Anode‐Less Sulfide‐Based All‐Solid‐State Batteries: Interfacial Challenges, Material Strategies, and Future Prospects

Anode‐less sulfide‐based all‐solid‐state batteries (ASSBs) have emerged as promising candidates for next‐generation energy storage, offering high energy density, enhanced safety, and simplified cell design. By eliminating excess lithium (Li) metal and relying solely on Li extracted from the cathode, these systems significantly improve gravimetric and volumetric performance. However, the absence of a Li reservoir introduces critical challenges, particularly at the Li|solid electrolyte (Li|SE) interface. This review first outlines the fundamental interfacial and electrochemical challenges in anode‐less sulfide systems, including unstable Li plating/stripping, void formation, interfacial contact loss, and parasitic reactions that lead to poor reversibility and early failure. Drawing from recent experimental studies, the second part of this review discusses material and structural strategies developed to stabilize these systems. These include current collector modifications, lithiophilic and alloying interlayers, cathode prelithiation, and artificial interphase engineering, each aiming to suppress dendrite growth, enhance interfacial integrity, and manage Li inventory. The review concludes by highlighting future research directions and design principles essential for realizing scalable and commercially viable anode‐less sulfide‐based ASSBs. By critically evaluating the latest progress, this work aims to provide a comprehensive framework to guide the rational development of robust and high‐performance solid‐state battery architecture.