A new cobalt-free proton-blocking composite cathode La_2NiO_(4+δ)-LaNi_(0.6)Fe_(0.4)O_(3-δ) for BaZr_(0.1)Ce_(0.7)Y_(0.2)O_(3-δ)-based solid oxide fuel cells

摘要

Series of proton-blocking La_2NiO_(4+δ)(LNO)-LaNi_(0.6)Fe_(0.4)O_(3-δ) (LNF) (1:0, 7:3,5:5,3:7,0:1 wt.%) composites were evaluated as cathodes for BaZr_(0.1)Ce_(0.7)Y_(0.2)O_(3-δ) (BZCY)-based proton-conducting solid oxide fuel cell (H-SOFC). The X-ray diffraction (XRD) results show a good chemical compatibility for each composition below 1100 ℃. Electrochemical studies reveal that LNO-LNF73 shows the lowest area specific polarization resistance in symmetrical cells and the best electrochemical performance in single cell tests with the highest maximum power density (MPD) and the lowest interfacial polarization resistance (R_p). These results corroborate the electrical conductivity analysis. The single cell with LNO-LNF73 as cathode outputs the MPD of 590 mW cm~(-2) and the R_p of 0.091 Ω cm~2 at 700 ℃ This work confirms that LNO -LNF73 composite material could be a promising cathode for H-SOFC.