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A hybrid power system consisting of an intermediate temperature solid oxide fuel cell (SOFC) and a lithium-ion battery is conceptually designed for water taxi applications. The sizing method of such a hybrid system is developed based on the resistance, acceleration performance, cruising cycle, and the speeds of a water taxi under the conditions of daily operation time and charge neutrality over a 24 h period. A techno-economic analysis (TEA) is performed for the proposed hybrid system and compared with other two power sources, a typical internal combustion engine (ICE), and a battery-only system. A feasibility study based on the weight and the volume of the hybrid system is conducted. The potential reduction of greenhouse gases (GHG) emissions is calculated and compared with the GHG emissions from water taxies powered by an ICE and a battery-only, respectively.

The vanadium redox flow battery (VRFB) is one of the most promising energy storage technologies for large scale commercialization. The vanadium electrolyte is the main component, determining the VRFB’s energy density and capacity. The quality of the vanadium electrolyte is key to VRFB’s operation, as presence of soluble impurities will affect VRFB’s performance and durability. Understanding the impact of these impurities may ultimately lead to a specification for the impurity levels a VRFB can tolerate without compromising its performance and durability. Fe is an impurity element typically found in the vanadium ores, which is also present in the commercially available vanadium electrolytes. It was reported that Fe in positive electrolyte in a narrow concentration range (< 0.0286 M or 0.12 wt. %) could slightly affected the VRFB performance [1]. At high concentration (1.0 - 1.4 M Fe), Fe was reported to stabilize the positive electrolyte at high temperature (50oC) [2]. However, systematic studies on the effect of Fe on vanadium redox reactions, over a wider range of concentrations, are needed in order to achieve a good understanding of how it affects the VRFB performance. This work reports on the effect of Fe on vanadium redox reactions, with concentrations ranging from 0.05 wt. % or 0.012 M to 2 wt. % or 0.48 M, investigated by cyclic voltammetry and VRFB single cell cycling. In the present study, CV response of vanadium electrolyte on glassy carbon, Pt disk and graphite electrode was compared. On glassy carbon and Pt disk electrodes, vanadium redox reaction has shown irreversible or partially reversible CV response, while on graphite rod electrode, reversible redox reaction response was observed. Thus, a graphite rod was selected as working electrode for the subsequent investigations. The cyclic voltammogram on graphite rod electrode is dependent on electrode pre-treatment. Redox peak current, and peak separation are different on freshly polished graphite electrode compared to an electrode that has been used for a certain period of time (e.g. half hour). The difference is dependent on Fe concentration. In 0.05 wt. % (or 0.012 M) Fe electrolyte, electrode passivation was observed (Fig. 1), where the freshly polished electrode shows higher redox peak current than the one that has been used for CV for a certain time. However, in electrolytes with higher Fe content (e.g. 0.5 wt. % or 0.12 M), the freshly polished electrode presents lower redox peak current, indicating that electrode activation can occur during CV testing (Fig 2). VRFB performance was further evaluated, and it was found that the effect of Fe on VRFB capacity, capacity change profile with cycling, and efficiency is dependent on Fe concentration. Low Fe concentration affected more on the efficiency, while higher Fe concentration shows significant effect on capacity change during cycling. AC impedance and vanadium crossover were used to diagnosis the VRFB performance and degradation, and it was found that Fe concentration affects VRFB degradation and water transfer. The tolerance level of Fe in vanadium electrolyte can be deduced from this study, which may provide guidance on the design of low purity vanadium electrolyte. References: M. Ding, T. Liu, Y. Zhang, Z. Cai, Y. Yang, Y. Yuan, Effect of Fe(III) on the positive electrolyte for vanadium redox flow battery. R. Soc. Open Sci. 6 (2019) 181309. Z. Li, Y. Lin, L. Wan, B. Wang, Stable positive electrolyte containing high-concentration Fe2(SO4)3 for vanadium flow battery at 50 oC, Electrochim. Acta 309 (2019) 148 – 156 Figure captions: Fig 1 Cyclic voltammogram of graphite rod electrode (Red curve: electrode surface was polished before the CV measurement, Blue curve: electrode surface was polished then measure CV at a variety of scan rates, no polish was performed before each scan rate) in 1.6 M VOSO4 in 2 M H2SO4 containing 0.05 wt. % Fe (0.012 M). Scan rate: 10 mV/s Fig 2 Cyclic voltammogram of graphite rod electrode (Red curve: electrode surface was polished before the CV measurement, Blue curve: electrode surface was polished then measure CV at a variety of scan rates, no polish was performed before each scan rate) in 1.6 M VOSO4 in 2 M H2SO4 containing 0.5 wt. % Fe (0.12 M). Scan rate: 10 mV/s. Figure 1

The Vanadium Redox Flow Battery (VRFB) is a promising energy storage technology for large scale stationary applications that require a long cycle life of over 10 years. The specific feature of VRFB is the slower kinetics of redox reactions (V2+/V3+) on the negative electrode (NE) as compared to the kinetics of the redox reaction (VO2 + /VO2+) on the positive electrode (PE) and poor kinetic reversibility.. The commonly used electrodes for VRFBs are graphite felt electrodes (GFE). One of the main challenges facing these GFEs is their activation that enhances a rate of redox reactions due to the increase of GFE wettability and surface area. Another challenge is capability to maintain GFE activation over cycling. In this work, we report on thermal and thermo-chemical activation of GFEs which leads to the formation of functional groups (carboxyl C=O, phenolic C-O, and adsorbed O or H2O for the enhancement of the electrode wettability and active surface area. The physicochemical characterization of the activated GFEs was performed using X-ray photoelectron spectroscopy (XPS) and contact angle measurements. The electrochemical study was conducted by cyclic voltammetry (CV) measurements in 0.2M VOSO4/2M H2SO4 at 1 mV/s and cycling tests (50 cycles, three tests for every GFE) in a commercial 9cm2 VRFB ( Standard Energy Corp.) using a charge/discharge current density of 80 mA/cm2 at 20oC and a commercial vanadium electrolyte 1.6M [V]/2M H2SO4. The increase of temperature of GFE heat treatment of GFEs from 400 to 500oC resulted in the growth of the energy efficiency (EE) of VRFBs with such electrodes from 81.3 to 87.2%, respectively, due to the increase of adsorbed oxygen or water from 1.6 to 8.72% and C-O (C-OH) groups from 0.49 to 2.09%, respectively and wettability (contact angle (CA) decreases from 78.7 to 65.1o). Analysis of CVs of the redox reaction VO2 + /VO2+ shows the decrease of the peak of potential separation ΔEp (Epa-Epc) from 0.357 to 0.345 V and the peak of current ratio (Jpa/Jpc) from 1.406 to 1.26, indicating lower polarization due to the increase of the electrode surface area, acceleration and reversibility of these redox reaction, respectively (Table 1). The proposed additional treatment of the heat treated GFE at 400oC (GFE400) in strong oxidants H2O2, H2SO4 and HNO3 for the decomposition of C=O and the enhancement of the content C-O groups and GFE wettability didnt result in the performance improvement (VRFB with GFE400+10%H2O2 - energy efficiency of 78%). The thermal treatment of GFE at 500oC demonstrated improvement of VRFB cell performance, namely growth of energy efficiency to 87.2% and VE to 90.1%, % due to the increase of wettability and active surface area of GFEs. Figure 1

Solid Oxide Fuel Cell is an attractive, efficient, alternative source of power generation. However several challenges remained for this technology to be viable. These challenges include high power density, degradation rate, and cost. One way to decrease the SOFC cost is to use stainless steel interconnector. To be able to use a stainless steel interconnector one of the challenges is to find a way to produce an electrolyte, which does not need sintering at high temperature. This work presents the results of the process applied to gadolinia-doped ceria thin films deposited in cycles by spray pyrolysis. The aim of this work was to obtain thin, dense, and continuous CGO coatings, which has electrochemical performance suitable to be used as electrolyte for SOFC. The results obtained show that the air flow rate influenced the droplets size and hence the film quality. X-ray diffraction analysis showed that the films were crystalline after the deposition. Electrochemical tests showed maximum power density of 510 mW cm-2 at 650 °C with a thickness average of 3.30 μm when the film was deposited in 12 cycles showing that the film has a potential to be used as an electrolyte for ITSOFC on metal support. © 2014 Elsevier B.V. All rights reserved.

This work presents the results of a process of optimization applied to gadolinia-doped ceria (Ce0.8Gd0.2O1.9-x, or CGO) thin films, deposited by spray pyrolysis (SP). Spray pyrolysis is a high thermal deposition method that combines material deposition and heat treatment. This combination is advantageous since the post-deposition heat treatment step is not necessary. However, stresses are solidified in the coating during the deposition, which may lead to the initiation of a crack in the coating. The aim of this work was to achieve thin, dense, and continuous CGO coatings, which may be used as gas separation membranes and as a solid state electrochemical interfaces. Dense, flat, low-defect substrates such as silica slides, silicon mono crystal wafers, and porous substrates were used as substrates in this work. Cerium ammonium nitrate and gadolinium acetylacetonate were dissolved in ethanol and butyl carbitol to form a precursor solution that was sprayed on the heated substrates. Process parameters such as solvent composition, deposition rate and different heating regimes were analyzed. The microstructure was analyzed by secondary electron microscopy (SEM) and was found that thin, dense, and defect-free films could be produced on dense and porous substrates. The results obtained show that it is possible to obtain a CGO dense film deposited by spray pyrolysis. X-ray diffraction (XRD) analysis showed that the films were crystalline after the deposition without requiring post-deposition heat treatment. The crystallite size does not vary significantly as a function of the annealing temperature. © 2012 Elsevier Ltd.

The development of solid oxide fuel cell with thin film concepts for an electrode supported design based on the yttria-stabilized zirconia has demonstrated favourable results due to its high chemistry stability in oxidization and environment reduction. The spray pyrolysis process was investigated in order to obtain dense thin films of YSZ on different substrates. The precursor solution was obtained by zirconium and yttrium salt dissolutions in a mixture of water and glycerine in several ratios to study the solvent influence. The substrate was initially heated at 600 °C and during the deposition it ranged from 260-350°C, finishing at a fast increase in temperature of 600°C. The heat treatment was carried out in four different temperatures: 700 °C, 750 °C, 800 °C, and 900 °. The precursors were characterized by thermal analysis. The microstructures of the films were studied using scanning electron microscopy and X-ray diffraction. The results obtained showed that the films obtained were crystalline before the heat treatment process and have shown ionic conductivity above 800°C., 8th International Latin-American Conference on Powder Technology, November 6-9, 2011, Florianópolis, Brazi

The present study examines the physical and electrochemical properties of platinum particles generated by a combustion method for use in oxygen reduction on the cathode side of a proton exchange fuel cell (PEMFC). This method employs a one-step, open-atmosphere, and dry deposition technique called reactive spray deposition technology (RSDT). The objective of this study is to characterize the intrinsic activity of the platinum produced for incorporation into low-loading cathode electrodes in high performing membrane electrode assemblies (MEA). The process allows for independent real-time control of the carbon, platinum, and ionomer ratios in the final electrode. In this research work we examine the oxygen reduction reaction via a rotating disk three electrode set-up to understand the intrinsic activity of the as-sprayed platinum as well as platinum condensed onto a carbon support. The mass and specific activities were measured in a 0.1 M perchloric acid electrolyte under different deposition conditions and loading was verified by atomic emission spectroscopy inductively coupled plasma (AES-ICP). Microscopy results indicate that the platinum particle sizes are 5 nm (σ = 2.8 nm) in diameter while TEM and XRD show that the platinum generated by the process is pure and crystalline without bulk oxides or precursor material present. The initial rotating disk electrode result shows that the RSDT technique is capable of producing catalysts with an oxygen reduction mass activity at 0.9 V of 200 mA/mgPt rotating at 1600 rpm and 30 °C. The electrochemically active surface area approaches 120 m2/g for the platinum, carbon, and ionomer samples and the unsupported sample with only platinum has an active area of 92 m2/g. The rather larger surface area of the unsupported sample exists when the platinum is deposited as a highly porous nanostructured layer that allows for high penetration of reactant.

The economic and technical breakthroughs in solid oxide fuel cell (SOFC) for commercial success still depend on high-quality manufacture, reliability, efficiency, and must have an acceptable cost when compared to competing technologies. The application of flame-based technologies as a one-step deposition technique for SOFC component manufacture has potential to reduce both cost and production time. In this article, cells produced by flame processes have been reviewed with emphases placed on the Reactive Spray Deposition Technology technique. Various experimental methods and examples for the synthesis of porous electrodes and dense electrolytes are reviewed. The studies focus on determining the range of the flame conditions under which each of the individual cell components for low temperature SOFC applications ∼600 °C could be successfully deposited. © 2011 ASM International.

National Research Council Canada's Institute for Fuel Cell Innovation, NRC-IFCI, has been developing the Reactive Spray Deposition Technology (RSDT) process to optimize composite electrode layer formation and develop novel electrocatalysts and catalyst layers. The RSDT process provides the means necessary to develop the next generation of thin, low platinum or alloy catalyst layers for PEM MEA's. In order to best manage water distribution, mass transport and conductivity, the structure should be a gradient with controlled porosity and controlled distribution of both platinum and ionomer across the catalyst layer. The RSDT process allows good control of the platinum particle size as they are created directly from metal vapors, which prevents agglomeration in the catalyst layer. Additionally, it has the flexibility to build a gradient layer structure across a very thin film catalyst layer (

Metal-supported solid oxide fuel cells (SOFCs) offer many advantages, including increased robustness, improved thermal shock resistance, and decreased cost. However, fabricating metal-supported SOFCs using conventional techniques is both very difficult and very costly. In this study, two processes of spray pyrolysis deposition, pneumatic spray deposition and electrostatic spray deposition, were used to deposit samaria-doped ceria (SDC) electrolytes on different substrates and NiO-SDC anodes on porous stainless steel substrates. A cathode layer was subsequently applied on the electrolyte by stencil printing for electrochemical testing. The test results indicated that the electrolyte had reasonable cell performance, but the topography of the anode needed optimization. It was also discovered that the porous ferritic stainless steel 430 substrate used in this study did not have sufficient oxidation resistance as the substrate of a metal-supported SOFC.

International audience; The influence of electrostatic spray deposition (ESD) process parameters such as the substrate temperature, the precursor solution flow rate and the nozzle-to-substrate distance on the morphology of YSZ thin coatings was studied. Each parameter was studied separately and the correlation between them was found in order to optimise the experimental conditions where dense, continuous zirconia coatings can be successfully deposited.

International audience; The present study is focused on the preparation of zirconia-based coatings obtained by Electrostatic Spray Deposition (ESD). Microstructural properties of ESD coatings were optimised versus the composition of the precursor solution and the substrate nature. This chemical approach includes the influence of zirconia precursors, yttrium chloride, solvent mixtures, zirconia precursor concentration, additives and substrate nature in order to optimally tune the microstructure of the coating. A smooth, dense and homogeneous thin layer was successfully deposited.

International audience; The deposition of a composite electrode, which consisted of a mixture of a solid electrolyte (YSZ) and an electrocatalytic material (LSM), on an YSZ substrate was studied using the electrostatic spray deposition (ESD) technique. Films with various morphologies were obtained. The surface morphology was strongly influenced by the deposition temperature, precursor solution flow rate, and nozzle to substrate distance as a function of the nature of precursor solution. Processes involved in the porous film formation were discussed. Powder X-ray diffraction analysis showed that only the LSM hexagonal phase and the cubic YSZ phase were formed in the LSM/YSZ composite cathode after thermal treatment at 800 °C.

In this paper we report the use of both ultrasonic spray pyrolysis and microwave-assisted polyol reduction methods to synthesize Nb-doped TiO2/carbon (25 wt% Nb0.07Ti0.93O2/75 wt% carbon) composite supports and Pt0.62Pd0.38 alloy catalysts, respectively. The physicochemical properties of the synthesized supports and their Pt0.62Pd0.38 supported catalysts are evaluated using several methods including XRD, TEM, BET surface area analysis, TGA, as well as ICP-MS elemental analysis. The electronic conductivities and thermal/chemical stabilities of the supports are also evaluated with respect to their possible use as catalyst supports. Electrochemical measurements for oxygen reduction activity of the Pt0.62Pd0.38 alloy catalysts supported on oxide/carbon composites are also carried out in order to check their suitability for possible PEM fuel cell applications. The results show that 20wt%Pt0.62Pd0.38/25 wt%(Nb0.07Ti0.93O2)-75 wt%C catalysts exhibit enhanced mass activities compared to those of commercially available 48wt% Pt/C and home-made 20wt% Pt62Pd38/C catalysts.

The use of a liquid feedstock carrier in suspension plasma spray (SPS) permits injection of fine powders, providing the possibility of producing sprayed coatings that are both thin and dense and have fine microstructures. These characteristics make SPS an attractive process for depositing highly efficient electrodes and electrolytes for solid oxide fuel cell (SOFC) applications. In this study, NiO-yttria stabilized zirconia (YSZ) anode and YSZ electrolyte half cells were successfully deposited on porous Hastelloy X substrates by SPS. The NiO-YSZ anode deposition process was optimized by design of experiment. The YSZ electrolyte spray process was examined by changing one parameter at a time. The results from the design-of-experiment trials indicated that the porosity of the as-deposited coatings increased with an increase of suspension feed rate while it decreased with an increase of total plasma gas flow rate and standoff distance. The deposition rate increased with an increase of total plasma gas flow rate, suspension feed rate, and standoff distance. The microstructure examination by SEM showed that the NiO and YSZ phases were homogeneously distributed and that the YSZ phase had a lamellar structure. It was observed that the density of the YSZ electrolyte layer increased as input power of the plasma torch increased. Electrochemical characterization of the fabricated cells indicated that an open cell voltage of 0.989 V at 500 °C and a peak power of 0.610 W/cm2 at 750 °C were reached.

One way to improve the mechanical properties of solid oxide fuel cells is the development of metal supported designs. This type of SOFC offers improved thermal shock resistance, reduced temperature gradients due to the greater thermal conductivity of the metal, and lower operating temperatures. Switching from ceramic supports to metal supports also allows the uses of conventional metal joining and forming techniques and could significantly reduce the material and manufacture costs. However, one persistent problem needs to be solved: inter-diffusion of chemical elements contained in the metal substrates and in the anodes of SOFC leads to degradation, which is to be prevented by protective coatings. In order to address the issues of sintering and delamination for metal supported SOFC, the deposition of gadolinia doped ceria on metal substrates made of Crofer 22 APU has been done by electron beam evaporation and reactive spray deposition technique, as two direct deposition techniques that will not require a sintering step, respectively. Additionally, the effect of ion-assistance on layers made by electron beam evaporation was studied. Because metal supported fuel cells aim at low/intermediate operating temperatures, reducing the thickness of these protective coatings is crucial, since layer thickness is directly correlated to its ohmic resistance. A layer of nickel was applied by magnetron sputtering to prove the effectiveness of the deposited diffusion barrier layers. © 2011 Elsevier B.V.

The present work describes the effect on the performance of a SOFC when a Gd 0.2Ce 0.8O 1.9 (GDC) layer is introduced as diffusion barrier layer between the yttria stabilized zirconia (YSZ) electrolyte and the La 0.6Sr 0.4Co 1-xFe xO 3-δ (LSCF) cathode of an anode supported cell with Ni-YSZ anode. The dense, thin and fully crystalline GDC films were directly applied by RSDT, without any post-deposition heating or sintering steps. The quality of the film and performance of the cell prepared by Reactive Spray Deposition Technology (RSDT) was compared to a GDC blocking layer deposited by screen printing (SP) and then sintered at 1000°C. By applying RSDT to deposit the GDC-barrier layer onto the YSZ electrolyte a lower ohmic resistance was obtained for the RSDT deposited cell vs. the SP cell. The lower resistance can be attributed to the well crystallized, thin and dense GDC layer deposited at 900°C. ©The Electrochemical Society., 12th International Symposium on Solid Oxide Fuel Cells, SOFC-XII - 219th ECS Meeting, 1 May 2011 through 6 May 2011, Montreal, QC

Reactive Spray Deposition Technology (RSDT) is a fabrication process developed for the 1-step deposition of platinum catalyst, carbon support and ionomer directly onto a Nafion® membrane. The process involves pumping a platinumorganic solute dissolved in a combustible solvent through an atomizer. The spray is then combusted and nanosized particles of platinum are produced and subsequently cooled by a gas quench. Once the reaction plume is cooled a secondary set of nozzles is used to inject the carbon support and ionomer. The quench air cools the reactive zone enough to allow direct deposition onto a Nafion® electrolyte or a glassy carbon electrode. This arrangement thus realizes a process for one-step catalyst formation, dispersion onto carbon and direct deposition onto an electrolyte membrane. The independent control of the three components allows for real-time control of the carbon, platinum, and ionomer ratios in the final electrode. In this research work we examine the oxygen reduction reaction via a rotating disc three electrode set-up to understand the intrinsic activity of the as-sprayed platinum. The mass and specific activities were measured in a 0.1 M perchloric acid electrolyte under different deposition conditions and loading was verified by atomic emission spectroscopy inductively coupled plasma (AES-ICP). A range of microscopy images for visualization of the microstructure are also presented. The initial results show that the RSDT technique is capable of producing catalysts with oxygen reduction mass activity at 0.9 V of 200 mA/mgPt rotating at 1600 rpm and 30 °C. © 2011 by ASME., ASME 2011 9th International Conference on Fuel Cell Science, Engineering and Technology. Collocated with ASME 2011 5th International Conference on Energy Sustainability, FUELCELL 2011, 7 August 2011 through 10 August 2011, Washington, DC

InordertoreducethecostofthemanufacturingofSolidOxideFuelCells(SOFC),andtoenablemetalsup-ported cell fabrication, a new fabrication method called Reactive Spray Deposition Technology (RSDT)for direct deposition of the material onto ceramic or metal support for low temperature SOFC is cur-rently being developed. The present work describes the effect on the performance of a SOFC when aGd 0.2 Ce 0.8 O 1.9 (GDC)layerhasbeenintroducedasdiffusionbarrierlayerbetweentheyttriastabilizedzir-conia (YSZ) electrolyte and the La 0.6 Sr 0.4 CoO 3−i (LSC) cathode. The dense, thin and fully crystalline GDClmsweredirectlyappliedbyRSDT,withoutanypost-depositionheatingorsinteringstep.Thequalityofthe lm and performance of the cell prepared by RSDT was compared to a GDC blocking layer depositedby screen printing (SP) and then sintered. The observed ohmic resistance of the ASC with a GDC layerdeposited by RSDT is 0.24cm 2 , which is close to the expected theoretical value of 0.17cm 2 for a5- m thick 8mol% yttria YSZ (8YSZ) electrolyte at 873K.Crown Copyright © 2010 Published by Elsevier B.V. All rights reserved.

To find a more durable anode with high performance for direct ethanol fuel cells (DEFCs), the present study investigates a series of quaternary electrocatalysts, Pt 30 Ru 30 Ir 40− x Sn x /C (wt.%), for the ethanol electro-oxidation reaction (EOR). The carbon-supported Pt 30 Ru 30 Ir 40− x Sn x /C electrocatalysts were prepared by a known impregnation-reduction (borohydride) method. The microstructure and chemical composition were determined by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The activity of the electrocatalysts for EOR was compared to commercial Pt 67 Ru 33 /C (HISPEC5000) using linear sweep voltammetry (LSV) based on similar Pt loading. The results of this study show that electrocatalyst composition with 10 and 20% Ir (wt.%) exhibit higher electrocatalytic activity than the commercial PtRu electrocatalyst. The single fuel cell testing at 90 °C comparing Pt 30 Ru 30 Ir 40− x Sn x /C to commercial Pt 67 Ru 33 /C and Pt 83 Sn 17 /C anodes showed an enhancement of Pt activity (normalized to Pt loading) in the following order: Pt 30 Ru 30 Ir 10 Sn 30 > Pt 30 Ru 30 Sn 40 ≥ Pt 30 Ru 30 Ir 40 ≥ Pt 83 Sn 17 > Pt 67 Ru 33 . After a long-term performance test, the activity changed to the following order: Pt 30 Ru 30 Ir 10 Sn 30 > Pt 30 Ru 30 Ir 40 > Pt 30 Ru 30 Sn 40 > Pt 83 Sn 17 > Pt 67 Ru 33 . Pt 30 Ru 30 Ir 10 Sn 30 /C exhibited both a higher performance with a specific power density of 29 mW mg Pt −1 without O 2 backpressure at the cathode and an excellent long-term stability in a DEFC operating at 90 °C.

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.

The key obstacles to the development of low operating temperature (LT) SOFCs are high ohmic resistance and high electrode overpotentials. In the present work, we demonstrate excellent cell performance at 600 °C on a anode supported bi-layer electrolyte SOFC having a thin RSDT-made cerium gadolinium oxide (Gd0.2 Ce0.8 O2−δ , CGO) and a lanthanum strontium cobaltite (La0.6 Sr0.4 CoO3−δ , LSC) perovskite cathode. The measured ohmic resistance of the ASE cell with CGO layer deposited by RSDT was 0.24 ohm.cm2 , which is close to the expected theoretical value of 0.17 ohm.cm2 for a 5 micron thick 8YSZ electrolyte at 600 °C. This indicates that the obtained peak power output density is approaching what is theoretically possible. This work is based on the lab scale use of Reactive Spray Deposition Technology (RSDT) which is an open atmosphere, cost efficient technique that does not require high vapor precursors and is an effective way to deposit thin ceramic layers of YSZ/CGO/LSC onto Ni-YSZ substrates. It has the potential to chain successive coating steps thus, significantly simplifying the production of multilayered ceramic structures as the SOFCs and reducing the cost associated with manufacturing of the cells.Copyright © 2010 by ASME

Present work presents the results obtained by using a direct deposition technique to make SOFC cathode materials that either significantly reduce or eliminate the need for sintering. A reference composite cathode made of 75 wt.% Sm0.5Sr0.5CoO3 (SSC) and 25 wt.% Sm0.2Ce0.8O1.9 (SDC) has been applied on a cermet supported thin SDC electrolyte cell. Cell peak power performance was measured to be 0.49 W cm−2 operating at 600 {degree sign}C after firing at 1050 {degree sign}C. The measured total electrode polarization Rp(a + c) was 0.102 Ω cm2 at 600 {degree sign}C. In this study a thin (~5 μm) SSC cathode has been applied by Reactive Spray Deposition Technology (RSDT) and the total polarization was reduced to 0.079 Ω cm2, indicating over 20% reduction of losses compared to the traditional cathode processing route., 2008 Fuel Cell Seminar & Exposition, October 27-31, 2008, Phoenix, Arizona, USA

In present work, complex mixtures were designed based on fused SiO(2), beta-SiC and different oxide additives. The addition of Al(2)O(3) and mulite - 3Al(2)O(3) 2SiO(2) influence was investigated in order to obtain high temperature strength, thermal shock resistant and corrosion resistant composites. Thermal treatment was conducted in conventionally electric furnace in air and in argon respectively, in the 800-1250 degrees C temperature range. Sintered composites were characterised by bulk density, open porosity, and thermal shock resistance and thermal expansion measurements. The crystalline phase evolution in conjunction with each heat curing procedure was analysed by X-ray diffraction and FTIR spectrometry. Microstructure investigation of sintered samples was carried using scanning and transmission electron microscopy. The relationship between the FTIR spectra and structure of the powders and sintered composites was explained.

International audience; The deposition of a platinum electrode on 8 mol% Y2O3-stabilized ZrO2 (YSZ) using the electrostatic spray deposition (ESD) technique was investigated. Films with various morphologies were obtained starting from different precursor solutions based on Pt(NH3)4(OH)2(H2O), PtCl4 and Pt(acac)2 dissolved in different solvents. The surface morphology was strongly influenced by the composition of the precursor solution, the deposition temperature, the nozzle to substrate distance, the precursor solution flow rate and the deposition time. The processes involved in the film formation were discussed. Nanocrystalline cubic Pt single-phase was present in the raw film as shown by X-ray diffraction.

International audience; This paper presents the results of a process optimisation study applied to the synthesis of thin 8YSZ films by electrostatic spray deposition (ESD). The goal was to obtain thin, dense and continuous 8YSZ coatings. Starting from a zirconium acetylacetonate in ethanol – butyl carbitol solution as precursor, the influence of the main process parameters – substrate temperature, nozzle to substrate distance and solution flow rate – has been studied. The microstructure has been characterised by SEM imagery. The study allowed us to define a three dimensional domain of optimal values of the process parameters where dense and thin doped zirconia coatings were obtained for the employed nozzle geometry and solution concentration.

International audience; Cubic and tetragonal Y2O3-doped ZrO2 thin films were deposited with a dense surface morphology by electrostatic spray deposition. Four dependent process parameters – substrate temperature, precursor solution flow rate, nozzle to substrate distance and the deposition time – have been used to control the process. Temperature dependent Raman spectroscopy and X-ray diffraction were performed in order to investigate the crystallization behavior and structural properties.

International audience; This study describes the phenomena occurring during the first stages of layer formation in the ESD (electrostatic spray deposition) process. Solutions containing zirconyl nitrate dissolved in a mixture of butyl carbitol−water−ethanol (40:40:20 vol %) have been sprayed on heated glass substrates. The spreading and drying of the droplets and the growth of the coating over a time range of 10 s to 10 min have been studied using SEM and optical microscopy. The influence of the substrate temperature, concentration of the salts, nature, and concentration of polymer additives on the microstructure of the deposited coatings has been studied. This work shows that there is little connection between the evolution of the droplets spreading and the final microstructure of the coating. This is due to the strong effect of the preferential landing and to the presence of a liquid layer at the surface of the coating during the deposition process. These results will contribute to the understanding of the coating formation in the ESD technique. They will finally help to synthesize finely controlled thin layers of zirconia for direct applications as SOFC electrolytes.

International audience; The deposition of (La0.85Sr0.15)0.95MnO3-δ films on an yttria-stabilized zirconia substrate was studied by the electrostatic spray deposition (ESD) technique. Films with various morphologies were obtained. The surface morphology was strongly influenced by the precursor solution flow rate and deposition temperature. Processes involved in the porous film formation were discussed. Powder X-ray diffraction analysis showed that the LSM hexagonal phase was formed and was nanostructured, consisting of crystallites of 60−75 nm on average, after thermal treatment ranging from 600 to 900 °C.

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Direct liquid fuel cells (DLFCs) are promising power sources for small devices operating under ambient conditions, such as electronic portable devices. A one-step, open atmosphere reactive spray deposition technique (RSDT) was used for the first time as a flame-based technique to produce Pt-Sn catalyst for ethanol oxidation reaction. TEM images show catalyst particle size in the range of 2 to 6 nm. XRD patterns confirm crystalline Pt and a possible amorphous to weakly crystallized SnO2 phase. Pt-Sn / 90-10 % showed a superior catalytic performance compared to Pt or Pt-Sn mixtures with higher Sn content., 216th ECS Meeting, October 4-9, 2009, Vienna, Austria

The paper presents an overview of the results obtained by using a newly developed flame based deposition technique to fabricate SOFC components. Gadolinia doped ceria (20% mol gadolinia), yttria stabilised zirconia (8% mol yttria) and samarium strontium cobaltite (50% at Sm) ceramics have been deposited on various substrates, including SOFC anode materials and half cells. Thin and dense electrolyte layers having thicknesses in the range of 100 nm to 2 mm have been successfully fabricated. Porous cathode layers deposited on half cell substrates have shown a 25-30% increase in performance compared to samaria doped ceria - samarium strontium cobaltite screen printed cathodes tested in the same conditions., 216th ECS Meeting, October 4-9, 2009, Vienna, Austria

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Metal-supported solid oxide fuel cells (SOFCs) offer many advantages, including increased robustness, improved thermal shock resistance, and decreased cost. However, fabricating metal-supported SOFCs using conventional techniques is both very difficult and very costly. In this study, two processes of spray pyrolysis deposition, pneumatic spray deposition and electrostatic spray deposition, were used to deposit samaria-doped ceria (SDC) electrolytes on different substrates and NiO-SDC anodes on porous stainless steel substrates. A cathode layer was subsequently applied on the electrolyte by stencil printing for electrochemical testing. The test results indicated that the electrolyte had reasonable cell performance, but the topography of the anode needed optimization. It was also discovered that the porous ferritic stainless steel 430 substrate used in this study did not have sufficient oxidation resistance as the substrate of a metal-supported SOFC.