CN100421286C - Non-aqueous electrolyte secondary battery - Google Patents
Non-aqueous electrolyte secondary battery Download PDFInfo
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- CN100421286C CN100421286C CNB2005101285502A CN200510128550A CN100421286C CN 100421286 C CN100421286 C CN 100421286C CN B2005101285502 A CNB2005101285502 A CN B2005101285502A CN 200510128550 A CN200510128550 A CN 200510128550A CN 100421286 C CN100421286 C CN 100421286C
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Abstract
Disclosed is a non-aqueous electrolyte secondary battery having an electrode group in which a positive electrode and a negative electrode are spirally wound with a separator interposed therebetween. The positive electrode contains a positive electrode active material and a binder. The positive electrode active material contains a mixture of two different particulate substances having different average particle sizes. The two different particulate substances are lithium composite metal oxides containing nickel as an essential element. The binder includes fluorocarbon resin and rubber particles. The fluorocarbon resin contains at least a vinylidene fluoride unit. The amount of the rubber particles per 100 parts by weight of the fluorocarbon resin is 1 to 25 parts by weight.
Description
Technical field
The present invention relates to the rechargeable nonaqueous electrolytic battery of high power capacity, relate in particular to anodal flexible improvement.
Background technology
Recent years, along with littler and lighter weight electronic equipment, popularizing of cell phone and notebook computer for example increases the demand as its power supply of high-capacity secondary battery more.So far, developed and had the lithium and cobalt oxides of comprising (LiCoO for example
2) as the positive pole of positive electrode active materials, and the rechargeable nonaqueous electrolytic battery that comprises cathode of carbon material, and use widely now.
But, because contain Co, LiCoO
2Be very expensive.For this reason, advised that various metal oxides are as LiCoO
2Sub, and in depth studied.The example of these metal oxides comprises: comprise the lithium complex metal oxide (hereinafter sometimes be called contain ni compound oxide) of nickel as essential elements, for example LiNiO
2With by partly replacing LiNiO with Co
2In Ni and the LiNi that obtains
1-xCo
xO
2, and LiMn
2O
4
Particularly comprise and contain ni compound oxide and can provide than those as the positive pole of active material and comprise lithium and cobalt oxides, therefore reduced the capacity of producing the cost of rechargeable nonaqueous electrolytic battery and having increased battery as the higher energy density of the positive pole of active material.
In the production of anode of secondary battery, go up the administration of material mixture paste at collector body (current collector) usually, then dry and curling, form the positive electrode mixture layer.Described material blends slurry prepares by adding positive electrode active materials in the liquid of dissolving in organic solvent or the acquisition of dispersion binding agent, stirring then and mix.Usually use polyvinylidene fluoride (hereinafter being called PVDF), polytetrafluoroethylene and ethylene-propylene diene copolymer as binding agent.Wherein, because it is difficult for being dissolved in the electrolyte and has superior electrolyte reserve capability, so the binder material that PVDF is best suited for.
Fluorocarbon resin with vinylidene fluoride units has low alkali resistance.Therefore, when described material blends pulp bales alkali metal containing salt, be accompanied by slurry and condense and have the problem that the material blends layer is solidified.
With LiCoO
2And LiNiO
2Be generally comprised within the alkali metal salt of introducing in the production process wherein for the lithium complex metal oxide of representing.It is difficult removing this alkali metal salt fully.LiNiO particularly
2The excessive alkali metal salt of synthetic needs, so alkali metal salt may be residual.
Residual alkali metal salt makes the material blends slurry condense easily, and helps coating (being the positive electrode mixture layer) to solidify.Think that the mechanism of this phenomenon is as follows.PVDF at first contacts with the lithium salts that comprises in the active material, causes PVDF dehydrogenation fluoric acid (HF) reaction, forms carbon-to-carbon double bond.Because described pair of key is very unsettled, so PVDF is intermolecular or the interior cross-linking reaction that takes place of molecule.Along with described reaction carrying out in time, slurry condenses or the material blends layer solidifies.If use the positive pole of the material blends layer that solidifies to produce the electrode group that spiral twines, during the spiral winding process in the material blends layer crackle is taking place, this can make anodal fracture.
In order to prevent that the positive electrode mixture layer from solidifying, advised partly replacing PVDF (preferable amount is 45 weight % or more) (for example consulting, Japan's special permission discloses 2000-21407 number) with the rubbery acrylic based copolymer.Used acrylic acid series copolymer is the copolymer that has added the butadiene-styrene rubber (SBR) of methyl methacrylate, itaconic acid or acrylonitrile unit for instance.In order to improve the pliability of positive plate, it is that 1: 3 to 3: 1 PVDF derivative and rubber grain are as binding agent that Japan's special permission discloses 2003-331825 suggestion operating weight ratio.
Summary of the invention
It is generally accepted that comprising nickel has low powder flowbility as the lithium complex metal oxide (containing ni compound oxide) of essential elements.Therefore, use this ni compound oxide that contains to trend towards having bad pliability as the positive pole of active material production.For this reason, need improve the powder flowbility of active material by the mixture that uses two kinds of differences with different average grain diameters to contain ni compound oxide.
Disclosed as open 2000-21407 of Japan's special permission and 2003-331825, the use rubber grain has improved the pliability of positive electrode mixture layer as binding agent and has stoped the curing of positive electrode mixture layer.But the material blends layer that comprises excessive rubber grain can separate from collector body at electrode group production period.
The inventor has been found that polar group is connected on the fluorocarbon resin when between the fluorocarbon resin molecule that comprises vinylidene fluoride units or intramolecular cross-linking reaction when carrying out, thereby the binding ability of fluorocarbon resin self becomes stronger than rubber grain.They are also found along with regulating rubber grain and the weight ratio that comprises the fluorocarbon resin of vinylidene fluoride units, the degree of cross linking in the fluorocarbon resin can be controlled in the suitable scope, and also can guarantee the satisfied positive electrode mixture layer and the adhesiveness of collector body simultaneously even at electrode group production period.
Based on above-mentioned discovery, realized that the present invention guarantees the anodal pliability and the adhesiveness of positive electrode mixture layer and collector body.In order to obtain the rechargeable nonaqueous electrolytic battery of high power capacity, positive electrode active materials comprises two kinds of different particulate materials with different average grain diameters.Each all comprises and contains the lithium complex metal oxide of nickel as essential elements in two kinds of different particulate materials.
More particularly, the present invention relates to a kind of rechargeable nonaqueous electrolytic battery, it comprises electrode group wherein anodal and that the negative pole spiral twines and be inserted with barrier film therebetween, described positive pole comprises positive electrode active materials and binding agent, described positive electrode active materials comprises the mixture of being made up of two kinds of different particulate materials with different average grain diameters, each all comprises described two kinds of different particulate materials and contains the lithium complex metal oxide of nickel as essential elements, described binding agent comprises fluorocarbon resin and rubber grain, and described fluorocarbon resin comprises vinylidene fluoride units at least, and the consumption of rubber grain is 1 to 25 weight portion in wherein per 100 weight portion fluorocarbon resins.
It is the particulate material B that 10 microns to 20 microns particulate material A and average grain diameter are 3 microns to 10 microns that the mixture of preferred two kinds of variable grain shape materials comprises average grain diameter, and the average grain diameter (D of particulate material A
A) with the average grain diameter (D of particulate material B
B) ratio D
A/ D
BBe 1.5 to 7.Particulate material A is preferably 50% to 80% with respect to the percetage by weight of the mixture of two kinds of variable grain shape materials.
The mixture of two kinds of variable grain shape materials can comprise the primary granule and the secondary granule of lithium complex metal oxide.For instance, can use the mixture of the particulate material B that comprises the particulate material A that forms by the secondary granule of lithium complex metal oxide and form by the primary granule of lithium complex metal oxide.
Preferably, described rubber grain is nuclear-shell (core-shell) rubber grain that comprises acrylonitrile unit.Nuclear-shell rubber grain preferably comprises acrylic ester unit in shell.The consumption of fluorocarbon resin is preferably 1 to 3 weight portion with respect to 100 weight portion positive electrode active materials.
According to the present invention, contain in the high power capacity rechargeable nonaqueous electrolytic battery of lithium complex metal oxide as positive electrode active materials of nickel as essential elements comprising, can guarantee the adhesiveness that positive electrode mixture layer and collector body are suitable.Simultaneously, solidify, can also guarantee the pliability that just is being thoroughly satisfied by stoping the positive electrode mixture layer.This just when thereby spiral twines positive pole and negative pole and insert barrier film production electrode group betwixt, has stoped the separation of positive electrode mixture layer.Thereby, can improve the quality and the productivity ratio of high power capacity rechargeable nonaqueous electrolytic battery.
When the novel feature of the present invention of proposition particularly in additional claim, from following detailed description, will better understand and understand tissue of the present invention and content in conjunction with the accompanying drawings, and other purpose and feature.
Description of drawings
Fig. 1 is expression particulate material A with respect to the percetage by weight of the mixture of particulate material A and the B figure to the density of the mixture of filling in the anodal material blends layer.
Fig. 2 is that the density that is illustrated in the container with given volume the mixture of particulate material A and B when filling described mixture realizes the figure of the pressure of described density to imposing on mixture.
Embodiment
Rechargeable nonaqueous electrolytic battery of the present invention has electrode group wherein anodal and that the negative pole spiral twines and be inserted with barrier film therebetween.The electrode group is installed in the battery case with reservation shape and nonaqueous electrolyte.The shape of battery case is not specifically limited.Usually, battery case is cylindrical or prismatic.At battery case is in the columniform situation, and the electrode group is a cylindrical shape.In battery case is prismatic situation, form the electrode group, make its cross section partly be similar to ellipse.
Positive pole comprises the positive electrode collector of positive electrode mixture layer and carrying positive electrode mixture layer.Positive electrode collector is a belt metal foil, preferably aluminium foil.The positive electrode mixture layer is carried on each surface of positive electrode collector.Be to be understood that positive electrode collector has lead-in wire coupling part or collected current part, and on described lead-in wire coupling part or collected current part, do not form the positive electrode mixture layer, thereby expose collector body.In order to realize littler and lighter weight battery, the typical thickness of collector body is 10 microns to 25 microns.The positive electrode mixture layer comprises positive electrode active materials and binding agent.The positive electrode mixture layer can further comprise other component beyond positive electrode active materials and the binding agent, for example electric conducting material.
Positive electrode active materials comprises two kinds of different particulate materials with different average grain diameters.Whether positive electrode active materials comprises two kinds of different particulate materials with different average grain diameters can be waited by electron microscope and confirm.In addition, can accurately discern two kinds of different particulate materials by the particle size distribution of measuring positive electrode active materials with different average grain diameters.In the particle size distribution of the mixture of two kinds of variable grain shape materials, observe two peaks usually.By analyzing the waveform in the particle size distribution respectively, can obtain the distribution of every kind of particulate material.
Two kinds of particulate materials all comprise for every kind and contain the lithium complex metal oxide of nickel as essential elements.Contain nickel and have bad powder flowbility as the lithium complex metal oxide of essential elements.But, can improve the powder flowbility of positive electrode active materials by mixing two kinds of different particulate materials with different average grain diameters.This has just reduced the distortion in the positive pole, and during spiral twines positive pole and negative pole and inserts the process of barrier film electrogenesis in next life utmost point group betwixt, has stoped anodal fracture.Positive electrode active materials can further comprise a spot of other particulate material.In the case, described amount of substance is preferably less than 10 weight % of active material total amount.
Binding agent comprises fluorocarbon resin and rubber grain.Fluorocarbon resin comprises vinylidene fluoride units at least.If binding agent only comprises the fluorocarbon resin that has vinylidene fluoride units at least, the positive electrode mixture layer will solidify, thereby has reduced the pliability of gained positive pole.Therefore, will rupture easily at electrode group production period positive pole.On the contrary, if binding agent comprises a large amount of rubber grains, thereby stop the positive electrode mixture layer to solidify, the adhesiveness of positive electrode mixture layer and collector body will reduce.Especially, in the positive electrode mixture layer inside of collector body outside carrying, the distance between the active material particle increases in the electrode group that spiral twines.Therefore, by using the binding agent of mainly forming to guarantee that adhesiveness is difficult by rubber grain.
In order to control the degree of cross linking in the fluorocarbon resin in suitable scope, and be implemented in the pliability that is enough to stand the spiral winding process and and the adhesiveness of collector body between have well balanced positive electrode mixture layer, should regulate the percentage by weight of fluorocarbon resin and rubber grain.When the percentage by weight of suitable adjusting fluorocarbon resin and rubber grain, can suitably carry out the crosslinked of fluorocarbon resin, polar group is connected on the fluorocarbon resin during this period.Thereby even in the electrode group that spiral twines, the distance in the positive electrode mixture layer of collector body outside carrying between the active material particle increases, and also can guarantee the abundant adhesiveness of positive electrode mixture layer and collector body.
More particularly, the percentage by weight of rubber grain and fluorocarbon resin should be 1% to 25%, preferred 5% to 20%.In other words, per 100 weight portion fluorocarbon resins need use 1 to 25 weight portion, preferred 5 to 20 parts by weight of rubber particles.If the percetage by weight of rubber grain surpasses 25%, the percentage of fluorocarbon resin will be too little. be not enough to be convenient to the crosslinked of fluorocarbon resin.As a result, can not guarantee the adhesiveness of positive electrode mixture layer and collector body at electrode group production period.On the contrary, if the percetage by weight of rubber grain is lower than 1%, the percentage of fluorocarbon resin will be too big, too promote the crosslinked of fluorocarbon resin.As a result, the positive electrode mixture layer solidifies, and with the same in traditional technology, is difficult to stop anodal fracture during the spiral winding process.
It is the particulate material B that 10 microns to 20 microns particulate material A and average grain diameter are 3 microns to 10 microns that the mixture of two kinds of variable grain shape materials preferably comprises average grain diameter, and more preferably average grain diameter is the particulate material B that 10 microns to 12 microns particulate material A and average grain diameter are 5 microns to 8 microns.In the case, the average grain diameter (D of particulate material A
A) with the average grain diameter (D of particulate material B
B) ratio D
A/ D
BBe preferably 1.5 to 7, more preferably 2 to 4.Regulate D
A/ D
BThan being 1.5 to 7 to guarantee easily particulate material A and B high filling rate (highly-filled state) in the positive electrode mixture layer, thereby also guaranteed the pliability of positive electrode mixture layer.Therefore, even spiral twines anodally under high curvature, also can protect near the positive pole that is positioned at the electrode group core not rupture.
Work as D
A/ D
BThan being 1.5 to 7 and the average grain diameter D of particulate material A
AWhen being not less than 10 microns, can stop the grain spacing of particulate material A too little.This has just stoped the reduction of particulate material A and the B filling rate (fill factor, curve factor) in the positive electrode mixture layer, thereby guarantees anodal pliability easily.Average grain diameter D as particulate material A
AWhen being not more than 20 microns, can stop the long-pending reduction of surface of active material, thereby stop the reduction of discharge capacity of the cell.
In addition, as the average grain diameter D of particulate material B
BWhen being not less than 3 microns, can stop surface of active material long-pending excessive.This has just stoped the fusible reduction of material blends layer that causes in default of binding agent.Work as D
A/ D
BThan being 1.5 to 7 and the average grain diameter D of particulate material B
BWhen being not more than 10 microns, can easily guarantee the powder flowbility and the anodal pliability of active material.
Particulate material A is preferably 50 to 80% with respect to the percetage by weight of particulate material A and B total amount, and more preferably 75% to 80%.When the percetage by weight of particulate material A is not less than 50% and when being not more than 80%, can increase the filling rate of particulate material A and B in the positive electrode mixture layer.This has just protected and has been positioned near the positive pole of electrode group core, makes and does not also rupture when spiral twines positive pole under higher curvature.
Fig. 1 is the percetage by weight (W of expression particulate material A with respect to particulate material A and B total amount
A) to the figure of the density of the mixture of filling in the anodal material blends layer.In the figure, suppose that individual particle is rigidity and sphere, and do not consider friction effect.In addition, suppose that particle is filled in the positive electrode mixture layer with the arrangement mode of remaining space minimum.Particulate material A has 12 microns average grain diameter.Particulate material B has 5 microns average grain diameter.
From Fig. 1 obviously as seen, when the percetage by weight of particulate material A is 50% to 80% with respect to the mixture of particulate material A and B, the density maximum of the active material of filling.The density of the active material of filling is relevant with the powder flowbility (being the mixture of particulate material A and B) of active material.In other words, when the percetage by weight of particulate material A was 50% to 80% with respect to the mixture of particulate material A and B, the powder flowbility of positive electrode active materials was the highest.
Fig. 2 is that the density that is illustrated in the container with given volume the mixture of particulate material A and B when filling described mixture realizes the figure of the pressure of described density to imposing on mixture.Realize specific density and applied pressure is low more, the powder flowbility of the mixture of particulate material A and B is high more.The every corresponding percent value of line is represented the percetage by weight of particulate material A with respect to the mixture of particulate material A and B among attention and the figure.In addition, in the figure, the average grain diameter of particulate material A is 12 microns.The average grain diameter of particulate material B is 5 microns.
From Fig. 2 obviously as seen, applied pressure is little because realize specific density, has high powder flowbility so the percetage by weight of particulate material A is 50% and 75% mixture.
The mixture of two kinds of variable grain shape materials can be the primary granule of lithium complex metal oxide and the mixture of secondary granule.For instance, positive electrode active materials can be the agglomerated particle that will pulverize in the back during various production processes.Agglomerated particle becomes the primary granule in the positive electrode mixture layer and the mixture of secondary granule in the positive pole of producing.In the case, can avoid controlling the complexity of multiple variable grain shape material.
To comprise nickel as the lithium complex metal oxide of essential elements usually by synthesizing being not less than the raw material that roasting under 900 ℃ the high temperature comprises the ball-shape nickel hydroxide powder basically.If by the roasting raw material obtain agglomerated particle under 900 ℃ the high temperature being not less than, then slowly cooling, the adhesion between primary granule will be high.Therefore, the agglomerated particle that so obtains can not be pulverized by external stress.These agglomerated particles have low powder flowbility.
On the contrary, if after roasting fast cooling synthetic according to the method described above comprise the lithium complex metal oxide of nickel, the suitable agglomerated particle of degree ground pulverizing gained during the preparation of positive electrode mixture paste and subsequent process as essential elements.In this case, the optimal seeking of raw and processed materials is that average grain diameter is 3 microns to 30 microns, more preferably 5 microns to 15 microns nickel hydroxide.If use this lithium complex metal oxide as positive electrode active materials, in the positive electrode mixture layer of gained, mix two kinds of variable grain shape materials, form primary granule and secondary granule and mixture as positive electrode active materials with different average grain diameters.
Comprising nickel is not specifically limited as the lithium complex metal oxide of essential elements.LiNiO preferably
2And Li (Ni-M) O
2" (Ni-M) " expression of herein using partly replaces Ni with element M.At Li (Ni-M) O
2Situation under, element M preferably is that a kind of being selected from by Co, Mn, Al and Mg formed element in the group at least.Wherein, particularly preferably be Li (Ni-Co) O
2, Li (Ni-Co-Mg) O
2, Li (Ni-Mn) O
2And Li (Ni-Mn-Co) O
2They can use separately or use with two or more combination in any.
Comprise when being not less than the Ni of 70 atom % with respect to the metallic element total amount beyond the Li when comprising the lithium complex metal oxide of nickel as essential elements, the present invention is effective especially.
As for binding agent, the fluorocarbon resin that comprises vinylidene fluoride units at least is not specifically limited.Can use polyvinylidene fluoride (PVDF), the copolymer of the modified form of PVDF and vinylidene fluoride and other monomer.They can use separately or use with two or more combination in any.Being used for other monomer that the monomer or be used for of modification PVDF forms copolymer can be a chlorotrifluoroethylene, hexafluoropropylene or maleic acid.The amount of the vinylidene fluoride units that comprises in the fluorocarbon resin preferably is not less than 70 weight %, more preferably is not less than 90 weight %.
Rubber grain is not particularly limited.Preferred examples comprises modified form and the nuclear-shell rubber grain (for example SBR modified form of nuclear-hull shape formula) of Styrene-Butadiene (SBR), SBR.They can use separately or use with two or more combination in any.Particularly preferably be the nuclear-shell rubber grain that comprises acrylonitrile unit.For instance, the bound acrylonitrile unit has increased the hardness of nuclear in nuclear, and this is favourable for keeping coating of particles.In addition, by in shell, introducing the unit that comprises polar group, can give high binding ability of rubber grain and resilience.Or even a spot of this core shell rubber particles just is enough to the binding ability that provides high.The stability of consideration under positive electrode potential, preferred especially described shell comprises acrylic ester unit.
The example of commercially available nuclear-shell rubber grain comprises: BM-400B (trade (brand) name) comprises the styrene units that is combined in the shell; And BM-500B (trade (brand) name) comprises the acrylic ester unit that is combined in the shell, and both all can obtain from ZEON CORPORATION.
The average grain diameter of rubber grain is preferred, but is not limited to 0.05 micron to 0.5 micron.When described average grain diameter was not less than 0.05 micron, the surface of active material particle can too not applied by rubber grain, thereby cell reaction is steadily carried out.When average grain diameter was not more than 0.5 micron, the distance between active material can be not wide, thereby allow the easy electronic conductivity that guarantees in the positive pole.
The amount of the fluorocarbon resin that comprises in the positive electrode mixture layer is preferably 1 to 3 weight portion in per 100 weight portion positive electrode active materials.As mentioned above, unless carry out suitably crosslinkedly, otherwise fluorocarbon resin can not show its binding ability fully.But when too carrying out, fluorocarbon resin causes the curing of material blends layer when crosslinked.For this reason, suitable crosslinked in order to allow to carry out, the amount of the fluorocarbon resin that the positive electrode mixture layer comprises is preferably 1 to 3 weight portion in per 100 weight portion positive electrode active materials.
Anode active material layer can further comprise electric conducting material.Electric conducting material is not specifically limited.Preferred electric conducting material is a carbon black.The example of carbon black comprises acetylene black, furnace black and Kai Jinhei (ketjen black).They can use separately or use with two or more combination in any.Wherein, acetylene black and furnace black are preferred.To the average grain diameter of electric conducting material without limits.The average grain diameter of preferred primary granule is 0.01 micron to 0.1 micron.
The method of production rechargeable nonaqueous electrolytic battery of the present invention is described now.
(i) first step (preparation of positive electrode mixture paste)
Preparation comprises the positive electrode mixture paste of positive electrode active materials, binding agent (being fluorocarbon resin and rubber grain), electric conducting material and decentralized medium.Decentralized medium is N-methyl-2-pyridine alkane ketone (NMP) preferably, but it also can be the ketone of acetone for example.Under the situation of using ketone, ketone preferably mixes with NMP.
The amount of the electric conducting material that comprises in the positive electrode mixture paste is preferably per 100 weight portion positive electrode active materials, 1 to 3 weight portion.When the amount of electric conducting material is not less than 1 weight portion, stoped the reduction of positive electrical electron conductivity, the cycle life that has prolonged battery.On the contrary, when the amount of electric conducting material is not more than 3 weight portions, stoped the reduction of battery capacity.
(ii) second step (anodal production)
The positive electrode mixture paste is administered on two surfaces of the collector body that is used as anodal core components, dry then and curling, form the positive electrode mixture layer.The positive plate of so producing is cut into predetermined size, produces positive pole.The gross thickness of the positive electrode mixture layer that carries on two surfaces of collector body and collector body is generally 80 to 200 microns.
(iii) the 3rd step (production of negative pole)
The production method of anticathode is not specifically limited.Can produce negative pole by conventional method.For instance, at first preparation comprises and can absorb and the material with carbon element of desorb lithium ion and the negative material mixture paste of binding agent.Then, the negative material mixture paste is administered on two surfaces as the collector body of negative pole core components, dry then and curl, form the negative material mixture layer.The negative plate of so producing is cut into predetermined size, produces negative pole.The gross thickness of the negative material mixture layer that carries on two surfaces of collector body and collector body is generally 80 to 200 microns.
Except above-mentioned SBR and nuclear-shell rubber grain, can use the polyacrylic acid fine particle as the binding agent that will add in the negative material mixture.In order to give the negative material mixture paste better viscosity, can in slurry, add carboxymethyl cellulose (CMC) or polyethylene glycol oxide.The amount of the binding agent that comprises in the negative material mixture is preferably per 100 weight portion material with carbon elements, 1.5 to 4 weight portions.Negative electrode collector is the metal forming of Copper Foil for example.In order to realize littler and lighter weight battery, the thickness of negative electrode collector is generally 8 to 20 microns.
(iv) the 4th step (battery assembling)
Use described positive pole, negative pole and nonaqueous electrolyte assemble.At first, twine positive pole and negative pole and insert barrier film electrogenesis in next life utmost point group betwixt by spiral.During described winding process, cylindrical if both positive and negative polarity and barrier film are wound in by spiral, can obtain to be used for the electrode group of cylindrical battery.If spiral twines both positive and negative polarity and barrier film makes its cross section be similar to ellipse, can obtain to be used for the electrode group of prismatic battery.The electrode group of gained is installed in the battery case with reservation shape.In the battery case of hold electrodes group, inject nonaqueous electrolyte.Then, the sealed cell shell is produced rechargeable nonaqueous electrolytic battery.
The microporous barrier that barrier film is preferably made by for example polyethylene or polyacrylic polyolefin.The thickness of barrier film is generally 10 microns to 40 microns.
Nonaqueous electrolyte is not specifically limited, and can uses any traditional electrolyte that is used for rechargeable nonaqueous electrolytic battery.Typically, the preferred electrolyte for preparing by dissolving lithium salts in nonaqueous solvents that uses.The example of lithium salts comprises LiPF
6And LiBF
4They can use separately or make up with two or more and use.
Examples of non-aqueous comprises ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC) and methyl ethyl carbonate (EMC).They can use separately or use with two or more combination in any.
Nonaqueous electrolyte can further comprise the additive that strengthens anti-overloading performance.The additive preferred examples is the benzene derivative with phenyl and cyclic compound group adjacent with phenyl.The example of benzene derivative comprises biphenyl, cyclohexyl benzene, biphenyl ether and benzene lactone.
Hereinafter, illustrate in greater detail the present invention with reference to embodiment.But, be to be understood that the present invention is not limited thereto.
The term of Shi Yonging " average grain diameter " means the average grain diameter (D based on volume in this manual
50).
Test 1
For the situation of in the positive electrode active materials preparation, using two kinds of variable grain shape materials, test with different average grain diameters.
Embodiment 1
(i) Zheng Ji production
Use comprises the raw material of the solid solution nickel hydroxide of a certain amount of cobalt and aluminium as positive electrode active materials.More particularly, the mixing average grain diameter is 7 microns solid solution nickel hydroxide (nickel hydroxide A) and a lithium hydroxide, then 950 ℃ of following roastings.Slowly the cooling products therefrom is 12 hours to 100 ℃.Thereby obtaining the lithium nickel composite oxide secondary granule (forms: LiNi
0.8Co
0.15Al
0.05O
2), be called particulate material A.Simultaneously, be 0.3 micron the solid solution nickel hydroxide (nickel hydroxide B) except using average grain diameter, prepare particulate material B according to the method identical with producing particulate material A.
The weight ratio A of particulate material A and B: B=70: 30.The average grain diameter of particulate material A is 20 microns.The average grain diameter of particulate material B is 1 micron.
According to foregoing first step, in 100 weight portion positive electrode active materials, add 2 weight portion PVDF and 0.2 weight portion comprises acrylonitrile unit and in shell in conjunction with the nuclear-shell rubber grain of acrylate as binding agent.In addition, in 100 weight portion active materials, add the average primary particle diameter of 2 weight portions be 0.03 micron acetylene black as the NMP of electric conducting material and appropriate amount as decentralized medium.Thereby prepare the positive electrode mixture paste.
The PVDF of Shi Yonging is available from Kureha Chemical Industry Co. herein, the solid contents of the KF polymer L#7208 (trade (brand) name) of Ltd..
Use herein comprise acrylonitrile unit and in shell the nuclear-shell rubber grain in conjunction with acrylate be solid contents available from the BM-500B of ZEON CORPORATION (trade (brand) name).
The positive electrode mixture paste is administered on two surfaces of aluminium foil (collector body) of 15 micron thickness, then dry and curl, form the positive electrode mixture layer.The positive plate of so producing is cut into is of a size of 56 mm wides and 610 millimeters long (56 millimeters * 610 millimeters).Thereby produce positive pole.Described just having a vesicularity of 20%.Aluminium foil is 154 microns with the gross thickness that is carried on two lip-deep positive electrode mixture layers of aluminium foil.
The (ii) production of negative pole
Add in 100 weight portion spherical natural graphite powder that 1 weight portion comprises acrylonitrile unit and in shell in conjunction with cinnamic nuclear-shell rubber grain as binding agent and 1 weight portion carboxymethyl cellulose (CMC) and an amount of water, then mix preparation negative material mixture paste.
Use herein comprise acrylonitrile unit and in shell the nuclear-shell rubber grain in conjunction with acrylate be solid contents available from the BM-500B of ZEON CORPORATION (trade (brand) name).
The negative material mixture paste is administered on two surfaces of Copper Foil (collector body) of 10 micron thickness, dry then and curl, form the negative material mixture layer.The negative plate of so producing is cut into is of a size of 58 mm wides and 640 millimeters long (58 millimeters * 640 millimeters).Thereby produce negative pole.Negative pole has 33% vesicularity.Copper Foil is 200 microns with the gross thickness that is carried on two lip-deep negative material mixture layers of Copper Foil.
The (iii) assembling of battery
The positive pole of producing was above left standstill one day.Then, the use external diameter is 3 millimeters a winding nuclear, the both positive and negative polarity spiral of producing above is wound in the cylinder, and inserts the polypropylene diaphragm of 20 micron thickness betwixt, produces the electrode group.The electrode group is installed in the band cylinder at the end, then to wherein injecting nonaqueous electrolyte.The nonaqueous electrolyte of Shi Yonging is by comprising that volume ratio is that concentration of ordinary dissolution is the LiPF of 1 mol in 2: 2: 6 the nonaqueous electrolyte mixture of ethylene carbonate (EC), carbonic acid two or four esters (DMC) and methyl ethyl carbonate (EMC) herein
6Prepare.
Then, the cylinder at the bottom of the band, thus to produce external diameter be 18 millimeters and highly be 65 millimeters cylindrical lithium ion secondary battery (rated capacity: 2500mAh).Described battery is called as the battery of embodiment 1.
Embodiment 2 to 4
Except by the average grain diameter of solid solution nickel hydroxide B is changed into 1 micron, 1.5 microns and 3 microns respectively, thereby the average grain diameter of particulate material B is varied to respectively outside 3 microns, 5 microns and 10 microns, according to embodiment 1 in identical method production example 2,3 and 4 battery.
Embodiment 5 to 7
Except by the average grain diameter of solid solution nickel hydroxide A is changed into 3 microns, thereby the average grain diameter of particulate material A changes 10 microns, and by the average grain diameter of solid solution nickel hydroxide B is changed into 1 micron, 1.5 microns and 2.5 microns respectively, thereby the average grain diameter of particulate material B is varied to respectively outside 3 microns, 5 microns and 8 microns, according to embodiment 1 in identical method production example 5,6 and 7 battery.
Embodiment 8 and 9
Except by the average grain diameter of solid solution nickel hydroxide B is changed into 1.5 microns, thereby the average grain diameter of particulate material B is changed to outside 5 microns, and respectively the weight ratio of particulate material A and B is changed into A: B=50: 50 and 80: 20, according to embodiment 1 in identical method production example 8 and 9 battery.
Embodiment 10 and 11
Except by the average grain diameter of solid solution nickel hydroxide B is changed into 1.5 microns, thereby the average grain diameter of particulate material B is changed to outside 5 microns, and respectively the weight ratio of particulate material A and B is changed into A: B=40: 60 and 85: 15, according to embodiment 1 in identical method production example 10 and 11 battery.
Embodiment 12
Except using BM-400B rubber grain (comprise acrylonitrile unit and in shell in conjunction with styrene units) to replace the BM-500B rubber grain, as anodal binding agent, and by the average grain diameter of solid solution nickel hydroxide B is changed into 1.5 microns, thereby the average grain diameter of particulate material B is changed to outside 5 microns, according to embodiment 1 in the battery of identical method production example 12.
Embodiment 13
Can replace the BM-500B rubber grain with the butadiene-styrene rubber (SBR) that trade (brand) name GRADE 0561 obtains from JSR company except using, as anodal binding agent, and by the average grain diameter of solid solution nickel hydroxide B is changed into 1.5 microns, thereby the average grain diameter of particulate material B is changed to outside 5 microns, according to embodiment 1 in the battery of identical method production example 13.
Embodiment 14 to 17
Except by the average grain diameter of solid solution nickel hydroxide B is changed into 1.5 microns, thereby the average grain diameter of particulate material B is changed to 5 microns, and the amount of PVDF is changed into respectively outside 0.8,1,3 and 4 weight portions in per 100 weight portion positive electrode active materials, according to embodiment 1 in identical method production example 14,15,16 and 17 battery.
Embodiment 18
Except by the average grain diameter of solid solution nickel hydroxide B is changed into 1.5 microns, thereby the average grain diameter of particulate material B is changed to 5 microns, and the amount (solids content of BM-500B) that is used as the rubber grain of anodal binding agent in per 100 weight portion positive electrode active materials is changed into outside 0.02 weight portion, according to embodiment 1 in the battery of identical method production example 18.
Comparing embodiment 1
Except only using particulate material A (promptly not using particulate material B), according to embodiment 1 in the battery of identical method production comparing embodiment 1.
Comparing embodiment 2
Except by the average grain diameter of solid solution nickel hydroxide B is changed into 1.5 microns, thereby the average grain diameter of particulate material B is changed to 5 microns, and the amount (solids content of BM-500B) that is used as the rubber grain of anodal binding agent in per 100 weight portion positive electrode active materials is changed into outside 0.6 weight portion, according to embodiment 1 in the battery of identical method production comparing embodiment 2.
Comparing embodiment 3
Except by the average grain diameter of solid solution nickel hydroxide B is changed into 1.5 microns, thereby the average grain diameter of particulate material B is changed to 5 microns, and the amount (solids content of BM-500B) that is used as the rubber grain of anodal binding agent in per 100 weight portion positive electrode active materials is changed into outside 0.01 weight portion, according to embodiment 1 in the battery of identical method production comparing embodiment 2.
Subsequently, by removing positive electrode collector, then washing obtains positive electrode active materials in every kind of electrode producing from embodiment 1 to 18 and comparing embodiment 2 and 3.Analyze the particle size distribution of gained positive electrode active materials by laser light scattering particle size distribution analyzer.As a result, observe the distribution of particulate material A and B.
Because raw material, promptly nickel hydroxide A and nickel hydroxide B are made up of the particle of almost spherical, so hypothesis nickel hydroxide A and nickel hydroxide B are perfect ball basically.Under described hypothesis, draw the percetage by weight W of particulate material A with respect to particulate material A and B total amount
AFor: W
A(%)={ A
3/ (A
3+ B
3) * 100 α.Herein, particulate material A counts α with the amounts of particles ratio of particulate material B: (1-α), and the average grain diameter of particulate material A and B is counted A and B.
In each embodiment, use the particle size distribution of gained and the percetage by weight W that above-mentioned formula is determined particulate material A
AAs a result, with respect to the percetage by weight of particulate material A in the starting mixt of particulate material A and B, the error range of the percetage by weight of every kind of positive pole only is ± 2.
[evaluation]
Test below every kind of battery of embodiment 1 to 18 and comparison 2 and 3 is accepted.
(peel strength of anode active material layer)
Bring the acquisition sample by the bar that positive pole is cut into wide 10 millimeters and long 80 millimeters.Alongst release liner mixture layer from the collector body of sample is peeled off required load by the measurement of peeling force testing machine during this period, and the result is illustrated in the table 1.
(defective of spiral winding process)
Before insertion has the cylinder of bottom,, search any crackle in the positive pole to being that 3 millimeters winding core spiral twines the electrode group that is obtained and carries out visual inspection by using external diameter.After each embodiment has been observed 20 electrode groups, add up the quantity of defective electrode group.The result is illustrated in the table 1.
(the interior pressure after the storage)
Use determines not have electrode group electrogenesis in the next life pond of defective in above-mentioned test.Activation below the battery of being produced is accepted in 20 ℃ environment.
(i) charging (in 20 ℃ environment) before the activation
Constant current charge: 1750mA
Charging end voltage: 4.0V.
(ii) activation
In 60 ℃ environment, kept two days.
(iii) activation back discharge (in 20 ℃ environment)
Constant-current discharge: 2500mA
Discharge end voltage: 2.5V.
Precharge/discharge below in 20 ℃ environment, carrying out subsequently.
(i) precharge
Constant current charge: 1750mA
Charging end voltage: 4.2V
Constant-current discharge: 2500mA
Discharge end voltage: 2.5V
Carry out following storage test subsequently.
(i) store preceding charging
Constant current charge: 1750mA
Charging end voltage: 4.2V.
(ii) store
In 85 ℃ environment, store three days.
(iii) internal pressure measurement
Battery after the storage naturally cools to 20 ℃, collects the gas in the battery then.Residual volume from the gas flow collected and battery is pressed in the counting cell.The result is illustrated in the table 1.
The result as mentioned above.
In the comparing embodiment 1 of only using particulate material A as positive electrode active materials, observe defective electrode group takes place during the spiral winding process.This can make description below.Because the active material of comparing embodiment 1 is bad aspect powder flowbility, so can not obtain enough anodal pliabilities.Therefore, be distorted in material blends layer inside, this just causes the crackle that makes anodal fracture.
Obviously as seen, in the comparing embodiment 2 of rubber grain as binding agent that comprises a large amount of (promptly the amount with respect to PVDF is 30 weight %), the peel strength of material blends layer is extremely low from table 1.Infer that this is that the quantitative change of PVDF gets too little, and can not carry out the crosslinked of PVDF fully because because rubber grain excessive.On the contrary, in the comparing embodiment 3 of rubber grain as binding agent that comprises very a small amount of (promptly the amount with respect to PVDF is 0.5 weight %), the probability of defective electrode group is very high during the spiral winding process.Infer that this is because the crosslinked of PVDF excessively carries out, so the material blends layer can not obtain enough pliabilities.
Opposite with comparing embodiment 1 to 3, using by suitable weight ratio two kinds to have among the embodiment 2 to 6,8,9 and 12 of the variable grain shape material of different average grain diameters and the active material that an amount of rubber grain is formed, in positive pole, do not observe fracture.In other words, during the spiral winding process, do not cause fracture.In addition, peel strength is high.The positive electrode mixture layer of these embodiment has satisfied active material filling rate and superior powder flowbility.For this reason, even in the zone of the positive pole that the spiral with higher curvature twines, particle moves easily and the pliability of material blends layer is high, to such an extent as to positive pole can not rupture.In addition, because between the PVDF molecule, there is the rubber grain of appropriate amount, so that PVDF carries out is suitable crosslinked.Therefore, can reach a conclusion: of the present invention just having can bear enough pliabilities that spiral twines and the enough material blends layer and the adhesiveness of collector body.
From table 1 obviously as seen, at the ratio D of the average grain diameter of the average grain diameter of particulate material A and particulate material B
A/ D
BAmong the embodiment 7 less than 1.5 and D
A/ D
BSurpass among 7 the embodiment 1, can not stop anodal fully in the fracture together of spiral winding process phase.Infer that this is because the filling rate of particulate material A and B reduces, and in the positive pole zone that the spiral with higher curvature twines, particle is not easy to move, to such an extent as to the pliability deficiency of material blends layer.Therefore draw preferred D
A/ D
BThan the conclusion that is 1.5 to 7.
In the embodiment 1 of average grain diameter less than 3 microns (specifically being 1 micron) that uses particulate material B, peel strength is lower slightly.Infer that this is because the surface area of active material is big, and the quantity not sufficient of PVDF.Therefore, can draw the preferred average grain diameter of particulate material B and be not less than 3 microns conclusion.
In total amount with respect to particulate material A and B, the percetage by weight W of particulate material A
AEmbodiment 10 less than 50%, and described percetage by weight W
ASurpass among 80% the embodiment 11, can not stop anodal fracture during the spiral winding process fully.Infer that this is because the filling rate of particulate material A and B reduces, and in the positive pole zone that the spiral with higher curvature twines, particle is not easy to move, to such an extent as to the pliability deficiency of material blends layer.Therefore draw the percetage by weight W of particulate material A
ABe preferably 50% to 80% conclusion.
In the percetage by weight with respect to the amount rubber grain of PVDF is 1% embodiment 18, can not stop anodal fracture during the spiral winding process fully.Infer that this is because because the amount of rubber grain is few, the crosslinked of PVDF carries out excessively a little.Therefore the percetage by weight that draws with respect to the amount rubber grain of the fluorocarbon resin that comprises vinylidene fluoride units is necessary for 1% to 25% conclusion.
As for the type of rubber grain, using the nuclear that the comprises acrylonitrile unit-shell rubber grain that for example uses in embodiment 3 and 12 is effective for the adhesiveness that improves between material blends layer and collector body.Infer that this is because because described nuclear-shell rubber grain has various polar groups in shell, so show high adhesiveness and elasticity.
The battery ratio that comprises the embodiment 3 of BM-500 (comprise acrylonitrile unit and in shell in conjunction with the nuclear-shell rubber grain of acrylate) comprises the embodiment 12 of BM-400B (comprise acrylonitrile unit and in shell in conjunction with the nuclear-shell rubber grain of styrene units), and the battery that perhaps comprises the embodiment 13 of SBR produces the gas of less amount after storage.This is because the shell of rubber grain is stable under the positive electrode potential of about 4.2V.This shows when using nuclear-shell rubber grain as binding agent, preferably comprises acrylic ester unit from the described shell of storage characteristics angle.
Among the embodiment 14 of amount of PVDF, crosslinked in per 100 weight portion active materials because PVDF does not suitably carry out less than 1 weight portion, so the adhesiveness of material blends layer and collector body is lower slightly.On the contrary, the amount of PVDF surpasses among the embodiment 17 of 3 weight portions in per 100 weight portion active materials, and the crosslinked acceleration of PVDF has promoted the curing of material blends layer.Therefore, although probability is little, anodal fracture takes place during the spiral winding process.Therefore, the amount that can draw PVDF in per 100 weight portion active materials is preferably the conclusion of 1 to 3 weight portion.
Test 2
For pulverizing the situation that positive electrode active materials forms two kinds of variable grain shape materials with different average grain diameters, test at anodal production period.
Embodiment 19
(i) Zheng Ji production
Use comprises the raw material of the solid solution nickel hydroxide of a certain amount of cobalt and aluminium as positive electrode active materials.More particularly, the mixing average grain diameter is 4 microns solid solution nickel hydroxide and a lithium hydroxide, then 950 ℃ of following roastings.The cooling products therefrom is 30 minutes to 100 ℃ fast.Thereby obtain lithium nickel composite oxide secondary granule (average grain diameter: 12 microns, form: LiNi
0.8Co
0.15Al
0.05O
2).Described particle is as positive electrode active materials.
According to foregoing first step, in 100 weight portion positive electrode active materials, add 2 weight portion PVDF and 0.2 weight portion comprises acrylonitrile unit and in shell in conjunction with the nuclear-shell rubber grain of acrylate as binding agent.In addition, in 100 weight portion active materials, add the average primary particle diameter of 2 weight portions be 0.03 micron acetylene black as the NMP of electric conducting material and appropriate amount as decentralized medium.Thereby prepare the positive electrode mixture paste.
The PVDF of Shi Yonging is available from Kureha Chemical Industry Co. herein, the solid contents of the KF polymer L#7208 (trade (brand) name) of Ltd..
Use herein comprise acrylonitrile unit and in shell the nuclear-shell rubber grain in conjunction with acrylate be solid contents available from the BM-500B of ZEON CORPORATION (trade (brand) name).
The positive electrode mixture paste is administered on two surfaces of aluminium foil (collector body) of 15 micron thickness, then dry and curl, form the positive electrode mixture layer.The positive plate of so producing is cut into is of a size of 56 mm wides and 610 millimeters long (56 millimeters * 610 millimeters).Thereby produce positive pole.Just having 20% vesicularity.Aluminium foil is 154 microns with the gross thickness that is carried on two lip-deep positive electrode mixture layers of aluminium foil.
Subsequently, peel off the positive electrode mixture layer from the positive pole of being produced, then washing obtains positive electrode active materials.Analyze the particle size distribution of gained positive electrode active materials by laser light scattering particle size distribution analyzer.As a result, observe the particulate material A that forms by the lithium nickel composite oxide secondary granule and by during production process by pulverizing the distribution of the particulate material B that lithium nickel composite oxide primary granule that secondary granule produces forms.
According to the particle size distribution that obtains, determine the average grain diameter of particulate material A and particulate material B.The average grain diameter of particulate material A is 12 microns.The average grain diameter of particulate material B is 3 microns.Particulate material A is with respect to the percetage by weight W of particulate material A and B total amount
ABe 75%.At the supposition secondary granule is under the perfect spherical situation basically, uses particulate material A and the amounts of particles ratio of particulate material B and the average grain diameter of particulate material A and B, by the given formula (W in front
A(%)={ A
3/ (A
3+ B
3) * 100 α) calculated weight percentage W
A
The (ii) production of negative pole
According to embodiment 1 in identical mode produce negative pole.
The (iii) assembling of battery
According to embodiment 1 in ten thousand identical formula assemble.
The battery of gained is called as the battery of embodiment 19.
Embodiment 20 and 21
The amount that is used as the PVDF of anodal binding agent in per 100 weight portion positive electrode active materials is changed into respectively 1 and 3 weight portions, according to embodiment 19 in identical method production example 20 and 21 battery.
Embodiment 22 and 23
The amount that is used as the rubber grain (solids content of BM-500B) of anodal binding agent in per 100 weight portion positive electrode active materials is changed into respectively 0.02 and 0.5 weight portion (being percetage by weight 1% and 25% with respect to the PVDF amount), according to embodiment 19 in identical method production example 22 and 23 battery.
Embodiment 24
The rubber grain that replaces BM-500B except the rubber grain that uses BM-400B (comprise acrylonitrile unit and in shell in conjunction with the nuclear-shell rubber grain of styrene units), outside anodal binding agent, according to embodiment 19 in the battery of identical method production example 24.
Embodiment 25
Can replace the BM-500B rubber grain with the butadiene-styrene rubber (SBR) that trade (brand) name GRADE 0561 obtains from JSR company except using, outside anodal binding agent, according to embodiment 19 in the battery of identical method production example 25.
Embodiment 26
Except the amount of PVDF is changed into 0.8 weight portion in per 100 weight portion positive electrode active materials, and the amount of rubber grain (solids content of BM-500B) is changed into outside 0.1 weight portion in per 100 weight portion positive electrode active materials (is 12.5 weight % with respect to PVDF amount), according to embodiment 19 in the battery of identical method production example 26.
Embodiment 27
Except changing into as the amount of the PVDF of anodal binding agent in per 100 weight portion positive electrode active materials 4 weight portions, according to embodiment 19 in the battery of identical method production example 27.
Embodiment 28
Except the amount of rubber grain (solids content of BM-500B) is changed into 0.1 weight portion in per 100 weight portion positive electrode active materials (being percetage by weight 5% with respect to PVDF amount), according to embodiment 19 in the battery of identical method production example 28.
Comparing embodiment 4
Except in the production of positive electrode active materials, changed into 12 hours from 30 minutes the cooling time of lithium nickel composite oxide outside (promptly implement slowly cooling), according to embodiment 19 in the battery of identical method production comparing embodiment 4.
Comparing embodiment 5
Except only using PVDF (promptly not using rubber grain), according to embodiment 19 in the battery of identical method production comparing embodiment 5.
Comparing embodiment 6 and 7
Except the amount of rubber grain (solids content of BM-500B) is changed into 0.6 and 0.01 weight portion in per 100 weight portion positive electrode active materials (being percetage by weight 30% and 0.5% with respect to PVDF amount) respectively, according to embodiment 19 in identical method production example 6 and 7 battery.
Obtain positive electrode active materials by peeling off the positive electrode mixture layer in the positive pole of from embodiment 20 to 28 and comparing embodiment 5 to 7, producing, then washing.Analyze the particle size distribution of every kind of gained positive electrode active materials by laser light scattering particle size distribution analyzer.As a result, similar to embodiment 19, observe the particulate material A that forms by the lithium nickel composite oxide secondary granule and by during production process by pulverizing the distribution of the particulate material B that lithium nickel composite oxide primary granule that secondary granule produces forms.
According to the particle size distribution that obtains, determine the average grain diameter of particulate material A and particulate material B.Similar to embodiment 19, the average grain diameter of particulate material A is 12 microns.The average grain diameter of particulate material B is 3 microns.Particulate material A is with respect to the percetage by weight W of particulate material A and B total amount
ABe 75%.
In comparing embodiment 4, only observe the particle size distribution of secondary granule.The average grain diameter of described secondary granule is 12 microns.
[evaluation]
According to mode as hereinbefore, from the peel strength of positive electrode mixture layer, during the spiral winding process defective and store after the internal pressure aspect estimate the battery of embodiment 19 to 28 and comparing embodiment 4 to 7.The result is illustrated in the table 2.
The result as mentioned above.
Slowly cooling prepares in the comparing embodiment 4 of active material after roasting, and the occurrence probability of defective electrode group is very big during the spiral winding process.Reduced the distortion of positive electrode active materials inside by slow cooling, thereby even positive electrode active materials can be not broken yet when applying applied stress.Therefore, secondary granule keeps not crushed in the positive pole of being produced.Why the chances are because the bad powder flowbility of material blends layer for the reason of just as easy as rolling off a log fracture.Specifically, during the spiral winding process, particle is not easy to move in having the darkest zone of positive pole of higher curvature, and this just causes causing distortion in the material blends layer, cracks.
In the comparing embodiment of not using as the rubber grain of binding agent 5, the occurrence probability of defective electrode group is very high during the spiral winding process.Infer that this is because do not use rubber grain, does not suppress the curing of the crosslinked of PVDF and material blends layer and significantly carries out.
Opposite with comparing embodiment, cooling off active material fast and comprising in the embodiment of the invention of rubber grain as binding agent, the occurrence probability of defective electrode group is very little.Particularly in embodiment 19,20,23 to 26 and 28, occurrence probability is 0.Supposition is in the active material of the embodiment of the invention, because cooling fast, the distortion in the positive electrode active materials is big, to such an extent as to positive electrode active materials is crushed by applied stress easily.Therefore, mixed primary granule and secondary granule in the positive pole of being produced, formed mixture, this just makes particle even also moves easily in the zone of higher curvature, thereby gives material blends layer pliability.Therefore, positive pole can not rupture.In addition, because the intermolecular rubber grain that has appropriate amount of PVDF, suitably promoted the crosslinked of PVDF, to such an extent as to just having the enough positive electrode mixture layers and the adhesiveness of collector body, and have enough pliabilities for bearing the spiral winding process simultaneously.
Percetage by weight at rubber grain is that the adhesiveness of positive electrode mixture layer and collector body is low-down in the comparing embodiment 6 of 25 weight % with respect to PVDF.Infer that this is because excessive rubber grain has caused the crosslinked deficiency of PVDF.On the contrary, in the percetage by weight of rubber grain with respect to PVDF is comparing embodiment 7 below the 1 weight %, can not stop the occurrence probability of defective electrode during the spiral winding process.Infer that this is because because very few rubber grain can not suitably carry out the crosslinked of PVDF.The percetage by weight that therefore can draw rubber grain is necessary for 1% to 25% with respect to the amount of the fluorocarbon resin that comprises vinylidene fluoride units.
As for the type of rubber grain, compare with the embodiment 25 that uses SBR, use the nuclear that the comprises acrylonitrile unit-shell rubber grain that for example in embodiment 19 and 24, uses to improve the adhesiveness of material blends layer and collector body to a great extent.Infer that this is because because described nuclear-shell rubber grain has various polar groups in shell, so show high adhesiveness and elasticity.
The battery ratio that comprises the embodiment 19 of BM-500 (comprise acrylonitrile unit and in shell in conjunction with the nuclear-shell rubber grain of acrylic ester unit) comprises the embodiment 24 of BM-400B (comprise acrylonitrile unit and in shell in conjunction with the nuclear-shell rubber grain of styrene units), and the battery that perhaps comprises the embodiment 25 of SBR produces the gas of less amount after storage.This is because the shell of rubber grain is stable under the positive electrode potential of about 4.2V.This shows when using nuclear-shell rubber grain as binding agent, considers that from the storage characteristics angle described shell preferably comprises acrylic ester unit.
Among the embodiment 26 of amount of PVDF, crosslinked in per 100 weight portion active materials because PVDF does not suitably carry out less than 1 weight portion, so the adhesiveness of material blends layer and collector body is lower slightly.On the contrary, the amount of PVDF surpasses among the embodiment 27 of 3 weight portions in per 100 weight portion active materials, and the crosslinked acceleration of PVDF has promoted the curing of material blends layer.Therefore, although probability is little, anodal fracture takes place during the spiral winding process.Therefore, the amount that can draw PVDF in per 100 weight portion active materials is preferably the conclusion of 1 to 3 weight portion.
The present invention plans to improve and comprises and contain the productivity ratio of nickel as the high power capacity rechargeable nonaqueous electrolytic battery of the positive electrode active materials of the lithium complex metal oxide of essential elements.According to the present invention, the positive electrode active materials that comprises the mixture of forming by two kinds of variable grain shape materials with different average grain diameters by use, can give positive electrode mixture layer pliability, and give collector body and the suitable adhesiveness of positive electrode mixture layer simultaneously, to such an extent as to can reduce the occurrence probability of defective electrode group greatly.
Although the present invention has been described, be to be understood that described disclosed content is not restrictive with currently preferred embodiments.Various changes are tangible after having read above-mentioned disclosure for the relevant those skilled in the art of the present invention undoubtedly with individual character.Therefore, appended claim is interpreted as containing the institute that drops in true spirit of the present invention and the scope and changes and revise.
Claims (13)
1. rechargeable nonaqueous electrolytic battery, the electrode group that it comprises wherein anodal and negative pole spiral winding and is inserted with barrier film therebetween,
Described positive pole comprises positive electrode active materials and binding agent,
Described positive electrode active materials comprises the mixture of being made up of two kinds of different particulate materials with different average grain diameters,
It is the particulate material B that 10 microns to 20 microns particulate material A and average grain diameter are 3 microns to 10 microns that the described mixture of being made up of two kinds of variable grain shape materials comprises average grain diameter, and the average grain diameter D of wherein said particulate material A
AAverage grain diameter D with described particulate material B
BRatio D
A/ D
BBe 1.5 to 7,
Each all comprises the lithium complex metal oxide that contains nickel described two kinds of different particulate materials,
Described binding agent comprises fluorocarbon resin and rubber grain, and
Described fluorocarbon resin comprises vinylidene fluoride units at least,
The consumption of rubber grain is 1 to 25 weight portion described in the described fluorocarbon resin of wherein per 100 weight portions.
2. according to the rechargeable nonaqueous electrolytic battery of claim 1, wherein said particulate material A is 50% to 80% with respect to the percetage by weight of the described mixture of being made up of two kinds of variable grain shape materials.
3. according to the rechargeable nonaqueous electrolytic battery of claim 1, wherein said rubber grain is the nuclear-shell rubber grain that comprises acrylonitrile unit.
4. according to the rechargeable nonaqueous electrolytic battery of claim 1, wherein said nuclear-shell rubber grain comprises acrylic ester unit in shell.
5. according to the rechargeable nonaqueous electrolytic battery of claim 1, the consumption of wherein said fluorocarbon resin is 1 to 3 weight portion with respect to the described positive electrode active materials of 100 weight portions.
6. according to the rechargeable nonaqueous electrolytic battery of claim 1, the wherein said mixture of being made up of two kinds of variable grain shape materials is the primary granule of described lithium complex metal oxide and the mixture of secondary granule.
7. according to the rechargeable nonaqueous electrolytic battery of claim 5, wherein said particulate material A is 50% to 80% with respect to the percetage by weight of the described mixture of being made up of two kinds of variable grain shape materials.
8. according to the rechargeable nonaqueous electrolytic battery of claim 5, wherein said rubber grain is the nuclear-shell rubber grain that comprises acrylonitrile unit.
9. according to the rechargeable nonaqueous electrolytic battery of claim 5, wherein said nuclear-shell rubber grain comprises acrylic ester unit in shell.
10. according to the rechargeable nonaqueous electrolytic battery of claim 5, the wherein said mixture of being made up of two kinds of variable grain shape materials is the primary granule of described lithium complex metal oxide and the mixture of secondary granule.
11. according to the rechargeable nonaqueous electrolytic battery of claim 6, wherein said particulate material A is 50% to 80% with respect to the percetage by weight of the described mixture of being made up of two kinds of variable grain shape materials.
12. according to the rechargeable nonaqueous electrolytic battery of claim 6, wherein said rubber grain is the nuclear-shell rubber grain that comprises acrylonitrile unit.
13. according to the rechargeable nonaqueous electrolytic battery of claim 6, wherein said nuclear-shell rubber grain comprises acrylic ester unit in shell.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104981927A (en) * | 2013-05-23 | 2015-10-14 | Lg化学株式会社 | Binder for secondary battery, and secondary battery including same |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4936440B2 (en) | 2006-10-26 | 2012-05-23 | 日立マクセルエナジー株式会社 | Non-aqueous secondary battery |
| CN101728509B (en) * | 2008-10-27 | 2012-01-11 | 财团法人工业技术研究院 | Lithium battery, positive electrode and formation method thereof |
| EP2458671A1 (en) * | 2009-07-21 | 2012-05-30 | Panasonic Corporation | Rectangular nonaqueous electrolyte secondary battery and method for manufacturing same |
| WO2017099248A1 (en) * | 2015-12-11 | 2017-06-15 | 富士フイルム株式会社 | Solid electrolyte composition, binder particle, all-solid secondary battery sheet, all-solid secondary battery electrode sheet and all-solid secondary battery, and production method therefor |
| US10263257B2 (en) * | 2016-09-22 | 2019-04-16 | Grst International Limited | Electrode assemblies |
| JP7032968B2 (en) * | 2018-03-27 | 2022-03-09 | Fdk株式会社 | Negative electrode for nickel-metal hydride secondary battery and nickel-metal hydride secondary battery |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1256015A (en) * | 1997-05-27 | 2000-06-07 | Tdk株式会社 | Electrode for non-aqueous electrolytic cells |
| JP2001196063A (en) * | 1999-10-26 | 2001-07-19 | Sumitomo Chem Co Ltd | Active material for nonaqueous secondary battery and nonaqueous secondary battery using the same |
| JP2003203631A (en) * | 2002-01-08 | 2003-07-18 | Sony Corp | Positive electrode active material and non-aqueous electrolyte secondary battery |
| CN1515041A (en) * | 2002-01-08 | 2004-07-21 | 索尼株式会社 | Positive plate active material and nonaqueous electrolyte secondary cell using same |
-
2005
- 2005-11-30 CN CNB2005101285502A patent/CN100421286C/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1256015A (en) * | 1997-05-27 | 2000-06-07 | Tdk株式会社 | Electrode for non-aqueous electrolytic cells |
| JP2001196063A (en) * | 1999-10-26 | 2001-07-19 | Sumitomo Chem Co Ltd | Active material for nonaqueous secondary battery and nonaqueous secondary battery using the same |
| JP2003203631A (en) * | 2002-01-08 | 2003-07-18 | Sony Corp | Positive electrode active material and non-aqueous electrolyte secondary battery |
| CN1515041A (en) * | 2002-01-08 | 2004-07-21 | 索尼株式会社 | Positive plate active material and nonaqueous electrolyte secondary cell using same |
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| CN104981927A (en) * | 2013-05-23 | 2015-10-14 | Lg化学株式会社 | Binder for secondary battery, and secondary battery including same |
| CN104981927B (en) * | 2013-05-23 | 2018-06-08 | Lg化学株式会社 | Adhesive for secondary cell and the secondary cell comprising the adhesive |
| US10044041B2 (en) | 2013-05-23 | 2018-08-07 | Lg Chem, Ltd. | Binder for secondary batteries and secondary battery including the same |
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