Temperature field evolution of cylindrical battery: In-situ visualizing experiments and high fidelity internal morphology simulations

Modeling and measurement of the temperature distribution in cylindrical Li-ion cells are critical challenges that directly affect both the performance and safety. Most available electrochemical-thermal models for cylindrical cells are validated through the surface temperature. In this paper, high fidelity internal morphology two-dimensional electrochemical-thermal models based on geometric parameters extracted from computed tomography images are developed for the 18650 cylindrical Li-ion battery. An optical cell has been made to obtain the inner temperature distribution on the cross-section by using an infrared camera. The modeling results are validated for both the electrochemical performance and thermal behavior during the galvanostatic discharge process. The modeling results agree with the experimental data of the optical cell well. The effects of the inlet ratio, jelly roll structure and positive tab position on the temperature field on the cross-section are analyzed. The results presented in this paper contribute to the modeling and manufacturing of 18650 cylindrical Li-ion batteries.