Honeycomb-like NiCo2O4 films assembled from interconnected porous nanoflakes for supercapacitor

Abstract

Honeycomb-like NiCo2O4 films consisting of interconnected nanoflakes were directly grown on conductive substrates via a H2O-EG assisted synthesis. After being annealed at different temperatures, the resultant NiCo2O4 nanoflakes possess abundant pores, which are more favorable for enhanced electrochemical properties. In particular, when evaluated as a binder-free electrode of supercapacitors, such porous structures annealed at 300 °C manifest a relatively high pseudocapacitance of 920 F/g at a very high current density of 40 A/g, the great capacitance retention at 16 A/g after 3000 charge/discharge cycles and high rate capability, which holds great promise for high-performance supercapacitors.