Electronic and elastic properties cubic of LiBH4 and Li(BH)3 as host materials for hydrogen storage

Due to growing interest to explore and predict potential hydrogen storage materials by adopting theoretical and greatly functional software, research on lightweight materials has taken great attention. From this perspective, this study focuses on investigating electronic, elastic, and anisotropic properties of cubic LiBH4 and Li(BH)(3) using first principles calculations for the first time. A comprehensive investigation has been carried out to reveal materials' electronic, elastic, hardness, and anisotropic behaviour. The calculations exhibit that both LiBH4 and Li(BH)(3) has negative formation energies as - 0.268 eV/atom and - 0.187 eV/atom, respectively which indicate synthesisability and thermodynamic stability. Elastic constants of materials are used to predict mechanical stabilities based on the well-known Born stability criteria. It is seen that both materials are mechanically stable. The electronic band structures indicate band gaps between valence and conduction band as 6 eV for LiBH4 and 4.58 eV for Li(BH)(3), showing non-metallic nature of both materials. The negative Cauchy pressures and the B/G ratio less than 1.75 indicate brittleness of both materials. The anisotropy factors of both materials display that these materials are anisotropic due to a deviation from unity. The hydrogen desorption temperature is also estimated as similar to 198.2 K for LiBH4 and similar to 138.6 K for Li(BH)(3).