Preparation and hydrogen storage properties of Mg-Al-Li solid solution

•Quenching can enhance hydrogen desorption kinetics of the Mg-Al-Li composite.•Milling can improve hydrogen storage properties of the Mg-Al-Li composite.•The hydrogen storage capacity of Mg17Al12 (Li) solid solution reaches 3.7 wt.%.•The Mg17Al12 (Li) solid solution has good thermodynamic property.

In this work, a Mg-Al-Li solid solution was prepared and the influence of the preparation process on its hydrogen storage properties was investigated. The Mg17Al12 (Li) solid solution was obtained by sintering, annealing at liquid nitrogen temperature and mechanical ball milling using a molar ratio of Mg:Al:LiH = 6.5:1.5:2.0. The maximum hydrogen storage capacity of the Mg17Al12 (Li) solid solution reached 3.7 wt.% at 300 °C in 80 min. The enthalpy of the solid solution hydride decomposition was 53 kJ mol−1 H2, much lower than that of bulk Mg hydride decomposition (75 kJ mol−1 H2). The solid solution had higher hydrogen storage capacity and better hydrogen absorption kinetics than Mg17Al12 alloy.