Tailored Engineering on the Interface Between Lithium Metal Anode and Solid‐State Electrolytes

The replacement of non‐aqueous organic electrolytes with solid‐state electrolytes (SSEs) in solid‐state lithium metal batteries (SLMBs) is considered a promising strategy to address the constraints of lithium‐ion batteries, especially in terms of energy density and reliability. Nevertheless, few SLMBs can deliver the required cycling performance and long‐term stability for practical use, primarily due to suboptimal interface properties. Given the diverse solidification pathways leading to different interface characteristics, it is crucial to pinpoint the source of interface deterioration and develop appropriate remedies. This review focuses on Li|SSE interface issues between lithium metal anode and SSE, discussing recent advancements in the understanding of (electro)chemistry, the impact of defects, and interface evolutions that vary among different SSE species. The state‐of‐the‐art strategies concerning modified SEI, artificial interlayer, surface architecture, and composite structure are summarized and delved into the internal relationships between interface characteristics and performance enhancements. The current challenges and opportunities in characterizing and modifying the Li|SSE interface are suggested as potential directions for achieving practical SLMBs.