Monocell structure of fuel cell

Abstract

The utility model discloses a single cell structure of a fuel cell, which comprises an anode plate, a membrane electrode and a cathode plate which are sequentially laminated, an anode sealing structure is arranged between the anode plate and the membrane electrode, and a cathode sealing structure is arranged between the membrane electrode and the cathode plate. The anode sealing structure and the cathode sealing structure are integrated sealing rubber strip structures formed by semi-vulcanization injection molding, the anode plate, the membrane electrode and the cathode plate form an integrated single cell unit through the anode sealing structure and the cathode sealing structure, and edge rubber coating for integral sealing is arranged at the edge part of the single cell unit. The single cell of the fuel cell is reasonable in structural design, so that the anode field sealing rubber strip is in a semi-vulcanization state and the cathode plate gas field is in a semi-vulcanization state when the polar plate is formed, water field sealing and gas field sealing are formed at one time more conveniently, an assembly galvanic pile is simplified, the assembly accumulated tolerance is reduced, the consistency is improved, and the cost is relatively low.

Description

Technical Field

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

[0002] As one of the most promising and popular fuel cell technologies at present, the proton exchange membrane fuel cell (PEMFC) has many advantages such as no pollution, high energy conversion rate, short charging time, low working temperature, and low noise, and can be widely used in many fields such as transportation vehicles, combined heat and power, fixed base stations, mobile portable devices, unmanned aerial vehicles, and military equipment. At present, the main structure of the stack product is the bipolar plate-membrane electrode bipolar plate stacking method. In this part, the bipolar plate and the membrane electrode are independent components, and only rely on the pressing force for sealing, with low reliability. Moreover, due to the large number of components, the cumulative tolerance generated during stacking also seriously affects the stacking quality.

[0003] The existing power generation unit of the fuel cell is composed of a bipolar plate-membrane electrode-bipolar plate stack. The commonly used bipolar plates are in welding process or direct press fitting. Welded bipolar plates are prone to problems such as weld penetration, ablation, weld slag splashing, and poor weld quality. The direct press fitting of bipolar plates relies entirely on pressing for sealing, with low reliability. The traditional sealing molding mainly relies on directly bonding the sealing ring or injection molding the sealing ring. The bonded sealing ring is prone to failure after multiple disassembly. The injection molded sealing ring currently uses silicone rubber material in China, with high air permeability and moisture permeability, which affects the insulation of the stack. Currently, the single cell process mainly includes: 1. Glue bonding, but its bonding reliability is low and the requirements for glue are high. 2. Low-pressure injection molding of silicone rubber. The silicone rubber bonding has good air permeability and moisture permeability, which will easily cause problems with the insulation of the stack.

[0004] To solve the above problems, there is also an integrated sealing structure at present. For example, a low-leakage integrated single fuel cell sealing structure disclosed in Chinese Patent CN116525872A includes: a bipolar plate and a membrane electrode. The membrane electrode includes a proton exchange membrane, carbon paper, and a catalytic layer. A membrane frame is also provided on the side of the proton exchange membrane, and the membrane frame can be hermetically fitted with the bipolar plate; the cathode main board, the membrane electrode, and the anode main board are integrally formed by sealing injection molding, and the sealing glue line is closely fitted with the membrane electrode frame; the molding is complex and the cost is relatively high. Summary of the Utility Model

[0005] Aiming at the deficiencies of the prior art, the utility model provides a fuel cell single cell structure to achieve the purpose of simple forming and assembly and relatively low cost.

[0006] To solve the above technical problems, the technical solution adopted by the utility model is as follows:

[0007] The fuel cell single cell structure includes an anode plate, a membrane electrode, and a cathode plate that are stacked in sequence. An anode sealing structure is provided between the anode plate and the membrane electrode, and a cathode sealing structure is provided between the membrane electrode and the cathode plate. Both the anode sealing structure and the cathode sealing structure are integrally sealed rubber strip structures formed by semi-vulcanized injection molding. The anode plate, the membrane electrode, and the cathode plate form an integral single cell unit through the anode sealing structure and the cathode sealing structure, and an edge rubber coating for overall sealing is provided at the edge of the single cell unit.

[0008] Further:

[0009] The front surface of the anode plate of the single cell unit is provided with a water field b surface, and the back surface of the cathode plate of the single cell unit is provided with a water field a surface. The two water field surfaces of adjacent single cell units form a water cavity, and a water field sealing rubber strip is provided at the edge of the water cavity.

[0010] One end of the anode plate is provided with a hydrogen cavity inlet, and the other end is provided with a hydrogen cavity outlet. The anode plate and the membrane electrode cooperate to form a hydrogen field, and the anode sealing structure is an integrally sealed rubber strip structure corresponding to the hydrogen cavity inlet, the hydrogen cavity outlet, and the edge of the hydrogen field.

[0011] One end of the cathode plate is provided with an air cavity inlet, and the other end is provided with an air cavity outlet. The cathode plate and the membrane electrode cooperate to form an air field, and the cathode sealing structure is an integrally sealed rubber strip structure corresponding to the air cavity inlet, the air cavity outlet, and the edge of the air field.

[0012] Sealing grooves are provided on the front surface of the anode plate and the back surface of the cathode plate corresponding to the water field sealing rubber strip.

[0013] The integrally sealed rubber strip structure is an overall frame-shaped sealing strip.

[0014] The water field sealing rubber strip and the sealing groove are sealed by crimping.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] The fuel cell single cell structure is reasonably designed, so that the anode field sealing rubber strip is in a semi-vulcanized state during the forming of the electrode plate, and the cathode plate gas field is in a semi-vulcanized state. The water field sealing and the gas field sealing are more convenient to be formed at one time, which simplifies the assembly of the stack, reduces the assembly cumulative tolerance, improves the consistency, and has a relatively low cost. Description of the Drawings

[0017] The following briefly describes the content expressed by each drawing in this specification and the marks in the drawings:

[0018] Figure 1 It is a schematic diagram of the single cell structure of the present invention.

[0019] Figure 2Schematic diagram of the upper surface of a single cell of the present utility model.

[0020] Figure 3 Schematic diagram of the lower surface of a single cell of the present utility model.

[0021] Figure 4 Exploded schematic diagram of the structure of a single cell of the present utility model.

[0022] Figure 5 Schematic diagram of the sealing process flow of a single cell of the present utility model.

[0023] In the figure:

[0024] 1. Sealing groove, 2. Insertion position, 3. Water chamber inlet, 4. Air chamber outlet, 5. Air chamber inlet, 6. Water chamber outlet, 7. Hydrogen chamber outlet, 8. Hydrogen chamber inlet, 9. b surface of the water field, 10. a surface of the water field, 11. Water field sealing rubber strip, 12. Edge rubber coating, 13. Anode plate, 14. Hydrogen field sealing rubber strip, 15. Membrane electrode, 16. Air field sealing rubber strip, 17. Cathode plate. Specific embodiments

[0025] The following will further describe in detail the specific embodiments of the present utility model by describing the embodiments with reference to the accompanying drawings.

[0026] As Figures 1 to 5 shown, the fuel cell single cell structure includes an anode plate 13, a membrane electrode 15, and a cathode plate 17 stacked in sequence. An anode sealing structure is provided between the anode plate and the membrane electrode, and a cathode sealing structure is provided between the membrane electrode and the cathode plate.

[0027] Both the anode sealing structure and the cathode sealing structure are integral sealing rubber strip structures formed by semi-vulcanized injection molding. The anode plate, the membrane electrode, and the cathode plate form an overall single cell unit through the anode sealing structure and the cathode sealing structure, and an edge rubber coating 12 for overall sealing is provided at the edge of the single cell unit.

[0028] The fuel cell single cell structure of the present utility model is reasonably designed, so that the anode field sealing rubber strip is in a semi-vulcanized state when the electrode plate is formed, and the cathode plate gas field is in a semi-vulcanized state. The water field sealing and the gas field sealing are more convenient to be formed at one time, which simplifies the assembly of the fuel cell stack, reduces the cumulative tolerance of the assembly, improves the consistency, and has a relatively low cost; the formed single cell unit is integrally sealed through the edge rubber coating; it solves the problem of low reliability of the bonded and sealed single cell and the problem of moisture permeability of the silicone-sealed single cell; and it simplifies the assembly of the battery, reduces the assembly difficulty, and improves the working efficiency.

[0029] On the front side of the anode plate of a single cell unit, there is a water field b surface 9, and on the back side of the cathode plate of the single cell unit, there is a water field a surface 10. The two water field surfaces of adjacent single cell units form a water cavity, and a water field sealing rubber strip is provided at the edge of the water cavity; corresponding to the water field, there are a water cavity inlet 3 and a water cavity outlet 6; further, sealing grooves 1 are provided on the front side of the anode plate and the back side of the cathode plate corresponding to the water field sealing rubber strip; the water field sealing rubber strip and the sealing grooves are sealed by crimping, and the assembly is simple.

[0030] At one end of the anode plate, there is a hydrogen cavity inlet 8, and at the other end, there is a hydrogen cavity outlet 7. The anode plate and the membrane electrode cooperate to form a hydrogen field, and the anode sealing structure is an integral sealing rubber strip structure corresponding to the hydrogen cavity inlet, the hydrogen cavity outlet, and the edge of the hydrogen field.

[0031] At one end of the cathode plate, there is an air cavity inlet 5, and at the other end, there is an air cavity outlet 4. The cathode plate and the membrane electrode cooperate to form an air field, and the cathode sealing structure is an integral sealing rubber strip structure corresponding to the air cavity inlet, the air cavity outlet, and the edge of the air field.

[0032] The integral sealing rubber strip structure is an overall frame-shaped sealing strip. The edge of the overall frame-shaped sealing strip corresponding to each inlet and outlet has a sealing area, with a compact structure and good integrity. It reduces the cumulative error caused by the traditional stacking method, avoids the quality defects of welded bipolar plates, solves the problem of poor insulation performance caused by traditional sealing's moisture permeability and air permeability, and improves the reliability of the single cell structure.

[0033] The specific implementation steps are as follows:

[0034] The core of the fuel cell stack in this solution is composed of multiple single cells stacked. The upper surface of the single cell is the water field b surface 9, and the lower surface is the water field a surface 10. The two cooperate to form a cooling cavity, and each single cell is the actual power generation unit.

[0035] The single cell mainly consists of an anode plate 13, a hydrogen field sealing rubber strip 14, a membrane electrode 15, an air field sealing rubber strip 16, a cathode plate 17, and a water field sealing rubber strip 11, and has a sealing groove 1, an insertion position 2, a water cavity inlet 3, an air cavity outlet 4, an air cavity inlet 5, a water cavity outlet 6, a hydrogen cavity outlet 7, a hydrogen cavity inlet 8, a water field b surface 9, a water field a surface 10, etc.

[0036] The anode plate 13 is divided into a front side and a back side. The front side is the water field b surface 9, and the back side is the hydrogen field. Hydrogen enters the hydrogen field of the single cell through the hydrogen inlet cavity body, and the exhaust gas is discharged through the hydrogen cavity outlet 8 after the reaction.

[0037] Rely on the hydrogen field to seal and bond the membrane electrode 15 to the back side of the anode plate to complete the hydrogen side seal.

[0038] The cathode plate 17 is divided into front and back sides. The front side is the air field, and the back side is the water field a surface 10. Air enters the air field of the single cell through the air chamber inlet 5 and the exhaust gas is discharged through the air chamber outlet 4 after the reaction.

[0039] Relying on the air field to seal and bond with the front membrane electrode 15 of the cathode plate, the air side seal is completed.

[0040] The air field sealing structure, the water field sealing strip 11 and the edge rubber coating 12 are integrated. The edge rubber coating can further increase the bonding force of the single cell and improve the reliability and insulation performance of the single cell.

[0041] The water field sealing strip 11 is combined with the back water field a surface of the cathode plate and the front water field b surface of the anode plate by crimping. The water field sealing strip 11 matches the sealing groove 1 to increase the sealing performance. The coolant enters the cooling chamber from the water chamber inlet 3 and is discharged from the water chamber outlet 6.

[0042] The anode plate seal is carried out by an injection molding process. The viscosity of the EPDM material is reduced, and at the same time, by increasing the mold injection port, the EPDM material is formed on the anode plate by using pressure. After forming, the EPDM is processed into a semi-vulcanized state.

[0043] The cathode plate seal also adopts the injection molding process. This EPDM material is injection molded onto the cathode plate. In this step, double-sided injection molding is carried out simultaneously to complete the forming of the air field sealing ring, the water field sealing ring and the edge rubber coating in one step. After forming, the EPDM is processed into a semi-vulcanized state;

[0044] The semi-vulcanized anode plate and cathode plate are bonded to the membrane electrode. While cooling the position of the active area of the membrane electrode through a customized tooling, the EPDM is completely vulcanized to complete the bonding of the single cell.

[0045] The above is only an illustration of the preferred embodiments of the present invention. The above technical features can be arbitrarily combined to form multiple embodiment schemes of the present invention.

[0046] The present invention has been described exemplarily above in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as various non-substantive improvements are made by adopting the concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A fuel cell single cell structure includes an anode plate, a membrane electrode, and a cathode plate that are sequentially stacked. An anode sealing structure is provided between the anode plate and the membrane electrode, and a cathode sealing structure is provided between the membrane electrode and the cathode plate. It is characterized in that: Both the anode sealing structure and the cathode sealing structure are integral sealing rubber strip structures formed by semi-vulcanized injection molding. The anode plate, the membrane electrode, and the cathode plate form an integral single cell unit through the anode sealing structure and the cathode sealing structure, and an edge encapsulation for overall sealing is provided at the edge of the single cell unit.

2. The fuel cell single cell structure according to claim 1, characterized in that: A water field b surface is provided on the front surface of the anode plate of the single cell unit, and a water field a surface is provided on the back surface of the cathode plate of the single cell unit. Water cavities are formed between the two water field surfaces of adjacent single cell units, and a water field sealing rubber strip is provided at the edge of the water cavity.

3. The fuel cell single cell structure according to claim 1, characterized in that: A hydrogen cavity inlet is provided at one end of the anode plate, and a hydrogen cavity outlet is provided at the other end. The anode plate and the membrane electrode cooperate to form a hydrogen field, and the anode sealing structure is an integral sealing rubber strip structure corresponding to the hydrogen cavity inlet, the hydrogen cavity outlet, and the edge of the hydrogen field.

4. The fuel cell single cell structure according to claim 1, wherein: An air cavity inlet is provided at one end of the cathode plate, and an air cavity outlet is provided at the other end. The cathode plate and the membrane electrode cooperate to form an air field, and the cathode sealing structure is an integral sealing rubber strip structure corresponding to the air cavity inlet, the air cavity outlet, and the edge of the air field.

5. The fuel cell single cell structure according to claim 2, characterized in that: Sealing grooves are provided on the front surface of the anode plate and the back surface of the cathode plate corresponding to the water field sealing rubber strip.

6. The fuel cell single cell structure according to claim 3 or 4, characterized in that: The integral sealing rubber strip structure is an integral frame-shaped sealing strip.

7. The fuel cell single cell structure according to claim 5, characterized in that: The water field sealing rubber strip and the sealing groove are sealed by crimping.

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