In Situ Synthesis of 3D Flower-Like Nanocrystalline Ni/C and its Effect on Hydrogen Storage Properties of LiAlH.

Lithium alanate (LiAlH ) is of particular interest as one of the most promising candidates for solid-state hydrogen storage. Unfortunately, high dehydrogenation temperatures and relatively slow kinetics limit its practical applications. Herein, 3D flower-like nanocrystalline Ni/C, composed of highly dispersed Ni nanoparticles and interlaced carbon flakes, was synthesized in situ. The as-synthesized nanocrystalline Ni/C significantly decreased the dehydrogenation temperature and dramatically improved the dehydrogenation kinetics of LiAlH . It was found that the LiAlH sample with 10 wt % Ni/C (LiAlH -10 wt %Ni/C) began hydrogen desorption at approximately 48 °C, which is very close to ambient temperature. Approximately 6.3 wt % H was released from LiAlH -10 wt %Ni/C within 60 min at 140 °C, whereas pristine LiAlH only released 0.52 wt % H under identical conditions. More importantly, the dehydrogenated products can partially rehydrogenate at 300 °C under 4 MPa H . The synergetic effect of the flower-like carbon substrate and Ni active species contributes to the significantly reduced dehydrogenation temperatures and improved kinetics.