Electronically conducting polymers and activated carbon: Electrode materials in supercapacitor technology

The growing interest in supercapacitors is stimulated by their potential application as power-storage devices operating in parallel with the battery in an electric vehicle (EV) to provide pulses of peak power during acceleration and on uphill gradients.“] Many academic and industrial laboratories are currently investigating two types of supercapacitor: the ‘double-layer’ and the ‘redox’. The chargestorage mode is different in each: the capacitance in the former is electrostatic in origin, i.e. it arises from the separation of electron and ionic charges at the interface between high specific-area electrode and an aqueous or an organic electrolyte;[21 in the latter, fast Faradaic chargetransfer takes place at the electrode materials, as in a battery, and produces what is called pseudo~apacitance.