Computational insights of double perovskite Na₂CaCdH₆ hydride alloy for hydrogen storage applications: a DFT...

Prospective use of perovskite hydride materials in H storage a crucial element of clean energy systems has drawn a lot of attention. The structural, electrical, mechanical, thermodynamic, and H storage qualities of Na₂CaCdH₆ hydride alloys were examined in this work using DFT. According to the structural properties, Na₂CaCdH₆ has space group 225 (Fm3m), and optimized lattice parameters and volume of Na₂CaCdH₆ are 3.3485 Å and 593.764 ų. The measured gravimetric H storage capacity of Na₂CaCdH₆ hydrides is 2.956 wt%. The hydrides under research are semiconductors, as indicated by the computed electronic characteristics. Elastic constants, Pugh's ratio, modulus, Poisson's ratio, anisotropic, and microhardness of Na₂CaCdH₆ are calculated under mechanical properties. The hydrides are dynamically stable, as indicated by the phonon dispersion curves, but mechanically stable according to the Born criterion for elastic constant (C_ij). The Cauchy's pressure (C″ = 7.836) revealed the ductile behavior. The electronic and mechanical characteristics imply that Na₂CaCdH₆ hydride can conduct electricity and is also mechanically stable. Our findings shed light on the possibilities of Na₂CaCdH₆ perovskite hydride material for H storage utilization.