Imperial College London
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Prof. Ifan E. L. Stephens

Faculty of Engineering, Department of Materials

Professor in Electrochemistry
 
 
 
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Contact

 

+44 (0)20 7594 9523i.stephens Website

 
 
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Location

 

Molecular Sciences Research HubWhite City Campus

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Summary

 

Publications

Citation

BibTex format

@article{Páez:2023:10.1021/acsenergylett.3c01596,
author = {Páez, Fajardo GJ and Fiamegkou, E and Gott, JA and Wang, H and Temprano, I and Seymour, ID and Ogley, MJW and Menon, AS and Stephens, IEL and Ans, M and Lee, TL and Thakur, PK and Dose, WM and De, Volder MFL and Grey, CP and Piper, LFJ},
doi = {10.1021/acsenergylett.3c01596},
journal = {ACS Energy Letters},
pages = {5025--5031},
title = {Synergistic Degradation Mechanism in Single Crystal Ni-Rich NMC//Graphite Cells},
url = {http://dx.doi.org/10.1021/acsenergylett.3c01596},
volume = {8},
year = {2023}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Oxygen loss at high voltages in Ni-rich NMC//graphite Li-ion batteries promotes degradation, but increasing evidence from full cells reveals that the depth of discharge choice can further accelerate aging, i.e., synergistic degradation. In this Letter, we employ cycling protocols to examine the origin of the synergistic degradation for single crystal Ni-rich NMC//graphite pouch cells. In regimes where oxygen loss is not promoted (V < 4.3 V), a lower cutoff voltage does not affect capacity retention (after 100 cycles), despite significant graphite expansion occurring. In contrast, when NMC surface oxygen loss is induced (V > 4.3 V), deeper depth of discharge leads to pronounced faster aging. Using a combination of post-mortem analysis and density functional theory, we present a mechanistic description of surface phase densification and evolution as a function of voltage and cycling. The detrimental impact of this mechanism on lithium-ion kinetics is used to explain the observed cycling results.
AU  - Páez,Fajardo GJ
AU  - Fiamegkou,E
AU  - Gott,JA
AU  - Wang,H
AU  - Temprano,I
AU  - Seymour,ID
AU  - Ogley,MJW
AU  - Menon,AS
AU  - Stephens,IEL
AU  - Ans,M
AU  - Lee,TL
AU  - Thakur,PK
AU  - Dose,WM
AU  - De,Volder MFL
AU  - Grey,CP
AU  - Piper,LFJ
DO  - 10.1021/acsenergylett.3c01596
EP  - 5031
PY  - 2023///
SP  - 5025
TI  - Synergistic Degradation Mechanism in Single Crystal Ni-Rich NMC//Graphite Cells
T2  - ACS Energy Letters
UR  - http://dx.doi.org/10.1021/acsenergylett.3c01596
VL  - 8
ER  -
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