Abstract
| Original language | English |
|---|---|
| Pages (from-to) | B322-B329 |
| Number of pages | 8 |
| Journal | Journal of the Electrochemical Society |
| Volume | 156 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2009 |
| MoE publication type | A1 Journal article-refereed |
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Keywords
- redox potential
- redox cycling
- redox strain
- Ni-yttria-stabilized zirconia
- YSZ
- cermet
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Dimensional behavior of Ni-YSZ composites during redox cycling. / Pihlatie, Mikko (Corresponding Author); Kaiser, Andreas; Larsen, P. H.; Mogensen, Mogens.
In: Journal of the Electrochemical Society, Vol. 156, No. 3, 2009, p. B322-B329.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - Dimensional behavior of Ni-YSZ composites during redox cycling
AU - Pihlatie, Mikko
AU - Kaiser, Andreas
AU - Larsen, P. H.
AU - Mogensen, Mogens
PY - 2009
Y1 - 2009
N2 - The dimensional behavior of Ni–yttria-stabilized zirconia (YSZ) cermets during redox cycling was tested in dilatometry within the temperature range 600–1000°C. The effect of humidity on redox stability was investigated at intermediate and low temperatures. We show that both the sintering of nickel depending on temperature of the initial reduction and the operating conditions, and the temperature of reoxidation are very important for the size of the dimensional change. Cumulative redox strain (CRS) is shown to be correlated with temperature. Measured maximum CRS after three redox cycles varies within 0.25–3.2% dL/L in dry gas and respective temperature range of 600–1000°C . A high degree of redox reversibility was reached at low temperature, however, reversibility is lost at elevated temperatures. We found that at 850°C, 6% steam and a very high pH2O/pH2 ratio is detrimental for redox stability, whereas at 600°C no negative effect was observed. Pre-reduction at 1100 instead of 800°C more than doubled redox strain on reoxidation at 800°C. For samples similarly pre-reduced at 1000°C, lowering the reoxidation temperature from 1000 to 750°C or below reduces the redox strain to less than half.
AB - The dimensional behavior of Ni–yttria-stabilized zirconia (YSZ) cermets during redox cycling was tested in dilatometry within the temperature range 600–1000°C. The effect of humidity on redox stability was investigated at intermediate and low temperatures. We show that both the sintering of nickel depending on temperature of the initial reduction and the operating conditions, and the temperature of reoxidation are very important for the size of the dimensional change. Cumulative redox strain (CRS) is shown to be correlated with temperature. Measured maximum CRS after three redox cycles varies within 0.25–3.2% dL/L in dry gas and respective temperature range of 600–1000°C . A high degree of redox reversibility was reached at low temperature, however, reversibility is lost at elevated temperatures. We found that at 850°C, 6% steam and a very high pH2O/pH2 ratio is detrimental for redox stability, whereas at 600°C no negative effect was observed. Pre-reduction at 1100 instead of 800°C more than doubled redox strain on reoxidation at 800°C. For samples similarly pre-reduced at 1000°C, lowering the reoxidation temperature from 1000 to 750°C or below reduces the redox strain to less than half.
KW - redox potential
KW - redox cycling
KW - redox strain
KW - Ni-yttria-stabilized zirconia
KW - YSZ
KW - cermet
U2 - 10.1149/1.3046121
DO - 10.1149/1.3046121
M3 - Article
VL - 156
SP - B322-B329
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
SN - 0013-4651
IS - 3
ER -