Voltage profile, structural prediction, and electronic calculations for MgxMo6S8

Abstract

A systematic computational investigation of the new Chevrel phase, MgxMo6S8 for 0<=x<=2, a candidate for a high-energy density cathode in prototype rechargeable magnesium (Mg) battery systems is performed. A study within the framework of both the local-density-functional theory and the generalized gradient approximation technique is conducted. Analysis of the calculated energetics for different magnesium positions and composition suggest a triclinic structure of MgxMo6S8 (x = 1 and 2). The results compare favourably with experimental data and suggest a charge transfer from Mg to the Mo6S8 cluster, having a significant effect on the Mo-Mo bond length.