CN100490222C - Anode active material and battery using the same - Google Patents

Anode active material and battery using the same Download PDF

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CN100490222C
CN100490222C CNB2005101070341A CN200510107034A CN100490222C CN 100490222 C CN100490222 C CN 100490222C CN B2005101070341 A CNB2005101070341 A CN B2005101070341A CN 200510107034 A CN200510107034 A CN 200510107034A CN 100490222 C CN100490222 C CN 100490222C
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active core
negative active
shell material
carbon
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CN1755968A (en
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水谷聪
井上弘
山口晃
北昭宪
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Murata Northeast China
Murata Manufacturing Co Ltd
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Sony 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

A battery with a high capacity and superior cycle characteristics and an anode active material used in the battery are provided. An anode includes an anode active material capable of reacting with lithium. The anode active material includes at least tin, cobalt and carbon as elements, and the carbon content is within a range from 9.9 wt% to 29.7 wt% inclusive, and the ratio of cobalt to the total of tin and cobalt is within a range from 30 wt% to 70 wt% inclusive. Thereby, while a high capacity is maintained, cycle characteristics can be improved.

Description

The battery of negative active core-shell material and this negative active core-shell material of use
Technical field
The present invention relates to comprise that tin (Sn), cobalt (Co) and carbon (C) are as the negative active core-shell material of element with use the battery of this negative active core-shell material.
Background technology
In recent years, a large amount of mancarried electronic aids, for example camcorder, cellular phone and laptop computer occur, and have carried out reducing the trial of its size and weight.Actively promoted at the battery that improves as the portable power supplies of electronic equipment, particularly as the research and development of the energy density of the secondary cell of Primary Component.In these batteries, to compare with nickel-cadmium cell with the aqueous electrolyte secondary cell such as the lead-acid battery of correlation technique, rechargeable nonaqueous electrolytic battery (for example lithium rechargeable battery) can obtain high-energy-density, has therefore studied the improvement of battery in all respects.
As the negative active core-shell material that is used for lithium rechargeable battery, be extensive use of material with carbon element such as ungraphitised carbon or graphite with relative high power capacity and excellent cycle characteristics.Yet, consider in recent years the demand of high power capacity more, the capacity of further raising material with carbon element has been proposed challenge.
Under this background, developed by choosing the technology (for example, disclosing flat 8-315825) that the material of wanting carbonization and formation condition obtain the more high power capacity of material with carbon element referring to Japanese Unexamined Patent Application.Yet when using this material with carbon element, negative pole has the discharge voltage to lithium (Li) 0.8V to 1.0V, and when battery comprises material with carbon element, the discharge voltage of battery reduces, thus hardly expectability to the remarkable improvement of energy content of battery density.In addition, the shortcoming of existence is that the charging and discharging curve shape lags behind greatly, and the energy efficiency of therefore each charge and discharge cycles is low.
On the other hand, as negative pole, studied by with the metal of some kinds and the lithium electrochemical alloying is that form and alloy material that have reversible production (produce) and decomposability with capacity higher than material with carbon element.For example, developed and used the negative pole with high power capacity of Li-Al alloy or Sn alloy, and developed the negative pole with high power capacity (for example, referring to U.S. Patent No. 4950566) that comprises the Si alloy.
Yet there are a very big shortcoming in Li-Al alloy, Sn alloy or Si alloy: cycle characteristics is poor especially, because these alloys are according to charging and discharge expansion or contraction, so when repeating charge and discharge cycles, negative pole is by efflorescence at every turn.
Therefore, be to improve cycle characteristics, considered to improve form the alloy that comprises tin or silicon (Si) with the technology that prevents alloy and expand (for example, referring to " Journal of The Electrochemical Society ", 1999, No.146, p.414).In addition, Mg has been proposed 2Si etc. (for example, referring to " Journal of TheElectrochemical Society ", 1999, No.146, p.4401).
Summary of the invention
Yet even use these technology, the effect of improving cycle characteristics is also not enough, so the fact is not bring into play the advantage of the negative pole with high power capacity that comprises alloy material fully.
Consider the above, battery with high power capacity and excellent cycle characteristics and the negative active core-shell material that is used for this battery need be provided.
According to an embodiment of the invention, provide and comprise that tin, cobalt and carbon are as the negative active core-shell material of element at least, wherein carbon content is 9.9 weight % to 29.7 weight % (comprising end points), and cobalt is 30 weight % to 70 weight % (comprising end points) to the ratio of tin and cobalt total amount.
According to an embodiment of the invention, a kind of battery is provided, comprise positive pole, negative pole and electrolyte, wherein negative pole comprises negative active core-shell material, this negative active core-shell material comprises that tin, cobalt and carbon are as element at least, and the content of carbon in negative active core-shell material is 9.9 weight % to 29.7 weight % (comprising end points), and cobalt is 30 weight % to 70 weight % (comprising end points) to the ratio of tin and cobalt total amount.
In negative active core-shell material, as element, comprise tin, so can obtain high power capacity according to embodiment of the present invention.In addition,, comprise cobalt, and cobalt is 30 weight % to 70 weight % (comprising end points) to the ratio of tin and cobalt total amount, when keeping high power capacity, can improves cycle characteristics like this as element.In addition,, comprise carbon, and the content of carbon is 9.9 weight % to 29.7 weight % (comprising end points), can further improves cycle characteristics like this as element.Therefore, in the battery that uses this negative active core-shell material, high power capacity can be obtained, and excellent cycle characteristics can be obtained according to embodiment of the present invention.
In addition, when silicon is included in the negative active core-shell material as element, can obtain more high power capacity.
In addition, further be included in the negative active core-shell material as element when being selected from least a of indium (In), niobium (Nb), germanium (Ce), titanium (Ti), molybdenum (Mo), aluminium (Al), phosphorus (P), gallium (Ga) and bismuth (Bi), and their content is 14.9 weight % or when lower, can further improve cycle characteristics, and more specifically, when content is 2.4 weight % or more for a long time, can obtain higher effect.
In addition, when iron further is included in the negative active core-shell material as element, and the content of ferro element is 0.3 weight % to 5.9 weight % when (comprising end points), can further improve capacity and cycle characteristics.
In addition, when the derivative of the cyclic carbonate of halogen atom is included in the electrolyte, the decomposition reaction of solvent in negative pole can be prevented, therefore cycle characteristics can be further improved.
Of the present invention other and further purpose, characteristics and advantage will be more apparent from following description.
Description of drawings
Fig. 1 is the sectional view according to the secondary cell of one embodiment of the present invention;
Fig. 2 is the part amplification sectional view of the spiral winding electrode in the secondary cell shown in Figure 1;
Fig. 3 is the decomposition diagram according to another secondary cell of embodiment of the present invention;
Fig. 4 is the sectional view of the spiral winding electrode chosen along Fig. 3 line I-I;
Fig. 5 is the sectional view according to another secondary cell of embodiment of the present invention;
Fig. 6 is the figure that shows an example at the negative active core-shell material peak that forms among the embodiment, and it obtains by the x-ray photoelectron spectroscopy method;
Fig. 7 is the sectional view of the Coin-shaped battery that forms in one embodiment;
Fig. 8 is for showing the graph of a relation between carbon content, capability retention and the initial charge capacity in the negative active core-shell material;
Fig. 9 is the figure that is presented at an example at the negative active core-shell material peak that forms in the comparative example, and it obtains by the x-ray photoelectron spectroscopy method;
Figure 10 is for showing that cobalt is to the graph of a relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 11 is for showing that cobalt is to another figure of the relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 12 is for showing that cobalt is to another figure of the relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 13 is the graph of a relation between Ti content and the capability retention in the demonstration negative active core-shell material;
Figure 14 is the graph of a relation between bi content and the capability retention in the demonstration negative active core-shell material;
Figure 15 is for showing another figure of the relation between carbon content, capability retention and the initial charge capacity in the negative active core-shell material;
Figure 16 is for showing that cobalt is to another figure of the relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 17 is for showing that cobalt is to another figure of the relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 18 is for showing that cobalt is to another figure of the relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 19 is another figure of the relation between Ti content and the capability retention in the demonstration negative active core-shell material;
Figure 20 is for showing another figure of the relation between carbon content, capability retention and the initial charge capacity in the negative active core-shell material;
Figure 21 is for showing that cobalt is to another figure of the relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 22 is for showing that cobalt is to another figure of the relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 23 is for showing that cobalt is to another figure of the relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 24 is for showing the graph of a relation between iron content, capability retention and the initial charge capacity in the negative active core-shell material;
Figure 25 is another figure of the relation between Ti content and the capability retention in the demonstration negative active core-shell material;
Figure 26 is another figure of the relation between bi content and the capability retention in the demonstration negative active core-shell material;
Figure 27 is for showing another figure of the relation between carbon content, capability retention and the initial charge capacity in the negative active core-shell material;
Figure 28 is for showing that cobalt is to another figure of the relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 29 is for showing that cobalt is to another figure of the relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 30 is for showing that cobalt is to another figure of the relation between ratio, capability retention and the initial charge capacity of the total amount of tin and cobalt in the negative active core-shell material;
Figure 31 is for showing another figure of the relation between iron content, capability retention and the initial charge capacity in the negative active core-shell material; With
Figure 32 is another figure of the relation between Ti content and the capability retention in the demonstration negative active core-shell material.
Embodiment
Describe in detail preferred embodiment below with reference to the accompanying drawings.
(first execution mode)
According to the negative active core-shell material of first embodiment of the invention can with reactions such as lithium, and comprise that tin and cobalt are as element.Because the tin of per unit mass and lithium reacting dose height are so can obtain high power capacity.In addition, owing to only when comprising tin, be difficult to obtain enough cycle characteristicss; Yet, when also comprising cobalt, can improve cycle characteristics.
In the ratio of cobalt to the total amount of tin and cobalt, cobalt content is preferably 30 weight % to 70 weight % (comprising end points), and more preferably 30 weight % to 60 weight % (comprising end points).When this ratio was low, cobalt content descended, and therefore was difficult to obtain enough cycle characteristicss.On the other hand, when this ratio was higher, tin content reduced, and therefore, was difficult to obtain negative material such as the higher capacity of material with carbon element than correlation technique.
This negative active core-shell material also comprises carbon as element except tin and cobalt, because when comprising carbon, can further improve cycle characteristics.Carbon content is preferably 9.9 weight % to 29.7 weight % (comprising end points), and more preferably 14.9 weight % to 29.7 weight % (comprising end points), and more preferably 16.8 weight % to 24.8 weight % (comprising end points) are because can obtain higher effect in this scope.
In some cases, negative active core-shell material preferably includes silicon as element except top element, because the silicon of per unit mass and lithium reacting dose height, and can further improve capacity.Silicone content is preferably 0.5 weight % to 7.9 weight % (comprising end points), because when content is low, improves the effect deficiency of capacity, and when content was higher, negative active core-shell material made cycle characteristics descend according to charging and discharge efflorescence thus.
In some cases, negative active core-shell material preferably further comprises and is selected from least a as element of indium, niobium, germanium, titanium, molybdenum, aluminium, phosphorus, gallium and bismuth, because can further improve cycle characteristics.The content of these elements is preferably 14.9 weight % or lower, more preferably 2.4 weight % to 14.9 weight % (comprising end points), more preferably 4.0 weight % to 12.9 weight % (comprising end points), because when content is low, be difficult to obtain enough effects, and when content was higher, tin content descended, therefore be difficult to obtain enough capacity, and cycle characteristics descends.
In addition, negative active core-shell material has low crystalline phase or amorphous phase.This be mutually can with the reacting phase (reactive phase) of reaction such as lithium, and, can obtain excellent cycle characteristics by this reacting phase.The half width of the diffraction maximum of this phase that obtains by X-ray diffraction is preferably 1.0 ° or bigger at the angle of diffraction 2 θ places, therein the CuK alpha ray is used as specific X-ray, and under the situation of 1 °/minute of sweep speed.Because lithium etc. can steadily insert or deviate from, and can further reduce electrolytical reactivity.
The diffraction maximum that obtains by X-ray diffraction whether be equivalent to can with the reacting phase of reaction such as lithium, can be easily definite by the x-ray diffraction pattern that relatively carries out before and after the electrochemical reaction with lithium etc.For example, during the position of diffraction maximum, this diffraction maximum was equivalent to carry out with lithium etc. the reacting phase of electrochemical reaction after the diffraction maximum position before carrying out electrochemical reaction with lithium etc. was different from electrochemical reaction.In negative active core-shell material, low crystallization reaction mutually or the diffraction maximum of amorphous reacting phase can be in 2 θ=20 for example ° to 50 ° of scopes, detect.Low crystallization reaction phase or amorphous reacting phase comprise for example above-mentioned each element, and it is believed that this reacting phase mainly becomes low crystallization or unbodied by carbon.
This negative active core-shell material also can have the phase that comprises simple substance or each element of a part except low crystalline phase or amorphous phase.
In addition, in negative active core-shell material, as at least a portion of the carbon of element preferably with metallic element or metalloid element coupling as other element.It is believed that cycle characteristics descends results from gathering or crystallization such as tin; Yet, when carbon and other element coupling, can prevent this gathering or crystallization.
As the method for measurement of detection elements coupling state, for example use x-ray photoelectron spectroscopy method (XPS).This XPS is for (to be purchased in the instrument by apply soft x-rays to specimen surface, use Al-K alpha ray or Mg-K alpha ray) to measure photoelectronic kinetic energy, be determined at and count apart from specimen surface that element in the zone of nanometer is formed and the method for the coupling state of element from the specimen surface emission.
The binding energy of the inner orbit electronics of element changes with respect to the charge density on the element in first approximation.For example when the charge density of carbon because of interacting when reducing with near carbon element, outer-shell electron such as the minimizing of 2p electronics, so the Is electronics of carbon is fettered strongly by shell.In other words, when the charge density of element reduced, binding energy raise.In XPS, when binding energy raise, the peak moved to high-energy district more.
In XPS, for graphite, in instrument, observe 1s track (Cls) peak of carbon at the 284.5eV place, in this instrument, carry out energy calibration to observe 4f track (Au4f) peak of gold atom at the 84.0eV place.In addition, under the situation of the carbon of surface contamination, observe the peak at the 284.8eV place.On the other hand, therein under the situation that the charge density of carbon raises, for example therein under the situation of carbon and metallic element or metalloid element coupling, observe the Cls peak being lower than the 284.5eV district.In other words, in being lower than the zone of 284.5eV, observe therein under the situation at peak of complex wave of the Cls that in negative active core-shell material, obtains, be included in the negative active core-shell material to small part carbon and metallic element or metalloid element coupling as other element.
In the XPS measuring of anticathode active material, under the situation that negative active core-shell material is covered by the carbon of surface contamination, preferably with the slight sputtering surface of argon-ion gun that is connected to the XPS instrument.In addition, place under the situation of (as described later) in the battery cathode at the negative active core-shell material that will measure, after battery being taken apart the taking-up negative pole, this negative pole can clean with volatile solvent such as dimethyl carbonate, can remove low voc solvent and the electrolytic salt on the negative terminal surface.This sampling is preferably carried out in inert atmosphere.
In addition, in XPS measuring, for example the Cls peak is used to calibrate the energy axes of spectrum.Usually, surface contamination carbon is present on the material surface, so the Cls peak of surface contamination carbon is fixed on the 284.8eV place, and with this peak as energy reference (reference).In XPS measuring, the wave mode at Cls peak obtains with the shape at the peak of the peak that comprises surface contamination carbon and the carbon in the negative active core-shell material, for example is purchased the software analysis waveform by using like this, with the peak of the peak of surface contamination carbon and the carbon in the negative active core-shell material separately.In analysis waveform, the peak position that will be present in minimum binding energy one side is as energy reference (284.8eV).
Negative active core-shell material is by forming mixture with all elements material mixing, this mixture is melted in electric furnace, Efco-Northrup furnace, arc furnace etc., then this mixture solidified is formed, or by various atomizations such as gas atomization or water atomization, various roll extrusion (roll) method, or use the method for mechanico-chemical reaction such as mechanical alloying method or mechanical milling method to form.Negative active core-shell material preferably forms by the method for wherein using mechanico-chemical reaction, because negative active core-shell material can have low crystal structure or impalpable structure.In the method, for example can use planetary ball mill.
As material, can use the mixture of the simple substance of each element; Yet, preferably use the alloy of the outer part element of de-carbon.Because when carbon being added in this alloy by the synthetic negative active core-shell material of machine-alloying, this negative active core-shell material can have low crystal structure or impalpable structure, and can reduce the reaction time.The shape of material can be powder or piece.
For carbon as material, can use one or both or multiple material with carbon element, but but as not-(fired) HMW organic compound object, active carbon and the carbon black of graphitized carbon graphitized carbon, graphite, various RESEARCH OF PYROCARBON, various coke, various vitreous carbon, roasting.Wherein, various coke comprise pitch coke, needle coke, petroleum coke etc., and the HMW organic compound object of sintering is high-molecular weight compounds such as phenolic resins, furane resins etc. by burning carbonization under proper temperature.This material with carbon element can have fiber shape, sphere, particle shape or scales of skin that peel off shape.
For example, as described below, negative active core-shell material is used for secondary cell.
(first battery)
Fig. 1 provides the sectional view of first secondary cell.This secondary cell is so-called cylinder type, and comprises that the electrode body 20 of screw winding, this electrode body 20 comprise bar shaped anodal 21 and bar shaped negative pole 22, and it has 23 times screw windings of barrier film between it by lamination and in hollow basically cylindrical battery shell 11.Battery case 11 is for example made by the iron of nickel plating.An end portion sealing of battery case 11, the other end opens wide.Electrolyte solution (it is a liquid electrolyte) is injected battery case 11, use electrolyte solution impregnation barrier film 23 thus.In addition, a pair of insulation board 12 and 13 are set, so that the electrode body 20 of screw winding is clamped in therebetween in the direction perpendicular to peripheral coiling surface.
In the open end part of battery case 11, by by liner 17 calkings, relief valve mechanism 15 and the PTC device (positive temperature coefficient device) 16 battery cover 14 being installed and being configured in battery cover 14 inside, and sealed cell shell 11 inside.Battery cover 14 is by for example making with battery case 11 identical materials.Relief valve mechanism 15 is electrically connected with battery cover 14 through PTC device 16, and when inner pressure of battery was higher than a certain limit because of internal short-circuit or the outside heat that applies are increased to, disc plate 15A returned and scratches (flip) so that be electrically connected disconnection between battery cover 14 and the spiral winding electrode 20.When temperature raise, the PTC device 16 resistance limits electric current by increasing so can prevent the generation of the abnormal heat that causes because of electric current greatly.Liner 17 is for example made by insulating material, and its surface bitumen coated.
For example centrepin 24 is inserted electrode body 20 centers of screw windings.To be connected to the positive pole 21 of the electrode body 20 of screw winding by the positive wire 25 that aluminium etc. is made, and the negative wire that nickel (Ni) etc. is made is connected to negative pole 22.Positive wire 25 is soldered to relief valve mechanism 15 so that it is electrically connected with battery cover 14, and negative wire 26 is welded and be electrically connected to battery case 11.
Fig. 2 has showed the part enlarged drawing of the spiral winding electrode 20 shown in Fig. 1.Anodal 21 comprise plus plate current-collecting body 21A that for example has a pair of opposed facing surface and the anode active material layer 21B that is disposed on this plus plate current-collecting body 21A one or both sides.Plus plate current-collecting body 21A is made by for example metal forming such as aluminium foil.If anode active material layer 21B comprises one or both or the multiple positive electrode active materials that for example can insert and deviate from lithium and necessary, electric conductor such as material with carbon element and binding agent such as polyvinylidene fluoride.
As the positive electrode active materials that can insert and deviate from lithium, for example use metal sulfide or the metal oxide that does not comprise lithium, as titanium sulfide (TiS 2), molybdenum sulfide (MoS 2), selenizing niobium (NbSe 2) or vanadium oxide (V 2O 5).In addition, use comprises Li xMO 2The lithium composite xoide of (wherein M represents one or more transition metal, and the value of x depends on the charging and discharging state of battery, and usually in 0.05≤x≤1.10 scopes) is as key component.As the transition metal M of lithium composite xoide, preferred cobalt, nickel or manganese (Mn).The object lesson of this lithium composite xoide comprises LiCoO 2, LiNiO 2, Li xNi yCo 1-yO 2(wherein x and y value depend on the charging and discharging state of battery, and usually respectively in 0＜x＜1 and 0＜y＜1 scope), have the complex Li-Mn-oxide of spinel structure etc.
Negative pole 22 comprises negative current collector 22A that for example has a pair of opposed facing surface and the anode active material layer 22B that is disposed on this negative current collector 22A one or both sides.Negative current collector 21A is made by for example metal forming such as Copper Foil.
Anode active material layer 22B comprises for example according to the negative active core-shell material of execution mode with as if necessity, binding agent such as polyvinylidene fluoride.When the negative active core-shell material according to execution mode was included in the secondary cell, this secondary cell can obtain high power capacity, and can improve the cycle characteristics of secondary cell.Anode active material layer 22B also can comprise other negative active core-shell material or other material such as electric conductor except the negative active core-shell material according to execution mode.As other negative active core-shell material, for example enumerate the material with carbon element that can insert and deviate from lithium.This material with carbon element is preferred, because can improve charge, and this material with carbon element also plays the effect of electric conductor.As this material with carbon element, for example enumerate and the identical materials of when forming negative active core-shell material, using.
Material with carbon element is preferably 1 weight % to 95 weight % (comprising end points) with ratio according to the negative active core-shell material of execution mode.Because when the ratio of material with carbon element surpassed this scope, the conductivity of negative pole 22 descended, and when the ratio of material with carbon element was higher than this scope, battery capacity descended.
Barrier film 23 makes between positive pole 21 and the negative pole 22 isolates, so that lithium ion passes through, prevents from simultaneously to contact the short circuit current that causes because of anodal 21 with negative pole 22.Barrier film 23 is made by for example synthetic resin such as polytetrafluoroethylene, polypropylene or poly perforated membrane or ceramic porous membrane, and barrier film 23 can have the wherein structure of two or more perforated membrane laminations.
Electrolyte solution with its dipping barrier film 23 comprises solvent and the electrolytic salt that is dissolved in the solvent.As solvent, for example enumerate propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, 1,2-dimethoxy-ethane, 1,2-diethoxyethane, gamma-butyrolacton, oxolane, 2-methyltetrahydrofuran, 1,3-dioxolanes, 4-methyl isophthalic acid, 3-dioxolanes, diethyl ether, sulfolane, methyl sulfolane, acetonitrile, propionitrile, methyl phenyl ethers anisole, acetic acid esters, butyrate, propionic ester etc.As solvent, can use selection one or both or multiple mixture wherein.
Solvent more preferably comprises the derivative of the cyclic carbonate of halogen atom.This is because can prevent the decomposition reaction of solvent in negative pole 22, and can improve cycle characteristics.The object lesson of cyclic carbonate derivative comprises the 4-fluoro-1 shown in the Chemical formula 1,3-dioxolanes-2-ketone, 1 shown in the Chemical formula 2,4-two fluoro-1,3-dioxolanes-2-ketone, 4 shown in the chemical formula 3,5-two fluoro-1,3-dioxolanes-2-ketone, the 4-two fluoro-5-fluoro-1 shown in the chemical formula 4,3-dioxolanes-2-ketone, 4-chloro-1 shown in the chemical formula 5,3-dioxolanes-2-ketone, 4 shown in the chemical formula 6,5-two chloro-1,3-dioxolanes-2-ketone, 4-bromo-1 shown in the chemical formula 7,3-dioxolanes-2-ketone, the 4-iodo-1 shown in the chemical formula 8,3-dioxolanes-2-ketone, 4-methyl fluoride-1 shown in the chemical formula 9,3-dioxolanes-2-ketone, the 4-Trifluoromethyl-1 shown in the Chemical formula 10,3-dioxolanes-2-ketone etc., and wherein preferred 4-fluoro-1,3-dioxolanes-2-ketone is because can obtain higher effect.
Chemical formula 1
Figure C200510107034D0013093253QIETU
Figure C200510107034D00131
[Chemical formula 2]
[chemical formula 3]
[chemical formula 4]
Figure C200510107034D00134
[chemical formula 5]
Figure C200510107034D00135
[chemical formula 6]
Figure C200510107034D00141
[chemical formula 7]
Figure C200510107034D00142
[chemical formula 8]
Figure C200510107034D00143
[chemical formula 9]
Figure C200510107034D00144
[Chemical formula 1 0]
Figure C200510107034D00145
Solvent can only comprise the derivative of carbonic ester; Yet, as solvent, preferably use carbonic acid ester derivative with at atmospheric pressure (1.01325 x 10 5Pa) down boiling point is the mixture of 150 ℃ or lower low boiling point solvent.This is because can improve ionic conductivity.The content of carbonic acid ester derivative in whole solvent is preferably 0.1 weight % to 80 weight % (comprising end points).When content is lower than this scope, prevent the effect deficiency of solvent decomposition reaction in negative pole 22, and when content was higher, viscosity raise and ionic conductivity descends.
As electrolytic salt, for example use lithium salts, and can use the mixture of a kind of lithium salts or two or more lithium salts.The example of lithium salts comprises LiClO 4, LiAsF 6, LiPF 6, LiBF 4, LiB (C 6H 5) 4, CH 3SO 3Li, CF 3SO 3Li, LiCl, LiBr etc.As electrolytic salt, preferably use lithium salts; Yet electrolytic salt is not limited to lithium salts especially.This is because when lithium ion during from supply such as anodal 21 grades, can obtain to help the enough lithium ions that charge and discharge.
This secondary cell for example forms as follows.
At first, for example, if with positive electrode active materials with necessary, electric conductor and binding agent are mixed with cathode mix, this cathode mix is dispersed in forms the cathode mix slurry in mixed solvent such as the N-N-methyl-2-2-pyrrolidone N-then.Then, this cathode mix is being applied to plus plate current-collecting body 21A, and with after this solvent seasoning, compressed formation anode active material layer 21B is so that form anodal 21.Then positive wire 25 is welded on anodal 21.
In addition, for example will be according to the negative active core-shell material of execution mode with if necessary, other negative active core-shell material and binding agent are mixed with the negative pole mixture, this negative pole mixture are scattered in to form the negative pole mixture paste in mixed solvent such as the N-N-methyl-2-2-pyrrolidone N-then.Then, be applied on the negative current collector 22A, and with after the solvent seasoning, compressed formation anode active material layer 22B is so that form negative pole 22 in the negative pole mixture paste.Then negative wire 26 is soldered to negative pole 22.
Afterwards, for example will comprise anodal 21 and negative pole 22 and have the laminate screw winding of barrier film 23 therebetween and the end portion of positive wire 25 is soldered to relief valve mechanism 15, and the end portion of negative wire 26 will be soldered on the battery case 11.The screw winding laminate that will comprise positive pole 21 and negative pole 22 then is clamped between a pair of insulation board 12 and 13, and the laminate with screw winding is contained in the battery case 11 then.Then electrolyte solution is injected battery case 11.Afterwards, battery cover 14, relief valve mechanism 15 and PTC device 16 are fixed in the open end part of battery case 11 by liner 17 calkings.Thus, finish secondary cell shown in Figure 1.
In this secondary cell, when charging, lithium ion is deviate from from positive pole 21, and inserts in the negative pole 22 through electrolyte.When discharging, lithium ion is deviate from and is inserted anodal 21 through electrolyte from negative pole 22.In the case, negative pole 22 comprises the negative active core-shell material of the tin, cobalt and the carbon that contain aforementioned proportion, therefore when keeping high power capacity, can improve cycle characteristics.
Therefore in the negative active core-shell material according to execution mode, the element as negative active core-shell material comprises tin, so can obtain high power capacity.In addition, the element as negative active core-shell material comprises cobalt, and cobalt is 30 weight % to 70 weight % (comprising end points) to the ratio of the total amount of tin and cobalt, so when keeping high power capacity, can improve cycle characteristics.In addition, the element as negative active core-shell material comprises carbon, and carbon content is 9.9 weight % to 29.7 weight % (comprising end points), so can further improve cycle characteristics.Therefore, in battery according to the present invention, use negative active core-shell material, can obtain high power capacity and excellent cycle characteristics like this.
And, when in negative active core-shell material, comprising silicon, can obtain higher capacity as element.
In addition, be included in the negative active core-shell material as element when being selected from least a of indium, niobium, germanium, titanium, molybdenum, aluminium, phosphorus, gallium and bismuth, and its content is 14.9 weight % or when lower, can further improve cycle characteristics, and more specifically, when its content is 2.4 weight % or when bigger, can obtain higher effect.
In addition, when the cyclic carbonate derivative that comprises halogen atom is included in the electrolyte, can prevent the decomposition reaction of solvent in negative pole 22, and can further improve cycle characteristics.
(second battery)
Fig. 3 has showed the structure of second secondary cell.In this secondary cell, the spiral winding electrode 30 that positive wire 31 is connected with negative wire 32 thereon is contained in the membranaceous packaging element 40, and can reduce size, weight and the profile of secondary cell.
Positive wire 31 and negative wire 32 are for example drawn to the outside at equidirectional from packaging element 40 inside.Positive wire 31 and negative wire 32 are for example made by metal material such as aluminium, copper, nickel or stainless steel, and have thin sheet form or shape of a mesh.
Packaging element 40 is for example by comprising that the ironed film of rectangular aluminum by this order lamination of nylon film, aluminium foil and polyethylene film makes.Configuration packaging element 40 is so that the polyethylene film of packaging element 40 is faced the electrode body 30 of screw winding, and the marginal portion of packaging element 40 adheres to mutually by melting welding or binding agent.The adhesive film 41 that air outside will being used to prevent enters inserts between packaging element 40, positive wire 31 and the negative wires 32.This adhesive film 41 is by the material that for example has cohesive force with positive wire 31 and negative wire 32, and for example vistanex such as polyethylene, polypropylene, modified poly ethylene or modified polypropene are made.
This packaging element 40 can replace above-mentioned aluminium lamination press mold to make by the laminated film with any other structure, high molecular weight film such as polyethylene or metallic film.
Fig. 4 has showed the sectional view of the spiral winding electrode 30 of getting along the I-I line selection of Fig. 3.This spiral winding electrode 30 is to comprise anodal 33 and negative pole 34 and have barrier film 35 and the screw winding laminate of dielectric substrate 36 between them, and the outermost layer of spiral winding electrode 30 is partly with boundary belt 37 protections.
Anodal 33 have anode active material layer 33B wherein is disposed at structure on the plus plate current-collecting body 33A one or both sides.Negative pole 34 has anode active material layer 34B wherein and is disposed at structure on the negative current collector 34A one or both sides, and configuration negative pole 34, so that anode active material layer 34B is in the face of anode active material layer 33B.Plus plate current-collecting body 33A, anode active material layer 33B, negative current collector 34A, anode active material layer 34B and barrier film 35 the structures structure with plus plate current-collecting body 21A, anode active material layer 21B, negative current collector 22A, anode active material layer 22B and barrier film 23 respectively are identical.
Dielectric substrate 36 comprises that electrolyte solution and conduct keep the high-molecular weight compounds of the maintenance body of (hold) electrolyte solution, and is so-called gel electrolyte.Preferred gel electrolyte because gel electrolyte can obtain high ionic conductivity, and can prevent the battery seepage.The structure of electrolyte solution (being solvent and electrolytic salt) is identical with cylindrical secondary battery shown in Fig. 1.The example of high-molecular weight compounds comprises fluorine-based high-molecular weight compounds such as polyvinylidene fluoride, or the copolymer of vinylidene fluoride and hexafluoropropylene, ether high-molecular weight compounds such as poly(ethylene oxide) or comprise the crosslinked etc. of poly(ethylene oxide), polyacrylonitrile.More specifically, according to OR stability, preferred fluorine-based high-molecular weight compounds.
For example, can form secondary cell as follows.
At first, will comprise that the precursor solution of solvent, electrolytic salt, high-molecular weight compounds and mixed solvent is applied on positive pole 33 and the negative pole 34, and the mixed solvent volatilization will be formed dielectric substrate 36.Then, with positive wire 31 by being welded to connect to the end portion of plus plate current-collecting body 33A, and with negative wire 32 by being welded to connect to the end portion of negative current collector 34A.Then; the negative pole 34 that is formed with the positive pole 33 of dielectric substrate 36 on it and is formed with dielectric substrate 36 on it has barrier film 35 laminated and forms laminate between them; this laminate is reeled at longitudinal spiral; and boundary belt 37 adhered to the outermost portion of laminate, to form spiral winding electrode 30.At last, for example spiral winding electrode 30 is clamped between the packaging element 40, and the marginal portion of packaging element 40 is adhering to each other by thermofussion welding etc., so that spiral winding electrode 30 is sealed in the packaging element 40.At this moment, adhesive film 41 is inserted between positive wire 31, negative wire 32 and the packaging element 40.So finish the secondary cell shown in Fig. 3 and 4.
In addition; this secondary cell can form as follows; at first; as mentioned above, form anodal 33 and negative pole 34, and positive wire 31 and negative wire 32 be connected to anodal 33 and negative pole 34 after; positive pole 33 and negative pole 34 had barrier film 35 laminated to form laminate between them; with this laminate screw winding, and boundary belt 37 adhered to the outermost portion of laminate, to form the precursor of screw winding body as spiral winding electrode 30.Then, this screw winding body is held between the packaging element 40, and will except that the marginal portion the side by thermofussion welding, shape pouch thus.Then, the screw winding body is contained in the packaging element 40.Then, if preparation comprises solvent, electrolytic salt, as the monomer of high-molecular weight compounds material and polymerization initiator with the other material of necessary words such as the electrolytical compound of conduct of polymerization inhibitor, and this compound is injected packaging element 40 inside.
After injecting, the opening of packaging element 40 is sealed through thermofussion welding under vacuum atmosphere as electrolytical compound.Then, monomer polymerization is formed high-molecular weight compounds, form gel electrolyte layer 36 thus, and assemble secondary cell shown in Figure 3 by applying heat.
The same with the situation of first secondary cell, this secondary cell can work, and can have the effect identical with first secondary cell.
(the 3rd battery)
Fig. 5 has showed the sectional view of the 3rd secondary cell.In this secondary cell, will comprise the positive pole 52 that connects positive wire 51 with the negative pole 54 that is connected negative wire 53 so that anodal 52 and negative pole 54 have the plate electrode body 50 that dielectric substrate faces with each other for 55 times betwixt and be included in the film like packaging element 56.The structure of this packaging element 56 is identical with above-mentioned packaging element 40.
Anodal 52 have anode active material layer 52B wherein is disposed at structure on the plus plate current-collecting body 52A.Negative pole 54 has negative active core-shell material 54B wherein and is disposed at structure on the negative current collector 54A, and configuration negative pole 54 so that anode active material layer 54B in the face of anode active material layer 52B.The structure of plus plate current-collecting body 52A, anode active material layer 52B, negative current collector 54A and the anode active material layer 54B structure with plus plate current-collecting body 21A, anode active material layer 21B, negative current collector 22A and anode active material layer 22B respectively is identical.
Dielectric substrate 55 is made by solid electrolyte.As solid electrolyte,, can use inorganic solid electrolyte or solid macromolecule amount electrolyte as long as this solid electrolyte is the material with lithium ion conductive.As inorganic solid electrolyte, enumerate the electrolyte that comprises lithium nitride, lithium iodide etc.Solid macromolecule amount electrolyte mainly by electrolytic salt and the high-molecular weight compounds that wherein dissolves electrolytic salt make.As the electrolytical high-molecular weight compounds of solid macromolecule amount, for example can use ether high-molecular weight compounds such as poly(ethylene oxide) or comprise the crosslinked of poly(ethylene oxide), ester group high-molecular weight compounds such as polymethacrylates or acrylate-based high-molecular weight compounds, or its mixture or copolymer.
Solid macromolecule amount electrolyte for example can make mixed solvent volatilize and form then by high-molecular weight compounds, electrolytic salt and mixed solvent are mixed.In addition, with electrolytic salt, as the monomer of the material of high-molecular weight compounds and polymerization initiator and if necessary other material such as the polymerization inhibitor of words dissolves in mixed solvent, and after making the mixed solvent volatilization, by apply heat with monomer polymerization to form high-molecular weight compounds, can form solid macromolecule amount electrolyte thus.
Inorganic electrolyte for example can be by vapour phase processes such as sputtering method, vacuum deposition method, laser ablation (ablation) method, ion plating and CVD (chemical vapour deposition (CVD)) method, or liquid deposition such as sol-gel process anodal 52 or negative pole 54 surfaces on form.
The same with the situation of first or second secondary cell, this secondary cell can work, and can have and first or second effect that secondary cell is identical.
(second execution mode)
Negative active core-shell material according to second embodiment of the invention has and the structure identical according to the negative active core-shell material of first execution mode, and different is to comprise that further iron is as element.
Iron content in the negative active core-shell material is preferably 0.3 weight % to 5.9 weight % (comprising end points).When this iron content is 0.3 weight % or when bigger, can further improve cycle characteristics; Yet when iron content surpassed 5.9 weight %, tin content reduced, and is difficult to obtain enough capacity thus.
The same with the situation of first execution mode, negative active core-shell material can be used in first battery, second battery and the 3rd battery.
[embodiment]
Specific embodiments of the invention will be discussed in more detail below.
(embodiment 1-1 to 1-7)
At first, preparation negative active core-shell material.As the material of negative active core-shell material, preparation cobalt powder, glass putty and carbon dust, and with cobalt powder and glass putty alloying formation cobalt-ashbury metal powder, then carbon dust is added in the alloyed powder, and, so form mixture with they dried mixing.At this moment, as shown in table 1 for the ratio of material, cobalt is fixed as 37 weight % to the ratio (hereinafter referred to as Co/ (Sn+Co) ratio) of tin and cobalt total amount, and the ratio of carbon is changed in the scope of 10 weight % to 30 weight % (comprising end points).Then, the steel ball of this mixture of 20g with about 400g diameter 9mm dropped in the reactor of Ito Seisakusho planetary ball mill.Then argon gas atmosphere is introduced in the reactor, and 10 minute operation and 10 minute at interval the circulation of repetition under 250rpm, reach 30 hours until total run time.Then, reactor is cooled to room temperature, and from reactor, takes out synthetic negative active core-shell material powder, this negative active core-shell material is moved through 280 purpose sieves to remove the coarse granule of negative active core-shell material powder.
[table 1]
Figure C200510107034D00201
Figure C200510107034D00202
Analyze the composition of the negative active core-shell material that obtains.Measure carbon content by carbon/sulfur analyzer, and pass through the content of ICP (inductively coupled plasma) emission spectroscopy measurements cobalt and tin.Assay value provides in table 1.Material proportion shown in the table 1 and assay value round off in first decimal place.Material proportion among the following embodiment provides by identical mode with assay value.In addition, when the negative active core-shell material to each acquisition carries out X-ray diffraction, observe the diffraction maximum that has wide half width in 2 θ=20 ° to 50 ° of scopes.Give the half width of the diffraction maximum of each negative active core-shell material in the table 1.In addition, when as shown in Figure 6 the negative active core-shell material of each acquisition being carried out XPS measuring, obtain peak P1.When analyzing peak P1, obtain the peak P2 of surface contamination carbon and the peak P3 of the Cls in the negative active core-shell material of the energy lower one side than peak P2.In each embodiment 1-1 to 1-7, in being lower than the zone of 284.5eV, obtain peak P3.In other words, confirm carbon in each negative active core-shell material and other element coupling.
Then, the negative active core-shell material powder among each embodiment 1-1 to 1-7 is used to form Coin shape secondary cell shown in Figure 7, and measures the initial charge capacity of this secondary cell.This Coin-shaped battery comprises the test electrode 61 of the negative active core-shell material that uses each embodiment, and it is included in the packaging element 62 and to electrode 63, it is connected with packaging element 64.This test electrode 61 and electrode 63 had barrier film 65 laminated with the electrolyte solution impregnation between them, then with it by liner 66 calkings, form Coin-shaped battery thus.
Test electrode 61 forms as follows.At first, the negative active core-shell material that 70 weight portions are obtained, 20 weight portion graphite (it is electric conductor and other negative active core-shell material), 1 weight portion mix as the polyvinylidene fluoride of binding agent as the acetylene black of electric conductor and 4 weight portions and form mixture.With this mixture be scattered in the suitable solvent form slurry after, this slurry is applied on the Copper Foil collector and dry.Be the sheet of diameter 15.2mm with this collector impression (stamp) then.
As to electrode 63, use to be embossed to the discoidal lithium metal plate of diameter as 15.5mm.As electrolyte solution, use the LiPF that wherein is dissolved with as electrolytic salt 6The mixed solvent that comprises ethylene carbonate, propylene carbonate and dimethyl carbonate.
For initial charge capacity, by being charged to cell voltage with constant current 1mA, this secondary cell reaches 0.2mV, charge to electric current with constant voltage 0.2mV then and reach 10 μ A, measure the charging capacity of per unit mass (it is the quality of removing the test electrode 61 beyond the quality of the quality of Copper Foil collector and binding agent).In the case, charging is meant that lithium enters the insertion reaction in the negative active core-shell material.The result provides in table 1 and Fig. 8.
In addition, form cylindrical secondary battery shown in Figure 1.At first, the positive electrode active materials that will make by nickel oxide, black and more black with quality: polyvinylidene fluoride=94:3:3 mixing formation mixture than nickel oxide: ketjen as the polyvinylidene fluoride of binding agent as the ketjen of electric conductor.This mixture is dispersed in solvent such as the N-N-methyl-2-2-pyrrolidone N-form the cathode mix slurry after, this cathode mix slurry evenly is applied on the plus plate current-collecting body 21A two sides of being made by the bar shaped aluminium foil, and dry.Then, form anode active material layer 21B, so that form anodal 21 by the roller press compression molding.Then, positive wire made of aluminum 25 is connected to plus plate current-collecting body 21A end.
In addition, will evenly be applied on the negative current collector 22A two sides of making by the slurry that comprises negative active core-shell material that forms as mentioned above by the bar shaped Copper Foil, and dry.Then, form anode active material layer 22B, so that form negative pole 22 by the roller press compression molding.Then, will be connected to negative current collector 22A end by the negative wire 26 that nickel is made.
After forming positive pole 21 and negative pole 22, preparation barrier film 23, and with negative pole 22, barrier film 23, positive pole 21 and barrier film 23 lamination formation in this order laminate, and with this laminate screw winding repeatedly, to form spiral winding electrode 20.
After forming spiral winding electrode 20, spiral winding electrode 20 is clamped between a pair of insulation board 12 and 13, negative wire 26 is soldered to battery case 11, and this positive wire 25 is soldered to relief valve mechanism 15.Then, spiral winding electrode 20 is included in the battery case of being made by the iron of nickel plating 11.Then, above-mentioned electrolyte solution is injected battery case 11 by decomposition method.
After electrolyte solution injects battery case, battery cover 14 there are 17 pairs of battery case 11 calkings of liner of pitch by its surface coated, obtain cylindrical secondary battery shown in Figure 1 thus.
Measure the cycle characteristics of gained secondary cell.The result provides in table 1 and Fig. 8.At this moment, measure cycle characteristics as follows.
At first, this secondary cell being charged to constant current 0.5A after cell voltage reaches 4.2V, this secondary cell is charged to electric current with constant voltage 4.2V reach 10mA.Then this secondary cell is discharged to cell voltage with constant current 0.25A and reaches 2.6V.The circulation first time that so discharges and recharges.
For the second time or circulation subsequently, secondary cell is being charged to constant current 1.4A after cell voltage reaches 4.2V, this secondary cell is charged to electric current with constant voltage 4.2V reach 10mA, then this secondary cell is discharged to cell voltage with constant current 1.0A and reaches 2.6V.For cycle characteristics, measure the 300th circulation capability retention (discharge capacity in the 300th circulation)/(discharge capacity in the circulation for the second time) x100 (%) to the discharge capacity in the circulation for the second time.
As the comparative example 1-1 with respect to embodiment 1-1 to 1-7, the same with the situation of embodiment 1-1 to 1-7, synthetic negative active core-shell material also forms secondary cell, and different is not use carbon dust as material.In addition, 1-2 to 1-7 is the same with the situation of embodiment 1-1 to 1-7 as a comparative example, synthetic negative active core-shell material, and form secondary cell, different is that the carbon powder material ratio is pressed variation shown in the table 1.The negative active core-shell material of comparative example 1-1 to 1-7 is carried out composition analysis and measures to 50 ° of observed half widths with diffraction maximum of wide half width of scope in 2 θ=20 °.The result provides in table 1.In addition, when the negative active core-shell material to comparative example 1-1 to 1-7 carries out XPS measuring, in the negative active core-shell material of comparative example 1-3 to 1-7, obtain the peak P1 shown in Fig. 6.When analyzing peak P1, the same with embodiment 1-1 to 1-7, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and obtain the peak P3 among each comparative example 1-3 to 1-7 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.On the other hand, in comparative example 1-1, as shown in Figure 9, obtain peak P4, and when analyzing peak P4, only obtain the peak P2 of surface contamination carbon.At comparative example 1-2, very little as the carbon amount of material, thus only obtain peak P2 by analyzing, and almost detect less than peak P3.
In addition, measure the charging capacity and the cycle characteristics of the secondary cell of comparative example 1-1 to 1-7 in an identical manner.The result provides in table 1 and Fig. 8.
From table 1 and Fig. 8, it is evident that, carbon content in the negative active core-shell material is among the embodiment 1-1 to 1-7 of 9.9 weight to 29.7 weight % (comprising end points) therein, compare at this extraneous comparative example 1-1 to 1-7 with carbon content wherein, can obviously improve capability retention.Simultaneously, can improve initial charge capacity and discharge capacity.
In addition, the carbon content in negative active core-shell material is 14.9 weight % to 29.7 weight % (comprising end points), and more specifically 16.8 weight % to 24.8 weight % can obtain higher value when (comprising end points).
In other words, find when carbon content be that 9.9 weight % to 29.7 weight % are when (comprising end points), can improve capacity and cycle characteristics, and carbon content more preferably 14.9 weight % to 29.7 weight % (comprising end points), more preferably 16.8 weight % to 24.8 weight % (comprising end points)
(embodiment 2-1 to 2-9)
With equally forming secondary cell among the embodiment 1-1 to 1-7, different is that synthetic wherein cobalt, tin and material with carbon element are than the negative active core-shell material of variation as shown in table 2.More specifically, the material with carbon element ratio is fixed as 10 weight %, Co/ (Sn+Co) ratio changes in the scope of 30 weight % to 70 weight % (comprising end points).
[table 2]
Figure C200510107034D00231
Figure C200510107034D00241
As comparative example 2-1 to 2-4 with respect to embodiment 2-1 to 2-9, the same with embodiment 2-1 to 2-9, form negative active core-shell material and secondary cell, different is the variation as shown in table 2 of Co/ (Sn+Co) ratio.Co/ among comparative example 2-1,2-2,2-3 and the 2-4 (Sn+Co) ratio is respectively 28 weight %, 25 weight %, 20 weight % and 75 weight %.
The same with embodiment 1-1 to 1-7, the negative active core-shell material of embodiment 2-1 to 1-9 and comparative example 2-1 to 1-4 is carried out composition analysis and measures to 50 ° of observed half widths with diffraction maximum of wide half width of scope in 2 θ=20 °.The result provides in table 2.In addition, the same with embodiment 1-1 to 1-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, the same with embodiment 1-1 to 1-7, the initial charge capacity and the cycle characteristics of measurement secondary cell.The result provides in table 2 and Figure 10.
From table 2 and Figure 10, it is evident that, Co/ (Sn+Co) ratio is among the embodiment 2-1 to 2-9 of 30 weight % to 70 weight % (comprising end points) therein, the comparative example 2-1 to 2-3 that is lower than 30 weight % with Co/ (Sn+Co) ratio wherein compares, can obviously improve capability retention, and the comparative example 2-4 that is higher than 70 weight % with Co/ (Sn+Co) ratio wherein compares, and can obviously improve initial charge capacity.More specifically, when Co/ (Sn+Co) ratio is equal to or less than 60 weight %, can obtain high initial charge capacity.
In other words, find when Co/ (Sn+Co) ratio be 30 weight % to 70 weight % when (comprising end points), can improve capacity and cycle characteristics.Find Co/ (Sn+Co) ratio 60 weight % or lower more preferably in addition.
(embodiment 3-1 to 3-9)
Equally form secondary cell with embodiment 1-1 to 1-7, different is that synthetic wherein cobalt, tin and material with carbon element are than the negative active core-shell material of variation as shown in table 3.More specifically, the material with carbon element ratio is fixed as 20 weight %, Co/ (Sn+Co) ratio changes in the scope of 30 weight % to 70 weight % (comprising end points).
[table 3]
Figure C200510107034D00251
As comparative example 3-1 to 3-4 with respect to embodiment 3-1 to 3-9, the same with embodiment 3-1 to 3-9, form negative active core-shell material and secondary cell, Co/ (Sn+Co) ratio that different is is according to changing shown in the table 3, and the Co/ among comparative example 3-1,3-2,3-3 and the 3-4 (Sn+Co) ratio is respectively 28 weight %, 25 weight %, 20 weight % and 75 weight %.
The same with embodiment 1-1 to 1-7, the negative active core-shell material of embodiment 3-1 to 3-9 and comparative example 3-1 to 3-4 is carried out composition analysis and the measurement of the half width of observed diffraction maximum with wide half width to 50 ° of scopes in 2 θ=20 °.The result provides in table 3.In addition, the same with embodiment 1-1 to 1-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, the same with embodiment 1-1 to 1-7, the initial charge capacity and the cycle characteristics of measurement secondary cell.The result provides in table 3 and Figure 11.
From table 3 and Figure 11, it is evident that, obtain with embodiment 2-1 to 2-9 in those identical results.Promptly find when Co/ (Sn+Co) ratio is 30 weight % to 70 weight %,, also can improve capacity and cycle characteristics even carbon content is under the situation of 19.8 weight % therein.
(embodiment 4-1 to 4-9)
Equally form secondary cell with embodiment 1-1 to 1-7, different is that synthetic wherein cobalt, tin and material with carbon element are than the negative active core-shell material of variation as shown in table 4.More specifically, the material with carbon element ratio is fixed as 30 weight %, Co/ (Sn+Co) ratio changes in the scope of 30 weight % to 70 weight % (comprising end points).
[table 4]
Figure C200510107034D00271
As comparative example 4-1 to 4-4 with respect to embodiment 4-1 to 4-9, the same with embodiment 4-1 to 4-9, form negative active core-shell material and secondary cell, Co/ (Sn+Co) ratio that different is is according to changing shown in the table 4, and the Co/ among comparative example 4-1,4-2,4-3 and the 4-4 (Sn+Co) ratio is respectively 28 weight %, 25 weight %, 20 weight % and 75 weight %.
The same with embodiment 1-1 to 1-7, the negative active core-shell material of embodiment 4-1 to 4-9 and comparative example 4-1 to 4-4 is carried out composition analysis and the measurement of the half width of observed diffraction maximum with wide half width to 50 ° of scopes in 2 θ=20 °.The result provides in table 4.In addition, the same with embodiment 1-1 to 1-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, measure the initial charge capacity and the cycle characteristics of secondary cell by identical mode.The result provides in table 4 and Figure 12
From table 4 and Figure 12, it is evident that, obtain with embodiment 2-1 to 2-9 in those identical results.Promptly find when Co/ (Sn+Co) ratio be 30 weight % to 70 weight % when (comprising end points), even carbon content is under the situation of 29.7 weight % therein, also can improve capacity and cycle characteristics.
(embodiment 5-1 to 5-6 and 6-1 to 6-6)
Equally form negative active core-shell material and secondary cell with embodiment 1-1 to 1-7, different is changes operating time and revolution when synthetic negative active core-shell material, to change in 2 θ=20 ° observed half width with diffraction maximum of wide half width to 50 ° of scopes.At this moment, in the material ratio of cobalt, tin and carbon, according to the material with carbon element ratio that changes shown in the table 5 among embodiment 5-1 to 5-6 and the embodiment 6-1 to 6-6, Co/ (Sn+Co) ratio is identical.
[table 5]
Figure C200510107034D00272
Figure C200510107034D00281
Figure C200510107034D00282
The same with embodiment 1-1 to 1-7, the negative active core-shell material of embodiment 5-1 to 5-6 and 6-1 to 6-6 is carried out composition analysis and the measurement of the half width of observed diffraction maximum with wide half width to 50 ° of scopes in 2 θ=20 °.The result provides in table 5.In addition, the same with embodiment 1-1 to 1-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, the same with embodiment 1-1 to 1-7, the initial charge capacity and the cycle characteristics of measurement secondary cell.The result provides in table 5.
It is evident that from table 5 in embodiment 5-1 to 5-6 and 6-1 to 6-6, half width is big more, capability retention improves big more.In other words, find when the half width of diffraction maximum has bigger reacting phase, can improve cycle characteristics.
(embodiment 7-1 to 7-11)
Equally form negative active core-shell material and secondary cell with embodiment 1-1 to 1-7, different is that silica flour further is used as material, and the material of cobalt, tin, carbon and silicon is than variation as shown in table 6.More specifically, the material of silica flour ratio changes in the scope of 0.3 weight % to 10 weight % (comprising end points), and Co/ (Sn+Co) ratio and material with carbon element ratio is fixing.The same with embodiment 1-1 to 1-7, the negative active core-shell material of embodiment 7-1 to 7-11 is carried out composition analysis.The result provides in table 6.Silicone content is by the ICP emission spectrometry.In addition, the same with embodiment 1-1 to 1-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, by identical mode, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 6.
[table 6]
Figure C200510107034D00291
Figure C200510107034D00292
From table 6, it is evident that, comprise therein among the embodiment 7-1 to 7-11 of silicon, compare, can further improve initial charge capacity with the embodiment 1-5 that does not wherein comprise silicon.Yet, the trend that exists capability retention to raise and reduce with silicone content.
In other words, find when silicon is included in the negative active core-shell material, can improve capacity, and silicone content to be preferably 0.5 weight % to 7.9 weight % (comprising end points).
(embodiment 8-1 to 8-10)
In embodiment 8-1, the same with embodiment 1-1 to 1-7, synthetic negative active core-shell material also forms secondary cell, and the material of different is cobalt, tin and carbon is than by changing shown in the table 7.In embodiment 8-2 to 8-10, the same with embodiment 1-1 to 1-7, synthetic negative active core-shell material also forms secondary cell, and different is preparation cobalt powder, glass putty, carbon dust and titanium valve be as material, and with its material proportion by changing shown in the table 7.More specifically, the material of titanium is than variation in 0 weight % to 16 weight % (comprising end points) scope, and the material ratio of fixation of C o/ (Sn+Co) ratio and carbon.In addition, negative active core-shell material by with cobalt powder, glass putty and titanium valve alloying to form cobalt-Xi-titanium alloy powder, then carbon dust is sneaked in this alloy powder and synthesizes.The same with embodiment 1-1 to 1-7, the negative active core-shell material of embodiment 8-1 to 8-10 is carried out composition analysis.The result provides in table 7.Ti content is by the ICP emission spectrometry.In addition, the same with embodiment 1-1 to 1-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, measure the initial charge capacity and the cycle characteristics of secondary cell by identical mode.The result provides in table 7 and Figure 13.
[table 7]
Figure C200510107034D00301
Figure C200510107034D00311
Figure C200510107034D00312
From table 7 and Figure 13, it is evident that, comprise 14.9 weight % therein or still less among the embodiment 8-2 to 8-9 of titanium, with the embodiment 8-1 that does not wherein comprise titanium with compare comprising the embodiment 8-10 that surpasses 14.9 weight % titaniums, can improve capability retention.In addition, when Ti content is equal to or higher than 2.4 weight %, in the time of more specifically in 4.0 weight % to 12.9 weight % (comprising end points) scopes, can obtain higher value.
In other words, find when comprising 14.9 weight % or titanium still less in the negative active core-shell material, can further to improve cycle characteristics, and to comprise more preferably 2.4 weight % or more, more preferably at the titanium of 4.0 weight % to 12.9 weight %.
(embodiment 9-1 to 9-9)
Equally synthesize negative active core-shell material and form secondary cell with embodiment 1-1 to 1-7, different is to prepare cobalt powder, glass putty, carbon dust and bismuth meal as material, and its material changes than pressing shown in the table 8.More specifically, the material of bismuth ratio changes in 1.2 weight % to 16 weight % (comprising end points) scopes, and Co/ (Sn+Co) ratio and material with carbon element ratio is fixing.Negative active core-shell material by with cobalt powder, glass putty and bismuth meal alloying to form cobalt-tin-bismuth alloy electroplating powder, then carbon dust is sneaked in this alloy powder and synthesizes.The same with embodiment 1-1 to 1-7, the anticathode active material carries out composition analysis.The result provides in table 8.Bi content is by the ICP emission spectrometry.In addition, the same with embodiment 1-1 to 1-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the district that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, by identical mode, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 8 and Figure 14.
[table 8]
Figure C200510107034D00313
Figure C200510107034D00321
Figure C200510107034D00322
As table 8 and shown in Figure 14, add therein among the embodiment 9-1 to 9-9 of bismuth, obtain and the identical result of embodiment 8-2 to 8-10 who wherein adds titanium.In other words, find when comprising 14.9 weight % or bismuth still less in the negative active core-shell material, can further improve cycle characteristics, and more preferably comprise 4.0 weight % or more bismuth.
(embodiment 10-1 to 10-14)
Equally synthesize negative active core-shell material and form secondary cell with embodiment 1-1 to 1-7, different is preparation cobalt powder, glass putty, carbon dust and molybdenum powder, niobium powder, aluminium powder, germanium powder, indium powder, gallium powder, phosphorus powder or aluminium powder and phosphorus powder be as material, and with the material of cobalt, tin, carbon and molybdenum, niobium, aluminium, germanium, indium, gallium, phosphorus or aluminium and phosphorus than pressing variation shown in the table 9.More specifically, the material of molybdenum, niobium, aluminium, germanium, indium, gallium, phosphorus or aluminium and phosphorus ratio is 3 weight %, 4 weight %, 5 weight % or 6 weight %, and is 35 weight % with Co/ (Sn+Co) fixed ratio.In addition, negative active core-shell material is by forming cobalt-ashbury metal powder with cobalt powder and glass putty alloying, then carbon dust and molybdenum powder, niobium powder, aluminium powder, germanium powder, indium powder, gallium powder, phosphorus powder or aluminium powder and phosphorus powder sneaked in the alloy powder and synthesizes.The same with embodiment 1-1 to 1-7, the negative active core-shell material of embodiment 10-1 to 10-14 is carried out composition analysis.The result provides in table 9.The content of molybdenum, niobium, aluminium, germanium, indium, gallium and phosphorus is by the ICP emission spectroscopy measurements.In addition, the same with embodiment 1-1 to 1-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, by identical mode, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 10.
[table 9]
Figure C200510107034D00331
Figure C200510107034D00332
[table 10]
Initial charge capacity (mAh/g) Discharge capacity (mAh/cm in circulating for the second time 3) Discharge capacity (mAh/cm in the 300th circulation 3) Capability retention (%)
Embodiment 8-1 530 140 98 70
Embodiment 10-1 510 136 107 79
Embodiment 10-2 508 138 110 80
Embodiment 10-3 535 140 116 83
Embodiment 10-4 530 139 114 82
Embodiment 10-5 532 138 113 82
Embodiment 10-6 556 141 110 78
Embodiment 10-7 552 144 117 81
Embodiment 10-8 540 142 114 80
Embodiment 10-9 540 139 110 79
Embodiment 10-10 544 140 112 80
Embodiment 10-11 550 144 120 83
Embodiment 10-12 525 138 112 81
Embodiment 10-13 541 141 110 78
Embodiment 10-14 560 147 113 77
Shown in table 9 and 10, the same with embodiment 8-2 to 8-10 in embodiment 10-1 to 10-14 with 9-1 to 9-9, can improve cycle characteristics.In other words, find to comprise when being selected from least a in molybdenum, niobium, aluminium, germanium, indium, gallium and the phosphorus, further the modification cycle characteristics when negative active core-shell material.
(embodiment 11-1 to 11-8)
Equally synthesize negative active core-shell material and form secondary cell with embodiment 1-1 to 1-7, different is that preparation cobalt powder, glass putty, carbon dust, silica flour, titanium valve and indium powder are as material and with the variation as shown in table 11 of its material proportion.More specifically, with the material of titanium or titanium and indium than the scope of 0 weight % to 10 weight % (comprising end points) in, changing, and with the material of Co/ (Sn+Co) ratio, carbon than and the material of silicon than fixing.In addition, negative active core-shell material passes through cobalt powder and glass putty, cobalt powder, glass putty and titanium valve, or cobalt powder, glass putty, titanium valve and indium powder alloying form cobalt-ashbury metal powder or cobalt-Xi-titanium alloy powder or cobalt-Xi-titanium-indium alloy powder are sneaked into carbon dust and silica flour then in the alloy powder and are synthesized.The same with embodiment 1-1 to 1-7, the negative active core-shell material of embodiment 11-1 to 11-8 is carried out composition analysis.The result provides in table 11.Silicon, titanium and indium content are by the ICP emission spectroscopy measurements.In addition, the same with embodiment 1-1 to 1-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, by identical mode, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 12.
[table 11]
Figure C200510107034D00351
Figure C200510107034D00352
[table 12]
Initial charge capacity (mAh/g) Discharge capacity (mAh/cm in circulating for the second time 3) Discharge capacity (mAh/cm in the 300th circulation 3) Capability retention (%)
Embodiment 8-1 530 140 98 70
Embodiment 11-1 568 147 96 65
Embodiment 11-2 592 148 110 74
Embodiment 11-3 600 149 113 76
Embodiment 11-4 602 150 113 75
Embodiment 11-5 588 147 112 76
Embodiment 11-6 597 149 112 75
Embodiment 11-7 598 149 113 76
Embodiment 11-8 593 148 110 74
It is evident that from table 12 silica removal also adds among the embodiment 11-2 to 11-8 of titanium or titanium and indium therein outward, compare with 11-1, can further improve initial charge capacity and capability retention with the embodiment 8-1 that does not wherein comprise them.
In other words, find when at least a and silicon that will be selected from titanium, molybdenum, niobium, aluminium, germanium, indium, gallium and phosphorus is included in the negative active core-shell material, can further improve capacity and cycle characteristics.
(embodiment 12-1 to 12-6)
With the equally synthetic negative active core-shell material of embodiment 1-1 to 1-7, different is preparation cobalt powder, glass putty, carbon dust, silica flour and titanium valve as material and will cobalt powder and glass putty or cobalt powder, glass putty and titanium valve alloying form cobalt-ashbury metal powder or or cobalt-Xi-titanium alloy powder after, carbon dust or carbon dust and silica flour are mixed into alloy powder.At this moment, material proportion variation as shown in table 13.In addition, equally form cylindrical secondary battery with embodiment 1-1 to 1-7, different is to use negative active core-shell material in embodiment 12-1 to 12-3 and embodiment 12-4 to 12-6, and changes the composition of electrolyte solution.At this moment, in embodiment 12-1 to 12-3, using wherein will be as the LiPF of electrolytic salt 6Being dissolved in the mass ratio that comprises ethylene carbonate, propylene carbonate and dimethyl carbonate with ratio 1mol/l is ethylene carbonate: the electrolyte solution in the mixed solvent of propylene carbonate: dimethyl carbonate=30:10:60, and in embodiment 12-4 to 12-6, using wherein will be as the LiPF of electrolytic salt 6Be dissolved in ratio 1mol/l and comprise 4-fluoro-1,3-dioxolanes-2-ketone, ethylene carbonate, propylene carbonate and dimethyl carbonate be 4-fluoro-1 with the mass ratio, 3-dioxolanes-2-ketone: the electrolyte solution in the mixed solvent of ethylene carbonate: propylene carbonate: dimethyl carbonate=20:10:10:60.In embodiment 12-1 and 12-4, embodiment 12-2 and 12-5 and embodiment 12-3 and 12-6, use identical negative active core-shell material.
The same with embodiment 1-1 to 1-7, the negative active core-shell material of embodiment 12-1 to 12-6 is carried out composition analysis.The result provides in table 13.In addition, the same with embodiment 1-1 to 1-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, by identical mode, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 13.
[table 13]
Figure C200510107034D00371
EC: ethylene carbonate
PC: propylene carbonate
Figure C200510107034D00372
DMC: dimethyl carbonate
FEC:4-fluoro-1,3-dioxolanes-2-ketone
From table 13, it is evident that, therein with 4-fluoro-1,3-dioxolanes-2-ketone is as among the embodiment 12-4 to 12-6 of solvent, and wherein do not use 4-fluoro-1, the embodiment 12-1 to 12-3 of 3-dioxolanes-2-ketone compares, and can further improve capability retention.
(embodiment 13-1 to 13-18)
With the same cylindrical secondary battery that forms with 12-4 of embodiment 12-1, different is solvent composition variation as shown in table 14.Equally measure the cycle characteristics of secondary cell with embodiment 1-1 to 1-7.The result provides in table 14.
[table 14]
Figure C200510107034D00381
EC: ethylene carbonate
Figure C200510107034D00382
PC: propylene carbonate
DMC: dimethyl carbonate
FEC:4-fluoro-1,3-dioxolanes-2-ketone
It is evident that from table 14 along with 4-fluoro-1, the amount of 3-dioxolanes-2-ketone increases, capability retention rises to maximum, reduces then.
In other words, find when comprising 4-fluoro-13-dioxolanes-2-ketone, no matter the composition of solvent, all can improve cycle characteristics, and particularly, when 4-fluoro-1, the content of 3-dioxolanes-2-ketone is 0.1 weight % to 80 weight % when (comprising end points), can obtain higher effect
(embodiment 14-1 to 14-6).
The same with 14-2, form cylindrical secondary battery, different being to use comprises that another derivative of the cyclic carbonate of halogen atom replaces 4-fluoro-1,3-dioxolanes-2-ketone.At this moment, with 4-two fluoro-1,3-dioxolanes-2-ketone, 4-two fluoro-5-fluoro-1,3-dioxolanes-2-ketone, 4-chloro-1,3-dioxolanes-2-ketone, 4-bromo-1,3-dioxolanes-2-ketone, 4-iodo-1,3-dioxolanes-2-ketone and 4-methyl fluoride-1,3-dioxolanes-2-ketone is respectively applied among embodiment 14-1, embodiment 14-2, embodiment 14-3, embodiment 14-4, embodiment 14-5 and the embodiment 14-6.
The same with embodiment 1-1 to 1-7, the cycle characteristics of the secondary cell of measurement embodiment 14-1 to 14-6.The result provides in table 15.
[table 15]
EC: ethylene carbonate C1-EC:4-chloro-1,3-dioxolanes-2-ketone
PC: propylene carbonate Br-EC:4-bromo-1,3-dioxolanes-2-ketone
DMC: dimethyl carbonate I-EC:4-iodo-1,3-dioxolanes-2-ketone
FEC:4-fluoro-1,3-dioxolanes-2-ketone
F-PC:4-methyl fluoride-1,3-dioxolanes-2-ketone
DFEC:4-two fluoro-1,3-dioxolanes-2-ketone
Tri-FEC:4-two fluoro-5-fluoro-1,3-dioxolanes-2-ketone
From table 15, it is evident that, even use another derivative of the cyclic carbonate that comprises halogen atom, also with the same cycle characteristics that improves of embodiment 12-4.Yet, using 4-fluoro-1 therein, capability retention is high especially among the embodiment 12-4 of 3-dioxolanes-2-ketone.In other words, find when comprise the cyclic carbonate derivative of halogen atom, can to improve cycle characteristics, and when comprising 4-fluoro-1, during 3-dioxolanes-2-ketone derivatives, effective especially aspect the improvement cycle characteristics.
(embodiment 15-1 to 15-7)
Equally form the Coin shape secondary cell with embodiment 1-1 to 1-7, different is to form the dielectric substrate that is made of gel electrolyte at test electrode 61 with on to the surface of electrode 63, replaces liquid electrolyte solution.In other words, will be by cobalt, tin and carbon by being used for test electrode 61 than mixing the negative active core-shell material that synthesizes with the same material shown in the table 16 with among the embodiment 1-1 to 1-7.In addition, dielectric substrate forms as follows.At first, will be mixed in the electrolyte solution that (this electrolyte solution is by will be as the ethylene carbonate of solvent and propylene carbonate with as the LiPF of electrolytic salt as the copolymer of the vinylidene fluoride of high-molecular weight compounds and hexafluoropropylene with as the diethyl carbonate of mixed solvent 6By quality than ethylene carbonate: propylene carbonate: LiPF 6=11.5:11.5:4 mixes and forms) to have electrolyte solution: high-molecular weight compounds: mixed solvent mass ratio=27:10:60 forms precursor solution thus.The molecular weight of the copolymer of vinylidene fluoride and hexafluoropropylene is 600000.The precursor solution that obtains evenly is applied on test electrode 61 and the opposed face to electrode 63, and it was at room temperature placed 6 hours so that the diethyl carbonate volatilization forms gel electrolyte layer thus.
The same with embodiment 1-1 to 1-7, the initial charge capacity of measurement Coin shape secondary cell.The result provides in table 16 and Figure 15.
[table 16]
Figure C200510107034D00411
Figure C200510107034D00412
In addition, form the secondary cell shown in Fig. 3 and 4.At first, equally form positive pole 33 and negative pole 34, and positive wire 31 is connected with negative wire 32 with embodiment 1-1 to 1-7.
Then, above-mentioned precursor solution evenly is applied on positive pole 33 and the negative pole 32, and it was at room temperature placed 6 hours so that the diethyl carbonate volatilization forms gel electrolyte layer 36 thus.
Then, positive pole 33 and negative pole 34 there are barrier film 35 laminated betwixt,, form laminate thus, and the laminate screw winding is formed spiral winding electrode 30 so that form the positive pole 33 of dielectric substrate 36 on it and the surface of negative pole 34 is faced mutually.
With obtaining spiral winding electrode 30 vacuum seals in the packaging element 40 that constitutes by the ironed film of damp proof aluminium lamination, form the secondary cell shown in Fig. 3 and 4 thus.
The same with embodiment 1-1 to 1-7, the cycle characteristics of measurement secondary cell.The result provides in table 16 and Figure 15.
As comparative example 15-1 to 15-7 with respect to embodiment 15-1 to 15-7, equally form secondary cell with embodiment 15-1 to 15-7, different is to use by mixing the synthetic negative active core-shell material of cobalt, tin and carbon with the ratio of the material shown in the table 16, promptly with the equally synthetic negative active core-shell material of comparative example 1-1 to 1-7.
Measure secondary cell initial charge capacity and cycle characteristics that comparative example 15-1 to 15-7 obtains.The result provides in table 16 and Figure 15.
From table 16 and Figure 15, it is evident that, obtain with embodiment 1-1 to 1-7 in those identical results.In other words, even find to use gel electrolyte, in carbon content is under the situation of 9.9 weight % to 29.7 weight % (comprising end points), can improve capacity and cycle characteristics, and carbon content is 14.9 weight % to 29.7 weight % (comprising end points) more preferably, more preferably 16.8 weight % to 24.8 weight % (comprising end points).
(embodiment 16-1 to 16-9,17-1 to 17-9 and 18-1 to 18-9)
For embodiment 16-1 to 16-9, equally form secondary cell with embodiment 15-1 to 15-9, different is shown in table 17, use the material ratio of carbon wherein to be fixed as the negative active core-shell material that 10 weight % and Co/ (Sn+Co) ratio change in the scope of 30 weight % to 70 weight % (comprising end points), promptly with the equally synthetic negative active core-shell material of embodiment 2-1 to 2-9.In addition, as comparative example 16-1 to 16-4 with respect to embodiment 16-1 to 16-9, equally form secondary cell with embodiment 16-1 to 16-9, different is shown in table 17, using wherein, the material ratio of carbon is fixed as 10 weight %, and Co/ (Sn+Co) ratio is the negative active core-shell material of 28 weight %, 25 weight %, 20 weight % and 75 weight %, promptly with the equally synthetic negative active core-shell material of comparative example 2-1 to 2-4.
[table 17]
Figure C200510107034D00431
For embodiment 17-1 to 17-9, equally form secondary cell with embodiment 15-1 to 15-9, different is shown in table 18, use the material ratio of carbon wherein to be fixed as the negative active core-shell material that 20 weight % and Co/ (Sn+Co) ratio change in the scope of 30 weight % to 70 weight % (comprising end points), promptly with the equally synthetic negative active core-shell material of embodiment 3-1 to 3-9.In addition, as comparative example 17-1 to 17-4 with respect to embodiment 17-1 to 17-9, equally form secondary cell with embodiment 17-1 to 17-9, different is shown in table 18, using wherein, the material ratio of carbon is fixed as 20 weight %, and Co/ (Sn+Co) ratio is the negative active core-shell material of 28 weight %, 25 weight %, 20 weight % and 75 weight %, promptly with the equally synthetic negative active core-shell material of comparative example 3-1 to 3-4.
[table 18]
Figure C200510107034D00441
For embodiment 18-1 to 18-9, equally form secondary cell with embodiment 15-1 to 15-9, different is shown in table 19, use the material ratio of carbon wherein to be fixed as the negative active core-shell material that 30 weight % and Co/ (Sn+Co) ratio change in 30 weight % to 70 weight % (comprising end points) scopes, promptly with the equally synthetic negative active core-shell material of embodiment 4-1 to 4-9.In addition, as comparative example 18-1 to 18-4 with respect to embodiment 18-1 to 18-9, equally form secondary cell with embodiment 18-1 to 18-9, different is shown in table 19, using wherein, the material ratio of carbon is fixed as 30 weight %, and Co/ (Sn+Co) ratio is the negative active core-shell material of 28 weight %, 25 weight %, 20 weight % and 75 weight %, promptly with the equally synthetic negative active core-shell material of comparative example 4-1 to 4-4.
[table 19]
Figure C200510107034D00451
The same with embodiment 1-1 to 1-7, measure embodiment 16-1 to 16-9,17-1 to 17-9 and 18-1 to 18-9 and comparative example 16-1 to 16-4, the initial capacity of 17-1 to 17-4 and 18-1 to 18-4 and cycle characteristics.The result table 17 to 19 and Figure 16 to 18 in provide.
From table 17 to 19 and Figure 16 to 18 it is evident that, obtain and embodiment 2-1 to 2-9 the result that 3-1 to 3-9 is identical with 4-1 to 4-9.In other words, find in Co/ (Sn+Co) ratio to be under the situation of 30 weight % to 70 weight % (comprising end points),, also can improve capacity and cycle characteristics even use gel electrolyte.In addition, find Co/ (Sn+Co) ratio 60 weight % or lower more preferably.
(embodiment 19-1 to 19-11)
Equally form secondary cell with embodiment 15-1 to 15-9, different is shown in table 20, using wherein, silica flour material ratio changes in the scope of 0.3 weight % to 10 weight % (comprising end points) and Co/ (Sn+Co) ratio and the fixing negative active core-shell material of material with carbon element ratio, the i.e. negative active core-shell material that equally synthesizes with embodiment 7-1 to 7-11.
The same with embodiment 1-1 to 1-9, the initial charge capacity and the cycle characteristics of the secondary cell of measurement embodiment 19-1 to 19-11.The result provides in table 21.
[table 20]
Figure C200510107034D00471
Figure C200510107034D00472
[table 21]
Initial charge capacity (mAh/g) Discharge capacity (mAh/cm in circulating for the second time 3) Discharge capacity (mAh/cm in the 300th circulation 3) Capability retention (%)
Embodiment 15-5 500 112 80 71
Embodiment 19-1 501 112 80 71
Embodiment 19-2 504 113 78 69
Embodiment 19-3 523 116 79 68
Embodiment 19-4 532 118 78 66
Embodiment 19-5 546 119 75 63
Embodiment 19-6 561 122 75 62
Embodiment 19-7 580 126 75 60
Embodiment 19-8 591 127 69 54
Embodiment 19-9 608 127 48 38
Embodiment 19-10 630 129 27 21
Embodiment 19-11 658 131 14 11
Figure C200510107034D00481
From table 21, it is evident that, obtain the result identical with embodiment 7-1 to 7-11.In other words, even find to use gel electrolyte, when negative active core-shell material comprises silicon, also can improve capacity, and silicone content is preferably 0.5 weight % to 7.9 weight % (comprising end points).
(embodiment 20-1 to 20-10)
Equally form secondary cell with embodiment 15-1 to 15-9, different is shown in table 22, using wherein, titanium material ratio changes in the scope of 0 weight % to 16 weight % (comprising end points) and Co/ (Sn+Co) ratio and the fixing negative active core-shell material of material with carbon element ratio, the i.e. negative active core-shell material that equally synthesizes with embodiment 8-1 to 8-10.
[table 22]
Figure C200510107034D00491
Figure C200510107034D00492
The same with embodiment 1-1 to 1-7, the initial charge capacity and the cycle characteristics of the secondary cell of the acquisition of measurement embodiment 20-1 to 20-10.The result provides in table 22 and Figure 19.
From table 22 and Figure 19, it is evident that, obtain the result identical with embodiment 8-1 to 8-10.In other words, even find to use gel electrolyte, when negative active core-shell material comprises 14.9 weight % or titanium still less, also can further improve cycle characteristics, and Ti content is 2.4 weight % or bigger more preferably, more preferably 4.0 weight % to 12.9 weight % (comprising end points).
(embodiment 21-1 to 21-8)
Equally form secondary cell with embodiment 15-1 to 15-9, different is shown in table 23, the material that uses wherein titanium and indium than the scope of 0 weight % to 10 weight % (comprising end points) in, change and Co/ (Sn+Co) ratio and carbon and silicon materials than fixing negative active core-shell material, i.e. the negative active core-shell material that equally synthesizes with embodiment 11-1 to 11-8.
The same with embodiment 1-1 to 1-7, the initial charge capacity and the cycle characteristics of the secondary cell of the acquisition of measurement embodiment 21-1 to 21-8.The result provides in table 24.
[table 23]
Figure C200510107034D00501
[table 24]
Initial charge capacity (mAh/g) Discharge capacity (mAh/cm in circulating for the second time 3) Discharge capacity (mAh/cm in the 300th circulation 3) Capability retention (%)
Embodiment 20-1 501 111 77 69
Embodiment 21-1 540 117 75 64
Embodiment 21-2 562 118 86 73
Embodiment 21-3 570 120 90 75
Embodiment 21-4 572 120 91 76
Embodiment 21-5 559 118 89 76
Embodiment 21-6 567 119 91 76
Embodiment 21-7 568 119 91 76
Embodiment 21-8 563 118 88 74
From table 24, it is evident that, obtain the result identical with embodiment 11-1 to 11-8.In other words, even find to use gel electrolyte, when negative active core-shell material comprises at least a and silicon that is selected from titanium, molybdenum, niobium, aluminium, germanium, indium, gallium and phosphorus, also can further improve capacity and cycle characteristics.
(embodiment 22-1 to 22-3)
Equally form secondary cell with embodiment 15-5, the different wherein 4-fluoro-1 that are to use, 3-dioxolanes-2-ketone, ethylene carbonate and propylene carbonate be with mass ratio 4-fluoro-1,3-dioxolanes-2-ketone: the solvent that ethylene carbonate: propylene carbonate=1:10.5:11.5,5:6.5:11.5 or 10:1.5:11.5 mix.
The same with embodiment 1-1 to 1-7, the cycle characteristics of the secondary cell that measurement embodiment 22-1 to 22-3 obtains.The result provides in table 25.
[table 25]
Figure C200510107034D00511
EC: ethylene carbonate
PC: propylene carbonate
Figure C200510107034D00512
FEC:4-fluoro-1,3-dioxolanes-2-ketone
It is evident that from table 25 therein with 4-fluoro-1,3-dioxolanes-2-ketone is used for the embodiment 22-1 to 22-3 of solvent, and wherein do not use 4-fluoro-1, the embodiment 15-5 of 3-dioxolanes-2-ketone compares, and can further improve capability retention.In other words, find under the situation of the cyclic carbonate that in solvent, comprises halogen atom,, also can further improve cycle characteristics even use gel electrolyte.
(embodiment 23-1 to 23-7)
Form negative active core-shell material.As negative active core-shell material, preparation cobalt powder, glass putty, iron powder and carbon dust, and in that cobalt powder, glass putty and iron powder alloying formation cobalt-Xi-iron alloy powder is last, carbon dust is added in the alloy powder, and, form mixture thus with its dried mixing.At this moment, shown in table 26 as material proportion, be 37 weight % with Co/ (Sn+Co) fixed ratio, be 0.8 weight % with the fixed ratio of iron, and the ratio of carbon change in the scope of 10 weight % to 30 weight % (comprising end points).Then, the steel ball of this mixture of 20g with about 400g diameter 9mm dropped in the reactor of Ito Seisakusho planetary ball mill.Then argon gas atmosphere is introduced in the reactor, and 10 minute operation and 10 minute at interval the circulation of repetition under 250rpm, reach 30 hours until total run time.Then, reactor is cooled to room temperature, and from reactor, takes out synthetic negative active core-shell material powder, this negative active core-shell material is moved through 280 purpose sieves, to remove the coarse granule of negative active core-shell material powder.
Analyze the composition of the negative active core-shell material that obtains.Measure carbon content by carbon/sulfur analyzer, and pass through the content of ICP (inductively coupled plasma) emission spectroscopy measurements cobalt, tin and iron.Assay value provides in table 26.In addition, when the negative active core-shell material to each acquisition carries out X-ray diffraction, ° to 50 ° of scopes, observe diffraction maximum with wide half width in 2 θ=20.Give the half width of diffraction maximum in the table 26.In addition, when carrying out XPS measuring, obtain peak P1 according to the negative active core-shell material to acquisition shown in Figure 6.When analyzing peak P1, obtain the peak P2 of surface contamination carbon and the peak P3 of the Cls in the negative active core-shell material of the energy lower one side than peak P2.In each embodiment 23-1 to 23-7, in being lower than the zone of 284.5eV, obtain peak P3.In other words, confirm carbon in each negative active core-shell material and other element coupling.
[table 26]
Figure C200510107034D00531
Figure C200510107034D00532
Then, the negative active core-shell material powder among each embodiment 23-1 to 23-7 is used to form Coin shape secondary cell shown in Figure 7, and measures the initial charge capacity of this secondary cell.This Coin-shaped battery comprises the test electrode 61 of the negative active core-shell material that uses each embodiment, and it is included in the packaging element 62 and to electrode 63, it is connected with packaging element 64.This test electrode 61 and electrode 63 had barrier film 65 laminated with the electrolyte solution impregnation between them, then with it by liner 66 calkings, form Coin-shaped battery thus.
Test electrode 61 forms as follows.At first, the negative active core-shell material that 70 weight portions are obtained, 20 weight portion graphite (it be electric conductor and other negative active core-shell material), 1 weight portion mix the formation mixture as the acetylene black of electric conductor and 4 weight portions as the polyvinylidene fluoride of binding agent.This mixture is scattered in the suitable solvent form slurry after, this slurry is applied on the Copper Foil collector and dry, then this collector is embossed to the sheet of diameter 15.2mm.
As to electrode 63, use to be embossed into the discoidal lithium metal plate of diameter as 15.5mm.For electrolyte solution, use the LiPF that wherein dissolves as electrolytic salt 6The mixed solvent that comprises ethylene carbonate, propylene carbonate and dimethyl carbonate.
For initial charge capacity, by being charged to cell voltage with constant current 1mA, this secondary cell reaches 0.2mV, charge to electric current with constant voltage 0.2mV then and reach 10 μ A, measure the charging capacity of per unit mass (it is the quality of test electrode 61 of removing the quality of the quality of Copper Foil collector and binding agent).In the case, charging is meant that lithium enters the insertion reaction in the negative active core-shell material.The result provides in table 26 and Figure 20.
In addition, form cylindrical secondary battery shown in Figure 1.At first, the positive electrode active materials that will make by nickel oxide, black and more black with quality: polyvinylidene fluoride=94:3:3 mixing formation mixture than nickel oxide: ketjen as the polyvinylidene fluoride of binding agent as the ketjen of electric conductor.This mixture is dispersed in mixed solvent such as the N-N-methyl-2-2-pyrrolidone N-form the cathode mix slurry after, this cathode mix slurry evenly is applied on the plus plate current-collecting body 21A two sides of being made by the bar shaped aluminium foil, and dry.Then, form anode active material layer 21B, so that form anodal 21 by the roller press compression molding.Then, positive wire made of aluminum 25 is connected to plus plate current-collecting body 21A end.
In addition, will evenly be applied on the negative current collector 22A two sides of making by the slurry that comprises negative active core-shell material that forms as mentioned above by the bar shaped Copper Foil, and dry.Then, form anode active material layer 22B, so that form negative pole 22 by the roller press compression molding.Then, will be connected with the end of negative current collector 22A by the negative wire 26 that nickel is made.
After forming positive pole 21 and negative pole 22, preparation barrier film 23, and with negative pole 22, barrier film 23, positive pole 21 and barrier film 23 lamination formation in this order laminate, and with this laminate screw winding repeatedly, to form spiral winding electrode 20.
After forming spiral winding electrode 20, spiral winding electrode 20 is clamped between a pair of insulation board 12 and 13, negative wire 26 is soldered to battery case 11, and this positive wire 25 is soldered to relief valve mechanism 15.Then, spiral winding electrode 20 is included in the battery case of being made by the iron of nickel plating 11.Then, above-mentioned electrolyte solution is injected battery case 11 by decomposition method.
After electrolyte solution injects battery case 11, battery cover 14 there are 17 pairs of battery case 11 calkings of liner of pitch by its surface coated, obtain cylindrical secondary battery shown in Figure 1 thus.
Measure the cycle characteristics of gained secondary cell.The result provides in table 26 and Figure 20.At this moment, measure cycle characteristics as follows.
At first, this secondary cell being charged to constant current 0.5A after cell voltage reaches 4.2V, this secondary cell is charged to electric current with constant voltage 4.2V reach 10mA.Then this secondary cell is discharged to cell voltage with constant current 0.25A and reaches 2.6V.The circulation first time that so discharges and recharges.
For the second time or circulation subsequently, secondary cell is being charged to constant current 1.4A after cell voltage reaches 4.2V, this secondary cell is charged to electric current with constant voltage 4.2V reach 10mA, then this secondary cell is discharged to cell voltage with constant current 1.0A and reaches 2.6V.For cycle characteristics, measure the 300th circulation capability retention (discharge capacity in the 300th circulation)/(discharge capacity in the circulation for the second time) x100 (%) to the discharge capacity in the circulation for the second time.
As the comparative example 23-1 with respect to embodiment 23-1 to 23-7, the same with the situation of embodiment 23-1 to 23-7, synthetic negative active core-shell material also forms secondary cell, and different is as material, not use carbon dust.In addition, 23-2 to 23-6 is the same with the situation of embodiment 23-1 to 23-7 as a comparative example, and synthetic negative active core-shell material also forms secondary cell, and different is, with the carbon powder material ratio by changing shown in the table 26.To the negative active core-shell material of comparative example 23-1 to 23-6 carry out composition analysis and in 2 θ=20 ° to 50 ° of scopes observed half width with diffraction maximum of wide half width measure.The result provides in table 26.In addition, when the negative active core-shell material to comparative example 23-1 to 23-6 carries out XPS measuring, in the negative active core-shell material of comparative example 23-1 to 23-6, obtain the peak P1 shown in Fig. 6.When analyzing peak P1, the same with embodiment 23-1 to 23-7, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and obtain the peak P3 among each comparative example 23-3 to 23-6 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.On the other hand, in comparative example 23-1, as shown in Figure 9, obtain peak P4, and when analyzing peak P4, only obtain the peak P2 of surface contamination carbon.At comparative example 23-2, very little as the carbon amount of material, only obtain peak P2 by analyzing like this, and almost detect less than peak P3.
In addition, measure initial charge capacity and cycle characteristics according to identical mode.The result also provides in table 26 and Figure 20.
From table 26 and Figure 20, it is evident that, carbon content in the negative active core-shell material is among the embodiment 23-1 to 23-7 of 9.9 weight to 29.7 weight % (comprising end points) therein, compare at this extraneous comparative example 23-1 to 23-6 with carbon content wherein, can obviously improve capability retention.In addition, can improve initial charge capacity and discharge capacity.
In addition, the carbon content in negative active core-shell material is 14.9 weight % to 29.7 weight % (comprising end points), and more specifically 16.8 weight % to 24.8 weight % can obtain higher value when (comprising end points).
In other words, find that carbon content is that 9.9 amount % to 29.7 weight % are when (comprising end points), can improve capacity and cycle characteristics, and carbon content more preferably 14.9 weight % to 29.7 weight % (comprising end points), more preferably 16.8 weight % to 24.8 weight % (comprising end points).
(embodiment 24-1 to 24-9)
Equally form secondary cell with embodiment 23-1 to 23-7, different is that synthetic wherein cobalt, tin, iron and material with carbon element are than the negative active core-shell material of variation shown in table 27.More specifically, be 0.8 weight % with the iron material fixed ratio, the material with carbon element ratio is fixed as 10 weight %, Co/ (Sn+Co) ratio changes in the scope of 30 weight % to 70 weight % (comprising end points).
[table 27]
Figure C200510107034D00571
As comparative example 24-1 to 24-4 with respect to embodiment 24-1 to 24-9, the same with embodiment 24-1 to 24-9, form negative active core-shell material and secondary cell, different is that Co/ (Sn+Co) ratio is according to changing shown in the table 27.Co/ among comparative example 24-1,24-2,24-3 and the 24-4 (Sn+Co) ratio is respectively 28 weight %, 25 weight %, 20 weight % and 75 weight %.
The same with embodiment 23-1 to 23-7, to the negative active core-shell material of the acquisition of embodiment 24-1 to 24-9 and comparative example 24-1 to 24-4 carry out composition analysis and in 2 θ=20 ° to 50 ° of scopes observed half width with diffraction maximum of wide half width measure.The result provides in table 27.In addition, the same with embodiment 23-1 to 23-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the district that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, the same with embodiment 23-1 to 23-7, the initial charge capacity and the cycle characteristics of measurement secondary cell.The result provides in table 27 and Figure 21.
From table 27 and Fig. 2, it is evident that, Co/ (Sn+Co) ratio is among the embodiment 24-1 to 24-9 of 30 weight % to 70 weight % (comprising end points) therein, the comparative example 24-1 to 24-3 that is lower than 30 weight % with Co/ (Sn+Co) ratio wherein compares, can obviously improve capability retention, and the comparative example 2-4 that is higher than 70 weight % with Co/ (Sn+Co) ratio wherein compares, and can obviously improve initial charge capacity.More specifically, when Co/ (Sn+Co) ratio is equal to or less than 60 weight %, can obtain high initial charge capacity.
In other words, find when Co/ (Sn+Co) ratio be 30 weight % to 70 weight % when (comprising end points), can improve capacity and cycle characteristics.Also find Co/ (Sn+Co) ratio 60 weight % or lower more preferably.
(embodiment 25-1 to 25-9)
Equally form secondary cell with embodiment 23-1 to 23-7, different is that synthetic wherein cobalt, tin, iron and material with carbon element are than the negative active core-shell material of variation shown in table 28.More specifically, the material ratio of iron is fixed as 0.8 weight %, the material with carbon element ratio is fixed as 20 weight %.Co/ (Sn+Co) ratio changes in the scope of 30 weight % to 70 weight % (comprising end points).
[table 28]
As comparative example 25-1 to 25-4 with respect to embodiment 25-1 to 25-9, the same with embodiment 25-1 to 25-9, form negative active core-shell material and secondary cell, different is that Co/ (Sn+Co) ratio is according to changing shown in the table 28.Co/ among comparative example 25-1,25-2,25-3 and the 25-4 (Sn+Co) ratio is respectively 28 weight %, 25 weight %, 20 weight % and 75 weight %.
The same with embodiment 23-1 to 23-7, to the negative active core-shell material of embodiment 25-1 to 25-9 and comparative example 25-1 to 25-4 carry out composition analysis and in 2 θ=20 ° to 50 ° of scopes observed half width with diffraction maximum of wide half width measure.The result provides in table 28.In addition, the same with embodiment 23-1 to 23-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the district that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, the same with embodiment 23-1 to 23-7, the initial charge capacity and the cycle characteristics of measurement secondary cell.The result provides in table 28 and Figure 22.
From table 28 and Figure 22, it is evident that, obtain those identical results with embodiment 24-1 to 24-9.Promptly find when Co/ (Sn+Co) ratio be 30 weight % to 70 weight % when (comprising end points), even z therein carbon content be under the situation of 19.8 weight %, also can improve capacity and cycle characteristics.
(embodiment 26-1 to 26-9)
Equally form secondary cell with embodiment 23-1 to 23-7, different is that synthetic wherein cobalt, tin, iron and material with carbon element are than the negative active core-shell material of variation shown in table 29.More specifically, be 0.8 weight % with the iron material fixed ratio, and the material with carbon element ratio is fixed as 30 weight %.Co/ (Sn+Co) ratio changes in 30 weight % to 70 weight % (comprising end points) scopes.
[table 29]
Figure C200510107034D00611
As comparative example 26-1 to 26-4 with respect to embodiment 26-1 to 26-9, the same with embodiment 26-1 to 26-9, form negative active core-shell material and secondary cell, different is that Co/ (Sn+Co) ratio is according to changing shown in the table 29.Co/ among comparative example 26-1,26-2,26-3 and the 26-4 (Sn+Co) ratio is respectively 28 weight %, 25 weight %, 20 weight % and 75 weight %.
The same with embodiment 23-1 to 23-7, to the negative active core-shell material of embodiment 26-1 to 26-9 and comparative example 26-1 to 26-4 carry out composition analysis and in 2 θ=20 ° to 50 ° of scopes observed half width with diffraction maximum of wide half width measure.The result provides in table 29.In addition, the same with embodiment 23-1 to 23-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the district that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, measure the initial charge capacity and the cycle characteristics of secondary cell by identical mode.The result provides in table 29 and Figure 23
From table 29 and Figure 23, it is evident that, obtain those identical results with embodiment 24-1 to 24-9.Promptly find when Co/ (Sn+Co) ratio be 30 weight % to 70 weight % when (comprising end points), even carbon content is under the situation of 29.7 weight % therein, also can improve capacity and cycle characteristics.
(embodiment 27-1 to 27-6 and 28-1 to 28-6)
Equally form active material and secondary cell with embodiment 23-1 to 23-7, different is changes operating time and revolution when synthetic negative active core-shell material, to change in 2 θ=20 ° to 50 ° of observed half widths with diffraction maximum of wide half width of scope.At this moment, in the material with carbon element ratio of cobalt, tin, iron and carbon, according to the material with carbon element ratio that changes shown in the table 30 among embodiment 27-1 to 27-6 and the embodiment 28-1 to 28-6, and Co/ (Sn+Co) ratio is identical.
[table 30]
Figure C200510107034D00631
Figure C200510107034D00632
The same with embodiment 23-1 to 23-7, to the negative active core-shell material of embodiment 27-1 to 27-6 and 28-1 to 28-6 carry out composition analysis and in 2 θ=20 ° to 50 ° of scopes observed half width with diffraction maximum of wide half width measure.The result provides in table 30.In addition, the same with embodiment 23-1 to 23-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the zone that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, equally measure the initial charge capacity and the cycle characteristics of secondary cell with embodiment 23-1 to 23-7.The result provides in table 30.
It is evident that from table 30 in embodiment 27-1 to 27-6 and 28-1 to 28-6, half width is big more, capability retention improves big more.In other words, when the half width of discovery diffraction maximum has bigger reacting phase, can improve cycle characteristics.
(embodiment 29-1 to 29-9)
Equally form secondary cell with embodiment 23-1 to 23-7, different is the negative active core-shell material of the material of synthetic wherein cobalt, tin, iron and carbon than variation shown in table 31.More specifically, the material of iron is than changing in 0.1 weight % to 7.0 weight % (comprising end points) scope.Co/ (Sn+Co) fixed ratio is 37 weight %, and the material of carbon ratio is fixed as 20 weight %.
[table 31]
Figure C200510107034D00641
Figure C200510107034D00642
The same with embodiment 23-1 to 23-7, to the negative active core-shell material of embodiment 29-1 to 29-9 carry out composition analysis and in 2 θ=20 ° to 50 ° of scopes observed half width with diffraction maximum of wide half width measure.The result provides in table 31.In addition, the same with embodiment 23-1 to 23-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the district that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 31 and Figure 24.
From table 31 and Figure 24, it is evident that, iron content is among the embodiment 29-3 to 29-7 of 0.3 weight % to 5.9 weight % (comprising end points) therein, the embodiment 29-1 that is lower than 0.3 weight % with iron content wherein compares with 29-2, can improve capability retention, and the embodiment 29-8 greater than 5.9 weight % compares with 29-9 with iron content wherein, can improve initial charge capacity.
In other words, find when iron content be 0.3 weight % to 5.9 weight % when (comprising end points), can improve capacity and cycle characteristics.
(embodiment 30-1 to 30-11)
Equally form negative active core-shell material and secondary cell with embodiment 23-1 to 23-7, different is that silica flour further is used as material, and the material of its cobalt, tin, iron, carbon and silicon is than variation shown in table 32.More specifically, the material of silica flour ratio changes in 0.3 weight % to 10 weight % (comprising end points) scope, and Co/ (Sn+Co) ratio, iron material ratio and material with carbon element ratio is fixing.The same with embodiment 23-1 to 23-7, the secondary cell of embodiment 30-1 to 30-11 is carried out composition analysis.The result provides in table 32.Silicone content is by the ICP emission spectrometry.In addition, the same with embodiment 23-1 to 23-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the district that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 33.
[table 32]
Figure C200510107034D00661
Figure C200510107034D00662
[table 33]
Initial charge capacity (mAh/g) Discharge capacity (mAh/cm in circulating for the second time 3) Discharge capacity (mAh/cm in the 300th circulation 3) Capability retention (%)
Embodiment 23-5 518 139 101 73
Embodiment 30-1 519 140 102 73
Embodiment 30-2 525 142 100 71
Embodiment 30-3 544 144 101 70
Embodiment 30-4 556 146 99 68
Embodiment 30-5 570 147 98 67
Embodiment 30-6 586 152 101 66
Embodiment 30-7 603 156 101 65
Embodiment 30-8 614 158 93 59
Embodiment 30-9 630 158 66 42
Embodiment 30-10 653 160 42 26
Embodiment 30-11 680 162 19 12
From table 32 and 33, it is evident that, comprise therein among the embodiment 30-1 to 30-11 of silicon, compare, can further improve initial charge capacity with the embodiment 23-5 that does not wherein comprise silicon.Yet, the trend that exists capability retention to raise and reduce with silicone content.
In other words, find when silicon is included in the negative active core-shell material, can improve capacity, and silicone content to be preferably 0.5 weight % to 7.9 weight % (comprising end points).
(embodiment 31-1 to 31-10)
In embodiment 31-1, the same with embodiment 23-1 to 23-7, synthetic negative active core-shell material also forms secondary cell, and the material of different is cobalt, tin, iron and carbon is than by changing shown in the table 34.In embodiment 31-2 to 31-10, the same with embodiment 23-1 to 23-7, synthetic negative active core-shell material also forms secondary cell, and different is to prepare cobalt powder, glass putty, iron powder, carbon dust and titanium valve as material, and its material proportion is pressed variation shown in the table 34.More specifically, the material of titanium is than variation in 0 weight % to 16 weight % (comprising end points) scope, and fixation of C o/ (Sn+Co) ratio, the material ratio of iron and the material ratio of carbon.In addition, negative active core-shell material by with cobalt powder, glass putty, iron powder and titanium valve alloying to form cobalt-Xi-iron-titanium alloy powder, then carbon dust is sneaked in this alloyed powder and synthesizes.The same with embodiment 23-1 to 23-7, the negative active core-shell material of embodiment 31-1 to 31-10 is carried out composition analysis.The result provides in table 34.Ti content is by the ICP emission spectrometry.In addition, the same with embodiment 23-1 to 23-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the district that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, by identical mode, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 34 and Figure 25,
[table 34]
Figure C200510107034D00691
Figure C200510107034D00692
From table 34 and Figure 25, it is evident that, comprise 14.9 weight % therein or still less among the embodiment 31-2 to 31-9 of titanium, with the embodiment 31-1 that does not wherein comprise titanium with compare comprising the embodiment 31-10 that surpasses 14.9 weight % titaniums, can improve capability retention.In addition, when Ti content is equal to or higher than 2.4 weight %, in the time of more preferably in 4.0 weight % to 12.9 weight % (comprising end points) scopes, can obtain higher value.
In other words, find when comprising 14.9 weight % or titanium still less in the negative active core-shell material, can further improve cycle characteristics, and particularly, more preferably be included in the titanium in 4.0 weight % to 12.9 weight % (the comprising end points) scopes.
(embodiment 32-1 to 32-9)
Equally synthesize negative active core-shell material and form secondary cell with embodiment 23-1 to 23-7, different is to prepare cobalt powder, glass putty, iron powder, carbon dust and bismuth meal as material, and its material changes than pressing shown in the table 35.More specifically, the material of bismuth ratio changes in 1.2 weight % to 16.0 weight % (comprising end points) scopes, and Co/ (Sn+Co) ratio, iron material ratio and material with carbon element ratio is fixing.In addition, negative active core-shell material by with cobalt powder, glass putty, iron powder and bismuth meal alloying to form cobalt-Xi-iron-bismuth alloy powder, then carbon dust is sneaked in this alloyed powder and synthesizes.The same with embodiment 23-1 to 23-7, the anticathode active material carries out composition analysis.The result provides in table 35.Bi content is by the ICP emission spectrometry.In addition, the same with embodiment 23-1 to 23-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the district that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, by identical mode, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 35 and Figure 26.
[table 35]
Figure C200510107034D00701
Figure C200510107034D00711
Figure C200510107034D00712
As table 35 and shown in Figure 26, add therein among the embodiment 32-1 to 32-9 of bismuth, obtain those identical results with the embodiment 31-2 to 31-10 that wherein adds titanium.In other words, when finding in negative active core-shell material, to comprise 14.9 weight % or bismuth still less, cycle characteristics be can further improve, and 4.0 weight % or more bismuth more preferably comprised.
(embodiment 33-1 to 33-14)
Equally synthesize negative active core-shell material and form secondary cell with embodiment 23-1 to 23-7, different is preparation cobalt powder, glass putty, iron powder, carbon dust and molybdenum powder, niobium powder, aluminium powder, germanium powder, indium powder, gallium powder, phosphorus powder or aluminium powder and phosphorus powder be as material, and with the material of cobalt, tin, iron, carbon and molybdenum, niobium, aluminium, germanium, indium, gallium, phosphorus or aluminium and phosphorus than pressing variation shown in the table 36.More specifically, the material of molybdenum, niobium, aluminium, germanium, indium, gallium, phosphorus or aluminium and phosphorus ratio is 3 weight %, 4 weight %, 5 weight % or 6 weight %, and is 35 weight % with Co/ (Sn+Co) fixed ratio, and the material ratio of iron is fixed as 0.8 weight %.In addition, negative active core-shell material is by forming cobalt-Xi-iron alloy powder with cobalt powder, glass putty and iron powder alloying, then carbon dust and molybdenum powder, niobium powder, aluminium powder, germanium powder, indium powder, gallium powder, phosphorus powder or aluminium powder and phosphorus powder sneaked in the alloy powder and synthesizes.The same with embodiment 23-1 to 23-7, the negative active core-shell material of embodiment 33-1 to 33-14 is carried out composition analysis.The result provides in table 36.The content of molybdenum, niobium, aluminium, germanium, indium, gallium and phosphorus is by the ICP emission spectroscopy measurements.In addition, the same with embodiment 23-1 to 23-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the district that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, by identical mode, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 37.
[table 36]
Figure C200510107034D00731
Figure C200510107034D00732
[table 37]
Initial charge capacity (mAh/g) Discharge capacity (mAh/cm in circulating for the second time 3) Discharge capacity (mAh/cm in the 300th circulation 3) Capability retention (%)
Embodiment 31-1 525 139 101 73
Embodiment 33-1 505 136 112 82
Embodiment 33-2 503 138 115 83
Embodiment 33-3 531 140 120 86
Embodiment 33-4 526 139 118 85
Embodiment 33-5 527 138 117 85
Embodiment 33-6 551 141 114 81
Embodiment 33-7 547 143 120 84
Embodiment 33-8 536 142 118 83
Embodiment 33-9 536 139 114 82
Embodiment 33-10 539 139 115 83
Embodiment 33-11 544 144 124 86
Embodiment 33-12 519 137 115 84
Embodiment 33-13 535 141 114 81
Embodiment 33-14 554 146 117 80
Shown in table 36 and 37, the same with embodiment 31-2 to 32-10 in embodiment 33-1 to 33-14 with 32-1 to 32-9, can improve cycle characteristics.In other words, find to comprise when being selected from least a in molybdenum, niobium, aluminium, germanium, indium, gallium and the phosphorus, further the modification cycle characteristics when negative active core-shell material.
(embodiment 34-1 to 34-8)
Equally synthesize negative active core-shell material and form secondary cell with embodiment 23-1 to 23-7, different is to prepare cobalt powder, glass putty, iron powder, carbon dust, silica flour, titanium valve and indium powder as material, and its material proportion is pressed variation shown in the table 38.More specifically, with the material of titanium or titanium and indium than 0 weight % to 10 weight % (comprising end points) scope in, changing, and with Co/ (Sn+Co) ratio, iron material than the material of, carbon than and the material of silicon than fixing.In addition, negative active core-shell material is by forming cobalt-Xi-iron-titanium alloy powder or cobalt-Xi-titanium-titanium-indium alloy powder with cobalt powder, glass putty, iron powder and titanium valve or cobalt powder, glass putty, iron powder, titanium valve and indium powder alloying, then carbon dust and silica flour sneaked in the alloy powder and synthesizes.The same with embodiment 23-1 to 23-7, the negative active core-shell material of embodiment 34-1 to 34-8 is carried out composition analysis.The result provides in table 39.In addition, the same with embodiment 23-1 to 23-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the district that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, by identical mode, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 39.
[table 38]
Figure C200510107034D00751
Figure C200510107034D00752
[table 39]
Initial charge capacity (mAh/g) Discharge capacity (mAh/cm in circulating for the second time 3) Discharge capacity (mAh/cm in the 300th circulation 3) Capability retention (%)
Embodiment 31-1 525 139 101 73
Embodiment 34-1 563 147 100 68
Embodiment 342 587 148 114 77
Embodiment 34-3 594 149 118 79
Embodiment 34-4 597 150 117 78
Embodiment 34-5 583 147 116 79
Embodiment 34-6 592 149 116 78
Embodiment 34-7 594 149 118 79
Embodiment 34-8 587 148 112 76
It is evident that from table 38 and 39 silica removal also adds among the embodiment 34-2 to 34-8 of titanium or titanium and indium therein outward, compare with 34-1, can further improve initial charge capacity and capability retention with the embodiment 31-1 that does not wherein comprise them.
In other words, find when at least a and silicon that will be selected from titanium, molybdenum, niobium, aluminium, germanium, indium, gallium, phosphorus and bismuth is included in the negative active core-shell material, can further improve capacity and cycle characteristics.
(embodiment 35-1 to 35-8)
With the equally synthetic negative active core-shell material of embodiment 23-1 to 23-7, different is that preparation cobalt powder, glass putty, iron powder, carbon dust, silica flour and titanium valve are as material, and cobalt powder, glass putty and iron powder or cobalt powder, glass putty, iron powder and titanium valve alloying form cobalt-Xi-iron alloy powder or or cobalt-Xi-iron-titanium alloy powder after, carbon dust or carbon dust and silica flour are sneaked in the alloy powder.At this moment, material proportion variation shown in table 40.In addition, the same with embodiment 23-1 to 23-7, form cylindrical secondary battery, different is to use negative active core-shell material in embodiment 35-1 to 35-4 and embodiment 35-5 to 35-8, and changes the composition of electrolyte solution.At this moment, in embodiment 35-1 to 35-4, using wherein will be as the LiPF of electrolytic salt 6Being dissolved in the mass ratio that comprises ethylene carbonate, propylene carbonate and dimethyl carbonate with ratio 1mol/l is ethylene carbonate: the electrolyte solution in the mixed solvent of propylene carbonate: dimethyl carbonate=30:10:60, and in embodiment 35-5 to 35-8, using wherein will be as the LiPF of electrolytic salt 6Be dissolved in ratio 1mol/l and comprise 4-fluoro-1, the mass ratio of 3-dioxolanes-2-ketone, ethylene carbonate, propylene carbonate and dimethyl carbonate is a 4-fluoro-1,3-dioxolanes-2-ketone: the electrolyte solution in the mixed solvent of ethylene carbonate: propylene carbonate: dimethyl carbonate=20:10:10:60.In embodiment 35-1 and 35-5, embodiment 35-2 and 35-6, embodiment 35-3 and 35-7 and embodiment 35-4 and 35-8, use identical negative active core-shell material.
[table 40]
Figure C200510107034D00771
EC: ethylene carbonate
Figure C200510107034D00772
PC: propylene carbonate
DMC: dimethyl carbonate
FEC:4-fluoro-1,3-dioxolanes-2-ketone
The same with embodiment 23-1 to 23-7, the negative active core-shell material of embodiment 35-1 to 35-8 is carried out composition analysis.The result provides in table 40.In addition, the same with embodiment 23-1 to 23-7, when carrying out XPS measuring and analyzing the peak that obtains, obtain the peak P2 of surface contamination carbon and the Cls peak P3 in the negative active core-shell material, and in each embodiment, obtain peak P3 in the district that is lower than 284.5eV.In other words, confirm to comprise in the negative active core-shell material to small part carbon and other element coupling.In addition, by identical mode, measure the initial charge capacity and the cycle characteristics of secondary cell.The result provides in table 40.
From table 40, it is evident that, therein with 4-fluoro-1,3-dioxolanes-2-ketone is as among the embodiment 35-5 to 35-8 of solvent, and wherein do not use 4-fluoro-1, the embodiment 35-1 to 35-4 of 3-dioxolanes-2-ketone compares, and can further improve capability retention.
(embodiment 36-1 to 36-18)
With the same cylindrical secondary battery that forms with 35-5 of embodiment 35-1, different is solvent composition variation shown in table 41.Equally measure the cycle characteristics of the secondary cell of embodiment 36-1 to 36-18 with embodiment 23-1 to 23-7.The result provides in table 41.
[table 41]
Figure C200510107034D00791
EC: ethylene carbonate
Figure C200510107034D00792
PC: propylene carbonate
DMC: dimethyl carbonate
FEC:4-fluoro-1,3-dioxolanes-2-ketone
It is evident that from table 41 along with 4-fluoro-1, the amount of 3-dioxolanes-2-ketone increases, capability retention rises to maximum, reduces then.
In other words, find when comprising 4-fluoro-13-dioxolanes-2-ketone, no matter the composition of solvent, all can improve cycle characteristics, and particularly, when 4-fluoro-1, the content of 3-dioxolanes-2-ketone is 0.1 weight % to 80 weight % when (comprising end points), can obtain higher effect
(embodiment 37-1 to 37-6).
The same with 35-5, form cylindrical secondary battery, different being to use comprises that the other derivative of the cyclic carbonate of halogen atom replaces 4-fluoro-1,3-dioxolanes-2-ketone.At this moment, in embodiment 37-1, use 4-two fluoro-1,3-dioxolanes-2-ketone, in embodiment 37-2, use 4-two fluoro-5-fluoro-1,3-dioxolanes-2-ketone uses 4-chloro-1,3-dioxolanes-2-ketone in embodiment 37-3, in embodiment 37-4, use 4-bromo-1,3-dioxolanes-2-ketone uses 4-iodo-1,3-dioxolanes-2-ketone in embodiment 37-5, in embodiment 37-6, use 4-methyl fluoride-1,3-dioxolanes-2-ketone.
The same with embodiment 23-1 to 23-7, measurement follows the cycle characteristics of the secondary cell of embodiment 37-1 to 37-6.The result provides in table 42.
[table 42]
Figure C200510107034D00801
EC: ethylene carbonate
Tri-FEC:4-two fluoro-5-fluoro-1,3-dioxolanes-2-ketone
PC: propylene carbonate C1-EC:4-chloro-1,3-dioxolanes-2-ketone
DMC: dimethyl carbonate Br-EC:4-bromo-1,3-dioxolanes-2-ketone
FEC:4-fluoro-1,3-dioxolanes-2-ketone
I-EC:4-iodo-1,3-dioxolanes-2-ketone
DFEC:4-two fluoro-1,3-dioxolanes-2-ketone
F-PC:4-methyl fluoride-1,3-dioxolanes-2-ketone
Figure C200510107034D00811
From table 42, it is evident that, even use the other derivative of the cyclic carbonate that comprises halogen atom, also with the same cycle characteristics that improves of embodiment 35-5.Yet, using 4-fluoro-1 therein, capability retention is high especially among the embodiment 35-5 of 3-dioxolanes-2-ketone.In other words, find can to improve cycle characteristics when comprise the cyclic carbonate derivative of halogen atom, and when comprising 4-fluoro-1,3-dioxolanes-2-ketone is during as derivative, and is effective especially aspect the improvement cycle characteristics.
(embodiment 38-1 to 38-7)
Equally form the Coin shape secondary cell with embodiment 23-1 to 23-7, different is to form the dielectric substrate that is made of gel electrolyte at test electrode 61 with on to the surface of electrode 63.In other words, will be by cobalt, tin, iron and carbon by being used for test electrode 61 than mixing the negative active core-shell material that synthesizes with the same material shown in the table 43 with among the embodiment 23-1 to 23-7.In addition, dielectric substrate forms as follows.At first, will be mixed in the electrolyte solution that (this electrolyte solution is by will be as the ethylene carbonate of solvent and propylene carbonate with as the LiPF of electrolytic salt as the copolymer of the vinylidene fluoride of high-molecular weight compounds and hexafluoropropylene with as the diethyl carbonate of mixed solvent 6By quality than ethylene carbonate: propylene carbonate: LiPF 6=11.5:11.5:4 mixes and forms) be electrolyte solution to have mass ratio: high-molecular weight compounds: mixed solvent=27:10:60 forms precursor solution thus.The molecular weight of the copolymer of vinylidene fluoride and hexafluoropropylene is 600000.The precursor solution that obtains evenly is applied on test electrode 61 and the opposed face to electrode 63, and it was at room temperature placed 6 hours so that the diethyl carbonate volatilization forms gel electrolyte layer thus.
[table 43]
Figure C200510107034D00822
The same with embodiment 23-1 to 23-7, the initial charge capacity of the Coin shape secondary cell that measurement obtains.The result provides in table 43 and Figure 27.
In addition, the secondary cell of formation shown in Fig. 3 and 4.At first equally form positive pole 33 and negative pole 34, and connect positive wire 31 and negative wire 32 with embodiment 23-1 to 23-7.
Then, above-mentioned precursor solution evenly is applied on positive pole 33 and the negative pole 34, and it was at room temperature placed 6 hours so that the diethyl carbonate volatilization forms gel electrolyte layer 36 thus.
Then, positive pole 33 and negative pole 34 are had barrier film 35 laminated betwixt,, form laminate thus, and the laminate screw winding is formed spiral winding electrode 30 so that form the positive pole 33 of dielectric substrate 36 on it and the surface of negative pole 34 is faced mutually.
With obtaining spiral winding electrode 30 vacuum seals in the packaging element 40 that the ironed film of damp proof aluminium lamination is made, form the secondary cell shown in Fig. 3 and 4 thus.
The same with embodiment 23-1 to 23-7, the cycle characteristics of measurement secondary cell.The result provides in table 43 and Figure 27.
As comparative example 38-1 to 38-6 with respect to embodiment 38-1 to 38-7, equally form secondary cell with embodiment 23-1 to 23-7, different is to use by mixing the synthetic negative active core-shell material of cobalt, tin, iron and carbon by the ratio of the material shown in the table 43, promptly with the equally synthetic negative active core-shell material of comparative example 23-1 to 23-7.
Measure the initial charge capacity and the cycle characteristics of the secondary cell of comparative example 38-1 to 38-6 acquisition.The result provides in table 43 and Figure 27.
From table 43 and Figure 27, it is evident that, obtain with embodiment 23-1 to 23-7 in those identical results.In other words, even find to use gel electrolyte, in the time of in carbon content is 9.9 weight % to 29.7 weight % (comprising end points) scopes, can improve capacity and cycle characteristics, and carbon content is 14.9 weight % to 29.7 weight % more preferably, more preferably 16.8 weight % to 24.8 weight %.
(embodiment 39-1 to 39-9,40-1 to 40-9 and 41-1 to 41-9)
For embodiment 39-1 to 39-9, equally form secondary cell with embodiment 38-1 to 38-7, different is shown in table 44, using wherein, the material ratio of carbon is fixed as 10 weight %, and the material of iron ratio is fixed as 0.8 weight %, and the negative active core-shell material that in 30 weight % to 70 weight % (comprising end points) scopes, changes of Co/ (Sn+Co) ratio, promptly with the equally synthetic negative active core-shell material of embodiment 24-1 to 24-9.In addition, as comparative example 39-1 to 39-4 with respect to embodiment 39-1 to 39-9, equally form secondary cell with embodiment 39-1 to 39-9, different is shown in table 44, using wherein, the material ratio of carbon is fixed as 10 weight %, and the iron material ratio is fixed as 0.8 weight %, and Co/ (Sn+Co) ratio is the negative active core-shell material of 28 weight %, 25 weight %, 20 weight % and 75 weight %, promptly with the equally synthetic negative active core-shell material of comparative example 24-1 to 24-4.
[table 44]
Figure C200510107034D00841
For embodiment 40-1 to 40-9, equally form secondary cell with embodiment 38-1 to 38-9, different is shown in table 45, use the quantity of material of carbon wherein to be fixed as 20 weight %, iron material ratio and be fixed as the negative active core-shell material that 0.8 weight % and Co/ (Sn+Co) ratio change in 30 weight % to 70 weight % (comprising end points) scopes, promptly with the equally synthetic negative active core-shell material of embodiment 25-1 to 25-9.In addition, as comparative example 40-1 to 40-4 with respect to embodiment 40-1 to 40-9, equally form secondary cell with embodiment 40-1 to 40-9, different is shown in table 45, using wherein, the material ratio of carbon is fixed as 20 weight %, the iron material ratio is fixed as 0.8 weight % and Co/ (Sn+Co) ratio is the negative active core-shell material of 28 weight %, 25 weight %, 20 weight % and 75 weight %, promptly with the equally synthetic negative active core-shell material of comparative example 25-1 to 25-4.
[table 45]
Figure C200510107034D00851
For embodiment 41-1 to 41-9, equally form secondary cell with embodiment 38-1 to 38-7, different is shown in table 46, use the quantity of material of carbon wherein to be fixed as 30 weight %, iron material ratio and be fixed as the negative active core-shell material that 0.8 weight % and Co/ (Sn+Co) ratio change in 30 weight % to 70 weight % (comprising end points) scopes, promptly with the equally synthetic negative active core-shell material of embodiment 26-1 to 26-9.In addition, as comparative example 41-1 to 41-4 with respect to embodiment 41-1 to 41-9, equally form secondary cell with embodiment 41-1 to 41-9, different is shown in table 46, using wherein, the material ratio of carbon is fixed as 30 weight %, the iron material ratio is fixed as 0.8 weight % and Co/ (Sn+Co) ratio is the negative active core-shell material of 28 weight %, 25 weight %, 20 weight % and 75 weight %, promptly with the equally synthetic negative active core-shell material of comparative example 26-1 to 26-4.
[table 46]
The same with embodiment 23-1 to 23-7, measure embodiment 39-1 to 39-9,40-1 to 40-9 and 41-1 to 41-9 and comparative example 39-1 to 39-4, the initial capacity of the secondary cell of the acquisition of 40-1 to 40-4 and 41-1 to 41-4 and cycle characteristics.The result table 44 to 46 and Figure 28 to 30 in provide.
From table 44 to 46 and Figure 28 to 30 it is evident that, obtain with embodiment 24-1 to 24-9,25-1 to 25-9 and 26-1 to 26-9 in those identical results.In other words, find in Co/ (Sn+Co) ratio to be under the situation of 30 weight % to 70 weight % (comprising end points),, also can improve capacity and cycle characteristics even use gel electrolyte.In addition, find Co/ (Sn+Co) ratio 60 weight % or lower more preferably.
(embodiment 42-1 to 42-9)
Equally form secondary cell with embodiment 38-1 to 38-9, different is shown in table 47, use wherein Co/ (Sn+Co) ratio and material with carbon element than fixing and iron material than the negative active core-shell material that 0.1 weight % to 7 weight % (comprising end points) scope in, changes, i.e. the negative active core-shell material that equally synthesizes with embodiment 29-1 to 29-9.
[table 47]
Figure C200510107034D00871
The same with embodiment 23-1 to 23-9, the initial capacity and the cycle characteristics of the secondary cell of measurement embodiment 42-1 to 42-9.The result provides in table 47 and Figure 31.
From table 47 and Figure 31, it is evident that, obtain with embodiment 29-1 to 29-9 in those identical results.In other words, find at iron content to be under the situation of 0.4 weight % to 5.9 weight %,, also can improve capacity and cycle characteristics even use gel electrolyte.
(embodiment 43-1 to 43-11)
Equally form secondary cell with embodiment 38-1 to 38-7, different is shown in table 48, using wherein, silica flour material ratio changes in 0.3 weight % to 10 weight % (comprising end points) scope and Co/ (Sn+Co) ratio, iron material ratio and the fixing negative active core-shell material of material with carbon element ratio, the i.e. negative active core-shell material that equally synthesizes with embodiment 30-1 to 30-11.
The same with embodiment 23-1 to 23-7, the initial charge capacity and the cycle characteristics of the secondary cell that measurement embodiment 43-1 to 43-11 obtains.The result provides in table 49.
[table 48]
Figure C200510107034D00881
Figure C200510107034D00882
[table 49]
Initial charge capacity (mAh/g) Discharge capacity (mAh/cm in circulating for the second time 3) Discharge capacity (mAh/cm in the 300th circulation 3) Capability retention (%)
Embodiment 38-5 492 111 82 74
Embodiment 43-1 493 112 81 72
Embodiment 43-2 499 115 81 70
Embodiment 43-3 517 116 80 69
Embodiment 43-4 528 117 78 67
Embodiment 43-5 542 118 78 66
Embodiment 43-6 557 122 79 65
Embodiment 43-7 573 125 79 63
Embodiment 43-8 583 126 73 58
Embodiment 43-9 599 126 51 40
Embodiment 43-10 620 129 30 23
Embodiment 43-11 646 131 16 12
From table 48 and 49, it is evident that, obtain with embodiment 30-1 to 30-11 in those identical results.In other words, even find to use gel electrolyte, when comprising silicon in the negative active core-shell material, also can improve capacity, and silicone content is preferably 0.5 weight % to 7.9 weight % (comprising end points).
(embodiment 44-1 to 44-10)
Equally form secondary cell with embodiment 38-1 to 38-7, different is shown in table 50, using wherein, titanium material ratio changes in 0 weight % to 16 weight % (comprising end points) scope and Co/ (Sn+Co) ratio, iron material ratio and the fixing negative active core-shell material of material with carbon element ratio, the i.e. negative active core-shell material that equally synthesizes with embodiment 31-1 to 31-10.
[table 50]
Figure C200510107034D00901
The same with embodiment 23-1 to 23-7, the initial charge capacity and the cycle characteristics of the secondary cell that measurement embodiment 44-1 to 44-10 obtains.The result provides in table 50 and Figure 32.
From table 50 and Figure 32, it is evident that, obtain with embodiment 31-1 to 31-10 in those identical results.In other words, even find to use gel electrolyte, when comprising 14.9 weight % or titanium still less in the negative active core-shell material, also can further improve cycle characteristics, and Ti content is 2.4 weight % or bigger more preferably, more preferably 4.0 weight % to 12.9 weight % (comprising end points).
(embodiment 45-1 to 45-8)
Equally form secondary cell with embodiment 38-1 to 38-7, different is shown in table 51, the material that uses wherein titanium and indium than 0 weight % to 10 weight % (comprising end points) scope in, change and Co/ (Sn+Co) ratio, iron material than, material with carbon element than and silicon materials than fixing negative active core-shell material, i.e. the negative active core-shell material that equally synthesizes with embodiment 34-1 to 34-8.
The same with embodiment 23-1 to 23-7, the initial charge capacity and the cycle characteristics of the secondary cell of measurement embodiment 45-1 to 45-8.The result provides in table 52.
[table 51]
Figure C200510107034D00911
Figure C200510107034D00912
[table 52]
Initial charge capacity (mAh/g) Discharge capacity (mAh/cm in circulating for the second time 3) Discharge capacity (mAh/cm in the 300th circulation 3) Capability retention (%)
Embodiment 44-1 499 111 80 72
Embodiment 45-1 532 118 79 67
Embodiment 45-2 556 118 92 78
Embodiment 45-3 562 119 95 80
Embodiment 45-4 568 120 95 79
Embodiment 45-5 555 119 95 80
Embodiment 45-6 563 120 96 80
Embodiment 45-7 562 120 97 81
Embodiment 45-8 557 119 89 75
From table 51 and 52, it is evident that, obtain with embodiment 34-1 to 34-8 in those identical results.In other words, even find to use gel electrolyte, when comprising at least a and silicon that is selected from titanium, molybdenum, niobium, aluminium, germanium, indium, gallium, phosphorus and bismuth in the negative active core-shell material, also can further improve capacity and cycle characteristics.
(embodiment 46-1 to 46-3)
Equally form secondary cell with embodiment 38-5, the different wherein 4-fluoro-1 that are to use, 3-dioxolanes-2-ketone, ethylene carbonate and propylene carbonate are 4-fluoro-1 with the mass ratio, 3-dioxolanes-2-ketone: the solvent that ethylene carbonate: propylene carbonate=1:10.5:11.5 or 5:6.5:11.5 or 10:1.5:11.5 mix.
The same with embodiment 23-1 to 23-7, the cycle characteristics of the secondary cell that measurement embodiment 46-1 to 46-3 obtains.The result provides in table 53.
[table 53]
Figure C200510107034D00921
Figure C200510107034D00931
EC: ethylene carbonate
Figure C200510107034D00932
PC: propylene carbonate
FEC:4-fluoro-1,3-dioxolanes-2-ketone
It is evident that from table 53 therein with 4-fluoro-1,3-dioxolanes-2-ketone is used for the embodiment 46-1 to 46-3 of solvent, and wherein do not use 4-fluoro-1, the embodiment 38-5 of 3-dioxolanes-2-ketone compares, and can further improve capability retention.In other words, even find to use gel electrolyte, when in solvent, comprising the cyclic carbonate of halogen atom, also can further improve cycle characteristics.
Although the present invention is described with reference implementation mode and embodiment, the invention is not restricted to these execution modes and embodiment, and can carry out various changes.For embodiment, in superincumbent execution mode and the foregoing description, the present invention is described with reference to the secondary cell with Coin shape, sheet type and screw winding structure; Yet the present invention is applicable to the secondary cell with any other shape that uses button type packaging element, prismatic packaging element etc. and have wherein secondary cell with the laminar structure of a plurality of positive poles and a plurality of negative pole laminations.
In addition, in execution mode and embodiment, described wherein with the situation of lithium as the electrode reaction thing; Yet, 2 family's elements such as magnesium or calcium (Ca), other light metal such as aluminium or comprise lithium or the situation of the alloy of arbitrary above-mentioned material in any other 1 family element such as sodium (Na) or potassium (K), the microscler periodic table of elements in the present invention microscler applicable to wherein using (long form) periodic table of elements, as long as these materials can react with negative active core-shell material, and can obtain identical effect.At this moment, choose the positive electrode active materials that can insert and deviate from the electrode reaction thing, nonaqueous solvents etc. according to the electrode reaction thing.
It will be understood by those skilled in the art that according to designing requirement and other factors can carry out various improvement, combination, subgroup is closed and change, as long as they are in the scope of claims or its equivalent.

Claims (19)

1. negative active core-shell material, it comprise can with the reacting phase of lithium reaction, and described reacting phase comprises:
At least tin, cobalt and carbon,
Wherein carbon content is 9.9 weight % to 29.7 weight %, comprises end points, and cobalt is 30 weight % to 70 weight % to the ratio of tin and cobalt total amount, comprises end points.
2. according to the negative active core-shell material of claim 1, wherein
The 1s peak of carbon obtains in the zone that is lower than 284.5eV by the x-ray photoelectron spectroscopy method.
3. according to the negative active core-shell material of claim 1, wherein
The half width of the diffraction maximum of the described reacting phase that obtains by X-ray diffraction is 1.0 ° or bigger.
4. according to the negative active core-shell material of claim 1, further comprise:
Silicon.
5. according to the negative active core-shell material of claim 4, wherein
Silicone content is 0.5 weight % to 7.9 weight %, comprises end points.
6. according to the negative active core-shell material of claim 1, further comprise:
Be selected from least a of indium, niobium, germanium, titanium, molybdenum, aluminium, phosphorus, gallium and bismuth, its content is 14.9 weight % or lower.
7. according to the negative active core-shell material of claim 6, wherein
Comprise 2.4 weight % or higher be selected from least a of indium, niobium, germanium, titanium, molybdenum, aluminium, phosphorus, gallium and bismuth.
8. according to the negative active core-shell material of claim 1, further comprise:
Silicon, its content are 0.5 weight % to 7.9 weight %, comprise end points; With
Be selected from least a of indium, niobium, germanium, titanium, molybdenum, aluminium, phosphorus, gallium and bismuth, its content is 2.4 weight % to 14.9 weight %, comprises end points.
9. according to the negative active core-shell material of claim 1, further comprise iron.
10. battery comprises:
Anodal;
Negative pole; With
Electrolyte,
Wherein negative pole comprises negative active core-shell material, this negative active core-shell material comprise can with the reacting phase of lithium reaction, and described reacting phase comprises tin, cobalt and carbon at least, and
Carbon content in this negative active core-shell material is 9.9 weight % to 29.7 weight %, comprises end points, and cobalt is 30 weight % to 70 weight % to the ratio of tin and cobalt total amount, comprises end points.
11. according to the battery of claim 10, wherein
In negative active core-shell material, the peak of carbon obtains in the zone that is lower than 284.5eV by the x-ray photoelectron spectroscopy method.
12. according to the battery of claim 10, wherein
The half width of the diffraction maximum of the described reacting phase that obtains by X-ray diffraction is 1.0 ° or bigger.
13. according to the battery of claim 10, wherein
Negative active core-shell material further comprises silicon.
14. according to the battery of claim 13, wherein
Silicone content in negative active core-shell material is 0.5 weight % to 7.9 weight % (comprising end points).
15. according to the battery of claim 10, wherein
Negative active core-shell material comprises further and is selected from least a of indium, niobium, germanium, titanium, molybdenum, aluminium, phosphorus, gallium and bismuth that its content is 14.9 weight % or lower.
16. according to the battery of claim 15, wherein
Negative active core-shell material comprises 2.4 weight % or higher is selected from least a of indium, niobium, germanium, titanium, molybdenum, aluminium, phosphorus, gallium and bismuth.
17. according to the battery of claim 10, wherein
Negative active core-shell material further comprises silicon, and its content is 0.5 weight % to 7.9 weight %, comprises end points; Be selected from least a of indium, niobium, germanium, titanium, molybdenum, aluminium, phosphorus, gallium and bismuth, its content is 2.4 weight % to 14.9 weight %, comprises end points.
18. according to the battery of claim 10, wherein
Negative active core-shell material further comprises iron.
19. according to the battery of claim 10, wherein
Electrolyte comprises the derivative of the cyclic carbonate of halogen atom.
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