Facile preparation of CoMoO4/NiCo2O4 nano-sphere anode materials and their performance in asymmetric supercapacitors

CoMoO4/NiCo2O4 electrodes with a three-dimensional nano-sphere structure have been successfully prepared by a combination of hydrothermal and calcination methods. The electrode material exhibits a high specific capacitance of 1175 F g−1 at 1 A/g, excellent multiplicative performance (74.2 % capacity at 15 A/g) and good cycling stability (85.9 % specific capacitance retention after 10,000 cycles). The asymmetric supercapacitor was constructed using activated carbon (AC) as the negative electrode, showing excellent energy density (27.7 wh kg−1) and power density (806 W kg−1). It also has an extremely long operating life, maintaining a specific capacitance of 78.3 % after 5000 cycles at current densities up to 6 A/g. The results indicate that the synthesized mixed transition metal oxides CoMoO4/NiCo2O4 are promising as composite electrode materials for high-performance asymmetric supercapacitors.