Metallic interconnects for solid oxide fuel cell: Effect of water vapour on oxidation resistance of differently coated alloys

2009

International audience; The need of interconnect to separate fuel and oxidant gasses and connect individual cells into electrical series in a SOFC stack appears as one of the most important point in fuel cell technology. Due to their high electrical and thermal conductivities, thermal expansion compatibility with the other cell components and lowcost, ferritic stainless steels (FSS) are nowconsidered to be among the most promising candidate materials as interconnects in SOFC stacks. Despite the formation at 800 ◦C of a protective chromia Cr2O3 scale, it can transform in volatile chromium species, leading to the lost of its protectiveness and then the degradation of the fuel cell. A previous…

Synthèse sous champ micro-onde et caractérisation de chromite de lanthane strontium dopé utilisé comme anode de pile à combustible SOFC

2020

National audience

Impedance investigation of BaCe0.85Y0.15O3-delta properties for hydrogen conductor in fuel cells

2012

International audience; The influence of the sintering conditions on the electrochemical properties of the proton conducting electrolyte BaCe0.85Y0.15O3-delta (BCY15) and Ni - based BCY15 cermet anode for application in high temperature proton conducting fuel cell are investigated by electrochemical impedance spectroscopy. The results show that at lower sintering temperatures due to the formation of parasitic Y2O3 phase an increase of both the electrolyte and electrode resistances is observed. This effect is strongly reduced by enhancement of the sintering temperature. The obtained BCY15 conductivity (sigma = 2.5x10(-2) S/cm at 700 degrees C) is comparable with that of the best proton condu…

Microwave synthesis of yttria stabilized zirconia

2005

Yttria stabilised zirconia (YSZ) nanocrystals, with a mean size between 5 and 10 nm, were prepared by microwave flash synthesis. Flash synthesis was performed in alcoholic solutions of yttrium, zirconium chloride and sodium ethoxide (EtONa) using a microwave autoclave (RAMO system) specially designed by authors. Energy dispersive X-ray analysis (EDX), X-ray powder diffraction (XRD), BET adsorption technique, photon correlation spectroscopy (PCS) transmission and scanning electron microscopy (TEM and SEM) are used to characterized these nanoparticles. Compared with conventional synthesis, nanopowders can be produced in a short period (e.g. 10 s), both high purity and stoechiometric control a…

Water vapour solubility and conductivity study of the proton conductor BaCe(0.9−x)ZrxY0.1O(3−δ)

2009

Abstract The perovskite BaCe(0.9 − x)ZrxY0.1O(3 − δ) has been prepared by solid state reaction at 1400 °C and conventional sintering at 1700 °C. Water uptake experiments performed between 400 and 600 °C, at a water vapour pressure of 0.02 atm, provide data on the concentration of protons incorporated in the sample. The direct current conductivity has been measured as a function of oxygen partial pressure, at a water vapour partial pressure of 0.015 atm. The total conductivity has been resolved into a p-type and an ionic component using a fitting procedure appropriate to the assumed defect model. An estimation of the protonic component was made by assuming a conductivity isotope effect betwe…

Mössbauer Study of Lanthanum–Strontium Ferromanganite Oxides

2004

The La0.88Sr0.2Mn(1−y)Fey0(3±δ, i (LSMF with y = 0, 0.2, 0.5, 0.8, 1) compounds are prospective cathode materials for advanced solid oxide fuel cells (SOFC) application operating at 700° C. Usual analysis methods like thermogravimetric analysis or redox titration enable to determine the average oxidation state of both manganese and iron cations. The comparative role of iron and manganese in B-site was evaluated by 57Fe Mossbauer spectroscopy. Spectra revealed that the complete substitution of iron for manganese induces the formation of Fe5+ for the compound with y = 1. However, no tetravalent iron cation was observed in air for the LSMF compounds with y = 0.2, 0.5 and 0.8. This means that o…

Oxygen isotopic exchange: A useful tool for characterizing oxygen conducting oxides

2005

International audience; The 18O/16O isotope exchange depth profile technique (IEDP) followed by SIMS characterizations was applied to dense membranes of pure ionic conductors and mixed ionic/electronic conducting materials. It is a very useful tool since we obtain in both cases data concerning the oxygen diffusion in the bulk and the oxygen exchange at the surface of the materials. Comparisons were done, including results concerning the role of the surface with regards to the oxygen reduction reaction. Detailed experimental and analytical processes are given.

Preparation by radio-frequency magnetron co-sputtering and characterization of thin films of lanthanum–strontium ferromanganites

2005

Abstract (La 0.8 Sr 0.2 )(Mn 1 −  y Fe y )O 3 ± δ films with y  = 0, 0.2, 0.5, 0.8 and 1, a few hundred nanometers thick, were deposited onto polycrystalline yttria-stabilized zirconia YSZ by a magnetron co-sputtering technique using individual targets of La 0.8 Sr 0.2 MnO 3 and La 0.8 Sr 0.2 FeO 3 . The deposition parameters, substrate temperature and gas pressure, were studied by scanning electron microscopy, energy dispersive X-ray spectrometry, X-ray diffraction and interferential microscopy for their effects on the morphological, chemical, topographic and crystallographic properties of films and YSZ-film interfaces. (La 0.8 Sr 0.2 )(Mn 1 −  y Fe y )O 3 ±  δ thin films were found to be …

Metallic interconnects for solid oxide fuel cell: Performance of reactive element oxide coating during long time exposure

2011

One of challenges in improving the performance and cost-effectiveness of SOFCs (solid oxide fuel cells) is the development of suitable interconnects materials. Chromia-forming alloys and especially ferritic stainless steels, like Crofer22APU, are considered to be among the most promising candidate materials as interconnects in SOFC stacks. However, the performance of chromia-forming materials can be limited by the low electronic conductivity of the oxide scale (high ASR – area specific resistance – value). Such degradation are unacceptable regarding the long-term operation (>40 000 h). A previous study 1 demonstrated that in air, the addition of a nanometric reactive element oxide (La2O3) l…

Contribution of Ferroelectric Domains on Diffraction Line Profiles of BaTiO<sub>3</sub>

1993

Desummation of Mixed Powder Diffraction Lines

1991

Crystallographic changes and thermal properties of lanthanum?strontium ferromanganites between RT and 700 �C

2005

Abstract X-ray powder diffraction was used to determine the crystallographic changes between room temperature (RT) and 700 °C of the (La 0.8 Sr 0.2 )(Mn 1− y Fe y )O 3± δ perovskites with y =0.2, 0.5, 0.8, 1 which can be considered as possible cathode materials for the ITSOFCs. For y =0.2, the rhombohedral symmetry was preserved in the whole temperature range. For y =1, a transition from orthorhombic to rhombohedral symmetry occurred at 290 °C. The compounds with y =0.5 and 0.8 were found to be diphasic at RT by combination of both rhombohedral and orthorhombic symmetries. They became only rhombohedral at 80 and 160 °C, respectively. This reversible transition is discussed in terms of iron …

Fundamental and technological aspects of the surface properties and reactivity of some metal oxides

1997

Abstract As is usually accepted for many inorganic compounds, the surface properties often play a fundamental role in the overall properties of metal oxides, in particular when the oxide materials are used in the form of fine grains. One difficulty in characterizing these surface properties is to apply the results of studies performed on ideal surfaces to the actual materials in use. A way to accept this challenge can be to successively consider initial powders, polycrystalline pellets formed after thermal or mechanical treatment of these powders and, finally, monocrystalline surfaces prepared from these powders or pellets. This principle can be applied to the study of the surface propertie…

Structural and conductivity study of the proton conductor BaCe(0.9−x)ZrxY0.1O(3−ı) at intermediate temperatures.

2009

International audience; The perovskite BaCe(0.9−x)ZrxY0.1O(3−ı) is prepared by solid-state reaction at 1400 ◦C and sintering at 1700 ◦C. It is characterised using X-ray diffraction, Raman spectroscopy and electrical measurements. A distortion fromthe cubic structure at roomtemperature is noticeable in the Raman spectra for 0.2 < x < 0.8, but not in the X-ray diffraction patterns. This work points out the rhombohedral nature of this distortion. Phase transitions are studied up to 600 ◦C. The direct current conductivity is measured as a function of oxygen partial pressure, and at a water vapour partial pressure of 0.015 atm. The total conductivity is resolved into an ionic and a p-type compon…

Thermodynamic considerations of the grain size dependency of material properties

1994

Phase transitions which depend on grain size induce very interesting properties in materials such as zirconia or barium titanate. A new and rigorous thermodynamic treatment of this type of phase transition is proposed with consideration of the surface phenomena. An interpretation is given of the observed differences when the material—particularly BaTiO3—under consideration is a fine grain powder or is a fine grain ceramic.

Screening of ceria-based catalysts for internal methane reforming in low temperature SOFC

2010

Gaudillere, Cyril Vernoux, Philippe Mirodatos, Claude Caboche, Gilles Farrusseng, David 6th World Congress on Oxidation Catalysis (6WCOC) JUL 05-10, 2009 Lille, FRANCE; International audience; Ceria-based catalysts have been assessed for internal methane reforming at low temperature (400-600 C) in Solid Oxide Fuel Cell (SOFC) A combinatorial library of 15 metal (Cu Pt Ni) supported ceria was prepared using wet impregnation method The ceria-based oxides are undoped or doped with metal transition (Zr) or by rare earth (Gd or Pr) The effect of the metal the dopant and the surface area on the catalytic performances was investigated in high-throughput manner using a 16-parallel reactor The catal…

A dilatometric study of the Lao.8Sr0.2MnO3 sintering behaviour

1997

Abstract The sintering behaviour of La0.8Sr0.2MnO3 has been studied by dilatometry between 1100 and 1800 K in various oxygen potentials [pure oxygen, air and nitrogen (PO2 = 1 × 10−5 bar)]. The starting material was prepared by spray pyrolysis of aqueous solutions of nitrates. Two classical sinter stages, neck formation and grain growth respectively, were evidenced from dilatometric curves and this result was corroborated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The rate of densification was found to be directly dependent on oxygen partial pressure, the best conditions being in nitrogen. These results are discussed in terms of vacancy diffusion and oxygen …

Interface reactivity study between La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) cathode material and metallic interconnect for fuel cell

2011

Abstract Interface reactivity between La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) cathode material and metallic interconnect (Crofer22APU) was investigated in laboratory air at 700 °C. Due to the interconnect geometry, two interfaces have been analysed: (i) interconnect rib/cathode interface (physically in contact); (ii) the interface under the channel of interconnect. In both cases, formation of a parasite phase was observed after various ageing treatments (20 h, 100 h and 200 h). However, the growth of the determined SrCrO4 parasite phase depends on interface type and on ageing time. Two different mechanisms have been established in function of interface type: (i) SrCrO4 phase was formed after solid …

(La0.8Sr0.2)(Mn1−yFey)O3±δ oxides for ITSOFC cathode materials?

2005

The oxygen transport properties in (La 0.8 Sr 0.2 )(Mn 1-y Fe y )O 3±δ (LSMF) with various iron contents y = 0, 0.2, 0.5, 0.8 and 1 were determined by the IEDP technique. Both oxygen diffusion and surface exchange coefficients were found to be greater for y = 0.8 and 1 than those of LSM (y=0). Moreover, for y ≤0.5, grain boundary diffusion was the rate limiting step especially at lower temperatures. Thus, in the LSMF perovskite materials, the oxygen diffusion via oxygen vacancies is enhanced by Fe. The LSMF electrical performances were measured by impedance spectroscopy. Compared to LSM and LSF (y= 1), porous LSMF cathodes with y= 0.2-0.8 exhibit poor electronic conductivity: Fe, by reducin…

Metallic interconnects for SOFC : characterization of their corrosion resistance in hydrogen/water atmosphere and at the operating temperatures of di…

2006

International audience; Chromia forming alloys are one of the best candidates for the interconnecting materials in solid oxide fuels cells (SOFC). Recent research has enabled to decrease the operating temperature of the SOFC from 1000 °C to 800 °C. However, low electronic conductivity and high volatility of the chromia scale need to be solved to improve performance of interconnects. In the field of high temperature oxidation of metals, it is well known that the addition of reactive elements into alloys or in thin film coatings, improve the oxidation resistance of alloys at high temperature. The elements of the beginning of the lanthanide group and yttrium are the most efficient. The goal of…

On the Effect of Surface Treatment to Improve Oxidation Resistance and Conductivity of Metallic Interconnects for SOFC in Operating Conditions

2008

International audience; Due to the reduction of operating temperature from 1000°C to 800°C, chromia forming alloys are the best candidates for interconnects in Solid Oxide Fuel Cells (SOFCs). These interconnects have to be operational in service conditions, at 800°C in air (cathode side) and in humidified hydrogen (anode side). The performance of the interconnect stainless steels is limited by the oxide scale formation (chromia), the low electronic conductivity of this scale and the possible volatility of chromium oxides. In the field of high temperature oxidation of metals, it is well known that the addition of a nanometric layer made of reactive element oxide such as, La2O3, Nd2O3 and Y2O…

An X-ray powder diffraction study of lanthanum–strontium ferromanganites

2001

Abstract Various lanthanum–strontium ferromanganites (La 1− x Sr x )(Mn 1− y Fe y )O 3± δ (LSMF) with x =0.2, 0.5 and 0.7 and y =0.2, 0.5 and 0.8 were prepared by a glycine–nitrate combustion route and conditioned into two different oxygenation states which are likely to be encountered in cathode materials for solid oxide fuel cells (SOFC). Crystal symmetries for both the low and the fully oxygenated states were determined by X-ray diffractometry. Most perovskite compositions crystallized in either cubic or rhombohedral symmetry with the exception of La 0.5 Sr 0.5 Mn 0.2 Fe 0.8 O 3± δ , where a transition from rhombohedral to cubic occurred in going from the full to the low oxygenation stat…

Continuous hydrothermal synthesis in supercritical conditions as a novel process for the elaboration of Y-doped BaZrO3

2021

Abstract The present work describes a novel process for the elaboration of a ceramic material. Y-doped barium zirconate, an electrolyte material for Protonic Ceramic Fuel cell, was synthesized by a continuous hydrothermal process in supercritical conditions (410 °C/30.0 MPa) using nitrate precursors and NaOH reactants. The use of supercritical water allowed the formation of particles of about 50 nm in diameter with a narrow size distribution. X-Ray Diffraction examination revealed that a major perovskite phase with few BaCO3 and YO(OH) impurities was obtained. BaCO3 is assumed to form due to faster kinetics than Y-doped BaZrO3 resulting in a Ba-deficient perovskite phase. The Ba-deficiency …

Metallic interconnects for SOFC: Characterisation of corrosion resistance and conductivity evaluation at operating temperature of differently coated …

2007

Abstract One of challenges in improving the performance and cost-effectiveness of solid oxide fuel cells (SOFCs) is the development of suitable interconnect materials. Recent researches have enabled to decrease the operating temperature of the SOFC from 1000 to 800 °C. Chromia forming alloys are then among the best candidates for interconnects. However, low electronic conductivity and volatility of chromium oxide scale need to be solved to improve interconnect performances. In the field of high temperature oxidation of metals, it is well known that the addition of reactive element into alloys or as thin film coatings, improves their oxidation resistance at high temperature. The elements of …

Flash microwave synthesis and sintering of nanosized La0.75Sr0.25Cr0.93Ru0.07o3–δ for fuel cell application.

2009

International audience; Perovskite-oxide nanocrystals of La0.75Sr0.25Cr0.93Ru0.07O3–δ with a mean size around 10 nm were prepared by microwave flash synthesis. This reaction was performed in alcoholic solution using metallic salts, sodium ethoxide and microwave autoclave. The obtained powder was characterised after purification by energy dispersive X-ray analysis (EDX), X-ray powder diffraction (XRD), BET adsorption technique, photon correlation spectroscopy (PCS) and transmission electron microscopy (TEM). The results show that integrated perovskite-type phase and uniform particle size were obtained in the microwave treated samples. At last the synthesised powder was directly used in a sin…

Design of experiment approach applied to reducing and oxidizing tolerance of anode supported solid oxide fuel cell. Part I: Microstructure optimizati…

2011

The main drawback of Ni/YSZ anode supports for solid oxide fuel cell application is their low tolerance to reducing and oxidizing (RedOx) atmosphere changes, owing to the Ni/NiO volume variation. This work describes a structured approach based on design of experiments for optimizing the microstructure for RedOx stability enhancement. A full factorial hypercube design and the response surface methodology are applied with the variables and their variation range defined as: (1) NiO proportion (40-60 wt% of the ceramic powders), (2) pore-former proportion (0-30 wt% corresponding to 0-64 vol.%), (3) NiO particle size (0.5-8 mu m) and (4) 8YSZ particle size (0.6-9 mu m).

Cell Parameters of Fine-Grain BaTiO&lt;sub&gt;3&lt;/sub&gt; Powders

1993

Investigation of La2O3 and/or (Co,Mn)3O4 deposits on Crofer22APU for the SOFC interconnect application

2009

International audience; Chromia forming alloys (stainless steels) are among the best candidates for SOFC interconnects. However, problems of decreasing electronic conductivity during high temperature service and volatility of chromium oxide scales need to be solved. Electronically conductive surface coatings, which also reduce oxide scale growth and chromium volatility, are needed to improve stainless steel interconnects. The goal of this study is to investigate combinations of lanthanum oxide (La2O3) and cobalt manganese oxide ((Co,Mn)3O4) coatings on Crofer22APU stainless steel. Thin film coatings of La2O3 (~200 nm) and Co,Mn (1:1) (~2 mm) were deposited via metal organic chemical vapor d…

A comparative study of the surface and bulk properties of lanthanum-strontium-manganese oxides La1−xSrxMnO3±δ as a function of Sr-content, oxygen…

1999

Abstract The properties of the perovskite-type La 1− x Sr x MnO 3± δ oxides (0≤ x ≤1) are related to the reversible redox reaction of manganese ions Mn 3+ ↔Mn 4+ . This reaction plays an essential role both in the interfacial transfers and transport properties and depends on relative cation concentrations and experimental conditions. In this paper we present experimental investigations aiming to determine, to compare and to control some of the surface and bulk properties of these oxides. The bulk and surface Mn 4+ contents were investigated by thermogravimetry analysis (TGA) in hydrogen and X-ray photo-electron spectroscopy (XPS) respectively. With a finely divided La 0.8 Sr 0.2 MnO 3 powde…

Opportunity of metallic interconnects for ITSOFC : Reactivity and electrical property.

2006

International audience; Iron-base alloys (Fe-Cr) are proposed hereafter as materials for interconnect of planar-type intermediate temperature solid oxide fuel cell (ITSOFC); they are an alternative solution instead of the use of ceramic interconnects. These steels form an oxide layer (chrornia) which protects the interconnect from the exterior environment, but is an electrical insulator. One solution envisaged in this work is the deposition of a reactive element oxide coating, that slows down the formation of the oxide layer and that increases its electric conductivity. The oxide layer, formed at high temperature on the uncoated alloys, is mainly composed of chromia; it grows in accordance …

Initial Preparation and Characterization of Single Step Fabricated Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFC)

2013

In this study, facile tape casting process has been successfully carried out to fabricate an unit anode supported intermediate temperature solid oxide fuel cell (IT-SOFC) with four different layers: a composite cathode which is a mix of La0.6Sr0.4Co0.2Fe0.8O3 (LSCF48) and Gd0.1Ce0.9O1.9 (GDC10), GDC10 as thin electrolyte layer, NiO-GDC10 without pore former as thin anode functional layer (AFL), and anode support layer of NiO-GDC10 with carbon pore former. The multi-layer was sintered once to produce an unit planar cell. An OCV of 1.002 V at 500 °C, and maximum power density of 466 mW cm–2 at 648 °C are obtained. These results indicate negligible leakage of fuel through electrolyte. Furtherm…

Low-pressure-MOCVD LaMnO3±δ very thin films on YSZ (100) optimized for studies of the triple phase boundary

2000

Abstract This paper deals with the preparation of LaMnO 3± δ (LM) layers by low pressure-metal organic chemical vapor deposition (LP-MOCVD) using La(tmhd) 3 and Mn(acac) 3 as organometallic precursors. By thermogravimetric analysis, these precursors were found to be suitable for LP-MOCVD in a well-defined range of total pressure and temperature of sublimation. The activation energies of the sublimation process were found to be independent of the pressure within the appropriate range (0.06–3 kPa) and their values were 177 and 100.5 kJ mol −1 for La(tmhd) 3 and Mn(acac) 3 , respectively. LM layers of various thickness ranging between a few and a few hundred nanometers with a controlled La/Mn …

OXYDATION D'INTERCONNECTEURS METALLIQUES DE PILE A COMBUSTIBLES DE TYPE SOFC SOUS HYDROGENE ENRICHI EN VAPEUR D'EAU

2008

Les interconnecteurs représentent une pièce maîtresse des piles à combustibles à oxyde solide (Solid Oxide Fuel Cells : SOFCs) car ils sont chargés de collecter et de délivrer le courant produit par la pile. Les matériaux d'interconnecteurs sont à la fois en contact avec l'anode et la cathode et doivent donc être parfaitement stables dans l'air (côté cathodique) et dans l'hydrogène enrichie en vapeur d'eau (côté anodique). Les matériaux métalliques les plus prometteurs sont les chromino-formeurs. Ces alliages sont choisis car, à haute température, ils forment une couche de chromine, Cr2O3, protectrice vis-à-vis des conditions corrosives de fonctionnement de la pile. Cependant, cette couche …

INTERCONNECTEURS METALLIQUES DE PILES A COMBUSTIBLES DE TYPE SOFC : EFFET DE LA VAPEUR D'EAU SUR LA RESISTANCE A LA CORROSION

2008

Les interconnecteurs représentent une pièce maîtresse des piles à combustibles à oxyde solide (Solid Oxide Fuel Cells : SOFCs) car ils sont chargés de collecter et de délivrer le courant produit par la pile. Les matériaux d'interconnecteurs sont à la fois en contact avec l'anode et la cathode et doivent donc être parfaitement stables dans l'air (côté cathodique) et dans l'hydrogène enrichie en vapeur d'eau (côté anodique). Les matériaux métalliques les plus prometteurs sont les chromino-formeurs. Ces alliages sont choisis car, à haute température, ils forment une couche de chromine, Cr2O3, protectrice vis-à-vis des conditions corrosives de fonctionnement de la pile. Cependant, cette couche …

Evaluation of Haynes230 for Solid Oxide Fuel Cell Interconnect Application

2008

National audience; Abstract - Interconnects are among the most critical parts for commercialization of SOFCs. They separate the fuel and oxidant gases and provide electric connection between the anode and cathode of adjacent cells. A Ni-based alloy, Haynes230 alloy, was evaluated in this work as a candidate material for SOFC interconnects application. During operation, a scale of chromia forms on Haynes230. Unfortunately, this scale can degrade the fuel cell performances. Thus, protective coatings are required to increase long-term stability. In this study, a nanometric layer made of reactive element oxide (La2O3, Nd2O3 and Y2O3) was applied on alloy surface by MOCVD. Perovskite oxides, suc…

Continuous hydrothermal synthesis of doped barium zirconate powder for PCFC (Protonic Ceramic Fuel Cell) application

2019

International audience; BaZr 1-x M x O 3-d (M=Ce and/or Y) perovskite materials are good potential candidates for Protonic Ceramic Fuel Cell (PCFC) electrolyte due to their remarkable property of protonic conduction at intermediate temperature (400-600°C). Fabbri et al. have reported a protonic conductivity of 2.10-2 S.cm-1 at 600°C for BaCe 0.7 Zr 0.1 Y 0.2 O 3-d [1]. However, the synthesis of these materials requires high temperature (1500°C) by solid state reaction. The hydrothermal synthesis in supercritical water appears then as a way to synthetize perovskite materials at a temperature as low as 400°C. Furthermore, this process allows the formation of nanometric powder. Finally the con…

Interconnecteurs métalliques de piles à combustibles de type SOFC : effet d'un traitement de surface par MOCVD.

2007

Les performances des alliages chromino-formeurs, utilisés comme interconnecteurs de piles à combustibles sont limitées par la formation d'une couche de chromine qui a une conductivité électrique faible et par la volatilisation des oxydes de chrome qui polluent la pile, et par conséquent détériorent son comportement. La réalisation d'une couche nanométrique d'oxydes d'éléments réactifs (La2O3, Y2O3, Nd2O3) par MOCVD permet d'améliorer la résistance à la corrosion à 800°C des alliages chromino-formeurs. Ces revêtements ont été réalisés sur l'alliage Crofer22APU dans le but de former des oxydes de type pérovskite tels que LaCrO3, NdCrO3 et YCrO3 lors de l'oxydation et qui possèdent une meilleu…

Metallic interconnects for SOFC: competitive effect of water vapour and oxygen on the oxidation behaviour of ferritic stainless steel.

2009

Due to their low environmental impact, their high efficiency and their fuel flexibility, Solid Oxide Fuel Cells are studied for many years in order to supply electricity without fossil sources. The need of interconnect to create a stack (providing electrical connection between anode and cathode) and seal every single cell (having to avoid any contact between air and fuel) appears as a crucial point. Ferritic Stainless Steel (FSS) like Crofer22APU are considered as good candidates for interconnects. These chromia forming alloys have to be operational in the service conditions: 800°C in air (cathode side) and in humidified hydrogen (anode side). The performance of the interconnect stainless s…

Metallic interconnects for SOFC: effect of water vapour on oxidation resistance of differently coated alloys.

2008

The need of interconnect to separate fuel and oxidant gasses and connect individual cells into electrical series in a SOFC stack appears as one of the most important point in fuel cell technology. Due to their high electrical and thermal conductivities, thermal expansion compatibility with the other cell components and low cost, Ferritic Stainless Steels (FSS) are now considered to be among the most promising candidate materials as interconnects in SOFC stacks. Despite the formation at 800°C of a protective chromia Cr2O3 scale, it can transform in presence of water vapour in volatile chromium species leading to the lost of its protectiveness and then the degradation of the fuel cell. A prev…