Prediction of a novel orthorhombic LiBH phase and hydrogen adsorption at ambient pressure

Abstract

For further understanding of the various configurations of intermediate compounds in LiBH4 dehydrogenation, we used a crystal structure search to propose a novel stable orthorhombic LiBH compound at ambient pressure. Imma-LiBH can be synthesized though α-LiB and H2 and shows metallicity. The adsorption behavior investigation of H2 on the LiBH (100) surface reveals two chemical adsorption and five physical adsorption sites. The most stable mode of H2 adsorption occurs on the vertical hollow site. The partial density of state and electronic localization function of the mode indicate that the adsorbed H atom combine with Li and B atoms on the surface to form stable H–B covalent bond and H–Li ionic bond, respectively. Thus, Imma-LiBH can be used as a good hydrogen adsorption material for the application of electrode materials of hydrogen fuel cells.