Electrochemical impedance spectroscopy (EIS) is a powerful technique that utilizes a small
amplitude, alternating current (AC) signal to probe the impedance characteristics of a cell.
The AC signal is scanned over a wide range of frequencies to generate an impedance
spectrum for the electrochemical cell under test. EIS differs from direct current (DC)
techniques in that it allows the study of capacitive, inductive, and diffusion processes taking
place in the electrochemical cell. The theory behind EIS is more complex than DC techniques,
so it’s advised to have a basic understanding of the underlying principles before beginning.
EIS has far reaching applications including coatings, batteries, fuel cells, photovoltaics,
sensors, and biochemistry. This guide will focus on the application of the EIS technique for
analyzing the corrosion performance of coated aluminum panel.
Knowledge of the electrochemical system being investigated is also useful before beginning.
With a basic understanding of the system it can be known if the potentiostat will be able to
gather the desired information, and if the data collected meets accuracy requirements.