Construction of CoMoO4 nanorods wrapped by Ni-Co-S nanosheets for high-performance supercapacitor

In this study, the Ni-Co-S nanosheets have been grown onto CoMoO4 nanorods by the electrodeposition method (CoMoO4 @NCS). The supercapacitor performance of the CoMoO4 @NCS composites can be greatly promoted due to the unique core-shell structure. The addition of amorphous Ni-Co-S nanosheets can provide much more electrochemical active sites, thereby enhancing the capacitive capability. The CoMoO4 @NCS composites show fairly high specific capacitance of 1276 F g−1 at 0.5 A g−1, which is twice that of pristine CoMoO4 nanorods (604 F g−1). The composites also present remarkable cycling characteristics. The specific capacitance retention reserves 98 % after 7000 cycles at 1 A g−1. Furthermore, the asymmetric supercapacitor (CoMoO4 @NCS//AC) device exhibits high energy density of 48.3 Wh kg−1. Notably, the fabricated device also presents outstanding stability with only 4% capacitance loss rate after 10000 cycles. The results indicate that the CoMoO4 @NCS composites have great potential for energy storage materials.