Porous CoO nanobundles composited with 3D graphene foams for supercapacitors electrodes

CoO nanobundles composited with 3D graphene foams (CoO NB@GF) in which CoO NB consisted of porous nanoflakes are uniformly and closely bonded with GF were prepared by the combination of chemical vapor deposition, hydrothermal method and thermal treatment. The CoO NB@GF composites showing lightweight and high conductivity can serve directly as supercapacitors electrodes (including current collectors) without any other conductive agents and binders. The cyclic voltammetry and galvanostatic charge/discharge measurements on CoO NB@GF electrodes demonstrated a high specific capacitance of 352.75 F/g (221.75 F/g scaled to total mass of electrodes) at 1 A/g current density, good rate performance and nearly no decay of the specific capacitance after 1000 charge/discharge cycles at 10 A/g current.