2D Layered Dichalcogenides As Active Cathode Materials for Magnesium-Ion Batteries

Abstract

Rechargeable battery chemistries that can circumvent some of the issues associated with modern lithium-ion technologies are in great demand for specialized application, where safety is more important than raw power density. Magnesium has been the focus of many alternative approaches, due to its high volumetric density, high abundance and its homogeneous electrochemical plating characteristics. In the past, a lack of suitable electrolytes with high oxidative stability and good conductivity as well as a paucity of viable cathode materials limited research to only a few standard materials, such as the Chevrel-phase Mo6S8. While providing a good benchmark system for comparison of different battery chemistries, such materials will not lead to a commercial success of the magnesium-ion technology. On the basis of our recently developed halide free electrolytes, we are able to investigate a wide range of new cathode materials for high voltage Magnesium-ion batteries. In this presentation we are focusing on 2D-layered metal-dichalcogenides and their capability to reversibly store magnesium. We investigate their electrochemical performance using a coin-cell platform. Ex-situ XRD, SEM and XPS experiments are performed to monitor changes in crystal structure or surface morphology and identify side reactions as well as the mechanism of magnesium storage.