Screen-Printable and Flexible RuO2 Nanoparticle-Decorated PEDOT:PSS/Graphene Nanocomposite with Enhanced Electrical and Electrochemical Performances for High-Capacity Supercapacitor

This work describes a ternary screen-printed electrode system, composed of aqueous poly(3,4- 4 ethylenedioxythiophene):poly(4-styrenesulfonic acid) (PEDOT:PSS), graphene, and hydrous ruthenium(IV) oxide (RuO2) nanoparticles for use in high-performance electrochemical capacitors. As a polymeric binder, PSS allows stable dispersion of graphene and hydrous RuO2 nanopartides (NPs) in an aqueous PEDOT:PSS system through electrostatic stabilization, ensuring better utilization of the three components. Additional PSS molecules were added to optimize the solution viscosity to obtain screen-printed electrodes. The effects of graphene and hydrous RuO2 NPs on the electrical and electrochemical properties of PEDOT:PSS were systematically investigated. The graphene sheets greatly enhanced the charge-transport properties, such as the doping level and conjugation length, through strong 3r-n- stacking interactions with the PEDOT structure. The hydrous RuO2 NPs anchored to the PEDOT:PSS/graphene surfaces facilitated redox reactions with the surrounding electrolyte, and significantly enhanced the specific capacitance of the electrode materials. The resulting Ru02/PEDOT:PSS/graphene electrode with a thickness of 5 gm exhibited high conductivity (1570 S cm(-1)), a large specific capacitance (820 F g(-1)), and good cycling stability (81.5% after 1000 cycles).