Electrolyte-cathode assembly for a fuel cell

Claim 1

An electrolyte-cathode assembly for a solid electrolyte fuel cell suitable for operation at high temperatures, which assembly comprises a gas-tight body made of a solid ceramic electrolyte capable of conducting oxygen ions, and at least one layer of an electron-conducting material in contact with the electrolyte and deposited thereon, wherein said layer of electron-conducting material is a compact layer having a thickness of at least 1 micron and at most 200 microns and made of a mixture containing from 20 to 80% by volume of indium oxide In 2 O 3 doped with tin oxide, the remainder being a ceramic material capable of conducting oxygen ions at the cell operating temperature and which is a mixed oxide solid solution, crystallized in the cubic system, consisting essentially of zirconium oxide ZrO 2 and at least one oxide stabilizing the cubic phase of zirconium oxide, said layer being covered by a compact surface layer having a thickness of at least 1 micron and at most 10 microns of ceramic material capable of conducting electrons and oxygen ions and which is a mixed oxide solid solution crystallized in the cubic system, consisting essentially of (1) zirconium oxide ZrO 2 , (2) at least one oxide stabilizing the cubic phase of zirconium oxide and (3) uranium oxide UO 2 .