HYDROGEN-ABSORBING ALLOY AND NICKEL-HYDROGEN STORAGE BATTERY

The present invention aims to increase the discharge capacity and to improve the cycle life performance in a nickel-metal hydride rechargeable battery using a La-Mg-Ni based hydrogen-absorbing alloy as an active material of a negative electrode. The present invention provides a hydrogen-absorbing alloy represented by the general formula (1): Ml u Mg v Ca w M2 x Ni y M3 z ...(1) (wherein, M1 is one or more elements selected from rare earth elements; M2 is one or more elements selected from the group consisting of Group 3A elements, Group 4A elements, Group 5A elements, and Pd (excluding rare earth elements); M3 is one or more elements selected from the group consisting of Group 6A elements, Group 7A elements, Group 8 elements, Group 1B elements, Group 2B elements, and Group 3B elements (excluding Ni and Pd); u, v, w, x, y, and z are numbers satisfying, u + v + w + x + y + z = 100, 3.4 ¤ v ¤ 5.9, 0.8 ¤ w ¤ 3.1, 0 ¤ (x+z) ¤ 5, and 3.2 ¤ (y+z)/(u+v+w+x) ¤ 3.4), and a nickel-metal hydride rechargeable battery including a negative electrode containing the hydrogen-absorbing alloy.