LAUSR

Abstract Using Ab-initio calculations, we investigate the destabilizing effects of co-doped MgH 2 with Li and TM (Sc, Ti, V, Cr, Y, Zr, Nb, Mo). The calculations are performed using the all-electron full-potential local-orbital minimum-basis scheme (FPLO9.00-34). Our findings indicate that the doping of Li beside TM played an important role in improving the thermodynamic properties of MgH 2 . Through this double substitution, a reduction of heat of formation/desorption and preservation of the optimum gravimetric capacity are obtained. Precisely, we find that the co-doping with V Li; Zr Li; Ti Li; Y Li, have desorption temperatures within the optimum range 289 K–393 K, for the practical applications. More precisely, the V Li co-doping exposes a heat of formation −39.21kj/mol which is the closest to the ideal heat of formation −40kj/mol. Besides, our results suggested that, the combination of Li with V into MgH 2 is greatly favourable compared to V doping alone. To understand the processes for absorption/desorption of MgH 2 , detailed discussion of the electronegativity, the charge exchange and the density of states is carried out.