Influences of equal A-site rare-deficiency or B-site high-valent metal doping on NdBaFe2O employed as the symmetrical electrode for solid oxide fuel cells

Symmetric solid oxide fuel cells (SSOFCs), which can effectively deal with the issue of anode carbon accumulation and sulfur poisoning while simplifying the preparation process, have received much attention. Fe-based compounds are commonly used as symmetric electrodes for SOFCs, due to their low cost and excellent stability. The effects of equivalent quantities of Nd-deficiency or Mo-doping on NdBaFe2O5+δ (NBF) electrode materials for SOFCs are investigated in this work. Under hydrogen atmosphere, NBF has the highest electrical conductivity, while also containing the biggest amount of oxygen species both before and after reduction, showing outstanding electrocatalytic activity for both hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR). A laboratory-scale YSZ electrolyte-supported cell with an NBF95 electrode is fabricated and obtains a maximum power density of 366.66 mW·cm-1 at 800 °C. The results show that either Nd-deficiency or Mo-doping can enhance the electrochemical performance of the NBF electrode, and the advantage of Nd-deficiency is more significant.