JP2014002976A - Nonaqueous electrolyte and nonaqueous electrolyte battery including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a nonaqueous electrolyte suppressing deterioration in capacity and gas generation, when a nonaqueous electrolyte secondary battery is stored at high temperature; and a nonaqueous electrolyte battery including the nonaqueous electrolyte.SOLUTION: In a nonaqueous electrolyte including an electrolyte and a nonaqueous solvent, the nonaqueous electrolyte contains a compound represented by general formula (1).

Description

  The present invention relates to a non-aqueous electrolyte and a non-aqueous electrolyte battery using the same.

  Non-aqueous electrolyte batteries such as lithium secondary batteries are being put to practical use in a wide range of applications, from the power sources of so-called portable electronic devices such as mobile phones and notebook computers to in-vehicle power sources for automobiles.

The electrolyte used for a non-aqueous electrolyte battery is usually composed mainly of an electrolyte and a non-aqueous solvent. The main components of the non-aqueous solvent include cyclic carbonates such as ethylene carbonate and propylene carbonate; chain carbonates such as dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate; cyclic carboxylic acid esters such as γ-butyrolactone and γ-valerolactone. It is used.
In order to improve battery characteristics such as load characteristics, cycle characteristics, and storage characteristics of such non-aqueous electrolyte batteries, various studies have been made on non-aqueous solvents and electrolytes.
In Patent Document 1, in a lithium battery including an electrolytic solution containing a halogen-containing compound as a single solvent or one component of a mixed solvent, a nitrogen-containing compound such as N-alkylformamide is added to the electrolytic solution. It has been disclosed to improve the storage characteristics of lithium batteries.

JP-A-10-189008

However, the demand for higher performance of batteries in recent years is increasing, and it is required to achieve various battery characteristics such as high capacity, high temperature storage characteristics, and cycle characteristics at a high level.
As a method for increasing the capacity, for example, a method of increasing the density by pressurizing the active material layer of the electrode and reducing the volume occupied by the active material other than the active material inside the battery as much as possible, or expanding the usage range of the positive electrode to a high potential The method to use is being studied. However, if the active material layer of the electrode is pressurized and densified, it becomes difficult to use the active material uniformly, and deterioration of the active material is promoted by non-uniform reaction, so that sufficient characteristics cannot be obtained. Problems are likely to occur. Further, when the use range of the positive electrode is expanded to be used up to a high potential, the activity of the positive electrode is further increased, and the problem that the deterioration is accelerated by the reaction between the positive electrode and the electrolytic solution is likely to occur. In particular, when stored under high temperature conditions in a charged state, it is known that the battery capacity decreases due to a side reaction between the electrode and the electrolyte solution. In order to improve storage characteristics, various nonaqueous solvents and electrolytes are used. Consideration has been made.
Further, the increase in capacity reduces the gap in the battery, and there is a problem that the internal pressure of the battery increases remarkably even when a small amount of gas is generated by the decomposition of the electrolyte.
The non-aqueous electrolyte secondary battery using the electrolyte described in Patent Document 1 has not yet been satisfactory in terms of suppressing capacity deterioration and gas generation during high temperature storage.

  The present invention has been made to solve the above problems, and in a non-aqueous electrolyte battery, a non-aqueous electrolyte that suppresses capacity deterioration and gas generation during high-temperature storage, and the non-aqueous electrolyte It is an object of the present invention to provide a used non-aqueous electrolyte battery.

（一般式（１）中、Ｒ_１およびＲ_２はそれぞれ独立して、水素原子、フッ素原子、またはフッ素原子で置換されていてもよい炭素数１〜１２の炭化水素基を表し、Ｘは炭素数１〜１２の２価の連結基を表す。）
（２） 非水系電解液に占める一般式（１）で表される化合物の割合が、０．００１〜１
０質量％である、上記（１）に記載の非水系電解液。
（３） 更に、炭素−炭素不飽和結合を有する環状カーボネート化合物、フッ素原子を有
する環状カーボネート化合物、モノフルオロリン酸塩およびジフルオロリン酸塩からなる群より選ばれる少なくとも一種を含有する、上記（１）または（２）に記載の非水系電解液。
（４） リチウムイオンを吸蔵・放出可能な負極及び正極、並びに非水系電解液を含む非
水系電解液電池であって、該非水系電解液が上記（１）乃至（３）のいずれかに記載の非水系電解液であることを特徴とする非水系電解液電池。 As a result of various studies to achieve the above object, the present inventors have found that the above problems can be solved by including a compound having a specific structure in the electrolytic solution, thereby completing the present invention. It came to.
That is, the gist of the present invention is as follows.
(1) In a non-aqueous electrolyte solution containing an electrolyte and a non-aqueous solvent, the non-aqueous electrolyte solution has the general formula (1
The non-aqueous electrolyte solution characterized by containing the compound represented by this.

(In General Formula (1), R ₁ and R ₂ each independently represent a hydrogen atom, a fluorine atom, or a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a fluorine atom, and X is carbon. Represents a divalent linking group of formula 1-12.
(2) The proportion of the compound represented by the general formula (1) in the non-aqueous electrolyte is 0.001-1.
The nonaqueous electrolytic solution according to (1) above, which is 0% by mass.
(3) The above (1) further containing at least one selected from the group consisting of a cyclic carbonate compound having a carbon-carbon unsaturated bond, a cyclic carbonate compound having a fluorine atom, a monofluorophosphate, and a difluorophosphate. ) Or the non-aqueous electrolyte solution according to (2).
(4) A non-aqueous electrolyte battery including a negative electrode and a positive electrode capable of inserting and extracting lithium ions, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution is any one of (1) to (3) above A non-aqueous electrolyte battery characterized by being a non-aqueous electrolyte.

  According to the present invention, it is possible to provide a non-aqueous electrolyte battery that has a high capacity, generates less gas, and has excellent high-temperature storage characteristics, and can achieve downsizing and high performance of the non-aqueous electrolyte battery. it can.

  Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented without departing from the gist of the present invention.

<Non-aqueous electrolyte>
The non-aqueous electrolyte solution of the present invention, like a general non-aqueous electrolyte solution, usually has an electrolyte and a non-aqueous solvent that dissolves it as a main component, and is further represented by the general formula (1). The compound to be contained is contained.

In General Formula (1), R ₁ and R ₂ each independently represent a hydrogen atom, a fluorine atom, or a hydrocarbon group having 1 to 12 carbon atoms that may be substituted with a fluorine atom, and X is the number of carbon atoms 1 to 12 divalent linking groups are represented.

As a C1-C12 hydrocarbon group which may be substituted by the fluorine atom, a C1-C12 alkyl group, a C2-C12 alkenyl group, a C6-C12 aryl group, or carbon Examples thereof include aralkyl groups of 7 to 12.
Examples of the alkyl group having 1 to 12 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, pentyl group, A cyclopentyl group, a cyclohexyl group, etc. are mentioned, Preferably it is a C1-C6, Especially preferably, it is a 1-4 chain or cyclic alkyl group, However, It is preferable that it is a chain alkyl group.
As a C2-C12 alkenyl group, a vinyl group, a propenyl group, etc. are mentioned, Preferably it is 2-8, Most preferably, the thing of 2-4 is mentioned.
Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a cyclohexylphenyl group, and a t-butylphenyl group, and among them, a phenyl group is preferable.
Examples of the aralkyl group having 7 to 12 carbon atoms include a benzyl group and a phenethyl group, and among them, a benzyl group is preferable.
The alkyl group, alkenyl group, aryl group and aralkyl group may be substituted with a fluorine atom. Examples of the fluorine-substituted group include a trifluoromethyl group, a trifluoroethyl group and a pentafluoroethyl group. Fluorinated alkyl groups, 2-fluorovinyl groups, fluorinated alkenyl groups such as 3-fluoro-2-propenyl group, 2-fluorophenyl groups, 3-fluorophenyl groups, fluorinated aryl groups such as 4-fluorophenyl groups, Examples thereof include fluorinated aralkyl groups such as 2-fluorobenzyl group, 3-fluorobenzyl group and 4-fluorobenzyl group.

Among these, in general formula (1), R ₁ and R ₂ are more preferably any one of a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms, and a hydrogen atom or an alkyl having 1 to 12 carbon atoms. It is more preferably any of groups, and particularly preferably a hydrogen atom.

Although it does not specifically limit as a C1-C12 bivalent coupling group represented by X in General formula (1), For example, a bivalent hydrocarbon group is mentioned and it is C2-C9 Is more preferable.
Specific examples include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, and an octamethylene group. In these divalent hydrocarbon groups, a part of hydrogen atoms may be substituted with other alkyl groups.

  The molecular weight of the compound represented by the general formula (1) is usually 102 or more, usually 2000 or less, preferably 1000 or less, more preferably 500 or less.

  Specific examples of the compound represented by the general formula (1) include the following compounds.

Among the above compounds, R ₁ and R ₂ in the general formula (1) are a hydrogen atom, a fluorine atom, or an alkyl having 1 to 12 carbon atoms from the viewpoint of suppressing capacity deterioration and gas generation during high-temperature storage. More preferably, it is either a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and particularly preferably a hydrogen atom.

The compound represented by the general formula (1) may be used alone or in combination of two or more.
The proportion of the compound represented by the general formula (1) in the non-aqueous electrolyte is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, still more preferably 0.05% by mass or more, particularly Preferably it is 0.1 mass% or more. If the concentration is lower than this, the effects of the present invention may not be easily exhibited. On the other hand, if the concentration is too high, the capacity of the battery may decrease. Therefore, it is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 2% by mass, and particularly preferably 1% by mass or less. Preferably it is 0.8 mass% or less.

The reason why the non-aqueous electrolyte solution according to the present invention is low in gas generation and excellent in high-temperature storage characteristics is not clear, and the present invention is not limited to the following operation principle, but is presumed as follows. .
First, the compound represented by the general formula (1) has two NH (C═O) groups in the molecule, and the hydrogen of the NH (C═O) group is easily deprotonated on the surface of the positive electrode. It is speculated that this generates two active species in the molecule, and promptly forms a stable protective layer. It seems that this protective layer prevents contact between the highly active positive electrode and the electrolytic solution component, suppresses side reactions between the positive electrode and the electrolytic solution component, suppresses deterioration of the positive electrode, and suppresses gas generation.

(Electrolytes)
There is no restriction | limiting in the electrolyte used for the non-aqueous electrolyte of this invention, A well-known thing can be used arbitrarily if it is used as an electrolyte for the target non-aqueous electrolyte battery.
When the nonaqueous electrolytic solution of the present invention is used for a lithium secondary battery, a lithium salt is usually used as an electrolyte.
Specific examples of the lithium _{salt, LiPF 6, LiBF 4, LiClO} 4, LiAlF 4, LiSbF 6, inorganic lithium salts LiTaF 6, LiWF ₇ and the like;
HCO ₂ Li, CH ₃ CO ₂ Li, CH ₂ FCO ₂ Li, CHF ₂ CO ₂ Li, CF ₃ CO ₂ Li, CF ₃ CH ₂ CO ₂ Li, CF ₃ CF ₂ CO ₂ Li, CF ₃ CF ₂ CF ₂ Carboxylic acid lithium salts such as CO ₂ Li, CF ₃ CF ₂ CF ₂ CF ₂ CO ₂ Li;
FSO ₃ Li, CH ₃ SO ₃ Li, CH ₂ FSO ₃ Li, CHF ₂ SO ₃ Li, CF ₃ SO ₃ Li, CF ₃ CF ₂ SO ₃ Li, CF ₃ CF ₂ CF ₂ SO ₃ Li, CF ₃ CF ₂ Sulfonic acid lithium salts such as CF ₂ CF ₂ SO ₃ Li;
LiN (FCO) ₂ , LiN (FCO) (FSO ₂ ), LiN (FSO ₂ ) ₂ , LiN (FSO ₂ ) (CF ₃ SO ₂ ), LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , Lithium imide salts such as lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropane disulfonylimide, LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ) ;
Lithium metide salts such as LiC (FSO ₂ ) ₃ , LiC (CF ₃ SO ₂ ) ₃ , LiC (C ₂ F ₅ SO ₂ ) ₃ ;
Lithium oxalatoborate salts such as lithium difluorooxalatoborate and lithium bis (oxalato) borate;
Lithium oxalate phosphate salts such as lithium tetrafluorooxalatophosphate, lithium difluorobis (oxalato) phosphate, lithium tris (oxalato) phosphate;
In addition, LiPF ₄ (CF ₃ ) ₂ , LiPF ₄ (C ₂ F ₅ ) ₂ , LiPF ₄ (CF ₃ SO ₂ ) ₂ , LiPF ₄ (C ₂ F ₅ SO ₂ ) ₂ , LiBF ₃ CF ₃ , LiBF ₃ C _{2 F 5, LiBF 3 C 3} F 7, LiBF 2 (CF 3) 2, LiBF 2 (C 2 F 5) 2, LiBF 2 (CF 3 SO 2) 2, LiBF 2 (C 2 F 5 SO 2) 2 Fluorine-containing organic lithium salts such as;
Among these, LiPF ₆ , LiBF ₄ , LiFSO ₃ , LiCF ₃ SO ₃ , LiN (FSO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , lithium cyclic 1,2 -Tetrafluoroethane disulfonylimide, lithium cyclic 1,3-hexafluoropropane disulfonylimide, lithium bis (oxalato) borate, lithium difluorooxalatoborate, lithium tris (oxalato) phosphate, lithium difluorobis (oxalato) phosphate, lithium Tetrafluorooxalatophosphate is preferable, and LiPF ₆ and LiBF ₄ are particularly preferable.

Moreover, these lithium salts may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Among them, the combined use of specific inorganic lithium salts and the combined use of inorganic lithium salts and lithium sulfonic acid salts, lithium imide salts, lithium oxalate borate salts and lithium oxalate phosphate salts suppresses gas generation during high-temperature storage, Or since deterioration after high-temperature storage is suppressed, it is preferable.
In particular, the combined use of LiPF ₆ and LiBF ₄ , LiPF ₆ , LiFSO ₃ , LiCF ₃ SO ₃ , LiN (FSO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , Lithium cyclic 1,2-tetrafluoroethanedisulfonylimide, lithium cyclic 1,3-hexafluoropropane disulfonylimide, lithium bis (oxalato) borate, lithium difluorooxalatoborate, lithium tris (oxalato) phosphate, lithium difluorobis It is preferable to use in combination with a lithium salt selected from (oxalato) phosphate and lithium tetrafluorooxalate phosphate.

When used in combination LiPF ₆ and LiBF ₄ are the content of LiBF ₄ to the total of LiPF ₆ and LiBF ₄ is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, more preferably It is 0.1% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and particularly preferably 3% by mass or less. If it is less than this range, the desired effect may not be obtained, and if it exceeds this range, battery characteristics such as high load discharge characteristics may deteriorate.
On the other hand, LiPF ₆ , LiFSO ₃ , LiCF ₃ SO ₃ , LiN (FSO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , lithium cyclic 1,2-tetrafluoroethane Disulfonylimide, lithium cyclic 1,3-hexafluoropropane disulfonylimide, lithium bis (oxalato) borate, lithium difluorooxalatoborate, lithium tris (oxalato) phosphate, lithium difluorobis (oxalato) phosphate, lithium tetrafluorooxalato When a lithium salt selected from phosphates is used in combination, the content ratio of LiPF _{6 in} the total of both is preferably 70% by mass or more, more preferably 80% by mass or more, and further preferably 85% by mass or more, Is 99 The amount% or less, more preferably less 95 wt%.

  The concentration of these electrolytes in the non-aqueous electrolyte solution is not particularly limited in order to exhibit the effects of the present invention, but is preferably 0.5 mol / liter or more, more preferably 0.8 mol / liter or more. More preferably, it is 1.0 mol / liter or more. Further, it is preferably 3 mol / liter or less, more preferably 2 mol / liter or less, still more preferably 1.8 mol / liter or less, and particularly preferably 1.6 mol / liter or less. If the concentration is too low, the electrical conductivity of the electrolyte solution may be insufficient. On the other hand, if the concentration is too high, the electrical conductivity may decrease due to an increase in viscosity, and the battery performance may decrease. .

(Non-aqueous solvent)
The non-aqueous solvent can also be appropriately selected from conventionally known solvents for non-aqueous electrolyte solutions. For example, cyclic carbonates, chain carbonates, cyclic carboxylic acid esters, chain carboxylic acid esters, cyclic ethers, chain ethers, sulfur-containing organic solvents, phosphorus-containing organic solvents, aromatic fluorine-containing solvents, etc. Can be mentioned.

Examples of the cyclic carbonates include alkylene carbonates having an alkylene group having 2 to 4 carbon atoms such as ethylene carbonate, propylene carbonate, and butylene carbonate. Among these, ethylene carbonate and propylene carbonate are preferable from the viewpoint of improving battery characteristics. In particular, ethylene carbonate is preferred. Further, some or all of hydrogen in these compounds may be substituted with fluorine.

  Examples of cyclic carbonates substituted with fluorine include fluoroethylene carbonate, 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, tetrafluoroethylene carbonate, 1-fluoro- Such as 2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate, etc. Examples thereof include alkylene carbonates having an alkylene group substituted with fluorine having 2 to 4 carbon atoms. Among these, fluoroethylene carbonate and 1,2-difluoroethylene carbonate are preferable, and fluorocarbons are preferred. Ethylene carbonate is more preferable.

  As the chain carbonates, dialkyl carbonates are preferable, and the number of carbon atoms of the alkyl group constituting each is preferably 1 to 5, particularly preferably 1 to 4. Specifically, for example, symmetric chain alkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-n-propyl carbonate; asymmetric chain alkyls such as ethyl methyl carbonate, methyl-n-propyl carbonate, and ethyl-n-propyl carbonate Examples include carbonates, and among them, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are preferable from the viewpoint of improving battery characteristics. In addition, some or all of the alkyl group hydrogens may be substituted with fluorine. Examples of chain carbonates substituted with fluorine include bis (fluoromethyl) carbonate, bis (difluoromethyl) carbonate, bis (trifluoromethyl) carbonate, bis (2-fluoroethyl) carbonate, and bis (2,2-difluoroethyl). ) Carbonate, bis (2,2,2-trifluoroethyl) carbonate, 2-fluoroethyl methyl carbonate, 2,2-difluoroethyl methyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, and the like.

  Examples of the cyclic carboxylic acid esters include γ-butyrolactone, γ-valerolactone, and the like and compounds in which part or all of hydrogen of these compounds is substituted with fluorine.

Examples of chain carboxylates include methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, sec-butyl acetate, isobutyl acetate, t-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, propion Compounds in which part or all of hydrogen of these compounds such as isopropyl acid, methyl butyrate, ethyl butyrate, propyl butyrate, methyl valerate, ethyl valerate, etc. and propyl trifluoroacetate, butyl trifluoroacetate, etc. are substituted with fluorine, etc. And methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, and methyl valerate are more preferable.

  Examples of the cyclic ethers include tetrahydrofuran, 2-methyltetrahydrofuran and the like, and compounds obtained by substituting some or all of hydrogen of these compounds with fluorine.

Examples of chain ethers include dimethoxyethane, diethoxyethane, and the like, and compounds in which some or all of hydrogen in these compounds are substituted with fluorine, such as bis (trifluoroethoxy) ethane, ethoxytrifluoroethoxyethane, methoxytriflic. Fluoroethoxyethane, 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-trifluoromethyl-pentane, 1,1,1,2,2,3 , 4,5,5,5-decafluoro-3-ethoxy-4-trifluoromethyl-pentane, 1,1,1,2,2,3,4,5,5,5-decafluoro-3-propoxy -4-trifluoromethyl-pentane, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 2
, 2-difluoroethyl-2,2,3,3-tetrafluoropropyl ether and the like.

  Examples of the sulfur-containing organic solvent include sulfolane, 2-methylsulfolane, 3-methylsulfolane, diethylsulfone, ethylmethylsulfone, methylpropylsulfone, and the like, and compounds in which part or all of hydrogen in these compounds is substituted with fluorine. .

  Phosphorus-containing organic solvents include trimethyl phosphate, triethyl phosphate, dimethyl ethyl phosphate, methyl diethyl phosphate, ethylene methyl phosphate, ethylene ethyl phosphate, etc., and some or all of the hydrogen in these compounds is replaced with fluorine. Compounds.

  Examples of the aromatic fluorine-containing solvent include fluorobenzene, difluorobenzene, trifluorobenzene, tetrafluorobenzene, pentafluorobenzene, hexafluorobenzene, benzotrifluoride and the like.

  These may be used alone or in combination of two or more, but it is preferable to use in combination of two or more. For example, it is preferable to use a high dielectric constant solvent such as cyclic carbonates or cyclic carboxylic acid esters in combination with a low viscosity solvent such as chain carbonates or chain carboxylic acid esters.

  One preferable combination of the non-aqueous solvents is a combination mainly composed of alkylene carbonate and dialkyl carbonate. Among them, the total of alkylene carbonate and dialkyl carbonate in the non-aqueous solvent is preferably 70% by volume or more, more preferably 80% by volume or more, still more preferably 90% by volume or more, and the alkylene carbonate and the dialkyl carbonate. The proportion of alkylene carbonate with respect to the total amount of is preferably 5% by volume or more, more preferably 10% by volume or more, still more preferably 15% by volume or more, preferably 50% by volume or less, more preferably 35% by volume or less, still more preferably Is 30% by volume or less, particularly preferably 25% by volume or less. When a combination of these non-aqueous solvents is used, the balance between the cycle characteristics and high-temperature storage characteristics (particularly, the remaining capacity and high-load discharge capacity after high-temperature storage) of a battery produced using the non-aqueous solvent may be improved.

  As the alkylene carbonate, ethylene carbonate, propylene carbonate, and fluoroethylene carbonate are preferable from the viewpoint of improving the cycle characteristics and high-temperature storage characteristics of the battery.

Specific examples of preferred combinations of ethylene carbonate and dialkyl carbonate include ethylene carbonate and dimethyl carbonate, ethylene carbonate and diethyl carbonate, ethylene carbonate and ethyl methyl carbonate, ethylene carbonate and dimethyl carbonate and diethyl carbonate, ethylene carbonate and dimethyl carbonate and ethyl methyl. Examples thereof include carbonate, ethylene carbonate, diethyl carbonate and ethyl methyl carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.
A combination in which propylene carbonate is further added to a combination of these ethylene carbonate and dialkyl carbonates is also mentioned as a preferable combination.

In the case of containing propylene carbonate, the volume ratio of ethylene carbonate to propylene carbonate is preferably 99: 1 to 40:60, particularly preferably 95: 5 to 50:50. Furthermore, the proportion of propylene carbonate in the entire non-aqueous solvent is preferably 0.1% by volume or more, more preferably 1% by volume or more, still more preferably 2% by volume or more, and preferably 20% by volume or less, more preferably Is 8% by volume or less, more preferably 5% by volume or less. It is preferable to contain propylene carbonate in this concentration range because the low temperature characteristics may be further improved while maintaining the combination characteristics of ethylene carbonate and dialkyl carbonate.

  Among the combinations of ethylene carbonate and dialkyl carbonate, those containing asymmetrical chain alkyl carbonates as dialkyl carbonate are more preferred, especially ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate, ethylene carbonate, diethyl carbonate and ethyl methyl carbonate. Those containing ethylene carbonate, symmetric chain alkyl carbonates, and asymmetric chain alkyl carbonates such as ethylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are preferred because of a good balance between cycle characteristics and large current discharge characteristics. Among them, the asymmetric chain alkyl carbonate is preferably ethyl methyl carbonate, and the alkyl group of the alkyl carbonate preferably has 1 to 2 carbon atoms.

Specific examples of preferred combinations of fluoroethylene carbonate and dialkyl carbonate include fluoroethylene carbonate and dimethyl carbonate, fluoroethylene carbonate and diethyl carbonate, fluoroethylene carbonate and ethyl methyl carbonate, fluoroethylene carbonate and dimethyl carbonate and diethyl carbonate, and fluoroethylene carbonate. And dimethyl carbonate and ethyl methyl carbonate, fluoroethylene carbonate, diethyl carbonate and ethyl methyl carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.
A combination obtained by further adding ethylene carbonate and / or propylene carbonate to the combination of these fluoroethylene carbonate and dialkyl carbonate is also mentioned as a preferable combination.

When diethyl carbonate is contained in the non-aqueous solvent, the proportion of diethyl carbonate in the total non-aqueous solvent is preferably 10% by volume or more, more preferably 20% by volume or more, and further preferably 25% by volume or more. In particular, it is 30% by volume or more, preferably 90% by volume or less, more preferably 80% by volume or less, still more preferably 75% by volume or less, and particularly preferably 70% by volume or less. And gas generation during high temperature storage may be suppressed.
Further, when dimethyl carbonate is contained in the non-aqueous solvent, the proportion of dimethyl carbonate in the total non-aqueous solvent is preferably 10% by volume or more, more preferably 20% by volume or more, and further preferably 25% by volume or more. In particular, it is 30% by volume or more, preferably 90% by volume or less, more preferably 80% by volume or less, still more preferably 75% by volume or less, and particularly preferably 70% by volume or less. As a result, the load characteristics of the battery may be improved.

  Above all, it contains dimethyl carbonate and ethyl methyl carbonate, and by increasing the content ratio of dimethyl carbonate over the content ratio of ethyl methyl carbonate, the battery characteristics after high-temperature storage are improved while ensuring the electrical conductivity of the electrolyte. This is preferable.

  The volume ratio of dimethyl carbonate to ethyl methyl carbonate in all non-aqueous solvents (dimethyl carbonate / ethyl methyl carbonate) is 1.1 or more in terms of improving the electric conductivity of the electrolyte and improving the battery characteristics after storage. Is preferably 1.5 or more, more preferably 2.5 or more. The volume ratio (dimethyl carbonate / ethyl methyl carbonate) is preferably 40 or less, more preferably 20 or less, still more preferably 10 or less, and particularly preferably 8 or less, from the viewpoint of improving battery characteristics at low temperatures.

  Further, in the combination mainly composed of the alkylene carbonates and dialkyl carbonates, cyclic carbonates other than the alkylene carbonates and dialkyl carbonates, chain carbonates, cyclic carboxylic acid esters, chain carboxylic acid esters, Other solvents such as cyclic ethers, chain ethers, sulfur-containing organic solvents, phosphorus-containing organic solvents, and aromatic fluorine-containing solvents may be mixed.

Another example of the preferred non-aqueous solvent is an organic solvent selected from the group consisting of ethylene carbonate, propylene carbonate and butylene carbonate, or a mixed solvent consisting of two or more organic solvents selected from the group. It occupies 60% by volume or more. A non-aqueous electrolyte using this mixed solvent may reduce solvent evaporation and liquid leakage even when used at high temperatures. Among them, the total of ethylene carbonate and propylene carbonate in the non-aqueous solvent is preferably 70% by volume or more, more preferably 80% by volume or more, still more preferably 90% by volume or more, and the volume of ethylene carbonate and propylene carbonate. When the ratio is preferably 30:70 to 60:40, the balance between cycle characteristics and high-temperature storage characteristics may be improved.
In the present specification, the capacity of the non-aqueous solvent is a measured value at 25 ° C., but a measured value at the melting point is used for a solid at 25 ° C. such as ethylene carbonate.

(Other compounds)
The nonaqueous electrolytic solution according to the present invention is a cyclic carbonate compound having a carbon-carbon unsaturated bond, a cyclic carbonate compound having a fluorine atom, a monofluorophosphate, and a difluorophosphate within a range not impairing the effects of the present invention. Various other compounds such as at least one selected from the group consisting of the above and a conventionally known overcharge inhibitor may be contained as an auxiliary agent.
Among these, when containing at least one selected from the group consisting of a cyclic carbonate compound having a carbon-carbon unsaturated bond, a cyclic carbonate compound having a fluorine atom, a monofluorophosphate and a difluorophosphate, the negative electrode is stable. In order to form a simple film, the cycle characteristics and battery characteristics after high temperature storage may be improved, which is preferable.

((Cyclic carbonate compound having a carbon-carbon unsaturated bond))
Examples of the cyclic carbonate compound having a carbon-carbon unsaturated bond include vinylene carbonate, methyl vinylene carbonate, ethyl vinylene carbonate, 1,2-dimethyl vinylene carbonate, 1,2-diethyl vinylene carbonate, fluoro vinylene carbonate, trifluoromethyl. Vinylene carbonate compounds such as vinylene carbonate; vinyl ethylene carbonate, 1-methyl-2-vinylethylene carbonate, 1-ethyl-2-vinylethylene carbonate, 1-n-propyl-2-vinylethylene carbonate, 1,1-divinylethylene Vinyl ethylene carbonate compounds such as carbonate and 1,2-divinylethylene carbonate; ethynyl ethylene carbonate, 1-methyl-2-ethynyl ethylene car Ethenyl ethylene carbonate compounds such as 1-ethyl-2-ethynyl ethylene carbonate, 1,1-diethynyl ethylene carbonate, 1,2-diethynyl ethylene carbonate; 1,1-dimethyl-2-methylene ethylene carbonate, 1, Examples include methylene ethylene carbonate compounds such as 1-diethyl-2-methylene ethylene carbonate. Of these, vinylene carbonate, vinyl ethylene carbonate, 1,2-divinyl ethylene carbonate, and ethynyl ethylene carbonate are preferred from the viewpoint of improving cycle characteristics and capacity maintenance characteristics after high-temperature storage. Among them, vinylene carbonate, vinyl ethylene carbonate, ethynyl ethylene carbonate are preferred. Is more preferable, and vinylene carbonate is particularly preferable. These may be used alone or in combination of two or more.
When using 2 or more types together, it is preferable to use together vinylene carbonate and vinyl ethylene carbonate or ethynyl ethylene carbonate.

((Cyclic carbonate compound having fluorine atom))
Examples of the cyclic carbonate compound having a fluorine atom include fluoroethylene carbonate, 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, tetrafluoroethylene carbonate, 1- Fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate Etc. Of these, fluoroethylene carbonate and 1,2-difluoroethylene carbonate are preferable from the viewpoint of improving cycle characteristics and high-temperature storage characteristics. These may be used alone or in combination of two or more.
In addition, it may be used in combination with a cyclic carbonate compound having a carbon-carbon unsaturated bond and the monofluorophosphate and difluorophosphate described below. Is preferred.

((Monofluorophosphate and difluorophosphate))
The counter cation of monofluorophosphate and difluorophosphate is not particularly limited, but lithium, sodium, potassium, magnesium, calcium, and NR ¹ R ² R ³ R ⁴ (wherein R ^{1 to} R ⁴ Are each independently a hydrogen atom or an organic group having 1 to 12 carbon atoms.)

Although there is no particular limitation on the organic group having 1 to 12 carbon atoms represented by R ¹ to R ⁴ of the above ammonium, for example, which may be substituted with a halogen atom an alkyl group, substituted with a halogen atom or an alkyl group Examples thereof include an cycloalkyl group which may be substituted, an aryl group which may be substituted with a halogen atom or an alkyl group, and a nitrogen atom-containing heterocyclic group which may have a substituent. Among these, as R ^{1 to} R ⁴ , a hydrogen atom, an alkyl group, a cycloalkyl group, or a nitrogen atom-containing heterocyclic group is preferable.

  Specific examples of monofluorophosphate and difluorophosphate include lithium monofluorophosphate, sodium monofluorophosphate, potassium monofluorophosphate, tetramethylammonium monofluorophosphate, tetraethylammonium monofluorophosphate, difluoro Examples include lithium phosphate, sodium difluorophosphate, potassium difluorophosphate, tetramethylammonium difluorophosphate, tetraethylammonium difluorophosphate, etc., preferably lithium monofluorophosphate and lithium difluorophosphate, more preferably lithium difluorophosphate. preferable. These may be used alone or in combination of two or more.

  Moreover, you may use together with the cyclic carbonate compound which has a carbon-carbon unsaturated bond, and the cyclic carbonate compound which has a fluorine atom, and it is preferable to use together from the point of a cycling characteristic improvement or the characteristic improvement after high temperature storage.

  When the non-aqueous electrolyte contains a cyclic carbonate compound having a carbon-carbon unsaturated bond, the proportion in the non-aqueous electrolyte is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, More preferably, it is 0.1 mass% or more, Most preferably, it is 0.3 mass% or more. If the proportion of the cyclic carbonate compound having a carbon-carbon unsaturated bond is too small, the effect of improving the cycle characteristics of the battery and the capacity maintenance characteristics after high-temperature storage may not be sufficiently exhibited. However, if the ratio of the cyclic carbonate compound having a carbon-carbon unsaturated bond is too large, the amount of gas generated may increase during storage at high temperatures, or the discharge characteristics at low temperatures may decrease. More preferably, it is 4 mass% or less, More preferably, it is 3 mass% or less.

  When the non-aqueous electrolyte contains a cyclic carbonate compound having a fluorine atom as an auxiliary agent, the proportion in the non-aqueous electrolyte is preferably 0.001% by mass or more, more preferably 0.1% by mass or more, and further Preferably it is 0.3% by mass or more, particularly preferably 0.5% by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 4% by mass or less, particularly preferably 3% by mass. It is as follows. If the ratio is less than the above range, there is a possibility that the effect of improving the cycle characteristics and high temperature storage characteristics of the battery may not be sufficiently exhibited.If the ratio exceeds the above range, the amount of gas generated during high temperature storage may increase, The discharge characteristics may deteriorate.

  When the non-aqueous electrolyte contains a monofluorophosphate and / or difluorophosphate, the proportion in the non-aqueous electrolyte is preferably 0.001% by mass or more, more preferably 0.01% by mass or more. More preferably, it is 0.1% by mass or more, particularly preferably 0.2% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 2% by mass or less. If the ratio is less than the above range, there is a possibility that the effect of improving the cycle characteristics and high-temperature storage characteristics of the battery may not be sufficiently exhibited. If the ratio exceeds the above range, it becomes difficult to dissolve in the electrolytic solution, and the effect is saturated. Tend.

Conventionally known overcharge inhibitors include alkylbiphenyls such as biphenyl, 2-methylbiphenyl, 2-ethylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclopentylbenzene, cyclohexylbenzene, cis-1-propyl-4 -Phenylcyclohexane, trans-1-propyl-4-phenylcyclohexane, cis-1-butyl-4-phenylcyclohexane, trans-1-butyl-4-phenylcyclohexane, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran , Methylphenyl carbonate, ethylphenyl carbonate, diphenyl carbonate, triphenyl phosphate, tris (2-t-butylphenyl) phosphate, tris (3-t-
Butylphenyl) phosphate, tris (4-t-butylphenyl) phosphate, tris (2-t-amylphenyl) phosphate, tris (3-t-amylphenyl) phosphate, tris (4-t-amylphenyl) phosphate, tris Aromatic compounds such as (2-cyclohexylphenyl) phosphate, tris (3-cyclohexylphenyl) phosphate, tris (4-cyclohexylphenyl) phosphate; 2-fluorobiphenyl, 3-fluorobiphenyl, 4-fluorobiphenyl, 4,4 ′ -Partially fluorinated products of the above aromatic compounds such as difluorobiphenyl, 2,4-difluorobiphenyl, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene; 2,4-difluoroanisole, 2,5-difluoroanisole, 2,6 Difluoroanisole, fluorinated anisole compound such as 3,5-difluoro anisole, and the like.
Among these, alkylbiphenyl such as biphenyl and 2-methylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclopentylbenzene, cyclohexylbenzene, cis-1-propyl-4-phenylcyclohexane, trans-1-propyl-4- Phenylcyclohexane, cis-1-butyl-4-phenylcyclohexane, trans-1-butyl-4-phenylcyclohexane, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran, methylphenyl carbonate, diphenyl carbonate, triphenyl phosphate, Aromatic compounds such as tris (4-t-butylphenyl) phosphate and tris (4-cyclohexylphenyl) phosphate; 2-fluorobiphenyl, 3-fluorobiphenyl, 4 -Partially fluorinated products of the above aromatic compounds such as -fluorobiphenyl, 4,4'-difluorobiphenyl, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene, etc. are preferred. Partially hydrogenated terphenyl, cyclopentylbenzene, cyclohexylbenzene, Cis-1-propyl-4-phenylcyclohexane, trans-1-propyl-4-phenylcyclohexane, cis-1-butyl-4-phenylcyclohexane, trans-1-butyl-4-phenylcyclohexane, t-butylbenzene, t -Amylbenzene, methylphenyl carbonate, diphenyl carbonate, triphenyl phosphate, tris (4-tert-butylphenyl) phosphate, tris (4-cyclohexylphenyl) phosphate, o-cyclohexyl Fluorobenzene, more preferably p- cyclohexyl fluorobenzene, partially hydrogenated member and cyclohexylbenzene terphenyl is particularly preferred.
Two or more of these may be used in combination. When two or more types are used in combination, in particular, a partially hydrogenated terphenyl, a combination of cyclohexylbenzene and t-butylbenzene or t-amylbenzene, or a partially hydrogenated biphenyl, alkylbiphenyl, terphenyl or terphenyl. It is overcharged to use together those selected from oxygen-free aromatic compounds such as cyclohexylbenzene, t-butylbenzene and t-amylbenzene and those selected from oxygen-containing aromatic compounds such as diphenyl ether and dibenzofuran. This is preferable from the viewpoint of the balance between prevention characteristics and high-temperature storage characteristics.

  The content ratio of these overcharge inhibitors in the non-aqueous electrolyte is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, still more preferably 0.3% by mass or more, and particularly preferably 0%. 0.5% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, and still more preferably 2% by mass or less. If the concentration is too low, the desired effect of the overcharge inhibitor may hardly be exhibited. On the other hand, if the concentration is too high, battery characteristics such as high-temperature storage characteristics tend to deteriorate.

Other auxiliaries include carbonate compounds such as erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl-methyl carbonate, methoxyethyl-ethyl carbonate, ethoxyethyl-methyl carbonate, ethoxyethyl-ethyl carbonate; succinic anhydride Carboxylic acids such as glutaric anhydride, maleic anhydride, itaconic anhydride, citraconic anhydride, glutaconic anhydride, diglycolic anhydride, cyclohexanedicarboxylic anhydride, cyclopentanetetracarboxylic dianhydride and phenylsuccinic anhydride Anhydride: dimethyl succinate, diethyl succinate, diallyl succinate, dimethyl maleate, diethyl maleate, diallyl maleate, dipropyl maleate, dibutyl maleate, bis maleate (trifluoro Dicarboxylic acid diester compounds such as bis (pentafluoroethyl) maleate, bis (2,2,2-trifluoroethyl) maleate; 2,4,8,10-tetraoxaspiro [5.5] undecane Spiro compounds such as 3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane; ethylene sulfite, propylene sulfite, 1,3-propane sultone, 1,4-butane sultone, 1,3-propene sultone, 1,4-butene sultone, methyl methanesulfonate, ethyl methanesulfonate, methyl-methoxymethanesulfonate, methyl-2-methoxyethanesulfonate, busulfan, diethylene glycol dimethanesulfonate, 1,2-ethanediol bis ( 2,2,2-trifluoroethane Sulfonate), 1,4-butanediol bis (2,2,2-trifluoroethanesulfonate), sulfolane, 3-sulfolene, 2-sulfolene, dimethylsulfone, diethylsulfone, divinylsulfone, diphenylsulfone, bis (methylsulfonyl) Methane, bis (methylsulfonyl) ethane, bis (ethylsulfonyl) methane, bis (ethylsulfonyl) ethane, bis (vinylsulfonyl) methane, bis (vinylsulfonyl) ethane, N, N-dimethylmethanesulfonamide, N, N- Sulfur-containing compounds such as diethylmethanesulfonamide, N, N-dimethyltrifluoromethanesulfonamide, N, N-diethyltrifluoromethanesulfonamide; 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl- 2-o Nitrogen-containing compounds such as xazolidinone, 1,3-dimethyl-2-imidazolidinone and N-methylsuccinimide; heptane, octane, nonane, decane, cycloheptane, methylcyclohexane, ethylcyclohexane, propylcyclohexane, n-butylcyclohexane , T-butylcyclohexane, dicyclohexyl and other hydrocarbon compounds; fluorobenzene, difluorobenzene, pentafluorobenzene, hexafluorobenzene and other fluorinated benzenes; 2-fluorotoluene, 3-fluorotoluene, 4-fluorotoluene, benzotrifluoride Such as fluorinated toluene; acetonitrile, propionitrile, butyronitrile, malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeonitrile, 3,9-bis ( -Cyanoethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane and other nitrile compounds; methyl isocyanate, ethyl isocyanate, propyl isocyanate, butyl isocyanate, pentyl isocyanate, hexyl isocyanate, vinyl isocyanate, allyl isocyanate, Ethynyl isocyanate, propynyl isocyanate, phenyl isocyanate, monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, 1,2-bis (isocyanatomethyl) ) Cyclohexane, 1,3-bis (i Isocyanate compounds such as cyanatomethyl) cyclohexane and 1,4-bis (isocyanatomethyl) cyclohexane; methyldimethylphosphinate, ethyldimethylphosphinate, ethyldiethylphosphinate, trimethylphosphonoformate, triethylphosphonoformate, trimethylphosphono Examples thereof include phosphorus-containing compounds such as acetate, triethylphosphonoacetate, trimethyl-3-phosphonopropionate, and triethyl-3-phosphonopropionate.
Among these, ethylene sulfite, 1,3-propane sultone, 1,4-butane sultone, 1,3-propene sultone, 1,4-butene sultone, busulfan, 1,4 in terms of improving battery characteristics after high-temperature storage -Sulfur-containing compounds such as butanediol bis (2,2,2-trifluoroethanesulfonate); acetonitrile, propionitrile, butyronitrile, malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, 3,9-bis ( Nitrile compounds such as 2-cyanoethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane are preferred. Two or more of these may be used in combination.

  The content ratio of these auxiliaries in the non-aqueous electrolyte solution is not particularly limited, but is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further preferably 0.2% by mass or more. Yes, preferably 8% by mass or less, more preferably 5% by mass or less, still more preferably 3% by mass or less, and particularly preferably 1% by mass or less. The addition of these auxiliaries is preferable in terms of improving capacity maintenance characteristics and cycle characteristics after high-temperature storage. If the concentration is lower than this lower limit, the effect of the auxiliary agent may be hardly exhibited. Conversely, if the concentration is too high, battery characteristics such as high load discharge characteristics may be degraded.

(Preparation of electrolyte)
The nonaqueous electrolytic solution according to the present invention can be prepared by dissolving an electrolyte, a compound represented by the general formula (1), and if necessary, other compounds in a nonaqueous solvent. In preparing the non-aqueous electrolyte solution, each raw material is preferably dehydrated in advance in order to reduce the water content when the electrolyte solution is used. The dehydration is preferably performed to 50 ppm or less, more preferably 30 ppm or less, and even more preferably 10 ppm or less. Moreover, you may implement dehydration, a deoxidation process, etc. after electrolyte solution preparation.

  The non-aqueous electrolyte solution of the present invention is suitable for use as a non-aqueous electrolyte solution for a secondary battery, that is, a non-aqueous electrolyte secondary battery, for example, a lithium secondary battery, among non-aqueous electrolyte batteries. Hereinafter, a non-aqueous electrolyte secondary battery using the non-aqueous electrolyte of the present invention will be described.

<Non-aqueous electrolyte secondary battery>
The non-aqueous electrolyte secondary battery of the present invention is a non-aqueous electrolyte battery including a negative electrode and a positive electrode capable of occluding and releasing lithium ions, and a non-aqueous electrolyte, and the non-aqueous electrolyte is a non-aqueous electrolyte of the present invention. It is an aqueous electrolyte solution.

(Battery configuration)
The non-aqueous electrolyte secondary battery according to the present invention can occlude and release lithium ions as in the case of a conventionally known non-aqueous electrolyte secondary battery except that it is produced using the non-aqueous electrolyte of the present invention. A non-aqueous electrolyte battery including a negative electrode and a positive electrode and a non-aqueous electrolyte solution. Usually, the positive electrode and the negative electrode are accommodated in a case through a porous film impregnated with the non-aqueous electrolyte solution of the present invention. can get. Therefore, the shape of the non-aqueous electrolyte secondary battery of the present invention is not particularly limited, and may be any of a cylindrical shape, a square shape, a laminate shape, a coin shape, a large size, and the like.

(Negative electrode active material)
The negative electrode active material is not particularly limited as long as it can occlude and release lithium ions. Specific examples thereof include carbonaceous materials, alloy-based materials, lithium-containing metal composite oxide materials, and the like.
These negative electrode active materials may be used alone or in combination of two or more.
Of these, carbonaceous materials and alloy materials are preferred.

  Among the carbonaceous materials, amorphous carbon materials, graphite, and those in which the surface of graphite is coated with amorphous carbon compared to graphite are preferred, and in particular, the surface of graphite or graphite is amorphous compared to graphite. Those coated with carbon are generally preferred because of their high energy density.

  Graphite preferably has a lattice plane (002 plane) d value (interlayer distance) of 0.335 to 0.338 nm, particularly 0.335 to 0.337 nm, as determined by X-ray diffraction using the Gakushin method. The crystallite size (Lc) determined by X-ray diffraction by the Gakushin method is preferably 10 nm or more, more preferably 50 nm or more, and still more preferably 100 nm or more. The ash content is preferably 1% by mass or less, more preferably 0.5% by mass or less, and still more preferably 0.1% by mass or less.

  The graphite surface coated with amorphous carbon is preferably graphite having a d-value of 0.335 to 0.338 nm on the lattice plane (002 plane) in X-ray diffraction as a core material. A carbonaceous material having a larger d-value on the lattice plane (002 plane) in X-ray diffraction than the core material is attached, and the d-value on the lattice plane (002 plane) in X-ray diffraction is greater than that of the core material and the core material. The ratio with respect to the carbonaceous material having a large is 99/1 to 80/20 in mass ratio. When this is used, a negative electrode having a high capacity and hardly reacting with the electrolytic solution can be produced.

  The particle size of the carbonaceous material is a median diameter by a laser diffraction / scattering method, preferably 1 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more, particularly preferably 7 μm or more, preferably 100 μm or less, more preferably Is 50 μm or less, more preferably 40 μm or less, and particularly preferably 30 μm or less.

The specific surface area of the carbonaceous material by the BET method is preferably 0.3 m ² / g or more, more preferably 0.5 m ² / g or more, still more preferably 0.7 m ² / g or more, and particularly preferably 0.8 m ^2. / g or more, preferably 25.0 m ² / g or less, more preferably 20.0 m ² / g or less, more preferably 15.0 m ² / g or less, particularly preferably not more than 10.0 m ² / g .

Further, the carbonaceous material is analyzed by Raman spectrum using argon ion laser light, the peak is the peak intensity of the peak _{P A} in the range of 1570~1620cm ^-1 _I A, in the range of 1300~1400cm ^-1 P If the peak intensity of the _B was _{I B,} R value represented by the ratio of _{I B} and _{I a (= I B / I} a) is what is preferably in the range of 0.01 to 0.7. Further, the half width of the peak in the range of 1570～1620Cm ^-1 is, 26cm ^-1 or less, are preferred in particular 25 cm ^-1 or less.

  The alloy material is not particularly limited as long as it can occlude / release lithium, and single metals and alloys forming lithium alloys, or oxides, carbides, nitrides, silicides, sulfides, and phosphides thereof. Any of these compounds may be used. Preferably, it is a material containing a single metal and an alloy forming a lithium alloy, more preferably a material containing a group 13 and group 14 metal / metalloid element (that is, excluding carbon), and further, aluminum, silicon, and It is preferably a simple metal of tin (which may be hereinafter referred to as “specific metal element”), and an alloy or compound containing these elements.

  Examples of the negative electrode active material having at least one element selected from specific metal elements include a single metal element of any one specific metal element, an alloy composed of two or more specific metal elements, one type, or two or more types An alloy composed of the specific metal element and one or more other metal elements, a compound containing one or more specific metal elements, and oxides, carbides, nitrides of the compounds, Examples include composite compounds such as silicides, sulfides, and phosphides. By using these simple metals, alloys or metal compounds as the negative electrode active material, the capacity of the battery can be increased.

  Moreover, the compound which these complex compounds combined with several elements, such as a metal simple substance, an alloy, or a nonmetallic element, can also be mentioned as an example. More specifically, for example, in silicon and tin, an alloy of these elements and a metal that does not operate as a negative electrode can be used. In addition, for example, in the case of tin, a complex compound containing 5 to 6 kinds of elements in combination with a metal that acts as a negative electrode other than tin and silicon, a metal that does not operate as a negative electrode, and a nonmetallic element can also be used. .

  Among these negative electrode active materials, since the capacity per unit mass is large when a battery is formed, any one metal element of a specific metal element, an alloy of two or more specific metal elements, oxidation of a specific metal element A material, carbide, nitride or the like is preferable, and silicon and / or tin metal alone, an alloy, an oxide, carbide, nitride, or the like is particularly preferable because of its large capacity per unit mass.

In addition, although the capacity per unit mass is inferior to that of using a single metal or an alloy, the following compounds containing silicon and / or tin are also preferred because of excellent cycle characteristics.
The element ratio of silicon and / or tin to oxygen is preferably 0.5 or more, more preferably 0.7 or more, still more preferably 0.9 or more, and preferably 1.5 or less, more preferably Silicon and / or tin oxides of 1.3 or less, more preferably 1.1 or less.
The element ratio of silicon and / or tin and nitrogen is preferably 0.5 or more, more preferably 0.7 or more, still more preferably 0.9 or more, and preferably 1.5 or less, more preferably Silicon and / or tin nitride of 1.3 or less, more preferably 1.1 or less.
The element ratio of silicon and / or tin to carbon is preferably 0.5 or more, more preferably 0.7 or more, still more preferably 0.9 or more, and preferably 1.5 or less, more preferably Silicon and / or tin carbides of 1.3 or less, more preferably 1.1 or less.

  These alloy materials may be in the form of powder or thin film, and may be crystalline or amorphous.

The average particle size of the alloy-based material is not particularly limited in order to exhibit the effects of the present invention, but is preferably 50 μm or less, more preferably 20 μm or less, still more preferably 10 μm or less, preferably 0.1 μm or more, More preferably, it is 1 micrometer or more, More preferably, it is 2 micrometers or more. If the particle size is too large, the expansion of the electrode is increased, and the cycle characteristics may be deteriorated. Moreover, when too small, it will become difficult to collect current, and capacity | capacitance may not fully express.

  The lithium-containing metal composite oxide material used as the negative electrode active material is not particularly limited as long as it can occlude and release lithium. However, a lithium-titanium composite oxide (hereinafter referred to as “lithium-titanium composite oxide”) (Abbreviated) is preferred.

  In addition, a part of lithium or titanium in the lithium titanium composite oxide is selected from the group consisting of other metal elements such as Na, K, Co, Al, Fe, Mg, Cr, Ga, Cu, Zn, and Nb. Those substituted with at least one element are also preferred.

Furthermore, it is a lithium titanium composite oxide represented by Li _x Ti _y M _z O ₄ , and 0.7 ≦ x ≦ 1.5, 1.5 ≦ y ≦ 2.3, and 0 ≦ z ≦ 1.6. It is preferable that the structure at the time of occlusion / release of lithium ions is stable (M is a group consisting of Na, K, Co, Al, Fe, Mg, Cr, Ga, Cu, Zn, and Nb). Represents at least one element selected).

Among them, when Z = 0 of the lithium titanium composite oxide represented by Li _x Ti _y M _z O ₄ , the structure in the case where x and y satisfy any of the following (a) to (c): This is preferable because of a good balance of battery performance.
(A) 1.2 ≦ x ≦ 1.4, 1.5 ≦ y ≦ 1.7, z = 0
(B) 0.9 ≦ x ≦ 1.1, 1.9 ≦ y ≦ 2.1, z = 0
(C) 0.7 ≦ x ≦ 0.9, 2.1 ≦ y ≦ 2.3, z = 0
More preferred representative compositions are Li _4/3 Ti _5/3 O ₄ in (a), Li ₁ Ti ₂ O ₄ in (b), and Li _4/5 Ti _11/5 O ₄ in (c). .
As for the structure when Z ≠ 0, for example, Li _4/3 Ti _4/3 Al _1/3 O ₄ is preferable.

(Positive electrode active material)
The positive electrode active material is not particularly limited as long as it can occlude and release lithium ions. A substance containing lithium and at least one transition metal is preferable, and examples thereof include a lithium transition metal composite oxide and a lithium-containing transition metal phosphate compound.

The transition metal of the lithium transition metal composite oxide is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu or the like. Specific examples include lithium-cobalt composite oxide such as LiCoO ₂ , LiNiO ₂ or the like. Examples of the lithium / nickel composite oxide include lithium / manganese composite oxides such as LiMnO ₂ , LiMn ₂ O ₄ , and Li ₂ MnO ₃ . In addition, a part of the transition metal atom that is the main component of the lithium transition metal composite oxide is replaced with another metal, that is, a part of Co in the lithium-cobalt composite oxide is replaced with Al, Ti, V, Cr. , Mn, Fe, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si substituted with other metals, part of Ni in the lithium-nickel composite oxide is Al, Ti, V, Cr, Substituted with other metals such as Mn, Fe, Co, Li, Cu, Zn, Mg, Ga, Zr, Si, and a part of Mn of the lithium-manganese composite oxide Al, Ti, V, Cr, Fe , Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si substituted with other metals, and the like. Among those in which a part of the transition metal atom that is the main component of the lithium transition metal composite oxide is substituted with another metal, LiNi _1-ab Mn _a Co _b O ₂ (a and b are numbers from 0 to less than 1) , Except for the case where both a and b are 0), LiNi _1-c- dE Co _C Al _d Mg _e O ₂ (c, d, e represents a number from 0 to less than 1, , d, excluding) is preferably the case of e are both 0, more _{LiNi 1-a-b Mn a} Co b O 2 (0 ≦ a <0.4,0 ≦ b <0.4), LiNi 1- _{c-d-e Co c Al} d Mg e O 2 (0 ≦ c <0.3,0 ≦ d <0.1,0 ≦ e <0.05) are preferred, in _{particular, LiNi} 1/3 _{Co 1 / 3} Mn _1/3 O ₂ , LiNi _0.5 Co _{0
. 3} Mn _0.2 O ₂ , LiNi _0.5 Mn _0.5 O ₂ , LiNi _0.85 Co _0.10 Al _0.05 O ₂ , LiNi _0.85 Co _0.10 Al _0.03 Mg _0.02 O ₂ is preferred.

As the transition metal of the lithium-containing transition metal phosphate compound, V, Ti, Cr, Mn, Fe, Co, Ni, Cu and the like are preferable, and specific examples include, for example, LiFePO ₄ , Li ₃ Fe ₂ (PO ₄ ). ₃ , iron phosphates such as LiFeP ₂ O _{7 and} cobalt phosphates such as LiCoPO ₄ . In addition, a part of the transition metal atom that is the main component of the lithium transition metal phosphate compound is substituted with another metal, that is, a part of Fe of iron phosphates is Al, Ti, V, Cr, Mn, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si and other metals substituted, Co cobalt phosphates part of Co Al, Ti, V, Cr, Mn, Fe , Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si substituted with other metals, and the like. These positive electrode active materials may be used alone or in combination.

  In addition, a material in which a substance (surface adhering substance) having a composition different from that of the substance constituting the main cathode active material is attached to the surface of the cathode active material can be used. Surface adhering substances include aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, bismuth oxide, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate And sulfates such as aluminum sulfate and carbonates such as lithium carbonate, calcium carbonate and magnesium carbonate.

  The amount of the surface adhering substance is not particularly limited in order to exhibit the effect of the present invention, but is preferably 0.1 ppm or more, more preferably 1 ppm or more, and still more preferably, by mass with respect to the positive electrode active material. It is used at 10 ppm or more, preferably 20% or less, more preferably 10% or less, and still more preferably 5% or less. The surface adhering substance can suppress the oxidation reaction of the non-aqueous electrolyte solution on the surface of the positive electrode active material, and can improve the battery life. However, when the amount of the adhering quantity is too small, the effect is not sufficiently exhibited. If the amount is too large, the resistance may increase in order to inhibit the entry and exit of lithium ions.

(Manufacture of electrodes)
As the binder for binding the active material, any material can be used as long as it is a material that is stable with respect to the solvent and the electrolytic solution used during electrode production. For example, fluorine resins such as polyvinylidene fluoride and polytetrafluoroethylene, polyolefins such as polyethylene and polypropylene, polymers having unsaturated bonds such as styrene / butadiene rubber, isoprene rubber and butadiene rubber, ethylene-acrylic acid copolymers, An acrylic acid polymer such as an ethylene-methacrylic acid copolymer may be used.

The electrode may contain a thickener, a conductive material, a filler and the like in order to increase mechanical strength and electrical conductivity.
Examples of the thickener include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, and casein.
Examples of the conductive material include metal materials such as copper and nickel, and carbon materials such as graphite and carbon black.

The electrode may be manufactured by a conventional method. For example, it can be formed by adding a binder, a thickener, a conductive material, a solvent or the like to a negative electrode or a positive electrode active material to form a slurry, applying the slurry to a current collector, drying it, and then pressing it.
In addition, a material obtained by adding a binder or a conductive material to an active material is roll-formed as it is to form a sheet electrode, a pellet electrode is formed by compression molding, and an electrode is formed on the current collector by techniques such as vapor deposition, sputtering, or plating. A thin film of material can also be formed.

When graphite is used for the negative electrode active material, the density of the negative electrode active material layer after drying and pressing is preferably 1.45 g / cm ³ or more, more preferably 1.55 g / cm ³ or more, and even more preferably 1.60 g. / Cm ³ or more, particularly preferably 1.65 g / cm ³ or more.

The density after drying and pressing of the positive electrode active material layer is preferably 2.0 g / cm ³ or more, more preferably 2.5 g / cm ³ or more, and further preferably 3.0 g / cm ³ or more.

Various types of current collectors can be used, but metals and alloys are usually used. Examples of the current collector for the negative electrode include copper, nickel, and stainless steel, and copper is preferred. Examples of the positive electrode current collector include metals such as aluminum, titanium, and tantalum, and alloys thereof, and aluminum or an alloy thereof is preferable.
Examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, metal thin film, expanded metal, punch metal, and foam metal in the case of a metal material. A thin film, a carbon cylinder, etc. are mentioned. Of these, metal thin films are preferred. In addition, you may form a thin film suitably in mesh shape.
The thickness of the current collector is usually 1 μm or more, preferably 5 μm or more, and usually 100 μm or less, preferably 50 μm or less, from the viewpoint of securing battery capacity and handling properties.

The ratio of the thickness of the current collector to the negative electrode active material layer is not particularly limited, but the value of “(the thickness of the negative electrode active material layer on one side immediately before the nonaqueous electrolyte injection) / (thickness of the current collector)” However, 150 or less is preferable, 20 or less is more preferable, 10 or less is particularly preferable, 0.1 or more is preferable, 0.4 or more is more preferable, and 1 or more is particularly preferable. When the ratio of the thickness of the current collector to the negative electrode active material layer is in the above range, battery capacity can be secured and heat generation of the current collector during high current density charge / discharge can be suppressed.
The ratio of the thickness of the current collector to the positive electrode active material layer is not particularly limited, but the value of (thickness of the positive electrode active material layer on one side immediately before electrolyte injection) / (thickness of the current collector) is 20 The lower limit is preferably 15 or less, most preferably 10 or less, and the lower limit is preferably 0.5 or more, more preferably 0.8 or more, and most preferably 1 or more. Above this range, the current collector may generate heat due to Joule heat during high current density charge / discharge. Within the above range, heat generation of the current collector during high current density charge / discharge can be suppressed, and battery capacity can be secured.

The thickness of the negative electrode plate is designed according to the positive electrode plate to be used, and is not particularly limited. However, the thickness of the composite layer obtained by subtracting the metal foil thickness of the core material is usually 15 μm or more, preferably 20 μm. Above, more preferably 30 μm or more, and usually 300 μm or less, preferably 280 μm or less, more preferably 250 μm or less.
The thickness of the positive electrode plate is not particularly limited, but from the viewpoint of high capacity and high output, the thickness of the composite layer obtained by subtracting the metal foil thickness of the core material is preferably as a lower limit with respect to one side of the current collector. Is 10 μm or more, more preferably 20 μm or more, and the upper limit is preferably 500 μm or less, more preferably 450 μm or less.

(Separator, exterior body)
A porous film (separator) is interposed between the positive electrode and the negative electrode to prevent a short circuit. In this case, the electrolytic solution is used by impregnating the porous membrane. The material and shape of the porous film are not particularly limited as long as it is stable to the electrolytic solution and excellent in liquid retention, and a porous sheet or nonwoven fabric made of a polyolefin such as polyethylene or polypropylene is preferable.

The thickness of the separator is arbitrary, but is usually 1 μm or more, preferably 5 μm or more, and 8
More preferably, it is 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less. Within the above range, insulation and mechanical strength can be secured, while battery performance such as rate characteristics and energy density can be secured.

  Furthermore, when using a porous material such as a porous sheet or nonwoven fabric as the separator, the porosity of the separator is arbitrary, but is usually 20% or more, preferably 35% or more, more preferably 45% or more, Further, it is usually 90% or less, preferably 85% or less, and more preferably 75% or less. When the porosity is in the above range, insulation and mechanical strength can be secured, while film resistance can be suppressed and good rate characteristics can be obtained.

  Moreover, although the average pore diameter of a separator is also arbitrary, it is 0.5 micrometer or less normally, 0.2 micrometer or less is preferable, and it is 0.05 micrometer or more normally. If the average pore diameter exceeds the above range, a short circuit tends to occur. When the average pore diameter is in the above range, the film resistance can be suppressed and good rate characteristics can be obtained while preventing a short circuit. On the other hand, as inorganic materials, 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. Used.

The material of the battery casing used in the battery according to the present invention is also arbitrary, and nickel-plated iron, stainless steel, aluminum or an alloy thereof, nickel, titanium, a laminate film, or the like is used.
The operating voltage of the above-described non-aqueous electrolyte secondary battery of the present invention is usually in the range of 2V to 5V.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.
In addition, each evaluation method of the battery obtained by the following Example and the comparative example is shown below.

[Capacity evaluation]
After charging the sheet-like non-aqueous electrolyte battery at a constant current of up to 4.1 V at a current corresponding to 0.2 C at 25 ° C. in a state of being pressed between glass plates in order to enhance the adhesion between the electrodes. After discharging to 3 V at a constant current of 0.2 C, and further to constant current-constant voltage charging (hereinafter referred to as “CCCV charging” as appropriate) (0.05 C cut) to 4.33 V at a current equivalent to 0.2 C The battery was stabilized by discharging to 3 V at 0.2 C. Next, after CCCV charge (0.05 C cut) to 4.33 V at 0.2 C, the battery was discharged again to 3 V at 0.2 C, and the initial discharge capacity was determined.
Here, 1C represents a current value for discharging the reference capacity of the battery in one hour, and for example, 0.2C represents a current value of 1/5 thereof.

[Evaluation of high-temperature storage characteristics]
After the initial capacity evaluation, the non-aqueous electrolyte battery was CCCV charged (0.05 C cut) at 25 ° C. to 4.33 V at 0.2 C, and then stored at 85 ° C. for 24 hours at a high temperature. Went. After sufficiently cooling the battery, the volume was measured by immersion in an ethanol bath, and the amount of generated gas was determined from the volume change before and after storage. Next, discharge at 25 ° C. to 3 V at 0.2 C, measure the remaining capacity after evaluating the high-temperature storage characteristics, determine the ratio of the remaining capacity to the initial discharge capacity, this is the remaining capacity (%) after high-temperature storage did. Again, charge CCCV (0.05C cut) to 4.33V at 0.2C, discharge to 3V at 0.2C, measure 0.2C discharge capacity after evaluating high-temperature storage characteristics, and store against initial discharge capacity The ratio of the 0.2C discharge capacity after the test was determined, and this was defined as the recovery capacity (%) after high-temperature storage.

Example 1
[Manufacture of negative electrode]
100 parts by weight of graphite powder as the negative electrode active material, 1 part by weight of aqueous dispersion of sodium carboxymethyl cellulose (concentration of 1% by weight of sodium carboxymethyl cellulose) as the thickener and binder, respectively, and aqueous dispersion of styrene-butadiene rubber 1 part by mass (concentration of styrene-butadiene rubber 50% by mass) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a 12 μm thick copper foil, dried, and then pressed to obtain a negative electrode.

[Production of positive electrode]
97% by mass of lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, 1.5% by mass of acetylene black as a conductive material, and 1.5% by mass of polyvinylidene fluoride (PVdF) as a binder, N-methylpyrrolidone In a solvent, the mixture was slurried by mixing with a disperser. This was uniformly applied to both sides of a 21 μm thick aluminum foil, dried, and then pressed to obtain a positive electrode.

[Production of non-aqueous electrolyte]
Under a dry argon atmosphere, a mixture of ethylene carbonate and dimethyl carbonate (volume ratio 30:70) was mixed so that 2% by mass of vinylene carbonate and 0.3% by mass of the compound A20 were contained in the non-aqueous electrolyte. Then, sufficiently dried LiPF ₆ was dissolved at a rate of 1.0 mol / liter to obtain an electrolytic solution.

[Manufacture of non-aqueous electrolyte secondary batteries]
The positive electrode, the negative electrode, and a polyethylene separator (thickness 25 μm) were laminated in the order of the negative electrode, the separator, the positive electrode, the separator, and the negative electrode to produce a battery element. This battery element was inserted into a bag made of a laminate film in which both surfaces of aluminum (thickness: 40 μm) were coated with a resin layer while projecting positive and negative terminals, and then the non-aqueous electrolyte was poured into the bag. Then, vacuum sealing was performed to produce a sheet-like non-aqueous electrolyte battery, and the high-temperature storage characteristics were evaluated. The evaluation results are shown in Table 1.

(Example 2)
In the electrolytic solution of Example 1, a sheet-like non-aqueous electrolyte battery was produced in the same manner as in Example 1 except that the amount of A20 added was 0.5% by mass, and the high-temperature storage characteristics were evaluated. . The evaluation results are shown in Table 1.

(Comparative Example 1)
2% by mass of vinylene carbonate was mixed as a content in the non-aqueous electrolyte with a mixture of ethylene carbonate and dimethyl carbonate (volume ratio 3: 7). Subsequently, a sheet-like non-aqueous electrolyte battery was prepared in the same manner as in Example 1 except that an electrolyte prepared by dissolving LiPF ₆ sufficiently dried to a ratio of 1.0 mol / liter was used. The high-temperature storage characteristics were evaluated. The evaluation results are shown in Table 1.

  As is apparent from Table 1, the battery according to the present invention has a small amount of gas generated after high-temperature storage and is excellent in remaining capacity and recovery capacity after high-temperature storage.

  Since the nonaqueous electrolyte battery using the nonaqueous electrolyte of the present invention has a high capacity and excellent high temperature storage characteristics, it can be used for various known applications. Specific examples include notebook computers, pen input computers, mobile computers, electronic book players, mobile phones, mobile faxes, mobile copy, mobile printers, headphone stereos, video movies, LCD TVs, handy cleaners, portable CDs, minidiscs, etc. , Walkie Talkie, Electronic Notebook, Calculator, Memory Card, Portable Tape Recorder, Radio, Backup Power Supply, Motor, Automobile, Motorcycle, Motorbike, Bicycle, Lighting Equipment, Toy, Game Equipment, Clock, Electric Tool, Strobe, Camera, Load A power source for leveling, a natural energy storage power source, and the like can be given.

Claims (4)

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

(In General Formula (1), R ₁ and R ₂ each independently represent a hydrogen atom, a fluorine atom, or a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a fluorine atom, and X is carbon. Represents a divalent linking group of formula 1-12.   The non-aqueous electrolyte solution according to claim 1, wherein a ratio of the compound represented by the general formula (1) in the non-aqueous electrolyte solution is 0.001 to 10% by mass.   Furthermore, it contains at least one selected from the group consisting of a cyclic carbonate compound having a carbon-carbon unsaturated bond, a cyclic carbonate compound having a fluorine atom, a monofluorophosphate and a difluorophosphate. The non-aqueous electrolyte described.   4. A non-aqueous electrolyte battery comprising a negative electrode and a positive electrode capable of inserting and extracting lithium ions, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution is a non-aqueous electrolyte solution according to claim 1. A non-aqueous electrolyte battery characterized by the above.