Methods The electrolyte and cathode layers of the thin film SOFCs were fabricated on 10-μm-thick nickel foil

(to act as an anode). The thin film solid oxide fuel cell fabrication process flow is illustrated in Figure 1, wherein the nickel AG-14699 foils were treated for a short time in a mixture of acetic, nitric, sulphuric, and phosphoric acids to remove any rolling marks left on the foil surface followed by a degreasing process (acetone, methanol, and DI water). The clean nickel foils were annealed at 650°C for 2 h in an argon atmosphere in order to generate atomic ordering with the lattice (100) direction normal to the foil surface. Layers of yttria-stabilized zirconia (YSZ) electrolyte (approximately 1.5 μm thick) and La0.5Sr0.5CoO3 – δ (LSCO) cathode (approximately 2 μm thick)

were deposited on the nickel foils using pulsed laser deposition (PLD; 248-nm KrF laser) in an initially 96% argon/4% hydrogen atmosphere (to avoid nickel oxidization) and then in an oxygen atmosphere (to yield good oxide stoichiometry) at substrate temperatures of 25°C to 650°C. Hexagonal pores (about 50-μm diameter with 50-μm spacing) were etched in the nickel anode by photolithographic patterning followed by either wet etching (using 0.25 M FeCl3) or electrochemical etching (using 6 M H2SO4) at room temperature (see Figure 1). Figure 1 Schematic diagram for LSCO/YSZ/Ni thin SOFC(s) fabrication process flow. The crystalline structures Decitabine in vivo of the successive layers of the fabricated fuel selleck chemicals llc cells were characterized

by X-ray diffraction (XRD) measurements which were carried out using a Siemens D-5000 spectrometer (Erlangen, Germany). The XRD scans were done in the standard θ-2θ configuration, using the Cu Kα radiation of wavelength 1.54 Å at scan steps of 0.05°. SEM analysis was carried out using a JEOL (JSM 5410, Akishima, Tokyo, Japan) scanning electron microscope. A computerized testing setup was used to test the fuel cells fuel-air performance (I-V and power output characteristics) as a function of operating temperature. Results and discussion The XRD scans of the different layers of the fabricated samples are shown in Figure 2. The XRD scan of the approximately 1.5-μm-thick YSZ electrolyte film deposited on treated nickel foil by PLD at 650°C (Figure 2a) shows two major peaks: Ni (200) at θ = 51.85° and YSZ (200) at θ = 34.8°. However, the appearance of low-intensity peak at θ = 44.5° indicates a small percentage of the (111) crystalline orientation in Ni. The XRD scan of the 2-μm-thick cathode (LSCO) film deposited on the YSZ/Ni sample by PLD first at 650°C and then at room temperature (Figure 2b) shows an LSCO (200) small broad peak at θ = 43°. The LSCO (100) orientation is more favorable because of its high conductivity compared to other types of crystallographic orientations [9].