Study on reversible hydrogen sorption behaviors of 3LiBH4/graphene and 3LiBH4/graphene–10 wt% CeF3 composites

Abstract

In the present work, two LiBH₄ based hydrogen storage composites, namely, 3LiBH₄/graphene and 3LiBH₄/graphene–10 wt% CeF₃, were prepared through ball milling and their hydrogen sorption behaviors were investigated. It was shown that the dehydrogenation kinetics of 3LiBH₄/graphene was improved by doping 10 wt% CeF₃, which was attributed to the formation of CeB₆. The rehydrogenation of the 3LiBH₄/graphene composite could be achieved under 440 °C with 3.3 MPa hydrogen pressure and the hydrogen absorption capacity reached 7.40 wt% to LiBH₄ after 10 h. Further addition of CeF₃ did not improve the rehydrogenation kinetics but reduced the absorption capacity. SEM observations suggested that LiBH₄ was confined in a graphene wrapper after rehydrogenation, forming “graphene capsules” that helped the regeneration of LiBH₄.