Rapid Reduction Of Graphene Oxide Composites For Flexible Supercapacitor Electrode

As an energy storage device,the development of supercapacitors is so fast,and the application range is expanding.This thesis focuses on the research of supercapacitor electrodes in flexible and wearable electronic devices.As typical 2D and 1D carbon nanomaterials,the graphene and carbon nanotubes have been intensively studied in the field of new materials due to their good attributes.It is the focus of this study that different graphene and carbon nanotubes can be effectively combined by different methods.First,according to the improved Hummers method of self-made graphene oxide,mixed with carbon nanotubes and stable binder,and a self-assembly flexible self-supporting composite membrane electrode was synthesized by thermal evaporation and high temperature annealing.The results showed that the combined carbon nanotubes can improve the electrochemical properties of the composite as a whole.By comparing different temperatures,it is indicated that the improvement of the annealing temperature is beneficial to the overall electrochemical performance of the electrode.The area ratio of the electrode annealed at 500 ? reaches the maximum capacitance,and the specific capacitance is 0.8 mA/cm2 at 1 mA/cm2.Moreover,to improve the preparation of composite electrode steps,a flame-like method was used to prepare 3D multi-layer structures similar to carbon aerogels of graphene/carbon nanotube hybrid film.The flame is used for rapid annealing with the reduction of graphene oxide at high temperature,and vertical carbon nanotubes are generated by using NiSO4 as a precursor to suppress the stacking of graphene sheets in the process of burning.It has significant electrochemical properties at a current density of 1 mA/cm2 with a maximum area specific capacitance of 1.6 F/cm2.At a high current density of 4 mA/cm2,a capacitance of 86%remains after 2000 cycles of charging and discharging,indicating a good cycle stability of the electrode.At the same time,the electrode also has very good bending characteristics.It is clear that the electrode prepared by the method meets the requirements of the modern society for flexible and portable wearable electronic devices and has good application prospect.