Electrolyte composition and battery

Abstract

To provide a polymer with excellent voltage resistance on the oxidation side.SOLUTION: A polymer comprises a specific N-substituted maleimide structural unit (A) and a second structural unit. The ratio (m) of the structural unit (A) to all the structural units included in the polymer is 0.2-0.8, and the ratio (n) of the second structural unit is 0.2-0.8.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a polymer, a method for producing the polymer, an electrolyte composition, and a battery.

Background Art

[0002] Lithium ion batteries and the like are being actively studied because of their high capacity. As electrolytes for lithium ion batteries, solutions of lithium salts containing organic solvents or ionic liquids are known. However, research on solid electrolytes has been advanced from the viewpoints of safety and processability. Among them, polymers containing lithium ions have attracted attention for the following reasons (Patent Document 1, and Non-Patent Documents 1 and 2).

[0003] That is, polymers containing lithium ions have the advantage of being highly flexible and thus easily making contact within the solid electrolyte and at the interface with the electrode. In addition, by using the counter anion of lithium ions as a functional group of the polymer, the anion can be fixed to the polymer, suppressing the movement of ions other than lithium ions during charge and discharge, and substantially making only lithium ions a charge carrier (that is, it can be used as a single ion conductor (SIC)).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Documents

[0005]

Non-Patent Document 1

[0006] However, the polymers containing lithium ions in Patent Document 1 and Non-Patent Documents 1 and 2 have an oxidation potential of about 4.4 V, and there is room for improvement in the oxidation-side voltage resistance. In order to be combined with electrodes at higher potentials, the development of polymers with better oxidation-side voltage resistance is desired.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a polymer having excellent oxidation-side voltage resistance. Another object of the present invention is to provide a method for producing a polymer having excellent oxidation-side voltage resistance. Furthermore, an object of the present invention is also to provide an electrolyte composition and a battery containing such a polymer. 0[Means for Solving the Problems]

[0008] The polymer of the present invention includes a first structural unit that is at least one of structural units (A) represented by the following formula (A), and a second structural unit that is at least one of a structural unit (B1) represented by the following formula (B1) and a structural unit (B2) represented by the following formula (B2), and satisfies at least one of the following conditions (1) and (2). (1) The ratio m of the first structural unit to all the structural units contained in the polymer is 0.2 to 0.8, and the ratio n of the second structural unit to all the structural units contained in the polymer is 0.2 to 0.8. (2) The content of the first structural unit is 25 to 95% by mass, and the content of the second structural unit is 5 to 75% by mass with respect to the total mass of the polymer.

Chemical formula

Chemical formula

Chemical formula

[0009] It is preferable that the molar ratio of the structural unit (C) represented by the following formula (C) to the first structural unit in the polymer is 5 / 95 or less.)

Chemical formula

[0010] The oxidation potential of the polymer is preferably 4.5 V or more based on the Li / Li + electrode as a reference.)

[0011] It is preferable that the second structural unit contains the structural unit (D) represented by the following formula (D).)

Chemical formula

[0012] It is preferable that the molar ratio of the structural unit (A) to the total number of moles of the structural unit (A) and the structural unit (B1) is greater than 0.40.)

[0013] The polymer of the present invention is a polymer containing the structural unit (A) represented by the following formula (A), and the molar ratio of the structural unit (C) represented by the following formula (C) to the structural unit (A) in the polymer may be 5 / 95 or less.)

Chemical formula

Chemical formula

[0014] The electrolyte composition of the present invention contains the above polymer.

[0015] Preferably, the above electrolyte composition further contains a plasticizer.

[0016] Preferably, the above plasticizer is an organic solvent.

[0017] The battery of the present invention contains the above polymer or the above electrolyte composition.

[0018] The method for producing the polymer of the present invention includes a step of polymerizing a monomer containing a monomer (A') represented by the following formula (A') and at least one second monomer selected from a monomer (B1') represented by the following formula (B1') and a monomer (B2') represented by the following formula (B2').

Chemical formula

Chemical formula

Chemical formula

[0019] The polymer of the present invention may be obtained by polymerizing a monomer containing a monomer (A’) represented by the following formula (A’) and at least one second monomer selected from a monomer (B1’) represented by the following formula (B1’) and a monomer (B2’) represented by the following formula (B2’). [Chemical formula] (In formula (A’), X is a divalent organic group having 1 to 20 carbon atoms, Y is a halogen atom or a monovalent organic group having 1 to 20 carbon atoms, and M is an alkali metal element selected from Li, Na, and K.) [Chemical formula] (In formula (B1’), R 1 ~R 4 are each independently a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms.) [Chemical formula] (In formula (B2’), R 15 is a divalent organic group having 1 to 20 carbon atoms, and R 16 and R 17 are each a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms. However, the monomer (B2’) does not include maleic anhydride and the monomers included in the above monomer (A’).) [Advantages of the Invention]

[0020] According to the present invention, a polymer excellent in oxidation-side withstand voltage can be provided. Further, according to the present invention, a method for producing a polymer excellent in oxidation-side withstand voltage can also be provided. Furthermore, according to the present invention, an electrolyte composition and a battery containing such a polymer can be provided.

Embodiments for Carrying Out the Invention

[0021] (First Embodiment)

[0022] A polymer comprising a first structural unit which is a structural unit (A) represented by the following formula (A) and a second structural unit which is at least one of a structural unit (B1) represented by the following formula (B1) and a structural unit (B2) represented by the following formula (B2), the polymer satisfying at least one of the following conditions (1) and (2). (1) The ratio m of the first structural unit to all the structural units contained in the polymer is 0.2 to 0.8, and the ratio n of the second structural unit to all the structural units contained in the polymer is 0.2 to 0.8. (2) The content of the first structural unit is 25 to 95% by mass, and the content of the second structural unit is 5 to 75% by mass with respect to the total mass of the polymer.

Chemical formula

Chemical formula

Chemical formula

[0023] m is preferably 0.3 to 0.7, more preferably 0.4 to 0.6. n is preferably 0.3 to 0.7, more preferably 0.35 to 0.65.

[0024] The value of m / (m + n) is preferably greater than 0.40, more preferably 0.41 or more, still more preferably 0.45 or more, and particularly preferably 0.45 to 0.65.

[0025] The sum of m and n may be 1 or less, for example, it may be 0.5 to 0.95, or it may be 0.6 to 0.90.

[0026] The content of the structural unit (A) with respect to the total mass of the polymer may be 40 to 90% by mass, or may be 50 to 90% by mass. The content of the second structural unit with respect to the total mass of the polymer may be 10 to 60% by mass, or may be 10 to 50% by mass. The total content of the structural unit (A) and the second structural unit with respect to the total mass of the polymer may be 90% by mass or more, may be 95% by mass, or may be 98% by mass or more.

[0027] The content of structural unit (B1) relative to the total mass of the polymer may be 10 to 60% by mass, and may be 10 to 50% by mass. The total content of structural unit (A) and structural unit (B1) relative to the total mass of the polymer may be 90% by mass or more, may be 95% by mass, and may be 98% by mass or more.

[0028] In the polymer, the molar ratio of structural unit (A) to the total number of moles of structural unit (A) and structural unit (B1) is preferably greater than 0.40, more preferably 0.41 or more, still more preferably 0.45 or more, and particularly preferably 0.45 to 0.65.

[0029] X is not particularly limited, and may be a hydrocarbon group or a group having a heteroatom, and may have a heterocyclic ring. More specifically, as X, there may be mentioned divalent groups such as a hydrocarbon group, and a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted by a linking group such as -O-, -S-, -C(=O)- or -C(=O)O-. When there are a plurality of linking groups, the linking groups are not adjacent to each other. Further, the above divalent group may have a substituent that substitutes a hydrogen atom bonded to a carbon atom. The substituent may be a monovalent substituent, and examples thereof include a halogen atom. The hydrocarbon group is not particularly limited, and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. Further, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. X may be bonded to one or both of the nitrogen atom of the two maleimide groups and the sulfur atom of the sulfonyl group by the carbon atom that X has.

[0030] In the present specification, an aromatic hydrocarbon group is a group containing an aromatic moiety, and may have an aliphatic moiety. Also, in the present specification, a cyclic hydrocarbon group is a group containing a cyclic hydrocarbon moiety, and may contain a linear or branched hydrocarbon moiety.

[0031] The number of carbon atoms that X may have may be 1 to 15, may be 2 to 10, or may be 3 to 8. X may be a group having an aromatic ring, and may be a group having an aromatic carbocyclic ring such as a benzene ring. Substituents such as an alkyl group, a halogen atom, and an electron-withdrawing group may be bonded to the carbon atoms that are ring members of the carbocyclic ring. The hydrocarbon group as X is preferably a phenylene group, an alkylene group having 1 to 8 carbon atoms, a polyoxyalkylene group, or a group in which some or all of the hydrogen atoms bonded to the carbon atoms they have are substituted with halogen atoms such as fluorine atoms, and more preferably a phenylene group or a substituted phenylene group substituted with an alkyl group, a halogen atom, an electron-withdrawing group, etc. Examples of the electron-withdrawing group include a halogen atom, a sulfonic acid group or its salt, a sulfonic acid ester, a nitro group, and a nitrile group.

[0032] In formula (A), when Y is a monovalent organic group, the organic group is not particularly limited and may be a hydrocarbon group or a group having a heteroatom, and may have a heterocyclic ring. More specifically, examples of Y include a monovalent group such as a hydrocarbon group and a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted by a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-. When there are a plurality of linking groups, the linking groups are not adjacent to each other. Further, the above monovalent group may have a substituent that substitutes the hydrogen atom bonded to the carbon atom. The substituent may be a monovalent substituent, and examples thereof include a halogen atom. The hydrocarbon group is not particularly limited and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. Further, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group.

[0033] The number of carbon atoms that Y may have may be 1 to 15, may be 1 to 10, may be 1 to 8, may be 1 to 5, or may be 1 to 3. The hydrocarbon group as Y is preferably a phenyl group, an alkyl group having 1 to 5 carbon atoms, or a group in which some or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with halogen atoms such as fluorine atoms, more preferably a fluorinated alkyl group having 1 to 5 carbon atoms, and even more preferably a fluorinated alkyl group having 1 to 3 carbon atoms such as a trifluoromethyl group. The fluorinated alkyl group may be a perfluorinated alkyl group. When Y is a halogen atom, the halogen atom is preferably a fluorine atom or a chlorine atom, and more preferably a fluorine atom.

[0034] In formula (A), M + is an alkali metal ion, preferably a lithium ion (Li + ), a sodium ion (Na + ), or a potassium ion (K + ), and more preferably a lithium ion. M + is Li + , Na + , and K + and may contain two or three of these ions, but preferably contains substantially only a single ion.

[0035] In formula (B1), R 1 ~R 4 may be the same as or different from each other. When at least one of R 1 ~R 4 is a monovalent organic group, the organic group is not particularly limited and may be a hydrocarbon group or a group having a heteroatom, and may have a heterocyclic ring. R 1 ~R 4Specifically, examples of the monovalent group include a hydrocarbon group and a group having a chemical structure in which one or more carbon atoms (methylene groups) in the hydrocarbon group are substituted with a linking group such as -O-, -S-, -C(=O)-, or -C(=O)O-. When there are a plurality of linking groups, the linking groups are not adjacent to each other. Further, the monovalent group may have a substituent that substitutes a hydrogen atom bonded to a carbon atom. Examples of the substituent include a halogen atom. The hydrocarbon group is not particularly limited and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. Further, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group.

[0036] R 1 ~R 4 Among them, it is preferable that at least one is a hydrogen atom, more preferably two or more are hydrogen atoms, and most preferably three are hydrogen atoms. R 1 ~R 4 When at least one of them is a halogen atom, the halogen atom is preferably a chlorine atom or a fluorine atom, and more preferably a fluorine atom.

[0037] Examples of the monovalent organic group include a group represented by the formula: -Z-R. Here, Z is a covalent bond, -O-, -S-, -C(=O)-, or -C(=O)O-, and R is a monovalent organic group. Among R 1 ~R 4 at least one may be a group represented by -Z-R. When Z is other than a covalent bond, R is a group bonded to Z by a carbon atom that R has, and when Z is a covalent bond, R is a group directly bonded to the carbon atom of the ethylene moiety in formula (B1) by a carbon atom that R has.

[0038] The number of carbon atoms that R has is preferably 1 to 18, more preferably 2 to 15, and even more preferably 3 to 13.

[0039] R is a substituted or unsubstituted hydrocarbon group, or a formula: -(R24 O) k -R 25 It may be a group represented by. Examples of the hydrocarbon group include linear or branched alkyl groups, cyclohexyl groups, groups having a carbocyclic ring such as a benzyl group (either aliphatic or aromatic is acceptable). Examples of the substituted hydrocarbon group include those in which some or all of the hydrogen atoms of the above hydrocarbon group are replaced by halogen atoms (a fluorine atom is preferred).

[0040] In the formula, k may be 1 to 6, may be 1 to 5, and may be 1 to 4. R 24 may be a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, and may be an ethylene group. When there are a plurality of R 24 s, R 24 s may all be the same or may be two or more kinds of alkylene groups. When R 24 is a substituted alkylene group, R 24 is preferably one in which the hydrogen atoms of the alkylene group exemplified when R 24 is an alkylene group are substituted by a substituent. The substituent may be a halogen atom such as a fluorine atom.

[0041] R 25 may be a substituted or unsubstituted hydrocarbon group having 1 to 6 carbon atoms, may be a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, may be a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, may be a substituted or unsubstituted ethyl group or a substituted or unsubstituted methyl group. When R 25 is a substituted hydrocarbon group, R 25 is preferably one in which the hydrogen atoms of the hydrocarbon group exemplified when R 25 is a hydrocarbon group are substituted by a substituent. The substituent may be a halogen atom such as a fluorine atom.

[0042] When R is a hydrocarbon group, the hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group may be used. Further, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. Specifically, examples of R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, a phenyl group, a benzyl group, and the like. When R is a substituted hydrocarbon group, R is preferably a group in which a hydrogen atom of the hydrocarbon group exemplified when R is a hydrocarbon group is substituted with a substituent. The substituent may be a halogen atom such as a fluorine atom.

[0043] It is preferable that the structural unit (B1) contains a structural unit (D) represented by the following formula (D).

Chemical formula

[0044] R 22 When is a monovalent hydrocarbon group, the number of carbon atoms possessed by the hydrocarbon group is preferably 1 to 10, preferably 1 to 5, and more preferably 1 to 3. R 22 may be a hydrogen atom or a methyl group.

[0045] Z is preferably a covalent bond, -O-, -C(=O)O- or -OC(=O)-, more preferably a covalent bond or -O-, and even more preferably -O-.

[0046] R 21It is preferable that it is exemplified as R of the above -Z-R group.

[0047] The structural unit (B1) may contain structural units other than the structural unit (D). Examples of such structural units include, for example, the structural unit (E) represented by the following formula (E).

Chemical formula

[0048] When R 31 is an organic group, R 31 is preferably a substituted or unsubstituted hydrocarbon group. The number of carbon atoms of the substituted or unsubstituted hydrocarbon group is preferably 1 to 18, more preferably 1 to 15, still more preferably 1 to 10, and particularly preferably 1 to 5.

[0049] In addition, the polymer may contain a structural unit (B2) represented by the following formula (B2).

Chemical formula

[0050] The number of carbon atoms contained in R 15 is preferably 2 to 10, more preferably 2 to 6, and still more preferably 3 to 5. R 15It may contain at least one divalent group selected from the group consisting of -O-, -S-, -C(=O)-, -C(=O)O-, -C(=O)-O-C(=O)-, and -C(=O)-N(R 35 )-C(=O)- in the base. Here, R 35 is a monovalent organic group. When R 15 contains a plurality of such divalent groups, the plurality of divalent groups are not adjacent to each other. Also, R 15 may have a hydrocarbon moiety or a substituted hydrocarbon moiety in which a hydrogen atom of the hydrocarbon moiety is substituted with a substituent in addition to the above divalent group. Examples of the substituent include a halogen atom and the like. The hydrocarbon group is not particularly limited and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be any of a linear hydrocarbon group, a branched hydrocarbon group, and a cyclic hydrocarbon group. Also, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group.

[0051] R 15 may have 1 to 15 carbon atoms, may have 2 to 10 carbon atoms, may have 2 to 8 carbon atoms, or may have 3 to 6 carbon atoms. The hydrocarbon group as R 15 is preferably an alkylene group having 1 to 8 carbon atoms, a polyalkyleneoxy group, or a group in which some or all of the hydrogen atoms bonded to the carbon atoms they have are substituted with a halogen atom such as a fluorine atom.

[0052] R 16 and R 17 When they are organic groups, specific examples of the organic group include those exemplified as specific examples of R 1 ~R 4 .

[0053] The structural unit (B2) is a group different from the structural unit (A). That is, the structural units contained in the above structural unit (A) are not contained in the structural unit (B2). When R 15 is a -C(=O)-N(R 35 )-C(=O)- group, R 35 is -X-SO2-N -M + -SO2-Y (X, M, and Y have the same meanings as X, M, and Y in formula (A).), but in that case, R 16 and R 17 at least one of them is a monovalent substituent other than a hydrogen atom, and examples of such a substituent include a halogen atom, a monovalent organic group having 1 to 20 carbon atoms, etc. The number of carbon atoms of the monovalent organic group is preferably 1 to 10, and more preferably 1 to 5.

[0054] The structural unit (B2) is a group different from the structural unit (C) described later. In the structural unit (B2), R 15 is -C(=O)-O-C(=O)- and R 16 and R 17 does not include a structural unit in which both are hydrogen atoms. That is, when R 15 is -C(=O)-O-C(=O)-, at least one of R 16 and R 17 is a monovalent substituent other than a hydrogen atom, and examples of such a substituent include a halogen atom, a monovalent organic group having 1 to 20 carbon atoms, etc. The number of carbon atoms of the monovalent organic group is preferably 1 to 10, and more preferably 1 to 5.

[0055] R 15 may be a group having 3 to 21 carbon atoms containing at least one of -C(=O)-O-C(=O)- and -C(=O)-N(R 35 )-C(=O)-, -C(=O)-O-C(=O)-, and -C(=O)-N(R 35)-C(=O)- may be a group having 3 to 19 carbon atoms and containing at least one of them. Examples of such groups include structural units derived from maleic anhydride derivatives, structural units derived from maleimide derivatives, and the like. The structural unit (B2) may contain at least one of a structural unit derived from a maleic anhydride derivative and a structural unit derived from a maleimide derivative. Note that the structural unit derived from a maleic anhydride derivative and the structural unit derived from a maleimide derivative are structural units having a chemical structure directly obtained when the maleic anhydride derivative and the maleimide derivative are radically polymerized. The molar ratio of the structural unit derived from the maleic anhydride derivative to the first structural unit may be 5 / 95 or less.

[0056] R 35 is a monovalent organic group. The number of carbon atoms in the monovalent organic group may be 1 to 15, may be 2 to 10, may be 2 to 8, or may be 3 to 6.

[0057] R 15 When R is an organic group, R 15 may be a substituted or unsubstituted hydrocarbon group. The number of carbon atoms in the substituted or unsubstituted hydrocarbon group is preferably 1 to 18, more preferably 1 to 15, and still more preferably 1 to 10.

[0058] The polymer may contain a structural unit derived from a hydrocarbon compound having a plurality of ethylenically unsaturated groups such as butadiene and isoprene.

[0059] The polymer may have a structural unit derived from a crosslinking agent. Examples of the crosslinking agent include compounds having a plurality of ethylenically unsaturated groups in the molecule such as hexanediol diacrylate, pentaerythritol tetraacrylate, divinylbenzene, and triethylene glycol divinyl ether.

[0060] The above polymer may contain two or more structural units (A), or may contain only one type of structural unit (A). Further, the above polymer may contain two or more second structural units, or may contain only one type of second structural unit. When containing a plurality of second structural units, either one or both of the structural unit (B1) and the structural unit (B2) may be contained in a plurality of types, or the structural unit (B1) and the structural unit (B2) may each be contained one by one.

[0061] The number average molecular weight (Mn) of the polymer may be 5,000 to 200,000, may be 8,000 to 120,000, or may be 10,000 to 100,000. The weight average molecular weight (Mw) of the polymer may be 5,000 to 300,000, may be 10,000 to 250,000, or may be 20,000 to 100,000. The molecular weight distribution (Mw / Mn) of the polymer may be 1.0 to 3.0, or may be 1.3 to 2.7. The number average molecular weight and the weight average molecular weight of the polymer can be measured, for example, by gel permeation chromatography.

[0062] The above polymer may or may not contain a structural unit (C) represented by the following formula (C).

Chemical formula

[0063] The content of the structural unit (C) in the polymer is preferably 5 / 95 or less, more preferably 3 / 97 or less, and still more preferably 1 / 99 or less in terms of the molar ratio of the structural unit (C) to the structural unit (A). When the content of the structural unit (C) in the polymer is within such a range, the oxidation-side breakdown voltage resistance of the polymer tends to be higher. The polymer may not substantially contain the structural unit (C). Further, the polymer may contain a structural unit generated by the reaction of one or two molecules of water with the structural unit (A) or a structural unit generated by the hydrolysis of (C).

[0064] <Method for producing polymer> The method for producing a polymer according to an embodiment of the present invention preferably includes a step of polymerizing a monomer (monomer mixture) containing a monomer (also referred to as a first monomer) represented by the following formula (A') and a second monomer containing at least one of a monomer (B1') represented by the following formula (B1') and a monomer (B2') represented by the following formula (B2'). Such a method for producing a polymer is a method suitable for producing the polymer of the present embodiment. Note that the second monomer may be used in excess of a desired ratio in the polymer.

Chemical formula

Chemical formula

[0065] Preferred examples of X, Y, and M in the monomer (A') are the same as those exemplified as X, Y, and M in the structural unit (A) of the above polymer, respectively.

[0066] Preferred examples of R 1 ~R 4 in the monomer (B1') are the same as those exemplified as R 1 ~R 4Examples thereof include those exemplified as such. That is, examples of the monomer (B1) include the monomer (D') represented by the following formula (D'), the monomer (E') represented by the following formula (E'), and the like.

Chemical formula

[0067] In formula (D'), R 22 , Z and R 21 Preferred examples of are those exemplified as R 22 , Z and R 21 in structural unit (D). In formula (E'), preferred examples of R 11 ~R 14 are those exemplified as R 11 " ~R 14 in structural unit (E).

[0068] In formula (E'), preferred examples of R 15 ~R 17 are those exemplified as R 15 ~R 17 in structural unit (B2). The monomer (B2') does not contain either maleic anhydride or any of the monomers contained in the monomer (A').

[0069] The monomer (B1') may be an alkyl (meth)acrylate, an olefin compound, styrene or a styrene derivative, a vinyl ester compound, or a vinyl ether compound, with an olefin compound or a vinyl ether compound being preferred. Examples of the vinyl ether compound include compounds given by H2C=CH(OR 41 ), and R 41 may be a substituted or unsubstituted hydrocarbon group, or a group of the above formula: -(R 24 O) k -R 25 . Examples of R 41 include those exemplified as the above R.

[0070] The vinyl ether compound may be an alkyl vinyl ether. Examples of the vinyl ether compound include alkyl vinyl ethers having a linear or branched alkyl group such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-heptyl vinyl ether, n-octyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, n-decyl vinyl ether, n-undecyl vinyl ether, n-dodecyl vinyl ether, n-tridecyl vinyl ether, etc.; vinyl ether compounds having a carbocyclic ring (which may be either aliphatic or aromatic) such as cyclohexyl vinyl ether and benzyl vinyl ether, etc. Isobutyl vinyl ether or n-dodecyl vinyl ether is preferred.

[0071] Further, the vinyl ether compound may be a compound having two or more ether bonds in the molecule such as tetraethylene glycol methyl vinyl ether, 3,6,9,12,15-pentaoxa-1-heptadecene and 2-(heptafluoropropoxy)hexafluoropropyl trifluorovinyl ether.

[0072] Examples of the styrene derivative include alkyl-substituted styrenes. The alkyl group as a substituent may be a methyl group or an ethyl group. Examples of the alkyl-substituted styrene of styrene include α-methylstyrene, β-methylstyrene (which may be either cis-type, trans-type, or a mixture thereof), 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, etc. Further, examples of the styrene derivative also include alkoxystyrenes such as 4-methoxystyrene and 4-ethoxystyrene; halogen-substituted styrenes such as 2,3,4,5,6-pentafluorostyrene, etc.

[0073] The coincidence composition contains a monomer (A') and a second monomer, and a radical polymerization initiator. That is, the polymerization reaction of the monomer is carried out in the polymerizable composition and initiated in the presence of an initiator. When the molar number of the monomer (A') relative to the total molar number of all monomers contained in the polymer composition is m, m is preferably 0.3 to 0.7, more preferably 0.4 to 0.6. When the molar number of the monomer (B1') relative to the total molar number of all monomers contained in the polymer composition is n, n is preferably 0.3 to 0.7, more preferably 0.4 to 0.6.

[0074] The value of m / (m + n) in the polymerizable composition is preferably greater than 0.40, more preferably 0.41 or more, still more preferably 0.45 or more, and particularly preferably 0.45 to 0.60. The sum of m and n in the polymerizable composition may be 1 or less, for example, it may be 0.5 to 0.95, or it may be 0.6 to 0.90. When the monomer (A') and the second monomer are in the relationship of an electron acceptor and an electron donor, the polymer tends to have a primary structure in which the structural unit (A) and the second structural unit are arranged alternately.

[0075] The radical polymerization initiator may be either a thermal initiator or a photoinitiator. For example, as the thermal initiator, azo-based initiators such as 2,2-azobis(isobutyronitrile) (AIBN); 2,2-azobis(2-methylbutyronitrile) (AMBN), 2,2-azobis(2,4-dimethylvaleronitrile) (ADVN), 1,1-azobis(1-cyclohexanecarbonitrile) (ACHN, V-40), dimethyl-2,2-azobisisobutyrate (MAIB); organic peroxides such as dibenzoyl peroxide, di-8,5,5-trimethylhexanoyl peroxide, dilauroyl peroxide, didecanoyl peroxide, di(2,4-dichlorobenzoyl) peroxide, etc. can be mentioned. As the photoinitiator, oxime-based compounds, metallocene-based compounds, acylphosphine-based compounds, aminoacetophenone compounds, etc. can be mentioned. One or more initiators may be used.

[0076] The coincidence composition may contain a chain transfer agent such as carbon tetrachloride.

[0077] If necessary, the polymerizable composition may contain a crosslinking agent. Further, the polymerizable composition may contain a solvent. Further, the polymerizable composition does not have to contain maleic anhydride, and the molar ratio of maleic anhydride to monomer (A) is 5 / 95 or less, more preferably 3 / 97 or less, and even more preferably 1 / 99 or less.

[0078] (Second Embodiment) The polymer according to the second embodiment of the present invention contains a structural unit (A) represented by the following formula (A), and the molar ratio of the structural unit (C) represented by the following formula (C) to the structural unit (A) in the polymer is 5 / 95 or less. Such a polymer is excellent in oxidation-side breakdown voltage resistance.

Chemical formula

Chemical formula

[0079] The polymer according to the second embodiment may be a copolymer containing the structural unit (A) and a structural unit other than the structural unit (A) as structural units. The copolymer may contain the structural unit (A) as a main component. The polymer does not have to contain the structural unit (C), and the molar ratio of the structural unit (C) to the structural unit (A) is 5 / 95 or less, more preferably 3 / 97 or less, and even more preferably 1 / 99 or less. When the content of the structural unit (C) in the polymer is within such a range, the oxidation stability of the polymer tends to be high.

[0080] The proportion m of structural unit (A) to all the structural units contained in the polymer may be 0.2 to 0.95, may be 0.2 to 0.8, preferably m is 0.3 to 0.7, and more preferably 0.4 to 0.6. n is preferably 0.3 to 0.7, and more preferably 0.4 to 0.6.

[0081] Preferable examples of the structural unit (A) may be those exemplified as the structural unit (A) in the polymer of the first embodiment.

[0082] The polymer of this embodiment may contain structural units other than the structural unit (A). Such structural units are preferably structural units obtained by radical polymerization of monomers having ethylenically unsaturated groups, may be the second structural unit in the polymer of the first embodiment, and may be at least one of the structural unit (B1) and the structural unit (B2). The types of the structural unit (B1) and the structural unit (B2), and the range of the content of the structural unit (B1) and the structural unit (B2) can be the same as those in the first embodiment. Further, the polymer according to this embodiment may contain a structural unit derived from a crosslinking agent, and may contain a structural unit generated by the reaction of one or two molecules of the structural unit (A) with water, or a structural unit generated by the hydrolysis of the structural unit (C). The molar ratio of the structural unit derived from the maleic anhydride derivative to the first structural unit may be 5 / 95 or less. The structural unit derived from maleic anhydride is a structural unit having a chemical structure directly obtained when a maleic anhydride derivative is radically polymerized.

[0083] The method for producing the polymer of this embodiment preferably includes a step of polymerizing a monomer (monomer mixture) containing a monomer (A') represented by the formula (A'). Such a method for producing a polymer is a method suitable for producing the polymer of the above-described embodiment. The polymerization of the monomer may be carried out in a polymerizable composition containing an initiator.

[0084] Since the polymers of the first and second embodiments tend to have high ionic conductivity (alkali metal ionic conductivity), they may be included in a battery as an ion conductive material. The polymer of this embodiment can be used, for example, as an electrolyte for batteries such as lithium ion batteries, sodium ion batteries, potassium ion batteries, etc., or as an electrolyte for capacitors. The oxidation potential of the polymers of the first and second embodiments is preferably 4.5 V or more, more preferably 4.6 V or more, and particularly preferably 4.8 V or more based on the Li / Li + electrode.

[0085] The polymers of the first and second embodiments may be mixed with a plasticizer to form an electrolyte composition for use in an electrolyte of a battery or the like. That is, the electrolyte composition of this embodiment may contain the polymer of the first or second embodiment and may further contain a plasticizer. The plasticizer may be an organic solvent and may be an aprotic solvent. The organic solvent may be at least one selected from the group consisting of carbonate solvents, fluorine solvents, and ether solvents, and these solvents may also be aprotic solvents. Using a plasticizer tends to make the electrolyte composition easier to mold.

[0086] Examples of carbonate solvents include chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate; and cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, and vinylene carbonate. Examples of ether solvents include cyclic ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, and 1,3-dioxolane; and chain ethers such as 1,2-diethoxyethane and ethoxymethoxyethane. Examples of fluorine solvents include hydrofluorocarbons such as perfluorooctane; hydrofluoroethers such as methyl nonafluorobutyl ether and ethyl nonafluorobutyl ether; and hydrofluoroolefins such as 1,3,3,3-tetrafluoropropene. In addition, examples of solvents include aprotic solvents such as dimethyl sulfoxide (DMSO); and amide solvents such as dimethylformamide (DMF) and dimethylacetamide (DMA).

[0087] The content of the plasticizer in the electrolyte composition may be 20 to 500 parts by mass, may be 50 to 300 parts by mass, or may be 100 to 250 parts by mass with respect to 100 parts by mass of the above polymer.

[0088] The electrolyte composition may further contain other resins. Examples of other resins include fluorine-based resins. As the fluorine-based resin, a resin having a carbon chain as the main chain is preferable. The carbon chain may be formed by radical polymerization of an ethylenically unsaturated group. Examples of the fluorine resin include poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and polyvinylidene fluoride (PVDF).

[0089] The electrolyte composition may contain a lithium salt in addition to the above polymer. The lithium salt is not particularly limited, and examples thereof include LiCl, LiBr, LiI, LiClO4, LiPF6, LiBF4, Li2SO4, Li[(C h F 2h+1 )SO2]2N (h is 0 to 3).

Examples

[0090] <Production of Polymer> The following monomers A1, B1, B2, B3 and B4 were prepared.

[0091] (Synthesis of Monomer A1) Under a nitrogen atmosphere, trifluoromethanesulfonamide (52.5 mmol, 7.83 g, manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in dehydrated acetonitrile (150 mL, manufactured by Kanto Chemical Co., Inc.). Lithium hydroxide (105 mmol, 2.51 g, manufactured by Tokyo Chemical Industry Co., Ltd.) and 4-acetamidobenzenesulfonyl chloride (50 mmol, 11.68 g, manufactured by Tokyo Chemical Industry Co., Ltd.) were sequentially added to this solution, and the mixture was heated under reflux for 5 hours. After cooling to room temperature, an excess amount of acetonitrile (700 mL) was added to precipitate a solid, which was separated by filtration and then washed with dichloromethane (manufactured by Kanto Chemical Co., Inc.) to obtain Intermediate 1. The yield was 97.1%. ·Structural formula of Intermediate 1: [Chemical formula]

[0092] Under a nitrogen atmosphere, 5% hydrochloric acid (22.5 mL) was added to Intermediate 1 (15 mmol, 5.28 g), and the mixture was stirred at 90 °C for 2 hours. After cooling to room temperature, an aqueous lithium hydroxide solution was added until the pH reached 7 or higher as confirmed by pH test paper etc., and then a solid was obtained by drying under reduced pressure. The obtained solid was extracted with an acetonitrile solution and dried under reduced pressure to obtain Intermediate 2. The yield was 92.6% based on the raw material of Intermediate 1 above. ·Structural formula of Intermediate 2: [Chemical formula]

[0093] Under a nitrogen atmosphere, maleic anhydride (13.3 mmol, 1.30 g, manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in dehydrated 1,4-dioxane (manufactured by Kanto Chemical Co., Inc.). To this solution, a solution of intermediate 2 (13.2 mmol, 4.09 g) in dehydrated tetrahydrofuran (26.4 mL, manufactured by Kanto Chemical Co., Inc.), which was prepared under a nitrogen atmosphere, was added dropwise in its entirety, and the mixture was stirred at room temperature for 12 hours. After the reaction, the precipitate was filtered and vacuum dried at 60 °C for 4 hours to obtain a solid containing intermediate 3. · Structural formula of intermediate 3:

Chem.

[0094] Under a nitrogen atmosphere, a solid containing intermediate 3 (14.0 mmol, 5.70 g) and an aqueous sodium acetate solution (13.3 mmol, 1.09 g, manufactured by Tokyo Chemical Industry Co., Ltd.) were added to acetic anhydride (12.3 mL, manufactured by Tokyo Chemical Industry Co., Ltd.), and the mixture was stirred at 70 °C for 3 hours. The solution after the reaction was added dropwise in its entirety to an excess amount of diethyl ether (manufactured by Kanto Chemical Co., Inc.) at 0 °C, and the precipitate was collected by filtration. Under an inert atmosphere, the precipitate was extracted with dehydrated acetonitrile (manufactured by Kanto Chemical Co., Inc.) and dried under reduced pressure to obtain A1. The yield through all steps was 72.8%. · Monomer A1: The following compound (A1)

Chem.

[0095] B1: A commercially available reagent manufactured by Tokyo Chemical Industry Co., Ltd. with a purity > 99% was washed with 10% NaOHaq. and pure water, dried overnight with KOH in a sealed container, and then used after improving the purity by adding CaH2 and performing atmospheric distillation. B2: A commercially available reagent manufactured by Aldrich with a purity > 98% was dried overnight with CaCl2 in a sealed container, and then used after improving the purity by adding CaH2 and performing distillation under reduced pressure. B3: A commercially available reagent manufactured by Aldrich with a purity > 98% was used as it was. B4: A commercially available reagent manufactured by Aldrich with a purity > 98% was dried overnight with CaCl2 in a sealed container, and then used after improving the purity by adding CaH2 and performing distillation under reduced pressure.

[0096] Monomer B1: Isobutyl vinyl ether Monomer B2: n-Dodecyl vinyl ether Monomer B3: Tetraethylene glycol methyl vinyl ether Monomer B4: Styrene

[0097] (Example A1) 0.741 g of monomer A1, 0.340 g of monomer B1, and 8.2 mg of azobisisobutyronitrile (AIBN) were dissolved in 10 mL of dehydrated acetonitrile. Tetralin was added as an internal standard substance, and the reaction was carried out at 60 °C for 24 hours under a nitrogen atmosphere while confirming the monomer consumption rate. The polymerization solution was dialyzed in acetonitrile and dried under vacuum at 120 °C to obtain 0.34 g (yield 82%) of copolymer 1. The monomer introduction ratio was A1:B1 = 62:38. The monomer introduction ratio was calculated from the 1 1H-NMR of the copolymer. Copolymer 1 had a number-average molecular weight Mn = 1.7×10 4 and a weight-average molecular weight Mw = 2.9×10 4 with a molecular weight distribution Mw / Mn = 1.70.

[0098] (Example A2) 0.936 g of monomer A1, 1.53 g of monomer B2, and 16.4 mg of AIBN were dissolved in 20 mL of dehydrated acetonitrile. Tetralin was added as an internal standard substance, and the reaction was carried out at 60 °C for 24 hours under a nitrogen atmosphere while confirming the monomer consumption rate. The polymerization solution was dialyzed in acetonitrile and dried under vacuum at 120 °C to obtain 0.637 g (yield 44%) of copolymer 2. The monomer introduction ratio was A1:B2 = 55:45. The monomer introduction ratio was calculated from the 1 1H-NMR of the copolymer. Copolymer 2 had a number-average molecular weight Mn = 4.9×10 4 and a weight-average molecular weight Mw = 7.9×10 4 with a molecular weight distribution Mw / Mn = 1.63.

[0099] (Example A3) Monomer A1: 1.17 g, Monomer B3: 2.25 g, AIBN: 24.6 mg were dissolved in 30 mL of dehydrated acetonitrile. Tetralin was added as an internal standard substance, and the reaction was carried out at 60 °C for 24 hours under a nitrogen atmosphere while confirming the monomer consumption rate. The polymerization solution was dialyzed in acetonitrile and vacuum-dried at 120 °C to obtain 1.49 g (yield 79%) of copolymer 3. The monomer introduction ratio was A1:B3 = 41:59. The monomer introduction ratio was calculated from the 1 1H-NMR of the copolymer. Copolymer 3 had a number average molecular weight Mn = 1.4×10 4 , a weight average molecular weight Mw = 2.7×10 4 , and a molecular weight distribution Mw / Mn = 1.85.

[0100] (Example A4) Monomer A1: 0.558 g, Monomer B4: 0.149 g, AIBN: 11.7 mg were dissolved in 13.4 mL of dehydrated acetonitrile. Tetralin was added as an internal standard substance, and the reaction was carried out at 60 °C for 24 hours under a nitrogen atmosphere while confirming the monomer consumption rate. The polymerization solution was dialyzed in acetonitrile and vacuum-dried at 120 °C to obtain 0.640 g (yield 87%) of copolymer 4. The monomer introduction ratio was A1:B4 = 52:48. The monomer introduction ratio was calculated from the 1 1H-NMR of the copolymer. Copolymer 4 had a number average molecular weight Mn = 8.7×10 4 , a weight average molecular weight Mw = 2.2×10 5 , and a molecular weight distribution Mw / Mn = 2.55.

[0101] (Comparative Example A1) Poly(ethylene-alt-maleic anhydride) (weight average molecular weight = 100,000 - 500,000, product number: 188050) manufactured by Aldrich was used as copolymer 5.

[0102] (Measurement of the oxidation potential of the copolymer) The oxidation potential of each copolymer of Examples A1 to A4 and Comparative Example A1 was measured as follows. In a nitrogen-substituted glove box, the copolymer was dissolved in a 1 M propylene carbonate solution of LiClO4 to prepare a polymer solution. The concentration of the copolymer in the polymer solution was 10 mM in terms of lithium ions. At room temperature (25 °C), in the above glove box, the polymer solution was injected into a three-electrode cell (manufactured by EC Frontier), and linear sweep voltammetry (sweeping rate: 5 mV / s, sweeping range: from the open circuit potential to Li / Li + reference, working electrode: platinum wire, counter electrode: lithium, reference electrode: lithium) was performed under an argon atmosphere using a measuring device (HZ7000 electrochemical measurement system, manufactured by Hokuto Denko Corporation), and the potential at which a current density of 20 μA / cm 2 was observed was taken as the oxidation potential. The results are shown in Table 1.

[0103]

Table 1

[0104] (Example B1) To 100 parts by mass of copolymer 1, 200 parts by mass of a plasticizer were added to obtain an electrolyte composition. As the plasticizer, a mixed solvent of ethylene carbonate and propylene carbonate (volume ratio 1:1) was used. Various measurements were performed on the obtained electrolyte composition. The results are shown in Table 2.

[0105] Ionic conductivity: In the glove box, under a dry argon atmosphere, an evaluation cell of a coin-type battery CR2032 was assembled. Specifically, each layer was laminated in the following order in the evaluation cell to prepare a test laminate. (Stainless steel plate / electrolyte composition / stainless steel plate) Using an impedance measuring device, measurements were performed at 25 °C, in the frequency range of 0.1 Hz to 1 MHz, and with an applied voltage of 10 mV (vs. open circuit voltage). The ionic conductivity σ can be calculated by the following formula. σ (S·cm -1 ) = t (cm) / (R (Ω) × A (cm 2 )) In the formula, R represents the value of impedance. A represents the area of the sample. t represents the thickness of the sample.

[0106] Activation energy: Ionic conductivity measurements using the above evaluation cell were also carried out under conditions of 30, 40, 50, 60, and 70 °C, and the change in ionic conductivity with respect to temperature was measured. The activation energy was calculated from the slope of the graph of the common logarithm value of ionic conductivity and the reciprocal of temperature according to the Arrhenius equation (logk = logA - Ea / RT, where k is the reaction rate constant, A is the frequency factor, Ea is the activation energy, R is the gas constant, and T is the absolute temperature).

[0107] Lithium ion transference number: In a glove box under a dry argon atmosphere, an evaluation cell of a coin-type lithium battery CR2032 was assembled. Specifically, each layer was laminated in the following order in the evaluation cell to prepare a test laminate. (Lithium / electrolyte composition / lithium) The lithium ion transference number measurement method is the one introduced in Polymer, 28, 2324 (1987). That is, at room temperature (25 °C), 10 mV was applied to the test laminate, and the initial current value (I0) and the steady-state current value (I ss ) were measured. Furthermore, the interface resistance measurement value R0 before voltage application and the interface resistance measurement value R SS after voltage application were determined by the complex impedance method. Then, the obtained values were introduced into the following formula to determine the lithium ion transference number (t Li+ ). V in the formula is the applied voltage. t Li+ = I ss (V - I0R0) / I0(V - I SS R SS )

[0108] (Example B2) An electrolyte composition was obtained in the same manner as in Example B1, except that copolymer 2 was used instead of copolymer 1. Various measurements were carried out on the obtained electrolyte composition in the same manner as in Example B1. The results are shown in Table 2.

[0109] (Example B3) An electrolyte composition was obtained in the same manner as in Example B1 except that copolymer 3 was used instead of copolymer 1. Various measurements were carried out on the obtained electrolyte composition in the same manner as in Example B1. The results are shown in Table 2.

[0110] (Example B4) An electrolyte composition was obtained in the same manner as in Example B1 except that copolymer 4 was used instead of copolymer 1. Various measurements were carried out on the obtained electrolyte composition in the same manner as in Example B1. The results are shown in Table 2.

[0111] (Example B5) 100 parts by mass of copolymer 1 and 100 parts by mass of poly(vinylidene fluoride - co - hexafluoropropylene) were mixed to produce a composite resin. The same plasticizer as in Example B1 was added to the composite resin at a ratio of 200 parts by mass per 100 parts by mass of the polymer 1 to obtain an electrolyte composition. Various measurements were carried out on the obtained electrolyte composition in the same manner as in Example B1. The results are shown in Table 2.

[0112] [Table 2]

Claims

1. A first structural unit that is at least one of the structural units (A) represented by the following formula (A), and a second structural unit that is at least one of the structural units (B1) represented by the following formula (B1) and the structural units (B2) represented by the following formula (B2), a polymer electrolyte composition containing a polymer (excluding polymers containing a polyethylene oxide chain in the main chain) and a plasticizer, The polymer satisfies at least one of the following conditions (1) and (2) and at least one of the following conditions (3) and (4). An electrolyte composition. (1) The ratio m of the first structural unit to all the structural units contained in the polymer is 0.2 to 0.8, and the ratio n of the second structural unit to all the structural units contained in the polymer is 0.2 to 0.

8. (2) The content of the first structural unit is 25 to 95% by mass, and the content of the second structural unit is 5 to 75% by mass with respect to the total mass of the polymer. (3) The number average molecular weight (Mn) of the polymer is 5000 to 200000. (4) The weight average molecular weight (Mw) of the polymer is 5000 to 300000. 【Chemical 1】 (In formula (A), X is a divalent organic group having 1 to 20 carbon atoms, Y is a halogen atom or a monovalent organic group having 1 to 20 carbon atoms, M is an alkali metal element selected from Li, Na and K, and * represents the position where the structural unit (A) is bonded to another structural unit.) [Chemical 2] (In formula (B1), R １ ~R ４ are each independently a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms. * represents the position where the structural unit (B1) is bonded to another structural unit.) [Chemical Formula 3] (In formula (B2), R １５ is a divalent organic group having 1 to 20 carbon atoms, and R １６ and R １７ are each a hydrogen atom, a halogen atom, or a monovalent organic group having 1 to 20 carbon atoms. However, the structural unit (B2) does not include a structural unit in which R １５ is —C(═O)—O—C(═O)— and both R １６ and R １７ are hydrogen atoms, and also does not include the structural units contained in the structural unit (A). )

2. The electrolyte composition according to claim 1, wherein the molar ratio of the structural unit (C) represented by the following formula (C) to the first structural unit in the polymer is 0 or more and 5 / 95 or less. 【Chemical 4】

3. The oxidation potential of the polymer is 4.5 V or more with respect to the Li / Li ＋ electrode as a reference, and the electrolyte composition according to claim 1 or 2.

4. The electrolyte composition according to any one of claims 1 to 3, wherein the second structural unit contains the structural unit (D) represented by the following formula (D). 【Formula 5】 (Z is a covalent bond, -O-, -S-, -C(=O)-, or -C(=O)O-, and R ２２ is a hydrogen atom or a monovalent hydrocarbon group, and R ２１ is a monovalent organic group. * represents the position where the structural unit (D) binds to another structural unit.)

5. The electrolyte composition according to any one of claims 1 to 4, wherein the molar ratio of the structural unit (A) to the total number of moles of the structural unit (A) and the structural unit (B1) is greater than 0.

40.

6. An electrolyte composition containing a polymer (excluding polymers containing a polyethylene oxide chain in the main chain) containing the structural unit (A) represented by the following formula (A) and a plasticizer, wherein the molar ratio of the structural unit (C) represented by the following formula (C) to the structural unit (A) in the polymer is 0 or more and 5 / 95 or less, The polymer satisfies at least one of the following conditions (3) and (4). An electrolyte composition. (3) The number average molecular weight (Mn) of the polymer is from 5,000 to 200,000. (4) The weight average molecular weight (Mw) of the polymer is from 5,000 to 300,000. 【Chemical Formula 6】 (In formula (A), X is a divalent organic group having 1 to 20 carbon atoms, Y is a halogen atom or a monovalent organic group having 1 to 20 carbon atoms, M is an alkali metal element selected from Li, Na, and K, and * represents the position where the structural unit (A) is bonded to another structural unit.) 【Chemical Formula 7】

7. The electrolyte composition according to any one of claims 1 to 6, wherein the plasticizer is an organic solvent.

8. A battery comprising the electrolyte composition according to any one of claims 1 to 7.

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