Analysis of Influencing Factors of Thermal Management System for LiFePO4 Lithium Battery under High Power Charging

Abstract

During the high-power charging process, the heat generated by the power battery is significantly increased, resulting in a significant temperature rise, which will bring safety hazards and worsens capacity degradation. In this study, we focus on the energy storage system composed of LiFePO4 pouch battery cells whose capacity is 30Ah. The coupling calculation between the one-dimensional electro-chemical model and the 3D heat generation model is realized. The accuracy of the model is verified by charging the battery at different rates. The results show that the inlet flow rate and the cooling channel size within a certain range has a great influence on the cooling effect of the battery pack during high power charging process. Comparing the temperature distribution of the battery pack under different charging rates, the electrochemical-heating coupling model established in this study can truly reflect the heat generation of the battery. Through the calculation of the heat generation of the battery pack, the boundary conditions of the cooling system design can be found, which provides a basis for the optimal design of the conditional cooling system for battery high-power charging.