Lim, Yeji Chong, Jong Heon Guha, Puspendu Lee, Wan-Jae Cho, Inhyeok Oh, Seol Hee Kim, Junseok Yoon, Kyung Joong Son, Ji-Won Lee, Jong-Ho Choi, Sihyuk Kwon, Deok-Hwang Ji, Ho-Il Yang, Sungeun 2025-05-22T06:30:56Z 2025-05-22T06:30:56Z 2025-05-21 2025-06 2050-7488 https://pubs.kist.re.kr/handle/201004/152493 Protonic ceramic fuel cells (PCFCs) are attracting widespread interest due to their high efficiency and relatively low operating temperatures. However, the stability of PCFCs under realistic operating conditions, which include exposure to volatile Cr species and CO2 in the air electrode compartment, has rarely been examined. Here, we test a PCFC composed of BaCe0.4Zr0.4Y0.1Yb0.1O3-delta as the electrolyte and PrBa0.5Sr0.5Co1.5Fe0.5O5+delta as the air electrode, with a metallic interconnect and atmospheric air as an oxidant gas. The complete phase decomposition of the electrolyte and the formation of BaCO3 at the air electrode/electrolyte interface were observed after sudden cell failure within 20 hours of operation. Detailed analyses and control tests confirm the effects of Cr and CO2 species on cell degradation. In contrast, the PBSCF air electrode remains relatively stable. We also report on the effectiveness of applying a thin and dense PBSCF protective barrier layer between the electrolyte and the air electrode, which significantly improves stability under realistic operating conditions. English Royal Society of Chemistry Failure of protonic ceramic fuel cells (PCFCs) under gaseous Cr and CO2 exposure and the introduction of a protective barrier layer for mitigation Article 10.1039/d4ta06672c 1 Journal of Materials Chemistry A, v.13, no.23, pp.17709 - 17719 Journal of Materials Chemistry A 13 23 17709 17719 Y scie scopus 001487329600001 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Chemistry Energy & Fuels Materials Science Article GENERATION STABILITY ELECTROCHEMICAL-CELLS POWER-DENSITY