Development of Monolithic YSZ Porous and Dense Layers through Multiple Slip Casting for Ceramic Fuel Cell Applications

Authors


  • This research was financially supported through funding to the NSERC Solid Oxide Fuel Cell Canada Strategic Research Network from the Natural Sciences and Engineering Research Council (NSERC) and other sponsors listed at http://www.sofccanada.com.

Abstract

In this research YSZ porous support and thin dense functional electrolyte layers are fabricated via a slip-casting method for fuel cell applications. The results show that calcination of YSZ starting powder is a crucial step in developing an effective porous structure having an interconnected void network for fuel cell applications. It is found that due to high surface area and high sinterability, as-received Tosoh YSZ powder is not a suitable candidate for production of interconnected porous structures even with the addition of pore former. Calcination at 1300–1500°C coarsens the YSZ powder and leads to the growth of particles to 15–100 μm. However, subsequent ball milling of the calcined powder for 72 h reduces the particle size to 400–800 nm (∼240 nm for uncalcined Tosoh YSZ) and increases the subsequent surface area, correlating with the temperature of calcination. With high-temperature calcination, it is possible to generate interconnected porous structures after sintering at temperatures lower than the calcination temperature. The bodies made of powder calcined at 1300°C become dense following sintering at 1350°C, which makes this material suitable as a dense fuel cell electrolyte. Using calcined powders, a multiple slip-casting procedure enables a dense electrolyte to be coated directly on a highly porous support. With this simple and inexpensive technique, high-quality strongly adhered YSZ layers can be engineered.

Ancillary