Superionic Bifunctional Polymer Electrolytes for Solid‐State Energy Storage and Conversion

Abstract Achieving superionic conductivity from solid‐state polymer electrolytes is an important task in the development of future energy storage and conversion technologies. Herein, a platform for innovative electrolyte technologies based on a bifunctional polymer, poly(3‐hydroxy‐4‐sulfonated styrene) (PS‐3H4S), is presented. By incorporating OH and SO3H functional groups at adjacent positions in the styrene repeating unit, “intra‐monomer” hydrogen bonds are formed to effectively weaken the electrostatic interactions of the SO3− moieties in the polymer matrix with embedded ions, promoting rich structural and dynamic heterogeneity in the PS‐3H4S electrolyte. Upon the incorporation of an ionic liquid, interconnected rod‐like ion channels, which allow the decoupling of ion relaxation from polymer relaxation, are formed in the stiff motif of the polymeric domains passivated by interfacia…