• Kiviaho, Jari
• Bexell, Ulf
• Holmström, Stefan
• Rautanen, Markus
• Himanen, Olli

Abstract

Metallic interconnect plate materials used in solid oxidefuel cells must withstand both oxidizing and reducingconditions occurring on cathode and anode side of thecell, respectively. Ferritic steels with high chromiumcontent are considered only economically and technicallyviable alternative. For this application, the formedchromium oxide scale is sufficiently protective andconducting. However, chromium evaporation from theinterconnect materials causes cell degradation. Tominimize this effect, and still have a sufficientlyconductive oxide, a chromium barrier layer is needed, e.gby coating the material with a metal precursor that isoxidised. In this work, a new promising interconnectmaterial Sanergy HT (AB Sandvik Materials Technology ,Sweden) and the widely used Crofer 22 APU (ThyssenKruppAG, Germany) were studied.Tested materials were uncoated Sanergy HT, uncoatedCrofer 22 APU, and also Co-coated Sanergy HT. Thesematerials were tested ex-situ with chromium evaporationmeasurements under oxidizing conditions, mass gainmeasurements under both oxidizing and reducingconditions, and also contact resistance measurements.Materials were also tested under real operatingconditions in single repeating units. After each test thesamples were analyzed by SEM/EDX on polished and FIB cutcross sections. Complementary analyses were done withXRD. Results of these tests will be published in theposter presentation.

Topics

• impedance spectroscopy
• chromium
• scanning electron microscopy
• steel
• Energy-dispersive X-ray spectroscopy
• evaporation