In-Situ Growth of Broussonetia-Like NiCo2O4 on Carbon Cloth with Tailored Aqueous Capacitance

Tailored broussonetia-like NiCo2O4 is grown on carbon cloth using tri-sodium citrate assisted hydrothermal method. The chelating effect of citric ions has been utilized to investigate the morphological and structural evolution of NiCo2O4 on carbon cloth, which have been illustrated by scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectra. The results demonstrate that the morphological alteration of NiCo2O4 from single nanowire to broussonetia-like structure has been detected after the addition of tri-sodium citrate. Citric ion plays a crucial role as an electrostatic stabilizer in determining this unique structure. When used as binder-free electrode in aqueous supercapacitors, the broussonetia-like NiCo2O4 electrode exhibits a specific capacitance of 527.9 F g(-1) at a current density of 0.5 A g(-1). Additionally, an asymmetric supercapacitor is further assembled using NiCo2O4 as the positive electrode and activated carbon as negative electrode. The device exhibits a maximum energy of 26.4 Wh kg(-1) at power density of 800 W kg(-1). A long-term cycling stability with 82% capacitance retention is maintained after 20,000 cycles at a current density of 5 A g(-1), indicating the practical applicability of the tested device.