Anomaly detection of LiFePO4 pouch batteries expansion force under preload force

Overcharging, overheating and other abnormal conditions are important causes of thermal runaway of Li-ion batteries, and a major safety issue for Li-ion batteries. Therefore, it is critical to detect these faults as soon as they are triggered. In this paper, the actual usage scenario of the battery was simulated by setting the appropriate preloading force. And the characteristics of the changes of the battery expansion force under abnormal conditions were studied by battery charging and discharging, overcharging, overdischarging and thermal runaway experiments. In particular, we proposed a fast and high confidence battery fault detection method by the characteristics of the expansion force change under various faults, which could provide early warning of multiple faults. This work provided a reliable method of detecting battery failures at an early stage and ensured process safety and reduced environmental pollution caused by lithium-ion battery accidents through reasonable fire prevention measures.