The Study Of Supercapacitor Electrodes Using Conductive Polyaniline And PANI Composite Materials

This dissertation studies polyaniline and C-PANI composite materials preparation processes, structural performances and applications in super-capacitors as the electrodes. Ttransmission electron microscope (TEM), scan electron microscope (SEM), Fourier Transform Infrared Spectroscopy have been used to characterize the materials, and their electrochemical performances have been studied by the cyclic voltammogram curves, galvanostatic charge-discharge curves.Chemical polymerization method was used to prepare carbon fibre-polyaniline (PANI/C1) and activated carbon fibre-polyaniline (PANI/C2) composite by coating polyaniline on the surface of the carbon fibre. The SEM results indicated that the surface area of activated carbon fibre increased. The activated carbon fibre -polyaniline composite is more symmetrical. PANI/C1 and PANI/C2 were used as electorde materials of electrochemical capacitor. The results showed that the capacitances were 35.0F/g and 62.6F/g respectively in organic electrolyte.Electorde materials of polyaniline were prepared by interfacial polymerization. And (NH₄)₂S₂O₈ used as the oxidant, doping agents were selected hydrochloric acid, nitric acid, sulphuric acid, Perchoric acid, phosphoric acid. The cyclic voltammogram curves showed that the polyaniline which phosphoric acid as doping agents had good reversibility and the high response current. The galvanostatic charge-discharge curves showed that the capacitances were 24.6F/g,19.5 F/g,39.1 F/g,49.2 F/g and 61.5F/g respectively in organic electrolyte. So phosphoric acid as the doping agent, the PANI prepared by interfacial polymerization is more suitable for the electrode materials. The SEM results indicated that the material is mainly constituted with a lot of the approximate ellipsoid polyaniline nanoparticles and short and thick polyaniline fiber.Finite field polymerization was applied to prepare carbon nanotubes -polyaniline (CNTs-PANI) composite based on coating polyaniline on the surface of the CNTs. The results showed that PANI could symmetrically grow on the surface of the CNTs by the finite field method. The specific capacitance of the obtained composite material was about 117.7 F/g (organic electrolyte) though the specific capacitances of the pure CNTs and the pure PANI were about 25.0 F/g and 61.5 F/g at the same conditions. All these indicated that the finite field polymerization is a promising method to prepare nano-composite.