Controllable synthesis of flowerlike α-MnO2 as electrode for pseudocapacitor application

Manganese dioxide (MnO2) with controllable morphological structures was successfully deposited on stainless steel by electrodeposition using 0.01 M of Mn(CH3COO)2·4H2O as a source material. Temperature was the main synthesis parameter used to control the rate of morphological evolution of MnO2 and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectrum (EDX). The electrochemical performance of MnO2 electrode has been investigated using cyclic voltammetry (CV) and galvanostatic charge discharge in 0.5 M Na2SO4. Specific capacitance of MnO2 electrode increases with increase of temperature and a maximum specific capacitance of 238 F/g has been obtained for MnO2 heated at 150 °C. Continuous charge–discharge cycling studies showed a good stability of pseudocapacitor at which the specific capacitance remained at 84% after 1900th cycle.