Monolayer Transition-Metal Dichalcogenide Mo1–xWxS2Alloys as Efficient Anode Materials for Lithium-Ion Batteries

Abstract

Intercalation of metal ions in the van der Waals gap of layered materials forms the basis for large-scale electrochemical energy storage. In this work, by means of periodic density functional theory calculations, transition-metal dichalcogenide Mo1–xWxS2 alloys have been explored as efficient materials for lithium storage. Our study reveals that lithium prefers to bind efficiently to the monolayer alloy and diffuses easily with short diffusion distances. All bare phases of alloys are semiconducting, and a semiconducting to metallic phase transition occurs after lithiation, which ensures good electrical conductivity and is crucial for electrode material. We find negligible average open-circuit voltage at different chemical stoichiometries of 0.67, 1.33, and 2. Effects of both strain and concentration on adsorption energy and diffusion barriers are calculated. The effect of strain has manifested significant rise in adsorption energy, whereas in the case of diffusion barrier, this effect is almost negligible...