Simulation and Characteristic Analysis of High-Temperature Thermal Runaway Process in Ternary Lithium- Ion Batteries

Abstract

Abstract This study addresses the thermal safety issues of ternary lithium-ion batteries, focusing on NCM523 monomer lithium-ion batteries as the research subject. A thermal abuse model for lithium-ion batteries is established, and thermal Oven experiments are simulated to investigate the thermal runaway (TR) process of lithium-ion batteries under high-temperature conditions (135°C ~ 195°C). The study analyzes the impact of various factors such as environmental temperature, state of charge (SOC) of the battery, initial battery temperature, and heat transfer coefficient on the thermal runaway of lithium-ion batteries. Additionally, it examines the changes in the internal material content of the battery and heat generation in various parts of the battery during the thermal runaway process. The research reveals that at an oven temperature of 195°C, the maximum temperature during the thermal runaway of lithium-ion batteries can reach approximately 625°C. The reactions between the negative electrode and electrolyte, as well as the positive electrode and electrolyte, are the primary sources of heat generation during thermal runaway. An increase in the state of charge of the battery leads to an earlier onset of thermal runaway. Furthermore, an increase in the heat transfer coefficient results in an earlier onset of thermal runaway. Implementing appropriate cooling methods (liquid cooling or direct cooling) can to some extent prevent the occurrence of thermal runaway phenomena.