Toward high-performance all-solid-state supercapacitors using facilely fabricated graphite nanosheet-supported CoMoS4 as electrode material

Abstract

Hybrids of graphite nanosheet-supported CoMoS4 (GN-CoMoS4) were synthesized through a hydrothermal method. The CoMoS4 nanoparticles are uniformly distributed on the graphite nanosheets, leading to large specific surface area and good electrical conductivity. The GN-CoMoS4 hybrids were systematically studied for electrode materials of supercapacitors. Due to the amorphous characteristic of CoMoS4, which can supply more transportation channels for ion diffusion, together with the large specific surface area and excellent conductivity of GN, the as-prepared hybrid electrode material exhibited a high specific capacitance of 774 F g−1 at the current density of 1 A g−1 and an excellent cyclic stability (94.49% of its initial specific capacitance retained after 6000 cycles at a current density of 8 A g−1). An all-solid-state asymmetric supercapacitor was fabricated using GN-CoMoS4 as positive electrode and porous active carbon (AC) as negative electrode, which exhibited a highest energy density of 42.85 W h kg−1 at 900 W kg−1 and excellent cycling stability (93.2% retention after 8000 cycles). The results demonstrate that the GN-CoMoS4 hybrids are promising candidate for the electrode materials in high-performance supercapacitors because of the well-designed microstructure.