Lithium‐Sulfur Battery: Evaluation of Dioxolane‐Based Electrolytes

The lithium‐sulfur battery recently developed in our laboratory shows 95%+ sulfur utilization but low rate capability due to its poorly conducting electrolyte, which is based on a THF:toluene solvent mixture. In order to increase the rate capability of this cell, dioxolane‐based electrolytes have been evaluated. The conductivity of electrolytes consisting of mixtures of THF, toluene, and dioxolane were measured in the temperature range −30° to +60°C. The compatibility of lithium with these electrolytes was also studied. It was found that dioxolane‐rich electrolytes are compatible with lithium and have one order of magnitude higher conductivity than do THF:toluene‐rich electrolytes. However, sulfur utilization in dioxolane‐rich electrolytes is only 50%, even at a very low discharge rate. This is due to a different discharge product, namely, .