Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
  • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
  • C08F20/10—Esters
  • C08F20/12—Esters of monohydric alcohols or phenols
  • C08F20/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F20/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
  • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/052—Li-accumulators
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
  • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
  • H01M10/0565—Polymeric materials, e.g. gel-type or solid-type

Definitions

• the present invention relates to a solid or gel electrolyte, a curable composition, and an electric storage device, and more specifically to a polymer solid electrolyte and polymer gel electrolyte, and their use.
• lithium ion secondary batteries are used in a wide range of applications because of their high energy density and battery capacity.
• a lithium-ion secondary battery is a secondary battery that has a negative electrode, a positive electrode, and an electrolyte, and charges and discharges by moving lithium ions between the two electrodes through the electrolyte.
• an organic electrolytic solution has been mainly used as the electrolyte.
• Patent Document 1 discloses a polymer solid electrolyte produced by polymerizing a monomer having a carbonate skeleton that coordinates lithium ions in the presence of an electrolyte salt.
• Non-Patent Document 1 discloses a polymer solid electrolyte produced by dissolving a polymer obtained by polymerizing a monomer having a carbonate skeleton and an electrolyte salt in a solvent.
• the present invention has been made in view of such circumstances, and its object is to provide a solid or gel electrolyte that exhibits high ionic conductivity at room temperature.
• a vinyl polymer having a specific structure can contain an alkali metal salt at a specific concentration or higher, and the vinyl polymer and the alkali
• a solid or gel electrolyte containing a metal salt has high ionic conductivity even at room temperature, and have completed the present invention.
• Ingredients: Alkali metal salt (where i 1, 2, ..., n represents different vinyl monomers.
• w represents the mass ratio of structural units derived from each vinyl monomer in component (A), w 1 +w 2 + . . .
• the component (A) includes a compound represented by the following general formula [1], a compound represented by the general formula [2], a compound represented by the general formula [3], and a compound represented by the general formula [4]
• R 1 represents a hydrogen atom or a methyl group
• R 2 represents a saturated organic group having 1 to 4 carbon atoms
• the total number of carbon atoms of R 1 and R 2 is 1 to 4.
• R 1 and R 3 represent a hydrogen atom or a methyl group.
• R 4 represents a saturated organic group having 1 to 4 carbon atoms.
• R 1 represents a hydrogen atom or a methyl group
• R 5 represents an organic group having 1 to 6 carbon atoms.
• a curable composition used for producing a solid or gel electrolyte A curable solid or gel electrolyte containing the following components (a) and (B), and having a molar concentration of the component (B) with respect to 1 kg of the curable composition of 2.8 mol/kg or more. Composition.
• Component (a) a vinyl-based monomer component containing a vinyl monomer containing an ester group and having an ester group ratio calculated by formula (2) of 32% by mass or more
• the component (a) includes a compound represented by the following general formula [1], a compound represented by the general formula [2], a compound represented by the general formula [3], and a compound represented by the general formula [4]
• R 1 and R 3 represent a hydrogen atom or a methyl group.
• R 4 represents a saturated organic group having 1 to 4 carbon atoms.
• R 1 represents a hydrogen atom or a methyl group
• R 5 represents an organic group having 1 to 6 carbon atoms.
• the total number of carbon atoms of R 1 and R 5 is 1 to 6.
• the solid or gel electrolyte of the present invention can exhibit high ionic conductivity at room temperature. Therefore, by using the solid or gel electrolyte of the present invention as an electrolyte for an electricity storage device such as a lithium ion secondary battery or a capacitor, it is possible to obtain an electricity storage device that achieves both safety and battery performance.
• (meth)acryl means acryl and/or methacryl
• (meth)acrylate means acrylate and/or methacrylate
• the solid or gel electrolyte of the present invention includes a polymer solid electrolyte or polymer gel electrolyte, and contains the following components (A) and (B).
• the molar concentration of component (B) relative to 1 kg of electrolyte is 2.8 mol/kg or more.
• the vinyl polymer (A) component (hereinafter also referred to as "vinyl polymer (A)") has a structural unit derived from a vinyl monomer containing an ester group, and has the above formula ( When the ester group ratio calculated in 1) is 32% by mass or more, the alkali metal salt can be dissolved at a high concentration, and the ionic conductivity (particularly, the ionic conductivity at room temperature) can be increased.
• the solid or gel electrolyte of the present invention is a decoupling system in which the movement of the alkali metal salt is less likely to be affected by the mobility of the polymer chain, and the diffusion of the alkali metal salt is not inhibited even when the concentration of the alkali metal salt is high. It is presumed to be due to the fact that The ester group ratio of the vinyl-based polymer (A) is 34% by mass because the content of the alkali metal salt (B) in the solid or gel electrolyte can be increased and the ionic conductivity can be further improved. It is preferably at least 37% by mass, more preferably at least 37% by mass, even more preferably at least 40% by mass, even more preferably at least 45% by mass, and even more preferably at least 50% by mass. preferable.
• the vinyl polymer (A) is a vinyl monomer (hereinafter also referred to as "vinyl monomer M") containing an ester group and having an ester group ratio of 32% by mass or more as calculated by the above formula (2). It may be a polymer obtained by polymerizing a vinyl-based monomer component containing the vinyl-based monomer component.
• a (meth)acrylic monomer is used because it is easy to introduce a structural unit derived from a vinyl monomer containing an ester group into the side chain of the polymer and it is easy to produce industrially.
• the vinyl polymer (A) is preferably a (meth)acrylic polymer.
• the ratio of the structural units derived from the (meth)acrylic monomer is preferably more than 50% by mass, and 60% by mass. It is more preferably at least 70% by mass, even more preferably at least 80% by mass, and even more preferably at least 90% by mass.
• the proportion of the acrylic monomer is preferably 40% by mass or more, more preferably 50% by mass or more, and still more preferably 60% by mass or more. 80% by mass or more is even more preferable.
• the proportion of the acrylic monomer is within the above range, the glass transition temperature of the vinyl polymer (A) can be sufficiently lowered, and a solid or gel electrolyte with higher ionic conductivity can be obtained. is.
• the vinyl monomer M is not particularly limited as long as it contains an ester group and the ester group ratio calculated by the above formula (2) is 32% by mass or more, but the following general formula [1] At least one compound selected from the group consisting of the compound represented by the general formula [2], the compound represented by the general formula [3], and the compound represented by the general formula [4] It preferably contains a compound.
• R 1 represents a hydrogen atom or a methyl group
• R 2 represents a saturated organic group having 1 to 4 carbon atoms
• the total number of carbon atoms of R 1 and R 2 is 1 to 4.
• R 1 and R 3 represent a hydrogen atom or a methyl group.
• R 4 represents a saturated organic group having 1 to 4 carbon atoms.
• R 1 represents a hydrogen atom or a methyl group
• R 5 represents an organic group having 1 to 6 carbon atoms.
• the total number of carbon atoms of R 1 and R 5 is 1 to 6.
• the compound represented by the above general formula [4] is particularly preferable in that the ionic conductivity (particularly, the ionic conductivity at room temperature) can be increased.
• Specific examples of the compound represented by the general formula [1] include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, and n-acrylate.
• the vinyl monomer M constituting the vinyl-based polymer (A) may be of one type alone or two or more types.
• R 1 is a hydrogen atom and R 2 is a saturated organic group having 1 or 2 carbon atoms, more preferably methyl acrylate or ethyl acrylate, acrylic Methyl acid is more preferred.
• R 2 is a saturated organic group having 1 or 2 carbon atoms, more preferably methyl acrylate or ethyl acrylate, acrylic Methyl acid is more preferred.
• a compound (2-methoxyethyl acrylate) in which R 1 is a hydrogen atom and R 3 is a methyl group is more preferable.
• the compound represented by the general formula [3] is preferably a compound in which R4 is a saturated organic group having 1 or 2 carbon atoms, more preferably vinyl acetate or vinyl propionate, and still more preferably vinyl acetate.
• R 1 is a hydrogen atom or a methyl group
• R 5 is an organic group having 2 to 6 carbon atoms
• the total number of carbon atoms of R 1 and R 5 is 2 to 6, more preferably 2-(meth)acryloyloxyethyl-succinic acid, 2-acryloyloxyethyl-phthalic acid, and even more preferably 2-(meth)acryloyloxyethyl-succinic acid.
• the vinyl-based polymer (A) may be composed only of structural units derived from the vinyl monomer M, but furthermore, it is other than the vinyl monomer M and is copolymerized with the vinyl monomer M. It may have a structural unit derived from a possible monomer (hereinafter also referred to as "another monomer”). However, even if the vinyl monomer is classified as other monomers, the monomer containing an ester group and having an ester group ratio calculated by the above formula (2) of 32% by mass or more is , vinyl monomer M.
• Other monomers include, for example, vinyl monomers having a crosslinkable group (hereinafter also referred to as "crosslinkable monomers").
• a tough electrolyte membrane can be obtained when a solid or gel electrolyte is made into a membrane, and a polymer gel. It is suitable in that it can sufficiently retain the electrolytic solution when used as an electrolyte.
• a polyfunctional (meth)acrylate compound having two or more (meth)acryloyl groups can be preferably used as the crosslinkable monomer.
• polyfunctional (meth)acrylate compounds include 1,6-hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerin di(meth)acrylate, glycerin tri (meth)acrylates, tri- or tetra-(meth)acrylates of pentaerythritol, tri- or tetra-(meth)acrylates of ditrimethylolpropane, tri- or tetra-(meth)acrylates of diglycerin, and tri-, tetra-, penta- or dipentaerythritol
• polyol poly(meth)acrylates such as hexa(meth)acrylate
• the monomers constituting the vinyl-based polymer (A) may contain compounds other than crosslinkable monomers as other monomers within a range that does not impair the effects of the present invention.
• the compound may contain an ester group and have an ester group ratio calculated by the above formula (2) of less than 32% by mass. Examples include (meth)acrylic acid and (meth)acrylic acid alkyl ester compounds.
• the ratio of the structural units derived from the vinyl monomer M depends on the ionic conductivity (particularly, the ionic conductivity at room temperature). From the viewpoint of obtaining an excellent electrolyte, it is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and even more preferably 80% by mass or more.
• the upper limit of the ratio of structural units derived from the vinyl monomer M is not particularly limited.
• the ratio of the structural units derived from the vinyl monomer M to the total structural units derived from the monomers constituting the vinyl polymer (A) is, for example, 99% by mass. or less, preferably 97% by mass or less.
• the ratio of the structural units derived from the crosslinkable monomer is determined from the viewpoint of sufficiently forming the crosslinked structure and the membrane-like electrolyte. From the viewpoint of imparting toughness in the case of .
• the ratio of the electrolyte to the total structural units derived from the monomers constituting the vinyl polymer (A) is From the viewpoint of ensuring flexibility, the content is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.
• the range of the ratio of the structural units derived from the crosslinkable monomer to the total structural units of the vinyl polymer (A) can be set by appropriately combining the upper and lower limits described above.
• the ratio of structural units derived from a crosslinkable monomer to all structural units derived from monomers constituting the vinyl polymer (A) is preferably 1 to 30% by mass. , more preferably 2 to 20% by mass, even more preferably 3 to 20% by mass, and even more preferably 3 to 15% by mass.
• the glass transition temperature (Tg) of the vinyl polymer (A) is preferably 100°C or lower, more preferably 75°C or lower, still more preferably 50°C or lower, still more preferably 25°C or lower, and even more preferably 5°C or lower.
• the lower limit of the Tg of the vinyl polymer (A) is not particularly limited, it is -70°C or higher, for example.
• Tg of a polymer is a value measured by differential scanning calorimetry (DSC).
• alkali metal salt as component (B) is not particularly limited, and examples of alkali metals constituting the alkali metal salt include lithium, sodium, potassium, rubidium, cesium, and francium, and lithium, sodium, and potassium. is preferred, and lithium is more preferred.
• alkali metal salts include alkali metal salts of fluorosulfonic acid such as LiFSO3 ; alkali metal salts of trifluoromethanesulfonic acid such as LiCF3SO3 ; imide-based alkali metal salts such as LiN( FSO2 ) 2 ; alkali metal salts of perfluoroalkanesulfonyl methides such as CF 3 SO 2 ) 3 ; fluorophosphates such as LiPF a (C m F 2m+1 ) 6-a (0 ⁇ a ⁇ 6, 1 ⁇ m ⁇ 2); alkali metal perchlorates such as LiClO 4 ; fluoroborates such as LiBF b (C n F 2n+1 ) 4-b (0 ⁇ b ⁇ 4, 1 ⁇ n ⁇ 2); alkali metal oxalatoborate such as LiBOB Salts; cyanoborates such as lithium tetracyanoborate; alkali metal salts such as LiAsF6 , LiF
• MtlN SO2R1 )( SO2R2 ) [ 5]
• M tl represents an alkali metal ion.
• R 1 and R 2 are the same or different and represent a fluorine atom or a fluoroalkyl group having 1 to 3 carbon atoms.
• Alkali metals in Mtl are as described above.
• the fluoroalkyl group having 1 to 3 carbon atoms in R 1 and R 2 may be a hydrocarbon group having 1 to 3 carbon atoms and at least one hydrogen atom thereof is substituted with a fluorine atom, and is a fluoromethyl group.
• R 1 and R 2 are preferably a fluorine atom, a trifluoromethyl group and a pentafluoroethyl group, more preferably a fluorine atom and a trifluoromethyl group, and still more preferably a fluorine atom.
• Examples of the imide-based alkali metal salt represented by the general formula [5] include “lithium bis(fluorosulfonyl)imide” in which M tl is lithium and R 1 and R 2 are fluorine atoms, M tl is lithium and R Particularly preferred is “lithium (fluorosulfonyl)(trifluoromethanesulfonyl)imide” in which 1 is a fluorine atom and R 2 is a trifluoromethyl group.
• the solid or gel electrolyte of the present invention has, together with an alkali metal salt, a structural unit derived from a vinyl monomer containing an ester group as a polymer component, and an ester group calculated by the above formula (1) It contains a vinyl polymer (A) with a ratio of 32% by mass or more. In this case, even when the concentration of the alkali metal salt in the solid or gel electrolyte is increased, precipitation of the alkali metal salt is less likely to occur, and a solid or gel electrolyte with high ion conductivity can be obtained.
• the molar concentration of the component (B) in the solid or gel electrolyte is 2.8 mol/kg or more per 1 kg of the electrolyte. If the molar concentration of component (B) is less than 2.8 mol/kg, the ionic conductivity of the electrolyte is not sufficient, and is high when applied to a polymer solid electrolyte or polymer gel electrolyte for lithium ion secondary batteries. There is concern that the output cannot be realized. From this point of view, the molar concentration of component (B) is preferably 2.9 mol/kg or more, more preferably 3.0 mol/kg or more, and still more preferably 3.2 mol/kg or more, relative to 1 kg of electrolyte.
• the molar concentration Db [mol/kg] of the component (B) in the solid or gel electrolyte is represented by the following formula (3).
• Db (Mb/WL) (3)
• Mb is the number of moles (unit: mol) of the component (B) contained in the solid or gel electrolyte
• WL is the mass (unit: kg) of the solid or gel electrolyte.
• the upper limit of the molar concentration of component (B) in the solid or gel electrolyte of the present invention can be appropriately set depending on whether the target substance is a solid polymer electrolyte or a polymer gel electrolyte.
• the molar concentration of the component (B) in the solid polymer electrolyte is preferably 4.5 mol/kg or less, more preferably 4.2 mol/kg or less, relative to 1 kg of the electrolyte.
• the molar concentration of the component (B) in the polymer gel electrolyte is preferably 5.0 mol/kg or less, more preferably 4.5 mol/kg or less, relative to 1 kg of the electrolyte.
• the solid or gel electrolyte of the present invention may contain other components, if necessary, in addition to the components (A) and (B) described above.
• a polymer gel electrolyte When producing a polymer gel electrolyte as the solid or gel electrolyte of the present invention, it may further contain an electrolytic solution (component (C)).
• the polymer gel electrolyte is in a state where the polymer component is swollen by the electrolytic solution, so it is possible to suppress liquid leakage while containing the electrolyte, and to reduce the amount of volatilization of the electrolytic solution, which is effective in improving safety.
• the electrolytic solution a solvent known as an electrolytic solution for a polymer gel electrolyte can be appropriately used.
• component (C) include chain carbonates, cyclic carbonates, cyclic esters, ethers, pyrrolidones, acetonitrile, sulfolane compounds, phosphoric acids, and phosphate esters. Specific examples of these include chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethylmethyl carbonate. Cyclic carbonates include ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate and the like. Cyclic esters include ⁇ -butyrolactone, ⁇ -valerolactone, ⁇ -valerolactone, ⁇ -caprolactone and the like.
• Ethers include 1,2-dimethoxyethane, 1-ethoxy-2-methoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane and the like.
• the electrolytic solution one type may be used alone, or two or more types may be used in combination.
• At least one electrolyte selected from the group consisting of cyclic carbonates, cyclic esters and cyclic ethers is preferable, and cyclic carbonates are particularly preferable, in that the ionic conductivity of the polymer gel electrolyte can be improved. preferable.
• the content of the electrolytic solution in the polymer gel electrolyte is usually 25-99% by mass, preferably 30-90% by mass, relative to the total amount of the polymer gel electrolyte.
• component (D) component inorganic compound
• component (D) includes metallic or nonmetallic elements such as silicon, aluminum, titanium, barium, calcium, potassium, zinc, magnesium, niobium, tantalum, tungsten, antimony, tin, boron, yttrium, zirconium, cerium, and phosphorus.
• Inorganic oxides, inorganic oxynitrides, inorganic sulfides, inorganic nitrides, inorganic oxycarbides, inorganic oxycarbonitrides", etc., containing the inorganic Oxides are preferred.
• the inorganic oxides include silica, alumina, titanium oxide, barium titanate, calcium oxide, zinc oxide, magnesium oxide, niobium oxide, tantalum oxide, tungsten oxide, and antimony oxide.
• the inorganic oxide may be one that functions as an oxide- based inorganic solid electrolyte. 4 ) 3 , Li 1+x Al x Ge 2-x (PO 4 ) 3 and the like.
• Component (D) may be used singly or in combination of two or more in any ratio.
• the content of the inorganic compound in the polymer gel electrolyte is generally 1-50% by mass, preferably 3-30% by mass, based on the total amount of the polymer solid or gel electrolyte.
• components that the solid or gel electrolyte of the present invention may contain include, in addition to the component (D), fillers other than the component (D), leveling agents, and the like.
• the content of other components can be appropriately set according to each compound within a range in which the performance of the electrolyte is not deteriorated.
• the total mass ratio of components (A), (B) and (D) is 95% by mass or more.
• the total mass ratio of the components (A), (B), (C) and (D) is preferably 95% by mass or more.
• the method for producing the solid or gel electrolyte of the present invention is not particularly limited.
• Methods for producing the solid or gel electrolyte of the present invention include the following method 1 and method 2.
• Methods for producing the solid or gel electrolyte of the present invention include the following method 1 and method 2.
• Methods for producing the solid or gel electrolyte of the present invention include the following method 1 and method 2.
• Methods for producing the solid or gel electrolyte of the present invention include the following method 1 and method 2.
• Method 1 Curing containing the monomer component as the component (a) and the component (B), and the molar concentration of the component (B) relative to 1 kg of the curable composition is 2.8 mol/kg or more
• a method of curing a mold composition ie, a curable composition for a solid or gel electrolyte).
• Method 2 A polymer composition containing the above components (A) and (B), and a solvent, wherein the molar concentration of component (B) relative to 1 kg of the curable composition is 2.8 mol/kg or more. A method of coating an object and evaporating the solvent.
• a curable composition for a solid or gel electrolyte (hereinafter also simply referred to as a "curable composition”) is formed into a polymer solid electrolyte and a polymer gel electrolyte by the progress of a curing reaction, for example, by heat or active energy rays.
• a curable composition capable of forming That is, the curable composition may be used as a thermosetting composition or as an active energy ray-curable composition.
• the thermosetting composition is preferable because it can be cured in the cell after impregnating the electrode with the curable composition, and the curing reaction can be easily and sufficiently advanced. point, it is preferably an active energy ray-curable composition.
• the following (a) is used as a vinyl monomer that constitutes the polymer component of the solid polymer electrolyte and the polymer gel electrolyte together with the component (B), which is an alkali metal salt.
• component (B) which is an alkali metal salt.
• the (a) component may have a monomer composition that allows the vinyl polymer (A) described above to be obtained by curing the curable composition containing the (a) component and the (B) component.
• the component (a) contains a vinyl monomer M, and if necessary, a cross-linkable monomer and other monomers other than the cross-linkable monomer together with the vinyl monomer M.
• the mass ratio of the vinyl monomer M and the crosslinkable monomer in the curable composition the mass of the vinyl monomer M and the crosslinkable monomer with respect to the total structural units of the vinyl polymer (A) Equivalent to a percentage.
• the (a) component may contain only 1 type of vinyl monomers, and may contain 2 or more types.
• the curable composition may contain other components as necessary within a range that does not impair the effects of the present invention.
• Other components include, for example, the electrolytic solution described above, a polymerization initiator, and the like.
• the electrolytic solution is added to the curable composition when producing a polymer gel electrolyte using the curable composition of the present invention.
• Specific examples of the electrolytic solution to be blended in the curable composition include the same electrolytic solutions as exemplified in the description of the solid or gel electrolyte.
• the mixing ratio of the electrolytic solution is preferably 25 parts by mass or more, more preferably 30 parts by mass or more, with respect to 100 parts by mass of the total amount of the curable composition.
• the upper limit of the mixing ratio of the electrolytic solution is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, with respect to 100 parts by mass of the total amount of the curable composition.
• the polymerization initiator is blended into the curable composition together with the components (a) and (B) for the purpose of allowing the polymerization reaction to proceed sufficiently.
• known polymerization initiators such as thermal decomposition type and photoinitiation type can be used depending on the means of polymerization initiation.
• the polymerization initiator contained in the curable composition is preferably a photoinitiation polymerization initiator (photopolymerization initiator).
• photopolymerization initiators include benzoin and its alkyl ethers, acetophenones, anthraquinones, thioxanthones, ketals, benzophenones, xanthones, acylphosphine oxides, ⁇ -diketones, ⁇ -hydroxy ketones and the like. If necessary, a benzoic acid-based or amine-based photosensitizer may be used in combination in order to improve the sensitivity to the active energy ray irradiated to obtain the vinyl polymer (A).
• the content of the polymerization initiator in the curable composition is, for example, 0.1 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the curable composition. be able to. From the viewpoint of sufficiently advancing the polymerization reaction, the content of the polymerization initiator is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of the total amount of the curable composition. be.
• the upper limit of the content of the polymerization initiator is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, from the viewpoint of moderately causing gelation when obtaining a polymer gel electrolyte. When obtaining a polymer solid electrolyte, the amount is preferably 12 parts by mass or less, more preferably 10 parts by mass or less.
• a combination of a thermal polymerization initiator and a photopolymerization initiator may be used as polymerization initiators, and after performing a curing reaction with active energy rays, heat curing may be performed for the purpose of further improving the reaction rate.
• heat curing may be performed for the purpose of further improving the reaction rate.
• the curable composition can be obtained by mixing the above-described components (a) and (B), and other components blended as necessary.
• the mixture may be stirred while being heated, if necessary.
• the temperature when stirring and mixing while heating is preferably in the range of 40 to 90°C.
• the temperature at which the thermal polymerization initiator does not thermally decompose for example, 30 ° C. or less, in order to suppress the progress of polymerization during the production of the curable composition. It is preferable to use
• a solvent-free curable composition that does not contain a solvent such as an organic solvent can be used to adjust the film thickness (e.g., thickening the film) when producing a film-like solid or gel electrolyte using the curable composition. ) can be easily performed.
• a curable composition containing a solvent such as an organic solvent can easily produce a curable composition containing the component (B) at a high concentration (in this case, the solvent promotes dissolution of the component (B).
• the method for producing a solid or gel electrolyte using a curable composition is not particularly limited.
• the curable composition of the present invention is applied to a substrate or electrode (positive electrode, negative electrode), then one or both of irradiation with active energy rays and heat application are performed, and the substrate or electrode (positive electrode, negative electrode) ), a polymer solid electrolyte or polymer gel electrolyte can be produced by curing the curable composition applied to the above.
• the base material can be appropriately selected according to the application, and among them, a resin film can be preferably used.
• the resin material that constitutes the resin film include polyester-based resins (eg, polyethylene terephthalate (PET), etc.), polyethersulfone-based resins, acetate-based resins, polycarbonate-based resins, polyolefin-based resins, and the like.
• the coated surface of the substrate to which the curable composition is applied may be subjected to release treatment.
• the release treatment include silicone treatment, long-chain alkyl treatment and fluorine treatment.
• a solid or gel electrolyte can be produced by thermally curing the curable composition.
• a separator porous film
• a separator is impregnated with a curable composition, and if necessary, it is sandwiched between films such as PET films and irradiated with an active energy ray, and after polymerization, the film is removed to remove the film between the electrodes. It may be a solid or gel electrolyte.
• materials for the separator include PE (polyethylene, preferably ultra-high molecular weight polyethylene), PP (polypropylene), polyimide, glass nonwoven fabric, and the like.
• the curable composition obtained by mixing the curable composition of the present invention with the electrode (positive electrode, negative electrode) preparation composition is applied to a current collector and then cured to form a solid or solid between the electrode active materials. Electrodes containing gel electrolytes may be fabricated.
• the coating method can be appropriately set according to the coating target and purpose.
• coating methods include bar coaters, applicators, doctor blades, dip coaters, roll coaters, spin coaters, flow coaters, knife coaters, comma coaters, reverse coaters, die coaters, lip coaters, gravure coaters, micro gravure coaters, A coating method such as an inkjet can be used.
• the amount of the curable composition to be applied can be appropriately selected depending on the intended use, etc. so that the film thickness of the cured product obtained by irradiation with active energy rays is within the desired range.
• examples of the active energy ray with which the curable composition is irradiated include ultraviolet rays, visible rays, electron beams, and the like. Among these, ultraviolet rays or electron beams are preferable.
• the mode of irradiating the curable composition coated on the substrate or electrode with activation energy is not particularly limited.
• the activation energy irradiation may be performed only on one surface of the substrate coated with the curable composition, or on both surfaces. you can go Irradiation energy can be appropriately set according to the type of active energy ray, the composition of the curable composition, and the like.
• the wavelength is, for example, 250 to 400 nm.
• the ultraviolet irradiation device include a high pressure mercury lamp, a metal halide lamp, an ultraviolet electrodeless lamp, and an ultraviolet light emitting diode (UV-LED).
• the integrated amount of light is preferably 500 mJ/cm 2 or more, more preferably 1,000 mJ/cm 2 or more, and even more preferably 1,500 mJ/cm 2 or more.
• the upper limit of the integrated amount of light is preferably 25,000 mJ/cm 2 or less, more preferably 20,000 mJ/cm 2 or less, from the viewpoint of minimizing the influence on each component in the curable composition and from the viewpoint of energy reduction. .
• the illuminance and irradiation time of the ultraviolet rays can be appropriately set so that the integrated amount of light becomes a desired amount.
• the illuminance is preferably 0.5 mW/cm 2 or higher, more preferably 1.0 mW/cm 2 or higher, and even more preferably 2.0 mW/cm 2 or higher.
• the upper limit of the illuminance is preferably 100 mW/cm 2 or less, more preferably 80 mW/cm 2 or less, and even more preferably 50 mW/cm 2 or less.
• the electron beam irradiation device is not particularly limited, but examples thereof include Cockcroft-Walton type, Van de Graaff type and resonance transformer type devices.
• the absorption dose of the electron beam is preferably 1 to 200 kGy, more preferably 10 to 100 kGy.
• the acceleration voltage of the electron beam may be appropriately set within the range of 80 to 300 kV according to the thickness of the coating object such as the base material.
• the oxygen concentration in the electron beam irradiation atmosphere is preferably 500 ppm or less, more preferably 300 ppm or less.
• the heating temperature and heating time can be appropriately set according to the type of polymerization initiator, etc., according to the usual means of radical thermal polymerization.
• the heating temperature for thermosetting is preferably 30 to 120° C., preferably 40 to 80° C., from the viewpoint of the heat resistance of the pouch cell material when the curable composition is injected into the cell and then the thermosetting reaction proceeds.
• the heating time for thermosetting can be appropriately set according to the type of polymerization initiator and the like.
• the film thickness can be appropriately set according to the application.
• the film thickness of the solid or gel electrolyte is, for example, 10 ⁇ m or more and 5,000 ⁇ m or less, preferably 50 ⁇ m or more and 3,000 ⁇ m or less.
• the polymer composition used in method 2 can be obtained by dissolving or dispersing the vinyl polymer (A) as the component (A) and the specific alkali metal salt as the component (B) in a solvent.
• An organic solvent can be preferably used as the solvent.
• Specific examples of organic solvents include aprotic polar solvents, phenol solvents, alcohol solvents, ester solvents, ketone solvents, ether solvents, hydrocarbon solvents and the like.
• the organic solvent may be one of these, or a mixed solvent of two or more.
• electrolyte solution as at least one part of a solvent.
• the method for producing the vinyl polymer (A) to be blended in the polymer composition is not particularly limited.
• a vinyl polymer (A ) may be produced.
• the vinyl polymer (A) may be produced by curing a mixture of a monomer component containing the vinyl monomer M and a polymerization initiator with heat or active energy rays.
• the solid content concentration in the polymer composition (that is, the ratio of the mass of components other than the solvent in the polymer composition to the total mass of the polymer composition) is not particularly limited, but is preferably 10 to 70% by mass. be. By setting the solid content concentration to 10% by mass or more, an electrolyte membrane having a sufficient thickness can be formed. When the solid content concentration is 70% by mass or less, good coatability can be ensured, and an electrolyte membrane having a uniform thickness can be easily formed.
• the solid content concentration in the polymer composition is more preferably 15 to 60% by mass, still more preferably 20 to 50% by mass.
• the polymer composition is applied to a substrate or an electrode (positive electrode, negative electrode) by a known coating method, followed by drying treatment such as heating and pressure reduction.
• a polymer solid electrolyte can be formed on the substrate or the electrode by removing the solvent.
• a method of forming an electrolyte in the same manner as the solid polymer electrolyte and then contacting it with an electrolytic solution to swell the polymer component A polymer gel electrolyte can be produced by a method of gelling a sol-like polymer composition further containing
• the solid or gel electrolyte of the present invention exhibits sufficient ionic conductivity even at room temperature (30°C).
• the ionic conductivity of the solid or gel electrolyte is preferably 1.0 ⁇ 10 ⁇ 9 S/cm or more, more preferably 1.0 ⁇ 10 ⁇ 8 S/cm or more at 30° C. is more preferably 1.0 ⁇ 10 ⁇ 7 S/cm or more, even more preferably 1.0 ⁇ 10 ⁇ 6 S/cm or more, and 1.0 ⁇ 10 ⁇ 5 S /cm or more, and even more preferably 1.0 ⁇ 10 ⁇ 4 S/cm or more.
• the ionic conductivity of a solid or gel electrolyte is a value calculated by sandwiching the solid or gel electrolyte between a pair of stainless steel plates and measuring the impedance between the stainless steel plates. The details of the method for measuring the ionic conductivity are described in the examples below.
• the electricity storage device of the present invention (hereinafter also referred to as "this device") comprises a solid or gel electrolyte.
• this device include a secondary battery, a capacitor, and the like.
• the present device is a secondary battery, one aspect thereof is a gel battery, and a lithium ion secondary battery, a sodium ion secondary battery, and a potassium ion secondary battery are preferable from the viewpoint of excellent ion conductivity.
• the lithium ion secondary battery of the present disclosure includes the solid or gel electrolyte of the present invention described above.
• One aspect of a lithium ion secondary battery includes a positive electrode, a negative electrode, and a solid or gel electrolyte, and is formed by disposing the solid or gel electrolyte as an electrolyte between the positive electrode and the negative electrode.
• Materials constituting the positive electrode and the negative electrode are not particularly limited, and can be appropriately selected and used from known electrode materials for lithium ion secondary batteries.
• the solid or gel electrolyte of the present invention When the solid or gel electrolyte of the present invention is used as an electrolyte for a lithium ion secondary battery, it exhibits high ion conductivity even at room temperature.
• solid or gel electrolytes using polyethylene oxide polymers which are generally known as solid or gel electrolytes, have a higher alkali metal salt concentration, a higher Tg of the solid or gel electrolyte, and a higher flexibility. tend to lose.
• the solid or gel electrolyte of the present invention has a high alkali metal salt concentration of 2.8 mol/kg or more, the flexibility of the solid or gel electrolyte is high, and thus a flexible secondary battery can be obtained. It is also useful for manufacturing.
• the present device may be a capacitor.
• the solid or gel electrolyte is provided with an anode body and a cathode body, and the solid or gel electrolyte is arranged between the anode body and the cathode body so that the solid electrolyte and the electrode are in contact with each other. configuration.
• the electric storage device comprising the solid or gel electrolyte of the present invention can be applied to various uses. Specifically, for example, various mobile devices such as mobile phones, personal computers, smartphones, game devices, and wearable terminals; various moving objects such as electric vehicles, hybrid vehicles, robots, and drones; digital cameras, video cameras, music players, It can be used as a power source in various electric/electronic devices such as tools and home electric appliances.
• various mobile devices such as mobile phones, personal computers, smartphones, game devices, and wearable terminals
• various moving objects such as electric vehicles, hybrid vehicles, robots, and drones
• digital cameras, video cameras, music players It can be used as a power source in various electric/electronic devices such as tools and home electric appliances.
• reaction rate of the vinyl monomer and the ionic conductivity were measured by the following methods.
• ⁇ Measurement of reaction rate of vinyl monomer> The reaction rate of the acrylic monomer by active energy ray curing was obtained by measuring by the micro ATR method using an infrared absorption spectrometer (Spectrum 100 manufactured by Perkin Elmer Japan). Specifically, using the obtained infrared absorption spectrum, the reaction rate of the acryloyl group was calculated according to the following formula (4).
• Reaction rate of acryloyl group ⁇ 1 ⁇ (B 2 /A 2 )/(B 1 /A 1 ) ⁇ 100 (4)
• a 1 Peak height of 1730 cm ⁇ 1 derived from “—C ⁇ O” of the curable composition
• B 1 Peak height of 810 cm ⁇ 1 derived from “—CH ⁇ CH 2 ” of the curable composition
• reaction rate of the compound represented by the general formula [3] by active energy ray curing was obtained by measuring by the micro ATR method using an infrared absorption spectrometer (Spectrum 100 manufactured by PerkinElmer Japan). Specifically, using the obtained infrared absorption spectrum, the reaction rate of the vinyl group was calculated according to the following formula (5).
• Reaction rate of vinyl group ⁇ 1 ⁇ (B′ 2 /A′ 2 )/(B′ 1 /A′ 1 ) ⁇ 100 (5)
• A′ 1 Peak height of 1730 cm ⁇ 1 derived from “—C ⁇ O” of the curable composition
• B′ 1 Peak height of 940 cm ⁇ 1 derived from “—CH ⁇ CH 2 ” of the curable composition
• ⁇ L/(R x S) (6)
• ⁇ is the ionic conductivity (unit: S cm ⁇ 1 )
• R is the resistance (unit: ⁇ )
• S is the cross-sectional area of the polymer solid electrolyte membrane or polymer gel electrolyte membrane when measured. (Unit: cm 2 ), L indicates the inter-electrode distance (unit: cm).)
• the obtained first calcined product was pulverized in a mortar, and 0.3 g of the pulverized first calcined product obtained was placed in a mold with a diameter of 1.2 cm, and a load of 1 t was applied with a hydraulic press to make a coin. molded into shape.
• the molded product obtained was placed on a platinum plate, heated to 800° C. over 30 minutes, further heated to 1,300° C. over 2 hours, and held for 6 hours to perform main firing. Thereafter, the oxide obtained by cooling to room temperature was pulverized in a mortar to obtain LiZr 2 (PO 4 ) 3 (LZP) powder.
• a polymer solid electrolyte (thickness: 300 ⁇ m) containing polymethyl acrylate (hereinafter also referred to as “pMA”) having a calculated ester group ratio of 51% by mass was obtained.
• pMA polymethyl acrylate
• an ultraviolet integrating photometer UV Power PuckII manufactured by EIT (central wavelength of light receiving part: 355 nm)
• the conversion of MA was >96%.
• all of the above operations except for the measurement of the reaction rate of the vinyl monomer were performed in a dry room with a dew point of -60°C.
• the resulting solid polymer electrolyte membrane had a molar concentration of component (B) of 3.3 mol/kg with respect to 1 kg of electrolyte, and the ionic conductivity of the solid polymer electrolyte was measured to be 1.2 ⁇ 10 ⁇ 7 . S/cm.
• Examples 2 to 15 and Comparative Examples 1 and 2 The same operation as in Example 1 was carried out, except that the curable composition for a solid or gel electrolyte was prepared by changing the types and amounts of the raw materials as shown in Tables 1 and 2, to obtain a polymer solid electrolyte or A polymer gel electrolyte was obtained.
• Tables 1 and 2 show the measurement results of ionic conductivity.
• Example 16 Lithium bis(fluorosulfonyl)imide (28.06 g) as an alkali metal salt and TPO (0.5 g) as a photopolymerization initiator were added to a mixture of MA (10 g) as a vinyl monomer and acetonitrile (3 g) as an organic solvent. was dissolved to obtain a curable composition for a solid electrolyte. However, the organic solvent was blended as a dissolution accelerator for the alkali metal salt, and MA and acetonitrile were dehydrated with molecular sieves. Subsequently, the same operation as in Example 1 was performed to obtain a polymer gel electrolyte. After that, the solid polymer electrolyte was obtained by removing the solvent in the cured product by vacuum drying at 60° C. for 72 hours. Table 1 shows the measurement results of the ionic conductivity.
• Example 17 Lithium bis(fluorosulfonyl)imide (28.06 g) as an alkali metal salt and TPO (0.5 g) as a photopolymerization initiator were added to a mixture of MA (10 g) as a vinyl monomer and acetonitrile (6 g) as an organic solvent. was dissolved to obtain a curable composition for a solid electrolyte. However, the organic solvent was blended as a dissolution accelerator for the alkali metal salt, and MA and acetonitrile were dehydrated with molecular sieves. Subsequently, the same operation as in Example 1 was performed to obtain a polymer gel electrolyte. After that, the solid polymer electrolyte was obtained by removing the solvent in the cured product by vacuum drying at 60° C. for 72 hours. Table 1 shows the measurement results of the ionic conductivity.
• Example 18 Production of solid or gel electrolyte by solution casting method (Method 2) [Example 18] A mixture was prepared by dissolving MA (10 g) as a vinyl monomer and TPO (0.5 g) as a photopolymerization initiator (the ester group ratio of MA calculated by the above formula (2): 51% by mass). . MA used was dehydrated with molecular sieves. Subsequently, a 300 ⁇ m thick silicon rubber sheet having 15 mm square openings was placed on a 20 mm square heavy release type release PET film, the mixture was poured, and a light release type release PET film was placed from above. Laminated.
• the composition sandwiched between the release PET films on both sides is exposed to ultraviolet light with a wavelength of 365 nm (illuminance of 56 mW/cm 2 ) is repeated twice for 30 seconds each from the light release film side and the heavy release film side (6,720 mJ/cm 2 as the integrated light amount), and the cured product is calculated by the above formula (1).
• a pMA having an ester group ratio of 51% by weight was obtained.
• an ultraviolet integrating photometer UV Power PuckII manufactured by EIT (central wavelength of light receiving part: 355 nm) was used. The conversion of MA was >96%.
• pMA obtained above as component (A) and lithium bis(fluorosulfonyl)imide (0.168 g) as an alkali metal salt were dissolved in 0.3 g of N,N-dimethylformamide.
• This composition was dropped onto a release PET film of heavy release type and vacuum dried at 100° C. to remove N,N-dimethylformamide and obtain a polymer solid electrolyte (thickness: 200 ⁇ m).
• all of the above operations except for the measurement of the reaction rate of the vinyl monomer were performed in a dry room with a dew point of -60°C.
• the solid polymer electrolyte membrane obtained had a molar concentration of component (B) of 3.3 mol/kg with respect to 1 kg of electrolyte, and the ion conductivity thereof was measured in the same manner as in Example 1, resulting in a value of 2.8 ⁇ . It was 10 ⁇ 7 S/cm.
• ⁇ MA Methyl acrylate [manufactured by Toagosei Co., Ltd.]
• EA Ethyl acrylate [manufactured by Toagosei Co., Ltd.]
• BA n-butyl acrylate [manufactured by Toagosei Co., Ltd.]
• C-1 2-methoxyethyl acrylate [Acrix (registered trademark) C-1 manufactured by Toagosei Co., Ltd.]
• VAc vinyl acetate [manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.]
• HOA-MS (N) 2-acryloyloxyethyl-succinic acid
• HOA-MS (N) manufactured by Kyoeisha Chemical Co., Ltd.]
• BMA n-butyl methacrylate [manufactured by FUJ
• the negative electrode mixture slurry was applied to one side of a copper foil (thickness: 16.5 ⁇ m) and dried to form a mixture layer. Then, after rolling so that the thickness of the mixture layer per one side was 50 ⁇ 5 ⁇ m and the mixture density was 1.60 ⁇ 0.10 g/cm 3 , a 3 cm square was punched out to obtain a negative electrode plate.
• NMP N-methylpyrrolidone
• NMC532 LiNi 0.5 Mn 0.3 Co 0.2 O 2
• acetylene black as a carbon conductive agent
• PVDF polyfluoride having an average molecular weight of 1,100,000 Vinylidene
• the prepared slurry was applied to one side of an aluminum foil (thickness: 20 ⁇ m), dried, rolled so that the thickness of the material mixture layer per side was 125 ⁇ m, and the packing density was 3 g/cm 3 .
• a positive electrode plate was obtained.
• the configuration of the battery is such that a lead terminal is attached to each of the positive electrode and the negative electrode, and a separator (made of polyethylene: film thickness 20 ⁇ m, porosity 48%, manufactured by Shenzhen Senior Technology Material Co., Ltd., China) is placed between both electrodes.
• the mixture layer of is sandwiched toward the separator side, put in a battery outer body using an aluminum laminate, and the curable composition for a solid electrolyte prepared in Example 12 is injected, and after sealing by heat sealing. , and allowed to stand at 25° C. for 24 hours to promote penetration of the curable composition into the electrode. After that, it was left in a constant temperature bath at 60° C. for 48 hours to polymerize the component (a) to obtain a test battery (pouch type battery). The design capacity of this battery is 49 mAh. The design capacity of the battery was designed based on the final charging voltage up to 4.2V.
• ⁇ Charging and discharging test> The prepared pouch-type battery was set in a constant temperature bath at 45° C., and a charge/discharge test (charge/discharge tester VMP-3 manufactured by BioLogic) was performed. At the first time, CC charging is performed at 0.49mA, which corresponds to a rate of 0.01C for 49mAh. After reaching 4.2V, switch to CV charging. When the current value drops to 0.1mA, stop charging and leave for 48 hours. and stimulated SEI formation. After that, the battery was discharged at 0.01C to a final voltage of 2.5V.
• the capacity was set to 40 mAh in consideration of the irreversible capacity, and charging/discharging was performed at a current value of 0.4 mA (equivalent to 0.01 C) during constant current charging/discharging.
• CC charging was performed to 4.2 V
• charging was switched to CV charging, and charging was stopped when the current value decreased to 0.1 mA.
• discharge was performed at 0.01C with a final voltage of 2.5V.
• the ester group ratio of the component (A) is less than 32% by mass, the component (B) cannot be dissolved at a molar concentration of 2.8 mol/kg or more with respect to 1 kg of the electrolyte, and the electrolyte cannot be obtained.
• the molar concentration of the component (B) with respect to 1 kg of the electrolyte is less than 2.8 mol/kg (Comparative Example 2), the ionic conductivity at 30°C is lower than in Examples 1 to 14, resulting in poor practicality. Met.

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