A fuel cell membrane electrode structure
Patent Information
- Application Number
- CN202521837222.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-28
- Publication Date
- 2026-10-16
- Estimated Expiration
- 2035-08-28
AI Technical Summary
[0004]为了弥补以上不足，本实用新型提供了一种燃料电池膜电极结构，旨在改善了现有技术中“气体扩散层(GDL)与催化剂膜(CL)接触不良导致接触电阻过大”的问题
[0019] 1. In this utility model, the conductive transition layer adopts a microporous or mesh structure to enhance the contact area and conductivity between the gas diffusion layer and the catalyst film, reduce the contact resistance, and form a gradient pressure distribution through the arc surface design of the gas diffusion layer and the catalyst film to ensure that the pressure between the gas diffusion layer and the catalyst film gradually increases from the edge to the center, avoid poor local contact, and ensure that the two maintain good contact under dynamic working conditions.
Smart Images
Figure CN224862250U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of fuel cell membrane electrode, and in particular to a fuel cell membrane electrode structure. Background Technology
[0002] As a highly efficient and clean energy conversion device, the performance of the core component of a fuel cell, the membrane electrode assembly (MEA), directly determines the cell's output power and lifespan. The MEA mainly consists of a gas diffusion layer (GDL), a catalyst membrane (CL, including a proton exchange membrane), and a frame structure. Its encapsulation process typically employs methods such as lamination and injection molding, with each layer bonded together through hot pressing.
[0003] However, in existing membrane electrode assemblies, when the gas diffusion layer (GDL) is bonded to the frame using a dispensing process, there is a problem of poor contact between the gas diffusion layer and the catalyst membrane, resulting in excessive contact resistance and affecting the performance of the membrane electrode assemblies. To address this issue, a fuel cell membrane electrode assemblies structure is proposed. Utility Model Content
[0004] To overcome the above deficiencies, this utility model provides a fuel cell membrane electrode structure, which aims to improve the problem of "poor contact between the gas diffusion layer (GDL) and the catalyst membrane (CL) leading to excessive contact resistance" in the prior art.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: a fuel cell membrane electrode structure, including an outer frame a, an outer frame b disposed at the lower part of the outer frame a, a gas diffusion layer disposed on the inner wall of the outer frame a and the outer frame b, a catalyst membrane disposed below the gas diffusion layer, the gas diffusion layer and the catalyst membrane being stacked one on top of the other, a conductive transition layer being embedded in the middle of the gas diffusion layer and the catalyst membrane, the lower part of the gas diffusion layer and the upper part of the catalyst membrane being configured as an arc surface that gradually arches towards the middle, and auxiliary components being disposed on the outer sides of both the outer frame a and the outer frame b.
[0006] As a further description of the above technical solution:
[0007] The auxiliary component includes a fastener a, which is fixedly connected to the corner of the outer frame a and the outer frame b. Multiple sets of fasteners b are fixedly connected to the middle of the outer frame a and the outer frame b. The multiple sets of fasteners b are symmetrically arranged on the front and rear sides of the outer frame a, and a connector is fixedly connected to the outer side of two adjacent sets of fasteners b.
[0008] As a further description of the above technical solution:
[0009] The fastener a is configured in an L shape.
[0010] As a further description of the above technical solution:
[0011] The fastener b is configured in a U-shape.
[0012] As a further description of the above technical solution:
[0013] The lower parts of the fixing member a, fixing member b, and connector are all designed as inverted trapezoids.
[0014] As a further description of the above technical solution:
[0015] The fixing element a, fixing element b, and connector are in contact with the gas diffusion layer and the outer side of the catalyst film.
[0016] As a further description of the above technical solution:
[0017] The surface of the conductive transition layer is configured with micropores or a mesh structure.
[0018] This utility model has the following beneficial effects:
[0019] 1. In this utility model, the conductive transition layer adopts a microporous or mesh structure to enhance the contact area and conductivity between the gas diffusion layer and the catalyst film, reduce the contact resistance, and form a gradient pressure distribution through the arc surface design of the gas diffusion layer and the catalyst film to ensure that the pressure between the gas diffusion layer and the catalyst film gradually increases from the edge to the center, avoid poor local contact, and ensure that the two maintain good contact under dynamic working conditions.
[0020] 2. In this utility model, the auxiliary components cooperate with the outer frame a and the outer frame b to form an all-round fixation of the gas diffusion layer and the catalyst film, which not only improves the overall structure but also further avoids poor local contact. Attached Figure Description
[0021] Figure 1 This is a three-dimensional structural diagram of the overall device in this utility model;
[0022] Figure 2 This is a three-dimensional structural diagram of the disassembled integral device in this utility model;
[0023] Figure 3 This is a three-dimensional structural diagram of the disassembled auxiliary components in this utility model.
[0024] Legend:
[0025] 1. Outer frame a; 2. Outer frame b; 3. Gas diffusion layer; 4. Auxiliary components; 41. Fixing component a; 42. Fixing component b; 43. Connecting component; 5. Catalyst film; 6. Conductive transition layer. Detailed Implementation
[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0027] Reference Figures 1-3 This utility model provides an embodiment of a fuel cell membrane electrode structure, including an outer frame a1, with an outer frame b2 disposed below the outer frame a1. The outer frames a1 and b2 are made of rigid insulating material (such as engineering plastic or ceramic), possessing chemical corrosion resistance and thermal stability, fixing a gas diffusion layer 3, a catalyst membrane 5, and auxiliary components 4, forming an overall rigid structure of the membrane electrode. The gas diffusion layer 3, made of porous carbon fiber paper / cloth, is disposed on the inner wall of the outer frames a1 and b2, possessing high conductivity, gas permeability, and mechanical strength, providing a uniform diffusion path for hydrogen (anode) and oxygen (cathode), ensuring that the reactant gases reach the surface of the catalyst membrane 5; acting as an electronic conductor, it collects electrons generated by the catalyst layer and conducts them to the external circuit; it discharges water generated during the reaction (cathode) through the porous structure, preventing water poisoning of the catalyst membrane. Below the gas diffusion layer 3 is the catalyst membrane 5, which includes a proton exchange membrane (such as Nafion) and catalyst layers (platinum-based catalysts) on both sides. The anode catalyst layer promotes the oxidation of hydrogen to generate protons and electrons (H2→2H). + +2e - The cathode catalytic layer promotes the reduction of oxygen and its combination with protons to produce water (O2 + 4H2O). + +4e - →2H2O); the proton exchange membrane acts as a proton (H + The conduction channel blocks electrons from passing directly, forcing them to form a current through the external circuit; the upper arc surface design works in conjunction with the gas diffusion layer 3, and the gradient pressure ensures a tight fit with the conductive transition layer 6, reducing contact resistance.
[0028] Reference Figures 1-3The gas diffusion layer 3 and the catalyst film 5 are stacked one on top of the other. A conductive transition layer 6 is embedded in the middle of the gas diffusion layer 3 and the catalyst film 5. The surface of the conductive transition layer 6 is set with a microporous or mesh structure. The conductive transition layer 6 is made of conductive materials such as carbon nanotubes / graphene with a thickness of 5-20μm. The porous / mesh structure fills the microscopic gaps between the gas diffusion layer 3 and the catalyst film 5, thereby increasing the effective contact area by 30% to 50%. The highly conductive material directly bridges the gas diffusion layer 3 (carbon fiber) and the catalyst film 5 (platinum particles), shortening the electron conduction path and reducing the contact resistance by 40% to 60%. The porous structure does not hinder gas diffusion and moisture discharge, maintaining the efficiency of the electrochemical reaction. The lower part of the gas diffusion layer 3 and the upper part of the catalyst film 5 are set with an arc surface that gradually arches towards the center. During hot pressing, a pressure gradient is formed from the edge to the center (low pressure at the edge maintains porosity, and high pressure at the center strengthens the contact). Auxiliary components 4 are set on the outer sides of the outer frame a1 and the outer frame b2.
[0029] Reference Figures 1-3 The auxiliary component 4 includes a fixing member a41, which is fixedly connected to the corners of the outer frame a1 and the outer frame b2. The fixing member a41 is L-shaped, and the L-shaped structure provides bidirectional fixing force in the corner area to prevent warping or delamination of the membrane electrode edge. Multiple sets of fixing members b42 are fixedly connected to the middle of the outer frame a1 and the outer frame b2. The fixing members b42 are U-shaped and are symmetrically arranged on the front and rear sides of the outer frame a1. Connecting members 43 are fixedly connected to the outer sides of adjacent sets of fixing members b42. The fixing members b42 laterally constrain the edges of the gas diffusion layer 3 and the catalyst membrane 5. The connecting members 43 connect adjacent fixing members b42 to form a continuous lateral support band, which enhances the structural integrity of the middle area. The lower parts of the fixing members a41, fixing members b42 and connecting members 43 are all set as inverted trapezoids to reduce the contact area, thereby reducing the impact on the working efficiency of the membrane electrode. The fixing members a41, fixing members b42 and connecting members 43 are in contact with the outer sides of the gas diffusion layer 3 and the catalyst membrane 5.
[0030] Working principle: During use, the anodic reaction (inside the gas diffusion layer 3) occurs, and hydrogen (H2) diffuses through the porous structure of the gas diffusion layer 3 to the anodic catalyst layer of the catalyst membrane 5; under the action of the platinum-based catalyst, hydrogen undergoes an oxidation reaction: H2 → 2H + +2e - The generated protons (H + Electrons are conducted to the cathode through the proton exchange membrane. - The gas is collected through the gas diffusion layer 3 and flows to the cathode through the external circuit, forming an electric current.
[0031] In the cathode reaction (inside gas diffusion layer 3), oxygen (O2) diffuses through the gas diffusion layer 3 on the other side to the cathode catalytic layer of the catalyst membrane 5; electrons conducted by the external circuit combine with protons transmitted from the proton exchange membrane, and a reduction reaction occurs under the action of the catalyst: O2 + 4H+ + +4e - →2H2O; The water generated by the reaction is discharged through the pores of the gas diffusion layer 3 to avoid water poisoning.
[0032] The conductive transition layer 6 serves as a conductive bridge between the gas diffusion layer 3 (carbon fiber) and the catalyst film 5 (platinum particles). Its microporous / mesh structure shortens the electron transport path, reduces contact resistance, and ensures efficient electron conduction.
[0033] The arched design of the lower part of the gas diffusion layer 3 and the upper part of the catalyst film 5 creates a gradient distribution of pressure applied by the outer frame a1 / outer frame b2 during hot pressing, with a lower pressure at the edges and a higher pressure at the center: Edge region: small curvature of the arc surface, pressure concentrated near the outer frame, GDL porosity maintained at 60%~70%, ensuring smooth gas diffusion; Center region: large curvature of the arc surface, pressure concentrated at the interface between the conductive transition layer 6 and the catalyst layer, forcing the two to fit tightly together, increasing the contact area to over 95%.
[0034] When changes in battery temperature / humidity cause material deformation (such as the expansion of a proton exchange membrane due to moisture absorption), the arc-shaped structure automatically adjusts the pressure distribution through minute elastic deformation, avoiding interface delamination caused by rigid contact and maintaining long-term stable contact.
[0035] L-shaped fastener a41 is installed at the corner of the outer frame. The L-shaped structure provides bidirectional mechanical locking to prevent warping of the membrane electrode edge due to thermal pressure or working stress, ensuring reliable edge sealing. U-shaped fastener b42 and connector 43 provide central support. The U-shaped fastener b42 is symmetrically distributed in the middle of the outer frame, laterally constraining the edges of the gas diffusion layer 3 and catalyst membrane 5. The connector 43 forms a continuous support band, uniformly transmitting edge pressure to the center.
[0036] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A fuel cell membrane electrode structure, comprising an outer frame a (1), characterized in that: The outer frame a (1) is provided with an outer frame b (2) at its lower part. A gas diffusion layer (3) is provided on the inner wall of the outer frame a (1) and the outer frame b (2). A catalyst film (5) is provided below the gas diffusion layer (3). The gas diffusion layer (3) and the catalyst film (5) are stacked one on top of the other. A conductive transition layer (6) is embedded in the middle of the gas diffusion layer (3) and the catalyst film (5). The lower part of the gas diffusion layer (3) and the upper part of the catalyst film (5) are set as arc surfaces that gradually arch towards the middle. Auxiliary components (4) are provided on the outer sides of both a (1) and the outer frame b (2). The auxiliary components (4) include fasteners a (41). The fasteners a (41) are fixedly connected to the corners of the outer frame a (1) and the outer frame b (2). Multiple sets of fasteners b (42) are fixedly connected to the middle of both the outer frame a (1) and the outer frame b (2). The multiple sets of fasteners b (42) are symmetrically arranged on the front and rear sides of the outer frame a (1). Connectors (43) are fixedly connected to the outer sides of two adjacent sets of fasteners b (42).
2. The fuel cell membrane electrode structure according to claim 1, characterized in that: The fastener a (41) is configured in an L shape.
3. The fuel cell membrane electrode structure according to claim 1, characterized in that: The fastener b (42) is configured in a U-shape.
4. The fuel cell membrane electrode structure according to claim 1, characterized in that: The lower parts of the fixing member a (41), fixing member b (42) and connecting member (43) are all configured as inverted trapezoids.
5. The fuel cell membrane electrode structure according to claim 1, characterized in that: The fasteners a (41), b (42), and 43 are in contact with the outside of the gas diffusion layer (3) and the catalyst film (5).
6. The fuel cell membrane electrode structure according to claim 1, characterized in that: The surface of the conductive transition layer (6) is configured with micropores or a mesh structure.