Low-temperature hydrogen release exceeding 7 wt% from LiBH4-mannitol composites

Abstract

Among conventional hydrogen storage materials, LiBH4 has been regarded as one of the best hydrogen transporters due to its relatively large hydrogen capacities. However, because of its extraordinarily high dehydrogenation temperatures, LiBH4 was not suitable for hydrogen storage due to its stable thermodynamic features. Herein, we present a novel approach to LiBH4 that uses solid-state multi-hydroxyl mannitol as a reactant, regulating hydrogen release below 69.9 °C. More than 7 wt% H2 could be released with ultra-fast rates at 140 °C from the LiBH4-mannitol composite. XRD, FTIR, and SEM tests revealed that the reaction between mannitol (Hδ+) and LiBH4 (Hδ−) to produce hydrogen was accompanied by the generation of large amounts of heat in situ, which further promoted the decomposition of LiBH4 for hydrogen production, exceeding the theoretical dehydrogenation amount of Hδ+- Hδ− reaction. This work indicates possibilities for the development of fast and easy high-capacity hydrogen generation systems based on complex hydrides.