Membrane electrode and sealing structure of single battery

Abstract

The utility model discloses a membrane electrode and a sealing structure of a single cell, and relates to the technical field of fuel cells, catalyst layers are arranged on the upper side and the lower side of a proton exchange membrane, inner sealing frame layers are arranged at the two ends of the outer side of each catalyst layer, and outer sealing frame layers are arranged on the outer sides of the inner sealing frame layers; embedding grooves are formed in one end of the inner side of the inner sealing frame layer, a gas diffusion layer is arranged between the corresponding embedding grooves, and a bipolar plate is arranged on the outer side of the gas diffusion layer. The embedded groove can conveniently position the gas diffusion layer, wrinkles are not prone to being generated when the gas diffusion layer is pasted and fixed, in addition, the inner sealing frame layer plays a role in protecting the proton exchange membrane and sealing and supporting, the outer sealing frame layer prevents the gas diffusion layer from being pressed and damaged, and meanwhile the outer sealing frame plays a role in bonding and sealing with the bipolar plate. And the bipolar plate and the membrane electrode are prevented from being sealed in a dispensing or rubber pad manner, so that the fixed assembly and sealing among the components are effectively ensured, the consistency of the overall power generation performance of the stack is good, and the maintenance cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cells, in particular to a sealing structure for a membrane electrode and a single cell. Background Art

[0002] A fuel cell is a power generation device that directly converts the chemical energy existing in a fuel and an oxidant into electrical energy. Fuel cells have the advantages of zero emissions, no vibration and noise, good load responsiveness, high reliability, etc. Fuel cells can generally be divided into alkaline fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, solid oxide fuel cells, proton exchange membrane fuel cells, etc.; among them, proton exchange membrane fuel cells have high energy conversion efficiency, can be quickly started at room temperature, have no electrolyzed water loss, and have a long service life. In recent years, they have developed rapidly and have received increasing attention.

[0003] The core components of a proton exchange membrane fuel cell include a first-side catalyst layer of the fuel cell, a proton exchange membrane, a second-side catalyst layer, an upper frame, a lower frame, and gas diffusion layers on both sides. The manufacturing process of a fuel cell membrane electrode generally includes catalyst pulping, catalyst layer coating, frame fitting, gas diffusion layer coating, and gas diffusion layer fitting; the proton exchange membrane is very sensitive to temperature and humidity and is prone to deformation with changes in ambient temperature and humidity. In addition to improving the membrane strength of the effective area of the electrode to stabilize the size of the membrane electrode, the frame can also prevent direct contact between the proton membrane and the plate electrode from causing mechanical damage and affecting the service life of the entire fuel cell. Therefore, an effective sealing frame can greatly improve the operation reliability and service life of the fuel cell.

[0004] In the prior art, generally, both sides of a certain size around the blank area and the catalytic layer are directly attached to the upper frame and the lower frame respectively, and then glue is applied on the bipolar plate to bond and seal with the upper and lower frames. When assembling the stack, due to the compressive deformation of the gas diffusion layer (carbon paper) of the membrane electrode, the membrane electrode single cell in the stack is also unevenly stressed, resulting in poor performance consistency and affecting the overall power generation performance of the stack. During the long-term operation of the stack, the membrane electrode is under pressure for a long time. In the conventional sealing structure, the sealing frame is much thinner than the carbon paper, and it is difficult to ensure that hundreds of membrane electrodes are in a state with better consistency, resulting in overpressure or low performance of some membrane electrodes, and the stack has to be abnormally repaired, greatly increasing the operation and maintenance costs. Summary of the Invention

[0005] The technical problem to be solved by the utility model is: aiming at the deficiencies existing in the prior art, to provide a sealing structure for a membrane electrode and a single cell, with good consistency in the overall power generation performance of the stack and low maintenance costs.

[0006] To solve the above technical problem, the technical solution of the utility model is:

[0007] A sealing structure for a membrane electrode and a single cell, including a proton exchange membrane, catalyst layers are provided on both the upper and lower sides of the proton exchange membrane, inner sealing frame layers are provided at both outer ends of the two catalyst layers, and outer sealing frame layers are provided on the outer sides of several of the inner sealing frame layers;

[0008] An embedding groove is provided at one inner end of the inner sealing frame layer, a gas diffusion layer is provided between the corresponding two embedding grooves, and a bipolar plate is provided on the outer side of the gas diffusion layer.

[0009] As an improved technical solution, the height of the outer sealing frame layer is adapted to the height of the corresponding gas diffusion layer after compression.

[0010] As an improved technical solution, the upper end of the outer sealing frame layer abuts against the bipolar plate.

[0011] As an improved technical solution, both ends of the gas diffusion layer respectively abut against the corresponding outer sealing frame layers.

[0012] As an improved technical solution, the thickness of the inner sealing frame layer is 35 - 50 μm.

[0013] As an improved technical solution, the thickness of the outer sealing frame layer is 90 - 150 μm.

[0014] As a preferred technical solution, the outer sealing frame layer and the inner sealing frame layer are both PEN, PI, PPS or PET films with double-sided coating.

[0015] As a preferred technical solution, the outer frame is provided with flow field inlets and outlets adapted to the bipolar plate.

[0016] As a preferred technical solution, the inner sealing frame layer and the outer sealing frame layer are both PEN, PI, PPS or PET films with double-sided coating.

[0017] Due to the adoption of the above technical solutions, the beneficial effects of the present utility model are:

[0018] A sealing structure for a membrane electrode and a single cell of the present utility model includes a proton exchange membrane. Catalyst layers are provided on both the upper and lower sides of the proton exchange membrane. Inner sealing frame layers are provided at both outer ends of the two catalyst layers. Outer sealing frame layers are provided on the outer sides of several of the inner sealing frame layers. An embedding groove is provided at one inner end of the inner sealing frame layer. A gas diffusion layer is provided between the corresponding two embedding grooves. A bipolar plate is provided on the outer side of the gas diffusion layer. The embedding groove can facilitate the positioning of the gas diffusion layer and is not prone to wrinkles during pasting and fixing. In addition, the inner sealing frame layer plays a role in protecting the proton exchange membrane and providing sealing support. The outer sealing frame layer prevents the gas diffusion layer from being damaged by pressure. At the same time, the outer sealing frame plays a role in bonding and sealing with the bipolar plate, avoiding the use of methods such as dotting glue or rubber pads for sealing between the bipolar plate and the membrane electrode, effectively ensuring the fixed assembly and sealing between components, with good consistency in the overall power generation performance of the stack and low maintenance costs.

[0019] The height of the outer sealing frame layer of the present utility model is adapted to the height of the corresponding gas diffusion layer after compression. The outer sealing frame layer is used to match the thickness of the gas diffusion layer after compression, making the membrane electrode become a plane after compression, effectively preventing the gas diffusion layer from being damaged due to excessive pressure of the stack, realizing effective support for the gas diffusion layer, and ensuring the consistency of the stack formed after stacking.

[0020] The upper end of the outer sealing frame layer abuts against the bipolar plate, and both ends of the gas diffusion layer respectively abut against the corresponding outer sealing frame layers. The gas diffusion layer can be better positioned. At the same time, the inner sealing frame layer and the outer sealing frame layer paste and fix both ends and the lower part of the gas diffusion layer at the same time, and the fixing effect of the gas diffusion layer is better and the stability is good.

[0021] The thickness of the inner sealing frame layer is 35 - 50 μm, and the thickness of the outer sealing frame layer is 90 - 150 μm, which better matches the proton exchange membrane and the gas diffusion layer, and has a good use effect.

[0022] Both the outer sealing frame layer and the inner sealing frame layer are provided with several corresponding positioning holes. Through the positioning holes, the positions of each component can be accurately positioned and connected during the assembly of the stack, so as to avoid poor consistency caused by assembly misalignment and improve the power generation performance of the stack.

[0023] The outer sealing frame layer is provided with flow field inlets and outlets adapted to the bipolar plate for classifying and passing various gases and water entering and leaving the stack in different zones.

[0024] Both the inner sealing frame layer and the outer sealing frame layer are PEN, PI, PPS or PET films with glue coated on both sides. The bipolar plate and the outer sealing frame layer, the outer sealing frame layer and the inner sealing frame layer, and the proton exchange membrane and the inner sealing frame layer are all fixed by gluing, making the structure more stable. Description of the Drawings

[0025] The present utility model will be further described below in conjunction with the drawings and embodiments.

[0026] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;

[0027] Figure 2 is a schematic structural diagram of the outer sealing frame layer in Embodiment 1;

[0028] Figure 3 is a schematic structural diagram of the inner sealing frame layer in Embodiment 1;

[0029] Wherein: 1, proton exchange membrane; 2, inner sealing frame layer; 3, outer sealing frame layer; 4, catalyst layer; 5, bipolar plate; 6, embedding groove; 7, positioning hole; 8, flow field inlet and outlet; 9, gas diffusion layer. Specific Embodiments

[0030] The present utility model will be further elaborated below in conjunction with the drawings and embodiments.

[0031] As Figures 1-3 shown, a sealing structure of a membrane electrode and a single cell includes a proton exchange membrane 1. Catalyst layers 4 are provided on both the upper and lower sides of the proton exchange membrane 1. Inner sealing frame layers 2 are provided at both outer ends of the two catalyst layers 4. Outer sealing frame layers 3 are provided on the outer sides of several inner sealing frame layers 2. An embedding groove 6 is provided at one inner end of the inner sealing frame layer 2. A gas diffusion layer 9 is provided between the corresponding two embedding grooves 6. A bipolar plate 5 is provided on the outer side of the gas diffusion layer 9. The embedding groove 6 can facilitate the positioning of the gas diffusion layer 9 and is not prone to generating wrinkles during pasting and fixing. In addition, the inner sealing frame layer 2 plays a role in protecting the proton exchange membrane 1 and providing sealing support. The outer sealing frame layer 3 prevents the gas diffusion layer 9 from being damaged by pressure. At the same time, the outer sealing frame plays a role in bonding and sealing with the bipolar plate 5, avoiding using methods such as dot gluing or rubber pads to seal between the bipolar plate 5 and the membrane electrode, effectively ensuring the fixed assembly and sealing between components, having good consistency in the overall power generation performance of the stack and low maintenance costs.

[0032] The height of the outer sealing frame layer 3 is adapted to the height of the corresponding side of the gas diffusion layer 9 after compression. The outer sealing frame layer 3 is used to match the thickness of the gas diffusion layer 9 after compression, so that the membrane electrode becomes a plane after compression, effectively preventing damage to the gas diffusion layer 9 caused by excessive pressure of the stack, realizing effective support for the gas diffusion layer 9, and ensuring the consistency of the stack formed after stacking.

[0033] The upper end of the outer sealing frame layer 3 abuts against the bipolar plate 5, and both ends of the gas diffusion layer 9 respectively abut against the corresponding outer sealing frame layer 3. The gas diffusion layer 9 can be better positioned. At the same time, the inner sealing frame layer 2 and the outer sealing frame layer 3 paste and fix both ends and the lower part of the gas diffusion layer 9 at the same time, so that the fixing effect of the gas diffusion layer 9 is better and the stability is good.

[0034] The thickness of the inner sealing frame layer 2 is 35 - 50 μm, and the thickness of the outer sealing frame layer 3 is 90 - 150 μm, which better matches the proton exchange membrane 1 and the gas diffusion layer 9, and has a good use effect.

[0035] Both the outer sealing frame layer 3 and the inner sealing frame layer 2 are provided with a number of adapted positioning holes 7. Through the positioning holes 7, the positions of each component can be accurately positioned and connected during the assembly of the stack, so as to avoid poor consistency caused by assembly misalignment and improve the power generation performance of the stack.

[0036] The outer sealing frame layer 3 is provided with flow field inlets and outlets 8 adapted to the bipolar plate 5, which are used for classifying and passing various gases and water entering and leaving the stack in different zones.

[0037] Both the inner sealing frame layer 2 and the outer sealing frame layer 3 are PEN, PI, PPS or PET films with double-sided glue coating. The bipolar plate 5 and the outer sealing frame layer 3, the outer sealing frame layer 3 and the inner sealing frame layer 2, and the proton exchange membrane 1 and the inner sealing frame layer 2 are all fixed by gluing, and the structure is more stable.

[0038] It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A sealing structure for a membrane electrode and a single cell, characterized in that: It includes a proton exchange membrane, catalyst layers are provided on both the upper and lower sides of the proton exchange membrane, inner sealing frame layers are provided at both outer ends of the two catalyst layers, and outer sealing frame layers are provided on the outer sides of a plurality of the inner sealing frame layers; An embedding groove is provided at one inner end of the inner sealing frame layer, a gas diffusion layer is provided between the corresponding two embedding grooves, and a bipolar plate is provided on the outer side of the gas diffusion layer.

2. The sealing structure of a membrane electrode and a single cell according to claim 1, characterized in that: The height of the outer sealing frame layer is adapted to the height of the corresponding gas diffusion layer after compression.

3. The sealing structure of a membrane electrode and a single cell according to claim 1, characterized in that: The upper end of the outer sealing frame layer abuts against the bipolar plate.

4. A sealing structure of a membrane electrode and a single cell according to claim 1, characterized in that: Both ends of the gas diffusion layer respectively abut against the corresponding outer sealing frame layer.

5. A sealing structure for a membrane electrode and a single cell as described in claim 1, characterized in that: The thickness of the inner sealing frame layer is 35 - 50 μm.

6. A sealing structure for a membrane electrode and a single cell as described in claim 1, characterized in that: The thickness of the outer sealing frame layer is 90 - 150 μm.

7. A sealing structure for a membrane electrode and a single cell according to claim 1, characterized in that: Both the outer sealing frame layer and the inner sealing frame layer are provided with a plurality of corresponding positioning holes.

8. A sealing structure for a membrane electrode and a single cell according to claim 1, characterized in that: The outer sealing frame layer is provided with flow field inlets and outlets adapted to the bipolar plate.

9. A sealing structure for a membrane electrode and a single cell according to claim 1, characterized in that: Both the inner sealing frame layer and the outer sealing frame layer are PEN, PI, PPS or PET films with double-sided coating of glue.

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