Hydrogen storage in a LiNH2-MgH2 (1:1) system

A novel LiNH2 - MgH2 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 NH2 group in LiNH2 and H atoms in MgH2 switched with each other, leading to the formation of Mg(NH2)(2) and LiH, and then the newly formed Mg(NH2)(2) and LiH and the remaining MgH2 reacted continuously to desorb hydrogen by absorbing heat at an elevated temperature. After heating to 390 degrees C, the final product was identified to be Mg3N2, Li2MgN2H2, 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.