JPWO2018105338A1 - Binder composition for power storage element, slurry composition for power storage element, electrode, electrode manufacturing method, secondary battery, and electric double layer capacitor - Google Patents

Abstract

An object of the present invention is to provide a binder composition for an electricity storage device that achieves both a low temperature heat treatment of an electrode and a high capacity retention rate. The present invention is a binder composition for an electricity storage element containing a nitrogen-containing aromatic resin, a thermal crosslinking agent having an alkoxymethyl group and / or a methylol group. [Selection figure] None

Description

  The present invention relates to a binder composition for an electricity storage device. More specifically, the present invention relates to a binder composition for a storage element that can be preferably applied to a high-capacity, high-output storage element.

  Lithium-ion batteries are rechargeable high-capacity batteries that enable electronic devices to function and operate for a long time. Furthermore, it is mounted on automobiles and is regarded as a promising battery for hybrid and electric vehicles. Currently, lithium ion batteries widely used include a positive electrode formed by applying a paste slurry containing an active material such as lithium cobaltate and a binder such as polyvinylidene fluoride (PVDF) on an aluminum foil, and a carbon-based active battery. It has a negative electrode formed by applying a paste slurry containing a substance and a binder such as PVDF or styrene-butadiene rubber (SBR) on a copper foil.

  In order to further increase the capacity of a lithium ion battery, it has been studied to use a high-capacity negative electrode active material such as silicon, germanium, or tin as the negative electrode active material (see, for example, Patent Document 1). Since these high-capacity negative electrode active materials can receive a large amount of lithium ions, the volume changes greatly when fully charged and fully discharged, such as PVDF and SBR. Binders cannot follow the volume change of the active material, and studies have been made to use a polyimide resin, which is a nitrogen-containing aromatic resin having more excellent mechanical properties, as a binder for the negative electrode (see, for example, Patent Document 2). Since the polyimide resin has low solvent solubility, it is usually used after being heat-treated in a precursor polyamic acid dissolved in an organic solvent such as N-methylpyrrolidone or N, N′-dimethylacetamide. However, even when an active material such as silicon, germanium, or tin is used as the binder, a high-temperature heat treatment of 250 ° C. or higher is required in order to exhibit sufficient binding properties, so conventional PVDF and SBR binders are used. However, there was a problem that the existing equipment could not cope.

  For this reason, examination which applies the polyamide imide resin and polyamide resin which are nitrogen-containing aromatic resins similarly as a binder is performed (for example, refer patent document 3, 4).

JP 2009-199761 A JP 2012-109142 A JP 2011-48969 A Japanese Patent Application Laid-Open No. 10-302772

  However, polyamideimide resin and polyamide resin have to introduce a functional group with high flexibility and a functional group that easily solvates with a polar solvent in order to impart solvent solubility. And the degree of dissolution is large. Furthermore, when a high proportion of cyclic carbonates such as ethylene carbonate and propylene carbonate are used in the electrolyte, nitrogen-containing polar solvents such as N-methylpyrrolidone, sulfur-containing polar solvents such as dimethyl sulfoxide, lactones such as GBL, etc. If it is contained, the binder resin is eluted in the electrolytic solution. As a result, there is a problem that the binding force of the binder resin is reduced and the capacity retention rate of the battery is reduced.

  An object of this invention is to provide the binder composition for electrical storage elements which exhibits a high capacity | capacitance maintenance factor, when a nitrogen-containing aromatic resin soluble in a solvent is used in view of the said subject.

  This invention is a binder composition for electrical storage elements containing the nitrogen-containing aromatic resin, the thermal crosslinking agent which has an alkoxymethyl group and / or a methylol group.

  This invention is the slurry composition for electrical storage elements containing the binder composition for electrical storage elements of this invention, and the substance which can occlude and discharge | release lithium ion.

  The present invention is an electrode having a layer in which the slurry composition for an electricity storage element of the present invention is formed on at least one surface of a support substrate or a thermal crosslinking reaction product thereof.

  This invention is a manufacturing method of an electrode including the process of apply | coating the slurry composition for electrical storage elements of this invention to the at least single side | surface of a support substrate, forming a coating film, and the process of drying the said coating film.

  The present invention is a secondary battery having the electrode of the present invention.

  The present invention is an electric double layer capacitor having the electrode of the present invention.

  According to the present invention, a binder composition for an electricity storage device that exhibits a high capacity retention rate even when a nitrogen-containing aromatic resin soluble in a solvent is used can be obtained.

  This invention is a binder composition for electrical storage elements containing the nitrogen-containing aromatic resin, the thermal crosslinking agent which has an alkoxymethyl group and / or a methylol group.

  By crosslinking the nitrogen-containing aromatic resin with a thermal crosslinking agent, the polymer chain takes a three-dimensional structure, so that it is appropriately swollen with the electrolytic solution and the mechanical strength is also improved, so that a high capacity retention rate can be achieved.

  The nitrogen-containing aromatic resin includes a resin containing an aromatic ring and a nitrogen atom in the main chain, and also includes a nitrogen-containing aromatic ring. For example, polyimide, polyamideimide, polyamide, benzoxazine resin, polyazomethine, polybenzo Examples thereof include oxazole, polybenzimidazole, polybenzothiazole, polyurea, and melamine resin.

  Among these, a nitrogen-containing aromatic resin having a repeating unit represented by the following general formula (1) and / or a repeating unit represented by the following general formula (2) has high mechanical strength as a single resin, This is preferable because volume expansion can be efficiently suppressed. In particular, the total content ratio of the repeating unit represented by the general formula (1) and the repeating unit represented by the following general formula (2) in the nitrogen-containing aromatic resin is 50 mol% or more. This is preferable because the capacity retention rate can be further increased.

(R ¹ represents a divalent organic group having 2 to 50 carbon atoms, and R ² represents a tetravalent aromatic organic group having 6 to 50 carbon atoms.)

(R ³ represents a divalent organic group having 2 to 50 carbon atoms, and R ⁴ represents a trivalent aromatic organic group having 6 to 50 carbon atoms.)
The resin represented by the general formula (1) and the general formula (2) can be produced by a known polymerization method. For example, various diamines or isocyanates alone or a mixture of a plurality of them can be used. It can be obtained by polycondensation of a tetracarboxylic acid or tricarboxylic acid derivative.

When either or both of R ¹ in the general formula (1) and R ³ in the general formula (2) use a diamine having a phenolic hydroxyl group and / or a carboxyl group in the structure, the crosslinking density may be increased. It is preferable because swelling and elution into the electrolyte can be effectively suppressed. Examples of the diamine having a phenolic hydroxyl group include 2,2-bis (4-amino-3-hydroxyphenyl) propane, 2,2-bis (3-amino-4-hydroxyphenyl) propane, and 2,2-bis (4 -Amino-3-hydroxyphenyl) hexafluoropropane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 3,3'-dihydroxybenzidine, bis (3-amino-4-hydroxyphenyl) Sulfone, bis (3-amino-4-hydroxyphenyl) ether, 9,9-bis (3-amino-4-hydroxyphenyl) fluorene, 1,5-diamino-4,8-dihydroxyanthraquinone, etc. It is not limited to these. Examples of the diamine having a carboxyl group include, but are not limited to, 3,5-diaminobenzoic acid, 3,4-diaminobenzoic acid, and 5,5′-methylenebis (2-aminobenzoic acid). Each of these may be used alone or in combination.

In the nitrogen-containing aromatic resin, when the total of R ¹ in the general formula (1) and R ³ in the general formula (2) is 100 mol%, the structure represented by the following general formula (3) is 20 By containing at least mol%, preferably at least 50 mol%, the strength of the resin alone can be further increased.

(R ⁵ represents a hydroxy group, a mercapto group, or an organic group having 1 to 6 carbon atoms. P represents an integer of 0 to 4. R ⁵ may be the same or different.)
Examples of the diamine or diisocyanate giving the structure represented by the general formula (3) include 2,2-bis (trifluoromethyl) benzidine, 3,3′-dihydroxybenzidine, 3,3 ′, 5,5′-tetra. Examples include, but are not limited to, methylbenzidine, o-tolidine, m-tolidine, 4,4′-diisocyanato-3,3′-dimethylbiphenyl, and the like. These may be used alone or in combination of two or more.

In the nitrogen-containing aromatic resin, when the total of R ¹ in the general formula (1) and R ³ in the general formula (2) is 100 mol%, the structure represented by the following general formula (4) is 20 By including the mol% or more, preferably 50 mol% or more, the adhesion of the electrode paste to the substrate can be enhanced.

(R ⁶ represents a hydroxy group, a mercapto group, or an organic group having 1 to 6 carbon atoms, X represents any one of a carbonyl group, a methylene group, an isopropyl group, an isopropyl hexafluoride group, and an ether bond. Represents an integer of 4. R ⁶ may be the same or different.
Examples of the diamine or diisocyanate that gives the structure represented by the general formula (4) include 4,4′-diaminobenzophenone, 3,3′-diaminobenzophenone, 4,4′-diaminodiphenylmethane, and 3,3′-diamino. Diphenylmethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 3,3′-diamino-4,4′-dimethyldiphenylmethane, 4,4′-methylenebis (2-ethyl-6-methylaniline), 4 , 4′-methylenebis (2,6-dimethylaniline), 4,4′-methylenebis (2,6-diethylaniline), 2,2-bis (4-aminophenyl) propane, 2,2-bis (3- Amino-4-hydroxyphenyl) propane, 2,2-bis (3-amino-4-methylphenyl) propane, 2,2-bis (4-amino) Phenyl) hexafluoropropane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 2,2-bis (3-amino-4-methylphenyl) hexafluoropropane, 4,4′-diamino Examples include, but are not limited to, diphenyl ether, 3,3′-diaminodiphenyl ether, bis (4-isocyanatophenyl) methane, bis (3-isocyanatophenyl) methane, and the like. One of these may be used, or a plurality of these may be used.

  Examples of tetracarboxylic acids include pyromellitic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 2,2 ′, 3,3 '-Biphenyltetracarboxylic acid, 3,3', 4,4'-benzophenonetetracarboxylic acid, 2,2 ', 3,3'-benzophenonetetracarboxylic acid, 2,2-bis (3,4-dicarboxyphenyl) ) Hexafluoropropane, 2,2-bis (2,3-dicarboxyphenyl) hexafluoropropane, 1,1-bis (3,4-dicarboxyphenyl) ethane, 1,1-bis (2,3-di Carboxyphenyl) ethane, bis (3,4-dicarboxyphenyl) methane, bis (2,3-dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) sulfone Bis (3,4-dicarboxyphenyl) ether, 1,2,5,6-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 2,3,5,6-pyridinetetracarboxylic acid Aromatic tetracarboxylic acid such as 3,4,9,10-perylenetetracarboxylic acid, cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, cyclohexanetetracarboxylic acid, bicyclo [2. 2.1. ] Heptanetetracarboxylic acid, bicyclo [3.3.1. ] Tetracarboxylic acid, bicyclo [3.1.1. ] Hept-2-enetetracarboxylic acid, bicyclo [2.2.2. Examples thereof include aliphatic tetracarboxylic acids such as octanetetracarboxylic acid and adamantanetetracarboxylic acid, but are not limited thereto.

  Examples of tricarboxylic acids include trimellitic acid, 3,3 ′, 4-tricarboxybiphenyl, 3,4,4′-tricarboxybiphenyl, 3,3 ′, 4-tricarboxybiphenyl ether, 3,4,4 And '-tricarboxybiphenyl ether.

  Each of the tricarboxylic acid and tetracarboxylic acid may be used alone or in combination.

  When synthesizing a nitrogen-containing aromatic resin, the degree of polymerization of the polymer to be produced increases as the charge ratio (molar ratio) of diamine to tricarboxylic acid or tetracarboxylic acid is close to 1: 1, as in a normal polycondensation reaction. Increases and the weight average molecular weight increases. In the present invention, the weight average molecular weight is preferably 10,000 or more and 150,000 or less. By setting the weight average molecular weight to 10,000 or more in terms of polystyrene by GPC (gel permeation chromatography), sufficient binding properties as a binder can be provided. On the other hand, by setting the weight average molecular weight to 150,000 or less, high solubility in a solvent can be maintained. In order to obtain a polymer having the above weight average molecular weight, it is preferable that the charging ratio (molar ratio) of diamine and dicarboxylic acid is 100: 50 to 150.

  The solvent used in the polycondensation reaction is not particularly limited as long as the produced resin can be dissolved, but N-methyl-2-pyrrolidone, N-methylcaprolactam, N, N-dimethylacetamide, Aprotic polar solvents such as N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, dimethylimidazoline, phenolic solvents such as phenol, m-cresol, chlorophenol, nitrophenol, polyphosphoric acid, phosphoric pentoxide A phosphorus solvent to which is added can be preferably used.

  Generally, a polymer is obtained by reacting acid chloride or active ester of tricarboxylic anhydride, tetracarboxylic dianhydride and diamine in these solvents. In order to generate an imide structure by a ring-closing reaction, stirring is performed while distilling off by-product water at a temperature of 150 to 220 ° C., or stirring is performed by adding a tertiary amine as a dehydrating agent such as an acid anhydride and a catalyst. Let When a dehydrating agent and a catalyst are used, the polymer can be obtained as a solid by adding it to water or the like to precipitate a resin and drying it.

  Alternatively, the polymer can be similarly obtained by reacting diisocyanate with tricarboxylic anhydride or diisocyanate with tetracarboxylic dianhydride.

  The thermal crosslinking agent having an alkoxymethyl group and / or a methylol group used in the present invention preferably has two or more as the total number of alkoxymethyl groups and methylol groups in one molecule. From the viewpoint of compatibility with the nitrogen-containing aromatic resin, the thermal crosslinking agent having an alkoxymethyl group and / or a methylol group is preferably not a polymer but a low molecular compound. The binder composition for an electricity storage element of the present invention may contain one kind of thermal crosslinking agent or may contain two or more kinds.

  Specific examples include, for example, DML-PC, DML-PEP, DML-OC, DML-OEP, DML-34X, DML-PTBP, DML-PCHP, DML-OCHP, DML-PFP, DML-PSBP, DML-POP. , DML-MBOC, DML-MBPC, DML-MTrisPC, DML-BisOC-Z, DML-BisOCHP-Z, DML-BPC, DML-BisOC-P, DMOM-PC, DMOM-PTBP, DMOM-MBPC, TriML-P , TriML-35XL, TML-HQ, TML-BP, TML-pp-BPF, TML-BPE, TML-BPA, TML-BPAF, TML-BPAP, TMOM-BP, TMOM-BPE, TMOM-BPA, TMOM-BPAF , TMOM-BPAP, HML TPPHBA, HML-TPHAP, HMOM-TPPHBA, HMOM-TPHAP (trade name, manufactured by Honshu Chemical Industry Co., Ltd.), or their lithium, sodium, potassium ion compound. "NIKALAC" (registered trademark) MX-290, NIKACALAC MX-280, NIKACALAC MX-270, NIKACALAC MX-279, NIKACAL MW-100LM, NIKACALAC MX-750LM It is done. Two or more of these may be contained.

  Among them, when a thermal crosslinking agent having a cyclic structure such as an aromatic ring or an aliphatic ring in the molecule is used, the strength of the electrode after crosslinking is increased and the mechanical strength is improved, so that a high capacity retention rate can be achieved. Specific examples of such thermal crosslinking agents include DML-PC, DML-PEP, DML-OC, DML-OEP, DML-34X, DML-PTBP, DML-PCHP, DML-OCHP, DML-PFP, DML- PSBP, DML-POP, DML-MBOC, DML-MBPC, DML-MTrisPC, DML-BisOC-Z, DML-BisOCHP-Z, DML-BPC, DML-BisOC-P, DMOM-PC, DMOM-PTBP, DMOM- MBPC, TriML-P, TriML-35XL, TML-HQ, TML-BP, TML-pp-BPF, TML-BPE, TML-BPA, TML-BPAF, TML-BPAP, TMOM-BP, TMOM-BPE, TMOM- BPA, TMOM-BPAF, TMOM-BP P, HML-TPPHBA, HML-TPHAP, HMOM-TPPHBA, HMOM-TPHAP or their lithium, sodium, potassium ion compound. “NIKALAC” (registered trademark) MX-290, NIKACALAC MX-280, NIKACALAC MX-270, NIKACALAC MX-279, NIKACALAC MW-100LM, NIKACALAC MX-750LM, and the like. Two or more of these may be used.

  A thermal crosslinking agent having a total of 4 or more alkoxymethyl groups and methylol groups in the thermal crosslinking agent having an alkoxymethyl group and / or a methylol group has a high crosslinking density, and thus has a high crosslinking density. It is preferable because an electrode that swells moderately can be produced. Specific examples of such a thermal crosslinking agent include HMOM-TPHAP, MX-270, and MW-100LM.

  About content of the thermal crosslinking agent contained in the binder composition for electrical storage elements of this invention, when raising a crosslinking density, Preferably it is 0.5 with respect to 100 mass parts of nitrogen-containing aromatic resin contained in this composition. It is 3 parts by mass or more, more preferably 3 parts by mass or more. Moreover, 50 mass parts or less are preferable from a viewpoint of improving the softness | flexibility of an electrode, and 30 mass parts or less are more preferable.

  Furthermore, a photoacid generator or a thermal acid generator may be added in order to promote crosslinking of the thermal crosslinking agent having an alkoxymethyl group and / or a methylol group.

  The thermal acid generator that can be preferably contained in the binder composition for an electricity storage device of the present invention preferably has a thermal decomposition starting temperature of 50 ° C to 270 ° C, more preferably 50 ° C to 150 ° C.

  Furthermore, as required, the binder composition for an electricity storage device of the present invention is a surfactant, a silane coupling agent such as aminopropyltrimethoxysilane, trimethoxyvinylsilane, or trimethoxyglycidoxysilane, a triazine compound, a phenanthroline compound. The triazole compound may be contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the total resin. By containing these, adhesiveness with an active material and metal foil can further be improved.

  The nitrogen-containing aromatic resin and the thermal crosslinking agent can be used as a binder composition for an electricity storage element by dissolving or dispersing in an arbitrary solvent.

  The range of the concentration and the viscosity when dissolved or dispersed in the solvent of the binder composition for an electricity storage device of the present invention is preferably a concentration of 1 to 50% by mass and a viscosity of 1 mPa · second to 1000 Pa · second, more preferably a concentration. The viscosity is 5 to 30% by mass and the viscosity is 100 mPa · second to 100 Pa · second.

  Specific examples of the solvent suitably used in the binder composition for an electricity storage device of the present invention include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ale, propylene glycol monoethyl ether, ethylene glycol dimethyl ether, and ethylene glycol. Ethers such as diethyl ether, ethylene glycol dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propyl acetate, butyl acetate, isobutyl acetate, 3-methoxybutyl Acetate, 3-me Acetates such as ru-3-methoxybutyl acetate, methyl lactate, ethyl lactate, butyl lactate, ketones such as acetylacetone, methylpropylketone, methylbutylketone, methylisobutylketone, cyclopentanone, 2-heptanone, butyl alcohol, Isobutyl alcohol, pentaanol, 4-methyl-2-pentanol, 3-methyl-2-butanol, 3-methyl-3-methoxybutanol, alcohols such as diacetone alcohol, aromatic hydrocarbons such as toluene and xylene N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, water and the like. These can be used alone or in combination.

  The binder composition for an electricity storage device of the present invention can be made into a slurry composition for an electricity storage device further containing a functional organic or inorganic material. In particular, these compounds play a role as active materials by containing substances capable of inserting and extracting lithium ions.

  A substance that occludes and releases lithium ions is a substance that can insert and desorb lithium ions in the crystal structure of the substance, a substance that can desorb and reinsert lithium in the crystal structure of the substance as lithium ions, and lithium ions Indicates a material that can be alloyed and dealloyed. Examples of such a substance include substances containing atoms such as carbon, silicon, tin, germanium, titanium, iron, cobalt, nickel, manganese, copper, silver, zinc, indium, bismuth, antimony, or chromium. Specifically, lithium iron phosphate, lithium cobaltate, lithium nickelate, lithium manganate, activated carbon, carbon nanotube, graphite, lithium titanate, hard carbon, soft carbon, activated carbon, silicon, silicon oxide, silicon carbide, etc. Can be mentioned. You may use the substance which mixed and / or compounded 2 or more types from these. Furthermore, the surface of the particles of the substance may be treated with a surface modifier such as a coating or a silane coupling agent. In particular, when the conductivity of a substance to be used is low, the electrical resistance of the electrode can be lowered by performing carbon coating, that is, covering the surface of the substance with carbon.

  In particular, by including at least one of the following (a1) to (a7), it is possible to obtain a power storage element having excellent capacity and / or rate characteristics.

(A1) Silicon (excluding cases corresponding to (a4))
(A2) Lithium titanate (a3) Silicon oxycarbide (a4) Substance in which silicon and silicon oxide are mixed or combined (a5) Substance in which two or more of (a1) to (a4) are mixed or combined (However, except when (a1) and (a4) are mixed)
(A6) A substance in which one or more of (a1) to (a4) and carbon are mixed or combined (a7) A substance of (a1) to (a5) whose surface is carbon-coated Silicon is unit volume and unit Since there is much quantity which can occlude the lithium ion per mass, when it uses as a slurry composition for electrical storage elements, a high capacity | capacitance battery can be obtained. On the other hand, since the volume expansion at the time of occlusion of lithium ions is large, the capacity retention rate is likely to decrease. By using the binder resin composition for an electricity storage device of the present invention, an electrode having a high capacity and a high capacity retention rate can be obtained.

  Although lithium titanate is excellent in rate characteristics, a battery driven at a high output has a large calorific value, and therefore can be preferably used for the binder resin composition for an electricity storage device of the present invention having high binding properties at high temperatures.

  Since silicon oxycarbide has a structure in which silicon, oxygen, and carbon are uniformly distributed in the substance, the volume expansion of silicon is moderately suppressed, and it is possible to achieve both high capacity and high capacity retention. .

  A substance in which silicon and silicon oxide are combined has a structure in which silicon and silicon oxide are finely mixed in substance particles. In particular, in the case of a structure in which silicon is dispersed in silicon oxide, the volume expansion of silicon is moderately suppressed, and both a high capacity and a high capacity retention ratio can be achieved. Such a substance can be obtained by milling silicon and silicon oxide with a ball mill, a vibration mill, a planetary ball mill or the like. In another case, commercially available silicon monoxide (SiO) may be used.

  By using two or more of the substances (a1) to (a4) in a mixed or complexed manner, an electrode having the advantages of the respective materials can be obtained. The method for mixing and compounding is not particularly limited, but for example, it can be produced by milling two or more materials using a ball mill, a vibration mill, a planetary ball mill, or the like. It can also be obtained by mixing a precursor solution of silicon oxycarbide or lithium titanate with other materials, pulverizing and classifying the fired product.

  Further, by using one or more of (a1) to (a4) with a carbon material such as graphite, hard carbon, or soft carbon and using them in combination, an electrode with low electric resistance can be obtained. Although the method of mixing and compounding is not particularly limited, for example, it can be obtained by milling one or more of (a1) to (a4) and a carbon material with a ball mill, a vibration mill, a planetary ball mill, or the like. When the carbon material is graphite, it can be obtained by mixing with a small amount of carbon precursor such as various resins, polyimide precursors, tar or pitch, and firing and pulverizing.

  The electrical resistance of the electrode can also be lowered by carbon coating the surfaces of (a1) to (a5). The carbon coating method is not particularly limited, and vacuum deposition, ion plating, sputtering, chemical vapor deposition (CVD), and the like can be used.

  From the standpoint of achieving both high battery capacity and a high capacity retention ratio, a substance in which silicon and carbon are mixed or combined, a substance in which silicon and silicon oxide are mixed or combined, and silicon, silicon oxide and carbon It is particularly preferable to use a substance in which is mixed or complexed.

  Furthermore, from the viewpoint of achieving both a high capacity and a high capacity retention rate, silicon contained in a substance capable of occluding and releasing lithium ions when the mass of the whole substance capable of occluding and releasing lithium ions is 100% by mass. The content of is preferably 5 to 70% by mass, and more preferably 10 to 50% by mass.

  In the slurry composition for an electricity storage device of the present invention, the total content of the binder composition for an electricity storage device excluding the solvent is 1 part by mass or more in terms of solid content with respect to 100 parts by mass of the substance capable of occluding and releasing lithium ions. It is preferable, and adhesiveness can be improved more by setting it as more than the lower limit which concerns. 3 parts by mass or more is more preferable, 5 parts by mass or more is more preferable, and 20 parts by mass or less is preferable, and 15 parts by mass or less is more preferable in terms of reducing electric resistance and maintaining capacity and output. More preferred are:

  In order to reduce the electrical resistance of the secondary battery electrode and capacitor electrode, the slurry composition for an electricity storage device of the present invention is made of a conductive material such as graphite, ketjen black, carbon nanotube, acetylene black, metal such as silver or copper. It is preferable to contain a sex substance. The content of the conductive substance is preferably 0.1 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the substance capable of inserting and extracting lithium ions.

  The binder composition for an electricity storage device and the slurry composition for an electricity storage device of the present invention are capable of inserting and extracting a nitrogen-containing aromatic resin, a thermal cross-linking agent having an alkoxymethyl group and / or a methylol group, and, if necessary, lithium ions. It can be obtained by mixing and kneading the substance, conductive substance particles, solvent and other additives. In the case of mixing, put in a glass flask or stainless steel container, etc., a method of stirring and dissolving with a mechanical stirrer, etc., a method of dissolving with ultrasonic waves, a method of stirring and dissolving with a planetary stirring deaerator, etc. In the case of kneading, a method using a planetary mixer, three rolls, a ball mill, a homogenizer and the like can be mentioned. The mixing / kneading conditions are not particularly limited.

  Moreover, in order to remove foreign substances, the binder composition for power storage elements and the slurry composition for power storage elements after mixing and kneading may be filtered through a filter having a pore size of 0.01 μm to 100 μm. Examples of the material for the filter include polypropylene (PP), polyethylene (PE), nylon (NY), polytetrafluoroethylene (PTFE), and polyethylene and nylon are preferable. Moreover, when it contains the substance which can occlude and discharge | release lithium ion, and an electroconductive substance, it is preferable to filter before adding these, or to use the filter with a larger pore diameter than these particle diameters.

  An electrode for an electricity storage device can be produced by applying the binder composition for an electricity storage device containing a substance capable of occluding and releasing lithium ions to one side or both sides of a base material and drying it.

  As the base material, a conductive base material or an insulating base material having conductive wiring is used.

  Preferred examples of the conductive substrate include, but are not limited to, copper, aluminum, stainless steel, nickel, gold, silver, alloys thereof, and carbon. In particular, copper, aluminum, stainless steel, nickel and alloys containing them are more preferable.

  As an insulating base material having conductive wiring, wiring using the metal used for the conductive base material or an alloy containing them is polyimide, polyamideimide, polyamide, polyester, acrylic resin, epoxy resin, phenol resin. Examples thereof include, but are not limited to, those formed on a silicone resin substrate.

  Next, an example is given and demonstrated about the manufacturing method of the electrode of this invention.

  First, the slurry composition for an electricity storage device of the present invention is applied on a substrate with a thickness of 1 to 500 μm. As a base material, a copper foil is generally used when used for a lithium ion battery negative electrode (hereinafter may be abbreviated as “negative electrode”), and a lithium ion battery positive electrode (hereinafter abbreviated as “positive electrode”). In addition, when used for positive and negative electrodes of an electric double layer capacitor, aluminum foil, nickel foil, titanium foil, copper foil and the like can be mentioned, and aluminum foil is generally used. For the application, methods such as screen printing, roll coating, and slit coating can be used.

  After coating, the solvent is removed and heat treatment is performed at 100 ° C. to 250 ° C. for 10 minutes to 24 hours in order to perform a crosslinking reaction of the binder resin composition. In order to suppress the mixing of moisture, it is preferable to heat in an inert gas such as nitrogen gas or in a vacuum.

  Next, a lithium ion battery and an electric double layer capacitor using the electrode of the present invention will be described.

  About the electrode of this invention, what was laminated | stacked via the separator is put in exterior materials, such as a metal case, with electrolyte solution, A secondary battery and an electric double layer capacitor can be obtained.

  Examples of the separator include polyolefins such as polyethylene and polypropylene, microporous films such as cellulose, polyphenylene sulfide, aramid, and polyimide, and nonwoven fabrics.

  In order to increase the heat resistance, the surface of the separator may be coated. The coating liquid containing an inorganic filler and a binder is preferable.

  Examples of inorganic fillers include alumina, boehmite, calcium carbonate, calcium phosphate, amorphous silica, crystalline glass filler, kaolin, talc, titanium dioxide, silica-alumina composite oxide particles, calcium fluoride, lithium fluoride, zeolite , Molybdenum sulfide, mica and the like. Two or more of these may be included. Examples of the binder include an acrylic resin, a phenol resin, and carboxymethyl cellulose. You may use the binder composition for electrical storage elements of this invention.

  The solvent used for the electrolytic solution serves as a medium through which ions involved in the electrochemical reaction of the battery can move. Preferred solvents include carbonate-based, lactone-based, ether-based and aprotic solvents. Examples of the carbonate solvent include chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate, and cyclic carbonates such as ethylene carbonate, propylene carbonate, and butylene carbonate. Examples of the lactone solvent include γ-butyrolactone and valerolactone. Examples of the ether solvent include 1,3-dioxolane, 1,4-dioxane, tetrahydrofuran, 2-methyltetrahydrofuran, diethyl ether, 1,2-dimethoxyethane, ethoxymethoxyethane, 1,2-diethoxyethane, and the like. be able to. Examples of the aprotic solvent include nitrogen-containing polar solvents such as N-methylpyrrolidone and 1,3-dimethylimidazolidinone, and sulfur-containing polar solvents such as dimethyl sulfoxide and sulfolane.

  Two or more of these solvents may be used, and the content ratio can be appropriately selected according to the performance of the intended battery. For example, in the case of the carbonate-based solvent, it is preferable to use a combination of a cyclic carbonate and a chain carbonate in a volume ratio of 1: 1 to 1: 9, and the performance of the electrolytic solution can be improved.

  Furthermore, by mixing a lactone, a nitrogen-containing polar solvent and / or a sulfur-containing polar solvent, the solubility of the electrolyte and the boiling point as the electrolytic solution are increased, and a battery that can be used even at high temperatures can be obtained. The mixing ratio of these solvents is preferably 0.05% by mass or more of the total electrolyte mass from the viewpoint of solubility and boiling point as the total amount. 1% or more is more preferable, and 5% or more is more preferable.

  Examples of the electrolyte used for the electrolyte include lithium salts such as lithium hexafluorophosphate, lithium borofluoride, and lithium perchlorate, and ammonium salts such as tetraethylammonium tetrafluoroborate and triethylmethylammonium tetrafluoroborate.

  In order to describe the present invention in more detail, examples will be described below, but the present invention should not be construed as being limited to these examples. In addition, evaluation of the binder composition for electrical storage elements in an Example was performed with the following method.

(1) Electrolytic solution elution resistance evaluation (thickness reduction)
A binder composition for a storage element is applied onto a 4-inch silicon wafer using a spinner (Mikasa Co., Ltd.) and dried on a hot plate set at 120 ° C. for 3 minutes to provide a thin film having a thickness of 8 to 10 μm. A wafer was produced. The thickness of the thin film was measured with a film thickness measuring device (Lambda Ace ST-M602J, manufactured by Dainippon Screen Mfg. Co., Ltd.). The wafer with thin film obtained was heated at 50 ° C. for 30 minutes while flowing nitrogen at an inert oven (INH-9, manufactured by Koyo Thermo System Co., Ltd.) so that the oxygen concentration was 20 ppm or less, and then at a rate of 3.5 ° C. per minute. The temperature was raised to 150 ° C. and heat treatment was performed at 150 ° C. for 1 hour. The obtained wafer with a thin film was immersed in a solvent in which ethylene carbonate and dimethyl carbonate were mixed at a volume ratio of 1: 1, and left in a constant temperature bath (manufactured by Espec Corp., SU-222) for 24 hours. did. After removing the solvent on the surface of the wafer with the thin film after immersion by air blowing, the film thickness was measured again, and the amount of decrease in the film thickness was calculated according to the following formula.
Film thickness reduction (%) = (film thickness after immersion / film thickness before immersion) × 100.

(2) Evaluation of mechanical strength (stress at break)
The binder composition for an electricity storage element was applied onto a 6-inch silicon wafer using a spinner (Mikasa Co., Ltd.) and dried on a hot plate set at 120 ° C. for 3 minutes to form a 10 μm-thick wafer with a thin film. Produced. The thickness of the thin film was measured with a film thickness measuring device (Lambda Ace ST-M602J, manufactured by Dainippon Screen Mfg. Co., Ltd.). The obtained wafer with a thin film was heated at 50 ° C. for 30 minutes while flowing nitrogen at an inert oven (INH-9, manufactured by Koyo Thermo Systems Co., Ltd.) so that the oxygen concentration was 20 ppm or less, and then at a rate of 3.5 ° C. per minute. The temperature was raised to 150 ° C. and heat treatment was performed at 150 ° C. for 1 hour. The heat-treated thin film was cut with a single blade, immersed in an aqueous hydrofluoric acid solution, peeled off from the wafer, and dried in a ventilated oven at 50 ° C. for 24 hours to obtain a film of a binder composition for a storage element. The isolated membrane is cut into a strip shape with a width of 1 cm and a length of 7 to 10 cm, and a tensile test is performed at a test speed of 55 mm / min using a Tensilon universal tester (Orientec Co., Ltd., RTM-100). The breaking point stress (Mpa) of the film was measured.

(3) Evaluation of adhesion (peeling number) A substrate (copper sputter substrate) having a metal material layer on the surface of which a copper layer was formed with a thickness of 200 nm on a silicon wafer by sputtering was prepared. A binder composition for an electricity storage element was applied onto this substrate using a spinner (manufactured by Mikasa Co., Ltd.) and dried on a hot plate set at 120 ° C. for 3 minutes to prepare a wafer with a thin film having a thickness of 10 μm. The thickness of the thin film was measured with a film thickness measuring device (Lambda Ace ST-M602J, manufactured by Dainippon Screen Mfg. Co., Ltd.). The obtained wafer with a thin film was heated at 50 ° C. for 30 minutes while flowing nitrogen at an inert oven (INH-9, manufactured by Koyo Thermo Systems Co., Ltd.) so that the oxygen concentration was 20 ppm or less, and then at a rate of 3.5 ° C. per minute. The temperature was raised to 150 ° C. and heat treatment was performed at 150 ° C. for 1 hour. A single-edged blade was used for the film after curing, and 10 rows and 10 columns of grid-like cuts were made at intervals of 2 mm. Of these, one sample substrate was used to count how many of the 100 cells were peeled by peeling with cello tape (registered trademark), and the adhesion between the metal material and the cured binder film for the electricity storage element was evaluated.

(4) Synthesis of carbon-coated SiO (C-coated SiO) active material SiO particles (particles composed of a composite material of silicon and silicon oxide, manufactured by Sigma-Aldrich LLC), methane: nitrogen = 1: The surface of the particles was coated with pyrolytic carbon under the conditions of a processing temperature of 1000 ° C. using 1 as a source gas. The active material particles thus obtained were observed with an SEM, and the average particle size was calculated from the obtained image using image analysis type particle size distribution measurement software (manufactured by Mountec Co., Ltd., Mac-VIEW). Moreover, the thickness of the coating layer formed on the surface of the SiO particles was measured with a transmission electron microscope. As a result, particles in which the surface of SiO particles having an average particle diameter of 25 μm was coated with a coating layer made of carbon having a thickness of 5 nm were obtained.

(5) Synthesis of lithium titanate / silicon composite particles (LTO / Si composite particles) 4.591 g (0.01 mol) of lithium titanate (manufactured by Sigma-Aldrich GK, trade name “Lithium titanate, spinel”) in 10 mL of ethanol After melting, 4.591 g of silicon particles (manufactured by Sigma Aldrich GK, trade name “Silicon nanopowder”, hereinafter sometimes referred to as Si) was added, and ultrasonic irradiation was performed for 1 hour. The obtained dispersion was spray-dried at an air volume of 0.7 dm ³ / min, a spray pressure of 0.1 MPa, an outlet temperature of 155 ° C., and an inlet temperature of about 80 ° C. Then, it baked at 750 degreeC in nitrogen atmosphere, and classified after the grinding | pulverization process, and obtained negative electrode material with an average particle diameter of 5 micrometers.

(6) Production of negative electrode The slurry composition for an electricity storage element was applied onto an electrolytic copper foil (Fukuda Metal Foil Powder Industry Co., Ltd.) using a doctor blade, and an inert oven (manufactured by Koyo Thermo System, INH-9) was used. The mixture was heated at 50 ° C. for 30 minutes while flowing nitrogen so that the oxygen concentration was 20 ppm or less, then heated to 150 ° C. at a rate of 3.5 ° C. per minute, and heat treated at 150 ° C. for 1 hour. Thereafter, the oven was taken out when the temperature in the oven became 80 ° C. or lower. The coated part of the obtained copper foil with paste was punched out into a circle having a diameter of 15.9 mm and vacuum-dried at 150 ° C. for 24 hours to produce a negative electrode.

(7) Electrode characteristic evaluation (1C discharge capacity, 5C / 1C discharge capacity ratio, capacity maintenance rate after 50 cycles)
The capacity of the electrode prepared according to the method described in (6) Preparation of negative electrode was evaluated by the following method.

  In measuring the charge / discharge characteristics, an HS cell (manufactured by Hosen Co., Ltd.) was used, and the lithium ion battery was assembled in a nitrogen atmosphere. The negative electrode produced in the cell was punched into a circular shape with a diameter of 16.1 mm, the separator porous film (made by Toray Industries, Inc.) was punched into a diameter of 24 mm, and the positive electrode was a 0.2 mm thick lithium foil Punched in a circular shape with a diameter of 15.9 mm (made by Honjo Metal Co., Ltd.) are stacked one after another, filled with 1 mL of LBG-00022 (manufactured by Kishida Chemical Co., Ltd.) as an electrolytic solution, sealed, A battery was obtained.

  The lithium ion battery produced as described above had an upper limit voltage of 4.2 V, a lower limit voltage of 2.7 V, and a charge / discharge rate (C rate) of 0.1 C in the first cycle, and 0 in the second and third cycles. .2C, 4th cycle was 0.5C, 5th cycle was 1C, 6th cycle was 5C, and the charge capacity and discharge capacity were measured 6 times in total. The discharge capacities at the 5th and 6th cycles at this time were 1C discharge capacity and 5C discharge capacity, respectively, and the 5C / 1C discharge capacity ratio was calculated according to the following equation.

  5C / 1C discharge capacity ratio (%) = (5C discharge capacity at 6th cycle / 1C discharge capacity at 5th cycle) × 100.

  Furthermore, after this, charging and discharging were repeated 44 times at 1 C, and the charge capacity and discharge capacity of each cycle were measured for a total of 50 cycles.

The capacity retention rate was calculated according to the following formula.
Capacity retention rate (%) = (discharge capacity at 50th cycle / discharge capacity at 5th cycle) × 100.

Synthesis Example 1: Synthesis of Resin A Under a nitrogen stream, NMP 238.10 g, 3,3′-dihydroxybenzidine (manufactured by Wakayama Seika Kogyo Co., Ltd., trade name “HAB”, hereinafter HAB) 10.81 g (0. 05 mol), 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane (manufactured by AZ Electronic Materials Co., Ltd., trade name “AZ 6F-AP”, hereinafter, 6FAP) 18.31 g (0. 05 mol), 4,4′-oxydiphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter referred to as ODPA) 30.40 g (0.098 mol) was dissolved, immersed in an oil bath at 40 ° C. and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ is A 20% NMP solution of resin A having a phenolic hydroxyl group, 50 mol% of R ¹ represented by the general formula (3) and 50 mol% represented by the general formula (4) was obtained.

Synthesis Example 2: Synthesis of Resin B In a dry nitrogen stream, HAB 15.14 g (0.07 mol), 6FAP 10.99 g (0.03 mol), and ODPA 30.40 g (0.098 mol) were dissolved in NMP 226.10 g. It was immersed in an oil bath and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ is A 20% NMP solution of resin B having a phenolic hydroxyl group, 70 mol% of R ¹ represented by the general formula (3) and 30 mol% represented by the general formula (4) was obtained.

Synthesis Example 3: Synthesis of Resin C Under a dry nitrogen stream, 6.49 g (0.03 mol) of HAB, 25.64 g (0.07 mol) of 6FAP, and 30.40 g (0.098 mol) of ODPA were dissolved in 250.10 g of NMP, and 40 ° C. It was immersed in an oil bath and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ is A 20% NMP solution of Resin C having a phenolic hydroxyl group, 30 mol% of R ¹ represented by the general formula (3) and 70 mol% represented by the general formula (4) was obtained.

Synthesis Example 4: Synthesis of Resin D Under dry nitrogen stream, HAB 10.81 g (0.05 mol), 5,5′-methylenebis (2-aminobenzoic acid) (manufactured by Wakayama Seika Kogyo Co., Ltd.) , MBAA) 14.31 g (0.05 mol) and ODPA 30.40 g (0.098 mol) were dissolved, immersed in an oil bath at 40 ° C. and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ is A 20% NMP solution of Resin D having a carboxyl group, 50 mol% of R ¹ represented by the general formula (3) and 50 mol% represented by the general formula (4) was obtained.

Synthesis Example 5: Synthesis of Resin E 16.21 g (0.05 mol) of 2,2′-bis (trifluoromethyl) benzidine (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter referred to as TFMB) to 258.90 g of NMP under a dry nitrogen stream. Then, 18.31 g (0.05 mol) of 6FAP and 30.40 g (0.098 mol) of ODPA were dissolved, immersed in an oil bath at 40 ° C. and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ is A 20% NMP solution of resin E having a phenolic hydroxyl group, 50 mol% of R ¹ represented by the general formula (3) and 50 mol% represented by the general formula (4) was obtained.

Synthesis Example 6: Synthesis of Resin F Under a nitrogen stream, m-tolidine (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter referred to as m-TB) 10.63 g (0.05 mol), 6FAP 18.31 g (0.3. 05 mol) and 30.40 g (0.098 mol) of ODPA were dissolved, immersed in an oil bath at 40 ° C. and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ is A 20% NMP solution of resin F having a phenolic hydroxyl group, 50 mol% of R ¹ represented by the general formula (3) and 50 mol% represented by the general formula (4) was obtained.

Synthesis Example 7 Synthesis of Resin G Under a dry nitrogen stream, HAB 10.81 g (0.05 mol) and 6FAP 18.31 g (0.05 mol) were dissolved in 179.04 g of NMP. Thereafter, the flask was cooled with ice, and trimellitic anhydride chloride (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter referred to as TMAC) dissolved in 20.00 g of NMP was added to the temperature of the solution. The solution was added dropwise while maintaining the temperature at 30 ° C. or lower. After charging the whole amount, the mixture was reacted at 30 ° C. for 4 hours. Thereafter, this solution was poured into 2 L of water, and the resulting precipitate was filtered off and washed three times with 1 L of water. The washed solid is dried in a ventilated oven for 3 days, has 100 mol% of the repeating unit represented by the structure of the general formula (2), R ³ has a phenolic hydroxyl group, and 50 mol% of R ³ Is represented by the general formula (3), and 50 mol% of the resin G solid represented by the general formula (4) was obtained.

Synthesis Example 8: Synthesis of Resin H Under a dry nitrogen stream, HAB 10.81 g (0.05 mol), 6FAP 18.31 g (0.05 mol), pyromellitic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd., below) , PMDA) 21.38 g (0.098 mol) was dissolved, immersed in an oil bath at 40 ° C. and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ is A 20% NMP solution of resin H having a phenolic hydroxyl group, 50 mol% of R ¹ represented by the general formula (3) and 50 mol% represented by the general formula (4) was obtained.

Synthesis Example 9: Synthesis of Resin I Under a dry nitrogen stream, HAB 10.81 g (0.05 mol), 6FAP 18.31 g (0.05 mol), 3,3 ′, 4,4′-benzophenone tetracarboxylic acid (NMP 242.81 g) 31.58 g (0.098 mol) manufactured by Tokyo Chemical Industry Co., Ltd. (hereinafter, BTDA) was dissolved, immersed in an oil bath at 40 ° C. and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ is A 20% NMP solution of Resin I having a phenolic hydroxyl group, 50 mol% of R ¹ represented by the general formula (3) and 50 mol% represented by the general formula (4) was obtained.

Synthesis Example 10: Synthesis of Resin J Under a dry nitrogen stream, HAB 18.38 g (0.085 mol), 6FAP 5.49 g (0.015 mol), and ODPA 30.40 g (0.098 mol) were dissolved in 217.10 g of NMP. It was immersed in an oil bath and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ is A 20% NMP solution of Resin J having a phenolic hydroxyl group, 85 mol% of R ¹ represented by the general formula (3) and 15 mol% represented by the general formula (4) was obtained.

Synthesis Example 11: Synthesis of Resin K Under a dry nitrogen stream, HAB 3.24 g (0.015 mol), 6FAP 31.13 g (0.085 mol), and ODPA 30.40 g (0.098 mol) were dissolved in 259.10 g of NMP. It was immersed in an oil bath and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ is A 20% NMP solution of Resin J having a phenolic hydroxyl group, 15 mol% of R ¹ represented by the general formula (3) and 85 mol% represented by the general formula (4) was obtained.

Synthesis Example 12 Synthesis of Resin L Under a dry nitrogen stream, HAP 18.31 g (0.05 mol) and m-phenylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter referred to as “m-PDA”) were added to NMP 216.48 g. 0.05 mol) and 30.40 g (0.098 mol) of ODPA were dissolved, immersed in an oil bath at 40 ° C. and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ A 20% NMP solution of Resin L in which 50 mol% of R ¹ is represented by the above general formula (3) without containing a phenolic hydroxyl group and a carboxyl group was obtained.

Synthesis Example 13 Synthesis of Resin M Under a dry nitrogen stream, m-PDA 2.16 g (0.02 mol), 6FAP 29.30 g (0.08 mol), and ODPA 30.40 g (0.098 mol) were dissolved in 247.46 g of NMP. It was immersed in an oil bath at 0 ° C. and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ A 20% NMP solution of Resin M having a phenolic hydroxyl group and having 80 mol% of R ¹ represented by the general formula (4) was obtained.

Synthesis example 14: Synthesis | combination of resin N Under dry nitrogen stream, m-PDA 10.27g (0.095 mol) and N-aminophenol (Tokyo Chemical Industry Co., Ltd., MAP) 1.09g (0) to NMP167.06g 0.01 mol) and 30.40 g (0.098 mol) of ODPA were dissolved, immersed in an oil bath at 40 ° C. and stirred for 2 hours. Thereafter, the oil bath is heated to 200 ° C., stirred for 4 hours, and diluted with an appropriate amount of NMP, thereby having 100 mol% of the repeating unit represented by the structure of the general formula (1), and R ¹ A 20% NMP solution of resin N having a phenolic hydroxyl group was obtained.

Synthesis Example 15: Synthesis of Resin O Under a dry nitrogen stream, 179.90 g of NMP was subjected to 4,4′-diisocyanato-3,3′-dimethylbiphenyl (Nippon Soda Co., Ltd., trade name “TODI”, hereinafter, TODI) 21 .14 g (0.08 mol), 4,4-diphenylmethane diisocyanic acid (Tokyo Chemical Industry Co., Ltd., hereinafter referred to as MDI) 5.01 g (0.02 mol), trimellitic anhydride (Tokyo Chemical Industry Co., Ltd.) (Hereinafter, TMA) (18.83 g, 0.098 mol) was dissolved and stirred at room temperature for 2 hours. Thereafter, the flask is heated to 120 ° C. and stirred for 4 hours, further heated to 140 ° C. and stirred for 2 hours, and diluted with an appropriate amount of NMP to be expressed by the structure of the general formula (2). 100 mol% of repeating units, R ¹ does not contain a phenolic hydroxyl group and a carboxyl group, 80 mol% of R ¹ is represented by the general formula (3), and 20 mol% is represented by the general formula (4). A 20% NMP solution of the represented resin O was obtained.

Synthesis Example 16: Synthesis of Resin P Under a dry nitrogen stream, 26.43 g (0.1 mol) of TODI and 18.83 g (0.098 mol) of TMA were dissolved in 181.03 g of NMP and stirred at room temperature for 2 hours. Thereafter, the flask is heated to 120 ° C. and stirred for 4 hours, further heated to 140 ° C. and stirred for 2 hours, and diluted with an appropriate amount of NMP to repeat the structure represented by the structure of the general formula (2). A 20% NMP solution of Resin P having 100 mol% of units, R ¹ containing no phenolic hydroxyl group and carboxyl group and 100 mol% of R ¹ represented by the general formula (3) was obtained.

Synthesis Example 17: Synthesis of Resin Q Under a dry nitrogen stream, 25.03 g (0.1 mol) of MDI and 18.83 g (0.098 mol) of TMA were dissolved in 175.41 g of NMP, and the mixture was stirred at room temperature for 2 hours. Thereafter, the flask is heated to 120 ° C. and stirred for 4 hours, further heated to 140 ° C. and stirred for 2 hours, and diluted with an appropriate amount of NMP to be expressed by the structure of the general formula (2). A 20% NMP solution of Resin Q having 100 mol% of repeating units, R ¹ containing no phenolic hydroxyl group and carboxyl group and 100 mol% of R ¹ represented by the general formula (4) was obtained.

Synthesis example 18: Synthesis | combination of resin R Under dry nitrogen stream, NMP144.98g to Tolylene-2,4-diisocyanate (Tokyo Chemical Industry Co., Ltd., TDI) 17.42g (0.1mol), TMA 18.83g ( 0.098 mol) was dissolved and stirred at room temperature for 2 hours. Thereafter, the flask is heated to 120 ° C. and stirred for 4 hours, further heated to 140 ° C. and stirred for 2 hours, and diluted with an appropriate amount of NMP to be expressed by the structure of the general formula (2). A 20% NMP solution of Resin R having 100 mol% of repeating units and containing no phenolic hydroxyl group and no carboxyl group in R ¹ was obtained.

Synthesis Example 19 Synthesis of Resin S Under a dry nitrogen stream, HAB 10.81 g (0.05 mol) and 6FAP 18.31 g (0.05 mol) were dissolved in 177.26 g of NMP. Thereafter, the flask was ice-cooled and 11.98 g (0.059 mol) of isophthaloyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd., hereinafter IPC) dissolved in 20.00 g of NMP and trimellitic anhydride chloride (Tokyo Chemical Industry). (Hereinafter, TMAC) 8.21 g (0.039 mol) was added dropwise while keeping the temperature of the solution at 30 ° C. or less. After charging the whole amount, the mixture was reacted at 30 ° C. for 4 hours. Thereafter, the temperature of the oil bath was raised to 200 ° C., and the mixture was stirred for 4 hours. This solution was poured into 2 L of water, and the resulting precipitate was filtered off and washed with 1 L of water three times. The washed solid was dried in a ventilated oven for 3 days to obtain a solid of resin S having 40 mol% of repeating units represented by the general formulas (1) and (2).

Synthesis Example 20: Synthesis of Resin T Under a dry nitrogen stream, 10.81 g (0.1 mol) of m-PDA was dissolved in 102.84 g of NMP. Thereafter, the flask was cooled with ice, and 19.90 g (0.098 mol) of IPC dissolved in 20.00 g of NMP was added dropwise while keeping the temperature of the solution at 30 ° C. or lower. After charging the whole amount, the mixture was reacted at 30 ° C. for 4 hours. This solution was poured into 2 L of water, and the resulting precipitate was filtered off and washed 3 times with 1 L of water. The washed solid was dried in a ventilated oven for 3 days to obtain a solid of resin T, which is a nitrogen-containing aromatic resin.

Synthesis Example 21: Synthesis of Resin U In a dry nitrogen stream, 18.2 g of propylene glycol monomethyl ether acetate was introduced and the temperature was raised to 100 ° C. Thereafter, a solution prepared by mixing 7.2 g of acrylic acid, 0.36 g of azobisisobutyronitrile and 13.60 g of propylene glycol monomethyl ether acetate was dropped into the flask from the dropping funnel over 2 hours, and the mixture was further stirred at 100 ° C. for 10 hours. Continued. This solution was poured into 500 mL of hexane, and the resulting precipitate was filtered off and washed 3 times with 250 mL of hexane. The washed solid was dried in a ventilated oven for 3 days to obtain a solid of resin U that was not a nitrogen-containing aromatic resin.

[Example 1]
MW-100LM (manufactured by Sanwa Chemical Co., Ltd., having a cyclic structure) as a thermal crosslinking agent in 5 g of a 20% NMP solution of resin A (resin amount 1 g), 6 methoxymethyl groups as a crosslinkable functional group in one molecule 0.05 g (the amount of thermal cross-linking agent is 0.05 g) and NMP 0.2 g are added and mixed with a rotation / revolution mixer (Sinky Corp., AR-310) until a uniform solution is obtained. A binder composition was obtained.

[Example 2]
Example 1 except that the thermal crosslinking agent was changed to HMOM-TPHAP (Honshu Chemical Industry Co., Ltd., having a cyclic structure and having 6 methoxymethyl groups in one molecule as a crosslinkable functional group) Thus, a binder composition for an electricity storage device was obtained.

[Example 3]
Except for changing the thermal crosslinking agent to MX-270 (manufactured by Sanwa Chemical Co., Ltd., having a cyclic structure and having four methoxymethyl groups in one molecule as a crosslinkable functional group), the same as in Example 1 Thus, a binder composition for an electricity storage device was obtained.

[Example 4]
Except for changing the thermal crosslinking agent to DMOM-PTBP (manufactured by Honshu Chemical Industry Co., Ltd., having a cyclic structure and having two methoxymethyl groups in one molecule as a crosslinkable functional group), the same as in Example 1 Thus, a binder composition for an electricity storage device was obtained.

[Example 5]
Except for changing the thermal crosslinking agent to MX-290 (manufactured by Sanwa Chemical Co., Ltd., having no cyclic structure and having two methoxymethyl groups in one molecule as a crosslinkable functional group), the same as in Example 1 Thus, a binder composition for an electricity storage device was obtained.

[Example 6]
A binder composition for an electricity storage element was obtained in the same manner as in Example 1 except that the resin A was changed to the resin B.

[Comparative Example 1]
A solution of Resin A was used as a binder composition for a storage element without adding a thermal crosslinking agent and NMP.

[Examples 7 to 24, Comparative Example 2]
A binder composition for an electricity storage device was obtained in the same manner as in Example 1 except that the resin, the resin amount, the thermal crosslinking agent, the thermal crosslinking agent amount, and the NMP amount were changed as shown in Table 1.

  Table 2 shows the evaluation results of the film thickness reduction amount, the stress at break, and the number of peeling of the binder compositions for electricity storage devices of Examples 1 to 24 and Comparative Examples 1 and 2.

[Example 25]
As a material capable of occluding and releasing lithium ions (hereinafter referred to as an active material), 4 g of SiO particles (particles composed of a composite material of silicon and silicon oxide; manufactured by Sigma-Aldrich LLC) and spherical graphite (Ito) Graphite Industry Co., Ltd., trade name “SG-BH8”, hereinafter, graphite) 4 g, binder composition for power storage device (solid content concentration 20%) prepared in Example 1 as binder, 1.5 g, and conductivity As a substance, 0.5 g of acetylene black (manufactured by Denka Co., Ltd.) was dispersed in an appropriate amount of NMP to obtain a slurry composition for a storage element. Using this slurry composition, a negative electrode was prepared according to the method described in (6) Preparation of negative electrode, and evaluated according to the method described in (7) Electrode characteristic evaluation.

[Example 26]
A slurry composition for an electricity storage device was obtained in the same manner as in Example 25 except that 4 g of the SiO particles of the active material was changed to 4 g of the C-coated SiO particles obtained in (4) above. Using this slurry composition, a negative electrode was prepared according to the method described in (6) Preparation of negative electrode, and evaluated according to the method described in (7) Electrode characteristic evaluation.

[Example 27]
A slurry composition for an electricity storage element was obtained in the same manner as in Example 25 except that the active material was changed to 8 g of the LTO / Si composite particles obtained in (5) above. Using this slurry composition, a negative electrode was prepared according to the method described in (6) Preparation of negative electrode, and evaluated according to the method described in (7) Electrode characteristic evaluation.

[Example 28]
A slurry composition for an electricity storage element was obtained in the same manner as in Example 25 except that the conductive material was not added. Using this slurry composition, a negative electrode was prepared according to the method described in (6) Preparation of negative electrode, and evaluated according to the method described in (7) Electrode characteristic evaluation.

[Example 29]
A slurry composition for an electricity storage device was obtained in the same manner as in Example 25 except that the binder was changed to 1.5 g of the binder composition (solid content concentration 20%) obtained in Example 2. Using this slurry composition, a negative electrode was prepared according to the method described in (6) Preparation of negative electrode, and evaluated according to the method described in (7) Electrode characteristic evaluation.

[Examples 30 to 59, Comparative Examples 3 to 12]
A slurry composition for an electricity storage device was obtained in the same manner as in Example 25 except that the materials and amounts used were changed as shown in Table 3. Using this slurry composition, a negative electrode was prepared according to the method described in (6) Preparation of negative electrode, and evaluated according to the method described in (7) Electrode characteristic evaluation. In the table, LTO used was commercially available lithium titanate (manufactured by Sigma-Aldrich LLC, trade name “Lithium titanate, spinel”).

  In Table 3, the evaluation result of Examples 25-59 and Comparative Examples 3-12 is shown.

  The binder composition for an electricity storage device of the present invention can be suitably used as a material constituting an electrode of a lithium ion battery, and has an excellent capacity retention rate.

Claims (18)

The binder composition for electrical storage elements containing the nitrogen-containing aromatic resin and the thermal crosslinking agent which has an alkoxymethyl group and / or a methylol group. The binder composition for an electricity storage element according to claim 1, wherein the thermal crosslinking agent has a cyclic structure. The binder composition for an electricity storage element according to claim 1 or 2, wherein the total number of alkoxymethyl groups and methylol groups in the thermal crosslinking agent is 4 or more per molecule. The said nitrogen-containing aromatic resin has a repeating unit represented by the following general formula (1) and / or a repeating unit represented by the following general formula (2), The electrical storage element in any one of Claims 1-3 Binder composition.

(In General Formula (1), R ¹ represents a divalent organic group having 2 to 50 carbon atoms, and R ² represents a tetravalent aromatic organic group having 6 to 50 carbon atoms.)

(In the general formula (2), R ³ represents a divalent organic group having 2 to 50 carbon atoms, and R ⁴ represents a trivalent aromatic organic group having 6 to 50 carbon atoms.) The total content ratio of the repeating unit represented by the general formula (1) and the repeating unit represented by the general formula (2) in the nitrogen-containing aromatic resin is 50 mol% or more. Binder composition for electricity storage device. The binder for an electricity storage device according to claim 4 or 5, wherein either or both of R ¹ in the general formula (1) and R ³ in the general formula (2) are groups having a phenolic hydroxyl group and / or a carboxyl group. Composition. In the nitrogen-containing aromatic resin, when the total of R ¹ in the general formula (1) and R ³ in the general formula (2) is 100 mol%, the structure represented by the following general formula (3) is 20 The binder composition for an electricity storage device according to any one of claims 4 to 6, wherein the binder composition is contained in an amount of not less than mol%.

(In General Formula (3), R ⁵ represents a hydroxy group, a mercapto group, or an organic group having 1 to 6 carbon atoms. P represents an integer of 0 to 4. R ⁵ may be the same or different. ) In the nitrogen-containing aromatic resin, when the total of R ¹ in the general formula (1) and R ³ in the general formula (2) is 100 mol%, the structure represented by the following general formula (4) is 20 The binder composition for an electricity storage element according to any one of claims 4 to 7, wherein the binder composition is contained in an amount of not less than mol%.

(In the general formula (4), R ⁶ represents a hydroxy group, a mercapto group or an organic group having 1 to 6 carbon atoms, and X represents any of a carbonyl group, a methylene group, an isopropyl group, an isopropyl hexafluoride group, and an ether bond. Q represents an integer of 0 to 4. R ⁶ may be the same or different. The slurry composition for electrical storage elements containing the binder composition for electrical storage elements in any one of Claims 1-8, and the substance which can occlude and discharge | release lithium ion. The slurry composition for a storage element according to claim 9, wherein the substance capable of inserting and extracting lithium ions includes at least one of the following (a1) to (a7).
(A1) Silicon (excluding cases corresponding to (a4))
(A2) lithium titanate (a3) silicon oxycarbide (a4) substance in which silicon and silicon oxide are mixed or combined (a5) substance in which two or more of (a1) to (a4) are mixed or combined (However, except when (a1) and (a4) are mixed)
(A6) Substance in which one or more of (a1) to (a4) and carbon are mixed or complexed (a7) Substance whose surface is carbon coated (a1) to (a5) The content of silicon contained in the substance capable of occluding and releasing lithium ions is 5 to 70% by mass, when the mass of the whole substance capable of occluding and releasing lithium ions is 100% by mass. The slurry composition for electrical storage elements as described. Furthermore, the slurry composition for electrical storage elements in any one of Claims 9-11 containing an electroconductive substance. The electrode which has the layer by which the slurry composition for electrical storage elements in any one of Claims 9-12 is formed into a film, or its thermal crosslinking reaction material on the at least single side | surface of a support substrate. The manufacturing method of an electrode including the process of apply | coating the slurry composition for electrical storage elements in any one of Claims 9-12 to the at least single side | surface of a support substrate, and forming the coating film, and the process of drying the said coating film. A secondary battery comprising the electrode according to claim 13. An electric double layer capacitor comprising the electrode according to claim 13. The secondary battery according to claim 15, comprising a nitrogen-containing polar solvent, a sulfur-containing polar solvent, and / or a lactone in a total amount of 0.05% by mass or more of the total electrolyte solution mass. The electric double layer capacitor according to claim 16, comprising a nitrogen-containing polar solvent, a sulfur-containing polar solvent and / or a lactone as a total amount of 0.05% or more of the total electrolyte mass.