Effect of Pd Content on the Phase Formation and Hydrogen Storage Properties of Mg-Ni Based Hydrogen Storage Alloy

Hydrogen storage materials Mg-54.7Ni-xPd(x=0,3,10,mass ratio) mixture are synthesized by mechanical alloying. The effect of Pd content on the phase formation and hydrogen storage properties of Mg-Ni based hydrogen storage alloy is investigated by XRD and measuring apparatus for hydrogen storage properties. XRD analysis indicates that after ball milling for 30hours under 0.30MPa argon pressure,the powders didn~′t transform to alloys,but when reacting with hydrogen at 523K,Mg-54.7Ni-xPd(x=0,3) transforms to a lot of Mg_2NiH_4 while the hydrides of Mg-54.7Ni-10Pd are composed of MgH_2 and a small quantity of Mg_2NiH_4.The results of hydrogen storage properties measured show that the obtained materials can absorb hydrogen at 473K without activation. Comparing with Mg-54.7Ni-xPd(x=0,10),Mg-54.7Ni-3Pd has the fastest speed of hydriding and dehydriding and the most reversible storage capacity (2.82,mass ratio).