Destabilization and regeneration of LiBH4 using N-containing hydrocarbon based polymers for hydrogen storage

Abstract

Two N-containing hydrocarbon based polymers polyacrylonitrile (PAN) and polyaniline (PANI) were found to be able to destabilize LiBH4, a potential hydrogen storage material, resulting in larger hydrogen capacities of more than 10 wt% with peak dehydrogenation temperatures around 344 °C. The results suggest that a co-destabilization effect was achieved through the interaction of BH and CH bonds, which was further enhanced due to the presence of nitrogen atoms in polymers. After rehydrogenation of the dehydrogenated products, LiBH4 was found to be regenerated to a large extent in both of the LiBH4+polymer composites. Detailed analysis including XRD, FTIR, DSC-TG-MS, HRTEM, Raman, XPS and solid-state 11B MAS NMR was performed to elucidate the dehydrogenation and rehydrogenation mechanisms in these composites. The results provide considerable information about interaction mechanisms among BH, CH, NH and CN bonds and also shed lights on the enhancement of LiBH4 dehydrogenation and reversibility.