Coupling between creep and redox behavior in nickel - yttria stabilized zirconia observed in-situ by monochromatic neutron imaging

Research output: Contribution to journalArticle

Abstract

Ni-YSZ (nickel - yttria stabilized zirconia) is a material widely used for electrodes and supports in solid oxide electrochemical cells. The mechanical and electrochemical performance of these layers, and thus the whole cell, depends on their microstructure. During the initial operation of a cell, NiO is reduced to Ni. When this process is conducted under external load, like also present in a stack assembly, significant deformations of NiO/Ni-YSZ composite samples are observed. The observed creep is orders of magnitude larger than the one observed after reduction during operation. This phenomenon is referred to as accelerated creep and is expected to have a significant influence on the microstructure development and stress field present in the Ni-YSZ in solid oxide electrochemical cells (SOCs), which is highly important for the durability of the SOC. In this work we present energy selective neutron imaging studies of the accelerated creep phenomenon in Ni/NiO-YSZ composite during reduction and also during oxidation. This approach allowed us to observe the phase transition and the creep behavior simultaneously in-situ under SOC operation-like conditions.

Details

Authors
  • Malgorzata Grazyna Makowska
  • Luise Theil Kuhn
  • Henrik Lund Frandsen
  • Erik Mejdal Lauridsen
  • Salvatore De Angelis
  • Lars Nilausen Cleemann
  • Manuel Morgano
  • Pavel Trtik
  • Markus Strobl
External organisations
  • Technical University of Denmark
  • Paul Scherrer Institute
  • European Spallation Source ESS AB
  • Xnovo Technology ApS
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Other Materials Engineering

Keywords

  • Creep, Neutron imaging, Ni-YSZ cermet, Solid oxide cells
Original languageEnglish
Pages (from-to)167-175
Number of pages9
JournalJournal of Power Sources
Volume340
Publication statusPublished - 2017 Feb 1
Publication categoryResearch
Peer-reviewedYes