圆柱形锂离子电池热管理实验研究

摘要

It is necessary to implement effective thermal management strategies to keep the Li-ion batteries work at a desirable temperature or within a temperature range, and thus to guarantee its high efficiency, reliable safety and long lifetime. In this paper, a prismatic metal shell was designed for the cylindrical Li-ion batteries to enhance the heat dissipation and facilitate the heat exchange between neighboring batteries. Experiments were carried out to compare the temperature rise of a single battery or a small group of parallel-connected batteries with or without metal shells assembled under natural or forced air convective cooling conditions at various discharge rates. It was found that heat dissipation of the shelled battery (or small group) was improved greatly. In addition, batteries in a small parallel-connected group were designed to discharge at different rates to record the temperature variation. The result showed that the maximum temperature difference between shelled single cells could be reduced by more than 10oC under natural convection cooling condition.%保持合适的运行温度是锂离子电池高效、安全、长寿命的保证，因而对其进行有效的热管理是非常有必要的。本文针对圆柱形锂离子电池，设计了嵌套电池表面的方形金属外壳，以强化电池散热和单体电池间传热。对比自然对流条件下电池单体加壳和无壳时不同放电倍率的温升情况、多个电池并联的温升情况，以及不同通风功率下多个电池并联时嵌套不同外壳的温升情况，发现加壳可以有效促进电池（组）散热。另外，设计了电池组内不同单体电池出现放电不均衡情况，以检验嵌套外壳对减小电池组内单体电池间温差的效果，结果表明，自然对流条件下，加壳后单体电池间最大温差可以降低10℃以上。