Modified La0.6Sr0.4Co0.2Fe0.8O3-δ cathodes with the infiltration of Er0.4Bi1.6O3 for intermediate-temperature solid oxide fuel cells

Aiming to lower the activation energy and expedite the oxygen reduction reaction (ORR) process of La0.6Sr0.4Co0.2Fe0.8O3-d (LSCF) cathodes for application in intermediatetemperature solid oxide fuel cells (IT-SOFCs), Er0.4Bi1.6O3 (ESB) modified LSCF was prepared by infiltrating using organic solvents. The infiltration of ESB dramatically reduces the polarization resistances of LSCF cathodes (from 0.27 to 0.11 U cm2 at 700 degrees C, from 0.58 to 0.25 U cm2 at 650 degrees C), and lowers their activation energy (from 100.28 to 97.15 kJ mol-1). Also, ESB makes the rate-limiting step of LSCF cathodes at high frequency change from the charge transfer process on the cathode to the adsorption and diffusion of oxygen on cathode surface. The single cell with ESB infiltrated LSCF cathodes shows a peak power density of 469 mW cm-2 at 700 degrees C using humid hydrogen and air as fuels and oxidants, respectively, as well as a good short-term stability for 50 h. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.