Regenerative solid oxide cells can operate in either a fuel cell mode or an electrolysis mode as needed. Recently, regenerative proton-conducting solid oxide cells (R-PSOCs) have attracted considerable attention due to their potential for efficient and low-cost power and fuel co-generation.^{1, 2} However, the performance and durability of R-PSOCs are still limited by the lack of highly active and robust air electrode/catalyst materials for dual-mode operation. In this presentation, we will highlight the critical scientific challenges facing the development of efficient and durable air electrode/catalyst materials for R-PSOCs as well as the strategies for dramatically enhancing electrode activity and durability. We will then present our recent progress in the development of new air electrodes ^{3, 4} as well as the mechanism of electrode reactions and degradation, as revealed by a combination of modeling, simulation, and in situ/operando characterization of electrode processes ^{5, 6}. Catalytic activity, evolution of the surface chemistry, and contaminant (e.g., water and chromium) tolerance of both the conventional La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ (LSCF) electrode and the newly developed PrBa_0.8Ca_0.2Co₂O_5+δ–BaCoO_3−δ (PBCC–BCO) electrode will be discussed. Performance, long-term stability, and degradation mechanism of R-PSOCs using LSCF and PBCC–BCO air electrodes will be reported. We will further introduce our recent progress in the development of highly active and durable catalyst coatings for the air electrodes with significantly enhanced performance and durability under typical operating conditions with the presence of contaminants.

Reference:

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