熵热系数取值方式对锂离子电池热模型精度的影响

The Influence of Entropy Heat Coefficient Simplification on the Accuracy of Thermal Model of LIBs

为了提高锂离子电池热模型的生热仿真计算精度,研究了熵热系数取值方式对三元锂离子电池热模型精度的影响。在所建立方形电池的三维热物理模型的基础上,考虑到三元电池熵热系数的非平滑变化规律,提出了电池熵热系数的分段式表征模型。通过仿真、实验分析研究了所提新模型与传统熵热系数取值方式在常温(25℃)自然对流、不同放电倍率条件下的电池温升,结果表明:采用变熵热系数的热模型精度高于传统定熵热系数热模型,其在1C、1.5C、2C放电倍率下的仿真曲线最大误差和均方根误差均明显小于后者,其最大误差在所进行实验中均在1℃之内。

In order to improve the simulation accuracy of the lithium-ion battery thermal model in the process of heat generation calculation,the influence of entropy heat coefficient on the accuracy of the ternary li-ion battery thermal model was studied.Based on a three-dimensional thermophysical model for prismatic batteries,a piecewise model for entropy heat coefficient was proposed considering the non-smooth characteristic of entropy heat coefficient in ternary batteries.Simulations and experiments were carried out to analyze battery temperature rise estimation results of the proposed new model and the traditional methods at different discharge rates.The results show that the maximum error and the root-mean-square error with the new model are definitely superior to the traditional one at all of 1C,1.5C and 2C discharge rates,and their maximum error can be reliably controlled within 1℃.