Wilson, Marcus TFarrow, VanceDunn, Christopher JCowie, LoganCree, Michael JBjerkan, JulianeStefanovska, AnetaScott, Jonathan B2025-02-122025-02-122025Wilson, M. T., Farrow, V., Dunn, C. J., Cowie, L., Cree, M. J., Bjerkan, J., Stefanovska, A., & Scott, J. B. (2025). Early prediction of Li-ion cell failure from EIS derived from current-voltage time series. JPhys Energy, 7(2). https://doi.org/10.1088/2515-7655/ad97df2515-7655https://hdl.handle.net/10289/17176The ability to reliably detect the forthcoming failure of a rechargeable cell without removing it from its normal operating environment remains a significant goal in battery research. In this work we have cycled in the laboratory a previously-aged 3.2 A h, 3.6 V 18650 INR LiNixMnyCo 1 − x − y O2 cell for 300 d until failure was apparent, using a current waveform representative of use in an electric vehicle application. Electrochemical impedance spectroscopy (EIS) down to 5 µHz was also performed on the cell as a ‘gold-standard’ measure, at the beginning, end and part way through the cycling. Analysis of voltage and current time series data using both parametric (equivalent circuit model) and non-parametric (wavelet-based analysis) approaches allowed us to successfully reconstruct the EIS data. As the battery aged, impedance gradually increased at frequencies between 10−4 Hz—10−1 Hz. The increase accelerated around 50 d before the battery ultimately failed. The acceleration in rate of change of impedance was detectable while the cycle efficiency remained high, indicating that a user of the cell would be unlikely to detect any change in the cell based on its performance or by common measures of state-of-health. The results imply upcoming failure may be detectable from time series analysis weeks before any noticeable drop in cell performance.enThis is an open access article distributed under the terms of the Creative Commons Attribution 4.0 license.http://creativecommons.org/licenses/by/4.0/Journal Article10.1088/2515-7655/ad97df2515-765540 Engineering4016 Materials Engineering4004 Chemical engineering4008 Electrical engineering4017 Mechanical engineering7 Affordable and Clean Energy