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:
Apr. 02, 2013
Filed:
Jun. 20, 2007
Ryo Sakai, Yokohama, JP;
Yasuhiro Shirakawa, Yokohama, JP;
Hajime Takeuchi, Yokohama, JP;
Yasumasa Ooya, Shizuoka-ken, JP;
Koshin Tanaka, Yokohama, JP;
Kazuki Amemiya, Fujieda, JP;
Shouta Endou, Yokohama, JP;
Ryo Sakai, Yokohama, JP;
Yasuhiro Shirakawa, Yokohama, JP;
Hajime Takeuchi, Yokohama, JP;
Yasumasa Ooya, Shizuoka-ken, JP;
Koshin Tanaka, Yokohama, JP;
Kazuki Amemiya, Fujieda, JP;
Shouta Endou, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A positive electrode active material for use in a non-aqueous electrolyte secondary cell comprises a powdery metal oxide (LiCoO, LiNiO, LiMnOor the like). When the positive electrode active material is classified with a classification precision index κ of 0.7 or greater so as to obtain a coarse powder having a classification ratio in a range of 0.1% to 5%, a ratio (B/A) of the content (B) of an impurity metal element in the coarse powder obtained by the classification to the content (A) of the impurity metal element in the powder before the classification is 1.5 or less. The contents of the impurity metal elements are compared with respect to Ca, Mn, Fe, Cr, Cu, Zn and the like (exclusive of the metal element constituting the powdery metal oxide). The positive electrode active material for a secondary cell serves to improve cell performance capabilities and production yields.