Research Of Integrated Planar Micro-supercapacitors Based On Modified Self-assembled Graphene

At present,electronic devices are developing in the fields of miniaturization,portable,planarization,and integration.As a new type of energy storage element,planar on-chip micro-supercapacitors must not only conform to the development trend,but also improve their overall performance.Meantime,the preparation process of the planar on-chip micro-supercapacitors needs to be simple and can be mass-produced,so that it can provide higher energy for other microelectronic devices and can also be used as a power source for integrated circuits and on-chip micro-nano electronic devices.In this paper,graphene oxide film was prepared by modified liquid-air interface self-assembly method and converted into reduced graphene oxide film after reduced by hydroiodic acid.The thickness of reduced graphene oxide film was only 5nm and the conductivity was calculated to be 975.61 S cm^-1.XPS test and XRD test show that graphene oxide film was effectively reduced and its carbon-to-oxygen ratio was increased from 1.49 to 8.94.In this paper,PMSCs with an electrode gap of the order of 10⁰μm were prepared by photolithography and the electrochemical performance tests are performed.The analysis results show that the equal ratio narrow of the electrode finger width and the gap shortening the ion transmission path and achieving extremely fast charge and discharge rates.The time constant of the planar on-chip micro-supercapacitor with a gap of 6μm was only 2.60μs,which means the device can provide high peak power for large-scale integrated circuits and on-chip micro devices in a very short time.By calculating and analyzing the CV curve,the results show that the micro-supercapacitor with an electrode gap of 6μm had excellent electrochemical performance.Its the surface capacitance,the stack capacitance,energy density and power density were 32.44μF cm^-2and 64.87 F cm^-3,9.01 m Wh cm^-3and 90.40 Wcm^-3,which shows that narrowing the electrode width can improve charge storage capacity and power characteristics.In this paper,a series configuration of planar on-chip micro-supercapacitors is designed.Compared with the series configuration of metal wire connection and graphene electrode connection,this new type of electrode has no additional internal connection,which greatly reduces the internal resistance and energy loss of the intermediate connection,significantly improves the effective area utilization of the device and facilitately to the development of integratable and micro-nano devices.In addition,a single micro-supercapacitor improves the output voltage,The experimental data show that the surface capacitance,energy density and power density of the planar micro-supercapacitor with series structure were 58.94 F cm^-3,8.19 m Wh cm^-3,and 2.45 W cm^-3,respectively.The electrochemical performance of planar micro-supercapacitor with series structure was significantly better than that of a single device.Planar on-chip micro-supercapacitor with winding electrode configuration were prepared before this research work.