Metal bipolar plate anti-pressing structure, metal bipolar plate and electric pile

Abstract

The utility model relates to a kind of metal bipolar plate pressure-preventing structure, metal bipolar plate and electric pile, the metal bipolar plate pressure-preventing structure is used to cooperate with the overbridge area of metal bipolar plate, the overbridge area has sealing groove;The metal bipolar plate pressure-preventing structure includes the compression-resisting plate similar to the sealing groove;The compression-resisting plate is set in the sealing groove, the thickness of the compression-resisting plate is less than the depth of the sealing groove;The number of the compression-resisting plate is provided with at least one.The at least one compression-resisting plate is fixed in the sealing groove by adhesive mode.The utility model can effectively solve the problem in the prior art that electric pile is collapsed under the action of larger packing force, forming irreversible wave-shaped deformation, and further leading to sealing failure, and can effectively avoid the damage to the performance of electric pile caused by sealing failure;Ensure that the whole assembly is stressed smoothly and consistently during the pressing process, improve assembly quality and reliability.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen fuel cell technology, and in particular to a metal bipolar plate pressure-resistant structure, a metal bipolar plate, and a fuel cell stack. Background Technology

[0002] A hydrogen fuel cell is a chemical power generation device that directly converts the chemical energy of hydrogen into electrical energy. Because fuel cells convert the Gibbs free energy portion of the fuel's chemical energy into electrical energy through an electrochemical reaction, they are not limited by the Carnot cycle effect, thus exhibiting a much higher energy conversion efficiency than internal combustion engines. Furthermore, since hydrogen fuel cells use hydrogen and air as fuel, they have no mechanical transmission components, produce no harmful gas emissions, and are noiseless. Therefore, from an energy and environmental perspective, hydrogen fuel cells have a broad development prospect. Currently, the structure of a fuel cell metal bipolar plate generally includes a flow field region, a distribution region, and gas-liquid inlet / outlet regions. The flow field region provides the reaction site for the fuel cell, the distribution region distributes the coolant and gas to ensure uniform distribution, and the gas-liquid inlet / outlet regions ensure normal and uniform flow of gas or liquid. Currently, the mainstream method for coolant and gas entry and exit in China is the traditional groove-turning method, where coolant and gas flow up and down within the inlet / outlet channel. This channel is the bridging region. In traditional fuel cell bipolar plate designs, the outer edge of the bridging region is usually equipped with an annular sealing component to achieve bidirectional isolation between the reactant gas and the coolant.

[0003] However, the drawback of the existing technology is that during the operation of the fuel cell stack, under the action of a large stacking force, the seals will gradually collapse the cavity in the bridge area, resulting in irreversible wave-shaped deformation, as shown in the attached diagram of the specification. Figure 1 as well as Figure 2 As shown, as the pressure on the seal in this area decreases and the compression gradually diminishes, the seal eventually fails. This failure of the seal can severely damage the function of the metal stack. Current solutions mostly mitigate this by reducing the size of the inlet and outlet in the bridge area. However, existing methods also introduce new drawbacks. As the pressure drop at the inlet and outlet increases, the flow resistance increases, which in turn affects the performance of the entire stack. Utility Model Content

[0004] Therefore, the technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a metal bipolar plate anti-pressure structure, a metal bipolar plate and a fuel cell stack, which can effectively avoid the damage to the performance of the fuel cell stack caused by the failure of the seal; and ensure that the entire component is subjected to stable and consistent force during the pressing process, thereby improving the assembly quality and reliability.

[0005] To solve the above technical problems, this utility model provides a metal bipolar plate anti-pressure structure that cooperates with the bridging area of ​​the metal bipolar plate, wherein the bridging area has a sealing groove; The metal bipolar plate pressure-resistant structure includes a pressure-resistant plate that is similar in shape to the sealing groove; the pressure-resistant plate is disposed in the sealing groove, and the thickness of the pressure-resistant plate is less than the depth of the sealing groove; the number of pressure-resistant plates is at least one.

[0006] In one embodiment of the present invention, at least one of the pressure-resistant plates is fixed to the sealing groove by adhesive bonding.

[0007] In one embodiment of this utility model, at least one of the pressure-resistant plates is fixed to the sealing groove by welding.

[0008] In one embodiment of this utility model, the sealing groove is further filled with sealant.

[0009] In one embodiment of this utility model, at least one of the pressure-resistant plates is made of stainless steel, titanium alloy and nickel-based alloy.

[0010] This utility model also provides a metal bipolar plate, comprising, ontology; A bridging area is provided within the main body; A gas-liquid inlet is located in the bridge area; A gas-liquid outlet is located in the bridge area; A sealing groove unit is formed in the bridge area, the sealing groove unit including at least one sealing groove; The metal bipolar plate pressure-resistant structure described above is disposed in the sealing groove unit.

[0011] In one embodiment of the present invention, the sealing groove unit includes an anode sealing groove, and the metal bipolar plate anti-pressure structure includes a first anti-pressure plate; the first anti-pressure plate is configured to match the anode sealing groove.

[0012] In one embodiment of the present invention, the sealing groove unit includes a cathode sealing groove, and the metal bipolar plate anti-pressure structure further includes a second anti-pressure plate, which is configured to match the cathode sealing groove.

[0013] In one embodiment of this utility model, the thickness of the pressure-resistant plate of the metal bipolar plate pressure-resistant structure is at least twice the thickness of the metal bipolar plate.

[0014] This invention also provides a fuel cell stack, including the metal bipolar plate described above.

[0015] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art: This utility model discloses a metal bipolar plate anti-pressure structure, comprising an anti-pressure plate adapted to the sealing groove of the metal bipolar plate's bridging area. The anti-pressure plate provides good support, offering localized rigid support and preventing structural crushing. Due to its higher strength and rigidity, the anti-pressure plate, after being assembled into the sealing groove, can directly withstand the pressing force from other structures. Furthermore, because the anti-pressure plate adopts a contoured structure consistent with the sealing groove, it ensures a tight fit between the anti-pressure plate and the sealing groove. Consequently, the force can be evenly transmitted to the supporting structure of the entire bridging area, avoiding stress concentration and significantly enhancing the anti-pressure resistance of the bridging area. The pressure-resistant plate effectively prevents the bridge from collapsing; it also evenly transmits and distributes the pressing force, improving the flatness of the seal. Because the pressure-resistant plate is a continuous planar structure, the concentrated load applied to it can be evenly distributed to the base area of ​​the entire sealing groove. This invention effectively solves the problem in the prior art where, under the action of a large stacking force, the seal collapses the cavity of the bridge area, forming irreversible wave-shaped deformation, which leads to seal failure. It also effectively avoids damage to the performance of the stack caused by seal failure. It ensures that the entire component is subjected to stable and consistent force during the pressing process, improving assembly quality and reliability. Attached Figure Description

[0016] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the collapse state (forming wave-shaped deformation) of the cavity in the bridge area in the prior art.

[0018] Figure 2 This is a schematic diagram of the bridge area cavity in the existing technology when it has not collapsed.

[0019] Figure 3 This is a schematic diagram of the installation process of the metal bipolar plate assembly pressure plate according to a preferred embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the specific structure of the metal bipolar plate of the preferred embodiment of this utility model when it is not equipped with a pressure-resistant plate.

[0021] Figure 5 This is a photograph of the actual object after the pressure-resistant plate of the preferred embodiment of this utility model is assembled with the metal bipolar plate.

[0022] Explanation of reference numerals in the instruction manual: 11. Bridge area; 111. Gas-liquid inlet; 112. Gas-liquid outlet; 113. Cathode sealing groove; 114. Anode sealing groove; 12. Pressure-resistant plate; 2. Body. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention. Example 1

[0024] Refer to Figure 3 , Figure 4 as well as Figure 5 As shown, this utility model discloses a metal bipolar plate anti-pressure structure, which cooperates with the bridging area 11 of the metal bipolar plate, and the bridging area 11 has a sealing groove.

[0025] The pressure-resistant structure includes a pressure-resistant plate 12 that is similar in shape to the sealing groove; the pressure-resistant plate 12 is disposed in the sealing groove, and the thickness of the pressure-resistant plate 12 is less than the depth of the sealing groove 11.

[0026] Therefore, it can be understood that the metal bipolar plate anti-pressure structure protected by this utility model includes an anti-pressure plate adapted to the sealing groove of the metal bipolar plate's bridging area. The anti-pressure plate can play a good supporting role, providing local rigid support and preventing structural crushing. Because the anti-pressure plate itself has higher strength and rigidity, it can directly withstand the pressing force from other structures after being assembled into the sealing groove. In addition, since the anti-pressure plate adopts a contoured structure consistent with the sealing groove structure, it ensures that the anti-pressure plate and the sealing groove fit perfectly, and the force can be evenly transmitted to the supporting structure of the entire bridging area, avoiding stress concentration, thereby significantly enhancing the anti-pressure resistance of the bridging area. This invention effectively prevents the bridge from collapsing under pressure; it also evenly transmits and distributes the pressing force, improving the flatness of the seal. Because the pressure plate is a continuous planar structure, the concentrated load applied to it can be evenly distributed to the base area of ​​the entire sealing groove. This invention effectively solves the problem in the prior art where, under a large stacking force, the seal collapses the cavity of the bridge area, forming irreversible wave-shaped deformation, leading to seal failure. It also effectively avoids damage to the performance of the stack caused by seal failure. It ensures that the entire component is subjected to stable and consistent force during the pressing process, improving assembly quality and reliability.

[0027] In a preferred embodiment, the pressure-resistant plate, which is cut to conform to the structure of the sealing groove, is fixed to the sealing groove by adhesive bonding or spot welding. Of course, in other embodiments, the pressure-resistant plate 12 can also be fixed to the sealing groove by other methods.

[0028] It should be noted that the sealing groove is also filled with sealant.

[0029] In one embodiment, the thickness of the pressure-resistant plate 12 is 0.05-0.3 mm, and the thickness of the pressure-resistant plate 12 is less than the depth of the sealing groove, so that when the pressure-resistant plate 12 is assembled into the sealing groove, the remaining space is sealed with sealant.

[0030] In detail, the hardness of the sealant is 10-80 degrees Shore A (used to uniformly transmit the pressing force during stacking to prevent the bridge from being crushed); the sealant's own strength is 1-20 MPa (to prevent its own structure from being damaged under high pressure); the sealant's compression deformation is less than 8% (to prevent permanent deformation and seal failure under high pressure); the sealant's temperature resistance range is -40℃ to 150℃.

[0031] The sealant can fill gaps and achieve sealing while providing a certain elastic deformation to compensate for minor unevenness; the pressure-resistant plate 12 bears most of the mechanical pressure, allowing the sealant to be compressed within its allowable compression range, thereby achieving the sealing function; improving process stability and product consistency; since the thickness of the pressure-resistant plate 12 is fixed, the volume of the remaining space formed after the pressure-resistant plate 12 is assembled into the sealing groove is also fixed, thereby ensuring product consistency and yield.

[0032] The materials of the pressure-resistant plate include stainless steel, titanium alloy and nickel-based alloy. Example 2

[0033] This utility model also discloses a metal bipolar plate, combined with Figures 3 to 5 The metal bipolar plate includes a body 2. The metal bipolar plate also includes a bridging region 11, which is disposed on the body 2; The metal bipolar plate also includes a gas-liquid inlet 111, which is disposed in the bridge area 11 and is used for gas and liquid to enter the metal bipolar plate. The metal bipolar plate also includes a gas-liquid outlet 112, which is disposed in the bridge area 11 and is used for discharging gas and liquid from the metal bipolar plate. The metal bipolar plate also includes a sealing groove unit formed in the bridge area 11; specifically, the sealing groove unit is formed on at least one side surface of the body 2.

[0034] The metal bipolar plate also includes at least one metal bipolar plate anti-pressure structure as described in Embodiment 1. The metal bipolar plate anti-pressure structure is disposed in the sealing groove unit and is configured to be adapted to the sealing groove unit.

[0035] Therefore, it can be seen that the metal bipolar plate with the aforementioned anti-pressure structure can solve the problem in the prior art where the seal collapses the cavity of the bridge area under the action of a large stacking force, resulting in irreversible wave-shaped deformation and thus sealing failure. It can also effectively avoid the damage to the performance of the stack caused by the failure of the seal. It ensures that the metal bipolar plate and other components are subjected to stable and consistent force during the pressing process, thus improving the assembly quality and reliability.

[0036] Preferably, the metal bipolar plate pressure-resistant structure includes two pressure-resistant plates 12.

[0037] Furthermore, the sealing groove unit includes a cathode sealing groove 113, wherein one of the pressure-resistant plates 12 is configured to match the cathode sealing groove 113 and is installed in the cathode sealing groove 113; Furthermore, the sealing groove unit includes an anode sealing groove 114, and another pressure-resistant plate 12 is configured to match the anode sealing groove 114 and is installed in the anode sealing groove 114.

[0038] As a preferred embodiment, the thickness of the compression plate 12 is at least twice the thickness of the metal bipolar plate to provide sufficient strength support (the plate thickness is ≤0.1mm, and it is prone to instability and deformation under pressure, such as wrinkling and buckling). The bending stiffness can theoretically be increased by 8 times, but in actual processing, it is affected by the interface bonding quality, boundary constraints and material properties, and the measured value is usually 70%-90% of the theoretical value.

[0039] Preferably, the thickness of the metal bipolar plate is generally 0.075-0.1 mm. Traditional sealing methods require stamping out a sealing groove, which is generally about 0.2-0.6 mm thick. Taking a 0.1 mm thick metal bipolar plate as an example, the thickness and width of the sealing groove in the bridging area are about 0.4 mm. Therefore, a pressure-resistant plate 12 with a thickness of 0.2 mm and a width of 0.35 mm (consistent with the shape of the sealing groove in the bridging area) is used and fixed by welding or bonding (adhesives include, but are not limited to, epoxy resin).

[0040] Furthermore, the introduction of the pressure-resistant plate 12 causes a stepped structure to form around the originally flat sealing groove. To solve the above problem, the metal bipolar plate can be sealed using a semi-adhesive method. A specific implementation method has been disclosed in Chinese Patent CN221708742U (An integrated assembly structure of a bipolar plate and a membrane electrode and a fuel cell stack). Additionally, sealant is evenly applied to the required locations within the sealing groove using a dispensing method, while the amount of sealant applied at the pressure-resistant plate 12 is appropriately reduced to prevent overflow. It should be noted that the sealant serves to seal, fill, resist pressure, and bond. Example 3

[0041] This utility model also discloses an electric stack, including an end plate, an insulating plate, a current collector, a membrane electrode, and a metal bipolar plate as described in Embodiment 2.

[0042] The membrane electrode and the bipolar plate are stacked to form a single cell structure, and the single cell structures are stacked to form a battery stack. The current collectors are respectively provided at both ends of the battery stack, and the end plates are disposed opposite to the outside of the current collectors. An insulating plate is provided between the end plates and the current collectors. The above structure is assembled by fastener assembly to form a battery stack.

[0043] In the description of this utility model, it should be understood that 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. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0044] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0045] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A metal bipolar plate pressure-resistant structure, characterized in that: The bridging area, which is compatible with the metal bipolar plate, has a sealing groove. The metal bipolar plate pressure-resistant structure includes a pressure-resistant plate that is similar in shape to the sealing groove; the pressure-resistant plate is disposed in the sealing groove, and the thickness of the pressure-resistant plate is less than the depth of the sealing groove; the number of pressure-resistant plates is at least one.

2. The metal bipolar plate pressure-resistant structure according to claim 1, characterized in that: At least one of the pressure-resistant plates is fixed to the sealing groove by adhesive.

3. The metal bipolar plate pressure-resistant structure according to claim 1, characterized in that: At least one of the pressure-resistant plates is fixed to the sealing groove by welding.

4. The metal bipolar plate pressure-resistant structure according to claim 1, characterized in that: The sealing groove is also filled with sealant.

5. The metal bipolar plate pressure-resistant structure according to claim 1, characterized in that: At least one of the pressure-resistant plates is made of stainless steel, titanium alloy, or nickel-based alloy.

6. A metal bipolar plate, characterized in that: include, ontology; A bridging area is provided within the main body; A gas-liquid inlet is located in the bridge area; A gas-liquid outlet is located in the bridge area; A sealing groove unit is formed in the bridge area, the sealing groove unit including at least one sealing groove; The metal bipolar plate pressure-resistant structure as described in any one of claims 1-5 is disposed in the sealing groove unit.

7. A metal bipolar plate according to claim 6, characterized in that: The sealing groove unit includes an anode sealing groove, and the metal bipolar plate anti-pressure structure includes a first anti-pressure plate; the first anti-pressure plate is configured to match the anode sealing groove.

8. A metal bipolar plate according to claim 7, characterized in that: The sealing groove unit includes a cathode sealing groove, and the metal bipolar plate anti-pressure structure also includes a second anti-pressure plate, which is configured to match the cathode sealing groove.

9. A metal bipolar plate according to claim 6, characterized in that: The thickness of the pressure-resistant plate of the metal bipolar plate pressure-resistant structure is at least twice the thickness of the metal bipolar plate.

10. A fuel cell stack, characterized in that: Includes the metal bipolar plate as described in any one of claims 6-9.

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