Investigating the Thermal Runaway Behavior and Early Warning Characteristics of Lithium-Ion Batteries by Simulation

The extensive utilization of lithium-ion batteries in large-scale energy storage has led to increased attention to thermal safety concerns. The conventional monitoring methods of thermal runaway in batteries exhibit hysteresis and singleness, posing challenges to the accurate and quantitative assessment of the health and safety status of energy storage systems. Assessing the safety status and thermal runaway warning threshold of lithium-ion batteries typically necessitates the collection of a substantial amount of battery operation and thermal runaway test data. The simulation offers an efficacious and convenient solution for establishing the safety status database of lithium-ion batteries. A multi-physical-field coupling simulation model incorporating electrochemical, thermal, and mechanical processes is employed to simulate the changes in the characteristic parameters throughout the battery thermal runaway process under different conditions. The thermal safety state of the cell is analyzed by calculating the characteristic values including voltage, temperature, and deformation. The simulation results demonstrate that the deformation will reach its warning value in advance of other characteristics, thereby enabling the early detection of thermal runaway. In the case of electrical abuse, the voltage is more susceptible than temperature and deformation. The coupling simulation and safety state calculation method based on characteristic parameters enable the quantification of the safety state of the cell and even the module. The thermal safety threshold of lithium-ion batteries is analyzed, and the security status of the energy storage system can be predicted by deep learning, thereby facilitating the further application of artificial intelligence in the field of energy storage security.