The Study On Electrochemical Capacitive Properties Of Poly(3,4-ethylenedioxythiophene)Electrodes

As energy storage devices,supercapacitors are usually composed of electrode material,current collector,electrolyte,and separator.The electrode material is one of the important components of supercapacitors,and its properties directly affect the performance of capacitors.Among conducting polymers,poly?3,4-ethylenedioxythiophene??PEDOT?is a common electrode material for supercapacitors because of its high conductivity,chemical stability,fast kinetics and environmental compatibility Etc.Compared with PEDOT prepared by chemical method,PEDOT prepared by electrochemical polymerization can be grown on a current collector in one step to obtain an electrode,thereby avoiding the use of a binder required for preparing an electrode in a chemical method.However,little work has been done to investigate the effects of electropolymerization conditions and current collectors on the electrochemical performance of PEDOT electrodes prepared in detail.Therefore,this paper studies the polymerization conditions and current collectors,and synthesizes poly?3,4-ethylenedioxythiophene?/carbon nanotubes?PEDOT/CNTs?composite electrode,which promotes the application of PEDOT in supercapacitors through this study.The main contents of this paper are as follows:?1?Different PEDOT/PSS electrodes were prepared by changing the electropolymerization parameters?such as polymerization current density,polymerization voltage?,current collector,and anionic dopants.Through this series of research and operations,electrode materials and current collectors with the best chemical properties were found,and eventually supercapacitors were formed in this work.In order to further prove the authenticity of the research results,they need to be characterized by fourier transform infrared?FT-IR?,X-ray diffraction?XRD?,scanning electron microscope?SEM?and atomic force microscope?AFM?images.The final conclusion is that the performance of the PEDOT/PSS graphite electrode formed at a constant voltage of0.9V is optimal.?2?A facile and feasible electrochemical polymerization method has been used to construct the multi-wall carbon nanotubes@poly?3,4-ethylenedioxythiophene?/poly?styrene sulfonate??MWCNTs@PEDOT/PSS?coreeshell composites with three-dimensional?3D?porous nano-network microstructure.The composites are characterized with Fourier transform infrared spectroscopy,scanning electron microscope,and transmission electron microscopy.The electrochemical tests including cyclic voltammetry,galvanostatic charge/discharge measurements,and electrochemical impedance spectroscopy tests are performed,the results manifest the MWCNTs@PEDOT/PSS coreeshell composites have superior capacitive behaviors and excellent cyclic stability,and a high areal capacitance.Furthermore,the MWCNTs@PEDOT/PSS composites exhibit obviously superior capacitive performance than that of PEDOT/PSS and PEDOT/Cl electrodes,indicating the effective composite of MWCNTs and PEDOT noticeably boosts the capacitive performance of PEDOT-based electrodes for electrochemical energy storage.?3?This work reports an approach to significantly improve the supercapacitive properties of poly?3,4-ethylenedioxythiophene?-carbon nanotubes?PEDOT-CNTs?hybrid electrodes.Specifically,a facile electrochemical treatment method is put forward to roughen graphite?G?.After that,the electrochemically treated graphite?EG?acts as the substrate to load the PEDOT-CNTs composites by electrochemical co-deposition.The obtained EG/PEDOT-CNTs electrode shows substantially enhanced electrochemical performances with respect to G/PEDOT-CNTs electrode.Here,the EG/PEDOT-CNTs electrode achieves a high specific capacitance of 278.7 F g^-1at 1 A g^-1.