High conductivity and a large specific surface area triggered electrochemical properties of MnFe2O4-CNTs nanocomposites for energy storage applications

Abstract

In addressing the demand for high-energy-density supercapacitors, the development of electrode materials with a wide potential range and high specific capacitance is crucial for energy storage nanodevices. Ferrite-based nanocomposites are a promising group for electrodes. This study conducts a thorough examination of the structural and electrochemical properties of (MnFe₂O₄)_1-x(CNTs)_x nanocomposites (where x= 0, 0.20, 0.40, 1). MnFe₂O₄ based nanocomposites have been synthesized using a simple, cost-effective, and versatile chemical route through an ex-situ approach. The resulting nanocomposites display a desired pure polycrystalline structure, nanostructured morphology, defective vibrational bonding, and a tuned bandgap toward the visible range. These nanocomposites demonstrate superior electrochemical performance in KOH electrolyte, as compared to an acidic environment. Notably, the (MnFe₂O₄)_0.60(CNTs)_0.40 nanocomposite exhibits a high specific capacitance of 652 Fg^-1 at 10 mVs^-1, which is twice that of the individual host matrix MnFe₂O₄. Additionally, the nanocomposite maintains good cycling stability, retaining up to 81% of its capacity over 1500 cycles with an ESR value of 0.432Ω. The energy and power densities of the nanocomposite as an electrode for supercapacitors have significantly improved to 20.4 Wh/Kg and 900 W/Kg, respectively. This recent work offers a new approach to enhance the performance of MnFe₂O₄-CNTs nanocomposites in environmental and energy storage applications.