| 초록 |
As a cathode material of intermediate-temperature solid oxide fuel cell (IT-SOFC), layered perovskite oxides have received considerable attention due to their high electrical conductivities and fast oxygen kinetics. In this study, characteristics of LnBa0.5Sr0.5Co1.5Fe0.5O5+δ(Ln = Pr, Sm, and Gd) are investigated in terms of structural, electrical and electrochemical properties as an IT-SOFC cathode material. The maximum power densities of PrBa0.5Sr0.5Co1.5Fe0.5O5+δ(PBSCF), SmBa0.5Sr0.5Co1.5Fe0.5O5+δ(SBSCF) and GdBa0.5Sr0.5Co1.5Fe0.5O5+δ(GBSCF) were 1.02, 0.85, and 0.72 W cm-2 at 973 K, respectively. These difference could be explained by oxygen kinetics of each cathode materials based on the oxygen bulk diffusion coefficient (D*) and surface exchange coefficient (k). As a result, PBSCF is the best cathode material for IT-SOFCs due to its high electrochemical performances and fast oxygen. |
