Influence of Bi1.5Y0.5O3 Active Layer on the Performance of Nanostructured La0.8Sr0.2MnO3 Cathode

Abstract

The efficiency of solid oxide fuel cell cathodes can be improved by microstructural optimization and using active layers, such as doped bismuth oxides. In this work, Bi1.5Y0.5O3 (BYO) films are prepared by spray-pyrolysis deposition at reduced temperatures on a Zr0.84Y0.16O1.92 (YSZ) electrolyte. The influence of the BYO film on the performance of an La0.8Sr0.2MnO3 (LSM) cathode prepared by traditional screen-printing and spray-pyrolysis is investigated. A complete structural, morphological, and electrochemical characterization is carried out by X-ray diffraction, electron microscopy, and impedance spectroscopy. The incorporation of BYO films decreases the Area Specific Resistance (ASR) of screen-printed cathodes from 6.4 to 2.2 Ω cm2 at 650 °C. However, further improvements are observed for the nanostructured electrodes prepared by spray-pyrolysis with ASRs of 0.55 and 1.15 Ω cm2 at 650 °C for cathodes with and without an active layer, respectively. These results demonstrate that microstructural control using optimized fabrication methods is desirable to obtain high-efficiency electrodes for solid oxide fuel cell (SOFC) applications.

High ionic conductivity in fluorite δ-bismuth oxide-based vertically aligned nanocomposite thin films

“…Indeed, erbium stabilised d-Bi 2 O 3 -La 1Àx Sr x MnO 3 (LSM) composite cathodes have been gaining interest in bulk powder SOFCs, pairing the superb ionic conductivity of the uorite d-Bi 2 O 3 with the high electronic and cathodic performance of LSM, resulting in low areal surface resistances. [24][25][26][32][33][34] We also draw attention to analogous VAN nanocomposite structures recently reported utilising the same electronic-ionic pairing philosophy. 18 Hence, the DSB-DMO VAN reported here could serve as a precursor to a d-Bi 2 O 3 based VAN cathodes.…”

Recent progress in nanostructured electrodes for solid oxide fuel cells deposited by spray pyrolysis

“…Zamudio et al have prepared active interlayers of the fast-ionic conductor Bi1.5Y0.5O3- (BYO) by CSD [176]. The incorporation of a BYO interlayer between YSZ electrolyte and LSM cathode decreased the resistances of both high-and low-frequency contributions of the impedance spectra, suggesting that the active layer not only improved the charge transfer at the electrolyte interface but also extended the surface path of the electrochemical reaction sites.…”

Performance Enhancement of Ce0.8Sm0.2O1.9-Supported SOFC by Electrophoretic Formation of Modifying BaCe0.8Sm0.2O3 and Ce0.8Sm0.1Pr0.1O1.9 Layers

“…Therefore, the development of electrodes that are highly active in the IT range and compatible with CeO 2 and BaCeO 3 electrolytes is of great importance [ 30 , 31 , 32 ]. The rate of oxygen reduction reaction (ORR) at the cathode can be increased using cathode sublayers possessing higher ionic conductivity compared to the parent electrolyte, for example, doped Bi 2 O 3 electrolytes [ 33 , 34 ] or those with mixed oxygen ion and p -type electron conductivity [ 35 , 36 , 37 , 38 ]. For example, mixed valence Pr 3+/4+ used as a co-dopant was found to induce partial electronic conductivity in Gd-doped CeO 2 in an air atmosphere, increasing the grain boundary conductivity by about two orders compared to the base solid solution [ 39 , 40 ].…”