Carbon Nanotube and Polypyrrole Supercapacitors: Capacitance, Energy and Power

Electrochemical capacitors also called supercapacitors are electrical energy storage devices filling the performance gap of conventional capacitors and batteries. They can store energy electrostatically at the electrode/electrolyte interface (double layer capacitance) and/or via Faradaic charge storage through reversible successive redox processes (pseudocapacitance). As such they achieve higher energy densities compared to dielectric capacitors while delivering significantly higher power than batteries. The amount of ion accessible surface area of the electrode material and the amount of time required for electronic charges and ionic charges to reach the electrode/electrolyte interface are the performance determining factors. Here the performance of carbon nanotubes and polypyrrole as electrode materials along with various organic electrolytes are explored.