Experimental investigation of segmented SOECs: Locally-resolved impedance and degradation characteristics. (1st February 2023)

• Record Type: Journal Article
• Authors: Königshofer, Benjamin; Höber, Michael; Menzler, Norbert H.; Schröttner, Hartmuth; Hochenauer, Christoph; Subotić, Vanja
• Is Part Of: International journal of hydrogen energy. Volume 48:Number 10(2023)
• Page Start: 3740
• Page End: 3758
• Publication Date: 2023-02-01
• Subjects: Solid oxide electrolysis cell (SOEC) -- Segmented -- Locally-resolved -- Electrochemical analysis -- Distribution of relaxation times (DRT); Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2022.10.265
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: High temperature solid oxide electrolysis cells (SOEC) provide an innovative solution for direct conversion of steam and electricity to hydrogen with the additional capability of adding CO2 to produce syngas. However, specific operating conditions can have a negative impact on the performance and lifetime of SOECs. In this context, the distributions of operational parameters such as gas species, temperature and current density within the cell structure influence local transport processes and reaction kinetics and can lead to locally different electrochemical potentials and thus degradation phenomena. This study focuses on experimental investigations of steam-electrode supported SOECs with segmented air electrodes with the main objective to measure EIS and thus identify locally-resolved impedance and degradation characteristics caused by different operating conditions in steam and co-electrolysis mode. Thereby, significant correlations between operating conditions, local effects, electrode processes and degradation mechanisms were observed and analyzed in detail using EIS, DRT and SEM. Highlights: Locally resolved impedance and degradation characteristics of SOECs. Experimental results of SOECs performance under different operating conditions. Detailed insight into electrode processes and mechanisms via DRT and SEM analysis.