Catalyzed LiBH4 Hydrogen Storage System with In Situ Introduced Li3BO3 and V for Enhanced Dehydrogenation and Hydrogenation Kinetics as Well as High Cycling Stability

LiBH4 as a promising candidate material for solid-state hydrogen storage still suffers from high dehydrogenation temperature and poor reversibility. A catalyzed LiBH4-based system with in situ introduced Li3BO3 and V is synthesized by adding NH4VO3 into LiBH4 followed by a heat treatment and a hydrogenation process. The optimized LiBH4 system introduced with 0.06 molar fraction of Li3BO3 + V, which is denoted as LiBH4-0.06LiBOV, shows excellent hydrogen storage kinetics and high reversible stability. The system starts to release hydrogen at 220 degrees C, and a capacity of 5.8 wt % H-2 is obtained at 350 degrees C within 90 min. Furthermore, full rehydrogenation can be achieved at 500 degrees C and 50 bar of H-2 for 50 min, and a capacity retention as high as 87.5% is obtained after five cycles. In situ introduced Li3BO3 and V lower the activation energy of LiBH4 and inhibit the generation of Li2B12H12 during the hydrogenation of LiBH4, which contribute to the synergistic catalytic effects on hydrogen desorption and absorption. In addition, the restraining of the particle size growth during dehydrogenation/hydrogenation is critical to inhibiting the generation of Li2B12H12 and thus improves the hydrogenation property of LiBH4. The catalyzed LiBH4 system provides new insights on LiBH4 as a high-density hydrogen storage material.