Stretchable and self-healing 2,5-dihydroxy-1,4-benzoquinone/polyacrylamide composites for high-performance all-solid-state flexible supercapacitors

The escalating demand for foldable and bendable electronic products underscores the pressing necessity for flexible energy storage devices that offer enhanced reversibility, stability, and efficiency. In this context, organic electrodes have emerged as a focal point of study owing to their tunable structures and remarkable electrochemical characteristics. Thus, designing and constructing organic composite electrodes with electrochemically active material is of paramount importance. Herein, 2,5-dihydroxy-1,4-benzoquinone (DHBQ), an electrochemically active organic molecule, is introduced as a novel material stabilized by a network of abundant hydrogen-bonding interactions. Reduced graphene oxide (rGO) is incorporated to enhance charge transfer, while polyacrylamide (PAM) serves as a flexible framework. These components are integrated through a free radical cross-linking polymerization and solvent substitution process. Density functional theory (DFT) simulations elucidate the synergistic mechanism involving hydrogen bonding and π-π interactions among PAM, DHBQ, and rGO. The optimized DHBQ/rGO/PAM-0.5 electrode exhibits remarkable mechanical flexibility and self-healing ability, with a tensile strain of up to 917%. Electrochemical tests reveal an areal specific capacitance of 809 mF/cm 2 at a current density of 1 mA/cm 2 . The fabricated flexible supercapacitor based on this electrode demonstrates an energy density of 42.3 μWh/cm 2 at a power density of 0.79 mW/cm 2 . Notably, the device maintains its electrochemical performance without degradation under bending conditions ranging from 0° to 180°. The development of this innovative composite combining stretchability, self-healing ability, and excellent electrochemical properties offers a promising approach to designing high-performance flexible electrodes.