Effect of SrAl2H2 on the Stability of MgH2 for Hydrogen Storage Application

High-density hydrogen storage is a significant challenge for stationary, mobile and transportation applications, so the storage in solid materials remains the safest way. By performing the first-principles calculations within the generalized gradient approximation (GGA) and using the pseudo-potentials and plane waves based on the density-functional theory (DFT), the effect of zintl phase hydride SrAl2H2 on the stability of the magnesium dihydride compound (MgH2) is studied for an application in the field of hydrogen storage in solid materials. Their crystal structures are known and occurs in a trigonal and tetragonal respectively. Therefore; we investigated the enthalpy of formation for three reactions between MgH2 and SrAl2H2 compounds by calculating the total energies of MgSr and SrAl2 compounds. These last compounds crystalize in cubic and orthorhombic structure respectively. We also investigated the structural and the electronic properties of these compounds and discuss the chemical bond nature using total and partial density of electronic states. Our calculated results are generally in good agreement with theoretical and experimental data.