Hydrogen storage alloy

Abstract

A hydrogen storage alloy having a body-centered cubic structure phase capable of storing and releasing hydrogen as its main phase, and a composition of the general composition formula: Ti (100-a-0.4b) Cr (a-0.6b) M b , wherein M is at least one element of Mo and W; and 20≦a(at %)≦80 and 0≦b (at %)<5.

1 . A hydrogen storage alloy having the following characteristics: 
 (1) it has as its main phase a body-centered cubic structure phase capable of absorbing, storing and releasing hydrogen, and    (2) it has a composition of the following general composition formula:    Ti (100-a-0.4b) Cr (a-0.6b) M b       wherein m is at least one element of molybdenum (Mo) and tungsten (w); and 20≦a(at %)≦80 and 0≦b(at %)<5.    
     
     
         2 . The hydrogen storage alloy according to  claim 1  wherein the atom % of Mo and/or W is within a range of 3±1.5 at %.  
     
     
         3 . The hydrogen storage alloy according to  claim 1  or  2  which contains an element X having an atomic radius larger than Cr and smaller than Ti, at a range of 0≦d(at %)≦20, provided that d is an atom % concentration (at %) of X.  
     
     
         4 . The hydrogen storage alloy according to any of  claims 1  to  3  which contains at least one or more elements (T) selected from Nb, Ta, Mn, Fe, Al, B, C, Co, Cu, Ga, Ge, Ln (various lanthanoid metals), N, Ni, P and Si are contained at a range of 0≦e(at %)≦10, provided that e is an atom % concentration (at %) of T.