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
  • H01M8/0258—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
  • H01M8/0265—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant the reactant or coolant channels having varying cross sections
• • 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
  • H01M8/0258—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
  • H01M8/0263—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant having meandering or serpentine paths
• • 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
  • H01M8/0267—Collectors; Separators, e.g. bipolar separators; Interconnectors having heating or cooling means, e.g. heaters or coolant flow channels
• • 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
  • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
  • H01M8/04007—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids related to heat exchange
  • H01M8/04029—Heat exchange using liquids
• • 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
  • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
  • H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
  • H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
  • H01M8/04119—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants with simultaneous supply or evacuation of electrolyte; Humidifying or dehumidifying
  • H01M8/04156—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants with simultaneous supply or evacuation of electrolyte; Humidifying or dehumidifying with product water removal
• • 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
  • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
  • H01M8/04291—Arrangements for managing water in solid electrolyte fuel cell systems
• • 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
  • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
  • H01M8/04298—Processes for controlling fuel cells or fuel cell systems
  • H01M8/04694—Processes for controlling fuel cells or fuel cell systems characterised by variables to be controlled
  • H01M8/04701—Temperature
• • 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
  • H01M8/1004—Fuel cells with solid electrolytes characterised by membrane-electrode assemblies [MEA]
• • 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
  • H01M2008/1095—Fuel cells with polymeric electrolytes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2250/00—Fuel cells for particular applications; Specific features of fuel cell system
  • H01M2250/20—Fuel cells in motive systems, e.g. vehicle, ship, plane
• • 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

• the present application relates to the field of fuel cells and in particular that of hydrogen cells including PEMFC type (acronym for "Polymer Electrolyte Membrane Fuel Cells” or “Proton Exchange Membrane Fuel Cells”).
• PEMFC type acronym for "Polymer Electrolyte Membrane Fuel Cells” or “Proton Exchange Membrane Fuel Cells”
• a fuel cell 1 is a chemical energy converter into electrical energy having at least one electrochemical cell 2 comprising an anode 4 separated from a cathode 6 by an electrolyte 8.
• the electrochemical cell of a hydrogen cell is generally fed by two different gases, the first of the hydrogen oxidizing in contact with the anode, the second of oxygen or air reduced in contact with the cathode according to the following electrochemical reactions:
• the oxidation produces electrons flowing from the anode 4 to the cathode 6 via an electrical circuit 10 external to the cell, so that an element 12 integrated in this electrical circuit 10 can be supplied with electricity by the battery.
• the membrane 8 separating the electrodes 4, 6 is generally made of porous material and electrically insulating, but ionic conductor.
• PEMFC fuel cell cells typically have an electrolyte in the form of a polymer-based proton exchange membrane, particularly fluoropolymer.
• a PEMFC fuel cell is typically made by stacking elementary cells, each cell being formed between a face of a bipolar plate, of an element named AME (for "membrane electrode assembly” here corresponding to cathode cathode stack stacking) and a face of another bipolar plate.
• AME for "membrane electrode assembly” here corresponding to cathode cathode stack stacking
• Bipolar plates have several functions:
• Bipolar plates are generally provided with splines or channels on each side, the channels of a first face for the supply of hydrogen, while the channels of a second face opposite the first face allow the supply of oxygen.
• the reactants are thus introduced to the electrodes 4, 6 via the supply channels present in the bipolar plates 13, these supply channels also making it possible to evacuate the product from the electrochemical reactions.
• the volume delimited by a feed channel and an electrode forms an anode compartment 14 when the electrode is the anode, or a cathode compartment 16, when the electrode is the cathode (FIG. 1).
• One embodiment of the present invention provides a bipolar conductive plate adapted to be interposed in a fuel cell structure, said plate having on a first external face, a first network of one or more fluid circulation channels arranged in parallel. and each having a path in the form of a succession of corrugations.
• the channels make it possible, by using centrifugal force, to avoid stagnation and the formation of water plugs and thus to promote the gas flow in the channels. She participates in obtaining a better return.
• the channels further advantageously comprise narrowed cross-sectional portions. Such a shape of the channels makes it possible locally to create gas accelerations conveyed by the channels. Combined with the wavy shape, the narrowed portions contribute to better gas flow in the channels.
• the portions of narrowed cross section are regularly distributed, ie periodic according to a predetermined period in the path of said channels.
• the narrowed cross section portions are distributed at vertices or recessed areas of said corrugations.
• the bipolar conductive plate may also comprise, on a second external face opposite to said first external face, a second network of fluid circulation channels also in the form of a succession of corrugations.
• the channels of the second network also preferably include portions of narrowed cross-section.
• a particular embodiment provides that the ripples of the channels of the second network may be arranged in phase shift or advantageously in phase opposition with respect to the ripples of the channels of said first channel network.
• the second network typically has a larger number of channels than the first network.
• the bipolar conductive plate in which said first external face is a face of a first sheet joined to a second sheet, one face forms said second outer face, the channels of the first network being grooves made in the first sheet, the channels of the second network being grooves made in the second sheet, the grooves of the first network and the grooves of the second network being supported against each other at several points, the grooves of the first network being arranged relative to each other; to the grooves of the second network so as to provide a volume for the coolant passage.
• the present invention also relates to a fuel cell structure provided with one or more bipolar conductive plate (s) as defined above.
• a first bipolar plate located on a first side of the electrode membrane assembly and provided with an array of anode channels in the form of a succession of corrugations
• a second bipolar plate located on a second side of the electrode membrane assembly and provided with an array of cathode channels in the form of a succession of corrugations, the undulations of the cathode channel array being in phase opposition with respect to the corrugations of the anodic channels or having a path having inverted radii of curvature relative to a path of the anode channels.
• Such a configuration also allows a better distribution of water on both sides of the membrane and thus improve the performance of a cell with such plates.
• the present invention also provides a vehicle with a fuel cell comprising at least one bipolar conductive plate as defined above.
• Figure 1 schematically illustrates a fuel cell and its bipolar plates.
• FIGS. 2A-2B illustrate a bipolar conductive plate provided with anode and cathode channel networks of slightly undulating shape.
• FIG. 3 illustrates a particular configuration of anode or cathode channels in the form of wave succession and with portions of narrowed sections.
• FIGS. 4A-4B illustrate an assembly of sheets forming a bipolar conductive plate with corrugated cathode and anode channels and arranged so as to form support zones between the plates allowing improved mechanical strength as well as spaces formed between the sheets to allow the displacement of a coolant.
• FIG. 5 illustrates a particular configuration of the ripple paths of the anode channels with respect to the ripple paths of the cathode channels located on opposite faces and belonging to the same bipolar conductive plate.
• FIGS. 6A-6B illustrate an anti-phase configuration of the anode channels of a bipolar conductive plate with respect to the cathode channels of another bipolar conductive plate, these two conductive plates being arranged on either side of the same AME structure;
• FIGS. 2A, 2B respectively have a first external face 20A and a second external face 20B, opposite to the first face 20A of a bipolar conductive plate 20 as implemented according to an embodiment of FIG. present invention.
• This plate 20 based on an electrically conductive material and preferably capable of resisting corrosion, may be a metallic material such as a stainless steel, for example 316L of the AISI standard corresponding to the reference Z2CND17. -12 of the Afnor NF A 35573.
• the plate 20 has on its first outer face 20A splines forming fluid channels 31 and on its second outer face 20B splines forming fluid channels 41.
• the bipolar conductive plate 20 is adapted to be integrated in a fuel cell formed of a stack of electrochemical cells typically comprising a plurality of superimposed bipolar plates of the same type.
• a stack of, for example, 230 cells 229 bipolar conductive plates such as that to be described, and 2 end-conductive plates on either side of the stack may be provided.
• 69 bipolar conductive plates such as the one to be described, and 2 end-conductive plates on either side of the stack, may be provided.
• the bipolar conductive plate 20 may be made in one piece or, as in the example illustrated in FIGS. 2A, 2B, be the result of an assembly of several parts such as sheets 30, 40 arranged against one another. other and assemblies.
• the first face 20A of the plate 20 ( Figure 2A) comprises in particular a first network of channels 31 of fluid circulation arranged in parallel.
• the channels 31 are here anode channels in which hydrogen is intended to circulate.
• the grooves and other hollow patterns formed in the plate 20, here in the sheet 30, can be made by various techniques such as molding or stamping or stamping or machining. For example, a water jet machining technique can be implemented to define the flutes.
• the juxtaposed channels 31 each extend along an axis which is parallel to a longitudinal axis Y of the plate 20, ie along an axis parallel to the longer side
• the fluidic channels 31 each have a path in the form of a succession of corrugations, in other words forming a sequence of curved regions that can advantageously be distributed periodically on either side of a given axis. parallel to the longitudinal axis Y, realizing a succession of vertices 31a and 31b hollow.
• the channels 31 of the first fluidic network are preferably arranged in phase relative to each other, so that the vertices 31a and corrugation hollows 31b of a channel 4 coincide in the same plane orthogonal to the plate 20 with respectively the peaks 31a and trough 31b of the other channels.
• the corrugated shape of the channels 31 makes it possible to promote the evacuation of the water produced in an electrochemical cell and to avoid a phenomenon of stratification which can create a blockage of reactants in the channels or a saturation of water at the level of diffusion layers.
• a membrane-electrode assembly structure capable of being contiguous to the bipolar plate.
• the shape of the channels 31 via an undulating pathway guiding the flow of the reactants makes it possible, by using centrifugal force, to avoid stagnation and the formation of liquid plugs and thus to promote the gas flow.
• a pitch of the patterns forming the undulations and an amplitude of these patterns are sufficiently small and a radius of curvature sufficiently high that the channels 31 comprise essentially slight undulations, that is to say having a shape close to that of straight channels.
• a range of curvature radius of the corrugations making it possible to maximize a contact between the first face 20A of the bipolar plate 20 and an assembly AME while maximizing the electrical performance of a cell provided with this assembly AME, is for example chosen between 20 mm and 50 mm.
• the channels 31 may also include localized portions 33 of narrowed cross-sections.
• the shrinkage depends on the desired level of pressure drop in order to allow the water droplets to escape.
• a pressure drop of the order of several tens of mbar, for example of the order of 20 mbar loss of load can be provided.
• the channels 31 are thus provided with zones with a given cross section and comprise localized portions 33 of smaller cross section than the given cross section.
• the narrowing may be provided so as to have a cross section at least divided by 2.
• the narrowed portions 33 of a channel 31 in this case have a cross section at least 2 times smaller than that of the rest of the channel.
• the portions 33 of restricted section within a fluidic channel 31 make it possible locally to create accelerations of the gas conveyed by this channel and thus to obtain an increase in the pressure drop of the channel 31 so as to better evacuate the water droplets. .
• the narrowed portions 33 of a channel 31 are preferably distributed periodically throughout an active surface in which this channel 31 extends.
• the narrowed portions 33 may be disposed at the level of hollows 31b and / or vertices 31a of the corrugations.
• the corrugated shape of the channels 31 combined with the presence of portions 33 of narrowed section prevent water clogging phenomena of the cells and thus increase the life of the battery. This particular configuration makes it possible to obtain better management of the quantity of water within an electrochemical cell and thus to improve its performance.
• the bipolar plate 20 can be made by assembling several plates 30, 40.
• the first network of fluidic channels 31 is in this case formed on a front face 30A of a first sheet 30 corresponding to the first outer face 20A of the plate 20, while the second network of fluidic channels 41 is formed on a front face 40A of a second sheet 40 corresponding to the second outer face 20B of the plate 20.
• the first sheet 30 and the second 40 are thus assembled at their rear faces 30B, 40B, respectively opposed to their front faces 30A, 40A.
• the channels or grooves defined on the front face 30A of the first sheet 30 form on the rear face 30B of this sheet 30, bumpy areas 131. These bumpy areas 131 are supported, in several points as can be seen in the cross-sectional view of FIG. 4A, on other dented zones 141 formed on the face rear 40B of the second sheet 40, and respectively corresponding to the channels or grooves defined on the front face 40A of the second sheet 40.
• the bipolar plate 20 between the rear faces 30B, 40B of the plates 30, 40 spaces 150 are however formed as can be seen in the cross-sectional view of Figure 4A to allow delimiting passages for a fluid, in particular a coolant, also called coolant between the plates 30, 40.
• the heat transfer liquid may be water.
• the inlet and the outlet of heat-transfer liquid are produced by means of openings 28 arranged at a large side of the plate 20.
• the plate bipolar 20, of appearance which may be substantially rectangular, also has on each small side of the rectangle an opening 24 for entry or exit of air, while on opposite corners of the plate 20 are openings 26 input or hydrogen output. These openings 26 are generally smaller in size than the air inlet / outlet openings 24.
• the second face 20B of the bipolar conductive plate 20 also comprises splines forming this time cathode channels in which air or oxygen is intended to circulate.
• a second network of juxtaposed parallel circulation channels 41 arranged in parallel is thus formed on the second face 20B of the bipolar plate 20.
• the channels 41 may have dimensions similar to that of the channels 31 of the first face. Typically, a larger number of cathode channels 41 is provided than the number of anode channels 31.
• the channels 41 each extend along an axis parallel to the longitudinal axis Ag and are also each in the form of a succession of undulations, in other words a succession of curved regions.
• the channels 41 of the second network produce undulations in a succession of curved regions forming vertices 41a and hollows 41b on either side of an axis parallel to the longitudinal axis Ag of the plate 20.
• the channels 41 of the second fluidic network are advantageously arranged in phase relative to each other.
• the ripples of the channels 41 of the second network may have a shape similar to those of the channels of the first network and possibly have a amplitude and a frequency equal to the amplitude and frequency of the ripples of the first grating, respectively.
• the channels 41 of the second network also preferably include localized portions of narrowed cross-sections. These localized portions are advantageously distributed periodically along the path of the channels 41. Typically, as on the first network of channels, it is possible to provide the narrowed portions of the second network 41 disposed at the hollows 41b and / or vertices 41a of the corrugations. .
• main plane of the plate 20 is meant a parallel plane passing through the plate 20 and parallel to the [O; x; y] plane of the orthogonal reference [O; x; y; z] given in FIG. 5.
• This phase-shifting arrangement of the channels 31 of the first network with respect to the channels 41 of the second network makes it possible, especially when this plate 20 is in the form of an assembly of sheets 30, 40, to be able to ensure the passage of fluid coolant between the sheets 30, 40 while maintaining sufficient areas of support between the plates 30, 40 to ensure a good mechanical rigidity of the sheet assembly.
• the arrangement of the channel networks on the two opposite faces 20A and 20B may advantageously be with inverted radii of curvature between the path of the channels 31 on the first face and the path of the channels 41 on the second face.
• said "in opposition of phase” one or more vertices 31a respectively of one or more channels 31 of the first network located on the first face 20A of the plate 20 are in the same plane orthogonal to the plate 20 as one or more hollows 41b respectively of one or more channels 41 of the second network located on a second face 20B of the plate 20.
• a phase-shifted or even phase-locked configuration of the first array and the second array is useful in particular in a structure as illustrated in FIGS. 6A and 6B with at least two bipolar plates 20.1, 20.2 of the same type as that described above, and arranged on either side of a membrane electrode assembly structure (AME).
• AME membrane electrode assembly structure
• the AME structure is conventionally composed of an electrolyte layer 113 conventionally formed of a membrane such as a solid polymer membrane impervious to gases and adapted to conduct the protons from the anode to the cathode while preventing a passage of electrons from one to the other of the electrodes.
• a membrane such as a solid polymer membrane impervious to gases and adapted to conduct the protons from the anode to the cathode while preventing a passage of electrons from one to the other of the electrodes.
• the AME structure may also be provided with diffusion layers whose function is to provide the supply of reactive gas for active layers of electrodes and to provide electrical conduction between a bipolar conductive plate and an active electrode layer.
• the electrodes of the AME structure are an anode 111 against which the first channel network 31 is disposed and a cathode 112 against which the second channel network 41, in phase shift or even in phase opposition with respect to the first network, is placed .
• the arrangement is such that the channels 31 of a first bipolar plate 20.1 arranged against one face of a structure AME form corrugations with radii of inverted curvature or in opposition of phase with respect to the ripples respectively of one or more channels 41 a second plate 20.2 disposed against another face of the same structure AME and opposite to the face against which the first plate is disposed.
• phase shift or offset between the two networks is taken with respect to a plane orthogonal to the main plane of the plate.

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• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Fuel Cell (AREA)

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• 2018
  • 2018-03-27 FR FR1852655A patent/FR3079676B1/fr active Active
• 2019
  • 2019-03-26 JP JP2021501101A patent/JP7334232B2/ja active Active
  • 2019-03-26 EP EP19719347.7A patent/EP3776705A1/de active Pending
  • 2019-03-26 WO PCT/FR2019/050683 patent/WO2019186051A1/fr not_active Ceased
  • 2019-03-26 US US17/041,590 patent/US11811104B2/en active Active
  • 2019-03-26 CN CN201980035609.3A patent/CN112236889A/zh active Pending
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