A Single Mg Ion-conductive Polymer-coated MgCo2O4 for Mg Rechargeable Batteries

Abstract

A method for coating cathode active material for magnesium-ion batteries was proposed using polymer, a poly(styrene-4-sulfonyl trifluoromethane sulfonyl)imide Mg salt (PSTFSI-Mg) having a trifluoromethane sulfonyl imide side group. A cathode active material, MgCo2O4 (MCO), was used and spray-dried with PSTFSI-Mg. After preparing the cathode, the Mg battery test was performed with glyme electrolyte solution. The polymer-coated MCO cathode-based coin cell showed good cyclability with moderate discharge capacity around 45 mAh g−1, and this indicates that the polymer thin layer on the MCO surface probably acts as artificial solid electrolyte interface and prevents electrolyte decomposition.