Fabrication of apatite-type lanthanum silicate films and anode supported solid oxide fuel cells using nano-sized printable paste

Abstract

Apatite-type lanthanum silicate based films have attracted significant interests to use as an electrolyte of solid oxide fuel cells (SOFCs) working at intermediate temperature. We have prepared Mg doped lanthanum silicate (MDLS) films on NiO-MDLS cermet substrates by spin coating and sintering of nano-sized printable paste made by beads milling. Changes in crystal structure and microstructure of the paste films with the sintering temperature have been investigated to show that porous network structure with a grain growth evolves up to 1300 °C, whereas densification occurred above 1400 °C. Anode supported SOFCs using the pasted MDLS films were successfully fabricated: an open circuit voltage of 0.91 V and a maximum power density of 150 mW cm −2 measured at 800 °C were obtained with the electrolyte film sintered at 1500 °C.

Sol–gel synthesis and characterization of Zn 2+ and Mg 2+ doped La 10 Si 6 O 27 electrolytes for solid oxide fuel cells

“…Various methods to enhance the process-ability and the densification of these materials [29][30][31][32][33] have also been investigated. The variety of processing methods is partly responsible for the wide scatter in the data on conductivity values of even same compositions of the silicate apatite electrolytes [29,32,[34][35][36][37].…”

Hydrothermal synthesis of lanthanum silicate nanopowder and film preparation by electrophoretic deposition method

“…As for the powder-synthesis process, some liquid-based methods, such as a solgel method, 6)8) a coprecipitation method, 9)11) an urea-nitrates combustion, 12) a molten-salt synthesis, 13) and a hydrothermal method, 14) succeeded in a preparation of the nanopowder at relatively low temperature. Previous works also applied an alcoxide-hydrolysis method, 15) a plasma spray synthesis, 16)18) a magnetron sputtering, 19),20) a spin coating 21) and an electrophoretic deposition using powder prepared by a solgel process, 22) for a film preparation of the lanthanum silicates. In general, however, most of these processes cannot be considered as a simple process, and thus another strategy for manufacturing of the dense film electrolyte is still expected highly at the moment.…”

Chemical solution deposition of the highly c-axis oriented apatite type lanthanum silicate thin films

“…Actually, high temperature operation of SOFCs can cause several problems, such as limitations on the component materials (collector, housing, etc. 1600°C) required for sintering, [14][15][16][17][18] and the other is difficulty in the fabrication of thinner films with thicknesses of few micrometers for SOFC electrolyte applications. Therefore, new electrolyte materials have been explored to enable efficient operation at lower temperatures (<500°C).…”