Thin Film (La_0.7Sr_0.3)_0.95MnO_3-δFabricated by Pulsed Laser Deposition and Its Application as a Solid Oxide Fuel Cell Cathode for Low-Temperature Operation

Abstract

The feasibility of using the thin film technology in utilizing lanthanum strontium manganite (LSM) for a solid oxide fuel cell (SOFC) cathode in a low-temperature regime is investigated in this study. Thin film LSM cathodes were fabricated using pulsed laser deposition (PLD) on anode-supported SOFCs with yttria-stabilized zirconia (YSZ) electrolytes. Although cells with a 1 µmthick LSM cathode showed poor low-temperature cell performance compared to that of a cell with a bulk-processed cathode due to the lack of a triple-phase boundary length, the cell with 200 nm-thick gadolinia-doped ceria (GDC) inserted between the LSM and YSZ showed enhanced performance and more stable operation characteristics in a comparison of a cell without a GDC layer. We postulate that the GDC layer likely improved the cathode adhesion, therefore contributing to the improvement of the cell performance instead of serving as an interfacial reaction buffer.

Suppressing Lateral Conduction Loss of Thin-film Cathode by Inserting a Denser Bridging Layer

“…It has been reported that the resistance associated with lateral electronic transport in the cathode is commonly smaller than other resistances from oxygen ion diffusion, and especially smaller than the resistance from the oxygen reduction reaction (ORR). [8][9][10] However, with the improved performance due to the application of nanostructures, the resistance from ion diffusion and ORR are significantly reduced and the proportion of the sheet resistance increases in the total resistance. The sheet resistance of a thin-film cathode is inversely proportional to the thickness of the film; thus, it is possible to reduce the sheet resistance by increasing the thickness of the cathode.…”