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.