Effect of Al content on Hydrogen Storage Properties of Amorphous Mg1-xAlxNi (x=0, 0.1, 0.2, 0.3) Alloy

摘要

In this paper, the influence of adding Al on the discharge capacity and cycle stability of amorphous MgNi-based hydrogen storage alloys were investigated. Amorphous Mg_(1_x)Al_xNi (x=0, 0.1, 0.2, 0.3) alloy powder was prepared successfully by mechanical alloying (MA). X-ray diffraction (XRD) results show that after ball milling with 15h, MgNi alloy formed completely amorphous phase. But for Mg_(1_x)Al_xNi (x=0.1, 0.2, 0.3) alloy, it took 30h. It can be concluded that Al partial substituting Mg would decrease the amorphous phase forming ability of Mg-Ni Based Alloy. The discharge capacities and cycle stabilities of these alloys were tested. Compared with amorphous MgNi alloy, the discharge capacities of Mg_(1-x)Al_xNi (x=0.1, 0.2, 0.3) alloy were decreased slightly, but the cycle stabilities were significantly enhanced. Mg0.9A10.lNi alloy showed the largest discharge capacity and Mg_(0.8)Al_(0.2)Ni alloy showed the best cycle stability. Over all, ternary Mg_(0.8)Al_(0.1)Ni alloy showed the best synthesis properties.