Mg–M–LiH alloys prepared by mechanical milling and their hydrogen storage characteristics

• Diluted Mg96M2(LiH)2 (M = Y, Zn, Al, Ag) alloys were prepared by ball milling.
• The milled materials were exposed to air for 12 h.
• The milled and oxidized materials were able to store between 5.0 and 6.2 wt.% H2.
• Mg-LiH materials presented acceptable hydriding/de-hydriding kinetics.

Mg96M2(LiH)2 (M = Y, Zn, Al, Ag), Mg98(LiH)2 and Mg96(LiH)4 powder alloys were produced by ball milling and deliberately air-exposed by 12 h in order to investigate their hydrogen storage properties. The addition of LiH at the level of 2 mol% had a beneficial effect on the kinetics of the hydriding and dehydriding processes at 300 and 350 °C compared to mechanically milled and air-exposed Mg powders. However, the additions of Al, Ag, Zn and Y had an opposite effect on the hydriding/dehydriding kinetics. The addition of Al provided a small advantage in the capacity of hydrogen storage among the tested materials. The effects of air-exposure were analyzed, it was demonstrated that among a set of Mg and Mg-alloys heavily oxidized the hydrogen storage is still viable.