Characterization of Cathode/Electrolyte Interphases for IT-SOFCs

BAQUÉ, LAURA; PADMASREE, K.; FUENTES, A.F.; SERQUIS, ADRIANA C.; SOLDATI, ANALIA L.

Cancun

Congreso; XIV International Congress of the Mexican Hydrogen Society; 2014

Mexican Hydrogen Society

Solid oxide fuel cells (SOFCs) represent an efficient and environmental friendly technology to obtain electrical power and heat.  In recent years, a considerable research effort has been done in order to decrease their operation temperature from 800-1000ºC to the 500-800ºC range.  However, the main drawback of lowering SOFC operating temperature is the reduction of cell performance and, hence each individual component and their interfaces must be enhanced. In this work, we studied symmetrical cells composed by high performance nanostructured La0.4Sr0.6Co0.8Fe0.2O3 (LSCFO) cathodes deposited by spin coating on Ce0.8Y0.2O2 (CYO) substrates.  CYO electrolytes were synthesized by mechanical milling using two different milling times. Longer milling time produces electrolytes with smaller grain sizes, narrow size distribution and higher density. Bulk conductivity values are similar for both electrolytes, while grain boundary conductivity was slightly higher for the electrolyte prepared with shorter milling time. All this indicates that longer milling times do not improve electrolyte conductivity but, instead, it can have a detrimental effect on it.