Double-sided coating device and coating method for hydrogen fuel cell membrane

Abstract

The invention relates to the technical field of continuous coating equipment, in particular to a hydrogen fuel cell membrane double-sided coating device and a coating method.The hydrogen fuel cell membrane double-sided coating device is characterized in that two annular release belt structures with independent large arc-shaped sections and vertical coating sections are adopted, drying units arranged on the inner sides of the vertical coating sections in a matched mode, and sectional rolling assemblies are adopted; the coating, drying and transferring processes of the catalyst layer are realized, and the dried solid catalyst layer is subjected to synchronous double-sided hot-pressing transferring in a vertical directional stable transferring space through a pressure profile which can be regulated and controlled in the height direction; the problems of poor catalyst layer transfer uniformity and insufficient interface bonding force caused by non-uniform pressure distribution, fixed contact time and unstable film path in a traditional horizontal rolling mode are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of continuous coating equipment technology, specifically to a double-sided coating device and coating method for hydrogen fuel cell membranes. Background Technology

[0002] As a highly efficient and clean energy conversion device, the performance of the membrane electrode assembly (MEA), a core component of hydrogen fuel cells, directly determines the cell's output power and lifespan. The proton exchange membrane (PEM) is a crucial component of the MEA, responsible for conducting protons and isolating gases. During the manufacturing process of the MEA, catalyst layers (typically containing noble metal catalysts such as platinum) need to be coated on both sides of the PEM to form an electrochemical reaction interface.

[0003] Currently, a widely used industrial process is the "release transfer method," which involves first coating and drying a catalyst slurry on a release carrier (such as a release membrane or release roller) to form a solid catalyst layer, and then transferring it onto a proton exchange membrane via hot pressing. This method aims to prevent the alcohol solvent in the catalyst slurry from directly contacting the proton exchange membrane, thereby preventing the perfluorosulfonic acid membrane from experiencing performance degradation, dimensional deformation, or defects due to solvent swelling.

[0004] Patent document publication number CN118486842B discloses a hydrogen energy membrane electrode coating machine. A main unwinding roller and a main take-up roller are movably mounted on the front of the mounting back plate, and a proton exchange membrane is wound around the main unwinding roller and the main take-up roller. A protective film is adhered to one side of the proton exchange membrane, with the side with the protective film attached being side B and the side without the protective film being side A. Two sets of symmetrically distributed transfer mechanisms are arranged on the front of the mounting back plate. In this hydrogen energy membrane electrode coating machine, after the protective film take-up roller removes the protective film from the proton exchange membrane, a catalytic layer is coated onto the transfer rollers on both sides of the proton exchange membrane through coating heads at corresponding positions. The catalytic layer is heated and dried by the heating element built into the transfer roller, simultaneously causing the alcohol solvent in the catalytic layer to evaporate. When the proton exchange membrane moves between the two sets of transfer rollers, the two sets of transfer rollers can transfer the dried catalytic layer to both sides of the proton exchange membrane.

[0005] The traditional release transfer coating device and method used in this coating machine have shortcomings in terms of transfer uniformity and interface quality. Roll-to-roll hot-press transfer typically relies on a pair of rigid or simply coated transfer rollers to extrude the film in a single operation. This "line contact" or "narrow surface contact" pressure application method makes it difficult to achieve a truly uniform pressure distribution in both the film width and travel direction. Uneven pressure can easily lead to incomplete adhesion between the catalyst layer and the proton exchange membrane, resulting in problems such as poor local transfer, microscopic voids at the interface, or weak bonding, thereby increasing the interfacial contact resistance and affecting proton conduction efficiency. Summary of the Invention

[0006] To address the problems existing in the prior art, a double-sided coating device and method for hydrogen fuel cell membranes are provided. By employing a ring-shaped release belt structure with two independent large arc segments and a vertical coating segment, combined with a drying unit located inside the vertical coating segment and a segmented roller pressing assembly, the catalyst layer coating, drying, and transfer processes are realized. The dried solid catalyst layer is simultaneously transferred by double-sided hot pressing in a vertically oriented stable transfer space through a pressure profile that can be adjusted along the height direction. This effectively solves the problems of poor catalyst layer transfer uniformity and insufficient interfacial bonding caused by uneven pressure distribution, fixed contact time, and unstable membrane path in the traditional horizontal roller pressing method.

[0007] To address the problems of existing technologies, this invention provides a double-sided coating device for hydrogen fuel cell membranes, comprising: two annular release belts symmetrically arranged and respectively carrying an anode catalyst layer and a cathode catalyst layer; each of the two annular release belts has a large arc-shaped segment and a vertical coating segment, the large arc-shaped segment being located upstream of the vertical coating segment; the vertical coating segments of the two annular release belts are parallel and opposite to each other to form a transfer space between them for the proton exchange membrane to pass through vertically; a coating head, disposed on the outer side of the large arc-shaped segment, for coating catalyst slurry onto the surface of the annular release belt; a drying unit, disposed on the inner side of the vertical coating segment, for drying the catalyst slurry on the surface of the annular release belt running to the vertical coating segment to form the catalyst layer; and a roller pressing assembly, disposed on the inner side of the vertical coating segment, for applying controllable pressure to the inner side of the vertical coating segment; the roller pressing assembly includes multiple independently controllable pressure rollers arranged vertically to form a preset pressure distribution profile in the height direction of the vertical coating segment.

[0008] Preferably, it further includes a frame and a large circular roller and a guide roller rotatably disposed in the frame; the annular release strip is sleeved on the large circular roller and the guide roller; the portion of the annular release strip located outside the large circular roller forms the large arc segment, and the portion of the annular release strip located between the large circular roller and the guide roller forms the vertical coating segment.

[0009] Preferably, it further includes a tension roller disposed in the frame; a sliding block is disposed on the side wall of the frame, the sliding block being slidably disposed on the frame along the adjustment direction of the tension roller; a tension spring is disposed on the frame, one end of the tension spring being connected to the sliding block and the other end being connected to the frame, so as to provide the sliding block with an elastic force that causes the tension roller to press against the inner side of the annular release strip; the end shaft of the tension roller passes through the sliding block and is rotatably connected to it.

[0010] Preferably, it further includes a drive motor and gears disposed on the end shafts of the two large circular rollers; the gears on the end shafts of the two large circular rollers mesh with each other; the output shaft of the drive motor is synchronously connected to the end shaft of one of the large circular rollers.

[0011] Preferably, the roller pressing assembly further includes: a mounting frame that passes between the two annular release strips; two laterally opposite mounting seats disposed in the mounting frame; the pressure rollers being rotatably disposed in their respective mounting seats; and an adjusting element provided at the outer end of the mounting frame extending to the annular release strip for synchronously adjusting the pressure applied by the two pressure rollers to the inner side of the annular release strip.

[0012] Preferably, the adjusting component includes: an adjusting plate, slidably disposed in the mounting frame along the width direction of the annular release strip; an adjusting screw, perpendicularly penetrating the side of the mounting frame and threadedly connected to the mounting frame, with its end rotatably connected to the center position of the adjusting plate; both ends of the adjusting plate extend to the ends of the corresponding mounting seats, and the ends of the adjusting plate and the ends of the mounting seats are slidably engaged by inclined surfaces; when the adjusting screw is rotated, the adjusting plate moves along the width direction of the annular release strip, and the inclined surface sliding engagement drives the two mounting seats to move towards or away from each other.

[0013] Preferably, a connecting post is provided on the back of each of the two mounting seats; the connecting post slides through the mounting frame; a limit ring is provided at the end of the connecting post; an elastic reset element is sleeved on the connecting post, the elastic reset element is located between the limit ring and the mounting frame, so that the end of the mounting seat always maintains a sliding fit with the end of the adjusting plate.

[0014] Preferably, the drying unit includes: a plurality of heating rods arranged along the vertical direction of the vertical coating section on the inner side of the vertical coating section; the ends of the heating rods are connected to the side wall of the mounting frame.

[0015] Preferably, the side wall of the mounting bracket is provided with a transversely extending connecting groove; the end of the heating rod is disposed in the connecting groove and its position can be adjusted along the connecting groove to change the distance between the heating rod and the vertical coating section.

[0016] A method for double-sided coating of a hydrogen fuel cell membrane, employing a double-sided coating apparatus for a hydrogen fuel cell membrane, includes the following steps:

[0017] Step 1: Drive the two annular release belts to run synchronously in a cycle, so that they pass through the coating, drying and transfer stations in sequence;

[0018] Step 2: On the outer side of the large arc segment, a catalyst slurry is coated onto the surface of the annular release belt that has traveled there through a coating head; subsequently, on the inner side of the vertical coating segment, the slurry is dried by a drying unit to form a solid catalyst layer on the annular release belt.

[0019] Step 3: The proton exchange membrane is brought vertically into the transfer space formed by the vertical coating section of the two annular release strips; controllable pressure is applied to the vertical coating section by the roller pressing assembly to simultaneously transfer the catalyst layer on the two annular release strips to both sides of the proton exchange membrane by hot pressing.

[0020] The advantages of this application compared to the prior art are:

[0021] This application utilizes a ring-shaped release belt structure with two independent large arc sections and a vertical coating section, along with a drying unit located inside the vertical coating section and a segmented roller pressing assembly, to achieve catalyst layer coating, drying, and transfer processes. The dried solid catalyst layer is simultaneously transferred by double-sided hot pressing in a vertically oriented, stable transfer space through a pressure profile adjustable along the height direction. Through the vertically arranged transfer space and programmable segmented roller pressing, a large-area uniform "surface contact" pressure is achieved, and the pressure curve can be flexibly optimized (such as inlet slow pressure, middle main pressure, and outlet depressurization), ensuring a tight bond between the catalyst layer and the proton exchange membrane interface, significantly reducing voids and poor contact, and lowering the interface resistance. Attached Figure Description

[0022] Figure 1 This is a perspective view of a hydrogen fuel cell membrane double-sided coating device according to the present invention.

[0023] Figure 2 This is a perspective sectional view of a hydrogen fuel cell membrane double-sided coating device according to the present invention.

[0024] Figure 3 This is a cross-sectional view of a hydrogen fuel cell membrane double-sided coating device according to the present invention.

[0025] Figure 4 yes Figure 3 A magnified view of part A.

[0026] Figure 5 yes Figure 3 A magnified view of section B.

[0027] Figure 6 This is a perspective view of the roller pressing assembly in a hydrogen fuel cell membrane double-sided coating device according to the present invention.

[0028] Figure 7 This is a top view of the roller pressing assembly in a hydrogen fuel cell membrane double-sided coating device according to the present invention.

[0029] Figure 8 This is a partial exploded perspective view of the roller pressing assembly in a hydrogen fuel cell membrane double-sided coating device according to the present invention.

[0030] Figure 9 yes Figure 8 A magnified view of a portion of point C.

[0031] Figure 10 This is a perspective view of the pressure roller and mounting base in a hydrogen fuel cell membrane double-sided coating device according to the present invention.

[0032] The diagram is labeled as follows: 1. Annular release belt; 11. Large arc section; 12. Vertical coating section; 2. Coating head; 3. Drying unit; 31. Heating rod; 4. Roller assembly; 41. Pressure roller; 42. Mounting frame; 421. Connecting groove; 43. Mounting base; 431. Connecting column; 432. Limiting ring; 433. Elastic reset element; 441. Adjusting plate; 442. Adjusting screw; 51. Frame; 52. Large circular roller; 53. Guide roller; 54. Tensioning roller; 55. Sliding block; 56. Tensioning spring; 57. Drive motor; 58. Gear; 71. Proton exchange membrane; 72. Catalyst slurry. Detailed Implementation

[0033] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0034] like Figures 1 to 5 As shown, a double-sided coating device for a hydrogen fuel cell membrane includes: two annular release strips 1, symmetrically arranged and respectively carrying an anode catalyst layer and a cathode catalyst layer; each of the two annular release strips 1 has a large arc-shaped segment 11 and a vertical coating segment 12, the large arc-shaped segment 11 being located upstream of the vertical coating segment 12; the vertical coating segments 12 of the two annular release strips 1 are parallel and opposite to each other to form a transfer space therebetween for a proton exchange membrane 71 to pass through vertically; a coating head 2, disposed outside the large arc-shaped segment 11, for coating the annular release strips 1. The surface of the strip 1 is coated with catalyst slurry 72; a drying unit 3 is disposed inside the vertical coating section 12 and is used to dry the catalyst slurry 72 on the surface of the annular release strip running to the vertical coating section to form the catalyst layer; a roller pressing assembly 4 is disposed inside the vertical coating section 12 and is used to apply controllable pressure to the inside of the vertical coating section 12; the roller pressing assembly 4 includes a plurality of pressure rollers 41 arranged in the vertical direction and independently controllable, so as to form a preset pressure distribution profile in the height direction of the vertical coating section 12.

[0035] Two symmetrically arranged annular release belts 1 serve as carriers for the catalyst layer. Each annular release belt 1 includes a large arc-shaped segment 11 and a vertical coating segment 12, with the large arc-shaped segment 11 located upstream of the vertical coating segment 12. The vertical coating segments 12 of the two annular release belts 1 are parallel to each other and arranged opposite to each other, together forming a transfer space through which the proton exchange membrane 71 passes vertically. The device is also equipped with a coating head 2, a drying unit 3, and a roller pressing assembly 4. The coating head 2 is located on the outside of the large arc-shaped segment 11 and is responsible for coating the catalyst slurry 72 onto the surface of the annular release belt 1. The drying unit 3 is integrated on the inside of the vertical coating segment 12 and is used to dry the catalyst slurry 72 that has traveled to the surface of the annular release belt in the vertical coating segment, thereby forming a solid catalyst layer. The roller pressing assembly 4 is also located on the inside of the vertical coating segment 12, and its function is to apply controllable and uniform pressure to the inside of the vertical coating segment 12. Specifically, the roller pressing assembly 4 includes multiple pressure rollers 41 units arranged vertically and independently controllable, thereby enabling the precise formation of a preset pressure distribution profile along the entire height of the vertical coating section 12.

[0036] The working process is as follows: First, two annular release belts 1 are driven to circulate synchronously, passing sequentially through the coating station. When the annular release belt 1 reaches the large arc section 11, the coating head 2 uniformly coats the catalyst slurry 72 onto its surface. Subsequently, the annular release belt 1 carrying the wet slurry enters the vertical coating section 12. At this time, the drying unit 3 integrated inside this section is activated to efficiently and uniformly dry the slurry, solidifying it into a structurally stable catalyst layer. Simultaneously, the proton exchange membrane 71 is guided vertically into the transfer space enclosed by the vertical coating section 12 of the two annular release belts 1. When the annular release belt 1 carrying the dried catalyst layer contacts the proton exchange membrane 71 in the transfer space, the outer roller pressing assembly 4 is activated. By independently controlling the pressure of multiple pressure roller units 41, an optimized pressure profile that can be gradient-varied along the membrane travel direction (vertical direction) is applied to the contact surface between the catalyst layer and the proton exchange membrane 71. Under the combined action of pressure and possibly heating, the dry catalyst layer is synchronously and completely transferred from the two annular release bands 1 to both sides of the proton exchange membrane 71 by hot pressing, forming a high-quality membrane electrode.

[0037] like Figures 3 to 10 As shown, it also includes a frame 51 and a large circular roller 52 and a guide roller 53 rotatably disposed in the frame 51; the annular release strip 1 is sleeved on the large circular roller 52 and the guide roller 53; the portion of the annular release strip 1 located outside the large circular roller 52 forms the large arc segment 11, and the portion of the annular release strip 1 located between the large circular roller 52 and the guide roller 53 forms the vertical coating segment 12.

[0038] An annular release belt 1 is fitted onto the large circular roller 52 and the guide roller 53, forming a specific running path through their positioning and support. The portion of the annular release belt 1 located outside the large circular roller 52 naturally forms the large arc-shaped segment 11 because it conforms to the arc-shaped surface of the large circular roller 52. The portion of the annular release belt 1 located between the large circular roller 52 and the guide roller 53 remains straight under tension, forming the vertical coating segment 12. Furthermore, the device is equipped with a tension roller 54, which abuts against the inner side of the annular release belt 1 and applies continuous tension, ensuring that the annular release belt 1 maintains a preset tension and flatness throughout operation, thereby providing a stable and reliable carrier foundation for coating, drying, and transfer processes.

[0039] The large circular roller 52, as the main driving and supporting component, rotates to drive the annular release belt 1 in a cyclical motion. The large diameter design of the large circular roller 52 not only provides a smooth transition curvature for the large arc segment 11, avoiding bending damage to the drying catalyst layer, but also facilitates stable slurry coating on the large arc surface by the coating head 2. The guide roller 53 precisely determines the starting position and direction of the vertical coating segment 12, ensuring that this segment is strictly parallel to the running path of the proton exchange membrane 71. The configuration of the tension roller 54 is crucial; it applies adjustable or constant elastic tension from the inner side (i.e., the non-working surface) of the annular release belt 1, dynamically compensating for thermal expansion, creep, or slight deformation that may occur in the annular release belt 1 during thermal cycling, thereby maintaining the straightness and spatial positioning accuracy of the vertical coating segment 12. The combined structure of "large circular roller 52-guide roller 53-tension roller 54" together ensures the precise path and smooth operation of the annular release belt 1, creating a repeatable and highly stable mechanical environment for the aforementioned coating, drying and roll transfer processes.

[0040] like Figure 1 As shown, it also includes a tension roller 54 disposed in the frame 51; a sliding block 55 is disposed on the side wall of the frame 51, the sliding block 55 being slidably disposed on the frame 51 along the adjustment direction of the tension roller 54; a tension spring 56 is disposed on the frame 51, one end of the tension spring 56 being connected to the sliding block 55 and the other end being connected to the frame 51, so as to provide the sliding block 55 with an elastic force that causes the tension roller 54 to press the inner side of the annular release belt 1; the end shaft of the tension roller 54 passes through the sliding block 55 and is rotatably connected to it.

[0041] To achieve adaptive tension adjustment, a sliding block 55 is provided on the side wall of the frame 51. The sliding block 55 can smoothly slide on the frame 51 along a preset adjustment direction (usually perpendicular to the plane of the annular release belt 1 or along the tension application direction). A tension spring 56 is provided between the frame 51 and the sliding block 55. One end of the tension spring 56 is connected to the sliding block 55, and the other end is fixed to the frame 51. The tension spring 56 is pre-compressed or pre-stretched, thereby continuously applying an elastic force to the sliding block 55. The direction of this force always drives the sliding block 55 (along with the tension roller 54 on it) to press against the inner side of the annular release belt 1. The end shaft of the tension roller 54 passes through the sliding block 55 and forms a rotatable connection with it, so that the tension roller 54 can rotate freely to reduce friction and can also move as a whole with the sliding block 55 to perform the tensioning function.

[0042] When the annular release belt 1 lengthens due to thermal expansion during operation, or when the tension tends to decrease due to factors such as material creep or temperature fluctuations, the pre-tensioned tension spring 56 immediately pushes the sliding block 55 and the tension roller 54 to move inwards towards the annular release belt 1, further "tightening" the annular release belt 1 to compensate for its increased length, thereby restoring and maintaining the preset tension value. Conversely, if the annular release belt 1 temporarily contracts for some reason, the tension spring 56 allows the sliding block 55 to rebound appropriately under the reaction force, avoiding excessive tension. The entire process is dynamic and continuous, requiring no intervention from external sensors or actuators. The rotating connection design of the tension roller 54 ensures that it makes rolling contact with the inner surface of the moving annular release belt 1, with minimal friction, ensuring efficient tension transmission while avoiding potential scratches on the surface of the annular release belt 1.

[0043] like Figure 1 and Figure 2 As shown, it also includes a drive motor 57 and gears 58 disposed on the end shafts of the two large rollers 52; the gears 58 on the end shafts of the two large rollers 52 mesh with each other; the output shaft of the drive motor 57 is synchronously connected to the end shaft of one of the large rollers 52.

[0044] When the drive motor 57 starts, its power is directly transmitted to the large circular roller 52 connected to it (which can be called the active large circular roller 52), driving the roller to rotate. Since the end shafts of the two large circular rollers 52 are rigidly connected through meshing gears 58, the rotational motion of the active large circular roller 52 is precisely and synchronously transmitted to the other large circular roller 52 (the driven large circular roller 52) in a one-to-one ratio. This ensures that the rotational speed and phase of the two large circular rollers 52 are always completely consistent. The rotation of the large circular roller 52 directly drives the two annular release belts 1 sleeved on it to perform cyclical motion. Since the path of the annular release belt 1 is determined by the large circular roller 52 and the guide roller 53, and a constant tension is maintained through the aforementioned tensioning mechanism, the synchronous drive of the gears 58 fundamentally ensures that the two annular release belts 1 have exactly the same linear velocity and direction of motion in their respective vertical coating sections 12. This provides the most fundamental mechanical synchronization guarantee for the synchronous coating and drying of the catalyst slurry 72 on the two belts, as well as the synchronous and aligned double-sided hot-pressing transfer with the proton exchange membrane 71.

[0045] like Figure 3 , Figure 4 and Figure 8 As shown, the roller pressing assembly 4 further includes: a mounting frame 42 that passes between the two annular release belts 1; two laterally opposite mounting seats 43 disposed in the mounting frame 42; and the pressure rollers 41 that are rotatably disposed in the corresponding mounting seats 43. The mounting frame 42 extends to the outer end of the annular release belt 1 and is provided with an adjusting member for synchronously adjusting the pressure applied by the two pressure rollers 41 to the inner side of the annular release belt 1.

[0046] Mounting bracket 42 serves as the rigid foundation of the entire roller pressing assembly 4, fixed to the frame 51. Its design, passing between the annular release belts 1, allows the two mounting seats 43 to be precisely aligned with the vertical coating sections 12 of the two annular release belts 1. Each pressure roller 41, mounted within its seat, has its roller surface in contact with the inner non-working surface of the annular release belt 1. When pressure needs to be applied through the roller pressing assembly 4, the adjusting mechanism is operated. The movement of the adjusting mechanism synchronously drives the two mounting seats 43 to move towards each other in a direction perpendicular to the plane of the annular release belt 1 (usually horizontal). Since all pressure rollers 41 are mounted on their respective mounting seats 43, this movement synchronously changes the contact pressure between all pressure rollers 41 and the inner surface of the annular release belt 1. This achieves a global, synchronous setting of the pressure level on the two annular release belts 1. Based on this, the independent control of each pressure roller 41 unit is responsible for fine-tuning and programming the pressure profile along the vertical direction (film travel direction) based on the global pressure, to meet different pressure requirements at the inlet, middle, and outlet.

[0047] like Figure 6 and Figure 7As shown, the adjusting component includes: an adjusting plate 441, which is slidably disposed in the mounting frame 42 along the width direction of the annular release strip 1; an adjusting screw 442, which vertically passes through the side of the mounting frame 42 and is threadedly connected to the mounting frame 42, and its end is rotatably connected to the center position of the adjusting plate 441; both ends of the adjusting plate 441 extend to the ends of the mounting seats 43 on the corresponding sides, and the ends of the adjusting plate 441 and the ends of the mounting seats 43 are slidably engaged by inclined surfaces; when the adjusting screw 442 is rotated, the adjusting plate 441 moves along the width direction of the annular release strip 1, and the two mounting seats 43 move towards each other or away from each other through the inclined surface sliding engagement.

[0048] When it is necessary to adjust the pressure of the pressure roller 41 on the annular release belt 1, the operator rotates the adjusting screw 442. Since the adjusting screw 442 is threadedly connected to the mounting bracket 42, the rotational motion is converted into axial movement of the screw itself. The axial movement of the screw pushes or pulls the adjusting plate 441, which is rotatably connected to it. Because the adjusting plate 441 is restricted to sliding only along the width direction of the annular release belt 1, the axial movement of the screw is directly converted into precise horizontal displacement of the adjusting plate 441.

[0049] When the adjusting plate 441 moves horizontally, the inclined surfaces at both ends of it will slide relative to the mating inclined surfaces at the ends of the mounting base 43. This inclined surface mating decomposes the horizontal movement of the adjusting plate 441 into a force perpendicular to the inclined surface. The vertical component of this force directly pushes the two mounting bases 43 to move in a direction perpendicular to the plane of the annular release belt 1 (i.e., towards each other or away from each other).

[0050] When the rotating screw moves the adjusting plate 441 towards the center, the inclined plane drives the two mounting seats 43 to move towards each other, pressing the annular release belt 1 and increasing the pressure. Reverse rotation of the screw moves the adjusting plate 441 outward. Under the action of the reset mechanism (such as the elastic reset element 433 described later) or the tension of the annular release belt 1 itself, the two mounting seats 43 move away from each other, reducing the pressure. The entire process is controlled by a single, centralized screw operation, allowing for stepless, synchronous, and linear adjustment of the positions of the two mounting seats 43 (and all pressure rollers 41), thus achieving precise and synchronous pressure setting.

[0051] like Figure 6 and Figure 7 As shown, each of the two mounting bases 43 has a connecting post 431 on its back; the connecting post 431 slides through the mounting frame 42; a limit ring 432 is provided at the end of the connecting post 431; an elastic reset element 433 is sleeved on the connecting post 431, and the elastic reset element 433 is located between the limit ring 432 and the mounting frame 42, so that the end of the mounting base 43 always maintains a sliding fit with the end of the adjusting plate 441.

[0052] The elastic reset element 433 is in a pre-compressed state, and its elastic force always acts on the connecting post 431 through the limiting ring 432, attempting to pull or push the connecting post 431 and its connected mounting seat 43 towards the outside of the mounting bracket 42. This elastic force is opposite to the direction in which the adjusting plate 441 pushes the mounting seat 43 towards the opposite direction (applying pressure) through the inclined surface.

[0053] First, ensuring contact: This elasticity ensures that no matter what position the adjusting plate 441 is in, the inclined structure at the end of the mounting base 43 will always be in close contact with the mating inclined surface at the end of the adjusting plate 441 under the continuous action of the elastic reset element 433, eliminating any backlash caused by machining gaps or minor deformations.

[0054] When the adjusting screw 442 is rotated in the opposite direction to move the adjusting plate 441 outward and reduce the pressure, it is the force of the elastic reset element 433 that actively pulls the two mounting seats 43 apart, so that they closely follow the movement of the adjusting plate 441, thereby achieving linear and lag-free pressure release.

[0055] Second, it provides preload and buffer: the elasticity provides a basic preload for the entire pressure regulation system, so that the pressure regulation has a clear mechanical starting point and good linear response from "zero".

[0056] At the same time, the elastic element can also absorb the minor vibrations or impacts that may be generated during equipment operation, preventing them from being directly transmitted to the pressure roller 41 and the annular release belt 1, thus playing a role in stabilizing the pressure.

[0057] like Figure 2 and Figure 3 As shown, the drying unit 3 includes: a plurality of heating rods 31 arranged along the vertical direction of the vertical coating section 12 on the inner side of the vertical coating section 12; the ends of the heating rods 31 are connected to the side wall of the mounting frame 42.

[0058] The core function of the drying unit 3 is to provide rapid and uniform heat energy to evaporate the solvent after the catalyst slurry 72 enters the vertical coating section 12 along the annular release belt 1, thus solidifying it into a catalyst layer. Multiple heating rods 31 are arranged vertically to cover the entire effective coating height.

[0059] The heating rod 31 is placed inside the vertical coating section 12, so that the heat can be directly radiated or conducted to the back side (non-coated surface) of the annular release belt 1 that is running there. Through the heat conduction of the annular release belt 1, the wet slurry attached to the outside (working surface) of the annular release belt 1 is heated and dried efficiently and uniformly.

[0060] Since the annular release belt 1 is usually made of a thermally conductive metal material, this "back heating" method has lower thermal resistance and higher thermal efficiency compared to hot air drying from above the slurry. It also reduces the disturbance of airflow on the wet film surface, which is more conducive to forming a smooth dried coating.

[0061] The end of the heating rod 31 is fixed to the side wall of the mounting bracket 42 shared with the roller pressing assembly 4, which ensures that the spatial position of the heating rod 31 array is strictly parallel to the vertical coating section 12 and the distance is constant, thereby ensuring the high uniformity and repeatability of the heat field distribution in the entire drying area.

[0062] like Figure 6 As shown, the side wall of the mounting bracket 42 is provided with a transversely extending connecting groove 421; the end of the heating rod 31 is disposed in the connecting groove 421 and its position can be adjusted along the connecting groove 421 to change the distance between the heating rod 31 and the vertical coating section 12.

[0063] At least one laterally extending connecting groove 421 is provided on the side wall of the mounting bracket 42. The end of the heating rod 31 (typically a fixed end or a support end) is disposed in the connecting groove 421. The design of the connecting groove 421 allows the end of the heating rod 31 to slide and be fixed within the groove along its extending direction (i.e., laterally), thereby allowing adjustment of the overall position of the heating rod 31. Through this adjustment, the vertical distance between the array of heating rods 31 and the inner surface of the vertical coating section 12 of the annular release tape 1 can be changed.

[0064] A method for double-sided coating of a hydrogen fuel cell membrane, employing a double-sided coating apparatus for a hydrogen fuel cell membrane, includes the following steps:

[0065] Step 1: Drive the two annular release belts 1 to run synchronously in a cycle, so that they pass through the coating, drying and transfer stations in sequence;

[0066] Step 2: On the outer side of the large arc segment 11, the catalyst slurry 72 is coated onto the surface of the annular release belt 1 that has moved there through the coating head 2; then, on the inner side of the vertical coating segment 12, the slurry is dried by the drying unit 3 to form a solid catalyst layer on the annular release belt 1.

[0067] Step 3: The proton exchange membrane 71 is brought vertically into the transfer space formed by the vertical coating section 12 of the two annular release belts 1; the roller pressing assembly 4 applies controllable pressure to the vertical coating section 12 to simultaneously transfer the catalyst layer on the two annular release belts 1 to both sides of the proton exchange membrane 71 by hot pressing.

[0068] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A double-sided coating apparatus for hydrogen fuel cell membranes, characterized in that, include: Two annular release strips are symmetrically arranged and respectively carry the anode catalyst layer and the cathode catalyst layer; each annular release strip has a large arc segment and a vertical coating segment, the large arc segment being located upstream of the vertical coating segment; the vertical coating segments of the two annular release strips are parallel to each other to form a transfer space between them for the proton exchange membrane to pass through vertically. A coating head, located on the outer side of the large arc segment, is used to coat the catalyst slurry onto the surface of the annular release strip; A drying unit is located inside the vertical coating section and is used to dry the catalyst slurry on the surface of the annular release belt running to the vertical coating section to form the catalyst layer. A roller pressing assembly is disposed on the inner side of the vertical coating section and is used to apply controllable pressure to the inner side of the vertical coating section; the roller pressing assembly includes a plurality of pressure rollers arranged in the vertical direction and independently controllable, so as to form a preset pressure distribution profile in the height direction of the vertical coating section.

2. The hydrogen fuel cell membrane double-sided coating device according to claim 1, characterized in that, It also includes a frame and a large circular roller and a guide roller that are rotatably mounted in the frame; The annular release belt is sleeved on the large circular roller and the guide roller; The annular release strip portion located on the outer side of the large circular roller forms the large arc-shaped section, and the annular release strip portion located between the large circular roller and the guide roller forms the vertical coating section.

3. The hydrogen fuel cell membrane double-sided coating device according to claim 2, characterized in that, It also includes tension rollers installed in the frame; The side wall of the frame is provided with a sliding block, which is slidably mounted on the frame along the adjustment direction of the tension roller; A tension spring is provided on the frame. One end of the tension spring is connected to the sliding block, and the other end is connected to the frame to provide an elastic force to the sliding block so that the tension roller presses the inner side of the annular release belt. The end shaft of the tension roller passes through the sliding block and is rotatably connected to it.

4. A double-sided coating apparatus for a hydrogen fuel cell membrane according to claim 2 or 3, characterized in that, It also includes a drive motor and gears mounted on the shafts at the ends of the two large circular rollers; The gears on the end shafts of the two large circular rollers mesh with each other; The output shaft of the drive motor is synchronously connected to the end shaft of one of the large circular rollers.

5. A double-sided coating apparatus for a hydrogen fuel cell membrane according to any one of claims 1-3, characterized in that, The rolling assembly also includes: The mounting bracket passes between the two annular release strips; Two horizontally opposite mounting bases are disposed in the mounting frame; The pressure rollers are rotatably mounted in their respective mounting seats; The mounting frame extends to the outer end of the annular release belt and is equipped with an adjusting element for synchronously adjusting the pressure applied to the inner side of the annular release belt by the two pressure rollers.

6. The hydrogen fuel cell membrane double-sided coating apparatus according to claim 5, characterized in that, The adjusting element includes: An adjusting plate is slidably disposed in the mounting frame along the width direction of the annular release strip; An adjusting screw passes vertically through the side of the mounting bracket and is threadedly connected to the mounting bracket, with its end rotatably connected to the center position of the adjusting plate; The two ends of the adjustment plate extend to the ends of the mounting base on the corresponding sides, and the ends of the adjustment plate and the ends of the mounting base slide together via inclined surfaces. When the adjusting screw is rotated, the adjusting plate moves along the width direction of the annular release strip, and the two mounting seats move towards each other or away from each other through the inclined sliding engagement.

7. The hydrogen fuel cell membrane double-sided coating apparatus according to claim 6, characterized in that, Both mounting bases have connecting posts on their back sides; The connecting column slides through the mounting frame; A limit ring is provided at the end of the connecting column; An elastic reset element is sleeved on the connecting column. The elastic reset element is located between the limiting ring and the mounting bracket so that the end of the mounting base always maintains a sliding fit with the end of the adjusting plate.

8. The double-sided coating apparatus for hydrogen fuel cell membranes according to claim 5, characterized in that, The drying unit includes: Multiple heating rods are arranged along the vertical direction of the vertical coating section on the inner side of the vertical coating section; The end of the heating rod is connected to the side wall of the mounting bracket.

9. The hydrogen fuel cell membrane double-sided coating apparatus according to claim 8, characterized in that, The side wall of the mounting bracket is provided with a transversely extending connecting groove; The end of the heating rod is disposed in the connecting groove, and its position can be adjusted along the connecting groove to change the distance between the heating rod and the vertical coating section.

10. A method for double-sided coating of a hydrogen fuel cell membrane, characterized in that, The hydrogen fuel cell membrane double-sided coating apparatus according to any one of claims 1-3 includes the following steps: Step 1: Drive the two annular release belts to run synchronously in a cycle, so that they pass through the coating, drying and transfer stations in sequence; Step 2: On the outer side of the large arc segment, a catalyst slurry is coated onto the surface of the annular release belt that has traveled there through a coating head; subsequently, on the inner side of the vertical coating segment, the slurry is dried by a drying unit to form a solid catalyst layer on the annular release belt. Step 3: The proton exchange membrane is brought vertically into the transfer space formed by the vertical coating section of the two annular release strips; controllable pressure is applied to the vertical coating section by the roller pressing assembly to simultaneously transfer the catalyst layer on the two annular release strips to both sides of the proton exchange membrane by hot pressing.

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