Cathode flow field plate of proton exchange membrane fuel cell for new energy vehicle
By designing a serpentine flow channel and baffles, the problems of uneven gas diffusion and liquid water accumulation in fuel cells were solved, resulting in higher mass transfer efficiency and longer battery life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHONGQING UNIVERSITY OF SCIENCE AND TECHNOLOGY
- Filing Date
- 2025-06-13
- Publication Date
- 2026-05-26
AI Technical Summary
The flow channel structure of existing proton exchange membrane fuel cells leads to uneven gas diffusion, low mass transfer efficiency, and easy accumulation and blockage of liquid water, which affects the performance and lifespan of the cells.
The design employs a serpentine flow channel, combined with improvements to the spoilers and drainage system. This includes serpentine ribs, L-shaped plates, 7-shaped plates, and arc-shaped plates forming a composite spoiler system. Multiple serpentine flow channels and drainage troughs are set up, and a gradient pressure field and three-dimensional drainage path are designed to promote uniform gas distribution and rapid drainage.
It improves the mass transfer efficiency of reactant gases, reduces gas leakage and flooding, enhances the electrochemical reaction rate and overall performance of fuel cells, and extends battery life.
Smart Images
Figure CN224288261U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of proton exchange membrane fuel cells, specifically a cathode flow field plate for a proton exchange membrane fuel cell used in new energy vehicles. Background Technology
[0002] Proton exchange membrane fuel cells (PEMFCs) are core power components of new energy vehicles, and their performance directly affects the vehicle's energy efficiency, range, and environmental performance. A PEMFC consists of membrane electrode assemblies (proton exchange membrane, catalyst layer, and gas diffusion layer), bipolar plates, and current collectors, among which the membrane electrode assemblies and bipolar plates determine the fuel cell's performance. The bipolar plates, as the core component of the fuel cell, play many important roles, including supporting the membrane electrode structure, separating hydrogen and oxygen, collecting electrons, conducting heat, providing hydrogen and oxygen channels, discharging water produced in the reaction, and providing coolant flow channels. The flow channel structure, in particular, determines the PEMFC's hydrothermal management, mass transport, and current density distribution, significantly impacting the fuel cell's overall performance. The reactant gases in the flow channel diffuse sequentially into the diffusion layer and catalyst layer. The diffusion rate and uniformity, i.e., the mass transfer capacity of the flow channel, directly affect the battery performance.
[0003] Common bipolar plate flow field structures are mainly divided into serpentine flow fields, parallel flow fields, and interdigitated flow fields. Among them, the serpentine flow field has a high gas velocity in the channel, which makes it easier to blow away the liquid water generated in the reaction, avoiding the accumulation and blockage of liquid water. However, its channel is too long and has many bends, which increases the pressure drop in the flow field, resulting in additional power loss.
[0004] The gas flow is mainly unidirectional and linear, with insufficient lateral and vertical disturbances, making it difficult to form forced convection. As a result, the reactant gas cannot enter the gas diffusion layer and the catalyst layer uniformly, leading to low mass transfer efficiency.
[0005] Furthermore, existing flow field structures typically lack a systematic drainage path, relying solely on a single drainage hole or natural gravity for drainage. This can easily lead to blockage of the flow channels due to the accumulation of liquid water, often causing flooding. This can cover the surface of the gas diffusion layer, hindering the transport of reactive gases, reducing battery performance, and shortening its lifespan. Utility Model Content
[0006] This invention aims to provide a cathode flow field plate for proton exchange membrane fuel cells used in new energy vehicles. This solution addresses issues such as gas leakage, water flooding and blockage, and insufficient mass transfer through flow channel geometry optimization, innovative turbulence mechanism, and improved drainage system.
[0007] To achieve the above objectives, a cathode flow field plate for a proton exchange membrane fuel cell for new energy vehicles is provided. The fuel cell includes an anode portion and a cathode portion. The anode portion includes an anode flow field plate, an anode catalyst layer, and an anode gas diffusion layer. The cathode portion includes a cathode flow field plate, a cathode gas diffusion layer, and a cathode catalyst layer. A proton exchange membrane is disposed between the cathode catalyst layer and the anode catalyst layer. An anode flow field plate is provided with an anode flow channel, and a cathode flow field plate is provided with a cathode flow channel.
[0008] The cathode flow channel is serpentine in shape and consists of serpentine channels and serpentine ribs. Multiple serpentine ribs are spaced apart between the serpentine channels. The inlet and outlet of the serpentine channels are located on opposite sides of the cathode flow field plate.
[0009] Baffles are arranged at intervals within the serpentine flow channel. The baffles stand vertically within the serpentine flow channel and reduce the width of the channel in certain areas. A sealing groove is provided around the outermost edge of the serpentine flow channel, and a sealing ring is installed inside the sealing groove.
[0010] The serpentine ribs are provided with drainage grooves extending along the shape of the serpentine ribs. Each serpentine rib is provided with a branch drainage hole. The cathode flow field plate is also provided with a main drainage channel connected to the branch drainage holes. The main drainage channel extends to the outside of the cathode flow field plate.
[0011] The serpentine flow channel design allows for uniform flow of the reactant gas, promoting lateral and vertical gas movement, facilitating forced convection, and encouraging the reactant gas to enter the gas diffusion layer and catalytic layer, thereby improving reaction efficiency. Baffles are installed within the serpentine flow channel, causing the reactant gas to flow in an S-shaped pattern, enhancing lateral turbulence in the flow field, promoting forced convection, and improving mass transfer efficiency.
[0012] Preferably, the serpentine flow channel is divided into an outer flow channel and an inner flow channel, with the outer flow channel sandwiching the inner flow channel, and the width of the outer flow channel being greater than the width of the inner flow channel. Its advantage is reduced pressure in the outer flow channel, thus minimizing lateral leakage of the reactant gas.
[0013] Preferably, the outer flow channel is divided into a left outer flow channel and a right outer flow channel. The width of the first U-shaped bend section of the left outer flow channel near the inlet is smaller than the width of the remaining sections of the left outer flow channel. The width of the last U-shaped bend of the right outer flow channel near the outlet is smaller than the width of the remaining sections of the right outer flow channel.
[0014] Preferably, the inner flow channel is divided into a straight section a and a chamfered section c, with the width of chamfered section c being greater than the width of straight section a; the outer flow channels are each divided into a straight section b and a chamfered section d, with the width of chamfered section d being greater than the width of straight section b. The wider chamfered section is designed to reduce pressure at the bends in the flow channel, alter the direction of the force acting on the gas flow, and prevent lateral gas leakage.
[0015] Preferably, the inlet and outlet of the serpentine flow channel are rectangular in shape, with a cross-sectional area larger than that of the serpentine flow channel itself. This has the advantage of providing larger inlet and outlet channels that gradually widen in one direction, significantly reducing reactant leakage at the inlet and outlet.
[0016] Preferably, the cross-sections of the left and right outer flow channels are pentagonal, and the outer cross-sections facing away from the inner flow channel have an inward oblique angle of 45°. This inward 45° oblique angle provides inward assistance to the movement of the reactant gas, reducing lateral diffusion and leakage of the reactant gas to the outside.
[0017] Preferably, baffles are arranged at certain intervals within each serpentine flow channel. These baffles are classified as L-shaped, 7-shaped, and arc-shaped. The L-shaped and 7-shaped baffles are respectively positioned on the vertical sides of the serpentine flow channel and are staggered and intersecting along the liquid flow direction. The arc-shaped baffles are positioned at the U-shaped bends of the serpentine flow channel. Alternating upper and lower notches between adjacent baffles enhance the vertical disturbance of the gas in the flow field, promote gas entry into the gas diffusion layer, facilitate forced convection, and improve mass transfer efficiency. The baffles also act as obstructors, effectively removing water from the gas within the flow field while simultaneously increasing mass transfer capacity by increasing vertical velocity. This prevents flooding of the gas diffusion layer, improves the uniform distribution and mass transfer capacity of the reactant gas within the flow field, and thus enhances the performance of the fuel cell.
[0018] Preferably, the cross-sectional dimensions of both the outer and inner flow channels are larger than the cross-sectional dimensions of the serpentine ribs to ensure lower contact resistance.
[0019] Compared with the prior art, this utility model has the following advantages:
[0020] 1. The L-shaped, 7-shaped and arc-shaped plates set in the serpentine flow channel form a composite turbulence system: The L-shaped and 7-shaped plates are staggered and intersected on both sides of the flow channel, which forces the gas to generate a vertical velocity component in the flow, breaking the limitation of the traditional serpentine flow channel that only flows in a straight line in one direction, so that the reactant gas can penetrate into the gas diffusion layer and the catalyst layer more evenly, and the mass transfer efficiency is improved.
[0021] 2. The arc-shaped plate is set at the U-shaped bend, which guides the airflow to change direction through curvature, reduces eddy current loss at the bend, and forms local turbulence in the bend area, further enhancing the contact area between the gas and the plate surface, and significantly improving the electrochemical reaction rate.
[0022] 3. The width of the side channel is greater than that of the inner channel. Combined with the variable width design (local narrowing) of the first bend at the inlet of the left outer channel and the last bend at the outlet of the right outer channel, a gradient pressure field is formed. The narrowing design at the inlet can increase the initial airflow velocity and quickly push away the gas trapped in the channel. The narrowing design at the outlet avoids the formation of a stagnation zone due to the low flow velocity at the end of the channel, ensuring the improvement of the uniformity of gas flow velocity throughout the channel.
[0023] 4. The width of the chamfered sections of the inner and outer flow channels is greater than that of the straight sections. By increasing the cross-sectional area of the bends, the pressure drop at the corners is reduced, avoiding lateral gas leakage caused by sudden pressure changes. At the same time, it reduces the risk of bubbles accumulating in the bends and ensures unobstructed mass transfer paths.
[0024] 5. The drainage grooves on the serpentine ribs extend along the shape of the ribs and work in conjunction with the curved path of the serpentine flow channel to form a three-dimensional drainage path of "collection along the flow and centralized discharge": liquid water can flow into the main drainage channel through the branch drainage holes on the ribs at any time during the flow process, avoiding the water accumulation problem caused by the long distance of the traditional single drainage hole, and reducing the occurrence of flooding.
[0025] 6. The main drainage channel is designed as a dual-path (extending to the left and right sides), combined with the branch drainage holes in the U-shaped bend (corresponding to high water accumulation risk areas), to achieve rapid drainage in zones. Especially under high load conditions, it can promptly discharge a large amount of reaction water and maintain the stability of the gas-liquid two-phase flow in the channel.
[0026] 7. The synergistic effect of improved mass transfer efficiency and enhanced drainage capacity significantly reduces the risk of flooding in high current density areas (such as the end of the flow channel) of fuel cells, slows down the rate of battery performance degradation, and extends lifespan. At the same time, the uniform airflow distribution improves the overall voltage consistency of the battery pack and enhances system energy efficiency. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of the exploded three-dimensional structure of a proton exchange membrane fuel cell.
[0028] Figure 2 This is a schematic diagram of the axial structure of the cathode flow field plate;
[0029] Figure 3 This is a schematic diagram of the three-dimensional structure of the cathode flow field plate;
[0030] Figure 4 This is a schematic diagram showing the planar distribution of the left and right outer flow channels on the cathode flow field plate.
[0031] Figure 5 This is a schematic diagram showing the planar distribution of the U-shaped bends E and F in the serpentine flow channel.
[0032] Figure 6 This is a schematic diagram of the planar indicator structure of the right-angled and chamfered sections of the outer and inner flow channels;
[0033] Figure 7 for Figure 4 Schematic diagram of the cross-sectional structure at point BB;
[0034] Figure 8A schematic diagram showing the planar distribution of branch drainage holes and main drainage channels on the cathode flow field plate;
[0035] Figure 9 for Figure 8 A schematic diagram of the cross-sectional structure at point AA.
[0036] The markings in the diagram are as follows: 1. Anode flow field plate; 2. Anode catalyst layer; 3. Anode gas diffusion layer; 4. Proton exchange membrane; 5. Cathode catalyst layer; 6. Cathode gas diffusion layer; 7. Cathode flow field plate; 71-1. Serpentine flow channel; 71-2. Serpentine rib; 71-3. Inlet; 71-4. Outlet; 71-5. Drainage channel; 71-1A. Left outer flow channel; 71-1B. Right outer flow channel; 71-4C. Branch drainage hole; 71-4D. Main drainage channel; 71-6. L-shaped plate; 71-7. 7-shaped plate; 71-8. Arc plate. Detailed Implementation
[0037] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.
[0038] like Figure 1 — Figure 9 A cathode flow field plate for a proton exchange membrane fuel cell for a new energy vehicle is disclosed. The fuel cell includes an anode portion and a cathode portion. The anode portion includes an anode flow field plate 1, an anode catalyst layer 2, and an anode gas diffusion layer 3. The cathode portion includes a cathode flow field plate 7, a cathode gas diffusion layer 6, and a cathode catalyst layer 5. A proton exchange membrane 4 is disposed between the cathode catalyst layer and the anode catalyst layer. An anode flow field plate is provided with an anode flow channel, and a cathode flow field plate is provided with a cathode flow channel.
[0039] The cathode flow channel 71 is serpentine in shape and is divided into serpentine flow channels 71-1 and serpentine ribs 71-2. Multiple serpentine ribs 71-2 are spaced between multiple serpentine flow channels 71-1. The inlet 71-3 and outlet 71-4 of the serpentine flow channels are respectively designed on two opposite sides of the cathode flow field plate, i.e., from... Figure 4 As can be seen, the inlet 71-3 is located in the north, and the outlet 71-4 is located in the south. The inlet and outlet of the serpentine flow channel 71-1 are rectangular in shape, and their cross-sectional area is larger than that of the serpentine flow channel. In this embodiment, four serpentine flow channels 71-1 are designed, with three serpentine ribs 71-2 spaced apart in the middle. Drainage grooves 71-5 extending along the shape of the serpentine ribs 71-2 are provided on the serpentine ribs 71-2.
[0040] In this embodiment, the serpentine flow channel 71-1 is divided into an outer flow channel and an inner flow channel, with the outer flow channel sandwiching the inner flow channel, and the width of the outer flow channel being greater than the width of the inner flow channel.
[0041] Furthermore, the outer flow channel is divided into a left outer flow channel 71-1A and a right outer flow channel 71-1B (e.g. Figure 4 As shown, the two different shaded areas represent the left and right outer flow channels, and the two inner flow channels are sandwiched between the left and right outer flow channels, as shown. Figure 4 As shown, when the serpentine flow extends from the north-facing entrance to the south-facing direction, the first and last bends are both 90° vertical bends, while the two in the middle are U-shaped bends. Therefore, the width of the first U-shaped bend segment E near the entrance in the left outer flow channel is less than the width of the remaining segments of the left outer flow channel, and the width of the last U-shaped bend F near the exit in the right outer flow channel is less than the width of the remaining segments of the right outer flow channel (e.g., Figure 5 As shown, the shaded areas are curves E and F.
[0042] like Figure 6 As shown, the inner flow channel is divided into a straight section a and a chamfered section c, with the width of the chamfered section c being greater than the width of the straight section a; the outer flow channels are all divided into a straight section b and a chamfered section d, with the width of the chamfered section d being greater than the width of the straight section b.
[0043] like Figure 7 As shown, the cross-sections of the left outer flow channel 71-1A and the right outer flow channel 71-1B are pentagonal, and the outer cross-sections facing away from the inner flow channel have an inward oblique angle of 45°. Furthermore, the cross-sectional dimensions (b, a) of both the outer and inner flow channels are larger than the cross-sectional dimension h of the serpentine rib (e.g., ...). Figure 6 (The positions of a, b, and h are shown).
[0044] like Figure 8 , Figure 9 As shown, each serpentine rib 71-2 has two branch drainage holes 71-4C. The serpentine rib 71-2 has two U-shaped bends and two right-angle bends. The two branch drainage holes 71-4C are located on the two U-shaped bends respectively. The branch drainage holes 71-4C of the three serpentine ribs 71-2 are arranged in a horizontal row. The branch drainage holes 71-4C are in the drainage groove 71-5. The cathode flow field plate also has a main drainage channel 71-4D that connects to the branch drainage holes 71-4C. The main drainage channel 71-4D extends outside the cathode flow field plate. The two rows of branch drainage holes correspond to the two main drainage channels. One extends out from the left side of the cathode flow field plate, and the other extends out from the right side of the cathode flow field plate (the orientation is described according to the top, bottom, left and right of the diagram).
[0045] like Figure 2 , Figure 6 As shown, baffles are arranged at intervals in the serpentine flow channel 71-1. The baffles stand vertically in the serpentine flow channel and reduce the width of the serpentine flow channel in some local positions. A sealing groove 72 is provided outside the outermost serpentine flow channel. A sealing ring is installed in the sealing groove 72 to prevent the leakage of reaction gas.
[0046] Baffles are installed at certain intervals in each serpentine flow channel. The baffles are divided into L-shaped plates 71-6, 7-shaped plates 71-7, and arc-shaped plates 71-8. The L-shaped plates and 7-shaped plates are respectively installed on the vertical sides of the two sides of the serpentine flow channel. The L-shaped plates 71-6 and 7-shaped plates 71-7 are distributed on two opposite vertical sides, not on the same side, and are staggered and intersecting along the direction of liquid flow. The arc-shaped plates are installed at the U-shaped bend of the serpentine flow channel.
[0047] The proton exchange membrane fuel cell has pre-set bolt holes around its perimeter and is fastened using bolt connections.
[0048] The foregoing has provided a detailed description of a cathode flow field plate for a proton exchange membrane fuel cell for new energy vehicles. The specific embodiments described are merely for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.
Claims
1. A cathode flow field plate for a proton exchange membrane fuel cell for a new energy vehicle, the fuel cell comprising an anode portion and a cathode portion, the anode portion comprising an anode flow field plate, an anode catalyst layer, and an anode gas diffusion layer; the cathode portion comprising a cathode flow field plate, a cathode gas diffusion layer, and a cathode catalyst layer, a proton exchange membrane being disposed between the cathode catalyst layer and the anode catalyst layer, an anode flow field plate having an anode flow channel, and a cathode flow field plate having a cathode flow channel; characterized in that The cathode flow channel is serpentine in shape and consists of serpentine channels and serpentine ribs. Multiple serpentine ribs are spaced apart between the serpentine channels. The inlet and outlet of the serpentine channels are located on opposite sides of the cathode flow field plate. Baffles are arranged at intervals within the serpentine flow channel. The baffles stand vertically within the serpentine flow channel and reduce the width of the channel in certain areas. A sealing groove is provided around the outermost edge of the serpentine flow channel, and a sealing ring is installed inside the sealing groove. The serpentine ribs are provided with drainage grooves extending along the shape of the serpentine ribs. Each serpentine rib is provided with a branch drainage hole. The cathode flow field plate is also provided with a main drainage channel connected to the branch drainage holes. The main drainage channel extends to the outside of the cathode flow field plate.
2. The cathode flow field plate for a proton exchange membrane fuel cell for new energy vehicles according to claim 1, characterized in that, The serpentine flow channel is divided into an outer flow channel and an inner flow channel, with the outer flow channel sandwiching the inner flow channel, and the width of the outer flow channel being greater than the width of the inner flow channel.
3. The cathode flow field plate for a proton exchange membrane fuel cell for new energy vehicles according to claim 2, characterized in that, The outer flow channel is divided into a left outer flow channel and a right outer flow channel. The width of the first U-shaped bend section of the left outer flow channel near the inlet is smaller than the width of the remaining sections of the left outer flow channel. The width of the last U-shaped bend of the right outer flow channel near the outlet is smaller than the width of the remaining sections of the right outer flow channel.
4. The cathode flow field plate for a proton exchange membrane fuel cell for new energy vehicles according to claim 2, characterized in that, The inner flow channel is divided into a straight section a and a chamfered section c, with the width of the chamfered section c being greater than the width of the straight section a. The outer flow channel is divided into a straight section b and a chamfered section d, with the width of the chamfered section d being greater than the width of the straight section b.
5. The cathode flow field plate for a proton exchange membrane fuel cell for new energy vehicles according to claim 1, characterized in that, The inlet and outlet of the serpentine flow channel are rectangular in shape, and their cross-sectional area is larger than that of the serpentine flow channel.
6. The cathode flow field plate for a proton exchange membrane fuel cell for new energy vehicles according to claim 3, characterized in that, The cross-sections of the left and right outer flow channels are pentagonal, and the outer cross-sections facing away from the inner flow channel have an inward oblique angle of 45°.
7. The cathode flow field plate for a proton exchange membrane fuel cell for new energy vehicles according to claim 1, characterized in that, Baffles are installed at certain intervals in each serpentine flow channel. The baffles are divided into L-shaped plates, 7-shaped plates and arc-shaped plates. The L-shaped plates and 7-shaped plates are respectively installed on the vertical sides of the two sides of the serpentine flow channel and are staggered and intersecting along the direction of liquid flow. The arc-shaped plates are installed at the U-shaped bend of the serpentine flow channel.
8. The cathode flow field plate for a proton exchange membrane fuel cell for new energy vehicles according to claim 2, characterized in that, The cross-sectional dimensions of both the outer and inner flow channels are larger than those of the serpentine ribs.