Abstract: LiAlH4 and LiNH2 was ball milled at molar ratio of 1:2, thus prepared composite was heated for dehydrogenation, the fully dehydrogenated samples were re-hydrogenated. The dehydrogenation/re-hydrogenation processes were studied by means of XRD, DSC and FTIR analysis. The experimental results showed that the dehydrogenation process of LiAlH4/2LiNH2 composite is a three-stage reaction, and Li3AlN2 was formed after releasing 8.65wt% of hydrogen。The derived Li3AlN2 can be re-hydrogenated under conditions of 10MPaH2 and 400℃, and LiNH2 、AlN and LiH were formed. The reversible hydrogen storage capacity reached 5.0wt%. The dehydrogenation/re-hydrogenation mechanism of LiAlH4/2LiNH2 composite was discussed.

Key words: Hydrogen storage materials, Hydrogen storage properties, Complex hydride, Chemical hydride, Metal-nitrogen-hydride