Preparation and electrochemical performance of spherical MnOx with high capacitance

A promising electrode material, MnO x , was prepared by chemical precipitation method using MnSO 4 · H 2 O as manganese source and (NH 4 ) 2 CO 3 as precipitant. The as-prepared manganese oxide was characterized by field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), and X-ray diffraction (XRD), respectively. The effects of reaction temperature and calcination temperature on the electrochemical properties of the electrode materials were investigated. The results show that MnO x with a spherical morphology exhibits an excellent performance in the energy storage field. Under the optimal experimental conditions, the specific capacitance of pure MnO x reaches up to 592 F g −2 in the alkaline media when the current density is 5 mA cm −2 over the potential window from −0.3 to +0.4 V. The combination resistance and transfer resistance of MnO x are 0.86 and 0.08 Ω, respectively. These findings make MnO x a promising electrode material for electrochemical capacitors.