A bipolar plate for a proton exchange membrane fuel cell and a proton exchange membrane fuel cell

Abstract

The application relates to the field of fuel cells, and particularly discloses a bipolar plate of a proton exchange membrane fuel cell and a proton exchange membrane fuel cell. The bipolar plate adopts a single-plate double-function design without changing electrochemical performance, an anode flow field is arranged on the front surface of the bipolar plate body, and a cathode flow field is arranged on the back surface of the bipolar plate body. The anode flow field is centrally supplied with gas and peripherally discharged with gas, and the cathode flow field is supplied with gas at four corners and discharged with gas at the centers of four edges. The anode flow field and the cathode flow field are both introduced into a human biology bionic structure, a 45-radian contraction type branch channel is set to copy a hierarchical conduction mode of a lung bronchus, the layout of the flow channel is iteratively optimized with the maximum mass transfer efficiency as the target, a topologically optimized hollow truss structure is arranged in a non-flow channel area, a 45-degree cross truss type hollow design is adopted in a low stress area with the target of "lightweight-strength synergy", local reinforcing ribs are reserved in a stress concentration area, the bipolar plate body is lightened, and the bending strength is improved.

Description

Technical Field

[0001] This invention relates to the field of fuel cells, and more specifically to a bipolar plate and a proton exchange membrane fuel cell. Background Technology

[0002] With the continuous growth of global energy demand and the increasing severity of environmental pollution, the development of sustainable clean energy has become a global research hotspot. Among numerous green energy technologies, hydrogen energy, as an ideal alternative energy source with high energy density and zero emissions, has attracted widespread attention.

[0003] As a core component of PEMFCs, bipolar plates play a crucial role in connecting battery cells in series, distributing reactant gases, and providing electronic connections. Their flow channel design directly affects gas distribution uniformity, water management efficiency, and battery power density. Existing flow field designs mainly include parallel flow fields, serpentine flow fields, radial flow fields, and biomimetic flow fields, but they have several shortcomings: parallel and serpentine flow fields suffer from uneven gas distribution, severe water accumulation, and excessive pressure drops, leading to low battery power density and poor stability; parallel flow fields have insufficient convective mass transfer capability at high current densities; serpentine flow fields have excessive pressure drops and significant parasitic power losses; traditional radial flow fields use symmetrical inlet designs, making it easy for gas supply channels to interfere with each other during stacking, which is difficult to meet the stacking requirements of high-power systems; while biomimetic flow fields can improve mass transfer, they often focus on single structural optimization without considering stacking feasibility. Furthermore, existing flow field designs do not incorporate systematic topology optimization, relying solely on empirical parameter adjustments, which cannot achieve multi-objective optimization of flow channel layout, structural strength, and processing technology, easily leading to low mass transfer efficiency or insufficient structural strength. Summary of the Invention

[0004] To address the aforementioned problems, this invention discloses a bipolar plate and a proton exchange membrane fuel cell. The device is based on the human lung bronchus as a biomimetic prototype, replicating its hierarchical conduction structure of "main trunk - secondary branch - terminal branch" and applying it to the branch region of the flow channel. Through multi-level branching, uniform gas diffusion and low-resistance conduction are achieved, allowing oxygen to enter from the main flow region and gradually diffuse to the entire reaction region through the secondary and terminal branches, thereby improving the uniformity of mass transfer.

[0005] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0006] A bipolar plate for a proton exchange membrane fuel cell includes a bipolar plate body, wherein an anode flow field is provided on the front side and a cathode flow field is provided on the back side of the bipolar plate body, and both the anode flow field and the cathode flow field are provided with biomimetic channels based on the hierarchical conduction structure of the bronchi in the human lungs.

[0007] The biomimetic channel includes a main flow region and tributary regions: the main flow region has a star-shaped structure, specifically including side flow channels for connecting the flow field center with the midpoints of each edge of the bipolar plate body and corner flow channels for connecting the flow field center with each corner of the bipolar plate body; the tributary region consists of multiple parallel arc-shaped flow channels, with adjacent side flow channels and corner flow channels connected by multiple parallel arc-shaped flow channels.

[0008] An anode inlet is provided at the center of the anode surface of the bipolar plate body, and multiple anode outlets are provided at each edge of the anode surface of the bipolar plate body.

[0009] A cathode air inlet is provided at all corners of the cathode surface of the bipolar plate body, and a cathode air outlet is provided at the midpoint of all edges of the cathode surface of the bipolar plate body.

[0010] Preferably, a collection area is provided at the edge of both the anode flow field and the cathode flow field, and the collection area is connected to all side flow channels and part of the arc flow channel.

[0011] Preferably, the two ends of the arc-shaped flow channel form a 45-degree angle with the side flow channel and the corner flow channel.

[0012] Preferably, the end of the arc-shaped flow channel is arranged perpendicular to the converging area.

[0013] Preferably, the cross-sectional area of ​​the flow channels in the tributary region is arranged in a gradient decreasing pattern along the gas flow direction.

[0014] Preferably, the bipolar plate body between the anode flow field and the cathode flow field is provided with a hollow truss structure.

[0015] Preferably, the hollow truss structure includes a central column, and connecting rods are provided between the upper and lower ends of the central column and the corner points of the bipolar plate body, wherein the upper connecting rod and the lower connecting rod form a horizontal V-shape.

[0016] Preferably, the volume of the hollowed-out area of ​​the hollowed-out truss structure accounts for 30%-40% of the volume of the non-flow channel area of ​​the bipolar plate.

[0017] The present invention also discloses a proton exchange membrane fuel cell, including a membrane electrode, wherein a bipolar plate as described above is respectively disposed at the upper and lower ends of the membrane electrode.

[0018] Preferably, two adjacent bipolar plates are interlocked, and threaded holes are provided at the corners of the bipolar plates. All bipolar plates are connected as a whole by screws passing through the threaded holes.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. This invention adopts an asymmetric inlet design for anode and cathode gas, which ensures that the anode and cathode gas channels do not interfere with each other. Combined with the threaded holes at the corners, it achieves precise positioning and effectively solves the technical problems existing in the traditional radial flow field stacking process. The hollow truss structure formed by topology optimization significantly reduces the weight of the bipolar plates while significantly enhancing their bending strength. It can adapt to the long-term stable operation requirements of high-power proton exchange membrane fuel cell systems and achieves a triple improvement in stacking feasibility, structural strength and lightweighting.

[0021] 2. This invention designs a biomimetic flow channel that replicates the mass transfer characteristics of the lung bronchi. Combined with a topology-optimized flow channel layout and the auxiliary heat dissipation effect of the hollow structure, the electrochemical performance is significantly improved compared to traditional parallel flow fields, serpentine flow fields, and single biomimetic or topology-optimized structures. Simultaneously, mass transfer capacity, water management capacity, and heat dissipation capacity are synergistically enhanced.

[0022] 3. The biomimetic hierarchical bifurcation structure and topology-optimized cross-sectional area distribution of the tributary region of this invention can reduce the oxygen uniformity index and reduce the amount of liquid water accumulation, effectively avoiding flooding problems; the gap channels formed by the hollow truss can improve the heat dissipation efficiency of the bipolar plate, and significantly improve the mass transfer stability compared with the existing technology, showing better performance compared with serpentine flow field and parallel flow field.

[0023] 4. The topology-optimized flow channel layout and hollow structure can accurately match the gas flow pattern. The pressure drop of the flow field using this scheme is lower than that of the serpentine flow field, and the average static pressure is significantly reduced compared to the serpentine flow field, thereby reducing parasitic power loss. After topology optimization, the flow field and hollow structure can be adapted to conventional etching processes, and the manufacturing cost is significantly reduced compared to the three-dimensional mesh flow field. At the same time, it avoids the problem of increased processing difficulty caused by excessive complexity of biomimetic structures, and takes into account both process feasibility and economy, achieving a double reduction in energy consumption and process cost. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the anode side structure of the proton exchange membrane fuel cell of the present invention;

[0026] Figure 2 for Figure 1 Enlarged diagram of part A in the middle;

[0027] Figure 3This is a schematic diagram of the cathode side structure of the proton exchange membrane fuel cell of the present invention;

[0028] Figure 4 for Figure 3 Enlarged diagram of section B;

[0029] Figure 5 This is a schematic diagram of the cathode air intake structure;

[0030] Figure 6 This is a schematic diagram of the orthographic projection of the anode side of the proton exchange membrane fuel cell of the present invention;

[0031] Figure 7 This is a schematic diagram of the orthographic projection of the cathode side of the proton exchange membrane fuel cell of the present invention;

[0032] Figure 8 This is a diagram of the gas flow direction in the cathode flow field;

[0033] Figure 9 This is a diagram showing the gas flow direction in the anode flow field;

[0034] Figure 10 This is a schematic diagram of the hollow truss structure and membrane electrode distribution of the proton exchange membrane fuel cell of the present invention;

[0035] Figure 11 This is a top view of the hollow truss structure of the proton exchange membrane fuel cell of the present invention;

[0036] Figure 12 This is a schematic diagram of the proton exchange membrane fuel cell stack structure of the present invention;

[0037] Reference numerals: 100, bipolar plate body; 200, membrane electrode; 11, anode side groove; 111, anode rib; 112, anode air inlet; 1121, anode air inlet; 1122, anode air outlet; 12, cathode side groove; 121, cathode rib; 122, cathode air inlet; 123, cathode air outlet; 124, cathode main flow area; 125, cathode tributary area; 1251, cathode biomimetic branch channel; 126, cathode converging area; 127, cathode flow field; 14, anode flow field; 15, threaded hole; 17, cathode air inlet; 150, screw; 130, hollow truss structure; 1301, central column; 1302, connecting rod. Detailed Implementation

[0038] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0039] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0040] Example 1

[0041] like Figures 1 to 7 As shown, this invention discloses a bipolar plate for a proton exchange membrane fuel cell. This embodiment uses a quadrilateral bipolar plate as an example, but other shapes can be designed and manufactured according to actual needs. The bipolar plate adopts a "single-plate dual-function" composite structure. An anode flow field 14 is provided on the front side of the bipolar plate body 100, and a cathode flow field 127 is provided on the back side of the bipolar plate body 100. Both the anode flow field 14 and the cathode flow field 127 include groove structures for constructing gas flow channels and rib structures for separating adjacent flow channels. The collection of groove structures forms a biomimetic channel based on the hierarchical conduction structure of the human lung bronchi.

[0042] The anode flow field formed by the anode-side groove 11 and the cathode flow field formed by the cathode-side groove 12 both comprise three parts: a main flow region, a tributary region, and a confluence region. Each region has multiple flow channels. The flow channel located in the main flow region is called the main flow channel, and the flow channel located in the tributary region is called the auxiliary flow channel. This multi-stage flow channel is formed by multiple sets of ribs spaced apart. The anode side has an anode rib 111, and the cathode side has a cathode rib 121. The ribs have a 45-degree arc structure protruding towards the center of the flow field. All the ribs in the same flow field are divided into eight groups by the main flow region composed of cross-shaped channels. Multiple ribs in the same tributary region are arranged parallel to each other. Combined with the hierarchical and bifurcation design of the tributary region, this avoids the gas flow path becoming monotonous, effectively improves the gas distribution state, and suppresses the generation of uneven gas distribution and edge effects.

[0043] The main flow region is distributed in a cross-shaped structure in the flow field, specifically covering the side flow channels connected to each edge line of the bipolar plate body 100 and the corner flow channels connected to each corner point of the bipolar plate body 100; the auxiliary flow channels are located between the adjacent side flow channels and corner flow channels in the cross-shaped structure, and adopt a multi-channel parallel design and a perpendicular arrangement to the edge line of the bipolar plate.

[0044] The following is a detailed explanation using the cathode flow field as an example:

[0045] The cross-shaped cathode-side main flow channel forms the cathode main flow region 124. The cathode-side auxiliary flow channel is a 45-degree cathode bionic branch channel 1251 that replicates the structure of the human lung bronchus, forming a composite flow field pattern of "cross-shaped main flow channel + bionic auxiliary flow channel", which further optimizes the uniformity of gas distribution throughout the entire region, especially improving the stability of gas supply in the edge region.

[0046] The ribs on both sides of the main channel leading to the midpoint of the flow field edge are discontinuous. The positions of the rib breakpoints are adjusted through topology optimization to reduce dead zones where liquid water can stagnate. The main channel width is set to 2mm, while the auxiliary channel (i.e., the cathode biomimetic branch channel 1251) is designed with a gradient decreasing width: 1.2mm at the inlet and 0.6mm at the outlet. The cathode rib 121 is 0.5mm wide, with a contraction rate controlled at 0.5. These parameter settings, combined with the discontinuous rib structure and biomimetic channel morphology, effectively reduce liquid water accumulation, improve drainage capacity, and prevent flooding. The rib breakpoint positions are adjusted through topology optimization. Simultaneously, drawing inspiration from the gradient change characteristics of bronchial cross-sectional areas, a contracting flow channel (the inlet cross-sectional area is twice that of the outlet) is designed to accelerate gas flow while avoiding pressure loss due to excessively high local velocities, thus meeting the gas supply requirements of PEMFCs.

[0047] A vertical cathode air inlet 122 is provided at each of the four corners on the cathode side of the bipolar plate body 100, for a total of 4; a cathode air inlet channel 17 is provided at the bottom of the cathode air inlet 122 to connect the cathode air inlet 122 and the cathode corner flow channel; a cathode air outlet 123 is provided at the center of the horizontal direction on the four sides of the bipolar plate body 100, near the cathode end, that is, at the cathode side edge line of the bipolar plate body, for a total of 4 cathode air outlets 123 on the four edge lines.

[0048] A cathode collecting region 126 is provided at the cathode side edge of the bipolar plate body, and the flow channel width of the cathode collecting region 126 is also 2mm. The end of the cathode rib 121 is arranged perpendicular to the cathode collecting region 126.

[0049] like Figure 8 As shown, the cathode gas (oxygen) flows through the cathode inlet 122 through the cathode side of each bipolar plate body 100, enters the cathode main flow region 124 through the cathode inlet channel 17, and after initial distribution through the star-shaped main flow channel, flows into the cathode biomimetic branch channel 1251 to achieve uniform diffusion; after participating in the electrochemical reaction, the remaining gas flows through the cathode collection region 126, exits the cathode flow field through the cathode outlet 123, and is finally discharged from the battery through the cathode side outlet channel.

[0050] The distribution of the main flow channel and auxiliary flow channel on the anode side is the same as that on the cathode side, and will not be repeated here. The difference lies in the positions of the inlet and outlet, as detailed below:

[0051] A hollow cylinder is provided at the center of the anode side of the bipolar plate body 100. The center of the hollow cylinder is set as the anode air inlet 1121. The bottom side wall of the hollow cylinder is provided with an anode air inlet channel 112 connecting the anode air inlet 1121 and the anode main flow area. Anode air outlets 1122 are evenly distributed on the four sides of the bipolar plate body 100 near the anode end, that is, at the anode side edge of the bipolar plate body. Nine outlets are provided on each side, and a total of 36 outlets 1122 are provided on the four sides.

[0052] like Figure 9 As shown, the anode gas (hydrogen) flows through the anode inlet 1121 across the anode side of each bipolar plate body 100, enters the anode flow field 14 through the anode inlet channel 112, and diffuses radially and uniformly in all directions under the guidance of the star-shaped main flow channel and surrounding auxiliary flow channels. The remaining reaction gas flows out of the anode flow field through 36 anode outlets 1122 evenly distributed around the perimeter, and is then discharged from the battery through the anode side outlet channel. In addition, the anode inlet channel 112 has a partially hollowed-out interior for the anode side gas channel boss, forming a reinforced structure. This reduces the weight of the boss without affecting gas flow, while ensuring the load-bearing stability during stack assembly.

[0053] This invention employs a multi-inlet radial flow field structure, with one central inlet at the anode and four edge inlets at the cathode. This structure, in conjunction with a star-shaped flow channel, a biomimetic auxiliary flow channel, and a topology-optimized perforated structure, significantly improves the uniformity of gas distribution in the edge region, effectively solving the problem of uneven gas distribution at the edges commonly found in traditional radial flow fields. Testing shows that the oxygen uniformity index is significantly lower than in traditional flow fields, and the gas distribution consistency is significantly optimized. Simultaneously, the flow path, designed with topology optimization, offers the advantages of a short, bend-free path. Combined with the gradient cross-sectional area flow channel morphology and the guiding function of the perforated structure, the average static pressure of the bipolar plates is significantly reduced compared to serpentine flow fields, greatly reducing gas flow pressure loss and battery parasitic energy loss, thereby improving the energy efficiency and high performance of the fuel cell stack.

[0054] Example 2

[0055] The bipolar plate body 100 is a three-dimensional structure. In this embodiment, the bipolar plate body 100 located between the anode flow field 14 and the cathode flow field 127 is provided with the following... Figure 10 and Figure 11The hollow truss structure 130 shown is a central column 1301. Four connecting rods 1302 radiate from the upper and lower ends of the central column 1301. The other end of each connecting rod 1302 extends obliquely towards the midpoint of the bipolar plate body 100 in the vertical direction and connects to one of the four corner points of the bipolar plate body 100 in the circumferential direction. Thus, the upper and lower connecting rods form a transverse V-shaped structure with an opening facing the central column 1301. The volume of the hollow area of ​​this hollow truss structure accounts for 30%-40% of the volume of the non-flow channel area of ​​the bipolar plate. The layout of the hollow truss structure 130 and all ribs in the flow field are determined through synchronous topology optimization iteration. Through coupled mechanics-thermal-mass transfer multiphysics analysis, a balance between mass transfer efficiency and structural strength is achieved. The hollow truss structure 130 reduces the overall weight of the bipolar plate and improves its bending strength.

[0056] The hollow truss structure 130 is distributed in the non-channel area of ​​the bipolar plate. The low-stress area adopts the hollow truss, while the stress concentration area (edge ​​of the positioning hole, root of the boss) retains high-density material to form local reinforcing ribs. This reduces the weight of the bipolar plate compared to a solid structure, while improving its bending strength, achieving a synergistic optimization of "lightweight and high strength". The hollow area can also assist in heat dissipation of the channel, reducing the operating temperature of the bipolar plate. At the same time, the gap channels formed by the hollow truss area can accelerate the heat dissipation of the bipolar plate, controlling the operating temperature fluctuation of the cathode channel area within 8°C, and avoiding material performance degradation caused by high temperature.

[0057] Example 3

[0058] like Figure 10 and Figure 12 As shown, in this embodiment, multiple bipolar plate bodies 100 are stacked together, and membrane electrodes 200 are arranged between adjacent bipolar plate bodies 100 to form a proton exchange membrane fuel cell.

[0059] A further improvement of this invention is that four threaded holes 15 for stacking are provided at the four corners of the bipolar plate body 100 outside the flow field. After the bipolar plate body 100 and the membrane electrode 200 are stacked into a battery, screws 150 are used to pass through all the threaded holes 15 to connect the battery into a whole. The threaded holes 15 achieve precise positioning, significantly improving the feasibility of stacking, solving the traditional radial flow field stacking problem, improving the assemblability of the bipolar plate, and adapting to high-power stacking requirements. The hollow truss structure 130 is designed in conjunction with the threaded holes 15, and a solid reinforcing structure is used around the threaded holes 15 to avoid local strength attenuation caused by the hollow structure.

[0060] In summary, this invention, based on a multi-inlet structure, integrates human biomimetic design, topology optimization technology, and a hollow truss integrated structure to construct a bipolar plate that combines composite flow channel morphology, precise parameter matching, lightweight and high-strength characteristics, and convenient assembly advantages. The core of this bipolar plate possesses advantages such as uniform distribution of reactant gases, low pressure loss, strong drainage capacity, high heat dissipation efficiency, resistance to flooding, and convenient assembly, demonstrating significant practical application value and promising prospects in the field of proton exchange membrane fuel cells.

[0061] The terms "upper," "lower," "outer side," "inner side," "radial," and "circumferential" used in this specification, claims, and foregoing drawings, if applicable, are only used to define relative positional relationships, specifically referring to the end face, flow channel region, perforated truss distribution area, and assembly orientation of the bipolar plate body 100, and do not require absolute definition. It should be understood that such directional terms can be interchanged in reasonable scenarios; for example, "upper side" can correspond to the anode end face, and "lower side" can correspond to the cathode end face, thereby allowing embodiments of the present invention to be implemented in orders other than those illustrated and described herein. Furthermore, the terms "comprising," "possessing," and their various variations are intended to cover a non-exclusive scope. For example, a bipolar plate integrating human biomimetic structures, topology-optimized layouts, and perforated trusses is not limited to the rib structures, flow channel morphologies, and perforated unit sizes explicitly listed in the specification, but may also encompass derivative size specifications adapted to different power requirements, auxiliary sealing components, and perforated morphology variations based on multi-physics coupling optimization.

[0062] The detailed description of the disclosed embodiments above is sufficient to enable those skilled in the art to implement or apply the present invention. Those skilled in the art can make various modifications to these embodiments, all of which are obvious, such as adjusting the porosity of the hollowed-out truss, optimizing the constraints of topology iteration, and adapting the hollowed-out parameters to different material systems. The general principles defined herein can be applied to other implementation scenarios without departing from the spirit and scope of the present invention. For example, the biomimetic design concept of the human lung bronchus, topology optimization methods, and hollowed-out lightweight technology can be extended to bipolar plates of proton exchange membrane fuel cells of different specifications, or adapted to other types of fuel cells by adjusting the flow channel and hollowed-out synergistic parameters. Therefore, the present invention should not be limited to the embodiments shown herein, but should cover the broadest scope consistent with the principles and innovative features disclosed herein. Its core innovations include key technological breakthroughs such as the synergistic construction of multiple air inlets and biomimetic-topology-optimized-hollowed-out structures, the coordinated achievement of lightweight and high strength, and the simultaneous optimization of easy-to-assemble structures and electrochemical performance.

[0063] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bipolar plate for a proton exchange membrane fuel cell, comprising a bipolar plate body (100), characterized in that, The bipolar plate body (100) has an anode flow field (14) on the front and a cathode flow field (127) on the back. Both the anode flow field (14) and the cathode flow field (127) are provided with biomimetic channels based on the hierarchical conduction structure of the human lung bronchus. The biomimetic channel includes a main flow region and tributary regions. The main flow region has a star-shaped structure, specifically including side flow channels for connecting the flow field center with the midpoints of each edge of the bipolar plate body and corner flow channels for connecting the flow field center with each corner of the bipolar plate body. The tributary region consists of multiple parallel arc-shaped flow channels, and adjacent side flow channels and corner flow channels are connected by multiple parallel arc-shaped flow channels. An anode inlet (1121) is provided at the center of the anode surface of the bipolar plate body (100), and multiple anode outlets (1122) are provided at each edge of the anode surface of the bipolar plate body (100). A cathode air inlet (122) is provided at all corners of the cathode surface of the bipolar plate body (100), and a cathode air outlet (123) is provided at the midpoint of all edges of the cathode surface of the bipolar plate body (100). The bipolar plate body (100) between the anode flow field (14) and the cathode flow field (127) is provided with a hollow truss structure (130). The hollow truss structure (130) includes a central column (1301), and connecting rods (1302) are provided between the upper and lower ends of the central column and the corner points of the bipolar plate body (100). The upper connecting rod and the lower connecting rod form a horizontal V-shape. The volume of the hollowed-out area of ​​the hollowed-out truss structure accounts for 30%-40% of the volume of the non-flow channel area of ​​the bipolar plate.

2. The bipolar plate of a proton exchange membrane fuel cell according to claim 1, characterized in that, A collection area is provided at the edge of the anode flow field (14) and the edge of the cathode flow field (127), and the collection area is connected to all side flow channels and some arc flow channels.

3. The bipolar plate of a proton exchange membrane fuel cell according to claim 2, characterized in that, The two ends of the arc-shaped flow channel form a 45-degree angle with the side flow channel and the corner flow channel.

4. The bipolar plate of a proton exchange membrane fuel cell according to claim 2, characterized in that, The ends of the arc-shaped flow channel are arranged perpendicularly to the collection area.

5. The bipolar plate of a proton exchange membrane fuel cell according to claim 1, characterized in that, The cross-sectional area of ​​the flow channels in the tributary region is arranged in a gradient decreasing pattern along the gas flow direction.

6. A proton exchange membrane fuel cell, comprising a membrane electrode assembly (200), characterized in that, The membrane electrode (200) is provided with a bipolar plate as described in any one of claims 1 to 5 at its upper and lower ends respectively.

7. A proton exchange membrane fuel cell according to claim 6, characterized in that, Two adjacent bipolar plates are connected by interlocking. Threaded holes (15) are provided at the corners of the bipolar plates. All bipolar plates are connected as a whole by screws (150) that pass through the threaded holes (15).

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