The Electrochemical and Thermal Performances of Ca3Co4O9-δ as a Cathode Material for IT-SOFCs

Abstract

With the aim of application to cathode material in IT-SOFC, 2D misfit layered calcium cobalt oxide Ca3Co4O9-d was studied using XRD, SEM, thermal dilatometory and impedance spectroscopy. Chemical reactivity of Ca3Co4O9-d with electrolyte indicated good compatibility with CGO against generating impunity phase CaZrO3 with YSZ. Thermal expansion coefficient of pure Ca3Co4O9-d exhibited 10.0-11.0×10-6 K-1, which is similar to that of CGO electrolyte. Indeed, we verified a good adherence between electrode thin layer and the electrolyte. Electrochemical property of Ca3Co4O9-d pellet showed good performances, i.e. ASR values are 3.0 and 24.5 Ωcm2 at 700 and 600 ºC in ambient air respectively, in our experimental conditions.