Solid Oxide Fuel Cell Employing a New Class of Solid Electrolytes, La9.33+x(Si6−yAly)O26+1.5x−0.5y

Dense and high oxide ion conducting solid electrolytes, Al-doped lanthanum silicate [La9.33+x(Si6−yAly)O26+1.5x−0.5y] were fabricated and their electrical conducting properties were studied. Among the specimens tested, the electrical conductivity of the slight Al-doped one (x=0.67, y=0.2) was the highest though that was the weighed composition. Its conductivity was almost P(O2)-independent, while a slight increase in conductivity with increasing P(O2) was observed in the high temperature region. The current-voltage characteristic of a fuel cell utilizing the novel electrolytes was also investigated employing platinum electrodes as both anode and cathode.