Method for forming fuel electrode of solid oxide fuel cell and solid electrolyte fuel cell using the fuel electrode

摘要

PURPOSE:To suppress grain growth of electrolyte in a fuel electrode during baking process and heighten the oxygen ion electroconductivity in the neighborhood of the interface of the center layer by keeping a specific metal oxide out of doping at first, and allowing it to diffuse from the central solid electrolyte layer at the time of baking. CONSTITUTION:A specific bivalent or trivalent metal oxide (yttrium etc.) for increasing the electroconductivity is turned in solid solution at each side of a solid electrolyte layer 1 as the center of a fuel cell, in which an air electrode 3 and a fuel electrode 2 consisting of thermet of this solid electrolyte with a specific metal (nickel, etc.) are arranged. Examples of the crude material for the solid electrolyte in the fuel electrode 2 are salts containing a specific tetravalent metal (zirconium, etc.) and a powder of specific tetravalent metal oxide (zirconium oxide, etc.), and the yttrium oxide, etc., is turned in solid solution by diffusion from the solid electrolyte layer 1 at the time of baking the fuel electrode 2. This enables suppressing grain growth of the electrolyte and reducing polarization in the neighborhood of the interface 4.