Chapter 5. Investigation of Performance Degradation of SOFC using Chromiumcontaining Alloy Interconnects
- Narottam P. Bansal,
- Andrew Wereszczak and
- Edgar Lara-Curzio
Published Online: 26 MAR 2008
Copyright © 2007 The American Ceramics Society
Advances in Solid Oxide Fuel Cells II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 4
How to Cite
Beeaff, D. R., Dinesen, A. and Hendriksen, P. V. (2008) Investigation of Performance Degradation of SOFC using Chromiumcontaining Alloy Interconnects, in Advances in Solid Oxide Fuel Cells II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 4 (eds N. P. Bansal, A. Wereszczak and E. Lara-Curzio), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291337.ch5
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 2006
Print ISBN: 9780470080542
Online ISBN: 9780470291337
The long-term aging of a stack element (fuel cell, current collectors, and interconnect materials) was studied. A pair of tests were made in which one sample contained an interconnect, a high-temperature stainless steel (Crofer 22 APU), treated with an LSMC coating applied to the cathode-side interconnect plate and the other sample containing a similar fuel cell but no steel interconnect. The interconnect-bearing sample was evaluated for thermochemical compatibility of cell components, including interconnect materials, under conditions typical of and/or expected during the lifetime of an installed multi-cell stack. This was done in an attempt to gain an understanding of reactions between sealant and cell materials, the oxidation of interconnect steels, and the formation of non-conducting species at the electrode interfaces. Additionally, it has been proposed by several researchers that the use of chromia-forming stainless steels can lead to the deposition of material at the triple phase boundary (TPB), a process known as chromium poisoning, which leads to a reduction in the electrochemical performance of the cell over time.
Sealing was accomplished using aluminosilicate glass with 30wt. % MgO filler. Long-term degradation of each sample was determined using a current density of 250 mA°Cm-2 using humidified hydrogen as the fuel and air as the oxygen source. Additionally, the stack element was cycled and an investigation into the effect of cathode atmosphere was undertaken to elucidate the aging mechanism.