Preparation Of Supercapacitor Electrode Materials Based On Three Dimension Graphene And Their Performance Of Capacitance

As a new kind of carbon materials,,graphene has broad application in the supercapacitor electrode materials due to its excellent properties.Recently,3DG with 3D pore structure makes it have larger specific surface area,higher mechanical performance and faster electron transfer rate,which makes them gain extensive attention from the researchers.This paper introduces a preparation method on Zn foils to rapidly grow three dimension graphene and successfuliy fabricated the controllable macroscopic size 3D electrode materials with high specific capacitance.The method is easy, friendly, low cost and provide a potential for commercial application of 3D graphene. the influence factors of specific capacitance on 3D graphene were investigated,such as acid solution concentration, reaction time and concentration of the GO and the optimum preparation conditions were then obtained. Under best preparation conditions, the thickness of three dimension graphene grown on Zn foils was thin,there was not seriously stack between layer and layer and it provides a well spatial three-dimensional channel structure.The capacitance of electrode materials could reach 117.1F/g under the current density of 1 A/g.At the same time, the specific capacitance of capacitor can keep 95.8% of initial value after 2000 cyclic voltammograms cycling cycles under scanning rate of 100 mv/s,showing rather good cycle stability.The MnO2/3DG composite electrode materials were prepared by one-step hydrothermal methods,which were convenient,green and environmental friendliness. Through the means of without reducing agent and adding surface active and reducing agent, R-MnO2/3DG and SMnO2/3DG composite materials were respectively prepared. The Mn O2 particles of RMnO2/3DG composite electrode material are smaller, well dispersed and no reunion phenomenon. The capacitance value of R-MnO2/3DG composite electrode material is higher, which is superior to R-MnO2/3DG. Explored preparation conditions of R-MnO2/3DG composite materials and got the best preparation conditions: the MnO2 loading mass of 49.5wt%, hydrothermal reaction temperature of 100℃ and hydrothermal reaction time of 8h. R-MnO2/3DG composite electrode material obtains the specific capacitance value of 356.4F/g at current density of 1A/g under the best conditions. Under scanning rate 100 mv/s, the ultimate capacity retention rate is about 92.3% after 2000 cycling cycles.The three dimension graphene load cobalt and nickel bimetallic oxides(NixCoyOz / 3DG) composite materials were prepared by hydrothermal method. Explored the cobalt and nickel ratio(x/y) on its capacitance value.When x/y = 1/2, Nix CoyOz/3DG composite materials have the highest capacitance value. Under the current density of 1 A/g, its specific capacitance obtained 380.9 F/g, which is higher than the capacitance value of R-MnO2/3DG; Under the same conditions,the specific capacitance retention remained 89.8%, which is inferior to RMnO2/3DG composite electrode materials.