Experimental Analysis of the Effect of Cathodic CO₂ Supply to Industrial Solid Oxide Fuel Cells

In the SOS-CO 2 cycle, a newly developed hybrid cycle for blue power production, the SOFC cathode is supplied with a CO 2 -rich oxidizing stream, while the anode is fed with a reformate mixture. The performance and the durability of 25 cm 2 Ni-YSZ anode-supported SOFCs are experimentally evaluated under the SOS-CO 2 cycle conditions for 150 h. By testing symmetric cells with LSCF-GDC and LSC-GDC electrodes, the effects of the CO 2 -rich atmosphere on the cathodic material are also investigated. The results show that the loss of performance caused by the cathodic supply of CO 2 is stable in time, but also reversible when switching back to air. The cathodic supply of CO 2 causes both an increase of the polarization resistance and of the ohmic resistance, suggesting a reduction of electronic conductivity compatible with formation of carbonates on the perovskite surface.