Overcoming EIS Challenges to Advance Battery Designs for Evolving EV and ESS Applications

This white paper examines the evolving design of lithium-ion batteries, driven by the growth of electric vehicles (EVs) and energy storage systems (ESSs). It highlights the challenges of accurately measuring internal resistance due to low resistance levels and complex cell designs. The paper focuses on the role of Electrochemical Impedance Spectroscopy (EIS) in assessing battery performance, particularly resistance and reactance components. It discusses how changes in electrode terminal design affect measurement accuracy, with experimental results showing the impact of inductive magnetic fields and eddy currents. The findings emphasize the need for optimized EIS techniques to accurately characterize next-generation battery technologies.