Preparation And Electrochemical Properties Of Polyaniline / Porous Carbon Composite Materials

As the electrode material of supercapacitor, porous carbon has high electric conductivity and cyclic stability. But the specific capacity is much lower than that of metal oxides and conductive polymers. Polyanilin electrode shows higher specific capacitance, but the cyclic property is worse. By combining PAn and porous carbon, a new kind of composite electrode material with higher conductivity and specific capacitance as well as better stability will be obtained. The capacitance consists of double layer capacitance and redox capacitance.In this experiment, PAn-porous carbon composites were prepared via the in-situ solution polymerization of aniline on carbon materials. Three kinds of porous carbons, i.e., active carbon (AC), carbon aerogels (Ag) and ordered mesoporous carbon (OMC) were chosen as the crbon matrix. The morphologies and structures of these materials were characterized by XRD, FE-SEM, TEM, HRTEM and FT-IR measurements. The relationship among synthesis methods, structures of the derived materials and the electrochemical performances were founded. CV, device of electrical resistivity and constant current charge/discharge were used to study the electrode materials' electrochemical properties.For PAn/AC composite material, the results indicated: The stability and reversibility of the electrode materials are better. The capacitances consist of double layer capacitance and redox capacitance. When the active carbon content is 20% the composite's conductivity attained the highest value of 5．88×10S/cm. The material's specific capacitance is as high as 400F/g. For PAn/OMC composite material, the electrode composites' capacitances consist of double layer capacitance and redox capacitance. When the mass ratio of OMC to aniline was 30:70, the PAn/OMC composite prepared by in-situ polymerization method exhibited highest special capacitance of 895 F/g. When their mass ratio was increased to 50:50, the outstanding high rate capability was obtained. For PAn/Ag composite material, When the active carbon content is 20% the composite's specific capacitance is up to 658 F/g, which is far higher than those of PAn/AC and PAn/OMC with the same ratio. And it is worthy to be studied further.