CN105612641B

CN105612641B - Lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode and lithium rechargeable battery

Info

Publication number: CN105612641B
Application number: CN201480055323.9A
Authority: CN
Inventors: 村瀬智也; 杉本拓己; 召田郁哉
Original assignee: Nippon Zeon Co Ltd
Current assignee: Zeon Corp
Priority date: 2013-10-31
Filing date: 2014-10-29
Publication date: 2018-03-20
Anticipated expiration: 2034-10-29
Also published as: CN105612641A; KR102264698B1; KR20160082503A; JP6369473B2; WO2015064099A1; JPWO2015064099A1

Abstract

The present invention, which provides, can further improve performance, especially cycle characteristics and the speed characteristic of lithium rechargeable battery and the lithium ion secondary battery positive electrode paste compound that viscosity stability is excellent.The lithium ion secondary battery positive electrode of the present invention includes positive active material, conductive material, binding material and organic solvent with paste compound, and the BET specific surface area of conductive material is 400m²/ more than g, binding material includes the polymer Z of (methyl) alkyl acrylate monomer units of polymer Y, (3) containing 50~90 mass % of the nitrile group-containing monomeric unit of (1) fluoropolymer X, (2) containing 10~50 mass %, and fluoropolymer X ratio is 50~95 mass % in binding material.

Description

Lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode And lithium rechargeable battery

Technical field

The present invention relates to lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode and lithium ion Secondary cell.

Background technology

Lithium rechargeable battery has small-sized, lightweight and energy density high and can repeat characteristic as discharge and recharge, Have been used for extensive use.Therefore, in recent years, in order to realize the further high performance of lithium rechargeable battery, for electricity The improvement of the battery components such as pole is studied.Specifically, in the high performance of lithium rechargeable battery, due to that must carry High battery capacity, cycle characteristics and speed characteristic etc., therefore have studied by being improved battery components such as electrodes to improve Battery capacity, cycle characteristics and speed characteristic.

Here, the electrode that the positive pole of lithium rechargeable battery is generally configured with collector and formed on the current collector closes material layer (positive pole closes material layer).In addition, the positive pole closes material layer for example can make positive active material, conduction material by being coated with the current collector Material, binding material etc. are dispersed or dissolved in the paste compound that decentralized medium forms and it is dried and is formed.

In addition, as a rule, positive pole, which closes the amount of the positive active material in material layer and species, can influence lithium ion secondary electricity The battery capacity in pond, positive pole closes the amount of the conductive material in material layer and character can influence speed characteristic, and positive pole closes viscous in material layer The amount and cohesive force for tying material can influence the cycle characteristics of lithium rechargeable battery, speed characteristic.

Therefore, in the prior art, it has been proposed that by making the cohesive force of binding material improve, realize with a small amount of bonding Material ensures the cycle characteristics of lithium rechargeable battery so that positive pole closes the amount of positive active material and conductive material in material layer Increase be possibly realized, and then improve battery capacity and speed characteristic.

Specifically, such as in patent document 1, it is proposed that following scheme：By closing material layer for forming positive pole The not melt into by fluoropolymer and in 1-METHYLPYRROLIDONE is used in lithium ion secondary battery positive electrode paste compound Two kinds of different binding materials that fluoropolymer is not formed of component, so as to realize that positive pole closes material layer while caking property is ensured The increase of the amount of middle positive active material and conductive material.And then in patent document 1, by using to contain to certainty ratio The two kinds of not lithium ion secondary battery positive electrode paste compounds of fluoropolymer and fluoropolymer as binding material, improve The battery capacity of lithium rechargeable battery, cycle characteristics and speed characteristic.

In addition, for example in patent document 2, it is proposed that following scheme：By in lithium ion secondary battery positive electrode slurry The polymer, fluorine-containing poly- by the specific composition with 1- olefin units and (methyl) acrylate unit is used in composition The binding material that the polymer that compound and the insoluble component amount in 1-METHYLPYRROLIDONE are more than 50 mass % is formed, So as to realize that positive pole closes the increase of the amount of positive active material and conductive material in material layer while caking property is ensured.And then In patent document 2, by using including the specific composition with 1- olefin units and (methyl) acrylate unit The polymer that polymer, fluoropolymer and the insoluble component amount in 1-METHYLPYRROLIDONE are more than 50 mass % is made For the lithium ion secondary battery positive electrode paste compound of binding material, improve the battery capacity of lithium rechargeable battery, follow Ring property and speed characteristic.

Prior art literature

Patent document

Patent document 1：Japanese Unexamined Patent Publication 2003-223895 publications

Patent document 2：Japanese Unexamined Patent Publication 2004-172017 publications

The content of the invention

Problems to be solved by the invention

However, for the lithium ion secondary made using above-mentioned traditional lithium ion secondary battery positive electrode of paste compound For battery, room for improvement also be present in terms of battery performance, especially cycle characteristics and speed characteristic is further improved.

In addition, in recent years, it has been proposed that by improving the BET specific surface area of conductive material, improving the same of speed characteristic When reduce conductive material usage amount technology.But the present inventor etc. has found after further investigation, above-mentioned bonding has just been used For the above-mentioned conventional lithium ion anode of secondary battery paste compound of material, if in order to improve lithium rechargeable battery Speed characteristic and the BET specific surface area of conductive material is brought up into such as 400m²/ more than g, conductive material can be triggered to become easy Condense and cause the viscosity stability of paste compound to decline, the keeping quality of paste compound reduce the problem of, and for collection The coating of electric body can through when change the problem of.

Based on this, it is an object of the invention to provide can make the performance of lithium rechargeable battery, especially cycle characteristics And the lithium ion secondary battery positive electrode paste compound that speed characteristic further improves and viscosity stability is excellent.

In addition, it is an object of the invention to provide can make lithium rechargeable battery performance, especially cycle characteristics and The lithium ion secondary battery anode that speed characteristic further improves.

It is a further object of the invention to provide used the high performance lithium of the lithium ion secondary battery anode from Sub- secondary cell.

The method solved the problems, such as

The present inventor etc. are in depth studied for the purpose of solving above-mentioned problem.And then the present inventor etc. has found, Specific polymer X, Y, Z are included as gluing comprising the conductive material with given BET specific surface area and using given ratio Tie material lithium ion secondary battery positive electrode paste compound, viscosity stability it is excellent and can fully improve lithium from The cycle characteristics and speed characteristic of sub- secondary cell, so as to complete the present invention.

That is, the present invention is for the purpose of efficiently solving above-mentioned problem, lithium ion secondary battery positive electrode slurry of the invention Composition is characterised by, comprising positive active material, conductive material, binding material and organic solvent, the conductive material BET specific surface area is 400m²/ more than g, the binding material includes (1) fluoropolymer X, (2) contain more than 10 mass % really More than 50 mass % and below 90 mass % (methyl) third are contained in the polymer Y of the following nitrile group-containing monomeric units of 50 mass %, (3) The polymer Z of olefin(e) acid alkyl ester monomer unit, fluoropolymer X ratio described in the binding material are more than 50 mass % And 95 below mass %.Given polymer X, Y, Z have been used in this wise as fluorine-containing poly- in binding material and binding material Compound X ratio more than 50 mass % and below 95 mass % lithium ion secondary battery positive electrode paste compound, viscosity Excellent in stability and the cycle characteristics and speed characteristic that can fully improve lithium rechargeable battery.

It should be noted that in the present invention, " BET specific surface area " refers to that the BET based on nitrogen adsorption method compares table Area, it can be measured according to ASTM D3037-81.

Here, in the lithium ion secondary battery positive electrode paste compound of the present invention, the preferably fluoropolymer X's contains Amount is calculated as 9.5/0.5~5.5/4.5 relative to the ratio (X/Y) of the content of the polymer Y with quality criteria.If make X/Y Within the above range, then the dispersiveness and viscosity stability of paste compound can fully be improved.In addition, if make X/Y upper In the range of stating, then can while the caking property of binding material is substantially ensured that, further improve made using paste compound Lithium rechargeable battery cycle characteristics and speed characteristic.

In addition, in the lithium ion secondary battery positive electrode paste compound of the present invention, the preferably fluoropolymer X's contains Amount is calculated as 9.5/0.5~5.5/4.5 relative to the ratio (X/Z) of the content of the polymer Z with quality criteria.If make X/Z Within the above range, then it can substantially ensure that the caking property of binding material, further improve what is made using paste compound The cycle characteristics and speed characteristic of lithium rechargeable battery.

Further, in lithium ion secondary battery positive electrode paste compound of the invention, preferably described polymer Z also contains Monomeric unit containing acidic-group.If using the polymer Z containing the monomeric unit containing acidic-group, can be glued in abundant improve While tying the caking property of material, the circulation for further improving the lithium rechargeable battery made using paste compound is special Property.

Here, suppress slurry from while the cycle characteristics of the caking property of binding material and lithium rechargeable battery is improved From the viewpoint of the reduction of the viscosity stability of composition, the polymer Z is preferably comprised more than 10 mass % and 30 mass % The following monomeric unit containing acidic-group.

In addition, in the lithium ion secondary battery positive electrode paste compound of the present invention, preferably described polymer Y is in N- methyl Insoluble component amount in pyrrolidones is below 5 mass %.If the use of the insoluble component amount in 1-METHYLPYRROLIDONE is 5 Below quality % polymer Y, then can suppress the reduction of the viscosity stability of paste compound.

In addition, in the lithium ion secondary battery positive electrode paste compound of the present invention, preferably described polymer Z is in N- methyl Insoluble component amount in pyrrolidones is below 50 mass %.If it is using the insoluble component amount in 1-METHYLPYRROLIDONE Below 50 mass % polymer Z, then can suppress the reduction of the viscosity stability of paste compound.

It should be noted that in the present invention, " insoluble component amount of the polymer in 1-METHYLPYRROLIDONE " can make It is measured with the assay method described in the embodiment of this specification.

In addition, the lithium ion secondary battery anode of the present invention is characterised by, possess on the current collector using above-mentioned The positive pole that any lithium ion secondary battery positive electrode is formed with paste compound closes material layer.In this wise using possess using above-mentioned lithium from When the positive pole that sub- anode of secondary battery is formed with paste compound closes the lithium ion secondary battery anode of material layer, can fully it carry The cycle characteristics and speed characteristic of high-lithium ion secondary cell.

Further, lithium rechargeable battery of the invention is characterised by, comprising above-mentioned lithium rechargeable battery with just Pole, negative pole, electrolyte and dividing plate.When using above-mentioned lithium ion secondary battery anode in this wise, it can provide high performance Lithium rechargeable battery.

The effect of invention

According to the present invention it is possible to providing can make performance, especially cycle characteristics and the speed of lithium rechargeable battery special The lithium ion secondary battery positive electrode paste compound that property further improves and viscosity stability is excellent.

In addition, according to the present invention it is possible to provide performance, especially cycle characteristics and the speed that can make lithium rechargeable battery The lithium ion secondary battery anode that rate characteristic further improves.

Further, according to the present invention it is possible to provide high performance lithium rechargeable battery.

Embodiment

Hereinafter, it is described in detail for embodiments of the present invention.

Here, the lithium ion secondary battery positive electrode paste compound of the present invention is forming the positive pole of lithium rechargeable battery When use.In addition, the lithium ion secondary battery anode of the present invention is with the lithium ion secondary battery positive electrode using the present invention The positive pole formed with paste compound closes material layer and is characterized.In addition, the lithium rechargeable battery of the present invention is with the use present invention's Lithium ion secondary battery anode is characterized.

(lithium ion secondary battery positive electrode paste compound)

The lithium ion secondary battery positive electrode of the present invention slurry that paste compound is using organic solvent as decentralized medium Composition, it includes positive active material, conductive material, binding material and organic solvent.

In addition, the lithium ion secondary battery positive electrode paste compound of the present invention is characterised by, as conductive material, make It is 400m with BET specific surface area²/ more than g conductive material.

In addition, the lithium ion secondary battery positive electrode paste compound of the present invention is characterised by that binding material includes down Polymer X, Y, Z described in (1)~(3) are stated, and the ratio of the polymer X in binding material is more than 50 mass % and 95 matter Measure below %.

(1) fluoropolymer X

(2) the polymer Y containing more than 10 mass % and the following nitrile group-containing monomeric units of 50 mass %

(3) the polymer Z containing more than 50 mass % and below 90 mass % (methyl) alkyl acrylate monomer units

It should be noted that in the present invention, " (methyl) acrylic acid " represents acrylic acid and/or methacrylic acid.In addition, In the present invention, " include monomeric unit " and refer to " include the structure list from monomer in the polymer obtained using the monomer Member ".

As the positive active material in lithium ion secondary battery positive electrode paste compound is coordinated, do not limit especially It is fixed, known positive active material can be used.

Specifically, as positive active material, it is not particularly limited, can enumerates：Cobalt/cobalt oxide containing lithium (LiCoO₂), LiMn2O4 (LiMn₂O₄), the nickel oxide (LiNiO containing lithium₂), Co-Ni-Mn lithium-contained composite oxide, Ni- Mn-Al lithium-contained composite oxide, Ni-Co-Al lithium-contained composite oxide, olivine-type LiFePO4 (LiFePO₄), olive Stone-type lithium manganese phosphate (LiMnPO₄), with Li_1+xMn_2-xO₄Spinel compound, the Li for the lithium excess that (0 ＜ X ＜ 2) is represented [Ni_0.17Li_0.2Co_0.07Mn_0.56]O₂、LiNi_0.5Mn_1.5O₄Deng.

In above-mentioned, the lithium ion secondary of lithium ion secondary battery positive electrode paste compound formation has been used from raising From the viewpoint of battery capacity of the lithium rechargeable battery of positive electrode for battery etc., as positive active material, preferably using containing Cobalt/cobalt oxide (the LiCoO of lithium₂), the nickel oxide (LiNiO containing lithium₂), Co-Ni-Mn lithium-contained composite oxide, Ni-Co-Al Lithium-contained composite oxide, Li [Ni_0.17Li_0.2Co_0.07Mn_0.56]O₂Or LiNi_0.5Mn_1.5O₄。

It should be noted that the use level, particle diameter for positive active material are not particularly limited, can be with making in the past Positive active material is same.

Conductive material is for ensuring that the material of the electrical contact of positive active material to each other.In addition, in the lithium of the present invention Ion secondary battery positive pole is needed in 400m with the conductive material used in paste compound, its BET specific surface area²/ more than g, The BET specific surface area of preferred conductive material is in 500m²/ more than g, more preferably in 600m²/ more than g, further preferably in 700m²/g More than, it is additionally preferred in 3000m²/ below g, further preferably in 2000m²/ below g, further preferably in 1270m²/ below g, Particularly preferably in 900m²/ below g.

If the BET specific surface area of the conductive material used is in 400m²/ more than g, even if then the use level of conductive material is A small amount of, the migration that the positive pole that can also be formed using paste compound closes the electronics in material layer becomes easy, so that lithium The speed characteristic of ion secondary battery improves.In addition, if the BET specific surface area of the conductive material used is in 3000m²/ g with Under, then by being applied in combination with binding material described later, the dispersiveness and viscosity stabilization of paste compound can be adequately suppressed Property reduce.

Here, as conductive material, as long as the material with above-mentioned BET specific surface area, is not particularly limited, Known conductive material can be used.Specifically, as conductive material, can use acetylene black, Ketjen black (registration mark), Furnace black, graphite, carbon fiber, carbon thin slice (carbon flakes), carbon superbhort fiber are (for example, CNT, vapor phase growth Carbon fiber etc.) etc. conductive carbon material；The fibers of various metals, paper tinsel etc..Wherein, from the battery in holding lithium rechargeable battery From the viewpoint of fully improving speed characteristic while capacity, as conductive material, preferably using acetylene black or Ketjen black (registration Trade mark).

It should be noted that as conductive material, a kind of conduction with above-mentioned BET specific surface area can be used alone Material, can also by the two or more combination of conductive materials with mutually different BET specific surface area using and make mixed The BET specific surface area of conductive material reaches the size in above range.

Further, relative to every 100 mass parts of positive active material, the use level of conductive material is preferably 0.5 mass parts More than, it is further excellent more preferably below 2.5 mass parts preferably below 3.0 mass parts more preferably more than 1.0 mass parts Elect as below 2.0 mass parts.If the use level of conductive material is very few, positive active material can not be substantially ensured that each other sometimes Between electrical contact, can not fully improve the speed characteristic of lithium rechargeable battery.On the other hand, if the use level of conductive material Excessively, then existing causes the hidden danger that the viscosity stability of lithium ion secondary battery positive electrode paste compound reduces, and exists Causing the positive pole in lithium ion secondary battery anode to close the density of material layer reduces, can not fully realize lithium rechargeable battery High capacity hidden danger.

Binding material be by using the present invention lithium ion secondary battery positive electrode with paste compound on the current collector Formed positive pole close material layer and in the positive pole that manufactures, keep positive pole close composition contained in material layer not from positive pole close that material layer departs from into Point.Generally, the binding material in positive pole conjunction material layer is understood Electolyte-absorptive and is swelled, but can make when being impregnated in electrolyte Positive active material to each other, between positive active material and conductive material or conductive material bonds to each other, so as to prevent Positive active material etc. comes off from collector.

In addition, must be with given for the binding material in the lithium ion secondary battery positive electrode paste compound of the present invention Ratio include and can be dissolved or dispersed in following 3 kinds of polymer in the organic solvent as decentralized medium.

Specifically, binding material includes：

(1) fluoropolymer X,

(2) polymer Y containing more than 10 mass % and the following nitrile group-containing monomeric units of 50 mass % and

(3) the polymer Z containing more than 50 mass % and below 90 mass % (methyl) alkyl acrylate monomer units,

And when using 100 mass % is set to as the polymer that binding material includes, fluoropolymer X ratio needs More than 50 mass % and below 95 mass %.

So, if as binding material and making binding material using fluoropolymer X, polymer Y, polymer Z In fluoropolymer X ratio be 50~95 mass %, then can fully improve the lithium rechargeable battery using the present invention The cycle characteristics and speed characteristic for the lithium rechargeable battery that positive pole makes of paste compound, and even in having used BET In the case of the big conductive material of specific surface area, the viscosity stability of paste compound can also be made good.

Here, can be improved by using above-mentioned binding material paste compound viscosity stability and lithium from The cycle characteristics of sub- secondary cell and the mechanism of speed characteristic are still not clear, but can be speculated as mechanism as described below.

That is, fluoropolymer X caking property compared with polymer Z etc. is not high, is playing the work(of regulation paste compound viscosity Can while, formed positive pole close material layer when, can be present in positive pole close material layer in rather than clad anode active material, conduction material The surface of material.In addition, the polymer Y of the nitrile group-containing monomeric unit containing 10~50 mass % caking property is excellent, and coat The surface of conductive material and make the favorable dispersibility of conductive material, so as to improve the viscosity stability of paste compound.In addition, contain Have that the polymer Z of 50~90 mass % (methyl) alkyl acrylate monomer units caking property is excellent, and formed just The surface of clad anode active material when material layer is closed in pole and protect positive active material, so as to improve battery life, (circulation is special Property).Therefore, by making fluoropolymer X ratio more than 50 mass %, the conduction material in positive pole closes material layer can be prevented Material, positive active material are excessively coated by polymer Y, polymer Z, so as to improve the speed characteristic of lithium rechargeable battery.Separately Outside, by making fluoropolymer X ratio below 95 mass % and coordinating polymer Y and polymer Z, polymerization can be passed through Thing Y and improve the viscosity stability of paste compound, and caking property is ensured by polymer Z, so as to improve lithium ion secondary The cycle characteristics of battery.

It should be noted that binding material can also contain its in addition to fluoropolymer X, polymer Y and polymer Z Its polymer, but from the viewpoint of the effect above is obtained well, the ratio of other polymer is 10 preferably in binding material Below quality %, preferably binding material are only made up of fluoropolymer X, polymer Y and polymer Z.

[fluoropolymer X]

Fluoropolymer X is the polymer containing fluorine-containing monomer unit.Specifically, as fluoropolymer X, Ke Yilie Lift：The homopolymer or copolymer of more than a kind fluorochemical monomer, more than a kind fluorochemical monomer and do not contain the monomer of fluorine (hereinafter referred to as " not fluorochemical monomer ") copolymer.

It should be noted that the ratio of fluorine-containing monomer unit preferably exists generally more than 70 mass % in fluoropolymer X More than 80 mass %.In addition, the ratio of fluorine-containing monomer unit generally below 30 mass %, does not preferably exist in fluoropolymer X Below 20 mass %.

Here, as the fluorochemical monomer that can form fluorine-containing monomer unit, can enumerate：Vinylidene, tetrafluoroethene, six Fluoropropene, CTFE, PVF, perfluoroalkyl vinyl ether etc..Wherein, as fluorochemical monomer, preferably vinylidene.

In addition, as the not fluorochemical monomer that can form not fluorine-containing monomer unit, can enumerate can be total to fluorochemical monomer The poly- monomer for not containing fluorine, such as：The 1- alkene such as ethene, propylene, 1- butylene；Styrene, α-methylstyrene, to the tert-butyl group The aromatic ethenyl compounds such as styrene, vinyltoluene, chlorostyrene；The unsaturated nitrile compounds such as (methyl) acrylonitrile； (methyl) the acrylate chemical combination such as (methyl) methyl acrylate, (methyl) butyl acrylate, (methyl) 2-EHA Thing；(methyl) third such as (methyl) acrylamide, N- methylols (methyl) acrylamide, N- butoxymethyls (methyl) acrylamide Enamides；The vinyl chemical combination containing carboxyl such as (methyl) acrylic acid, itaconic acid, fumaric acid, crotonic acid, maleic acid Thing；The unsaturated compounds containing epoxy radicals such as allyl glycidyl ether, (methyl) glycidyl acrylate；(methyl) acrylic acid The unsaturated compounds containing amino such as dimethylamino ethyl ester, (methyl) acrylic acid diethylamino ethyl ester；Styrene sulfonic acid, ethene The unsaturated compounds containing sulfonic group such as base sulfonic acid, (methyl) allyl sulphonic acid；The sulfur-bearings such as 3- allyloxy -2- hydroxy propane sulfuric acid Acidic group unsaturated compound；The chloro- 2- phosphoric acid propyl ester of (methyl) acrylic acid -3-, 3- allyloxy -2- hydroxy propane phosphoric acid etc. are phosphorous Acidic group unsaturated compound etc..

In addition, as fluoropolymer X, polymer of the vinylidene as fluorochemical monomer is preferably used, and use Polymer of the PVF as fluorochemical monomer, has more preferably used polymer of the vinylidene as fluorochemical monomer.

Specifically, as fluoropolymer X, preferably the homopolymer (Kynoar) of vinylidene, vinylidene and The copolymer and polyvinyl fluoride of hexafluoropropene, more preferably Kynoar.

It should be noted that above-mentioned fluoropolymer X can be used alone, two or more can also be combined in addition Use.

Here, the fluoropolymer X Weight-average molecular based on polystyrene scaled value obtained from gel permeation chromatography Amount is preferably 100000~2000000, more preferably 200000~1500000, especially preferably 400000~1000000.

By making fluoropolymer X weight average molecular weight to suppress positive active material, conductive material in above range Depart from (dry linting) Deng material layer is closed from positive pole, in addition, the viscosity regulation of paste compound becomes easy.

In addition, fluoropolymer X glass transition temperature (Tg) preferably below 0 DEG C, more preferably below -20 DEG C, Particularly preferably below -30 DEG C.Fluoropolymer X Tg lower limit is not particularly limited, preferably more than -50 DEG C, more It is preferred that more than -40 DEG C.By making fluoropolymer X Tg to suppress positive active material, conductive material in above range Depart from (dry linting) Deng material layer is closed from positive pole.It should be noted that fluoropolymer X Tg can be by changing the list for polymerizeing The species of body is adjusted.It should be noted that Tg can use differential scanning calorimeter, based on JIS K7121；1987 enter Row measure.

Fluoropolymer X fusing point (Tm) preferably below 190 DEG C, more preferably 150~180 DEG C, more preferably 160~170 DEG C.By making fluoropolymer X Tm to obtain flexibility and dhering strength is excellent just in above range Pole.It should be noted that fluoropolymer X Tm can be by changing species or control polymerization temperature for the monomer of polymerization Degree etc. is adjusted.It should be noted that Tm can use differential scanning calorimeter, based on JIS K7121；1987 are surveyed It is fixed.

Here, above-mentioned fluoropolymer X manufacture method is not particularly limited, it is, for example, possible to use polymerisation in solution Any means in method, suspension polymerization, mass polymerization, emulsion polymerization etc..

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

In addition, fluoropolymer X with the dispersion liquid that is dispersed in decentralized medium or can be dissolved in molten in decentralized medium The state of liquid uses.As fluoropolymer X decentralized medium, as long as it can be uniformly dispersed or dissolve fluoropolymer X Decentralized medium, be not particularly limited, can use water, organic solvent, preferably using organic solvent.Need what is illustrated , as organic solvent, to be not particularly limited, can use used as the decentralized medium of paste compound it is organic molten Agent.

[polymer Y]

Polymer Y is the polymer containing more than 10 mass % and the following nitrile group-containing monomeric units of 50 mass %.It is specific next Say, as polymer Y, more than a kind of nitrile group-containing monomer can be enumerated and can be total to the monomer of the nitrile group-containing monomer copolymerization Polymers.In addition, as polymer Y, be not particularly limited, for example, can use to more than 10 mass % and 50 mass % with Under ratio acrylonitrile-butadiene copolymer (NBR) method known to for containing acrylonitrile unit hydrogenated and obtained Hydrogenated nbr.

It should be noted that polymer Y can also have the monomeric unit (fluorine-containing monomer unit) containing fluorine, but polymer The ratio of fluorine-containing monomer unit is generally below 40 mass %, preferably below 30 mass % in Y, polymer Y be with it is foregoing Polymer different fluoropolymer X.

Here, as the nitrile group-containing monomer that can form nitrile group-containing monomeric unit, α, β-olefinically unsaturated nitriles can be enumerated Monomer.In addition, as α, β-olefinically unsaturated nitriles monomer, as long as the α with itrile group, β-alefinically unsaturated compounds do not have then Especially limit, can enumerate for example, acrylonitrile；The alpha-halogen acrylonitrile such as α-chloroacrylonitrile, alpha-brominated acrylonitrile；Methyl-prop The alpha-alkyl acrylonitrile such as alkene nitrile, α-ethyl acrylonitrile；Etc..Wherein, from the cohesive force for improving the binding material comprising polymer Y From the viewpoint of, as nitrile group-containing monomer, preferably acrylonitrile and methacrylonitrile, more preferably acrylonitrile.

These monomers can be used alone or be used in combination of two or more.

In addition, the ratio of the nitrile group-containing monomeric unit in polymer Y is necessary for more than 10 mass % and below 50 mass %, It is preferred that more than 15 mass %, additionally, it is preferred that below 40 mass %, more preferably below 30 mass %.Because if The ratio of nitrile group-containing monomeric unit then can fully improve the viscous of the binding material comprising polymer Y more than 10 mass % Tie power；In addition, if the ratio of nitrile group-containing monomeric unit below 50 mass %, then can fully improve the viscous of paste compound Spend stability.

In addition, as can be not particularly limited, can enumerate with the monomer of nitrile group-containing monomer copolymerization：1- alkene, it is total to Conjugate diene compound, (methyl) acrylate compounds, the polymerizable compound etc. with hydrophilic radical.In addition, as energy Enough and nitrile group-containing monomer copolymerization monomer, preferably at least using 1- alkene or conjugated diene compound.That is, polymer Y is preferably wrapped Containing the monomeric unit from 1- alkene or the monomeric unit from conjugated diene compound.

It should be noted that conjugated diene compound is being used as can be with the situation of the monomer of nitrile group-containing monomer copolymerization Under, the conjugated diene monomeric unit from conjugated diene compound being present in polymer is optionally hydrogenated after polymerisation.

In addition, these monomers can be used alone or be used in combination of two or more.

Here, as 1- alkene, can enumerate for example：Ethene, propylene, 1- butylene etc..Wherein, as 1- alkene, preferably Ethene.

In addition, as conjugated diene compound, can enumerate for example：1,3- butadiene, isoprene, 2,3- dimethyl- The conjugated diene compound of the carbon numbers more than 4 such as 1,3- butadiene, 1,3- pentadienes.In these, preferred 1,3-butadiene.

In addition, as (methyl) acrylate compounds, can enumerate：Methyl acrylate, ethyl acrylate, acrylic acid positive third Ester, isopropyl acrylate, n-butyl acrylate, tert-butyl acrylate, isobutyl acrylate, acrylic acid n-pentyl ester, acrylic acid are different Pentyl ester, Hexyl 2-propenoate, heptylacrylate, 2-ethyl hexyl acrylate, 2-EHA, acrylic acid nonyl ester, decyl acrylate, The alkyl acrylates such as lauryl acrylate, n-myristyl base ester, stearyl acrylate ester；Methyl methacrylate, first Base ethyl acrylate, n propyl methacrylate, isopropyl methacrylate, n-BMA, methacrylic acid uncle Butyl ester, Isobutyl methacrylate, n-amylmethacrylate, isopentyl methacrylate, hexyl methacrylate, methyl-prop Olefin(e) acid heptyl ester, 2-Propenoic acid, 2-methyl-, octyl ester, 2-Ethylhexyl Methacrylate, nonyl methacrylate, decyl-octyl methacrylate, first The alkyl methacrylates such as base lauryl acrylate, methacrylic acid n-tetradecane base ester, stearyl methacrylate；Deng Deng.Wherein, go out from the viewpoint for improving dissolubilities and flexibility of the polymer Y in the organic solvent used as decentralized medium Hair, it is 4~10 preferably with the carbon number of the alkyl of non-carbonyl oxygen atoms bond as (methyl) acrylate compounds Alkyl acrylate, wherein, specific preferably n-butyl acrylate, 2-EHA and lauryl acrylate, more preferably N-butyl acrylate, 2-EHA.

In addition, as the compound that can polymerize with hydrophilic radical, can enumerate：Chemical combination with carboxylic acid group Thing, with sulfonic compound, the compound with phosphate, the compound with hydroxyl.It should be noted that from raising From the viewpoint of the cohesive force of binding material comprising polymer Y, hydrophilic radical is preferably carboxylic acid group or sulfonic group, more preferably For carboxylic acid group.

As the compound with carboxylic acid group, can enumerate：Monocarboxylic acid and its derivative, dicarboxylic acids and its acid anhydrides with And their derivative etc..

As monocarboxylic acid, can enumerate：Acrylic acid, methacrylic acid, crotonic acid etc..

As monocarboxylic acid derivative, can enumerate：2- ethylacrylic acids, iso-crotonic acid, α-acetoxypropen acid, β- Trans-aryloxy group acrylic acid, α-chloro- β-E- methoxy acrylic acids, β-diaminourea acrylic acid etc..

As dicarboxylic acids, can enumerate：Maleic acid, fumaric acid, itaconic acid etc..

As dicarboxylic acid derivatives, can enumerate：Citraconic acid, dimethyl maleic acid, phenyl maleic acid, chlorine Malaysia Acid, dichloromaleic acid, fluorine maleic acid, Methyl allyl ester, maleic acid diphenyl ester, maleic acid nonyl ester, maleic acid decyl ester, horse Carry out the maleates such as sour dodecyl ester, maleic acid stearyl, maleic acid fluoroalkyl ester.

As the acid anhydrides of dicarboxylic acids, can enumerate：Maleic anhydride, acrylic anhydride, methyl maleic anhydride, dimethyl Malaysia Acid anhydrides etc..

In addition, as the compound with carboxylic acid group, the acid anhydrides of carboxyl can also be generated using by hydrolysis.

It can additionally enumerate：Ethyl maleate, diethyl maleate, butyl maleate, dibutyl maleate, richness Horse acid mono ethyl ester, diethyl fumarate, monobutyl fumarate, dibutyl fumarate, Momo-cyclohexyl fumarte, the hexamethylene of fumaric acid two The unsaturated polynary carboxylic of the α such as ester, ethyl itaconate, diethyl itaconate, monobutyl itaconate, dibutyl itaconate, β-olefinic Acid monoester and diester.

As with sulfonic compound, can enumerate：Vinyl sulfonic acid, methyl ethylene sulfonic acid, (methyl) allyl Base sulfonic acid, styrene sulfonic acid, (methyl) acrylic acid -2- sulfonic acids, 2- acrylamide-2-methyl propane sulfonics, 3- allyloxys - 2- hydroxy-propanesulfonic acids etc..

It should be noted that in this manual, " (methyl) pi-allyl " refers to pi-allyl and/or methacrylic.

As the compound with phosphate, can enumerate：Phosphoric acid -2- (methyl) acryloyloxyethyl ester, phosphoric acid methyl - 2- (methyl) acryloyloxyethyl ester, ethyl-(methyl) acryloyloxyethyl ester etc..

It should be noted that in this manual, " (methyl) acryloyl group " refers to acryloyl group and/or methacryl Base.

As the compound with hydroxyl, can enumerate：The alkene such as (methyl) allyl alcohol, 3- butene-1-ols, 5- hexen-1-ols Belong to unsaturated alcohol；2-Hydroxy ethyl acrylate, 2-hydroxypropyl acrylate, methacrylic acid -2- hydroxy methacrylates, metering system Acid -2- hydroxy propyl esters, maleic acid two (2- hydroxyethyls) ester, maleic acid two (4- hydroxybutyls) ester, (the 2- hydroxyls third of itaconic acid two Base) ethylenically unsaturated carboxylic acids such as ester alkanol esters；Formula CH₂=CR¹-COO-(C_nH_2nO)_m- H (in formula, m represent 2~9 it is whole Number, n represent 2~4 integer, R¹Represent hydrogen or methyl) shown in PAG and the esters that are formed of (methyl) acrylic acid； 2- hydroxyethyls -2 '-(methyl) acryloxy phthalic acid ester, 2- hydroxyethyls -2 '-(methyl) acryloxy amber List (methyl) esters of acrylic acid of the dihydroxy ester of the dicarboxylic acids such as acid esters；2- hydroxyethyl vinyl ethers, 2- hydroxypropyl second The vinyl ethers such as alkene ether；(methyl) pi-allyl -2- hydroxyethyls ether, (methyl) pi-allyl -2- hydroxypropyls ether, (methyl) Pi-allyl -3- hydroxypropyls ether, (methyl) pi-allyl -2- hydroxybutyls ether, (methyl) pi-allyl -3- hydroxybutyls ether, (first Base) aklylene glycol such as pi-allyl -4- hydroxybutyls ether, (methyl) pi-allyl -6- hydroxyl hexyl ethers list (methyl) pi-allyl Ethers；The polyether polyols (methyl) such as diethylene glycol list (methyl) allyl ether, DPG list (methyl) allyl ether Monoallyl ethers；Glycerine list (methyl) allyl ether, (methyl) pi-allyl -2- chloro-3-hydroxyls propyl ether, (methyl) allyl The halogens of (poly-) aklylene glycol such as base -2- hydroxyl -3- chloropropyl ethers and list (methyl) allyl ether of hydroxyl substituent；Ding Zi List (methyl) allyl ether and its halogen substituents of the polyhydric phenols such as fragrant phenol, isoeugenol；(methyl) pi-allyl -2- hydroxyl second (methyl) allyl sulfide ethers of aklylene glycol such as base thioether, (methyl) pi-allyl -2- hydroxypropyl thioethers etc..

Here, there is the monomeric unit from 1- alkene, from the conjugation two that have passed through hydrogenation after polymerisation in polymer Y In the case of at least one of monomeric unit (that is, the conjugated diene monomeric unit of hydrogenation) of ene compound, in polymer Y Total ratio of the conjugated diene monomeric unit of monomeric unit and hydrogenation from 1- alkene is more excellent preferably more than 40 mass % It is selected in more than 50 mass %, further preferably more than 55 mass %, preferably below 90 mass %, more preferably in 80 mass % Hereinafter, further preferably below 75 mass %, particularly preferably below 70 mass %.Because the list from 1- alkene If the toatl proportion of body unit and the conjugated diene monomeric unit of hydrogenation more than 40 mass %, can fully improve slurry The dispersiveness and viscosity stability of composition, and can further improve the speed characteristic of lithium rechargeable battery；In addition, source If, can be true from the monomeric unit of 1- alkene and the toatl proportion of the conjugated diene monomeric unit hydrogenated below 90 mass % The viscosity stability of paste compound is protected, and the reduction of the cohesive force of the binding material comprising polymer Y can be suppressed.

It is derived from the monomeric unit for the conjugated diene compound not being hydrogenated after polymerisation in addition, having in polymer Y, is derived from The monomeric unit of (methyl) acrylate compounds or the monomer list from the compound that can polymerize with hydrophilic radical In the case of member, the toatl proportion of these monomeric units is preferably below 40 mass %, more preferably below 30 mass %, further It is preferred that below 20 mass %.If because the toatl proportion of these monomeric units below 40 mass %, can make While the cohesive force of binding material comprising polymer Y improves, suppress the reduction of the viscosity stability of paste compound.

It should be noted that in polymer Y with the monomeric unit from the compound that can polymerize with carboxylic acid group In the case of, its ratio is preferably below 10 mass %, more preferably below 5 mass %.Because from carboxylic acid group If the compound that can polymerize monomeric unit ratio below 10 mass %, can fully suppress paste compound Viscosity stability reduction.

Further, insoluble component amount (hereinafter also referred to " NMP insoluble components of the polymer Y in 1-METHYLPYRROLIDONE Amount ") preferably below 5 mass %.Because if NMP insoluble components amount can suppress slurry group below 5 mass % The generation of condensation product in compound, make the viscosity stability of paste compound good.

It should be noted that polymer Y NMP insoluble components amount can pass through list of the change for polymer Y polymerization The species of body, amount, polymerizing condition are adjusted, if for example, the ratio of the nitrile group-containing monomeric unit in increase polymer Y, NMP insoluble component amounts can then be reduced.Alternatively, it is also possible to by without using with the functional group that can be crosslinked after polymerisation Cross-linkable monomer reduce NMP insoluble component amounts.

In addition, the weight average molecular weight of the polymer Y polystyrene scaled value based on gel permeation chromatography is preferably 10000~700000,50000~500000, particularly preferably 100000~300000 are more preferably.If polymer Y weight Average molecular weight then can make positive pole have flexibility in above range, and then adjust the viscosity of paste compound to become easy.

Further, polymer Y glass transition temperature (Tg) is preferably below 25 DEG C, more preferably below 15 DEG C, spy Not preferably below 0 DEG C.Be not particularly limited for polymer Y Tg lower limit, but preferably more than -50 DEG C, more preferably More than -45 DEG C, particularly preferably more than -40 DEG C.By making polymer Y Tg to suppress in positive pole in above range Dry linting, raising in manufacturing process have used the cycle characteristics of the lithium rechargeable battery of the positive pole.It should be noted that polymerization Thing Y Tg can be adjusted by changing the species for the monomer polymerizeing.

In addition, above-mentioned polymer Y can be manufactured and used in the same manner as fluoropolymer X.

[polymer Z]

Polymer Z is poly- containing more than 50 mass % and below 90 mass % (methyl) alkyl acrylate monomer units Compound.Specifically, as polymer Z, more than a kind (methyl) alkyl acrylate monomer can be enumerated and can be with (the first Base) alkyl acrylate monomer copolymerization monomer copolymer.

It should be noted that polymer Z can also have fluorine-containing monomer unit, but fluorine-containing monomer unit in polymer Z For ratio generally below 40 mass %, preferably below 30 mass %, polymer Z is different from foregoing fluoropolymer X Polymer.

Here, as (methyl) alkyl acrylate monomer that can form (methyl) alkyl acrylate monomer units, The monomer same with (methyl) acrylate compounds that can be used in above-mentioned polymer Y polymerization can be used.Its In, it is viscous comprising polymer Z from improving as polymer Z (methyl) alkyl acrylate monomer, preferably alkyl acrylate From the viewpoint of the cohesive force for tying material, more preferably n-butyl acrylate, 2-EHA.

These (methyl) alkyl acrylate monomers can be used alone or be applied in combination two or more.

In addition, the ratio of (methyl) alkyl acrylate monomer units in polymer Z must more than 50 mass % and Below 90 mass %, preferably more than 55 mass %, preferably below 80 mass %, more preferably below 75 mass %, enter one Step is preferably below 70 mass %.Because (methyl) if the ratio of alkyl acrylate monomer units in 50 mass % More than, then it can fully improve the cohesive force of the binding material comprising polymer Z；In addition, (methyl) alkyl acrylate monomer If the ratio of unit can suppress the reduction of cycle characteristics below 90 mass %.

In addition, as the monomer that can be copolymerized with (methyl) alkyl acrylate monomer, it is not particularly limited, Ke Yilie Lift with the monomer (monomer containing acidic-group) of acidic-group, nitrile group-containing monomer, cross-linkable monomer, aromatic vinyl monomer, Ethylenically unsaturated carboxylic acids amide monomer etc..In addition, as can with (methyl) alkyl acrylate monomer be copolymerized monomer, preferably Use the monomer at least with acidic-group.That is, polymer Z preferably comprises the monomeric unit with acidic-group and (contains acidic groups Single group body unit).

It should be noted that these monomers can be used alone or be applied in combination it is two or more.

Here, as with acidic-group monomer, be not particularly limited, can use with carboxylic acid group monomer, With sulfonic monomer, the monomer with phosphate.It should be noted that from effectively taking into account the bonding that includes polymer Z From the viewpoint of the raising of the cohesive force of material and the raising of the cycle characteristics of lithium rechargeable battery, as with acidic-group Monomer, preferably using with carboxylic acid group monomer and with least one of sulfonic monomer, be more preferably applied in combination Monomer with carboxylic acid group and with sulfonic monomer.

As the monomer with carboxylic acid group, can use with it is above-mentioned can be used in the polymerizeing of polymer Y there is carboxylic The same monomer of the compound of acidic group.Wherein, from having used the paste compound of binding material comprising polymer Z to show From the viewpoint of good dispersiveness, as the monomer with carboxylic acid group, preferably using monocarboxylic acid, more preferably using propylene Acid, methacrylic acid, particularly preferably using methacrylic acid.

As with sulfonic monomer, can enumerate：Vinyl sulfonic acid, methyl ethylene sulfonic acid, styrene sulfonic acid, (methyl) propene sulfonic acid ((meta) acryl sulfonic acid), (methyl) acrylic acid -2- sulfonic acids, 2- acrylamides - 2- hydroxy-propanesulfonic acids, 2- acrylamide-2-methyl propane sulfonics etc..Wherein, from having used the binding material comprising polymer Z From the viewpoint of paste compound shows good dispersiveness, as with sulfonic monomer, preferably using 2- acrylamides- 2- hydroxy-propanesulfonic acids, 2- acrylamide-2-methyl propane sulfonics, more preferably using 2- acrylamide-2-methyl propane sulfonics.

As the monomer with phosphate, can enumerate：The chloro- 2- phosphoric acid propyl ester of (methyl) acrylic acid -3-, (methyl) propylene Acid -2- ethyls, 3- allyloxy -2- hydroxy propane phosphoric acid etc..

It should be noted that the acidic-group of the above-mentioned monomer with acidic-group can also be alkali metal salts or ammonium salt Form.

In addition, as nitrile group-containing monomer, can use and the above-mentioned nitrile group-containing list that can be used in the polymerizeing of polymer Y The same monomer of body.Wherein, the adaptation between material layer and collector is closed so as to improve the sight of the intensity of positive pole from raising positive pole Point sets out, as nitrile group-containing monomer, preferably acrylonitrile and methacrylonitrile, more preferably acrylonitrile.

Further, as cross-linkable monomer, can enumerate：Monomer containing epoxy radicals, contain carbon-to-carbon double bond and epoxy radicals Monomer, the monomer containing halogen atom and epoxy radicals, the monomer containing N- methylol amide bases, the list containing oxetanylmethoxy Body, containThe monomer of oxazoline base, the multi-functional monomer with more than 2 olefinic double bonds etc..

In addition, as aromatic vinyl monomer, can enumerate：Styrene, α-methylstyrene, to tert-butyl benzene second Alkene, vinyltoluene, chlorostyrene etc..

Further, as ethylenically unsaturated carboxylic acids amide monomer, can enumerate：Acrylamide, Methacrylamide, N, N- DMAA etc..

Here, in the case where polymer Z includes the monomeric unit with acidic-group, there is acidity in polymer Z The ratio of the monomeric unit of group is preferably more than 10 mass %, more preferably more than 13 mass %, further preferably in 15 matter More than % is measured, preferably below 30 mass %, more preferably below 27 mass %, further preferably below 25 mass %.This It is because if there is the ratio of the monomeric unit of acidic-group more than 10 mass %, can make viscous comprising polymer Z Tie the cohesive force of material and the cycle characteristics of lithium rechargeable battery fully improves；In addition, the monomer list with acidic-group If the ratio of member can suppress the generation of condensation product in paste compound, make paste compound below 30 mass % Viscosity stability is good.

It should be noted that comprising the monomeric unit with carboxylic acid group and with sulfonic monomer list in polymer Z In the case that both members are as the monomeric unit with acidic-group, by quality ratio, have carboxylic acid group's in polymer Z The ratio of monomeric unit relative to the ratio between ratio with sulfonic monomeric unit (monomeric unit with carboxylic acid group/with Sulfonic monomeric unit) it is preferably 99/1~85/15.

In addition, in the case where polymer Z has nitrile group-containing monomeric unit, nitrile group-containing monomeric unit in polymer Z Ratio is preferably more than 5 mass %, more preferably more than 10 mass %, further preferably more than 15 mass %, preferably 35 Below quality %, more preferably below 30 mass %, further preferably below 25 mass %.Because if nitrile group-containing The ratio of monomeric unit can then improve positive pole and close adaptation between material layer and collector, make gained positive pole in the scope Intensity improves.

Further, there is cross-linking monomer units, aromatic vinyl monomer unit or olefinic unsaturation carboxylic in polymer Z In the case of sour amide monomer units, the toatl proportion of these monomeric units is preferably below 30 mass %, more preferably in 25 matter Measure below %.Because if the toatl proportion of these monomeric units below 30 mass %, can be improved fully comprising poly- The cohesive force of compound Z binding material.

Here, insoluble component amounts (NMP insoluble component amount) of the polymer Z in 1-METHYLPYRROLIDONE is preferably 50 matter Below % is measured, more preferably below 30 mass %, more preferably below 20 mass %.Because NMP insoluble component amounts If below 50 mass %, the generation of the condensation product in paste compound can be suppressed, make the viscosity of paste compound steady It is qualitative good.

It should be noted that polymer Z NMP insoluble components amount can pass through list of the change for polymer Z polymerization The species of body, amount, polymerizing condition are adjusted, if for example, the ratio of the nitrile group-containing monomeric unit in increase polymer Z, NMP insoluble component amounts can then be reduced.

In addition, the weight average molecular weight of the polymer Z polystyrene scaled value based on gel permeation chromatography is preferably 10000~2000000,50000~1000000, particularly preferably 100000~500000 are more preferably.If polymer Z's Weight average molecular weight then can make positive pole have flexibility in above range, and then adjust the viscosity of paste compound to become to hold Easily.

Further, polymer Z glass transition temperature (Tg) is preferably below 50 DEG C, more preferably below 10 DEG C.It is right It is not particularly limited in polymer Z Tg lower limit, preferably more than -50 DEG C.By making polymer Z Tg in above-mentioned model Enclose, the dry linting in the manufacturing process of positive pole can be suppressed, improve the circulation spy for the lithium rechargeable battery for having used the positive pole Property.It should be noted that polymer Z Tg can be adjusted by changing the species for the monomer polymerizeing.

In addition, above-mentioned polymer Z can be manufactured and used in the same manner as fluoropolymer X, polymer Y.

[polymer X, Y, Z content]

Here, as it was previously stated, the present invention lithium ion secondary battery positive electrode with the bonding material used in paste compound In material, fluoropolymer X ratio must be more than 50 mass % and below 95 mass %, and fluoropolymer X ratio is preferred More than 60 mass %, more preferably more than 67 mass %, further preferably more than 70 mass %, preferably 90 mass % with Under, more preferably below 85 mass %.Because if fluoropolymer X ratio can carry more than 50 mass % The speed characteristic of high-lithium ion secondary cell；In addition, if fluoropolymer X ratio can then carry below 95 mass % The viscosity stability of high paste compound and the cycle characteristics of lithium rechargeable battery.

It should be noted that fluoropolymer X content is preferably to be relative to the mass ratio X/Y of polymer Y content 9.5/0.5~5.5/4.5 amount, the amount for more preferably making mass ratio X/Y be 9.5/0.5~6.5/3.5, more preferably makes Mass ratio X/Y is 9.5/0.5~7.5/2.5 amount.Because if X/Y in below 9.5/0.5, can be improved fully The dispersiveness and viscosity stability of paste compound, and it is possible to fully ensure the caking property of binding material, further improve The cycle characteristics of lithium rechargeable battery；In addition, if X/Y in more than 5.5/4.5, then can fully improve lithium ion secondary electricity The speed characteristic in pond.

In addition, fluoropolymer X content be preferably relative to polymer Z content mass ratio X/Z for 9.5/0.5~ 5.5/4.5 amount, the amount for more preferably making mass ratio X/Z be 9.5/0.5~6.5/3.5, more preferably makes mass ratio X/Z For 9.5/0.5~7.5/2.5 amount.Because if X/Z in below 9.5/0.5, can substantially ensure that binding material Caking property, further improve the cycle characteristics of lithium rechargeable battery；In addition, if X/Z in more than 5.5/4.5, then can fill Divide the speed characteristic for improving lithium rechargeable battery.

Further, polymer Y content is 1/9~9/1 preferably relative to the mass ratio Y/Z of polymer Z content Amount, the amount for more preferably making mass ratio Y/Z be 2/8~8/2, more preferably make the amount that mass ratio Y/Z is 3/7~7/3.It is poly- Compound Y it is poor in the case of, the hidden danger for causing the viscosity stability of paste compound to reduce be present, in containing for polymer Z In the case that amount is few, exist cause the caking property of binding material to reduce, the hidden danger of the cycle characteristics of lithium rechargeable battery decline.

Further, from the viscosity stability, the caking property of binding material, lithium ion two that paste compound is taken into account with high level From the viewpoint of the speed characteristic and cycle characteristics of primary cell, the ratio (X/Y/Z) of polymer X, Y, Z content is with quality criteria Meter is preferably 50~95/0.5~45/0.5~45, more preferably 60~90/0.4~36/0.4~36, more preferably 65 ~85/0.35~31.5/0.35~31.5.

[use level of binding material]

In addition, in the lithium ion secondary battery positive electrode paste compound of the present invention, relative to every 100 mass parts just Pole active material, the use level of binding material is preferably more than 0.5 mass parts, more preferably more than 1.0 mass parts, is preferably Below 2.5 mass parts, more preferably below 2.0 mass parts.If the use level of binding material is very few, presence can not ensure to starch The hidden danger of the viscosity stability of feed composition, and can not fully ensure cohesive force, possibly it can not fully improve lithium ion The cycle characteristics of secondary cell.On the other hand, if the use level of binding material is excessive, existing causes lithium rechargeable battery Speed characteristic decline hidden danger.

It is it should be noted that preferred relative to the positive active material of every 100 mass parts, fluoropolymer X use level More than 0.25 mass parts, more preferably more than 0.5 mass parts, more preferably more than 1.0 mass parts, preferably 2.475 Below mass parts, more preferably below 1.9 mass parts, more preferably below 1.25 mass parts.It is because if fluorine-containing Polymer X use level is very few, then the hidden danger for the speed characteristic that can not fully improve lithium rechargeable battery be present；In addition, such as Fruit fluoropolymer X use level is excessive, then the viscosity stability and lithium ion two that can not fully improve paste compound be present The hidden danger of the cycle characteristics of primary cell.

In addition, relative to the positive active material of every 100 mass parts, polymer Y use level is preferably 0.025 mass parts More than, more preferably more than 0.05 mass parts, more preferably more than 0.1 mass parts, preferably below 1.25 mass parts, more Preferably below 1.0 mass parts, more preferably below 0.25 mass parts.Because if polymer Y use level mistake It is few, then the hidden danger that can not fully ensure the viscosity stability of paste compound and the caking property of binding material be present；In addition, such as Fruit polymer Y use level is excessive, then existing causes the hidden danger that the speed characteristic of lithium rechargeable battery declines.

Further, relative to the positive active material of every 100 mass parts, polymer Z use level is preferably 0.025 mass More than part, more preferably more than 0.05 mass parts, more preferably more than 0.1 mass parts, preferably below 1.25 mass parts, More preferably below 1.0 mass parts, more preferably below 0.25 mass parts.Because if polymer Z use level It is very few, then it can not fully ensure the caking property of binding material, existing causes what the cycle characteristics of lithium rechargeable battery declined Hidden danger；In addition, if polymer Z use level is excessive, then presence causes the speed characteristic of lithium rechargeable battery to decline hidden Suffer from.

As the present invention lithium ion secondary battery positive electrode with the organic solvent used in paste compound, such as can be with Use the organic solvent with polarity that can dissolve or disperse above-mentioned fluoropolymer X, polymer Y and polymer Z.

Specifically, as organic solvent, can use：Acetonitrile, 1-METHYLPYRROLIDONE, acetylpyridine, cyclopentanone, DMAC N,N' dimethyl acetamide, dimethylformamide, dimethyl sulfoxide, NMF, MEK, furfural, ethylenediamine etc..These In, from viewpoints such as handling easiness, security, the easiness of synthesis, as organic solvent, most preferably N- crassitudes Ketone.

It should be noted that these organic solvents can be used alone, can also be used in mixed way two or more.

In the lithium ion secondary battery positive electrode paste compound of the present invention in addition to the above ingredients, can also contain for example Viscosity modifier, reinforcing material, antioxidant, there is the composition such as the electrolysis additive of function for suppressing electrolyte decomposition.This A little other compositions can use known material.

The lithium ion secondary battery positive electrode paste compound of the present invention can be by dissolving or disperseing above-mentioned each composition Prepared in the organic solvent as decentralized medium.

It should be noted that the mixing of above-mentioned each composition and organic solvent can use ball mill, sand mill, ball mill, Mixer known to pigment dispersion machine, grater, ultrasonic dispersing machine, homogenizer, planetary-type mixer, FILMIX etc..

(lithium ion secondary battery anode)

The lithium ion secondary battery anode of the present invention can use the lithium ion secondary battery positive electrode slurry of the present invention Composition manufactures.

In addition, the positive pole that the lithium ion secondary battery anode of the present invention possesses collector and formed on the current collector closes material Layer, positive active material, BET specific surface area 400m are comprised at least in positive pole closes material layer²/ more than g conductive material and Include fluoropolymer X, polymer Y and polymer Z binding material.Included just in material layer it should be noted that positive pole closes Pole active material, conductive material and binding material are included in the lithium ion secondary battery positive electrode paste compound of the present invention Material, above-mentioned each composition it is preferable exist than with the lithium ion secondary battery positive electrode paste compound of the present invention respectively into That divides is preferable in the presence of than identical.

In addition, it is the lithium ion using the invention described above that the positive pole of the lithium ion secondary battery anode of the present invention, which closes material layer, Anode of secondary battery paste compound and formed, therefore can fully improve the cycle characteristics and speed of lithium rechargeable battery Rate characteristic.

Here, be not particularly limited for the manufacture method of the lithium ion secondary battery anode of the present invention, including：Will The process (painting process) and will be coated on that above-mentioned lithium ion secondary battery positive electrode is coated on collector with paste compound Lithium ion secondary battery positive electrode on collector is dried with paste compound and forms positive pole on the current collector and close material layer Process (drying process).

It should be noted that the lithium ion secondary battery anode of the present invention can also be by by above-mentioned lithium ion secondary Anode is dried with paste compound to be granulated and compound particle is made and is formed on the current collector using the compound particle The method that positive pole closes material layer manufactures.

[painting process]

As the method being coated on above-mentioned lithium ion secondary battery positive electrode with paste compound on collector, without special Ground limits, and can use known method.Specifically, as coating method, can use scraper plate method, infusion process, inverse roller method, Direct roller method, intagliotype, extrusion molding, spread coating etc..At this point it is possible to lithium ion secondary battery positive electrode is only applied with paste compound The one side of collector is distributed in, two sides can also be coated on.The thickness of the slurry film on collector before being dried after coating can root The thickness of material layer is closed according to the positive pole being dried to obtain and is suitably set.

Here, the collector as lithium ion secondary battery positive electrode paste compound to be coated, can be used has conduction Property and with electrochemistry durability material.Specifically, as collector, the current collection made of aluminum or aluminum alloy can be used Body.At this point it is possible to which aluminium and aluminum alloy combination are used, diverse aluminum alloy combination can also be used.Due to aluminium and aluminium Alloy has stabilization in terms of heat resistance, electrochemistry, therefore is excellent current collector material.

[drying process]

As the method that the lithium ion secondary battery positive electrode on collector is dried with paste compound, without special Limit, known method can be used, such as can enumerate and utilize warm wind, hot blast, the drying of low wet wind, vacuum drying, utilization The seasoning of the irradiation of infrared ray, electron beam etc..Starched by the lithium ion secondary battery positive electrode dried in this wise on collector Feed composition, positive pole being formed on the current collector and closes material layer, the lithium ion of material layer is closed so as to obtain possessing collector and positive pole Anode of secondary cell.

It should be noted that material layer can also be closed to positive pole using moulding press or roll squeezer etc. and implemented after drying process Pressurized treatments.By pressurized treatments, the adaptation that positive pole closes material layer and collector can be improved.

Further, in the case where positive pole closes the polymer that material layer includes curability, preferably after positive pole closes the formation of material layer Solidify above-mentioned polymer.

(lithium rechargeable battery)

The lithium rechargeable battery of the present invention possesses positive pole, negative pole, electrolyte and dividing plate, and uses the lithium ion of the present invention Anode of secondary cell is as positive pole.And then the lithium ion two of lithium rechargeable battery of the invention due to having used the present invention Primary cell positive pole, therefore cycle characteristics and speed characteristic are excellent, are high performance.

As the negative pole of lithium rechargeable battery, it can use and be used as the known of lithium ion secondary battery cathode Negative pole.Specifically, as negative pole, negative pole can be used for example made of the thin plate of lithium metal or by negative electrode material together layer shape Into in the negative pole formed on collector.

It should be noted that as collector, can use by gold such as iron, copper, aluminium, nickel, stainless steel, titanium, tantalum, gold, platinum Belong to collector made of material.In addition, as negative electrode material together layer, can use comprising negative electrode active material and binding material Layer.Further, as binding material, it is not particularly limited, arbitrary known material can be used.

As electrolyte, the organic electrolyte that supporting electrolyte is dissolved in and formed in organic solvent can be generally used. As supporting electrolyte, such as lithium salts can be used.As lithium salts, for example,：LiPF₆、LiAsF₆、LiBF₄、 LiSbF₆、LiAlCl₄、LiClO₄、CF₃SO₃Li、C₄F₉SO₃Li、CF₃COOLi、(CF₃CO)₂NLi、(CF₃SO₂)₂NLi、 (C₂F₅SO₂) NLi etc..Wherein, due to being readily soluble in solvent and showing high degree of dissociation, therefore preferred LiPF₆、LiClO₄、 CF₃SO₃Li, particularly preferred LiPF₆.It should be noted that electrolyte can be used alone, can also be combined with arbitrary ratio Using two or more.Due to the supporting electrolyte for the using degree of dissociation higher then higher tendency of lithium ion conductivity generally be present, Therefore, lithium ion conductivity can be adjusted according to the species of supporting electrolyte.

As the organic solvent used in electrolyte, as long as the solvent that can dissolve supporting electrolyte does not limit especially then It is fixed, preferably using for example：Dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), the carbonates such as butylene carbonate (BC), methyl ethyl carbonate (MEC)；The esters such as gamma-butyrolacton, methyl formate；1,2- bis- The ethers such as Ethyl Methyl Ether, tetrahydrofuran；The sulfur-containing compound class such as sulfolane, dimethyl sulfoxide；Etc..These can also be used molten The mixed liquor of agent.Wherein, because dielectric constant is high, stable potential range is wide, therefore preferably uses carbonates, further excellent Choosing uses ethylene carbonate and the mixture of methyl ethyl carbonate.

It should be noted that the concentration of the electrolyte in electrolyte can be adjusted suitably, for example, it is preferable to be 0.5~15 Quality %, more preferably 2~13 mass %, more preferably 5~10 mass %.Alternatively, it is also possible to add in the electrolytic solution Known additive, such as fluoroethylene carbonate, ethyl-methyl sulfone etc..

As dividing plate, it is not particularly limited, can uses described in such as Japanese Unexamined Patent Publication 2012-204303 publications Dividing plate.Wherein, from the overall thickness of dividing plate can be thinned and thus improve the electrode active material in secondary cell ratio, From the aspect of improving the capacity of unit volume, preferably by TPO (polyethylene, polypropylene, polybutene, polychlorostyrene Ethene) resin formed micro-porous film.

For the lithium rechargeable battery of the present invention, it can be manufactured for example, by following methods：Across dividing plate overlapping just Pole and negative pole, and battery case is put into after optionally it is crimped according to cell shapes, bent etc., injected to battery case Electrolyte simultaneously seals., can also root for the generation for preventing the pressure rise of the inside of lithium rechargeable battery, crossing discharge and recharge etc. The overcurrent preventing elements such as fuse, PTC-element, expansion alloy, lead plate etc. are set according to needs.The shape of secondary cell can Arbitrary shape in thinking such as Coin shape, coin shape, piece type, cylinder type, square, platypelloid type.

Embodiment

Hereinafter, the present invention is specifically explained in conjunction with the embodiments, but the present invention is not limited to these embodiments.Need It is noted that in the following description, " % " and " part " of expression amount is then quality criteria unless otherwise specified.

In embodiment and comparative example, respectively using NMP insoluble component amount of the following methods to polymer, lithium ion secondary The dispersiveness and viscosity stability of anode paste compound, the peel strength of lithium ion secondary battery anode and The speed characteristic and cycle characteristics of lithium rechargeable battery are evaluated.

By the 1-METHYLPYRROLIDONE solution (solid component concentration of polymer：8%) so that dried thickness is 100 μm Mode inject teflon (registration mark) surface plate, made film.Obtained film is punched into diameter 16mm circle and surveyed Weight (being set to the weight " A ") is determined.Obtained film immersion will be punched in 1-METHYLPYRROLIDONE (NMP) 20ml, in 60 DEG C preserve 72 hours.Then, nmp solution (by the weight of sieve filtering before be " B ") of the filter impregnated of film is sieved through using 80 purposes, And make its drying.Then, the weight (being set to the weight " C ") of dried sieve is determined.Polymer has been obtained by these values NMP insoluble components amount (={ (C-B)/A } × 100%).

For the lithium ion secondary battery positive electrode paste compound of preparation, adjustment solid component concentration, determining The viscosity of paste compound reaches target viscosities (5000 ± 200mPas) at 25 DEG C of temperature.Then, measure reaches target viscosities When paste compound solid component concentration, and evaluated according to following benchmark.It is believed that reach target viscosities When solid component concentration it is higher, then the effect using each composition of lesser amount of dispersion medium is higher, paste compound Dispersiveness is higher.

A：Solid component concentration is more than 80 mass %

B：Solid component concentration is 75 mass % less than 80 mass %

C：Solid component concentration is less than 75 mass %

For the lithium ion secondary battery positive electrode paste compound of preparation, using Brookfield viscometer determine 25 DEG C of temperature, Viscosities il 0 under rotating speed 60rpm.The paste compound that have passed through viscosimetric analysis has been carried out 24 hours using planetary-type mixer Stir (rotating speed：60rpm).For the paste compound after stirring, 25 DEG C of temperature, rotating speed are determined again using Brookfield viscometer Viscosities il 1 under 60rpm.And then viscosity conservation rate Δ η=(η 0 of η 1/) × 100% is calculated, and according to following benchmark evaluation The viscosity stability of paste compound.The value of viscosity conservation rate is bigger, then it represents that the viscosity stability of paste compound is more excellent.

A：Viscosity conservation rate is more than 80%

B：Viscosity conservation rate is 70% less than 80%

C：Viscosity conservation rate is less than 70%

The positive pole that forms positive pole conjunction material layer and have passed through after roll-in is cut into wide 1.0cm × long 10cm rectangle as examination Test piece.Then, in the surface mount cellophane tape of the positive pole conjunction material layer side of test film.Now, cellophane tape uses JIS Z1522 Specified in material.Then, in the state of cellophane tape is fixed on into testing stand, with the speed of 50mm/ minutes by test film Torn from a side towards another side, determine stress now.Measure is carried out 10 times, obtains the average value of stress, and by its As peel strength (N/m), evaluated according to following benchmark.Peel strength is bigger, then it represents that it is relative that positive pole closes material layer It is more excellent in the adaptation of collector.

A：Peel strength is more than 30N/m

B：Peel strength is 10N/m less than 30N/m

C：Peel strength is less than 10N/m

To 10 batteries of lithium rechargeable battery of making, carry out respectively under conditions of 25 DEG C of temperature with 0.2C perseverance Constant-current charge is discharged to 3.0V charge and discharge cycles and under conditions of 25 DEG C of temperature to 4.2V and with 0.2C constant current 3.0V charge and discharge cycles are discharged to 0.2C constant current charge to 4.2V and with 1.0C constant current.With percentage Discharge capacity (average value) when form calculus goes out 1.0C relative to the discharge capacity (average value) during 0.2C ratio (= (discharge capacity during discharge capacity/0.2C during 1.0C) × 100%), as charge-discharge velocity characteristic, and according to following benchmark It has rated speed characteristic.The value of charge-discharge velocity characteristic is bigger, represents that internal resistance is smaller, can more realize high speed discharge and recharge.

A：Charge-discharge velocity characteristic is more than 80%

B：Charge-discharge velocity characteristic is 75% less than 80%

C：Charge-discharge velocity characteristic is 70% less than 75%

D：Charge-discharge velocity characteristic is less than 70%

For 10 batteries of lithium rechargeable battery of making, under conditions of 25 DEG C of temperature, electricity will be charged to 600mA Cell voltage, which reaches 4.4V and is discharged to cell voltage with 600mA and reaches 3V operation, to be repeated 100 times.And then obtain The discharge capacity (average value) of 100 times relative to the discharge capacity (average value) of the 1st time ratio (charge/discharge capacity conservation rate= (discharge capacity of discharge capacity/1st time of the 100th time) × 100%), and evaluated according to following benchmark.Discharge and recharge The value of capability retention is bigger, represents that cycle characteristics is more excellent.

A：Charge/discharge capacity conservation rate is more than 80%

B：Charge/discharge capacity conservation rate is 70% less than 80%

C：Charge/discharge capacity conservation rate is 60% less than 70%

D：Charge/discharge capacity conservation rate is less than 60%

(embodiment 1)

Prepare to make Kynoar (fluoropolymer X1) be dissolved in the solution that NMP is formed.

240 parts of ion exchange water, the acrylonitrile (AN) 25 as nitrile group-containing monomer are added into the autoclave of belt stirrer Mass parts, as can be with the mass parts of butadiene (BD) 60 and the matter of butyl acrylate (BA) 15 of the monomer of nitrile group-containing monomer copolymerization Measure part, 0.3 part of the potassium peroxydisulfate as polymerization initiator, 1.6 parts of the NaLS as emulsifying agent, as molecular weight adjust 0.05 part of whole dose of tert-dodecylmercaotan, after being sufficiently stirred and replacing inside using nitrogen, heated 3 hours, 80 DEG C in 70 DEG C Heat 2 hours and polymerize, obtained the aqueous dispersions of polymer.Wherein, the polymerization conversion obtained by solid component concentration Rate is 96%.

Ion exchange water will be added relative to resulting polymers and solid component concentration has been adjusted to the 400 of 12 mass % Milliliter solution is put into 1 liter of autoclave of belt stirrer, is led to nitrogen 10 minutes by after the dissolved oxygen removing in solution, is made For catalyst for hydrogenation, acid chloride 75mg is dissolved in the water 180ml that with the addition of that molal quantity is Pd 4 times of nitric acid, and add It is added in autoclave.Using hydrogen to being replaced twice in system after, using pressurized with hydrogen in the state of 3MPa by height Content in pressure kettle is heated up to 50 DEG C, has carried out 6 hours hydrogenation reactions (being referred to as " first stage hydrogenation reaction ").

Next, making autoclave recover to atmospheric pressure, catalyst for hydrogenation is further used as and acid chloride 25mg is molten Xie Yu with the addition of the water 60ml that molal quantity is Pd 4 times of nitric acid, and be added in autoclave.Using hydrogen to being carried out in system After replacing twice, the content in autoclave is heated up to 50 DEG C in the state of using pressurized with hydrogen to 3MPa, it is small to have carried out 6 When hydrogenation reaction (be referred to as " second stage hydrogenation reaction ").

Then, content is recovered to normal temperature, make after turning into nitrogen atmosphere in system, carried out using Rotary Evaporators dense Contracting reaches 40% up to solid component concentration, has obtained polymer Y1 aqueous dispersions.In addition, dissipated to polymer Y1 moisture 320 parts of NMP is added in 100 parts of liquid, evaporates the water under reduced pressure, has obtained polymer Y1 nmp solution.

It should be noted that polymer Y1 NMP insoluble components amount is 2 mass %.

The mass parts of ion exchange water 164 are added into the autoclave of belt stirrer, as (methyl) alkyl acrylate list The mass parts of 2-EHA (2EHA) 59.5 of body, the methacrylic acid (MAA) 20 as the monomer with carboxylic acid group Mass parts, the mass parts of acrylonitrile (AN) 20 as nitrile group-containing monomer, as the 2- acrylamides -2- with sulfonic monomer The mass parts of methyl propane sulfonic acid (AMPS) 0.5,0.3 part of the potassium peroxydisulfate as polymerization initiator, the lauryl sulphur as emulsifying agent Sour 1.6 parts of sodium, after being sufficiently stirred, heated in 70 DEG C 3 hours, 80 DEG C and heat 2 hours and polymerize, obtained polymer Z1 Aqueous dispersions.Wherein, the polymerisation conversion obtained by solid component concentration is 96%.Next, to 100 parts of the aqueous dispersions Middle 500 parts of 1-METHYLPYRROLIDONE of addition, make water and whole residual monomers and 81 parts of steamings of 1-METHYLPYRROLIDONE under reduced pressure Hair, the concentration for having obtained polymer Z1 is 8 mass % nmp solution.

It should be noted that polymer Z1 NMP insoluble components amount is 10 mass %.

Using as the cobalt acid lithium LCO (LiCoO of 12 μm of the volume average particle size of positive active material₂) 100 parts, as conduction Ketjen black (manufacture of Lion companies, EC300J, special Audit For Process carbon dust shape product, number average bead diameter 40nm, the BET specific surface area of material 800m²/ g) 1.5 parts, be calculated as with solid constituent a great deal of 1.2 parts fluoropolymer X1 nmp solution, suitable with solid constituent The NMP for the polymer Z1 for measure the nmp solution for the polymer Y1 for being calculated as 0.15 part, 0.15 part being calculated as with solid constituent a great deal of is molten Liquid and appropriate NMP, are stirred using planetary-type mixer, so that its viscosity under 25 DEG C of temperature, rotating speed 60rpm (being determined using Brookfield viscometer) is prepared for positive pole paste compound for 5000 ± 200mPas mode.Obtained slurry group The solid component concentration of compound is 81 mass %, viscosity 5100mPas.

And then the dispersiveness and viscosity stability of the paste compound to obtaining are evaluated.As a result it is as shown in table 1.

As collector, the aluminium foil of 15 μm of thickness is prepared.Then, so that dried coating weight is 20mg/cm²Side Lithium ion secondary battery positive electrode is coated on the two sides of aluminium foil by formula with paste compound, and dries in 60 DEG C 20 minutes, in 120 DEG C Dry 20 minutes.Afterwards, carry out heating for 2 hours in 150 DEG C, obtained positive original film.The positive original film is utilized into roll-in Machine is rolled, and it is 3.7g/cm to have made by density³Positive pole close the sheet-like anode that material layer and aluminium foil are formed.And then by sheet Positive pole is cut into wide 4.8mm, long 50cm, as lithium ion secondary battery anode.

Then, it have rated the peel strength of gained positive pole.As a result it is as shown in table 1.

Using as the spherical Delanium (volume average particle size of negative electrode active material:12 μm) 90 parts and SiO_X(volume is put down Equal particle diameter:10 μm) 10 parts of mixture, the styrene butadiene that 1 part is calculated as with solid constituent a great deal of as binding material The aqueous dispersions of polymer, 1 part of the carboxymethyl cellulose as thickener and pass through planet as the appropriate water of decentralized medium Formula mixer is stirred, and is prepared for lithium ion secondary battery negative pole paste compound.

Then, as collector, the copper foil of 15 μm of thickness has been prepared.Then, so that dried coating weight is 10mg/ cm²Mode above-mentioned lithium ion secondary battery negative pole is coated on to the two sides of copper foil with paste compound, and dry 20 in 60 DEG C Minute, in 120 DEG C dry 20 minutes.Afterwards, carry out heating for 2 hours in 150 DEG C, obtained negative original film.By the negative pole Former film is rolled with roll squeezer, and it is 1.8g/cm to have made by density³Negative electrode material together layer and copper foil form sheet-like cathode. Then, sheet-like cathode is cut into wide 5.0mm, long 52cm, as lithium ion secondary battery cathode.

Using diameter 20mm core, by the lithium ion secondary battery anode of making and lithium ion secondary battery cathode every Dividing plate (the polypropylene microporous film of 20 μm of thickness) to be wound, obtain coiling body.By obtained coiling body from a side Reach 4.5mm to the speed compression of 10mm/ seconds to thickness.It should be noted that the coiling body after compression is to overlook ellipse, The ratio of its major diameter and minor axis (major diameter/minor axis) is 7.7.

In addition, prepare nonaqueous electrolytic solution (composition：Concentration 1.0M LiPF₆(solvent is in ethylene carbonate/carbonic acid to solution The in the mixed solvent of methyl ethyl ester=3/7 (mass ratio) adds the mixture that 5 mass % fluoroethylene carbonates form, as addition Agent, with the addition of 2 volume % vinylene carbonates)).

Then, the coiling body after compression is contained in given aluminium laminate shell together with 3.2g nonaqueous electrolytic solution In vivo.Then, by the nickel down-lead for being connected to lithium ion secondary battery cathode and lithium rechargeable battery has been connected to just The aluminum lead of pole is connected to given position, and the opening portion of housing is sealed using heat afterwards, lithium ion secondary has been made Battery.The lithium rechargeable battery is width 35mm, height 48mm, thickness 5mm pouch-shaped, and the nominal capacity of battery is 700mAh.The evaluation of speed characteristic and cycle characteristics has been carried out for gained lithium rechargeable battery.As a result it is shown in table 1.

(embodiment 2~3)

The use level of conductive material during except lithium ion secondary battery positive electrode being prepared with paste compound changes respectively Outside 1.0 parts, 2.0 parts, lithium ion secondary battery positive electrode paste compound, lithium ion have been manufactured similarly to Example 1 Anode of secondary cell, lithium ion secondary battery cathode and lithium rechargeable battery, and evaluated.As a result such as the institute of table 1 Show.

(embodiment 4~5)

The conductive material used during except lithium ion secondary battery positive electrode being prepared with paste compound is changed to second respectively Acetylene black (Denki Kagaku Kogyo kabushiki's manufacture, AB35, DENKA BLACK powderies product, number average bead diameter 35nm, BET specific surface area 68m²/ g) and Ketjen black (manufacture of Lion companies, EC300J, special Audit For Process carbon dust shape product, number average bead diameter 40nm, BET compare surface Product 800m²/ g) mixture (BET specific surface area 600m²/ g), Ketjen black (manufacture of Lion companies, EC600J, number average bead diameter 40nm, BET specific surface area 1270m²/ g) outside, lithium ion secondary battery positive electrode slurry group has been manufactured similarly to Example 1 Compound, lithium ion secondary battery anode, lithium ion secondary battery cathode and lithium rechargeable battery, and evaluated. As a result it is as shown in table 1.

(embodiment 6~8)

The amount of the polymer used during except lithium ion secondary battery positive electrode being prepared with paste compound is entered as shown in table 1 Outside row change, lithium ion secondary battery positive electrode paste compound, lithium rechargeable battery have been made similarly to Example 1 With positive pole, lithium ion secondary battery cathode and lithium rechargeable battery, and evaluated.As a result it is as shown in table 1.

(embodiment 9)

In addition to having used the polymer Y2 being prepared as described below instead of polymer Y1, manufacture similarly to Example 1 Lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode and Lithium rechargeable battery, evaluated.As a result it is as shown in table 1.

Except the amount for making acrylonitrile (AN) is 15 mass parts, the amount of butadiene (BD) is 75 mass parts, butyl acrylate (BA) amount is outside 10 mass parts, and polymer Y2 has been prepared as with polymer Y1.

It should be noted that polymer Y2 NMP insoluble components amount is 15 mass %.

(embodiment 10)

In addition to having used the polymer Y3 being prepared as described below instead of polymer Y1, manufacture similarly to Example 1 Lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode and Lithium rechargeable battery, evaluated.As a result it is as shown in table 1.

Except the amount for making acrylonitrile (AN) is 30 mass parts, the amount of butadiene (BD) is 50 mass parts, butyl acrylate (BA) amount is outside 20 mass parts, and polymer Y3 has been prepared as with polymer Y1.

It should be noted that polymer Y3 NMP insoluble components amount is 1 mass %.

(embodiment 11)

In addition to having used the polymer Z2 being prepared as described below instead of polymer Z1, manufacture similarly to Example 1 Lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode and Lithium rechargeable battery, evaluated.As a result it is as shown in table 1.

Except the amount for making 2-EHA (2EHA) is 54.5 mass parts, the amount of methacrylic acid (MAA) is 25 Outside mass parts, polymer Z2 has been prepared as with polymer Z1.

It should be noted that polymer Z2 NMP insoluble components amount is 4 mass %.

(embodiment 12)

In addition to having used the polymer Z3 being prepared as described below instead of polymer Z1, manufacture similarly to Example 1 Lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode and Lithium rechargeable battery, evaluated.As a result it is as shown in table 1.

Except the amount for making 2-EHA (2EHA) is 69.5 mass parts, the amount of methacrylic acid (MAA) is 15 Mass parts, the amount of acrylonitrile (AN) are outside 15 mass parts, and polymer Z3 has been prepared as with polymer Z1.

It should be noted that polymer Z3 NMP insoluble components amount is 13 mass %.

(embodiment 13)

In addition to having used the polymer Z4 being prepared as described below instead of polymer Z1, manufacture similarly to Example 1 Lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode and Lithium rechargeable battery, evaluated.As a result it is as shown in table 1.

Except the amount for making 2-EHA (2EHA) is 79.5 mass parts, the amount of methacrylic acid (MAA) is 10 Mass parts, the amount of acrylonitrile (AN) are outside 10 mass parts, and polymer Z4 has been prepared as with polymer Z1.

It should be noted that polymer Z4 NMP insoluble components amount is 20 mass %.

(comparative example 1)

The conductive material used during except lithium ion secondary battery positive electrode being prepared with paste compound is changed to acetylene black (Denki Kagaku Kogyo kabushiki's manufacture, AB35, DENKA BLACK powderies product, number average bead diameter 35nm, BET specific surface area 68m²/g) With Ketjen black (manufacture of Lion companies, EC300J, special Audit For Process carbon dust shape product, number average bead diameter 40nm, BET specific surface area 800m²/ g) mixture (BET specific surface area 350m²/ g) outside, lithium rechargeable battery is being manufactured similarly to Example 1 just Pole paste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode and lithium rechargeable battery, go forward side by side Evaluation is gone.As a result it is as shown in table 2.

(comparative example 2~3)

The amount of the polymer used during except lithium ion secondary battery positive electrode being prepared with paste compound is entered as shown in table 2 Outside row change, lithium ion secondary battery positive electrode paste compound, lithium rechargeable battery have been manufactured similarly to Example 1 With positive pole, lithium ion secondary battery cathode and lithium rechargeable battery, and evaluated.As a result it is as shown in table 2.

(comparative example 4)

In addition to replacing polymer Y1 and having used the polymer Y4 being prepared as described below, make similarly to Example 1 Lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode are made And lithium rechargeable battery, and evaluated.As a result it is as shown in table 2.

Except the amount for making acrylonitrile (AN) is 5 mass parts, the amount of butadiene (BD) is 85 mass parts, butyl acrylate (BA) Amount be 10 mass parts outside, be prepared as polymer Y4 with polymer Y1.

It should be noted that polymer Y4 NMP insoluble components amount is 55 mass %.

(comparative example 5)

In addition to replacing polymer Y1 and having used the polymer Y5 being prepared as described below, make similarly to Example 1 Lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode are made And lithium rechargeable battery, and evaluated.As a result it is as shown in table 2.

Except the amount for making acrylonitrile (AN) is 55 mass parts, the amount of butadiene (BD) is 35 mass parts, butyl acrylate (BA) amount is outside 10 mass parts, and polymer Y5 has been prepared as with polymer Y1.

It should be noted that polymer Y5 NMP insoluble components amount is 0.5 mass %.

(comparative example 6)

In addition to replacing polymer Z1 and having used the polymer Z5 being prepared as described below, make similarly to Example 1 Lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode are made And lithium rechargeable battery, and evaluated.As a result it is as shown in table 2.

Except the amount for making 2-EHA (2EHA) is 44.5 mass parts, the amount of methacrylic acid (MAA) is 35 Outside mass parts, polymer Z5 has been prepared as with polymer Z1.

It should be noted that polymer Z5 NMP insoluble components amount is 2 mass %.

(comparative example 7)

In addition to replacing polymer Z1 and having used the polymer Z6 being prepared as described below, make similarly to Example 1 Lithium ion secondary battery positive electrode paste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode are made And lithium rechargeable battery, and evaluated.As a result it is as shown in table 2.

Except the amount for making 2-EHA (2EHA) is 94.5 mass parts, the amount of methacrylic acid (MAA) is 5 matter Measure outside part and unmated acrylonitrile (AN), polymer Z6 has been prepared as with polymer Z1.

It should be noted that polymer Z6 NMP insoluble components amount is 25 mass %.

It can be seen from table 1 and table 2, the paste compound of embodiment 1~13 compared with the paste compound of comparative example 3~6, Both dispersiveness and viscosity stability are excellent.In addition we know, the positive pole phase of the positive pole of embodiment 1~13 and comparative example 3,4,6,7 Than peel strength is excellent.In addition understand, the lithium rechargeable battery of embodiment 1~13 and the lithium ion secondary of comparative example 1~7 Battery is compared, and both cycle characteristics and speed characteristic are excellent.

Especially,, can be with high level by adjusting the use level of conductive material it can be seen from the embodiment 1~3 of table 1 Take into account the dispersiveness and the cycle characteristics and speed characteristic of viscosity stability and lithium rechargeable battery of paste compound.

, can be with by adjusting the BET specific surface area of conductive material in addition, it can be seen from the embodiment 1 and 4~5 of table 1 High level takes into account dispersiveness and the cycle characteristics and speed of viscosity stability and the lithium rechargeable battery spy of paste compound Property.

Further,, can be with Gao Shui by adjusting the mixing ratio of polymer it can be seen from the embodiment 1 and 6~8 of table 1 The flat dispersiveness and the cycle characteristics and speed characteristic of viscosity stability and lithium rechargeable battery for taking into account paste compound.

In addition, it can be seen from the embodiment 1 and 9~13 of table 1, can be simultaneous with high level by adjusting the composition of polymer Care for the dispersiveness and the cycle characteristics and speed characteristic of viscosity stability and lithium rechargeable battery of paste compound.

Industrial applicibility

According to the present invention it is possible to it is special further to improve the performance of lithium rechargeable battery, especially cycle characteristics and speed Property, and can provide viscosity stability excellent lithium ion secondary battery positive electrode paste compound.In addition, according to this hair It is bright, can provide the lithium of performance, especially cycle characteristics and the speed characteristic that can further improve lithium rechargeable battery from Sub- anode of secondary cell.In addition, according to the present invention it is possible to provide high performance lithium rechargeable battery.

Claims

1. a kind of lithium ion secondary battery positive electrode paste compound, it is included：Positive active material, conductive material, bond material Material and organic solvent,

The BET specific surface area of the conductive material is 400m²/ more than g,

The binding material includes：

(1) fluoropolymer X,

(2) polymer Y, its contain more than 10 mass % and below 50 mass % nitrile group-containing monomeric unit and

(3) polymer Z, its contain more than 50 mass % and below 90 mass % alkyl methacrylate monomer unit and/ Or alkyl acrylate monomer units,

Fluoropolymer X ratio described in the binding material is more than 50 mass % and below 95 mass %.

2. lithium ion secondary battery positive electrode paste compound according to claim 1, wherein, the fluoropolymer X Content 9.5/0.5~5.5/4.5 is calculated as with quality criteria relative to the ratio (X/Y) of the content of the polymer Y.

3. lithium ion secondary battery positive electrode paste compound according to claim 1 or 2, wherein, the fluoropolymer Thing X content is calculated as 9.5/0.5~5.5/4.5 relative to the ratio (X/Z) of the content of the polymer Z with quality criteria.

4. lithium ion secondary battery positive electrode paste compound according to claim 1 or 2, wherein, the polymer Z is also Contain monomeric unit containing acidic-group.

5. lithium ion secondary battery positive electrode paste compound according to claim 4, wherein, the polymer Z contains More than 10 mass % and below 30 mass the % monomeric unit containing acidic-group.

6. lithium ion secondary battery positive electrode paste compound according to claim 1 or 2, wherein, the polymer Y exists Insoluble component amount in 1-METHYLPYRROLIDONE is below 5 mass %.

7. lithium ion secondary battery positive electrode paste compound according to claim 1 or 2, wherein, the polymer Z exists Insoluble component amount in 1-METHYLPYRROLIDONE is below 50 mass %.

8. a kind of lithium ion secondary battery anode, it possesses any one of usage right requirement 1~7 on the current collector The positive pole that lithium ion secondary battery positive electrode is formed with paste compound closes material layer.

9. a kind of lithium rechargeable battery, it is included：

Lithium ion secondary battery anode described in claim 8,

Negative pole,

Electrolyte and

Dividing plate.