The Thermal Characteristics of Lithium-Ferro-Phosphate (LFP) Battery Pack

Lithium-ion thermal battery management systems are continuously being developed to ensure better battery performance, safety, and capacity. Li-ion battery performance is strongly influenced by its operating temperature. Thus, to maintain its safety and performance, a thermal management system in the form of cooling fluid is necessary to maintain battery temperature. The purposes of this study are to predict the thermal characteristics of LFP battery numerically and determine the temperature distribution among cells in the variations of discharge rate from 0.5C to 1C. A constant 0.1 m/s air flow rate at 25°C are used for evaluating the thermal performance of the twenty-five 26650 LFP battery cells arranged in a 5 × 5 battery pack configurations. In this work, we do both numerical computation and direct experiment. Computational investigation was done using ANSYS Fluent 2020. The battery heat generation model used was Equivalent Circuit Model (ECM) which provided by ANSYS Fluent 2020. Then, the numerical results are validated by an experiment. The data obtained from the experiment are temperatures profile and contours of temperature. The temperature profile is drawn from the data recorded by a 4-channel thermocouple thermometer, while the contours of temperature are captured by using thermal camera. The investigation results reveal that a higher C-Rate gives a higher battery pack temperature; the temperatures achieve in the simulation and experiment show no big difference; and overall battery pack temperatures are below 34°C for 3600 s running. The maximum temperature difference among cells is lower than 5°C. An evenly distributed air flow provides uniform temperature distribution inside the battery pack.