Characteristics of Lanthanum Silicates Electrolyte for Solid Oxide Fuel Cells

Abstract

La 9.33 (Si 5 V 1 )O 26 ceramics were fabricated by the mixed oxide method for solid oxide electrolytes. La 9.33 (Si 5 V 1 )O 26 specimens showed the hexagonal, space group P63 or P63/m, and the unit cell volume increased when the sintering temperature increased. The specimen sintered at 1,400℃ showed the X-ray patterns of the homogeneous apatite single phase without the second phase, such as La 2 SiO 5 and SiO 2 . The specimen sintered at 1,400℃ showed the maximum sintered density of 4.93 g/cm 3 . When the sintering temperature increased, the electrical conductivities increased, the activation energy decreased and the values were 7.83×10 -4 S/cm, 1.61 eV at 600℃, respectively.

The use of silicon in the membrane electrode assembly of fuel cells

“…Doping LSO and/or synthesis of apatite powders via wet chemical route can be effective to reduce sintering temperature. For example, doping with transition metals such as Zn [66] and V [72] can improve the sintering of LSO. Doping with alkaline elements, such as Ba, also improves LSO sintering: [61] The bulk density of La 9.5 Ba 0.5 Si 5.5 Al 0.5 O 26.5 was remarkably higher than that of La 10 Si 5 AlO 26.5 sintered at the identical temperatures.…”