Stacking-Free Three-Dimensional Graphene Electrode Architecture for Ultrahigh Interfacial Charge Storage

Abstract

Supercapacitors are receiving considerable attention as energy storage devices for portable and wearable electronics. Their large-scale commercialization hinges on the design and development of cost-effective, stable electrode materials with high surface area and exceptional conductivity. This study reports the design and synthesis of an organic linker-based three-dimensional reduced graphene oxide (3D-rGO) as a potential electrode material for high-energy supercapacitors. Characterization shows that the crafted 3D-rGO is a robust microporous 3D network with a specific surface area as high as 930 m2/g. Electrochemical tests reveal that 3D-rGO possesses outstanding charge storage capabilities, achieving a specific capacitance of approximately 470 F/g at 10 A/g and an energy density of around 65.3 Wh/kg at a power density of 5000 W/kg. Additionally, it exhibits exceptional cyclic stability, retaining 120% of its capacitance after 5000 cycles. A prototype flexible symmetric device utilizing 3D-rGO as the electrode material and PVA-H2SO4 as the gel electrolyte exhibits a specific capacitance of 44 F/g, an energy density of 12.05 Wh/kg (at 2 A/g), and an impressive 98.4% capacitance retention after 10,000 cycles at 5 A/g. These findings underscore the potential of 3D-rGO as a cost-effective and highly efficient electrode material for high-energy charge storage applications.