º«¹úεɽ¹úÁ¢¿Æ¼¼Ñ§Ôº Ë«¸ÆîÑ¿óÐÍPrBaCo2 xFexO5£¨x = 0ʱ£¬0.5£¬1£©Òõ¼«²ÄÁϵĵ绯ѧºÍÈÈÁ¦Ñ§ÌØÐԵĵÄÑо¿ ¡¶Journal of Power Sources ¡·
The effect of Fe substitution for Co on the thermodynamic and electrical properties of the double perovskites, PrBaCo2−xFexO5+ı (PBCF, x = 0, 0.5, 1), are investigated as cathode materials for intermediatetemperature solid oxide fuel cells (IT-SOFCs). At a given temperature, the electrical conductivity decreases with increasing Fe content, x, in the PBCF¨CYSZ composites in air. PBCF¨CYSZ (x = 1) composite appear to be more stable than PBCF¨CYSZ (x = 0) composite down to lower oxygen partial pressure, p(O2), at the same temperature. The higher oxidation enthalpies of the x = 1 composite can also explain the superior stability at roughly the same p(O2). The high entropy change for the x = 1 composite can indicate the high probability in the formation of interstitial oxygen at approximately the same p(O2). Impedance spectra of symmetrical cells (PBCF¨CYSZ/YSZ/PBCF¨CYSZ) show lower cathode polarization losses with increasing amounts of Fe. The maximum power densities of x = 0 composite and x = 0.5 composite are 0.68 and
0.72 W cm−2, respectively, at 973 K. The maximum power density of the x = 1 composite is, however, about 20% higher than that of the other composites. Considering redox stability and electrochemical performance, higher Fe content of PrBaCo2−xFexO5+ı (x = 1) is more suitable as a cathode material than x = 0
composite in IT-SOFC application.
Keywords:
Solid oxide fuel cells £¬Cathode£¬Double perovskite£¬Oxygen nonstoichiometry
£¬Thermodynamic property£¬Electrochemical performance![]()
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