MICROSCOPY Vol.47▶No.3 2012
â– Feature Articles: Imaging of Battery Materials by TEM

Observation of Redox Reactions at the Interfaces between Electrodes and Electrolytes of Solid Oxide Fuel Cells

Takayoshi Tanji

Abstract: Redox reactions at tri-phase interfaces of Yttria Stabilized Zirconia (YSZ), which is a typical electrolyte for a Solid Oxide Fuel Cell (SOFC), and platinum electrode in a vacuum or gas atmosphere are investigated by in situ electron holography and Electron Energy Loss Spectroscopy (EELS). Electron holography shows that heating specimen makes the inner potential shallow at the interface. The inner potential recovers by flowing oxygen gas even at the same high temperature. EELS spectra show the change of valence state of zirconium ions at the interfaces from +4 to +3.

Key words: SOFC, Electron holography, EELS, YSZ, in situ observation