Cathode Optimization for All-Solid-State Lithium Sulfur Batteries

Future electric aircrafts will require energy storage systems with high specific energy (ideally > 500 Wh/kg) but non-flammable, for which all-solid-state lithium-sulfur (Li-S) batteries are a top choice. However, one of the major bottlenecks in attaining the full potential of all-solid-state Li-S batteries is achieving high S utilization while maximizing energy density by using higher S content and higher cathode mass loadings. Since S is electrically non-conductive, the increased loading of S would reduce both ion and electron transport throughout the composite cathode, and thus detrimental to S utilization. Therefore, the composition and the interfaces within the cathode need to be optimized to achieve a balance between increased S content and maximal utilization. In this presentation, we discuss our strategy in preparing cathode composites with various compositions while fine tuning the interfaces of active material S with the solid electrolyte and the carbon additive. By evaluating the cathode performance differences, key parameters and processes in optimizing S utilization for balanced energy density performance may be identified.