Mitigation of Chromium Poisoning Effects in SOFCs By Cathode Compositional Modifications and Interconnect Coatings

Wednesday, 4 October 2017: 10:40
National Harbor 7 (Gaylord National Resort and Convention Center)
Y. Gong, Y. Zhu, Z. Sun, S. N. Basu, U. B. Pal, and S. Gopalan (Boston University)
Solid oxide fuel cells (SOFCs) address critical needs in the energy infrastructure due to their high efficiency, low emisssions and noiseless operation. The intermediate temperature SOFCs(IT-SOFCs) enable the use of metallic interconnect instead of traditional ceramic interconnect. However, chromium poisoning due to transport from metallic interconnect and BOP components is deleterious to cell performance.

To prevent the chromium poisoning, either a new cathode material with a high tolerance of chromium poisoning needs to be deployed, or a protective coating with a high electrical conductivity needs to applied to the interconnect.

In this study, electrolyte-supported baseline half-cell with 8mol% YSZ as the electrolyte and (La0.8Sr0.2)0.95MnO3-δ as the working and counter electrode was fabricated. Its electrochemical characteristics were tested in dry air and 50 mA/cm2 cathodic current in the present of bare chromia-forming interconnect, and an interconnect with a protective coating. Further, to investigate the effect of alternate electrode compositions, new electrodes, e.g. Cr- doped LSM, were employed as the working electrode instead of LSM in the baseline cell, and tested under same conditions.