A precise prediction of structure stability and hydrogen storage capability of KCdH3 perovskite hydride using density functional theory calculations

Perovskite hydrides materials are acknowledged for hydrogen storage due to their high capacity, reversibility, thermodynamic stability, tunable nature, and potential low-cost solutions. In the current investigation, the four distinct cubic structures of perovskite hydride KCdH3 for the hydrogen storage are investigated with the help of density functional theory and providing valuable insights into stable phases. Electronic, thermal and entropy calculations are performed. Two out of four cubic structure are founded mechanically stable with the gravimetric storage capacity of be 5.5 cwt% and the volumetric storage capacity of 67.69 gH2l−1 which align with the standard situated by the U.S. Department of Energy for the year 2025. Notably, this study is the first comprehensive investigation of all four cubic phases of the KCdH3 compound. The promising hydrogen storage capabilities of these compounds shows the credibility for their effective use as a solid-state hydrogen storage material, and the research aims to further ascertain its stability and storage capacities. •In the current study, the four distinct cubic structures of perovskite hydride KCdH3 for the hydrogen storage are investigated with the help of density functional theory.•The thermal stability of KCdH3 perovskite hydrides is assessed by determining their enthalpy of formation.•Gravimetric (Cwt%) and volumetric (Cv) storage capacities of KCdH3 and c-KCdH3 hydrides are analyzed, with values meeting DOE 2025 targets.•The promising hydrogen storage capabilities of perovskite hydrides shows the credibility for their effective use as a solid-state hydrogen storage material