Electro-Thermal Degradation Modeling for Fast-Charging Large-Format Prismatic Cells
Electro-thermal degradation modeling reveals that internal thermal gradients accelerate localized lithium plating and active inventory loss during fast charging.
Electro-Thermal Modeling
Meaning
Mathematical simulation approach that couples electrical behavior with heat generation to predict battery performance across varying loads. Engineers use electro-thermal modeling to calculate the temperature gradients within a cell as it undergoes high-current discharge. This process accounts for Joule heating and the entropy changes in the cathode and anode materials during lithiation.
Model Complexity
Complexity of the simulation varies from lumped-parameter models to multi-dimensional finite element analysis. An effective electro-thermal modeling framework incorporates the thermal conductivity of the current collectors and the electrolyte to identify potential hot spots.
Design Optimization
Optimization of the cooling system relies on the data generated by these virtual tests. By running electro-thermal modeling during the concept phase, designers can adjust the thickness of thermal interface materials or the flow rate of the coolant before physical prototypes are built. The simulation captures how heat moves through the cell tabs and the busbars, which are often the primary heat sources during fast charging.
It also predicts how a cell will behave at different ages as internal resistance increases and thermal management becomes more difficult.
Predictive Accuracy
Accuracy of the results is validated by comparing the simulation against data from a climatic chamber. Once verified, electro-thermal modeling provides the foundation for the software logic used by the battery management system to prevent overheating.