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

Patent metadata

Field	Value
Publication number	US-9869007-B2
Application number	US-201615219753-A
Country	US
Kind code	B2
Filing date	Jul 26, 2016
Priority date	Aug 9, 2006
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

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, as a main produced phase, a crystal phase having Ce 5 Co 19 type crystal structure and a composition defined by a general formula La h R6 i R7 j Mg k R8 m , wherein R6 is one or more elements selected from the group consisting of rare earth metals including Y and excluding La, wherein R7 is one or more elements selected from the group consisting of Zr, Ti, Zn, and V, wherein R8 is one or more elements selected from the group consisting of Ni, Co, Mn, Al, Cu, Fe, Cr, and Si, and wherein h, j, k and m satisfy 2.6≦i≦5.1; 0.2≦j≦0.65; 2≦k≦5.5; 0.70≦h/(h+i)≦0.85; and h+i+j+k+m=100.

2. A hydrogen storage alloy electrode using the hydrogen storage alloy according to claim 1 as a hydrogen storage medium.

3. A secondary battery using the hydrogen storage alloy electrode according to claim 2 as a negative electrode.

4. A method for producing the hydrogen storage alloy according to claim 1 , comprising
a melting step of heat melting alloy raw materials at prescribed mixing ratio in inert gas atmosphere;
a cooling step of rapid solidification the melted alloy at a cooling speed of 1000° C./s or higher; and
an annealing step of further annealing the alloy subjected to the cooling step at 860° C. or higher and 1000° C. or lower in inert gas atmosphere in pressurized state,
resulting in the hydrogen storage alloy of claim 1 .

Assignees

• Gs Yuasa Int Ltd
• Aist

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

• C22C19/03 Primary

  based on nickel · CPC title

• Y10T428/12493

  Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] · CPC title

• C22F1/002

  by rapid cooling or quenching; cooling agents used therefor · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title