In situ growth of urchin-like NiCo2S4 hexagonal pyramid microstructures on 3D graphene nickel foam for enhanced performance of supercapacitors

Abstract

Urchin-like NiCo₂S₄ hexagonal pyramid microstructures have been grown in situ on three dimensional (3D) graphene nickel foam (GNF) by two-step hydrothermal method, labeled as NCS-GNF. The presence of graphene between nickel cobalt sulphur (NCS) and nickel foam (NF) can effectively improve ion and charge transportation. As a binder-free electrode for supercapacitors, it exhibits an ultrahigh specific capacitance of 9.6 F cm⁻² at 10 mA cm⁻² with excellent rate performance and cycling stability at a mass loading of 5.8 mg cm⁻², corresponding to a mass specific capacitance of about 1650 F g⁻¹ at 1.7 A g⁻¹. The excellent electrochemical performance of urchin-like NCS-GNF is attributed to its unique microstructure. This unique microstructure electrode material has a promising application for capacitors in future.