Electrochemical Impedance Spectroscopy‐Based Dynamic Modeling of Lithium‐Ion Batteries Using a Simple Equivalent Circuit Model

Abstract

As one of the most commonly used models for describing the dynamic voltage response of lithium‐ion batteries (LIBs), the equivalent circuit model (ECM) is routinely parameterized using the time–domain experimental data from some dynamic tests. One downside of this time–domain approach is a lack of credible physical interpretation about the model parameters. In this article, a genuine electrochemical impedance spectroscopy (EIS)‐based dynamic modeling approach for LIBs is developed, which only uses low‐frequency EIS data in parameterization of the ECM. The EIS‐based modeling method combines simplicity, high accuracy, and clear physical interpretation. With the EIS‐based modeling method, a simple ECM, namely, a serial connection of a resistance (), describing Ohmic polarization and interfacial reactions, and an resistance–capacitance parallel branch (), describing diffusion polarization, suffice to accurately capture LIB dynamics in most applications.