Oxygen reduction kinetics of high performance BaCo0.4Fe0.4 M 0.1Y0.1O3-δ (M = Mg, Zr) positrode for protonic ceramic fuel cells

Abstract Protonic ceramic fuel cells (PCFCs) should exhibit high performance at intermediate temperatures in the range of 400–600 °C. To reduce the operating temperature, more active air electrodes (positrodes) are needed. In the present work, BaCo0.4Fe0.4Mg0.1Y0.1O3-δ (BCFMY) is investigated as a p...

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Main Authors: Hirofumi Sumi, Konosuke Watanabe, Aman Sharma, Masaya Fujioka, Hiroyuki Shimada, Yasunobu Mizutani, Md Saiful Alam, Isao Kagomiya
Format: Article
Language:English
Published: Nature Portfolio 2025-03-01
Series:Communications Chemistry
Online Access:https://doi.org/10.1038/s42004-025-01468-4
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Summary:Abstract Protonic ceramic fuel cells (PCFCs) should exhibit high performance at intermediate temperatures in the range of 400–600 °C. To reduce the operating temperature, more active air electrodes (positrodes) are needed. In the present work, BaCo0.4Fe0.4Mg0.1Y0.1O3-δ (BCFMY) is investigated as a positrode material for application in PCFCs as well as solid oxide fuel cells (SOFCs). For SOFCs, the polarization resistance ascribed to the oxygen reduction reaction is proportional to p O2 −1/4 (p O2: oxygen partial pressure), suggesting that the rate-determining process is the charge transfer on the mixed ionic-electronic conductors. For PCFCs, this polarization resistance is proportional to p O2 − 1/2, suggesting that the rate-determining process is the oxygen dissociation. The total polarization resistance for the PCFCs using the BCFMY positrode is 0.066 Ωcm2 at 600 °C, lower than that using the BaCo0.4Fe0.4Zr0.1Y0.1O3-δ (BCFZY) positrode. The higher oxygen nonstoichiometry of BCFMY promotes the oxygen dissociation process on the PCFC positrode surface.
ISSN:2399-3669