Preparation,Properties And Supercapacitors Application Of Conductive Polymer/Graphene Composites

Due to its excellent electrochemical performance,supercapacitors have become the main research focus of researchers,in the hope of meeting the needs of today's growing energy storage equipment.The key to preparing a supercapacitor with excellent performance is the reasonable choice of electrode materials.Graphene has a large specific surface area,high electrical conductivity and excellent thermal stability.On the other hand,aniline tetramer is a cost-effective material for supercapacitor electrode due to its very good electrical conductivity,unique ion doping mechanism,high specific capacitance,and simple production process.At the same time,MnO2 is favored because of abundant resources,good cycle stability,environmental friendliness and high theoretical specific capacitance.This thesis mainly reported on the preparation of binary or ternary composites of reduced graphene oxide with short-chain aniline tetramer?AT?and MnO₂ for supercapacitor electrode materials.The main contents are listed as follows:1.GO/AT nanocomposites were prepared by self-assembly under the action of static electricity between graphene oxide?GO?prepared by a modified Hummers method and aniline tetramer?AT?prepared by a chemical method.Reduced graphene oxide and AT?RGO/AT?composite nanomaterials were then prepared using hydrothermal reduction of GO to RGO.The microstructure and structure of the RGO/AT composites were characterized by scanning electron microscopy?SEM?,Fourier transform infrared spectroscopy?FTIR?,X-ray diffraction?XRD?,Raman spectroscopy and X-ray photo-electronic spectroscopy?XPS?.Moreover,the electrochemical performance of RGO/AT nanocomposites with different amounts of AT was tested using cyclic voltammetry?CV?and galvanostatic charge-discharge method.Results have shown that the sample with an AT loading of 50 mg has high specific capacitance?476.3 F/g at a current density of 1 A/g?,rate performance?79.2%specific capacitance retention can be obtained when the current density increases 50 times?and cycle stability?after 1000 cycles,its preserved specific capacitance is 92.2%?.2.RGO/MnO₂ nanocomposites were prepared via a one-step method.Aniline tetramer?AT?prepared chemically was then self-assembled on the surface of the RGO/MnO2 nanocomposites under electrostatic action to prepare RGO/MnO2/AT nanocomposites.The microstructures and structures of RGO/MnO₂ nanocomposites and RGO/MnO₂/AT nanocomposites were characterized by SEM,FTIR,XRD Raman spectroscopy and XPS.The electrochemical performance of RGO/MnO₂ nanocomposites was tested by CV and constant current charge and discharge method.The RGO/MnO₂nanocomposites with 1/3 manganese addition?RGM3?has a high specific capacitance of147.1 F/g at a current density of 1A/g.Furthermore,the electrochemical performance tests were performed on the electrodes prepared by self-assembly of RGM3 and different AT addition amounts.RGO/MnO₂/AT nanocomposites with 50 mg AT addition?RGMA2?have good specific capacitance?497.9 F/g at 1 A/g?,rate performance?74.9%specific capacitance retention can be obtained when the current density increases 50 times?and good cycle stability?after 4000 cycles,its preserved specific capacitance is 81.5%?.3.Graphene hydrogel?GH?was prepared by a chemical reduction method,and then aniline tetramer was directly deposited on GH using chemical polymerization.The resultant GH/AT nanocomposites were used for supercapacitor research.SEM,FTIR,XRD,Raman spectroscopy and XPS were used to characterize the morphology and structures of GH and GH/AT.Results demonstrate that AT was successfully inserted into the GH layers to form three-dimensional?3-D?structured nanocomposites.The resulting nanocomposites were futher characterized using CV,AC impedance,and constant current charge and discharge method,and the results show that the GH/AT nanocomposites have a good electrochemical performance,including high specific capacitance?567.7 F/g at 1 A/g?and good cycle stability?after 1000 cycles,its preserved specific capacitance is 93%?.This is mainly due to the high conductivity,rich pores and excellent mechanical stability of GH and the high specific capacitance of AT.Therefore,the GH/AT nanocomposites could be used as a promising supercapacitor electrode material.