A novel normalAl/Cl2 rechargeable electrochemical cell is described which employs an Al negative and graphite positive electrode in a room temperature molten salt electrolyte of 1.5:1 AlCl3:1,2‐normaldimethyl‐3‐normalpropylimidazolium chloride . The graphite positive electrode functions as a reversible intercalation electrode for chlorine, eliminating the need for separate anolyte and catholyte compartments. The cell possesses an average discharge voltage of 1.7V for currents of 1–10 mA/g graphite and over 150 cycles at 100% depth‐of‐discharge for positive electrode limited cells have been demonstrated. Improvements in the chlorine storage capacity of the positive electrode are needed to obtain satisfactory energy densities.

The preparation and characterization of a new molten salt system prepared from aluminum chloride and a trialkylimidazolium halide is described, particularly those molten salts prepared with 1,2-dimethyl-3-propylimidazolium chloride. Molten salts prepared with this salt are liquid over the composition range of ca. 0.65:1 to 2.2:1 A1C13:DMPrIC1 at 25~A value for the acid-base equilibrium constant of (2.0 -+ 0.5) • 10 -15 was determined by potentiometric titration. Cyclic voltammetry results are presented comparing reduction potentials for MEIC1 and DMPrICI and the electrochemical windows of the respective molten salts. For a 1:1 A1C13:DMPrIC1 molten salt, an electrochemical window of nearly 5V is obtained at glassy carbon.

016ChemInform Abstract A 1.5:1 AlCl3: 1,2-dimethyl-3-propylimidazolium chloride electrolyte is used for the new secondary cell with an Al negative electrode and a graphite positive electrode, which serves as a reversible chlorine intercalation electrode, thus eliminating the need of a separation membrane between anolyte and catholyte compartments. The cell possesses an average discharge voltage of 1.7 V for currents of 1-10 mA/g graphite and over 150 cycles at 100% depth-of-discharge of the positive electrode are obtained. However, the storage capacity of graphite for chlorine is too low to achieve satisfactory energy densities.

014ChemInform Abstract The preparation and characterization of a new molten salt system prepared from AlCl3 and trialkylimidazolium halides is described, particularly those melts containing AlCl3 and (I). Molten salts with (I) are liquid at 25 rc C over the composition range AlCl3:(I) = 0.65-2.2. A value of the acid-base equilibrium constant of 2.0•10-15 determined by potentiometric titration. For a 1:1 AlCl3:(I) molten salt, an electrochemical window of nearly 5 V is obtained at glassy carbon.