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.