Operando determination of lithium-ion cell temperature based on electrochemical impedance features

Titelangaben

Hackmann, Tobias ; Esser, Sebastian ; Danzer, Michael A.:
Operando determination of lithium-ion cell temperature based on electrochemical impedance features.
In: Journal of Power Sources. Bd. 615 (2024) . - 235036.
ISSN 0378-7753
DOI: https://doi.org/10.1016/j.jpowsour.2024.235036

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Abstract

Electrochemical impedance spectroscopy is applied to lithium-ion batteries during operation with the general purpose of an operando characterization and specifically for battery state estimation. For the first time, 143 features of the measured impedance spectra are extracted and form the data basis that contains information on the cell states and their complex dependencies. Spectra are collected in stationary and transient conditions at varying temperatures, states of charge and states of health. A novel method is presented that enables an evaluation of features under these multidimensional dependencies. By a rigorous classification, interpretation and discussion an enhanced understanding of state dependencies and sensitivities towards operating conditions is reached. Ultimately, the selected impedance features are utilized for an operando state estimation and especially the determination of the cell internal temperature. A detailed literature review of impedance-based temperature estimation is provided. Results are presented for a Molicel INR-21700-P42A and a Samsung INR-21700-50E with an accuracy of 2 K for a wide range of operating conditions and even with increased aging.