Structural, Electrical, and Electrochemical Characteristics of LnBa0.5Sr0.5Co1.5Fe0.5O5+δ (Ln=Pr, Sm, Gd) as Cathode Materials in Intermediate‐Temperature Solid Oxide Fuel Cells

Abstract

AbstractLayered perovskite oxides have received great attention as prospective cathode materials for intermediate‐temperature solid oxide fuel cells (IT‐SOFCs) because of their high electrical conductivities and fast oxygen kinetics. Herein, we focus on the structural, electrical, and electrochemical properties of layered perovskites LnBa0.5Sr0.5Co1.5Fe0.5O5+δ (LnBSCF, Ln=Pr, Sm, and Gd) as a cathode material for IT‐SOFCs. Among the evaluated perovskites, PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF) showed the highest electrical conductivity, the highest oxygen content, and the highest values of the oxygen bulk diffusion coefficient (D*) and surface exchange coefficient (k) measured by using isotope oxygen exchange. The composite cathode of PBSCF and gadolinium‐doped ceria is the most suitable cathode material for IT‐SOFCs among the materials investigated because of its excellent electrochemical properties and fast oxygen kinetics.