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:
Jun. 10, 2003
Filed:
Dec. 26, 2000
Teruhiko Imoto, Tokushima, JP;
Masutaka Ouchi, Tokushima, JP;
Yohei Hirota, Tokushima, JP;
Kikuko Kato, Katano, JP;
Nobuyuki Higashiyama, Ikeda, JP;
Mamoru Kimoto, Hirakata, JP;
Shin Fujitani, Hirakata, JP;
Koji Nishio, Hirakata, JP;
Sanyo Electric Co., Ltd., Moriguchi, JP;
Abstract
A hydrogen storage alloy, for use in alkaline storage batteries, having a CaCu -type crystal structure and represented by the compositional formula MmNi Co Mn M (wherein M represents at least one element selected from the group consisting of aluminum (Al) and copper (Cu); x is a nickel (Ni) stoichiometry and satisfies 3.0≦x≦5.2; y is a cobalt (Co) stoichiometry and satisfies 0≦y≦1.2; z is a manganese (Mn) stoichiometry and satisfies 0.1≦z≦0.9; and the sum of x, y and z satisfies 4.4≦x+y+z≦5.4). The hydrogen storage alloy includes a bulk region having a CaCu -type crystal structure and a substantially uniform composition and a surface region surrounding said 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.