使用柔性定型相变材料进行动力电池热管理的实验研究

Experimental study on thermal management of power batteries using flexible shape-stabilized phase change materials

为了应对全球极端天气和能源紧缺问题,我国提出了碳达峰与碳中和的国家战略。锂电池因具有高能量密度和长循环寿命的优势,成为近年来新能源汽车的核心动力元件。但在充放电的过程中,锂离子电池散热是否及时以及表面温度分布是否均匀直接影响电池的电化学性能和安全性能。如何高效地散热以防热失控是高功率锂离子电池的重要关注点。本文制备一种柔性定型相变材料,通过相变材料在相变过程中的吸放热,对锂离子电池进行温控,同时搭建了电池-复合相变材料模型并进行了电池热管理测试。测试结果表明,复合相变材料可以使三元锂离子电池单体在常温下最高下降6.5℃,模组温差由12℃下降至5.5℃;在-30℃下使三元锂离子电池单体最高温度下降4.9℃,模组温差由19.2℃下降至10.3℃。该研究解决了三元锂离子电池高倍率充放电中温度控制的问题,对于提升锂离子电池热管理综合性能具有现实意义。

In response to global extreme weather conditions and energy scarcity,China has proposed the national strategies of carbon peaking and carbon neutrality.Lithium-ion batteries,owing to their high energy density and long cycle life,have become the core power components of new energy vehicles in recent years.However,during the charging and discharging processes,whether lithium-ion batteries dissipate heat in a timely manner and whether the surface temperature distribution is uniform directly affect the electrochemical and safety performance of the batteries.Effectively dissipating heat to prevent thermal runaway is a crucial concern for high-power lithium-ion batteries.This study prepares a flexible shape-stabilized phase change material that utilizes the heat absorption and release during phase change to control the temperature of lithium-ion batteries.Simultaneously,a battery-composite phase change material model is established,and thermal management tests are conducted.The results indicate that the composite phase change material can reduce the highest temperature of the ternary lithium-ion battery cell by up to 6.5℃at room temperature,and the module temperature difference decreases from 12℃to 5.5℃.At-30℃,the highest temperature of the ternary lithium-ion battery cell decreases by 4.9℃,and the module temperature difference decreases from 19.2℃to 10.3℃.This research addresses the temperature control issues during high-rate charge and discharge of ternary lithium-ion batteries,providing practical significance for enhancing the overall thermal management performance of lithium-ion batteries.