Binder-free porous PEDOT electrodes for flexible supercapacitors

Conducting polymers are attractive for potential applications in flexible electronic industries because of their unique advantages. To simplify the process of electrode preparation, porous poly(3,4-ethylenedioxythiophene) (PEDOT) film electrodes without binder and conductive additive were synthesized facilely for flexible supercapacitors via an in situ solution micro polymerization at the surface of a soft etched tunnel aluminum (ETA) template at room temperature. The template was directly used as the current collector of electrodes. The morphologies of the samples and the template were compared using scanning electron microscopy (SEM), and the polymer molecular structure and composition were analyzed with Fourier-transform infrared (FTIR) spectroscopy. Symmetric supercapacitors were assembled with the PEDOT electrodes, Celgard 2300 separator, and 1.0 M LiPF6/EC+DMC+EMC (1 : 1 : 1 in volume) electrolyte. The electrochemical performance was evaluated using different techniques like galvanostatic charging/discharging tests, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The results from different current densities and scanning rates show the supercapacitors have good rate performance. The specific capacitance, energy density, and coulombic efficiency of the PEDOT supercapacitor can reach 69.0 F g(-1) (or 103.0 F m(-2)), 24.0 Wh kg(-1), and similar to 95% at a current density of 0.2 A g(-1), respectively. Furthermore, the PEDOT electrodes exhibit relatively good cycle performance, and the capacitance retention ratio is similar to 72% after 1500 cycles. The electrode process was discussed. The results are comparable to that of the reported PEDOT, which indicates the applicability of the novel simple method of solution microreaction at the surface of a soft metal template to directly prepare binder-free flexible electrodes. (C) 2015 Wiley Periodicals, Inc.