Potentiostatic and galvanostatic electrodeposition of manganese oxide for supercapacitor application: A comparison study

Abstract

The structural and electrochemical properties of manganese oxide (MnO 2) electrodeposited by potentiostatic and galvanostatic conditions are studied. X-ray diffraction analyses confirm identical MnO 2 phase (ramsdellite) are deposited under potentiostatic and galvanostatic conditions. Under comparable current density during electrodeposition, MnO 2 deposited by galvanostatic condition shows smaller crystallite size, less compact layered structure, higher surface area and wider band gap, in comparison to the potentiostatic deposition. The MnO 2 morphology difference under different electrodeposition conditions contributes to different capacitive behaviors. The lower compactness of MnO 2 deposited galvanostatically renders facile ions diffusion, leading to higher specific capacitance with low equivalent series resistance. The findings suggest galvanostatic electrodeposition is suitable to produce MnO 2 nanostructure for supercapacitor application.