Hydrogen Storage in a LiNH₂−MgH₂ (1:1) System

A novel LiNH 2 −MgH 2 hydrogen storage system with a molar ratio of 1:1, which can desorb 6.1 wt % hydrogen or 3 equiv of H atoms during first ball milling and subsequent heating, was investigated. During ball milling, the NH 2 group in LiNH 2 and H atoms in MgH 2 switched with each other, leading to the formation of Mg(NH 2 ) 2 and LiH, and then the newly formed Mg(NH 2 ) 2 and LiH and the remaining MgH 2 reacted continuously to desorb hydrogen by absorbing heat at an elevated temperature. After heating to 390 °C, the final product was identified to be Mg 3 N 2, Li 2 MgN 2 H 2, and LiH by means of XRD and IR characterization. Thermodynamic examination shows that the desorption heat effect is around 45.9 kJ/mol of H 2 .