Electrochemical performance of nitrogen-doped graphene anchored nickel sulfide nanoflakes for supercapacitors

Nitrogen-Doped graphene is reportedly said to be engineered in fine-tuning its electrochemical performance to suit the high energy requirements of supercapacitors. In an attempt, nickel sulfide nanoflakes are anchored on the surface of N-doped graphene under hydrothermal environment. XRD data identifies the pristine sample as nickel sulfide of rhombohedral structure. The pristine nickel sulfide in combination with nitrogen-doped graphene is confirmed by Raman and XRD analyses. The surface morphology of the composite reveals nanoflakes of nickel sulfide non-uniformly grown over the 2D sheets of N-doped graphene. The supercapacitor performance of the as-prepared samples is evaluated in the three electrode set up by CV, GCD and EIS studies. N-doped graphene/Nickel sulfide nanocomposite has demonstrated excellent electrochemical activity of specific capacitance of 1120 F g(-1) at 1 A g(-1) and achieved the cyclic stability of 82% for 3000 charge/discharge cycles. The nanocomposite seems to benefit from the synergistic combination of the nickel sulfide with N-doped graphene to render it with high electrochemical performance metrics.