Process for producing a solid electrolyte layer on a substrate, in a fuel cell, and in a sensor

A method for producing a solid electrolyte layer, of a fully stabilized zirconium oxide layer on a substrate, which comprises:

• applying a zirconium oxide starting material to the substrate together with a sintering additive as a green layer;
• forming a liquid phase of the sintering additive by subsequently heating the sintering additive;
• and
• densifying the green layer to form a densified layer with a liquid-phase sintering operation at a reduced sintering temperature compared to a sintering temperature required without the sintering additive, in which operation process parameters, including at least one of heating rate, sintering temperature, and holding time, are selected to cause the liquid phase to still be present when the reduced sintering temperature is reached and to cause the densified layer to be substantially free of the sintering additive, the reduced sintering temperature being higher than a sintering temperature required for a sintering operation with sintering additive.

A method for producing a solid electrolyte layer, of a fully stabilized zirconium oxide layer on a substrate, which comprises:

• applying to the substrate:
• a zirconium oxide starting material as a green layer with the sintering additive;
• and
• a zirconium oxide starting material as a green layer without the sintering additive;
• forming a liquid phase of the sintering additive by subsequently heating the sintering additive;
• and
• densifying the green layer with a liquid-phase sintering operation at a reduced sintering temperature compared to a sintering temperature required without the sintering additive.