▎ 摘　　要

To meet the demand of high-performance electrode materials for supercapacitors, it is highly desirable to design and develop a new class of electrode materials with superior electrochemical performance. Here, we used a simple hydrothermal method to synthesize NiCo2S4-anchored graphene nanosheets (NiCo2S4/GNS) for high-performance supercapacitors. Benefiting from the synergistic effect of graphene and NiCo2S4, the as-prepared composite exhibits outstanding electrochemical performances, such as high specific capacitance (1063 Fg(-1) at current density of 2 Ag-1) and excellent cycling performance while maintaining 82% of the initial value after 10000 cycles. Furthermore, an asymmetric supercapacitor (ASC) is fabricated using NiCo2S4/GNS as positive electrode and nitrogen-doped graphene as negative electrode. The fabricated ASC delivers a remarkable energy density of 54.6 Whkg(-1) at a power density of 350.8 Wkg(-1). The outstanding performances render such composite a promising candidate for application of high-energy-density supercapacitors.