CTAB-assisted one-pot hydrothermal synthesis of Co0.85Se as a promising cathode material for magnesium ion battery

Co0.85Se with Cetyl-trimethylammonium bromide (CTAB) prepared by the one-pot hydrothermal method is used as a cathode material for magnesium ion battery (MIB) for the first time. It exhibits higher initial capacity (348 mAh/g) and reversible capacity (127 mAh/g) than that of the untreated Co0.85Se. The obvious improvement can be ascribed to the enhanced conductivity and the lowered charge-transfer resistance (Rct) when CTAB is introduced. Moreover, the two-step magnesium storage mechanism of Co0.85Se-CTAB in MIB is investigated. This work provides a novel method to enhance the electrochemical properties of metal selenides as electrodes for magnesium ion batteries by adding CTAB cationic surfactants.