WO2019017317A1 - Liant pour électrode de batterie secondaire à électrolyte non aqueux, et application associée - Google Patents

Liant pour électrode de batterie secondaire à électrolyte non aqueux, et application associée Download PDF

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Publication number
WO2019017317A1
WO2019017317A1 PCT/JP2018/026659 JP2018026659W WO2019017317A1 WO 2019017317 A1 WO2019017317 A1 WO 2019017317A1 JP 2018026659 W JP2018026659 W JP 2018026659W WO 2019017317 A1 WO2019017317 A1 WO 2019017317A1
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mass
binder
secondary battery
electrolyte secondary
crosslinked polymer
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PCT/JP2018/026659
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English (en)
Japanese (ja)
Inventor
朋子 仲野
直彦 斎藤
剛史 長谷川
松崎　英男
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東亞合成株式会社
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Priority to JP2019531025A priority Critical patent/JP7078048B2/ja
Publication of WO2019017317A1 publication Critical patent/WO2019017317A1/fr
Priority to JP2022080181A priority patent/JP7160222B2/ja

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1393—Processes of manufacture of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1395—Processes of manufacture of electrodes based on metals, Si or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a binder for non-aqueous electrolyte secondary battery electrodes that can be used for lithium ion secondary batteries and the like, applications thereof, and a method for producing a carboxyl group-containing crosslinked polymer or a salt thereof used for the binder.
  • non-aqueous electrolyte secondary battery for example, a lithium ion secondary battery is well known.
  • the non-aqueous electrolyte secondary battery electrode is produced by applying and drying a composition for forming an electrode mixture layer containing an active material, a binder and the like on a current collector.
  • a binder used for the negative electrode mixture layer composition an aqueous binder containing styrene butadiene rubber (SBR) latex and carboxymethyl cellulose (CMC) is used.
  • SBR styrene butadiene rubber
  • CMC carboxymethyl cellulose
  • the binder containing acrylic acid type polymer aqueous solution or aqueous dispersion is known as a binder which is excellent in dispersibility and binding property.
  • NMP N-methyl-2-pyrrolidone
  • PVDF polyvinylidene fluoride
  • Patent Document 1 discloses a binder containing a crosslinked polymer (salt) having an ethylenic unsaturated carboxylic acid monomer as a constituent monomer and having a specific aqueous dispersion viscosity at a degree of neutralization of 90 mol%.
  • Patent Document 2 discloses a binder which is a crosslinked polymer having a carboxyl group or a salt thereof, and which has a sufficiently small particle size when dispersed in brine after neutralization.
  • the binders disclosed in Patent Documents 1 and 2 both have excellent binding properties, but with the improvement of the performance of lithium ion secondary batteries, there is an increasing demand for binders having higher binding power.
  • it is effective to increase the molecular weight of the polymer to be a binder.
  • it is known that it is effective to carry out a polymerization reaction under conditions of high monomer concentration.
  • the polymer obtained is excellent in dispersion stability, and in the electrode composition, those which exist as polymer particles of small particles without being united are more excellent in uniform dispersion in the electrode mixture layer.
  • the adhesion point with the active material and the like increases, it is considered preferable also from the viewpoint of improving the binding property.
  • polymerizing by the high monomer concentration which exceeds 20 mass% is disclosed in the Example as for the binder of patent document 1, room for the further improvement in binding property is disclosed. was there. It is presumed that the particle size of the crosslinked polymer is not sufficiently small.
  • the binder described in Patent Document 2 also exhibits excellent binding properties, the monomer concentration at the time of polymerization of each crosslinked polymer disclosed in the examples is about 10 mass% or so is there.
  • the present disclosure also provides a composition for a non-aqueous electrolyte secondary battery electrode mixture layer obtained using the binder and a non-aqueous electrolyte secondary battery electrode.
  • the present inventors have intensively studied to solve the above problems, and as a result, a crosslinked polymer obtained by polymerizing a monomer component containing an ethylenically unsaturated carboxylic acid monomer in the presence of an organic amine compound or The binder containing the salt was well bound to the electrode active material and the like, and it was found that the electrode mixture layer containing the binder exhibits excellent binding properties.
  • the present invention has been completed based on these findings.
  • a binder for a non-aqueous electrolyte secondary battery electrode containing a crosslinked polymer or a salt thereof The non-aqueous electrolyte secondary battery, wherein the crosslinked polymer comprises a structural unit derived from an ethylenically unsaturated carboxylic acid monomer, and is obtained by polymerizing a monomer component in the presence of an organic amine compound. Binder for electrodes.
  • the organic amine compound has a value (C / N) represented by a ratio of the number of carbon atoms to the number of nitrogen atoms present in the organic amine compound of 3 or more. Binder for secondary battery electrodes.
  • a method for producing a crosslinked polymer or a salt thereof used as a binder for a non-aqueous electrolyte secondary battery electrode A method comprising a polymerization step of polymerizing a monomer component containing an ethylenically unsaturated carboxylic acid monomer by a precipitation polymerization method in the presence of an organic amine compound.
  • a composition for a non-aqueous electrolyte secondary battery electrode mixture layer comprising the binder according to any one of the above [1] to [4], an active material and water.
  • a non-aqueous electrolyte secondary battery electrode comprising a mixture layer formed of the composition for a non-aqueous electrolyte secondary battery electrode mixture layer according to the above [6] or [7] on the surface of a current collector .
  • the binder for a non-aqueous electrolyte secondary battery electrode of the present invention exhibits excellent binding to electrode active materials and the like. Moreover, the said binder can exhibit favorable adhesiveness also with a collector. For this reason, while being excellent in binding property, the electrode mixture layer containing the said binder and the electrode provided with this can maintain the integrity. For this reason, it is possible to suppress deterioration of the electrode mixture layer due to volume change and shape change of the active material accompanying charge and discharge, and it is possible to obtain a secondary battery with high durability (cycle characteristics).
  • the composition for a non-aqueous electrolyte secondary battery electrode mixture layer of the present invention has a good binding property to the electrode material and a good adhesion to the current collector, the electrode mixture layer having a good integrity can be obtained. It is possible to form a non-aqueous electrolyte secondary battery electrode with good electrode characteristics.
  • the binder for a non-aqueous electrolyte secondary battery electrode of the present invention contains a crosslinked polymer or a salt thereof, and can be made into an electrode mixture layer composition by mixing with an active material and water.
  • the composition described above may be in the form of a slurry capable of being coated on the current collector, or may be prepared as a wet powder to be able to cope with pressing on the surface of the current collector.
  • the non-aqueous electrolyte secondary battery electrode of the present invention can be obtained by forming a mixture layer formed of the above composition on the surface of a current collector such as a copper foil or an aluminum foil.
  • (meth) acrylic means acrylic and / or methacrylic
  • (meth) acrylate means acrylate and / or methacrylate
  • (meth) acryloyl group means an acryloyl group and / or a methacryloyl group.
  • the binder of the present invention comprises a crosslinked polymer having a carboxyl group or a salt thereof.
  • the crosslinked polymer having a carboxyl group or a salt thereof may have a structural unit derived from an ethylenically unsaturated carboxylic acid.
  • the crosslinked polymer can have a structural unit derived from an ethylenically unsaturated carboxylic acid monomer (hereinafter, also referred to as "component (a)").
  • component (a) ethylenically unsaturated carboxylic acid monomer
  • the component (a) can be introduced into a crosslinked polymer, for example, by polymerizing a monomer containing an ethylenically unsaturated carboxylic acid monomer. In addition, it can also be obtained by (co) polymerizing a (meth) acrylic acid ester monomer and then hydrolyzing it. In addition, after (meth) acrylamide and (meth) acrylonitrile are polymerized, they may be treated with a strong alkali, or a method of reacting an acid anhydride with a polymer having a hydroxyl group may be used.
  • Ethylenically unsaturated carboxylic acid monomers include (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid; (meth) acrylamidoalkyls such as (meth) acrylamidohexanoic acid and (meth) acrylamidododecanoic acid Carboxylic acid; ethylenically unsaturated monomers having a carboxyl group such as monohydroxyethyl (meth) acrylate, ⁇ -carboxy-caprolactone mono (meth) acrylate, ⁇ -carboxyethyl (meth) acrylate, etc. And the like.
  • Alkali neutralized products may be mentioned, and one of them may be used alone, or two or more may be used in combination.
  • a polymer having a long primary chain length is obtained because the polymerization rate is large, and a compound having an acryloyl group as a polymerizable functional group is preferable, and acrylic acid is particularly preferable in that the binding ability of the binder is good. is there.
  • acrylic acid is used as the ethylenically unsaturated carboxylic acid monomer, a polymer having a high carboxyl group content can be obtained.
  • content of (a) component in a crosslinked polymer is not specifically limited, For example, 10 mass% or more and 100 mass% or less can be contained with respect to the total structural unit of a crosslinked polymer.
  • the lower limit is, for example, 20% by mass or more, for example, 30% by mass or more, and for example, 40% by mass or more.
  • the lower limit may be 50% by mass or more, for example, 60% by mass or more, for example 70% by mass or more, and for example 80% by mass or more.
  • the upper limit is, for example, 99% by mass or less, for example, 98% by mass or less, and for example, 95% by mass or less, and for example, 90% by mass or less.
  • the range may be a combination of such lower limit and upper limit as appropriate, and is, for example, 10% by mass or more and 100% by mass or less, and for example, 20% by mass or more and 100% by mass or less It is 30 mass% or more and 100 mass% or less, and can be, for example, 50 mass% or more and 99 mass% or less.
  • the crosslinked polymer of the present invention contains, in addition to the component (a), a structural unit derived from another ethylenically unsaturated monomer copolymerizable therewith (hereinafter, also referred to as "component (b)"). be able to.
  • component (b) for example, an ethylenically unsaturated monomer compound having an anionic group other than a carboxyl group such as a sulfonic acid group and a phosphoric acid group, or a nonionic ethylenically unsaturated monomer etc.
  • component (b) for example, an ethylenically unsaturated monomer compound having an anionic group other than a carboxyl group such as a sulfonic acid group and a phosphoric acid group, or a nonionic ethylenically unsaturated monomer etc.
  • component (b) for example, an ethylenically unsaturated monomer compound having an anionic group other than a
  • These structural units are an ethylenically unsaturated monomer compound having an anionic group other than a carboxyl group such as a sulfonic acid group and a phosphoric acid group, or a monomer containing a nonionic ethylenically unsaturated monomer Can be introduced by copolymerization.
  • a structural unit derived from a nonionic ethylenic unsaturated monomer is preferable from the viewpoint that an electrode with good flexibility is obtained, and the binding property of the binder is excellent.
  • (meth) acrylamide and derivatives thereof are preferable.
  • a structural unit derived from a hydrophobic ethylenic unsaturated monomer having a solubility in water of 1 g / 100 ml or less is introduced as the component (b), a strong interaction with the electrode material can be exhibited, Good binding can be exhibited for the active material. This is preferable because it is possible to obtain a firm and integral electrode mixture layer.
  • a structural unit derived from an alicyclic structure-containing ethylenic unsaturated monomer is particularly preferred.
  • the proportion of the component (b) can be 0% by mass or more and 90% by mass or less with respect to the total structural units of the crosslinked polymer.
  • the proportion of the component (b) may be 1% by mass or more and 60% by mass or less, 2% by mass or more and 50% by mass or less, and 5% by mass or more and 40% by mass or less 10 mass% or more and 30 mass% or less may be sufficient.
  • the component (b) is contained in an amount of 1% by mass or more based on the total structural units of the crosslinked polymer, the affinity to the electrolytic solution is improved, and therefore, the effect of improving lithium ion conductivity can also be expected.
  • Examples of (meth) acrylamide derivatives include N-alkyl (eg, isopropyl (meth) acrylamide, t-butyl (meth) acrylamide, Nn-butoxymethyl (meth) acrylamide, N-isobutoxymethyl (meth) acrylamide, etc.) Meta) acrylamide compounds; N, N-dialkyl (meth) acrylamide compounds such as dimethyl (meth) acrylamide, diethyl (meth) acrylamide, etc. may be mentioned, and one of them may be used alone, or two You may use combining the above.
  • N-alkyl eg, isopropyl (meth) acrylamide, t-butyl (meth) acrylamide, Nn-butoxymethyl (meth) acrylamide, N-isobutoxymethyl (meth) acrylamide, etc.
  • Meta acrylamide compounds
  • N, N-dialkyl (meth) acrylamide compounds such as dimethyl (meth) acryl
  • Examples of the alicyclic structure-containing ethylenic unsaturated monomer include cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, methyl cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, (meth ) (Meth) acrylic acid cycloalkyl ester which may have an aliphatic substituent such as cyclodecyl acrylate and (meth) acrylic acid cyclododecyl; isobornyl (meth) acrylate; adamantyl (meth) acrylate; ) Dicyclopentenyl acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and cyclohexane dimethanol mono (meth) acrylate and cyclodecane di methanol mono (meth) acryl
  • (meth) acrylic acid ester As another nonionic ethylenically unsaturated monomer, you may use (meth) acrylic acid ester, for example.
  • (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate and 2-ethylhexyl (meth) acrylate Meta) acrylic acid alkyl ester compounds;
  • (Meth) acrylic acid aralkyl ester compounds such as phenyl (meth) acrylate, phenylmethyl (meth) acrylate and phenylethyl (meth) acrylate;
  • (Meth) acrylic acid alkoxy alkyl ester compounds such as 2-methoxyethyl (meth) acrylic acid and ethoxyethyl (meth) acrylic acid;
  • (Meth) acrylic acid hydroxyalkyl ester compounds such as hydroxye
  • compounds having an ether bond such as (meth) acrylate alkoxyalkyls such as 2-methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate, are preferable and 2-methoxyethyl (meth) acrylate are more preferable.
  • nonionic ethylenically unsaturated monomers a compound having an acryloyl group is preferable in that a polymer having a long primary chain length can be obtained because the polymerization rate is fast and the binding ability of the binder is good.
  • the compound whose glass transition temperature (Tg) of a homopolymer is 0 degrees C or less at the point which the bending resistance of the electrode obtained becomes favorable is preferable.
  • the crosslinked polymer may be a salt.
  • Types of salts are not particularly limited, but alkali metal salts such as lithium, sodium and potassium; alkaline earth metal salts such as calcium salts and barium salts; other metal salts such as magnesium salts and aluminum salts; ammonium salts and organic An amine salt etc. are mentioned.
  • alkali metal salts and magnesium salts are preferable, and alkali metal salts are more preferable, from the viewpoint that an adverse effect on battery characteristics hardly occurs.
  • the crosslinking method in the crosslinked polymer of the present invention is not particularly limited, and an embodiment by the following method is exemplified. 1) Copolymerization of a crosslinkable monomer 2) Use of chain transfer to polymer chain during radical polymerization 3) After synthesis of a polymer having a reactive functional group, a crosslinker is added if necessary and post-crosslinking Among the above, the method by the copolymerization of a crosslinkable monomer is preferable in that the operation is simple and the degree of crosslinking can be easily controlled.
  • Crosslinkable monomer a polyfunctional polymerizable monomer having two or more polymerizable unsaturated groups, a monomer having a crosslinkable functional group capable of self-crosslinking such as a hydrolyzable silyl group, etc. It can be mentioned.
  • the above-mentioned polyfunctional polymerizable monomer is a compound having two or more polymerizable functional groups such as (meth) acryloyl group and alkenyl group in the molecule, and a polyfunctional (meth) acrylate compound, a polyfunctional alkenyl compound, Examples thereof include compounds having both an acryloyl group and an alkenyl group.
  • polyfunctional alkenyl compounds are preferable in that a uniform crosslinked structure can be easily obtained, and polyfunctional allyl ether compounds having a plurality of allyl ether groups in the molecule are particularly preferable.
  • polyfunctional (meth) acrylate compounds include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol Di) (meth) acrylates of dihydric alcohols such as meta) acrylate; trimethylolpropane tri (meth) acrylate, tri (meth) acrylate of trimethylol propane ethylene oxide modified product, glycerin tri (meth) acrylate, pentaerythritol tri ( Poly (meth) acrylates such as tri (meth) acrylates and tetra (meth) acrylates of trivalent or higher polyhydric alcohols such as meth) acrylates and pentaerythritol tetra (meth) acrylates Relate; methylenebisacrylamide, it can be mentioned bisamides such as hydroxyethylene bis(
  • polyfunctional alkenyl compounds polyfunctional allyl ether compounds such as trimethylolpropane diallyl ether, trimethylolpropane triallyl ether, pentaerythritol diallyl ether, pentaerythritol triallyl ether, tetraallyloxyethane, polyallyl saccharose; diallyl phthalate and the like
  • polyfunctional vinyl compounds such as divinylbenzene.
  • Examples of compounds having both (meth) acryloyl group and alkenyl group include allyl (meth) acrylate, isopropenyl (meth) acrylate, butenyl (meth) acrylate, pentenyl (meth) acrylate, (meth) acrylic acid 2- (2-vinyloxyethoxy) ethyl and the like can be mentioned.
  • the monomer having a crosslinkable functional group that is self-crosslinkable include hydrolyzable silyl group-containing vinyl monomers, N-methylol (meth) acrylamide, N-methoxyalkyl (meth) acrylate, etc. Can be mentioned. These compounds can be used singly or in combination of two or more.
  • the hydrolyzable silyl group-containing vinyl monomer is not particularly limited as long as it is a vinyl monomer having at least one hydrolyzable silyl group.
  • vinylsilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, etc .
  • silyl such as trimethoxysilylpropyl acrylate, triethoxysilylpropyl acrylate, methyldimethoxysilylpropyl acrylate and the like
  • Silyl group-containing methacrylic acid esters such as trimethoxysilylpropyl methacrylate, triethoxysilylpropyl methacrylate, methyldimethoxysilylpropyl methacrylate, dimethylmethoxysilyl propyl methacrylate; trimethoxysilylpropyl vinyl ether etc.
  • silyl group-containing vinyl esters such as vinyl
  • the amount of the crosslinking monomer used is the total amount of monomers (non-crosslinking monomers) other than the crosslinking monomer.
  • the amount is preferably 0.02 to 0.7 mol%, more preferably 0.03 to 0.4 mol%. If the amount of use of the crosslinkable monomer is 0.02 mol% or more, it is preferable in that the binding property and the stability of the mixture layer slurry become better. If it is 0.7 mol% or less, the stability of the crosslinked polymer tends to be high.
  • the particle size of the crosslinked polymer is not particularly limited. However, in the mixture layer composition, water having an appropriate particle size without the crosslinked polymer being present as a large particle size block (secondary aggregate) When it is well dispersed as swollen particles, a binder containing the crosslinked polymer is preferable because it can exhibit good binding performance.
  • the particle size of the crosslinked polymer of the present invention or the salt thereof when dispersed in water having a degree of neutralization of 80 to 100 mol% based on the carboxyl group of the crosslinked polymer water swelled particle size Is preferably in the range of 0.1 ⁇ m or more and 10 ⁇ m or less in terms of volume-based median diameter.
  • a more preferable range of the particle diameter is 0.2 ⁇ m or more and 5.0 ⁇ m or less, and a further preferable range is 0.5 ⁇ m or more and 3.0 ⁇ m or less.
  • the particle size is in the range of 0.1 ⁇ m or more and 10 ⁇ m or less, the particle size is uniform and suitable in the mixture layer composition, so the stability of the mixture layer composition is high and the binding property is excellent. It is possible to demonstrate If the particle size is 10 ⁇ m or less, sufficient binding properties can be exhibited. If the particle size is 0.1 ⁇ m or more, a crosslinked polymer can be stably produced. In addition, the said water swelling particle diameter can be measured by the method as described in an Example of this specification.
  • the cross-linked polymer is unneutralized or less than 80 mol% neutralization degree, neutralize to 80 to 100 mol% neutralization degree with alkali metal hydroxide etc. and measure the particle size when dispersed in water do it.
  • the crosslinked polymer or a salt thereof often exists as a lumped particle in which primary particles are associated and aggregated.
  • the particle size in the above water dispersion is in the above range, the cross-linked polymer or the salt thereof has extremely excellent dispersibility, and it is neutralized to a neutralization degree of 80 to 100 mol% to be water.
  • dispersing lumped particles are loosened, and even if it is a dispersion of primary particles or a secondary aggregate, a stable dispersion state is formed with the particle diameter in the range of 0.1 to 10 ⁇ m. is there.
  • the particle size distribution which is a value obtained by dividing the volume average median size of the water-swelled particle size by the number average median size, is preferably 10 or less, more preferably 3.0 or less, further preferably from the viewpoint of binding properties. Is 1.5 or less.
  • the lower limit of the particle size distribution is usually 1.0.
  • the particle size (dry particle size) of the crosslinked polymer of the present invention or a salt thereof at the time of drying is preferably in the range of 0.03 ⁇ m or more and 3 ⁇ m or less on a volume basis median diameter.
  • a more preferable range of the particle diameter is 0.1 ⁇ m or more and 1 ⁇ m or less, and a further preferable range is 0.3 ⁇ m or more and 0.8 ⁇ m or less.
  • the said dry particle diameter can be measured by the method as described in this-application Example.
  • the toughness increases, and it becomes possible to obtain high bondability, and the viscosity of the aqueous dispersion increases.
  • a crosslinked polymer (salt) obtained by applying a relatively small amount of crosslinking to a polymer having a long primary chain length exists in water as a water-swollen microgel body.
  • the thickening effect and the dispersion stabilizing effect are exhibited by the interaction of the microgel body.
  • the interaction of the microgel body changes depending on the degree of water swelling of the microgel body and the strength of the microgel body, but these are influenced by the degree of crosslinking of the crosslinked polymer.
  • the degree of crosslinking is too low, the strength of the microgel may be insufficient, and the dispersion stabilization effect and the binding property may be insufficient.
  • the degree of crosslinking is too high, the degree of swelling of the microgel may be insufficient, and the dispersion stabilizing effect and the binding property may be insufficient. That is, it is desirable that the crosslinked polymer be a finely crosslinked polymer obtained by appropriately crosslinking the polymer having a sufficiently long primary chain length.
  • acid groups such as carboxyl groups derived from ethylenically unsaturated carboxylic acid monomers are neutralized so that the degree of neutralization in the mixture layer composition is 20 to 100 mol%. And is preferably used as a salt embodiment.
  • the degree of neutralization is more preferably 50 to 100 mol%, and still more preferably 60 to 95 mol%. When the degree of neutralization is 20 mol% or more, it is preferable in that the water swellability is good and the dispersion stabilizing effect is easily obtained.
  • the above-mentioned degree of neutralization can be calculated by calculation from charged values of a monomer having an acid group such as a carboxyl group and a neutralizing agent used for neutralization.
  • the cross-linked polymer may be a known polymerization method such as solution polymerization, precipitation polymerization, suspension polymerization or emulsion polymerization, but precipitation polymerization and suspension polymerization (reverse phase suspension polymerization) in terms of productivity Is preferred.
  • Heterogeneous polymerization methods such as precipitation polymerization, suspension polymerization, and emulsion polymerization are preferable, and precipitation polymerization is more preferable, from the viewpoint of obtaining better performance with regard to binding properties and the like.
  • Precipitation polymerization is a method of producing a polymer by carrying out a polymerization reaction in a solvent which dissolves the raw material unsaturated monomer but does not substantially dissolve the produced polymer.
  • the polymer particles become larger due to aggregation and growth, and a dispersion liquid of polymer particles in which primary particles of several tens of nm to several hundreds of nm are secondarily aggregated to several ⁇ m to several tens of ⁇ m is obtained.
  • Dispersion stabilizers can also be used to control the particle size of the polymer.
  • the above secondary aggregation can also be suppressed by selecting a dispersion stabilizer, a polymerization solvent and the like. In general, precipitation polymerization in which secondary aggregation is suppressed is also called dispersion polymerization.
  • the polymerization solvent a solvent selected from water, various organic solvents and the like can be used in consideration of the kind of the monomer to be used and the like. In order to obtain a polymer having a longer primary chain length, it is preferable to use a solvent having a small chain transfer constant.
  • Specific polymerization solvents include water-soluble solvents such as methanol, t-butyl alcohol, acetone, methyl ethyl ketone, acetonitrile and tetrahydrofuran, as well as benzene, ethyl acetate, dichloroethane, n-hexane, cyclohexane and n-heptane. These 1 type can be used individually or in combination of 2 or more types. Or you may use as a mixed solvent of these and water.
  • the water-soluble solvent means one having a solubility in water at 20 ° C. of more than 10 g / 100 ml.
  • a highly polar solvent preferably include water and methanol.
  • the amount of the highly polar solvent used is preferably 0.05 to 10.0% by mass, more preferably 0.1 to 5.0% by mass, and still more preferably 0.1 to 1 based on the total mass of the medium. It is .0 mass%. If the proportion of the high polar solvent is 0.05% by mass or more, the effect on the above-mentioned neutralization reaction is observed, and if it is 10.0% by mass or less, no adverse effect on the polymerization reaction is observed.
  • a highly hydrophilic ethylenic unsaturated carboxylic acid monomer such as acrylic acid
  • a highly polar solvent when added, the polymerization rate is improved, and a polymer having a long primary chain length can be easily obtained.
  • water is particularly preferable because the effect of improving the polymerization rate is large.
  • a crosslinked polymer is obtained by polymerizing a monomer component containing an ethylenically unsaturated carboxylic acid monomer in the presence of an organic amine compound.
  • the binder containing the crosslinked polymer or the salt thereof thus obtained can exhibit high binding properties.
  • the monomer component containing the ethylenically unsaturated carboxylic acid monomer is polymerized in the presence of the organic amine compound, the polymerization stability is improved, and the crosslinking weight is increased even at a high monomer concentration.
  • the uniting can be produced stably.
  • the monomer concentration may be, for example, about 10.0% by mass or more, but is preferably 13.0% by mass or more from the viewpoint of binding properties.
  • the monomer concentration is more preferably 15.0% by mass or more, still more preferably 17.0% by mass or more, and still more preferably 19.0% by mass or more.
  • the monomer concentration is more preferably 20.0% by mass or more, still more preferably 22.0% by mass or more, and still more preferably 25.0% by mass or more.
  • the higher the monomer concentration at the time of polymerization the higher the molecular weight can be obtained, and a polymer having a long primary chain length can be produced. Since the crosslinked polymer of the present invention is a finely crosslinked polymer obtained by appropriately crosslinking the polymer having a sufficiently long primary chain length, direct measurement of the primary chain length is analytically difficult. .
  • the primary chain length of a polymer is known to be correlated with the solution viscosity, but in the case of a crosslinked polymer, the solution viscosity also varies depending on the degree of crosslinking. Therefore, it is very difficult to define the crosslinked polymer obtained by the above method by the structure or characteristics of the polymer.
  • “monomer concentration” refers to the monomer concentration in the reaction liquid at the time of initiating polymerization.
  • the upper limit of the monomer concentration varies depending on the types of monomers and solvents used, and the polymerization method and various polymerization conditions, but if heat removal from the polymerization reaction is possible, it is approximately 40% in precipitation polymerization.
  • the degree is about 50% in suspension polymerization and about 70% in emulsion polymerization.
  • the polymerization reaction by performing the polymerization reaction in the presence of the organic amine compound, it is possible to obtain a crosslinked polymer having excellent binding properties. Furthermore, the polymerization reaction can be stably carried out even under high monomer concentration conditions, for example, exceeding 13.0% by mass. A polymer obtained by polymerization at such a high monomer concentration is excellent in binding ability because of its high molecular weight (because of the long primary chain length).
  • organic amine compound other than ammonia, for example, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monobutylamine, dibutylamine, tributylamine, monohexylamine, dihexylamine, trihexylamine, trioctylamine And N-alkyl substituted amines such as tridodecylamine; (alkyl) alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, propanolamine, dimethylethanolamine and N, N-dimethylethanolamine; pyridine, piperidine, piperazine, Cyclic amines such as 1,8-bis (dimethylamino) naphthalene, morpholine and diazabicycloundecene (DBU); diethylene tri Min, N, N-dimethylbenzylamine, and the like, may be used alone or two or more of these.
  • DBU di
  • organic amine compounds other than ammonia are preferable from the viewpoint of binding ability.
  • a hydrophobic amine having a long chain alkyl group when used, larger electrostatic repulsion and steric repulsion can be obtained, so that the polymerization stability can be easily secured even when the monomer concentration is high.
  • the higher the value (C / N) represented by the ratio of the number of carbon atoms to the number of nitrogen atoms present in the organic amine compound the higher the polymerization stabilization effect by the steric repulsion effect.
  • the value of C / N is preferably 3 or more, more preferably 5 or more, further preferably 10 or more, and still more preferably 20 or more.
  • An amine compound having a high C / N value is generally a compound having a high hydrophobicity and a low amine value.
  • an amine compound having a high C / N value tends to exhibit a high polymerization stabilization effect, and it becomes possible to increase the monomer concentration at the time of polymerization, so that the polymer has a high molecular weight (primary chain And the integrity tends to be improved.
  • a crosslinked polymer having a small particle size or a salt thereof tends to be obtained. Therefore, the adhesion to the active material and the like is increased, and the binding property is improved.
  • a polymerization step of polymerizing a monomer component containing an ethylenically unsaturated carboxylic acid monomer For example, 10% by mass or more and 100% by mass or less of the ethylenically unsaturated carboxylic acid monomer from which the component (a) is derived, and 0 mass of another ethylenically unsaturated monomer from which the component (b) is derived It is preferable to have a polymerization step of polymerizing a monomer component containing% or more and 90% by mass or less.
  • the structural unit (component (a)) derived from the ethylenically unsaturated carboxylic acid monomer is introduced into the crosslinked polymer in an amount of 10% by mass or more and 100% by mass or less through the polymerization step.
  • the use amount of the ethylenically unsaturated carboxylic acid monomer is also, for example, 20% by mass or more and 100% by mass or less, and for example, 30% by mass or more and 100% by mass or less, for example, 50% by mass Above, it is 99 mass% or less.
  • the polymerization step is preferably performed by a precipitation polymerization method in that a polymer particle having a small particle size excellent in uniformity is easily obtained.
  • an organic amine compound of 0.001 mol% or more with respect to the above-mentioned ethylenically unsaturated carboxylic acid monomer.
  • the amount of the organic amine compound used relative to the ethylenically unsaturated carboxylic acid monomer is preferably 0.01 mol% or more, more preferably 0.03 mol% or more, and still more preferably 0.05 mol% or more It is.
  • the amount of the organic amine compound used may be 0.3 mol% or more, or 0.5 mol% or more. Moreover, it is preferable that the upper limit of the usage-amount of an organic amine compound is 4.0 mol% or less.
  • the amount of the organic amine compound used relative to the ethylenically unsaturated carboxylic acid monomer is preferably 3.0 mol% or less, more preferably 2.0 mol% or less, and still more preferably 1.0 mol% or less It is.
  • the amount of the organic amine compound used represents the molar concentration of the organic amine compound used relative to the ethylenically unsaturated carboxylic acid monomer, and means the degree of neutralization. Absent. That is, the valence of the organic amine compound used is not considered.
  • another ethylenically unsaturated monomer copolymerizable therewith may be contained as a monomer component.
  • the other ethylenically unsaturated monomer for example, an ethylenically unsaturated monomer compound having an anionic group other than a carboxyl group such as a sulfonic acid group and a phosphoric acid group, and a nonionic ethylenic character Unsaturated monomer etc. are mentioned.
  • transduce the component (b) mentioned above is mentioned.
  • the other ethylenically unsaturated monomer may be contained in an amount of 0% by mass or more and 90% by mass or less, or 1% by mass or more and 60% by mass or less based on the total amount of the monomer components.
  • the content may be 50% by mass or more, and 10% by mass or more and 30% by mass or less.
  • you may use the said crosslinkable monomer similarly.
  • polymerization initiator known polymerization initiators such as azo compounds, organic peroxides and inorganic peroxides can be used, but are not particularly limited.
  • the conditions of use can be adjusted by a known method such as heat initiation, redox initiation in combination with a reducing agent, UV initiation, etc., to obtain an appropriate radical generation amount.
  • heat initiation heat initiation
  • redox initiation in combination with a reducing agent
  • UV initiation etc.
  • organic peroxide examples include 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane (manufactured by NOF Corporation, trade name "Pertetra A”), 1,1-di (t- Hexylperoxy) cyclohexane (also “perhexa HC"), 1,1-di (t-butylperoxy) cyclohexane (also “perhexa C”), n-butyl-4,4-di (t-butylperoxy) Barrelate (the same "perhexa V"), 2, 2- di (t- butylperoxy) butane (the same "perhexa 22"), t- butyl hydroperoxide (the same "perbutyl H”), cumene hydroperoxide (the day Oil Co., Ltd., trade name "Percumyl H”), 1,1,3,3-Tetramethylbutyl hydroperoxide (the same "Perocta H”),
  • inorganic peroxide examples include potassium persulfate, sodium persulfate and ammonium persulfate.
  • potassium persulfate sodium persulfate
  • sodium persulfate sodium persulfate
  • ammonium persulfate sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, sulfur dioxide gas (SO 2 ), ferrous sulfate and the like can be used as a reducing agent.
  • the preferred amount of use of the polymerization initiator is, for example, 0.001 to 2 parts by mass, for example, 0.005 to 1 parts by mass, based on 100 parts by mass of the total amount of the monomer components to be used. For example, it is 0.01 to 0.1 parts by mass. If the amount of the polymerization initiator used is 0.001 parts by mass or more, the polymerization reaction can be stably carried out, and if it is 2 parts by mass or less, a polymer having a long primary chain length can be easily obtained.
  • the concentration of the monomer component at the time of polymerization is preferably high from the viewpoint of obtaining a polymer having a longer primary chain length.
  • the concentration of the monomer component is too high, aggregation of the polymer particles is likely to proceed, and control of the heat of polymerization is difficult, which may cause runaway of the polymerization reaction. Therefore, for example, in the case of precipitation polymerization, the monomer concentration at the start of polymerization is generally in the range of about 2 to 40% by mass, preferably in the range of 5 to 40% by mass.
  • the crosslinked polymer of the present invention is preferably obtained by polymerization at a monomer concentration of 13.0% by mass or more at the start of polymerization.
  • the monomer concentration is more preferably 15.0% by mass or more, further preferably 17.0% by mass or more, still more preferably 19.0% by mass or more, still more preferably 20.0% by mass It is above.
  • the monomer concentration is more preferably 22.0% by mass or more, and most preferably 25.0% by mass or more.
  • the polymerization temperature is preferably 0 to 100 ° C., and more preferably 20 to 80 ° C., although it depends on conditions such as the type and concentration of monomers to be used.
  • the polymerization temperature may be constant or may change during the polymerization reaction.
  • the polymerization time is preferably 1 minute to 20 hours, more preferably 1 hour to 10 hours.
  • the crosslinked polymer dispersion obtained through the polymerization step can be subjected to pressure reduction and / or heat treatment or the like in the drying step to distill off the solvent, whereby the target crosslinked polymer can be obtained in the form of powder.
  • solid-liquid separation processes such as centrifugation and filtration, following a polymerization process for the purpose of removing unreacted monomer (and its salt), impurities derived from an initiator, etc. before the above-mentioned drying process. It is preferable to have a washing step using the same solvent as methanol, or the polymerization solvent.
  • the residual solvent and unreacted monomer contained in the crosslinked polymer powder are preferably as small as possible from the viewpoint of odor, battery performance and safety (cell swelling due to gasification, etc.). Specifically, it is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, still more preferably 0.5% by mass or less, more preferably 0% by mass in the crosslinked polymer powder. .1% by mass or less.
  • a polymerization reaction of a monomer composition containing an ethylenically unsaturated carboxylic acid monomer is carried out in the presence of a base compound, but an alkali compound is added to the polymer dispersion obtained by the polymerization step.
  • the solvent may be removed in the drying step.
  • an alkali compound is added when preparing the electrode mixture layer slurry to neutralize the polymer (hereinafter referred to as “after It may be called “sum”.
  • the process neutralization is preferable because secondary aggregates tend to be easily entangled.
  • the crosslinked polymer may be provided with a metal removal step of removing metal foreign matter in the state of the slurry after the polymerization step or in the state of the powder after the drying step.
  • a metal removal step of removing metal foreign matter in the state of the slurry after the polymerization step or in the state of the powder after the drying step.
  • known methods such as a lattice type magnet, a magnet strainer, a magnet filter, an electromagnetic separator, a magnet pulley, a drum magnetic separator and a suspension magnetic separator can be used.
  • the metal removing step magnetic foreign matter having a size of several tens to several hundreds of ⁇ m or more is removed.
  • the amount of foreign metal contained in the crosslinked polymer after the step of removing foreign metal is preferably 10 ppm or less, more preferably 1 ppm or less, still more preferably 0.1 ppm or less, relative to the crosslinked polymer. Is less than 0.01 ppm.
  • the composition for a non-aqueous electrolyte secondary battery electrode mixture layer of the present invention comprises a binder containing the above-described crosslinked polymer or a salt thereof, an active material, and water.
  • the use amount of the crosslinked polymer or the salt thereof in the electrode mixture layer composition of the present invention is, for example, 0.1% by mass or more and 20% by mass or less with respect to the total amount of the active material.
  • the use amount is also, for example, 0.2% by mass or more and 10% by mass or less, for example, 0.3% by mass or more and 8% by mass or less, for example, 0.4% by mass or more and 5% by mass or less .
  • the amount of use of the crosslinked polymer and the salt thereof is less than 0.1% by mass, sufficient binding properties may not be obtained. In addition, the dispersion stability of the active material and the like may be insufficient, and the uniformity of the formed mixture layer may be reduced. On the other hand, when the use amount of the crosslinked polymer and the salt thereof exceeds 20% by mass, the electrode mixture layer composition may have a high viscosity, and the coatability to the current collector may be reduced. As a result, bumps and irregularities may be generated in the obtained mixture layer, which may adversely affect the electrode characteristics.
  • the amount of the crosslinked polymer and the salt thereof used is in the above range, a composition having excellent dispersion stability can be obtained, and a mixture layer having extremely high adhesion to the current collector can be obtained, and the result is As the battery durability improves. Furthermore, the crosslinked polymer and the salt thereof exhibit sufficiently high binding ability even in a small amount (for example, 5% by mass or less) with respect to the active material, and have a carboxy anion, so the interface resistance is small and high rate characteristics are obtained. An excellent electrode is obtained.
  • lithium salts of transition metal oxides are mainly used as the positive electrode active material, and for example, layered rock salt type and spinel type lithium containing metal oxides can be used.
  • Specific compounds of the positive electrode active material of layered rock-salt, lithium cobaltate, lithium nickelate, and, NCM ⁇ Li (Ni x, Co y, Mn z), x + y + z 1 ⁇ called ternary and NCA ⁇ Li (Ni 1-ab Co a Al b) ⁇ , and the like.
  • lithium manganate etc. are mentioned as a spinel type positive electrode active material.
  • phosphates examples include olivine-type lithium iron phosphate and the like.
  • the positive electrode active material one of the above may be used alone, or two or more may be used in combination as a mixture or a composite.
  • the amount of unneutralized or partially neutralized crosslinked polymer used should be such that the amount of non-neutralized carboxyl groups of the crosslinked polymer is equivalent to or more than the amount of alkali eluted from the active material. Is preferred.
  • the conductive aid include carbon-based materials such as carbon black, carbon nanotubes, carbon fibers, graphite fine powder, carbon fibers, etc. Among them, carbon black, carbon nanotubes and carbon fibers from the viewpoint of easily obtaining excellent conductivity. Is preferred. Moreover, as carbon black, ketjen black and acetylene black are preferable.
  • the conductive aids may be used alone or in combination of two or more. The amount of the conductive aid can be, for example, 0.2 to 20% by mass with respect to the total amount of the active material from the viewpoint of achieving both conductivity and energy density, and for example, 0.2 to 10%. It can be mass%.
  • the positive electrode active material may be surface-coated with a conductive carbon-based material.
  • examples of the negative electrode active material include carbon-based materials, lithium metals, lithium alloys, metal oxides and the like, and one or more of these can be used in combination.
  • active materials composed of carbon-based materials such as natural graphite, artificial graphite, hard carbon and soft carbon (hereinafter also referred to as “carbon-based active materials”) are preferred, and graphite such as natural graphite and artificial graphite Hard carbon is more preferred.
  • graphite spheroidized graphite is preferably used from the viewpoint of battery performance, and the preferable range of the particle size thereof is, for example, 1 to 20 ⁇ m, and for example, 5 to 15 ⁇ m.
  • a metal or metal oxide or the like capable of storing lithium such as silicon or tin can also be used as the negative electrode active material.
  • silicon has a higher capacity than graphite, and active materials composed of silicon materials such as silicon, silicon alloys and silicon oxides such as silicon monoxide (SiO) (hereinafter also referred to as “silicon-based active materials”) Can be used.
  • silicon-based active material has a high capacity, but on the other hand, there is a large volume change due to charge and discharge. For this reason, it is preferable to use together with the said carbon-type active material.
  • the compounding amount of the silicon-based active material is large, the electrode material may be broken, and the cycle characteristics (durability) may be significantly reduced.
  • the amount used is, for example, 60% by mass or less, and for example, 30% by mass or less with respect to the carbon-based active material.
  • the binder containing the crosslinked polymer of the present invention has a structural unit (component (a)) derived from the ethylenically unsaturated carboxylic acid monomer.
  • component (a) has a high affinity to the silicon-based active material and exhibits a good binding property. Therefore, since the binder of the present invention exhibits excellent binding even when using a high capacity type active material containing a silicon-based active material, it is also effective for improving the durability of the obtained electrode. It is considered to be a thing.
  • the carbon-based active material itself has good electrical conductivity, it is not always necessary to add a conductive aid.
  • a conductive auxiliary is added for the purpose of further reducing resistance, the amount used is, for example, 10% by mass or less, for example, 5% by mass or less, based on the total amount of active materials from the viewpoint of energy density. It is.
  • the amount of the active material used is, for example, in the range of 10 to 75% by mass with respect to the total amount of the composition. It is in the range of 65% by mass.
  • the amount of the active material used is 10% by mass or more, the migration of the binder and the like can be suppressed, and it is also advantageous in terms of the drying cost of the medium.
  • it is 75 mass% or less, the fluidity and the coatability of the composition can be secured, and a uniform mixture layer can be formed.
  • the amount of active material used is, for example, in the range of 60 to 97% by mass with respect to the total amount of the composition, and for example, 70 to 90 It is the range of mass%.
  • non-volatile components other than active materials such as binders and conductive assistants should be as small as possible within the range in which necessary binding properties and conductivity are ensured.
  • the composition for a non-aqueous electrolyte secondary battery electrode mixture layer uses water as a medium. Further, for the purpose of adjusting the properties and drying properties of the composition, lower alcohols such as methanol and ethanol, carbonates such as ethylene carbonate, ketones such as acetone, water soluble organic solvents such as tetrahydrofuran, N-methylpyrrolidone and the like It may be a mixed solvent with The proportion of water in the mixed medium is, for example, 50% by mass or more, and for example, 70% by mass or more.
  • the content of the medium containing water occupied in the whole composition is the coating property of the slurry, the energy cost required for drying, the viewpoint of productivity
  • the viewpoint of productivity For example, it can be in the range of 25 to 90% by mass, and can be, for example, 35 to 70% by mass.
  • the content of the above-mentioned medium can be, for example, in the range of 3 to 40% by mass from the viewpoint of the uniformity of the mixture layer after pressing. It can be in the range of ⁇ 30% by mass.
  • the binder of the present invention may consist only of the above-mentioned crosslinked polymer or a salt thereof, but other than this, it is possible to use other materials such as styrene / butadiene latex (SBR), acrylic latex and polyvinylidene fluoride latex. You may use a binder component together.
  • SBR styrene / butadiene latex
  • the amount used can be, for example, 0.1 to 5% by mass or less, and for example, 0.1 to 2% by mass or less, with respect to the active material. And, for example, 0.1 to 1% by mass or less. If the amount of the other binder component used exceeds 5% by mass, the resistance may increase and the high rate characteristics may be insufficient.
  • the styrene / butadiene latex is preferable in that it is excellent in the balance between the binding property and the bending resistance.
  • the styrene / butadiene latex is a copolymer having a structural unit derived from an aromatic vinyl monomer such as styrene and a structural unit derived from an aliphatic conjugated diene monomer such as 1,3-butadiene. 1 shows an aqueous dispersion.
  • aromatic vinyl monomer in addition to styrene, ⁇ -methylstyrene, vinyltoluene, divinylbenzene and the like can be mentioned, and one or more of these can be used.
  • the structural unit derived from the above-mentioned aromatic vinyl monomer in the above-mentioned copolymer can be, for example, in the range of 20 to 60% by mass, mainly from the viewpoint of binding property, and also, for example, 30 to 50 It can be in the range of mass%.
  • aliphatic conjugated diene type monomer in addition to 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene Butadiene etc. are mentioned and 1 type, or 2 or more types in these can be used.
  • the structural unit derived from the aliphatic conjugated diene monomer in the copolymer is, for example, 30 to 70% by mass in that the binding property of the binder and the flexibility of the obtained electrode are good. And, for example, in the range of 40 to 60% by mass.
  • styrene / butadiene-based latex may contain a nitrile group-containing monomer such as (meth) acrylonitrile as the other monomer in order to further improve the performance such as binding property.
  • a carboxyl group-containing monomer such as acrylic acid, itaconic acid or maleic acid may be used as a copolymer monomer.
  • the structural unit derived from the other monomer in the copolymer can be, for example, in the range of 0 to 30% by mass, and can also be in the range of 0 to 20% by mass, for example.
  • the composition for a non-aqueous electrolyte secondary battery electrode mixture layer of the present invention contains the above-mentioned active material, water and a binder as essential components, and is prepared by mixing the components using a known means. can get.
  • the mixing method of each component is not particularly limited, and a known method can be adopted, but after dry blending of powder components such as active material, conductive additive and crosslinked polymer particles as binder, water is used.
  • the method of mixing with a dispersion medium such as, etc., and dispersing and kneading is preferable.
  • a mixing means known mixers such as a planetary mixer, a thin film swirl mixer and a self-revolving mixer can be used, but a thin film swirl mixer is used in that a good dispersion state can be obtained in a short time. Is preferred.
  • a thin film revolving mixer it is preferable to perform preliminary dispersion beforehand with a stirrer such as a disper.
  • the viscosity of the above-mentioned slurry can be, for example, in the range of 500 to 100,000 mPa ⁇ s as B-type viscosity at 60 rpm, and for example, in the range of 1,000 to 50,000 mPa ⁇ s. it can.
  • composition for the electrode mixture layer when obtained in a wet powder state, it is preferable to knead it to a uniform state without concentration unevenness using a Henschel mixer, a blender, a planetary mixer, a twin-screw kneader or the like.
  • the concentration of polyvalent metal ions in the composition for a non-aqueous electrolyte secondary battery electrode mixture layer is preferably 100 ppm or less, more preferably 50 ppm or less, more preferably 50 ppm or less, based on the crosslinked polymer. It is 10 ppm or less.
  • the polyvalent metal is not particularly limited, and examples thereof include Fe, Al, Cr, Cu, Ca and the like.
  • the electrode for a non-aqueous electrolyte secondary battery of the present invention comprises a mixture layer formed of the composition for an electrode mixture layer on the surface of a current collector such as copper or aluminum.
  • the mixture layer is formed by applying the composition for electrode mixture layer of the present invention to the surface of the current collector and then drying and removing a medium such as water.
  • the method for applying the mixture layer composition is not particularly limited, and a known method such as a doctor blade method, a dip method, a roll coating method, a comma coating method, a curtain coating method, a gravure coating method or an extrusion method is employed. be able to.
  • the said drying can be performed by well-known methods, such as a warm air blowing, pressure reduction, (far) infrared rays, and microwave irradiation.
  • the mixture layer obtained after drying is subjected to a compression treatment by a die press, a roll press or the like.
  • a compression treatment by a die press, a roll press or the like.
  • the thickness of the mixture layer can be adjusted to, for example, about 30 to 80% before compression by compression, and the thickness of the mixture layer after compression is generally about 4 to 200 ⁇ m.
  • a non-aqueous electrolyte secondary battery can be produced by providing the electrode for a non-aqueous electrolyte secondary battery of the present invention with a separator and a non-aqueous electrolyte.
  • the separator is disposed between the positive electrode and the negative electrode of the battery, and plays a role of preventing short circuit due to the contact of both electrodes and maintaining the electrolytic solution to secure the ion conductivity.
  • the separator is preferably a film-like insulating microporous membrane having good ion permeability and mechanical strength.
  • polyolefins such as polyethylene and polypropylene, polytetrafluoroethylene and the like can be used.
  • the non-aqueous electrolyte can be a known one commonly used in non-aqueous electrolyte secondary batteries.
  • the solvent include cyclic carbonates having a high dielectric constant such as propylene carbonate and ethylene carbonate and having a high ability to dissolve the electrolyte, and low viscosity linear carbonates such as ethyl methyl carbonate, dimethyl carbonate and diethyl carbonate. These can be used alone or as a mixed solvent.
  • the non-aqueous electrolytic solution is used by dissolving a lithium salt such as LiPF 6 , LiSbF 6 , LiBF 4 , LiClO 4 , LiAlO 4 or the like in these solvents.
  • a non-aqueous electrolyte secondary battery is obtained by accommodating the positive electrode plate and the negative electrode plate separated by the separator in a spiral or laminated structure in a case or the like.
  • the binder for a non-aqueous electrolyte secondary battery electrode disclosed in the present specification exhibits excellent binding property with the electrode material and excellent adhesion property with the current collector in the mixture layer. For this reason, the non-aqueous electrolyte secondary battery provided with the electrode obtained by using the above-mentioned binder can ensure good integrity, and is expected to exhibit good durability (cycle characteristics) even if charge and discharge are repeated. And suitable for use in on-vehicle secondary batteries and the like.
  • the inside of the reactor was sufficiently purged with nitrogen, and then warmed to raise the internal temperature to 55 ° C. After confirming that the internal temperature was stabilized at 55 ° C., 2, 2′-azobis (2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, trade name “V-65”) 0 as a polymerization initiator When 040 parts were added, white turbidity was observed in the reaction solution, and this point was regarded as the polymerization initiation point. The monomer concentration was calculated to be 15.0%. The polymerization reaction was continued while maintaining the internal temperature at 55 ° C. by adjusting the external temperature (water bath temperature), and the internal temperature was raised to 65 ° C. after 6 hours from the polymerization initiation point.
  • V-65 2, 2′-azobis (2,4-dimethylvaleronitrile)
  • the internal temperature is maintained at 65 ° C., and cooling of the reaction solution is started 12 hours after the reaction start point, and after the internal temperature drops to 25 ° C. lithium hydroxide monohydrate (hereinafter referred to as “LiOH” • 52.5 parts of powder of H 2 O ”) were added. After the addition, stirring was continued at room temperature for 12 hours to obtain a slurry-like polymerization reaction solution in which particles of a crosslinked polymer salt R-1 (Li salt, neutralization degree 90 mol%) were dispersed in a medium.
  • LiOH lithium hydroxide monohydrate
  • the particle size of the polymerization reaction solution containing the crosslinked polymer salt R-1 obtained above is measured using a laser diffraction / scattering type particle size distribution analyzer (Microtrac MT-3300EXII manufactured by Microtrac Bell Co., Ltd.) using acetonitrile as a dispersion medium. It measured. The volume based median diameter was 0.35 ⁇ m.
  • the resulting polymerization reaction solution was centrifuged to precipitate polymer particles, and then the supernatant was removed. Thereafter, the precipitate was re-dispersed in acetonitrile having the same weight as that of the polymerization reaction solution, and then the washing operation of settling polymer particles by centrifugation and removing the supernatant was repeated twice.
  • the precipitate was collected, dried at 80 ° C. for 3 hours under reduced pressure conditions, and volatile components were removed to obtain a powder of a crosslinked polymer salt R-1. Since the crosslinked polymer salt R-1 has hygroscopicity, it was sealed and stored in a container having water vapor barrier properties.
  • Evaluation criteria :: volume-based median diameter / number-based median diameter less than 1.5 ⁇ : volume-based median diameter / number-based median diameter 1.5 or more and less than 3.0 ⁇ : volume-based median diameter / number-based median diameter 3 .0 or more and less than 10 ⁇ : Volume based median diameter / number based median diameter is 10 or more
  • AA acrylic acid
  • IBXA isobornyl acrylate
  • DMAA N, N-dimethyl acrylamide
  • P-30 pentaerythritol triallyl ether (manufactured by Daiso, trade name "Neoallyl P-30")
  • T-20 trimethylolpropane diallyl ether (made by Daiso, trade name "Neoallyl T-20")
  • TMA trimethylamine (C / N value: 3)
  • TEA Triethylamine (C / N value: 6)
  • TOA Trioctylamine (C / N value: 24)
  • TDA tridodecylamine (C / N value: 36)
  • TSA tristearylamine (C / N value: 54)
  • Pyridine (C / N value: 5) Dibutylamine: (C / N value: 8) Hexylamine: (C / N value: 6)
  • DMAN 1,
  • Example 1 3.2 parts of powdery crosslinked polymer Li salt R-1 is weighed into 100 parts of natural graphite, mixed well in advance, 160 parts of ion exchanged water is added, predispersion is carried out with a disper, and thin film swirling type This dispersion was carried out for 15 seconds using a mixer (manufactured by Primix, FM-56-30) at a peripheral speed of 20 m / sec to obtain a slurry-like composition for a negative electrode mixture layer. The composition for the mixture layer is applied on a 20 ⁇ m thick copper foil (manufactured by Japan Foil Co., Ltd.) using a variable applicator, and the mixture is dried in a ventilation dryer at 100 ° C. for 15 minutes. A layer was formed. Thereafter, the mixture layer was rolled so as to have a thickness of 50 ⁇ 5 ⁇ m and a packing density of 1.70 ⁇ 0.20 g / cm 3 .
  • the negative electrode obtained above was cut into a strip of 25 mm width, and then the mixture layer surface of the above sample was attached to a double-sided tape fixed on a horizontal surface to prepare a sample for peeling test. After the test sample was dried at 60 ° C. under reduced pressure conditions overnight, 90 ° peeling was performed at a tensile speed of 50 mm / min, and the peel strength between the mixture layer and the copper foil was measured. The peel strength was as high as 15.2 N / m and good.
  • Examples 2 to 22 and Comparative Examples 1 to 2 A mixture layer composition was prepared by performing the same operation as in Example 1 except that the cross-linked polymer salt used as the active material and the binder was used as shown in Table 3 or Table 4.
  • the cross-linked polymer salt used as the active material and the binder was used as shown in Table 3 or Table 4.
  • natural graphite and silicon particles are stirred at 400 rpm for 1 hour using a planetary ball mill (F-5 made by FRITSCH), and a powdery crosslinked polymer is obtained in the obtained mixture.
  • 3.2 parts of Li salt R-1 was weighed, mixed well in advance, and then the same procedure as in Example 1 was carried out to prepare a mixture layer composition. The coatability and the 90 ° peel strength were evaluated for each mixture layer composition. The results are shown in Table 3 or Table 4.
  • an electrode mixture layer composition containing a binder for a non-aqueous electrolyte secondary battery electrode according to the present invention and an electrode manufactured using the same The coatability of each mixture layer composition (slurry) is good, and the peel strength between the mixture layer of the obtained electrode and the current collector is a high value in each case, and the binding property is excellent.
  • Example 12 a crosslinked polymer was stably obtained even under conditions of a high monomer concentration of 20%, and the binder containing the crosslinked polymer showed excellent binding properties.
  • cross-linked polymers (salts) R-21 and R-22 are examples in which the polymerization reaction was carried out in the absence of the organic amine compound, and the obtained cross-linked polymer was stable under high monomer concentration conditions. The properties were insufficient, and the average particle size and the particle size distribution were large. Further, even in the evaluation as these binders, sufficient binding properties were not obtained (Comparative Examples 1 and 2).
  • the binder for a non-aqueous electrolyte secondary battery electrode of the present invention exhibits excellent binding ability in the mixture layer, and therefore, a non-aqueous electrolyte secondary battery provided with an electrode obtained using the above-mentioned binder is excellent. It is expected to exhibit good durability (cycle characteristics), and is expected to be applied to automotive secondary batteries. Moreover, it is useful also for use of the active material containing a silicon

Abstract

L'invention fournit un liant à base d'eau pour batterie secondaire à électrolyte non aqueux, et une composition pour couche de mélange d'électrode de batterie secondaire à électrolyte non aqueux ainsi qu'une électrode de batterie secondaire à électrolyte non aqueux obtenues à l'aide de ce liant. Le liant de l'invention comprend un polymère réticulé ou un sel de celui-ci, lequel polymère réticulé contient une unité structurale dérivée d'un monomère d'acide carboxylique éthyléniquement insaturé, et est obtenu par polymérisation du composant monomère en présence d'un composé amine organique.
PCT/JP2018/026659 2017-07-21 2018-07-17 Liant pour électrode de batterie secondaire à électrolyte non aqueux, et application associée WO2019017317A1 (fr)

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WO2024024773A1 (fr) * 2022-07-27 2024-02-01 東亞合成株式会社 Procédé de fabrication de polymère réticulé ou de sel de celui-ci

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013080938A1 (fr) * 2011-11-29 2013-06-06 日本ゼオン株式会社 Électrode pour batterie secondaire lithium-ion, batterie secondaire lithium-ion, composition de bouillie et procédé de fabrication d'une électrode pour batterie secondaire lithium-ion
WO2015186363A1 (fr) * 2014-06-04 2015-12-10 日本ゼオン株式会社 Composition de liant pour électrode de batterie rechargeable au lithium-ion, composition de boue pour électrode de batterie rechargeable au lithium-ion, électrode de batterie rechargeable au lithium-ion, et batterie rechargeable au lithium-ion
JP2016031837A (ja) * 2014-07-29 2016-03-07 株式会社大阪ソーダ 電池電極用バインダー組成物、およびそれを用いた電極ならびに電池
WO2018043484A1 (fr) * 2016-08-31 2018-03-08 東亞合成株式会社 Liant destiné à des électrodes de batterie secondaire à électrolyte non aqueux et son utilisation

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100790833B1 (ko) * 2005-09-06 2008-01-02 주식회사 엘지화학 탄소 나노튜브 함유 복합체 바인더 및 이를 포함하는 리튬이차전지
JP5803070B2 (ja) * 2010-08-31 2015-11-04 日立化成株式会社 バインダ樹脂組成物、エネルギーデバイス用電極及びエネルギーデバイス
JP6202217B2 (ja) * 2014-10-21 2017-09-27 株式会社豊田自動織機 高分子化合物、中間組成物、負極電極、蓄電装置、負極電極用スラリー、高分子化合物の製造方法、及び負極電極の製造方法
JP6388145B2 (ja) * 2015-03-30 2018-09-12 東亞合成株式会社 非水電解質二次電池電極合剤層用組成物及びその製造方法、並びに、その用途
JP6651839B2 (ja) 2015-12-22 2020-02-19 日本ゼオン株式会社 非水系二次電池電極用バインダー組成物の製造方法、非水系二次電池電極用スラリー組成物の製造方法、非水系二次電池用電極の製造方法、および非水系二次電池の製造方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013080938A1 (fr) * 2011-11-29 2013-06-06 日本ゼオン株式会社 Électrode pour batterie secondaire lithium-ion, batterie secondaire lithium-ion, composition de bouillie et procédé de fabrication d'une électrode pour batterie secondaire lithium-ion
WO2015186363A1 (fr) * 2014-06-04 2015-12-10 日本ゼオン株式会社 Composition de liant pour électrode de batterie rechargeable au lithium-ion, composition de boue pour électrode de batterie rechargeable au lithium-ion, électrode de batterie rechargeable au lithium-ion, et batterie rechargeable au lithium-ion
JP2016031837A (ja) * 2014-07-29 2016-03-07 株式会社大阪ソーダ 電池電極用バインダー組成物、およびそれを用いた電極ならびに電池
WO2018043484A1 (fr) * 2016-08-31 2018-03-08 東亞合成株式会社 Liant destiné à des électrodes de batterie secondaire à électrolyte non aqueux et son utilisation

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