
403Fuel Cell Components and Design
9.5.2.3 Scandia-Stabilized Zirconia (ScSZ)
Scandia (Sc
2
O
3
) doped zirconia (ZrO
2
) is also of considerable interest as an SOFC
electrolyte, particularly in the intermediate temperature range. A higher con-
ductivity is observed for scandia-stabilized zirconia (ScSZ) electrolyte with
8%–10% scandia concentration as compared to YSZ. At an operating tem-
perature of 1000°C, 9% ScSZ has a conductivity of 0.32 S cm
–1
as compared to
0.164Scm
–1
for 8% YSZ. The enhancement is believed to be caused primarily by
the smaller difference in the sizes of Zr
4+
and Sc
3+
ions as compared to the differ-
ence between Zr
4+
and ...