Predicting anisotropic thermophysical properties and spatially distributed heat generation rates in pouch lithium-ion batteries

This paper proposes a novel thermal characterization approach to determine the specific heat capacity, anisotropic thermal conductivities, and spatially distributed heat generation rates of pouch lithium-ion batteries (LIBs) through a combined experimental and numerical simulation process. Unlike cylindrical LIBs, pouch LIBs subjected to high C-Rates exhibit non-uniform heat generation distributions due to the combined effect of their low impedance, large size, and internal structure. These thermophysical properties and distributed heat generation rates are crucial for designing, modeling, and assessing the performance of pouch-based battery thermal management systems. The proposed thermal characterization approach does not require expensive lab equipment and extensive details of the battery internal structure. Instead, it relies on simple battery experiments integrated with numerical modeling to predict these properties through inverse heat transfer simulations. The characterization approach accounts for non-uniform heat generation distribution through a geometric factor that discretizes the battery volume into three regions, and concentration factors that determine the percentage of the total heat generation rate in each region. Finally, the validation of the characterization approach and its accuracy is assessed with experimental data independent of that used in the characterization process.

Automated summary

This paper introduces a novel thermal characterization approach for pouch lithium-ion batteries, which determines key thermophysical properties and heat generation rates through a combination of experimental and numerical simulation processes. The approach is practical, cost-effective, and does not require extensive equipment or detailed internal structure information.