Reversible hydrogen release and uptake for composites of LiBH4 with the conjugated polymer poly(p-phenylene)

In this study, hydrogen release and uptake properties for composites of LiBH4 with the conjugated polymer poly(p-phenylene) (PPP) were investigated. The incorporation of LiBH4 with PPP led to a significant destabilization effect, decreasing the dehydrogenation temperature of LiBH4 by 100 °C. Moreover, LiBH4 could be regenerated at 450 °C under 9.0 MPa H2. By thorough analyses using XRD, HRTEM, FTIR, Raman, XPS as well as 11B MAS NMR, the dehydrogenation product of LiBH4+PPP and the regeneration mechanism of LiBH4 are elucidated. Also the reason of capacity degradation is discussed based on the analysis results. The formation condition of LiBH4 was significantly moderated due to the presence of a simultaneously formed amorphous mixture of boron and carbon, which sheds light on the improvement of LiBH4 reversibility.