Capacitance characteristic of PEDOT electrodeposited on different substrates

poly(3,4-ethylenedioxythiophene) (pedot) has been electrochemically deposited on carbon paper (cp), stainless steel mesh (ssm), stainless steel (ss), and indium tin oxide (ito) by unipolar-pulsed method. the surface morphology, micro-structure, and electrochemical capacitance for pedot/substrates were characterized by scanning electron microscope (sem), fourier transform infrared spectroscopy (ftir), and electrochemical techniques. the electrochemical capacity measurements of the pedot/cp electrode in 0.5 m h2so4 shows high mass-specific capacitance of 126.24 f/g at a 1 ma/cm2, which is consistent with the specific capacitance of 126.75 f/g at 5 mv/s. compared with pedot/ssm, pedot/ss, and pedot/ito, pedot/cp electrode shows better capacitive performance, which presents good rate performance of 76.78% at 5 ma/cm2 and charge-discharge stability with the capacitance retention rate of 80.57% for 5000 cycles. sem result shows pedot maintained the spindle-like structure along with the threads of each carbon fiber, which are densely packed and randomly oriented forming the porous structure.