Research On Reduced Graphene Oxide Planar On-Chip Electrodes And Supercapacitors

The development of miniaturize,wearable electronic products have increased the demand for new energy storage system.Planar supercapacitors comes into being because of the advantages of highly compatible,highly energy-storage density and highly integrated with micro-energy storage devices.Planar supercapacitors have a better power characteristics due to the short ion transport path.Graphene as a new member of condensed matter physics,it almost meets all the requirements of the researchers for planar supercapacitors electrode material due to the unique mechanical and electrical properties.In this thesis,the preparation process of graphene oxide,graphene oxide films and reduced graphene oxide films were explored based on the scientific principle of graphite oxidation reduction method.Firstly,GO films were prepared on the silicon wafer with 300 nm oxide layer by layer-by-layer alternating spin-coating method using the graphene oxide aqueous solution with different concentrations as raw materials and the polyethylene aqueous solution with cationic electrical property as binder.Then reduced graphene oxide films as planar on-chip electrodes were received by HI acid reduction as a low temperature.The C/O atomic ratio of reduced graphene oxide films have arrived at 11.55 after characterization.In this thesis,reduced graphene oxide films with different properties were prepared by adjusting the concentration of graphene oxide solution and the number of times of alternating spin coating.The results showed that the electron mobility of reduced graphene oxide films would be increased with the increasing of the concentration of graphene oxide solution in the spin-coating process.Then the conductivity of reduced graphene oxide films would be increased.With the increasing of the number of spin-coating,the conductive properties of reduced graphene oxide films were decreased due to the effect of the polyethylene.After all,the binder polyethylene has insulating properties.Finally,when the concentration of graphene oxide aqueous solution was 2mg/ml,the number of alternating spin coating was one time,the thickness of reduced graphene oxide film was 26.4nm,the conductivity of reducedgraphene oxide film was 766.96Scm-1.In this thesis,we fabricated all-solid-state planar supercapacitors by using reduced graphene oxide films as electrode material based on the research progress of planar supercapacitor.The super capacitor characteristics of planar supercapacitors were investigated by cyclic voltammetry test.The results showed that the lower scan rate,the better cyclic voltammetry of planar supercapacitor and the better capacitance of the device.When scan rate was 50 m Vs-1,the area capacitance was344.89?Fcm-2,the volume capacitance was 43.11Fcm-3 and the energy density was17.24 m Whcm-3.This thesis provides an important reference for the study of all-solid-state planar on-chip supercapacitor based on reduced graphene oxide thin films.