A CFD thermal analysis and validation of a Li-ion pouch cell under different temperatures conditions

Abstract

Li-ion cells are one of the core components for the actual and future electric mobility. Differently from other types of applications and due to the high charge/discharge rates, the thermal-related issues in batteries for mobility are drastically relevant and can affect the reliability, the safety and the performance of the system. Indeed, limited temperature differences within a battery pack have a significant impact on its efficiency, thus it is important to predict and control the cell and battery pack temperature distribution. In the proposed study, a CFD analysis has been carried out to quantify the temperature and heat distribution on a single li-ion pouch cell. The main objective of this work is to determine the temperature imbalance on the cell and the required cooling load in order to be able to correctly design the cooling system and the best module architecture. The internal heat generation occurs as a result of electrochemical reactions taking place during charge and discharge of batteries. An electric model of the cell allows to assess the thermal power generation; the model parameters are changed according to the operative conditions to improve the accuracy, specifically to take into account varying temperature conditions and C-rates. The high accuracy of the model with respect to experimental data shows the potentiality of the proposed approach to support the optimization of Li-ion modules cooling systems and architecture design.