Lithium secondary battery

• US 5,432,029 A
• Filed: 05/13/1994
• Issued: 07/11/1995
• Est. Priority Date: 05/14/1993
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Nishimura, Naoto, Yamada, Kazuo, Mitate, Takehito, Okamoto, Hiroshi, Yoneda, Tetsuya, Umemoto, Akimasa
• Primary Examiner(s): Skapars, Anthony
• Application Number:
  US08/242,106
• Time in Patent Office: 424 Days
• Field of Search: 429/194, 429/197, 429/217, 429/218, 429/220, 252/182.1
• US Class Current: 429/338
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 4/36 Selection of substances as active materials, active masses, active liquids
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

The lithium secondary battery includes a positive electrode, a nonaqueous ion conductive medium, and a negative electrode, and the negative electrode includes as a main constituent graphite which permits intercalation and deintercalation of lithium ions, together with copper oxide and a binder.

Claims

1. A lithium secondary boundary, comprising a positive electrode, a nonaqueous ion conductive medium, and a negative electrode,

said negative electrode including as a main constituent graphite which permits intercalation and deintercalation of lithium ions, together with copper oxide, and a binder.

2. A lithium secondary battery as recited in claim 1, wherein the particle size of said graphite is at most 80 μ

m.

3. A lithium secondary battery as recited in claim 1, wherein the weight ratio of said graphite and said copper oxide is in the range from 9.8:

0.2 to 6;

4.

4. A lithium secondary battery as recited in claim 1, wherein said copper oxide is copper (II) oxide.

5. A lithium secondary battery as recited in claim 1, wherein

said binder includes at least one selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyolefin based polymer, and synthetic rubber.

6. A lithium secondary battery as recited in claim 1, wherein

the weight ratio of the total of said graphite and said copper oxide, and said binder is in the range from 99:

1 to 70;

30.

7. A lithium secondary battery as recited in claim 1, wherein

mean interval for (002) planes of said graphite is in the range from 0.335 to 0.340 nm.

8. A lithium secondary battery as recited in claim 1, wherein

said graphite has a value of at most 0.4 as the intensity ratio of a peak in the vicinity of 1360 cm^-1 relative to a peak in the vicinity of 1580 cm^-1 in argon laser Raman scattering.

9. A lithium secondary battery as recited in claim 1, wherein

said nonaqueous ion conductive medium includes at least ethylenecarbonate.

10. A lithium secondary battery as recited in claim 9, wherein

said nonaqueous ion conductive medium includes ethylenecarbonate and at least one element selected from the group consisting of ester family such as propylene carbonate, butylene carbonate, diethylcarbonate, dimethylcarbonate, methylethylcarbonate, and γ

-butylolactone;

ether family such as substituent tetrahydrofuran such as tetrahydrofuran and 2-methyltetrahydrofuran, dioxolane, dimethyl ether, dimethoxyethane, diethoxyethane, and methoxyethoxy ethane;

dimethyl sulfoxide;

sulfolane; and

methylsulfolane;

acetonitrile;

methyl formate; and

methyl acetate.

11. A lithium secondary battery, comprising a positive electrode, a nonaqueous ion conductive medium, and a negative electrode,

said negative electrode including as a main constituent graphite particles which permit intercalation and deintercalation of lithium ions, together with copper oxide coating the surface of at least part of said graphite particles.

12. A lithium secondary battery as recited in claim 11, wherein

said graphite articles have a particle size of at most 80 μ

m.

13. A lithium secondary battery as recited in claim 11, wherein the weight ratio of said graphite and copper contained in said copper oxide is in the range from 98.5:

1.5 to 62;

38.

14. A lithium secondary battery as recited in claim 11, wherein

said copper oxide is copper (II) oxide.

15. A lithium secondary battery as recited in claim 11, wherein said binder includes at least one selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyolefin based polymer, and synthetic rubber.

16. A lithium secondary battery as recited in claim 11,

the weight ratio of the total of said graphite and said copper oxide and said binder is in the range from 99:

1 to 70;

30.

17. A lithium secondary battery as recited in claim 11, wherein

mean interval for (002) planes of said graphite is in the range from 0.335 to 0.340 nm.

18. A lithium secondary battery as recited in claim 11, wherein

said graphite has a value of at most 0.4 as the intensity ratio of a peak in the vicinity of 1360 cm^-1 relative to a peak in the vicinity of 1580 cm^-1 in argon laser Raman scattering.

19. A lithium secondary battery as recited in claim 11, wherein

said nonaqueous ion conductive medium includes at least ethylenecarbonate.

20. A lithium secondary battery as recited in claim 19, wherein

said nonaqueous ion conductive medium includes ethylenecarbonate and at least one element selected from the group consisting of ester family such as propylene carbonate, butylene carbonate, diethylcarbonate, dimethylcarbonate, methylethylcarbonate, and γ

-butylolactone;

ether family such as substituent tetrahydrofuran such as tetrahydrofuran and 2-methyltetrahydrofuran, dioxolane, dimethyl ether, dimethoxyethane, diethoxyethane, and methoxyethoxy ethane;

dimethyl sulfoxide;

sulfolane;

methylsulfolane;

acetonitrile;

methyl formate; and

methyl acetate.