Ultra-stretchable ion gels based on physically cross-linked polymer networks

Abstract

A high-performance ion gel composed of poly(ethyl acrylate-co-acrylic acid-co-sodium acrylate) (P(EA-co-AA-co-AANa)) with a high ionic liquid content was successfully fabricated through a simple solution-casting method. It exhibits excellent mechanical strength owing to the various non-covalent interactions between the polymer chains and the entropic elasticity of the highly entangled polymer networks. By adjusting the polymer composition, the ion gel film can achieve a tensile strain exceeding 6000% or a tensile stress exceeding 2.5 MPa. This ion gel also has the advantages of excellent thermal stability, good transparency, high ionic conductivity, and wide electrochemical window. More importantly, the polymer P(EA-co-AA-co-AANa) is easy to synthesize, the monomer is cheap, and the gel preparation is simple, making it possible to realize large-scale production for broad applications in the fields of motion sensors, gel electrolytes, and flexible displays.