Ceria (CeO2) doped with gadolinium ions (Gd 3+ ) has been found to be promising in terms of its ionic conductivity for use as a SOFC electrolyte. Ce0.9Gd0.1O1.95 (CGO10) composition has been found to have better ionic conduction than YSZ . The TEC of CGO10 is 13.5 × 10 -6 K -1 , thus making it compatible with other cell components . However, in CGO electrolytes under anodic conditions at operating temperatures, Ce 4+ ions are reduced to Ce 3+ ions and this is responsible for n-type electronic conduction, which short circuits the cell, thereby reducing the performance .