FeVO4/rGO as high-performance supercapacitor electrode: synthesis and characterization

Abstract Supercapacitors show excellent potential as promising devices for storing energy. In this paper, a facile, economical, and scalable hydrothermal strategy was used to prepare iron-vanadium oxide nanoparticles encapsulated by graphene nanosheets (FeVO₄/G), which were used as a supercapacitor anode material. After systematically investigating and optimizing the reaction conditions, TEM images showed that the 8–12 nm iron-vanadium oxide nanoparticles were encapsulated by the graphene nanosheets. These interconnected graphene nanosheets significantly enhanced electrochemical activity by shortening the electrolyte-to-electrode pathway for the diffusion of ions. At 1 A g⁻ ¹, FeVO₄/G realized an exceptional specific capacitance of 647 F g⁻ ¹ while maintaining 80.5% capacitance retention during extended operation (cycling 10,000 times), highlighting its outstanding stability. Electrochemical impedance measurements indicated favorable kinetic properties, with FeVO₄/G exhibiting low solution (0.47 Ω) and charge transfer (1.28 Ω) resistances. This suggests effective electron transfer and ionic diffusion processes. The superior performance of FeVO₄/G as an electrode demonstrates its strong potential for real-world energy storage solutions.