Artificial generation of representative single Li-ion electrode particle architectures from microscopy data

Orkun Furat,David Diercks,Kandler Smith,Volker Schmidt,Francois Usseglio-Viretta,Donal P Finegan,Lukas Petrich

doi:10.1038/s41524-021-00567-9

Orkun Furat, David Diercks + Show 5 more

Open Access

https://doi.org/10.1038/s41524-021-00567-9

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Abstract

Accurately capturing the architecture of single lithium-ion electrode particles is necessary for understanding their performance limitations and degradation mechanisms through multi-physics modeling. Information is drawn from multimodal microscopy techniques to artificially generate LiNi0.5Mn0.3Co0.2O2 particles with full sub-particle grain detail. Statistical representations of particle architectures are derived from X-ray nano-computed tomography data supporting an ‘outer shell’ model, and sub-particle grain representations are derived from focused-ion beam electron backscatter diffraction data supporting a ‘grain’ model. A random field model used to characterize and generate the outer shells, and a random tessellation model used to characterize and generate grain architectures, are combined to form a multi-scale model for the generation of virtual electrode particles with full-grain detail. This work demonstrates the possibility of generating representative single electrode particle architectures for modeling and characterization that can guide synthesis approaches of particle architectures with enhanced performance.

Highlights

To enable widespread electrification of passenger cars, lithium(Li)ion batteries must achieve high-energy densities, high rates, and long cycle lives[1]
The stochastic models are described from which random outer particle shells and random grain architectures can be generated, respectively
Both models are combined into a multiscale model for the outer shell and grain architecture of NMC

Summary

Introduction

To enable widespread electrification of passenger cars, lithium(Li)ion batteries must achieve high-energy densities, high rates, and long cycle lives[1]. The most widely used positive electrode in Li-ion batteries consists of LiNi1−x−yMnyCoxO2 (NMC) particles of various stoichiometries. The majority of NMC electrodes consist of polycrystalline particles where each grain within the particle facilitates transport of Li along 2D planes. Anisotropic expansion or contraction of the layered crystal structure of NMC occurs when the grains lithiate or delithiate. This expansion and contraction can lead to sub-particle mechanical strains[6,7,8], particle cracking[9,10], and accelerated capacity fade[7,8]. The morphology and orientation of grains have been shown to greatly affect the rate capability of the electrode, where particles with grains oriented with exposed edge facets that transport Li radially inward, display superior rate performance, and longer life[11,12,13]

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