Functional Separator Coatings for Lithium/Sodium Metal Batteries: Bridging Academic Research and Industrial Prospects
Jinkui Li, Yun Gao, Xihao Lin, Hang Zhang, Zecong Zhao, Jiaxu Liu, Haizhu Li, Haoxuan Liu, Tingting He, Shulei Chou, Li LiABSTRACT
Lithium/sodium metal batteries (LSMBs) are promising candidates for next‐generation high‐energy‐density storage, yet their practical deployment remains constrained by dendrite formation, unstable electrode‐electrolyte interfaces, and safety risks. Functional separator coatings offer an attractive strategy for stabilizing metal anodes because they are compatible with existing battery manufacturing and can be readily integrated into cell designs. This review provides a comprehensive overview of the evolution from conventional polyolefin‐based separators to advanced functional architectures. The physicochemical mechanisms through which functional coatings regulate ion transport, homogenize metal deposition, suppress dendrite growth, and improve thermal stability are critically reviewed. Representative coating materials, including ceramics, polymers, carbonaceous materials, metal‐organic frameworks, and hybrid systems, are discussed in terms of their structure‐function relationships, advantages, and limitations. The scalability of different coating strategies is evaluated in terms of coating thickness, line speed/throughput, material utilization, equipment requirements, and process continuity, thereby facilitating the selection of appropriate fabrication routes for distinct application scenarios. Finally, key challenges and future directions are outlined to guide rational separator design and practical manufacturing. This review aims to provide mechanistic insights and design principles for translating functional coated separators toward commercially viable metal batteries.