Influence of surfactant CTAB on the electrochemical performance of manganese dioxide used as supercapacitor electrode material

MnO2 nano hollow sphere was prepared by liquid co-precipitation with different concentrations of cationic surfactant CTAB. The morphology and structure of the prepared MnO2 were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FT-IR) and low temperature nitrogen adsorption. It was revealed that the obtained manganese dioxide was α-MnO2 and the particle size of samples was between 100 and 300 nm. As evidenced by the cyclic voltammetry and galvanostatic charge/discharge test, 0.014 mol/L was found to be the optimum impact concentration of CTAB. The MnO2 synthesized under optimum conditions showed the specific capacitance 178 F/g at the current density of 500 mA/g and its BET area is 229.8 m2/g, compared to the 126 F/g and 178.4 m2/g of the MnO2 synthesized without surfactant.

► The electrochemical performance of MnO2 prepared with CTAB is better than the MnO2 prepared without CTAB universally.
► Introducing CTAB in the preparation process of MnO2 can reduce the agglomeration of manganese dioxide particles and increase the BET surface area of it.
► From the perspective of industrial applications, the prepared manganese dioxide may not necessary need to be washed.