冷板阻热层对锂电池模组散热均匀性影响

The effect of heat barrier layer of cold plate on the heat dissipation uniformity of li-battery modules

锂电池模组温差过大引发电池间充放电、老化衰减速率不一致,致使其性能变差。为了进一步降低锂电池模组工作温差,提出一种设阻热层的新型冷板,即通过在冷板冷却液入口处与锂电池间增设阻热层增大热阻、抑制锂电池与冷板间热交换改善其散热均匀性。利用新型冷板对锂电池模组3 C放电冷却散热进行建模仿真计算,分析了并行流道、并联蛇形流道以及分叉型流道等3种不同流道冷板增设阻热层对锂电池模组放电散热均匀性影响,以及阻热层材料导热系数、厚度及覆盖面积对锂电池模组冷却散热均匀性影响。结果表明:在3种流道冷板上增设阻热层均能有效降低锂电池模组工作温差。随着阻热层材料导热系数减小,锂电池模组最高温度和温差均先减小后增加。随着阻热层厚度、阻热层覆盖面积增大,锂电池模组工作最高温度和温差均先减小后增大。采用长80 mm、宽80 mm、厚1 mm导热硅胶垫阻热层,分叉型流道冷板冷却锂电池模组3 C放电最高温度和温差降至306.55 K和4.89 K。

The large temperature difference between lithium battery modules leads to inconsistent charging,discharging,and aging rates between batteries,resulting in poor performance.In order to further reduce the working temperature difference of lithium battery modules,a new type of cold plate with a thermal barrier layer is proposed,which increases thermal resistance by adding a thermal barrier layer between the cooling liquid inlet of the cold plate and the lithium battery,suppresses heat exchange between the lithium battery and the cold plate,and improves its heat dissipation uniformity.The lithium-ion battery module discharging with 3C cooled by these new type cold plate was simulated.Three cold plates with different flow channels,including parallel flow channels,parallel serpentine flow channels,and forked flow channels,were analyzed.The effect of adding a heat barrier layer to the cold plate on the uniformity of discharge heat dissipation of lithium-ion battery module,as well as the influence of the thermal conductivity,thickness,and coverage area of the heat barrier layer on the uniformity of cooling and heat dissipation of lithium-ion battery module were analyzed.The results show that adding a heat barrier layer can effectively reduce the working temperature difference of lithium battery modules for the three different cold plates.As the thermal conductivity of the thermal barrier material decreases,the maximum temperature and temperature difference of the lithium battery module first decrease and then increase.As the thickness and coverage area of the thermal barrier layer increase,the maximum operating temperature and temperature difference of the lithium battery module first decrease and then increase.Using a thermal conductive silicone pad with a length of 80 mm,width of 80 mm,and thickness of 1 mm,the lithium battery module is cooled by a bifurcated channel cold plate with a 3C discharge temperature and temperature difference reduced to 306.55 K and 4.89 K.