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. 11, 2001
Filed:
Nov. 19, 1999
Toshio Tamaki, Ibaraki-ken, JP;
Kazunori Ishigami, Ibaraki-ken, JP;
Petoca, Ltd., Tokyo, JP;
Abstract
There are disclosed graphite materials for a negative electrode used in a lithium secondary battery which graphite materials have an average specific surface area of 1.5 m,/gram to 5 m,/gram and comprise (A) milled graphite fibers which are produced by milling and graphitizing mesophase pitch-based carbon fibers, and which have an interplanar spacing of the graphite layer (d,) of at most 0.337 nm and a specific surface area of 0.8 m,/gram to 1.3 m,/gram; and (B) graphite materials which have an interplanar spacing of the graphite layer (d,) of at most 0.336 nm, a degree of graphitization (P,/P,) of at least 2.0 and a specific surface area of 2 m,/gram to 15 m,/gram, wherein the components (A) and (B) are mixed at a ratio (A)/(B) by weight of 90/10 to 50/50. The above graphite materials comprising the components (A) and (B), when used for a negative electrode in a lithium secondary battery, can enhance the performance of the battery and charge/discharge capacity thereof especially in a high load discharge.