Synthesis And Applications Of Polyindole Modified Electrode Materials

Supercapacitors are widely used energy conversion devices which are closely related to people's lives.In order to meet the application of supercapacitors in energy storage field,high-performance electrode materials need to be developed.The conductive polymer-modified electroactive materials have excellent electrochemical performances,which are of great significance for improving the performance and application range of the supercapacitors.In this dissertation,polyindole(PIn)is used as a modification layer to modify electrode materials like carbon nanotubes(CNTs)and MnO2,and the electrochemical performances of them as well as their's composite were researched.The work mainly includes the following three aspects:(1)PIn-modified CNTs(CNTs/PIn)were synthesized by in-situ redox polymerization and the dispersibility of CNTs in water was significantly improved.When the mass ratio of CNTs and indole monomer is 2:3,the electrochemical performance of CNTs/PIn reaches the best.After composited CNTs/PIn with reduced graphene oxide(RGO),the dispersibility of RGO in water is also significantly improved.While the mass ratio of CNTs/PIn to RGO is 1:2,the electrochemical performance of the CNTs/PIn/RGO composite is the best.And the composite modified glassy carbon electrode(GCE)shows a specific capacitance value of up to 383 Fg-1 at 1 Ag-1.(2)MnO2 nanotubes were modified with PIn to improve the stability and conductivity of MnO2 nanotubes.When the mass ratio of MnO2 nanotubes to indole monomer is 10:1,the electrochemical performance of MnO2/PIn is the best.When MnO2/PIn is compounded with RGO,the stability and conductivity of MnO2 are further increased,and 5:1 is the best mass ratio of MnO2/PIn to RGO.It was found that the specific capacitance of MnO2/PIn/RGO composite was as high as 448.5 F g-1 at 1 A g-1,and the capacitance retention rate remained.97.65%after 5000 cycles at a current intensity of 10 A g-1.(3)Oxidized carbon fiber cloth(OCF)with excellent capacitance performance is obtained by oxidizing a common carbon cloth.After gold plating on the surface of OCF,a thick layer of MnO2 was deposited on the electrode's surface by electrochemical deposition.PIn was modified on the surface of an OCF@Au@MnO2 multilayer electrode,and an OCF@Au@MnO2@PIn electrode was prepared and used as the positive electrode of an all-solid asymmetric supercapacitor(ASSC).The PIn and Au layers improved the stability and conductivity of MnO2 at the same time,resulting in a specific area capacitance value of 6.08 F cm-2 at 4 mA cm-2.With an operating voltage window of 1.6 V,the power density of the OCF@Au@MnO2@PIn//OCF@Co3O4@RGO ASSC provides a unit area energy density of up to 1.83 mWh cm-2 while achieving a power density of 3.2 mW cm-2.