The effects of Ti alloying on Mg

2

Ni hydrogen storage alloy and corresponding hydrides were investigaged.The results indicate that Ti preferentially occupy the Mg（6i）site as the doping concentration in the range from 0to 0.5.The solid solution alloys Mg

2x

Ti

x

Ni with the hexagonal structure is easily decomposed into the complex phase with bcc structure Mg

3

TiNi

2

and hexagonal structure Mg

2

Ni.The Ti-doping can weaken the interaction between H and Ni atoms and reduce the enthalpy of hydrogen absorbing of the alloy system.Therefore

the ability of the solution of hydrogen for Mg

2

Ni hydride can be improved.