Eliminating the Detrimental Effects of Conductive Agents in Sulfide-Based Solid-State Batteries

Sulfide-based solid-state electrolytes (SSEs) are considered a key part in the realization of high-performance all solid-state lithium-ion batteries (ASSLIBs). However, the incompatibility between conductive additives and sulfide-based SSEs in the cathode composite challenges the stable delivery of high-rate capability. Herein, a poly(3,4-ethylenedioxythiophene) (PEDOT) modification is designed as a semiconductive additive for cathode composites (cathode/SSE/carbon) to realize the high performance. The modified ASSLIB demonstrates a competitive rate capacity of over 100 mAh g–1 at 1C, which is 10 times greater than that of the bare cathode. Detailed surface chemical and structural evolutions at the cathodic interface indicate the PEDOT modification not only significantly suppresses the side reactions but also realizes effective electron transfer at the cathode/SSE/carbon three-phase interface. Introducing a controllable semiconductive additive for the cathode composites in this study offers a promising design to realize the high-rate performance and overcome long-term challenges in the application of conductive additives in sulfide-based ASSLIBs.