Structure and hydrogen storage property of ball-milled LiNH2/MgH2LiNH2/MgH2 mixture

A hydrogen storage material was prepared by mechanical milling of LiNH2/MgH2LiNH2/MgH2 (2:1) mixture. Phase identification and structural investigation indicated that the initial dehydrogenation leads to the formation of a novel Li–Mg–N–H phase. The reversible reaction between the novel phase and Mg(NH2)2/LiHMg(NH2)2/LiH mixture in the following de-/rehydrogenation cycles at 200∘C leads to a stable hydrogen uptake capacity of ∼4.3wt%. The dehydrogenation of the material can be performed at lower temperatures, but with markedly slow kinetics and lowered hydrogen uptake capacity.