The Study Of Conducting Polypyrrole And Its Composites Applied As Electrode Material Of Supercapacitor

In this paper, one of the typical conducting polymers, polypyrrole (PPy), and its composites had been studied as electrode materials of supercapacitor. The research included the preparation of PPy/CNTs composites and PPy with different structure, the influence of surfactant on the morphology and electrochemical properties of prepared materials as well as the effect of morphology of PPy on specific capacitor. Through a series of eletrochemcial tests containing Transmission Electron Microscope (TEM), Infrared Spectrum (IR), Scanning Electron Microscope (SEM) , Cyclic Voltammetry (CV), galvanostatic charge/discharge characteristic and Electrochemical Impedance Spectroscopy (EIS) and four probes method for charactering conductivity, the electrochemical characters, especially the specific capacitor, had been studied and discussed in this paper. The research study and work mainly referred to three aspects as following:Firstly, composites consisting of the CNTs with PPy covered by sheets of PPy had been prepared via adding one kind of surfactant, Sodium dodecyl Benzene Sulfonate (SDBS). Electrostatic adoption effect of SDBS was emphasisd on during this study. it indicated that SDBS could effectively improve the interconnection of CNTs and PPy during the process of polymerization; the electrochemical property of prepared material was greatly enhanced due to synergetic effect between PPy and CNTs. The electrochemical capacitance of the obtained porous PPy/CNTs composite was about 101.1 F/g with organic electrolyte, which was much more higher than the value of pristine PPy (about 19 F/g).And then, a simple, practical and controllable chemical polymerization, interfacial synthesis, was developed for preparation of PPy film applied as electrode material. Through chemical oxidation, PPy film formed at the interface of water/chloroform without any matrix and stirring. Small nanoparticals(30～90nm) of PPy were demonstrated through Infrared Spectrum (IR) and SEM. The film of PPy presented excellent electrochemical character in the measurement of CV, galvanostatic charge/discharge characteristic, EIS as well as four probes method for charactering conductivity. The specific capacitance was 88.1 F/g (organic electrolyte) which had little decrease after 200 times of cycles and electrochemical charge transfer resistance was 40Ω. Moreover, the conductivity of PPy film was tested by four probes method and achieved to 19 S/cm (293K). It resulted that interfacial synthesis was a novel kind of convenient and promising method to prepared PPy films that were used as electrode materials in ESC.Besides, PPy tubular which achieved via introducing the soft model was also researched in this paper. Moreover, the model was formed by the complex of Methyl Orange (MO) and ferric chloride. Amounts of special porous were structured by the PPy tubular arraying without order. This special construction could be helpful for the ions to transfer during change/discharge process as well as improve the electrochemical performance of PPy. The PPy tubulars with specific capacitor at 58.0 F/g were achieved in this experiment. However, as the advance was not extremely obvious, some method should be considered to enhance the capacitor, such as arranging the tubular PPy in certain direction.