Abstract
High fuel utilization (Uf) conditions in a small-scale electrolyte-supported solid oxide fuel cell (SOFC) with an Ni-ScSZ anode were approximated by adjusting the gas composition to correspond to that in the downstream region of an SOFC stack. At Uf = 80%, and with a cell voltage of 0.5 V, the ohmic resistance fluctuated slightly from the early stages of operation, and became much more significant after 80 h. High current density and large polarization were found to promote Ni agglomeration, leading to insufficient connectivity of the Ni nanoparticles. At Uf = 95%, and with a cell voltage of 0.6 V, fluctuations in the polarization were observed at a much earlier stage, which are attributed to the highly humidified fuel. In particular, significant degradation was observed when the compensated anode potential (which incorporates the anode ohmic losses) approached the Ni oxidation potential. Ohmic losses in the anode are considered to influence Ni oxidation by exposing Ni near the electrolyte to a more oxidizing atmosphere with the increase in oxygen ion transport. Stable operation is therefore possible under conditions in which the compensated anode potential does not approach the Ni oxidation potential, assuming a stable interconnected Ni network.
| Original language | English |
|---|---|
| Pages (from-to) | 9386-9399 |
| Number of pages | 14 |
| Journal | International Journal of Hydrogen Energy |
| Volume | 44 |
| Issue number | 18 |
| DOIs | |
| Publication status | Published - Apr 5 2019 |
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All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology
Cite this
Oxidation-induced degradation and performance fluctuation of solid oxide fuel cell Ni anodes under simulated high fuel utilization conditions. / Kawasaki, Tatsuya; Matsuda, Junko; Tachikawa, Yuya; Lyth, Stephen Matthew; Shiratori, Yusuke; Taniguchi, Shunsuke; Sasaki, Kazunari.
In: International Journal of Hydrogen Energy, Vol. 44, No. 18, 05.04.2019, p. 9386-9399.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Oxidation-induced degradation and performance fluctuation of solid oxide fuel cell Ni anodes under simulated high fuel utilization conditions
AU - Kawasaki, Tatsuya
AU - Matsuda, Junko
AU - Tachikawa, Yuya
AU - Lyth, Stephen Matthew
AU - Shiratori, Yusuke
AU - Taniguchi, Shunsuke
AU - Sasaki, Kazunari
PY - 2019/4/5
Y1 - 2019/4/5
N2 - High fuel utilization (Uf) conditions in a small-scale electrolyte-supported solid oxide fuel cell (SOFC) with an Ni-ScSZ anode were approximated by adjusting the gas composition to correspond to that in the downstream region of an SOFC stack. At Uf = 80%, and with a cell voltage of 0.5 V, the ohmic resistance fluctuated slightly from the early stages of operation, and became much more significant after 80 h. High current density and large polarization were found to promote Ni agglomeration, leading to insufficient connectivity of the Ni nanoparticles. At Uf = 95%, and with a cell voltage of 0.6 V, fluctuations in the polarization were observed at a much earlier stage, which are attributed to the highly humidified fuel. In particular, significant degradation was observed when the compensated anode potential (which incorporates the anode ohmic losses) approached the Ni oxidation potential. Ohmic losses in the anode are considered to influence Ni oxidation by exposing Ni near the electrolyte to a more oxidizing atmosphere with the increase in oxygen ion transport. Stable operation is therefore possible under conditions in which the compensated anode potential does not approach the Ni oxidation potential, assuming a stable interconnected Ni network.
AB - High fuel utilization (Uf) conditions in a small-scale electrolyte-supported solid oxide fuel cell (SOFC) with an Ni-ScSZ anode were approximated by adjusting the gas composition to correspond to that in the downstream region of an SOFC stack. At Uf = 80%, and with a cell voltage of 0.5 V, the ohmic resistance fluctuated slightly from the early stages of operation, and became much more significant after 80 h. High current density and large polarization were found to promote Ni agglomeration, leading to insufficient connectivity of the Ni nanoparticles. At Uf = 95%, and with a cell voltage of 0.6 V, fluctuations in the polarization were observed at a much earlier stage, which are attributed to the highly humidified fuel. In particular, significant degradation was observed when the compensated anode potential (which incorporates the anode ohmic losses) approached the Ni oxidation potential. Ohmic losses in the anode are considered to influence Ni oxidation by exposing Ni near the electrolyte to a more oxidizing atmosphere with the increase in oxygen ion transport. Stable operation is therefore possible under conditions in which the compensated anode potential does not approach the Ni oxidation potential, assuming a stable interconnected Ni network.
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UR - http://www.scopus.com/inward/citedby.url?scp=85062698941&partnerID=8YFLogxK
U2 - 10.1016/j.ijhydene.2019.02.136
DO - 10.1016/j.ijhydene.2019.02.136
M3 - Article
AN - SCOPUS:85062698941
VL - 44
SP - 9386
EP - 9399
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
SN - 0360-3199
IS - 18
ER -