中文摘要：

基于电化学-热耦合模型研究聚合物锂离子动力电池放电过程热行为,分析了放电倍率、冷却条件对电池放电过程的温度变化及分布的影响规律.结果表明：3C放电时,模型计算结果与实测结果的平均偏差为0.57K,方差为0.15,说明模型准确度较高.电芯的平均生热率在整个放电过程中呈现出增加的趋势,初期和末期增长较快.大倍率放电时,与电流密度的平方呈正比的不可逆热所占的比重较大,小倍率放电时,电化学反应可逆热占主导.改善冷却条件能降低电池放电过程的平均温度,对流传热过程的表面传热系数为5W/（m^2·K）,1C,3C,5C放电结束时,电芯的平均温升为分别为6.46K,17.67K,27.53K,当对流传热过程的表面传热系数增加至25W/（m^2·K）时,温升比自然对流条件下相同倍率放电时的温度分别降低了2.91K,4.68K,5.62K,但电芯温度分布的不一致性也会加剧.

英文摘要：

To understand the thermal effect of polymer Li-ion cells during the discharge process, an electrochemical thermal coupling model was established to investigate the thermal behavior of the cell. The average deviation and variance between the modeling results and the experimental data at 3C discharge rate were 0.57 K and 0.15, thus it was concluded that the modeling results agreed well with the experimental data. Also, the model is used to analyze the temperature distribution affected by discharge rate and cooling condition. The average heat production rate of the cells shows an increasing trend throughout the discharge process; it is increased significantly at both the beginning and the end of discharge. At a high discharge current, the irreversible heating which is proportional to the square of the current density, is the major heat generation source inside the battery. At a low discharge current, the heat production rate is dominated by reversible entropic heat. Improving cooling temperature could lower the average temperature during the discharge process. When the heat coefficient is 5 W/（m^2·K）, the average temperature rises of the battery cells are 6.46 K, 17.67 K, 27.53 K for 1C, 3C, 5C discharge rates respectively. If the heat coefficient increases to 25 W/（m^2·K）, the average temperatures of the battery cells are reduced by 2.91 K, 4.68 K, 5.62 K for 1C, 3C, 5C discharge rates, respectively, but the inner temperature difference would be increased.