Study of lithium-ion battery module external short circuit risk and protection design

This study is the first to investigate the risk factors and protection design of battery modules with varying voltage levels in the context of external short circuit (ESC) faults. Three types of module ESC tests are carried out, including ESC without protection, ESC with weak links protection, and ESC with fuse protection. By analyzing the electrical, thermal, and gas signals during the experiments, two main risk modes were identified: thermal runaway gas production induced ignition and arc restrike breakdown. The breaking time and arc extinguishing capacity of the protective device are crucial for ensuring the safety of the battery module in the event of ESC. The applicability of weak links and the necessity of the arc extinguishing capability of the protective device are demonstrated experimentally and analytically. Furthermore, we incorporated side reaction heat sources into the electrochemical thermal coupling model to conduct a quantitative analysis of the relationship between the protective device's response time and short-circuit resistance conditions. These findings offer valuable insights for the design of protective measures in battery modules subjected to ESC faults.