Influence of concentration-dependent material properties on the fracture and debonding of electrode particles with core-shell structure

Fuente: arXiv
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Autores principales: Tu, Y., Wu, B., Ai, W., Martínez-Pañeda, E.
Formato: Preprint
Publicado: 2024
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author Tu, Y.
Wu, B.
Ai, W.
Martínez-Pañeda, E.
author_facet Tu, Y.
Wu, B.
Ai, W.
Martínez-Pañeda, E.
contents Core-shell electrode particle designs offer a route to improved lithium-ion battery performance. However, they are susceptible to mechanical damage such as fracture and debonding, which can significantly reduce their lifetime. Using a coupled finite element model, we explore the impacts of diffusion-induced stresses on the failure mechanisms of an exemplar system with an NMC811 core and an NMC111 shell. In particular, we systematically compare the implications of assuming constant material properties against using Li concentration-dependent diffusion coefficient and partial molar volume. With constant material properties, our results show that smaller cores with thinner shells avoid debonding and fracture regimes. When factoring in a concentration-dependent partial molar volume, the maximum values of tensile hoop stress in the shell are found to be significantly lower than those predicted with constant properties, reducing the likelihood of fracture. Furthermore, with a concentration-dependent diffusion coefficient, significant barriers to full electrode utilisation are observed due to reduced lithium mobility at high states of lithiation. This provides a possible explanation for the reduced accessible capacity observed in experiments. Shell thickness is found to be the dominant factor in precluding structural integrity once the concentration dependency is accounted for. These findings shed new light on the performance and effective design of core-shell electrode particles.
format Preprint
id arxiv_https___arxiv_org_abs_2403_13409
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Influence of concentration-dependent material properties on the fracture and debonding of electrode particles with core-shell structure
Tu, Y.
Wu, B.
Ai, W.
Martínez-Pañeda, E.
Chemical Physics
Materials Science
Computational Engineering, Finance, and Science
Applied Physics
Core-shell electrode particle designs offer a route to improved lithium-ion battery performance. However, they are susceptible to mechanical damage such as fracture and debonding, which can significantly reduce their lifetime. Using a coupled finite element model, we explore the impacts of diffusion-induced stresses on the failure mechanisms of an exemplar system with an NMC811 core and an NMC111 shell. In particular, we systematically compare the implications of assuming constant material properties against using Li concentration-dependent diffusion coefficient and partial molar volume. With constant material properties, our results show that smaller cores with thinner shells avoid debonding and fracture regimes. When factoring in a concentration-dependent partial molar volume, the maximum values of tensile hoop stress in the shell are found to be significantly lower than those predicted with constant properties, reducing the likelihood of fracture. Furthermore, with a concentration-dependent diffusion coefficient, significant barriers to full electrode utilisation are observed due to reduced lithium mobility at high states of lithiation. This provides a possible explanation for the reduced accessible capacity observed in experiments. Shell thickness is found to be the dominant factor in precluding structural integrity once the concentration dependency is accounted for. These findings shed new light on the performance and effective design of core-shell electrode particles.
title Influence of concentration-dependent material properties on the fracture and debonding of electrode particles with core-shell structure
topic Chemical Physics
Materials Science
Computational Engineering, Finance, and Science
Applied Physics
url https://arxiv.org/abs/2403.13409