Electro-chemo-mechanical studies of perovskite-structured mixed ionic-electronic conducting SrSn1-xFexO3-x/2+δ Part III: Thermal and chemical expansion

  • Chang Sub Kim
  • Nicola H. Perry
  • Sean R. Bishop
  • Harry L. Tuller
Article

Abstract

The thermal and chemical expansion of a potential solid oxide fuel cell (SOFC) cathode material SrSn0.65Fe0.35O3–0.35/2+δ (SSF35) were investigated to assess its thermo-chemo-mechanical stability at SOFC operating temperatures and to establish the correlation between defect concentrations (oxygen vacancies and electrons) and chemical expansion with the aid of the defect chemical model reported in part I of this study. Thermochemical expansion was measured as a function of temperature and oxygen partial pressure. The chemical expansion of SSF35 showed a strong correlation with changes in oxygen nonstoichiometry associated with changes in Fe valence state. Coefficients of both chemical (CCE) and thermal (CTE) expansion were calculated and found to be smaller than that of the closely related mixed conducting perovskite oxide SrTi0.65Fe0.35O3–0.35/2+δ (STF35). The thermal expansion coefficient of SSF was found to be close to that of YSZ (most popular solid oxide electrolyte), which makes SSF35 more attractive in terms of overall thermo-chemical stability. The chemical expansion of SSF35 showed decreasing CCE with increasing temperature and decreasing CTE with increasing oxygen deficiency, both opposite to the trends observed for STF35. Distortion in symmetry from the cubic structure seems to be responsible for the smaller coefficients and increasing asymmetry with expansion seems accountable for opposite trends of CCE and CTE compared to the STF counterpart.

Keywords

Chemo-mechanics Chemical expansion Perovskite oxide Sofc cathode Oxygen non-stoichiometry Defect chemistry 

Notes

Acknowledgments

This research was carried out as a part of the activity of the Skoltech-MIT Center for Electrochemical Energy Storage. Structural characterization of the materials was conducted in the MRSEC Shared Experimental Facilities at MIT, supported by the National Science Foundation under award number DMR-1419807. Thanks go to Dr. Charlie Settens for assistance with XRD.

References

  1. 1.
    S.R. Bishop, K.L. Duncan, E.D. Wachsman, Thermo-chemical expansion in strontium-doped lanthanum cobalt iron oxide. J. Am. Ceram. Soc. 93, 4115–4121 (2010)CrossRefGoogle Scholar
  2. 2.
    S.B. Adler, Chemical Expansivity of Electrochemical Ceramics. J. Am. Ceram. Soc. 84, 2117–2119 (2001)CrossRefGoogle Scholar
  3. 3.
    S.R. Bishop et al., Chemical Expansion: Implications for Electrochemical Energy Storage and Conversion Devices. Annu. Rev. Mater. Res. 44, 205–239 (2014)CrossRefGoogle Scholar
  4. 4.
    C.S. Kim, S.R. Bishop, N.H. Perry, H.L. Tuller, Electro-chemo-mechanical studies of perovskite-structured mixed ionic-electronic conducting SrSn1-xFexO3-x/2+δpart I: Defect chemistry. J. Electroceram. 38, 74–80 (2017)CrossRefGoogle Scholar
  5. 5.
    C.S. Kim, S.R. Bishop, H.L. Tuller, Electro-chemo-mechanical studies of perovskite-structured mixed ionic-electronic conducting SrSn1-xFexO3-x/2+δ part II: Electrical conductivity and cathode performance. J. Electroceram., 1–8 (2017)Google Scholar
  6. 6.
    N.H. Perry, J.J. Kim, S.R. Bishop, H.L. Tuller, Strongly coupled thermal and chemical expansion in the perovskite oxide system Sr(Ti,Fe)O3-a. J. Mater. Chem. A 3, 3602–3611 (2015)CrossRefGoogle Scholar
  7. 7.
    D. Marrocchelli, N. Perry, S. Bishop, Understanding chemical expansion in perovskite-structured oxides. Phys. Chem. Chem. Phys. 17, 10028–10039 (2015)CrossRefGoogle Scholar
  8. 8.
    N.H. Perry, J.E. Thomas, D. Marrocchelli, S.R. Bishop, H.L. Tuller, Isolating the Role of Charge Localization in Chemical Expansion: (La,Sr)(Ga,Ni)O3-x Case Study. ECS Trans. 57, 1879–1884 (2013)CrossRefGoogle Scholar
  9. 9.
    R.D. Shannon, Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr. Sect. A. 32, 751–767 (1976)CrossRefGoogle Scholar
  10. 10.
    X. Chen, J. Yu, S.B. Adler, Thermal and chemical expansion of Sr-doped lanthanum cobalt oxide (La1-xSrxCoO3-δ). Chem. Mater. 17, 4537–4546 (2005)CrossRefGoogle Scholar
  11. 11.
    N.H. Perry, D. Marrocchelli, S.R. Bishop, H.L. Tuller, (Invited) Understanding and Controlling Chemo-Mechanical Coupling in Perovskite Oxides. ECS Trans. 72, 1–8 (2016)CrossRefGoogle Scholar
  12. 12.
    V.V. Kharton, A.a. Yaremchenko, M.V. Patrakeev, E.N. Naumovich, F.M.B. Marques, Thermal and chemical induced expansion of La0.3Sr0.7(Fe,Ga)O3−δ ceramics. J. Eur. Ceram. Soc. 23, 1417–1426 (2003)CrossRefGoogle Scholar
  13. 13.
    S. McIntosh, J.F. Vente, W.G. Haije, D.H.A. Blank, H.J.M. Bouwmeester, Oxygen stoichiometry and chemical expansion of Ba0.5Sr0.5Co0.8Fe4O3-δ- measured by in situ neutron diffraction. Chem. Mater. 18, 2187–2193 (2006)CrossRefGoogle Scholar
  14. 14.
    I. Yasuda, M. Hishinuma, Lattice expansion of acceptor-doped lanthanum chromites under high-temperature reducing atmospheres. Electrochemistry 68, 526 (2000)Google Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Materials Science and EngineeringMassachusetts Institute of TechnologyCambridgeUSA
  2. 2.International Institute for Carbon-Neutral Energy Research (WPI-I2CNER)Kyushu UniversityFukuokaJapan
  3. 3.Department of Materials Science and Engineering and Materials Research LaboratoryUniversity of Illinois at Urbana-ChampaignUrbanaUSA
  4. 4.Materials Research LaboratoryMassachusetts Institute of TechnologyCambridgeUSA
  5. 5.Redox Power SystemsCollege ParkUSA

Personalised recommendations