Dimensionless normalized concentration based thermal-electric regression model for the thermal runaway of lithium-ion batteries

Thermal runaway (TR) has become a critical issue for lithium-ion battery-based electric vehicles (EVs) and energy storage stations. Accurate thermal-electric estimation is significant for the safety of lithium-ion batteries (LIB). To predict the highly correlated behavior of temperature and voltage variation characteristics during the TR process, a thermal-electric coupled TR model within the full range of State of Charge (SOC) is constructed in this study. The electric quantity normalized concentration c eq is defined and used to construct the corresponding numerical relationship between temperature and voltage in the model. This model can effectively fit the battery TR temperature and voltage variation behavior under both adiabatic TR test and oven test results. Furthermore, the model-based analysis proves that the temperature and voltage changes during the TR can be mutually obtained through the stable numerical coupling relationship. Besides, the relationship between SOC and the concentration field is established. Moreover, the feasibility of using the normalized concentration to couple the voltage and temperature signal is verified. This study provides perspectives for the coupling relationships of TR characteristic signals and multi-signal coupled modeling of lithium-ion battery TR. ● A thermal-electric coupled model is proposed for the full range of SOC. ● The maximum error of voltage estimation model is less than 0.05 V. ● This study guides the multi-signal coupled thermal runaway state estimation. ● The proposed methodology can be utilized for thermal runaway propagation modeling.