Non-aqueous electrolyte, non-aqueous electrolyte battery, and compound

Abstract

The present invention provides: a nonaqueous electrolyte solution which is used in a nonaqueous electrolyte battery having a low initial resistance value; and a compound which is contained in this nonaqueous electrolyte solution.　A nonaqueous electrolyte solution according to the present invention contains a compound represented by formula (1), a solute and a nonaqueous organic solvent. In general formula (1), each of R1 and R2 represents PO(Rf)2 or SO2Rf, and Rf represents, for example, a fluorine atom; each of R3 and R4 represents, for example, a lithium ion, or alternatively, R3 and R4 may form a ring structure together with a nitrogen atom to which the moieties are bonded, and in this case, R3 and R4 form an alkylene group in combination with each other; an oxygen atom may be contained between carbon atom-carbon atom bonds in the alkylene group; a side chain thereof may have an alkyl group; and an arbitrary hydrogen atom in the alkyl group and the alkylene group may be substituted by a fluorine atom.

Description

[Technical field]

[0001] The present invention relates to a non-aqueous electrolyte, a non-aqueous electrolyte battery, and a compound. [Background technology]

[0002] In recent years, batteries, which are electrochemical devices, have been attracting attention as energy storage systems for small, high-energy density applications such as information-related equipment and communication equipment, i.e., personal computers, video cameras, digital cameras, mobile phones, smartphones, etc., as well as large-scale, power storage systems for power applications such as electric vehicles, hybrid vehicles, and fuel cell vehicle auxiliary power sources, power storage, etc. One candidate is non-aqueous electrolyte batteries, including lithium-ion batteries, which have high energy density and voltage and can provide high capacity, and research and development of these batteries is currently being actively conducted.

[0003] As the nonaqueous electrolyte used in nonaqueous electrolyte batteries, a nonaqueous electrolyte in which a fluorine-containing electrolyte such as lithium hexafluorophosphate (hereinafter LiPF6), lithium bis(fluorosulfonylimide) (hereinafter LFSI), lithium tetrafluoroborate (hereinafter LiBF4) or the like is dissolved as a solute in a solvent such as a cyclic carbonate, a chain carbonate, or an ester is often used because it is suitable for obtaining a high-voltage and high-capacity battery. However, nonaqueous electrolyte batteries using such a nonaqueous electrolyte are not necessarily satisfactory in terms of battery characteristics such as cycle characteristics and output characteristics.

[0004] For example, in the case of a lithium-ion secondary battery, when lithium cations are inserted into the negative electrode during the initial charge, the negative electrode and lithium cations, or the negative electrode and the electrolyte solvent, react to form a coating on the surface of the negative electrode, mainly composed of lithium oxide, lithium carbonate, or lithium alkyl carbonate. This coating on the surface of the electrode is called the Solid Electrolyte Interface (SEI), and its properties have a significant effect on battery performance, such as suppressing further reductive decomposition of the solvent and suppressing deterioration of battery performance. Similarly, a coating of decomposition products is also formed on the surface of the positive electrode, which is known to play an important role in suppressing oxidative decomposition of the solvent and suppressing gas generation inside the battery.

[0005] In order to improve battery characteristics, including durability such as cycle characteristics and high-temperature storage characteristics, and input / output characteristics, it is important to form a stable SEI with high ionic conductivity and low electronic conductivity, and there have been many attempts to actively form a good SEI by adding small amounts (usually 0.001% by mass or more and 10% by mass or less) of compounds called additives to the electrolyte.

[0006] To date, optimization of various battery components, including the active materials of the positive and negative electrodes, has been studied as a means of improving the cycle characteristics, high-temperature storage characteristics, and durability of non-aqueous electrolyte batteries. Non-aqueous electrolyte-related technologies are no exception, and it has been proposed to use various additives to suppress deterioration caused by the decomposition of non-aqueous electrolyte on the surfaces of active positive and negative electrodes.

[0007] Patent Document 1 proposes that various battery characteristics, such as high-temperature storage characteristics, can be improved by adding vinylene carbonate to a non-aqueous electrolyte. This method prevents decomposition of the non-aqueous electrolyte on the electrode surface by coating the electrode with a polymer film formed by polymerization of vinylene carbonate, but lithium ions also have difficulty passing through this film, which causes an issue of increased internal resistance.

[0008] To solve this problem, the addition of lithium difluorophosphate, as disclosed in Patent Document 2, is effective, and it is known that the combined use of vinylene carbonate and lithium difluorophosphate can provide a battery that suppresses an increase in internal resistance while maintaining excellent high-temperature storage characteristics.

[0009] Furthermore, Patent Document 3 discloses a method for improving input / output characteristics and impedance characteristics by incorporating a fluorosulfonate salt into a non-aqueous electrolyte solution as a single additive, rather than as a combination of multiple additives. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 3438636 [Patent Document 2] Patent No. 3439085 [Patent Document 3] JP 2013-152956 A Summary of the Invention [Problem to be solved by the invention]

[0011] However, the inventors of the present invention have found that even when lithium difluorophosphate is added to a non-aqueous electrolyte solution containing vinylene carbonate, the effect of suppressing an increase in internal resistance is small, and that even when a non-aqueous electrolyte solution containing lithium fluorosulfonate is used as shown in Patent Document 3, the effect of improving initial input / output characteristics is small. Thus, there is still room for further study on resistance characteristics, particularly initial resistance characteristics.

[0012] The present invention has been made in view of the above circumstances, and has an object to provide a nonaqueous electrolyte and a nonaqueous electrolyte battery having a low initial resistance value, and a compound that can be suitably used in the nonaqueous electrolyte. [Means for solving the problem]

[0013] In view of the above problems, the present inventors have conducted extensive research and have found that a nonaqueous electrolyte battery having a low initial resistance value can be obtained by using a nonaqueous electrolyte containing a compound represented by general formula (1), a solute, and a nonaqueous organic solvent, thereby completing the present invention.

[0014] That is, the present inventors have found that the above problems can be solved by the following configuration. [1] A non-aqueous electrolyte solution containing a compound represented by the following general formula (1), a solute, and a non-aqueous organic solvent: [ka] [In general formula (1), R 1 and R 2 are each independently PO(R f )2 or SO2R f represents R f each independently represents a fluorine atom, or a linear perfluoroalkyl group having 1 to 4 carbon atoms or a branched perfluoroalkyl group having 3 to 4 carbon atoms, R 3 and R 4 each independently represents a hydrogen atom, a lithium ion, a sodium ion, a potassium ion, or a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, and an oxygen atom may be contained between a carbon atom-carbon atom bond in the alkyl group, or R 3 and R 4 together with the nitrogen atom to which they are attached form a ring structure, in this case R 3 and R 4 are taken together to form an alkylene group, and the alkylene group may contain an oxygen atom between a carbon atom-carbon atom bond and may have an alkyl group on its side chain. Any hydrogen atom in the alkyl group and the alkylene group may be substituted with a fluorine atom, provided that R 3 represents a lithium ion, a sodium ion, or a potassium ion, the nitrogen atom and R 3The bond with represents an ionic bond, and R 4 When R represents a lithium ion, a sodium ion, or a potassium ion, the nitrogen atom and R 4 The bond with represents an ionic bond.

[0015] [2] R in the general formula (1) 1 and R 2 are each independently POF2 or SO2F.

[0016] [3] R in the general formula (1) 1 and R 2 In the nonaqueous electrolyte according to [1] or [2], each of the above is SO2F.

[0017] [4] R in the general formula (1) 3 and R 4 each independently represents a hydrogen atom, a lithium ion, a sodium ion, or a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms.

[0018] [5] The nonaqueous electrolyte solution according to any one of [1] to [4], wherein the compound represented by the general formula (1) is a compound represented by the following formula (1a):

[0019] [ka]

[0020] [6] The non-aqueous electrolyte solution according to any one of [1] to [5], wherein the non-aqueous organic solvent contains at least one selected from the group consisting of cyclic carbonates and chain carbonates.

[0021] [7] The nonaqueous electrolyte solution according to [6], wherein the cyclic carbonate is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, and fluoroethylene carbonate, and the chain carbonate is at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate.

[0022] [8] The non-aqueous electrolyte solution according to any one of [1] to [7], wherein the content of the compound represented by the general formula (1) is 0.01% by mass to 10.0% by mass with respect to the total amount of the compound represented by the general formula (1), the solute, and the non-aqueous organic solvent.

[0023] [9] In addition, vinylene carbonate, lithium bis(oxalato)borate, lithium difluorooxalatoborate, lithium difluorobis(oxalato)phosphate, lithium tetrafluorooxalatophosphate, lithium bis(fluorosulfonyl)imide, (difluorophosphoric acid R The non-aqueous electrolyte solution according to any one of [1] to [8], comprising at least one selected from lithium (fluorosulfonyl)imide, 1,3-propene sultone, and 1,3-propane sultone in an amount of 0.01% by mass to 5.0% by mass relative to the total amount of the non-aqueous electrolyte solution.

[0024]

[10] A non-aqueous electrolyte battery comprising a positive electrode, a negative electrode, and the non-aqueous electrolyte according to any one of [1] to [9].

[0025]

[11] A compound represented by the following formula (1a):

[0026] [ka] Effect of the Invention

[0027] According to the present invention, it is possible to provide a nonaqueous electrolyte and a nonaqueous electrolyte battery having a low initial resistance value, and also to provide a compound that can be suitably used in the nonaqueous electrolyte. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The configurations and combinations thereof in the following embodiments are merely examples, and various modifications are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments, but is limited only by the claims.

[0029] In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0030] In this specification, the initial resistance value refers to the resistance value of a nonaqueous electrolyte battery immediately after the first charge / discharge operation for battery stabilization, specifically, the resistance value measured by impedance measurement immediately after three cycles of charge / discharge operation for battery stabilization.

[0031] [1. Non-aqueous electrolyte] The nonaqueous electrolyte of the present invention contains the compound represented by the above general formula (1), a solute, and a nonaqueous organic solvent.

[0032] <(I) Regarding the compound represented by general formula (1)> The non-aqueous electrolyte of the present invention contains a compound represented by general formula (1). When a non-aqueous electrolyte containing a compound represented by general formula (1) is used in a non-aqueous electrolyte battery (e.g., a lithium ion secondary battery), the compound represented by general formula (1) decomposes on the positive and negative electrodes to form a coating with good ion conductivity on the surfaces of the positive and negative electrodes. It is believed that this coating suppresses direct contact between the non-aqueous organic solvent or the solute and the electrode active material, thereby reducing the Li-ion dissociation energy of the solute. The present inventors presume that this results in a reduction in the initial resistance of the non-aqueous electrolyte battery.

[0033] The compound represented by formula (1) will be described below. In general formula (1), R 1 and R 2 are each independently PO(R f )2 or SO2R f Represents.

[0034] R f represents a fluorine atom, or a linear perfluoroalkyl group having 1 to 4 carbon atoms or a branched perfluoroalkyl group having 3 to 4 carbon atoms. R f Specific examples of the linear or branched perfluoroalkyl group having 1 to 4 carbon atoms include a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a heptafluoroisopropyl group, a nonafluoro-n-butyl group, etc. Among these, a trifluoromethyl group is preferable. R f is preferably a fluorine atom. PO(R f )2 in two R f may be the same or different.

[0035] R 1 and R 2 are each independently preferably POF2 or SO2F, and R 1 and R 2 is preferably SO2F.

[0036] In general formula (1), R 3 and R 4 each independently represents a hydrogen atom, a lithium ion, a sodium ion, a potassium ion, or a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms.

[0037] R 3 and R 4Specific examples of when represents a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, and an n-pentyl group.

[0038] The alkyl group may contain an oxygen atom between the carbon atom-carbon atom bond. Specific examples of the alkyl group containing an oxygen atom between the carbon atom-carbon atom bond include a 2-methoxyethyl group and a 2-ethoxyethyl group.

[0039] Any hydrogen atom of the alkyl group may be substituted with a fluorine atom. Examples of the alkyl group having any hydrogen atom substituted with a fluorine atom include a trifluoromethyl group, a difluoromethyl group, a fluoromethyl group, a 2,2,2-trifluoroethyl group, a 2,2-difluoroethyl group, a 2-fluoroethyl group, a 3-fluoropropyl group, a 3,3,3-trifluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, and a hexafluoroisopropyl group.

[0040] The alkyl group is preferably an alkyl group having 6 or less carbon atoms, since this can reduce the resistance when a coating is formed on an electrode. The alkyl group is more preferably an alkyl group having 4 or less carbon atoms, and is particularly preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, or a tert-butyl group.

[0041] R 3 and R 4 are each independently preferably a hydrogen atom, a lithium ion, a sodium ion, or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a lithium ion, a sodium ion, or a methyl group; R 3 and R 4 It is more preferable that each of the above is a lithium ion. Also, R 3and R 4 may form a ring structure together with the nitrogen atom to which they are attached. In this case, R 3 and R 4 are combined to form an alkylene group having 2 to 4 carbon atoms, which may contain an oxygen atom between the carbon atom-carbon atom bond in the alkylene group and may have an alkyl group on its side chain. Any hydrogen atom in the alkyl group and alkylene group may be substituted with a fluorine atom. Examples of the alkylene group include an ethylene group and a propylene group, and the ethylene group is particularly preferred.

[0042] Specifically, the compound represented by general formula (1) is preferably at least one selected from the group consisting of compounds represented by the following formulas (1a) to (1y). More preferably, it is at least one selected from the group consisting of a compound represented by formula (1a) (also referred to as compound (1a)), a compound represented by formula (1b) (also referred to as compound (1b)), a compound represented by formula (1c) (also referred to as compound (1c)), a compound represented by formula (1e) (also referred to as compound (1e)), a compound represented by formula (1p) (also referred to as compound (1p)), and a compound represented by formula (1w) (also referred to as compound (1w)), further preferably at least one selected from the group consisting of compound (1a), compound (1e), and compound (1w), and particularly preferably compound (1a).

[0043] [ka]

[0044] [ka]

[0045] [ka]

[0046] [ka]

[0047] The present invention also relates to the above compound (1a).

[0048] In the non-aqueous electrolyte solution of the present invention, the compound represented by the above general formula (1) is preferably used as an additive.

[0049] In the non-aqueous electrolyte of the present invention, the total amount of the compound represented by the general formula (1) (hereinafter also referred to as "the concentration of the compound represented by the general formula (1)") relative to the total amount (100 mass%) of the compound represented by the general formula (1), the solute, and the non-aqueous organic solvent is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, and even more preferably 0.1 mass% or more. The upper limit of the concentration of the compound represented by the general formula (1) is preferably 10.0 mass% or less, more preferably 5.0 mass% or less, and even more preferably 2.0 mass% or less. By setting the concentration of the compound represented by general formula (1) to 0.01% by mass or more, it is easy to obtain the effect of suppressing an increase in the initial resistance of a nonaqueous electrolyte battery using the nonaqueous electrolyte. On the other hand, by setting the concentration of the compound represented by general formula (1) to 10.0% by mass or less, it is possible to suppress an increase in the viscosity of the nonaqueous electrolyte, and it is easy to obtain the effect of improving the high-temperature cycle characteristics of a nonaqueous electrolyte battery using the nonaqueous electrolyte.

[0050] In one embodiment of the nonaqueous electrolyte of the present invention, the concentration of the compound represented by general formula (1) is within a range not exceeding 10.0 mass %, and one type of compound may be used alone, or two or more types of compounds may be mixed in any combination and ratio depending on the application.

[0051] The method for synthesizing the compound represented by the above general formula (1) is not particularly limited. For example, as described in Chemische Berichte (1968), 101(1), 162-73 and Journal of Chemical Research, Synopses (1977), (10), 237, the compound can be synthesized by a reaction between fluorosulfonyl isocyanate and water, or a reaction between phosgene and methylsulfamoyl fluoride. Furthermore, by reacting with an inorganic base such as an alkali metal hydride ion, R 3 and R 4 It is possible to synthesize a compound represented by the above general formula (1) in which is a lithium ion, a sodium ion, or a potassium ion.

[0052] <(II) Solute> The nonaqueous electrolyte of the present invention contains a solute. The solute is not particularly limited, but is preferably an ionic salt, and more preferably an ionic salt containing fluorine.

[0053] Examples of the solute include at least one cation selected from the group consisting of alkali metal ions, such as lithium ions and sodium ions, alkaline earth metal ions, and quaternary ammonium ions, and a hexafluorophosphate anion, a tetrafluoroborate anion, a perchlorate anion, a hexafluoroarsenate anion, a hexafluoroantimonate anion, a trifluoromethanesulfonate anion, a bis(trifluoromethanesulfonyl)imide anion, a bis(pentafluoroethanesulfonyl)imide anion, a (trifluoromethanesulfonyl)(pentafluoroethanesulfonyl)imide anion, a bis(fluorosulfonyl)imide anion, a (trifluoromethanesulfonyl)(fluorosulfonyl)imide anion, a (pentafluoroethanesulfonyl)(fluorosulfonyl)imide anion, a tris(trifluoromethanesulfonyl)methide anion, a bis(difluorophosphoryl)imide anion, a ( ... R (trifluoromethanesulfonyl)imide anion, (difluorophosphoric acid R Preferably, the anion pair is an ionic salt formed of at least one anion pair selected from the group consisting of a (fluorosulfonyl)imide anion and a difluorophosphate anion.

[0054] These solutes may be used alone or in any combination and ratio of two or more kinds depending on the application. Among these, in consideration of the energy density, output characteristics, life, etc. of a non-aqueous electrolyte battery, the cation is at least one selected from the group consisting of lithium, sodium, magnesium, and quaternary ammonium, and the anion is at least one selected from the group consisting of hexafluorophosphate anion, tetrafluoroborate anion, bis(trifluoromethanesulfonyl)imide anion, bis(fluorosulfonyl)imide anion, bis(difluorophosphoric acid) ... R (difluorophosphoric acid)imide anion, R At least one selected from the group consisting of (fluorosulfonyl)imide anion and difluorophosphate anion is preferred.

[0055] The total amount of solutes in the nonaqueous electrolyte of the present invention (hereinafter, also referred to as "solute concentration") is not particularly limited, but the lower limit is preferably 0.5 mol / L or more, more preferably 0.7 mol / L or more, and even more preferably 0.9 mol / L or more. The upper limit of the solute concentration is preferably 5.0 mol / L or less, more preferably 4.0 mol / L or less, and even more preferably 2.0 mol / L or less. By setting the solute concentration to 0.5 mol / L or more, the decrease in ion conductivity and the decrease in output characteristics of the nonaqueous electrolyte battery due to the decrease in ion conductivity and the decrease in output characteristics of the nonaqueous electrolyte battery due to the increase in viscosity of the nonaqueous electrolyte can be suppressed by setting the solute concentration to 5.0 mol / L or less.

[0056] <(III) Nonaqueous organic solvents> The type of nonaqueous organic solvent used in the nonaqueous electrolyte of the present invention is not particularly limited, and any nonaqueous organic solvent can be used. Specifically, ethyl methyl carbonate (hereinafter also referred to as "EMC"), dimethyl carbonate (hereinafter also referred to as "DMC"), diethyl carbonate (hereinafter also referred to as "DEC"), methyl propyl carbonate, ethyl propyl carbonate, methyl butyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, 2,2,2-trifluoroethyl ethyl carbonate, 2,2,2-trifluoroethyl propyl carbonate, bis(2,2,2-trifluoroethyl)carbonate, 1,1,1,3,3,3-hexafluoro-1-propyl methyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propyl ethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propyl propyl carbonate, bis(1,1,1,3,3,3-hexafluoro-1-propyl)carbonate , ethylene carbonate (hereinafter also referred to as "EC"), propylene carbonate (hereinafter also referred to as "PC"), butylene carbonate, fluoroethylene carbonate (hereinafter also referred to as "FEC"), difluoroethylene carbonate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl 2-fluoropropionate, ethyl 2-fluoropropionate, diethyl ether, dibutyl ether, diisopropyl ether, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, furan, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, N,N-dimethylformamide, acetonitrile, propionitrile, dimethyl sulfoxide, sulfolane, γ-butyrolactone, and γ-valerolactone. In the present invention, an ionic liquid having a salt structure may be used as the nonaqueous organic solvent.

[0057] The nonaqueous organic solvent is preferably at least one selected from the group consisting of cyclic carbonates and chain carbonates, which provides excellent cycle characteristics at high temperatures, and is preferably at least one selected from the group consisting of esters, which provides excellent input / output characteristics at low temperatures.

[0058] Specific examples of the cyclic carbonate include EC, PC, butylene carbonate, FEC, and the like, and among these, at least one selected from the group consisting of EC, PC, and FEC is preferable.

[0059] Specific examples of the chain carbonate include EMC, DMC, DEC, methyl propyl carbonate, ethyl propyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, 2,2,2-trifluoroethyl ethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propyl methyl carbonate, and 1,1,1,3,3,3-hexafluoro-1-propyl ethyl carbonate, and among these, at least one selected from the group consisting of EMC, DMC, DEC, and methyl propyl carbonate is preferred.

[0060] Specific examples of the ester include methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl 2-fluoropropionate, and ethyl 2-fluoropropionate.

[0061] <Other additives> As long as the gist of the present invention is not impaired, additive components that are generally used in the nonaqueous electrolyte of the present invention may be further added in any ratio. Specific examples of other additives include cyclohexylbenzene, cyclohexylfluorobenzene, fluorobenzene, biphenyl, difluoroanisole, tert-butylbenzene, tert-amylbenzene, 2-fluorotoluene, 2-fluorobiphenyl, vinylene carbonate, dimethylvinylene carbonate, vinylethylene carbonate, fluoroethylene carbonate, trans-difluoroethylene carbonate, methyl propargyl carbonate, ethyl propargyl carbonate, dipropargyl carbonate, maleic anhydride, succinic anhydride, propane sultone, 1,3-propane sultone, 1,3-propene sultone, butane sultone, methylenemethane disulfonate, dimethylmethane disulfonate, trimethylenemethane disulfonate, methyl methanesulfonate, 1,6-diisocyanatohexane, tris(trimethylsilyl)borate, succinonitrile, (ethoxy)phenyl Examples of compounds having an overcharge prevention effect, a negative electrode film forming effect, or a positive electrode protection effect include pentfluorocyclotriphosphazene, lithium difluorobis(oxalato)phosphate, sodium difluorobis(oxalato)phosphate, potassium difluorobis(oxalato)phosphate, lithium difluorooxalatoborate, sodium difluorooxalatoborate, potassium difluorooxalatoborate, lithium bis(oxalato)borate, sodium bis(oxalato)borate, potassium bis(oxalato)borate, lithium tetrafluorooxalatophosphate, sodium tetrafluorooxalatophosphate, potassium tetrafluorooxalatophosphate, lithium tris(oxalato)phosphate, lithium ethylfluorophosphate, lithium fluorophosphate, ethenesulfonyl fluoride, lithium fluorosulfonate, trifluoromethanesulfonyl fluoride, methanesulfonyl fluoride, and phenyl difluorophosphate.

[0062] The nonaqueous electrolyte of the present invention may contain a compound represented by the following general formula (2) as another additive.

[0063] [ka] [In general formula (2), R 5 ~R 7 are each independently an organic group selected from a fluorine atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may contain a fluorine atom, an oxygen atom, or an unsaturated bond. 5 ~R 7 At least one of the is a fluorine atom. M m+ is an alkali metal cation, an alkaline earth metal cation, or an onium cation, and m is an integer equal to the valence of the corresponding cation.

[0064] When the compound represented by the general formula (2) (salt having an imide anion) has at least one PF bond or SF bond, excellent low-temperature properties can be obtained. The more the number of PF bonds or SF bonds in the salt having the imide anion, the more the low-temperature properties can be improved, which is preferable. In the salt having an imide anion represented by the general formula (2), R 5 ~R 7 It is more preferable that all of the groups are fluorine atoms.

[0065] In addition, in the salt having the imide anion represented by the above general formula (2), R 5 ~R 7 At least one of the groups is a fluorine atom, R 5 ~R 7 At least one of these is preferably a compound selected from hydrocarbon groups having 6 or less carbon atoms which may contain a fluorine atom.

[0066] In addition, in the salt having the imide anion represented by the above general formula (2), R 5 ~R 7 At least one of the groups is a fluorine atom, R 5 ~R 7 at least one of which is a compound selected from a methyl group, a methoxy group, an ethyl group, an ethoxy group, a propyl group, a propoxyl group, a vinyl group, an allyl group, an allyloxy group, an ethynyl group, a 2-propynyl group, a 2-propynyloxy group, a phenyl group, a phenyloxy group, a 2,2-difluoroethyl group, a 2,2-difluoroethyloxy group, a 2,2,2-trifluoroethyl group, a 2,2,2-trifluoroethyloxy group, a 2,2,3,3-tetrafluoropropyl group, a 2,2,3,3-tetrafluoropropyloxy group, a 1,1,1,3,3,3-hexafluoroisopropyl group, and a 1,1,1,3,3,3-hexafluoroisopropyloxy group.

[0067] The counter cation M of the salt having the imide anion represented by the above general formula (2) m+ is preferably selected from the group consisting of lithium ions, sodium ions, potassium ions, and tetraalkylammonium ions.

[0068] In addition, in the above general formula (2), R 5 ~R 7 Examples of the alkyl group and alkoxy group represented by the formula (I) include alkyl groups and fluorine-containing alkyl groups having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a secondary butyl group, a tertiary butyl group, a pentyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a 2,2,3,3-tetrafluoropropyl group, and a 1,1,1,3,3,3-hexafluoroisopropyl group, as well as alkoxy groups derived from these groups.

[0069] Examples of the alkenyl group and alkenyloxy group include alkenyl groups having 2 to 10 carbon atoms, such as a vinyl group, an allyl group, a 1-propenyl group, an isopropenyl group, a 2-butenyl group, and a 1,3-butadienyl group, as well as fluorine-containing alkenyl groups and alkenyloxy groups derived from these groups.

[0070] Examples of the alkynyl group and alkynyloxy group include alkynyl groups having 2 to 10 carbon atoms, such as ethynyl group, 2-propynyl group, and 1,1 dimethyl-2-propynyl group, fluorine-containing alkynyl groups, and alkynyloxy groups derived from these groups.

[0071] Examples of the cycloalkyl group and cycloalkoxy group include cycloalkyl groups having 3 to 10 carbon atoms, such as a cyclopentyl group and a cyclohexyl group, fluorine-containing cycloalkyl groups, and cycloalkoxy groups derived from these groups.

[0072] Examples of the cycloalkenyl group and the cycloalkenyloxy group include cycloalkenyl groups having 3 to 10 carbon atoms, such as a cyclopentenyl group and a cyclohexenyl group, fluorine-containing cycloalkenyl groups, and cycloalkenyloxy groups derived from these groups.

[0073] Examples of the aryl group and aryloxy group include aryl groups having 6 to 10 carbon atoms, such as a phenyl group, a tolyl group, and a xylyl group, fluorine-containing aryl groups, and aryloxy groups derived from these groups.

[0074] Specific examples and synthesis methods of the salt having the imide anion represented by the above general formula (2) include those described in WO 2017 / 111143.

[0075] The content of the other additives in the non-aqueous electrolyte is preferably 0.01 mass % or more and 8.0 mass % or less with respect to the total amount of the non-aqueous electrolyte.

[0076] In addition, the ionic salts listed as solutes can exert a negative electrode coating effect and a positive electrode protection effect as "other additives" when the content in the non-aqueous electrolyte is less than 0.5 mol / L, which is the lower limit of the suitable concentration of the solute. In this case, the content in the non-aqueous electrolyte is preferably 0.01% by mass to 5.0% by mass. Examples of the ionic salt in this case include lithium trifluoromethanesulfonate, sodium trifluoromethanesulfonate, potassium trifluoromethanesulfonate, magnesium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, potassium bis(trifluoromethanesulfonyl)imide, magnesium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, sodium bis(fluorosulfonyl)imide, potassium bis(fluorosulfonyl)imide, magnesium bis(fluorosulfonyl)imide, (trifluoromethanesulfonyl)(fluorosulfonyl)imide lithium, sodium (trifluoromethanesulfonyl)(fluorosulfonyl)imide, potassium (trifluoromethanesulfonyl)(fluorosulfonyl)imide, magnesium (trifluorophosphoric acid), R Lithium bis(difluorophosphoric acid)imide R Sodium bis(difluorophosphoric acid)imide R potassium bis(difluorophosphoric acid)imide R (difluorophosphoric acid)magnesium imide R Lithium (difluorophosphoryl)(fluorosulfonyl)imide R (fluorosulfonyl)imide sodium, (difluorophospho R potassium (difluorophosphoryl)sulfonylimide, R (difluorophosphoric acid)magnesium (fluorosulfonyl)imide R Lithium (trifluoromethanesulfonyl)imide, (difluorophosphoric acid R (trifluoromethanesulfonyl)imide sodium, (difluorophosphoric acid R (trifluoromethanesulfonyl)imide potassium, (difluorophosphoric acid R Examples of the alkyldifluorophosphate include magnesium (trifluoromethanesulfonyl)imide, lithium difluorophosphate, and sodium difluorophosphate.

[0077] Furthermore, alkali metal salts other than the above solutes (lithium salt, sodium salt, potassium salt, magnesium salt) may be used as additives. Specific examples include carboxylates such as lithium acrylate, sodium acrylate, lithium methacrylate, and sodium methacrylate, and sulfates such as lithium methyl sulfate, sodium methyl sulfate, lithium ethyl sulfate, and sodium methyl sulfate.

[0078] The nonaqueous electrolyte of the present invention may further contain, among other additives, vinylene carbonate, lithium bis(oxalato)borate, lithium difluorooxalatoborate, lithium difluorobis(oxalato)phosphate, lithium tetrafluorooxalatophosphate, lithium bis(fluorosulfonyl)imide, (difluorophosphoric acid) R It is preferable that the non-aqueous electrolyte solution contains at least one selected from lithium (fluorosulfonyl)imide, 1,3-propene sultone, and 1,3-propane sultone in an amount of 0.01% by mass to 5.0% by mass relative to the total amount of the non-aqueous electrolyte solution. From the viewpoint of suppressing the initial resistance increase, lithium difluorooxalatoborate, (difluorophosphoric acid R It is more preferable that the lithium fluorosulfonylimide is at least one selected from lithium difluorobis(oxalato)phosphate.

[0079] The nonaqueous electrolyte of the present invention may contain a polymer, and may be used after being quasi-solidified with a gelling agent or a crosslinked polymer, as in the case of a nonaqueous electrolyte battery called a polymer battery. Polymer solid electrolytes also include those containing a nonaqueous organic solvent as a plasticizer.

[0080] The polymer is not particularly limited as long as it is an aprotic polymer capable of dissolving the compound represented by the general formula (1), the solute, and the other additives. For example, it may be a polymer having polyethylene oxide in the main chain or side chain, a homopolymer or copolymer of polyvinylidene fluoride, a methacrylic acid ester polymer, polyacrylonitrile, etc. When a plasticizer is added to these polymers, aprotic nonaqueous organic solvents are preferred among the nonaqueous organic solvents.

[0081] [2. Nonaqueous electrolyte battery] The nonaqueous electrolyte battery of the present invention includes at least the nonaqueous electrolyte of the present invention, a negative electrode, and a positive electrode, and preferably further includes a separator, an exterior body, and the like.

[0082] The negative electrode is not particularly limited, but it is preferable to use a material into which alkali metal ions such as lithium ions or sodium ions, or alkaline earth metal ions, can be reversibly inserted and removed.

[0083] The positive electrode is not particularly limited, but it is preferable to use a material into which alkali metal ions such as lithium ions or sodium ions, or alkaline earth metal ions, can be reversibly inserted and removed.

[0084] For example, when the cation is lithium, lithium metal, alloys and intermetallic compounds of lithium and other metals, various carbon materials capable of absorbing and releasing lithium, metal oxides, metal nitrides, activated carbon, conductive polymers, etc. are used as the negative electrode material. Examples of the carbon material include graphitizable carbon, non-graphitizable carbon (also called hard carbon) with a (002) plane spacing of 0.37 nm or more, and graphite with a (002) plane spacing of 0.37 nm or less. For the latter, artificial graphite, natural graphite, etc. are used.

[0085] For example, when the cation is lithium, examples of the positive electrode material that can be used include lithium-containing transition metal composite oxides such as LiCoO2, LiNiO2, LiMnO2, and LiMn2O4; mixtures of multiple transition metals such as Co, Mn, and Ni in these lithium-containing transition metal composite oxides; lithium-containing transition metal composite oxides in which a portion of the transition metal has been replaced with a metal other than the transition metal; transition metal phosphate compounds called olivine, such as LiFePO4, LiCoPO4, and LiMnPO4; oxides such as TiO2, V2O5, and MoO3; sulfides such as TiS2 and FeS; conductive polymers such as polyacetylene, polyparaphenylene, polyaniline, and polypyrrole; activated carbon; polymers that generate radicals; and carbon materials.

[0086] The positive and negative electrode materials may contain acetylene black, ketjen black, carbon fiber, or graphite as a conductive material, and polytetrafluoroethylene, polyvinylidene fluoride, SBR resin, or the like as a binder, and may be molded into a sheet to form an electrode sheet.

[0087] As a separator for preventing contact between the positive electrode and the negative electrode, a nonwoven fabric or a porous sheet made of polypropylene, polyethylene, paper, glass fiber, or the like is used.

[0088] From the above-mentioned components, an electrochemical device having a shape such as a coin shape, a cylinder shape, a square shape, or an aluminum laminate sheet shape is assembled. EXAMPLES

[0089] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to the description of these examples in any way.

[0090] <Synthesis Example 1: Synthesis of compound (1a)> Put 7.0 g of EMC and 0.07 g of water into a 50 ml eggplant flask, then add fluorosulfonate. 1.00 g of phenyl isocyanate was slowly added. After the foaming ceased, 0.07 g of lithium hydride was added and stirred overnight. The reaction solution was filtered to obtain 7.8 g of EMC solution (0.8 g of the target product, recovery rate 86%) in which 14.7 mass % of the target product was dissolved. Compound (1a): 19 F-NMR [reference material: CFCl3, deuterated solvent: CD3CN], δppm: 50.46 (s, 2F). 13 C-NMR [reference material: CD3CN, deuterated solvent CD3CN], δppm: 166.36 (s, 1C)

[0091] [Preparation of non-aqueous electrolyte solutions in examples and comparative examples] <Comparative Example 1-1> (Preparation of LiPF6 solution) In a glove box with a dew point of -60°C or less, EC, FEC, EMC, and DMC were mixed in a volume ratio of EC:FEC:EMC:DMC=2:1:3:4. Then, while keeping the internal temperature at 40°C or less, LiPF6 was added in an amount that gave a concentration of 1.0 mol / L relative to the total amount of the non-aqueous electrolyte, and the mixture was stirred to completely dissolve, obtaining a LiPF6 solution. This was designated as comparative non-aqueous electrolyte 1-1.

[0092] <Example 1-1> (Preparation of non-aqueous electrolyte 1-1) In a glove box with a dew point of -60°C or less, EC, FEC, EMC and DMC were mixed in a volume ratio of EC:FEC:EMC:DMC=2:1:3:4. Then, while maintaining the internal temperature at 40°C or less, LiPF6 was added in an amount to give a concentration of 1.0 mol / L relative to the total amount of the nonaqueous electrolyte, and compound (1a) corresponding to the compound represented by general formula (1) was added in a concentration of 0.5 mass% relative to the total amount of the nonaqueous organic solvent, the solute and the compound (1a), and the mixture was stirred for 1 hour to dissolve, thereby preparing nonaqueous electrolyte 1-1 of Example 1-1.

[0093] <Examples 1-2 to 1-7 and Comparative Examples 1-2 to 1-5> (Preparation of non-aqueous electrolytes 1-2 to 1-7 and comparative non-aqueous electrolytes 1-2 to 1-5) Non-aqueous electrolyte solutions 1-2 to 1-7 and comparative non-aqueous electrolyte solutions 1-2 to 1-5 were obtained in the same manner as in the preparation of non-aqueous electrolyte solution 1-1, except that the type and amount of the compound represented by general formula (1) (and comparative compound) were changed as shown in Table 1.

[0094] <Examples 2-1 to 2-3 and Comparative Examples 2-1 to 2-3> (Preparation of non-aqueous electrolytes 2-1 to 2-3 and comparative non-aqueous electrolytes 2-1 to 2-3) Furthermore, as another additive, vinylene carbonate was added and dissolved in a concentration shown in Table 2 relative to the total amount of the nonaqueous electrolyte solution. Nonaqueous electrolyte solutions 2-1 to 2-3 and comparative nonaqueous electrolyte solutions 2-1 to 2-3 were obtained in the same manner as in the preparation of nonaqueous electrolyte solutions 1-2, 1-5, 1-7, and comparative nonaqueous electrolyte solutions 1-1, 1-3, and 1-5, respectively.

[0095] <Examples 3-1 to 3-3 and Comparative Examples 3-1 to 3-3> (Preparation of non-aqueous electrolytes 3-1 to 3-3 and comparative non-aqueous electrolytes 3-1 to 3-3) Non-aqueous electrolyte solutions 3-1 to 3-3 and comparative non-aqueous electrolyte solutions 3-1 to 3-3 were obtained in the same manner as in the preparation of non-aqueous electrolyte solutions 2-1 to 2-3 and comparative non-aqueous electrolyte solutions 2-1 to 2-3, respectively, except that vinylene carbonate was changed to lithium bis(oxalato)borate.

[0096] <Examples 4-1 to 4-3 and Comparative Examples 4-1 to 4-3> (Preparation of non-aqueous electrolytes 4-1 to 4-3 and comparative non-aqueous electrolytes 4-1 to 4-3) Non-aqueous electrolyte solutions 4-1 to 4-3 and comparative non-aqueous electrolyte solutions 4-1 to 4-3 were obtained in the same manner as in the preparation of non-aqueous electrolyte solutions 2-1 to 2-3 and comparative non-aqueous electrolyte solutions 2-1 to 2-3, respectively, except that vinylene carbonate was changed to lithium difluorooxalatoborate.

[0097] <Examples 5-1 to 5-3 and Comparative Examples 5-1 to 5-3> (Preparation of non-aqueous electrolytes 5-1 to 5-3 and comparative non-aqueous electrolytes 5-1 to 5-3) Non-aqueous electrolyte solutions 5-1 to 5-3 and comparative non-aqueous electrolyte solutions 5-1 to 5-3 were obtained in the same manner as in the preparation of non-aqueous electrolyte solutions 2-1 to 2-3 and comparative non-aqueous electrolyte solutions 2-1 to 2-3, respectively, except that vinylene carbonate was changed to lithium difluorobis(oxalato)phosphate.

[0098] <Examples 6-1 to 6-3 and Comparative Examples 6-1 to 6-3> (Preparation of non-aqueous electrolytes 6-1 to 6-3 and comparative non-aqueous electrolytes 6-1 to 6-3) Non-aqueous electrolyte solutions 6-1 to 6-3 and comparative non-aqueous electrolyte solutions 6-1 to 6-3 were obtained in the same manner as in the preparation of non-aqueous electrolyte solutions 2-1 to 2-3 and comparative non-aqueous electrolyte solutions 2-1 to 2-3, respectively, except that vinylene carbonate was changed to lithium tetrafluorooxalatophosphate.

[0099] <Examples 7-1 to 7-3 and Comparative Examples 7-1 to 7-3> (Preparation of non-aqueous electrolytes 7-1 to 7-3 and comparative non-aqueous electrolytes 7-1 to 7-3) Non-aqueous electrolyte solutions 7-1 to 7-3 and comparative non-aqueous electrolyte solutions 7-1 to 7-3 were obtained in the same manner as in the preparation of non-aqueous electrolyte solutions 2-1 to 2-3 and comparative non-aqueous electrolyte solutions 2-1 to 2-3, respectively, except that lithium bis(fluorosulfonyl)imide was used instead of vinylene carbonate.

[0100] <Examples 8-1 to 8-3 and Comparative Examples 8-1 to 8-3> (Preparation of non-aqueous electrolytes 8-1 to 8-3 and comparative non-aqueous electrolytes 8-1 to 8-3) Non-aqueous electrolyte solutions 8-1 to 8-3 and comparative non-aqueous electrolyte solutions 8-1 to 8-3 were obtained in the same manner as in the preparation of non-aqueous electrolyte solutions 2-1 to 2-3 and comparative non-aqueous electrolyte solutions 2-1 to 2-3, respectively, except that vinylene carbonate was changed to 1,3-propene sultone.

[0101] In Tables 1 to 8 below, DFP means lithium difluorophosphate, FS means lithium fluorosulfonate, VC means vinylene carbonate, BOB means lithium bis(oxalato)borate, DFOB means lithium difluorooxalatoborate, DFBOP means lithium difluorobis(oxalato)phosphate, TFOP means lithium tetrafluorooxalatophosphate, FSI means lithium bis(fluorosulfonyl)imide, and PRS means 1,3-propene sultone.

[0102] In the following Tables 1 to 8, the amount of the compound represented by the general formula (1) (and the comparative compounds DFP and FS) added is expressed as a concentration relative to the total amount of the non-aqueous solvent, the solute, and the compound. The amount of the other additives added is expressed as a concentration relative to the total amount of the non-aqueous solvent, the solute, the compound, and the other additives.

[0103] [Preparation of non-aqueous electrolyte battery] (Preparation of NCM622 positive electrode) LiNi 0.6 Mn 0.2 Co 0.2 A positive electrode composite paste was prepared by mixing 90% by mass of O2 powder, 5% by mass of polyvinylidene fluoride (hereinafter also referred to as PVDF) as a binder, and 5% by mass of acetylene black as a conductive material, and then adding N-methyl-2-pyrrolidone. This paste was applied to both sides of aluminum foil (A1085), dried, pressed, and then punched out to 4 x 5 cm to obtain a test NCM622 positive electrode.

[0104] (Preparation of artificial graphite negative electrode) A negative electrode composite paste was prepared by mixing 90% by mass of artificial graphite powder, 5% by mass of PVDF as a binder, and 5% by mass of acetylene black as a conductive material. This paste was applied to one side of a copper foil, dried, pressed, and then punched out to a size of 4 x 5 cm to obtain a test artificial graphite negative electrode.

[0105] (Preparation of non-aqueous electrolyte battery) In an argon atmosphere with a dew point of -50°C or less, a terminal was welded to the above-mentioned NCM622 positive electrode, and then both sides were sandwiched between two polyethylene separators (5 x 6 cm), and the outside was sandwiched between two artificial graphite negative electrodes with terminals welded in advance, so that the negative electrode active material surface faced the positive electrode active material surface. Then, they were placed in an aluminum laminate bag with an opening left on one side, and after vacuum injection of nonaqueous electrolyte, the opening was sealed by heat to prepare aluminum laminate type nonaqueous electrolyte batteries of the examples and comparative examples. The nonaqueous electrolytes used were those listed in Tables 1 to 8.

[0106] 〔evaluation〕 -Initial charge / discharge- The non-aqueous electrolyte battery was placed in a thermostatic chamber at 25°C and connected to a charge / discharge device in that state. It was charged at 3 mA to 4.3 V. After maintaining 4.3 V for 1 hour, it was discharged at 6 mA to 3.0 V. This constitutes one charge / discharge cycle, and a total of three charge / discharge cycles were performed to stabilize the battery. <Initial resistance measurement> After the initial charge and discharge, the battery was charged at 25° C. and 6 mA up to 4.3 V, and the resistance value was measured by impedance measurement.

[0107] In each of Tables 1 to 8, the initial resistance value of the comparative examples (Comparative Example 1-1 in Table 1, Comparative Example 2-1 in Table 2, Comparative Example 3-1 in Table 3, Comparative Example 4-1 in Table 4, Comparative Example 5-1 in Table 5, Comparative Example 6-1 in Table 6, Comparative Example 7-1 in Table 7, and Comparative Example 8-1 in Table 8) which used a comparative nonaqueous electrolyte containing neither the compound represented by general formula (1) nor the comparative compound was set to 100, and the evaluation results of the initial resistance of each of the examples and comparative examples are shown as relative values.

[0108] [Table 1]

[0109] [Table 2]

[0110] [Table 3]

[0111] [Table 4]

[0112] [Table 5]

[0113] [Table 6]

[0114] [Table 7]

[0115] [Table 8]

[0116] As is clear from Tables 1 to 8, the nonaqueous electrolyte batteries using the nonaqueous electrolyte containing the compound represented by general formula (1) of the present invention have low initial resistance and are excellent.

Claims

1. A non-aqueous electrolyte solution containing a compound represented by the following general formula (1), a solute, and a non-aqueous organic solvent: 【Chemistry 1】 [In general formula (1), R 1 and R 2 Each independently represents PO(R f ) 2 Or SO 2 R f represents R f each independently represents a fluorine atom, or a linear perfluoroalkyl group having 1 to 4 carbon atoms or a branched perfluoroalkyl group having 3 to 4 carbon atoms, R 3 and R 4 each independently represents a hydrogen atom, a lithium ion, a sodium ion, a potassium ion, or a linear alkyl group having 1 to 12 carbon atoms or a branched alkyl group having 3 to 12 carbon atoms, and an oxygen atom may be contained between a carbon atom-carbon atom bond in the alkyl group, or R 3 and R 4 may be taken together with the nitrogen atom to which they are attached to form a cyclic structure, in which case R 3 and R 4 together form an alkylene group, in which the alkylene group may contain an oxygen atom between a carbon-carbon bond or may have an alkyl group in a side chain, and any hydrogen atom in the alkyl group and alkylene group may be substituted with a fluorine atom, However, R 3 When R represents a lithium ion, a sodium ion, or a potassium ion, the nitrogen atom and R 3 The bond with represents an ionic bond, and R 4 When R represents a lithium ion, a sodium ion, or a potassium ion, the nitrogen atom and R 4 represents an ionic bond.

2. R in the general formula (1) 1 and R 2 However, each of them is independently POF 2 Or SO 2 The nonaqueous electrolyte according to claim 1, wherein

3. R in the general formula (1) 1 and R 2 However, both are SO 2 3. The nonaqueous electrolyte according to claim 1, wherein F is a fluorine-containing compound.

4. R in the general formula (1) 3 and R 4 each independently represents a hydrogen atom, a lithium ion, a sodium ion, or a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 4 carbon atoms.

5. The nonaqueous electrolyte solution according to any one of claims 1 to 4, wherein the compound represented by the general formula (1) is a compound represented by the following formula (1a): 【Chemistry 2】

6. The nonaqueous electrolyte according to any one of claims 1 to 5, wherein the nonaqueous organic solvent contains at least one selected from the group consisting of cyclic carbonates and chain carbonates.

7. 7. The nonaqueous electrolyte according to claim 6, wherein the cyclic carbonate is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, and fluoroethylene carbonate, and the chain carbonate is at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate.

8. The content of the compound represented by the general formula (1) relative to the total amount of the compound represented by the general formula (1), the solute, and the nonaqueous organic solvent is 0.01% by mass to 10.0% by mass. The nonaqueous electrolyte solution according to any one of claims 1 to 7.

9. The non-aqueous electrolyte solution according to any one of claims 1 to 8, further comprising at least one selected from the group consisting of vinylene carbonate, lithium bis(oxalato)borate, lithium difluorooxalatoborate, lithium difluorobis(oxalato)phosphate, lithium tetrafluorooxalatophosphate, lithium bis(fluorosulfonyl)imide, lithium (difluorophosphoryl)(fluorosulfonyl)imide, 1,3-propene sultone, and 1,3-propane sultone, in an amount of 0.01% by mass to 5.0% by mass relative to the total amount of the non-aqueous electrolyte solution.

10. A non-aqueous electrolyte battery comprising a positive electrode, a negative electrode, and the non-aqueous electrolyte according to any one of claims 1 to 9.

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