Ab-initio calculations for the study of the hydrogen storage properties of CsXH3 (X= Co, Zn) perovskite-type hydrides

This work presents a Density Functional Theory (DFT) study of the single perovskite CsXH3 (X = Co, Zn). We used the CASTEP code to perform first-principles calculations and investigate the hydrogen storage properties of CsXH3 (X = Co, Zn). We calculated the structural, Hydrogen, mechanical, electronic, optical, and thermal properties of CsXH3 (X = Co, Zn) perovskite materials for hydrogen storage applications. Electronic properties reveal that CsXH3 (X = Co, Zn) has a metallic behavior. The calculated value of formation energy is −0.47 eV/atom and −0.18 eV/atom for CsCoH3 and CsZnH3, respectively, which means that the studied materials are synthesizable and thermodynamically stable. Our results show that CsXH3 (X = Co, Zn) is a promising material for hydrogen storage, as it exhibits high hydrogen storage capacity. The gravimetric ratio values are 2.82 wt% and 3.09 wt% for CsCoH3 and CsZnH3, respectively. The determined elastic constants show that CsXH3 (X = Co, Zn) is mechanically stable. Our study provides valuable insights into using single perovskite CsXH3 (X = Co, Zn) as a potential material for hydrogen storage applications.