Abstract: Li-ion battery as the energy storage and power source system for EV(s)/HEV(s), which is limiting the EV(s) development due to the safety, reliability and stability. Besides, the performance of Li-ion battery is very sensitive to temperature; and over-high temperature and inhomogeneous can result a sharp drop in battery performance. The phase change materials (PCM) was prepared by paraffin/expanded graphite/low density polyethylene (PA/EG/LDPE) and used as a heat dissipation method for battery module. Experiment to tests the heat dissipation ability of the battery module with or without phase change materials. The temperature, voltage and internal resistance of the battery are collected in real-time by the data collector, and the trend of the parameters is analyzed qualitatively. The results demonstrated that the composites of PA/EG/LDPE have an excellent heat dissipation capability and temperature uniformity capability. The battery module of maximum temperature and maximum temperature gradient are controlled within 55℃ and 5℃, respectively.

Key words: Li-ion battery, safety, instability, heat transfer, phase change material

摘要： 锂离子电池作为纯电动和混合动力汽车的动力存储和供给系统，其安全性、可靠性和稳定性严重地制约了电动汽车的发展。此外，锂离子电池的性能对温度非常敏感，温度过高和不一致都会导致电池性能的急剧下降。本文通过制备石蜡/膨胀石墨/低密度聚乙烯相变复合材料用作电池模组的散热组件，实验测试电池模组在有无相变材料条件下的散热能力。通过数据采集器在线实时采集电池的温度、电压和内阻等状态参数，定性地对比分析各参数的一致性变化趋势。研究结果表明，PA/EG/LDPE复合相变材料具有优越的控温能力以及均温能力，最大温度和最大温度差分别控制在55℃和5℃以内。

关键词: 锂离子电池, 安全性, 不稳定性, 传热, 相变材料