Synthesis Of Polypyrrole-based Electrochemical Energy Storage Materials And Their Applications

As a kind of important conductive polymers, polypyrrole (PPy) has specialmolecular structure and excellent physical and chemical properties. However,PPy also has the same defects of with other conducting polymers in practicalapplication, including bad stability and mechanical performance. In this thesis,we try to preparing3DOM PPy and its composites, which are applied to thebattery and supercapacitor. Finally, we try to using cyclodextrin (CD) modifiedgraphene oxide (GO), for the further preparation of PPy/GO composites.(1) The synthesis of polypyrrole inverse opal: Most primary cells use Zn orLi as the anode, a metallic oxide as the cathode, and an acidic or alkalinesolution or moist past as the electrolytic solution. In this paper, highly-orderedpolypyrrole (PPy) inverse opals have been successfully synthesized in theacetonitrile solution containing [bmim]PF6. PPy films were prepared under thesame experimental conditions. Cyclic voltammograms of the PPy film and thePPy inverse opal in neutral phosphate buffer solution (PBS) were recorded.X-ray photoelectron spectroscopy technique was used to investigate the surfacestructural the PPy films and the PPy inverse opals. It is found that the PF6-anions kept dedoping from the PPy films during the potential scanning process,resulting in the electrochemical inactivity. Although PF6-anions also keptdedoping from the PPy inverse opals, the PO43-anions from PBS could dopeinto the inverse opal, explaining the reason why the PPy inverse opals kept theirelectrochemical activity. An environmental friendly cell prototype wasconstructed, using the PPy inverse opal as the anode. The electrolytes in both thecathodic and anodic half-cells were neutral PBS. The open-circuit potential ofthe cell prototype reached0.487V and showed stable output over severalhundred hours. (2) Three-dimensional ordered macroporous (3DOM) carbon nanotube(CNT)/PPy composite electrodes for supercapacitor application were preparedthrough cyclic voltammetric co-polymerization from a solution containing bothacid treated CNTs and pyrrole monomers. A self-assembled SiO2colloidalcrystal was used as the sacrificial template. After electrochemicalco-polymerization, the template was removed, and a3DOM CNT/PPycomposite electrode was obtained. The3DOM CNT/PPy composite filmsshowed great performance as an electrode material for supercapacitors. Thespecific capacitance of the3DOM CNT/PPy composite reached427F/g at thescanning rate of5mV/s.(3) The synthesis of GO/CD composites: We use CD modify the GO, andmake the preliminary characterization.