Soft Ionic Materials: Design and Applications in Functional Electrochemical Systems

By integrating the rapid ionic transport of ionic liquids with the structural integrity of polymers, ionogels achieve high conductivity, mechanical flexibility, and environmental stability. These attributes position them as promising solid-state electrolytes for soft electronics. Recent molecular innovations have yielded ionogels with remarkable stretchability, toughness, and multifunctionality, broadening their scope of applications. This Perspective highlights molecular-level strategies, such as copolymer design and dynamic cross-linking via ionic or supramolecular interactions, that tailor polymer-ion interactions and network dynamics. We then discuss how these strategies regulate ionicity, diffusivity, and segmental mobility. These microscopic processes ultimately determine macroscopic transport properties and enable advanced devices such as strain sensors, electrochromic supercapacitors, thermoelectric generators, and triboelectric nanogenerators. Finally, by integrating molecular design with mechanistic insight, we provide a forward-looking framework for developing scalable, robust, and adaptive ionogels that underpin next-generation ionotronic systems.