Abstract: An electrochemically active material consisting of a CaCu5 structure single-phase hydridable alloy with the formula MmNiaMKnbAlcCodCre in which Mm is a mischmetal containing at least 50 wt % La, where: 5.10≦(a+b+c+d+e), d≦0.55, and 0.03≦e≦0.1.