Thermal modeling of full-size-scale cylindrical battery pack cooled by channeled liquid flow.

• A thermal model of full-size-scale real EV battery packs is developed. • Thermal management of the battery pack cooled by channeled liquid flow is studied. • The thermal management system is fine-tuned by re-managing the flow distribution. • Parametric studies on discharge/charge C-rate and coolant flow rate are conducted. A numerical study with the aim of upgrading thermal performances of battery pack of electric vehicles is conducted for a full-size-scale battery pack with 22 modules (totally 5664 18650-type lithium-ion batteries contained) cooled by a channeled liquid flow. The heat generation of the battery is modeled based on experimental measurements. Experiments with one typical module (consisting of 180 batteries) of the pack, charging and discharging at different C-rate (2C, 1C or 0.5C) at a specified liquid flow rate, are first carried out. The experimental results in what concerns maximum temperature in the battery module is in good agreement with the corresponding numerical predictions, demonstrating the reliability/fidelity and consequent accuracy of the developed model. The battery thermal management system is then fine-tuned to re-manage the flow distribution among modules for the sake of improving the thermal uniformity across the pack. The effect on the pack thermal performance of different charge/discharge C-rates and flow rates are extensively investigated, and the results indicate that the pack is thermally well-performed during 1C/0.5C discharge/charge operation with a fluid flow rate of 18 L/min; increasing the discharge/charge C-rate worsens the battery pack's thermal characteristics and increasing the coolant flow rate makes the battery pack perform better. [ABSTRACT FROM AUTHOR]