Fluoro‐Functionalized Polyether Electrolytes Enabling High‐Energy‐Density Solid‐State Lithium‐Metal Batteries

Due to their non‐flammability, remarkable flexibility, ease of processing, and design versatility, polymer‐based electrolytes containing polyethers have emerged as pivotal materials for high‐energy‐density and safe lithium‐metal batteries. Although polyethers provide sufficient sites for Li + transport through ether‐oxygen coordination, they still exhibit low room temperature ionic conductivity and poor oxidation stability, which remains a critical obstacle to the commercialization of lithium‐metal batteries. Given fluorine's strong electronegativity and the excellent stability of C–F bonds, fluorination strategies have proven effective in enhancing the oxidative stability of polymer‐based electrolytes and extending the cycling life of lithium‐metal batteries. Notably, incorporating fluorine into ether‐based polymer‐based electrolytes can simultaneously improve ionic conductivity, mechanical properties, and the formation of stable electrode/electrolyte interfaces. In this review, we comprehensively examine the design of fluoro‐functionalized polyether electrolytes for advanced lithium‐metal batteries and their impact on battery performance. Our primary objectives are to elucidate the structure–property relationships of fluoro‐functionalized polyether electrolytes and to explore their mechanisms in improving interfacial stability and electrochemical performance. Furthermore, we discuss the key challenges and future development directions of fluoro‐functionalized polyether electrolytes for solid‐state lithium‐metal battery applications, and propose practical strategies to address these issues.