Microwave synthesis of three dimensional N-doped graphene self- supporting networks coated with Zinc/Nickel oxide nanocrystals for supercapacitor electrode applications

摘要

Abstract A hybrid of zincickel oxide nanoparticles supported on nitrogen doped three-dimensional graphene networks (ZnO/NiO/3DNG) have been designed through a simple microwave process assisted tube furnace thermal treatment. Well dispersed coupled zincickel oxides nanoparticles with sizes of 10–20 nm are homogeneously anchored on 3DNG hybrid structure. As electrode active material of supercapacitors, the ZnO/NiO/3DNG nanocomposites exhibits an ultrahigh specific capacitance of 1839.4 F g_(−1)at a current density of l A g_(−1)in 6.0 M KOH solution, the EIS analysis of the electrode after 6000th cycle at 10 A g_(−1)remained about 93%, displayed that the fitting values of inner resistance and faradic charge transfer resistance of the electrode are low and electrode activity don’t change too much after cycling. Furthermore, the ZnO/NiO/3DNG composites exhibits the maximum energy density of 35.32 Wh kg_(−1)with the power density 139.72 W kg_(−1)at high current density of 10 A g_(−1)in the two-electrode system. The outstanding performance originates from the flexible three dimensional N-doped unique structural, which play important roles in stabilizing ZnO and NiO.