A fuel cell bipolar plate based on porous media flow channels
By using porous media flow channel design and powder metallurgy process, the problems of uneven fluid distribution and contact resistance in fuel cell bipolar plates were solved, achieving a more uniform gas and coolant distribution, improving reaction efficiency and stability, while reducing manufacturing difficulty and cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI HYTEKOCEAN CO LTD
- Filing Date
- 2025-08-27
- Publication Date
- 2026-07-21
AI Technical Summary
Existing fuel cell bipolar plates suffer from problems such as uneven fluid distribution, localized reactant depletion/retention, difficulties in hydrothermal management, structural complexity and high cost, and uneven contact resistance and pressure distribution.
A porous medium flow channel design is adopted, and a porous medium layer and a contact layer are sintered through powder metallurgy to form a uniform gas and coolant channel, thereby improving the uniformity of fluid distribution and optimizing the flow channel structure to reduce contact resistance and pressure concentration.
This achieves uniform distribution of gas and coolant, reduces contact resistance and pressure distribution unevenness, improves reaction efficiency and system stability, and reduces manufacturing complexity and cost.
Smart Images
Figure CN224537070U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of fuel cells, and more particularly to a fuel cell bipolar plate based on a porous media flow channel. Background Technology
[0002] The bipolar plate of a fuel cell, also known as a flow field plate, is the "skeleton" of the fuel cell stack. It is stacked with the membrane electrode assembly (MEA) to form the stack. In the fuel cell, it plays a role in supporting the fuel cell, collecting current, providing channels for the coolant, and separating oxygen and hydrogen. Existing fuel cell bipolar plates are usually formed into grooves or serpentine flow channels on metal, graphite, or composite material substrates by machining, stamping, or etching to guide the flow of reactant gases such as hydrogen / oxygen and coolant.
[0003] This traditional flow channel design has the following inherent drawbacks: 1. Uneven fluid distribution: Uneven flow velocity and pressure drop distribution are prone to occur at the inlet and outlet of the flow channel, the center and edge of the flow channel, and the corner of the flow channel, resulting in uneven distribution of reactant gas or coolant on the electrode surface (gas diffusion layer) or in the cooling channel. 2. Local shortage / retention of reactants: Uneven distribution may lead to insufficient supply of reactants in local areas of the electrode (affecting performance) or retention of liquid water / heat (affecting stability, easily causing flooding or hot spots); 3. Water and heat management challenges: Traditional flow channels have limited capacity to discharge liquid water, and uneven distribution of coolant can affect the uniform removal of heat; 4. Structural complexity and cost: The machining of precise and complex flow channels (especially three-dimensional flow channels) increases manufacturing difficulty and cost; 5. Contact resistance and pressure distribution: The ridge of the flow channel is in contact with the gas diffusion layer, while the groove area is not in contact, which may lead to uneven contact resistance and pressure distribution. Utility Model Content
[0004] In order to improve the uniformity of hydrogen, oxygen and coolant distribution, reduce structural complexity and manufacturing cost, and make the contact resistance and pressure distribution uniform, this application provides a fuel cell bipolar plate based on porous media flow channels.
[0005] The technical solution for a fuel cell bipolar plate based on a porous medium flow channel provided in this application is as follows: A bipolar plate for a fuel cell based on a porous medium flow channel includes a hydrogen-side partition, an oxygen-side partition, a first membrane electrode, and a second membrane electrode. The first and second membrane electrodes are arranged in parallel. The hydrogen-side partition and the oxygen-side partition are arranged in parallel between the first and second membrane electrodes. A hydrogen channel is formed between the hydrogen-side partition and the first membrane electrode. An oxygen channel is formed between the oxygen-side partition and the second membrane electrode. A coolant channel is formed between the hydrogen-side partition and the oxygen-side partition. A cooling-side porous medium layer is provided between the oxygen-side partition and the hydrogen-side partition; An oxygen-side porous dielectric layer is provided on the side of the oxygen-side partition away from the hydrogen-side partition, and an oxygen-side contact layer is provided on the surface of the oxygen-side porous dielectric layer. The oxygen-side contact layer is located between the second membrane electrode and the oxygen-side porous dielectric layer. A hydrogen-side porous dielectric layer is provided on the side of the hydrogen-side separator away from the oxygen-side separator, and a hydrogen-side contact layer is provided on the surface of the hydrogen-side porous dielectric layer. The hydrogen-side contact layer is located between the first membrane electrode and the hydrogen-side porous dielectric layer.
[0006] Preferably, the porous medium layer on the cooling side is formed by sintering S31603 powder with an average particle size of 100μm through powder metallurgy process, and the porous medium layer on the cooling side has a thickness of 0.8mm and a porosity of 50%.
[0007] Preferably, the oxygen-side porous media layer and the hydrogen-side porous media layer are both sintered from S31603 powder with an average particle size of 50μm through a powder metallurgy process, and the thickness of the oxygen-side porous media layer and the hydrogen-side porous media layer is 1mm and the porosity is 60%.
[0008] Preferably, the oxygen-side contact layer and the hydrogen-side contact layer are both sintered from S31603 powder with an average particle size of 20 μm using a powder metallurgy process, and the thickness of the oxygen-side contact layer and the hydrogen-side contact layer is 0.2 mm and the porosity is 70%.
[0009] Preferably, both the oxygen-side partition and the hydrogen-side partition are made of S31603 plate with a thickness of 0.2 mm.
[0010] Preferably, the porous medium layer on the cooling side is formed by sintering graphite LC300-99.90 with an average particle size of 100μm through powder metallurgy, and the porous medium layer on the cooling side has a thickness of 0.8mm and a porosity of 50%.
[0011] Preferably, both the hydrogen-side porous media layer and the oxygen-side porous media layer are sintered from graphite LC300-99.90 fine powder with an average particle size of 40μm through powder metallurgy, and the thickness of the hydrogen-side porous media layer and the oxygen-side porous media layer is 1mm and the porosity is 60%.
[0012] Preferably, both the hydrogen-side contact layer and the oxygen-side contact layer are formed by sintering LC300-99.90 fine powder with a particle size of 15μm using a powder metallurgy process, and the thickness of the hydrogen-side contact layer and the oxygen-side contact layer is 0.2mm, with a porosity of 70%. Preferably, both the oxygen-side partition and the hydrogen-side partition are 1.5 mm thick graphite LC300-99.90 plates. Attached Figure Description
[0013] Figure 1 This is a schematic diagram illustrating the internal structure of a fuel cell bipolar plate, as shown in an embodiment of this application.
[0014] Explanation of reference numerals in the attached figures: 1. Oxygen-side contact layer; 2. Oxygen-side porous media layer; 3. Oxygen-side partition; 4. Cooling-side porous media layer; 5. Hydrogen-side partition; 6. Hydrogen-side porous media layer; 7. Hydrogen-side contact layer; 8. First membrane electrode; 9. Second membrane electrode. Detailed Implementation
[0015] The following combination Figure 1 This application will be described in further detail.
[0016] Example 1 This application discloses a fuel cell bipolar plate based on a porous media flow channel. (Refer to...) Figure 1 It mainly includes a hydrogen-side partition 5, an oxygen-side partition 3, a first membrane electrode 8, and a second membrane electrode 9. The first membrane electrode 8 and the second membrane electrode 9 are arranged in parallel. The hydrogen-side partition 5 and the oxygen-side partition 3 are arranged in parallel between the first membrane electrode 8 and the second membrane electrode 9. A coolant channel is formed between the hydrogen-side partition 5 and the oxygen-side partition 3. A hydrogen channel is formed between the hydrogen-side partition 5 and the first membrane electrode 8. An oxygen channel is formed between the oxygen-side partition 3 and the second membrane electrode 9.
[0017] An oxygen-side porous dielectric layer 2 is provided on the side of the oxygen-side partition 3 away from the hydrogen-side partition 5, and an oxygen-side contact layer 1 is provided on the surface of the oxygen-side porous dielectric layer 2. The oxygen-side contact layer 1 is located between the second membrane electrode 9 and the oxygen-side porous dielectric layer 2.
[0018] A hydrogen-side porous dielectric layer 6 is provided on the side of the hydrogen-side partition 5 away from the oxygen-side partition 3, and a hydrogen-side contact layer 7 is provided on the surface of the hydrogen-side porous dielectric layer 6. The hydrogen-side contact layer 7 is located between the first membrane electrode 8 and the hydrogen-side porous dielectric layer 6.
[0019] A cooling-side porous medium layer 4 is provided between the oxygen-side partition 3 and the hydrogen-side partition 5.
[0020] In this embodiment, both the oxygen-side partition 3 and the hydrogen-side partition 5 are made of S31603 plate with a thickness of 0.2mm, which serves as the main frame to support the entire component and also isolates the gas and coolant.
[0021] The cooling-side porous medium is formed by sintering S31603 powder with an average particle size of 100 μm through powder metallurgy. The thickness of the cooling-side porous medium layer 4 is 0.8 mm and the porosity is 50%. The oxygen-side porous medium layer 2 and the hydrogen-side porous medium layer 6 are both formed by sintering S31603 powder with an average particle size of 50 μm through powder metallurgy. The thickness of the oxygen-side porous medium layer 2 and the hydrogen-side porous medium layer 6 is 1 mm and the porosity is 60%. The oxygen-side contact layer 1 and the hydrogen-side contact layer 7 are both formed by sintering S31603 powder with an average particle size of 20 μm through powder metallurgy. The thickness of the oxygen-side contact layer 1 and the hydrogen-side contact layer 7 is 0.2 mm and the porosity is 70%.
[0022] The cooling-side porous media layer 4, the hydrogen-side porous media layer 6, the oxygen-side porous media layer 2, the hydrogen-side contact layer 7, and the oxygen-side contact layer 1 are all sintered under argon (or other inert gas) protection, with sintering temperatures between 900-1300℃ and sintering times of 3-4 hours. The porosity of the porous layers can be precisely controlled by powder particle size, pressing pressure, and sintering process parameters (time, temperature).
[0023] During fuel cell operation, oxygen enters the oxygen channel from the oxygen-side porous media layer 2, and hydrogen enters the hydrogen channel from the hydrogen-side porous media layer 6. Oxygen flows through the gaps between sintered particles in the oxygen-side porous media layer 2, and hydrogen flows through the gaps between sintered particles in the hydrogen-side porous media layer 6. The uniformly distributed porous structure significantly improves the uniformity of oxygen and hydrogen distribution. Since the porosity of both the oxygen-side and hydrogen-side porous media layers 2 and 6 is 60%, slightly higher than the volumetric density of the oxygen and hydrogen channels in conventional grooved flow channel structures, the optimized uniform flow channels greatly reduce the resistance to oxygen and hydrogen flow compared to conventional structures. Oxygen further flows to the oxygen-side contact layer 1, and hydrogen further flows to the hydrogen-side contact layer 7. Because the powder particles in the oxygen-side and hydrogen-side contact layers 1 and 6 have a diameter of 20 μm, the distribution of oxygen and hydrogen is more uniform, effectively improving the uniformity of contact between oxygen and the first membrane electrode 8, and between hydrogen and the second membrane electrode 9, thereby increasing gas utilization. The densely packed particles can disperse the pressure at the contact point between the bipolar plate and the first membrane electrode 8 and the second membrane electrode 9, reducing the damage caused by localized pressure concentration to the first membrane electrode 8 and the second membrane electrode 9. In addition, the densely packed particles make full contact with the first membrane electrode 8 and the second membrane electrode 9, greatly reducing the contact resistance.
[0024] When the coolant enters from the porous medium layer 4 on the cooling side and flows through the gaps between the sintered particles in the porous medium layer 4 on the cooling side, the uniformly distributed porous structure greatly improves the uniformity of coolant distribution. With a porosity of 50%, which is close to the volume ratio of the bipolar plate cooling channel of the conventional grooved channel structure, the optimized uniform channel structure greatly reduces the resistance of coolant flow in the channel compared with the conventional structure.
[0025] The heat exchange process between the coolant and the gas is as follows: coolant → porous media layer 4 on the cooling side → oxygen-side baffle 3 (or hydrogen-side baffle 5) → porous media layer 2 on the oxygen side (or porous media layer 6 on the hydrogen side) → oxygen-side contact layer 1 (or hydrogen-side contact layer 7) → oxygen (or hydrogen). Due to the special porous structure, the coolant is in a turbulent state from the moment it enters the porous media layer, which greatly improves its heat exchange efficiency with the powder particles in the porous media layer 4 on the cooling side, allowing it to more efficiently remove the heat transferred from the direction of the reacting gas.
[0026] Example 2 In this embodiment, both the oxygen-side partition 3 and the hydrogen-side partition 5 are made of 1.5 mm thick graphite LC300-99.90 plates; the oxygen-side porous media layer 2 and the hydrogen-side porous media layer 6 are both formed by sintering fine graphite LC300-99.90 powder with a particle size of 40 μm through powder metallurgy, with a thickness of 1 mm and a porosity of 60%; the oxygen-side contact layer 1 and the hydrogen-side contact layer 7 are both formed by sintering fine graphite LC300-99.90 powder with an average particle size of 15 μm through powder metallurgy, with a thickness of 0.2 mm and a porosity of 70%; the cooling-side porous media layer 4 is formed by sintering fine graphite LC300-99.90 powder with an average particle size of 100 μm through powder metallurgy, with a thickness of 0.8 mm and a porosity of 50%.
[0027] The sintering process is carried out under nitrogen (or other inert gas) protection at a temperature of 800-1200℃ for 24 hours. The porosity of the porous layer can be precisely controlled by the powder particle size, pressing pressure and sintering process parameters (temperature and time).
[0028] Example 3 In this embodiment, simple guide cavities or distribution cavities are designed in the areas near the inlet / outlet on both sides of the hydrogen-side partition 5 and the oxygen-side partition 3 to help the fluid enter / leave the porous media area more evenly.
[0029] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A fuel cell bipolar plate based on a porous media flow channel, characterized in that, It includes a hydrogen-side partition (5), an oxygen-side partition (3), a first membrane electrode (8), and a second membrane electrode (9). The first membrane electrode (8) and the second membrane electrode (9) are arranged in parallel. The hydrogen-side partition (5) and the oxygen-side partition (3) are arranged in parallel between the first membrane electrode (8) and the second membrane electrode (9). A hydrogen channel is formed between the hydrogen-side partition (5) and the first membrane electrode (8). An oxygen channel is formed between the oxygen-side partition (3) and the second membrane electrode (9). A coolant channel is formed between the hydrogen-side partition (5) and the oxygen-side partition (3). A cooling-side porous medium layer (4) is provided between the oxygen-side partition (3) and the hydrogen-side partition (5). The oxygen-side septum (3) is provided with an oxygen-side porous dielectric layer (2) on the side away from the hydrogen-side septum (5), and an oxygen-side contact layer (1) is provided on the surface of the oxygen-side porous dielectric layer (2). The oxygen-side contact layer (1) is located between the second membrane electrode (9) and the oxygen-side porous dielectric layer (2). The hydrogen-side diaphragm (5) is provided with a hydrogen-side porous medium layer (6) on the side away from the oxygen-side diaphragm (3), and a hydrogen-side contact layer (7) is provided on the surface of the hydrogen-side porous medium layer (6). The hydrogen-side contact layer (7) is located between the first membrane electrode (8) and the hydrogen-side porous medium layer (6).
2. The fuel cell bipolar plate based on a porous medium flow channel according to claim 1, characterized in that, The cooling side porous medium layer (4) is formed by sintering S31603 powder with an average particle size of 100μm through powder metallurgy process, and the thickness of the cooling side porous medium layer (4) is 0.8mm and the porosity is 50%.
3. A fuel cell bipolar plate based on a porous media flow channel according to claim 2, characterized in that, The oxygen-side porous media layer (2) and the hydrogen-side porous media layer (6) are both formed by sintering S31603 powder with an average particle size of 50μm through powder metallurgy process. The thickness of the oxygen-side porous media layer (2) and the hydrogen-side porous media layer (6) is 1mm and the porosity is 60%.
4. A fuel cell bipolar plate based on a porous medium flow channel according to claim 3, characterized in that, The oxygen-side contact layer (1) and the hydrogen-side contact layer (7) are both formed by sintering S31603 powder with an average particle size of 20μm through powder metallurgy process. The thickness of the oxygen-side contact layer (1) and the hydrogen-side contact layer (7) is 0.2mm and the porosity is 70%.
5. A fuel cell bipolar plate based on a porous media flow channel according to claim 3, characterized in that, Both the oxygen-side partition (3) and the hydrogen-side partition (5) are made of S31603 plate with a thickness of 0.2 mm.
6. A fuel cell bipolar plate based on a porous media flow channel according to claim 1, characterized in that, The cooling side porous media layer (4) is formed by sintering graphite LC300-99.90 with an average particle size of 100μm through powder metallurgy process, and the cooling side porous media layer (4) has a thickness of 0.8mm and a porosity of 50%.
7. A fuel cell bipolar plate based on a porous media flow channel according to claim 6, characterized in that, The hydrogen-side porous media layer (6) and the oxygen-side porous media layer (2) are both formed by sintering graphite LC300-99.90 fine powder with an average particle size of 40μm through powder metallurgy process. The hydrogen-side porous media layer (6) and the oxygen-side porous media layer (2) have a thickness of 1mm and a porosity of 60%.
8. A fuel cell bipolar plate based on a porous medium flow channel according to claim 7, characterized in that, The hydrogen-side contact layer (7) and the oxygen-side contact layer (1) are both formed by sintering LC300-99.90 fine powder with a particle size of 15μm through powder metallurgy process, and the hydrogen-side contact layer (7) and the oxygen-side contact layer (1) have a thickness of 0.2mm and a porosity of 70%.
9. A fuel cell bipolar plate based on a porous medium flow channel according to claim 8, characterized in that, Both the oxygen-side partition (3) and the hydrogen-side partition (5) are made of 1.5 mm thick graphite LC300-99.90 plates.