Electrochemical characterization of poly-(3,4 propylene-dioxythiophene) pseudo-capacitor

Abstract

Every day use of appliances relies mostly in lithium-ion batteries to satisfy their energy requirements. However, the materials utilized and their lower power densities limit these batteries' desirability. An alternative to batteries is the supercapacitors, which are capable of storing energy in the electrical double layer (EDL) formed between the electrode material and the electrolyte. To reduce the gap in terms on energy and power density between batteries and EDL supercapacitor, pseudocapacitors has been used. In pseudo-capacitors a material that is capable of storing faradaic charge, such as metal oxides and conducting polymers, is deposited in the electrode surface, but its charge / discharge behavior approximate that of the EDL supercapacitor. Therefore, energy density is gained even though the faradaic nature of the process makes its power density decreases. In this paper, we use the conducting polymer, poly-(3,4 propylene-dioxythiophene) for the assembling of a pseudo-capacitor. We present the electrochemical characterization of the devices as a function of the amount of material accumulated in the platinum current collector, in terms of the capacitance, energy, and power density.