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A Modified Electrochemical Model to Account for Mechanical Effects Due to Lithium Intercalation and External Pressure

Zhang, Xiaoxuan; Klinsmann, Markus; Chumakov, Sergei; Li, Xiaobai; Kim, Sun Ung; Metzger, Michael; Besli, Münir M.; Klein, Reinhardt; Linder, Christian; Christensen, Jake

For a battery cell, both the porosity of the electrodes/separator and the transport distance of charged species can evolve due to mechanical deformation arising from either lithium intercalation-induced swelling and contraction of the active particles or externally applied mechanical loading. To describe accurately the coupling between mechanical deformation and the cell's electrochemical response, we extend Newman's DualFoil model to allow variable, non-uniform porosities in both electrodes and the separator, which are dynamically updated based on the electrochemical and mechanical states of the battery cell. In addition, the finite deformation theory from continuum mechanics is used to modify the electrochemical transport equations to account for the change of the charged species transport distance. The proposed coupled electrochemomechanical model is tested with a parameterized commercial cell. Our simulation results confirm that mass conservation is satisfied with the new formulation. We further show that mechanical effects have a significant impact on the cell's electrochemical response at high charge/discharge rates.

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Postprint §
DOI: 10.5445/IR/1000129743
Veröffentlicht am 16.02.2021
DOI: 10.1149/1945-7111/abe16d
Cover der Publikation
Zugehörige Institution(en) am KIT Fakultät für Maschinenbau (MACH)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2021
Sprache Englisch
Identifikator ISSN: 0013-4651, 1945-7111
KITopen-ID: 1000129743
Erschienen in Journal of the Electrochemical Society
Verlag Electrochemical Society
Vorab online veröffentlicht am 29.01.2021
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