Electrochemical Impedance Spectroscopy Part 1: Fundamentals

Electrochemical impedance spectroscopy (EIS) enables the examination of electrochemical nature electrodes and cells by applying an alternating voltage (or current) measuring resulting current voltage). The resistance capacitance components electrode can be evaluated AC changing frequency. In particular, analysis using equivalent circuit determine important parameters related to reaction electrode, such as charge transfer resistance, electric double-layer capacitance, Warburg impedance. Moreover, internal cell divided into resistances caused positive negative electrolyte. Because these advantages, EIS is a powerful technique used for basic research, in identifying rate-determining step reaction, also applied characterizing devices (e.g., batteries capacitors). this paper, concept impedance, which represents relationship between current, first explained; then, characteristics various elements circuits, are essential understanding EIS, described. Finally, treatments more complex circuits based on transmission-line models (TLMs), represent porous electrodes, presented. Analyses TLMs foundation practical applications because usually devices.