Effects of doping FeCl3 on hydrogen storage properties of Li-N-H system

Abstract The effects of doping FeCl 3 on the LiNH 2 −2LiH system were investigated systematically. FeCl 3 was prior to react with LiH during ball milling their mixtures. The metallic Fe, which is generated from metathesis reaction between FeCl 3 and LiH, plays an important role on improving the dehydrogenation kinetics of LiNH 2 −2LiH system. The results indicated that the dehydrogenation peak and ending temperatures of the doped 1 mol% FeCl 3 sample shifted to low temperatures, and the dehydrogenation active energy changed from 102.45 kJ/mol to 87.52 kJ/mol. While increasing the amount of FeCl 3 , an excess of LiCl, the by-product of metathesis reaction between FeCl 3 and LiH, can stabilize LiNH 2 and thus hinder hydrogen desorption. The dehydrogenation product is a new solid cubic phase solution of lithium imide-chloride. The high limit of the solid solution of LiCl and Li 2 NH is near the molar ratio of 1:1.