Strong and Ultratough Ionogel Enabled by Ingenious Combined Ionic Liquids Induced Microphase Separation

Abstract Ionogels have become a popular material in flexible electronics and soft robotics based on their excellent ionic conductivity, environmental tolerance, and electrochemical stability. However, it remains a challenge to develop an ionogel integrated with high strength, toughness, self‐healing, and adhesion. Herein, a novel strategy is established to design a high‐strength (0.97 MPa) and tensile (980%), excellent crack insensitivity, self‐healing ionogel based on the cosolvent method. By virtue of differential interactions between the specific polymer and various ionic liquids with gradient polarity, cosolvent systems are employed to achieve high‐performance ionogels by a simple one‐step polymerization. Gel permeation chromatography, atomic force microscopy, time‐domain nuclear magnetism, and density functional theoretical calculation are used to analyze the reasons. Microphase separation can be induced by hydrone or stretching to enhance strength of the ionogel. Therefore, ionogels can be assembled as strain and temperature sensors to monitor human movement and person's body temperature with a low detection threshold (0.1 °C) in extreme environments. This concept creates a new path to achieve soft materials with high performance, and provide a prospective strategy to regulate the in situ microphase change and performance of the resulting ionogel via the one‐step polymerization.