Multitime Scale Analysis of Surface Temperature Distribution of Lithium-Ion Batteries in Quantity–Quality Change under Local High-Temperature Heat Source

Abstract

Lithium-ion batteries are currently the most suitable power source for new energy vehicles. Thermal runaway is the biggest potential safety hazard. To achieve safer battery and battery design, it is necessary to fully understand thermal runaway. Here, a chemical-thermal coupled lithium-ion battery model is established. The temperature distribution rule of a lithium-ion battery surface in quantity–quality change under the influence of an external local high temperature heat source is discussed and analyzed using a multitime scale. The results show that lithium-ion batteries tend to thermal runaway when the temperature of external heat source is higher than a certain value. During this period, the most important thermal reaction is the reaction between anode and electrolyte.