Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7832191 | Acta Physico-Chimica Sinica | 2007 | 6 Pages |
Abstract
Conducting polypyrrole (PPy) films doped with p-toluenesulfonate (TOSâ), ClO4â, and Clâ were electrochemically prepared, respectively. The electrochemical capacitance properties of the PPy films were investigated with cyclic voltammetry (CV), galvanostatical charge/discharge, and electrochemical impedance spectroscope (EIS) techniques. The morphology observation and structure analysis of PPy films were performed by scanning electron microscope (SEM) and X-ray diffraction (XRD). The results showed that PPy-Cl and PPy-TOS were characterized with a highly porous and ordered structure, which led to their fast ion switch processes. Moreover, they exhibited a rectangle-like shape of voltammetry characteristics even at a scanning rate of 50 mV·sâ1, a linear variation of the voltage with respect to time in the charge/discharge process, and almost ideal capacitance behavior in low frequency, even in deeply charged/discharged states in 1 mol·Lâ1 KCl solution. Furthermore, specific capacitance of PPy-Cl (polymerization charge of 2 mAh·cmâ2) could reach 270 F·gâ1 (scanning rate of 5 mV·sâ1) or 175 F·gâ1 (scanning rate of 200 mV·sâ1) and its specific energy could reach 35.3 mWh·gâ1. Moreover, with heavier doping ion (TOSâ), PPy-TOS (polymerization charge of 2 mAh·cmâ2) had a slightly smaller specific capacitance (146 F·gâ1, scanning rate of 5 mV·sâ1), but a very rapidly charge/discharge ability (specific capacitance of 123.6 F·gâ1 at scanning rate of 200 mV·sâ1) and its specific power could reach 10 W·gâ1. In addition, both PPy-TOS and PPy-Cl had good cycleability. All of the above implied that the PPy-Cl and PPy-TOS were two kinds of promising electrode material for supercapacitors.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Jie Wang, Youlong Xu, Xi Chen, Xianfeng Du, Xifei Li,