One-pot synthesis of flower-like Ni-Co/reduced graphene oxide layered double hydroxide nanocomposites as advanced electrodes for high-performance asymmetric supercapacitors

Abstract

Novel electrode materials with appropriate architectures are always desired to increase the energy density of supercapacitors. Here, the design and fabrication of NiCo-layered double hydroxides (NC-LDH) in composition with reduced graphene oxide (rGO) were prepared as high-performance electrodes for supercapacitors. In particular, a facile and one-pot scheme was designed for the growth of NC/rGO-LDH composites, which exhibited a high specific surface area of 204 m2/g. The compositional features of the composites, i.e., a two-dimensional flower-like layered architecture and conductive rGO, contributed to their highly impressive specific capacitance (1913.5 F/g at 1 A/g) and excellent cyclic performance. Furthermore, an asymmetric supercapacitor was designed using NC/rGO-LDH composites as the positive electrode and activated carbon as the negative electrode, which displayed a high energy density of 59.2 Wh/kg at a power density of 750 W/kg.