Sealing member, water electrolysis stack comprising same, and fuel cell comprising same

Abstract

The present invention provides a sealing member for a water electrolysis stack or a fuel cell. The sealing member comprises: a substrate, which is flake-like and comprises a first surface and a second surface which are arranged opposite to each other in the thickness direction of the substrate; and a covering layer, which has a wavy surface and is at least partially laid on the first surface and the second surface of the substrate, wherein the covering layer comprises an elastic compressible material and is provided with a plurality of protruding parts which are arranged at intervals in a first direction, the first direction is orthogonal to the thickness direction, and in the first direction, at least some of the protruding parts arranged on the first surface and at least some of the protruding parts arranged on the second surface are arranged in a staggered mode. The present invention further provides a water electrolysis stack comprising the sealing member, and a fuel cell comprising the sealing member.

Description

Seal, water electrolysis stack and fuel cell including seal Technical Field

[0001] The present invention relates to the field of hydrogen energy technology, and in particular to a seal for a water electrolysis stack or a fuel cell, a water electrolysis stack including the seal, and a fuel cell including the seal. Background Art

[0002] As a new energy source, hydrogen energy is environmentally friendly and highly efficient. Therefore, hydrogen-based fuel cell stacks are gaining increasing attention. These stacks can be used in both water electrolysis stacks and fuel cells (such as hydrogen fuel cells, flow batteries, and similar batteries). Water electrolysis stacks can be used to produce hydrogen by electrolyzing water to form oxygen and hydrogen, while fuel cells convert the chemical energy of hydrogen and oxygen into water by combining oxygen and hydrogen, thereby directly converting the chemical energy of hydrogen and oxygen into electrical energy.

[0003] Both devices require seals to seal oxygen and hydrogen. However, in existing technologies, the large number of components in a fuel cell stack results in large cumulative tolerances during assembly. Furthermore, the thinness of existing seals and the limited installation space can easily lead to seal failure, potentially causing the oxygen and hydrogen to mix and cause a small explosion.

[0004] Therefore, there is an urgent need for a seal with good sealing performance to improve the safety of water electrolysis stacks or fuel cells.

[0005] Summary of the Invention

[0006] The present invention aims to provide a seal for a water electrolysis stack or a fuel cell, wherein the seal has good sealing performance, a stable structure, and a long service life. Another object of the present invention is to provide a water electrolysis stack including such a seal and a fuel cell including such a seal.

[0007] In a first aspect, an embodiment of the present invention provides a seal for a water electrolysis stack or a fuel cell, comprising: a substrate, which is sheet-shaped and includes a first surface and a second surface arranged opposite to each other along its thickness direction; and a covering layer, which has a wavy surface and is at least partially covered on the first surface and the second surface of the substrate, the covering layer comprising an elastic compressible material and having a plurality of raised portions spaced apart along a first direction, the first direction being orthogonal to the thickness direction; in the first direction, at least a portion of the raised portions arranged on the first surface is staggered with at least a portion of the raised portions arranged on the second surface.

[0008] In a preferred embodiment of the present invention, each of the plurality of protrusions spaced apart in the first direction extends in a second direction, and the second direction is orthogonal to both the first direction and the thickness direction.

[0009] In a preferred embodiment of the present invention, the protrusions provided on the first surface and the protrusions provided on the second surface extend in the same direction.

[0010] In a preferred embodiment of the present invention, the cross sections of the same protrusions in their extending directions are the same.

[0011] In a preferred embodiment of the present invention, the cover layer completely covers the base body.

[0012] In a preferred embodiment of the present invention, the sealing member is formed in a flat ring shape and includes an outer ring surface and an inner ring surface that are oppositely disposed.

[0013] In a preferred embodiment of the present invention, in the thickness direction, the raised portion provided on the first surface close to the outer annular surface at least partially overlaps with the raised portion provided on the second surface close to the outer annular surface; and / or in the thickness direction, the raised portion provided on the first surface close to the inner annular surface at least partially overlaps with the raised portion provided on the second surface close to the inner annular surface.

[0014] In a preferred embodiment of the present invention, in the thickness direction, the maximum thickness position of the raised portion arranged on the first surface close to the outer annular surface is substantially aligned with the maximum thickness position of the raised portion arranged on the second surface close to the outer annular surface; and / or in the thickness direction, the maximum thickness position of the raised portion arranged on the first surface close to the inner annular surface is substantially aligned with the maximum thickness position of the raised portion arranged on the second surface close to the inner annular surface.

[0015] In a preferred embodiment of the present invention, each protrusion at least partially extends around the circumference of the annular base.

[0016] In a preferred embodiment of the invention, the base body comprises a material having a higher hardness than the elastically compressible material of the cover layer.

[0017] In a preferred embodiment of the present invention, the covering layer is directly attached to the base body and is fixedly connected to the base body.

[0018] In the second aspect, an embodiment of the present invention further provides a water electrolysis stack, comprising a cathode assembly, a catalyst coating membrane and an anode assembly stacked in sequence up and down, wherein the water electrolysis stack also includes the above-mentioned seal, which is clamped between the cathode assembly and the catalyst coating for sealing the reaction zone of the water electrolysis stack, the thickness direction of the seal corresponds to the stacking direction of the cathode assembly, the catalyst coating membrane and the anode assembly, and the raised portion of the seal is arranged in a manner that at least partially surrounds the periphery of the reaction zone.

[0019] In the third aspect, an embodiment of the present invention also provides a fuel cell, comprising a cathode assembly, a catalyst coating membrane and an anode assembly stacked in sequence up and down, wherein the fuel cell also includes the above-mentioned seal, which is clamped between the cathode assembly and the catalyst coating for sealing the reaction zone of the fuel cell, the thickness direction of the seal corresponds to the stacking direction of the cathode assembly, the catalyst coating membrane and the anode assembly, and the raised portion of the seal is arranged in a manner that at least partially surrounds the periphery of the reaction zone.

[0020] The seal according to the present invention includes a base and a covering layer laid on the surface of the base. By making the surface of the covering layer wavy, when the seal is subjected to an external force perpendicular to its thickness direction, the raised portions on the upper surface and the raised portions on the lower surface will be squeezed to deform the base into a wavy shape. As a result, the base will provide supporting force to the covering layer like a spring, so that the entire seal has higher sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0022] FIG1 shows an overall schematic diagram of a fuel cell stack device according to the present invention;

[0023] FIG2 shows a cross-sectional view of a partial structure of a stack unit according to the present invention;

[0024] FIG3 shows a schematic top view of a sealing member according to a first embodiment of the present invention;

[0025] FIG4 shows a schematic cross-sectional view of portion A in FIG3 ;

[0026] FIG5 is a schematic diagram showing the installation position of a sealing member in a fuel cell stack unit according to the first embodiment of the present invention;

[0027] FIG6 shows a schematic top view of a sealing member according to a second embodiment of the present invention;

[0028] FIG. 7 is a schematic cross-sectional view of portion B in FIG. 6 .

[0029] FIG8 is a schematic diagram showing the installation position of a sealing member in a fuel cell stack unit according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0031] In the description of this application, unless otherwise specified, the terms "upper," "lower," "inner," "outer," etc., indicating directions or positional relationships, are intended only to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The directional terms appearing in the following description refer to the directions shown in the drawings and are not intended to limit the specific structure of this application.

[0032] It should also be noted that, in the description of this application, unless otherwise specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0033] Figure 1 shows a battery stack device 100 according to an embodiment of the present invention, which includes two end plates 11 and 12 spaced apart from each other, and at least one battery stack unit 10 sandwiched between the two end plates 11 and 12. The two end plates 11 and 12 are fixedly connected by a plurality of fasteners (such as a plurality of locating pins or a plurality of bolts, etc.), thereby clamping the at least one battery stack unit 10 located therebetween. In the case where the battery stack device 100 includes a plurality of battery stack units 10, the plurality of battery stack units 10 are stacked on each other between the two end plates 11 and 12. Of course, the present invention is not limited to this, and the number of battery stack units 10 disposed between the two end plates 11 and 12 may be only one.

[0034] FIG2 shows a cross-sectional view of a portion of the structure of a stack unit 10 of a stack device 100 according to an embodiment of the present invention. The following description with reference to FIG2 is based on an example of a stack device according to an embodiment of the present invention being applied to a water electrolysis stack. However, those skilled in the art will appreciate that the stack device according to an embodiment of the present invention may also be applied to a fuel cell.

[0035] As shown in Figure 2, each stack unit 10 includes a catalyst coating membrane 13 (referred to as CCM), a cathode assembly and an anode assembly. The cathode assembly and the anode assembly are respectively arranged on opposite sides of the catalyst coating membrane 13. For example, the cathode assembly is arranged on the cathode side of the catalyst coating membrane 13 (i.e., the upper side in Figure 2), and the anode assembly is arranged on the anode side of the catalyst coating membrane 13 (i.e., the lower side in Figure 2). Thus, in the case where the stack device 100 includes only one stack unit 10, the cathode assembly and the anode assembly of the one stack unit 10 are respectively against the two end plates 11 and 12. In the case where the stack device 100 includes multiple stack units 10, except for the two stack units 10 that are closest to the two end plates 11 and 12, the cathode assembly of each stack unit 10 is adjacent to the anode assembly of the adjacent stack unit 10, and the anode assembly of one stack unit 10 is adjacent to the cathode assembly of another adjacent stack unit 10.

[0036] Each stack unit 10 also includes a mounting frame 14 for mounting and supporting the catalyst coating membrane 13, the cathode assembly, and the anode assembly. In an exemplary embodiment, the mounting frame 14 includes a support portion 14A and a peripheral portion 14B that are connected to each other. The peripheral portion 14B is arranged around the peripheral side of the support portion 14A. The thickness of the support portion 14A is less than the thickness of the peripheral portion 14B, thereby forming a step between the support portion 14A and the peripheral portion 14B, so that the peripheral portion of the catalyst coating membrane 13 can be placed and supported on the support portion 14A of the mounting frame 14, while the peripheral portion 14B of the mounting frame 14 is arranged around the entire catalyst coating membrane 13. Exemplarily, the support portion 14A and the peripheral portion 14B can be formed integrally.

[0037] The catalyst coating membrane 13 includes a proton exchange membrane, a cathode catalyst layer (not shown) coated on the cathode side of the proton exchange membrane, and an anode catalyst layer (not shown) coated on the anode side of the proton exchange membrane. The cathode catalyst layer and the anode catalyst layer can be directly coated on opposite sides of the proton exchange membrane by, for example, slot coating. This coating method is simple, requires minimal equipment, has simple operation steps, and can effectively improve catalyst utilization.

[0038] The cathode assembly is disposed on the cathode side (upper side in FIG. 2 ) of the catalyst coated membrane 13 and includes components such as a cathode diffusion layer 15, a cathode support plate 16, a cathode support ring 17, and a cathode plate 18. The cathode diffusion layer 15, cathode support plate 16, and cathode support ring 17, along with the catalyst coated membrane 13, are housed within a space enclosed by the outer periphery 14B of the mounting frame 14. Specifically, the outer periphery 14B of the mounting frame 14 surrounds the outer periphery of each of the catalyst coated membrane 13, the cathode diffusion layer 15, the cathode support plate 16, and the cathode support ring 17.

[0039] The cathode diffusion layer 15 is arranged close to the cathode catalyst layer. The cathode diffusion layer 15 can be made of materials such as porous titanium, carbon cloth, carbon paper, etc., which play the role of conducting electricity and transmitting water and hydrogen. As shown in Figure 2, the cathode support plate 16 is arranged on the side of the cathode diffusion layer 15 away from the catalyst coating membrane 13 to support the cathode diffusion layer 15. In addition, the cathode support plate 16 can also include a plurality of micropores to further serve the purpose of transporting water and hydrogen. The cathode support plate 16 can be processed by corrosion-resistant materials such as stainless steel (for example, iron). The cathode support ring 17 is annular and is arranged between the outer peripheral portion 14B of the mounting frame 14 and the cathode diffusion layer 15 and the cathode support plate 16, that is, the cathode support ring 17 is arranged around the outer periphery of the cathode diffusion layer 15 and the cathode support plate 16. The cathode support ring 17 is disposed between the catalyst coated membrane 13 and the cathode plate 18 along the stacking direction Y (i.e., the vertical direction in the figure) of the catalyst coated membrane 13, cathode assembly, and anode assembly. Specifically, the lower surface of the cathode support ring 17, which is adjacent to the cathode diffusion layer 15, at least partially abuts the catalyst coated membrane 13, and the upper surface of the cathode support ring 17, which is distal to the cathode diffusion layer 15, abuts the cathode plate 18. Furthermore, the upper surface of the cathode support ring 17, which is distal to the cathode diffusion layer 15, is substantially flush with the upper surface of the cathode support plate 16, which is distal to the cathode diffusion layer 15, and both abut against the cathode plate 18. The cathode plate 18 is disposed on the side of the cathode support plate 16 and cathode support ring 17, which is distal to the cathode diffusion layer 15. The cathode plate 18 can be made of a corrosion-resistant material such as stainless steel, or can be made of carbon fiber or plastic.

[0040] The anode assembly is arranged on the anode side (lower side in FIG2 ) of the catalyst coated membrane 13 and includes components such as an anode diffusion layer 19, an anode support plate 20, and an anode plate 21, which are arranged in sequence in a direction away from the catalyst coated membrane 13. The anode diffusion layer 19 is arranged close to the anode catalyst layer. The anode diffusion layer 19 is formed of a porous medium material (e.g., titanium) so that water is introduced into the proton exchange membrane of the catalyst coated membrane 13 during water electrolysis to perform a water electrolysis reaction, and to discharge oxygen generated by the catalyst coated membrane 13 at the anode and water after the water electrolysis reaction, and to introduce oxygen and hydrogen into the proton exchange membrane of the catalyst coated membrane 13 during the hydration reaction. The anode support plate 20 is sandwiched between the anode diffusion layer 19 and the anode plate 21 along the stacking direction Y. In addition, the anode support plate 20 may also include a plurality of micropores to further transport water and oxygen. The anode support plate 20 can be processed using titanium. Anode diffusion layer 19 and anode support plate 20 are housed within the space enclosed by support portion 14A of mounting frame 14. Specifically, support portion 14A of mounting frame 14 surrounds the outer periphery of anode diffusion layer 19 and anode support plate 20. Anode plate 21 is disposed on a side of anode support plate 20 away from catalyst coating membrane 13. Anode plate 21 can be made of corrosion-resistant materials such as stainless steel, or can be made of carbon fiber or plastic.

[0041] Continuing with FIG2 , the cathode plate 18 covers the entire upper surface of the mounting frame 14, the cathode support plate 16, and the cathode support ring 17, while the anode plate 21 covers the entire lower surface of the mounting frame 14 and the anode support plate 20. Thus, the cathode support ring 17, the cathode support plate 16, the cathode diffusion layer 15, the catalyst coated membrane 13, the mounting frame 14, the anode diffusion layer 19, and the anode support plate 20 are sandwiched between the cathode plate 18 and the anode plate 21. In one example, the anode plate 21, the mounting frame 14, and the cathode plate 18 are each provided with positioning holes. The multiple fasteners (e.g., multiple positioning pins or multiple bolts) that pass through the two end plates 11 and 12 can also be simultaneously passed through these positioning holes to secure the catalyst coated membrane 13, the cathode assembly, and the anode assembly to each other.

[0042] Each stack unit 10 is divided into a reaction zone Z1 and a non-reaction zone Z2. When the stack unit 10 is used in a water electrolysis stack, water can decompose into hydrogen and oxygen in the reaction zone Z1. The oxygen is directly discharged through the anode diffusion layer 19 and even the anode support plate 20, while the hydrogen is discharged in sequence through the cathode diffusion layer 15 of the cathode assembly and even the cathode support plate 16. When the stack unit 10 is used in a fuel cell, the oxygen delivered through the anode assembly and the hydrogen delivered through the cathode assembly can combine to form water in the reaction zone Z1, thereby converting the chemical energy generated by the reaction between hydrogen and oxygen into electrical energy. Whether in a water electrolysis stack or a fuel cell, the non-reaction zone Z2, other than the reaction zone Z1, must be protected from mixing and explosion. Therefore, a seal 30 or 30' is provided between the anode assembly and the cathode assembly to seal the reaction zone Z1 of the stack unit 10 and prevent leakage of oxygen or hydrogen from the reaction zone Z1.

[0043] 2 and 6 , the seal 30 is annular and at least partially surrounds the periphery of the reaction zone Z1. Specifically, the seal 30 is disposed between the peripheral portion 14B of the mounting frame 14 and the anode diffusion layer 19. This means that the seal 30 surrounds the periphery of the anode diffusion layer 19 and is surrounded by the peripheral portion 14B of the mounting frame 14. The seal 30 is disposed between the catalyst coated membrane 13 and the support portion 14B of the mounting frame 14 along the stacking direction Y. This means that the seal 30 is sandwiched between the catalyst coated membrane 13 and the support portion 14B of the mounting frame 14 along the stacking direction Y. The specific structure of the seal according to the present invention will be described in detail below with reference to FIG3 to FIG8 , wherein FIG3 to FIG5 illustrate a first embodiment according to the present invention, and FIG6 to FIG8 illustrate a second embodiment according to the present invention.

[0044] As shown in Figure 4, the sealing member 30 according to the first embodiment of the present invention includes a substrate 31 and a covering layer 32. The substrate 31 constitutes the main structure of the sealing member 30, and the substrate 31 includes a first material with high hardness and high rigidity, and is preferably made of the first material. The first material can be, for example, a metal. The covering layer 32 includes a second material with a lower hardness than the first material, and is preferably made of the second material. The second material can be an elastically compressible material, such as a rubber material, and these rubber materials include but are not limited to: nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), fluororubber (FKM), acrylic rubber (ACM), ethylene propylene diene monomer (EPDM), butyl rubber (isobutylene-isoprene rubber, IIR), silicone rubber, silicone fluororubber, etc.

[0045] The substrate 31 includes a first surface 311 and a second surface 312 that are disposed opposite each other along its thickness direction. The thickness direction of the substrate 31 corresponds to the stacking direction Y of the catalyst coated membrane 13, cathode assembly, and anode assembly in FIG2 . Therefore, the first surface 311 and the second surface 312 respectively abut against the catalyst coated membrane 13 and the support portion 14B of the mounting frame 14. Furthermore, the substrate 31 includes a first side surface 313 and a second side surface 314 that are disposed opposite each other along a first direction. The first direction is orthogonal to the thickness direction and is shown as a left-right direction in FIG4 . However, it should be understood that the first direction is not limited to the left-right direction in FIG4 . Since the seal 30 is annular, the first direction actually corresponds to the radial direction of the seal 30 in FIG3 . The first side surface 313 is connected to the first surface 311 and the second surface 312, respectively, and the second side surface 314 is connected to the first surface 311 and the second surface 312, respectively.

[0046] The covering layer 32 at least partially covers the first surface 311 and the second surface 312 of the base 31. Preferably, in addition to covering the first surface 311 and the second surface 312 of the base 31, the covering layer 32 also covers the first side surface 313 and the second side surface 314 of the base 31. In other words, the covering layer 32 completely covers the base 31, thereby achieving better sealing performance.

[0047] The cover layer 32 and the base body 31 are inseparable from each other, for example, they can be fixedly connected by form-locking and / or material connection. In this embodiment, the cover layer 32 can be directly and closely attached to the base body 31 by sintering, hot melting, rolling, rolling, molding, etc.

[0048] As shown in Figure 4 , the cover layer 32 is provided with a plurality of raised portions 321 spaced apart along a first direction, resulting in a wavy appearance on both the upper and lower surfaces of the cover layer 32. Furthermore, in the first direction, at least a portion of the raised portions 321 on the first surface 311 are offset from at least a portion of the raised portions 322 on the second surface 312. In other words, in the first direction, the maximum thickness of at least a portion of the raised portions 321 on the first surface 311 and the maximum thickness of at least a portion of the raised portions 322 on the second surface 312 are not aligned.

[0049] Since a plurality of spaced-apart raised portions 321 are respectively provided on the first surface 311 and the second surface 312 of the base 31, and at least a portion of the raised portions 321 provided on the first surface 311 are offset from at least a portion of the raised portions 321 provided on the second surface 312, when the seal 30 is subjected to an external force perpendicular to its thickness direction (e.g., F1 and F2 in FIG4 ), the raised portions 321 on the first surface 311 and the raised portions 321 on the second surface 312 are squeezed, causing the base 31 to deform into a wavy shape. As a result, the deformed base 31 provides support to the cover layer 32 like a spring, thereby making the entire seal 30 have a higher sealing performance. Since the deformed base 31 can store energy like a spring, it can provide a smaller support force when the fit tolerance gap of the battery stack unit 10 is small, and a larger support force when the fit tolerance gap of the battery stack unit 10 is large. Therefore, the seal 30 according to the embodiment of the present invention has good adaptability and can provide good sealing performance.

[0050] In addition, according to the present invention, since multiple protrusions 321 are respectively provided on the first surface 311 and the second surface 312 of the base 31, when the seal 30 is subjected to an external force perpendicular to its thickness direction (such as F1 and F2 in Figure 4), multiple stress-bearing areas will be formed accordingly, thereby further improving the sealing performance of the seal 30.

[0051] As shown in Figures 3 and 4, each of the plurality of raised portions 311 spaced apart in the first direction extends in a second direction, the second direction being orthogonal to both the first direction and the thickness direction Y. The second direction is shown in Figure 4 as a direction perpendicular to the paper, but it should be understood that since the seal 30 is annular, the second direction actually corresponds to the circumferential direction of the seal 30 in Figure 3. In conjunction with Figure 2, each raised portion 321 extends in a manner that at least partially, preferably completely, surrounds the periphery of the reaction zone Z1. Arranging the raised portions 321 in this manner can further prevent oxygen and hydrogen from leaking from the reaction zone Z1 and causing an explosion, thereby further improving the sealing performance of the seal 30.

[0052] Preferably, the protrusions 321 provided on the first surface 311 and the protrusions 321 provided on the second surface 312 extend in the same direction, that is, both extend along the circumferential direction of the sealing member 30 .

[0053] Each protrusion 321 has a uniform cross-section along its extension direction. Preferably, each protrusion 321 is peak-shaped, with the thickness gradually increasing from opposite sides toward the center. This gradual thickness variation allows the seal 30 to gradually deform when subjected to force, resulting in a good sealing effect.

[0054] Continuing with reference to FIG. 4 , the covering layer 32 of the sealing member 30 further includes a plurality of recessed portions 322 formed between adjacent protrusions 321. The plurality of protrusions 321 and the plurality of recessed portions 322 are staggered along a first direction on the same surface. That is, a recessed portion 322 is provided between two adjacent protrusions 321, and a protrusion 321 is provided between two adjacent recessed portions 322. Furthermore, in the first direction, at least a portion of the recessed portions 322 provided on the first surface 311 is offset from at least a portion of the recessed portions 322 provided on the second surface 312. This offset arrangement enables the base 31 to undergo a greater deformation when the sealing member 30 is subjected to an external force perpendicular to its thickness direction, thereby providing the entire sealing member 30 with enhanced sealing performance and good adaptability.

[0055] Each recessed portion 322 has a uniform cross-section along its extension direction. Preferably, each recessed portion 322 is valley-shaped, with the thickness gradually decreasing from opposite sides toward the center. This gradual thickness change allows the seal 30 to gradually deform when subjected to force, resulting in a good sealing effect.

[0056] Preferably, the plurality of raised portions 321 and the plurality of recessed portions 322 are continuously connected, thereby forming the cover layer 32 with a continuous wavy surface. Furthermore, the connection between the raised portions 321 and the recessed portions 322 forms a smooth transition. This reduces stress concentration at the connection points, increases connection strength, and thus improves the service life of the seal 30.

[0057] Preferably, along the thickness direction of the base 31, the maximum thickness position of at least a portion of the raised portions 321 disposed on the first surface 311 corresponds to the minimum thickness position of at least a portion of the recessed portions 322 disposed on the second surface 312, while the minimum thickness position of at least a portion of the recessed portions 322 disposed on the first surface 311 corresponds to the maximum thickness position of at least a portion of the raised portions 321 disposed on the second surface 312. As shown in FIG4 , the maximum thickness position of all the raised portions 321 disposed on the first surface 311 corresponds to the minimum thickness position of all the recessed portions 322 disposed on the second surface 312, while the minimum thickness position of all the recessed portions 322 disposed on the first surface 311 corresponds to the maximum thickness position of all the raised portions 321 disposed on the second surface 312. Figure 4 illustrates a configuration in which the highest valley peaks of all raised portions 321 on the first surface 311 correspond to the lowest valley bottoms of all recessed portions 322 on the second surface 312, and vice versa. Because the maximum thickness of the raised portions 321 on one surface is aligned with the minimum thickness of the recessed portions 322 on the other surface, when the seal 30 is subjected to an external force perpendicular to its thickness, the base 31 can undergo a greater deformation in the thickness direction. This allows the seal 30 to accommodate larger tolerance gaps in the stack unit 10, resulting in improved sealing performance and adaptability.

[0058] As shown in FIG3 , the seal 30 is annular and generally has a quadrilateral shape to match the shapes of the anode and cathode assemblies, thereby enhancing the fit and ensuring good sealing performance of the seal. However, the present invention is not limited to this. In other examples, the seal may also have an O-shape or other polygonal structure. Preferably, the four corners of the seal 30 are all rounded transitions, thereby further matching the structure of the mounting frame 40.

[0059] 3 and 4 , the flat, annular seal 30 includes an outer annular surface 315 and an inner annular surface 316 disposed opposite each other along a first direction, where the first direction corresponds to the radial direction of the seal 30. The outer annular surface 315 is located adjacent to the first side surface 313 of the substrate 31, while the inner annular surface 316 is located adjacent to the second side surface 314 of the substrate 31. Thus, in the radial direction of the substrate 31, i.e., from the inner annular surface 316 to the outer annular surface 315 of the seal 30, a plurality of protrusions 321 and a plurality of recesses 322 are alternately arranged, forming a wavy cover layer 32. This allows the seal 30 to prevent oxygen and hydrogen from leaking from the reaction zone Z1 and causing an explosion.

[0060] As shown in Figure 3, each raised portion 321 and / or each recessed portion 322 extends at least partially around the circumference of the annular base 31. Preferably, each raised portion 321 and / or each recessed portion 322 extends around the entire circumference of the annular base 31. That is, each raised portion 321 extends in an annular shape, and each recessed portion 322 also extends in an annular shape. As a result, the seal 30 can effectively prevent the leakage of oxygen and hydrogen in the reaction zone Z1 of the stack unit 10 and the resulting explosion along the entire circumference.

[0061] Figures 6 to 8 show a second embodiment of a seal according to the present invention. The seal 30' in the second embodiment has substantially the same base as the seal 30 in the first embodiment, and the only difference lies in the arrangement of the raised portion and the recessed portion. The similarities are not repeated here, and only the differences are described in detail below.

[0062] As shown in FIG6 , a seal 30' according to a second embodiment of the present invention is flat and annular, and includes an outer annular surface 315' and an inner annular surface 316' disposed opposite each other along a first direction, wherein the first direction corresponds to the radial direction of the seal 30'. As shown in FIG7 , in the thickness direction of the base 31', the raised portion 321' disposed on the first surface 311' near the outer annular surface 315' at least partially overlaps with the raised portion 321' disposed on the second surface 312' near the outer annular surface 315'. Preferably, in the thickness direction of the base 31', the maximum thickness position of the raised portion 321' disposed on the first surface 311' near the outer annular surface 315' is substantially aligned with the maximum thickness position of the raised portion 321' disposed on the second surface 312' near the outer annular surface 315'. That is, the maximum thickness positions of the upper and lower raised portions 321' near the outer annular surface 315' are aligned with each other.

[0063] Furthermore, in the thickness direction of the base body 31', the raised portion 321' disposed on the first surface 311' near the inner annular surface 316' and the raised portion 321' disposed on the second surface 312' near the inner annular surface 316' are at least partially overlapped. Preferably, in the thickness direction of the base body 31', the maximum thickness position of the raised portion 321' disposed on the first surface 311' near the inner annular surface 316' and the maximum thickness position of the raised portion 321' disposed on the second surface 312' near the inner annular surface 316' are substantially aligned. In other words, the maximum thickness positions of the upper and lower raised portions 321' near the inner annular surface 316' are aligned with each other.

[0064] Therefore, when the seal 30' is subjected to an external force perpendicular to its thickness direction, the upper and lower protrusions 321' close to the outer annular surface 315' (i.e., the first side surface 313' close to the base 311') can form a stress-bearing area, and at the same time, the upper and lower protrusions 321' close to the inner annular surface 316' (i.e., the second side surface 314' close to the base 311') can also form a stress-bearing area, thereby further improving the sealing performance of the seal 30.

[0065] In the first direction (i.e., the radial direction from the inner annular surface 316' to the outer annular surface 315'), in addition to the upper and lower protrusions 321' near the outer annular surface 315' (corresponding to the first side surface 313') being aligned and the upper and lower protrusions 321' near the inner annular surface 316' (corresponding to the second side surface 314') being aligned, the other protrusions 321' disposed on the first surface 311' and the other protrusions 321' disposed on the second surface 312' are all staggered. Therefore, when the seal 30' is subjected to an external force perpendicular to its thickness direction, the staggered protrusions 321' on the first surface 311' and the second surface 312' are squeezed, causing the base 31' to deform into a wavy shape. The deformed base 31' then provides support to the cover layer 32' like a spring, thereby improving the sealing performance of the entire seal 30'.

[0066] In addition, when the catalyst coating membrane 13, cathode assembly, anode assembly, and mounting frame 14 of each stack unit 10 are assembled together, assembly gaps may appear, and these assembly gaps can cause hydrogen and oxygen to leak during transportation, and may even cause oxygen on the anode side to escape into the hydrogen on the cathode side. Therefore, in order to further enhance the sealing performance of hydrogen and oxygen, for example, as shown in Figure 2, a cathode seal 40 is sandwiched between the cathode plate 18 of the cathode assembly and the outer peripheral portion 14B of the mounting frame 14 to reduce hydrogen leakage to the external environment. Similarly, an anode seal 50 is also provided between the anode plate 21 of the anode assembly and the outer peripheral portion 14B of the mounting frame 14 to reduce oxygen leakage to the external environment. In an exemplary embodiment, the cathode seal 40 and the anode seal 50 can have the same structural design as the seals 30, 30' according to the present invention. Of course, the present invention is not limited to this, and the cathode seal and the anode seal can have different structural designs from the seals 30, 30' according to the present invention, as long as they can enhance the sealing performance of hydrogen and oxygen.

[0067] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.

Claims

1. A seal (30, 30') for a water electrolysis stack or a fuel cell, comprising: A substrate (31, 31'), which is sheet-shaped and includes a first surface (311, 311') and a second surface (312, 312') that are oppositely arranged along its thickness direction (Y); And A covering layer (32, 32'), which has a wavy surface and at least partially covers the first surface (311, 311') and the second surface (312, 312') of the substrate (31, 31'). The covering layer (32, 32') includes an elastically compressible material and is provided with a plurality of protruding portions (321, 321') spaced along a first direction. The first direction is orthogonal to the thickness direction, wherein In the first direction, at least a part of the protruding portions (321, 321') provided on the first surface (311, 311') are arranged offset from at least a part of the protruding portions (321, 321') provided on the second surface (312, 312').

2. The seal (30, 30') according to claim 1, wherein, Each of the plurality of protruding portions (321, 321') spaced in the first direction extends in a second direction. The second direction is orthogonal to both the first direction and the thickness direction.

3. The seal (30, 30') according to claim 2, wherein, The protruding portions (321, 321') provided on the first surface (311, 311') and the protruding portions (321, 321') provided on the second surface (312, 312') have the same extending direction.

4. The seal (30, 30') according to claim 2, wherein, The cross-section of the same protruding portion (321, 321') is the same in its extending direction.

5. The seal (30, 30') according to claim 1, wherein The covering layer (32, 32') completely covers the substrate (31, 31').

6. The seal (30, 30') according to claim 1, wherein The seal (30, 30') is formed into a flat ring shape and includes an outer ring surface (315, 315') and an inner ring surface (316, 316') that are oppositely arranged.

7. The seal (30, 30') according to claim 6, wherein In the thickness direction (Y), the protruding portion (321') provided on the first surface (311') and close to the outer ring surface (315') and the Protruding portion (321') provided on the second surface (312') and close to the outer ring surface (315') at least partially overlap; And / or In the thickness direction (Y), the protruding portion (321') provided on the first surface (311') and close to the inner ring surface (316') and the protruding portion (321') provided on the second surface (312') and close to the inner ring surface (316') at least partially overlap.

8. The seal (30, 30') according to claim 6, wherein In the thickness direction (Y), the maximum thickness positions of the protrusions (321') provided on the first surface (311') near the outer ring surface (315') are substantially aligned with the maximum thickness positions of the protrusions (321') provided on the second surface (312') near the outer ring surface (315). and / or In the thickness direction (Y), the maximum thickness positions of the protrusions (321') provided on the first surface (311') near the inner ring surface (316) are substantially aligned with the maximum thickness positions of the protrusions (321') provided on the second surface (312') near the inner ring surface (316).

9. The seal (30, 30') according to claim 6, wherein Each protrusion (321, 321') at least partially surrounds and extends circumferentially around the circumferentially shaped base body (31, 31').

10. The seal (30, 30') according to any one of claims 1 to 9, wherein The base body (31, 31') comprises a material having a higher hardness than the elastically compressible material of the covering layer (32, 32').

11. The seal (30, 30') according to any one of claims 1 to 9, wherein The covering layer (32, 32') is directly attached to the base body (31, 31') and is fixedly connected to the base body (31, 31').

12. A water electrolysis stack or a fuel cell, comprising a cathode assembly, a catalyst coated membrane, and an anode assembly stacked one above the other in sequence, wherein The water electrolysis stack or the fuel cell further comprises: The seal (30, 30') according to any one of claims 1 to 11 for sealing the reaction zone of the water electrolysis stack or the fuel cell, the seal (30, 30') is clamped between the cathode assembly and the catalyst coating, and the thickness direction of the seal (30, 30') corresponds to the stacking direction of the cathode assembly, the catalyst coated membrane, and the anode assembly; The protrusions (321, 321') of the seal (30, 30') are arranged in a manner that at least partially surrounds the outer periphery of the reaction zone.

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