(JP6103988-A)      The fuel cell comprises a solid electrolyte portion as the ion conductor contg. 1-15 atom% of at least one of the metal atoms, Mn, Fe, Co, Ni, Cu and Zn.    USE -   The cell has an air-tight solid electrolyte. It can be made thin without fuel leakage.    (JP6103989-A)      The fuel comprises a solid electrolyte portion as the ion conductor, provided as a spray coating, 40-100 microns thick. It has a nitrogen gas leakage of 10power(-5) cc/g.sec. or lower.    USE -   Single cell has high electromotive force.    (JP6103991-A)      Solid electrolyte film is made by thermal spraying a mixed powder comprising solid electrolyte material powder having mean size of 10-40 microns, and cpd. of at least one of Mn, Fe, Co, Ni, Cu and Zn, to have the ratio of at least one of the metals over the total metal atoms in the mixed powder of 1-15 at.%, followed by heat treating the obtd. thermal sprayed film at 1350-1500 deg.C.    Solid electrolyte fuel cell is made by forming the air-tight solid electrolyte film on one electrode, and forming the other electrode on the solid electrolyte film.    USE -   Used for making solid electrolyte fuel cells having high-air-tightness solid electrolyte film.    (EP588632-B1)      A solid oxide fuel cell (SOFC) has a solid electrolyte portion formed by a spraying method as an ion conductor, a thickness of the solid electrolyte portion is 40-100 micro m, and a leakage amount of N2 gas of the solid electrolyte portion at room temp is less than 10 power-5 cc/g sec.    A process for producing a solid electrolyte film and a process for producing a SOFC are also claimed.    USE/ADVANTAGE -   Solid oxide fuel cells. A process for producing solid electrolyte films, and for producing SOFCs using the films. suitable for mass production. SOFC single cell has an open circuit voltage near theoretical, and a reduced internal resistance. The solid electrolyte film has improved gas tightness in thin sections giving improved output. Heat treatment of the sprayed film is at a relatively low temp.    In an example, a powder of lanthanum manganite was pressed to form a disc shape 50 mm dia x 3 mm thick, and sintered 1550 deg.C, 5 hrs. The sintered body was processed to provide an air electrode substrate having 22% porosity. A powdery raw material consisting of a stabilised zirconia contg 8 mol% of Y2O3, and a powdered additive of MnO2, was supplied to a spray gun. The molten mixt from the spray gun was sprayed onto a surface of the air electrode substrate to obtain a sprayed film 600 microns thick. The sprayed film was heat treated 1450 deg.C. 5 hrs to obtain a solid electrolyte film. Tests conducted on the film produced in a range of thicknesses showed a leakage amount is less than 10 power-5 cc/g sec when the thickness is greater than micro m, an open circuit voltage 1.10 V, and reduced internal resistance.