Preparation of high-performance multiphase heterostructures IT-SOFC cathode materials by Pr-induced in situ assembly

Abstract

Here, in situ assembly in La0.6Sr0.4Co0.2Fe0.8O3-δ and CoFe2O4 composite (LSCFC) cathode was induced by Pr to form La0.6Sr0.4CoxFeyO3-δ/PrCoO3/Co3O4/PrO2 (LSCFC-PI) multiphase heterostructures. The surface of LSCFC-PI forms uniform nanoparticles, and the unique core-shell structure prevents Sr segregation, thereby enhancing CO2 tolerance and increasing oxygen reduction reaction (ORR) active sites. Furthermore, compared with LSCFC, LSCFC-PI increases the oxygen vacancy content of the cathode due to the existence of multiphase heterostructure, improves the ORR kinetics, and the conductivity is also greatly improved. The peak power density (PPD) of LSCFC-PI as a single-cell cathode at 700 ℃ reached 1.51 W cm−2, which was 2.65 times higher than that of LSCFC's 0.57 W cm−2, and in the long-term stability test at a constant voltage ∼0.8 V for 100 hours, showing excellent stability. In situ assembly of multiphase heterostructures is expected to become a new strategy for developing high-performance IT-SOFC cathodes.