Dual Intercalating Molten Electrolyte Batteries

The reductive and oxidative intercalation of ions into graphite from room‐temperature and low temperature molten salts is demonstrated. For this investigation, the molten salts use 1‐ethyl‐3‐methylimidazolium (EMI + ) or 1,2‐dimethyl‐3‐propylimidazolium (DMPI + ) as the cation and , , , , or as the anion. In a two‐electrode battery configuration, the molten salt electrolyte provides both the cation and anion which are intercalated into the graphite anode and cathode, respectively. A cell employing a electrolyte and two graphite rod electrodes achieved an open‐circuit voltage of 3.5 V and a cycling efficiency of 85%.