Construction of hierarchical MOF-derived CoS2 microsheet arrays@NiMo2S4 nanoflakes on Ni foam as a high-performance supercapacitor electrode

The reasonable design of electrode material composition and structure is an effective way to solve the low energy density of supercapacitors. In this paper, hierarchical MOF-derived CoS2 microsheet arrays@NiMo2S4 nanoflakes on Ni foam (CoS2@NiMo2S4/NF) was prepared by the co-precipitation, electrodeposition and sulfurization process. MOF-derived CoS2 microsheet arrays on NF are used as ideal backbones to provide fast transport channels, and NiMo2S4 nanoflakes with a network-like distribution on the CoS2 microsheet arrays can improve the accessible active sites and promote the penetration and transfer of electrolyte ions. Due to the synergistic effects between the multi components, CoS2@NiMo2S4 exhibits excellent electrochemical properties. The specific capacity of CoS2@NiMo2S4 is 802 C g-1 at 1 A g-1. Hybrid supercapacitor assembled by CoS2@NiMo2S4 and activated carbon exhibits an energy density of 32.1 Wh kg-1 at a power density of 1130.3 W kg-1 and a cycle stability of 87.2% after 10, 000 cycles. This confirms the great potential of CoS2@NiMo2S4 as a supercapacitor electrode material.