Correlating Oxygen Electrode Degradation to Cr Vaporization from Metallic Interconnects in Solid Oxide Cell Stacks
Journal article, 2023

Symmetrical cells consisting of La0.58Sr0.4Co0.2Fe0.8O3-δ (LSCF) oxygen electrodes screen printed on both sides of a Ce0.9Gd0.1O2-δ (CGO) electrolyte were tested at 800 °C while being held close to a piece of Crofer 22 APU alloy. The alloy was either just pre-oxidized or coated with MnCo2O4 and heat treated prior to the exposure test to elucidate the effects of different Cr vaporization rates. Degradation of the symmetrical cells was monitored by electrochemical impedance spectroscopy, and TOF-SIMS, SEM and EDX analysis were used to examine Cr deposition on the electrodes after the exposure. The results show that the degradation rate of the symmetrical cell is directly proportional to the concentration of gaseous Cr(VI)-species, which had been assessed in a previous experiment. The Cr vaporization rate from Crofer 22 APU with a dense MnCo2O4 coating was measured in moisturized air up with up to 40% H2O and found to be invariant with respect to the steam activity. The degradation rate of symmetrical cells was accelerated by humidity in the air, but, noteworthy, this was found also in the absence of a Cr source.

Author

Belma Talic

Sintef Foundation for Scientific and Industrial Research At the Norwegian Institute of Technology

Technical University of Denmark (DTU)

K. Norrman

King Fahd University of Petroleum and Minerals

Tommy Sand

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Jan Froitzheim

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Peter Vang Hendriksen

Technical University of Denmark (DTU)

Journal of the Electrochemical Society

0013-4651 (ISSN) 1945-7111 (eISSN)

Vol. 170 12 124517

Subject Categories

Inorganic Chemistry

Other Chemical Engineering

DOI

10.1149/1945-7111/ad1168

More information

Latest update

1/25/2024