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

Abstract

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 Na 2 CaCdH 6 hydride alloys were examined in this work using DFT. According to the structural properties, Na 2 CaCdH 6 has space group 225 (Fm3m), and optimized lattice parameters and volume of Na 2 CaCdH 6 are 3.3485 Å and 593.764 Å 3 . The measured gravimetric H storage capacity of Na 2 CaCdH 6 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 Na 2 CaCdH 6 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 Na 2 CaCdH 6 hydride can conduct electricity and is also mechanically stable. Our findings shed light on the possibilities of Na 2 CaCdH 6 perovskite hydride material for H storage utilization.