Surface Cooling Causes Accelerated Degradation Compared to Tab Cooling for Lithium-Ion Pouch Cells
Surface Cooling Causes Accelerated Degradation Compared to Tab Cooling for Lithium-Ion Pouch Cells
复制标题
DOI：
10.1149/2.0361609jes
复制
发表时间：
2016-01-01
影响因子：
3.9
通讯作者：
Offer, G. J.
中科院分区：
文献类型：
--
作者：
Hunt, Ian A.;Zhao, Yan;Offer, G. J.
锂离子电池退化的最大原因之一是温度升高。在这项研究中，我们探索了电池表面冷却和电池片冷却的影响，重现了在现实世界中使用的两种典型冷却系统。对于使用慢速标准化测试的新电池，容量差异很小。然而，在更高的速率下，电池在10分钟内放电，表面冷却会导致9.2%的可用容量损失，而电池片冷却会导致1.2%的可用容量损失。在电池循环1000次后，表面冷却导致负载下可用容量的损失率是电池表面冷却的三倍。我们表明，这是由于热梯度垂直于表面冷却层，导致更高的局部电流和更快的降解，但与标签冷却层的平面内导致更均匀的行为。因此，了解热管理系统如何与电池的运行相互作用对于延长电池的性能至关重要。对于汽车应用，80%的容量被认为是寿命终止，因此，使用标签冷却而不是表面冷却将相当于延长电池组的使用寿命3倍，或将寿命成本降低66%。(C)作者2016。由ECS出版。版权所有。
One of the biggest causes of degradation in lithium-ion batteries is elevated temperature. In this study we explored the effects of cell surface cooling and cell tab cooling, reproducing two typical cooling systems that are used in real-world battery packs. For new cells using slow-rate standardized testing, very little difference in capacity was seen. However, at higher rates, discharging the cell in just 10 minutes, surface cooling led to a loss of useable capacity of 9.2% compared to 1.2% for cell tab cooling. After cycling the cells for 1,000 times, surface cooling resulted in a rate of loss of useable capacity under load three times higher than cell tab cooling. We show that this is due to thermal gradients being perpendicular to the layers for surface cooling leading to higher local currents and faster degradation, but in-plane with the layers for tab cooling leading to more homogenous behavior. Understanding how thermal management systems interact with the operation of batteries is therefore critical in extending their performance. For automotive applications where 80% capacity is considered end-of-life, using tab cooling rather than surface cooling would therefore be equivalent to extending the lifetime of a pack by 3 times, or reducing the lifetime cost by 66%. (C) The Author(s) 2016. Published by ECS. All rights reserved.