Zwitterionic Copolymer‐Supported Ionogel Electrolytes: Impacts of Varying the Zwitterionic Group and Ionic Liquid Identities

Abstract

AbstractA series of copolymer scaffolds containing zwitterionic (ZI) functional groups, synthesized in situ in two alkylimidazolium cation‐based ionic liquids, has been created by using two different ZI monomers to yield nonvolatile ionogel electrolytes that exhibit high ionic conductivities and a wide range of elastic moduli. Although all of the examined ionogel formulations consist of 80 mol % ionic liquid, gel properties are observed to depend both on zwitterion content within the copolymer scaffold, as well as the specific ionic liquid/zwitterion pairing. Low zwitterion contents (ca. 1 mol %) generate a notable increase in ionogel room‐temperature ionic conductivity compared to that of their non‐ZI ionogel analogues, whereas higher zwitterion contents (up to 18.5 mol %) yield stiff gels containing a large density of ZI noncovalent cross‐links. This highlights the dual functionality of the ZI groups within zwitterion‐containing copolymer‐supported ionogel electrolytes. All the ionogels synthesized in this study exhibit room‐temperature ionic conductivity values in the range of 3–12 mS cm−1 with compressive elastic modulus values varying between approximately 1–1000 kPa, suggesting their suitability for the design of safer flexible electrochemical devices, including wearable sensors or supercapacitors.