JP7301557B2 - NON-AQUEOUS ELECTROLYTE AND ENERGY DEVICE USING THE SAME - Google Patents

Description

TECHNICAL FIELD The present invention relates to a non-aqueous electrolytic solution and an energy device using the same.

In a wide range of applications, from so-called consumer power sources such as mobile phones and notebook computers, to on-board power sources for driving automobiles and large stationary power sources, non-aqueous electrolyte secondary batteries, electric double layer capacitors, lithium ion capacitors, etc. energy devices using non-aqueous electrolytes have been put into practical use. However, in recent years, the demand for higher performance energy devices has been increasing. Especially in non-aqueous electrolyte secondary batteries, battery characteristics such as input/output characteristics, cycle characteristics, durability such as storage characteristics, etc. It is required to achieve various characteristics such as safety at a high level.
Until now, as a means to improve the input/output characteristics of non-aqueous electrolyte secondary batteries, capacity during endurance tests such as cycle characteristics and storage characteristics, battery swelling, positive electrode metal elution, and safety A large number of technologies have been investigated for various battery components including active materials and non-aqueous electrolytes.

For example, in Patent Document 1, N(SO ₂ F) ₂ anions and fluorine-containing inorganic anions are contained, and the mixing ratio of N(SO ₂ F) ₂ anions to the total amount of anions in the non-aqueous electrolyte is 50 mol%. A technique for providing a non-aqueous electrolyte battery with excellent output characteristics is disclosed as follows.

Further, in Patent Document 2, by using a non-aqueous organic solvent containing propylene carbonate and a non-aqueous electrolytic solution containing lithium bisfluorosulfonylimide, low-temperature output characteristics, high-temperature cycle characteristics, output characteristics after high-temperature storage, capacity Techniques for providing a non-aqueous electrolyte battery with improved characteristics and battery swelling are disclosed.

In addition, Patent Document 3 discloses a technique for providing an electrolyte for a lithium secondary battery that causes less decomposition on the carbon negative electrode with the progress of charge-discharge cycles by using a non-aqueous electrolyte containing a cyclic sulfate. ing.

Further, in Patent Document 4, a lithium-nickel composite oxide having a layered structure is included as a positive electrode active material, and the electrolyte has a methylene disulfone structure (R ¹ -SO ₂ -C(R ² R ³ ) ₂ -SO ₂ - R ⁴ ) is disclosed to obtain a lithium secondary battery having excellent properties such as energy density and electromotive force, as well as excellent cycle life and storage stability.

Further, in Patent Document 5, by using a non-aqueous electrolyte containing unsaturated sultone, the decomposition reaction of the solvent on the negative electrode is suppressed, the capacity decrease of the battery during high-temperature storage, gas generation is suppressed, and Techniques for suppressing deterioration of battery load characteristics have been disclosed.

Further, Patent Document 6 describes a non-aqueous electrolytic solution containing LiPF ₆ and fluorosulfonate, in which the molar content of FSO ₃ with respect to the molar content of PF ₆ is 0.001 to 1.2. provides a non-aqueous electrolyte secondary battery that has improved initial charge capacity, input/output characteristics and impedance characteristics, and maintains not only initial battery characteristics and durability, but also high input/output characteristics and impedance characteristics even after endurance. A technique for doing so is disclosed.

JP 2009-129797 A Japanese Patent Publication No. 2015-509271 JP-A-10-189042 JP 2006-156314 A JP-A-2002-329528 JP 2011-187440 A

As described above, the demand for higher performance non-aqueous electrolyte secondary batteries in recent years has increased, and further improvements in the performance of non-aqueous electrolyte secondary batteries, that is, input/output characteristics, cycle characteristics, and storage characteristics. Improvements in capacity, battery swelling, positive electrode metal elution, and safety during endurance tests are required.
However, the compounds described in Patent Documents 1 to 6 and the non-aqueous electrolyte batteries using the electrolytes using the compounds are still far from sufficiently improving the above problems.

The reason for this is not completely clarified at present, but is presumed as follows. That is, in order to improve the charge transfer reaction rate of lithium ions, it is necessary to suppress side reactions such as solvent decomposition on the surface of the electrode and promote permeation of lithium ions. However, with only the techniques described in Patent Documents 1 to 6, the balance between the two is insufficient, and as a result, both input/output characteristics and durability cannot be improved to the maximum.
In particular, in the recent batteries that have reduced the amount of electrolyte injected in order to achieve higher energy densities, side reactions tend to occur if there are few additives that reduce the reactivity of the electrode surface, resulting in a decrease in input/output characteristics. become prominent.

The present invention has been made in view of such background art, and an object thereof is to provide a non-aqueous electrolytic solution that is excellent in input/output characteristics and durability.

As a result of intensive studies to solve the above problems, the inventors of the present invention have found that a non-aqueous electrolytic solution containing an electrolyte and a non-aqueous solvent for dissolving the electrolyte is expressed as X—SO ₂ —Y—SO ₂ —Z. and one or more compounds selected from the group consisting of a cyclic compound having an SO ₃ structure and a fluorosulfonate having a specific structure, and X—SO ₂ — in the nonaqueous electrolytic solution. The content of a compound selected from the group consisting of a compound represented by Y—SO ₂ —Z and a cyclic compound having an SO ₃ structure is within a specific range, and the content of a specific fluorosulfonate relative to the content is The inventors have found that the input/output characteristics can be greatly improved when the content mass ratio is set to 1 or less, and have completed the present invention.

More specifically, the present inventor has developed a novel non-aqueous electrolytic solution that greatly improves input/output characteristics and durability compared to conventional solutions. Focusing on the film formation mechanism and elementary reaction rate, various investigations were carried out on the effects of various compounds and their combinations.

The electrode reaction rate, which is related to the input/output characteristics of non-aqueous electrolyte batteries, depends on factors such as the oxidation/reduction stability of the compound itself, the concentration and viscosity (diffusion coefficient) of the compound on the electrode surface, and the stability of the product after the reaction. determined by various factors. The techniques described in Patent Documents 1 and 2 control the charge transfer reaction on the electrode surface by directly introducing (FSO ₂ ) ₂ NLi into the electrolytic solution. The specific compounds described in Patent Documents 3 to 5 are not electrolyte salts, but are decomposed by electrochemical reduction or the like in the battery to produce sulfonates, sulfates, and the like. These compounds have the effect of promoting the supply of lithium ions to the battery surface, but are insufficient in terms of deactivation of reaction active sites on the electrode surface, for example. There was a drawback. The present inventors have found that a specific fluorosulfonate has the property of increasing the lithium ion concentration on the surface of the positive electrode/negative electrode and deactivating the active sites on the surface of the positive electrode/negative electrode to efficiently protect the surface of the positive electrode/negative electrode. By introducing together with a compound selected from the group consisting of a compound represented by X—SO ₂ —Y—SO ₂ —Z and a cyclic compound having an SO ₃ structure, and controlling the contents of both, lithium ions can be supplied. The inventors have found that the effect of improving input/output characteristics and durability can be maximized by balancing the properties and electrode reactivity, and have completed the present invention.

That is, the present invention provides specific embodiments and the like shown in [1] to [9] below.
[1] Formula (1) below:
X—SO ₂ —Y—SO ₂ —Z (1)
[In the formula (1), Y is an organic group containing either a nitrogen atom or a carbon atom, and in the case of a nitrogen atom, it is an imide structure lithium salt that becomes N-Li, and in the case of a carbon atom, -O- It is an alkylene diester structure of (CH ₂ ) _n —O—. X and Z are a fluorine atom or a hydrocarbon group having 1 to 12 carbon atoms which may contain a fluorine atom. X and Z may be the same or different, and may combine with each other to form a ring structure. When forming a ring structure, either X or Z may be omitted. n is an integer of 1 or more and 2 or less. ]
one or more compounds selected from the group (A) consisting of a compound represented by and a cyclic compound having an _SO3 structure;
Formula (2) below:
( _FSO3 ) _x M (2)
[In formula (2), M is a metal atom, and x is the valence of the metal atom M and is an integer of 1 or more]
A non-aqueous electrolytic solution containing a fluorosulfonate (B) represented by
The ratio of the content of the fluorosulfonate (B) to the content of the compound belonging to the group (A) in the non-aqueous electrolyte is 1 or less, and the group (A) in the non-aqueous electrolyte is A non-aqueous electrolytic solution containing 0.01% by mass or more and 8% by mass or less of the belonging compound.
[2] The non-aqueous electrolytic solution according to [1], wherein the content of the fluorosulfonate (B) in the non-aqueous electrolytic solution is 2% by mass or less.
[3] The non-aqueous electrolytic solution according to [1] or [2], wherein the fluorosulfonate (B) contains FSO ₃ Li.
[4] [1] to [3], wherein the compound represented by formula (1) is (FSO ₂ ) ₂ NLi, (CF ₃ SO ₂ ) ₂ NLi or (C ₂ F ₅ SO ₂ ) ₂ NLi ] The non-aqueous electrolytic solution according to any one of
[5] The cyclic compound having the SO ₃ structure is 1,3-propanesultone, 1,3-propenesultone or 1,2-ethylene sulfate, according to any one of [1] to [4]. Non-aqueous electrolyte.
[6] The nonaqueous electrolytic solution according to any one of [1] to [5], wherein the nonaqueous electrolytic solution contains LiPF ₆ .
[7] An energy device comprising a plurality of electrodes capable of absorbing and releasing metal ions, and the non-aqueous electrolytic solution according to any one of [1] to [6].
[8] The energy device according to [7], wherein the plurality of electrodes capable of intercalating and deintercalating metal ions are a positive electrode and a negative electrode, and the negative electrode contains a carbonaceous material or a silicon-containing material.
[9] The energy device according to [7] or [8], wherein the plurality of electrodes capable of intercalating and deintercalating metal ions are a positive electrode and a negative electrode, and the positive electrode contains a transition metal oxide.

According to the present invention, the initial input/output characteristics are significantly improved, and the input/output retention rate and capacity retention rate during cycle operation and high temperature storage, battery swelling, and metal elution are good. Non-aqueous electrolyte secondary battery. It is possible to provide a non-aqueous electrolytic solution that can realize energy devices such as Further, according to a preferred embodiment of the present invention, a non-aqueous electrolyte capable of realizing an energy device that is excellent not only in input/output characteristics but also in impedance characteristics, charge/discharge rate characteristics, etc., as well as in continuous charging characteristics, safety, etc. liquid can be provided. Also, an energy device using this non-aqueous electrolytic solution can be provided.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. The following embodiments are examples (representative examples) of embodiments of the present invention, and the present invention is not limited to these. In addition, the present invention can be arbitrarily changed and implemented without departing from the gist thereof.

<1. Compound Essential for the Non-Aqueous Electrolyte Solution of the Present Invention>
The non-aqueous electrolytic solution of the present invention has the following formula (1):
X—SO ₂ —Y—SO ₂ —Z (1)
[In the formula (1), Y is an organic group containing either a nitrogen atom or a carbon atom, and in the case of a nitrogen atom, it is an imide structure lithium salt that becomes N-Li, and in the case of a carbon atom, -O- It is an alkylene diester structure of (CH ₂ ) _n —O—. X and Z are a fluorine atom or a hydrocarbon group having 1 to 12 carbon atoms which may contain a fluorine atom. X and Z may be the same or different, and may combine with each other to form a ring structure. When forming a ring structure, either X or Z may be omitted. n is an integer of 1 or more and 2 or less. ]
and one or more compounds selected from the group (A) consisting of a cyclic compound having an _SO3 structure, and the following formula (2):
( _FSO3 ) _x M (2)
[In formula (2), M is a metal atom, and x is the valence of the metal atom M and is an integer of 1 or more]
Contains a fluorosulfonate (B) represented by

<1-1. A compound selected from the group (A) consisting of a compound represented by X—SO ₂ —Y—SO ₂ —Z and a cyclic compound having an SO ₃ structure>
<1-1-1. Compound Represented by X—SO ₂ —Y—SO ₂ —Z>
In formula (1), Y is an organic group containing either a nitrogen atom or a carbon atom. In the case of a nitrogen atom, it is an imide structure lithium salt that becomes N—Li, and in the case of a carbon atom, —O—( CH ₂ ) _n —O— alkylene diester structure. X and Z are a fluorine atom or a hydrocarbon group having 1 to 12 carbon atoms which may contain a fluorine atom. X and Z may be the same or different, and may combine with each other to form a ring structure. When forming a ring structure, either X or Z may be omitted. n is an integer of 1 or more and 2 or less.

When Y is a nitrogen atom, it is a lithium salt with an imide structure, and X and Z are a hydrocarbon group containing a fluorine atom having 1 to 4 carbon atoms or a fluorine atom. It is preferable from the viewpoint of being able to improve the electrical conductivity of.

Preferred imide structure lithium salts include (FSO ₂ ) ₂ NLi, (FSO ₂ )(CF ₃ SO ₂ )NLi, (CF ₃ SO ₂ ) ₂ NLi, (C ₂ F ₅ SO ₂ ) ₂ NLi, lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropanedisulfonylimide, (CF ₃ SO ₂ )(C ₄ F ₉ SO ₂ )NLi and the like.

Among these, (FSO ₂ ) ₂ NLi, (CF ₃ SO ₂ ) ₂ NLi, and (C ₂ F ₅ SO ₂ ) ₂ NLi are more preferable from the viewpoint of not reducing the viscosity of the electrolytic solution, and (FSO ₂ ) ₂ NLi
is more preferable from the viewpoint of the effect of improving input/output characteristics and durability.

Further, when Y is a carbon atom, it is a compound having an alkylene diester structure, and X and Z are preferably hydrocarbon groups having 1 to 6 carbon atoms from the viewpoint of not lowering the viscosity of the electrolytic solution.

Preferred compounds having an alkylene disulfonic acid ester structure include:
Cyclic disulfonic acid ester compounds such as methylene methane disulfonate, ethylene methane disulfonate, methylene ethane disulfonate, and ethylene ethane disulfonate;
chain disulfonic acid ester compounds such as methylenebis(methanesulfonate), methylenebis(ethanesulfonate), methylenebis(benzenesulfonate), ethylenebis(methanesulfonate), ethylenebis(ethanesulfonate), ethylenebis(benzenesulfonate);
etc.

Among these, methylene methane disulfonate, ethylene methane disulfonate, and methylene bis(methanesulfonate) are preferable from the viewpoint of improving input/output characteristics, and methylene methane disulfonate is more preferable from the viewpoint of improving the input/output characteristics and durability.

The content of the compound represented by X—SO ₂ —Y—SO ₂ —Z in the non-aqueous electrolytic solution of the present invention is 0.01% by mass or more, preferably 0.1% by mass or more, more preferably It is 0.3% by mass or more and 8% by mass or less, preferably 7% by mass or less, and more preferably 6% by mass or less. Within the above range, not only input/output characteristics but also durability such as cycle capacity and storage capacity can be further improved, battery swelling and metal elution can be further reduced, and safety can be improved.

<1-1-2. Cyclic compounds with SO ₃ groups>
In the non-aqueous electrolytic solution of the present invention, the cyclic compound having an SO ₃ group that can be used is not particularly limited as long as it is a cyclic compound having an SO ₃ group in the molecule. A compound having a cyclic sulfate (hereinafter sometimes abbreviated as a cyclic sulfonate compound or a cyclic sulfate compound) is preferable, and a compound represented by the following general formula (3) is more preferable. The method for producing the cyclic compound having an SO ₃ group is not particularly limited, and any known method can be selected for production.

In general formula (3), each of R ⁷ and R ⁸ is an organic organic compound composed of atoms selected from the group consisting of carbon, hydrogen, nitrogen, oxygen, sulfur, phosphorus and halogen atoms. represents a group, and R ⁷ and R ⁸ may each contain an unsaturated bond together with --SO ₃ --.
Here, R ⁷ and R ⁸ are preferably an organic group composed of atoms consisting of a carbon atom, a hydrogen atom, an oxygen atom and a sulfur atom, especially a hydrocarbon group having 1 to 3 carbon atoms, - An organic group having SO ₃ — is preferred.

The molecular weight of the cyclic compound having an SO ₃ group is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. The molecular weight of the cyclic compound having an SO ₃ group is usually 100 or more, preferably 110 or more, and usually 250 or less, preferably 220 or less. Within this range, it is easy to ensure the solubility of the cyclic compound having ₃ SO 2 groups in the non-aqueous electrolytic solution, and the effects of the present invention are easy to manifest.

Specific examples of the compound represented by the general formula (3) include, for example,
1,3-propanesultone, 1-fluoro-1,3-propanesultone, 2-fluoro-1,3-propanesultone, 3-fluoro-1,3-propanesultone, 1-methyl-1,3-propanesultone , 2-methyl-1,3-propanesultone, 3-methyl-1,3-propanesultone, 1-propene-1,3-sultone, 2-propene-1,3-sultone, 1-fluoro-1-propene -1,3-sultone, 2-fluoro-1-propene-1,3-sultone, 3-fluoro-1-propene-1,3-sultone, 1-fluoro-2-propene-1,3-sultone, 2 -fluoro-2-propene-1,3-sultone, 3-fluoro-2-propene-1,3-sultone, 1-methyl-1-propene-1,3-sultone, 2-methyl-1-propene-1 , 3-sultone, 3-methyl-1-propene-1,3-sultone, 1-methyl-2-propene-1,3-sultone, 2-methyl-2-propene-1,3-sultone, 3-methyl -2-propene-1,3-sultone, 1,4-butanesultone, 1-fluoro-1,4-butanesultone, 2-fluoro-1,4-butanesultone, 3-fluoro-1,4-butanesultone, 4-fluoro -1,4-butanesultone, 1-methyl-1,4-butanesultone, 2-methyl-1,4-butanesultone, 3-methyl-1,4-butanesultone, 4-methyl-1,4-butanesultone, 1-butene -1,4-sultone, 2-butene-1,4-sultone, 3-butene-1,4-sultone, 1-fluoro-1-butene-1,4-sultone, 2-fluoro-1-butene-1 ,4-sultone, 3-fluoro-1-butene-1,4-sultone, 4-fluoro-1-butene-1,4-sultone, 1-fluoro-2-butene-1,4-sultone, 2-fluoro -2-butene-1,4-sultone, 3-fluoro-2-butene-1,4-sultone, 4-fluoro-2-butene-1,4-sultone, 1-fluoro-3-butene-1,4 -sultone, 2-fluoro-3-butene-1,4-sultone, 3-fluoro-3-butene-1,4-sultone, 4-fluoro-3-butene-1,4-sultone, 1-methyl-1 -butene-1,4-sultone, 2-methyl-1-butene-1,4-sultone, 3-methyl-1-butene-1,4-sultone, 4-methyl-1-butene-1,4-sultone , 1-methyl-2-butene-1,4-sultone, 2-methyl-2-butene-1,4-sultone, 3-methyl-2-butene-1,4-sultone, 4-methyl-2-butene -1,4-sultone, 1-methyl-3-butene-1,4-sultone, 2-methyl-3-butene-1,4-sultone, 3-methyl-3-butene-1,4-sultone, 4 -methyl-3-butene-1,4-sultone, 1,5-pentanesultone, 1-fluoro-1,5-pentanesultone, 2-fluoro-1,5-pentanesultone, 3-fluoro-1,5- Pentanesultone, 4-fluoro-1,5-pentanesultone, 5-fluoro-1,5-pentanesultone, 1-methyl-1,5-pentanesultone, 2-methyl-1,5-pentanesultone, 3-methyl -1,5-pentanesultone, 4-methyl-1,5-pentanesultone, 5-methyl-1,5-pentanesultone, 1-pentene-1,5-sultone, 2-pentene-1,5-sultone, 3-pentene-1,5-sultone, 4-pentene-1,5-sultone, 1-fluoro-1-pentene-1,5-sultone, 2-fluoro-1-pentene-1,5-sultone, 3- fluoro-1-pentene-1,5-sultone, 4-fluoro-1-pentene-1,5-sultone, 5-fluoro-1-pentene-1,5-sultone, 1-fluoro-2-pentene-1, 5-sultone, 2-fluoro-2-pentene-1,5-sultone, 3-fluoro-2-pentene-1,5-sultone, 4-fluoro-2-pentene-1,5-sultone, 5-fluoro- 2-pentene-1,5-sultone, 1-fluoro-3-pentene-1,5-sultone, 2-fluoro-3-pentene-1,5-sultone, 3-fluoro-3-pentene-1,5- sultone, 4-fluoro-3-pentene-1,5-sultone, 5-fluoro-3-pentene-1,5-sultone, 1-fluoro-4-pentene-1,5-sultone, 2-fluoro-4- Pentene-1,5-sultone, 3-fluoro-4-pentene-1,5-sultone, 4-fluoro-4-pentene-1,5-sultone, 5-fluoro-4-pentene-1,5-sultone, 1-methyl-1-pentene-1,5-sultone, 2-methyl-1-pentene-1,5-sultone, 3-methyl-1-pentene-1,5-sultone, 4-methyl-1-pentene- 1,5-sultone, 5-methyl-1-pentene-1,5-sultone, 1-methyl-2-pentene-1,5-sultone, 2-methyl-2-pentene-1,5-sultone, 3- methyl-2-pentene-1,5-sultone, 4-methyl-2-pentene-1,5-sultone, 5-methyl-2-pentene-1,5-sultone, 1-methyl-3-pentene-1, 5-sultone, 2-methyl-3-pentene-1,5-sultone, 3-methyl-3-pentene-1,5-sultone, 4-methyl-3-pentene-1,5-sultone, 5-methyl- 3-pentene-1,5-sultone, 1-methyl-4-pentene-1,5-sultone, 2-methyl-4-pentene-1,5-sultone, 3-methyl-4-pentene-1,5- sultone, 4-methyl-4-pentene-1,5-sultone, 5-methyl-4-pentene-1,5-sultone, 1,2-oxathiolane-2,2-dioxid-4-yl-acetate, 1, 2-oxathiolane-2,2-dioxido-4-yl-propionate, 5-methyl-1,2-oxathiolane-2,2-dioxido-4-one-2,2-dioxide, 5,5-dimethyl-1, sultone compounds such as 2-oxathiolane-2,2-dioxid-4-one-2,2-dioxide;

1,2,3-oxathiazolidine-2,2-dioxide, 3-methyl-1,2,3-oxathiazolidine-2,2-dioxide, 3H-1,2,3-oxathiazol-2,2-dioxide , 5H-1,2,3-oxathiazolidine-2,2-dioxide, 1,2,4-oxathiazolidine-2,2-dioxide, 4-methyl-1,2,4-oxathiazolidine-2,2- Dioxide, 3H-1,2,4-oxathiazole-2,2-dioxide, 5H-1,2,4-oxathiazole-2,2-dioxide, 1,2,5-oxathiazolidine-2,2-dioxide , 5-methyl-1,2,5-oxathiazolidine-2,2-dioxide, 3H-1,2,5-oxathiazole-2,2-dioxide, 5H-1,2,5-oxathiazole-2, 2-dioxide, 1,2,3-oxathiazinane-2,2-dioxide, 3-methyl-1,2,3-oxathiazinane-2,2-dioxide, 5,6-dihydro-1,2,3-oxathiazine- 2,2-dioxide, 1,2,4-oxathiazinane-2,2-dioxide, 4-methyl-1,2,4-oxathiazinane-2,2-dioxide, 5,6-dihydro-1,2,4- oxathiazine-2,2-dioxide, 3,6-dihydro-1,2,4-oxathiazine-2,2-dioxide, 3,4-dihydro-1,2,4-oxathiazine-2,2-dioxide, 1, 2,5-oxathiazinane-2,2-dioxide, 5-methyl-1,2,5-oxathiazinane-2,2-dioxide, 5,6-dihydro-1,2,5-oxathiazine-2,2-dioxide, 3,6-dihydro-1,2,5-oxathiazine-2,2-dioxide, 3,4-dihydro-1,2,5-oxathiazine-2,2-dioxide, 1,2,6-oxathiazinane-2, 2-dioxide, 6-methyl-1,2,6-oxathiazinane-2,2-dioxide, 5,6-dihydro-1,2,6-oxathiazine-2,2-dioxide, 3,4-dihydro-1, Nitrogen-containing compounds such as 2,6-oxathiazine-2,2-dioxide and 5,6-dihydro-1,2,6-oxathiazine-2,2-dioxide;
1,2,3-oxathiaphoslane-2,2-dioxide, 3-methyl-1,2,3-oxathiaphoslane-2,2-dioxide, 3-methyl-1,2,3-oxathi Afoslan-2,2,3-trioxide, 3-methoxy-1,2,3-oxathiaphoslane-2,2,3-trioxide, 1,2,4-oxathiaphoslane-2,2-dioxide , 4-methyl-1,2,4-oxathiaphoslane-2,2-dioxide, 4-methyl-1,2,4-oxathiaphoslane-2,2,4-trioxide, 4-methoxy-1 , 2,4-oxathiaphoslane-2,2,4-trioxide, 1,2,5-oxathiaphoslane-2,2-dioxide, 5-methyl-1,2,5-oxathiaphoslane- 2,2-dioxide, 5-methyl-1,2,5-oxathiaphoshrane-2,2,5-trioxide, 5-methoxy-1,2,5-oxathiaphoshrane-2,2,5- trioxide, 1,2,3-oxathiaphosphinane-2,2-dioxide, 3-methyl-1,2,3-oxathiaphosphinane-2,2-dioxide, 3-methyl-1,2,3- Oxathiaphosphinane-2,2,3-trioxide, 3-Methoxy-1,2,3-oxathiaphosphinane-2,2,3-trioxide, 1,2,4-oxathiaphosphinane-2,2 -dioxide, 4-methyl-1,2,4-oxathiaphosphinane-2,2-dioxide, 4-methyl-1,2,4-oxathiaphosphinane-2,2,3-trioxide, 4-methyl -1,5,2,4-dioxathiaphosphinane-2,4-dioxide, 4-methoxy-1,5,2,4-dioxathiaphosphinane-2,4-dioxide, 3-methoxy-1 , 2,4-oxathiaphosphinane-2,2,3-trioxide, 1,2,5-oxathiaphosphinane-2,2-dioxide, 5-methyl-1,2,5-oxathiaphosphinane- 2,2-dioxide, 5-methyl-1,2,5-oxathiaphosphinane-2,2,3-trioxide, 5-methoxy-1,2,5-oxathiaphosphinane-2,2,3- trioxide, 1,2,6-oxathiaphosphinane-2,2-dioxide, 6-methyl-1,2,6-oxathiaphosphinane-2,2-dioxide, 6-methyl-1,2,6- phosphorus-containing compounds such as oxathiaphosphinane-2,2,3-trioxide, 6-methoxy-1,2,6-oxathiaphosphinane-2,2,3-trioxide;
1,2-ethylene sulfate, 1,2-propylene sulfate, 1,3-propylene sulfate, 1,2-butylene sulfate, 1,3-butylene sulfate, 1,4-butylene sulfate, 1, Alkylene sulfate compounds such as 2-pentylene sulfate, 1,3-pentylene sulfate, 1,4-pentylene sulfate and 1,5-pentylene sulfate, vinylene sulfate;
etc.

Among these, 1,3-propanesultone, 1-fluoro-1,3-propanesultone, 2-fluoro-1,3-propanesultone, 3-fluoro-1,3-propanesultone, 1-propene-1, 3-sultone, 1-fluoro-1-propene-1,3-sultone, 2-fluoro-1-propene-1,3-sultone, 3-fluoro-1-propene-1,3-sultone, 1,4- Butane sultone, methylene methane disulfonate, ethylene methane disulfonate, 1,2-ethylene sulfate, 1,2-propylene sulfate or 1,3-propylene sulfate is preferable from the viewpoint of improving storage characteristics, and 1,3-propane sultone. , 1-fluoro-1,3-propanesultone, 2-fluoro-1,3-propanesultone, 3-fluoro-1,3-propanesultone, 1-propene-1,3-sultone, methylene methanedisulfonate, ethylene Methane disulfonate, 1,2-ethylene sulfate or 1,3-propylene sulfate are more preferred.

A cyclic compound having an SO ₃ group may be used singly, or two or more of them may be used in any combination and ratio. The content of the cyclic compound having ₃ SO groups with respect to the entire non-aqueous electrolytic solution of the present invention is 0.01% by mass or more, more preferably 0.1% by mass or more, and further It is preferably 0.3% by mass or more, and 8% by mass or less, preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less. When the above range is satisfied, it is preferable from the viewpoint of improving cycle characteristics, high-temperature storage characteristics, etc., and reducing swelling of the battery.

The non-aqueous electrolytic solution of the present invention may contain a plurality of types of compounds belonging to group (A). In that case, the content of the entire compound belonging to group (A) is 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.1% by mass or more, relative to the non-aqueous electrolytic solution of the present invention. It is 3% by mass or more and 8% by mass or less, preferably 7% by mass or less, and more preferably 6% by mass or less.
The method for producing the compound selected from the group consisting of the compound represented by X—SO ₂ —Y—SO ₂ —Z and the cyclic compound having the SO ₃ structure is not particularly limited, and can be produced by combining known methods. .

<1-2. ( _FSO3 ) _xM >
The non-aqueous electrolytic solution of the present invention contains a fluorosulfonate (B) represented by the formula (2): (FSO ₃ ) _x M . In formula (2), M is a metal atom, and x is the valence of the metal atom M and is an integer of 1 or more. The fluorosulfonate (B) may be used alone or in combination of two or more.

In formula (2), x is the valence of the metal atom and is an integer of 1 or more, specifically 1, 2 or 3. Examples of the metal atom include alkali metals such as lithium, sodium, potassium and cesium, alkaline earth metals such as magnesium and calcium, and transition metals such as iron and copper. Lithium is particularly preferred.

Preferred fluorosulfonates (B) include FSO ₃ Li, FSO ₃ Na, FSO ₃ K, FSO ₃ Cs, (FSO ₃ ) ₂ Mg, (FSO ₃ ) ₂ Ca, (FSO ₃ ) ₂ Fe, (FSO ₃ ) ₂ Cu, (FSO ₃ ) ₃ Al and the like. Among them, FSO ₃ Li, FSO ₃ Na, and FSO ₃ K are particularly preferred, and FSO ₃ Li is most preferred from the viewpoint of improving the lithium ion concentration in the battery.
The method of synthesizing and obtaining the fluorosulfonate (B) is not particularly limited, and any method synthesized or obtained can be used. Methods for synthesizing the metal salt of fluorosulfonic acid (B) include, for example, a method of reacting a metal fluoride or a silicon metal fluoride with _SO3 to obtain a metal salt of fluorosulfonic acid; a method of obtaining a metal salt of fluorosulfonic acid by ion exchange; a method of obtaining a metal salt of fluorosulfonic acid by reacting an ammonium salt of fluorosulfonic acid with a metal; Examples include a method of obtaining a metal salt of fluorosulfonic acid by reacting and ion-exchanging, a method of obtaining a metal salt of fluorosulfonic acid by reacting fluorosulfonic acid with a metal halide, and the like.

The non-aqueous electrolytic solution of the present invention may contain at least one fluorosulfonate (B), and may be used alone or in combination of two or more. When two or more are used, one of them is preferably FSO ₃ Li. In particular, a combination of FSO ₃ Li and one or more selected from FSO ₃ Na and FSO ₃ K is preferred.
Specifically, combinations of FSO ₃ Li and FSO ₃ Na, and FSO ₃ Li and FSO ₃ K are preferable in terms of increasing the lithium concentration in the non-aqueous electrolytic solution.

The content of the fluorosulfonate (B) in the non-aqueous electrolytic solution of the present invention is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention, but is usually 0.001% by mass or more, preferably is 0.01% by mass, more preferably 0.1% by mass, and usually 2% by mass, preferably 1.7% by mass, and more preferably 1.5% by mass. By setting this concentration, the amount of interaction with the surfaces of the positive and negative electrodes can be optimized, and the input/output characteristics can be maximized.

<1-3. Content of the essential compound in the non-aqueous electrolytic solution of the present invention>
The ratio of the content mass of the fluorosulfonate (B) to the content mass of the compound belonging to the group (A) in the non-aqueous electrolytic solution of the present invention [(content mass of fluorosulfonate (B))/ (Mass content of compound belonging to group (A))] is 1 or less. Also, it is usually 0.0005 or more, preferably 0.001 or more, more preferably 0.002 or more, and preferably 0.8 or less, more preferably 0.7 or less. By setting this ratio, it is possible to optimize the balance between the amount of interaction with the surfaces of the positive and negative electrodes and the amount of lithium ions supplied, thereby maximizing the input/output characteristics. The above ratio can be applied to any state of the non-aqueous electrolytic solution, and the non-aqueous electrolytic solution before being introduced into the energy device or the non-aqueous electrolytic solution extracted from the energy device may be used. .

Here, the non-aqueous electrolytic solution containing the compound belonging to group (A) and the fluorosulfonate (B) may be prepared by a known method, and is not particularly limited. For example, a method of separately adding a compound belonging to group (A) and fluorosulfonate (B) to a non-aqueous electrolytic solution, or a method of adding a compound belonging to group (A) and / or fluorosulfonate (B) in a solvent A method of mixing with each component to form a non-aqueous electrolytic solution after adding to the group (A), and mixing a compound belonging to group (A) or a fluorosulfonate (B) into a battery component such as an active material or an electrode plate described later. to build a battery element (battery element), inject a non-aqueous electrolyte, and when assembling an energy device such as a non-aqueous electrolyte secondary battery, a compound belonging to group (A) or a fluorosulfonate A method of dissolving (B) in a non-aqueous electrolytic solution, a compound belonging to the group (A) or a compound capable of generating a fluorosulfonate (B) in a non-aqueous electrolytic solution or an energy device in advance in a non-aqueous electrolytic solution or Examples include a method of obtaining an electrolytic solution containing a compound belonging to group (A) or a fluorosulfonate (B) by mixing in an energy device.

<2. Non-aqueous electrolytic solution>
<2-1. Other electrolyte salts>
The non-aqueous electrolytic solution in the present invention may contain one or more electrolyte salts other than the compound belonging to the group (A) and the fluorosulfonate (B). A lithium salt is preferred as the electrolyte salt. There is no particular limitation as long as it is known to be used as an electrolyte salt, and any one can be used. Specific examples include the following.

for example,
Inorganic lithium salts such as _LiBF4 , _LiClO4 , _LiAlF4 , _LiPF6 , _LiSbF6 , _LiTaF6 , _LiWF7 ;
Lithium fluorophosphates other than _LiPF6 , such _{as LiPO3F} , _LiPO2F2 ;
lithium tungstate salts such as LiWOF ₅ ;
_{HCO2Li , CH3CO2Li , CH2FCO2Li , CHF2CO2Li , CF3CO2Li , CF3CH2CO2Li , CF3CF2CO2Li , CF3CF2CF2 _ _ _ carboxylic} acid lithium salts _{such as CO2Li} , _{CF3CF2CF2CF2CO2Li ;
CH3SO3Li , CH2FSO3Li , CHF2SO3Li , CF3SO3Li , CF3CF2SO3Li , CF3CF2CF2SO3Li , CF3CF2CF2CF2 _ _ _ _ _ _} Lithium sulfonate salts such as SO ₃ Li;
Lithium methide salts such _as ( _FSO2 ) _3CLi , ( _CF3SO2 ) _3CLi , ( _{C2F5SO2 ) 3CLi ;}
lithium oxalate salts such as lithium difluorooxalatoborate, lithium bis(oxalato)borate, lithium tetrafluorooxalatophosphate, lithium difluorobis(oxalato)phosphate, lithium tris(oxalato)phosphate;
In addition, _LiPF4 ( _CF3 ) ₂ , _LiPF4 ( _C2F5 ) ₂ , _{LiPF4 ( CF3SO2 ) 2} , _{LiPF4 ( C2F5SO2 ) 2 , LiBF3CF3} , _{LiBF3C 2F5 , LiBF3C3F7} , _LiBF2 ( _{CF3 ) 2} , _LiBF2 ( _C2F5 ) _{2 , LiBF2} ( _{CF3SO2 ) 2 , LiBF2 ( C2F5SO2 ) 2} fluorine-containing organic lithium salts such as;
Among these, from the point of further enhancing the effect of improving initial input/output characteristics, input/output characteristics after endurance tests such as cycle tests and high temperature storage tests, charge/discharge rate charge/discharge characteristics, and impedance characteristics, inorganic lithium salts, fluorophosphorus Those selected from lithium acid salts, lithium sulfonate salts, and lithium oxalate salts are preferred.
Among them, _{LiPF6 , LiBF4} , LiSbF6, _{LiTaF6 , LiPO3F} , _LiPO2F2 , _CF3SO3Li , ( _FSO2 ) _3CLi , _{( CF3SO2 ) 3CLi} , _{( C2F5} SO ₂ )CLi ₃ , lithium difluorooxalatoborate, lithium bis(oxalato)borate, lithium tetrafluorooxalatophosphate, lithium difluorobis(oxalato)phosphate and lithium tris(oxalato)phosphate have improved input/output characteristics and high rate. It is particularly preferable because it has the effect of improving charge/discharge characteristics, impedance characteristics, high-temperature storage characteristics, cycle characteristics, and the like.

The total concentration of the compound belonging to group (A), fluorosulfonate (B) and other electrolyte salts in the non-aqueous electrolyte is not particularly limited, but is usually 8% by mass or more, preferably 8.5% by mass. % or more, more preferably 9 mass % or more. Moreover, the upper limit is usually 18% by mass or less, preferably 17% by mass or less, and more preferably 16% by mass or less. When the total concentration of the compound belonging to group (A), the fluorosulfonate (B) and other electrolyte salts in the non-aqueous electrolyte is within the above range, the electrical conductivity and viscosity are appropriate for battery operation. preferred for

Other electrolyte salts may be used alone or in combination of two or more. Preferred examples of the combined use of two or more are LiPF ₆ and LiBF ₄ , LiPF ₆ and LiPO ₂ F ₂ , LiPF ₆ and lithium bis(oxalato)borate, LiPF ₆ and lithium tetrafluorooxalatophosphate, LiPF ₆ and Lithium difluorobis(oxalato)phosphate, _LiPF6 and _LiBF4 and _{LiPO2F2 , LiPF6} and _{LiPO2F2 and} lithium bis(oxalato)borate, or _{LiPF6 and LiPO2F2} and lithium difluorobis(oxalato) It is used in combination with phosphate, and has the effect of improving input/output characteristics, high-temperature storage characteristics, and cycle characteristics. In this case, the content of LiPF ₆ in the non-aqueous electrolyte is preferably 4% by mass or more, more preferably 5% by mass or more, still more preferably 6% by mass or more, preferably 14% by mass or less, and more preferably 13% by mass. % by mass or less, more preferably 12% by mass or less, and the content of LiBF ₄ , LiPO ₂ F ₂ , lithium bis(oxalato)borate, or lithium difluorobis(oxalato)phosphate in the non-aqueous electrolytic solution is Preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, preferably 5% by mass or less, more preferably 4% by mass or less, still more preferably 3% by mass It is below. When the concentration of LiPF ₆ is within the above preferable range, the total ion content and viscosity in the non-aqueous electrolyte are in a suitable balance, so that the internal impedance of the energy device is lowered without excessively lowering the ionic conductivity. , the effect of improving input/output characteristics, cycle characteristics, and storage characteristics due to the addition of LiPF ₆ is more likely to be exhibited.

Particularly preferred combinations for the electrolyte are LiPF ₆ and LiPO ₂ F ₂ , LiPF ₆ and lithium bis(oxalato)borate, and LiPF ₆ and LiPO ₂ F ₂ and lithium bis(oxalato)borate. By combining these with the compound belonging to group (A) and the fluorosulfonate (B), the effects of the present invention, namely, input/output characteristics, cycle capacity, durability such as storage capacity, battery swelling and metal elution It will be possible to maximize the effect of reducing the amount and improving safety.

These electrolyte materials can be produced by conventionally known techniques. Here, preparation of the non-aqueous electrolytic solution containing the electrolyte material may be performed by a known method, and is not particularly limited. For example, a method of adding the separately synthesized electrolyte material to a non-aqueous electrolytic solution, or a method of mixing the electrolyte material into a battery component such as an active material or an electrode plate to be described later to construct a battery element (battery element). a method of dissolving the electrolyte material in the non-aqueous electrolyte when assembling the battery by injecting the non-aqueous electrolyte, allowing water to coexist in the battery components such as the active material, the electrode plate, and the separator, A method of generating other electrolyte materials in the system when a non-aqueous electrolyte secondary battery is assembled using the non-aqueous electrolyte solution containing the above-mentioned electrolyte material is included. Either method may be used in the present invention.

The method for measuring the non-aqueous electrolyte and the content of each electrolyte in the non-aqueous electrolyte secondary battery is not particularly limited, and any known method can be used. Specific examples include ion chromatography and nuclear magnetic resonance spectroscopy (NMR).

<2-2. Non-aqueous solvent>
The non-aqueous electrolytic solution according to one embodiment of the present invention normally contains, as its main component, a non-aqueous solvent that dissolves the above-described electrolyte, as with general non-aqueous electrolytic solutions. The non-aqueous solvent used here is not particularly limited, and known organic solvents can be used. Examples of the organic solvent include, but are not limited to, saturated cyclic carbonates, chain carbonates, chain carboxylic acid esters, cyclic carboxylic acid esters, ether compounds, sulfone compounds, and the like. These can be used individually by 1 type or in combination of 2 or more types.
In one embodiment of the present invention, the non-aqueous electrolytic solution preferably contains one or more selected from the group consisting of cyclic carbonates, chain carbonates and chain esters.

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

The content of the saturated cyclic carbonate is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. It is 3% by volume or more, preferably 5% by volume or more. By setting this range, it is possible to avoid a decrease in electrical conductivity due to a decrease in the dielectric constant of the non-aqueous electrolyte, and to improve the large current discharge characteristics of the non-aqueous electrolyte secondary battery, the stability to the negative electrode, and the cycle characteristics. range. The upper limit is usually 90% by volume or less, preferably 85% by volume or less, more preferably 80% by volume or less. By setting the viscosity of the non-aqueous electrolyte in this range, the viscosity of the non-aqueous electrolyte is set to an appropriate range, the decrease in ionic conductivity is suppressed, and the input/output characteristics of the non-aqueous electrolyte secondary battery are further improved. Durability such as characteristics can be further improved, which is preferable.

Also, two or more saturated cyclic carbonates can be used in any combination. One preferred combination is a combination of ethylene carbonate and propylene carbonate. In this case, the volume ratio of ethylene carbonate to propylene carbonate is preferably 99:1 to 40:60, more preferably 95:5 to 50:50. Furthermore, the lower limit of the amount of propylene carbonate in the total non-aqueous solvent is usually 1% by volume or more, preferably 2% by volume or more, and more preferably 3% by volume or more. Moreover, the upper limit is usually 30% by volume or less, preferably 25% by volume or less, and more preferably 20% by volume or less. When the propylene carbonate content is within this range, the low temperature properties are further improved, which is preferable.

<2-2-2. Chain carbonate>
As the chain carbonate, those having 3 to 7 carbon atoms are preferred.
Specifically, chain carbonates having 3 to 7 carbon atoms include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate, methyl-n-propyl carbonate, n-butyl methyl carbonate, isobutyl methyl carbonate, t-butyl methyl carbonate, ethyl-n-propyl carbonate, n-butyl ethyl carbonate, isobutyl ethyl carbonate, t-butyl ethyl carbonate and the like.
Among them, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate and methyl-n-propyl carbonate are preferred, and dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate are particularly preferred. be.

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

Fluorinated dimethyl carbonate derivatives include fluoromethylmethyl carbonate, difluoromethylmethyl carbonate, trifluoromethylmethyl carbonate, bis(fluoromethyl) carbonate, bis(difluoro)methyl carbonate, bis(trifluoromethyl) carbonate and the like.
Fluorinated ethyl methyl carbonate derivatives include 2-fluoroethyl methyl carbonate, ethyl fluoromethyl carbonate, 2,2-difluoroethyl methyl carbonate, 2-fluoroethyl fluoromethyl carbonate, ethyl difluoromethyl carbonate, 2,2,2-tri fluoroethyl methyl carbonate, 2,2-difluoroethyl fluoromethyl carbonate, 2-fluoroethyl difluoromethyl carbonate, ethyltrifluoromethyl carbonate and the like.
Fluorinated diethyl carbonate derivatives include ethyl-(2-fluoroethyl) carbonate, ethyl-(2,2-difluoroethyl) carbonate, bis(2-fluoroethyl) carbonate, ethyl-(2,2,2-trifluoro ethyl) carbonate, 2,2-difluoroethyl-2′-fluoroethyl carbonate, bis(2,2-difluoroethyl) carbonate, 2,2,2-trifluoroethyl-2′-fluoroethyl carbonate, 2,2, 2-trifluoroethyl-2',2'-difluoroethyl carbonate, bis(2,2,2-trifluoroethyl) carbonate and the like.

A chain carbonate may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
Although the content of the chain carbonate is not particularly limited, it is usually 15% by volume or more, preferably 20% by volume or more, more preferably 25% by volume or more in 100% by volume of the non-aqueous solvent. Also, it is usually 90% by volume or less, preferably 85% by volume or less, more preferably 80% by volume or less. By setting the content of the chain carbonate in the above range, the viscosity of the non-aqueous electrolyte solution is set in an appropriate range, the decrease in ionic conductivity is suppressed, and the input/output characteristics and charge/discharge characteristics of the non-aqueous electrolyte secondary battery are improved. It becomes easier to keep the rate characteristics in a good range. In addition, it becomes easy to avoid a decrease in electrical conductivity due to a decrease in the dielectric constant of the non-aqueous electrolyte, and to make the input/output characteristics and charge/discharge rate characteristics of the non-aqueous electrolyte secondary battery within favorable ranges.

Furthermore, by combining a specific linear carbonate with a specific content of ethylene carbonate, the battery performance can be remarkably improved.
For example, when dimethyl carbonate and ethyl methyl carbonate are selected as specific chain carbonates, the content of ethylene carbonate is not particularly limited and is arbitrary as long as it does not significantly impair the effects of the present invention, but is usually 15% by volume or more. , preferably 20% by volume, usually 45% by volume or less, preferably 40% by volume or less, and the content of dimethyl carbonate is usually 20% by volume or more, preferably 30% by volume or more, and usually 50% by volume or less, It is preferably 45% by volume or less, and the content of ethyl methyl carbonate is usually 20% by volume or more, preferably 30% by volume or more, and usually 50% by volume or less, preferably 45% by volume or less. By setting the content within the above range, the viscosity of the non-aqueous electrolytic solution is lowered while the low-temperature deposition temperature of the electrolyte is lowered, the ionic conductivity is improved, and high input/output can be obtained even at low temperatures.

<2-2-3. Chain carboxylic acid ester>
Chain carboxylic acid esters include those having a total carbon number of 3 to 7 in the structural formula.
Specifically, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, Isopropyl propionate, n-butyl propionate, isobutyl propionate, t-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, isobutyrate -n- Examples include propyl and isopropyl isobutyrate.
Among them, methyl acetate, ethyl acetate, -n-propyl acetate, -n-butyl acetate, methyl propionate, ethyl propionate, -n-propyl propionate, isopropyl propionate, methyl butyrate or ethyl butyrate are ionized due to viscosity reduction. It is preferable from the viewpoint of improving conductivity and suppressing battery swelling during endurance such as cycling and storage.

The content of the chain carboxylic acid ester is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. It is usually 80% by volume or less, preferably 70% by volume or less. When the content of the chain carboxylic acid ester is within the above range, the electrical conductivity of the non-aqueous electrolyte is improved, and the input/output characteristics and charge/discharge rate characteristics of the non-aqueous electrolyte secondary battery are easily improved. In addition, an increase in the negative electrode resistance is suppressed, and the input/output characteristics and charge/discharge rate characteristics of the non-aqueous electrolyte secondary battery are easily brought into a favorable range.

When a chain carboxylic acid ester is used, it is preferably used in combination with a cyclic carbonate, more preferably in combination with a cyclic carbonate and a chain carbonate.
For example, when a cyclic carbonate and a chain carboxylic acid ester are used in combination, the content of the cyclic carbonate is not particularly limited and is arbitrary as long as it does not significantly impair the effects of the present invention. % by volume, and usually 45% by volume or less, preferably 40% by volume or less, and the content of the chain carboxylic acid ester is usually 20% by volume or more, preferably 30% by volume or more, and usually 55% by volume or less, preferably is 50% by volume or less. Further, when a cyclic carbonate, a chain carbonate and a chain carboxylic acid ester are used in combination, the content of the cyclic carbonate is not particularly limited and is arbitrary as long as it does not significantly impair the effects of the present invention, but is usually 15% by volume or more. , preferably 20% by volume, usually 45% by volume or less, preferably 40% by volume or less, and the content of the chain carbonate is usually 25% by volume or more, preferably 30% by volume or more, and usually 84% by volume or less. , preferably 80% by volume or less. By setting the content within the above range, the viscosity of the non-aqueous electrolytic solution is lowered while the low-temperature deposition temperature of the electrolyte is lowered, and the ionic conductivity is improved, and even higher input/output can be obtained even at low temperatures. It is also preferable from the viewpoint of further reducing battery swelling.

<2-2-4. Cyclic carboxylic acid ester>
Cyclic carboxylic acid esters include those having 3 to 12 total carbon atoms in the structural formula.
Specific examples include gamma-butyrolactone, gamma-valerolactone, gamma-caprolactone, epsilon-caprolactone and the like. Among them, gamma-butyrolactone is particularly preferable from the viewpoint of improvement in battery characteristics resulting from improvement in the degree of dissociation of lithium ions.

The content of the cyclic carboxylic acid ester is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. , and usually 60% by volume or less, preferably 50% by volume or less. When the content of the cyclic carboxylic acid ester is within the above range, the electrical conductivity of the non-aqueous electrolyte is improved, and the input/output characteristics and charge/discharge rate characteristics of the non-aqueous electrolyte secondary battery are easily improved. In addition, the viscosity of the non-aqueous electrolyte is set to an appropriate range to avoid a decrease in electrical conductivity, suppress an increase in negative electrode resistance, and improve the input/output characteristics and charge/discharge rate characteristics of the non-aqueous electrolyte secondary battery. It becomes easier to

<2-2-5. Ether-based compound>
Preferred ether compounds are chain ethers having 3 to 10 carbon atoms and cyclic ethers having 3 to 6 carbon atoms.
Chain ethers having 3 to 10 carbon atoms include diethyl ether, di(2-fluoroethyl) ether, di(2,2-difluoroethyl) ether, di(2,2,2-trifluoroethyl) ether, ethyl (2-fluoroethyl) ether, ethyl (2,2,2-trifluoroethyl) ether, ethyl (1,1,2,2-tetrafluoroethyl) ether, (2-fluoroethyl) (2,2,2 -trifluoroethyl)ether, (2-fluoroethyl)(1,1,2,2-tetrafluoroethyl)ether, (2,2,2-trifluoroethyl)(1,1,2,2-tetrafluoro ethyl) ether, ethyl-n-propyl ether, ethyl (3-fluoro-n-propyl) ether, ethyl (3,3,3-trifluoro-n-propyl) ether, ethyl (2,2,3,3- tetrafluoro-n-propyl) ether, ethyl (2,2,3,3,3-pentafluoro-n-propyl) ether, 2-fluoroethyl-n-propyl ether, (2-fluoroethyl) (3-fluoro -n-propyl) ether, (2-fluoroethyl)(3,3,3-trifluoro-n-propyl) ether, (2-fluoroethyl)(2,2,3,3-tetrafluoro-n-propyl) ) ether, (2-fluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, 2,2,2-trifluoroethyl-n-propyl ether, (2,2,2 -trifluoroethyl)(3-fluoro-n-propyl)ether, (2,2,2-trifluoroethyl)(3,3,3-trifluoro-n-propyl)ether, (2,2,2- trifluoroethyl)(2,2,3,3-tetrafluoro-n-propyl)ether, (2,2,2-trifluoroethyl)(2,2,3,3,3-pentafluoro-n-propyl) ) ether, 1,1,2,2-tetrafluoroethyl-n-propyl ether, (1,1,2,2-tetrafluoroethyl)(3-fluoro-n-propyl) ether, (1,1,2 ,2-tetrafluoroethyl)(3,3,3-trifluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethyl)(2,2,3,3-tetrafluoro-n- propyl) ether, (1,1,2,2-tetrafluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di-n-propyl ether, (n-propyl) ( 3-fluoro-n-propyl) ether, (n-propyl)(3,3,3-trifluoro-n-propyl) ether, (n-propyl)(2,2,3,3-tetrafluoro-n- propyl) ether, (n-propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di(3-fluoro-n-propyl) ether, (3-fluoro-n-propyl) (3,3,3-trifluoro-n-propyl) ether, (3-fluoro-n-propyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (3-fluoro-n- propyl)(2,2,3,3,3-pentafluoro-n-propyl) ether, di(3,3,3-trifluoro-n-propyl) ether, (3,3,3-trifluoro-n -propyl)(2,2,3,3-tetrafluoro-n-propyl) ether, (3,3,3-trifluoro-n-propyl)(2,2,3
,3,3-pentafluoro-n-propyl) ether, di(2,2,3,3-tetrafluoro-n-propyl) ether, (2,2,3,3-tetrafluoro-n-propyl) ( 2,2,3,3,3-pentafluoro-n-propyl) ether, di(2,2,3,3,3-pentafluoro-n-propyl) ether, di-n-butyl ether, dimethoxymethane, methoxy ethoxymethane, methoxy(2-fluoroethoxy)methane, methoxy(2,2,2-trifluoroethoxy)methane methoxy(1,1,2,2-tetrafluoroethoxy)methane, diethoxymethane, ethoxy(2-fluoro ethoxy)methane, ethoxy(2,2,2-trifluoroethoxy)methane, ethoxy(1,1,2,2-tetrafluoroethoxy)methane, di(2-fluoroethoxy)methane, (2-fluoroethoxy) ( 2,2,2-trifluoroethoxy)methane, (2-fluoroethoxy)(1,1,2,2-tetrafluoroethoxy)methane di(2,2,2-trifluoroethoxy)methane, (2,2, 2-trifluoroethoxy)(1,1,2,2-tetrafluoroethoxy)methane, di(1,1,2,2-tetrafluoroethoxy)methane, dimethoxyethane, methoxyethoxyethane, methoxy(2-fluoroethoxy ) ethane, methoxy(2,2,2-trifluoroethoxy)ethane, methoxy(1,1,2,2-tetrafluoroethoxy)ethane, diethoxyethane, ethoxy(2-fluoroethoxy)ethane, ethoxy(2, 2,2-trifluoroethoxy)ethane, ethoxy(1,1,2,2-tetrafluoroethoxy)ethane, di(2-fluoroethoxy)ethane, (2-fluoroethoxy)(2,2,2-trifluoro ethoxy)ethane, (2-fluoroethoxy)(1,1,2,2-tetrafluoroethoxy)ethane, di(2,2,2-trifluoroethoxy)ethane, (2,2,2-trifluoroethoxy) (1,1,2,2-tetrafluoroethoxy)ethane, di(1,1,2,2-tetrafluoroethoxy)ethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether etc.

Cyclic ethers having 3 to 6 carbon atoms include tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-methyl-1,3-dioxane, 1 , 4-dioxane, etc., and fluorinated compounds thereof.
Among these, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether have high solvating ability to lithium ions and exhibit ion dissociation. It is preferable in terms of improvement. Particularly preferred are dimethoxymethane, diethoxymethane and ethoxymethoxymethane, since they have low viscosity and give high ionic conductivity.

The content of the ether-based compound is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. is 3% by volume or more, and usually 30% by volume or less, preferably 25% by volume or less, more preferably 20% by volume or less. If the content of the ether-based compound is within the above preferable range, it is easy to secure the effect of improving the degree of dissociation of lithium ions of the chain ether and the effect of improving the ionic conductivity derived from the decrease in viscosity. In addition, when the negative electrode active material is a carbonaceous material, the phenomenon of co-insertion of the chain ether together with the lithium ions can be suppressed, so that the input/output characteristics and charge/discharge rate characteristics can be set within appropriate ranges.

<2-2-6. Sulfone compound>
Preferred sulfone compounds are cyclic sulfones having 3 to 6 carbon atoms and chain sulfones having 2 to 6 carbon atoms. The number of sulfonyl groups in one molecule is preferably one or two.
Cyclic sulfones include trimethylene sulfones, tetramethylene sulfones and hexamethylene sulfones which are monosulfone compounds; and trimethylene disulfones, tetramethylene disulfones and hexamethylene disulfones which are disulfone compounds. Among them, tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones, and hexamethylene disulfones are more preferable, and tetramethylene sulfones (sulfolanes) are particularly preferable from the viewpoint of dielectric constant and viscosity.

As sulfolanes, sulfolane and/or sulfolane derivatives (hereinafter sometimes abbreviated as “sulfolane” including sulfolane) are preferable. As the sulfolane derivative, one in which one or more hydrogen atoms bonded to carbon atoms constituting a sulfolane ring is substituted with a fluorine atom or an alkyl group is preferable.
Among others, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,2-difluorosulfolane, 2,3-difluorosulfolane, 2,4-difluorosulfolane, 2,5-difluorosulfolane, 3,4-difluorosulfolane, 2-fluoro-3-methylsulfolane, 2-fluoro-2-methylsulfolane, 3-fluoro-3-methylsulfolane, 3-fluoro-2-methylsulfolane, 4-fluoro-3-methyl Sulfolane, 4-fluoro-2-methylsulfolane, 5-fluoro-3-methylsulfolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane, 3-fluoromethylsulfolane, 2-difluoromethylsulfolane, 3-difluoro methylsulfolane, 2-trifluoromethylsulfolane, 3-trifluoromethylsulfolane, 2-fluoro-3-(trifluoromethyl)sulfolane, 3-fluoro-3-(trifluoromethyl)sulfolane, 4-fluoro-3-( Trifluoromethyl)sulfolane, 5-fluoro-3-(trifluoromethyl)sulfolane and the like are preferable because of their high ionic conductivity and high input/output.

Examples of chain sulfone include dimethylsulfone, ethylmethylsulfone, diethylsulfone, n-propylmethylsulfone, n-propylethylsulfone, di-n-propylsulfone, isopropylmethylsulfone, isopropylethylsulfone, diisopropylsulfone, n- butylmethylsulfone, n-butylethylsulfone, t-butylmethylsulfone, t-butylethylsulfone, monofluoromethylmethylsulfone, difluoromethylmethylsulfone, trifluoromethylmethylsulfone, monofluoroethylmethylsulfone, difluoroethylmethylsulfone, trifluoroethylmethylsulfone, pentafluoroethylmethylsulfone, ethylmonofluoromethylsulfone, ethyldifluoromethylsulfone, ethyltrifluoromethylsulfone, perfluoroethylmethylsulfone, ethyltrifluoroethylsulfone, ethylpentafluoroethylsulfone, di(tri fluoroethyl)sulfone, perfluorodiethylsulfone, fluoromethyl-n-propylsulfone, difluoromethyl-n-propylsulfone, trifluoromethyl-n-propylsulfone, fluoromethylisopropylsulfone, difluoromethylisopropylsulfone, trifluoromethylisopropylsulfone , trifluoroethyl-n-propylsulfone, trifluoroethylisopropylsulfone, pentafluoroethyl-n-propylsulfone, pentafluoroethylisopropylsulfone, trifluoroethyl-n-butylsulfone, trifluoroethyl-t-butylsulfone, penta fluoroethyl-n-butylsulfone, pentafluoroethyl-t-butylsulfone and the like.

Among others, dimethylsulfone, ethylmethylsulfone, diethylsulfone, n-propylmethylsulfone, isopropylmethylsulfone, n-butylmethylsulfone, t-butylmethylsulfone, monofluoromethylmethylsulfone, difluoromethylmethylsulfone, trifluoromethylmethylsulfone , monofluoroethylmethylsulfone, difluoroethylmethylsulfone, trifluoroethylmethylsulfone, pentafluoroethylmethylsulfone, ethylmonofluoromethylsulfone, ethyldifluoromethylsulfone, ethyltrifluoromethylsulfone, ethyltrifluoroethylsulfone, ethylpentafluoro ethylsulfone, trifluoromethyl-n-propylsulfone, trifluoromethylisopropylsulfone, trifluoroethyl-n-butylsulfone, trifluoroethyl-t-butylsulfone, trifluoromethyl-n-butylsulfone or trifluoromethyl-t -Butyl sulfone is preferred because of its high ionic conductivity and high input/output.

The content of the sulfone-based compound is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. Above, more preferably 1% by volume or more, and usually 40% by volume or less, preferably 35% by volume or less, more preferably 30% by volume or less. If the content of the sulfone-based compound is within the above range, the effect of improving durability such as cycle characteristics and storage characteristics can be easily obtained. can be avoided, and the input/output characteristics and charge/discharge rate characteristics of the non-aqueous electrolyte secondary battery can be set within appropriate ranges.

<2-3. Auxiliary>
The non-aqueous electrolytic solution of the present invention may further contain various auxiliary agents detailed below.

<2-3-1. A carbonate having at least one of a carbon-carbon unsaturated bond and a fluorine atom>
The non-aqueous electrolytic solution according to one embodiment of the present invention may further contain at least one of a carbonate having a carbon-carbon unsaturated bond and a carbonate having a fluorine atom.
The carbonate having a carbon-carbon unsaturated bond preferably includes a cyclic carbonate having a carbon-carbon unsaturated bond (hereinafter sometimes abbreviated as "unsaturated cyclic carbonate"), and a carbonate having a fluorine atom. Preferred are cyclic carbonates having a fluorine atom.

The cyclic carbonate having a carbon-carbon unsaturated bond is not particularly limited as long as it is a cyclic carbonate having a carbon-carbon unsaturated bond, and any carbonate having a carbon-carbon unsaturated bond can be used. A cyclic carbonate having a substituent having an aromatic ring is also included in the cyclic carbonate having a carbon-carbon unsaturated bond. The method for producing the unsaturated cyclic carbonate is not particularly limited, and any known method can be selected for production.
Examples of unsaturated cyclic carbonates include vinylene carbonates, ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond, phenyl carbonates, vinyl carbonates, allyl carbonates, and the like.

Vinylene carbonates include vinylene carbonate, methylvinylene carbonate, 4,5-dimethylvinylene carbonate, phenylvinylene carbonate, 4,5-diphenylvinylene carbonate, vinylvinylene carbonate, and allylvinylene carbonate.
Specific examples of ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond include vinylethylene carbonate, 4,5-divinylethylene carbonate, phenylethylene carbonate, 4,5-diphenylethylene carbonate, Examples include ethynylethylene carbonate, 4,5-diethynylethylene carbonate, and the like.
Among them, vinylene carbonates and ethylene carbonate substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond are preferred, and vinylene carbonate, 4,5-diphenylvinylene carbonate, 4,5-dimethylvinylene carbonate, vinyl Ethylene carbonate or ethynyl ethylene carbonate are more preferred because they form stable interfacial protective coatings.

The molecular weight of the unsaturated cyclic carbonate is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. The molecular weight of the unsaturated cyclic carbonate is usually 50 or more, preferably 80 or more, and usually 250 or less, preferably 150 or less. Within this range, it is easy to ensure the solubility of the unsaturated cyclic carbonate in the non-aqueous electrolytic solution, and the effects of the present invention are easily exhibited.
The unsaturated cyclic carbonates may be used singly or in combination of two or more in any desired ratio. Moreover, the content of the unsaturated cyclic carbonate is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. The content of the unsaturated cyclic carbonate is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more in 100% by mass of the non-aqueous electrolytic solution, and further It is preferably 0.2% by mass or more, and usually 10% by mass or less, preferably 8% by mass or less, and more preferably 5% by mass or less. Within the above range, the non-aqueous electrolyte secondary battery tends to exhibit sufficient high-temperature storage characteristics and cycle characteristics improving effect.

The cyclic carbonate having a fluorine atom (hereinafter sometimes abbreviated as "fluorinated cyclic carbonate") is not particularly limited as long as it is a cyclic carbonate having a fluorine atom.
Fluorinated cyclic carbonates include derivatives of cyclic carbonates having an alkylene group of 2 to 6 carbon atoms, such as ethylene carbonate derivatives. Ethylene carbonate derivatives include, for example, ethylene carbonate or fluorinated ethylene carbonate substituted with an alkyl group (eg, an alkyl group having 1 to 4 carbon atoms), especially those having 1 to 8 fluorine atoms. is preferred.

Specifically, monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4-fluoro-4-methylethylene carbonate, 4,5-difluoro-4-methylethylene carbonate, 4- Fluoro-5-methylethylene carbonate, 4,4-difluoro-5-methylethylene carbonate, 4-(fluoromethyl)-ethylene carbonate, 4-(difluoromethyl)-ethylene carbonate, 4-(trifluoromethyl)-ethylene carbonate , 4-(fluoromethyl)-4-fluoroethylene carbonate, 4-(fluoromethyl)-5-fluoroethylene carbonate, 4-fluoro-4,5-dimethylethylene carbonate, 4,5-difluoro-4,5-dimethyl ethylene carbonate, 4,4-difluoro-5,5-dimethylethylene carbonate and the like.
Among them, at least one selected from the group consisting of monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate and 4,5-difluoro-4,5-dimethylethylene carbonate has high ionic conductivity. It is more preferred from the viewpoint of imparting properties and forming an interface protective film.

One of the fluorinated cyclic carbonates may be used alone, or two or more of them may be used in any combination and ratio. The content of the fluorinated cyclic carbonate is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. 01% by mass or more, more preferably 0.1% by mass or more, and usually 8% by mass or less, preferably 6% by mass or less, and more preferably 5% by mass or less. Within this range, the non-aqueous electrolyte secondary battery tends to exhibit sufficient cycle characteristics and high-temperature storage characteristics. Within this range, the non-aqueous electrolyte secondary battery tends to exhibit sufficient cycle characteristics and high-temperature storage characteristics.

The fluorinated cyclic carbonate may be used as an auxiliary agent for the non-aqueous electrolytic solution or as a non-aqueous solvent. The content of the fluorinated cyclic carbonate when used as a non-aqueous solvent is usually 8% by mass or more, preferably 10% by mass or more, more preferably 12% by mass or more in 100% by mass of the non-aqueous electrolyte. It is usually 85% by mass or less, preferably 80% by mass or less, and more preferably 75% by mass or less. Within this range, the non-aqueous electrolyte secondary battery tends to exhibit a sufficient effect of improving cycle characteristics, and it is easy to avoid a decrease in the discharge capacity retention rate.

In the non-aqueous electrolytic solution according to one embodiment of the present invention, the carbonate having at least one of a carbon-carbon unsaturated bond and a fluorine atom is a group consisting of vinylene carbonate, vinylethylene carbonate, ethynylethylene carbonate, and fluoroethylene carbonate. At least one more selected is preferred.

<2-3-2. Fluorinated unsaturated cyclic carbonate>
As the fluorinated cyclic carbonate, a cyclic carbonate having an unsaturated bond and a fluorine atom (hereinafter sometimes abbreviated as "fluorinated unsaturated cyclic carbonate") can be used. The fluorinated unsaturated cyclic carbonate is not particularly limited. Among them, those having one or two fluorine atoms are preferable. The method for producing the fluorinated unsaturated cyclic carbonate is not particularly limited, and any known method can be selected for production.
The fluorinated unsaturated cyclic carbonates include vinylene carbonate derivatives, ethylene carbonate derivatives substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond, and the like.

Vinylene carbonate derivatives include 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, 4,5-difluoroethylene carbonate and the like.
Ethylene carbonate derivatives substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond include 4-fluoro-4-vinylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, 4,4-difluoro-4 -vinylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, 4-fluoro-4-phenyl ethylene carbonate, 4-fluoro-5-phenylethylene carbonate, 4,4-difluoro-5-phenylethylene carbonate, 4,5-difluoro-4-phenylethylene carbonate and the like.

The molecular weight of the fluorinated unsaturated cyclic carbonate is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. The molecular weight of the fluorinated unsaturated cyclic carbonate is usually 50 or more, preferably 80 or more, and usually 250 or less, preferably 150 or less. Within this range, it is easy to ensure the solubility of the fluorinated cyclic carbonate in the non-aqueous electrolytic solution, and the effects of the present invention are likely to be exhibited.

The fluorinated unsaturated cyclic carbonates may be used singly, or two or more of them may be used in any combination and ratio. Also, the amount of the fluorinated unsaturated cyclic carbonate to be blended is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. The content of the fluorinated unsaturated cyclic carbonate is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.2% by mass or more in 100% by mass of the non-aqueous electrolytic solution, and , usually 5% by mass or less, preferably 4% by mass or less, more preferably 3% by mass or less. Within this range, the non-aqueous electrolyte secondary battery tends to exhibit a sufficient effect of improving cycle characteristics.

<2-3-3. Compound Having a Cyano Group>
In the nonaqueous electrolytic solution of the present invention, the compound having a cyano group that can be used is not particularly limited as long as it is a compound having a cyano group in the molecule. Compounds represented are more preferred. The method for producing the compound having a cyano group is not particularly limited, and any known method can be selected for production.

In general formula (4), T represents an organic group composed of atoms selected from the group consisting of a carbon atom, a hydrogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom and a halogen atom, and U represents a substituent. is a V-valent organic group having 1 to 10 carbon atoms which may have V is an integer of 1 or more, and when V is 2 or more, T may be the same or different.
The molecular weight of the compound having a cyano group is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. The molecular weight of the compound having a cyano group is usually 40 or more, preferably 45 or more, more preferably 50 or more, and usually 200 or less, preferably 180 or less, more preferably 170 or less. Within this range, it is easy to ensure the solubility of the compound having a cyano group in the non-aqueous electrolytic solution, and the effects of the present invention are likely to be exhibited.

Specific examples of the compound represented by the general formula (4) include, for example,
acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile 2-methylbutyronitrile, trimethylacetonitrile, hexanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, acrylonitrile, methacrylonitrile, Crotononitrile, 3-methylcrotononitrile, 2-methyl-2-butenenitrile, 2-pentenenitrile, 2-methyl-2-pentenenitrile, 3-methyl-2-pentenenitrile, 2-hexenenitrile, fluoro acetonitrile, difluoroacetonitrile, trifluoroacetonitrile, 2-fluoropropionitrile, 3-fluoropropionitrile, 2,2-difluoropropionitrile, 2,3-difluoropropionitrile, 3,3-difluoropropionitrile, 2,2,3-trifluoropropionitrile, 3,3,3-trifluoropropionitrile, 3,3'-oxydipropionitrile, 3,3'-thiodipropionitrile, 1,2,3-propanetrile compounds having one cyano group such as carbonitrile, 1,3,5-pentanetricarbonitrile, pentafluoropropionitrile;
malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeronitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile, dodecanedinitrile, methylmalononitrile, ethylmalononitrile, isopropylmalononitrile, tert-butylmalononitrile, methylsuccinonitrile , 2,2-dimethylsuccinonitrile, 2,3-dimethylsuccinonitrile, trimethylsuccinonitrile, tetramethylsuccinonitrile, 3,3′-(ethylenedioxy)dipropionitrile, 3,3′-( compounds having two cyano groups such as ethylenedithio)dipropionitrile;
Compounds having three cyano groups such as 1,2,3-tris(2-cyanoethoxy)propane and tris(2-cyanoethyl)amine;
cyanate compounds such as methylcyanate, ethylcyanate, propylcyanate, butylcyanate, pentylcyanate, hexylcyanate, heptylcyanate;
methyl thiocyanate, ethyl thiocyanate, propyl thiocyanate, butyl thiocyanate, pentyl thiocyanate, hexyl thiocyanate, heptyl thiocyanate, methanesulfonyl cyanide, ethanesulfonyl cyanide, propanesulfonyl cyanide, butanesulfonyl cyanide, pentanesulfonyl cyanide, hexanesulfonyl cyanide , heptanesulfonyl cyanidate, methylsulfurocyanidate, ethylsulfurocyanidate, propylsulfurocyanidate, butylsulfurocyanidate, pentylsulfurocyanidate, hexylsulfurocyanidate, heptylsulfurocyanidate sulfur-containing compounds such as furocyanidate;
Cyanodimethylphosphine, cyanodimethylphosphine oxide, methyl cyanomethylphosphinate, methyl cyanomethylphosphite, dimethylphosphinate cyanide, dimethylphosphite cyanide, dimethyl cyanophosphonate, dimethyl cyanophosphonite, cyanomethyl methylphosphonate, methyl phosphonite Phosphorus-containing compounds such as cyanomethyl acid, cyanodimethyl phosphate, and cyanodimethyl phosphite;
etc.

Among these, acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile, crotononitrile, 3-methylcrotononitrile, malononitrile, succinonitrile, glutaronitrile, adiponitrile, Pimeronitrile, suberonitrile, azelanitrile, sebaconitrile, undecandinitrile, or dodecanedinitrile are preferred from the viewpoint of improving storage characteristics, and malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeronitrile, suberonitrile, azelanitrile, and sebaconitrile having two cyano groups. , undecandinitrile, or dodecandinitrile are more preferred.

The compounds having a cyano group may be used singly, or two or more of them may be used in any combination and ratio. The content of the compound having a cyano group in the entire non-aqueous electrolytic solution of the present invention is not limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. 001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, and more It is preferably contained at a concentration of 3% by mass or less. When the above range is satisfied, effects such as input/output characteristics, charge/discharge rate characteristics, cycle characteristics, and high-temperature storage characteristics are further improved.

<2-3-4. Isocyanate compound>
In the non-aqueous electrolytic solution of the present invention, the compound having an isocyanate group that can be used (hereinafter sometimes abbreviated as "isocyanate compound") is a compound having an isocyanate group in the molecule. The type is not particularly limited. As the isocyanate compound, a diisocyanate compound having two isocyanate groups in the molecule is preferable.

<2-3-4-1. Diisocyanate compound>
As the diisocyanate compound that can be used in the non-aqueous electrolytic solution of the present invention, a compound having a nitrogen atom only in the isocyanate group in the molecule and represented by the following general formula (5) is preferable.

In the above general formula (5), X may contain a cyclic structure and is an organic group having from 1 to 15 carbon atoms. The number of carbon atoms in X is usually 2 or more, preferably 3 or more, more preferably 4 or more, and is usually 14 or less, preferably 12 or less, more preferably 10 or less, still more preferably 8 or less.
In the general formula (5), X is particularly preferably an organic group having 4 to 15 carbon atoms and having one or more cycloalkylene groups or aromatic hydrocarbon groups having 4 to 6 carbon atoms. At this time, a hydrogen atom on the cycloalkylene group may be substituted with a methyl group or an ethyl group. Since the diisocyanate compound having the cyclic structure is a molecule because it is sterically bulky, side reactions on the positive electrode are less likely to occur, resulting in improved cycle characteristics and high-temperature storage characteristics. Here, the bonding site of the group that bonds to the cycloalkylene group or the aromatic hydrocarbon group is not particularly limited, and may be any of the meta-position, para-position, and ortho-position.
An appropriate cross-linking distance between films is advantageous for lithium ion conductivity, and is preferable because resistance is easily lowered. In addition, the cycloalkylene group is preferably a cyclopentylene group or a cyclohexylene group from the viewpoint that the diisocyanate compound itself is unlikely to cause a side reaction, and a cyclohexylene group is preferred because of the effect of molecular mobility. It is more preferable because it is easy to reduce.
Moreover, it is preferable to have an alkylene group having 1 to 3 carbon atoms between the cycloalkylene group or the aromatic hydrocarbon group and the isocyanate group. Since having an alkylene group makes the material sterically bulky, side reactions on the positive electrode are less likely to occur. Furthermore, when the alkylene group has 1 to 3 carbon atoms, the ratio of the isocyanate group to the total molecular weight does not change significantly, so that the effect of the present invention can be remarkably exhibited.

The molecular weight of the diisocyanate compound represented by the general formula (5) is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. The molecular weight is usually 80 or more, preferably 115 or more, more preferably 170 or more, and usually 300 or less, preferably 230 or less. Within this range, it is easy to ensure the solubility of the diisocyanate compound in the non-aqueous electrolytic solution, and the effects of the present invention are likely to be exhibited.

Specific examples of diisocyanate compounds include, for example,
1,2-diisocyanatocyclopentane, 1,3-diisocyanatocyclopentane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, 1,2 -bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, dicyclohexylmethane-2,2'-diisocyanate, dicyclohexylmethane-2,4' - cycloalkane ring-containing diisocyanates such as diisocyanate, dicyclohexylmethane-3,3'-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate;
1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene-2,3-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,5-diisocyanate, tolylene-2,6 -diisocyanate, tolylene-3,4-diisocyanate, tolylene-3,5-diisocyanate, 1,2-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)benzene, 1,4-bis(isocyanate) natomethyl)benzene, 2,4-diisocyanatobiphenyl, 2,6-diisocyanatobiphenyl, 2,2'-diisocyanatobiphenyl, 3,3'-diisocyanatobiphenyl, 4,4'-diisocyanato- 2-methylbiphenyl, 4,4'-diisocyanato-3-methylbiphenyl, 4,4'-diisocyanato-3,3'-dimethylbiphenyl, 4,4'-diisocyanatodiphenylmethane, 4,4'-diisocyanato-2 -methyldiphenylmethane, 4,4'-diisocyanato-3-methyldiphenylmethane, 4,4'-diisocyanato-3,3'-dimethyldiphenylmethane, 1,5-diisocyanatonaphthalene, 1,8-diisocyanatonaphthalene, 2 ,3-diisocyanatonaphthalene, 1,5-bis(isocyanatomethyl)naphthalene, 1,8-bis(isocyanatomethyl)naphthalene, 2,3-bis(isocyanatomethyl)naphthalene and other aromatic ring-containing diisocyanates ;
etc.

Among these, 1,2-diisocyanatocyclopentane, 1,3-diisocyanatocyclopentane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane , 1,2-bis(isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 1,2-phenylene diisocyanate, 1,3-phenylene diisocyanate , 1,4-phenylene diisocyanate, 1,2-bis (
isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)benzene, 1,4-bis(isocyanatomethyl)benzene, 2,4-diisocyanatobiphenyl or 2,6-diisocyanatobiphenyl is the negative electrode This is preferable because a denser composite coating is formed thereon, resulting in improved battery durability.
Among these, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1,2-bis(isocyanato methyl)benzene, 1,3-bis(isocyanatomethyl)benzene or 1,4-bis(isocyanatomethyl)benzene forms a film on the negative electrode that is advantageous for lithium ion conductivity due to its molecular symmetry; As a result, battery characteristics are further improved, which is more preferable.
Moreover, the diisocyanate compound mentioned above may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

The content of the diisocyanate compound that can be used in the non-aqueous electrolytic solution of the present invention is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. Usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.3% by mass or more, and usually 5% by mass or less, preferably 4% by mass Below, more preferably 3% by mass or less, still more preferably 2% by mass or less. When the content is within the above range, durability such as cycle and storage can be improved, and the effects of the present invention can be fully exhibited.
The method for producing the diisocyanate compound is not particularly limited, and any known method can be selected for production. Moreover, you may use a commercial item.

<2-3-4-2. Isocyanate compounds other than diisocyanate compounds>
The non-aqueous electrolytic solution of the present invention may contain an isocyanate compound other than the diisocyanate compound. Specific examples of isocyanate compounds other than diisocyanate compounds that can be used in the non-aqueous electrolytic solution of the present invention are described below.
Specific examples of isocyanate compounds include, for example,
Hydrocarbon monoisocyanate compounds such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, butyl isocyanate, t-butyl isocyanate, pentyl isocyanate, hexyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate, and fluorophenyl isocyanate;
Monoisocyanate compounds having carbon-carbon unsaturated bonds such as vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, and propynyl isocyanate;
isocyanate compounds such as (ortho-, meta-, para-)toluenesulfonyl isocyanate, benzenesulfonyl isocyanate, fluorosulfonyl isocyanate, phenoxysulfonyl isocyanate, pentafluorophenoxysulfonyl isocyanate, methoxysulfonyl isocyanate;
etc.

One of the isocyanate compounds described above may be used alone, or two or more of them may be used in any combination and ratio.
There is no restriction on the amount of the isocyanate compound to be added to the entire non-aqueous electrolytic solution of the present invention, and it is arbitrary as long as it does not significantly impair the effects of the present invention. The amount is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less with respect to the non-aqueous electrolytic solution of the present invention. , preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 2% by mass or less, particularly preferably 1% by mass or less, and most preferably 0.5% by mass or less. When the content is within the above range, durability such as cycle and storage can be improved, and the effects of the present invention can be fully exhibited.
The method for producing the isocyanate compound is not particularly limited, and any known method can be selected for production. Moreover, you may use a commercial item.

<2-3-5. Carboxylic anhydride>
As the carboxylic acid anhydride that can be used in the non-aqueous electrolytic solution of the present invention, a compound represented by the following general formula (6) is preferable. The method for producing the carboxylic anhydride is not particularly limited, and any known method can be selected for production.

In general formula (6), R ⁹ and R ¹⁰ each independently represent a hydrocarbon group having 1 or more and 15 or less carbon atoms, which may have a substituent. R ⁹ and R ¹⁰ may combine with each other to form a cyclic structure.
The types of R ⁹ and R ¹⁰ are not particularly limited as long as they are monovalent hydrocarbon groups. For example, it may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a combination of an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be a saturated hydrocarbon group and may contain an unsaturated bond (carbon-carbon double bond or carbon-carbon triple bond). The aliphatic hydrocarbon group may be chain or cyclic, and in the case of chain, it may be linear or branched. Furthermore, it may be a combination of a chain and a ring. R ⁹ and R ¹⁰ may be the same or different.

In addition, when ^R9 and ^R10 are bonded together to form a cyclic structure, the hydrocarbon group formed by bonding ^R9 and ^R10 together is divalent. The type of divalent hydrocarbon group is not particularly limited. That is, it may be an aliphatic group, an aromatic group, or a combination of an aliphatic group and an aromatic group. In the case of an aliphatic group, it may be a saturated group or an unsaturated group. Moreover, it may be a chain group or a cyclic group, and in the case of a chain group, it may be a linear group or a branched group. Furthermore, it may be a combination of a chain group and a cyclic group.
In addition, when the hydrocarbon groups of R ⁹ and R ¹⁰ have a substituent, the type of the substituent is not particularly limited as long as it does not contradict the spirit of the present invention, examples include fluorine atom, chlorine atom, bromine atom , and iodine atoms, preferably fluorine atoms. Alternatively, substituents other than the rogen atom include substituents having functional groups such as an ester group, a cyano group, a carbonyl group, an ether group, etc., preferably a cyano group and a carbonyl group. The hydrocarbon groups of R ⁹ and R ¹⁰ may have only one of these substituents, or may have two or more of them. When having two or more substituents, those substituents may be the same or different from each other.

The number of carbon atoms in each of the hydrocarbon groups of R ⁹ and R ¹⁰ is usually 1 or more, and is usually 15 or less, preferably 12 or less, more preferably 10 or less, still more preferably 9 or less. When R ⁹ and R ¹⁰ are bonded to each other to form a divalent hydrocarbon group, the number of carbon atoms in the divalent hydrocarbon group is usually 1 or more and usually 15 or less, preferably It is 13 or less, more preferably 10 or less, and still more preferably 8 or less. When the hydrocarbon groups of R ⁹ and R ¹⁰ have a substituent containing a carbon atom, it is preferable that the total number of carbon atoms in R ⁹ and R ¹⁰ including the substituent satisfies the above range.

Next, specific examples of the carboxylic acid anhydride represented by the general formula (6) (hereinafter sometimes abbreviated as "acid anhydride") will be described. In the following examples, the term "analog" refers to an acid anhydride obtained by replacing a part of the structure of the exemplified acid anhydride with another structure within the scope of the present invention. For example, dimers, trimers and tetramers consisting of multiple acid anhydrides, or structural isomers such as having the same number of carbon atoms in the substituent but having a branched chain, and the substituent is an acid Examples include those with different sites that bind to anhydrides.

First, specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are the same are given below.
Specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are chain alkyl groups include acetic anhydride, propionic anhydride, butanoic anhydride, 2-methylpropionic anhydride, and 2,2-dimethylpropionic anhydride. 2-methylbutanoic anhydride, 3-methylbutanoic anhydride, 2,2-dimethylbutanoic anhydride, 2,3-dimethylbutanoic anhydride, 3,3-dimethylbutanoic anhydride, 2,2, 3-trimethylbutanoic anhydride, 2,3,3-trimethylbutanoic anhydride, 2,2,3,3-tetramethylbutanoic anhydride, 2-ethylbutanoic anhydride, and analogues thereof mentioned.
Specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are cyclic alkyl groups include cyclopropanecarboxylic anhydride, cyclopentanecarboxylic anhydride, cyclohexanecarboxylic anhydride and the like, and analogs thereof. .

Specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are alkenyl groups include acrylic anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride, 2,3-dimethylacrylic anhydride, 3,3-dimethylacrylic anhydride, 2,3,3-trimethylacrylic anhydride, 2-phenylacrylic anhydride, 3-phenylacrylic anhydride, 2,3-diphenylacrylic anhydride, 3, 3-diphenylacrylic anhydride, 3-butenoic anhydride, 2-methyl-3-butenoic anhydride, 2,2-dimethyl-3-butenoic anhydride, 3-methyl-3-butenoic anhydride, 2-methyl-3-methyl-3-butenoic anhydride, 2,2-dimethyl-3-methyl-3-butenoic anhydride, 3-pentenoic anhydride, 4-pentenoic anhydride, 2-cyclopentenecarboxylic Acid anhydrides, 3-cyclopentenecarboxylic anhydride, 4-cyclopentenecarboxylic anhydride, etc., and analogues thereof.
Specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are alkynyl groups include propynoic anhydride, 3-phenylpropynoic anhydride, 2-butynoic anhydride, 2-pentynoic anhydride, and 3-butynoic anhydride. anhydride, 3-pentynoic anhydride, 4-pentynoic anhydride, etc., and analogues thereof.
Specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are aryl groups include benzoic anhydride, 4-methylbenzoic anhydride, 4-ethylbenzoic anhydride, 4-tert-butylbenzoic anhydride, 2-methylbenzoic anhydride, 2,4,6-trimethylbenzoic anhydride, 1-naphthalenecarboxylic anhydride, 2-naphthalenecarboxylic anhydride and the like, and analogs thereof.

Examples of acid anhydrides in which R ⁹ and R ¹⁰ are substituted with halogen atoms include acid anhydrides mainly substituted with fluorine atoms. Acid anhydrides obtained by substituting a chlorine atom, a bromine atom, or an iodine atom are also included in the exemplary compounds.
Examples of acid anhydrides in which R ⁹ and R ¹⁰ are chain alkyl groups substituted with halogen atoms include fluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, 2-fluoropropionic anhydride, 2,2-difluoropropionic anhydride, 2,3-difluoropropionic anhydride, 2,2,3-trifluoropropionic anhydride, 2,3,3-trifluoropropionic anhydride, 2,2, 3,3-tetrapropionic anhydride, 2,3,3,3-tetrapropionic anhydride, 3-fluoropropionic anhydride, 3,3-difluoropropionic anhydride, 3,3,3-trifluoro Examples include propionic anhydride, perfluoropropionic anhydride, and analogs thereof.
Examples of acid anhydrides in which R ⁹ and R ¹⁰ are cyclic alkyl groups substituted with halogen atoms include 2-fluorocyclopentanecarboxylic anhydride, 3-fluorocyclopentanecarboxylic anhydride, and 4-fluorocyclopentane. Examples of acid anhydrides in which R ⁹ and R ¹⁰ are alkenyl groups substituted with halogen atoms include 2-fluoroacrylic anhydride, 3-fluoro acrylic anhydride, 2,3-difluoroacrylic anhydride, 3,3-difluoroacrylic anhydride, 2,3,3-trifluoroacrylic anhydride, 2-(trifluoromethyl)acrylic anhydride, 3-(trifluoromethyl)acrylic anhydride, 2,3-bis(trifluoromethyl)acrylic anhydride, 2,3,3-tris(trifluoromethyl)acrylic anhydride, 2-(4-fluoro Phenyl)acrylic anhydride, 3-(4-fluorophenyl)acrylic anhydride, 2,3-bis(4-fluorophenyl)acrylic anhydride, 3,3-bis(4-fluorophenyl)acrylic anhydride substance, 2-fluoro-3-butenoic anhydride, 2,2-difluoro-3-butenoic anhydride, 3-fluoro-2-butenoic anhydride, 4-fluoro-3-butenoic anhydride, 3, 4-difluoro-3-butenoic anhydride, 3,3,4-trifluoro-3-butenoic anhydride, and analogues thereof.

Examples of acid anhydrides in which R ⁹ and R ¹⁰ are halogen-substituted alkynyl groups include 3-fluoro-2-propynoic anhydride and 3-(4-fluorophenyl)-2-propynoic anhydride. , 3-(2,3,4,5,6-pentafluorophenyl)-2-propynoic anhydride, 4-fluoro-2-butynoic anhydride, 4,4-difluoro-2-butynoic anhydride, 4,4,4-trifluoro-2-butyric anhydride, and analogues thereof.
Examples of acid anhydrides in which R ⁹ and R ¹⁰ are halogen-substituted aryl groups include 4-fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, 4 -trifluoromethylbenzoic anhydride and the like, and analogues thereof.
Examples of acid anhydrides in which R ⁹ and R ¹⁰ have substituents having functional groups such as ester, nitrile, ketone and ether include methoxyformic anhydride, ethoxyformic anhydride, methyloxalic anhydride, ethyl oxalic anhydride, 2-cyanoacetic anhydride, 2-oxopropionic anhydride, 3-oxobutanoic anhydride, 4-acetylbenzoic anhydride, methoxyacetic anhydride, 4-methoxybenzoic anhydride and the like, and analogues thereof.

Next, specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are different from each other are given below.
Although all combinations of the above-listed examples and analogs thereof are conceivable for R ⁹ and R ¹⁰ , representative examples are given below.
Examples of combinations of chain alkyl groups include acetic acid propionic anhydride, acetic acid butanoic anhydride, butanoic propionic anhydride, acetic acid 2-methylpropionic anhydride,
etc.
Examples of combinations of chain alkyl groups and cyclic alkyl groups include cyclopentanoic acid anhydride, cyclohexanoic acid anhydride, cyclopentanoic acid anhydride, and the like.
Examples of combinations of chain alkyl groups and alkenyl groups include acetic acid acrylic anhydride, acetic acid 3-methyl acrylic acid anhydride, acetic acid 3-butenoic acid anhydride, and acrylic acid propionic acid anhydride.
Examples of combinations of chain alkyl groups and alkynyl groups include acetic acid propynoic anhydride, acetic acid 2-butynoic anhydride, acetic acid 3-butynoic anhydride, acetic acid 3-phenylpropynoic anhydride, and propionic acid propynoic anhydride. things, etc.
Examples of combinations of chain alkyl groups and aryl groups include acetic anhydride, 4-methylbenzoic anhydride, 1-naphthalenecarboxylic anhydride, and benzoic propionic anhydride.
Examples of the combination of a chain alkyl group and a hydrocarbon group having a functional group include fluoroacetic anhydride, trifluoroacetic anhydride, 4-fluorobenzoic anhydride, fluoroacetic anhydride, and alkyl acetate. oxalic anhydride, acetic acid 2-cyanoacetic anhydride, acetic acid 2-oxopropionic anhydride, acetic acid methoxyacetic anhydride, methoxyacetic acid propionic anhydride, and the like.

Examples of combinations of cyclic alkyl groups include cyclopentanoic acid, cyclohexanoic anhydride, and the like.
Examples of combinations of cyclic alkyl groups and alkenyl groups include cyclopentanoic acid anhydride, 3-methylcyclopentanoic acid anhydride, 3-butenoic cyclopentanoic anhydride, cyclohexanoic acid anhydride acrylic acid, and the like. are mentioned.
Examples of combinations of cyclic alkyl groups and alkynyl groups include propynoic cyclopentanoic anhydride, 2-butynoic cyclopentanoic anhydride, and propynoic cyclohexanoic anhydride.
Examples of combinations of cyclic alkyl groups and aryl groups include benzoic cyclopentanoic anhydride, 4-methylbenzoic cyclopentanoic anhydride, and benzoic cyclohexanoic anhydride.
Examples of the combination of a cyclic alkyl group and a hydrocarbon group having a functional group include fluoroacetic acid cyclopentanoic anhydride, cyclopentanoic acid trifluoroacetic anhydride, cyclopentanoic acid 2-cyanoacetic anhydride, cyclopentanoic acid methoxyacetic acid anhydride, cyclohexanoic acid fluoroacetic anhydride, and the like.

Examples of combinations of alkenyl groups include 2-methyl acrylic anhydride, 3-methyl acrylic anhydride, 3-butenoic anhydride acrylic acid, and 3-methyl acrylic anhydride 2-methyl acrylic acid. things, etc.
Examples of combinations of alkenyl and alkynyl groups include acrylic propynoic anhydride, acrylic 2-butynoic anhydride, 2-methyl acrylic propynoic anhydride, and the like.
Examples of combinations of alkenyl groups and aryl groups include acrylic benzoic anhydride, 4-methyl acrylate benzoic anhydride, 2-methyl acrylate benzoic anhydride, and the like.
Examples of the combination of an alkenyl group and a hydrocarbon group having a functional group include fluoroacrylate acetic anhydride, trifluoroacetic anhydride acrylate, 2-cyanoacetic anhydride acrylate, methoxy acetic anhydride acrylate, 2- methylacrylic acid fluoroacetic anhydride, and the like.

Examples of combinations of alkynyl groups include propynoic acid-2-butynoic anhydride, propynoic acid-3-butynoic anhydride, 2-butynoic acid-3-butynoic anhydride, and the like.
Examples of combinations of alkynyl groups and aryl groups include benzoic propynoic anhydride, 4-methylbenzoic propynoic anhydride, benzoic 2-butynoic anhydride, and the like.
Examples of the combination of an alkynyl group and a hydrocarbon group having a functional group include fluoropropynoacetic anhydride, trifluoropropynoacetic anhydride, 2-cyanopropynoacetic anhydride, methoxypropynoacetic anhydride, 2- butyric acid fluoroacetic anhydride, and the like.

Examples of combinations of aryl groups include 4-methylbenzoic acid anhydride, 1-naphthalenecarboxylic acid benzoic anhydride, 4-methylbenzoic acid 1-naphthalenecarboxylic acid anhydride, and the like.
Examples of combinations of an aryl group and a hydrocarbon group having a functional group include benzoic fluoroacetic anhydride, benzoic trifluoroacetic anhydride, benzoic 2-cyanoacetic anhydride, benzoic methoxyacetic anhydride, 4- methylbenzoic acid, fluoroacetic anhydride, and the like.

Examples of combinations of hydrocarbon groups having functional groups include fluoroacetic acid trifluoroacetic anhydride, fluoroacetic acid 2-cyanoacetic anhydride, fluoroacetic acid methoxyacetic anhydride, trifluoroacetic acid 2-cyanoacetic anhydride, and the like. are mentioned.
Of the acid anhydrides forming the above chain structure, preferably
Acetic anhydride, propionic anhydride, 2-methylpropionic anhydride, cyclopentanecarboxylic anhydride, cyclohexanecarboxylic anhydride, acrylic anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride , 2,3-dimethylacrylic anhydride, 3,3-dimethylacrylic anhydride, 3-butenoic anhydride, 2-methyl-3-butenoic anhydride, propynoic anhydride, 2-butynoic anhydride , benzoic anhydride, 2-methylbenzoic anhydride, 4-methylbenzoic anhydride, 4-tert-butylbenzoic anhydride, trifluoroacetic anhydride, 3,3,3-trifluoropropionic anhydride , 2-(trifluoromethyl)acrylic anhydride, 2-(4-fluorophenyl)acrylic anhydride, 4-fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride , methoxyformic anhydride, ethoxyformic anhydride,
and more preferably
acrylic anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride, benzoic anhydride, 2-methylbenzoic anhydride, 4-methylbenzoic anhydride, 4-tert-butyl benzoic anhydride 4-fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, methoxyformic anhydride, ethoxyformic anhydride.
These compounds can form bonds with lithium oxalate salts appropriately to form films with excellent durability, and can improve charge/discharge rate characteristics, input/output characteristics, and impedance characteristics, especially after endurance tests. It is preferable from the viewpoint that it can be done.

Next, specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are bonded to each other to form a cyclic structure are given below.
Specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are bonded together to form a 5-membered ring structure include succinic anhydride, 4-methylsuccinic anhydride, and 4,4-dimethylsuccinic anhydride. 4,5-dimethylsuccinic anhydride, 4,4,5-trimethylsuccinic anhydride, 4,4,5,5-tetramethylsuccinic anhydride, 4-vinylsuccinic anhydride, 4,5- Divinylsuccinic anhydride, 4-phenylsuccinic anhydride, 4,5-diphenylsuccinic anhydride, 4,4-diphenylsuccinic anhydride, citraconic anhydride, maleic anhydride, 4-methylmaleic anhydride , 4,5-dimethylmaleic anhydride, 4-phenylmaleic anhydride, 4,5-diphenylmaleic anhydride, itaconic anhydride, 5-methylitaconic anhydride, 5,5-dimethylitaconic anhydride compounds, phthalic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, and analogues thereof.
Specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are bonded together to form a 6-membered ring structure include cyclohexane-1,2-dicarboxylic anhydride and 4-cyclohexene-1,2-dicarboxylic acid. Anhydrides, glutaric anhydride, etc., and analogues thereof are included.
Specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are bonded together to form other cyclic structures include 5-norbornene-2,3-dicarboxylic anhydride and cyclopentanetetracarboxylic dianhydride. , pyromellitic anhydride, diglycolic anhydride, and analogues thereof.
Specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are bonded together to form a cyclic structure and are substituted with a halogen atom include 4-fluorosuccinic anhydride and 4,4-difluorosuccinic anhydride. , 4,5-difluorosuccinic anhydride, 4,4,5-trifluorosuccinic anhydride, 4,4,5,5-tetrafluorosuccinic anhydride, 4-fluoromaleic anhydride, 4,5 -difluoromaleic anhydride, 5-fluoroitaconic anhydride, 5,5-difluoroitaconic anhydride, and analogs thereof.

Among the above acid anhydrides in which R ⁹ and R ¹⁰ are bonded, preferably
Succinic anhydride, 4-methylsuccinic anhydride, 4-vinylsuccinic anhydride, 4-phenylsuccinic anhydride, citraconic anhydride, maleic anhydride, 4-methylmaleic anhydride, 4-phenylmaleic anhydride , itaconic anhydride, 5-methylitaconic anhydride, glutaric anhydride, phthalic anhydride, cyclohexane-1,2-dicarboxylic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, cyclopentanetetra carboxylic dianhydride, pyromellitic anhydride, 4-fluorosuccinic anhydride, 4-fluoromaleic anhydride, 5-fluoroitaconic anhydride,
and more preferably
Succinic anhydride, 4-methylsuccinic anhydride, 4-vinylsuccinic anhydride, citraconic anhydride, cyclohexane-1,2-dicarboxylic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, cyclopentane tetra They are carboxylic dianhydride, pyromellitic anhydride, and 4-fluorosuccinic anhydride. These compounds are preferable because they appropriately form a bond with a lithium oxalate salt to form a film having excellent durability, thereby improving the capacity retention rate particularly after an endurance test.

The molecular weight of the carboxylic acid anhydride is not limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. . When the molecular weight of the carboxylic anhydride is within the above range, the increase in viscosity of the electrolytic solution can be suppressed, and the film density can be optimized, so that the durability can be appropriately improved.
Also, the method for producing the carboxylic acid anhydride is not particularly limited, and any known method can be selected for production. The carboxylic anhydrides described above may be contained singly in the non-aqueous electrolytic solution of the present invention, or two or more of them may be contained in any combination and ratio.
Further, the content of the carboxylic anhydride in the non-aqueous electrolytic solution of the present invention is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. It is desirable to contain it at a concentration of 0.01% by mass or more, preferably 0.1% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less. When the content of the carboxylic acid anhydride is within the above range, the effect of improving the cycle characteristics is likely to be exhibited, and the reactivity is suitable, so the battery characteristics are likely to be improved.

<2-3-6. Overcharge prevention agent>
In the non-aqueous electrolyte solution of the present invention, an overcharge inhibitor can be used in order to effectively suppress battery explosion and ignition when the non-aqueous electrolyte secondary battery is in a state such as overcharge. .
Overcharge inhibitors include biphenyl, alkylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran, diphenylcyclohexane, 1,1,3-trimethyl -aromatic compounds such as 3-phenylindane; partially fluorinated products of the above aromatic compounds such as 2-fluorobiphenyl, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene; 2,4-difluoroanisole, 2,5-difluoro fluorine-containing anisole compounds such as anisole, 2,6-difluoroanisole, and 3,5-difluoroanisole; 3-propylphenyl acetate, 2-ethylphenyl acetate, benzylphenyl acetate, methylphenyl acetate, benzyl acetate, phenethylphenyl acetate, etc. and aromatic carbonates such as diphenyl carbonate and methylphenyl carbonate. Among them, biphenyl, alkylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran, diphenylcyclohexane, 1,1,3-trimethyl-3-phenylindane , 3-propylphenylacetate, 2-ethylphenylacetate, benzylphenylacetate, methylphenylacetate, benzylacetate, phenethylphenylacetate, diphenylcarbonate and methylphenylcarbonate are preferred. These may be used individually by 1 type, or may use 2 or more types together. When two or more of them are used in combination, particularly a combination of cyclohexylbenzene and t-butylbenzene or t-amylbenzene, biphenyl, alkylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene, The combined use of at least one selected from oxygen-free aromatic compounds such as t-amylbenzene and at least one selected from oxygen-containing aromatic compounds such as diphenyl ether and dibenzofuran improves overcharge prevention characteristics and high-temperature storage. This is preferable from the point of balance of properties.
The content of the overcharge inhibitor is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. The content of the overcharge inhibitor is usually 0.1% by mass or more, preferably 0.2% by mass or more, more preferably 0.3% by mass or more, and still more preferably 0.1% by mass or more in 100% by mass of the non-aqueous electrolytic solution. It is 5% by mass or more, and usually 5% by mass or less, preferably 4.8% by mass or less, more preferably 4.5% by mass or less. Within this range, the effect of the overcharge inhibitor can be sufficiently exhibited, and battery characteristics such as high-temperature storage characteristics are improved.

<2-3-7. Other Auxiliaries>
Other known auxiliaries can be used in the non-aqueous electrolytic solution of the present invention. Other auxiliaries include:
Carbonate compounds such as erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl-methyl carbonate;
methyl-2-propynyl oxalate, ethyl-2-propynyl oxalate, bis(2-propynyl) oxalate, 2-propynyl acetate, 2-propynyl formate, 2-propynyl methacrylate, di(2-propynyl) glutarate, methyl-2-propynyl carbonate, ethyl-2-propynyl carbonate, bis(2-propynyl) carbonate, 2-butyne-1,4-diyl-dimethanesulfonate, 2-butyne-1,4-diyl-diethanesulfonate, 2-butyne-1,4-diyl-diformate, 2-butyne-1,4-diyl-diacetate, 2-butyne-1,4-diyl-dipropionate, 4-hexadiyn-1,6-diyl-dimethanesulfonate , 2-propynyl-methanesulfonate, 1-methyl-2-propynyl-methanesulfonate, 1,1-dimethyl-2-propynyl-methanesulfonate, 2-propynyl-ethanesulfonate, 2-propynyl-vinylsulfonate, 2-propynyl- Triple bond-containing compounds such as 2-(diethoxyphosphoryl)acetate, 1-methyl-2-propynyl-2-(diethoxyphosphoryl)acetate, 1,1-dimethyl-2-propynyl-2-(diethoxyphosphoryl)acetate ;
Spiro compounds such as 2,4,8,10-tetraoxaspiro[5.5]undecane and 3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane;
Ethylene sulfite, methyl fluorosulfonate, ethyl fluorosulfonate, methyl methanesulfonate, ethyl methanesulfonate, busulfan, sulfolene, diphenylsulfone, N,N-dimethylmethanesulfonamide, N,N-diethylmethanesulfonamide, methyl Sulfur-containing compounds such as trimethylsilyl sulfate, ethyl trimethylsilyl sulfate, 2-propynyl-trimethylsilyl sulfate;
2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate, 2-isocyanatoethylcrotonate, 2-(2-isocyanatoethoxy)ethyl acrylate, 2-(2-isocyanatoethoxy)ethyl methacrylate, 2-(2 - isocyanate compounds such as isocyanatoethoxy)ethyl crotonate;
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, nonane, decane, cycloheptane;
Fluorinated aromatics such as fluorobenzene, difluorobenzene, hexafluorobenzene, benzotrifluoride, pentafluorophenylmethanesulfonate, pentafluorophenyltrifluoromethanesulfonate, pentafluorophenyl acetate, pentafluorophenyl trifluoroacetate, and methylpentafluorophenyl carbonate Compound;
tris(trimethylsilyl) borate, tris(trimethoxysilyl) borate, tris(trimethylsilyl) phosphate, tris(trimethoxysilyl) phosphate, dimethoxyaluminoxytrimethoxysilane, diethoxyaluminoxytriethoxysilane, dipropoxyalumino oxytriethoxysilane, dibutoxyaluminoxytrimethoxysilane, dibutoxyaluminoxytriethoxysilane, titanium tetrakis (trimethylsiloxide), titanium tetrakis (triethylsiloxide),
silane compounds such as;
2-propynyl 2-(methanesulfonyloxy)propionate, 2-methyl 2-(methanesulfonyloxy)propionate, 2-ethyl 2-(methanesulfonyloxy)propionate, 2-propynyl methanesulfonyloxyacetate, methanesulfonyloxy Ester compounds such as 2-methyl acetate and 2-ethyl methanesulfonyloxyacetate;
Lithium Ethyl Methyloxycarbonyl Phosphonate, Lithium Ethyl Ethyloxycarbonyl Phosphonate, Lithium Ethyl-2-Propynyloxycarbonyl Phosphonate, Lithium Ethyl-1-methyl-2-propynyloxycarbonyl Phosphonate, Lithium Ethyl-1,1-dimethyl-2-propynyl Lithium salts such as oxycarbonylphosphonates;
etc. These may be used individually by 1 type, or may use 2 or more types together. By adding these auxiliaries, it is possible to improve capacity retention characteristics and cycle characteristics after high-temperature storage.
The content of other auxiliaries is not particularly limited, and is arbitrary as long as it does not significantly impair the effects of the present invention. The content of other auxiliaries is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.2% by mass or more in 100% by mass of the non-aqueous electrolytic solution. It is 5% by mass or less, preferably 3% by mass or less, more preferably 1% by mass or less. Within this range, the effect of the other auxiliary agents can be sufficiently exhibited, and battery characteristics such as high-load discharge characteristics can be improved.

The non-aqueous electrolyte described above also includes those existing inside the energy device such as the non-aqueous electrolyte secondary battery according to one embodiment of the present invention. Specifically, the components of the non-aqueous electrolytic solution such as lithium salts, solvents, and auxiliary agents are separately synthesized, and the non-aqueous electrolytic solution is prepared from the substantially isolated ones, and the method described below is used. In the case of a non-aqueous electrolyte in a non-aqueous electrolyte secondary battery obtained by injecting into a separately assembled battery, or the constituent elements of the non-aqueous electrolyte of the present invention are individually placed in the battery, When obtaining the same composition as the non-aqueous electrolyte of the present invention by mixing in a non-aqueous electrolyte secondary battery, furthermore, a compound constituting the non-aqueous electrolyte of the present invention is added to the non-aqueous electrolyte secondary battery. The case where the same composition as the non-aqueous electrolytic solution of the present invention is obtained by generating it inside is also included.

<2-4. Method for producing non-aqueous electrolytic solution>
The non-aqueous electrolytic solution of the present invention comprises the non-aqueous solvent described above, an electrolyte, a compound belonging to the group (A) having a predetermined content ratio, and a fluorosulfonate (B), and optionally the above " It can be prepared by dissolving "auxiliaries" and the like.
When preparing the non-aqueous electrolytic solution, each raw material of the non-aqueous electrolytic solution, that is, an electrolyte such as a lithium salt, a compound belonging to the group (A) and a fluorosulfonate (B), a non-aqueous solvent, an auxiliary agent, etc. , preferably dehydrated in advance. The degree of dehydration is usually 50 ppm or less, preferably 30 ppm or less.
By removing water in the non-aqueous electrolytic solution, electrolysis of water, reaction between water and lithium metal, hydrolysis of lithium salt, and the like are less likely to occur. The dehydration means is not particularly limited. For example, when the object to be dehydrated is a liquid such as a non-aqueous solvent, a desiccant such as a molecular sieve may be used. If the object to be dehydrated is a solid such as an electrolyte, it may be dried by heating at a temperature lower than the temperature at which decomposition occurs.

<3. Energy device using non-aqueous electrolyte>
An energy device using the non-aqueous electrolytic solution of the present invention comprises a plurality of electrodes capable of absorbing or releasing metal ions, and the non-aqueous electrolytic solution of the present invention described above. Specific examples of types of energy devices include primary batteries, secondary batteries, and metal ion capacitors such as lithium ion capacitors. Among them, a primary battery or a secondary battery is preferable, and a secondary battery is particularly preferable. The non-aqueous electrolyte used in these energy devices is also preferably a so-called gel electrolyte that is pseudo-solidified with a polymer, filler, or the like. The energy device will be described below.

<3-1. Non-aqueous electrolyte secondary battery>
<3-1-1. Battery configuration>
A non-aqueous electrolyte secondary battery according to one embodiment of the present invention (hereinafter also referred to as a non-aqueous secondary battery of the present invention) has a configuration other than the non-aqueous electrolyte, which is a conventionally known non-aqueous electrolyte. It is the same as a secondary battery, and usually a positive electrode and a negative electrode are laminated via a porous film (separator) impregnated with the non-aqueous electrolytic solution of the present invention, and these are housed in a case (exterior body). have Therefore, the shape of the non-aqueous electrolyte secondary battery of the present invention is not particularly limited, and may be cylindrical, rectangular, laminated, coin-shaped, large, or the like.

<3-1-2. Non-aqueous electrolytic solution>
As the non-aqueous electrolytic solution, the above non-aqueous electrolytic solution of the present invention is used. It should be noted that other non-aqueous electrolytic solutions may be mixed with the non-aqueous electrolytic solution of the present invention without departing from the gist of the present invention.

<3-1-3. negative electrode>
The negative electrode active material used for the negative electrode is not particularly limited as long as it can electrochemically occlude and release metal ions. Specific examples thereof include carbonaceous materials, metal compound materials, and lithium-containing metal composite oxide materials. One of these may be used alone, or two or more may be used in combination.
Among them, carbonaceous materials and metal compound-based materials are preferable. Among metal compound-based materials, materials containing silicon are preferred, and therefore carbonaceous materials and materials containing silicon are particularly preferred as the negative electrode active material.

<3-1-3-1. Carbonaceous Material>
The carbonaceous material used as the negative electrode active material is not particularly limited, but those selected from the following (a) to (d) provide a secondary battery with a good balance between initial irreversible capacity and high current density charge-discharge characteristics. Therefore, it is preferable.
(a) Natural graphite (b) Artificial carbonaceous material and carbonaceous material obtained by heat-treating the artificial graphite material once or more in the range of 400°C to 3200°C (c) At least two types of negative electrode active material layers Carbonaceous material composed of carbonaceous matter with different crystallinity and/or having an interface where the carbonaceous matter with different crystallinity is in contact (d) Carbonaceous matter in which the negative electrode active material layer has at least two different orientations and/or has an interface where carbonaceous materials with different orientations are in contact with each other. Any combination and ratio may be used together.
Specific examples of the artificial carbonaceous substance or artificial graphite substance in (b) above include natural graphite,
Coal-based coke, petroleum-based coke, coal-based pitch, petroleum-based pitch, and oxidized products of these pitches;
Needle coke, pitch coke, and carbon materials obtained by partially graphitizing them;
Thermal decomposition products of organic matter such as furnace black, acetylene black, pitch-based carbon fiber;
carbonizable organic matter and carbonized products thereof; and
Solution-like carbonized substances obtained by dissolving a carbonizable organic substance in a low-molecular-weight organic solvent such as benzene, toluene, xylene, quinoline, n-hexane, and the like can be mentioned.
In addition, all of the above carbonaceous materials (a) to (d) are conventionally known, their production methods are well known to those skilled in the art, and these commercial products can be purchased.

<3-1-3-2. Metal compound-based material>
The metal compound-based material used as the negative electrode active material is not particularly limited as long as it can absorb and release lithium, and a single metal or alloy that forms an alloy with lithium, or an oxide, carbide, nitride thereof, Compounds such as silicides, sulfides and phosphides can be used. Examples of such metal compounds include compounds containing metals such as Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P, Pb, Sb, Si, Sn, Sr, and Zn. Among them, it is preferably a single metal or alloy that forms an alloy with lithium, and metals and metalloids of Group 13 or 14 of the periodic table (that is, excluding carbon. Hereinafter, metals and metalloids are collectively referred to as " It is more preferable that the material contains silicon (Si), tin (Sn), or lead (Pb) (hereinafter, these three elements are sometimes referred to as “SSP metal elements”). or an alloy containing these atoms, or a compound of those metals (SSP metal element). Compounds containing silicon are particularly preferred. One of these may be used alone, or two or more thereof may be used in any combination and ratio.

<3-1-3-3. Lithium-containing metal composite oxide material>
The lithium-containing metal composite oxide material used as the negative electrode active material is not particularly limited as long as it can occlude and release lithium, but a lithium-containing composite metal oxide material containing titanium is preferable, and a composite oxide of lithium and titanium (hereinafter sometimes abbreviated as "lithium-titanium composite oxide") is particularly preferred. That is, it is particularly preferable to include a lithium-titanium composite oxide having a spinel structure in a negative electrode active material for a lithium-ion non-aqueous electrolyte secondary battery because the output resistance of the secondary battery is greatly reduced.
In addition, at least lithium and titanium in the lithium-titanium composite oxide are selected from the group consisting of other metal elements such as Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and Nb. Those substituted with one element are also preferred.
Lithium-titanium composite oxides preferable as the negative electrode active material include lithium-titanium composite oxides represented by the following general formula (7).
_{LixTiyMzO4 ( 7 )}
(In general formula (7), M represents at least one element selected from the group consisting of Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and Nb. In the general formula (7), 0.7 ≤ x ≤ 1.5, 1.5 ≤ y ≤ 2.3, 0 ≤ z ≤ 1.6 is the structure during doping and undoping of lithium ions. is stable, so it is preferable.)

<3-1-3-4. Composition, physical properties, preparation method of negative electrode>
A known technical configuration can be adopted for the negative electrode containing the active material, the electrode formation method, and the current collector, but any one or more of the following (i) to (vi) should be satisfied at the same time.

(i) Production of Negative Electrode Any known method can be used to produce the negative electrode as long as it does not significantly limit the effects of the present invention. For example, a binder, a solvent, and, if necessary, a thickener, a conductive material, a filler, etc., are added to a negative electrode active material to form a slurry negative electrode forming material, which is applied to a current collector, dried, and then pressed. Thus, a negative electrode active material layer can be formed.

(ii) Current collector Any known current collector can be used as the current collector for holding the negative electrode active material. Examples of the current collector for the negative electrode include metal materials such as aluminum, copper, nickel, stainless steel, and nickel-plated steel. Copper is particularly preferable in terms of ease of processing and cost.
When the current collector is made of a metal material, examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, metal thin film, expanded metal, punched metal, and foamed metal. Among them, metal thin films are preferred, copper foils are more preferred, and rolled copper foils produced by a rolling method and electrolytic copper foils produced by an electrolysis method are even more preferred.

(iii) Thickness Ratio of Current Collector and Negative Electrode Active Material Layer The thickness ratio of the current collector and the negative electrode active material layer is not particularly limited, Negative electrode active material layer thickness)/(current collector thickness)” is preferably 150 or less, more preferably 20 or less, particularly preferably 10 or less, preferably 0.1 or more, and 0.1. 4 or more is more preferable, and 1 or more is particularly preferable.
If the thickness ratio of the current collector and the negative electrode active material layer exceeds the above range, the current collector may generate heat due to Joule heat during high current density charging and discharging of the secondary battery. On the other hand, below the above range, the volume ratio of the current collector to the negative electrode active material increases, and the capacity of the secondary battery may decrease.

(iv) Electrode density The electrode structure when the negative electrode active material is made into an electrode is not particularly limited, and the density of the negative electrode active material present on the current collector is preferably 1 g cm ⁻³ or more, and 1 .2 g·cm ⁻³ or more is more preferable, 1.3 g·cm ⁻³ or more is still more preferable, 4 g·cm ⁻³ or less is preferable, 3 g·cm −3 or less is more preferable, and 2.5 g·cm ⁻³ or more is preferable ^{. 3} or less is more preferable, and 1.7 g·cm ⁻³ or less is particularly preferable. When the density of the negative electrode active material present on the current collector is within the above range, the negative electrode active material particles are less likely to be destroyed, the initial irreversible capacity of the secondary battery increases, and the current collector/negative electrode active material It becomes easy to prevent deterioration of high-current-density charge-discharge characteristics due to a decrease in permeability of the non-aqueous electrolytic solution to the vicinity of the interface. Furthermore, the conductivity between the negative electrode active materials can be ensured, and the capacity per unit volume can be increased without increasing the battery resistance.

(v) Binder, solvent, etc. The slurry for forming the negative electrode active material layer is usually prepared by adding a mixture of a solvent, a binder (binder), a thickener, etc. to the negative electrode active material. be.
The binder that binds the negative electrode active material is not particularly limited as long as it is a material that is stable with respect to the non-aqueous electrolytic solution and the solvent used in electrode production.
Specific examples thereof include resin polymers such as polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, aromatic polyamide, cellulose, and nitrocellulose;
Rubber-like polymers such as SBR (styrene-butadiene rubber), isoprene rubber, butadiene rubber, fluororubber, NBR (acrylonitrile-butadiene rubber), ethylene-propylene rubber;
Styrene/butadiene/styrene block copolymer or a hydrogenated product thereof;
Thermoplastic elastomeric polymers such as EPDM (ethylene-propylene-diene terpolymer), styrene-ethylene-butadiene-styrene copolymer, styrene-isoprene-styrene block copolymer or hydrogenated products thereof;
Soft resinous polymers such as syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene/vinyl acetate copolymer, propylene/α-olefin copolymer;
fluorine-based polymers such as polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene fluoride, and polytetrafluoroethylene/ethylene copolymer;
A polymer composition having ion conductivity of alkali metal ions (especially lithium ions) can be mentioned. These may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and ratios.
As the solvent for forming the slurry, there is no particular limitation on the type of solvent as long as it is capable of dissolving or dispersing the negative electrode active material, the binder, and the thickener and conductive material used as necessary. Either an aqueous solvent or an organic solvent may be used.
Examples of the aqueous solvent include water and alcohol, and examples of the organic solvent include N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, and diethyltriamine. , N,N-dimethylaminopropylamine, tetrahydrofuran (THF), toluene, acetone, diethyl ether, dimethylacetamide, hexamethylphosphalamide, dimethylsulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, hexane, etc. mentioned.
In particular, when using an aqueous solvent, it is preferable to add a dispersant and the like together with the thickener and make a slurry using a latex such as SBR.
In addition, these solvent may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and ratios.

The ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, still more preferably 0.6 parts by mass or more, and preferably 20 parts by mass or less. 15 parts by mass or less is more preferable, 10 parts by mass or less is even more preferable, and 8 parts by mass or less is particularly preferable. When the ratio of the binder to the negative electrode active material is within the above range, the ratio of the binder that does not contribute to the battery capacity does not increase, which makes it difficult to cause a decrease in the battery capacity. Furthermore, it becomes difficult to cause a decrease in the strength of the negative electrode.
In particular, when the slurry, which is the negative electrode forming material, contains a rubber-like polymer represented by SBR as a main component, the ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 0.1 parts by mass or more, and 0.1 part by mass or more. 0.5 mass parts or more is more preferable, 0.6 mass parts or more is still more preferable, 5 mass parts or less is preferable, 3 mass parts or less is more preferable, and 2 mass parts or less is even more preferable.
Further, when the slurry contains a fluorine-based polymer represented by polyvinylidene fluoride as a main component, the ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 1 part by mass or more, and more preferably 2 parts by mass or more. It is preferably 3 parts by mass or more, more preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 8 parts by mass or less.

Thickeners are commonly used to adjust the viscosity of the slurry. The thickener is not particularly limited, but specific examples include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and salts thereof. These may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and ratios.
When a thickener is used, the ratio of the thickener to 100 parts by mass of the negative electrode active material is usually 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 0.6 parts by mass or more. The ratio is usually 5 parts by mass or less, preferably 3 parts by mass or less, more preferably 2 parts by mass or less. When the ratio of the thickener to the negative electrode active material is within the above range, the slurry can be coated well. Furthermore, the proportion of the negative electrode active material in the negative electrode active material layer becomes appropriate, and the problem of a decrease in battery capacity and the problem of an increase in resistance between the negative electrode active materials is less likely to occur.

(vi) Area of Negative Electrode Plate The area of the negative electrode plate is not particularly limited, but it is preferably designed to be slightly larger than the opposing positive electrode plate so that the positive electrode plate does not protrude from the negative electrode plate. In addition, from the viewpoint of suppressing deterioration due to cycle life and high-temperature storage when the secondary battery is repeatedly charged and discharged, it is important to make the area as close to the positive electrode as possible to increase the proportion of the electrode that works more uniformly and effectively and improve the characteristics. It is preferable because it improves. In particular, when the secondary battery is used with a large current, the design of the area of the negative electrode plate is important.

<3-1-4. Positive electrode>
The positive electrode used in the non-aqueous electrolyte secondary battery of the present invention is described below.
<3-1-4-1. Positive electrode active material>
The positive electrode active material used for the positive electrode will be described below.

(1) Composition The positive electrode active material is not particularly limited as long as it is capable of electrochemically intercalating and deintercalating metal ions. Substances containing lithium and at least one transition metal are preferred. Specific examples include lithium-transition metal composite oxides, lithium-containing transition metal phosphate compounds, lithium-containing transition metal silicate compounds, and lithium-containing transition metal borate compounds.
The transition metal of the lithium-transition metal composite oxide is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. Specific examples of the composite oxide include lithium-cobalt composite oxides such as LiCoO ₂ lithium-nickel composite oxides such _as LiNiO2 _; lithium-manganese composite oxides such as _LiMnO2 , _{LiMn2O4 and Li2MnO4} ; Those partially substituted with other metals such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W, etc. is mentioned.
Specific examples of the substituted ones include LiNi _0.5 Mn _0.5 O ₂ , LiNi _0.85 Co _0.10 Al _0.05 O ₂ , LiNi _0.33 Co _0.33 Mn _0.33 O ₂ , LiMn ₂ O ₄ , LiMn _1.8 Al _0.2 O ₄ , Li _1.1 Mn _1.9 Al _0.1 O ₄ , LiMn _1.5 Ni _0.5 O ₄ and the like.
Among them, a composite oxide containing lithium, nickel and cobalt is more preferable. This is because a composite oxide containing cobalt and nickel can have a large capacity when used at the same potential.

Cobalt, on the other hand, is an expensive metal with limited resources, and large batteries that require high capacity, such as those used in automobiles, require a large amount of active material. It is also desirable to use manganese as a main component. That is, a lithium-nickel-cobalt-manganese composite oxide is more preferable. Among them, a lithium-nickel-cobalt-manganese composite oxide in which the amount of cobalt used is reduced and the amount of nickel used is increased is particularly preferable from the viewpoint of achieving a high balance between cost and capacity. For example, LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , LiNi _0.6 Co _0.2 Mn _0.2 O ₂ and LiNi _0.8 Co _0.1 Mn _0.1 O ₂ are particularly preferred. Specific examples include:
In addition, lithium-manganese composite oxides having a spinel structure are also preferable in view of the stability as a compound and the procurement cost due to the ease of production. That is, among the above specific examples, LiMn ₂ O ₄ , LiMn _1.8 Al _0.2 O ₄ , Li _1.1 Mn _1.9 Al _0.1 O ₄ , LiMn _1.5 Ni _0.5 O ₄ etc. can also be cited as a preferred specific example.

The transition metal of the lithium-containing transition metal phosphate compound is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. Specific examples of the phosphate compound include LiFePO ₄ and Li ₃ Fe _{2 .} (PO ₄ ) ₃ , LiFeP ₂ O ₇ and other iron phosphates, LiCoPO ₄ and other cobalt phosphates, LiMnPO ₄ and other manganese phosphates, and some of the transition metal atoms that are the main component of these lithium transition metal phosphate compounds Al, Ti, V, Cr, Mn, Fe, Co,
Those substituted with other metals such as Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W and the like can be mentioned.
The transition metal of the lithium-containing transition metal silicate compound is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. Specific examples of the silicate compound include Li ₂ FeSiO ₄ and the like. iron silicates, cobalt silicates such as Li ₂ CoSiO ₄ , and part of the transition metal atoms that are the main constituents of these lithium transition metal silicate compounds are Al, Ti, V, Cr, Mn, Fe, Co, Those substituted with other metals such as Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W and the like can be mentioned.
The transition metal of the lithium-containing transition metal borate compound is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. Specific examples of the borate compound include boron such as _LiFeBO3 . Iron oxides, cobalt borates such as LiCoBO ₃ , and some of the transition metal atoms that are the main component of these lithium transition metal borate compounds are Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Examples include those substituted with other metals such as Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn and W.

(2) Method for producing positive electrode active material The method for producing the positive electrode active material is not particularly limited as long as it does not exceed the gist of the present invention. method is used.
In particular, various methods are conceivable for producing a spherical or ellipsoidal active material. One example is a transition metal source material such as a transition metal nitrate or sulfate and, if necessary, a source material for another element. Dissolve or pulverize and disperse in a solvent such as water, adjust the pH while stirring to prepare and recover a spherical precursor, and after drying this as necessary, LiOH, Li ₂ CO ₃ , LiNO _{3 .} A method of obtaining an active material by adding a Li source such as the above and sintering at a high temperature can be exemplified.
As an example of another method, transition metal raw materials such as transition metal nitrates, sulfates, hydroxides and oxides and, if necessary, raw materials of other elements are dissolved or pulverized and dispersed in a solvent such as water. Then, it is dried and molded with a spray dryer or the like to obtain a spherical or ellipsoidal precursor, and a Li source such as LiOH, Li ₂ CO ₃ , or LiNO ₃ is added to the precursor and fired at a high temperature to obtain an active material. are mentioned.
As yet another example of a method, transition metal source materials such as transition metal nitrates, sulfates, hydroxides and oxides, Li sources such as LiOH, Li ₂ CO ₃ and LiNO ₃ and optionally other elements is dissolved or pulverized and dispersed in a solvent such as water, dried and molded with a spray dryer or the like to form a spherical or ellipsoidal precursor, which is fired at a high temperature to obtain an active material. mentioned.

<3-1-4-2. Positive electrode structure and manufacturing method>
The configuration of the positive electrode used in the present invention and the manufacturing method thereof will be described below.
(Manufacturing method of positive electrode)
The positive electrode is produced by forming a positive electrode active material layer containing positive electrode active material particles and a binder on a current collector. A positive electrode using a positive electrode active material can be produced by any known method. For example, a positive electrode active material, a binder, and, if necessary, a conductive material, a thickener, etc., are mixed in a dry process to form a sheet, which is crimped to a positive electrode current collector, or these materials are dissolved in a liquid medium. Alternatively, a positive electrode can be obtained by forming a positive electrode active material layer on the current collector by dispersing and forming a slurry, applying the slurry to a positive electrode current collector, and drying the slurry.
The content of the positive electrode active material in the positive electrode active material layer is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and preferably 99.9% by mass or less. There is, and 99 mass % or less is more preferable. When the content of the positive electrode active material is within the above range, sufficient electrical capacity can be ensured. Furthermore, the strength of the positive electrode becomes sufficient. In addition, the positive electrode active material powder in the present invention may be used singly, or two or more kinds having different compositions or different powder physical properties may be used together in an arbitrary combination and ratio. When two or more active materials are used in combination, it is preferable to use the composite oxide containing lithium and manganese as a powder component. As described above, cobalt or nickel is an expensive metal with a small amount of resources, and is not preferable in terms of cost because the amount of active material used in large batteries that require high capacity, such as for automobiles, is large. Therefore, it is desirable to use manganese as a main component as a transition metal that is less expensive.

(Conductive material)
Any known conductive material can be used as the conductive material. Specific examples include metal materials such as copper and nickel; graphite such as natural graphite and artificial graphite; carbon black such as acetylene black; and carbonaceous materials such as amorphous carbon such as needle coke. In addition, these may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
The content of the conductive material in the positive electrode active material layer is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 1% by mass or more, and preferably 50% by mass or less. is more preferably 30% by mass or less, and even more preferably 15% by mass or less. If the content is within the above range, sufficient electrical conductivity can be ensured. Furthermore, it is easy to prevent a decrease in battery capacity.

(binder)
The binder used for manufacturing the positive electrode active material layer is not particularly limited as long as it is a material that is stable with respect to the non-aqueous electrolytic solution and the solvent used for manufacturing the electrode.
When the positive electrode is produced by a coating method, the binder is not particularly limited as long as it is a material that dissolves or disperses in the liquid medium used during electrode production. Specific examples thereof include polyethylene, polypropylene, polyethylene terephthalate, polymethyl Resin polymers such as methacrylate, aromatic polyamide, cellulose, nitrocellulose;
Rubber-like polymers such as SBR (styrene-butadiene rubber), NBR (acrylonitrile-butadiene rubber), fluororubber, isoprene rubber, butadiene rubber, ethylene-propylene rubber;
Styrene/butadiene/styrene block copolymer or hydrogenated product thereof, EPDM (ethylene/propylene/diene terpolymer), styrene/ethylene/butadiene/ethylene copolymer, styrene/isoprene/styrene block copolymer or Thermoplastic elastomeric polymers such as hydrogenates thereof;
Soft resinous polymers such as syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene/vinyl acetate copolymer, propylene/α-olefin copolymer;
Fluorinated polymers such as polyvinylidene fluoride (PVdF), polytetrafluoroethylene, fluorinated polyvinylidene fluoride, and polytetrafluoroethylene/ethylene copolymer;
Examples thereof include polymer compositions having ion conductivity of alkali metal ions (especially lithium ions). In addition, these substances may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

The content of the binder in the positive electrode active material layer is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 3% by mass or more, and preferably 80% by mass or less, 60% by mass or less is more preferable, 40% by mass or less is even more preferable, and 10% by mass or less is particularly preferable. When the ratio of the binder is within the above range, the positive electrode active material can be sufficiently retained and the mechanical strength of the positive electrode can be ensured, resulting in good battery performance such as cycle characteristics. Furthermore, it leads to avoiding deterioration of battery capacity and conductivity.

(liquid medium)
The liquid medium used for preparing the slurry for forming the positive electrode active material layer is a solvent capable of dissolving or dispersing the positive electrode active material, the conductive material, the binder, and the thickening agent used as necessary. If so, the type thereof is not particularly limited, and either an aqueous solvent or an organic solvent may be used.
Examples of the aqueous medium include water, a mixed medium of alcohol and water, and the like. Examples of the organic medium include aliphatic hydrocarbons such as hexane;
aromatic hydrocarbons such as benzene, toluene, xylene, and methylnaphthalene;
Heterocyclic compounds such as quinoline and pyridine;
Ketones such as acetone, methyl ethyl ketone, cyclohexanone;
Esters such as methyl acetate and methyl acrylate;
Amines such as diethylenetriamine and N,N-dimethylaminopropylamine;
Ethers such as diethyl ether and tetrahydrofuran (THF);
Amides such as N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide;
Aprotic polar solvents such as hexamethylphosphaamide and dimethylsulfoxide can be used. In addition, these may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

(thickener)
When an aqueous medium is used as the liquid medium for forming the slurry, it is preferable to use a thickener and a latex such as styrene-butadiene rubber (SBR) to form the slurry. Thickeners are commonly used to adjust the viscosity of slurries.
The thickening agent is not particularly limited as long as it does not significantly limit the effects of the present invention. Specific examples include carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, ethylcellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and salts thereof. etc. These may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and ratios.
When a thickening agent is used, the ratio of the thickening agent to the total weight of the positive electrode active material and the thickening agent is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, It is more preferably 0.6% by mass or more, preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less. Within the above range, the coating properties of the slurry will be good, and the ratio of the active material in the positive electrode active material layer will be sufficient, so the problem of decreasing the capacity of the secondary battery and the gap between the positive electrode active materials This makes it easier to avoid the problem of increased resistance.

(consolidation)
The positive electrode active material layer obtained by applying the slurry to the current collector and drying is preferably densified by hand pressing, roller pressing, or the like in order to increase the packing density of the positive electrode active material. The density of the positive electrode active material layer is preferably 1 g·cm ⁻³ or more, more preferably 1.5 g·cm ⁻³ or more, particularly preferably 2 g·cm ⁻³ or more, and preferably 4 g·cm ⁻³ or less, 3.9 g·cm ⁻³ or less is more preferable, and 3.8 g·cm ⁻³ or less is particularly preferable.
When the density of the positive electrode active material layer is within the above range, the permeability of the non-aqueous electrolytic solution to the vicinity of the current collector/active material interface does not decrease, and charging and discharging at high current densities, especially in secondary batteries, can be performed. Good characteristics. Furthermore, the conductivity between the active materials is less likely to decrease, and the battery resistance is less likely to increase.

(current collector)
The material of the positive electrode current collector is not particularly limited, and any known material can be used. Specific examples include metal materials such as aluminum, stainless steel, nickel plating, titanium and tantalum; and carbonaceous materials such as carbon cloth and carbon paper. Among them, metal materials, particularly aluminum, are preferred.
Examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, metal thin film, expanded metal, punch metal, foam metal, etc. in the case of metal materials, and carbon plate, A carbon thin film, a carbon cylinder, etc. are mentioned. Among these, metal thin films are preferred. Incidentally, the thin film may be appropriately formed in a mesh shape.

Although the thickness of the current collector is arbitrary, it is preferably 1 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more, more preferably 1 mm or less, more preferably 100 μm or less, and further preferably 50 μm or less. preferable. When the thickness of the current collector is within the above range, sufficient strength required for the current collector can be ensured. Furthermore, the handleability is also improved.
The thickness ratio of the current collector and the positive electrode active material layer is not particularly limited, but (thickness of active material layer on one side immediately before non-aqueous electrolyte injection) / (thickness of current collector) is preferably It is 150 or less, more preferably 20 or less, particularly preferably 10 or less, preferably 0.1 or more, more preferably 0.4 or more, and particularly preferably 1 or more. When the thickness ratio between the current collector and the positive electrode active material layer is within the above range, the current collector is less likely to generate heat due to Joule heat during high-current-density charging and discharging of the secondary battery. Furthermore, it becomes difficult to increase the volume ratio of the current collector to the positive electrode active material, and a decrease in battery capacity can be prevented.

(electrode area)
From the viewpoint of high output and high temperature stability, the area of the positive electrode active material layer is preferably larger than the outer surface area of the battery outer case. Specifically, the total electrode area of the positive electrode is preferably 20 times or more, more preferably 40 times or more, with respect to the surface area of the exterior of the non-aqueous electrolyte secondary battery. The outer surface area of the exterior case is the total area calculated from the length, width, and thickness of the case filled with the power generation element, excluding the protrusions of the terminals, in the case of a rectangular shape with a bottom. . In the case of a cylindrical shape with a bottom, it is the geometric surface area that approximates the case portion filled with the power generating element, excluding the projecting portion of the terminal, as a cylinder. The total electrode area of the positive electrode is the geometric surface area of the positive electrode mixture layer facing the mixture layer containing the negative electrode active material. , the sum of the areas calculated separately for each surface.

(discharge capacity)
When using the non-aqueous electrolyte solution of the present invention, the electrical capacity of the battery element housed in one battery exterior of the non-aqueous electrolyte secondary battery (the electrical capacity when the battery is discharged from the fully charged state to the discharged state ) is 1 ampere hour (Ah) or more, the effect of improving low-temperature discharge characteristics is increased, which is preferable. Therefore, the positive electrode plate is designed to have a fully charged discharge capacity of preferably 3 Ah (ampere hour), more preferably 4 Ah or more, preferably 20 Ah or less, and more preferably 10 Ah or less.
Within the above range, the voltage drop due to electrode reaction resistance does not become too large when extracting a large current, and deterioration of power efficiency can be prevented. Furthermore, the temperature distribution due to the heat generated inside the battery during pulse charging and discharging does not become too large, and the durability of repeated charging and discharging is poor. phenomenon can be avoided.

(Thickness of positive electrode plate)
The thickness of the positive electrode plate is not particularly limited, but from the viewpoint of high capacity, high output, and high rate characteristics, the thickness of the positive electrode active material layer after subtracting the thickness of the current collector is is preferably 10 μm or more, more preferably 20 μm or more, and preferably 200 μm or less, more preferably 150 μm or less.

<3-1-5. Separator>
In the non-aqueous electrolyte secondary battery of the present invention, a separator is usually interposed between the positive electrode and the negative electrode in order to prevent short circuits. In this case, the non-aqueous electrolytic solution of the present invention is usually used by impregnating this separator.
There are no particular restrictions on the material and shape of the separator, and known materials can be arbitrarily adopted as long as they do not significantly impair the effects of the present invention. Among them, resins, glass fibers, inorganic substances, etc., which are formed of materials that are stable to the non-aqueous electrolytic solution of the present invention, are used, and porous sheets or non-woven fabrics having excellent liquid retention properties are used. is preferred.
As materials for resin and glass fiber separators, for example, polyolefins such as polyethylene and polypropylene, aramid resin, polytetrafluoroethylene, polyethersulfone, glass filters, and the like can be used. Among them, glass filters and polyolefins are preferred, and polyolefins are more preferred. One of these materials may be used alone, or two or more of them may be used in any combination and ratio.

Although the thickness of the separator is arbitrary, it is preferably 1 µm or more, more preferably 5 µm or more, still more preferably 10 µm or more, and preferably 50 µm or less, more preferably 40 µm or less, and even more preferably 30 µm or less. . When the thickness of the separator is within the above range, good insulating properties and mechanical strength are obtained. Furthermore, deterioration in battery performance such as rate characteristics can be prevented, and reduction in energy density of the non-aqueous electrolyte secondary battery as a whole can also be prevented.
Furthermore, when a porous material such as a porous sheet or non-woven fabric is used as the separator, the porosity of the separator is arbitrary, but is preferably 20% or more, more preferably 35% or more, and further preferably 45% or more. It is preferably 90% or less, more preferably 85% or less, and even more preferably 75% or less. When the porosity is within the above range, the film resistance does not become too large, and deterioration of the rate characteristics of the secondary battery can be suppressed. Furthermore, the mechanical strength of the separator is moderate, and deterioration of insulation can be suppressed.
The average pore size of the separator is also arbitrary, but is preferably 0.5 μm or less, more preferably 0.2 μm or less, and more preferably 0.05 μm or more. When the average pore diameter is within the above range, short circuits are less likely to occur. Furthermore, the membrane resistance does not become too large, and deterioration of the rate characteristics of the secondary battery can be prevented.
On the other hand, as inorganic materials, for example, oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate are used. things are used.
As the form of the separator, a thin film such as a non-woven fabric, a woven fabric, and a microporous film is used. A thin film separator having a pore diameter of 0.01 to 1 μm and a thickness of 5 to 50 μm is preferably used. In addition to the independent thin film shape, a separator can be used in which a composite porous layer containing the inorganic particles is formed on the surface of the positive electrode and/or the negative electrode using a resin binder. For example, alumina particles having a 90% particle size of less than 1 μm are used on both sides of the positive electrode, and a fluororesin is used as a binder to form a porous layer.

<3-1-6. Battery design>
(electrode group)
The electrode group has a laminated structure in which the positive electrode plate and the negative electrode plate are sandwiched between the separators, and a structure in which the positive electrode plate and the negative electrode plate are spirally wound with the separator interposed therebetween. Either is fine. The ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as electrode group occupancy) is preferably 40% or more, more preferably 50% or more, and preferably 95% or less, and 90% The following are more preferred. When the electrode group occupancy is within the above range, it becomes difficult for the battery capacity to decrease. In addition, since an appropriate amount of void space can be secured, when the temperature of the battery becomes high, the internal pressure rises due to the expansion of the members and the increase in the vapor pressure of the liquid component of the non-aqueous electrolyte. It is possible to avoid deterioration of various characteristics such as charge/discharge repetition performance and high temperature storage characteristics, and operation of a gas release valve that releases internal pressure to the outside.

(Current collection structure)
The current collection structure is not particularly limited, but in order to more effectively improve the discharge characteristics of the non-aqueous electrolytic solution of the present invention, a structure that reduces the resistance of the wiring part and the joint part can be used. preferable. When the internal resistance is reduced in this way, the effect of using the non-aqueous electrolytic solution of the present invention is exhibited particularly well.
When the electrode group has the above-described laminated structure, a structure in which the metal core portions of the electrode layers are bundled and welded to a terminal is preferably used. When the area of one electrode increases, the internal resistance increases. Therefore, it is preferable to reduce the resistance by providing a plurality of terminals within the electrode. When the electrode group has the wound structure described above, the internal resistance can be reduced by providing a plurality of lead structures for each of the positive electrode and the negative electrode and bundling them around the terminal.

(protective element)
Protective elements include PTC (Positive Temperature Coefficient) thermistors whose resistance increases when abnormal heat or excessive current flows, thermal fuses, and cuts off the current flowing through the circuit due to a sudden rise in battery internal pressure or internal temperature when abnormal heat is generated. valves (current cut-off valves) and the like. It is preferable to select the protective element under the condition that it does not operate under normal high-current use, and it is more preferable to design a battery that does not lead to abnormal heat generation or thermal runaway even without the protective element.

(Exterior body)
The non-aqueous electrolyte secondary battery of the present invention is generally constructed by housing the non-aqueous electrolyte, the negative electrode, the positive electrode, the separator, and the like in an exterior body (exterior case). There is no restriction on this exterior body, and any known one can be employed as long as it does not significantly impair the effects of the present invention.
The material of the exterior case is not particularly limited as long as it is stable with respect to the non-aqueous electrolytic solution used. Specifically, nickel-plated steel sheets, stainless steel, aluminum or aluminum alloys, magnesium alloys, metals such as nickel and titanium, or laminate films of resin and aluminum foil are used. From the viewpoint of weight reduction, aluminum or aluminum alloy metals and laminated films are preferably used.
The exterior case using the above metals has a sealed structure by welding the metals together by laser welding, resistance welding, or ultrasonic welding, or a crimped structure using the above metals via a resin gasket. There are things to do. Examples of exterior cases using the laminate film include those having a sealing and airtight structure by heat-sealing the resin layers to each other. A resin different from the resin used for the laminate film may be interposed between the resin layers in order to improve the sealing property. In particular, when the resin layer is heat-sealed through the current collector terminal to form a closed structure, the metal and the resin are joined together. A resin is preferably used.
Moreover, the shape of the exterior case is also arbitrary, and may be, for example, cylindrical, square, laminated, coin-shaped, large-sized, or the like.

<3-2. Non-aqueous electrolyte primary battery>
A non-aqueous electrolyte primary battery that is an embodiment of the present invention uses, for example, a material capable of absorbing metal ions for the positive electrode and a material capable of releasing metal ions for the negative electrode. As the positive electrode material, transition metal oxides such as graphite fluoride and manganese dioxide are preferable. As the negative electrode material, simple metals such as zinc and lithium are preferable. The non-aqueous electrolytic solution of the present invention described above is used as the non-aqueous electrolytic solution.

<3-3. Metal ion capacitor>
A metal ion capacitor, which is an embodiment of the present invention, uses, for example, a material capable of forming an electric double layer for the positive electrode and a material capable of intercalating and deintercalating metal ions for the negative electrode. Activated carbon is preferred as the positive electrode material. A carbonaceous material is preferable as the negative electrode material. The non-aqueous electrolytic solution of the present invention described above is used as the non-aqueous electrolytic solution.

<3-4. Electric double layer capacitor>
An electric double layer capacitor which is one embodiment of the present invention uses, for example, a material capable of forming an electric double layer for the electrodes. Activated carbon is preferred as the electrode material. The non-aqueous electrolytic solution of the present invention described above is used as the non-aqueous electrolytic solution.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and reference examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.

(Example 1)
[Preparation of negative electrode]
To 98 parts by mass of the carbonaceous material, as a thickener and binder, 1 part by mass of an aqueous dispersion of sodium carboxymethylcellulose (concentration of 1% by mass of sodium carboxymethylcellulose) and an aqueous dispersion of styrene-butadiene rubber (styrene-butadiene rubber concentration of 50% by mass) was added and mixed with a disperser to form a slurry. The obtained slurry was applied to a copper foil with a thickness of 10 μm, dried, and rolled with a press to obtain an active material layer size of 30 mm wide, 40 mm long, and 5 mm wide, 9 mm long. A negative electrode was obtained by cutting into a shape having a part.

[Preparation of positive electrode]
94% by mass of LiNi _0.6 Mn _0.2 Co _0.2 O ₂ as a positive electrode active material, 3% by mass of acetylene black as a conductive material, and 3% by mass of polyvinylidene fluoride (PVdF) as a binder. were mixed and slurried in the N-methylpyrrolidone solvent. The obtained slurry was applied to one side of a 15 μm thick aluminum foil that had been coated with a conductive agent in advance, dried, and roll-pressed with a press to form an active material layer with a width of 30 mm and a length of 30 mm. A positive electrode was obtained by cutting out a shape having an uncoated portion of 40 mm, 5 mm wide and 9 mm long.

[Preparation of non-aqueous electrolytic solution]
Dry (FSO ₂ ) ₂ NLi (hereinafter lithium bis 4.99% by mass of fluorosulfonylimide), 0.01% by mass of FSO ₃ Li, and 8.8% by mass of LiPF ₆ , and the non-aqueous electrolysis of Example 1 was performed. A liquid was prepared.

[Manufacture of non-aqueous electrolyte secondary battery]
A battery element was produced by stacking the positive electrode, the negative electrode, and the separator made of polyethylene in the order of the negative electrode, the separator, and the positive electrode. After inserting this battery element into a bag made of a laminated film in which both sides of aluminum (thickness 40 μm) are coated with a resin layer so that the positive and negative terminals of the battery element protrude from the bag, the electrolyte solution is added. The sheet-like non-aqueous electrolyte secondary battery of Example 1, which is fully charged at 4.3 V, was produced by injecting it into a bag and vacuum-sealing it.

[Evaluation of initial discharge capacity]
After charging the non-aqueous electrolyte secondary battery to 4.3 V at a constant current equivalent to 0.2 C at 25 ° C. while sandwiching it between glass plates to increase the adhesion between the electrodes, the charge was 0.2 C. was discharged to 2.8 V at a constant current of . This was repeated for two cycles to stabilize the battery. In the third cycle, after charging to 4.3 V at a constant current of 0.2 C, charging was performed at a constant voltage of 4.3 V until the current value reached 0.05 C. , at a constant current of 0.2C to 2.8V. After that, in the fourth cycle, after charging to 4.3V at a constant current of 0.2C, charging was performed at a constant voltage of 4.3V until the current value reached 0.05C, and then charging was performed at a constant current of 0.2C to 2.3V. The battery was discharged to 8 V to obtain the initial discharge capacity.

[Evaluation of output characteristics]
After the evaluation of the initial discharge capacity, the battery was charged at 25° C. with a constant current of 0.2 C to half the initial discharge capacity. This was discharged at 0.5C, 1.0C, 1.5C, 2.0C and 2.5C at 25°C, and the voltage at 10 seconds was measured. A current value at 2.8 V was obtained from a current-voltage straight line, and 2.8×(current value at 2.8 V) was defined as output (W). Table 1 shows the results. In Table 1, the value of the output of Example 1 is shown as a relative output when the output of Comparative Example 1, which will be described later, is set to 100. The same applies hereinafter.

[Evaluation of input characteristics]
After the evaluation of the initial discharge capacity, the battery was charged at 25° C. with a constant current of 0.2 C to half the initial discharge capacity. This was charged at 0.5C, 1.0C, 1.5C, 2.0C and 2.5C at 25°C, and the voltage at 10 seconds was measured. A current value at 4.3 V was obtained from a current-voltage straight line, and 4.3×(current value at 4.3 V) was taken as input (W). Table 1 shows the results. In Table 1, the input values of Example 1 are shown as relative inputs when the input of Comparative Example 1, which will be described later, is set to 100. The same applies hereinafter.

(Example 2)
A sheet-like non-aqueous electrolytic solution of Example 2 was prepared in the same manner as in Example 1, except that 4.9% by mass of lithium bisfluorosulfonylimide and 0.1% by mass of FSO ₃ Li were dissolved. A secondary battery was produced and evaluated. Table 1 shows the results.
[Evaluation of cycle characteristics]
After the evaluation of the initial discharge capacity was completed, the battery was charged at 25° C. at a constant current of 1 C to 4.3 V, and then discharged at a constant current of 0.2 C to 2.8 V. This was taken as one cycle, and 100 cycles were carried out, and (discharge capacity at 100 cycles)/initial discharge capacity×100 was taken as the 25° C. cycle capacity retention rate. Table 1 shows the results. In Table 1, the values of the 25° C. cycle capacity retention rate of Example 2 when the input in the case of Comparative Example 1 described later is set to 100 are listed as relative values. The same applies hereinafter.

(Example 3)
A sheet-like non-aqueous electrolytic solution of Example 3 was prepared in the same manner as in Example 1, except that 4.5% by mass of lithium bisfluorosulfonylimide and 0.5% by mass of FSO ₃ Li were dissolved. A secondary battery was produced and evaluated. Table 1 shows the results.

(Example 4)
A sheet-like non-aqueous electrolytic solution of Example 4 was prepared in the same manner as in Example 1, except that 4.0% by mass of lithium bisfluorosulfonylimide and 1.0% by mass of FSO ₃ Li were dissolved. A secondary battery was produced and evaluated. Table 1 shows the results.

(Example 5)
A sheet-like non-aqueous electrolytic solution of Example 5 was prepared in the same manner as in Example 1, except that 3.0% by mass of lithium bisfluorosulfonylimide and 2.0% by mass of FSO ₃ Li were dissolved. A secondary battery was produced and evaluated. Table 1 shows the results.

(Example 6)
A sheet-like non-aqueous electrolytic solution of Example 6 was prepared in the same manner as in Example 1 except that 6.0% by mass of lithium bisfluorosulfonylimide and 0.5% by mass of FSO ₃ Li were dissolved. A secondary battery was produced and evaluated. Table 1 shows the results.

(Comparative example 1)
A sheet-like non-aqueous electrolyte secondary battery of Comparative Example 1 was prepared in the same manner as in Example 1, except that FSO ₃ Li was not dissolved and lithium bisfluorosulfonylimide was dissolved to 5.0% by mass. was produced and evaluated. Table 1 shows the results.

(Comparative example 2)
A sheet-like non-aqueous electrolytic solution of Comparative Example 2 was prepared in the same manner as in Example 1, except that 2.0% by mass of lithium bisfluorosulfonylimide and 3.0% by mass of FSO ₃ Li were dissolved. A secondary battery was produced and evaluated. Table 1 shows the results.

(Comparative Example 3)
A sheet-like non-aqueous electrolytic solution of Comparative Example 3 was prepared in the same manner as in Example 1, except that 1.0% by mass of lithium bisfluorosulfonylimide and 4.0% by mass of FSO ₃ Li were dissolved. A secondary battery was produced and evaluated. Table 1 shows the results.

(Comparative Example 4)
An attempt was made to mix 4.0% by mass of lithium bisfluorosulfonylimide and 1.0% by mass of lithium methylsulfate and dissolve the mixture in a non-aqueous electrolytic solution, but lithium methylsulfate could not be dissolved. Evaluation was discontinued because a sheet-like non-aqueous electrolyte secondary battery could not be produced.

(Comparative Example 5)
A comparative example was prepared in the same manner as in Example 1, except that 14.4% by mass of lithium bisfluorosulfonylimide and 0.5% by mass of FSO ₃ Li were dissolved, and LiPF ₆ was not dissolved. A sheet-like non-aqueous electrolyte secondary battery No. 5 was produced and evaluated. Table 1 shows the results.

As is clear from Table 1, Examples 1 to 6 are superior to Comparative Examples 1 to 3 in input/output characteristics and cycle capacity retention rate. That is, when the ratio of the content mass of the fluorosulfonate (B) to the content mass of the lithium bisfluorosulfonylimide which is a compound belonging to the group (A) is 1 or less, the input/output characteristics and the cycle capacity retention ratio A good effect is expressed.
In addition, Examples 1 to 6 show good relative output and relative input compared to Comparative Example 5 in which the mass content of lithium bisfluorosulfonylimide, which is a compound belonging to Group (A), exceeds 8% by mass. is also clear.
When 1.0% by mass of lithium methylsulfate, which has a relatively similar structure to the fluorosulfonate (B), was used, the lithium methylsulfate did not dissolve, and a uniform non-aqueous electrolytic solution could not be prepared. From this, even if the compound is structurally similar to the fluorosulfonate (B), it is essential to use the fluorosulfonate (B) to exhibit the effect as described herein. It turns out that

(Example 7)
1.25% by mass of 1,2-ethylene sulfate, 0.75% by mass of FSO ₃ Li, and 13.6% by mass of LiPF ₆ were dissolved, and lithium bisfluorosulfonylimide was not dissolved. A sheet-like non-aqueous electrolyte secondary battery of Example 7 was produced and evaluated in the same manner as in Example 1 except for the above. Table 2 shows the results. Table 2 shows relative values when the value in Comparative Example 6 described later is set to 100.

(Comparative Example 6)
Example 1, except that 2% by mass of 1,2-ethylene sulfate and 13.6% by mass of LiPF ₆ were dissolved, and lithium bisfluorosulfonylimide and FSO ₃ Li were not dissolved. Similarly, a sheet-like non-aqueous electrolyte secondary battery of Comparative Example 6 was produced and evaluated. Table 2 shows the results.

As is clear from Table 2, Example 7 is superior to Comparative Example 6 in input/output characteristics and cycle capacity retention rate. That is, when the ratio of the content mass of fluorosulfonate (B) to the content mass of 1,2-ethylene sulfate, which is a compound belonging to group (A), is 1 or less, the input/output characteristics and the cycle capacity retention rate A good effect is expressed against.

(Example 8)
1.25% by weight of 1,3-propene sultone, 0.75% by weight of FSO ₃ Li, L
In the same manner as in Example 1, except that iPF ₆ was dissolved to 13.6% by mass and lithium bisfluorosulfonylimide was not dissolved, the sheet-shaped non-aqueous electrolytic solution secondary of Example 8 was prepared. A battery was produced and evaluated. Table 3 shows the results. Table 3 shows relative values when the value in Comparative Example 7 described later is set to 100.

(Comparative Example 7)
Same as Example 1, except that 2% by mass of 1,3-propene sultone and 13.6% by mass of _LiPF6 were dissolved, and lithium bisfluorosulfonylimide and _FSO3Li were not dissolved. Then, a sheet-like non-aqueous electrolyte secondary battery of Comparative Example 7 was produced and evaluated. Table 3 shows the results.

As is clear from Table 3, Example 8 is superior to Comparative Example 7 in input/output characteristics and cycle capacity retention rate. That is, when the ratio of the content mass of fluorosulfonate (B) to the content mass of 1,3-propenesultone, which is a compound belonging to group (A), is 1 or less, the input/output characteristics and the cycle capacity retention ratio good effect is exhibited.

According to the non-aqueous electrolyte solution of the present invention, the cycle capacity retention rate during durability such as cycle operation and high temperature storage of the non-aqueous electrolyte secondary battery, input/output characteristics after cycling (input/output retention rate), battery It can improve swelling and is useful. Therefore, the non-aqueous electrolytic solution of the present invention and energy devices such as non-non-aqueous electrolytic solution secondary batteries using the same can be used for various known applications. Specific examples include notebook computers, pen-input computers, mobile computers, e-book players, mobile phones, mobile faxes, mobile copiers, mobile printers, headphone stereos, video movies, liquid crystal televisions, handy cleaners, portable CDs, and minidiscs. , walkie-talkies, electronic notebooks, calculators, memory cards, portable tape recorders, radios, backup power sources, motors, automobiles, motorcycles, motorized bicycles, bicycles, lighting fixtures, toys, game devices, clocks, power tools, strobes, cameras, homes backup power sources for industrial use, backup power sources for business establishments, load leveling power sources, natural energy storage power sources, and the like.

Claims (8)

Formula (1) below:
X—SO ₂ —Y—SO ₂ —Z (1)
[In the formula (1), Y is an organic group containing a nitrogen atom, and is a lithium salt of an imide structure that becomes N-Li. X and Z are a fluorine atom or a hydrocarbon group having 1 to 12 carbon atoms which may contain a fluorine atom. X and Z may be the same or different, and may combine with each other to form a ring structure. When forming a ring structure, either X or Z may be omitted. n is an integer of 1 or more and 2 or less. ]
One or more compounds represented by
Formula (2) below:
( _FSO3 ) _x M (2)
[In formula (2), M is a metal atom, and x is the valence of the metal atom M and is an integer of 1 or more]
A non-aqueous electrolytic solution containing a fluorosulfonate (B) represented by
The ratio of the content of the fluorosulfonate (B) to the content of the compound represented by the formula (1) in the non-aqueous electrolytic solution is 0.083 or more and 1 or less,
A non-aqueous electrolytic solution in which the content of the compound represented by the formula (1) in the non-aqueous electrolytic solution is 0.01% by mass or more and 8% by mass or less (provided that the structure represented by the following formula (8) is (except those containing compounds containing

(In formula (8), R ₁ to R ₃ are organic groups having 1 to 20 carbon atoms which may have a substituent.) The non-aqueous electrolytic solution according to claim 1, wherein the content of said fluorosulfonate (B) in said non-aqueous electrolytic solution is 2% by mass or less. The non-aqueous electrolytic solution according to claim 1 or 2, wherein the fluorosulfonate (B) contains FSO ₃ Li. 4. Any one of claims 1 to 3, wherein _the compound represented by formula (1) is ( _FSO2 ) _2NLi , ( _{CF3SO2 ) 2NLi} or ( _{C2F5SO2 ) 2NLi} . The non-aqueous electrolytic solution according to the item. 5. The non-aqueous electrolytic solution according to any one of claims 1 to 4 , wherein said non-aqueous electrolytic solution contains _LiPF6 . An energy device comprising a plurality of electrodes capable of absorbing and releasing metal ions, and the non-aqueous electrolytic solution according to any one of claims 1 to 5 . 7. The energy device according to claim 6 , wherein the plurality of electrodes capable of intercalating and deintercalating metal ions are a positive electrode and a negative electrode, and the negative electrode comprises a carbonaceous material or a material containing silicon. The energy device according to claim 6 or 7 , wherein the plurality of electrodes capable of intercalating and deintercalating metal ions are a positive electrode and a negative electrode, and the positive electrode contains a transition metal oxide.