十四醇软包锂电池散热特性实验分析

Experimental analysis of heat dissipation characteristics of soft lithium battery with tetradecyl alcohol

在空气自然对流状况下,研究了有机醇相变材料(十四醇)对软包方形锂电池放电过程的散热特性;同时建立锂电池散热系统物理模型,模拟相变体系中电池放电过程的温度变化,分析不同放电倍率对电池最高温度的影响。实验结果表明,环境温度为30℃时,在0.6C、0.8C和1.0C放电倍率下,锂电池温度分别下降了1.21℃、8.89℃和17.45℃;数值计算得出,环境温度为30℃时,锂电池在0.8C和1.0C放电倍率条件下,电池温度45℃以上的时长占比分别下降55%和58%;环境温度为35℃时,在1.0C放电倍率条件下,锂电池温度降低至65.14℃,超45℃时长占比为33%。相变材料只在其相变区间内起散热控温作用,数值模拟获得的电池温度变化与实验结果最大误差不超过2℃,研究结果对电池放电过程热管理技术应用有一定的参考意义。

The heat dissipation characteristics of the organic alcohol phase change materials(PCM)based soft-clad square lithium batteries at discharging and under natural air convection were studied. The physical model of battery thermal management system was established to simulate the change of battery discharge temperature in phase change system and to analyze the influence of different discharge magnifications on the maximum temperature of lithium battery. The results showed that when the ambient temperature was 30℃, the center point temperatures decreased by 1.21℃, 8.89℃ and 17.45℃respectively under the discharges of 0.6 C, 0.8 C and 1.0 C magnification. The result of numerical simulation showed that the time of temperature above 45℃ decreased by 55% and 58% respectively when the ambient temperature was 30℃ and the discharges were 0.8 C and 1.0 C magnification. When the ambient temperature was 35℃ and the discharge was 1.0 C magnification, the temperature decreased to65.14℃, and the time of temperature above 45℃ was 33%. The phase change material played the role of heat dissipation and temperature control only in its phase change intervals, and the maximum error between the simulation and the experimental results did not exceed 2℃. The result has a reference significance for the application of thermal management technology in battery discharge process.