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 degrees C manifest a relatively high pseudocapacitance of 920 Fig 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. (C) 2016 Elsevier B.V. All rights reserved.