Preparation Of PEDOT And Study On Electrochemical Performance

Supercapacitors are one of the most important advanced technologies in the long-term development of national energy industry because of its huge market potentiality. Electrode materials are critical for the performance of supercapacitors. Conductive polymers have become a hot spot in the researches of the high performance supercapacitors for the lower cost and high specific capacitance. In this thesis, the study was focused on the synthesis and properties of poly (3,4-ethylenedioxythiophene) (PEDOT), a kind of conductive polymers, to evaluate its potentials and process as an electrode materials of supercapacitors.Firstly, polystyrene sulfonic acid sodium(PSSNa), sodium sulfanilate, p-toluenesulfoni, sulfamic acid and camphorsulfonicacid were selected as the doping agent. Five series of PEDOT materials were prepared with FeCl₃·6H₂O as the oxidant. The doping agents seriously affect the conductivity of PEDOT materials. The conductivity of PEDOT materials prepared with the same conditions decreases with the doping agent in the following order: camphorsulfonicacid, sulfamic acid, p-toluenesulfoni, sodium sulfanilate, PSSNa. The molar ratio of the EDOT monomer to the doping agent and the oxidant, the reaction time and the oxidant feeding way all can affect the conductive properties of PEDOT materials. The highest conductivity was found as 10.4S/cm with the PEDOT/camphorsulfonicacid material prepared with the molar ratio of monomer: doping agent: oxidant ass 2:1:40, the reaction time of 40h, and the oxidant one-time feeding way.Then, the electrochemical performance of PEDOT materials were investigated in detail. Results show that these PEDOT materials have high specific capacitance, good charge-discharge performance and stability and good cycle stability. The doping agents influence the electrochemical properties significantly. The highest electrochemical performance was observed with the PEDOT/camphorsulfonicacid material, while the lowest electrochemical performance was found with the PEDOT/PSSNa materials. The specific capacitance of PEDOT/camphorsulfonicacid electrode materials is determined as 150 F/g after charge-discharge when the molar ratio of monomer: doping agent: oxidant is set as 2:1:40 abd the reaction time is controlled as 41h during the synthesis procedure.