Ultrafast reaction between Li3N and LiNH2 to prepare the effective hydrogen storage material Li2NH

Li2NH is a promising candidate for hydrogen storage. However, its performance for hydrogen absorption is strongly dependent on its preparation method. In this paper, we report that an ultrafast solid reaction between Li3N and LiNH2 provides a new synthesis approach to an effective Li2NH material, which can reversibly store 6.8 wt % hydrogen with fast kinetics and excellent stability. In contrast, Li2NH prepared via the conventional LiNH2 decomposition method absorbs less than 2 wt % hydrogen in 500 min. Scanning electron microscopy (SEM) and BET measurements demonstrated that the poor performance of Li2NH prepared via the conventional decomposition method is caused by sintering. In addition, the hydrogen capacity of Li2NH, which was prepared via the reaction between LiH and LiNH2, reached a value of only about 4 wt % after 500 min.