Bipolar plate, bipolar plate assembly, electrolytic stack and electrolytic bath

Abstract

The utility model provides a bipolar plate. The bipolar plate comprises a bipolar plate body, a pole frame, a convex step and at least one concave step, wherein the bipolar plate body comprises an anode surface and a cathode surface which are oppositely arranged; the electrode frame is positioned on the periphery of the bipolar plate body and comprises a first side surface positioned on the same side as the anode surface and a second side surface positioned on the same side as the cathode surface; the convex step is arranged on the first side surface around the periphery of the bipolar plate body and protrudes out of the first side surface; the at least one concave step is arranged on the second side face around the periphery of the bipolar plate body, and the concave step is sunken in the second side face. The bipolar plate is simple in structure and easy to process, the anode electrode plate, the cathode electrode plate and the diaphragm are convenient to mount, and the distance between the anode electrode plate and the cathode electrode plate is only equal to the thickness of the diaphragm, so that the use requirement of the zero-clearance electrolytic cell can be met.

Description

TECHNICAL FIELD

[0001] The utility model relates to electrolytic water hydrogen production technical field, especially a bipolar plate, bipolar plate assembly, electrolytic stack and electrolytic tank. BACKGROUND

[0002] With the proposal of the double carbon development goal, hydrogen energy gradually gets widespread attention and attention of people, wherein the electrolytic water hydrogen production technology using renewable energy is considered as the most potential, green and clean hydrogen production technology route because of no CO2 emission in the production process. The bipolar plate as the core component of the water electrolysis hydrogen production system, its structure directly affects the energy consumption and system performance of the water electrolysis reaction.

[0003] According to the different electrode spacing on the bipolar plate, it can be divided into limited gap electrolytic tank and zero gap electrolytic tank. Among them, the anode electrode and the cathode electrode of the limited gap electrolytic tank have a larger electrode distance (usually greater than 2mm), so as to reduce the gas cross of hydrogen and oxygen, but it will lead to larger ohmic resistance, which is difficult to match the hydrogen production demand under large current density, and also cannot be coupled with renewable energy such as wind and light, so the zero gap electrolytic tank technology has gradually replaced it.

[0004] The distance between the electrode and the diaphragm in the zero gap electrolytic tank is close to zero, that is, the electrode distance between the cathode electrode and the anode electrode is only the thickness of the diaphragm. In the prior art, the electrode is welded on the bipolar plate frame, and the zero gap electrolytic tank is obtained by adjusting the welding precision. This technology has very high requirements for the quality and precision of the weld, and when the electrolytic tank contains many single pieces, it is usually difficult to meet the electrode electrode distance precision requirements of the zero gap electrolytic tank. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a bipolar plate, bipolar plate assembly, electrolytic stack and electrolytic tank, to solve the technical problem of the bipolar plate in the prior art that is difficult to meet the electrode electrode distance precision requirements of the zero gap electrolytic tank.

[0006] To achieve the above-mentioned purpose, in the first aspect, the application provides a bipolar plate, which comprises:

[0007] A bipolar plate body comprising an anode surface and a cathode surface arranged oppositely;

[0008] A pole frame located at the outer periphery of the bipolar plate body, comprising a first side surface on the same side as the anode surface and a second side surface on the same side as the cathode surface;

[0009] A boss step is arranged on the first side surface around the outer periphery of the bipolar plate body, and the boss step protrudes from the first side surface;

[0010] At least one concave step is arranged on the second side around the outer periphery of the bipolar plate body, and the concave step is recessed from the second side.

[0011] Optionally, the bipolar plate specifically comprises a first concave step and a second concave step, and the first concave step and the second concave step share a common step surface;

[0012] Another step surface of the first concave step other than the common step surface is the second side, and another step surface of the second concave step other than the common step surface is protruded from the cathode surface; wherein the common step surface is recessed from the second side.

[0013] Optionally, one step surface of the convex step is the first side;

[0014] The distance between another step surface of the convex step and the first side is determined according to the corresponding step height of the at least one concave step, the thickness of the anode electrode plate, the thickness of the cathode electrode plate and the thickness of the diaphragm.

[0015] Optionally, the first slope surface of the convex step is flush with the inner edge of the polar frame, and the second slope surface of the convex step matches the slope surface of the concave step closest to the second side among the at least one concave step; the first slope surface of the convex step and the second slope surface of the convex step are oppositely arranged.

[0016] Optionally, the first side matches the second side.

[0017] Optionally, the thickness of the polar frame is greater than the thickness of the bipolar plate body.

[0018] In a second aspect, the present application provides a bipolar plate assembly, which comprises an anode electrode plate, a cathode electrode plate, a diaphragm and a bipolar plate as described above.

[0019] The anode electrode plate is fixedly connected with the step surface of the convex step;

[0020] The cathode electrode plate is fixedly connected with the step surface of one of the at least one concave step;

[0021] The diaphragm is fixedly connected with the step surface of another of the at least one concave step.

[0022] Optionally, the height of the concave step fixedly connected with the cathode electrode plate is determined according to the thickness of the cathode electrode plate.

[0023] In a third aspect, the present application provides an electrolysis stack, characterized in that the electrolysis stack comprises the bipolar plate as described above, or comprises the bipolar plate assembly as described above; and the electrolysis stack further comprises:

[0024] A sealing gasket is located between any two bipolar plate assemblies.

[0025] In a fourth aspect, the application provides an electrolytic cell comprising the bipolar plate described above, or comprising the bipolar plate assembly described above, or comprising the electrolytic stack described above.

[0026] Compared with the prior art, the application provides a bipolar plate, which comprises a bipolar plate body, a polar frame, a convex step and at least one concave step. The bipolar plate body comprises oppositely arranged anode and cathode surfaces. The polar frame is located at the outer periphery of the bipolar plate body and comprises a first side surface on the same side as the anode surface and a second side surface on the same side as the cathode surface. The convex step is arranged on the first side surface around the outer periphery of the bipolar plate body and protrudes from the first side surface. The at least one concave step is arranged on the second side surface around the outer periphery of the bipolar plate body and is recessed from the second side surface. The bipolar plate has a simple structure and is easy to process, facilitates the installation of anode and cathode electrode plates and diaphragms, and can ensure that the distance between the anode and cathode electrode plates is only the thickness of the diaphragm, thereby meeting the use requirements of a zero-gap electrolytic cell. In addition, any two bipolar plates can be engaged by the convex and concave steps, have good cooperation, facilitate the replacement of the bipolar plates, and greatly improve the maintenance and repair efficiency of the electrolytic cell. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A structural schematic diagram of a bipolar plate provided by an embodiment of the application;

[0028] Figure 2 A structural schematic diagram of a bipolar plate provided by an embodiment of the application;

[0029] Figure 3 A Figure 1 An enlarged view of a partial structure of the bipolar plate;

[0030] Figure 4 A Figure 2 An enlarged view of a partial structure of the bipolar plate;

[0031] Figure 5 A structural schematic diagram of a bipolar plate provided by an embodiment of the application, which is a combination of a front view, a sectional view and an enlarged sectional view;

[0032] Figure 6 A Figure 5 A structural schematic diagram of one side of the convex step in the enlarged sectional view;

[0033] Figure 7 A Figure 5 A structural schematic diagram of one side of the concave step in the enlarged sectional view;

[0034] Figure 8 For Figure 5 The structure schematic diagram of the protrusion step and the concave step matched in the middle local enlarged sectional view;

[0035] Figure 9 The structure schematic diagram of a bipolar plate assembly provided by the embodiment of the application.

[0036] In the drawings, the reference signs are explained as follows:

[0037] 11-bipolar plate body; 111-anode surface; 112-cathode surface; 12-pole frame; 121-first side surface; 122-second side surface; 13-protrusion step; 131-step surface; 132-step surface; 133-first slope surface; 134-second slope surface; 14-concave step; 141-first concave step; 1411-slope surface; 1412-step surface; 1413-step surface; 142-second concave step; 1421-step surface; 1422-step surface; 21-anode electrode plate; 22-cathode electrode plate; 31-anode small chamber; 32-cathode small chamber; 41-septum. DETAILED DESCRIPTION

[0038] In order to make the purpose, advantages and characteristics of the present application more clear, the method provided by the present application is further described in detail below in combination with the drawings. It should be noted that the drawings are all in a very simplified form and all use non-precise proportions, and are only used to facilitate and clearly assist the purpose of describing the embodiments of the present application.

[0039] In order to facilitate understanding of the present application, the present application is described in more detail below in combination with the drawings and specific embodiments.

[0040] It should be understood that when used in the specification and the appended claims of the present application, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0041] It should also be understood that the term "and / or" used in the specification and the appended claims of the present application means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0042] In the description of the present application and the appended claims, the terms "first", "second", and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0043] Reference within the specification of this application to "one embodiment" or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," and the like in the specification of the application do not necessarily refer to the same embodiment, unless otherwise noted. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.

[0044] Reference Figures 1 to 4 A structure schematic diagram of a bipolar plate is provided in the embodiments of the application, and the bipolar plate comprises a bipolar plate body 11, a polar frame 12, a convex step 13, and at least one concave step 14.

[0045] The bipolar plate body 11 can comprise an anode surface 111 and a cathode surface 112, and the anode surface 111 and the cathode surface 112 are oppositely arranged.

[0046] In the embodiments of the application, the material of the bipolar plate body 11 is not limited, and the bipolar plate body 11 can be a metal plate or a non-metal plate. The shape of the bipolar plate body 11 is also not limited, and the bipolar plate body 11 can be square, circular, round rectangular, or other shapes.

[0047] The polar frame 12 can be located at the outer periphery of the bipolar plate body 11, and comprises a first side surface 121 on the same side as the anode surface 111 and a second side surface 122 on the same side as the cathode surface 112.

[0048] Further, the first side surface 121 and the second side surface 122 are matched, that is, the first side surface 121 and the second side surface 122 are matched in shape and size. The first side surface 121 and the second side surface 122 can both be flat, that is, the included angle between the first side surface 121 and the top surface of the polar frame 12 is 90°, and the included angle between the second side surface 122 and the top surface of the polar frame 12 is also 90°; or the first side surface 121 and the second side surface 122 can both be inclined surfaces, and the included angle between the first side surface 121 and the top surface of the polar frame 12 and the included angle between the second side surface 122 and the top surface of the polar frame 12 are complementary angles; or the first side surface 121 and the second side surface 122 can be mutually matched arc surfaces.

[0049] Specifically, the thickness of the polar frame 12 can be greater than the thickness of the bipolar plate body 11, that is, when the polar frame 12 is connected with the bipolar plate body 11, the first side surface 121 of the polar frame 12 protrudes from the anode surface 111 of the bipolar plate body 11, and the second side surface 122 of the polar frame 12 protrudes from the cathode surface 112 of the bipolar plate body 11. After the polar frame 12 is connected with the bipolar plate body 11, the polar frame 12 can form a containing space with the anode surface 111 and the cathode surface 112, respectively, and the containing space can form the anode small chamber 31 and the cathode small chamber 32 after being connected with the anode electrode plate 21 and the cathode electrode plate 22.

[0050] Further, the distance between the first side surface 121 and the anode surface 111 is less than the distance between the second side surface 122 and the cathode surface 112, which is designed to make the sizes of the anode small chamber and the cathode small chamber consistent. The anode small chamber refers to the space enclosed by the anode surface 111, the polar frame 12 and the anode electrode plate, and the cathode small chamber refers to the space enclosed by the cathode surface 112, the polar frame 12 and the cathode electrode plate.

[0051] In the embodiment of the present application, the shape of the inner edge of the polar frame 12 can match the shape of the bipolar plate body 11, that is, if the bipolar plate body 11 is square, the inner edge of the polar frame 12 is also square; if the bipolar plate body 11 is circular, the inner edge of the polar frame 12 is also circular; if the bipolar plate body 11 is a round rectangle, the inner edge of the polar frame 12 is also a round rectangle.

[0052] In the embodiment of the present application, the shape of the outer edge of the polar frame 12 is not specifically limited, and can be consistent with the shape of the inner edge of the polar frame 12, or can be inconsistent with the shape of the inner edge of the polar frame 12, which can be set by the person skilled in the art according to experience or needs.

[0053] The specific structure of the convex step 13 and the concave step 14 will be described in detail below. Figures 5 to 8

[0054] The convex step 13 can be arranged on the first side surface 121 around the outer periphery of the bipolar plate body 11, and the convex step 13 protrudes from the first side surface 121.

[0055] Further, the convex step 13 includes two step surfaces (step surface 131 and step surface 132), a first slope surface 133 and a second slope surface 134. One of the two step surfaces of the convex step 13 can be the first side surface 121, and the other step surface 132 is arranged to protrude from the first side surface 121.

[0056] In addition, the distance between the other step surface 132 of the convex step 13 and the first side surface 121 (i.e. the distance between the step surface 132 and the first side surface 121) is greater than the distance between the first side surface 121 and the anode surface 111. Figure 6 ​L) shown in FIG. 1 can be closer to the step height corresponding to the at least one recessed step (i.e. Figure 7 H) shown in FIG. 1, the thickness of the anode electrode plate 21, the thickness of the cathode electrode plate 22, and the thickness of the separator 41. Further, the sum of L) shown in FIG. 1, the thickness of the anode electrode plate 21, the thickness of the cathode electrode plate 22, and the thickness of the separator 41 determines the distance between the anode electrode plate 21 and the cathode electrode plate 22. Figure 6 L) shown in FIG. 1 can be closer to the step height corresponding to the at least one recessed step (i.e. Figure 1 H) shown in FIG. 1, the thickness of the anode electrode plate 21, the thickness of the cathode electrode plate 22, and the thickness of the separator 41. Further, the sum of L) shown in FIG. 1, the thickness of the anode electrode plate 21, the thickness of the cathode electrode plate 22, and the thickness of the separator 41 determines the distance between the anode electrode plate 21 and the cathode electrode plate 22. Figure 7 H) shown in FIG. 1 can be equal to the distance between the anode electrode plate 21 and the cathode electrode plate 22. Figure 6 H) shown in FIG. 1, the thickness of the anode electrode plate 21, the thickness of the cathode electrode plate 22, and the thickness of the separator 41. In this case, the zero-pole distance can be achieved.

[0057] The first slope surface 133 and the second slope surface 134 in the convex step 13 can be oppositely arranged. The first slope surface 133 of the convex step 13 can be flush with the inner edge of the pole frame 12, or can not be flush with the inner edge of the pole frame 12, that is, there can be a distance between the first slope surface 133 and the inner edge of the pole frame 12.

[0058] The second slope surface 134 of the convex step 13 can match the slope surface of the recessed step closest to the second side surface 122 among the at least one recessed step. For example, the second slope surface 134 of the convex step 13 can match the slope surface of the first recessed step 141 closest to the second side surface 122 among the two recessed steps. Figure 1 For example, the structure of the bipolar plate shown in FIG. 1 includes two recessed steps, i.e., the first recessed step 141 and the second recessed step 142. In this case, the recessed step closest to the second side surface 122 is the first recessed step 141. That is, the second slope surface 134 of the convex step 13 can match the slope surface 1411 of the first recessed step 141. Here, the matching can mean that the second slope surface 134 of the convex step 13 and the slope surface 1411 of the first recessed step 141 match in shape and size, that is, when the two bipolar plates are stacked together, the convex step 13 in one bipolar plate can be combined with the first recessed step 141 in the other bipolar plate.

[0059] The at least one recessed step 14 can be arranged on the second side surface 122 around the outer periphery of the bipolar plate body 11, and the recessed step is recessed from the second side surface 122.

[0060] For example, the bipolar plate can include two recessed steps, for example, the first recessed step 141 and the second recessed step 142 shown in FIG. 1. Figure 1 For example, the bipolar plate can include two recessed steps, for example, the first recessed step 141 and the second recessed step 142 shown in FIG. 1. Figure 1The stepped surface 1412 (1421) shown in the middle can be recessed from the second side surface, and another stepped surface 1413 of the first recessed step 141, except for the shared stepped surface 1411, can be the second side surface 122. Another stepped surface 1422 of the second recessed step 142, except for the shared stepped surface 1421, can be protruded from the cathode surface 112.

[0061] In this way, the cathode electrode plate can be arranged on the second recessed step 142, and specifically on the stepped surface 1422 of the second recessed step 142; the diaphragm 41 can be arranged on the first recessed step 141, and specifically on the stepped surface 1412 of the first recessed step 141. Since the first recessed step 141 and the second recessed step 142 share the stepped surface 1412 (1421), the diaphragm 41 can also be said to be arranged on the stepped surface 1421 of the second recessed step 142.

[0062] With the structure of two recessed steps, the diaphragm 41 can be more flatly covered on the surface of the cathode electrode plate.

[0063] In another example, the bipolar plate can include one recessed step 14, and the cathode electrode plate 22 and the diaphragm 41 can be arranged on the stepped surface of the recessed step 14.

[0064] Further, the height of the first slope surface 133 of the convex step 13 (i.e. Figure 6 The distance between the stepped surface 1422 of the second recessed step 142 and the cathode surface 112 of the bipolar plate body 11 (i.e. Figure 7 The distance between the stepped surface 1422 of the second recessed step 142 and the cathode surface 112 of the bipolar plate body 11 (i.e.

[0065] In the embodiments of the present application, the number of recessed steps 14 is not specifically limited, and those skilled in the art can arrange the number of recessed steps 14 as needed.

[0066] Based on the same inventive concept, as Figure 9 shown, a structure schematic diagram of a bipolar plate assembly provided by the embodiments of the present application is provided, the bipolar plate assembly includes an anode electrode plate 21, a cathode electrode plate 22, a diaphragm 41, and a bipolar plate as described above;

[0067] The anode electrode plate 21 is fixedly connected with the stepped surface of the convex step 13;

[0068] The cathode electrode plate 22 is fixedly connected with the stepped surface of one of the at least one recessed step 14;

[0069] The diaphragm 41 is fixedly connected with the step surface of the other one of the at least one concave step 14.

[0070] Optionally, the height of the concave step fixedly connected with the cathode electrode plate 22 is determined according to the thickness of the cathode electrode plate 22.

[0071] The application further provides an electrolytic stack, characterized in that the electrolytic stack comprises the bipolar plate described above, or comprises the bipolar plate assembly described above; and the electrolytic stack further comprises:

[0072] A sealing gasket is arranged between any two bipolar plate assemblies.

[0073] The application further provides an electrolytic tank, which comprises the bipolar plate described above, or comprises the bipolar plate assembly described above, or comprises the electrolytic stack described above.

[0074] The above description is only a description of the preferred embodiments of the application, and does not limit the scope of the application in any way, and any modification or change made by a person skilled in the art according to the above disclosure is within the protection scope of the claims.

Claims

1. A bipolar plate, characterized in that, The bipolar plate includes: The bipolar plate body includes an anode surface and a cathode surface arranged opposite to each other; The electrode frame is located on the outer periphery of the bipolar plate body and includes a first side surface on the same side as the anode surface and a second side surface on the same side as the cathode surface. A raised step is provided on the first side surface around the outer periphery of the bipolar plate body, and the raised step protrudes from the first side surface. At least one concave step is disposed on the second side surface around the outer periphery of the bipolar plate body, and the concave step is recessed into the second side surface.

2. The bipolar plate according to claim 1, characterized in that, The bipolar plate specifically includes a first concave step and a second concave step, wherein the first concave step and the second concave step share a common step surface; The first concave step has another step surface other than the common step surface as the second side surface, and the second concave step has another step surface other than the common step surface protruding from the cathode surface; wherein the common step surface is recessed into the second side surface.

3. The bipolar plate according to claim 1, characterized in that, One of the steps of the convex step is the first side surface; The distance between the other step surface of the convex step and the first side surface is determined based on the step height corresponding to the at least one concave step, the thickness of the anode electrode plate, the thickness of the cathode electrode plate, and the thickness of the diaphragm.

4. The bipolar plate according to claim 1, characterized in that, The first slope of the convex step is flush with the inner edge of the pole frame, and the second slope of the convex step matches the slope of the concave step that is closest to the second side in the at least one concave step; the first slope of the convex step and the second slope of the convex step are arranged opposite to each other.

5. The bipolar plate according to claim 1, characterized in that, The first side matches the second side.

6. The bipolar plate according to any one of claims 1 to 5, characterized in that, The thickness of the polar frame is greater than the thickness of the bipolar plate body.

7. A bipolar plate assembly, characterized in that, The bipolar plate assembly includes an anode electrode plate, a cathode electrode plate, a diaphragm, and a bipolar plate as described in any one of claims 1 to 6; The anode electrode plate is fixedly connected to the step surface of the convex step; The cathode electrode plate is fixedly connected to the step surface of one of the at least one concave steps; The diaphragm is fixedly connected to the step surface of another concave step in the at least one concave step.

8. The bipolar plate assembly according to claim 7, characterized in that, The height of the concave step fixedly connected to the cathode electrode plate is determined based on the thickness of the cathode electrode plate.

9. An electrolytic reactor, characterized in that, The electrolytic reactor includes a bipolar plate as described in any one of claims 1 to 6, or includes a bipolar plate assembly as described in claim 7 or 8; the electrolytic reactor further includes: A sealing gasket is located between any two bipolar plate assemblies.

10. An electrolytic cell, characterized in that, The electrolytic cell includes a bipolar plate as described in any one of claims 1 to 6, or a bipolar plate assembly as described in claim 7 or 8, or an electrolytic stack as described in claim 9.

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