Fuel cell bipolar plate with Janus bifunctional microstructure
By designing a Janus dual-function microstructure on the bipolar plate of the fuel cell, the problems of condensate accumulation and gas blockage were solved, achieving stable humidification and rapid drainage, thereby improving the performance and reliability of the fuel cell.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XIAMEN UNIV
- Filing Date
- 2025-05-13
- Publication Date
- 2026-05-01
AI Technical Summary
Existing fuel cell bipolar plates are prone to problems such as condensate accumulation, gas blockage, and hydrothermal management imbalance under complex operating conditions. In particular, membrane drying is likely to occur at the gas inlet section, and water blockage is likely to occur at the outlet section, affecting battery performance and reliability.
A bipolar plate for a fuel cell with a Janus dual-function microstructure is designed. The gas inlet section uses a hydrophilic microchannel to retain moisture through the capillary action of the transverse and longitudinal grooves. The outlet section uses a hydrophobic microchannel to drive the unidirectional movement of droplets through the curvature gradient formed by adjacent ratchet micro-units, which promotes droplet sliding and drainage.
It achieves a stable humid environment at the inlet section to avoid membrane dryness failure, and quickly removes liquid water blockage at the outlet section, improving gas transmission efficiency and water management capabilities, and ensuring the normal operation of the bipolar plate.
Smart Images
Figure CN224190943U_ABST
Abstract
Description
A fuel cell bipolar plate with a Janus dual-functional microstructure Technical Field
[0001] This utility model belongs to the field of fuel cell technology, specifically a fuel cell bipolar plate with a Janus dual-function microstructure. Background Technology
[0002] In fuel cell systems, bipolar plates are key components, serving not only as the main supporting structure but also undertaking multiple functions such as gas transport, current conduction, heat conduction, and water management, significantly impacting fuel cell performance, lifespan, and reliability. Existing fuel cell bipolar plates mostly employ uniform materials and flow channel structures for reactant gas transport. However, under complex operating conditions, problems such as condensate accumulation, gas blockage, and imbalances in water and heat management can easily arise. Particularly in the gas flow channel, moisture behavior exhibits spatial variability: the gas inlet section is often a high-humidity gas mixture, and the high-velocity gas easily carries away localized moisture, easily causing localized "membrane dryness" at the inlet section; therefore, the proton exchange membrane must be kept sufficiently moist at the inlet section. Conversely, the gas outlet section is a high-concentration area for condensation, easily causing localized "water blockage," necessitating improved drainage capacity. Summary of the Invention
[0003] The purpose of this invention is to provide a fuel cell bipolar plate with a Janus dual-function microstructure. This bipolar plate, in the hydrophilic microchannel of the gas inlet section, can maintain moisture through the capillary action of transverse and longitudinal grooves, providing a stable humid environment for the membrane and preventing membrane dryness failure. In the hydrophobic microchannel of the gas outlet section, adjacent ratchet microunits can form a curvature gradient along the airflow direction, inducing a Laplace pressure difference to drive unidirectional droplet movement. This reduces water droplet adhesion, promotes timely sliding of condensed droplets, improves gas transmission efficiency, eliminates liquid water blockage, and achieves rapid drainage.
[0004] To achieve the above objectives, the present invention adopts the following technical solution:
[0005] A fuel cell bipolar plate with a Janus dual-functional microstructure includes a substrate, on which an anode flow field and a cathode flow field are respectively disposed on the front and back sides. Both the anode and cathode flow fields have Janus dual-functional microstructures on their surfaces, each comprising a hydrophilic microchannel and a hydrophobic microchannel. An air inlet is provided on the substrate at the air inlet end of the hydrophilic microchannel, and the air outlet end of the hydrophilic microchannel is connected to the air inlet end of the hydrophobic microchannel. An air outlet is provided on the substrate at the air outlet end of the hydrophobic microchannel. Transverse grooves are provided on the substrate along the side of the hydrophilic microchannel, and multiple longitudinal grooves are spaced apart on the substrate along the side of the hydrophilic microchannel. The lower end of the longitudinal grooves is connected to the hydrophilic microchannel, and the upper end of the longitudinal grooves is connected to the transverse grooves, achieving moisture retention through capillary action of the transverse and longitudinal grooves. Multiple sequentially connected ratchet microunits are disposed on the side of the hydrophobic microchannel, with adjacent ratchet microunits forming a curvature gradient along the airflow direction to reduce water droplet adhesion.
[0006] Furthermore, the tip curvature radius of the ratchet micro-unit is 0.2 mm, and the arc length is 0.46 mm; the back curvature radius of the ratchet micro-unit is 5.75 mm, and the arc length is 2.16 mm.
[0007] Furthermore, the width of both the transverse and longitudinal grooves is 0.1 mm.
[0008] Furthermore, the distance between two adjacent longitudinal grooves is 0.9 mm.
[0009] Furthermore, the surfaces of the hydrophilic microchannels, transverse grooves, and longitudinal grooves are respectively coated with a hydrophilic coating.
[0010] Furthermore, the hydrophilic coating is made of aluminum oxide or titanium oxide.
[0011] Furthermore, the surfaces of the hydrophobic microchannels and ratchet microunits are respectively coated with a hydrophobic coating.
[0012] Furthermore, the hydrophobic coating is made of polytetrafluoroethylene or perfluoroalkoxy resin.
[0013] Furthermore, the flow channel shape of the hydrophilic microchannel and the hydrophobic microchannel is a serpentine flow channel, a parallel flow channel, or a finger-shaped flow channel.
[0014] After adopting the above technical solution, the present invention has the following beneficial effects:
[0015] 1. This utility model discloses a bipolar plate for a fuel cell with a Janus dual-function microstructure. In the hydrophilic microchannel of the gas inlet section, moisture retention can be achieved through the capillary action of transverse and longitudinal grooves, providing a stable humid environment for the membrane and preventing membrane dry failure. In the hydrophobic microchannel of the gas outlet section, a curvature gradient can be formed along the airflow direction by adjacent ratchet microunits, inducing a Laplace pressure difference to drive the unidirectional movement of droplets. This reduces the adhesion of water droplets, promotes the timely sliding of condensed droplets, improves gas transmission efficiency, eliminates liquid water blockage, and achieves rapid drainage.
[0016] 2. This utility model discloses a fuel cell bipolar plate with a Janus dual-function microstructure. The width of both the transverse and longitudinal grooves is 0.1 mm, and the spacing between adjacent longitudinal grooves is 0.9 mm. Utilizing the capillary action of the transverse and longitudinal grooves, droplets are drawn in and kept on the surface, preventing them from being discharged too quickly due to airflow disturbances, thus facilitating continuous humidification. These microstructures increase the adhesion area of liquid water, enhance capillary action, and maintain water retention or prolong the residence time of water vapor. Furthermore, the surfaces of the hydrophilic microchannels, transverse grooves, and longitudinal grooves are coated with hydrophilic coatings made of materials such as alumina or titanium dioxide, which improves the surface hydrophilicity.
[0017] 3. This utility model discloses a fuel cell bipolar plate with a Janus dual-function microstructure. The ratchet microunit has a tooth tip curvature radius of 0.2 mm and an arc length of 0.46 mm; the tooth back curvature radius of the ratchet microunit is 5.75 mm and the arc length is 2.16 mm. This ratchet microunit structural design can isomorphically form a curvature gradient, inducing a Laplace pressure difference to drive the unidirectional movement of droplets, which helps reduce the adhesion of water droplets, allowing them to be quickly discharged and ensuring that the outlet channel remains clean, preventing water accumulation. Furthermore, the hydrophobic microchannels and ratchet microunits are coated with hydrophobic coatings made of materials such as polytetrafluoroethylene or perfluoroalkoxy resin, which gives the surfaces strong hydrophobicity, forming a low surface energy layer. This coating can effectively reduce water adhesion on the surface and promote rapid water droplet discharge. Attached Figure Description
[0018] Figure 1 is a top view of the structure of this utility model;
[0019] Figure 2 is a three-dimensional structural diagram of this utility model;
[0020] Figure 3 is a magnified view of part A in Figure 2;
[0021] Figure 4 is a magnified view of part B in Figure 2.
[0022] The reference numerals in the figure are as follows:
[0023] 1. Substrate; 11. Air inlet; 12. Air outlet; 2. Hydrophilic microchannel; 21. Lateral groove; 22. Longitudinal groove; 3. Hydrophobic microchannel; 31. Ratchet microunit. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0025] Please refer to Figures 1 to 4. A fuel cell bipolar plate with a Janus dual-functional microstructure includes a substrate 1. An anode flow field and a cathode flow field are respectively arranged on the front and back sides of the substrate 1. Janus dual-functional microstructures are provided on the surfaces of both the anode and cathode flow fields. The Janus dual-functional microstructures include hydrophilic microchannels 2 and hydrophobic microchannels 3. An air inlet 11 is provided on the substrate 1 at the air inlet end of the hydrophilic microchannel 2, and the air outlet end of the hydrophilic microchannel 2 is connected to the air inlet end of the hydrophobic microchannel 3. The substrate 1 at the air outlet end of the hydrophobic microchannel 3 has an air inlet 11. The plate 1 is provided with an air outlet 12; the substrate 1 on the side of the hydrophilic microchannel 2 is provided with a transverse groove 21, and the substrate 1 on the side of the hydrophilic microchannel 2 is provided with a plurality of longitudinal grooves 22 at intervals; the lower end of the longitudinal groove 22 is connected to the hydrophilic microchannel 2, and the upper end of the longitudinal groove 22 is connected to the transverse groove 21, and moisture is maintained through the capillary action of the transverse groove 21 and the longitudinal groove 22; the side of the hydrophobic microchannel 3 is provided with a plurality of ratchet micro-units 31 connected in sequence, and the adjacent ratchet micro-units 31 form a curvature gradient along the airflow direction to reduce the adhesion of water droplets.
[0026] As shown in Figures 1, 2 and 4, the tooth tip curvature radius of the ratchet micro-unit 31 is 0.2 mm and the arc length is 0.46 mm; the tooth back curvature radius of the ratchet micro-unit 31 is 5.75 mm and the arc length is 2.16 mm. The tooth back of the ratchet micro-unit 31 is closer to the water inlet end, and the tooth tip of the ratchet micro-unit 31 is closer to the water outlet end.
[0027] As shown in Figures 1, 2 and 3, the width of both the transverse groove 21 and the longitudinal groove 22 is 0.1 mm.
[0028] As shown in Figures 1, 2 and 3, the distance between two adjacent longitudinal grooves 22 is 0.9 mm.
[0029] As shown in Figures 1, 2 and 3, the surfaces of the hydrophilic microchannel 2, the transverse groove 21 and the longitudinal groove 22 are respectively coated with a hydrophilic coating.
[0030] As shown in Figures 1, 2 and 3, the hydrophilic coating is made of aluminum oxide or titanium oxide.
[0031] As shown in Figures 1, 2 and 4, the surfaces of the hydrophobic microchannel 3 and the ratchet microunit 31 are respectively coated with a hydrophobic coating.
[0032] As shown in Figures 1, 2 and 4, the hydrophobic coating is made of polytetrafluoroethylene or perfluoroalkoxy resin.
[0033] As shown in Figures 1 to 4, the flow channel shapes of the hydrophilic microchannel 2 and the hydrophobic microchannel 3 are serpentine, parallel, or finger-shaped.
[0034] It is understood that in this disclosure, "multiple" refers to two or more, and other quantifiers are similar. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. The singular forms "a," "the," and "the" are also intended to include the plural forms unless the context clearly indicates otherwise.
[0035] It is further understood that the terms "first," "second," etc., are used to describe various types of information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another, and do not indicate a specific order or degree of importance. In fact, the expressions "first," "second," etc., are completely interchangeable. For example, without departing from the scope of this disclosure, first information can also be referred to as second information, and similarly, second information can also be referred to as first information.
[0036] It is further understood that the terms “center,” “longitudinal,” “lateral,” “front,” “rear,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation.
[0037] It can be further understood that, unless otherwise specified, "connection" includes both direct connections where no other components exist between the two parties and indirect connections where other components exist between them.
[0038] It is further understood that although operations are described in a specific order in the accompanying drawings in the embodiments of this disclosure, this should not be construed as requiring these operations to be performed in the specific order or serial order shown, or requiring all of the shown operations to be performed to obtain the desired result. In certain environments, multitasking and parallel processing may be advantageous.
[0039] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.
[0040] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.
Claims
1. A fuel cell bipolar plate with a Janus dual-function microstructure, comprising a substrate, wherein an anode flow field and a cathode flow field are respectively disposed on the front and back sides of the substrate; characterized in that: Both the anode and cathode flow fields are provided with Janus dual-function microstructures, which include hydrophilic microchannels and hydrophobic microchannels. An air inlet is provided on the substrate at the air inlet end of the hydrophilic microchannel, and the air outlet end of the hydrophilic microchannel is connected to the air inlet end of the hydrophobic microchannel. An air outlet is provided on the substrate at the air outlet end of the hydrophobic microchannel. Transverse grooves are provided on the substrate on the side of the hydrophilic microchannel, and multiple longitudinal grooves are provided at intervals on the substrate on the side of the hydrophilic microchannel. The lower end of the longitudinal groove is connected to the hydrophilic microchannel, and the upper end of the longitudinal groove is connected to the transverse groove, achieving moisture retention through capillary action of the transverse and longitudinal grooves. Multiple sequentially connected ratchet microunits are provided on the side of the hydrophobic microchannel, and adjacent ratchet microunits form a curvature gradient along the airflow direction to reduce water droplet adhesion.
2. The fuel cell bipolar plate with a Janus dual-functional microstructure as described in claim 1, characterized in that: The ratchet micro-unit has a tooth tip curvature radius of 0.2 mm and an arc length of 0.46 mm; the ratchet micro-unit has a tooth back curvature radius of 5.75 mm and an arc length of 2.16 mm.
3. A fuel cell bipolar plate with a Janus dual-functional microstructure as described in claim 1, characterized in that: The width of both the transverse and longitudinal grooves is 0.1 mm.
4. A fuel cell bipolar plate with a Janus dual-functional microstructure as described in claim 1, characterized in that: The distance between two adjacent longitudinal grooves is 0.9 mm.
5. A fuel cell bipolar plate with a Janus dual-functional microstructure as described in claim 1, characterized in that: The surfaces of the hydrophilic microchannels, transverse grooves, and longitudinal grooves are each coated with a hydrophilic coating.
6. A fuel cell bipolar plate with a Janus dual-functional microstructure as described in claim 5, characterized in that: The hydrophilic coating is made of aluminum oxide or titanium oxide.
7. A fuel cell bipolar plate with a Janus dual-functional microstructure as described in claim 1, characterized in that: The hydrophobic microchannels and ratchet microunits are respectively coated with hydrophobic coatings.
8. A fuel cell bipolar plate with a Janus dual-functional microstructure as described in claim 7, characterized in that: The hydrophobic coating is made of polytetrafluoroethylene or perfluoroalkoxy resin.
9. A fuel cell bipolar plate with a Janus dual-functional microstructure as described in claim 1, characterized in that: The hydrophilic and hydrophobic microchannels are serpentine, parallel, or finger-shaped flow channels.