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:
Nov. 17, 1998
Filed:
Mar. 07, 1997
Yoshio Moriwaki, Hirakata, JP;
Yoichi Izumi, Habikino, JP;
Yasuharu Yamamura, Chigasaki, JP;
Hideo Kaiya, Chigasaki, JP;
Abstract
The present invention provides a method of producing a hydrogen storage alloy low in cobalt content which can restrains a decrease in cycle life characteristic and preservation characteristic of an alkaline storage battery when the alloy is used as a negative electrode. The method includes the following steps. An Mm-Ni system hydrogen storage alloy which has a crystal structure of CaCu.sub.5 and contains 15 atom % or less of cobalt is powdered to have an average particle diameter of 10-100 .mu.m. Then, the powdered alloy is immersed in a treatment solution at 80.degree.-130.degree. C., the treatment solution comprising an alkaline aqueous solution containing 10 g/l or more of lithium hydroxide and having a specific gravity of 1.1 or higher, and cobalt ions which is contained in the alkaline aqueous solution, thereby forming a layer containing nickel and cobalt in higher concentration than in the bulk of the powdered alloy onto the alloy surface.