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 (H^δ+) and LiBH₄ (H^δ−) 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 H^δ+- H^δ− reaction. This work indicates possibilities for the development of fast and easy high-capacity hydrogen generation systems based on complex hydrides.