Optimized Process Parameters for a Reproducible Distribution of Relaxation Times Analysis of Electrochemical Systems
The distribution of relaxation times (DRT) analysis offers a model-free approach for a detailed investigation of electrochemical impedance spectra. Typically, the calculation of the distribution function is an ill-posed problem requiring regularization methods which are strongly parameter-dependent....
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-05-01
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| Series: | Batteries |
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| Online Access: | https://www.mdpi.com/2313-0105/5/2/43 |
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| author | Markus Hahn Stefan Schindler Lisa-Charlotte Triebs Michael A. Danzer |
| author_facet | Markus Hahn Stefan Schindler Lisa-Charlotte Triebs Michael A. Danzer |
| author_sort | Markus Hahn |
| collection | DOAJ |
| description | The distribution of relaxation times (DRT) analysis offers a model-free approach for a detailed investigation of electrochemical impedance spectra. Typically, the calculation of the distribution function is an ill-posed problem requiring regularization methods which are strongly parameter-dependent. Before statements on measurement data can be made, a process parameter study is crucial for analyzing the impact of the individual parameters on the distribution function. The optimal regularization parameter is determined together with the number of discrete time constants. Furthermore, the regularization term is investigated with respect to its mathematical background. It is revealed that the algorithm and its handling of constraints and the optimization function significantly determine the result of the DRT calculation. With optimized parameters, detailed information on the investigated system can be obtained. As an example of a complex impedance spectrum, a commercial Nickel−Manganese−Cobalt−Oxide (NMC) lithium-ion pouch cell is investigated. The DRT allows the investigation of the SOC dependency of the charge transfer reactions, solid electrolyte interphase (SEI) and the solid state diffusion of both anode and cathode. For the quantification of the single polarization contributions, a peak analysis algorithm based on Gaussian distribution curves is presented and applied. |
| first_indexed | 2024-12-23T11:14:35Z |
| format | Article |
| id | doaj.art-ad919f1977be458dae43af6296b53b6d |
| institution | Directory Open Access Journal |
| issn | 2313-0105 |
| language | English |
| last_indexed | 2024-12-23T11:14:35Z |
| publishDate | 2019-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Batteries |
| spelling | doaj.art-ad919f1977be458dae43af6296b53b6d2022-12-21T17:49:15ZengMDPI AGBatteries2313-01052019-05-01524310.3390/batteries5020043batteries5020043Optimized Process Parameters for a Reproducible Distribution of Relaxation Times Analysis of Electrochemical SystemsMarkus Hahn0Stefan Schindler1Lisa-Charlotte Triebs2Michael A. Danzer3Chair of Electrical Energy Systems, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, GermanyHelmholtz-Institute Ulm (HIU), Helmholtzstraße 11, 89081 Ulm, GermanyChair of Electrical Energy Systems, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, GermanyChair of Electrical Energy Systems, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, GermanyThe distribution of relaxation times (DRT) analysis offers a model-free approach for a detailed investigation of electrochemical impedance spectra. Typically, the calculation of the distribution function is an ill-posed problem requiring regularization methods which are strongly parameter-dependent. Before statements on measurement data can be made, a process parameter study is crucial for analyzing the impact of the individual parameters on the distribution function. The optimal regularization parameter is determined together with the number of discrete time constants. Furthermore, the regularization term is investigated with respect to its mathematical background. It is revealed that the algorithm and its handling of constraints and the optimization function significantly determine the result of the DRT calculation. With optimized parameters, detailed information on the investigated system can be obtained. As an example of a complex impedance spectrum, a commercial Nickel−Manganese−Cobalt−Oxide (NMC) lithium-ion pouch cell is investigated. The DRT allows the investigation of the SOC dependency of the charge transfer reactions, solid electrolyte interphase (SEI) and the solid state diffusion of both anode and cathode. For the quantification of the single polarization contributions, a peak analysis algorithm based on Gaussian distribution curves is presented and applied.https://www.mdpi.com/2313-0105/5/2/43electrochemical impedance spectroscopydistribution of relaxation timesTikhonov regularizationLi-ion batterypolarization analysis |
| spellingShingle | Markus Hahn Stefan Schindler Lisa-Charlotte Triebs Michael A. Danzer Optimized Process Parameters for a Reproducible Distribution of Relaxation Times Analysis of Electrochemical Systems Batteries electrochemical impedance spectroscopy distribution of relaxation times Tikhonov regularization Li-ion battery polarization analysis |
| title | Optimized Process Parameters for a Reproducible Distribution of Relaxation Times Analysis of Electrochemical Systems |
| title_full | Optimized Process Parameters for a Reproducible Distribution of Relaxation Times Analysis of Electrochemical Systems |
| title_fullStr | Optimized Process Parameters for a Reproducible Distribution of Relaxation Times Analysis of Electrochemical Systems |
| title_full_unstemmed | Optimized Process Parameters for a Reproducible Distribution of Relaxation Times Analysis of Electrochemical Systems |
| title_short | Optimized Process Parameters for a Reproducible Distribution of Relaxation Times Analysis of Electrochemical Systems |
| title_sort | optimized process parameters for a reproducible distribution of relaxation times analysis of electrochemical systems |
| topic | electrochemical impedance spectroscopy distribution of relaxation times Tikhonov regularization Li-ion battery polarization analysis |
| url | https://www.mdpi.com/2313-0105/5/2/43 |
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