Patent ID: 7951326

Claim:
A hydrogen absorbing alloy containing a phase of a Pr 5 Co 19 crystal structure having a composition defined by a general formula A 4−w B 1+w C 19 wherein A denotes one or more elements selected from rare earth elements including Y (yttrium); B denotes an Mg element; C denotes one or more elements selected from the a group consisting of Ni, Co, Mn, and Al; and w denotes a numeral in a range from −0.1 to 0.8 and having a composition as a whole defined by a general formula R1 x R2 y R3 z wherein 15.8≦x≦17.8, 3.4≦y≦5.0, 78.8≦z≦79.6, and x+y+z=100; wherein R1 denotes one or more elements selected from rare earth elements including Y (yttrium); R2 denotes Mg; R3 denotes one or more elements selected from a group consisting of Ni, Co, Mn, and Al; the numeral Mn+Al in said z is 0.5 or higher; and the numeral of Al in said z is 4.1 or lower.