Hydrogenation and electrochemical studies of La-Mg-Ni alloys

La-Mg-Ni alloys are potential candidates for hydrogen storage materials. In this study, mechanical alloying with subsequent annealing under an argon atmosphere at 973 K for 0.5 h, were used to produce La2-xMgxNi7 alloys (x = 0, 0.25, 0.5, 0.75, 1). Shaker type ball mill was used. An objective of the present study was to investigate an influence of amount of Mg in alloy on electrochemical, hydrogenation and dehydrogenation properties of La-Mg-Ni materials. X-ray diffraction analyses revealed formation of material with multi-phase structure. Obtained materials were studied by a conventional Sievert's type device at 303 K. It was observed that electrochemical discharge capacity and gaseous hydrogen storage capacity of La-Mg-Ni alloys increases with Mg content to reach maximum for La1.5Mg0.5Ni7 alloy. Moreover, all of La-Mg-Ni alloys were characterized by improved hydrogen sorption kinetics in comparison to La-Ni alloy.