Degradation of oxygen reduction reaction kinetics in porous La0.6Sr0.4Co0.2Fe0.8O3-δ cathodes due to aging-induced changes in surface chemistry

被引:26
作者
Baque, Laura C. [1 ]
Soldati, Analia L. [1 ]
Teixeira-Neto, Erico [2 ]
Troiani, Horacio E. [1 ]
Schreiber, Anja [3 ]
Serquis, Adriana C. [1 ]
机构
[1] Ctr Atom Bariloche, CNEA, CONICET, Ave Bustillo 9500,R8402AGP, San Carlos De Bariloche, Argentina
[2] Brazilian Ctr Res Energy & Mat, Brazilian Nanotechnol Natl Lab, Rua Giuseppe Maximo Scolfaro 10-000, Campinas, SP, Brazil
[3] Deutsch GeoForschungsZentrum GFZ, Helmholtz Zentrum Potsdam, Sekt Geomech & Rheol 4 2, C 155, D-14473 Potsdam, Germany
关键词
Solid Oxide Fuel Cells; Degradation; Surface segregation; Scanning Transmission Electron Microscopy; Energy Dispersive Spectroscopy; Electrochemical Impedance Spectroscopy; ELECTROCHEMICAL PERFORMANCE; DEGREES-C; IMPEDANCE; SEGREGATION; MECHANISM; LA0.6SR0.4COO3-DELTA; TRANSMISSION; ELECTRODES; EXCHANGE;
D O I
10.1016/j.jpowsour.2016.10.090
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The modification of surface composition after long-term operation is one of the most reported degradation mechanisms of (La,Sr)(Co,Fe)O3-delta (LSCFO) cathodes for Solid Oxide Fuel Cells (SOFCs). Nevertheless, its effect on the oxygen reduction reaction kinetics of porous LSCFO cathodes has not been yet reliably established. In this work, La- and Sr-enrichment at the LSCFO surface of porous cathodes has been induced after 50 h aging at 800 degrees C under air. Such cation redistribution can extend up to -400 nm depth under the LSCFO surface as detected by high resolution Scanning Transmission Electron Microscopy-Energy Dispersive Spectroscopy maps acquired inside the cathode pores. The observed surface chemical changes hamper the oxygen surface exchange reaction at the LSCFO/gas interface. Accordingly, a suitable Electrochemical Impedance Spectroscopy analysis revealed that the oxygen ion conductivity remains practically unaltered during the aging treatment while the oxygen surface exchange resistance increases up to 1.8 times. As a result, the cathode impedance response deteriorates within the 10-0.1 Hz frequency range during the aging treatment, resulting in a total cathode area specific resistance increase of 150%. The methodology adopted has demonstrated to be very valuable for studying the degradation of SOFC cathodes produced by the modification of surface composition. (C) 2016 Elsevier B.V. All rights reserved.
引用
收藏
页码:166 / 172
页数:7
相关论文
共 42 条
  • [1] Mechanism and kinetics of oxygen reduction on porous La1-xSrxCoO3-δ electrodes
    Adler, SB
    [J]. SOLID STATE IONICS, 1998, 111 (1-2) : 125 - 134
  • [2] Electrode kinetics of porous mixed-conducting oxygen electrodes
    Adler, SB
    Lane, JA
    Steele, BCH
    [J]. JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 1996, 143 (11) : 3554 - 3564
  • [3] Factors governing oxygen reduction in solid oxide fuel cell cathodes
    Adler, SB
    [J]. CHEMICAL REVIEWS, 2004, 104 (10) : 4791 - 4843
  • [4] Strontium surface segregation in La0.58Sr0.4Co0.2Fe0.8O3-δ annealed under compression
    Araki, Wakako
    Yamaguchi, Toni
    Arai, Yoshio
    Malzbender, Juergen
    [J]. SOLID STATE IONICS, 2014, 268 : 1 - 6
  • [5] Effect of Cobalt-Doped Electrolyte on the Electrochemical Performance of LSCFO/CGO Interfaces
    Baque, L.
    Padmasree, K. P.
    Ceniceros Reyes, M. A.
    Troiani, H.
    Arce, M. D.
    Serquis, A.
    Soldati, A.
    [J]. IONIC AND MIXED CONDUCTING CERAMICS 10, 2016, 72 (07): : 117 - 121
  • [6] Effect of Cation Demixing on the Electrochemical Performance of LSCFO Cathodes for SOFCs
    Baque, L.
    Soldati, A.
    Troiani, H.
    Serquis, A.
    [J]. SOLID STATE IONIC DEVICES 10, 2014, 64 (02): : 11 - 16
  • [7] Effect of Aging on the Electrochemical Performance of LSM-YSZ Cathodes
    Baque, L. C.
    Jorgensen, P. S.
    Zhang, W.
    Hansen, K. V.
    Sogaard, M.
    [J]. JOURNAL OF THE ELECTROCHEMICAL SOCIETY, 2015, 162 (09) : F971 - F981
  • [8] Impedance spectroscopic study on well-defined (La,Sr)(Co,Fe)O3-δ model electrodes
    Baumann, Frank S.
    Fleig, Juergen
    Habermeier, Hanns-Ulrich
    Maier, Joachim
    [J]. SOLID STATE IONICS, 2006, 177 (11-12) : 1071 - 1081
  • [9] Interpretation of the Gerischer impedance in solid state ionics
    Boukamp, BA
    Bouwmeester, HJM
    [J]. SOLID STATE IONICS, 2003, 157 (1-4) : 29 - 33
  • [10] Oxygen exchange kinetics of La0.58Sr0.4Co0.2Fe0.8O3 at 600 °C in dry and humid atmospheres
    Bucher, Edith
    Sitte, Werner
    Klauser, Frederik
    Bertel, Erminald
    [J]. SOLID STATE IONICS, 2011, 191 (01) : 61 - 67