lithium ion batteries (LiBs) are considered one of the most suitable power options for electric vehicle (EV) drivetrains, known for having low self-discharging properties which hence provide a long life-cycle operation. To obtain maximum power output from LiBs, it is necessary to critically monitor operating conditions which affect their performance and life span. This paper investigates the thermal performance of a battery thermal management system (BTMS) for a battery pack housing 100 NCR18650 lithium ion cells. Maximum cell temperature (Tmax) and maximum temperature difference (ΔTmax) between cells were the performance criteria for the battery pack. The battery pack is investigated for three levels of air flow rate combined with two current rate using a full factorial Design of Experiment (DoE) method. A worst case scenario of cell Tmax averaged at 36.1 °C was recorded during a 0.75 C charge experiment and 37.5 °C during a 0.75 C discharge under a 1.4 m/s flow rate. While a 54.28% reduction in ΔTmax between the cells was achieved by increasing the air flow rate in the 0.75 C charge experiment from 1.4 m/s to 3.4 m/s. Conclusively, increasing BTMS performance with increasing air flow rate was a common trend observed in the experimental data after analyzing various experiment results.

中文翻译：

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紧凑型锂离子电池模块强制对流冷却的经验热性能研究

锂离子电池（LiB）被认为是电动汽车（EV）动力总成的最合适动力选择之一，以其低自放电性能而著称，因此使用寿命长。为了获得LiB的最大功率输出，有必要严格监视会影响其性能和寿命的工作条件。本文研究了装有100个NCR18650锂离子电池的电池组的电池热管理系统（BTMS）的热性能。电池之间的最高电池温度（Tmax）和最大温度差（ΔTmax）是电池组的性能标准。使用全因子实验设计（DoE）方法研究了电池组的三个水平的空气流速和两个当前的流速。在0.75 C的充电实验中记录了平均最高温度为36.1°C的电池Tmax的最坏情况，而在1.4 m / s的流量下，在0.75 C放电期间记录的平均温度为37.5°C。通过将0.75 C充气实验中的空气流速从1.4 m / s增加到3.4 m / s，可以使电池之间的ΔTmax降低54.28％。总之，在分析各种实验结果后，随着空气流量的增加而增加BTMS性能是在实验数据中观察到的普遍趋势。