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:
Feb. 05, 2002
Filed:
Oct. 26, 1999
Naoto Torata, Kashihara, JP;
Takehito Mitate, Yamatotakada, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A process for producing a positive electrode active material for a nonaqueous secondary battery comprising the steps of: dissolving compounds capable of providing lithium ions, nickel ions and optionally ions of at least one element selected from the group consisting of transition metals,-3B-group elements, 4B-group elements and 5B-group elements in a buffer solution containing at least lithium ions, thereby to prepare a starting aqueous solution; adding an oxalic acid to the starting aqueous solution to form a precipitate of oxalates of said ions and separating the precipitate; calcining the resulting precipitate to produce LiNI M O , wherein 0≦X<0.5 and M is at least one element selected from the group consisting of the transition metals, 3B-group elements, 4B-group elements and 5B-group elements; and re-using a residual liquid after the precipitate is separated for preparing the starting aqueous solution.