JP6693200B2 - Non-aqueous electrolyte solution and non-aqueous electrolyte battery using the same - Google Patents

Description

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

Along with the rapid progress of portable electronic devices such as mobile phones and notebook personal computers, there has been an increasing demand for higher capacity batteries used for main power sources and backup power sources, such as nickel-cadmium batteries and nickel-carbon batteries. Non-aqueous electrolyte batteries, such as lithium-ion secondary batteries, which have higher energy density than hydrogen batteries, are attracting attention.
As an electrolytic solution of a lithium ion secondary battery, an electrolyte such as LiPF6, LiBF4, LiN (CF3SO2) 2, LiCF3 (CF2) 3SO3, a high dielectric constant solvent such as ethylene carbonate or propylene carbonate, dimethyl carbonate, diethyl carbonate, A representative example is a non-aqueous electrolyte solution dissolved in a mixed solvent with a low-viscosity solvent such as ethyl methyl carbonate.

  A carbonaceous material capable of inserting and extracting lithium ions is mainly used as a negative electrode active material of a lithium ion secondary battery, and natural graphite, artificial graphite, amorphous carbon, etc. are listed as typical examples. Be done. Further, a metal or alloy-based negative electrode using silicon, tin, or the like has been known for the purpose of further increasing the capacity. As the positive electrode active material, a transition metal composite oxide capable of mainly occluding and releasing lithium ions is mainly used, and typical examples of the transition metal include cobalt, nickel, manganese, iron and the like.

In a non-aqueous electrolytic solution secondary battery using such a non-aqueous electrolytic solution, reactivity varies depending on the composition of the non-aqueous electrolytic solution, and thus the non-aqueous electrolytic solution greatly changes battery characteristics. Various studies have been made on non-aqueous solvents and electrolytes in order to improve battery characteristics such as storage characteristics of non-aqueous electrolyte secondary batteries and to enhance battery safety during overcharge.
Patent Document 1 discloses a lithium battery including a positive electrode using manganese dioxide as an active material, a negative electrode using a lithium-aluminum alloy, and a nonaqueous electrolytic solution, by adding an acetoacetic acid ester compound to the electrolytic solution. Studies have been conducted to improve the rate of resistance change during storage at room temperature and the pulse discharge characteristics.

In Patent Document 2, a study is made to increase the reduction resistance of the electrolytic solution by adding a malonic acid ester or a tricarboxylic acid ester compound to the electrolytic solution for an electric double layer capacitor, and a study to suppress the leakage current during constant voltage charging. Has been done.
Patent Document 3 discloses that in a lithium secondary battery including a positive electrode using a lithium transition metal oxide represented by a lithium nickel cobalt manganese composite oxide as an active material, a negative electrode using graphite, and a non-aqueous electrolyte, Studies have been conducted to improve cycle characteristics by adding an acetoacetic acid ester compound or a specific ester compound to the liquid.

  In Patent Document 4, in a nonaqueous electrolytic solution using a magnesium salt as an electrolyte, a study is made to increase reversibility of magnesium precipitation / dissolution behavior by adding a specific ester such as an acetoacetic ester compound to the electrolytic solution. Has been done.

JP-A-2000-268860 International Publication No. 2008/001955 International Publication 2006/070546 International publication 2014/115784

  However, in recent years, the demand for improving the characteristics of lithium non-aqueous electrolyte secondary batteries has been increasing more and more, and all performances such as high temperature storage characteristics, energy density, output characteristics, lifespan, high-speed charging / discharging characteristics, and low temperature characteristics have been improved. It is required to have a high level of combination, but it has not been achieved yet. There is a trade-off relationship between durability performance including high-temperature storage characteristics and performance such as capacity, resistance, and output characteristics, and there is a problem that the overall performance is unbalanced.

  When the electrolytic solution containing a specific acetoacetate compound represented by methyl acetoacetate, ethyl acetoacetate, and ethyl diacetoacetate described in Patent Documents 1 and 3 is used, the rate of change in resistance during storage and pulse It is disclosed that the discharge characteristics and the cycle characteristics are improved. However, the reactivity of these specific acetoacetic acid ester compounds on the electrode is high, and there is room for improvement regarding the swelling of the storage gas during high temperature storage and the leakage current during constant voltage charging.

  The electrolytes implemented or described in Patent Documents 2 and 4 are only quaternary ammonium salts and magnesium salts, and the effect of using an alkali metal salt typified by a lithium salt as the electrolyte salt has not been clarified. Absent.

The present invention has been made in view of the above problems. That is, in a non-aqueous electrolyte battery, durability, capacity, resistance, output characteristics, and other performances have a good overall performance balance and can improve the high temperature characteristics of the battery in a well-balanced manner. An object is to provide an electrolytic solution battery.
As a result of intensive studies, the inventors of the present invention have found that the above problem can be solved by containing a specific compound in the electrolytic solution, and have completed the present invention.

The gist of the present invention is as shown below.
(A) A non-aqueous electrolyte for a non-aqueous electrolyte secondary battery comprising a positive electrode and a negative electrode capable of occluding and releasing metal ions, the non-aqueous electrolyte including an alkali metal salt and a non-aqueous solvent, represented by the following general formula: A non-aqueous electrolyte solution containing the compound represented by (1).

(In the formula (1), R ¹ , R ² and Y each have 1 to 1 carbon atoms which may have a substituent.
12 hydrocarbon groups are shown. R ¹ , R ² and Y may be the same or different. R ¹ , R ² and Y do not bond to each other to form a ring. )
(B) In the general formula (1), Y is an alkyl group having 1 to 12 carbon atoms, the non-aqueous electrolyte solution according to (a).
(C) In the general formula (1), R ¹ and R ² are alkyl groups having 1 to 12 carbon atoms, the non-aqueous electrolyte solution according to (a) or (b).
(D) The content of the compound represented by the general formula (1) is 0.001% by mass or more and 10% by mass or less based on the total amount of the non-aqueous electrolyte solution (a) to (a) The non-aqueous electrolyte solution according to any one of c).
(E) The non-aqueous electrolyte solution further contains a cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, a nitrile compound, an isocyanate compound, a compound having an isocyanuric acid skeleton, a fluorophosphate salt, and a fluorosulfonic acid. The non-aqueous electrolyte solution according to any one of (a) to (d), which contains at least one compound selected from the group consisting of salts and cyclic sulfonates.
(F) Cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, a nitrile compound, an isocyanate compound, a compound having an isocyanuric acid skeleton, a fluorophosphate salt, a fluorosulfonic acid salt, and a cyclic sulfonic acid The content of at least one compound selected from the group consisting of esters is 0.001% by mass or more and 10% by mass or less with respect to the total amount of the non-aqueous electrolyte solution. Aqueous electrolyte.
(G) In a non-aqueous electrolyte secondary battery comprising a positive electrode capable of occluding and releasing lithium ions, a negative electrode capable of occluding and releasing lithium ions, and a non-aqueous electrolyte secondary battery, the non-aqueous electrolyte solution comprises: ) To (f) is a non-aqueous electrolyte secondary battery, characterized by being a non-aqueous electrolyte secondary battery.
(H) The non-aqueous electrolyte secondary battery according to (g), wherein the negative electrode active material of the negative electrode capable of inserting and extracting lithium ions has carbon as a constituent element.
(I) The negative electrode active material of the negative electrode capable of inserting and extracting lithium ions contains at least one of silicon (Si) and tin (Sn) as a constituent element. Non-aqueous electrolyte secondary battery.
(J) The negative electrode active material of the negative electrode capable of inserting and extracting lithium ions is a mixture or composite of particles having silicon (Si) or tin (Sn) as a constituent element and graphite particles. The non-aqueous electrolyte solution according to (g).

According to the present invention, it is possible to provide a lithium non-aqueous electrolyte secondary battery having a good balance of overall performance in terms of durability and performance such as capacity, resistance and output characteristics.
The non-aqueous electrolyte secondary battery produced by using the non-aqueous electrolyte solution of the present invention, and the non-aqueous electrolyte secondary battery of the present invention, the action and principle of the secondary battery having a good overall performance balance Is not clear, but it is considered as follows. However, the present invention is not limited to the operation and principle described below.

The compound represented by the general formula (1) has an active hydrogen atom on a carbon atom sandwiched between carbonyl groups (α-position). It occurs tautomers of keto form and enol form by proton tautomerism in the hydrogen. Further, the compound of the present invention has not only a hydrogen atom but also a hydrocarbon group at the α-position. Since the hydrocarbon group has a higher electron donating property than the hydrogen atom, the acidity of the hydrogen atom is lowered. This suppresses a side reaction with a base component such as an alcoholate generated on the negative electrode, and at the same time, reduces the reduction reactivity on the negative electrode, so that generation of a gas represented by hydrogen is suppressed.

It is considered that the above-mentioned hydrocarbon group affects not only the reactivity of the hydrogen atom at the α-position but also the equilibrium state between the keto form and the enol form. Although the reactivity is extremely lower than that of the compound in which the α-position is not substituted with the hydrocarbon group, the compound represented by the general formula (1) is also slightly reduced on the negative electrode. It is considered that this reduction produces a radical anion at the α-position, and this radical anion also undergoes keto-enol tautomerism in the same manner as a hydrogen atom. Since the α-position is substituted with an electron-donating hydrocarbon group, the stability of the radical anion at the α-position is poor, and the equilibrium is considered to be biased toward the enol side. Since the enol form has an anion on the oxygen atom of the carbonyl group, it is considered that the enol form interacts more strongly with the transition metal element of the positive electrode active material. It is considered that this helps reduce the surface activity and suppresses the decomposition reaction between the surface of the positive electrode active material and the electrolytic solution.

  In order to solve the above problems, the present invention is a non-aqueous electrolyte solution for a non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of inserting and extracting metal ions, wherein the non-aqueous electrolyte solution is an alkali metal salt and a non-aqueous electrolyte solution. A non-aqueous electrolyte solution containing a compound represented by the following general formula (1) together with a solvent is used. As a result, they have found that the high temperature characteristics of the battery can be improved in a balanced manner, and have completed the present invention.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented without departing from the scope of the present invention.
In addition, “wt%”, “wt ppm” and “parts by weight” are synonymous with “wt%”, “ppm by weight” and “parts by mass”, respectively. Further, when simply described as "ppm", it means "weight ppm".

1. Non-aqueous electrolyte solution 1-1. Non-Aqueous Electrolyte Solution of the Present Invention The non-aqueous electrolyte solution of the present invention is characterized by containing a compound represented by the following general formula (1).
1-1-1. Compound represented by general formula (1)

In formula (1), R ¹ , R ² and Y each represent a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent. R ¹ , R ² and Y may be the same or different. R ¹ , R ² and Y do not bond to each other to form a ring.
Here, the above-mentioned substituents include a cyano group, an isocyanato group, an acyl group (-(C = O) -Ra), an acyloxy group (-O (C = O) -Ra), an oxycarbonyl group (-(C = O) O-Ra), sulfonyl group (-SO2-Ra), sulfonyloxy group (-O (SO2) -Ra), oxysulfonyl group (-(SO2) -O-Ra), carbonate group (-O- (C = O) -O-Ra), ether group (-O-Ra), acryl group, methacryl group and the like. Ra represents an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl group. Among them, cyano group, isocyanato group, acyl group (-(C = O) -Ra), acyloxy group (-O (C = O) -Ra), oxycarbonyl group (-(C = O) O-Ra are preferable. ), More preferably a cyano group, an acyl group (-(C = O) -Ra), an oxycarbonyl group (-(C = O) O-Ra), and particularly preferably a cyano group, an oxycarbonyl group (-( C = O) O-Ra), most preferably a cyano group.

In formula (1), R ¹ , R ² and Y each represent a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent. Among them, a hydrocarbon group having 2 to 10 carbon atoms which may have a substituent, more preferably a hydrocarbon group having 4 to 10 carbon atoms which may have a substituent, particularly preferably Is a hydrocarbon group having 4 to 8 carbon atoms which may have a substituent, and most preferably, a hydrocarbon group having 4 to 6 carbon atoms which may have a substituent.

  Specific examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, and an aryl group which may be linked via an alkylene group. Of these, an alkyl group, an alkenyl group and an alkynyl group are preferable, an alkyl group and an alkenyl group are more preferable, and an alkyl group is particularly preferable. When it is the above-mentioned hydrocarbon group, the compound represented by the general formula (1) can be prevented from reacting with a decomposition product of the electrolytic solution and causing an excessive increase in resistance.

  Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, s-butyl group, i-butyl group, t-butyl group, n-pentyl group, t. -Amyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group and the like can be mentioned. Among them, ethyl group, n-propyl group, n-butyl group, n-pentyl group, hexyl group, more preferably ethyl group, n-propyl group, n-butyl group, n-pentyl group, hexyl group, Particularly preferred are n-butyl group and hexyl group.

Specific examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantyl group and the like, and a cyclohexyl group and an adamantyl group are preferable.
Specific examples of the alkenyl group include a vinyl group, an allyl group, a methallyl group, a 2-butenyl group, a 3-methyl-2-butenyl group, a 3-butenyl group and a 4-pentenyl group. Among them, vinyl group, allyl group, methallyl group and 2-butenyl group are preferable, vinyl group, allyl group and methallyl group are more preferable, allyl group and methallyl group are most preferable, and allyl group is most preferable. This is because the above alkenyl group is suitable for steric hindrance and is relatively easy to produce.

Specific examples of the alkynyl group include an ethynyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a 4-pentynyl group and a 5-hexynyl group. Of these, an ethynyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a 2-propynyl group, a 3-butynyl group, and a 2-propynyl group are particularly preferable. This is because the alkynyl group described above is suitable for steric hindrance and is relatively easy to produce.
Specific examples of the aryl group which may be bonded via an alkylene group include a phenyl group, a tolyl group, a benzyl group, a phenethyl group and the like. Of these, a phenyl group is preferable.

From the viewpoint of the reactivity between the compound represented by the general formula (1) and the electrode, the hydrocarbon group having 1 to 12 carbon atoms represented by R ¹ , R ² , and Y in the general formula is unsubstituted. preferable. As a result, the reactivity on the electrode and the reactivity with the basic component such as the reduction product of the electrolytic solution generated on the electrode are lowered, and the deterioration due to the side reaction is suppressed. In particular, among R ¹ , R ² and Y, it is preferable that Y is an unsubstituted hydrocarbon group.
Specific examples of the compound represented by the general formula (1) used in the present invention include compounds having the following structures.

  Preferred are compounds having the following structures. This is because the reactivity of the compound on the electrode can be adjusted to a more suitable degree.

  More preferably, compounds having the following structures are mentioned. This is because the reactivity of the compound on the electrode can be adjusted to a more suitable degree.

  More preferably, the compound having the following structure is used. This is because the reaction of the compound on the electrode to increase the resistance can be adjusted to a suitable degree.

  Particularly preferred are compounds having the following structures. This is because side reactions on the electrodes can be suppressed and gas generation can be suppressed appropriately.

  Most preferably, compounds having the following structures are mentioned. This is because the steric hindrance of the compound is small and gas generation can be further suppressed.

  The compounding amount of the compound represented by the general formula (1) with respect to the total amount of the non-aqueous electrolyte solution of the present invention is not limited, and is arbitrary as long as the effects of the present invention are not significantly impaired, but the total amount of the non-aqueous electrolyte solution of the present invention is On the other hand, it is 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, particularly preferably 0.5 mass% or more. Further, usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 2% by mass or less, particularly preferably 1.5% by mass or less, and most preferably 1% by mass or less. It is contained at a concentration. Within the above range, the reactivity on the electrode and the reactivity of the electrolytic solution generated on the electrode with a basic component such as a reduction product can be adjusted, and the battery characteristics can be optimized.

As the compound represented by the general formula (1), one type may be used alone, or two or more types may be used in optional combination and ratio.
When the above range is satisfied, effects such as high temperature storage characteristics and discharge storage characteristics are further improved.
1-2. Specific Compound Suitable for Use in Non-Aqueous Electrolytic Solution of the Present Invention The non-aqueous electrolytic solution of the present invention includes, in addition to the compound represented by the general formula (1), carbon-carbon as a preferred specific compound. A cyclic carbonate having an unsaturated bond, a cyclic carbonate having a fluorine atom, a nitrile compound, an isocyanate compound, a compound having an isocyanuric acid skeleton, a fluorophosphate, a fluorosulfonate, and a cyclic sulfonate are selected from the group consisting of: From the viewpoint of improving battery characteristics, it is preferable to further contain at least one specific compound. Among them, a cyclic carbonate having a carbon-carbon unsaturated bond and a cyclic carbonate having a fluorine atom are more preferable from the viewpoint of improving battery characteristics.

The compound represented by the general formula (1) and the specific compound undergo a reduction reaction on the active material,
Form anions (nucleophiles) within the structure. In addition, these compounds have a nucleophilic attack accepting site in the structure. Therefore, it is considered that a composite film is formed with the compound represented by the general formula (1), the reduction product of the specific compound, and the reduction product of the electrolytic solution.
From the above, by co-adding these specific compounds and the compound represented by the general formula (1), they react with each other on the active material to form a composite film. Therefore, the reaction of the electrolytic solution on the surface of the active material is suppressed more than when each of the compounds is added alone, so that the battery characteristics are improved.

1-2-1. A cyclic carbonate having a carbon-carbon unsaturated bond A cyclic carbonate having a carbon-carbon unsaturated bond (hereinafter sometimes referred to as "unsaturated cyclic carbonate") includes a carbon-carbon double bond or a carbon-carbon triple bond. There is no particular limitation as long as it is a cyclic carbonate having a bond, and any unsaturated carbonate can be used. The cyclic carbonate having an aromatic ring is also included in the unsaturated cyclic carbonate.

The unsaturated cyclic carbonate, vinylene carbonates, aromatic rings or carbon carbonate-ethylene carbonate substituted with a substituent having a carbon-carbon double bond or a carbon-carbon triple bond, phenyl carbonates, vinyl carbonates, allyl carbonates, Examples thereof include catechol carbonates.
As vinylene carbonates,
Vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, phenyl vinylene carbonate, 4,5-diphenyl vinylene carbonate, vinyl vinylene carbonate, 4,5-divinyl vinylene carbonate, allyl vinylene carbonate, 4,5-diallyl vinylene carbonate , 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, 4-fluoro-5-vinylvinylene carbonate, 4-allyl-5-fluorovinylene carbonate and the like. ..

Specific examples of the ethylene carbonate substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond include
Vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate, 4-methyl-5-vinyl ethylene carbonate, 4-allyl-5-vinyl ethylene carbonate, ethynyl ethylene carbonate, 4,5-diethynyl ethylene carbonate, 4-methyl-5 -Ethynyl ethylene carbonate, 4-vinyl-5-ethynyl ethylene carbonate, 4-allyl-5-ethynyl ethylene carbonate, phenylethylene carbonate, 4,5-diphenylethylene carbonate, 4-phenyl-5-vinylethylene carbonate, 4-allyl -5-phenyl ethylene carbonate, allyl ethylene carbonate, 4,5-diallyl ethylene carbonate, 4-methyl-5-allyl ethylene carbonate, etc. are mentioned.

Among them, as a preferred unsaturated cyclic carbonate,
Vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, vinyl vinylene carbonate, 4,5-vinyl vinylene carbonate, allyl vinylene carbonate, 4,5-diallyl vinylene carbonate, vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate , 4-methyl-5-vinylethylene carbonate, allylethylene carbonate, 4,5-diallylethylene carbonate, 4-methyl-5-allylethylene carbonate, 4-allyl-5-vinylethylene carbonate, ethynylethylene carbonate, 4,5 -Diethynyl ethylene carbonate, 4-methyl-5-ethynyl ethylene carbonate, 4-vinyl-5-ethynyl ethylene carbonate.

Further, vinylene carbonate, vinyl ethylene carbonate and ethynyl ethylene carbonate are particularly preferable because they form a more stable interface protective film.
The molecular weight of the unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. The molecular weight is preferably 80 or more and 250 or less. 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. The molecular weight of the unsaturated cyclic carbonate is more preferably 85 or more, and more preferably 150 or less. The method for producing the unsaturated cyclic carbonate is not particularly limited, and a known method can be arbitrarily selected and produced.

As the unsaturated cyclic carbonate, one kind may be used alone, or two kinds or more may be used in optional combination and ratio. The amount 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, but is usually 0.001% by mass or more, preferably 0% by mass in 100% by mass of the non-aqueous electrolyte solution. 0.01 mass% or more, more preferably 0.1 mass% or more, further preferably 0.5 mass% or more, particularly preferably 1 mass% or more, and usually 10 mass% or less, preferably 5 mass% or less. , And more preferably 3% by mass
It is below. Within this range, the non-aqueous electrolyte battery is likely to exhibit a sufficient effect of improving cycle characteristics, the high temperature storage characteristics are deteriorated, the gas generation amount is increased, and the discharge capacity maintenance ratio is decreased. Easy to avoid.

1-2-2. Cyclic carbonate having a fluorine atom The cyclic carbonate compound having a fluorine atom includes a fluorinated product of a cyclic carbonate having an alkylene group having 2 to 6 carbon atoms, and a derivative thereof. For example, a fluorinated product of ethylene carbonate and a derivative thereof. Is mentioned. Examples of the fluorinated derivative of ethylene carbonate include a fluorinated derivative of ethylene carbonate substituted with an alkyl group (for example, an alkyl group having 1 to 4 carbon atoms). Among them, ethylene carbonate having 1 to 8 fluorine atoms and derivatives thereof are preferable.

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

Among them, at least one selected from the group consisting of monofluoroethylene carbonate, 4,5-difluoroethylene carbonate and 4,5-difluoroethylene carbonate gives high ionic conductivity and preferably forms an interface protective film. Is more preferable.
As the cyclic carbonate compound having a fluorine atom, one kind may be used alone, and two kinds or more may be used in optional combination and ratio.

As the cyclic carbonate compound having a fluorine atom, one kind may be used alone, and two kinds or more may be used in optional combination and ratio. There is no limitation on the amount of the halogenated cyclic carbonate compounded with respect to the entire non-aqueous electrolytic solution of the present invention, and it is arbitrary as long as the effect of the present invention is not significantly impaired, but usually 0.001 mass% in 100 mass% of the non-aqueous electrolytic solution. Or more, preferably 0.
01% by mass or more, more preferably 0.1% by mass or more, further preferably 0.5% by mass or more, particularly preferably 1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, It is more preferably 3% by mass or less. However, monofluoroethylene carbonate may be used as a solvent, and in that case, the content is not limited to the above content. Further, the cyclic carbonate having a fluorine atom can be used as an auxiliary agent in the non-aqueous electrolyte solution of the present invention as described above, and the following 1-4. As shown in the solvent, it can also be used as a non-aqueous solvent.

1-2-3. Nitrile Compound The type of the nitrile compound is not particularly limited as long as it is a compound having a cyano group in the molecule.
Specific examples of the nitrile compound 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-dif Oropropionitrile, 3,3-difluoropropionitrile, 2,2,3-trifluoropropionitrile, 3,3,3-trifluoropropionitrile, 3,3'-oxydipropionitrile, 3,3 ' Compounds having one nitrile group such as thiodipropionitrile, 1,2,3-propanetricarbonitrile, 1,3,5-pentanetricarbonitrile and pentafluoropropionitrile Malononitrile, succinonitrile, glutaro Nitrile, adiponitrile, pimelonitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile, dodecanedinitrile, methylmalononitrile, ethylmalononitrile, isopropylmalononitrile, tert-butylmalononitrile, methylsuccinonitrile, 2,2-di Tylsuccinonitrile, 2,3-dimethylsuccinonitrile, 2,3,3-trimethylsuccinonitrile, 2,2,3,3-tetramethylsuccinonitrile, 2,3-diethyl-2,3-dimethylsuccinonitrile Cinonitrile, 2,2-diethyl-3,3-dimethylsuccinonitrile, bicyclohexyl-1,1-dicarbonitrile, bicyclohexyl-2,2-dicarbonitrile, bicyclohexyl-3,3-dicarbonitrile 2,5-dimethyl-2,5-hexanedicarbonitrile, 2,3-diisobutyl-2,3-dimethylsuccinonitrile, 2,2-diisobutyl-3,3-dimethylsuccinonitrile, 2-methylglucurone Talonitrile, 2,3-dimethylglutaronitrile, 2,4-dimethylglutaronitrile, 2,2,3,3-tetramethyl Glutaronitrile, 2,2,4,4-tetramethylglutaronitrile, 2,2,3,4-tetramethylglutaronitrile, 2,3,3,4-tetramethylglutaronitrile, maleonitrile, fumaronitrile, 1,4-dicyanopentane, 2,6-dicyanoheptane, 2,7-dicyanooctane, 2,8-dicyanononane, 1,6-dicyanodecane, 1,2-didianobenzene, 1,3-dicyanobenzene, 1 , 4-dicyanobenzene, 3,3 ′-(ethylenedioxy) dipropionitrile, 3,3 ′-(ethylenedithio) dipropionitrile, 3,9-bis (2-cyanoethyl) -2,4,8, A compound having two nitrile groups such as 10-tetraoxaspiro [5,5] undecane;
Examples thereof include compounds having three cyano groups such as cyclohexanetricarbonitrile, triscyanoethylamine, triscyanoethoxypropane, tricyanoethylene, pentanetricarbonitrile, propanetricarbonitrile and heptanetricarbonitrile.

  Of these, lauronitrile, crotononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile, dodecanedinitrile, fumaronitrile, 3,9-bis (2-cyanoethyl)- 2,4,8,10-Tetraoxaspiro [5,5] undecane is preferred from the viewpoint of improving storage characteristics. Further, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile, dodecanedinitrile, fumaronitrile, 3,9-bis (2-cyanoethyl) -2,4,8,10-tetra Dinitrile compounds such as oxaspiro [5,5] undecane are particularly preferred.

  As the nitrile compound, one kind may be used alone, and two kinds or more may be used in optional combination and ratio. There is no limitation on the amount of the nitrile compound compounded 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 in the non-aqueous electrolyte solution 100% by mass, usually 0.001% by mass or more, It is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 2% by mass. Below, most preferably it is 1 mass% or less. When the above range is satisfied, the effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-2-4. Isocyanate Compound The type of isocyanate compound is not particularly limited as long as it is a compound having an isocyanate group in the molecule.
Specific examples of the isocyanate compound include, for example,
Hydrocarbon-based monoisocyanate compounds such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, butyl isocyanate, tertiary 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;
Monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-diisocyanate Natopropane, 1,4-diisocyanato-2-butene, 1,4-diisocyanato-2-fluorobutane, 1,4-diisocyanato-2,3-difluorobutane, 1,5-diisocyanato-2-pentene, 1,5 -Diisocyanato-2-methylpentane, 1,6-diisocyanato-2-hexene, 1,6-diisocyanato-3-hexene, 1,6 Diisocyanato-3-fluorohexane, 1,6-diisocyanato-3,4-difluorohexane, toluene diisocyanate, xylene diisocyanate, tolylene diisocyanate, 1,2-bis (isocyanatomethyl) cyclohexane, 1,3-bis (isocyanato) Methyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-1,1 ′ -Diisocyanate, dicyclohexylmethane-2,2'-diisocyanate, dicyclohexylmethane-3,3'-diisocyanate, dicyclohexylmethane-
4,4′-diisocyanate, bicyclo [2.2.1] heptane-2,5-diylbis (
Methylisocyanate), bicyclo [2.2.1] heptane-2,6-diylbis (methylisocyanate), isophorone diisocyanate, carbonyl diisocyanate, 1,4-diisocyanatobutane-1,4-dione, 1,5- Diisocyanatopentane-1,5-
Hydrocarbon-based diisocyanate compounds such as dione, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate;
Isocyanate compounds such as diisocyanato sulfone, (ortho-, meta-, para-) toluenesulfonyl isocyanate, benzenesulfonyl isocyanate, fluorosulfonyl isocyanate, phenoxysulfonyl isocyanate, pentafluorophenoxysulfonyl isocyanate, and methoxysulfonyl isocyanate;
Etc.

Of these, monoisocyanate compounds having a carbon-carbon unsaturated bond such as vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, and propynyl isocyanate;
Monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-bis ( Isocyanatomethyl) cyclohexane, dicyclohexylmethane-4,4'-diisocyanate, bicyclo [2.2.1] heptane-2,
5-diylbis (methylisocyanate), bicyclo [2.2.1] heptane-2,6-diylbis (methylisocyanate), isophorone diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4 A hydrocarbon-based diisocyanate compound such as trimethylhexamethylene diisocyanate;
Isocyanate compounds such as diisocyanato sulfone, (ortho-, meta-, para-) toluenesulfonyl isocyanate, benzenesulfonyl isocyanate, fluorosulfonyl isocyanate, phenoxysulfonyl isocyanate, pentafluorophenoxysulfonyl isocyanate, and methoxysulfonyl isocyanate;
Is preferable from the viewpoint of improving cycle characteristics and storage characteristics.

  More preferred are allyl isocyanate, hexamethylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, diisocyanato sulfone, (ortho-, meta-, para-) toluenesulfonyl isocyanate, and particularly preferred is hexamethylene. Diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane and (ortho-, meta-, para-) toluenesulfonyl isocyanate are preferred, and hexamethylene diisocyanate and 1,3-bis (isocyanatomethyl) cyclohexane are most preferred. preferable.

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

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

For the purpose of promoting a reaction based on a compound having at least two isocyanate groups in the molecule and obtaining a higher effect, a metal catalyst such as dibutyltin dilaurate or 1,8-diazabicyclo [5.4.0] undecene- It is also preferable to use an amine-based catalyst such as 7 in combination.
Further, as the compound having an isocyanate group, one type may be used alone, or two or more types may be used in optional combination and ratio.

  The compounding amount of the compound having an isocyanate group with respect to the whole non-aqueous electrolytic 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, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, further preferably The content is 2% by mass or less, particularly preferably 1% by mass or less, and most preferably 0.5% by mass or less.

When the above range is satisfied, the effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.
1-2-5. Compound having isocyanuric acid skeleton

  In formula (A), R1 to R3 may be the same or different from each other, and are an organic group having 1 to 20 carbon atoms which may have a substituent. However, at least one of R1 to R3 has a carbon-carbon unsaturated bond or a cyano group. Preferably, in the formula (A), R1 to R3 may be the same or different from each other, and are an organic group having 1 to 10 carbon atoms which may have a substituent. More preferably, in the formula (A), at least one of R1 to R3 is an organic group having a carbon-carbon unsaturated bond.

Here, the organic group refers to a functional group composed of an atom selected from the group consisting of carbon atom, hydrogen atom, nitrogen atom, oxygen atom, silicon atom, sulfur atom and halogen atom.
Specific examples of the organic group which may have a substituent include an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an alkynyl group, an aryl group, a cyano group, an acryl group, a methacryl group, a vinylsulfonyl group, a vinylsulfo group and the like. Is mentioned.

Examples of the substituent here include a halogen atom and an alkylene group. Moreover, an unsaturated bond or the like may be contained in part of the alkylene group. Among the halogen atoms, a fluorine atom is preferable.
Specific examples of the alkyl group which may have a substituent include direct groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group and tert-butyl group. Examples thereof include chain-like or branched-chain alkyl groups or cyclic alkyl groups such as cyclopropyl group, cyclopentyl group, cyclohexyl group and the like.

  Specific examples of the alkenyl group which may have a substituent include a vinyl group, an allyl group, a methallyl group and a 1-propenyl group. Specific examples of the alkynyl group which may have a substituent include an ethynyl group, a propargyl group, a 1-propynyl group and the like. Specific examples of the aryl group which may have a substituent include a phenyl group, a tolyl group, a benzyl group and a phenethyl group.

Of these, an alkyl group, an alkenyl group, an alkynyl group, an acryl group, a methacryl group, an aryl group, a cyano group, a vinylsulfonyl group, and a vinylsulfo group which may have a substituent are preferable.
More preferably, an alkyl group which may have a substituent, an alkenyl group, an alkynyl group, an acryl group, a methacryl group and a cyano group may be mentioned.

Particularly preferably, an alkyl group which may have a substituent, an alkenyl group, an acryl group, a methacryl group and a cyano group are exemplified.
Most preferably, an alkyl group which may have a substituent, an allyl group and a methallyl group are exemplified. Particularly, an unsubstituted allyl group or methallyl group is preferable. An allyl group is preferred from the viewpoint of film forming ability.

  As the compound used in the present invention, the compound represented by the general formula (A) is used, and specific examples thereof include compounds having the following structures.

  Preferred are compounds having the following structures.

  More preferably, the compound having the following structure may be mentioned.

  Particularly preferred are compounds having the following structures.

  Most preferably, compounds having the following structures are mentioned.

  Among these most preferable compounds, the compounds having the following structures are preferable from the viewpoint of film forming ability.

There is no limitation on the compounding amount of the compound represented by the general formula (A) with respect to the entire non-aqueous electrolyte solution of the present invention, and it is optional as long as the effect of the present invention is not significantly impaired. Usually 0.001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and usually 10 mass% or less, preferably 5 mass% or less, more preferably 3 mass% The following content is more preferably 2% by mass or less, particularly preferably 1% by mass or less, and most preferably 0.5% by mass or less.

When the above range is satisfied, the effects such as output characteristics, load characteristics, cycle characteristics, high temperature storage characteristics, and battery swelling are further improved.
1-2-6. Difluorophosphate The countercation of the difluorophosphate is not particularly limited, but lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR13R14R15R16 (wherein R13 to R16 are each independently Represents a hydrogen atom or an organic group having 1 to 12 carbon atoms), and the like.

  The organic group having 1 to 12 carbon atoms represented by R13 to R16 of ammonium is not particularly limited, but for example, an alkyl group optionally substituted with a halogen atom, a halogen atom or an alkyl group may be substituted. Examples thereof include a good cycloalkyl group, an aryl group which may be substituted with a halogen atom or an alkyl group, and a nitrogen atom-containing heterocyclic group which may have a substituent. Among them, as R13 to R16, a hydrogen atom, an alkyl group, a cycloalkyl group, a nitrogen atom-containing heterocyclic group, or the like is independently preferable.

Specific examples of the difluorophosphate include:
Examples thereof include lithium difluorophosphate, sodium difluorophosphate, potassium difluorophosphate, and the like, with lithium difluorophosphate being preferred.
As the difluorophosphate, one kind may be used alone, or two kinds or more may be used in optional combination and ratio. In addition, the compounding amount of the difluorophosphate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired.

The compounding amount of the difluorophosphate is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 5% by mass in 100% by mass of the non-aqueous electrolyte solution. % Or less, preferably 3% by mass or less, more preferably 2% by mass or less, still more preferably 1% by mass or less, and most preferably 0.5% by mass or less.
Within this range, the non-aqueous electrolyte battery is likely to exhibit a sufficient effect of improving cycle characteristics, the high temperature storage characteristics are deteriorated, the gas generation amount is increased, and the discharge capacity maintenance ratio is decreased. Easy to avoid.

1-2-7. Fluorosulfonate The counter cation of fluorosulfonate is not particularly limited, but lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR13R14R15R16 (wherein R13 to R16 are each independently Represents a hydrogen atom or an organic group having 1 to 12 carbon atoms), and the like.

  The organic group having 1 to 12 carbon atoms represented by R13 to R16 of ammonium is not particularly limited, but for example, an alkyl group optionally substituted with a halogen atom, a halogen atom or an alkyl group may be substituted. Examples thereof include a good cycloalkyl group, an aryl group which may be substituted with a halogen atom or an alkyl group, and a nitrogen atom-containing heterocyclic group which may have a substituent. Among them, as R13 to R16, a hydrogen atom, an alkyl group, a cycloalkyl group, a nitrogen atom-containing heterocyclic group, or the like is independently preferable.

Specific examples of the fluorosulfonate include lithium fluorosulfonate, sodium fluorosulfonate, potassium fluorosulfonate, rubidium fluorosulfonate, and cesium fluorosulfonate, and lithium fluorosulfonate is preferable.
The fluorosulfonates may be used alone or in any combination of two or more in any ratio. Further, the amount of the fluorosulfonate salt is not particularly limited, and is arbitrary as long as the effect of the present invention is not significantly impaired.

The blending amount of the fluorosulfonate is generally 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass in 100% by mass of the non-aqueous electrolyte solution. %, Preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 2% by mass or less, and most preferably 1% by mass or less.
Within this range, the non-aqueous electrolyte battery is likely to exhibit a sufficient effect of improving cycle characteristics, the high temperature storage characteristics are deteriorated, the gas generation amount is increased, and the discharge capacity maintenance ratio is decreased. Easy to avoid.

1-2-8. Cyclic sulfonic acid ester The cyclic sulfonic acid ester compound is not particularly limited in type.
Specific examples of the cyclic sulfonic acid ester 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-propane sultone, 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-protone Pen-1,3-sultone, 3-methyl-1-propene-1,3-sultone, 1-methyl-2-propene-1,3-sultone, 2-methyl-2-propene-1,3-sultone, 3-methyl-2-propene-1,3-sultone, 1,4-butanesultone, 1-fluoro-1,4-butanesultone, 2-fluoro-1,4-butanesultone, 3-fluoro-1,4-butanesultone, 4-fluoro-1,4-butanesultone, 1-methyl-1,4-butanesultone, 2-methyl-1,4-butanesultone, 3-methyl-1,4-butanesultone, 4-methyl-1,4-butanesultone, 1-butene-1,4-sultone, 2-butene-1,4-sultone, 3-butene-1,4-sultone, 1-fluoro-1-butene-1,4-sultone, 2-fluoro 1-butene-1,4-sultone, 3-fluoro-1-butene-1,4-sultone, 4-fluoro-1-butene-1,4-sultone, 1-fluoro-2-butene-1,4- Sultone, 2-fluoro-2-butene-1,4-sultone, 3-fluoro-2-butene-1,4-sultone, 4-fluoro-2-butene-1,4-sultone, 1-fluoro-3- Butene-1,4-sultone, 2-fluoro-3-butene-1,4-sultone, 3-fluoro-3-butene-1,4-sultone, 4-fluoro-3-butene-1,4-sultone, 1-methyl-1-butene-1,4-sultone, 2-methyl-1-butene-1,4-sultone, 3-methyl-1-butene-1,4-sultone, 4-methyl-1-butene- 1,4-sultone, 1-methyl-2-butene-1 4-sultone, 2-methyl-2-butene-1,4-sultone, 3-methyl-2-butene-1,4-sultone, 4-methyl-2-butene-1,4-sultone, 1-methyl- 3-butene-1,4-sultone, 2-methyl-3-butene-1,4-sultone, 3-methyl-3-butene-1,4-sultone, 4-methyl-3-butene-1,4- Sultone, 1,5-pentane sultone, 1-fluoro-1,5-pentane sultone, 2-fluoro-1,5-pentane sultone, 3-fluoro-1,5-pentane sultone, 4-fluoro-1,5- Pentane sultone, 5-fluoro-1,5-pentane sultone, 1-methyl-1,5-pentane sultone, 2-methyl-1,5-pentane sultone, 3-methyl-1,5-pentane sultone, 4-methyl -1,5 -Pentane sultone, 5-methyl-1,5-pentane sultone, 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 -Pe Ten-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-Me Ru-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- Sultone conversion such as pentene-1,5-sultone Compound;

Sulfate compounds such as methylene sulphate, ethylene sulphate, propylene sulphate;
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- Oxatiazinan-2,2
-Dioxide, 6-methyl-1,2,6-oxathiazinane-2,2-dioxide, 5,6-dihydro-1,2,6-oxathiazine-2,2-dioxide, 3,4-dihydro-1,2 Nitrogen-containing compounds such as 6,6-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-oxathia Sulan-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-oxathiaphosphinane-2,2-dioxide, 3-methyl-1,2,3-oxathiaphosphinane-2,2,3-trioxide, 3-methoxy-1, 2,3-oxathiaphosphinan-2,2,3-trioxide, 1,2,4-oxathiaphosphinan-2,2-dioxide, 4-methyl-1,2,4-oxathiaphosphinan-2 , 2-dioxide, 4-methyl-1,2,4-oxathiaphosphinane-2,2,3-trioxide, 4-methyl-1,5,2,4-dioxathiaphosphinane-2,4- Dioxide, 4-methoxy 1,5,2,4-dioxathiaphosphinane-2,4-dioxide, 3-methoxy-1,2,4-oxathiaphosphinane-2,2,3-trioxide, 1,2,5-oxa Thiaphosphinan-2,2-dioxide, 5-methyl-1,2,5-oxathiaphosphinan-2,2-dioxide, 5-methyl-1,2,5-oxathiaphosphinan-2,2,2 3-trioxide, 5-methoxy-1,2,5-oxathiaphosphinane-2,2,3-trioxide, 1,2,6-oxathiaphosphinane-2,2-dioxide, 6-methyl-1, 2,6-oxathiaphosphinane-2,2-dioxide, 6-methyl-1,2,6-oxathiaphosphinane-2,2,3-trioxide, 6-methoxy-1,2,6-oxathia Phosphinan-2,2 , Phosphorus-containing compounds such as 3-trioxide;

  Among 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 and ethylene methane di sulfonate are preferable from the viewpoint of improving storage characteristics, and 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3 -Fluoro-1,3-propane sultone and 1-propene-1,3-sultone are more preferable.

The cyclic sulfonate compound may be used alone or in combination of two or more in any combination and ratio. There is no limitation on the amount of the cyclic sulfonate compound compounded 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 usually 0.001 mass% in 100 mass% of the non-aqueous electrolyte solution. % Or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 4% by mass or less, particularly preferably It is 3 mass% or less, and most preferably 2 mass% or less. When the above range is satisfied, the effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-3. Electrolyte <alkali metal salt>
As the alkali metal salt used as the electrolyte, a lithium salt, a sodium salt, a potassium salt or the like is used, but usually a lithium salt is used. The lithium salt is not particularly limited as long as it is known to be used for this purpose, and any one can be used, and specific examples include the following.

For example, inorganic lithium salts such as LiPF6, LiBF4, LiClO4, LiAlF4, LiSbF6, LiTaF6 and LiWF7;
Lithium tungstates such as LiWOF5;
Lithium carboxylic acid salts such as HCO2Li, CH3CO2Li, CH2FCO2Li, CHF2CO2Li, CF3CO2Li, CF3CH2CO2Li, CF3CF2CO2Li, CF3CF2CF2CO2Li, CF3CF2CF2CF2CO2Li;
Lithium sulfonates such as FSO3Li, CH3SO3Li, CH2FSO3Li, CHF2SO3Li, CF3SO3Li, CF3CF2SO3Li, CF3CF2CF2SO3Li, CF3CF2CF2CF2SO3Li;
LiN (FCO) 2, LiN (FCO) (FSO2), LiN (FSO2) 2, LiN (FSO2) (CF3SO2), LiN (CF3SO2) 2, LiN (C2F5SO2) 2, lithium cyclic 1,2-perfluoroethane Lithium imide salts such as sulfonyl imide, lithium cyclic 1,3-perfluoropropane disulfonyl imide, LiN (CF3SO2) (C4F9SO2);
LiC (FSO2) 3, LiC (CF3SO2) 3, LiC (C2F5SO2) 3 and other lithium methide salts;
Lithium difluorooxalatoborate, lithium bis (oxalato) borate and other lithium oxalatoborate salts;
Lithium tetrafluorooxalatophosphate, lithium difluorobis (oxalato) phosphate, lithium tris (oxalato) phosphate, and other lithium oxalatophosphate salts;
In addition, LiPF4 (CF3) 2, LiPF4 (C2F5) 2, LiPF4 (CF3SO2) 2, LiPF4 (C2F5SO2) 2, LiBF3CF3, LiBF3C2F5, LiBF3C3F7, LiBF2 (CF3) 2, LiBF2 (SO2F2), LiBF2 (SO2F5) 2, Fluorine-containing organic lithium salts such as LiBF2 (C2F5SO2) 2; and the like.

  Among them, LiPF6, LiBF4, LiSbF6, LiTaF6, FSO3Li, CF3SO3Li, LiN (FSO2) 2, LiN (FSO2) (CF3SO2), LiN (CF3SO2) 2, LiN (C2F5SO2) 2, lithium cyclic 1,2-perfluoroethane. Sulfonylimide, lithium cyclic 1,3-perfluoropropanedisulfonylimide, LiC (FSO2) 3, LiC (CF3SO2) 3, LiC (C2F5SO2) 3, lithium bisoxalatoborate, lithium difluorooxalatoborate, lithium tetrafluorooxa Latophosphate, lithium difluorobisoxalatophosphate, LiBF3CF3, LiBF3C2F5, LiPF3 (CF3) 3, LiPF3 (C2F5) 3, etc. have high output characteristics and high output. Over preparative charge and discharge characteristics, high-temperature storage characteristics, particularly preferred from the viewpoint that an effect of improving the cycle characteristics and the like.

These lithium salts may be used alone or in combination of two or more. A preferred example of using two or more kinds in combination is the combined use of LiPF6 and LiBF4, LiPF6 and LiN (FSO2) 2, LiPF6 and FSO3Li, etc., which has the effect of improving load characteristics and cycle characteristics.
In this case, the concentration of LiBF4 or FSO3Li with respect to the total 100% by mass of the non-aqueous electrolyte solution is not limited as long as it does not impair the effect of the present invention, and the non-aqueous electrolyte solution of the present invention is not limited. It is usually 0.01% by mass or more, preferably 0.1% by mass or more, and usually 30% by mass or less, preferably 20% by mass or less.

  Another example is the combined use of an inorganic lithium salt and an organic lithium salt, and the combined use of both is effective in suppressing deterioration due to high temperature storage. Examples of the organic lithium salt include CF3SO3Li, LiN (FSO2) 2, LiN (FSO2) (CF3SO2), LiN (CF3SO2) 2, LiN (C2F5SO2) 2, lithium cyclic 1,2-perfluoroethanedisulfonylimide, and lithium cyclic 1 , 3-perfluoropropanedisulfonylimide, LiC (FSO2) 3, LiC (CF3SO2) 3, LiC (C2F5SO2) 3, lithium bisoxalatoborate, lithium difluorooxalatoborate, lithium tetrafluorooxalatophosphate, lithium difluorobis Oxalatophosphate, LiBF3CF3, LiBF3C2F5, LiPF3 (CF3) 3, LiPF3 (C2F5) 3 and the like are preferable. In this case, the ratio of the organic lithium salt to 100% by mass of the whole non-aqueous electrolyte is preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and preferably 30% by mass or less. It is particularly preferably 20% by mass or less.

The concentration of these lithium salts in the non-aqueous electrolytic solution is not particularly limited as long as the effect of the present invention is not impaired, but the electric conductivity of the electrolytic solution is set in a good range to ensure good battery performance. Therefore, the total molar concentration of lithium in the non-aqueous electrolytic solution is preferably 0.3 mol / L or more, more preferably 0.4 mol / L or more, further preferably 0.5 mol / L or more, and It is preferably 3 mol / L or less, more preferably 2.5 mol / L or less, and further preferably 2.0 mol / L or less.
When the total molar concentration of lithium is within the above range, the electric conductivity of the electrolytic solution becomes sufficient, and the decrease in electric conductivity due to the increase in viscosity and the resulting decrease in battery performance are prevented.

1-4. Non-Aqueous Solvent The non-aqueous solvent in the present invention is not particularly limited, and a known organic solvent can be used. Examples thereof include cyclic carbonates having no fluorine atom, chain carbonates, cyclic and chain carboxylic acid esters, ether compounds and sulfone compounds.

<Cyclic carbonate having no fluorine atom>
Examples of the cyclic carbonate having no fluorine atom include a cyclic carbonate having an alkylene group having 2 to 4 carbon atoms.
Specific examples of the fluorine-free cyclic carbonate having an alkylene group having 2 to 4 carbon atoms include ethylene carbonate, propylene carbonate, and butylene carbonate. Among them, ethylene carbonate and propylene carbonate are particularly preferable from the viewpoint of improving battery characteristics due to improvement in lithium ion dissociation degree.

As the cyclic carbonate having no fluorine atom, one kind may be used alone, and two kinds or more may be used in optional combination and ratio.
The blending amount of the cyclic carbonate having no fluorine atom is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but the blending amount when one type is used alone is 100% by volume of the non-aqueous solvent. Medium is 5% by volume or more, more preferably 10% by volume or more. By setting it in this range, it is possible to avoid a decrease in electric conductivity due to a decrease in the dielectric constant of the non-aqueous electrolyte solution, and a large current discharge characteristic of the non-aqueous electrolyte battery, stability to the negative electrode, and a good cycle characteristic range. And easy to do. Further, it is 95% by volume or less, more preferably 90% by volume or less, and further preferably 85% by volume or less. By setting it in this range, the viscosity of the non-aqueous electrolyte solution can be set to an appropriate range, the decrease in ionic conductivity can be suppressed, and the load characteristics of the non-aqueous electrolyte battery can be easily set to a good range.

<Chain carbonate>
As the chain carbonate, a chain carbonate having 3 to 7 carbon atoms is preferable, and a dialkyl carbonate having 3 to 7 carbon atoms is more preferable.
Specific examples of chain carbonates include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate, methyl-n-propyl carbonate, n-butyl methyl carbonate, isobutyl methyl. Carbonate, t-butyl methyl carbonate, ethyl-n-propyl carbonate, n-butyl ethyl carbonate, isobutyl ethyl carbonate, t-butyl ethyl carbonate and the like can be mentioned.

Among them, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate and methyl-n-propyl carbonate are preferable, and dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate are particularly preferable. is there.
Further, chain carbonates having a fluorine atom (hereinafter sometimes referred to as “fluorinated chain carbonate”) can also be suitably used.

The number of fluorine atoms contained in the fluorinated chain carbonate is not particularly limited as long as it is 1 or more, but is usually 6 or less, 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 and its derivatives, fluorinated ethylmethyl carbonate and its derivatives, fluorinated diethyl carbonate and its derivatives, and the like.

Examples of the fluorinated dimethyl carbonate and its derivatives include fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, bis (fluoromethyl) carbonate, bis (difluoro) methyl carbonate, bis (trifluoromethyl) carbonate and the like. Be done.
Examples of the fluorinated ethyl methyl carbonate and its derivative include 2-fluoroethyl methyl carbonate, ethyl fluoromethyl carbonate, 2,2-difluoroethyl methyl carbonate, 2-fluoroethyl fluoromethyl carbonate, ethyl difluoromethyl carbonate, 2,2,2. -Trifluoroethyl methyl carbonate, 2,2-difluoroethyl fluoromethyl carbonate, 2-fluoroethyl difluoromethyl carbonate, ethyl trifluoromethyl carbonate and the like can be mentioned.

  Examples of the fluorinated diethyl carbonate and its derivative include ethyl- (2-fluoroethyl) carbonate, ethyl- (2,2-difluoroethyl) carbonate, bis (2-fluoroethyl) carbonate, ethyl- (2,2,2-). Trifluoroethyl) carbonate, 2,2-difluoroethyl-2'-fluoroethyl carbonate, bis (2,2-difluoroethyl) carbonate, 2,2,2-trifluoroethyl-2'-fluoroethyl carbonate, 2, 2,2-trifluoroethyl-2 ', 2'-difluoroethyl carbonate, bis (2,2,2-trifluoroethyl) carbonate and the like can be mentioned.

As the chain carbonate, one kind may be used alone, and two kinds or more may be used in optional combination and ratio.
The content of the chain carbonate in 100% by volume of the non-aqueous solvent is preferably 5% by volume or more, more preferably 10% by volume or more, further preferably 15% by volume or more. By setting the lower limit in this way, the viscosity of the non-aqueous electrolyte solution can be set to an appropriate range, the decrease in ionic conductivity can be suppressed, and the large-current discharge characteristics of the non-aqueous electrolyte battery can be easily set to a good range. Further, the chain carbonate is preferably 90% by volume or less, more preferably 85% by volume or less, and particularly preferably 80% by volume or less in 100% by volume of the non-aqueous solvent. By setting the upper limit in this way, it is possible to avoid a decrease in the electrical conductivity due to a decrease in the dielectric constant of the non-aqueous electrolyte solution, and it is easy to set the large current discharge characteristics of the non-aqueous electrolyte battery in a good range.

<Cyclic carboxylic acid ester>
The cyclic carboxylic acid ester preferably has 3 to 12 carbon atoms.
Specific examples thereof include gamma butyrolactone, gamma valerolactone, gamma caprolactone, and epsilon caprolactone. 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.

As the cyclic carboxylic acid ester, one kind may be used alone, and two kinds or more may be used in optional combination and ratio.
The compounding amount of the cyclic carboxylic acid ester is usually preferably 5% by volume or more, more preferably 10% by volume or more in 100% by volume of the non-aqueous solvent. Within this range, the electrical conductivity of the non-aqueous electrolyte solution is improved, and the large-current discharge characteristics of the non-aqueous electrolyte battery are easily improved. The amount of the cyclic carboxylic acid ester compounded is preferably 50% by volume or less, more preferably 40% by volume or less. By setting the upper limit in this way, the viscosity of the non-aqueous electrolytic solution is set to an appropriate range, the decrease of the electrical conductivity is avoided, the increase of the negative electrode resistance is suppressed, and the large current discharge of the non-aqueous electrolytic solution secondary battery is suppressed. It is easy to set the characteristics in a good range.

<Ether compound>
As the ether compound, a chain ether having 3 to 10 carbon atoms and a cyclic ether having 3 to 6 carbon atoms in which a part of hydrogen may be replaced by fluorine is preferable.
As the chain ether having 3 to 10 carbon atoms,
Diethyl ether, di (2-fluoroethyl) ether, di (2,2-difluoroethyl) ether, di (2,2,2-trifluoroethyl) ether, ethyl (2-fluoroethyl) ether, ethyl (2,2 2,2-trifluoroethyl) ether, ethyl (1,1,2,2-tetrafluoroethyl) ether, (2-fluoroethyl) (2,2,2-trifluoroethyl) ether, (2-fluoroethyl) ) (1,1,2,2-Tetrafluoroethyl) ether, (2,2,2-trifluoroethyl) (1,1,2,2-tetrafluoroethyl) ether, ethyl-n-propyl ether, ethyl (3-Fluoro-n-propyl) ether, ethyl (3,3,3-trifluoro-n-propyl) ether, ethyl (2,2,3,3-teto) Fluoro-n-propyl) ether, ethyl (2,2,3,3,3-pentafluoro-n-propyl) ether, 2-fluoroethyl-n-propyl ether, (2-fluoroethyl) (3-fluoro- n-propyl) ether, (2-fluoroethyl) (3,3,3-trifluoro-n-propyl) ether, (2-fluoroethyl) (2,2,3,3-tetrafluoro-n-propyl) Ether, (2-fluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, 2,2,2-trifluoroethyl-n-propyl ether, (2,2,2- Trifluoroethyl) (3-fluoro-n-propyl) ether, (2,2,2-trifluoroethyl) (3,3,3-trifluoro-n-propyl) ether, (2,2 , 2-Trifluoroethyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (2,2,2-trifluoroethyl) (2,2,3,3,3-pentafluoro- n-propyl) ether, 1,1,2,2-tetrafluoroethyl-n-propyl ether, (1,1,2,2-tetrafluoroethyl) (3-fluoro-n-propyl) ether, (1, 1,2,2-tetrafluoroethyl) (3,3,3-trifluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethyl) (2,2,3,3-tetrafluoro -N-propyl) ether, (1,1,2,2-tetrafluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di-n-propyl ether, (n- Propyl) (3-fluor (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- Trafluoro-n-propyl) ether, (3,3,3-trifluoro-n-propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di (2,2,3) , 3-Tetrafluoro-n-propyl) ether, (2,2,3,3-tetrafluoro-n-propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di ( 2,2,3,3,3-pentafluoro-n-propyl) ether, di-n-butyl ether, dimethoxymethane, methoxyethoxymethane, methoxy (2-fluoroethoxy) methane, methoxy (2,2,2-tri) Fluoroethoxy) methane methoxy (1,1,2,2-tetrafluoroethoxy) methane, diethoxymethane, ethoxy (2-fluoroethoxy) methane, ethoxy (2,2 2-trifluoroethoxy) methane, ethoxy (1,1,2,2-tetrafluoroethoxy) methane, di (2-fluoroethoxy) methane, (2-fluoroethoxy) (2,2,2-trifluoroethoxy) Methane, (2-fluoroethoxy) (1,1,2,2-tetrafluoroethoxy) methanedi (2,2,2-trifluoroethoxy) methane, (2,2,2-trifluoroethoxy) (1,1 , 2,2-Tetrafluoroethoxy) methane, di (1,1,2,2-tetrafluoroethoxy) methane, dimethoxyethane, methoxyethoxyethane, methoxy (2-fluoroethoxy) ethane, methoxy (2,2,2 -Trifluoroethoxy) ethane, methoxy (1,1,2,2-tetrafluoroethoxy) ethane, diethoxyethane, ethoxy Si (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, di (1,1,2,2-tetrafluoroethoxy) ethane, ethylene glycol di-n- Examples include propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether, and the like.

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 them, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether have high solvation ability to lithium ions and improve ionic dissociation. From the viewpoint, it is preferable to use dimethoxymethane, diethoxymethane, and ethoxymethoxymethane since they have low viscosity and high ionic conductivity.

The ether compounds may be used alone or in any combination of two or more at any ratio.
The content of the ether compound is usually 5% by volume or more, more preferably 10% by volume or more, further preferably 15% by volume or more, and preferably 70% by volume or less in 100% by volume of the non-aqueous solvent. It is more preferably 60% by volume or less, and further preferably 50% by volume or less.

Within this range, it is easy to secure the effect of improving the lithium ion dissociation degree of the chain ether and the ionic conductivity resulting from the decrease in viscosity, and when the negative electrode active material is a carbonaceous material, the chain ether together with the lithium ion It is easy to avoid the situation where capacity is reduced due to co-insertion.
<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.

As the cyclic sulfone having 3 to 6 carbon atoms,
Trimethylene sulfones, tetramethylene sulfones, hexamethylene sulfones which are monosulfone compounds;
Examples thereof include trimethylenedisulfones, tetramethylenedisulfones, and hexamethylenedisulfones, which are disulfone compounds.

Among them, tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones, and hexamethylene disulfones are more preferable, and tetramethylene sulfones (sulfolanes) are particularly preferable, from the viewpoint of dielectric constant and viscosity.
As 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-methyl Sulfolane, 4-fluoro-2-methylsulfolane, 5-fluoro-3-methylsulfolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane, 3-fluoromethylsulfolane, 2-difluoromethylsulfolane, 3-difluoro Methylsulfolane, 2- Lifluoromethylsulfolane, 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 they have high ionic conductivity and high input / output characteristics.

Further, as the chain sulfone having 2 to 6 carbon atoms,
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, pentafluoro Ethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, perf Oroethyl methyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di (trifluoroethyl) sulfone, perfluorodiethyl sulfone, fluoromethyl-n-propyl sulfone, difluoromethyl-n-propyl sulfone, trifluoromethyl- n-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-n-butyl sulfone, trifluoroethyl-t-butyl sulfone, pentafluoroethyl- - butyl sulfone, pentafluoroethyl -t- butyl sulfone, and the like.

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

The sulfone compounds may be used alone or in any combination of two or more at any ratio.
The blending amount of the sulfone compound is usually 0.3% by volume or more, more preferably 1% by volume or more, further preferably 5% by volume or more, and preferably 40% in 100% by volume of the non-aqueous solvent. It is preferably not more than 35% by volume, more preferably not more than 30% by volume.
Within this range, the effect of improving durability such as cycle characteristics and storage characteristics can be easily obtained, and the viscosity of the non-aqueous electrolyte solution can be set in an appropriate range to prevent a decrease in electric conductivity. When charging / discharging an aqueous electrolyte battery at a high current density, it is easy to avoid a situation where the charge / discharge capacity retention rate decreases.

<When using a cyclic carbonate having a fluorine atom as a non-aqueous solvent>
The cyclic carbonate having a fluorine atom can be used as a 1-2-2. As shown in, it can be used as an auxiliary agent and also as a non-aqueous solvent.
In the present invention, when a cyclic carbonate having a fluorine atom is used as a non-aqueous solvent, as the non-aqueous solvent other than the cyclic carbonate having a fluorine atom, one of the above-exemplified non-aqueous solvents is combined with a cyclic carbonate having a fluorine atom. Or two or more of them may be used in combination with a cyclic carbonate having a fluorine atom.

  For example, one preferable combination of non-aqueous solvents is a combination mainly composed of a cyclic carbonate having a fluorine atom and a chain carbonate. Among them, the total of the cyclic carbonate having a fluorine atom and the chain carbonate in the non-aqueous solvent is preferably 60% by volume or more, more preferably 80% by volume or more, further preferably 90% by volume or more, and a fluorine atom. The ratio of the cyclic carbonate having a fluorine atom to the total of the cyclic carbonate having a chain carbonate and the chain carbonate is 3% by volume or more, preferably 5% by volume or more, more preferably 10% by volume or more, further preferably 15% by volume or more. Further, it is usually 60% by volume or less, preferably 50% by volume or less, more preferably 40% by volume or less, further preferably 35% by volume or less, particularly preferably 30% by volume or less, and most preferably 20% by volume or less.

When a combination of these non-aqueous solvents is used, the cycle characteristics and high temperature storage characteristics (in particular, the remaining capacity after high temperature storage and the high load discharge capacity) of the battery produced using the combination may be well balanced.
For example, as a specific example of a preferable combination of a cyclic carbonate having a fluorine atom and a chain carbonate,
Monofluoroethylene carbonate and dimethyl carbonate, monofluoroethylene carbonate and diethyl carbonate, monofluoroethylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and dimethyl carbonate and diethyl carbonate, monofluoroethylene carbonate and dimethyl carbonate and ethyl methyl carbonate, monofluoro Examples thereof include ethylene carbonate, diethyl carbonate, ethyl methyl carbonate, monofluoroethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.

  Among the combinations of cyclic carbonates having a fluorine atom and chain carbonates, those containing symmetrical chain alkyl carbonates as chain carbonates are more preferable, and especially monofluoroethylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monocarbonate. Cycle characteristics that include monofluoroethylene carbonate, symmetric chain carbonates and asymmetric chain carbonates such as fluoroethylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate It is preferable since it has a good balance of high current discharge characteristics. Among them, the symmetric chain carbonate is preferably dimethyl carbonate, and the alkyl group of the chain carbonate preferably has 1 to 2 carbon atoms.

  A preferable combination is a combination of a cyclic carbonate having a fluorine atom and a chain carbonate, and a cyclic carbonate having no fluorine atom. Among them, the total of the cyclic carbonate having a fluorine atom and the cyclic carbonate having no fluorine atom in the non-aqueous solvent is preferably 10% by volume or more, more preferably 15% by volume or more, further preferably 20% by volume or more. And the ratio of the cyclic carbonate having a fluorine atom to the total of the cyclic carbonate having a fluorine atom and the cyclic carbonate having no fluorine atom is 1% by volume or more, preferably 3% by volume or more, more preferably 5% by volume or more. , More preferably 10% by volume or more, particularly preferably 20% by volume or more, preferably 95% by volume or less, more preferably 85% by volume or less, further preferably 75% by volume or less, particularly preferably 60% by volume. It is as follows.

When the cyclic carbonate containing no fluorine atom is contained in this concentration range, the electric conductivity of the electrolytic solution can be maintained while forming a stable protective film on the negative electrode.
Specific examples of preferred combinations of a cyclic carbonate having a fluorine atom, a cyclic carbonate having no fluorine atom, and a chain carbonate include:
Monofluoroethylene carbonate and ethylene carbonate and dimethyl carbonate, monofluoroethylene carbonate and ethylene carbonate and diethyl carbonate, monofluoroethylene carbonate and ethylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and ethylene carbonate and dimethyl carbonate and diethyl carbonate, monofluoro Ethylene carbonate, ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate G, monofluoroethylene carbonate, propylene carbonate and dimethyl carbonate, monofluoroethylene carbonate, propylene carbonate and diethyl carbonate, monofluoroethylene carbonate, propylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate, Monofluoroethylene carbonate, propylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, propylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate Cylmethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate and dimethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate and diethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate and ethyl methyl carbonate, monofluoroethylene Carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate and propylene carbonate Examples include diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.

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

  When ethyl methyl carbonate is contained in the non-aqueous solvent, the proportion of ethyl methyl carbonate in the total non-aqueous solvent is preferably 10% by volume or more, more preferably 20% by volume or more, further preferably 25% by volume or more. , Particularly preferably 30% by volume or more, preferably 95% by volume or less, more preferably 90% by volume or less, further preferably 85% by volume or less, particularly preferably 80% by volume or less. The load characteristics of the battery may be improved.

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

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

  Among them, the total of the cyclic carbonate having no fluorine atom and the chain carbonate in the non-aqueous solvent is preferably 70% by volume or more, more preferably 80% by volume or more, further preferably 90% by volume or more, and The ratio of the cyclic carbonate having no fluorine atom to the total of the cyclic carbonate and the chain carbonate is preferably 5% by volume or more, more preferably 10% by volume or more, further preferably 15% by volume or more, and preferably It is 50% by volume or less, more preferably 35% by volume or less, further preferably 30% by volume or less, and particularly preferably 25% by volume or less.

When a combination of these non-aqueous solvents is used, the cycle characteristics and high temperature storage characteristics (in particular, the remaining capacity after high temperature storage and the high load discharge capacity) of the battery produced using the combination may be well balanced.
For example, as a specific example of a preferable combination of a cyclic carbonate having no fluorine atom and a chain carbonate,
Ethylene carbonate and dimethyl carbonate, ethylene carbonate and diethyl carbonate, ethylene carbonate and ethyl methyl carbonate, ethylene carbonate and dimethyl carbonate and diethyl carbonate, ethylene carbonate and dimethyl carbonate and ethyl methyl carbonate, ethylene carbonate and diethyl carbonate and ethyl methyl carbonate, ethylene carbonate And dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, propylene carbonate and ethyl methyl carbonate, propylene carbonate and ethyl methyl carbonate and diethyl carbonate, propylene carbonate and ethyl methyl carbonate and dimethyl carbonate.

  Among the combinations of cyclic carbonates having no fluorine atom and chain carbonates, those containing asymmetric chain alkyl carbonates as chain carbonates are more preferable, and particularly ethylene carbonate and ethyl methyl carbonate, propylene carbonate and ethyl. Cycle characteristics and large current such as methyl carbonate, ethylene carbonate and ethyl methyl carbonate and dimethyl carbonate, ethylene carbonate and ethyl methyl carbonate and diethyl carbonate, propylene carbonate and ethyl methyl carbonate and dimethyl carbonate, propylene carbonate and ethyl methyl carbonate and diethyl carbonate. It is preferable because the discharge characteristics are well balanced.

Among them, the asymmetric chain carbonate is preferably ethylmethyl carbonate, and the alkyl group of the chain carbonate preferably has 1 to 2 carbon atoms.
When dimethyl carbonate is contained in the non-aqueous solvent, the proportion of dimethyl carbonate in the total non-aqueous solvent is preferably 10% by volume or more, more preferably 20% by volume or more, further preferably 25% by volume or more, and particularly It is preferably 30% by volume or more, preferably 90% by volume or less, more preferably 80% by volume or less, further preferably 75% by volume or less, particularly preferably 70% by volume or less, The load characteristics of the battery may be improved.

Among them, containing dimethyl carbonate and ethyl methyl carbonate, by increasing the content ratio of dimethyl carbonate than the content ratio of ethyl methyl carbonate, while maintaining the electrical conductivity of the electrolytic solution, the battery characteristics after high temperature storage is improved. May occur and is preferable.
The volume ratio of dimethyl carbonate to ethyl methyl carbonate in all non-aqueous solvents (dimethyl carbonate / ethyl methyl carbonate) is 1.1 or more in terms of improving the electric conductivity of the electrolytic solution and the battery characteristics after storage. Is preferable, 1.5 or more is more preferable, and 2.5 or more is further preferable. From the viewpoint of improving battery characteristics, the volume ratio (dimethyl carbonate / ethyl methyl carbonate) is preferably 40 or less, more preferably 20 or less, further preferably 10 or less, and particularly preferably 8 or less.

In the combination mainly composed of a cyclic carbonate having no fluorine atom and a chain carbonate, cyclic carboxylic acid esters, chain carboxylic acid esters, cyclic ethers, chain ethers, sulfur-containing organic solvent, phosphorus-containing Other solvents such as an organic solvent and an aromatic fluorine-containing solvent may be mixed.
In addition, in this specification, the volume of the non-aqueous solvent is a measured value at 25 ° C., but a solid substance such as ethylene carbonate at 25 ° C. uses a measured value at a melting point.

1-5. Auxiliary agent In the non-aqueous electrolyte battery of the present invention, a compound represented by the general formula (A), a cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, a nitrile compound, an isocyanate compound, isocyanuric In addition to the compound having an acid skeleton, the fluorophosphate salt, the fluorosulfonate salt, and the cyclic sulfonate ester, an auxiliary agent may be appropriately used depending on the purpose. Examples of the auxiliaries include acid anhydride compounds, fluorinated unsaturated cyclic carbonates, compounds having a triple bond, and other auxiliaries shown below.

1-5-1. Acid anhydride compound As the acid anhydride compound, a carboxylic acid anhydride, a sulfuric acid anhydride, a nitric acid anhydride, a sulfonic acid anhydride, a phosphoric acid anhydride, a phosphorous acid anhydride, or a cyclic acid anhydride, a chain The structure is not particularly limited as long as it is an acid anhydride compound and is not particularly limited as long as it is an acid anhydride.

Specific examples of the acid anhydride compound include, for example,
Malonic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, maleic anhydride, citraconic anhydride, 2,3-dimethylmaleic anhydride, glutaconic anhydride, itaconic anhydride, phthalic anhydride, phenylmaleic anhydride 2,3-diphenylmaleic anhydride, cyclohexane-1,2-dicarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, 4 , 4'-oxydiphthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, phenylsuccinic anhydride, 2-phenylglutaric anhydride , Allyl succinic anhydride, 2-buten-11-yl succinic anhydride, (2-methyl-2-propenyl) succinic anhydride, tetra Fluorosuccinic anhydride, diacetyl-tartaric anhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5- (2,5-dioxo Tetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, methacrylic acid anhydride, acrylic acid anhydride, crotonic acid anhydride, methanesulfonic acid anhydride, trifluoromethanesulfonic acid anhydride, nona Fluorobutane sulfonic anhydride, acetic anhydride and the like can be mentioned.

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

As the acid anhydride compound, one kind may be used alone, and two kinds or more may be used in optional combination and ratio.
There is no limitation on the amount of the acid anhydride compound compounded 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 usually 0.001 with respect to the non-aqueous electrolyte solution of the present invention. Mass% or more, preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and usually 10 mass% or less, preferably 5 mass% or less, more preferably 3 mass% or less, and further preferably 2 It is contained at a concentration of not more than mass%, particularly preferably not more than 1 mass%, most preferably not more than 0.5 mass%.
When the above range is satisfied, the effects such as output characteristics, load characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-5-2. Fluorinated Unsaturated Cyclic Carbonate As the fluorinated cyclic carbonate, it is also preferable to use a cyclic carbonate having an unsaturated bond and a fluorine atom (hereinafter sometimes referred to as “fluorinated unsaturated cyclic carbonate”). The number of fluorine atoms contained in the fluorinated unsaturated cyclic carbonate is not particularly limited as long as it is 1 or more. Among them, the number of fluorine atoms is usually 6 or less, preferably 4 or less, and 1 or 2 is most preferable.

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

As the fluorinated ethylene carbonate derivative substituted with a substituent having an aromatic ring or a carbon-carbon double bond,
4-fluoro-4-vinyl ethylene carbonate, 4-fluoro-4-allyl ethylene carbonate, 4-fluoro-5-vinyl ethylene carbonate, 4-fluoro-5-allyl ethylene carbonate, 4,4-difluoro-4-vinyl ethylene Carbonate, 4,5-difluoro-4-allylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4,5-difluoro-4-allylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4-fluoro-4,5-diallyl ethylene carbonate, 4,5-difluoro-4,5-divinyl ethylene carbonate, 4,5-difluoro-4,5-diallyl ethylene carbonate, 4-fluoro-4-phenylethylene carbonate, 4-F Oro-5-phenylethylene carbonate, 4,4-difluoro-5-phenylethylene carbonate, 4,5-difluoro-4-phenylethylene carbonate.

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

The molecular weight of the fluorinated unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. The molecular weight is preferably 50 or more and 250 or less. Within this range, the solubility of the fluorinated cyclic carbonate in the non-aqueous electrolyte solution can be easily ensured and the effect of the present invention can be easily exhibited.
The method for producing the fluorinated unsaturated cyclic carbonate is not particularly limited, and a known method can be arbitrarily selected and produced. The molecular weight is more preferably 100 or more, and more preferably 200 or less.

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. The amount of the fluorinated unsaturated cyclic carbonate compounded is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired.
The content of the fluorinated unsaturated cyclic carbonate is usually 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.5% by mass or more, in 100% by mass of the non-aqueous electrolyte solution. It is preferably 10% by mass or less, more preferably 5% by mass or less, further preferably 3% by mass or less, and particularly preferably 2% by mass or less.
Within this range, the non-aqueous electrolyte battery is likely to exhibit a sufficient effect of improving cycle characteristics, the high temperature storage characteristics are deteriorated, the amount of gas generated is increased, and the discharge capacity maintenance ratio is decreased. Easy to avoid.

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

2-propynyl methyl carbonate, 2-propynyl ethyl carbonate, 2-propynyl propyl carbonate, 2-propynyl butyl carbonate, 2-propynyl phenyl carbonate, 2-propynyl cyclohexyl carbonate, di-2-propynyl carbonate, 1-methyl-2-propynyl Methyl carbonate, 1,1-dimethyl-2-propynyl methyl carbonate, 2-butynyl methyl carbonate, 3-butynyl methyl carbonate, 2-pentynyl methyl carbonate, 3-pentynyl methyl carbonate, 4-pentynyl methyl carbonate, etc. 2-butyne-1,4-diol dimethyldicarbonate, 2-butyne-1,4-diol diethyldicarbonate, 2-butyne-1,4-diol Dicarbonates such as dipropyl dicarbonate, 2-butyne-1,4-diol dibutyl dicarbonate, 2-butyne-1,4-diol diphenyl dicarbonate and 2-butyne-1,4-diol dicyclohexyl dicarbonate;

  2-propynyl acetate, 2-propynyl propionate, 2-propynyl butyrate, 2-propynyl benzoate, 2-propynyl cyclohexylcarboxylate, 1,1-dimethyl-2-propynyl acetate, 1,1-dimethyl-2-propionate. Propinyl, butyric acid 1,1-dimethyl-2-propynyl, benzoic acid 1,1-dimethyl-2-propynyl, cyclohexylcarboxylic acid 1,1-dimethyl-2-propynyl, 2-butynyl acetate, 3-butynyl acetate, acetic acid 2 -Pentynyl, 3-pentynyl acetate, 4-pentynyl acetate, methyl acrylate, ethyl acrylate, propyl acrylate, vinyl acrylate, 2-propenyl acrylate, 2-butenyl acrylate, 3-butenyl acrylate, methyl methacrylate , Ethyl methacrylate, propyl methacrylate, metac Vinyl acetate, 2-propenyl methacrylate, 2-butenyl methacrylate, 3-butenyl methacrylate, methyl 2-propynate, ethyl 2-propynate, propyl 2-propynate, vinyl 2-propynate, 2-propynoic acid. 2-propenyl, 2-butenyl 2-propynate, 3-butenyl 2-propynate, methyl 2-butyrate, ethyl 2-butyrate, propyl 2-butyrate, vinyl 2-butyrate, 2-butyric acid 2- Propenyl, 2-butenyl 2-butyrate, 3-butenyl 2-butyrate, methyl 3-butyrate, ethyl 3-butyrate, propyl 3-butyrate, vinyl 3-butyrate, 2-propenyl 3-butyrate, 2-Butenyl 3-butyrate, 3-butenyl 3-butyrate, methyl 2-pentate, ethyl 2-pentate, propyl 2-pentate, 2- Vinyl pentanate, 2-propenyl 2-pentate, 2-butenyl 2-pentate, 3-butenyl 2-pentate, methyl 3-pentate, ethyl 3-pentate, propyl 3-pentate, 3-pentynoate Vinyl, 2-propenyl 3-pentate, 2-butenyl 3-pentate, 3-butenyl 3-pentate, methyl 4-pentate, ethyl 4-pentate, propyl 4-pentate, vinyl 4-pentate, Monocarboxylic acid esters such as 2-propenyl 4-pentate, 2-butenyl 4-pentate, 3-butenyl 4-pentate;

2-butyne-1,4-diol diacetate, 2-butyne-1,4-diol dipropionate, 2-butyne-1,4-diol dibutyrate, 2-butyne-1,4-diol dibenzoate, 2-butyne Dicarboxylic acid ester such as -1,4-diol dicyclohexanecarboxylate;
Methyl 2-propynyl oxalate, ethyl 2-propynyl oxalate, propyl 2-propynyl oxalate, 2-propynyl vinyl oxalate, allyl 2-propynyl oxalate, di-2-propynyl oxalate, 2-butynyl methyl oxalate, 2-butynyl ethyl oxalate, 2-butynylpropyl oxalate, 2-butynyl vinyl oxalate, allyl 2-butynyl oxalate, di-2-butynyl oxalate, 3-butynyl methyl oxalate, 3-butynyl ethyl oxalate. , 3-butynylpropyl oxalate, 3-butynyl oxalate

Oxalic acid diesters such as vinyl, allyl-3-butynyl oxalate, and di-3-butynyl oxalate;
Methyl (2-propynyl) (vinyl) phosphine oxide, divinyl (2-propynyl) phosphine oxide, di (2-propynyl) (vinyl) phosphine oxide, di (2-propenyl) 2 (-propynyl) phosphine oxide, di (2 A phosphine oxide such as -propynyl) (2-propenyl) phosphine oxide, di (3-butenyl) (2-propynyl) phosphine oxide, and di (2-propynyl) (3-butenyl) phosphine oxide;

2-propynyl methyl (2-propenyl) phosphinate, 2-propynyl 2-butenyl (methyl) phosphinate, 2-propynyl di (2-propenyl) phosphinate, 2-propynyl di (3-butenyl) phosphinate, methyl ( 2-propenyl) phosphinic acid 1,1-dimethyl-2-propynyl, 2-butenyl (methyl) phosphinic acid 1,1-dimethyl-2-propynyl, di (2-propenyl) phosphinic acid 1,1-dimethyl-2- Propinyl and 1,1-dimethyl-2-propynyl di (3-butenyl) phosphinate, 2-propenyl methyl (2-propynyl) phosphinate, 3-butenyl methyl (2-propynyl) phosphinate, di (2-propynyl) ) 2-Propenyl phosphinate, 3-butenyl di (2-propynyl) phosphinate, 2 Propynyl (2-propenyl) phosphinic acid 2-propenyl, and 2-propynyl (2-propenyl) phosphinic acid 3-phosphinic acid esters butenyl;

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

Phosphoric acid (methyl) (2-propenyl) (2-propynyl), phosphoric acid (ethyl) (2-propenyl) (2-propynyl), phosphoric acid (2-butenyl) (methyl) (2-propynyl), phosphoric acid (2-butenyl) (ethyl) (2-propynyl), phosphoric acid (1,1-dimethyl-2-propynyl) (methyl) (2-propenyl), phosphoric acid (1,1-dimethyl-2-propynyl) ( Ethyl) (2-propenyl), phosphoric acid (2-butenyl) (1,1-dimethyl-2-propynyl) (methyl), and phosphoric acid (2-butenyl) (ethyl) (1,1-dimethyl-2- A phosphoric acid ester such as propynyl);
Of these, compounds having an alkynyloxy group are preferable because they form the negative electrode coating more stably in the electrolytic solution.

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

  The compound having a triple bond may be used alone or in any combination of two or more in any ratio. The compounding amount of the compound having a triple bond with respect to the whole 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. Containing at a concentration of 01 mass% or more, preferably 0.05 mass% or more, more preferably 0.1 mass% or more, and usually 5 mass% or less, preferably 3 mass% or less, more preferably 1 mass% or less. Let When the above range is satisfied, the effects such as output characteristics, load characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-5-4. Other auxiliaries As other auxiliaries, known auxiliaries other than the above auxiliaries can be used. Other auxiliary agents include
Carbonate compounds such as erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl-methyl carbonate;
Spiro compounds such as 2,4,8,10-tetraoxaspiro [5.5] undecane and 3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane;
Ethylene sulfite, methyl fluorosulfonate, ethyl fluorosulfonate, methyl methanesulfonate, ethyl methanesulfonate, busulfan, sulfolene, diphenyl sulfone, N, N-dimethylmethanesulfonamide, N, N-diethylmethanesulfonamide, vinyl Methyl sulfonate, ethyl vinyl sulfonate, allyl vinyl sulfonate, propargyl vinyl sulfonate, methyl allyl sulfonate, ethyl allyl sulfonate, allyl sulfonate allyl sulfonate, propargyl allyl sulfonate, 1,2-bis (vinylsulfonyloxy) Sulfur-containing compounds such as ethane;

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

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

The amount of the other auxiliary compounded is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. Other auxiliaries are preferably 0.01% by mass or more and 5% by mass or less in 100% by mass of the non-aqueous electrolyte solution. Within this range, the effects of the other auxiliaries are likely to be sufficiently exhibited, and it is easy to avoid a situation in which the characteristics of the battery such as the high load discharge characteristics are deteriorated.
As described above, the above-mentioned non-aqueous electrolyte solution also includes those present inside the non-aqueous electrolyte battery according to 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, and a non-aqueous electrolytic solution is prepared from a substantially isolated one, by the method described below. Non-aqueous electrolyte solution obtained by injecting into a separately assembled battery, or if the non-aqueous electrolyte solution in the battery is, or if the components of the non-aqueous electrolyte solution of the present invention are separately put in the battery, When the same composition as the non-aqueous electrolyte solution of the present invention is obtained by mixing in, the compound constituting the non-aqueous electrolyte solution of the present invention is further generated in the non-aqueous electrolyte battery to give the non-aqueous electrolyte solution of the present invention. The case where the same composition as the aqueous electrolytic solution is obtained is also included.

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

2-1. Negative Electrode The negative electrode active material used for the negative electrode will be described below. The negative electrode active material is not particularly limited as long as it can electrochemically store and release lithium ions. Specific examples include carbonaceous materials, alloy-based materials, lithium-containing metal composite oxide materials, and the like. These may be used alone or in any combination of two or more.

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

(1) Examples of the natural graphite include scaly graphite, scaly graphite, soil graphite, and / or graphite particles obtained by subjecting these graphites to a raw material and subjected to treatments such as spheroidization and densification. Among these, spherical or ellipsoidal graphite subjected to spheroidizing treatment is particularly preferable from the viewpoint of particle filling properties and charge / discharge rate characteristics.
As an apparatus used for the spheroidizing treatment, for example, an apparatus which repeatedly applies mechanical action such as compression, friction, shearing force, etc. including impact of particles mainly to impact force to particles can be used.

Specifically, it has a rotor with many blades installed inside the casing, and the high-speed rotation of the rotor causes mechanical action such as impact compression, friction, and shearing force on the carbon material introduced inside. Is preferable to perform the spheroidizing treatment. Further, it is preferable that the carbon material has a mechanism for repeatedly giving a mechanical action by circulating the carbon material.
For example, when spheroidizing treatment is performed using the above-mentioned device, the peripheral speed of the rotating rotor is preferably 30 to 100 m / sec, more preferably 40 to 100 m / sec, and 50 to 100 m / sec. More preferably. Further, the treatment is possible by simply passing the carbonaceous material, but it is preferable to circulate or stay in the device for 30 seconds or more, and it is preferable to circulate or stay in the device for 1 minute or more. More preferable.

  (2) Examples of artificial graphite include coal tar pitch, coal-based heavy oil, atmospheric residual oil, petroleum-based heavy oil, aromatic hydrocarbons, nitrogen-containing cyclic compounds, sulfur-containing cyclic compounds, polyphenylene, polyvinyl chloride, Organic compounds such as polyvinyl alcohol, polyacrylonitrile, polyvinyl butyral, natural polymers, polyphenylene sulfide, polyphenylene oxide, furfuryl alcohol resin, phenol-formaldehyde resin, and imide resin are usually used in the range of 2500 ° C or higher and usually 3200 ° C or lower. Examples thereof include those produced by graphitizing at a temperature and optionally crushing and / or classifying. At this time, a silicon-containing compound, a boron-containing compound or the like can be used as the graphitization catalyst. In addition, artificial graphite obtained by graphitizing mesocarbon microbeads separated in the heat treatment process of pitch can be mentioned. Further, artificial graphite, which is a granulated particle composed of primary particles, can also be used. For example, by mixing graphitizable carbonaceous material powder such as mesocarbon microbeads or coke with a graphitizable catalyst such as tar and pitch and a graphitizing catalyst, graphitizing, and crushing as necessary. An example of the obtained graphite particles is a plurality of flat particles, which are aggregated or combined so that the orientation planes are not parallel to each other.

  (3) As the amorphous carbon, a graphitizable carbon precursor such as tar or pitch is used as a raw material, and the amorphous carbon is heat-treated one or more times in a non-graphitizing temperature region (range of 400 to 2200 ° C.). Examples thereof include particles and amorphous carbon particles obtained by heat treatment using a non-graphitizable carbon precursor such as a resin as a raw material.

(4) The carbon-coated graphite can be obtained by mixing natural graphite and / or artificial graphite with a carbon precursor, which is an organic compound such as tar, pitch or resin, and heat treating it once or more in the range of 400 to 2300 ° C. A carbon-graphite composite in which natural graphite and / or artificial graphite is used as nuclear graphite and amorphous carbon coats the nuclear graphite is exemplified. The composite form may cover the entire surface or a part of the surface, or may be a composite of a plurality of primary particles using carbon derived from the carbon precursor as a binder. It is also possible to deposit carbon (CVD) on the graphite surface by reacting natural graphite and / or artificial graphite with hydrocarbon gas such as benzene, toluene, methane, propane and aromatic volatiles at high temperature. It is also possible to obtain a graphite composite.

  (5) As the graphite-coated graphite, natural graphite and / or artificial graphite is mixed with a carbon precursor of a graphitizable organic compound such as tar, pitch or resin, and once in the range of about 2400 to 3200 ° C. Examples of the graphite-coated graphite in which natural graphite and / or artificial graphite obtained by the above heat treatment are used as nuclear graphite and the graphitized product coats the whole or a part of the surface of the nuclear graphite.

(6) As the resin-coated graphite, natural graphite and / or artificial graphite is mixed with resin and dried at a temperature of less than 400 ° C. to obtain natural graphite and / or artificial graphite as nuclear graphite, and the resin is nuclear graphite. Examples of the resin-coated graphite that coats
The carbonaceous materials (1) to (6) may be used alone or in any combination of two or more at any ratio.

  Examples of the organic compounds such as tar, pitch and resin used in the above (2) to (5) include coal-based heavy oil, direct-current heavy oil, cracked petroleum heavy oil, aromatic hydrocarbons, N-ring compounds. , S-ring compounds, polyphenylene, organic synthetic polymers, natural polymers, carbonizable organic compounds selected from the group consisting of thermoplastic resins and thermosetting resins. Further, the raw material organic compound may be dissolved in a low molecular weight organic solvent and used in order to adjust the viscosity at the time of mixing.

Moreover, as the natural graphite and / or the artificial graphite that is a raw material of the nuclear graphite, spheroidized natural graphite is preferable.
As the alloy-based material used as the negative electrode active material, as long as lithium can be occluded and released, elemental lithium, elemental metals and alloys forming a lithium alloy, or oxides, carbides, nitrides, silicides, and sulfides thereof. It may be any of compounds such as compounds and phosphides, and is not particularly limited. The elemental metal or alloy forming the lithium alloy is preferably a material containing a metal / metalloid element of group 13 and group 14 (that is, excluding carbon), more preferably an elemental metal of aluminum, silicon and tin, and An alloy or compound containing these atoms. These may be used alone or in any combination of two or more at any ratio.

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

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

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

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

If the Raman R value is less than the above range, the crystallinity of the particle surface may be too high, and the number of sites where Li enters between layers may decrease with charge and discharge. That is, charge acceptability may decrease. In addition, when the negative electrode is densified by pressing after applying it to the current collector, crystals are likely to be oriented in the direction parallel to the electrode plate, which may cause deterioration of load characteristics.
On the other hand, when the amount exceeds the above range, the crystallinity of the particle surface may be lowered, the reactivity with the non-aqueous electrolyte solution may be increased, and the efficiency may be lowered and the gas generation may be increased.

  The Raman spectrum is measured by using a Raman spectroscope (for example, a Raman spectroscope manufactured by JASCO Corporation) to spontaneously drop and fill the sample into the measurement cell, and the sample surface in the cell is filled with argon ion laser light (or semiconductor). Laser beam) while rotating the cell in a plane perpendicular to the laser beam. For the obtained Raman spectrum, the intensity IA of the peak PA near 1580 cm −1 and the intensity IB of the peak PB near 1360 cm −1 are measured, and the intensity ratio R (R = IB / IA) is calculated. The Raman R value calculated by the measurement is defined as the Raman R value of the carbonaceous material of the present invention.

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

(BET specific surface area)
The BET specific surface area of the carbonaceous material is a value of the specific surface area measured using the BET method, and is usually 0.1 m 2 · g −1 or more, preferably 0.7 m 2 · g −1 or more, 1.0 m 2 · g g-1 or more is more preferable, 1.5 m2 · g-1 or more is particularly preferable, and usually 100 m2 · g-1 or less, 25 m2 · g-1 or less is preferable, and 15 m2 · g-1 or less is further preferable. It is particularly preferably 10 m2 · g-1 or less.

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

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

(Circularity)
When the circularity is measured as the spherical degree of the carbonaceous material, it is preferably within the following range. The circularity is defined as “circularity = (perimeter of equivalent circle having the same area as the particle projection shape) / (actual perimeter of particle projection shape)”, and theoretically when the circularity is 1. It becomes a true sphere.
The circularity of particles having a particle diameter of the carbonaceous material in the range of 3 to 40 μm is preferably close to 1, and is preferably 0.1 or more, more preferably 0.5 or more, and more preferably 0.8 or more. 0.85 or more is more preferable, and 0.9 or more is particularly preferable. The high current density charge / discharge characteristics improve as the circularity increases. Therefore, if the circularity is less than the above range, the filling property of the negative electrode active material may decrease, the resistance between particles may increase, and the high-current-density charge / discharge characteristics may deteriorate for a short time.

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

  The method of improving the circularity is not particularly limited, but a spherical shape obtained by subjecting to a spherical shape is preferable because the shape of interparticle voids in the electrode body is adjusted. Examples of the spheroidizing treatment include a method of mechanically approximating a spherical shape by applying a shearing force or a compressing force, a mechanical / physical treatment method of granulating a plurality of fine particles by a binder or the adhesive force of the particles themselves, etc. Is mentioned.

(Tap density)
The tap density of the carbonaceous material is usually 0.1 g · cm −3 or more, preferably 0.5 g · cm −3 or more, more preferably 0.7 g · cm −3 or more, and 1 g · cm −3 or more. It is particularly preferable, 2 g · cm −3 or less is preferable, 1.8 g · cm −3 or less is further preferable, and 1.6 g · cm −3 or less is particularly preferable. When the tap density is less than the above range, the packing density is difficult to increase when used as a negative electrode, and it may not be possible to obtain a high capacity battery. On the other hand, when the amount exceeds the above range, voids between particles in the electrode become too small, it becomes difficult to secure conductivity between particles, and it may be difficult to obtain preferable battery characteristics.

  The tap density is measured by passing through a sieve with a mesh opening of 300 μm, dropping the sample into a tapping cell of 20 cm3 to fill the sample up to the upper end surface of the cell, and then measuring the powder density (for example, tap manufactured by Seishin Enterprise Co., Ltd. Tapping with a stroke length of 10 mm is performed 1000 times, and the tap density is calculated from the volume at that time and the mass of the sample.

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

  The orientation ratio is measured by X-ray diffraction after the sample is pressure-molded. A molded body obtained by filling 0.47 g of a sample in a molding machine having a diameter of 17 mm and compressing it with 58.8 MN · m-2 was set with clay so as to be flush with the surface of the sample holder for measurement. X-ray diffraction is measured. A ratio represented by (110) diffraction peak intensity / (004) diffraction peak intensity is calculated from the peak intensity of (110) diffraction and (004) diffraction of the obtained carbon.

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

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

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

(Coverage)
The negative electrode active material of the present invention may be coated with a carbonaceous material or a graphite material. Among them, the coating with an amorphous carbonaceous material is preferable from the viewpoint of lithium ion acceptance, and the coating rate is usually 0.5% or more and 30% or less, preferably 1% or more and 25% or less, and more preferably Is 2% or more and 20% or less. If this content is too large, the amount of amorphous carbon in the negative electrode active material increases, and the reversible capacity tends to decrease when the battery is assembled. If the content is too small, the amorphous carbon sites are not uniformly coated on the graphite particles serving as nuclei and strong granulation is not performed, and the particle size tends to be too small when pulverized after firing.

The content (coverage) of the carbide derived from the organic compound in the finally obtained negative electrode active material is the amount of the negative electrode active material, the amount of the organic compound, and the residue measured by the micro method according to JIS K 2270. It can be calculated by the following formula based on the coal rate.
Formula: Coverage rate (%) of carbide derived from organic compound = (mass of organic compound x residual carbon rate x 100) / {mass of negative electrode active material + (mass of organic compound x residual carbon rate)}

(Internal porosity)
The internal porosity of the negative electrode active material is usually 1% or more, preferably 3% or more, more preferably 5% or more, still more preferably 7% or more. Further, it is usually less than 50%, preferably 40% or less, more preferably 30% or less, still more preferably 20% or less. If this internal porosity is too small, the amount of liquid in the particles will be small, and the charge / discharge characteristics will tend to deteriorate.If the internal porosity is too large, the interparticle gap will be small when used as an electrode and the diffusion of the electrolyte solution will occur. Tends to be insufficient. In addition, the voids are filled with a substance such as amorphous carbon, a graphite material, a resin, etc. that buffers the expansion and contraction of the metal particles that can be alloyed with Li by existing in the voids or the voids being filled. May be.

<Metal particles capable of alloying with Li>
As a method for confirming that the metal particles are metal particles that can be alloyed with Li, identification of the metal particle phase by X-ray diffraction, observation of particle structure by electron microscope and elemental analysis, element by fluorescent X-ray Examples include analysis.
As the metal particles that can be alloyed with Li, any conventionally known metal particles can be used, but from the viewpoint of capacity and cycle life, the metal particles may be, for example, Fe, Co, Sb, Bi, Pb, Ni, Ag. , A metal selected from the group consisting of Si, Sn, Al, Zr, Cr, P, S, V, Mn, As, Nb, Mo, Cu, Zn, Ge, In, Ti and W, or a compound thereof. preferable. Further, an alloy composed of two or more kinds of metals may be used, and the metal particles may be alloy particles formed of two or more kinds of metal elements. Among these, a metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn and W or a metal compound thereof is preferable.

Examples of the metal compound include metal oxides, metal nitrides and metal carbides. Moreover, you may use the alloy which consists of 2 or more types of metals.
Among the metal particles capable of alloying with Li, Si or a Si metal compound is preferable. The Si metal compound is preferably a Si metal oxide. Si or a Si metal compound is preferable in terms of high capacity. In this specification, Si or Si metal compounds are collectively referred to as Si compounds. Specific examples of Si compounds include SiOx, SiNx, SiCx, and SiZxOy (Z = C, N). The Si compound is preferably a Si metal oxide, and the Si metal oxide is SiOx when represented by the general formula. This general formula SiOx is obtained by using Si dioxide (SiO2) and metallic Si (Si) as raw materials, and the value of x is usually 0 ≦ x <2. SiOx has a larger theoretical capacity than graphite, and further, amorphous Si or nano-sized Si crystals allow alkali ions such as lithium ions to easily come in and out, and a high capacity can be obtained.

  Specifically, the Si metal oxide is represented by SiOx, and x is 0 ≦ x <2, more preferably 0.2 or more and 1.8 or less, still more preferably 0. It is 4 or more and 1.6 or less, particularly preferably 0.6 or more and 1,4 or less, and X = 0 is particularly preferable. Within this range, the capacity is high, and at the same time, the irreversible capacity due to the combination of Li and oxygen can be reduced.

-Average particle size (d50) of metal particles that can be alloyed with Li
The average particle size (d50) of the metal particles that can be alloyed with Li is usually 0.01 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, still more preferably 0.3 μm, from the viewpoint of cycle life. It is above, usually 10 μm or less, preferably 9 μm or less, more preferably 8 μm or less. When the average particle diameter (d50) is within the above range, volume expansion due to charge / discharge is reduced, and good cycle characteristics can be obtained while maintaining charge / discharge capacity.

The average particle diameter (d50) is determined by a laser diffraction / scattering particle size distribution measuring method or the like.
-BET specific surface area of metal particles capable of alloying with Li The specific surface area of the metal particles capable of alloying with Li is usually 0.5 to 60 m2 / g by the BET method.
It is preferably from 1 to 40 m2 / g. When the specific surface area of the metal particles capable of alloying with Li by the BET method is within the above range, the charge and discharge efficiency and discharge capacity of the battery are high, lithium is rapidly taken in and out at high speed charge and discharge, and the rate characteristics are excellent, which is preferable.

-Amount of oxygen contained in metal particles that can be alloyed with Li The amount of oxygen contained in metal particles that can be alloyed with Li is not particularly limited, but is usually 0.01 to 8 mass% and 0.05 to 5 mass%. Preferably. The oxygen distribution state in the particles may exist near the surface, inside the particles, or even inside the particles, but it is particularly preferable that the oxygen distribution exists near the surface. When the amount of oxygen contained in the metal particles capable of alloying with Li is within the above range, the strong bond between Si and O suppresses volume expansion due to charge and discharge, and is excellent in cycle characteristics.

<Negative electrode active material containing metal particles capable of alloying with Li and graphite particles>.
The negative electrode active material containing the metal particles capable of alloying with Li and the graphite particles in the present invention may be a mixture in which the metal particles capable of alloying with Li and the graphite particles are mixed in the form of particles independent of each other. However, a composite in which metal particles capable of alloying with Li are present on the surface or inside of the graphite particles may be used. In the present specification, the composite (also referred to as composite particles) is not particularly limited as long as it is a particle containing metal particles and a carbonaceous material that can be alloyed with Li, but is preferably an alloy with Li. The metallizable particles and the carbonaceous material are particles integrated by physical and / or chemical bonding. As a more preferable form, a state in which each solid component is dispersed in the particles to the extent that the metal particles and carbonaceous material that can be alloyed with Li are present at least both on the surface of the composite particle and inside the bulk The carbonaceous material is present in order to integrate them by physical and / or chemical bonding. A more specific preferred form is a composite material comprising at least metal particles capable of alloying with Li and graphite particles, wherein the graphite particles, preferably natural graphite, have a folded structure having a curved surface. In the negative electrode active material, metal particles capable of being alloyed with Li are present in the gaps in the folded structure having the curved surface. In addition, the gap may be a void, and a substance such as amorphous carbon, a graphite material, or a resin that buffers the expansion and contraction of metal particles that can be alloyed with Li is present in the gap. Good.

Content ratio of Li-alloyable metal particles: The content ratio of Li-alloyable metal particles to the total of Li-alloyable metal particles and graphite particles is usually 0.1 mass% or more, preferably 1 It is at least mass%, more preferably at least 2 mass%, further preferably at least 3 mass%, and particularly preferably at least 5 mass%. Further, it is usually 99% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 30% by mass or less, still more preferably 25% by mass or less, still more preferably 20% by mass or less, particularly It is preferably 15% by mass or less, and most preferably 10% by mass or less. Within this range, a sufficient capacity can be obtained, which is preferable.

  The alloy-based material negative electrode can be manufactured by any known method. Specifically, as a method for producing a negative electrode, for example, a method in which a binder or a conductive material or the like is added to the above-described negative electrode active material and roll-formed as it is to form a sheet electrode, or compression-molded into a pellet electrode The above-mentioned negative electrode is usually formed on the current collector for the negative electrode (hereinafter sometimes referred to as “negative electrode current collector”) by a coating method, a vapor deposition method, a sputtering method, a plating method or the like. A method of forming a thin film layer (negative electrode active material layer) containing an active material is used. In this case, a binder, a thickener, a conductive material, a solvent and the like are added to the above-mentioned negative electrode active material to form a slurry, which is applied to the negative electrode current collector, dried, and then pressed to increase the density. A negative electrode active material layer is formed on the negative electrode current collector.

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

  In order to improve the binding effect with the negative electrode active material layer formed on the surface, it is preferable that the surface of these negative electrode current collectors be roughened in advance. As the surface roughening method, blasting, rolling with a rough surface roll, a machine for polishing the current collector surface with a wire brush equipped with abrasive cloth paper with abrasive particles fixed, grindstone, emery buff, steel wire, etc. Polishing method, electrolytic polishing method, chemical polishing method and the like.

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

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

  Examples of the conductive material used for the negative electrode include metal materials such as copper and nickel; carbon materials such as graphite and carbon black. These may be used alone or in any combination of two or more at any ratio. In particular, it is preferable to use a carbon material as the conductive material because the carbon material also acts as an active material. The content of the conductive material in the negative electrode material is usually 3% by mass or more, particularly 5% by mass or more, and usually 30% by mass or less, particularly preferably 25% by mass or less. If the content of the conductive material is too small, the conductivity tends to be insufficient, and if it is too large, the content of the negative electrode active material and the like is relatively insufficient, and the battery capacity and strength tend to be reduced. When two or more conductive materials are used together, the total amount of the conductive materials may be set within the above range.

  As the binder used for the negative electrode, any material can be used as long as it is a material that is safe for the solvent and the electrolytic solution used at the time of manufacturing the electrode. Examples thereof include polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, styrene / butadiene rubber / isoprene rubber, butadiene rubber, ethylene / acrylic acid copolymer, and ethylene / methacrylic acid copolymer. These may be used alone or in any combination of two or more at any ratio. The content of the binder is usually 0.5 parts by mass or more, particularly 1 part by mass or more, and usually 10 parts by mass or less, particularly preferably 8 parts by mass or less, relative to 100 parts by mass of the negative electrode material. If the content of the binder is too small, the strength of the obtained negative electrode tends to be insufficient, and if the content is too large, the content of the negative electrode active material and the like is relatively insufficient, so that the battery capacity and conductivity tend to be insufficient. Becomes When two or more binders are used in combination, the total amount of the binders should satisfy the above range.

  Examples of the thickener used for the negative electrode include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch and casein. These may be used alone or in any combination of two or more at any ratio. The thickener may be used as necessary, but when used, the content of the thickener in the negative electrode active material layer is usually 0.5% by mass or more and 5% by mass or less. Is preferred.

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

  The obtained negative electrode current collector is coated with the obtained slurry, dried, and then pressed to form a negative electrode active material layer. The coating method is not particularly limited, and a method known per se can be used. The drying method is not particularly limited, and known methods such as natural drying, heat drying, and vacuum drying can be used.

<Structure of negative electrode and manufacturing method>
For manufacturing the electrode, any known method can be used as long as the effect of the present invention is not significantly impaired. For example, it is formed by adding a binder, a solvent, and, if necessary, a thickener, a conductive material, a filler, etc. to the negative electrode active material to form a slurry, which is applied to a current collector, dried, and then pressed. You can
When an alloy material is used, a method of forming a thin film layer (negative electrode active material layer) containing the above negative electrode active material by a method such as a vapor deposition method, a sputtering method, or a plating method is also used.

(Electrode density)
The electrode structure when the negative electrode active material is formed into an electrode is not particularly limited, but the density of the negative electrode active material existing on the current collector is preferably 1 g · cm −3 or more, and 1.2 g · cm −3 or more. Is more preferable, 1.3 g · cm −3 or more is particularly preferable, 2.2 g · cm −3 or less is preferable, 2.1 g · cm −3 or less is more preferable, and 2.0 g · cm −3 or less is preferable. More preferably, 1.9 g · cm −3 or less is particularly preferable. If the density of the negative electrode active material present on the current collector exceeds the above range, the negative electrode active material particles are destroyed, the initial irreversible capacity increases, and the non-aqueous system near the current collector / negative electrode active material interface. High current density charge / discharge characteristics may be deteriorated due to a decrease in electrolyte permeability. On the other hand, if it is less than the above range, the conductivity between the negative electrode active materials may be lowered, the battery resistance may be increased, and the capacity per unit volume may be lowered.

2-2. Positive electrode <positive electrode active material>
The positive electrode active material (lithium transition metal compound) used for the positive electrode will be described below.
<Lithium transition metal compound>
The lithium transition metal-based compound is a compound having a structure capable of desorbing and inserting Li ions, and examples thereof include sulfides, phosphate compounds, and lithium transition metal composite oxides. The sulfide has a compound having a two-dimensional layered structure such as TiS2 or MoS2, and a strong three-dimensional skeleton structure represented by the general formula MexMo6S8 (Me is various transition metals such as Pb, Ag, and Cu). Examples include a suvrel compound. Examples of the phosphate compound include those belonging to the olivine structure, and are generally represented by LiMePO4 (Me is at least one kind of transition metal), and specific examples thereof include LiFePO4, LiCoPO4, LiNiPO4, LiMnPO4 and the like. Be done. Examples of the lithium-transition metal composite oxide include those belonging to a spinel structure capable of three-dimensional diffusion and a layered structure capable of two-dimensional diffusion of lithium ions. Those having a spinel structure are generally represented as LiMe2O4 (Me is at least one kind of transition metal), and specific examples thereof include LiMn2O4, LiCoMnO4, LiNi0.5Mn1.5O4, and LiCoVO4. Those having a layered structure are generally represented as LiMeO2 (Me is at least one or more transition metals). Specific examples thereof include LiCoO2, LiNiO2, LiNi1-xCoxO2, LiNi1-x-yCoxMnyO2, LiNi0.5Mn0.5O2, Li1.2Cr0.4Mn0.4O2, Li1.2Cr0.4Ti0.4O2, and LiMnO2.

<composition>
Further, the lithium-containing transition metal compound is, for example, a lithium transition metal-based compound represented by the following composition formula (F) or (G).

1) In the case of a lithium transition metal compound represented by the following composition formula (F)
Li1 + xMO2 (F)
However, x is usually 0 or more and 0.5 or less. M is an element composed of Ni and Mn or Ni, Mn and Co, and the Mn / Ni molar ratio is usually 0.1 or more and 5 or less. The Ni / M molar ratio is usually 0 or more and 0.5 or less. The Co / M molar ratio is usually 0 or more and 0.5 or less. In addition, the rich portion of Li represented by x may be replaced with the transition metal site M.

  In the composition formula (F), the atomic ratio of oxygen content is described as 2 for convenience, but it may have some non-stoichiometry. Further, x in the above composition formula is a composition charged at the stage of manufacturing the lithium transition metal-based compound. Batteries on the market are typically aged after the batteries are assembled. Therefore, the Li amount of the positive electrode may be lost due to charge / discharge. In that case, x may be measured to be −0.65 or more and 1 or less when discharged to 3 V in composition analysis.

Further, the lithium-transition metal compound is excellent in battery characteristics when it is fired at a high temperature in an oxygen-containing gas atmosphere in order to enhance the crystallinity of the positive electrode active material.
Further, the lithium transition metal-based compound represented by the composition formula (F) may be a solid solution with Li2MO3, which is called a 213 layer, as in the following general formula (F ′).
αLi2MO3 ・ (1-α) LiM'O2 ... (F ')
In the general formula, α is a number satisfying 0 <α <1.

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

2) In the case of a lithium transition metal compound represented by the following general formula (B).
Li [LiaMbMn2-ba] O4 + δ ... (G)
However, M is an element composed of at least one kind of transition metal selected from Ni, Cr, Fe, Co, Cu, Zr, Al and Mg.
The value of b is usually 0.4 or more and 0.6 or less.

When the value of b is in this range, the energy density per unit weight of the lithium transition metal compound is high.
The value of a is usually 0 or more and 0.3 or less. Further, a in the above composition formula is a composition charged at the stage of manufacturing the lithium transition metal compound. Batteries on the market are typically aged after the batteries are assembled. Therefore, the Li amount of the positive electrode may be lost due to charge / discharge. In that case, a may be measured to be −0.65 or more and 1 or less when discharged to 3 V in composition analysis.

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

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

From a structural point of view, it is considered that the lithium according to a is substituted and entered in the same transition metal site. Here, due to the lithium relating to a, the average valence of M and manganese becomes higher than 3.5 due to the principle of charge neutrality.
Further, the lithium transition metal-based compound may be fluorine-substituted and is represented by LiMn2O4-xF2x.

<blend>
Specific examples of the lithium transition metal compound having the above composition include, for example, Li1 + xNi0.5Mn0.5O2, Li1 + xNi0.85Co0.10Al0.05O2, Li1 + xNi0.33Mn0.33Co0.33O2, Li1 + xNi0.45Mn0.45Co0.1O2, Li1 + xMn1.8Al0. .2O4, Li1 + xMn1.5Ni0.5O4 and the like. These lithium transition metal compounds may be used alone or in a blend of two or more.

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

[Cathode for lithium secondary battery]
The positive electrode for a lithium secondary battery is formed by forming a positive electrode active material layer containing the above-mentioned lithium transition metal compound powder for a lithium secondary battery positive electrode material and a binder on a current collector.
The positive electrode active material layer is usually formed by dry-mixing a positive electrode material, a binder, and a conductive material and a thickener, which are optionally used, in the form of a sheet and press-bonding them to the positive electrode current collector. Alternatively, these materials are dissolved or dispersed in a liquid medium to form a slurry, which is applied to a positive electrode current collector and dried.

  As the material of the positive electrode current collector, a metal material such as aluminum, stainless steel, nickel plating, titanium, tantalum or the like, or a carbon material such as carbon cloth or carbon paper is usually used. As for the shape, in the case of a metal material, a metal foil, a metal cylinder, a metal coil, a metal plate, a metal thin film, an expanded metal, a punch metal, a foam metal, etc., and in the case of a carbon material, a carbon plate, a carbon thin film, a carbon cylinder. Etc. The thin film may be appropriately formed in a mesh shape.

When a thin film is used as the positive electrode current collector, its thickness is arbitrary, but a range of 1 μm or more and 100 mm or less is usually preferable. If the thickness is less than the above range, the strength required for the current collector may be insufficient, while if it is more than the above range, the handleability may be impaired.
The binder used in the production of the positive electrode active material layer is not particularly limited, and in the case of the coating method, any material that is stable with respect to the liquid medium used in the production of the electrode may be used. Resin polymers such as polypropylene, polyethylene terephthalate, polymethylmethacrylate, aromatic polyamide, cellulose and nitrocellulose, SBR (styrene / butadiene rubber), NBR (acrylonitrile / butadiene rubber), fluororubber, isoprene rubber, butadiene rubber, ethylene・ Rubber-like polymer such as propylene rubber, styrene / butadiene / styrene block copolymer and hydrogenated product thereof, EPDM (ethylene / propylene / diene terpolymer), styrene / ethylene / butadiene / ethylene copolymer, Styrene / isoprene styrene bro Thermoplastic elastomeric polymers such as copolymers and hydrogenated products thereof, syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene / vinyl acetate copolymers, propylene / α-olefin copolymers, etc. Fluorine-based polymers such as soft resinous polymers, polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene fluoride, polytetrafluoroethylene / ethylene copolymers, and ion conductivity of alkali metal ions (particularly lithium ions) Examples thereof include a polymer composition and the like. These substances may be used alone or in any combination of two or more at any ratio.

The proportion of the binder in the positive electrode active material layer is usually 0.1% by mass or more and 80% by mass or less. If the proportion of the binder is too low, the positive electrode active material cannot be sufficiently retained and the mechanical strength of the positive electrode is insufficient, which may deteriorate the battery performance such as cycle characteristics, while it is too high. It may lead to a decrease in battery capacity and conductivity.
The positive electrode active material layer usually contains a conductive material in order to enhance conductivity. The type is not particularly limited, but specific examples include metallic materials such as copper and nickel, graphite (graphite) such as natural graphite and artificial graphite, carbon black such as acetylene black, and amorphous carbon such as needle coke. Examples of the carbon material include These substances may be used alone or in any combination of two or more at any ratio. The proportion of the conductive material in the positive electrode active material layer is usually 0.01% by mass or more and 50% by mass or less. If the proportion of the conductive material is too low, the conductivity may be insufficient, and if it is too high, the battery capacity may decrease.

As the liquid medium for forming the slurry, it is possible to dissolve or disperse the lithium transition metal compound powder that is the positive electrode material, the binder, and the conductive material and the thickener that are used as necessary. There is no particular limitation on the type of solvent as long as it is a solvent, and 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, diethyltriamine, N. , N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran (THF), toluene, acetone, dimethyl ether, dimethylacetamide, hexamethylphosphamide, dimethylsulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, hexane and the like. be able to. Particularly when an aqueous solvent is used, a dispersant is added together with the thickener, and a latex such as SBR is used to form a slurry. These solvents may be used alone or in any combination of two or more at any ratio.

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

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

2-3. Separator 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.
The material and shape of the separator are not particularly limited, and any known material can be adopted 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 material or the like is used, and a porous sheet or a non-woven fabric-like material having excellent 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, aromatic polyamide, polytetrafluoroethylene, polyether sulfone, and glass filter 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 usually 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and usually 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less. If the separator is too thin than the above range, the insulating property and mechanical strength may decrease. On the other hand, if the thickness is more than the above range, not only the battery performance such as rate characteristics may deteriorate, but also the energy density of the entire non-aqueous electrolyte secondary battery may decrease.

Furthermore, when using a porous material such as a porous sheet or a nonwoven fabric as the separator, the porosity of the separator is arbitrary, but is usually 20% or more, preferably 35% or more, more preferably 45% or more, It is usually 90% or less, preferably 85% or less, more preferably 75% or less. If the porosity is smaller than the above range, the film resistance tends to increase and the rate characteristics tend to deteriorate. On the other hand, if it is larger than the above range, the mechanical strength of the separator tends to decrease, and the insulating property tends to decrease.

The average pore size of the separator is also arbitrary, but is usually 0.5 μm or less, preferably 0.2 μm or less, and usually 0.05 μm or more. When the average pore diameter exceeds the above range, short circuit is likely to occur. On the other hand, if it is less than the above range, the film resistance may increase and the rate characteristics may deteriorate.
On the other hand, examples of the inorganic material include oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate. Used.

  As the form, a non-woven fabric, a woven fabric, or a thin film-shaped one such as a microporous film is used. In the form of a thin film, one 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, the porous layer may be formed by using alumina particles having a 90% particle size of less than 1 μm on both surfaces of the positive electrode and using a fluororesin as a binder.

  The characteristics of the separator in the non-electrolyte secondary battery can be grasped by the Gurley value. The Gurley value indicates the difficulty of passing through air in the film thickness direction and is represented by the number of seconds required for 100 ml of air to pass through the film. Therefore, the smaller the value, the easier it is to pass through, and the larger the value. It means that it is harder to pass through. That is, the smaller the value, the better the communication in the thickness direction of the film, and the larger the value, the poor the communication in the thickness direction of the film. The connectivity is the degree of connection of holes in the film thickness direction. If the Gurley value of the separator of the present invention is low, it can be used for various purposes. For example, when used as a separator for a non-aqueous lithium secondary battery, a low Gurley value means that lithium ions can move easily, and is preferable because of excellent battery performance. The Gurley value of the separator is arbitrary, but is preferably 10 to 1000 seconds / 100 ml, more preferably 15 to 800 seconds / 100 ml, and further preferably 20 to 500 seconds / 100 ml. When the Gurley value is 1000 seconds / 100 ml or less, the electric resistance is substantially low and it is preferable as a separator.

2-4. 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, and a structure having a structure in which the positive electrode plate and the negative electrode plate are spirally wound with the separator interposed therebetween. Either is fine. The ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as the electrode group occupancy rate) is usually 40% or more, preferably 50% or more, and usually 90% or less, preferably 80% or less. ..

  When the electrode group occupancy rate is below the above range, the battery capacity becomes small. In addition, if it exceeds the above range, the void space is small, the internal pressure rises because the member expands or the vapor pressure of the liquid component of the electrolyte increases due to the high temperature of the battery, and the repeated charge and discharge performance as a battery In some cases, various characteristics such as high temperature storage may be deteriorated, and further, a gas release valve that releases the internal pressure to the outside may operate.

<Exterior case>
The material of the outer case is not particularly limited as long as it is a stable substance with respect to the non-aqueous electrolyte solution used. Specifically, a nickel-plated steel sheet, metals such as stainless steel, aluminum or aluminum alloy, and magnesium alloy, 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 an outer case using metals, laser welding, resistance welding, ultrasonic welding is used to weld metals to each other to form a hermetically sealed structure, or a caulking structure using the above metals via a resin gasket. There are things. 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.

<Protective element>
As a protection element, PTC (Positive Temperature Coefficient) whose resistance increases when abnormal heat generation or excessive current flows, thermal fuse, thermistor, cuts off the current flowing to the circuit due to a sudden rise in battery internal pressure or internal temperature during abnormal heat generation A valve (current cutoff valve) or the like can be used. The protective element is preferably selected under the condition that it does not operate under high current in normal use, and it is more preferable to design it so as not to cause abnormal heat generation or thermal runaway without the protective 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, a 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 above 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 above metals through 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, any of a cylindrical shape, a rectangular shape, a laminated type, a coin type, a large size, and the like.

3. Examples The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.
The compounds used in this example and comparative examples are shown below.

<Examples 1-1 to 1-3, Comparative examples 1-1 to 1-6>
[Preparation of non-aqueous electrolyte]
Under a dry argon atmosphere, 1.2 mol / mol of sufficiently dried LiPF6 was added to a mixture (volume / volume ratio 3: 4: 3) of ethylene carbonate (EC), ethylmethyl carbonate (EMC), and diethyl carbonate (DEC). L (as the concentration in the non-aqueous electrolytic solution) was dissolved, and further 2.0 mass% each of vinylene carbonate (VC) and monofluoroethylene carbonate (MFEC) were added (this is referred to as reference electrolytic solution 1). .. Compounds were added to the entire standard electrolytic solution 1 at the ratios shown in Table 1 below to prepare an electrolytic solution. However, Comparative Example 1-1 is the reference electrolyte solution 1 itself.

[Production of positive electrode]
97 mass% of lithium cobalt oxide (LiCoO2) as a positive electrode active material, 1.5 mass% of acetylene black as a conductive material, and 1.5 mass% of polyvinylidene fluoride (PVdF) as a binder, an N-methylpyrrolidone solvent. The mixture was mixed with a disperser into a slurry. This was uniformly applied to both sides of an aluminum foil having a thickness of 21 μm, dried, and then pressed to obtain a positive electrode.

[Fabrication of negative electrode]
Natural graphite powder as a negative electrode active material, a thickener, and a binder as 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). (Concentration: 50% by mass) and mixed with a disperser to form a slurry. This slurry was uniformly applied to one surface of a copper foil having a thickness of 12 μm, dried, and then pressed to obtain a negative electrode. The dried negative electrode was prepared so that the mass ratio of natural graphite: sodium carboxymethyl cellulose: styrene butadiene rubber = 98: 1: 1.

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

<Evaluation of non-aqueous electrolyte secondary battery>
[Initial conditioning]
A non-aqueous electrolyte secondary battery of a laminate type cell was charged with a current corresponding to 0.05 C for 6 hours in a constant temperature bath at 25 ° C., and then discharged to 3.0 V at 0.2 C. CC-CV charging was performed up to 4.1V at 0.2C. Then, aging was performed under the conditions of 45 ° C. and 72 hours. After that, the battery was discharged at 0.2 C to 3.0 V to stabilize the non-aqueous electrolyte secondary battery. Further, CC-CV charging was performed at 0.2 C to 4.4 V, and then discharge was performed at 0.2 C to 3.0 V to perform initial conditioning.

<Evaluation of non-aqueous electrolyte secondary battery>
[Charge preservation test]
The cell after the initial capacity evaluation was again CC-CV charged at 0.2 C to 4.4 V, and then stored at high temperature at 85 ° C. for 24 hours. After the battery was sufficiently cooled, it was immersed in an ethanol bath to measure the volume, and the amount of generated gas was determined from the volume change before and after the storage test, and this was defined as the "charged storage gas amount".
Table 1 below shows the charge storage gas amount standardized by the value of Comparative Example 1-1.

As is clear from Table 1, when a non-aqueous electrolyte containing Compound 1, which is a compound represented by General Formula (1) of the present invention, was used, it was compared with Comparative Example 1-1 containing no Compound 1. , Has been shown to suppress charge storage gas. In addition, as in Comparative Examples 1-2 to 1-6, it is shown that the charged storage gas increases when the compound 2 which is a compound other than the compound represented by the general formula (1) is contained. From these, it is understood that the use of the non-aqueous electrolyte containing the compound represented by the general formula (1) as the non-aqueous electrolyte improves the battery swelling during charge storage.

<Examples 2-1 to 2-3, Comparative examples 2-1 to 2-2>
The same non-aqueous electrolyte battery as in Example 1 was prepared and tested.
<Evaluation of non-aqueous electrolyte secondary battery>
[Initial conditioning]
A non-aqueous electrolyte secondary battery of a laminate type cell was charged with a current corresponding to 0.05 C for 6 hours in a constant temperature bath at 25 ° C., and then discharged to 3.0 V at 0.2 C. CC-CV charging was performed up to 4.1V at 0.2C. Then, aging was performed under the conditions of 45 ° C. and 72 hours. After that, the battery was discharged at 0.2 C to 3.0 V to stabilize the non-aqueous electrolyte secondary battery. Further, CC-CV charging was performed at 0.2 C to 4.4 V, and then discharge was performed at 0.2 C to 3.0 V to perform initial conditioning.

<Evaluation of non-aqueous electrolyte secondary battery>
[Continuous charge test]
The non-aqueous electrolyte battery after the initial capacity evaluation was subjected to CCCV charging (168 hours cut) at 0.2 ° C. to 4.4 V at 60 ° C. to perform a continuous charging test.
Table 2 below shows the charge capacities in the continuous charge test, which are standardized with the values of Comparative Example 2-1.

  As is clear from Table 2, when a non-aqueous electrolyte containing Compound 1 which is a compound represented by the general formula (1) of the present invention was used, it was compared with Comparative Example 2-1 containing no Compound 1. It has been shown that the charging capacity in the continuous charging test is suppressed. Further, as in Comparative Example 2-2, it is shown that the effect of suppressing the charge capacity cannot be obtained when the compound 2 which is a compound other than the specific compound represented by the general formula (1) is contained. From these, it is understood that the side reaction in the continuous charge test is suppressed by using the non-aqueous electrolyte solution containing the compound represented by the general formula (1) as the non-aqueous electrolyte solution.

According to the non-aqueous electrolyte solution of the present invention, the discharge storage characteristics and the high temperature storage characteristics are improved in a well-balanced manner, so that the non-aqueous electrolyte solution can be suitably used in all fields such as electronic devices in which the non-aqueous electrolyte secondary battery is used. Further, it can be suitably used in an electrolytic capacitor such as a lithium ion capacitor using a non-aqueous electrolytic solution.
The application of the non-aqueous electrolyte solution and the non-aqueous electrolyte secondary battery of the present invention is not particularly limited, and it can be used for various known applications. Specific examples of its applications include laptop computers, e-book players, mobile phones, mobile faxes, mobile copiers, mobile printers, mobile audio players, small video cameras, LCD TVs, handy cleaners, transceivers, electronic organizers, calculators, and memories. Examples include cards, portable tape recorders, radios, backup power supplies, automobiles, motorcycles, motorbikes, bicycles, lighting equipment, toys, game machines, watches, electric tools, strobes, cameras, and the like.

Claims (9)

A non-aqueous electrolyte solution for a secondary battery, comprising a positive electrode and a negative electrode capable of occluding and releasing metal ions, the non-aqueous electrolyte solution together with an alkali metal salt and a non-aqueous solvent, represented by the following general formula (1): A compound represented by 0.001% by mass or more with respect to the total amount of the non-aqueous electrolyte solution
A non-aqueous electrolyte solution characterized by being contained in an amount of not more than% .

(In the formula (1), R ¹ , R ² and Y each represent a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent. R ¹ , R ² and Y are the same. Or R ¹ , R ² and Y do not bond to each other to form a ring.) In the said General formula (1), Y is a C1-C12 alkyl group, The non-aqueous electrolyte solution of Claim 1 characterized by the above-mentioned. In the general formula (1), R ¹ and R ^2, nonaqueous electrolyte according to claim 1 or 2, characterized in that an alkyl group having 1 to 12 carbon atoms. The non-aqueous electrolyte, further carbon-cyclic carbonate having a carbon unsaturated bond, a cyclic carbonate having a fluorine atom, a nitrile compound, an isocyanate compound, a compound having an isocyanuric acid skeleton, a fluorophosphate, a fluorosulfonate, and nonaqueous electrolyte solution according to any one of claims 1 to 3, characterized in that it contains at least one compound selected from the group consisting of cyclic sulfonic acid ester. A cyclic carbonate having a carbon-carbon unsaturated bond, a cyclic carbonate having a fluorine atom, a nitrile compound, an isocyanate compound, a compound having an isocyanuric acid skeleton, a fluorophosphate salt, a fluorosulfonate salt, and a cyclic sulfonate ester. The content of at least one compound selected from the group is 0.001% by mass or more and 10% by mass or less with respect to the total amount of the nonaqueous electrolytic solution, and the nonaqueous electrolytic solution according to claim 4. .. And capable of absorbing and desorbing lithium ions cathode, a lithium ion and capable of absorbing and desorbing negative electrode, the nonaqueous electrolyte secondary battery comprising a nonaqueous electrolyte solution, nonaqueous electrolyte solution, according to claim 1 to 5 9. A non-aqueous electrolyte secondary battery, which is the non-aqueous electrolyte solution according to any one of 1. The non-aqueous electrolyte secondary battery according to claim 6 , wherein the negative electrode active material of the negative electrode capable of inserting and extracting lithium ions contains carbon as a constituent element. 7. The non-aqueous electrolyte solution according to claim 6 , wherein the negative electrode active material of the negative electrode capable of inserting and extracting lithium ions has at least one of silicon (Si) and tin (Sn) as a constituent element. Next battery. 6. a negative electrode active material of the lithium ion occluding and releasable negative electrode, characterized in that it is a mixture or complex of particles and graphite particles as constituent elements, silicon (Si) or tin (Sn) The non-aqueous electrolyte solution described in.