Modeling Lithium Ion Battery Safety: Venting of Pouch Cells: NREL (National Renewable Energy Laboratory)

This report documents the successful completion of the NREL July milestone entitled 'Modeling Lithium-Ion Battery Safety - Complete Case-Studies on Pouch Cell Venting,' as part of the 2013 Vehicle Technologies Annual Operating Plan with the U.S. Department of Energy (DOE). This work aims to bridge the gap between materials modeling, usually carried out at the sub-continuum scale, and the Multi-Scale-Multi-Domain (MSMD) models. In FY12, we developed component models for the electrodes, interfaces, electrolytes, etc., that incorporate the material properties calculated from micro-scale simulations to establish this connection. In FY13, these component models were integrated into cell-level simulations. As the first set of case studies to demonstrate the utility of these models, venting in-pouch format lithium-ion cells under different abuse scenarios was simulated. The build-up and distribution of pressure within the cell is calculated from the component-level models. Gas evolution at the electrode/electrolyte interface as a function of parameters like surface roughness and electrolyte viscosity are included. The cell-level response is then calculated using these estimates. Some preliminary experimental data collected in collaboration with Sandia National Laboratories and the Johnson Space Center at NASA are compared to the model predictions. Multi-Scale-Multi-Domain (MSMD) models. In FY12, we developed component models for the electrodes, interfaces, electrolytes, etc., that incorporate the material properties calculated from micro-scale simulations to establish this connection. In FY13, these component models were integrated into cell-level simulations. As the first set of case studies to demonstrate the utility of these models, venting in-pouch format lithium-ion cells under different abuse scenarios was simulated. The build-up and distribution of pressure within the cell is calculated from the component-level models. Gas evolution at the electrode/electrolyte interface as a function of parameters like surface roughness and electrolyte viscosity are included. The cell-level response is then calculated using these estimates. Some preliminary experimental data collected in collaboration with Sandia National Laboratories and the Johnson Space Center at NASA are compared to the model predictions.