Intercalation of Thin Film Gd-doped Ceria Barrier Layers in Electrolyte-Supported Solid Oxide Cells: Physico-chemical Aspects
| Autor: | Rémi Costa, Noriko Sata, Matthias Riegraf, Feng Han |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
solid oxide fuel cell (SOFC) Scanning electron microscope Oxide ESC residual stress Gd-doped Ceria (CGO) Electron beam physical vapor deposition Dielectric spectroscopy chemistry.chemical_compound chemistry Chemical engineering Phase (matter) physical vapor deposition (PVD) General Materials Science Thin film zirconate Polarization (electrochemistry) Yttria-stabilized zirconia |
| Popis: | To minimize alteration of the La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF)/Gd0.2Ce0.8O2-δ(CGO20)/Y0.06Zr0.94O2-δ(3YSZ) interface via strontium zirconate formation in solid oxide cells, electron beam physical vapor deposition was employed to manufacture dense, thin gadolinium-doped ceria (CGO) interlayers. CGO layers with thicknesses of 0.15, 0.3, and 0.5 μm were integrated in state-of-the-art 5 × 5 cm2-large electrolyte-supported cells, and their performance characteristics and degradation behavior were investigated. Electrochemical impedance spectroscopy measurements are correlated with a postmortem scanning electron microscopy/energy-dispersive X-ray spectroscopy analysis to show that 0.15 μm-thick layers lead to the formation of a continuous Sr-containing secondary phase at the CGO/YSZ interface, likely related to the formation of a SrO-ZrO2 phase. Major performance losses were confirmed by an increase in both Ohmic and polarization resistance with an increase in the frequency region ∼103 Hz. Cells with 0.3 μm- and 0.5 μm-thick CGO layers showed similar high performance and low degradation rates over a testing period of ∼800 h. The YSZ/CGO interface of the cells with a 0.3 μm-thick CGO layer showed the formation of a discontinuous Sr-containing secondary phase; however, performance losses were still successfully prevented. Furthermore, it is observed that 0.5 μm-thick CGO layers were sufficient to suppress the formation of the Sr-containing secondary phase. |
| Databáze: | OpenAIRE |
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