Abstract
Oxygen electrodes for solid oxide cells were prepared by a consecutive infiltration of a gadolinium doped ceria (Ce0.8Gd0.2O1.9, CGO) barrier layer and a lanthanum cobalt nickelate (La0.95Co0.4Ni0.6O3,
LCN) electro catalyst layer into a porous yttrium doped zirconia (YSZ)
backbone. The influences of the following parameters on the
microstructure of the formed CGO barrier layer and on the
electrochemical performance of the cells were studied: i) surfactants
and wetting agents, ii) ceria/gadolinia coverage, iii) calcination
profiles and iv) exposure temperature during testing. The infiltration
process of the CGO barrier layer was optimized and a slow, pH controlled
decomposition of urea containing precursor solutions was found to be
most effective. For these cells a decrease of 84% in the polarization
resistance (Rp) was achieved compared to cells
without a barrier layer. Furthermore, a better initial performance and
only a small increase of the cell-resistance with increasing exposure
temperatures during testing were obtained. A complete and homogenous
covering of the YSZ backbone with Ce0.8Gd0.2O1.9 was found to be necessary to maintain high performance also at higher exposure temperatures (> 800 °C).
Original language | English |
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Journal | Solid State Ionics |
Volume | 304 |
Pages (from-to) | 51-59 |
ISSN | 0167-2738 |
DOIs | |
Publication status | Published - 2017 |
Keywords
- Infiltration
- Barrier layer
- Electro-catalyst
- Solid oxide fuel cell
- Cathode