Deposition of La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 ͑LSCF͒ oxide films on Gd-doped ceria ͑CGO͒ substrates by an electrostatic-assisted ultrasonic spray pyrolysis ͑EAUSP͒ method was demonstrated for the first time in this work. The electrostatic field employed for directing the aerosol stream toward the substrate was shown to be indispensable for film deposition. The X-ray diffraction result indicates that a single phase of cubic perovskite was obtained in the calcined films. Scanning electron microscopy examination reveals that the electric field strength had a profound effect on film porosity with weaker field, resulting in higher porosity. The results of impedance measurement on LSCF//CGO//LSCF cells indicate that the area specific resistance values of current LSCF films and their activation energies are comparable to that obtained by conventional sample preparation routes. In view of the simplicity, efficiency, and economy of film deposition, and the sound electrochemical characteristics of the obtained films manifested in current work, it is concluded that the EAUSP method is a promising method for preparation of SOFC electrode films.To obtain the desired high ionic and electronic conduction characteristics in the electrodes of solid oxide fuel cells ͑SOFCs͒, multiple doping with various elements in the matrix oxide is often necessary. However, the conventional solid-state reaction route involving ballmilling and repeated grinding and sintering is energyintensive and time-consuming, and the composition homogeneity in the resultant powder is often unsatisfactory. Moreover, subsequent steps such as slurry coating, tape casting, or screen printing and cofiring with the electrolyte further increase the overall complexity and cost for the manufacturing of SOFCs. In pursuit of a simple one-step solution, a variety of vapor processing techniques have been used to fabricate the electrode films of SOFCs, such as chemical vapor deposition, 1 physical vapor deposition, 2 and electrochemical vapor deposition ͑EVD͒. 3,4 These vapor processing methods are generally very expansive because they involved the use of sophisticated reactors and/or vacuum systems. Therefore, a cost-effective film deposition method that can be operated in open air is highly desirable.In this work, an aerosol spray pyrolysis system using an ultrasonic atomizer as the aerosol generator and an electrostatic field to constrain the aerosol flow was constructed ͑see Fig. 1͒. The feasibility for deposition of multicomponent oxide films using this electrostatic assisted ultrasonic spray pyrolysis ͑EAUSP͒ system was demonstrated by the deposition of La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 ͑LSCF͒ oxide, which is a promising material for intermediate-temperature SOFC cathodes. 5-17 Aerosol spray pyrolysis using an ultrasonic aerosol generator has been named chemical mist deposition ͑CMD͒ and is widely used in oxide film preparation. [18][19][20][21][22] In the CMD method, the aerosol generated from the precursor-containing solution is carried by a carrying gas and directl...

Deposition parameters were varied systematically to obtain NiO/Gd-doped CeO2 composite films using the electrostatic spray deposition method. The microstructure and morphology of the obtained films were investigated using a scanning electron microscope and an x-ray diffractometer. The degree of wetting of aerosol droplets on substrates decreased in the order of silicon wafer > stainless steel > glass. For deposition on silicon wafers, a continuous, flat layer was formed first due to excellent wetting of aerosol droplets on the substrate. Isolated particles were then nucleated and precipitated from the subsequent landing droplets and scattered on the bottom layer due to the very limited wetting of aerosol droplets on the flat oxide layer. Preferential landing of aerosol droplets on the isolated particles and subsequent precipitation and agglomeration of the fine particles finally resulted in a cauliflower morphology. Higher deposition temperature and lower flow rate of precursor solution resulted in drier droplets and hence diminished wetting and favoured particle precipitation, preferential landing of aerosol droplets and subsequent particle agglomeration. Increasing substrate roughness also favoured preferential landing of aerosol droplets and particle agglomeration. The composition of the deposited films was in fairly good agreement with that of the starting solution as revealed by the inductively coupled plasma mass spectrometer.

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Solid oxide fuel cells (SOFCs) based on the proton conducting BaZr0.1Ce0.7Y0.2O3–δ (BZCY) electrolyte were prepared and tested in 500–700 °C using humidified H2 as fuel (100 cm3 min–1 with 3% H2O) and dry O2 (50 cm3 min–1) as oxidant. Thin NiO‐BZCY anode functional layers (AFL) with 0, 5, 10 and 15 wt.% carbon pore former were inserted between the NiO‐BZCY anode and BZCY electrolyte to enhance the cell performance. The anode/AFL/BZCY half cells were prepared by tape casting and co‐sintering (1,300 °C/8 h), while the Sm0.5Sr0.5CoO3–δ (SSC) cathodes were prepared by thermal spray deposition. Well adhered planar SOFCs were obtained and the test results indicated that the SOFC with an AFL containing 10 wt.% pore former content showed the best performance: area specific resistance as low as 0.39 Ω cm2 and peak power density as high as 0.863 W cm–2 were obtained at 700 °C. High open circuit voltages ranging from 1.00 to 1.12 V in 700–500 °C also indicated negligible leakage of fuel gas through the electrolyte.

Two techniques of spray pyrolysis, namely, electrostatic and pneumatic spray deposition, were used to deposit samaria-doped ceria (SDC) electrolyte and lanthanum strontium cobalt ferrite (LSCF) cathode on cermet or metal supported anodes for solid oxide fuel cells (SOFCs) operated at reduced temperature. The deposition processes, the properties of the deposited films, and the electrochemical performances of the fabricated cells are reported in this paper. The deposited SDC electrolytes were dense and gas-tight, and had good adhesion to the underlying anodes. The deposited LSCF cathode had a preferred morphology to facilitate the transport of oxygen gas and effective contact with the electrolyte. Button cell testing indicated that the SOFCs with electrolyte or cathode deposited by spray pyrolysis had good electrochemical performance. This study demonstrated that spray pyrolysis is a cost-effective process for fabricating thin film SOFCs, especially metal supported SOFCs.