Oxygen‐ion conduction in scandia‐stabilized zirconia‐ceria solid electrolyte ( x Sc 2 O 3 –1CeO 2 –(99− x )ZrO 2 , 5 ≤ x ≤ 11)

Solid oxide fuel cells ( SOFC s) operating at intermediate temperature (500°C‐700°C) provide advantages of better durability, lower cost, and wider target application market. In this work, we have studied Sc 2 O 3 (5‐11 mol%) stabilized ZrO 2 –CeO 2 as a potential solid electrolyte for application in IT ‐ SOFC s. Lower Sc 2 O 3 doping range than the traditional 11 mol% Sc 2 O 3 ‐stabilized ZrO 2 is an interesting research topic as it could potentially lead to an electrolyte with reduced oxygen vacancy ordering, lower cost, and higher mechanical strength. XRD and Raman spectroscopy was used to study the phase equilibrium in ZrO 2 –CeO 2 –Sc 2 O 3 system and impedance spectroscopy was done to estimate the grain, grain boundary, and total ionic conductivities. Maximum for the grain and grain‐boundary conductivities as well as the tetragonal‐cubic phase boundary was found at 8‐9 Sc 2 O 3 mol% in ZrO 2 ‐1 mol% CeO 2 system. It is suggested that the addition of 1 mol% CeO 2 in the ZrO 2 host lattice has improved the phase stability of high‐conductivity cubic and tetragonal phases at the expense of low‐conductivity t′‐ and β‐phases.