Flexible and high surface area composites of carbon fiber, polypyrrole, and poly(DMcT) for supercapacitor electrodes

Thin films of polypyrrole (Ppy) and poly-2,5-dimercapto-1,3,4-thiadiazole (poly(DMcT)) are electrochemically deposited on pieces of carbon fiber (CF) cloth, yielding flexible and high surface area composites that are characterized as electrodes for supercapacitors. A bilayered polymeric composite (CF/poly(DMcT)/Ppy) is obtained by depositing a nanometric layer of Ppy on CF already supporting a poly(DMcT) film. Electrochemical stability tests indicate that the Ppy film acts as a barrier that prevents the loss of the poly(DMcT) electroactive material, thus improving the charge-storage characteristics of the bilayered film even after 1000 cycles. Specific capacitance values of 460 +/- 50 and 1130 +/- 100 Fg(-1) are observed for electrodes made of the CF/Ppy and CF/poly(DMcT)/Ppy composites, respectively. Comparatively to similar Ppy composite materials used for supercapacitors, the bilayered film electrode here reported presents a significantly improved specific capacitance value. (C) 2013 Elsevier Ltd. All rights reserved.