Reaction Route Optimized LiBH4 for High Reversible Capacity Hydrogen Storage by Tunable Surface-Modified AlN

LiBH 4 (lithium borohydride) is a promising high capacity hydrogen storage material but suffering from its high dehydrogenation temperature and poor reversibility. To solve this problem, surface-modified AlN (aluminum nitride) was prepared by the alcoholysis process of LiBH 4 and composited with LiBH 4 . By controlling the temperature of the drying process, it can tune the sorts and quantities of the functional groups on AlN. The de/rehydrogenation of LiBH 4 is greatly improved by compositing it with surface-modified AlN because oxygen atoms in functional groups promote the decomposition of intermediates of LiBH 4 and H δ+ (positive hydrogen atom) reacting with H δ− (negative hydrogen atom) in LiBH 4 . Besides, AlN provides the pathway of H and Li atoms to improve the kinetics of the de/rehydrogenation of LiBH 4 . Freeze-dried AlN containing O–H and C–H groups shows the best catalytic effect on the hydrogen storage reaction of LiBH 4 . The optimized composite could release a stable capacity of more than 6.1 wt % after cycling, which has potential applications in high-temperature environment hydrogen storage.