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Electrochemically Driven Deactivation and Recovery in PrBaCo 2 O 5+ δ Oxygen Electrodes for Reversible Solid Oxide Fuel Cells
Author(s) -
Zhu Lin,
Wei Bo,
Wang Zhihong,
Chen Kongfa,
Zhang Haiwu,
Zhang Yaohui,
Huang Xiqiang,
Lü Zhe
Publication year - 2016
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201600658
Subject(s) - electrochemistry , polarization (electrochemistry) , electrode , oxide , anode , cathodic protection , oxygen evolution , oxygen , materials science , inorganic chemistry , electrochemical cell , chemical engineering , chemistry , metallurgy , organic chemistry , engineering
The understanding of surface chemistry changes on oxygen electrodes is critical for the development of reversible solid oxide fuel cell (RSOFC). Here, we report for the first time that the electrochemical potentials can drastically affect the surface composition and hence the electrochemical activity and stability of PrBaCo 2 O 5+ δ (PBCO) electrodes. Anodic polarization degrades the activity of the PBCO electrode, whereas the cathodic bias could recover its performance. Alternating anodic/cathodic polarization for 180 h confirms this behavior. Microstructure and chemical analysis clearly show that anodic bias leads to the accumulation and segregation of insulating nanosized BaO on the electrode surface, whereas cathodic polarization depletes the surface species. Therefore, a mechanism based on the segregation and incorporation of BaO species under electrochemical potentials is considered to be responsible for the observed deactivation and recovery process, respectively.