<p>Herein, a simple, one-step method for creating a new electrode out of a CoFe₂O₄@Co₃O₄ nanocomposite is established using a ball milling method. Then, several methods of analysis were used to look at the synthesized composite, including XRD, XPS, SEM, TEM, and HRTEM, to investigate the variation in phase evolution and microstructure. At the current density of 1.5 A g⁻¹, the composite of CoFe₂O₄@Co₃O₄ (10%) exhibits a specific capacitance of 373.5 F g⁻¹. In addition, a hybrid device was constructed employing this composite as a cathode and commercial activated carbon as an anode to evaluate the practical characteristics of the novel electrode, which conducted a specific energy of 28.2 Wh kg⁻¹ at the power density of 887.2 W kg⁻¹; it preserves capacity of 80.3% after 5000 cycles. These results confirmed the electrode’s superior electrochemical performance as a promising electrode for energy storage applications.</p>