JP2020102451A - Non-aqueous electrolyte solution and energy device using the same - Google Patents

Abstract

To provide a non-aqueous electrolyte solution that significantly improves the capacity retention rate, output retention rate, and battery swell during high-temperature storage as compared to conventional techniques.SOLUTION: A non-aqueous electrolyte solution includes a compound represented by a structural formula of P(OR)5 (in the structural formula, each R is an independent hydrocarbon group having 1 to 8 carbon atoms, which may be linear or branched, and may be linked to each other to form a ring structure). Preferably, the content of the compound represented by the structural formula of P(OR)5 is 0.0001 mass% or more and 5 mass% or less with respect to the total amount of the non-aqueous electrolyte solution.SELECTED DRAWING: None

Description

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

Non-aqueous electrolyte secondary battery, electric double layer capacitor, lithium ion capacitor, etc. An energy device using the non-aqueous electrolyte solution has been put into practical use. However, in recent years, the demand for higher performance of energy devices has become higher and higher. It is required to achieve the characteristics at a high level.

So far, the capacity at the time of durability test such as cycle characteristics and storage characteristics of non-aqueous electrolyte secondary batteries, battery swelling, positive electrode metal elution, and as a means for improving safety, positive electrode and negative electrode active material, and Numerous technologies have been studied for various battery constituent elements including non-aqueous electrolytes.
For example, Patent Document 1 discloses a technique of forming a coating film of a phosphorus compound on the surface of a positive electrode by using trialkyl phosphite in an electrolytic solution to improve cycle characteristics of a non-aqueous electrolytic solution secondary battery. There is.

Further, Patent Document 2 discloses a technique of forming a thermally stable reducing film on a negative electrode by using a phosphite ester together with a cyclic carbonic acid ester to improve storage characteristics in a high temperature environment. There is.
In addition, Non-Patent Document 1 reports that use of trimethyl phosphite as an electrolyte improves battery performance such as cycle characteristics, and Li _x PO _y is formed on the positive electrode. It has been suggested that this may be the case.

JP 2001-243981A JP 2004-14351 A Electrochimica Acta, 52(2), 636-642 (2006).

As the demand for higher performance of non-aqueous electrolyte secondary batteries has increased in recent years as described above, further improvement in the performance of non-aqueous electrolyte secondary batteries, namely, during durability such as during cycle operation and storage. There is a demand for improved capacity retention and reduced battery swelling, which is related to improved safety.
However, in the non-aqueous electrolyte battery using the compounds described in Patent Documents 1 and 2 and Non-Patent Document 1 and the electrolytic solution using the same, improvement in capacity retention ratio and output retention ratio during durability and However, it was hard to say that the suppression of battery swelling was still sufficient.

The reason for this is not completely understood at present, but it is speculated as follows. That is, the phosphite ester has a property of being easily electrochemically oxidized on the surface of the positive electrode, and electrons are emitted from the phosphite ester to the positive electrode during film formation, resulting in a decrease in battery capacity.
Further, if the decomposition due to such an oxidation reaction occurs at the time of storage at a high temperature, it may cause gas swelling, which may accelerate the deterioration of the battery at the time of durability or reduce the battery safety.

Further, the side reaction component during high temperature storage may be a solid substance. In this case, it is supposed that the particles are deposited on the surface of the electrode to inhibit the insertion/desorption reaction of lithium ions into the electrode active material.
That is, it becomes a resistance component of lithium ion absorption/desorption of the positive electrode, which deteriorates the charge/discharge characteristics, which causes a decrease in the storage capacity and the storage capacity retention rate, or a decrease in the rate characteristics and the input/output characteristics.
The present invention has been made in view of such background art, and its problem is to improve the durability of energy devices represented by non-aqueous electrolyte secondary batteries, especially capacity maintenance during high temperature storage It is to provide a non-aqueous electrolyte solution that improves the rate, output maintenance rate, and battery swelling.

The present inventor has conducted extensive studies to solve the above problems, and as a result, causes a nonaqueous electrolytic solution containing an electrolyte and a nonaqueous solvent that dissolves the electrolyte to contain a compound having a structure of P(OR) ₅ . As a result, they have found that the capacity retention rate, the output retention rate and the battery swelling at the time of high temperature storage are significantly improved as compared with the prior art, and have completed the present invention.
More specifically, the present inventor has decided to develop a novel non-aqueous electrolyte solution that significantly improves the capacity retention rate, output retention rate, and battery swelling during high-temperature storage as compared with the conventional technology, and therefore, the non-aqueous electrolyte solution has not been used. Focusing on the formation mechanism and elementary reaction rate of the negative electrode coating film of the aqueous electrolyte secondary battery, various studies were conducted on the effects of various compounds and their combinations.

Then, the present inventor has made a novel idea of containing a compound having a structure of P(OR) _{5 in} a non-aqueous electrolyte solution, and has a large capacity, output and battery swelling at the time of durability compared with the conventional art. The technology to improve is built. As a result, the capacity retention rate, output retention rate, and battery swell during high-temperature storage are significantly improved over the conventional art, compared to the conventionally known P(OR) ₃ structure having a phosphite ester structure. The technology to build was built.

That is, the present invention provides the specific embodiments and the like shown in [1] to [6] below.
[1] A nonaqueous electrolytic solution containing a compound represented by the structural formula of P(OR) ₅ . (In the structural formula, each R is an independent hydrocarbon group having 1 to 8 carbon atoms, which may be linear or branched, and may be linked to each other to form a ring structure. )
[2] The content of the compound represented by the structural formula of P(OR) ₅ is 0.0001% by mass or more and 5% by mass or less with respect to the total amount of the non-aqueous electrolyte solution, [1] Non-aqueous electrolyte.

[3] The non-aqueous electrolyte solution is an inorganic lithium halide salt, lithium fluorophosphate salt, lithium tungstate salt, lithium carboxylate salt, lithium sulfonate salt, lithium sulfate salt, lithium imide salt, lithium methide salt, lithium oxalate. The non-aqueous electrolyte solution according to [1] or [2], containing at least one compound selected from the group consisting of a salt salt and a fluorine-containing organic lithium salt.

[4] The non-aqueous electrolyte solution contains LiPF ₆ , and the molar ratio [PF ₆ ] of PF ₆ and P(OR) ₅ is [PF ₆ ].
/[P(OR) ₅ ] is 2.0 or more and 2500 or less, the non-aqueous electrolyte solution according to [1] to [3].

[5] The non-aqueous electrolyte contains at least one compound selected from the group consisting of a saturated cyclic carbonate, a chain carbonate, a chain carboxylic acid ester, a cyclic carboxylic acid ester, an ether compound and a sulfone compound. The non-aqueous electrolyte solution according to any one of [1] to [4].
[6] The non-aqueous electrolytic solution is a cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, a fluorinated unsaturated cyclic carbonate, a cyclic compound having an SO ₂ group, a compound having a cyano group, The non-aqueous electrolyte solution according to any one of [1] to [5], containing at least one compound selected from the group consisting of an isocyanate compound and a carboxylic acid anhydride.

[7] An energy device including a plurality of electrodes capable of inserting and extracting metal ions, and the non-aqueous electrolyte solution according to any one of [1] to [6].

According to the present invention, it is possible to provide a non-aqueous electrolyte solution capable of realizing an energy device such as a non-aqueous electrolyte secondary battery in which the capacity retention rate, the output retention rate during high temperature storage and the battery swelling are significantly improved. it can. Further, according to a preferred embodiment of the present invention, not only input/output characteristics, but also excellent impedance characteristics, charge/discharge rate characteristics, and the like, and further excellent cycle characteristics, high-temperature storage characteristics, continuous charge characteristics, safety, etc. It is possible to provide a non-aqueous electrolyte solution that can realize the above. Moreover, the energy device using this non-aqueous electrolyte can be provided.

The compound represented by the structural formula of P(OR) ₅ has higher oxidation resistance than that of the compound represented by the structural formula of P(OR) ₃ and is less likely to emit electrons to the positive electrode, resulting in a direct capacity decrease. Hateful. In addition, the compound represented by the structural formula of P(OR) ₅ has a nucleophilic reaction-accepting property and can react with an active oxygen atom on the surface of the positive electrode to deactivate the active site, or generate by a side reaction. The nucleophilic compound can be trapped. This suppresses further side reaction on the surface of the positive electrode. The validity of the molecular design based on such an idea is shown in the structural formula of P(OR) _{3 in} Examples 1 and 2 using the compound represented by the structural formula of P(OR) ₅ , as described later. It is also clear from the fact that it is superior in capacity retention ratio, output retention ratio and battery swelling as compared with Comparative Example 2 using the compound described above.

Hereinafter, embodiments of the present invention will be described in detail. The following embodiments are examples (representative examples) of the embodiments of the present invention, and the present invention is not limited thereto. Further, the present invention can be implemented by being arbitrarily modified within the scope of the invention.

<1. Compound Represented by Structural Formula of P(OR) ₅ >
The non-aqueous electrolyte solution which is one embodiment of the present invention contains a compound represented by the structural formula of P(OR) ₅ .
In the structural formula of P(OR) ₅ , R's each independently represent a hydrocarbon group having 1 to 8 carbon atoms, which may be linear or branched and are linked to each other to form a ring structure. It may be. Also,
The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.
Examples of the saturated hydrocarbon group include the structures shown below (* indicates a binding site with the oxygen atom of P(OR) ₅ ).

It is preferable that R is a saturated hydrocarbon group because the cost of the final product can be reduced by using an inexpensive alcohol raw material.
Examples of the unsaturated hydrocarbon group include the following structures and the like (* indicates a bonding site with the oxygen atom of P(OR) ₅ ).

Further, in the compound represented by the structural formula of P(OR) ₅ , when two or more Rs are linked to each other to form a ring structure, the three-dimensional structure of P(OR) ₅ is stabilized and the direction of the reaction site is changed. Properties are easily determined, and cycle characteristics and storage characteristics are easily improved.
Examples of the structure having a saturated hydrocarbon group in the case where two or more Rs are linked to each other to form a ring structure include the following structures (* indicates a bonding site with an oxygen atom of P(OR) ₅ Indicates).

Examples of the structure having an unsaturated hydrocarbon group in the case where two or more Rs are linked to each other to form a ring structure include the following structures (* is a bond with the oxygen atom of P(OR) ₅ ). The site is shown).

When two or more Rs are linked to each other to form a ring structure, the structure having an unsaturated hydrocarbon group traps reactive impurities or polymerizes on the surface of the negative electrode to form a film. It is preferable in that the durability is improved.
Among these, the following structures can be mentioned as structures that are preferable from the viewpoint of procuring raw materials, increase the production efficiency in producing the compound, and can reduce the production load (* indicates P(O
R) ₅ represents the binding site with the oxygen atom).

Specific preferred examples of the compound represented by the structural formula of P(OR) ₅ include:

Are listed. With this structure, the production efficiency at the time of producing the compound is increased, and the production load can be reduced.
Further, among these, as a more preferable compound,

Are listed. With this structure, the balance between reactivity and stability with respect to the positive electrode can be improved, and thus cycle characteristics and storage characteristics are most easily improved.
As the compound represented by the structural formula of P(OR) ₅ , one kind may be used alone, or two or more kinds may be used in optional combination and ratio. Further, the content of the compound represented by the structural formula of P(OR) ₅ is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but when the total amount of the non-aqueous electrolyte solution is 100% by mass. , Usually 0.0001% by mass or more, preferably 0.00
It is 1 mass% or more, more preferably 0.01 mass% or more, and is usually 5 mass% or less, preferably 3 mass% or less, more preferably 2 mass% or less. Within the above range, durability such as cycle capacity, storage capacity and input/output characteristics can be further improved, and battery swelling can be further reduced, which is preferable.

A nuclear magnetic resonance method (NMR) is mentioned as a measuring method of P(OR) ₅ in a non-aqueous electrolyte solution.
When LiPF ₆ described below is included in the non-aqueous electrolyte, PF ₆ and P(OR) _{5 are included.}
The molar ratio [PF ₆ ]/[P(OR) ₅ ] of is not particularly limited, but is usually 2.0 or more, preferably 2.5 or more, more preferably 3.0 or more, and further preferably 4. It is 0 or more, particularly preferably 10 or more, while the upper limit is usually 2500 or less, preferably 2000 or less, more preferably 1000 or less, particularly preferably 300 or less. Within the above range, durability such as cycle capacity, storage capacity and input/output characteristics can be further improved, and battery swelling can be further reduced, which is preferable. Note that the [PF _6], PF ⁶ which LiPF ₆ in a non-aqueous electrolytic solution was ion dissociation - and is the sum of PF ₆ in the association state between the lithium and other ions.

The method for producing the compound having the structure of P(OR) ₅ is not particularly limited, and it can be produced by combining known methods.
For example, the compound represented by the structural formula of P(OR) ₅ is obtained by reacting the corresponding phosphite with the corresponding peroxide, alkoxysulfanyl compound, aldehyde or ketone, and separating and purifying from the resulting mixture. The method of manufacturing is described.

Here, the non-aqueous electrolyte solution containing the compound represented by the structural formula of P(OR) ₅ may be prepared by a known method, and is not particularly limited. For example, a method of adding a separately synthesized compound represented by the structural formula of P(OR) ₅ to a non-aqueous electrolyte, or a method of adding a separately synthesized compound represented by the structural formula of P(OR) ₅ to a solvent A method of dissolving an electrolyte salt to form a non-aqueous electrolyte solution, a battery element (battery element) in which a compound represented by the structural formula of P(OR) ₅ is mixed into a battery constituent element such as an active material and an electrode plate described later. And injecting a non-aqueous electrolyte solution to dissolve a compound represented by the structural formula of P(OR) ₅ in the non-aqueous electrolyte solution when assembling an energy device such as a non-aqueous electrolyte secondary battery. Method, in a non-aqueous electrolyte or non-aqueous electrolyte secondary battery, P
The compound capable of generating the compound represented by the structural formula (OR) ₅ is mixed in advance in the non-aqueous electrolyte solution or the non-aqueous electrolyte secondary battery, and the compound represented by the structural formula P(OR) ₅ is added. Examples thereof include a method of obtaining an electrolytic solution containing the same. In the present invention, either method may be used.

<2. Non-aqueous electrolyte>
<2-1. Electrolyte>
The non-aqueous electrolytic solution in the present invention usually contains an electrolyte as a component thereof, like a general non-aqueous electrolytic solution. One or more lithium salts can be contained as the electrolyte. The lithium salt is not particularly limited as long as it is known to be used as an electrolyte, and any lithium salt can be used. Specific examples thereof include the following.

For example,
_{LiBF 4, LiClO 4, LiAlF 4} , LiPF 6, LiSbF 6, LiTaF 6
An inorganic lithium halide salt such as LiWF ₇ ;
Li ₂ PO ₃ F, such LiPO ₂ F _2, fluorophosphate lithium salts other than LiPF _6;
Lithium tungstate salts such as LiWOF ₅ ;
HCO ₂ Li, CH ₃ CO ₂ Li, CH ₂ FCO ₂ Li, CHF ₂ CO ₂ Li, CF ₃
CO ₂ Li, CF ₃ CH ₂ CO ₂ Li, CF ₃ CF ₂ CO ₂ Li, CF ₃ CF ₂ CF ₂ C
Lithium carboxylic acid salts such as O ₂ Li and CF ₃ CF ₂ CF ₂ CF ₂ CO ₂ Li;
FSO ₃ Li, CH ₃ SO ₃ Li, CH ₂ FSO ₃ Li, CHF ₂ SO ₃ Li, CF _{3
SO 3 Li, CF 3 CF 2} SO 3 Li, CF 3 CF 2 CF 2 SO 3 Li, CF 3 CF 2 C
Lithium sulfonates such as F ₂ CF ₂ SO ₃ Li;

Lithium methyl sulfate, lithium ethyl sulfate, lithium 2-propynyl sulfate, lithium 1-methyl-2-propynyl sulfate, lithium 1,1-dimethyl-2-propynyl sulfate, 2,
Lithium sulfate salts such as 2,2-trifluoroethyl lithium sulfate and dilithium ethylene disulfate;
_{LiN (FCO 2) 2, LiN} (FCO) (FSO 2), LiN (FSO 2) 2, Li
N(FSO ₂ )(CF ₃ SO ₂ ), LiN(CF ₃ SO ₂ ) ₂ , LiN(C ₂ F ₅ SO ₂
) ₂ , lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,
3-perfluoropropanedisulfonylimide, LiN(CF ₃ SO ₂ )(C ₄ F ₉ SO
₂ ) lithium imide salts such as;
Lithium methide salts such as LiC(FSO ₂ ) ₃ , LiC(CF ₃ SO ₂ ) ₃ and LiC(C ₂ F ₅ SO ₂ ) ₃ ;

Lithium difluorooxalato borate, lithium bis(oxalato)borate, lithium tetrafluorooxalato phosphate, lithium difluorobis(oxalato)
Lithium oxalate salts such as phosphates and lithium tris(oxalato)phosphates;
In addition, LiPF ₄ (CF ₃ ) ₂ , LiPF ₄ (C ₂ F ₅ ) ₂ , LiPF ₄ (CF ₃ S
_{O 2) 2, LiPF 4 (} C 2 F 5 SO 2) 2, LiBF 3 CF 3, LiBF 3 C 2 F 5,
_{LiBF 3 C 3 F 7, LiBF} 2 (CF 3) 2, LiBF 2 (C 2 F 5) 2, LiBF 2
Fluorine-containing organic lithium salts such as (CF ₃ SO ₂ ) ₂ and LiBF ₂ (C ₂ F ₅ SO ₂ ) ₂ ;
Etc.

Among these, inorganic lithium salts, lithium fluorophosphate salts, sulfone, from the viewpoint of further enhancing the effect of improving input/output characteristics, charge/discharge rate charge/discharge characteristics, and impedance characteristics after endurance tests such as high temperature storage tests and cycle tests. Those selected from acid lithium salts, lithium imide salts, and lithium oxalate salts are preferable.
Among them, LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiTaF ₆ , Li ₂ PO ₃ F, L
iPO ₂ F ₂ , FSO ₃ Li, CF ₃ SO ₃ Li, LiN(FSO ₂ ) ₂ , LiN(FS
_{O 2) (CF 3 SO 2} ), LiN (CF 3 SO 2) 2, LiN (C 2 F 5 SO 2) 2, lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-Par Fluoropropane disulfonylimide, LiC(FSO ₂ ) ₃ , LiC(CF ₃ SO ₂ ).
₃ , LiC(C ₂ F ₅ SO ₂ ) ₃ , lithium difluorooxalatoborate, lithium bis(oxalato)borate, lithium tetrafluorooxalatophosphate, lithium difluorobis(oxalato)phosphate and lithium tris(oxalato)phosphate However, it is particularly preferable because it has an effect of improving input/output characteristics, high rate charge/discharge characteristics, impedance characteristics, high temperature storage characteristics, cycle characteristics, and the like.

The total concentration of these electrolytes in the non-aqueous electrolyte solution is not particularly limited, but is usually 8% by mass or more, preferably 8.5% by mass or more, more preferably when the total amount of the non-aqueous electrolyte solution is 100% by mass. Is 9% by mass or more. The upper limit is usually 18% by mass or less, preferably 17% by mass.
Or less, more preferably 16 mass% or less. When the total concentration of the electrolyte is within the above range, the electric conductivity becomes appropriate for battery operation, which is preferable.

Further, these electrolytes may be used alone or in combination of two or more kinds. A preferable example of using two or more kinds in combination is LiPF ₆ and LiBF ₄ , LiPF ₆ and LiPO ₂ F ₂ ,
LiPF ₆ and FSO ₃ Li, LiPF ₆ and LiN(FSO ₂ ) ₂ , LiPF ₆ and LiN(
_{CF 3 SO 2) 2, LiPF} 6 , lithium bis (oxalato) borate, LiPF ₆ and lithium tetrafluoro-oxa Lato phosphate, LiPF ₆ and lithium difluoro (oxalato) phosphate, LiPF ₆ and LiBF ₄ and LiPO ₂ F ₂ , LiPF ₆
And LiBF ₄ , FSO ₃ Li, LiPF ₆ , LiPO ₂ F ₂ , FSO ₃ Li, LiPF ₆
And LiPO ₂ F ₂ and lithium bis(oxalato)borate, LiPF ₆ and LiPO ₂ F ₂
And lithium difluorobis(oxalato)phosphate, LiPF ₆ and LiPO ₂ F ₂
And LiN(FSO ₂ ) ₂ , LiPF ₆ , LiPO ₂ F ₂ , LiN(CF ₃ SO ₂ ) ₂ , L
iPF ₆ , FSO ₃ Li and lithium bis(oxalato)borate, or LiPF ₆ and FS
It is a combination of O ₃ Li and lithium difluorobis(oxalato)phosphate, and has an 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 solution is preferably 7% by mass or more, more preferably 7.5% by mass or more,
It is more preferably 8% by mass or more, preferably 16% by mass or less, more preferably 15% by mass or less, still more preferably 14% by mass or less, and LiBF ₄ , LiPO ₂ F ₂ , FSO ₃
The content of Li, LiN(FSO ₂ ) ₂ LiN(CF ₃ SO ₂ ) ₂ , lithium bis(oxalato)borate, or lithium difluorobis(oxalato)phosphate is preferably 0.01 mass in the non-aqueous electrolyte solution. % Or more, more preferably 0.05% by mass or more, further 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 or less. When the concentration of LiPF ₆ is within the above-mentioned preferred range, the total ion content in the non-aqueous electrolyte solution and the viscosity are in an appropriate balance, so that the battery internal impedance is lowered without excessively decreasing the ionic conductivity, The effect of improving the input/output characteristics, cycle characteristics, and storage characteristics due to the addition of LiPF ₆ is more likely to be exhibited.

A particularly preferred combination as the electrolyte is a combination of LiPF ₆ and LiPO ₂ F ₂ . By combining these with a compound having a structure of P(OR) ₅ , there is a tendency that the elution of the transition metal oxide from the positive electrode can be effectively suppressed.
These electrolyte materials can be manufactured by a conventionally known method.
Here, the preparation of the non-aqueous electrolytic solution containing the electrolyte material may be performed by a known method,
It is not particularly limited. For example, a battery element (battery element) is constructed by a method of adding the separately synthesized electrolyte material to a non-aqueous electrolyte solution or by mixing the electrolyte material in a battery constituent element such as an active material or an electrode plate described later. Place, a method of dissolving the electrolyte material in a non-aqueous electrolyte when assembling a battery by injecting a non-aqueous electrolyte, active material and electrode plate, water coexist in the battery components such as the separator, Examples include a method of generating another electrolyte material in the system when a non-aqueous electrolyte solution secondary battery is assembled using the non-aqueous electrolyte solution containing the above electrolyte material. In the present invention, either method may be used.

The method for measuring the content of each electrolyte in the non-aqueous electrolyte solution and the non-aqueous electrolyte secondary battery is not particularly limited, and any known method can be used. Specific examples thereof include ion chromatography and ¹⁹ F nuclear magnetic resonance spectroscopy (hereinafter sometimes referred to as “NMR”).

<2-2. Non-aqueous solvent>
The non-aqueous electrolytic solution according to one embodiment of the present invention usually contains, as a main component, a non-aqueous solvent that dissolves the above-mentioned electrolyte, like a general non-aqueous electrolytic solution. The non-aqueous solvent used here is not particularly limited, and a known organic solvent can be used. Examples of the organic solvent include saturated cyclic carbonate, chain carbonate, chain carboxylic acid ester, cyclic carboxylic acid ester, ether compound, sulfone compound, and the like, but are not particularly limited thereto. These may be used alone or in combination of two or more.
Further, in one embodiment of the present invention, it is preferable that the non-aqueous electrolyte solution contains at least one member selected from the group consisting of cyclic carbonates, chain carbonates, and chain esters.

<2-2-1. Saturated cyclic carbonate>
Examples of the saturated cyclic carbonate include those having an alkylene group having 2 to 4 carbon atoms.
Specifically, as the saturated cyclic carbonate having 2 to 4 carbon atoms, ethylene carbonate,
Examples include propylene carbonate and butylene carbonate. Among them, ethylene carbonate and propylene carbonate are preferable from the viewpoint of improving the battery characteristics resulting from the improvement in the degree of lithium ion dissociation. As the saturated cyclic carbonate, one kind may be used alone, and two kinds or more may be used in optional combination and ratio.

The content of the saturated cyclic carbonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but the lower limit of the content when one type is used alone is usually 100% by volume of the non-aqueous solvent, 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 solution, and to improve the large-current discharge characteristics of the non-aqueous electrolyte secondary battery, the stability against the negative electrode, and the cycle characteristics. It becomes easy to set the range. The upper limit is usually 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By setting this range, the viscosity of the non-aqueous electrolyte solution can be adjusted to an appropriate range, the decrease in ionic conductivity can be suppressed, and the input/output characteristics of the non-aqueous electrolyte secondary battery can be further improved, and the cycle characteristics and storage characteristics can be improved. It is preferable because durability such as characteristics can be further improved.

Further, the saturated cyclic carbonate may be used in any combination of two or more kinds.
One of the preferred combinations is ethylene carbonate and propylene carbonate. In this case, the volume ratio of ethylene carbonate and propylene carbonate is 99:
It is preferably 1 to 40:60, more preferably 95:5 to 50:50. Further, the lower limit of the amount of propylene carbonate in the whole non-aqueous solvent is usually 1% by volume or more, preferably 2% by volume or more, more preferably 3% by volume or more. The upper limit is usually 30% by volume.
It is preferably 25% by volume or less, more preferably 20% by volume or less. It is preferable to contain propylene carbonate in this range because the low temperature characteristics will be further excellent.

<2-2-2. Chain carbonate>
The chain carbonate preferably has 3 to 7 carbon atoms.
Specifically, as the chain carbonate having 3 to 7 carbon atoms, 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 can be mentioned.

Among them, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethylmethyl carbonate or methyl-n-propyl carbonate is preferable, and dimethyl carbonate, diethyl carbonate or ethylmethyl carbonate is particularly preferable. is there.
Further, chain carbonates having a fluorine atom (hereinafter, "fluorinated chain carbonate"
May be abbreviated. ) Can also be preferably used. The number of fluorine atoms contained in the fluorinated chain carbonate is not particularly limited as long as it is 1 or more, but is usually 6 or less, and preferably 4 or less. When the fluorinated chain carbonate has a plurality of fluorine atoms, they may be bonded to the same carbon or different carbons. Examples of the fluorinated chain carbonate include fluorinated dimethyl carbonate derivatives, fluorinated ethyl methyl carbonate derivatives, fluorinated diethyl carbonate derivatives and the like.

As the fluorinated dimethyl carbonate derivative, fluoromethyl methyl carbonate,
Difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, bis (
Examples thereof include fluoromethyl)carbonate, bis(difluoro)methyl carbonate, bis(trifluoromethyl)carbonate and the like.
Examples of the fluorinated ethyl methyl carbonate derivative include 2-fluoroethyl methyl carbonate, ethyl fluoromethyl carbonate, 2,2-difluoroethyl methyl carbonate, 2-fluoroethyl fluoromethyl carbonate, ethyl difluoromethyl carbonate, 2,2,2-trifluoromethyl carbonate. Examples thereof include fluoroethyl methyl carbonate, 2,2-difluoroethyl fluoromethyl carbonate, 2-fluoroethyl difluoromethyl carbonate and ethyl trifluoromethyl carbonate.

Examples of the fluorinated diethyl carbonate derivative 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, etc. are mentioned.

As the chain carbonate, one kind may be used alone, and two kinds or more may be used in optional combination and ratio.
Although the content of the chain carbonate is not particularly limited, it is usually 15% in 100% by volume of the non-aqueous solvent.
It is not less than 20% by volume, preferably not less than 25% by volume, more preferably not less than 20% by volume.
Further, 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 to an appropriate range, the decrease in the ionic conductivity is suppressed, and thus the input/output characteristics and charge/discharge of the non-aqueous electrolyte secondary battery. It is easy to set the rate characteristic in a good range. Further, it is possible to avoid a decrease in electric conductivity due to a decrease in dielectric constant of the non-aqueous electrolyte solution, and it is easy to set the input/output characteristics and the charge/discharge rate characteristics of the non-aqueous electrolyte secondary battery in a favorable range.

Furthermore, by combining ethylene carbonate with a specific chain carbonate in a specific content, the battery performance can be significantly improved.
For example, when dimethyl carbonate and ethyl methyl carbonate are selected as the specific chain carbonates, the content of ethylene carbonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but 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 ethylmethyl 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. When the content is within the above range, the low temperature precipitation temperature of the electrolyte is lowered, the viscosity of the non-aqueous electrolyte solution is also lowered, the ionic conductivity is improved, and high input/output can be obtained even at a low temperature.

<2-2-3. Chain carboxylic acid ester>
Examples of the chain carboxylic acid ester 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, propionic acid-n-
Butyl, isobutyl propionate, t-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, isobutyrate n-propyl, isopropyl isobutyrate and the like can be mentioned. ..

Among them, methyl acetate, ethyl acetate, acetic acid-n-propyl acetate, acetic acid-n-butyl, methyl propionate, ethyl propionate, propionate-n-propyl, isopropyl propionate, methyl butyrate or ethyl butyrate is an ion due to viscosity decrease. It is preferable from the viewpoint of improving conductivity and suppressing battery swelling during durability such as cycling and storage.
The content of the chain carboxylic acid ester is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 5% by volume or more, preferably 8% by volume in 100% by volume of the non-aqueous solvent.
It is at least 80% by volume, and preferably 70% by volume or less. When the content of the chain carboxylic acid ester is within the above range, the electric conductivity of the non-aqueous electrolyte solution is improved, and the input/output characteristics and charge/discharge rate characteristics of the non-aqueous electrolyte secondary battery are easily improved. Further, it is possible to suppress the increase of the negative electrode resistance and easily set the input/output characteristics and the charge/discharge rate characteristics of the non-aqueous electrolyte secondary battery in a favorable range.

When a chain carboxylic acid ester is used, it is preferably used in combination with a cyclic carbonate, and more preferably used 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 the effect of the present invention is not significantly impaired, but is usually 15% by volume or more, preferably 20% by volume. % By volume, 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. When the cyclic carbonate, the chain carbonate and the chain carboxylic acid ester are used in combination, the content of the cyclic carbonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but 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, while lowering the low temperature deposition temperature of the electrolyte, the viscosity of the non-aqueous electrolyte solution is also reduced to improve the ionic conductivity, and higher input/output can be obtained even at low temperature, It is also preferable from the viewpoint of further reducing the battery swelling.

<2-2-4. Cyclic carboxylic acid ester>
Examples of the cyclic carboxylic acid ester include those having a total number of carbon atoms of 3 to 12 in the structural formula.
Specifically, gamma butyrolactone, gamma valerolactone, gamma caprolactone,
Epsilon caprolactone and the like can be mentioned. Among them, gamma-butyrolactone is particularly preferable from the viewpoint of improving the battery characteristics resulting from the improvement in the degree of lithium ion dissociation.

The content of the cyclic carboxylic acid ester is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 3% by volume or more, preferably 5% by volume in 100% by volume of the non-aqueous solvent.
It is above, 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 electric conductivity of the non-aqueous electrolyte solution 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, the decrease of the electric conductivity is avoided, the increase of the negative electrode resistance is suppressed, and the input/output characteristics and charge/discharge rate characteristics of the non-aqueous electrolyte secondary battery are set in a good range. And easy to do.

<2-2-5. Ether compounds>
As the ether compound, a chain ether having 3 to 10 carbon atoms and a cyclic ether having 3 to 6 carbon atoms are preferable.
As the chain ether having 3 to 10 carbon atoms, diethyl ether, di(2-fluoroethyl)ether, di(2,2-difluoroethyl)ether, di(2,2,2-trifluoroethyl)ether, ethyl (2-Fluoroethyl) ether, ethyl (2,2,2-trifluoroethyl) ether, ethyl (1,1,2,2-tetrafluoroethyl) ether, (2-fluoroethyl) (2,2,2 -Trifluoroethyl)ether, (2-fluoroethyl)(1,1,2,2-tetrafluoroethyl)ether, (2,2,2-trifluoroethyl)(1,1,2,2-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 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)
3-pentafluoro-n-propyl) ether, di-n-butyl ether, dimethoxymethane, methoxyethoxymethane, methoxy(2-fluoroethoxy)methane, methoxy(
2,2,2-trifluoroethoxy)methane methoxy(1,1,2,2-tetrafluoroethoxy)methane, diethoxymethane, ethoxy(2-fluoroethoxy)methane, ethoxy(2,2,2-trifluoro Ethoxy)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-trifluoroethoxy)ethane, (2- Fluoroethoxy) (1,1,
2,2-tetrafluoroethoxy)ethane, di(2,2,2-trifluoroethoxy)ethane, (2,2,2-trifluoroethoxy)(1,1,2,2-tetrafluoroethoxy)ethane, Examples include di(1,1,2,2-tetrafluoroethoxy)ethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether.

As the cyclic ether having 3 to 6 carbon atoms, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-methyl-1,3-dioxane, 1 , 4-dioxane and the like, and fluorinated compounds thereof.
Among these, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, or diethylene glycol dimethyl ether has a high solvating ability for lithium ions and has an ionic dissociation property. It is preferable in terms of improvement. Particularly preferred is dimethoxymethane, diethoxymethane or ethoxymethoxymethane because it has low viscosity and gives high ionic conductivity.

The content of the ether compound is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 1 volume% or more, preferably 2 volume% or more in 100 volume% of the non-aqueous solvent.
More preferably 3% by volume or more, and usually 30% by volume or less, preferably 25% by volume or less,
It is more preferably 20% by volume or less. When the content of the ether compound is within the above-mentioned preferred range, it is easy to secure the effect of improving the lithium ion dissociation degree of the chain ether and the effect of improving the ionic conductivity resulting from the decrease in viscosity. Further, when the negative electrode active material is a carbonaceous material, the phenomenon that chain ethers are co-inserted with 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 compounds>
As the sulfone compound, a cyclic sulfone having 3 to 6 carbon atoms and a chain sulfone having 2 to 6 carbon atoms are preferable. The number of sulfonyl groups in one molecule is preferably 1 or 2.
Examples of the cyclic sulfone include trimethylenesulfones, tetramethylenesulfones, and hexamethylenesulfones, which are monosulfone compounds; trimethylenedisulfones, tetramethylenedisulfones, and hexamethylenedisulfones, which are disulfone compounds. Of these, from the viewpoint of dielectric constant and viscosity, tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones or hexamethylene disulfones are more preferable, and tetramethylene sulfones (sulfolanes) are particularly preferable.

As the sulfolanes, sulfolane and/or sulfolane derivatives (hereinafter, sometimes referred to as "sulfolanes" including sulfolane) are preferable. The sulfolane derivative is preferably a sulfolane derivative in which one or more hydrogen atoms bonded to carbon atoms constituting the sulfolane ring are substituted with a fluorine atom or an alkyl group.
Among them, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3
-Fluorosulfolane, 2,2-difluorosulfolane, 2,3-difluorosulfolane, 2,4-difluorosulfolane, 2,5-difluorosulfolane, 3,4-difluorosulfolane, 2-fluoro-3-methylsulfolane, 2- Fluoro-2-methylsulfolane, 3-fluoro-3-methylsulfolane, 3-fluoro-2-methylsulfolane, 4-
Fluoro-3-methylsulfolane, 4-fluoro-2-methylsulfolane, 5-fluoro-3-methylsulfolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane, 3-fluoromethylsulfolane, 2-difluoromethyl Sulfolane, 3-difluoromethylsulfolane, 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 high ionic conductivity and high input/output.

As the chain sulfone, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, n-propyl ethyl sulfone, di-n-propyl sulfone, isopropyl methyl sulfone, isopropyl ethyl sulfone, diisopropyl sulfone, n- Butyl methyl sulfone, n-butyl ethyl sulfone, t-butyl methyl sulfone, t-butyl ethyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, Trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, perfluoroethyl methyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di(tri Fluoroethyl) sulfone, perfluorodiethyl sulfone, fluoromethyl-n-propyl sulfone, difluoromethyl-n-propyl sulfone, trifluoromethyl-n-
Propyl sulfone, fluoromethyl isopropyl sulfone, difluoromethyl isopropyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl-n-propyl sulfone, trifluoroethyl isopropyl sulfone, pentafluoroethyl-n-
Propyl sulfone, pentafluoroethyl isopropyl sulfone, trifluoroethyl-
Examples thereof include n-butyl sulfone, trifluoroethyl-t-butyl sulfone, pentafluoroethyl-n-butyl sulfone and pentafluoroethyl-t-butyl sulfone.

Among them, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, isopropyl methyl sulfone, n-butyl methyl sulfone, t-butyl methyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone. , Monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoro Ethyl sulfone, trifluoromethyl-n-propyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl-n-butyl sulfone, trifluoroethyl-t-butyl sulfone, trifluoromethyl-n-butyl sulfone 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 the effect of the present invention is not significantly impaired, but is usually 0.3 vol% or more, preferably 0.5 vol% in 100 vol% of the non-aqueous solvent. Or more, more preferably 1 volume% or more, and usually 40 volume% or less, preferably 3
It is 5% by volume or less, more preferably 30% by volume or less. If the content of the sulfone compound is within the above range, the effect of improving durability such as cycle characteristics and storage characteristics is easily obtained, and
It is possible to set the viscosity of the non-aqueous electrolyte solution in an appropriate range, avoid a decrease in electrical conductivity, and set the input/output characteristics and charge/discharge rate characteristics of the non-aqueous electrolyte secondary battery in an appropriate range.

<2-3. Auxiliary>
The non-aqueous electrolyte solution of the present invention may further contain various auxiliaries detailed below.
<2-3-1. Carbonate having at least one of a carbon-carbon unsaturated bond and a fluorine atom>
The non-aqueous electrolyte 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.

Examples of the carbonate having a carbon-carbon unsaturated bond include a cyclic carbonate having a carbon-carbon unsaturated bond (hereinafter, may be abbreviated as "unsaturated cyclic carbonate"), and a carbonate having a fluorine atom. As a preferable example, a cyclic carbonate having a fluorine atom can be mentioned.
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. The 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 a known method can be arbitrarily selected and produced.

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.
Examples of vinylene carbonates include vinylene carbonate, methylvinylene carbonate, 4,5-dimethylvinylene carbonate, phenylvinylene carbonate and 4,5-
Diphenyl vinylene carbonate, vinyl vinylene carbonate, allyl vinylene carbonate, etc. are mentioned.

Specific examples of the ethylene carbonate substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond include vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate, phenyl ethylene carbonate, 4,5-diphenyl ethylene carbonate, Examples thereof include ethynyl ethylene carbonate and 4,5-diethynyl ethylene carbonate.
Among them, vinylene carbonates, ethylene carbonate substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond are preferable, and particularly vinylene carbonate, 4,5-diphenylvinylene carbonate, 4,5-dimethylvinylene carbonate, vinyl. Ethylene carbonate or ethynyl ethylene carbonate is more preferably used because it forms a stable interface protective film.

The molecular weight of the unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. The molecular weight of the unsaturated cyclic carbonate is usually 50 or more, preferably 80.
Above, it is usually 250 or less, preferably 150 or less. Within this range, the solubility of the unsaturated cyclic carbonate in the non-aqueous electrolyte solution can be easily ensured, and the effects of the present invention can be sufficiently exhibited.

As the unsaturated cyclic carbonate, one kind may be used alone, or two kinds or more may be used in optional combination and ratio. Further, the content of the unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired. The content of the unsaturated cyclic carbonate is usually 0.001% by mass or more, preferably 0.01% by mass or more, and more preferably 0.1% by mass or more in 100% by mass of the non-aqueous electrolyte solution. 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 is likely 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.
Examples of the fluorinated cyclic carbonate include derivatives of cyclic carbonates having an alkylene group having 2 to 6 carbon atoms, such as ethylene carbonate derivatives. Examples of the ethylene carbonate derivative include ethylene carbonate or a fluorinated product of ethylene carbonate substituted with an alkyl group (for example, an alkyl group having 1 to 4 carbon atoms), and among them, 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-dimethylethylene carbonate, 4,4-difluoro-5,5
-Dimethyl ethylene carbonate etc. are mentioned.

Among them, at least one selected from the group consisting of monofluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4,5-difluoroethylene carbonate and 4,5-difluoro-4,5-dimethylethylene carbonate has high ionic conductivity. It is more preferable in terms of imparting properties and suitably forming an interfacial protective film.
As the fluorinated cyclic carbonate, one kind may be used alone, and two kinds or more may be used in optional combination and ratio. The content of the fluorinated cyclic carbonate is not particularly limited,
Although it is optional as long as the effect of the present invention is not significantly impaired, it is usually 0.001% by mass or more, preferably 0.01% by mass or more, and more preferably 0.1% by mass in 100% by mass of the non-aqueous electrolyte solution. It is at least 8% by mass, usually 6% by mass or less, more preferably 5% by mass or less. Within this range, the non-aqueous electrolyte secondary battery is likely to exhibit sufficient cycle characteristics and high temperature storage characteristics. Within this range, the non-aqueous electrolyte secondary battery is likely to exhibit sufficient cycle characteristics and high temperature storage characteristics.

The fluorinated cyclic carbonate may be used as an auxiliary agent of the non-aqueous electrolyte solution or a non-aqueous solvent. When used as a non-aqueous solvent, the content of fluorinated cyclic carbonate,
In 100% by mass of the non-aqueous electrolyte, it is usually 8% by mass or more, preferably 10% by mass or more, more preferably 12% by mass or more, and usually 85% by mass or less, preferably 80% by mass. % Or less, and more preferably 75% by mass or less. Within this range, it is easy for the non-aqueous electrolyte secondary battery to exhibit a sufficient effect of improving cycle characteristics, and it is easy to prevent the discharge capacity retention rate from decreasing.
In the non-aqueous electrolyte according to one embodiment of the present invention, the carbonate having at least one of the carbon-carbon unsaturated bond and a fluorine atom, a group consisting of vinylene carbonate, vinylethylene carbonate, ethynylethylene carbonate, and fluoroethylene carbonate. It is preferably at least one selected from the above.

<2-3-2. Fluorinated unsaturated cyclic carbonate>
As the fluorinated cyclic carbonate, a cyclic carbonate having an unsaturated bond and a fluorine atom (hereinafter, may be abbreviated as “fluorinated unsaturated cyclic carbonate”) can be used. The fluorinated unsaturated cyclic carbonate is not particularly limited. Among them, one having 1 or 2 fluorine atoms is preferable. The method for producing the fluorinated unsaturated cyclic carbonate is not particularly limited, and a known method can be arbitrarily selected and produced.

Examples of the fluorinated unsaturated cyclic carbonate include a vinylene carbonate derivative, an ethylene carbonate derivative substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond, and the like.
Examples of the vinylene carbonate derivative include 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, and 4,5-difluoroethylene carbonate.

Examples of the ethylene carbonate derivative 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 and 4,4-difluoro-4. -Vinyl ethylene carbonate, 4
,5-difluoro-4-vinylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate,
4-fluoro-4-phenylethylene carbonate, 4-fluoro-5-phenylethylene carbonate, 4,4-difluoro-5-phenylethylene carbonate, 4,5-difluoro-4-phenylethylene carbonate and the like can be mentioned.

The molecular weight of the fluorinated unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. The molecular weight 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, the solubility of the fluorinated cyclic carbonate in the non-aqueous electrolyte solution can be easily ensured, and the effects of the present invention can be easily exhibited.

As the fluorinated unsaturated cyclic carbonate, one kind may be used alone, and two kinds or more may be used in optional combination and ratio. Further, the content of the fluorinated unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired. 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 electrolyte solution, and It is usually 5% by mass or less, preferably 4% by mass or less, and more preferably 3% by mass or less. Within this range, the non-aqueous electrolyte secondary battery is likely to exhibit a sufficient cycle characteristic improving effect.

<2-3-3. Cyclic compound having SO ₂ group>
In the non-aqueous electrolytic solution of the present invention, the cyclic compound having an SO ₂ group which can be used, particularly the kind as long as the cyclic compound having an SO ₂ group in the molecule is not limited,
A compound having a cyclic sulfonic acid ester or a cyclic sulfuric acid ester (hereinafter, may be abbreviated as a cyclic sulfonic acid ester compound or a cyclic sulfuric acid ester compound, respectively) 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 ₂ group is not particularly limited, and a known method can be arbitrarily selected and produced.

In formula (3), R ⁷ and R ⁸ are each independently an organic group composed of an atom 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. Represents a group, and R ⁷ and R ⁸ may each include —O—SO ₂ — together with an unsaturated bond.
Here, R ⁷ and R ⁸ are preferably an organic group composed of an atom consisting of a carbon atom, a hydrogen atom, an oxygen atom, and a sulfur atom, and among them, a hydrocarbon group having 1 to 3 carbon atoms,
It is preferably an organic group having O—SO ₂ —.

The molecular weight of the SO ₂ group-containing cyclic compound is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. The molecular weight of the SO ₂ group-containing cyclic compound is usually 100 or more, preferably 110 or more, and is usually 250 or less, preferably 220 or less. Within this range, the solubility of the cyclic compound having an SO ₂ group in the non-aqueous electrolyte solution can be easily ensured and the effect of the present invention can be easily exhibited.

Specific examples of the compound represented by the general formula (3) include, for example,
1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, 1-methyl-
1,3-propane sultone, 2-methyl-1,3-propane sultone, 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- Butane sultone, 2-methyl-1,4-butane sultone, 3-methyl-1,4-butane sultone, 4-methyl-1,4-butane sultone, 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, Four
-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-dioxide-4-yl-acetate, 1
,2-Oxathiolane-2,2-dioxide-4-yl-propionate, 5-methyl-
1,2-oxathiolane-2,2-dioxide-4-one-2,2-dioxide, 5,5
A sultone compound such as dimethyl-1,2-oxathiolane-2,2-dioxide-4-one-2,2-dioxide;

Disulfonate compounds such as methylene methane disulfonate and ethylene methane disulfonate;
1,2,3-oxathiazolidine-2,2-dioxide, 3-methyl-1,2,3-oxathiazolidine-2,2-dioxide, 3H-1,2,3-oxathiazole-2,2
-Dioxide, 5H-1,2,3-oxathiazole-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-
Nitrogen-containing compounds such as 1,2,6-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 Aphoslane-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-oxathiaphoslane-2,2,5-trioxide, 5-methoxy -1
,2,5-oxathiaphoslane-2,2,5-trioxide, 1,2,3-oxathiaphosphinane-2,2-dioxide, 3-methyl-1,2,3-oxathiaphosphinan-
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 -Dioxathiaphosphinan-2,4-dioxide, 4-methoxy-1,5,2,4-dioxathiaphosphinan-2,4-dioxide, 3-methoxy-1,2,4-oxathiaphos Finane-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 −
Oxathiaphosphinan-2,2-dioxide, 6-methyl-1,2,6-oxathiaphosphinan-2,2-dioxide, 6-methyl-1,2,6-oxathiaphosphinan-
2,2,3-trioxide, 6-methoxy-1,2,6-oxathiaphosphinane-2,
A phosphorus-containing compound such as 2,3-trioxide;

1,2-ethylene sulphate, 1,2-propylene sulphate, 1,3-propylene sulphate, 1,2-butylene sulphate, 1,3-butylene sulphate, 1,
Alkylene sulfates such as 4-butylene sulphate, 1,2-pentylene sulphate, 1,3-pentylene sulphate, 1,4-pentylene sulphate and 1,5-pentylene sulphate, vinylene sulphate Compound;
Etc.

Of these, 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, 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 sulphate, 1,2-propylene sulphate or 1,3-propylene sulphate are preferred from the viewpoint of improving storage characteristics. , 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, 1-propene-1,3-sultone ,
More preferred are methylene methane disulfonate, ethylene methane disulfonate, 1,2-ethylene sulphate or 1,3-propylene sulphate.

As the cyclic compound having an SO ₂ group, one type may be used alone, or two or more types may be used in optional combination and ratio. There is no limitation on the content of the cyclic compound having an SO ₂ group with respect to the entire non-aqueous electrolyte solution of the present invention, and it is arbitrary as long as the effect of the present invention is not significantly impaired, but with respect to the non-aqueous electrolyte solution of the present invention, usually 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, further preferably 0.3 mass% or more, and usually 10 mass% or less, preferably 5 mass% or less. , And more preferably at a concentration of 3 mass% or less. When the above range is satisfied, cycle characteristics, high temperature storage characteristics and the like are improved, and battery swelling is reduced, which is preferable.

<2-3-4. Compound Having Cyano Group>
In the non-aqueous electrolyte 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, but in the following general formula (4) The compounds represented are more preferred. The method for producing the compound having a cyano group is not particularly limited, and a known method can be arbitrarily selected and produced.

In the general formula (4), T represents an organic group composed of an atom selected from the group consisting of carbon atom, hydrogen atom, nitrogen atom, oxygen atom, sulfur atom, phosphorus atom and halogen atom, and U is 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, Ts 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 the effects of the present invention are not significantly impaired. 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, the solubility of the compound having a cyano group in the non-aqueous electrolyte solution can be easily ensured and the effect of the present invention can be easily 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-butene nitryl, 2-pentenenitrile, 2-methyl-2-pentenenitrile, 3-methyl-2-pentenenitrile, 2-hexenenitrile,
Fluoroacetonitrile, 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-propanetricarbonitrile, 1,3,5-pentanetricarbonitrile,
Compounds having one cyano group such as pentafluoropropionitrile;

Malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile, dodecanedinitrile, methylmalononitrile, ethylmalononitrile, isopropylmalononitrile, tert-butylmalononitrile, methylsuccinonitrile. , 2,2-dimethylsuccinonitrile, 2,3-dimethylsuccinonitrile, trimethylsuccinonitrile,
Tetramethylsuccinonitrile, 3,3′-(ethylenedioxy)dipropionitrile,
A compound having two cyano groups such as 3,3′-(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 methyl cyanate, ethyl cyanate, propyl cyanate, butyl cyanate, pentyl cyanate, hexyl cyanate, and heptyl cyanate;
Methyl thiocyanate, ethyl thiocyanate, propyl thiocyanate, butyl thiocyanate, pentyl thiocyanate, hexyl thiocyanate, heptyl thiocyanate, methanesulfonyl cyanide, ethanesulfonylcyanide, propanesulfonylcyanide, butanesulfonylcyanide, pentanesulfonylcyanide, hexanesulfonylcyanide , Heptanesulfonyl cyanide, methylsulfurocyanidate, ethylsulfurocyanidate, propylsulfurocyanidate, butylsulfurocyanidate, pentylsulfurocyanidate, hexylsulfurocyanidate, heptylsulfur Sulfur-containing compounds such as furocyanidates;

Cyanodimethylphosphine, cyanodimethylphosphine oxide, methyl cyanomethylphosphinate, methyl cyanomethylphosphinite, cyanide dimethylphosphinic acid, cyanide dimethylphosphinate, dimethyl cyanophosphonate, dimethylcyanophosphonate, cyanomethyl methylphosphonate, methylphosphonate Phosphorus-containing compounds such as cyanomethyl phosphate and cyanodimethyl phosphate cyanodimethyl phosphite;
Etc.

Of these, acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile, crotononitrile, 3-
Methylcrotononitrile, malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile or dodecanedinitrile are preferred from the viewpoint of improving storage properties, and have two cyano groups, malononitrile, Succinonitrile, glutaronitrile, adiponitrile,
More preferred are pimelonitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile, or dodecanedinitrile.

As the compound having a cyano group, one kind may be used alone, and two kinds or more may be used in optional combination and ratio. The content of the compound having a cyano group with respect to the entire non-aqueous electrolyte solution of the present invention is not limited and may be any amount as long as the effect of the present invention is not significantly impaired. 001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, further preferably 0.3% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, Preferably, it is contained at a concentration of 3% by mass or less. When the above range is satisfied, the effects such as input/output characteristics, charge/discharge rate characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

<2-3-5. Isocyanate compound>
In the non-aqueous electrolyte solution of the present invention, the compound having an isocyanate group that can be used (hereinafter, may be 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.

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

In the above general formula (5), X may have a cyclic structure and has 1 or more carbon atoms and 15
The following are organic groups. The carbon number of X is usually 2 or more, preferably 3 or more, more preferably 4
It is above, and is usually 14 or less, preferably 12 or less, more preferably 10 or less, and further preferably 8 or less.
In the general formula (5), X is particularly preferably an organic group having 4 to 15 carbon atoms and having at least one cycloalkylene group having 4 to 6 carbon atoms or an aromatic hydrocarbon group. At this time,
The hydrogen atom on the cycloalkylene group may be substituted with a methyl group or an ethyl group. Since the diisocyanate compound having a cyclic structure is a molecule because it is sterically bulky, side reactions are less likely to occur on the positive electrode, and as a result, cycle characteristics and high temperature storage characteristics are improved.
Here, the binding site of the group that binds to the cycloalkylene group or the aromatic hydrocarbon group is not particularly limited, and may be the meta position, the para position, or the ortho position, but the meta position or the para position is
It is preferable that the cross-linking distance between the coatings is appropriate, which is advantageous for lithium ion conductivity and easily lowers the resistance. Further, the cycloalkylene group is preferably a cyclopentylene group or a cyclohexylene group, from the viewpoint that the diisocyanate compound itself is less likely to cause a side reaction, and the cyclohexylene group is a resistance due to the influence of molecular mobility. It is more preferable because it can be easily lowered.

Further, 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 it has an alkylene group and becomes bulky in three dimensions, a side reaction on the positive electrode hardly occurs. 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 effects of the present invention are prominently exhibited.

The molecular weight of the diisocyanate compound represented by the general formula (5) is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. 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, the solubility of the diisocyanate compound in the non-aqueous electrolyte solution can be easily ensured and the effect of the present invention can be easily exhibited.

Specific examples of the diisocyanate compound 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'-diisocyanate, dicyclohexylmethane-3,3'-
Cycloalkane ring-containing diisocyanates such as 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(isocyanatomethyl)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-diisocyanate Aroma such as natonaphthalene, 2,3-diisocyanatonaphthalene, 1,5-bis(isocyanatomethyl)naphthalene, 1,8-bis(isocyanatomethyl)naphthalene, 2,3-bis(isocyanatomethyl)naphthalene Ring-containing diisocyanates;
And so on.

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 preferred because it forms a denser and more complex coating on the negative electrode, 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(isocyanatomethyl)benzene, 1,3
-Bis(isocyanatomethyl)benzene or 1,4-bis(isocyanatomethyl)benzene forms a film advantageous for lithium ion conductivity on the negative electrode due to the symmetry of its molecule, and as a result, battery characteristics are further improved. It is more preferable because it improves.

The above-mentioned diisocyanate compounds may be used alone or in any combination of two or more at any ratio.
In the non-aqueous electrolytic solution of the present invention, the content of the diisocyanate compound that can be used is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, with respect to the non-aqueous electrolytic solution of the present invention, Usually 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, further preferably 0.3 mass% or more, and usually 5 mass% or less, preferably 4 mass% Or less, more preferably 3 mass% or less, further preferably 2 mass%
It is as follows. 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 sufficiently exhibited.
The method for producing the diisocyanate compound is not particularly limited, and a known method can be arbitrarily selected and produced. Moreover, you may use a commercial item.

<2-3-5-2. Isocyanate compounds other than diisocyanate compounds>
The non-aqueous electrolyte solution of the present invention may contain an isocyanate compound other than the diisocyanate compound. Hereinafter, isocyanate compounds other than the diisocyanate compound that can be used in the non-aqueous electrolyte solution of the present invention will be described with reference to specific examples.
Specific examples of the isocyanate compound include, for example,
Hydrocarbon-based 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 a carbon-carbon unsaturated bond, such as vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, and propynyl isocyanate;
(Ortho-, meta-, para-)toluenesulfonyl isocyanate, benzenesulfonyl isocyanate, fluorosulfonyl isocyanate, phenoxysulfonyl isocyanate, pentafluorophenoxysulfonyl isocyanate, methoxysulfonyl isocyanate and other isocyanate compounds;
Etc.

The isocyanate compounds described above may be used alone or in any combination of two or more at any ratio.
There is no limitation on the content of the isocyanate compound in the whole non-aqueous electrolyte solution of the present invention, and it is arbitrary as long as the effect of the present invention is not significantly impaired. The content is usually 0.001% by mass or more, preferably 0.01% by mass or more, and more preferably 0.1% by mass based on the non-aqueous electrolyte solution of the present invention.
1 mass% or more, and usually 10 mass% or less, preferably 5 mass% or less, more preferably 3
The amount is not more than 2% by mass, more preferably not more than 2% by mass, particularly preferably not more than 1% by mass, most preferably not more than 0.5% by mass. 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 sufficiently exhibited.
The method for producing the isocyanate compound is not particularly limited, and a known method can be arbitrarily selected and produced. Moreover, you may use a commercial item.

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

In general formula (6), R ⁹ and R ¹⁰ each independently represent a hydrocarbon group having 1 to 15 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 or an aromatic hydrocarbon group, or may be a group in which an aliphatic hydrocarbon group and an aromatic hydrocarbon group are bonded. 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-shaped or cyclic, and in the case of chain-shaped, may be linear or branched. Further, it may be one in which a chain and a ring are combined. In addition, R ⁹ and R ¹⁰ may be the same as or different from each other.

Further, when R ⁹ and R ¹⁰ are bonded to each other to form a cyclic structure, the hydrocarbon group formed by bonding R ⁹ and R ¹⁰ to each other is divalent. The type of divalent hydrocarbon group is not particularly limited. That is, it may be an aliphatic group or an aromatic group, or may be 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. Further, it may be a chain group or a cyclic group, and in the case of a chain group, it may be a straight chain group or a branched chain group. Further, a chain group and a cyclic group may be bonded.

Further, when the hydrocarbon group of R ⁹ and R ¹⁰ has a substituent, the kind of the substituent is not particularly limited unless it is contrary to the gist of the present invention, but examples thereof include a fluorine atom, a chlorine atom and a bromine atom. And halogen atoms such as iodine atom, and preferably fluorine atom. Alternatively, examples of the substituent other than the gen atom include a substituent having a functional group such as an ester group, a cyano group, a carbonyl group and an ether group, and a cyano group and a carbonyl group are preferable. R
The hydrocarbon groups of ⁹ and R ¹⁰ may have only one of these substituents, or may have two or more thereof. When it has two or more substituents, those substituents may be the same or different from each other.

The number of carbon atoms of each of the hydrocarbon groups of R ⁹ and R ¹⁰ is usually 1 or more, and usually 15 or less, preferably 12 or less, more preferably 10 or less, still more preferably 9 or less. 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 13 or less. , More preferably 10 or less, still more preferably 8 or less. In addition, when the hydrocarbon group of R ⁹ and R ¹⁰ has a substituent containing a carbon atom, it is preferable that the total carbon number of 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, may be abbreviated as “acid anhydride”) will be described. In the following examples, the term "analog" refers to an acid anhydride obtained by substituting a part of the structure of the illustrated acid anhydride with another structure within the range not departing from the spirit of the present invention. A dimer, a trimer and a tetramer composed of a plurality of acid anhydrides, or a structural isomer such as a substituent having the same carbon number but having a branched chain, and the substituent being an acid. Examples thereof include those having different sites for binding to an anhydride.

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

Specific examples of the acid anhydride in which R ⁹ and R ¹⁰ are cyclic alkyl groups include cyclopropanecarboxylic acid anhydride, cyclopentanecarboxylic acid anhydride, cyclohexanecarboxylic acid anhydride, and the like, and analogs thereof. ..
Specific examples of the acid anhydride in which R ⁹ and R ¹⁰ are alkenyl groups include acrylic acid 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 acid anhydride, 2-methyl-3-methyl-3-butenoic acid anhydride, 2,2-dimethyl-
3-methyl-3-butenoic anhydride, 3-pentenoic anhydride, 4-pentenoic anhydride, 2-
Examples thereof include cyclopentenecarboxylic anhydride, 3-cyclopentenecarboxylic anhydride, 4-cyclopentenecarboxylic anhydride and the like, and analogs thereof.

Specific examples of the acid anhydride in which R ⁹ and R ¹⁰ are alkynyl groups include propynic anhydride,
3-Phenylpropynoic anhydride, 2-butyric acid anhydride, 2-pentynoic acid anhydride, 3-butyric acid anhydride, 3-pentynoic acid anhydride, 4-pentynoic acid anhydride, etc., and their analogs, etc. Is mentioned.
Specific examples of the acid anhydride in which R ⁹ and R ¹⁰ are aryl groups include benzoic anhydride and 4-
Methyl benzoic anhydride, 4-ethyl benzoic anhydride, 4-tert-butyl benzoic anhydride, 2-methyl benzoic anhydride, 2,4,6-trimethyl benzoic anhydride, 1-naphthalene carboxylic anhydride Compounds, 2-naphthalenecarboxylic acid anhydrides, and analogs thereof.

In addition, as examples of the acid anhydride in which R ⁹ and R ¹⁰ are substituted with a halogen atom, examples of an acid anhydride mainly substituted with a fluorine atom are given below, but some or all of these fluorine atoms are An acid anhydride obtained by substituting a chlorine atom, a bromine atom, or an iodine atom is also included in the exemplified compounds.
Examples of the acid anhydride in which R ⁹ and R ¹⁰ are chain alkyl groups substituted with a halogen atom 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-trifluoropropionic anhydride, perfluoropropionic anhydride, and the like, and those An analog etc. are mentioned.

Examples of the acid anhydride in which R ⁹ and R ¹⁰ are cyclic alkyl groups substituted with a halogen atom include 2-fluorocyclopentanecarboxylic acid anhydride, 3-fluorocyclopentanecarboxylic acid anhydride, and 4-fluorocyclopentane. Examples of the acid anhydride in which R ⁹ and R ¹⁰ are an alkenyl group substituted with a halogen atom, such as carboxylic acid anhydride and the like, and analogs thereof, include 2-fluoroacrylic acid anhydride and 3-fluoro Acrylic acid anhydride, 2,3-difluoroacrylic acid anhydride, 3,3-difluoroacrylic acid anhydride, 2,3,3-trifluoroacrylic acid anhydride, 2-(trifluoromethyl)acrylic acid anhydride, 3-(trifluoromethyl)acrylic anhydride, 2,3-bis(trifluoromethyl)acrylic anhydride, 2,
3,3-tris(trifluoromethyl)acrylic anhydride, 2-(4-fluorophenyl)acrylic anhydride, 3-(4-fluorophenyl)acrylic anhydride, 2,3-bis(
4-fluorophenyl)acrylic anhydride, 3,3-bis(4-fluorophenyl)acrylic anhydride, 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 acid anhydride, 3,3,4-trifluoro-3-butenoic acid anhydride and the like, and analogs thereof and the like can be mentioned.

Examples of the acid anhydride in which R ⁹ and R ¹⁰ are an alkynyl group substituted with a halogen atom include 3-fluoro-2-propynoic acid anhydride and 3-(4-fluorophenyl)-2-propynoic acid anhydride. , 3-(2,3,4,5,6-pentafluorophenyl)-2-propynoic acid anhydride, 4-fluoro-2-butyric acid anhydride, 4,4-difluoro-2-butyric acid anhydride, Four
, 4,4-trifluoro-2-butyric acid anhydride, and analogs thereof.

Examples of the acid anhydride in which R ⁹ and R ¹⁰ are aryl groups substituted with a halogen atom include:
4-fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, 4
-Trifluoromethyl benzoic anhydride and the like, and analogs thereof and the like.
Examples of the acid anhydrides in which R ⁹ and R ¹⁰ have a substituent having a functional group 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, etc., And analogs thereof and the like.

Next, specific examples of acid anhydrides in which R ⁹ and R ¹⁰ are different from each other are shown below.
R ⁹ and R ¹⁰ can be the above-listed examples and all combinations of their analogs, but representative examples are shown below.
Examples of combinations of chain alkyl groups include acetic acid propionic anhydride, acetic acid butanoic acid anhydride, butanoic acid propionic acid anhydride, acetic acid 2-methylpropionic acid anhydride,
And so on.

Examples of the combination of the chain alkyl group and the cyclic alkyl group include acetic acid cyclopentanoic acid anhydride, acetic acid cyclohexanoic acid anhydride, cyclopentanoic acid propionic acid anhydride, and the like.
Examples of the combination of the chain alkyl group and the alkenyl group include acetic acid acrylic anhydride, acetic acid 3-methylacrylic acid anhydride, acetic acid 3-butenoic acid anhydride, acrylic acid propionic acid anhydride, and the like.

Examples of the combination of the chain alkyl group and the alkynyl group include acetic acid propynoic anhydride, acetic acid 2-butyric acid anhydride, acetic acid 3-butyric acid anhydride, acetic acid 3-phenylpropynoic acid anhydride,
Propionic acid propynic anhydride, etc. are mentioned.
Examples of the combination of a chain alkyl group and an aryl group include acetic acid benzoic anhydride and acetic acid 4
-Methylbenzoic acid anhydride, acetic acid 1-naphthalenecarboxylic acid anhydride, benzoic acid propionic acid anhydride, and the like.

Examples of the combination of a chain alkyl group and a hydrocarbon group having a functional group include acetic acid fluoroacetic acid anhydride, acetic acid trifluoroacetic acid anhydride, acetic acid 4-fluorobenzoic acid anhydride, fluoroacetic acid propionic acid anhydride, and alkyl acetate. Examples thereof include oxalic anhydride, acetic acid 2-cyanoacetic anhydride, acetic acid 2-oxopropionic anhydride, acetic acid methoxyacetic anhydride, and methoxyacetic propionic anhydride.

Examples of combinations of cyclic alkyl groups include cyclopentanoic acid cyclohexanic anhydride.
Examples of the combination of cyclic alkyl group and alkenyl group include acrylic acid cyclopentanoic acid anhydride, 3-methylacrylic acid cyclopentanoic acid anhydride, 3-butenoic acid cyclopentanic acid anhydride, acrylic acid cyclohexanic acid anhydride, and the like. Are listed.

Examples of the combination of the cyclic alkyl group and the alkynyl group include propynoic acid cyclopentanoic acid anhydride, 2-butyric acid cyclopentanoic acid anhydride, propynoic acid cyclohexanoic acid anhydride,
And so on.
Examples of the combination of the cyclic alkyl group and the aryl group include benzoic acid cyclopentanoic acid anhydride, 4-methylbenzoic acid cyclopentanoic acid anhydride, benzoic acid cyclohexanoic acid anhydride,
And so on.

Examples of a combination of a cyclic alkyl group and a hydrocarbon group having a functional group include fluoroacetic acid cyclopentanoic acid anhydride, cyclopentanoic acid trifluoroacetic acid anhydride, cyclopentanoic acid 2-cyanoacetic acid anhydride, and cyclopentanoic acid methoxyacetic acid. Anhydrous, cyclohexanoic acid fluoroacetic acid anhydride, etc. may be mentioned.
Examples of the combination of alkenyl groups include acrylic acid 2-methylacrylic acid anhydride, acrylic acid 3-methylacrylic acid anhydride, acrylic acid 3-butenoic acid anhydride, 2-methylacrylic acid 3-methylacrylic acid anhydride. Things, etc.

Examples of the combination of the alkenyl group and the alkynyl group include acrylic acid propynoic acid anhydride, acrylic acid 2-butyric acid anhydride, and 2-methylacrylic acid propynic acid anhydride.
Examples of the combination of the alkenyl group and the aryl group include acrylic acid benzoic acid anhydride, acrylic acid 4-methylbenzoic acid anhydride, and 2-methylacrylic acid benzoic acid anhydride.

Examples of the combination of the alkenyl group and the hydrocarbon group having a functional group include acrylic acid fluoroacetic acid anhydride, acrylic acid trifluoroacetic acid anhydride, acrylic acid 2-cyanoacetic acid anhydride, acrylic acid methoxyacetic acid anhydride, 2- Methyl acrylic acid fluoroacetic anhydride, etc. are mentioned.
Examples of combinations of alkynyl groups include propynoic acid 2-butyric acid anhydride, propynoic acid 3-butyric acid anhydride, 2-butyric acid 3-butyric acid anhydride, and the like.

Examples of the combination of an alkynyl group and an aryl group include benzoic acid propynoic anhydride, 4
-Methylbenzoic acid propynic anhydride, benzoic acid 2-butyric anhydride, and the like.
Examples of the combination of an alkynyl group and a hydrocarbon group having a functional group include propynoic acid fluoroacetic anhydride, propynoic acid trifluoroacetic acid anhydride, propynoic acid 2-cyanoacetic acid anhydride, propynoic acid methoxyacetic acid anhydride, 2- Butyric acid fluoroacetic anhydride, and the like.

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

Examples of combinations of hydrocarbon groups having functional groups include fluoroacetic acid trifluoroacetic acid anhydride, fluoroacetic acid 2-cyanoacetic acid anhydride, fluoroacetic acid methoxyacetic acid anhydride, trifluoroacetic acid 2-cyanoacetic acid anhydride, and the like. Are listed.
Of the acid anhydrides forming the above chain structure, preferably,
Acetic anhydride, propionic anhydride, 2-methylpropionic anhydride, cyclopentanecarboxylic anhydride, cyclohexanecarboxylic anhydride, etc., acrylic anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride , 2,3-dimethylacrylic anhydride, 3,
3-dimethylacrylic anhydride, 3-butenoic anhydride, 2-methyl-3-butenoic anhydride, propynic anhydride, 2-butyric 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,
Ethoxy formic anhydride,
And more preferably,
Acrylic anhydride, 2-methylacrylic anhydride, 3-methylacrylic anhydride, benzoic anhydride, 2-methylbenzoic anhydride, 4-methylbenzoic anhydride, 4-tert-butylbenzoic anhydride Compounds, 4-fluorobenzoic anhydride, 2,3,4,5,6-pentafluorobenzoic anhydride, methoxyformic anhydride, and ethoxyformic anhydride.

These compounds can improve the charge/discharge rate characteristics, the input/output characteristics, and the impedance characteristics especially after the durability test by forming a film with excellent durability by appropriately forming a bond with the lithium oxalate salt. It is preferable from the viewpoint of being able to.
Next, specific examples of the acid anhydride in which R ⁹ and R ¹⁰ are bonded to each other to form a cyclic structure are shown below.

First, specific examples of the acid anhydride in which R ⁹ and R ¹⁰ are bonded to each other to form a 5-membered ring structure include succinic anhydride, 4-methylsuccinic anhydride, and 4,4-dimethylsuccinic anhydride. Stuff,
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-diphenyl maleic anhydride, itaconic anhydride, 5-methyl itaconic anhydride, 5
5,5-dimethylitaconic anhydride, phthalic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, and the like, and analogs thereof.

Specific examples of the acid anhydride in which R ⁹ and R ¹⁰ are bonded to each other to form a 6-membered ring structure include cyclohexane-1,2-dicarboxylic acid anhydride and 4-cyclohexene-1,2-dicarboxylic acid. An anhydride, glutaric anhydride, etc., and those analogs etc. are mentioned.
Specific examples of the acid anhydride in which R ⁹ and R ¹⁰ are bonded to each other to form another cyclic structure include 5-norbornene-2,3-dicarboxylic acid anhydride and cyclopentanetetracarboxylic acid dianhydride. , Pyromellitic dianhydride, diglycolic anhydride, and their analogs.

Specific examples of the acid anhydride in which R ⁹ and R ¹⁰ are bonded to each other to form a cyclic structure and which is 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 -Difluoro maleic anhydride, 5-fluoro itaconic anhydride, 5,5-difluoro itaconic anhydride and the like, and analogs thereof and the like.

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 acid Acid anhydride, cyclopentanetetracarboxylic 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, cyclopentanetetra Carboxylic dianhydride, pyromellitic dianhydride,
It is 4-fluorosuccinic anhydride. These compounds are preferable because they form a bond with a lithium oxalate salt appropriately to form a coating film having excellent durability, and in particular, the capacity retention rate after a durability test is improved.

The molecular weight of the carboxylic acid anhydride is not limited, and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 90 or more, preferably 95 or more, while it is usually 300 or less, preferably 200 or less. .. When the molecular weight of the carboxylic acid anhydride is within the above range, the viscosity increase of the electrolytic solution can be suppressed, and the coating density is optimized, so that the durability can be appropriately improved.

The method for producing the carboxylic acid anhydride is not particularly limited, and a known method can be arbitrarily selected and produced. Any one of the carboxylic acid anhydrides described above may be contained alone in the non-aqueous electrolyte solution of the present invention, or two or more thereof may be combined in any combination and ratio.
Further, the content of the carboxylic acid anhydride in the non-aqueous electrolyte solution of the present invention is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but it is usually 0 for the non-aqueous electrolyte solution of the present invention. It is desirable that the content be 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 battery characteristics are likely to be improved since the reactivity is suitable.

<2-3-7. Overcharge prevention agent>
In the non-aqueous electrolyte solution of the present invention, an overcharge inhibitor can be used in order to effectively suppress the rupture and ignition of the battery when the non-aqueous electrolyte secondary battery is in a state of overcharge or the like. ..
Examples of the overcharge preventing agent 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; Partial fluorinated compounds of the above aromatic compounds such as 2-fluorobiphenyl, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene; 2,4-difluoroanisole, 2,5-difluoro Anisole, 2
, 6-difluoroanisole, 3,5-difluoroanisole and other fluorine-containing anisole compounds; aromatics such as 3-propylphenylacetate, 2-ethylphenylacetate, benzylphenylacetate, methylphenylacetate, benzylacetate and phenethylphenylacetate Acetates; aromatic carbonates such as diphenyl carbonate and methylphenyl carbonate. Among them, biphenyl, alkylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenylether, 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 alone or in combination of two or more. When two or more are used in combination, especially cyclohexylbenzene and t-
A combination with butylbenzene or t-amylbenzene, biphenyl, alkylbiphenyl, terphenyl, partially hydrogenated terphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, and other oxygen-free aromatic compounds. It is preferable to use at least one selected from the group consisting of oxygen-containing aromatic compounds such as diphenyl ether and dibenzofuran together from the viewpoint of the balance between overcharge prevention properties and high-temperature storage properties.

The content of the overcharge inhibitor is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired. 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, further preferably 0% in 100% by mass of the non-aqueous electrolyte solution.
． It is 5% by mass or more, and usually 5% by mass or less, preferably 4.8% by mass or less, and more preferably 4.5% by mass or less. Within this range, the effect of the overcharge inhibitor can be sufficiently exhibited, and the battery characteristics such as high temperature storage characteristics are improved.

<2-3-8. Other auxiliaries>
Other known auxiliary agents can be used in the non-aqueous electrolyte 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-diethane sulfonate, 2-butyne-1,4-diyl-diformate, 2-
Butyne-1,4-diyl-diacetate, 2-butyne-1,4-diyl-dipropionate, 4-hexadiyne-1,6-diyl-dimethanesulfonate, 2-propynyl-methanesulfonate, 1-methyl-2- Propinyl-methanesulfonate, 1,1-dimethyl-2-propynyl-methanesulfonate, 2-propynyl-ethanesulfonate, 2-propynyl-vinylsulfonate, 2-propynyl-2-(diethoxyphosphoryl)acetate, 1-methyl-2 -Propynyl-2-(diethoxyphosphoryl)acetate, 1,1
A triple bond-containing compound such as dimethyl-2-propynyl-2-(diethoxyphosphoryl)acetate;

2,4,8,10-Tetraoxaspiro[5.5]undecane, 3,9-divinyl-2
, 4,8,10-Tetraoxaspiro[5.5]undecane and other spiro compounds;
Ethylene sulfite, methyl fluorosulfonate, ethyl fluorosulfonate, methyl methanesulfonate, ethyl methanesulfonate, busulfan, sulfolene, diphenyl sulfone, N,N-dimethylmethanesulfonamide, N,N-diethylmethanesulfonamide, methyl Sulfur-containing compounds such as trimethylsilyl sulfate, trimethylsilyl ethyl sulfate, and 2-propynyl-trimethylsilyl sulfate;

2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate, 2-
Isocyanatoethyl crotonate, 2-(2-isocyanatoethoxy)ethyl acrylate, 2-(2-isocyanatoethoxy)ethyl methacrylate, 2-(2-isocyanatoethoxy)ethyl crotonate, and other isocyanate compounds;
Nitrogen-containing compounds such as 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone and N-methylsuccinimide;

Hydrocarbon compounds such as heptane, octane, nonane, decane, cycloheptane;
Fluorine-containing aromatic compounds such as fluorobenzene, difluorobenzene, hexafluorobenzene, benzotrifluoride, pentafluorophenyl methanesulfonate, pentafluorophenyl trifluoromethane sulfonate, pentafluorophenyl acetate, pentafluorophenyl trifluoroacetate, and methyl pentafluorophenyl carbonate Compound;
Tris(trimethylsilyl)borate, tris(trimethoxysilyl)borate, tris(trimethylsilyl)phosphate, tris(trimethoxysilyl)phosphate, dimethoxyaluminoxytrimethoxysilane, diethoxyaluminoxytriethoxysilane, dipropoxyalumino Xytriethoxysilane, dibutoxyaluminoxytrimethoxysilane, dibutoxyaluminoxytriethoxysilane, titanium tetrakis (trimethylsiloxide), titanium tetrakis (triethylsiloxide),
Silane compounds such as;

2-propanyl 2-(methanesulfonyloxy)propionate, 2-methyl 2-(methanesulfonyloxy)propionate, 2-(methanesulfonyloxy)propionic acid 2-
Ethyl, methanesulfonyloxyacetic acid 2-propynyl, methanesulfonyloxyacetic acid 2-
Ester compounds such as methyl and 2-ethyl methanesulfonyloxyacetate;
Lithium ethylmethyloxycarbonylphosphonate, lithium ethylethyloxycarbonylphosphonate, lithium ethyl-2-propynyloxycarbonylphosphonate, lithium ethyl-1-methyl-2-propynyloxycarbonylphosphonate, lithium ethyl-1,1-dimethyl-2-propynyl Lithium salt such as oxycarbonylphosphonate;
Etc. These may be used alone or in combination of two or more. By adding these auxiliary agents, it is possible to improve the capacity retention characteristics and the cycle characteristics after high temperature storage.

The content of other auxiliaries is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. 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 electrolyte, and usually It is 5 mass% or less, preferably 3 mass% or less, and more preferably 1 mass% or less. Within this range, the effects of other auxiliaries are likely to be sufficiently exhibited, and the battery characteristics such as high load discharge characteristics are improved.

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

<2-4. Manufacturing method of non-aqueous electrolyte>
The non-aqueous electrolyte solution of the present invention is prepared by dissolving the electrolyte, the compound represented by the structural formula of P(OR) ₅ and the above-mentioned “auxiliary agent” in the above-mentioned non-aqueous solvent, if necessary. can do.
When preparing the non-aqueous electrolytic solution, the respective raw materials of the non-aqueous electrolytic solution, that is, the electrolyte such as a lithium salt, the compound represented by the structural formula of P(OR) ₅ , the non-aqueous solvent, the auxiliary agent, etc. are dehydrated in advance. Preferably. The degree of dehydration is usually 50 ppm or less, preferably 30 ppm
It is desirable to dehydrate until the following.

By removing the water in the non-aqueous electrolyte, the electrolysis of water, the reaction of water and lithium metal,
The lithium salt is less likely to be hydrolyzed. 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 molecular sieve may be used. When 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 occluding 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, the primary battery or the secondary battery is preferable, and the secondary battery is particularly preferable. The non-aqueous electrolyte solution used in these energy devices is also preferably a so-called gel electrolyte that is pseudo-solidified with a polymer, a filler, or the like. Hereinafter, the energy device will be described.

<3-1. Non-aqueous electrolyte secondary battery>
<3-1-1. Battery configuration>
The non-aqueous electrolyte secondary battery according to one embodiment of the present invention (hereinafter, also referred to as the non-aqueous secondary battery of the present invention) has a configuration other than the non-aqueous electrolyte, and is a conventionally known non-aqueous electrolyte secondary battery. It is similar to the secondary battery, and usually has a form in which a positive electrode and a negative electrode are laminated via a porous film (separator) impregnated with the non-aqueous electrolyte 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 any of a cylindrical type, a square type, a laminate type, a coin type, a large size and the like.

<3-1-2. Non-aqueous electrolyte>
As the non-aqueous electrolytic solution, the above-mentioned non-aqueous electrolytic solution of the present invention is used. In addition, it is also possible to mix and use other non-aqueous electrolyte solution with the non-aqueous electrolyte solution of the present invention without departing from the scope 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 store and release metal ions. Specific examples thereof include carbonaceous materials, metal compound-based materials, lithium-containing metal composite oxide materials and the like. These 1 type may be used individually and may be used in combination of 2 or more types arbitrarily.
Of these, carbonaceous materials and metal compound-based materials are preferable. Among metallic compound materials,
A material containing silicon is preferable, and therefore a carbonaceous material and a material containing silicon are particularly preferable 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 the following (a) to
Those selected from (d) are preferable because they give a secondary battery having a good balance of initial irreversible capacity and high current density charge/discharge characteristics.
(A) Natural graphite (b) Carbonaceous material obtained by heat-treating an artificial carbonaceous material and an artificial graphiteous material at least once in the range of 400° C. to 3200° C. (c) At least two types of negative electrode active material layers Composed of carbonaceous materials with different crystallinity,
And/or a carbonaceous material having an interface in which different crystalline carbonaceous materials are in contact. (d) The negative electrode active material layer is composed of at least two types of carbonaceous materials having different orientations,
And/or the carbonaceous material having an interface in which carbonaceous materials of different orientations are in contact (a) to (d), the carbonaceous materials may be used alone or in any combination of two or more. And ratios may be used together.

Specific examples of the artificial carbonaceous material or the artificial graphite material in (a) above include natural graphite,
Coal-based coke, petroleum-based coke, coal-based pitch, petroleum-based pitch, and those obtained by oxidizing these pitches;
Needle coke, pitch coke and carbon materials obtained by partially graphitizing these;
Furnace black, acetylene black, thermal decomposition products of organic substances such as pitch-based carbon fiber;
Carbonizable organics and their carbides; and
Examples include solution-form carbides obtained by dissolving a carbonizable organic substance in a low-molecular organic solvent such as benzene, toluene, xylene, quinoline, and n-hexane.
In addition, all of the above-mentioned carbonaceous materials (a) to (d) are conventionally known, their manufacturing methods are well known to those skilled in the art, and these commercial products can be purchased.

<3-1-3-2. Metal compound materials>
The metal compound-based material used as the negative electrode active material is not particularly limited as long as it can store and release lithium, and a single metal or an alloy forming an alloy with lithium, or an oxide, a carbide, or a nitride thereof, Compounds such as silicide, sulfide and phosphide can be used. Such metal compounds include Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P,
Examples thereof include compounds containing metals such as Pb, Sb, Si, Sn, Sr, and Zn. Among them, a simple metal or an alloy forming an alloy with lithium is preferable, and a metal/metalloid element of the periodic table group 13 or group 14 (that is, excluding carbon. Also, hereinafter, the metal and the semimetal are collectively referred to as “ It is more preferable that the material includes a metal (referred to as “metal”), and further, silicon (S
i), a simple metal of tin (Sn) or lead (Pb) (hereinafter, these three kinds of elements may be referred to as “SSP metal element”) or an alloy containing these atoms, or a metal thereof (SSP)
The compound is preferably a metal element). Particularly preferred are compounds containing silicon. These may be used alone or in any combination of two or more at any 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 lithium-titanium composite oxide is preferable. Thing (hereinafter, "lithium titanium composite oxide"
May be abbreviated. ) Is particularly preferable. That is, it is particularly preferable to use 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, lithium or titanium of the lithium-titanium composite oxide may be mixed with other metal elements such as Na.
Also preferred are those substituted with at least one element selected from the group consisting of K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and Nb.
Examples of the lithium-titanium composite oxide preferable as the negative electrode active material include the lithium-titanium composite oxide represented by the following general formula (7).

Li _x Ti _y M _z O ₄ (7)
(In the general formula (7), M is Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu.
, At least one element selected from the group consisting of Zn and Nb. In addition, the general formula (7
), 0.7≦x≦1.5, 1.5≦y≦2.3, and 0≦z≦1.6, the structure is stable when doping/dedoping lithium ions. Therefore, it is preferable. )

<2-1-3-4. Configuration, physical properties, preparation method of negative electrode>
Regarding the negative electrode containing the active material, the electrode forming method, and the current collector, known technical configurations can be adopted, and any one or more of the following items (i) to (vi) can be used. It is desirable to satisfy both at the same time.

(I) Production of Negative Electrode Any known method can be used for producing the negative electrode, unless the effect of the present invention is significantly limited. For example, a negative electrode active material is added with a binder, a solvent, and if necessary, a thickener, a conductive material, a filler, etc. to form a slurry-like negative electrode forming material, which is applied to a current collector, dried, and then pressed. Thus, the negative electrode active material layer can be formed.

(Ii) Current collector As the current collector for holding the negative electrode active material, any known current collector can be used. Examples of the current collector for the negative electrode include metal materials such as aluminum, copper, nickel, stainless steel, and nickel-plated steel, but copper is particularly preferable from the viewpoint of workability and cost.
When the current collector is made of a metal material, examples of the shape of the current collector include a metal foil, a metal column, a metal coil, a metal plate, a metal thin film, an expanded metal, a punch metal, and a foam metal. Among them, a metal thin film is preferable, a copper foil is more preferable, and a rolled copper foil by a rolling method and an electrolytic copper foil by an electrolytic method are more preferable.

(Iii) Thickness Ratio of Current Collector and Negative Electrode Active Material Layer Although the thickness ratio of the current collector and the negative electrode active material layer is not particularly limited, “(one surface immediately before the step of injecting the non-aqueous electrolyte solution) Value of negative electrode active material layer)/(thickness of current collector) is preferably 150 or less, more preferably 20 or less, particularly preferably 10 or less, and preferably 0.1 or more,
0.4 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 charge/discharge of the secondary battery. Also, if below the above range,
The volume ratio of the current collector to the negative electrode active material may increase, 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 existing on the current collector is preferably 1 g·cm ⁻³ or more, and 1 .2g · ^{cm -3} or more preferably, 1.3 g · ^{cm -3} or more, and also preferably 4g · ^{cm -3} or less, more preferably 3 g · ^{cm -3} or less, 2.5 g · cm ^{- 3} or less is more preferable, 1.7
It is particularly preferably g·cm ⁻³ or less. If 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, and the initial irreversible capacity of the secondary battery is increased,
It becomes easy to prevent deterioration of high current density charge/discharge characteristics due to a decrease in the permeability of the non-aqueous electrolyte solution near the interface between the current collector/negative electrode active material. Furthermore, the conductivity between the negative electrode active materials can be secured, and the capacity per unit volume can be earned without increasing the battery resistance.

(V) Binder, Solvent, etc. A 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. It
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 electrolyte solution and the solvent used during electrode production.

Specific examples thereof include polyethylene, polypropylene, polyethylene terephthalate,
Resin-based polymers such as polymethylmethacrylate, aromatic polyamide, cellulose, 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 hydrogenated product thereof;
EPDM (ethylene/propylene/diene terpolymer), styrene/ethylene/butadiene/styrene copolymer, styrene/isoprene/styrene block copolymer or a thermoplastic elastomeric polymer such as hydrogenated product thereof;
Soft resinous polymers such as syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene/vinyl acetate copolymers, propylene/α-olefin copolymers;
Fluorine-based polymers such as polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene fluoride, and polytetrafluoroethylene/ethylene copolymers;
Examples thereof include polymer compositions having ion conductivity of alkali metal ions (particularly lithium ions). These may be used alone or in any combination of two or more at any ratio.

The solvent for forming the slurry is not particularly limited in its type as long as it is a solvent that can dissolve or disperse the negative electrode active material, the binder, and the thickener and the conductive material used as necessary. Alternatively, 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, diethyl triamine. , N,N-dimethylaminopropylamine, tetrahydrofuran (THF), toluene, acetone, diethyl ether, dimethylacetamide, hexamethylphosphamide, dimethylsulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, hexane, etc. Can be mentioned.

In particular, when an aqueous solvent is used, it is preferable to add a dispersant or the like in addition to the thickener and form a slurry using a latex such as SBR.
These solvents may be used alone or in any combination of two or more at any ratio.
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,
0.5 mass part or more is more preferable, 0.6 mass part or more is still more preferable, 20 mass part or less is preferable, 15 mass part or less is more preferable, 10 mass part or less is further preferable, 8 mass part or less is Particularly preferred. 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, so that the battery capacity is less likely to decrease. Furthermore, the strength of the negative electrode is less likely to decrease.

In particular, when the slurry as 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 0.5 parts by mass or more is more preferable, 0.6 parts by mass or more is further preferable, 5 parts by mass or less is preferable, 3 parts by mass or less is more preferable, and 2 parts by mass or less is further preferable.
Further, when the slurry contains a fluorine-based polymer typified 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 further preferably 8 parts by mass or less.

Thickeners are commonly used to adjust the viscosity of slurries. The thickener is not particularly limited, and specific examples thereof include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and salts thereof. Even if these are used alone,
You 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 part by mass or more, preferably 0.5 part by mass or more, and more preferably 0.6 part by mass or more. The ratio is usually 5 parts by mass or less, preferably 3 parts by mass or less, and 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 coatability becomes good. Further, the ratio of the negative electrode active material in the negative electrode active material layer becomes appropriate, and the problem of decreasing the battery capacity and the problem of increasing the resistance between the negative electrode active materials are 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 facing positive electrode plate so that the positive electrode plate does not protrude from the negative electrode plate. Also, 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 preferable to make the area as close as possible to the positive electrode as much as possible because the ratio of the electrodes working more uniformly and effectively is increased and the characteristics are improved. In particular, when the secondary battery is used with a large current, the design of the area of this 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 will be 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 can occlude and release metal ions electrochemically. For example, a material that can occlude and release lithium ions electrochemically is preferable.
A substance containing lithium and at least one transition metal is preferred. Specific examples include a lithium-transition metal composite oxide, a lithium-containing transition metal phosphate compound, a lithium-containing transition metal silicate compound, and a lithium-containing transition metal boric acid compound.

The transition metal of the lithium-transition metal composite oxide is V, Ti, Cr, Mn, Fe, C.
O, Ni, Cu and the like are preferable, and specific examples of the composite oxide include lithium-cobalt composite oxide such as LiCoO ₂ , lithium-nickel composite oxide such as LiNiO ₂ , LiMn.
Lithium-manganese composite oxides such as O ₂ , LiMn ₂ O ₄ , and Li ₂ MnO ₄ , and some of the transition metal atoms that are the main constituents of these lithium-transition metal composite oxides are Al, Ti, V, Cr, M.
n, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn
, W, and the like substituted with other metals.

Specific examples of the substituted ones include, for example, LiNi _0.5 Mn _0.5 O ₂ and 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.
Above all, a composite oxide containing lithium, nickel and cobalt is more preferable. This is because the complex oxide containing cobalt and nickel can have a large capacity when used at the same potential.

On the other hand, cobalt is an expensive metal with a small amount of resources, and the large amount of active material used in large-sized batteries such as automobiles that require high capacity makes it a cheaper transition metal in terms of cost. 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, from the viewpoint of highly satisfying the balance between cost and capacity, 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. For example, LiNi _0.
5 Co _0.2 Mn _0.3 O ₂ or LiNi _0.6 Co _0.2 Mn _0.2 O ₂ or LiNi _0.
8 Co _0.1 Mn _0.1 O _{2 and the} like are mentioned as particularly preferable specific examples.

Further, in view of stability as a compound and procurement cost due to easiness of production, a lithium manganese composite oxide having a spinel structure is also preferable. That is, LiMn ₂ O ₄ , LiMn _1.8 Al _0.2 O ₄ , Li _1.1 Mn _1.9 Al _0.1 O ₄ among the above specific examples.
, LiMn _1.5 Ni _0.5 O _{4 and the} like can also be mentioned as preferable specific examples.
Examples of the transition metal of the lithium-containing transition metal phosphate compound include V, Ti, Cr, Mn, and F.
e, Co, Ni, Cu and the like are preferable, and specific examples of the phosphoric acid compound include LiF.
Iron phosphates such as ePO ₄ , Li ₃ Fe ₂ (PO ₄ ) ₃ , and LiFeP ₂ O ₇ , LiCoPO ₄
Such as cobalt phosphates such as LiMnPO ₄ , manganese phosphates such as LiMnPO ₄ , and some of the transition metal atoms that are the main constituents of these lithium transition metal phosphate compounds are Al, Ti, V, Cr, Mn, Fe, Co,
Examples thereof include those substituted with other metals such as Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn and W.

As the transition metal of the lithium-containing transition metal silicate compound, V, Ti, Cr, Mn,
Fe, Co, Ni, Cu and the like are preferable, and specific examples of the silicic acid compound include L
Iron silicates such as i ₂ FeSiO _4, cobalt silicates such as Li ₂ CoSiO ₄ , and some 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, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo,
Examples thereof include those substituted with other metals such as Sn and W.

As the transition metal of the lithium-containing transition metal boric acid compound, V, Ti, Cr, Mn,
Fe, Co, Ni, Cu and the like are preferable, and specific examples of the boric acid compound include, for example, L.
Iron borate such as iFeBO _3, cobalt borate such as LiCoBO ₃ , and some of the transition metal atoms that are the main constituents of these lithium transition metal borate compounds are Al, Ti, V, Cr, Mn,
Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W
Those substituted with other metals such as

(2) Manufacturing Method of Positive Electrode Active Material The manufacturing method of the positive electrode active material is not particularly limited as long as it does not exceed the scope of the present invention.
There are several methods, and a general method is used as a method for producing an inorganic compound.
In particular, various methods are conceivable for producing a spherical or elliptic spherical active material. For example, transition metal raw materials such as transition metal nitrates and sulfates, and raw materials of other elements as necessary are used. It is dissolved or pulverized and dispersed in a solvent such as water, and the pH is adjusted while stirring to prepare and recover a spherical precursor, which is dried if necessary, and then LiOH, Li ₂ CO ₃ , Li
A method of adding an Li source such as NO ₃ and firing at a high temperature to obtain an active material can be mentioned.

Further, as another example of the 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. do it,
It is dried and molded with a spray dryer to give a spherical or ellipsoidal precursor, and L
Examples include a method of adding an Li source such as iOH, Li ₂ CO ₃ , and LiNO ₃ and firing at a high temperature to obtain an active material.

As still another example of the method, transition metal raw materials such as transition metal nitrates, sulfates, hydroxides, and oxides, a Li source such as LiOH, Li ₂ CO ₃ , and LiNO ₃ , and other elements as necessary. The raw material of is dissolved or pulverized and dispersed in a solvent such as water, and is dried and molded by a spray dryer or the like to give a spherical or elliptic spherical precursor, which is fired at a high temperature to obtain an active material. Can be mentioned.

<3-1-4-2. Positive electrode structure and fabrication method>
The constitution of the positive electrode used in the present invention and the method for producing the same will be described below.
(Method for producing positive electrode)
The positive electrode is manufactured by forming a positive electrode active material layer containing positive electrode active material particles and a binder on a current collector. The positive electrode using the positive electrode active material can be manufactured by any known method. For example, a positive electrode active material and a binder, and optionally a conductive material and a thickener, etc. are dry mixed to form a sheet, which is then pressure-bonded to the 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 coating the positive electrode current collector with the thus-dispersed slurry 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, further preferably 80% by mass or more, and preferably 99.9% by mass or less. And 99% by mass or less is more preferable. When the content of the positive electrode active material is within the above range, sufficient electric capacity can be secured. Further, the strength of the positive electrode will be sufficient. The positive electrode active material powder in the present invention may be used alone, or two or more kinds having different compositions or different powder properties may be used in any combination and ratio. When using two or more kinds of active materials 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 a large battery that requires a high capacity such as an automobile is large. Therefore, it is desirable to use manganese as a main component as a cheaper transition metal.

(Conductive material)
Any known conductive material can be used as the conductive material. Specific examples thereof 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 be used together by 2 or more types in 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, further preferably 1% by mass or more, and preferably 50% by mass or less. And 30% by mass or less is more preferable, and 15% by mass or less is further preferable. When the content is within the above range, sufficient conductivity can be secured. 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 stable to the non-aqueous electrolyte solution and the solvent used for manufacturing the electrode.
When the positive electrode is produced by the coating method, the binder is not particularly limited as long as it is a material that is dissolved or dispersed in the liquid medium used in the production of the electrode, and specific examples thereof include polyethylene, polypropylene, polyethylene terephthalate and polymethyl. Resin-based polymers such as methacrylate, aromatic polyamide, cellulose, nitrocellulose;

SBR (styrene-butadiene rubber), NBR (acrylonitrile-butadiene rubber)
, Fluororubber, isoprene rubber, butadiene rubber, ethylene-propylene rubber and other rubber-like polymers;
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 hydrogenated products thereof;

Soft resinous polymers such as syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene/vinyl acetate copolymers, propylene/α-olefin copolymers;
Fluorine-based polymers such as polyvinylidene fluoride (PVdF), polytetrafluoroethylene, fluorinated polyvinylidene fluoride and polytetrafluoroethylene/ethylene copolymers;
Examples thereof include polymer compositions having ion conductivity of alkali metal ions (particularly lithium ions). These substances may be used alone or in any combination of two or more at any ratio.

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, further preferably 3% by mass or more, and preferably 80% by mass or less, 60 mass% or less is more preferable, 40 mass% or less is further preferable, and 10 mass% or less is particularly preferable. When the proportion 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 secured, so that the battery performance such as cycle characteristics becomes good. Furthermore, it also leads to avoiding a decrease in battery capacity and conductivity.

(Liquid medium)
The liquid medium used in the preparation of the slurry for forming the positive electrode active material layer is a positive electrode active material, a conductive material, a binder, and a solvent capable of dissolving or dispersing the thickener used as necessary. If there is no particular limitation on the type, 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 hexamethylphosphamide, dimethylsulfoxide and the like can be mentioned. In addition, these may be used individually by 1 type and may be used together by 2 or more types in arbitrary combinations and ratios.

(Thickener)
When an aqueous medium is used as the liquid medium for forming the slurry, it is preferable to make it into a slurry using a thickener and a latex such as styrene-butadiene rubber (SBR). Thickeners are commonly used to adjust the viscosity of slurries.
The thickener is not limited as long as the effect of the present invention is not significantly limited, but specifically, carboxymethylcellulose, methylcellulose, hydroxymethylcellulose, ethylcellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and salts thereof. Etc. These may be used alone or in any combination of two or more at any ratio.

When using a thickener, the ratio of the thickener to the total mass of the positive electrode active material and the thickener is preferably 0.1 mass% or more, more preferably 0.5 mass% or more, 0.6 mass%
The above is more preferable, it is preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 2% by mass or less. Within the above range, the coating property of the slurry will be good, and further, the ratio of the active material in the positive electrode active material layer will be sufficient, so that the problem of decreasing the capacity of the secondary battery and the positive electrode active material It becomes easier to avoid the problem of increased resistance.

(Consolidation)
The positive electrode active material layer obtained by applying and drying the slurry on the current collector is preferably compacted by a hand press, a roller press 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} more preferably less, 3.8 g · ^{cm -3} or less are particularly preferred.
When the density of the positive electrode active material layer is within the above range, the permeability of the non-aqueous electrolyte solution to the vicinity of the current collector/active material interface does not decrease, and the charge and discharge of the secondary battery at a high current density is achieved. The characteristics are good. 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; carbonaceous materials such as carbon cloth and carbon paper. Of these, metal materials, particularly aluminum are preferable.

Examples of the shape of the current collector include a metal foil, a metal cylinder, a metal coil, a metal plate, a metal thin film, an expanded metal, a punch metal, and a foam metal in the case of a metal material, and a carbon plate in the case of a carbonaceous material, Examples thereof include a carbon thin film and a carbon column. Of these, metal thin films are preferred.
The thin film may be appropriately formed in a mesh shape.
The thickness of the current collector is arbitrary, but is preferably 1 μm or more, more preferably 3 μm or more, further preferably 5 μm or more, and further preferably 1 mm or less, 100 μm or less, more 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 secured. In addition, the handleability is also good.

The ratio of the thickness of the current collector and the thickness of the positive electrode active material layer is not particularly limited, but (the thickness of the active material layer on one surface immediately before the nonaqueous electrolytic solution injection)/(the thickness of the 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 ratio of the thickness of the current collector to the thickness of the positive electrode active material layer is within the above range, it becomes difficult for the current collector to generate heat due to Joule heat during high current density charge/discharge of the secondary battery. Furthermore, it becomes difficult for the volume ratio of the current collector to the positive electrode active material to increase, and it is possible to prevent a decrease in battery capacity.

(Electrode area)
From the viewpoint of increasing the output and stability at high temperature, 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 area of the electrode area of the positive electrode with respect to the surface area of the exterior of the non-aqueous electrolyte secondary battery is preferably 20 times or more, more preferably 40 times or more in terms of area ratio. The outer surface area of the outer case, in the case of a rectangular shape with a bottom, refers to the total area obtained by calculation from the length, width, and thickness dimensions of the case part filled with the power generation element excluding the protruding parts of the terminals. .. In the case of a bottomed cylindrical shape, it is a geometric surface area that approximates the case portion filled with the power generation element excluding the protruding 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, and in the structure in which the positive electrode mixture layer is formed on both sides with the collector foil interposed therebetween. , The sum of the areas calculated for each surface separately.

(Discharge capacity)
When the non-aqueous electrolyte solution of the present invention is used, the electric capacity of the battery element housed in one battery exterior of the non-aqueous electrolyte secondary battery (electric capacity when the battery is discharged from a fully charged state to a discharged state) ) Is 1 ampere hour (Ah) or more, the effect of improving low-temperature discharge characteristics becomes large, which is preferable. Therefore, the positive electrode plate has a discharge capacity of fully charged, preferably 3 Ah (ampere hour), more preferably 4 Ah or more, and preferably 20 Ah or less,
More preferably, it is designed to be 10 Ah or less.

Within the above range, the voltage drop due to the electrode reaction resistance does not become too large when a large current is taken out, and the deterioration of the power efficiency can be prevented. Furthermore, the temperature distribution due to the internal heat generation of the battery during pulse charging/discharging does not become too large, the durability of repeated charging/discharging is poor, and the heat dissipation efficiency is also poor against sudden heat generation during abnormal conditions such as overcharging and internal short circuits. It is possible to avoid such a phenomenon.

(Thickness of positive 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 from which the thickness of the current collector is subtracted is preferably 10 μm or more, more preferably 20 μm or more, and preferably 200 μm or less and 150 μm with respect to one surface of the current collector.
It is more preferably m 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 to prevent a short circuit. In this case, the non-aqueous electrolytic solution of the present invention is usually used by impregnating this separator.
There is no particular limitation on the material and shape of the separator, and any known material may be used as long as the effects of the present invention are not significantly impaired. Among them, formed of a material stable to the non-aqueous electrolyte of the present invention, a resin, glass fiber, an inorganic substance or the like is used, and a porous sheet or a non-woven fabric-like substance excellent in liquid retention is used. Is preferred.

As the material of the resin and the glass fiber separator, for example, polyolefin such as polyethylene and polypropylene, aramid resin, polytetrafluoroethylene, polyether sulfone, glass filter and the like can be used. Of these, glass filters and polyolefins are preferable, and polyolefins are more preferable. These materials may be used alone or in any combination of two or more in any ratio.

The thickness of the separator is arbitrary, but is preferably 1 μm or more, more preferably 5 μm or more, further preferably 10 μm or more, and preferably 50 μm or less, 40
It is more preferably not more than μm, further preferably not more than 30 μm. When the thickness of the separator is within the above range, the insulating property and the mechanical strength will be good. Furthermore, it is possible to prevent deterioration of battery performance such as rate characteristics, and it is also possible to prevent deterioration of energy density of the entire non-aqueous electrolyte secondary battery.

Further, when a porous sheet or a 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, still more preferably 45% or more. It is preferably 90% or less, more preferably 85% or less, still more preferably 75% or less. When the porosity is within the above range, the membrane resistance does not become too large, and deterioration of the rate characteristics of the secondary battery can be suppressed. Further, the mechanical strength of the separator becomes appropriate, and the deterioration of the insulating property can be suppressed.

The average pore size of the separator is also arbitrary, but it is preferably 0.5 μm or less, and 0.
It is more preferably 2 μm or less, and preferably 0.05 μm or more. When the average pore diameter is within the above range, short circuit hardly occurs. Furthermore, the membrane resistance does not become too large, and it is possible to prevent deterioration of the rate characteristics of the secondary battery.
On the other hand, as the inorganic material, 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.

The separator may be in the form of a thin film such as a non-woven fabric, a woven fabric, or a microporous film. As the thin film separator, a 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 above-mentioned independent thin film shape, it is possible to use a separator formed by forming a composite porous layer containing the particles of the inorganic material on the surface layer of the positive electrode and/or the negative electrode using a binder made of resin. For example, it is possible to use alumina particles having a 90% particle size of less than 1 μm on both surfaces of the positive electrode and use a fluororesin as a binder to form a porous layer.

<3-1-6. Battery design>
(Electrode group)
The electrode group has a laminated structure including the positive electrode plate and the negative electrode plate with the separator interposed therebetween,
Also, any of the above-described positive electrode plate and negative electrode plate may be spirally wound with the separator interposed therebetween. The ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as the electrode group occupancy rate) is preferably 40% or more, more preferably 50% or more, and preferably 9%.
It is 5% or less, and more preferably 90% or less. When the electrode group occupancy rate is within the above range, it becomes difficult to reduce the battery capacity. In addition, since an appropriate void space can be secured, the internal pressure rises due to the expansion of the member due to the high temperature of the battery and the increase in the vapor pressure of the liquid component of the non-aqueous electrolyte solution, resulting in a secondary battery It is possible to reduce various characteristics such as charge/discharge repetitive performance and high temperature storage characteristics, and it is possible to avoid a case where a gas release valve that releases internal pressure to the outside operates.

(Current collecting structure)
Although the current collecting structure is not particularly limited, in order to more effectively realize the improvement of the discharge characteristics by the non-aqueous electrolyte solution of the present invention, a structure in which the resistance of the wiring portion or the joint portion is reduced is used. preferable. When the internal resistance is reduced in this way, the effect of using the non-aqueous electrolyte solution of the present invention is particularly well exhibited.

When the electrode group has the above-mentioned laminated structure, a structure formed by bundling the metal core portions of each electrode layer and welding the terminals is preferably used. Since the internal resistance increases when the area of one electrode increases, it is also preferable to provide a plurality of terminals in the electrode to reduce the resistance. When the electrode group has the above-described wound structure, the internal resistance can be lowered by providing a plurality of lead structures for the positive electrode and the negative electrode and bundling the lead structures.

(Protective element)
As a protective element, PTC (Posit) whose resistance increases when abnormal heat generation or excessive current flows
Examples thereof include an iv temperature coherent thermistor, a temperature fuse, and a valve (current cutoff valve) that cuts off the current flowing through the circuit due to a sudden increase in internal pressure or internal temperature of the battery during abnormal heat generation. It is preferable to select the protection element under the condition that it does not operate at high current under normal use, and it is more preferable to design the battery so as not to cause abnormal heat generation or thermal runaway without the protection element.

(Exterior body)
The non-aqueous electrolyte secondary battery of the present invention is usually constituted by accommodating the above-mentioned non-aqueous electrolyte, negative electrode, positive electrode, separator and the like in an exterior body (exterior case). There is no limitation on the outer package, and any known package can be used as long as the effects of the present invention are not significantly impaired.
The material of the outer case is not particularly limited as long as it is a substance stable with respect to the non-aqueous electrolyte solution used. Specifically, a nickel-plated steel plate, stainless steel, aluminum or an aluminum alloy, magnesium alloy, nickel, titanium, or another metal, or a laminated film (laminate film) of a resin and an aluminum foil is used. From the viewpoint of weight reduction, a metal of aluminum or aluminum alloy, or a laminated film is preferably used.

In the outer case using the metals, laser welding, resistance welding, ultrasonic welding to weld the metals to each other to form a sealed and sealed structure, or a caulking structure using the metals via a resin gasket. There are things to do. Examples of the outer case using the laminate film include those having a sealed structure by heat-sealing resin layers. In order to improve the sealing property, a resin different from the resin used for the laminate film may be interposed between the resin layers. In particular, when a resin layer is heat-sealed via a collector terminal to form a hermetically sealed structure, a metal and a resin are bonded, so a resin having a polar group or a modification having a polar group introduced as an intervening resin. Resin is preferably used.
The shape of the outer case is also arbitrary, and may be, for example, a cylindrical shape, a rectangular shape, a laminate type, a coin type, a large size, or the like.

<3-2. Non-aqueous electrolyte primary battery>
The non-aqueous electrolyte primary battery according to one embodiment of the present invention uses, for example, a material capable of storing 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 fluorinated graphite and manganese dioxide are preferable. As the negative electrode material, a simple metal such as zinc or lithium is preferable. As the non-aqueous electrolyte solution, the above-mentioned non-aqueous electrolyte solution of the present invention is used.

<3-3. Metal ion capacitor>
In the metal ion capacitor which is one embodiment of the present invention, for example, a material capable of forming an electric double layer is used for the positive electrode, and a material capable of storing and releasing metal ions is used for the negative electrode. Activated carbon is preferable as the positive electrode material. A carbonaceous material is preferable as the negative electrode material. As the non-aqueous electrolyte solution, the above-mentioned non-aqueous electrolyte solution of the present invention is used.

<3-4. Electric Double Layer Capacitor>
The 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 preferable as the electrode material. As the non-aqueous electrolyte solution, the above-mentioned non-aqueous electrolyte solution of the present invention is used.

Hereinafter, the present invention will be described in more detail 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, 1 part by mass of an aqueous dispersion of sodium carboxymethyl cellulose (concentration of sodium carboxymethyl cellulose of 1% by mass) and an aqueous dispersion of styrene-butadiene rubber (of styrene-butadiene rubber) were used as a thickener and a binder. 1 part by mass (concentration: 50% by mass) was added and mixed with a disperser to form a slurry. The obtained slurry was applied to a copper foil having a thickness of 10 μm, dried, and rolled with a press to obtain an active material layer having a width of 30 mm, a length of 40 mm, and a width of 5 mm and a length of 9 mm, which were uncoated. It was cut out into a shape having a portion to obtain a negative electrode.

[Production of positive electrode]
LiNi _0.5 Mn _0.2 Co _0.3 O ₂ 94% by mass as a positive electrode active material, acetylene black 3% by mass as a conductive material, and polyvinylidene fluoride (PVdF) as a binder.
3% by mass was mixed in an N-methylpyrrolidone solvent to form a slurry. The obtained slurry was applied to one surface of an aluminum foil having a thickness of 15 μm to which a conductive auxiliary agent was applied in advance, dried, and roll-pressed with a pressing machine to obtain an active material layer having a width of 30 mm and a length of 30 mm. 40 mm
And a shape having an uncoated portion having a width of 5 mm and a length of 9 mm was cut out to obtain a positive electrode.

[Preparation of non-aqueous electrolyte]
In a dry argon atmosphere, ethylene carbonate (EC) and dimethyl carbonate (DM
98 parts by mass of dry LiPF ₆ dissolved in a mixture of C) and ethylmethyl carbonate (EMC) (volume ratio 20:40:40) at a ratio of 1.2 mol/L.
1 part by mass of vinylene carbonate and 1 part by mass of lithium difluorophosphate were mixed to prepare a basic electrolytic solution. 99.5 parts by mass of this basic electrolyte and 2, shown by the following structural formula (1-A)
0.5 parts by mass of 2,2-trimethoxy-4,5-dimethyl-1,3,2-dioxaphospholane were mixed to prepare a non-aqueous electrolyte solution of Example 1.

[Manufacture of non-aqueous electrolyte secondary battery]
The positive electrode, the negative electrode, and the polyethylene separator were laminated in this order on the negative electrode, the separator, and the positive electrode to prepare a battery element. This battery element was inserted into a bag made of a laminated film in which both sides of aluminum (thickness 40 μm) were coated with resin layers so that the positive electrode terminal and the negative electrode terminal of the battery element protruded from the bag, and then the electrolytic solution was added. It is injected into the bag, vacuum sealed, and 4.3V
A sheet-shaped non-aqueous electrolyte secondary battery of Example 1 in which the battery was fully charged was prepared.

[Evaluation of initial discharge capacity]
With the non-aqueous electrolyte secondary battery sandwiched between glass plates to enhance the adhesion between the electrodes, 2
At 5° C., the battery was charged to 4.3 V with a constant current corresponding to 0.2 C, and then discharged to 2.8 V with a constant current of 0.2 C. This is done for 2 cycles to stabilize the battery and the third cycle is 0
． After being charged to 4.3 V with a constant current of 2 C, charging was performed with a constant voltage of 4.3 V until the current value reached 0.05 C, and discharged to a 2.8 V with a constant current of 0.2 C. After that, 0 at the 4th cycle
． After charging to 4.3V with a constant current of 2C, charge with a constant voltage of 4.3V until the current value reaches 0.05C, and discharge to 2.8V with a constant current of 0.2C to perform initial discharge. The capacity was calculated.

[Evaluation of initial output]
The battery for which the evaluation of the initial discharge capacity was completed was charged at 25° C. at a constant current of 0.2 C so that the capacity was half the initial discharge capacity. This is 0.5C, 1.0C, and 1 at -20 degreeC, respectively.
． After discharging at 5C, 2.0C and 2.5C, the voltage at 10 seconds was measured. The current value at 2.8 V was obtained from the current-voltage line, and 2.8 x (current value at 2.8 V) was used as the initial output (W).

[Evaluation of high temperature storage blisters]
The battery whose initial discharge capacity had been evaluated was immersed in an ethanol bath to measure the volume, which was taken as the volume before storage at high temperature. After charging to 4.3 V with a constant current corresponding to 0.2 C at 25° C., the battery was stored at 60° C. for 14 days, cooled to room temperature, and then immersed in an ethanol bath to measure the volume. Was defined as the volume after high temperature storage, and the value obtained by subtracting the volume before high temperature storage from the volume after high temperature storage was defined as high temperature storage swelling.

[Evaluation of storage capacity retention rate]
The battery whose volume was measured after storage at high temperature was discharged to 2.8 V at a constant current of 0.2 C at 25° C. and charged to 4.3 V at a constant current of 0.2 C, and then the current value was 0.05 C at a constant voltage. Was charged and discharged at a constant current of 0.2 C to 2.8 V, and a discharge capacity after high temperature storage at 0.2 C was obtained. Further, the storage capacity retention rate (%) was calculated from the following formula.
Storage capacity maintenance rate (%) = (discharge capacity after high temperature storage) / (initial discharge capacity) x 100

[Output after saving, evaluation of saving output retention rate]
The battery, which was evaluated for capacity retention after storage after high temperature storage, was charged at 25° C. with a constant current of 0.2 C so that the capacity was half the initial discharge capacity. 0.5C at -20°C, 1
． It was discharged at 0C, 1.5C, 2.0C and 2.5C, and the voltage at 10 seconds was measured. Obtain the current value at 2.8 V from the current-voltage line, and obtain 2.8 x (current value at 2.8 V).
Was stored and output (W). Further, the preservation output retention rate (%) was calculated from the following formula.
Storage output maintenance rate (%) = (output after storage) / (initial output) x 100

(Example 2)
A sheet-shaped non-aqueous electrolyte secondary battery of Example 2 was prepared and evaluated in the same manner as in Example 1 except that the compound (1-B) was used instead of the compound (1-A). went.

(Comparative Example 1)
A sheet-shaped non-aqueous electrolyte secondary battery of Comparative Example 1 was produced and evaluated in the same manner as in Example 1 except that the above-described basic electrolyte solution was used as it was.

(Comparative example 2)
A sheet-shaped non-aqueous electrolyte secondary battery of Comparative Example 1 was prepared and evaluated in the same manner as in Example 1 except that tributyl phosphite was used instead of the compound (1-A). ..
The evaluation results of Example 1 and Example 2 and Comparative Example 1 and Comparative Example 2 are shown in Table 1. The high temperature storage swelling, the storage capacity retention rate, and the storage output retention rate all showed relative values when the value of Comparative Example 1 was set to 100%.

As is clear from Table 1, Examples 1 and 2 are superior to Comparative Examples 1 and 2 in all evaluation items.

According to the non-aqueous electrolyte solution of the present invention, the cycle capacity retention rate during durability of the non-aqueous electrolyte secondary battery during cycle operation or high temperature storage, input/output characteristics after cycling (input/output retention rate), battery Blisters can be improved, which is useful. Therefore, the energy device such as the non-aqueous electrolyte solution of the present invention and the non-aqueous electrolyte secondary battery using the same can be used for various known applications. As a specific example, for example, a laptop computer, a pen input computer, a mobile computer, an electronic book player, a mobile phone, a mobile fax, a mobile copy, a mobile printer,
Headphone stereo, video movie, LCD TV, handy cleaner, portable CD, mini disk, transceiver, electronic organizer, calculator, memory card, portable tape recorder, radio, backup power supply, motor, automobile, motorcycle, motorbike,
Examples include bicycles, lighting equipment, toys, game machines, watches, electric tools, strobes, cameras, household backup power supplies, business backup power supplies, load leveling power supplies, natural energy storage power supplies, and lithium ion capacitors.

Claims (7)

A non-aqueous electrolyte containing a compound represented by the structural formula of P(OR) ₅ . (In the structural formula, each R is an independent hydrocarbon group having 1 to 8 carbon atoms, which may be linear or branched, and may be linked to each other to form a ring structure. ) The nonaqueous electrolysis according to claim 1, wherein the content of the compound represented by the structural formula of P(OR) ₅ is 0.0001% by mass or more and 5% by mass or less with respect to the total amount of the nonaqueous electrolytic solution. liquid. The non-aqueous electrolyte solution is an inorganic lithium halide salt, lithium fluorophosphate salt, lithium tungstate salt, lithium carboxylate salt, lithium sulfonate salt, lithium sulfate salt, lithium imide salt, lithium methide salt, lithium oxalate salt and The non-aqueous electrolyte solution according to claim 1 or 2, containing at least one compound selected from the group consisting of fluorine-containing organic lithium salts. The non-aqueous electrolyte solution contains LiPF ₆ , and the molar ratio of PF ₆ and P(OR) ₅ [PF ₆ ]/[P
(OR) ₅ ] is 2.0 or more and 2500 or less, The non-aqueous electrolyte solution of any one of Claims 1-3. The non-aqueous electrolytic solution contains at least one compound selected from the group consisting of a saturated cyclic carbonate, a chain carbonate, a chain carboxylic acid ester, a cyclic carboxylic acid ester, an ether compound and a sulfone compound. The non-aqueous electrolyte solution according to any one of 1 to 4. The non-aqueous electrolyte is a cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, a fluorinated unsaturated cyclic carbonate, a cyclic compound having an SO ₂ group, a compound having a cyano group, an isocyanate compound and a carvone. The non-aqueous electrolyte solution according to any one of claims 1 to 5, containing at least one compound selected from the group consisting of acid anhydrides. An energy device comprising a plurality of electrodes capable of occluding and releasing metal ions, and the non-aqueous electrolyte solution according to any one of claims 1 to 6.