Perovskite-type Nd_0.75Ba_0.25Co_0.8Fe_0.2O_3-δ cathode for intermediate temperature solid oxide fuel cells

Perovskite-type Nd_0.75Ba_0.25Co_0.8Fe_0.2O_3-δ (NBCF25) was prepared via solid-state synthesis method at 1300 °C in air. Powder X-ray diffraction showed the formation of a single-phase orthorhombic phase in the Pnma space group. It showed minor reactivity with Sr and Mg-co-doped lanthanum gallate (LSGM) when sintered with 30 wt.% LSGM at 1050 °C. 4-probe DC chronopotentiometry measurements were performed on the sintered sample pellets and showed a maximum conductivity of 674 S/cm at 700 °C. 2-probe AC electrochemical impedance spectroscopy measurements were performed on LSGM pellets from 650 to 800 °C to investigate the oxygen reduction property of NBCF25 using a composite slurry (70 wt.% NBCF and 30 wt.% LSGM). It showed the lowest area-specific resistance of 0.07 Ω cm² at 800 °C in air. Impedance spectroscopy genetic programming was used to understand the oxygen reduction reaction.