Study of the Gravimetric, Electronic and Thermoelectric Properties of XAlH3 (X = Be, Na, K) as hydrogen storage perovskite using DFT and the BoltzTrap Software Package

Abstract

In the context of density functional theory (DFT), this study examines the structural, electronic, gravimetric and thermoelectric properties of perovskite compounds XAlH3 (X = Be, Na and K) using the generalized gradient approximation (GGA). Calculations were performed with the BoltzTrap software package integrated into the Wien2k code, enabling analysis of total energy and atomic volume using the Murnaghan equation of state. The results show that the materials behave like conductors due to the overlap of the conduction band and the valence band, with a zero band gap. NaAlH3 and KAlH3 show increasing electrical and thermal conductivity with temperature, while BeAlH3 exhibits non-linear behavior, peaking at 400 K. These results suggest that XAlH3 materials are promising for hydrogen storage applications and thermoelectric devices, underlining their potential to support a sustainable hydrogen economy.