• Lee, Shiwoo
• Picard, Yoosuf N.
• Abernathy, Harry W.

Abstract

<jats:p>Atom probe tomography (APT) was utilized to probe composition at the nanoscale across cathode/electrolyte interfaces for anode-supported commercial SOFCs.These SOFCs contained a porous composite cathode layer, consisting of sintered (La<jats:sub>0.8</jats:sub>Sr<jats:sub>0.2</jats:sub>)<jats:sub>0.95</jats:sub>MnO<jats:sub>3</jats:sub> (LSM) and yttria-stabilized zirconia (YSZ). SOFCs were operated up to a 500 h duration at a 0.75 A/cm<jats:sup>2</jats:sup> current density and 800°C. The measured cell voltage increased over the first 100 hours of operation, followed by a steady and linear drop in cell voltage that translated to a 5.35% performance loss per 1000 h. Cation migration behavior was extrapolated through comparisons of compositional profiles acquired by APT across LSM/YSZ particle interfaces for as-sintered, operated, and thermally aged conditions. The results show that operation drives La/Sr away from the LSM nanoparticle surface and Y depletion at the YSZ nanoparticle surface. Energy dispersive spectroscopy (EDS) inside a scanning transmission electron microscope (STEM) provided additional insights regarding Mn aggregation behavior during operation.</jats:p>

Topics

• nanoparticle
• porous
• density
• surface
• composite
• Energy-dispersive X-ray spectroscopy
• current density
• atom probe tomography