Materials for hydrogen storage, hydride electrodes and hydride batteries

Abstract

The present invention discloses four main groups of hydrogen storage/hydride electrode materials for electrochemical applications as the active material of the negative electrode of a hydride battery. The compositions of these four groups are represented by the formulas: (1) Ti.sub.a Nb.sub.b Ni.sub.c R.sub.x D.sub.y Q.sub.p, (2) Ti.sub.a Hf.sub.b Ni.sub.c R.sub.x D.sub.y Q.sub.p, (3) Ti.sub.a Ta.sub.b Ni.sub.c R.sub.x D.sub.y Q.sub.p, (4) Ti.sub.a V.sub.b Ni.sub.c R.sub.x D.sub.y Q.sub.p, and its hydride thereof; where R is at least one element selected from the group consisting of B, Hf, Sc, Zn, Sb, W, Sn, N, O, Ge, Ga, P, S, and the alkali metals; D is at least one element selected from the group consisting of Mn, Cu, Si, Cr, and Mm, where Mm is the mischmetal; Q is least one element selected from the group consisting of C, Mg, Ca, Sr, Ba, Al, Si, V, Cr, Mn, Fe, Co, Cu, Zr, Mo, Ag, Pd, Y, Ta, La, Ce, and Mm, where Mm is the mischmetal; and where the atomic mole ratios: a, b, c, x, y and p are defined by: 0.10.ltoreq.a.ltoreq.0.85, 0.001.ltoreq.b.ltoreq.0.50, 0.02.ltoreq.c.ltoreq.0.85, 0.ltoreq.x.ltoreq.0.30, 0.ltoreq.y.ltoreq.0.30, 0.ltoreq.p.ltoreq.0.45, b+y<0.62, and a+b+c+x+y+p=1.00; and if present, Mm.ltoreq.12 at. %; preferably, 0.15.ltoreq.a.ltoreq.0.63, 0.01.ltoreq.b.ltoreq.0.38, 0.15.ltoreq.c.ltoreq.0.60, 0.ltoreq.0.15, 0.ltoreq.y.ltoreq.0.15 and 0.ltoreq.p.ltoreq.0.30.