Solvothermal preparation of microspherical shaped cobalt–manganese oxide as electrode materials for supercapacitors

Microspherical shaped cobalt–manganese oxide (CMO) as electrode materials for supercapacitor is synthesized by solvothermal method. The microstructure and surface morphology of CMO are characterized by X-ray diffraction and scanning electron microscopy, respectively. Cyclic voltammetry and chronopotentiometry are employed for the characteristics of electrode process and the calculation of specific capacitance in KOH solution. It is shown that as prepared CMO with cobalt/manganese mole ratio of 1:2 has excellent specific capacitance of 348.0 F g−1 at current density of 0.5 A g−1. In addition, long-term stability of the composites electrode is measured at current density of 1.0 A g−1, and 58.6% of initial capacitance is retained after 500 cycles.