Direct observations of electrochemically induced intergranular cracking in polycrystalline NMC811 particles
File(s)d3ta03057a.pdf (1.56 MB)
Published version
Author(s)
Type
Journal Article
Abstract
Establishing the nature of crack generation, formation, and propagation is paramount to understanding the degradation modes that govern decline in battery performance. Cracking has several possible origins; however, it can be classified in two general cases: mechanically induced, during manufacturing, or electrochemically induced, during operation. Accurate and repeatable tracking of operational cracking to sequentially image the same material as it undergoes cracking is highly challenging; observing these features requires the highest resolutions possible for 3D imaging techniques, necessitating very small sample geometry, while also achieving realistic electrochemical performance. Here, we present a technique in which particle cracking can be completely attributed to electrochemical stimulation via sequential ex situ imaging in a laboratory X-ray nano computed tomography (CT) instrument. This technique preserves the mechanical and electrochemical response of each particle without inducing damage in the particles except for the effects of high voltage. Significant cracking within the core of secondary particles was observed upon the electrochemical delithiation of NMC811, which propagated radially. As X-ray computed tomography allows for imaging of the particle cores, the particles were not required to be modified/milled, guaranteeing any synthesis induced strain in the particles was maintained during the whole technique, resulting in an observation that contrasts crystallographic data, suggesting a significant volume expansion of the secondary particles.
Date Issued
2023-10-21
Date Acceptance
2023-09-11
Citation
Journal of Materials Chemistry A, 2023, 11 (39), pp.21322-21332
ISSN
2050-7488
Publisher
Royal Society of Chemistry
Start Page
21322
End Page
21332
Journal / Book Title
Journal of Materials Chemistry A
Volume
11
Issue
39
Copyright Statement
This journal is © The Royal Society of Chemistry 2023. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
License URL
Identifier
http://dx.doi.org/10.1039/d3ta03057a
Publication Status
Published
Date Publish Online
2023-09-18