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.