Failure of protonic ceramic fuel cells (PCFCs) under gaseous Cr and CO 2 exposure and the introduction of a protective barrier layer for mitigation

Cr species and CO 2 rapidly degrade the PCFC electrolyte BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3− δ , while the air electrode PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+ δ remains stable. A thin PBSCF layer enhances air electrode/electrolyte interface stability.