Facile synthesis of an all-in-one graphene nanosheets@nickel electrode for high-power performance supercapacitor application

Abstract

We report a facile and novel approach for the fabrication of all-in-one supercapacitor electrodes by in situ electrochemical exfoliation of flexible graphite paper (FGP) on a nickel collector. The binder-free three dimensional (3D) graphene nanosheets@Ni (GNSs@Ni) supercapacitor electrodes exhibit a high specific capacitance of 196.4 F g⁻¹ and 36.2 mF cm⁻², respectively, at a scan rate of 50 mV s⁻¹. Even at the high scan rate of 2500 mV s⁻¹ the specific capacitance of the capacitor still shows a retention of 85.6% (168 F g⁻¹, 31 mF cm⁻²). Meanwhile, the as-prepared electrode offers excellent cycling performance with 91.5% capacitance retention after 100 000 charging–discharging cycles even at the high current density of 11 A g⁻¹. Such high rate capability, specific capacitance and exceptional cycling ability of the GNSs@Ni electrode are attributed to the all-in-one architecture which provides unique properties including high electrical conductivity, large specific surface area and excellent electrochemical stability. We anticipate that these results will shed light on new strategies to synthesize high-performance hybrid nanoarchitectures electrodes using the prepared graphene nanosheets as the support, which offers great potential in energy storage devices and electrochemical catalysis applications.