JP2017208322A - Nonaqueous electrolyte solution and power storage device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte solution which can enhance high-temperature preservation characteristics and particularly suppress gas generation when a power storage device is used with a high voltage.SOLUTION: A nonaqueous electrolyte solution comprises a compound represented by the formula (I) below. (In the formula, Rto Rindependently represent H, F, an alkyl group with C1-4, a fluorinated alkyl group with C1-4, a P(=O)(OR)group or the like; Rrepresents an alkyl group with C1-4 or the like; and L represents a F-substituted/unsubstituted aliphatic divalent coupling group with C1-8 or O, provided that any one of Rto Ris a P(=O)(OR)group or the like.)SELECTED DRAWING: None

Description

  The present invention relates to a nonaqueous electrolytic solution capable of improving electrochemical characteristics when an electricity storage device is used at a high voltage, and an electricity storage device using the same.

  In recent years, power storage devices, particularly lithium secondary batteries, have been widely used as power sources for electronic devices such as mobile phones and laptop computers, or for electric vehicles and power storage. Batteries mounted on these electronic devices and automobiles are likely to be used under the high temperature of midsummer or in an environment warmed by heat generated by the electronic devices. In thin electronic devices such as tablet terminals and ultrabooks, laminated batteries and square batteries that use a laminated film such as an aluminum laminated film are often used as exterior members. However, these batteries are thin. There is a problem that it is likely to be deformed easily due to a slight expansion of the exterior member, and the influence of the deformation on the electronic device is very large.

A lithium secondary battery is mainly composed of a positive electrode and a negative electrode containing a material capable of occluding and releasing lithium, and a non-aqueous electrolyte composed of a lithium salt and a non-aqueous solvent. Examples of the non-aqueous solvent include ethylene carbonate (EC) and propylene. Carbonates such as carbonate (PC) are used.
As negative electrodes of lithium secondary batteries, lithium metal, metal compounds capable of inserting and extracting lithium (metal simple substance, oxide, alloy with lithium, etc.) and carbon materials are known. In particular, non-aqueous electrolyte secondary batteries using carbon materials that can occlude and release lithium, such as coke and graphite (artificial graphite, natural graphite), are widely used. Since the above negative electrode material stores and releases lithium and electrons at a very low potential equivalent to that of lithium metal, many solvents may undergo reductive decomposition, particularly at high temperatures. Regardless of the type, some of the solvent in the electrolyte solution undergoes reductive decomposition on the negative electrode, and the migration of lithium ions is hindered by the deposition of decomposition products, gas generation, and electrode swelling, especially at high temperatures under high temperatures. There have been problems such as deterioration of battery characteristics such as characteristics and deformation of the battery due to swelling of the electrodes. Furthermore, lithium secondary batteries using lithium metal, alloys thereof, simple metals such as tin or silicon, and oxides as negative electrode materials have high initial capacities, but fine powders progress during the cycle. In comparison, reductive decomposition of non-aqueous solvents occurs at an accelerated rate, and problems such as battery performance such as battery capacity and high-temperature storage characteristics are greatly reduced at high temperatures, and batteries are deformed due to electrode swelling. Yes.

On the other hand, a lithium secondary battery using, for example, LiCoO ₂ , LiMn ₂ O ₄ , LiNiO ₂ , LiFePO _4, or the like as the positive electrode includes a positive electrode material, a non-aqueous electrolyte, and a non-aqueous solvent in a non-aqueous electrolyte in a charged state. It has been found that degradation products and gases generated by partial oxidative decomposition at the interface of the battery interfere with the desired electrochemical reaction of the battery, resulting in degradation of electrochemical characteristics when used at high temperatures. Yes. Also, LiNi _0.5 Mn _1.5 O ₄ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , Li ₂ MnO ₃ and LiMO ₂ (M is a transition metal such as Co, Ni, Mn, Fe, etc. In order to store and release lithium and electrons at a more noble voltage, materials that can absorb and release lithium, such as solid solutions, have the potential to undergo oxidative degradation of many solvents, especially at high temperatures. Regardless of the type of positive electrode material, some of the solvent in the electrolyte solution is oxidatively decomposed on the positive electrode, and the migration of lithium ions is hindered by the deposition of decomposition products and gas generation. There was a problem of deteriorating battery characteristics.

  Patent Document 1 discloses 2-fluorosulfolane and 3-fluorosulfolane, and describes that they can be used in various fields. One of them is not described as an example of what is said to be useful as a solvent or additive for an electrolyte solution for an energy storage device. Patent Document 2 discloses a compound in which sulfolane or a hydrogen atom of sulfolane is substituted with a halogen, a vinyl group, an allyl group, a phenyl group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group. It is disclosed that a non-aqueous electrolyte containing a small amount of 3-methylsulfolane is effective in improving low-temperature output characteristics, high-temperature cycle characteristics, and storage characteristics. Patent Document 3 discloses that a chain phosphonosulfonic acid compound is effective in storage characteristics.

JP 2002-155074 A Special table 2014-528639 International Publication No. 2013/058387

  As a result of detailed studies on the performance of the above-described conventional non-aqueous electrolyte, the present inventors have evaluated the compound described in Patent Document 1 by actually adding it to the non-aqueous electrolyte and the storage characteristics are insufficient. I found out that Moreover, in the nonaqueous electrolyte secondary battery of Patent Document 2, although certain effects are recognized for the problems of low temperature output characteristics, high temperature cycle characteristics, and storage characteristics, it is sufficient when used at a high voltage. It turned out that an effect was not acquired. In addition, it was found that the non-aqueous electrolyte solution to which the chain phosphonosulfonic acid compound described in Patent Document 3 was added could not provide satisfactory results at high voltage storage characteristics. Therefore, the present inventors have conducted intensive research to solve the above problems, and improve the storage characteristics at high temperature and high voltage, particularly the effect of suppressing gas generation, by containing one or more specific compounds. The present invention has been completed.

  An object of the present invention is to provide a nonaqueous electrolytic solution capable of improving high-temperature storage characteristics when an electricity storage device is used at a high voltage and suppressing gas generation, and an electricity storage device using the same.

  That is, the present invention provides the following (1) to (3).

(1) A nonaqueous electrolytic solution for an electricity storage device, which contains at least one compound represented by the following general formula (I) in a nonaqueous electrolytic solution in which an electrolyte salt is dissolved in a nonaqueous solvent.

(Wherein R ^{1 to} R ⁶ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, or P (═O) (OR ⁷ ) _2. Group, OP (═O) (OR ⁸ ) ₂ group, OC (═O) R ⁹ group, or OS (═O) ₂ R ¹⁰ group, R ^{7 to} R ¹⁰ are alkyl groups having 1 to 4 carbon atoms. , A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms, L is a fluorine atom in which at least one hydrogen atom having 1 to 8 carbon atoms is fluorine An aliphatic divalent linking group optionally substituted with an atom or an oxygen atom, provided that at least one of R ^{1 to} R ⁶ is a P (═O) (OR ⁷ ) ₂ group or an OP (═O ) (OR ⁸ ) ₂ groups.)

(2) An electricity storage device comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte in which an electrolyte salt is dissolved in a non-aqueous solvent, wherein the non-aqueous electrolyte is at least a compound represented by the following general formula (I) A power storage device characterized by being a non-aqueous electrolyte containing one kind.

(Wherein R ^{1 to} R ⁶ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, or P (═O) (OR ⁷ ) _2. Group, OP (═O) (OR ⁸ ) ₂ group, OC (═O) R ⁹ group, or OS (═O) ₂ R ¹⁰ group, R ^{7 to} R ¹⁰ are alkyl groups having 1 to 4 carbon atoms. , A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms, L is a fluorine atom in which at least one hydrogen atom having 1 to 8 carbon atoms is fluorine An aliphatic divalent linking group optionally substituted with an atom or an oxygen atom, provided that at least one of R ^{1 to} R ⁶ is a P (═O) (OR ⁷ ) ₂ group or an OP (═O ) (OR ⁸ ) ₂ groups.)

  (3) Compounds represented by the following general formulas (VII) to (IX).

(In the formula, R ^{61 to} R ⁶⁷ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an OC (═O) R ¹⁹ group, OP ( ═O) (OEt) ₂ group, P (═O) (OEt) ₂ group, or OS (═O) ₂ R ²⁰ group, R ^{19 to} R ²⁰ are alkyl groups having 1 to 4 carbon atoms, carbon number A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms.)

(In the formula, R ^{71 to} R ⁷⁷ each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an OC (═O) R ²⁹ group, OP ( ═O) (OEt) ₂ group, P (═O) (OEt) ₂ group, or OS (═O) ₂ R ³⁰ group, R ^{29 to} R ³⁰ are alkyl groups having 1 to 4 carbon atoms, carbon number A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms, except that all of R ^{71 to} R ⁷⁷ are hydrogen atoms.

(In the formula, R ^{81 to} R ⁸⁷ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, or an OC (═O) R ⁵⁹ group. , OP (═O) (OEt) ₂ group, or OS (═O) ₂ R ⁶⁰ group, wherein R ^{59 to} R ⁶⁰ are alkyl groups having 1 to 4 carbon atoms and fluorinated alkyl groups having 1 to 4 carbon atoms. Represents an aryl group having 6 to 12 carbon atoms or a halogenated aryl group having 6 to 12 carbon atoms.)

  According to the present invention, there are provided a nonaqueous electrolytic solution capable of improving high-temperature storage characteristics when an electricity storage device is used at a high voltage, particularly suppressing gas generation, and an electricity storage device such as a lithium battery using the nonaqueous electrolyte. be able to.

  The present invention relates to a non-aqueous electrolyte and an electricity storage device using the same.

[Non-aqueous electrolyte]
The nonaqueous electrolytic solution of the present invention is a nonaqueous electrolytic solution in which an electrolyte salt is dissolved in a nonaqueous solvent, wherein the nonaqueous electrolytic solution contains the compound represented by the general formula (I) in the nonaqueous electrolytic solution. To do.

  The reason why the nonaqueous electrolytic solution according to the present invention improves the high-temperature storage characteristics under a high voltage is not clear, but is considered as follows. The compound represented by the general formula (I) has a phosphonate skeleton or a phosphate skeleton, and a sulfur-containing heterocyclic skeleton is bonded to a phosphorus atom directly or via oxygen, and the sulfur atom is hexavalent. It is an oxidized special compound. It is considered that the sulfur-containing heterocyclic skeleton has strong oxidation resistance and serves as an electron-withdrawing group to promote reductive decomposition of the phosphonate skeleton or phosphate skeleton. This phosphonate decomposition product containing a sulfur-containing heterocyclic skeleton forms a film on the negative electrode, and part of the film also forms a film on the positive electrode surface, preventing the decomposition of the solvent even when using electricity storage devices at high voltages. It is assumed that gas generation is suppressed. Such an effect was found to be an effect unique to the present invention that cannot be obtained with 2-fluorosulfolane described in Patent Document 1 or a phosphonate bonded with a chain sulfonic acid compound described in Patent Document 3.

  The compound contained in the nonaqueous electrolytic solution of the present invention is represented by the following general formula (I).

(Wherein R ^{1 to} R ⁶ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, or P (═O) (OR ⁷ ) _2. Group, OP (═O) (OR ⁸ ) ₂ group, OC (═O) R ⁹ group, or OS (═O) ₂ R ¹⁰ group, R ^{7 to} R ¹⁰ are alkyl groups having 1 to 4 carbon atoms. , A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms, L is a fluorine atom in which at least one hydrogen atom having 1 to 8 carbon atoms is fluorine An aliphatic divalent linking group optionally substituted with an atom or an oxygen atom, provided that at least one of R ^{1 to} R ⁶ is a P (═O) (OR ⁷ ) ₂ group or an OP (═O ) (OR ⁸ ) ₂ groups.)

  The compound represented by the general formula (I) is preferably represented by the following general formulas (II) to (VI).

(Wherein R ^{11 to} R ¹⁷ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an OC (═O) R ¹⁹ group, OP ( ═O) (OEt) ₂ group, P (═O) (OEt) ₂ group, or OS (═O) ₂ R ²⁰ group, R ^{18 to} R ²⁰ are alkyl groups having 1 to 4 carbon atoms, carbon number A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms.)

(Wherein R ^{21 to} R ²⁷ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an OC (═O) R ²⁹ group, OP ( ═O) (OEt) ₂ group, P (═O) (OEt) ₂ group, or OS (═O) ₂ R ³⁰ group, R ^{28 to} R ³⁰ are alkyl groups having 1 to 4 carbon atoms, carbon number A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms.)

(In the formula, R ^{31 to} R ³⁵ each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, or a fluorinated alkyl group having 1 to 4 carbon atoms, and R ³⁶ represents 1 to 4 carbon atoms. Or an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms.)

(In the formula, R ^{41 to} R ⁴⁵ are each independently synonymous with R ^{31 to} R ³⁵ defined in general formula (IV), and R ⁴⁶ is synonymous with R ³⁶ defined in general formula (IV).)

Wherein R ^{51 to} R ⁵⁷ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, or an OC (═O) R ⁵⁹ group. , OP (= O) (OEt) ₂ group, or OS (= O) ₂ R ⁶⁰ group, wherein R ^{58 to} R ⁶⁰ are alkyl groups having 1 to 4 carbon atoms and fluorinated alkyl groups having 1 to 4 carbon atoms. Represents an aryl group having 6 to 12 carbon atoms or a halogenated aryl group having 6 to 12 carbon atoms.)

  Among the compounds of the general formulas (II) to (VI), they are represented by the general formulas (II) to (IV) or (VI) from the viewpoint of suppressing high temperature storage characteristics at a higher voltage, particularly gas. Compounds are more preferred, compounds represented by general formula (II), (III) or (VI) are more preferred, and compounds represented by general formula (II) are particularly preferred.

In the compound represented by the general formula (II) of the present invention, R ^{11 to} R ¹⁷ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, OC (= O) R ¹⁹ group, OP (= O) (OEt) ₂ group, P (= O) (OEt) ₂ group, or OS (= O) ₂ R ²⁰ group is shown, hydrogen atom, carbon number 1 To 4 alkyl groups or OC (═O) R ¹⁹ groups are preferred, hydrogen atoms or alkyl groups having 1 to 2 carbon atoms are more preferred, and hydrogen atoms are particularly preferred.

Specific examples when R ^{11 to} R ¹⁷ are an alkyl group having 1 to 4 carbon atoms or a fluorinated alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, and an n-butyl group. Alkyl group such as iso-propyl group, tert-butyl group or sec-butyl group, or trifluoromethyl group, 2-fluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl Group, 3-fluoropropyl group, 3,3-difluoropropyl group, 3,3,3-trifluoropropyl group, 2,2,3,3-tetrafluoropropyl group, or 2,2,3,3,3 Preferred examples include fluorinated alkyl groups such as a pentafluoropropyl group. Of these, a methyl group, an ethyl group, an n-propyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

^Further, R 11 ^{to R 17} are, OC (= ^{O) R 19} group, or an OS ₍₌ O) ^{2 R 20 group,} R 19 ^{to R 20} is an alkyl group having 1 to 4 carbon atoms, atoms 1 Represents a fluorinated alkyl group having 4 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 10 carbon atoms. And an alkyl group having 1 to 2 carbon atoms is more preferred.

Specific examples of R ^{19 to} R ²⁰ include methyl groups, ethyl groups, n-propyl groups, n-butyl groups, iso-propyl groups, tert-butyl groups, sec-butyl groups and other alkyl groups, trifluoro Methyl group, 2-fluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, 3-fluoropropyl group, 3,3-difluoropropyl group, 3,3,3-trifluoro Fluorinated alkyl groups such as propyl group, 2,2,3,3-tetrafluoropropyl group, or 2,2,3,3,3-pentafluoropropyl group, phenyl group, 2-methylphenyl group, 3-methyl An aryl group such as a phenyl group, a 4-methylphenyl group, a 2,4-di-tert-butylphenyl group, or a 4-tert-butylphenyl group; Fluorophenyl group, 3-fluorophenyl group, 4-fluorophenyl group, 2-chlorophenyl group, 3-chlorophenyl group, 4-chlorophenyl group, 2-trifluoromethylphenyl group, 3-trifluoromethylphenyl group, 4-trifluoro Methylphenyl group, 4-fluoro-2-trifluoromethylphenyl group, 4-fluoro-3-trifluoromethylphenyl group, 2,4-difluorophenyl group, 2,6-difluorophenyl group, 3,5-difluorophenyl Preferred examples include halogenated aryl groups such as a group, 2,4,6-trifluorophenyl group, 2,3,5,6-tetrafluorophenyl group and perfluorophenyl group. Of these, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or a phenyl group is preferable, and a methyl group or an ethyl group is more preferable.

In the general formula (II), R ¹⁸ represents an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aryl halide having 6 to 12 carbon atoms. Represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 10 carbon atoms, and more preferably an alkyl group having 1 to 2 carbon atoms.

Specific examples of R ¹⁸ include methyl groups, ethyl groups, n-propyl groups, n-butyl groups, iso-propyl groups, tert-butyl groups, sec-butyl groups and other alkyl groups, trifluoromethyl groups, 2-fluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, 3-fluoropropyl group, 3,3-difluoropropyl group, 3,3,3-trifluoropropyl group, Fluorinated alkyl groups such as 2,2,3,3-tetrafluoropropyl group or 2,2,3,3,3-pentafluoropropyl group, phenyl group, 2-methylphenyl group, 3-methylphenyl group, Aryl groups such as 4-methylphenyl group, 2,4-di-tert-butylphenyl group, or 4-tert-butylphenyl group, or 2-fluorophenyl Nyl group, 3-fluorophenyl group, 4-fluorophenyl group, 2-chlorophenyl group, 3-chlorophenyl group, 4-chlorophenyl group, 2-trifluoromethylphenyl group, 3-trifluoromethylphenyl group, 4-trifluoro Methylphenyl group, 4-fluoro-2-trifluoromethylphenyl group, 4-fluoro-3-trifluoromethylphenyl group, 2,4-difluorophenyl group, 2,6-difluorophenyl group, 3,5-difluorophenyl Preferred examples include halogenated aryl groups such as a group, 2,4,6-trifluorophenyl group, 2,3,5,6-tetrafluorophenyl group and perfluorophenyl group. Of these, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or a phenyl group is preferable, and a methyl group or an ethyl group is more preferable.

  Specific examples of the compound represented by the general formula (II) of the present invention include, but are not limited to, the following compounds.

  Among these compounds, compounds A1 to A12, A15, A18, A19, A23 to A25, and A31 are preferable, and dimethyl (1,1-dioxidetetrahydrothiophen-2-yl) phosphonate (compound A1), diethyl (1, 1-dioxidetetrahydrothiophen-2-yl) phosphonate (compound A2), di-n-propyl (1,1-dioxidetetrahydrothiophen-2-yl) phosphonate (compound A3), di-n-butyl (1, 1-dioxidetetrahydrothiophen-2-yl) phosphonate (compound A4), diphenyl (1,1-dioxidetetrahydrothiophen-2-yl) phosphonate (compound A12), and bis (4-tert-butylphenyl) (1 , 1-Dioxidetetrahydrothiophen-2-yl) More preferred are sulfonate (compound A15), dimethyl (1,1-dioxidetetrahydrothiophen-2-yl) phosphonate (compound A1) and diethyl (1,1-dioxidetetrahydrothiophen-2-yl) phosphonate (compound A2). Is more preferable.

In the compound represented by the general formula (III) of the present invention, R ^{21 to} R ²⁷ are each independently synonymous with R ^{11 to} R ¹⁷ defined in the general formula (II), and include a hydrogen atom, a fluorine atom, and a carbon number. 1 to 4 alkyl groups, 1 to 4 carbon fluorinated alkyl groups, OC (= O) R ²⁹ groups, OP (= O) (OEt) ₂ groups, P (= O) (OEt) ₂ groups, or OS (═O) ₂ R ³⁰ group is shown, and among them, a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an OC (═O) R ²⁹ group is preferable, and a hydrogen atom or an alkyl group having 1 to 2 carbon atoms is more preferable. Preferably, a hydrogen atom is particularly preferable.

Specific examples of the case where R ^{21 to} R ²⁷ are an alkyl group having 1 to 4 carbon atoms or a fluorinated alkyl group having 1 to 4 carbon atoms include R ^{11 to} R ¹⁷ in the general formula (II) 4 is the same as the specific examples in the case of an alkyl group of 4 or a fluorinated alkyl group of 1 to 4 carbon atoms, and among them, a methyl group, an ethyl group, an n-propyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is preferable. Groups are more preferred.

^Further, when R 21 ^{to R 27} is OC (= ^{O) R 29} group, or OS ₍₌ O) ^{2 R 30 group, R} 19 in the general formula (II) R 29 ^{~R 30} each independently to R ²⁰ in the above formula each independently represent an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms And an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 10 carbon atoms is preferable, and an alkyl group having 1 to 2 carbon atoms is more preferable.

Specific examples of R ^{29 to} R ³⁰ are the same as the specific examples of R ^{19 to} R ²⁰ in the general formula (II), and among them, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or phenyl Group is preferable, and a methyl group or an ethyl group is more preferable.

In the general formula (III), R ²⁸ has the same meaning as R ¹⁸ defined in the general formula (II). Among them, an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 10 carbon atoms is preferable, and 1 to Two alkyl groups are more preferred.

Specific examples of R ²⁸ are the same as specific examples of R ¹⁸ in the general formula (II). Among them, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or a phenyl group is preferable, and a methyl group or More preferred is an ethyl group.

  Specific examples of the compound represented by the general formula (III) of the present invention include, but are not limited to, the following compounds.

  Among these compounds, compounds B1 to B13 and B16 to B18 are preferable, and dimethyl (1,1-dioxidetetrahydrothiophen-3-yl) phosphonate (compound B1), diethyl (1,1-dioxidetetrahydrothiophene-3) -Yl) phosphonate (compound B2), di-n-propyl (1,1-dioxidetetrahydrothiophen-3-yl) phosphonate (compound B3), di-n-butyl (1,1-dioxidetetrahydrothiophene-3) -Yl) phosphonate (compound B4), diphenyl (1,1-dioxidetetrahydrothiophen-3-yl) phosphonate (compound B12), tetraethyl (1,1-dioxidetetrahydrothiophene-3,4-diyl) bis (phosphonate) ) (Compound B17), and 4- (dieto) Ciphosphoryl) 1,1-dioxidetetrahydrothiophen-3-yl acetate (Compound B18) is more preferred, and dimethyl (1,1-dioxidetetrahydrothiophen-3-yl) phosphonate (Compound B1), diethyl (1,1- Dioxide tetrahydrothiophen-3-yl) phosphonate (compound B2) and 4- (diethoxyphosphoryl) 1,1-dioxidetetrahydrothiophen-3-yl acetate (compound B18) are more preferred.

In the compound represented by the general formula (IV) of the present invention, R ^{31 to} R ³⁵ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, or a fluorinated alkyl group having 1 to 4 carbon atoms. A hydrogen atom or an alkyl group having 1 to 4 carbon atoms is preferable, a hydrogen atom or an alkyl group having 1 to 2 carbon atoms is more preferable, and a hydrogen atom is particularly preferable.

Specific examples in the case where R ^{31 to} R ³⁵ are an alkyl group having 1 to 4 carbon atoms or a fluorinated alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, alkyl group such as iso-propyl group, tert-butyl group, or sec-butyl group, or trifluoromethyl group, 2-fluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group , 3-fluoropropyl group, 3,3-difluoropropyl group, 3,3,3-trifluoropropyl group, 2,2,3,3-tetrafluoropropyl group, or 2,2,3,3,3- Preferable examples include fluorinated alkyl groups such as a pentafluoropropyl group. Of these, a methyl group, an ethyl group, an n-propyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

In the general formula (IV), R ³⁶ represents an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms. And an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 10 carbon atoms is preferable, and an alkyl group having 1 to 2 carbon atoms is more preferable.

Specific examples of the R ³⁶ include an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an iso-propyl group, a tert-butyl group, or a sec-butyl group, a trifluoromethyl group, 2 -Fluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, 3-fluoropropyl group, 3,3-difluoropropyl group, 3,3,3-trifluoropropyl group, 2 , 2,3,3-tetrafluoropropyl group, fluorinated alkyl group such as 2,2,3,3,3-pentafluoropropyl group, phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4 -Arylphenyl group such as methylphenyl group, 2,4-di-tert-butylphenyl group, or 4-tert-butylphenyl group, or 2-fluorophenyl 3-fluorophenyl group, 4-fluorophenyl group, 2-chlorophenyl group, 3-chlorophenyl group, 4-chlorophenyl group, 2-trifluoromethylphenyl group, 3-trifluoromethylphenyl group, 4-trifluoromethylphenyl Group, 4-fluoro-2-trifluoromethylphenyl group, 4-fluoro-3-trifluoromethylphenyl group, 2,4-difluorophenyl group, 2,6-difluorophenyl group, 3,5-difluorophenyl group, Preferable examples include halogenated aryl groups such as 2,4,6-trifluorophenyl group, 2,3,5,6-tetrafluorophenyl group and perfluorophenyl group. Of these, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or a phenyl group is preferable, and a methyl group or an ethyl group is more preferable.

  Specific examples of the compound represented by the general formula (IV) of the present invention include, but are not limited to, the following compounds.

  Among these compounds, compounds C1 to C12, C15, C18 to C21, and C24 are preferable, and dimethyl (2,2-dioxide-1,2-oxathiolan-3-yl) phosphonate (compound C1), diethyl (2,2 -Dioxide-1,2-oxathiolan-3-yl) phosphonate (compound C2), di-n-propyl (2,2-dioxide-1,2-oxathiolan-3-yl) phosphonate (compound C3), di-n -Butyl (2,2-dioxide-1,2-oxathiolan-3-yl) phosphonate (compound C4), diphenyl (2,2-dioxide-1,2-oxathiolan-3-yl) phosphonate (compound C12), and Bis (4-tert-butylphenyl) (2,2-dioxide-1,2-oxathiolan-3-yl) phos (Nato) (Compound C15) is more preferred, and dimethyl (2,2-dioxide-1,2-oxathiolan-3-yl) phosphonate (Compound C1) and diethyl (2,2-dioxide-1,2-oxathiolane-3- Yl) phosphonate (compound C2) is more preferred.

In the compound represented by the general formula (V) of the present invention, R ^{41 to} R ⁴⁵ are each independently synonymous with R ^{31 to} R ³⁵ defined in the general formula (IV), and among them, a hydrogen atom or a carbon number of 1 to 4 is preferable, a hydrogen atom or an alkyl group having 1 to 2 carbon atoms is more preferable, and a hydrogen atom is particularly preferable.

Specific examples of the case where R ^{41 to} R ⁴⁵ are an alkyl group having 1 to 4 carbon atoms or a fluorinated alkyl group having 1 to 4 carbon atoms include R ^{31 to} R ³⁵ in the general formula (IV) 4 is the same as the specific examples in the case of an alkyl group of 4 or a fluorinated alkyl group of 1 to 4 carbon atoms, and among them, a methyl group, an ethyl group, an n-propyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is preferable. Groups are more preferred.

In the general formula (V), R ⁴⁶ has the same definition as R ³⁶ defined in the general formula (IV). Among them, an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 10 carbon atoms is preferable, and 1 to Two alkyl groups are more preferred.

Specific examples of the R ⁴⁶ are the same as the specific examples of R ³⁶ in the general formula (II). Among them, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or a phenyl group is preferable. More preferred is an ethyl group.

  Specific examples of the compound represented by the general formula (V) of the present invention include, but are not limited to, the following compounds.

  Among these compounds, compounds D1 to D13 and D16 are preferable, and dimethyl (2,2-dioxide-1,2-oxathiolan-4-yl) phosphonate (compound D1), diethyl (2,2-dioxide-1,2- Oxathiolan-4-yl) phosphonate (compound D2), di-n-propyl (2,2-dioxide-1,2-oxathiolan-4-yl) phosphonate (compound D3), di-n-butyl (2,2- Dioxide-1,2-oxathiolan-4-yl) phosphonate (Compound D4) and diphenyl (2,2-dioxide-1,2-oxathiolan-4-yl) phosphonate (Compound D12) are more preferred, and dimethyl (2, 2-dioxide-1,2-oxathiolan-4-yl) phosphonate (compound D1) and diethyl (2, - dioxide-1,2-oxathiolane-4-yl) phosphonate (compound D2) is more preferable.

In the compound represented by the general formula (VI) of the present invention, R ^{51 to} R ⁵⁷ are each independently synonymous with R ^{11 to} R ¹⁷ defined in the general formula (II), and each independently represents a hydrogen atom or a fluorine atom. , An alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an OC (═O) R ²⁹ group, an OP (═O) (OEt) ₂ group, or OS (═O) ₂ R ^30. Among them, a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and an OC (═O) R ²⁹ group are preferable, a hydrogen atom or an alkyl group having 1 to 2 carbon atoms is more preferable, and a hydrogen atom is particularly preferable.

Specific examples of the case where R ^{51 to} R ⁵⁷ are an alkyl group having 1 to 4 carbon atoms or a fluorinated alkyl group having 1 to 4 carbon atoms include R ^{11 to} R ¹⁷ in the general formula (II) 4 is the same as the specific examples in the case of an alkyl group of 4 or a fluorinated alkyl group of 1 to 4 carbon atoms, and among them, a methyl group, an ethyl group, an n-propyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is preferable. Groups are more preferred.

^Further, when R 51 ^{to R 57} is OC (= ^{O) R 59} group, or OS ₍₌ O) ^{2 R 60 group, R} 19 in the general formula (II) R 59 ^{~R 60} each independently to R ²⁰ in the above formula each independently represent an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms And an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 10 carbon atoms is preferable, and an alkyl group having 1 to 2 carbon atoms is more preferable.

Specific examples of R ^{59 to} R ⁶⁰ are the same as the specific examples of R ^{19 to} R ²⁰ in the general formula (II), and among them, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or phenyl Group is preferable, and a methyl group or an ethyl group is more preferable.

In General Formula (VI), R ⁵⁸ has the same meaning as R ¹⁸ defined in General Formula (II), and among them, an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 10 carbon atoms is preferable. Two alkyl groups are more preferred.

Specific examples of R ⁵⁸ are the same as specific examples of R ¹⁸ in the general formula (II), and among them, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or a phenyl group is preferable, and a methyl group or More preferred is an ethyl group.

  Specific examples of the compound represented by the general formula (VI) of the present invention include, but are not limited to, the following compounds.

  Among these compounds, compounds E1 to E13 and E16 to E18 are preferable, and 1,1-dioxidetetrahydrothiophen-3-yl dimethylphosphate (compound E1), 1,1-dioxidetetrahydrothiophen-3-yl diethylphosphate (Compound E2), 1,1-dioxidetetrahydrothiophen-3-yl di-n-propyl phosphate (Compound E3), 1,1-dioxidetetrahydrothiophen-3-yl di-n-butyl phosphate (Compound E4) 1,1-dioxidetetrahydrothiophen-3-yl diphenyl phosphate (compound E12), 1,1-dioxide tetrahydrothiophene-3,4-diyl tetraethylbisphosphate (compound E17), and 4-diethylphosphoryloxy-1 1-dioxidetetrahydrothiophen-3-yl acetate (Compound 18) is more preferred, 1,1-dioxidetetrahydrothiophen-3-yl dimethyl phosphate (Compound E1), 1,1-dioxidetetrahydrothiophen-3-yl Diethyl phosphate (compound E2), 1,1-dioxidetetrahydrothiophene-3,4-diyl tetraethylbisphosphate (compound E17), and 4-diethylphosphoryloxy-1,1-dioxidetetrahydrothiophen-3-yl acetate ( More preferred is compound 18).

  In the nonaqueous electrolytic solution of the present invention, the content of the compounds represented by the general formulas (I) to (VI) is preferably 0.01 to 10% by mass with respect to the total amount of the nonaqueous electrolytic solution. If the content is 10% by mass or less, a coating film is excessively formed on the electrode, and there is little risk of deterioration of storage characteristics when the battery is used at high temperature and high voltage. If the battery is used at a high temperature and a high voltage, the effect of improving the storage characteristics is enhanced. The content is preferably 0.1% by mass or more, and more preferably 0.3% by mass or more with respect to the total amount of the nonaqueous electrolytic solution. Moreover, the upper limit is preferably 5% by mass or less, and more preferably 3% by mass or less.

[Nonaqueous solvent]
As the nonaqueous solvent used in the nonaqueous electrolytic solution of the present invention, one or more selected from the group consisting of cyclic carbonates, chain esters, lactones, ethers, and amides are preferably mentioned, and two or more are more preferable. It is. Since electrochemical properties are synergistically improved at high temperatures, it is preferable that a chain ester is included, more preferably a chain carbonate is included, and most preferably both a cyclic carbonate and a chain carbonate are included. .

  The term “chain ester” is used as a concept including a chain carbonate and a chain carboxylic acid ester.

  Examples of the cyclic carbonate include ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 4-fluoro-1,3-dioxolan-2-one (FEC), trans or Cis-4,5-difluoro-1,3-dioxolan-2-one (hereinafter collectively referred to as “DFEC”), vinylene carbonate (VC), vinyl ethylene carbonate (VEC), and 4-ethynyl-1 , 3-Dioxolan-2-one (EEC) is preferably selected from the group consisting of ethylene carbonate, propylene carbonate, 4-fluoro-1,3-dioxolan-2-one, vinylene carbonate, and 4 -Ethynyl-1,3-dioxolan-2-one (EEC) One or more selected from the group consisting of are preferred, two or more is more preferable.

  In addition, it is preferable to use at least one of an unsaturated bond such as a carbon-carbon double bond or a carbon-carbon triple bond or a cyclic carbonate having a fluorine atom, since the electrochemical properties at a high temperature are further improved. More preferably, both a cyclic carbonate having an unsaturated bond such as a double bond or a carbon-carbon triple bond and a cyclic carbonate having a fluorine atom are included. As the cyclic carbonate having an unsaturated bond such as a carbon-carbon double bond or carbon-carbon triple bond, VC, VEC, or EEC is more preferable, and as the cyclic carbonate having a fluorine atom, FEC or DFEC is more preferable.

  The content of the cyclic carbonate having an unsaturated bond such as a carbon-carbon double bond or a carbon-carbon triple bond is preferably 0.07% by volume or more, more preferably 0.8%, based on the total volume of the nonaqueous solvent. 2 vol% or more, more preferably 0.7 vol% or more, and the upper limit thereof is preferably 7 vol% or less, more preferably 4 vol% or less, further preferably 2.5 vol% or less. And, it is preferable because the stability of the coating at a high temperature can be further increased without impairing the Li ion permeability.

The content of the cyclic carbonate having a fluorine atom is preferably 0.07% by volume or more, more preferably 4% by volume or more, further preferably 7% by volume or more, particularly preferably based on the total volume of the nonaqueous solvent. It is 10 volume% or more. Further, the upper limit is preferably 35% by volume or less, more preferably 33% by volume or less, and further 30% by volume or less, which further increases the stability of the coating film at high temperatures without impairing the Li ion permeability. Is preferable.
In particular, when the cyclic carbonate having a fluorine atom is contained in the range of 10 to 35% by volume, the tertiary carboxylic acid ester represented by the general formula (I) is contained in the range of 10 to 40% by volume. This is preferable because the high-temperature storage characteristics under voltage can be further improved.

  When the non-aqueous solvent contains both a cyclic carbonate having an unsaturated bond such as a carbon-carbon double bond or a carbon-carbon triple bond and a cyclic carbonate having a fluorine atom, the carbon to the content of the cyclic carbonate having a fluorine atom The content of the cyclic carbonate having an unsaturated bond such as a carbon double bond or a carbon-carbon triple bond is preferably 0.2% by volume or more, more preferably 3% by volume or more, and further preferably 7% by volume or more. The upper limit is preferably 40% by volume or less, more preferably 30% by volume or less, and further 15% by volume or less, which may further increase the stability of the coating at high temperatures without impairing Li ion permeability. This is particularly preferable because it can be performed.

  Further, when the non-aqueous solvent contains both ethylene carbonate and a cyclic carbonate having an unsaturated bond such as a carbon-carbon double bond or a carbon-carbon triple bond, the stability of the coating film formed on the electrode at high temperature is improved. Preferably, the content of cyclic carbonate having an unsaturated bond such as ethylene carbonate and a carbon-carbon double bond or a carbon-carbon triple bond is preferably 3% by volume or more based on the total volume of the nonaqueous solvent. Preferably it is 5 volume% or more, More preferably, it is 7 volume% or more, Moreover, as the upper limit, Preferably it is 45 volume% or less, More preferably, it is 35 volume% or less, More preferably, it is 25 volume% or less.

  These solvents may be used singly, and when used in combination of two or more, it is preferable because the electrochemical properties at high temperature are further improved, especially in combination of three or more. preferable. Preferred combinations of these cyclic carbonates include EC and PC, EC and VC, PC and VC, VC and FEC, EC and FEC, PC and FEC, FEC and DFEC, EC and DFEC, PC and DFEC, VC and DFEC , VEC and DFEC, VC and EEC, EC and EEC, EC and PC and VC, EC and PC and FEC, EC and VC and FEC, EC and VC and VEC, EC and VC and EEC, EC and EEC and FEC, PC And VC and FEC, EC and VC and DFEC, PC and VC and DFEC, EC and PC and VC and FEC, or EC and PC, VC and DFEC are preferable. Of the above combinations, EC and VC, EC and FEC, PC and FEC, EC and PC and VC, EC and PC and FEC, EC and VC and FEC, EC and VC and EEC, EC and EEC and FEC, PC and A combination of VC and FEC, or EC and PC and VC and FEC is more preferable, such as PC and FEC, EC and PC and VC, EC and PC and FEC, PC and VC and FEC, or EC and PC and VC and FEC. A combination including PC is more preferred because it improves battery characteristics at high voltage.

  As the chain ester, one or more asymmetric chain carbonates selected from methyl ethyl carbonate (MEC), methyl propyl carbonate (MPC), methyl isopropyl carbonate (MIPC), methyl butyl carbonate, and ethyl propyl carbonate, dimethyl One or more symmetrical linear carbonates selected from carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, and dibutyl carbonate, methyl pivalate (MPiv), ethyl pivalate (EPiv), propyl pivalate Preferably, one or more chain carboxylic acid esters selected from the group consisting of (PPiv), methyl propionate (MP), ethyl propionate (EP), methyl acetate (MA), and ethyl acetate (EA) Gerare, two or more is more preferable.

  Among the chain esters, dimethyl carbonate (DMC), methyl ethyl carbonate (MEC), methyl propyl carbonate (MPC), methyl isopropyl carbonate (MIPC), methyl butyl carbonate, methyl propionate (MP), methyl acetate (MA) And a chain ester having a methyl group selected from ethyl acetate (EA) is preferable, and a chain carbonate having a methyl group is particularly preferable.

  Moreover, when using chain carbonate, it is preferable to use 2 or more types. Further, it is more preferable that both a symmetric chain carbonate and an asymmetric chain carbonate are contained, and it is more preferable that the content of the symmetric chain carbonate is more than that of the asymmetric chain carbonate.

  The content of the chain ester is not particularly limited, but it is preferably used in the range of 60 to 90% by volume with respect to the total volume of the nonaqueous solvent. If the content is 60% by volume or more, the viscosity of the non-aqueous electrolyte does not become too high, and if it is 90% by volume or less, the electrical conductivity of the non-aqueous electrolyte decreases and the electrochemical properties at high temperature are low. Since there is little possibility of a fall, it is preferable that it is the said range.

  The volume ratio of the symmetric chain carbonate in the chain carbonate is preferably 51% by volume or more, and more preferably 55% by volume or more. The upper limit is more preferably 95% by volume or less, and further preferably 85% by volume or less. It is particularly preferred that the symmetric chain carbonate contains dimethyl carbonate. The asymmetric chain carbonate preferably has a methyl group, and methyl ethyl carbonate is particularly preferable. The above case is preferable because the electrochemical characteristics at a higher temperature are further improved.

  The ratio between the cyclic carbonate and the chain ester is preferably 10:90 to 45:55, and 15:85 to 40:60, from the viewpoint of improving electrochemical properties at high temperatures. Is more preferable, and 20:80 to 35:65 is particularly preferable.

  Other non-aqueous solvents preferably include one or more lactones selected from the group consisting of γ-butyrolactone (GBL), γ-valerolactone, and α-angelica lactone, and more preferably two or more. .

  The content of the lactone is preferably 5 to 40% by volume with respect to the total volume of the non-aqueous solvent because the high-temperature storage characteristics under high temperature and high voltage can be further improved.

  Nonaqueous solvents are usually used in admixture in order to achieve appropriate physical properties. The combination includes, for example, a combination of a cyclic carbonate and a chain carbonate, a combination of a cyclic carbonate and a chain carboxylic acid ester, a combination of a cyclic carbonate, a chain carbonate and a lactone, and a combination of a cyclic carbonate, a chain carbonate and an ether. A combination or a combination of a cyclic carbonate, a chain carbonate, and a chain carboxylic acid ester is preferable.

In order to further improve the stability of the coating film at a higher temperature, it is preferable to add other additives to the non-aqueous electrolyte.
Specific examples of other additives include the following compounds (A) to (G).

  (A) One or more nitriles selected from the group consisting of acetonitrile, propionitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, and sebaconitrile.

  (B) Consists of methyl isocyanate, ethyl isocyanate, butyl isocyanate, phenyl isocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, 1,4-phenylene diisocyanate, 2-isocyanatoethyl acrylate, and 2-isocyanatoethyl methacrylate. One or more isocyanate compounds selected from the group.

  (C) 2-propynyl methyl carbonate, 2-propynyl acetate, 2-propynyl formate, 2-propynyl methacrylate, 2-propynyl methanesulfonate, 2-propynyl vinylsulfonate, 2- (methanesulfonyloxy) propionate 2- Propynyl, di (2-propynyl) oxalate, methyl 2-propynyl oxalate, ethyl 2-propynyl oxalate, di (2-propynyl) glutarate, 2-butyne-1,4-diyl dimethanesulfonate, 2- One or more triple bond-containing compounds selected from the group consisting of butyne-1,4-diyl diformate and 2,4-hexadiyne-1,6-diyl dimethanesulfonate.

  (D) 1,3-propane sultone, 1,3-butane sultone, 2,4-butane sultone, 1,4-butane sultone, 1,3-propene sultone, 2,2-dioxide-1,2-oxathiolan-4-yl Acetate, or sultone such as 5,5-dimethyl-1,2-oxathiolane-4-one 2,2-dioxide, ethylene sulfite, hexahydrobenzo [1,3,2] dioxathiolane-2-oxide (1,2 -Cyclohexanediol cyclic sulfite), or cyclic sulfites such as 5-vinyl-hexahydro-1,3,2-benzodioxathiol-2-oxide, butane-2,3-diyl dimethanesulfonate, butane -1,4-diyl dimethanesulfonate, or methylenemethane disulfonate One or more S (═O) group-containing compounds selected from the group consisting of vinylsulfone compounds such as acid esters, divinylsulfone, 1,2-bis (vinylsulfonyl) ethane, or bis (2-vinylsulfonylethyl) ether .

  (E) Trimethyl phosphate, tributyl phosphate, and trioctyl phosphate, tris (2,2,2-trifluoroethyl phosphate), bis (2,2,2-trifluoroethyl) methyl phosphate, bis phosphate (2,2,2-trifluoroethyl) ethyl, bis (2,2,2-trifluoroethyl) phosphate 2,2-difluoroethyl, bis (2,2,2-trifluoroethyl) phosphate 2, 2,3,3-tetrafluoropropyl, bis (2,2-difluoroethyl) phosphate 2,2,2-trifluoroethyl, bis (2,2,3,3-tetrafluoropropyl) phosphate 2,2 , 2-trifluoroethyl and phosphoric acid (2,2,2-trifluoroethyl) (2,2,3,3-tetrafluoropropyl) methyl, phosphoric acid tris (1,1,1,3,3,3 -Hexaful Lopropan-2-yl), methyl methylene bisphosphonate, ethyl methylene bisphosphonate, methyl ethylene bisphosphonate, ethyl ethylene bisphosphonate, methyl butylene bisphosphonate, ethyl butylene bisphosphonate, methyl 2- (dimethylphosphoryl) acetate, ethyl 2- ( Dimethylphosphoryl) acetate, methyl 2- (diethylphosphoryl) acetate, ethyl 2- (diethylphosphoryl) acetate, 2-propynyl 2- (dimethylphosphoryl) acetate, 2-propynyl 2- (diethylphosphoryl) acetate, methyl 2- (dimethoxy) Phosphoryl) acetate, ethyl 2- (dimethoxyphosphoryl) acetate, methyl 2- (diethoxyphosphoryl) acetate, ethyl 2- (diethoxyphosphoryl) 1) One or more phosphorus-containing compounds selected from the group consisting of acetate, 2-propynyl 2- (dimethoxyphosphoryl) acetate, 2-propynyl 2- (diethoxyphosphoryl) acetate, methyl pyrophosphate and ethyl pyrophosphate.

  (F) Chain carboxylic anhydrides such as acetic anhydride and propionic anhydride, succinic anhydride, maleic anhydride, 3-allyl succinic anhydride, glutaric anhydride, itaconic anhydride, or 3-sulfo-propionic anhydride Cyclic acid anhydrides such as products.

  (G) A cyclic phosphazene compound such as methoxypentafluorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, phenoxypentafluorocyclotriphosphazene, or ethoxyheptafluorocyclotetraphosphazene.

  Among the above, it is preferable to include at least one selected from the group consisting of (A) nitrile and (B) isocyanate compound, since the high-temperature storage characteristics under high voltage are further improved.

  Among the nitriles (A), one or more nitriles selected from the group consisting of succinonitrile, glutaronitrile, adiponitrile, pimonitrile, suberonitrile, and sebaconitrile are preferable, and succinonitrile, glutaronitrile, adiponitrile, and pimelonitrile are preferable. One or more selected from is more preferable.

  Among the (B) isocyanate compounds, one or more selected from the group consisting of hexamethylene diisocyanate, octamethylene diisocyanate, 2-isocyanatoethyl acrylate, and 2-isocyanatoethyl methacrylate are more preferable.

  The content of the compound (A) is preferably 0.01 to 20% by mass in the non-aqueous electrolyte. In this range, the coating film is sufficiently formed without becoming too thick, and the stability of the coating film at a higher temperature is further increased. The content is more preferably 0.1% by mass or more in the nonaqueous electrolytic solution, further preferably 1% by mass or more, and the upper limit thereof is more preferably 15% by mass or less, and further preferably 10% by mass or less.

  The content of the compound (B) is preferably 0.01 to 7% by mass in the non-aqueous electrolyte. In this range, the coating film is sufficiently formed without becoming too thick, and the stability of the coating film at a higher temperature is further increased. The content is more preferably 0.05% by mass or more, more preferably 0.1% by mass or more in the non-aqueous electrolyte, and the upper limit thereof is more preferably 5% by mass or less, and further preferably 3% by mass or less. .

  (C) a triple bond-containing compound, (D) a cyclic or chain S (═O) group-containing compound selected from the group consisting of sultone, cyclic sulfite, sulfonic acid ester, and vinyl sulfone, (E) It is preferable to include a phosphorus-containing compound, (F) a cyclic acid anhydride, or (G) a cyclic phosphazene compound because the stability of the coating film at a higher temperature is further improved.

  Examples of the (C) triple bond-containing compound include 2-propynyl methyl carbonate, 2-propynyl methacrylate, 2-propynyl methanesulfonate, 2-propynyl vinylsulfonate, 2-propynyl 2- (methanesulfonyloxy) propionate, One or more selected from the group consisting of di (2-propynyl) oxalate, methyl 2-propynyl oxalate, ethyl 2-propynyl oxalate, and 2-butyne-1,4-diyl dimethanesulfonate is preferred, and 2-propynyl methanesulfonate 1 selected from the group consisting of 2-propynyl vinyl sulfonate, 2-propynyl 2- (methanesulfonyloxy) propionate, di (2-propynyl) oxalate, and 2-butyne-1,4-diyl dimethanesulfonate. More is more preferable.

  The (D) cyclic or chain S (═O) group-containing compound selected from sultone, cyclic sulfite, sulfonic acid ester, and vinyl sulfone (however, a triple bond-containing compound is not included) is preferably used.

  Examples of the cyclic S (═O) group-containing compound include 1,3-propane sultone, 1,3-butane sultone, 1,4-butane sultone, 2,4-butane sultone, 1,3-propene sultone, 2,2- Dioxido-1,2-oxathiolan-4-yl acetate, 5,5-dimethyl-1,2-oxathiolan-4-one 2,2-dioxide, methylene methanedisulfonate, ethylene sulfite, and 4- (methylsulfonylmethyl) ) -1,3,2-dioxathiolane One or more selected from the group consisting of 2-oxides is preferred.

  Examples of the chain-containing S (═O) group-containing compound include butane-2,3-diyl dimethanesulfonate, butane-1,4-diyl dimethanesulfonate, dimethylmethane disulfonate, pentafluorophenyl methanesulfonate, and divinyl. One or more types selected from the group consisting of sulfone and bis (2-vinylsulfonylethyl) ether are preferred.

  Among the cyclic or chain S (= O) group-containing compounds, 1,3-propane sultone, 1,4-butane sultone, 2,4-butane sultone, 2,2-dioxide-1,2-oxathiolane-4- Selected from the group consisting of yl acetate and 5,5-dimethyl-1,2-oxathiolane-4-one 2,2-dioxide, butane-2,3-diyl dimethanesulfonate, pentafluorophenyl methanesulfonate, and divinylsulfone One or more of these are more preferred.

  Examples of the (E) phosphorus-containing compound include tris phosphate (2,2,2-trifluoroethyl), tris phosphate (1,1,1,3,3,3-hexafluoropropan-2-yl), Methyl 2- (dimethylphosphoryl) acetate, ethyl 2- (dimethylphosphoryl) acetate, methyl 2- (diethylphosphoryl) acetate, ethyl 2- (diethylphosphoryl) acetate, 2-propynyl 2- (dimethylphosphoryl) acetate, 2-propynyl 2- (diethylphosphoryl) acetate, methyl 2- (dimethoxyphosphoryl) acetate, ethyl 2- (dimethoxyphosphoryl) acetate, methyl 2- (diethoxyphosphoryl) acetate, ethyl 2- (diethoxyphosphoryl) acetate, 2-propynyl 2 -(Dimethoxypho Sphoryl) acetate or 2-propynyl 2- (diethoxyphosphoryl) acetate is preferred, and tris phosphate (2,2,2-trifluoroethyl), tris phosphate (1,1,1,3,3,3- Hexafluoropropan-2-yl), ethyl 2- (diethylphosphoryl) acetate, 2-propynyl 2- (dimethylphosphoryl) acetate, 2-propynyl 2- (diethylphosphoryl) acetate, ethyl 2- (diethoxyphosphoryl) acetate, 2-propynyl 2- (dimethoxyphosphoryl) acetate or 2-propynyl 2- (diethoxyphosphoryl) acetate is more preferred.

  The (F) cyclic acid anhydride is preferably succinic anhydride, maleic anhydride, or 3-allyl succinic anhydride, and more preferably succinic anhydride or 3-allyl succinic anhydride.

  The cyclic phosphazene compound (G) is preferably a cyclic phosphazene compound such as methoxypentafluorocyclotriphosphazene, ethoxypentafluorocyclotriphosphazene, or phenoxypentafluorocyclotriphosphazene. More preferred is triphosphazene.

  The content of the compounds (C) to (G) is preferably 0.001 to 5% by mass in the non-aqueous electrolyte. In this range, the coating film is sufficiently formed without becoming too thick, and the stability of the coating film at a higher temperature is further increased. The content is more preferably 0.01% by mass or more, more preferably 0.1% by mass or more in the non-aqueous electrolyte, and the upper limit thereof is more preferably 3% by mass or less, and further preferably 2% by mass or less. .

Further, for the purpose of further improving the stability of the coating film at high temperature, the non-aqueous electrolyte further includes a lithium salt having an oxalic acid skeleton, a lithium salt having a phosphoric acid skeleton, and lithium having an S (═O) group. It is preferable to include one or more lithium salts selected from salts.
Specific examples of lithium salts include lithium bis (oxalato) borate (LiBOB), lithium difluoro (oxalato) borate (LiDFOB), lithium tetrafluoro (oxalato) phosphate (LiTFOP), and lithium difluorobis (oxalato) phosphate (LiDFOP). Lithium salt having at least one oxalic acid skeleton selected from Lithium salt having phosphoric acid skeleton such as LiPO ₂ F ₂ and Li ₂ PO ₃ F, lithium trifluoro ((methanesulfonyl) oxy) borate (LiTFMSB), lithium Pentafluoro ((methanesulfonyl) oxy) phosphate (LiPFMSP), lithium methyl sulfate (LMS), lithium ethyl sulfate (LES), lithium 2,2,2-tri Le Oro ethylsulfate (LFES), and lithium salt preferably include having one or more S (= O) group selected from the group consisting of _{FSO 3 Li, LiBOB, LiDFOB,} LiTFOP, LiDFOP, LiPO 2 F 2, It is more preferable to include at least one lithium salt selected from the group consisting of LiTFMSB, LMS, LES, LFES, and FSO ₃ Li.

  The proportion of the lithium salt in the non-aqueous solvent is preferably 0.001M or more and 0.5M or less. Within this range, the effect of improving electrochemical characteristics over a wide temperature range is further exhibited. Preferably it is 0.01M or more, More preferably, it is 0.03M or more, Most preferably, it is 0.04M or more. The upper limit is more preferably 0.4M or less, and particularly preferably 0.2M or less. (However, M represents mol / L.)

(Electrolyte salt)
Preferred examples of the electrolyte salt used in the present invention include the following lithium salts.
Examples of lithium salts include inorganic lithium salts such as LiPF ₆ , LiBF ₄ , and LiClO ₄ , LiN (SO ₂ F) ₂ (abbreviated as FSI), LiN (SO ₂ CF ₃ ) ₂ (abbreviated as TFSI), LiN (SO ₂ C ₂ F ₅ ) ₂ , LiCF ₃ SO ₃ , LiC (SO ₂ CF ₃ ) ₃ , LiPF ₄ (CF ₃ ) ₂ , LiPF ₃ (C ₂ F ₅ ) ₃ , LiPF ₃ (CF ₃ ) ₃ Lithium salt containing a chain-like fluorinated alkyl group such as LiPF ₃ (iso-C ₃ F ₇ ) ₃ , LiPF ₅ (iso-C ₃ F ₇ ), or (CF ₂ ) ₂ (SO ₂ ) ₂ NLi And a lithium salt having a cyclic fluorinated alkylene chain such as (CF ₂ ) ₃ (SO ₂ ) ₂ NLi, and the like, and at least one lithium salt selected from these is preferred. It is mentioned appropriately and these 1 type, or 2 or more types can be mixed and used.

Among these, one or two selected from LiPF ₆ , LiBF ₄ , LiN (SO ₂ CF ₃ ) ₂ [TFSI], LiN (SO ₂ C ₂ F ₅ ) ₂ , and LiN (SO ₂ F) ₂ [FSI]. More than seeds are preferred, and LiPF ₆ is most preferred. The concentration of the lithium salt is usually preferably 0.3 M or more, more preferably 0.7 M or more, and further preferably 1.1 M or more with respect to the non-aqueous solvent. Moreover, the upper limit is preferably 2.5M or less, more preferably 2.0M or less, and further preferably 1.6M or less.

Further, a suitable combination of these lithium salts includes LiPF ₆ , and at least one selected from LiBF ₄ , LiN (SO ₂ CF ₃ ) ₂ [TFSI], and LiN (SO ₂ F) ₂ [FSI]. The case where the lithium salt of the seed is contained in the non-aqueous electrolyte is preferable, and the proportion of the lithium salt other than LiPF _{6 in the} non-aqueous solvent is 0.001M or more when the battery is used at a high temperature It is preferable that the effect of improving the electrochemical characteristics is 1.0 M or less because there is little concern that the effect of improving the electrochemical characteristics when the battery is used at a high temperature is reduced. Preferably it is 0.01M or more, Especially preferably, it is 0.03M or more, Most preferably, it is 0.04M or more. The upper limit is preferably 0.8M or less, more preferably 0.6M or less, and particularly preferably 0.4M or less.

[Production of non-aqueous electrolyte]
The non-aqueous electrolyte of the present invention is, for example, a mixture of the non-aqueous solvent described above, and the tertiary carboxylic acid ester represented by the general formula (I) with respect to the electrolyte salt and the non-aqueous electrolyte. Can be obtained.
At this time, it is preferable that the compound added to the non-aqueous solvent and the non-aqueous electrolyte to be used is one that is purified in advance and has as few impurities as possible within a range that does not significantly reduce the productivity.

  The electricity storage device of the present invention can be obtained, for example, by including a positive electrode, a negative electrode, and the non-aqueous electrolyte.

  The nonaqueous electrolytic solution of the present invention can be used in the following first to fourth power storage devices, and not only a liquid but also a gelled one can be used as the nonaqueous electrolyte. Furthermore, the nonaqueous electrolytic solution of the present invention can be used for a solid polymer electrolyte. In particular, it is preferably used for the first electricity storage device (that is, for a lithium battery) or the fourth electricity storage device (that is, for a lithium ion capacitor) that uses a lithium salt as an electrolyte salt, and is used for a lithium battery. More preferably, it is more preferably used for a lithium secondary battery.

[First power storage device (lithium battery)]
The lithium secondary battery which is the 1st electrical storage device of this invention consists of the said non-aqueous electrolyte in which electrolyte salt is melt | dissolved in the positive electrode, the negative electrode, and the non-aqueous solvent. Components other than the non-aqueous electrolyte, such as a positive electrode and a negative electrode, can be used without particular limitation.
For example, as a positive electrode active material for a lithium secondary battery, a composite metal oxide with lithium containing one or more selected from the group consisting of cobalt, manganese, and nickel is used. These positive electrode active materials can be used alone or in combination of two or more.
Examples of such lithium composite metal oxides include LiCoO ₂ , LiCo _1-x M _x O ₂ (where M is Sn, Mg, Fe, Ti, Al, Zr, Cr, V, Ga, Zn, and One or more elements selected from Cu, 0.001 ≦ x ≦ 0.05), LiMn ₂ O ₄ , LiNiO ₂ , LiCo _1-x Ni _x O ₂ (0.01 <x <1), LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , LiNi _0.8 Mn _0.1 Co _0.1 O ₂ , LiNi _0.8 Co Selected from solid solution of _0.15 Al _0.05 O ₂ , Li ₂ MnO ₃ and LiMO ₂ (M is a transition metal such as Co, Ni, Mn, Fe, etc.) and LiNi _0.5 Mn _1.5 O ₄ 1 or more types are preferably mentioned, and 2 types Above is more preferable. Moreover, LiCoO ₂ and LiMn ₂ O _4, LiCoO ₂ and LiNiO _2, may be used in combination as LiMn ₂ O ₄ and LiNiO _2.

When a lithium composite metal oxide that operates at a high charge voltage is used, the storage characteristics at high temperature and high voltage are likely to deteriorate due to the reaction with the electrolyte during charge storage, but in the lithium secondary battery according to the present invention, these electrical properties are reduced. A decrease in chemical properties can be suppressed.
In particular, in the case of a positive electrode active material containing Ni, the catalytic action of Ni causes decomposition of the nonaqueous solvent on the surface of the positive electrode, which causes a decrease in capacity retention rate and an increase in gas generation under a high temperature and high voltage storage environment. The lithium secondary battery according to the present invention is preferable because it can suppress a decrease in these electrochemical characteristics. In particular, when the positive electrode active material in which the ratio of the atomic concentration of Ni to the atomic concentration of all transition metal elements in the positive electrode active material exceeds 30 atomic% is used, the above effect is significant, and more preferably 50 atomic% or more. 75% or more is particularly preferable. Specifically, LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , LiNi _0.8 Mn _0.1 Co _0.1 O ₂ , Preferable examples include LiNi _0.5 Mn _1.5 O ₄ and LiNi _0.8 Co _0.15 Al _0.05 O ₂ .

Furthermore, lithium-containing olivine-type phosphate can also be used as the positive electrode active material. In particular, a lithium-containing olivine-type phosphate containing at least one selected from iron, cobalt, nickel and manganese is preferable. Specific examples thereof include LiFePO ₄ , LiCoPO ₄ , LiNiPO ₄ , LiMnPO _{4 and the} like.
Some of these lithium-containing olivine-type phosphates may be substituted with other elements, and some of iron, cobalt, nickel, and manganese are replaced with Co, Mn, Ni, Mg, Al, B, Ti, V, and Nb. , Cu, Zn, Mo, Ca, Sr, W and Zr can be substituted with one or more elements selected from these, or can be coated with a compound or carbon material containing these other elements. Among these, LiFePO ₄ or LiMnPO ₄ is preferable.
Moreover, lithium containing olivine type | mold phosphate can also be mixed with the said positive electrode active material, for example, and can be used.

As the positive electrode for lithium primary _{battery, CuO, Cu 2 O, Ag} 2 O, Ag 2 CrO 4, CuS, CuSO 4, TiO 2, TiS 2, SiO 2, SnO, V 2 O 5, V 6 O 12 , VO _x , Nb ₂ O ₅ , Bi ₂ O ₃ , Bi ₂ Pb ₂ O ₅ , Sb ₂ O ₃ , CrO ₃ , Cr ₂ O ₃ , MoO ₃ , WO ₃ , SeO ₂ , MnO ₂ , Mn ₂ O ₃ , Fe ₂ O ₃ , FeO, Fe ₃ O ₄ , Ni ₂ O ₃ , NiO, CoO ₃ , CoO and other oxides of one or more metal elements or chalcogen compounds, SO ₂ , SOCl _2, etc. Examples thereof include sulfur compounds, and fluorocarbon (fluorinated graphite) represented by the general formula (CF _x ) _n . Among these, MnO ₂ , V ₂ O ₅ , graphite fluoride and the like are preferable.

  The conductive agent for the positive electrode is not particularly limited as long as it is an electron conductive material that does not cause a chemical change. Examples thereof include graphite such as natural graphite (flaky graphite and the like) and artificial graphite, carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black and thermal black. Further, graphite and carbon black may be appropriately mixed and used. 1-10 mass% is preferable and, as for the addition amount to the positive mix of a electrically conductive agent, 2-5 mass% is especially preferable.

For the positive electrode, the positive electrode active material is made of a conductive agent such as acetylene black or carbon black, and polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), a copolymer of styrene and butadiene (SBR), acrylonitrile and butadiene. Mixing with a binder such as copolymer (NBR), carboxymethyl cellulose (CMC), ethylene propylene diene terpolymer, etc., and adding a high boiling point solvent such as 1-methyl-2-pyrrolidone to knead and mix Then, after applying this positive electrode mixture to an aluminum foil or a stainless steel lath plate as a current collector, drying and press-molding, it was vacuumed at a temperature of about 50 ° C. to 250 ° C. for about 2 hours. It can produce by heat-processing with.
The density of the part except the collector of the positive electrode is usually at 1.5 g / cm ³ or more, for further increasing the capacity of the battery, it is preferably 2 g / cm ³ or more, more preferably, 3 g / cm ³ It is above, More preferably, it is 3.6 g / cm ³ or more. The upper limit is preferably 4 g / cm ³ or less.

Examples of the negative electrode active material for a lithium secondary battery include lithium metal, lithium alloy, and a carbon material capable of occluding and releasing lithium (easily graphitized carbon and a (002) plane spacing of 0.37 nm or more). Non-graphitizable carbon, graphite with (002) plane spacing of 0.34 nm or less, etc.], tin (single), tin compound, silicon (single), silicon compound, lithium titanate such as Li ₄ Ti ₅ O ₁₂ A compound etc. can be used individually by 1 type or in combination of 2 or more types.
Among these, it is more preferable to use a highly crystalline carbon material such as artificial graphite or natural graphite in terms of the ability to occlude and release lithium ions, and the plane spacing (d ₀₀₂ ) of the lattice plane ( ₀₀₂ ) is 0. It is particularly preferable to use a carbon material having a graphite-type crystal structure of 340 nm (nanometer) or less, particularly 0.335 to 0.337 nm.
A mechanical action such as compression force, friction force, shear force, etc. is repeatedly applied to artificial graphite particles having a massive structure in which a plurality of flat graphite fine particles are assembled or bonded non-parallel to each other, for example, scaly natural graphite particles, Using graphite particles that have been subjected to spheroidization treatment, the density of the portion excluding the current collector of the negative electrode can be obtained from X-ray diffraction measurement of the negative electrode sheet when pressed to a density of 1.5 g / cm ³ or more. When the ratio I (110) / I (004) of the peak intensity I (110) of the (110) plane of the graphite crystal to the peak intensity I (004) of the (004) plane is 0.01 or more, the graphite crystal It is preferable because the metal elution amount is improved and the charge storage characteristics are improved, more preferably 0.05 or more, and still more preferably 0.1 or more. Moreover, since it may process too much and crystallinity may fall and the discharge capacity of a battery may fall, 0.5 or less is preferable and 0.3 or less is more preferable.
In addition, it is preferable that the highly crystalline carbon material (core material) is coated with a carbon material that is less crystalline than the core material because the storage characteristics at high temperature and high voltage are further improved. The crystallinity of the coating carbon material can be confirmed by TEM.
When a highly crystalline carbon material is used, it tends to react with the non-aqueous electrolyte during charge storage at high temperature and high voltage, reducing the capacity retention rate and increasing gas generation. In the secondary battery, these characteristics are good.

  Examples of the metal compound capable of inserting and extracting lithium as the negative electrode active material include Si, Ge, Sn, Pb, P, Sb, Bi, Al, Ga, In, Ti, Mn, Fe, Co, Ni, and Cu. , Zn, Ag, Mg, Sr, Ba, and other compounds containing at least one metal element. These metal compounds may be used in any form such as a simple substance, an alloy, an oxide, a nitride, a sulfide, a boride, and an alloy with lithium, but any of a simple substance, an alloy, an oxide, and an alloy with lithium. Is preferable because the capacity can be increased. Among these, those containing at least one element selected from Si, Ge and Sn are preferable, and those containing at least one element selected from Si and Sn are particularly preferable because the capacity of the battery can be increased.

The negative electrode is kneaded using the same conductive agent, binder, and high-boiling solvent as in the production of the positive electrode, and then the negative electrode mixture is applied to the copper foil of the current collector. After being dried and pressure-molded, it can be produced by heat treatment under vacuum at a temperature of about 50 ° C. to 250 ° C. for about 2 hours.
The density of the portion excluding the current collector of the negative electrode is usually 1.1 g / cm ³ or more, and is preferably 1.5 g / cm ³ or more, particularly preferably 1.7 g in order to further increase the capacity of the battery. / Cm ³ or more. The upper limit is preferably 2 g / cm ³ or less.

  Moreover, lithium metal or a lithium alloy is mentioned as a negative electrode active material for lithium primary batteries.

The structure of the lithium battery is not particularly limited, and a coin-type battery, a cylindrical battery, a square battery, a laminated battery, or the like having a single-layer or multi-layer separator can be applied.
Although it does not restrict | limit especially as a separator for batteries, The single layer or laminated | stacked microporous film, woven fabric, a nonwoven fabric, etc. of polyolefin, such as a polypropylene and polyethylene, can be used.

  The lithium secondary battery in the present invention is excellent in high-temperature cycle characteristics even when the end-of-charge voltage is 4.2 V or higher, particularly 4.3 V or higher, and also has good characteristics at 4.4 V or higher. The end-of-discharge voltage is usually 2.8 V or higher, and further 2.5 V or higher, but the lithium secondary battery in the present invention can be 2.0 V or higher. Although it does not specifically limit about an electric current value, Usually, it uses in the range of 0.1-30C. Moreover, the lithium battery in this invention can be charged / discharged at -40-100 degreeC, Preferably it is -10-80 degreeC.

  In the present invention, as a countermeasure against an increase in the internal pressure of the lithium battery, a method of providing a safety valve on the battery lid or cutting a member such as a battery can or a gasket can be employed. Further, as a safety measure for preventing overcharge, the battery lid can be provided with a current interruption mechanism that senses the internal pressure of the battery and interrupts the current.

[Second power storage device (electric double layer capacitor)]
The 2nd electrical storage device of this invention is an electrical storage device which stores the energy using the electric double layer capacity | capacitance of electrolyte solution and an electrode interface including the non-aqueous electrolyte of this invention. An example of the present invention is an electric double layer capacitor. The most typical electrode active material used for this electricity storage device is activated carbon. Double layer capacity increases roughly in proportion to surface area.

[Third power storage device]
The 3rd electrical storage device of this invention is an electrical storage device which stores the energy using the dope / dedope reaction of an electrode including the non-aqueous electrolyte of this invention. Examples of the electrode active material used in this power storage device include metal oxides such as ruthenium oxide, iridium oxide, tungsten oxide, molybdenum oxide, and copper oxide, and π-conjugated polymers such as polyacene and polythiophene derivatives. Capacitors using these electrode active materials can store energy associated with electrode doping / dedoping reactions.

[Fourth storage device (lithium ion capacitor)]
The 4th electrical storage device of this invention is an electrical storage device which stores the energy using the intercalation of the lithium ion to carbon materials, such as a graphite which is a negative electrode, containing the nonaqueous electrolyte solution of this invention. It is called a lithium ion capacitor (LIC). Examples of the positive electrode include those using an electric double layer between an activated carbon electrode and an electrolytic solution, and those using a π-conjugated polymer electrode doping / dedoping reaction. The electrolytic solution contains at least a lithium salt such as LiPF ₆ .

[Compound of the present invention]
The compound which is a novel substance of the present invention is represented by the following general formulas (VII) to (IX).

(In the formula, R ^{61 to} R ⁶⁷ are each independently synonymous with R ^{11 to} R ¹⁷ defined in general formula (II).)

(In the formula, R ^{71 to} R ⁷⁷ each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an OC (═O) R ²⁹ group, OP ( ═O) (OEt) ₂ group, P (═O) (OEt) ₂ group, or OS (═O) ₂ R ³⁰ group, R ^{28 to} R ³⁰ are alkyl groups having 1 to 4 carbon atoms, carbon number A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms, except that all of R ^{71 to} R ⁷⁷ are hydrogen atoms.

(In the formula, R ^{81 to} R ⁸⁷ are each independently synonymous with R ^{51 to} R ⁵⁷ defined in general formula (VI).)

In the compound represented by the general formula (VII), the substituents R ^{61 to} R ⁶⁷ are each independently synonymous with R ^{11 to} R ¹⁷ in the general formula (II), and thus the description thereof is omitted here.

  Specific examples of the compound represented by the general formula (VII) include compounds A2 and A18 to A34 described in paragraphs [0038] and [0039].

In the compound represented by the general formula (VIII), the substituents R ^{71 to} R ⁷⁷ are each independently synonymous with the substituents in R ^{21 to} R ²⁷ defined in the general formula (III). Omitted.

  Specific compounds represented by general formula (VIII) are compounds B13 to B20 described in paragraph [0048].

In the compound represented by the general formula (IX), the substituents R ^{81 to} R ⁸⁷ are each independently synonymous with R ^{51 to} R ⁵⁷ in the general formula (VI), and thus the description thereof is omitted here.

  Specific compounds represented by the general formula (IX) are compounds E2, E13 to E19 described in paragraph [0072].

  In the field of non-aqueous electrolytes and power storage devices using the same, the compound of the present invention is incorporated into non-aqueous electrolytes, and the storage characteristics at high temperatures and high voltages under high temperatures, which is the subject of the present invention, particularly gas It is a useful compound capable of obtaining a nonaqueous electrolytic solution that improves the effect of suppressing generation, and an electricity storage device including the nonaqueous electrolytic solution.

  The compound represented by the general formula (VII) of the present invention can be synthesized by the following methods, but is not limited to these methods.

(A) A method of reacting a sulfolane compound with a base and diethyl chlorophosphate (hereinafter also referred to as “method (a)”).
(B) A method in which a 2-halogenated sulfolane compound and triethyl phosphite are reacted (hereinafter also referred to as “method (b)”).

[Method a]
Preferred examples of the base used in the method a include organometallic reagents such as n-butyllithium, lithium diisopropylamide, sodium hydride, ethylmagnesium bromide, or lithium hexamethyldisilazide. It is 0.8-3 mol with respect to 1 mol, Preferably it is 0.9-2 mol, More preferably, it is 1-1.5 mol.
Preferable examples of the solvent include ethers such as tetrahydrofuran, diethyl ether, and dioxane, and aromatics such as toluene and xylene. The amount to be used is preferably 1 part by mass to 100 parts by mass, more preferably 10 parts by mass to 80 parts by mass with respect to 1 part by mass of the sulfolane compound.
As the reaction temperature and operation procedure, it is preferable to drop a base between −78 ° C. and 0 ° C. and then add diethyl chlorophosphate dropwise at 0 ° C. to around room temperature with respect to the sulfolane compound and the solvent. The amount of diethyl chlorophosphate used is 0.8 to 3 moles, preferably 0.9 to 2 moles, and more preferably 1 to 1.5 moles.

[Method b]
The 2-halogenated sulfolane compound used in the method b can be obtained by a known method described in US Pat. No. 2,656,362. This 2-halogenated sulfolane compound can be reacted with triethyl phosphite in the presence or absence of a solvent. In the case of using a solvent, although not particularly limited, ethers such as tetrahydrofuran, diethyl ether or dioxane, esters such as dimethyl carbonate or ethyl acetate, and aromatics such as toluene or xylene are preferable. The amount of triethyl phosphite used is 0.8 to 3 mol, preferably 0.9 to 2 mol, and more preferably 1 to 1.5 mol. As an operation procedure, the halogenated sulfolane compound can be reacted dropwise at 0 ° C to 200 ° C, preferably 30 ° C to 180 ° C, more preferably 70 ° C to 150 ° C.

  The compound represented by the general formula (VIII) of the present invention can be synthesized by the following methods, but is not limited to these methods.

  (C) A method of reacting a 3-halogenated sulfolane compound and triethyl phosphite (hereinafter also referred to as “method (c)”).

[Method c]
The 3-halogenated sulfolane compound used in the method c can be obtained by a known method described in US Pat. No. 4,656,289. This 23-halogenated sulfolane compound can be reacted with triethyl phosphite in the presence or absence of a solvent. In the case of using a solvent, although not particularly limited, ethers such as tetrahydrofuran, diethyl ether or dioxane, esters such as dimethyl carbonate or ethyl acetate, and aromatics such as toluene or xylene are preferable. The amount of triethyl phosphite used is 0.8 to 3 mol, preferably 0.9 to 2 mol, and more preferably 1 to 1.5 mol. As an operation procedure, the halogenated sulfolane compound can be reacted dropwise at 0 ° C. to 200 ° C., preferably 30 to 180 ° C., more preferably 70 ° C. to 150 ° C.

  The compound represented by the general formula (IX) of the present invention can be synthesized by the following methods, but is not limited to these methods.

  (D) A method in which a 3-hydroxysulfolane compound is reacted with a base and diethyl chlorophosphate (hereinafter also referred to as “method d”).

[D method]
The 3-hydroxysulfolane compound used in the method d is described in Langmuir, 2016, vol. 32, # 3, p. 765-771 and the like. Examples of the base used in the method d include organometallic reagents such as n-butyllithium, lithium diisopropylamide, sodium hydride, ethylmagnesium bromide or lithium hexamethyldisilazide, or triethylamine, pyridine, or 4-dimethylaminopyridine. The amount used is 0.8 to 3 mol, preferably 0.9 to 2 mol, more preferably 1 to 1.5 mol, per 1 mol of the sulfolane compound.
Solvents include ethers such as tetrahydrofuran, diethyl ether or dioxane, esters such as dimethyl carbonate or ethyl acetate, halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, or chloroform, or aromatics such as toluene or xylene. A family is preferably mentioned. The amount to be used is preferably 1 part by mass to 100 parts by mass, more preferably 10 parts by mass to 80 parts by mass with respect to 1 part by mass of the sulfolane compound.
As the reaction temperature and the operation procedure, it is preferable to add dropwise a base between −78 ° C. and 0 ° C. to the 3-hydroxysulfolane compound and the solvent, and then add diethyl chlorophosphate dropwise at around 0 ° C. to near room temperature. The amount of diethyl chlorophosphate used is 0.8 to 3 moles, preferably 0.9 to 2 moles, and more preferably 1 to 1.5 moles.

(Synthesis example)
Hereinafter, although the synthesis example of the compound used by this invention is shown, it is not limited to these synthesis examples.

Synthesis Example 1 [Synthesis of diethyl (1,1-dioxidetetrahydrothiophen-2-yl) phosphonate (Compound A2)]
1,1-dioxidetetrahydrothiophene (10.00 g, 83.2 mmol) and THF (100 mL) were mixed in a 500 mL four-necked flask at room temperature, and cooled to −78 ° C. in a dry ice-acetone bath. A 1.6 M normal butyl lithium-hexane solution (54.6 mL) was added dropwise over 15 minutes, and the mixture was stirred at -78 ° C for 20 minutes. Thereafter, diethyl chlorophosphate (15.07 g, 87.4 mmol) was added dropwise over 15 minutes, and the mixture was warmed to room temperature and stirred for 3 hours. After completion of the reaction, 40 ml of water was added, extracted three times with 40 mL of ethyl acetate, and the organic layer washed with 40 mL of saturated brine was dried over magnesium sulfate, concentrated and purified by column chromatography to obtain 2.96 g of a colorless oil. It was. (Yield: 13%)
About the obtained diethyl (1,1-dioxide tetrahydrothiophen-2-yl) phosphonate, < ¹ > H-NMR measurement was performed and the structure was confirmed. The results are shown below.
¹ H-NMR (400 MHz, CDCl 3): δ 4.34-4.18 (4H, m), 3.45-3.36 (1H, m), 3.17-3.13 (2H, m), 2 .56-2.31 (3H, m), 2.22-2.10 (1H, m), 1.40-1.35 (6H, t, J = 7.2 Hz).

Synthesis Example 2 [Synthesis of 4- (diethoxyphosphoryl) 1,1-dioxidetetrahydrothiophen-3-yl acetate (Compound B18)]
A solution of 4-bromo-1,1-dioxidetetrahydrothiophen-3-yl acetate (10.48 g, 40.8 mmol) and toluene (40 mL) in a 100 mL four-neck flask and triethyl phosphite (6.77 g, 40.8 mmol) Was added at room temperature, followed by stirring with heating at 120 ° C. for 4 h. After concentrating the reaction solution, the obtained solid was recrystallized with DMC / hexane = 1/1 to obtain 4.01 g of a white solid. (Yield: 31%)
The obtained 4- (diethoxyphosphoryl) 1,1-dioxidetetrahydrothiophen-3-yl acetate was subjected to ¹ H-NMR measurement to confirm its structure. The results are shown below. (Yield: 13%)
¹ H-NMR (400 MHz, CDCl 3): δ 5.30-5.28 (2H, m), 4.21-4.14 (4H, q, J = 7.2 Hz), 3.33-3.28 ( 2H, m), 3.27-3.22 (2H, m), 1.62 (3H, s), 1.34 (6H, t, J = 7.2 Hz).

Synthesis Example 3 [Synthesis of 1,1-dioxidetetrehydrothiophen-3-yl diethylphosphate (Compound E2)]
In a 500 mL four-necked flask, 3-hydroxytetrahydrothiophene-1,1-dioxide (4.33 g, 31.8 mmol), 4-dimethylaminopyridine (0.388 g, 3.20 mmol), triethylamine (3.54 g, 35.0 mmol). ), And 200 mL of ethyl acetate were mixed at room temperature, and then cooled to 10 ° C. in an ice bath. Thereafter, diethyl chlorophosphate (5.76 g, 33.4 mmol) was added dropwise over 15 minutes, the temperature was raised to room temperature, and the mixture was stirred for 6 hours. After completion of the reaction, 10 mL of water was added for liquid separation, and the organic layer washed with 10 mL of water was concentrated and purified by column chromatography to obtain 2.45 g of a colorless oil. (Yield: 28%)
The obtained 1,1-dioxidetetrehydrothiophen-3-yl diethylphosphate was subjected to ¹ H-NMR measurement to confirm its structure. The results are shown below.
¹ H-NMR (400 MHz, CDCl 3): δ 5.23-5.17 (1H, m), 4.17-4.09 (4H, m), 3.41-3.27 (3H, m), 3 .18-3.12 (1H, m), 2.62-2.54 (1H, m), 2.54-2.43 (1H, m), 1.35 (6H, t, J = 7. 1 Hz).

  Examples of the electrolytic solution using the compound of the present invention are shown below, but the present invention is not limited to these examples.

Examples 1-22, Comparative Examples 1-4
[Production of lithium ion secondary battery]
LiNi _0.5 Co _0.2 Mn _0.3 O ₂ ; 94% by mass, acetylene black (conducting agent); 3% by mass are mixed in advance, and polyvinylidene fluoride (binder); In addition to the solution dissolved in -2-pyrrolidone, the mixture was mixed to prepare a positive electrode mixture paste. This positive electrode mixture paste was applied to one side of an aluminum foil (current collector), dried and pressurized, and cut into a predetermined size to produce a belt-like positive electrode sheet. The density of the portion excluding the current collector of the positive electrode was 3.6 g / cm ³ . Further, artificial graphite (d ₀₀₂ = 0.335 nm, negative electrode active material); 90% by mass, acetylene black (conductive agent); 5% by mass were mixed, and polyvinylidene fluoride (binder); A negative electrode mixture paste was prepared by adding to and mixing with the solution dissolved in methyl-2-pyrrolidone. This negative electrode mixture paste was applied to one side of a copper foil (current collector), dried and pressurized, and cut into a predetermined size to produce a negative electrode sheet. The density of the portion excluding the current collector of the negative electrode was 1.5 g / cm ³ . As a result of X-ray diffraction measurement using this electrode sheet, the ratio of the peak intensity I (110) of the (110) plane of the graphite crystal to the peak intensity I (004) of the (004) plane [I (110) / I (004)] was 0.1.
A heat-resistant layer (3 μm) having boehmite particles and an ethylene-vinyl acetate copolymer is formed on both sides of a laminated microporous film having a three-layer structure of polypropylene (3 μm) / polyethylene (5 μm) / polypropylene (3 μm). A separator having a thickness of 17 μm was produced.
The positive electrode sheet, separator, and negative electrode sheet obtained above were laminated in order, and a non-aqueous electrolyte solution having the composition described in Tables 1 and 2 was added to produce a laminate type battery.

[Discharge capacity maintenance ratio after storage at high temperature]
<Initial discharge capacity>
Using the laminated battery produced by the above method, in a constant temperature bath at 25 ° C., it is charged with a constant current and a constant voltage of 1 C for 3 hours to a final voltage of 4.4 V, and reaches a final voltage of 2.75 V under a constant current of 1 C. After discharging, the initial discharge capacity was determined.
<High-temperature charge storage test>
Next, this laminate battery was charged in a constant temperature bath at 60 ° C. with a constant current of 1 C and a constant voltage for 3 hours to a final voltage of 4.4 V, and stored for 5 days while being held at 4.4 V. Then, it put into the thermostat of 25 degreeC, and discharged once to the final voltage 2.75V under the constant current of 1C.
<Discharge capacity after storage at high temperature>
Thereafter, the discharge capacity after storage at high temperature charge was determined in the same manner as the measurement of the initial discharge capacity.
<Capacity maintenance rate after storage at high temperature>
The capacity retention rate after storage at high temperature was determined by the following formula.
Discharge capacity retention rate after storage at high temperature (%) = (discharge capacity after storage at high temperature / initial discharge capacity) × 100
[Evaluation of gas generation after storage at high temperature]
The amount of gas generated after storage at high temperature was measured by the Archimedes method. The relative amount of gas generated was examined on the basis of the amount of gas generated in Comparative Example 1 as 100%.
In addition, Table 1 and Table 2 show battery manufacturing conditions and battery characteristics.

Example 23 and Comparative Example 5
A positive electrode sheet was produced using LiNi _0.5 Mn _1.5 O ₄ (positive electrode active material) instead of the positive electrode active material used in Example 1 and Comparative Example 1. LiNi _0.5 Mn _1.5 O ₄ coated with amorphous carbon; 94% by mass, acetylene black (conductive agent); 3% by mass are mixed in advance and polyvinylidene fluoride (binder); 3% by mass Was added to a solution dissolved in 1-methyl-2-pyrrolidone and mixed to prepare a positive electrode mixture paste. This positive electrode mixture paste was applied to one side of an aluminum foil (current collector), dried, pressurized and cut into a predetermined size to produce a positive electrode sheet, and the end-of-charge voltage during battery evaluation 4.9 V (the positive electrode potential is 4.8 V on the Li basis in the fully charged state), the discharge end voltage is 2.7 V, and the composition of the non-aqueous electrolyte is changed to a predetermined one, A laminate type battery was produced in the same manner as in Example 1 and Comparative Example 1, and the battery was evaluated. The results are shown in Table 3.

Example 24, Comparative Example 6
In place of the negative electrode active material used in Example 1, a negative electrode sheet was prepared using lithium titanate Li ₄ Ti ₅ O ₁₂ (negative electrode active material). Lithium titanate Li ₄ Ti ₅ O ₁₂ ; 80% by mass, acetylene black (conductive agent); 15% by mass are mixed in advance, and polyvinylidene fluoride (binder); 5% by mass in 1-methyl-2-pyrrolidone A negative electrode mixture paste was prepared by adding to the dissolved solution and mixing. This negative electrode mixture paste was applied onto a copper foil (current collector), dried, pressurized and cut into a predetermined size to produce a negative electrode sheet, and the end-of-charge voltage during battery evaluation was 2 A laminated battery was produced in the same manner as in Example 1 except that the discharge end voltage was set to 0.8 V, the discharge end voltage was set to 1.2 V, and the composition of the nonaqueous electrolytic solution was changed to a predetermined value. The results are shown in Table 4.

In any of the lithium secondary batteries of Examples 1 to 21, the lithium secondary battery of Comparative Example 1 in the case where the compounds represented by the general formulas (I) to (VI) are not added to the nonaqueous electrolytic solution of the present invention. Battery, lithium secondary battery of Comparative Example 2 when sulfolane substituted only with an alkyl group is added, lithium secondary battery of Comparative Example 3 when 2-fluorosulfolane is added, and chain phosphonosulfonic acid compound Compared with the lithium secondary battery of Comparative Example 4 in the case of adding bismuth, the high-temperature storage characteristics at high voltage are improved. Further, from the comparison between Example 22 and Comparative Example 5, when LiNi _0.5 Mn _1.5 O ₄ is used for the positive electrode, from the comparison between Example 23 and Comparative Example 6, when lithium titanate is used for the negative electrode Has the same effect. Therefore, it is clear that the effect of the present invention is not dependent on the specific positive electrode and negative electrode.
As mentioned above, the effect at the time of using the electrical storage device of this invention at a high voltage is an effect peculiar when it contains the compound represented by general formula (I)-(VI) in nonaqueous electrolyte solution. It turned out to be.

  Furthermore, the non-aqueous electrolyte of the present invention also has an effect of improving high-temperature storage characteristics when a lithium primary battery is used at a high voltage.

  The electricity storage device using the non-aqueous electrolyte of the present invention is useful as an electricity storage device such as a lithium secondary battery having excellent electrochemical characteristics when the battery is used at a high voltage.

Claims (4)

A nonaqueous electrolytic solution for an electricity storage device, which contains at least one compound represented by the following general formula (I) in a nonaqueous electrolytic solution in which an electrolyte salt is dissolved in a nonaqueous solvent.
(Wherein R ^{1 to} R ⁶ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, or P (═O) (OR ⁷ ) _2. Group, OP (═O) (OR ⁸ ) ₂ group, OC (═O) R ⁹ group, or OS (═O) ₂ R ¹⁰ group, R ^7-10 is an alkyl group having 1 to 4 carbon atoms, A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms, L is a fluorine atom in which at least one hydrogen atom having 1 to 8 carbon atoms is An aliphatic divalent linking group or an oxygen atom which may be substituted with at least one of R ^{1 to} R ⁶ is P (═O) (OR ⁷ ) ₂ , OP (═O) ( OR ⁸ ) ₂ groups.) The nonaqueous electrolytic solution according to claim 1, wherein the compound of the general formula (I) is a compound represented by any one of the following general formulas (II) to (VI).
(Wherein R ^{11 to} R ¹⁷ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an OC (═O) R ¹⁹ group, OP ( ═O) (OEt) ₂ group, P (═O) (OEt) ₂ group, or OS (═O) ₂ R ²⁰ group, R ^{18 to} R ²⁰ are alkyl groups having 1 to 4 carbon atoms, carbon number A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms.)
(Wherein R ^{21 to} R ²⁷ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an OC (═O) R ²⁹ group, OP ( ═O) (OEt) ₂ group, P (═O) (OEt) ₂ group, or OS (═O) ₂ R ³⁰ group, R ^{28 to} R ³⁰ are alkyl groups having 1 to 4 carbon atoms, carbon number A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms.)
(In the formula, R ^{31 to} R ³⁵ each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, or a fluorinated alkyl group having 1 to 4 carbon atoms, and R ³⁶ represents 1 to 4 carbon atoms. Or an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms.)
(In the formula, R ^{41 to} R ⁴⁵ are each independently synonymous with R ^{31 to} R ³⁵ defined in general formula (IV), and R ⁴⁶ is synonymous with R ³⁶ defined in general formula (IV).)
Wherein R ^{51 to} R ⁵⁷ are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, or an OC (═O) R ⁵⁹ group. , OP (═O) (OEt) ₂ group, or OS (═O) ₂ R ⁶⁰ , wherein R ^{58 to} R ⁶⁰ groups are alkyl groups having 1 to 4 carbon atoms and fluorinated alkyl groups having 1 to 4 carbon atoms. Represents an aryl group having 6 to 12 carbon atoms or a halogenated aryl group having 6 to 12 carbon atoms.)   A power storage device comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte in which an electrolyte salt is dissolved in a non-aqueous solvent, wherein the non-aqueous electrolyte is the non-aqueous electrolyte according to claim 1 or 2. A power storage device characterized. Compounds represented by general formulas (VII) to (IX).
(In the formula, R ^{61 to} R ⁶⁷ are each independently synonymous with R ^{11 to} R ¹⁷ defined in general formula (II).)
(In the formula, R ^{71 to} R ⁷⁷ each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms, an OC (═O) R ²⁹ group, OP ( ═O) (OEt) ₂ group, P (═O) (OEt) ₂ group, or OS (═O) ₂ R ³⁰ group, R ^{28 to} R ³⁰ are alkyl groups having 1 to 4 carbon atoms, carbon number A fluorinated alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogenated aryl group having 6 to 12 carbon atoms, except that all of R ^{71 to} R ⁷⁷ are hydrogen atoms.
(In the formula, R ^{81 to} R ⁸⁷ are each independently synonymous with R ^{51 to} R ⁵⁷ defined in general formula (VI).)