Modeling electrochemical double layer capacitor, from classical to fractional impedance

The application of the fractional calculus for modeling electrochemical double layer capacitors is a novel way to get simpler and precise models. This paper provides a summarized report of several models of Electrochemical Double Layer Capacitors (EDLC). From classical models based on simple structures composed by networks of passive elements (RLC), to models which involve the fractional behavior of EDLC. The fractional models are based on one hand by a function with fractional poles and zeros and for other one by electrochemical elements (Warburg, Bounded Warburg, Havriliak-Negami). On using the impedance spectroscopy method, experimental results for different EDLCs have been obtained. Coming to the conclusion that the fractional models are fitted better than the classical models.