Interdiffusion between gadolinia doped ceria and yttria stabilized zirconia in solid oxide fuel cells: Experimental investigation and kinetic modeling

Huixia Xu*, Kaiming Cheng, Ming Chen, Lijun Zhang, Karen Brodersen, Yong Du

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Interdiffusion between the yttria stabilized zirconia (YSZ) electrolyte and the gadolinia doped ceria (CGO) barrier layer is one of the major causes to the increment of ohmic resistance in solid oxide fuel cells (SOFCs). We present in this work experimental investigations on CGO-YSZ bi-layer electrolyte sintered at 1250 °C or 1315 °C and element transport as a function of sintering temperature and dwelling time. In order to quantitatively simulate the experimental observations, the CALPHAD-type thermodynamic assessment of the CGO-YSZ system is performed by simplifying the system to a CeO2–ZrO2 quasi-binary system, and the kinetic descriptions (atomic mobilities) are constructed based on critical review of literature data. The CGO-YSZ interdiffusion is then modeled with the DICTRA software and the simulation results are compared with the experimental data under different sintering or long-term operating conditions. The corresponding ohmic resistance of the bi-layer electrolyte is predicted based on the simulated concentration profile. The results implies that the interdiffusion across the CGO-YSZ interface happens mainly during sintering at high temperature, while during long-term operation at relatively lower temperature the impact of interdiffusion on cell degradation is negligible.
Original languageEnglish
Article number227152
JournalJournal of Power Sources
Volume441
Number of pages9
ISSN0378-7753
DOIs
Publication statusPublished - 2019

Keywords

  • Solid oxide fuel cell
  • Degradation
  • Interdiffusion
  • Kinetic modeling
  • DICTRA

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