Journal article
Effects of strong cathodic polarization of the Ni-YSZ interface
Department of Energy Conversion and Storage, Technical University of Denmark1
Imaging and Structural Analysis, Department of Energy Conversion and Storage, Technical University of Denmark2
Mixed Conductors, Department of Energy Conversion and Storage, Technical University of Denmark3
Department of Chemistry, Technical University of Denmark4
Applied Electrochemistry, Department of Energy Conversion and Storage, Technical University of Denmark5
Fundamental Electrochemistry, Department of Energy Conversion and Storage, Technical University of Denmark6
Long-term strong cathodic polarization experiments of down to -2.4 V vs. E°(O2) of the Ni-YSZ interface were performed at 900°C in 97% H2/3% H2O on model electrodes. The Ni-YSZ interface underwent extensive changes and a large affected volume with a complex microstructure and phase distribution resulted.
Impedance spectroscopy shows initial decrease but later increase in the series resistance and polarization resistance during the 140-160 h of polarization, and significant inductive behavior. An intermetallic Ni-Zr phase that formed during polarization was preserved when the polarization was kept during cooling, and was identified post-mortem by transmission electron microscopy as Ni7Zr2.
ZrO2 nanoparticles were formed on the Ni-gas surface next to the Ni-YSZ-gas triple phase boundary. Explanations of the observed features are offered based on electron microscopy and impedance spectroscopy.
| Language: | English |
|---|---|
| Publisher: | The Electrochemical Society |
| Year: | 2016 |
| Pages: | 1217-1227 |
| ISSN: | 19457111 and 00134651 |
| Types: | Journal article |
| DOI: | 10.1149/2.0871610jes |
| ORCIDs: | Hansen, Karin Vels , Chen, Ming , Thydén, Karl Tor Sune , Simonsen, Søren Bredmose , Koch, Søren and Mogensen, Mogens Bjerg |
