In this section
@article{Tu:2024:10.1149/ma2024-012488mtgabs,
author = {Tu, Y and Wu, B and Ai, W and Martinez-Paneda, E},
doi = {10.1149/ma2024-012488mtgabs},
journal = {ECS Meeting Abstracts},
pages = {488--488},
title = {Mechanical Failure of Core-Shell Cathode Particles: The Effects of Concentration-Dependent Material Properties and Phase Field Fracture Modelling},
url = {http://dx.doi.org/10.1149/ma2024-012488mtgabs},
volume = {MA2024-01},
year = {2024}
}
TY - JOUR
AB - <jats:p> The use of core-shell cathode particles in lithium-ion batteries is an attractive approach to enhancing energy density whilst retaining lifetime, through reducing undesired reactions at the electrode-electrolyte interface and limiting the volume change of the electrode particles. However, mechanical failure through the fracture and debonding of the core-shell interface is a major challenge. In this work, we employ a coupled finite-element model to predict and mitigate the mechanical failure of core-shell cathode structures, taking as example a particle of NMC811 (core) coated with NMC111 (shell). In particular, we focus on two aspects:</jats:p> <jats:p>The first one involves the assumptions of material properties as inputs of the model. The material properties are often considered constant by battery modelling researchers, yet these parameters can vary significantly during charge/discharge. For example, experiments have unveiled a three-orders-of-magnitude drop in the diffusion coefficient of NMC materials during discharge [1]. Here, we incorporate material properties obtained from experimental data, including concentration-dependent diffusion coefficient obtained from GITT measurement and partial molar volume derived from in situ X-ray diffraction data. Our results indicate that when assuming a concentration-dependent partial molar volume, the maximum values of tensile hoop stress in the shell are nearly three times lower than those predicted with constant average properties, diminishing the likelihood of fracture.</jats:p> <jats:p>When accounting for concentration-dependent diffusion coefficient, large concentration gradient is observed near the outer surface of the core due to reduced lithium mobility at high states of lithiation, hindering full electrode capacity utilisation. The significant concentration gradient and capacity underutilisation align with direct observations from experiments [2]
AU - Tu,Y
AU - Wu,B
AU - Ai,W
AU - Martinez-Paneda,E
DO - 10.1149/ma2024-012488mtgabs
EP - 488
PY - 2024///
SP - 488
TI - Mechanical Failure of Core-Shell Cathode Particles: The Effects of Concentration-Dependent Material Properties and Phase Field Fracture Modelling
T2 - ECS Meeting Abstracts
UR - http://dx.doi.org/10.1149/ma2024-012488mtgabs
VL - MA2024-01
ER -
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