LITHIUM SECONDARY BATTERY AND NON-AQUEOUS ELECTROLYTIC SOLUTION

• US 20080254367A1
• Filed: 11/30/2007
• Published: 10/16/2008
• Est. Priority Date: 10/03/2000
• Status: Active Grant

• Current Assignee: MU Ionic Solutions Corporation
• Original Assignee: UBE Industries Limited
• Inventors: ABE, Koji, MIYOSHI, Kazuhiro, HAMAMOTO, Toshikazu, UEKI, Akira
• Granted Patent: US 7,981,552 B2
• Time in Patent Office: Days
• US Class Current: 429/223
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0564 the electrolyte being constituted of organic materials only
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 2300/004 Three solvents
• CPC Class Codes: H01M 2300/0042 Four or more solvents
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The sudden generation of heat being frequently caused in the case of the overcharge of a lithium secondary cell which have a positive electrode comprising a composite metal oxide of lithium and cobalt or a composite metal oxide of lithium and nickel, a negative electrode comprising metallic lithium, a lithium alloy or a material capable of occluding and releasing lithium, and a nonaqueous electrolyte solution comprising a nonaqueous solvent and an electrolyte dissolved therein can be efficiently prevented by the addition, to the nonaqueous electrolyte solution, of an organic compound which, when the lithium secondary cell is overcharged, decomposes into a decomposition product capable of dissolving out the cobalt or nickel contained in the positive electrode and depositing it ion the negative electrode (for example, a tert-alkylbenzene derivative).

Claims

1. (canceled)

2. A lithium secondary battery comprising:

a positive electrode comprising a compound metal oxide comprising lithium and cobalt or nickel;

a negative electrode comprising a lithium metal, a lithium alloy or a material capable occluding and releasing lithium; and

a non-aqueous electrolyte solution comprising an electrolyte in a non-aqueous solvent, in which the non-aqueous electrolyte solution contains an organic compound in an amount of 0.1 to 10 weight %, said organic compound being a combination of a tert-alkylbenzene derivative and cyclohexylbenzene.

3. The lithium secondary battery of claim 2, wherein the tert-alkylbenzene derivative is selected from the group consisting of tert-pentylbenzene, 1-methyl-4-tert-pentylbenzene, 5-tert-pentyl-m-xylene, 1-ethyl-1-(methylpropyl)benzene, (1,1-di-ethylpropyl)benzene, 1,3-di-tert-pentylbenzene, and 1,4-di-tert-pentylbenzene.

4. The lithium secondary battery of claim 2, wherein the non-aqueous electrolyte solution contains the organic compound in an amount of 1 to 5 weight %.

5. The lithium secondary battery of claim 2, wherein the non-aqueous solvent comprises a combination of a cyclic carbonate and a linear carbonate.

6. The lithium secondary battery of claim 2, wherein the non-aqueous solvent comprises a combination of three cyclic carbonates and a linear carbonate.

7. The lithium secondary battery of claim 5, wherein the cyclic carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate and vinylene carbonate, and the linear carbonate is selected from the group consisting of dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate.

8. The lithium secondary battery of claim 6, wherein the cyclic carbonates are selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate and vinylene carbonate, and the linear carbonate is selected from the group consisting of dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate.

9. The lithium secondary battery of claim 2, wherein the negative electrode comprises carbonaceous material having a graphite crystal structure in which d₀₀₂ is in the range of 0.335 to 0.340 nm.

10. The lithium secondary battery of claim 2, wherein the electrolyte is selected from the group consisting of LiPF₆, LiBF₄, LiClO₄, LiN(SO₂CF₃)₂, LiN(SO₂C₂F₅)₂, LiC(SO₂CF₃)₃, LiPF₄(CF₃₎₂, LiPF₃(C₂F₅)₃, LiPF₃(CF₃₎₃, LiPF₃(iso-C₃F₇)₃, and LiPF₅(iso-C₃F₇).