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. 18, 2006
Filed:
Dec. 31, 2002
Teruhiko Imoto, Kaizuka, JP;
Masutaka Ouchi, Kuzatsu, JP;
Yohei Hirota, Itano-gun, JP;
Kikuko Kato, Hirakata, JP;
Nobuyuki Higashiyama, Ikeda, JP;
Mamoru Kimoto, Hirakata, JP;
Shin Fujitani, Kobe, JP;
Koji Nishio, Kyoto, JP;
Teruhiko Imoto, Kaizuka, JP;
Masutaka Ouchi, Kuzatsu, JP;
Yohei Hirota, Itano-gun, JP;
Kikuko Kato, Hirakata, JP;
Nobuyuki Higashiyama, Ikeda, JP;
Mamoru Kimoto, Hirakata, JP;
Shin Fujitani, Kobe, JP;
Koji Nishio, Kyoto, JP;
Sanyo Electric Co., Ltd., Moriguchi, JP;
Abstract
A method of producing a hydrogen storage alloy, for use in alkaline storage batteries, includes two steps. A first step involves preparing alloy particles having a CaCu-type crystal structure and the compositional formula MmNiCoMnM, wherein M represents at least one element selected from the group consisting of aluminum (Al) and copper (Cu), 3.0≦x≦5.2, 0≦y≦1.2, 0.1≦z≦0.9, and 4.4≦x+y+z≦5.4. A second step involves immersing the alloy particles in an acid treating solution containing a cobalt compound and a copper compound, each in the amount of 0.1 to 5.0% by weight based on the weight of the alloy particles, and an organic additive to remove oxide films from and to reductively deposit cobalt and copper on a surface of each alloy particle to form a surface region surrounding a bulk region and having a graded composition. When the sum in percentage of numbers of cobalt (Co) atoms and copper (Cu) atoms present in the surface region is given by a and that in the bulk region by b, the relationship a/b≧1.3 is satisfied.