Enhanced and stable strontium and cobalt free A-site deficient La1-xNi0.6Fe0.4O3 (x=0, 0.02, 0.04, 0.06, 0.08) cathodes for intermediate temperature solid oxide fuel cells

Perovskite oxides with cobalt and strontium element exhibit severe degradation during the operation for the solid oxide fuel cells (SOFC). Here, we report stable non-cobalt and non strontium La1-xNi0.6Fe0.4O3 perovskite cathodes with improved oxygen reduction reaction (ORR) activity. A-site deficient La1-xNi0.6Fe0.4O3 cathodes within 8 at.% all exhibit the invariable phase structure with LaNi0.6Fe0.4O3 (LNF), and the matched thermal expansion coefficient with that of the (Ce0.90Gd0.10)O-1.95 (GDC) electrolyte. The polarization resistance of the La0.94Ni0.6Fe0.4O3 (LNF94) cathode is 0.61 Omega cm(2) at 750 degrees C in air, which is 1/5 of the LaNi0.6Fe0.4O3 (2.78 Omega cm(2)). The peak power density of the corresponding single cell with LNF94 cathode is 0.37 Omega cm(-2) at 750 degrees C, which is 2.36 times higher than that of the single cell with LNF cathode (0.11 W cm(-2)). We further study the long-term stability of LNF and LNF94 cathodes, the polarization resistance of the LNF94 electrode slightly fluctuates around 0.18 Omega cm(2) during 50 h operation at 800 degrees C, while the polarization resistance of the LNF increases by about 15%. This work highlights the A-site deficient LNF as an effective and stable non-cobalt and non-strontium cathode for the intermediate temperature solid oxide fuel cells. (C) 2021 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.

Automated summary

The study presents a stable non-cobalt and non-strontium La1-xNi0.6Fe0.4O3 perovskite cathode with improved oxygen reduction reaction activity for intermediate temperature solid oxide fuel cells.