A Lithium/Dissolved Sulfur Battery with an Organic Electrolyte

Prototype cells of the configuration Li/∼5M S as , THF, have been characterized with regard to capacity, rate, and rechargeability. Virtually 100% of the theoretical capacity could be realized at 50°C at rates below 1.0 mA/cm2. In high rate cell configurations, 75% cathode utilization is possible at ∼4 mA/cm2 (C/3–C/4 rate). The capacities at high rate are enhanced by Lewis acids, although the ultimate cause of rate limitation is passivation of the current collector by discharge products. The self‐discharge rates of Li in contact with 4–5M S (as ) solutions reveal capacity losses of 0.5%/day at 25°C to 4.4%/day at 71°C. Based on the experimental results, a practical energy density of ∼300 W‐hr kg−1 is possible using a standard cell design. Results on the battery's rechargeability are briefly reviewed.