Co 3 S 4 nanoneedles decorated on NiCo 2 O 4 nanosheets for high-performance asymmetric supercapacitors

Abstract Co3S4 nanoneedle decorated NiCo2O4 nanosheets are successfully prepared by a two-step hydrothermal process for supercapacitors. The NiCo2O4 nanosheets are served as ideal backbones to enhance the surface area and provide more electroactive sites for faradaic reaction. The optimized NiCo2O4/Co3S4 electrode shows a high specific capacity of 1468 F g−1 at the current density of 1 A g−1. When assembled an asymmetric supercapacitor, the device exhibits high energy density of 14.0 Wh kg−1 at 400 W kg−1, and retains 84.7% of the capacity after 3000 cycles.