Electrochemical Impedance Spectroscopy: A tool on the electrochemical investigations

Abstract

Since 2000 the number of publications related to Electrochemical Impedance Spectroscopy - EIS has been gradually increasing, going from just over 81 publications in 2000 to over 1800 publications in 2019. In 2020, more than 1028 publications are seen in just 4 months, that is, more than 18,000 publications in the last 20 years. EIS is a very powerful tool in the study of several areas of knowledge, such as chemistry, physics, biology etc. On the other hand, EIS is still considered a difficult technique, due to the mathematical concepts and modeling involved in the analysis of experimental data. Thus, this paper aims to introduce the EIS technique in a more clear and simple way, providing subsidies to all entities involved in scientific research and concisely showing the main points associated with EIS mathematics and physics. Besides, the paper shows how to analyze whether the impedance data obtained is acceptable and how to check its reliability using the Lissajous plots, the Kramers-Kronig transform, and the chi-square test.