Preparation of Y-doped ZrO2 coatings on MnO2 electrodes and their effect on electrochemical performance for MnO2 electrochemical supercapacitors

Abstract

To enhance the cycling stability and conductivity of manganese dioxide (MnO₂) electrodes for supercapacitors, yttrium (Y) doped zirconia (ZrO₂) (denoted as Y/ZrO₂) is coated on MnO₂ supercapacitor electrodes (Y/ZrO₂@MnO₂ electrodes), so protecting the MnO₂ electrodes in the electrolytes and enhancing the electrochemical performance of MnO₂ electrodes in sodium sulfate electrolytes. The Y/ZrO₂@MnO₂ electrodes are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX) and XRD analysis. The electrochemical properties of the electrodes are tested and analyzed by galvanostatic charge/discharge tests, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The Y/ZrO₂@MnO₂ electrodes achieve a specific capacity of 282.1 F g⁻¹ with a specific capacity loss of only 6.3% after 100 cycles at the current density of 50 mA g⁻¹. The results show that MnO₂ particles are successfully deposited by Y-doped ZrO₂ while the Y/ZrO₂@MnO₂ electrodes display better cycling stability and capacity performance. Therefore, this Y-doped ZrO₂ coating is a potential choice to improve the cycling stability and conductivity of MnO₂ electrodes.