▎ 摘　　要

The optimal use of materials leads to the overall increase in electrochemical performance of SCs. In this work, a novel hierarchical porous N, S doped reduced graphene oxide-NiCo2S4 hybrid nanocomposite was synthesized by in-situ growth of NiCo2S4 over porous rGO framework by a facile hydrothermal process. The materials are optimized by determining the proper ratio of metal ions to graphene in order to obtain optimal supercapacitive performance. The optimum use of materials showed improved nucleation and confined growth of NiCo2S4 nanoneedles over rGO by taking the advantages of high specific surface area and porosity of rGO. The N,S dual doping further enhanced the electrochemical activity by introducing defects in the crystal structure by replacing the lattice C atoms thereby rendering the graphene structure more disordered. The prepared GNCS3 electrode exhibited high specific capacitance (1640F/g at current density of 1A/g). The improved electrochemical activity is due to the synergetic impact of NiCo2S4 and rGO, wherein rGO served as an excellent conductor and ideal framework. The all-solid-state GNCS3//AC ASC fabricated showed excellent electrochemical properties with a specific capacitance of 135F/g at 1A/g, excellent capacitance retention of 92.5 % after 5000 cycles and highest energy density of 27 Wh/kg at a power density of 600 W/kg. The facile synthesis and excellent capacitive behaviour of NiCo2S4/rGO makes it an ideal electrode material for supercapacitor applications.