Preparation And Application Of PEDOT@Nanoporous Gold Composite For Supercapacitors

With the rapid development of science and technology and economy,flexible and high electrochemical performance energy storage devices have become a research hotspot in recent years.Among them,supercapacitors have great market potential in the energy field due to their advantages of high power density,fast charge and discharge speed,wide operating temperature limit,and environmental protection.For supercapacitors,electrode materials are the decisive factor affecting their performance.Among them,conductive polymers have the advantages of low cost and simple synthesis,and are hot research topics of electrode materials.Among the conductive polymers,poly?3,4-ethylenedioxythiophene??PEDOT?has a simple molecular structure,easy synthesis,and small energy gap,and is widely used in the field of energy storage.However,due to its lower specific capacity and conductivity,its application in supercapacitors is limited.Therefore,it is necessary to find a suitable substrate to polymerize 3,4-ethylenedioxythiophene?EDOT?to increase its conductivity.Nanoporous gold?NPG?has excellent electrical conductivity,high specific surface area and unique continuous pore structure,which is an excellent choice for substrate materials.In this paper,the electrochemical synthesis method is used,and NPG is used as the substrate and current collector to polymerize EDOT.The obtained PEDOT grows along the NPG skeleton and is uniformly coated on the NPG skeleton to form the core-shell structure of the conductive polymer-coated metal skeleton.The obtained composite electrode material has a high specific capacitance,the supercapacitors prepared using composite electrodes also have good electrochemical properties.Main works as follows:?1?The monomeric EDOT was polymerized onto the skeleton of NPGby electrochemical polymerization.The PEDOT@NPG composite electrode material with different conductive polymer deposition amount was obtained by controlling the polymerization time.The effect of PEDOT deposition on the structure and electrochemical properties of composite electrode materials was investigated.Scanning electron microscopy?SEM?and high resolution transmission electron microscopy?HRTEM?were used to observe the surface morphology of the composite.The results show that PEDOT is uniformly coated on the NPG to form the core-shell structure,and the three-dimensional pores of the NPG are well preserved.The electrochemical performance of the PEDOT@NPG composite electrode material was tested by electrochemical workstation.The results show that the specific capacitance of PEDOT@NPG composite electrode can reach 555 F/g when the current density is 3 A/g.The energy density is 177.58 W h/kg and the power density is 1.73 kW/kg.The cyclic stability test is carried out by cyclic voltammetry.The results show that the PEDOT@NPG composite electrode can maintain 84.3%of its maximum capacitance after 2000 cycles at a sweep speed of 100 mV/s.?2?Electrochemical pseudocapacitor was prepared by using thePEDOT@NPG composite electrode as the two poles of the supercapacitor.The results of SEM and TEM showed that the PEDOT were uniformly coated on the skeleton of NPG to form a core-shell structure.The electrochemical performance test results show that the PEDOT@NPG//PEDOT@NPG symmetric supercapacitor has the specific capacitance of 169.32 F/g,and the energy density and power density of the symmetric supercapacitor reaches 52.65W h/kg and 0.6 kW/kg.It can maintain 80.6%of its maximum capacitance after2000 cycles at a sweep speed of 100 mV/s..?3?Asymmetric supercapacitor was prepared by using PEDOT@NPGcomposite electrode as negative electrode and MnO₂@NPG composite electrode as positive electrode.The results of SEM and TEM showed that both active substances were uniformly coated on the skeleton of NPG to form a core-shell structure.The electrochemical performance test results show that the voltage window of PEDOT@NPG//MnO2@NPG asymmetric supercapacitor can reach1.5 V in aqueous electrolyte,and the specific capacitance can reach up to 232.33F/g.Due to its wide voltage window,asymmetric supercapacitors have an energy density and power density of 131.44 W h/kg and 3.37 kW/kg,which can maintain 80.73%of its maximum capacitance after 1600 cycles at a sweep speed of 100 mV/s.