JP6884020B2 - Non-aqueous electrolyte for batteries and lithium secondary battery - Google Patents

Description

The present disclosure relates to a non-aqueous electrolyte solution for a battery and a lithium secondary battery.

In recent years, lithium secondary batteries have been widely used as power sources for electronic devices such as mobile phones and notebook computers, electric vehicles, and power storage. In particular, recently, there has been a rapid increase in demand for batteries with high capacity, high output, and high energy density that can be installed in hybrid vehicles and electric vehicles.
The lithium secondary battery includes, for example, a positive electrode and a negative electrode containing a material capable of occluding and releasing lithium, and a non-aqueous electrolyte solution for a battery containing a lithium salt and a non-aqueous solvent.
As the positive electrode active material used for the positive electrode, for example, lithium metal oxides such as _{LiCoO 2} , LiMnO ₂ , LiNiO ₂ , and LiFePO _{4 are used.
The non-aqueous electrolyte solution for batteries includes LiPF 6} , LiBF ₄ , and LiN (SO ₂ CF ₃ ) in a mixed solvent (non-aqueous solvent) of carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. _2. A solution mixed with a Li electrolyte such as LiN (SO ₂ CF ₂ CF ₃ ) _{2 is used.}
On the other hand, as active materials for negative electrodes used for negative electrodes, metallic lithium, metal compounds capable of occluding and releasing lithium (single metal, oxides, alloys with lithium, etc.) and carbon materials are known, and in particular, lithium is used. A lithium secondary battery using coke, artificial graphite, and natural graphite that can be occluded and released has been put into practical use.

In order to improve the performance of a battery (for example, a lithium secondary battery) containing a non-aqueous electrolyte solution for a battery, various additives are added to the non-aqueous electrolyte solution for a battery.
For example, a non-aqueous electrolyte solution for a battery containing a specific boron compound is known as a non-aqueous electrolyte solution for a battery capable of producing a secondary battery having good charge / discharge cycle life characteristics and high temperature standing characteristics (for example,). See Patent Document 1).
Further, as a non-aqueous electrolyte solution for a battery capable of producing a non-aqueous electrolyte secondary battery in which swelling of the battery at the time of initial charge / discharge is suppressed and the cycle characteristics are good, a specific carbodiimide, a specific sulfate ester and a specific boron A non-aqueous electrolyte solution for a battery containing at least one selected from the group consisting of compounds is known (see, for example, Patent Document 2).
Further, as a non-aqueous electrolytic solution with less swelling of a power storage element, a non-aqueous electrolytic solution containing a fluorinated cyclic carbonate and a boronic acid ester containing an aromatic hydrocarbon is known (for example, Patent Documents). 3). Examples of Patent Document 3 describe examples in which the content of the fluorinated cyclic carbonate with respect to the total amount of the non-aqueous solvent is 10% by volume or 30% by volume.

Japanese Patent No. 5112148 Japanese Patent No. 5364890 JP-A-2016-0995965

However, it may be required to further suppress the volume change of the battery when the fully charged battery is stored at a high temperature.
Therefore, an object of the present disclosure is a non-aqueous electrolyte solution for a battery capable of suppressing a change in the volume of a battery when a fully charged battery is stored at a high temperature, and a lithium secondary battery using this non-aqueous electrolyte solution for a battery. To provide.

Means for solving the above problems include the following aspects.
<1> Boronic acid having an aromatic hydrocarbon group and
A non-aqueous solvent in which the content of the fluorinated cyclic carbonate with respect to the total amount of the non-aqueous solvent is more than 0% by volume and 8% by volume or less,
A non-aqueous electrolyte solution for batteries containing.
<2> The non-aqueous electrolytic solution for a battery according to <1>, wherein the boronic acid is a compound (A) represented by the following formula (A).
R ¹ B (OH) ₂ ... (A)
[In the formula (A), R ¹ is substituted with at least one substituent selected from the group consisting of a halogen atom, a hydrocarbon group having 1 to 6 carbon atoms, and a halogenated hydrocarbon group having 1 to 6 carbon atoms. Represents an aryl group that may be. ]
^{<3> The battery according to <2>, wherein the R 1} in the formula (A) represents a phenyl group which may be substituted with at least one substituent selected from the group consisting of a fluorine atom and a vinyl group. For non-aqueous electrolyte.
<4> The battery according to any one of <1> to <3>, wherein the content of the boronic acid is 0.01% by mass to 2.0% by mass with respect to the total amount of the non-aqueous electrolyte solution for the battery. For non-aqueous electrolyte.
<5> Positive electrode and
Metallic lithium, lithium-containing alloys, metals or alloys that can be alloyed with lithium, oxides that can be doped and dedoped with lithium ions, transition metal nitrogen compounds that can be doped and dedoped with lithium ions, and lithium. A negative electrode containing at least one selected from the group consisting of carbon materials capable of doping and dedoping ions as a negative electrode active material, and a negative electrode.
The non-aqueous electrolyte solution for batteries according to any one of <1> to <4>.
Lithium secondary battery including.
<6> A lithium secondary battery obtained by charging / discharging the lithium secondary battery according to <5>.

According to the present disclosure, a non-aqueous electrolyte solution for a battery capable of suppressing a change in the volume of a fully charged battery when stored at a high temperature, and a lithium secondary battery using the non-aqueous electrolyte solution for a battery are provided. To.

It is a schematic perspective view which shows an example of the laminated type battery which is an example of the lithium secondary battery of this disclosure. It is schematic cross-sectional view in the thickness direction of the laminated type electrode body housed in the laminated type battery shown in FIG. It is the schematic cross-sectional view which shows the example of the coin type battery which is another example of the lithium secondary battery of this disclosure.

In the present specification, the numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.
In the present specification, the amount of each component in the composition is the total amount of the plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition. Means.

[Non-aqueous electrolyte for batteries]
The non-aqueous electrolyte solution for batteries (hereinafter, also simply referred to as “non-aqueous electrolyte solution”) of the present disclosure is used.
Boronic acid having an aromatic hydrocarbon group (hereinafter, also referred to as "specific boronic acid") and
A non-aqueous solvent in which the content of the fluorinated cyclic carbonate with respect to the total amount of the non-aqueous solvent (hereinafter, also simply referred to as “content of the fluorinated cyclic carbonate”) is more than 0% by volume and 8% by volume or less.
Contains.

According to the non-aqueous electrolyte solution of the present disclosure, it is possible to suppress a change in the volume of a fully charged battery when it is stored at a high temperature.
That is, when the battery containing the non-aqueous electrolytic solution of the present disclosure is stored at a high temperature in a fully charged state, the volume change of this battery due to the high temperature storage is suppressed.

The above-mentioned effect of the non-aqueous electrolyte solution of the present disclosure (that is, the effect of suppressing the volume change of the battery when the fully charged battery is stored at a high temperature; hereinafter, also referred to as "the effect of suppressing the volume change of the battery") is This effect is specifically exhibited by the combination of the specific boric acid and the fluorinated cyclic carbonate having a content of more than 0% by volume and 8% by volume or less based on the total amount of the non-aqueous solvent.
That is, when a non-aqueous electrolyte solution containing a specific boronic acid and not containing a fluorinated cyclic carbonate as a non-aqueous solvent is used (for example, Comparative Example 1 described later), the non-aqueous electrolyte solution of the present disclosure is used. Compared with the case of using, the volume change of the battery becomes large.
Further, when a non-aqueous electrolyte solution containing a specific boronic acid and a fluorinated cyclic carbonate as a non-aqueous solvent and having a fluorinated cyclic carbonate content of more than 8% by volume based on the total amount of the non-aqueous solvent is used ( For example, in Comparative Example 2) described later, the volume change of the battery becomes larger than that in the case of using the non-aqueous electrolyte solution of the present disclosure.

Further, the non-aqueous electrolytic solution of the present disclosure contains a non-aqueous solvent having a fluorinated cyclic carbonate content of more than 0% by volume and 8% by volume or less, and does not contain a specific boronic acid (for example, a non-aqueous electrolytic solution). Compared with Comparative Example 3) described later, the effect of increasing the initial discharge capacity of the battery is also excellent.

Hereinafter, each component of the non-aqueous electrolytic solution of the present disclosure will be described.

<Non-aqueous solvent>
The non-aqueous electrolyte solution of the present disclosure contains a non-aqueous solvent having a fluorinated cyclic carbonate content (that is, the content of the fluorinated cyclic carbonate with respect to the total amount of the non-aqueous solvent) of more than 0% by volume and 8% by volume or less. ..

(Fluorinated cyclic carbonate)
Examples of the fluorinated cyclic carbonate include fluoroethylene carbonate (FEC), 3-trifluoromethylethylene carbonate (TFPC), trans-difluoroethylene carbonate (DFEC) and the like, and FEC is particularly preferable.

The content of the fluorinated cyclic carbonate is more than 0% by volume and 8% by volume or less.
As described above, the effect of suppressing the volume change of the battery is specifically exhibited in this range.
The content of the fluorinated cyclic carbonate is more preferably 1% by volume to 8% by volume, further preferably 2% by volume to 7% by volume, from the viewpoint of more effectively exerting the effect of suppressing the volume change of the battery.

(Other non-aqueous solvents)
As other non-aqueous solvents other than the fluorinated cyclic carbonate (also simply referred to as “other non-aqueous solvents” in the present specification), various known ones can be appropriately selected.
As the other aprotic solvent, it is preferable to use at least one selected from a cyclic aprotic solvent and a chain aprotic solvent.
When aiming to improve the flash point of the solvent in order to improve the safety of the battery, it is preferable to use a cyclic aprotic solvent as the non-aqueous solvent.

-Cyclic aprotic solvent-
As the cyclic aprotic solvent, cyclic carbonate, cyclic carboxylic acid ester, cyclic sulfone, and cyclic ether can be used.
In the present specification, the term "cyclic carbonate" is used to mean a cyclic carbonate other than the fluorinated cyclic carbonate.

The cyclic aprotic solvent may be used alone or in combination of two or more.
The mixing ratio of the cyclic aprotic solvent in the non-aqueous solvent is 10% by mass to 100% by mass, more preferably 20% by mass to 90% by mass, and particularly preferably 30% by mass to 80% by mass. By setting such a ratio, the conductivity of the electrolytic solution related to the charge / discharge characteristics of the battery can be increased.

Specific examples of the cyclic carbonate include ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, and 2,3-pentylene carbonate. Of these, ethylene carbonate and propylene carbonate having a high dielectric constant are preferably used. In the case of a battery using graphite as the negative electrode active material, ethylene carbonate is more preferable. Moreover, you may use these cyclic carbonates in mixture of 2 or more types.

Specific examples of the cyclic carboxylic acid ester include γ-butyrolactone, δ-valerolactone, and alkyl substituents such as methyl γ-butyrolactone, ethyl γ-butyrolactone, and ethyl δ-valerolactone.

The cyclic carboxylic acid ester has a low vapor pressure, a low viscosity, and a high dielectric constant, and can reduce the viscosity of the electrolytic solution without lowering the flash point of the electrolytic solution and the degree of dissociation of the electrolyte. Therefore, it has a feature that the conductivity of the electrolytic solution, which is an index related to the discharge characteristics of the battery, can be increased without increasing the flammability of the electrolytic solution. It is preferable to use a cyclic carboxylic acid ester as the cyclic aprotic solvent. Among the cyclic carboxylic acid esters, γ-butyrolactone is most preferable.

Further, the cyclic carboxylic acid ester is preferably used by mixing with another cyclic aprotic solvent. For example, a mixture of a cyclic carboxylic acid ester and a cyclic carbonate and / or a chain carbonate can be mentioned.

Examples of cyclic sulfone include sulfolane, 2-methylsulfolane, 3-methylsulfolane, dimethylsulfone, diethylsulfone, dipropylsulfone, methylethylsulfone, methylpropylsulfone and the like.
Dioxolane can be mentioned as an example of the cyclic ether.

-Chain aprotic solvent-
As the chain aprotic solvent, a chain carbonate, a chain carboxylic acid ester, a chain ether, a chain phosphate ester and the like can be used.

The mixing ratio of the chain aprotic solvent in the non-aqueous solvent is 10% by mass to 100% by mass, more preferably 20% by mass to 90% by mass, and particularly preferably 30% by mass to 80% by mass.

Specifically, as the chain carbonate, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, ethyl methyl carbonate, ethyl propyl carbonate, dipropyl carbonate, methyl butyl carbonate, ethyl butyl carbonate, dibutyl carbonate, Methylpentyl carbonate, ethylpentyl carbonate, dipentyl carbonate, methylheptyl carbonate, ethylheptyl carbonate, diheptyl carbonate, methylhexyl carbonate, ethylhexyl carbonate, dihexyl carbonate, methyloctyl carbonate, ethyloctyl carbonate, dioctyl carbonate, methyltrifluoroethyl carbonate, etc. Can be mentioned. Two or more kinds of these chain carbonates may be mixed and used.

Specific examples of the chain carboxylic acid ester include methyl pivalate.
Specific examples of the chain ether include dimethoxyethane and the like.
Specific examples of the chain phosphate ester include trimethyl phosphate and the like.

-Combination of other non-aqueous solvents-
Other non-aqueous solvents may be used alone or in admixture of a plurality of types. Further, only one or more kinds of cyclic aprotic solvents may be used, one or more kinds of chain aprotic solvents may be used, or cyclic aprotic solvents and chain protics. Solvents may be mixed and used. When it is particularly intended to improve the load characteristics and low temperature characteristics of the battery, it is preferable to use a combination of a cyclic aprotic solvent and a chain aprotic solvent as the aprotic solvent.

Further, from the viewpoint of the electrochemical stability of the electrolytic solution, it is most preferable to apply cyclic carbonate to the cyclic aprotic solvent and to apply chain carbonate to the chain aprotic solvent. Further, the conductivity of the electrolytic solution related to the charge / discharge characteristics of the battery can also be enhanced by the combination of the cyclic carboxylic acid ester and the cyclic carbonate and / or the chain carbonate.

Specific combinations of cyclic carbonate and chain carbonate include ethylene carbonate and dimethyl carbonate, ethylene carbonate and methyl ethyl carbonate, ethylene carbonate and diethyl carbonate, propylene carbonate and dimethyl carbonate, propylene carbonate and methyl ethyl carbonate, and propylene carbonate. Diethyl carbonate, ethylene carbonate and propylene carbonate and methyl ethyl carbonate, ethylene carbonate and propylene carbonate and diethyl carbonate, ethylene carbonate and dimethyl carbonate and methyl ethyl carbonate, ethylene carbonate and dimethyl carbonate and diethyl carbonate, ethylene carbonate and methyl ethyl carbonate and diethyl carbonate. , Ethylene carbonate, dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and methyl ethyl carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate, ethylene carbonate, propylene carbonate, methyl ethyl carbonate and diethyl Examples thereof include carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate.

The mixing ratio of the cyclic carbonate and the chain carbonate in other non-aqueous solvents is expressed as a volume ratio, and the cyclic carbonate: chain carbonate is 5:95 to 80:20, more preferably 10:90 to 70:30. Particularly preferably, it is 15:85 to 55:45. By setting such a ratio, it is possible to suppress an increase in the viscosity of the electrolytic solution and increase the degree of dissociation of the electrolyte, so that the conductivity of the electrolytic solution related to the charge / discharge characteristics of the battery can be increased. Moreover, the solubility of the electrolyte can be further increased. Therefore, since the electrolytic solution having excellent electrical conductivity at room temperature or low temperature can be obtained, the load characteristics of the battery at room temperature to low temperature can be improved.

For other non-aqueous solvents, the description in paragraphs 0074 to 0083 of Japanese Patent No. 6017697 may be referred to.

The non-aqueous solvent in the non-aqueous electrolyte solution of the present disclosure preferably contains a cyclic carbonate, a chain carbonate, and a fluorinated cyclic carbonate.
The total amount of the cyclic carbonate, the chain carbonate, and the fluorinated cyclic carbonate with respect to the total amount of the non-aqueous solvent is preferably 60% by volume or more, more preferably 80% by volume or more, and 90% by volume or more. It is particularly preferable to have.
The preferable range of the mixing ratio of the cyclic carbonate and the chain carbonate is as described above.

<Specific boronic acid>
The non-aqueous electrolytic solution of the present disclosure contains at least one specific boronic acid (that is, boronic acid having an aromatic hydrocarbon group).
In the non-aqueous electrolytic solution of the present disclosure, as described above, the volume change of the battery is suppressed by the combination of the specific boronic acid and the non-aqueous solvent having a fluorinated cyclic carbonate content of more than 0% by volume and 8% by volume or less. The effect is exhibited.
Further, as described above, the non-aqueous electrolytic solution of the present disclosure contains a non-aqueous solvent having a fluorinated cyclic carbonate content of more than 0% by volume and 8% by volume or less, and does not contain specific boric acid. It is also excellent in the effect of increasing the initial discharge capacity of the battery as compared with the electrolytic solution.

The aromatic hydrocarbon group in the specific boronic acid (that is, a boronic acid having an aromatic hydrocarbon group) may be a monovalent aromatic hydrocarbon group (that is, an aryl group) or a divalent aromatic group. It may be a hydrocarbon group (that is, an arylene group) or an aromatic hydrocarbon group having a valence of 3 or more.

Among the specific boronic acids, boronic acid having a six-membered ring aromatic hydrocarbon group is more preferable.
The six-membered ring aromatic hydrocarbon group referred to here may be substituted with a substituent.

Hereinafter, specific examples of the specific boronic acid will be shown, but the specific boronic acid is not limited to the following specific examples.
1,4-Phenylboronic acid, 4,4'-biphenyldiboronic acid, 2- (methylthio) phenylboronic acid, 3- (methylthio) phenylboronic acid, 4- (methylthio) phenylboronic acid, 2- (dimethyl) Amino) phenylboronic acid, 3- (dimethylamino) phenylboronic acid, 4- (dimethylamino) phenylboronic acid, 2-formylphenylboronic acid, 3-formylphenylboronic acid, 4-formylphenylboronic acid, 2-hydroxy Phenylboronic acid, 3-hydroxyphenylboronic acid, 4-hydroxyphenylboronic acid, 2-methoxyphenylboronic acid, 3-methoxyphenylboronic acid, 4-methoxyphenylboronic acid, 2-cyanophenylboronic acid, 3-cyanophenyl Boronic acid, 4-cyanophenylboronic acid, 2- (trimethylsilyl) phenylboronic acid, 3- (trimethylsilyl) phenylboronic acid, 4- (trimethylsilyl) phenylboronic acid, 2-acetylphenylboronic acid, 3-acetylphenylboronic acid , 4-Acetylphenylboronic acid, 4-Phenoxyphenylboronic acid, 2,3-dimethoxyphenylboronic acid, 2,4-dimethoxylophenylboronic acid, 2,5-dimethoxyphenylboronic acid, 3,4-dimethoxyphenylboronic acid Acid, 3,5-dimethoxyphenylboronic acid, 3,6-dimethoxyphenylboronic acid,

2- (Methylsulfonyl) phenylboronic acid, 3- (methylsulfonyl) phenylboronic acid, 4- (methylsulfonyl) phenylboronic acid, 2-ethoxyphenylboronic acid, 3-ethoxyphenylboronic acid, 4-ethoxyphenylboronic acid , 2-propoxyphenylboronic acid, 3-propoxyphenylboronic acid, 4-propoxyphenylboronic acid, 2-isopropoxyphenylboronic acid, 3-isopropoxyphenylboronic acid, 4-isopropoxyphenylboronic acid, 2-hydroxymethyl Phenylboronic acid, 3-hydroxymethylphenylboronic acid, 4-hydroxymethylphenylboronic acid, 2- (trifluoromethoxy) phenylboronic acid, 3- (trifluoromethoxy) methylphenylboronic acid, 4- (trifluoromethoxy) Methylphenylboronic acid, 2-cyano-3-fluorophenylboronic acid, 2-cyano-4-fluorophenylboronic acid, 2-cyano-5-fluorophenylboronic acid, 2-cyano-6-fluorophenylboronic acid, 3 -Cyano-2-fluorophenylboronic acid, 3-cyano-4-fluorophenylboronic acid, 3-cyano-5-fluorophenylboronic acid, 3-cyano-6-fluorophenylboronic acid, 4-cyano-3-fluoro Phenylboronic acid,

2-Fluoro-3-methoxyphenylboronic acid, 2-fluoro-4-methoxyphenylboronic acid, 2-fluoro-5-methoxyphenylboronic acid, 2-fluoro-6-methoxyphenylboronic acid, 3-fluoro-2- Methoxyphenylboronic acid, 3-fluoro-4-methoxyphenylboronic acid, 3-fluoro-5-methoxyphenylboronic acid, 3-fluoro-6-methoxyphenylboronic acid, 4-fluoro-3-methoxyphenylboronic acid, 2 -Chloro-3-methoxyphenylboronic acid, 2-chloro-4-methoxyphenylboronic acid, 2-chloro-5-methoxyphenylboronic acid, 2-chloro-6-methoxyphenylboronic acid, 3-chloro-2-methoxy Phenylboronic acid, 3-chloro-4-methoxyphenylboronic acid, 3-chloro-5-methoxyphenylboronic acid, 3-chloro-6-methoxyphenylboronic acid, 4-chloro-3-methoxyphenylboronic acid, 2- Nitrophenylboronic acid, 3-nitrophenylboronic acid, 4-nitrophenylboronic acid, 2-carboxyphenylboronic acid, 3-carboxyphenylboronic acid, 4-carboxyphenylboronic acid, 2-carbamoylphenylboronic acid, 3-carbamoyl Siphenylboronic acid, 4-carbamoylphenylboronic acid,

2- (methoxycarbonyl) phenylboronic acid, 3- (methoxycarbonyl) phenylboronic acid, 4- (methoxycarbonyl) phenylboronic acid, 2- (ethoxycarbonyl) phenylboronic acid, 3- (ethoxycarbonyl) phenylboronic acid, 4- (ethoxycarbonyl) phenylboronic acid, 2-methoxy-3-methylphenylboronic acid, 2-methoxy-4-methylphenylboronic acid, 2-methoxy-5-methylphenylboronic acid, 2-methoxy-6-methyl Phenylboronic acid, 3-methoxy-2-methylphenylboronic acid, 3-methoxy-4-methylphenylboronic acid, 3-methoxy-5-methylphenylboronic acid, 3-methoxy-6-methylphenylboronic acid, 4- Methoxy-3-methylphenylboronic acid, 4-methoxy-2, 6-dimethylphenylboronic acid, 2- (dimethylcarbamoyl) phenylboronic acid, 3- (dimethylcarbamoyl) siphenylboronic acid, 4- (dimethylcarbamoyl) phenyl Phenylboronic acid,

2-Benzyloxyphenylboronic acid, 3-benziroxyphenylboronic acid, 4-benzyloxyphenylboronic acid, 2-acetamidophenylboronic acid, 3-acetamidosiphenylboronic acid, 4-acetamidophenylboronic acid, 2-formyl -3-methoxyphenylboronic acid, 2-formyl-4-methoxyphenylboronic acid, 2-formyl-5-methoxyphenylboronic acid, 2-formyl-6-methoxyphenylboronic acid, 3-formyl-2-methoxyphenylboronic acid Acid, 3-formyl-4-methoxyphenylboronic acid, 3-formyl-5-methoxyphenylboronic acid, 3-formyl-6-methoxyphenylboronic acid, 4-formyl-3-methoxyphenylboronic acid, 2-methyl- 3-Nitrophenylboronic acid, 2-methyl-4-nitrophenylboronic acid, 2-methyl-5-nitrophenylboronic acid, 2-methyl-6-nitrophenylboronic acid, 3-methyl-2-nitrophenylboronic acid , 3-Methyl-4-nitrophenylboronic acid, 3-methyl-5-nitrophenylboronic acid, 3-methyl-6-nitrophenylboronic acid, 4-methyl-3-nitrophenylboronic acid, 2-benzyloxy-3 -Fluorophenylboronic acid, 2-benzyloxy-4-fluorophenylboronic acid, 2-benzyloxy-5-fluorophenylboronic acid, 2-benzyloxy-6-fluorophenylboronic acid, 3-benzyloxy-2-fluorophenylboronic acid, 3-Benzyloxy-4-fluorophenylboronic acid, 3-benzyloxy-5-fluorophenylboronic acid, 3-benzyloxy-6-fluorophenylboronic acid, 4-benzyloxy-3-fluorophenylboronic acid, 3,4- (methylene) Dioxy) Phenylboronic acid.

Further, as the specific boronic acid, the compound (A) represented by the following formula (A) is preferable.

R ¹ B (OH) ₂ ... (A)

In formula (A), R ¹ is substituted with at least one substituent selected from the group consisting of halogen atoms, hydrocarbon groups with 1 to 6 carbon atoms, and halogenated hydrocarbon groups with 1 to 6 carbon atoms. Represents an aryl group that may be present.

As the halogen atom in the formula (A), a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom is preferable, a fluorine atom, a chlorine atom, or a bromine atom is more preferable, a fluorine atom or a chlorine atom is further preferable, and a fluorine atom. Is particularly preferable.

As the hydrocarbon group having 1 to 6 carbon atoms in the formula (A), an alkyl group having 1 to 6 carbon atoms or an alkenyl group having 1 to 6 carbon atoms is preferable, and a vinyl group is particularly preferable.

^{It is particularly preferable that R 1} in the formula (A) represents a phenyl group which may be substituted with at least one substituent selected from the group consisting of a fluorine atom and a vinyl group.

Hereinafter, specific examples of compound (A) will be shown, but compound (A) is not limited to the following specific examples.
Phenylboronic acid, 1-naphthalenboronic acid, 2-naphthalenboronic acid, 2-fluorophenylboronic acid, 2-bromophenylboronic acid, 2-chlorophenylboronic acid, 2-iodophenylboronic acid, 3-fluorophenylboronic acid, 3-Bromophenylboronic acid, 3-chlorophenylboronic acid, 3-iodophenylboronic acid, 4-fluorophenylboronic acid, 4-bromophenylboronic acid, 4-chlorophenylboronic acid, 4-iodophenylboronic acid,

2,3-Difluorophenylboronic acid, 2,4-difluorophenylboronic acid, 2,5-difluorophenylboronic acid, 3,4-difluorophenylboronic acid, 3,5-difluorophenylboronic acid, 3,6-difluoro Phenylboronic acid, 2,3-dibromophenylboronic acid, 2,4-dibromophenylboronic acid, 2,5-dibromophenylboronic acid, 3,4-dibromophenylboronic acid, 3,5-dibromophenylboronic acid, 3 , 6-Dibromophenylboronic acid, 2,3-dichlorophenylboronic acid, 2,4-dichlorophenylboronic acid, 2,5-dichlorophenylboronic acid, 3,4-dichlorophenylboronic acid, 3,5-dichlorophenylboronic acid, 3, 6-Dichlorophenylboronic acid, 2,3-diiodophenylboronic acid, 2,4-diiodrophenylboronic acid, 2,5-diiodophenylboronic acid, 3,4-diiodophenylboronic acid, 3,5 − Diiodophenylboronic acid, 3,6-diiodophenylboronic acid,

2,4,6-trifluorophenylboronic acid, 2,4,6-tribromophenylboronic acid, 2,4,6-trichlorophenylboronic acid, 2,4,6-triiodophenylboronic acid, hexafluorophenyl Boronic acid, hexabromophenylboronic acid, hexachlorophenylboronic acid, hexaiodophenylboronic acid,

2-Methylphenylboronic acid, 3-methylphenylboronic acid, 4-methylphenylboronic acid, 2-ethylphenylboronic acid, 3-ethylphenylboronic acid, 4-ethylphenylboronic acid, 2-propylphenylboronic acid, 3 -Propylphenylboronic acid, 4-propylphenylboronic acid, 2-isopropylphenylboronic acid, 3-isopropylphenylboronic acid, 4-isopropylphenylboronic acid,

2,3-Dimethylphenylboronic acid, 2,4-dimethyllophenylboronic acid, 2,5-dimethylphenylboronic acid, 3,4-dimethylphenylboronic acid, 3,5-dimethylphenylboronic acid, 3,6- Dimethylphenylboronic acid, 2,4,6-trimethylphenylboronic acid, 2,3-diethylphenylboronic acid, 2,4-diethyllophenylboronic acid, 2,5-diethylphenylboronic acid, 3,4-diethylphenyl Boronic acid, 3,5-diethylphenylboronic acid, 3,6-diethylphenylboronic acid, 2,4,6-triethylphenylboronic acid, 2,3-dipropylphenylboronic acid, 2,4-dipropyllophenylboronic acid Acid, 2,5-dipropylphenylboronic acid, 3,4-dipropylphenylboronic acid, 3,5-dipropylphenylboronic acid, 3,6-dipropylphenylboronic acid, 2,4,6-tripropyl Phenylboronic acid, 2,3-diisopropylphenylboronic acid, 2,4-diisopropyllophenylboronic acid, 2,5-diisopropylphenylboronic acid, 3,4-diisopropylphenylboronic acid, 3,5-diisopropylphenylboronic acid, 3,6-diisopropylphenylboronic acid, 2,4,6-triisopropylphenylboronic acid,

2-Chloro-3-fluorophenylboronic acid, 2-chloro-4-fluorophenylboronic acid, 2-chloro-5-fluorophenylboronic acid, 2-chloro-6-fluorophenylboronic acid, 3-chloro-2- Fluorophenylboronic acid, 3-chloro-4-fluorophenylboronic acid, 3-chloro-5-fluorophenylboronic acid, 3-chloro-6-fluorophenylboronic acid, 4-chloro-3-fluorophenylboronic acid, 2 -Fluoro-3-methylphenylboronic acid, 2-fluoro-4-methylphenylboronic acid, 2-fluoro-5-methylphenylboronic acid, 2-fluoro-6-methylphenylboronic acid, 3-fluoro-2-methyl Phenylboronic acid, 3-fluoro-4-methylphenylboronic acid, 3-fluoro-5-methylphenylboronic acid, 3-fluoro-6-methylphenylboronic acid, 4-fluoro-3-methylphenylboronic acid,

2- (Trifluoromethane) phenylboronic acid, 3- (trifluoromethane) phenylboronic acid, 4- (trifluoromethane) phenylboronic acid, 2-vinylphenylboronic acid, 3-vinylphenylboronic acid, 4-vinylphenylboronic acid , 2- (Bromomethyl) Phenylboronic Acid, 3- (Bromomethyl) Phenylboronic Acid, 4- (Bromomethyl) Phenylboronic Acid, 2-Chloro-3-methylphenylboronic Acid, 2-Chloro-4-methylphenylboronic Acid, 2-Chloro-5-methylphenylboronic acid, 2-chloro-6-methylphenylboronic acid, 3-chloro-2-methylphenylboronic acid, 3-chloro-4-methylphenylboronic acid, 3-chloro-5- Methylphenylboronic acid, 3-chloro-6-methylphenylboronic acid, 4-chloro-3-methylphenylboronic acid,

2,3-bis (trifluoromethyl) phenylboronic acid, 2,4-bis (trifluoromethyl) phenylboronic acid, 2,5-bis (trifluoromethyl) phenylboronic acid, 3,4-bis (trifluoromethyl) Methyl) phenylboronic acid, 3,5-bis (trifluoromethyl) phenylboronic acid, 3,6-bis (trifluoromethyl) phenylboronic acid, 2-biphenylphenylboronic acid, 3-biphenylphenylboronic acid, 4- Biphenylphenylboronic acid, 2-fluoro-3- (trifluoromethyl) phenylboronic acid, 2-fluoro-4- (trifluoromethyl) phenylboronic acid, 2-fluoro-5- (trifluoromethyl) phenylboronic acid, 2-Fluoro-6- (trifluoromethyl) phenylboronic acid, 3-fluoro-2- (trifluoromethyl) phenylboronic acid, 3-fluoro-4- (trifluoromethyl) phenylboronic acid, 3-fluoro-5 -(Trifluoromethyl) phenylboronic acid, 3-fluoro-6- (trifluoromethyl) phenylboronic acid, 4-fluoro-3- (trifluoromethyl) phenylboronic acid, 2-chloro-3- (trifluoromethyl) ) Phenylboronic acid, 2-chloro-4- (trifluoromethyl) phenylboronic acid, 2-chloro-5- (trifluoromethyl) phenylboronic acid, 2-chloro-6- (trifluoromethyl) phenylboronic acid, 3-Chloro-2- (trifluoromethyl) phenylboronic acid, 3-chloro-4- (trifluoromethyl) phenylboronic acid, 3-chloro-5- (trifluoromethyl) phenylboronic acid, 3-chloro-6 -(Trifluoromethyl) phenylboronic acid, 4-chloro-3- (trifluoromethyl) phenylboronic acid, 2-fluoro-3-biphenylboronic acid, 2-fluoro-4-biphenylboronic acid, 2-fluoro-5 -Biphenylboronic acid, 2-fluoro-6-biphenylboronic acid, 3-fluoro-2-biphenylboronic acid, 3-fluoro-4-biphenylboronic acid, 3-fluoro-5-biphenylboronic acid, 3-fluoro-6 -Biphenylboronic acid, 4-fluoro-3-biphenylboronic acid.

Among the above specific examples, examples of the compound (A) include phenylboronic acid, 3,5-difluorophenylboronic acid, 4-vinylphenylboronic acid, 2-fluorophenylboronic acid, 3-fluorophenylboronic acid, and 4-fluoro. Phenylboronic acid, 2,3-difluorophenylboronic acid, 2,4-difluorophenylboronic acid, 2,5-difluorophenylboronic acid, 3,4-difluorophenylboronic acid, 3,6-difluorophenylboronic acid, 2 -Vinylphenylboronic acid or 3-vinylphenylboronic acid is particularly preferred.

The non-aqueous electrolytic solution of the present disclosure may contain only one type of specific boronic acid, or may contain two or more types of specific boronic acid.
The content of the specific boronic acid in the non-aqueous electrolyte solution of the present disclosure (total content in the case of two or more types) is 0.01% by mass to 2.0% by mass with respect to the total amount of the non-aqueous electrolyte solution. Preferably, 0.05% by mass to 1.5% by mass is more preferable, and 0.1% by mass to 1.0% by mass is particularly preferable.

Even when the non-aqueous electrolytic solution actually collected by disassembling the battery is analyzed, the amount of the specific boronic acid may be reduced as compared with the amount added to the non-aqueous electrolytic solution. Therefore, when the specific boronic acid can be detected even in a small amount in the non-aqueous electrolytic solution taken out from the battery, it is included in the range of the non-aqueous electrolytic solution of the present disclosure.
Further, even when the specific boronic acid cannot be detected in the non-aqueous electrolyte solution, the compound derived from the decomposition product of the specific boronic acid is detected in the non-aqueous electrolyte solution or in the coating film of the electrode. It is considered to be included in the range of non-aqueous electrolytes.
These treatments are the same for additives other than the specific boronic acid that can be contained in the non-aqueous electrolytic solution.

<Other additives>
The non-aqueous electrolyte solution of the present disclosure may contain other additives other than the specified boronic acid (also referred to as "other additives" in the present specification).
When the non-aqueous electrolytic solution of the present disclosure contains other additives, the other additives contained may be only one kind or two or more kinds.
Examples of other additives include carbonate compounds having a carbon-carbon unsaturated bond, fluorophosphate compounds, oxalate compounds, cyclic sulton compounds, compounds represented by the formula (C), and compounds represented by the formula (D). And at least one selected from the group consisting of cyclic sulfate ester compounds are preferred.

(Carbon-carbon unsaturated bond carbonate compound)
Examples of the carbonate compound having a carbon-carbon unsaturated bond include a chain such as methyl vinyl carbonate, ethyl vinyl carbonate, divinyl carbonate, methylpropynyl carbonate, ethylpropynyl carbonate, dipropynyl carbonate, methylphenyl carbonate, ethylphenyl carbonate, and diphenyl carbonate. Carbonates; vinylene carbonate, methylvinylene carbonate, 4,4-dimethylvinylene carbonate, 4,5-dimethylvinylene carbonate, vinylethylene carbonate, 4,4-divinylethylene carbonate, 4,5-divinylethylene carbonate, ethynylethylene carbonate, Cyclic carbonates such as 4,4-dietinylethylene carbonate, 4,5-dietinylethylene carbonate, propynylethylene carbonate, 4,4-dipropynylethylene carbonate, and 4,5-dipropynylethylene carbonate; and the like. Of these, methylphenyl carbonate, ethylphenyl carbonate, diphenyl carbonate, vinylene carbonate, vinylethylene carbonate, 4,5-divinylethylene carbonate, and 4,5-divinylethylene carbonate are preferable, and vinylene carbonate, more preferably. It is vinylethylene carbonate.

(Fluorophosphoric acid compound)
Examples of the fluorophosphate compound include lithium difluorophosphate, lithium monofluorophosphate, difluorophosphate, monofluorophosphate, methyl difluorophosphate, ethyl difluorophosphate, dimethyl fluorophosphate, diethyl fluorophosphate and the like. .. Of these, lithium difluorophosphate and lithium monofluorophosphate are preferable.

(Oxalate compound)
Examples of the oxalate compound include lithium difluorobis (oxalate) phosphate, lithium tetrafluoro (oxalate) phosphate, lithium tris (oxalate) phosphate, lithium difluoro (oxalate) borate, and lithium bis (oxalate) borate. .. Of these, lithium difluorobis (oxalate) phosphate, lithium tetrafluoro (oxalate) phosphate, and lithium bis (oxalate) borate are preferable.

(Cyclic sultone compound)
Cyclic sultone compounds include 1,3-propane sultone, 1,4-butane sultone, 1,3-propensultone, 1-methyl-1,3-propensultone, 2-methyl-1,3-propensultone, 3-. Examples thereof include sultones such as methyl-1,3-propensultone. Of these, 1,3-propane sultone and 1,3-propene sultone are preferable.

(Compound represented by formula (C))

In formula (C), R ¹ is a hydrocarbon group having 1 to 6 carbon atoms substituted with at least one fluorine atom, a hydrocarbon oxy group having 1 to 6 carbon atoms substituted with at least one fluorine atom, or Represents a fluorine atom.

In the formula (C), ^{as the hydrocarbon group in R 1} , an alkyl group or an alkenyl group is preferable, and an alkyl group is more preferable.
In the formula (C), the ^{hydrocarbon group in R 1} may be substituted with at least one fluorine atom, but is preferably a perfluorohydrocarbon group.
Wherein (C), the carbon number of the hydrocarbon group for ^{R 1} is 1 to 3, more preferably 1 or 2, 1 is particularly preferred.

In the formula (C), ^{as the hydrocarbon oxy group in R 1} , an alkoxy group or an alkenyloxy group is preferable, and an alkoxy group is more preferable.
In the formula (C), the ^{hydrocarbon oxy group in R 1} may be substituted with at least one fluorine atom, but is preferably a perfluorohydrocarbon oxy group.
In the formula (C), the ^{number of carbon atoms of the hydrocarbon oxy group in R 1} is preferably 1 to 3, more preferably 1 or 2, and particularly preferably 1.

Wherein (C), as the R ^1, at least one hydrocarbon group having 1 to 6 carbon atoms substituted with fluorine atoms are preferable, an alkyl group having 1 to 6 carbon atoms which is substituted with at least one fluorine atom More preferably, a perfluoroalkyl group having 1 to 6 carbon atoms is further preferable, a perfluoromethyl group (also known as a trifluoromethyl group) or a perfluoroethyl group (also known as a pentafluoroethyl group) is further preferable, and a perfluoromethyl group is more preferable. (Also known as: trifluoromethyl group) is particularly preferable.

As the compound represented by the formula (C), lithium trifluoromethylsulfonate or lithium pentafluoroethylsulfonate is preferable, and lithium trifluoromethylsulfonate is particularly preferable.

(Compound represented by formula (D))

In formula (D), R ¹ represents a hydrocarbon group having 1 to 6 carbon atoms which may be substituted with at least one fluorine atom, or a fluorine atom.

Wherein (D), examples of the hydrocarbon group of R ^1, an alkyl group or alkenyl group and more preferably an alkyl group.
In the formula (D), the ^{hydrocarbon group in R 1} may be substituted with at least one fluorine atom, but is preferably a perfluorohydrocarbon group.
Wherein (D), the carbon number of the hydrocarbon group for ^{R 1} is 1 to 3, more preferably 1 or 2, 1 is particularly preferred.

Wherein (D), as the R ^1, an alkyl group having 1 to 6 carbon atoms are preferable be substituted by fluorine atoms, more preferably an alkyl group having 1 to 3 carbon atoms substituted with fluorine atoms, Methyl, ethyl, propyl, or trifluoromethyl groups are particularly preferred.

Examples of the compound represented by the formula (D) include methanesulfonyl fluoride, ethanesulfonyl fluoride, propanesulfonyl fluoride, 2-propanesulfonyl fluoride, butanesulfonyl fluoride, 2-butanesulfonyl fluoride, and hexanesulfonyl fluoride. , Trifluoromethanesulfonyl fluoride, perfluoroethanesulfonyl fluoride, perfluoropropanesulfonyl fluoride, perfluorobutane sulfonyl fluoride, ethanesulfonyl fluoride, 1-propene-1-sulfonyl fluoride, 2-propen-1-sulfonyl Examples include fluoride.
As the compound represented by the formula (D), methanesulfonyl fluoride is particularly preferable.

(Cyclic sulfate compound)
As the cyclic sulfuric acid ester compound, a compound represented by the following formula (I) is preferable.

In formula (I), R ¹ and R ² are independently represented by a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a phenyl group, a group represented by formula (II), or a group represented by formula (III). It represents a group, or represents a group in which R ¹ and R ² are united to form a benzene ring or a cyclohexyl ring together with a carbon atom to ^{which R 1} is bonded and a carbon atom to which R ^{2 is bonded.}
In formula (II), R ³ is represented by a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkyl halide group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or the formula (IV). Represents a group. The wavy lines in equations (II), (III), and (IV) represent the coupling positions.
When the compound represented by the formula (I) contains two groups represented by the formula (II), the groups represented by the two formulas (II) are different from each other even if they are the same. May be good.

Specific examples of the "halogen atom" in the formula (II) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
As the halogen atom, a fluorine atom is preferable.

In the formulas (I) and (II), the "alkyl group having 1 to 6 carbon atoms" is a linear or branched alkyl group having 1 or more and 6 or less carbon atoms, and is a methyl group, an ethyl group, or a propyl group. Group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, 2-methylbutyl group, 1-methylpentyl group, neopentyl group, 1-ethylpropyl group, hexyl group, 3,3 -A specific example is a dimethylbutyl group.
As the alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 3 carbon atoms is more preferable.

In the formula (II), the "alkyl halide group having 1 to 6 carbon atoms" is a linear or branched alkyl halide group having 1 to 6 carbon atoms, and is a fluoromethyl group, a difluoromethyl group, or the like. Trifluoromethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, perfluoroisopropyl group, perfluoroisobutyl group , Chloromethyl group, chloroethyl group, chloropropyl group, bromomethyl group, bromoethyl group, bromopropyl group, methyl iodide group, ethyl iodide group, propyl iodide group and the like can be mentioned as specific examples.
As the alkyl halide group having 1 to 6 carbon atoms, an alkyl halide group having 1 to 3 carbon atoms is more preferable.

In the formula (II), the "alkoxy group having 1 to 6 carbon atoms" is a linear or branched alkoxy group having 1 or more and 6 or less carbon atoms, and is a methoxy group, an ethoxy group, a propoxy group, or an isopropoxy. Group, butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group, 2-methylbutoxy group, 1-methylpentyloxy group, neopentyloxy group, 1-ethylpropoxy group, hexyloxy group, Specific examples include 3,3-dimethylbutoxy groups.
As the alkoxy group having 1 to 6 carbon atoms, an alkoxy group having 1 to 3 carbon atoms is more preferable.

In a preferred embodiment of the formula (I), R ¹ is a group represented by the formula (II) (in the formula (II), R ³ is a fluorine atom, an alkyl group having 1 to 3 carbon atoms, and 1 to 3 carbon atoms. The alkyl halide group, the alkoxy group having 1 to 3 carbon atoms, or the group represented by the formula (IV) is preferable.) Or the group represented by the formula (III), and R ² is , A hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a group represented by the formula (II), or a group represented by the formula (III), or R ¹ and R ² are integrated. This is a group that forms a benzene ring or a cyclohexyl ring together with a carbon atom ^{to which R 1} is bonded and a carbon atom to which R ^{2 is bonded.}

^{R 2} in the formula (I) is more preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, and a group represented by the formula (II) (in the formula (II), R ³ is a fluorine atom and carbon. It is more preferably an alkyl group having the number 1 to 3, an alkyl halide group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a group represented by the formula (IV)), or the formula. It is a group represented by (III), more preferably a hydrogen atom or a methyl group.

^{When R 1} in the formula (I) is a group represented by the formula (II), R ³ in the formula (II) is a halogen atom, an alkyl group having 1 to 6 carbon atoms, and a carbon number of 1 as described above. 6 halogenated alkyl group, an alkoxy group having 1 to 6 carbon atoms, or a group represented by formula (IV), is more preferably R ^3, a fluorine atom, an alkyl group having 1 to 3 carbon atoms, An alkyl halide group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a group represented by the formula (IV), more preferably a fluorine atom, a methyl group, an ethyl group, or a trifluoromethyl group. A group, a methoxy group, an ethoxy group, or a group represented by the formula (IV).
^{When R 2} in the formula (I) is a group represented by the formula (II), for ^{a preferable range of R 3 in the formula (II), R 1} in the formula (I) is the formula (II). the same as the preferred ranges of R ³ in the case of a group represented.

As a preferable combination ^{of R 1} and R ² in the formula (I) ^{, R 1} is a group represented by the formula (II) (in the formula (II), R ³ is a fluorine atom and an alkyl group having 1 to 3 carbon atoms). , An alkyl halide group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a group represented by the formula (IV)), or a group represented by the formula (III). , R ² is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, and a group represented by the formula (II) (in the formula (II), R ³ is a fluorine atom, an alkyl group having 1 to 3 carbon atoms, and the number of carbon atoms. It is preferably an alkyl halide group of 1 to 3, an alkoxy group having 1 to 3 carbon atoms, or a group represented by the formula (IV)), or a combination of groups represented by the formula (III). is there.
As a more preferable combination ^{of R 1} and R ² in the formula (I) ^{, R 1} is a group represented by the formula (II) (in the formula (II), R ³ is a fluorine atom, a methyl group, an ethyl group, a trifluoro). A methyl group, a methoxy group, an ethoxy group, or a group represented by the formula (IV)) or a group represented by the formula (III), in which R ² is a hydrogen atom or a methyl group. is there.

For the compound represented by the formula (I), the description in paragraphs 0040 to 0070 of International Publication No. 2012/053644 can be referred to as appropriate.

Other additives mentioned above include vinylene carbonate, vinylethylene carbonate, lithium monofluorophosphate, lithium difluorophosphate, lithium bis (oxalate) borate, 1,3-propane sultone, 1,3-propensultone, and trifluoro. It is particularly preferable that it is at least one selected from the group consisting of lithium methylsulfonate, methanesulfonyl fluoride, and the compound represented by the formula (I).

When the non-aqueous electrolytic solution of the present disclosure contains other additives, the other additives contained may be only one type or two or more types.
When the non-aqueous electrolyte solution of the present disclosure contains other additives, the content thereof (the total content when there are two or more kinds) is not particularly limited, but the effect of the present disclosure is more effective. From the viewpoint of playing, it is preferably 0.001% by mass to 10% by mass, more preferably 0.05% by mass to 5% by mass, and 0.1% by mass, based on the total amount of the non-aqueous electrolyte solution. It is more preferably% to 4% by mass, further preferably 0.1% by mass to 2% by mass, and particularly preferably 0.1% by mass to 1% by mass.

<Electrolyte>
The non-aqueous electrolyte solution of the present disclosure generally contains an electrolyte.
As the electrolyte, a lithium salt other than the lithium salt contained in the examples of the other additives (hereinafter, also referred to as “specific lithium salt”) is preferable.
The specific lithium salt as the electrolyte may be only one kind or two or more kinds.

Examples of specific lithium _{salts, LiPF 6, LiBF 4, LiClO} 4, LiAsF 6, Li 2 SiF 6, LiPF n [C k F (2k + 1)] (6-n) (n = 1~5, k = Lithium salts such as (integer of 1 to 8) can be mentioned.
Further, a lithium salt represented by the following general formula can also be used.

LiC (SO ₂ R ²⁷ ) (SO ₂ R ²⁸ ) (SO ₂ R ²⁹ ), LiN (SO ₂ OR ³⁰ ) (SO ₂ OR ³¹ ), LiN (SO ₂ R ³² ) (SO ₂ R ³³ ) (here R ^{27 to} R ³³ may be the same or different from each other and are perfluoroalkyl groups having 1 to 8 carbon atoms). These electrolytes may be used alone or in combination of two or more.

The specific lithium salt preferably contains at least one of _{LiPF 6} and LiBF ₄ , and more preferably contains _{LiPF 6.}
If a particular lithium salt containing LiPF _6, the proportion of LiPF ₆ occupied in particular the lithium salt is preferably from 10 wt% to 100 wt%, more preferably from 50 wt% to 100 wt%, 70 wt% to 100 wt% Is particularly preferable.

The concentration of the electrolyte in the non-aqueous electrolyte solution is preferably 0.1 mol / L to 3 mol / L, and more preferably 0.5 mol / L to 2 mol / L.

The non-aqueous electrolyte solution of the present disclosure is not only suitable as a non-aqueous electrolyte solution for a lithium secondary battery, but also a non-aqueous electrolyte solution for a primary battery, a non-aqueous electrolyte solution for an electrochemical capacitor, and an electric double layer capacitor. , Can also be used as an electrolytic solution for aluminum electrolytic capacitors.

[Lithium secondary battery]
The lithium secondary battery of the present disclosure includes a positive electrode, a negative electrode, and a non-aqueous electrolytic solution of the present disclosure.

(Negative electrode)
The negative electrode may include a negative electrode active material and a negative electrode current collector.
Examples of the negative electrode active material in the negative electrode include metallic lithium, lithium-containing alloys, metals or alloys that can be alloyed with lithium, oxides that can be doped / dedoped with lithium ions, and lithium ions that can be doped / dedoped. At least one selected from the group consisting of transition metal nitridants and carbon materials capable of doping and dedoping lithium ions (may be used alone, or a mixture containing two or more of these may be used. Good) can be used.
Examples of the metal or alloy that can be alloyed with lithium (or lithium ion) include silicon, a silicon alloy, tin, and a tin alloy. Further, lithium titanate may be used.
Among these, a carbon material capable of doping and dedoping lithium ions is preferable. Examples of such carbon materials include carbon black, activated carbon, graphite materials (artificial graphite, natural graphite), amorphous carbon materials, and the like. The form of the carbon material may be fibrous, spherical, potato-like, or flake-like.

Specific examples of the amorphous carbon material include hard carbon, coke, mesocarbon microbeads (MCMB) fired at 1500 ° C. or lower, and mesophase pitch carbon fiber (MCF).
Examples of the graphite material include natural graphite and artificial graphite. As the artificial graphite, graphitized MCMB, graphitized MCF and the like are used. Further, as the graphite material, a material containing boron or the like can also be used. Further, as the graphite material, a material coated with a metal such as gold, platinum, silver, copper or tin, a material coated with amorphous carbon, or a mixture of amorphous carbon and graphite can also be used.

These carbon materials may be used alone or in admixture of two or more.
As the carbon material, a carbon material having a surface spacing d (002) of the (002) plane measured by X-ray analysis of 0.340 nm or less is particularly preferable. Further, as the carbon material, graphite having a true density of 1.70 g / cm ³ or more or a highly crystalline carbon material having a property close to that of graphite is also preferable. When the carbon material as described above is used, the energy density of the battery can be further increased.

The material of the negative electrode current collector in the negative electrode is not particularly limited, and any known material can be used.
Specific examples of the negative electrode current collector include metal materials such as copper, nickel, stainless steel, and nickel-plated steel. Of these, copper is particularly preferable from the viewpoint of ease of processing.

(Positive electrode)
The positive electrode may include a positive electrode active material and a positive electrode current collector.
Examples of the positive electrode active material in the positive electrode include transition metal oxides or transition metal sulfides such _{as MoS 2} , TiS ₂ , MnO ₂ , and V ₂ O _{5 , LiCoO 2} , LiMnO ₂ , LiMn ₂ O ₄ , LiNiO ₂ , and LiNi _X Co. _(1-X) O ₂ [0 <X <1], _{Li 1 + α} Me _1-α O _{2 having an α-NaFeO type 2} crystal structure (Me is a transition metal element containing Mn, Ni and Co, 1.0. ≦ (1 + α) / ( 1-α) ≦ 1.6), LiNi x Co y Mn z O 2 [x + y + z = 1,0 < x <1,0 <y <1,0 <z <1 ] (e.g., LiNi _0.33 Co _0.33 Mn _0.33 O ₂ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ etc.), LiFePO ₄ , LiMnPO ₄ and other composite oxides consisting of lithium and transition metals, Examples thereof include conductive polymer materials such as polyaniline, polythiophene, polypyrrole, polyacetylene, polyacene, dimercaptothiaizole, and polyaniline complex. Among these, a composite oxide composed of lithium and a transition metal is particularly preferable. When the negative electrode is a lithium metal or a lithium alloy, a carbon material can also be used as the positive electrode. Further, as the positive electrode, a mixture of a composite oxide of lithium and a transition metal and a carbon material can also be used.
The positive electrode active material may be used alone or in combination of two or more. When the positive electrode active material has insufficient conductivity, it can be used together with a conductive auxiliary agent to form a positive electrode. Examples of the conductive auxiliary agent include carbon materials such as carbon black, amorphous whiskers, and graphite.

The material of the positive electrode current collector in the positive electrode is not particularly limited, and any known material can be used.
Specific examples of the positive electrode current collector include metal materials such as aluminum, aluminum alloy, stainless steel, nickel, titanium, and tantalum; carbon materials such as carbon cloth and carbon paper; and the like.

(Separator)
The lithium secondary battery of the present disclosure preferably contains a separator between the negative electrode and the positive electrode.
The separator is a membrane that electrically insulates the positive electrode and the negative electrode and allows lithium ions to pass through, and examples thereof include a porous membrane and a polymer electrolyte.
As the porous film, a microporous polymer film is preferably used, and examples of the material include polyolefin, polyimide, polyvinylidene fluoride, polyester and the like.
In particular, porous polyolefin is preferable, and specifically, a porous polyethylene film, a porous polypropylene film, or a multilayer film of a porous polyethylene film and a polypropylene film can be exemplified. The porous polyolefin film may be coated with another resin having excellent thermal stability.
Examples of the polymer electrolyte include a polymer in which a lithium salt is dissolved, a polymer inflated with an electrolytic solution, and the like.
The non-aqueous electrolyte solution of the present disclosure may be used for the purpose of swelling a polymer to obtain a polymer electrolyte.

(Battery configuration)
The lithium secondary battery of the present disclosure can take various known shapes, and can be formed into a cylindrical type, a coin type, a square type, a laminated type, a film type, or any other shape.
The basic structure of the battery is the same regardless of the shape, and the design can be changed according to the purpose.

An example of the lithium secondary battery of the present disclosure is a laminated battery.
FIG. 1 is a schematic perspective view showing an example of a laminated battery which is an example of the lithium secondary battery of the present disclosure, and FIG. 2 is a thickness of a laminated electrode body housed in the laminated battery shown in FIG. It is a schematic sectional view of a direction.
The laminated battery shown in FIG. 1 contains a non-aqueous electrolytic solution (not shown in FIG. 1) and a laminated electrode body (not shown in FIG. 1), and the peripheral edge thereof is sealed. A laminated exterior body 1 whose inside is hermetically sealed is provided. As the laminated exterior body 1, for example, a laminated exterior body made of aluminum is used.
As shown in FIG. 2, the laminated electrode body housed in the laminated exterior body 1 is a laminated body in which a positive electrode plate 5 and a negative electrode plate 6 are alternately laminated via a separator 7, and a laminated body of the laminated body. A separator 8 that surrounds the periphery is provided. The positive electrode plate 5, the negative electrode plate 6, the separator 7, and the separator 8 are impregnated with the non-aqueous electrolytic solution of the present disclosure.
The plurality of positive electrode plates 5 in the laminated electrode body are all electrically connected to the positive electrode terminal 2 via the positive electrode tab (not shown), and a part of the positive electrode terminal 2 is the laminated exterior body 1. It protrudes outward from the peripheral end (Fig. 1). A portion of the peripheral end of the laminated exterior body 1 on which the positive electrode terminal 2 protrudes is sealed with an insulating seal 4.
Similarly, the plurality of negative electrode plates 6 in the laminated electrode body are all electrically connected to the negative electrode terminal 3 via the negative electrode tab (not shown), and a part of the negative electrode terminal 3 is the laminated exterior. It protrudes outward from the peripheral end of the body 1 (FIG. 1). A portion of the peripheral end of the laminated exterior body 1 from which the negative electrode terminal 3 protrudes is sealed with an insulating seal 4.
In the laminated battery according to the above example, the number of positive electrode plates 5 is 5 and the number of negative electrode plates 6 is 6, and the positive electrode plate 5 and the negative electrode plate 6 are located on both sides of the battery via the separator 7. The outer layers are all laminated so as to be the negative electrode plate 6.
However, it goes without saying that the number of positive electrode plates, the number of negative electrode plates, and the arrangement of the laminated battery are not limited to this example, and various changes may be made. For example, the laminated electrode body housed in the laminated exterior body 1 may be a laminated electrode body in which one positive electrode plate 5 and one negative electrode plate 6 are laminated via one separator 7. Good.

Another example of the lithium secondary battery of the present disclosure is a coin-type battery.
FIG. 3 is a schematic perspective view showing an example of a coin-type battery, which is another example of the lithium secondary battery of the present disclosure.
In the coin-type battery shown in FIG. 3, a disk-shaped negative electrode 12, a separator 15 injected with a non-aqueous electrolyte solution, a disk-shaped positive electrode 11, and, if necessary, spacer plates 17 and 18 made of stainless steel or aluminum are arranged in this order. In a laminated state, it is stored between the positive electrode can 13 (hereinafter, also referred to as “battery can”) and the sealing plate 14 (hereinafter, also referred to as “battery can lid”). The positive electrode can 13 and the sealing plate 14 are caulked and sealed via the gasket 16.
In this example, the non-aqueous electrolytic solution of the present disclosure can be used as the non-aqueous electrolytic solution to be injected into the separator 15.

The lithium secondary battery of the present disclosure is obtained by charging / discharging a lithium secondary battery (lithium secondary battery before charging / discharging) containing a negative electrode, a positive electrode, and the non-aqueous electrolyte solution of the present disclosure. It may be a lithium secondary battery.
That is, as the lithium secondary battery of the present disclosure, first, a lithium secondary battery before charging / discharging containing a negative electrode, a positive electrode, and the non-aqueous electrolyte solution of the present disclosure is prepared, and then the lithium secondary battery before charging / discharging is prepared. It may be a lithium secondary battery (charged / discharged lithium secondary battery) manufactured by charging / discharging the lithium secondary battery one or more times.

The use of the lithium secondary battery of the present disclosure is not particularly limited, and it can be used for various known uses. For example, laptops, mobile computers, mobile phones, headphone stereos, video movies, LCD TVs, handy cleaners, electronic organizers, calculators, radios, backup power supplies, motors, automobiles, electric vehicles, bikes, electric bikes, bicycles, electric It can be widely used regardless of whether it is a small portable device or a large device such as a bicycle, a lighting device, a game machine, a clock, an electric tool, or a camera.

Hereinafter, examples of the present disclosure will be shown, but the present disclosure is not limited to the following examples.
In the following examples, the "addition amount" represents the content with respect to the total amount of the non-aqueous electrolytic solution finally obtained.

[Example 1]
A laminated battery (test battery), which is a lithium secondary battery, was produced by the following procedure.

<Manufacturing of negative electrode>
98 parts by mass of artificial graphite, 1 part by mass of carboxymethyl cellulose and 1 part by mass of SBR latex were kneaded with an aqueous solvent to prepare a paste-like negative electrode mixture slurry.
Next, this negative electrode mixture slurry is applied to a negative electrode current collector made of a strip-shaped copper foil having a thickness of 10 μm, dried, and then compressed by a roll press to form a sheet composed of the negative electrode current collector and the negative electrode active material layer. A negative electrode was obtained. At this time, the coating density of the negative electrode active material layer was 12 mg / cm ² , and the packing density was 1.5 g / ml.

<Preparation of positive electrode>
97 parts by mass of LiCoO ₂ , 1.8 parts by mass of acetylene black and 1.2 parts by mass of polyvinylidene fluoride were kneaded with N-methylpyrrolidinone as a solvent to prepare a paste-like positive electrode mixture slurry.
Next, this positive electrode mixture slurry is applied to a positive electrode current collector of a strip-shaped aluminum foil having a thickness of 20 μm, dried, and then compressed by a roll press to form a sheet-shaped positive electrode composed of a positive electrode current collector and a positive electrode active material layer. Got At this time, the coating density of the positive electrode active material layer was 25 mg / cm ² , and the packing density was 3.6 g / ml.

<Preparation of non-aqueous electrolyte solution>
A non-aqueous solvent was obtained by mixing ethylene carbonate (EC), fluoroethylene carbonate (FEC), and ethyl methyl carbonate (EMC) in a volume ratio of 25: 5: 70 (EC: FEC: EMC). ..
Here, fluoroethylene carbonate (FEC) is an example of fluorinated cyclic carbonate, and the content of fluorinated cyclic carbonate (FEC) is 5% by volume with respect to the total amount of the non-aqueous solvent.
_{LiPF 6} as an electrolyte was dissolved in the obtained non-aqueous solvent so that the electrolyte concentration in the finally obtained non-aqueous electrolyte solution was 1.2 mol / liter.
Phenylboronic acid (PHBA) (addition amount: 0.5% by mass) as a specific boronic acid was added to the solution obtained above to obtain a non-aqueous electrolytic solution.

<Manufacturing of laminated batteries>
The sheet-shaped negative electrode was punched with a length of 42 mm and a width of 31 mm, and the sheet-shaped positive electrode was punched with a length of 40 mm and a width of 29 mm, respectively, to obtain a rectangular negative electrode plate and a rectangular positive electrode plate, respectively. Further, a microporous polyethylene film having a thickness of 20 μm was punched into a length of 45 mm and a width of 35 mm to obtain a rectangular separator.
Next, the negative electrode tab was attached to the negative electrode plate, and the positive electrode tab was attached to the positive electrode plate.
A negative electrode plate to which the negative electrode tab was attached and a positive electrode plate to which the positive electrode tab was attached were laminated with the negative electrode tab and the positive electrode tab arranged on the same side via a separator to obtain a laminated electrode body.
Next, the laminated electrode body was housed in an aluminum laminated outer body, and one side of the laminated outer body on the side where the positive electrode tab and the negative electrode tab were arranged was heat-sealed. At this time, a part of the positive electrode tab and a part of the negative electrode tab were made to protrude from the peripheral end portion of the laminated exterior body. The protruding portions of the positive electrode tab and the negative electrode tab were each sealed with an insulating seal.
Next, two of the remaining three sides of the laminated exterior were heat-sealed.
Next, 250 μL of the non-aqueous electrolytic solution is injected into the laminated exterior from one side of the laminated exterior that is not heat-sealed, and the non-aqueous electrolytic solution is applied to each positive electrode plate, each negative electrode plate, and each separator. Impregnated. Next, the laminated exterior body was sealed by heat-sealing one side that was not heat-sealed.
From the above, a laminated battery (test battery) was obtained.

<Amount of change in battery volume due to high temperature storage>
In order to evaluate the volume change when the fully charged battery is stored at a high temperature, the volume change amount of the battery due to the high temperature storage was measured as follows.
The volume of the laminated battery produced above was measured and used as the "volume before high temperature storage".
After the laminated battery whose volume was measured before storage at high temperature was initially charged and discharged, it was charged at a constant voltage of 4.2 V to bring it into a fully charged state. Here, the initial charge / discharge was performed by charging to 4.2 V at 0.5 C and then discharging to 3 V at 0.5 C.
Next, the fully charged laminated battery was stored in a constant temperature bath at 60 ° C. for 30 days (hereinafter, this operation is also referred to as “high temperature storage”).
Next, the volume of the laminated battery after high temperature storage was measured and used as "volume after high temperature storage". Based on the volume before high-temperature storage and the volume after high-temperature storage, the amount of volume change due to high-temperature storage was determined by the following formula.

Battery volume change due to high temperature storage (cm ³ )
= Volume after high temperature storage (cm ³ ) -Volume before high temperature storage (cm ³ )

In Comparative Example 1 described later, the amount of change in the volume of the battery due to high temperature storage was determined in the same manner.

Table 1 shows the amount of change in battery volume due to high temperature storage.
In Table 1, the amount of change in the volume of the battery due to high temperature storage is represented by a relative value (%) when the result of Comparative Example 1 is taken as 100%.
The smaller the value of the volume change of the battery due to high temperature storage, the more the volume change when the fully charged battery is stored at high temperature is suppressed.

[Comparative Examples 1 and 2]
In the preparation of the non-aqueous electrolyte solution, the same operation as in Example 1 was carried out except that the type and volume ratio of the non-aqueous solvent were changed as shown in Table 1.
The results are shown in Table 1.

As shown in Table 1, in Example 1 using a non-aqueous electrolytic solution containing a specific boric acid and a non-aqueous solvent having a fluorinated cyclic carbonate content of more than 0% by volume and 8% by volume or less, The amount of change in the volume of the battery due to high-temperature storage was reduced (that is, the volume change when the fully charged battery was stored at high temperature was suppressed).
For Example 1
Comparative Example 1 using a non-aqueous electrolytic solution containing a specific boronic acid and not containing a fluorinated cyclic carbonate as a non-aqueous solvent, and
In Comparative Example 2 using a non-aqueous electrolytic solution containing a specific boronic acid and a fluorinated cyclic carbonate as a non-aqueous solvent and having a fluorinated cyclic carbonate content of more than 8% by volume based on the total amount of the non-aqueous solvent. ,
In both cases, the amount of change in battery volume due to high-temperature storage increased.

<Initial discharge capacity>
For the laminated battery of Example 1, the discharge capacity when discharged to 3V at 0.5C in the initial charge / discharge (operation of charging to 4.2V at 0.5C and then discharging to 3V at 0.5C) is measured. Then, the initial discharge capacity (mAh) was used.
The initial discharge capacity (mAh) was measured in the same manner for the laminated battery of Comparative Example 3 below.

Table 2 shows the initial discharge capacity.
In Table 2, the initial discharge capacity of Example 1 is represented by a relative value (%) when the initial discharge capacity of Comparative Example 3 is 100%.

[Comparative Example 3]
A laminated battery was produced in the same manner as in Example 1 except that the specific boronic acid was not added in the preparation of the non-aqueous electrolytic solution.
The initial discharge capacity of the obtained laminated battery was measured in the same manner as in Example 1.
The results are shown in Table 2.

As shown in Table 2, a non-aqueous electrolyte solution containing the specific boronic acid and a non-aqueous solvent in which the content of the fluorinated cyclic carbonate with respect to the total amount of the non-aqueous solvent is more than 0% by volume and 8% by volume or less is used. It can be seen that the initial discharge capacity is larger than that in the case (Example 1) when a non-aqueous electrolyte solution containing no specific boronic acid is used (Comparative Example 3).

1 Laminated exterior 2 Positive electrode terminal 3 Negative electrode terminal 4 Insulation seal 5 Positive electrode plate 6 Negative electrode plate 7, 8 Separator 11 Positive electrode 12 Negative electrode 13 Positive electrode can 14 Seal plate 15 Separator 16 Gasket 17, 18 Spacer plate

Claims (5)

Boronic acid having an aromatic hydrocarbon group and
A non-aqueous solvent in which the content of the fluorinated cyclic carbonate with respect to the total amount of the non-aqueous solvent is more than 0% by volume and 8% by volume or less,
A battery for a non-aqueous electrolyte containing,
A non-aqueous electrolytic solution for a battery in which the boronic acid is a compound (A) represented by the following formula (A).
R ¹ B (OH) ₂ ... (A)
[In formula (A), R ¹ represents a phenyl group that may be substituted with at least one substituent selected from the group consisting of halogen atoms and hydrocarbon groups having 1 to 6 carbon atoms. ] The non-aqueous battery for a battery according to claim 1, ^{wherein R 1} in the formula (A) represents a phenyl group which may be substituted with at least one substituent selected from the group consisting of a fluorine atom and a vinyl group. Electrolyte. The non-aqueous electrolytic solution for a battery according to claim 1 or 2, wherein the compound (A) represented by the formula (A) is phenylboronic acid. The non-water for batteries according to any one of claims 1 to 3, wherein the content of the boronic acid is 0.01% by mass to 2.0% by mass with respect to the total amount of the non-aqueous electrolyte solution for batteries. Electrolyte. With the positive electrode
Metallic lithium, lithium-containing alloys, metals or alloys that can be alloyed with lithium, oxides that can be doped and dedoped with lithium ions, transition metal nitrogen compounds that can be doped and dedoped with lithium ions, and lithium. A negative electrode containing at least one selected from the group consisting of carbon materials capable of doping and dedoping ions as a negative electrode active material, and a negative electrode.
The non-aqueous electrolyte solution for a battery according to any one of claims 1 to 4.
Lithium secondary battery including.

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