Three-dimensional network-like amorphous NiCo-LDH nanofilms coupled with Co3O4 nanowires for high-performance supercapacitor

Abstract

A network-like structure consisting of an amorphous nickel–cobalt layered double hydroxide nanofilm anchored to Co3O4 nanowires (Co3O4/NiCo-LDH) is grown on nickel foam via hydrothermal reaction and electrochemical deposition. The complex interlocking network-like structure provides three-dimensional interconnected porous channels for electron transport and ion diffusion, and provides optimal access to active sites; this results in rapid Faradaic redox reactions. This intriguing advantage gives the optimal Co3O4/NiCo-LDH electrode outstanding electrochemical performance, with an ultrahigh specific capacity of 1067 C g-1, and high rate performance, with 73.28% capacity retention at 20 A g-1. When it is combined with an activated carbon (AC) electrode, the Co3O4/NiCo-LDH//AC device exhibits a maximum energy density of 74.4 Wh kg-1 at a power density of 989 W kg-1 and excellent cycling stability, with 91.57% retention after 7000 cycles. This study provides new options and an important foundation for rational design of network-like structures for application in hybrid supercapacitors.