A proton exchange membrane double-sided catalytic layer coating method and positioning protection film

Abstract

The application discloses a kind of proton exchange membrane double-side catalytic layer coating method and positioning protective film.The proton exchange membrane double-side catalytic layer coating method includes the following steps:S1: the protective film roll is punched out and handled, and the positioning protective film is formed.The positioning protective film has periodic active area cavity and periodic fitting positioning hole along its length direction;S2: the positioning pin on the fitting roll is inserted into the fitting positioning hole, and the first side and the second side of the proton exchange membrane are fitted with the positioning protective film, and the first catalytic layer and the second catalytic layer are formed respectively in the intermittent coating of the to-be-coated area of the first side and the second side of the proton exchange membrane.The positioning precision of the positioning protective film on both sides of the proton exchange membrane is improved, the active area cavity of the positioning protective film on both sides of the proton exchange membrane has higher alignment accuracy, the alignment deviation of the catalytic layer on both sides of the proton exchange membrane is reduced in the intermittent coating process, the possibility of chemical decay of membrane electrode material is reduced, and the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of proton exchange membrane coating methods, and in particular to a proton exchange membrane double-sided catalytic layer coating method and a positioning protective film. BACKGROUND

[0002] A membrane electrode (MEA) is a core component of a fuel cell system and is a key place for chemical energy to electric energy conversion. The composition of the membrane electrode includes a proton exchange membrane, a cathode / anode catalytic layer, a cathode / anode gas diffusion layer, and a sealing frame material.

[0003] With the increasing demand for high-power fuel cell systems in the vehicle market, the annual production capacity of membrane electrodes is gradually approaching the level of 10 million pieces, and the roll-to-roll direct coating technology with the advantages of continuous and high-efficiency production has been gradually applied in the preparation of CCM components to meet the demand for large-scale batch manufacturing of products. In addition to the high production capacity target, the product manufacturability and manufacturing precision are also crucial to the application of the membrane electrode.

[0004] In the CCM roll-to-roll direct coating process, the equipment correction system and the visual positioning control system are usually used to ensure the neatness of the proton exchange membrane winding process and the accurate relative position of the cathode / anode catalytic layer. At present, the single-sided coating size precision of high-precision slot coating equipment in the industry can reach ±1mm, but when double-sided direct coating is performed, the alignment deviation of the double-sided coating may increase to ±2mm. If non-transparent proton exchange membranes are used, the alignment deviation of the system based on visual positioning control will be further magnified, resulting in an increase in the alignment deviation of the double-sided catalytic layer, causing the chemical decay of the local membrane electrode material to intensify and shortening the service life of the membrane electrode.

[0005] Therefore, how to prolong the service life of the membrane electrode is a technical problem that needs to be solved by those skilled in the art at present. SUMMARY

[0006] Therefore, the purpose of the present application is to provide a proton exchange membrane double-sided catalytic layer coating method to prolong the service life of the membrane electrode.

[0007] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0008] A proton exchange membrane double-sided catalytic layer coating method, comprising the steps of:

[0009] S1: performing a punching process on a protective film roll to form a positioning protective film, the positioning protective film having a periodic active area cavity and a periodic fitting positioning hole along the length direction thereof;

[0010] S2: The positioning protection film is attached to the first side and the second side of the proton exchange membrane, the positioning pin on the attachment roller is inserted into the attachment positioning hole, and intermittent coating is performed on the to-be-coated area of the first side and the second side of the proton exchange membrane to form the first catalytic layer and the second catalytic layer, respectively.

[0011] Optionally, in the above-mentioned proton exchange membrane double-side catalytic layer coating method, the positioning protection film comprises a first positioning protection film and a second positioning protection film, and the step S2 comprises:

[0012] S2-A1: The first positioning protection film is attached to the first side of the proton exchange membrane in a roll-to-roll manner.

[0013] S2-A2: Intermittent coating is performed on the first side of the proton exchange membrane to form a first catalytic layer at the active area cavity opening of the first positioning protection film.

[0014] S2-A3: After drying the first catalytic layer, it is wound up.

[0015] S2-A4: The back film of the proton exchange membrane is torn off, and the second positioning protection film is attached to the second side of the proton exchange membrane in a roll-to-roll manner.

[0016] S2-A5: Intermittent coating is performed on the second side of the proton exchange membrane to form a second catalytic layer at the active area cavity opening of the second positioning protection film.

[0017] S2-A6: The second catalytic layer is dried, and the first catalytic layer and the second catalytic layer are simultaneously attached to the first supporting back film and the second supporting back film and wound up synchronously, the first supporting back film is located on the side of the first catalytic layer away from the proton exchange membrane, and the second supporting back film is located on the side of the second catalytic layer away from the proton exchange membrane.

[0018] Optionally, in the above-mentioned proton exchange membrane double-side catalytic layer coating method, if the thickness of the first positioning protection film exceeds a thickness threshold, the step S2-A5 and S2-A4 further comprise:

[0019] S2-B: The first positioning protection film is torn off.

[0020] Optionally, in the above-mentioned proton exchange membrane double-side catalytic layer coating method, the positioning protection film comprises a first positioning protection film and a second positioning protection film, and the step S2 comprises:

[0021] S2-C1: The first positioning protection film is attached to the first side of the proton exchange membrane in a roll-to-roll manner.

[0022] S2-C2: tear off the back film of the proton exchange membrane, and roll-to-roll adhere the second positioning protection film to the second side of the proton exchange membrane;

[0023] S2-C3: intermittently coat both sides of the proton exchange membrane to form a first catalytic layer and a second catalytic layer;

[0024] S2-C4: dry the first catalytic layer and the second catalytic layer, and simultaneously adhere and roll up the first catalytic layer and the second catalytic layer with a first supporting back film and a second supporting back film, the first supporting back film is located on the side of the first catalytic layer away from the proton exchange membrane, and the second supporting back film is located on the side of the second catalytic layer away from the proton exchange membrane.

[0025] Optionally, in the above-mentioned proton exchange membrane double-side catalytic layer coating method, in the step S2-C3, both sides of the proton exchange membrane are synchronously intermittently coated, or both sides of the proton exchange membrane are sequentially intermittently coated.

[0026] Optionally, in the above-mentioned proton exchange membrane double-side catalytic layer coating method, the positioning protection film includes a first positioning protection film and a second positioning protection film, and the step S2 includes:

[0027] S2-D1: roll-to-roll adhere the first positioning protection film to the first side of the proton exchange membrane;

[0028] S2-D2: tear off the back film of the proton exchange membrane, and roll-to-roll adhere the second positioning protection film to the second side of the proton exchange membrane;

[0029] S2-D3: intermittently coat the first side of the proton exchange membrane to form a first catalytic layer;

[0030] S2-D4: dry and roll up the first catalytic layer, and simultaneously peel off the first positioning protection film;

[0031] S2-D5: intermittently coat the second side of the proton exchange membrane to form a second catalytic layer;

[0032] S2-D6: dry the second catalytic layer, and simultaneously adhere and roll up the first catalytic layer and the second catalytic layer with a first supporting back film and a second supporting back film, the first supporting back film is located on the side of the first catalytic layer away from the proton exchange membrane, and the second supporting back film is located on the side of the second catalytic layer away from the proton exchange membrane.

[0033] Optionally, in the proton exchange membrane double-side catalytic layer coating method, after step S2, step S3 is further included: after sequentially tearing off the first supporting back film, the second supporting back film, the first positioning protection film and the second positioning protection film, the films are roll-bonded with the frame.

[0034] Optionally, in the proton exchange membrane double-side catalytic layer coating method, the active area cavity is a polygonal hole or a notched rectangular hole.

[0035] Optionally, in the proton exchange membrane double-side catalytic layer coating method, the positioning protection film includes a plurality of active area cavities, and the plurality of active area cavities are arranged side by side in the width direction of the positioning protection film.

[0036] Optionally, in the proton exchange membrane double-side catalytic layer coating method, the positioning protection film has a thickness of 110 o C, and a thermal shrinkage rate of 5 min is less than 0.1%; the positioning protection film has a thickness of 10-200 μm, and a tolerance of less than or equal to 10 μm; the slurry viscosity of the first catalytic layer and the second catalytic layer is 20-100000 mPa·s; and the slurry drying temperature of the first catalytic layer and the second catalytic layer is 50-100 o C.

[0037] A positioning protection film used in the proton exchange membrane double-side catalytic layer coating method, the positioning protection film has periodic active area cavities and periodic bonding positioning holes along the length direction of the positioning protection film, and the bonding positioning holes are used for inserting and cooperating with positioning pins on a bonding roller.

[0038] In the proton exchange membrane double-side catalytic layer coating method, the positioning protection film is punched from a protection film roll, and has periodic active area cavities and periodic bonding positioning holes along the length direction of the positioning protection film. Then, the positioning protection film is bonded on the first side and the second side of the proton exchange membrane, the first side and the second side of the proton exchange membrane are two opposite sides of the proton exchange membrane, and the first catalytic layer and the second catalytic layer are respectively formed by intermittent coating on the to-be-coated areas of the first side and the second side of the proton exchange membrane. Since the positioning protection film has periodic bonding positioning holes along the length direction of the positioning protection film, the positioning accuracy of the positioning protection film on the two sides of the proton exchange membrane is improved by the cooperation between the bonding positioning holes and the positioning pins on the bonding roller, the active area cavities of the positioning protection film on the two sides of the proton exchange membrane have high alignment accuracy, the alignment accuracy of the first catalytic layer and the second catalytic layer is effectively improved during the intermittent coating process, the alignment deviation of the catalytic layers on the two sides of the proton exchange membrane is reduced, the possibility of chemical decay of the membrane electrode material is reduced, and the service life of the membrane electrode is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the structure of the first positioning protective film provided in an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the structure after forming a first catalytic layer and a second catalytic layer on both sides of a proton exchange membrane, as provided in an embodiment of the present invention.

[0042] Figure 3 This is a schematic diagram of the structure of the second positioning protective film provided in an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of the structure of the third positioning protective film provided in an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the structure of the fourth type of positioning protective film provided in an embodiment of the present invention.

[0045] Among them, 100 is the positioning protective film, 101 is the active area cavity, 102 is the bonding positioning hole, 103 is the coating guide mark, 100-a is the first positioning protective film, 100-b is the second positioning protective film, 200 is the proton exchange membrane, 300 is the first catalyst layer, 400 is the second catalyst layer, 500 is the first supporting back membrane, and 600 is the second supporting back membrane. Detailed Implementation

[0046] In view of this, the core of the present invention is to provide a method for coating the catalytic layer on both sides of a proton exchange membrane to extend the membrane electrode life.

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] like Figures 1 to 5 As shown, this embodiment of the invention discloses a method for coating a proton exchange membrane with a double-sided catalytic layer, comprising the following steps:

[0049] S1: cutting the protective film roll to form the positioning protective film 100, so that the positioning protective film 100 has the periodic active area cavity 101 and the periodic fitting positioning hole 102 along the length direction of the positioning protective film 100.

[0050] S2: fitting the positioning protective film 100 on the first side and the second side of the proton exchange membrane 200, the positioning pin on the fitting roller is inserted into the fitting positioning hole 102, and intermittent coating is performed on the to-be-coated area of the first side and the second side of the proton exchange membrane 200 to form the first catalytic layer 300 and the second catalytic layer 400, respectively.

[0051] In the proton exchange membrane double-side catalytic layer coating method provided by the application, the protective film roll is cut to form the positioning protective film 100, so that the positioning protective film 100 has the periodic active area cavity 101 and the periodic fitting positioning hole 102 along the length direction of the positioning protective film 100. Then, the positioning protective film 100 is fitted on the first side and the second side of the proton exchange membrane 200. The first side and the second side of the proton exchange membrane 200 are two opposite sides of the proton exchange membrane 200. Intermittent coating is performed on the to-be-coated area of the first side and the second side of the proton exchange membrane 200 to form the first catalytic layer 300 and the second catalytic layer 400, respectively. Since the positioning protective film 100 has the periodic fitting positioning hole 102 along the length direction of the positioning protective film 100, the positioning accuracy of the positioning protective film 100 on both sides of the proton exchange membrane 200 can be improved through the cooperation between the fitting positioning hole 102 and the positioning pin on the fitting roller. The active area cavity 101 of the positioning protective film 100 on both sides of the proton exchange membrane 200 has high alignment accuracy. Therefore, the alignment accuracy of the first catalytic layer 300 and the second catalytic layer 400 can be effectively improved during intermittent coating, the alignment deviation of the catalytic layers on both sides of the proton exchange membrane 200 is reduced, the possibility of chemical decay of the membrane electrode material is reduced, and the service life of the membrane electrode is prolonged.

[0052] It should be noted that the active area cavity opening 101 can be a rectangular hole, a diamond hole, a polygonal hole, an angle-deficient rectangular hole or any pre-set special-shaped hole, as long as the shape can meet the use requirements, which belongs to the protection scope of the present application. Based on the pattern expansion of the active area cavity opening 101, the coating shape is expanded, the uneven distribution of reaction gas and liquid water caused by the rectangular structure of the CCM is reduced, thereby reducing the difference in temperature and current density of different areas, prolonging the service life of the membrane electrode and improving the consistency of the membrane electrode. Moreover, the active area cavity opening 101 can be single or multiple, and in actual application, the number of the active area cavity opening 101 can be adaptively adjusted according to the actual coating scheme. Optionally, the active area cavity opening 101 provided in the embodiment of the present application is multiple, so that the catalytic layer is expanded from the traditional single long rectangular CCM to multiple angle-deficient rectangular CCMs, multiple diamond CCMs or multiple polygonal CCMs, so as to effectively improve the uneven distribution of reaction gas and liquid water in the actual operation of the membrane electrode, and further improve the long-life operation capability of the membrane electrode product.

[0053] Specifically, as shown in the drawings, Figure 3 in a specific embodiment of the present application, the positioning protective film 100 arranges two active area cavity openings 101 in the width direction, and the shape of the active area cavity opening 101 is an angle-deficient rectangle; as shown in the drawings, Figure 4 in another specific embodiment of the present application, the positioning protective film 100 arranges two active area cavity openings 101 in the width direction, and the shape of the active area cavity opening 101 is a hexagon; as shown in the drawings, Figure 5 in another specific embodiment of the present application, the positioning protective film 100 arranges three active area cavity openings 101 in the width direction, and the shape of the active area cavity opening 101 is an octagon.

[0054] The positioning protective film 100 provided in the present application can also selectively add a coating guide mark 103 according to the coating head sensor control capability and the advancing precision; in addition, the proton exchange membrane 200 and the positioning protective film 100 are attached by a roll-to-roll device, and the roll-to-roll attachment scheme includes but is not limited to electrostatic attachment, pressure-sensitive attachment, hot melt adhesive attachment or light-cured attachment technology; and the attachment surface of the positioning protective film 100 needs to have certain initial adhesion characteristics, and the interfacial peeling force after attachment needs to be greater than the interfacial peeling force of the proton exchange membrane 200 and the back film.

[0055] It should be understood that the present application does not make specific limitation on the order of the lamination of the positioning protective film 100 and the coating of the catalytic layer, and in actual application, the order of the lamination of the positioning protective film 100 and the coating of the catalytic layer can be adjusted according to the material properties of the positioning protective film 100, the material properties of the proton exchange membrane 200, and the process properties of the coating slurry, as well as the control accuracy and the implementation difficulty of the winding and unwinding equipment and the selected mechanical equipment for coating.

[0056] Specifically, in the first specific embodiment of the present application, the protective film web is a PET protective film web, and the PET protective film web is punched by a punching device to form a punching structure as shown in Figure 3 The punching structure includes the lamination positioning hole 102 and two active area cavities 101, and the active area cavities 101 are shaped as a missing corner rectangle lamination positioning hole 102.

[0057] The positioning protective film 100 includes a first positioning protective film 100-a and a second positioning protective film 100-b, and the positioning protective film 100 can be defined as an anode positioning protective film 100 and a cathode positioning protective film 100 according to the properties of the catalytic layer to be coated, that is, one of the first positioning protective film 100-a and the second positioning protective film 100-b is the anode positioning protective film 100, and the other is the cathode positioning protective film 100, and the step S2 includes:

[0058] S2-A1: using a roll-to-roll lamination device to roll-to-roll laminate the first side of the commercialized proton exchange membrane 200 with the first positioning protective film 100-a to form a composite film roll 1.

[0059] In the above step S2-A1, the positioning of the area to be coated in the proton exchange membrane 200 is realized by CCD visual detection winding correction, and the positioning accuracy is required to be ±0.05 mm; the thickness of the proton exchange membrane 200 is 15 μm±1.5 μm, the interfacial peeling force between the proton exchange membrane 200 and the back film is 0.008 N / mm; the side to be laminated of the first positioning protective film 100-a is coated with UV debonding glue, and the thickness of the glue is 90±10 μm, and the initial adhesion property is that the interfacial peeling force after 0.2 MPa roller lamination with the proton exchange membrane 200 is 0.02 N / mm.

[0060] S2-A2: The composite membrane roll 1 is transmitted at a certain speed in the first coating station. In the embodiment of the present application, the first positioning protective film 100-a is a cathode positioning protective film 100, the second positioning protective film 100-b is an anode positioning protective film 100, and the first coating station is a cathode coating station. When the positioning sensor detects the edge of the active cavity area of the first positioning protective film 100-a, the device drives the coating head to intermittently coat the cathode catalyst layer on the first side of the proton exchange membrane 200 at a specified length. The coating range is required to be larger than the size of the active area cavity 101 of the cathode positioning protective film 100, so as to form the cathode catalyst layer on the active area cavity 101 of the cathode positioning protective film 100.

[0061] In the above-mentioned S2-A2, the coating scheme is doctor blade coating, the wet film thickness of the cathode slurry is about 110 μm, and the viscosity is 51000±2500 mPa·s.

[0062] S2-A3: After the roll coated with the cathode catalyst layer is dried in the drying box, the composite membrane roll 2 is formed. The drying temperature is 90±2 o C.

[0063] S2-A4: The back film of the proton exchange membrane 200 is torn off on the composite membrane roll 2, and at the same time, the anode positioning protective film 100 is positioned with the proton exchange membrane 200 through the fitting positioning hole 102 on the anode positioning protective film 100. The second side of the anode positioning protective film 100 is roll-to-roll fitted with the proton exchange membrane 200 to form the composite membrane roll 3.

[0064] In the above-mentioned step S2-A4, the alignment accuracy of the active area cavities 101 on both sides of the proton exchange membrane 200 in the coating direction and the width direction is required to be ±0.02 mm, so that the catalyst layers on both sides of the proton exchange membrane 200 have high alignment accuracy; the side to be fitted of the anode positioning protective film 100 is coated with UV debonding adhesive with a thickness of 20±5 μm, and the initial adhesion characteristic is that the interfacial peeling force is 0.02 N / mm after the 0.2 MPa roller is pressed and fitted with the proton exchange membrane 200.

[0065] S2-A5: The composite membrane roll 3 is transmitted at a certain speed in the anode coating station. When the positioning sensor detects the edge of the active cavity area of the anode positioning protective film 100, the device drives the coating head to intermittently coat the anode catalyst layer on the second side of the proton exchange membrane 200 at a specified length. The coating range is required to be larger than the size of the active area cavity 101 of the anode positioning protective film 100, so as to form the anode catalyst layer on the active area cavity 101 of the anode positioning protective film 100.

[0066] In the above-mentioned step S2-A5, the coating scheme is slot coating, the wet film thickness of the anode slurry is about 30 μm, and the viscosity is 35±15 mPa·s.

[0067] S2-A6: The roll coated with the anode catalytic layer is wound at 65±2 o C While drying, the anode catalytic layer and the cathode catalytic layer are attached to the first supporting back film 500 and the second supporting back film 600 and are wound synchronously, the first supporting back film 500 is located on the side of the cathode catalytic layer away from the proton exchange membrane 200, and the second supporting back film 600 is located on the side of the anode catalytic layer away from the proton exchange membrane 200.

[0068] Further, based on the thickness difference of the first positioning protective film 100-a in the above step S2-A1, if the thickness of the first positioning protective film 100-a exceeds the thickness threshold, that is, the first positioning protective film 100-a is too thick, the thickness difference between the first positioning protective film 100-a and the proton exchange membrane 200 is large, which is not conducive to the control of the coating thickness. At this time, between steps S2-A5 and S2-A4, there is also a step S2-B: the first positioning protective film 100-a is torn off, so as to remove the first positioning protective film 100-a with a larger thickness before coating, thereby facilitating the control of the coating thickness.

[0069] Specifically, in the second specific embodiment of the present application, the proton exchange membrane double-side catalytic layer coating method comprises the following steps:

[0070] S2-B1. The PET protective film tape is punched by a punching device to form a punching structure as shown in Figure 5 The punching structure is attached to the positioning hole 102 and the three active area cavities 101, and the active area cavities 101 are octagonal in shape.

[0071] S2-B2. The first side of the commercialized proton exchange membrane 200 is attached to the cathode positioning protective film 100 by using a roll-to-roll attachment device to form a composite film roll 1.

[0072] This step realizes the positioning of the to-be-coated area in the proton exchange membrane 200 through CCD visual detection winding correction, and the positioning accuracy is required to be ±0.05 mm; the thickness of the proton exchange membrane 200 roll is 8 μm±1 μm, the interfacial peeling force between the proton exchange membrane 200 and the back film is 0.006 N / mm; the side to be attached of the cathode positioning protective film 100 is coated with UV debonding glue, the adhesive thickness is 130±10 μm, and the initial adhesion characteristic is that the interfacial peeling force after 0.2 MPa roller pressing attachment with the proton exchange membrane 200 is 0.02 N / mm.

[0073] S2-B3. The composite film roll 1 is transported at a certain speed in the cathode coating station, and when the positioning sensor detects the edge of the active area cavity 101 of the cathode positioning protection film 100, the equipment drives the coating head to intermittently coat the CCM cathode on the film surface on the side to be coated at a specified length, and the coating range is larger than the size of the active area cavity 101 of the cathode positioning protection film 100.

[0074] In the above step S2-B3, the intermittent CCM cathode coating scheme is slot coating, the wet film thickness of the cathode slurry is about 180 μm, and the viscosity is 130±30 mPa·s.

[0075] S2-B4. After the roll coated with the cathode catalytic layer is dried by the oven, the composite film roll 2 is formed by winding, and the drying temperature is 80±2℃.

[0076] S2-B5. While the composite film roll 2 is stripped of the proton exchange membrane 200 back film, the second side of the proton exchange membrane 200 is roll-to-roll attached to the anode positioning protection film 100 through the attachment positioning hole 102 to form a composite film roll 3.

[0077] In this step S2-B5, the alignment accuracy of the active area cavities 101 on both sides of the proton exchange membrane 200 is required to be ±0.02 mm; the anode positioning protection film 100 to be attached on one side is coated with a heat loss adhesive, and the adhesive thickness is 30±5 μm. The initial adhesion property: after the 0.2 MPa, 25oC roll pressing attachment with the proton exchange membrane 200, the interfacial peeling force is 0.05 N / mm.

[0078] S2-B6. The cathode positioning protection film 100 in the composite film roll 3 is stripped by UV light activation.

[0079] S2-B7. The film roll is transported at a certain speed in the anode coating station, and when the positioning sensor detects the edge of the active area cavity 101 of the anode positioning protection film 100, the equipment drives the coating head to intermittently coat the CCM anode on the film surface on the side to be coated of the anode positioning protection film 100 at a specified length, and the coating range is larger than the size of the active area cavity 101 of the anode positioning protection film 100.

[0080] In this step S2-B7, the coating scheme is slot coating, the wet film thickness of the anode slurry is about 55 μm, and the viscosity is 35±15 mPa·s.

[0081] S2-B8. After the roll coated with the anode catalytic layer is dried at 55±2℃, the cathode side is attached to the cathode support back film and simultaneously wound to form a composite film roll 4.

[0082] In addition, when the proton exchange membrane 200 has high mechanical stability, the coating slurry also has specific process requirements, and the proton exchange membrane 200 cannot be affected by the slurry to swell and affect the quality of double-sided coating, the double-sided coating of the proton exchange membrane 200 can also be performed simultaneously or sequentially through a single coating device.

[0083] Specifically, in the third embodiment of the present application, the positioning protective film 100 includes a first positioning protective film 100-a and a second positioning protective film 100-b, and the PTFE protective film material belt is subjected to punching processing by a punching device to form a punching structure as shown in Figure 4 The punching structure includes double-strip active area cavities 101, a lamination positioning hole 102, and a coating guide mark 103; and step S2 includes:

[0084] S2-C1: laminating the first side of the commercialized proton exchange membrane 200 with the cathode positioning protective film 100 by using a roll-to-roll lamination device to form a composite film roll 1.

[0085] This step realizes the positioning of the to-be-coated area of the proton membrane by CCD visual detection winding correction, and the positioning accuracy is required to be ±0.05 mm; the thickness of the proton exchange membrane 200 roll is 25 μm±2 μm, the interface peeling force between the proton exchange membrane 200 and the back film is 0.005 N / mm; the to-be-laminated side of the cathode positioning protective film 100 is coated with a hot debonding adhesive, and the adhesive thickness is 23±2 μm, and the initial adhesion characteristic is: 0.2 MPa with the proton exchange membrane 200, 25 o The interface peeling force after C roller pressing lamination is 0.05 N / mm.

[0086] S2-C2: tearing off the back film of the proton exchange membrane 200 in the composite film roll 1, and simultaneously laminating the second side of the proton exchange membrane 200 with the anode positioning protective film 100 through the lamination positioning hole 102 by using a roll-to-roll lamination device to form a composite film roll 2.

[0087] In this step, the cathode positioning protective film 100 and the anode positioning protective film 100 are positioned by punching through the lamination positioning hole 102 and the positioning pin on the lamination roller to ensure that the positions of the active area cavities 101 on both sides of the proton exchange membrane 200 are aligned, and the alignment accuracy of the active area cavities 101 in the coating direction and the width direction of the positioning protective film 100 is required to be ±0.02 mm; the to-be-laminated side of the anode positioning protective film 100 is coated with a hot debonding adhesive, and the adhesive thickness is 23±2 μm, and the initial adhesion characteristic is: 0.2 MPa with the proton exchange membrane 200, 25

[0088] S2-C3: The composite film roll 2 is transmitted at a certain speed in the double-sided coating station, and when the coating head positioning sensor detects the coating guide mark 103 of the anode positioning protection film 100 and the cathode positioning protection film 100, intermittent coating is performed on the to-be-coated area on both sides of the proton exchange membrane 200, and the coating range should be larger than the size of the active area cavity 101, so as to form the anode catalyst layer and the cathode catalyst layer.

[0089] In the above step S2-C3, the coating scheme is double-sided slot coating, the wet film thickness of the cathode slurry is about 65 μm, the viscosity is 3000±200 mPa·s, the wet film thickness of the anode slurry is about 30 μm, and the viscosity is 90±30 mPa·s.

[0090] S2-C4: After the anode catalyst layer and the cathode catalyst layer are coated on the roll, the roll is dried at 80±2 o After drying, the coating in the active area cavity 101 is uniform and crack-free, and the roll is simultaneously attached to the first supporting back film 500 and the second supporting back film 600 and is synchronously rolled up during the rolling process, the first supporting back film 500 is located on the side of the anode catalyst layer away from the proton exchange membrane 200, and the second supporting back film 600 is located on the side of the cathode catalyst layer away from the proton exchange membrane 200.

[0091] It should be understood that in the above step S2-C3, intermittent coating can be performed on both sides of the proton exchange membrane 200 synchronously, or intermittent coating can be performed on both sides of the proton exchange membrane 200 sequentially, and the coating mode is not specifically limited in the present application.

[0092] Further, when the thickness and material of the positioning protection film 100 on the second side of the proton exchange membrane 200 do not affect the flatness and precision of the coating of the first catalyst layer 300, the film can be attached first and then coated; for example, in the fourth specific embodiment of the present application, the step S2 comprises:

[0093] S2-D1: The first positioning protection film 100-a is attached to the first side of the proton exchange membrane 200 in a roll-to-roll manner to form a composite film roll 1.

[0094] S2-D2: The back film of the proton exchange membrane 200 is torn off, and the second positioning protection film 100-b is attached to the second side of the proton exchange membrane 200 in a roll-to-roll manner to form a composite film roll 2.

[0095] S2-D3: Intermittent coating is performed on the first side of the proton exchange membrane 200 to form the first catalyst layer 300.

[0096] S2-D4: The first catalyst layer 300 is dried and rolled up, and at the same time, the first positioning protection film 100-a is peeled off to form a composite film roll 3.

[0097] S2-D5: Intermittently coating the second side of the proton exchange membrane 200 to form the second catalytic layer 400.

[0098] S2-D6: Drying the second catalytic layer 400, and simultaneously laminating and winding the first catalytic layer 300 and the second catalytic layer 400 with the first supporting back film 500 and the second supporting back film 600 to form a composite film roll 4, wherein the first supporting back film 500 is located on the side of the first catalytic layer 300 away from the proton exchange membrane 200, and the second supporting back film 600 is located on the side of the second catalytic layer 400 away from the proton exchange membrane 200.

[0099] In addition, according to the subsequent integration requirement of the CCM needing to be combined with the sealing frame, based on the difference in lamination force between different interfaces, the proton exchange membrane double-side catalytic layer coating method further includes a step S3 after step S2: sequentially tearing off the first supporting back film 500, the second supporting back film 600, the first positioning protective film 100-a and the second positioning protective film 100-b, and then roll pressing and laminating with the frame; the frame lamination can be carried out by pressure-sensitive lamination, hot melt adhesive lamination or photocuring lamination, etc. The interfacial peeling force between the frame and the film is required to be greater than 0.04 N / mm.

[0100] Based on the above steps, the process parameters are as follows: the peeling strength of the proton exchange membrane 200 and its back film is 0.004-0.025 N / mm, the swelling rate of the proton exchange membrane 200 is <10%; the positioning protective film 100 has a thermal shrinkage rate of <0.1% at 110 o C, so as to reduce the material deformation caused by the drying process and ensure the positioning accuracy; the thickness of the positioning protective film 100 is 10-200 μm, and the tolerance is less than or equal to 10 μm, which is selected according to the thickness of the slurry wet film and the stiffness of the material; the thickness of the cathode positioning protective film 100 and the anode positioning protective film 100 can be different; the slurry viscosity of the first catalytic layer 300 and the second catalytic layer 400 is 20-100000 mPa•s, so as to ensure that the slurry does not overflow between the gaps of the positioning protective film 100 during the coating process; the slurry drying temperature of the first catalytic layer 300 and the second catalytic layer 400 is 50-100 o C.

[0101] In addition, the application also discloses a positioning protective film for the above-mentioned proton exchange membrane double-side catalytic layer coating method, which has a periodic active area cavity and a periodic lamination positioning hole along the length direction.

[0102] When the positioning protection film is used, the positioning protection film has periodic fitting positioning holes along the length direction, the positioning precision of the positioning protection film on both sides of the proton exchange membrane is improved through the cooperation between the fitting positioning holes and the positioning pins on the fitting roller, the active area cavities on both sides of the positioning protection film have high alignment precision, the alignment precision of the first and second catalytic layers is effectively improved in the intermittent coating process, the alignment deviation of the catalytic layers on both sides of the proton exchange membrane is reduced, the possibility of chemical decay of the membrane electrode material is reduced, and the service life of the membrane electrode is prolonged.

[0103] It should be understood that the active area cavities 101 described above can be polygonal holes (for example, rectangular holes, rhombic holes), or notched rectangular holes, or any pre-set special-shaped holes, as long as the shape can meet the use requirements, and the shape belongs to the protection scope of the present application. Based on the pattern expansion of the active area cavities 101, the coating shape is expanded, the uneven distribution of reaction gas and liquid water caused by the rectangular structure of the CCM is reduced, the difference between the temperature and the current density of different areas is reduced, the service life of the membrane electrode is prolonged, and the consistency of the membrane electrode is improved. In addition, the active area cavities 101 described above can be single or multiple, and in actual application, the number of the active area cavities 101 can be adaptively adjusted according to the actual coating scheme. Optionally, the active area cavities 101 provided in the embodiments of the present application are multiple, and the multiple active area cavities are arranged side by side in the width direction of the positioning protection film, so that the catalytic layer is expanded from the traditional single long rectangular CCM to multiple notched rectangular CCMs, multiple rhombic CCMs or multiple polygonal CCMs, and the like, so as to effectively improve the uneven distribution of reaction gas and liquid water in the actual operation of the membrane electrode, and further improve the long-life operation capability of the membrane electrode product.

[0104] The terms "first" and "second" and the like in the description and claims of the present application and the above drawings are used to distinguish different objects, and are not used to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can include steps or units not listed.

[0105] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A proton exchange membrane double-sided catalytic layer coating method, characterized by, The method comprises the steps of: S1: performing a punching process on a protective film roll to form a positioning protective film, the positioning protective film having periodic active area cavities and periodic fitting positioning holes along its length direction; S2: fitting the positioning protective film on the first side and the second side of the proton exchange membrane, the positioning pins on the fitting roller are inserted into the fitting positioning holes, and intermittent coating is performed on the to-be-coated areas of the first side and the second side of the proton exchange membrane to form a first catalyst layer and a second catalyst layer, respectively.

2. The method for coating a proton exchange membrane double-sided catalytic layer according to claim 1, characterized by, The positioning protective film comprises a first positioning protective film and a second positioning protective film, and the step S2 comprises: S2-A1: roll-to-roll fitting the first positioning protective film with the first side of the proton exchange membrane; S2-A2: performing intermittent coating on the first side of the proton exchange membrane to form a first catalyst layer at the active area cavities of the first positioning protective film; S2-A3: drying the first catalyst layer and then winding it up; S2-A4: tearing off the back film of the proton exchange membrane, and roll-to-roll fitting the second positioning protective film with the second side of the proton exchange membrane; S2-A5: performing intermittent coating on the second side of the proton exchange membrane to form a second catalyst layer at the active area cavities of the second positioning protective film; S2-A6: drying the second catalyst layer, and simultaneously fitting the first catalyst layer and the second catalyst layer with a first supporting back film and a second supporting back film, and synchronously winding them up, wherein the first supporting back film is located on the side of the first catalyst layer away from the proton exchange membrane, and the second supporting back film is located on the side of the second catalyst layer away from the proton exchange membrane.

3. The method for coating a proton exchange membrane double-sided catalytic layer according to claim 2, characterized by, If the thickness of the first positioning protective film exceeds a thickness threshold, the steps S2-A5 and S2-A4 further comprise: S2-B: tearing off the first positioning protective film.

4. The method for coating a proton exchange membrane double-sided catalytic layer according to claim 1, characterized by, The positioning protective film comprises a first positioning protective film and a second positioning protective film, and the step S2 comprises: S2-C1: roll-to-roll fitting the first positioning protective film with the first side of the proton exchange membrane; S2-C2: tearing off the back film of the proton exchange membrane, and roll-to-roll fitting the second positioning protective film with the second side of the proton exchange membrane; S2-C3: performing intermittent coating on both sides of the proton exchange membrane to form a first catalyst layer and a second catalyst layer; S2-C4: drying the first catalyst layer and the second catalyst layer, and simultaneously fitting the first catalyst layer and the second catalyst layer with a first supporting back film and a second supporting back film, and synchronously winding them up, wherein the first supporting back film is located on the side of the first catalyst layer away from the proton exchange membrane, and the second supporting back film is located on the side of the second catalyst layer away from the proton exchange membrane.

5. The method for coating a proton exchange membrane double-sided catalytic layer according to claim 4, characterized by, In the step S2-C3, intermittent coating is synchronously performed on both sides of the proton exchange membrane, or intermittent coating is sequentially performed on both sides of the proton exchange membrane.

6. The method for coating a proton exchange membrane double-sided catalytic layer according to claim 1, characterized by, The positioning protective film comprises a first positioning protective film and a second positioning protective film, and the step S2 comprises: S2-D1: roll-to-roll fitting the first positioning protective film with the first side of the proton exchange membrane; S2-D2: tear off the back film of the proton exchange membrane, and roll-to-roll adhere the second positioning protection film to the second side of the proton exchange membrane; S2-D3: intermittently coat the first side of the proton exchange membrane to form a first catalytic layer; S2-D4: dry and wind the first catalytic layer, and meanwhile, peel off the first positioning protection film; S2-D5: intermittently coat the second side of the proton exchange membrane to form a second catalytic layer; S2-D6: dry the second catalytic layer, and simultaneously adhere the first catalytic layer and the second catalytic layer to the first supporting back film and the second supporting back film and wind them synchronously, wherein the first supporting back film is located on the side of the first catalytic layer away from the proton exchange membrane, and the second supporting back film is located on the side of the second catalytic layer away from the proton exchange membrane.

7. The method for coating a proton exchange membrane double-sided catalytic layer according to claim 2 or 4 or 5, characterized by, Further comprising a step S3 after step S2: after sequentially tearing off the first supporting back film, the second supporting back film, the first positioning protection film and the second positioning protection film, roll and adhere to the frame.

8. The method for coating a proton exchange membrane double-sided catalytic layer according to claim 1, characterized by, The active area cavity is a polygonal hole or a notched rectangular hole.

9. The method for coating a proton exchange membrane double-sided catalytic layer according to claim 1, characterized by, The positioning protection film comprises a plurality of active area cavities, and the plurality of active area cavities are arranged side by side in the width direction of the positioning protection film.

10. The proton exchange membrane double-side catalytic layer coating method according to any one of claims 1 to 6, claim 8 and claim 9, characterized in that, The positioning protective film has a thermal shrinkage rate of less than 0.1% at 110 o C, 5 min. The thickness of the positioning protection film is 10-200 μm, and the tolerance is less than or equal to 10 μm; The slurry viscosity of the first catalytic layer and the second catalytic layer is 20-100000 mPa·s; The slurry drying temperature of the first catalytic layer and the second catalytic layer is 50-100 o C.

11. A positioning protection film for use in the method of claim 1 to 10, characterized in that, The positioning protection film has periodic active area cavities and periodic adhesion positioning holes along the length direction of the positioning protection film, and the adhesion positioning holes are used for inserting and cooperating with positioning pins on an adhesion roller.

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