92 y2o3 008 figure 58 illustration of oxygen ion

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Unformatted text preview: 0C 1000C 0.79 eV 2 i (S/cm) = 1.63 10 exp ZrO2 in a cubic fluorite structure and maximize oxygen vacancies, as pure YSZ in no kB T kB = 8.617 10 5 eV/K suitable ion conductor. High electrolyte temperature is required to ensure adequate oxygen ion conduc ity in the solid-state ceramic electrolyte, as oxygen ion mobility is nearly zero below critical light-off temperature in the electrolyte. As a result, conventional SOFCs will produce any significant current until being externally heated to the light-off temperatu Commonly used electrolyte conductivity is nearly zero until around 650 C [14], althou low-temperature SOFC operation at 500 C using doped ceria (CeO2 ) ceramic and ot electrolytes has shown feasibility [13]. The YSZ has a mixed (electrical and ionic) conductivity, but the electrical conductiv is nearly negligible for typical operating conditions in the SOFC. The ionic and electri conductivity of 8% mole fraction yttria YSZ, (ZrO2 )0.92 (Y2 O3 )0.08 , has been well stud [14]: i S cm = 1.63 102 exp -0.79 eV kB T 5 (5. Tuesday, Novembe...
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This document was uploaded on 11/20/2013.

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