Improvement in Hydriding and Dehydriding Features of Mg–TaF(5)–VCl(3) Alloy by Adding Ni and x wt% MgH(2) (x = 1, 5, and 10) Together with TaF(5) and VCl(3)

In our previous work, TaF(5) and VCl(3) were added to Mg, leading to the preparation of samples with good hydriding and dehydriding properties. In this work, Ni was added together with TaF(5) and VCl(3) to increase the reaction rates with hydrogen and the hydrogen-storage capacity of Mg. The addition of Ni together with TaF(5) and VCl(3) improved the hydriding and dehydriding properties of the TaF(5) and VCl(3)-added Mg. MgH(2) was also added with Ni, TaF(5), and VCl(3) and Mg-x wt% MgH(2)-1.25 wt% Ni-1.25 wt% TaF(5)-1.25 wt% VCl(3) (x = 0, 1, 5, and 10) were prepared by reactive mechanical milling. The addition of MgH(2) decreased the particle size, lowered the temperature at which hydrogen begins to release rapidly, and increased the hydriding and dehydriding rates for the first 5 min. Adding 1 and 5 wt% MgH(2) increased the quantity of hydrogen absorbed for 60 min, H(a) (60 min), and the quantity of hydrogen released for 60 min, H(d) (60 min). The addition of MgH(2) improved the hydriding–dehydriding cycling performance. Among the samples, the sample with x = 5 had the highest hydriding and dehydriding rates for the first 5 min and the best cycling performance, with an effective hydrogen-storage capacity of 6.65 wt%.