JP2000348761A - Nonaqueous electrolytic solution and secondary battery using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolytic solution capable of furthering rapid operation of a pressure release device at an overcharge time to restrain the rise of a battery voltage and capable of preventing rapid rise of battery temperature and battery internal pressure by forming the electrolytic solution with a nonaqueous solvent containing a specific carbamate compound and an electrolyte. SOLUTION: A carbamate compound is expressed by the formula I. In the formula, R1 is a 3-12C cycloalkyl group, R2 and R3 may be the same or different from each other and is 1-12C hydrocarbon group that may contain at least one kind of atom selected from an oxygen, nitrogen and sulfur atoms. Preferably, in this nonaqueous electrolytic solution, the compound expressed by the formula I is any of compounds expressed by the formula II; and a nonaqueous solvent contains the carbamate compound expressed by the formula I and cyclic carbonic ester and/or chain carbonic ester expressed by the formula III or formula IV (in the formula III or formula IV, R4 and R5 each are a hydrogen atom or 1-6C alkyl group, and R4 and R5 may be the same or different).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous electrolyte having excellent overcharge prevention properties and a secondary battery using the same. More specifically, the present invention provides a non-aqueous electrolyte which uses a specific non-aqueous solvent to prevent rapid heat generation of a battery due to overcharge, and a non-aqueous electrolyte secondary using the same. Battery.

[0002]

BACKGROUND OF THE INVENTION A battery using a non-aqueous electrolyte has a high voltage, a high energy density, and a high reliability such as storability, so that it is widely used as a power source for consumer electronic devices. Have been.

As such a battery, there is a non-aqueous electrolyte secondary battery, a typical example of which is a lithium ion secondary battery. Carbonate compounds having a high dielectric constant are known as non-aqueous solvents used for such a purpose, and the use of various carbonate compounds has been proposed. As an electrolytic solution, LiBF ₄ , LiPF ₆ , LiPF ₆ , a mixed solvent of the high dielectric constant carbonate compound solvent such as propylene carbonate and ethylene carbonate, and a low viscosity solvent such as diethyl carbonate.
A solution in which an electrolyte such as LiClO ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , or Li ₂ SiF ₆ is mixed is used.

[0004] On the other hand, research on electrodes has been promoted with the aim of increasing the capacity of batteries, and carbon materials capable of occluding and releasing lithium are used as negative electrodes of lithium ion secondary batteries.

[0005] However, in the conventional explosion-proof sealed batteries, if the overcharge state continues for a long time, an abnormal exothermic reaction continues even after the current interrupting device or the pressure release device is operated, and the battery temperature becomes 50 ° C. In some cases, the temperature rapidly increased from ６０60 ° C. to 300 to 400 ° C., and the internal pressure increased rapidly.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and promptly operates a pressure relief device when a battery is overcharged, and suppresses a rise in battery voltage. It is another object of the present invention to provide a non-aqueous electrolyte which has characteristics of preventing a rapid rise in battery temperature and battery internal pressure. Another object is to provide a secondary battery including the non-aqueous electrolyte.

[0007]

Means for Solving the Problems The non-aqueous electrolyte according to the present invention relates to a non-aqueous electrolyte comprising a non-aqueous solvent containing a carbamate compound represented by the following general formula [1] and an electrolyte.

Embedded image ... [1]

(In the formula [1], R ¹ is a cycloalkyl group having 3 to 12 carbon atoms, R ² and R ³ may be the same or different from each other, and include an oxygen atom, a nitrogen atom, a sulfur atom, It is a C1-C12 hydrocarbon group which may contain at least one atom selected from atoms.)

Further, the non-aqueous solvent comprises a carbamate compound represented by the above general formula [1] and a cyclic carbonate and / or a chain carbonate represented by the following general formula [3a] or [3b]: With this configuration, rapid heat generation of the battery due to overcharging can be prevented, and a non-aqueous electrolyte having excellent battery characteristics, particularly excellent low-temperature characteristics and cycle characteristics, can be provided.

Embedded image [3a] [3b] (In the formula [3a] or [3b], R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ⁴ and R ⁵ are different even if they are the same. May be.)

Further, these non-aqueous electrolytes preferably use a lithium salt as an electrolyte, and such a non-aqueous electrolyte can be effectively used as an electrolyte for a primary battery or a secondary battery.

[0011] The present invention also provides a method for doping lithium metal, a lithium-containing alloy, and lithium ion as a negative electrode active material.
A negative electrode including any of the undoped carbon materials, a positive electrode including any of a composite oxide of lithium and a transition metal as the positive electrode active material, a carbon material or a mixture thereof, and the nonaqueous electrolyte Related to secondary batteries.

[0012]

Next, the non-aqueous electrolyte according to the present invention and a non-aqueous electrolyte secondary battery using this non-aqueous electrolyte will be described in detail. The non-aqueous electrolyte according to the present invention comprises a non-aqueous solvent containing a carbamate compound and an electrolyte, and each will be described in detail.

Carbamate Compound As the carbamate compound contained in the non-aqueous solvent in the present invention, a compound represented by the following general formula [1] is used.

Embedded image ... [1] (In formula [1], R ¹ is a cycloalkyl group having 3 to 12 carbon atoms, and R ² and R ³ may be the same or different from each other, and include an oxygen atom, a nitrogen atom And at least one atom selected from the group consisting of a carbon atom and a sulfur atom (i.e., containing or not containing at least one atom selected from an oxygen atom, a nitrogen atom and a sulfur atom).
2 hydrocarbon groups. )

As R ¹ , specifically, cyclopropyl, methylcyclopropyl, ethylcyclopropyl, cyclobutyl, methylcyclobutyl, ethylcyclobutyl, cyclopentyl, methylcyclopentyl, ethylcyclopentyl, Examples thereof include a cyclohexyl group, a methylcyclohexyl group, an ethylcyclohexyl group, a cycloheptyl group, a methylcycloheptyl group, an ethylcycloheptyl group, a cyclooctyl group, a methylcyclooctyl group, and an ethylcyclooctyl group. Among these, a cyclopentyl group and a cyclohexyl group are particularly preferred. As R ² and R ³ , specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-
Butyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 2-methyl-2-propenyl group, 1-methylenepropyl group, 1-methyl-2-propenyl group, 1,2-dimethylvinyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-methyl-2-methylpropyl group, 2,2-dimethylpropyl group And other linear or branched alkyl groups having 1 to 12 carbon atoms such as hexyl, octyl, nonyl and decyl, phenyl, toluyl, methoxyphenyl, naphthyl, pyridyl, R ² and R ³ , Piperidine, piperazine, pyrrolidine, morpholine, etc. directly or via one or more nitrogen, sulfur and / or oxygen atoms. Among these, an alkyl group having 1 to 12 carbon atoms is preferable, and an ethyl group, an n-propyl group and an isopropyl group are particularly preferable.

Specific examples of preferred compounds among the compounds represented by the general formula [1] include compounds represented by the following formula.

Embedded image ... [2]

These carbamate compounds represented by the above general formula [1] can be used alone or in combination of two or more. In the present invention, these carbamates are contained in a non-aqueous solvent. This facilitates the quick operation of the pressure relief device when the battery is overcharged,
A rise in battery voltage can be suppressed, and a rapid rise in battery temperature and battery internal pressure can be prevented.

Nonaqueous Solvent In the nonaqueous electrolyte according to the present invention, a nonaqueous solvent containing a compound containing a carbamate represented by the above general formula [1] is used. This compound can be used as an additive to a commonly used non-aqueous solvent or as a solvent constituting a non-aqueous solvent. Carbamate compounds are all non-aqueous solvents (total amount of carbamate compounds and other non-aqueous solvents)
0.001% by weight or more, preferably 0.01 to
It is desirable that it be contained in an amount of 99.5% by weight, more preferably 0.01 to 70% by weight, particularly preferably 0.05 to 30% by weight. When the carbamate compound represented by the general formula [1] is contained in the total non-aqueous solvent at such a mixing ratio, when the battery is overcharged, prompt operation of the pressure relief device is promoted, and the battery voltage is reduced. , And a rapid increase in battery temperature and battery internal pressure can be prevented. In particular, in the present invention, when a non-aqueous solvent containing the above carbamates and a cyclic carbonate and / or a chain carbonate represented by the following general formula [3a] or [3b] is used, the rapid charging of the battery due to overcharging occurs. Preferably, it is possible to prevent heat generation and increase in battery internal pressure, and to obtain a non-aqueous electrolyte having excellent battery characteristics, especially low-temperature characteristics and cycle characteristics.

Examples of the cyclic carbonate include a cyclic carbonate and / or a chain carbonate represented by the following general formula [3a] or [3b].

Embedded image [3a] [3b] In the formula [3a] or [3b], R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ⁴ and R ⁵
May be the same or different. Among them, the alkyl group is preferably an alkyl group having 1 to 3 carbon atoms,
Specific examples include a methyl group, an ethyl group, and an n-propyl group.

Specific examples of the cyclic carbonate represented by the general formula [3a] or [3b] include ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 2-pentylene carbonate, 2,3-pentylene carbonate, vinylene carbonate and the like. Among these, particularly preferred cyclic carbonates are ethylene carbonate, propylene carbonate and vinylene carbonate. These cyclic carbonates may be used as a mixture of two or more kinds.

Specific examples of the chain carbonate include dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, and ethyl propyl carbonate. These chain carbonates are 2
You may mix and use more than one kind.

When such a chain carbonate is contained in a non-aqueous solvent, the viscosity of the non-aqueous electrolyte can be reduced, the solubility of the electrolyte can be further increased, and the electric conductivity at normal temperature or low temperature can be improved. It is possible to obtain an electrolytic solution having excellent properties.
Therefore, it is possible to improve the charge / discharge efficiency of the battery and low-temperature characteristics such as, for example, the charge / discharge efficiency at low temperatures and the load characteristics at low temperatures.

When the cyclic carbonate and / or chain carbonate represented by the general formula [3a] or [3b] is used as the nonaqueous solvent, the carbamates represented by the general formula [1] All nonaqueous solvents containing the same (the total amount of the carbamate compound represented by the general formula [1] and the cyclic carbonate and / or chain carbonate represented by the general formula [3a] or [3b]) ) To 0.001% by weight or more, preferably 0.01 to 99.%.
It is desirable that it be contained in an amount of 5% by weight, more preferably 0.01 to 70% by weight, particularly preferably 0.05 to 30% by weight.

Further, the above-mentioned general formula [3a] in a non-aqueous solvent
Alternatively, the mixing ratio of the cyclic carbonate and the chain carbonate represented by [3b] is represented by a weight ratio, and the ratio of the cyclic carbonate: chain carbonate is 0: 100 to 100:
0, preferably 5:95 to 95: 5, particularly preferably 2
0:80 to 85:15.

Therefore, a preferred non-aqueous solvent according to the present invention is a carbamate compound represented by the general formula [1] and a cyclic carbonate represented by the general formula [3a] or [3b] and / or It contains a chain carbonate. In addition, it is also possible to further mix and use a solvent widely used as a non-aqueous solvent for batteries. Specific examples of the solvent that can be used include methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate,
Chain esters such as ethyl propionate; phosphate esters such as trimethyl phosphate; chain ethers such as dimethoxyethane; cyclic ethers such as tetrahydrofuran;
Amide such as dimethylformamide; Cyclic ester such as γ-butyrolactone; Cyclic sulfone such as sulfolane; Cyclic carbamate such as N-methyloxazolidinone; Cyclic amide such as N-methylpyrrolidone; Cyclic urea such as N, N-dimethylimidazolidinone And the like.

Nonaqueous Electrolyte The nonaqueous electrolyte of the present invention comprises a nonaqueous solvent containing the above-mentioned specific carbamate compound and an electrolyte. For example, the nonaqueous solvent containing the above specific carbamate compound contains It is obtained by dissolving an electrolyte. As the electrolyte to be used, any electrolyte which is usually used as an electrolyte for a non-aqueous electrolyte can be used.

As a specific example of the electrolyte, LiPF₆, Li
BF_Four, LiClO_Four, LiAsF₆, Li _TwoSiF₆, LiC_FourF
₉SO_Three, LiC₈F₁₇SO_ThreeLithium salts such as
You. In addition, a lithium salt represented by the following general formula is also used.
be able to. LiOSO_TwoR⁶, LiN (SO_TwoR⁷) (SO_Two
R⁸), LiC (SO_TwoR⁹) (SO_TwoR^Ten) (SO_TwoR¹¹), LiN
(SO_TwoOR¹²) (SO_TwoOR¹³) (Where R⁶~ R¹³Is
They may be the same or different from each other and have 1 to 1 carbon atoms.
6 is a perfluoroalkyl group). These lithu
Salt may be used alone or as a mixture of two or more.
May be used.

Of these, LiPF ₆ , LiBF ₄ ,
LiOSO ₂ R ⁶ , LiN (SO ₂ R ⁷ ) (SO ₂ R ⁸ ), LiC (S
O ₂ R ⁹ ) (SO ₂ R ¹⁰ ) (SO ₂ R ¹¹ ), LiN (SO ₂ OR ¹² )
(SO ₂ OR ¹³ ) is preferred.

It is desirable that such an electrolyte is usually contained in the non-aqueous electrolyte at a concentration of 0.1 to 3 mol / l, preferably 0.5 to 2 mol / l.

The non-aqueous electrolyte in the present invention contains a non-aqueous solvent containing the above-mentioned specific carbamate compound and an electrolyte as essential components, but other additives may be added as necessary.

The non-aqueous electrolyte according to the present invention as described above comprises:
Not only is it suitable as a non-aqueous electrolyte for lithium ion secondary batteries, but it can also be used as a non-aqueous electrolyte for primary batteries.

The non-aqueous electrolyte secondary battery according to the present invention comprises a negative electrode, a positive electrode,
The non-aqueous electrolyte is basically configured to include,
Usually, a separator is provided between the negative electrode and the positive electrode.

As the negative electrode active material constituting the negative electrode, any of lithium metal, a lithium alloy, and a carbon material capable of doping / de-doping lithium ions can be used. Among these, a carbon material capable of doving / de-doping lithium ions is preferable. Such a carbon material may be graphite or amorphous carbon, and activated carbon, carbon fiber, carbon black, mesocarbon microbeads and the like are used.

As the positive electrode active material constituting the positive electrode, Mo is used.
Transition metal oxides or sulfides such as S ₂ , TiS ₂ , MnO ₂ , V ₂ O ₅ , LiCoO ₂ , LiMnO ₂ , LiMn ₂
A composite oxide composed of lithium and a transition metal such as O ₄ and LiNiO ₂ can be used. Among these, a composite oxide composed of lithium and a transition metal is particularly preferable. When the negative electrode is a lithium metal or lithium alloy, a carbon material can be used as the positive electrode. Also, as a positive electrode,
A mixture of a composite oxide of lithium and a transition metal and a carbon material can also be used.

The separator is a porous membrane, and usually a microporous polymer film is suitably used. In particular, a porous polyolefin film is preferable, and specific examples thereof include a porous polyethylene film, a porous polypropylene film, and a multilayer film of a porous polyethylene film and polypropylene.

Such a non-aqueous electrolyte secondary battery can be formed in a cylindrical shape, a coin shape, a square shape, or any other shape. However, the basic structure of the battery is the same regardless of the shape, and the design can be changed according to the purpose. Next, the structures of the cylindrical and coin type batteries will be described. The negative electrode active material, the positive electrode active material, and the separator constituting each battery are commonly used.

For example, in the case of a cylindrical non-aqueous electrolyte secondary battery, a negative electrode obtained by applying a negative electrode active material to a negative electrode current collector,
A positive electrode formed by applying a positive electrode active material to a positive electrode current collector is wound through a severator in which a non-aqueous electrolyte is injected, and is housed in a battery can with an insulating plate placed above and below the wound body. ing.

The non-aqueous electrolyte secondary battery according to the present invention can be applied to a coin-type non-aqueous electrolyte secondary battery. In a coin-type battery, a disk-shaped negative electrode, a separator, a disk-shaped positive electrode, and a stainless steel plate are housed in a coin-type battery can in a state of being stacked in this order.

[0038]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[0039]

Example 1 <Preparation of non-aqueous electrolyte> Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed with E
After mixing at a ratio of C: DEC = 58: 42 (weight ratio), cyclohexyl-N, N-diethylcarbamate (hereinafter sometimes abbreviated as CHyECA) represented by the following structural formula with respect to 95 parts by weight of the mixed solvent. Was added to prepare a non-aqueous solvent such that the amount of CHyECA was 5% by weight based on the total amount of the non-aqueous solvent (the total amount of EC, DEC, and CHyECA). Next, LiPF ₆ as an electrolyte was dissolved in a non-aqueous solvent, and a non-aqueous electrolyte was prepared so that the electrolyte concentration was 1.0 mol / L.

Embedded image .... [2]

<Preparation of Negative Electrode> Mesocarbon microbeads (trade name: MCMB6-28, d, manufactured by Osaka Gas Co., Ltd.)
002 = 0.337 nm, 90 parts by weight of carbon powder having a density of 2.17 g / cm ³ ) and 10 parts by weight of polyvinylidene fluoride (PVDF) as a binder were mixed, and N-
The paste was dispersed in methylpyrrolidone to prepare a paste-like negative electrode mixture slurry. Next, this negative electrode mixture slurry was applied to a negative electrode current collector made of a 20-μm-thick strip-shaped copper foil, and dried to obtain a strip-shaped carbon negative electrode. The thickness of the negative electrode mixture after drying is 2
It was 5 μm. Furthermore, this strip electrode is 15 mm in diameter.
, And compression molded to form a negative electrode.

<Preparation of Positive Electrode> L manufactured by Honjo Chemical Co., Ltd.
iCoO ₂ (product name: HLC-21, average particle size 8 μm)
91 parts by weight of fine particles, 6 parts by weight of graphite as a conductive material, and polyvinylidene fluoride (PVD) as a binder
F) was mixed with 3 parts by weight to prepare a positive electrode mixture, and dispersed in N-methylpyrrolidone to obtain a positive electrode mixture slurry. This slurry was applied to a 20-μm-thick aluminum foil positive electrode current collector, dried, and compression-molded to obtain a belt-shaped positive electrode. The thickness of the positive electrode mixture after drying was 40 μm.
Thereafter, the strip-shaped electrode was punched into a disk having a diameter of 15 mm to obtain a positive electrode.

<Preparation of Battery> A disk-shaped negative electrode and a disk-shaped positive electrode thus obtained, and a separator made of a microporous polypropylene film having a thickness of 25 μm and a diameter of 19 mm were prepared. After each of the negative electrode, the separator, and the positive electrode were laminated in the order of a 2032-sized stainless steel battery can, the nonaqueous electrolyte was injected into the separator.
Then, a stainless steel plate (2.4 m thick) was placed in the battery can.
m, diameter 15.4 mm), and the battery can (lid) was caulked via a gasket made of polypropylene.
As a result, the airtightness in the battery can be maintained, the diameter is 20 mm,
A button-type nonaqueous electrolyte secondary battery having a height of 3.2 mm was obtained.

<Measurement of Battery Expansion Rate and Battery Voltage> When the battery voltage rises during overcharge, a rapid rise in the battery temperature and battery internal pressure occurs. To prevent this, at the time of overcharge,
In order to suppress the rise in battery voltage (that is, the voltage at the time of overcharge (the end voltage) is small) and to promptly operate the pressure relief device, gas is generated (that is, the battery expansion rate is large).
Non-aqueous electrolytes are preferred. The battery voltage and gas generation during overcharging of the battery using these non-aqueous electrolytes were evaluated by the following methods. Using the produced button-type secondary battery, charging and discharging were performed at 2.8 V to 4.2 V and 1 mA at room temperature for only one cycle. Next, charge at a constant current of 1 mA for 12 minutes, and pause for 3 minutes for 3 minutes.
After repeating 0 times, the battery thickness (this was taken as the battery thickness after the test) and the battery voltage (this was taken as the termination voltage) were measured. The battery expansion coefficient was calculated from the measured battery thickness by the following equation. The results are shown in Table 1. The expansion of the battery is due to the generated gas, not to the expansion of other members.

Battery expansion coefficient (%) = [(battery thickness after test−battery thickness before test) / battery thickness after test] × 100

[0045]

Comparative Example 1 In Example 1, cyclohexyl-N,
Except that N-diethylcarbamate (CHyECA) was not added, a non-aqueous electrolyte solution was prepared and a battery was prepared in the same manner as in Example 1. The battery expansion coefficient and battery voltage were measured in the same manner as in Example 1. evaluated. The results are shown in Table 1.

[0046]

[Table 1]

[0047]

The non-aqueous electrolyte of the present invention promotes the rapid operation of the pressure relief device at the time of overcharging of the battery, suppresses the rise of the battery voltage, and prevents the rapid rise of the battery temperature and the internal pressure of the battery. can do. Therefore, this non-aqueous electrolyte is particularly suitable as a non-aqueous electrolyte for a lithium ion secondary battery, and in the present invention, by using this non-aqueous electrolyte,
A secondary battery capable of preventing a rapid increase in battery temperature and battery internal pressure was provided.

Continuing from the front page (72) Inventor Takehiko Omi 580-32, Takuji, Nagaura-shi, Sodegaura-shi, Chiba (72) Inventor Tatsuri Ishida 580-32-3, Takuji, Nagaura, Sodegaura-shi, Chiba (72) Inventor Hitoshi Onishi 580-32 Takuji, Nagaura-shi, Sodegaura-shi, Chiba F-term (reference) 5H029 AJ12 AK02 AK03 AK05 AK06 AK18 AL06 AL07 AL08 AL12 AM02 AM03 AM04 AM05 AM07 DJ08 EJ11 HJ02

Claims (9)

[Claims] 1. A non-aqueous electrolyte comprising a non-aqueous solvent containing a carbamate compound represented by the general formula [1] and an electrolyte. Embedded image ... [1] (In formula [1], R ¹ is a cycloalkyl group having 3 to 12 carbon atoms, and R ² and R ³ may be the same or different from each other, and include an oxygen atom, a nitrogen atom And 1 carbon atom which may contain at least one atom selected from sulfur atoms
To 12 hydrocarbon groups. ) 2. A compound represented by the general formula [1]:
The non-aqueous electrolyte according to claim 1, wherein the non-aqueous electrolyte is any compound represented by the following chemical formula. Embedded image ... [2] 3. The method according to claim 1, wherein the non-aqueous solvent comprises a carbamate compound represented by the general formula [1] and a carbamate compound represented by the general formula [3a] or [3]:
2. The non-aqueous electrolyte according to claim 1, comprising a cyclic carbonate and / or a chain carbonate represented by b). Embedded image [3a] [3b] (In the formula [3a] or [3b], R ⁴ and R ⁵ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ⁴ and R ⁵ are different even if they are the same. May be.) 4. The cyclic carbonate represented by the general formula [3a] or [3b] is a compound selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate and vinylene carbonate. The non-aqueous electrolyte according to claim 3. 5. The non-aqueous electrolyte according to claim 3, wherein said chain carbonate is a compound selected from the group consisting of dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate. 6. The carbamate compound represented by the general formula [1] is contained in an amount of 0.01 to 99.5% by weight based on the total amount of the nonaqueous solvent.
6. The non-aqueous electrolyte according to claim 1, wherein the non-aqueous electrolyte is contained. 7. The non-aqueous electrolyte according to claim 1, wherein the electrolyte is a lithium salt. 8. A secondary battery comprising the non-aqueous electrolyte according to claim 1. 9. A negative electrode containing any of lithium metal, a lithium-containing alloy and a carbon material capable of doping / dedoping lithium ions as a negative electrode active material, a composite oxide of lithium and a transition metal as a positive electrode active material, A lithium ion secondary battery comprising: a positive electrode containing any of the materials or a mixture thereof; and the nonaqueous electrolyte according to any one of claims 1 to 7.