Inhibiting chromium evaporation and oxide scale growth on SOFC metallic interconnects by nano coatings
Conference contribution, 2014

High chromium ferritic steel is today the most commonly considered material for SOFC interconnectors due to many desirable properties, such as matching thermal expansion coefficient with other cell components but most importantly better machinability and price compared to ceramic alternatives. Yet there are some obstacles that need to be addressed before long term stability of a ferritic steel interconnector based fuel cell stack can be realized. First of all the electrical conductivity needs to remain high throughout the fuel cell stack operating life time and thus the formed oxide layers need to be electrically conductive and thin. Secondly, volatilization of chromium from the oxide scale of metallic interconnects causes rapid degradation due cathode poisoning. In the current study both oxidation and chromium evaporation of ferritic steel substrates are investigated in controlled atmospheres that simulates the environments of an operating SOFC stack. Samples coated with nanometer scale dual coatings of Co and Ce were tested. The dual coating substantially increased the performance of the ferritic substrates by i) significantly reducing oxidation rate, ii) increasing scale adherence and iii) diminishing chromium evaporation by 90 % via the formation of a Co-Mn-spinel cap layer.

Author

Patrik Alnegren

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Rakshith Nugehalli Sachitanand

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Jan Gustav Grolig

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Hannes Falk Windisch

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Mohammad Sattari

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Jan-Erik Svensson

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Jan Froitzheim

Chalmers, Chemical and Biological Engineering, Environmental Inorganic Chemistry

Roceedings of 20th World Hydrogen Energy Conference, WHEC 2014, 15-29 June 2014 KDJ Convention CenterGwangju; South Korea,

Vol. 1 423-426

Subject Categories

Inorganic Chemistry

ISBN

978-000000000-2

More information

Created

10/7/2017