Cobalt-free perovskite Ln0.5Sr0.5Fe0.8Cu0.2O3-δ (Ln = Pr, Nd, Sm, and Gd) as cathode for intermediate-temperature solid oxide fuel cell

Abstract

Ln0.5Sr0.5Fe0.8Cu0.2O3-δ (LnSFC, Ln = Pr, Nd, Sm, Gd) perovskite oxide as a cobalt-free cathode was systematically evaluated for intermediate-temperature solid oxide fuel cell (IT-SOFC). XRD results show that PrSFC presents the cubic structure, while NdSFC, SmSFC, and GdSFC present an orthorhombic structure. The conductivity of the four samples is in accordance with the GdSFC < SmSFC < NdSFC < PrSFC relationship. AC impedance testing was performed using a symmetrical fuel cell of the structure LnSFC/Ce0.9Sm0.1O1.95(SDC)/LnSFC. The polarization resistance values of PrSFC, NdSFC, SmSFC, and GdSFC are 0.036, 0.089, 0.097, and 0.160 Ω cm2 at 800 °C, respectively. Then, SDC electrolyte-support single cell was fabricated and the power densities of PrSFC, NdSFC, SmSFC, and GdSFC cathodes were 364, 311, 254 and 104 mW cm−2, respectively, at 800 °C. Our preliminary experiment results show that LnSFC oxide meets the requirements of the electrode, and it can be a possible cathode for IT-SOFC.