Fuel cell bipolar plate assembly positioning point structure

Abstract

The application relates to the field of fuel cell technology and discloses a fuel cell bipolar plate assembly positioning point structure, which comprises a membrane electrode and a bipolar plate, the membrane electrode has a flange beyond the edge of the bipolar plate, a plurality of positioning holes are arranged on the flange, the positioning holes have hole bottom sections which do not exceed the edge of the bipolar plate, and the side walls of the positioning rods contact and position the bipolar plate. The flange can avoid the contact short circuit caused by the flush edges of the membrane electrode and the bipolar plate, the positioning rods pass through the positioning holes in the direction perpendicular to the membrane electrode to position the membrane electrode, meanwhile, since the hole bottom sections of the positioning holes do not exceed the edge of the bipolar plate, the positioning rods can approach the bipolar plate in the positioning holes, so that the side walls of the positioning rods contact the edge of the bipolar plate to position the bipolar plate, the misplacement between the membrane electrode and the bipolar plate during the assembly of the fuel cell stack is prevented, meanwhile, the arrangement of the positioning holes can avoid the pressing of the positioning rods on the flange of the membrane electrode, and the edges of the membrane electrode and the bipolar plate are prevented from being damaged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell, in particular to a fuel cell bipolar plate assembly positioning point structure. BACKGROUND

[0002] Fuel cell (PEMFC) is a kind of power generation device that converts chemical energy in fuel into electric energy through chemical reaction, and fuel cell has the advantages of high power density, high conversion rate, low environmental pollution, etc. In actual application, when the total power demand is greater than the output of a single cell, a fuel cell stack needs to be stacked by multiple bipolar plates and membrane electrodes, and end plates and fasteners are used for clamping and fixing at both ends.

[0003] In the process of stacking multiple bipolar plates and membrane electrodes and applying pressure to assemble a fuel cell stack, the stacked bipolar plates, membrane electrodes and other components are prone to misalignment, resulting in uneven edges of the assembled fuel cell stack, which not only affects the appearance, but also may affect the performance and service life of the stack. Adding a positioning device can alleviate this problem. The positioning structure used for fuel cell stack assembly at present mostly opens holes in the vertical direction of the membrane electrode and the bipolar plate to place the positioning rod, and then the positioning rod is extracted from the fuel cell stack after the fuel cell stack is assembled.

[0004] The existing positioning structure that opens holes in the vertical direction of the membrane electrode and the bipolar plate is suitable for the mode that the edges of the membrane electrode are flush with the edges of the bipolar plate. For graphite bipolar plates, burrs that may exist at the edges of the graphite bipolar plates on both sides of the membrane electrode can easily cause short circuit of the cell, thereby affecting the performance and safety of the cell. If the mode that the edges of the membrane electrode are flush with the edges of the bipolar plate is not adopted, but the mode that the edges of the membrane electrode slightly protrude outward by a certain distance from the edges of the bipolar plate is adopted, when the positioning rod is used, since the positioning rod needs to be in contact with the edges of the bipolar plate, the positioning rod will extrude the part of the edge frame of the membrane electrode that protrudes outward from the edges of the bipolar plate, which is easy to cause damage to the edges of the bipolar plate and the membrane electrode, and adversely affect the performance and safety of the fuel cell. SUMMARY

[0005] The purpose of the present application is to provide a fuel cell bipolar plate assembly positioning point structure to solve the problem that when the positioning rod is used for positioning in the prior art, the positioning rod extrudes the part of the edge frame of the membrane electrode that protrudes outward from the edges of the bipolar plate, causing damage to the edges of the bipolar plate and the membrane electrode.

[0006] In order to achieve the above object, the application provides a fuel cell bipolar plate assembly positioning point structure, comprising a membrane electrode and bipolar plates arranged on both sides of the membrane electrode, the membrane electrode and the bipolar plates are arranged in layers, the membrane electrode has a flange beyond the edge of the bipolar plate, a plurality of positioning holes for positioning rods to pass through are arranged on the flange, the positioning holes have a hole bottom section not beyond the edge of the bipolar plate, and the side wall of the positioning rod contacts the bipolar plate for positioning.

[0007] Preferably, a notch for avoiding the membrane electrode is arranged on the side of the bipolar plate close to the positioning hole.

[0008] Preferably, a chamfer is arranged on the end face of the bipolar plate, and the chamfer forms the notch.

[0009] Preferably, the side of the bipolar plate away from the positioning hole is also arranged with the notch, and the chamfers on both sides of the bipolar plate are arranged symmetrically.

[0010] Preferably, the edge of the bipolar plate is flush with the hole bottom section in the direction perpendicular to the membrane electrode.

[0011] Preferably, the positioning hole is a rectangular hole, and the hole bottom section is a straight section of the rectangular hole bottom.

[0012] Preferably, the membrane electrode and the bipolar plate are both rectangular structures, there are four positioning holes in total, and each side of the membrane electrode is arranged with the positioning hole.

[0013] Preferably, the positioning holes on the opposite sides of the membrane electrode are arranged in central symmetry on the membrane electrode.

[0014] Compared with the prior art, the fuel cell bipolar plate assembly positioning point structure of the embodiment of the application has the beneficial effects that: the membrane electrode has a flange beyond the edge of the bipolar plate, which can avoid the contact short circuit caused by the flush of the edges of the membrane electrode and the bipolar plate, positioning holes are arranged on the flange, when the fuel cell stack is positioned by using the positioning rods, the positioning rods pass through the positioning holes in the direction perpendicular to the membrane electrode to position the membrane electrode, meanwhile, since the hole bottom section of the positioning hole does not exceed the edge of the bipolar plate, the positioning rod can approach the bipolar plate in the positioning hole, so that the side wall of the positioning rod contacts the edge of the bipolar plate to position the bipolar plate, which prevents the mispositioning between the membrane electrode and the bipolar plate during the assembly of the fuel cell stack, meanwhile, the arrangement of the positioning hole can avoid the pressing of the flange of the membrane electrode by the positioning rod, which prevents the damage of the edges of the membrane electrode and the bipolar plate, and ensures the performance and safety of the fuel cell. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a structural schematic diagram of the fuel cell bipolar plate assembly positioning point structure of the application;

[0016] Figure 2 yes Figure 1 A cross-sectional schematic diagram of the bipolar plate assembly positioning point structure of a fuel cell.

[0017] In the figure, 1 is the membrane electrode; 2 is the first bipolar plate; 3 is the second bipolar plate; 4 is the flange; 5 is the positioning hole; and 6 is the notch. Detailed Implementation

[0018] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0019] A preferred embodiment of the fuel cell bipolar plate assembly positioning point structure of the present invention, such as... Figure 1 and Figure 2 As shown, the bipolar plate assembly and positioning structure of this fuel cell includes a membrane electrode 1 (MEA) and bipolar plates. The MEA and bipolar plates are stacked and arranged on both sides of the MEA. There are two bipolar plates in total, defined as a first bipolar plate 2 and a second bipolar plate 3. One of the first bipolar plate 2 and the second bipolar plate 3 is the anode plate of the fuel cell, and the other is the cathode plate of the fuel cell. The MEA, anode plate, and cathode plate form a single cell, and multiple single-node stacks form a fuel cell stack.

[0020] The size of the membrane electrode 1 is larger than the size of the first bipolar plate 2 and the second bipolar plate 3, so that the membrane electrode 1 has a flange 4 that extends beyond the edge of the bipolar plate. After the flange 4 extends beyond the edge of the bipolar plate, it will not come into contact with any burrs that may exist on the edge of the bipolar plate and cause a short circuit. That is, it avoids the short circuit caused by the edge of the membrane electrode 1 being flush with the edge of the bipolar plate in the prior art.

[0021] The flange 4 is provided with several positioning holes 5. The positioning holes 5 allow the positioning rod to pass through the flange 4 and position the membrane electrode 1, the first bipolar plate 2, and the second bipolar plate 3. When positioning the fuel cell stack using the positioning rod, the positioning rod passes through the positioning holes 5 in a direction perpendicular to the membrane electrode 1. The cooperation between the positioning rod and the positioning holes 5 is used to externally position the membrane electrode 1, ensuring the consistency of the stack assembly.

[0022] The positioning hole 5 has a bottom section that does not extend beyond the edge of the bipolar plate. This bottom section allows the sidewall of the positioning rod to contact and position the bipolar plate. Because the bottom section of the positioning hole 5 does not extend beyond the edge of the bipolar plate, the positioning rod can move closer to the bipolar plate within the positioning hole 5, allowing its sidewall to contact the edge of the bipolar plate and thus positioning the bipolar plate. This prevents misalignment between the membrane electrode 1 and the bipolar plate during fuel cell stack assembly. Simultaneously, the arrangement of the positioning hole 5 avoids the positioning rod pressing against the flange 4 of the membrane electrode 1, preventing damage to the edges of the membrane electrode 1 and the bipolar plate, and ensuring fuel cell performance and operational safety.

[0023] Preferably, the side of the bipolar plate close to the positioning hole 5 is provided with a notch 6 for avoiding the membrane electrode 1.

[0024] When the membrane electrode 1, the first bipolar plate 2 and the second bipolar plate 3 are assembled and compressed, bending occurs between the membrane electrode 1 and the two bipolar plates, and the notch 6 can avoid the membrane electrode 1 from contacting the first bipolar plate 2 and the second bipolar plate 3 on both sides to cause short circuit.

[0025] Preferably, the end face of the bipolar plate is provided with a chamfer, and the chamfer forms the notch 6.

[0026] The notch 6 is formed by the chamfer, that is, the cross section of the notch 6 is triangular structure, and the chamfer is simple in processing mode, which can simplify the forming mode of the notch 6. In other embodiments, the notch 6 can also be L-shaped or U-shaped structure.

[0027] Preferably, the side of the bipolar plate away from the positioning hole 5 is also provided with a notch 6, and the chamfers on both sides of the bipolar plate are symmetrically arranged.

[0028] The chamfers on both sides of the bipolar plate are symmetrically arranged, that is, the chamfers are symmetrically arranged on both sides of the first bipolar plate 2 and the second bipolar plate 3. The symmetric arrangement of the chamfers makes the first bipolar plate 2 and the second bipolar plate 3 have a symmetric structure respectively, and the two faces of the first bipolar plate 2 or the second bipolar plate 3 can be arranged close to the membrane electrode 1, which simplifies the installation mode of the bipolar plate.

[0029] Preferably, the edge of the bipolar plate is flush with the bottom section of the hole in the direction perpendicular to the membrane electrode 1.

[0030] The edge of the bipolar plate is flush with the bottom section of the hole, that is, the innermost side of the positioning hole 5 is flush with the bipolar plate. When the positioning rod passes through the positioning hole 5 for positioning, the side wall of the positioning rod is in the same plane with the edge of the bipolar plate and the bottom section of the hole of the membrane electrode 1, and the side wall of the positioning rod is used for external positioning of the bipolar plate and the membrane electrode 1 to prevent misalignment between the membrane electrode 1 and the bipolar plate.

[0031] In other embodiments, the inner side of the bottom section of the hole can also be located inside the edge of the bipolar plate, and at this time, the positioning rod can have a conical surface structure or a stepped structure to ensure that the side wall of the positioning rod externally positions the membrane electrode 1 and the bipolar plate.

[0032] Preferably, the positioning hole 5 is a rectangular hole, and the bottom section of the hole is a straight line section of the bottom of the rectangular hole.

[0033] The rectangular hole has a simple structure, and the bottom section of the hole is a straight line section, which increases the contact area with the side wall of the positioning rod, and at the same time, the straight line section is used to prevent the positioning rod from being inclined with the membrane electrode 1, which is beneficial to prevent misalignment between the membrane electrode 1 and the bipolar plate during assembly.

[0034] In other embodiments, the positioning hole 5 can also be a circular hole, which is tangent to the edge of the bipolar plate, and the bottom section of the hole is formed near the edge of the bipolar plate side.

[0035] Preferably, the membrane electrode 1 and the bipolar plate are both rectangular structures, and the positioning hole 5 is four in total, and is arranged on each side of the membrane electrode 1.

[0036] The rectangular membrane electrode 1 and the bipolar plate are general structures, which are convenient for installation of the fuel cell stack after assembly. The four positioning holes 5 are arranged on the four sides of the membrane electrode 1, and simultaneously position the four sides of the membrane electrode 1, the first bipolar plate 2 and the second bipolar plate 3, thereby preventing mispositioning.

[0037] In other embodiments, the membrane electrode 1 and the bipolar plate can also have other structures, and the number of the positioning hole 5 can be three, five, six, etc.

[0038] Preferably, the positioning holes 5 on the opposite sides of the membrane electrode 1 are arranged in a central symmetry on the membrane electrode 1.

[0039] The positioning holes 5 on the opposite sides of the membrane electrode 1 are arranged in a central symmetry, and the positioning direction of the positioning rod to the membrane electrode 1 and the bipolar plate is staggered, thereby positioning the membrane electrode 1 and the bipolar plate in multiple directions, which is beneficial to prevent mispositioning between the membrane electrode 1 and the bipolar plate during assembly.

[0040] In summary, the embodiment of the present application provides a fuel cell bipolar plate assembly positioning point structure. The membrane electrode has a flange that exceeds the edge of the bipolar plate, which can avoid contact short circuit caused by the edge of the membrane electrode being flush with the edge of the bipolar plate. The positioning hole is arranged on the flange. When the positioning rod is used to position the fuel cell stack, the positioning rod passes through the positioning hole in a direction perpendicular to the membrane electrode to position the membrane electrode. Since the bottom section of the positioning hole does not exceed the edge of the bipolar plate, the positioning rod can approach the bipolar plate in the positioning hole, so that the side wall of the positioning rod contacts the edge of the bipolar plate to position the bipolar plate, thereby preventing mispositioning between the membrane electrode and the bipolar plate during assembly of the fuel cell stack. Meanwhile, the arrangement of the positioning hole can avoid the positioning rod pressing the flange of the membrane electrode, thereby preventing damage to the edge of the membrane electrode and the bipolar plate, and ensuring the performance and safety of the fuel cell.

[0041] The above only describes the preferred embodiments of the present application. It should be noted that those skilled in the art can make several improvements and replacements without departing from the technical principles of the present application, and these improvements and replacements should also be considered as the protection scope of the present application.

Claims

1. A fuel cell bipolar plate assembly location point structure, characterized by, The membrane electrode and the bipolar plate are laminated, the membrane electrode has a flange beyond the edge of the bipolar plate, a plurality of positioning holes for positioning rods to pass through are arranged on the flange, the positioning holes have hole bottom sections which do not exceed the edge of the bipolar plate, and the side walls of the positioning rods contact the bipolar plate.

2. The fuel cell bipolar plate assembly land structure of claim 1, wherein, The side of the bipolar plate close to the positioning holes is provided with a notch for avoiding the membrane electrode.

3. The fuel cell bipolar plate assembly locator feature of claim 2, wherein, The end surface of the bipolar plate is provided with a bevel, and the bevel forms the notch.

4. The fuel cell bipolar plate assembly locator feature of claim 3, wherein, The side of the bipolar plate away from the positioning holes is also provided with the notch, and the bevels on the two sides of the bipolar plate are symmetrically arranged.

5. The fuel cell bipolar plate assembly locator feature of any one of claims 1-4, wherein, The edge of the bipolar plate is flush with the hole bottom section in the direction perpendicular to the membrane electrode.

6. The fuel cell bipolar plate assembly land structure of any one of claims 1-4, wherein, The positioning hole is a rectangular hole, and the hole bottom section is a straight section of the rectangular hole bottom.

7. The fuel cell bipolar plate assembly locator feature of any one of claims 1-4, wherein, The membrane electrode and the bipolar plate are both rectangular structures, there are four positioning holes in total, and each side of the membrane electrode is provided with the positioning holes.

8. The fuel cell bipolar plate assembly locator feature of claim 7, wherein, The positioning holes on the opposite sides of the membrane electrode are arranged in a central symmetry on the membrane electrode.

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