Electrical and Hydrogen Reduction Enhances Kinetics in Doped Zirconia and Ceria: II. Mapping Electrode Polarization and Vacancy Condensation in YSZ

Abstract

Knowing the correlation between grain boundary mobility and oxygen potential in yttria stabilized zirconia (YSZ), we have utilized the grain size as a microstructural marker to map local oxygen potential. Abrupt oxygen potential transition is established under a large current density and in thicker samples. Cathodically depressed oxygen potential can be easily triggered by poor electrode kinetics or in an oxygen-lean environment. Widespread cavitation in the presence of highly reducing oxygen potential suggests oxygen vacancy condensation instead of oxygen bubble formation as commonly assumed for solid oxide fuel/electrolysis cells. These results also suggest electrode kinetics has a direct influence on the microstructure and properties of ceramics sintered under a large electric current.

References in corpus (2)

• A Computational Study of Yttria-Stabilized Zirconia: II. Cation Diffusion
• A Computational Study of Yttria-Stabilized Zirconia: I. Using Crystal Chemistry to Search for the Ground State on a Glassy Energy Landscape

Cited by in corpus (4)

• Mobility Transition at Grain Boundaries in Two-Step Sintered 8 mol% Yttria Stabilized Zirconia
• Potential jumps at transport bottlenecks cause instability of nominally ionic solid electrolytes in electrochemical cells
• Oxygen Potential Transition in Mixed Conducting Oxide Electrolyte
• Electron Localization Enhances Cation Diffusion in Transition Metal Oxides: An Electronic Trebuchet Effect