Applying Numerical Simulation to Model Varying Process and Cell Parameters during the Electrolyte Filling Process of Lithium-Ion Batteries

The electrolyte filling process is considered one of the bottlenecks of lithium-ion battery production due mainly to the long electrolyte wetting times. Additionally, the required experimental process design is time and material-intensive, increasing the development costs of new materials or cell designs. A model of the filling process would allow for more efficient cell production, but until now, the published models have mainly been focused on individual components on a pore scale. Within the scope of this work, the model setup for a holistic examination of the electrolyte filling process is shown, allowing the study of the electrolyte wetting on a cell scale. The characteristic values of a porous medium, such as the permeability, are calculated with a microsimulation of an anode and a cathode pore structure. These values are then transferred to the ANSYS porous media model, and cell scale simulations are performed. Two cell formats and variations in the evacuation pressure and electrolyte temperature are simulated and compared to experimental wetting data. The results show that the simulation successfully models the wetting behavior for the investigated cell formats and cell assembly types, validating the model with experimental data both qualitatively and quantitatively.