Work

Impedance-based Thermal Runaway early detection methodology for Lithium-Ion batteries

Year: 2025

Type: article

Abstract: In this work, a new impedance-based Thermal Runaway (TR) early detection methodology for Li-ion batteries is proposed. By using Electrochemical Impedance Spectroscopy (EIS), the impedance of a battery has been tracked during a full TR event. The potential of EIS and cell impedance tracking for detecting a TR event in an early stage is demonstrated, thus improving battery safety and State-of-Safety estimation. The impedance module and phase trends are studied based on single-frequency impedance measurements to detect the event. To develop the impedance-based detection strategy, Accelerating Rate Calorimetry tests are carried out to characterize cell impedance behavior at different temperatures and different State-of-Charge values. This characterization is used to select the most adequate frequency range for detecting a TR event. Then, this methodology is validated by fast-paced (under 20 min) over temperature abuse tests, demonstrating that this methodology is valid for both rapid and slow-paced TR events. In addition to this, the performance of this methodology is compared to gas sensing based TR detection, using current State-of-the-Art automotive grade gas sensors for this purpose. The results show that the impedance-based method detects the TR 15 h before the explosion in a slow-paced event. The impedance-based method also outperforms the gas sensing based detection at fast-paced events, complying with regulations such as R100 Rev3 requirements of a 5-minute warning.

Source: International Journal of Electrical Power & Energy Systems

DOI: 10.1016/j.ijepes.2025.111053