The Electrochemical Properties of Sr(Ti,Fe)O 3-δ for Anodes in Solid Oxide Fuel Cells [electronic resource].
- Published:
- Washington, D.C. : United States. National Nuclear Security Administration, 2017.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy - Physical Description:
- pages F364-F371 : digital, PDF file
- Additional Creators:
- Ames Laboratory
United States. National Nuclear Security Administration
National Science Foundation (U.S.)
United States. Department of Energy. Office of Scientific and Technical Information - Access Online:
- www.osti.gov
- Summary:
- Reduction-stable mixed ionic and electronic conductors such as Sr(Ti,Fe)O3-δ (STF) are promising materials for application in anodes of solid oxide fuel cells. The defect chemistry of STF and its properties as solid oxide fuel cell (SOFC) cathode have been studied thoroughly, while mechanistic investigations of its electrochemical properties as SOFC anode material are still scarce. In this study, thin film model electrodes of STF with 30% and 70% Fe content were investigated in H2+H2O atmosphere by electrochemical impedance spectroscopy. Lithographically patterned thin film Pt current collectors were applied on top or beneath the STF thin films to compensate for the low electronic conductivity under reducing conditions. Oxygen exchange resistances, electronic and ionic conductivities and chemical capacitances were quantified and discussed in a defect chemical model. Increasing Fe content increases the electro-catalytic activity of the STF surface as well as the electronic and ionic conductivity. Current collectors on top also increase the electrochemical activity due to a highly active Pt-atmosphere-STF triple phase boundary. Furthermore, the electrochemical activity depends decisively on the H2:H2O mixing ratio and the polarization. Lastly, Fe0 nanoparticles may evolve on the surface in hydrogen rich atmospheres and increase the hydrogen adsorption rate.
- Subject(s):
- Note:
- Published through SciTech Connect.
02/18/2017.
Journal of the Electrochemical Society 164 4 ISSN 0013-4651 AM
Andreas Nenning; Lukas Volgger; Elizabeth Miller; Liliana V. Mogni; Scott Barnett; Jürgen Fleig. - Funding Information:
- NA0002135
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