“Electrochemical Shock” of Intercalation Electrodes: A Fracture Mechanics Analysis
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Carter_Electrochemical shock.pdf
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Author(s)
Chiang, Yet-Ming
Carter, W. Craig
Woodford, William Henry
Date Issued
August 2010
Journal
Journal of The Electrochemical Society
Publisher
The Electrochemical Society
Citation
Woodford, William H., Yet-Ming Chiang, and W. Craig Carter. “Electrochemical Shock” of Intercalation Electrodes: A Fracture Mechanics Analysis. Journal of The Electrochemical Society 157, no. 10 (2010): A1052. © 2010 ECS - The Electrochemical Society
Version
Final published version
Abstract
Fracture of electrode particles due to diffusion-induced stress has been implicated as a possible mechanism for capacity fade and impedance growth in lithium-ion batteries. In brittle materials, including many lithium intercalation materials, knowledge of the stress profile is necessary but insufficient to predict fracture events. We derive a fracture mechanics failure criterion for individual electrode particles and demonstrate its utility with a model system, galvanostatic charging of Li[subscript x]Mn[subscript 2]O[subscript 4]. Fracture mechanics predicts a critical C-rate above which active particles fracture; this critical C-rate decreases with increasing particle size. We produce an electrochemical shock map, a graphical tool that shows regimes of failure depending on C-rate, particle size, and the material’s inherent fracture toughness K[subscript Ic] . Fracture dynamics are sensitive to the gradient of diffusion-induced stresses at the crack tip; as a consequence, small initial flaws grow unstably and are therefore potentially more damaging than larger initial flaws, which grow stably.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1149/1.3464773
