Visualization of oxide ionic diffusion at cathode/interlayer/electrolyte interfaces in real flat-tube SOFC cells-stack

摘要

Local distribution of oxide ionic flows was visualized at the cathode/interlayer/electrolyte interfaces in real flat tube Solid Oxide Fuel Cells (SOFCs) stacks under operating condition. Isotope labeling (18O labeling) technique and secondary ion mass spectrometry (SIMS) analysis enabled us to visualize the trace of 18O diffusion through the (La,Sr)FeO₃ cathode/CeO₂ interlayer/YSZ electrolyte interfaces in a “frozen state”. The difference of 18O intensity was observed at (La,Sr)FeO₃ cathode as well as CeO₂ interlayer among different cells. This difference can come from the surface 16O/18O exchange rates of (La,Sr)FeO₃ cathode and the amounts of 18O₂ supplied to cells. Local difference of 18O intensity suggested the local distribution of oxide ionic currents at different cells in the stack.