Fuel cell and bipolar plate thereof

Abstract

The utility model discloses a fuel cell and a bipolar plate thereof, the bipolar plate of the fuel cell comprises an anode single plate, a cathode single plate and a cooling layer, and the cooling layer is located between the anode single plate and the cathode single plate. The cooling layer comprises a liquid inlet distribution area, a liquid outlet distribution area and a cooling layer reaction area communicated with the liquid inlet distribution area and the liquid outlet distribution area; ridges, forming adjacent cooling liquid flow channels, of the liquid inlet distribution area are distributed in a radial mode in the cooling liquid flowing direction, and the groove width of the liquid outlet distribution area is gradually increased in the cooling liquid flowing direction. In the bipolar plate of the fuel cell provided by the invention, the ridges of the adjacent cooling liquid flow channels formed in the liquid inlet distribution region are radially distributed along the flowing direction of the cooling liquid, so that the cooling liquid in the cooling region is more uniformly distributed. The groove width of the liquid outlet distribution area is gradually increased along the flowing direction of the cooling liquid, so that the cooling liquid can be conveniently discharged after being collected, and therefore, the heat dissipation effect of the bipolar plate of the fuel cell is improved.

Description

Technical Field

[0001] This utility model relates to the field of fuel cell technology, and in particular to a bipolar plate for a fuel cell. This utility model also relates to a fuel cell including the aforementioned bipolar plate. Background Technology

[0002] A proton exchange membrane fuel cell (PEMFC) is a new type of power generation device that is highly efficient and environmentally friendly. A PEMFC converts chemical energy into electrical energy through a chemical reaction between hydrogen and oxygen within the fuel cell stack. It is primarily composed of two core components: bipolar plates and membrane electrode assemblies (MEAs), which are assembled in series. The bipolar plates play crucial roles in supporting and fixing the MEAs, separating fuel and oxidizing gases, collecting current, and conducting current. In a PEMFC stack, the cost of the bipolar plates accounts for approximately 20-40% of the stack's total cost.

[0003] In PEMFCs, bipolar plates account for the majority of the total stack mass, typically exceeding 80%, and their volume percentage is also over 70%. Reducing the weight of bipolar plates is crucial in lightweight design. One effective method to achieve this is usually reducing the thickness of the bipolar plates. However, as the bipolar plates become thinner, the space for gas and coolant flow also decreases, leading to poor coolant flow, which can affect battery performance and the heat dissipation effect of the bipolar plates.

[0004] Therefore, how to improve the heat dissipation effect of bipolar plates is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] The purpose of this invention is to provide a bipolar plate for a fuel cell with improved heat dissipation. Another purpose of this invention is to provide a fuel cell including the aforementioned bipolar plate.

[0006] This application provides a bipolar plate for a fuel cell, comprising:

[0007] Anode single plate;

[0008] Cathode plate;

[0009] A cooling layer is located between the anode plate and the cathode plate. The cooling layer includes an inlet distribution area, an outlet distribution area, and a cooling layer reaction area connecting the inlet distribution area and the outlet distribution area. The inlet distribution area forms ridges of adjacent coolant flow channels that are radially distributed along the coolant flow direction. The width of the outlet distribution area gradually increases along the coolant flow direction.

[0010] Optionally, in the bipolar plate of the above-mentioned fuel cell, the coolant channels in the reaction region of the cooling layer are arranged sequentially along the width direction, and the width of all the coolant channels gradually decreases from both sides to the center along the width direction.

[0011] Optionally, in the bipolar plates of the above-mentioned fuel cell, the groove width of all the coolant flow channels is greater than or equal to 0.9 mm and less than or equal to 1.4 mm;

[0012] And / or all of the aforementioned coolant channels are symmetrically distributed along the width of the channel.

[0013] Optionally, in the bipolar plates of the aforementioned fuel cell, the liquid distribution area forms a zigzag distribution along the coolant flow direction, with the ridges of adjacent coolant flow channels forming the ridges.

[0014] Optionally, in the bipolar plate of the above-mentioned fuel cell, the depth of the grooves in the liquid inlet distribution area, the liquid outlet distribution area, and the cooling layer reaction area is 0.1mm-0.25mm.

[0015] Optionally, in the bipolar plates of the above-mentioned fuel cell, the air inlet distribution area and the air outlet distribution area of ​​the anode plate and / or the air inlet distribution area and the air outlet distribution area of ​​the cathode plate are flow guiding areas, and the flow guiding areas include columnar flow guiding elements and strip flow guiding elements.

[0016] Optionally, in the bipolar plates of the above-mentioned fuel cell, the gas flow channels of the gas reaction region of the anode plate and / or the gas reaction region of the cathode plate are arranged in an S-shape; along the stacking direction of the anode plate, the cooling layer and the cathode plate, the cross-sectional area of ​​the gas flow channel of the gas reaction region is the cross-sectional area of ​​the flow channel formed between two adjacent strip guides.

[0017] Optionally, in the bipolar plates of the above-described fuel cell, the anode plate comprises:

[0018] Anode metal layer;

[0019] An anode carbon material layer is disposed on a first side and a second side opposite to the anode metal layer, and a cooling layer is disposed on the second side of the anode carbon material layer.

[0020] The first ridge forms the anode inlet distribution area, the anode reaction area flow field, and the anode outlet distribution area of ​​the anode plate between adjacent first ridges.

[0021] Optionally, in the bipolar plates of the above-described fuel cell, the cathode plate comprises:

[0022] Cathode metal layer;

[0023] A cathode carbon material layer is disposed on a first side and a second side opposite to the cathode metal layer, and a cooling layer is disposed on the second side of the cathode carbon material layer.

[0024] The second ridge forms the cathode inlet distribution area, the cathode reaction area flow field, and the cathode outlet distribution area of ​​the cathode plate between adjacent second ridges.

[0025] This application provides a fuel cell including a bipolar plate, wherein the bipolar plate is the bipolar plate of any of the above-described fuel cells.

[0026] In the above technical solution, the bipolar plate of the fuel cell provided by this utility model includes an anode plate, a cathode plate and a cooling layer. The cooling layer is located between the anode plate and the cathode plate. The cooling layer includes an inlet distribution area, an outlet distribution area and a cooling layer reaction area connecting the inlet distribution area and the outlet distribution area. The ridges of the adjacent coolant flow channels formed by the inlet distribution area are radially distributed along the coolant flow direction. The width of the outlet distribution area gradually increases along the coolant flow direction.

[0027] As described above, in the bipolar plate of the fuel cell provided in this application, the ridges of adjacent coolant flow channels in the liquid inlet distribution area are radially distributed along the coolant flow direction, making the coolant distribution in the cooling area more uniform. The width of the channel in the liquid outlet distribution area gradually increases along the coolant flow direction, facilitating the collection and discharge of coolant. Therefore, the heat dissipation effect of the bipolar plate of the fuel cell provided in this application is improved. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 An exploded view of the bipolar plate provided in an embodiment of this utility model;

[0030] Figure 2 This is a schematic diagram of the structure of the cooling layer provided in an embodiment of the present utility model;

[0031] Figure 3 for Figure 2 Enlarged view of part A of the cooling layer shown;

[0032] Figure 4 This is a schematic diagram of the structure of the anode single plate provided in an embodiment of the present utility model;

[0033] Figure 5This is a schematic diagram of the structure of the cathode plate provided in an embodiment of the present utility model;

[0034] Figure 6 for Figure 5 Enlarged view of part B of the cathode plate shown;

[0035] Figure 7 A cross-sectional view of the bipolar plate provided in an embodiment of this utility model;

[0036] Figure 8 A schematic diagram of the temperature between the flow channels at the middle cross section of the cooling layer provided in this embodiment of the utility model;

[0037] Figure 9 This is a schematic diagram of the coolant flow velocity between the channels at the middle cross section of the cooling layer provided in this embodiment of the utility model.

[0038] Figure 10 A schematic diagram of the gas flow velocity between the channels at the middle cross section of the cathode plate provided in this embodiment of the utility model;

[0039] Figure 11 This is a schematic diagram of the gas pressure between the flow channels at the middle cross section of the cathode plate provided in this embodiment of the utility model.

[0040] in Figure 1-7 In the middle: 1-Second sealing strip, 2-First sealing strip, 3-Anode plate, 4-Cathode plate, 5-Cooling layer reaction area, 6-Liquid inlet distribution area, 7-Liquid outlet distribution area, 8-Anode reaction area flow field, 9-Anode gas inlet distribution area, 10-Anode gas outlet distribution area, 11-Cathode reaction area flow field, 12-Cathode gas inlet distribution area, 13-Cathode gas outlet distribution area, 14-Cathode gas inlet, 15-Cathode gas outlet, 16-Anode gas inlet, 17-Anode gas outlet, 1 8-Coolant inlet, 19-Coolant outlet, 20-Coolant flow channel, 21-Third ridge, 22-Anode inlet direct connection channel, 23-Anode outlet direct connection channel, 24-Cathode inlet direct connection channel, 25-Cathode outlet direct connection channel, 26-Anode single plate sealing groove, 27-Cathode single plate sealing groove, 28-Cathode reaction gas flow channel, 29-Second ridge, 30-Anode metal layer, 31-First side, 32-Second side, 33-Cathode metal layer, 34-Second side, 35-First side, 36-First ridge. Detailed Implementation

[0041] The core of this invention is to provide a bipolar plate for a fuel cell, which improves heat dissipation. Another core aspect of this invention is to provide a fuel cell including the aforementioned bipolar plate.

[0042] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0043] Please refer to Figure 1 In one specific embodiment, the bipolar plate of the fuel cell provided by this utility model includes an anode plate 3, a cathode plate 4, and a cooling layer. The cooling layer is located between the anode plate 3 and the cathode plate 4, wherein the anode plate 3 and the cathode plate 4 are not limited to being bonded together by means of adhesive bonding, sintering, or other methods. A first sealing strip 2 is provided on the side of the anode plate 3 away from the cooling layer. Specifically, the anode plate 3 has an anode plate sealing groove 26 for accommodating the first sealing strip 2. A second sealing strip 1 is provided on the side of the cathode plate 4 away from the cooling layer, and the cathode plate 4 has a cathode plate sealing groove 27 for accommodating the second sealing strip 1. The width of the sealing grooves (anode plate sealing groove 26 and cathode plate sealing groove 27) for installing the first sealing strip 2 and the second sealing strip 1 is not limited to 0.8mm, 1.0mm, 1.5mm, or 2mm. The width of the first sealing strip 2 and the second sealing strip 1 is not limited to 0.65mm, 0.85mm, 1.35mm, or 1.85mm.

[0044] Among them, the substrate in the anode plate 3 can be the anode metal layer 30, and the substrate in the cathode plate 4 can be the cathode metal layer 33. Specifically, the substrate can be any conductive material such as stainless steel, titanium, aluminum, nickel, gold, platinum, etc. In order to reduce the thickness of the bipolar plate, the substrate can be a material of 0.03mm-0.08mm.

[0045] like Figure 2 As shown, the cooling layer includes an inlet distribution area 6, an outlet distribution area 7, and a cooling layer reaction area 5 connecting the inlet distribution area 6 and the outlet distribution area 7. The inlet distribution area 6 forms ridges of adjacent coolant flow channels 20, which are radially distributed along the coolant flow direction. For example, the coolant inlet 18 is located in the middle of the inlet distribution area 6, and the coolant sprayed into the inlet distribution area 6 forms a fan shape. The width of the outlet distribution area 7 gradually increases along the coolant flow direction. At the outlet distribution area 7, the outlet has a wider groove, and the specific size can be selected according to actual needs.

[0046] As described above, in the bipolar plate of the fuel cell provided in this specific embodiment, the inlet distribution region 6 forms ridges of adjacent coolant flow channels 20 that are radially distributed along the coolant flow direction, making the coolant distribution in the cooling area more uniform. The width of the outlet distribution region 7 gradually increases along the coolant flow direction, facilitating the collection and discharge of coolant. Therefore, the heat dissipation effect of the bipolar plate of the fuel cell provided in this application is improved.

[0047] In one specific embodiment, the coolant channels 20 in the cooling layer reaction zone 5 are arranged sequentially along the width direction, and the width of all coolant channels 20 gradually decreases from both sides towards the center. Specifically, the width of all coolant channels 20 decreases sequentially from both sides towards the center, and the widths of adjacent coolant channels 20 are not the same. Alternatively, some adjacent coolant channels 20 may have the same width, with the width changing at intervals.

[0048] Specifically, the cooling layer reaction zone 5 forms a cooling zone flow field. The width of the groove in the cooling layer reaction zone 5 is greater than or equal to 0.9 mm and less than or equal to 1.4 mm, with 2-3 grooves per group (adjusted to a symmetrical left-right shape based on the actual design of the electrode width). The groove width gradually decreases as it moves towards the center of the anode plate 3 and cathode plate 4. For example... Figure 3 As shown, this is an enlarged view of the cooling layer reaction zone 5. The tank width is reduced according to the arithmetic sequence An = 0.95 - 0.05(n-1) (the width remains unchanged after four sets of data, and the reduction ratio and the number of changes can be adjusted according to the situation) until it reaches the center position of the anode plate 3 and the cathode plate 4. The ridge width in the cooling layer reaction zone 5 is 1mm-1.5mm, and the tank depth is 0.1mm-0.25mm.

[0049] like Figure 3 As shown, in one specific embodiment, the groove width of all coolant flow channels 20 is less than or equal to 1.4 mm and greater than or equal to 0.9 mm, for example, the groove width of all coolant flow channels 20 is less than or equal to 1.0 mm.

[0050] Specifically, all coolant channels 20 are symmetrically distributed along the width of the channel, and the coolant channels 20 can be straight channels. The cooling layer reaction zone 5, the inlet distribution zone 6, and the outlet distribution zone 7 form a flow field, and the surface of the flow field is not limited to sprayed or screen-printed conductive paste. The inlet distribution zone 6 has a coolant inlet 18 at its end, and the outlet distribution zone 7 has a coolant outlet 19 at its end. The coolant inlet 18 and the coolant outlet 19 can be respectively located on the upper and lower sides of the bipolar plate. Figure 8 The image shows the coolant temperature at the corresponding cross-sectional positions of each coolant channel 20 arranged sequentially at the location of the reaction zone 5 of the cooling layer. Figure 9 The coolant flow rate is shown at the corresponding cross-sectional position of each coolant channel 20 arranged sequentially at the location of the cooling layer reaction zone 5. Specifically, the higher the coolant flow rate in the corresponding coolant channel 20, the lower the coolant temperature.

[0051] In the flow field design of the coolant inlet and outlet distribution area, in order to make the coolant distribution in the cooling area more uniform, such as Figure 2As shown, the flow channels in the inlet distribution area 6 are arranged in a herringbone pattern. The angle between the coolant flow direction in the flow channels of the inlet distribution area 6 and the coolant flow direction at the coolant inlet 18 ranges from 30° to 60°. Specifically, the length of each segment in the flow channels of the inlet distribution area 6 and the outlet distribution area 7 is not limited to 2mm, 4mm, 6mm, or 8mm, and the ridge width of the flow channels in the inlet distribution area 6 and the outlet distribution area 7 is set to 1mm-1.5mm. Specifically, the groove width is adjusted irregularly according to the actual conditions.

[0052] At point 7 in the coolant distribution area, to prevent coolant concentration, the outlet channel width is set relatively wide, with a depth of 0.1mm-0.25mm, selected according to actual needs. The coolant distribution area is located near the reaction zone, where the channel width is relatively narrower and the fluid velocity is higher. This also allows for further mixing of the fluid flowing from the upper and lower reaction zones with the fluid in the middle reaction zone, reducing temperature and preventing concentration. As the coolant approaches outlet 19, the overall temperature stabilizes, requiring the fluid to flow out quickly. Therefore, the number of ridges is reduced and the channel width is increased near outlet 19 to ensure smooth fluid flow.

[0053] This patent primarily focuses on the design of the bipolar plate structure, coolant distribution, flow field in the cooling zone, and the anode and cathode gas distribution and reaction zones. In the bipolar plate structure, the anode and cathode gas inlets are located on the upper and lower sides of the proton exchange membrane, respectively, while the coolant inlet 18 is located on either the upper or lower side of the proton exchange membrane. For details, see [link to patent details]. Figure 1 In the cooling layer flow field design, to ensure a more uniform coolant distribution in the cooling area, a herringbone design is adopted for the coolant inlet and outlet distribution areas. The width of the cooling zone grooves is less than or equal to 1.4-0.9 mm, with 2-3 grooves per group, meaning that adjacent two or three grooves have equal widths (adjusted to a symmetrical form on both sides according to the actual design of the electrode width). As the grooves move towards the center of the bipolar plates, the groove width gradually decreases according to an arithmetic progression An = 0.95-0.05(n-1) (after four groups of data, the width remains constant, and the reduction ratio and number of changes can be adjusted as needed) until the center of the bipolar plates is reached, ensuring symmetry on both sides of the bipolar plate cooling layer groove width. In the cooling layer design, the width of the third ridge 21 is 1 mm-1.5 mm, and the coolant flow channel 20 formed by the third ridge 21 is 0.1 mm-0.25 mm deep.

[0054] like Figure 2 As shown, in one specific embodiment, the ridges of the adjacent coolant flow channels 20 in the liquid distribution area 7 are distributed in a zigzag pattern along the coolant flow direction. Specifically, the third ridge 21 at the location of the liquid distribution area 7 is linearly arranged, and the included angle between adjacent third ridges 21 is an obtuse angle.

[0055] In one specific embodiment, the depth of the tank in the liquid inlet distribution area 6, the liquid outlet distribution area 7, and the cooling layer reaction area 5 is 0.1mm-0.25mm. Reducing the bipolar plate thickness, achieved by decreasing the height of the cooling layer, reduces the bipolar plate weight and increases the volumetric power density of the fuel cell.

[0056] In one specific embodiment, the anode inlet distribution area 9 of the anode plate 3, the anode outlet distribution area 10 of the anode plate 3, the cathode inlet distribution area 12 of the cathode plate 4, and the cathode outlet distribution area 13 of the cathode plate 4 are all flow guiding areas. Specifically, at least one of them is a flow guiding area, and the flow guiding areas on the anode plate 3 and the cathode plate 4 can have the same shape. The flow guiding areas include columnar flow guiding elements and strip-shaped flow guiding elements. Specifically, the columnar flow guiding elements can be cylindrical structures. Figure 4 As shown, specifically, the anode reaction zone flow field 8, the anode inlet distribution zone 9, and the anode outlet distribution zone 10 are attached to the front side of the substrate of the anode plate 3. The anode gas inlet 16 and the anode gas outlet 17 on the anode plate 3 are located at opposite ends of the anode plate 3, preferably at diagonally opposite corners. In use, gas enters the anode inlet distribution zone 9 through the anode gas inlet 16 and the anode inlet direct connection channel 22. After reacting in the anode reaction zone flow field 8, it enters the anode outlet distribution zone 10, passes through the anode outlet direct connection channel 23, and is finally discharged through the anode gas outlet 17. The above-mentioned attachment process is not limited to spraying and screen printing. A strip shape is used in the anode inlet distribution zone 9. The groove width is widened at this position to reduce gas flow resistance. The groove width of the distribution zone near the inlet is relatively wide, which roughly diverts the incoming fluid and reduces flow resistance. Subsequently, the groove width of the distribution zone gradually decreases, resulting in a more detailed and uniform distribution of the fluid.

[0057] like Figure 5As shown, the slot widths of the anode inlet distribution area 9 and the anode outlet distribution area 10 cannot be the same as the slot widths of the anode reaction area flow field 8 and the cathode reaction area flow field 11. Their functions differ. The slots in the anode inlet distribution area 9 and the anode outlet distribution area 10 are designed to ensure more uniform fluid flow into the reaction zone, while the slots in the anode reaction area flow field 8 and the cathode reaction area flow field 11 are designed to ensure more uniform fluid flow and increase reaction efficiency. Because of their different roles in the bipolar plate, the anode reaction area flow field 8 and the cathode reaction area flow field 11 require relatively smaller slot widths. The slots in the anode inlet distribution area 9 and the anode outlet distribution area 10 only need to allow fluid to flow towards the channel farther from the inlet, ensuring rapid gas entry into the distribution zone. The columnar guide expands the gas flow direction, allowing for more uniform gas flow into the strip guide position. The strip guide increases gas turbulence, making the gas reach the inlet of the anode reaction area flow field 8 and the cathode reaction area flow field 11 more evenly. The angle formed between the airflow direction within adjacent strip-shaped guide members and the airflow direction of the corresponding anode gas inlet 16 and cathode gas inlet 14 is 30°-60°, or less than 30°, or greater than 60°, preferably less than 90°. For example, the angles formed between the airflow direction within adjacent strip-shaped guide members and the airflow direction of the corresponding anode gas inlet 16 and cathode gas inlet 14 are 30°, 45°, and 60°. Enlarging the width of the strip-shaped distribution area at the edge of the gas outlet allows the gas to flow out rapidly.

[0058] In one specific embodiment, the gas flow channels in the gas reaction regions of the anode plate 3 and / or the cathode plate 4 are arranged in an S-shape; along the stacking direction of the anode plate 3, the cooling layer, and the cathode plate 4, this ensures increased gas disturbance and sufficient reaction. Specifically, the flow field formed by the S-shaped gas flow channels does not limit the angle of the gas at the S-shaped bend to 30°, 45°, or 60°. The groove depth and ridge width in the flow field can be consistent with the flow field design of the cooling layer.

[0059] Figure 5 The diagram shows the flow field on the cathode plate 4. The front side of the cathode plate 4 has a cathode reaction area flow field 11, a cathode gas inlet distribution area 12, and a cathode gas outlet distribution area 13. The attachment process is not limited to spraying and screen printing. The rest is the same as the anode plate 3, and will not be described in detail here.

[0060] Specifically, the cathode gas inlet 14 and cathode gas outlet 15 on the cathode plate 4 are located at opposite ends of the cathode plate 4, preferably at diagonally opposite corners. In use, gas enters the cathode reaction region flow field 11 through the cathode gas inlet 14 and the cathode inlet direct connection channel 24. After reacting in the cathode reaction region flow field 11, it enters the cathode outlet distribution region 13, then passes through the cathode outlet direct connection channel 25, and finally exits through the cathode gas outlet 15. Figure 10 The diagram shows the gas flow velocity at each cross-sectional position of the gas flow channel arranged sequentially at position 11 in the cathode reaction region. Figure 11 A schematic diagram of the pressure at the cross-sectional positions of each gas channel set sequentially at position 11 in the cathode reaction region flow field.

[0061] In practical operation, the anode inlet distribution region 9, anode outlet distribution region 10, cathode inlet distribution region 12, and cathode outlet distribution region 13 are selected in a mixed lattice configuration (using a lattice pattern near the reaction zone). This reduces gas flow resistance, allowing gas to flow quickly to the reaction zone, and also increases gas turbulence, resulting in more uniform gas flow to the inlet of the anode reaction zone flow field 8 and the cathode reaction zone flow field 11. The increased gas turbulence in the anode reaction zone flow field 8 and the cathode reaction zone flow field 11 ensures a more complete reaction.

[0062] like Figure 7 As shown, in one specific embodiment, the anode plate 3 includes an anode metal layer 30, an anode carbon material layer, and a first ridge 36. The anode carbon material layer is disposed on a first side 31 and a second side 32 opposite to the anode metal layer 30, and a cooling layer is disposed on the second side 32 of the anode carbon material layer. The first ridge 36 is disposed on the first side 31, and adjacent first ridges 36 form the anode inlet distribution region 9, the anode reaction region flow field 8, and the anode outlet distribution region 10 of the anode plate 3.

[0063] like Figure 7 As shown, in one specific embodiment, the cathode plate 4 includes a cathode metal layer 33, a cathode carbon material layer, and a second ridge 29. The cathode carbon material layer is disposed on a first side 35 and a second side 34 opposite to the cathode metal layer 33, and a cooling layer is disposed on the second side 34 of the cathode carbon material layer. Figure 6 As shown, a cathode reaction gas flow channel 28 is formed between adjacent second ridges 29.

[0064] The second ridge 29 is disposed on the first side, and the cathode gas inlet distribution area 12, the cathode reaction area flow field 11 and the cathode gas outlet distribution area 13 of the cathode plate 4 are formed between adjacent second ridges 29.

[0065] The addition of a carbon material layer in this application can reduce the weight of the bipolar plate and connect the ridges forming the coolant flow channel 20 and the reactive gas flow channel. The cathode metal layer 33 and the anode metal layer 30 can increase the flexibility of the bipolar plate. The carbon material ridges can increase the gas diffusion capacity and increase the flexibility of the bipolar plate flow field preparation. The carbon material in this invention can be any type of carbon with good conductivity, not limited to graphene, carbon fiber, acetylene black, carbon nanotubes, or mixtures thereof. In this invention, because the gas molecules flowing within the cathode plate 4 and the anode plate 3 are of different sizes, and the coolant and gas have different requirements for the porosity of the carbon material, the carbon material of the ridges, the carbon material on both sides of the cathode metal layer 33 and the anode metal layer 30, and the carbon slurry formulation can be the same or different. The overall ridge width is 1mm-1.5mm. Various groove widths can be set according to actual needs; the groove width is not limited to 0.8mm, 1mm, 1.5mm, 2mm, or 3mm.

[0066] Simulation results for the velocity and pressure differences between the flow channels at the cathode's mid-section show a velocity difference of 10% and a pressure difference of 4.06%, meeting the design requirements. This structure improves air transport, which is beneficial for subsequent removal of liquid water generated in the flow channels and increases the mass transfer efficiency of the fuel cell.

[0067] In summary, the bipolar plate flow channel provided in this application can be fabricated using flexible flow channel design processes such as carbon-based conductive material slurry spraying and screen printing. The feasibility of the bipolar plate flow field in this application was further verified through simulation technology. In the simulation, the fluid is incompressible, and the fluid density does not change with time and can be considered a constant. The relative velocity between the solid surface and the fluid is zero, satisfying the no-slip velocity boundary condition. Viscous losses of the fluid and channel walls are not considered; the medium in the channels (gas flow channel and coolant flow channel) exhibits the characteristics of a continuous medium, and the heat flux distribution in the heating region is uniform.

[0068] This application reduces the depth of the cooling layer and gas flow field groove in ultra-thin fuel cell bipolar plates. To ensure uniform gas flow and coolant distribution, it designs a regularly gradient distribution area, a regularly gradient cooling layer, and gas flow channels. To improve the flexibility of bipolar plate flow field design and gas diffusion capability, a multi-layer bipolar plate structure can be stacked. The above design improves the mass power density of fuel cells and facilitates the market application of fuel cells.

[0069] The simulation results of the temperature and velocity differences between the flow channels at the middle section of the cooling layer in this application show that the temperature difference between the flow channels is 0.05%, and the velocity difference is 7.44%, which meets the design requirements of bipolar plates. The structural design of the cooling layer can effectively and rationally distribute the flow rate, enhance the uniformity of the cooling medium distribution in the flow field, make the overall temperature distribution of the cooling layer more uniform, and effectively improve the heat dissipation capacity of the cooling layer.

[0070] This application provides a fuel cell including a bipolar plate, wherein the bipolar plate is any of the aforementioned fuel cell bipolar plates. The specific structure of the bipolar plate has been described above; this application includes the aforementioned bipolar plate and also achieves the aforementioned technical effects.

[0071] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0072] The above description of the disclosed embodiments enables those skilled in the art to make or use the present 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 present invention. Therefore, the present 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 fuel cell, characterized in that, include: Anode single plate (3); Cathode plate (4); The cooling layer is located between the anode plate (3) and the cathode plate (4). The cooling layer includes an inlet distribution area (6), an outlet distribution area (7), and a cooling layer reaction area (5) connecting the inlet distribution area (6) and the outlet distribution area (7). The inlet distribution area (6) forms ridges of adjacent coolant channels that are radially distributed along the coolant flow direction. The width of the outlet distribution area (7) gradually increases along the coolant flow direction.

2. The bipolar plate of the fuel cell according to claim 1, characterized in that, The coolant channels in the reaction zone (5) of the cooling layer are arranged sequentially along the width of the channel, and the width of all the coolant channels gradually decreases from both sides to the center along the width of the channel.

3. The bipolar plate of the fuel cell according to claim 2, characterized in that, The width of all said coolant flow channels is greater than or equal to 0.9 mm and less than or equal to 1.4 mm; And / or all of the aforementioned coolant channels are symmetrically distributed along the width of the channel.

4. The bipolar plate of the fuel cell according to claim 1, characterized in that, The liquid distribution area (7) forms a zigzag distribution along the direction of coolant flow, with the ridges of adjacent coolant channels.

5. The bipolar plate of the fuel cell according to claim 1, characterized in that, The depth of the inlet distribution area (6), the outlet distribution area (7), and the cooling layer reaction area (5) is 0.1mm-0.25mm.

6. The bipolar plate of the fuel cell according to claim 1, characterized in that, The anode inlet distribution area (9) and anode outlet distribution area (10) of the anode plate (3) and / or the cathode inlet distribution area (12) and cathode outlet distribution area (13) of the cathode plate (4) are flow guiding areas, and the flow guiding areas include column-shaped flow guiding elements and strip-shaped flow guiding elements.

7. The bipolar plate of the fuel cell according to claim 6, characterized in that, The gas flow channels of the gas reaction region of the anode plate (3) and / or the gas reaction region of the cathode plate (4) are arranged in an S-shape; along the stacking direction of the anode plate (3), the cooling layer and the cathode plate (4), the cross-sectional area of ​​the gas flow channel of the gas reaction region is the cross-sectional area of ​​the flow channel formed between two adjacent strip guides.

8. The bipolar plate of the fuel cell according to claim 1, characterized in that, The anode plate (3) includes: Anode metal layer (30); An anode carbon material layer is disposed on a first side and a second side opposite to the anode metal layer (30), and a cooling layer is disposed on the second side of the anode carbon material layer. The first ridge (36) is disposed on the first side, and the anode inlet distribution area (9), the anode reaction area flow field (8) and the anode outlet distribution area (10) of the anode plate (3) are formed between adjacent first ridges (36).

9. The bipolar plate of the fuel cell according to claim 1, characterized in that, The cathode plate (4) includes: Cathode metal layer (33); A cathode carbon material layer is disposed on a first side and a second side opposite to the cathode metal layer (33), and a cooling layer is disposed on the second side of the cathode carbon material layer. The second ridge (29) is disposed on the first side, and the cathode gas inlet distribution area (12), cathode reaction area flow field (11) and cathode gas outlet distribution area (13) of the cathode plate (4) are formed between adjacent second ridges (29).

10. A fuel cell, comprising bipolar plates, characterized in that, The bipolar plate is the bipolar plate of the fuel cell according to any one of claims 1-9.

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