Characterization of Nd[sub 1−x]Sr[sub x]CoO[sub 3−δ] (0≤x≤0.5) Cathode Materials for Intermediate Temperature SOFCs

The crystal chemistry, thermal expansion behavior, electrical conductivity, chemical compatibility, and electrochemical performance in intermediate temperature solid oxide fuel cells (SOFCs) of perovskite oxides have been investigated. The samples crystallize in an orthorhombic structure, and the lattice volume increases with increasing Sr content, The thermal expansion coefficient decreases with reaches a minimum at and then increases. The electrical conductivity increases with and the system exhibits a semiconductor-to-metal transition at around The electrocatalytic activity and power density increase with increasing reaches a maximum around and then decreases due to an interfacial reaction of the sample with the electrolyte. The sample shows a maximum power density value of at 800°C in single cells fabricated with the electrolyte and cermet anode. © 2004 The Electrochemical Society. All rights reserved.