resumo
The effects of the substitution of Co with Mn in the crystal structure, oxygen content, thermal stability and expansion and electrical properties of GdBaCo2-xMnxO5+delta (0 <= x <= 2) oxides are reported. Composites of GdBaCo2-xMnxO5+delta-Ce0.9Gd0.1O2-delta (70 : 30 wt%) are used as cathode materials and their electrochemical behaviour is presented. Layered-type ordering of Ba and Gd cations in the perovskite structure occurs in the whole system when the materials are prepared in argon but only for compositions in the range corresponding to x < 1.4 when the materials are prepared in air. The oxygen content increases with increasing the Mn content, causing thermal stability to improve and thermal expansion to decrease. However, lowering of the dc conductivity and an increase of electrode polarization resistances are observed by Mn substitution for Co. Cation ordering of the Gd and Ba atoms seems to affect the electrochemical properties of the materials.
palavras-chave
DOUBLE-PEROVSKITE; TRANSPORT-PROPERTIES; LAYERED PEROVSKITES; THERMAL-EXPANSION; PHASE-TRANSITION; CATHODE MATERIAL; SOFC; GDBACO2O5+X; MN; FE
categoria
Chemistry; Energy & Fuels; Materials Science
autores
Munoz-Gil, D; Urones-Garrote, E; Perez-Coll, D; Amador, U; Garcia-Martin, S
nossos autores
Daniel Muñoz Gil
Bolseiro de pós-Doutoramentoagradecimentos
This work has been supported by MINECO with Projects MAT2013-46452-C4-4-R, MAT2016-78362-C4-1-R, MAT2016-78362-C4-4-R, ENE2015-66183-R and CM with project MATERYENER3CM-S2013/MIT-2753. U. A. also thanks the Universidad San Pablo for financial support. S. Garcia-Martin thanks Prof. West for his unique teaching on solid state chemistry during her post-doc time at the University of Aberdeen.