Fabrication and electrochemical characterization of SOFC single cell with 6Yb4ScSZ electrolyte powder by tape-casting and co-sintering

Abstract

Nanocrystalline Yb-doped scandia-stabilized zirconia (6Yb4ScSZ) powders are prepared using co-precipitation process. The effects of calcination treatments on factors such as phase evolution, crystallite size, and specific surface area are investigated. The synthesized electrolyte powders have a high specific area of 25 m² g⁻¹, nanocrystalline size of 17 nm and ionic conductivity of 0.7 S cm⁻¹ at 800°C with a cubic structure. Solid oxide fuel cell (SOFC) with anode-supported electrolyte, in which the electrolyte layer consists of nanocrystalline 6Yb4ScSZ powders calcined at 850°C, is fabricated by tape casting and co-sintering. The open-circuit voltage of the SOFC single cell is approximately 1.07 V at 800°C, indicating negligible leakage of fuel through the electrolyte layer. As a result, power density of 1.30 W cm⁻² is obtained at 2.0 A cm⁻² and 800°C due to the drastic reduction of ohmic resistance in the SOFC cell.