초록 |
Over the last few decades, polyaniline (PANI) has found a wide range of applications due to its electrical properties, reversible redox behaviors and environmental stability. Here, we first present a simple way of preparing PANI nanostructures with three different aspect ratios, namely, nanospheres, nanorods, and nanofibers, for which a water-soluble polymer, polyvinyl alcohol was employed in aqueous solution. Then, we examine key factors determining the device performance when PANI nanostructures are used as the electrode-active materials for electrochemical capacitors. The polymerization rate became slower in the presence of the stabilizer yielding PANI nanostructures with lower aspect ratios. Accordingly, it is believed that the stabilizer sterically restricts the directional fiber growth mechanism governing PANI chain growth in aqueous solution. Briefly, the nanofiber electrode had faster electrode kinetics and better capacitance than the nanorods and nanospheres. It also turned out that the interparticle contact resistance highly influenced the capacitances of the electrodes. |