Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M8/00—Fuel cells; Manufacture thereof
  • H01M8/02—Details
  • H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
  • H01M8/0204—Non-porous and characterised by the material
  • H01M8/0223—Composites
  • H01M8/0228—Composites in the form of layered or coated products
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
  • C25B9/60—Constructional parts of cells
  • C25B9/65—Means for supplying current; Electrode connections; Electric inter-cell connections
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
  • C25B9/70—Assemblies comprising two or more cells
  • C25B9/73—Assemblies comprising two or more cells of the filter-press type
  • C25B9/75—Assemblies comprising two or more cells of the filter-press type having bipolar electrodes
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
  • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
  • C25B9/70—Assemblies comprising two or more cells
  • C25B9/73—Assemblies comprising two or more cells of the filter-press type
  • C25B9/77—Assemblies comprising two or more cells of the filter-press type having diaphragms
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M8/00—Fuel cells; Manufacture thereof
  • H01M8/02—Details
  • H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
  • H01M8/023—Porous and characterised by the material
  • H01M8/0241—Composites
  • H01M8/0243—Composites in the form of mixtures
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M8/00—Fuel cells; Manufacture thereof
  • H01M8/10—Fuel cells with solid electrolytes
  • H01M8/12—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte
  • H01M8/124—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte characterised by the process of manufacturing or by the material of the electrolyte
  • H01M8/1246—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte characterised by the process of manufacturing or by the material of the electrolyte the electrolyte consisting of oxides
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M8/00—Fuel cells; Manufacture thereof
  • H01M8/10—Fuel cells with solid electrolytes
  • H01M8/12—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte
  • H01M2008/1293—Fuel cells with solid oxide electrolytes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/30—Hydrogen technology
  • Y02E60/50—Fuel cells

Definitions

• This presentation relates to a component for a fuel cell or electrolyzer with solid oxide electrolyte provided with an anti-corrosion coating, as well as such a fuel cell or electrolyzer with solid oxide electrolyte.
• Such a component having an electrical conduction function, can in particular equip a solid oxide fuel cell (SOFC: “Solid Oxide Fuel Cell”), a proton ceramic fuel cell (PCFC: “Protonic Ceramic Fuel Cell”) or even a direct carbon fuel cell (DCFC: “Direct Carbon Fuel Cell”).
• SOFC Solid Oxide Fuel Cell
• PCFC proton ceramic Fuel Cell
• DCFC Direct Carbon Fuel Cell
• the conductive components such as terminal plates, bipolar plates and interconnectors, used in fuel cells are exposed both to oxidizing conditions, due in particular to the presence of dioxygen and/or water, and to corrosive conditions, due in particular to acid effluents from the electrolyte, extremely hard leading, in the absence of adequate protection, to rapid deterioration inducing a loss of conductivity of these components as well as environmental pollution. of the fuel cell, in particular its electrolyte and/or its catalysts, by the products resulting from this corrosion.
• a second option is to use more conventional materials for such conductive components but to protect them using an anti-corrosion coating. Many materials have thus been tested in the scientific literature, and in particular coatings of graphite or conductive metal oxides.
• this anti-corrosion coating must have good stability and sufficient electrical conductivity so as not to impede the electrical operation of the fuel cell.
• the conductivity of the coating must remain above 100 S(siemens)/cm.
• the coating must be sufficiently thin, for example less than 5 ⁇ m, so as not to modify the geometry of the component, particularly when the latter comprises channels.
• This presentation relates to a component for a fuel cell or electrolyzer with a solid oxide electrolyte, comprising a substrate, an electrical conductor, and an anticorrosion coating deposited on at least one surface of the substrate, in which the anticorrosion coating comprises at least one main layer based on tantalum nitride doped with one or more doping elements chosen from the family of transition metals or lanthanides.
• such a layer of tantalum nitride doped in this way offers very good protection against corrosion while benefiting from good electrical conductivity.
• the inclusion of one or more dopants makes it possible to increase the chemical stability of tantalum nitride, which is usually metastable, by forming solid solutions.
• the component thus obtained is therefore capable of ensuring its function of current conduction in an efficient and durable manner, despite the highly oxidizing conditions prevailing in the fuel cell or the electrolyser.
• the coating practically does not degrade over time: this reduces the risk, on the one hand, of seeing the conductivity of the component drop over time and, on the other hand, of polluting the environment of the fuel cell or the electrolyser, in particular its electrolyte or its catalysts, and therefore of reducing its efficiency.
• a coating makes it possible to achieve an extremely long service life for the component, of the order of 20,000 to 30,000 hours.
• the cost of obtaining a doped tantalum nitride coating is significantly lower than that of a pure gold coating, which makes it possible to greatly reduce the overall cost of the fuel cell or of the electrolyser.
• Tantalum nitride also has the advantage of remaining stable up to approximately 3000° C., which allows its use in a very broad spectrum of applications, including at very high temperatures.
• the main layer is essentially made of tantalum nitride doped with one or more doping elements chosen from the family of transition metals or lanthanides.
• the main layer is thus essentially uniform.
• the main layer is two-phase or multi-phase.
• the main layer may have a composition gradient, for example in the direction perpendicular to the substrate.
• the main layer is made essentially of tantalum nitride.
• the main layer may have a variation in composition affecting the crystalline structure and/or the doping of the tantalum nitride.
• a crystalline structure gradient has the advantage of improving the accommodation of stresses between the coating and its substrate, which improves the mechanical properties of the complete system, by limiting cracks and/or delamination of the coating.
• the electrolyte of the fuel cell or of the electrolyser is a ceramic, preferably a zirconia stabilized with yttrium oxide (YSZ: “Yttria-stabilized zirconia”).
• the electrolyte of the fuel cell or of the electrolyser is a proton exchange ceramic.
• the component has an electrical conduction function within the fuel cell or the electrolyser.
• the component can be a terminal plate, a bipolar plate or even an interconnector for a fuel cell or electrolyser.
• the preferably single doping element used is yttrium (Y). Indeed, in most solid oxide electrolyte fuel cells, the electrolyte already comprises yttrium. Thus, even if a small fraction of the yttrium from the coating is found released into the medium of the fuel cell, its impact will be reduced since it will not affect the electrolyte.
• the content of the main dopant within the main layer is between 1 ppm and 10% at, preferably between 10 ppm and 1% at, more preferably between 0.2 and 0.5% at.
• each layer of the coating comprises a thickness comprised between 1 and 500 nm, preferably between 10 and 100 nm.
• the uppermost layer of the anticorrosion coating is a main layer made of the main material.
• the first line of protection is thus ensured by the main material, which is generally the one with the best anti-corrosion properties.
• the uppermost layer of the anticorrosion coating could be a secondary layer.
• the main material constitutes at least 30% by volume, preferably at least 50% by volume, of the anticorrosion coating. Overall, this ensures particularly high corrosion protection.
• the anticorrosion coating comprises alternating layers based alternately on the main material and on the secondary material. Such alternation is particularly effective in stopping cracks before they reach the substrate.
• the secondary material is crystallographic tantalum nitride having a crystalline system and/or a different doping from the main material.
• the secondary material may comprise one or more different doping elements, or else be undoped. In this way, the secondary material has anti-corrosion properties that remain very high, which makes it possible to ensure satisfactory anti-corrosion protection even in the event of cracking of the main layer.
• the secondary layer consists essentially of the secondary material.
• the secondary layer is two-phase or multi-phase.
• the secondary layer may have a composition gradient, for example in the direction perpendicular to the substrate.
• the secondary layer is made essentially of tantalum nitride.
• the secondary layer may have a variation in composition affecting the crystalline structure and/or the doping of the tantalum nitride.
• layers with a crystalline structure gradient have the advantage of improving the accommodation of stresses between a given layer and the layer below, which improves the mechanical properties of the complete system, by limiting cracks and/or delamination of the coating at the interfaces.
• the doping gradient can likewise make it possible to best accommodate two successive layers, avoiding a sudden change in composition which could generate a mechanically more fragile interface.
• the main layer is deposited using a co-sputtering process.
• This co-sputtering method can in particular combine high-power pulsed magnetron sputtering (designated by the acronym “HiPIMS” in the English-language literature for “High-Power Impulse Magnetron Sputtering”) using a tantalum target and magnetron sputtering using a target comprising the doping element. Examples of process high-power pulsed magnetron cathode sputtering are described in particular in document FR 3 097 237.
• This presentation also relates to a fuel cell or an electrolyser, with solid oxide electrolyte, comprising at least one component according to any one of the preceding embodiments.
• the fuel cell is of the solid oxide fuel cell (SOFC) type.
• SOFC solid oxide fuel cell
• the fuel cell is of the direct carbon fuel cell (DCFC) type.
• DCFC direct carbon fuel cell
• the fuel cell is configured to be supplied with gaseous fuel.
• the fuel cell is configured to be supplied with dihydrogen H 2 , ammonia NH 3 or methane CH 4 .
• the fuel cell is configured to be supplied with a fuel rich in carbon C, preferably based on coal or biomass.
• a part or part of a part is made from a given material when this material represents the majority material, by mass, in the composition of the part or part of a part.
• a part or part of a part is essentially made of a given material when it is formed at least 80%, preferably 90%, more preferably 99%, by this material.
• Figure 1 is a schematic view of a fuel cell according to the description.
• Figure 2 is a diagram of a cell of the fuel cell of Figure 1.
• Figure 3 is a schematic view of a first example of a component.
• Figure 4 schematically illustrates a device for producing a coating according to the description.
• FIG. 5 is a graph illustrating results of corrosion tests within the framework of the first example.
• Figure 6 illustrates, in section and from the front, the microstructure of a cubic TaN coating deposited by a high power pulsed magnetron cathode sputtering process.
• Figure 7 is a graph illustrating corrosion test results for a second example.
• Figure 8 is a schematic view of a third example component.
• Figure 9 is a graph illustrating results of corrosion tests in the context of the third example.
• FIG. 10 illustrates, in section and from the front, the microstructure of a hexagonal TaN coating deposited by a high power pulsed magnetron cathode sputtering process.
• FIG. 11 illustrates in a comparative manner, in section and from the front, the microstructure of a hexagonal TaN coating deposited by a conventional magnetron sputtering process.
• FIG. 1 schematically illustrates a fuel cell 1 according to the invention.
• a fuel cell comprises two end plates 11,
• Each cell 20 comprises, in order (from left to right in FIG. 1), a first bipolar plate 21, a first diffusion layer 22, a first electrode 23, an electrolyte 24, a second electrode 25, a second diffusion layer 26 and a second bipolar plate 27.
• the function of the bipolar plates 21, 27 is to distribute the reagents and, where appropriate, the heat transfer fluid which cools the cell when said cell has reached its nominal operating speed: the bipolar plates 21, 27 are thus provided with a network of channels 21a, 27a on each of their faces.
• the bipolar plates 21, 27 also have the function of conducting an electric current between the successive cells 20.
• each bipolar plate 21, 27 is located at the interface between two successive cells 20, the second bipolar plate 27 of the N th cell 20 constituting the first bipolar plate 21 of the (N+1) th cell 20, thus electrically connecting the N e and (N+1) th cells 20 in series.
• the anticorrosion coating 232 comprises two types of layers 233 deposited alternately: main layers 233a, made of a main material, and secondary layers 233b, made of a secondary material.
• main layers 233a made of a main material
• secondary layers 233b made of a secondary material.
• the main material i.e. the material of the main layers 233a
• the main material is cubic tantalum nitride TaN doped with zirconium Zr.
• this main material may correspond to the material of the anticorrosion coating 32 of the first embodiment.
• This multilayer anticorrosion coating 232 can be deposited on the substrate 231 using the same device 50 shown schematically in Figure 4 and described in the context of the first embodiment. Indeed, the main layers 233a can be deposited by co-sputtering as described above; the secondary layers 233b can for their part be deposited by high-power pulsed magnetron cathode sputtering using the first target 52 alone, that is to say by not applying any power to the second target 53. Thus, it is possible to produce all of the layers 233 of the coating 232 in a single step and using a single device 50, by controlling over time the electrical biases applied to each of the targets 52, 53.
• the pressure in chamber 51 is set at 5 mTorr, ie around 0.7 Pa; the gas mixture is composed of argon and nitrogen with 25% at nitrogen.
• the main layers are deposited with the same pulse parameters as those of the first embodiment.
• the secondary layers are deposited with the following pulse parameters: width of the pulses equal to 50 ps; pulse frequency equal to 1000 Hz; and voltage of the draws equal to 700V.
• FIG. 9 illustrates for its part the results of corrosion tests concerning the secondary material. This cyclic voltammetry test was carried out under the same conditions as the test carried out for the first embodiment, except that the working electrode was tested in several baths of phosphoric acid at increasing concentrations: 0.1 mol/L; 0.5 mol/L; and 1 mol/L.
• Curve 261 corresponds to a concentration of the bath at 0.1 mol/L
• Curve 262 corresponds to a bath concentration of 0.5 mol/L
• Curve 263 corresponds to a bath concentration of 1 mol/L.
• the curves 261, 262 and 263, corresponding to the secondary material also have stability levels that are significantly wider than that of the substrate 231 made of 316L stainless steel.
• FIG. 10 illustrates the microstructure of a hexagonal tantalum nitride coating, in cross-section and face-on, deposited by a high-power pulsed magnetron cathode sputtering method in accordance with the present example.
• the scale shown at the bottom of each view corresponds to 1 ⁇ m.
• the microstructure of the coating is fine and homogeneous, which implies good mechanical strength with, in particular, good resistance to the propagation of cracks within the coating.
• such a coating deposited by a conventional magnetron sputtering process leads to an easily fracturable columnar microstructure, as can be seen in FIG. 11.
• the inventors determined that the cubic and hexagonal phases of tantalum nitride had significantly different Young's moduli. Indeed, the Young's modulus measured by nano-indentation of the phase cubic is 430 GPa while that of the hexagonal phase is 560 GPa.
• hexagonal tantalum nitride benefits from an even higher conductivity than that of cubic tantalum nitride, which further improves its electrical conduction function.
• the conductivity of cubic tantalum nitride deposited by high-power pulsed magnetron sputtering is equal to 4045 S/cm.
• the main material is doped cubic tantalum nitride while the secondary material is undoped hexagonal tantalum nitride.
• the secondary material is undoped hexagonal tantalum nitride.
• other multilayer configurations are also possible.
• the main material may be hexagonal tantalum nitride, or biphasic tantalum nitride, predominantly cubic or hexagonal.
• the main material can also comprise a different doping element or even one or more additional doping elements.
• the secondary material can be doped.
• the crystal system of the second material is the same as that of the main material, the doping will preferably be different from that of the main material.
• the coating comprises alternating layers of doped hexagonal tantalum nitride and undoped hexagonal tantalum nitride.
• the coating comprises alternating layers of doped hexagonal tantalum nitride and cubic tantalum nitride, doped or not.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Electrochemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Manufacturing & Machinery (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Composite Materials (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Physical Vapour Deposition (AREA)
• Fuel Cell (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=81448514

Family Applications (1)

Country Status (5)

Families Citing this family (2)

Family Cites Families (5)

• 2022
  • 2022-01-21 FR FR2200499A patent/FR3132171B1/fr active Active
• 2023
  • 2023-01-17 US US18/730,193 patent/US20250112250A1/en active Pending
  • 2023-01-17 WO PCT/FR2023/050058 patent/WO2023139327A1/fr not_active Ceased
  • 2023-01-17 CN CN202380018096.1A patent/CN118786548A/zh active Pending
  • 2023-01-17 EP EP23703098.6A patent/EP4466744A1/de active Pending

Also Published As

Similar Documents

Legal Events