Introduction to Electrochemical Impedance Spectroscopy

Understanding how energy storage and conversion systems behave under load is critical for modern chemical and electrochemical engineering. Electrochemical Impedance Spectroscopy (EIS) is a powerful diagnostic tool used to probe the internal physical and chemical processes of batteries, fuel cells, and corrosion systems. This text-based course guides you through the foundational physics, mathematical models, and practical interpretation of impedance data. By completing this course, you will transition from a beginner to a practitioner capable of reading complex Nyquist and Bode plots, selecting appropriate equivalent circuit models, and extracting meaningful physical parameters from experimental data. What you'll learn: - Understand the core physical and electrochemical principles of impedance spectroscopy - Interpret Nyquist and Bode plots to identify dominant system resistances and capacitances - Construct equivalent circuit models using resistors, capacitors, and constant phase elements - Analyze diffusion processes using Warburg impedance formulations - Apply EIS concepts to evaluate battery health and fuel cell performance degradation - Learn modern data validation techniques, including Kramers-Kronig relations This course begins with essential electrochemical definitions, foundational AC circuit theory, and the core mathematical framework of complex impedance. You will then progress through detailed written analyses of electrode kinetics, mass transport limitations, and hands-on equivalent circuit fitting strategies. This course is designed for chemistry students, chemical engineers, energy analysts, and materials science professionals who are new to electrochemical impedance analysis. No prior advanced knowledge of spectroscopy is required, though a basic understanding of general chemistry and algebra is recommended. Start reading today to master the fundamentals of electrochemical impedance analysis.