Thermoplastic Elastomeric Bottlebrush Copolymer Glue Electrolyte Featuring Dual‐Ion Transport Channels and Strong Segregation: Experimental and Simulation Insights

Abstract Despite extensive research on electrolytes for energy storage devices, thermoplastic systems that exhibit elasticity, adhesiveness, and nanostructures remain largely unexplored. Herein, a multifunctional thermoplastic elastomeric glue electrolyte is reported based on a poly(vinyl alcohol) ‐g‐ poly(2,2,3,3‐tetrafluoropropyl methacrylate) (PVA ‐g‐ PTFP) bottlebrush copolymer. Grafting superhydrophobic PTFP side chains onto the hydrophilic PVA backbone induces amphiphilic characteristics, facilitating nanoscale‐domain formation, controlling crystallinity, and enhancing chain mobility. The high Flory–Huggins interaction parameter ( χ = 0.78 at 25 °C) between segments promotes microphase separation and enables dual‐ion transport pathways: cations preferentially interact with PVA domains, while anions coordinate within the PTFP‐rich domains. Experimental and theoretical analyses confirm the presence of intermolecular interactions, well‐organized nanostructures and enhanced ion transport properties. The optimized solid electrolyte exhibits high ionic conductivity, a wide electrochemical stability window, outstanding mechanical elasticity, and notable universal adhesion to diverse surfaces, effectively functioning as an “elastomeric glue electrolyte” enabled by pronounced phase segregation. When used in solid‐state supercapacitors, the bottlebrush system achieves significantly higher performance than the neat PVA system and ranks among the top‐performing materials reported for activated carbon‐based electrodes, even without encapsulation. This showcases a promising strategy to design flexible, high‐performance polymer electrolytes via molecular engineering of thermoplastic bottlebrush copolymers