Quantifying Volume Change in Battery Electrode Microstructures

Abstract

A three-dimensional microstructure-based modeling method (3DMS) is developed [1, 2] to predict the mechanical behaviors of porous electrode that includes both active material (AM) and binders inside lithium-ion battery during compression, reversible expansion (intercalation dependent), and irreversible expansion (aging dependent). The geometry of both AM and binder is generated stochastically to create microstructures by using a modified MATBOX opensource program with our in-house code. The advanced technique of volume element generation is also established to overcome the interfacial error due to complexity of binder distribution. The Finite Element Analysis (FEA) based solid-stress model is applied to predict local mechanical activities including stress-strain relationship and microstructure evolution during compression, intercalation, and aging.The predictions of behavior in the porous electrode under compressive loads will be presented and the insights into the microstructure deformation will be discussed. Further, the analysis results will be validated using experimental testing results acquired at various length scales. This work can be used for the model-based FEA platform to predict the impact of volume change under charge/discharge cycles, volume change of a jelly-roll during formation, and the response of the active material in typical pouch cells during battery module assembly.The predictions of reversible expansion in the porous electrode during cycling will be presented and the insights into the microstructure expansion as compared to continuum porous electrode models from previous work [3-8] will be discussed.Finally, insights into the linkage between irreversible volume expansion in the porous electrode during aging cycling will be discussed and compared to testing acquired for automotive-relevant large format [9] pouch cells.References J. S. Lopata, T. R. Garrick, F. Wang, H. Zhang, Y. Zeng and S. Shimpalee, ECSarXiv (2022).J. S. Lopata, T. R. Garrick, F. Wang, H. Zhang, Y. Zeng and S. Shimpalee, J Electrochem Soc, 170, 020530 (2023).D. J. Pereira, J. W. Weidner and T. R. Garrick, J Electrochem Soc, 166, A1251 (2019).D. J. Pereira, M. A. Fernandez, K. C. Streng, X. X. Hou, X. Gao, J. W. Weidner and T. R. Garrick, J Electrochem Soc, 167, 080515 (2020).D. J. Pereira, A. M. Aleman, J. W. Weidner and T. R. Garrick, J Electrochem Soc, 169, 020577 (2022).T. R. Garrick, K. Kanneganti, X. Y. Huang and J. W. Weidner, J Electrochem Soc, 161, E3297 (2014).T. R. Garrick, K. Higa, S.-L. Wu, Y. Dai, X. Huang, V. Srinivasan and J. W. Weidner, J Electrochem Soc, 164, E3592 (2017).T. R. Garrick, X. Huang, V. Srinivasan and J. W. Weidner, J Electrochem Soc, 164, E3552 (2017).T. R. Garrick and J. W. Weidner, in Electrochemical Society Meeting s 233, p. 1345 (2018).