Ni-Sm 2O 3 cermet anodes for intermediate-temperature solid oxide fuel cells with stabilized zirconia electrolytes

Abstract

Ni-LnO x cermets (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd), in which LnO x is not an oxygen ion conductor, have shown high performance as the anodes for low-temperature solid oxide fuel cells (SOFCs) with doped ceria electrolytes. In this work, Ni-Sm 2O 3 cermets are primarily investigated as the anodes for intermediate-temperature SOFCs with scandia stabilized zirconia (ScSZ) electrolytes. The electrochemical performances of the Ni-Sm 2O 3 anodes are characterized using single cells with ScSZ electrolytes and LSM-YSB composite cathodes. The Ni-Sm 2O 3 anodes exhibit relatively lower performance, compared with that reported Ni-SDC (samaria doped ceria) and Ni-YSZ (yttria stabilized zirconia) anodes, the state-of-the-art electrodes for SOFCs based on zirconia electrolytes. The relatively low performance is possibly due to the solid-state reaction between Sm 2O 3 and ScSZ in fuel cell fabrication processes. By depositing a thin interlayer between the Ni-Sm 2O 3 anode and the ScSZ electrolyte, the performance is substantially improved. Single cells with a Ni-SDC interlayer show stable open circuit voltage, generate peak power density of 410 mW cm −2 at 700 °C, and the interfacial polarization is about 0.7 Ω cm 2.