Reduced graphene oxide/poly(aniline-co-toluidine blue): Binder-free electrodes for high-performance quasi-solid-state symmetric supercapacitors

In this work, we successfully prepare binder-free reduced graphene oxide/poly(aniline-co-toluidine blue) (rGO/PANTB) electrodes. The surface of graphene oxide sheets is efficiently coated with PANTB nano-protrusion structure through in-situ oxidative polymerization. The uniform distribution of this structure efficiently facilitates electron and ion transfer during the charge/discharge process. In addition, rGO is easily and gently obtained by immersing in hydrazine hydrate solution. The prepared rGO/PANTB-4 electrode shows maximum specific capacitance of 809.8F g−1 at current density of 1 A/g and satisfactory long-cycling stability (93.1 % capacitance retention after 5000 charge/discharge cycles) in 1.0 M H2SO4 electrolyte. Additionally, the assembled quasi-solid-state symmetric supercapacitor exhibits high energy density of 26.2 Wh kg−1 at power density of 600.8 W kg−1 in PVA-H2SO4 gel electrolyte. In summary, the construction of copolymer offers a novel approach to enhance the stability of conductive polymer, while incorporating copolymer and rGO represents an effective strategy for enhancing energy storage performance.