The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jan. 14, 2003

Filed:

Mar. 14, 2000
Applicant:
Inventors:

Koutaro Kobayashi, Okayama, JP;

Yoshimasa Koishikawa, Honjou, JP;

Kensuke Hironaka, Fukaya, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01M 4/58 ; H01M 4/74 ; H01M 6/00 ;
U.S. Cl.
CPC ...
H01M 4/58 ; H01M 4/74 ; H01M 6/00 ;
Abstract

A lithium secondary battery capable of improving high temperature cycle life characteristic effectively without decreasing discharge capacity. Amorphous carbon powder with a specific surface area of 10.0 m /g and a mean particle diameter of 7.0 &mgr;m is used as negative electrode active material and lithium manganate with a Li/Mn ratio of 0.58 is used as positive electrode active material. Since a surface area of the negative electrode active material layer is made large by setting the mean particle diameter of the amorphous carbon powder to 10 &mgr;m or less, the surface area of the negative electrode active material layer is sufficiently large that, even when inert coating is formed on the surface of the negative electrode due to manganese deposition caused by manganese elution from the positive electrode, high temperature cycle life characteristic can be improved without high temperature deterioration.


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