long 850mm again, as negative pole.Wherein, the surperficial back side all is provided with the uncoated part of 30mm in the longitudinal direction.
[assembling of battery]
Directly do not contact with negative pole with overlapping coiling of the dividing plate of polyethylene system and feasible positive pole with negative pole anodal, process electrode body.The terminal of anodal and negative pole is exposed externally to be accommodated in the battery can.Then, behind the nonaqueous electrolytic solution of after wherein injecting 5mL, stating, carry out riveting molding, make 18650 type cylinder batteries.The electric capacity that the battery key element of taking in 1 battery case of secondary cell is had, promptly the specified discharge capacity of this battery is about 0.7 ampere-hour (Ah), and the DC resistance component of measuring with the 10kHz alternating current method is about 35 milliohms (m Ω).
Use the nonaqueous electrolytic solution that uses among electrolyte [8] embodiment 1 as nonaqueous electrolytic solution, make the cylinder battery, and measure circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate.The result is shown in electrolyte [8] table 1.
Electrolyte [8] embodiment 12
The nonaqueous electrolytic solution that in using electrolyte [8] embodiment 4, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [8] embodiment 11, and measures circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate.The result is shown in electrolyte [8] table 1.
Electrolyte [8] comparative example 4
The nonaqueous electrolytic solution that in using electrolyte [8] comparative example 1, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [8] embodiment 11, and measures circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate.The result is shown in electrolyte [8] table 1.
Electrolyte [8] comparative example 5
The nonaqueous electrolytic solution that in using electrolyte [8] comparative example 2, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [8] embodiment 11, and measures circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate.The result is shown in electrolyte [8] table 1.
Electrolyte [8] comparative example 6
The nonaqueous electrolytic solution that in using electrolyte [8] comparative example 3, uses is likewise made the cylinder battery as the nonaqueous electrolytic solution with electrolyte [8] embodiment 11, and measures circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate.The result is shown in electrolyte [8] table 1.
Electrolyte [8] table 1
[table 61]
Can know by electrolyte [8] table 1; If to each rectangular cell (electrolyte [8] embodiment 1～10; Use in electrolyte [8] comparative example 1～3), cylinder battery (electrolyte [8] embodiment 11,12; Use in electrolyte [8] comparative example 4～6) compare; The lithium secondary battery that then contains electrolyte [8] embodiment of at least a specific compound A and at least a specific compound B in the nonaqueous electrolytic solution is simultaneously compared with the lithium secondary battery that does not contain these any one electrolyte [8] comparative example, and circulation conservation rate, initial stage low temperature discharge rate and circulation back low temperature discharge rate all improve.
As stated, the specified discharge capacity of the rectangular cell of present embodiment and this comparative example is more than 3 ampere-hours (Ah), and DC resistance component is below 10 milliohms (m Ω).On the other hand, the specified discharge capacity of the cylinder battery of present embodiment and this comparative example is less than 3 ampere-hours (Ah), and DC resistance component is greater than 10 milliohms (m Ω).That is, the rectangular cell of present embodiment, this comparative example is compared with the cylinder battery, and resistance is little, and electric capacity is big.And; Electrolyte [8] embodiment 1 is with respect to the power output rising degree of electrolyte [8] comparative example 1; Bigger than electrolyte [8] embodiment 11 with respect to the power output rising degree of electrolyte [8] comparative example 4; In the little secondary cell of the big secondary cell of electric capacity or D.C. resistance, effect of the present invention is bigger.
Electrolyte [9] < making of secondary cell >
[anodal making]
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 80 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.
[making of negative pole]
In 98 weight portion Delanium powder KS-44 (timcal manufactured; Trade name) adds 100 weight portions in as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the Copper Foil two sides of thickness 10 μ m, and dry, using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.
[assembling of battery]
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole uncoated part welding separately, make collector plate, the electrode group is sealed in the battery can (external dimensions: in 120 * 110 * 10mm) that has vent valve.Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, seal and the making rectangular cell.
[electric capacity and DC resistance component]
The specified discharge capacity of this battery (electric capacity of taking in 1 battery case that the battery key element had) for high power capacity, be about 6Ah, be about 5 milliohms with the DC resistance component of 10kHz alternating current method mensuration.
[evaluation of battery]
(assay method of capacity)
To new battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.2V～3.0V; With the current value of 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.With the 0.2C discharge capacity of the 5th circulation of this moment as capacity.
(preserving back 5C discharge capacity)
Under 60 ℃ hot environment, preserve test.The battery that in advance under 25 ℃ environment, charges to charging upper voltage limit 4.2V with the constant-current constant-voltage method is descended preservation 1 month at 60 ℃.Battery for after preserving carries out speed trial under 25 ℃ environment.That is, the battery that in advance under 25 ℃ environment, charges to charging upper voltage limit 4.2V with the constant-current constant-voltage method is discharged with the constant current value that is equivalent to 5C, as the back 5C discharge capacity of preservation.
(overcharge test)
Under 25 ℃ of environment, carry out overcharge test.Charge by the constant current of discharge condition (3V), observe its movement with 3C.Wherein, " valve work " expression vent valve work also discharges the phenomenon of bath composition, " breaking " expression battery case with the fierce impetus break, content is forced the phenomenon that discharges.
Electrolyte [9] embodiment 1
Under dry argon atmosphere, in the mixture (volume ratio 3: 3: 4) of ethylene carbonate (EC), dimethyl carbonate (DMC), methyl ethyl carbonate (EMC), add lithium hexafluoro phosphate (LiPF with 1mol/L 6), and dissolve the hexamethyl cyclotrisiloxane of the amount of the cyclohexyl benzene (CHB) of the amount of mixing 1 quality % and 0.3 quality % in this mixed solution, preparation nonaqueous electrolytic solution.Use this nonaqueous electrolytic solution to use the said method manufacture batteries, and measure and preserve back 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] embodiment 2
Use has mixed that phenyl dimethyl silicon fluoride comes the hexamethyl cyclotrisiloxane among alternative electrolyte [9] embodiment 1 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure and preserve back 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] embodiment 3
Use has mixed that methanesulfonic acid trimethyl silyl ester comes the hexamethyl cyclotrisiloxane among alternative electrolyte [9] embodiment 1 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure and preserve back 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] embodiment 4
Use has mixed according to Inorganic Nuclear Chemistry Letters (1969); The difluorophosphate of the method preparation of record comes the hexamethyl cyclotrisiloxane among alternative electrolyte [9] embodiment 1 and the nonaqueous electrolytic solution for preparing in the 581st page～the 582nd page of 5 (7); Manufacture batteries, and measure and preserve back 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] embodiment 5
Use has mixed that biphenyl comes the cyclohexyl benzene among alternative electrolyte [9] embodiment 1 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure and preserve back 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] embodiment 6
Use has mixed that phenyl dimethyl silicon fluoride comes the hexamethyl cyclotrisiloxane among alternative electrolyte [9] embodiment 5 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure and preserve back 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] embodiment 7
Use has mixed that methanesulfonic acid trimethyl silyl ester comes the hexamethyl cyclotrisiloxane among alternative electrolyte [9] embodiment 5 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure and preserve back 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] embodiment 8
Use has mixed according to Inorganic Nuclear Chemistry Letters (1969); The difluorophosphate of the method preparation of record comes the hexamethyl cyclotrisiloxane among alternative electrolyte [9] embodiment 5 and the nonaqueous electrolytic solution for preparing in the 581st page～the 582nd page of 5 (7); Manufacture batteries, and measure and preserve back 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] embodiment 9
Use has mixed that tert-amyl benzene comes the cyclohexyl benzene among alternative electrolyte [9] embodiment 1 and the nonaqueous electrolytic solution for preparing, manufacture batteries, and measure and preserve back 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] embodiment 10
The content that use has mixed meta-terphenyl is that 3.7 quality %, partial hydrogenation rate are the nonaqueous electrolytic solution that 42% " the partial hydrogenation thing of meta-terphenyl " comes the cyclohexyl benzene among alternative electrolyte [9] embodiment 1 to prepare; Manufacture batteries, and measure and preserve back 5C discharge capacity.The result is shown in electrolyte [9] table 1.In addition, the partial hydrogenation thing of the meta-terphenyl that uses among electrolyte [9] embodiment uses with meta-terphenyl to be raw material, under the coexistence of platinum, palladium or nickel class catalyst, and the material that it is obtained with hydrogen reaction under the high-temperature pressurizing condition.In addition, the partial hydrogenation rate is averaged by the ratio of components of the constituent of the partial hydrogenation thing of the meta-terphenyl of trying to achieve through gas chromatographic analysis and is confirmed.The content of meta-terphenyl is also tried to achieve by this gas chromatographic analysis value.
Electrolyte [9] comparative example 1
The nonaqueous electrolytic solution that uses unmixed hexamethyl cyclotrisiloxane among electrolyte [9] embodiment 1 and prepare comes manufacture batteries, and measures the 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] comparative example 2
The nonaqueous electrolytic solution that uses unmixed hexamethyl cyclotrisiloxane among electrolyte [9] embodiment 5 and prepare comes manufacture batteries, and measures the 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] comparative example 3
The nonaqueous electrolytic solution that uses unmixed hexamethyl cyclotrisiloxane among electrolyte [9] embodiment 9 and prepare is made battery, and the 5C discharge capacity is measured.The result is shown in electrolyte [9] table 1.
Electrolyte [9] comparative example 4
The nonaqueous electrolytic solution that uses unmixed hexamethyl cyclotrisiloxane among electrolyte [9] embodiment 10 and prepare comes manufacture batteries, and measures the 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] comparative example 5
Use unmixed hexamethyl cyclotrisiloxane, CHB among electrolyte [9] embodiment 1 any one and the nonaqueous electrolytic solution for preparing comes manufacture batteries, and measure the 5C discharge capacity.The result is shown in electrolyte [9] table 1.
Electrolyte [9] table 1
[table 62]
Figure BDA0000087738240003741
Can know by electrolyte [9] table 1; In nonaqueous electrolytic solution, containing overcharges prevents the lithium secondary battery of electrolyte [9] embodiment 1～10 of agent and specific compound; When overcharge test, can avoid cell fracture self-evidently, also show the characteristic more excellent in big electric current (5C) discharge test after preservation than the lithium secondary battery of electrolyte [9] comparative example 1～4.This characteristic can know that near the lithium secondary battery that does not contain electrolyte [9] comparative example 5 that prevents agent of overcharging practical value is very high when improving overcharge safety.
As stated; The secondary cell that the mixing lithium salts forms in nonaqueous solvents that has following characteristics through use is used nonaqueous electrolytic solution; Can satisfy high heavy-current discharge characteristic and overcharge safety simultaneously; Said secondary cell with the characteristic of nonaqueous electrolytic solution is: containing overcharges prevents agent; Also contain at least a compound that is selected from the following substances; And its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises: the compound, nitrate, nitrite, mono-fluor phosphate, difluorophosphoric acid salt, acetate and the propionate that have the S-F key in the fluorosilane compounds of the cyclic siloxane compound of general formula (1) expression, general formula (2) expression, the compound of general formula (3) expression, the molecule.The electric capacity that is particularly had for the battery key element of taking in 1 battery case is the above batteries that in the past are difficult to satisfy simultaneously these 2 key elements of 3 ampere-hours (Ah), can have high practicability.
Structure [1]～[5] embodiment 1
" making of nonaqueous electrolytic solution "
Under dry argon atmosphere, in 3: 3: 4 the mixed solvent of volume ratio of ethylene carbonate (EC), dimethyl carbonate (DMC) and the methyl ethyl carbonate (EMC) of purifying with the lithium hexafluoro phosphate (LiPF of the concentration dissolving intensive drying of 1mol/L 6).In addition, make it contain the hexamethyl cyclotrisiloxane of 0.3 quality %.
" anodal making "
The lithium-transition metal composite oxide of positive active material for synthesizing with following method is with composition formula LiMn 0.33Ni 0.33Co 0.33O 2Expression.With Mn: Ni: Co=1: 1: 1 molar ratio weighing is as the Mn of manganese raw material 3O 4, as the NiO of nickel raw material and as the Co (OH) of cobalt raw material 2, to wherein adding pure water, process slurry, use circulating medium-stirring wet-type ball mill with the 0.2 μ m of solid constituent case of wet attrition to the median particle diameter in the slurry while stirring.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 5 μ m of particle diameter of manganese raw material, nickel raw material, cobalt raw material.In the granulation particle that obtains, add the LiOH powder of median particle diameter 3 μ m; And the ratio of the molal quantity that makes Li and the total mole number of Mn, Ni and Co is 1.05; Mix with high-speed mixer, obtain the granulation particle of nickel raw material, cobalt raw material, manganese raw material and the mixed-powder of lithium raw material.Under circulation of air, 950 ℃ this mixed-powder fired 12 hours (warming and cooling rate is 5 ℃/minute) after, pulverize, the sieve through mesh 45 μ m obtains positive active material.The BET specific area of this positive active material is 1.2m 2/ g, average primary particle diameter are 0.8 μ m, median particle diameter d 50Be 4.4 μ m, tap density is 1.6g/cm 3
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, rolls into thickness 81 μ m with press, be cut into again have wide 100mm, the shape of the uncoated part of active material layer that long 100mm is big or small and wide 30mm, as positive pole.The density of positive electrode active material layer is 2.35g/cm 3, (thickness of the positive electrode active material layer of one side)/(thickness of collector body) is 2.2, L/ (2 * S 2) be 0.2.
" making of negative pole "
In order to prevent to sneak into oversize grain in the commercially available native graphite powder as the particulate carbonaceous material, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative material that obtains like this as carbonaceous material (A).
The petroleum-type heavy oil that obtains when in carbonaceous material (A), mixing the naphtha pyrolysis; In non-active gas, implement 1300 ℃ carbonization treatment; Then; Obtain composite carbonaceous material through sinter is carried out hierarchical processing, as negative electrode active material, said composite carbonaceous material is on carbonaceous material (A) particle surface, to have coated the composite carbonaceous material with different crystalline carbonaceous material.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times in order to prevent to sneak into oversize grain.Can confirm that from carbon yield the negative electrode active material powder that obtains is coated by the low-crystalline carbonaceous material that with respect to 95 weight portion graphite is 5 weight.The rerum natura of negative electrode active material is shown in structure [1]～[5] table 1.
Structure [1]～[5] table 1
[table 63]
Figure BDA0000087738240003761
In the above-mentioned negative electrode active material of 98 weight portions, add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the two sides of the rolled copper foil of thickness 10 μ m; And it is dry; Using press to roll into thickness is 75 μ m, be cut into again have wide 104mm, the shape of the uncoated part of active material layer that long 104mm is big or small and wide 30mm, as negative pole.The density of the negative electrode active material of this moment is 1.35g/cm 3, L/ (2 * S 2) be 0.19.
" making of battery "
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With harness between this positive pole and the negative pole uncoated part separately, carry out means of spot welds, make collector plate, the electrode group is sealed in the battery can (external dimensions: in 120 * 110 * 10mm) of aluminum.As battery can, use the battery can of inlet that has current-collecting terminals, pressure relief valve, the nonaqueous electrolytic solution of anodal and negative pole at cover.Collector plate is connected through the some welding with current-collecting terminals.Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into, sealing inlet, manufacture batteries.The summation of anodal electrode area is 20.5,2 * S with respect to the ratio of the long-pending summation of case surface of battery 1/ T is 264, and electrode group occupation rate is 0.54.
" evaluation of battery "
(assay method of battery capacity)
To without the new battery that discharges and recharges; Under 25 ℃, the voltage range of 4.1V～3.0V with current value 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) initial stage of carrying out 5 circulations discharges and recharges.With the 0.2C discharge capacity of the 5th circulation of this moment as initial capacity.The result of cell evaluation is shown in structure [1]～[5] table 2.
(assay method of initial stage power output)
Constant current through 0.2C under 25 ℃ of environment carries out charging in 150 minutes, discharges 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that will be surrounded by current-voltage straight line and lower voltage limit (3V) is as power output (W).The result of cell evaluation is shown in structure [1]～[5] table 2.
(assay method of initial stage series resistance)
Constant current through 0.2C under 25 ℃ of environment carries out charging in 150 minutes, applies the interchange of 10kHz, measures impedance, as D.C. resistance.The result of cell evaluation is shown in structure [1]～[5] table 2.
(cyclic test (assay method of durable back battery capacity and durable back power output))
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.After charging to charging upper voltage limit 4.1V with the constant-current constant-voltage method of 2C, be discharged to final discharging voltage 3.0V, this charge and discharge cycles as 1 circulation, is carried out this circulation repeatedly and circulated until 500 with the constant current of 2C.Battery after finishing for cyclic test carries out 3 cycle charge-discharges with current value 0.2C under 25 ℃ of environment, with the 0.2C discharge capacity of its 3rd circulation as durable back battery capacity.In addition, the battery for after the cyclic test end carries out output test, as durable back power output, series resistance is measured, as durable back series resistance.The result of cell evaluation is shown in structure [1]～[5] table 2.
(overcharge test)
Under 25 ℃ of environment, carry out overcharge test.Charge by the constant current of discharge condition (3V), observe its movement with 3C.Wherein, " valve work " expression vent valve work also discharges the phenomenon of bath composition, " breaking " expression battery case with the fierce impetus break, content is forced the phenomenon that discharges.The result of cell evaluation is shown in structure [1]～[5] table 2.
Structure [1]～[5] embodiment 2
Make the methanesulfonic acid trimethyl silyl ester that contains 0.3 quality % in the nonaqueous electrolytic solution come the hexamethyl cyclotrisiloxane among alternative structure [1]～[5] embodiment 1; In addition; With structure [1]～[5] embodiment 1 manufacture batteries likewise, and likewise carry out cell evaluation.The result is shown in structure [1]～[5] table 2.
Structure [1]～[5] embodiment 3
Make the phenyl dimethyl silicon fluoride that contains 0.3 quality % in the nonaqueous electrolytic solution come the hexamethyl cyclotrisiloxane among alternative structure [1]～[5] embodiment 1, in addition,, and likewise carry out cell evaluation with structure [1]～[5] embodiment 1 manufacture batteries likewise.The result is shown in structure [1]～[5] table 2.
Structure [1]～[5] embodiment 4
Make the difluorophosphate that contains 0.3 quality % in the nonaqueous electrolytic solution come the hexamethyl cyclotrisiloxane among alternative structure [1]～[5] embodiment 1, in addition,, and likewise carry out cell evaluation with structure [1]～[5] embodiment 1 manufacture batteries likewise.The result is shown in structure [1]～[5] table 2.
Structure [1]～[5] comparative example 1
Make in the nonaqueous electrolytic solution among structure [1]～[5] embodiment 1 and do not contain hexamethyl cyclotrisiloxane, in addition,, and likewise carry out cell evaluation with structure [1]～[5] embodiment 1 manufacture batteries likewise.The result is shown in structure [1]～[5] table 2.
Structure [1]～[5] table 2
[table 64]
Figure BDA0000087738240003781
Structure [1]～[5] embodiment 5
" anodal making "
Use the positive active material identical, likewise prepare slurry with structure [1]～[5] embodiment 1 with structure [1]～[5] embodiment 1.The slurry that obtains is coated on the two sides of aluminium foil of thickness 15 μ m; And carry out drying; Roll into thickness 81 μ m with press; Be cut into the positive electrode active material layer of wide 100mm, long 3200mm size again, and have the shape that every in the longitudinal direction interval 20mm has the uncoated part of wide 6mm, as positive pole.The density of positive electrode active material layer is 2.35g/cm 3, (thickness of the positive electrode active material layer of one side)/(thickness of collector body) is 2.2.The length of anodal Width is 32 with respect to the ratio of the length of length direction.
" making of negative pole "
Use the negative electrode active material identical, likewise prepare slurry with structure [1]～[5] embodiment 1 with structure [1]～[5] embodiment 1.The slurry that obtains is coated on the two sides of rolled copper foil of thickness 10 μ m; And carry out drying; Roll into thickness 75 μ m with press; Be cut into the active material layer of wide 104mm, long 3300mm size again, and have the shape that every in the longitudinal direction interval 20mm has the uncoated part of wide 6mm, as negative pole.The density of the negative electrode active material of this moment is 1.35g/cm 3
" making of battery "
Between each electrode, clip the micro-porous film dividing plate (thickness 25 μ m) of porous polyethylene sheet and make and anodally directly do not contact with negative pole, make in addition uncoated part be an opposite side positive pole and negative pole is overlapping and be wound into circle, process electrode body.On the central shaft that harness is reeled, should carry out means of spot welds respectively with negative pole by positive pole, the making collector plate is processed the electrode group, and the battery can that this battery pack is arranged on aluminum is (among external dimensions: 36 φ * 120mm) and make that the negative pole collector plate is the end.The negative pole collector plate carries out means of spot welds at the bottom of jar, forming battery can is the structure of negative pole current-collecting terminals.Preparation has anodal current-collecting terminals, the battery cover of pressure relief valve, and anodal collector plate is connected through means of spot welds with anodal current-collecting terminals.Then, in the battery can that the electrode group is housed, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into,, make the cylinder battery through riveting molding sealed cell cover.The summation of anodal electrode area is 41.0 with respect to the ratio of the long-pending summation of case surface of battery, and electrode group occupation rate is 0.58.
" evaluation of battery "
Except using above-mentioned cylinder battery, likewise carry out cell evaluation with structure [1]～[5] embodiment 1.The structure of cell evaluation is shown in structure [1]～[5] table 3.
Structure [1]～[5] embodiment 6
Except the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % is come the alternative hexamethyl cyclotrisiloxane; With structure [1]～[5] embodiment 5 manufacture batteries likewise, and likewise carry out cell evaluation.The result is shown in structure [1]～[5] table 3.
Structure [1]～[5] embodiment 7
Except the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % is come the alternative hexamethyl cyclotrisiloxane,, and likewise carry out cell evaluation with structure [1]～[5] embodiment 5 manufacture batteries likewise.The result is shown in structure [1]～[5] table 3.
Structure [1]～[5] embodiment 8
Except the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % is come the alternative hexamethyl cyclotrisiloxane,, and likewise carry out cell evaluation with structure [1]～[5] embodiment 5 manufacture batteries likewise.The result is shown in structure [1]～[5] table 3.
Structure [1]～[5] comparative example 2
Except in structure [1]～[5] embodiment 5, nonaqueous electrolytic solution not being contained the hexamethyl cyclotrisiloxane,, and likewise carry out cell evaluation with structure [1]～[5] embodiment 5 manufacture batteries likewise.The result is shown in structure [1]～[5] table 3.
Structure [1]～[5] table 3
[table 65]
Result by structure [1]～[5] table 2 and structure [1]～[5] table 3 can know; In any battery; Through in nonaqueous electrolytic solution, containing specific compound, power output, capability retention, fail safe all are improved, even after cyclic test; The increase of DC resistance component is also little, and battery capacity and power output are fully kept.
Structure [6] embodiment 1
" making of nonaqueous electrolytic solution "
Under dry argon atmosphere, in 3: 3: 4 the mixed solvent of volume ratio of ethylene carbonate (EC), dimethyl carbonate (DMC) and the methyl ethyl carbonate (EMC) of purifying with the lithium hexafluoro phosphate (LiPF of the concentration dissolving intensive drying of 1mol/L 6).And make it contain the hexamethyl cyclotrisiloxane of 0.3 quality %.
" anodal making "
Positive active material is for adopting the synthetic lithium-transition metal composite oxide of following method, with composition formula LiMn 0.33Ni 0.33Co 0.33O 2Expression.With Mn: Ni: Co=1: 1: 1 molar ratio weighing is as the Mn of manganese raw material 3O 4, as the NiO of nickel raw material and as the Co (OH) of cobalt raw material 2, process slurry to wherein adding pure water, use circulating medium-stirring wet-type ball mill with the 0.2 μ m of solid constituent case of wet attrition to the median particle diameter in the slurry while stir.
Through spray dryer slurry is carried out spray drying, only comprised the roughly spherical granulation particle of the about 5 μ m of particle diameter of manganese raw material, nickel raw material, cobalt raw material.In the granulation particle that obtains, add the LiOH powder of median particle diameter 3 μ m; And the ratio of the molal quantity that makes Li and the total mole number of Mn, Ni and Co is 1.05; Mix with high-speed mixer, obtain the granulation particle of nickel raw material, cobalt raw material, manganese raw material and the mixed-powder of lithium raw material.Under circulation of air, 950 ℃ this mixed-powder fired 12 hours (warming and cooling rate is 5 ℃/minute) after, pulverize, the sieve through mesh 45 μ m obtains positive active material.The BET specific area of this positive active material is 1.2m 2/ g, average primary particle diameter are 0.8 μ m, median particle diameter d 50Be 4.4 μ m, tap density is 1.6g/cm 3
In N-crassitude ketone solvent, mix the cobalt acid lithium (LiCoO of 90 quality % as positive active material 2), 5 quality % as the acetylene black of electric conducting material and 5 quality % as the Kynoar (PVdF) of adhesive, process slurry.The slurry that obtains is coated on the aluminium foil two sides of thickness 15 μ m, and dry, roll into thickness 81 μ m with press, be cut into wide 100mm, the big or small positive electrode active material layer of long 100mm again, and have the shape of the uncoated part of wide 30mm, as positive pole.The density of positive electrode active material layer is 2.35g/cm 3, (thickness of the positive electrode active material layer of one side)/(thickness of collector body) is 2.2, L/ (2 * S 2) be 0.2.
" making of negative pole "
In order to prevent to sneak into oversize grain in the commercially available native graphite powder as the particulate carbonaceous material, use ASTM400 purpose sieve to sieve repeatedly 5 times.With the negative material that obtains like this as carbonaceous material (A).
The petroleum-type heavy oil that obtains when in carbonaceous material (A), mixing the naphtha pyrolysis; In non-active gas, implement 1300 ℃ carbonization treatment; Then; Obtain composite carbonaceous material through sinter is carried out hierarchical processing, as negative electrode active material, said composite carbonaceous material is on carbonaceous material (A) particle surface, to have coated the composite carbonaceous material with different crystalline carbonaceous material.During hierarchical processing,, use ASTM400 purpose sieve to sieve repeatedly 5 times in order to prevent to sneak into oversize grain.Can confirm that from carbon yield the negative electrode active material powder that obtains is coated by the low-crystalline carbonaceous material that with respect to 95 weight portion graphite is 5 weight.The rerum natura of negative electrode active material is shown in structure [6] table 1.
Structure [6] table 1
[table 66]
Figure BDA0000087738240003811
In the above-mentioned negative electrode active material of 98 weight portions, add 100 weight portions as the aqueous liquid dispersion (concentration of sodium carboxymethylcellulose is 1 quality %) of the sodium carboxymethylcellulose of thickener, 2 weight portions aqueous liquid dispersion (concentration of SBR styrene butadiene rubbers is 50 quality %) as the SBR styrene butadiene rubbers of adhesive; Mix with disperser, process slurry.The slurry that obtains is coated on the two sides of the rolled copper foil of thickness 10 μ m; And dry, using press to roll into thickness is 75 μ m, is cut into the active material layer of wide 104mm, long 104mm size again; And have the shape of the uncoated part of wide 30mm, as negative pole.The density of the negative electrode active material of this moment is 1.35g/cm 3, L/ (2 * S 2) be 0.19.
" making of battery "
With 32 positive poles and 33 negative pole alternate configurations, sandwich porous polyethylene sheet dividing plate (thickness is 25 μ m) between each electrode, carry out lamination.At this moment, make the positive active material face relative, and can not expose outside the negative electrode active material face with the negative electrode active material face.With this positive pole and negative pole separately uncoated harness each other, connect through means of spot welds with sheet metal as current-collecting terminals, make collector plate, process the electrode group.More than, the porous polyethylene sheet is at plugging hole more than 135 ℃.As the sheathing material of battery, use lamination successively that aluminium foil and the nylon membrane of polypropylene screen, thickness 0.04mm arranged and the sheet (amounting to thickness 0.1mm) that obtains, make polypropylene screen be positioned at inner face one side and be shaped to rectangular-shaped cup, as shell.The fusing point of this polypropylene screen is 165 ℃.With above-mentioned electrode group enclose in the shell and make current-collecting terminals from the unsealing part of cup upper end to exposing outside, inject the 20mL nonaqueous electrolytic solution, electrode is fully soaked into.Under reduced pressure the heat-sealing of cup upper end is sealed manufacture batteries to it.Battery is roughly square, and the electrode area summation of the positive pole of battery is 22.6 with respect to the ratio of case surface long-pending (the sheathing material surface area that does not contain heat seal lands) summation, (2 * S 1/ T) be 411.
" evaluation of battery "
(assay method of battery capacity)
To new battery without charge and discharge cycles; Under 25 ℃, the voltage range of 4.1V～3.0V with current value 0.2C (with the current value of 1 hour discharge rated capacity as 1C; Said rated capacity depends on the discharge capacity of 1 hour rate (one-hour-rate), down with) carry out 5 circulation initial stages and discharge and recharge.With the 5th circulation 0.2C discharge capacity at this moment (Ah) as " battery capacity ".The result of cell evaluation is shown in structure [6] table 3.
(assay method of DC resistance component)
Constant current through 0.2C under 25 ℃ of environment carries out charging in 150 minutes, applies the interchange of 10kHz, measures impedance, as " DC resistance component " (m Ω).The result of cell evaluation is shown in structure [6] table 3.
(assay method of initial stage power output)
Constant current through 0.2C under 25 ℃ of environment carries out charging in 150 minutes, discharges 10 seconds with 0.1C, 0.3C, 1.0C, 3.0C, 10.0C respectively, measures the 10th second voltage.The leg-of-mutton area that will be surrounded by current-voltage straight line and lower voltage limit (3V) as " initial stage power output " (W).The result of cell evaluation is shown in structure [6] table 3.
(cyclic test)
(assay method of durable back battery capacity, durable back DC resistance component, durable back power output)
Under 60 ℃ hot environment of the actual SC service ceiling temperature that is regarded as lithium secondary battery, carry out cyclic test.After charging to charging upper voltage limit 4.1V with the constant-current constant-voltage method of 2C, be discharged to final discharging voltage 3.0V, this charge and discharge cycles as 1 circulation, is carried out this circulation repeatedly and circulated until 500 with the constant current of 2C.Battery after finishing for cyclic test carries out 3 cycle charge-discharges with current value 0.2C under 25 ℃ of environment, with the 0.2C discharge capacity of its 3rd circulation as " durable battery capacity afterwards ".In addition,, measure DC resistance component,, carry out output test, as " durable back power output " as " durable back DC resistance component " for the battery after the cyclic test end.The result of cell evaluation is shown in structure [6] table 3.
(overcharge test)
Under 25 ℃ of environment, carry out overcharge test.Charge by the constant current of discharge condition (3V), observe its movement with 3C.Wherein, " valve work " expression vent valve work also discharges the phenomenon of nonaqueous electrolytic solution composition, " breaking " expression battery case with the fierce impetus break, content is forced the phenomenon that discharges.The result of cell evaluation is shown in structure [6] table 3.
(assay method of volume change)
Under 25 ℃ of environment, the battery volume of discharge condition (3V) is measured.Volume is submerged in battery in the ethanol and measures through in having graduated vessels, adding ethanol.With the ratio of the volume of the volume after the cyclic test before with respect to cyclic test as " volume change ".Evaluation result is shown in structure [6] table 3.
Structure [6] embodiment 2
Except the methanesulfonic acid trimethyl silyl ester that nonaqueous electrolytic solution contains 0.3 quality % is come the alternative hexamethyl cyclotrisiloxane,, and likewise carry out cell evaluation with embodiment 1 manufacture batteries likewise.The result is shown in structure [6] table 3.
Structure [6] embodiment 3
Except the phenyl dimethyl silicon fluoride that nonaqueous electrolytic solution contains 0.3 quality % is come the alternative hexamethyl cyclotrisiloxane,, and likewise carry out cell evaluation with structure [6] embodiment 1 manufacture batteries likewise.The result is shown in structure [6] table 3.
Structure [6] embodiment 4
Except the difluorophosphate that nonaqueous electrolytic solution contains 0.3 quality % is come the alternative hexamethyl cyclotrisiloxane,, and likewise carry out cell evaluation with structure [6] embodiment 1 manufacture batteries likewise.The result is shown in structure [6] table 3.
Structure [6] comparative example 1
Except in structure [6] embodiment 1, nonaqueous electrolytic solution not being contained the hexamethyl cyclotrisiloxane,, and likewise carry out cell evaluation with structure [6] embodiment 1 manufacture batteries likewise.The result is shown in structure [6] table 3.
Structure [6] table 2
[table 67]
No. Specific compound in the nonaqueous electrolytic solution
Embodiment 1 Hexamethyl cyclotrisiloxane
Embodiment 2 Methanesulfonic acid trimethyl silyl ester
Embodiment 3 Phenyl dimethyl silicon fluoride
Embodiment 4 Difluorophosphate
Comparative example 1 Do not have
Structure [6] table 3
[table 68]
Figure BDA0000087738240003841
Result by structure [6] table 3 can know; Through in nonaqueous electrolytic solution, containing specific compound; Initial stage power output, capability retention, fail safe are improved, even after cyclic test, also can fully keep battery capacity and power output, the variation of battery volume is also little.
Industrial applicibility
Purposes to lithium secondary battery of the present invention does not limit especially, can be used for known various uses.As concrete example, can enumerate bicycle, bicycle, ligthing paraphernalia, toy, game machine, clock and watch, electric tool, stroboscope, camera of notebook personal computer, an input type PC, mobile personal computer, e-book player (Electronic book player), portable phone, portable facsimile printer, portable copier, portable printer, head-telephone, video camera, LCD TV, convenient dust catcher, portable CD, mini formula disc player, wireless set, electronic memo, calculator, storage card, portable tape recorder, broadcast receiver, back-up source, motor, automobile, motorcycle, charged motivation etc.Lithium secondary battery of the present invention, owing to have big capacity, excellent life-span and high-output power, gas produces few, even fail safe is also high when overcharging, so in particularly requiring jumbo field, extensive use suitably.
Though above use the present invention and specific mode specify, to those skilled in the art, not breaking away from the intent of the present invention and scope, can to carry out various changes be conspicuous.And the application is based on following Japanese patent application, quotes by reference that they are whole.
Japan is special is willing to the 2005-331255 (applying date: on November 16th, 2005)
Japan is special is willing to the 2005-331362 (applying date: on November 16th, 2005)
Japan is special is willing to the 2005-331391 (applying date: on November 16th, 2005)
Japan is special is willing to the 2005-331477 (applying date: on November 16th, 2005)
Japan is special is willing to the 2005-331513 (applying date: on November 16th, 2005)
Japan is special is willing to the 2005-339794 (applying date: on November 25th, 2005)
Japan is special is willing to the 2006-019863 (applying date: on January 27th, 2006)
Japan is special is willing to the 2006-005622 (applying date: on January 13rd, 2005)
Japan is special is willing to the 2005-367747 (applying date: on December 21st, 2005)
Japan is special is willing to the 2005-377366 (applying date: on December 28th, 2005)
Japan is special is willing to the 2005-349052 (applying date: on December 2nd, 2005)
Japan is special is willing to the 2005-359061 (applying date: on December 13rd, 2005)
Japan is special is willing to the 2006-019879 (applying date: on January 27th, 2006)
Japan is special is willing to the 2006-013664 (applying date: on January 23rd, 2005)
Japan is special is willing to the 2005-314043 (applying date: on October 28th, 2005)
Japan is special is willing to the 2005-331585 (applying date: on November 16th, 2005)
Japan is special is willing to the 2005-305368 (applying date: on October 20th, 2005)
Japan is special is willing to the 2005-344732 (applying date: on November 29th, 2005)
Japan is special is willing to the 2005-343629 (applying date: on November 29th, 2005)
Japan is special is willing to the 2005-332173 (applying date: on November 16th, 2005)
Japan is special is willing to the 2005-305300 (applying date: on October 20th, 2005)
Japan is special is willing to the 2005-353005 (applying date: on December 7th, 2005)
Japan is special is willing to the 2005-314260 (applying date: on October 28th, 2005)
Japan is special is willing to the 2005-369824 (applying date: on December 22nd, 2005)
Japan is special is willing to the 2005-370024 (applying date: on December 22nd, 2005)
Description of drawings
[Fig. 1] is cross section scanning electron microscope (SEM) photo of the film cathode (1) that uses in embodiment 1～3 and the comparative example 1 of negative pole [7] (a).(b) be the photo that elements Si that electron probe microanalyzer (EPMA) obtains distributes in the mass concentration of film thickness direction that passes through of film cathode (1) that negative pole [7] are shown.(c) be the photo that Elements C that electron probe microanalyzer (EPMA) obtains distributes in the mass concentration of film thickness direction that passes through of film cathode (1) that anticathode [7] are shown.

Claims (13)

1. a secondary cell is used nonaqueous electrolytic solution; This electrolyte is to contain nonaqueous solvents and lithium salts at least and the nonaqueous electrolytic solution that forms; Wherein, This nonaqueous electrolytic solution contains at least a compound that is selected from the following substances, and its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises:
The fluorosilane compounds of formula (2) expression,
SiF xR 3 pR 4 qR 5 r (2)
In the general formula (2), R 3～R 5Can be the same or different, the organic group of expression carbon number 1～12, x representes 1～3 integer, p, q and r represent 0～3 integer respectively, and 1≤p+q+r≤3,
The compound of formula (3) expression,
Figure FDA0000087738230000011
In the general formula (3), R 6～R 8Can be the same or different, the organic group of expression carbon number 1～12, A representes the group that is made up of H, C, N, O, F, S, Si and/or P, and
The compound, nitrite, mono-fluor phosphate, acetate and the propionate that have the S-F key in the molecule;
And said nonaqueous electrolytic solution is the electrolyte that satisfies the arbitrary condition in following electrolyte [1]～electrolyte [9] that is selected from:
Electrolyte [1]: the nonaqueous solvents that constitutes electrolyte is the mixed solvent that contains ethylene carbonate at least, and ethylene carbonate is 1 capacity %～25 capacity % with respect to the ratio of nonaqueous solvents total amount;
Electrolyte [2]: the nonaqueous solvents that constitutes electrolyte contains at least a asymmetric linear carbonate, and this asymmetric linear carbonate is shared in whole nonaqueous solventss, and to contain proportional be 5 volume %～90 volume %;
Electrolyte [3]: the nonaqueous solvents that constitutes electrolyte contains at least a chain carboxylate;
Electrolyte [4]: it is the solvent more than 70 ℃ that the nonaqueous solvents of formation electrolyte contains flash-point, and its content is more than the 60 capacity % of whole nonaqueous solventss;
Electrolyte [5]: contain LiN (C nF 2n+1SO 2) 2(in the formula, n is 1～4 integer) and/or two (oxalate closes) lithium borate are as the lithium salts that constitutes electrolyte;
Electrolyte [6]: the lithium salts that constitutes electrolyte is fluorine-containing lithium salts, and in whole nonaqueous electrolytic solutions, contains the hydrogen fluoride (HF) of 10ppm～300ppm;
Electrolyte [7]: in electrolyte, contain vinylene carbonate, the content of this vinylene carbonate is the scope of the 0.001 quality %～3 quality % of electrolyte gross mass;
Electrolyte [8]: in electrolyte, also contain at least a compound in the compound that is selected from general formula (4) expression, the heterocyclic compound that contains nitrogen and/or sulphur, cyclic carboxylic esters, the fluorine-containing cyclic carbonate; Its content in whole nonaqueous electrolytic solutions is the scope of 0.001 quality %～5 quality %
Figure FDA0000087738230000021
In the general formula (4), R 9～R 12Can be the same or different the group that expression is made up of at least a element that is selected among H, C, N, O, F, S and the P;
Electrolyte [9]: in electrolyte, also containing overcharges prevents agent.
2. the described secondary cell of claim 1 is used nonaqueous electrolytic solution; Wherein, Said nonaqueous electrolytic solution contains 0.01 quality %～5 quality % and is selected from least a above-claimed cpd in the following substances, and said material comprises: the compound, nitrite, mono-fluor phosphate, acetate and the propionate that have the S-F key in the compound of the fluorosilane compounds of general formula (2) expression, general formula (3) expression, the molecule.
3. a secondary cell is used nonaqueous electrolytic solution, and it contains lithium salts and forms in nonaqueous solvents, wherein,
Said nonaqueous electrolytic solution contains difluorophosphoric acid salt;
Said nonaqueous solvents is the mixed solvent that contains ethylene carbonate, dimethyl carbonate and methyl ethyl carbonate at least;
Also optional containing is selected from LiN (CF in the said nonaqueous electrolytic solution 3SO 2) 2, two (oxalate closes) lithium borate, vinylene carbonate, 1, more than one compounds in 3-third sultone, fluorine ethylene carbonate, the cyclohexyl benzene.
4. lithium secondary battery, this lithium secondary battery comprises at least: anodal and negative pole clipped the micro-porous film dividing plate and the electrode group that constitutes and in nonaqueous solvents, contain lithium salts and the nonaqueous electrolytic solution that forms, and they is contained in the battery case, wherein,
Said positive pole and said negative pole form active material layer respectively on collector body, this active material layer contains can occlusion and emit the active material of lithium ion;
This nonaqueous electrolytic solution contains at least a compound that is selected from the following substances, and its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises:
The fluorosilane compounds of formula (2) expression,
SiF xR 3 pR 4 qR 5 r (2)
In the general formula (2), R 3～R 5Can be the same or different, the organic group of expression carbon number 1～12, x representes 1～3 integer, p, q and r represent 0～3 integer respectively, and 1≤p+q+r≤3,
The compound of formula (3) expression,
Figure FDA0000087738230000031
In the general formula (3), R 6～R 8Can be the same or different, the organic group of expression carbon number 1～12, A representes the group that is made up of H, C, N, O, F, S, Si and/or P, and
The compound, nitrite, mono-fluor phosphate, acetate and the propionate that have the S-F key in the molecule;
And said nonaqueous electrolytic solution is the electrolyte that satisfies the arbitrary condition in following electrolyte [1]～electrolyte [9] that is selected from:
Electrolyte [1]: the nonaqueous solvents that constitutes electrolyte is the mixed solvent that contains ethylene carbonate at least, and ethylene carbonate is 1 capacity %～25 capacity % with respect to the ratio of nonaqueous solvents total amount;
Electrolyte [2]: the nonaqueous solvents that constitutes electrolyte contains at least a asymmetric linear carbonate, and this asymmetric linear carbonate is shared in whole nonaqueous solventss, and to contain proportional be 5 volume %～90 volume %;
Electrolyte [3]: the nonaqueous solvents that constitutes electrolyte contains at least a chain carboxylate;
Electrolyte [4]: it is the solvent more than 70 ℃ that the nonaqueous solvents of formation electrolyte contains flash-point, and its content is more than the 60 capacity % of whole nonaqueous solventss;
Electrolyte [5]: contain LiN (C nF 2n+1SO 2) 2(in the formula, n is 1～4 integer) and/or two (oxalate closes) lithium borate are as the lithium salts that constitutes electrolyte;
Electrolyte [6]: the lithium salts that constitutes electrolyte is fluorine-containing lithium salts, and in whole nonaqueous electrolytic solutions, contains the hydrogen fluoride (HF) of 10ppm～300ppm;
Electrolyte [7]: in electrolyte, contain vinylene carbonate, the content of this vinylene carbonate is the scope of the 0.001 quality %～3 quality % of electrolyte gross mass;
Electrolyte [8]: in electrolyte, also contain at least a compound in the compound that is selected from general formula (4) expression, the heterocyclic compound that contains nitrogen and/or sulphur, cyclic carboxylic esters, the fluorine-containing cyclic carbonate; Its content in whole nonaqueous electrolytic solutions is the scope of 0.001 quality %～5 quality %
Figure FDA0000087738230000041
In the general formula (4), R 9～R 12Can be the same or different the group that expression is made up of at least a element that is selected among H, C, N, O, F, S and the P;
Electrolyte [9]: in electrolyte, also containing overcharges prevents agent.
5. the described lithium secondary battery of claim 4; Wherein, Said nonaqueous electrolytic solution contains 0.01 quality %～5 quality % and is selected from least a above-claimed cpd in the following substances, and said material comprises: the compound, nitrite, mono-fluor phosphate, acetate and the propionate that have the S-F key in the compound of the fluorosilane compounds of general formula (2) expression, general formula (3) expression, the molecule.
6. lithium secondary battery, this lithium secondary battery comprises at least: between positive pole and negative pole, clips the micro-porous film dividing plate and the electrode group that constitutes and in nonaqueous solvents, contain lithium salts and the nonaqueous electrolytic solution that forms, and they is contained in the battery case, wherein,
Said positive pole and said negative pole form active material layer respectively on collector body, this active material layer contains can occlusion and emit the active material of lithium ion;
This nonaqueous electrolytic solution contains at least a compound that is selected from the following substances, and its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises:
SiF xR 3 pR 4 qR 5 r (2)
In the general formula (2), R 3～R 5Can be the same or different, the organic group of expression carbon number 1～12, x representes 1～3 integer, p, q and r represent 0～3 integer respectively, and 1≤p+q+r≤3,
The compound of formula (3) expression,
Figure FDA0000087738230000042
In the general formula (3), R 6～R 8Can be the same or different, the organic group of expression carbon number 1～12, A representes the group that is made up of H, C, N, O, F, S, Si and/or P, and
The compound, nitrite, mono-fluor phosphate, acetate and the propionate that have the S-F key in the molecule;
And said negative pole is any one negative pole that is selected from following negative pole [1]～negative pole [10]:
Negative pole [1]: contain crystallinity is different more than 2 kinds carbonaceous material negative pole as negative electrode active material;
Negative pole [2]: contain the negative pole of amorphous carbonaceous as negative electrode active material; Said amorphous carbonaceous is more than the 0.337nm through the interplanar distance (d002) of (002) face that wide-angle x-ray diffraction is measured; Crystallite size (Lc) is below the 80nm, adopt that the argon laser Raman spectroscopy measures with 1360cm -1Peak intensity with respect to 1580cm -1The Raman R value of ratio definition of peak intensity be more than 0.2;
Negative pole [3]: contain the negative pole of metal oxide as negative electrode active material, said metal oxide contains can occlusion and emit the titanium of lithium;
Negative pole [4]: contain the negative pole of carbonaceous material as negative electrode active material, the circularity of said carbonaceous material is more than 0.85, and surface functional group amount O/C value is 0～0.01;
Negative pole [5]: contain the negative pole of different orientation carbon complex as negative electrode active material, said different orientation carbon complex contains the different carbonaceous material of orientation more than 2 kinds;
Negative pole [6]: contain the negative pole of graphite matter carbon particle as negative electrode active material; The circularity of said graphite matter carbon particle is more than 0.85; The interplanar distance (d002) of (002) face of measuring through wide-angle x-ray diffraction is lower than 0.337nm, adopt that the argon laser Raman spectroscopy measures with 1360cm -1Peak intensity with respect to 1580cm -1The Raman R value of ratio definition of peak intensity be 0.12～0.8;
Negative pole [7]: contain the negative pole of the following negative electrode active material that comprises multielement (C) as negative electrode active material; The said negative electrode active material (C) that comprises multielement contains at least a in the lithium occlusion metal (A) that is selected from Al, Pb, Zn, Sn, Bi, In, Mg, Ga, Cd, Ag, Si, B, Au, Pt, Pd and Sb and/or the lithium occlusion alloy (B), and contains C and/or N as element Z;
Negative pole [8]: contain the negative pole of the negative electrode active material more than 2 kinds of different in kind as negative electrode active material;
Negative pole [9]: containing tap density is 0.1g/cm 3More than, and the micropore volume of the particle of the scope that is equivalent to diameter 0.01 μ m～1 μ m of employing mercury porosimeter mensuration is the negative pole of the above negative electrode active material of 0.01mL/g;
Negative pole [10]: be charged to 60% o'clock of nominal capacity of this negative pole, the reaction resistance that is produced by the opposed battery of negative pole is the negative pole below 500 Ω.
7. the described lithium secondary battery of claim 6; Wherein, Nonaqueous electrolytic solution contains at least a compound that is selected from the following substances; Its content is 0.01 quality %～5 quality %, and said material comprises: the compound, nitrite, mono-fluor phosphate, acetate and the propionate that have the S-F key in the compound of the fluorosilane compounds of general formula (2) expression, general formula (3) expression, the molecule.
8. lithium secondary battery, this lithium secondary battery comprises at least: anodal and negative pole clipped the micro-porous film dividing plate and the electrode group that constitutes and in nonaqueous solvents, contain lithium salts and the nonaqueous electrolytic solution that forms, and they is contained in the battery case, wherein,
Said positive pole and said negative pole form active material layer respectively on collector body, this active material layer contains can occlusion and emit the active material of lithium ion;
This nonaqueous electrolytic solution contains at least a compound that is selected from the following substances, and its content in whole nonaqueous electrolytic solutions is more than the 10ppm, and said material comprises:
The fluorosilane compounds of formula (2) expression,
SiF xR 3 pR 4 qR 5 r (2)
In the general formula (2), R 3～R 5Can be the same or different, the organic group of expression carbon number 1～12, x representes 1～3 integer, p, q and r represent 0～3 integer respectively, and 1≤p+q+r≤3,
The compound of formula (3) expression,
Figure FDA0000087738230000061
In the general formula (3), R 6～R 8Can be the same or different, the organic group of expression carbon number 1～12, A representes the group that is made up of H, C, N, O, F, S, Si and/or P, and
The compound, nitrite, mono-fluor phosphate, acetate and the propionate that have the S-F key in the molecule;
And this secondary cell has any character that is selected from following structure [1]～structure [6]:
Structure [1]: the electrode area summation of the said positive pole area ratio long-pending with respect to the case surface of said secondary cell is more than 20 times;
Structure [2]: the DC resistance component of said secondary cell is below 20 milliohms (m Ω);
Structure [3]: being contained in the electric capacity that the battery key element in the battery case of said secondary cell had is more than 3 ampere-hours (Ah);
Structure [4]: the positive pole of said secondary cell and the collector body of negative pole are processed by metal material respectively, and the metal material of said collector body be used for that electric current is fetched into outside electric conductor and weld through any method of slot welding, high-frequency welding or ultrasonic bonding;
Structure [5]: the shell of said secondary cell is an aluminum or aluminum alloy;
Structure [6]: the sheathing material of the above-mentioned battery case of formation of said secondary cell is following sheathing material: at least a portion of the inner face side of inside battery comprises the sheet material that uses thermoplastic resin and form; When holding said electrode group, can also seal each other and said electrode group is sealed through making said thermoplastic resin.
9. the described lithium secondary battery of claim 8; Wherein, Said nonaqueous electrolytic solution contains 0.01 quality %～5 quality % and is selected from least a above-claimed cpd in the following substances, and said material comprises: the compound, nitrite, mono-fluor phosphate, acetate and the propionate that have the S-F key in the compound of the fluorosilane compounds of general formula (2) expression, general formula (3) expression, the molecule.
10. Battery pack, it is connected in series 5 above claims 8 or 9 described lithium secondary batteries and forms.
11. a Battery pack, it is the Battery pack that a plurality of claims 8 or 9 described lithium secondary batteries are formed by connecting, and wherein has to be used to make battery to remain on the cooling device below the uniform temperature.
12. claim 8 or 9 described lithium secondary batteries, this lithium secondary battery is used for following purposes: be installed in vehicle, its power supplies to the drive system of vehicle at least.
13. the described Battery pack of claim 10 or claim 11, this Battery pack is used for following purposes: be installed in vehicle, its power supplies to the drive system of vehicle at least.
CN2011102544054A 2005-10-20 2006-10-19 Lithium secondary battery and use therein nonaqueous electrolytic solution Pending CN102324567A (en)

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Application publication date: 20120118