Wearable super-high specific performance supercapacitors using a honeycomb with folded silk-like composite of NiCo₂O₄ nanoplates decorated with NiMoO₄ honeycombs on nickel foam

Abstract

A novel multi-component and binder-free electrode material of NiCo₂O₄ (NCO) nanoplates adhered to NiMoO₄ (NMO) honeycomb composites was prepared on a nickel foam (NF) using a simple chemical bath deposition strategy. This paper reports the synthesis of a honeycomb composite with folded silk-like NF@NMO@NCO nanostructures on nickel foam and its use to increase the availability of electrochemically active sites to provide additional pathways for electron transport and improve the utilization rate of the electrode materials. As a result, the as-fabricated NF@NMO@NCO electrode exhibited a maximum specific capacitance of 2695 F g^-1 at a current density of 20 mA g^-2, which is much better than that of NF@NCO nanoplates (1018 F g^-1) and NF@NMO honeycomb (1194 F g^-1). Moreover, the as-synthesized NF@NMO@NCO achieved a high energy density of 61.2 W h kg^-1 and outstanding power density of 371.5 W kg^-1 as well as exceptional capacitance retention of 98.9% after 3000 cycles. The outstanding electrochemical performance makes the honeycomb composite with a folded silk-like nanostructure a promising candidate for advanced electrochemical energy storage.