Method for manufacturing an assembly of membranes coated with a catalyst, equipped on each of their faces with a sub-seal

Abstract

Method for manufacturing an assembly of catalyst-coated membranes equipped on each of their faces with a sub-seal. The invention relates to a method for manufacturing an assembly of catalyst-coated membranes (2) each face of which is equipped with a sub-seal comprising the steps: 1) a carrier film covered with a layer of adhesive is provided; 2) a layer of sub-seal material is deposited on the adhesive layer; 3) a pre-cut line (13) and a cut (23) are made so as to obtain a stack of material layers divided into two comprising a 1st and a 2nd portion of the stack (14a, 14b); 4) cuts are made to obtain central openings (5a, 5b); 5) a CTM (2) is deposited on each central opening (5a); 6) Fold the second stacking section (14b) over the first stacking section (14a); 7) Heat seal; 8) Cut. See Figure 4a for abbreviations.

Description

Title of the invention: Method for manufacturing an assembly of membranes coated with a catalyst, equipped on each of their faces with a sub-seal

[0001] The present invention relates to a method for manufacturing a set of membranes coated with a catalyst which are equipped on each of their faces with a sub-seal.

[0002] Proton exchange membrane fuel cells, hereinafter abbreviated by the English acronym "PEMFC" for "Polymer Electrolyte Membrane Fuel Cells," are a type of fuel cell developed to generate electricity in a wide variety of applications such as automotive, aviation, and telecommunications. Their characteristics include low-pressure and low-temperature operation, as well as the use of a specific polymer electrolyte membrane, forming the ion-exchange membrane. A PEMFC transforms the chemical energy released during the electrochemical reaction of dihydrogen and dioxygen into electrical energy.

[0003] A unit cell consists of a membrane electrode assembly, hereinafter abbreviated by the English acronym "MEA" for "Membrane Electrode Assembly," arranged between two bipolar anode and cathode plates. Although the amount of electrical energy generated by a single unit cell is small, the combination of several unit cells in a PEMFC generates enough electrical power to propel a car or an airplane. Therefore, depending on the intended application, a PEMFC generally comprises several hundred unit cells connected in series.

[0004] The MEA is the central and crucial element of a PEMFC. Indeed, the chemical conversion takes place in this assembly. The production of high-quality MEA is therefore essential in the manufacture of PEMFCs.

[0005] As shown schematically in Figure 1, in perspective and exploded view, an MEA 1 comprises: - a membrane coated with a catalyst 2, hereinafter abbreviated according to the English acronym "CCM" for "Catalyst Coated Membrane"; - 2 sub-gaskets (also known by the English term "subgasket") 3a,3b which are arranged on either side of the CCM 2; - 2 gas diffusion layers 4a,4b, hereinafter referred to by the English acronym "GDL" for "Gas diffusion layer" which are arranged on the face of the sub-joints 3a,3b which is opposite to the face of the sub-joint in contact with the CCM 2.

[0006] The MEA 1 has the function of directing the passage of gases (dihydrogen, air, water vapor) and maximizing the catalytic redox reaction of dihydrogen and dioxygen allowing the generation of electricity, water and steam.

[0007] The CCM 2 is arranged centrally within the MEA 1.

[0008] The sub-seals 3a,3b can be made of poly(ethylene naphthalate), also known by the abbreviation "PEN". The sub-seals 3a,3b each comprise: - a central opening 5a,5b, for example rectangular in shape, the surface area of ​​which is smaller than the surface area of ​​the CCM, to allow gases to access the CCM 2; - a plurality of lateral openings 6a,6b, of various geometric shapes, for example triangular, which are arranged around the central openings 5a,5b respectively; these lateral openings 6a,6b are configured for the supply and evacuation of gases at the level of the CCM 2.

[0009] Because the sub-joints 3a,3b have such openings 5a,5b,6a,6b, they are not very rigid and difficult to handle.

[0010] The manufacture of a MEA is complex because it requires placing very precisely (namely with an accuracy of plus or minus 0.3 mm to 0.5 mm) the different layers of materials detailed above, namely the CCM 2, the 2 sub-seals 3a,3b and the 2 GDL 4a,4b.

[0011] Currently, these different layers of material can be precisely placed using a robot guided by a vision system (also known as a "pick and place" system). The guided robot has the disadvantage of being relatively slow in its movements, and within a limited range. Furthermore, in order to increase the production rate of MEAs, it is necessary to invest in a growing number of robots; this increases the production costs of MEAs and therefore of PEMFCs.

[0012] Furthermore, as mentioned above, due to the openings 5a, 5b, 6a, 6b, the sub-seals 3a, 3b being not very rigid are difficult to handle; which makes the piece-by-piece assembly using a robot even more difficult.

[0013] In view of these drawbacks related to the use of guided robots to assemble the different layers of materials of the MEA, the inventors of the present invention sought to simplify the manufacturing process of the MEA by eliminating such guided robots for the essential steps of the assembly of the sub-seals on the CCM in order to avoid a "piece by piece" assembly of all the parts, and this by proposing a manufacturing process of a set of CCMs equipped on each of their faces with a sub-seal, most of the steps of which constitute a continuous "roll by roll" manufacturing process and are not carried out using guided robots.

[0014] In the context of the present invention, the continuous manufacturing process "roll to roll" means a continuous manufacturing process in which the starting product is a set of materials in the form of a roll and the final product is a set of other materials also in the form of a roll.

[0015] The invention thus relates to a method for manufacturing an assembly of CTMs, each face of which is equipped with a sub-seal (hereinafter abbreviated as "method for manufacturing CTMs with sub-seals"), said manufacturing method comprising at least the following steps: 1) we have a carrier film extending along a longitudinal direction, one of whose two faces is covered with a layer of adhesive; 2) a layer of under-joint material is deposited on the adhesive layer of the carrier film, the face of the under-joint material layer that is opposite to that which is in contact with said adhesive layer is covered with a layer of thermoactivatable adhesive so as to obtain a stack of material layers, extending along the longitudinal direction of said carrier film; 3) We perform: - a dashed pre-cut line, extending along the longitudinal direction of said stack of material layers obtained at the end of step 2), in the middle of said stack, said dashed pre-cut line being made over all or part of the thickness of the assembly formed by the superposition of the thermoactivatable adhesive layer and the under-joint material layer and - a cut through the entire thickness of the assembly formed by the superposition of the carrier film and the adhesive layer which extends in a direction parallel to the axis of the pre-cut line in dotted lines, so as to obtain a stack of material layers divided into two which includes a first portion of stack and a second portion of stack; 4) cuts are made in the assembly formed by the superposition of the layer of under-joint material and the layer of thermoactivatable adhesive at the level of the 1st and 2nd stacking portions so as to obtain a stack of material layers divided into two and cut which includes in the 1st and 2nd stacking portions central openings whose dimensions correspond to central openings of under-joints of a MEA, said central openings of the 1st stacking portion being symmetrical to the central openings of the 2nd stacking portion with respect to the axis of said pre-cutting line in dotted line; 5) a CCM is placed, in a centered manner, on each central opening of the first portion of the stack, said CCM having a surface area greater than said central opening so as to cover it entirely and to obtain a stack of material layers divided into two and cut which includes a set of CCMs; 6) the 2nd stacking portion is folded over the 1st stacking portion along the axis of the dotted pre-cut line, optionally by performing a hot pre-sealing of the 2nd stacking portion onto the 1st stacking portion, so as to obtain a stack of material layers folded in half and optionally pre-sealed; 7) a hot sealing is performed on the stack of layers of material folded in half and optionally pre-sealed obtained at the end of step 6) so as to obtain a stack of layers of material folded in half and sealed; 8) Cuts are made in the stack of layers of material folded in half and sealed obtained at the end of step 7) so as to obtain a set of CCMs equipped on each of their faces with a sub-seal; further cuts are made to obtain lateral openings whose arrangement relative to the central openings and dimensions correspond to the lateral openings of MEA sub-seals; said additional cuts are made: - during step 4) in the assembly formed by the superposition of the under-joint material layer and the thermo-activatable adhesive layer at the level of the 1st and 2nd stacking portions, said lateral openings of the 1st stacking portion being symmetrical to the lateral openings of the 2nd stacking portion with respect to the axis of said dashed pre-cut line Or - at the end of step 7) in the stack of layers of material folded in half and sealed, The carrier film and the adhesive layer can be removed at any time from the end of step 6).

[0016] The CCM manufacturing process with sub-seals according to the invention has the advantages of being implemented easily and quickly.

[0017] Step 3) of making, on the one hand, the pre-cutting line in dotted lines made on all or part of the thickness of the assembly formed by the superposition of the heat-activated adhesive layer and the under-seal material layer, and on the other hand, the cut through the entire thickness of the assembly formed by the superposition of the carrier film and the adhesive layer, thus dividing the stack of material layers in two so as to obtain a first and a second Stacking sections, combined with the creation in step 4) of central openings (and optionally lateral openings) in the first and second stacking sections, perfectly symmetrical with respect to the axis of the dashed pre-cut line, ensures extremely reliable and precise folding in step 6) of said second stacking section onto said first stacking section. This allows for the very easy and rapid production of a set of MCCs equipped on each of their faces with a sub-joint, said sub-joint being positioned perfectly centered with respect to the MCC. This is essential for the subsequent manufacturing of the MEA, namely the addition of the two GDL layers to each of the two sub-joints, as shown in the detailed [Fig. 1] above.

[0018] Also, the use of a carrier film during the manufacturing process of TMCs with sub-seals according to the invention makes it possible to stiffen the stack of material layers. This offers the following advantages: - easily and reliably create the dotted pre-cut line, as well as the central and lateral openings; - to facilitate the folding of the 2nd stacking portion onto the 1st stacking portion in an extremely precise manner.

[0019] At the end of step 2) of the CTM manufacturing process with sub-seals according to the invention, the stacking of material layers, extending along the longitudinal direction of said carrier film, thus comprises the superposition of the following material layers: - the film in question, - the adhesive layer, - the layer of under-joint material, - the layer of thermoactivatable adhesive.

[0020] The carrier film material may have a Young's modulus in tension, measured according to ASTM D638, between 1 GPa and 100 GPa, preferably between 2 GPa and 50 GPa.

[0021] The material of the carrier film can be chosen from the group consisting of polyethylene terephthalate (hereinafter abbreviated "PET") and polypropylene.

[0022] The thickness of the carrier film can be between 12 pm and 350 pm, preferably between 23 pm and 250 pm, more preferably between 36 pm and 150 pm.

[0023] The carrier film is advantageously in the form of a roll. The width of the roll can be between 200 mm and 800 mm, preferably between 300 mm and 700 mm, and even more preferably between 400 mm and 600 mm. The length of the roll can be greater than 20 m, preferably greater than 100 m. It is perfectly within the capabilities of a person skilled in the art to determine a length of a roll of carrier film that is technically feasible and suitable for implementing the CTM manufacturing process with sub-seals according to the invention. For example, by way of illustration, the length of the carrier film roll can be between 50 m and 500 m.

[0024] One side of the carrier film is coated with a layer of adhesive. The adhesive is chosen appropriately so that: - the carrier film can be easily removed at any time during the manufacturing process according to the invention from the end of step 6), i.e. before or after step 7) of hot sealing or after step 8) of cutting; - the carrier film exhibits low adhesion to the under-joint material layer and the CCMs so as to facilitate the implementation of the CCM manufacturing process with under-joints according to the invention and not to damage said CCMs.

[0025] The choice of the material for the adhesive layer is perfectly within the capabilities of a person skilled in the art.

[0026] The adhesive layer material can be an adhesive material: - with low adhesion or - with high adhesion.

[0027] By "low adhesion adhesive material", we mean an adhesion force in 90° peel of the adhesive on the back of the under-joint material layer that may be less than 2 N / cm.

[0028] By "high adhesion adhesive material", we mean an adhesion force in 90° peel of the adhesive on the back of the under-joint material layer that can be greater than 2 N / cm.

[0029] When the adhesive layer material is a high-adhesion adhesive material, it may be an acrylic-based pressure-sensitive adhesive, also known by the English name "Pressure Sensitive Adhesive". More specifically, said material may be a pressure-sensitive adhesive based on polyurethane, silicone, natural rubber, ethylene-vinyl acetate copolymer, or poly(styrene-isoprene-styrene) block copolymers.

[0030] This may, for example, be an acrylic-based pressure-sensitive adhesive marketed by the company ASHLAND under the trade names AROSET 1920-Z-52 or AROSET 1910-TH-52.

[0031] When the adhesive layer material is a low adhesion adhesive material, it may be a pressure-sensitive adhesive based on acrylic, polyurethane, silicone, natural rubber, ethylene-vinyl acetate copolymer or poly(styrene-isoprene-styrene) type block copolymers.

[0032] The low adhesion adhesive material and the high adhesion adhesive material can thus be pressure-sensitive adhesives whose formulations will differ from each other so as to obtain a more or less sticky adhesive material.

[0033] When the adhesive layer material is a low adhesion adhesive material, it may also be a low molecular weight (co)polymer (for example polyester, polyethylene and polyamide) having an immediate adhesion greater than 0.1 N / cm after 5 seconds of contact at room temperature or with heating below 170°C, preferably below 150°C, more preferably below 110°C.

[0034] When the adhesive layer material is a low adhesion adhesive material, it can also be a thermoactivatable adhesive based on a polymer or copolymer of polyester, polyethylene and polyamide.

[0035] In embodiments in which the adhesive layer material is a low adhesion adhesive material, the surface mass of said adhesive layer may be between 2 g / m2 and 100 g / m2, preferably between 5 g / m2 and 80 g / m2, more preferably between 10 g / m2 and 50 g / m2.

[0036] In embodiments in which the material of the adhesive layer is a high-adhesion adhesive material, the surface mass of said adhesive layer may be between 5 g / m2 and 150 g / m2, preferably between 10 g / m2 and 80 g / m2, more preferably between 15 g / m2 and 50 g / m2.

[0037] The adhesive layer can be distributed over the entire surface of the carrier film or partially.

[0038] In embodiments of the invention in which the adhesive layer material is a low adhesion adhesive material, the adhesive layer is advantageously distributed over the entire surface of the carrier film.

[0039] In embodiments of the invention in which the adhesive layer material is a high-adhesion adhesive material, the adhesive layer is advantageously distributed over a portion of the surface of the carrier film. The adhesive layer can be applied to certain areas of the carrier film surface, for example, by a screen-printing process. In another embodiment of the invention, an adhesive layer of a high-adhesion adhesive material is applied to the entire surface of the carrier film. Then, a film made of a polymer material (for example, PET) with a thickness between 5 and 50 µm (for example, 12 µm) is applied to a portion of the surface of said adhesive layer. The polymer material can be replaced by a varnish or a non-adhesive ink (for example, a non-adhesive ink applied by flexography). In this way, a portion of the layer Once the adhesive of the high-adhesion material is neutralized, the surface of the carrier film is then partially adhered by this layer of adhesive.

[0040] The under-seal material can be chosen from the group consisting of PEN, preferably heat-stabilized PET, polyphenylene sulfide (PPS) and polyimide.

[0041] The thickness of the under-joint material layer can be between 12 pm and 150 pm, preferably between 15 pm and 100 pm, more preferably between 20 pm and 50 pm.

[0042] In an advantageous embodiment of the invention, one face of the backing material layer is coated with a layer of anti-adhesive material (for example, silicone, fluorosilicone, a polyolefin such as polypropylene, or polyvinylcarbamate), with a thickness ranging from 0.1 µm to 20 µm, and this face is in contact with the adhesive layer. This anti-adhesive layer facilitates the removal of the backing film from the backing material layer.

[0043] The material of the heat-activated adhesive layer covering one face of the underseal material layer (namely, the face opposite the face in contact with the adhesive layer covering one face of the carrier film) can be selected from polyester, polyethylene, and polyamide polymers or copolymers. The selection of the material for the heat-activated adhesive layer is perfectly within the capabilities of a person skilled in the art.

[0044] The surface mass of said thermoactivatable adhesive layer can be between 5 g / m2 and 150 g / m2, preferably between 10 g / m2 and 80 g / m2, even more preferably between 15 g / m2 and 50 g / m2.

[0045] In step 3) of the CTM manufacturing process with sub-seals according to the invention, a pre-cut line is made in the middle of the stack obtained at the end of step 2). The pre-cut extends along the longitudinal direction of said stack. It is made over all or part of the thickness of the assembly formed by the superposition of the thermoactivatable adhesive layer and the sub-seal material layer.

[0046] In step 3) of the CTM manufacturing process with sub-seals according to the invention, the dotted pre-cut line can be made by means of a rotary cutting tool or a laser.

[0047] Advantageously, the pre-cutting line in dotted lines extends over at least 20% of the thickness of the assembly formed by the superposition of the thermoactivatable adhesive layer and the under-joint material layer.

[0048] When the dashed pre-cut line extends over the entire thickness of the assembly formed by the superposition of the heat-activated adhesive layer and the under-joint material layer, the ratio between the cut area of ​​said line of pre-cutting in dotted lines and the uncut area of ​​said pre-cutting line in dotted lines may advantageously be between 10% and 95%, preferably between 20% and 80%.

[0049] When the dashed pre-cut line extends over part of the thickness of the assembly formed by the superposition of the thermoactivatable adhesive layer and the under-joint material layer, the ratio between the cut area of ​​said dashed pre-cut line and the uncut area of ​​said dashed pre-cut line may advantageously be greater than 10%, preferably greater than 20%, even more preferably greater than 50%.

[0050] In step 3) of the manufacturing process for CTMs with sub-seals according to the invention, the cutting can remove a portion (in particular a minute portion) of material from the assembly formed by the superposition of the carrier film and the adhesive layer. In certain embodiments of the invention, as explained below, the removal of material from the assembly formed by the superposition of the carrier film and the adhesive layer may be zero. The cutting therefore extends along a direction parallel to the axis of the dashed pre-cut line.

[0051] The cut is made through the entire thickness of the assembly formed by the superposition of the carrier film and the adhesive layer.

[0052] The cutting can be carried out continuously along a direction parallel to the axis of the pre-cutting line in dotted lines.

[0053] In another embodiment of the invention, the cutting can be carried out discontinuously along a direction parallel to the axis of the pre-cutting line in dotted lines, preferably with a cutting rate of at least 50%, more preferably at least 70%, even more preferably at least 90%.

[0054] Preferably, the cutting is carried out continuously along a direction parallel to the axis of the dashed pre-cut line. This ensures that the folding of the second stacking portion onto the first stacking portion along the axis of the dashed pre-cut line is perfectly reliable and secure during step 6) of the manufacturing process for CTMs with sub-seals according to the invention.

[0055] The cutting can be carried out using a rotary cutting tool or a laser.

[0056] The width of the cut is preferably less than 10 cm, more preferably less than 2 cm, and even more preferably less than 1 mm. When the width of the cut is extremely small, for example less than 1 mm, the material shrinkage of the assembly formed by the superposition of the carrier film and the adhesive layer is therefore minimal, or even zero (in other words, non-existent).

[0057] The cutting of the assembly formed by the superposition of the carrier film and the adhesive layer and the pre-cutting line in dotted lines are configured so that the stack of material layers can be easily folded in half along the axis of said pre-cutting line in dotted lines during step 6) of the manufacturing process according to the invention.

[0058] In one embodiment of the invention, the width of the under-joint material layer is equal to the width of the carrier film.

[0059] In another embodiment of the invention, the width of the underseal material layer is greater than the width of the carrier film. The width of the underseal material layer can be between 0.1% and 20% greater than the width of the carrier film.

[0060] This embodiment of the invention, in which the width of the under-joint material layer is greater than the width of the carrier film, is advantageous. Indeed, in each of the first and second stacking portions, the assembly formed by the superposition of the under-joint material layer and the heat-activated adhesive layer will extend beyond the assembly formed by the superposition of the carrier film and the adhesive layer by a length that may be the same or different depending on the width of the cut chosen.During the optional pre-heat sealing of step 6) and during the heat sealing of step 7), those portions of the assembly formed by the overlapping layer of the underseal material and the heat-activated adhesive layer that extend beyond the assembly formed by the overlapping carrier film and the adhesive layer will be more easily and reliably sealed together; this has the advantage of helping to prevent the 1st and 2nd stacking portions from shifting away from each other when the carrier film is removed.

[0061] In step 4) of the manufacturing process according to the invention, the cuts can be made with a rotary cutting tool, a flat cutting tool, or a laser.

[0062] The removal of material from the assembly formed by the superposition of the underseal material layer and the thermo-activatable adhesive layer in step 4) so ​​as to obtain central openings (and optionally lateral openings) can be carried out using any technique readily available to a person skilled in the art. For example, the removal technique can be implemented with an adhesive carrier strip.

[0063] The central openings obtained at the end of step 4) can be rectangular in shape. The width of the central openings can be between 50 mm and 250 mm. The length of the central openings can be between 100 mm and 500 mm.

[0064] In the first and second stacking portions, the central openings may be in the form of one or more rows of a plurality of openings central, the said central rows of openings being all parallel to the axis of the dotted pre-cut line.

[0065] In one embodiment of the invention, the first stacking portion comprises a row of central openings and the second stacking portion comprises a row of central openings.

[0066] In one embodiment of the invention, the first stacking portion comprises between 2 and 5 rows of central openings and the second stacking portion comprises between 2 and 5 rows of central openings.

[0067] The spacing between two consecutive central openings may be the same throughout a row or it may vary within the same row.

[0068] The spacing between two consecutive central openings may be the same from one row to the next or it may differ from one row to the next.

[0069] In other words, the arrangement of the central openings on the 1st and 2nd stacking portions is free of choice and perfectly within the reach of a person skilled in the art.

[0070] The essential thing is that the set of central openings of the 1st portion of stacking is symmetrical to the set of central openings of the 2nd portion of stacking with respect to the axis of the pre-cutting line in dotted lines.

[0071] The side openings may have a triangular geometric shape. The choice of the number, arrangement in relation to the central openings and dimensions of the side openings is perfectly within the capabilities of a person skilled in the art.

[0072] Optionally, during any step of the manufacturing process according to the invention before the completion of step 6) of folding, one or two double-sided adhesive strip(s) extending in a direction parallel to the axis of the pre-cut line in dotted lines may be applied to the thermoactivatable adhesive layer of the 1st stacking portion or to the adhesive layer of the 2nd stacking portion.

[0073] The double-sided adhesive strip(s) are placed near the dotted pre-cut line and / or near the outer edge of the 1st stacking portion or the 2nd stacking portion presented by said 1st and 2nd stacking portions.

[0074] In one embodiment of the invention, a double-sided adhesive strip is applied near the dotted pre-cut line.

[0075] In the embodiment of the invention mentioned above, in which the width of the under-seal material layer is greater than the width of the carrier film, such that in each of the first and second stacking portions, the assembly formed by the superposition of the under-seal material layer and the thermo-activatable adhesive layer extends beyond the assembly formed by the superposition of the carrier film and the adhesive layer by a length that may be identical or Since the cutting width varies depending on the chosen width, it is advantageous to apply double-sided adhesive tape close to the dotted pre-cut line.

[0076] This double-sided adhesive tape allows the first stacking portion to be glued to the second stacking portion near the dotted pre-cut line during folding step 6. This also helps to prevent the first and second stacking portions from shifting apart when the carrier film is removed, thus reinforcing the advantage provided by the fact that in each of the first and second stacking portions, the assembly formed by the overlapping layer of underseal material and the heat-activated adhesive layer extends beyond the assembly formed by the overlapping carrier film and adhesive layer mentioned above.

[0077] The double-sided adhesive strip(s) are placed on the 1st stacking portion or the 2nd stacking portion in such a manner that they are no longer present in the CCMs equipped on each of their faces with sub-joints after the cuts of step 8).

[0078] The double-sided adhesive strip may have a width between 1 mm and 100 mm, preferably between 3 mm and 30 mm.

[0079] The double-sided adhesive tape can be chosen from the products marketed by the company GERGONNE under the trade names GERGOTAPE 3970 and GERGOTAPE 3990.

[0080] The double-sided adhesive strip(s) ensure that the first and second stacking portions do not shift from each other when the carrier film is removed.

[0081] In addition, because the double-sided adhesive strip(s) have the effect of sticking the first stacking portion to the second stacking portion during step 6) of folding, and that the said first and second stacking portions do not shift from each other when the carrier film is removed.

[0082] In an advantageous embodiment of the invention, during folding step 6), the second portion of the stack is pre-sealed with heat onto the first portion of the stack to secure them and facilitate subsequent removal of the carrier film. This pre-sealing can be performed with a rotary or flat heated tool readily available to those skilled in the art.

[0083] Optionally, at the end of step 2) or during any subsequent step of the manufacturing process according to the invention before carrying out step 6) of folding, at least one guide hole is made in the first stacked portion of the assembly formed by the superposition of the under-joint material layer and the thermoactivatable adhesive layer, and at least one guide hole in the second portion of stacking in the assembly formed by the superposition of the layer of underjoint material and the layer of thermoactivatable adhesive, said at least one guide hole in the 1st portion of stacking and said at least one guide hole in the 2nd portion of stacking being configured to be coupled together at the end of step 6) of folding such that a guide punch can be introduced into these guide holes to ensure that the 2nd portion of stacking is positioned perfectly correctly on the 1st portion of stacking.

[0084] Thanks to the guide punch introduced into these guide holes, the cuts of step 8) can be made precisely, reliably and perfectly centered with respect to the CCMs to obtain a set of CCMs equipped on each of their faces with a perfectly positioned sub-seal.

[0085] In other words, said at least one guide hole in the 1st stacking portion and said at least one guide hole in the 2nd stacking portion are configured in such a way that at the end of step 6) of folding, their centers overlap perfectly.

[0086] In one embodiment of the invention, these guide holes may consist of circular holes. For example, the diameter of the circular holes located in the first stacking portion may be slightly smaller than the diameter of the circular holes located in the second stacking portion, or vice versa. In one embodiment of the invention, the diameter of the circular holes located in the first stacking portion may be between 70% and 95% of the diameter of the circular holes located in the second stacking portion. In another embodiment of the invention, the diameter of the circular holes located in the second stacking portion may be between 70% and 95% of the diameter of the circular holes located in the first stacking portion.

[0087] These circular holes in the first and second stacking sections are arranged appropriately so that, after step 6) of folding the second stacking section onto the first stacking section, the centers of these circular holes overlap. This ensures the perfect positioning of the second stacking section onto the first stacking section for step 8) of cutting to obtain CMTs equipped on each of their faces with an identical sub-joint, all without any defects in the positioning of the sub-joints (i.e., without any slight offset in the positioning of the sub-joints).

[0088] When more than 2 guide holes are made in the first stacking portion and the second stacking portion, these guide holes are preferably made on both sides of the CCM.

[0089] In one embodiment of the invention, such guide holes are present near each CCM.

[0090] In another embodiment of the invention, such guide holes are present only in the vicinity of a part of the CCMs.

[0091] The guide holes are positioned so that they are no longer present on the CCMs equipped on each of their faces with a one-joint obtained at the end of step 8) of final cuts.

[0092] The CCMs implemented during said manufacturing process are CCMs conventionally implemented in MEAs.

[0093] Since the surface area of ​​the CCM is greater than the surface area of ​​the central openings, the CCM completely covers the central opening and extends over the entire periphery of said central opening, for example over a length between 1 mm and 15 mm, preferably between 2 mm and 15 mm, more preferably between 3 mm and 6 mm.

[0094] As explained above, in the 1st and 2nd stacking portions, the central openings can be in the form of one or more rows of a plurality of central openings, said rows of central openings all being parallel to the axis of the dashed pre-cut line.

[0095] Two consecutive CCMs on the same row can be spaced between them by a distance of between 10 mm and 200 mm, preferably between 30 mm and 180 mm, more preferably between 50 mm and 150 mm.

[0096] The CCMs of two consecutive rows can be spaced between them by a distance of between 10 mm and 200 mm, preferably between 30 mm and 180 mm, more preferably between 50 mm and 150 mm.

[0097] In step 5), the technique implemented to deposit the CCMs on each central opening of the first portion of the stack is perfectly within the reach of a person skilled in the art.

[0098] In step 5), the CCMs can, for example, be deposited using a guided robot. It may also be possible to perform continuous cutting of CCMs by rotary cutting from a roll of CCM material and, by means of a set of suction cylinders / calenders, to deposit said CCMs onto each central opening of the first portion of the stack.

[0099] In step 6) of the CCM manufacturing process with sub-seals according to the invention, the 2nd stacking portion is folded and folded over the 1st stacking portion.

[0100] At the end of step 6) of the CCM manufacturing process with sub-seals according to the invention, each CCM is sandwiched between the assembly formed by the superposition of the thermoactivatable adhesive layer and the sub-seal material layer of the first stacking portion and the assembly formed by the superposition of the thermoactivatable adhesive layer and the under-joint material layer of the 2nd stacking portion.

[0101] The hot sealing in step 7) of the manufacturing process for CTMs with sub-seals according to the invention can be carried out using a flat heating press. Step 7) is perfectly feasible for a person skilled in the art.

[0102] Optionally, after step 7) and before step 8), the stack of layers of material folded in half and sealed can be rolled up. It will then be unrolled when step 8 is carried out.

[0103] As explained above, the carrier film is removed at any time from the end of step 6) of folding of the CCM manufacturing process with sub-seals according to the invention.

[0104] Thus, the films carrying the 1st and 2nd stacking portions can be removed at the same time at the end of step 6) or step 7) or even step 8).

[0105] The carrier film of the 1st stacking portion and the carrier film of the 2nd stacking portion can be removed during the same step of the manufacturing process of CTM with sub-seals according to the invention or at different steps.

[0106] In one embodiment of the invention, only the carrier film of the 1st or 2nd portion of the stack is removed at the end of step 6) or step 7), and this in particular when the stack of layers of material folded in half and sealed is rolled up at the end of step 7), the remaining carrier film (namely of the 2nd portion or the 1st portion of the stack) is removed after the completion of step 8). Retaining the carrier film of the 1st or 2nd portion of the stack has the following advantages: - ensuring a certain rigidity to the stack of layers of material folded in half, where applicable pre-sealed, then sealed; - facilitate the optional pre-heat sealing of step 6), as well as the hot sealing of step 7), while ensuring dimensional stability.

[0107] Preferably, the carrier film of the second stacking portion is removed at the end of step 6) or step 7), particularly when the stack of folded and sealed material layers is rolled up at the end of step 7). The carrier film of the first stacking portion can be removed after step 8). The presence of the carrier film of the first stacking portion until at least the end of step 7) maintains a certain rigidity to the stack of folded and sealed material layers; this will facilitate the rolling and unrolling of this stack, and then, if necessary, the cutting in step 8), if the carrier film of the first stacking portion is removed after this step 8).

[0108] It is also possible to carry out step 8) of cutting in the presence of the two films carrying the 1st and 2nd stacking portions, and then remove them later.

[0109] The invention also relates to a method for manufacturing an assembly of MEAs, said manufacturing method comprising at least the following steps: - a set of CCMs is manufactured which are equipped on each of their faces with a sub-seal according to the manufacturing process according to the invention as described above; - we add a GDL on either side of each sub-joint in order to obtain a set of MEA.

[0110] The stack of layers of material folded in half and sealed obtained at the end of step 7) of the manufacturing process according to the invention is the product obtained at the end of the steps of this process which are carried out continuously from roll to roll. Step 8) of cutting can be carried out subsequently and results in CMTs equipped on each of their faces with an individual sub-seal.

[0111] Therefore, the invention also relates to an assembly comprising a layer of underseal material covered with a layer of thermoactivatable adhesive extending in a longitudinal direction and which is folded in two along the axis of a dashed pre-cut line made over all or part of the thickness of the assembly formed by the superposition of the layer of thermoactivatable adhesive and the layer of underseal material, extending in said longitudinal direction, and which is located at the center of the width of said assembly, thus defining: - a first portion of said under-joint material layer covered with a layer of thermoactivatable adhesive; - a second portion of said under-joint material layer covered with a layer of thermo-activatable adhesive, the thermo-activatable adhesive layers of the 1st portion and the 2nd portion being opposite each other and sandwiching a set of CCMs arranged along said longitudinal direction, The first and second portions of said under-joint material layer, each covered with a layer of thermo-activatable adhesive, comprise: - a set of central openings located centrally with respect to each of the CCMs, the surface area of ​​said central openings being less than the surface area of ​​the CCMs; - a set of lateral openings situated around said central openings, the lateral openings of said 1st portion being symmetrical with respect to the lateral openings of said 2nd portion with respect to the folding axis, optionally the face of the under-joint material layer opposite to the face in contact with the thermoactivatable adhesive layer of the 1st portion and / or the 2nd portion is covered with an adhesive layer which is itself covered with a carrier film.

[0112] The technical characteristics of the under-joint material layer, the thermoactivatable adhesive layer, the adhesive layer, and the carrier film have been described above.

[0113] In one embodiment of the invention, the face of the under-joint material layer opposite the face in contact with the thermoactivatable adhesive layer of the 1st portion and the 2nd portion are covered with an adhesive layer which is itself covered with a carrier film.

[0114] In one embodiment of the invention, only the face of the under-joint material layer opposite the face in contact with the thermoactivatable adhesive layer of the first portion is covered with an adhesive layer which is itself covered with a carrier film.

[0115] In one embodiment of the invention, said assembly is in the form of a roll.

[0116] In an embodiment of the invention, one or two double-sided adhesive strip(s) extending along an axis parallel to the axis of the dotted pre-cut line are arranged on the thermoactivatable adhesive layer of the 1st portion or the 2nd portion near said dotted pre-cut line and / or near the outer edge of said 1st or 2nd portion presented by said 1st and 2nd portions.

[0117] The adhesive strip(s) may have the technical characteristics that have been described above.

[0118] In one embodiment of the invention, the first and second portions each comprise at least one guide hole whose centers perfectly overlap. The guide holes may have the technical characteristics described above.

[0119] The invention will be better understood with the aid of the detailed description set forth below with reference to the accompanying drawing depicting:

[0120] [Fig-1] The [Fig.1] is a schematic perspective and exploded view of a MEA.

[0121] [Fig.2]. [Fig.2] is a schematic top view of a stack of layers of materials obtained at the end of step 2) of the CCM manufacturing process with sub-joints according to the invention.

[0122] [Fig.2a]. The [Fig.2a] is a schematic cross-sectional view along the Ila-IIa axis of the [Fig.2] of the stack of material layers obtained at the end of step 2) and represented in the [Fig.2].

[0123] [Fig.3]. The [Fig.3] is a schematic view of the top of the stack of material layers divided in two and cut out obtained at the end of step 4) of the manufacturing process of CTM with sub-joints according to the invention.

[0124] [Fig.3a]. The [Fig.3a] is a schematic cross-sectional view along the axis IIa-IIIa of the [Fig.3] of the stack of material layers divided in two and cut obtained at the end of step 4) of the manufacturing process of CTMs equipped with sub-seals according to the invention and represented in the [Fig.3].

[0125] [Fig.3b]. The [Fig.3b] is a schematic cross-sectional view along the same axis as the axis IIa-IIIa of the [Fig.3] of another embodiment of the stacking of layers of material divided in two and cut obtained at the end of step 4) of the manufacturing process of CTM with sub-joints according to the invention which is shown in figures 3 and 3a.

[0126] [Fig.4]. The [Fig.4] is a schematic top view of the schematic stack of material layers divided in two and cut out and comprising a set of CCM obtained at the end of step 5) of the CCM manufacturing process with sub-joints according to the invention.

[0127] [Fig.4a]. The [Fig.4a] is a schematic cross-sectional view along the IVa-IVa axis of the [Fig.4] of the stack of material layers divided into two and cut and comprising a set of CTMs obtained at the end of step 4) of the CTM manufacturing process with sub-joints according to the invention and represented in the [Fig.4].

[0128] [Fig.5]. The [Fig.5] is a schematic view of the top of the stack of layers of material folded in half obtained at the end of step 6) of the manufacturing process of CTM with sub-joints according to the invention.

[0129] [Fig.5a]. The [Fig.5a] is a schematic cross-sectional view along the Va-Va axis of the [Fig.5] of the stack of layers of material folded in half obtained at the end of step 6) of the manufacturing process of CTM with sub-joints according to the invention and represented in the [Fig.5].

[0130] [Fig.6]. The [Fig.6] is a schematic view of the top of the stack of layers of material folded in two obtained at the end of step 6) of the manufacturing process of CTM with sub-joints according to the invention after removal of the carrier film from the 2nd portion of the stack.

[0131] [Fig.6a]. The [Fig.6a] is a schematic cross-sectional view along the Via-Via axis of the [Fig.6] of the stack of layers of material folded in two obtained at the end of step 6) of the manufacturing process of CTM with sub-joints according to the invention after removal of the carrier film from the 2nd portion of the stack and shown in the [Fig.6].

[0132] [Fig.6b]. The [Fig.6b] is a schematic cross-sectional view along the same axis as the Via-Via axis of the [Fig.6] of another embodiment of the stack of layers of material folded in two obtained at the end of step 6) of the manufacturing process of CTMs equipped with sub-seals according to the invention after removal of the carrier film of the 2nd portion of the stack which is shown in figures 6 and 6a.

[0133] [Fig.7]. Fig.7 is a schematic and perspective view of the implementation of steps 5) to 7) of the CCM manufacturing process with sub-seals according to the invention.

[0134] [Fig.8]. The [Fig.8] is a schematic view of the top of the stack of material layers divided in two and cut obtained at the end of step 4) of the manufacturing process of CTM with sub-joints according to the invention in a different embodiment than that shown in the [Fig.3].

[0135] The [Fig.1] has been described above.

[0136] Figures 2 and 2a schematically represent a stack 7 obtained at the end of step 2) of the manufacturing process according to the invention of a set of CCM 2 equipped on each of their faces with a sub-seal 3a,3b.

[0137] The stack 7 comprises a PET carrier film 8 with a thickness of 50 µm. One face 9 of the carrier film 8 is covered with a pressure-sensitive adhesive layer 10 with a thickness of 10 µm. The pressure-sensitive adhesive is an acrylic polymer. The pressure-sensitive adhesive layer 10 is covered with a backing material layer 11 with a thickness of 25 µm, the material of which is PEN. The face of the backing material layer 11 opposite the face in contact with the pressure-sensitive adhesive layer 10 is covered with a thermo-activatable adhesive layer, which is a polyester polymer and with a thickness of 15 µm.

[0138] The width of the stack 7 is 40 cm. In other words, the width of the carrier film 8 and the width of the under-joint material layer 11 are 40 cm.

[0139] Figures 3 and 3a schematically represent the stack 7ii of layers of material divided in two and cut obtained at the end of step 4) of the manufacturing process of CCM 2 with sub-joints 3a,3b according to the invention.

[0140] A pre-cutting line in dotted lines 13 was made using a rotary cutting tool extending along the longitudinal direction of the stack of material layers 7 shown in Figures 2 and 2a and in the middle thereof.

[0141] The dashed pre-cut line 13 extends over 100% of the thickness of the assembly formed by the superposition of the thermoactivatable adhesive layer 12 and the under-joint material layer 11. The ratio between the cut area of ​​said pre-cut line 13 and the uncut area of ​​said pre-cut line 13 is 50%, with a cut of 3 mm in length by a step of 6 mm.

[0142] As can be seen in [Fig. 3a], a cut 23 of the assembly formed by the superposition of the carrier film 8 and the adhesive layer 10, which extends in a direction parallel to the axis of the dashed pre-cut line 13, was made using a rotary cutting tool. The width of the cut 23 is 100 µm.

[0143] The dashed pre-cut line 13 and the cut 23 divide the stack of material layers 7 shown in Figures 2 and 2a into 2 so as to obtain a first portion of the stack 14a and a second portion of the stack 14b. The The carrier film 8 is thus divided into 2 portions of carrier film 8a, 8b. The adhesive layer is divided into 2 portions of adhesive 10a, 10b. The under-joint material layer is divided into 2 portions 1a, 1b. The thermoactivatable adhesive layer is divided into 2 portions 12a, 12b.

[0144] The first stacking portion 14a thus comprises the superposition of the following elements: carrier film 8a having a face 9a covered with a layer of adhesive 10a, layer of under-joint material 1a and layer of thermoactivatable adhesive 12a.

[0145] The 2nd stacking portion 14b thus comprises the superposition of the following elements: carrier film 8b having a face 9b covered with a layer of adhesive 10b, layer of under-seal material 11b and layer of thermoactivatable adhesive 12b.

[0146] Furthermore, in the first portion of the stack 14a, cuts were made in the assembly formed by the superposition of the under-joint material layer 1a and the thermo-activatable adhesive layer 12a to obtain rectangular central openings 5a (width 4.5 cm and length 9.5 cm). These dimensions correspond to the central openings of PEMFC MEA under-joints.

[0147] In the 2nd stacking portion 14b, cuts were made in the assembly formed by the superposition of the under-joint material layer 11b and the thermoactivatable adhesive layer 12b so as to obtain central openings 5b of rectangular shape and of dimensions identical to the central openings 5a.

[0148] The central openings 5a of the 1st stacking portion 14a are symmetric to the central openings 5b of the 2nd stacking portion 14b with respect to the axis of the dashed pre-cut line 13.

[0149] Lateral openings such as described above, the arrangement of which in relation to the central openings 5a,5b and the dimensions of which correspond to the lateral openings of sub-seals of PEMFC MEA, are not shown in the figures for reasons of clarity.

[0150] Furthermore, at the end of step 2) of the manufacturing process of CCM 2 with sub-seals 3a,3b according to the invention: - a double-sided adhesive strip 16 was placed 1 cm from the dotted pre-cut line 13 on the thermoactivatable adhesive layer 10a; - a double-sided adhesive strip 15 was placed on the thermoactivatable adhesive layer 10a at 1 cm from the outer edge of the first stacking portion 14a.

[0151] During step 4) of the manufacturing process of CCM 2 with sub-seals 3a,3b according to the invention: - Circular guide holes 17a, 18a with a diameter of 1 cm were made in the first portion of stacking 14a in the assembly formed by the superposition of the layer of under-joint material 1 la and the layer of thermoactivatable adhesive 12a; - Circular guide holes 17b, 18b with a diameter of 1.2 cm were made in the 2nd stacking portion 14b in the assembly formed by the superposition of the under-joint material layer 11b and the thermoactivatable adhesive layer 12b.

[0152] The guide holes 17a are located near the dashed pre-cut line 13 and the guide holes 18a are located near the outer edge of the first stacking portion 14a.

[0153] The guide holes 18b are located near the dashed pre-cut line 13 and the guide holes 17b are located near the outer edge of the 2nd stacking portion 14b.

[0154] The guide holes 17a, 18a, 17b, 18b are arranged such that, at the end from step 6) of folding the 2nd stacking portion 14b onto the 1st stacking portion 14a, the centers of the guide holes on one side 17a and 18b and 18a and 17b on the other side overlap perfectly.

[0155] Figure 3b shows another embodiment of the stacking of layers of material divided in two and cut 7ii shown in figures 3 and 3a.

[0156] Indeed, the stacking 7ii shown in [Fig.3b] differs from that shown in Figures 3 and 3a in that the width of the carrier film 8 is 38 cm (and not 40 cm).

[0157] The width of the under-joint material layer 11 is 40 cm. The width of the under-joint material layer 11 is therefore greater than the width of the carrier film 8.

[0158] The width of the cut 23 being 100 pm, in the first stacking portion 14a, the assembly formed by the superposition of the under-joint material layer 1a and the thermoactivatable adhesive layer 12a protrudes from the assembly formed by the superposition of the carrier film 8a and the adhesive layer 10a: - with a length of 50 pm on the side of the dotted pre-cut line 13; - with a length of 1 cm on the side opposite the dotted pre-cut line 13.

[0159] Furthermore, in the 2nd stacking portion 14b, the assembly formed by the superposition of the under-joint material layer 11b and the thermo-activatable adhesive layer 12b protrudes from the assembly formed by the superposition of the carrier film 8b and the adhesive layer 10b: - with a length of 50 pm on the side of the dotted pre-cut line 13; - with a length of 1 cm on the side opposite the dashed pre-cut line 13.

[0160] This embodiment of the invention is advantageous because during the optional hot pre-sealing of step 6) and during the hot sealing of step 7), these portions of the assembly formed by the superposition of the under-seal material layer 1a,1b and the thermoactivatable adhesive layer 12a,12b which protrude on both sides and other parts of the assembly formed by the superposition of the carrier film 8a,8b and the adhesive layer 10a,10b will be more easily sealed together.

[0161] Figures 4 and 4a represent the stack 7iii of layers of material divided in two and cut which comprises a set of CCM 2 obtained at the end of step 5) of the CCM 2 manufacturing process with sub-joints 3a,3b according to the invention.

[0162] All the CTL 2s had a rectangular shape (width: 5 cm and length 10 cm) and a thickness of 100 pm. They were composed of the superposition of the following material layers: a layer of platinum catalytic ink, a polymer electrolyte membrane comprising an ionomer, a PTFE layer, a polymer electrolyte membrane comprising an ionomer and a layer of platinum catalytic ink.

[0163] A CCM 2 was placed on each central opening 5a of the first stacking portion 14a, and this in a manner centered with respect to said central opening 5a. The CCM 2s were spaced 12 cm apart.

[0164] During step 6) of the manufacturing process of CCM 2 with sub-seals 3a,3b, the 2nd stack portion 14b was folded and pre-sealed with a rotating thermal pre-sealing device on the 1st stack portion 14a along the axis of the dashed pre-cut line 13 so as to obtain the stack 7iv of layers of material folded in 2 as shown in Figures 5 and 5a.

[0165] Next, the carrier film 8b and the adhesive layer 10b of the 2nd stacking portion 14b was removed so as to obtain a stack 7v of layers of material folded in half devoid of the carrier film 8b and adhesive layer 10b and still including the carrier film 8a and the adhesive layer 10a as shown in Figures 6 and 6a.

[0166] Figure 6b shows another embodiment of the stack 7v shown in Figures 6 and 6a. This is the stack 7v obtained from the stack 7ii of layers of material divided in two and cut as shown in Figure 3b from which steps 5) and 6) of the manufacturing process of CTM 2 with sub-joints 3a,3b according to the invention were carried out and after removal of the carrier film 8b and the adhesive layer 10b from the 2nd portion of the stack 14b.

[0167] Figure 7 schematically represents an installation 22 for carrying out certain steps in the manufacturing process of CCM 2 with sub-seal 3a, 3b according to the invention, namely after unwinding by means of an unwinding device 19 of the stack 7ii of layers of material divided in two and cut: - step 5) of depositing CCM 2 on the central openings 5a of the first portion of stacking 14a so as to obtain a stacking 7iii of layers of material divided in two and cut including CCM 2; - step 6) of folding the 2nd stacking portion 14b onto the 1st stacking portion 14a by performing a hot pre-sealing using a rotating thermal pre-sealing device 20 so as to obtain a stack 7iv of layers of material folded in two and pre-sealed; - the removal of the carrier film 8b from the 2nd portion of stacking 14b so as to obtain a stacking 7v of layers of material folded in half and pre-sealed without the carrier film 8b from the 2nd portion of stacking 14b; - step 7) of hot sealing the stack 7v in a flat thermal sealing device 21 so as to obtain the stack 7vi of layers of material folded in half and sealed.

[0168] This stack 7vi can then be subjected to step 8) of cutting of the CTM manufacturing process with sub-seals according to the invention in a suitable cutting device which is perfectly within the reach of a person skilled in the art but which is not shown in [Fig.7].

[0169] The stack 7ii of layers of material divided in two and cut, obtained at the end of step 4) of the manufacturing process of CTM 2 with sub-seals 3a, 3b according to the invention, shown in [Fig. 8], is a different embodiment from that shown in [Fig. 3]. Indeed, the stack 7ii comprises: - in the first portion of stacking 14a 3 rows 24a,25a,26a of central openings 5a; - in the 2nd stacking section 14b 3 rows 24b,25b,26b of central openings 5b.

[0170] Each row 24a, 25a, 26a comprises 5 central openings 5a. Each row 24b, 25b, 26b comprises 5 central openings 5b. All rows 24a, 25a, 26a, 24b, 25b, 26b are parallel to the axis of the dashed pre-cut line (13).

[0171] Rows 24a, 25a, 26a are respectively symmetrical to rows 24b, 25b, 26b relative to the axis of the dotted pre-cut line (13).

[0172] The spacing between two consecutive central openings (5a,5b) of the same row 24a,25a,26a,24b,25b,26b is the same throughout the stack 7ii and is 12 cm.

[0173] The spacing between rows 24a and 25a, rows 25a and 26a, rows 24b and 25b and rows 25b and 26b is always the same and is 11 cm.

Claims

1. Demands A method for manufacturing an assembly of catalyst-coated membranes (hereinafter abbreviated CCM) (2), each face of which is equipped with a sub-seal (3a, 3b), characterized in that said manufacturing method comprises at least the following steps: 1) we have a carrier film (8) extending along a longitudinal direction, one of whose two faces (9) is covered with a layer of adhesive (10); 2) a layer of underseal material (11) is deposited on the adhesive layer (10) of the carrier film (8), the face of the underseal material layer (11) which is opposite to that which is in contact with said adhesive layer (10) is covered with a layer of thermoactivatable adhesive (12) so as to obtain a stack (7) of material layers, extending along the longitudinal direction of said carrier film (8); 3) We perform: - a dashed pre-cut line (13), extending along the longitudinal direction of said stack (7) of material layers obtained at the end of step 2), in the middle of said stack (7), said dashed pre-cut line (13) being made over all or part of the thickness of the assembly formed by the superposition of the thermoactivatable adhesive layer (12) and the under-joint material layer (11) and - a cut (23) through the entire thickness of the assembly formed by the superposition of the carrier film (8) and the adhesive layer (10) which extends in a direction parallel to the axis of the dotted pre-cut line (13), so as to obtain a stacking of material layers divided into two which includes a first portion of stacking (14a) and a second portion of stacking (14b); 4) Cuts are made in the assembly formed by the superposition of the under-joint material layer (11) and the thermo-activatable adhesive layer (12) at the level of the 1st and 2nd stacking portions (14a, 14b) so as to obtain a stack (7ii) of material layers divided in two and cut which includes in the 1st and 2nd stacking portions (14a, 14b) central openings (5a, 5b) whose dimensions correspond to central openings of sub-seals (3a,3b) of a membrane electrode assembly (hereinafter abbreviated MEA) (1), said central openings (5a) of the 1st portion of stacking (14a) being symmetrical to the central openings (5b) of the 2nd portion of stacking (14b) with respect to the axis of said dashed pre-cut line (13); 5) a CCM (2) is placed, in a central manner, on each central opening (5a) of the first portion of the stack (14a), said CCM (2) having a surface greater than said central opening (5a) so as to cover it entirely and to obtain a stack (7iii) of layers of material divided into two and cut which includes a set of CCM (2); 6) the 2nd stacking portion (14b) is folded over the 1st stacking portion (14a) along the axis of the dotted pre-cut line (13), optionally by performing a hot pre-sealing of the 2nd stacking portion (14b) on the 1st stacking portion (14a), so as to obtain a stack (7iv) of material layers folded in half and optionally pre-sealed; 7) a hot sealing is carried out of the stack (7iv) of layers of material folded in half and optionally pre-sealed obtained at the end of step 6) so as to obtain a stack (7vi) of layers of material folded in half and sealed; 8) cuts are made in the stack (7vi) of layers of material folded in half and sealed obtained at the end of step 7) so as to obtain a set of CCMs (2) equipped on each of their faces with a sub-seal (3a,3b), In addition, further cuts are made to obtain lateral openings (6a, 6b) whose arrangement relative to the central openings (5a, 5b) and dimensions correspond to lateral openings (6a, 6b) of sub-joints (3a, 3b) of MEA (1), said additional cuts are made: - during step 4) in the assembly formed by the superposition of the under-joint material layer (11) and the thermoactivatable adhesive layer (12) at the level of the 1st and 2nd stacking portions (14a, 14b), said lateral openings (6a) of the 1st stacking portion (14a) being symmetrical to the lateral openings (6b) of the 2nd stacking portion (14b) with respect to the axis of said dashed pre-cut line (13) or - at the end of step 7) in the stack (7vi) of layers of material folded in half and sealed, the carrier film (8) and the adhesive layer (10) are removed at any time from the end of step 6).

2. A manufacturing method according to claim 1, characterized in that the carrier film material (8) has a Young's modulus in tension, measured according to ASTM D638, of between 1 GPa and 100 GPa, preferably between 2 GPa and 50 GPa.

3. A manufacturing method according to claim 1 or 2, characterized in that the material of the carrier film (8) is chosen from the group consisting of polyethylene terephthalate and polypropylene.

4. A manufacturing method according to any one of claims 1 to 3, characterized in that the thickness of the carrier film (8) is between 12 pm and 350 pm, preferably between 23 pm and 250 pm, more preferably between 36 pm and 150 pm.

5. A manufacturing method according to any one of claims 1 to 4, characterized in that the surface mass of the thermoactivatable adhesive layer (12) is between 5 g / m2 and 150 g / m2, preferably between 10 g / m2 and 80 g / m2, more preferably between 15 g / m2 and 50 g / m2.

6. A manufacturing method according to any one of claims 1 to 5, characterized in that the width of the underseal material layer (11) is greater than the width of the carrier film (8), preferably between 0.1% and 20% greater than the width of the carrier film (8).

7. A manufacturing method according to any one of claims 1 to 6, characterized in that, during any step of said manufacturing process prior to the folding step (6), one or two double-sided adhesive strips (15, 16) are applied to the heat-activated adhesive layer (12) of the first stacking portion (14a) or to the heat-activated adhesive layer (12) of the second stacking portion (14b), extending in a direction parallel to the axis of the dashed pre-cut line (13), the double-sided adhesive strip(s) (15, 16) being positioned near the dashed pre-cut line (13) and / or near the outer edge of the first stacking portion (14a) or of the 2nd stacking portion (14b) which the said 1st and 2nd stacking portions (14a, 14b) present.

8. A manufacturing method according to any one of claims 1 to 7, characterized in that at the end of step 2) or during any subsequent step of said manufacturing process before carrying out step 6) of folding, at least one guide hole (17a,18a) is made in the first stacking portion (14a) in the assembly formed by the superposition of the underseal material layer (11) and the thermoactivatable adhesive layer (12) and at least one guide hole (17b,18b) is made in the second stacking portion (14b) in the assembly formed by the superposition of the underseal material layer (11) and the thermoactivatable adhesive layer (12), said at least one guide hole (17a,18a) in the first stacking portion (14a) and said at least one guide hole (17b,17b) in the 2nd stacking portion (14b) being configured in such a way that at the end of step 6) of folding, their centers overlap.

9. A method for manufacturing an assembly of MEA (1) characterized in that said method comprises at least the following steps: - an assembly of CCM (2) is manufactured which are equipped on each of their faces with a sub-seal (3a,3b) according to the manufacturing method according to any one of claims 1 to 8; - a gas diffusion layer (4a,4b) is added on either side of each sub-seal (3a,3b) so as to obtain an assembly of MEA(1).

10. Assembly comprising a layer of underseal material (11) covered with a layer of thermo-activatable adhesive (12) extending in a longitudinal direction and folded in half along the axis of a dashed pre-cut line (13) made over all or part of the thickness of the assembly formed by the superposition of the layer of thermo-activatable adhesive (12) and the layer of underseal material (11), extending in said longitudinal direction and located at the center of the width of said assembly thus defining: - a first portion (14a) of said layer of underseal material (11a) covered with a layer of thermo-activatable adhesive (12a), - a second portion (14b) of said layer of underseal material (11b) covered with a layer of thermo-activatable adhesive (12b), the thermoactivatable adhesive layers (12a, 12b) of the 1st portion (14a) and the 2nd portion (14b) being opposite each other and sandwiching a set of CCMs (2) arranged along said longitudinal direction, The first and second portions (14a, 14b) of said underseal material layer (11) covered with a thermoactivatable adhesive layer (12) each comprise: - a set of central openings (5a,5b) located centrally with respect to each of the CCMs (2), the surface area of ​​said central openings (5a,5b) being less than the surface area of ​​the CCMs (2); - a set of lateral openings (6a,6b) situated around said central openings (5a,5b), the lateral openings (6a) of said 1st portion (14a) being symmetrical with respect to the lateral openings (6b) of said 2nd portion (14b) with respect to the axis of the dotted pre-cut line (13), Optionally the face of the under-joint material layer (11) opposite the face in contact with the thermoactivatable adhesive layer (12) of the 1st portion (14a) and / or the 2nd portion (14b) is covered with an adhesive layer (10a,10b) which is itself covered with a carrier film (8a,8b).

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