JP6263910B2 - Non-aqueous electrolyte and non-aqueous electrolyte battery using the same - Google Patents

Description

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

With the rapid progress of portable electronic devices such as mobile phones and notebook personal computers, there is an increasing demand for higher capacities for batteries used for the main power source and backup power source, such as nickel cadmium batteries and nickel Non-aqueous electrolyte batteries such as lithium ion secondary batteries having higher energy density than hydrogen batteries have attracted attention.
As an electrolytic solution of the lithium ion secondary battery, an electrolyte such as LiPF ₆ , LiBF ₄ , LiN (CF ₃ SO ₂ ) ₂ , LiCF ₃ (CF ₂ ) ₃ SO ₃ is used as a high dielectric constant such as ethylene carbonate or propylene carbonate. A typical example is a non-aqueous electrolyte solution dissolved in a mixed solvent of a solvent and a low-viscosity solvent such as dimethyl carbonate, diethyl carbonate, or ethyl methyl carbonate.

  In addition, as a negative electrode active material of a lithium ion secondary battery, a carbonaceous material capable of occluding and releasing lithium ions is mainly used, and natural graphite, artificial graphite, amorphous carbon, etc. are listed as representative examples. It is done. Furthermore, metal or alloy negative electrodes using silicon, tin or the like for increasing the capacity are also known. As the positive electrode active material, a transition metal composite oxide capable of mainly inserting and extracting lithium ions is used, and representative examples of the transition metal include cobalt, nickel, manganese, iron and the like.

Such a lithium ion secondary battery uses a highly active positive electrode and negative electrode, and it is known that the charge / discharge capacity decreases due to a side reaction between the electrode and the electrolyte, improving battery characteristics. Therefore, various studies have been made on non-aqueous solvents and electrolytes.
Patent Document 1 attempts to improve battery storage characteristics by adding a tricarbimide compound such as triallyl cyanurate or triallyl isocyanurate to a nonaqueous electrolytic solution.

  In Patent Document 2, cell swelling due to gas generation is suppressed by using an electrolyte containing a high-boiling solvent typified by ethylene carbonate and a halogenated cyclic carbonate compound, and the discharge characteristics and low-temperature cycle characteristics of the battery are improved. An attempt has been made.

JP-A-7-192757 JP-A-2005-108440

  However, the demand for improving the characteristics of lithium non-aqueous electrolyte secondary batteries in recent years is increasing, and all the performances such as high-temperature storage characteristics, energy density, output characteristics, life, high-speed charge / discharge characteristics, and low-temperature characteristics Although it is required to have a high level, it has not yet been achieved. The durability performance including high temperature storage characteristics and the performance such as capacity, resistance, and output characteristics are in a trade-off relationship.

The present invention has been made in view of the above-described problems. That is, with respect to a lithium non-aqueous electrolyte secondary battery, an object is to provide a battery having a good balance of overall performance with respect to performance such as durability and capacity, resistance, and output characteristics.

Currently, a carbon material is generally used as an electrode for the negative electrode of a lithium ion secondary battery. The potential at which charging / discharging of the carbon material proceeds is approximately 0.07 to 0.23 V, and there is no organic compound that exists thermodynamically stably at such potential. Therefore, a carbonate compound generally used as an electrolytic solution for a lithium ion secondary battery undergoes reductive decomposition, and LiF, Li ₂ CO ₃ , Li ₂ O, LiOH, and ethylene oxide (—CH ₂ —CH ₂ ) are formed on the carbon surface. It is known that a non-conductive film having a -O-) unit as a main component is formed, whereby reductive decomposition of the solvent is suppressed and charge / discharge proceeds stably. Such a non-conductive film is called SEI (Solid Electrolyte Interface).

Therefore, by strengthening SEI, it is possible to improve battery cycle characteristics, and to suppress battery deterioration such as self-discharge due to the decay of SEI during storage at high temperature after charging or cell swelling due to gas generated by solvent decomposition reaction. .
In Patent Document 1, the negative electrode SEI is strengthened by adding a tricarbimide compound such as triallyl cyanurate or triallyl isocyanurate to the nonaqueous electrolytic solution, and the storage characteristics are improved. In general, triallyl cyanurate and triallyl isocyanurate are also used as a crosslinking agent for resins. From this, it is thought that SEI is strengthened by reacting with the decomposition product of the solvent produced | generated on the negative electrode by adding them in a battery, and expressing a crosslinking effect. However, the stability of the SEI film was not yet satisfactory with these compounds alone.

In Patent Document 2, cell swelling is suppressed and battery characteristics are improved by combining a high-boiling solvent typified by ethylene carbonate and a halogenated carbonate. However, satisfactory results were not obtained in improving battery characteristics.
In order to solve the above-mentioned problems, in the present invention, a compound containing the structure represented by the general formula (A) and a halogenated cyclic carbonate compound are contained in a non-aqueous electrolyte solution. Thereby, decomposition of the compound represented by the general formula (A) with at least one compound selected from the group consisting of a halogenated cyclic carbonate compound, a nitrile compound, an isocyanate compound, a difluorophosphate and a monofluorosulfonate By reacting together, the crosslinking effect is further promoted and the strength of SEI is improved. As a result, the present inventors have found that battery characteristics such as cycle characteristics and high-temperature storage characteristics are improved and the above problems can be solved.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have found that a compound containing a structure represented by the formula (A), a halogenated cyclic carbonate compound, a nitrile compound, an isocyanate compound, difluorophosphoric acid The inventors have found that the above problem can be solved by containing at least one compound selected from the group consisting of a salt and a monofluorosulfonate, and have completed the present invention described later.

The gist of the present invention is as follows.
A non-aqueous electrolyte solution for a non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of occluding and releasing metal ions, the non-aqueous electrolyte solution being represented by the following general formula (A) together with an electrolyte and a non-aqueous solvent A non-aqueous system comprising a compound containing a structure, and at least one compound selected from the group consisting of a halogenated cyclic carbonate compound, a nitrile compound, an isocyanate compound, a difluorophosphate, and a monofluorosulfonate Electrolytic solution.

(In formula (A), R _a to R _c are organic groups optionally having a substituent having 1 to 20 carbon atoms. R _b and R _c are bonded to each other to form a ring. _a and R _b , R _a and R _c are not bonded.)
The non-aqueous electrolyte solution whose compound containing the structure represented by the said general formula (A) is a compound represented by the following general formula (B).

(In Formula (B), R _{1 to} R ₃ may be the same as or different from each other, and are organic groups that may have a substituent having 1 to 20 carbon atoms.)
A nonaqueous electrolytic solution in which at least one of R _{1 to} R ₃ is an allyl group in the general formula (B).
A nonaqueous electrolytic solution in which the halogenated cyclic carbonate compound is a fluorinated cyclic carbonate.

A nonaqueous electrolytic solution in which the fluorinated cyclic carbonate is at least one compound selected from the group consisting of monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, and 4,5-difluoroethylene carbonate.
The non-aqueous electrolyte solution whose addition amount of the said compound (A) is 0.01 mass% or more and 10.0 mass% or less with respect to the whole quantity of a non-aqueous electrolyte solution.

The non-aqueous electrolyte solution in which the addition amount of the halogenated cyclic carbonate compound is 0.01 vol% or more and 50.0 vol% or less with respect to the total amount of the non-aqueous electrolyte solution.
The non-aqueous electrolyte is selected from the group consisting of a cyclic carbonate having a carbon-carbon unsaturated bond, an acid anhydride compound, a compound having an isocyanuric acid skeleton, a vinyl sulfonate compound, and an aromatic compound having 12 or less carbon atoms. A non-aqueous electrolyte containing at least one compound.

A non-aqueous electrolyte secondary battery comprising a positive electrode capable of inserting and extracting lithium ions, a negative electrode capable of inserting and extracting lithium ions, and a non-aqueous electrolyte solution.
The negative electrode active material of a negative electrode capable of inserting and extracting lithium ions is a non-aqueous electrolyte battery having carbon as a constituent element.
The negative electrode active material of the negative electrode capable of inserting and extracting lithium ions is a non-aqueous electrolyte battery having silicon (Si) or tin (Sn) as a constituent element.

ADVANTAGE OF THE INVENTION According to this invention, regarding a lithium non-aqueous electrolyte secondary battery, a battery with a good balance of overall performance can be provided with respect to performance such as durability, capacity, resistance, and output characteristics.
Action and principle that the non-aqueous electrolyte secondary battery manufactured using the non-aqueous electrolyte of the present invention and the non-aqueous electrolyte secondary battery of the present invention become a secondary battery with a good balance of overall performance. Is not clear, but is considered as follows. However, the present invention is not limited to the operations and principles described below.

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.
In addition, when simply described as ppm here, it indicates “mass ppm”.

1. Non-aqueous electrolyte 1-1. Nonaqueous Electrolytic Solution of the Present Invention The nonaqueous electrolytic solution of the present invention includes a compound having a structure represented by the general formula (A), a halogenated cyclic carbonate compound, a nitrile compound, an isocyanate compound, a difluorophosphate, and a monovalent compound. It contains at least one compound selected from the group consisting of fluorosulfonates.
1-1-1. Compound having structure represented by general formula (A)

In formula (A), R _a to R _c are organic groups optionally having a substituent having 1 to 20 carbon atoms. R _b and R _c are bonded to each other to form a ring. R _a and R _b , R _a and R _c are not bonded.
Here, the organic group represents a functional group composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms and halogen atoms. Specific examples include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, a nitrile group, an isocyanato group, an ether group, a carbonate group, and a carbonyl group.

Specific examples of the substituent include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, alkoxy groups, nitrile groups, isocyanato groups, ether groups, carbonate groups, carbonyl groups, carboxyl groups which may be substituted with halogen atoms. Group, sulfonyl group, phosphoryl group and the like.
The _Ra carbon atom is preferably an alkenyl group, and specific examples include a vinyl group, an allyl group, and a 1-propenyl group, and an allyl group is preferable.
Moreover, it is preferable that the compound which has a structure represented by the said formula (A) is represented by the following general formula (B).

In formula (B), R1 to R3 may be the same as or different from each other, and are organic groups that may have a substituent having 1 to 20 carbon atoms.
Here, the organic group represents a functional group composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms and halogen atoms. Specific examples include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, a nitrile group, an isocyanato group, an ether group, a carbonate group, and a carbonyl group.

Specific examples of the substituent include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, alkoxy groups, nitrile groups, isocyanato groups, ether groups, carbonate groups, carbonyl groups, carboxyl groups which may be substituted with halogen atoms. Group, sulfonyl group, phosphoryl group and the like.
Specific examples of the alkyl group include, for example, linear or branched chain such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, and tert-butyl group. Examples thereof include cyclic alkyl groups such as an alkyl group, a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group.

Specific examples of the alkenyl group include a vinyl group, an allyl group, and a 1-propenyl group, and an allyl group is preferable.
Specific examples of the alkynyl group include ethynyl group, propargyl group, 1-propynyl group and the like.
Specific examples of the aryl group include a phenyl group, a tolyl group, a benzyl group, and a phenethyl group.

Specific examples of the organic group that may have a substituent include an acrylic group, a methacryl group, an acrylic group via an alkyl group, a methacryl group, an epoxy group, a glycidyl group, a carbonyl group, a cyanoalkyl group, and an isocyanatoalkyl group. And a vinylsulfonyl group.
Among them, preferred are methyl group, ethyl group, i-propyl group, tert-butyl group, cyclohexyl group, vinyl group, allyl group, ethynyl group, propargyl group, phenyl group, tolyl group, benzyl group, acrylic group, methacryl group. , An acrylic group via an alkyl group, a methacryl group, a glycidyl group, a carbonyl group, a cyanoalkyl group, an isocyanatoalkyl group, and a vinylsulfonyl group.

  More preferably, acrylic via i-propyl, tert-butyl, cyclohexyl, vinyl, allyl, ethynyl, propargyl, phenyl, tolyl, benzyl, acrylic, methacrylic, alkyl groups. Group, methacryl group, glycidyl group, carbonyl group, cyanoalkyl group, isocyanatoalkyl group and vinylsulfonyl group.

Particularly preferred are a cyclohexyl group, a vinyl group, an allyl group, a propargyl group, an acrylic group, a methacryl group, an acrylic group via an alkyl group, a methacryl group, a carbonyl group, an isocyanatoalkyl group, and a vinylsulfonyl group.
Most preferably, a vinyl group, an allyl group, an acrylic group via an alkyl group, a methacryl group, an isocyanatoalkyl group, and a vinylsulfonyl group are exemplified.
Specific examples of the compound include, for example,

  Among them, preferably

  More preferably,

Particularly preferably,

Most preferably,

Is mentioned.
1-1-2. Halogenated cyclic carbonate compound The halogenated cyclic carbonate compound may be any cyclic carbonate having any halogen atom, but is preferably a fluorinated cyclic carbonate.
Examples of the fluorinated cyclic carbonate include a fluorinated product of a cyclic carbonate having an alkylene group having 2 to 6 carbon atoms, and derivatives thereof, and examples thereof include a fluorinated product of ethylene carbonate and derivatives thereof. Examples of the derivatives of fluorinated ethylene carbonate include fluorinated ethylene carbonate substituted with an alkyl group (for example, an alkyl group having 1 to 4 carbon atoms). Of these, ethylene carbonate having 1 to 8 fluorine atoms and derivatives thereof are preferable.

In particular,
Monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4-fluoro-4-methylethylene carbonate, 4,5-difluoro-4-methylethylene carbonate, 4-fluoro-5-methyl Ethylene carbonate, 4,4-difluoro-5-methylethylene carbonate, 4- (fluoromethyl) -ethylene carbonate, 4- (difluoromethyl) -ethylene carbonate, 4- (trifluoromethyl) -ethylene carbonate, 4- (fluoro Methyl) -4-fluoroethylene carbonate, 4- (fluoromethyl) -5-fluoroethylene carbonate, 4-fluoro-4,5-dimethylethylene carbonate, 4,5-difluoro-4,5-dimethylethylene Boneto, 4,4-difluoro-5,5-dimethylethylene carbonate.

Among them, at least one selected from the group consisting of monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, and 4,5-difluoroethylene carbonate provides high ion conductivity and suitably forms an interface protective film. And more preferable.
A fluorinated cyclic carbonate may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  The compound having the structure represented by the formula (A) may be used alone or in combination of two or more in any combination and ratio. The compounding amount of the compound having the structure represented by the formula (A) with respect to the entire non-aqueous electrolyte of the present invention is not limited, and is arbitrary as long as the effects of the present invention are not significantly impaired. The non-aqueous electrolyte of the present invention Is usually 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass. It is contained at a concentration of not more than mass%.

  Moreover, the said halogenated cyclic carbonate compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. The blending amount of the halogenated cyclic carbonate compound with respect to the entire non-aqueous electrolyte solution of the present invention is not limited, and is arbitrary as long as the effects of the present invention are not significantly impaired. 01% by volume or more, preferably 0.05% by volume or more, more preferably 0.1% by volume or more, and usually 50% by volume or less, preferably 40% by volume or less, more preferably 30% by volume or less, particularly preferably It is contained at a concentration of 25% by volume or less, most preferably 20% by volume or less.

1-1-3. Nitrile Compound The nitrile compound is not particularly limited as long as it is a compound having a nitrile group in the molecule.
Specific examples of nitrile compounds include, for example,
Acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile, 2-methylbutyronitrile, trimethylacetonitrile, hexanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, acrylonitrile, methacrylonitrile , Crotononitrile, 3-methylcrotononitrile, 2-methyl-2-butenenitryl, 2-pentenenitrile, 2-methyl-2-pentenenitrile, 3-methyl-2-pentenenitrile, 2-hexenenitrile, Fluoroacetonitrile, difluoroacetonitrile, trifluoroacetonitrile, 2-fluoropropionitrile, 3-fluoropropionitrile, 2,2-difluoropropionitrile, 2,3-diph Oropropionitrile, 3,3-difluoropropionitrile, 2,2,3-trifluoropropionitrile, 3,3,3-trifluoropropionitrile, 3,3′-oxydipropionitrile, 3,3 ′ A compound having one nitrile group such as thiodipropionitrile, 1,2,3-propanetricarbonitrile, 1,3,5-pentanetricarbonitrile, pentafluoropropionitrile;

Malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimonitrile, suberonitrile, azeronitrile, sebacononitrile, undecandinitrile, dodecandinitrile, methylmalononitrile, ethylmalononitrile, isopropylmalononitrile, tert-butylmalononitrile, methylsuccinonitrile 2,2-dimethylsuccinonitrile, 2,3-dimethylsuccinonitrile, 2,3,3-trimethylsuccinonitrile, 2,2,3,3-tetramethylsuccinonitrile, 2,3-diethyl- 2,3-dimethylsuccinonitrile, 2,2-diethyl-3,3-dimethylsuccinonitrile, bicyclohexyl-1,1-dicarbonitrile, bicyclohexyl-2,2-dicarbonitrile, bicyclohexyl- , 3-dicarbonitrile, 2,5-dimethyl-2,5-hexanedicarbonitrile, 2,3-diisobutyl-2,3-dimethylsuccinonitrile, 2,2-diisobutyl-3,3-dimethylsuccino Nitrile, 2-methylglutaronitrile, 2,3-dimethylglutaronitrile, 2,4-dimethylglutaronitrile, 2,2,3,3-tetramethylglutaronitrile, 2,2,4,4-tetra Methylglutaronitrile, 2,2,3,4-tetramethylglutaronitrile, 2,3,3,4-tetramethylglutaronitrile, maleonitrile, fumaronitrile, 1,4-dicyanopentane, 2,6-dicyanoheptane 2,7-dicyanooctane, 2,8-dicyanononane, 1,6-dicyanodecane, 1,2-didiananobenzene, 1,3-disi Nobenzene, 1,4-dicyanobenzene, 3,3 ′-(ethylenedioxy) dipropionitrile, 3,3 ′-(ethylenedithio) dipropionitrile, 3,9-bis (2-cyanoethyl) -2,4 , 8,10-tetraoxaspiro [5,5] undecane and other compounds having two nitrile groups;
Compounds having three cyano groups such as cyclohexanetricarbonitrile, triscyanoethylamine, triscyanoethoxypropane, tricyanoethylene, pentanetricarbonitrile, propanetricarbonitrile, heptanetricarbonitrile;
Etc.

  Of these, lauronitrile, crotononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeonitrile, suberonitrile, azeronitrile, sebacononitrile, undecandinitrile, dodecandinitrile, fumaronitrile, 3,9-bis (2-cyanoethyl)- 2,4,8,10-Tetraoxaspiro [5,5] undecane is preferred from the viewpoint of improving storage characteristics. In addition, succinonitrile, glutaronitrile, adiponitrile, pimonitrile, suberonitrile, azeronitrile, sebacononitrile, undecandinitrile, dodecandinitrile, fumaronitrile, 3,9-bis (2-cyanoethyl) -2,4,8,10-tetra Particularly preferred are dinitrile compounds such as oxaspiro [5,5] undecane.

  A nitrile compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. There is no limitation on the amount of the nitrile compound added to the whole non-aqueous electrolyte solution of the present invention, and it is optional as long as the effect of the present invention is not significantly impaired, but usually 0.001% by mass with respect to the non-aqueous electrolyte solution of the present invention. Above, preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less. When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-1-4. Isocyanate compound The type of the isocyanate compound is not particularly limited as long as it is a compound having an isocyanate group in the molecule.
Specific examples of the isocyanate compound include, for example,
Monoisocyanates such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, butyl isocyanate, tertiary butyl isocyanate, pentyl isocyanate hexyl isocyanate, cyclohexyl isocyanate, vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, propynyl isocyanate, phenyl isocyanate, fluorophenyl isocyanate Compound;

Monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-diisocyanate Natopropane, 1,4-diisocyanato-2-butene, 1,4-diisocyanato-2-fluorobutane, 1,4-diisocyanato-2,3-difluorobutane, 1,5-diisocyanato-2-pentene, 1,5 -Diisocyanato-2-methylpentane, 1,6-diisocyanato-2-hexene, 1,6-diisocyanato-3-hexene, 1,6 Diisocyanato-3-fluorohexane, 1,6-diisocyanato-3,4-difluorohexane, toluene diisocyanate, xylene diisocyanate, tolylene diisocyanate, 1,2-bis (isocyanatomethyl) cyclohexane, 1,3-bis (isocyanato) Methyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-1,1 ′ -Diisocyanate, dicyclohexylmethane-2,2'-diisocyanate, dicyclohexylmethane-3,3'-diisocyanate, dicyclohexylmethane-
4,4′-diisocyanate, bicyclo [2.2.1] heptane-2,5-diylbis (
Methyl isocyanate), bicyclo [2.2.1] heptane-2,6-diylbis (methyl isocyanate), isophorone diisocyanate, carbonyl diisocyanate, 1,4
-Diisocyanatobutane-1,4-dione, 1,5-diisocyanatopentane-1,5-dione, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylenedi Diisocyanate compounds such as isocyanate;
Etc.

Among these, monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 1, 3-bis (isocyanatomethyl) cyclohexane, dicyclohexylmethane-4,4′-diisocyanate, bicyclo [2.2.1]
Heptane-2,5-diylbis (methylisocyanate), bicyclo [2.2.1] heptane-2,6-diylbis (methylisocyanate), isophorone diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2 Diisocyanate compounds such as 4,4-trimethylhexamethylene diisocyanate are preferred from the standpoint of improving storage characteristics.

  The isocyanate compound used in the present invention may be a trimer compound derived from a compound having at least two isocyanate groups in the molecule, or an aliphatic polyisocyanate obtained by adding a polyhydric alcohol thereto. For example, biuret, isocyanurate, adduct, and bifunctional type modified polyisocyanate represented by the basic structures of the following general formulas (3-1) to (3-4) can be exemplified (the following general formula (1-2) -1) to (1-2-4), R and R ′ are each independently any hydrocarbon group).

  The compound having at least two isocyanate groups in the molecule used in the present invention also includes so-called blocked isocyanate which is blocked with a blocking agent to enhance storage stability. Examples of the blocking agent include alcohols, phenols, organic amines, oximes, and lactams. Specific examples include n-butanol, phenol, tributylamine, diethylethanolamine, methyl ethyl ketoxime, and ε-caprolactam. Etc.

In order to promote a reaction based on a compound having at least two isocyanate groups in the molecule and obtain a higher effect, a metal catalyst such as dibutyltin dilaurate or the like, 1,8-diazabicyclo [5.4.0] undecene- It is also preferable to use an amine catalyst such as 7 in combination.
Furthermore, the compound which has an isocyanate group may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

There is no restriction | limiting in the compounding quantity of the compound which has an isocyanate group with respect to the whole nonaqueous electrolyte solution of this invention, Although it is arbitrary unless the effect of this invention is impaired remarkably, Usually, it is 0.8 with respect to the nonaqueous electrolyte solution of this invention. 001% by mass or more, preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less. Let
When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-1-5. Difluorophosphate The counter cation of difluorophosphate is not particularly limited, but lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR ¹¹ R ¹² R ¹³ R ¹⁴ (wherein R ^{11 to} R ¹⁴ each independently represents a hydrogen atom or an organic group having 1 to 12 carbon atoms).

Although it does not specifically limit as a C1-C12 organic group represented by R < ¹¹ > -R < ¹⁴ > of the said ammonium, For example, it is substituted by the alkyl group, the halogen atom, or the alkyl group which may be substituted by the halogen atom. 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 ^{11 to} R ¹⁴ , a hydrogen atom, an alkyl group, a cycloalkyl group, or a nitrogen atom-containing heterocyclic group is preferable.

Specific examples of difluorophosphate include
Examples include lithium difluorophosphate, sodium difluorophosphate, and potassium difluorophosphate. Lithium difluorophosphate is preferred.
A difluorophosphate may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and a ratio. Moreover, the compounding quantity of a difluorophosphate is not restrict | limited in particular, As long as the effect of this invention is not impaired remarkably, it is arbitrary.

The amount of difluorophosphate is 100% by mass in the non-aqueous electrolyte solution, preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and further preferably 0.1% by mass or more. Moreover, Preferably it is 5 mass% or less, More preferably, it is 4 mass% or less, More preferably, it is 3 mass% or less.
Within this range, the non-aqueous electrolyte battery tends to exhibit a sufficient cycle characteristics improvement effect, and the high temperature storage characteristics deteriorate, the amount of gas generated increases, and the discharge capacity maintenance ratio decreases. Easy to avoid.

1-1-6. Monofluorosulfonate salt There is no particular limitation on the counter cation of the monofluorosulfonate salt, but lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR ¹¹ R ¹² R ¹³ R ¹⁴ (wherein , R ^{11 to} R ¹⁴ each independently represents a hydrogen atom or an organic group having 1 to 12 carbon atoms).

Although it does not specifically limit as a C1-C12 organic group represented by R < ¹¹ > -R < ¹⁴ > of the said ammonium, For example, it is substituted by the alkyl group, the halogen atom, or the alkyl group which may be substituted by the halogen atom. 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 ^{11 to} R ¹⁴ , a hydrogen atom, an alkyl group, a cycloalkyl group, or a nitrogen atom-containing heterocyclic group is preferable.

As specific examples of monofluorosulfonate,
Examples thereof include lithium monofluorosulfonate, sodium monofluorosulfonate, potassium monofluorosulfonate, rubidium monofluorosulfonate, cesium monofluorosulfonate, and lithium monofluorosulfonate is preferable.
Monofluorosulfonate may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and a ratio. Moreover, the compounding quantity of a difluorophosphate is not restrict | limited in particular, As long as the effect of this invention is not impaired remarkably, it is arbitrary.

The amount of monofluorosulfonate is 100% by mass in the non-aqueous electrolyte solution, preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and further preferably 0.1% by mass or more. Moreover, it is preferably 5% by mass or less, more preferably 4% by mass or less, and further preferably 3% by mass or less.
Within this range, the non-aqueous electrolyte battery tends to exhibit a sufficient cycle characteristics improvement effect, and the high temperature storage characteristics deteriorate, the amount of gas generated increases, and the discharge capacity maintenance ratio decreases. Easy to avoid.

1-2. Electrolyte <Lithium salt>
As the electrolyte, a lithium salt is usually used. The lithium salt is not particularly limited as long as it is known to be used for this purpose, and any lithium salt can be used. Specific examples include the following.

For _{example, LiPF 6, LiBF 4, LiClO} 4, LiAlF 4, LiSbF 6, inorganic lithium salts LiTaF 6, LiWF ₇ and the like;
Lithium tungstates such as LiWOF ₅ ;
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 them, LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiTaF ₆ , FSO ₃ Li, CF ₃ SO ₃ Li, 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 cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropane disulfonylimide, LiC (FSO ₂ ) ₃ , LiC (CF _{3 SO 2) 3, LiC (C} 2 F 5 SO 2) 3, lithium Bisuo Kisara oxalatoborate, lithium difluoro oxalatoborate, lithium tetrafluoro-oxa Lato phosphate, lithium difluoro bis oxa Lato _phosphate, LiBF ₃ CF _3, LiBF ₃ C ₂ F ₅ , LiPF ₃ (CF ₃ ) ₃ , LiPF ₃ (C ₂ F ₅ ) _{3 and the} like are particularly preferable because they have an effect of improving output characteristics, high-rate charge / discharge characteristics, high-temperature storage characteristics, cycle characteristics, and the like.

These lithium salts may be used alone or in combination of two or more. A preferable example in the case of using two or more types in combination is a combination of LiPF ₆ and LiBF ₄ or LiPF ₆ and FSO ₃ Li, which has an effect of improving load characteristics and cycle characteristics.
In this case, the concentration of LiBF ₄ or FSO ₃ Li with respect to 100% by mass of the entire non-aqueous electrolyte solution is not limited as long as it does not significantly impair the effects of the present invention. On the other hand, it is usually 0.01% by mass or more, preferably 0.1% by mass or more, and usually 30% by mass or less, preferably 20% by mass or less.

Another example is the combined use of an inorganic lithium salt and an organic lithium salt, and the combined use of both has the effect of suppressing deterioration due to high-temperature storage. As the organic lithium salt, CF ₃ SO ₃ Li, 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 cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropane disulfonylimide, LiC (FSO ₂ ) ₃ , LiC (CF ₃ SO ₂ ) ₃ , LiC (C ₂ F ₅ SO ₂ ) ₃ , Lithium bisoxalatoborate, Lithium difluorooxalatoborate, Lithium tetrafluorooxalatophosphate, Lithium difluorobisoxalatophosphate, LiBF ₃ CF ₃ , LiBF ₃ C ₂ F ₅ , LiPF ₃ (CF ₃ ) ₃ LiPF ₃ (C ₂ F ₅ ) ₃ or the like is preferable. In this case, the ratio of the organic lithium salt to 100% by mass of the whole non-aqueous electrolyte is preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and preferably 30% by mass or less. Especially preferably, it is 20 mass% or less.

The concentration of these lithium salts in the non-aqueous electrolyte solution is not particularly limited as long as the effects of the present invention are not impaired, but the electric conductivity of the electrolyte solution is in a good range, and good battery performance is ensured. Therefore, the total molar concentration of lithium in the non-aqueous electrolyte is preferably 0.3 mol / L or more, more preferably 0.4 mol / L or more, and further preferably 0.5 mol / L or more. Preferably it is 3 mol / L or less, More preferably, it is 2.5 mol / L or less, More preferably, it is 2.0 mol / L or less.
If the total molar concentration of lithium is too low, the electrical conductivity of the electrolyte may be insufficient. On the other hand, if the concentration is too high, the electrical conductivity may decrease due to an increase in viscosity, resulting in decreased battery performance. There is a case.

1-3. Nonaqueous solvent There is no restriction | limiting in particular about the nonaqueous solvent in this invention, It is possible to use a well-known organic solvent. Examples thereof include cyclic carbonates having no fluorine atom, chain carbonates, cyclic and chain carboxylic acid esters, ether compounds, sulfone compounds, and the like.

<Cyclic carbonate without fluorine atoms>
Examples of the cyclic carbonate having no fluorine atom include cyclic carbonates having an alkylene group having 2 to 4 carbon atoms.
Specific examples of the cyclic carbonate having an alkylene group having 2 to 4 carbon atoms and having no fluorine atom include ethylene carbonate, propylene carbonate, and butylene carbonate. Among these, ethylene carbonate and propylene carbonate are particularly preferable from the viewpoint of improving battery characteristics resulting from an improvement in the degree of lithium ion dissociation.

The cyclic carbonate which does not have a fluorine atom may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
The blending amount of the cyclic carbonate having no fluorine atom is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. However, the blending amount when one kind is used alone is 100% by volume of the nonaqueous solvent. Among them, the content is 5% by volume or more, more preferably 10% by volume or more. By setting this range, the decrease in electrical conductivity due to the decrease in the dielectric constant of the non-aqueous electrolyte is avoided, and the high current discharge characteristics, stability against the negative electrode, and cycle characteristics of the non-aqueous electrolyte battery are in a good range. And it will be easier. Moreover, 95 volume% or less, More preferably, it is 90 volume% or less, More preferably, it is 85 volume% or less. By setting it as this range, the viscosity of the non-aqueous electrolyte solution is set to an appropriate range, the decrease in ionic conductivity is suppressed, and the load characteristics of the non-aqueous electrolyte battery are easily set in a favorable range.

<Chain carbonate>
As the chain carbonate, a chain carbonate having 3 to 7 carbon atoms is preferable, and a dialkyl carbonate having 3 to 7 carbon atoms is more preferable.
Specific examples of the chain carbonate include 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. Examples include carbonate, t-butyl methyl carbonate, ethyl-n-propyl carbonate, n-butyl ethyl carbonate, isobutyl ethyl carbonate, t-butyl ethyl carbonate, and the like.

Among them, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate, and methyl n-propyl carbonate are preferable, and dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are particularly preferable. is there.
Further, chain carbonates having a fluorine atom (hereinafter sometimes referred to as “fluorinated chain carbonate”) can also be suitably 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, preferably 4 or less. When the fluorinated chain carbonate has a plurality of fluorine atoms, they may be bonded to the same carbon or may be bonded to different carbons.
Examples of the fluorinated chain carbonate include fluorinated dimethyl carbonate and derivatives thereof, fluorinated ethyl methyl carbonate and derivatives thereof, and fluorinated diethyl carbonate and derivatives thereof.

Fluorinated dimethyl carbonate and derivatives thereof include fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, bis (fluoromethyl) carbonate, bis (difluoro) methyl carbonate, bis (trifluoromethyl) carbonate, and the like. It is done.
Fluorinated ethyl methyl carbonate and derivatives thereof include 2-fluoroethyl methyl carbonate, ethyl fluoromethyl carbonate, 2,2-difluoroethyl methyl carbonate, 2-fluoroethyl fluoromethyl carbonate, ethyl difluoromethyl carbonate, 2,2,2 -Trifluoroethyl methyl carbonate, 2,2-difluoroethyl fluoromethyl carbonate, 2-fluoroethyl difluoromethyl carbonate, ethyl trifluoromethyl carbonate, etc. are mentioned.

  Fluorinated diethyl carbonate and its derivatives include ethyl- (2-fluoroethyl) carbonate, ethyl- (2,2-difluoroethyl) carbonate, bis (2-fluoroethyl) carbonate, ethyl- (2,2,2- Trifluoroethyl) carbonate, 2,2-difluoroethyl-2′-fluoroethyl carbonate, bis (2,2-difluoroethyl) carbonate, 2,2,2-trifluoroethyl-2′-fluoroethyl carbonate, 2, Examples include 2,2-trifluoroethyl-2 ′, 2′-difluoroethyl carbonate, bis (2,2,2-trifluoroethyl) carbonate, and the like.

A chain carbonate may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
The amount of the chain carbonate is preferably 5% by volume or more, more preferably 10% by volume or more, and further preferably 15% by volume or more in 100% by volume of the non-aqueous solvent. By setting the lower limit in this way, the viscosity of the non-aqueous electrolyte solution is set in an appropriate range, the decrease in ionic conductivity is suppressed, and the large current discharge characteristics of the non-aqueous electrolyte battery are easily set in a favorable range. Further, the chain carbonate is preferably 90% by volume or less, more preferably 85% by volume or less, in 100% by volume of the nonaqueous solvent. By setting the upper limit in this way, it is easy to avoid a decrease in electrical conductivity resulting from a decrease in dielectric constant of the nonaqueous electrolyte solution, and to make the large current discharge characteristics of the nonaqueous electrolyte solution battery in a favorable range.

<Cyclic carboxylic acid ester>
The cyclic carboxylic acid ester is preferably one having 3 to 12 carbon atoms.
Specific examples include gamma butyrolactone, gamma valerolactone, gamma caprolactone, epsilon caprolactone, and the like. Among these, gamma butyrolactone is particularly preferable from the viewpoint of improving battery characteristics resulting from an improvement in the degree of lithium ion dissociation.

A cyclic carboxylic acid ester may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
The amount of the cyclic carboxylic acid ester is usually 5% by volume or more, more preferably 10% by volume or more, in 100% by volume of the non-aqueous solvent. If it is this range, it will become easy to improve the electrical conductivity of a non-aqueous electrolyte solution, and to improve the large current discharge characteristic of a non-aqueous electrolyte battery. Moreover, the compounding quantity of cyclic carboxylic acid ester becomes like this. Preferably it is 50 volume% or less, More preferably, it is 40 volume% or less. By setting the upper limit in this way, the viscosity of the non-aqueous electrolyte solution is set to an appropriate range, a decrease in electrical conductivity is avoided, an increase in negative electrode resistance is suppressed, and a large current discharge of the non-aqueous electrolyte secondary battery is performed. It becomes easy to make a characteristic into a favorable range.

<Chain carboxylic acid ester>
The chain carboxylic acid ester is preferably one having 3 to 7 carbon atoms. In particular,
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, propion Acid-n-butyl, isobutyl propionate, t-butyl propionate, methyl butyrate, ethyl butyrate, butyric acid n-propyl, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, isobutyric acid n-propyl, isopropyl isobutyrate Etc.

Among them, methyl acetate, ethyl acetate, acetate-n-propyl, acetate-n-butyl, methyl propionate, ethyl propionate, propionate-n-propyl, isopropyl propionate, methyl butyrate, ethyl butyrate, etc. It is preferable from the viewpoint of improvement of ionic conductivity.
A chain carboxylic acid ester may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  The compounding amount of the chain carboxylic acid ester is usually 10% by volume or more, more preferably 15% by volume or more, in 100% by volume of the non-aqueous solvent. By setting the lower limit in this way, the electrical conductivity of the non-aqueous electrolyte solution is improved, and the large current discharge characteristics of the non-aqueous electrolyte battery are easily improved. Moreover, the compounding quantity of chain | strand-shaped carboxylic acid ester is 60 volume% or less preferably in 100 volume% of nonaqueous solvents, More preferably, it is 50 volume% or less. By setting the upper limit in this way, an increase in negative electrode resistance is suppressed, and the large current discharge characteristics and cycle characteristics of the non-aqueous electrolyte battery are easily set in a favorable range.

<Ether compound>
As the ether compound, a chain ether having 3 to 10 carbon atoms and a cyclic ether having 3 to 6 carbon atoms in which part of hydrogen may be substituted with fluorine is preferable.
As the chain ether having 3 to 10 carbon atoms,
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-tetrafluoroethyl) ether, ethyl-n-propyl ether, ethyl (3-Fluoro-n-propyl) ether, ethyl (3,3,3-trifluoro-n-propyl) ether, ethyl (2,2,3,3-teto Fluoro-n-propyl) ether, ethyl (2,2,3,3,3-pentafluoro-n-propyl) ether, 2-fluoroethyl-n-propylether, (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- (Trifluoroethyl) (3-fluoro-n-propyl) ether, (2,2,2-trifluoroethyl) (3,3,3-trifluoro-n-propyl) ether, (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 (Ro-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-pentafluoro-n-propyl) ether, di-n-butylether, dimethoxymethane, methoxyethoxymethane, methoxy (2-fluoroethoxy) Methane, methoxy (2,2,2-trifluoroethoxy) methanemethoxy (1,1,2,2-tetrafluoroethoxy) methane, diethoxymethane, ethoxy (2-fluoroethoxy) ) Methane, ethoxy (2,2,2-trifluoroethoxy) 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) methanedi (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-fluoro Ethoxy) 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, And ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether and the like. The

Examples of the cyclic ether having 3 to 6 carbon atoms include 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.
Among them, 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 improve ion dissociation. Of these, dimethoxymethane, diethoxymethane, and ethoxymethoxymethane are preferable because they have low viscosity and give high ionic conductivity.

An ether type compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
The compounding amount of the ether compound is usually in 100% by volume of the non-aqueous solvent, preferably 5% by volume or more, more preferably 10% by volume or more, further preferably 15% by volume or more, and preferably 70% by volume or less. More preferably, it is 60 volume% or less, More preferably, it is 50 volume% or less.
If it is this range, it is easy to ensure the improvement effect of the lithium ion dissociation degree of chain ether, and the improvement of the ionic conductivity derived from a viscosity fall, and when a negative electrode active material is a carbonaceous material, a chain ether with lithium ion It is easy to avoid a situation where the capacity is reduced due to co-insertion.

<Sulfone compound>
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.
As cyclic sulfone having 3 to 6 carbon atoms,
Monosulfone compounds trimethylene sulfones, tetramethylene sulfones, hexamethylene sulfones;
Examples include disulfone compounds such as trimethylene disulfones, 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 sulfolanes, sulfolane and / or sulfolane derivatives (hereinafter sometimes referred to as “sulfolanes” including sulfolane) are preferable. As the sulfolane derivative, one in which one or more hydrogen atoms bonded to the carbon atom constituting the sulfolane ring are substituted with a fluorine atom or an alkyl group is preferable.

  Among them, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,2-difluorosulfolane, 2,3-difluorosulfolane, 2,4-difluorosulfolane, 2,5-difluorosulfolane, 3,4-difluorosulfolane, 2-fluoro-3-methylsulfolane, 2-fluoro-2-methylsulfolane, 3-fluoro-3-methylsulfolane, 3-fluoro-2-methylsulfolane, 4-fluoro-3-methyl Sulfolane, 4-fluoro-2-methylsulfolane, 5-fluoro-3-methylsulfolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane, 3-fluoromethylsulfolane, 2-difluoromethylsulfolane, 3-difluoro Methyl sulfolane, 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 in terms of high ionic conductivity and high input / output characteristics.

In addition, as the chain sulfone having 2 to 6 carbon atoms,
Dimethylsulfone, ethylmethylsulfone, diethylsulfone, n-propylmethylsulfone, n-propylethylsulfone, di-n-propylsulfone, isopropylmethylsulfone, isopropylethylsulfone, diisopropylsulfone, n-butylmethylsulfone, n-butylethyl Sulfone, t-butylmethylsulfone, t-butylethylsulfone, monofluoromethylmethylsulfone, difluoromethylmethylsulfone, trifluoromethylmethylsulfone, monofluoroethylmethylsulfone, difluoroethylmethylsulfone, trifluoroethylmethylsulfone, pentafluoro Ethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, perf Oroethyl methyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di (trifluoroethyl) sulfone, perfluorodiethyl sulfone, fluoromethyl-n-propyl sulfone, difluoromethyl-n-propyl sulfone, trifluoromethyl- n-propylsulfone, fluoromethylisopropylsulfone, difluoromethylisopropylsulfone, trifluoromethylisopropylsulfone, trifluoroethyl-n-propylsulfone, trifluoroethylisopropylsulfone, pentafluoroethyl-n-propylsulfone, pentafluoroethylisopropylsulfone , Trifluoroethyl-n-butylsulfone, trifluoroethyl-t-butylsulfone, pentafluoroethyl- - butyl sulfone, pentafluoroethyl -t- butyl sulfone, and the like.

Among them, 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, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoro Ethyl sulfone, trifluoromethyl-n-propyl sulfone, trifluoromethyl isopropyl sulfone, tri Ruoroechiru -n- butyl sulfone, trifluoroethyl -t- butyl sulfone, trifluoromethyl -n- butyl sulfone, trifluoromethyl -t- butyl sulfone is high ion conductivity, preferable because the input-output characteristic is high.

A sulfone type compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
The compounding amount of the sulfone compound is usually 0.3% by volume or more, more preferably 1% by volume or more, further preferably 5% by volume or more in 100% by volume of the nonaqueous solvent, and preferably 40%. Volume% or less, More preferably, it is 35 volume% or less, More preferably, it is 30 volume% or less.

  Within this range, durability improvement effects such as cycle characteristics and storage characteristics can be easily obtained, and the viscosity of the non-aqueous electrolyte can be set to an appropriate range to avoid a decrease in electrical conductivity. When charging / discharging an aqueous electrolyte battery at a high current density, it is easy to avoid a situation in which the charge / discharge capacity retention rate decreases.

<When using a cyclic carbonate having a fluorine atom as a non-aqueous solvent>
In the present invention, when a cyclic carbonate having a fluorine atom is used as a non-aqueous solvent, one of the non-aqueous solvents exemplified above is combined with a cyclic carbonate having a fluorine atom as a non-aqueous solvent other than the cyclic carbonate having a fluorine atom. Two or more kinds may be used in combination with a cyclic carbonate having a fluorine atom.

  For example, one preferred combination of non-aqueous solvents is a combination mainly composed of a cyclic carbonate having a fluorine atom and a chain carbonate. Among them, the total of the cyclic carbonate having a fluorine atom and the chain carbonate in the non-aqueous solvent is preferably 60% by volume or more, more preferably 80% by volume or more, and further preferably 90% by volume or more, and the fluorine atom. The ratio of the cyclic carbonate having a fluorine atom to the total of the cyclic carbonate having a chain and the chain carbonate is 3% by volume or more, preferably 5% by volume or more, more preferably 10% by volume or more, and further preferably 15% by volume or more. Further, it is preferably 60% by volume or less, more preferably 50% by volume or less, still more preferably 40% by volume or less, and particularly preferably 35% 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.
For example, as a specific example of a preferable combination of a cyclic carbonate having a fluorine atom and a chain carbonate,
Monofluoroethylene carbonate and dimethyl carbonate, monofluoroethylene carbonate and diethyl carbonate, monofluoroethylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and dimethyl carbonate and diethyl carbonate, monofluoroethylene carbonate and dimethyl carbonate and ethyl methyl carbonate, monofluoro Examples thereof include ethylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.

  Among the combinations of cyclic carbonates having a fluorine atom and chain carbonates, those containing symmetric chain alkyl carbonates as chain carbonates are more preferable, and in particular, monofluoroethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, Cycle characteristics include monofluoroethylene carbonate, symmetric chain carbonates and asymmetric chain carbonates such as fluoroethylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate. And a large current discharge characteristic are preferable. Among these, the symmetric chain carbonate is preferably dimethyl carbonate, and the alkyl group of the chain carbonate preferably has 1 to 2 carbon atoms.

  A combination in which a cyclic carbonate having no fluorine atom is further added to the combination of the cyclic carbonate having a fluorine atom and the chain carbonate is also mentioned as a preferable combination. Among them, the total of the cyclic carbonate having a fluorine atom and the cyclic carbonate having no fluorine atom in the non-aqueous solvent is preferably 10% by volume or more, more preferably 15% by volume or more, and further preferably 20% by volume or more. The ratio of the cyclic carbonate having a fluorine atom to the total of the cyclic carbonate having a fluorine atom and the cyclic carbonate having no fluorine atom is 5% by volume or more, preferably 10% by volume or more, more preferably 15% by volume or more. More preferably, it is 25% by volume or more, preferably 95% by volume or less, more preferably 85% by volume or less, still more preferably 75% by volume or less, and particularly preferably 60% by volume or less.

When the cyclic carbonate having no fluorine atom is contained in this concentration range, the electrical conductivity of the electrolytic solution can be maintained while forming a stable protective film on the negative electrode.
As a specific example of a preferable combination of a cyclic carbonate having a fluorine atom and a cyclic carbonate having no fluorine atom and a chain carbonate,

Monofluoroethylene carbonate and ethylene carbonate and dimethyl carbonate, monofluoroethylene carbonate and ethylene carbonate and diethyl carbonate, monofluoroethylene carbonate and ethylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and ethylene carbonate, dimethyl carbonate and diethyl carbonate, monofluoro Ethylene carbonate, ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, diethyl carbonate, and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate Monofluoroethylene carbonate and propylene carbonate and dimethyl carbonate, monofluoroethylene carbonate and propylene carbonate and diethyl carbonate, monofluoroethylene carbonate and propylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate, dimethyl carbonate and diethyl carbonate, Monofluoroethylene carbonate, propylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, propylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate Tylmethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, ethyl methyl carbonate, monofluoroethylene Carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate and propylene carbonate Examples include diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate.

Among the combinations of cyclic carbonates having fluorine atoms and cyclic carbonates not having fluorine atoms and chain carbonates, those containing asymmetric chain alkyl carbonates as chain carbonates are more preferred,
Monofluoroethylene carbonate and ethylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and ethylene carbonate and dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate and dimethyl carbonate Ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, diethyl carbonate, ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate Ethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate And dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. Since the balance of Le characteristics and large-current discharge characteristics may preferably. Among them, the asymmetric chain carbonate is preferably ethyl methyl carbonate, and the alkyl group of the chain carbonate preferably has 1 to 2 carbon atoms.

  When ethyl methyl carbonate is contained in the non-aqueous solvent, the proportion of ethyl methyl 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 95% by volume or less, more preferably 90% by volume or less, still more preferably 85% by volume or less, and particularly preferably 80% by volume or less. The load characteristics of the battery may be improved.

  In the combination mainly composed of the cyclic carbonate having a fluorine atom and the chain carbonate, in addition to the cyclic carbonate having no fluorine atom, a cyclic carboxylic acid ester, a chain carboxylic acid ester, a cyclic ether, a chain Other solvents such as a chain ether, a sulfur-containing organic solvent, a phosphorus-containing organic solvent, and a fluorine-containing aromatic solvent may be mixed.

<When using a cyclic carbonate having a fluorine atom as an auxiliary agent>
In the present invention, when a cyclic carbonate having a fluorine atom is used as an auxiliary agent, as the non-aqueous solvent other than the cyclic carbonate having a fluorine atom, the above-exemplified non-aqueous solvent may be used alone, or two or more thereof. May be used in any combination and ratio.
For example, one preferred combination of non-aqueous solvents is a combination mainly composed of a cyclic carbonate having no fluorine atom and a chain carbonate.

  Among them, the total of the cyclic carbonate having no fluorine atom and the chain carbonate in the non-aqueous solvent is preferably 70% by volume or more, more preferably 80% by volume or more, further preferably 90% by volume or more, and The ratio of the cyclic carbonate having no fluorine atom to the total of the cyclic carbonate and the chain carbonate is preferably 5% by volume or more, more preferably 10% by volume or more, further preferably 15% by volume or more, and preferably It is 50 volume% or less, More preferably, it is 35 volume% or less, More preferably, it is 30 volume% or less, Most preferably, it is 25 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.
For example, as a specific example of a preferable combination of a cyclic carbonate having no fluorine atom and a chain carbonate,

  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 carbonate, ethylene carbonate and diethyl carbonate and ethyl methyl carbonate, ethylene carbonate And dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, propylene carbonate and ethyl methyl carbonate, propylene carbonate, ethyl methyl carbonate and diethyl carbonate, propylene carbonate, ethyl methyl carbonate and dimethyl carbonate.

  Among the combinations of cyclic carbonates having no fluorine atoms and chain carbonates, those containing asymmetric chain alkyl carbonates as chain carbonates are more preferable, and in particular, ethylene carbonate and ethyl methyl carbonate, propylene carbonate and ethyl Cycling characteristics and large current are methyl carbonate, ethylene carbonate and ethyl methyl carbonate and dimethyl carbonate, ethylene carbonate and ethyl methyl carbonate and diethyl carbonate, propylene carbonate and ethyl methyl carbonate and dimethyl carbonate, propylene carbonate, ethyl methyl carbonate and diethyl carbonate, etc. This is preferable because the discharge characteristics are well balanced.

Among them, the asymmetric chain carbonate is preferably ethyl methyl carbonate, and the alkyl group of the chain carbonate preferably has 1 to 2 carbon atoms.
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 even more preferably 25% by volume or more. Preferably it is 30% by volume or more, preferably 90% by volume or less, more preferably 80% by volume or less, further preferably 75% by volume or less, and particularly preferably 70% by volume or less. 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 electric conductivity of the electrolyte can be maintained, but the battery characteristics after high temperature storage are improved. 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 preferable, 1.5 or more is more preferable, and 2.5 or more is more preferable. 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.

In the combination mainly composed of a cyclic carbonate having no fluorine atom and a chain carbonate, a cyclic carboxylic acid ester, a chain carboxylic acid ester, a cyclic ether, a chain ether, a sulfur-containing organic solvent, a phosphorus-containing solvent You may mix other solvents, such as an organic solvent and an aromatic fluorine-containing solvent.
In this specification, the volume of the non-aqueous solvent is a measured value at 25 ° C., but the measured value at the melting point is used for a solid at 25 ° C. such as ethylene carbonate.

1-4. Auxiliary agent In the non-aqueous electrolyte battery of the present invention, a compound containing a structure represented by the following general formula (A), a halogenated cyclic carbonate compound, a nitrile compound, an isocyanate compound, a difluorophosphate, and a monofluorosulfonic acid In addition to at least one compound selected from the group consisting of salts, auxiliary agents may be appropriately used according to the purpose. As the auxiliary agent, the following cyclic carbonate having a carbon-carbon unsaturated bond, an acid anhydride compound, a compound having an isocyanuric acid skeleton, a vinyl sulfonic acid ester compound, an aromatic compound having 12 or less carbon atoms, fluorination resistance Examples include saturated cyclic carbonates, compounds having triple bonds, other auxiliaries, and the like. Cyclic carbonates having carbon-carbon unsaturated bonds, acid anhydride compounds, compounds having an isocyanuric acid skeleton, vinyl sulfonate compounds, carbon An aromatic compound having a number of 12 or less is preferred.

1-4-1. Cyclic carbonate having carbon-carbon unsaturated bond Cyclic carbonate having carbon-carbon unsaturated bond (hereinafter sometimes referred to as “unsaturated cyclic carbonate”) includes a carbon-carbon double bond or a carbon-carbon triple bond. Any cyclic carbonate having a bond is not particularly limited, and any unsaturated carbonate can be used. The cyclic carbonate having an aromatic ring is also included in the unsaturated cyclic carbonate.

As unsaturated cyclic carbonate,
Examples include vinylene carbonates, ethylene carbonates substituted with an aromatic ring or a substituent having a carbon-carbon double bond or carbon-carbon triple bond, phenyl carbonates, vinyl carbonates, allyl carbonates, catechol carbonates, and the like. .

As vinylene carbonates,
Vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, phenyl vinylene carbonate, 4,5-diphenyl vinylene carbonate, vinyl vinylene carbonate, 4,5-divinyl vinylene carbonate, allyl vinylene carbonate, 4,5-diallyl vinylene carbonate 4-fluoro vinylene carbonate, 4-fluoro-5-methyl vinylene carbonate, 4-fluoro-5-phenyl vinylene carbonate, 4-fluoro-5-vinyl vinylene carbonate, 4-allyl-5-fluoro vinylene carbonate and the like. .

Specific examples of ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond include:
Vinylethylene carbonate, 4,5-divinylethylene carbonate, 4-methyl-5-vinylethylene carbonate, 4-allyl-5-vinylethylene carbonate, ethynylethylene carbonate, 4,5-diethynylethylene carbonate, 4-methyl-5
-Ethynylethylene carbonate, 4-vinyl-5-ethynylethylene carbonate, 4-allyl-5-ethynylethylene carbonate, phenylethylene carbonate, 4,5-diphenylethylene carbonate, 4-phenyl-5-vinylethylene carbonate, 4-allyl Examples include -5-phenylethylene carbonate, allylethylene carbonate, 4,5-diallylethylene carbonate, 4-methyl-5-allylethylene carbonate, and the like.

Among these, as an unsaturated cyclic carbonate particularly preferable for use in combination with the compound represented by the formula (1),
Vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, vinyl vinylene carbonate, 4,5-vinyl vinylene carbonate, allyl vinylene carbonate, 4,5-diallyl vinylene carbonate, vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate 4-methyl-5-vinylethylene carbonate, allylethylene carbonate, 4,5-diallylethylene carbonate, 4-methyl-5-allylethylene carbonate, 4-allyl-5-vinylethylene carbonate, ethynylethylene carbonate, 4,5 -Diethynyl ethylene carbonate, 4-methyl-5-ethynyl ethylene carbonate, 4-vinyl-5-ethynyl ethylene carbonate. Vinylene carbonate, vinyl ethylene carbonate, and ethynyl ethylene carbonate are particularly preferable because they form a more stable interface protective film.

  The molecular weight of the unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. The molecular weight is preferably 80 or more and 250 or less. If it is this range, it will be easy to ensure the solubility of the unsaturated cyclic carbonate with respect to a non-aqueous electrolyte solution, and the effect of this invention will fully be expressed easily. The molecular weight of the unsaturated cyclic carbonate is more preferably 85 or more, and more preferably 150 or less.

The production method of the unsaturated cyclic carbonate is not particularly limited, and can be produced by arbitrarily selecting a known method.
An unsaturated cyclic carbonate may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and a ratio. Moreover, the compounding quantity of unsaturated cyclic carbonate is not restrict | limited in particular, As long as the effect of this invention is not impaired remarkably, it is arbitrary. The blending amount of the unsaturated cyclic carbonate is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and further preferably 0.1% by mass or more, in 100% by mass of the non-aqueous electrolyte solution. Moreover, Preferably it is 5 mass% or less, More preferably, it is 4 mass% or less, More preferably, it is 3 mass% or less. Within this range, the non-aqueous electrolyte battery tends to exhibit a sufficient cycle characteristics improvement effect, and the high temperature storage characteristics deteriorate, the amount of gas generated increases, and the discharge capacity maintenance ratio decreases. Easy to avoid.

1-4-2. Acid anhydride compound Acid anhydride compounds include carboxylic acid anhydride, sulfuric acid anhydride, nitric acid anhydride, sulfonic acid anhydride, phosphoric acid anhydride, phosphorous acid anhydride, cyclic acid anhydride, chain The structure of the acid anhydride compound is not particularly limited as long as it is an acid anhydride compound.

Specific examples of the acid anhydride compound include, for example,
Malonic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, maleic anhydride, citraconic anhydride, 2,3-dimethylmaleic anhydride, glutaconic anhydride, itaconic anhydride, phthalic anhydride, phenylmaleic anhydride 2,3-diphenylmaleic anhydride, cyclohexane-1,2-dicarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, 4 , 4′-oxydiphthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, phenylsuccinic anhydride, 2-phenylglutaric anhydride , Allyl succinic anhydride, 2-buten-11-yl succinic anhydride, (2-methyl-2-propenyl) succinic anhydride, no tetrafluorosuccinic acid Water, diacetyl-tartaric anhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-Methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, methacrylic acid anhydride, acrylic acid anhydride, crotonic acid anhydride, methanesulfonic acid anhydride, trifluoromethanesulfonic acid anhydride, nonafluorobutanesulfone An acid anhydride, an acetic anhydride, etc. are mentioned.

Of these,
Succinic anhydride, maleic anhydride, citraconic anhydride, phenylmaleic anhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5- (2 ,
5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, allyl succinic anhydride, acetic anhydride, methacrylic anhydride, acrylic anhydride, methanesulfonic anhydride Particularly preferred.

An acid anhydride compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
There is no limit to the amount of the acid anhydride compound with respect to the entire non-aqueous electrolyte of the present invention, and it is optional as long as the effects of the present invention are not significantly impaired. It is contained at a concentration of not less than mass%, preferably not less than 0.1 mass%, more preferably not less than 0.3 mass%, and usually not more than 10 mass%, preferably not more than 5 mass%, more preferably not more than 3 mass%. .

When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.
1-4-3. Compound having an isocyanuric acid skeleton The type of the compound having an isocyanuric acid skeleton is not particularly limited as long as it is a compound having an isocyanuric acid skeleton in the molecule.
Specific examples of the compound having an isocyanuric acid skeleton include, for example,

Above all,

Is preferred.
A compound having an isocyanuric acid skeleton may be used alone or in combination of two or more in any combination and ratio.
The compounding amount of the compound having an isocyanuric acid skeleton with respect to the whole non-aqueous electrolyte solution of the present invention is not limited, and is arbitrary as long as the effects of the present invention are not significantly impaired. 0.001% by mass or more, preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less. Contain.

When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.
1-4-4. Vinyl sulfonic acid ester compound The type of vinyl sulfonic acid ester compound is not particularly limited as long as it is a compound having a vinyl sulfonic acid ester structure in the molecule.

  Specific examples of the vinyl sulfonate compound include, for example,

Above all,

Is preferred.
A vinyl sulfonic acid ester compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. There is no restriction | limiting in the compounding quantity of the vinyl sulfonic acid ester compound with respect to the whole non-aqueous electrolyte solution of this invention, and it is arbitrary unless the effect of this invention is impaired remarkably, but with respect to the non-aqueous electrolyte solution of this invention, it is usually 0.00. 001% by mass or more, preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less. Let When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-4-5. Aromatic compound having 12 or less carbon atoms The aromatic compound having 12 or less carbon atoms is not particularly limited as long as it is a compound having 12 or less carbon atoms in the molecule.
As a specific example of an aromatic compound having a carbon nest of 12 or less, for example,
Aromatic compounds such as biphenyl, alkylbiphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran, etc .; Partially fluorinated product;
Examples thereof include fluorine-containing anisole compounds such as 2,4-difluoroanisole, 2,5-difluoroanisole, 2,6-difluoroanisole, and 3,5-difluoroanisole. Above all,
Aromatic compounds such as biphenyl, alkylbiphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether and dibenzofuran are preferred.

  These may be used alone or in combination of two or more. When two or more kinds are used in combination, in particular, a combination of cyclohexylbenzene and t-butylbenzene or t-amylbenzene, aroma not containing oxygen such as biphenyl, alkylbiphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, etc. It is preferable to use at least one selected from group compounds and at least one selected from oxygen-containing aromatic compounds such as diphenyl ether and dibenzofuran from the viewpoint of the balance of high-temperature storage characteristics.

The aromatic compound having 12 or less carbon atoms is not particularly limited, and is arbitrary as long as the effects of the present invention are not significantly impaired. The overcharge inhibitor is preferably 0.1% by mass or more and 5% by mass or less in 100% by mass of the non-aqueous electrolyte solution. If it is this range, it will be easy to fully express the effect of an overcharge inhibiting agent, and it will be easy to avoid the situation where the characteristics of batteries, such as a high temperature storage characteristic, fall.
The aromatic compound having 12 or less carbon atoms is more preferably 0.2% by mass or more, further preferably 0.3% by mass or more, particularly preferably 0.5% by mass or more, and more preferably 3% by mass. Hereinafter, it is more preferably 2% by mass or less.

1-4-6. Fluorinated unsaturated cyclic carbonate As the fluorinated cyclic carbonate, it is also preferable to use a cyclic carbonate having an unsaturated bond and a fluorine atom (hereinafter sometimes referred to as “fluorinated unsaturated cyclic carbonate”). The number of fluorine atoms contained in the fluorinated unsaturated cyclic carbonate is not particularly limited as long as it is 1 or more. Among them, the fluorine atom is usually 6 or less, preferably 4 or less, and most preferably 1 or 2.

Examples of the fluorinated unsaturated cyclic carbonate include fluorinated vinylene carbonate derivatives, fluorinated ethylene carbonate derivatives substituted with an aromatic ring or a substituent having a carbon-carbon double bond.
Fluorinated vinylene carbonate derivatives include 4-fluoro vinylene carbonate, 4-fluoro-5-methyl vinylene carbonate, 4-fluoro-5-phenyl vinylene carbonate, 4-allyl-5-fluoro vinylene carbonate, 4-fluoro-5- And vinyl vinylene carbonate.

As the fluorinated ethylene carbonate derivative substituted with a substituent having an aromatic ring or a carbon-carbon double bond,
4-fluoro-4-vinylethylene carbonate, 4-fluoro-4-allylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, 4-fluoro-5-allylethylene carbonate, 4,4-difluoro-4-vinylethylene Carbonate, 4,4-difluoro-4-allylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4,5-difluoro-4-allylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4-fluoro-4,5-diallylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, 4,
5-difluoro-4,5-diallylethylene carbonate, 4-fluoro-4-phenylethylene carbonate, 4-fluoro-5-phenylethylene carbonate, 4,4-difluoro-5-phenylethylene carbonate, 4,5-difluoro- 4-phenylethylene carbonate etc. are mentioned.

Among these, as a preferable fluorinated unsaturated cyclic carbonate,
4-fluoro vinylene carbonate, 4-fluoro-5-methyl vinylene carbonate, 4-fluoro-5-vinyl vinylene carbonate, 4-allyl-5-fluoro vinylene carbonate, 4-fluoro-4-vinyl ethylene carbonate, 4-fluoro- 4-allylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, 4-fluoro-5-allylethylene carbonate, 4,4-difluoro-4-vinylethylene carbonate, 4,4-difluoro-4-allylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4,5-difluoro-4-allylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4-fluoro-4,5-diallylethylene carbonate 4,5-difluoro-4,5-divinyl ethylene carbonate, 4,5-difluoro-4,5-diallyl ethylene carbonate, because it forms a stable interface protective coating, more preferably used.

The molecular weight of the fluorinated unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. The molecular weight is preferably 50 or more and 250 or less. If it is this range, it will be easy to ensure the solubility of the fluorinated cyclic carbonate with respect to non-aqueous electrolyte solution, and the effect of this invention will be easy to be expressed.
The production method of the fluorinated unsaturated cyclic carbonate is not particularly limited, and can be produced by arbitrarily selecting a known method. The molecular weight is more preferably 100 or more, and more preferably 200 or less.

A fluorinated unsaturated cyclic carbonate may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Further, the blending amount of the fluorinated unsaturated cyclic carbonate is not particularly limited, and is arbitrary as long as the effects of the present invention are not significantly impaired.
The compounding amount of the fluorinated unsaturated cyclic carbonate is usually 0.01% by mass or more, more preferably 0.1% by mass or more, further preferably 0.2% by mass or more, in 100% by mass of the nonaqueous electrolytic solution. Moreover, it is preferably 5% by mass or less, more preferably 4% by mass or less, and further preferably 3% by mass or less.
Within this range, the non-aqueous electrolyte battery tends to exhibit a sufficient cycle characteristics improvement effect, and the high temperature storage characteristics deteriorate, the amount of gas generated increases, and the discharge capacity maintenance ratio decreases. Easy to avoid.

1-4-7. Compound having triple bond The compound having a triple bond is not particularly limited as long as it is a compound having one or more triple bonds in the molecule.
Specific examples of the compound having a triple bond include the following compounds.
1-pentyne, 2-pentyne, 1-hexyne, 2-hexyne, 3-hexyne, 1-heptin, 2-heptin, 3-heptin, 1-octyne, 2-octyne, 3-octyne, 4-octyne, 1- Nonin, 2-nonine, 3-nonine, 4-nonine, 1-dodecin, 2-dodecin, 3-dodecin, 4-dodecin, 5-dodecin, phenylacetylene, 1-phenyl-1-propyne, 1-phenyl-2 -Propyne, 1-phenyl-1-butyne, 4-phenyl-1-butyne, 4-phenyl-1-butyne, 1-phenyl-1-pentyne, 5-phenyl-1-pentyne, 1-phenyl-1-hexyne Hydrocarbon compounds such as 6-phenyl-1-hexyne, diphenylacetylene, 4-ethynyltoluene, and dicyclohexylacetylene;

2-propynylmethyl carbonate, 2-propynylethyl carbonate, 2-propynylpropyl carbonate, 2-propynylbutyl carbonate, 2-propynylphenyl carbonate, 2-propynylcyclohexyl carbonate, di-2-propynyl carbonate, 1-methyl-2-propynyl Methyl carbonate, 1,1-dimethyl-2-propynyl methyl carbonate, 2-butynyl methyl carbonate, 3-butynyl methyl carbonate, 2-pentynyl methyl carbonate, 3-pentynyl methyl carbonate, 4-pentynyl methyl carbonate, Monocarbonates such as;
2-butyne-1,4-diol dimethyl dicarbonate, 2-butyne-1,4-diol diethyl dicarbonate, 2-butyne-1,4-diol dipropyl dicarbonate, 2-butyne-1,4-diol dibutyl Dicarbonates such as dicarbonate, 2-butyne-1,4-diol diphenyl dicarbonate, 2-butyne-1,4-diol dicyclohexyl dicarbonate;

  2-propynyl acetate, 2-propynyl propionate, 2-propynyl butyrate, 2-propynyl benzoate, 2-propynyl cyclohexylcarboxylate, acetic acid 1, 1-dimethyl-2-propynyl, 1, propionic acid 1, 1-dimethyl-2- Propynyl, butyric acid 1,1-dimethyl-2-propynyl, benzoic acid 1,1-dimethyl-2-propynyl, cyclohexylcarboxylic acid 1,1-dimethyl-2-propynyl, 2-butynyl acetate, 3-butynyl acetate, acetic acid 2 -Pentynyl, 3-pentynyl acetate, 4-pentynyl acetate, methyl acrylate, ethyl acrylate, propyl acrylate, vinyl acrylate, 2-propenyl acrylate, 2-butenyl acrylate, 3-butenyl acrylate, methyl methacrylate , Ethyl methacrylate, propyl methacrylate, methacrylate Vinyl proprate, 2-propenyl methacrylate, 2-butenyl methacrylate, 3-butenyl methacrylate, methyl 2-propinate, ethyl 2-propinate, propyl 2-propinate, vinyl 2-propinate, 2-propionic acid 2-propenyl, 2-butenyl 2-propanoate, 3-butenyl 2-propinate, methyl 2-butyrate, 2-ethyl butyrate, propyl 2-butyrate, vinyl 2-butyrate, 2-butynoic acid 2- Propenyl, 2-butenyl 2-butyrate, 3-butenyl 2-butyrate, methyl 3-butyrate, ethyl 3-butyrate, propyl 3-butyrate, vinyl 3-butyrate, 2-propenyl 3-butyrate, 2-butenyl 3-butynoate, 3-butenyl 3-butyrate, methyl 2-pentynoate, ethyl 2-pentynoate, propyl 2-pentynoate, 2- Vinyl pentinate, 2-propenyl 2-pentylate, 2-butenyl 2-pentinate, 3-butenyl 2-pentinate, methyl 3-pentinate, ethyl 3-pentanoate, propyl 3-pentanoate, 3-pentynoic acid Vinyl, 2-propenyl 3-pentynoate, 2-butenyl 3-pentynoate, 3-butenyl 3-pentynoate, methyl 4-pentynoate, ethyl 4-pentynoate, propyl 4-pentynoate, vinyl 4-pentynoate, Monocarboxylic acid esters such as 2-propenyl 4-pentynoate, 2-butenyl 4-pentynoate and 3-butenyl 4-pentynoate;

2-butyne-1,4-diol diacetate, 2-butyne-1,4-diol dipropionate, 2-butyne-1,4-diol dibutyrate, 2-butyne-1,4-diol dibenzoate, 2-butyne Dicarboxylic acid esters such as -1,4-diol dicyclohexanecarboxylate;
Methyl oxalate 2-propynyl, ethyl oxalate 2-propynyl, propyl oxalate 2-propynyl, 2-propynyl oxalate vinyl, allyl oxalate 2-propynyl, di-2-propynyl oxalate, 2-butynyl methyl oxalate, 2-butynylethyl oxalate, 2-butynylpropyl oxalate, 2-butynyl vinyl oxalate, allyl 2-butynyl oxalate, di-2-butynyl oxalate, 3-butynyl methyl oxalate, 3-butynyl ethyl oxalate Oxalic acid diesters such as 3-butynylpropyl oxalate, 3-butynylvinyl oxalate, allyl 3-butynyl oxalate, and di-3-butynyl oxalate;

Methyl (2-propynyl) (vinyl) phosphine oxide, divinyl (2-propynyl) phosphine oxide, di (2-propynyl) (vinyl) phosphine oxide, di (2-propenyl) 2 (-propynyl) phosphine oxide, di (2 Phosphine oxides such as -propynyl) (2-propenyl) phosphine oxide, di (3-butenyl) (2-propynyl) phosphine oxide, and di (2-propynyl) (3-butenyl) phosphine oxide;
2-propynyl methyl (2-propenyl) phosphinate, 2-propynyl 2-butenyl (methyl) phosphinate, 2-propynyl di (2-propenyl) phosphinate, 2-propynyl di (3-butenyl) phosphinate, methyl ( 2-propenyl) phosphinic acid 1,1-dimethyl-2-propynyl, 2-butenyl (methyl) phosphinic acid 1,1-dimethyl-2-propynyl, di (2-propenyl) phosphinic acid 1,1-dimethyl-2- Propynyl, and 1,1-dimethyl-2-propynyl di (3-butenyl) phosphinate, 2-propenyl methyl (2-propynyl) phosphinate, 3-butenyl methyl (2-propynyl) phosphinate, di (2-propynyl) ) 2-propenyl phosphinate, 3-butenyl di (2-propynyl) phosphinate, 2 Propynyl (2-propenyl) phosphinic acid 2-propenyl, and 2-propynyl (2-propenyl) phosphinic acid 3-phosphinic acid esters butenyl;

  2-propenylphosphonic acid methyl 2-propynyl, 2-butenylphosphonic acid methyl (2-propynyl), 2-propenylphosphonic acid (2-propynyl) (2-propenyl), 3-butenylphosphonic acid (3-butenyl) (2-propynyl) ), 2-propenylphosphonic acid (1,1-dimethyl-2-propynyl) (methyl), 2-butenylphosphonic acid (1,1-dimethyl-2-propynyl) (methyl), 2-propenylphosphonic acid (1,1 -Dimethyl-2-propynyl) (2-propenyl), and 3-butenylphosphonic acid (3-butenyl) (1,1-dimethyl-2-propynyl), methylphosphonic acid (2-propynyl) (2-propenyl), methylphosphonic acid (3-butenyl) (2-propynyl), methylphosphonic acid (1,1-dimethyl-2-propyl) Pinyl) (2-propenyl), methylphosphonic acid (3-butenyl) (1,1-dimethyl-2-propynyl), ethylphosphonic acid (2-propynyl) (2-propenyl), ethylphosphonic acid (3-butenyl) ( 2-propynyl), phosphonic acid esters such as ethylphosphonic acid (1,1-dimethyl-2-propynyl) (2-propenyl), and ethylphosphonic acid (3-butenyl) (1,1-dimethyl-2-propynyl) ;

Phosphoric acid (methyl) (2-propenyl) (2-propynyl), phosphoric acid (ethyl) (2-propenyl) (2-propynyl), phosphoric acid (2-butenyl) (methyl) (2-propynyl), phosphoric acid (2-butenyl) (ethyl) (2-propynyl), phosphoric acid (1,1-dimethyl-2-propynyl) (methyl) (2-propenyl), phosphoric acid (1,1-dimethyl-2-propynyl) ( Ethyl) (2-propenyl), phosphoric acid (2-butenyl) (1,1-dimethyl-2-propynyl) (methyl), and phosphoric acid (2-butenyl) (ethyl) (1,1-dimethyl-2-phenyl) Phosphate esters such as propynyl);
Among these, a compound having an alkynyloxy group is preferable because it forms a negative electrode film more stably in the electrolytic solution.

further,
2-propynylmethyl carbonate, di-2-propynyl carbonate, 2-butyne-1,4-diol dimethyl dicarbonate, 2-propynyl acetate, 2-butyne-1,4-diol diacetate, methyl oxalate 2-propynyl , And compounds such as di-2-propynyl oxalate are particularly preferable from the viewpoint of improving storage characteristics.

  The said compound which has a triple bond may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. The compounding amount of the compound having a triple bond with respect to the entire non-aqueous electrolyte solution of the present invention is not limited, and is arbitrary as long as the effects of the present invention are not significantly impaired. 01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less, more preferably 1% by mass or less Let When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-4-8. Other auxiliaries As other auxiliaries, known auxiliaries other than the above auxiliaries can be used. As other auxiliaries,
Carbonate compounds such as erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl-methyl carbonate;
Spiro compounds such as 2,4,8,10-tetraoxaspiro [5.5] undecane and 3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane;
Ethylene sulfite, methyl fluorosulfonate, ethyl fluorosulfonate, methyl methanesulfonate, ethyl methanesulfonate, busulfan, sulfolene, diphenylsulfone, N, N-dimethylmethanesulfonamide, N, N-diethylmethanesulfonamide, vinyl Methyl sulfonate, ethyl vinyl sulfonate, allyl vinyl sulfonate, propargyl vinyl sulfonate, methyl allyl sulfonate, ethyl allyl sulfonate, allyl sulfonate, propargyl allyl sulfonate, 1,2-bis (vinylsulfonoxy) Sulfur-containing compounds such as ethane;

Nitrogen-containing compounds such as 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone and N-methylsuccinimide;
Trimethyl phosphite, triethyl phosphite, triphenyl phosphite, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, dimethyl methylphosphonate, diethyl ethylphosphonate, dimethyl vinylphosphonate, diethyl vinylphosphonate, diethylphospho Phosphorus-containing compounds such as ethyl noacetate, methyl dimethylphosphinate, ethyl diethylphosphinate, trimethylphosphine oxide, triethylphosphine oxide;

Hydrocarbon compounds such as heptane, octane, nonane, decane, cycloheptane;
Fluorine-containing aromatic compounds such as fluorobenzene, difluorobenzene, hexafluorobenzene and benzotrifluoride;
Etc. These may be used alone or in combination of two or more. By adding these auxiliaries, capacity maintenance characteristics and cycle characteristics after high temperature storage can be improved.

The blending amount of other auxiliary agents is not particularly limited, and is arbitrary as long as the effects of the present invention are not significantly impaired. The other auxiliary agent is preferably 0.01% by mass or more and 5% by mass or less in 100% by mass of the non-aqueous electrolyte solution. Within this range, the effects of other auxiliaries can be sufficiently exhibited, and it is easy to avoid a situation in which battery characteristics such as high-load discharge characteristics deteriorate.
The blending amount of other auxiliaries is more preferably 0.1% by mass or more, further preferably 0.2% by mass or more, more preferably 3% by mass or less, and further preferably 1% by mass or less. .

As mentioned above, what exists in the inside of the non-aqueous electrolyte battery as described in this invention is also contained in the above-mentioned non-aqueous electrolyte.
Specifically, the components of the non-aqueous electrolyte solution such as lithium salt, solvent, and auxiliary agent are separately synthesized, and the non-aqueous electrolyte solution is prepared from what is substantially isolated by the method described below. In the case of a nonaqueous electrolyte solution in a nonaqueous electrolyte battery obtained by pouring into a separately assembled battery, the components of the nonaqueous electrolyte solution of the present invention are individually placed in the battery, In order to obtain the same composition as the non-aqueous electrolyte solution of the present invention by mixing in a non-aqueous electrolyte battery, the compound constituting the non-aqueous electrolyte solution of the present invention is further generated in the non-aqueous electrolyte battery. The case where the same composition as the aqueous electrolyte is obtained is also included.

2. Battery Configuration The non-aqueous electrolyte battery of the present invention is suitable for use as an electrolyte for a secondary battery, for example, a lithium secondary battery, among non-aqueous electrolyte batteries. Hereinafter, a non-aqueous electrolyte battery using the non-aqueous electrolyte of the present invention will be described.
The non-aqueous electrolyte battery of the present invention can adopt a known structure. Typically, the negative electrode and the positive electrode capable of occluding and releasing ions (for example, lithium ions), and the non-aqueous electrolysis of the present invention described above. Liquid.

2-1. Negative electrode The negative electrode active material used for the negative electrode is described below. The negative electrode active material is not particularly limited as long as it can electrochemically occlude and release lithium ions. Specific examples include carbonaceous materials, alloy materials, lithium-containing metal composite oxide materials, and the like. These may be used individually by 1 type, and may be used together combining 2 or more types arbitrarily.

<Negative electrode active material>
Examples of the negative electrode active material include carbonaceous materials, alloy materials, lithium-containing metal composite oxide materials, and the like.
Examples of the carbonaceous material include (1) natural graphite, (2) artificial graphite, (3) amorphous carbon, (4) carbon-coated graphite, (5) graphite-coated graphite, and (6) resin-coated graphite. .

(1) Examples of natural graphite include scaly graphite, scaly graphite, soil graphite, and / or graphite particles obtained by subjecting these graphites to spheroidization or densification. Among these, spherical or ellipsoidal graphite subjected to spheroidizing treatment is particularly preferable from the viewpoints of particle filling properties and charge / discharge rate characteristics.
As an apparatus used for the spheroidization treatment, for example, an apparatus that repeatedly gives mechanical action such as compression, friction, shearing force, etc. including the interaction of particles mainly with impact force to the particles can be used. Specifically, it has a rotor with a large number of blades installed inside the casing, and mechanical action such as impact compression, friction, shearing force, etc. on the carbon material introduced inside the rotor by rotating at high speed. And a device for performing the spheroidizing treatment is preferable. Moreover, it is preferable to have a mechanism that repeatedly gives mechanical action by circulating the carbon material.

  For example, when the spheroidizing treatment is performed using the above-described apparatus, the peripheral speed of the rotating rotor is preferably 30 to 100 m / second, more preferably 40 to 100 m / second, and 50 to 100 m / second. More preferably. The treatment can be performed by simply passing a carbonaceous material, but it is preferable to circulate or stay in the apparatus for 30 seconds or longer, and it is preferable to circulate or stay in the apparatus for 1 minute or longer. More preferred.

(2) Artificial graphite includes coal tar pitch, coal heavy oil, atmospheric residue, petroleum heavy oil, aromatic hydrocarbon, nitrogen-containing cyclic compound, sulfur-containing cyclic compound, polyphenylene, polyvinyl chloride, Organic compounds such as polyvinyl alcohol, polyacrylonitrile, polyvinyl butyral, natural polymer, polyphenylene sulfide, polyphenylene oxide, furfuryl alcohol resin, phenol-formaldehyde resin, imide resin are usually in the range of 2500 ° C. or higher and usually 3200 ° C. or lower. Examples thereof include those produced by graphitization at a temperature and, if necessary, pulverized and / or classified. At this time, a silicon-containing compound or a boron-containing compound can also be used as a graphitization catalyst. In addition, artificial graphite obtained by graphitizing mesocarbon microbeads separated in the heat treatment process of pitch can be mentioned. Furthermore, the artificial graphite of the granulated particle which consists of primary particles is also mentioned. For example, by mixing mesocarbon microbeads and graphitizable carbonaceous material powders such as coke, graphitizable binders such as tar and pitch, and graphitization catalyst, graphitizing, and pulverizing as necessary Examples of the resulting graphite particles include a plurality of flat particles and aggregated or bonded so that the orientation planes are non-parallel.

(3) As amorphous carbon, amorphous carbon that has been heat-treated at least once in a temperature range (400 to 2200 ° C.) in which no graphitizable carbon precursor such as tar or pitch is used as a raw material. Examples thereof include amorphous carbon particles that are heat-treated using particles or a non-graphitizable carbon precursor such as a resin as a raw material.
(4) Carbon-coated graphite can be obtained by mixing natural graphite and / or artificial graphite with a carbon precursor that is an organic compound such as tar, pitch, or resin, and heat-treating it at least once in the range of 400 to 2300 ° C. Examples thereof include a carbon graphite composite in which natural graphite and / or artificial graphite is used as nuclear graphite, and amorphous carbon coats the nuclear graphite. The composite form may cover the entire surface or a part thereof, or may be a composite of a plurality of primary particles using carbon originating from the carbon precursor as a binder. Carbon can also be deposited (CVD) by reacting natural graphite and / or artificial graphite with hydrocarbon gases such as benzene, toluene, methane, propane, and aromatic volatiles at a high temperature to deposit carbon on the graphite surface. A graphite composite can also be obtained.

(5) As graphite-coated graphite, natural graphite and / or artificial graphite and a carbon precursor of an easily graphitizable organic compound such as tar, pitch or resin are mixed and once in a range of about 2400 to 3200 ° C. Examples thereof include graphite-coated graphite in which natural graphite and / or artificial graphite obtained by heat treatment is used as nuclear graphite, and graphitized material covers the whole or part of the surface of nuclear graphite.
(6) As the resin-coated graphite, natural graphite and / or artificial graphite obtained by mixing natural graphite and / or artificial graphite with a resin and drying at a temperature of less than 400 ° C. is used as nuclear graphite, and the resin is nuclear graphite. And resin-coated graphite covering the surface.

Moreover, the carbonaceous material of (1)-(6) may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
Examples of organic compounds such as tar, pitch and resin used in the above (2) to (5) include coal-based heavy oil, direct-current heavy oil, cracked heavy petroleum oil, aromatic hydrocarbon, N-ring compound. , S ring compound, polyphenylene, organic synthetic polymer, natural polymer, thermoplastic resin and carbonizable organic compound selected from the group consisting of thermosetting resins. The raw material organic compound may be used after being dissolved in a low molecular organic solvent in order to adjust the viscosity at the time of mixing.

Moreover, as natural graphite and / or artificial graphite used as a raw material of nuclear graphite, natural graphite subjected to spheroidization treatment is preferable.
As an alloy material used as the negative electrode active material, as long as lithium can be occluded / released, lithium alone, simple metals and alloys forming lithium alloys, or oxides, carbides, nitrides, silicides, sulfides thereof Any of compounds such as products or phosphides may be used and is not particularly limited. The single metal and alloy forming the lithium alloy are preferably materials containing group 13 and group 14 metal / metalloid elements (that is, excluding carbon), more preferably aluminum, silicon and tin single metals and An alloy or compound containing these atoms. These may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

<Physical properties of carbonaceous materials>
When using a carbonaceous material as a negative electrode active material, it is desirable to have the following physical properties.
(X-ray parameters)
The d-value (interlayer distance) of the lattice plane (002 plane) obtained by X-ray diffraction by the Gakushin method of carbonaceous materials is usually 0.335 nm or more, usually 0.360 nm or less, and 0.350 nm. The following is preferable, and 0.345 nm or less is more preferable. Further, the crystallite size (Lc) of the carbonaceous material obtained by X-ray diffraction by the Gakushin method is preferably 1.0 nm or more, and more preferably 1.5 nm or more.

(Volume-based average particle size)
The volume-based average particle diameter of the carbonaceous material is a volume-based average particle diameter (median diameter) obtained by a laser diffraction / scattering method, and is usually 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, and 7 μm. The above is particularly preferable, and is usually 100 μm or less, preferably 50 μm or less, more preferably 40 μm or less, further preferably 30 μm or less, and particularly preferably 25 μm or less.

If the volume-based average particle size is below the above range, the irreversible capacity may increase, leading to loss of initial battery capacity. On the other hand, when the above range is exceeded, when an electrode is produced by coating, an uneven coating surface tends to be formed, which may be undesirable in the battery production process.
The volume-based average particle size is measured by dispersing carbon powder in a 0.2% by weight aqueous solution (about 10 mL) of polyoxyethylene (20) sorbitan monolaurate, which is a surfactant, and laser diffraction / scattering particle size distribution. This is performed using a meter (for example, LA-700 manufactured by Horiba, Ltd.). The median diameter determined by the measurement is defined as the volume-based average particle diameter of the carbonaceous material of the present invention.

(Raman R value)
The Raman R value of the carbonaceous material is a value measured using a laser Raman spectrum method, and is usually 0.01 or more, preferably 0.03 or more, more preferably 0.1 or more, and usually 1. 5 or less, preferably 1.2 or less, more preferably 1 or less, and particularly preferably 0.5 or less.

When the Raman R value is below the above range, the crystallinity of the particle surface becomes too high, and there are cases where the number of sites where Li enters between layers decreases with charge / discharge. That is, charge acceptance may be reduced. In addition, when the negative electrode is densified by applying it to the current collector and then pressing it, the crystals are likely to be oriented in a direction parallel to the electrode plate, which may lead to a decrease in load characteristics.
On the other hand, if it exceeds the above range, the crystallinity of the particle surface is lowered, the reactivity with the non-aqueous electrolyte is increased, and the efficiency may be lowered and the gas generation may be increased.

The Raman spectrum is measured by using a Raman spectrometer (for example, a Raman spectrometer manufactured by JASCO Corporation) to drop the sample naturally into the measurement cell and filling the sample cell with argon ion laser light (or a semiconductor). While irradiating a laser beam, the cell is rotated in a plane perpendicular to the laser beam. The resulting Raman spectrum, the intensity _{I A} of the peak _{P A} in the vicinity of 1580 cm ^-1, and measuring the intensity _{I B} of a peak _{P B} in the vicinity of 1360 cm ^-1, the intensity ratio _{R (R = I B / I} A) Is calculated. The Raman R value calculated by the measurement is defined as the Raman R value of the carbonaceous material of the present invention.

Moreover, said Raman measurement conditions are as follows.
・ Laser wavelength: Ar ion laser 514.5 nm (semiconductor laser 532 nm)
Measurement range: 1100 cm ^{−1 to} 1730 cm ⁻¹
-Raman R value: background processing,
-Smoothing processing: Simple average, 5 points of convolution

(BET specific surface area)
BET specific surface area of the carbonaceous material is a value of the measured specific surface area using the BET method is usually 0.1 m ² · ^{g -1} or more, 0.7 m ² · ^{g -1} or more, 1. 0 m ² · ^{g -1} or more, and particularly preferably 1.5 m ² · ^{g -1} or more, generally not more than 100 m ² · ^{g -1,} preferably ^{25 m} 2 · ^{g -1} or less, 15 m ² · g ^-1 more preferably less, ^{10 m} 2 · ^{g -1} or less are especially preferred.

  When the value of the BET specific surface area is less than this range, the acceptability of lithium is likely to deteriorate during charging when used as a negative electrode material, lithium is likely to precipitate on the electrode surface, and stability may be reduced. On the other hand, if it exceeds this range, when used as a negative electrode material, the reactivity with the non-aqueous electrolyte increases, gas generation tends to increase, and a preferable battery may be difficult to obtain.

  The specific surface area is measured by the BET method using a surface area meter (for example, a fully automated surface area measuring device manufactured by Okura Riken), preliminarily drying the sample at 350 ° C. for 15 minutes under nitrogen flow, Using a nitrogen helium mixed gas that is accurately adjusted so that the relative pressure value of nitrogen is 0.3, the nitrogen adsorption BET one-point method is performed by a gas flow method.

(Roundness)
When the circularity is measured as the degree of the sphere of the carbonaceous material, it is preferably within the following range. The circularity is defined as “circularity = (peripheral length of an equivalent circle having the same area as the particle projection shape) / (actual perimeter of the particle projection shape)”, and is theoretical when the circularity is 1. Become a true sphere.
The circularity of the particles having a particle size of 3 to 40 μm in the range of the carbonaceous material is desirably closer to 1, and is preferably 0.1 or more, more preferably 0.5 or more, and more preferably 0.8 or more, 0.85 or more is more preferable, and 0.9 or more is particularly preferable. High current density charge / discharge characteristics improve as the degree of circularity increases. Therefore, when the circularity is less than the above range, the filling property of the negative electrode active material is lowered, the resistance between particles is increased, and the high current density charge / discharge characteristics may be lowered for a short time.

  The circularity is measured using a flow type particle image analyzer (for example, FPIA manufactured by Sysmex Corporation). About 0.2 g of a sample was dispersed in a 0.2% by mass aqueous solution (about 50 mL) of polyoxyethylene (20) sorbitan monolaurate as a surfactant, and irradiated with 28 kHz ultrasonic waves at an output of 60 W for 1 minute. The detection range is specified as 0.6 to 400 μm, and the particle size is measured in the range of 3 to 40 μm.

  The method for improving the circularity is not particularly limited, but a sphere-shaped sphere is preferable because the shape of the interparticle void when the electrode body is formed is preferable. Examples of spheroidizing treatment include a method of mechanically approaching a sphere by applying a shearing force and a compressive force, a mechanical / physical processing method of granulating a plurality of fine particles by the binder or the adhesive force of the particles themselves, etc. Is mentioned.

(Tap density)
The tap density of the carbonaceous material is usually 0.1 g · cm ⁻³ or more, preferably 0.5 g · cm ⁻³ or more, more preferably 0.7 g · cm ⁻³ or more, and 1 g · cm ⁻³ or more. Particularly preferable, 2 g · cm ⁻³ or less is preferable, 1.8 g · cm ⁻³ or less is more preferable, and 1.6 g · cm ⁻³ or less is particularly preferable. When the tap density is below the above range, the packing density is difficult to increase when used as a negative electrode, and a high-capacity battery may not be obtained. On the other hand, when the above range is exceeded, there are too few voids between particles in the electrode, it is difficult to ensure conductivity between the particles, and it may be difficult to obtain preferable battery characteristics.

The tap density is measured by passing through a sieve having an opening of 300 μm, dropping the sample onto a 20 cm ³ tapping cell and filling the sample to the upper end surface of the cell, and then measuring a powder density measuring device (for example, manufactured by Seishin Enterprise Co., Ltd.). Using a tap denser, tapping with a stroke length of 10 mm is performed 1000 times, and the tap density is calculated from the volume at that time and the mass of the sample.

(Orientation ratio)
The orientation ratio of the carbonaceous material is usually 0.005 or more, preferably 0.01 or more, more preferably 0.015 or more, and usually 0.67 or less. When the orientation ratio is below the above range, the high-density charge / discharge characteristics may deteriorate. The upper limit of the above range is the theoretical upper limit value of the orientation ratio of the carbonaceous material.

The orientation ratio is measured by X-ray diffraction after pressure-molding the sample. Set the molding obtained by filling 0.47 g of the sample into a molding machine with a diameter of 17 mm and compressing it with 58.8 MN · m ^{-2 so} that it is flush with the surface of the sample holder for measurement. X-ray diffraction is measured. From the (110) diffraction and (004) diffraction peak intensities of the obtained carbon, a ratio represented by (110) diffraction peak intensity / (004) diffraction peak intensity is calculated.

The X-ray diffraction measurement conditions are as follows. “2θ” indicates a diffraction angle.
・ Target: Cu (Kα ray) graphite monochromator ・ Slit:
Divergence slit = 0.5 degree Light receiving slit = 0.15 mm
Scattering slit = 0.5 degree / measurement range and step angle / measurement time:
(110) plane: 75 degrees ≦ 2θ ≦ 80 degrees 1 degree / 60 seconds (004) plane: 52 degrees ≦ 2θ ≦ 57 degrees 1 degree / 60 seconds

(Aspect ratio (powder))
The aspect ratio of the carbonaceous material is usually 1 or more and usually 10 or less, preferably 8 or less, and more preferably 5 or less. If the aspect ratio exceeds the above range, streaking or a uniform coated surface cannot be obtained when forming an electrode plate, and the high current density charge / discharge characteristics may deteriorate. The lower limit of the above range is the theoretical lower limit value of the aspect ratio of the carbonaceous material.

  The aspect ratio is measured by magnifying and observing the carbonaceous material particles with a scanning electron microscope. Carbonaceous material particles when three-dimensional observation is performed by selecting arbitrary 50 graphite particles fixed to the end face of a metal having a thickness of 50 μm or less and rotating and tilting the stage on which the sample is fixed. The longest diameter A and the shortest diameter B orthogonal thereto are measured, and the average value of A / B is obtained.

<Alloy-based material negative electrode>
The negative electrode of the non-aqueous electrolyte secondary battery of the present invention contains an alloy-based material, preferably at least one atom selected from the group consisting of Si, Sn and Pb, as a negative electrode active material capable of occluding and releasing metal ions. May be a negative electrode (hereinafter sometimes referred to as “alloy-based material negative electrode”).

As described above, the non-aqueous electrolyte solution of the present invention is characterized by containing the compound (1), but the metal ion is different from the non-aqueous electrolyte solution containing the compound (1). When the anode active material capable of occluding / releasing at least one atom selected from the group consisting of Si, Sn and Pb is contained, a particularly beneficial effect can be obtained.

  Alloy material As the alloy material used as the negative electrode active material of the negative electrode, as long as lithium can be occluded / released, simple metals and alloys that form lithium alloys, or oxides / carbides / nitrides / silicides thereof Any compound such as sulfide or phosphide is not particularly limited, but preferably a single metal or alloy that forms a lithium alloy, Group 13 and Group 14 metal / metalloid elements of the periodic table It is preferable that there is a material containing (that is, excluding carbon), and further a simple metal of Si, Sn, and Pb (these may be referred to as “specific metal elements” hereinafter), and an alloy / compound containing these atoms. Something is preferable.

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

Examples of compounds containing one or more specific metal elements include carbides, oxides, nitrides, silicides, sulfides, phosphides, etc. containing one or more specific metal elements. Examples include complex compounds.
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 Si and Sn, an alloy of these elements and a metal that does not operate as a negative electrode can be used. In addition, for example, in Sn, a complex compound containing 5 to 6 kinds of elements in combination with a metal that acts as a negative electrode other than Sn, Si, Sn, and Pb, a metal that does not operate as a negative electrode, and a nonmetallic element is also included. Can 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 In particular, Si and / or Sn metals, alloys, oxides, carbides, nitrides, and the like are preferable from the viewpoint of capacity per unit mass and environmental load.
In addition, although the capacity per unit mass is inferior to that of a single metal or an alloy, the following compounds containing Si and / or Sn are also preferable because of excellent cycle characteristics.

The element ratio between Si and / or Sn and oxygen is usually 0.5 or more, preferably 0.7 or more, more preferably 0.9 or more, and usually 1.5 or less, preferably 1. Si and / or Sn oxides of 3 or less, more preferably 1.1 or less.
-Element ratio of Si and / or Sn and nitrogen is usually 0.5 or more, preferably 0.7 or more, more preferably 0.9 or more, and usually 1.5 or less, preferably 1. Si and / or Sn nitride of 3 or less, more preferably 1.1 or less.

-Element ratio of Si and / or Sn and carbon is usually 0.5 or more, preferably 0.7 or more, more preferably 0.9 or more, and usually 1.5 or less, preferably 1. 3 or less, and
Preferably, Si and / or Sn carbides of 1.1 or less.
In addition, any one of the above-described negative electrode active materials may be used alone, or two or more thereof may be used in any combination and ratio.

The alloy-based material negative electrode can be produced using any known method. Specifically, as a manufacturing method of the negative electrode, for example, a method in which a negative electrode active material added with a binder or a conductive material is roll-formed as it is to form a sheet electrode, or a compression-molded pellet electrode and The above negative electrode is usually applied to a negative electrode current collector (hereinafter also referred to as “negative electrode current collector”) by a method such as a coating method, a vapor deposition method, a sputtering method, or a plating method. A method of forming a thin film layer (negative electrode active material layer) containing an active material is used. In this case, by adding a binder, a thickener, a conductive material, a solvent, etc. to the above-mentioned negative electrode active material to form a slurry, applying this to the negative electrode current collector, drying, and pressing to increase the density A negative electrode active material layer is formed on the negative electrode current collector.

Examples of the material of the negative electrode current collector include steel, copper alloy, nickel, nickel alloy, and stainless steel. Of these, copper foil is preferred from the viewpoint of easy processing into a thin film and cost.
The thickness of the negative electrode current collector is usually 1 μm or more, preferably 5 μm or more, and is usually 100 μm or less, preferably 50 μm or less. If the thickness of the negative electrode current collector is too thick, the capacity of the entire battery may be too low, and conversely, if it is too thin, handling may be difficult.

  In addition, in order to improve the binding effect with the negative electrode active material layer formed on the surface, the surface of these negative electrode current collectors is preferably subjected to a roughening treatment in advance. Surface roughening methods include blasting, rolling with a rough roll, polishing cloth with a fixed abrasive particle, grinder, emery buff, wire brush equipped with steel wire, etc. Examples thereof include a mechanical polishing method, an electrolytic polishing method, and a chemical polishing method.

  Further, in order to reduce the mass of the negative electrode current collector and improve the energy density per mass of the battery, a perforated negative electrode current collector such as an expanded metal or a punching metal can be used. In this type of negative electrode current collector, the mass can be changed to white by changing the aperture ratio. Further, when a negative electrode active material layer is formed on both surfaces of this type of negative electrode current collector, the negative electrode active material layer is further less likely to peel due to the rivet effect through the hole. However, when the aperture ratio becomes too high, the contact area between the negative electrode active material layer and the negative electrode current collector becomes small, and thus the adhesive strength may be lowered.

The slurry for forming the negative electrode active material layer is usually prepared by adding a binder, a thickener and the like to the negative electrode material. In addition, the “negative electrode material” in this specification refers to a material in which a negative electrode active material and a conductive material are combined.
The content of the negative electrode active material in the negative electrode material is usually 70% by mass or more, particularly 75% by mass or more, and usually 97% by mass or less, particularly preferably 95% by mass or less. When the content of the negative electrode active material is too small, the capacity of the secondary battery using the obtained negative electrode tends to be insufficient. When the content is too large, the content of the conductive agent is relatively insufficient, so that It tends to be difficult to ensure conductivity. When two or more negative electrode active materials are used in combination, the total amount of the negative electrode active materials may be set to satisfy the above range.

Examples of the conductive material used for the negative electrode include metal materials such as copper and nickel; carbon materials such as graphite and carbon black. These may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio. In particular, it is preferable to use a carbon material as the conductive material because the carbon material acts as an active material. The content of the conductive material in the negative electrode material is usually 3% by mass or more, particularly 5% by mass or more, and usually 30% by mass or less, particularly 25% by mass or less.

It is preferable. When the content of the conductive material is too small, the conductivity tends to be insufficient. When the content is too large, the content of the negative electrode active material and the like is relatively insufficient, and thus the battery capacity and strength tend to decrease. Note that when two or more conductive materials are used in combination, the total amount of the conductive materials may satisfy the above range.

As the binder used for the negative electrode, any material can be used as long as it is a material safe with respect to the solvent and the electrolytic solution used at the time of producing the electrode. Examples thereof include polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, styrene / butadiene rubber / isoprene rubber, butadiene rubber, ethylene / acrylic acid copolymer, and ethylene / methacrylic acid copolymer. These may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio. It is preferable that the content of the binder is usually 0.5 parts by mass or more, particularly 1 part by mass or more, and usually 10 parts by mass or less, particularly 8 parts by mass or less with respect to 100 parts by mass of the negative electrode material. When the content of the binder is too small, the strength of the obtained negative electrode tends to be insufficient. When the content is too large, the content of the negative electrode active material and the like is relatively insufficient, and thus the battery capacity and conductivity tend to be insufficient. It becomes. In addition, when using two or more binders together, what is necessary is just to make it the total amount of a binder satisfy | fill the said range.

  Examples of the thickener used for the negative electrode include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, and casein. These may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio. The thickener may be used as necessary, but when used, the thickener content in the negative electrode active material layer is usually in the range of 0.5% by mass or more and 5% by mass or less. Is preferred.

  The slurry for forming the negative electrode active material layer is prepared by mixing a conductive agent, a binder, and a thickener as necessary with the negative electrode active material, and using an aqueous solvent or an organic solvent as a dispersion medium. The As the aqueous solvent, water is usually used, and an organic solvent such as alcohols such as ethanol and cyclic amides such as N-methylpyrrolidone is used in combination within a range of 30% by mass or less with respect to water. You can also. As the organic solvent, usually, cyclic amides such as N-methylpyrrolidone, linear amides such as N, N-dimethylformamide and N, N-dimethylacetamide, and aromatic carbonization such as anisole, toluene and xylene Examples thereof include alcohols such as hydrogens, butanol and cyclohexanol, among which cyclic amides such as N-methylpyrrolidone, linear amides such as N, N-dimethylformamide and N, N-dimethylacetamide are preferable. . Any one of these may be used alone, or two or more may be used in any combination and ratio.

  The obtained slurry is applied onto the above-described negative electrode current collector, dried, and then pressed to form a negative electrode active material layer. The method of application is not particularly limited, and a method known per se can be used. The drying method is not particularly limited, and a known method such as natural drying, heat drying, or reduced pressure drying can be used.

<Configuration and production method of negative electrode>
Any known method can be used for producing the electrode as long as the effects of the present invention are not significantly impaired. For example, it is formed by adding a binder, a solvent, and, if necessary, a thickener, a conductive material, a filler, etc. to a negative electrode active material to form a slurry, which is applied to a current collector, dried and then pressed. Can do.
In the case of using an alloy-based material, a method of forming a thin film layer (negative electrode active material layer) containing the above-described negative electrode active material by a technique such as vapor deposition, sputtering, or plating is also used.

(Electrode density)
The electrode structure when the negative electrode active material is made into an electrode is not particularly limited, but the density of the negative electrode active material present on the current collector is preferably 1 g · cm ⁻³ or more, and 1.2 g · cm ⁻³ or more. but more preferably, particularly preferably 1.3 g · ^{cm -3} or more, preferably 2.2 g · ^{cm -3} or less, more preferably 2.1 g · ^{cm -3} or less, 2.0 g · ^{cm -3} or less Further preferred is 1.9 g · cm ⁻³ or less. When the density of the negative electrode active material existing on the current collector exceeds the above range, the negative electrode active material particles are destroyed, and the initial irreversible capacity increases or non-aqueous system near the current collector / negative electrode active material interface. There is a case where high current density charge / discharge characteristics are deteriorated due to a decrease in permeability of the electrolytic solution. On the other hand, if the amount is less than the above range, the conductivity between the negative electrode active materials decreases, the battery resistance increases, and the capacity per unit volume may decrease.

2-2. Positive electrode <Positive electrode active material>
The positive electrode active material (lithium transition metal compound) used for the positive electrode is described below.
<Lithium transition metal compound>
A lithium transition metal compound is a compound having a structure capable of desorbing and inserting Li ions, and examples thereof include sulfides, phosphate compounds, and lithium transition metal composite oxides. Examples of sulfides include compounds having a two-dimensional layered structure such as TiS ₂ and MoS ₂ , and strong compounds represented by the general formula Me _x Mo ₆ S ₈ (Me is various transition metals including Pb, Ag, and Cu). Examples thereof include a sugar compound having a three-dimensional skeleton structure. Examples of the phosphate compound include those belonging to the olivine structure, and are generally represented by LiMePO ₄ (Me is at least one or more transition metals), specifically LiFePO ₄ , LiCoPO ₄ , LiNiPO ₄ , Examples include LiMnPO ₄ . Examples of the lithium transition metal composite oxide include spinel structures capable of three-dimensional diffusion and those belonging to a layered structure capable of two-dimensional diffusion of lithium ions. Those having a spinel structure are generally expressed as LiMe ₂ O ₄ (Me is at least one transition metal), specifically, LiMn ₂ O ₄ , LiCoMnO ₄ , LiNi _0.5 Mn _1.5 O. ₄ , LiCoVO _{4 and the} like. Those having a layered structure are generally expressed as LiMeO ₂ (Me is at least one transition metal). LiCoO _{2 Specifically, LiNiO 2, LiNi 1-x} Co x O 2, LiNi 1-x-y Co x Mn y O 2, LiNi 0.5 Mn 0.5 O 2, Li 1.2 Cr 0. _{4 Mn 0.4 O 2, Li 1.2} Cr 0.4 Ti 0.4 O 2, such as LiMnO ₂ and the like.

<composition>
The lithium-containing transition metal compound is, for example, a lithium transition metal compound represented by the following composition formula (A) or (B).
1) In the case of a lithium transition metal compound represented by the following composition formula (A)
Li _{1 + x} MO ₂ (A)
However, x is usually 0 or more and 0.5 or less. M is an element composed of Ni and Mn or Ni, Mn and Co, and the Mn / Ni molar ratio is usually 0.1 or more and 5 or less. The Ni / M molar ratio is usually 0 or more and 0.5 or less. The Co / M molar ratio is usually 0 or more and 0.5 or less. In addition, the rich portion of Li represented by x may be replaced with the transition metal site M.

  In the composition formula (A), the atomic ratio of the oxygen amount is described as 2 for convenience, but there may be some non-stoichiometry. Moreover, x in the said compositional formula is the preparation composition in the manufacture stage of a lithium transition metal type compound. Usually, batteries on the market are aged after the batteries are assembled. For this reason, the Li amount of the positive electrode may be deficient with charge / discharge. In this case, x may be measured to be −0.65 or more and 1 or less when discharged to 3 V in composition analysis.

A lithium transition metal-based compound is excellent in battery characteristics when fired at a high temperature in an oxygen-containing gas atmosphere in order to enhance the crystallinity of the positive electrode active material.
Further, the lithium transition metal-based compound represented by the composition formula (A) may be a solid solution with Li ₂ MO ₃ called a 213 layer, as shown in the general formula (A ′) below.
αLi ₂ MO ₃ · (1-α) LiM′O ₂ (A ′)
In the general formula, α is a number satisfying 0 <α <1.

M is at least one metallic element average oxidation number of 4 ^+, specifically, at least one metal element Mn, Zr, Ti, Ru, selected from the group consisting of Re and Pt.
M 'is at least one metallic element average oxidation number of 3 ^+, preferably, V, Mn, Fe, at least one metallic element selected from the group consisting of Co and Ni, more preferably , At least one metal element selected from the group consisting of Mn, Co and Ni.

2) A lithium transition metal compound represented by the following general formula (B).
_{Li [Li a M b Mn 2} -b-a] O 4 + δ ··· (B)
However, M is an element comprised from at least 1 sort (s) of the transition metals chosen from Ni, Cr, Fe, Co, Cu, Zr, Al, and Mg.
The value of b is usually 0.4 or more and 0.6 or less.

If the value of b is this range, the energy density per unit mass in a lithium transition metal type compound will be high.
The value of a is usually 0 or more and 0.3 or less. Moreover, a in the above composition formula is a charged composition in the production stage of the lithium transition metal compound. Usually, batteries on the market are aged after the batteries are assembled. For this reason, the Li amount of the positive electrode may be deficient with charge / discharge. In this case, a may be measured to be −0.65 or more and 1 or less when discharged to 3 V in composition analysis.

When the value of a is within this range, the energy density per unit mass in the lithium transition metal compound is not significantly impaired, and good load characteristics can be obtained.
Furthermore, the value of δ is usually in the range of ± 0.5.
If the value of δ is within this range, the stability as a crystal structure is high, and the cycle characteristics and high-temperature storage of a battery having an electrode produced using this lithium transition metal compound are good.

Here, the chemical meaning of the lithium composition in the lithium nickel manganese composite oxide, which is the composition of the lithium transition metal compound, will be described in more detail below.
In order to obtain a and b in the composition formula of the lithium transition metal compound, each transition metal and lithium are analyzed with an inductively coupled plasma emission spectrometer (ICP-AES) to obtain a ratio of Li / Ni / Mn. It is calculated by the thing.

From a structural point of view, it is considered that lithium related to a is substituted for the same transition metal site. Here, due to the lithium according to a, the average valence of M and manganese becomes larger than 3.5 due to the principle of charge neutrality.
Further, the lithium transition metal based compound may be substituted with fluorine, it is expressed as _{LiMn 2 O 4-x F 2x} .

<blend>
Specific examples of the lithium transition metal compound having the above composition include, for example, Li _{1 + x} Ni _0.5 Mn _0.5 O ₂ , Li _{1 + x} Ni _0.85 Co _0.10 Al _0.05 O ₂ , Li _{1 + x} Ni _0.33 Mn _0.33 Co _0.33 O ₂ , Li _{1 + x} Ni _0.45 Mn _0.45 Co _0.1 O ₂ , Li _{1 + x} Mn _1.8 Al _0.2 O ₄ , Li _{1 + x} Mn _1.5 Ni _0.5 O ₄ and the like. These lithium transition metal compounds may be used alone or in a blend of two or more.

<Introduction of foreign elements>
Moreover, a different element may be introduce | transduced into a lithium transition metal type compound. As a foreign element, B
, Na, Mg, Al, K, Ca, Ti, V, Cr, Fe, Cu, Zn, Sr, Y, Zr, Nb, Ru, Rh, Pd, Ag, In, Sb, Te, Ba, Ta, Mo , W, Re, Os, Ir, Pt, Au, Pb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Bi, N, F, S , Cl, Br, I, As, Ge, P, Pb, Sb, Si, and Sn. These foreign elements may be incorporated into the crystal structure of the lithium transition metal compound, or may not be incorporated into the crystal structure of the lithium transition metal compound, and may be a single element or compound on the particle surface or grain boundary. May be unevenly distributed.

[Positive electrode for lithium secondary battery]
The positive electrode for a lithium secondary battery is formed by forming a positive electrode active material layer containing the above-described lithium transition metal compound powder for a lithium secondary battery positive electrode material and a binder on a current collector.
The positive electrode active material layer is usually formed by mixing a positive electrode material, a binder, and a conductive material and a thickener, which are used if necessary, in a dry form into a sheet shape, and then pressing the positive electrode current collector on the positive electrode current collector. Alternatively, these materials are dissolved or dispersed in a liquid medium to form a slurry, which is applied to the positive electrode current collector and dried.

  As the material for the positive electrode current collector, metal materials such as aluminum, stainless steel, nickel plating, titanium, and tantalum, and carbon materials such as carbon cloth and carbon paper are usually used. As for the shape, in the case of a metal material, a metal foil, a metal cylinder, a metal coil, a metal plate, a metal thin film, an expanded metal, a punch metal, a foam metal, etc., and in the case of a carbon material, a carbon plate, a carbon thin film, a carbon cylinder Etc. In addition, you may form a thin film suitably in mesh shape.

  When a thin film is used as the positive electrode current collector, its thickness is arbitrary, but a range of usually 1 μm or more and 100 mm or less is suitable. If it is thinner than the above range, the strength required for the current collector may be insufficient. On the other hand, if it is thicker than the above range, the handleability may be impaired.

  The binder used in the production of the positive electrode active material layer is not particularly limited, and in the case of a coating method, any material that is stable with respect to the liquid medium used during electrode production may be used. Specific examples include polyethylene, Resin polymers such as polypropylene, polyethylene terephthalate, polymethyl methacrylate, aromatic polyamide, cellulose, nitrocellulose, SBR (styrene butadiene rubber), NBR (acrylonitrile butadiene rubber), fluorine rubber, isoprene rubber, butadiene rubber, ethylene・ Rubber polymers such as propylene rubber, styrene / butadiene / styrene block copolymers and hydrogenated products thereof, EPDM (ethylene / propylene / diene terpolymers), styrene / ethylene / butadiene / ethylene copolymers, Styrene / isoprene styrene bromide Copolymer and its hydrogenated thermoplastic elastomeric polymer, syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene / vinyl acetate copolymer, propylene / α-olefin copolymer, etc. Fluorine polymers such as soft resinous polymers, polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene fluoride, polytetrafluoroethylene / ethylene copolymers, ion conductivity of alkali metal ions (especially lithium ions) And a polymer composition having the same. In addition, these substances may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

The ratio of the binder in the positive electrode active material layer is usually 0.1% by mass or more and 80% by mass or less. If the proportion of the binder is too low, the positive electrode active material cannot be sufficiently retained and the positive electrode has insufficient mechanical strength, which may deteriorate battery performance such as cycle characteristics. Battery capacity and conductivity may be reduced.
The positive electrode active material layer usually contains a conductive material in order to increase conductivity. There are no particular restrictions on the type, but specific examples include metal materials such as copper and nickel, graphite such as natural graphite and artificial graphite, carbon black such as acetylene black, and amorphous carbon such as needle coke. And carbon materials. In addition, these substances may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios. The proportion of the conductive material in the positive electrode active material layer is usually 0.01% by mass or more and 50% by mass or less. If the proportion of the conductive material is too low, the conductivity may be insufficient, and conversely if it is too high, the battery capacity may be reduced.

  As a liquid medium for forming a slurry, it is possible to dissolve or disperse a lithium transition metal compound powder as a positive electrode material, a binder, and a conductive material and a thickener used as necessary. If it is a solvent, there is no restriction | limiting in particular in the kind, You may use either an aqueous solvent or an organic solvent. Examples of the aqueous solvent include water and alcohol. Examples of the organic solvent include N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, N , N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran (THF), toluene, acetone, dimethyl ether, dimethylacetamide, hexamethylphosphalamide, dimethyl sulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, hexane, etc. be able to. In particular, when an aqueous solvent is used, a dispersant is added together with the thickener, and a slurry such as SBR is slurried. In addition, these solvents may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

The content ratio of the lithium transition metal-based compound powder as the positive electrode material in the positive electrode active material layer is usually 10% by mass or more and 99.9% by mass or less. If the proportion of the lithium transition metal compound powder in the positive electrode active material layer is too large, the strength of the positive electrode tends to be insufficient, and if it is too small, the capacity may be insufficient.
The thickness of the positive electrode active material layer is usually about 10 to 200 μm.

The electrode density after pressing the positive electrode is usually 2.2 g / cm ³ or more and 4.2 g / cm ³ or less.
The positive electrode active material layer obtained by coating and drying is preferably consolidated by a roller press or the like in order to increase the packing density of the positive electrode active material.
Thus, a positive electrode for a lithium secondary battery can be prepared.

2-3. Separator Normally, a separator is interposed between the positive electrode and the negative electrode in order to prevent a short circuit. In this case, the nonaqueous electrolytic solution of the present invention is usually used by impregnating the separator.
The material and shape of the separator are not particularly limited, and known ones can be arbitrarily adopted as long as the effects of the present invention are not significantly impaired. Among them, a resin, glass fiber, inorganic material, etc. formed of a material that is stable with respect to the non-aqueous electrolyte solution of the present invention is used, and a porous sheet or a nonwoven fabric-like material having excellent liquid retention properties is used. Is preferred.

  As materials for the resin and glass fiber separator, for example, polyolefins such as polyethylene and polypropylene, aromatic polyamides, polytetrafluoroethylene, polyethersulfone, glass filters and the like can be used. Of these, glass filters and polyolefins are preferred, and polyolefins are more preferred. These materials may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

The thickness of the separator is arbitrary, but is usually 1 μm or more, preferably 5 μm or more.
It is more preferably 0 μm or more, usually 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less. If the separator is too thin than the above range, the insulating properties and mechanical strength may decrease. On the other hand, if it is thicker than the above range, not only the battery performance such as the rate characteristic may be lowered, but also the energy density of the whole non-aqueous electrolyte secondary battery may be lowered.

  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. If the porosity is too smaller than the above range, the membrane resistance tends to increase and the rate characteristics tend to deteriorate. Moreover, when larger than the said range, it exists in the tendency for the mechanical strength of a separator to fall and for insulation to fall.

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. On the other hand, below the above range, the film resistance may increase and the rate characteristics may deteriorate.
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.

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

  The characteristics of the separator in the non-electrolyte secondary battery can be grasped by the Gurley value. The Gurley value indicates the difficulty of air passage in the film thickness direction, and is expressed as the number of seconds required for 100 ml of air to pass through the film. It means that it is harder to go through. That is, a smaller value means better communication in the thickness direction of the film, and a larger value means lower communication in the thickness direction of the film. Communication is the degree of connection of holes in the film thickness direction. If the Gurley value of the separator of the present invention is low, it can be used for various purposes. For example, when used as a separator for a non-aqueous lithium secondary battery, a low Gurley value means that lithium ions can be easily transferred and is preferable because of excellent battery performance. Although the Gurley value of a separator is arbitrary, Preferably it is 10-1000 second / 100ml, More preferably, it is 15-800 second / 100ml, More preferably, it is 20-500 second / 100ml. If the Gurley value is 1000 seconds / 100 ml or less, the electrical resistance is substantially low, which is preferable as a separator.

2-4. Battery design <Electrode group>
The electrode group has a laminated structure in which the positive electrode plate and the negative electrode plate are interposed through the separator, and a structure in which the positive electrode plate and the negative electrode plate are wound in a spiral shape through the separator. Either is acceptable. The ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as the electrode group occupation ratio) is usually 40% or more, preferably 50% or more, and usually 90% or less, preferably 80% or less. .

  When the electrode group occupancy is below the above range, the battery capacity decreases. In addition, if the above range is exceeded, there is less void space, the battery expands, and the member expands or the vapor pressure of the liquid component of the electrolyte increases and the internal pressure rises, and the charge / discharge cycle performance as a battery In some cases, the gas release valve that lowers various characteristics such as storage at high temperature and the like, or releases the internal pressure to the outside is activated.

<Exterior case>
The material of the outer case is not particularly limited as long as it is a substance that is stable with respect to the non-aqueous electrolyte used. Specifically, a nickel-plated steel plate, stainless steel, aluminum, an aluminum alloy, a metal such as a magnesium alloy, or a laminated film (laminate film) of a resin and an aluminum foil is used. From the viewpoint of weight reduction, an aluminum or aluminum alloy metal or a laminate film is preferably used.

  In an exterior case using metals, the metal is welded together by laser welding, resistance welding, or ultrasonic welding to form a sealed sealed structure, or a caulking structure using the above metals via a resin gasket. Things. Examples of the outer case using the laminate film include a case where a resin-sealed structure is formed by heat-sealing resin layers. In order to improve sealing performance, 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 through a current collecting terminal to form a sealed structure, a metal and a resin are joined, so that a resin having a polar group or a modified group having a polar group introduced as an intervening resin is used. Resins are preferably used.

<Protective element>
Protection elements such as PTC (Positive Temperature Coefficient), thermal fuse, thermistor, which increases resistance when abnormal heat is generated or excessive current flows, shuts off current flowing through the circuit due to sudden increase in battery internal pressure or internal temperature during abnormal heat generation A valve (current cutoff valve) or the like can be used. It is preferable to select a protective element that does not operate under normal use at a high current, and it is more preferable that the protective element is designed so as not to cause abnormal heat generation or thermal runaway even without the protective element.

(Exterior body)
The non-aqueous electrolyte secondary battery of the present invention is usually configured by housing the non-aqueous electrolyte, the negative electrode, the positive electrode, the separator, and the like in an exterior body (exterior case). There is no restriction | limiting in this exterior body, As long as the effect of this invention is not impaired remarkably, a well-known thing can be employ | adopted arbitrarily.
The material of the outer case is not particularly limited as long as it is a substance that is stable with respect to the non-aqueous electrolyte used. Specifically, a nickel-plated steel plate, stainless steel, aluminum or an aluminum alloy, a magnesium alloy, nickel, titanium, or a metal, or a laminated film (laminate film) of a resin and an aluminum foil is used. From the viewpoint of weight reduction, an aluminum or aluminum alloy metal or a laminate film is preferably used.

In the outer case using the above metals, the metal is welded to each other by laser welding, resistance welding, ultrasonic welding, or a sealed sealing structure, or a caulking structure using the above metals through a resin gasket To do. Examples of the outer case using the laminate film include a case where a resin-sealed structure is formed by heat-sealing resin layers. In order to improve sealing performance, 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 through a current collecting terminal to form a sealed structure, a metal and a resin are joined, so that a resin having a polar group or a modified group having a polar group introduced as an intervening resin is used. Resins are preferably used.
The shape of the outer case is also arbitrary, and may be any of a cylindrical shape, a square shape, a laminate shape, a coin shape, a large size, and the like.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.
The structure of the compound containing the structure represented by the general formula (A) used in this example is shown below.

  The structure of the halogenated cyclic carbonate compound used in this example is shown below.

  The structure of the isocyanate compound used in this example is shown below.

  The structure of the acid anhydride compound used in this example is shown below.

5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride The structure of the difluorophosphate used in this example is shown below.

  The structure of the monofluorosulfonate used in this example is shown below.

<Examples 2-1 to 2-6, Comparative Examples 2-1 to 2-6>
[Production of positive electrode]
94% by mass of lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, 3% by mass of acetylene black as a conductive material, and 3% by mass of polyvinylidene fluoride (PVdF) as a binder, in an N-methylpyrrolidone solvent, The slurry was mixed 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.

[Preparation of negative electrode]
8 parts by weight of polyimide as a binder was added to 89 parts by mass of silicon powder as a negative electrode active material and 3 parts by mass of graphite powder, and mixed with a disperser in an NMP solution to form a slurry. The obtained slurry was applied to both sides of a copper foil, dried by heating, pressed, cut into a 30 mm × 40 mm rectangle and used. The produced negative electrode was used after drying under reduced pressure at 60 ° C. for 12 hours.

[Manufacture of non-aqueous electrolyte batteries (laminate type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, and the positive electrode. The battery element thus obtained was wrapped in an aluminum laminate film, injected with an electrolyte solution described later, and then vacuum sealed to produce a sheet-like non-aqueous electrolyte secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[High-temperature cycle test]
In a constant temperature bath at 25 ° C., a non-aqueous electrolyte secondary battery of a coin-type cell was charged at a constant current for 4 hours at a current corresponding to 0.05 C (hereinafter referred to as “CC charging” as appropriate), and then 4 at 0.2 C. Constant current-constant voltage charging (hereinafter referred to as “CC-CV charging” as appropriate) up to 0.0 V was performed. Then, it discharged to 2.75V at 0.2C. Subsequently, after CC-CV to 4.0 V at 0.2 C, the battery was discharged to 2.75 V at 0.2 C to stabilize the non-aqueous electrolyte secondary battery. Then, after performing CC-CV charge to 4.2V at 0.2C, it discharged to 2.75V at 0.2C and performed the initial conditioning.
The cell after the initial conditioning was subjected to 200 cycles in a thermostatic bath at 45 ° C., with CCCV charging to 4.2 V at 0.5 C and then discharging to 2.75 V at a constant current of 0.5 C as one cycle. The capacity at the 200th cycle was defined as “capacity after 200 cycles”.

[Example 2-1]
Under a dry argon atmosphere, 1 mol / L (as a concentration in the non-aqueous electrolyte) of LiPF ₆ sufficiently dried was dissolved in a mixture of the compound (2) and EMC (volume ratio 2: 8). The fully dried compound (1) was dissolved in an amount of 0.5% by mass (as a concentration in the non-aqueous electrolyte solution) to prepare a non-aqueous electrolyte solution. Using this non-aqueous electrolyte solution, a battery was produced by the method described above, and the above evaluation was performed.

[Example 2-2]
Under a dry argon atmosphere, 1 mol / L (as a concentration in the non-aqueous electrolyte) of LiPF ₆ sufficiently dried was dissolved in a mixture of the compound (2) and EMC (volume ratio 2: 8). 0.25% by mass of the sufficiently dried compound (1) (as the concentration in the non-aqueous electrolyte) and 0.25% by mass (as the concentration in the non-aqueous electrolyte) of the sufficiently dried compound (3) ) Dissolved to prepare a non-aqueous electrolyte solution. Using this non-aqueous electrolyte solution, a battery was produced by the method described above, and the above evaluation was performed.

[Example 2-3]
A battery was prepared in the same manner as in Example 2-2 except that the compound (4) was dissolved in the nonaqueous electrolytic solution instead of the compound (3), and the above evaluation was performed.
[Example 2-4]
A battery was prepared in the same manner as in Example 2-2 except that the compound (5) was dissolved in the nonaqueous electrolytic solution instead of the compound (3), and the above evaluation was performed.

[Example 2-5]
A battery was prepared in the same manner as in Example 2-2 except that the compound (6) was dissolved in the nonaqueous electrolytic solution instead of the compound (3), and the above evaluation was performed.
[Example 2-6]
A battery was produced in the same manner as in Example 2-2 except that the compound (7) was dissolved in the nonaqueous electrolytic solution instead of the compound (3), and the above evaluation was performed.

[Comparative Example 2-1]
A battery was produced in the same manner as in Example 2-1, except that the compound (1) was not dissolved in the nonaqueous electrolytic solution, and the above evaluation was performed.
[Comparative Example 2-2]
A battery was produced in the same manner as in Example 2-3 except that the compound (1) was not dissolved in the nonaqueous electrolytic solution, and the above evaluation was performed.

[Comparative Example 2-3]
A battery was prepared in the same manner as in Example 2-5 except that the compound (1) was not dissolved in the nonaqueous electrolytic solution, and the above evaluation was performed.
[Comparative Example 2-4]
A battery was prepared in the same manner as in Example 2-6 except that the compound (1) was not dissolved in the nonaqueous electrolytic solution, and the above evaluation was performed.

[Comparative Example 2-5]
A battery was produced in the same manner as in Example 2-7 except that the compound (1) was not dissolved in the nonaqueous electrolytic solution, and the above evaluation was performed.
[Comparative Example 2-6]
A battery was prepared in the same manner as in Example 2-8 except that the compound (1) was not dissolved in the nonaqueous electrolytic solution, and the above evaluation was performed.
Table 1 below shows the capacity after 200 cycles normalized by the value of Comparative Example 2-1.

  Comparing Comparative Example 2-1 and Example 2-1, the compound (1) and the compound (2) were added because the discharge capacity at 200 cycles was 2.5 times by adding the compound (1). It can be seen that the cycle characteristics are improved by co-adding) to the electrolyte. Further, the cycle characteristics are improved by combining with the compound (1) rather than adding each compound alone (Comparative Examples 2-2 to 2-6).

According to the non-aqueous electrolyte solution of the present invention, capacity deterioration and cycle characteristics of a non-aqueous electrolyte battery during high temperature storage can be improved. Therefore, it can be suitably used in all fields such as an electronic device in which a non-aqueous electrolyte secondary battery is used.
The application of the non-aqueous electrolyte solution and the non-aqueous electrolyte secondary battery of the present invention is not particularly limited, and can be used for various known applications. Specific examples of applications include laptop computers, electronic book players, mobile phones, mobile faxes, mobile copy, mobile printers, mobile audio players, small video cameras, LCD TVs, handy cleaners, transceivers, electronic notebooks, calculators, and memories. Cards, portable tape recorders, radios, backup power supplies, automobiles, motorcycles, motorbikes, bicycles, lighting equipment, toys, game machines, watches, electric tools, strobes, cameras, etc.

Claims (10)

A non-aqueous electrolyte solution for a non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of occluding and releasing metal ions, the non-aqueous electrolyte solution being represented by the following general formula (B) together with an electrolyte and a non-aqueous solvent containing structural as well as halogenated cyclic carbonate compound, the non-aqueous electrolyte, she characterized in that it contains at least one compound selected from the group consisting of di-fluorophosphate and monofluorophosphate sulfonate.

(In Formula (B), R _{1 to} R ₃ may be the same as or different from each other and have 1 to 2 carbon atoms.
It is an organic group which may have 0 substituents. ) Nonaqueous electrolytic solution according to claim 1, wherein In Formula (B), at least one of R ₁ to R ₃ is equal to or an allyl group. Nonaqueous electrolytic solution according to claim 1 or 2, wherein the halogenated cyclic carbonate compound, characterized in that a fluorinated cyclic carbonate. According to claim 3, wherein the fluorinated cyclic carbonate, characterized in that at least one compound selected from the group consisting of mono-fluoroethylene carbonate, 4,4-difluoroethylene carbonate and 4,5-difluoroethylene carbonate Non-aqueous electrolyte. The addition amount of the compound containing the structure represented by the general formula (B) is 0.01% by mass or more and 10.0% by mass or less with respect to the total amount of the nonaqueous electrolytic solution. The non-aqueous electrolyte solution as described in any one of thru | or 4 . The amount of the halogenated cyclic carbonate compound is any one of claims 3 to 5, characterized in that the total amount of the nonaqueous electrolytic solution is less than 20.0 vol% 0.01 vol% The non-aqueous electrolyte solution described in 1. The non-aqueous electrolyte is at least selected from the group consisting of a cyclic carbonate having a carbon-carbon unsaturated bond, an acid anhydride, a compound having an isocyanuric acid skeleton, a vinyl sulfonate compound, and an aromatic compound having 12 or less carbon atoms. The nonaqueous electrolytic solution according to any one of claims 1 to 6 , comprising one kind of compound. And capable of absorbing and desorbing lithium ions cathode, a lithium ion and capable of absorbing and desorbing negative electrode, the nonaqueous electrolyte secondary battery comprising a nonaqueous electrolyte solution, nonaqueous electrolyte solution, according to claim 1 to 7 A nonaqueous electrolyte battery characterized by being a nonaqueous electrolyte solution according to any one of the above. The non-aqueous electrolyte battery according to claim 8 , wherein the negative electrode active material of the negative electrode capable of occluding and releasing lithium ions has carbon as a constituent element. The non-aqueous electrolyte battery according to claim 8 , wherein the negative electrode active material of the negative electrode capable of inserting and extracting lithium ions has silicon (Si) or tin (Sn) as a constituent element.