Studies on solid electrolytes for a new-type SOFC using methane-air mixture

In order to find out a suitable electrolyte for a new-type SOFC (one chamber with methane - air mixture), YSZ (8 mol% Y2O3) doped with TiO2 was tested as a solid electrolyte. In the case of nondoped YSZ, the open - circuit voltage of the cell decreased with time, and the electric power density was extremely smaller than the value obtained in a conventional SOFC using YSZ as a solid electrolyte. However, in the case of YSZ doped with TiO2 (5 mol%), the electric power density was about 6 times higher than that in the case of YSZ only although the terminal voltage of the cell slightly decreased with time. This was based on the difference in cathodic polarization and transitional change in the potential between these electrolytes.