Destabilization of LiBH4 by SrF2 for reversible hydrogen storage

The de-/rehydrogenation features of the 6LiBH(4)/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 6LiBH(4)/SrF2 system proceeds via the 6LiBH(4) + SrF2 -> SrB6 + 2LiF + 4LiH + 10H(2) reaction, which involves SrH2 as the intermediate product. The dehydrogenation enthalpy change was experimentally determined to be 52 kJ/mol H-2 based on the P-C isotherm analysis. For rehydrogenation, LiBH4 and SrF2 were regenerated along with LiSrH3 at 450 degrees C under -8 MPa hydrogen pressure; thus, approximately 5.2 wt% of hydrogen can be released during the second dehydrogenation process. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.