Fuel cell membrane electrode sealing structure

Abstract

The utility model discloses a sealing structure for a membrane electrode of a fuel cell, belongs to the field of fuel cells, and solves the problem in the prior art that a frame is easy to slip in an electric pile assembling process, so that the positioning error between the frame and a pole plate assembly is caused. In the application, a membrane electrode supporting frame is provided with a cathode surface and an anode surface, a cathode surface anti-skid groove is constructed on the cathode surface of the membrane electrode supporting frame, and an anode surface anti-skid groove is constructed on the anode surface of the membrane electrode supporting frame; the cathode surface anti-skid groove is annularly arranged along the length extension direction of the cathode surface of the membrane electrode support frame, and the anode surface anti-skid groove is annularly arranged along the length extension direction of the anode surface of the membrane electrode support frame; and the cathode surface anti-skid groove and the anode surface anti-skid groove are arranged in a mirror symmetry manner relative to the membrane electrode assembly. According to the membrane electrode sealing structure of the fuel cell, the problem of poor consistency of an electric pile caused by non-uniform deformation of a sealing element is solved, and meanwhile, the transverse slippage of the membrane electrode and the bipolar plate in the assembly process is improved.

Description

Technical Field

[0001] The utility model relates to a fuel cell membrane electrode sealing structure, belonging to the field of tires. Background Art

[0002] The proton exchange membrane fuel cell (PEMFC) is currently the fuel cell with the largest development scale. The constituent units of PEMFC include bipolar plates, membrane electrode assemblies and sealing structural parts such as silicone rubber. The fuel cell uses sealing structural parts to achieve the isolation and sealing of the hydrogen, air and coolant three cavities, prevent the leakage of reaction gases and coolant from the three cavities and external leakage, and keep the internal environments of multiple cavities of the stack independent. The failure of the seal, the breakage of the plate and the breakage of the membrane will all cause the seal failure of the stack, affecting the safety, performance and life of the entire fuel cell stack. Therefore, the sealing structural part is one of the most critical assembly structures in PEMFC.

[0003] There are many structural forms of the sealing assembly, including MEA integrated seal, bipolar plate integrated seal, independent seal and composite structure seal. The MEA integrated seal integrates the seal at the edge of the MEA to achieve a seven-in-one integrated seal structure, usually by injection molding. The bipolar plate integrated seal, similar to the MEA, uses the injection molding method to directly inject the sealant line into the seal groove of the plate to achieve an integrated seal structure of the sealant line and the plate. The independent seal structure uses methods such as injection molding and compression molding to manufacture independent seals. During the stack assembly process, the independent seals are matched with the plates or MEA, and the sealing effect is achieved by means of compression deformation. The composite seal structure uses a combined sealing method of any two of the above three structures. At present, the bipolar plate integrated seal is the most widely used sealing method. Its characteristic is to improve the assembly efficiency, usually by means of dispensing or bonding independent seals on the plate surface. However, in order to achieve the consistent force on multiple stack surfaces, this sealing method has very high matching accuracy requirements for the bipolar plate and MEA, and extremely high requirements for the stack pressing process. The main disadvantages include

[0004] The magnitude and planar distribution uniformity of the internal assembly force of the stack affect the deformation amount of the sealing structure, resulting in uneven pressure on the MEA, reducing the consistency of the output performance of multiple stack sections, and even causing local overpressure and membrane electrode failure due to loss of effectiveness.

[0005] The plastic material with low hardness and thin thickness of the MEA frame is prone to MEA surface slip during the stack assembly process, resulting in positioning errors with the plate assembly.

[0006] Therefore, in combination with the bipolar plate integrated seal structure, the design of the MEA edge seal structure needs to be improved urgently. Summary of the Utility Model

[0007] The present utility model provides a fuel cell membrane electrode sealing structure, which solves the problem of poor stack consistency caused by uneven deformation of the seal, and at the same time improves the lateral slip of the membrane electrode and the bipolar plate during the assembly process.

[0008] The technical solution adopted by the present utility model is a fuel cell membrane electrode sealing structure, including a membrane electrode assembly and a membrane electrode support frame; the membrane electrode assembly is installed within the frame of the membrane electrode support frame;

[0009] The membrane electrode support frame has a cathode surface and an anode surface. A cathode surface anti-slip groove is constructed on the cathode surface of the membrane electrode support frame, and an anode surface anti-slip groove is constructed on the anode surface of the membrane electrode support frame;

[0010] The cathode surface anti-slip groove is arranged in a ring along the length extension direction of the cathode surface of the membrane electrode support frame, and the anode surface anti-slip groove is arranged in a ring along the length extension direction of the anode surface of the membrane electrode support frame;

[0011] The cathode surface anti-slip groove and the anode surface anti-slip groove are arranged in a mirror symmetry type with respect to the membrane electrode assembly.

[0012] Optimally, in the above fuel cell membrane electrode sealing structure, one surface of the membrane electrode assembly is the membrane electrode anode discharge area, and the other surface of the membrane electrode assembly is the membrane electrode cathode discharge area; the cathode surface and the anode surface of the membrane electrode support frame are respectively matched with the membrane electrode cathode discharge area and the membrane electrode anode discharge area; there is a proton membrane between the membrane electrode anode discharge area and the membrane electrode cathode discharge area;

[0013] The membrane electrode assembly and the membrane electrode support frame are bonded.

[0014] Optimally, in the above fuel cell membrane electrode sealing structure, the membrane electrode support frame is integrally formed by polyethylene naphthalate (PEN), polyethylene terephthalate (PET) or polyimide (PI).

[0015] Optimally, in the above fuel cell membrane electrode sealing structure, the radial cross-section of the cathode surface anti-slip groove and the anode surface anti-slip groove is one of a rectangle, an isosceles trapezoid, a semi-circular arc, a composite configuration of two of them, or a composite configuration of three of them.

[0016] Optimally, in the above fuel cell membrane electrode sealing structure, the depth of the cathode surface anti-slip groove and the anode surface anti-slip groove is 0.02 - 0.2 mm, and the width is 3 mm.

[0017] Optimally, in the above fuel cell membrane electrode sealing structure, the distance between the inner bottom end surface of the cathode surface anti-slip groove and the inner bottom end surface of the anode surface anti-slip groove is 0.08 - 0.5 mm.

[0018] Optimized, in the above fuel cell membrane electrode sealing structure, the anode discharge area of the membrane electrode is 0.2 mm higher than the anode surface of the membrane electrode support frame, and the cathode discharge area of the membrane electrode is 0.2 mm higher than the cathode surface of the membrane electrode support frame.

[0019] The advantages of this application are as follows:

[0020] During the stack assembly process, the MEA is under uneven pressure. In this case, through the equal-height limiting effect of the membrane electrode support frame, the problem of poor consistency of multiple stack sections is solved; the anti-slip grooves on the MEA support frame effectively prevent the lateral slip of the MEA after being pressurized.

[0021] In the technical solution of this application, within the cathode surface and anode surface areas of the membrane electrode support frame, cathode surface anti-slip grooves and anode surface anti-slip grooves are provided as adhesive line anti-slip grooves. During the stack pressing process, due to the action of the cathode surface anti-slip grooves and anode surface anti-slip grooves, the cavity formed by the adhesive line between the membrane electrode and the plate sealing groove restricts the lateral movement orientation of the membrane electrode relative to the plate, effectively reducing the misalignment between the plate and the membrane electrode and achieving higher-precision longitudinal positioning.

[0022] When multiple fuel cell membrane electrodes are stacked, the force is uniform, and the consistency of the contact resistance of multiple fuel cell membrane electrodes is improved, thereby improving the consistency of the output performance.

[0023] The compression thickness of the sealing frame is the same as the compression thickness of the effective discharge area of the membrane electrode. Through the equal-height limiting effect of the rigid sealing frame, the effective discharge area of the membrane electrode is prevented from being damaged due to uneven pressure. Description of the Drawings

[0024] Figure 1 is a structural schematic diagram of this application;

[0025] Figure 2 is a partial cross-sectional view of this application. Detailed Embodiments

[0026] The following further elaborates on the technical features of the present utility model in conjunction with the drawings and specific embodiments.

[0027] As shown in the figure, the present utility model is a fuel cell membrane electrode sealing structure, including a membrane electrode assembly, a membrane electrode support frame 2, a membrane electrode three-chamber through hole 11, a membrane electrode cathode discharge area 12, a membrane electrode anode discharge area 13, a proton membrane 14, a cathode surface anti-slip groove 21, and an anode surface anti-slip groove 22.

[0028] Among them, the membrane electrode support frame 2 is adapted to the membrane electrode assembly and is made of a material with insulation, high hardness, and small compression deformation rate. The membrane electrode support frame 2 can be integrally formed using materials such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET), and polyimide (PI).

[0029] In this embodiment, the membrane electrode support frame 2 is constructed as a rectangular frame, and the thickness of the membrane electrode support frame 2 should be the same as the thickness after installation and compression of the effective discharge area of the membrane electrode assembly.

[0030] The membrane electrode assembly includes a membrane electrode cathode discharge area 12, a membrane electrode anode discharge area 13, and a proton membrane 14. The proton membrane 14 is sandwiched between the membrane electrode cathode discharge area 12 and the membrane electrode anode discharge area 13. The membrane electrode assembly is installed in the frame of the membrane electrode support frame 2 and is relatively fixed to the membrane electrode support frame 2 by bonding or other means.

[0031] The membrane electrode support frame 2 has a cathode surface and an anode surface. The cathode surface and the anode surface of the membrane electrode support frame 2 are respectively arranged in cooperation with the membrane electrode cathode discharge area 12 and the membrane electrode anode discharge area 13. The membrane electrode support frame 2 is provided with an outer positioning edge or an inner positioning hole.

[0032] As shown in the figure, a cathode surface anti-slip groove 21 is constructed on the cathode surface of the membrane electrode support frame 2, and an anode surface anti-slip groove 22 is constructed on the anode surface of the membrane electrode support frame 2. The cathode surface anti-slip groove 21 is arranged in a ring shape along the length extension direction of the cathode surface of the membrane electrode support frame 2, and the anode surface anti-slip groove 22 is arranged in a ring shape along the length extension direction of the anode surface of the membrane electrode support frame 2.

[0033] The anode surface anti-slip groove 22 and the cathode surface anti-slip groove 21 have the same shape, and the anode surface anti-slip groove 22 and the cathode surface anti-slip groove 21 are arranged in a mirror-symmetrical manner on the anode surface and the cathode surface of the membrane electrode support frame 2.

[0034] As shown in the figure, the membrane electrode support frame 2 has a membrane electrode three-chamber through hole 11, and the membrane electrode three-chamber through hole 11 penetrates through the membrane electrode support frame 2.

[0035] The radial cross-section of the anode surface anti-slip groove 22 and the cathode surface anti-slip groove 21 is set to be rectangular, isosceles trapezoidal, semi-circular arc-shaped, or the anode surface anti-slip groove 22 and the cathode surface anti-slip groove 21 can also be a composite configuration of shapes such as rectangular, isosceles trapezoidal, semi-circular arc-shaped, etc., and their shapes are selected according to actual needs.

[0036] The depths of the anode surface anti-slip groove 22 and the cathode surface anti-slip groove 21 are set to be 0.02 - 0.2 mm, the width is 3 mm, and the distance between the inner bottom end surface of the cathode surface anti-slip groove 21 and the inner bottom end surface of the anode surface anti-slip groove 22 is 0.08 - 0.5 mm.

[0037] In the non-compressed state, the anode discharge area 13 of the membrane electrode is 0.05 - 0.2 mm higher than the anode surface of the membrane electrode support frame 2, and the cathode discharge area 12 of the membrane electrode is 0.05 - 0.2 mm higher than the cathode surface of the membrane electrode support frame 2. After compression, the anode discharge area 13 of the membrane electrode is flush with the anode surface of the membrane electrode support frame 2, and the cathode discharge area 12 of the membrane electrode is flush with the cathode surface of the membrane electrode support frame 2.

[0038] The anti-slip grooves 22 on the anode surface and the anti-slip grooves 21 on the cathode surface are used to place the sealant line. The type of the sealant line can be selected as long as it matches the shape of the radial cross-section of the anti-slip grooves 22 on the anode surface and the anti-slip grooves 21 on the cathode surface.

[0039] Certainly, the above description is not a limitation to the present utility model, and the present utility model is not limited to the above examples. Any changes, modifications, additions or substitutions made by those of ordinary skill in the art within the scope of the essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A fuel cell membrane electrode sealing structure, comprising a membrane electrode assembly and a membrane electrode support frame (2); the membrane electrode assembly is installed within the frame of the membrane electrode support frame (2); characterized in that : The membrane electrode support frame (2) has a cathode surface and an anode surface. Cathode surface anti-slip grooves (21) are formed on the cathode surface of the membrane electrode support frame (2), and anode surface anti-slip grooves (22) are formed on the anode surface of the membrane electrode support frame (2). The cathode surface anti-slip grooves (21) are arranged in a ring along the length extension direction of the cathode surface of the membrane electrode support frame (2), and the anode surface anti-slip grooves (22) are arranged in a ring along the length extension direction of the anode surface of the membrane electrode support frame (2). The cathode surface anti-slip grooves (21) and the anode surface anti-slip grooves (22) are arranged in a mirror symmetry with respect to the membrane electrode assembly.

2. The fuel cell membrane electrode sealing structure according to claim 1, wherein: One surface of the membrane electrode assembly is the membrane electrode anode discharge area (13), and the other surface of the membrane electrode assembly is the membrane electrode cathode discharge area (12); the cathode surface and the anode surface of the membrane electrode support frame (2) are respectively matched with the membrane electrode cathode discharge area (12) and the membrane electrode anode discharge area (13); there is a proton membrane (14) between the membrane electrode anode discharge area (13) and the membrane electrode cathode discharge area (12). The membrane electrode assembly and the membrane electrode support frame (2) are bonded.

3. The fuel cell membrane electrode sealing structure according to claim 1, characterized in that: The membrane electrode support frame (2) is integrally formed by polyethylene naphthalate PEN, polyethylene terephthalate PET or polyimide PI.

4. The fuel cell membrane electrode sealing structure according to claim 1, wherein: The radial cross-sections of the cathode surface anti-slip grooves (21) and the anode surface anti-slip grooves (22) are one of a rectangle, an isosceles trapezoid, a semi-circular arc, a composite configuration of two of them, or a composite configuration of three of them.

5. The fuel cell membrane electrode sealing structure according to claim 1, wherein: The depths of the cathode surface anti-slip grooves (21) and the anode surface anti-slip grooves (22) are 0.02 - 0.2 mm, and the widths are 3 mm.

6. The fuel cell membrane electrode sealing structure according to claim 1, wherein: The distance between the inner bottom end surface of the cathode surface anti-slip grooves (21) and the inner bottom end surface of the anode surface anti-slip grooves (22) is 0.08 - 0.5 mm.

7. The fuel cell membrane electrode sealing structure according to claim 2, characterized in that: The membrane electrode anode discharge area (13) is 0.2 mm higher than the anode surface of the membrane electrode support frame (2), and the membrane electrode cathode discharge area (12) is 0.2 mm higher than the cathode surface of the membrane electrode support frame (2).

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