The morphology and electrochemical properties of La1-xMgxNi3.4Al0.1 (x = 0.1–0.4) hydrogen storage alloys

In view of the importance of Mg in R-Mg-Ni-type alloys (R generally represents rare earth elements), the effect of Mg on the morphology and electrochemical performance of the as-cast La1-xMgxNi3.4Al0.1 (x = 0.1, 0.2, 0.3 and 0.4) hydrogen storage alloys were studied in this work. The samples possess multiphase structures, including Gd2Co7-, Ce2Ni7-, Pr5Co19-and CaCu5-type, PuNi3-and MgCu4Sn-type phases. It is found that reasonably increasing Mg contents can promote the formation of Gd2Co7-and Ce2Ni7-type phase as well as Mg contents have important effects on phase morphology. Furthermore, fine-dispersed LaNi5 structure in (La, Mg)2Ni7 matrix is beneficial to facilitate the hydrogen diffusion and exert the electrochemical properties for the alloys.