AI Na
(Fujian College Association Instrumental Analysis Center, Fuzhou University, Fuzhou, Fujian 350108, China)

Abstract: One of the key degradation mechanisms of solid oxide fuel cells (SOFC) stacks is the serious performance loss of the cathodes, owing to the attack by the gaseous Cr species generated from the Fe–Cr alloy interconnect. BaCeO₃ (BCO) nanoparticles are decorated on La_0.6Sr_0.4Co_0.2Fe_0.8O_3–δ(LSCF) cathode, leading to an effective improvement in electrocatalytic activity and operating stability of the cathode under accelerated Cr poisoning conditions. The BCO nanoparticles not only suppressed the surface segregation of Sr, but also preferentially reacted with Cr₂O₃ on surface of the interconnect, forming a conductive BaCrO₄ buffer layer on the electrode surface. The BaCrO₄ layer separated LSCF and interconnect, to that the formation of SrCrO₄ is eliminated. The synergistic effects of the two factors remarkably enhanced the chromium-tolerance of BCO-LSCF cathodes.
Key words: solid oxide fuel cells; Cr poisoning; LSCF; Sr surface segregation; BaCeO₃ infiltration