Construction of NiCo₂O₄@NiFe LDHs core/shell nanowires array on carbon cloth for flexible, high-performance pseudocapacitor electrodes

NiFe layered double hydroxides (LDHs), a class of ionic layered compounds with high electrochemical activity, possess great potential in the field of pseudocapacitive energy storage. However, the practical applications of NiFe LDHs in supercapacitors are largely hindered by their inherently poor cycling life and low electrical conductivity. In this work, NiFe LDHs electrodeposited on mesoporous and conductive NiCo₂O₄ nanowire arrays that are grown on flexible carbon cloth, are investigated as active materials for pseudocapacitive application. This rational core/shell electrode design promises high specific surface area, shorten electron and ion transport distance for the enhancement of electrochemical kinetics. As such, a high specific capacitance (1.9 F cm⁻² at 1 A cm⁻², and 1160 F g⁻¹ at 1 A g⁻¹), excellent rate capability (83% retention as the current density was increased from 1 A cm⁻² to 20 A cm⁻²), decent cycling stability (79% retention after 1000 charging/discharging cycles), and good flexibility have been obtained, implying their potential application as energy storage devices for flexible electronics.