The lithium-ion battery has been considered as a power source of electric vehicles (EVs). An efficient battery thermal management system is essential for lithium-ion batteries with high cooling performance and long lifetime. The objective of this study is to investigate the performance improvement of a novel direct two-phase refrigerant cooling over a conventional liquid cooling for traction batteries of EVs. Based on full-scale experiments under actual vehicle conditions, the thermal performance of the two-phase refrigerant cooling is compared with that of the conventional liquid cooling with the same outer size. The two-phase refrigerant cooling satisfies the maximum cell temperature limit of 45 °C even under harsh environmental conditions. During aging, the two-phase refrigerant cooling provides 16.1% higher battery capacity and 15.0% lower internal resistance compared with the liquid cooling under harsh environmental conditions. Overall, the two-phase refrigerant cooling is considered a preferred alternative to the conventional liquid cooling owing to its reliable performance even with a simple and lightweight structure.

锂离子电池已被视为电动汽车（EV）的电源。高效的电池热管理系统对于具有高冷却性能和长寿命的锂离子电池至关重要。这项研究的目的是研究新型的直接两相制冷剂在电动汽车牵引电池上的常规液体冷却性能上的改进。根据实际车辆条件下的大规模实验，将两相制冷剂冷却的热性能与相同外形尺寸的常规液体冷却的热性能进行了比较。即使在恶劣的环境条件下，两相制冷剂冷却也能满足45°C的最高电池温度限制。在老化过程中，两相制冷剂冷却可提高电池容量16.1％，并提供15。与恶劣环境条件下的液体冷却相比，内部电阻降低了0％。总体而言，两相制冷剂冷却被认为是常规液体冷却的优选替代方法，这是因为两相制冷剂即使具有简单轻巧的结构也具有可靠的性能。