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

With the aim of application for IT-SOFC cathode, two dimensional (2D) misfit layered calcium cobalt oxide Ca3Co4O9-delta was studied using XRD, SEM, thermal dilatometer, and impedance spectroscopy. Chemical reactivity of Ca3Co4O9-delta with electrolyte indicated good compatibility with CGO against generating impunity phase CaZrO3 with YSZ. Thermal expansion coefficient of pure Ca3Co4O9-delta exhibited 10.0-11.0 x 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-delta pellet showed good performances, i.e. ASR values are 3.0 and 24.5 Omega.cm(2) at 700 and 600 degrees C in ambient air respectively, in our experimental conditions.