Research on the Early Warning Characteristics of Thermal Runaway in Large Capacity Lithium‐Ion Batteries Based on the Coupling Parameters of Mechanical–Electrical–Thermal
Chaoling Han, Yujiang Qian, Yuanshuai Wei, Zhirong Wang, J. F. Wang
Abstract
The large capacity lithium‐ion batteries (LIBs) are widely applied in energy storage systems, but its thermal runaway issue poses a direct threat to system safety and reliability. The thermal runaway process in high‐capacity batteries is complex, making it difficult to achieve comprehensive monitoring using a single parameter. But fortunately the multiparameter approach enables more accurate thermal risk identification. This study conducted thermal runaway experiments on a 314 Ah single cell triggered by overheating to elucidate the variation patterns of three key characteristic parameters, temperature, voltage, and force. A three‐level thermal runaway early warning method was established based on these findings. The results indicate that under conditions of high heating power and low state of charge (SOC), utilizing force as a threshold enables more effective early warning. Conversely, monitoring temperature variations provides a more timely thermal runaway warning at low heating power and high SOC. Although voltage changes can detect early thermal runaway signs earlier than the other two parameters, they exhibit intermittency and have a narrow warning threshold. Comparatively, thermal runaway warning based on dual‐parameter coupling outperforms single‐parameter approaches. By assessing the time interval between different threshold levels and the onset of thermal runaway, a three‐level warning method can be established. Under different heating power and SOC conditions, temperature coupling with other parameters serves as a primary thermal runaway warning signal, while expansion force coupling with other parameters is more suitable as a secondary or tertiary warning indicator under varying heating power conditions. This research contributes to optimizing safety strategies in high‐capacity battery management systems, providing technical support for the safe development of the new energy industry.