Abstract
This paper develops a three-dimensional, transient, chemo-mechanical model that predicts the performance of single secondary particle Li-ion battery cathodes. The secondary particles are composed of numerous (approximately 60) randomly oriented single-crystal primary particles. The model incorporates concentration-dependent and anisotropic material properties. As much as possible, electrochemical, transport, and structural properties for crystalline NMC811 (Li x Ni0.8Mn0.1Co0.1O2) are taken from prior publications. Weak Van der Waals bonding between primary particles is modeled empirically using a spring analogy, which enables local primary-particle separations (disintegration) and subsequent reattachments. The model fully couples Li diffusion and the mechanical response. Results include predictions of local Li-concentrations and stresses. High stresses are found near grain boundaries, especially when the lattice orientations are greatly misaligned. Particle separations are characterized in terms of a damage parameter. The model is used to predict the effects of design and operating conditions, including charge/discharge rates, cycling scenarios, and particle sizes.
Original language | American English |
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Article number | 080511 |
Number of pages | 14 |
Journal | Journal of the Electrochemical Society |
Volume | 168 |
Issue number | 8 |
DOIs | |
State | Published - 2021 |
Bibliographical note
Publisher Copyright:© 2021 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.
NREL Publication Number
- NREL/JA-5700-79856
Keywords
- diffusion-induced stress
- Li-ion battery
- NMC electrode particle
- particle disintegration