Laser Induced Synthesis And Patterning Of Graphene Composites For Applied To Supercapacitor Devices

Compared with conventional secondary batteries,supercapacitors have the advantages of fast charging and discharging speed,good cycle stability,and low environmental pollution,and have been applied in the field of power type energy storage batteries.However,the rigid characteristics of conventional supercapacitors limit its widespread application in the field of miniature wearable electronic devices.Flexible graphene-based supercapacitors are not only light,thin,and tough,but also have higher energy and power density,and thus become research hotspots in the field of flexible electronics.Conventional graphene preparation methods such as redox and mechanical stripping require complicated high-cost high-temperature processing or multi-step chemical reactions,and the product quality is generally not high,which limits the application of supercapacitors field.In this paper,in-situ rapid low-cost synthesis of graphene electrodes was achieved by laser-induced methods,and the specific capacitance of graphene electrodes was further improved by the introduction of pseudocapacitor through metal oxide MnOx doping,achieve high energy storage density graphene-based flexible supercapacitors.The laser-induced graphene generation technology studied in this paper can synchronously realize the rapid preparation of electrode materials,accurate picture engraving and pseudocapacitor doping,and has wide application value,which is expected to provide valuable reference for the practical development of flexible graphene-based supercapacitors.The main research results of this dissertation are as follows:(1)Laser-induced carbonization technology is used to prepare high-quality graphene in-situ on polyimide film materials,and its patterning is achieved synchronously,which greatly simplifies the preparation process of graphene electrodes.(2)Preparation The Mn3O4 doped polyimide produced MnO/graphene composite electrode material by reducing Mn3O4 into MnO with introduction pseudocapacitor while laser-induced preparation of graphene,and When the speed is 0.1 V/s,the specific capacity reached 73.5 mF/cm2.the specific capacitance is more than 96%after 3000 times of cyclic volt-ampere charge and discharge,indicating that this simple synchronous doping process can obtain supercapacitor electrode material with extremely high specific capacity and excellent cycle performance;(3)Based on the MnO/graphene composite electrode,the all-solid-state flexible supercapacitor was assembled with a specific capacity of 23.7mF/cm2,and when the sweep rate was 0.2V/s,the specific capacitance was more than 91%after 8000 times of cyclic voltammetry charge and discharge.It shows that the electrochemical properties of the graphene composite electrode material are excellent after being deviceized,and it is a practical value of the flexible wearable electronic device.