An electrolyte for an electrolyte-supported high-temperature fuel cell, method for its production, its use for an electrolyte-supported fuel cell and use of the fuel cell for a fuel cell stack

摘要

An electrolyte for an electrolyte-supported high-temperature fuel cell, characterized in that the electrolyte comprises zirconium (IV) oxide doped with 4.6 to 5.5 mol% ytterbium (III) oxide, the grains of the zirconium (IV) oxide after sintering have a visible diameter in a thermally etched transverse section of an electron micrograph of less than or equal to 2.0 microns and the electrolyte has a thermal expansion coefficient TEC (T1, T2) = [1 / L (T1)] · [L (T2 ) - L (T1)] / [T2-T1], where T1 = 30 ° C and T2 = 800 ° C, at 800 ° C in the range of 10.6 · 10-6 K-1 to 11.1 · 10-6 K-1 and the surface resistivity of the electrolyte-supported cell ≤ 0.4 Ωcm2.