Double hollow column high curvature electrolytic cell

Abstract

The application provides a double hollow column high-curvature electrolytic cell, which comprises a double hollow column body and a connecting assembly for connecting the double hollow column body; the double hollow column body comprises a first hollow column body for forming an anode reaction chamber and a second hollow column body for forming a cathode reaction chamber, and first and second spiral electrolytic cells are arranged on column walls of the first and second hollow column bodies respectively; through the specific arrangement of the spiral electrolytic cells, a turbulent flow effect is formed when the electrolyte flows, the separation of gas bubbles from the catalyst surface is accelerated, the mass transfer efficiency is greatly improved compared with a traditional static system, and the electrochemical reaction rate is also improved.

Description

Technical Field

[0001] This application relates to the field of electrochemical reaction equipment technology, and in particular to a double hollow column high curvature electrolytic cell. Background Technology

[0002] An electrolyzer is a core piece of equipment that uses direct current to drive the directional migration of ions in an electrolyte solution, causing oxidation-reduction reactions at the anode and cathode respectively, thereby realizing the transformation, decomposition, and separation of chemical substances. Its performance directly determines the process efficiency and cost in fields such as basic chemical engineering, green hydrogen production, metallurgy, and environmental protection.

[0003] However, existing electrolyzer technology still has many technical shortcomings that urgently need to be addressed. These shortcomings directly restrict the efficiency of electrocatalytic reactions and the overall performance of the equipment, as follows:

[0004] ① Low mass transfer efficiency and prominent bubble accumulation problem: Traditional electrolyzers mostly adopt planar electrode structures and static electrolyte systems, making it difficult to create effective disturbances in the electrolyte flow. Bubbles generated in the electrocatalytic reaction tend to accumulate at the catalyst-electrolyte interface, hindering the contact between the electrolyte and the active sites of the catalyst, reducing the effective reaction area, and leading to problems such as poor reaction selectivity, high overpotential, and low reaction efficiency.

[0005] ② High electrode cost and insufficient specific surface area: The electrode support structure of existing electrolyzers (such as solid titanium bipolar plates) is not only expensive in terms of material cost, but the solid structure also cannot provide sufficient mass transfer channels, which is not conducive to electrolyte penetration and gas diffusion. At the same time, the specific surface area of ​​planar electrodes is limited, resulting in low catalyst loading and utilization, which further limits the electrocatalytic reaction rate and makes it difficult to meet the dual requirements of "high efficiency and low cost" for industrial production.

[0006] Therefore, there is an urgent need to design an electrolyzer that can overcome the limitations of traditional structures and solve the problems of "low mass transfer efficiency, high cost, and bubble accumulation" to meet the industrial demand for efficient and low-cost electrochemical reaction equipment. Summary of the Invention

[0007] The technical problem to be solved by this invention is to address the low mass transfer efficiency and low electrocatalytic reaction rate of traditional planar electrode structures. This invention provides a double hollow column high curvature electrolyzer, which achieves the beneficial effects of improving mass transfer efficiency and reaction rate through optimized structural design.

[0008] To achieve the above objectives, this application provides a double hollow column high curvature electrolytic cell, including double hollow columns and a connecting assembly for connecting the double hollow columns;

[0009] The double hollow column includes a first hollow column for forming an anode reaction chamber and a second hollow column for forming a cathode reaction chamber. The first hollow column and the second hollow column are respectively provided with a first spiral electrolytic cell and a second spiral electrolytic cell on their column walls.

[0010] The connecting assembly includes a left connecting structure connected to the first spiral electrolyzer, a right connecting structure connected to the second spiral electrolyzer, and a proton exchange membrane sandwiched between the left connecting structure and the right connecting structure.

[0011] In another preferred embodiment, the anode reaction chamber includes, from the outside to the inside, an insulating shell, a sealing gasket, a first spiral electrolytic cell, carbon fiber cloth, a microporous breathable membrane, and a perforated insulating core, wherein the perforated insulating core encloses the hollow region of the first hollow column; the cathode reaction chamber has the same installation structure as the anode reaction chamber.

[0012] In another preferred embodiment, the hollow area is a reaction gas storage and emission chamber, and the exhaust port of the reaction gas storage and emission chamber is connected to a vacuum pump.

[0013] In another preferred embodiment, both the first spiral electrolytic cell and the second spiral electrolytic cell are provided with connector ports for connecting to an external power source.

[0014] In another preferred embodiment, the left connecting structure and the right connecting structure are mirror surfaces of each other; the left connecting structure and the right connecting structure are fixedly connected by a mortise and tenon joint.

[0015] In another preferred embodiment, both the left connecting structure and the right connecting structure have hollowed-out arc-shaped spaces between their layers. The height of the hollowed-out arc-shaped spaces is consistent with the height of a single spiral of the first spiral electrolytic cell and the second spiral electrolytic cell, respectively, so that the first spiral electrolytic cell and the second spiral electrolytic cell are closely fitted with the hollowed-out arc-shaped spaces.

[0016] In another preferred embodiment, a spiral groove is formed between the inner side of the first spiral electrolytic cell and the outer side of the carbon fiber cloth, and the spiral groove serves as an electrolyte flow channel;

[0017] The insulating shell has an electrolyte inlet at the upper end and an electrolyte outlet at the lower end. The electrolyte enters the spiral groove through the electrolyte inlet and is discharged through the electrolyte outlet.

[0018] In another preferred embodiment, the surface of the carbon fiber cloth in contact with the electrolyte is coated with a catalyst coating, and the catalyst coating, together with the electrolyte and the first spiral electrolytic cell, constitutes an electrocatalytic reaction interface.

[0019] In another preferred embodiment, the first spiral electrolytic cell and the second spiral electrolytic cell are made of conductive carbon material.

[0020] In another preferred embodiment, the outer wall of the perforated insulating core is provided with protrusions, which are in close contact with the inner side of the microporous breathable membrane.

[0021] The top diameter of the protrusion is smaller than the gap between the single filaments of the carbon fiber cloth, the protrusion length of the protrusion is ≤ 80% of the thickness of the carbon fiber cloth, and the top is a spherical blunt head.

[0022] The protrusions extend into the carbon fiber cloth but do not penetrate the microporous breathable membrane, thus achieving an interference fit between the carbon fiber cloth and the microporous breathable membrane.

[0023] The beneficial effects of this application are as follows:

[0024] An embodiment of this application provides a double-hollow-column high-curvature electrolyzer, which includes double hollow columns and a connecting assembly for connecting the double hollow columns. The double hollow columns include a first hollow column for forming an anode reaction chamber and a second hollow column for forming a cathode reaction chamber. A first spiral electrolyzer and a second spiral electrolyzer are respectively arranged on the column walls of the first hollow column and the second hollow column. The specific arrangement of the spiral electrolyzer causes a turbulent effect (Dean vortex) to be formed when the electrolyte flows, which accelerates the separation of bubbles from the catalyst surface, greatly improves the mass transfer efficiency compared with the traditional static system, and at the same time improves the electrochemical reaction rate.

[0025] Furthermore, the first and second spiral electrolytic cells are connected and fixed through a connecting assembly formed by the left and right connecting structures. A proton exchange membrane is placed between the left and right connecting structures to separate the anode and cathode reaction chambers while allowing selective proton permeation. This enables proton transfer in the electrochemical reaction, prevents mixing of products at both electrodes, and ensures the directional conduction of the electrolysis reaction. The spiral electrolytic cell of this application overcomes the limitations of traditional planar electrode structures and solves the problem of low mass transfer efficiency caused by bubble accumulation in existing traditional structures. Attached Figure Description

[0026] The above and other features, advantages, and aspects of the embodiments of this application will become more apparent from the accompanying drawings and the following detailed description. The following drawings are provided to further understand this application, form part of this application, and are intended only to illustrate and explain the invention, and are not intended to limit the scope of the invention. In the drawings:

[0027] Figure 1 This is a schematic cross-sectional view of the double hollow column high curvature electrolytic cell according to an embodiment of this application. Figure 1 ;

[0028] Figure 2 This is a schematic cross-sectional view of the double hollow column high curvature electrolytic cell according to an embodiment of this application. Figure 2 ;

[0029] Figure 3 This is a perspective view of the first spiral electrolytic cell and the second spiral electrolytic cell according to embodiments of this application;

[0030] Figure 4 This is a top view of the double hollow column high curvature electrolytic cell according to an embodiment of this application;

[0031] Figure 5 This is a schematic diagram showing the hollowed-out arc-shaped space of the left connecting structure of the connecting component in the embodiments of this application;

[0032] Figure 6 This is a schematic diagram of the structure of the left and right connection structures of the connection component in the embodiment of this application.

[0033] Figure 7 This is a schematic diagram of the velocity distribution of the liquid flowing through the electrolyte channel in an embodiment of this application.

[0034] Figure label:

[0035] 1. Anode reaction chamber; 2. Cathode reaction chamber; 100. First hollow column; 200. Second hollow column; 3. Proton exchange membrane; 4. Insulating shell; 51. First spiral electrolytic cell; 52. Second spiral electrolytic cell; 6. Carbon fiber cloth; 7. Microporous breathable membrane; 8. Perforated insulating core; 9. Sealing gasket; 10. Connecting assembly; 10-1. Left connecting structure; 10-2. Right connecting structure; 10-3. Hollowed-out arc-shaped space; 11. Vacuum pump; 12. Electrolyte inlet; 13. Electrolyte outlet; 14. Gas storage and emission chamber; 15. Exhaust port; 16. Connector port. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0037] It should be noted that, unless otherwise defined, the directions such as up, down, left, and right mentioned in this document refer to the embodiments of this application. Figure 1The directions indicated are up, down, left, and right. If the specific posture changes, the directional indication will also change accordingly. The terms "first," "second," "third," "fourth," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Furthermore, in the various embodiments of this disclosure, the same or similar reference numerals denote the same or similar components.

[0038] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "connection" can refer to a fixed connection, a detachable connection, or an integral part, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] Furthermore, the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0040] Example 1

[0041] Please see Figures 1-4 As shown, this application provides a double-hollow-column high-curvature electrolytic cell, including double hollow columns and a connecting assembly 10 for connecting the double hollow columns. Its core structure includes an anode reaction chamber 1, a cathode reaction chamber 2, a proton exchange membrane 3, the connecting assembly 10, and a vacuum pump 11. The double hollow columns include a first hollow column 100 for forming the anode reaction chamber 1 and a second hollow column 200 for forming the cathode reaction chamber 2. The first hollow column 100 and the second hollow column 200 are respectively provided with... The system includes a first spiral electrolytic cell 51 and a second spiral electrolytic cell 52. The connecting assembly 10 includes a left connecting structure 10-1 connected to the first spiral electrolytic cell, a right connecting structure 10-2 connected to the second spiral electrolytic cell, and a proton exchange membrane 3 sandwiched between the left connecting structure 10-1 and the right connecting structure 10-2. This membrane separates the anode reaction chamber from the cathode reaction chamber while allowing selective proton permeation to achieve proton transfer in the electrochemical reaction, prevent the mixing of products at both electrodes, and ensure the directional conduction of the electrolysis reaction.

[0042] The high-curvature spiral electrolyzer of this application embodiment creates a turbulent effect (Dean vortex) when the electrolyte flows, which accelerates the separation of bubbles from the catalyst surface and greatly improves the mass transfer efficiency compared with the traditional static system. At the same time, it increases the electrochemical reaction rate, breaks through the limitations of the traditional planar electrode structure, and solves the difficult problem of low mass transfer efficiency caused by the accumulation of bubbles in the existing traditional structure.

[0043] It should be noted that in this embodiment, the "high curvature" of the double hollow column high curvature electrolytic cell refers to the radius of curvature R of the spiral electrolytic cell. C ≤5mm and Dean eddy current intensity κ>0.1 μm -1 curvature value ≥200m -1 The diameter is significantly higher than that of traditional planar or low-curvature electrolytic cells, not exceeding 50m. -1 The curvature value enables efficient bubble removal.

[0044] Example 2

[0045] Based on Embodiment 1, as a preferred implementation method, such as Figures 1-4 As shown, the anode reaction chamber 1 and the cathode reaction chamber 2 are symmetrically arranged about the proton exchange membrane 3, and are rigidly fixed and sealed by the connecting component 10. The internal structures of the anode reaction chamber 1 and the cathode reaction chamber 2 are completely identical. They are arranged from the outside to the inside as follows: an insulating shell 4, a sealing gasket 9, a high-curvature spiral electrolytic cell (first spiral electrolytic cell 51 / second spiral electrolytic cell 52), a carbon fiber cloth 6, a microporous breathable membrane 7, and a perforated insulating core 8. The perforated insulating core 8 encloses the hollow area of ​​the first hollow column 100. This hollow area is the reaction gas storage and emission chamber 14, and the exhaust port 15 at the top of it is connected to the vacuum pump 11. The top of the high-curvature spiral electrolytic cell is provided with a connector port 16 for connecting an external DC power supply.

[0046] Specifically, the first spiral electrolytic cell 51 and the second spiral electrolytic cell 52 are made of conductive carbon material, balancing conductivity and structural strength. They are integrally spiral hollow structures, with spiral grooves formed on their inner sides and the outer sides of the carbon fiber cloth 6. These spiral grooves serve as electrolyte channels. The core function of the spiral skeleton formed by the first spiral electrolytic cell 51 and the second spiral electrolytic cell 52 includes:

[0047] Conductive function: After connecting an external power source through the connector port 16 at the top, the current is uniformly transmitted to the catalyst coating on the surface of the carbon fiber cloth 6, providing electrons for the electrochemical reaction; Flow channel optimization: The spiral electrolyte flow channel allows the electrolyte to flow in from the electrolyte inlet 12. Due to the change in the curvature of the flow channel, a difference in "slow flow velocity on the inside and fast flow velocity on the outside" is generated, forming a turbulent effect (Dean vortex). This vortex can quickly wash away the bubbles on the catalyst surface, accelerate the separation of bubbles from the catalyst, and significantly improve the mass transfer efficiency of the gas-liquid-solid three-phase interface; Further, the radius of curvature R of the first spiral electrolytic cell 51 and the second spiral electrolytic cell 52 c

[0048] Preferably, the bubble size is no larger than 10 mm to ensure Dean flow intensity and achieve efficient bubble separation; combined with Figure 7As shown, side A represents the inner side of the spiral groove, and side B represents the outer side of the spiral groove. When the fluid flows along the spiral groove structure, the strong centrifugal force (F∝1 / R) throws the fluid towards side B, forming a high-pressure accumulation. This drives the secondary flow to impact the wall of side B, while side A becomes a low-pressure reflux zone. The two work together to form a vortex, achieving high-shear stripping of bubbles on the electrode surface. At the same time, the low-speed flow on side A prolongs the contact time between bubbles and the film surface, simultaneously optimizing the reaction and separation efficiency within a single flow channel. This completely overcomes the "fast inside, slow outside" flow field limitation of traditional large-curvature spiral tubes. Cost reduction: The materials of the first spiral electrolytic cell 51 and the second spiral electrolytic cell 52 in this embodiment are preferably conductive carbon materials, which have a lower cost than traditional solid titanium plates and a larger specific surface area, significantly improving the catalyst loading and utilization rate. Furthermore, the carbon fiber cloth 6 is a catalyst support woven from polyacrylonitrile-based carbon fibers, with a fiber filament spacing of 30-50 μm. The side of the cloth in contact with the electrolyte is coated with a platinum-rhodium composite catalyst coating with a thickness of 5-10 μm. The catalyst is fixed by the porous structure of the three-dimensional weaving of the carbon fiber cloth, forming a continuous electrocatalytic reaction interface. At the same time, the high specific surface area spiral electrolyzer structure increases the contact area between the catalyst coating and the electrolyte by 8-10 times compared with the planar electrode, greatly improving the electrochemical reaction rate.

[0049] Furthermore, the microporous breathable membrane 7 is made of polyvinylidene fluoride (PVDF) with a pore size of 0.1-0.5μm, sandwiched between the carbon fiber cloth 6 and the perforated insulating inner core 8; its function is to achieve "gas-liquid separation"—allowing the gas (such as H2, O2) generated by the electrochemical reaction to enter the reaction gas storage and emission chamber 14 through the pores, while preventing the electrolyte from penetrating into the inner core area, thus avoiding the mixing of electrolyte and gas and affecting the purity of the product.

[0050] Furthermore, the pores on the perforated insulating core 8 cooperate with the microporous breathable membrane 7, allowing the gas generated by the electrocatalytic reaction to pass through the microporous breathable membrane and then enter the reaction gas storage and discharge chamber 14 through the pores, and then be promptly removed by the external vacuum pump 11, so as to avoid the gas from accumulating in the electrolyte to form bubbles and hinder mass transfer.

[0051] The perforated insulating core 8 is preferably made of ceramic material. Its perforated design achieves air permeability while maintaining the structural rigidity of the core. It can cooperate with the structural skeleton formed by the high curvature spiral groove on the outside to clamp and fix the carbon fiber cloth, microporous breathable membrane and other components, and maintain the overall structural stability of the high curvature electrolytic cell.

[0052] In a preferred embodiment, the outer wall of the perforated insulating core 8 is uniformly distributed with spherical blunt-tipped protrusions. The top diameter of the protrusions is preferably 15 μm, and the protrusion length is no more than 80% of the thickness of the carbon fiber cloth, for example, preferably 70% of the thickness of the carbon fiber cloth. The protrusions are close to the inner side of the microporous breathable membrane 7 and extend into the fiber gaps of the carbon fiber cloth 6. Because the top diameter of the protrusions is smaller than the gap between the single filaments of the fibers, an interference fit is formed between the carbon fiber cloth and the microporous breathable membrane. The fibers undergo plastic deformation around the protrusions and fill the gaps, completely blocking the electrolyte leakage path. At the same time, the protrusions can limit the displacement of the carbon fiber cloth and the microporous breathable membrane, avoiding component displacement caused by electrolyte flow. Furthermore, the protrusions do not penetrate the microporous breathable membrane 7, ensuring that gas can normally pass through the membrane pores into the reaction gas storage and emission chamber 14 without hindering gas diffusion.

[0053] Example 3

[0054] Based on Embodiment 1 and Embodiment 2, as a preferred implementation method, such as Figures 4-6 As shown, the left connecting structure 10-1 and the right connecting structure 10-2 are mutually mirror-shaped arc plate structures, whose curvature matches the curvature of the spiral electrolytic cell. They are preferably made of 304 stainless steel. A hollow arc-shaped space 10-3 is opened between the layers. The height of the hollow arc-shaped space 10-3 is exactly the same as the height of a single spiral segment of the spiral electrolytic cell. During assembly, the spiral segment of the spiral electrolytic cell is embedded in the hollow arc-shaped space to achieve a tight fit between the two, preventing radial displacement of the spiral electrolytic cell due to vibration or thermal expansion, and improving the overall structural stability.

[0055] The fixed connection between the left connecting structure and the right connecting structure can preferably be achieved through a mortise and tenon joint; depending on the actual situation, it can also be preferably designed as a spring hinge closed connection, which uses the spring force to form continuous mechanical pressure to achieve a rigid connection between the left connecting structure 10-1 and the right connecting structure 10-2, which has the advantage of easy disassembly and facilitates the replacement and maintenance of the proton exchange membrane.

[0056] Example 4

[0057] Based on Embodiment 1, as a preferred implementation method, such as Figure 1As shown, the reaction gas storage and discharge chamber 14, enclosed by a perforated insulating inner core 8, has an exhaust port 15 at its top connected to a vacuum pump 11 via a polytetrafluoroethylene tube. During operation, the vacuum pump creates a slight negative pressure within the storage and discharge chamber, allowing the gas generated by the electrochemical reaction to quickly pass through the microporous permeable membrane 7 into the chamber and exit through the exhaust port. The slight negative pressure accelerates gas diffusion, preventing gas molecules from agglomerating on the membrane surface to form large bubbles, further reducing mass transfer resistance and bubble accumulation. Simultaneously, the reduction in bubbles lowers the local resistance of the electrode area, significantly reducing overpotential and ohmic loss, which is beneficial for improving the mass transfer efficiency and reaction rate of the spiral high-curvature electrolyzer.

[0058] In summary, this invention addresses the technical problems of low mass transfer efficiency and insufficient stability in traditional electrolyzers by optimizing the double hollow column structure, connection method, spiral groove flow channel design, and gas collection combined with a vacuum pump. It can be widely used in fields such as hydrogen energy production and wastewater treatment, and has significant industrial application value.

[0059] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the foregoing application concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions claimed in this application.

Claims

1. A double-hollow-column high-curvature electrolytic cell, characterized in that, include: The double hollow column includes a first hollow column for forming an anode reaction chamber and a second hollow column for forming a cathode reaction chamber. A first spiral electrolytic cell and a second spiral electrolytic cell are respectively disposed on the column walls of the first and second hollow columns. The first and second spiral electrolytic cells meet high curvature design requirements, with a curvature radius R. C ≤5mm, curvature value ≥200m -1 This causes turbulence when the electrolyte flows; The connecting assembly includes a left connecting structure connected to the first spiral electrolyzer, a right connecting structure connected to the second spiral electrolyzer, and a proton exchange membrane sandwiched between the left connecting structure and the right connecting structure. Both the left and right connecting structures have interlayered hollowed-out arc-shaped spaces, the height of which is consistent with the height of a single spiral of the first and second spiral electrolyzers, respectively, ensuring a tight fit between the first and second spiral electrolyzers and the hollowed-out arc-shaped spaces.

2. The double hollow column high curvature electrolytic cell according to claim 1, characterized in that, The anode reaction chamber comprises, from the outside to the inside, an insulating shell, a sealing gasket, a first spiral electrolytic cell, carbon fiber cloth, a microporous breathable membrane, and a perforated insulating core, wherein the perforated insulating core encloses the hollow region of the first hollow column. The installation structure of the cathode reaction chamber is the same as that of the anode reaction chamber.

3. The double hollow column high curvature electrolytic cell according to claim 2, characterized in that, The hollow area is a reaction gas storage and emission chamber, and the exhaust port of the reaction gas storage and emission chamber is connected to a vacuum pump.

4. The double hollow column high curvature electrolytic cell according to claim 1, characterized in that, Both the first spiral electrolytic cell and the second spiral electrolytic cell are equipped with connector ports for connecting to an external power source.

5. The double hollow column high curvature electrolytic cell according to claim 1, characterized in that, The left connecting structure and the right connecting structure are mirror images of each other; The left connecting structure and the right connecting structure are fixedly connected by a mortise and tenon joint.

6. The double hollow column high curvature electrolytic cell according to claim 2, characterized in that, The inner side of the first spiral electrolytic cell and the outer side of the carbon fiber cloth form a spiral groove, which is an electrolyte flow channel; The insulating shell has an electrolyte inlet at the upper end and an electrolyte outlet at the lower end. The electrolyte enters the spiral groove through the electrolyte inlet and is discharged through the electrolyte outlet.

7. The double hollow column high curvature electrolytic cell according to claim 2, characterized in that, The side of the carbon fiber cloth that is in contact with the electrolyte is coated with a catalyst coating, and the catalyst coating, together with the electrolyte and the first spiral electrolytic cell, constitutes an electrocatalytic reaction interface.

8. The double hollow column high curvature electrolytic cell according to claim 1, characterized in that, The first and second spiral electrolytic cells are made of conductive carbon material.

9. The double hollow column high curvature electrolytic cell according to claim 2, characterized in that, The outer wall of the perforated insulating inner core is provided with protrusions, which are in close contact with the inner side of the microporous breathable membrane. The top diameter of the protrusion is smaller than the gap between the single filaments of the carbon fiber cloth, the protrusion length of the protrusion is ≤ 80% of the thickness of the carbon fiber cloth, and the top is a spherical blunt head. The protrusions extend into the carbon fiber cloth but do not penetrate the microporous breathable membrane, thus achieving an interference fit between the carbon fiber cloth and the microporous breathable membrane.

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