Enhanced Hydrogen Storage Properties and Reversibility of LiBH₄ Confined in Two-Dimensional Ti₃C₂

Abstract

LiBH4 is of particular interest as one of the most promising materials for solid-state hydrogen storage. Herein, LiBH4 is confined into a novel two-dimensional layered Ti3C2 MXene through a facile impregnation method for the first time to improve its hydrogen storage performance. The initial desorption temperature of LiBH4 is significantly reduced, and the de-/rehydrogenation kinetics are remarkably enhanced. It is found that the initial desorption temperature of LiBH4@2Ti3C2 hybrid decreases to 172.6 °C and releases 9.6 wt % hydrogen at 380 °C within 1 h, whereas pristine LiBH4 only releases 3.2 wt % hydrogen under identical conditions. More importantly, the dehydrogenated products can partially rehydrogenate at 300 °C and under 95 bar H2. The nanoconfined effect caused by unique layered structure of Ti3C2 can hinder the particles growth and agglomeration of LiBH4. Meanwhile, Ti3C2 could possess superior effect to destabilize LiBH4. The synergetic effect of destabilization and nanoconfinement contributes to the remarkably lowered desorption temperature and improved de-/rehydrogenation kinetics.