Scalable Interfacial Engineering with Lithiophilic‐Lithiophobic Layers for High‐Performance All‐Solid‐State Li‐Metal Batteries

Abstract The stability of the lithium‐metal/solid electrolyte interface remains a critical challenge in the development of all‐solid‐state lithium‐metal batteries (ASSLMBs), as it directly influences their cycling performance, rate capability, and safety. Here, a thin, flexible, and lithium‐stable sulfide electrolyte membrane is presented with high ionic conductivity (3.25 × 10 ⁻³ S cm ⁻¹ ) and low electronic conductivity (1.45 × 10 ⁻⁹ S cm ⁻¹ ) at room temperature, prepared with an AlCl ₃ coating in a low‐cost wet process. The in situ formation of a lithiophilic Li‐Al alloy and a lithiophobic LiCl layer at the interface creates a stable dual‐layer structure, effectively suppressing Li‐dendrite growth and enhancing Li‐transport across the interface. Symmetric Li/Li cells with this coated membrane exhibit exceptional cycling stability, operating for over 10000 h at 0.5 mA cm ⁻² . ASSLMBs assembled with a LiNi _0.8 Co _0.1 Mn _0.1 O ₂ cathode and a metallic lithium anode exhibit excellent cycling performance, highlighting the potential of this coating strategy to stabilize the Li/solid electrolyte interface and expedite the commercialization of ASSLBs.