Triple Perovskite Nd(1.5)Ba(1.5)CoFeMnO(9−δ)-Sm(0.2)Ce(0.8)O(1.9) Composite as Cathodes for the Intermediate Temperature Solid Oxide Fuel Cells

Triple perovskite has been recently developed for the intermediate temperature solid oxide fuel cell (IT-SOFC). The performance of Nd(1.5)Ba(1.5)CoFeMnO(9−δ) (NBCFM) cathodes for IT-SOFC is investigated in this work. The interfacial polarization resistance (R(P)) of NBCFM is 1.1273 Ω cm(2)~0.1587 Ω cm(2) in the range of 700–800 °C, showing good electrochemical performance. The linear thermal expansion coefficient of NBCFM is 17.40 × 10(−6) K(−1) at 40–800 °C, which is significantly higher than that of the electrolyte. In order to further improve the electrochemical performance and reduce the thermal expansion coefficient (TEC) of NBCFM, Ce(0.8)Sm(0.2)O(2−δ) (SDC) is mixed with NBCFM to prepare an NBCFM-xSDC composite cathode (x = 0, 10, 20, 30, 40 wt.%). The thermal expansion coefficient decreases monotonically from 17.40 × 10(−6) K(−1) to 15.25 × 10(−6) K(−1). The surface oxygen exchange coefficient of NBCFM-xSDC at a given temperature increases from 10(−4) to 10(−3) cm s(−1) over the [Formula: see text] range from 0.01 to 0.09 atm, exhibiting fast surface exchange kinetics. The area specific resistance (ASR) of NBCFM-30%SDC is 0.06575 Ω cm(2) at 800 °C, which is only 41% of the ASR value of NBCFM (0.15872 Ω cm(2)). The outstanding performance indicates the feasibility of NBCFM-30% SDC as an IT-SOFC cathode material. This study provides a promising strategy for designing high-performance composite cathodes for SOFCs based on triple perovskite structures.