Bi2O3-Incorporated V2O5 Nanocomposite: Enhanced Structural, Optical, and Electrochemical Properties for Supercapacitor Applications

The present work is an attempt to explore the impact of bismuth oxide (Bi2O3) at different concentrations (5%, 10%, and 15%) on the structural, optical, and electrochemical features of hydrothermally synthesized V₂O₅ nanoparticles. Structure characterization via X-ray diffraction (XRD) confirmed that the orthorhombic phase of V₂O₅ remains in all composite samples, with slight changes caused by Bi2O3. The study of optical properties involved DRS-UV, and the results pointed to the band-gap gradual increase, notably for 15 % Bi2O3 sample. The shape changes as well as the particle distribution changes due to the composite formation were confirmed by FE-SEM-EDX. XPS study showed that the pure V₂O₅ chemical environment had been changed after the addition of Bi2O3. Electrochemical evaluations, achieved by cyclic voltammetry and charge-discharge cycling, revealed considerable improvements in capacitance as well as stability. The 15% Bi2O3/V2O5 nanocomposite electrode demonstrated exceptional cycling durability with the largest specific capacitance (487 F g⁻¹ at 1 A g⁻¹), and outstanding retention of 89% after 5000 cycles among the investigated concentrations. The assembled asymmetric device with 15% Bi2O3/V2O5 nanocomposite and activated carbon attained an exceptional energy density of 38.4 Wh kg⁻¹ and a power density of 16,000 W kg⁻¹.