Polar plate assembly for electrolysis unit, electrolysis unit and electrolysis stack

Abstract

The present application provides a pole plate assembly for an electrolysis cell, comprising: a pole plate having a first side and a second side opposite to each other, the first side of the pole plate being provided with a first recess for receiving a fluid; the cover plate is provided with a first side and a second side which are opposite to each other, the first side of the cover plate and the first side of the polar plate face each other, and the second side of the cover plate is configured to be used for supporting an exchange membrane of the electrolysis unit; the electrode layer is arranged between the polar plate and the cover plate, so that a preset distance is kept between the electrode layer and the exchange membrane, the polar plate is further provided with an input channel for inputting the fluid into the first concave part, and the cover plate covers the input channel and the electrode layer. The invention further provides an electrolysis unit comprising the polar plate assembly and an electrolysis stack.

Description

Technical Field

[0001] This application relates to the field of electrochemical batteries, and more particularly to an electrode assembly for an electrolysis unit, an electrolysis unit including the electrode assembly, and an electrolysis stack including the electrolysis unit. Background Technology

[0002] With the development of new energy technologies, hydrogen energy, as a centralized renewable energy carrier, has attracted increasing attention due to its characteristics of zero pollution, high energy, and wide availability. Currently, there are many methods for hydrogen production, among which the use of electrolytic reactors has become a research hotspot in the field, and electrolytic reactors have become key equipment for hydrogen production.

[0003] An electrolytic reactor typically comprises multiple electrolytic cells stacked together, end plates for securing the cells together, and piping and wiring for supplying water (or alkaline solution), power, and coolant to the cells. Each electrolytic cell typically includes, in sequence, an anode plate, a porous anode transport layer, an anode electrode layer (including an anode catalyst), an exchange membrane (e.g., a proton exchange membrane (PEM), an anion exchange membrane (AEM), or a diaphragm), a cathode electrode layer (including a cathode catalyst), a porous cathode transport layer, and a cathode plate. The anode and cathode plates can be formed as bipolar plates or monopolar plates, and can be simply referred to as plates.

[0004] In existing electrolysis units, porous materials (such as foam, mesh, or felt products) are typically used as electrodes and porous transport layers. However, incomplete contact may occur at the electrode layer-plate interface, leading to high ohmic losses, and the sharp surfaces of the porous materials may come into contact with and puncture the exchange membrane. Perforation of the exchange membrane can cause hydrogen permeation or leakage, thereby reducing hydrogen production efficiency and increasing the risk of explosion.

[0005] Furthermore, in existing electrolysis units, water or alkaline solutions directly enter the electrode layer through the channels of the electrode plates, scouring the catalyst within the electrode layer. This can cause catalyst detachment, reducing the catalyst's stability and durability.

[0006] In addition, the assembly of multiple individual components of the electrolysis unit during the manufacturing process is very time-consuming and prone to assembly errors, such as misalignment, deformation, and excessive stress, which leads to low production efficiency and quality problems.

[0007] Therefore, existing electrolytic reactors and their electrolysis units need to be improved to enhance their safety, stability, and ease of assembly and maintenance. Summary of the Invention

[0008] The purpose of this application is to provide an improved electrode assembly for an electrolysis unit, an electrolysis unit including the electrode assembly, and an electrolysis stack including the electrolysis unit, to overcome at least one of the above-mentioned technical problems.

[0009] Therefore, according to one aspect of this application, an electrode assembly for an electrolysis unit is provided, comprising: an electrode having a first side and a second side opposite to each other, the first side of the electrode having a first recess for receiving fluid; a cover plate having a first side and a second side opposite to each other, the first side of the cover plate facing the first side of the electrode, the second side of the cover plate being configured to support an exchange membrane of the electrolysis unit; and an electrode layer disposed between the electrode and the cover plate such that the electrode layer maintains a predetermined distance from the exchange membrane, wherein the electrode further comprises an input channel for inputting the fluid into the first recess, and the cover plate covering the input channel and the electrode layer.

[0010] According to another aspect of this application, an electrolysis unit is provided, comprising: an exchange membrane; and an anode plate assembly and a cathode plate assembly respectively disposed on both sides of the exchange membrane, wherein the anode plate assembly and the cathode plate assembly are configured as plate assemblies as described above.

[0011] According to another aspect of this application, an electrolytic stack is provided, comprising: a plurality of electrolytic units arranged adjacent to each other as described above; and a first end plate and a second end plate configured to clamp and secure the plurality of electrolytic units together.

[0012] The electrode assembly of this application defines a space for accommodating the electrode layer by defining the electrode plate and the cover plate, thereby maintaining a predetermined distance or gap between the electrode layer and the exchange membrane to prevent damage to the exchange membrane. When a porous transport layer is provided, the cover plate also covers the electrode layer and the porous transport layer, maintaining their flatness and ensuring sufficient electrical contact between the electrode layer, the porous transport layer, and the electrode plate. It also covers the inlet channel for fluid transport, supports the sealing member (thus eliminating the need for an additional support plate), and prevents the sealing member from deforming and entering the channel of the electrode plate, thus affecting the flow of water or alkaline solutions.

[0013] Furthermore, water or alkaline solutions can flow directly from the channels of the electrode plates to the area below the electrode layer, rather than directly scouring the electrode layer. This helps reduce the impact of water or alkaline solutions on the catalyst within the electrode layer, ensuring the catalyst's stability and durability. In addition, the electrode plates, cover plates, electrode layers, and porous transport layers can be integrated into a single component through welding or other methods. This further ensures strong electrical contact between the electrode layers and the porous transport layers and the electrode plates, and facilitates the assembly and disassembly of the electrolysis unit. Consequently, this improves the manufacturability, maintainability, reliability, and cost-effectiveness of the electrolysis unit and electrolytic stack. Attached Figure Description

[0014] Exemplary embodiments of this application will now be described in detail with reference to the accompanying drawings. It should be understood that the embodiments described below are for illustrative purposes only and are not intended to limit the scope of this application. In the accompanying drawings:

[0015] Figure 1 This is a schematic cross-sectional view of an electrolytic stack including an electrolysis unit according to an embodiment of this application;

[0016] Figure 2 According to an embodiment of this application, it is used for Figure 1 A schematic top view of the electrode assembly of the electrolysis unit shown;

[0017] Figure 3 , Figure 4 and Figure 5 They are along Figure 2 A schematic cross-sectional view of the electrode assembly taken by lines AA, BB, and CC, wherein... Figure 4 and Figure 5 The image also shows the exchange membrane of the electrolysis unit;

[0018] Figure 6 This is an embodiment according to this application. Figure 2 A schematic top view of the electrode plates of the electrode assembly shown;

[0019] Figure 7 , Figure 8 and Figure 9 They are along Figure 6 A schematic cross-sectional view of the electrode plates taken by lines A′-A′, B′-B′, and C′-C′.

[0020] Figure 10 This is an embodiment according to this application. Figure 2 A schematic bottom view of the cover plate of the electrode assembly shown;

[0021] Figure 11 It is along Figure 10 A schematic cross-sectional view of the cover plate taken by line DD in the diagram;

[0022] Figure 12 It is an embodiment of this application that can be included Figure 2 A schematic top view of the sealing member in the electrode assembly shown. Detailed Implementation

[0023] Preferred embodiments of this application are described in detail below with reference to examples. Those skilled in the art should understand that these exemplary embodiments do not imply any limitation on this application. Furthermore, features in the embodiments of this application can be combined with each other unless otherwise specified. In different drawings, identical components are represented by the same reference numerals, and other components are omitted for brevity; however, this does not mean that the electrode assembly, electrolysis unit, and electrolytic stack of this application cannot include other components or modules. It should be understood that the dimensions, proportions, and number of components in the drawings are not intended to limit this application.

[0024] The following reference Figure 1 This describes an electrolytic reactor according to an embodiment of the present application. For example... Figure 1 As shown, the electrolytic stack 300 includes multiple electrolytic units 200 arranged adjacent to each other. Figure 1 (Only two electrolysis units are shown as an example), and a first end plate 310 and a second end plate 320 are respectively disposed at both ends of the plurality of electrolysis units 200. The first end plate 310 and the second end plate 320 are configured to clamp and fix the plurality of electrolysis units 200 together. Figure 1 As shown, the first end plate 310 is provided with inlets 311 and 312 for supplying water (or other solutions, such as alkaline solutions) to the cathode and anode sides of the electrolysis unit 200, respectively; a coolant inlet 313 for supplying coolant to a coolant channel (not shown) of the electrolysis unit 200; a hydrogen outlet 314 for discharging hydrogen generated on the cathode side of the electrolysis unit 200; an oxygen outlet 315 for discharging oxygen (or other gases) generated on the anode side of the electrolysis unit 200; and a coolant outlet 316 for discharging coolant. It should be noted that the various ports described above can also be provided on the second end plate 320, or on both the first end plate 310 and the second end plate 320. Furthermore, the lines and pipes for supplying power, water (or other solutions), and coolant to the electrolysis unit 200 can employ any other configuration and construction in the prior art, and therefore will not be described further herein.

[0025] like Figure 1 As shown, the electrolysis unit 200 includes an exchange membrane 130 and an anode plate assembly 110 and a cathode plate assembly 120 respectively disposed on both sides of the exchange membrane 130, wherein the anode plate assembly 110 and the cathode plate assembly 120 are configured as follows (see below) Figure 2 The electrode assembly 100 is described in further detail.

[0026] In the electrolysis unit 200, the exchange membrane 130 can be a proton exchange membrane, an anion exchange membrane, or a diaphragm (used in conventional alkaline electrolyzers). The electrolysis unit 200 can be filled with water or an alkaline solution, and the generated gas is not limited to hydrogen and oxygen. For example, in an electrolysis unit where the exchange membrane 130 is a proton exchange membrane, pure water can be filled, while in an electrolysis unit where the exchange membrane 130 is an anion exchange membrane, an alkaline solution (or pure water) can be filled. A sealing gasket 131 can be provided around the periphery of the exchange membrane 130 to allow for a reliable attachment seal structure to be formed around the exchange membrane 130 in a simple manner. The sealing gasket 131 can be made of materials such as PVC, polycarbonate, ABS, silicone, polyurethane, etc., and can be integrally formed with the exchange membrane 130.

[0027] The following reference Figures 2 to 12 The present application describes an electrode assembly 100 for an electrolysis unit. The electrode assembly 100 includes an electrode 10, a cover plate 20, and an electrode layer 30 located between the electrode 10 and the cover plate 20.

[0028] The electrode plate 10 can be a stamped metal plate, a composite material plate, etc. For example... Figures 6 to 9 As shown, electrode 10 has a first side and a second side opposite to each other, and the first side of electrode 10 is provided with a first recess 11 for receiving fluid. The first recess 11 is used to receive fluid (e.g., water or an alkaline solution) and defines an effective area for the electrolysis reaction. Grooves may be provided in the first recess 11 to allow fluid to flow within the grooves (therefore, the first recess 11 may be referred to as the flow field region), and the electrode layer 30 is supported on the grooves. Figure 6 As shown, an input channel 12 for introducing fluid into the first recess 11 and an output channel 15 for discharging fluid from the first recess 11 may be provided at the end (or side) of the electrode plate 10. Correspondingly, the electrode plate 10 also provides an input port 14 for conveying fluid to the input channel 12 and an output port 16 for discharging fluid from the output channel 15, such as... Figure 9 As shown. It should be noted that, in Figure 2 The diagram only shows input port 14, which includes three sub-ports for supplying water or alkaline solution to the cathode and anode sides of the electrolysis unit 200, and for supplying coolant to the electrolysis unit 200, respectively. However, this application is not limited to this; the electrode plate 10 may be provided with ports and channels of various structures and configurations.

[0029] It should be noted that although the electrode plate 10 is shown as a single electrode plate in the accompanying drawings of this application, it can be connected together by means of welding, bonding, etc., to form a bipolar plate, and the principles of this application also apply. In the case of forming a bipolar plate, a coolant channel can be formed between the anode plate and the cathode plate.

[0030] According to another embodiment of this application, such as Figure 4and Figure 5 As shown, the electrode assembly 100 may further include a porous transport layer 40, a first recess 11 configured to receive the porous transport layer 40, and an electrode layer 30 supported on the porous transport layer 40. In this case, the first recess 11 may have a flat bottom surface without forming a trench to facilitate processing. As another embodiment, when the electrode assembly 100 includes the porous transport layer 40, a trench may also be formed in the first recess 11 to facilitate fluid flow.

[0031] Electrode layer 30 can typically be a metal mesh, metal foam, or other porous conductive material (e.g., aluminum, nickel or their alloys, titanium or their alloys, stainless steel, carbon, or graphite) with a mesh size or pore size less than 1 mm to increase the contact area with water or alkaline solutions, thereby improving hydrogen production efficiency. Electrode layer 30 may include a catalyst, such as a platinum, palladium, or ruthenium-based catalyst. When electrode layer 30 comes into contact with water or alkaline solutions, an electrochemical reaction occurs under the action of the catalyst. Porous transport layer 40 can adopt a porous structure similar to electrode layer 30, such as foam products, mesh products, or felt products.

[0032] The cover plate 20 can also be a stamped metal plate, a composite material plate, etc., but it can also be an insulating polymer material. For example... Figure 2 , Figure 10 and Figure 11 As shown, the cover plate 20 has a first side and a second side opposite to each other. The first side of the cover plate 20 faces the first side of the electrode plate 10, and the second side of the cover plate 20 is configured to support the exchange membrane 130 of the electrolysis unit 200. When the electrode plate 10 and the cover plate 20 are stacked together, the electrode layer 30 is disposed between the electrode plate 10 and the cover plate 20. Due to the thickness of the cover plate 20, the electrode layer 30 is kept at a predetermined distance from the exchange membrane 130, such as... Figure 4 and Figure 5 As shown. Therefore, the sharp portions of the electrode layer 30 surface will not puncture the exchange membrane, thereby preventing hydrogen permeation or leakage and improving production efficiency and safety. By adjusting the thickness of the cover plate 20, the efficiency and performance between the exchange membrane 130 and the electrode layer 30 can be optimized to achieve the desired effect.

[0033] like Figure 2 , Figure 4 and Figure 5 As shown, the cover plate 20 covers the electrode layer 30 and the porous transport layer 40, thus maintaining the flatness of the electrode layer 30 and the porous transport layer 40 and improving the electrical contact between the electrode layer 30 and the porous transport layer 40 and the electrode plate 10. The cover plate 20 also covers the input channel 12. With the first side of the electrode plate 10 facing upwards, the input channel 12 is located below the electrode layer 30. When water or alkaline solution enters the input channel 12, it flows directly below the electrode layer 30 instead of directly scouring the electrode layer 30. Figure 9 As shown. This reduces the erosion of the catalyst within the electrode layer 30, preventing catalyst shedding and thus maintaining the stability and durability of the catalyst. Similarly, the cover plate 20 can also cover the output channel 15.

[0034] like Figure 4 , Figure 5 , Figure 10 and Figure 11 As shown, the cover plate 20 has a cover plate recess 21 on its first side for receiving the electrode layer 30, and an opening 22 communicating with the cover plate recess 21 on its second side. Thus, when the cover plate 20 is stacked on the electrode plate 10, the electrode layer 30 is contained within the cover plate recess 21, preventing the electrode layer 30 from contacting the exchange membrane 130. The opening 22 allows hydrogen ions generated in the reaction to pass through the exchange membrane 130.

[0035] like Figure 10 As shown, according to one embodiment of this application, the cover plate 20 may include an outer edge portion 23 surrounding the periphery of the cover plate 20, an inner edge portion 24 located inside the outer edge portion 23, and a sidewall portion 25 connecting the outer edge portion 23 and the inner edge portion 24, the inner edge portion 24 and the sidewall portion 25 defining a cover plate recess 21. However, this application is not limited to the specific structure of the cover plate described and shown. For example, if the first recess 11 of the electrode plate 10 is sufficient to accommodate the electrode layer 30, the cover plate 20 may be a flat plate with an opening 22, without a cover plate recess 21. In addition, the outer edge portion 23 of the cover plate 20 may have various heights to form a step with the inner edge portion 24, but it may also be flush with the inner edge portion 24.

[0036] When the outer dimension of the outer edge portion 23 is smaller than the outer dimension of the electrode plate 10, a second recess 13 located outside the first recess 11 may be provided on the first side of the electrode plate 10. The second recess 13 is configured to receive the outer edge portion 23 of the cover plate 20. As another exemplary embodiment, the outer dimension of the outer edge portion 23 may be the same as the outer dimension of the electrode plate 10. In this case, the electrode plate 10 may not have the second recess 13. Figure 11 As shown, when the outer edge 23 is received within the second recess 13, the outer edge 23 can be aligned with the first side of the electrode plate 10 to facilitate placement of the sealing member 50 (which will be referred to below). Figure 12 (to describe), such as Figures 3 to 5 As shown.

[0037] To further improve the electrical contact between the electrode layer 30 and the porous transport layer 40 and the electrode plate 10, and to maintain better flatness of the electrode layer 30 and the porous transport layer 40, the outer edge 23 can be welded to the first side of the electrode plate 10, such as... Figure 2The first weld 18 is shown in the figure. Thus, the electrode assembly 100 is formed as a single unit. Therefore, during the manufacturing process of the electrolysis unit 200, the more fragile and flexible exchange membrane 130 can be manufactured separately from the more robust and rigid electrode assembly 100, allowing for different processes and precisions to be applied according to different characteristics. Furthermore, the electrode assembly 100, being formed as a single unit, can have greater rigidity than its individual components, thus facilitating manipulation during assembly. Because the electrode assembly 100 is formed as a single unit, it is easier to disassemble, replace, and reassemble. Therefore, according to the technical solution of this application, the manufacturability, maintainability, and reliability of the electrolysis unit and electrolysis stack can be improved, and significant cost-effectiveness can be achieved. It should be noted that the terms "single" and "integrated" as used herein mean that at least two components are connected or integrated into a single unit in a manner that prevents disassembly without damaging either component.

[0038] Furthermore, to further improve the electrical contact between the electrode layer 30 and the porous transport layer 40 and the electrode plate 10, the electrode layer 30 and the porous transport layer can be welded to the electrode plate 10. For example, the electrode layer 30 and the porous transport layer 40 can be welded to the electrode plate 10 at a position overlapping with the first recess 11. Figure 2 The second weld 19 is shown. It should be understood that, without the porous transport layer 40, the electrode layer 30 can be welded directly onto the electrode plate 10.

[0039] like Figures 3 to 5 As shown, the electrode assembly 100 may further include a sealing member 50, which is disposed on the second side of the cover plate 20. Due to the supporting effect of the cover plate 20, the sealing member 50 will not bend and enter the inlet channel 12, thereby avoiding interference with fluid flow. It should be noted that, for the sake of simplicity, in Figure 2 The sealing component 50 is omitted in the middle, while Figures 3 to 5 The sealing member is shown. The sealing member 50 can be formed by injection molding at the outer edge 23 of the cover plate 20 from any one of ethylene propylene diene monomer (EPDM) rubber, silicone rubber, fluororubber, and neoprene rubber. The sealing member 50 may have a port portion communicating with the aforementioned ports for supplying water and coolant to the electrolysis unit 200. For example... Figure 12 As shown, the sealing member 50 may include an input port portion 51 and an output port portion 52, and an opening portion 53 located between the input port portion 51 and the output port portion 52. The input port portion 51 corresponds to the input port 14 of the electrode plate 10, the output port portion 52 corresponds to the output port 16 of the electrode plate 10, and the opening portion 53 corresponds to the first recess 11 of the electrode plate 10.

[0040] When assembling the electrolysis unit 200, two electrode assemblies can be provided, one of which is an anode electrode assembly including an anode electrode layer, and the other is a cathode electrode assembly including a cathode electrode layer. Then, the exchange membrane 130 is sandwiched between these two electrode assemblies to complete the assembly of the electrolysis unit 200.

[0041] When assembling the electrolytic reactor 300, multiple electrolytic units 200 can be arranged adjacent to each other. Then, the adjacently arranged electrolytic units 200 are clamped together by the first end plate 310 and the second end plate 320, thereby forming multiple electrolytic chambers within the electrolytic reactor 300. In addition, the electrolytic reactor 300 may also include, for example, a shell, a power supply device, and a control device.

[0042] According to various embodiments of this application, the electrode assembly can maintain a certain distance between the exchange membrane of the electrolysis unit and the electrode layer, ensure the flatness of the electrode layer and the porous transport layer, improve the electrical contact between the electrode layer and the porous transport layer and the electrode plate, and can be formed into an integral component, thereby facilitating the manufacturing and subsequent maintenance of the electrolysis unit and the electrolysis stack.

[0043] The present application has been described in detail above with reference to specific embodiments. Obviously, the above description and the embodiments shown in the accompanying drawings should be understood as exemplary and not as limiting the present application. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and such modifications or alterations do not depart from the scope of the present application.

Claims

1. An electrode assembly (100) for an electrolysis unit (200), comprising: An electrode (10) having a first side and a second side opposite to each other, wherein the first side of the electrode (10) is provided with a first recess (11) for receiving fluid; A cover plate (20) having a first side and a second side opposite to each other, the first side of the cover plate (20) facing the first side of the electrode plate (10), and the second side of the cover plate (20) being configured to support the exchange membrane (130) of the electrolysis unit (200); and An electrode layer (30) is disposed between the electrode plate (10) and the cover plate (20) such that the electrode layer (30) maintains a predetermined distance from the exchange membrane (130). The electrode plate (10) is further provided with an input channel (12) for inputting the fluid into the first recess (11), and the cover plate (20) covers the input channel (12) and the electrode layer (30).

2. The electrode assembly (100) according to claim 1, wherein, When the first side of the electrode plate (10) is facing upward, the input channel (12) is located below the electrode layer (30).

3. The electrode assembly (100) according to claim 1 or 2, wherein, The electrode assembly (100) further includes a porous transport layer (40), the first recess (11) is configured to receive the porous transport layer (40), and the electrode layer (30) is supported on the porous transport layer (40).

4. The electrode assembly (100) according to claim 1 or 2, wherein, The first recess (11) is provided with a groove, the fluid flows in the groove, and the electrode layer (30) is supported on the groove.

5. The electrode assembly (100) according to claim 1, wherein, The cover plate (20) has a cover plate recess (21) on its first side for receiving the electrode layer (30), and the cover plate (20) has an opening (22) communicating with the cover plate recess (21) on its second side.

6. The electrode assembly (100) according to claim 5, wherein, The cover plate (20) includes an outer edge portion (23) surrounding the periphery of the cover plate (20), an inner edge portion (24) located inside the outer edge portion (23), and a sidewall portion (25) connecting the outer edge portion (23) and the inner edge portion (24), the inner edge portion (24) and the sidewall portion (25) defining the cover plate recess (21).

7. The electrode assembly (100) according to claim 6, wherein, The first side of the electrode plate (10) is also provided with a second recess (13) located outside the first recess (11), and the second recess (13) is configured to receive the outer edge (23) of the cover plate (20).

8. The electrode assembly (100) according to claim 7, wherein, When the outer edge (23) is received in the second recess (13), the outer edge (23) is aligned with the first side of the electrode plate (10).

9. The electrode assembly (100) according to claim 6, wherein, The outer edge (23) has the same external dimensions as the electrode plate (10); and / or The outer edge (23) is welded to the first side of the electrode plate (10).

10. The electrode assembly (100) according to claim 1, wherein, The electrode assembly (100) further includes a sealing member (50) disposed on the second side of the cover plate (20).

11. The electrode assembly (100) according to claim 3, wherein, The electrode layer (30) and the porous transport layer (40) are welded to the electrode plate (10) at a position overlapping with the first recess (11).

12. The electrode assembly (100) according to claim 1, wherein, The electrode layer (30) is a porous material and contains a catalyst.

13. An electrolysis unit (200), comprising: Exchange membrane (130); and An anode plate assembly (110) and a cathode plate assembly (120) are respectively disposed on both sides of the exchange membrane (130), wherein the anode plate assembly (110) and the cathode plate assembly (120) are configured as the plate assembly (100) according to any one of claims 1 to 12.

14. An electrolytic reactor (300), comprising: Multiple electrolysis units (200) arranged adjacent to each other according to claim 13; and A first end plate (310) and a second end plate (320) are configured to clamp and fix the plurality of electrolysis units (200) together.

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