Self-drainage fuel cell bipolar plate, drainage method and fuel cell

Abstract

The invention relates to a self-drainage fuel cell bipolar plate, a drainage method and a fuel cell. The self-drainage fuel cell bipolar plate comprises a bipolar plate main body, wherein a runner structure is arranged on the surface of the bipolar plate main body; the cilia structure is distributed on the surface of the runner structure; the gas inlet and the gas outlet are formed in the two ends of the flow channel structure respectively so as to allow reaction gas to enter and generate water after reaction to be discharged; a solid-liquid film is formed between the water drops and the top end of the cilium structure, and water generated after gas reaction is discharged on the solid-liquid film along the flow channel structure in a sliding mode. According to the self-drainage fuel cell bipolar plate, efficient drainage is achieved by arranging the runner structure and the cilia structure, the cilia structure imitates cilia on the leg surface of a water strider and is in a filament shape, water drops can only make contact with the top ends of the cilia to form a solid-liquid film, the solid-liquid film is discharged in a sliding mode along the runner, and the water drops are effectively prevented from being detained in a flow field.

Description

Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a self-draining fuel cell bipolar plate, a drainage method and a fuel cell. Background Art

[0002] With the development of technologies in the fields of energy and environmental protection, proton exchange membrane fuel cell technology has emerged. This is an efficient green power generation device that can directly convert the chemical energy in fuel and oxidant into electrical energy. Its biggest feature is that the power generation process is pollution-free, the products are only electrical energy, thermal energy and water, and the power generation efficiency is high; proton exchange membrane fuel cells not only have high power density and can start quickly at room temperature, but also have high flexibility, so they have broad application prospects in electric vehicles, home power stations, space stations and other fields.

[0003] In the related technology, the structural design of the proton exchange membrane fuel cell mainly includes bipolar plates, gas diffusion layers, catalyst layers and proton exchange membranes. Among them, the bipolar plate, also known as the flow field plate, is one of the important components of the fuel cell. Its main functions include uniform distribution of the reaction gas, timely discharge of the water generated by the reaction, heat conduction and electron transfer. In order to achieve these functions, the flow field is cleverly processed on the bipolar plate, and its structural design is designed to ensure that the reaction gas can evenly participate in the reaction everywhere on the plate, and at the same time, the water generated by the reaction can be discharged in time.

[0004] Among them, the parallel flow field is a common drainage flow field design. The number of parallel flow field channels is large and short. Such a design makes the flow resistance small, which is conducive to the smooth flow of gas. However, in practical applications, when the battery continues to work, due to the relatively slow gas flow rate, the water generated by the reaction tends to gather at the edge of the flow channel, forming the so-called "flooding phenomenon". This phenomenon not only leads to poor drainage inside the battery, but may also cause local swelling of the membrane electrode, which has a serious impact on the stability, durability and efficiency of the battery.

[0005] Therefore, although the above-mentioned parallel flow field design method improves the gas flow efficiency to a certain extent, it fails to effectively solve the drainage problem of the water generated by the reaction, which is an important problem that needs to be solved urgently in the current development of proton exchange membrane fuel cell technology. Summary of the invention

[0006] Based on this, it is necessary to provide a self-draining fuel cell bipolar plate, drainage method and fuel cell to address the above problems, so that through the synergistic effect of the flow channel structure and the ciliary structure, the formation of a solid-liquid film between the water droplets and the top of the ciliary structure can be achieved, and the water produced after the reaction is discharged in a sliding manner along the flow channel structure, effectively solving the water management problem inside the fuel cell and improving the operating efficiency and stability of the fuel cell.

[0007] A self-draining fuel cell bipolar plate, comprising:

[0008] A bipolar plate body, on the surface of which a flow channel structure is arranged;

[0009] Cilia structures, distributed on the inner surface of the flow channel structure;

[0010] The gas inlet and the gas outlet are respectively arranged at the two ends of the flow channel structure to allow the reaction gas to enter and the water generated after the reaction to be discharged;

[0011] A solid-liquid film is formed between the water droplet and the top of the ciliary structure, and the water generated after the gas reaction is discharged along the flow channel structure in a sliding manner on the solid-liquid film.

[0012] In one of the embodiments, the cilia structure imitates the cilia on the surface of the legs of a water strider, each cilia structure is a filamentous structure, and the size of the cilia structure and the spacing between them are smaller than the diameter of a water droplet, so that the water droplet forms a solid-liquid film on the inner surface of the flow channel structure, and the water generated after the gas reaction slides and discharges along the flow channel structure; the cilia structure imitates the cilia on the surface of the legs of a water strider, which can effectively prevent the water droplets from wetting the inner surface of the flow channel and forming a solid-liquid film, so that the water droplets can be discharged along the flow channel in a sliding manner, thereby greatly improving the drainage efficiency, reducing the occurrence of flooding, and improving the stability and durability of the fuel cell.

[0013] In one of the embodiments, the flow channel structure includes a plurality of flow channels arranged in parallel, ridges between the flow channels, and upper and lower flow channels; the flow channel structure on the bipolar plate body can ensure the uniform distribution of the reaction gas and improve the performance of the fuel cell; at the same time, the plurality of flow channels arranged in parallel not only enhance the overall structural strength of the parallel flow field, but also ensure the uniform distribution of gas and the smooth discharge of water by cooperating with the upper and lower flow channels, thereby further optimizing the working performance of the fuel cell.

[0014] In one embodiment, the upper flow channel and the lower flow channel are used to connect the flow channels in the flow channel structure, and the flow channels, ridges, and the upper flow channel and the lower flow channel cooperate as a whole to form a parallel flow field.

[0015] In one of the embodiments, the flow channel has an inclination angle from top to bottom. The inclined flow channel utilizes gravity to allow the generated water to flow downward along the flow channel more naturally, thereby reducing water retention in the flow channel and improving drainage efficiency.

[0016] In one of the embodiments, the upper flow channel corresponds to the air inlet, and the lower flow channel corresponds to the air outlet; the air inlet and the air outlet can ensure the smooth entry of the reaction gas, uniform distribution and reaction, and finally timely discharge, thereby maintaining the gas balance inside the fuel cell and helping to improve the working efficiency of the fuel cell.

[0017] A drainage method for a self-draining fuel cell bipolar plate, using the self-draining fuel cell bipolar plate, through the synergistic effect of a flow channel structure and a ciliary structure, promotes the formation of a solid-liquid film between water generated by the reaction gas and the ciliary structure, and slides and discharges along the flow channel structure;

[0018] The drainage process is as follows:

[0019] Step 1: The fuel cell is working, and the reaction gas enters the flow channel structure including the ciliary structure;

[0020] Step 2: The reaction gas undergoes an electrochemical reaction on the membrane electrode surface to generate water;

[0021] Step three, when the water generated by the electrochemical reaction gathers in the flow channel structure, the water droplets form a solid-liquid film with the top of the ciliary structure and are discharged along the flow channel structure by sliding.

[0022] The drainage method of the self-draining fuel cell bipolar plate realizes the formation of a solid-liquid film between the water droplets and the top of the ciliary structure through the synergistic effect of the flow channel structure and the ciliary structure, and slides out along the flow channel structure, effectively solving the water management problem inside the fuel cell and improving the operating efficiency and stability of the fuel cell.

[0023] In one embodiment, the ciliary structure is in the form of filaments and is evenly distributed on the side walls of each flow channel and ridge in the flow channel structure, and each flow channel has an inclination angle from top to bottom.

[0024] A fuel cell, the fuel cell structure includes a self-draining fuel cell bipolar plate, through the synergistic effect between the flow channel structure and the ciliary structure on the fuel cell bipolar plate, the gas entering from the air inlet is promoted to react to generate water, a solid-liquid film is formed between the water droplets and the ciliary structure, and the reaction generated water slides along the flow channel structure and is discharged; the fuel cell using the self-draining fuel cell bipolar plate can significantly improve the internal water management condition, reduce the risk of flooding, improve the gas utilization rate and electrochemical reaction efficiency, thereby improving the overall performance and reliability of the fuel cell.

[0025] The above-mentioned self-draining fuel cell bipolar plate achieves efficient drainage by setting up a flow channel structure and a cilia structure. The design of the cilia structure allows water droplets to only contact the top of the cilia to form a solid-liquid film, and be discharged by sliding along the direction of the flow channel, thereby effectively preventing water droplets from being retained in the flow field; the cilia structure imitates the cilia on the surface of the legs of water striders. This bionic design is simple and easy to make in practical applications, and can effectively solve the drainage problem inside the fuel cell; at the same time, the effective drainage mechanism allows the reaction gas to pass through the flow field more smoothly, thereby improving the gas flow efficiency, which helps to improve the overall efficiency and performance of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] In addition, the drawings are not drawn to a 1:1 scale, and the relative sizes of various elements are drawn in the drawings only as examples and not necessarily according to the true scale.

[0029] FIG. 1 is a schematic diagram of the structure of a bipolar plate for a fuel cell in one embodiment.

[0030] FIG. 2 is a schematic diagram of the flow channel structure of a bipolar plate of a fuel cell in one embodiment.

[0031] Figure 3 Schematic diagram of the ciliary structure on the bipolar plate of a fuel cell in one embodiment.

[0032] Description of reference numerals:

[0033] 1. Bipolar plate body; 2. Ridge; 3. Flow channel; 4. Cilia structure; 5. Upflow channel; 6. Downflow channel; 7. Air inlet; 8. Air outlet. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0035] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0036] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0037] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0038] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0039] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0040] Referring to Fig. 1, Fig. 1 shows a schematic diagram of the structure of a self-draining fuel cell bipolar plate in an embodiment of the present application. The self-draining fuel cell bipolar plate provided in an embodiment of the present application includes a bipolar plate body 1, a ridge 2, a flow channel 3, a ciliary structure 4, an upper flow channel 5, a lower flow channel 6, an air inlet 7, and an air outlet 8.

[0041] In some embodiments, the bipolar plate body 1 serves as the supporting structure of the entire bipolar plate, adopts a flat plate design, and has good strength and stability; the bipolar plate body 1 is used to support and connect the various components of the fuel cell to ensure the normal operation of the fuel cell; the material selection of the bipolar plate body 1 needs to have good electrical conductivity, thermal conductivity and corrosion resistance to cope with the complex working environment inside the fuel cell.

[0042] In some embodiments, a plurality of flow channels 3 periodically arranged in parallel along the vertical direction are engraved on the surface of the bipolar plate body 1; a ridge 2 is formed between each two adjacent flow channels 3, and the design of the ridge 2 not only enhances the structural strength of the bipolar plate body 1, but also provides necessary support for the flow channel 3; at the same time, the presence of the ridge 2 also helps to guide the liquid water to be discharged along the inclined direction of the flow channel 3.

[0043] Combined with Figure 2, Figure 2 shows a schematic diagram of the flow channel structure of the fuel cell bipolar plate in an embodiment of the present application. In some embodiments, the flow channel 3 is on the bipolar plate body 1 and is used as the main channel for transmitting the reaction gas and discharging the generated water; in the present application, the shape of the flow channel 3 is designed to be rectangular to ensure the smooth flow of gas and water;

[0044] In some embodiments, the flow channel 3 has a certain inclination angle α from top to bottom, so that liquid water can be more easily discharged along the inclination direction of the flow channel under the action of gravity; in actual operation, the size and distribution density of the flow channel 3 need to be optimized according to the working requirements of the fuel cell to ensure the best effect of gas mass transfer efficiency and drainage efficiency.

[0045] Combination Figure 3 As shown, Figure 3A schematic diagram of a ciliary structure 4 on a fuel cell bipolar plate in an embodiment of the present application is shown. In some embodiments, the ciliary structure 4 is evenly arranged on the sidewalls of each flow channel 3 and ridge 2 to form a layer of tiny filamentous structure; the size of the ciliary structure 4 and the spacing between each other are much smaller than the diameter of the water droplet, so that the water droplet cannot infiltrate the surface of the flow channel 3 and the ridge 2 inside the flow field, but forms a solid-liquid film with the top of the ciliary through the extremely thin air layer between the cilia. The existence of this solid-liquid film enables water to be discharged from the flow channel by sliding along the inclined direction of the flow channel 3, thereby greatly improving the drainage efficiency.

[0046] In some embodiments, an upper channel 5 and a lower channel 6 connecting each flow channel 3 are respectively engraved at the upper inlet and the lower outlet of the flow channel 3; the upper channel 5 and the lower channel 6 together with each flow channel 3 constitute a parallel flow field, providing necessary channels for the uniform distribution of the reaction gas and the smooth discharge of the water generated after the reaction; a number of ciliary structures 4 are also evenly distributed on the surface of the upper channel 5 and the lower channel 6 at equal intervals, ensuring that the drainage effect in the entire flow field is consistent and the inside of the flow field will not be wetted by water.

[0047] In some embodiments, an air inlet 7 is provided at a vertex position of the upper flow channel 5 for introducing reaction gas, and an air outlet 8 is provided at a vertex position of the lower flow channel 6 opposite thereto for discharging reacted gas and water.

[0048] In some embodiments, the drainage method of the fuel cell bipolar plate of the present application is to allow the reaction gas to enter the parallel flow field from the air inlet 7, and the reaction gas undergoes an electrochemical reaction in the parallel flow field to generate water; the generated water flows evenly into each flow channel 3 from the upper flow channel 5. Since the size of the ciliary structure 4 set on the surface of the upper flow channel 5, the flow channel 3, the ridge 2 and the lower flow channel 6 and the distance between them are much smaller than the diameter of the water droplet, the water droplet cannot infiltrate the inside of the flow field, but forms a solid-liquid film with the top of the ciliary. This solid-liquid film enables the water droplet to slide out of the flow channel along the inclined direction of the flow channel 3.

[0049] The detailed steps of the drainage method of the fuel cell bipolar plate in this application are as follows:

[0050] Step 1, introduction of reaction gas: the reaction gas is introduced into the upper flow channel 5 through the gas inlet 7, and the upper flow channel 5 ensures the uniform distribution of the reaction gas, providing the necessary conditions for the subsequent electrochemical reaction;

[0051] Step 2: electrochemical reaction occurs: inside the flow channel 3, the reaction gas undergoes an electrochemical reaction, and water is generated during the electrochemical reaction. The generated water then flows into the flow channel 3 through the upper flow channel 5;

[0052] Step 3, forming a solid-liquid film: When the generated water flows into the flow channel 3, due to the existence of the ciliary structure 4, the water droplets cannot infiltrate the parallel flow field; on the contrary, since the ciliary structure 4 is a filamentous structure and the size and spacing between them are much smaller than the diameter of the water droplets, the water droplets form a solid-liquid film with the top of the cilia through the extremely thin air layer between the cilia. This solid-liquid film enables the water to be discharged from the flow channel by sliding along the inclined direction of the flow channel 3;

[0053] Step 4: discharge after reaction: the gas and water after reaction pass through the downflow channel 6 and are discharged from the gas outlet 8 .

[0054] In a specific embodiment, the structure of the self-draining fuel cell bipolar plate of the present application specifically includes:

[0055] A bipolar plate body 1, which is a flat plate; a plurality of flow channels 3 periodically arranged in parallel in the vertical direction are engraved on the front surface of the bipolar plate, a ridge 2 is formed between each adjacent flow channel 3, and the flow channel is rectangular; a ciliary structure 4 is provided on each flow channel and ridge, and the flow channel 3 has a certain inclination angle α from top to bottom; each ciliary structure 4 is filamentous; an upper flow channel 5 and a lower flow channel 6 connecting the flow channels 3 are engraved on the front surface of the bipolar plate body 1, and at the upper and lower ends of the ridge 2, respectively, and a plurality of ciliary structures 4 are evenly distributed on the upper and lower flow channel surfaces at equal intervals; an air inlet 7 is provided at a vertex of the upper flow channel 5, and an air outlet 8 is provided at a vertex of the lower flow channel 6 opposite thereto;

[0056] The ridge 2 is rectangular in shape and includes a primary ridge and a secondary ridge. The primary ridge and the secondary ridge are part of the flow channel structure and mainly play the role of supporting and separating the flow channel 3 to ensure that the reaction gas can be evenly distributed in the flow channel 3 and perform an effective electrochemical reaction.

[0057] Among them, the primary ridge is the main supporting structure in the bipolar plate flow channel structure, with high strength and rigidity;

[0058] The primary ridge extends along the length direction of the bipolar plate body 1, dividing the bipolar plate body 1 into multiple areas, and a flow channel 3 is formed in each area; the main function of the primary ridge is to provide separation between the flow channels 3 to prevent the gases in different flow channels 3 from mixing with each other, while ensuring that each flow channel 3 can obtain a uniform gas supply.

[0059] Among them, the secondary ridges are located between the primary ridges, and are used to further subdivide the flow channel 3; compared with the primary ridges, the size and height of the secondary ridges are smaller than the primary ridges, and the secondary ridges also play a role in ensuring uniform distribution of gas in the flow channel 3; the existence of the secondary ridges helps to increase the number of flow channels 3, thereby improving the reaction efficiency of the gas per unit area;

[0060] Specifically, the width of the primary ridge is 0.5 mm to 1 mm, and the height is 0.5 mm to 2 mm; the width of the secondary ridge is 0.05 mm to 0.1 mm, and the height is 0.2 mm to 0.5 mm;

[0061] Specifically, the width of the primary flow channel is 0.5 mm to 1 mm.

[0062] The diameter of the ciliary structure 4 is 10 μm to 20 μm, the height is 20 μm to 30 μm, and the spacing between adjacent ciliary structures 4 is 20 μm to 30 μm.

[0063] The inclination angle α of the flow channel 3 is 3° to 8°.

[0064] In actual operation of the present application, when the fuel cell is working, the reaction gas enters the parallel flow field from the air inlet 7, an electrochemical reaction occurs, and the water generated by the electrochemical reaction flows evenly into each flow channel 3 from the upper flow channel 5. Since the ciliary structure 4 is arranged on the surface of the flow channel 3 and the ridge 2, the ciliary structure 4 is filamentous, and the size of the ciliary structure 4 and the distance between each other are much smaller than the diameter of the water droplet, the water droplet can only slightly contact with the top of the ciliary cilia through the extremely thin air layer between the cilia, and cannot infiltrate the inside of the flow field, and the water droplet and the top of the ciliary cilia form a layer of solid-liquid film;

[0065] The water generated by the reaction is discharged from the flow channel 3 by sliding on the solid-liquid film along the inclined direction of the flow channel 3; the self-drainage mechanism of the fuel cell of the present application reduces the phenomenon of liquid water retention in the flow field, improves the drainage efficiency, thereby reducing the phenomenon of fuel cell flooding, and further improves the gas mass transfer efficiency, which is beneficial to improving the gas utilization rate and stability performance of the fuel cell.

[0066] Under the same working conditions, the fuel cell using the self-draining fuel cell bipolar plate in the present application has higher drainage efficiency and gas utilization rate than the traditional bipolar plate; at the same time, the stability performance of the fuel cell is also significantly improved. The self-draining fuel cell bipolar plate of the present application promotes the reaction of the gas entering from the air inlet 7 to generate water through the synergistic effect between the flow channel structure and the ciliary structure 4, and a solid-liquid film is formed between the water droplets and the ciliary structure 4. The water generated by the reaction slides and is discharged along the flow channel structure. The ciliary structure 4 imitates the biological structure in nature, which improves the drainage efficiency, thereby reducing the phenomenon of flooding in the fuel cell, and further improving the gas mass transfer efficiency, which is conducive to improving the gas utilization rate and stability performance of the fuel cell, and has significant technical advantages and application prospects.

[0067] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A self-draining fuel cell bipolar plate, characterized in that: include: A bipolar plate body, on the surface of which a flow channel structure is arranged; Cilia structures, distributed on the inner surface of the flow channel structure; and The gas inlet and the gas outlet are respectively arranged at the two ends of the flow channel structure to allow the reaction gas to enter and the water generated after the reaction to be discharged; A solid-liquid film is formed between the water droplet and the top of the ciliary structure, and the water generated after the gas reaction is discharged along the flow channel structure in a sliding manner on the solid-liquid film.

2. The self-draining fuel cell bipolar plate according to claim 1, characterized in that: The cilia structure imitates the cilia on the surface of the legs of a water strider. Each cilia structure is a filamentous structure. The size of the cilia structure and the distance between them are smaller than the diameter of the water droplets, so that the water droplets form a solid-liquid film on the inner surface of the flow channel structure, and the water generated after the gas reaction slides and is discharged along the flow channel structure.

3. The self-draining fuel cell bipolar plate according to claim 1 or 2, characterized in that: The flow channel structure includes a plurality of flow channels arranged in parallel, ridges between the flow channels, and upper flow channels and lower flow channels.

4. The self-draining fuel cell bipolar plate according to claim 3, characterized in that: The upper flow channel and the lower flow channel are used to connect the flow channels in the flow channel structure, and the flow channels, the ridges, and the upper flow channel and the lower flow channel cooperate as a whole to form a parallel flow field.

5. The self-draining fuel cell bipolar plate according to claim 3, characterized in that: The flow channel has an inclination angle from top to bottom.

6. The self-draining fuel cell bipolar plate according to claim 3, characterized in that: The upper flow channel is connected to the air inlet correspondingly, and the lower flow channel is connected to the air outlet correspondingly.

7. A method for draining water from a self-draining fuel cell bipolar plate, characterized in that: The self-draining fuel cell bipolar plate described in any one of claims 1 to 6 promotes the formation of a solid-liquid film between the water generated by the reaction gas and the ciliary structure through the synergistic effect of the flow channel structure and the ciliary structure, and slides and discharges along the flow channel structure.

8. The method for draining water from a self-draining fuel cell bipolar plate according to claim 7, characterized in that: The drainage method includes the following steps: Step 1: The fuel cell is working, and the reaction gas enters the flow channel structure including the ciliary structure; Step 2: The reaction gas undergoes an electrochemical reaction on the membrane electrode surface to generate water; Step three, when the water generated by the electrochemical reaction gathers in the flow channel structure, the water droplets form a solid-liquid film with the top of the ciliary structure and are discharged along the flow channel structure by sliding.

9. The method for draining water from a self-draining fuel cell bipolar plate according to claim 8, characterized in that: The ciliary structures are filamentous and evenly distributed on the side walls of each flow channel and ridge in the flow channel structure, and each flow channel has an inclination angle from top to bottom.

10. A fuel cell, characterized in that: The fuel cell structure includes a self-draining fuel cell bipolar plate as described in any one of claims 1 to 6, and the synergistic effect between the flow channel structure and the ciliary structure on the fuel cell bipolar plate promotes the reaction of gas entering from the air inlet to generate water, and a solid-liquid film is formed between the water droplets and the ciliary structure, and the water generated by the reaction slides along the flow channel structure and is discharged.

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