DEVELOPMENT OF MNO2/PANI/SWCNT NANOCOMPOSITE SUPERCAPACITOR ELECTRODE AND INVESTIGATION OF ELECTROCHEMICAL PERFORMANCE

Abstract

In this study, a manganese dioxide (MnO2/polyaniline (PANI)/ single-walled carbon nanotube (SWCNT) nanocomposite electrode was prepared for pseudo-supercapacitors. To reduce the internal resistance of the electrode, increase the capacitance stability, and reduce the cost of single-walled carbon nanotubes, SWCNT was subjected to two-step acid etching. The purity of SWCNT was improved from ~95% to 99.98%. In addition, SWCNT was functionalized by this process. Thus, a nanocomposite was formed by coating PANI around SWCNT. MnO2/PANI/SWCNT were synthesized using the hydrothermal method. Morphological, chemical and thermal analyses of the synthesized nanocomposite structure were carried out. In addition, X-ray diffraction (XRD) was used to determine the crystal structure. Electrochemical analyses were performed using a three-electrode system in a 1 M KOH electrolyte solution. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements were performed. The capacitance of the nanocomposite electrode at 400 cycles was 314 mF/cm2, and the capacitance retention stability was calculated at 73.24%. The results showed that the capacitance stability was high, and the supercapacitor was sensitive to redox reactions.