Modeling Vaporization, Gas Generation and Venting in Li-Ion Battery Cells with a Dimethyl Carbonate Electrolyte

This paper presents a mathematical model developed for predicting the temperature-pressure behavior and gas generation inside 18650 LCO/Graphite cells with a DMC (Dimethyl Carbonate) electrolyte. The cell was modeled using oven heating conditions, and the analysis was done at time intervals around the venting event. The paper also presents the thermodynamic property table for DMC, as extracted from different resources and calculated using various assumptions. The model was developed by deriving the energy balance for an unsteady-flow control volume and applying the isentropic flow equations corresponding to the venting of gas. The results show that the model fails to predict the pressure measured experimentally when no gas is generated inside. When adding the gas generation due to pre-venting reactions occurring, the model can predict the pressure profile measured experimentally.