HYDROGEN-STORAGE ALLOY, PROCESS FOR PRODUCING THE SAME, HYDROGEN-STORAGE ALLOY ELECTRODE, AND SECONDARY CELL

摘要

A hydrogen-storage alloy whose chemical composition contains a phase represented by the general formula A_5-xB_1+xC₂₄, wherein A is one or more elements selected among the rare earth elements; B is one or more elements selected from the group consisting of Mg, Ca, Sr, and Ba; C is one or more elements selected from the group consisting of Ni, Co, Mn, Al, Cr, Fe, Cu, Zn, Si, Sn, V, Nb, Ta, Ti, Zr, and Hf; and x is a number in the range of -0.1 to 0.8, the phase having a crystal structure which belongs to the space group R-3m and has lattice constants in which the ratio of the c-axis length to the a-axis length is 11.5-12.5.