JP2003123839A - Non-aqueous electrolyte for lithium secondary battery and lithium secondary battery using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high energy-density lithium secondary battery high in charging-discharging efficiency, excellent in capacity retaining property and also excellent in both cell characteristics and safety over a wide temperature range, and a non-aqueous electrolyte used therein. SOLUTION: The electrolyte is obtained by dissolving a lithium salt in a non-aqueous solvent. The non-aqueous solvent contains a compound having a 1,2,3-oxadiazolim-5-olate skeleton.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a non-aqueous electrolyte solution for a lithium secondary battery and a lithium secondary battery using the same. More specifically, the present invention relates to a lithium secondary battery having a high energy density, which has a function of stopping the progress of overcharge without deteriorating the battery characteristics and is excellent in safety, and a non-aqueous electrolyte solution that provides the same. .

[0002]

2. Description of the Related Art With the recent lightening and miniaturization of electric products, development of lithium secondary batteries having a high energy density has been desired more than ever, and the application fields of lithium secondary batteries are expanding. Accordingly, improvement of battery characteristics is also demanded. As the non-aqueous electrolyte solution for a lithium secondary battery, for example, an electrolyte solution in which a lithium salt is dissolved in a non-aqueous solvent mainly containing carbonic acid ester, carboxylic acid ester, ether, lactone and the like is used. These non-aqueous solvents are excellent solvents in terms of battery characteristics, such as high dielectric constant and high oxidation potential, and therefore excellent stability during battery use.

[0003]

On the other hand, the electrolytic solution using the non-aqueous solvent as described above can be used at a high voltage because of the high stability of the non-aqueous solvent. A so-called overcharge phenomenon, which is a voltage equal to or higher than a predetermined upper limit voltage at the time of charging, is likely to cause a problem. When overcharged, not only the deformation and heat generation of the battery, but in the worst case, ignition,
It is important to improve the safety of the secondary battery at the time of overcharging because it may cause a phenomenon such as bursting.

In particular, as a positive electrode active material of a lithium secondary battery, a lithium transition metal oxide having a layered structure, such as lithium cobalt oxide and lithium nickel oxide, is used because of its large capacity per weight. In overcharged state, these compounds become almost desorbed from lithium ions and become unstable, which may cause a rapid exothermic reaction with the electrolytic solution or deposit lithium metal on the negative electrode. Therefore, safety during overcharge is very important.

Conventionally, as an attempt to improve the safety during such overcharge, a method of adding an overcharge inhibitor to the electrolytic solution to cut off the current is known. For example, as an overcharge inhibitor, an aromatized compound such as biphenyl having an oxidation potential equal to or higher than the upper limit voltage value of the battery is added to the electrolytic solution, and when it becomes an overcharged state, the aromatized compound is added. There is known a method of suppressing the overcharging current and stopping the progress of overcharging by oxidative polymerization to form a high resistance film on the surface of the active material. (For example, Japanese Patent Application Laid-Open No. 9-106835) However, these aromatized compounds are susceptible to reduction and deteriorate the performance of the battery under conditions such as normal charge / discharge and storage at high temperature. was there.

[0006]

Means for Solving the Problems As a result of intensive studies made by the present inventors in order to achieve the object of improving the safety of a lithium secondary battery during overcharge, a non-aqueous electrolyte secondary battery As a non-aqueous electrolytic solution prepared by dissolving a lithium salt in a non-aqueous solvent containing a compound having a 1,2,3-oxadiazolium-5-oleate skeleton as the electrolytic solution of 1, the self-oxidation is caused during overcharge. In order to complete the present invention, it has been found that it has the capability of stopping the progress of overcharging, and that the performance deterioration of the battery under conditions such as normal charge / discharge and high temperature storage can be kept within an allowable range. I arrived.

That is, the gist of the present invention is a non-aqueous electrolyte solution in which a lithium salt is dissolved in a non-aqueous solvent, wherein the non-aqueous solvent is a compound having a 1,2,3-oxadiazolium-5-oleate skeleton. A non-aqueous electrolyte solution for a lithium secondary battery, which comprises: Another aspect of the present invention is to provide a negative electrode containing metallic lithium, a lithium alloy, or a material capable of occluding and releasing lithium, a positive electrode containing a material capable of occluding and releasing lithium, and a lithium salt. In a lithium secondary battery comprising a non-aqueous electrolyte solution dissolved in a non-aqueous solvent, the non-aqueous solvent is 1,
A lithium secondary battery comprising a compound having a 2,3-oxadiazolium-5-oleate skeleton.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. Examples of the non-aqueous solvent used in the non-aqueous electrolyte solution for a lithium secondary battery of the present invention include cyclic carbonates, lactone compounds, chain carbonates, carboxylic acid esters, chain ethers and the like. Of these, cyclic carbonates and lactone compounds are preferable.

Examples of the cyclic carbonate include ethylene carbonate, propylene carbonate and butylene carbonate. As the lactone compound, γ-
Butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, δ-caprolactone, ε-
Examples include caprolactone.

Examples of chain carbonates include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, di-n-butyl carbonate, diisobutyl carbonate, di-t-butyl carbonate and n-. Butyl isobutyl carbonate, n-butyl-t-butyl carbonate, isobutyl-t-butyl 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, n-butyl-n-propyl carbonate, isobutyl-n-propyl carbonate, t-butyl-n-propyl carbonate, n-butyl isopropyl carbonate, isobutyl isopropyl carbonate , T-butyl isopropyl carbonate, and the like. Among them, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are preferable.

As the carboxylic acid ester, methyl acetate, ethyl acetate, acetic acid-n-propyl acetate, isopropyl acetate, acetic acid-n-butyl acetate, isobutyl acetate, acetic acid-t-
Butyl, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, n-butyl propionate, isobutyl propionate, t-butyl propionate and the like, among which ethyl acetate, propione Methyl acid and ethyl propionate are preferred.

Examples of the chain ether include dimethoxymethane, dimethoxyethane, diethoxymethane, diethoxyethane, ethoxymethoxymethane and ethoxymethoxyethane, and among them, dimethoxyethane and diethoxyethane are preferable. These solvents are usually used so as to account for 0.1 to 99.9% by weight of the non-aqueous solvent.

In the present invention, the non-aqueous solvent contains a compound having a 1,2,3-oxadiazolium-5-oleate skeleton. Examples of compounds having a 1,2,3-oxadiazolium-5-oleate skeleton that have been synthesized so far include 3-methyl-1,2,3-oxadiazolium-5-oleate and 3-methyl-1,2,3-oxadiazolium-5-oleate. Ethyl-1,2,3-oxadiazolium-5-oleate, 3-n-propyl-
1,2,3-oxadiazolium-5-oleate, 3,
4-di-n-propyl-1,2,3-oxadiazolium-5-oleate has been reported. Since the effect of the compound in the present invention is considered to be derived from the basic skeleton structure, any compound having the basic skeleton structure is considered to be effective. Among them, 3-methyl-1,2,3 -Oxadiazolium-5-oleate, 3
-Ethyl-1,2,3-oxadiazolium-5-oleate, 3-n-propyl-1,2,3-oxadiazolium-5-oleate, 3,4-di-n-propyl-1,
Alkyl-substituted compounds such as 2,3-oxadiazolium-5-oleate are more preferable, and further, 3-methyl-1,
2,3-oxadiazolium-5-oleate, 3-ethyl-1,2,3-oxadiazolium-5-oleate,
3-n-propyl-1,2,3-oxadiazolium-
A 3-monoalkyl-substituted compound such as 5-oleate is more preferable.

The compounds having the 1,2,3-oxadiazolium-5-oleate skeleton may be used alone or in combination of two or more, but the amount thereof present in the non-aqueous solvent is usually 0.1.
It is used so as to be 10 to 10% by weight, preferably 0.5 to 5% by weight. 1,2,3-oxadiazolium-5-
When the amount of the compound having an oleate skeleton is too small in the electrolytic solution, the effect of preventing overcharge is not sufficiently exhibited, but on the contrary, when it is too large, the battery characteristics may be adversely affected.

The non-aqueous electrolyte for lithium secondary batteries of the present invention may further contain known film-forming agents, overcharge inhibitors, dehydrating agents, deoxidizing agents and the like. Known film-forming agents include unsaturated cyclic carbonates such as vinylene carbonate; saturated cyclic carbonates having an alkenyl group such as vinylethylene carbonate; saturated cyclic carbonates having an aryl group such as phenylethylene carbonate; cyclic sulfur such as ethylene sulfite. Fight; Cyclic sultone such as propane sultone; Cyclic carboxylic acid anhydrides such as succinic anhydride, malonic anhydride, maleic anhydride, phthalic anhydride, etc., and one or more of these compounds may be used. it can. When such a film-forming agent is contained, the capacity retention characteristics and the cycle characteristics are better than when not containing them. The film-forming agent is preferably added to the non-aqueous solvent in an amount of 0.1 to 5% by weight.

Further, for example, Japanese Patent Laid-Open No. 8-203560.
No. 7-302614, No. 9-50822.
JP-A-8-273700, JP-A-9-17447
Benzene derivatives described in each publication, etc .;
-106835, JP-A-9-171840, JP-A-10-32258, JP-A-7-302614, JP-A-7-302614, and JP-A-11-162512.
And the derivatives thereof described in JP-A Nos. 2939469 and 2963898, and the like; Pyrrole derivatives described in JP-A 9-45369 and JP-A 10-32158; 7-
Aromatic compounds such as aniline derivatives described in JP-A-320778 and JP-A-7-302614; ether-based compounds described in JP 2983205 A; JP-A 2001-15158 If it contains an overcharge inhibitor such as
It can be expected that the effect of preventing the overcharged state is further improved as compared with the case where they are not included. Overcharge prevention agent,
The total amount of the compound including the 1,2,3-oxadiazolium-5-oleate skeleton is 0.1-10 in the non-aqueous solvent.
It is preferable to add it in an amount of 0.1% by weight.
It is more preferably 5% by weight.

A lithium salt is used as the solute of the non-aqueous electrolyte of the present invention. Any lithium salt can be used as long as it can be used as a solute. The following may be mentioned as specific examples of the lithium salt. (1) Inorganic lithium salt: LiPF ₆ , LiAsF ₆ , Li
_{BF 4, LiAlF 4, LiAlF 6} , inorganic fluoride salts LiSiF _6, etc., perhalogenate such as LiClO ₄ (2)
Organic lithium salt: Organic sulfonate such as LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ).
₂ , LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ) and other perfluoroalkyl sulfonic acid imide salts, LiC (CF ₃ S 2
O ₂ ) ₃ etc. perfluoroalkyl sulfonic acid methide salt,
LiPF ₃ (C ₂ F ₅ ) ₃ , LiBF ₂ (CF ₃ ) ₂ , LiB
LiB (CF ₃ CO), which is a salt obtained by substituting a part of fluorine of an inorganic fluoride salt such as F ₃ (CF ₃ ) with a perfluoroalkyl group.
O) ₄ , LiB (OCOCF ₂ COO) ₂ , LiB (OC
Lithium tetrakis (perfluorocarboxylate) borate salts such as OC ₂ F ₄ COO) ₂ .

These lithium salts may be used alone or in admixture of two or more. Among the above lithium salts, in terms of solubility, ionic dissociation degree, and electrical conductivity characteristics,
LiPF ₆ , LiBF ₄ , LiN (CF ₃ SO ₂ ) ₂ , L
iN (C ₂ F ₅ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) (C ₄ F ₉
SO ₂ ), LiPF ₃ (CF ₃ ) ₃ , LiPF ₃ (C
₂ F ₅ ) ₃ , LiBF ₂ (C ₂ F ₅ ) ₂ , LiB (OCOCF ₂
COO) ₂ is preferable, and LiPF ₆ or LiBF ₄ is more preferable. In particular, the non-aqueous solvent contains 60 gamma-butyrolactone.
When it is contained in an amount of not less than 50% by weight, LiBF ₄ is preferably not less than 50% by weight of the whole lithium salt.

The concentration of the lithium salt in the electrolytic solution is usually 0.
The electrolytic solution is prepared so as to be 5 to 3 mol / liter.
If the concentration is too low, the electric conductivity of the electrolytic solution becomes insufficient, and if the concentration is too high, the electric conductivity decreases due to an increase in viscosity, or the lithium salt tends to precipitate at low temperatures, resulting in battery performance. Will fall. Any material capable of inserting and extracting lithium can be used for the negative electrode of the lithium secondary battery of the present invention. Specific examples include thermal decomposition products of organic substances under various thermal decomposition conditions, carbonaceous materials such as artificial graphite and natural graphite; metal oxide materials; lithium metal; various lithium alloys.

Examples of the carbonaceous material include artificial graphite and purified natural graphite produced by subjecting easily graphitizable pitch obtained from various raw materials to high temperature heat treatment, and those obtained by subjecting these graphite to various surface treatments including pitch. preferable. As the graphite material, the lattice plane (002 plane) obtained by X-ray diffraction by the Gakushin method
The d value (interlayer distance) of is preferably 0.335 to 0.34 nm, more preferably 0.335 to 0.337 nm. The ash content is preferably 1% by weight or less, more preferably 0.5% by weight or less, still more preferably 0.1% by weight or less. The crystallite size (Lc) determined by X-ray diffraction by Gakshin method is preferably 30 nm or more, more preferably 50 nm or more,
Those having a thickness of 100 nm or more are more preferable. The median diameter measured by the laser diffraction / scattering method is preferably 1 to 100 μm, more preferably 3 to 50 μm, further preferably 5 to 40 μm, and particularly preferably 7 to 30 μm. B
The ET method specific surface area is 0.5 to 25.0 m ² / g,
0.7-20.0 m < ² > / g is preferable and 1.0-15.
0 m ² / g, and still more preferably those 1.5~10.0m ² / g. In Raman spectrum analysis using argon ion laser light, 1580 to 1620
Peak P _A (peak intensity I _A ) in the range of cm ⁻¹ and 1350
Peak P _B (peak intensity I _B ) in the range of ˜1370 cm ⁻¹
Intensity ratio R = I _B / I _A and is a 0 to 0.5, 158
The peak half-width in the range of ⁰ to 1620 cm ^-1 is 26 cm
^-1 or less is preferable, and 25 cm ^-1 or less is more preferable.

Further, as the carbonaceous material, a negative electrode material capable of inserting and extracting lithium can be mixed and used. As the negative electrode material capable of inserting and extracting lithium other than the carbonaceous material, Ag, Zn, Al, Ga, In, Si, Ge,
Sn, Pb, P, Sb, Bi, Cu, Ni, Sr, Ba
Alloys of such metals with Li; metal oxide materials such as oxides of these metals; lithium metals; among them, Sn oxides, Si oxides, Al oxides, lithium alloys of Sn, Si, Al, Lithium metal is preferred.

These negative electrode materials may be used alone or in combination of two or more. The negative electrode is manufactured by a usual method. For example, a negative electrode is manufactured by adding a binder, a thickener, a conductive material, a solvent, and the like to the negative electrode material to form a slurry, applying the slurry to the substrate of the current collector, and drying.
Further, the negative electrode material may be roll-formed as it is to form a sheet electrode, or compression-molded to form a pellet electrode.

Any binder, thickener and conductive material may be used as long as they are stable with respect to the solvent used in the production of the electrode, the electrolytic solution and other materials used in the battery. Usually, polyvinylidene fluoride, polytetrafluoroethylene, styrene-butadiene rubber, isoprene rubber, butadiene rubber and the like are used as the binder.
As the thickener, carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and the like are used.

As the conductive material, a metal material such as copper or nickel; a conductive carbonaceous material such as graphite or carbon black is used. Examples of the material of the current collector include metals such as copper, nickel and stainless steel.
Copper foil, which is easy to process into a thin film and inexpensive, is preferable. For the positive electrode of the battery, lithium transition metal composite oxides such as lithium cobalt oxide, lithium nickel oxide, and lithium manganese oxide, as well as various known materials capable of occluding and releasing lithium can be used. Further, the positive electrode can be manufactured according to the above-mentioned negative electrode.

As the material of the positive electrode current collector, a metal such as aluminum, titanium, tantalum, or an alloy thereof is used. Among these, aluminum or its alloy is preferable. As the separator for separating the positive electrode and the negative electrode of the battery, as long as it is stable to the electrolytic solution and has sufficient liquid retention,
Any one can be used. For example, porous sheets and non-woven fabrics made of polyolefin such as polyethylene and polypropylene are used.

The production of the lithium secondary battery of the present invention can be appropriately selected from the methods used in ordinary non-aqueous electrolyte secondary batteries. The battery can be of any shape commonly used. For example, a cylinder type in which a sheet electrode and a separator are formed in a spiral shape, a cylinder type in which an inside-out structure is combined with a pellet electrode and a separator, and a coin type in which pellet electrodes and a separator are stacked are listed.

[0027]

EXAMPLES Examples and comparative examples of the present invention will be described below.
The specific embodiment will be further described, but the present invention is beyond the gist thereof.
Unless otherwise stated, it is limited by these examples.
There is no. [Production of Positive Electrode] LiCoO 2 as a positive electrode active material₂85 weight
6% by weight of carbon black, polyvinylidene fluoride
(Kureha Chemical Co., Ltd., trade name: KF-1000) 9% by weight
Add and mix, disperse with N-methyl-2-pyrrolidone,
The thickness of the slurry is 20 μm, which is the positive electrode current collector.
1 aluminum foil is evenly coated and dried, then diameter 1
It was punched into a 2.5 mm disk shape to obtain a positive electrode. [Fabrication of Negative Electrode] Of the lattice plane (002 plane) in X-ray diffraction
d value is 0.336 nm, crystallite size (Lc) is 100 n
m or more (264 nm), ash content 0.04% by weight, laser
ー Median diameter of 17μm by diffraction / scattering method, BET method
Specific surface area is 8.9m²/ G, Argon ion laser light
1580-16 in Raman spectrum analysis using
20 cm^-1Range peak P_A(Peak intensity I_A)and
1350-1370 cm ^-1Range peak P_B(peak
Strength I_B) Intensity ratio R = I_B/ I_AIs 0.15, 1580
~ 1620 cm^-1Of the peak in the range of 22.2c
m^-1Artificial graphite powder (manufactured by Timcal, trade name: K
S-44) Styrene dispersed in 94% by weight of distilled water
Butadiene rubber (SBR) is 6% by weight in solid content
Seaweed and mixed with a disperser to make a slurry
Evenly distribute the material on the 18 μm thick copper foil, which is the negative electrode current collector.
After coating and drying, punch out into a disk shape with a diameter of 12.5 mm.
Then, an electrode was prepared and used as a negative electrode. [Fabrication of coin type cell] Positive electrode, negative electrode and non-aqueous electrolyte solution
To the stainless steel can body that also serves as the positive electrode conductor.
Polyethylene containing a pole and impregnated with electrolyte on it
The negative electrode was placed via the separator made of. With this can
A sealing plate that also serves as the negative electrode conductor, and a gasket for insulation
It was caulked and sealed through to prepare a coin cell. [Evaluation of coin type cell] End-of-charge voltage at 25 ° C
4.2V, 0.5V constant current at discharge end voltage 2.5V
Charge / discharge test is performed and the discharge capacity in the second cycle is changed to 2 cycles.
The value divided by the charge capacity of the second cycle is the charge and discharge efficiency of the second cycle.
did.

A value obtained by charging the battery under the same conditions after 4 cycles, storing it at 85 ° C. for 72 hours in the charged state, then discharging it, and dividing the discharge capacity after storage after 4 cycles by the charge capacity at the 4th cycle. Was the storage property. Also, from the fully charged state, a charging current of 5 mA is further passed, and the capacity at the time of normal full charging is set to 100%, and overcharging is performed until a total of 170% of the amount of electricity has flowed (depth of charge 170%). Done,
The voltage at that time was measured. [Example 1] Ethylene carbonate and diethyl carbonate in a weight ratio of 1: lithium hexafluorophosphate was thoroughly dried under a dry argon atmosphere mixed solvent to 1 (LiPF ₆₎ of 1 mol / liter as a solute Dissolve in a proportion, further dissolve 3-ethyl-1,2,3-oxadiazolium-5-oleate in a proportion of 2% by weight, and further dissolve vinylene carbonate as a negative electrode film forming agent in a proportion of 2% by weight. An electrolytic solution was prepared by using the above method, and a coin-type cell was prepared by the above method, and the initial charge / discharge efficiency and storage characteristics were evaluated. [Example 2] LiPF ₆ was added to a solvent prepared by mixing ethylene carbonate and diethyl carbonate at a weight ratio of 1: 1.
It is dissolved at a ratio of mol / liter, and further 3-methyl-1,
Evaluation was performed in the same manner as in Example 1 except that an electrolytic solution prepared by dissolving 2,3-oxadiazolium-5-olate and vinylene carbonate in a proportion of 2% by weight based on the weight of the electrolytic solution was used. It was [Example 3] LiPF ₆ was added to a solvent prepared by mixing ethylene carbonate and diethyl carbonate at a weight ratio of 1: 1.
It was prepared by dissolving at a ratio of mol / liter, and further dissolving 3-n-propyl-1,2,3-oxadiazolium-5-olate and vinylene carbonate at a ratio of 2% by weight based on the weight of the electrolytic solution. Evaluation was performed in the same manner as in Example 1 except that the electrolytic solution was used. [Example 4] Ethylene carbonate and diethyl carbonate in a weight ratio of 1: solvent lithium tetrafluoroborate mixed to 1 (LiBF ₄₎ was dissolved in a proportion of 1 mol / liter, more 3-ethyl-1,2 Evaluation was conducted in the same manner as in Example 1 except that an electrolytic solution prepared by dissolving 2,3-oxadiazolium-5-olate and vinylene carbonate in a proportion of 2% by weight based on the weight of the electrolytic solution was used. . Comparative Example 1 LiPF ₆ was dissolved in a solvent in which ethylene carbonate and diethyl carbonate were mixed at a weight ratio of 1: 1 at a ratio of 1 mol / liter, and vinylene carbonate was mixed at a ratio of 2% by weight with respect to the weight of the electrolytic solution. Evaluation was performed in the same manner as in Example 1 except that the electrolytic solution prepared by dissolution was used. [Comparative Example 2] LiBF ₄ was dissolved in a solvent in which ethylene carbonate and diethyl carbonate were mixed at a weight ratio of 1: 1 at a ratio of 1 mol / liter, and vinylene carbonate was mixed at a ratio of 2% by weight with respect to the weight of the electrolytic solution. Evaluation was performed in the same manner as in Example 1 except that the electrolytic solution prepared by dissolution was used. [Comparative Example 3] LiPF ₆ was dissolved in a solvent in which ethylene carbonate and diethyl carbonate were mixed at a weight ratio of 1: 1 at a ratio of 1 mol / liter, and biphenyl and vinylene carbonate were each contained in an amount of 2% by weight based on the weight of the electrolytic solution. Evaluation was performed in the same manner as in Example 1 except that the electrolytic solution prepared by dissolving in the ratio of was used.

Table 1 shows the results of these evaluations.

[0030]

[Table 1]

[0031]

The lithium secondary battery using the non-aqueous electrolyte for a lithium secondary battery of the present invention has high charge / discharge efficiency, excellent capacity retention characteristics, excellent battery characteristics and safety in a wide temperature range, And it has a high energy density.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01M 4/58 H01M 4/58 (72) Inventor Makoto Ue 3-1, Chuo 8-chome, Ami-machi, Inashiki-gun, Ibaraki No. Mitsubishi Chemical Co., Ltd. F-term (reference) 5H029 AJ02 AJ03 AJ12 AK03 AL02 AL07 AL12 AM02 AM03 AM04 AM05 AM07 BJ03 BJ12 DJ17 HJ01 HJ13 5H050 AA02 AA08 AA15 BA17 CA08 CA09 CB02 CB07 CB08 CB12 HA01 HA13

Claims (11)

[Claims] 1. A non-aqueous electrolytic solution in which a lithium salt is dissolved in a non-aqueous solvent, wherein the non-aqueous solvent contains a compound having a 1,2,3-oxadiazolium-5-oleate skeleton. A characteristic non-aqueous electrolyte solution for lithium secondary batteries. 2. The non-aqueous solvent contains 0.1 to 99.9% by weight of at least one organic solvent selected from the group consisting of cyclic carbonates, lactone compounds, chain carbonates, carboxylic acid esters and chain ethers. Claim 1
Non-aqueous electrolyte for lithium secondary battery according to 3. The non-aqueous electrolyte solution for a lithium secondary battery according to claim 2, wherein the cyclic carbonate is at least one selected from the group consisting of butylene carbonate, propylene carbonate and ethylene carbonate. 4. The lactone compound is at least one selected from the group consisting of γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, δ-caprolactone and ε-caprolactone. 3. The non-aqueous electrolyte solution for lithium secondary battery according to item 3. 5. The non-aqueous solvent contains 0.1 to 5 of at least one compound selected from the group consisting of vinylene carbonate, ethylene sulfite, vinyl ethylene carbonate, propane sultone, phenyl ethylene carbonate and cyclic carboxylic acid anhydride. Content of 1% by weight,
4. The non-aqueous electrolyte solution for a lithium secondary battery according to any one of 4 above. 6. The lithium salt is LiPF ₆ , LiBF ₄ ,
_{LiCF 3 SO 3, LiN (CF} 3 SO 2) 2, LiN
(C ₂ F ₅ SO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO
₂ ), LiPF ₃ (C ₂ F ₅ ) ₃ and LiB (CF ₃ COO)
_The non-aqueous electrolyte solution for lithium secondary batteries according to claim 1, which is at least one selected from the group consisting of ₄ . 7. The non-aqueous solvent contains 0.1 to 1 of a compound having a 1,2,3-oxadiazolium-5-oleate skeleton.
The non-aqueous electrolyte solution for lithium secondary batteries according to any one of claims 1 to 6, which contains 0% by weight. 8. A negative electrode containing metallic lithium, a lithium alloy, or a material capable of inserting and extracting lithium,
A lithium secondary battery comprising a positive electrode containing a material capable of inserting and extracting lithium, and a non-aqueous electrolyte solution in which a lithium salt is dissolved in a non-aqueous solvent, wherein the non-aqueous electrolyte solution is 7. A lithium secondary battery, which is the non-aqueous electrolyte solution for a lithium secondary battery according to any of 7. 9. The negative electrode has a lattice plane (00
At least one selected from the group consisting of a carbon material having a d value on the second surface) of 0.335 to 0.34 nm and an oxide of at least one metal selected from the group consisting of Sn, Si, and Al, and a lithium alloy. Claim 8 which includes.
The lithium secondary battery described in. 10. The lithium secondary battery according to claim 8, wherein the positive electrode contains a lithium transition metal composite oxide. 11. The lithium secondary battery according to claim 10, wherein the positive electrode contains at least one lithium-transition metal composite oxide selected from the group consisting of lithium cobalt oxide, lithium nickel oxide, and lithium manganese oxide. Next battery.