Sulfur Poisoning on La0.6Sr0.4Co0.2Fe0.8O3 Cathode for SOFCs

Abstract

The effect of SO 2 content in air on degradation of a La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 (LSCF6428) cathode for solid oxide fuel cells was investigated at T = 1073 K for 24 h by setting the concentration of SO 2 to 0.1, 1, 10, and 100 ppm. The degradation of the LSCF6428 cathode became more significant with increasing SO 2 concentrations due to the increase of cathode polarization resistance. The SrSO 4 formation was confirmed after exposing to SO 2 from 0.1 to 100 ppm and became even harsh with increasing SO 2 concentrations. The reaction sequence can be interpreted from thermodynamic considerations using chemical potential diagrams and chemical equilibrium calculations.

Sulfur Deposition and Poisoning of La0.6Sr0.4Co0.2Fe0.8O3-δCathode Materials of Solid Oxide Fuel Cells

“…However, a major issue over a 5 year life-time of a SOFC system is the gradual degradation and deactivation of the cathodes by contaminants such as chromium, sulfur and boron which can be either in the air stream or from the volatile species of cell components, such as metallic interconnect, sealant and manifold. [13][14][15][16] One possible source of sulfur contamination is the presence of a trace amount of SOx in air, which could be accumulated by reacting with the cathode in the vicinity of the air entrance of cells. For example, one of the major challenges for the direct use of hydrocarbon fuels in SOFCs is the poisoning of Ni-based anodes by sulfur existed as impurities in readily available hydrocarbon fuels.…”

Thermodynamic stability of sulfide electrolyte/oxide electrode interface in solid-state lithium batteries

“…State [40,41]. A numerical value of −80.75 is obtained as the logarithmic equilibrium lithium activity, log a(Li), for the LiCoO 2 -CoO 2 two phase interface, which corresponds to 4.78 V vs. Li (16.9 in log a(Li) corresponds to 1 V in electrical potential).…”

Degradation of LSCF Cathode Induced by SO2 in Air

“…Degradation of LSCF cathodes is induced by impurities in air. One of the most recognized impurities is sulfur dioxide (SO 2 ) [1][2][3][4][5][6][7][8][9][10]. Our group has investigated the degradation behavior of LSCF cathodes induced by SO 2 containing air.…”