Cathode Development for High-Energy All-Solid-State Lithium-Sulfur Battery

The All Solid-State Lithium-Sulfur Battery (ASSLSB) holds great promise in delivering a safe, high energy
density, and low-cost battery technology suitable for vehicle electrification and grid energy storage. To
achieve a practically high specific energy in ASSLSBs (e.g., >400 Wh/Kg), it is essential to develop sulfur cathodes with high areal capacities (>6 mAh cm⁻²) to offset the relatively low working voltage of
elemental sulfur cathodes (1.9 V vs. Li). This necessitates the development of high mass-loading sulfur
cathodes by maximizing both the sulfur content in the electrode and the sulfur utilization rate to reduce
parasitic weights. An optimal electrode architecture featuring sufficiently connected sulfur/solid electrolyte/carbon triple-phase boundaries (TPBs) is crucial to enable rapid electron and Li-ion accessibility to the sulfur simultaneously. However, due to the non-flowable nature of these three solid components, it is challenging to maximize the contact among the solid phases, which requires new insights into materials design and processing technologies. Our research focuses on screening the cathode materials and their impact on the TPBs between electrochemically active sulfur, carbon, and the solid-state electrolyte (SSE) that comprise most composite cathodes in ASSLSB systems. We have developed optimal cathode materials and compatible SSEs to enhance TPB density, achieving an extremely high sulfur utilization rate in high mass-loading sulfur electrodes. The details of our study will be presented and discussed at the meeting.