Electrochemical Activity of Original and Infiltrated Fe-Doped Ba(Ce,Zr,Y)O3-Based Electrodes to Be Used for Protonic Ceramic Fuel Cells

Abstract

Proton-ceramic fuel cells (PCFCs) are promising devices for electrochemical energy conversion purposes due to their combination of high energy efficiency, environmental friendliness, and high durability. In the present work, the polarization characteristics of promising electrodes for PCFCs based on BaFexCe0.7–xZr0.2Y0.1O3–δ (BCZYFx) are comprehensively studied. Along with the individual BCZYFx electrodes, we investigated a method for improving their electrochemical activity by introducing nanoparticles of PrOx electrocatalysts into the porous structure of the electrode material. According to the experimental data, electroactivation allowed for the polarization resistances of the electrodes at 700 °C to be reduced from 1.16, 0.27, 0.62 Ω°cm2 to 0.09, 0.13, 0.43 Ω°cm2 for x = 0.5, 0.6, and 0.7, respectively. For a PCFC cell with an air electrode of BCZYF0.6 composition activated using PrOx nanoparticles, it was possible to achieve a maximum specific power of 300 mW cm–2 at 750 °C, which is competitive for a single cell with Co-free cathodes. The results obtained provide insight into the processes occurring in the studied electrodes after electroactivation. It is shown how the improvement of electrochemical characteristics of the electrode can be realized by a simple infiltration method in combination with a subsequent thermal treatment.

Chemical stability aspects of BaCe0.7–xFexZr0.2Y0.1O3–δ mixed ionic-electronic conductors as promising electrodes for protonic ceramic fuel cells

“…Zirconium and yttrium, considered as strong acids, form the strongest metal-oxygen bonds, thus stabilizing barium ferrite-based materials effectively [26,27]. Recently, we provided a detailed analysis on the preparation of BaCe0.7-xFexZr0.2Y0.1O3-δ materials [28] as well as their application as air electrodes for PCFCs [29] and oxygen permeation membranes [30]. These works show a great promise of the designed materials in terms of their electrochemical properties.…”