Wet atomisation of Gd-doped CeO₂ electrolyte slurries for intermediate temperatures microtubular SOFC applications

A wet atomising system has been employed as a novel method to prepare ultrafine Gd-doped CeO₂ (GDC) electrolyte slurries. By changing the fluid flow pressure and repeating the atomisation process several times for the same atomised slurries, we have obtained optimised ultrafine GDC slurry with high-dispersed and homogeneous distribution. The sizes of the particles of GDC were in the range of tens of nanometres. A highly dense electrolyte layer (membrane) was prepared using the ultrafine GDC slurries for intermediate temperatures microtubular solid oxide fuel cell (SOFC) applications. The SOFC was fabricated by using supporting porous anode tubes of NiO and GDC, and the cathode consisted of La_0.6Sr_0.4Co_0.2Fe _0.8O_3-y and GDC. A dense 10 lm GDC electrolyte layer was obtained at a lower sintering temperature of 1,250 °C for 1 h. The SOFC was tested with humidified (3% H₂O) hydrogen as a fuel and the static air as an oxidant, and the tubular cell maintained its high performance even at 500 °C.