The Li-N-H system expressed by LiNH2+LiH↔Li2NH+H2 can be expected as a promising candidate for the hydrogen storage materials because of possessing a large amount of reversible hydrogen (6.5 wt.%), a satisfactorily fast kinetics and a relatively small enthalpy change. In this work, we investigated the hydrogen storage properties of the Li-N-H system from three different points of view. Firstly, we claim that the ball milled 1:1 mixture of lithium amide (LiNH2) and lithium hydride (LiH) containing a small amount (1 mol %) of titanium chloride (TiCl3) shows superior hydrogen storage properties; a large amount of H2 gas desorbs in the temperature range from 150 to 250 ° C at a heating rate of 5 ° C/min and it reveals an excellent reversibility. Secondly, we clarify that the above hydrogen desorption reaction is composed of two kinds of elementary reactions: The one is that 2LiNH2 decomposes to Li2NH and emits ammonia (NH 3). The other is that the emitted NH3 reacts with LiH and transforms into LiNH2 and H2, indicating that NH 3 plays an important role on this H2 desorption reaction. Finally, we examined the reaction of LiH and LiOH to clarify the influence of exposing the product to air. This is because due to the fact that LiOH is easily produced by exposing LiH and LiNH2 to air. The reaction between LiH and LiOH indicated better kinetics but worse durability and an extra H 2 desorption due to transforming into Li2O.
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