Obvious enhancement in electrochemical capacitive properties for poly(3,4-ethylenedioxythiophene) electrodes prepared under optimized conditions

This work investigates the effect of preparation conditions on the supercapacitive performances of the poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes electrodeposited detailedly. These preparation conditions include electrode substrates, electrodeposition modes, parameters, and counter anions. Electrochemical characterizations indicate an evident impact of electrode substrates on the electrochemical behaviors of the PEDOT electrodes prepared. Graphite foils (GF) as the electrode substrate show better electrochemical capacitive properties relative to conductive glasses (CG). This can be ascribed to lower sheet resistance and better adhesion to the PEDOT films for the former. Moreover, SEM and AFM tests indicate that different electrodeposition modes, parameters, and counter anions would result in different morphologies and roughness for the PEDOT electrodes obtained, consequently affecting their supercapacitive performances. Among numerous preparation conditions, the polystyrene sulfonic acid salt-doped PEDOT deposited on GF substrates prepared with potentiostatic mode at 0.9 V shows the best supercapacitive behaviors, delivering the specific capacitance of 108.2 mF cm −2 at 0.2 mA cm −2 , also exhibiting good rate capability and superior cycle performance (keeping 93.4% of initial capacitance after 10,000 cycles). This work indicates that the supercapacitive properties of PEDOT electrodes can be substantially enhanced by changing their preparation conditions.