In Situ Orthogonal Polymerization for Constructing Fast-Charging and Long-Lifespan Li Metal Batteries with Topological Copolymer Electrolytes

Fast-charging Li metal batteries (LMBs) with low cost, high safety, and long lifespan are highly desirable for next-generation energy storage technologies yet have been rarely achieved. Here, we report the in situ fabrication of well-designed blend, block, and bottle-brush solid-state polymer electrolytes (SPEs) integrating poly(poly(ethylene glycol) methyl ether methacrylate) (PPEGMA) and poly(trimethylene carbonate) (PTMC) matrices via Li-catalyzed orthogonal polymerization. Among them, the bottle-brush topological SPEs may display quasi-molecular-scale miscibility between PPEGMA and PTMC, maximize the synergistic coordination of Li+ with ether and carbonate units at the PPEGMA/PTMC interface, and simultaneously exhibit ideal mass transport properties and a broad electrochemical stability window. Further incorporating trifluoroethyl methacrylate (TFEMA) into the bottle-brush SPE allows facile construction of a robust solid electrolyte interphase (SEI). These, together with the fast charge transfer kinetics inherited from the in situ polymerization technique, enable the development of the first example of solid-state polymeric LMB capable of operating steadily at 3C (73% capacity retention after 1000 cycles).