Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7738695 | Journal of Power Sources | 2014 | 12 Pages |
Abstract
Pure-phase La0.75Sr0.25Cr0.5Mn0.5O3âδ (LSCM) nanocrystallites have been successfully synthesized by the combustion method, employing glycine as fuel and complexing agent, and ammonium nitrate as combustion trigger. A detailed morphological and structural characterization is performed, by using of X-ray diffraction, N2 physisorption and electron microscopy. The LSCM material consists in interconnected nanocrystallites (â¼30 nm) forming a sponge-like structure with meso and macropores, being its specific surface area around 10 m2 gâ1. Crystalline structural analyses show that the LSCM nanopowder has trigonal/rhombohedral symmetry in the R-3c space group. By employing the spin coating technique and quick-stuck thermal treatments of the ink-electrolyte, electrodes with different crystallite size (95, 160 and 325 nm) are built onto both sides of the La0.8Sr0.2Ga0.8Mg0.2O3âδ-disk electrolyte. To test the influence of the electrode crystallite size on the electrocatalytic behavior of the symmetrical cells, electrochemical impedance spectroscopy measurements at 800 °C were performed. When the electrode crystallite size becomes smaller, the area specific resistance decreases from 3.6 to 1.31 Ω cm2 under 0.2O2-0.8Ar atmosphere, possibly due to the enlarging of the triple-phase boundary, while this value increases from 7.04 to 13.78 Ω cm2 under 0.17H2-0.03H2O-0.8Ar atmosphere, probably due to thermodynamic instability of the LSCM nanocrystallites.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Corina M. ChanquÃa, Alejandra Montenegro-Hernández, Horacio E. Troiani, Alberto Caneiro,