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:
Jul. 31, 2001
Filed:
Apr. 10, 1996
Hidetoshi Honbo, Hitachi, JP;
Seiji Takeuchi, Hitachioota, JP;
Hideto Momose, Hitachi, JP;
Tatsuo Horiba, Hitachi, JP;
Yasushi Muranaka, Hitachinaka, JP;
Yoshito Ishii, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A carbon material is provided having a superior reversibility in lithium intercalation-deintercalation reaction, and a non-aqueous secondary battery is provided which uses the carbon material as an active material for a negative electrode, which has a high energy density and an excellent rapid charging and discharging characteristics. Graphite powder having a maximum particle diameter of less than 100 &mgr;m and an existing fraction of rhombohedral structure in the crystalline structure of less than 20% is used as an active material for the negative electrode of the non-aqueous secondary battery. The graphite powder can be obtained by pulverizing raw graphite with a jet mill, and subsequently treating the powder at a temperature equal to or higher than 900° C.