Effect of Triton X-100 on the double layer capacitance and conductivity of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films

Among conducting polymers, PEDOT:PSS is a promising electrode material for supercapacitors, due to stability and simple processability of the polymer. However, a thin film of spin coated PEDOT:PSS shows a compact structure with relatively low double layer capacitance. In order to enhance the film porosity, a surfactant (Triton X-100) has been added to the polymer solution before spin coating. In this work, the effect of concentration of Triton X-100 on the double layer capacitance and conductivity of the PEDOT:PSS film has been studied. Different electrodes were fabricated with PEDOT:PSS samples that were prepared with different levels of Triton X-100. A peak specific double layer capacitance of 20 F/g was achieved in the electrode with 3.0 wt% of Triton X-100 which was ∼10 times larger than the capacitance in the electrodes with 0.0 and 5.0 wt% surfactant. Additionally, the conductivity of the PEDOT:PSS films were enhanced with application of Triton X-100 by at least 20 times. The SEM (scanning electron microscopy) images of the electrodes show correlation that the increase in capacitance with 3.0 wt% surfactant was due to the augmentation of porosity of the films structure.