Over 6 wt% hydrogen release below 60 ℃ from LiAlH4 triggered by fluorinated acetylene black

Abstract

Lithium aluminum hydride (LiAlH₄) has been acknowledged as a vital solid-state hydrogen storage material with its large dehydrogenation capacity of 10.6 wt%. However, pure LiAlH₄ was hard to release hydrogen under 120 ℃, which strongly hindered its practical application. In this study, solid-state fluorinated acetylene black (FAB) was used as an additive to destabilize LiAlH₄. According to the experimental results, FAB-doped LiAlH₄ could achieve an ultrafast one-step hydrogen release over 6 wt% hydrogen release, which could be fully accomplished below 60 ℃, showing a great potential to be used as an easy hydrogen source. Through the microstructural study, it was found that FAB nano-sized particles adhered to the surface of LiAlH₄. Then this structure increased the activation sites, and triggered the fast heat emission and hydrogen release of LiAlH₄ during the dehydrogenation process. Moreover, the dehydrogenation reaction path was changed by the doping of FAB, which greatly lowering the dehydrogenation enthalpy change of LiAlH₄. This study provides some inspiration for the utilization of LiAlH₄ as an easy one-time hydrogen source under moderate environment.