Analysis of Lithium‐Ion Battery State and Degradation via Physicochemical Cell and SEI Modeling. Issue 7 (19th May 2022)

• Record Type: Journal Article
• Authors: Witt, Daniel; Röder, Fridolin; Krewer, Ulrike
• Is Part Of: Batteries & supercaps. Volume 5:Issue 7(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-05-19
• Subjects: cyclization -- impedance -- interfaces -- P2D model -- three-electrode setup; Electrochemistry -- Periodicals; Electrodes -- Periodicals; Electric batteries -- Periodicals; 621.31242
• DOI: 10.1002/batt.202200067
• Languages: English
• ISSNs: 2566-6223

Abstract

Abstract: The quality of lithium‐ion batteries is affected by the formation of the solid electrolyte interphase (SEI). For a better understanding of its effect on cell performance and aging, fast and economically scalable SEI diagnostics are indispensable. Battery models promise to extract hardly accessible interfacial and bulk properties of the SEI from electrochemical impedance spectra and discharge data. The common analysis of only one measurement, often with empirical models, impedes a precise localization of degradation‐related and performance‐limiting processes. This work offers a solution by combining physicochemical SEI and cell modeling for the joint analysis of both measurement types. Our analysis highlights the minor importance of the SEI ionic conductivity for cell performance along with a significant improvement and notable effect of its interfacial properties along aging. Such a detailed understanding of the initial SEI and its evolution over time could enable, e. g., a knowledge‐based optimization of the cell formation process. Abstract : A holistic, yet non‐destructive state estimation of lithium‐ion batteries along aging. A physicochemical cell model with a detailed description of interfacial processes at the SEI allows for the joint analysis of discharge and impedance data. This improves the parameter identifiability and enables a precise localization of performance‐limiting and degradation‐related processes.