Tailoring Electrocatalytic Properties of Solid Oxide Fuel Cell Composite Cathodes Based on (La0.8Sr0.2)(0.95)MnO3+delta and Doped Cerias Ce(1 x)Ln(x)O(2 delta) (Ln=Gd, La, Er, Pr, Tb and x=0.1 0.2)

Abstract

100 107 17 1 ; S ; M. Balaguer 2013 ; [EN] Composites made of different doped cerias and (La0.8Sr0.2)(0.95)MnO3+ were studied as potential solid oxide fuel cell cathodes. Tb, Pr, Gd and Er have been introduced as ceria dopants to enhance the electrocatalytic properties of (La0.8Sr0.2)(0.95)MnO3+ composites fabricated within. Different electrochemical behaviors were observed for the studied composites depending on lanthanide cation nature, i.e., whether they can exhibit different oxidation states or not. Specifically, (La0.8Sr0.2)(0.95)MnO3+/ceria composites with a mixed valence dopants (Tb and Pr) in the CeO2 structure are the best performing and present a limiting step at low frequencies; whereas those with ceria-doping elements withfixed oxidation state (Gd and Er) exhibit the limiting processes at higher frequencies. This fact is related to the higher magnitude of the TPB enlargement in the composite cathode achieved thanks to the promotion of mixed ionic-electronic conductivity in the Pr/Tb-doped ceria phase.The best cathode performance was obtained with (La0.8Sr0.2)(0.95)MnO3+_Ce0.8Pr0.2O2- cathodes with the lowest values for the polarization resistance in the 900-700 degrees C temperature range. Funding from Spanish Government (MINECO ENE2014-57651 grant) is kindly acknowledged. Navarrete Algaba, L.; Balaguer Ramírez, M.; Vert Belenguer, VB.; Serra Alfaro, JM. (2017). Tailoring Electrocatalytic Properties of Solid Oxide Fuel Cell Composite Cathodes Based on (La0.8Sr0.2)(0.95)MnO3+delta and Doped Cerias Ce(1 x)Ln(x)O(2 delta) (Ln=Gd, La, Er, Pr, Tb and x=0.1 0.2). Fuel Cells. 17(1):100-107. https://doi.org/10.1002/fuce.201600133 Minh, N. Q. (1993). Ceramic Fuel Cells. Journal of the American Ceramic Society, 76(3), 563-588. doi:10.1111/j.1151-2916.1993.tb03645.x Mizusaki, J. (2000). Electronic conductivity, Seebeck coefficient, defect and electronic structure of nonstoichiometric La1â xSrxMnO3. Solid State Ionics, 132(3-4), 167-180. doi:10.1016/s0167-2738(00)00662-7 Jiang, S. P. (2003). Issues on ...