Reconstruction of Battery System Temperature Field Based on Three-Dimensional Thermal Equivalent Circuit Model

Lithium-ion batteries are extensively utilized across various fields, but their thermal fragility has been seriously concerned. Lithium-ion batteries are easily affected by working temperature, therefore, monitoring the internal temperature of batteries is crucial. In addition, under the action of various composite factors, the temperature inside the battery system usually appears uneven during charging and discharging, which leads to the acceleration of battery aging and the intensification of battery inconsistency. Therefore, reconstructing the temperature field of the battery system can provide multidimensional thermal information that is beneficial to temperature prediction and significantly improve the effectiveness of thermal management of the battery system. Compared with single battery, the temperature estimation of battery system becomes more difficult due to the increase of size and the complex interaction of multiple heat sources. A three-dimensional distributed thermal equivalent circuit modeling method for battery system is proposed, and its model accuracy is validated through experiments. This method offers high accuracy, is adaptable to different battery types, allows for rapid calculation of temperature values at all designated points within the battery system, and enables real-time reconstruction of the temperature field distribution.