Coherency Strain and the Kinetics of Phase Separation in LiFePO [subscript 4]
Name
Bazant_coherency strain.pdf
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1.49 MB
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Adobe PDF
Checksum (MD5)
d5f0f1c56df6bccb6772586596ce9d8f
Author(s)
Cogswell, Daniel A.
Bazant, Martin Z.
Alternative Title
Coherency Strain and the Kinetics of Phase Separation in LiFePO [subscript 4] Nanoparticles
Date Issued
February 2012
Journal
ACS Nano
Publisher
American Chemical Society (ACS)
Citation
Cogswell, Daniel A., and Martin Z. Bazant. “Coherency Strain and the Kinetics of Phase Separation in LiFePO 4.” ACS Nano 6.3 (2012): 2215–2225.
Version
Author's final manuscript
Abstract
A theoretical investigation of the effects of elastic coherency strain on the thermodynamics, kinetics, and morphology of intercalation in single LiFePO4 nanoparticles yields new insights into this important battery material. Anisotropic elastic stiffness and misfit strains lead to the unexpected prediction that low-energy phase boundaries occur along {101} planes, while conflicting reports of phase boundary orientations are resolved by a partial loss of coherency in the [001] direction. Elastic relaxation near surfaces leads to the formation of a striped morphology with a characteristic length scale predicted by the model, yielding an estimate of the interfacial energy. The effects of coherency strain on solubility and galvanostatic discharge are studied with a reaction-limited phase-field model that quantitatively captures the influence of misfit strain, particle size, and temperature on solubility seen in experiments. Coherency strain strongly suppresses phase separation during discharge, which enhances rate capability and extends cycle life. The effects of elevated temperature and the feasibility of nucleation are considered in the context of multiparticle cathodes.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Mathematics
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/10.1021/nn204177u
