Promising performances for a La0.6Sr0.4Co0.8Fe0.2O3-δ cathode with a dense interfacial layer at the electrode-electrolyte interface
Résumé
As for the commonly studied La0.6Sr0.4Co0.2Fe0.8O3-δ (6428), here, a very low area-specific resistance (ASR) was measured for La0.6Sr0.4Co0.8Fe0.2O3-δ (6482) cathode deposited on a Ce0.9Gd0.1O2-δ (GDC) electrolyte with addition of a thin (1 μm) dense LSCF film deposited by spin coating at the interface between the GDC electrolyte and a 40-μm-thick screen-printed electrode. The ASR ranged from 1 Ω.cm2 at 500 °C, 0.11 Ω.cm2 at 625 °C and value as low as 0.03 Ω.cm2 at 700 °C. Impedance spectra collected in between 500 and 700 °C were carefully studied. They could all be modelled with two R//CPE in series which are likely associated to the oxygen reduction reaction itself (dissociation/adsorption/ionization) at low frequency and to the oxide ion transfer at the electrode/electrolyte interface at high frequency.