Page 199 - High Temperature Solid Oxide Fuel Cells Fundamentals, Design and Applications

176 High Temperature Solid Oxide Fuel Cells: Fundamentals, Design and Applications

-14 -12 -10 -8 -6 -4 -2 0
LOG OXYGEN PAFfllAL PRESSURE
Figure 7.2 Oxygen vacancy concentration and electrical conductivity as a function of oxygen partial
pressureanddopant contentfor LaCr,-,MgX03at 120OoC/3J.

0.4 IJ I
-20 -18 -16 -14 -12 -IO -a -6 -4 -2 o
LOG (Po /ah)
2
Figure 7.3 Electrical conductivity os. oxygen partial pressure for Yo &ao 2Cr03 at various
temperatures 171.

how the electrical conductivity changes with oxygen activity for both of these
chromites [2, 61. What makes the chromites useful as interconnects is that at
1000°C and bar oxygen pressure, they remain single phase and do not
dissociate. There are no other oxides which have these levels of electrical