Binder-Free MnO2 Electrodes for Supercapacitor Applications

Abstract

The binder-free MnO2 electrodes are fabricated using the electro-deposition method. X-ray diffraction spectra of the obtained electrodes verified the generation of a pure tetragonal phase of MnO2 without any impurity peak. Further, the morphology of the fabricated electrode is explored by Scanning Electron Microscope, which confirmed the formation of platelets when the deposition time is small, while the flakes are formed as the deposition time is increased. Electrochemical performances for all three fabricated MnO2 electrodes are also conducted in the three-electrode system using the techniques like Cyclic Voltammetry, Galvanostatic Charge Discharge, and Electrochemical Impedance Spectroscopy. The maximum specific capacitance of 531.6 F/g at 0.5 A/g is achieved in the KNO3 electrolyte for the electrode with 15 minutes of deposition time, while the high rate capability is maintained for the electrode with a deposition time of 10 minutes. Therefore, based on the electrochemical performance, fabricated MnO2 electrodes are suitable for supercapacitor applications.