Understanding degradation of solid oxide electrolysis cells through modeling of electrochemical potential profiles

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Establishing the spatial distribution of the various chemical and electrochemical potentials in an operating SOEC is critical as several degradation mechanisms are tightly connected to them, but at the same time very challenging to achieve experimentally. Such distributions are presented here on the basis of a two dimensional bi-layer electrolyte SOC model including for both electrodes a description of activation, concentration, and conversion losses. An extensive parametric study is reported to illustrate the influence of the electrode polarization resistances, the ionic and electronic conductivities in the electrolyte, the gas composition, temperature, and pressure on the current density distribution over the cell and the oxygen activity distribution within the electrolyte. The developed model is further used to simulate long-term durability experiments during different stages of operation, thereby helping to rationalize microstructural and chemical changes observed in post-mortem analysis. Finally, measures to mitigate degradation by changing conditions of operation, material or electrode properties or overall cell geometry are suggested.
Original languageEnglish
JournalElectrochimica Acta
Volume189
Pages (from-to)265-282
Number of pages18
ISSN0013-4686
DOIs
Publication statusPublished - 2016

Keywords

  • bi-layer electrolyte
  • degradation
  • electrochemical potential profiles
  • modeling
  • SOEC

Cite this

@article{6b83c901d78f4375a35f879ef65fa6f3,
title = "Understanding degradation of solid oxide electrolysis cells through modeling of electrochemical potential profiles",
abstract = "Establishing the spatial distribution of the various chemical and electrochemical potentials in an operating SOEC is critical as several degradation mechanisms are tightly connected to them, but at the same time very challenging to achieve experimentally. Such distributions are presented here on the basis of a two dimensional bi-layer electrolyte SOC model including for both electrodes a description of activation, concentration, and conversion losses. An extensive parametric study is reported to illustrate the influence of the electrode polarization resistances, the ionic and electronic conductivities in the electrolyte, the gas composition, temperature, and pressure on the current density distribution over the cell and the oxygen activity distribution within the electrolyte. The developed model is further used to simulate long-term durability experiments during different stages of operation, thereby helping to rationalize microstructural and chemical changes observed in post-mortem analysis. Finally, measures to mitigate degradation by changing conditions of operation, material or electrode properties or overall cell geometry are suggested.",
keywords = "bi-layer electrolyte, degradation, electrochemical potential profiles, modeling, SOEC",
author = "Christodoulos Chatzichristodoulou and Ming Chen and Hendriksen, {Peter Vang} and Torben Jacobsen and Mogensen, {Mogens Bjerg}",
year = "2016",
doi = "10.1016/j.electacta.2015.12.067",
language = "English",
volume = "189",
pages = "265--282",
journal = "Electrochimica Acta",
issn = "0013-4686",
publisher = "Pergamon Press",

}

TY - JOUR

T1 - Understanding degradation of solid oxide electrolysis cells through modeling of electrochemical potential profiles

AU - Chatzichristodoulou, Christodoulos

AU - Chen, Ming

AU - Hendriksen, Peter Vang

AU - Jacobsen, Torben

AU - Mogensen, Mogens Bjerg

PY - 2016

Y1 - 2016

N2 - Establishing the spatial distribution of the various chemical and electrochemical potentials in an operating SOEC is critical as several degradation mechanisms are tightly connected to them, but at the same time very challenging to achieve experimentally. Such distributions are presented here on the basis of a two dimensional bi-layer electrolyte SOC model including for both electrodes a description of activation, concentration, and conversion losses. An extensive parametric study is reported to illustrate the influence of the electrode polarization resistances, the ionic and electronic conductivities in the electrolyte, the gas composition, temperature, and pressure on the current density distribution over the cell and the oxygen activity distribution within the electrolyte. The developed model is further used to simulate long-term durability experiments during different stages of operation, thereby helping to rationalize microstructural and chemical changes observed in post-mortem analysis. Finally, measures to mitigate degradation by changing conditions of operation, material or electrode properties or overall cell geometry are suggested.

AB - Establishing the spatial distribution of the various chemical and electrochemical potentials in an operating SOEC is critical as several degradation mechanisms are tightly connected to them, but at the same time very challenging to achieve experimentally. Such distributions are presented here on the basis of a two dimensional bi-layer electrolyte SOC model including for both electrodes a description of activation, concentration, and conversion losses. An extensive parametric study is reported to illustrate the influence of the electrode polarization resistances, the ionic and electronic conductivities in the electrolyte, the gas composition, temperature, and pressure on the current density distribution over the cell and the oxygen activity distribution within the electrolyte. The developed model is further used to simulate long-term durability experiments during different stages of operation, thereby helping to rationalize microstructural and chemical changes observed in post-mortem analysis. Finally, measures to mitigate degradation by changing conditions of operation, material or electrode properties or overall cell geometry are suggested.

KW - bi-layer electrolyte

KW - degradation

KW - electrochemical potential profiles

KW - modeling

KW - SOEC

U2 - 10.1016/j.electacta.2015.12.067

DO - 10.1016/j.electacta.2015.12.067

M3 - Journal article

VL - 189

SP - 265

EP - 282

JO - Electrochimica Acta

JF - Electrochimica Acta

SN - 0013-4686

ER -