Fabrication of rod-like NiMoO4/CoMoO4 for application in asymmetric supercapacitors

The composite supercapacitor materials can promote overall performance compared with individual materials owing to the synergistic effect. Here, we present a facile and effective method to synthesize NiMoO4/CoMoO4 nanorods by hydrothermal reaction and subsequent calcination. The as-synthesized products have both high capacitance and good stability, and successfully combine the properties of NiMoO4 and CoMoO4. NiMoO4/CoMoO4 nanorods displayed high specific capacitance of 1164 F/g at 2 A/g, and around 75% of capacitance was retained after 3000 cycles at 10 A/g. Especially, the composite materials showed excellent rate capability and around 83% of the capacitance was retained from 2 to 20 A/g. Furthermore, an asymmetric capacitor can deliver an energy density of 23.1 Wh/kg at a power density of 375 W/kg, and an energy density of 17.5 Wh/kg at a high power density of 3750 W/kg. These results indicate NiMoO4/CoMoO4 nanorods have prominent properties, which can be considered as promising material for supercapacitor.