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 AlCl4-, BF4-, PF6-, CF3SO3-, or C6H5CO2- 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 (DMPI)(AlCl4) electrolyte and two graphite rod electrodes achieved an open-circuit voltage of 3.5 V and a cycling efficiency of 85%.