Sealing gasket and electrolyzer

Abstract

Provided in the present application are a sealing gasket and an electrolyzer. The sealing gasket comprises: an outer sealing portion provided with a hollow structure; and an inner sealing portion at least partially arranged in the hollow structure. The resilience rate of the inner sealing portion is greater than that of the outer sealing portion, and the compressive stress of the outer sealing portion is greater than that of the inner sealing portion, such that when the sealing gasket is clamped and fixed by two adjacent cell frames, the inner sealing portion can exhibit a sufficient sealing capability at an inner sealing position, and the outer sealing portion can have sufficient support strength at an outer sealing position, so as to ensure a cell gap. Thus, on the basis of the differentiated design of the resilience rate and the compressive stress of the outer sealing portion and the inner sealing portion, the outer sealing portion and the inner sealing portion can complement each other's strengths, such that the sealing gasket of the present application can simultaneously meet the requirements for the sealing capabilities and support strength at different positions between cell frames. In addition, the sealing gasket of the present application is also applicable to large electrolyzers.

Description

Sealing gaskets and electrolytic cells

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese application No. 2024231682025, entitled "Sealing Gasket and Electrolytic Cell", filed on December 20, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of water electrolysis for hydrogen production technology, and in particular relates to a sealing gasket and an electrolytic cell. Background Technology

[0004] The sealing gasket of the water electrolysis hydrogen production electrolyzer is one of the core components of the electrolyzer body. It mainly plays a role in sealing, insulation, ensuring the gap between the small chambers, and bearing the load between the electrode frames.

[0005] In existing hydrogen electrolyzers, the electrode frames are typically sealed using either polytetrafluoroethylene (PTFE) gaskets or pure ethylene propylene rubber (EPR) gaskets. PTFE gaskets use PTFE, a special engineering material with high decomposition temperature, low brittleness temperature, and resistance to strong alkalis. However, it has poor resilience and high creep rate, leading to rapid degradation of its sealing ability over long-term use. This poses a higher risk, especially in green electricity and green hydrogen applications, particularly at the inner sealing position of the gasket where low compression and small rebound make it more prone to loosening and failure. EPR gaskets, on the other hand, are primarily made of ethylene propylene rubber, offering excellent resistance to weathering, heat and oxygen, and strong alkalis. However, their compressive stress is relatively low, making it difficult to support the weight of the electrolyzer, especially large ones. Summary of the Invention

[0006] This application provides a sealing gasket and an electrolytic cell to solve the technical problems of rapid decay of the sealing capacity of the inner side of the polytetrafluoroethylene gasket and insufficient support performance of the ethylene propylene rubber gasket.

[0007] According to one aspect of this application, a sealing gasket is provided for use in an electrolytic cell and includes: an outer sealing portion having a hollow structure; and an inner sealing portion, at least partially disposed within the hollow structure. The inner sealing portion has a greater resilience than the outer sealing portion, and the outer sealing portion has a greater compressive stress than the inner sealing portion.

[0008] In an optional embodiment of this application, the resilience of the inner sealing part is 50%-100%, and the compressive stress is 1MPa-25MPa.

[0009] In an optional embodiment of this application, the rebound rate of the outer sealing part is 2% to 85%, and the compressive stress is 8MPa to 100MPa.

[0010] In an optional embodiment of this application, the compression set rate of the inner sealing portion is less than that of the outer sealing portion.

[0011] In an optional embodiment of this application, the compression set rate of the inner sealing portion is no higher than 60%, and the creep relaxation rate is 2% to 50%.

[0012] In an optional embodiment of this application, the compression set of the outer sealing part is 40%-95%, the compression rate is 2%-50%, and the creep relaxation rate is 5%-70%.

[0013] In an optional embodiment of this application, the thickness of the outer sealing part is d1, and the thickness of the inner sealing part is d2, where d2 = (70% to 110%)d1.

[0014] In an optional embodiment of this application, the width of the outer sealing part is 5mm to 200mm, and the thickness of the outer sealing part is 0.1mm to 50mm.

[0015] In an optional embodiment of this application, the width of the inner sealing part is 5mm to 200mm, and the thickness of the inner sealing part is 0.1mm to 50mm.

[0016] In an optional embodiment of this application, the outer sealing part is made of a mixture of polytetrafluoroethylene and a filler, wherein the filler includes at least one of glass fiber, carbon fiber, barium sulfate, carbon powder, quartz powder, molybdenum disulfide, graphite powder, and polyimide. The inner sealing part is made of a rubber material, wherein the rubber material includes at least one of ethylene propylene rubber, fluororubber, silicone rubber, ethylene-vinyl acetate copolymer rubber, and thermoplastic elastomer.

[0017] In an optional embodiment of this application, at least one of the inner sealing portion and the outer sealing portion overlaps or is embedded in the other to connect the inner sealing portion and the outer sealing portion.

[0018] In an optional embodiment of this application, the length of the connection portion between the inner sealing portion and the outer sealing portion does not exceed 20% of the width of either the inner sealing portion or the outer sealing portion.

[0019] In an optional embodiment of this application, the inner sealing part is bonded or vulcanized to the outer sealing part.

[0020] In an optional embodiment of this application, a sealing reinforcement is formed on the surface of the inner sealing portion, and the sealing reinforcement has an uneven surface.

[0021] According to another aspect of this application, an electrolytic cell is provided, which includes a plurality of stacked electrode frames and the sealing gaskets described above, the sealing gaskets being disposed between two adjacent electrode frames.

[0022] In summary, the sealing gasket and electrolytic cell provided in this application have at least the following beneficial effects:

[0023] In this application, since the rebound rate of the inner sealing part of the sealing gasket is set to be greater than that of the outer sealing part, and the compressive stress of the outer sealing part is set to be greater than that of the inner sealing part, when the sealing gasket is clamped and fixed by two adjacent pole frames, the inner sealing part can provide sufficient sealing capacity at the inner sealing position to better seal the flow channel holes of the pole frame and key positions such as the vicinity of the diaphragm, while the outer sealing part can have sufficient support strength at the outer sealing position to ensure the gap of the electrolysis chamber. Thus, the sealing gasket of this application can simultaneously meet the sealing capacity and support strength requirements at different positions between pole frames.

[0024] Furthermore, in this application, the rebound rate and compressive stress of the outer and inner sealing parts are designed differently. This allows for complementary advantages between the two parts, avoiding the problems of insufficient support strength while ensuring sealing performance, and insufficient sealing capacity while ensuring support strength, that arise with gaskets made of uniform materials. In addition, since the outer sealing part of this application provides sufficient support strength to support the weight of large electrolytic cells, the sealing gasket of this application is also suitable for use in large electrolytic cells. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this application, the accompanying drawings used in the specific embodiments will be briefly described below. Obviously, the drawings described below are some embodiments of this application; those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0026] Figure 1 is a partial structural schematic diagram of the electrolytic cell provided in the embodiment of this application;

[0027] Figure 2 is a schematic diagram of the structure of the sealing gasket provided in the embodiment of this application.

[0028] The reference numerals in the attached drawings are as follows: 100, sealing gasket; 10, outer sealing part; 20, inner sealing part; 21, sealing reinforcement part; A, hollow structure; T, flow channel hole; 200, pole frame. Detailed Implementation

[0029] To make the above and other features and advantages of this application clearer, the application is further described below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explanation to those skilled in the art and are exemplary only, not restrictive.

[0030] In the description of this application, features specified with "first" or "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features specified with "first" or "second" may explicitly or implicitly include at least one of the specified features. The use of the term "multiple" generally means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] In this application, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can be a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] In the description of this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0033] Figure 1 is a partial structural schematic diagram of the electrolytic cell provided in an embodiment of this application.

[0034] Please refer to Figure 1. The electrolytic cell provided in this embodiment includes a plurality of stacked electrode frames 200 and a sealing gasket 100 disposed between two adjacent electrode frames 200.

[0035] A diaphragm 300 is provided between every two adjacent electrode frames 200. In the electrolytic cell installation state, every two adjacent electrode frames 200 and the diaphragm 300 between them form an electrolytic cell. The electrolytic cell includes an anode cell and a cathode cell separated by the diaphragm 300. The sealing gasket 100 located between the two adjacent electrode frames 200 is used to seal and isolate the anode cell and the cathode cell.

[0036] Each electrode frame 200 is provided with a channel hole for conveying electrolyte. Specifically, for any given electrode frame 200, it receives electrolyte from an adjacent electrode frame 200 through its channel hole and conveys electrolyte radially to its corresponding electrolytic chamber. Simultaneously, the electrode frame 200 also conveys electrolyte axially to another adjacent electrode frame 200 through its channel hole, thereby achieving electrolyte distribution along the length of the electrolytic cell. The length of the electrolytic cell is defined as the thickness direction of the electrode frame 200 (i.e., the axial direction of the channel hole).

[0037] Figure 2 is a schematic diagram of the structure of the sealing gasket provided in the embodiment of this application.

[0038] Referring to Figures 1 and 2, the sealing gasket 100 provided in this embodiment includes an outer sealing portion 10 and an inner sealing portion 20. The outer sealing portion 10 has a hollow structure A, and at least a portion of the inner sealing portion 20 is disposed within the hollow structure A of the outer sealing portion 10. Specifically, the inner sealing portion 20 may be partially disposed within the hollow structure A of the outer sealing portion 10, or it may be entirely disposed within the hollow structure A of the outer sealing portion 10; this application does not impose specific limitations.

[0039] When the electrolytic cell is installed, the inner sealing part 20 is closer to the electrolysis chamber, while the outer sealing part 10 is farther away from the electrolysis chamber. That is, the inner sealing part 20 is located in the inner sealing position between the electrode frames 200 (such as the flow channel holes of the electrode frames 200 and the vicinity of the diaphragm 300, etc.), and the outer sealing part 10 is located in the outer sealing position between the electrode frames 200 (such as the position away from the flow channel holes of the electrode frames 200 and the diaphragm 300).

[0040] In addition, in order to realize the delivery of electrolyte, the inner sealing part 20 is provided with a flow channel hole T through it along its thickness direction, and the flow channel hole T is provided corresponding to the channel hole on the electrode frame 200.

[0041] Based on the positional difference between the inner and outer sealing positions, the rebound rate of the inner sealing part 20 corresponding to the inner sealing position is greater than that of the outer sealing part 10, while the compressive stress of the outer sealing part 10 corresponding to the outer sealing position is greater than that of the inner sealing part 20.

[0042] It should be noted that the higher the rebound rate of an object, the better its sealing ability (or material), while the higher the compressive stress of an object, the stronger its ability to resist compression under external force, that is, the stronger its support strength and load-bearing capacity.

[0043] In this embodiment, since the rebound rate of the inner sealing part 20 of the sealing gasket 100 is set to be greater than that of the outer sealing part 10 and the compressive stress of the outer sealing part 10 is set to be greater than that of the inner sealing part 20, when the sealing gasket 100 is clamped and fixed by two adjacent pole frames 200, the inner sealing part 20 can provide sufficient sealing capacity at the inner sealing position to better seal the flow channel holes of the pole frame 200 and key positions such as near the diaphragm 300, while the outer sealing part 10 can have sufficient support strength and load-bearing capacity at the outer sealing position to ensure the gap of the electrolysis chamber. Thus, the sealing gasket 100 of this application can simultaneously meet the sealing capacity and support strength requirements at different positions between the pole frames 200.

[0044] Since the resilience and compressive stress of a homogeneous material gasket are consistent regardless of whether it corresponds to the inner or outer sealing position, if the homogeneous material gasket can guarantee sufficient sealing performance at the inner sealing position, it is prone to support failure at the outer sealing position due to insufficient support strength. Conversely, if the homogeneous material gasket can guarantee sufficient support strength at the outer sealing position, it is prone to sealing failure at the inner sealing position. In this embodiment, by differentiating the resilience and compressive stress of the outer sealing portion 10 and the inner sealing portion 20 of the sealing gasket 100, the two portions can complement each other, thereby avoiding the problems of insufficient support strength while ensuring sealing performance and insufficient sealing capacity while ensuring support strength of the homogeneous material gasket.

[0045] Furthermore, since the outer sealing portion 10 of the sealing gasket 100 of this application can provide sufficient support strength to support the weight of a large electrolytic cell, the sealing gasket 100 of this application can also be used in large electrolytic cells.

[0046] In some embodiments, the resilience of the inner sealing portion 20 of the sealing gasket 100 is 50%-100%, and the compressive stress of the inner sealing portion 20 is 1MPa-25MPa. For example, the resilience of the inner sealing portion 20 can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or other resilience values ​​within the range of 50%-100%, and the compressive stress of the inner sealing portion 20 can be 1MPa, 5MPa, 8MPa, 10MPa, 12MPa, 15MPa, 18MPa, 20MPa, 22MPa, 25MPa, or other compressive stress values ​​within the range of 1MPa-25MPa.

[0047] Since the rebound rate of the inner sealing part 20 of the sealing gasket 100 in this application is 50%-100% and the compressive stress of the inner sealing part 20 is 1MPa-25MPa, the inner sealing part 20 has high compression and large rebound during use, which can provide sufficient sealing capacity. Moreover, its sealing capacity is not easily reduced during long-term use and it is not prone to problems such as loosening failure. It is especially suitable for green electricity and green hydrogen working conditions.

[0048] In some embodiments, the resilience of the outer sealing portion 10 of the sealing gasket 100 is 2% to 85%, and the compressive stress of the outer sealing portion 10 is 8 MPa to 100 MPa. For example, the resilience of the outer sealing portion 10 can be 2%, 10%, 15%, 20%, 25%, 35%, 40%, 45%, 50%, 60%, 70%, 80%, 85%, or other resilience values ​​within the range of 2% to 85%, and the compressive stress of the outer sealing portion 10 can be 8 MPa, 15 MPa, 25 MPa, 30 MPa, 40 MPa, 50 MPa, 60 MPa, 70 MPa, 80 MPa, 90 MPa, 100 MPa, or other compressive stress values ​​within the range of 8 MPa to 100 MPa.

[0049] Since the outer sealing part 10 of the sealing gasket 100 in this application has a resilience rate of 2% to 85% and a compressive stress of 8MPa to 100MPa, the outer sealing part 10 can not only play a sealing and insulating role during use, but also withstand a large weight of the electrolytic cell. Moreover, the outer sealing part 10 is not prone to support failure during long-term use, thereby maintaining the gap between the electrolytic cells.

[0050] It should be noted that the rebound rate of the inner sealing part 20 and the rebound rate of the outer sealing part 10 are both measured based on the test standard GB / T 12622-2008, while the compressive stress of the inner sealing part 20 and the compressive stress of the outer sealing part 10 are both measured based on the test standard GB / T 1041-2008 and under the condition that the sealing gasket 100 is under a 25% compression rate.

[0051] In some embodiments, the compressive settling rate of the inner sealing portion 20 is less than that of the outer sealing portion 10. The compressive settling rate is an important indicator for measuring the residual deformation of an object (or material) under compressive load, reflecting the degree of residual deformation after the external force is removed. Generally, a smaller compressive settling rate indicates stronger resilience and resistance to deformation of the object.

[0052] Therefore, this application sets the compression set of the inner sealing part 20 to be less than that of the outer sealing part 10, which can ensure that the rebound and deformation resistance of the inner sealing part 20 are stronger than those of the outer sealing part 10, thereby ensuring that the sealing ability of the inner sealing part 20 is not easily weakened during long-term use and is not prone to problems such as loosening failure.

[0053] In some embodiments, the compression set of the inner seal 20 is not higher than 60%. For example, the compression set of the inner seal 20 can be 10%, 20%, 30%, 35%, 38%, 40%, 45%, 48%, 50%, 55%, 58%, 60%, or other compression set values ​​in the range of 10%-60%.

[0054] This application controls the compression set rate of the inner sealing part 20 within the above-mentioned range, which can ensure that the inner sealing part 20 has sufficient resilience and anti-deformation ability. As a result, the inner sealing part 20 can not only provide sufficient sealing ability at the inner sealing position, but also its sealing ability is not easily reduced during long-term use, and it is not easy to have problems such as loosening failure.

[0055] Preferably, the compression set of the inner seal 20 is not higher than 30%. For example, the compression set of the inner seal 20 can be 2%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, or other compression set values ​​in the range of 2%-30%.

[0056] This design allows the inner sealing part 20 to have excellent resilience and resistance to deformation, so that its sealing ability is not easily weakened during long-term use and it is not prone to loosening and failure, thus ensuring the sealing performance and stability of the sealing gasket 100 during long-term use.

[0057] In some embodiments, the compression set of the outer seal 10 is 40%-95%. For example, the compression set of the outer seal 10 can be 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or other compression set values ​​within the range of 40%-95%.

[0058] This application controls the compression set of the outer sealing part 10 within the above-mentioned range, which ensures that the outer sealing part 10 has sufficient support strength, as well as a certain degree of resilience and anti-deformation ability. Thus, the outer sealing part 10 can not only maintain the gap of the electrolysis chamber at the outer sealing position, but also provide a certain sealing effect. Therefore, when used in conjunction with the inner sealing part 20, it greatly improves the sealing performance and support performance of the sealing gasket 100 during long-term use, and reduces the probability of support failure at the outer sealing position and sealing failure at the inner sealing position.

[0059] It should be noted that the compression set rate of the inner sealing part 20 and the compression set rate of the outer sealing part 10 are both measured based on the test standard GB / T 1041-2008 and under the conditions of the sealing gasket 100 being at a compression rate of 25%, 100°C and maintained for 100 hours.

[0060] In some embodiments, the creep relaxation rate of the inner seal 20 is 2% to 50%. For example, the creep relaxation rate of the inner seal 20 can be 2%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or other creep relaxation rate values ​​within the range of 2% to 50%.

[0061] The creep relaxation rate reflects the ability of the sealing material to resist stress relaxation and deformation. If the creep relaxation rate of the inner sealing part 20 is set to 2% to 50%, the inner sealing part 20 will have sufficient ability to resist stress relaxation and deformation, thereby enabling the inner sealing part 20 to maintain stable sealing ability during long-term use and reducing the probability of relaxation failure.

[0062] In some embodiments, the creep relaxation rate of the outer sealing portion 10 is 5% to 70%. For example, the creep relaxation rate of the outer sealing portion 10 can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or other creep relaxation rate values ​​within the range of 5% to 70%.

[0063] By setting the creep relaxation rate of the outer sealing part 10 to 5% to 70%, the outer sealing part 10 has a certain ability to resist stress relaxation and deformation, thereby enabling the outer sealing part 10 to maintain stable support capacity during long-term use and reducing the probability of support failure.

[0064] It should be noted that the creep relaxation rate of the inner sealing part 20 and the creep relaxation rate of the outer sealing part 10 are both measured based on the test standard GB / T 20671.5-2020 and under the condition that the sealing gasket 100 is at room temperature for 24 hours.

[0065] In some embodiments, the compression rate of the outer seal 10 is 2% to 50%. For example, the compression rate of the outer seal 10 can be 2%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or other compression rate values ​​within the range of 2% to 50%.

[0066] By setting the compression rate of the outer sealing part 10 to 2% to 50%, the outer sealing part 10 has a certain compression deformation capacity, thereby providing a certain sealing performance at the outer sealing position. Even if the inner sealing part 20 fails to seal, the sealing gasket 100 still has the ability to seal and isolate the anode chamber and the cathode chamber based on the presence of the outer sealing part 10.

[0067] It should be noted that the compression ratio of the outer sealing part 10 is based on the test standard GB / T 12622-2008 and is measured under the condition that the sealing gasket 100 is at room temperature for 24 hours.

[0068] In some embodiments, the outer sealing portion 10 is made of a mixture of polytetrafluoroethylene (PTFE) and a filler. The filler may include at least one of glass fiber, carbon fiber, barium sulfate, carbon powder, quartz powder, molybdenum disulfide, graphite powder, and polyimide.

[0069] Since PTFE is a special engineering material, it has the characteristics of high decomposition temperature, low brittle temperature and strong alkali resistance. Therefore, the outer sealing part 10 made of PTFE containing filler (which can be called modified PTFE) can have greater support strength and can play the roles of insulation, ensuring the gap of electrolysis chamber, and bearing weight. In particular, it is not easy to have support failure during long-term use, thus meeting the support strength requirements of the outer sealing position and being able to support the weight of large electrolytic cells.

[0070] In some embodiments, the inner sealing portion 20 is made of rubber. The rubber material includes at least one of ethylene propylene rubber, fluororubber, silicone rubber, ethylene-vinyl acetate copolymer rubber, and thermoplastic elastomers.

[0071] Because rubber materials have excellent resistance to weathering, heat and oxygen, and strong alkalis, the inner sealing part 20 made of rubber materials can have high compression and high resilience, and its sealing performance is excellent. Moreover, the sealing capacity decays slowly during long-term use and is not prone to loosening and failure, thus meeting the sealing capacity requirements of the inner sealing position.

[0072] Therefore, based on the different inner and outer sealing positions, this application uses PTFE material to make the outer sealing part 10 and rubber material to make the inner sealing part 20, thereby meeting the sealing capacity and support strength requirements of different positions between the pole frames 200.

[0073] In some embodiments, the thickness of the outer sealing portion 10 is d1, and the thickness of the inner sealing portion 20 is d2, where d2 = (70% to 110%)d1. For example, d2 can be 70%d1, 75%d1, 80%d1, 85%d1, 90%d1, 95%d1, 100%d1, 105%d1, 110%d1, or other values ​​within the range of (70% to 110%)d1.

[0074] In this application, by setting the thickness of the outer sealing part 10 and the thickness of the inner sealing part 20 to satisfy the above relationship, it is possible to avoid the problems of the pole frame 200 tilting due to the inner sealing part 20 being too thick relative to the outer sealing part 10, which would affect the assembly, and the sealing gasket 100 being damaged due to excessive pressure on the bottom gasket part when tightening the bolts. It is also possible to avoid the problems of the pole frame 200 tilting easily when tightening the bolts due to the outer sealing part 10 being too thick relative to the inner sealing part 20, and the sealing problems of key positions such as the flow channel hole and diaphragm 300 caused by insufficient deformation of the inner sealing part 20.

[0075] This is because when d2 > 110%d1, the inner sealing part 20 is much thicker than the outer sealing part 10. As a result, the compressive stress of the inner sealing part 20 is smaller. During the assembly of the electrolytic cell, the inner sealing part 20 will contact the electrode frame 200 first. The inner sealing part 20 is prone to deformation, which will cause the electrode frame 200 to tilt, thus affecting the assembly. At the same time, during the assembly of the electrolytic cell, the bottom gasket part of the sealing gasket 100 will deform more under the influence of gravity than the upper gasket part in the direction of gravity of the electrolytic cell. When tightening the bolts, the bottom gasket part is prone to overpressure damage to the sealing gasket 100.

[0076] When d2 < 70% d1, the outer sealing part 10 is much thicker than the inner sealing part 20. Due to the poor resilience and high creep rate of the outer sealing part 10, the pole frame 200 is easily tilted when the bolts are tightened. Moreover, the required tightening compression stroke is large, which can easily cause insufficient deformation of the inner sealing part 20, thereby affecting the sealing performance of key positions such as the flow channel hole and the diaphragm 300.

[0077] In some embodiments, the width of the outer sealing portion 10 is 5 mm to 200 mm, and the thickness of the outer sealing portion 10 is 0.1 mm to 50 mm. For example, the width of the outer sealing portion 10 can be 5 mm, 20 mm, 40 mm, 60 mm, 80 mm, 100 mm, 120 mm, 140 mm, 150 mm, 180 mm, 200 mm, or other width values ​​within the range of 5 mm to 200 mm, and the thickness of the outer sealing portion 10 can be 0.1 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, or other thickness values ​​within the range of 0.1 mm to 50 mm.

[0078] Taking the annular sealing gasket 100 as an example, the width of the outer sealing part 10 refers to the radial dimension of the outer sealing part 10 in the sealing gasket 100, while the thickness of the outer sealing part 10 refers to the axial dimension of the outer sealing part 10 in the sealing gasket 100.

[0079] In some embodiments, the width of the inner sealing portion 20 is 5 mm to 200 mm, and the thickness of the inner sealing portion 20 is 0.1 mm to 50 mm. For example, the width of the inner sealing portion 20 can be 5 mm, 20 mm, 40 mm, 60 mm, 80 mm, 100 mm, 120 mm, 140 mm, 150 mm, 180 mm, 200 mm, or other width values ​​within the range of 5 mm to 200 mm, and the thickness of the inner sealing portion 20 can be 0.1 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, or other width values ​​within the range of 0.1 mm to 50 mm.

[0080] In some embodiments, at least one of the inner sealing portion 20 and the outer sealing portion 10 is partially overlapped on the other (i.e., overlapped connection) or embedded in the other (i.e., embedded connection) to connect the inner sealing portion 20 and the outer sealing portion 10, that is, the inner sealing portion 20 and the outer sealing portion 10 are separately provided and connected as one.

[0081] Here, "overlapping" means that the inner sealing part 20 and the outer sealing part 10 have overlapping portions in the thickness direction of the sealing gasket 100, while "embedded" means that the inner sealing part 20 and the outer sealing part 10 have portions that are inserted into the other in the radial direction of the sealing gasket 100.

[0082] Understandably, in order to achieve the connection between the inner sealing part 20 and the outer sealing part 10, a portion of the inner sealing part 20 may overlap with the outer sealing part 10, a portion of the outer sealing part 10 may overlap with the inner sealing part 20, or a portion of the inner sealing part 20 may overlap with the outer sealing part 10 and a portion of the outer sealing part 10 may overlap with the inner sealing part 20 (i.e., they overlap with each other), and a portion of the inner sealing part 20 may be embedded in the outer sealing part 10, a portion of the outer sealing part 10 may be embedded in the inner sealing part 20, or a portion of the inner sealing part 20 may be embedded in the outer sealing part 10 and a portion of the outer sealing part 10 may be embedded in the inner sealing part 20 (i.e., they embed with each other). By connecting the inner sealing part 20 with the outer sealing part 10, a continuous and gapless seal can be formed at the junction of the inner sealing part 20 and the outer sealing part 10 after the electrolytic cell assembly is completed. This eliminates the leakage path of electrolyte at the junction of the inner sealing part 20 and the outer sealing part 10, avoids the risk of short circuit and arcing between adjacent electrode frames 200, and improves the safety of the electrolytic cell.

[0083] In some embodiments, the length of the connection portion between the inner sealing portion 20 and the outer sealing portion 10 does not exceed 20% of the width of either the inner sealing portion 20 or the outer sealing portion 10. Specifically, when the inner sealing portion 20 and the outer sealing portion 10 are connected in an overlapping manner, the length of the connection portion refers to the overlap length of the overlapping portion; when the inner sealing portion 20 and the outer sealing portion 10 are connected in an embedded manner, the length of the connection portion refers to the embedding depth of the embedded portion.

[0084] In this embodiment, the length of the connection portion between the inner sealing part 20 and the outer sealing part 10 is set to not exceed 20% of the width of either the inner sealing part 20 or the outer sealing part 10. This setting can avoid the problem of peeling and delamination at the interface after compression due to the difference in the resilience and compressive stress between the inner sealing part 20 and the outer sealing part 10, thereby ensuring the sealing and load-bearing capacity of the electrolytic cell.

[0085] In some embodiments, the inner sealing part 20 can be connected to the outer sealing part 10 by bonding or vulcanization. Specifically, bonding or vulcanization can be performed at the overlap position of the inner sealing part 20 and the outer sealing part 10 to connect the inner sealing part 20 and the outer sealing part 10 in an overlapping manner; alternatively, vulcanization can be used to embed at least one part of the inner sealing part 20 and the outer sealing part 10 into the other to connect the inner sealing part 20 and the outer sealing part 10 in an embedded manner. By connecting the inner sealing part 20 and the outer sealing part 10 into a whole, the risk of misalignment or separation of the inner sealing part 20 and the outer sealing part 10 due to uneven pressure on the sealing gasket, vibration of the electrolytic cell, or thermal expansion and contraction can be prevented during installation, transportation, and operation. At the same time, installing the inner sealing part 20 and the outer sealing part 10 as a whole component can simplify the assembly process, reduce the risk of installation errors (such as omissions, incorrect placement, or misalignment), and improve production efficiency and the consistency of assembly quality.

[0086] In cases where at least one of the inner sealing portion 20 and the outer sealing portion 10 is partially embedded in the other, in order to improve the bonding strength between the inner sealing portion 20 and the outer sealing portion 10 at the connection position, a tenon structure, a snap-fit ​​structure, a serrated structure, a stepped structure, etc., can be formed at the connection position for them to fit and bond together.

[0087] In some embodiments, to further improve the internal sealing performance, a sealing reinforcement 21 is formed on the surface of the internal sealing portion 20. The sealing reinforcement 21 has an uneven surface, such as a step, a ridge, or a groove. Specifically, the cross-sectional shape of the ridge and groove on the surface of the internal sealing portion 20 can be dovetail-shaped, trapezoidal, circular, elliptical, wavy, etc. When the electrolytic cell is assembled or in operation, the diaphragm 300 is fixed between the internal sealing portion 20 and the electrode frame 200. The sealing reinforcement 21 on the surface of the internal sealing portion 20 undergoes elastic deformation under pressure and abuts against the diaphragm 300 or the electrode frame 200. While fixing the installation position of the diaphragm 300, the sealing effect can be further improved.

[0088] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A gasket (100), wherein, Applications in electrolytic cells, including: The outer sealing part (10) has a hollow structure (A); and An inner sealing portion (20) is at least partially disposed within the hollow structure (A); The rebound rate of the inner sealing part (20) is greater than that of the outer sealing part (10), and the compressive stress of the outer sealing part (10) is greater than that of the inner sealing part (20).

2. The sealing gasket (100) according to claim 1, wherein, The inner sealing part (20) has a resilience of 50% to 100% and a compressive stress of 1 MPa to 25 MPa; and / or The outer sealing part (10) has a resilience of 2% to 85% and a compressive stress of 8 MPa to 100 MPa.

3. The gasket (100) of claim 1 or 2, wherein, The compression set of the inner sealing part (20) is less than that of the outer sealing part (10).

4. The sealing gasket (100) according to claim 3, wherein, The compression set of the inner sealing part (20) is not higher than 60%, and the creep relaxation rate is 2% to 50%. Preferably, the compression set of the inner sealing part (20) is not higher than 30%; and / or The outer sealing part (10) has a compression set of 40%-95%, a compression ratio of 2%-50%, and a creep relaxation rate of 5%-70%.

5. The sealing gasket (100) according to any one of claims 1-4, wherein, The thickness of the outer sealing part (10) is d1, and the thickness of the inner sealing part (20) is d2, where d2 = (70% to 110%)d1; and / or The width of the outer sealing part (10) is 5mm to 200mm, and the thickness of the outer sealing part (10) is 0.1mm to 50mm; and / or The width of the inner sealing part (20) is 5mm to 200mm, and the thickness of the inner sealing part (20) is 0.1mm to 50mm.

6. The sealing gasket (100) according to any one of claims 1-5, wherein, The outer sealing part (10) is made of a mixture of polytetrafluoroethylene and filler, wherein the filler includes at least one of glass fiber, carbon fiber, barium sulfate, carbon powder, quartz powder, molybdenum disulfide, graphite powder and polyimide; The inner sealing part (20) is made of rubber material, which includes at least one of ethylene propylene rubber, fluororubber, silicone rubber, ethylene-vinyl acetate copolymer rubber, and thermoplastic elastomer.

7. The gasket (100) of any one of claims 1-6, wherein, At least one of the inner sealing portion (20) and the outer sealing portion (10) overlaps or is embedded in the other to connect the inner sealing portion (20) and the outer sealing portion (10).

8. The sealing gasket (100) according to claim 7, wherein, The length of the connection portion between the inner sealing part (20) and the outer sealing part (10) does not exceed 20% of the width of either the inner sealing part (20) or the outer sealing part (10); and / or The inner sealing part (20) is bonded or vulcanized to the outer sealing part (10).

9. The gasket (100) of any one of claims 1-8, wherein, A sealing reinforcement (21) is formed on the surface of the inner sealing part (20), and the sealing reinforcement (21) has an uneven surface.

10. An electrolytic cell wherein, It includes a plurality of stacked pole frames (200) and a sealing gasket (100) according to any one of claims 1-9, the sealing gasket (100) being disposed between two adjacent pole frames (200).

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