From Ideal to Stack-like Contacting of an SOC

• Published in: ECS transactions Vol. 111; no. 6; pp. 533 - 546
• Main Authors: Grosselindemann, Cedric, Esau, Daniel, Dorn, Marvin, Bauer, Frank Manuel, Wissmeier, Lena, Weber, Andre
• Format: Journal Article
• Language: English
• Published: The Electrochemical Society, Inc 19.05.2023
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/11106.0533ecst

The performance of an SOC depends on the testing environment. Regarding single cell tests with ideal contacting (gold and nickel meshes) and inert flow fields (Al 2 O 3 ), the performance is limited by the intrinsic losses in the cell as contact losses and any poisoning effects are minimized. In an SOC-stack exhibiting metallic interconnectors, the performance is furthermore affected by contact resistances and limitations in gas supply. In this contribution single cell testing is extended to a stack-like contacting applying three different metallic interconnectors (Crofer 22 APU, ASTM 441 and UNS S44330) with and without a cerium-cobalt PVD-coating. Cell performance and losses are analyzed by IV-characteristics, impedance spectroscopy and DRT analysis. For all uncoated interconnectors, significant performance losses due to increased contact losses and air electrode polarization were observed. With the CeCo-coating losses could be drastically reduced leading to a cell performance close to the ideal case for all three steel grades.