A comparative investigation of chromium deposition at air electrodes of solid oxide fuel cells

Degradation of (La0.6Sr0.4)0.95(Co0.2Fe0.8)O3−δ Solid Oxide Fuel Cell Cathodes at the Nanometer Scale and below

“…The chemical reaction between Cr species and the cathode material has been proposed to be a main poisoning mechanism in the literature 4,[8][9] and the objective of the work is to develop both the methodology and a fundamental understanding of the poisoning mechanisms by investigating the correlation between the material degradation and the intrinsic Cr/LSCF interaction modes operating at the nanometer scale and below. As a result, the poisoning strategy adopted in this work was impregnating the LSCF 6428 cathode with a Cr stock solution of 1.22 mol l -1 as employed in a previous study 5 , in order to allow for a direct reaction between Cr species and LSCF that could lead to a rapid and significant poisoning effect.…”

“…Studies on the mechanisms of Cr deposition have proposed that the process is a chemical reaction between Cr (VI) with active elements in the electrode material such as Sr in LSCF [8][9] , more than an electrochemical reduction process in competition with O2 reduction [10][11] . The Cr rich phases, in the case of LSCF, have been suggested to be mainly SrCrO4 with a minor Cr2O3 impurity from bulk analysis using X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) 8,[12][13] .…”

Cr-tolerance of the IT-SOFC La(Ni,Fe)03 material

“…However, Cr-poisoning, caused by evaporating Cr from such metallic interconnects, has been identified as very detrimental for the functioning of the state-of-the-art (SoA) SOFC cathodes. This resulted in performance degradation [9][10][11][12][13], impeding the required 40,000 hours operation of the IT-SOFC system.…”

“…Corrugated Fe-Cralloyed metallic interconnect fulfills all these stringent requirements. [18] A drawback of the use of the ferritic stainless steels is the Cr evaporation from Fe-Cr interconnects resulting in Cr-poisoning of the SOFC cathodes, which leads to a serious performance deterioration (loss of the electrical power output P el ) [4,6,[9][10][11][12][13]]. …”

“…This leads to performance deterioration over time [9][10][11][12][13][23][24][25][26]. However, so far no consensus has been reached in literature re-1.5 Cr-poisoning of SOFC cathodes garding the nature of Cr deposition and the interaction with the cathode materials.…”