Effect of Chelating Agent Concentration on the Pseudocapacitive Performance of V2O5 Flakes Prepared by the Hydrothermal Process for Supercapacitor Applications

Abstract

Vanadium pentoxide (V₂O₅) flakes were synthesized via a hydrothermal method by varying the amount of lemon juice (5 mL for sample-1 and 10 mL for sample-2) as a natural chelating agent. Structural and morphological analyses were performed using X-ray diffraction (XRD) and scanning electron microscopy (SEM), confirming crystalline V₂O₅ with flake-like morphologies influenced by chelating agent concentration. Electrochemical performance was evaluated using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) in a 3 M KOH electrolyte. Sample-2 exhibited a Significantly higher Specific capacitance of 1536 F g⁻¹ (CV at 1 mV s⁻¹) and 212.37 F g⁻¹ (GCD at 1 A g⁻¹) compared to sample-1, demonstrating that increasing lemon juice concentration enhances the capacitive behavior of V₂O₅ flakes by improving ion diffusion and electroactive surface area.