面向动力锂电池热管理的液冷散热性能试验研究

Experimental research on liquid cooling heat-dissipation performance for thermal management of power lithium batteries

为研究动力锂电池的液冷散热效果,文中通过自主搭建的面向液冷的电池热管理试验平台,试验研究了不同环境温度、不同放电倍率及不同冷却液温度下的电池液冷散热性能,并通过所建立的能量模型,对锂电池工作时的能量效率进行了探究。试验结果表明:锂电池表面温度和温差随环境温度和放电倍率的增大而增大,而在环境温度30℃和3 C放电倍率下,锂电池表面温度和温差均超过安全值。此外,调节冷却液温度对控制锂电池表面温度变化有较好效果,对低温环境下放电效率低的问题也有一定的改善作用。锂电池放电能量效率随温度升高而增大,随放电倍率升高而降低,最高能量效率出现在环境温度30℃和1 C放电倍率,最低能量效率出现在环境温度10℃和3 C放电倍率。在环境温度较低的情况下,提高冷却液温度可适当改善锂电池的能量效率。

In this article,in order to explore the liquid-cooling effect of power lithium batteries,the liquid cooling heat-dissipation performance is tested with different ambient temperatures,discharge rates and coolant temperatures by setting up an independent liquid-cooling thermal-management experimental platform.By means of the energy model,the energy efficiency of lithium batteries is explored.The results show that the surface temperature and the temperature difference of lithium batteries go up with the ever-increasing ambient temperature and discharge rate;the surface temperature and the surface temperature difference exceed the safe values at the ambient temperature of 30℃and the discharge rate of 3 C.In addition,the change of the surface temperature of lithium batteries is be well controlled by adjusting the coolant temperature,and the low charging efficiency in the low temperature environment can be improved to some extent.The discharge energy efficiency increases with the evergrowing temperature,but decreases with the ever-growing discharge rate.The highest energy efficiency occurs at 30℃and 1 C discharge rate at the ambient temperature;the lowest energy efficiency occurs at 10℃and 3 C discharge rate at the ambient temperature.In the case of low ambient temperature,the energy efficiency of lithium batteries can be improved by increasing the coolant temperature.