Fast Mass Transport Kinetics in B20H16: A High-Capacity Hydrogen Storage Material

First-principles calculations are used to study the role of point defects in the rehydrogenation and dehydrogenation of B20H16; in particular, we focus on the energetics of long-range mass transport through bulk phases. We find that interstitial H-2 in B20H16 exists in the largest concentrations of all native point defects during both the formation and decomposition reactions. Using kinetic Monte Carlo simulations, we show that the diffusivity is high for this particular defect and that the overall activation energies for mass transport are 6 and 70 kJ/mol for the rehydrogenation and dehydrogenation reactions, respectively.