Enhanced Electrochemical Performance of Supercapacitors Using Fe ₃ O ₄ ‐Doped Biomass‐Derived Activated Carbon Electrodes

ABSTRACT The energy storage performance of supercapacitors—defined by specific capacitance, energy density, and power density—is strongly influenced by the structural and electrochemical properties of electrode materials. While cathode development has advanced significantly, research on efficient and sustainable anode materials remains limited, hindering further improvements in energy density. This study presents a low‐cost, sustainable anode material derived from Abelmoschus esculentus (AE) seed biomass. Activated carbon (AE‐AC) was prepared via chemical activation and subsequently coated with magnetic Fe 3 O 4 nanoparticles synthesised through co‐precipitation to form an AE‐AC‐doped Fe 3 O 4 nanocomposite. The materials were characterised using XRD, SEM–EDX, BET surface area analysis, and other techniques. Electrochemical performance was evaluated using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS). At a scan rate of 2.5 mV/s, both electrodes exhibited peak capacitance. GCD analysis showed specific capacitances of 119.97 F/g for AE‐AC and 205.86 F/g for AE‐AC‐doped Fe 3 O 4 at 0.05 A/g. EIS results confirmed enhanced performance of the nanocomposite in acidic medium. These findings highlight the potential of AE‐based activated carbon composites as environmentally friendly and efficient anode materials for next‐generation supercapacitors.