University of Windsor

Published purpose

Electric vehicle adoption and battery second-life applications require efficient tools for battery degradation monitoring and state-of-health estimation. Electrochemical Impedance Spectroscopy (EIS) is widely used for this purpose; however, University of Windsor research has identified a critical limitation in conventional measurements: opencircuit-voltage (OCV) induced bias can distort impedance estimates, particularly at low frequencies. The Project will advance a corrected EIS excitation and analysis method that combines a tailored excitation waveform with an observation model to estimate and remove the OCV contribution from the measured response. Initial proof-of-concept experiments have demonstrated feasibility at TRL 3. The Project will advance the technology to TRL 4 through systematic laboratory validation, benchmarking against conventional EIS, and evaluation across different cells, chemistries, states of charge, and measurement conditions. The NRC will conduct parallel validation and contribute to documenting the methodology and results.