Nitrogen-doped double-layer graphite supported CuCo2S4 electrode for high-performance asymmetric supercapacitors

Abstract

CuCo2S4 synthesized on the nitrogen-doped double-layer graphite (NDG) inter-layer revealed more uniform and smaller size than synthesized directly on Ni foam. From electrochemical measurements, the specific capacitance of CuCo2S4@NDG electrode was 1244 F g−1 at a current density of 50 A g−1, which was twice higher than the CuCo2S4@Ni electrode. In addition, the reduced graphene oxide (rGO) was used to assemble CuCo2S4@NDG//rGO asymmetric supercapacitor, revealing a high energy density (58.4 W h kg−1) for practical applications. Significantly, the NDG inter-layer improved the properties of asymmetric supercapacitor at high-rate and high energy density conditions effectively.