Operando and In situ X-ray Spectroscopies of Degradation in La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ Thin Film Cathodes in Fuel Cells
Information from ex situ characterization can fall short in describing complex materials systems simultaneously exposed to multiple external stimuli. Operando X-ray absorption spectroscopy (XAS) was used to probe the local atomistic and electronic structure of specific elements in a La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) thin film cathode exposed to air contaminated with H2O and CO2 under operating conditions. While impedance spectroscopy showed that the polarization resistance of the LSCF cathode increased upon exposure to both contaminants at 750°C, XAS near-edge and extended fine structure showed that the degree of oxidation for Fe and Co decreases with increasing temperature. Synchrotron-based X-ray photoelectron spectroscopy tracked the formation and removal of a carbonate species, a Co phase, and different oxygen moieties as functions of temperature and gas. The combined information provides insight into the fundamental mechanism by which H2O and CO2 cause degradation in the cathode of solid oxide fuel cells.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Heterogeneous Functional Materials Center (HeteroFoaM)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- DOE Contract Number:
- SC0001061
- OSTI ID:
- 1370161
- Journal Information:
- ChemSusChem, Vol. 7, Issue 11; Related Information: HeteroFoaM partners with University of South Carolina (lead); University of California, Santa Barbara; University of Connecticut; Georgia Institute of Technology; Princeton University; Rochester Institute of Technology; Savannah River National Laboratory; University of South Carolina; University of Utah; ISSN 1864-5631
- Publisher:
- ChemPubSoc Europe
- Country of Publication:
- United States
- Language:
- English
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