Effect of various aqueous electrolytes on the electrochemical performance of α-MnO2 nanorods as electrode materials for supercapacitor application

Abstract We report a facile one-step hydrothermal method to prepare α-MnO2 nanorods for their application as electrode materials for high-quality supercapacitors. The structural and morphological properties of the prepared active materials were investigated using Powder X-ray Diffraction (XRD) and High-Resolution Transmission Electron Microscopy (HR-TEM) analyses. Fourier Transform-Infrared Spectroscopy (FT-IR) and Bruner-Emmert-Teller (BET) analyses were used to study the functional groups and surface area properties of the α-MnO2 nanorods. Further the electrochemical supercapacitive performance of α-MnO2 nanorods were evaluated using Cyclic voltammetry (CV), Chronopotentiometry (CP), and Electrochemical impedance spectroscopy (EIS) analyses in various aqueous electrolytes (1 M Na2SO4, 0.5 M KOH and 1 M Na2SO4+0.5 M KOH). The electrochemical results show that the α-MnO2 nanorods delivered a high specific capacitance of 570F/g at 1A/g current density in the mixture electrolyte consisting of 1 M Na2SO4 and 0.5 M KOH. In addition, a coulombic efficiency of ~80% was found at 10 A/g current density. And also, the capacitance retention was found to be ~80% after 10,000 cycles in 1MNa2SO4+0.5 M KOH mixture aqueous electrolyte solution. The present work revealed the excellent performance of α-MnO2 nanorod electrode materials in the mixture aqueous electrolyte solution. This electrode-electrolyte combination was found to be the prospective system for supercapacitor applications.