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. 20, 2004
Filed:
Jan. 04, 2002
Michio Takahashi, Nagoya, JP;
NGK Insulators, Ltd., Nagoya, JP;
Abstract
A lithium secondary battery using a lithium manganese oxide for a positive active material having a cubic spinel structure which has a crystallite size of 58 nm or greater and/or a lattice distortion of 0.09% or less. The ratio of Li/Mn in the lithium manganese oxide is preferably greater than 0.5. In synthesizing the lithium manganese oxide, a mixed compound including salts and/or oxides of each of the elements is fired in an oxidizing atmosphere in a range of 650° C. to 1000° C. for 5 to 50 hours, with the properties of the crystal being improved by firing two or more times, preferably with an increase in firing temperature over the temperature of the previous firing.