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
  • H01M8/0297—Arrangements for joining electrodes, reservoir layers, heat exchange units or bipolar separators to each other
• • 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
  • H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
  • H01M8/241—Grouping of fuel cells, e.g. stacking of fuel cells with solid or matrix-supported electrolytes
• • 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
  • H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
  • H01M8/2465—Details of groupings of fuel cells
• • 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
• • 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
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

• Fuel cell, cell or group of cells belonging to a. such cell, replacement kit for this cell and its manufacturing process The present invention relates to the technical field of energy production based on fuel cells and more particularly to fuel cell architectures.
• a fuel cell comprises a succession of elementary cells, arranged one next to the other in an assembly commonly called a "pack".
• Each cell has an anode compartment, where hydrogen oxidation occurs, as well as a cathode compartment, in which the oxygen in the air is reduced, with production of water.
• a proton exchange membrane PEM
• the anode compartment is placed in communication with a hydrogen inlet line, as well as a line for discharging the hydrogen consumed. The latter is mixed with a fraction of water, which has been produced at the cathode and has passed through the aforementioned separation membrane.
• the cathode compartment is provided with an inlet pipe for a mixture of oxygen-containing gases, typically air, as well as with a pipe for discharging this mixed oxygen-depleted mixture. to water.
• a mixture of oxygen-containing gases typically air
• a pipe for discharging this mixed oxygen-depleted mixture. to water.
• bipolar plates are generally provided, each of which separates two adjacent elementary cells. Such plates are capable of performing several functions, such as in particular the distribution of reactive gases.
• the fuel cell architecture of the type described above has certain drawbacks, in particular in terms of maintenance.
• the present invention aims to remedy such drawbacks, and proposes to produce a fuel cell of simple configuration, robust and whose maintenance is greatly facilitated.
• the invention provides a fuel cell, more particularly comprising a succession of elementary cells pressed against each other by compression means, each of these cells comprising a central structure formed by a membrane and two electrodes arranged on either side of this membrane, and on either side of the central structure, an external separation structure, the cells being pressed with their separation structures in contact with each other, so that these two adjacent cells can be separated from one another by deactivating the compression means, and means for supplying and discharging fluids extending along the cells and individually connectable to the latter.
• the supply and evacuation means each comprise - an expandable fluid distribution assembly, typically telescopic.
• each connecting member is mounted in a support of the fuel cell, with the possibility of transverse movement relative to this support, at least in the longitudinal direction of the fuel cell; at least one member is provided for sealing between each junction member and a corresponding channel and bearing against a sealing zone bordering this channel, said sealing zone being cylindrical, with an axis parallel to a main plane of the cell;
• the or each fluid distribution assembly comprises at least two fluid distribution elements, arranged one behind the other in the direction of flow of each fluid, these elements being connected to each other by at least one intermediate connector, capable of sliding in relation to the distribution elements that it connects;
• the or each fluid distribution assembly is made of an electrically insulating material and is advantageously made of a moldable material;
• the invention also relates to an elementary cell, or a group of elementary cells, for a fuel cell as defined above, the or each cell comprising at least one central structure formed by a membrane and two electrodes, arranged on either side of this membrane, as well as two separation members, provided at the two ends of the elementary cell or of the group of cells, each separation member being. able to bear against another separation member belonging to an adjacent cell, in an arrangement thus making it possible to easily separate the elementary cell or the group of cells from each adjacent cell without deconstructing the entire stack.
• the subject of the invention is also • a replacement kit for an elementary cell or a group of elementary cells as defined above, comprising a central structure formed by a membrane and two electrodes, arranged on either side of this membrane, as well as an enclosed package in which the central structure is received.
• orifices are provided in a peripheral joint of the central structure, these orifices being able to receive the positioning means; - the packaging contains a neutral gas, in particular nitrogen.
• the invention finally relates to a process for manufacturing the replacement kit as defined above, in which the central structure is assembled by hot pressing, then the packaging is brought around this central structure.
• an electrical preconditioning current is passed through the central structure.
• - Figure 10 is a longitudinal sectional view illustrating a gas distribution assembly belonging to the fuel cell of Figures 1 to 4;
• - Figure 11 is a longitudinal sectional view, on a larger scale, illustrating a connecting finger belonging to the fuel cell of Figures 1 to 4;
• FIG. 12 is a schematic view illustrating a group of elementary cells that can equip the fuel cell of Figures 1 to 4.
• FIG. 13 is a schematic perspective view, illustrating a replacement kit able to cooperate with an elementary cell, or a group of elementary cells for equipping the fuel cell of FIGS. 1 to 4.
• the fuel cell of the invention comprises a base or support structure 2, typically in the form of a plate, above which extends, parallel to the base, an intermediate plate or plate 4. Between these two elements are inserted between two gas distribution assemblies or manifolds, identified by the references 6 and 7, which will be described in more detail below.
• the plate 4 is surmounted by two parallel vertical side walls 8, at the front end of which are arranged two vertical insulating pieces parallel 10 orthogonal to the walls 8.
• Conductive sheets 12, for example made of copper and connected to electrical terminals 14, are placed on the inside of the insulating pieces 10.
• a succession of elementary cells 16 ⁇ to 16 n is interposed between the two conductive sheets 12. The structure of each of these cells will be described in more detail in the following.
• Two vertical holding plates 18 ⁇ and 18 2 intended for the mechanical holding of all the elementary cells, are arranged against the external face of the insulating pieces 10. Furthermore, four bars or tie rods 20 extend horizontally along the side walls 8, outside of these.
• each bar 20 passes through the first holding plate 18 ⁇ . It is joined there by means of a stop formed by a head 22, while a Belleville washer 220, not shown in detail, is interposed between this stop 22 and the opposite face of the plate 18.
• these washers 220 make it possible to absorb variations in length, due to possible thermal expansion, and guarantee that the assembly pressure is maintained.
• the bars 20 pass through the other retaining plate 18 2 and engage in a vertical auxiliary plate 24, provided at a distance, outside the retaining plate 18 2 , parallel to the latter.
• the bars 20 are provided with a threaded portion, cooperating with a terminal assembly nut 26.
• a cylinder 28, advantageously hydraulic, provided with its supply piping 30, is interposed between the holding plate 18 and the auxiliary plate 24. It should be noted that, in the vicinity of the holding plate 18, each bar 20 is advantageously provided with an intermediate threaded portion, capable of cooperating with a nut 32 for maintaining the tension cooperating in abutment against the external face of the plate 18.
• the auxiliary plate 24 receives four axial screws, of which only two 34 are shown. The end of the rods of these screws is able to bear against the external face of the retaining plate 18 2 , so that these screws are, if necessary, able to replace the jack 28.
• each elementary cell 16 comprises a central lamellar structure 36, consisting of a sandwich of an electrode, a membrane and an electrode.
• This structure is bordered peripherally by a seal 37, shown in Figure 13.
• Each electrode can be structured to directly distribute the gases. It can also, as a variant, comprise a reaction zone, associated with a diffusion zone.
• the membrane is advantageously made of Nafion TM polymer, sold by Du Pont, the electrodes being made of a porous structure of platinum-coated graphite, Nafion TM and PTFE, and the interstitial diffusion layers of graphite and PTFE.
• two intermediate plates 38 and 40 are arranged on either side of the central structure 36.
• the intermediate plate 38 is intended for the circulation of hydrogen
• the plate 40 is intended for the circulation of air.
• These plates 38, 40 are for example made of graphite, or a porous metallic material.
• two separation plates 42 and 44 are placed on either side of the plates 38 and 40.
• These end plates 42 and 44 which are assigned to the respective distributions of hydrogen and air, are placed in communication with a neighboring intermediate plate, as will be described below. They are made, for example, of graphite, a graphite-polymer mixture or of metal.
• each plate 42 or 44 can be produced in one piece with a corresponding intermediate plate 38 or 40, so as to form a single separation member.
• the overall thickness of the cell can be reduced to around 6 mm.
• a loop or loop 46 is also provided, fixed at its ends to the upper edges of the two plates separation 42 and 44 of the same elementary cell 16.
• Such a handle allows the gripping and handling of this elementary cell by a user, which gives a particularly easy character to the disassembly of this cell.
• the opposite faces of the adjacent partition plates 42, 44 are notched or grooved, which leads to the formation of fins or ribs 47.
• the spaces between the latter are able to circulate a cooling air flow, coming from fans 48 advantageously arranged between the plates 4 and .2, directly in contact with these separation plates. Under these conditions, the heat exchange surface is integrated into the elementary cells of the fuel cell.
• the pitch and the width of the fins are calculated so as to prevent facing fins from overlapping each other, during assembly or disassembly.
• the heat exchange function, described above, can also be provided by another member, such as a corrugated metal sheet, a grid, or even a porous metallic material.
• each intermediate plate 38, 40 is provided with a corresponding pin 49, 50.
• the latter typically passes through the peripheral joint of the central structure 36, so as to be housed in an orifice 52 , 54, arranged opposite in the other intermediate plate 40,38.
• These pins 49.50 ensure not only a polarization, for the mounting of the cell, but also a maintenance and a positioning of the whole of the pre-assembled cell, in the absence of other fixing means.
• all the elementary cells of the fuel cell may not be individual, in this sense a subset of these cells can form an inseparable group, assigned the reference 116 in FIG. 12.
• a group 116 of cells is provided with one or more bipolar separation plates, made of in a manner known per se.
• there are three cells 116 ⁇ to 116 3 separated in pairs by two bipolar plates 117.
• this group of cells 116 is removable as a whole with respect to the cells which are adjacent to it, not shown in this figure 12.
• FIG. 10 illustrates one (6) of the above-mentioned gas distribution assemblies, it being understood that the other (7) of these assemblies, sketched in FIG. 1, has a similar structure.
• the assembly 6 consists of three aligned distribution elements 6 ⁇ to 6 3 , each hollowed out with an axial through hole 55, these holes communicating with each other. These elements are also connected two by two by annular intermediate connectors 56 inserted in end zones of enlarged diameter of the holes 55.
• Each connector which is provided with two peripheral "0-ring" seals, is suitable for slide in relation to the two elements it connects. It thus ensures a fixation TELESC 'opique between the two. This therefore makes it possible to absorb the variations in length of the stack due to pressurization, with a view to its assembly, or else to thermal dilations in operation.
• One (6 ⁇ ) of the distribution elements is also provided, at its outer end, with a connector 58, intended to be connected to an air inlet.
• This connector 58 provided with a peripheral seal, and received in one end of enlarged diameter of the bore 55 of the element 6 ⁇ , is also capable of sliding relative to this element 6 ⁇ .
• the other end element 6 3 is equipped with a plug 60, intended to prevent any untimely exit of air.
• at least one of the distribution assemblies 6, 7 is made of an electrically insulating material, for example polyamide or polypropylene.
• each fluid distribution assembly is made of a moldable material, which makes it possible to set up mass production, and therefore to reduce the corresponding costs.
• FIG. 3 illustrates the separation plate 44 2 , dedicated to air circulation.
• the bore 55 intended for the air intake, communicates with a horizontal transverse passage 68 ⁇ , which itself opens into a vertical interior volume receiving a junction finger 70 ⁇ vertically passing through the plate 4 with a possibility of transverse movement, at least from rear to front of the stack (arrow f in FIG. 2).
• this clearance makes it possible to compensate for the variations in length of the stack, when it is pressurized.
• the finger 70 ⁇ comprises a tubular body 72, terminated by a chamfered lower end 74, provided with a peripheral seal 76, received in the vertical volume of the block of 1 distribution assembly 6.
• the body 72 is further provided with a collar 78, adapted to cooperate with the underside of the plate 4, so as to retain the assembly of the finger in position, against one upward effort.
• this finger 70 ⁇ has a chamfered upper end 80, provided with a peripheral seal 82, inserted, in use, in the walls of an internal distribution channel 84, extending vertically in the separation plate 44 2 .
• the peripheral seal 82 bears against a sealing zone 85, bordering the channel 84.
• This sealing zone 85 has a cylindrical shape, the cross section of which, circular in the example shown, can be arbitrary. Furthermore, the main axis of the cylinder forming the zone 85 is parallel to the main plane of the cell, that is to say that it is vertical in FIG. 11. It should be noted that the two ends 74 and 80 of the finger 70 ⁇ also allow it to absorb variations in the length of the stack while guaranteeing tightness thanks to the two O-rings 76, 82. As an alternative, the two ends of the joining finger 70 can be made of a material allowing such a clearance. Mention will be made in particular, without limitation, of an elastomeric material.
• the channel 84 opens, via a connector 86, into a first end 88 of an air distribution network, formed in a conventional manner in the intermediate plate 40 forming a current collector.
• This network extends in the vicinity of the central structure 36, in order to allow the implementation of the oxygen reduction reaction of the air, in the cathode compartment of the cell.
• this air distribution network ends, in the intermediate plate 40, by another end 90 which opens, via a tubular connection 92, into an air evacuation channel 94, formed in the lower end of the separation plate 44.
• the walls of this channel 94 receive another junction pin 70 2 , similar to that 70 ⁇ described above.
• This finger 70 2 connects the channel 94 to an additional horizontal transverse passage 68 2 which opens into the axial bore 62 of the air outlet, formed in the gas distribution assembly 7.
• the hydrogen inlet hole 64 is placed in communication with a vertical transverse passage 69 ⁇ which opens into the interior volume of a connecting finger 70 3 , similar to those 70 ⁇ and 70 2 described previously.
• the downstream end, namely upper end in FIG. 4, of this finger 70 3 opens into a vertical channel 96, formed in the plate 42 2 , belonging to the same elementary cell 16 3 as the plate 44 2 .
• this channel 96 is put in communication, via a tubular connection 98, with one end 100 of a hydrogen distribution network analogous, in its architecture, to the air distribution network described above. above.
• This hydrogen network which is formed in the intermediate plate 38, extends opposite, with respect to the central structure 36, of the air distribution network, described above.
• Such a distribution network is intended for the implementation of the hydrogen oxidation reaction, in the anode compartment of the cell.
• this hydrogen distribution network is placed in communication, via a tubular connector 104, with a channel 106 for evacuating hydrogen, formed in the separation plate 44 2 (see also figure 4).
• the lower end of this channel 106 receives the upper end of a connecting finger 70, similar to those described above.
• This finger 70 4 thus communicates the channel 106 with a vertical passage 69 2 , formed in the distribution assembly 7 and then opens into the axial bore 66, allowing the exit of the hydrogen.
• FIG. 13 illustrates, according to one aspect of the invention, a replacement kit for an elementary cell 16 or group 116 of elementary cells.
• This kit includes a replacement central sandwich structure 36R, similar to that described above.
• This central structure 36R is provided, in known manner, with a flat peripheral seal 37 bordering the membrane and the electrodes.
• Two orifices 37 ′ are formed in this joint 37, for example symmetrically with respect to the barycenter of the whole of the structure. Such orifices are suitable for receiving the pins 49, 50 described with reference to FIGS. 6 and 7.
• the sandwich structure has a variable surface, typically in a format between 12 x 15 cm and an A 4 format.
• the replacement kit includes a package 36 ′, in which the structure 36R is received in a sealed manner.
• packaging is for example made of cellophane or polyurethane.
• the package contains a gas inert, such as nitrogen.
• the process for manufacturing the replacement kit in FIG. 13 firstly comprises an assembly phase of the central sandwich structure 36R. This is carried out by hot pressing, in a known manner, for example at a temperature between 80 and 90 ° C, as well as at a pressure close to 20 bars.
• a validation of this central structure is carried out by subjecting the latter to a conditioning current, the value of which is for example between 0.4 and 0.6 A / cm.
• a conditioning current the value of which is for example between 0.4 and 0.6 A / cm.

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Fuel Cell (AREA)

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• 2002
  • 2002-03-06 FR FR0202843A patent/FR2837024B1/fr not_active Expired - Fee Related
• 2003
  • 2003-03-03 WO PCT/FR2003/000672 patent/WO2003075390A2/fr not_active Ceased
  • 2003-03-03 US US10/506,648 patent/US20050158602A1/en not_active Abandoned
  • 2003-03-03 CA CA002474542A patent/CA2474542A1/fr not_active Abandoned
  • 2003-03-03 EP EP03727560A patent/EP1525640A2/de not_active Withdrawn
  • 2003-03-03 AU AU2003233353A patent/AU2003233353A1/en not_active Abandoned

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