La(1-x)MgxNi4.25Al0.75(x=0-0.3)合金的结构与储氢性能研究

采用三步感应熔炼法制备了La(1-x)MgxNi4.25Al0.75 (x=0.0，0.1，0.2，0.3) 储氢合金，对该系列合金的晶体结构和储氢性能方面进行了研究。晶体结构和相分析结果表明，当x=0.0和0.1时，合金由单一的LaNi4Al相组成；而x=0.2和0.3时，合金由LaNi4Al相, (La,Mg)Ni3相和AlNi3相构成。随着Mg含量x从0.2增至0.3时，合金的第二相丰度和吸/放氢平衡压明显升高，同时储氢容量减小。研究发现，当Mg添加量x=0.1时，合金除具有良好的储氢容量和低平台压外，其吸氢动力学性能更好。

The Structure and hydrogen storage properties of La(1-x)MgxNi4.25Al0.75(x=0.0-0.3) Alloys

La(1-x)MgxNi4.25Al0.75 (x=0.0, 0.1, 0.2, 0.3) hydrogen storage alloys were synthesized by means of a three-step induction melting. Their crystal structures and hydrogen storage properties were investigated in the present work. Studies inform that alloys with x=0.0 and 0.1 Mg contain a single LaNi4Al phase, however, those alloys with x=0.2 and 0.3 are composed of LaNi4Al, (La,Mg)Ni3 and AlNi3 phases. With x increasing from 0.2 to 0.3, the abundances of the secondary phases and the plateau pressures in the pressure-composition isotherms are lifted significantly. Meanwhile, their hydrogen storage capacities are remarkably reduced. The alloy with x=0.1 possesses the fastest absorption kinetics compared to the other alloys as well as a good hydrogen capacity and a low plateau pressure.