Gas diffusion layer of fuel cell, fuel cell and fuel cell stack
By setting gas flow channel ridges and grooves in the gas diffusion layer of the fuel cell, the flooding problem of the fuel cell is solved, the catalytic efficiency of the catalyst layer is improved, and thus the working efficiency of the fuel cell is enhanced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2026-03-13
AI Technical Summary
In proton exchange membrane fuel cells, water cannot be discharged smoothly under high current density, leading to water flooding inside the cell, which affects the electrochemical reaction and consequently reduces cell performance.
Gas flow channel ridges and gas flow channel grooves are set in the gas diffusion layer to form gas flow channel grooves, which promotes the flow of gas and water in the vertical and horizontal planes and improves the catalytic efficiency of the catalyst layer.
By designing gas flow channels, flooding of the fuel cell is avoided, the catalytic efficiency of the catalyst layer is improved, and thus the working efficiency of the fuel cell is enhanced.
Smart Images
Figure CN121662852A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of fuel cell technology, and in particular to a gas diffusion layer for a fuel cell, a fuel cell, and a fuel cell stack. Background Technology
[0002] A proton exchange membrane fuel cell is an electrochemical energy conversion device. Its working principle is as follows: hydrogen gas introduced into the anode undergoes an oxidation reaction, and oxygen gas introduced into the cathode undergoes a reduction reaction, producing a large amount of liquid water. However, for proton exchange membrane fuel cells, the water produced by the electrochemical reaction under high current density cannot be discharged smoothly, which leads to the accumulation and aggregation of water inside the cell. In severe cases, it can cause the cell to be flooded, and the reacting gases cannot reach the catalyst surface to carry out the electrochemical reaction smoothly, resulting in a sharp decline in cell performance. Summary of the Invention
[0003] To address the aforementioned problems in the prior art, the purpose of this application is to improve the catalytic efficiency of the catalyst layer and thus improve the working efficiency of the fuel cell by setting gas flow channel ridges and gas flow channel grooves in the gas diffusion layer.
[0004] To address the aforementioned issues, this application provides a gas diffusion layer for a fuel cell, comprising a substrate layer and a microporous layer, wherein the substrate layer and the microporous layer are stacked together. The substrate layer includes a gas flow channel ridge, which is disposed on the side away from the microporous layer, and the gas flow channel ridge and the edge of the substrate layer form a gas flow channel groove.
[0005] In this embodiment of the application, the gas channel grooves on both sides of the airflow channel ridge have different groove widths.
[0006] In this embodiment of the application, the gas flow channel includes at least one of a direct flow channel, a meandering flow channel, and a serpentine flow channel.
[0007] On the other hand, this application also provides a fuel cell, including an anode gas diffusion layer, a cathode gas diffusion layer, a cooling plate, a cathode separator, an anode catalyst layer, a cathode catalyst layer, and a proton exchange membrane. The structure of the anode gas diffusion layer and the structure of the cathode gas diffusion layer are the same as the gas diffusion layer structures described in the embodiments of this application. The cooling plate, the cathode separator, the cathode gas diffusion layer, the cathode catalyst layer, the proton exchange membrane, the anode catalyst layer, and the anode gas diffusion layer are stacked in sequence.
[0008] In this embodiment, the fuel cell further includes an anode separator, and the anode catalyst layer, the anode gas diffusion layer, and the anode separator are stacked in sequence.
[0009] In this embodiment, the cooling electrode plate is provided with cooling channels, which are parallel, perpendicular or intersecting with the anode gas diffusion layer.
[0010] In this embodiment, the cooling channel includes an upper channel and a lower channel. The coolant in the lower channel is in direct contact with the cathode separator, and the coolant in the upper channel is in indirect contact with the cathode separator through the cooling electrode plate.
[0011] In this embodiment, the cathode separator and the anode separator are metal separators or graphite separators.
[0012] In another embodiment of this application, the cooling electrode plate is provided with cooling channels, which are parallel, perpendicular or intersecting with the anode gas diffusion layer; The cooling channel has only one lower channel that is in direct contact with the cathode partition, and the non-channel side of the cooling electrode is a closed structure.
[0013] On the other hand, this application also provides a fuel cell stack, which includes a plurality of fuel cells as described in this application.
[0014] Due to the above technical solution, the gas diffusion layer of the fuel cell described in this application has the following beneficial effects: By setting a gas flow channel ridge on the side of the gas diffusion layer away from the microporous layer, a gas flow channel groove is formed between the gas flow channel ridge and the edge of the gas diffusion layer. During the operation of the fuel cell, the water flow in the gas diffusion layer will flow in the vertical and horizontal planes of the gas diffusion layer. As a result, some oxygen can be stored in the gas flow channel groove, which will not cause the fuel cell to be flooded. This improves the catalytic efficiency of the catalyst layer and thus improves the working efficiency of the fuel cell. Attached Figure Description
[0015] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.
[0016] Figure 1 is a schematic diagram of the gas diffusion layer of the fuel cell in an embodiment of this application; Figure 2 is a partial structural schematic diagram of the gas diffusion layer of the fuel cell in an embodiment of this application; Figure 3 is a schematic diagram of the structure of the fuel cell stack in an embodiment of this application; Figure 4 is a schematic diagram of the structure of a fuel cell stack in another embodiment of this application.
[0017] Among them, 1-gas diffusion layer, 11-base layer, 111-gas flow channel ridge, 112-gas flow channel groove, 12-microporous layer, 2-anode gas diffusion layer, 3-cathode gas diffusion layer, 4-cooling electrode plate, 41-cooling flow channel, 5-cathode partition, 6-anode catalyst layer, 7-cathode catalyst layer, 8-proton exchange membrane, 9-anode partition. Detailed Implementation
[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0019] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this application. In the description of this application, it should be understood that the terms "upper," "lower," "left," "right," "top," "bottom," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.
[0020] Combination Figure 1-2 This application provides a gas diffusion layer for a fuel cell. The gas diffusion layer 1 includes a base layer 11 and a microporous layer 2, which are stacked together. The base layer 11 includes a gas flow channel ridge 111, which is located on the side away from the microporous layer 2. The gas flow channel ridge 111 and the edge of the base layer 11 form a gas flow channel groove 112.
[0021] In a specific embodiment of this application, the substrate layer 11 is made of carbon fiber paper, carbon fiber cloth or resin, and forms a porous structure through anisotropic stacking; the microporous layer 2 is a slurry made of nano-level conductive carbon black (such as Vulcan XC-72) and hydrophobic agent (PTFE), which is attached to the surface of the substrate layer 11 by screen printing, spraying or coating process.
[0022] In a specific embodiment of this application, the gas flow channel 112 is the main channel for gas to enter the fuel cell. The gas flow channel 112 is used for gas guiding and drainage. After the fuel cell reaction gas enters the flow channel, in addition to moving along the gas flow channel 112, it also flows in the vertical and horizontal directions of the gas diffusion layer 1. The reaction gas includes hydrogen and oxygen.
[0023] In a specific embodiment of this application, when the water generated by the fuel cell collects from the catalyst layer to the diffusion layer, since the substrate layer 11 is a porous structure, even if the gaps on the gas flow channel ridge 111 become smaller due to the assembly pressure, gas still flows within the gas flow channel ridge 111 due to the setting of the gas flow channel groove 112, thereby enabling the gas to quickly reach the catalyst layer of the fuel cell and thus increasing the oxygen concentration of the catalyst layer.
[0024] In a specific embodiment of this application, a gas flow channel ridge 111 is provided on the side of the gas diffusion layer 1 away from the microporous layer 2, thereby forming a gas flow channel groove 112 with the edge of the gas diffusion layer 1. During the operation of the fuel cell, the water flow in the gas diffusion layer 1 will flow in the vertical and horizontal planes of the gas diffusion layer 1, thereby storing some oxygen in the gas flow channel groove 112, preventing the fuel cell from being flooded, thereby improving the catalytic efficiency of the catalyst layer, and thus improving the working efficiency of the fuel cell.
[0025] In this embodiment, the gas channel grooves 112 on both sides of the airflow channel ridge have different groove widths.
[0026] In this embodiment, the different widths of the gas channel grooves 112 on both sides of the gas flow channel ridge can create a pressure difference between the two corresponding flow channel grooves, generating convection, further improving the liquid water discharge efficiency of the gas flow channel ridge, thereby increasing the oxygen content of the catalyst layer, improving the catalytic efficiency of the catalyst layer, and thus improving the working efficiency of the fuel cell.
[0027] In this embodiment, the gas flow channel 112 includes at least one of a direct flow channel, a meandering flow channel, and a serpentine flow channel.
[0028] In one specific embodiment of this application, the thickness of the gas diffusion layer of the fuel cell is 0.3-1 mm.
[0029] In one specific embodiment of this application, the depth of the gas flow channel 112 is 0.2-0.7 mm.
[0030] In one specific embodiment of this application, the width of the gas flow channel ridge 111 is 0.2-1 mm.
[0031] In one specific embodiment of this application, the width ratio between the gas channel groove 112 and the gas channel ridge 111 is 0.7-1.3.
[0032] In another specific embodiment of this application, the thickness of the gas diffusion layer of the fuel cell is 0.3-0.7 mm.
[0033] In another specific embodiment of this application, the depth of the gas flow channel 112 is 0.3-0.5 mm.
[0034] In another specific embodiment of this application, the width of the gas flow channel ridge 111 is 0.3-0.7 mm.
[0035] In another specific embodiment of this application, the width ratio between the gas channel groove 112 and the gas channel ridge 111 is 1.0-1.3.
[0036] In a preferred embodiment of this application, the thickness of the gas diffusion layer of the fuel cell is 0.4-0.5 mm.
[0037] In a preferred embodiment of this application, the depth of the gas flow channel 112 is 0.3-0.4 mm.
[0038] In a preferred embodiment of this application, the width of the gas flow channel ridge 111 is 0.4-0.5 mm.
[0039] In a preferred embodiment of this application, the width ratio between the gas channel groove 112 and the gas channel ridge 111 is 1.0-1.1.
[0040] In specific embodiments of this application, the average pore size of the substrate layer 11 is less than 80 nm; preferably, the average pore size of the substrate layer 11 is less than 60 nm; more preferably, the average pore size of the substrate layer 11 is less than 50 nm.
[0041] In a specific embodiment of this application, the normal permeability of the gas diffusion layer 1 is greater than or equal to 10*10-6 m / Pa•S, and the in-plane permeability of the gas diffusion layer 1 is greater than or equal to 50*10-12 m3 / Pa•S. This ensures that the liquid water in the gas flow channel 112 can be discharged while also ensuring the gas concentration below the shoulder, thereby increasing the oxygen content of the catalyst layer and improving the reaction efficiency of the fuel cell.
[0042] The gas diffusion layer of the fuel cell in this embodiment has the following beneficial effects: By providing a gas flow channel ridge 111 on the side of the gas diffusion layer 1 away from the microporous layer 2, a gas flow channel groove 112 is formed between the gas flow channel ridge 111 and the edge of the gas diffusion layer 1. During the operation of the fuel cell, the water flow in the gas diffusion layer 1 will flow in the vertical and horizontal planes of the gas diffusion layer 1. As a result, some oxygen can be stored in the gas flow channel groove 112, which will not cause the fuel cell to be flooded. This improves the catalytic efficiency of the catalyst layer and thus improves the working efficiency of the fuel cell.
[0043] refer to Figure 3 This application also provides a fuel cell, which includes an anode gas diffusion layer 2, a cathode gas diffusion layer 3, a cooling plate 4, a cathode separator 5, an anode catalyst layer 6, a cathode catalyst layer 7, and a proton exchange membrane 8. The structures of the anode gas diffusion layer 2 and the cathode gas diffusion layer 3 are the same as those of the gas diffusion layer 1 in this application embodiment. The cooling plate 4, cathode separator 5, cathode gas diffusion layer 3, cathode catalyst layer 7, proton exchange membrane 8, anode catalyst layer 6, and anode gas diffusion layer 2 are stacked sequentially.
[0044] In a specific embodiment of this application, the proton exchange membrane 8 has a thickness of 50-180 micrometers and is made of materials such as perfluorosulfonic acid polymer, used to conduct protons and block the direct mixing of hydrogen and oxygen.
[0045] In a specific embodiment of this application, the anode catalyst layer 6 and the cathode catalyst layer 7 may be platinum or platinum-carbon catalysts. The anode catalyst layer 6 is used to promote the anode hydrogen oxidation reaction; the cathode catalyst layer 7 is used to promote the cathode oxygen reduction reaction.
[0046] In a specific embodiment of this application, the anode gas diffusion layer 2 or the cathode gas diffusion layer 3 includes a base layer 11 and a microporous layer 2, which are stacked together. The base layer 11 includes a gas flow channel ridge 111, which is disposed on the side away from the microporous layer 2. The gas flow channel ridge 111 and the edge of the base layer 11 form a gas flow channel groove 112.
[0047] In a specific embodiment of this application, the substrate layer 11 is made of carbon fiber paper, carbon fiber cloth or resin, and forms a porous structure through anisotropic stacking; the microporous layer 2 is a slurry made of nano-level conductive carbon black (such as Vulcan XC-72) and hydrophobic agent (PTFE), which is attached to the surface of the substrate layer 11 by screen printing, spraying or coating process.
[0048] In a specific embodiment of this application, the gas flow channel 112 is the main channel for gas to enter the fuel cell. The gas flow channel 112 is used for gas guiding and drainage. After the fuel cell reaction gas enters the flow channel, in addition to moving along the gas flow channel 112, it also flows in the vertical and horizontal directions of the gas diffusion layer 1. The reaction gas includes hydrogen and oxygen.
[0049] In a specific embodiment of this application, when the water generated by the fuel cell collects from the catalyst layer to the diffusion layer, since the substrate layer 11 is a porous structure, even if the gaps on the gas flow channel ridge 111 become smaller due to the assembly pressure, gas still flows within the gas flow channel ridge 111 due to the setting of the gas flow channel groove 112, thereby enabling the gas to quickly reach the catalyst layer of the fuel cell and thus increasing the oxygen concentration of the catalyst layer.
[0050] In a specific embodiment of this application, a gas flow channel ridge 111 is provided on the side of the gas diffusion layer 1 away from the microporous layer 2, thereby forming a gas flow channel groove 112 with the edge of the gas diffusion layer 1. During the operation of the fuel cell, the water flow in the gas diffusion layer 1 will flow in the vertical and horizontal planes of the gas diffusion layer 1, thereby storing some oxygen in the gas flow channel groove 112, preventing the fuel cell from being flooded, thereby improving the catalytic efficiency of the catalyst layer, and thus improving the working efficiency of the fuel cell.
[0051] In this embodiment, the gas channel grooves 112 on both sides of the airflow channel ridge have different groove widths.
[0052] In this embodiment, the different widths of the gas channel grooves 112 on both sides of the gas flow channel ridge can create a pressure difference between the two corresponding flow channel grooves, generating convection, further improving the liquid water discharge efficiency of the gas flow channel ridge, thereby increasing the oxygen content of the catalyst layer, improving the catalytic efficiency of the catalyst layer, and thus improving the working efficiency of the fuel cell.
[0053] In this embodiment, the gas flow channel 112 includes at least one of a direct flow channel, a meandering flow channel, and a serpentine flow channel.
[0054] In one specific embodiment of this application, the thickness of the gas diffusion layer of the fuel cell is 0.3-1 mm.
[0055] In one specific embodiment of this application, the depth of the gas flow channel 112 is 0.2-0.7 mm.
[0056] In one specific embodiment of this application, the width of the gas flow channel ridge 111 is 0.2-1 mm.
[0057] In one specific embodiment of this application, the width ratio between the gas channel groove 112 and the gas channel ridge 111 is 0.7-1.3.
[0058] In another specific embodiment of this application, the thickness of the gas diffusion layer of the fuel cell is 0.3-0.7 mm.
[0059] In another specific embodiment of this application, the depth of the gas flow channel 112 is 0.3-0.5 mm.
[0060] In another specific embodiment of this application, the width of the gas flow channel ridge 111 is 0.3-0.7 mm.
[0061] In another specific embodiment of this application, the width ratio between the gas channel groove 112 and the gas channel ridge 111 is 1.0-1.3.
[0062] In a preferred embodiment of this application, the thickness of the gas diffusion layer of the fuel cell is 0.4-0.5 mm.
[0063] In a preferred embodiment of this application, the depth of the gas flow channel 112 is 0.3-0.4 mm.
[0064] In a preferred embodiment of this application, the width of the gas flow channel ridge 111 is 0.4-0.5 mm.
[0065] In a preferred embodiment of this application, the width ratio between the gas channel groove 112 and the gas channel ridge 111 is 1.0-1.1.
[0066] In specific embodiments of this application, the average pore size of the substrate layer 11 is less than 80 nm; preferably, the average pore size of the substrate layer 11 is less than 60 nm; more preferably, the average pore size of the substrate layer 11 is less than 50 nm.
[0067] In a specific embodiment of this application, the normal permeability of the gas diffusion layer 1 is greater than or equal to 10*10-6 m / Pa•S, and the in-plane permeability of the gas diffusion layer 1 is greater than or equal to 50*10-12 m3 / Pa•S. This ensures that the liquid water in the gas flow channel 112 can be discharged while also ensuring the gas concentration below the shoulder, thereby increasing the oxygen content of the catalyst layer and improving the reaction efficiency of the fuel cell.
[0068] In this embodiment, the fuel cell further includes an anode separator 9, an anode catalyst layer 6, an anode gas diffusion layer 2, and the anode separator 9 stacked in sequence.
[0069] In this embodiment, the cooling plate 4 is provided with a cooling channel 41, which is parallel, perpendicular or intersecting with the anode gas diffusion layer 2.
[0070] In this embodiment, the cathode separator 5 and the anode separator 9 are metal separators or graphite separators.
[0071] In specific embodiments of this application, a metal partition refers to a structural plate made of metal, and a graphite partition refers to a structural plate made of graphene.
[0072] refer to Figure 4 In another embodiment of this application, the cooling electrode plate 4 is provided with a cooling channel 41, which is parallel, perpendicular or intersecting with the anode gas diffusion layer 2; the cooling channel 41 has only a lower channel that is in direct contact with the cathode partition 5, and the non-channel side of the cooling electrode plate 4 is a closed structure.
[0073] In a specific embodiment of this application, by setting the non-flow channel side of the cooling plate 4 as a closed structure, there is no need to set the anode separator 9, thereby reducing the thickness and weight of the fuel cell.
[0074] In a specific embodiment of this application, since a gas flow channel ridge 111 and a gas flow channel groove 112 are provided on the gas diffusion layer 1, the cooling flow channel 41 of the fuel cell can have different configuration forms, thereby enabling the adjustment of the components included in the fuel cell stack.
[0075] In a specific embodiment of this application, the thickness of the cooling plate 4 is 0.4-1.2 mm.
[0076] The fuel cell in this embodiment of the application has the following beneficial effects: By providing a gas flow channel ridge 111 on the side of the gas diffusion layer 1 away from the microporous layer 2, a gas flow channel groove 112 is formed between the gas flow channel ridge 111 and the edge of the gas diffusion layer 1. During the operation of the fuel cell, the water flow in the gas diffusion layer 1 will flow in the vertical and horizontal planes of the gas diffusion layer 1. As a result, some oxygen can be stored in the gas flow channel groove 112, which will not cause the fuel cell to be flooded. This improves the catalytic efficiency of the catalyst layer and thus improves the working efficiency of the fuel cell.
[0077] On the other hand, this application embodiment also provides a fuel cell stack, which includes multiple fuel cells as described in this application embodiment. The multiple fuel cells are stacked together, and their specific structure and beneficial effects are the same as those described above, so they will not be repeated here.
[0078] The foregoing description has fully disclosed the specific embodiments of this application. It should be noted that any modifications made by those skilled in the art to the specific embodiments of this application do not depart from the scope of the claims. Accordingly, the scope of the claims of this application is not limited to the foregoing specific embodiments.
Claims
1. A gas diffusion layer for a fuel cell, characterized in that, It includes a base layer (11) and a microporous layer (2), wherein the base layer (11) and the microporous layer (2) are stacked. The base layer (11) includes a gas flow channel ridge (111), which is disposed on the side away from the microporous layer (2), and the gas flow channel ridge (111) and the edge of the base layer (11) form a gas flow channel groove (112).
2. The gas diffusion layer of the fuel cell according to claim 1, characterized in that, The gas channel grooves (112) on both sides of the airflow channel ridge have different groove widths.
3. The gas diffusion layer of the fuel cell according to claim 1, characterized in that, The gas flow channel (112) includes at least one of a direct flow channel, a meandering flow channel, and a serpentine flow channel.
4. A fuel cell, characterized in that, It includes an anode gas diffusion layer (2), a cathode gas diffusion layer (3), a cooling plate (4), a cathode separator (5), an anode catalyst layer (6), a cathode catalyst layer (7), and a proton exchange membrane (8). The structure of the anode gas diffusion layer (2) and the structure of the cathode gas diffusion layer (3) are the same as those of the gas diffusion layer (1) as described in any one of claims 1-3; The cooling plate (4), the cathode separator (5), the cathode gas diffusion layer (3), the cathode catalyst layer (7), the proton exchange membrane (8), the anode catalyst layer (6), and the anode gas diffusion layer (2) are stacked in sequence.
5. The fuel cell according to claim 4, characterized in that, It also includes an anode partition (9), and the anode catalyst layer (6), the anode gas diffusion layer (2) and the anode partition (9) are stacked in sequence.
6. The fuel cell according to claim 5, characterized in that, The cooling plate (4) is provided with a cooling channel (41), which is parallel, perpendicular or intersecting with the anode gas diffusion layer (2).
7. The fuel cell according to claim 6, characterized in that, The cooling channel (41) includes an upper channel and a lower channel. The coolant in the lower channel is in direct contact with the cathode partition (5), and the coolant in the upper channel is in indirect contact with the cathode partition (5) through the cooling electrode plate (4).
8. The fuel cell according to claim 5, characterized in that, The cathode separator (5) and the anode separator (9) are metal separators or graphite separators.
9. The fuel cell according to claim 4, characterized in that, The cooling plate (4) is provided with a cooling channel (41), which is parallel, perpendicular or intersecting with the anode gas diffusion layer (2); The cooling channel (41) has only one lower channel that is in direct contact with the cathode partition (5), and the non-channel side of the cooling electrode (4) is a closed structure.
10. A fuel cell stack, characterized in that, This includes multiple fuel cells as described in any one of claims 4-9.