Abstract

In this study, distributed cooling ducts (DCDs) and prepared phase change material-expanded graphite composite (PCM-EGC) are utilized to improve the thermal characteristics of Lithium (Li)-ion batteries which are widely used in industry. Theoretical concepts are first discussed to provide a strong basis for the topic, and numerical/simulated results are then presented to validate theoretical results. To provide a comprehensive and clear basis, three Li-ion batteries are technically compared to each other. The first one is a commonly used commercial Li-ion battery, the second one includes 19 DCDs, and the last one comprises 19 DCDs plus PCM-EGC. The following points also being the novelty and contributions of this work are demonstrated:

• Adding DCDs to a battery smoothes the temperature curve distributed across the battery’s unit cells.

• Adding both DCDs and PCM-EGC not only more smoothes the temperature curve but also significantly decreases the maximum temperature of the battery, so that, the operating point of the battery temperature shifts into the safe thermal region of the battery, which is less than $60°\mathrm{C}$ as suggested by manufacturers.

摘要

在这项研究中，分布式冷却管道（DCD）和制备的相变材料膨胀石墨复合材料（PCM-EGC）被用来改善工业中广泛使用的锂（Li）离子电池的热特性。首先讨论理论概念以为该主题提供强有力的基础，然后提供数值/模拟结果以验证理论结果。为了提供全面和明确的依据，我们在技术上对三种锂离子电池进行了比较。第一个是常用的商用锂离子电池，第二个包括19个DCD，最后一个包括19个DCD加上PCM-EGC。以下几点也证明了这项工作的新颖性和贡献：

• 向电池添加 DCD 可以平滑分布在电池单元中的温度曲线。

• 同时添加 DCD 和 PCM-EGC 不仅使温度曲线更加平滑，而且显着降低了电池的最高温度，使电池温度工作点移入电池的安全热区，小于 $60°\mathrm{C}$ 按照制造商的建议。