JP6651839B2 - Method for producing binder composition for non-aqueous secondary battery electrode, method for producing slurry composition for non-aqueous secondary battery electrode, method for producing electrode for non-aqueous secondary battery, and method for producing non-aqueous secondary battery - Google Patents

Description

  The present invention provides a method for producing a binder composition for a non-aqueous secondary battery electrode, a method for producing a slurry composition for a non-aqueous secondary battery electrode, a method for producing a non-aqueous secondary battery electrode, and a method for producing a non-aqueous secondary battery. It relates to a manufacturing method.

  Non-aqueous secondary batteries such as lithium ion secondary batteries (also sometimes referred to as power storage devices and electrochemical cells; sometimes simply referred to as “secondary batteries” hereinafter) are small, lightweight, and have an energy density. And has the property of being capable of repeated charge and discharge, and is used for a wide range of applications. Therefore, in recent years, improvements in battery members such as electrodes have been studied for the purpose of further improving the performance of non-aqueous secondary batteries.

  Here, an electrode for a secondary battery such as a lithium ion secondary battery usually includes a current collector and an electrode mixture layer formed on the current collector. The electrode mixture layer is formed, for example, by applying a slurry composition obtained by dispersing an electrode active material and a binder composition including a binder in a dispersion medium on a current collector, and drying the slurry composition. Is done.

  Therefore, in recent years, in order to further improve the performance of the secondary battery, attempts have been made to improve the binder composition used for forming the electrode mixture layer.

  For example, Patent Document 1 proposes a binder composition for a power storage device including a water-soluble polymer containing a repeating unit derived from acrylamide and / or methacrylamide and water. In Patent Document 1, by controlling the spinnability of the slurry composition for an electricity storage device prepared using the binder composition in a predetermined range, the electricity storage device can be connected to the space between the electrode active material and the current collector. The balance between adhesion and stable battery performance. Patent Literature 2 proposes to use a water-soluble resin containing acrylamide or the like as a binder used in an aqueous paste for an electrochemical cell. In Patent Document 2, by using an aqueous paste for an electrochemical cell in which the water-soluble resin is blended in a predetermined range, the paste exhibits sufficient adhesion to a current collector, an electrode active material, and the like, The manufactured electrochemical cells exhibit good battery characteristics. In Patent Documents 1 and 2, a binder composition and the like are prepared by neutralizing an aqueous solution used for a polymerization reaction of a water-soluble polymer.

WO 2015/008626 JP 2012-151108 A

  Here, when the aqueous solution used for the polymerization reaction of the water-soluble polymer is neutralized, generally, the water-soluble polymers are aggregated with each other, and the insoluble portion of the water-soluble polymer is likely to be generated in the aqueous solution. Are known. And the present inventors, when preparing a secondary battery binder composition and a secondary battery slurry composition while containing the insoluble portion of the water-soluble polymer, for example, coating the composition, When drying and forming the electrode mixture layer, attention was paid to the occurrence of pinholes and the like due to the insoluble components in the electrode mixture layer. That is, attention was paid to the problem that the porous structure of the electrode mixture layer constituting the electrode becomes non-uniform due to the insoluble matter.

  If such a porous structure becomes non-uniform, for example, when assembling a battery by injecting an electrolyte into a manufactured electrode, the injected electrolyte is unlikely to penetrate well into the electrode (electrolyte injection). It is considered that the battery performance deteriorates. Further, it is considered that when charging the manufactured battery, metal ions such as lithium are locally concentrated in the vicinity of the pinhole, so that the metal is likely to be deposited on the electrodes, thereby causing a problem that the electrodes are short-circuited.

  However, in a binder composition or the like prepared by a conventional technique, no attempt has been made to reduce the insoluble content of a water-soluble polymer, even though the solution of the water-soluble polymer is neutralized. Therefore, it has been required to reduce the insoluble content, to suppress the deterioration of the electrolyte solution injection property caused by the insoluble content, and to suppress the metal deposition on the electrode.

Accordingly, the present invention provides a good electrolyte solution injection property during battery assembly, and a high chargeability during charging while maintaining high adhesion between components in the electrode mixture layer and between the electrode mixture layer and the current collector. An object of the present invention is to provide a method for producing a binder composition for a non-aqueous secondary battery electrode, which is capable of producing a binder composition capable of simultaneously suppressing the metal deposition.
Further, the present invention is a method for manufacturing an electrode for a non-aqueous secondary battery capable of manufacturing an electrode capable of having a good electrolyte injection property, while maintaining the high adhesion, and used for manufacturing the electrode. It is an object of the present invention to provide a method for producing a slurry composition for a non-aqueous secondary battery electrode capable of producing a slurry composition to be obtained.
Further, an object of the present invention is to provide a method for manufacturing a non-aqueous secondary battery capable of manufacturing a secondary battery capable of suppressing metal deposition on an electrode during charging.

  The inventor of the present invention has conducted intensive studies for the purpose of solving the above problems. The present inventors have focused on preparing a binder composition by neutralizing a predetermined water-soluble polymer and then filtering the neutralized water-soluble polymer. The present inventor has determined that the ratio (insoluble fraction) of the solid content not dissolved in the solution contained in the binder composition having passed through the filtration step is within a predetermined range. It has been found that an electrode having excellent adhesion between the components in the layer and between the electrode mixture layer and the current collector and having good electrolyte injection properties can be produced. In addition, the present inventors have confirmed that by setting the insoluble fraction within a predetermined range, it is possible to manufacture a non-aqueous secondary battery capable of suppressing deposition of a metal on an electrode during charging. The present invention has been completed.

That is, an object of the present invention is to advantageously solve the above-mentioned problems, and a method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention includes a (meth) acrylamide monomer unit. A method for producing a binder composition for a non-aqueous secondary battery electrode containing a water-soluble polymer for a binder, comprising: a step (A) of neutralizing an aqueous solution containing a water-soluble polymer; and a neutralized water-soluble polymer. (B) obtaining a binder composition for a non-aqueous secondary battery electrode containing the water-soluble polymer for a binder by filtering an aqueous solution containing a water-soluble polymer for a binder. The insoluble fraction having a particle diameter of 1 μm or more based on the total solid content in the binder composition for use is 0.0001% by mass or more and 5.0% by mass or less. As described above, a binder composition containing a water-soluble polymer for a binder obtained by neutralizing and filtering a predetermined water-soluble polymer is obtained, and the insoluble fraction in the binder composition is suppressed to a predetermined range. It is possible to improve the adhesion and the electrolyte injection property of the electrode produced by using the binder composition. Further, when the manufactured secondary battery is charged, metal deposition on the electrode can be suppressed.
In the present invention, the “water-soluble polymer” refers to a polymer whose insoluble content is less than 1.0% by mass when 0.5 g of the polymer is dissolved in 100 g of water at a temperature of 50 ° C.
In the present application, “(meth) acryl” means acryl and / or methacryl.
In the present invention, the “insoluble fraction having a particle diameter of 1 μm or more” was used in the measurement test when the measurement test of the insoluble fraction was performed using a sheet-shaped filtration filter having a mesh size of 1 μm. It refers to the ratio of the insoluble solid content having a particle diameter of 1 μm or more (that is, the residue on the filtration filter) to the total solid content in the binder composition. Here, in the present invention, the “insoluble fraction” can be measured by the method described in Examples of the present specification.

Here, in the method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention, the weight-average molecular weight of the water-soluble polymer for a binder after the step (B) is 0.1 × 10 ⁶ or more and 20 × 10 ⁶ or more. It is preferably ⁶ or less. When the molecular weight of the water-soluble polymer for a binder is within the above range, the adhesiveness between the electrode mixture layer and the current collector in the produced electrode and the electrolyte injection property are further excellent.
In the present invention, the "weight average molecular weight" can be measured as a monodisperse pullulan conversion value as a standard substance, which is measured by gel permeation chromatography.

  And, it is preferable that the aperture of the filter medium used in the step (B) is 1 μm or more and 100 μm or less. If the polymer aqueous solution is filtered using a filter material having an opening within the above range, the adhesion of the produced electrode and the electrolyte injection property are further improved, and the charging in the manufactured secondary battery is performed. This is because metal precipitation at the time can be further suppressed.

  Another object of the present invention is to advantageously solve the above-mentioned problems, and a method for producing a slurry composition for a non-aqueous secondary battery electrode of the present invention comprises an electrode active material and a non-aqueous secondary battery electrode. A method for producing a slurry composition for a non-aqueous secondary battery electrode comprising a binder composition for a non-aqueous secondary battery electrode according to any one of the above-described methods for producing a binder composition for a non-aqueous secondary battery electrode. It is characterized by including a step of preparing a binder composition. As described above, if the slurry composition is manufactured using the binder composition obtained by the above-described manufacturing method, the adhesion and the electrolyte injection property of the electrode manufactured using the slurry composition can be improved. Can be something. Further, when the manufactured secondary battery is charged, metal deposition on the electrode can be suppressed.

And the manufacturing method of the slurry composition for non-aqueous secondary battery electrodes of the present invention is characterized in that the slurry composition for non-aqueous secondary battery electrodes comprises 10% by mass to 70% by mass of an aromatic vinyl monomer unit, It is preferable to further include a particulate polymer containing 20 to 80% by mass of an aliphatic diene monomer unit and 1 to 10% by mass of an ethylenically unsaturated carboxylic acid monomer unit. If a slurry composition further containing a particulate polymer having such a monomer unit content is used, the adhesion of the produced electrode and the electrolyte injection property are further improved. In addition, when the manufactured secondary battery is charged, metal deposition on the electrode can be further suppressed.
In the present invention, each “content ratio of monomer units” can be measured by using a nuclear magnetic resonance (NMR) method such as ¹ H-NMR.

  Further, in the method for producing a slurry composition for a non-aqueous secondary battery electrode of the present invention, the content ratio of the binder water-soluble polymer is based on the total content of the binder water-soluble polymer and the particulate polymer. Is preferably 10% by mass or more and 90% by mass or less. This is because if the content ratio of the water-soluble polymer for binder and the particulate polymer is in the above range, the adhesion of the produced electrode and the injectability of the electrolytic solution are further improved. In addition, when the manufactured secondary battery is charged, metal deposition on the electrode can be further suppressed.

  In addition, an object of the present invention is to solve the above-described problem advantageously, and a method of manufacturing an electrode for a non-aqueous secondary battery of the present invention includes forming an electrode mixture layer on a current collector. A method for producing an electrode for a non-aqueous secondary battery, comprising using the slurry composition for a non-aqueous secondary battery electrode prepared according to any of the above-described methods for producing a slurry composition for a non-aqueous secondary battery electrode. A step of forming the electrode mixture layer. As described above, when an electrode is manufactured using the slurry composition obtained by the above-described manufacturing method, the adhesiveness of the manufactured electrode and the electrolyte injection property become good. Further, when the manufactured secondary battery is charged, metal deposition on the electrode can be suppressed.

  Further, an object of the present invention is to advantageously solve the above problems, and a method of manufacturing a non-aqueous secondary battery of the present invention includes a positive electrode, a negative electrode, and a non-aqueous secondary battery including an electrolytic solution. A method for producing, characterized by including a step of producing at least one of the positive electrode and the negative electrode according to the method for producing an electrode for a non-aqueous secondary battery described above. As described above, when at least one of the positive electrode and the negative electrode is an electrode obtained by the manufacturing method of the present invention, the electrolyte penetrates into the electrode with good injectability during the manufacture of the secondary battery. Further, when the manufactured secondary battery is charged, metal deposition on the electrode can be suppressed.

According to the present invention, while maintaining high adhesion between the components in the electrode mixture layer, and between the electrode mixture layer and the current collector, good electrolyte injection properties during battery assembly, and during charging. It is possible to provide a method for producing a binder composition for a non-aqueous secondary battery electrode, which can produce a binder composition capable of simultaneously suppressing the metal deposition.
Further, according to the present invention, a method of manufacturing an electrode for a non-aqueous secondary battery capable of manufacturing an electrode capable of having the good electrolyte injection property while maintaining the high adhesion, and a method of manufacturing the electrode. A method for producing a slurry composition for a non-aqueous secondary battery electrode capable of producing a slurry composition used in the production can be provided.
Further, according to the present invention, it is possible to provide a method of manufacturing a non-aqueous secondary battery capable of manufacturing a secondary battery capable of suppressing metal deposition on an electrode during charging.

  Hereinafter, embodiments of the present invention will be described in detail.

(Production method of binder composition for non-aqueous secondary battery electrode)
The method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention is characterized by producing a binder composition containing a water-soluble polymer having (meth) acrylamide monomer unit as one component. In addition, the method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention includes a step (A) of neutralizing an aqueous solution containing a water-soluble polymer and a step of neutralizing the aqueous solution neutralized in the step (A). And a step (B) of filtering an aqueous solution containing the polymer, whereby a binder composition having a predetermined insoluble fraction is produced. Further, in the method for producing a binder composition for a non-aqueous secondary battery electrode according to the present invention, prior to the step (A), a water-soluble polymer containing a (meth) acrylamide monomer unit is prepared. Optionally, a step of preparing the coalescence can be included.

Here, the binder composition for a non-aqueous secondary battery electrode obtained by the production method of the present invention can be used when preparing a slurry composition for a non-aqueous secondary battery electrode.
And, since the binder composition for a non-aqueous secondary battery electrode obtained by the production method of the present invention has an insoluble fraction reduced to a predetermined range, the electrode produced using the binder composition has good properties. It has adhesion and electrolyte injectability. Further, in a secondary battery manufactured using the binder composition, metal deposition on the electrode during charging can be suppressed.
The method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention is particularly preferably used when producing a binder composition used for preparing a slurry composition for a non-aqueous secondary battery negative electrode. Can be.

<Preparation process of water-soluble polymer>
In the step of preparing a water-soluble polymer that can be arbitrarily included in the method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention, an aqueous solution containing a water-soluble polymer for performing neutralization and filtration described below is used. prepare. The composition of the water-soluble polymer to be prepared is not particularly limited except that it contains a (meth) acrylamide monomer unit, and other than a (meth) acrylamide monomer unit and a (meth) acrylamide monomer unit. And other monomer units.

<< Solvent >>
Here, examples of the solvent used for preparing the aqueous solution containing the water-soluble polymer include water such as ion-exchanged water. The solvent constituting the aqueous solution may be water or a mixed solution of water and a small amount of an organic solvent.

<< (meth) acrylamide monomer unit >>
The water-soluble polymer used in the method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention contains a (meth) acrylamide monomer unit. That is, the water-soluble polymer may contain only an acrylamide monomer unit, may contain only a methacrylamide monomer unit, or contains an acrylamide monomer unit and a methacrylamide monomer unit. May be. Above all, the water-soluble polymer preferably contains only acrylamide monomer units as (meth) acrylamide monomer units.
Here, the (meth) acrylamide monomer capable of forming the (meth) acrylamide monomer unit includes, for example, acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N, N-dimethylacrylamide and the like. Is mentioned. Among them, acrylamide is preferred. In addition, these may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

<< other monomer units >>
Other monomer units other than the (meth) acrylamide monomer unit that the water-soluble polymer can optionally contain are not particularly limited as long as they are monomer units that can be used in combination with the (meth) acrylamide monomer unit. Not done. Other monomer units include, for example, an ethylenically unsaturated carboxylic acid monomer unit, a (meth) acrylate monomer unit, a vinyl cyanide monomer unit, and an unsaturated monomer having a hydroxyalkyl group. Examples include a monomer unit, a di (meth) acrylate monomer unit, an aromatic vinyl monomer unit, and an aliphatic conjugated diene monomer unit. Among them, an ethylenically unsaturated carboxylic acid monomer unit is preferable. One of these other monomer units may be used alone, or two or more thereof may be combined in an arbitrary ratio.

  Here, examples of the ethylenically unsaturated carboxylic acid monomer capable of forming an ethylenically unsaturated carboxylic acid monomer unit include, for example, acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid And mono- or dicarboxylic acids (anhydrides). Among them, acrylic acid is preferred. As the ethylenically unsaturated carboxylic acid monomer, one type may be used alone, or two or more types may be combined in any ratio.

Examples of the (meth) acrylate monomer capable of forming the (meth) acrylate monomer unit include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, and t-butyl acrylate. Butyl acrylate such as butyl acrylate, octyl acrylate such as pentyl acrylate, hexyl acrylate, heptyl acrylate and 2-ethylhexyl acrylate, alkyl acrylate such as nonyl acrylate, decyl acrylate, lauryl acrylate, n-tetradecyl acrylate and stearyl acrylate; And methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate And butyl methacrylate such as t-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate such as 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, lauryl methacrylate, n-tetradecyl methacrylate, and alkyl methacrylate such as stearyl methacrylate. Esters and the like. Among them, alkyl acrylate is preferred, butyl acrylate and 2-ethylhexyl acrylate are more preferred, and butyl acrylate is still more preferred. As the (meth) acrylate monomer, one type may be used alone, or two or more types may be used in combination at an arbitrary ratio.
Examples of the vinyl cyanide-based monomer capable of forming the vinyl cyanide-based monomer unit include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethylacrylonitrile, and the like. Among them, acrylonitrile and methacrylonitrile are preferred, and acrylonitrile is more preferred. In addition, these may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.
Examples of the unsaturated monomer having a hydroxyalkyl group capable of forming an unsaturated monomer unit having a hydroxyalkyl group include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl Methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, di- (ethylene glycol) maleate, di- (ethylene glycol) itaconate, 2-hydroxyethyl maleate, bis (2-hydroxyethyl) Maleate, 2-hydroxyethyl methyl fumarate and the like can be mentioned. In addition, these may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.
Examples of the di (meth) acrylate monomer capable of forming a di (meth) acrylate monomer unit include ethylene dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, and 1,3. -Butylene glycol diacrylate and the like. In addition, these may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.
The aromatic vinyl monomer capable of forming the aromatic vinyl monomer unit is not particularly limited, and includes styrene, α-methylstyrene, vinyl toluene, divinylbenzene, and the like. In addition, one kind of aromatic vinyl monomer may be used alone, or two or more kinds may be used in combination at an arbitrary ratio.
The aliphatic conjugated diene monomer capable of forming the aliphatic conjugated diene monomer unit is not particularly limited, and 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3 -Dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, substituted linear conjugated pentadienes, substituted and side chain conjugated hexadienes, and the like. In addition, one kind of the aliphatic conjugated diene monomer may be used alone, or two or more kinds thereof may be used in combination at an arbitrary ratio.

  Here, the water-soluble polymer preferably contains the (meth) acrylamide monomer unit described above in an amount of 50% by mass or more based on the content of all monomer units contained in the water-soluble polymer. The content is more preferably 60% by mass or more, preferably 90% by mass or less, more preferably 80% by mass or less. When the content of the (meth) acrylamide monomer unit is within the above range, the dispersibility of the electrode active material in the prepared slurry composition is further improved, and the adhesion between the electrode mixture layer and the current collector is improved. Is also better.

<<< polymerization method of water-soluble polymer >>
The polymerization method of the water-soluble polymer is not particularly limited, and any method such as a solution polymerization method, a suspension polymerization method, a bulk polymerization method, and an emulsion polymerization method may be used. As the polymerization reaction, addition polymerization such as ionic polymerization, radical polymerization, and living radical polymerization can be used. The polymerization initiator, polymerization accelerator, emulsifier, dispersant, chain transfer agent, and the like used for the polymerization can be those commonly used, and the amount used is also generally used. Can be.

  The polymerization initiator that can be used for preparing the water-soluble polymer is not particularly limited, and includes known polymerization initiators, for example, sodium persulfate, ammonium persulfate, and potassium persulfate. Especially, it is preferable to use potassium persulfate. One of these may be used alone, or two or more may be used in combination at an arbitrary ratio.

  The polymerization accelerator is not particularly limited, and a known reducing polymerization accelerator, for example, tetramethylethylenediamine can be used.

  The emulsifier is not particularly limited, and may be a known emulsifier, for example, any of an anionic surfactant, a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant. Specific examples of anionic surfactants include sodium dodecyl sulfate such as sodium lauryl sulfate, ammonium dodecyl sulfate such as ammonium lauryl sulfate, sodium octyl sulfate, sodium decyl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, and sulfuric acid of higher alcohols such as sodium octadecyl sulfate. Ester salts; sodium dodecyl diphenyl ether disulfonate, sodium dialkyl succinate sulfonate, sodium lauryl benzene sulfonate, and other alkyl benzene sulfonates such as sodium hexadecyl benzene sulfonate; sodium dodecyl sulfonic acid, such as sodium lauryl sulfonate Sodium, sodium tetradecyl sulfonate Aliphatic sulfonates such as arm; and the like, may be a so-called reactive emulsifier having an unsaturated bond. One of these may be used alone, or two or more may be used in combination at an arbitrary ratio.

  The dispersant is not particularly limited, and a known dispersant, for example, sodium alkylbenzenesulfonate such as sodium dodecylbenzenesulfonate can be used. One type of dispersant may be used alone, or two or more types may be used in combination at an arbitrary ratio.

  The chain transfer agent is not particularly limited and includes, for example, alkyl mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, t-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-stearyl mercaptan; dimethyl; Xanthogen compounds such as xanthogen disulfide and diisopropylxanthogen disulfide; thiuram-based compounds such as terpinolene, tetramethylthiuram disulfide, tetraethylthiuram disulfide and tetramethylthiuram monosulfide; 2,6-di-t-butyl-4-methylphenol And phenolic compounds such as styrenated phenols; allyl compounds such as allyl alcohol; halogenated hydrocarbon compounds such as dichloromethane, dibromomethane and carbon tetrabromide ; Thioglycolic acid, thiomalate, 2-ethylhexyl thioglycolate, diphenylethylene, etc. α- methylstyrene dimer. Of these, alkyl mercaptans are preferred from the viewpoint of suppressing side reactions, and t-dodecyl mercaptan is more preferred. These may be used alone or in combination of two or more.

<Step (A)>
In the step (A) included in the method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention, the neutralized aqueous solution containing the water-soluble polymer obtained above is neutralized. A combined aqueous solution is obtained. At the time of the neutralization, the aqueous solution containing the water-soluble polymer to be neutralized is usually in the form of an aqueous solution dissolved in water, without any particular limitation.
Here, the neutralization is not particularly limited, and a commonly used neutralizing agent can be used. Typical neutralizing agents include, for example, ammonia, organic amines, potassium hydroxide, sodium hydroxide, lithium hydroxide and the like. Especially, it is preferable to use lithium hydroxide.
Further, the pH range of the aqueous solution containing the water-soluble polymer adjusted in the step (A) is preferably pH 6 or more, more preferably pH 6.5 or more, preferably pH 11 or less, more preferably pH 10 or less, and pH 9.5. The following are more preferred. This is because if the pH of the aqueous solution containing the water-soluble polymer is within the above range, the stability of the obtained binder composition is improved, and there is little change in physical properties such as viscosity during storage.

<Step (B)>
In the step (B) included in the method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention, an aqueous solution containing a neutralized water-soluble polymer obtained through the above-described step (A) is filtered. Thereby, a binder composition for a non-aqueous secondary battery electrode containing a water-soluble polymer for a binder containing a (meth) acrylamide monomer unit is obtained. That is, the step (B) is performed after the step (A). Further, the water-soluble polymer for a binder obtained in the step (B) is used as it is as a binder composition for a non-aqueous secondary battery electrode according to the method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention. Alternatively, it is used for preparing a binder composition for a non-aqueous secondary battery electrode.
The binder composition containing the water-soluble polymer for a binder obtained through the step (A) and the step (B) has been prepared using the binder composition because the insoluble fraction has been reduced to a predetermined range. The electrode has high adhesiveness, and the secondary battery manufactured using the binder composition can achieve both good electrolyte injection performance and suppression of metal deposition during charging.

<< Properties of water-soluble polymer for binder >>
Here, the weight-average molecular weight of the water-soluble polymer for a binder obtained through the step (B) is preferably 0.1 × 10 ⁶ or more, more preferably 1 × 10 ⁶ or more, and 5 × 10 ⁶ or more. It is still more preferably ⁶ or more, preferably 20 × 10 ⁶ or less, more preferably 17 × 10 ⁶ or less, even more preferably 15 × 10 ⁶ or less. If the weight-average molecular weight of the water-soluble polymer for a binder filtered in the step (B) is 0.1 × 10 ⁶ or more, a slurry composition prepared using the binder composition containing the water-soluble polymer for a binder is used. This is because the dispersibility of the electrode active material and the like in the slurry composition is improved. In addition, when an electrode is produced using the binder composition containing the water-soluble polymer, a high peel strength (adhesion) between the current collector and the electrode mixture layer can be obtained. If the weight-average molecular weight of the water-soluble polymer for a binder filtered in the step (B) is 20 × 10 ⁶ or less, the peel strength of an electrode produced using the binder composition containing the water-soluble polymer for a binder is used. This is because the electrolyte solution injection property of a secondary battery manufactured using the binder composition containing the water-soluble polymer for a binder further increases.

  The water-soluble polymer and the water-soluble polymer for a binder are usually contained in an aqueous solution before the step (A), a neutralized aqueous solution after the step (A), a binder composition, and a slurry composition described later. It has a non-particulate shape.

<< Binder composition for non-aqueous secondary battery electrode >>
The water-soluble polymer for a binder obtained through the steps (A) and (B) is used for preparing a binder composition according to the method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention. At this time, the obtained binder composition is not particularly limited except that it contains the above-mentioned water-soluble polymer for a binder containing a (meth) acrylamide monomer unit, and the water-soluble polymer for a binder may be used as it is. And other components other than the water-soluble polymer for a binder. Further, as the dispersion medium used for the binder composition, the dispersion medium used for any of the above-described water-soluble polymers may be used as it is.

[Other ingredients]
Examples of the other components include components such as a reinforcing material, a leveling agent, a viscosity modifier, and an electrolyte additive. These are not particularly limited as long as they do not affect the battery reaction, and known ones, for example, those described in International Publication WO 2012/115096 can be used. One of these components may be used alone, or two or more thereof may be used in combination at an arbitrary ratio.

[Properties of binder composition]
Here, the binder composition for a non-aqueous secondary battery electrode obtained by the production method of the present invention has an insoluble fraction having a particle diameter of 1 μm or more based on the total solid content in the binder composition of 0.0001% by mass or more. It needs to be 5.0% by mass or less. Further, the insoluble fraction having a particle diameter of 1 μm or more based on the total solid content in the binder composition is preferably 0.0005% by mass or more, more preferably 0.001% by mass or more. It is preferably at most 0 mass%, more preferably at most 1.0 mass%. If the insoluble fraction is 0.0001% by mass or more, the adhesion (peel strength) of the electrode produced using the binder composition can be further improved. Further, when the insoluble fraction is 5.0% by mass or less, the electrode active material and the like are more favorably dispersed in the slurry composition containing the binder composition. In addition, the flexibility and the electrolyte injection property of the electrode prepared using the binder composition are further improved, and the metal deposition in the manufactured secondary battery can be further suppressed.

Here, when the insoluble fraction having a particle diameter of 1 μm or more in the binder composition is within the above range, the adhesion of the produced electrode is increased, and the electrolyte injection property in the produced secondary battery is increased. Although it is not clear why metal precipitation can be suppressed and metal precipitation can be suppressed, it is presumed to be as follows.
That is, the fact that the insoluble fraction having a particle diameter of 1 μm or more in the binder composition is 0.0001% by mass or more means that in Step (B), a relatively high-molecular polymer is excessively removed by filtration. Indicates no. The relatively high molecular weight polymer is a polymer mainly responsible for binding properties and adhesion as a binder composition. Therefore, even after the step (B), since the polymer exhibiting the binding property and the adhesiveness is sufficiently present in the binder composition, the electrode manufactured using the binder composition is excellent. High adhesion can be exhibited.
The fact that the insoluble fraction having a particle diameter of 1 μm or more in the binder composition is 5.0 mass% or less indicates that only a sufficiently low proportion of the insoluble matter is present in the binder composition. Here, when the insoluble fraction in the binder composition is sufficiently low, when the electrode mixture layer is formed using the binder composition, in the electrode mixture layer, due to insoluble components. Generation of a concave portion such as a pinhole can be suppressed. That is, the formed electrode mixture layer can have a uniform porous structure. Then, when the electrolyte is brought into contact with the electrode on which the electrode mixture layer having the uniform porous structure is formed, the electrolyte, particularly the electrode mixture, is formed by the capillary phenomenon through the good porous structure. Good penetration into the layer. Therefore, it is possible to improve the electrolyte injectability of the manufactured electrode. Further, the uniform porous structure does not have a recess into which metal ions such as lithium ions enter. Therefore, even when the battery is charged / discharged, metal ions can be suppressed from being deposited during charging without uneven distribution of metal ions inside the battery.

<< filtration method >>
Here, in the method of filtering the aqueous solution containing the neutralized water-soluble polymer, which is performed in the step (B), the binder composition containing the obtained water-soluble polymer for a binder may have a predetermined insoluble fraction described above. There is no particular limitation as long as it has. In the filtration method in the step (B), for example, filtration can be performed using a filter material such as a filter having an arbitrary opening. In filtration, pressure filtration or reduced pressure filtration may be performed under an arbitrary pressure.
The filtration rate can be controlled, for example, by adjusting the pressure.

  Further, the aperture of the filter medium used for filtration is preferably 1 μm or more, preferably 100 μm or less, more preferably 30 μm or less, and further preferably 5 μm or less. If the aqueous solution containing the neutralized water-soluble polymer is filtered using a filter material having an opening of 1 μm or more, the resulting slurry composition prepared using the binder composition containing the water-soluble polymer for a binder can be used as a slurry. This is because the dispersibility of the electrode active material and the like in the composition is improved. In addition, if the opening of the filter medium is 1 μm or more, it is possible to prevent the removal of the polymer in a relatively high molecular region that exhibits the binding property and adhesion as the binder composition, and the water for the binder is prevented. This is because the adhesion (peel strength) of an electrode produced using a binder composition containing a soluble polymer can be further increased. In addition, if the aqueous solution containing the neutralized water-soluble polymer is filtered using a filter having a mesh size of 100 μm or less, a secondary battery manufactured using the binder composition containing the obtained water-soluble polymer for a binder is obtained. In this case, the electrolyte injection property can be further improved, and metal deposition during charging can be further suppressed.

(Method for producing slurry composition for non-aqueous secondary battery electrode)
The method for producing a slurry composition for a non-aqueous secondary battery electrode of the present invention is a method for producing a slurry composition containing an electrode active material and a binder composition for a non-aqueous secondary battery electrode. It is characterized by including a step of preparing a binder composition according to a method for producing a binder composition for an aqueous secondary battery electrode.
Here, the step of preparing the binder composition included in the method for producing a slurry composition for a non-aqueous secondary battery electrode of the present invention is the same as the method for producing a binder composition for a non-aqueous secondary battery electrode of the present invention described above. It is.

In addition, the method for producing a slurry composition for a non-aqueous secondary battery electrode of the present invention can produce a slurry composition by further adding a particulate polymer in addition to the electrode active material and the binder composition. . Further, the slurry composition for a non-aqueous secondary battery electrode obtained by the production method of the present invention can be used when producing a non-aqueous secondary battery electrode such as a positive electrode or a negative electrode.
Then, the slurry composition for a non-aqueous secondary battery electrode obtained by the production method of the present invention was prepared because the insoluble fraction was produced using a binder composition in which the insoluble fraction was reduced to a predetermined range. The electrode active material and the like are well dispersed in the slurry composition.
In addition, the method for producing a slurry composition for a non-aqueous secondary battery electrode of the present invention can be particularly suitably used when producing a slurry composition used for producing a negative electrode for a non-aqueous secondary battery.
In the following, a case where the slurry composition for a non-aqueous secondary battery electrode is a slurry composition for a negative electrode of a lithium ion secondary battery will be described as an example, but the present invention is not limited to the following example.

<Electrode active material>
The electrode active material is a material that transfers electrons at the electrode of the secondary battery. And, as the electrode active material for the lithium ion secondary battery, usually, a material capable of inserting and extracting lithium is used.

<< Negative electrode active material >>
The negative electrode active material is not specifically limited, and examples thereof include a carbon-based negative electrode active material, a metal-based negative electrode active material, and a negative electrode active material obtained by combining these.

Examples of the carbonaceous material include easily graphitic carbon and non-graphitizable carbon having a structure close to an amorphous structure represented by glassy carbon.
Here, as the graphitizable carbon, for example, a carbon material obtained from tar pitch obtained from petroleum or coal is used. Specific examples include coke, mesocarbon microbeads (MCMB), mesophase pitch-based carbon fibers, and pyrolysis vapor grown carbon fibers.
Examples of the non-graphitizable carbon include a phenol resin fired body, polyacrylonitrile-based carbon fiber, pseudo isotropic carbon, a furfuryl alcohol resin fired body (PFA), and hard carbon.

Furthermore, examples of the graphite material include natural graphite and artificial graphite.
Here, examples of artificial graphite include, for example, artificial graphite obtained by heat-treating carbon containing graphitizable carbon mainly at 2800 ° C. or more, graphitized MCMB heat-treated MCMB at 2000 ° C. or more, and mesophase pitch-based carbon fiber at 2000 ° C. Graphitized mesophase pitch-based carbon fibers heat-treated as described above can be mentioned.

  In addition, the metal-based negative electrode active material is an active material containing a metal, and usually includes an element into which lithium can be inserted, and has a theoretical electric capacity per unit mass of 500 mAh / in which lithium is inserted. The active material is g or more. As the metal-based active material, for example, a lithium metal, a simple metal capable of forming a lithium alloy (eg, Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P, Pb, Sb, Si, Sn) , Sr, Zn, Ti, etc.) and their alloys, and their oxides, sulfides, nitrides, silicides, carbides, phosphides and the like. Among these, an active material containing silicon (silicon-based negative electrode active material) is preferable as the metal-based negative electrode active material. The use of a silicon-based negative electrode active material can increase the capacity of a lithium ion secondary battery.

As the silicon-based negative electrode active material, for example, silicon (Si), an alloy containing silicon, SiO, SiO _x , a composite of a conductive carbon and a Si-containing material obtained by coating or complexing the conductive material with a conductive carbon And the like. One of these silicon-based negative electrode active materials may be used alone, or two or more thereof may be used in combination.
Above all, as the negative electrode active material, a carbon-based active material is preferable, a graphite material is more preferable, and artificial graphite is more preferable.

<Particulate polymer>
The particulate polymer that can be arbitrarily used in the method for producing a slurry composition is a polymer having a particulate shape in the slurry composition. In the present invention, the term “particulate polymer” refers to a polymer whose insoluble content becomes 90% by mass or more when 0.5 g of the polymer is dissolved in 100 g of water at 25 ° C.

<< composition of particulate polymer >>
The composition of the particulate polymer that the slurry composition may further include is not particularly limited, and includes, for example, an aromatic vinyl monomer unit, an aliphatic conjugated diene monomer unit, and an ethylenically unsaturated carboxylic acid monomer. Body unit, (meth) acrylamide monomer unit, (meth) acrylate monomer unit, vinyl cyanide-based monomer unit, hydroxyalkyl group-containing unsaturated monomer unit, di (meth) acryl And acid ester monomer units.
In addition, an aromatic vinyl monomer, an aliphatic conjugated diene monomer, an ethylenically unsaturated carboxylic acid monomer, a (meth) acrylamide monomer, and a (meth) acrylate which can form each monomer unit Examples of the monomer, vinyl cyanide monomer, unsaturated monomer containing a hydroxyalkyl group, and di (meth) acrylate monomer include those exemplified in the case of the water-soluble polymer described above. Similar monomers may be mentioned. In addition, these may be used individually by 1 type, and may be used in combination of 2 types.

  Among the above-mentioned monomers, the composition of the particulate polymer preferably contains an aromatic vinyl monomer unit, an aliphatic diene monomer unit, or an ethylenically unsaturated carboxylic acid monomer unit, It is more preferable to include all of an aromatic vinyl monomer unit, an aliphatic diene monomer unit, and an ethylenically unsaturated carboxylic acid monomer unit. Specifically, the composition of the particulate polymer preferably contains styrene, 1,3-butadiene, or itaconic acid, and more preferably contains all of styrene, 1,3-butadiene, and itaconic acid. .

Here, the content ratio of the aromatic vinyl monomer unit in the particulate polymer is preferably 10% by mass or more, more preferably 20% by mass or more, based on the content of the entire polymer of the particulate polymer. It is more preferably at least 70 mass%, more preferably at most 70 mass%, more preferably at most 60 mass%, even more preferably at most 55 mass%. When the content ratio of the aromatic vinyl monomer unit in the particulate polymer is 10% by mass or more, by using the slurry composition further containing the particulate polymer due to the contribution of the aromatic vinyl monomer unit. This is because the adhesion (peel strength) of the manufactured electrode can be further improved. Further, if the content ratio of the aromatic vinyl monomer unit in the particulate polymer is 70% by mass or less, the flexibility of the produced electrode can be further improved.
Further, the content ratio of the aliphatic diene monomer unit in the particulate polymer is preferably 20% by mass or more, more preferably 30% by mass or more, and more preferably 40% by mass, based on the content of the whole polymer of the particulate polymer. %, More preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 65% by mass or less. When the content ratio of the aliphatic diene monomer unit in the particulate polymer is 20% by mass or more, by using the slurry composition further containing the particulate polymer due to the contribution of the aliphatic diene monomer unit. This is because the flexibility of the manufactured electrode can be further improved. Further, if the content of the aliphatic diene monomer unit in the particulate polymer is 80% by mass or less, the adhesion (peel strength) of the produced electrode can be further improved.
Further, the content ratio of the ethylenically unsaturated carboxylic acid monomer unit in the particulate polymer is preferably 1% by mass or more, more preferably 1.5% by mass or more based on the content of the whole polymer of the particulate polymer. It is more preferably at least 2% by mass, more preferably at most 10% by mass, more preferably at most 7% by mass, even more preferably at most 5% by mass. When the content of the ethylenically unsaturated carboxylic acid monomer unit in the particulate polymer is 1% by mass or more, the dispersibility of the electrode active material and the like in the slurry composition further containing the particulate polymer is increased. Because it can be higher. In addition, the electrolyte injectability of the manufactured secondary battery can be further improved, and metal deposition can be further suppressed. When the content of the ethylenically unsaturated carboxylic acid monomer unit in the particulate polymer is 10% by mass or less, the flexibility and adhesion (peel strength) of the produced electrode can be further improved. It is.

<Preparation of slurry composition for negative electrode of non-aqueous secondary battery>
The slurry composition for a non-aqueous secondary battery negative electrode is obtained by mixing the above-mentioned electrode active material, binder composition, and any particulate polymer in a solvent such as water and / or an organic solvent such as N-methylpyrrolidone. It can be prepared by dissolving or dispersing. Specifically, a ball mill, a sand mill, a bead mill, a pigment disperser, a crusher, an ultrasonic disperser, a homogenizer, a planetary mixer, by mixing the above components and a solvent using a mixer such as a fill mix. , A slurry composition can be prepared. In addition, you may use the solvent contained in the above-mentioned binder composition as a solvent used for preparation of a slurry composition.

  Here, the content ratio of each polymer when preparing the slurry composition, the content of the binder water-soluble polymer with respect to the total content of the binder water-soluble polymer and the particulate polymer obtained above. The ratio is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, preferably 90% by mass or less, and more preferably 80% by mass or less. More preferably, it is preferably 70% by mass or less. When the content of the water-soluble polymer for binder is 10% by mass or more, the dispersibility of the electrode active material and the like in the slurry composition can be further improved by the contribution of the water-soluble polymer for binder. In addition, the electrolyte injectability of the manufactured secondary battery can be further improved, and metal deposition can be further suppressed. When the content of the water-soluble polymer for a binder is 90% by mass or less, the flexibility and adhesion (peel strength) of the produced electrode can be further improved by the contribution of the particulate polymer that can be used in combination. It is.

(Method of manufacturing electrode for non-aqueous secondary battery)
The method for producing an electrode for a non-aqueous secondary battery of the present invention is a method for producing an electrode for a non-aqueous secondary battery, comprising forming an electrode mixture layer on a current collector, wherein A step of forming the electrode mixture layer using the slurry composition for a non-aqueous secondary battery electrode prepared according to the method.
Here, the method for producing a slurry composition used in the step of forming an electrode mixture layer, which is included in the method for producing an electrode for a non-aqueous secondary battery of the present invention, comprises the above-described electrode for a non-aqueous secondary battery of the present invention. The method is the same as the method for producing a slurry composition for use.
The electrode for a non-aqueous secondary battery obtained by the manufacturing method of the present invention is manufactured using a slurry composition having an insoluble fraction reduced to a predetermined range, so that it has high flexibility and high adhesion. Properties (peel strength) and high electrolyte injection properties.
In the following, a case where the electrode for a non-aqueous secondary battery is a negative electrode for a lithium ion secondary battery will be described as an example, but the present invention is not limited to the following example.

<Current collector>
Here, as the current collector, a material having electrical conductivity and being electrochemically durable is used. Specifically, for example, a current collector made of a metal material such as iron, copper, aluminum, nickel, stainless steel, titanium, tantalum, gold, and platinum can be used as the current collector. One of the above materials may be used alone, or two or more thereof may be used in combination at an arbitrary ratio.

<Formation of negative electrode mixture layer>
The negative electrode is, for example, a step of applying the above-described negative electrode slurry composition on a current collector (application step), and drying the negative electrode slurry composition applied on the current collector by drying the negative electrode slurry composition. To form a negative electrode mixture layer (drying step).

<< Coating process >>
The method for applying the slurry composition for a negative electrode on a current collector is not particularly limited, and a known method can be used. Specifically, as a coating method, a doctor blade method, a dip method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, a brush coating method, or the like can be used. At this time, the negative electrode slurry composition may be applied to only one surface of the current collector, or may be applied to both surfaces. The thickness of the slurry film on the current collector after coating and before drying can be appropriately set according to the thickness of the negative electrode mixture layer obtained by drying.

<< Drying process >>
The method for drying the slurry composition for a negative electrode on the current collector is not particularly limited, and a known method can be used. For example, a hot air, a hot air, a drying method with a low-humidity air, a vacuum drying method, an infrared ray or an electron beam. Drying method by irradiation. By drying the slurry composition for a negative electrode on the current collector in this way, a negative electrode mixture layer is formed on the current collector, and a negative electrode including the current collector and the negative electrode mixture layer can be obtained.

  After the drying step, the negative electrode mixture layer may be subjected to a pressure treatment using a mold press or a roll press. The pressure treatment can improve the adhesion between the negative electrode mixture layer and the current collector. When the negative electrode mixture layer contains a curable polymer, it is preferable to cure the polymer after forming the negative electrode mixture layer.

(Method of manufacturing non-aqueous secondary battery)
The method for producing a non-aqueous secondary battery of the present invention includes a positive electrode, a negative electrode, and an electrolytic solution, and at least one of the positive electrode and the negative electrode is produced according to the method for producing an electrode for a non-aqueous secondary battery described above. It is characterized by including a step of forming a battery electrode. That is, the secondary battery obtained by the production method of the present invention may be configured such that the positive electrode of the secondary battery is the electrode of the present invention and the negative electrode is another known negative electrode, and the negative electrode of the secondary battery is the electrode of the present invention. The positive electrode may be another known positive electrode, and both the positive electrode and the negative electrode of the secondary battery may be the electrode of the present invention. Especially, it is preferable that the negative electrode of a secondary battery is the electrode of the present invention.
In addition, the method for producing a non-aqueous secondary battery of the present invention may further include a known battery such as a separator other than the positive electrode, the negative electrode, and the electrolyte, which separates the positive electrode and the negative electrode to prevent a short circuit between the positive electrode and the negative electrode. A member may be included. Then, without particular limitation, for example, a secondary battery can be manufactured by putting these battery members in a known battery container and passing through a known assembly process.
And since the non-aqueous secondary battery obtained by the manufacturing method of the present invention includes the electrode obtained according to the manufacturing method of the present invention, it is suppressed that metal is deposited on the electrode during charging, and the It can show battery characteristics.

<Positive electrode>
As the positive electrode, a known positive electrode can be used. Specifically, the positive electrode is not particularly limited, and a positive electrode having a current collector and a positive electrode mixture layer formed on the current collector can be used. The positive electrode mixture layer usually contains a positive electrode active material, a conductive additive, and a binder.
Here, the current collector, the positive electrode active material in the positive electrode mixture layer, the conductive additive, and the binder, and, for the method of forming the positive electrode mixture layer on the current collector, use a known method For example, those described in JP-A-2013-145763 can be used.

[Active material for positive electrode]
Specific examples of the positive electrode active material include, but are not particularly limited to, lithium-containing cobalt oxide (LiCoO ₂ ), lithium manganate (LiMn ₂ O ₄ ), lithium-containing nickel oxide (LiNiO ₂ ), and Co— lithium-containing composite oxide of Ni-Mn (Li (Co Mn Ni) O 2), lithium-containing composite oxide of Ni-Mn-Al, lithium-containing composite oxide of Ni-Co-Al, olivine-type lithium iron phosphate (LiFePO _4), olivine-type lithium manganese phosphate _{(LiMnPO 4), Li 2 MnO} 3 -LiNiO 2 solid _{solution, Li 1 + x Mn 2-} x O 4 (0 <X <2) lithium excess represented by Known positive electrode active materials such as spinel compounds, Li [Ni _0.17 Li _0.2 Co _0.07 Mn _0.56 ] O ₂ , and LiNi _0.5 Mn _1.5 O ₄ can be used.
The amount and particle size of the positive electrode active material are not particularly limited, and may be the same as those of the conventionally used positive electrode active material.

[Conduction aid]
Examples of the conductive aid include particulate carbon materials such as carbon black and acetylene black; vapor-grown carbon fibers, carbon fibers obtained by carbonizing organic fibers, and fibrous carbon materials such as carbon nanotubes. . Among them, acetylene black is preferable as the conductive assistant. One of these may be used alone, or two or more may be used in combination at an arbitrary ratio.
The amounts of the positive electrode active material and the conductive additive are not particularly limited, and may be the same as those of the conventionally used positive electrode active material and the conductive additive.

[Binder]
Further, the binder is not particularly limited, and a known binder other than the above-described water-soluble polymer and particulate polymer can be used. Specific examples include a fluorine-containing polymer. Among the fluorine-containing polymers, polyvinylidene fluoride is preferred. One of these may be used alone, or two or more may be used in combination at an arbitrary ratio.
The amount of the binder is not particularly limited, and may be the same as that of a conventionally used binder.

<Electrolyte>
As the electrolyte, an organic electrolyte obtained by dissolving a supporting electrolyte in an organic solvent is usually used. For example, when the non-aqueous secondary battery is a lithium ion secondary battery, a lithium salt is used as a supporting electrolyte. Examples of the lithium salt include LiPF ₆ , LiAsF ₆ , LiBF ₄ , LiSbF ₆ , LiAlCl ₄ , LiClO ₄ , CF ₃ SO ₃ Li, C ₄ F ₉ SO ₃ Li, CF ₃ COOLi, (CF ₃ CO) ₂ NLi , (CF ₃ SO ₂ ) ₂ NLi, (C ₂ F ₅ SO ₂ ) NLi and the like. Among them, LiPF ₆ , LiClO ₄ , and CF ₃ SO ₃ Li are preferable, and LiPF ₆ is particularly preferable because they are easily soluble in a solvent and show a high degree of dissociation. One type of electrolyte may be used alone, or two or more types may be used in combination at an arbitrary ratio. In general, the higher the dissociation degree of the supporting electrolyte is, the higher the lithium ion conductivity tends to be.

The organic solvent used for the electrolytic solution is not particularly limited as long as it can dissolve the supporting electrolyte. For example, dimethyl carbonate (DMC), ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC ), Butylene carbonate (BC), carbonates such as ethyl methyl carbonate (EMC); esters such as γ-butyrolactone and methyl formate; ethers such as 1,2-dimethoxyethane and tetrahydrofuran; and sulfolane and dimethyl sulfoxide. Sulfur compounds; and the like are preferably used. Further, a mixture of these solvents may be used. Among them, carbonates are preferably used because they have a high dielectric constant and a wide stable potential region, and more preferably a mixture of ethylene carbonate and ethyl methyl carbonate is used.
In addition, known additives such as vinylene carbonate (VC), fluoroethylene carbonate (FEC), and ethyl methyl sulfone may be added to the electrolytic solution.

<Separator>
The separator is not particularly limited. For example, a microporous film using a polyolefin (polyethylene, polypropylene, polybutene, polyvinyl chloride) resin, polyethylene terephthalate, polycycloolefin, polyether sulfone, polyamide, polyimide, Examples include microporous membranes using resins such as polyimide amide, polyaramid, polycycloolefin, nylon, and polytetrafluoroethylene, woven or nonwoven fabrics using polyolefin fibers, and aggregates of particles made of an insulating material. . Among them, it is possible to reduce the thickness of the entire separator, thereby increasing the ratio of the electrode mixture layer in the non-aqueous secondary battery to increase the capacity per volume. A microporous membrane using a polyolefin (polyethylene, polypropylene, polybutene, polyvinyl chloride) resin is preferred. Among them, a microporous film made of a polypropylene resin is more preferable.

<Assembly process>
In the method for manufacturing a non-aqueous secondary battery of the present invention, the non-aqueous secondary battery can be manufactured using a known assembly method without any particular limitation. Specifically, in the method for producing a non-aqueous secondary battery of the present invention, for example, the negative electrode, the positive electrode, and the separator obtained above are wound into a battery shape as necessary, folded, or the like to form a battery container. The non-aqueous secondary battery can be manufactured by putting the battery, filling the battery container with an electrolytic solution, and sealing the battery. A fuse, an overcurrent prevention element such as a PTC element, an expanded metal, a lead plate, and the like may be provided as necessary in order to prevent an increase in the internal pressure of the nonaqueous secondary battery and the occurrence of overcharging and discharging. . The shape of the secondary battery may be, for example, any of a coin type, a button type, a sheet type, a cylindrical type, a square type, a flat type, and the like.

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. In the following description, “%” and “parts” representing amounts are based on mass unless otherwise specified.
In Examples and Comparative Examples, the weight average molecular weight of the water-soluble polymer for a binder, the insoluble fraction having a particle diameter of 1 μm or more in the binder composition, the dispersion stability of the slurry composition, the flexibility of the electrode, and the adhesion of the electrode The properties, the electrolyte pouring properties of the electrodes in the secondary battery, and the lithium metal deposition rate in the secondary battery were calculated, measured and evaluated by the following methods.

<Weight average molecular weight>
The weight average molecular weight of the water-soluble polymer for a binder was measured using a gel permeation chromatograph (GPC). Specifically, what was adjusted to a solid content of 1% by mass was used as a measurement sample. Then, a calibration curve was prepared using the standard substance, thereby calculating the weight average molecular weight as a standard substance conversion value. The measurement conditions are as follows. Table 1 shows the results.
Apparatus: Gel permeation chromatograph (Tosoh Corporation, pump: product name "DP-8020", autosampler: product name "AS-8020", detector: product name "RI-8020")
Column: Showa Denko KK, product name "Shodex OHpak (SB-G, SB-807HQ, SB-806MHQ)"
Mobile phase: 0.1 M Tris buffer (pH 9.0) + 0.1 M potassium chloride Flow rate: 0.5 mL / min Injection volume: 0.2 mL
Temperature: 40 ° C
Detector: Differential refractive index detector (RI)
Reference material: monodisperse pullulan

<Insoluble fraction>
The insoluble fraction of 1 μm or more in the binder composition was calculated by the following method. Specifically, a sheet-shaped filtration filter having an opening of 1 μm was weighed in advance, and the weighed weight was designated as C. Next, 1000 g (5 g of solid content) of a sample of the prepared binder composition for a non-aqueous secondary battery electrode having a solid content of 0.5% by mass was transferred onto a weighed filter, and the weight of the sample itself was reduced. And filtered. After filtration, the filter was dried under reduced pressure (gauge pressure: -0.05 MPa or less, temperature: 110 ° C., drying time: 3 hours), and the filter after drying under reduced pressure was weighed.
Then, the following calculation formula (I):
Insoluble fraction (% by mass) = (B−C) ÷ A × 100 (I)
A is the total solid content in the sample of the binder composition,
B is the mass of the filter dried under reduced pressure after filtration,
C is the mass of the filter before filtration,
Was calculated as an insoluble fraction of 1 μm or more.
In addition, this measurement was performed on the binder composition which passed only step (A) in Comparative Example 2, and on the binder composition which passed through step (A) after step (B) in Comparative Example 4. went. Table 1 shows the results.

<Dispersion stability of slurry composition>
The dispersion stability of the slurry composition was evaluated as a dispersibility of the electrode active material in the slurry composition using a gauge (grain gauge) based on JIS K5600-2-5: 1999. Specifically, the third largest particle size among the streaks generated on the gauge was measured, and the measurement was performed six times. The maximum value among the measured values was regarded as the particle size of the slurry composition, and was determined according to the following criteria. The smaller the particle size, the better the dispersion stability of the particles in the slurry composition. Table 1 shows the results.
A: Particle size is less than 30 μm B: Particle size is 30 μm or more and less than 40 μm C: Particle size is 40 μm or more and less than 50 μm D: Particle size is 50 μm or more and less than 60 μm E: Particle size is 60 μm or more

<Flexibility of electrode>
The manufactured electrode was cut into a rectangle having a width of 1 cm and a length of 10 cm to obtain a test piece. The obtained test pieces were wound around SUS rods of various diameters so that the rods became the axis. The flexibility was determined from the diameter at which cracks occurred on the wound electrode surface according to the following criteria. The smaller the diameter at which the crack occurred on the electrode surface, the higher the flexibility of the electrode. Table 1 shows the results.
A: The diameter is less than 3.0 mm B: The diameter is 3.0 mm or more and less than 3.5 mm C: The diameter is 3.5 mm or more and less than 4.0 mm D: The diameter is 4.0 mm or more and less than 4.5 mm E: The diameter is 4.0. 5mm or more

<Adhesion of electrode>
The adhesion of the electrode was measured as the peel strength of the negative electrode as follows. Specifically, each of the manufactured negative electrodes was cut into a rectangle having a width of 1 cm and a length of 10 cm to obtain test pieces. The obtained test piece was fixed with the surface of the negative electrode mixture layer facing upward. After attaching a cellophane tape to the surface of the negative electrode mixture layer of the fixed test piece, the stress was measured when the cellophane tape was peeled off from one end of the test piece at a speed of 50 mm / min in the 180 ° direction. The same measurement was performed ten times, and the average value was defined as the peel strength, and the evaluation was made according to the following criteria. The higher the peel strength, the higher the adhesion of the electrode (negative electrode). Table 1 shows the results.
A: Peel strength of 6 N / m or more B: Peel strength of 5 N / m or more and less than 6 N / m C: Peel strength of 4 N / m or more and less than 5 N / m D: Peel strength of 3 N / m or more and less than 4 N / m E: Peel strength less than 3N / m

<Electrolyte injection property>
The manufactured negative electrode for a lithium ion secondary battery was punched into a diameter of 12 mm. Next, 10 μL of the electrolytic solution was dropped on the surface of the negative electrode mixture layer of the punched negative electrode. Then, the time until the dripping liquid permeated was measured visually using a magnifying camera. As the electrolyte, a LiPF ₆ solution having a concentration of 1.0 M (solvent: mixed solvent of ethylene carbonate / ethyl methyl carbonate = 3/7 (volume ratio), additive: vinylene carbonate 2 mass% (solvent ratio)) used. Then, the determination was made based on the following criteria. The shorter the time it takes for the dripping liquid to soak, the higher the electrolyte injection property. Table 1 shows the results.
A: Time to soak is less than 60 seconds B: Time to soak is 60 seconds to less than 90 seconds C: Time to soak is 90 to less than 120 seconds D: Time to soak E is 120 seconds or more and less than 150 seconds E: The time to soak is 150 seconds or more

<Metal deposition rate>
The metal deposition rate on the electrode during charging of the secondary battery was measured as a lithium deposition area ratio on the negative electrode by the following method. Specifically, the manufactured lithium ion secondary battery was fully charged to a depth of charge (SOC) of 100% at a constant current of 1 C under an environment of 20 ° C. Then, the fully charged secondary battery is disassembled, the negative electrode is taken out, and the area ratio of lithium deposited on the surface of the negative electrode mixture layer is calculated by the following formula (II):
Lithium deposition area ratio (%) = (area of deposited lithium / area of negative electrode mixture layer surface) × 100 (II)
It calculated according to. And it evaluated based on the following criteria. The lower the lithium deposition area ratio, the better the secondary battery. Table 1 shows the results.
A: Lithium deposition area ratio is less than 2% B: Lithium deposition area ratio is 2% or more and less than 5% C: Lithium deposition area ratio is 5% or more and less than 10% D: Lithium deposition area ratio is 10% or more and less than 15% E : Lithium deposition area ratio is 15% or more

(Example 1)
<Production of binder composition for non-aqueous secondary battery electrode>
<< Preparation process of water-soluble polymer >>
789 parts of ion-exchanged water were charged into a glass 1 L flask, heated to a temperature of 40 ° C., and the inside of the flask was replaced with nitrogen gas at a flow rate of 100 mL / min. Next, 30 parts of acrylic acid and 70 parts of acrylamide were mixed and injected into the flask with a syringe. Thereafter, 8.9 parts of a 2.5% aqueous solution of potassium persulfate as a polymerization initiator was added into the flask with a syringe to start a polymerization reaction. Further, 15 minutes after the start of the polymerization reaction, 22.2 parts of a 2.0% aqueous solution of tetramethylethylenediamine as a polymerization accelerator was added by a syringe.
Four hours after the addition of the polymerization initiator, 4.4 parts of a 2.5% aqueous solution of potassium persulfate as a polymerization initiator was added to the flask, and 2.0% of tetramethylethylenediamine as a polymerization accelerator was further added. 11.1 parts of an aqueous solution was added, and the temperature was raised to and maintained at 60 ° C., and the polymerization reaction was allowed to proceed. 3 hours after the addition of the polymerization initiator, the flask is opened to the air to stop the polymerization reaction, the polymerization product is deodorized at a temperature of 80 ° C., and the residual monomer is removed, thereby containing the water-soluble polymer. An aqueous solution was obtained.
<<< Step (A) >>>
Thereafter, the pH of the aqueous solution containing the water-soluble polymer obtained in the above-mentioned step of preparing the water-soluble polymer is adjusted to 8 using a 5% aqueous solution of lithium hydroxide, thereby neutralizing the water-soluble polymer. An aqueous solution containing the polymer was obtained.
<<< Step (B) >>>
The aqueous solution containing the neutralized water-soluble polymer obtained in the above step (A) was charged into a pressurized tank having a design pressure for use of 0.8 MPa. A hose was connected to the tank discharge port, and a filtration housing as a filtering material was further connected to the hose. Further, a filter cartridge having a mesh size of 2 μm (99% capture specification, manufactured by Loki Techno Co., Ltd., product name “MAP Series”) was installed in the filtration housing. The pressurized tank was pressurized with nitrogen, and the aqueous solution containing the neutralized water-soluble polymer was filtered to obtain an aqueous solution containing the water-soluble polymer for a binder. The filtration rate was controlled by the nitrogen pressure value.
Then, using the obtained aqueous solution containing the water-soluble polymer for a binder, the weight average molecular weight of the water-soluble polymer for a binder was measured by the method described above. Table 1 shows the results.
Subsequently, the obtained aqueous solution containing the water-soluble polymer for a binder was used as a binder composition as it was, and the insoluble fraction having a particle diameter of 1 μm or more in the binder composition was measured by the method described above. Table 1 shows the results.

<Production of slurry composition for non-aqueous secondary battery electrode>
<< Preparation of particulate polymer >>
In a 5 MPa pressure vessel equipped with a stirrer, 50 parts of styrene as an aromatic vinyl monomer, 47 parts of 1,3-butadiene as an aliphatic conjugated diene monomer, and 3 parts of itaconic acid as an ethylenically unsaturated carboxylic acid monomer Then, 4 parts of sodium dodecylbenzenesulfonate as an emulsifier, 150 parts of ion-exchanged water, 0.4 part of t-dodecylmercaptan as a chain transfer agent, and 0.5 part of potassium persulfate as a polymerization initiator were added. Then, the mixture was heated to 50 ° C. to initiate polymerization. The polymerization reaction was continued at 50 ° C., and when the polymerization conversion reached 96%, the mixture was cooled and the polymerization reaction was stopped to obtain a particulate polymer.

<< Preparation of slurry composition for negative electrode >>
In a planetary mixer with a disper, 98 parts of artificial graphite (specific surface area: 3.2 m ² / g, volume average particle diameter: 16 μm) as a negative electrode active material, and water solubility for a binder as a binder composition obtained as described above One part of the polymer corresponding to the solid content was added. Then, the mixture was adjusted to a solid concentration of 56% with ion-exchanged water, and then mixed at 25 ° C. for 60 minutes.
Next, the mixture is adjusted to a solid content concentration of 52% with ion-exchanged water to obtain an intermediate dilution mixture, and then further mixed at 25 ° C. for 15 minutes to contain the negative electrode active material and the water-soluble polymer for a binder. A mixture was obtained.
Next, 1 part of the particulate polymer obtained above is added to the mixture at a solid content equivalent (that is, the content ratio of the binder water-soluble polymer is the sum of the binder water-soluble polymer and the particulate polymer). (50% by mass of the content), and adjusted with ion-exchanged water so that the final solid content concentration was 48%, and the mixture was further mixed for 10 minutes. By defoaming the mixed solution under reduced pressure, a slurry composition for a negative electrode containing a negative electrode active material, a water-soluble polymer for a binder, and a particulate polymer was obtained.
Then, using the obtained slurry composition for a negative electrode, the dispersion stability of the slurry composition was evaluated by the above-described method. Table 1 shows the results.

<Production of electrodes for non-aqueous secondary batteries>
<< Negative electrode >>
The negative electrode slurry composition obtained in the above, a comma coater onto a copper foil (thickness 15 [mu] m) as a current collector, so that the coat-weight after drying of 9mg / cm ² ~10mg / cm ² And dried. The drying was performed by transporting the copper foil coated with the negative electrode slurry composition at a speed of 0.5 m / min for 2 minutes into an oven at 70 ° C. Thereafter, the current collector having the dried slurry composition for a negative electrode was further subjected to heat treatment at 120 ° C. for 2 minutes to obtain a negative electrode raw material.
Next, the obtained negative electrode raw material was pressed by a roll press machine so that the density became 1.50 g / cm ^{3 to} 1.60 g / cm ³ , thereby forming a negative electrode having a negative electrode mixture layer formed on one surface. I got
And about the manufactured negative electrode, the flexibility as an electrode, adhesiveness, and electrolyte injection property were evaluated by the above-mentioned method. Table 1 shows the results.

<Manufacture of non-aqueous secondary batteries>
<< Positive electrode >>
100 parts of LiCoO ₂ as a positive electrode active material, ₂ parts of acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd., product name “HS-100”) as a conductive additive, and polyvinylidene fluoride (polyvinylidene fluoride) as a binder 2 parts of PVDF (product name “KF-1100” manufactured by Kureha Chemical Co., Ltd.) were added, and N-methylpyrrolidone was further added and mixed so that the total solid content concentration became 67%, thereby preparing a slurry for the positive electrode. A composition was obtained.
Then, the obtained slurry composition for the positive electrode was used. It was applied on an aluminum foil (thickness: 20 μm) as a current collector with a comma coater and dried. The drying was performed by transporting the aluminum foil coated with the slurry composition for a positive electrode at a speed of 0.5 m / min for 2 minutes in an oven at 60 ° C. Thereafter, the current collector having the dried slurry composition for the positive electrode was further subjected to a heat treatment at 120 ° C. for 2 minutes to obtain a positive electrode raw material.
By density obtained positive electrode raw by a roll press machine is pressed to the ^{3.10g / cm 3 ~3.20g / cm 3} , a positive electrode mixture layer is formed on one side Obtained.
<< Assembly of lithium ion secondary battery >>
A single-layer polypropylene separator (width 65 mm, length 500 mm, thickness 25 μm; manufactured by a dry method; porosity 55%) was prepared and cut into a square of 5 cm × 5 cm. In addition, an aluminum packaging exterior was prepared as the exterior of the battery.
Then, the positive electrode manufactured as described above was cut out into a square of 4 cm × 4 cm, and arranged so that the surface on the side of the current collector was in contact with the aluminum package exterior. Next, the square separator was arranged on the surface of the positive electrode on the side of the positive electrode mixture layer. Further, the negative electrode manufactured as described above was cut into a 4.2 cm × 4.2 cm square, and placed on the separator such that the surface of the negative electrode mixture layer side faced the separator. Thereafter, a 1.0 M LiPF ₆ solution (solvent: ethylene carbonate / ethyl methyl carbonate = 3/7 (volume ratio), additive: vinylene carbonate 2 mass% (solvent ratio)) was filled as an electrolytic solution. Next, a lithium ion secondary battery as a non-aqueous secondary battery was manufactured by heat-sealing the aluminum packaging material at 150 ° C. and sealingly closing the opening of the aluminum packaging material.
And about the manufactured lithium ion secondary battery, the lithium deposition rate was evaluated by the above-mentioned method. Table 1 shows the results.

(Example 2)
In step (B), an aqueous solution containing a water-soluble polymer, an aqueous solution containing a neutralized water-soluble polymer, and a binder were prepared in the same manner as in Example 1 except that the opening of the filter cartridge to be installed was changed to 25 μm. A water-soluble polymer for use, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were produced.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 3)
In step (B), an aqueous solution containing a water-soluble polymer, an aqueous solution containing a neutralized water-soluble polymer, a binder, and the like were prepared in the same manner as in Example 1 except that the opening of the filter cartridge to be installed was changed to 75 μm. A water-soluble polymer for use, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were produced.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 4)
In the step of preparing the water-soluble polymer, an aqueous solution containing the water-soluble polymer was neutralized in the same manner as in Example 1 except that 0.06 part of isopropyl alcohol as a molecular weight modifier was newly added at the start of the reaction. An aqueous solution containing the water-soluble polymer, a water-soluble polymer for a binder, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were produced.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 5)
In the preparation step of the water-soluble polymer, an aqueous solution containing the water-soluble polymer was neutralized in the same manner as in Example 1 except that 0.56 part of isopropyl alcohol as a molecular weight modifier was newly added at the start of the reaction. An aqueous solution containing the water-soluble polymer, a water-soluble polymer for a binder, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were produced.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 6)
In the step of preparing the water-soluble polymer, a 2.5% aqueous solution of potassium persulfate as a polymerization initiator at the start of the polymerization reaction is changed to 4.4 parts, and polymerization is added 15 minutes after the start of the polymerization reaction. An aqueous solution containing a water-soluble polymer and a neutralized water-soluble polymer are contained in the same manner as in Example 1 except that the 2.0% aqueous solution of tetramethylethylenediamine as an agent is changed to 11.1 parts. An aqueous solution, a water-soluble polymer for a binder, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were produced.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 7)
In the step of preparing the water-soluble polymer, a 2.5% aqueous solution of potassium persulfate as a polymerization initiator at the start of the polymerization reaction is changed to 2.2 parts, and polymerization is added 15 minutes after the start of the polymerization reaction. An aqueous solution containing a water-soluble polymer and a neutralized water-soluble polymer are contained in the same manner as in Example 1 except that the 2.0% aqueous solution of tetramethylethylenediamine as an agent is changed to 5.6 parts. An aqueous solution, a water-soluble polymer for a binder, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were produced.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 8)
During the preparation of the slurry composition for the negative electrode, the binder composition was changed to 0.4 parts corresponding to the solid content, and the solid content concentration of the intermediate dilution mixture was changed to 54%. Further, the particulate polymer was changed to 1.6 parts in terms of solid content (that is, the content ratio of the binder water-soluble polymer was 20 mass% of the total content of the binder water-soluble polymer and the particulate polymer). %), An aqueous solution containing a water-soluble polymer, an aqueous solution containing a neutralized water-soluble polymer, and an aqueous solution for a binder in the same manner as in Example 1 except that the final solid content concentration of the mixture was changed to 50%. A polymer, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 9)
At the time of preparing the slurry composition for the negative electrode, the binder composition was changed to 0.2 parts corresponding to the solid content, and the solid content concentration of the intermediate dilution mixture was changed to 56%. In addition, the particulate polymer was changed to 1.8 parts in terms of solid content (that is, the content ratio of the binder water-soluble polymer was 10 mass% of the total content of the binder water-soluble polymer and the particulate polymer). %), An aqueous solution containing a water-soluble polymer, an aqueous solution containing a neutralized water-soluble polymer, and an aqueous solution for a binder in the same manner as in Example 1 except that the final solid content concentration of the mixture was changed to 52%. A polymer, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 10)
At the time of preparing the slurry composition for the negative electrode, the binder composition was changed to 1.6 parts corresponding to the solid content, and the solid content concentration of the intermediate dilution mixture was changed to 51%. In addition, the particulate polymer was changed to 0.4 parts in terms of solid content (that is, the content of the binder water-soluble polymer was 80 mass of the total content of the binder water-soluble polymer and the particulate polymer). %), An aqueous solution containing a water-soluble polymer, an aqueous solution containing a neutralized water-soluble polymer, and an aqueous solution for a binder in the same manner as in Example 1 except that the final solid concentration of the mixture was changed to 47%. A polymer, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 11)
At the time of preparing the slurry composition for the negative electrode, the binder composition was changed to 1.8 parts corresponding to the solid content, and the solid concentration of the intermediate dilution mixture was changed to 50%. In addition, the particulate polymer was changed to 0.2 parts in terms of solid content (that is, the content of the binder water-soluble polymer was 90 mass of the total content of the binder water-soluble polymer and the particulate polymer). %), An aqueous solution containing a water-soluble polymer, an aqueous solution containing a neutralized water-soluble polymer, and a water-soluble solution for a binder in the same manner as in Example 1 except that the final solid content of the mixture was changed to 46%. A polymer, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 12)
An aqueous solution containing a water-soluble polymer and a neutralized water-soluble polymer were prepared in the same manner as in Example 1 except that styrene was changed to 25 parts and 1,3-butadiene was changed to 72 parts during preparation of the particulate polymer. An aqueous solution containing a polymer, a water-soluble polymer for a binder, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 13)
An aqueous solution containing a water-soluble polymer and a neutralized water-soluble polymer were prepared in the same manner as in Example 1 except that styrene was changed to 35 parts and 1,3-butadiene was changed to 62 parts during preparation of the particulate polymer. An aqueous solution containing a polymer, a water-soluble polymer for a binder, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 14)
An aqueous solution containing a water-soluble polymer and a neutralized water-soluble polymer were prepared in the same manner as in Example 1 except that styrene was changed to 65 parts and 1,3-butadiene was changed to 32 parts during preparation of the particulate polymer. An aqueous solution containing a polymer, a water-soluble polymer for a binder, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 15)
An aqueous solution containing a water-soluble polymer and a neutralized water-soluble polymer were prepared in the same manner as in Example 1 except that styrene was changed to 70 parts and 1,3-butadiene was changed to 27 parts during preparation of the particulate polymer. An aqueous solution containing a polymer, a water-soluble polymer for a binder, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 16)
A water-soluble polymer was prepared in the same manner as in Example 1 except that styrene was changed to 50.5 parts, 1,3-butadiene was changed to 48 parts, and itaconic acid was changed to 1.5 parts during preparation of the particulate polymer. , An aqueous solution containing a neutralized water-soluble polymer, a water-soluble polymer for a binder, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Example 17)
During the preparation of the particulate polymer, an aqueous solution containing a water-soluble polymer was prepared in the same manner as in Example 1, except that styrene was changed to 48 parts, 1,3-butadiene was changed to 45 parts, and itaconic acid was changed to 7 parts. An aqueous solution containing the neutralized water-soluble polymer, a water-soluble polymer for a binder, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were manufactured.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Comparative Example 1)
In step (B), an aqueous solution containing a water-soluble polymer, an aqueous solution containing a neutralized water-soluble polymer, and a binder were prepared in the same manner as in Example 1 except that the size of the filter cartridge to be installed was changed to 110 μm. A water-soluble polymer for use, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were produced.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Comparative Example 2)
A water-soluble polymer was prepared in the same manner as in Example 1, except that the aqueous solution containing the neutralized water-soluble polymer obtained through the step (A) was used as a binder composition without filtering in the step (B). An aqueous solution containing a polymer, an aqueous solution containing a neutralized water-soluble polymer, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were produced.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Comparative Example 3)
In step (A), an aqueous solution containing a water-soluble polymer and an aqueous solution containing a neutralized water-soluble polymer were obtained in the same manner as in Example 1 except that the size of the filter cartridge to be installed was changed to 0.5 μm. , A water-soluble polymer for a binder, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery.
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

(Comparative Example 4)
The order of step (A) and step (B) was reversed. That is, after filtering the obtained aqueous solution containing the water-soluble polymer using a filter cartridge having an aperture of 2 μm, the aqueous solution containing the water-soluble polymer after the filtration is adjusted to pH 8 using a 5% aqueous solution of lithium hydroxide. To obtain a binder composition. An aqueous solution containing a water-soluble polymer, a binder composition, a particulate polymer, a slurry composition, an electrode, and a secondary battery were produced in the same manner as in Example 1, except that the binder composition was obtained in this order. .
Then, measurement and evaluation were performed in the same manner as in Example 1. Table 1 shows the results.

From Table 1, in the binder composition of Comparative Example 2 prepared without performing the filtration in the step (B), the particle diameter in the binder composition was 1 μm or more as compared with Examples 1 to 17 in which the step (B) was performed. Insoluble fraction increased to 8.0% by mass. As a result, the dispersion stability of the prepared slurry composition, the flexibility of the electrode, the adhesion of the electrode, the electrolyte injectability of the electrode, and the metal deposition rate of the secondary battery in Examples 1 to 17 Worse than.
Further, in the binder composition of Comparative Example 4 prepared by performing the filtration in the step (B) and then performing the neutralization in the step (A), Example 1 in which the step (B) was performed after the step (A). As compared with No. 17 to 17, the insoluble fraction of the binder composition having a particle diameter of 1 μm or more was greatly increased to 7.5% by mass. As a result, in the case of Examples 1 to 17 in all of the dispersion stability of the manufactured slurry composition, the flexibility of the electrode, the adhesion of the electrode, the electrolyte injection property of the electrode, and the metal deposition rate of the secondary battery Worse than.
Further, Comparative Example 1 in which the insoluble fraction having a particle diameter of 1 μm or more in the binder composition was adjusted to more than 5.0% by mass or less than 0.0001% by mass by adjusting the aperture of the filter cartridge in the step (B). Also in the binder compositions of Examples 1 and 3, the insoluble fraction was 0.0001% by mass or more and 5.0% by mass or less as compared with Examples 1 to 17, and the dispersion stability of the prepared slurry composition and the electrode Of the electrode, electrolyte injection property of the electrode, and metal deposition rate of the secondary battery were deteriorated.

Advantageous Effects of Invention According to the present invention, a non-aqueous system capable of producing a binder composition capable of simultaneously maintaining good adhesion of an electrode while maintaining good adhesion of an electrode during battery assembly and suppressing metal deposition during charging can be manufactured. A method for producing a binder composition for a secondary battery electrode can be provided.
Further, according to the present invention, a method of manufacturing an electrode for a non-aqueous secondary battery capable of manufacturing an electrode capable of having the good electrolyte injection property while maintaining the high adhesion, and a method of manufacturing the electrode. A method for producing a slurry composition for a non-aqueous secondary battery electrode capable of producing a slurry composition used in the production can be provided.
Further, according to the present invention, it is possible to provide a method of manufacturing a non-aqueous secondary battery capable of manufacturing a secondary battery capable of suppressing metal deposition on an electrode during charging.

Claims (7)

A method for producing a binder composition for a non-aqueous secondary battery electrode comprising a water-soluble polymer for a binder containing a (meth) acrylamide monomer unit,
Neutralizing an aqueous solution containing a water-soluble polymer (A);
A binder composition for a non-aqueous secondary battery electrode containing the water-soluble polymer for a binder, by filtering an aqueous solution containing the neutralized water-soluble polymer using a filtering material having an opening of 1 μm or more and 30 μm or less . And (B) obtaining
The insoluble fraction having a particle diameter of 1 μm or more with respect to the total solid content in the binder composition for a non-aqueous secondary battery electrode is 0.0001% by mass or more and 5.0% by mass or less.
A method for producing a binder composition for a non-aqueous secondary battery electrode. After the step (B), the weight-average molecular weight of the water-soluble polymer for a binder is 0.1 × 10 ⁶ or more and 20 × 10 ⁶ or less;
A method for producing the binder composition for a non-aqueous secondary battery electrode according to claim 1. A method for producing a slurry composition for a non-aqueous secondary battery electrode comprising an electrode active material and a binder composition for a non-aqueous secondary battery electrode,
A step of preparing the binder composition for a non-aqueous secondary battery electrode according to the method for producing a binder composition for a non-aqueous secondary battery electrode according to claim 1 or 2 .
A method for producing a slurry composition for a non-aqueous secondary battery electrode. The non-aqueous secondary battery electrode slurry composition,
10 to 70% by mass of an aromatic vinyl monomer unit, 20 to 80% by mass of an aliphatic diene monomer unit, and 1% by mass or more of an ethylenically unsaturated carboxylic acid monomer unit. Further containing a particulate polymer containing 10% by mass or less,
A method for producing the slurry composition for a non-aqueous secondary battery electrode according to claim 3 . The content ratio of the water-soluble polymer for binder is 10% by mass or more and 90% by mass or less based on the total content of the water-soluble polymer for binder and the particulate polymer.
A method for producing the slurry composition for a non-aqueous secondary battery electrode according to claim 4 . A method for producing an electrode for a non-aqueous secondary battery including forming an electrode mixture layer on a current collector,
The electrode mixture layer is formed using a slurry composition for a non-aqueous secondary battery electrode prepared according to the method for producing a slurry composition for a non-aqueous secondary battery electrode according to any one of claims 3 to 5. Including steps,
A method for producing an electrode for a non-aqueous secondary battery. A method for producing a non-aqueous secondary battery comprising a positive electrode, a negative electrode, and an electrolytic solution,
A step of producing at least one of the positive electrode and the negative electrode according to the method for producing an electrode for a non-aqueous secondary battery according to claim 6 ,
A method for manufacturing a non-aqueous secondary battery.