Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7725413 | Journal of Power Sources | 2018 | 5 Pages |
Abstract
The present work aims to quantify the influence of typical interconnect coatings used for solid oxide fuel cells (SOFC) on area specific resistance (ASR). To quantify the effect of the coating, the dependency of coating thickness on the ASR is examined on Crofer 22 APU at 600â¯Â°C. Three different Co coating thicknesses are investigated, 600â¯nm, 1500â¯nm, and 3000â¯nm. Except for the reference samples, the material is pre-oxidized prior to coating to mitigate the outward diffusion of iron and consequent formation of poorly conducting (Co,Fe)3O4 spinel. Exposures are carried out at 600â¯Â°C in stagnant laboratory air for 500â¯h and subsequent ASR measurements are performed. Additionally the microstructure is investigated with scanning electron microscopy (SEM). On all pre-oxidized samples, a homogenous dense Co3O4 top layer is observed beneath which a thin layer of Cr2O3 is present. As the ASR values range between 7 and 12â¯mΩcm2 for all pre-oxidized samples, even though different Co3O4 thicknesses are observed, the results strongly suggest that for most applicable cases the impact of the coating on ASR is negligible and the main contributor is Cr2O3.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Claudia Goebel, Alexander G. Fefekos, Jan-Erik Svensson, Jan Froitzheim,