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.
Patent No.:
Date of Patent:
Aug. 11, 1998
Filed:
Nov. 22, 1996
Hiroshi Ejiri, Kamisu-machi, JP;
Yoshinori Yamazaki, Kamisu-machi, JP;
Hideyuki Nakajima, Kamisu-machi, JP;
Yoshiyuki Nishimura, Kamisu-machi, JP;
Petoca, Ltd., Tokyo, JP;
Abstract
A negative electrode material for use in lithium-ion secondary batteries, comprising milled pitch-based graphite fibers (A) obtained by graphitization at 2400.degree. C. or higher and milled pitch-based carbon fibers (B) obtained by carbonization at 550.degree. to 1300.degree. C. In this negative electrode material, it is preferred that both the milled pitch-based graphite fibers (A) and the milled pitch-based carbon fibers (B) have an average particle size of 10 to 30 .mu.m, that the ratio of milled pitch-based carbon and graphite fibers having a particle size of 5 .mu.m or less to all the milled pitch-based carbon and graphite fibers is not greater than 10% by weight and that the milled pitch-based graphite fibers (A) and the milled pitch-based carbon fibers (B) are blended at a weight ratio (A/B) of 95/5 to 40/60. A negative electrode which has a large capacity at the time of having been stabilized, exhibits a high charge and discharge efficiency at the initial stage and is excellent in charge and discharge cycle characteristics can be provided by the blending of milled pitch-based carbon fibers with milled pitch-based graphite fibers.