Characterization of SOFC Cathodes Prepared by Pulse Laser Deposition

We studied the electrochemical performance and microstructural characteristics of La1-ySryCoO3-delta (LSCO) cathodes prepared by pulse laser deposition (PLD). This technique allows the growth of nanostructured cathode layers with vertically-aligned nanopores (VANP). In some samples, a vertically aligned nanocomposite (VAN) LSCO/CGO layer was introduced between the cathode and the Ce0.9Gd0.1O1.95 (CGO) electrolyte. The structure and morphology of several film configurations were characterized by X-ray diffraction, transmission and scanning electron microscopy, and synchrotron X-ray reflectometry, while the electrochemical properties were evaluated by means of impedance spectroscopy. We found that cathode area specific resistances (ASR) for VANP LSCO samples are almost independent of film thickness and are within the lowest reported values. A significant decrease in the ASR values was observed while heating the sample, but after this first heating, the ASR values were reproducible, indicating that these nanostructures are stable in the used temperatures and oxygen partial pressure ranges.