CN105612641A

CN105612641A - Slurry composition for positive electrode for lithium ion rechargeable battery, positive electrode for lithium ion rechargeable battery, and lithium ion rechargeable battery

Info

Publication number: CN105612641A
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: 2016-05-25
Anticipated expiration: 2034-10-29
Also published as: CN105612641B; KR20160082503A; JP6369473B2; JPWO2015064099A1; KR102264698B1; WO2015064099A1

Abstract

Provided is a slurry composition for positive electrode for lithium ion rechargeable battery, which has excellent viscostability, and with which it is possible to improve the performance of a lithium ion rechargeable-battery, in particular the cycle characteristics and the rate characteristics. This slurry for positive electrode for lithium ion rechargeable battery contains a positive electrode active material, an electro-conductive material, a binder and an organic solvent. The BET specific surface area of the electro-conductive material is at least 400 m2/g, the binder contains (1) a fluorine-containing polymer (X), (2) a polymer (Y) containing 10-50 mass% of nitrile group-containing monomer units, and (3) a polymer (Z) containing 50-90 mass% of (meth)acrylic acid alkyl ester monomer units, and the fluorine-containing polymer (X) content in the binder is 50-95 mass %.

Description

Paste compound, lithium ion secondary battery anode and lithium rechargeable battery for lithium ion secondary battery positive electrode

Technical field

The present invention relates to paste compound for lithium ion secondary battery positive electrode, lithium ion secondary battery anodeAnd lithium rechargeable battery.

Background technology

That lithium rechargeable battery has is small-sized, lightweight and energy density is high and can repeat to discharge and recharge thisThe characteristic of sample, has been used to extensive use. Therefore, in recent years, in order to realize lithium rechargeable batteryFurther high performance, is studied for the improvement of the battery components such as electrode. Specifically, existIn the high performance of lithium rechargeable battery, owing to must improving battery capacity, cycle characteristics and speed spyProperty etc., therefore study by the battery components such as electrode being improved to improve battery capacity, circulation spyProperty and speed characteristic.

At this, the positive pole that lithium rechargeable battery is used conventionally possesses collector body and is formed on the electricity on collector bodyThe utmost point closes material layer (positive pole closes material layer). In addition, this positive pole close material layer for example can be by being coated with and making on collector bodyPositive active material, conductive material, binding material etc. are dispersed or dissolved in the slurry group that decentralized medium formsCompound also makes it dry and form.

In addition, as a rule, positive pole close the amount of the positive active material in material layer and kind can affect lithium fromThe battery capacity of sub-secondary cell, amount and proterties that positive pole closes the conductive material in material layer can affect speed spyProperty, positive pole closes the amount of the binding material in material layer and cohesive force can affect the circulation spy of lithium rechargeable batteryProperty, speed characteristic.

For this reason, in the prior art, proposed cohesive force by making binding material improve, realize withA small amount of binding material is guaranteed the cycle characteristics of lithium rechargeable battery, positive pole is closed in material layer anodalThe increase of the amount of active material and conductive material becomes possibility, and then improves battery capacity and speed characteristic.

Specifically, for example, in patent documentation 1, following scheme has been proposed: by being just used to formThe utmost point closes the lithium ion secondary battery positive electrode of material layer with using by fluoropolymer with at N-in paste compoundTwo kinds of different binding materials that fluoropolymer does not form of insoluble one-tenth component in methyl pyrrolidone, fromAnd guarantee close-burning realize simultaneously anodal close material layer in the amount of positive active material and conductive materialIncrease. And then, in patent documentation 1, by using to contain two kinds of not fluoropolymers to certainty ratioWith the lithium ion secondary battery positive electrode paste compound of fluoropolymer as binding material, improve lithiumBattery capacity, cycle characteristics and the speed characteristic of ion secondary battery.

In addition, for example, in patent documentation 2, following scheme has been proposed: by lithium rechargeable batteryAnodal with using by the spy with 1-olefin unit and (methyl) acrylic acid alkyl ester units in paste compoundPolymer, fluoropolymer and the insoluble one-tenth component in 1-METHYLPYRROLIDONE of fixed composition areThe binding material that polymer more than 50 quality % forms, thus guaranteeing the close-burning positive pole of simultaneously realizingClose the increase of the amount of positive active material and conductive material in material layer. And then, in patent documentation 2, logicalCross and use the polymerization that comprises the specific composition with 1-olefin unit and (methyl) acrylic acid alkyl ester unitsThing, fluoropolymer and the insoluble one-tenth component in 1-METHYLPYRROLIDONE are more than 50 quality %Polymer as the lithium ion secondary battery positive electrode paste compound of binding material, improved lithium ionBattery capacity, cycle characteristics and the speed characteristic of secondary cell.

Prior art document

Patent documentation

Patent documentation 1: TOHKEMY 2003-223895 communique

Patent documentation 2: TOHKEMY 2004-172017 communique

Summary of the invention

The problem that invention will solve

But, for the lithium that uses above-mentioned traditional lithium ion secondary battery positive electrode paste compound to makeIon secondary battery, is further improving battery performance, especially cycle characteristics and speed characteristicAlso there is room for improvement in aspect.

In addition, in recent years, propose the BET specific area by improving conductive material, improvedWhen speed characteristic, reduce the technology of the use amount of conductive material. But the inventor etc. are through further investigationRear discovery, has just been used above-mentioned traditional lithium ion secondary battery positive electrode slurry of above-mentioned binding material to combineThing, if for improve lithium rechargeable battery speed characteristic and by the BET ratio of conductive materialSurface area is brought up to for example 400m²More than/g, can cause conductive material and become easy cohesion and cause slurryThe problem that the viscosity stability of composition declines, the keeping quality of paste compound reduces, and for current collectionThe coating of body can through time the problem that changes.

Based on this, the object of the present invention is to provide and can make the performance of lithium rechargeable battery, especiallyCycle characteristics and speed characteristic further improve and the lithium rechargeable battery of viscosity stability excellence justUtmost point paste compound.

In addition, the object of the present invention is to provide can make lithium rechargeable battery performance, especially followThe lithium ion secondary battery anode that ring property and speed characteristic further improve.

Further, the object of the present invention is to provide the high property that has used this lithium ion secondary battery anodeThe lithium rechargeable battery of energy.

The method of dealing with problems

The inventor etc. have carried out in depth research to solve above-mentioned problem as object. And then, the present inventionThe discoveries such as people, comprise and have the conductive material of given BET specific area and with given ratio bagCombine with slurry as the lithium ion secondary battery positive electrode of binding material containing specific polymer X, Y, ZThing, viscosity stability excellence and can improve fully cycle characteristics and the speed of lithium rechargeable batteryRate characteristic, thus the present invention completed.

That is, the present invention is effectively to solve above-mentioned problem as object, and lithium rechargeable battery of the present invention justThe utmost point is characterised in that with paste compound, comprises positive active material, conductive material, binding material and hasMachine solvent, the BET specific area of described conductive material is 400m²More than/g, described binding material bagContain the above following nitrile group-containing monomeric unit of true 50 quality % of 10 quality % containing (1) fluoropolymer X, (2)Polymer Y, (3) contain above and following (methyl) alkyl acrylate list of 90 quality % of 50 quality %The polymer Z of body unit, the ratio of fluoropolymer X described in described binding material is 50 quality %Above and below 95 quality %. Used in this wise given polymer X, Y, Z as binding material,And the ratio of the fluoropolymer X in binding material is more than 50 quality % and below 95 quality %Lithium ion secondary battery positive electrode paste compound, viscosity stability excellence and can improving fullyThe cycle characteristics of lithium rechargeable battery and speed characteristic.

It should be noted that, in the present invention, described " BET specific area " refers to based on nitrogen and adsorbsThe BET specific area of method, can measure according to ASTMD3037-81.

At this, lithium ion secondary battery positive electrode of the present invention is with in paste compound, preferably described fluorine-containing poly-The content of compound X is counted with quality criteria with respect to the ratio (X/Y) of the content of described polymer Y9.5/0.5～5.5/4.5. If make X/Y in above-mentioned scope, can fully improve paste compoundDispersiveness and viscosity stability. In addition, if make X/Y in above-mentioned scope, can fully guaranteeThe close-burning while of binding material, the lithium ion secondary electricity that further raising use paste compound is madeThe cycle characteristics in pond and speed characteristic.

In addition, lithium ion secondary battery positive electrode of the present invention is with in paste compound, preferably described fluorine-containing poly-The content of compound X is counted with quality criteria with respect to the ratio (X/Z) of the content of described polymer Z9.5/0.5～5.5/4.5. If make X/Z in above-mentioned scope, the sticky of binding material can fully guaranteedKnot property, further cycle characteristics and the speed that improves the lithium rechargeable battery that uses paste compound makingCharacteristic.

Further, lithium ion secondary battery positive electrode of the present invention is used in paste compound, preferred described polymerizationThing Z also contains containing acidic-group monomeric unit. If use the polymerization containing containing acidic-group monomeric unitThing Z, can, in the close-burning while of fully improving binding material, further improve and use slurryThe cycle characteristics of the lithium rechargeable battery that composition is made.

At this, from improving the caking property of binding material and the cycle characteristics of lithium rechargeable batteryThe viewpoint that suppresses the reduction of the viscosity stability of paste compound, described polymer Z preferably containsThe described acidic-group monomeric unit that contains more than 10 quality % and below 30 quality %.

In addition, lithium ion secondary battery positive electrode of the present invention is used in paste compound, preferred described polymerThe insoluble one-tenth component of Y in 1-METHYLPYRROLIDONE is below 5 quality %. If used at N-methylInsoluble one-tenth component in pyrrolidones is the polymer Y below 5 quality %, can suppress slurry combinationThe reduction of the viscosity stability of thing.

In addition, lithium ion secondary battery positive electrode of the present invention is used in paste compound, preferred described polymerThe insoluble one-tenth component of Z in 1-METHYLPYRROLIDONE is below 50 quality %. If used at N-methylInsoluble one-tenth component in pyrrolidones is the polymer Z below 50 quality %, can suppress slurry combinationThe reduction of the viscosity stability of thing.

It should be noted that, in the present invention, " the not melt into of polymer in 1-METHYLPYRROLIDONEComponent " can use the assay method of recording in the embodiment of this description to measure.

In addition, lithium ion secondary battery anode of the present invention is characterised in that to possess and make on collector bodyClose material layer with the positive pole that above-mentioned any lithium ion secondary battery positive electrode paste compound forms. In this wiseUse possesses the positive pole that uses above-mentioned lithium ion secondary battery positive electrode paste compound to form and closes material layerWhen lithium ion secondary battery anode, can fully improve cycle characteristics and the speed of lithium rechargeable batteryCharacteristic.

Further, lithium rechargeable battery of the present invention is characterised in that, comprises above-mentioned lithium ion secondaryPositive electrode for battery, negative pole, electrolyte and dividing plate. Use in this wise above-mentioned lithium rechargeable battery just usingWhen the utmost point, can provide high performance lithium rechargeable battery.

The effect of invention

According to the present invention, can provide and can make the performance of lithium rechargeable battery, especially cycle characteristicsAnd speed characteristic further improves and the lithium ion secondary battery positive electrode slurry of viscosity stability excellenceComposition.

In addition, according to the present invention, can provide can make lithium rechargeable battery performance, especially followThe lithium ion secondary battery anode that ring property and speed characteristic further improve.

Further, according to the present invention, can provide high performance lithium rechargeable battery.

Detailed description of the invention

Below, be described in detail for embodiments of the present invention.

At this, lithium ion secondary battery positive electrode of the present invention is forming lithium ion secondary electricity with paste compoundWhen pond anodal, use. In addition, lithium ion secondary battery anode of the present invention is to have use the present inventionThe positive pole that forms with paste compound of lithium ion secondary battery positive electrode to close material layer be feature. In addition, thisBright lithium rechargeable battery is to use lithium ion secondary battery anode of the present invention as feature.

(lithium ion secondary battery positive electrode paste compound)

Lithium ion secondary battery positive electrode paste compound of the present invention is using organic solvent as disperseing JieThe paste compound of matter, it comprises positive active material, conductive material, binding material and organic solvent.

In addition, lithium ion secondary battery positive electrode of the present invention is characterised in that with paste compound, as leadingElectric material, using BET specific area is 400m²Conductive material more than/g.

In addition, lithium ion secondary battery positive electrode of the present invention is characterised in that with paste compound, bonding materialMaterial comprises following (1)～(3) described polymer X, Y, Z, and the ratio of polymer X in binding materialExample is more than 50 quality % and below 95 quality %.

(1) fluoropolymer X

(2) the polymer Y that contains the above and following nitrile group-containing monomeric unit of 50 quality % of 10 quality %

(3) contain 50 quality % above and following (methyl) alkyl acrylate monomer units of 90 quality %Polymer Z

It should be noted that, in the present invention, " (methyl) acrylic acid " represents acrylic acid and/or methyl-propOlefin(e) acid. In addition, in the present invention, " comprising monomeric unit " refers to " poly-what use this monomer to obtainIn compound, comprise the construction unit that is derived from monomer ".

As being engaged in the positive active material in paste compound for lithium ion secondary battery positive electrode, do not haveLimit especially, can use known positive active material.

Specifically, as positive active material, be not particularly limited, can enumerate: containing the cobalt oxygen of lithiumCompound (LiCoO₂), LiMn2O4 (LiMn₂O₄), containing the nickel oxide (LiNiO of lithium₂), the containing of Co-Ni-MnThe lithium-contained composite oxide of lithium composite xoide, Ni-Mn-Al, the lithium-contained composite oxide of Ni-Co-Al,Olivine-type LiFePO4 (LiFePO₄), olivine-type lithium manganese phosphate (LiMnPO₄), with Li_1+xMn_2-xO₄Excessive spinel compound, the Li[Ni of lithium that (0 < X < 2) represents_0.17Li_0.2Co_0.07Mn_0.56]O₂、LiNi_0.5Mn_1.5O₄Deng.

In above-mentioned, from improving the lithium that has used lithium ion secondary battery positive electrode paste compound to formThe viewpoint of battery capacity of anodal lithium rechargeable battery etc. for ion secondary battery, as positive poleActive material, preferably uses the cobalt/cobalt oxide (LiCoO containing lithium₂), containing the nickel oxide (LiNiO of lithium₂)、The lithium-contained composite oxide of Co-Ni-Mn, the lithium-contained composite oxide of Ni-Co-Al,Li[Ni_0.17Li_0.2Co_0.07Mn_0.56]O₂Or LiNi_0.5Mn_1.5O₄。

It should be noted that, be not particularly limited for use level, the particle diameter of positive active material, canWith same with the positive active material using in the past.

Conductive material is for guaranteeing the positive active material material electrically contacting to each other. In addition, at thisThe conductive material using in paste compound for lithium ion secondary battery positive electrode of invention, its BET is than tableArea need to be at 400m²More than/g, the BET specific area of preferred conductive material is at 500m²More than/g,More preferably at 600m²More than/g, further preferably at 700m²More than/g, in addition preferably at 3000m²/gBelow, further preferably at 2000m²Below/g, further preferably at 1270m²Below/g, especially excellentBe selected in 900m²Below/g.

If the BET specific area of the conductive material using is at 400m²More than/g, even if conduct electricity materialThe use level of material is a small amount of, and the positive pole that also can use paste compound to form closes the electronics in material layerMigration become easily, thereby make lithium rechargeable battery speed characteristic improve. In addition, if usedThe BET specific area of conductive material at 3000m²Below/g, by with binding material group described laterClose use, dispersiveness and the viscosity stability that can suppress fully paste compound reduce.

At this, as conductive material, as long as thering is the material of above-mentioned BET specific area, do not haveHave especially and limit, can use known conductive material. Specifically, as conductive material, canUse acetylene black, Ketjen black (registration mark), furnace black, graphite, carbon fiber, carbon thin slice (carbonFlakes), the conductive carbon material such as carbon superbhort fiber (for example, CNT, gas-phase growth of carbon fibre etc.);Fiber, the paper tinsel etc. of various metals. Wherein, from keeping the battery capacity of lithium rechargeable batteryFully improve the viewpoint of speed characteristic, as conductive material, preferably use acetylene black or Ketjen black (noteVolume trade mark).

It should be noted that, as conductive material, can use separately and there is above-mentioned BET specific surface1 kind of long-pending conductive material, also can lead having the two or more of mutually different BET specific areaElectric material is used in combination and makes the BET specific area of mixed conductive material to reach in above-mentioned scopeSize.

Further, with respect to every 100 mass parts of positive active material, the use level of conductive material is preferablyMore than 0.5 mass parts, more preferably more than 1.0 mass parts, be preferably below 3.0 mass parts, more preferablyBe below 2.5 mass parts, more preferably below 2.0 mass parts. If the use level of conductive materialVery few, sometimes can not fully guarantee positive active material electrically contacting to each other, cannot fully improve lithiumThe speed characteristic of ion secondary battery. On the other hand, if the use level of conductive material is too much, existThe hidden danger that causes the viscosity stability of lithium ion secondary battery positive electrode paste compound to reduce, and existThe density that causes positive pole in lithium ion secondary battery anode to close material layer reduces, cannot realize fully lithiumThe hidden danger of the high capacity of ion secondary battery.

Binding material is to exist at the lithium ion secondary battery positive electrode paste compound of the application of the inventionOn collector body, form in the anodal positive pole that closes material layer and manufacture, keep anodal and close composition contained in material layer notFrom positive pole close material pull-up from composition. Conventionally the binding material that, positive pole closes in material layer impregnated in electrolyteTime, can Electolyte-absorptive and occur swelling, but can make positive active material to each other, positive active materialAnd between conductive material or conductive material bond to each other, thereby prevent that positive active material etc. is from collectionElectricity body comes off.

In addition, must with the binding material of paste compound for lithium ion secondary battery positive electrode of the present inventionMust comprise and can dissolve or be dispersed in as following 3 in the organic solvent of decentralized medium using given ratioPlant polymer.

Specifically, binding material comprises:

(1) fluoropolymer X,

The polymer Y that (2) contains the above and following nitrile group-containing monomeric unit of 50 quality % of 10 quality %,And

(3) contain 50 quality % above and following (methyl) alkyl acrylate monomer units of 90 quality %Polymer Z,

And when the polymer comprising as binding material is made as 100 quality %, fluoropolymer XRatio need to be more than 50 quality % and below 95 quality %.

So, if use fluoropolymer X, polymer Y, polymer Z as binding materialAnd the ratio that makes the fluoropolymer X in binding material is 50～95 quality %, can fully improve and makeFollowing of the lithium rechargeable battery of making of lithium ion secondary battery positive electrode of the present invention paste compoundRing property and speed characteristic, even and in the situation that has used the conductive material that BET specific area is largeUnder, also can make the viscosity stability of paste compound good.

At this, can by use above-mentioned binding material improve paste compound viscosity stability,And the cycle characteristics of lithium rechargeable battery and the mechanism of speed characteristic is still not clear, but can be speculated asMechanism as described below.

, caking property is not high compared with fluoropolymer X and polymer Z etc., regulates slurry group in performanceWhen the function of compound viscosity, in the time forming positive pole and close material layer, can be present in that positive pole closes in material layer and notIt is the surface of clad anode active material, conductive material. In addition, the nitrile group-containing that contains 10～50 quality %The caking property excellence of the polymer Y of monomeric unit, and the surface of coated with conductive material and the material that makes to conduct electricityThe favorable dispersibility of material, thereby the viscosity stability of raising paste compound. In addition, contain 50～90 matterThe caking property excellence of the polymer Z of (methyl) alkyl acrylate monomer units of amount %, and formingThe surface of clad anode active material when positive pole closes material layer and protect positive active material, thus battery improvedLife-span (cycle characteristics). Therefore, by making the ratio of fluoropolymer X more than 50 quality %, canPrevent from closing at positive pole that conductive material, positive active material in material layer are aggregated thing Y, polymer Z excessively wrapsCover, thus the speed characteristic of raising lithium rechargeable battery. In addition, by making fluoropolymer X'sRatio is below 95 quality % and coordinate polymer Y and polymer Z, can be by polymer Y andImprove the viscosity stability of paste compound, and guarantee caking property by polymer Z, thereby improve lithiumThe cycle characteristics of ion secondary battery.

It should be noted that, binding material can also contain except fluoropolymer X, polymer Y and polymerizationOther polymer beyond thing Z, but from obtaining well the viewpoint of above-mentioned effect, material preferably bondsIn material, the ratio of other polymer is below 10 quality %, preferably binding material only by fluoropolymer X,Polymer Y and polymer Z form.

[fluoropolymer X]

Fluoropolymer X is the polymer that contains fluorine-containing monomer unit. Specifically, as fluoropolymerThing X, can enumerate: more than a kind homopolymers of fluorochemical monomer or copolymer, more than a kind fluorochemical monomerDo not contain the copolymer of the monomer (following, to be called " not fluorochemical monomer ") of fluorine.

It should be noted that, in fluoropolymer X, the ratio of fluorine-containing monomer unit is conventionally at 70 quality %Above, preferably more than 80 quality %. In addition, the ratio of fluorine-containing monomer unit not in fluoropolymer XExample is conventionally below 30 quality %, preferably below 20 quality %.

At this, as the fluorochemical monomer that can form fluorine-containing monomer unit, can enumerate: vinylidene,Tetrafluoroethene, hexafluoropropene, CTFE, PVF, perfluoroalkyl vinyl ether etc. Wherein,As fluorochemical monomer, preferably vinylidene.

In addition, as forming the not fluorochemical monomer of fluorine-containing monomer unit, can enumerate can with containThe monomer that does not contain fluorine of fluorine monomer copolymerization, for example: the 1-alkene such as ethene, propylene, 1-butylene; Benzene secondThe aromatic vinyls such as alkene, AMS, p-tert-butylstyrene, vinyltoluene, chlorostyreneBased compound; The unsaturated nitrile compounds such as (methyl) acrylonitrile; (methyl) methyl acrylate, (methyl) propylene(methyl) acrylate compounds such as acid butyl ester, (methyl) 2-EHA; (methyl) acrylamide,(methyl) acryloyl aminations such as N-methylol (methyl) acrylamide, N-butoxymethyl (methyl) acrylamideCompound; The ethene that (methyl) acrylic acid, itaconic acid, fumaric acid, crotonic acid, maleic acid etc. contain carboxylBased compound; Allyl glycidyl ether, (methyl) glycidyl acrylate etc. are unsaturated containing epoxy radicalsCompound; (methyl) acrylic acid dimethylamino ethyl ester, (methyl) acrylic acid diethylamino ethyl ester etc. containAmino unsaturated compound; Styrene sulfonic acid, vinyl sulfonic acid, (methyl) allyl sulphonic acid etc. are containing sulfonic acidBase unsaturated compound; The sulfur-bearing acidic group unsaturated compounds such as 3-allyloxy-2-hydroxy propane sulfuric acid; (firstBase) the phosphorous acidic group such as the chloro-2-phosphoric acid of acrylic acid-3-propyl ester, 3-allyloxy-2-hydroxy propane phosphoric acid is unsaturatedCompound etc.

In addition, as fluoropolymer X, preferably use the polymer of vinylidene as fluorochemical monomer,And used the polymer of PVF as fluorochemical monomer, more preferably use vinylidene as fluorine-containingThe polymer of monomer.

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

It should be noted that, above-mentioned fluoropolymer X can use separately one, in addition also can be by 2More than kind, be used in combination.

At this, the polystyrene conversion value obtaining based on gel permeation chromatography of fluoropolymer XWeight average molecular weight is preferably 100000～2000000, and more preferably 200000～1500000, especially preferredBe 400000～1000000.

By making the weight average molecular weight of fluoropolymer X in above-mentioned scope, can suppress positive electrode active materialMatter, conductive material etc. close material pull-up from (dry linting) from positive pole, and in addition, the viscosity of paste compound regulates and becomesObtain easily.

In addition, the glass transition temperature of fluoropolymer X (Tg) is preferably below 0 DEG C, more preferably existBelow-20 DEG C, particularly preferably in below-30 DEG C. The lower limit of Tg to fluoropolymer X is not specialGround limit, preferably more than-50 DEG C, more preferably more than-40 DEG C. By making fluoropolymer X'sTg, in above-mentioned scope, can suppress positive active material, conductive material etc. and close material pull-up from (falling from positive polePowder). It should be noted that, the Tg of fluoropolymer X can be used for by change the kind of the monomer of polymerizationClass is adjusted. It should be noted that, Tg can use differential scanning calorimeter, based on JISK7121;1987 measure.

The fusing point (Tm) of fluoropolymer X preferably below 190 DEG C, more preferably 150～180 DEG C, enterOne step is preferably 160～170 DEG C. By making the Tm of fluoropolymer X in above-mentioned scope, can obtainThe positive pole of flexibility and dhering strength excellence. It should be noted that, the Tm of fluoropolymer X can lead toCrossing change adjusts for the kind of the monomer of polymerization or control polymerization temperature etc. Need to illustrateThat Tm can use differential scanning calorimeter, based on JISK7121; 1987 measure.

At this, the manufacture method of above-mentioned fluoropolymer X is not particularly limited, for example, can makeBy any means in solution polymerization process, suspension polymerization, mass polymerization, emulsion polymerization etc.

In addition, as polymerization, can use ionic polymerization, radical polymerization, living radical to gatherThe addition polymerization such as close. In addition, as polymerization initiator, can use known polymerization initiator.

In addition, fluoropolymer X can disperse to be situated between to be dispersed in the dispersion liquid in decentralized medium or to be dissolved inThe state of the solution in matter uses. As the decentralized medium of fluoropolymer X, as long as can be evenDisperse or dissolve the decentralized medium of fluoropolymer X, be not particularly limited, can useWater, organic solvent, preferably with an organic solvent. It should be noted that, as organic solvent, there is no spyDo not limit the organic solvent that can be used as the decentralized medium of paste compound to use.

[polymer Y]

Polymer Y contains 10 quality % above and the polymerization of the following nitrile group-containing monomeric unit of 50 quality %Thing. Specifically, as polymer Y, can enumerate a kind of above nitrile group-containing monomer and can with thisThe copolymer of the monomer of nitrile group-containing monomer copolymerization. In addition, as polymer Y, be not particularly limited,For example can use ratios above with 10 quality % and below 50 quality % are contained to acrylonitrile unitAcrylonitrile-butadiene copolymer (NBR) utilizes known method to carry out hydrogenation and the hydrogenated nbr that obtains.

It should be noted that, polymer Y also can have the monomeric unit (fluorine-containing monomer unit) that contains fluorine,But in polymer Y the ratio of fluorine-containing monomer unit conventionally below 40 quality %, preferably at 30 quality %Below, polymer Y is the polymer different from aforesaid fluoropolymer X.

At this, as the nitrile group-containing monomer that can form nitrile group-containing monomeric unit, can enumerate α, β-olefinicUnsaturated nitrile monomer. In addition, as α, β-olefinically unsaturated nitriles monomer, as long as thering is the α of itrile group, β-Alefinically unsaturated compounds is not particularly limited, and for example can enumerate acrylonitrile; Alpha-chloro propyleneThe alpha-halogen such as nitrile, alpha-brominated acrylonitrile acrylonitrile; The alpha-alkyl such as methacrylonitrile, α-ethyl acrylonitrile thirdAlkene nitrile; Etc.. Wherein, the viewpoint of the cohesive force of the binding material that comprises polymer Y from raising,As nitrile group-containing monomer, preferably acrylonitrile and methacrylonitrile, more preferably acrylonitrile.

These monomers can use separately one or be used in combination of two or more.

In addition, it is above and 50 that the ratio of the nitrile group-containing monomeric unit in polymer Y is necessary for 10 quality %Below quality %, preferably more than 15 quality %, in addition, preferably below 40 quality %, more preferablyBelow 30 quality %. This be because, if the ratio of nitrile group-containing monomeric unit more than 10 quality %,Can improve fully the cohesive force of the binding material that comprises polymer Y; In addition, if nitrile group-containingThe ratio of monomeric unit, below 50 quality %, can fully improve the viscosity stabilization of paste compoundProperty.

In addition, as can with the monomer of nitrile group-containing monomer copolymerization, be not particularly limited, can enumerate:1-alkene, conjugated diene compound, (methyl) acrylate compounds, there is gathering of hydrophilic radicalCombination compound etc. In addition, as can with the monomer of nitrile group-containing monomer copolymerization, preferably at least use 1-Alkene or conjugated diene compound. , polymer Y preferably comprise be derived from 1-alkene monomeric unit orBe derived from the monomeric unit of conjugated diene compound.

It should be noted that, use conjugated diene compound as can with the list of nitrile group-containing monomer copolymerizationIn the situation of body, the conjugated diene monomeric unit that is derived from conjugated diene compound being present in polymer existsAfter polymerization, be optionally hydrogenated.

In addition, these monomers can use separately one or be used in combination of two or more.

At this, as 1-alkene, for example can enumerate: ethene, propylene, 1-butylene etc. Wherein, doFor 1-alkene, optimal ethylene.

In addition, as conjugated diene compound, for example can enumerate: 1,3-butadiene, isoprene,More than 4 conjugated diene compounds of carbon number such as 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene. ThisIn a little, preferably 1,3-butadiene.

In addition, as (methyl) acrylate compounds, can enumerate: methyl acrylate, ethyl acrylate,Acrylic acid n-propyl, isopropyl acrylate, n-butyl acrylate, tert-butyl acrylate, acrylic acid isobutylEster, acrylic acid n-pentyl ester, acrylic acid isopentyl ester, Hexyl 2-propenoate, acrylic acid heptyl ester, 2-ethyl hexyl acrylate,2-EHA, acrylic acid ester in the ninth of the ten Heavenly Stems, decyl acrylate, lauryl acrylate, acrylic acid positive tenThe alkyl acrylates such as tetraalkyl ester, stearyl acrylate ester; Methyl methacrylate, methacrylic acid secondEster, n propyl methacrylate, isopropyl methacrylate, n-BMA, metering systemTert-butyl acrylate, isobutyl methacrylate, methacrylic acid n-pentyl ester, metering system isoamyl valerate, firstBase Hexyl 2-propenoate, metering system heptyl heptylate, 2-Propenoic acid, 2-methyl-, octyl ester, 2-Ethylhexyl Methacrylate,Nonyl methacrylate, decyl-octyl methacrylate, lauryl methacrylate, methacrylic acid positive 14The alkyl methacrylates such as Arrcostab, methacrylic acid stearyl ester; Etc.. Wherein, from improving polymerizationThing Y as decentralized medium use organic solvent in dissolubility and the viewpoint of flexibility set out, doFor (methyl) acrylate compounds, with the carbon number of the alkyl of non-carbonyl oxygen atom bonding be preferably4～10 alkyl acrylate, wherein, concrete preferably n-butyl acrylate, 2-EHAAnd lauryl acrylate, more preferably n-butyl acrylate, 2-EHA.

In addition, as have hydrophilic radical can polymerization compound, can enumerate: there is carboxylic acidThe compound of base, there is sulfonic compound, have phosphate compound, there is the chemical combination of hydroxylThing. It should be noted that, the viewpoint of the cohesive force of the binding material that comprises polymer Y from raising,Hydrophilic radical is preferably carboxylic acid group or sulfonic group, more preferably carboxylic acid group.

As the compound with carboxylic acid group, can enumerate: monocarboxylic acid and derivative thereof, dicarboxylic acidsAnd acid anhydrides and their derivative etc.

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

As monocarboxylic acid derivative, can enumerate: 2-ethylacrylic acid, iso-crotonic acid, α-acetyl oxygenBase acrylic acid, β-trans-aryloxy group acrylic acid, α-chloro-β-E-methoxy acrylic acid, β-diaminourea acrylic acidDeng.

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

As dicarboxylic acid derivatives, can enumerate: citraconic acid, dimethyl maleic acid, phenyl horseCome sour, chlorine maleic acid, dichloromaleic acid, fluorine maleic acid, maleic acid methyl allyl ester, maleic acid hexicholEster, maleic acid ester in the ninth of the ten Heavenly Stems, maleic acid ester in the last of the ten Heavenly stems, maleic acid dodecyl ester, maleic acid stearyl, horseCarry out the maleates such as sour fluoroalkyl ester.

As the acid anhydrides of dicarboxylic acids, can enumerate: maleic anhydride, acrylic anhydride, methyl maleic anhydride,Dimethyl maleic anhydride etc.

In addition, as the compound with carboxylic acid group, can also use the acid that generates carboxyl by being hydrolyzedAcid anhydride.

Can enumerate in addition: ethyl maleate, diethyl maleate, butyl maleate, MalaysiaDibutyl phthalate, monomethyl ester, DEF, fumaric acid mono-n-butylester, dibutyl fumarate,Momo-cyclohexyl fumarte, fumaric acid two cyclohexyls, itaconic acid mono ethyl ester, diethyl itaconate, itaconic acidThe α such as mono-n-butylester, dibutyl itaconate, the unsaturated polybasic carboxylic acid monoesters of β-olefinic and diester.

As thering is sulfonic compound, can enumerate: vinyl sulfonic acid, methyl ethylene sulfonic acid,(methyl) allyl sulphonic acid, styrene sulfonic acid, (methyl) acrylic acid-2-sulfonic acid ethyl ester, 2-acrylamide-2-Methyl propane sulfonic acid, 3-allyloxy-2-hydroxy-propanesulfonic acid etc.

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

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

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

As the compound with hydroxyl, can enumerate: (methyl) allyl alcohol, 3-butene-1-ol, 5-hexeneThe olefinic unsaturated alcohols such as-1-alcohol; 2-Hydroxy ethyl acrylate, 2-hydroxypropyl acrylate, metering systemAcid-2-hydroxy methacrylate, methacrylic acid-2-hydroxy propyl ester, maleic acid two (2-hydroxyethyl) ester, maleic acidThe alkane alkoxide of the ethylenically unsaturated carboxylic acids such as two (4-hydroxybutyl) ester, itaconic acid two (2-hydroxypropyl) ester;General formula CH₂＝CR¹-COO-(C_nH_2nO)_m(in formula, m represents 2～9 integer to-H, and n represents 2～4Integer, R¹Represent hydrogen or methyl) shown in PAG and the ester class that forms of (methyl) acrylic acid; 2-Hydroxyethyl-2 '-(methyl) acryloxy phthalic acid ester, 2-hydroxyethyl-2 '-(methyl) acryloyl-oxyList (methyl) esters of acrylic acid of the dihydroxy ester of the dicarboxylic acids such as base succinate; 2-hydroxyethyl etheneThe vinyl ethers such as base ether, 2-hydroxypropyl vinyl ethers; (methyl) pi-allyl-2-hydroxyethyl ether, (firstBase) pi-allyl-2-hydroxypropyl ether, (methyl) pi-allyl-3-hydroxypropyl ether, (methyl) pi-allyl-2-hydroxylButyl ether, (methyl) pi-allyl-3-hydroxybutyl ether, (methyl) pi-allyl-4-hydroxybutyl ether, (methyl)List (methyl) allyl ether series of the aklylene glycols such as pi-allyl-6-hydroxyl hexyl ether; Diethylene glycol list (methyl)Polyether polyols (methyl) mono allyl ethers such as allyl ether, DPG list (methyl) allyl etherClass; Glycerine list (methyl) allyl ether, (methyl) pi-allyl-2-chloro-3-hydroxyl propyl ether, (methyl) allylThe halogen of (gathering) aklylene glycol and list (methyl) allyls of hydroxyl substituent such as base-2-hydroxyl-3-chloropropyl etherBase ether; List (methyl) allyl ether and the halogen substituent thereof of the polyhydric phenols such as eugenol, isoeugenol;The aklylene glycols such as (methyl) pi-allyl-2-hydroxyethyl thioether, (methyl) pi-allyl-2-hydroxypropyl thioether(methyl) allyl sulfide ethers etc.

At this, polymer Y have be derived from 1-alkene monomeric unit, be derived from after polymerization throughIn the monomeric unit (, the conjugated diene monomeric unit of hydrogenation) of the conjugated diene compound of hydrogenation at leastIn the situation of one, the monomeric unit that is derived from 1-alkene in polymer Y and the conjugated diene list of hydrogenationTotal ratio of body unit is preferably more than 40 quality %, more preferably more than 50 quality %, furtherPreferably, more than 55 quality %, preferably, below 90 quality %, more preferably, below 80 quality %, enterOne step is preferably below 75 quality %, below 70 quality %. This is because be derived from 1-If the toatl proportion of the conjugated diene monomeric unit of the monomeric unit of alkene and hydrogenation more than 40 quality %,Can improve fully dispersiveness and the viscosity stability of paste compound, and can further improveThe speed characteristic of lithium rechargeable battery; In addition, be derived from the monomeric unit of 1-alkene and the conjugation of hydrogenation twoIf the toatl proportion of alkene monomer unit, below 90 quality %, can be guaranteed the viscosity of paste compoundStability, and can suppress the reduction of the cohesive force of the binding material that comprises polymer Y.

In addition, there is at polymer Y the monomer that is derived from the conjugated diene compound not being hydrogenated after polymerizationUnit, be derived from the monomeric unit of (methyl) acrylate compounds or be derived from there is hydrophilic radical canIn the situation of the monomeric unit of the compound of polymerization, the toatl proportion of these monomeric units is preferably at 40 quality %Below, more preferably below 30 quality %, further preferably below 20 quality %. This is because of thisIf the toatl proportion of a little monomeric units, below 40 quality %, can make to comprise the sticky of polymer YWhen the cohesive force of knot material improves, suppress the reduction of the viscosity stability of paste compound.

It should be noted that, polymer Y have be derived from have carboxylic acid group can polymerization compoundIn the situation of monomeric unit, its ratio is preferably below 10 quality %, more preferably below 5 quality %.This be because, if be derived from have carboxylic acid group can polymerization the ratio of monomeric unit of compound existBelow 10 quality %, can fully suppress the reduction of the viscosity stability of paste compound.

Further, the insoluble one-tenth component of polymer Y in 1-METHYLPYRROLIDONE is (below also referred to as " NMPInsoluble one-tenth component ") preferably below 5 quality %. This be because if the insoluble one-tenth component of NMP in 5 matterAmount % below, can suppress condensation product in paste compound generation, make the viscosity of paste compound steadyQualitative good.

It should be noted that, the insoluble one-tenth component of NMP of polymer Y can be used for polymer by changeThe kind of the monomer of the polymerization of Y, amount, polymerizing condition are adjusted, for example, if increase polymerThe ratio of the nitrile group-containing monomeric unit in Y, can reduce the insoluble one-tenth component of NMP. In addition, also canReduce with the cross-linkable monomer that crosslinked functional group can occur by not having after polymerizationThe insoluble one-tenth component of NMP.

In addition, the weight average molecular weight of the polystyrene conversion value based on gel permeation chromatography of polymer YBe preferably 10000～700000, more preferably 50000～500000, be particularly preferably 100000～300000.If the weight average molecular weight of polymer Y in above-mentioned scope, can make positive pole have flexibility, and thenMake the viscosity adjustment of paste compound become easy.

Further, the glass transition temperature of polymer Y (Tg) is preferably below 25 DEG C, more preferably existBelow 15 DEG C, particularly preferably in below 0 DEG C. For not limit especially of the lower limit of the Tg of polymer YFixed, but preferably more than-50 DEG C, more preferably more than-45 DEG C, particularly preferably in more than-40 DEG C. Pass throughMake the Tg of polymer Y in above-mentioned scope, can be suppressed at dry linting, raising in anodal manufacturing processUse the cycle characteristics of this anodal lithium rechargeable battery. It should be noted that, polymer Y'sThe kind that Tg can be used for the monomer of polymerization by change is adjusted.

In addition, above-mentioned polymer Y can similarly manufacture and use with fluoropolymer X.

[polymer Z]

Polymer Z is for containing 50 quality % above and following (methyl) alkyl acrylate list of 90 quality %The polymer of body unit. Specifically, as polymer Z, can enumerate a kind of above (methyl) propyleneAcid alkyl ester monomer and can with the copolymer of the monomer of this (methyl) alkyl acrylate monomer copolymerization.

It should be noted that, polymer Z also can have fluorine-containing monomer unit, but fluorine-containing in polymer ZThe ratio of monomeric unit conventionally below 40 quality %, preferably below 30 quality %, polymer Z isThe polymer different from aforesaid fluoropolymer X.

At this, as (methyl) acrylic acid alkyl that can form (methyl) alkyl acrylate monomer unitsEster monomer, can use and (methyl) acrylate that can use in the polymerization of above-mentioned polymer YThe monomer that compound is same. Wherein, as (methyl) alkyl acrylate monomer of polymer Z, preferablyAlkyl acrylate, the viewpoint of the cohesive force of the binding material that comprises polymer Z from raising, more excellentSelect n-butyl acrylate, 2-EHA.

These (methyl) alkyl acrylate monomers can use separately one or be used in combination two or more.

In addition, the ratio of (methyl) alkyl acrylate monomer units in polymer Z must be in 50 matterAmount % is above and below 90 quality %, preferably more than 55 quality %, and preferably below 80 quality %,More preferably below 75 quality %, further preferably below 70 quality %. This be because, (methyl)If the ratio of alkyl acrylate monomer units, more than 50 quality %, can fully improve and compriseThe cohesive force of the binding material of polymer Z; In addition, the ratio of (methyl) alkyl acrylate monomer unitsIf below 90 quality %, can suppress the reduction of cycle characteristics.

In addition, as can with the monomer of (methyl) alkyl acrylate monomer copolymerization, not especially limitFixed, can enumerate monomer (containing acidic-group monomer), nitrile group-containing monomer, the bridging property with acidic-groupMonomer, aromatic vinyl monomer, ethylenically unsaturated carboxylic acids amide monomer etc. In addition, as can be withThe monomer of (methyl) alkyl acrylate monomer copolymerization, preferably use at least has the monomer of acidic-group., polymer Z preferably comprises the monomeric unit (containing acidic-group monomeric unit) with acidic-group.

It should be noted that, these monomers can use separately one or be used in combination two or more.

At this, as the monomer with acidic-group, be not particularly limited, can use and there is carboxylic acidThe monomer of base, there is sulfonic monomer, there is the monomer of phosphate. It should be noted that, from effectivelyTake into account the raising of cohesive force and the circulation of lithium rechargeable battery of the binding material that comprises polymer ZThe viewpoint of the raising of characteristic is set out, and as the monomer with acidic-group, preferably uses and has carboxylic acid group'sMonomer and have at least one in sulfonic monomer, is more preferably used in combination the monomer with carboxylic acid groupWith there is sulfonic monomer.

As the monomer with carboxylic acid group, can use with above-mentioned and can in the polymerization of polymer Y, useThe same monomer of the compound with carboxylic acid group. Wherein, from having used the bonding that comprises polymer ZThe paste compound of material shows good dispersed viewpoint and sets out, as the list with carboxylic acid groupBody, preferably uses monocarboxylic acid, more preferably uses acrylic acid, methacrylic acid, particularly preferably uses firstBase acrylic acid.

As thering is sulfonic monomer, can enumerate: vinyl sulfonic acid, methyl ethylene sulfonic acid, benzeneVinyl sulfonic acid, (methyl) propene sulfonic acid ((meta) acrylsulfonicacid), (methyl) acrylic acid-2-sulfonic acid secondEster, 2-acrylamide-2-hydroxy-propanesulfonic acid, 2-acrylamide-2-methyl propane sulfonic etc. Wherein, from makingWith comprise polymer Z the paste compound of binding material show good dispersed viewpoint and set out,As thering is sulfonic monomer, preferably use 2-acrylamide-2-hydroxy-propanesulfonic acid, 2-acrylamide-2-Methyl propane sulfonic acid, more preferably uses 2-acrylamide-2-methyl propane sulfonic.

As the monomer with phosphate, can enumerate: the chloro-2-phosphoric acid of (methyl) acrylic acid-3-propyl ester, (firstBase) acrylic acid-2-phosphoric acid ethyl, 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 be also alkali metal saltOr the form of ammonium salt.

In addition, as nitrile group-containing monomer, can use with above-mentioned and can in the polymerization of polymer Y, useThe same monomer of nitrile group-containing monomer. Wherein, close the adaptation between material layer and collector body from improving positive poleThereby the viewpoint that improves anodal intensity is set out, as nitrile group-containing monomer, preferably acrylonitrile and metering systemNitrile, more preferably acrylonitrile.

Further, as cross-linkable monomer, can enumerate: the monomer that contains epoxy radicals, contain carbon-to-carbonMonomer, the monomer that contains halogen atom and epoxy radicals of two keys and epoxy radicals, contain N-methylol amide baseMonomer, the monomer that contains oxa-cyclobutyl, containThe monomer of azoles quinoline base, there is more than 2 alkeneProperty two keys multi-functional monomer etc.

In addition, as aromatic vinyl monomer, can enumerate: styrene, AMS, rightT-butyl styrene, vinyltoluene, chlorostyrene etc.

Further, as ethylenically unsaturated carboxylic acids amide monomer, can enumerate: acrylamide, methyl-propAlkene acid amides, N,N-DMAA etc.

At this, comprise the monomeric unit with acidic-group polymer Z at polymer ZIn the ratio of the monomeric unit with acidic-group preferably more than 10 quality %, more preferably in 13 matterMore than amount %, further preferably more than 15 quality %, preferably, below 30 quality %, more preferably existBelow 27 quality %, further preferably below 25 quality %. This is because have acidic-groupIf the ratio of monomeric unit, more than 10 quality %, can make the binding material that comprises polymer ZCohesive force and the cycle characteristics of lithium rechargeable battery improve fully; In addition, there is acidic-groupIf the ratio of monomeric unit below 30 quality %, can suppress condensation product in paste compoundProduce, make the viscosity stability of paste compound good.

It should be noted that, in polymer Z, comprise and there is carboxylic acid group's monomeric unit and there is sulfonic groupMonomeric unit the two as having in the situation of monomeric unit of acidic-group, by quality ratio, poly-The ratio of the monomeric unit with carboxylic acid group in compound Z is with respect to having sulfonic monomeric unitThe ratio of ratio (have carboxylic acid group's monomeric unit/have sulfonic monomeric unit) is preferably99/1～85/15。

In addition, in the situation that polymer Z has nitrile group-containing monomeric unit, the nitrile group-containing in polymer ZThe ratio of monomeric unit is preferably more than 5 quality %, more preferably more than 10 quality %, further preferredMore than 15 quality %, preferably below 35 quality %, more preferably below 30 quality %, furtherPreferably below 25 quality %. This be because, if the ratio of nitrile group-containing monomeric unit in this scope,Can improve positive pole and close the adaptation between material layer and collector body, the intensity of gained positive pole is improved.

Further, there is cross-linkable monomer unit, aromatic vinyl monomer unit or alkene at polymer ZBelong in the situation of unsaturated carboxylic acid amide monomer unit, the toatl proportion of these monomeric units is preferably in 30 matterBelow amount %, more preferably below 25 quality %. This be because, if the toatl proportion of these monomeric unitsBelow 30 quality %, can fully improve the cohesive force of the binding material that comprises polymer Z.

At this, the insoluble one-tenth component (NMP insoluble one-tenth component) of polymer Z in 1-METHYLPYRROLIDONEBe preferably below 50 quality %, more preferably below 30 quality %, more preferably 20 quality % withUnder. This is because if the insoluble one-tenth component of NMP is below 50 quality %, can suppress slurry groupThe generation of the condensation product in compound, makes the viscosity stability of paste compound good.

It should be noted that, the insoluble one-tenth component of NMP of polymer Z can be used for polymer by changeThe kind of the monomer of the polymerization of Z, amount, polymerizing condition are adjusted, for example, if increase polymerThe ratio of the nitrile group-containing monomeric unit in Z, can reduce the insoluble one-tenth component of NMP.

In addition, the weight average molecular weight of the polystyrene conversion value based on gel permeation chromatography of polymer ZBe preferably 10000～2000000, more preferably 50000～1000000, be particularly preferably100000～500000. If the weight average molecular weight of polymer Z, in above-mentioned scope, can make anodal toolThere is flexibility, and then make the viscosity adjustment of paste compound become easy.

Further, the glass transition temperature of polymer Z (Tg) preferably, below 50 DEG C, more preferably existsBelow 10 DEG C. Lower limit for the Tg of polymer Z is not particularly limited, preferably more than-50 DEG C.By making the Tg of polymer Z in above-mentioned scope, can be suppressed at dry linting in anodal manufacturing process,Improve the cycle characteristics that has used this anodal lithium rechargeable battery. It should be noted that polymer ZThe Tg kind that can be used for the monomer of polymerization by change adjust.

In addition, above-mentioned polymer Z can similarly manufacture with fluoropolymer X, polymer Y andUse.

[content of polymer X, Y, Z]

At this, as previously mentioned, at lithium ion secondary battery positive electrode of the present invention with using in paste compoundBinding material in, the ratio of fluoropolymer X must be more than 50 quality % and below 95 quality %,The ratio of fluoropolymer X preferably, more than 60 quality %, more preferably, more than 67 quality %, enters oneStep is preferably more than 70 quality %, preferably below 90 quality %, more preferably below 85 quality %.This be because, if the ratio of fluoropolymer X, more than 50 quality %, can improve lithium ionThe speed characteristic of secondary cell; In addition, if the ratio of fluoropolymer X below 95 quality %,Can improve the viscosity stability of paste compound and the cycle characteristics of lithium rechargeable battery.

It should be noted that, the content of fluoropolymer X is preferably with respect to the content of polymer YMass ratio X/Y is the amount of 9.5/0.5～5.5/4.5, and more preferably making mass ratio X/Y is 9.5/0.5～6.5/3.5Amount, more preferably making mass ratio X/Y is the amount of 9.5/0.5～7.5/2.5. This be because, ifX/Y, below 9.5/0.5, can fully improve dispersiveness and the viscosity stability of paste compound,And, can guarantee fully the caking property of binding material further to improve following of lithium rechargeable batteryRing property; In addition, if X/Y, more than 5.5/4.5, can fully improve lithium rechargeable batterySpeed characteristic.

In addition, the content of fluoropolymer X is preferably the mass ratio X/Z with respect to the content of polymer ZFor the amount of 9.5/0.5～5.5/4.5, more preferably making mass ratio X/Z is the amount of 9.5/0.5～6.5/3.5, entersOne step is preferably and makes mass ratio X/Z is the amount of 9.5/0.5～7.5/2.5. This be because, if X/Z exists9.5/0.5 below, can fully guarantee the caking property of binding material, further improve lithium ion secondary electricityThe cycle characteristics in pond; In addition, if X/Z, more than 5.5/4.5, can fully improve lithium ion twoThe speed characteristic of primary cell.

Further, the content of polymer Y is preferably the mass ratio Y/Z with respect to the content of polymer ZBe 1/9～9/1 amount, more preferably making mass ratio Y/Z is 2/8～8/2 amount, more preferably makesMass ratio Y/Z is 3/7～7/3 amount. In the poor situation of polymer Y, exist and cause slurry groupThe hidden danger that the viscosity stability of compound reduces, in the poor situation of polymer Z, exists and causes gluingThe hidden danger that the caking property of knot material reduces, the cycle characteristics of lithium rechargeable battery declines.

Further, from take into account with high level paste compound viscosity stability, binding material caking property,The speed characteristic of lithium rechargeable battery and the viewpoint of cycle characteristics are set out, and polymer X, Y, Z containThe ratio (X/Y/Z) of amount is preferably 50～95/0.5～45/0.5～45 in quality criteria, more preferably60～90/0.4～36/0.4～36, more preferably 65～85/0.35～31.5/0.35～31.5.

[use level of binding material]

In addition, use in paste compound, with respect to every 100 at lithium ion secondary battery positive electrode of the present inventionThe positive active material of mass parts, more than the use level of binding material is preferably 0.5 mass parts, more preferablyBe more than 1.0 mass parts, be preferably below 2.5 mass parts, more preferably below 2.0 mass parts. AsThe use level of fruit binding material is very few, has viscosity stability hidden that cannot guarantee paste compoundSuffer from, and cannot guarantee fully cohesive force, possibly cannot improve fully following of lithium rechargeable batteryRing property. On the other hand, if the use level of binding material is too much, exists and cause lithium ion secondary electricityThe hidden danger that the speed characteristic in pond declines.

It should be noted that, with respect to the positive active material of every 100 mass parts, fluoropolymer XUse level be preferably 0.25 mass parts more than, more preferably more than 0.5 mass parts, more preferablyMore than 1.0 mass parts, be preferably below 2.475 mass parts, more preferably, below 1.9 mass parts, enter oneStep is preferably below 1.25 mass parts. This be because, if the use level of fluoropolymer X is very few,There is the hidden danger that cannot fully improve the speed characteristic of lithium rechargeable battery; In addition, if fluorine-containing poly-The use level of compound X is too much, has viscosity stability and the lithium that cannot fully improve paste compoundThe hidden danger of the cycle characteristics of ion secondary battery.

In addition, with respect to the positive active material of every 100 mass parts, the use level of polymer Y is preferredBe more than 0.025 mass parts, more preferably more than 0.05 mass parts, more preferably 0.1 mass partsAbove, be preferably below 1.25 mass parts, more preferably below 1.0 mass parts, more preferablyBelow 0.25 mass parts. This is because if the use level of polymer Y is very few, existing cannot be abundantThe viscosity stability of paste compound and the close-burning hidden danger of binding material are guaranteed in ground; In addition, if poly-The use level of compound Y is too much, the hidden danger that exists the speed characteristic that causes lithium rechargeable battery to decline.

Further, with respect to the positive active material of every 100 mass parts, the use level of polymer Z is excellentMore than electing 0.025 mass parts as, more preferably more than 0.05 mass parts, more preferably 0.1 qualityMore than part, be preferably below 1.25 mass parts, more preferably below 1.0 mass parts, more preferablyBelow 0.25 mass parts. This be because, if the use level of polymer Z is very few, cannot be true fullyProtect the caking property of binding material, the hidden danger that exists the cycle characteristics that causes lithium rechargeable battery to decline; SeparatelyIf the use level of polymer Z is too much, exists and cause under the speed characteristic of lithium rechargeable battery outward,The hidden danger of falling.

As at the organic solvent using in paste compound for lithium ion secondary battery positive electrode of the present invention,For example can use and can dissolve or disperse above-mentioned fluoropolymer X, polymer Y and polymer ZThere is the organic solvent of polarity.

Specifically, as organic solvent, can use: acetonitrile, 1-METHYLPYRROLIDONE, acetyl groupPyridine, cyclopentanone, DMA, dimethyl formamide, methyl-sulfoxide, NMF,MEK, furfural, ethylenediamine etc. In these, from processing ease, security, synthetic easinessSet out etc. viewpoint, as organic solvent, most preferably 1-METHYLPYRROLIDONE.

It should be noted that, these organic solvents can be used alone, but also also mix together two or more.

Except mentioned component, all right in lithium ion secondary battery positive electrode use paste compound of the present inventionContain for example viscosity modifier, reinforcing material, antioxidant, there is the function that suppresses electrolyte decompositionThe compositions such as electrolysis additive. These other compositions can use known material.

The manufacture method of paste compound for<lithium ion secondary battery positive electrode>

Lithium ion secondary battery positive electrode of the present invention can pass through molten above-mentioned each composition with paste compoundSeparate or be scattered in the organic solvent as decentralized medium and be prepared.

It should be noted that, the mixing of above-mentioned each composition and organic solvent can use ball mill, sand mill,Ball mill, Pigments machine, grater, ultrasonic dispersing machine, homogenizer, planetary-type mixer, FILMIXEtc. known mixer.

(lithium ion secondary battery anode)

Lithium ion secondary battery anode of the present invention just can use lithium rechargeable battery of the present inventionThe utmost point is manufactured with paste compound.

In addition, lithium ion secondary battery anode of the present invention possesses collector body and is formed on collector bodyPositive pole closes material layer, close in material layer at positive pole at least comprise positive active material, BET specific area is400m²Conductive material more than/g and comprise fluoropolymer X, polymer Y and polymer ZBinding material. It should be noted that, positive pole close the positive active material that comprises in material layer, conductive material andBinding material is to be included in the material in paste compound for lithium ion secondary battery positive electrode of the present invention, onState the preferred existence of each composition than using in paste compound with lithium ion secondary battery positive electrode of the present inventionThe preferred existence of each composition is than identical.

In addition, the positive pole of lithium ion secondary battery anode of the present invention close material layer be use the invention described aboveLithium ion secondary battery positive electrode form with paste compound, therefore can fully improve lithium ion twoThe cycle characteristics of primary cell and speed characteristic.

The manufacture method of<lithium ion secondary battery anode>

At this, do not limit especially for the manufacture method of lithium ion secondary battery anode of the present inventionFixed, comprising: above-mentioned lithium ion secondary battery positive electrode paste compound is coated to the work on collector bodyOrder (painting process) and the lithium ion secondary battery positive electrode paste compound of coating on collector body is enteredRow operation (drying process) dry and that formation positive pole closes material layer on collector body.

It should be noted that, lithium ion secondary battery anode of the present invention can also pass through above-mentioned lithiumIon secondary battery positive pole carries out drying-granulating with paste compound and makes compound particle and use this multipleClose particle forms anodal method of closing material layer and manufactures on collector body.

[painting process]

As above-mentioned lithium ion secondary battery positive electrode is coated to the method on collector body with paste compound,Be not particularly limited, can use known method. Specifically, as coating process, can makeBy scraper plate method, infusion process, contrary roller method, direct roller method, intagliotype, extrusion molding, spread coating etc. Now,The one side that lithium ion secondary battery positive electrode only can be coated to collector body with paste compound, also can be coated withBe distributed in two sides. The thickness of the slurry film on the collector body before dry after coating can just obtain according to dryThe utmost point closes the thickness of material layer and suitably sets.

Here, the collector body as lithium ion secondary battery positive electrode to be coated with paste compound, can useThere is electric conductivity and there is the material of electrochemistry durability. Particularly, as collector body, can useThe collector body of being made by aluminum or aluminum alloy. Now, aluminum and its alloy can be used in combination, also can be byDiverse aluminum alloy combination uses. Because aluminium and aluminium alloy have heat resistance, electrochemistry aspect is stable,Therefore be excellent current collector material.

[drying process]

Carry out dry method as the lithium ion secondary battery positive electrode on collector body with paste compound,Be not particularly limited, can use known method, for example, can enumerate and utilize warm braw, hot blast, low humidityDry, the vacuum drying of wind, utilize the seasoning of the irradiation of infrared ray, electron beam etc. By in this wiseLithium ion secondary battery positive electrode paste compound on dry collector body can just form on collector bodyThe utmost point closes material layer, thereby obtains possessing collector body and the anodal lithium ion secondary battery anode that closes material layer.

It should be noted that, also can be after drying process, use moulding press or roll squeezer etc. to close positive poleMaterial layer is implemented pressurized treatments. By pressurized treatments, the adaptation that can improve positive pole and close material layer and collector body.

Further, close the polymer that material layer comprises curability at positive pole, preferably close material at positive poleLayer makes above-mentioned polymer cure after forming.

(lithium rechargeable battery)

Lithium rechargeable battery of the present invention possesses positive pole, negative pole, electrolyte and dividing plate, and uses thisBright lithium ion secondary battery anode is as positive pole. And then, lithium rechargeable battery of the present invention due toUsed lithium ion secondary battery anode of the present invention, therefore cycle characteristics and speed characteristic excellence, isHigh performance.

As the negative pole of lithium rechargeable battery, can use and can be used as lithium ion secondary battery cathodeKnown negative pole. Particularly, as negative pole, can use and for example be made by the thin plate of lithium metalNegative pole or negative pole is closed to material layer be formed at the negative pole forming on collector body.

It should be noted that, as collector body, can use by iron, copper, aluminium, nickel, stainless steel, titanium,The collector body that the metal materials such as tantalum, gold, platinum are made. In addition, close material layer as negative pole, can use bagContaining the layer of negative electrode active material and binding material. Further, as binding material, be not particularly limited,Can use known arbitrarily material.

As electrolyte, conventionally can use supporting electrolyte is dissolved in to form in organic solvent organicElectrolyte. As supporting electrolyte, for example, can use lithium salts. As lithium salts, for example can enumerate:LiPF₆、LiAsF₆、LiBF₄、LiSbF₆、LiAlCl₄、LiClO₄、CF₃SO₃Li、C₄F₉SO₃Li、CF₃COOLi、(CF₃CO)₂NLi、(CF₃SO₂)₂NLi、(C₂F₅SO₂) NLi etc. Wherein, due to appearanceBe soluble in solvent and show high degree of dissociation, therefore preferred LiPF₆、LiClO₄、CF₃SO₃Li, excellent especiallySelect LiPF₆. It should be noted that, electrolyte can use separately a kind, also can be with arbitrary ratio groupClose use two or more. Due to conventionally exist use supporting electrolyte that degree of dissociation is higher lithium-ion electric leadThe tendency that rate is higher, therefore, can regulate lithium ion conductivity according to the kind of supporting electrolyte.

As the organic solvent using in electrolyte, as long as the solvent that can dissolve supporting electrolyte does not haveBe particularly limited, can for example preferably use: dimethyl carbonate (DMC), ethylene carbonate (EC), carbonic acidThe carbon such as diethylester (DEC), propylene carbonate (PC), butylene carbonate (BC), methyl ethyl carbonate (MEC)Esters of gallic acid; The ester such as gamma-butyrolacton, methyl formate class; The ethers such as 1,2-dimethoxy-ethane, oxolane;The sulfur-containing compound such as sulfolane, methyl-sulfoxide class; Etc.. Can also use the mixed liquor of these solvents.Wherein, because dielectric constant is high, stable potential range is wide, therefore preferably uses carbonates, enters oneStep is preferably used the mixture of ethylene carbonate and methyl ethyl carbonate.

It should be noted that, can suitably adjust the electrolytical concentration in electrolyte, for example, preferablyBe 0.5～15 quality %, more preferably 2～13 quality %, more preferably 5～10 quality %. In addition,Also can in electrolyte, add known additive, such as fluoroethylene carbonate, ethyl-methyl sulfone etc.

As dividing plate, be not particularly limited, can use for example TOHKEMY 2012-204303 public affairsThe dividing plate of recording in report. Wherein, from thickness that can attenuate dividing plate entirety, and improve thus secondary cellThereby the ratio of interior electrode active material can improve the aspect of the capacity of unit volume to be considered, preferablyThe micro-porous film being formed by the resin of TPO (polyethylene, polypropylene, polybutene, polyvinyl chloride).

The manufacture method of<lithium rechargeable battery>

With regard to lithium rechargeable battery of the present invention, can pass through for example following methods manufacture: across everyThe superimposed positive pole of plate and negative pole, and optionally it is carried out putting into electricity after curling, bending etc. according to cell shapesPond container, injects electrolyte sealing to battery case. In order to prevent the inside of lithium rechargeable batteryPressure raises, crosses the generation discharging and recharging etc., and fuse, PTC element etc. also can be set as requiredOvercurrent prevents element, expansion alloy, lead plate etc. The shape of secondary cell can for Coin shape for example,Arbitrary shape in coin shape, sheet type, cylinder type, square, platypelloid type etc.

Embodiment

Below, the present invention is specifically described, but the present invention is not limited to these in conjunction with the embodimentsEmbodiment. It should be noted that, in following explanation, " % " of expression amount and " part " are as long as no especiallyIllustrating, is quality criteria.

In embodiment and comparative example, use respectively following methods to the insoluble one-tenth component of the NMP of polymer,The dispersiveness of lithium ion secondary battery positive electrode use paste compound and viscosity stability, lithium rechargeable batteryComment with speed characteristic and the cycle characteristics of anodal peel strength and lithium rechargeable batteryValency.

The insoluble one-tenth component of<NMP>

By the 1-METHYLPYRROLIDONE solution of polymer (solid component concentration: 8%) so that dried thickDegree is that the mode of 100 μ m is injected teflon (registration mark) surface plate, has made film. By the film punching obtainingBe cut into the circular of diameter 16mm and measured weight (this weight is made as to " A "). The film that stamping-out is obtainedBe immersed in 1-METHYLPYRROLIDONE (NMP) 20ml, preserve 72 hours in 60 DEG C. Then, utilize80 object sieves filter the nmp solution (being " B " by the weight of the sieve before filtering) that has flooded film, and make it dryDry. Then, measured the weight (this weight is made as to " C ") of dried sieve. Obtained by these valuesThe insoluble one-tenth component of NMP of polymer (=(C-B)/A} × 100%).

For the lithium ion secondary battery positive electrode paste compound of preparation, adjust solid component concentration, makeMust reach target viscosities (5000 ± 200mPas) in the viscosity of measuring paste compound at 25 DEG C of temperature. SoAfter, the solid component concentration of paste compound when mensuration reaches target viscosities, and according to following benchmarkEvaluate. Can think, the solid component concentration while reaching target viscosities is higher, utilizes still lessThe decentralized medium of amount disperses the effect of each composition higher, and the dispersiveness of paste compound is higher.

A: solid component concentration is more than 80 quality %

B: solid component concentration is more than 75 quality % and lower than 80 quality %

C: solid component concentration is lower than 75 quality %

For the lithium ion secondary battery positive electrode paste compound of preparation, use Brookfield viscometer to measureViscosities il 0 under 25 DEG C of temperature, rotating speed 60rpm. To having passed through the paste compound utilization of viscosimetric analysisPlanetary-type mixer has carried out stirring for 24 hours (rotating speed: 60rpm). For the paste compound after stirring,Use Brookfield viscometer again to measure the viscosities il 1 under 25 DEG C of temperature, rotating speed 60rpm. And then, calculateGo out viscosity conservation rate Δ η=(η 1/ η 0) × 100%, and according to following benchmark evaluation paste compound stickyDegree stability. The value of viscosity conservation rate is larger, represents that the viscosity stability of paste compound is more excellent.

A: viscosity conservation rate is more than 80%

B: viscosity conservation rate is more than 70% and lower than 80%

C: viscosity conservation rate is lower than 70%

By formed anodal close material layer and through the positive pole after roll-in be cut into the square of wide 1.0cm × long 10cmShape is as test film. Then, close the surperficial sticking glass paper tape of material layer side at the positive pole of test film. Now,Glass paper tape uses the material specifying in JISZ1522. Then, glass paper tape is being fixed on to testing standState under, with the speed of 50mm/ minute by test film from one distolateral towards another distolateral tearing, measureStress now. Mensuration is carried out 10 times, obtains the mean value of stress, and sets it as peel strength (N/m),Evaluate according to following benchmark. Peel strength is larger, represents that positive pole closes material layer with respect to current collectionThe adaptation of body is more excellent.

A: peel strength is more than 30N/m

B: peel strength is more than 10N/m and lower than 30N/m

C: peel strength is lower than 10N/m

To 10 batteries of lithium rechargeable battery of making, carry out respectively under the condition of 25 DEG C of temperatureConstant current charge with 0.2C is discharged to discharging and recharging of 3.0V to 4.2V and with the constant current of 0.2CCirculation and under the condition of 25 DEG C of temperature with the constant current charge of 0.2C to 4.2V and with 1.0C'sConstant current is discharged to the charge and discharge cycles of 3.0V. Electric discharge while calculating 1.0C with percentile formRatio (=(discharge capacity when 1.0C of the discharge capacity (mean value) of capacity (mean value) during with respect to 0.2CDischarge capacity when/0.2C) × 100%), set it as charge-discharge velocity characteristic, and according to following benchmark evaluationSpeed characteristic. The value of charge-discharge velocity characteristic is larger, represents that internal resistance is less, more can realize highSpeed discharges and recharges.

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

B: charge-discharge velocity characteristic is more than 75% and lower than 80%

C: charge-discharge velocity characteristic is more than 70% and lower than 75%

D: charge-discharge velocity characteristic is lower than 70%

For 10 batteries of lithium rechargeable battery of making, under the condition of 25 DEG C of temperature, will be with600mA charges to cell voltage and reaches 4.4V and be discharged to cell voltage with 600mA and reach 3V'sOperation repeats 100 times. And then, obtain the discharge capacity (mean value) of the 100th time with respect to the 1stRatio (charge/discharge capacity conservation rate=(discharge capacity/1st of the 100th time of inferior discharge capacity (mean value)Inferior discharge capacity) × 100%), and evaluate according to following benchmark. Charge/discharge capacity conservation rateValue larger, represent cycle characteristics more excellent.

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

B: charge/discharge capacity conservation rate is more than 70% and lower than 80%

C: charge/discharge capacity conservation rate is more than 60% and lower than 70%

D: charge/discharge capacity conservation rate is lower than 60%

(embodiment 1)

The preparation of<fluoropolymer X1>

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

The preparation of<polymer Y1>

To adding 240 parts of ion exchange waters, propylene as nitrile group-containing monomer in the autoclave of belt stirrerNitrile (AN) 25 mass parts, as can with the butadiene of the monomer of nitrile group-containing monomer copolymerization (BD) 60 qualityPart and butyl acrylate (BA) 15 mass parts, 0.3 part of the potassium peroxydisulfate as polymerization initiator, conduct breast1.6 parts of the NaLSs of agent, as 0.05 part of the tertiary lauryl mercaptan of molecular weight adjusting agent,After fully stirring and utilizing nitrogen displacement inside, in 70 DEG C heat 3 hours, 80 DEG C heat 2 hours andCarry out polymerization, obtained the aqueous dispersions of polymer. Wherein, the polymerization of being obtained by solid component concentration turnsRate is 96%.

To add ion exchange water and solid component concentration has been adjusted to 12 matter with respect to resulting polymers400 ml solns of amount % are put in 1 liter of autoclave of belt stirrer, logical nitrogen 10 minutes and incite somebody to actionAfter dissolved oxygen in solution is removed, as catalyst for hydrogenation, acid chloride 75mg is dissolved in and is addedHaving added molal quantity is the water 180ml of the nitric acid of 4 times of Pd, and adds in autoclave. Utilize hydrogenTo carrying out in system after twice displacement, utilize pressurized with hydrogen under the state of 3MPa by autoclaveContent is heated to 50 DEG C, has carried out 6 hours hydrogenation reactions (being called " first stage hydrogenation reaction ").

Next, make autoclave return to atmospheric pressure, be further used as catalyst for hydrogenation and by acetic acidPalladium 25mg is dissolved in that to have added molal quantity be the water 60ml of the nitric acid of 4 times of Pd, and adds high pressure toIn still. Utilize hydrogen to carrying out in system after twice displacement, at the state that utilizes pressurized with hydrogen to 3MPaLower content in autoclave is heated to 50 DEG C, carried out 6 hours hydrogenation reactions and (be called " second stageHydrogenation reaction ").

Then, make content return to normal temperature, after making to become nitrogen atmosphere in system, use rotation to steamSend out instrument and concentrate until solid component concentration reaches 40%, obtained the aqueous dispersions of polymer Y1.In addition, in 100 parts of the aqueous dispersions of this polymer Y1, add the NMP of 320 parts, under reduced pressure makeWater evaporates, and has obtained the nmp solution of polymer Y1.

It should be noted that, the insoluble one-tenth component of NMP of polymer Y1 is 2 quality %.

The preparation of<polymer Z1>

In the autoclave of belt stirrer, add ion exchange water 164 mass parts, conduct (methyl) acrylic acid2-EHA (2EHA) 59.5 mass parts of alkyl ester monomer, the list that conduct has carboxylic acid groupMethacrylic acid (MAA) 20 mass parts of body, as acrylonitrile (AN) 20 mass parts of nitrile group-containing monomer,As 2-acrylamide-2-methyl propane sulfonic (AMPS) 0.5 mass parts, the conduct with sulfonic monomer0.3 part of the potassium peroxydisulfate of polymerization initiator, as 1.6 parts of the NaLSs of emulsifying agent, fully stirAfter mixing, heat 3 hours, 80 DEG C and heat 2 hours and carry out polymerization in 70 DEG C, obtained polymerThe aqueous dispersions of Z1. Wherein, the polymerisation conversion of being obtained by solid component concentration is 96%. Next,In 100 parts of this aqueous dispersions, add 500 parts of 1-METHYLPYRROLIDONEs, under reduced pressure make water and all81 parts of evaporations of residual monomer and 1-METHYLPYRROLIDONE, the concentration that has obtained polymer Z1 is 8The nmp solution of quality %.

It should be noted that, the insoluble one-tenth component of NMP of polymer Z1 is 10 quality %.

The preparation of paste compound for<lithium ion secondary battery positive electrode>

Using the cobalt acid lithium LCO (LiCoO as the volume average particle size 12 μ m of positive active material₂)100Part, as the Ketjen black of conductive material (manufacture of Lion company, EC300J, particular oils oven process carbon dust shape product,Number average bead diameter 40nm, BET specific area 800m²/ g) 1.5 parts, count 1.2 with solid constituent a great deal ofPart fluoropolymer X1 nmp solution, count the polymer of 0.15 part with solid constituent a great deal ofThe nmp solution of Y1, with solid constituent a great deal of count the polymer Z1 of 0.15 part nmp solution,And appropriate NMP, utilize planetary-type mixer to stir, so that it is at 25 DEG C of temperature, rotating speedViscosity (utilizing Brookfield viscometer to measure) under 60rpm is that the mode of 5000 ± 200mPas has been prepared positive poleUse paste compound. The solid component concentration of the paste compound obtaining is that 81 quality %, viscosity are5100mPa·s。

And then dispersiveness and viscosity stability to the paste compound obtaining are evaluated. Result asShown in table 1.

The making of<lithium ion secondary battery anode>

As collector body, prepare the aluminium foil of thickness 15 μ m. Then, so that dried coating weight be20mg/cm²Mode lithium ion secondary battery positive electrode is coated to the two sides of aluminium foil with paste compound,And in 60 DEG C dry 20 minutes, in 120 DEG C dry 20 minutes. Afterwards, carry out 2 hours in 150 DEG CHeat treated, has obtained anodal former film. Utilize roll squeezer to roll former this positive pole film, made byDensity is 3.7g/cm³Positive pole close the sheet positive pole that material layer and aluminium foil form. And then, sheet positive pole is cutCut for wide 4.8mm, long 50cm, as lithium ion secondary battery anode.

Then, evaluated the peel strength of gained positive pole. Result is as shown in table 1.

The making of<lithium ion secondary battery cathode>

Using as the spherical Delanium of negative electrode active material (volume average particle size: 12 μ m) 90 parts andSiO_X(volume average particle size: 10 μ are mixture, suitable with solid constituent as binding material of 10 parts m)Amount counts the aqueous dispersions of the styrene butadiene polymer of 1 part, as the carboxymethyl cellulose of thickener1 part and stir by planetary-type mixer as the appropriate water of decentralized medium, prepared lithium fromSub-secondary battery negative pole paste compound.

Then,, as collector body, prepared the Copper Foil of thickness 15 μ m. Then, so that dried paintingCloth amount is 10mg/cm²Mode above-mentioned lithium ion secondary battery negative pole is coated to copper with paste compoundThe two sides of paper tinsel, and in 60 DEG C dry 20 minutes, in 120 DEG C dry 20 minutes. Afterwards, in 150 DEG CCarry out 2 hours heat treated, obtained the former film of negative pole. Former this negative pole film is rolled with roll squeezer,Having made by density is 1.8g/cm³Negative pole close the sheet negative pole that material layer and Copper Foil form. Then, by sheetShape negative pole is cut into wide 5.0mm, long 52cm, as lithium ion secondary battery cathode.

The making of<lithium rechargeable battery>

Use the core of diameter 20mm, by lithium ion secondary battery anode and the lithium ion secondary electricity madeReeling across dividing plate (the polypropylene microporous films of thickness 20 μ m) with negative pole in pond, obtains coiling body.The coiling body obtaining is reached to 4.5mm from a direction with speed compression to the thickness of 10mm/ second. NeedIllustrate, the coiling body after compression is to overlook ellipse, the ratio (major diameter/minor axis) of its major diameter and minor axisBe 7.7.

In addition, prepare nonaqueous electrolytic solution (composition: the LiPF of concentration 1.0M₆(solvent is in carbonic acid Asia to solutionIn the mixed solvent of ethyl ester/methyl ethyl carbonate=3/7 (mass ratio), add 5 quality % fluoroethylene carbonates andThe mixture becoming, as additive, has added 2 volume % vinylene carbonates)).

Then, the coiling body after compression is contained in to given aluminium together with the nonaqueous electrolytic solution of 3.2gIn lamination system housing. Then, will be connected in the nickel down-lead of lithium ion secondary battery cathode and connectThe aluminum lead that is connected to lithium ion secondary battery anode is connected to given position, utilizes afterwards heat to housingPeristome seal, made lithium rechargeable battery. This lithium rechargeable battery is widthThe bag shape of 35mm, height 48mm, thickness 5mm, the nominal capacity of battery is 700mAh. ForGained lithium rechargeable battery has carried out the evaluation of speed characteristic and cycle characteristics. The results are shown in table 1.

(embodiment 2～3)

The use level of the conductive material when lithium ion secondary battery positive electrode is prepared with paste compoundChange to respectively outside 1.0 parts, 2.0 parts, manufactured similarly to Example 1 lithium rechargeable batteryAnodal with paste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode and lithium fromSub-secondary cell, and evaluate. Result is as shown in table 1.

(embodiment 4～5)

The conductive material using when lithium ion secondary battery positive electrode is prepared with paste compound respectivelyChange to acetylene black (Denki Kagaku Kogyo kabushiki's manufacture, AB35, DENKABLACK powdery product, numberAll particle diameter 35nm, BET specific area 68m²/ g) and Ketjen black (manufacture of Lion company, EC300J, spyDifferent Audit For Process carbon dust shape product, number average bead diameter 40nm, BET specific area 800m²/ mixture (BET g)Specific area 600m²/ g), Ketjen black (manufacture of Lion company, EC600J, number average bead diameter 40nm, BETSpecific area 1270m²/ g) outside, manufactured similarly to Example 1 lithium ion secondary battery positive electrode usePaste compound, lithium ion secondary battery anode, lithium ion secondary battery cathode and lithium ion secondaryBattery, and evaluate. Result is as shown in table 1.

(embodiment 6～8)

The amount of the polymer using when lithium ion secondary battery positive electrode is prepared with paste compound asOutside changing shown in table 1, make similarly to Example 1 slurry for lithium ion secondary battery positive electrodeFeed composition, lithium ion secondary battery anode, lithium ion secondary battery cathode and lithium ion secondary electricityPond, and evaluate. Result is as shown in table 1.

(embodiment 9)

Except replacing polymer Y1 to use the polymer Y2 of preparation as described below, with embodiment 1Similarly manufactured paste compound for lithium ion secondary battery positive electrode, lithium ion secondary battery anode,Lithium ion secondary battery cathode and lithium rechargeable battery, evaluate. Result is as shown in table 1.

The preparation of<polymer Y2>

Be that the amount of 15 mass parts, butadiene (BD) is 75 mass parts, third except making the amount of acrylonitrile (AN)The amount of olefin(e) acid butyl ester (BA) is outside 10 mass parts, has similarly prepared polymer Y2 with polymer Y1.

It should be noted that, the insoluble one-tenth component of NMP of polymer Y2 is 15 quality %.

(embodiment 10)

Except replacing polymer Y1 to use the polymer Y3 of preparation as described below, with embodiment 1Similarly manufactured paste compound for lithium ion secondary battery positive electrode, lithium ion secondary battery anode,Lithium ion secondary battery cathode and lithium rechargeable battery, evaluate. Result is as shown in table 1.

The preparation of<polymer Y3>

Be that the amount of 30 mass parts, butadiene (BD) is 50 mass parts, third except making the amount of acrylonitrile (AN)The amount of olefin(e) acid butyl ester (BA) is outside 20 mass parts, has similarly prepared polymer Y3 with polymer Y1.

It should be noted that, the insoluble one-tenth component of NMP of polymer Y3 is 1 quality %.

(embodiment 11)

Except replacing polymer Z1 to use the polymer Z2 of preparation as described below, with embodiment 1Similarly manufactured paste compound for lithium ion secondary battery positive electrode, lithium ion secondary battery anode,Lithium ion secondary battery cathode and lithium rechargeable battery, evaluate. Result is as shown in table 1.

The preparation of<polymer Z2>

Be 54.5 mass parts, methacrylic acid (MAA) except making the amount of 2-EHA (2EHA)Amount be outside 25 mass parts, similarly prepared polymer Z2 with polymer Z1.

It should be noted that, the insoluble one-tenth component of NMP of polymer Z2 is 4 quality %.

(embodiment 12)

Except replacing polymer Z1 to use the polymer Z3 of preparation as described below, with embodiment 1Similarly manufactured paste compound for lithium ion secondary battery positive electrode, lithium ion secondary battery anode,Lithium ion secondary battery cathode and lithium rechargeable battery, evaluate. Result is as shown in table 1.

The preparation of<polymer Z3>

Be 69.5 mass parts, methacrylic acid (MAA) except making the amount of 2-EHA (2EHA)Amount be that the amount of 15 mass parts, acrylonitrile (AN) is outside 15 mass parts, with polymer Z1 similarlyPrepare polymer Z3.

It should be noted that, the insoluble one-tenth component of NMP of polymer Z3 is 13 quality %.

(embodiment 13)

Except replacing polymer Z1 to use the polymer Z4 of preparation as described below, with embodiment 1Similarly manufactured paste compound for lithium ion secondary battery positive electrode, lithium ion secondary battery anode,Lithium ion secondary battery cathode and lithium rechargeable battery, evaluate. Result is as shown in table 1.

The preparation of<polymer Z4>

Be 79.5 mass parts, methacrylic acid (MAA) except making the amount of 2-EHA (2EHA)Amount be that the amount of 10 mass parts, acrylonitrile (AN) is outside 10 mass parts, with polymer Z1 similarlyPrepare polymer Z4.

It should be noted that, the insoluble one-tenth component of NMP of polymer Z4 is 20 quality %.

(comparative example 1)

The conductive material using when lithium ion secondary battery positive electrode is prepared with paste compound changesFor acetylene black (all grains of Denki Kagaku Kogyo kabushiki's manufacture, AB35, DENKABLACK powdery product, numberFootpath 35nm, BET specific area 68m²/ g) and Ketjen black (manufacture of Lion company, EC300J, particular oilsOven process carbon dust shape product, number average bead diameter 40nm, BET specific area 800m²(BET is than table for/mixture g)Area 350m²/ g) outside, manufactured similarly to Example 1 lithium ion secondary battery positive electrode slurry groupCompound, lithium ion secondary battery anode, lithium ion secondary battery cathode and lithium rechargeable battery,And evaluate. Result is as shown in table 2.

(comparative example 2～3)

The amount of the polymer using when lithium ion secondary battery positive electrode is prepared with paste compound asOutside changing shown in table 2, manufacture similarly to Example 1 slurry for lithium ion secondary battery positive electrodeFeed composition, lithium ion secondary battery anode, lithium ion secondary battery cathode and lithium ion secondary electricityPond, and evaluate. Result is as shown in table 2.

(comparative example 4)

Use the polymer Y4 of preparation as described below except replacing polymer Y1, with enforcementExample 1 has similarly been manufactured paste compound for lithium ion secondary battery positive electrode, lithium rechargeable battery is just being usedThe utmost point, lithium ion secondary battery cathode and lithium rechargeable battery, and evaluate. Result is as table 2Shown in.

The preparation of<polymer Y4>

Be that the amount of 5 mass parts, butadiene (BD) is 85 mass parts, third except making the amount of acrylonitrile (AN)The amount of olefin(e) acid butyl ester (BA) is outside 10 mass parts, has similarly prepared polymer Y4 with polymer Y1.

It should be noted that, the insoluble one-tenth component of NMP of polymer Y4 is 55 quality %.

(comparative example 5)

Use the polymer Y5 of preparation as described below except replacing polymer Y1, with enforcementExample 1 has similarly been manufactured paste compound for lithium ion secondary battery positive electrode, lithium rechargeable battery is just being usedThe utmost point, lithium ion secondary battery cathode and lithium rechargeable battery, and evaluate. Result is as table 2Shown in.

The preparation of<polymer Y5>

Be that the amount of 55 mass parts, butadiene (BD) is 35 mass parts, third except making the amount of acrylonitrile (AN)The amount of olefin(e) acid butyl ester (BA) is outside 10 mass parts, has similarly prepared polymer Y5 with polymer Y1.

It should be noted that, the insoluble one-tenth component of NMP of polymer Y5 is 0.5 quality %.

(comparative example 6)

Use the polymer Z5 of preparation as described below except replacing polymer Z1, with embodiment1 similarly manufactured paste compound for lithium ion secondary battery positive electrode, lithium ion secondary battery anode,Lithium ion secondary battery cathode and lithium rechargeable battery, and evaluate. Result is as shown in table 2.

The preparation of<polymer Z5>

Be 44.5 mass parts, methacrylic acid (MAA) except making the amount of 2-EHA (2EHA)Amount be outside 35 mass parts, similarly prepared polymer Z5 with polymer Z1.

It should be noted that, the insoluble one-tenth component of NMP of polymer Z5 is 2 quality %.

(comparative example 7)

Use the polymer Z6 of preparation as described below except replacing polymer Z1, with embodiment1 similarly manufactured paste compound for lithium ion secondary battery positive electrode, lithium ion secondary battery anode,Lithium ion secondary battery cathode and lithium rechargeable battery, and evaluate. Result is as shown in table 2.

The preparation of<polymer Z6>

Be 94.5 mass parts, methacrylic acid (MAA) except making the amount of 2-EHA (2EHA)Amount be 5 mass parts and do not coordinate outside acrylonitrile (AN), similarly prepared poly-with polymer Z1Compound Z6.

It should be noted that, the insoluble one-tenth component of NMP of polymer Z6 is 25 quality %.

Known according to table 1 and table 2, the slurry of the paste compound of embodiment 1～13 and comparative example 3～6Composition is compared, and both are excellent for dispersiveness and viscosity stability. In addition we know, embodiment 1～13 justCompared with the positive pole of the utmost point and comparative example 3,4,6,7, peel strength excellence. In addition known, embodiment 1～13The lithium rechargeable battery of lithium rechargeable battery and comparative example 1～7 compared with, cycle characteristics and speed spyProperty both are excellent.

Especially, known according to the embodiment 1～3 of table 1, by adjusting the use level of conductive material, canTo take into account the dispersiveness of paste compound and viscosity stability and lithium rechargeable battery with high levelCycle characteristics and speed characteristic.

In addition, known according to the embodiment 1 and 4～5 of table 1, by adjusting the BET ratio of conductive materialSurface area, can take into account with high level dispersiveness and viscosity stability and the lithium ion of paste compoundThe cycle characteristics of secondary cell and speed characteristic.

Further, known according to the embodiment 1 and 6～8 of table 1, by adjusting the mixing ratio of polymer,Can take into account with high level dispersiveness and viscosity stability and the lithium rechargeable battery of paste compoundCycle characteristics and speed characteristic.

In addition, known according to the embodiment 1 and 9～13 of table 1, by adjusting the composition of polymer, canTo take into account the dispersiveness of paste compound and viscosity stability and lithium rechargeable battery with high levelCycle characteristics and speed characteristic.

Industrial applicibility

According to the present invention, can further improve the performance of lithium rechargeable battery, especially cycle characteristicsAnd speed characteristic, and can provide the lithium ion secondary battery positive electrode slurry group of viscosity stability excellenceCompound. In addition, according to the present invention, can provide can further improve lithium rechargeable battery performance,Especially the lithium ion secondary battery anode of cycle characteristics and speed characteristic. In addition, according to the present invention,High performance lithium rechargeable battery can be provided.

Claims

1. a lithium ion secondary battery positive electrode paste compound, it comprises: positive active material,Conductive material, binding material and organic solvent,

The BET specific area of described conductive material is 400m²More than/g,

Described binding material comprises:

(1) fluoropolymer X,

(2) polymer Y, the nitrile group-containing more than it contains 10 quality % and below 50 quality %Monomeric unit and

(3) polymer Z, (methyl) third more than it contains 50 quality % and below 90 quality %Olefin(e) acid alkyl ester monomer unit,

The ratio of fluoropolymer X described in described binding material is more than 50 quality % and 95 quality %Below.

2. lithium ion secondary battery positive electrode paste compound according to claim 1, wherein,The content of described fluoropolymer X with respect to the ratio (X/Y) of the content of described polymer Y with quality-baseStandard is counted 9.5/0.5～5.5/4.5.

3. lithium ion secondary battery positive electrode paste compound according to claim 1 and 2, itsIn, the content of described fluoropolymer X with respect to the ratio (X/Z) of the content of described polymer Z with matterAmount benchmark is counted 9.5/0.5～5.5/4.5.

4. combine with slurry according to the lithium ion secondary battery positive electrode described in any one in claim 1～3Thing, wherein, described polymer Z also contains containing acidic-group monomeric unit.

5. lithium ion secondary battery positive electrode paste compound according to claim 4, wherein,The described acidic-group monomer list that contains more than described polymer Z contains 10 quality % and below 30 quality %Unit.

6. combine with slurry according to the lithium ion secondary battery positive electrode described in any one in claim 1～5Thing, wherein, the insoluble one-tenth component of described polymer Y in 1-METHYLPYRROLIDONE be 5 quality % withUnder.

7. combine with slurry according to the lithium ion secondary battery positive electrode described in any one in claim 1～6Thing, wherein, the insoluble one-tenth component of described polymer Z in 1-METHYLPYRROLIDONE be 50 quality % withUnder.

8. a lithium ion secondary battery anode, it possesses right to use and requires 1～7 on collector bodyLithium ion secondary battery positive electrode described in middle any one closes material layer with the positive pole that paste compound forms.

9. a lithium rechargeable battery, it comprises:

Lithium ion secondary battery anode claimed in claim 8,

Negative pole,

Electrolyte and

Dividing plate.