Dehydrogenation behavior of LiBH4/CaH2 composite with NbF5

Abstract

The dehydrogenation behavior of 6LiBH(4) + CaH2 + 0.2NbF(5) composite has been investigated. It is demonstrated that the addition of NbF5 is effective in lowering the dehydrogenation temperature of this composite. The composite starts dehydrogenation before the melting of LiBH4 and releases 9.1 wt.% hydrogen up to 400 degrees C. The equilibrium dehydrogenation temperature under I bar of hydrogen is estimated to be 309 degrees C with a reaction enthalpy change of 56.5kJ mol(-1) H-2, which is consistent with thermodynamic calculation. Crown Copyright (c) 2008 Published by Elsevier Ltd. on behalf of Acta Materialia Inc. All rights reserved.