Effect of Interfacial Properties on the Electrochemical Performance of Solid Oxide Fuel Cells

摘要

In this study, we examined the properties of model heterointerfaces created with yttrium-doped SrZrO_3 (SZY) thin films, a type of secondary phase that most frequently occurs at interfaces of solid oxide fuel cells utilizing yttria-stabilized zirconia (YSZ) electrolytes. Electrochemical impedance results of symmetrical cells prepared with LSCF cathodes were evaluated using DRT (distribution of relaxation times) analysis, and ~(18)O isotope exchange depth profiling with SIMS (secondary ion mass spectrometry) analysis was performed on post-tested samples to examine the ionic transport across heterointerfaces. Results showed high polarization resistance contributed by interfacial resistance associated with interfaces with SZY, i.e., LSCF/SZY, SZY/YSZ or SZY/GDC (gadolinia-doped ceria). The careful selection of heterostructure configurations lead to the conclusion that the interfacial contact of SZY with LSCF, YSZ and GDC results into high interfacial resistances, possibly due to an ion blocking effect.