A free-cobalt barium ferrite cathode with improved resistance against CO_2 and water vapor for protonic ceramic fuel cells

摘要

The triple conducting (electron, oxygen-ion and proton) cathode is promising for protonic ceramic fuel cells (PCFCs). Heavy doping of Fe can impel BaZr0.9Y0.1O3-delta & nbsp;to cross the electronic percolation threshold, forming the triple-conducting BaFe0.8Zr0.1Y0.1O3-delta & nbsp;(BFZY) material. The partial A-site substitution with La is also designed to further optimize the properties of BFZY. Herein, a systematic study on Ba0.95La0.05Fe0.8Zr0.1Y0.1O3-delta & nbsp;(BLFZY) cathode is conducted for searching potential free-cobalt PCFC cathodes with good tolerance for both CO2 and water vapor. The XRD result indicates that BLFZY maintains stable cubic perovskite structure. The comprehensive analysis based on XRD, TG and TPD-CO2 & nbsp;reveals that the BLFZY cathode exhibits an excellent tolerance for CO2 & nbsp;and water vapor. The La doping also has a positive influence on the thermal expansion coefficient, electrical conductivity, and electrocatalytic activity. The anode-supported single cell with single-phase BLFZY cathode achieves a peak power density of 305 mW cm(-2) and polarization resistance of 0.492 omega cm(2) at 600 ?& nbsp;and maintains steady power output in the short-term durability test. This indicates that the BLFZY material is a good cathode candidate for PCFCs. (C)& nbsp;2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.