Investigating Electro-Thermal Distribution in High-Capacity Large-Format Blade Batteries for Energy Storage

Batteries are regarded as a uniform heat source in traditional thermal management system design. Inconsistencies in electrochemical reactions across time and space are often ignored, which leads to an unreasonable battery thermal management system. This paper establishes a 2D electro-thermal fully coupled model based on the Kim model and NTGK model for a high-capacity blade battery. Based on the experimental results, the accuracy of the model was verified by examining terminal voltage, average battery temperature, and temperature distribution. The distribution characteristics of physical fields within the battery were analyzed using the electro-thermal model. The results indicated that the distribution of electrochemical reaction rates inside the battery shows a clear boundary between the near-tab area and the middle positions. In the initial stage of discharge, the electrochemical reaction rates were higher around the tabs. However, the electrochemical reaction rates were higher around the middle positions at the end stage of discharge. Thus, we proposed two schemes, a three-zone model and a five-zone model for 3D thermal analysis, according to the distribution characteristics of the physical fields. We found that the difference in the prediction accuracy of temperature distribution between the two schemes was small. Therefore, we recommended the three-zone scheme for 3D thermal analysis, considering the complexity of the operation. These conclusions could provide a reference for a refined thermal management system design of large-sized blade batteries.