Hierarchical grass-like NiCo2O4 nanowires grown on nickel foam as a binder-free supercapacitor electrode

Abstract

Hierarchical interconnected grass-like NiCo2O4 nanowires are successfully developed on conducting nickel foam as a binder-less supercapacitor electrode. The hydrothermally synthesized electrode delivered a gravimetric specific capacitance of 361 Fg−1 and a high rate capability of 84 % at a high current density of 5Ag−1. An enhancement in the cycling behavior with excellent capacitance retention of 105 % is achieved after 2000 continuous charge–discharge cycles. The remarkable performance could be ascribed to the porous hierarchical grass-like morphology of NiCo2O4 and the 3D interlinked scaffold of conducting nickel foam. The novel grass-like NiCo2O4/Ni can be considered a promising electrode for supercapacitor application.