Potential of binary lithium magnesium nitride for hydrogen storage applications

Metal hydrides and amides are potential candidate materials for hydrogen storage. Lithium- and magnesium-based material systems are among the most promising materials owing to their high hydrogen contents. In the present work, we investigated hydrogenation/dehydrogenation reactions of a binary nitride, LiMgN. LiMgN can be formed by a reaction of MgH2 with LiNH2 in 1:1 ratio. The reaction also releases approximately similar to 8.1 wt % H-2 (theoretical value is 8.2 wt %) between 160 and 220 degrees C. The reaction product LiMgN can be rehydrogenated by reacting with H-2 under 2000 psi of hydrogen pressure and 160 degrees C with a small amount of TiCl3 doping. TGA results showed that about 8.0 wt % of hydrogen was stored in TiCl3-doped LiMgN during the hydrogenation process. The reversible hydrogenation and dehydrogenation mechanisms involving LiMgN and H-2 are discussed.