Zirconium dioxide stabilized with yttrium oxide and cerium oxide (8Ce2YSZ) for solid oxide fuel cell anode and electrolyzers application

Abstract

Solid oxide fuel cells (SOFC) are among the most promising technologies for the electricity generation due to their high efficiency, reliability, flexibility in fuel selection, absence of valuable platinum group metal catalysts, safety and environmental friendliness.Typically, the SOFC is built on the basis of its anode, which is actually also its carrier. This is due to the researchers wish to minimize the ohmic resistance of the electrolyte layer via its thinning that is extremely critical for reducing SOFC operating temperature. In this regard, the anode must be strong enough both to make it easier to handle when making the whole cell and to ensure its stable operation. In addition to the carrier function, the anode shall provide sites for reacting gaseous fuel with oxygen ions, which are delivered through the electrolyte, and supplying the fuel gas components to the reaction sites and removing the fuel oxidation reaction products to the outside.The work deals with the comparative study of ceramic materials based on ZrO2, co-stabilized with CeO2 and Y2O3, and stabilized with Y2O3to be used in producing the SOFC anode, and for further structural optimization for future SOFCs.8Ce2YSZ ceramic samples made by hydrothermal synthesis (with two different modes of drying precipitation) have tetragonal phase and 6—8% residual porosity. The 8Ce2YSZ samples, showed the biaxial bending strength — 542 MPa and 486 MPa, respectively. The 8YSZ and 3YSZ samples have cubic phase with a strength of 181 MPa and tetragonal phase with a strength of 577 MPa, respectively at 1% porosity.The specific electrical conductivity of 8Ce2YSZ and 8YSZ is 1,1•10-3, 4•10-3 S/cm, 1,2•10-2 S/cm and 5,2•10-3, 2,7•10-2 S/cm, 9,3•10-2 S/cm at 600, 700, 800 °C, respectively. Keywords: solid oxide fuel cell, electrolyte, anode, zirconium dioxide, mechanical strength, ionic conductivity.