Sai Dinesh Gelam1, Sahithi Maddipatla1, Carmen Chicone2, and Michael Pecht1
1Center for Advanced Life Cycle Engineering (CALCE), University of Maryland, College Park, MD, USA
2Department of Mathematics, University of Missouri, Columbia, MO, USA
For more information about this article and related research, please contact Prof. Michael Pecht.
Abstract:
During charge-discharge cycling in cylindrical lithium-ion batteries, lithiation and delithiation within the electrodes cause anisotropic expansion and contraction, generating mechanical stresses that can contribute to degradation mechanisms such as core collapse. Using finite element modeling of a cylindrical jellyroll cell and simulation of frictional interaction between electrode layers and intercalation volume changes, this study shows that the stress field transitions from tensile hoop stress near the cell's cylindrical casing to compressive hoop stress near the core, which can cause core collapse in that region. In addition, the analysis reveals that in the middle electrode layers, the anode develops outer tensile and inner compressive stresses, while the cathode displays the inverse pattern due to frictional stress transfer between adjacent electrodes. Frictional parametric analysis in this study shows that reducing inter-layer friction lowers the magnitude of peak compressive stress and shifts it outward from the center of the jelly roll, suggesting that tailoring the friction between the jelly roll layers can mitigate core collapse.
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