Lithium secondary battery

• US 20060134517A1
• Filed: 12/15/2005
• Published: 06/22/2006
• Est. Priority Date: 12/17/2004
• Status: Abandoned Application

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Kamino, Maruo, Fukui, Atsushi, Sunagawa, Takuya, Sawa, Shouichirou
• Application Number:
  US11/300,373
• Publication Number:
  US 20060134517A1
• Time in Patent Office: Days
• US Class Current: 429/218.100
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 2004/028 Positive electrodes
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/1395 of electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• 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

Abstract

Charge-discharge cycle performance is improved in a lithium secondary battery utilizing a material containing silicon as a positive electrode active material. A lithium secondary battery includes a negative electrode (2) containing silicon as a negative electrode active material, a positive electrode (1) containing a lithium-transition metal composite oxide, and a non-aqueous electrolyte. Lithium carbonate is added in the positive electrode (1), and carbon dioxide is dissolved in the non-aqueous electrolyte.

Claims

1. A lithium secondary battery comprising:

a negative electrode containing silicon as a negative electrode active material;

a positive electrode containing a lithium-transition metal composite oxide as a positive electrode active material; and

a non-aqueous electrolyte, wherein

lithium carbonate is contained in the positive electrode, and carbon dioxide is dissolved in the non-aqueous electrolyte.

2. The lithium secondary battery according to claim 1, wherein the lithium carbonate in the positive electrode is uniformly mixed with the lithium-transition metal composite oxide.

3. The lithium secondary battery according to claim 1, wherein the amount of the lithium carbonate contained in the positive electrode is within the range of from 0.3 weight % to 5 weight % with respect to the lithium-transition metal composite oxide.

4. The lithium secondary battery according to claim 2, wherein the amount of the lithium carbonate contained in the positive electrode is within the range of from 0.3 weight % to 5 weight % with respect to the lithium-transition metal composite oxide.

5. The lithium secondary battery according to claim 1, wherein lithium carbonate is contained in the lithium-transition metal composite oxide and the total amount of the lithium carbonate contained in the lithium-transition metal composite oxide and the lithium carbonate separately contained in the positive electrode is within the range of from 0.3 weight % to 5 weight % with respect to the lithium-transition metal composite oxide.

6. The lithium secondary battery according to claim 2, wherein lithium carbonate is contained in the lithium-transition metal composite oxide and the total amount of the lithium carbonate contained in the lithium-transition metal composite oxide and the lithium carbonate separately contained in the positive electrode is within the range of from 0.3 weight % to 5 weight % with respect to the lithium-transition metal composite oxide.

7. The lithium secondary battery according to claim 5, wherein the lithium carbonate contained in the lithium-transition metal composite oxide exists in and near a surface of the lithium-transition metal composite oxide.

8. The lithium secondary battery according to claim 6, wherein the lithium carbonate contained in the lithium-transition metal composite oxide exists in and near a surface of the lithium-transition metal composite oxide.

9. The lithium secondary battery according to claim 1, wherein the positive electrode comprises a positive electrode current collector made of a conductive metal foil, and a mixture layer arranged on the positive electrode current collector and containing the positive electrode active material, the lithium carbonate, a positive electrode binder, and a positive electrode conductive agent.

10. The lithium secondary battery according to claim 2, wherein the positive electrode comprises a positive electrode current collector made of a conductive metal foil, and a mixture layer arranged on the positive electrode current collector and containing the positive electrode active material, the lithium carbonate, a positive electrode binder, and a positive electrode conductive agent.

11. The lithium secondary battery according to claim 1, wherein the negative electrode comprises a negative electrode current collector made of a conductive metal foil, and a mixture layer arranged on the negative electrode current collector and containing a binder and active material particles containing silicon and/or a silicon alloy.

12. The lithium secondary battery according to claim 2, wherein the negative electrode comprises a negative electrode current collector made of a conductive metal foil, and a mixture layer arranged on the negative electrode current collector and containing a binder and active material particles containing silicon and/or a silicon alloy.

13. The lithium secondary battery according to claim 11, wherein in the negative electrode, the mixture layer is sintered on a surface of the negative electrode current collector.

14. The lithium secondary battery according to claim 12, wherein in the negative electrode, the mixture layer is sintered on a surface of the negative electrode current collector.

15. The lithium secondary battery according to claim 1, wherein the amount of the carbon dioxide dissolved in the non-aqueous electrolyte is 0.01 weight % or greater.

16. The lithium secondary battery according to claim 2, wherein the amount of the carbon dioxide dissolved in the non-aqueous electrolyte is 0.01 weight % or greater.

17. The lithium secondary battery according to claim 3, wherein the amount of the carbon dioxide dissolved in the non-aqueous electrolyte is 0.01 weight % or greater.

18. The lithium secondary battery according to claim 4, wherein the amount of the carbon dioxide dissolved in the non-aqueous electrolyte is 0.01 weight % or greater.