Destabilization of LiBH4 by SrF2 for reversible hydrogen storage

The de-/rehydrogenation features of the 6LiBH4/SrF2 reactive hydride system have been systematically investigated. It was found that the thermal stability of LiBH4 can be reduced markedly by combining it with SrF2. Dehydrogenation of the 6LiBH4/SrF2 system proceeds via the 6LiBH4 + SrF2 → SrB6 + 2LiF + 4LiH + 10H2 reaction, which involves SrH2 as the intermediate product. The dehydrogenation enthalpy change was experimentally determined to be 52 kJ/mol H2 based on the P-C isotherm analysis. For rehydrogenation, LiBH4 and SrF2 were regenerated along with LiSrH3 at 450 °C under ∼8 MPa hydrogen pressure; thus, approximately 5.2 wt% of hydrogen can be released during the second dehydrogenation process.