Simulation and analysis of lithium-ion batteries thermal runaway during overcharge

To solve the problem of temperature distribution and voltage variation of lithium-ion batteries under overcharge conditions, an electro-thermal coupling model considering side reactions was established, and the overcharge simulation of square soft packet lithium-ion batteries under different current rates was carried out. The results show that the changes in battery voltage and temperature under the condition of overcharge have three stages, and the difference between different stages is significant. The thermal effect caused by high-rate current is more obvious, the battery temperature distribution is more uneven, and the area of the high-temperature region is smaller. The heat transfer path is the same and the time is different under different magnifications. Compared with the general model, the modeling strategy presented in this paper has a better adaptability to the temperature rise stage before the battery's internal short circuit occurs.