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:
Sep. 28, 1999
Filed:
Mar. 26, 1997
Yoshitsugu Kojima, Aichi, JP;
Akihiko Koiwai, Aichi, JP;
Nobuaki Suzuki, Aichi, JP;
Satoru Yamamoto, Aichi, JP;
Kabushiki Kaisha Toyota Chuo Kenkyusho, Aichi-ken, JP;
Abstract
A negative electrode material capable of absorbing and desorbing lithium is comprised of a mixture of coke and graphite. The amount of graphite in the mixture is near to that which induces percolation transition. Preferably, the amount of graphite in the mixture is 2 to 37 wt % relative to the total amount of the coke and graphite. The coke may be prepared by heating raw coke from oil or coal at 500 to 900.degree. C. The coke may be 0.06 or more in the atomic ratio of hydrogen to carbon and 0.003 or more in the atomic ratio of oxygen to carbon. The graphite may be 0.5 .mu.m to 30 .mu.m in a mean particle size. Lithium secondary batteries comprising the negative electrodes have a large discharge capacity.