Impedance Spectroscopy for Electroceramics and Electrochemical System

This tutorial review focuses on the basic theoretical backgrounds, their working principles, and the implementation of impedance spectroscopy in both electroceramics and electrochemical research and technological applications. Various contributions to the impedance, admittance, dielectric, and conductivity characteristics of electroceramics materials can be disentangled and independently characterized with the help of impedance spectroscopy as a function of frequency and temperature. In polycrystalline materials, the impedance, charge transport/conduction mechanism, and the macroscopic dielectric properties, i.e., dielectric constant and loss are typically composed of many contributions, including the bulk or grain resistance/capacitance, grain boundary, and sample-electrode interface effect. Similarly, electrochemical impedance spectroscopy (EIS) endeavors to the charging kinetics, diffusion, and mechanical impact of various electrochemical systems widely used in energy storage (i.e., supercapacitor, battery), corrosion resistance, chemical and bio-sensing, diagnostics, etc., in electrolytes as a function of frequency. The understanding of various contributions in the EIS spectra, i.e., kinetic control, mass control, and diffusion control is essential for their practical implications. It is demonstrated that electrochemical and electroceramics impedance spectroscopy is an effective method to explain and simulate such behavior. Deconvolution these contributions obtains a detailed understanding of the functionality of polycrystalline electroceramic materials. This short review aims to provide the necessary background information for junior researchers working in these fields and allows readers to quickly comprehend the fundamental understanding in this field by saving their time and understanding, and applying impedance spectroscopy in their future projects.