Hydrogen storage alloy, hydrogen storage alloy electrode, secondary battery, and method for producing hydrogen storage alloy

Patent metadata

Field	Value
Publication number	US-9496550-B2
Application number	US-201514590613-A
Country	US
Kind code	B2
Filing date	Jan 6, 2015
Priority date	Aug 9, 2006
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

Provided is a hydrogen storage alloy which is characterized in that two or more crystal phases having different crystal structures are layered in a c-axis direction of the crystal structures. The hydrogen storage alloy is further characterized in that a difference between a maximum value and a minimum value of a lattice constant a in the crystal structures of the laminated two or more crystal phases is 0.03 Å or less.

First claim

The invention claimed is:

1. A hydrogen storage alloy containing two or more crystal phases having different crystal structures, wherein the two or more crystal phases are layered in the c-axis direction of the crystal structures and the hydrogen storage alloy has a composition defined by a general formula R1 d R2 e R4 f R5 g (wherein R1 is one or more kind elements selected from the group consisting of rare earth metals including Y; R2 is one or more kind elements selected from the group consisting of Mg, Ca, Sr, and Ba; R4 is one or more kind elements selected from the group consisting of Ni, Co, Cr, Fe, Cu, Zn, Si, Sn, V, Nb, Ta, Ti, Zr, and Hf; R5 is one or two elements selected from Mn and Al; and d, e, f, and g satisfy 8≦d≦19; 2≦e≦9; 73≦f≦79; 1≦g≦4; and d +e+f+g=100) and satisfies 3.53≦(B/A)≦3.80 and 0.0593(B/A)+1.59≦rA≦0.0063(B/A)+1.81 in the case (B/A) is defined as (f+g)/(d+e) and rA (Å) is defined as the average atomic radius of R1 and R2, wherein the two or more crystal phases layered in the c-axis direction of the crystal structures comprise a crystal phase having Pr 5 Co l9 type crystal structure and a crystal phase having Ce 5 Co 19 type crystal structure.

2. The hydrogen storage alloy according to claim 1 , wherein the R1 is one or more kind elements R1′ selected from the group consisting of Ce, Pr, Nd, Sm, and Y and La at La/R1′ ratio of 5 or less; R2 is Mg; the R4 is one or two elements selected from Ni and Co; the R5 is Al; and the d, e, f, and g satisfy 16≦d≦19; 2≦e≦5; 73≦f≦78; and 2≦g≦4.

Assignees

• Gs Yuasa Int Ltd
• Nat Inst Advanced Ind Science & Tech

Inventors

• Kakeya Tadashi
• Kanemoto Manabu
• Kuzuhara Minoru
• Ozaki Tetsuya
• Watada Masaharu
• Sakai Tetsuo

Classifications

• C22C1/0441

  Alloys based on intermetallic compounds of the type rare earth - Co, Ni · CPC title

• H01M10/345

  Gastight metal hydride accumulators · CPC title

• C22F1/10

  of nickel or cobalt or alloys based thereon · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/383

  Hydrogen absorbing alloys · CPC title