A recent Research line of our group corresponds to materials for energy-conversion devices, in particular electrodes for solid-oxide fuel cells (SOFC), since many of the oxides that traditionally were studied from the magnetic or electronic point of view (superconducting, colossal magneto-resistant oxides…) find applications, with subtle modifications, as electrodes in these electrochemical devices.
In particular, the wide family of transition-metal oxides with perovskite structure presents a rich panoply of polyvalent materials that fulfill most of the features required for mixed ionic-electronic conductor (MIEC) oxides. In the last years we have developed innovative cathode materials that have allowed us to achieve impressive performances in electrolyte-supported fuel cells.
Some of the classic transition metal oxides with perovskite structure such as SrFeO3-d, LaNiO3 or SrCoO3-d, have been well-known since the fifties for their elevated electronic conductivity and oxygen diffusion properties; the introduction of selected doping elements into the structure has allowed us, during our research work in the last few years, to stabilize their crystal structures at the working temperature of the SOFC’s while preserving the required transport properties.
These investigations have resulted in competitive cathode materials that, once integrated into single fuel cells, surpass the power-density target for intermediate-temperature SOFCs using some selected double perovskites as anodes.
Among the different materials designed, prepared and tested in single SOFC cells, we can mention the examples of SrCo1-xSbxO3, SrCo1-xMoxO3 and Sr0.7Y0.3CoO3 as cathodes and SrMo1-xFexO3 or SrMo1-xCrx as anodes; all of them are MIEC electrodes that allow decreasing the working T of operation of the SOFCs.
SrCo1-xSbxO3-delta perovskite oxides as cathode materials in solid oxide fuel cells, Aguadero, ,A, Perez-Coll, D, de la Calle, C, Alonso, JA, Escudero, MJ, Daza, L, JOURNAL OF POWER SOURCES 192, 132-137 (2009).
SrCo0.95Sb0.05O3-delta as Cathode Material for High Power Density Solid Oxide Fuel Cells Aguadero, A, Alonso, JA, Perez-Coll, D, de la Calle, C, Fernandez-Diaz, MT, Goodenough, JB, CHEMISTRY OF MATERIALS 22, 789-798 (2010)
Defective Ni Perovskites as Cathode Materials in Intermediate-Temperature Solid-Oxide Fuel Cells: A Structure-Properties Correlation, Hou, SE, Alonso, JA, Rajasekhara, S, Martinez-Lope, MJ, Fernandez-Diaz, MT, Goodenough, JB, CHEMISTRY OF MATERIALS 22, 1071-1079 (2010)
Oxygen-Deficient Perovskite Sr0.7Y0.3CoO2.65-delta as a Cathode for Intermediate-Temperature Solid Oxide Fuel Cells, Li, Yan; Kim, Young N.; Cheng, Jinguang; Alonso, Jose A.; Hu, Zhiwei; Chin, Yi-Ying; Takami, Tsuyoshi; Fernandez-Diaz, Maria T.; Lin, Hong-Ji; Chen, Chien-Te; Tjeng, Liu H.; Manthiram, Arumugam; Goodenough, John B. CHEMISTRY OF MATERIALS 23, 5037-5044 (2011)
Evolution of cobalt spin states and magnetic coupling along the SrCo(1-x)Sb(x)O(3-delta) system: correlation with the crystal structure, Aguadero, A.; Retuerto, M.; Jimenez-Villacorta, F.; Fernandez-Diaz, M. T.; Alonso, J. A., PHYSICAL CHEMISTRY CHEMICAL PHYSICS 13, 12835-12843 (2011)
Oxygen-Deficient R(2)MoO(6-delta) (R = Tb, Dy, Y, Ho, Er, Tm, Yb) with Fluorite Structure as Potential Anodes in Solid Oxide Fuel Cells Aguadero, A.; Martinez-Lope, M. J.; Pomjakushin, V.; Alonso, J. A. EUROPEAN JOURNAL OF INORGANIC CHEMISTRY 21, 3226-3231 (2011)
Structure, thermal stability and electrical properties of Ca(V0.5Mo0.5)O-3 as solid oxide fuel cell anode, Aguadero, A, de la Calle, C, Alonso, JA, Perez-Coll, D, Escudero, MJ, Daza, L, JOURNAL OF POWER SOURCES 192, 78- 83 (2009)