A Mathematical Model for Calculation of the Formation Enthalpy of

Mg-based A2B Hydrides

Shoushi Fang, Jinlong Zhang, Ziqiang Zhou 

Institute of Hydrogen Storage Materials, Shanghai University, Shanghai, 200072, China

 Abstract

The mathematical model for calculation of the formation enthalpy of hydrides was successfully applied to the Mg-based A2B hydrogen storage alloys. The formation enthalpy of Mg-based A2B hydrides was mainly affected by the atomic size parameter and electron concentration. And the contribution of the electronegativity difference was much smaller than that of the other two factors. The contributions of the three factors to the formation enthalpies of Mg-based A2B hydrides were discussed together with other hydrides such as AB, AB2, and AB5 type ones. It is found that the electronegativity difference, the atomic size parameter and electron concentration have different effects (positive or negative) on the formation enthalpy of different hydrides.