One-step preparation of Ni3S4 quantum dots composite graphene/carbon nanotube conductive network for asymmetric supercapacitor

In this reported work, Ni3S4 quantum dots (QDs) composite graphene/carbon nanotube (G/CNTs) composites were prepared using a one-step method. Among them, graphene is produced by carbon nanotubes and Ni catalyst. G/CNTs can not only prevent the agglomeration of Ni3S4 QDs, but also preclude this insulating drawback caused by the interface of QDs. XPS analysis data showed that after adding G/CNTs to Ni3S4 QDs, the electron interaction was stronger, which promotes the electron transport in the material. The electrochemical test results of the electrode material showed that G/CNTs increased the specific capacitance of the Ni3S4 QDs by 4.5 times and its rate capability from 22% to 82%. The energy density of asymmetric supercapacitor assembled with electrodes containing the Ni3S4 [email protected]/CNTs and activated carbon achieved 50 Wh kg−1. This work provides a reasonable way for improving the electrochemical performance of supercapacitor electrode materials.