Modeling the Coupled Stress Relaxation and SEI Evolution in Preload-Constrained Lithium-Ion Cells
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Le résumé fourni par la source
This work investigates the role of preload pressure in governing the electro-chemo-mechanical (ECM) behavior of lithium iron phosphate (LFP)/graphite pouch cells during calendar aging. Cells aged at 60 °C under different preload levels were systematically evaluated through in situ monitoring of force evolution and capacity retention. To interpret these behaviors, a coupled model was developed that integrates solid electrolyte interphase (SEI)-induced electrode expansion, viscoelastic relaxation, and stiffness evolution, and it was validated against multi-rate discharge experiments, showing excellent agreement with measured voltage and force responses. The results reveal that higher preload amplifies internal pressure fluctuations, prolongs viscoelastic relaxation, and delays irreversible force recovery, while the overall capacity fade remains largely unaffected. A slight mitigation in capacity loss is observed at high preload, primarily due to suppressed SEI growth resulting from reduced electrode porosity and a decrease in active surface area available for interfacial reactions. Fitting parameters for stiffness correction, relaxation amplitude, and relaxation time exhibited systematic preload dependence. By decoupling irreversible and relaxation forces, the framework enables quantitative analysis of aging-induced pressure accumulation. Overall, this study underscores the critical role of mechanical constraints in long-term battery degradation and demonstrates the predictive capability of the proposed ECM model for guiding preload design in practical modules.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Modeling the Coupled Stress Relaxation and SEI Evolution in Preload-Constrained Lithium-Ion Cells
- Date Crossref
- 26/11/2025
- Éditeur
- MDPI AG
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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Beijing Institute of Technology Energy and Transportation Domain pays non établi dans la noticeUniversité ou école supérieure
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China Automotive Technology and Research Center pays non établi dans la noticeInstitution
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School of Mechanical Engineering National Engineering Research Center of Electric Vehicles pays non établi dans la noticeUniversité ou école supérieure
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Shenzhen Automotive Research Institute pays non établi dans la noticeStructure de recherche
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Ltd. China Automotive New Energy Technology Co. pays non établi dans la noticeEntreprise
Energy and Transportation Domain — Beijing Institute of Technology, China Automotive Technology and Research Center et National Engineering Research Center of Electric Vehicles — School of Mechanical Engineering, avec 2 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.