JP2020064806A - Non-aqueous electrolyte solution and non-aqueous electrolyte battery - Google Patents

Abstract

To provide a non-aqueous electrolyte solution, having an excellent capacity retention rate, for suppressing increases in internal resistance and swelling due to charge and discharge and a non-aqueous electrolyte battery including the same.SOLUTION: Provided are a non-aqueous electrolyte solution containing a non-aqueous solvent and a compound represented by the following formula (1) and a non-aqueous electrolyte battery including the same. (In the formula (1), Rto Rare each a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, or an aryl group having 6 to 10 carbon atoms which may have a halogen atom.)SELECTED DRAWING: None

Description

The present invention relates to a non-aqueous electrolyte solution. More specifically, the present invention relates to a non-aqueous electrolyte solution that suppresses an increase in internal resistance and swelling due to charge and discharge and is excellent in capacity retention rate, and a non-aqueous electrolyte battery using the same.

Non-aqueous electrolyte secondary batteries such as lithium secondary batteries have been put to practical use in a wide range of applications such as power sources for mobile phones, laptop computers, on-vehicle power sources for automobiles, large stationary power sources, and the like. However, in recent years, the demand for higher performance of non-aqueous electrolyte secondary batteries has become higher and higher, and battery characteristics such as input / output characteristics, cycle characteristics, storage characteristics, continuous charging characteristics, and safety characteristics have been improved. Achieving a high standard is required.

Hitherto, it has been previously proposed to use an additive for a non-aqueous electrolyte solution in order to improve battery characteristics such as cycle characteristics of the non-aqueous electrolyte secondary battery. For example, Patent Document 1 discloses a technique capable of improving cycle characteristics and the like by including a disulfide derivative in a non-aqueous electrolyte solution. Further, Patent Document 2 discloses a technique capable of improving low-temperature discharge characteristics and the like by including a siloxane derivative in a non-aqueous electrolyte solution.

JP 2001-52735 A JP, 2006-93064, A

In Patent Documents 1 and 2 described above, the increase in internal resistance and swelling due to the additive has not been sufficiently investigated. The present invention has been made in view of the background art described above, and provides a non-aqueous electrolyte solution and a non-aqueous electrolyte secondary battery that have an excellent capacity retention rate and that suppress an increase in internal resistance and swelling due to charge and discharge. The purpose is to do.

The present inventor has conducted extensive studies to solve the above problems, and as a result, in a non-aqueous electrolyte solution used for a non-aqueous electrolyte secondary battery, the non-aqueous electrolyte solution is a compound having a partial structure of Si-S. It was found that the above problem can be solved by including the following. That is, the gist of the present invention is as follows.

（式（１）中、Ｒ^１〜Ｒ^４はそれぞれ水素原子、ハロゲン原子、ハロゲン原子を有してい
てもよい炭素数１〜４のアルキル基又はハロゲン原子を有していてもよい炭素数６〜１０
のアリール基を表す。） [1] A non-aqueous electrolyte containing a non-aqueous solvent and a compound represented by the following formula (1).

(In the formula (1), R ^{1 to} R ⁴ are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, or a carbon number 6 which may have a halogen atom. -10
Represents an aryl group. )

[2] The non-aqueous system according to [1], which contains at least one selected from the group consisting of tetramethyl orthothiosilicate, tetraethyl orthothiosilicate and tetraphenyl orthothiosilicate as the compound represented by the formula (1). Electrolyte.
[3] The non-aqueous electrolyte solution according to [1] or [2], wherein the content of the compound represented by the formula (1) is 0.001% by mass or more and 20% by mass or less.

[4] A non-aqueous electrolyte secondary battery comprising a negative electrode and a positive electrode capable of inserting and extracting metal ions, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution is any one of [1] to [3]. A non-aqueous electrolyte secondary battery which is the non-aqueous electrolyte according to the item.

According to the present invention, it is possible to provide a non-aqueous electrolyte solution capable of suppressing an increase in internal resistance due to charging / discharging while having an excellent capacity retention rate, and a non-aqueous electrolyte solution secondary battery using the same. .

Hereinafter, the present invention will be described in detail. The following description is an example (representative example) of the present invention, and the present invention is not limited thereto. Further, the present invention can be implemented by being modified arbitrarily within the scope of the invention.

[Non-aqueous electrolyte]
The non-aqueous electrolyte solution of the present invention contains a non-aqueous solvent and a compound represented by the following formula (1). In the following, the compound represented by the formula (1) may be referred to as “compound (1)”.

(In the formula (1), R ^{1 to} R ⁴ are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, or a carbon number 6 which may have a halogen atom. -10
Represents an aryl group. )

The non-aqueous electrolyte solution of the present invention has an effect of being able to suppress an increase in internal resistance and swelling due to charge and discharge, while having an excellent capacity retention rate. The reason why the present invention exerts such an effect is not clear, but it is presumed that the reason is as follows. That is, the compound represented by the formula (1) reacts under a constant potential to form a film derived from the compound (1) on the positive electrode,
It is presumed to suppress the oxidative decomposition of the electrolytic solution. Normally, in a non-aqueous electrolyte secondary battery, the electrolyte is oxidatively decomposed by repeated charging / discharging, but this side reaction is a cause of deterioration of the capacity retention rate, increase of internal resistance, swelling of the battery, etc. there were. It is presumed that the formation of a good coating film derived from the compound (1) on the positive electrode suppresses the oxidative decomposition of the electrolytic solution and suppresses the above-mentioned deterioration derived from the oxidative decomposition.

<1. Compound (1)>
The non-aqueous electrolyte solution of the present invention contains the compound represented by the formula (1). In the formula (1), R ^{1 to} R ⁴ are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, or a carbon number 6 which may have a halogen atom. And 10 aryl groups. Among these, preferred is an alkyl group having 1 to 4 carbon atoms which may have a halogen atom or an aryl group having 6 to 10 carbon atoms which may have a halogen atom, and a methyl group, an ethyl group, Particularly preferred is a propyl group, a butyl group, a phenyl group or a phenyl group in which a part of hydrogen is substituted with fluorine. More specifically, among the compounds represented by the above formula (1), it is preferable that at least one selected from the group consisting of tetramethyl orthothiosilicate, tetraethyl orthothiosilicate, and tetraphenyl orthothiosilicate is included.

The content of the compound represented by formula (1) in the non-aqueous electrolyte solution is not particularly limited as long as the effect of the present invention is not significantly impaired. Specifically, the lower limit of the content of this compound in the non-aqueous electrolyte solution is preferably 0.001 mass% or more, more preferably 0.05 mass% or more, and 0.1 More preferably, it is at least mass%. The upper limit is preferably 20% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less in the non-aqueous electrolyte solution. When the concentration of this compound is within the above-mentioned preferred range, the effect of suppressing internal resistance and swelling increase is more easily exhibited without impairing other battery performance.

<2. Non-aqueous solvent>
The non-aqueous electrolytic solution of the present invention usually contains, as a main component, a non-aqueous solvent that dissolves an electrolyte to be treated later, like a general non-aqueous electrolytic solution. The non-aqueous solvent used here is not particularly limited, and a known organic solvent can be used. As the organic solvent, preferably, saturated cyclic carbonate, chain carbonate, chain carboxylic acid ester, cyclic carboxylic acid ester,
At least one selected from ether compounds and sulfone compounds can be mentioned,
It is not particularly limited to these. These can be used alone or in combination of two or more.

<2-1. Saturated cyclic carbonate>
Examples of the saturated cyclic carbonate include those having an alkylene group having 2 to 4 carbon atoms. Specifically, examples of the saturated cyclic carbonate having 2 to 4 carbon atoms include ethylene carbonate, propylene carbonate, butylene carbonate and the like. Among them, ethylene carbonate and propylene carbonate are preferable from the viewpoint of improving the battery characteristics resulting from the improvement in the degree of lithium ion dissociation. As the saturated cyclic carbonate, one kind may be used alone, and two kinds or more may be used in optional combination and ratio.

The content of the saturated cyclic carbonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but the lower limit of the content when one type is used alone is usually 100% by volume of the non-aqueous solvent, It is 3% by volume or more, preferably 5% by volume or more. By setting this range, it is possible to avoid a decrease in electric conductivity due to a decrease in the dielectric constant of the non-aqueous electrolyte solution, and it is easy to set the large current discharge characteristics of the electricity storage device, the stability to the negative electrode, and the cycle characteristics in a good range. . The upper limit is usually 90% by volume or less, preferably 85% by volume or less, more preferably 80% by volume or less. By setting this range, the viscosity of the non-aqueous electrolyte solution is set to an appropriate range, the decrease in ionic conductivity is suppressed, and further the input / output characteristics of the electricity storage device are further improved, and the durability such as cycle characteristics and storage characteristics is improved. It is preferable because it can be further improved.

<2-2. Chain carbonate>
The chain carbonate preferably has 3 to 7 carbon atoms. Specifically, carbon number 3 to
As the chain carbonate of 7, dimethyl carbonate, diethyl carbonate, di-n
-Propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate, methyl-n-propyl carbonate, n-butyl methyl carbonate, isobutyl methyl carbonate, t-butyl methyl carbonate,
Examples thereof include ethyl-n-propyl carbonate, n-butyl ethyl carbonate, isobutyl ethyl carbonate and t-butyl ethyl carbonate. Among these, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate,
Methyl-n-propyl carbonate is preferable, and dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate are particularly preferable.

Further, chain carbonates having a fluorine atom (hereinafter, "fluorinated chain carbonate"
May be abbreviated. ) Can also be preferably used. The number of fluorine atoms contained in the fluorinated chain carbonate is not particularly limited as long as it is 1 or more, but is usually 6 or less, and preferably 4 or less. When the fluorinated chain carbonate has a plurality of fluorine atoms, they may be bonded to the same carbon or different carbons. Examples of the fluorinated chain carbonate include fluorinated dimethyl carbonate derivatives, fluorinated ethylmethyl carbonate derivatives, fluorinated diethyl carbonate derivatives and the like.

As the chain carbonate, one kind may be used alone, and two kinds or more may be used in optional combination and ratio.

Although the content of the chain carbonate is not particularly limited, it is usually 15% in 100% by volume of the non-aqueous solvent.
It is at least volume%, preferably at least 20 volume%, more preferably at least 25 volume%.
Further, it is usually 90% by volume or less, preferably 85% by volume or less, more preferably 80% by volume or less. By setting the content of the chain carbonate in the above range, the viscosity of the non-aqueous electrolytic solution is set in an appropriate range, the decrease in ionic conductivity is suppressed, and thus the input / output characteristics and charge / discharge rate characteristics of the electricity storage device are improved. It becomes easy to set the range. Further, it is possible to avoid a decrease in electric conductivity due to a decrease in dielectric constant of the non-aqueous electrolyte solution, and it is easy to set the input / output characteristics and the charge / discharge rate characteristics of the electricity storage device in a good range.

<2-3. Chain carboxylic acid ester>
Examples of the chain carboxylic acid ester include those having a total carbon number of 3 to 7 in the structural formula. Specifically, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, Isopropyl propionate, propionate-n
-Butyl, isobutyl propionate, -t-butyl propionate, methyl butyrate, ethyl butyrate, -n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, isobutyrate -n-propyl, isopropyl isobutyrate and the like. To be Among these, methyl acetate, ethyl acetate, acetic acid-n-propyl acetate-n-butyl acetate, methyl propionate, ethyl propionate, propionate-n-propyl, isopropyl propionate, methyl butyrate, ethyl butyrate, etc. It is preferable from the viewpoint of improving the ionic conductivity due to the decrease and suppressing the battery swelling during the durability test such as cycle and storage.

<2-4. Cyclic carboxylic acid ester>
Examples of the cyclic carboxylic acid ester include those having a total carbon atom number of 3 to 12 in the structural formula. Specific examples thereof include gamma butyrolactone, gamma valerolactone, gamma caprolactone, and epsilon caprolactone. Among these, gamma-butyrolactone is particularly preferable from the viewpoint of improving the battery characteristics resulting from the improvement in the degree of lithium ion dissociation.

<2-5. Ether compounds>
As the ether compound, a chain ether having 3 to 10 carbon atoms and a cyclic ether having 3 to 6 carbon atoms are preferable.

Examples of the chain ether having 3 to 10 carbon atoms include diethyl ether, di (2-fluoroethyl) ether, di (2,2-difluoroethyl) ether, di (2,2,2-trifluoroethyl) ether, ethyl. (2-Fluoroethyl) ether, ethyl (2,2,2-trifluoroethyl) ether, ethyl (1,1,2,2-tetrafluoroethyl) ether, (2-fluoroethyl) (2,2,2 -Trifluoroethyl) ether, (2-fluoroethyl) (1,1,2,2-tetrafluoroethyl) ether, (2,2,2-trifluoroethyl) (1,1,2,2-tetrafluoro Ethyl) ether, ethyl-n-propyl ether, ethyl (3-fluoro-n-propyl) ether, ethyl (3,3,3-
Trifluoro-n-propyl) ether, ethyl (2,2,3,3-tetrafluoro-n
-Propyl) ether, ethyl (2,2,3,3,3-pentafluoro-n-propyl)
Ether, 2-fluoroethyl-n-propyl ether, (2-fluoroethyl) (3-
Fluoro-n-propyl) ether, (2-fluoroethyl) (3,3,3-trifluoro-n-propyl) ether, (2-fluoroethyl) (2,2,3,3-tetrafluoro-n- Propyl) ether, (2-fluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, 2,2,2-trifluoroethyl-n-propyl ether, (2,2,2 2-trifluoroethyl) (3-fluoro-n-propyl) ether,
(2,2,2-trifluoroethyl) (3,3,3-trifluoro-n-propyl) ether, (2,2,2-trifluoroethyl) (2,2,3,3-tetrafluoro- n-propyl) ether, (2,2,2-trifluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, 1,1,2,2-tetrafluoroethyl-n -Propyl ether, (1,1,2,2-tetrafluoroethyl) (3-fluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethyl) (3,3,3-trifluoro -N-propyl) ether, (1,1,2,2-tetrafluoroethyl) (2,2,3
3-tetrafluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di-n-propyl ether , (N-propyl) (3-fluoro-n-propyl) ether, (n-propyl) (3,3,3-trifluoro-n-propyl) ether, (n-propyl) (2,2
, 3,3-Tetrafluoro-n-propyl) ether, (n-propyl) (2,2,3,
3,3-pentafluoro-n-propyl) ether, di (3-fluoro-n-propyl)
Ether, (3-fluoro-n-propyl) (3,3,3-trifluoro-n-propyl) ether, (3-fluoro-n-propyl) (2,2,3,3-tetrafluoro-n-
Propyl) ether, (3-fluoro-n-propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di (3,3,3-trifluoro-n-propyl) ether, (3,3,3-trifluoro-n-propyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (3,3,3-trifluoro-n-propyl) (2,2 , 3
, 3,3-Pentafluoro-n-propyl) ether, di (2,2,3,3-tetrafluoro-n-propyl) ether, (2,2,3,3-tetrafluoro-n-propyl) (
2,2,3,3,3-pentafluoro-n-propyl) ether, di (2,2,3,3,3)
3-pentafluoro-n-propyl) ether, di-n-butyl ether, dimethoxymethane, methoxyethoxymethane, methoxy (2-fluoroethoxy) methane, methoxy (
2,2,2-trifluoroethoxy) methane methoxy (1,1,2,2-tetrafluoroethoxy) methane, diethoxymethane, ethoxy (2-fluoroethoxy) methane, ethoxy (2,2,2-trifluoro (Ethoxy) methane, ethoxy (1,1,2,2-tetrafluoroethoxy) methane, di (2-fluoroethoxy) methane, (2-fluoroethoxy) (2,2,2-trifluoroethoxy) methane, (2 -Fluoroethoxy) (1,1
, 2,2-Tetrafluoroethoxy) methane di (2,2,2-trifluoroethoxy) methane, (2,2,2-trifluoroethoxy) (1,1,2,2-tetrafluoroethoxy) methane, di (1,1,2,2-tetrafluoroethoxy) methane, dimethoxyethane, methoxyethoxyethane, methoxy (2-fluoroethoxy) ethane, methoxy (2,
2,2-trifluoroethoxy) ethane, methoxy (1,1,2,2-tetrafluoroethoxy) ethane, diethoxyethane, ethoxy (2-fluoroethoxy) ethane, ethoxy (2,2,2-trifluoroethoxy) ) Ethane, ethoxy (1,1,2,2-tetrafluoroethoxy) ethane, di (2-fluoroethoxy) ethane, (2-fluoroethoxy) (2,2,2-trifluoroethoxy) ethane, (2- Fluoroethoxy) (1,1,
2,2-tetrafluoroethoxy) ethane, di (2,2,2-trifluoroethoxy) ethane, (2,2,2-trifluoroethoxy) (1,1,2,2-tetrafluoroethoxy) ethane, Di (1,1,2,2-tetrafluoroethoxy) ethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether and the like can be mentioned.

As the cyclic ether, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-
Methyl-1,3-dioxane, 1,4-dioxane, and the like, and fluorinated compounds thereof may be mentioned. Among these, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether have high solvating ability to lithium ions and dissociate lithium ions. Is preferable in terms of improving Particularly preferred are dimethoxymethane, diethoxymethane and ethoxymethoxymethane because they have low viscosity and high ionic conductivity.

<2-6. Sulfone compounds>
As the sulfone compound, a cyclic sulfone having 3 to 6 carbon atoms and a chain sulfone having 2 to 6 carbon atoms are preferable. The number of sulfonyl groups in one molecule is preferably 1 or 2.

Examples of the cyclic sulfone include trimethylene sulfones which are monosulfone compounds, tetramethylene sulfones and hexamethylene sulfones; trimethylene disulfones which are disulfone compounds, tetramethylene disulfones and hexamethylene disulfones. Among these, from the viewpoint of dielectric constant and viscosity, tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones, and hexamethylene disulfones are more preferable, and tetramethylene sulfones (sulfolanes) are particularly preferable.

As the sulfolane, a sulfolane and / or a sulfolane derivative (hereinafter, abbreviated as “sulfolane” including sulfolane) may be preferable. The sulfolane derivative is preferably a sulfolane derivative in which one or more hydrogen atoms bonded to carbon atoms constituting the sulfolane ring are substituted with a fluorine atom or an alkyl group.

Among these, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,2-difluorosulfolane, 2,3-difluorosulfolane, 2,4-difluorosulfolane, 2,5-difluoro Sulfolane, 3,4-difluorosulfolane, 2-fluoro-3-methylsulfolane, 2-fluoro-2-methylsulfolane, 3-fluoro-3-methylsulfolane, 3-fluoro-2-methylsulfolane, 4-fluoro-3 -Methylsulfolane, 4-fluoro-2-methylsulfolane, 5-
Fluoro-3-methylsulfolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane, 3-fluoromethylsulfolane, 2-difluoromethylsulfolane,
3-difluoromethylsulfolane, 2-trifluoromethylsulfolane, 3-trifluoromethylsulfolane, 2-fluoro-3- (trifluoromethyl) sulfolane, 3-fluoro-3- (trifluoromethyl) sulfolane, 4-fluoro- 3- (trifluoromethyl) sulfolane, 5-fluoro-3- (trifluoromethyl) sulfolane and the like are preferable because of high ionic conductivity and high input / output.

As the chain sulfone, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, n-propyl ethyl sulfone, di-n-propyl sulfone, isopropyl methyl sulfone, isopropyl ethyl sulfone, diisopropyl sulfone, n- Butyl methyl sulfone, n-butyl ethyl sulfone, t-butyl methyl sulfone, t-butyl ethyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, Trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trif Oromethyl sulfone, perfluoroethyl methyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di (trifluoroethyl) sulfone, perfluorodiethyl sulfone, fluoromethyl-n-propyl sulfone, difluoromethyl-n-propyl sulfone , Trifluoromethyl-n-
Propyl sulfone, fluoromethyl isopropyl sulfone, difluoromethyl isopropyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl-n-propyl sulfone, trifluoroethyl isopropyl sulfone, pentafluoroethyl-n-
Propyl sulfone, pentafluoroethyl isopropyl sulfone, trifluoroethyl-
Examples thereof include n-butyl sulfone, trifluoroethyl-t-butyl sulfone, pentafluoroethyl-n-butyl sulfone and pentafluoroethyl-t-butyl sulfone.

Among these, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-
Propyl methyl sulfone, isopropyl methyl sulfone, n-butyl methyl sulfone, t
-Butyl methyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone , Ethyldifluoromethylsulfone, ethyltrifluoromethylsulfone, ethyltrifluoroethylsulfone, ethylpentafluoroethylsulfone, trifluoromethyl-n-propylsulfone, trifluoromethylisopropylsulfone, trifluoroethyl-n-butylsulfone, trifluoro Ethyl-t-butyl sulfone, trifluoromethyl-n-butyl sulfone, trifluoromethyl-t-butyl sulfone Emissions, and the like are preferable from the viewpoint high high output ionic conductivity.

<3. Electrolyte>
The non-aqueous electrolytic solution of the present invention usually contains an electrolyte. In particular, when the non-aqueous electrolyte of the present invention is a lithium ion secondary battery, it usually contains a lithium salt.

Examples of the lithium salt that can be used in the non-aqueous electrolyte solution of the present invention include LiClO 2.
_{4, LiBF 4, LiPF 6,} LiAsF 6, LiTaF 6, LiCF 3 SO 3, LiC
₄ F ₉ SO ₃ , Li (FSO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO
₂ ) ₂ N, Li (CF ₃ ) SO ₂ ) ₃ C, LiBF ₃ (C ₂ F ₅ ), LiB (C ₂ O ₄ ).
₂ , LiB (C ₆ F ₅ ) ₄ , LiPF ₃ (C ₂ F ₅ ) _{3 and the} like. Of these,
Preferred are LiPF ₆ , LiBF ₄ , LiClO ₄ , Li (FSO ₂ ) ₂ N and L.
At least one selected from i (CF ₃ SO ₂ ) ₂ N, more preferably LiP
At least one selected from F ₆ , LiBF ₄ , Li (FSO ₂ ) ₂ N and Li (CF ₃ SO ₂ ) ₂ N, and more preferably LiPF ₆ and Li (CF ₃ SO ₂ ) ₂ N At least one of them, and LiPF ₆ is particularly preferable. The lithium salts listed above may be used alone or in combination of two or more.

The concentration of the electrolyte such as a lithium salt in the final composition of the non-aqueous electrolyte solution of the present invention is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 0.5 mol / L or more, more preferably Is 0.6 mol / L or more, more preferably 0.7 mol / L or more, while preferably 3 mol / L or less, more preferably 2 mol / L or less, further preferably 1.8 mol / L. It is L or less. When the content of the lithium salt is within the above range, the ionic conductivity can be appropriately increased.

The method for measuring the content of the above-mentioned lithium salt is not particularly limited, and any known method can be used. Examples of such a method include ion chromatography and F magnetic resonance spectroscopy.

<4. Other additives>
The non-aqueous electrolyte solution of the present invention, in addition to the various compounds listed above, malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile, cyano groups such as dodecanedinitrile. With 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (
Isocyanatomethyl) cyclohexane, 1,3-phenylene diisocyanate, 1,4-
Phenylene diisocyanate, 1,2-bis (isocyanatomethyl) benzene, 1,3-
Isocyanato compounds such as bis (isocyanatomethyl) benzene and 1,4-bis (isocyanatomethyl) benzene, acrylic anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride, benzoic anhydride, 2-methylbenzoic anhydride, 4-methylbenzoic anhydride, 4-tert-butylbenzoic anhydride, 4-fluorobenzoic anhydride, 2, 3, 4,
Carboxylic anhydride compounds such as 5,6-pentafluorobenzoic anhydride, methoxyformic anhydride, ethoxyformic anhydride, succinic anhydride, and maleic anhydride; cyclic rings having unsaturated bonds such as vinylene carbonate and vinylethylene carbonate Sulfonic acid ester compounds such as carbonates and 1,3-propane sultone, phosphates such as lithium difluorophosphate and sulfonates such as lithium fluorosulfonate may be added. However, the lithium difluorophosphate and lithium fluorosulfonate listed here correspond to lithium salts, but are not treated as an electrolyte from the viewpoint of the degree of ionization with respect to the non-aqueous solvent used in the non-aqueous electrolytic solution, and the additive is used. Shall be positioned. In addition, various additives such as cyclohexylbenzene, t-butylbenzene, t-amylbenzene, biphenyl, alkylbiphenyl, terphenyl, partially hydrogenated terphenyl, diphenyl ether, dibenzofuran, etc. are added as an overcharge inhibitor to the effect of the present invention. Can be blended within a range not significantly impairing These compounds may be used in appropriate combination. Among these, from the viewpoint of capacity retention rate,
Vinylene carbonate, lithium difluorophosphate and lithium fluorosulfonate are particularly preferable, and it is particularly preferable to use them in combination.

[Non-aqueous electrolyte battery]
A non-aqueous electrolyte solution battery (hereinafter, may be referred to as "non-aqueous electrolyte solution battery of the present invention") can be obtained by using the non-aqueous electrolyte solution, positive electrode and negative electrode of the present invention. Examples of the non-aqueous electrolyte battery include a lithium ion secondary battery and a sodium ion secondary battery, but a lithium ion secondary battery is preferable. A lithium ion secondary battery usually has a non-aqueous electrolyte solution of the present invention, a current collector and a positive electrode active material layer provided on the current collector, and a positive electrode capable of inserting and extracting lithium ions, and a positive electrode. A negative electrode having an electric current collector and a negative electrode active material layer provided on the current collector and capable of inserting and extracting lithium ions.

<1. Positive electrode>
Examples of the positive electrode material that is the active material of the positive electrode of the non-aqueous secondary battery of the present invention include, for example, a lithium cobalt composite oxide whose basic composition is represented by LiCoO ₂ , a lithium nickel composite oxide represented by LiNiO ₂ , and LiMnO 2. ₂ and LiMn ₂ O ₄ , lithium transition metal composite oxides such as lithium manganese composite oxides, transition metal oxides such as manganese dioxide, and composite oxide mixtures thereof may be used. Furthermore, TiS ₂ , FeS ₂ , Nb ₃ S ₄ , M
_{o 3 S 4, CoS 2,} V 2 O 5, CrO 3, V 3 O 3, FeO 2, GeO 2 and Li (N
i _1/3 Mn _1/3 Co _1/3 ) O ₂ , LiFePO ₄ or the like may be used. From the viewpoint of capacity density, Li (Ni _0.5 Mn _0.3 Co _0.2 ) O _{2 and} Li ( Ni _0.5 Mn _0.2 C
o _0.3 ) O _2, Li (Ni _0.6 Mn _0.2 Co _0.2 ) O _2, Li (Ni _0.8 Mn
_0.1 Co _0.1 ) O _2, Li (Ni _0.8 Co _0.15 Al _0.05 ) O _{2 and the} like are particularly preferable.

<2. Negative electrode>
The negative electrode usually has a negative electrode active material layer on the current collector, and the negative electrode active material layer contains the negative electrode active material. Hereinafter, the negative electrode active material will be described.

As the negative electrode active material, as long as it can electrochemically store and release s-block metal ions such as lithium ions, lithium ions, potassium ions, and magnesium ions,
There is no particular limitation. Specific examples thereof include carbonaceous materials, metal compound-based materials and their oxides, carbides, nitrides, silicides, sulfides, phosphides, and the like. These may be used alone or in any combination of two or more.

The carbonaceous material used as the negative electrode active material is not particularly limited, but examples thereof include graphite, amorphous carbon, and a carbonaceous material having a low degree of graphitization. Examples of graphite include natural graphite and artificial graphite. Alternatively, a carbonaceous material such as an amorphous carbon or a graphitized material may be used. Examples of the amorphous carbon include particles obtained by firing bulk mesophase and particles obtained by subjecting a carbon precursor to infusibilization treatment and firing. Examples of the carbonaceous material particles having a low degree of graphitization include those obtained by firing an organic material at a temperature of usually less than 2500 ° C. These may be used alone or in any combination of two or more.

The metal compound material used as the negative electrode active material is not particularly limited, but for example, Ag, Al, Bi, Cu, Ga, Ge, In, Ni, P, Pb, Sb, Si, Sn, S.
Examples thereof include compounds containing a metal such as r and Zn. Among these, simple substances of silicon and / or tin, alloys, oxides and carbides, nitrides and the like are preferable, and particularly, simple substance of Si and SiOx (
0.5 ≦ O ≦ 1.6) is preferable from the viewpoint of capacity per unit mass and environmental load.

<3. Separator>
A separator is usually interposed between the positive electrode and the negative electrode to prevent a short circuit. In this case, the non-aqueous electrolytic solution of the present invention is usually used by impregnating this separator.

There is no particular limitation on the material and shape of the separator, and any known material can be used as long as the effects of the present invention are not significantly impaired. Among these, formed of a material stable to the non-aqueous electrolyte of the present invention, a resin, glass fiber, an inorganic material or the like is used, such as a porous sheet or a non-woven fabric-like material excellent in liquid retention. It is preferably used.

As the material of the resin and the glass fiber separator, for example, polyolefin such as polyethylene and polypropylene, polytetrafluoroethylene, polyether sulfone, and glass filter can be used. Among these, glass filters and polyolefins are preferable, and polyolefins are more preferable. These materials may be used alone or in any combination of two or more in any ratio.

The thickness of the separator is arbitrary, but is usually 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and usually 50 μm or less, 40 μm or less, preferably 30 μm or less. If the separator is too thin than the above range, the insulating property and mechanical strength may decrease. If the thickness is more than the above range, not only the battery performance such as rate characteristics may deteriorate, but also the energy density of the entire power storage device may decrease.

Furthermore, when using a porous material such as a porous sheet or a non-woven fabric as the separator, the porosity of the separator is arbitrary, but is usually 20% or more, preferably 35% or more, and 45%.
The above is more preferable, and usually 90% or less, preferably 85% or less, more preferably 75% or less. If the porosity is smaller than the above range, the film resistance tends to increase and the rate characteristics tend to deteriorate. On the other hand, if it is larger than the above range, the mechanical strength of the separator is lowered and the insulating property tends to be lowered.

The average pore size of the separator is also arbitrary, but is usually 0.5 μm or less and 0.2 μm.
The following is preferable, and it is usually 0.05 μm or more. When the average pore size exceeds the above range, short circuit is likely to occur. On the other hand, if it is less than the above range, the film resistance may increase and the rate characteristics may deteriorate.

On the other hand, as the inorganic material, for example, oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate are used. Things are used.

As the form, a non-woven fabric, a woven fabric, a thin film-shaped one such as a microporous film is used. In the form of a thin film, one having a pore diameter of 0.01 to 1 μm and a thickness of 5 to 50 μm is preferably used.
In addition to the above-mentioned independent thin film shape, a separator can be used in which a composite porous layer containing the inorganic particles is formed on the surface layer of the positive electrode and / or the negative electrode using a resin binder. For example, the porous layer may be formed on both surfaces of the positive electrode by using alumina particles having a 90% particle diameter of less than 1 μm and a fluororesin as a binder.

<4. Conductive material>
The positive electrode and the negative electrode described above may include a conductive material in order to improve conductivity. Any known conductive material can be used as the conductive material. Specific examples thereof include metal materials such as copper and nickel; graphite such as natural graphite and artificial graphite; carbon black such as acetylene black; and carbonaceous materials such as amorphous carbon such as needle coke. In addition, these may be used individually by 1 type and may be used together by 2 or more types in arbitrary combinations and ratios.

The conductive material is usually 0.01 parts by mass or more, preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and usually 50 parts by mass or less with respect to 100 parts by mass of the positive electrode material or the negative electrode material.
It is preferably used in an amount of 30 parts by mass or less, more preferably 15 parts by mass or less.
When the content is less than the above range, the conductivity may be insufficient. If it exceeds the above range, the battery capacity may decrease.

<5. Binder>
The positive electrode and the negative electrode described above may contain a binder in order to improve the binding property. The binder is
The material is not particularly limited as long as it is a material that is stable with respect to the non-aqueous electrolyte solution and the solvent used for manufacturing the electrode.

In the case of the coating method, any material that can be dissolved or dispersed in the liquid medium used for manufacturing the electrode may be used, and specific examples include polyethylene, polypropylene, polyethylene terephthalate, polymethylmethacrylate, aromatic polyamide, cellulose, nitro. Resin-based polymers such as cellulose; rubber-like polymers such as SBR (styrene / butadiene rubber), NBR (acrylonitrile / butadiene rubber), fluororubber, isoprene rubber, butadiene rubber, ethylene / propylene rubber; styrene / butadiene / styrene blocks Copolymer or hydrogenated product thereof, EPDM (ethylene / propylene / diene terpolymer), styrene / ethylene /
Thermoplastic elastomer polymer such as butadiene / ethylene copolymer, styrene / isoprene / styrene block copolymer or hydrogenated product thereof; syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene / vinyl acetate copolymer Polymers, soft resinous polymers such as propylene / α-olefin copolymers; high fluorine-based polymers such as polyvinylidene fluoride (PVdF), polytetrafluoroethylene, fluorinated polyvinylidene fluoride, and polytetrafluoroethylene / ethylene copolymers Molecules: polymer compositions having ion conductivity of alkali metal ions (particularly lithium ions) and the like can be mentioned. These substances may be used alone or in any combination of two or more at any ratio.

The proportion of the binder is usually 0.1 parts by mass or more, preferably 1 part by mass or more, more preferably 3 parts by mass or more, and usually 50 parts by mass with respect to 100 parts by mass of the positive electrode material or the negative electrode material. It is below, preferably 30 parts by mass or less, more preferably 10 parts by mass or less, and further preferably 8 parts by mass or less. When the proportion of the binder is within the above range, the binding property of the electrode can be sufficiently maintained, the mechanical strength of the electrode can be maintained, and it is preferable in terms of cycle characteristics, battery capacity and conductivity.

<6. Liquid medium>
As the liquid medium for forming the slurry, if it is a solvent capable of dissolving or dispersing the active material, the conductive material, the binder, and the thickener used as necessary, it is particularly suitable for the type. There is no limitation, and either an aqueous solvent or an organic solvent may be used.

Examples of the aqueous medium include water, a mixed medium of alcohol and water, and the like. Examples of organic media include aliphatic hydrocarbons such as hexane; benzene, toluene, xylene,
Aromatic hydrocarbons such as methylnaphthalene; Heterocyclic compounds such as quinoline and pyridine; Ketones such as acetone, methyl ethyl ketone and cyclohexanone; Esters such as methyl acetate and methyl acrylate; Diethylenetriamine, N, N-dimethylaminopropylamine And the like; ethers such as diethyl ether and tetrahydrofuran (THF); amides such as N-methylpyrrolidone (NMP), dimethylformamide, and dimethylacetamide;
Aprotic polar solvents such as hexamethylphosphamide, dimethylsulfoxide and the like can be mentioned. In addition, these may be used individually by 1 type, and may be used in combination of 2 or more types by arbitrary combinations and ratios.

<7. Thickener>
When an aqueous medium is used as the liquid medium for forming the slurry, it is preferable to use a thickener and a latex such as styrene-butadiene rubber (SBR) to make a slurry. Thickeners are commonly used to adjust the viscosity of slurries.

The thickener is not limited unless the effect of the present invention is significantly limited, but specifically, carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and salts thereof. Etc. These may be used alone or in any combination of two or more at any ratio.

When a thickener is further used, it is usually 0.1 part by mass or more, preferably 0.5 part by mass or more, more preferably 0.6 part by mass or more, relative to 100 parts by mass of the positive electrode material or the negative electrode material. Further, it is usually 5 parts by mass or less, preferably 3 parts by mass or less, more preferably 2 parts by mass or less. If it is less than the above range, the coating property may be significantly reduced, and if it exceeds the above range,
The proportion of the active material in the active material layer may decrease, which may cause a problem of decreasing the capacity of the battery and increase the resistance between the active materials.

<8. Current collector>
The material of the current collector is not particularly limited, and any known material can be used. Specific examples include metal materials such as aluminum, stainless steel, nickel plating, titanium, tantalum, and copper; carbonaceous materials such as carbon cloth and carbon paper. Among these, metal materials, particularly aluminum are preferable.

Examples of the shape of the current collector include a metal foil, a metal cylinder, a metal coil, a metal plate, a metal thin film, an expanded metal, a punch metal, and a foam metal in the case of a metal material, and a carbon plate in the case of a carbonaceous material, Examples thereof include carbon thin films and carbon cylinders. Of these, metal thin films are preferred.
The thin film may be appropriately formed in a mesh shape.

Although the thickness of the current collector is arbitrary, it is usually 1 μm or more, preferably 3 μm or more, and 5 μm.
The above is more preferable, and it is usually 1 mm or less, preferably 100 μm or less, and 50 μm.
It is more preferably m or less. When the thin film is within the above range, the strength required as a current collector is maintained,
It is also preferable from the viewpoint of handleability.

<9. Battery design>
[Electrode group]
The electrode group has a laminated structure including the positive electrode plate and the negative electrode plate with the separator interposed therebetween,
Also, any of the above-described positive electrode plate and negative electrode plate may be spirally wound with the separator interposed therebetween. The ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as the electrode group occupancy rate) is usually 40% or more, preferably 50% or more, and usually 90% or less, 80% or less. preferable. When the electrode group occupancy rate is below the above range, the battery capacity becomes small. In addition, if it exceeds the above range, the void space is small, the internal pressure rises because the member expands or the vapor pressure of the liquid component of the electrolyte increases due to the high temperature of the battery, and the repeated charge and discharge performance as a battery In some cases, various characteristics such as high temperature storage may be deteriorated, and further, a gas release valve that releases internal pressure to the outside may operate.

[Current collecting structure]
The current collecting structure is not particularly limited, but in order to more effectively realize the improvement of the discharge characteristics by the non-aqueous electrolyte solution of the present invention, a structure in which the resistance of the wiring portion or the joint portion is reduced is required. preferable. When the internal resistance is reduced in this way, the effect of using the non-aqueous electrolyte solution of the present invention is particularly well exhibited.

When the electrode group has the above-mentioned laminated structure, a structure formed by bundling the metal core portions of the electrode layers and welding the terminals is preferably used. Since the internal resistance increases when the area of one electrode increases, it is also preferable to provide a plurality of terminals in the electrode to reduce the resistance. In the case where the electrode group has the above-described wound structure, the internal resistance can be lowered by providing a plurality of lead structures for the positive electrode and the negative electrode and bundling them in the terminal.

[Exterior case]
The material of the outer case is not particularly limited as long as it is a stable substance with respect to the non-aqueous electrolyte solution used. Specifically, nickel-plated steel plates, metals such as stainless steel, aluminum or aluminum alloys, and magnesium alloys, or laminated films of resin and aluminum foil (
A laminated film) is used. From the viewpoint of weight reduction, a metal of aluminum or aluminum alloy, or a laminated film is preferably used.

In the outer case using the metals, laser welding, resistance welding, ultrasonic welding to weld the metals to each other to form a hermetically sealed structure, or a caulking structure using the metals via a resin gasket. There are things to do. Examples of the outer case using the laminate film include those having a sealed structure by heat-sealing resin layers.
In order to improve the sealing property, a resin different from the resin used for the laminate film may be interposed between the resin layers. In particular, when a resin layer is heat-sealed via a collector terminal to form a hermetically sealed structure, a metal and a resin are bonded, so a resin having a polar group or a modification having a polar group introduced as an intervening resin. Resin is preferably used.

[Protective element]
As the above-mentioned protection element, the PTC (Po which increases the resistance when abnormal heat generation or excessive current flows)
Examples include a positive temperature coefficient, a temperature fuse, a thermistor, and a valve (current cutoff valve) that cuts off a current flowing in a circuit due to a sudden increase in internal pressure or internal temperature of a battery during abnormal heat generation. It is preferable to select the protection element under the condition that it does not operate at high current in normal use, and from the viewpoint of high output, it is more preferable to design it so as not to cause abnormal heat generation or thermal runaway without the protection element.

[Exterior body]
The electricity storage device of the present invention is usually constituted by accommodating the above-mentioned non-aqueous electrolyte solution, negative electrode, positive electrode, separator and the like in an outer casing. There is no limitation on the outer package, and any known package can be used as long as the effect of the present invention is not significantly impaired.

Specifically, the material of the outer package is arbitrary, but, typically, nickel-plated iron, stainless steel, aluminum or an alloy thereof, nickel, titanium, or the like is used.

The shape of the outer package is also arbitrary, and may be, for example, a cylindrical type, a rectangular type, a laminated type, a coin type, a large size, or the like.

Hereinafter, the present invention will be described in more detail with reference to Examples and Reference Examples, but the present invention is not limited to these Examples as long as the gist thereof is not exceeded.

(Example 1)
[Preparation of negative electrode]
An aqueous dispersion was added to 98 parts by mass of the carbonaceous material as a thickening agent and a binder so that sodium carboxymethyl cellulose was 1 part by mass, and further an aqueous dispersion was added so that the styrene-butadiene rubber was 1 part by mass. , And mixed with a disperser to make a slurry. The obtained slurry was applied to a copper foil having a thickness of 10 μm, dried, and rolled with a press to obtain an active material layer having a width of 32 mm, a length of 42 mm, and a width of 5 mm.
A negative electrode was obtained by cutting into a shape having an uncoated portion with a length of 9 mm.

[Production of positive electrode]
85 parts by mass of Li (Ni _1/3 Mn _1/3 Co _1/3 ) O ₂ as a positive electrode active material, 10 parts by mass of carbon black as a conductive material, and polyvinylidene fluoride (PVd) as a binder.
F) 5 parts by mass were mixed in an N-methylpyrrolidone solvent to form a slurry. The obtained slurry was applied to one side of an aluminum foil having a thickness of 15 μm, dried, and roll-pressed with a pressing machine to obtain an active material layer having a width of 30 mm, a length of 40 mm, and a width of 5 mm. It was cut into a shape having an uncoated portion with a thickness of 9 mm to obtain a positive electrode.

[Preparation of electrolyte]
In a dry argon atmosphere, ethylene carbonate (EC) and dimethyl carbonate (DM
C) and ethyl methyl carbonate (EMC) (volume ratio 30:30:40) was dissolved in dry LiPF ₆ at a ratio of 1 mol / L to prepare an electrolytic solution, which was used as a basic electrolytic solution. . Tetraethyl orthothiosilicate was mixed with this basic electrolyte solution to a concentration of 0.5% by mass, and the saturated solution was used as the electrolyte solution of Example 1.

[Manufacture of lithium secondary battery]
The positive electrode, the negative electrode, and the polypropylene separator were laminated in this order on the negative electrode, the separator, and the positive electrode to prepare a battery element. This battery element was inserted into a bag made of a laminate film in which both sides of aluminum (thickness 40 μm) were coated with a resin layer while projecting the terminals of the positive electrode and the negative electrode, and then the above-mentioned electrolytic solution was injected into the bag and vacuumed. The sheet-like battery of Example 1 which was sealed and was in a fully charged state at 4.2 V was produced.

[Evaluation of cycle characteristics]
For a new battery that has not undergone a charge / discharge cycle, a voltage range of 4.2 V to 2.5 at 25 ° C.
V, current value 1 / 6C (current value to discharge rated capacity in 1 hour by discharge capacity of 1 hour rate is 1
Let be C. The same applies below. ), And then charged to 4.1V, and then at 60 ℃ 12
The battery was stabilized by performing heat treatment for an hour. Then, at 25 ° C, the voltage range is 4.2V to 2.5V.
It was charged and discharged once at V and a current value of 1 / 6C, and this discharge capacity was used as the initial discharge capacity. afterwards,
Charge and discharge at a voltage range of 4.2 V to 2.5 V and a current value of 1 C at 60 ° C. were repeated 100 times. Then, the battery was charged and discharged once at 25 ° C. in a voltage range of 4.2 V to 2.5 V and a current value of 1/6 C, and this discharge capacity was taken as the discharge capacity after 100 cycles. [(Discharge capacity after 100 cycles) / (
The cycle capacity retention rate (%) was calculated from the initial discharge capacity)] × 100. The results are shown in Table 1.

[Evaluation of -30 ° C resistance characteristic after cycle]
Before and after the 100-cycle charge / discharge test, the battery was charged at 25 ° C. with a constant current of 1/6 C so that the capacity became half of the initial discharge capacity. 0.25 each at -30 ° C
The discharge was carried out at C, 0.5C, 0.75C, 1.0C, 1.5C and 2C, and the voltage at 2 seconds was measured. The resistance value (Ω) was obtained from the slope of the current-voltage line, and the internal resistance increase ratio was obtained from [(resistance value after 100 cycle test) / (resistance value before 100 cycle test)]. The results are shown in Table 1.

[Evaluation of volume change after cycle]
Before and after the 100-cycle charge / discharge test, the mass of the battery was observed in a state of being immersed in ethanol, the buoyancy was obtained from the difference from the actual amount, and the volume of the battery was measured by dividing by the density of ethanol. The volume increase ratio was determined from [(volume after 100 cycle test) / (volume before 100 cycle test)]. The results are shown in Table 1.

(Comparative Example 1)
An electrolyte solution was prepared in the same manner as in Example 1 except that tetraethylorthothiosilicate was not used, and a sheet-shaped lithium secondary battery was produced and evaluated. The results are shown in Table 1.

As is clear from Table 1 above, the lithium secondary battery using the non-aqueous electrolyte solution containing the compound (1) of the present invention has a high capacity retention rate, a low resistance value increase ratio, and a volume increase ratio. Is low. Although the cycle test period in each of the examples and comparative examples shown in Table 1 above is modeled as a relatively short period, significant differences have been confirmed. Since the actual use of the non-aqueous electrolyte secondary battery may last for several years, it can be understood that the difference between these results becomes more remarkable when the long-term use is assumed.

INDUSTRIAL APPLICABILITY The non-aqueous electrolyte solution of the present invention can suppress an increase in internal resistance and swelling due to charge and discharge, and can provide a non-aqueous secondary battery having an excellent capacity retention rate. Therefore, the non-aqueous electrolyte solution of the present invention and the non-aqueous secondary battery obtained by using the same can be used for various known applications. Specific examples include, for example, laptop computers, pen input computers, mobile computers, e-book players, mobile phones, mobile fax machines, mobile copy machines, mobile printers, headphone stereos, video movies, LCD TVs, handy cleaners, portable CDs, mini disks. , Walkie-talkie, electronic organizer, calculator, memory card, portable tape recorder, radio, backup power supply, motor, automobile, motorcycle, motorbike, bicycle, lighting equipment, toys, game equipment, clock, power tool, strobe, camera, home Backup power supply, office backup power supply, load leveling power supply, natural energy storage power supply, lithium ion capacitor, etc.

Claims (4)

A non-aqueous electrolyte containing a non-aqueous solvent and a compound represented by the following formula (1).

(In the formula (1), R ^{1 to} R ⁴ are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, or a carbon number 6 which may have a halogen atom. -10
Represents an aryl group. ) The non-aqueous electrolyte solution according to claim 1, wherein the compound represented by the formula (1) contains at least one selected from the group consisting of tetramethyl orthothiosilicate, tetraethyl orthothiosilicate, and tetraphenyl orthothiosilicate. The non-aqueous electrolyte solution according to claim 1, wherein the content of the compound represented by the formula (1) is 0.001% by mass or more and 20% by mass or less. A non-aqueous electrolyte secondary battery comprising a negative electrode and a positive electrode capable of occluding and releasing metal ions, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution is the non-aqueous electrolyte solution according to any one of claims 1 to 3. A non-aqueous electrolyte secondary battery that is an aqueous electrolyte.