Fuel electrodes for solid oxide fuel cells and production thereof

Abstract

A fuel electrode for solid oxide fuel cells, which is to be provided on a surface of an ion-conductive solid electrolyte body, includes a skeleton for a porous fuel electrode, and a thin filmy tissue which is composed of the same material as the solid electrolyte body, and covers the fuel electrode skeleton. Gaps are present between the thin filmy tissue and the fuel electrode skeleton. The skeleton is made of a material containing at least nickel. A process for producing fuel electrode includes the steps of: forming a porous film made of a porous skeleton containing at least nickel oxide onto a surface of an ion-conductive solid electrolyte body; covering a surface of the porous skeleton with a thin filmy tissue made of the said solid electrolyte material by impregnating the porous film with a solution of a metallic compound capable of producing the same solid electrolyte material as that of the solid electrolyte body; heating the porous film and decomposing the metallic compound; and forming a porous skeleton containing at least nickel by reducing the porous film, and forming gaps between the fuel electrode skeleton and the thin filmy tissue by a decrease in volume of the porous skeleton resulting from reduction of nickel oxide to nickel.