Surface cooling causes accelerated degradation compared to tab cooling for lithium-Ion pouch cells
File(s)
Published version
Author(s)
Hunt, I
Zhao, Y
Patel, Y
Offer, GJ
Type
Journal Article
Abstract
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%.
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%.
Date Issued
2016-07-01
Date Acceptance
2016-06-17
Citation
Journal of the Electrochemical Society, 2016, 163 (9), pp.A1846-A1852
ISSN
0013-4651
Publisher
Electrochemical Society
Start Page
A1846
End Page
A1852
Journal / Book Title
Journal of the Electrochemical Society
Volume
163
Issue
9
Copyright Statement
© The Author(s) 2016. Published by ECS. This is an open access article distributed under the terms of the Creative Commons
Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any
medium, provided the original work is properly cited. [DOI: 10.1149/2.0361609jes] All rights reserved.
Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any
medium, provided the original work is properly cited. [DOI: 10.1149/2.0361609jes] All rights reserved.
License URL
Sponsor
Engineering & Physical Science Research Council (E
Innovate UK
Engineering & Physical Science Research Council (E
Identifier
https://iopscience.iop.org/article/10.1149/2.0361609jes
Grant Number
EP/I038586/1 - Ref: J12967
132224
EP/R511547/1
Subjects
Science & Technology
Physical Sciences
Technology
Electrochemistry
Materials Science, Coatings & Films
Materials Science
ELECTRIC VEHICLE-BATTERY
AGING MECHANISMS
DESIGN OPTIMIZATION
THERMAL MANAGEMENT
HEAT-GENERATION
CAPACITY FADE
POWER
TEMPERATURE
IMPEDANCE
PERFORMANCE
0303 Macromolecular and Materials Chemistry
0306 Physical Chemistry (incl. Structural)
0912 Materials Engineering
Energy
Publication Status
Published
Date Publish Online
2016-07-01