Performance of (La,Sr)(Co,Fe)O 3− x double-layer cathode films for intermediate temperature solid oxide fuel cell

Abstract

In this study the performance evaluation of (La,Sr)(Co,Fe)O 3− x (LSCF) double-layer films characterized by impedance spectroscopy between 403 and 603 °C to be used for intermediate temperature solid oxide fuel cells (IT-SOFCs) is presented. Two LSCF layers with different microstructures were sequentially deposited onto Ce 0.9Gd 0.1O 1.95 (CGO) substrates in a symmetrical fashion. A first layer of La 0.6Sr 0.4Co 0.2Fe 0.8O 3− x with a thickness of 7 μm and a nano-scaled particle size was deposited by electrostatic spray deposition (ESD) technique. Different deposition conditions were used in preparing the ESD films to evaluate the influence of film morphology on the electrochemical performance. After annealing, a current collector layer of La 0.58Sr 0.4Co 0.2Fe 0.8O 3− x with ∼45 μm in thickness and a larger particle size was deposited by screen printing. Area specific resistances ( ASRs) were determined from impedance spectroscopy measurements performed in air between 403 and 603 °C, at 25 °C steps. A dependence of electrochemical performance on the morphology of the LSCF layer deposited by ESD was observed. The lowest ASR, measured during 130 h of isothermal dwelling at 603 °C, averaged 0.13 Ω cm 2 with negligible variation and is the lowest reported value for this composition, to the best of our knowledge. Reported results assure an excellent suitability of this type of assembly for IT-SOFCs.