| 摘要 |
PROBLEM TO BE SOLVED: To increase the flatness characteristic of equilibrium pressure at the occlusion and release of hydrogen and also to reduce pressure difference by providing a specific composition consisting of Mg, La, two or more kinds among rare earth elements including Y, Ni, Co, and one or more elements selected from among Mn and other twelve elements. SOLUTION: The hydrogen storage alloy has a composition represented by general formula Mg(La1-bR1b)1-aNiXCoYM1Z [where R1 means two or more elements selected from rare earth elements including Y and Ce content based on the total content of R1 and La is regulated to <20 wt.%; M1 means one or more elements selected from Mn, Fe, V, Cr, Nb, Al, Ga, Zn, Sn, Cu, Si, P, and B; and 0.15<a<0.35, 0.55<=b<=0.95, 0<=Y<=1.5, 0<=Z<=0.2 and 2.9<X+Y+Z<3.5 are satisfied]. Because the secondary battery having a cathode containing this alloy can maintain high working voltage over a long period at electric discharge, discharge capacitance and charge-and-discharge cycle life can be improved. |
