Alloy powder for electrodes, negative electrode for nickel-hydrogen storage batteries using same and nickel-hydrogen storage battery

Patent metadata

Field	Value
Publication number	US-2018019469-A1
Application number	US-201615549679-A
Country	US
Kind code	A1
Filing date	Jan 25, 2016
Priority date	Mar 31, 2015
Publication date	Jan 18, 2018
Grant date	—

Abstract

Alloy powder for electrodes that includes particles of a hydrogen-absorbing alloy having an AB 2 type crystal structure. The hydrogen-absorbing alloy includes first elements that are located in an A site in the crystal structure and include Zr, and second elements that are located in a B site and include Ni and. Mn. The hydrogen-absorbing alloy includes a plurality of alloy phases having different Zr concentrations. In each of the alloy phases, the percentage of Zr in the first elements exceeds 70 atom %.

First claim

1 . Alloy powder for electrodes, comprising
particles of a hydrogen-absorbing alloy having an AB 2 type crystal structure, wherein
the hydrogen-absorbing alloy includes:
first elements located in an A site in the crystal structure and including Zr; and
second elements located in a B site in the crystal structure and including Ni and Mn,

the hydrogen-absorbing alloy includes a plurality of alloy phases having different Zr concentrations, and
in each of the plurality of alloy phases, a percentage of Zr in the first elements exceeds 70 atom %.

2 . The alloy powder for electrodes according to claim 1 , wherein
the plurality of alloy phases include a main phase and an auxiliary phase formed in the main phase.

3 . The alloy powder for electrodes according to claim 2 , wherein
in the main phase, an atom ratio (B/A ratio) of the second elements to the first elements is 1.90 to 2.40 inclusive.

4 . The alloy powder for electrodes according to claim 2 , wherein
a percentage R zp of Zr in the first elements in the main phase and a percentage R zs of Zr in the first elements in the auxiliary phase satisfy 1.00<R zp /R zs ≦1.50.

5 . The alloy powder for electrodes according to claim 2 , wherein
a surface area percentage of the auxiliary phase in a cross section of the hydrogen-absorbing alloy is 0.1 to 20% inclusive.

6 . The alloy powder for electrodes according to claim 2 , wherein
in the main phase, a molar ratio x of Ni to the first elements satisfies 0.90≦x≦1.50.

7 . The alloy powder for electrodes according to claim 2 , wherein
in the main phase, a molar ratio y of Mn to the first elements satisfies 0.40≦y≦1.10.

8 . The alloy powder for electrodes according to claim 1 , wherein
the first elements further include Ti.

9 . The alloy powder for electrodes according to claim 1 , wherein
the second elements further include Al.

10 . The alloy powder for electrodes according to claim 9 , wherein
a molar ratio z 1 of Al to the first elements satisfies 0.15≦z 1 ≦0.45.

11 . The alloy powder for electrodes according to claim 1 , wherein
the second elements further include at least one element selected from a set consisting of Co, Cr, Si, and V.

12 . The alloy powder for electrodes according to claim 1 , wherein
the alloy powder is activated by an alkali treatment.

13 . A negative electrode for nickel-hydrogen storage batteries, the negative electrode comprising, as a negative electrode active material, the alloy powder for electrodes according to claim 1 .

14 . A nickel-hydrogen storage battery comprising:
a positive electrode; the negative electrode according to claim 13 ; a separator interposed between the positive electrode and the negative electrode; and an alkaline electrolytic solution.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Ohyama Hideaki
• Kato Fumio
• Li Hai-Wen
• Akiba Etsuo
• Wang Guoliang

Classifications

• B22F1/12

  Metallic powder containing non-metallic particles (containing lubricating or binding agents or organic material B22F1/10) · CPC title

• H01M10/26

  Selection of materials as electrolytes · CPC title

• H01M4/24

  Electrodes for alkaline accumulators · CPC title

• C22C19/07

  based on cobalt · CPC title

• B22F2009/041

  by mechanical alloying, e.g. blending, milling · CPC title