Design and fabrication of nickel vanadium sulfide directly grown on the basis of NiV-LDH nanosheets for high-performance supercapacitors

Herein, nickel-vanadium binary sulfide (NVS) was directly grown on the basis of nickel-vanadium layered double hydroxides (NiV-LDH) using the combination of hydrothermal method and gas-phase vulcanization method, forming a unique structure (NVS@NiV-LDH). The results suggest that the growth of NVS significantly increases the number of active sites and enhances the stability of the structure. The NVS@NiV-LDH electrode reaches a standout specific capacitance of 465.33 F g-1 at a high current density of 6 A g-1 and an excellent cycle stability of 90.69 % after 5000 charge-discharge cycles at 12 A g-1. Furthermore, an asymmetric supercapacitor (NVS@NiV-LDH//AC) was also assembled, achieving a high energy density of 133.98 Wh kg- 1 at a high power density of 15,120 W kg- 1 with a superior cycling stability (82.8 % of its initial specific capacitance after 5000 cycles at 12 A g-1). These results demonstrate an optimistic prospect of the NVS@NiV-LDH in electrode materials for supercapacitor applications.