Al2O3 Toughening ScSZ Electrolyte Fabricated by Water-Based Tape Casting Technique for Solid Oxide Fuel Cells

Abstract

A water-based tape casting slurry is reported to prepare the ceria and scandia co-doped zirconia (ScSZ) electrolyte films. The slurry is characterized and optimized through Zeta potential and rheological property measurements. Smooth and flat ScSZ electrolyte films are obtained by improving the sintering process. The microstructure, electrical performance, and mechanical property of ScSZ with adding different contents of Al₂O₃ are also investigated. The results show that a proper amount of Al₂O₃ has a beneficial effect on the densification of ScSZ. Significant decrease at the grain boundary resistance of ScSZ is observed by Al₂O₃ addition. The bending strength of the sample with 0.5 wt.% Al₂O₃ (ScSZ-0.5A) is about 400 MPa, which is 20% higher than pure ScSZ. The ScSZ-0.5A electrolyte film fabricated by water-based tape casting method shows appropriate electrical conductivity and high mechanical strength, which is promising for the practical application in solid oxide fuel cells (SOFCs).