Solid electrolyte film, solid oxide fuel cell comprising such a solid

Abstract

A solid electrolyte film being formed on a substrate by plasma spraying. The solid electrolyte film has a solid electrolyte structure composed of cerium oxide or zirconium oxide stabilized or partially stabilized with an alkaline earth metal element and/or a rare earth element. The solid electrolyte film has a true porosity of not more than 5%. A solid oxide fuel cell is also disclosed, which involves such a solid electrolyte film being formed on the substrate by plasma spraying, an air electrode provided on one side of the solid electrolyte films and a fuel electrode provided on the other side of the solid electrolyte film. The solid electrolyte film is formed on the substrate by densifying a plasma sprayed solid electrolyte raw film by heating the film in a temperature range of 1,300.degree. to 1,700.degree. C. In the cell, the fuel electrode film or the air electrode is formed onto a surface of the solid electrolyte film.