Development of a physics-based electrochemical and thermal model of Li-ion batteries for microcontroller applications

Enabling fast-charging procedures is one of the key challenges of Li-ion battery applications, from automotive to power tools. A promising strategy for realizing reliable fast-charging algorithms in battery systems involves employing model-based estimations of internal cell states and integrating these predictions into the charging control. Utilizing this approach to simulate cells during charging reduces the risk of plating, thereby enhancing safety as well as cycle stability. However, achieving accurate model predictions requires substantial computational effort and extensive parameterization, making onboard application on a simple battery management system (BMS) challenging. To address this gap, a reduced physicochemical and thermal model is developed capable of running on a basic microcontroller (MCU). This model comprises the electrochemical processes, including the anode potential, which enables e.g., plating-relevant state estimation. Combined with the thermal model, it also considers the cell’s thermal behavior and temperature-driven parameter changes.