Deposition of (La,Sr)CoO₃-δ and (La,Sr)₂CoO₄-δ Cathode Layers on Gadolinia-Doped Ceria by Electrospray Deposition

Abstract

La-, Sr-, and Co-based oxides have proven their performances in the cathode layers of intermediate temperature levels of solid oxide fuel cells (SOFC), and hence have been frequently studied. They are deposited on the electrolyte layer by chemical vapor deposition (CVD), screen printing, pulsed laser deposition (PLD), etc. The electrospray deposition (ESD) proved itself as an effective and facile method for cathode deposition. Cathode layers deposited on gadolinia-doped ceria (GDC) with the compositions of (La0.5Sr0.5)CoO3, (La0.8Sr0.2)CoO3, (La0.5Sr0.5)2CoO4, and (La0.8Sr0.2)2CoO4 are known to provide low resistance values which are critical in cell performance. In this study, ESD is used for the first time as the coating method of these compositions. Area-specific resistance (ASR) measurements made by electrochemical impedance spectroscopy (EIS) showed promising results. Particularly, the sample coated in (La0.5Sr0.5)CoO3 composition showed an ASR value of 0.11 Omega.cm2 at 700 degrees C. ESD showed the ability to control the cathode coating microstructure by controlling the spraying parameters.