Characterization of Ni-cermet degradation phenomena I. Long term resistivity monitoring, image processing and X-ray fluorescence analysis

Research output: Contribution to journalArticlepeer-review

Authors

  • M. V. Ananyev
  • D. I. Bronin
  • D. A. Osinkin
  • V. A. Eremin
  • L. G J De Haart
  • J. Mertens

Colleges, School and Institutes

Abstract

The present paper is devoted to Ni-cermet degradation phenomena and places emphasis on experimental approaches and data handling. The resistivity of Ni-YSZ cermet (nickel and 8 mol.% yttria stabilized zirconia) anode substrates was monitored during 3000 h at 700 and 800 °C in a gas mixture of 80 vol.% water vapor and 20 vol.% hydrogen. The experimentally evaluated dependence of resistivity of the Ni-YSZ substrates can be well described by exponential decay functions. Post test analysis by image processing and XRF (X-ray fluorescence) analysis for characterization of the microstructure and elemental composition were carried out for virgin samples and after 300, 1000 and 3000 h of exposure time. The 3D-microstructure was reconstructed using an original spheres packing algorithm. Two processes leading to the Ni-YSZ degradation were observed: Ni-phase particle coarsening and volatilization. The effect of these processes on resistivity and such microstructure parameters as porosity, Ni-phase fraction, Ni and YSZ phases particle size distributions, triple phase boundary length, and tortuosity factor are considered in this paper.

Details

Original languageEnglish
Pages (from-to)414-426
Number of pages13
JournalJournal of Power Sources
Volume286
Early online date30 Mar 2015
Publication statusPublished - 15 Jul 2015

Keywords

  • Degradation, Image processing, Microstructure, Ni-YSZ, Solid oxide fuel cell, X-ray fluorescence