Hydrogen-absorbing alloy for alkaline storage battery, and alkaline storage battery

Abstract

A hydrogen-absorbing alloy for alkaline storage battery which is produced by a rapid cool using a rapid quenching method and whose component is represented by a general formula Ln1-xMgxNia-b-cAlbZc is used for a negative electrode of an alkaline storage battery.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view illustrating an alkaline storage battery, fabricated in Examples and Comparative Examples of the invention.

FIG. 2 is a schematic cross-sectional view illustrating a test cell using a hydrogen-absorbing alloy for alkaline storage battery for its negative electrode fabricated in Example 4 and Comparative Examples 1 and 5 of the invention.

Claims

1. A hydrogen-absorbing alloy for alkaline storage battery which is produced by a rapid cool using a rapid quenching method having a composition represented by a general formula Ln1-xMgxNia-b-cAlbZc where Ln is at least an element selected from rare earth elements including Y, Zr, and Z is at least one element selected from the group consisting of V, Nb, Ta, Cr, Mo, Mn, Fe, Co, Ga, Zn, Sn, In, Cu, Si, P, and B, 0.05≦x<0.25, 2.8≦a≦3.9, 0<b≦0.30, and 0≦c≦0.25.

2. The hydrogen-absorbing alloy for alkaline storage battery according to claim 1, wherein x in the above formula satisfies 0.05≦x≦0.20.

3. The hydrogen-absorbing alloy for alkaline storage battery according to claim 1, wherein (x+b), a total amount of x and b in the above formula is not less than 0.30.

4. The hydrogen-absorbing alloy for alkaline storage battery according to claim 2, wherein (x+b), a total amount of x and b in the above formula is not less than 0.30.

5. The hydrogen-absorbing alloy for alkaline storage battery according to claim 1 subjected to a heat treatment at a temperature which is 25° C. to 70° C. lower than a liquefy beginning temperature Tm, after being rapidly cooled by the rapid quenching method.

6. The hydrogen-absorbing alloy for alkaline storage battery according to claim 2 subjected to a heat treatment at a temperature which is 25° C. to 70° C. lower than a liquefy beginning temperature Tm, after being rapidly cooled by the rapid quenching method.

7. The hydrogen-absorbing alloy for alkaline storage battery according to claim 3 subjected to a heat treatment at a temperature which is 25° C. to 70° C. lower than a liquefy beginning temperature Tm, after being rapidly cooled by the rapid quenching method.

8. An alkaline storage battery comprising: a positive electrode; a negative electrode using a hydrogen-absorbing alloy; and an alkaline electrolyte, characterized in that the negative electrode uses the hydrogen-absorbing alloy for alkaline storage battery according to claim 1.