<p>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&#xa0;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 a good specific capacitance of 647 F g⁻¹ while maintaining 80.5% capacitance retention during extended operation (10,000 cycles), 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 asymmetric supercapacitor (ASC) was assembled using the FeVO₄/G composite as the anode and reduced graphene oxide (rGO) as the cathode. Remarkably, the resulting FeVO₄/G//rGO asymmetric supercapacitor achieved an energy density of 12.8 W h kg⁻¹ at a power density of 0.4&#xa0;kW&#xa0;kg⁻¹. The superior performance of FeVO₄/G as an electrode demonstrates its strong potential for real-world energy storage solutions.</p>