Interface Compatibility in Sulfide-Based All-Solid-State Batteries: Challenges and Strategies at the Electrode–Electrolyte Interfaces

Sulfide-based all-solid-state batteries (SASSBs) are compelling candidates for next-generation energy storage due to their high ionic conductivity and compatibility with lithium metal. Nevertheless, the poor chemical and mechanical compatibility at electrode–electrolyte interfaces remains a central obstacle to practical implementation. This review focuses exclusively on interfacial compatibility challenges and solutions for both the anode–electrolyte(AEI) and cathode–electrolyte interfaces(CEI) in sulfide-based solid electrolytes systems. We delineate the principal mechanisms of interfacial instability, including physical debonding, chemomechanical degradation, and lithium dendrite nucleation and propagation. We, then systematically assess recent strategies such as artificial solid electrolyte interphase (SEI) engineering, interlayer design, in-situ interphase formation, cathode surface coatings, and composite interface architectures. Furthermore, we integrate results from advanced characterization techniques and multiscale simulations to clarify the interfacial processes that control performance. Finally, we propose future research directions aimed at interfacial stability, manufacturability, and multi-layer integration. In summary, this review offers a solution oriented roadmap for engineering robust interfaces in commercially relevant SASSBs.