Membrane electrode frame assembly and pem electrolysis stack

Abstract

The application relates to the technical field of PEM electrolytic stacks, and discloses a membrane electrode frame assembly with a relatively compact membrane electrode assembly layer structure and a PEM electrolytic stack, which comprises a frame body (corresponding to 110 or 130) formed as an inner hollow structure, at least one limiting component (corresponding to 112, 113 or 132, 133) arranged at the inner edge of the frame body (corresponding to 110 or 130), and a through hole (corresponding to 115 or 135) capable of penetrating a screw rod and arranged in the limiting component (corresponding to 112, 113 or 132, 133).

Description

Technical Field

[0001] This invention relates to the field of PEM electrolyzer technology, and more specifically, to a membrane electrode frame assembly and a PEM electrolyzer. Background Technology

[0002] Layered membrane electrode assemblies are components used to generate hydrogen and oxygen in electrolytic reactors or water electrolysis systems. Typically, a membrane electrode assembly consists of a perfluorosulfonic acid ionomer membrane that allows hydrogen ions (protons) to pass through, and an anode and cathode stacked on opposite sides of the proton exchange membrane.

[0003] Currently, PEM electrolyzers are typically composed of multilayer (e.g., 30-50 layers) membrane electrode assemblies. Multiple tie rods are added to the end plates and periphery to lock the stacked membrane electrode assemblies, effectively reducing the gap between the current collector layer and the proton exchange membrane. However, during assembly and use, it was found that although adding tie rods reduces the bonding gap between the membrane electrodes, the efficiency of hydrogen electrolysis at the rated power cannot reach the design value. This indicates that when multiple current collector layers are stacked with the proton exchange membrane, there is bulging deformation in the frame and its internal current collector layer assemblies, leading to increased spacing and increased resistance of the current collector layer assemblies, resulting in less than ideal hydrogen electrolysis performance.

[0004] Therefore, ensuring the flatness of the proton multilayer current collector layer and the proton membrane during stacking to reduce the resistance of the membrane electrode assembly has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that, in the above-mentioned existing technology, the efficiency of hydrogen electrolysis under the specified power cannot reach the design value, indicating that when multiple current collector layers and proton membranes are stacked, the proton membrane has a bulging problem, which leads to an increase in its resistance and the performance of hydrogen electrolysis is not ideal. The present invention provides a membrane electrode frame assembly and a PEM electrolyzer with a relatively compact membrane electrode assembly stacking structure.

[0006] The technical solution adopted by this invention to solve its technical problem is: constructing a membrane electrode frame assembly, comprising:

[0007] The frame body is formed as a hollow structure, and at least one limiting component is provided on the inner edge of the frame body, and a through hole for a screw to pass through is provided in the limiting component.

[0008] In some embodiments, the defining component includes a first defining component and a second defining component that are intersecting and disposed together.

[0009] A through hole is provided at the intersection of the first limiting component and the second limiting component.

[0010] In some embodiments, the end faces of the first defining component and the second defining component are horizontally aligned with the end face of the frame body.

[0011] In some embodiments, water / gas channels are provided on one end face of the first limiting component and the second limiting component, respectively.

[0012] In some embodiments, the through hole extends upward along the end face of the first defining member or the second defining member.

[0013] In some embodiments, a first sealing rib is provided on both end faces of the through hole, and the first sealing rib has the same height as the second sealing rib on both end faces of the frame body.

[0014] In a second aspect, a PEM electrolyzer includes any of the membrane electrode frame assemblies described above and end plates disposed at both ends of the membrane electrode frame assembly.

[0015] In some embodiments, a first through hole corresponding to the through hole is provided on the end plate, and the first through hole and the through hole are arranged on the same axis.

[0016] In some embodiments, an anode, a titanium mesh, a proton exchange membrane, a felt, a cathode, and a conductive layer are stacked within the membrane electrode frame assembly, and a third through hole corresponding to the through hole is provided on the anode, the proton exchange membrane, the cathode, and the conductive layer.

[0017] In some embodiments, a diffusion layer assembly is provided within the frame body, and a step is provided on the bottom outer edge of the diffusion layer assembly that abuts against the frame body, the step being in contact with the lip of the inner edge of the frame body.

[0018] First sealing rib

[0019] The membrane electrode frame assembly of the present invention includes a frame body with a hollow structure. At least one limiting member is disposed on the inner edge of the frame body, and a through hole is formed within the limiting member for a screw to pass through. Compared with the prior art, by providing at least one limiting member within the frame body and a through hole within the limiting member, the end plate and the membrane electrode assembly are locked together during the stacking of the membrane electrode assembly by a screw located in the middle of the end plate and a screw on the outer edge. This improves the adhesion between the current collector layer, the proton exchange membrane, and the diffusion layer assembly, effectively solving the problem of proton membrane bulging when multiple current collector layers and proton membranes are stacked, thereby reducing the resistance of the membrane electrode and improving the efficiency of electrolysis in the electrolytic reactor. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0021] Figure 1 This is an exploded view of an embodiment of a PEM electrolytic reactor provided by the present invention;

[0022] Figure 2 This is a partial cross-sectional view of an embodiment of a PEM electrolytic reactor provided by the present invention;

[0023] Figure 3 This is a perspective view of an embodiment of the end plate provided by the present invention;

[0024] Figure 4 This is a perspective view of an embodiment of the membrane electrode frame assembly provided by the present invention;

[0025] Figure 5 This is a perspective view of another embodiment of the membrane electrode frame assembly provided by the present invention;

[0026] Figure 6 This is a perspective view of an embodiment of the diffusion layer component provided by the present invention;

[0027] Figure 7 This is a perspective view of another embodiment of the diffusion layer component provided by the present invention. Detailed Implementation

[0028] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0029] like Figure 1 As shown, in the first embodiment of the PEM electrolyzer of the present invention, the PEM electrolyzer includes at least a membrane electrode frame assembly, a current collector layer, a diffusion layer assembly 104, multiple sealing gasket layers 105, and a proton exchange membrane 106.

[0030] The frame body (corresponding to 110 or 130) is formed as a hollow structure (corresponding to 111 and 113), which is injection molded from PPSU material and can be square or round.

[0031] The current collector layer is stacked in front of the membrane electrode to conduct current between adjacent membrane electrodes.

[0032] A proton exchange membrane 106 is disposed between the sealing gasket layer 105, the diffusion layer assembly 104, and the frame body (corresponding to 110 or 130). Specifically, the proton exchange membrane 106 is disposed between the anode electrode and the cathode electrode. During electrolysis, pure water undergoes an electrolytic reaction at the anode electrode to form oxygen, electrons, and hydrogen ions (protons). Oxygen and some pure water flow back to the water storage component, while protons and water migrate through the proton exchange membrane 106 to the cathode side. Through the cathode catalytic layer and the cathode diffusion layer, hydrogen ions are formed into hydrogen gas at the cathode.

[0033] The diffusion layer assembly 104 includes an anode assembly and a cathode assembly. The anode assembly typically includes a titanium mesh, titanium felt, etc., and the cathode assembly typically includes a felt layer and a plate layer, such as felt cloth (e.g., carbon felt cloth or stainless steel felt) and stainless steel plate layer, etc.

[0034] Specifically, such as Figure 4 and Figure 5 As shown, the frame body (corresponding to 110 or 130) is formed as a hollow structure, serving as a defined space for the diffusion layer component 104 and the proton exchange membrane 106, so as to form a water flow field or a gas flow field.

[0035] Furthermore, at least one horizontal or vertical limiting component (corresponding to 112, 113 or 132, 133) is provided on the inner edge (corresponding to the inner hollow structure) of the frame body (corresponding to 110 or 130). When the frame body (corresponding to 110 or 130) is square, the limiting component (corresponding to 112, 113 or 132, 133) is provided on the opposite side of the frame body (corresponding to 110 or 130).

[0036] When the frame body (corresponding to 110 or 130) is circular, the limiting component (corresponding to 112, 113 or 132, 133) is set on the diameter of the frame body (corresponding to 110 or 130) or on the side adjacent to the diameter, and the limiting component (corresponding to 112, 113 or 132, 133) is integrally injection molded with the frame body (corresponding to 110 or 130).

[0037] Furthermore, a through hole (corresponding to 115 or 135) through which the screw can pass is provided in the defined component (corresponding to 112, 113 or 132, 133), and the current collector layer, proton exchange membrane 106 and diffusion layer assembly 104 are stacked.

[0038] Stainless steel end plates (corresponding to 10a and 10b) are installed at both ends of the membrane electrode frame assembly, such as... Figure 3 As shown, through holes 10c corresponding to the membrane electrode frame assembly are provided on the outer edge of the end plates (corresponding to 10a and 10b). The through holes 10c and the through holes (corresponding to 115 or 135) are arranged on the same axis. The end plates (corresponding to 10a and 10b) are then locked by screws. This ensures that when the proton exchange membrane 106 and the diffusion layer assembly 104 are stacked in multiple layers (such as 40 or 50 layers), the proton exchange membrane 106 will not bulge due to the lack of tension in the middle position or the area close to the middle position of the frame body (corresponding to 110 or 130), which would cause the resistance to increase.

[0039] Using this technical solution, by setting at least one limiting component (corresponding to 112, 113 or 132, 133) in the frame body (corresponding to 110 or 130), and setting a through hole (corresponding to 115 or 135) in the limiting component (corresponding to 112, 113 or 132, 133), when stacking the membrane electrode assembly, the end plate and the membrane electrode assembly are locked by the screw in the middle position of the end plate (corresponding to 10a and 10b) and the screw on the outer edge, so as to improve the adhesion between the current collector layer, the proton exchange membrane and the diffusion layer assembly. This can effectively solve the problem of the proton membrane bulging when multiple current collector layers and proton membranes are stacked, thereby reducing the resistance of the membrane electrode and improving the efficiency of electrolysis in the electrolytic reactor.

[0040] In some implementations, such as Figure 4 and Figure 5 As shown, in order to improve the tightness of the bonding between the proton exchange membrane 106 and the diffusion layer assembly 104, a first limiting component (corresponding to 112 or 132) and a second limiting component (corresponding to 113 or 133) can be provided in the limiting component. The first limiting component (corresponding to 112 or 132) and the second limiting component (corresponding to 113 or 133) are intersected in the frame body (corresponding to 110 or 130). A through hole (corresponding to 115 or 135) is provided at the intersection of the first limiting component (corresponding to 112 or 132) and the second limiting component (corresponding to 113 or 133). The through hole (corresponding to 115 or 135) and the through hole 10c on the end plate (corresponding to 10a and 10b) are engaged with a screw to apply a tightening force to the end plate (corresponding to 10a and 10b) and the frame body (corresponding to 110 or 130), thereby improving the tightness of the bonding between the proton exchange membrane 106 and the diffusion layer assembly 104.

[0041] The frame body (corresponding to 110 or 130) is provided with multiple positioning holes 140, the diameter of which is less than or equal to the diameter of the through hole (corresponding to 115 or 135).

[0042] In some implementations, such as Figure 4 and Figure 5 As shown, in order to ensure the tightness of the laminated structure of the membrane electrode assembly, the end faces of the first limiting component (corresponding to 112 or 132) and the second limiting component (corresponding to 113 or 133) can be horizontally set with the end face of the frame body (corresponding to 110 or 130).

[0043] This can be understood as the upper ends of the first limiting component (corresponding to 112 or 132) and the second limiting component (corresponding to 113 or 133) being horizontally positioned with the upper surface (corresponding to 150) of the frame body (corresponding to 110 or 130).

[0044] The width of the first limiting component (corresponding to 112 or 132) and the second limiting component (corresponding to 113 or 133) is greater than or equal to the width of the frame body (corresponding to 110 or 130).

[0045] In some implementations, such as Figure 4 and Figure 5 As shown, in order to ensure the smooth flow of the flow field, multiple water / gas channels can be provided on one end face of the first limiting component (corresponding to 112 or 132) and the second limiting component (corresponding to 113 or 133). For example, pure water is introduced through the water inlet 117 and forms a water flow field in the frame body (corresponding to 110 or 130) through the water channel. After electrolysis, hydrogen and oxygen are generated. The oxygen and the electrolyzed pure water are output to the pure water tank through the return water port 118, and the hydrogen is output from the hydrogen outlets (corresponding to 119 and 120) at both ends of the frame body (corresponding to 110 or 130).

[0046] In some implementations, such as Figure 4 As shown, in order to improve the sealing performance of the frame body (corresponding to 110 or 130), the through hole (corresponding to 115 or 135) can be extended upward along the end face of the first limiting member (corresponding to 112 or 132) or the second limiting member (corresponding to 113 or 133) (corresponding to 114), and a first sealing rib (corresponding to 116) is provided on the outer extension of the through hole (corresponding to 115 or 135).

[0047] The frame body (corresponding to 110 or 130) has multiple positioning holes 140 with equal or unequal spacing on its outer edge. A second sealing rib (corresponding to 125) is provided on the outer edge of the positioning hole 140. The first sealing rib (corresponding to 116) has the same height as the second sealing rib (corresponding to 125) on the end face of the frame body (corresponding to 110 or 130).

[0048] In some implementations, such as Figure 3 As shown, in order to improve the tightness of the bonding between the proton exchange membrane 106 and the diffusion layer assembly 104, a first through hole 10c corresponding to the through hole (corresponding to 115 or 135) can be provided on the end plate 10a. The first through hole 10c and the through hole (corresponding to 115 or 135) are arranged on the same axis. The screw 10d is passed through the first through hole 10c, the through hole (corresponding to 115 or 135) and the second through hole 10f on the end plate 10b, and then a tightening force is applied at the middle position of the frame body (corresponding to 110 or 130), thereby improving the tightness of the bonding between the proton exchange membrane 106 and the diffusion layer assembly 104 when the multilayer membrane electrode is stacked.

[0049] Furthermore, an anode 102, a proton exchange membrane 106, a felt, a cathode (not shown), and a conductive layer are stacked within the membrane electrode frame assembly. A third through hole (not shown) corresponding to the through hole (corresponding to 115 or 135) is provided in the anode 102, the proton exchange membrane 106, the cathode (not shown), and the conductive layer.

[0050] In some implementations, such as Figure 2 and Figure 7 As shown, in order to improve the reliability of the assembly between the frame body (corresponding to 110 or 130) and the diffusion layer assembly 104, the diffusion layer assembly 104 can be provided inside the frame body (corresponding to 110 or 130).

[0051] Among them, such as Figure 6 As shown, the diffusion layer assembly 104 is assembled in the hollow structure (corresponding to 111 and 113) of the frame body (corresponding to 110 or 130), and a step 104a is provided on the bottom outer edge of the diffusion layer assembly 104. When the two are in contact, the step 104a abuts against the inner side of the frame body (corresponding to 110 or 130), and the step 104a fits against the lip of the inner edge of the frame body (corresponding to 110 or 130), thereby improving the flatness of the fit between the diffusion layer assembly 104 and the proton exchange membrane 106.

[0052] An insulating pad 101 is provided between the end plate (corresponding to 10a) and the anode 102. The insulating pad 101 is provided to prevent the end plate (corresponding to 10a) from carrying current when the electrolytic reactor is working, thereby improving the safety of use.

[0053] The other end plate (corresponding to 10b) and the cathode (not shown) are also provided with insulating pads (not shown).

[0054] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A membrane electrode frame assembly, characterized in that, have: The frame body is formed as a hollow structure, and at least one limiting component is provided on the inner edge of the frame body, and a through hole is provided in the limiting component for the screw to pass through. When the frame body is circular, the limiting component is disposed on the diameter of the frame body or on the side adjacent to the diameter, and the limiting component is integrally injection molded with the frame body; When the frame body is square, the limiting component is arranged horizontally or vertically on opposite sides of the frame body; The limiting component includes a first limiting component and a second limiting component that are intersected and arranged together. A through hole is provided at the intersection of the first limiting component and the second limiting component; The end faces of the first limiting component and the second limiting component are horizontally aligned with the end face of the frame body; Water / gas channels are respectively provided on one end face of the first limiting component and the second limiting component; Stainless steel end plates are provided at both ends of the frame body. Through holes corresponding to the membrane electrode frame assembly are provided on the outer edge of the end plates. The through holes and the through holes are arranged on the same axis. The end plates are then locked by screws.

2. The membrane electrode frame assembly according to claim 1, characterized in that, The through hole extends upward along the end face of the first defining member or the second defining member.

3. The membrane electrode frame assembly according to claim 2, characterized in that, A first sealing rib is provided on both end faces of the through hole, and the first sealing rib has the same height as the second sealing rib on both end faces of the frame body.

4. A PEM electrolytic reactor, characterized in that, It includes the membrane electrode frame assembly as described in any one of claims 1-3 and end plates disposed at both ends of the membrane electrode frame assembly.

5. The PEM electrolytic reactor according to claim 4, characterized in that, A first through hole corresponding to the through hole is provided on the end plate, and the first through hole and the through hole are arranged on the same axis.

6. The PEM electrolytic reactor according to claim 5, characterized in that, An anode, a titanium mesh, a proton exchange membrane, a felt, a cathode, and a conductive layer are stacked within the membrane electrode frame assembly. The anode, the proton exchange membrane, the cathode, and the conductive layer are each provided with a third through hole corresponding to the through hole.

7. The PEM electrolytic reactor according to claim 5, characterized in that, A diffusion layer assembly is provided within the frame body. A step is provided on the bottom outer edge of the diffusion layer assembly that abuts against the frame body. The step fits into the lip of the inner edge of the frame body.

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