Abstract
Degradation-related issues are among the main limitations to make solid oxide electrolysis cells (SOEC) meet performance targets economically viable for long-term operation. In this study, the considered cell presents a premature degradation during electrolysis operation observed after sealing the cell holder and the support pieces providing and releasing H2 electrode gas. This premature degradation is characterized by unusual polarization curve slopes, and appearance of a new impedance contribution at the lowest frequencies of the impedance diagrams recorded. To the best of our knowledge, this new contribution has never been reported for SOECs. Post-mortem analysis of the cell by scanning electron microscopy (SEM)/energy dispersive X-ray (EDX) shows the presence of Si, Al, Na, K, and Ca at the H2 electrode interface (surface and first dozens microns in the volume) and at the Ni-yttria-stabilized zirconia (YSZ)/YSZ interface, contrary to similar cells tested before sealing the pieces. This degradation is related to Si deposition, notably at the Ni/YSZ/H2O triple phase boundaries. Concomitantly, the new contribution observed, leading to a beneficial effect on the cell functioning, is assimilated to a “reactivation” contribution. This reactivation contribution is associated with an H2O adsorption phenomenon and characterized by a relaxation frequency of [1–10 mHz] and a capacitance of ~ 100 F cm−2. The evolution with time of the resistive and capacitive contributions is consistent with the interpretation of the premature cell degradation. A mechanism explaining the cell behavior after this premature degradation is proposed.
| Original language | English |
|---|---|
| Pages (from-to) | 109-123 |
| Number of pages | 15 |
| Journal | Journal of solid state electrochemistry |
| Volume | 23 |
| Issue number | 1 |
| Early online date | 4 Oct 2018 |
| DOIs | |
| Publication status | Published - 19 Jan 2019 |
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Keywords
- UT-Hybrid-D
- Electrochemical impedance spectroscopy
- Hydrogen
- Reaction mechanisms
- Si impurities
- Solid oxide electrolysis cell
- Degradation
Cite this
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Premature degradation study of a cathode-supported solid oxide electrolysis cell. / Nechache, Aziz (Corresponding Author); Boukamp, Bernard A.; Cassir, Michel; Ringuedé, Armelle (Corresponding Author).
In: Journal of solid state electrochemistry, Vol. 23, No. 1, 19.01.2019, p. 109-123.Research output: Contribution to journal › Article › Academic › peer-review
TY - JOUR
T1 - Premature degradation study of a cathode-supported solid oxide electrolysis cell
AU - Nechache, Aziz
AU - Boukamp, Bernard A.
AU - Cassir, Michel
AU - Ringuedé, Armelle
N1 - Springer deal
PY - 2019/1/19
Y1 - 2019/1/19
N2 - Degradation-related issues are among the main limitations to make solid oxide electrolysis cells (SOEC) meet performance targets economically viable for long-term operation. In this study, the considered cell presents a premature degradation during electrolysis operation observed after sealing the cell holder and the support pieces providing and releasing H2 electrode gas. This premature degradation is characterized by unusual polarization curve slopes, and appearance of a new impedance contribution at the lowest frequencies of the impedance diagrams recorded. To the best of our knowledge, this new contribution has never been reported for SOECs. Post-mortem analysis of the cell by scanning electron microscopy (SEM)/energy dispersive X-ray (EDX) shows the presence of Si, Al, Na, K, and Ca at the H2 electrode interface (surface and first dozens microns in the volume) and at the Ni-yttria-stabilized zirconia (YSZ)/YSZ interface, contrary to similar cells tested before sealing the pieces. This degradation is related to Si deposition, notably at the Ni/YSZ/H2O triple phase boundaries. Concomitantly, the new contribution observed, leading to a beneficial effect on the cell functioning, is assimilated to a “reactivation” contribution. This reactivation contribution is associated with an H2O adsorption phenomenon and characterized by a relaxation frequency of [1–10 mHz] and a capacitance of ~ 100 F cm−2. The evolution with time of the resistive and capacitive contributions is consistent with the interpretation of the premature cell degradation. A mechanism explaining the cell behavior after this premature degradation is proposed.
AB - Degradation-related issues are among the main limitations to make solid oxide electrolysis cells (SOEC) meet performance targets economically viable for long-term operation. In this study, the considered cell presents a premature degradation during electrolysis operation observed after sealing the cell holder and the support pieces providing and releasing H2 electrode gas. This premature degradation is characterized by unusual polarization curve slopes, and appearance of a new impedance contribution at the lowest frequencies of the impedance diagrams recorded. To the best of our knowledge, this new contribution has never been reported for SOECs. Post-mortem analysis of the cell by scanning electron microscopy (SEM)/energy dispersive X-ray (EDX) shows the presence of Si, Al, Na, K, and Ca at the H2 electrode interface (surface and first dozens microns in the volume) and at the Ni-yttria-stabilized zirconia (YSZ)/YSZ interface, contrary to similar cells tested before sealing the pieces. This degradation is related to Si deposition, notably at the Ni/YSZ/H2O triple phase boundaries. Concomitantly, the new contribution observed, leading to a beneficial effect on the cell functioning, is assimilated to a “reactivation” contribution. This reactivation contribution is associated with an H2O adsorption phenomenon and characterized by a relaxation frequency of [1–10 mHz] and a capacitance of ~ 100 F cm−2. The evolution with time of the resistive and capacitive contributions is consistent with the interpretation of the premature cell degradation. A mechanism explaining the cell behavior after this premature degradation is proposed.
KW - UT-Hybrid-D
KW - Electrochemical impedance spectroscopy
KW - Hydrogen
KW - Reaction mechanisms
KW - Si impurities
KW - Solid oxide electrolysis cell
KW - Degradation
U2 - 10.1007/s10008-018-4116-7
DO - 10.1007/s10008-018-4116-7
M3 - Article
VL - 23
SP - 109
EP - 123
JO - Journal of solid state electrochemistry
JF - Journal of solid state electrochemistry
SN - 1432-8488
IS - 1
ER -