An ultra-tough and super-stretchable ionogel with multi functions towards flexible iontronics

Ionogels have attracted much attention in recent years because of their good thermal stability, high ionic conductivity, and non-volatility. However, there is a trade-off between the mechanical strength and stretchability of ionogels, which results in unsatisfactory mechanical performance. Herein, strong polymer crystallization and weak ion-dipole interaction are combined to prepare an ultra-tough and super-stretchable ionogel. The crystalline region can dissipate the energy through the stress-induced disaggregation mechanism in the stretching process and toughen the gel, while the reversible formation and dissociation of the ion-dipole interaction between amorphous polymer chains and ionic liquids can provide elasticity for large strain. These ionogels have high toughness, strong tensile strength, large Young's modulus, and good stretchability. Furthermore, the ionogels also possess other properties like good fatigue resistance, quick self-recovery, high transparency, recyclability, self-healing ability, high ionic conductivity, and wide electrochemical window. This ionogel exhibits great potential in several iontronic devices, such as triboelectric nanogenerators, ionic thermoelectric materials, and strain sensors. This study develops a new method to guide the preparation of high-performance ionogels by combining reversible strong and weak interactions.