Highly Ionic Conductive, Stretchable, and Tough Ionogel for Flexible Solid-State Supercapacitor.

Abstract

The increasing demand for wearable electronics calls for advanced energy storage solutions that integrate high electrochemical performances and mechanical robustness. Ionogel is a promisingcandidate due to its stretchability combined with high ionic conductivity. However, simultaneously optimizing both the electrochemical and mechanical performance of ionogels remains a challenge. This paper reports a tough and highly ion-conductiveionogel through ion impregnation and solvent exchange. The fabricated ionogel consists of double interpenetrating networks of long polymer chains that provide high stretchability. The polymer chains are crosslinked by hydrogen bonds that induce large energy dissipation for enhanced toughness. The resultant ionogel possesses mechanical stretchability of 26, tensile strength of 1.34MPa, and fracture toughness of 4175Jm-2. Meanwhile, due to the high ion concentrations and ion mobility in the gel, a highionic conductivity of 3.18Sm-1 at room temperature is achieved. A supercapacitor of this ionogel sandwiched with porous fiber electrodes provides remarkable areal capacitance (615mFcm-2 at 1mAcm-2), energy density (341.7µWhcm-2 at 1mAcm-2), and power density (20mWcm-2 at 10mAcm-2), offering significant advantages in applications where high efficiency, compact size, and rapid energy delivery are crucial, such as flexible and wearable electronics.