Abstract: The Mg based hydrogen storage alloys Mg_{1- x} Ti_x Ni(0≤ x ≤0.4) were successfully synthesized by mechanical alloying(MA). The X ray diffraction showed that the amorphous structures of the alloys were different from the diverse components and would be completed with increasing the ball milling time. It was found that the discharge capacity and the cycle life of the alloys were improved with Ti partial substitution. Among the alloys which were prepared by ball milling for 120 h, the discharge capacity of the Mg_0.9 Ti_0.1 Ni alloy electrode was 356.85 mA·h ·g^-1 (100 mA·g^-1, -0.5 V vs. Hg/HgO) in the first charge discharge cycle, and Mg 0.7 Ti 0.3 Ni showed the best cycle life. It was also found that the Ti partial substitution was more effective to improve the anti corrosion behavior.

Key words: Mg based hydrogen storage alloys, Mechanical alloying, Amorphous state, Electrode