A Computational Investigation of Lithium‐Based Metal Hydrides for Advanced Solid‐State Hydrogen Storage

Abstract Hydrogen storage is a crucial step in commercializing hydrogen‐based energy production. Solid‐state hydrogen storage has gained much attention from researchers and needs extensive research. In the present study, we investigate the structural, mechanical, and optoelectronic properties of lithium‐based LiAH 3 (A=Mn, Fe, Co) metal hydrides to elucidate their potential for solid‐state hydrogen storage. First, we evaluate the structure stability of LiAH 3 hydrides using formation enthalpies calculations. Then, the mechanical stability is determined by elastic stiffness constants, which reveal that LiAH 3 hydrides are stable mechanically as they meet the Born stability requirements. Electronic band structure calculations manifest that all LiAH 3 hydrides possess a metallic character. Several optical properties have been discussed in detail. The gravimetric hydrogen storage capacities of LiMnH 3 , LiFeH 3 and LiCoH 3 hydrides are 4.65, 4.60 and 4.39 wt%, respectively, achieving the target of US‐DOE for rechargeable equipment. Additionally, we have determined the volumetric hydrogen storage capacities (C v ) for all LiAH 3 hydrides. It is worth mentioning that the highest C v values have been obtained to be 180.80, 188.18 and 177.25 gH 2 l −1 for LiMnH 3 , LiFeH 3 and LiCoH 3 hydrides, respectively, which have achieved the US‐DOE target set for 2025. Our investigation predicts the applicability of lithium‐based hydrides as promising solid‐state hydrogen storage materials.