CN106104874A

CN106104874A - Lithium ion secondary battery electrode adhesive composition, electrode slurry for lithium ion secondary battery compositions, electrode for lithium ion secondary battery and lithium rechargeable battery

Info

Publication number: CN106104874A
Application number: CN201580014889.1A
Authority: CN
Inventors: 王键; 召田郁哉; 福峰真弓
Original assignee: Nippon Zeon Co Ltd
Current assignee: Zeon Corp
Priority date: 2014-04-02
Filing date: 2015-03-31
Publication date: 2016-11-09
Anticipated expiration: 2035-03-31
Also published as: KR102255281B1; WO2015151518A1; JPWO2015151518A1; JP6477690B2; CN106104874B; KR20160138960A

Abstract

It is an object of the invention to provide and a kind of can manufacture the low lithium rechargeable battery of internal resistance and productivity and the outstanding lithium ion secondary battery electrode adhesive composition of caking property both sides.The lithium ion secondary battery electrode adhesive composition of the present invention contains polymer and disperse medium, this polymer be by the lithium salts of the unsaturated acids containing 10～80 mass % (monomer a), 5～40 the unsaturated acids of mass % (monomer b), 10～85 α of mass %, (monomer composition of monomer c) carries out being polymerized beta unsaturated nitrile.

Description

Lithium ion secondary battery electrode adhesive composition, lithium ion secondary battery electrode With paste compound, electrode for lithium ion secondary battery and lithium rechargeable battery

Technical field

The present invention relates to lithium ion secondary battery electrode adhesive composition, electrode slurry for lithium ion secondary battery group Compound, electrode for lithium ion secondary battery and lithium rechargeable battery.

Background technology

Lithium rechargeable battery has small-sized and light weight and energy density is high and then rechargeable characteristic, uses In purposes widely.Therefore, in recent years using the further high performance of lithium rechargeable battery as target, electricity is being studied The improvement of the battery components of pole etc..

Here, the electrode of lithium rechargeable battery is generally of collector body and the electrode composite wood being formed on collector body The bed of material.And, electrode composite material layer by such as using make adhesive composition containing the polymer as binding material with The paste compound that electrode active material etc. are scattered in the disperse medium such as organic solvent, water is coated with on the current collector, makes It is dried and is bondd by electrode active material etc. with polymer, is consequently formed.

Therefore, improve to realize the further performance of lithium rechargeable battery, be try in the formation of electrode institute The adhesive composition of use, the improvement of paste compound.

Specifically, it is proposed that by containing being used for than the adhesive composition of the polymer comprising multiple monomeric unit with specific The manufacture of the electrode of lithium ion battery etc..Such as, patent documentation 1 reports following main points, i.e. by make to comprise 80～ The repetitive from the monomer containing itrile group of 99.9 weight % and comprise the second with carboxylic acid group of 0.1～20 weight % Alkenyl monomer etc. are contained in adhesive composition from the polymer of the repetitive of alefinically unsaturated compounds as binding material In such that it is able to improve the stability of adhesive composition and the paste compound using this adhesive composition to prepare, and The cycle characteristics of the secondary cell using this adhesive composition to make can be improved.

Prior art literature

Patent documentation

Patent documentation 1: International Publication the 2012/091001st.

Summary of the invention

The problem that invention is to be solved

But, in the synthesis of the polymer contained by the adhesive composition of above-mentioned prior art, a large amount of use contains nitrile The monomer of base causes there is the tendency that the most substantial amounts of polymerization reactant separates out, the polyreaction stage in early days terminates. Accordingly, there exist monomer the highest to the conversion ratio (polymerisation conversion) of polymer is 70% the lowest value only, material cost Higher, and become the problem in the manufacture of difficulty for the post processing (such as, filtration treatment etc.) of the monomer that removes residual.

Additionally, in the adhesive composition of above-mentioned prior art, there is also such as when in order to improve as polymer Caking property and when increasing the use level of the vinyl monomer with carboxylic acid group, polymerization reactant can its of coagulation in the polymerization The problem that it manufactures.

And then, in the adhesive composition of above-mentioned prior art, use the lithium ion two that this adhesive composition makes The internal resistance of primary cell is high, therefore has room for improvement.

Therefore, it is an object of the invention to provide and a kind of can manufacture the low lithium rechargeable battery of internal resistance and produce Property and the outstanding lithium ion secondary battery electrode adhesive composition of caking property both sides.It is further an object that carry For a kind of lithium ion secondary battery electrode that can prepare the electrode for lithium ion secondary battery that internal resistance is low and peel strength is outstanding Use paste compound.And then, it is an object of the invention to provide the lithium ion secondary electricity that a kind of internal resistance is low and peel strength is outstanding Pond electrode.

It is further an object that provide a kind of internal resistance low lithium rechargeable battery.

For solving the scheme of problem

The present inventor conducts in-depth research for the purpose of solving above-mentioned problem.Then, the inventors discovered that, will be by spy The monomer that fixed compound is formed carries out the polymer being polymerized with special ratios, and caking property is high, and can be to have Gao Sheng The mode of producing property is prepared, and can bring the reduction of internal resistance when for the manufacture of lithium rechargeable battery, so that complete Become the present invention.

That is, the present invention is for the purpose of advantageously solving above-mentioned problem, the lithium ion secondary battery electrode bonding of the present invention Agent compositions is characterised by, containing polymer and disperse medium, this polymer is by the unsaturation containing 10～80 mass % The lithium salts of acid (monomer a), 5～40 unsaturated acids (monomer b), 10～85 'alpha ', ' bela '-unsaturated nitrile (monomers of mass % of mass % C) monomer composition carries out being polymerized.Like this, by by lithium salts (monomer a), the unsaturated acids (monomer of unsaturated acids B) and α, alpha, beta-unsaturated nitriles (monomer c) makes it be polymerized so that regulation ratio uses such that it is able to by polymer high for caking property and Lithium ion secondary battery electrode adhesive composition containing this polymer is prepared in the way of having high productivity.And And, according to the adhesive composition containing this polymer, it is possible to manufacture the lithium rechargeable battery that internal resistance is low.

Here, in the lithium ion secondary battery electrode adhesive composition of the present invention, the most above-mentioned α, β-unsaturation (monomer c) is acrylonitrile to nitrile.Because at above-mentioned α, alpha, beta-unsaturated nitriles is (in the case of monomer c) is acrylonitrile, it is possible to increase obtain The mechanical strength of polymer and oxidative resistance.

Additionally, the present invention is for the purpose of advantageously solving above-mentioned problem, the lithium ion secondary battery electrode slurry of the present invention Feed composition is characterised by, containing above-mentioned lithium ion secondary battery electrode adhesive composition and electrode active material. Like this, starch according to the lithium ion secondary battery electrode containing above-mentioned lithium ion secondary battery electrode adhesive composition Feed composition, it is possible to the preparation electrode for lithium ion secondary battery that peel strength is outstanding and internal resistance is low.

Furthermore it is preferred that the electrode slurry for lithium ion secondary battery compositions of the present invention contains further except above-mentioned polymerization Polymer beyond thing.Because starching by making the polymer in addition to above-mentioned polymer be contained in lithium ion secondary battery electrode In feed composition, the adhesion that electrode composite material layer and collector body can be improved and the output of the lithium rechargeable battery obtained Characteristic.

And then, in the electrode slurry for lithium ion secondary battery compositions of the present invention, preferably except above-mentioned polymer with Outer polymer is fluoropolymer.Because by making fluoropolymer be contained in electrode slurry for lithium ion secondary battery compositions In, the output spy of the adhesion that can improve electrode composite material layer and collector body further and the lithium rechargeable battery obtained Property.

And, the present invention for the purpose of advantageously solving above-mentioned problem, the electrode for lithium ion secondary battery of the present invention It is characterised by there is electrode on the current collector that use above-mentioned electrode slurry for lithium ion secondary battery compositions to prepare and be combined Material layer.The internal resistance of such electrode for lithium ion secondary battery is low, and has outstanding peel strength.

And, the present invention is for the purpose of advantageously solving above-mentioned problem, and the feature of the lithium rechargeable battery of the present invention exists In, there is positive pole, negative pole, electrolyte and distance piece, at least one party in above-mentioned positive pole and negative pole is above-mentioned lithium ion secondary Electrode for cell.The internal resistance of such lithium rechargeable battery is low.

Invention effect

In accordance with the invention it is possible to provide a kind of can manufacture the low lithium rechargeable battery of internal resistance and productivity and bonding The lithium ion secondary battery electrode adhesive composition that property both sides are outstanding.Additionally, in accordance with the invention it is possible to offer one can The electrode slurry for lithium ion secondary battery combination of the preparation electrode for lithium ion secondary battery that internal resistance is low and peel strength is outstanding Thing.And then, in accordance with the invention it is possible to provide the electrode for lithium ion secondary battery that a kind of internal resistance is low and peel strength is outstanding.

Additionally, in accordance with the invention it is possible to provide a kind of internal resistance low lithium rechargeable battery.

Detailed description of the invention

Hereinafter, embodiments of the present invention are described in detail.

Here, the lithium ion secondary battery electrode adhesive composition of the present invention can prepare lithium rechargeable battery Use during slurry composition for electrode.And, the electrode slurry for lithium ion secondary battery compositions of the present invention can use this Prepared by lithium ion secondary battery electrode adhesive composition and the electrode active material of invention, can manufacture lithium ion secondary Use during the electrode of battery.Additionally, the electrode for lithium ion secondary battery of the present invention can use the lithium ion secondary of the present invention Battery electrode paste compound manufactures.And then, the lithium rechargeable battery of the present invention is characterised by, employs the present invention's Electrode for lithium ion secondary battery.

(lithium ion secondary battery electrode adhesive composition)

The lithium ion secondary battery electrode adhesive composition of the present invention contains polymer and disperse medium, this polymer Be by the lithium salts of the unsaturated acids containing 10～80 mass % (monomer a), 5～40 mass % unsaturated acids (monomer b), 10～ (monomer composition of monomer c) carries out being polymerized for the 'alpha ', ' bela '-unsaturated nitrile of 85 mass %.Additionally, the lithium ion two of the present invention Primary cell binder composition for electrode can arbitrarily contain other composition in addition to above-mentioned polymer and disperse medium.

The polymer contained by lithium ion secondary battery electrode adhesive composition of the present invention is to use this binding agent When compositions manufactures electrode, can in the electrode through manufacturing composition contained by holding electrode composite layer (such as, positive pole is lived The property electrode active material such as material, negative electrode active material) not from electrode composite material pull-up from composition.

And, the polymer contained by lithium ion secondary battery electrode adhesive composition of the present invention can be by specify ratio Example contains the lithium salts of unsaturated acids, and (((monomer c) is as the list of monomer for monomer b) and 'alpha ', ' bela '-unsaturated nitrile for monomer a), unsaturated acids Body compositions is polymerized and is obtained.It addition, (below, monomer composition can arbitrarily contain the monomer in addition to above-mentioned monomer It is sometimes referred to as " other monomer ").

Here, with regulation in the polymer contained by the lithium ion secondary battery electrode adhesive composition of the present invention Ratio contains lithium salts from the unsaturated acids (unit of monomer a) and (unit of monomer b), therefore should be from from unsaturated acids Lithium ion in the unit of the lithium salts of unsaturated acids combined with being coordinated from a part for the acidic group in the unit of unsaturated acids And form cross-linked structure.And, according to such cross-linked structure, mechanical strength and electrolyte resistance as polymer improve. Therefore, the polymer obtained can play outstanding caking property, and can improve when for the manufacture of lithium rechargeable battery The battery behavior (such as, cycle characteristics and High temperature storage characteristic) of this lithium rechargeable battery.

Additionally, the polymer contained by lithium ion secondary battery electrode adhesive composition of the present invention contains from insatiable hunger (unit of monomer a), therefore lithium-ion-conducting is outstanding with the lithium salts of acid.Therefore, if using the binding agent containing polymer Compositions, then can reduce the internal resistance of electrode and lithium rechargeable battery.

And then, in the synthesis of the polymer contained by the lithium ion secondary battery electrode adhesive composition of the present invention, From the lithium salts of unsaturated acids, (existence of the lithium salts (anion component) of monomer a) results in Coulomb repulsion.Therefore, though Use unsaturated acids (in the case of monomer b) improves the caking property of polymer, it is also possible to avoid being polymerized in the polymerization anti- Answer thing coagulation.Additionally, in the synthesis of above-mentioned polymer, as monomer and (monomer a), unsaturated with the lithium salts of unsaturated acids (monomer b) and α, (monomer c), therefore, it is possible to suppress polymerization reactant in the polymerization to separate out, it is possible to big for alpha, beta-unsaturated nitriles in acid Width improves the monomer conversion ratio (polymerisation conversion) to polymer.And, in view of these aspects, above-mentioned polymer and containing should The lithium ion secondary battery electrode adhesive composition of the present invention of polymer, because the monomer in order to remove residual can be made Post processing become easy or need not, and manufacturing cost can be made to become lower, it is possible to have high productivity Mode is prepared.It addition, knowable to above-mentioned situation, in the present invention, monomer composition just contains monomer a when polymerization and is Vital, it is to obtain by making to carry out lithium salts from the unit of monomer b after being polymerized by monomer b and monomer c To above-mentioned effect.

Hereinafter, the preparation to the polymer contained by the lithium ion secondary battery electrode adhesive composition of the present invention makes Monomer composition in contained each monomer be described in detail.

The lithium salts of the unsaturated acids [(monomer a)]

Monomer composition must at least contain lithium salts (the monomer a) of unsaturated acids.

Here, the lithium salts of above-mentioned unsaturated acids is because as neccessary composition in the salt of unsaturated acids, when only using The sodium salt of such as unsaturated acids, other salt such as potassium salt of unsaturated acids, when not using the lithium salts of unsaturated acids, the polymer obtained There is the movement hindering the lithium ion in lithium rechargeable battery (such as, to the embedding of electrode active material and from electrode activity thing The deintercalation of matter) risk, and the relatively easy step-down of dissolubility in the organic solvents such as N-Methyl pyrrolidone, therefore without Method obtains desired effect (such as, the raising etc. of battery performance).

Lithium salts as above-mentioned unsaturated acids is not particularly limited, and can enumerate the lithium salts of unsaturated carboxylic acid, unsaturated sulfonic acid Lithium salts, the lithium salts etc. of unsaturated phosphonic acids.Among those, the lithium salts as unsaturated acids is preferably used the lithium of unsaturated carboxylic acid Salt, the lithium salts of unsaturated sulfonic acid.Because the lithium salts of the lithium salts of unsaturated carboxylic acid and unsaturated sulfonic acid easily obtains, and it is polymerized anti- Ying Xinggao, if therefore using these lithium salts, then can improve the productivity of adhesive composition further.Additionally, it is unsaturated The degree of dissociation of the lithium ion of the lithium salts of carboxylic acid and the lithium salts of unsaturated sulfonic acid is high, if therefore using these lithium salts, then can enter One step reduces the internal resistance of lithium rechargeable battery.

Here, as the lithium salts of above-mentioned unsaturated carboxylic acid, can enumerate: the α, β such as acrylic acid, methacrylic acid .beta.-methylacrylic acid-no The lithium salts of saturated monocarboxylic acid；The α such as maleic acid, fumaric acid, itaconic acid, the lithium salts of β-unsaturated dicarboxylic；Monomethyl maleate, clothing The lithium salts of the partial esterification thing of α, the β-unsaturation polybasic carboxylic acids such as health acid mono ethyl ester；Oleic acid, linoleic acid, linolenic acid, rumenic acid The lithium salts etc. of unsaturated fatty acids such as (Rumenic acid).

Additionally, as the lithium salts of above-mentioned unsaturated sulfonic acid, vinyl sulfonic acid, adjacent styrene sulfonic acid, a styrene can be enumerated The lithium salts of sulfonic acid, p styrene sulfonic acid, 2-acrylamide-2-methyl propane sulfonic acid (AMPS) etc. and their various replacement bodies Deng.

And then, as the lithium salts of above-mentioned unsaturated phosphonic acids, vinyl phosphonate, adjacent styryl phosphonic acid, a styrene can be enumerated Phosphonic acids, to the lithium salts of styryl phosphonic acid etc. and their various replacement bodies etc..

It addition, monomer composition can individually contain the lithium salts of a kind of unsaturated acids, it is also possible to contain 2 kinds with arbitrary proportion The lithium salts of above unsaturated acids.

Here, as the lithium salts of above-mentioned unsaturated acids, from improving the degree of dissociation of lithium ion further, reducing lithium further From the viewpoint of the internal resistance of ion secondary battery, particularly preferred Lithium acrylate, lithium methacrylate and p styrene sulfonic acid lithium.

It addition, as the lithium salts of above-mentioned unsaturated acids, it is possible to use the lithium salts of the most commercially available unsaturated acids, it is also possible to make By the unsaturation by making unsaturated acids and the alkaline, lithium compound such as lithium hydroxide monohydrate, lithium carbonate carry out reacting and prepare The lithium salts of acid.

And, in the present invention, the content of the lithium salts of the unsaturated acids in monomer composition is required to be more than 10 mass %, excellent Elect more than 15 mass % as.Because, when the content of the lithium salts of the unsaturated acids in monomer composition is less than 10 mass %, it is impossible to Polymerization stability, in the polymerization polymerization reactant coagulation is maintained with high level, therefore can not be to have the side of high productivity Formula prepares polymer.Additionally, the content of the lithium salts of unsaturated acids in monomer composition is required to be below 80 mass %, preferably 60 Below quality %, below more preferably 50 mass %.Because, when the content of the lithium salts of the unsaturated acids in monomer composition exceedes During 80 mass %, there is following risk: can not give sufficient flexibility to the polymer obtained, caking property declines, and inciting somebody to action The electrode using such polymer to prepare causes lead rupture etc. when being wound and manufacture lithium rechargeable battery, battery Manufacture becomes difficulty.

[unsaturated acids (monomer b)]

Additionally, monomer composition must at least contain unsaturated acids (monomer b).

It is not particularly limited as above-mentioned unsaturated acids, unsaturated carboxylic acid, unsaturated sulfonic acid, unsaturated phosphonic acids can be enumerated Deng.Among those, unsaturated carboxylic acid, unsaturated sulfonic acid are preferably used as unsaturated acids.Because, unsaturated carboxylic acid and insatiable hunger Easily obtain with sulfonic acid, and the caking property of polymer can be improved and improve electrode composite material layer and collector body further Adhesion.

Here, as above-mentioned unsaturated carboxylic acid, can enumerate: the α, β such as acrylic acid, methacrylic acid .beta.-methylacrylic acid-unsaturation is single Carboxylic acid；The α such as maleic acid, fumaric acid, itaconic acid, β-unsaturated dicarboxylic；The α such as monomethyl maleate, ethyl itaconate, β-no The partial esterification thing of saturated polybasic carboxylic acid；The unsaturated fatty acids etc. such as oleic acid, linoleic acid, linolenic acid, rumenic acid.

Additionally, as above-mentioned unsaturated sulfonic acid, vinyl sulfonic acid, adjacent styrene sulfonic acid, a styrene sulfonic acid, right can be enumerated Styrene sulfonic acid, 2-acrylamide-2-methyl propane sulfonic acid (AMPS) and their various replacement bodies etc..

And then, as above-mentioned unsaturated phosphonic acids, vinyl phosphonate, adjacent styryl phosphonic acid, a styryl phosphonic acid, right can be enumerated Styryl phosphonic acid and their various replacement bodies etc..

It addition, monomer composition can individually contain a kind of unsaturated acids, it is also possible to contain of more than two kinds with arbitrary proportion Unsaturated acids.

Here, as above-mentioned unsaturated acids, from improve further electrode composite material layer and the adhesion of collector body and And from the viewpoint of reducing frequency or the degree of polymerization reactant coagulation in the polymerization further, preferably acrylic acid, methyl Acrylic acid, p styrene sulfonic acid and vinyl sulfonic acid, particularly preferred acrylic acid and methacrylic acid.

It addition, as above-mentioned unsaturated acids, it is possible to use the most commercially available unsaturated acids, it is further possible to use this The substituted unsaturated acids such as the part halogen of the commercially available unsaturated acids of sample.

And, in the present invention, the content of the unsaturated acids in monomer composition is required to be more than 5 mass %, and preferably 10 More than quality %, more than more preferably 15 mass %.Because, when the content of the unsaturated acids in monomer composition is less than 5 matter During amount %, can not fully improve when using the adhesive composition containing the polymer obtained to prepare lithium ion battery electrode Collector body and the adhesion of electrode composite material layer.Additionally, the content of the unsaturated acids in monomer composition is required to be 40 mass % Hereinafter, below preferably 30 mass %, below more preferably 20 mass %.Because when containing of the unsaturated acids in monomer composition When amount is more than 40 mass %, it is impossible to be effectively prevented polymerization reactant coagulation in the polymerization.Additionally, because have polymer The risk that the internal resistance of lithium-ion-conducting decline, electrode and lithium rechargeable battery increases.

['alpha ', ' bela '-unsaturated nitrile (monomer c)]

And then, monomer composition must at least contain α, alpha, beta-unsaturated nitriles (monomer c).

As above-mentioned α, alpha, beta-unsaturated nitriles is not particularly limited, and can enumerate acrylonitrile, methacrylonitrile and theirs is various Replace body etc..

It addition, monomer composition can individually contain a kind of α, alpha, beta-unsaturated nitriles, it is also possible to arbitrary proportion contain 2 kinds with On 'alpha ', ' bela '-unsaturated nitrile.

Here, as above-mentioned α, alpha, beta-unsaturated nitriles, from the mechanical strength of the polymer guaranteeing to obtain with high level and resistance to From the viewpoint of oxidisability, preferably acrylonitrile or methacrylonitrile, particularly preferred acrylonitrile.By guaranteeing polymer with high level Mechanical strength and oxidative resistance, it is possible to make polymer play good caking property, and lithium rechargeable battery can be made to send out Wave good battery behavior (such as high-temperature cycle and High temperature storage characteristic).

It addition, as above-mentioned α, alpha, beta-unsaturated nitriles, it is possible to use the most commercially available α, alpha, beta-unsaturated nitriles, it is further possible to Use substituted 'alpha ', ' bela '-unsaturated nitriles such as the part halogens of such commercially available 'alpha ', ' bela '-unsaturated nitrile.

Additionally, in the present invention, the α in monomer composition, the content of alpha, beta-unsaturated nitriles is required to be more than 10 mass %, preferably It is more than 20 mass %, more than more preferably 30 mass %, more preferably more than 35 mass %.Because working as combination of monomers α in thing, when the content of alpha, beta-unsaturated nitriles is less than 10 mass %, the mechanical strength having a polymer obtained is insufficient, Bu Nengchong (such as high temperature follows point to improve the battery behavior of collector body and the adhesion of electrode composite material layer and lithium rechargeable battery Ring property and High temperature storage characteristic) risk that declines.Additionally, the α in monomer composition, the content of alpha, beta-unsaturated nitriles is required to be 85 matter Amount below %, below preferably 75 mass %, below more preferably 70 mass %.Because, as the α in monomer composition, β-no When the content of saturated nitriles is more than 85 mass %, there are the risk that can not realize the highest polymerisation conversion, and the polymerization obtained Thing becomes really up to the mark, uses such polymers manufacturing electrode for lithium ion secondary battery and lithium rechargeable battery to become difficulty.

[other monomer]

And then, monomer composition can arbitrarily contain the monomer (other monomer) in addition to above-mentioned monomer.As other Monomer is not particularly limited, and can enumerate the such as glass of this homopolymer when forming the weight average molecular weight homopolymer more than 10000 Transition temperature Tg is less than monomer (the monomer d) of room temperature.

[monomer d]

In the case of monomer composition contains monomer d, it is possible to increase the flexibility of the polymer obtained, it is ensured that high bonding Property.

It addition, monomer composition can individually contain a kind of monomer d, it is also possible to contain monomer of more than two kinds with arbitrary proportion d。

As long as here, as above-mentioned monomer d this homopolymer when forming the weight average molecular weight homopolymer more than 10000 Glass transformation temperature Tg is not particularly limited less than the monomer of room temperature, preferably shorter than 0 DEG C, more preferably less than-20 DEG C, can enumerate Such as (methyl) acrylate.As such (methyl) acrylate, acrylic acid methyl ester., ethyl acrylate, (first can be enumerated Base) (methyl) alkyl acrylate such as butyl acrylate.

It addition, in this manual, " (methyl) acrylic acid " in (methyl) acrylate etc. refers to acrylic acid and/or methyl Acrylic acid.

And, in the present invention, the content of the monomer d in monomer composition is preferably below 70 mass %, more preferably Below 45 mass %, more preferably below 20 mass %.Because, by the content of monomer d is set to below 70 mass %, The lithium salts from unsaturated acids in polymer, unsaturated acids and α, the amount of the unit of alpha, beta-unsaturated nitriles can be substantially ensured that, obtain To the desired effect brought by use polymer.

[preparation of polymer]

And, the polymer contained by lithium ion secondary battery electrode adhesive composition of the present invention limits the most especially Fixed, can be by the monomer group by containing above-mentioned each monomer (monomer a, monomer b, monomer c and other monomer) with above-mentioned ratio Compound is polymerized in such as water solvent thus manufactures.

It addition, in above-mentioned monomer composition, at monomer a (lithium salts of unsaturated acids) for by making monomer b (unsaturated Acid) carry out compound obtained by lithium salts in the case of, be not particularly limited, can prepare containing monomer b, monomer c and arbitrarily The monomer composition precursor of other monomer, with alkaline, lithium compound by a part of lithium of the monomer b in this monomer composition precursor Salinization and make monomer a, thus prepare monomer composition.In this case, the content of the monomer b in monomer composition precursor Can be set to be become by lithium salts the list of monomer a based on wanting the monomer a and the amount of monomer b that make to contain in monomer composition The amount of body b with want to make the total amount of the amount of monomer b that contains in monomer composition.

Here, the manufacture method of polymer is not particularly limited, it is possible to use such as solution polymerization process, suspension polymerization, Any one method in mass polymerization, emulsion polymerization etc..

Additionally, the additions such as ionic polymerization, radical polymerization, active free radical polymerization can be used to gather as polymerization Close.Additionally, known polymerization initiator can be used as polymerization initiator.

And, in the manufacture of polymer, owing to using above-mentioned polymer composition, the polymerization of monomer therefore can be made to turn Rate becomes more than 90%, preferably becomes more than 95%.Therefore, the residual quantity of each monomer after polyreaction is greatly reduced, because of This can make the post processing of residual monomer become easy or need not, and material cost becomes lower.

It addition, in the polymer manufactured as described above, with identical with the existence ratio of each monomer in monomer composition Ratio contain from the unit of monomer contained by the monomer composition for polymerization.

The lithium ion secondary battery electrode adhesive composition of the present invention contains disperse medium.Here, above-mentioned dispersion is situated between Matter can be the water-medium used when manufacturing above-mentioned polymer, it is also possible to is organic solvent.Specifically, will be at water solvent In the case of the aqueous dispersions of the polymer of middle polymeric monomer composite is directly prepared into adhesive composition, disperse medium can To be water, the water solvent such as aqueous solution used in this polymerization.Additionally, at such as polymeric monomer composite in water solvent After, in the case of making adhesive composition with organic solvent displacement water solvent, disperse medium can be organic solvent.Separately Outward, it is not particularly limited as above-mentioned organic solvent, N-Methyl pyrrolidone (NMP), acetonitrile, acetylpyridine, ring can be enumerated Pentanone, dimethylformamide, dimethyl sulfoxide, methylformamide, methyl ethyl ketone, furfural, ethylenediamine etc..It addition, as dividing Dispersion media, preferably organic solvent, more preferably N-Methyl pyrrolidone (NMP).

And, in the binder composition for secondary battery electrode of the present invention, as above-mentioned disperse medium, can be independent Containing a kind of solvent, it is also possible to contain solvent of more than two kinds with arbitrary proportion.

The lithium ion secondary battery electrode adhesive composition of the present invention can be beyond above-mentioned composition, containing joining The known any composition being combined in adhesive composition.In addition it is also possible to draw containing the polymerization used in the polymerization of polymer Send out the residue of agent etc..

(electrode slurry for lithium ion secondary battery compositions)

The electrode slurry for lithium ion secondary battery compositions of the present invention contains above-mentioned lithium ion secondary battery electrode to be used Adhesive composition and electrode active material.And, in the electrode slurry for lithium ion secondary battery compositions of the present invention, lithium Polymer contained by ion secondary battery slurry composition for electrode is as at least some of function of binding material.According to Use such electrode slurry for lithium ion secondary battery compositions, using the teaching of the invention it is possible to provide the lithium ion that peel strength is outstanding and internal resistance is low Electrode for secondary battery, and the lithium ion secondary that the internal resistance employing this electrode for lithium ion secondary battery can be provided low is electric Pond.

Here, in the electrode slurry for lithium ion secondary battery compositions of the present invention, can be at above-mentioned lithium ion two Beyond primary cell binder composition for electrode and electrode active material, arbitrarily contain conductive material, except adhesive composition institute The polymer beyond polymer that contains, other arbitrary additive etc..

Electrode active material is the material of transmission electronics in the electrode (positive pole, negative pole) of lithium rechargeable battery.Hereinafter, The electrode active material that used the electrode slurry for lithium ion secondary battery compositions of the present invention is (positive active material, negative Pole active substance) it is described in detail.

[positive active material]

It is not particularly limited as the positive active material coordinated in the paste compound of the present invention, it is possible to use at lithium The known positive active material used in the positive pole of ion secondary battery.Specifically, as positive active material, it is possible to use The composition metal of the compound containing transition metal such as transition metal oxide, transient metal sulfide, lithium and transition metal Oxide etc..It addition, such as Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo etc. can be enumerated as transition metal.

Here, as transition metal oxide, such as MnO, MnO can be enumerated₂、V₂O₅、V₆O₁₃、TiO₂、Cu₂V₂O₃, amorphous Matter V₂O-P₂O₅, noncrystalline MoO₃, noncrystalline V₂O₅, noncrystalline V₆O₁₃Deng.

As transient metal sulfide, TiS can be enumerated₂、TiS₃, noncrystalline MoS₂, FeS etc..

As lithium and the metal composite oxide of transition metal, the lithium-contained composite metal oxidation with layer structure can be enumerated Thing, there is the lithium-contained composite metal oxide of spinel structure, there is the lithium-contained composite metal oxide of olivine-type structure Deng.

As having the lithium-contained composite metal oxide of layer structure, the cobalt/cobalt oxide such as containing lithium can be enumerated (LiCoO₂), nickel oxide (LiNiO containing lithium₂), the lithium-contained composite oxide of Co-Ni-Mn, Ni-Mn-Al containing lithium composite oxygen Compound, the lithium-contained composite oxide of Ni-Co-Al, LiMaO₂And Li₂MbO₃Solid solution etc..It addition, as LiMaO₂With Li₂MbO₃Solid solution, such as xLiMaO can be enumerated₂·(1-x)Li₂MbO₃Deng.Here, x represents the satisfied number of 0 < x < 1, Ma table The transition metal of show that average oxidation state is 3+ more than a kind, Mb represents the transition gold of more than a kind that average oxidation state is 4+ Belong to.

It addition, in this manual, " average oxidation state " represents the average oxygen of above-mentioned " transition metal of more than a kind " Change state, mole and atomicity according to transition metal calculate.Such as, at " transition metal of more than a kind " by 50mol%'s Ni²⁺Mn with 50mol%⁴⁺In the case of formation, the average oxidation state of " transition metal of more than a kind " is (0.5) × (2+) + (0.5) × (4+)=3+.

As having the lithium-contained composite metal oxide of spinel structure, such as LiMn2O4 (LiMn can be enumerated₂O₄), manganese Acid lithium (LiMn₂O₄) a part of Mn by the compound of other Transition metal substituted.As object lesson, Li can be enumerated_s [Mn_2-tMc_t]O₄.Here, Mc represents the transition metal of more than a kind that average oxidation state is 4+.As the object lesson of Mc, can Enumerate Ni, Co, Fe, Cu, Cr etc..Additionally, t represents the satisfied number of 0 < t < 1, s represents the number of satisfied 0≤s≤1.It addition, as just Pole active substance, it is possible to use by Li_1+xMn_2-xO₄The rich lithium-spinel compound etc. that (0 < X < 2) represents.

As having the lithium-contained composite metal oxide of olivine-type structure, such as olivine-type LiFePO4 can be enumerated (LiFePO₄), olivine-type lithium manganese phosphate (LiMnPO₄) etc. by Li_yMdPO₄The olivine-type lithium phosphate compound represented.? This, Md represents the transition metal of more than a kind that average oxidation state is 3+, can enumerate such as Mn, Fe, Co etc..Additionally, y represents Meet the number of 0≤y≤2.And then, by Li_yMdPO₄In the olivine-type lithium phosphate compound represented, Md can be by other metal portion Divide and replace.As commutable metal, such as Cu, Mg, Zn, V, Ca, Sr, Ba, Ti, Al, Si, B and Mo etc. can be enumerated.

In above-mentioned, from improving the cycle characteristics of the secondary cell employing the positive pole with paste compound formation with initial From the viewpoint of capacity, cobalt/cobalt oxide (LiCoO containing lithium is preferably used as positive active material₂), Co-Ni-Mn containing lithium Composite oxides or olivine-type LiFePO4 (LiFePO₄)。

Additionally, from the viewpoint of the secondary cell employing the positive pole formed with paste compound is made high power capacity, As positive active material, positive active material containing at least one party in Mn and Ni is preferably used.Specifically, from lithium ion From the viewpoint of the high capacity of secondary cell, LiNiO is preferably used₂、LiMn₂O₄, rich lithium-spinel compound, LiMnPO₄、 Li[Ni_0.5Co_0.2Mn_0.3]O₂、Li[Ni_1/3Co_1/3Mn_1/3]O₂、Li[Ni_0.17Li_0.2Co_0.07Mn_0.56]O₂、LiNi_0.5Mn_1.5O₄Deng As positive active material, more preferably use LiNiO₂, rich lithium-spinel compound, Li [Ni_0.5Co_0.2Mn_0.3]O₂、Li[Ni_1/ ₃Co_1/3Mn_1/3]O₂、Li[Ni_0.17Li_0.2Co_0.07Mn_0.56]O₂Deng as positive active material, particularly preferably use Li [Ni_0.5Co_0.2Mn_0.3]O₂As positive active material.

It addition, the particle diameter of positive active material, specific surface area are not particularly limited, it is possible to the positive pole being set to using in the past Active substance is identical.

Here, in the case of the electrode slurry for lithium ion secondary battery compositions of the present invention is used in positive pole, should The content of the positive active material in paste compound is not particularly limited, such as relative to the paste compound of 100 mass parts Solid constituent, more than preferably 90 mass parts and below 98 mass parts.By the content of above-mentioned positive active material is set to This scope, it is possible to make the internal resistance of lithium ion secondary battery anode become suitable size, and lithium ion secondary can be improved The capacity of battery.

[negative electrode active material]

It is not particularly limited as the negative electrode active material coordinated in the paste compound of the present invention, it is possible to use at lithium The known negative electrode active material used in the negative pole of ion secondary battery.Specifically, generally use as negative electrode active material Adsorbable and release lithium material.It addition, as the adsorbable and material of release lithium, such as carbon-based negative electrode active matter can be enumerated Matter, metal system negative electrode active material and the negative electrode active material etc. that they are combined.

[carbon-based negative electrode active substance]

Carbon-based negative electrode active substance refers to embed the active substance using carbon as main framing of (also referred to as " adulterating ") lithium, makees For carbon-based negative electrode active substance, such as carbonaceous material and graphite material can be enumerated.

Here, as carbonaceous material, the easy stone of the structure that such as can easily vary carbon according to heat treatment temperature can be enumerated The difficult graphitized carbon etc. with the structure close to amorphous structure representated by inkization carbon, vitreous carbon.

As easy graphitized carbon, the material with carbon element using the tar asphalt obtained from oil or coal as raw material can be enumerated.If lifting Go out object lesson, then can enumerate coke, carbonaceous mesophase spherules (MCMB), mesophase pitch based carbon fiber, pyrolysis vapor grown carbon Fiber etc..

As difficult graphitized carbon, can enumerate such as phenol resin fired body, carbonized polyacrylonitrile fibre, quasi-isotropic carbon, Furfuryl alcohol resin fired body (PFA), hard carbon etc..

Additionally, as graphite material, the such as graphite such as native graphite, Delanium (graphite) can be enumerated.

[metal system negative electrode active material]

Metal system negative electrode active material is the active substance containing metal, is often referred to contain the unit that can embed lithium in the structure Element, the active substance that theoretical electric capacity is more than 500mAh/g relative to unit mass in the case of embedded in lithium.As Metal system active substance, can use such as lithium metal, can be formed lithium alloy elemental metals (such as, Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P, Pb, Sb, Si, Sn, Sr, Zn, Ti etc.) and alloy and their oxide, sulfide, nitride, Silicide, carbide, phosphide etc..

And, in metal system negative electrode active material, preferably silicon-containing active material (silicon system negative electrode active material).Because, By using silicon system negative electrode active material, it is possible to make lithium rechargeable battery high capacity.

As silicon system negative electrode active material, such as silicon (Si), siliceous alloy, SiO, SiO can be enumerated_x, use conductive carbon Coating or the complex etc. containing Si material Yu conductive carbon of Composite will be carried out containing Si material.It addition, these silicon systems bear Pole active substance can be used alone a kind, it is also possible to two or more is applied in combination.

As siliceous alloy, transition metal such as such as containing silicon, aluminum, ferrum can be enumerated, possibly together with the terres rares such as stannum and indium The alloy composite of element.

SiO_xIt is containing SiO and SiO₂In at least one party and the compound of Si, x is usually 0.01 less than 2.And And, SiO_xThe dismutation reaction of such as silicon monoxide (SiO) can be utilized to be formed.Specifically, SiO_xCan be by arbitrary poly- Heat treatment SiO in the presence of the polymer such as vinyl alcohol, generates silicon and silicon dioxide, is thus prepared.It addition, heat treatment can After SiO and arbitrary polymer are pulverized and mixed, in the environment of containing organic gas and/or steam, with 900 DEG C with Upper, the temperature of preferably more than 1000 DEG C is carried out.

As the complex containing Si material Yu conductive carbon, it is possible to enumerate such as by the polymer such as SiO, polyvinyl alcohol and appoint The crushed mixture of the material with carbon element of meaning carries out the change of heat treatment in the environment of such as comprising organic gas and/or steam Compound.It is further possible to by the side that the granule of SiO is utilized the chemical vapor deposition method coating surface employing organic gas etc. Method, the granule of SiO and graphite or Delanium are carried out by mechanochemical reaction the public affairs such as the method for composite particles (pelletize) The method known obtains.

It addition, the particle diameter of negative electrode active material, specific surface area are not particularly limited, it is possible to the negative pole being set to using in the past Active substance is identical.

Here, in the case of the electrode slurry for lithium ion secondary battery compositions of the present invention is used for negative pole, this slurry The content of the negative electrode active material in feed composition is not particularly limited, such as relative to the paste compound of 100 mass parts Solid constituent, more than preferably 90 mass parts and below 98 mass parts.By the content of above-mentioned negative electrode active material is set to this Scope, it is possible to make the internal resistance of lithium ion secondary battery cathode become suitable size, and lithium ion secondary electricity can be improved The capacity in pond.

Above-mentioned polymer contained by above-mentioned adhesive composition is using electrode slurry for lithium ion secondary battery combination In the electrode composite material layer of electrode for lithium ion secondary battery prepared by thing, play work at least partially as binding material With.

And, in the electrode slurry for lithium ion secondary battery compositions of the present invention, such as relative to 100 mass parts Electrode active material, to be equivalent to the gauge of solid constituent, with more than preferably 0.1 mass parts and below 10 mass parts, more preferably Ratio more than 0.5 mass parts and below 5 mass parts contains above-mentioned lithium ion secondary battery electrode adhesive composition.Logical Cross and the content of above-mentioned adhesive composition is set to this scope, it is possible to be reduced the internal resistance etc. of electrode for lithium ion secondary battery Desired effect, and the output characteristics of lithium rechargeable battery can be improved.

Conductive material is for guaranteeing electrode active material electrical contact each other.And, limit the most especially as conductive material Fixed, it is possible to use known conductive material.Specifically, as the conductive material of positive pole of lithium rechargeable battery, it is possible to make With such as: conductive carbon materials such as acetylene black, Ketjen black (registered trade mark), white carbon black, graphite；The fiber of various metals, paper tinsel etc..? Among these, from improving positive active material electrical contact each other, improving and employ the lithium of the positive pole formed with paste compound From the viewpoint of the electrical characteristics of ion secondary battery, as conductive material, be preferably used acetylene black, Ketjen black (registered trade mark), White carbon black, graphite, particularly preferably use acetylene black, Ketjen black (registered trade mark).

It addition, the use level of the conductive material in the lithium ion secondary battery positive electrode paste compound of the present invention does not has spy Do not limit, such as relative to the positive active material of 100 mass parts, more than preferably 1 mass parts and below 5 mass parts.When leading When the use level of electric material is very few, it is impossible to substantially ensure that electrode active material electrical contact each other, it is impossible to substantially ensure that lithium ion The electrical characteristics of secondary cell.On the other hand, when the use level of conductive material is too much, the stability of paste compound decline and The density of the electrode composite material layer in electrode declines, it is impossible to make lithium rechargeable battery high capacity fully.

Here, in the electrode slurry for lithium ion secondary battery compositions of the present invention, as binding material, can be upper Beyond the polymer of the adhesive composition stated, (below, it is sometimes referred to as " its containing the polymer in addition to such polymer Its polymer ").Because, by making other above-mentioned polymer be contained in electrode slurry for lithium ion secondary battery compositions, can Improve electrode composite material layer and the adhesion of collector body, the output characteristics of the lithium rechargeable battery obtained can be improved.

As other polymer, fluoropolymer, acrylonitrile polymer etc. can be enumerated.As above-mentioned fluoropolymer, can Enumerate the polymer of vinylidene-fluoride units more than containing 30 mass %, such as Kynoar etc., gather as aforesaid propylene nitrile Compound, can enumerate containing having more than the polymer of acrylonitrile unit of 85 mass %, such as polyacrylonitrile.Among those, from entering One step improves electrode composite material layer and the sight of the adhesion of collector body, the further output characteristics of raising lithium rechargeable battery Point considers, more preferably fluoropolymer.

It addition, the electrode slurry for lithium ion secondary battery compositions in the present invention comprises except above-mentioned adhesive composition In the case of the contained polymer (other polymer) beyond polymer, the content of this other polymer is not particularly limited, Be equivalent in the amount of solid constituent and the total amount of this other polymer at above-mentioned adhesive composition, preferably 10 matter Below amount more than % and 90 mass %, more than more preferably 20 mass % and below 80 mass %.By by other polymerization above-mentioned The content of thing is located at this scope, it is possible to improves electrode composite material layer and the adhesion of collector body further, and can enter one Step improves the output characteristics of lithium rechargeable battery.

In the electrode slurry for lithium ion secondary battery compositions of the present invention, can be beyond mentioned component, containing example As the viscosity modifiers such as reinforcing material, antioxidant, viscosifier, surfactant, dispersant, have suppression electrolyte decomposition The composition of electrolysis additive etc. of function.These other additives can use known additive, it is possible to uses such as It is recorded in the additive of International Publication the 2012/036260th, is recorded in the interpolation of Japanese Unexamined Patent Publication 2012-204303 publication Agent.

(preparation of electrode slurry for lithium ion secondary battery compositions)

The electrode slurry for lithium ion secondary battery compositions of the present invention can be by making above-mentioned each composition at organic solvent Middle dissolving or dispersion and be prepared.Specifically, by use ball mill, sand mill, ball mill, pigment dispersion machine, chipper, Above-mentioned each composition and organic solvent are mixed by the mixer of ultrasonic dispersing machine, homogenizer, planetary stirring machine, Filmix etc., It is thus possible to prepare paste compound.

It addition, as organic solvent, can directly use the organic solvent contained by adhesive composition, it is also possible in preparation Organic solvent is added during paste compound.And then, the mixing of above-mentioned each composition and organic solvent is usually room temperature～80 DEG C Scope carry out 10 minutes～a few hours.

(electrode for lithium ion secondary battery)

The electrode for lithium ion secondary battery of the present invention has the lithium ion that use obtains as described above on the current collector Electrode composite material layer prepared by slurry for secondary battery electrode compositions, electrode composite material layer at least contains electrode activity thing Matter and above-mentioned polymer.It addition, each composition of electrode active material etc. contained in electrode composite material layer is the present invention Composition contained in electrode slurry for lithium ion secondary battery compositions, the suitably existence ratio of these each compositions is with the present invention's The suitably existence ratio of each composition in electrode slurry for lithium ion secondary battery compositions is identical.The lithium ion secondary of the present invention Electrode for cell uses the adhesive composition of the present invention, therefore has high-peeling strength and low internal resistance.

The electrode for lithium ion secondary battery of the present invention can be obtained by such as in the following manner, i.e. is coated with on the current collector The electrode slurry for lithium ion secondary battery compositions that cloth obtains as described above, to coating lithium ion secondary on the current collector Battery electrode paste compound is dried, and thus obtains.That is, electrode for lithium ion secondary battery can be through such as slurry group The painting process of compound and the drying process of paste compound and obtain.

[painting process]

It is coated with method on the current collector the most especially as by above-mentioned electrode slurry for lithium ion secondary battery compositions Limit, it is possible to use known method.As concrete coating process, it is possible to use doctor blade method, infusion process, reverse roller coating Method, direct roll coating process, gravure method, squeezing and pressing method, spread coating etc..At this point it is possible to paste compound to be only coated on the one of collector body Face, it is also possible to be coated on two sides.After coating be dried before collector body on slurry film thickness can according to be dried obtained by electricity The thickness of pole composite layer suitably sets.

Here, as the collector body of coating sizing-agent compositions, as long as there is electric conductivity and there is electrochemistry durability Material is then not particularly limited.From the viewpoint of there is thermostability, as the material of collector body, preferably metal, the most such as Ferrum, copper, aluminum, nickel, rustless steel, titanium, tantalum, gold, platinum etc..Wherein, such as the particularly preferred aluminum of positive pole, as negative pole with preferably Copper.The material of collector body can be used alone a kind, it is also possible to two or more is applied in combination with arbitrary proportion.

[drying process]

It is not particularly limited as the method that the paste compound on collector body is dried, it is possible to use known side Method, can enumerate such as: utilize warm air, hot blast, low wet wind be dried；Vacuum drying；Utilize that infrared ray, electron beam etc. irradiate is dry Dry method.Like this by the paste compound on collector body is dried, form electrode composite material layer, energy on the current collector Access and there is collector body and the electrode for lithium ion secondary battery of electrode composite material layer.

It addition, after drying process, it is possible to use electrode composite material layer is implemented by mould press or roller press etc. Pressurized treatments.Pass through pressurized treatments, it is possible to increase electrode composite material layer and the adhesion of collector body, and electrode can be made Porosity declines.

Additionally, the example of other manufacture method of the electrode for lithium ion secondary battery as the present invention, powder body can be enumerated The method of forming.The powder body method of forming is following manufacture method, i.e. prepare the slurry compositions for manufacturing electrode for lithium ion secondary battery Thing, by this paste compound preparation composite particles containing electrode active material etc., is supplied to this composite particles on collector body, Carry out roll-in system, molding further according to expectation, thus form electrode composite material layer, thus obtain lithium rechargeable battery and use Electrode.Now, as paste compound, it is possible to use the paste compound as above-mentioned paste compound.

(lithium rechargeable battery)

The lithium rechargeable battery of the present invention has positive pole, negative pole, electrolyte and distance piece, and above-mentioned positive pole and negative pole are extremely A few side uses the electrode for lithium ion secondary battery of the present invention.The lithium rechargeable battery of the present invention uses above-mentioned lithium ion Electrode for secondary battery, therefore has low internal resistance.

As described above, the electrode for lithium ion secondary battery of the present invention can be used as at least one party of positive pole and negative pole.That is, Can be the electrode for lithium ion secondary battery of the most extremely present invention of the lithium rechargeable battery of the present invention, negative pole be other Known negative pole, it is also possible to be the lithium rechargeable battery electricity consumption that negative pole is the present invention of the lithium rechargeable battery of the present invention Pole, the most extremely other known positive pole, moreover, it is also possible to be positive pole and the both sides of negative pole of lithium rechargeable battery of the present invention Electrode for lithium ion secondary battery for the present invention.

As the electrolyte of lithium rechargeable battery, can use and such as supporting electrolyte is dissolved in nonaqueous solvent Nonaqueous electrolytic solution.Lithium salts is generally used as supporting electrolyte.As lithium salts, such as LiPF can be enumerated₆、LiAsF₆、LiBF₄、 LiSbF₆、LiAlCl₄、LiClO₄、CF₃SO₃Li、C₄F₉SO₃Li、CF₃COOLi、(CF₃CO)₂NLi、(CF₃SO₂)₂NLi、 (C₂F₅SO₂) NLi etc..Wherein, the most easily it is dissolved in solvent the LiPF of high degree of dissociation is shown₆、LiClO₄、CF₃SO₃Li。 These can be used alone a kind, it is also possible to two or more is applied in combination with arbitrary proportion.Use the support electricity that degree of dissociation is the highest Xie Zhi, lithium ion conductivity is the highest, therefore, it is possible to regulate lithium ion conductivity according to the kind of supporting electrolyte.

As nonaqueous solvent, it is not particularly limited as long as supporting electrolyte can be dissolved.If enumerating the example of nonaqueous solvent Son, then can enumerate: dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), Allyl carbonate (PC), carbon The carbonates such as acid butene esters (BC), Ethyl methyl carbonate (MEC)；The esters such as gamma-butyrolacton, methyl formate；1,2-dimethoxy The ethers such as ethane, oxolane；The sulfur-containing compound class such as sulfolane, dimethyl sulfoxide etc..Wherein, high, stable due to dielectric constant Voltage belt field width, therefore preferred carbonates.Nonaqueous solvent can be used alone a kind, it is also possible to by two or more with arbitrarily than Example is applied in combination.

Furthermore, it is possible to make electrolyte contain additive.As additive, the carbon such as such as vinylene carbonate (VC) can be enumerated Acid esters based compound.Additive can be used alone a kind, it is also possible to two or more is applied in combination with arbitrary proportion.Additionally, make For electrolyte than that described above, it is possible to use such as: the polymer dielectric such as polyethylene oxide, polyacrylonitrile；Will electrolysis Liquid is impregnated in the gel-polymer electrolyte matter of above-mentioned polymer dielectric；LiI、Li₃The inorganic solid electrolytes etc. such as N.

As distance piece, it is possible to use the distance piece being such as recorded in Japanese Unexamined Patent Publication 2012-204303 publication.At these Among, the electrode active material ratio that improve lithium rechargeable battery in thinning from the thickness that distance piece can be made overall and carry From the viewpoint of height is relative to the capacity of volume, preferably by polyolefin-based resins (polyethylene, polypropylene, polybutene, polychlorostyrene second Alkene) micro-porous film that formed.

As the concrete manufacture method of the lithium rechargeable battery of the present invention, can enumerate such as by positive pole and negative pole across Distance piece is overlapping, be wound with being corresponded to cell shapes, folding etc. and put in battery case, inject the electrolyte into In battery case and the method that seals.And then, wire netting can be put into as required；The anti-overcurrent such as electric fuse, PTC-element Element；Stereotypes etc., prevent the pressure of inside battery from rising, cross discharge and recharge.The shape of secondary cell can be Coin shape, button Any one in type, template, cylinder type, square, platypelloid type etc..

Embodiment

Hereinafter, based on embodiment, the present invention is specifically described, but the present invention is not limited to these embodiments.Separately Outward, in the following description, unless otherwise specified, [%] and [part] of expression amount is quality criteria.

It addition, below in an example, as a mode of the present invention, by the lithium rechargeable battery electricity of the present invention Pole adhesive composition is only used for positive pole and has made lithium rechargeable battery.

In embodiment and comparative example, the polymerisation conversion of monomer, the peel strength of lithium ion secondary battery anode, with And the low-temperature characteristics of lithium rechargeable battery, High temperature storage characteristic and high-temperature cycle make to comment using the following method respectively Valency.

When preparing monomer composition, the gross weight of each monomer being encased in autoclave (is loaded total weight of monomer Amount), the gross weight (charging feedstock gross weight) of the gross weight of deionized water (loading water weight) and whole raw materials carries out accurately Weigh.

Additionally, when using monomer composition to be polymerized, first choose a part for the polymerization reactant obtained, accurately Weigh its weight (being dried pre-polymerization reactant weight).Then, to this polymerization reactant chosen in hot-air drier with 120 DEG C temperature be dried 1 hour, its weight of accurate weighing (dried polymerization reactant weight) again.(gather after drying here, calculate Close reactant weight) ÷ (being dried pre-polymerization reactant weight) × 100, as the solid constituent rate (%) of polymerization reactant.

Then, [(charging feedstock gross weight) × (the solid constituent rate of polymerization reactant)-{ (charging feedstock gross weight is calculated Amount)-(loading water weight)-(loading total monomer weight) }] ÷ (loading total monomer weight) × 100, as the polymerization of monomer Conversion ratio (%).

The positive pole of preparation is cut into the rectangle of wide 1.0cm × long 10cm and makes test film.Then, at test film just The surface of composite layer side, pole attaches adhesive tape.Now, adhesive tape employs the adhesive tape of JISZ1522 defined. Afterwards, when adhesive tape is fixed on testing stand, determine by test film from end side towards another side with The stress when speed of 50mm/ minute is peeled off.It is measured 10 times, obtains the meansigma methods of stress, strong as peeling off Degree (N/m), is evaluated with following benchmark.Peel strength is the biggest, then it represents that the caking property of binding material is the most outstanding, positive pole is multiple Condensation material layer is the highest for the adhesion of collector body.

A: peel strength is more than 30N/m

B: peel strength is that 20N/m is less than 30N/m

C: peel strength is that 10N/m is less than 20N/m

D: peel strength is less than 10N/m

<low-temperature characteristics of lithium rechargeable battery>

In order to the low-temperature characteristics of the lithium rechargeable battery made is evaluated, measure IV resistance as following.- In the environment of 10 DEG C, charge to SOC (State Of with 1C (C is the numerical value represented by rated capacity (mA)/1 hour (h)) Charge: depth of charge) 50% after, carry out 15 seconds with 0.5C, 1.0C, 1.5C, 2.0C using the 50% of SOC respectively as center Charging and the electric discharge of 15 seconds, will in every case cell voltage after 15 seconds of (charged side and discharge side) relative to current value Draw, its gradient is obtained as IV resistance (Ω) (IV resistance when IV resistance and electric discharge during charging).To the IV obtained The value (Ω) of resistance is evaluated with following benchmark.IV resistance value is the least, then it represents that internal resistance is the least, low-temperature characteristics is the most outstanding.

A:IV resistance is 10 below Ω

B:IV resistance is more than 10 Ω and be 15 below Ω

C:IV resistance is more than 15 Ω and be 20 below Ω

D:IV resistance is more than 20 Ω

For the lithium rechargeable battery made, in the environment of 25 DEG C, charge to 4.3V by the current method of determining of 0.1C After, preserve 100 hours at 80 DEG C.(Open circuit voltage, with subscript to measure the open-circuit voltage before 80 DEG C of preservations start It is designated as " OCV ") and the OCV of the battery core (cell) after 100 hours is preserved at 80 DEG C, calculate the OCV after preserving 100 hours at 80 DEG C The ratio of the OCV before starting relative to 80 DEG C of preservations, as OCV sustainment rate, is evaluated with following benchmark.OCV sustainment rate The biggest, represent that High temperature storage characteristic is the most outstanding, i.e. life characteristic is the most outstanding.

A:OCV sustainment rate is more than 99.0%

B:OCV sustainment rate is 98.5% less than 99.0%

C:OCV sustainment rate is 98.0% less than 98.5%

D:OCV sustainment rate is less than 98.0%

<high-temperature cycle of lithium rechargeable battery>

In the environment of 45 DEG C, the lithium rechargeable battery made will be charged to 4.2V also by the current method of determining of 1.0C It is discharged to the operation of 3.0V as 1 circulation, by such operation 100 circulations repeatedly.Calculate by during 100 loop ends The ratio of capacitance when capacitance and 5 loop ends ((electricity during capacitance/5 loop ends during 100 loop ends Capacity) × 100) the charge/discharge capacity conservation rate (%) that represents, it is evaluated with following benchmark.Charge/discharge capacity conservation rate is more Greatly, represent that high-temperature cycle is the most outstanding.

A: charge/discharge capacity conservation rate is more than 95%

B: charge/discharge capacity conservation rate is 90% less than 95%

C: charge/discharge capacity conservation rate is 85% less than 90%

D: charge/discharge capacity conservation rate is less than 85%

(embodiment 1)

By the methacrylic acids of 30 parts, the deionized water of 300 parts, the lithium hydroxide monohydrate of 7.3 parts joins has In the autoclave of blender, it is stirred 10 minutes, with lithium hydroxide monohydrate by a part of lithium of methacrylic acid Salinization, obtains the methacrylic acid as monomer b water-soluble of the lithium methacrylate as monomer a containing 16 parts and 15 parts Liquid.Then, in the aqueous solution add to obtain using the acrylonitrile as monomer c of 69 parts, monomer composition is prepared.

In the monomer composition add to obtain as described above using the potassium peroxydisulfate as polymerization initiator of 0.5 part, Replacing with nitrogen, keep 3 hours at 70 DEG C, keep 3 hours at 85 DEG C, be polymerized, obtain containing polymer is uniform Aqueous dispersions.

Relative to this aqueous dispersions of 100 parts (solid constituents: 24.75), add the N-Methyl pyrrolidone of 350 parts (NMP), under reduced pressure evaporate the water and make NMP evaporate 40.62 parts, obtaining lithium ion secondary battery electrode binding agent and combine Thing (solid component concentration: 8%).

It addition, composition and the polymerisation conversion of the monomer composition prepared when being polymerized above-mentioned polymer are shown in Table 1.

Using the LiCoO as positive active material of 100 parts₂(Japan Chemical Industry company manufactures, trade name: Cellseed C-10N), the acetylene black as conductive material of 2 parts, be equivalent to the amount of solid constituent be calculated as 1 part as above-mentioned The adhesive composition prepared like that coordinates, and adds N-first further in the way of viscosity becomes 4000～5000mPa s After base ketopyrrolidine, mix with planetary stirring machine, prepare lithium ion secondary battery positive electrode paste compound.

Above-mentioned positive pole paste compound is coated the aluminium foil that thickness is 18 μm, after being dried 3 hours at 120 DEG C, carries out Roll-in system, obtains the positive pole with the anode composite material layer that thickness is 50 μm.The positive pole obtained is evaluated peel strength.Will knot Fruit is shown in Table 1.

The volume average particle size as negative electrode active material of 98 parts are 20 μm and specific surface area is 4.2m²The stone of/g Ink, the 40 mass % aqueouss of the SB as binding material of 1.0 parts (being equivalent to the amount of solid constituent) Dispersion liquid (Japanese auspicious father-in-law (strain) manufacture, BM-400B) and 1.0 parts (being equivalent to the amount of solid constituent) as viscosity modifier The sodium salt of carboxy methyl cellulose mix, add water further, mix with planetary stirring machine, prepare negative pole and use Paste compound.This negative pole paste compound is coated on the one side of the Copper Foil that thickness is 10 μm, is dried 3 hours at 110 DEG C After, carry out roll-in system, obtain the negative pole with the anode material layer that thickness is 60 μm.

Use aluminium sheet and the stacked film formed by acrylic resin on its two sides coating, make battery case.Then, from upper The positive pole stated and each end of negative pole remove electrode composite material layer, form Copper Foil or the place of aluminium foil exposure.Aluminum at positive pole The local welding Ni lug that paper tinsel exposes, the local welding Cu lug that the Copper Foil at negative pole exposes.Clip by polyethylene is micro-many The distance piece that pore membrane is formed is by the positive pole with lug obtained and the negative pole overlap with lug.The face of electrode towards employing The face of the face of the anode composite material layer side of positive pole and the anode material layer side of negative pole in opposite directions towards.By overlapping electrode Wind with distance piece and be housed in above-mentioned battery case.Then, electrolyte is injected wherein.As electrolyte, using will LiPF₆It is dissolved in ethylene carbonate and dimethyl carbonate in the way of becoming the concentration of 1 mole/L at 25 DEG C with volume ratio The electrolyte prepared in the mixed solvent that 1:2 is obtained by mixing.

Then, stacked film is packaged, makes the stacking battery core type secondary of the lithium rechargeable battery as the present invention Battery.To the stacking battery core type secondary cell obtained, think poorly of temperature characteristics, High temperature storage characteristic and high-temperature cycle.Will knot Fruit is shown in Table 1.

(embodiment 2,3)

When preparing monomer composition, by make monomer composition composition as shown in table 1 in the way of change methacrylic acid, Lithium hydroxide monohydrate and the use level of acrylonitrile, in addition, carried out similarly to Example 1, preparation/make electrode use Adhesive composition, positive pole paste compound, positive pole, negative pole, secondary cell, carry out various evaluation.Show the result in table 1 In.

(embodiment 4)

When preparing monomer composition, by make monomer composition composition as shown in table 1 in the way of change joining of acrylonitrile Resultant, and using the content of monomer d as shown in table 1 in the way of by as the butyl acrylate of monomer d, (weight average molecular weight exceedes Less than Tg=-54 DEG C of the homopolymer of 10000) coordinate in monomer composition, in addition, carry out similarly to Example 1, Preparation/make binder composition for electrode, positive pole paste compound, positive pole, negative pole, secondary cell, carries out various evaluation. Show the result in table 1.

(embodiment 5)

Employ as the following monomer composition prepared, in addition, carry out similarly to Example 1, preparation/system Make binder composition for electrode, positive pole paste compound, positive pole, negative pole, secondary cell, carry out various evaluation.By result It is shown in Table 1.

The acrylic acid of 29.78 parts, the deionized water of 300 parts, the lithium hydroxide monohydrate of 8.6 parts are joined to have and stir Mix in the autoclave of machine, be stirred 10 minutes, with Lithium hydrate by acrylic acid a part of lithium salts, obtain containing 16 The Lithium acrylate as monomer a of part and the acrylic acid aqueous solution as monomer b of 15 parts.Then, using 69 parts as list The acrylonitrile of body c adds in the aqueous solution obtained, and prepares monomer composition.

(embodiment 6,7)

When preparing monomer composition, by make monomer composition composition as shown in table 1 in the way of change acrylic acid, hydrogen-oxygen Change lithium monohydrate and the use level of acrylonitrile, in addition, carry out similarly to Example 5, preparation/make electrode binding Agent compositions, positive pole paste compound, positive pole, negative pole, secondary cell, carry out various evaluation.Show the result in table 1.

(embodiment 8)

When preparing monomer composition, by make monomer composition composition as shown in table 1 in the way of change joining of acrylonitrile Resultant, and the butyl acrylate as monomer d is coordinated at monomer composition in the way of as shown in table 1 using the content of monomer d In, in addition, carry out similarly to Example 5, preparation/make binder composition for electrode, positive pole paste compound, Positive pole, negative pole, secondary cell, carried out various evaluation.Show the result in table 1.

(embodiment 9)

Employ as the following monomer composition prepared, in addition, carry out similarly to Example 1, preparation/system Make binder composition for electrode, positive pole paste compound, positive pole, negative pole, secondary cell, carry out various evaluation.Will knot Fruit is shown in Table 1.

Using the p styrene sulfonic acid lithiums as monomer a of 16 parts (LiSS, Tosoh Organic Chemical Co., Ltd. manufacture), the methacrylic acid as monomer b of 15 parts, the acrylonitrile as monomer c of 69 parts and the deionization of 300 parts Water joins in the autoclave with blender, mixes, prepares monomer composition.

(embodiment 10,11)

When preparing monomer composition, by make monomer composition composition as shown in table 1 in the way of change styrene sulphur Acid lithium, methacrylic acid and the use level of acrylonitrile, in addition, carried out similarly to Example 9, preparation/make electrode use Adhesive composition, positive pole paste compound, positive pole, negative pole, secondary cell, carried out various evaluation.Show the result in table 1 In.

(embodiment 12)

When preparing monomer composition, by make monomer composition composition as shown in table 1 in the way of change joining of acrylonitrile Resultant, and the butyl acrylate as monomer d is coordinated at monomer composition in the way of as shown in table 1 using the content of monomer d In, in addition, carry out similarly to Example 9, preparation/make binder composition for electrode, positive pole paste compound, Positive pole, negative pole, secondary cell, carried out various evaluation.Show the result in table 1.

(embodiment 13)

The use level of adhesive composition is set to 0.5 part with the gauge being equivalent to solid constituent, coordinates with phase further When the amount in solid constituent is calculated as the Kynoar as other polymer (PVDF) (the Wu Yu chemical industrial company of 0.5 part Manufacture, trade name: KF#7208), in addition, carry out similarly to Example 1, preparation/make electrode binding agent combination Thing, positive pole paste compound, positive pole, negative pole, secondary cell, carried out various evaluation.Show the result in table 1.

(comparative example 1)

Employ as the following monomer composition prepared and lithium ion secondary battery electrode adhesive composition, remove Outside this, carry out similarly to Example 1, preparation/make binder composition for electrode, positive pole paste compound, positive pole, Negative pole, secondary cell, carried out various evaluation.Show the result in table 1.

Using the methacrylic acids as monomer b of 15 parts, the acrylonitrile as monomer c of 85 parts, the deionized water of 300 parts Add in the autoclave with blender, prepare monomer composition.

In the monomer composition add to obtain as described above using the potassium peroxydisulfate as polymerization initiator of 0.5 part, Replace with nitrogen, keep 3 hours at 70 DEG C, keep 3 hours at 85 DEG C, be polymerized, obtain containing uneven polymer The aqueous dispersions of coarse grain.

The aluminum sulfate of 1 part is added in this aqueous dispersions, by employing the filtration of water, solid constituent is cleaned 2 times, Obtain the polymer of solid.This polymer relative to 24.75 parts, adds the N-Methyl pyrrolidone (NMP) of 350 parts, is subtracting Pressure evaporates the water and makes NMP evaporate 40.62 parts, obtains lithium ion secondary battery electrode adhesive composition (solid Constituent concentration: 8%).

(comparative example 2,3)

When preparing monomer composition, by make monomer composition composition as shown in table 1 in the way of change methacrylic acid, Lithium hydroxide monohydrate and the use level of acrylonitrile, in addition, carried out similarly to Example 1, preparation/make electrode use Adhesive composition, positive pole paste compound, positive pole, negative pole, secondary cell, carried out various evaluation.Show the result in table 1 In.

(comparative example 4)

By the methacrylic acids of 27.26 parts, the deionized water of 300 parts, the sodium hydroxide of 6.8 parts joins has blender Autoclave in, be stirred 10 minutes, with sodium hydroxide by a part of lithium salts of methacrylic acid, obtain containing 16 The Sodium methacrylate. of part and the metering system aqueous acid of 15 parts.Then, the acrylonitrile of 69 parts is added to the water obtained In solution, prepare monomer composition.

[table 1]

Embodiment 1～13 according to table 1, contains monomer a～the combination of monomers of monomer c by using with regulation ratio Thing such that it is able to polymer is polymerized with the conversion ratio of more than 99%, and, by using containing such polymer Adhesive composition, thus the peel strength of electrode for lithium ion secondary battery and the low temperature spy of lithium rechargeable battery can be made Property, High temperature storage characteristic and high-temperature cycle with high level and are deposited.

Especially, according to embodiment 1～12, by the monomer a in regulation monomer composition～the content of monomer c, Various characteristic can be improved further.

On the other hand, in the comparative example 1 of table 1, monomer composition does not contains monomer a, and the content of monomer c is many in addition, therefore Polymerisation conversion is the lowest, and polymerization reactant can coagulation in polymerization.In addition understand, use the binding agent group of comparative example 1 The internal resistance of lithium-ion secondary battery that compound manufactures is high, and High temperature storage characteristic and high-temperature cycle are deteriorated.

Additionally, in the comparative example 2 of table 1, monomer composition surplus ground, therefore cannot be to the polymerization obtained containing monomer a Thing gives sufficient flexibility, and the content of monomer b is also few in addition, therefore can not maintain peel strength.In addition understand, due to surplus The ground content containing monomer a, monomer c is few, causes High temperature storage characteristic and high-temperature cycle to be deteriorated.

In addition understanding, in the comparative example 3 of table 1, monomer composition contains monomer a, but the content of monomer b and monomer c exists Outside prescribed limit, the therefore lithium ion conductivity of polymer and oxidative resistance step-down, use the adhesive composition system of comparative example 3 The High temperature storage characteristic of the lithium rechargeable battery made and high-temperature cycle are deteriorated.

And then understand, in the comparative example 4 of table 1, replace the lithium salts of unsaturated acids to use sodium salt, therefore lithium ion secondary electricity The internal resistance in pond is high, and High temperature storage characteristic and high-temperature cycle are deteriorated.

It addition, according to the embodiment 1 and 13 of table 1, when preparing electrode slurry for lithium ion secondary battery compositions, Even if in the binding agent group containing the polymer using the monomer composition comprising monomer a～c with regulation ratio to be polymerized Beyond compound, coordinate the polymer such as fluoropolymer in addition to such polymer, it is also possible to make various characteristic good.

Industrial applicability

The low lithium rechargeable battery of internal resistance and productivity can be manufactured in accordance with the invention it is possible to provide a kind of and glue The lithium ion secondary battery electrode adhesive composition that knot property both sides are outstanding.

Additionally, in accordance with the invention it is possible to provide a kind of can prepare the lithium ion secondary that internal resistance is low and peel strength is outstanding The electrode slurry for lithium ion secondary battery compositions of electrode for cell.

And then, in accordance with the invention it is possible to provide the lithium rechargeable battery electricity consumption that a kind of internal resistance is low and peel strength is outstanding Pole.

Claims

1. a lithium ion secondary battery electrode adhesive composition, containing polymer and disperse medium, described polymer is By the lithium salts i.e. monomer a of the unsaturated acids containing 10～80 mass %, 5～40 unsaturated acids i.e. monomer b, 10～85 of mass % The 'alpha ', ' bela '-unsaturated nitrile of the quality % i.e. monomer composition of monomer c carries out being polymerized.

Lithium ion secondary battery electrode adhesive composition the most according to claim 1, wherein,

Described 'alpha ', ' bela '-unsaturated nitrile i.e. monomer c is acrylonitrile.

3. an electrode slurry for lithium ion secondary battery compositions, containing the lithium rechargeable battery described in claim 1 or 2 Binder composition for electrode and electrode active material.

Electrode slurry for lithium ion secondary battery compositions the most according to claim 3, wherein,

Contain the polymer in addition to described polymer further.

Electrode slurry for lithium ion secondary battery compositions the most according to claim 4, wherein,

Polymer in addition to described polymer is fluoropolymer.

6. an electrode for lithium ion secondary battery, has the lithium used according to any one of claim 3～5 on the current collector Electrode composite material layer prepared by ion secondary battery slurry composition for electrode.

7. a lithium rechargeable battery, has positive pole, negative pole, electrolyte and distance piece, in described positive pole and negative pole at least One side is the electrode for lithium ion secondary battery described in claim 6.