JP4910338B2 - Non-aqueous electrolyte and non-aqueous electrolyte battery - Google Patents

Description

The present invention relates to a non-aqueous electrolyte and a non-aqueous electrolyte battery using the same, and more particularly to a non-aqueous electrolyte secondary battery.
More specifically, the present invention relates to a non-aqueous electrolyte battery having a high capacity, excellent storage characteristics and cycle characteristics, and a small amount of gas generation.

Non-aqueous electrolyte batteries such as lithium secondary batteries are being put to practical use in a wide range of applications from so-called consumer power sources such as mobile phones and laptop computers to in-vehicle power sources for automobiles and the like. However, the demand for higher performance of non-aqueous electrolyte batteries in recent years is increasing, and there is a demand for improvement in battery characteristics.
The electrolyte used for a non-aqueous electrolyte battery is usually composed mainly of an electrolyte and a non-aqueous solvent. As main components of the non-aqueous solvent, cyclic carbonates such as ethylene carbonate and propylene carbonate; chain carbonates such as dimethyl carbonate and ethyl methyl carbonate; cyclic carboxylic acid esters such as γ-butyrolactone and γ-valerolactone are used. Yes.

In addition, in order to improve battery characteristics such as load characteristics, cycle characteristics, storage characteristics, and low temperature characteristics of such nonaqueous electrolyte batteries, various studies have been made on nonaqueous solvents and electrolytes.
For example, an electrolyte solution for a lithium secondary battery containing an alkyl alkanesulfonate is known. (See Patent Document 1).
In addition, a nonaqueous electrolytic solution containing a disulfonic acid ester is known (see Patent Document 2).
Japanese Patent Laid-Open No. 9-245834 JP 2000-133304 A

However, the demand for higher performance of batteries in recent years has been increasing, and it is required to achieve high capacity, high temperature storage characteristics, and cycle characteristics at a high level.
Therefore, as a method for increasing the capacity of a non-aqueous electrolyte battery, it has been studied to pack as many active materials as possible in a limited battery volume. In general, the design is such that the volume other than the active material in the battery is minimized. However, there is a problem that the voids inside the battery are reduced due to the increase in capacity, and even if a small amount of gas is generated due to the decomposition of the electrolyte, the internal pressure of the battery is significantly increased.

If a large amount of gas is generated, a safety valve may be activated in a battery that senses this when the internal pressure is abnormally increased due to an abnormality such as overcharge and activates the safety valve. Further, in a battery without a safety valve, the battery may expand due to the pressure of the generated gas, and the battery itself may become unusable.
Therefore, non-aqueous electrolyte secondary batteries are strongly required to suppress gas generation as well as high capacity, high temperature storage characteristics, and cycle characteristics.

  However, the non-aqueous electrolyte secondary batteries using the electrolytes described in Patent Documents 1 and 2 have not yet been satisfactory in terms of achieving both high-temperature storage characteristics and suppression of gas generation.

  As a result of various investigations for an electrolyte solution that suppresses gas generation and also improves high-temperature storage characteristics while maintaining high cycle characteristics, the present inventors have conducted various studies and found that a sulfonate structure and an ether bond are present in the molecule. By using a non-aqueous electrolyte solution containing a compound represented by the following general formula (1) and / or (2) having a gas generation and capacity reduction during high-temperature storage while maintaining high cycle characteristics Has been found to be suppressed, and the present invention has been completed.

  That is, the gist of the present invention is that in a non-aqueous electrolyte solution containing an electrolyte and a non-aqueous solvent for dissolving the electrolyte, the non-aqueous electrolyte solution contains a compound represented by the following general formula (1) and / or (2). The non-aqueous electrolyte solution is characterized by that.

(In the formula, R ₁ , R ₂ , R ₃ and R ₅ are each independently an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or carbon. Represents an aralkyl group of 7 to 12, and may have an ether bond in the structure, provided that R ₁ or R ₂ includes at least one ether bond, and R ₄ represents a carbon number including an ether bond. Represents a divalent linking group of 2 to 12. In addition, R _{1 to} R ₅ may each independently be substituted with a fluorine atom, among the compounds represented by the general formula (1) . And R ₁ is a vinyl group, R ₁ is a group containing a vinyloxy group, and R ₂ is a group containing a vinyloxy group.
Another gist is a non-aqueous electrolyte battery including a negative electrode and a positive electrode capable of inserting and extracting lithium ions, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte battery is manufactured using the non-aqueous electrolyte solution described above. It exists in the non-aqueous electrolyte battery characterized by the above-mentioned.

  According to the present invention, it is possible to provide a battery with high capacity, excellent storage characteristics and cycle characteristics, and suppressed gas generation, and it is possible to achieve downsizing and high performance of a non-aqueous electrolyte battery. .

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. However, the description of constituent elements described below is an example (representative example) of an embodiment of the present invention, and is not specified by these contents.
The non-aqueous electrolyte solution according to the present invention contains an electrolyte and a non-aqueous solvent that dissolves the electrolyte, as is the case with conventional non-aqueous electrolyte solutions, and usually contains these as the main components.
(Electrolytes)
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, inorganic lithium salts such as LiPF ₆ and LiBF ₄ ; LiCF ₃ SO ₃ , 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, LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ), LiC (CF ₃ SO ₂ ) ₃ , LiPF ₄ (CF ₃ ) ₂ , Li
PF ₄ (C ₂ F ₅ ) ₂ , LiPF ₄ (CF ₃ SO ₂ ) ₂ , LiPF ₄ (C ₂ F ₅ SO ₂ ) ₂ , 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 S
And fluorine-containing organic lithium salts such as O ₂ ) ₂ and lithium bis (oxalate) borate.

Of these, LiPF ₆ , LiBF ₄ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ or LiN (C ₂ F ₅ SO ₂ ) ₂ are preferable, and LiPF ₆ or LiBF ₄ is particularly preferable.
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 kinds in combination is the combined use of LiPF ₆ and LiBF _{4. In} this case, the proportion of LiBF _{4 in} the total of both is 0.01 wt% or more, 20 wt%.
The content is preferably 0.1% by weight or more and particularly preferably 5% by weight or less.

Another example is the combined use of an inorganic lithium salt and a fluorine-containing organic lithium salt. In this case, the proportion of the inorganic lithium salt in the total of both is 70% by weight or more and 99% by weight or less. It is desirable. Examples of the fluorine-containing organic lithium salt include LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropane. It is preferably any of disulfonylimide. The combined use of both has the effect of suppressing deterioration due to high temperature storage.

When the non-aqueous solvent contains 55% by volume or more of γ-butyrolactone, the lithium salt is preferably LiBF ₄ or a combination of LiBF ₄ and another. In this case, LiBF ₄ preferably accounts for 40 mol% or more of the lithium salt. Particularly preferably, the proportion of LiBF _{4 in} the lithium salt is 40 mol% or more and 95 mol% or less, and the rest is Li
The combination is selected from the group consisting of PF ₆ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ and LiN (C ₂ F ₅ SO ₂ ) ₂ .

  The concentration of the lithium salt in the non-aqueous electrolyte is usually 0.5 mol / liter or more and 3 mol / liter or less. If the concentration is too low, the electric conductivity of the electrolytic solution is insufficient. If the concentration is too high, the viscosity increases and the electric conductivity is lowered, and the battery performance may be lowered. The concentration of the lithium salt in the non-aqueous electrolyte is preferably 0.6 mol / liter or more, and is preferably 1.8 mol / liter or less, particularly preferably 1.5 mol / liter or less.

(Non-aqueous solvent)
The non-aqueous solvent can also be appropriately selected from conventionally known solvents for non-aqueous electrolyte solutions. Examples thereof include cyclic carbonates having no unsaturated bond, chain carbonates, cyclic ethers, chain ethers, cyclic carboxylic acid esters, chain carboxylic acid esters, and phosphorus-containing organic solvents.

Examples of the cyclic carbonates having no unsaturated bond include alkylene carbonates having an alkylene group having 2 to 4 carbon atoms such as ethylene carbonate, propylene carbonate, and butylene carbonate. Among these, ethylene carbonate, propylene carbonate, and the like. And ethylene carbonate is particularly preferable.
Examples of the chain carbonates include dialkyl having an alkyl group having 1 to 4 carbon atoms such as dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, ethyl methyl carbonate, methyl-n-propyl carbonate, and ethyl-n-propyl carbonate. And carbonates. Among these, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are preferable.

Examples of cyclic ethers include tetrahydrofuran and 2-methyltetrahydrofuran.
Examples of chain ethers include dimethoxyethane and dimethoxymethane.
Examples of cyclic carboxylic acid esters include γ-butyrolactone and γ-valerolactone.

Examples of chain carboxylic acid esters include methyl acetate, methyl propionate, ethyl propionate, and methyl butyrate.
Examples of the phosphorus-containing organic solvent include trimethyl phosphate, triethyl phosphate, dimethyl ethyl phosphate, methyl diethyl phosphate, ethylene methyl phosphate, ethylene ethyl phosphate, and the like.

These may be used alone or in combination of two or more, but it is preferable to use in combination of two or more. For example, high dielectric constant solvents having a relative dielectric constant of about 30 to 120 such as alkylene carbonates and cyclic carboxylic acid esters, and low viscosities of dialkyl carbonates and chain carboxylic acid esters of about 0.1 to 1 cp. It is preferable to use a viscosity solvent in combination.
One preferable combination of the non-aqueous solvents is a combination mainly composed of alkylene carbonates and dialkyl carbonates. Among them, the total of alkylene carbonates and dialkyl carbonates in the nonaqueous solvent is 85% by volume or more, preferably 90% by volume or more, more preferably 95% by volume or more, and the alkylene carbonates and dialkyl carbonates. The amount of alkylene carbonate with respect to the sum of the above is 5% or more, preferably 10% or more, more preferably 15% or more, usually 50% or less, preferably 35% or less, more preferably 30% or less, and still more preferably 25%. % Or less. The non-aqueous electrolyte obtained by adding the lithium salt and the compound represented by the general formula (1) and / or (2) to this mixed solvent has a cycle characteristic and a high temperature of a battery prepared using the non-aqueous electrolyte. This is preferable because the balance between storage characteristics (particularly, remaining capacity after high temperature storage and high load discharge capacity) and gas generation suppression is improved.

  Specific examples of preferred combinations of alkylene carbonates and dialkyl carbonates include ethylene carbonate and dimethyl carbonate, ethylene carbonate and diethyl carbonate, ethylene carbonate and ethyl methyl carbonate, ethylene carbonate and dimethyl carbonate and diethyl carbonate, ethylene carbonate and dimethyl carbonate, Examples include ethyl methyl carbonate, ethylene carbonate, diethyl carbonate, and ethyl methyl carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate.

A combination in which propylene carbonate is further added to a combination of these ethylene carbonate and dialkyl carbonates is also mentioned as a preferable combination.
When propylene carbonate is contained, the volume ratio of ethylene carbonate to propylene carbonate is usually 99: 1 to 40:60, preferably 95: 5 to 50:50.

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

  Other examples of preferable non-aqueous solvents include one organic solvent selected from the group consisting of ethylene carbonate, propylene carbonate, γ-butyrolactone and γ-valerolactone, or two or more organic solvents selected from the group The mixed solvent becomes 60% by volume or more of the whole. The non-aqueous electrolyte using this mixed solvent is less likely to evaporate or leak when used at high temperatures. Among these, the total of ethylene carbonate and γ-butyrolactone in the nonaqueous solvent is 80% by volume or more, preferably 90% by volume or more, and the volume ratio of ethylene carbonate and γ-butyrolactone is 5:95 to 45%. : 55, or the total of ethylene carbonate and propylene carbonate in the non-aqueous solvent is 80% by volume or more, preferably 90% by volume or more, and the volume ratio of ethylene carbonate to propylene carbonate is 30:70 to Use of a material having a ratio of 60:40 generally improves the balance between cycle characteristics and large current discharge characteristics.

  It is also preferable to use a phosphorus-containing organic solvent as the non-aqueous solvent. When the phosphorus-containing organic solvent is contained in the non-aqueous solvent so that it is usually 5% by volume or more, preferably 10% by volume or more and 80% by volume or less, the flammability of the electrolyte can be lowered. In particular, when a phosphorus-containing organic solvent is used in combination with a nonaqueous solvent selected from the group consisting of ethylene carbonate, propylene carbonate, γ-butyrolactone, γ-valerolactone, and dialkyl carbonate, cycle characteristics and large current discharge characteristics This is preferable because the balance is improved.

In the present specification, the capacity of the non-aqueous solvent is a measured value at 25 ° C., but a measured value at the melting point is used for a solid at 25 ° C. such as ethylene carbonate.
(Compound represented by formula (1) or (2))
The nonaqueous electrolytic solution according to the present invention contains the above-described electrolyte and a nonaqueous solvent, and further contains a compound represented by the following general formula (1) and / or (2).

(In the formula, R ₁ , R ₂ , R ₃ and R ₅ are each independently an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or carbon. Represents an aralkyl group of 7 to 12, and may have an ether bond in the structure, provided that R ₁ or R ₂ includes at least one ether bond, and R ₄ represents a carbon number including an ether bond. And represents a divalent linking group of 2 to 12. R _{1 to} R ₅ may each independently be substituted with a fluorine atom.
Examples of the alkyl group having 1 to 12 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, pentyl group, A cyclopentyl group, a cyclohexyl group, etc. are mentioned, Preferably it is a C1-C6, Especially preferably, it is a 1-4 chain or cyclic alkyl group, However, It is preferable that it is a chain alkyl group.

As a C2-C12 alkenyl group, a vinyl group, a propenyl group, etc. are mentioned, Preferably it is 2-8, Most preferably, the thing of 2-4 is mentioned.
Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, and a xylyl group, and among them, a phenyl group is preferable.
Examples of the aralkyl group having 7 to 12 carbon atoms include a benzyl group and a phenethyl group, and among them, a benzyl group is preferable.
_{Incidentally, R 1, R 2, R} 3, and alkyl group having 1 to 12 carbon atoms represented by _{R 5,} alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, and 7 carbon atoms The 12 aralkyl groups may have an ether bond in the structure, and one or more ether bonds may be present. The number of ether bonds is usually 1 or 2.
R ₁ or R ₂ includes at least one ether bond.

Examples of the group represented by R ₁ , R ₂ , R ₃ , and R ₅ having an ether bond in the structure include alkoxyalkyl groups such as a methoxymethyl group, a 2-methoxyethyl group, and a 2-ethoxyethyl group, Alkoxyalkenyl groups such as 2-methoxyvinyl group and 3-methoxy-2-propenyl group, alkoxyaryl groups such as 2-methoxyphenyl group, 3-methoxyphenyl group and 4-methoxyphenyl group, 2-methoxybenzyl group, 3 Examples thereof include aralkyloxyalkyl groups such as -methoxybenzyl group and 4-methoxybenzyl group.

  The alkyl group, alkenyl group, aryl group and aralkyl group may be substituted with a fluorine atom. Examples of the fluorine-substituted group include a trifluoromethyl group, a trifluoroethyl group and a pentafluoroethyl group. Fluorinated alkenyl groups such as fluorinated alkyl groups, 2-fluorovinyl groups, 3-fluoro-2-propenyl groups, 2-fluorophenyl groups, 3-fluorophenyl groups, 4-fluorophenyl groups, 2,4-difluorophenyl Group, fluorinated aryl group such as 3,5-difluorophenyl group, 2-fluorobenzyl group, 3-fluorobenzyl group, 4-fluorobenzyl group, 2,4-difluorobenzyl group, 3,5-difluorobenzyl group, etc. Of the aralkyl fluoride group.

R ₄ is a divalent linking group having 2 to 12 carbon atoms which may contain an ether bond and may be substituted with a fluorine atom, and the ether bond may be one or plural. More specifically, it is a divalent linking group in which at least two alkylene groups which may be substituted with fluorine atoms are linked via an ether bond, and both ends are carbon atoms. Examples of the linking group containing an ether bond include the following.

Examples of the linking group R ₄ substituted with a fluorine atom include the following.

From the viewpoint of easy availability, a divalent linking group having 4 to 12 carbon atoms is preferable, and in particular, —CH ₂ —CH ₂ — (O—CH ₂ —CH ₂ ) _n — (where n is 1 to 3). An integer).
The molecular weight of the compound represented by the general formula (1) is usually 140 or more, usually 1000 or less, preferably 500 or less, more preferably 300 or less.
The molecular weight of the compound represented by the general formula (2) is usually 234 or more, usually 1200 or less, preferably 700 or less, more preferably 500 or less.

Specific examples of the compound of the general formula (1) in which R ₁ has an ether bond include methoxymethyl-methanesulfonate, 2-methoxyethyl-methanesulfonate, 2-ethoxyethyl-methanesulfonate, 3-methoxypropyl-methanesulfonate, 2- (2-methoxyethoxy) ethyl-methanesulfonate, 2- (2-ethoxyethoxy) ethyl-methanesulfonate, methoxymethyl-ethanesulfonate, 2-methoxyethyl-ethanesulfonate, 2-ethoxyethyl-ethanesulfonate, 3- Methoxypropyl-ethanesulfonate, 2- (2-methoxyethoxy) ethyl-ethanesulfonate, 2- (2-ethoxyethoxy) ethyl-ethanesulfonate, methoxymethyl-vinylsulfonate, 2-methoxyethyl-vinyl Sulfonate, 2-ethoxyethyl-vinyl sulfonate, methoxymethyl-benzene sulfonate, 2-methoxyethyl-benzene sulfonate, 2-ethoxyethyl-benzene sulfonate, methoxymethyl-benzyl sulfonate, 2-methoxyethyl-benzyl sulfonate, 2-ethoxyethyl -Benzyl sulfonate, methoxymethyl-trifluoromethanesulfonate, 2-methoxyethyl-trifluoromethanesulfonate, 2-ethoxyethyl-trifluoromethanesulfonate and the like.

Specific examples of the compound of the general formula (1) in which R ₂ has an ether bond include methyl-methoxymethanesulfonate, methyl-2-methoxyethanesulfonate, methyl-2-ethoxyethanesulfonate, methyl-3-methoxypropanesulfonate, Methyl-2- (2-methoxyethoxy) ethanesulfonate, ethyl-methoxymethanesulfonate, ethyl-2-methoxyethanesulfonate, ethyl-2-ethoxyethanesulfonate, ethyl-3-methoxypropanesulfonate, ethyl-2- (2- Methoxyethoxy) ethanesulfonate, vinyl-methoxymethanesulfonate, vinyl-2-methoxyethanesulfonate, vinyl-2-ethoxyethanesulfonate, phenyl-methoxymethanesulfonate, phenyl-2-methoxy Examples include siethane sulfonate, phenyl-2-ethoxyethane sulfonate, benzyl-methoxymethane sulfonate, benzyl-2-methoxyethane sulfonate, and benzyl-2-ethoxyethane sulfonate.

Specific examples of the compound of the general formula (2) in which R ₃ and R ₅ are alkyl groups having 1 to 12 carbon atoms include diethylene glycol dimethane sulfonate, diethylene glycol diethane sulfonate, diethylene glycol dipropane sulfonate, diethylene glycol dibutane sulfonate, triethylene glycol Ethylene glycol dimethane sulfonate, triethylene glycol diethane sulfonate, triethylene glycol dipropane sulfonate, triethylene glycol dibutane sulfonate, tetraethylene glycol dimethane sulfonate, tetraethylene glycol diethane sulfonate, tetraethylene glycol dipropane sulfonate, tetraethylene Examples include glycol dibutane sulfonate.

Specific examples of the compound of the general formula (2) in which R ₃ and R ₅ are alkenyl groups having 2 to 12 carbon atoms include diethylene glycol divinyl sulfonate, diethylene glycol diallyl sulfonate, triethylene glycol divinyl sulfonate, triethylene glycol diallyl sulfonate, tetra Examples include ethylene glycol divinyl sulfonate and tetraethylene glycol diallyl sulfonate.

Specific examples of the compound of the general formula (2) in which R ₃ and R ₅ are aryl groups having 6 to 12 carbon atoms include diethylene glycol dibenzene sulfonate, triethylene glycol dibenzene sulfonate, and tetraethylene glycol dibenzene sulfonate. .
Specific examples of the compound of the general formula (2) in which R ₃ and R ₅ are aralkyl groups having 7 to 12 carbon atoms include diethylene glycol dibenzyl sulfonate, triethylene glycol dibenzyl sulfonate, and tetraethylene glycol dibenzyl sulfonate. .

Compounds in which R ₃ , R ₄ and R ₅ are each independently fluorine-substituted include diethylene glycol di (trifluoromethanesulfonate), diethylene glycol di (pentafluoroethanesulfonate), diethylene glycol di (2,2,2-trifluoroethanesulfonate). ), Triethylene glycol di (trifluoromethanesulfonate), triethylene glycol di (pentafluoroethanesulfonate), triethylene glycol di (2,2,2-trifluoroethanesulfonate), tetraethylene glycol di (trifluoromethanesulfonate), Alkyl fluoride such as tetraethylene glycol di (pentafluoroethane sulfonate), tetraethylene glycol di (2,2,2-trifluoroethane sulfonate) A compound containing a hydrogen group, diethylene glycol di (2-fluorobenzenesulfonate), diethylene glycol di (3-fluorobenzenesulfonate), diethylene glycol di (4-fluorobenzenesulfonate), diethylene glycol di (2,4-difluorobenzenesulfonate), diethylene glycol di (3,5-difluorobenzene sulfonate), triethylene glycol di (2-fluorobenzene sulfonate), triethylene glycol di (3-fluorobenzene sulfonate), triethylene glycol di (4-fluorobenzene sulfonate), triethylene glycol di Fluorinated aryls such as (2,4-difluorobenzenesulfonate) and triethylene glycol di (3,5-difluorobenzenesulfonate) 1H, 1H, 5H, 5H-tetrafluoro-3-oxapentane-1,5-diol dimethanesulfonate, 1H, 1H, 8H, 8H-octafluoro-3,6-dioxaoctane-1 , 8-diol dimethanesulfonate and the like, and compounds containing a group in which R ₄ is fluorinated.

Among these, in the compound of the general formula (1), methoxymethyl-methanesulfonate, 2-methoxyethyl-methanesulfonate, 2-ethoxyethyl-methanesulfonate, 3-methoxypropyl-methanesulfonate, 2- (2-methoxy) Ethoxy) ethyl-methanesulfonate, 2- (2-ethoxyethoxy) ethyl-methanesulfonate, methoxymethyl-ethanesulfonate, 2-methoxyethyl-ethanesulfonate, 2-ethoxyethyl-ethanesulfonate, 3-methoxypropyl-ethanesulfonate, 2- (2-methoxyethoxy) ethyl - ethanesulfonate, 2- (2-ethoxyethoxy) ethyl - compounds in which R ₁ has an ether bond, such as ethanesulfonate, alkyl der particularly R ₁ has an ether bond Preferably the compound is in terms of ease of synthesis, among others, and even more preferably R ₂ is an unsubstituted alkyl group having 1 to 6 carbon atoms. In the compound of the general formula (2), diethylene glycol dimethane sulfonate, diethylene glycol diethane sulfonate, diethylene glycol dipropane sulfonate, diethylene glycol dibutane sulfonate, triethylene glycol dimethane sulfonate, triethylene glycol diethane sulfonate, triethylene glycol dipropane sulfonate. R ₃ and R ₅ in the general formula (2) such as triethylene glycol dibutane sulfonate, tetraethylene glycol dimethane sulfonate, tetraethylene glycol diethane sulfonate, tetraethylene glycol dipropane sulfonate, tetraethylene glycol dibutane sulfonate A compound which is independently an unsubstituted alkyl group having 1 to 6 carbon atoms Especially those wherein R ₃ and R ₅ is an unsubstituted alkyl group having 1 to 6 carbon atoms with the same is preferable from the easiness of synthesis.

As the compound represented by the general formula (1) and / or (2), any one of the compounds represented by the general formula (1) or (2) may be used alone, or two or more kinds may be used in combination. . In the case of combined use, the compound represented by the general formula (1) and the compound represented by the general formula (2) can be combined with the compound represented by the general formula (1) and the compound represented by the general formula (2). You may use together.
The total ratio of the compounds represented by the general formula (1) and / or (2) in the nonaqueous electrolytic solution is usually 0.001% by weight or more, preferably 0.1% by weight or more, and further 0 It is preferably 2% by weight or more, particularly preferably 0.25% by weight or more. At a concentration lower than this, the effect of the present invention is hardly exhibited. On the other hand, if the concentration is too high, the storage characteristics of the battery tend to deteriorate. Therefore, the upper limit is usually 5% by weight or less, preferably 4% by weight or less, more preferably 2% by weight or less, and most preferably 1%. % By weight or less.

The reason why the non-aqueous electrolyte battery suppresses gas generation and capacity reduction during high-temperature storage by using an electrolytic solution containing the compound represented by the general formula (1) and / or (2) is clear. However, it is guessed as follows.
First, the compound represented by the general formula (1) and / or (2) forms a film on the surface of the positive electrode, and this film prevents contact between the active positive electrode and the electrolytic solution, and suppresses decomposition of the electrolytic solution. And it seems that the increase in the amount of gas generation can be suppressed. In addition, the positive electrode surface coating derived from the compound represented by the general formula (1) and / or (2) contains a large amount of oxygen atoms as inferred from the general formula (1) or (2), and is lithium ion permeable. Therefore, it is presumed that gas generation and capacity reduction during high-temperature storage can be suppressed while maintaining good cycle characteristics.

The non-aqueous electrolyte solution according to the present invention includes various assistants such as a cyclic carbonate having an unsaturated bond in the molecule, a conventionally known overcharge inhibitor, a deoxidizer, and a dehydrator as long as the effects of the present invention are not impaired. An agent may be contained.
Since the cyclic carbonate having an unsaturated bond in the molecule forms a stable protective film on the surface of the negative electrode, the cycle characteristics of the battery can be improved. Examples of the cyclic carbonate having an unsaturated bond in the molecule include vinylene carbonate compounds, vinyl ethylene carbonate compounds, methylene ethylene carbonate compounds, and the like.

Examples of the vinylene carbonate-based compound include vinylene carbonate, methyl vinylene carbonate, ethyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, 4,5-diethyl vinylene carbonate, fluorovinylene carbonate, trifluoromethyl vinylene carbonate, and the like.
Examples of the vinyl ethylene carbonate compound include vinyl ethylene carbonate, 4-methyl-4-vinyl ethylene carbonate, 4-ethyl-4-vinyl ethylene carbonate, 4-n-propyl-4-vinyl ethylene carbonate, 5-methyl-4- Examples include vinyl ethylene carbonate, 4,4-divinyl ethylene carbonate, 4,5-divinyl ethylene carbonate, and the like.

Examples of the methylene ethylene carbonate compound include methylene ethylene carbonate, 4,4-dimethyl-5-methylene ethylene carbonate, 4,4-diethyl-5-methylene ethylene carbonate, and the like.
Among these, vinylene carbonate and vinyl ethylene carbonate are preferable from the viewpoint of improving cycle characteristics, and vinylene carbonate is particularly preferable.

These may be used alone or in combination of two or more.
When using 2 or more types together, it is preferable to use together vinylene carbonate and vinyl ethylene carbonate.
When the non-aqueous electrolyte contains a cyclic carbonate having an unsaturated bond in the molecule, the proportion in the non-aqueous electrolyte is usually 0.01% by weight or more, preferably 0.1% by weight or more, particularly preferably It is 0.3% by weight or more, most preferably 0.5% by weight or more. When there are too few cyclic carbonate compounds which have an unsaturated bond in a molecule | numerator, the effect of improving the cycling characteristics of a battery cannot fully be exhibited. In addition, the cyclic carbonate having an unsaturated bond in the molecule easily reacts with the positive electrode material in a charged state, and if the electrolyte contains the cyclic carbonate having an unsaturated bond in the molecule, the amount of gas generated increases at high temperature storage. However, when used in combination with the compound represented by the general formula (1) and / or (2), an increase in the amount of gas generated can be suppressed, and both improvement of cycle characteristics and suppression of gas generation can be achieved. Particularly preferred. However, when the content of the cyclic carbonate having an unsaturated bond in the molecule is too large, the amount of gas generated during high-temperature storage tends to increase or the discharge characteristics at low temperatures tend to decrease. % By weight or less, preferably 4% by weight or less, particularly preferably 3% by weight or less.

Moreover, when it contains the cyclic carbonate which has an unsaturated bond in a molecule | numerator, the weight ratio (the former of the compound represented by General formula (1) and / or (2) and the cyclic carbonate which has an unsaturated bond in a molecule | numerator). The total: the latter) is usually 1: 0.1-50, preferably 1: 0.5-25, at the stage of preparing the electrolytic solution.
As an overcharge inhibitor, aromatic compounds such as biphenyl, alkylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran; 2-fluorobiphenyl, Partially fluorinated products of the above aromatic compounds such as o-cyclohexylfluorobenzene and p-cyclohexylfluorobenzene; 2,4-difluoroanisole, 2,5-difluoroanisole, 2,6-difluoroanisole, 3,5-difluoroanisole and the like And a fluorine-containing anisole compound.

  Of these, aromatic compounds such as biphenyl, alkylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, and dibenzofuran are preferable. Two or more of these may be used in combination. When two or more kinds are used in combination, in particular, a combination of cyclohexylbenzene and t-butylbenzene or t-amylbenzene, biphenyl, alkylbiphenyl, terphenyl, terphenyl partially hydrogenated product, cyclohexylbenzene, or t-butylbenzene. It is preferable to use together those selected from aromatic compounds not containing oxygen such as t-amylbenzene and those selected from oxygen-containing aromatic compounds such as diphenyl ether and dibenzofuran.

  The proportion of the overcharge inhibitor in the non-aqueous electrolyte is usually 0.1% by weight or more, preferably 0.2% by weight or more, particularly preferably 0.3% by weight or more, and most preferably 0.5% by weight or more. The upper limit is usually 5% by weight or less, preferably 3% by weight or less, and particularly preferably 2% by weight or less. By containing an overcharge preventing agent, rupture / ignition of the battery can be suppressed during overcharge or the like.

  In general, these overcharge inhibitors react more easily on the positive electrode and the negative electrode than the solvent component of the electrolyte solution, and thus react at a highly active site of the electrode even during high-temperature storage, and these compounds react. Although the internal resistance of the battery was greatly increased and gas generation caused a significant decrease in the discharge characteristics after storage at high temperatures, when added to the electrolytic solution of the present invention, the deterioration of the discharge characteristics was suppressed. Can do.

Other auxiliaries include carbonate compounds such as fluoroethylene carbonate, trifluoropropylene carbonate, phenylethylene carbonate, erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl-methyl carbonate; succinic anhydride, glutaric anhydride, Carboxylic anhydrides such as maleic anhydride, citraconic anhydride, glutaconic anhydride, itaconic anhydride, diglycolic anhydride, cyclohexanedicarboxylic anhydride, cyclopentanetetracarboxylic dianhydride and phenylsuccinic anhydride; 2, Spiro compounds such as 4,8,10-tetraoxaspiro [5.5] undecane and 3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane; ethylene sulfite, 1, 3-propanesulfur 1,4-butane sultone, methyl methanesulfonate, ethyl methanesulfonate, busulfan, sulfolane, sulfolene, dimethylsulfone, diphenylsulfone, N, N-dimethylmethanesulfonamide, N, N-diethylmethanesulfonamide, etc. Sulfur compounds; 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 Hydrocarbon compounds such as heptane, octane and cycloheptane, and fluorine-containing aromatic compounds such as fluorobenzene, difluorobenzene, hexafluorobenzene and benzotrifluoride. Two or more of these may be used in combination.
The ratio of these auxiliaries in the non-aqueous electrolyte is usually 0.01% by weight or more, preferably 0.1% by weight or more, particularly preferably 0.2% by weight or more, and the upper limit is usually 5% by weight. Hereinafter, it is preferably 3% by weight or less, particularly preferably 1% by weight or less. By adding these auxiliaries, capacity maintenance characteristics and cycle characteristics after high temperature storage can be improved.

(Preparation of electrolyte)
The non-aqueous electrolyte solution according to the present invention can be prepared by dissolving the electrolyte, the compound represented by the general formula (1) and / or (2) and other compounds as required in a non-aqueous solvent. it can. In preparing the non-aqueous electrolyte solution, each raw material is preferably dehydrated in advance. Usually, it is good to dehydrate to 50 ppm or less, preferably 30 ppm or less.
(Lithium secondary battery)
The non-aqueous electrolyte solution according to the present invention is suitable for use as an electrolyte solution for secondary batteries, particularly for lithium secondary batteries among batteries. Hereinafter, a lithium secondary battery according to the present invention using this electrolytic solution will be described.

  The lithium secondary battery according to the present invention is the same as the conventionally known lithium secondary battery except that the lithium secondary battery is produced using the electrolytic solution of the present invention. A non-aqueous electrolyte battery containing a liquid is usually obtained by housing a positive electrode and a negative electrode in a case through a porous membrane impregnated with the non-aqueous electrolyte solution according to the present invention. Therefore, the shape of the secondary battery according to the present invention is not particularly limited, and may be any of a cylindrical shape, a square shape, a laminate shape, a coin shape, a large size, and the like. Since the lithium secondary battery according to the present invention generates a small amount of gas during high-temperature storage as described above, the current during high-temperature storage of a battery equipped with a current interrupting device that operates due to an increase in battery internal pressure during abnormal conditions such as overcharging. Abnormal operation of the shut-off device can be prevented. In addition, in a battery whose outer casing has a thickness of 0.4 mm or less and whose outer casing is mainly made of metal aluminum or aluminum alloy, a problem of battery swelling due to an increase in battery internal pressure is likely to occur. Since lithium secondary batteries generate less gas, it is possible to prevent such problems from occurring.

As the negative electrode active material, a carbonaceous material or metal compound capable of inserting and extracting lithium, lithium metal, lithium alloy, and the like can be used. These negative electrode active materials may be used alone or in combination of two or more. Among these, a carbonaceous material and a metal compound capable of occluding and releasing lithium are preferable.
Among the carbonaceous materials, graphite and graphite whose surface is coated with amorphous carbon as compared with graphite are particularly preferable.

  Graphite preferably has a lattice plane (002 plane) d value (interlayer distance) of 0.335 to 0.338 nm, particularly 0.335 to 0.337 nm, as determined by X-ray diffraction using the Gakushin method. The crystallite size (Lc) determined by X-ray diffraction by the Gakushin method is usually 30 nm or more, preferably 50 nm or more, particularly preferably 100 nm or more. The ash content is usually 1% by weight or less, preferably 0.5% by weight or less, particularly preferably 0.1% by weight or less.

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

The particle size of the carbonaceous material is a median diameter measured by a laser diffraction / scattering method and is usually 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, most preferably 7 μm or more, and usually 100 μm or less, preferably 50 μm or less, More preferably, it is 40 micrometers or less, Most preferably, it is 30 micrometers or less.
The specific surface area of the carbonaceous material by the BET method is usually 0.3 m ² / g or more, preferably 0.5
m ² / g or more, more preferably 0.7 m ² / g or more, and most preferably 0.8 m ² / g or more and usually 25.0 m ² / g or less, preferably 20.0 m ² / g, more Preferably it is 15.0 m < ² > / g or less, Most preferably, it is 10.0 m < ² > / g or less.

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

  Examples of metal compounds capable of inserting and extracting lithium include compounds containing metals such as Ag, Zn, Al, Ga, In, Si, Ge, Sn, Pb, P, Sb, Bi, Cu, Ni, Sr, and Ba. These metals are used as simple substances, oxides, alloys with lithium, and the like. In the present invention, those containing an element selected from Si, Sn, Ge and Al are preferred, and oxides or lithium alloys of metals selected from Si, Sn and Al are more preferred.

A metal compound capable of occluding and releasing lithium, or an oxide thereof or an alloy with lithium generally has a larger capacity per unit weight than a carbon material typified by graphite, and therefore requires a higher energy density. It is suitable for a secondary battery.
Examples of the positive electrode active material include materials capable of inserting and extracting lithium, such as lithium transition metal composite oxide materials such as lithium cobalt oxide, lithium nickel oxide, and lithium manganese oxide. These compounds include Li _X CoO ₂ , Li _X NiO ₂ , Li _X MnO ₂ , Li _X Co _{1- y My} O ₂ , Li _X Ni _{1- y My} O ₂ , Li _X Mn _{1- y My} O ₂ or the like, where M is usually at least one selected from Fe, Co, Ni, Mn, Mg, Cu, Zn, Al, Sn, B, Ga, Cr, V, Sr, Ti, 0.4 ≦ x ≦ 1.2, 0 ≦ y ≦ 0.6, or Li _X Mn _a Ni _b Co _c O ₂ (where 0.4 ≦ x ≦ 1.2, a + b + c = 1) Can be mentioned.

Especially represented by _{Li X Co 1-y M y} O 2, Li X Ni 1-y M y O 2, Li X Mn 1-y M y O 2 , etc., cobalt, nickel, and other part of manganese What is replaced with metal or Li _X Mn _a Ni _b Co _c O ₂ (where 0.4 ≦ x ≦ 1.2, a + b + c = 1, | ab | <0.1) This is preferable because the structure can be stabilized.
The positive electrode active materials may be used alone or in combination.

  As the binder for binding the active material, any material can be used as long as it is a material that is stable with respect to the solvent and the electrolyte used in manufacturing the electrode. For example, fluororesins such as polyvinylidene fluoride and polytetrafluoroethylene, polyolefins such as polyethylene and polypropylene, polymers having unsaturated bonds such as styrene / butadiene rubber, isoprene rubber and butadiene rubber, and copolymers thereof, ethylene-acrylic Examples thereof include acrylic acid polymers such as acid copolymers and ethylene-methacrylic acid copolymers, and copolymers thereof.

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

Examples of the conductive material include a metal material such as copper or nickel, and a carbon material such as graphite or carbon black.
The electrode may be manufactured by a conventional method. For example, it can be formed by adding a binder, a thickener, a conductive material, a solvent or the like to a negative electrode or a positive electrode active material to form a slurry, applying the slurry to a current collector, drying it, and then pressing it.

In addition, a material obtained by adding a binder or a conductive material to an active material is roll-formed as it is to form a sheet electrode, a pellet electrode is formed by compression molding, and an electrode is formed on the current collector by a technique such as vapor deposition, sputtering, or plating. A thin film of material can also be formed.
When graphite is used as the negative electrode active material, the density of the negative electrode active material layer after drying and pressing is usually 1.45 g / cm ³ or more, preferably 1.55 g / cm ³ or more, particularly preferably 1.60 g. / Cm ³ or more.

Further, the density after drying and pressing of the positive electrode active material layer is usually 2.0 g / cm ³ or more, preferably 3.0 g / cm ³ or more.
Various types of current collectors can be used, but metals and alloys are usually used. Examples of the current collector for the negative electrode include copper, nickel, and stainless steel, and copper is preferred. Examples of the positive electrode current collector include metals such as aluminum, titanium, and tantalum, and alloys thereof, and aluminum or an alloy thereof is preferable.

A porous film is interposed between the positive electrode and the negative electrode to prevent a short circuit. In this case, the electrolytic solution is used by impregnating the porous membrane. The material and shape of the porous film are not particularly limited as long as it is stable to the electrolytic solution and excellent in liquid retention, and a porous sheet or nonwoven fabric made of a polyolefin such as polyethylene or polypropylene is preferable.
The material of the battery casing used in the battery according to the present invention is also arbitrary, and nickel-plated iron, stainless steel, aluminum or an alloy thereof, nickel, titanium, a laminate film, or the like is used.
The operating voltage of the battery according to the present invention is usually in the range of 2V to 6V.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.
In addition, each evaluation method of the battery obtained by the following Example and the comparative example is shown below.
[Capacity evaluation]
A lithium secondary battery is charged to 4.2 V at a constant current corresponding to 0.2 C at 25 ° C. in a state of being sandwiched between glass plates in order to enhance adhesion between electrodes, and then a constant current of 0.2 C Was discharged to 3V. This is done for 3 cycles to stabilize the battery. In the 4th cycle, after charging to 4.2V with a constant current of 0.5C, charging is performed until the current value reaches 0.05C with a constant voltage of 4.2V. The initial discharge capacity was determined by discharging to 3 V at a constant current of 0.2C.
Here, 1C represents a current value for discharging the reference capacity of the battery in one hour, and 0.2C represents a current value of 1/5 thereof.

[Evaluation of high-temperature storage characteristics]
The battery for which the capacity evaluation test has been completed is charged to 4.2 V at a constant current of 0.5 C at 25 ° C., and then charged to a current value of 0.05 C at a constant voltage of 4.2 V, and then at 85 ° C. Stored for 3 days. After sufficiently cooling the battery, the volume was measured by immersion in an ethanol bath, and the amount of gas generated from the volume change before and after storage was determined.

After measuring the amount of gas generated, discharge to 3V at a constant current of 0.2C at 25 ° C, measure the discharge capacity after the storage test, determine the ratio of the discharge capacity after storage to the initial discharge capacity, and store this at high temperature The remaining capacity (%) was used.
Next, the battery is charged to 4.2 V with a constant current of 0.5 C, and further charged to a current value of 0.05 C with a constant voltage of 4.2 V, and then discharged to 3 V with a constant current of 1 C. The discharge capacity at the time of 1C discharge was measured, the ratio of the 1C discharge capacity after storage to the initial discharge capacity was determined, and this was defined as the high load discharge capacity (%) after storage at high temperature.

Example 1
[Manufacture of negative electrode]
The d-value of the lattice plane (002 plane) in X-ray diffraction is 0.336 nm, the crystallite size (Lc) is 652 nm, the ash content is 0.07 wt%, the median diameter by laser diffraction / scattering method is 12 μm, and the ratio by BET method Surface area is 7.5 m ² / g, R value (= I _B / I _A ) determined from Raman spectrum analysis using argon ion laser light is 0.12, and half width of peak in the range of 1570 to 1620 cm ⁻¹ Was mixed with 94 parts by weight of natural graphite powder having a weight of 19.9 cm ⁻¹ and 6 parts by weight of polyvinylidene fluoride, and N-methyl-2-pyrrolidone was added to form a slurry. This slurry was uniformly applied to one side of a 12 μm thick copper foil, dried, and then pressed so that the density of the negative electrode active material layer was 1.6 g / cm ³ to obtain a negative electrode.

[Production of positive electrode]
Mix 85 parts by weight of LiCoO ₂ , 6 parts by weight of carbon black and 9 parts by weight of polyvinylidene fluoride (product name “KF-1000” manufactured by Kureha Chemical Co., Ltd.), and add N-methyl-2-pyrrolidone to make a slurry. After uniformly applying and drying on both surfaces of a 15 μm thick aluminum foil, the positive electrode active material layer was pressed to a density of 3.0 g / cm ³ to obtain a positive electrode.
[Manufacture of electrolyte]
Under a dry argon atmosphere, 97.5 parts by weight of a mixture of ethylene carbonate, ethyl methyl carbonate and dimethyl carbonate (volume ratio 2: 4: 4), 2 parts by weight of vinylene carbonate and 0.5 parts by weight of 2-methoxyethyl-methanesulfonate Next, fully dried LiPF ₆ was dissolved at a rate of 1.0 mol / liter to obtain an electrolytic solution.

[Manufacture of lithium secondary batteries]
The positive electrode, the negative electrode, and the polyethylene separator were laminated in the order of the negative electrode, the separator, the positive electrode, the separator, and the negative electrode to prepare a battery element. The battery element was inserted into a bag made of a laminate film in which both surfaces of aluminum (thickness: 40 μm) were coated with a resin layer while projecting positive and negative terminals, and then the electrolyte was poured into the bag and vacuum sealed. The sheet-like battery was manufactured and evaluated.
The components of the electrolytic solution and the evaluation results are shown in Tables 1 and 2.

(Example 2)
A sheet-like lithium secondary battery was prepared and evaluated in the same manner as in Example 1 except that diethylene glycol dimethanesulfonate was used instead of 2-methoxyethyl-methanesulfonate. The components of the electrolytic solution and the evaluation results are shown in Tables 1 and 2.
Example 3
A sheet-like lithium secondary battery was prepared in the same manner as in Example 1 except that 97.8 parts by weight of a mixture of ethylene carbonate, ethyl methyl carbonate and dimethyl carbonate and 0.2 parts by weight of 2-methoxyethyl-methanesulfonate were used. And evaluated. The components of the electrolytic solution and the evaluation results are shown in Tables 1 and 2.

(Comparative Example 1)
A sheet-like lithium secondary battery was prepared in the same manner as in Example 1 except that 98 parts by weight of a mixture of ethylene carbonate, ethyl methyl carbonate, and dimethyl carbonate was used, and 2-methoxyethyl-methanesulfonate was not used. And evaluated. The components of the electrolytic solution and the evaluation results are shown in Tables 1 and 2.
(Comparative Example 2)
A sheet-like lithium secondary battery was prepared and evaluated in the same manner as in Example 1 except that methyl-methanesulfonate was used instead of 2-methoxyethyl-methanesulfonate. The components of the electrolytic solution and the evaluation results are shown in Tables 1 and 2.

(Comparative Example 3)
A sheet-like lithium secondary battery was prepared and evaluated in the same manner as in Example 1 except that 1,4-butanediol dimethanesulfonate was used instead of 2-methoxyethyl-methanesulfonate. The components of the electrolytic solution and the evaluation results are shown in Tables 1 and 2.

(Example 4 / Example using a metal capable of forming an alloy with lithium for the negative electrode active material)
In Example 1, a sheet-like lithium secondary battery was produced and evaluated in the same manner except that the negative electrode and the electrolyte obtained by the following method were used. The evaluation results are shown in Table-3.
[Manufacture of negative electrode]
Si powder (average particle size 3 μm) 73 parts by weight, Cu powder (average particle size 2 μm) 8 parts by weight, artificial graphite powder 12 parts by weight, polyvinylidene fluoride 7 parts by weight, N-methyl-2-pyrrolidone was mixed It was made into a slurry, and this slurry was uniformly applied to one side of a copper foil having a thickness of 12 μm, dried and then pressed to obtain a negative electrode.
[Manufacture of electrolyte]
Under a dry argon atmosphere, 98.5 parts by weight of a mixture of ethylene carbonate, ethylmethyl carbonate and diethyl carbonate (volume ratio 2: 4: 4), 1 part by weight of vinylene carbonate and 0.5 parts by weight of 2-methoxyethyl-methanesulfonate Next, fully dried LiPF ₆ was dissolved at a rate of 1.0 mol / liter to obtain an electrolytic solution.
(Comparative Example 4)
A sheet-like lithium secondary battery was prepared in the same manner as in Example 4 except that 99 parts by weight of a mixture of ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate was used, and 2-methoxyethyl-methanesulfonate was not used. Evaluation was performed. The evaluation results are shown in Table-3.

  As is apparent from Tables 1 to 3, it can be seen that the battery according to the present invention has a small amount of gas generated after high-temperature storage and is excellent in battery characteristics.

Claims (6)

A non-aqueous electrolytic solution comprising an electrolyte and a non-aqueous solvent for dissolving the electrolyte, wherein the non-aqueous electrolytic solution contains a compound represented by the following general formula (1) and / or (2) liquid.

(In the formula, R ₁ , R ₂ , R ₃ and R ₅ are each independently an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or carbon. Represents an aralkyl group of 7 to 12, and may have an ether bond in the structure, provided that R ₁ or R ₂ includes at least one ether bond, and R ₄ represents a carbon number including an ether bond. Represents a divalent linking group of 2 to 12. In addition, R _{1 to} R ₅ may each independently be substituted with a fluorine atom, among the compounds represented by the general formula (1) . And R ₁ is a vinyl group, R ₁ is a group containing a vinyloxy group, and R ₂ is a group containing a vinyloxy group. The non-aqueous electrolyte solution according to claim 1, wherein the non-aqueous electrolyte solution includes a compound represented by the general formula (1), and R ₁ includes an ether bond. Include compounds nonaqueous electrolytic solution is represented by the general formula (2), R ₃ and R ₅ are independently a non-aqueous electrolyte according to claim 1 is an unsubstituted alkyl group having 1 to 6 carbon atoms liquid.   The compound represented by the general formula (1) and / or (2) is contained in a proportion of 0.001 to 5% by weight in total with respect to the non-aqueous electrolyte solution. The non-aqueous electrolyte solution according to any one of the above.   The non-aqueous electrolyte solution according to any one of claims 1 to 4, comprising a cyclic carbonate compound having an unsaturated bond in a proportion of 0.01 to 8% by weight based on the non-aqueous electrolyte solution. .   A non-aqueous electrolyte battery comprising a negative electrode and a positive electrode capable of inserting and extracting lithium ions, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte battery is a non-aqueous electrolyte according to any one of claims 1 to 5. A non-aqueous electrolyte battery characterized by being produced using a liquid.