High-Performance Layer-by-Layer Self-Assembly PANI/GQD-rGO/CFC Electrodes for a Flexible Solid-State Supercapacitor by a Facile Spraying Technique

We constructed a flexible solid-state supercapacitor based on carbon fiber cloth on which a graphene quantum dot-reduced graphene oxide solution and an aqueous polyaniline solution are alternatively sprayed. An acidic gel is used as both the electrolyte and the binder, by which two plates of electrodes are glued together, forming a symmetrical capacitor. The graphene quantum dot-reduced graphene oxide modifies the hydrophobic nature of carbon fiber cloth, which enhances the interactions between carbon fiber cloth and polyaniline. Additionally, under the strong electrostatic forces between the electropositive polyaniline and the electronegative graphene quantum dot-reduced graphene oxide, a self-assembled three-dimensional fiber-like network on carbon fiber cloth is observed. The fabricated solid-state supercapacitor shows a maximum capacitance of 82.9 mF cm–2 (1036 F g–1) at a 0.1 mA cm–2 current density referenced to the active materials on the electrodes, with a high stability of 97.7% retention after 10000 charge and discharge cycles, because of the strong interaction between polyaniline and the modified carbon fiber cloth. Moreover, the capacitance is unchanged upon bending. This facile layer-by-layer self-assembly spraying technique shows great advantages of easy operation, good controllability, and versatility and can be used universally for the fabrication of foldable and wearable photoelectric devices.