Bipolar plate for electrode support and gas-liquid flow distribution structure in electrolytic bath

Abstract

The bipolar plate comprises a circular substrate and an annular frame on the periphery, the thickness of the circular substrate is smaller than that of the annular frame, the circular substrate is arranged in the middle of the annular frame in the thickness direction, and straight L-shaped conductive ribs and arc L-shaped conductive ribs are arranged on the surface of the circular substrate; the straight L-shaped conductive ribs are arranged along the flowing direction of the electrolyte, and V-shaped diversion structures are arranged at the bottoms of the straight L-shaped conductive ribs; the arc L-shaped conductive rib is arranged between the V-shaped diversion structure and the bottom edge of the circular substrate; and the arc L-shaped conductive rib corresponding to the V-shaped diversion structure is provided with a diversion port. According to the invention, the flow distribution of the electrolyte on the bipolar plate can be optimized, the lateral flow of the electrolyte on the bipolar plate and the mass transfer rate of the electrolyte are promoted, the flow uniformity of the electrolyte and the hydrogen production efficiency are improved, and meanwhile, the effects of reducing the temperature of the diaphragm, preventing the diaphragm from being damaged and reducing the energy loss of the electrolytic cell are achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of electrolytic hydrogen production, and in particular to a bipolar plate for supporting electrodes inside an electrolytic cell and a gas-liquid distribution structure. BACKGROUND

[0002] As the most industrialized process in the field of hydrogen production by water electrolysis, alkaline water electrolysis technology has fully met the application conditions for large-scale hydrogen production, with decades of industrial operation experience and a mature and reliable production system.

[0003] As a key technology for clean energy transformation, the core challenge of alkaline water electrolysis for hydrogen production is how to balance efficiency improvement and cost optimization. The bipolar plate of an industrial-grade alkaline water electrolysis system is generally circular or square, and the circular bipolar plate is prone to uneven distribution of electrolyte. As one of the key factors for reducing energy consumption, the flow channel design on the circular bipolar plate cannot be ignored.

[0004] There are three methods for the existing bipolar plate and electrode support structure, the first method is to process a papillary structure on the bipolar plate, the upper part of the papillary structure is extruded together with the electrode during assembly, relying on contact conduction, and the lower part of the papillary structure is used for electrolyte and gas flow.

[0005] The second method is to set a corrugated elastic buffer net between the bipolar plate and the electrode, the buffer net relies on contact conduction, and the gap between the buffer nets serves as a flow channel for electrolyte and gas.

[0006] The third method is to uniformly arrange conductive ribs between the bipolar plate and the electrode, the lower part of the conductive rib is welded to the bipolar plate, and the upper part of the conductive rib is welded to the electrode, which can effectively reduce the contact resistance.

[0007] The first and second methods described above rely on contact conduction, and depend on the processing accuracy and assembly accuracy. In actual use, it is impossible to ensure that all electrode surfaces are in good contact with the papillary structure or the buffer net. Inconsistent contact will lead to uneven distribution of current, thereby increasing the energy consumption of the electrolytic cell. Moreover, the elastic buffer net has problems such as uneven pressure distribution, poor dynamic condition adaptation, flow channel blockage, short elastic service life, high maintenance cost, etc.

[0008] In the third method, the arrangement of the conductive ribs does not take into account the problem of uneven distribution of electrolyte in the electrolysis chamber, which leads to local temperature rise in the electrolysis chamber, gas accumulation, and performance degradation of the electrolytic cell. SUMMARY

[0009] The technical problem solved by the present application is to provide a bipolar plate for electrode support and gas-liquid flow distribution structure inside an electrolytic cell, which can optimize the flow distribution of electrolyte on the bipolar plate, promote the lateral flow of electrolyte on the bipolar plate and the mass transfer rate of electrolyte, improve the uniformity of electrolyte flow and hydrogen output efficiency, and achieve the effects of reducing the temperature of the diaphragm, preventing damage to the diaphragm, and reducing the energy loss of the electrolytic cell.

[0010] To solve the above technical problems, the present application provides a bipolar plate for electrode support and gas-liquid flow distribution structure inside an electrolytic cell, comprising a circular base plate and an annular frame on the outer periphery, the circular base plate has a thickness smaller than the thickness of the annular frame and is arranged in the middle of the thickness direction of the annular frame, and the surface of the circular base plate is provided with straight L-shaped conductive ribs and circular arc L-shaped conductive ribs.

[0011] The straight L-shaped conductive ribs are arranged along the flow direction of the electrolyte, and the bottom of the straight L-shaped conductive ribs is provided with a V-shaped flow guide structure.

[0012] The circular arc L-shaped conductive ribs are arranged between the V-shaped flow guide structure and the bottom edge of the circular base plate.

[0013] The V-shaped flow guide structure is provided with a flow guide opening on the corresponding circular arc L-shaped conductive rib.

[0014] The flow guide opening is used for primary flow distribution of the electrolyte, and the V-shaped flow guide structure is used for secondary flow distribution of the electrolyte after primary flow distribution.

[0015] Further, the bottom of the straight L-shaped conductive ribs and the circular arc L-shaped conductive ribs is provided with a bending contact unit, the bending contact unit is connected to the surface of the circular base plate by welding, the bottom edge of the straight L-shaped conductive rib is arranged in close contact with the surface of the circular base plate, and the flow guide opening is arranged between adjacent two bending contact units.

[0016] Further, the surface of the straight L-shaped conductive rib is provided with a through hole, the diameter of the through hole is 2-4mm, the spacing between adjacent two through holes is 5-10mm, and the through hole is used to connect the spaces on both sides of the straight L-shaped conductive rib.

[0017] Further, the material of the straight L-shaped conductive rib and the circular arc L-shaped conductive rib is stainless steel 316L or nickel, and the thickness is 1-2mm.

[0018] Further, the spacing between adjacent side edges between adjacent two flow guide openings is 70%-85% of the spacing between the vertices of the corresponding two V-shaped flow guide structures.

[0019] Further, the shortest distance gap between the top of the straight L-shaped conductive rib and the inner wall of the annular frame is 1-2 mm, the shortest distance gap between the vertex of the V-shaped flow guide structure and the inner wall of the annular frame is 10-15 mm, the side length of the V-shaped flow guide structure is 25-35 mm, and the spacing between adjacent two straight L-shaped conductive ribs is 40-100 mm.

[0020] Further, the diameter of the circular arc of the circular arc L-shaped conductive rib is 8-12 mm smaller than the diameter of the circular substrate.

[0021] Further, the annular frame is provided with an electrolyte inlet, and the electrolyte inlet is arranged towards the surface of the circular arc L-shaped conductive rib between adjacent two flow guide ports, and the distance between the electrolyte inlet and the surface of the corresponding circular arc L-shaped conductive rib is 3-4 mm.

[0022] Further, the height of the flow guide port is 3-4 mm.

[0023] Further, the bipolar plate is prepared by the following steps:

[0024] A bottom plate of the circular substrate and the annular frame is integrally formed;

[0025] The number and size of the straight L-shaped conductive rib are planned according to the diameter of the circular substrate, the spacing between the straight L-shaped conductive ribs, and the spacing between the end of the straight L-shaped conductive rib and the adjacent annular frame.

[0026] The size of the circular arc L-shaped conductive rib and the number of flow guide ports are determined according to the number of straight L-shaped conductive ribs.

[0027] The straight L-shaped conductive rib and the circular arc L-shaped conductive rib are prepared; first, a planar development structure is cut by laser, and then the shape of the straight L-shaped conductive rib and the circular arc L-shaped conductive rib is bent out.

[0028] The straight L-shaped conductive rib and the circular arc L-shaped conductive rib are arranged on the surface of the circular substrate and welded and fixed to complete the preparation.

[0029] The beneficial effects of the present application are:

[0030] The present application provides an electrolytic cell internal electrode support and gas-liquid distribution structure, which can form a partitioned flow channel structure on the bipolar plate, the circular arc L-shaped conductive rib is a first partition for one-time electrolyte distribution, and the V-shaped flow guide structure of the straight L-shaped conductive rib is a second partition for two-time electrolyte distribution, which can effectively enhance the uniformity of electrolyte flow, realize good electrolyte distribution uniformity and mass transfer performance, and improve the lateral flow and flow rate of electrolyte.

[0031] The electrolyte flow rate and uniformity can effectively remove the electrolysis generated gas, reduce the accumulation of gas in the electrolysis chamber, improve the current density and temperature distribution, avoid local high temperature causing the damage of the diaphragm, and at the same time, improve the electrolysis reaction rate and reduce the energy consumption of the electrolysis cell. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a schematic diagram of the overall structure of the present application;

[0033] Figure 2 is a schematic diagram of the straight L-shaped conductive rib structure of the present application;

[0034] Figure 3 is a schematic diagram of the arc L-shaped conductive rib structure of the present application;

[0035] Figure 4 is a schematic diagram of the structure of the present application for the cooperation of the straight L-shaped conductive rib and the arc L-shaped conductive rib for flow distribution;

[0036] Figure 5 is a hydrogen volume fraction distribution diagram in the cathode of the electrolysis cell of the support structure of the present application;

[0037] Figure 6 is a hydrogen volume fraction distribution diagram in the cathode of the electrolysis cell of the conventional support structure. DETAILED DESCRIPTION

[0038] The present application will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present application and implement it, but the embodiments are not limiting to the present application.

[0039] Referring to Figures 1 to 4 the embodiment of the bipolar plate for the electrode support and gas-liquid distribution structure inside the electrolysis cell of the present application, as shown, includes a circular base plate 1 and an annular frame on the outer periphery, the circular base plate has a thickness smaller than the thickness of the annular frame and is arranged in the middle of the thickness direction of the annular frame, thereby forming an effective concave structure to accommodate the support structure and the electrolyte, the support structure is a straight L-shaped conductive rib 2 and an arc L-shaped conductive rib 3 arranged on the surface of the circular base plate; the materials of the straight L-shaped conductive rib and the arc L-shaped conductive rib are stainless steel 316L or nickel, and the thickness is 1-2 mm, which meets the need for electrical conductivity.

[0040] The straight L-shaped conductive rib is arranged along the flow direction of the electrolyte, and the bottom of the straight L-shaped conductive rib is provided with a V-shaped flow guide structure 8; the arc L-shaped conductive rib is arranged between the V-shaped flow guide structure and the bottom edge of the circular base plate; the V-shaped flow guide structure is provided with a flow guide opening 13 on the corresponding arc L-shaped conductive rib;

[0041] The flow guide port is used to divert the electrolyte flowing in from the electrolyte inlet 4 at the bottom of the annular frame. The V-shaped flow guide structure further diverts the electrolyte after the first diversion. An electrolyte / gas outlet 5 is provided at the top of the annular frame to discharge the gas after electrolysis, which generally contains some electrolyte.

[0042] In practical use, the aforementioned support structure is used to support the electrode connection. The electrolyte flows in from the electrolyte inlet and impacts the surface of the L-shaped conductive ribs. That is, the electrolyte inlet faces the surface of the L-shaped conductive ribs between two adjacent guide ports. The electrolyte cannot flow directly inward, but flows to both sides along the arc surface of the L-shaped conductive ribs, that is, along the outer arc surface. During the flow, due to the design of the guide ports, the electrolyte will flow upward from the guide ports. Multiple guide ports can form a distribution effect on the electrolyte, that is, a first diversion. After the electrolyte is unobstructed, it continues to flow upward. The straight L-shaped conductive ribs are arranged along the direction of electrolyte flow. Therefore, the flow resistance of the straight L-shaped conductive rib body to the electrolyte is greatly reduced, and the flow resistance of the gas generated by electrolysis is also greatly reduced.

[0043] A V-shaped flow guiding structure is set at the bottom of the straight L-shaped conductive ribs. This structure can divert the electrolyte flowing out of the flow guide. That is, when the electrolyte flows, it will flow towards the apex of the V-shaped flow guiding structure. After contacting the V-shaped flow guiding structure, the electrolyte continues to flow along the two inclined surfaces of the V-shaped flow guiding structure, forming a secondary flow diversion effect. This ensures that the electrolyte distribution flow rate among multiple straight L-shaped conductive ribs is uniform and the flow dynamics are relatively stable.

[0044] The combination of the arc-shaped L-shaped conductive ribs and the straight L-shaped conductive ribs forms a zoned flow channel structure. The arc-shaped L-shaped conductive ribs form the first zone, which performs a first electrolyte diversion, while the V-shaped flow guiding structure of the straight L-shaped conductive ribs forms the second zone, which performs a second electrolyte diversion.

[0045] Through holes 10 are provided on the surface of the above-mentioned straight L-shaped conductive ribs. The diameter of the through holes is 2-4 mm, the spacing between two adjacent through holes is 5-10 mm, and they are evenly distributed. The through holes are used to connect the spaces on both sides of the straight L-shaped conductive ribs, effectively enhance the lateral flow of electrolyte, and help to disperse the bubbles generated by electrolysis.

[0046] The aforementioned straight L-shaped conductive ribs and arc-shaped L-shaped conductive ribs are fixed to the circular substrate by welding. To facilitate fabrication and ensure structural stability during use, bent contact units are provided at the bottom of both the straight L-shaped and arc-shaped conductive ribs. Specifically, straight L-shaped contact units 6 are provided on the straight L-shaped conductive ribs. These straight L-shaped contact units are rectangular, with consistent dimensions and spacing, measuring 15-25mm in length and 10-20mm in width. The contact units are arranged at 60-80mm intervals and are welded to the circular substrate. Arc-shaped L-shaped contact units 11 are provided on the arc-shaped conductive ribs, with adjacent arc-shaped contact units... With inconsistent dimensions and spacing, the arc-shaped L-shaped contact unit is positioned between the V-shaped flow guiding structure of two straight L-shaped conductive ribs. The arc-shaped L-shaped conductive rib body size corresponding to the arc-shaped contact unit needs to cover 70%-85% of the distance between the two V-shaped flow guiding structures. When the electrolyte impacts the surface of the arc-shaped L-shaped conductive rib from the electrolyte inlet at the bottom of the annular frame, a higher coverage ratio (e.g., 85%) reduces the possibility of the electrolyte directly penetrating the gap, forcing the electrolyte to flow preferentially to both sides along the arc surface, achieving primary flow diversion. A 15%-30% gap is retained to allow a small amount of electrolyte to pass through, preventing excessive flow resistance. The arc-shaped L-shaped contact unit is connected to the surface of the circular substrate by welding. The bottom edge 9 of the straight L-shaped conductive rib is tightly attached to the surface of the circular substrate to enhance the bending strength of the straight L-shaped conductive rib.

[0047] The straight L-shaped top surface 7 of the straight L-shaped conductive rib and the arc L-shaped top surface 12 of the arc L-shaped conductive rib are both used to contact the electrode and form a supporting effect, and are fixed to the electrode by welding.

[0048] Based on the above structure, this application also specifies the structural dimensions, specifically: the shortest distance between the top of the straight L-shaped conductive rib and the inner wall of the annular frame is 1-2 mm. This 1-2 mm gap provides sufficient assembly tolerance, avoiding structural interference caused by thermal expansion or mechanical stress, while ensuring the stability of the electrode support and preventing the electrode from collapsing due to compression. The shortest distance between the apex of the V-shaped flow guide structure and the inner wall of the annular frame is 10-15 mm, the side length of the V-shaped flow guide structure is 25-35 mm, and the spacing between two adjacent straight L-shaped conductive ribs is 40-100 mm. The 10-15mm gap provides a buffer space for secondary electrolyte diversion. The apex of the V-shaped flow guide structure is far from the edge, allowing the electrolyte to diffuse fully before impacting the V-shaped structure, reducing flow kinetic energy loss. This helps to smoothly transition to secondary diversion, avoid eddies or turbulence, and improve mass transfer efficiency. The side length of the V-shaped flow guide structure is in the range of 25-35mm, ensuring that the V-shaped structure has sufficient surface area to guide the electrolyte diversion. The wide spacing range of 40-100mm allows for flexible adjustment according to the bipolar plate size. A smaller spacing (40mm) can increase the flow channel density, improve support uniformity and conductivity, while a larger spacing (100mm) reduces flow resistance and is suitable for large-size bipolar plates. The arc diameter of the L-shaped conductive rib is 8-12mm smaller than the diameter of the circular substrate. The distance between the electrolyte inlet and the surface of the corresponding L-shaped conductive rib is 3-4mm, creating edge flow channel space so that the electrolyte can be evenly distributed to the outer periphery of the bipolar plate. The height of the guide port is 3-4mm, which ensures the electrolyte flow rate and allows it to overflow from the guide port for distribution, thus enhancing the controllability of the flow distribution.

[0049] The vertex of the aforementioned V-shaped flow guiding structure is located in the middle of the flow guiding port, so as to evenly divide the electrolyte into secondary flows. Specifically, since the flow guiding port is set on the arc surface of the L-shaped conductive rib, and the electrolyte flow direction is upward, the middle part here can be understood as: the midpoint of the projection shape of the flow guiding port in the electrolyte flow direction is the base point, and the vertex of the V-shaped flow guiding structure is located on the extension line of the base point along the electrolyte flow direction.

[0050] This application also discloses a method for preparing a bipolar plate:

[0051] A base plate integrally formed from a circular substrate and an annular frame was prepared.

[0052] The number and size of the straight L-shaped conductive ribs are planned based on the diameter of the circular substrate, the spacing of the straight L-shaped conductive ribs, and the distance between the end of the straight L-shaped conductive ribs and the adjacent annular frame; the core is to cover the entire effective electrolysis area as much as possible.

[0053] The dimensions of the arc-shaped L-shaped conductive ribs and the number of flow guides are determined based on the number of straight L-shaped conductive ribs.

[0054] Prepare straight L-shaped conductive ribs and arc L-shaped conductive ribs; first, cut out the planar unfolded structure by laser cutting, and then bend out the shape of straight L-shaped conductive ribs and arc L-shaped conductive ribs by bending;

[0055] Straight L-shaped conductive ribs and arc-shaped L-shaped conductive ribs are arranged on the surface of a circular substrate and welded to fix them, thus completing the preparation.

[0056] Specifically, a CFD-based fluid simulation was performed on a bipolar plate with an effective electrolysis area and a diameter of 960 mm. The specific simulation settings are shown in Table 1. The support structure of the present invention was compared with the conventional support structure with straight L-shaped conductive ribs without V-shaped flow guiding structure.

[0057] Table 1 Fluid Simulation Settings

[0058] The specific simulation results are shown in Table 2:

[0059] Table 2 Fluid simulation results

[0060] The uniformity of electrolyte distribution on a certain plane is quantitatively evaluated by the average volume fraction of the electrolyte. The closer the mass-weighted uniformity is to 1, the more uniform the electrolyte distribution. In this embodiment, the uniformity of electrolyte distribution on 10 planes perpendicular to the bipolar plate plane from the bipolar plate electrolyte inlet to the bipolar plate electrolyte outlet is evaluated. These 10 planes are selected at equal intervals and numbered 1 to 10. Plane 1 is the plane closest to the electrolyte inlet and plane 10 is the plane closest to the electrolyte outlet. The 10 planes cover the entire bipolar plate area.

[0061] Simulation Result Analysis:

[0062] I. In the simulation results of the support structure of the present invention, the average volume fraction of electrolyte on all 10 planes is relatively large. The average volume fraction of electrolyte on all planes is 6.7% higher than that of conventional support structures. Moreover, the average volume fraction of electrolyte on planes 1 to 4 is very close to 1, indicating that the electrolyte distribution above the bipolar plate electrolyte inlet is relatively uniform due to the partitioned flow channel structure.

[0063] Second, the average volume fraction of electrolyte in planes 9-10 of the present invention is much greater than that in the simulation results of conventional support structures, indicating that the hydrogen content accumulated below the electrolyte outlet of the bipolar plate is less, which can alleviate the phenomenon of excessively high temperature below the electrolyte outlet of the bipolar plate.

[0064] three, Figure 5 This is the volume fraction distribution of hydrogen in the cathode of the electrolytic cell in the support structure of the present invention. Figure 6The volume fraction distribution of hydrogen in the cathode of an electrolytic cell with a conventional support structure indicates that, apart from a large accumulation of hydrogen at the outlet, there is no significant accumulation of hydrogen in other parts of the support structure of the present invention. This demonstrates that the electrode support and gas-liquid distribution structure inside the electrolytic cell provided by the present invention can enhance the discharge of gases generated during electrolysis.

[0065] In summary, this invention provides an internal electrode support and gas-liquid distribution structure for an electrolyzer that effectively enhances the uniformity of electrolyte flow and the discharge of electrolysis-generated gases, while reducing gas accumulation within the electrolysis chamber. Specifically, it optimizes the electrolyte flow distribution on the bipolar plates, promotes lateral electrolyte flow and mass transfer rate on the bipolar plates, thereby improving electrolyte flow uniformity and hydrogen extraction efficiency. Simultaneously, it reduces diaphragm temperature, prevents diaphragm damage, and minimizes energy loss in the electrolyzer.

[0066] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A bipolar plate for electrolyzer internal electrode support and gas-liquid distribution structure, characterized in that, The circular substrate is arranged in the middle of the annular frame in the thickness direction, and the surface of the circular substrate is provided with straight L-shaped conductive ribs and circular arc L-shaped conductive ribs. The straight L-shaped conductive ribs are arranged along the electrolyte flow direction, and the bottom of the straight L-shaped conductive ribs is provided with a V-shaped flow guide structure. The circular arc L-shaped conductive ribs are arranged between the V-shaped flow guide structure and the bottom edge of the circular substrate. The V-shaped flow guide structure is provided with a flow guide opening corresponding to the circular arc L-shaped conductive rib. The flow guide opening is used for primary flow distribution of the electrolyte, and the V-shaped flow guide structure is used for secondary flow distribution of the electrolyte after primary flow distribution.

2. The bipolar plate for the electrolyzer internal electrode support and gas-liquid distribution structure according to claim 1, characterized in that, The bottom of the straight L-shaped conductive rib and the circular arc L-shaped conductive rib is provided with a bending contact unit, the bending contact unit is connected with the surface of the circular substrate by welding, the bottom edge of the straight L-shaped conductive rib is arranged close to the surface of the circular substrate, and the flow guide opening is arranged between the two adjacent bending contact units.

3. The bipolar plate for the electrolyzer internal electrode support and gas-liquid distribution structure of claim 1, wherein, The surface of the straight L-shaped conductive rib is provided with a through hole, the diameter of the through hole is 2-4mm, the spacing between the two adjacent through holes is 5-10mm, and the through hole is used for connecting the spaces on both sides of the straight L-shaped conductive rib.

4. The bipolar plate for the electrolyzer internal electrode support and gas-liquid distribution structure of claim 1, wherein, The material of the straight L-shaped conductive rib and the circular arc L-shaped conductive rib is stainless steel 316L or nickel, and the thickness is 1-2mm.

5. The bipolar plate for the electrolyzer internal electrode support and gas-liquid distribution structure according to claim 1, characterized in that, The spacing between the adjacent sides between the two adjacent flow guide openings is 70%-85% of the spacing between the two V-shaped flow guide structure vertices.

6. The bipolar plate for electrolyzer internal electrode support and gas-liquid distribution structure of claim 1, wherein, The shortest distance gap between the top of the straight L-shaped conductive rib and the inner wall of the annular frame is 1-2mm, the shortest distance gap between the vertex of the V-shaped flow guide structure and the inner wall of the annular frame is 10-15mm, the side length of the V-shaped flow guide structure is 25-35mm, and the spacing between the two adjacent straight L-shaped conductive ribs is 40-100mm.

7. The bipolar plate for electrolyzer internal electrode support and gas-liquid distribution structure of claim 1, wherein, The diameter of the circular arc of the circular arc L-shaped conductive rib is 8-12mm smaller than the diameter of the circular substrate.

8. The bipolar plate for electrolyzer internal electrode support and gas-liquid distribution structure of claim 1, wherein, The lower part of the annular frame is provided with an electrolyte inlet, the electrolyte inlet is arranged towards the surface of the circular arc L-shaped conductive rib between the two adjacent flow guide openings, and the distance between the electrolyte inlet and the surface of the corresponding circular arc L-shaped conductive rib is 3-4mm.

9. The bipolar plate for the electrolyzer internal electrode support and gas-liquid distribution structure according to claim 8, characterized in that, The height of the flow guide opening is 3-4mm.

10. The bipolar plate for the electrolyzer internal electrode support and gas-liquid distribution structure of claim 1, wherein, The bipolar plate is prepared by the following steps: Preparation of a bottom plate integrated with a circular substrate and an annular frame; Planning the number and size of the straight L-shaped conductive ribs according to the diameter of the circular substrate, the spacing between the straight L-shaped conductive ribs and the spacing between the end of the straight L-shaped conductive rib and the adjacent annular frame; Determining the size of the circular arc L-shaped conductive rib and the number of flow guide openings according to the number of straight L-shaped conductive ribs; Preparation of straight L-shaped conductive ribs and circular arc L-shaped conductive ribs; First, the planar development structure is cut out by laser cutting, and then the shape of the straight L-shaped conductive rib and the circular arc L-shaped conductive rib is folded by bending; The straight L-shaped conductive rib and the circular arc L-shaped conductive rib are arranged on the surface of the circular substrate and welded and fixed to complete the preparation.

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