Revealing causes of macroscale heterogeneity in lithium ion pouch cells via synchrotron X-ray diffraction

JOURNAL OF POWER SOURCES

卷:507

Article

Charalambous, Harry¹  Abraham, Daniel P.²  Dunlop, Alison R.²  Trask, Stephen E.²  Jansen, Andrew N.²  Tanim, Tanvir R.³  Chinnam, Parameshwara R.³  Colclasure, Andrew M.⁴  Xu, Wenqian¹  Yakovenko, Andrey A.¹  Borkiewicz, Olaf J.¹  Gallington, Leighanne C.¹  Ruett, Uta¹  Wiaderek, Kamila M.¹  Ren, Yang¹ 

[1] Argonne Natl Lab, Adv Photon Source, Lemont, IL 60439 USA

[2] Argonne Natl Lab, Chem Sci & Engn Div, Lemont, IL 60439 USA

[3] Idaho Natl Lab, Energy Storage & Adv Vehicles Dept, Idaho Falls, ID 83415 USA

[4] Natl Renewable Energy Lab, Ctr Energy Convers & Storage Syst, Golden, CO 80401 USA

关键词: Heterogeneity;    Fast charge;    High voltage;    NMC532;    Graphite;    SEI outgassing;   

DOI  :  10.1016/j.jpowsour.2021.230253

来源: Elsevier

【 摘 要 】

Heterogeneous battery performance is a critical issue for maximization of cell lifetime capacity and safety. Using high energy synchrotron X-ray diffraction, the influence of charge rate, voltage limit, uneven stack pressure, and gas generation on the lithium transport properties was quantified in single-layer graphite/LiNi0.5Mn0.3Co0.2O2 pouch cells. A freshly formatted cell tracked in operando during initial fast charge cycles indicated variable position-dependent performances, while lateral mapping showed a significant fast charge (6C) heterogeneity compared to slow charge (C/2). Pressure effects were non-dominant compared to charge rate. Maps of previously aged and rested cells indicate that lateral heterogeneity slowly equilibrates at rest, but regenerates upon further cycling at fast charge rate. Furthermore, an unformatted cell was mapped at charge and discharge during its first formation cycle to analyze the effect of byproduct gases on the heterogeneous lithium transport. Gas was observed as randomly interspersed bubbles which locally hindered lithium intercalation and caused significant heterogeneity. Electrode architectures and charging protocols that promote homogeneous intercalation are critical for predictable high-performance and long-life batteries.

【 授权许可】

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