Selective in situ phase segregation enabling efficient and stable protonic ceramic fuel cell cathode performance
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Date
2025-06-09
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley
Abstract
Efficient and reliable protonic ceramic fuel cells (PCFCs) necessitate the development of active and durable cathode materials to accelerate the sluggish oxygen reduction reaction (ORR). The most promising PCFC cathode candidates are perovskite‐type structured oxides with mixed oxygen ion, proton, and hole conductivity. However, mixed conductivity often requires materials with alkaline earth elements and the inclusion of these elements in the cathode structure leads to severe degradation in the presence of even small trace amounts of CO2 in air. Herein, a new approach is presented to address this challenge by inducing selective in situ phase segregation to engineer the cathode surface and bulk separately. This selective phase segregation is achieved via targeted control of the size mismatch of cations in the perovskite‐type structure, enhancing charge transfer in the bulk while improving CO2 resistance at the surface. By co‐incorporating smaller Li+ and larger K+ into the model BaCo0.4Fe0.4Zr0.1Y0.1O3−δ cathode material, it is shown that Li+ segregates to the surface, protecting it from CO2 poisoning, while K+ remains in the bulk and accelerates proton transport. Consequently, this in situ restructured cathode can boost the PCFC power output by 30% and improve its CO2 tolerance fivefold in the presence of CO2 at 600 °C. © 2025 The Author(s). Small published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution-Non Commercial Licence
Description
Keywords
In-situ processing, Cathodes, Fuel cells, Oxygen ions, Carbon dioxide, Proton transport, Poisoning, Iron, Temperature range, Electrolytes, Water, Barium
Citation
Feng, D., Peterson, V. K., Zhu, T., Lin, R., D'Angelo, A. M., Appadoo, D., Tian, X., Du, X., Zhu, Z., & Li, M. (2025). Selective in situ phase segregation enabling efficient and stable protonic ceramic fuel cell cathode performance. Small, 21(31), 2411223. doi:10.1002/smll.202411223