Non-​Nucleophilic Electrolyte Based on Ionic Liquid and Magnesium Bis(diisopropyl)​amide for Rechargeable Magnesium-​Ion Batteries

Abstract

A non-nucleophilic electrolyte for rechargeable Mg-ion batteries is developed by the reaction of magnesium bis(diisopropyl)amide and 1-ethyl-3-methylimidazolium tetrachloroaluminate ionic liquid in tetrahydrofuran solvent. The electrolyte shows excellent reversibility and Coulombic efficiency for the Mg deposition/stripping process at room temperature on several working electrodes such as Mo, graphite, and stainless steel. Additionally, the electrolyte shows high anodic stability with Mo as the cathode current collector, with no corrosion detected even after 48 h at 4.5 V versus (Mg/Mg2+). An exceptional cyclability in a full cell configuration using a Chevrel phase Mo6S8 cathode is achieved with a capacity retention of more than 80% for over 300 cycles at a 15 mA g–1 specific current, making this electrolyte an excellent candidate for rechargeable Mg-ion batteries.