Introduction Electrochemical Impedance Spectroscopy (EIS) is an electrochemical technique with applications in corrosion, biosensors, battery development, fuel cell development, paint characterization, sensor development, and physical electrochemistry. EIS can even be used to test the freshness of fish! (J. Food Science, 65, 780 (2000)) The reason for this popularity is the high information content of EIS. EIS provides a more thorough understanding of an electrochemical system than any other electrochemical technique. Why is EIS so powerful? Because the EIS experiment involves the application of a sinusoidal electrochemical pertubation (potential or current) to the sample that covers a wide range of frequencies. This multi-frequency excitation allows (1) the measurement of several electrochemical reactions that take place at different rates and (2) the measurement of the capacitance of the electrode. For an excellent introduction to EIS, see our Basics of EIS Application Note. The Reference Section at the end of the EIS Application Note contains additional material that will be useful to you. If you have any questions on EIS, you'll find that your friends at Gamry are a wealth of information. Call our support team if you'd like discuss the theory or the applications of EIS. |