Zirconia based oxide ion conductors for solid oxide fuel cells

Abstract

Abstract. The electrical conductivity in the ZrO2-Ln203 and ZrO2-MO2-Ln203(M = Hf, Ce, Ln = lanthanides) systems has been examined.The highest conductivity of 0.3 S/cm at 1000 ~ was found in the ZrO2-Sc203 system. The addition of MO2 into the ZrO2-Ln203(Ln = Sc, Y, Yb) systems showed the conductivity decreasing. The conduction mechanism in the zirconia based oxide ion conductors was discussed in view of the dopant ionic radius. The aging effect of the conductivity in the ZrO2-Ln203 systems has been measured in a temperature rang 800-1000 ~ ZrO2 with a high content of Ln203 showed no significant conductivity degradation.

Characterization of ZrO co-doped with ScO and CeO electrolyte for the application of intermediate temperature SOFCs

“…According to many reports on the conductivity of various zirconia-based electrolytes, ZrO 2 doped with Sc 2 O 3 is known to have the highest ionic conductivity [26][27][28][29][30][31][32][33][34][35][36]. However, there were some problems with materials that remain to be solved in this Sc 2 O 3 doped ZrO 2 system (SZ), which were correlated with the phase transition of the high conductive phase during cooling or aging at high temperatures.…”

“…Many researchers have proposed various additional dopants like CeO 2 , Sm 2 O 3 , Yb 2 O 3 and Al 2 O 3 to reduce or prohibit such an undesirable phase transition as from a high conductive cubic phase to a lower conductive rhombohedral h or tetragonal phase [26,34,36,37]. Especially the Japanese's researchers have been focusing on the improvement of SZ stability via various doping study and approved the usefulness of SZ electrolyte for intermediateor low-temperature SOFC application [34,37].…”

Single crystal growth and oxide ion conductivity of apatite-type rare-earth silicates

“…Conventional oxide ionic conductors have a structure of fluorite (e.g. stabilized zirconia [1]) or perovskite (e.g. La 0.8 Sr 0.2 Ga 0.8 Mg 0.115 Co 0.085 O 3 [2]).…”

Synthesis and characterization of nanocrystalline dysprosia stabilized zirconia based electrolyte for intermediate-temperature solid oxide fuel cell

“…dia stabilized zirconia (ScSZ) is considered a promising candidate [9,10]. Recent investigations on the use of dysprosia (Dy 2 O 3 ) as a dopant have indicated a possibility of decreasing the working temperature of the SOFC [11]. Moreover, DySZ possesses a lower (∼40%) thermal conductivity [12] and hence may prove better suited for operation and thermal management in SOFC than YSZ.…”