Preparation And Electrochemical Capacitive Characteristic Of Polyaniline-Based Supercapacitor Electrode Materials

Polyaniline (PANI) have attracted considerable attention as supercapacitor electrode material, due to excellent pseudo-capacitive properties, tunable conductivity and environmental stability, easy synthesis, and low cost. In particular, PANI nanofibers attract more and more interest because of their more active surface area and higher porosity, which can form 3D conductive network and then reduce the electrode resistance. On the other hand, polyaniline/carbon composites have also aroused the concern of the researchers because the composites not only achieve high specific capacitance but also keep excellent cycle stability. However, the morphology control and uniform dispersion of PANI nanostructure have always been the challenge for developing the poyaniline@carbon composites. This paper focuses on the controllable preparation of PANI nanofibers and their composing with different carbon substrate for the development of high capacitive supercapacitor electrode materials.(1) The chemical oxidation polymerization was used to prepare PANI nanofibers. The PANI prepared in 1 mol L-1 H3PO4 system showed the morphology of well-ordered nanofibers and the best capacitance, which showed a high specific capacity of 481.2Fg-1at 0.5A g-1.(2) Two different composites of PANI @ CNFs and PANI @ NPCNFs were prepared and their structure and electrochemical performance were studied. The study determined that phosphorus oxygen functional group on the surface of NPCNFs can induce the arrangement of PANI molecules, forming ordered "V- type" channels. The PANI@NPCNFs exhibited a smaller impedance and a higher specific capacitance than PANI@CNFs.. Compared with pure PANI, although the PANI@NPCNFs showed a lower initial capacitance, the rate performance is better, with a capacitance retention of 79% from 0.5A g-1 to 20A g-1.(3) The concentration of aniline monomer affected the morphology of PANI layer and electrochemical properties of PANI@NPCNFs1 composites. When the aniline monomer content is 15mmol, the prepared composites PANI@NPCNFs-15 showed the best electrochemical performance, with the specific capacitance up to 436.8 g F-1 at o.5A g-1 and the only 4% decrement in specific capacitance after 1000 cycles at 10A g-1.