Single-pot solvothermal strategy toward support-free nanostructured LiBH4 featuring 12 wt% reversible hydrogen storage at 400 °C

Lithium borohydride (LiBH 4 ) exhibits poor hydrogen storage reversibility because of phase separation between LiH and B due to foaming during thermal dehydrogenation. Herein, we report that by synthesizing nanostructured LiBH 4 without any supports, the foaming and phase separation can be effectively suppressed, and consequently, the hydrogen storage reversibility of LiBH 4 can be considerably improved. Using a facile single-pot solvothermal approach, a hierarchical porous nanostructured LiBH 4 composed of 50–60 nm-sized primary nanoparticles is synthesized. The resulting neat nano-LiBH 4 reversibly desorbs and absorbs approximately 12 wt% of H at 400 °C and under 100 bar H 2 . The superior hydrogen storage performance is attributed to the effective inhibition of foaming upon heating. The formation of LiH and B prior to melting, which can be associated with the largely reduced particle sizes and porous agglomeration structure, plays a crucial role in suppressing foaming. Our findings offer a new strategy for the preparation of nanoscaled freestanding borohydrides, and also important insights into the development of highly reversible metal borohydrides for hydrogen storage applications.