α-NiS grown on reduced graphene oxide and single-wall carbon nanotubes as electrode materials for high-power supercapacitors

Abstract

α-NiS nano-particles grown on reduced graphene oxide (rGO) and single-wall carbon nanotubes (SWNTs) as high-performance electrode materials for supercapacitors have been synthesized by a one-step solvothermal method. Compared to rGO, the introduction of SWNTs results in an obvious improvement of the electronic conductivity and keeps the α-phase crystal growth of NiS as well. The obtained NiS/SWNTs composite possesses outstanding electrochemical performance, giving high specific capacitances of 1110 F g⁻¹ and 825 F g⁻¹ at high current densities of 5 A g⁻¹ and 50 A g⁻¹, respectively, along with excellent cycling stability. Compared with rGO, the incorporation of SWNTs is more advantageous not only for preventing the aggregation of NiS particles but also for the construction of a highly conductive network, which allows neighboring NiS particles to achieve excellent high rate capacitances.