Sensitivity Analysis of Thermal Runaway Side Reaction of Lithium Batteries Based on Morris Method

Abstract

In the field of electric vehicles, the safety of power lithium-ion batteries is a socially important issue, and the study of thermal runaway of lithium batteries is now gradually becoming more in-depth. In this paper, the output parameters are up-dimensioned. Using a global sensitivity analysis method based on the Moms screening method, the influence of 11 parameters such as volume of the cell(vBt), mass of the cell(mBt) and electrolyte concentration $(\mathrm{W}_{\mathrm{e}})$ on the thermal runaway process of Li-ion batteries is analyzed, and the variation of 10 variables such as temperature(T) and carbon dioxide gas (CO2) produced in the thermal runaway side reaction heat generation process and chemical reaction gas generation process over time is investigated under the influence of the parameter factors. In the study, the sensitivity of the parameters over a time interval is investigated in the rising dimension of the time domain. The results show that the overall effect of the parameters on the thermal process; for the output variables of the thermal process, they are mainly affected by the mass of the cell $(\mathrm{m}_{\mathrm{Bt}})$, the thickness of the SEI film $(\mathrm{t}_{\mathrm{sei}})$ and the specific heat capacity of the cell$(\mathrm{Cp}_{\mathrm{Bt}})$, while the chemical process is not significantly affected by the different parameters; among all the parameters, the volume $(\mathrm{V}_{\mathrm{Bt}})$ of the cell interacts most strongly with the other parameters for all the output variables. Finally, the results of the sensitivity analysis of the thermal runaway side reactions of the battery will be applied to the subsequent 3D simulation study.