Hydrogen storage alloy electrode and method for manufacturing the same

A method for manufacturing a hydrogen storage alloy electrode comprising the steps of:

• (A) plating nickel or applying nickel powder onto the surface of a hydrogen storage alloy powder, or mixing a hydrogen storage alloy powder with a nickel carbonyl-containing gas and thermally decomposing the gas to apply nickel onto the surface of the alloy powder, and
• (B) heating said alloy powder at 500 to 1000° C. in an atmosphere of an inert gas or a hydrogen gas, or under vacuum,
• said hydrogen storage alloy of starting material having body-centered cubic crystal structure or body-centered tetragonal crystal structure, and being represented by the general formula TiaM1bCrcM2dLe,
• wherein M1 is at least one element selected from the group consisting of Nb and Mo;
• M2 is at least one element selected from the group consisting of Mn, Fe, Co, Cu. V, Zn, Zr, Ag, Hf, Ta, W, Al, Si, C, N, P and B;
• L is at least one element selected from the group consisting of rare-earth elements and Y;
• 0.2≦a≦0.7;
• 0.01≦b≦0.4;
• 0.1≦c≦0.7;
• 0≦d≦0.3;
• 0≦e≦0.03;
• and a+b+c+d+e=1.0.

A method for manufacturing a hydrogen storage alloy electrode comprising the step of:

• conducting mechanochemical reaction between hydrogen storage alloy powder and nickel,
• said hydrogen storage alloy having body-centered cubic crystal structure or body-centered tetragonal crystal structure, and being represented by the general formula TiaM1bCrcM2dLe,
• wherein M1 is at least one element selected from the group consisting of Nb and Mo;
• M2 is at least one element selected from the group consisting of Mn, Fe, Co, Cu, V, Zn, Zr, Ag, Hf, Ta, W, Al, Si, C, N, P and B;
• L is at least one element selected from the group consisting of rare-earth elements and Y;
• 0.2≦a≦0.7;
• 0.01≦b≦0.4;
• 0.1≦c≦0.7;
• 0≦d≦0.3;
• 0≦e≦0.03;
• and a+b+c+d+e=1.0.