基于热成像的软包锂电池导热系数测试方法

Test Method of Thermal Conductivity of Pouch Lithium-ion Cell Based on Thermography

为给软包锂电池热设计提供准确的导热系数值,提出了一种基于热成像技术的测试方法。通过热像仪记录电池表面温度场的演变数据,可同时反演电池的纵向和面向导热系数,避免了传统接触式表面测温引入的不确定因素。测试了多块不同规格的三元聚合物软包锂电池样品,并对其中一种样品进行了稳态法导热系数测量作为参考。结果显示,纵向和面向导热系数测试的相对标准差均在3%以内,纵向导热系数的测试结果与稳态法测量结果的相对偏差为3.1%,表明该方法具有较高的可靠性,可为电池的热设计提供参考。

To provide accurate thermal conductivity value for thermal design of pouch lithium-ion cell,a test method based on thermography was proposed,which could invert the cross-plane and in-plane thermal conductivity of cell at the same time with the temperature filed data of cell surface recorded by thermal camera,avoiding the uncertainty factors brought by traditional contact temperature measurement.Several ternary polymer lithium-ion cell samples with different specifications were tested,and one type of samples was measured with steady-state method as a reference.The experimental results showed that the relative standard deviation of cross-plane and in-plane conductivity was less than 3%,and the relative deviation compared with the results of steady-state method of cross-plane conductivity was 3.1%.Therefore,the method was reliable and could provide reference data for the thermal design of cells.