Volume 45: Energy Transitions toward Carbon Neutrality: Part VIII

3D Reconstruction and Quantitative Characterization of a NCM523 Cathode for Microstructure-Based Modeling Jixiang Cai, Xuezhe Wei, Jiangong Zhu, Bo Jiang, Xueyuan Wang, Jinding Liang, Haifeng Dai

Abstract

Most mechanism-based battery models rely on the pseudo-two-dimensional (P2D) model, which simplifies electrode particles as homogenously distributed spheres, lacking the capability to represent the intricate microstructure. To develop a modeling approach aligned with authentic electrode microstructure, a mesoscopic image dataset of a NCM523 cathode is obtained through FIB-SEM, and, subsequently, the 3D microstructure model is reconstructed. Within this volume, we utilize thresholding methods to segment the active material (AM), the carbon-binder domain (CBD), and the pores. Furthermore, critical microstructural parameters, i.e., volume fractions, layer-by-layer area fractions of the three phases, equivalent diameter and sphericity distributions of AM particles, are quantified, Additionally, the pores phase undergoes connectivity analysis, and the tortuosity is also calculated. The results show significant heterogeneity in the electrode microstructure. In particular, only 33% of the particles can be regarded as spheres. This work demonstrates the limitations of the P2D model and can be used as the basis for microstructure-based battery modeling.

Keywords lithium-ion battery, electrode microstructure, heterogeneity distribution, microstructural parameters, microstructure-based battery modeling