The Lithium/Sulfuryl Chloride Electrochemical Cell

The development of a practical sulfuryl chloride‐based lithium/oxyhalide cell technology has been delayed by anode corrosion and cathode polarization problems encountered when the standard oxyhalide cell electrolyte and cathode formulations are used. The anode stability problem can be significantly alleviated by the use of a reverse polarity cell design, the substitution of for as the electrolyte salt, and the addition of a suitable cosolvent ( or ). Further, at least under ambient temperature storage and discharge conditions, anode passivation is completely absent with hermetically sealed cells of this type. Cathode polarization can be reduced most effectively by the use of a supported platinum cathode material. This cathode material also results in substantially increased discharge capacities, although the overall reaction stoichiometry is unaffected by the catalyst. Finally, thermal decomposition measurements indicate that, as the temperature of the electrolyte in a hermetic cell is increased from 25° to 80°C, the pressure differential across‐the cell case will rise to about 3.5 atm. Then, as the temperature is decreased to a lower value, the pressure differential will also decrease to the equilibrium value characteristic of that lower temperature, indicating a thermally stable, reversible system.