A Multi-Node Thermal System Model for Lithium-Ion Battery Packs

Temperature is one of the main factors that control the degradation in lithium ion batteries. Accurate knowledge and control of cell temperatures in a pack helps the battery management system to maximize cell utilization and ensure pack safety and service life. In a pack with arrays of cells, a cell's temperature is not only affected by its own thermal characteristics but also by its neighbors, the cooling system and pack configuration, which increase the noise level and the complexity of cell temperature prediction. This work proposes to model lithium-ion packs' thermal behavior using a multi-node thermal network model, which predicts the cell temperatures by zones. The model was parametrized and validated using commercial lithium-ion battery packs.