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. 22, 2000
Filed:
Jul. 28, 1998
Yuukichi Kobayashi, Tokyo, JP;
Hidehiko Ohara, Yokohama, JP;
Kenji Watanabe, Kagawa, JP;
Kazuo Niwa, Kagawa, JP;
Mitsubishi Chemical Corporation, Tokyo, JP;
Abstract
A lithium secondary cell wherein a carbon material treated with a fluorinating agent and having substantially no C--F covalent bond, is used as an active material for negative electrode, provides a secondary cell having improved cell life. Further, a lithium secondary cell wherein a carbon material treated with a fluorinating agent and having an amount of fluorine extractable with an aqueous alkaline solution being at most 0.05 wt %, is used as an active material for negative electrode, or a lithium secondary cell wherein a carbon material treated with a fluorinating agent and containing lithium, is used as an active material for negative electrode, provides a secondary cell which is free from a problem of expansion of the casing during charging due to fluorine remaining in a small amount in the cell.