Effects of surface chemistry and microstructure of electrolyte on oxygen reduction kinetics of solid oxide fuel cells

JOURNAL OF POWER SOURCES

卷:295

Article

Park, Joong Sun^1,2  An, Jihwan^2,3  Lee, Min Hwan⁴  Prinz, Fritz B.^2,5  Lee, Wonyoung^2,6 

[1] Argonne Natl Lab, Chem Sci & Engn Div, Argonne, IL 60439 USA

[2] Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA

[3] Seoul Natl Univ Sci & Technol, Mfg Syst & Design Engn Program, Seoul, South Korea

[4] Univ Calif Merced, Dept Mech Engn, Merced, CA USA

[5] Stanford Univ, Dept Mat & Sci Engn, Stanford, CA 94305 USA

[6] Sungkyunkwan Univ, Sch Mech Engn, Suwon 440746, South Korea

关键词: Solid oxide fuel cells;    Cathode;    Oxygen reduction kinetics;    Grain boundary;   

DOI  :  10.1016/j.jpowsour.2015.06.149

来源: Elsevier

【 摘 要 】

We report systematic investigation of the surface properties of yttria-stabilized zirconia (YSZ) electrolytes with the control of the grain boundary (GB) density at the surface, and its effects on electrochemical activities. The GB density of thin surface layers deposited on single crystal YSZ substrates is controlled by changing the annealing temperature (750-1450 degrees C). Higher oxygen reduction reactions (ORR) kinetics is observed in samples annealed at lower temperatures. The higher ORR activity is ascribed to the higher GB density at the YSZ surface where 'mobile' oxide ion vacancies are more populated. Meanwhile, oxide ion vacancies concurrently created with yttrium segregation at the surface at the higher annealing temperature are considered inactive to oxygen incorporation reactions. Our results provide additional insight into the interplay between the surface chemistry, microstructures, and electrochemical activity. They potentially provide important guidelines for engineering the electrolyte electrode interfaces of solid oxide fuel cells for higher electrochemical performance. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free