A novel β-MnO2 and carbon nanotube composite with potent electrochemical properties synthesized using a microwave-assisted method for use in supercapacitor electrodes

Abstract

In this work, we report the synthesis of a novel β-MnO₂/CNT nanocomposite with good electrical conductivity for high-performance supercapacitors via a microwave-assisted method. The structure and surface morphology of the synthesized nanocomposite were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) analysis, and scanning electron microscopy (SEM). Furthermore, the electrochemical performance of both pure β-MnO₂ and the β-MnO₂/CNT composite was tested by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge (GCD). The β-MnO₂/CNT composite electrode displays an enhanced specific capacitance of 263.8 F g⁻¹ at 0.5 mA cm⁻². The β-MnO₂/CNT composite shows an outstanding capacitance retention and 98.7% capacitance can be retained after 5000 galvanostatic cycles in a neutral Na₂SO₄ electrolyte. These remarkable electrochemical characteristics of β-MnO₂/CNTs proved that the microwave approach is a powerful tool for creating electrode composites. This study demonstrates the potential performance of nanostructured β-MnO₂/CNT electrodes in high-power-density supercapacitor applications.