Electrochemical impedance spectroscopy (EIS) is a powerful diagnostic tool for analyzing solid oxide electrolysis cells (SOECs). While EIS measurements on single-cell level are commonplace, implementation of EIS on stack level remains limited. Here, we report a framework for analyzing stack-level EIS data. Analysis of the collected impedance data comprises Kramers-Kronig transformations, distribution of relaxation times (DRT), and analysis of the difference of impedance spectra (ADIS). The DRT and ADIS results were used as input parameters for the complex non-linear least squares (CNLS) fitting procedure and the validity of the chosen equivalent circuit model was confirmed by reconstruction of Nyquist-, Bode-, DRT-plots, and the individual electrochemical contributions of the fitted data. The developed framework was successfully implemented on a commercial 75-cell SOEC stack (TSP-1) from Haldor Topsoe.
|Number of pages||15|
|Publication status||Published - 2021|
|Event||17th International Symposium on Solid Oxide Fuel Cells - Stockholm, Sweden|
Duration: 18 Jul 2021 → 23 Jul 2021
Conference number: 17
|Conference||17th International Symposium on Solid Oxide Fuel Cells|
|Period||18/07/2021 → 23/07/2021|