Three-dimensional graphene oxide/polypyrrole composite electrodes fabricated by one-step electrodeposition for high performance supercapacitors

Abstract

Three-dimensional (3D) graphene oxide/polypyrrole (GO/PPy) composite electrodes have been fabricated via one-step electrochemical co-deposition in an aqueous solution containing pyrrole monomers, GO and LiClO₄. The concentration of GO in the solution plays an important role in controlling the morphologies of the as-deposited GO/PPy composites, and a relatively low concentration of 0.1 mg mL⁻¹ is favorable for the formation of a 3D interconnected structure. The unique 3D interconnected structure ensures fast diffusion of electrolyte ions through the electrode. As a result, the GO/PPy composite electrode with a mass loading of 0.26 mg cm⁻² exhibits the highest specific capacitance of 481.1 F g⁻¹, while the electrode with a larger mass loading of 1.02 mg cm⁻² delivers the best area capacitance of 387.6 mF cm⁻², at a current density of 0.2 mA cm⁻². Moreover, the GO/PPy composite electrodes exhibit good rate capability with capacitance retentions over 80% when the current density load increases from 0.2 to 10 mA cm⁻². Both the aqueous and solid-state supercapacitors based on GO/PPy composite electrodes show excellent capacitive properties with good cycling stability, indicating their suitability for applications in energy storage and management.