P. Nikolopoulos

Gadolinia-doped ceria and yttria stabilized zirconia interfaces: regarding their application for SOFC technology ☆

Abstract For solid oxide fuel cells (SOFCs) operating at intermediate temperatures the adjacency of the state-of-the-art yttria-stabilized zirconia (YSZ) electrolyte with ceria-based materials to both anodic and cathodic sides is regarded as crucial for the effectiveness of the cell. Solid-state reaction, however, and interdiffusion phenomena between YSZ and ceria-based materials can cause degradation of the electrolyte. When a gadolinia-doped-ceria (GDC) layer is used to protect YSZ against interaction with Co-containing cathodes, an unfavorable solid state reaction at the YSZ–GDC interface can be efficiently suppressed when a thin (≤1 μm thick) interlayer with nominal composition of Ce 0.43 Zr 0.43 Gd 0.10 Y 0.04 O 1.93 is incorporated at the interface. When ceria is to be employed at the electrolyte–anode interface to reduce polarization losses, use of a ceria–40% vol Ni cermet is recommended, since suppression of the reactivity between YSZ and ceria can also be achieved in the presence of Ni.

Surface, grain-boundary and interfacial energies in Al2O3 and Al2O3-Sn, Al2O3-Co systems

AbstractUsing the multiphase equilibrium method for the measurement of contact angles, the surface and grain-boundary energies of polycrystalline Al2O3 in the temperature range of 1473 to 1923 K were determined. Linear temperature functions were obtained by extrapolation for both quantities between absolute zero and the melting point of Al2O3. The temperature dependence of the surface and grain boundary energies can be expressed as

Wettability and interfacial energies in SiC-liquid metal systems

\gamma _{{\rm A}l_2 O_3 } = 2.559 - 0.784 \times 10^{ - 3} T(J m^{ - 2} )

5 mol% TiO2-doped Ni–YSZ anode cermets for solid oxide fuel cells

and

Work of adhesion in ZrO2-liquid metal systems

\gamma _{{\rm A}l_2 O_3 - Al_2 O_3 = } 1.913 - 0.611 \times 10^{ - 3} T(J m^{ - 2} )

Wettability and interfacial energies between zirconia ceramic and liquid metals

respectively. The interfacial energies of Al2O3 in contact with the molten metals tin and cobalt revealed a linear dependence on temperature.