Electrolytic unit, electrolytic apparatus, and method for producing electrolytic unit

Abstract

The present application provides an electrolytic unit comprising: a first plate and a second plate; a stack formed by an anodic porous transmission layer, an anodic electrode layer, a membrane, a cathodic electrode layer, and a cathodic porous transmission layer stacked in sequence along a stacking direction, the stack being disposed between the first and second plates in the stacking direction; and a first and a second sealing members respectively disposed between the first and second plates in the stacking direction. The first sealing member surrounds the stack in a direction perpendicular to the stacking direction. The second sealing member is disposed outside the first sealing member and surrounding the first sealing member in a direction perpendicular to the stacking direction. The second sealing member is vulcanized to be fixedly attached to the first and second plates and retain the first and second plates as an integral structure, thereby maintaining the first sealing member and the stack therebetween. The present application also provides a method of producing the electrolytic unit and an electrolytic apparatus comprising the electrolytic unit. The electrolytic unit and the electrolytic apparatus according to the present application are easy to manufacture, assemble, and maintain.

Description

[0001] Electrolytic Unit, Electrolytic Apparatus, and Method for Producing Electrolytic Unit Technical Field

[0002] The present application generally relates to the field of electrolytic technology, in particular to an electrolytic unit for an electrolytic apparatus and a method of producing the same, and to an electrolytic apparatus comprising such an electrolytic unit.

[0003] Background

[0004] Hydrogen is used for a wide range of purposes, covering chemical industry, energy, transportation, electronics and many other fields. There are a variety of hydrogen production methods at present, of which the electrolytic hydrogen production technology is a hot research topic in the field of hydrogen production. Taking an alkaline solution electrolytic system as an example, the electrolyte is conveyed via a supply line to an electrolytic apparatus and water in the electrolyte is electrolyzed in the electrolytic apparatus. The reaction products (hydrogen and oxygen) and unconsumed electrolytes from the electrolytic apparatus are conveyed through a discharge line and separated from one another. The reaction products are then purified and stored, while the unconsumed electrolytes are re-conveyed to the electrolytic apparatus via the supply line.

[0005] The electrolytic apparatus typically includes a plurality of electrolytic units stacked together and end plates for holding these electrolytic units together. Each electrolytic cell typically includes an anodic plate, an anodic porous transmission layer, an anodic electrode layer, a membrane (a separator in an alkaline solution electrolytic system), a cathodic electrode layer, a cathodic porous transmission layer, and a cathodic plate (the anodic and cathodic plates may be formed as bipolar or monopole plates) stacked in sequence. These components are held together by pressure. Stacking these components of the electrolytic unit one by one during the manufacture of the electrolytic apparatus is time-consuming and prone to assembly errors, such as misalignment, deformation, and excessive stress, resulting in inefficient assembly and a high risk of quality issues.

[0006] Moreover, some components (e.g., membranes) of the electrolytic unit may be damaged or fail during the service life of the electrolytic unit (e.g., as high as 120,000 hours) and thus require the maintenance of the electrolytic apparatus. However, the electrolytic unit and the electrolytic apparatus produced through the above-described producing process are difficult to disassemble and reassemble, and other electrolytic units or other components may also bedamaged during the maintenance process.

[0007] Therefore, there is an urgent need for improvements to existing electrolytic apparatus and the electrolytic units thereof.

[0008] Summary of the Invention

[0009] An object of the present application is to provide an improved electrolytic unit and a method for producing the same, as well as an electrolytic apparatus comprising the electrolytic unit, to overcome at least one of the above-described defects in the prior art.

[0010] In one aspect, the present application provides an electrolytic unit for an electrolytic apparatus, comprising: a first plate and a second plate; a stack formed by an anodic porous transmission layer, an anodic electrode layer, a membrane, a cathodic electrode layer, and a cathodic porous transmission layer stacked in sequence along a stacking direction, the stack being disposed between the first plate and the second plate in the stacking direction; and a first sealing member and a second sealing member respectively disposed between the first plate and the second plate in the stacking direction. The first sealing member surrounds the stack in a direction perpendicular to the stacking direction, and the second sealing member is disposed on a side of the first sealing member away from the stack in the direction perpendicular to the stacking direction. The second sealing member is vulcanized to be fixedly attached to the first plate and the second plate and retain the first plate and the second plate as an integral structure, such that the first sealing member and the stack are maintained between the first plate and the second plate.

[0011] In another aspect, the present application provides an electrolytic apparatus, comprising: a plurality of electrolytic units, each of the plurality of electrolytic units being the electrolytic unit mentioned above, and the plurality of electrolytic units stacked in the stacking direction; and a first end plate and a second end plate clamping the plurality of electrolytic units therebetween in the stacking direction to hold the plurality of electrolytic units together.

[0012] In yet another aspect, the present application provides a method for producing an electrolytic unit, comprising: (i) disposing a stack formed by stacking an anodic porous transmission layer, an anodic electrode layer, a membrane, a cathodic electrical layer, and a cathodic porous transmission layer in sequence along a stacking direction and a first sealing member between a first plate and a second plate in the stacking direction, wherein the first sealing member surrounding the stack in a direction perpendicular to the stacking direction; (ii)disposing a vulcanizable sealing material between the first plate and the second plate in the stacking direction such that the sealing material is on a side of the first sealing member awayfrom the stack in the direction perpendicular to the stacking direction; and (iii)vulcanizing the sealing material to form a second sealing member, wherein the second sealing member surrounds the first sealing member in the direction perpendicular to the stacking direction and is fixedly attached to the first plate and the second plate and retain the first plate and the second plate as an integral structure, such that the first sealing member and the stack are maintained between the first plate and the second plate.

[0013] The electrolytic unit and the electrolytic apparatus comprising such an electrolytic unit in accordance with the present application are easy to produce, assemble, and maintain, have high reliability and flexibility, and are significantly cost-effective. Moreover, the method for producing the electrolytic unit according to the present application can improve the integration, reliability, and manufacturing efficiency of the electrolytic unit.

[0014] These techniques may be used alone or in any suitable combination. The foregoing summary is provided by way of illustration and is not meant to be limiting.

[0015] Brief Description of the Drawings

[0016] The above and other aspects of the present disclosure will be understood and appreciated more thoroughly below in connection with the appended drawings. It should be noted that the drawings are merely illustrative and not drawn to scale. The same components are indicated by the same reference numerals in different drawings. In addition, for the sake of brevity, not all components or portions of the electrolytic apparatus and the electrolytic units thereof according to the present disclosure are shown or labeled in the drawings. It should be understood that the dimensions, proportional relationships, and number of components in the drawings are not intended to limit the present application. In the accompanying drawings:

[0017] FIG. l is a schematic partial cross-sectional view of an electrolytic apparatus according to some embodiments of the present application;

[0018] FIG. 2 is a schematic cross-sectional view of an electrolytic unit included in the electrolytic apparatus of FIG. 1;

[0019] FIG. 3 is a schematic cross-sectional view of the electrolytic unit of FIG. 2 along line A-A in FIG. 2;

[0020] FIG. 4 is a schematic front view of a plate of the electrolytic unit of FIG. 2;

[0021] FIG. 5 is a schematic cross-sectional view of the plate of FIG. 4 along line B-B in FIG.

[0022] 4;

[0023] FIG. 6A is a schematic cross-sectional view of an optional type of electrolytic unit that may be used in the electrolytic apparatus of FIG. 1;FIG. 6B is an enlarged view of an area 6B in FIG. 6A;

[0024] FIG. 7A is a schematic cross-sectional view of another selectable type of electrolytic unit that may be used in the electrolytic apparatus of FIG. 1;

[0025] FIG. 7B is an enlarged view of an area 7B in FIG. 7A;

[0026] FIGS. 8 A and 8B are schematic cross-sectional views similar to FIG. 2, illustrating one exemplary method of arranging a vulcanizable sealing material into the electrolytic unit to form a sealing member; and

[0027] FIGS. 9A to 9C are schematic cross-sectional views similar to FIG. 2, illustrating another exemplary method of arranging the vulcanizable sealing material into the electrolytic unit to form a sealing member.

[0028] Detailed Description of the Embodiments

[0029] Some examples of the present application are described in detail below in conjunction with the drawings. In the following embodiments, an alkaline solution electrolytic apparatus and an electrolytic unit thereof are taken as an example for ease of description of the electrolytic apparatus and the electrolytic unit thereof, as well as corresponding production method and assembly method according to the present application. It is to be understood that this example does not imply any limitation to the present application, and the electrolytic apparatus and the electrolytic unit thereof or variations thereof according to the present application can be used in other types of electrolytic systems, such as a protic exchange membrane (PEM) electrolytic system, and an anion exchange membrane (AEM) electrolytic system. Furthermore, features in the examples of the present application may be combined with each other, provided there is no conflict.

[0030] FIG. 1 schematically illustrates an electrolytic apparatus 10 for an electrolytic system (not shown) in accordance with some embodiments of the present application. The electrolytic system may be an alkaline solution electrolytic system, which uses an alkaline solution (e.g., potassium hydroxide solution, sodium hydroxide solution, etc.) as an electrolyte. The electrolytic apparatus 10 is configured to electrolyze water in an alkaline electrolyte to generate hydrogen and oxygen. The electrolytic apparatus 10 may also be referred to as an "electrolytic cell" or an "electrolyzer." The electrolytic apparatus 10 may include a housing (not shown) and a plurality of electrolytic units 20 housed within the housing.

[0031] The plurality of electrolytic units 20 may have the same or substantially the same configuration as each other. FIGS. 2 and 3 show one electrolytic unit 20 of the plurality of electrolytic units 20. The electrolytic unit 20 may also be referred to as a "single electrolyticcell." As shown in FIG. 2, the electrolytic unit 20 includes a first plate (an anodic plate) 21, a second plate (a cathodic plate) 22, and a stack formed by an anodic porous transmission layer 23, an anodic electrode layer 24, a membrane (here, a diaphragm) 25, a cathodic electrode layer 26, and a cathodic porous transmission layer 27 stacked in sequence along a stacking direction 28. That is, the membrane 25 is located between the anodic electrode layer 24 and the cathodic electrode layer 26, the anodic porous transmission layer 23 is located on a side of the anodic electrode layer 24 away from the membrane 25, and the cathodic porous transmission layer 27 is located on a side of the cathodic electrode layer 26 away from the membrane 25. The layers may be in contact with each other. The first plate 2 land the second plate 22 are spaced apart from each other in the stacking direction 28, and the stack is disposed between the first plate 21 and the second plate 22 in the stacking direction 28. The first plate 21 is located on a side of the anodic porous transmission layer 23 away from the anodic electrode layer 24, and the second plate 22 is located on a side of the cathodic porous transmission layer 27 away from the cathodic electrode layer 26. The first plate 21 and the second plate 22 may be electrically connected to an external DC power source (not shown) and may be submerged in an electrolyte with the stack. The membrane 25 allows ions to pass through but prohibits gas molecules from passing through.

[0032] Taking one electrolytic unit 20 as an example, during operation, the electrolyte will circulate through the electrolytic unit 20 and the external DC power source will supply direct current to the first plate 21 and the second plate 22 of the electrolytic unit 20. At the cathodic electrode layer 26, water molecules gains electrons to generate hydrogen molecules and hydroxide ions (i.e., a reduction reaction occurs: 4H2() 4e —f2H24()H ). Here, the hydrogen molecules, unable to pass through the membrane 25, are discharged with the electrolyte, while the hydroxide ions, driven by voltage, pass through the membrane 25 from the cathodic electrode layer 26 to the anodic electrode layer 24. At the anodic electrode layer 24, the hydroxide ions lose electrons to generate oxygen molecules and water molecules (i.e., an oxidation reaction occurs: 4()H~^2H2()+()2+4e~). Here, the oxygen molecules, unable to pass through the membrane 25, are discharged with the electrolyte.

[0033] In accordance with the same principles, each electrolytic unit 20 may receive electrolyte and, after the above described electrochemical reaction, discharge hydrogen-containing electrolyte on the cathodic side (i.e., discharge the cathodic side reaction products and unconsumed electrolyte) while discharging oxygen-containing electrolyte on the anodic side (i.e., discharge the anodic side reaction product and unconsumed electrolyte). Accordingly, the electrolytic apparatus 10 is provided with a hydrogen side (may also be referred to as a cathodicside) outlet 10a for discharging hydrogen-containing electrolyte, an oxygen side (may also be referred to as an anodic side) outlet 10b for discharging oxygen-containing electrolyte, and an inlet 10c for receiving electrolyte.

[0034] As shown in FIGS. 2 and 3, each electrolytic unit 20 includes an anodic side outlet header channel 20a, a cathodic side outlet header channel 20b, and an electrolyte inlet header channel 20c. When the plurality of electrolytic units 20 are stacked along the stacking direction 28 as shown in FIG. 1 and held together, the anodic side outlet header channel 20a, the cathodic side outlet header channel 20b, and the electrolyte inlet header channel 20c of the plurality of electrolytic units 20 are aligned in the stacking direction 28, respectively, to form an anodic side outlet header, a cathodic side outlet manifold, and an electrolyte inlet header. The electrolyte inlet header dispenses the electrolyte received through the inlet 10c into each electrolytic unit 20. The cathodic side outlet header collects the hydrogen-containing electrolyte discharged from each electrolytic unit 20 to the hydrogen side outlet 10a, and the anodic side outlet header collects the oxygen-containing electrolyte discharged from each electrolytic unit 20 to the oxygen side outlet 10b.

[0035] With continued reference to FIGS. 2 and 3, each electrolytic unit 20 further includes a first sealing member 30 and a second sealing member 40, which are respectively disposed between the first plate 21 and the second plate 22 in the stacking direction 28, to provide a seal separating the interior space of the electrolytic unit 20 for electrolyte flow from the exterior of the electrolytic unit 20.

[0036] In particular, the first sealing member 30 surrounds the stack formed by the anodic porous transmission layer 23, the anodic electrode layer 24, the membrane 25, the cathodic electrode layer 26, and the cathodic porous transmission layer 27 in a direction perpendicular to the stacking direction 28. In other words, the first sealing member 30 is capable of surrounding the interior space of the electrolytic unit 20 for electrolyte flow to provide a seal, thereby isolating it from the exterior of the electrolytic unit 20. The second sealing member 40 is disposed on a side of the first sealing member 30 away from the stack (hereinafter referred to as the “outer side”) in a direction perpendicular to the stacking direction 28 and surrounds the first sealing member 30. As such, the second sealing member 40 is capable of providing a second seal that surrounds the interior space of the electrolytic unit 20 to separate it from the exterior of the electrolytic unit 20, thereby further enhancing the sealing effect. The second sealing member 40 is also fixedly attached to the first plate 21 and the second plate 22 to retain the first plate 21 and the second plate 22 as an integral structure. As used herein, an integral structure refers to components being held together as a single unit, such that they can be moved(e.g., moved to a designated location or position), installed (e.g., installed in the electrolytic apparatus 10) and removed (e.g., detached from the electrolytic apparatus 10). As the first sealing member 30 and the stack are disposed between the first plate 21 and the second plate 22, by holding the first plate 21 and the second plate 22 together as an integral structure by the second sealing member 40, the first plate 21 and the second plate 22 hold the first sealing member 30 and the stack therebetween.

[0037] In this way, the entire electrolytic unit 20 (i.e., the stack, the first plate 21, the second plate 22, the first sealing member 30, and the second sealing member 40) can be formed as an integral unit, i.e., a single piece integral structure. During the manufacture of the electrolytic apparatus 10, the electrolytic apparatus 10 may be formed by first forming each electrolytic unit 20 as an integral component and then stacking each electrolytic unit 20 together. The integrated electrolytic unit 20 is easier to operate when manufacturing the electrolytic apparatus 10, thereby improving the manufacturing efficiency of the electrolytic apparatus 10. In addition, the integrated electrolytic unit 20 can significantly reduce assembly errors (such as misalignment, deformation, and excessive stress) during the manufacture of the electrolytic apparatus 10, thereby improving the quality of the electrolytic apparatus 10. When some of the components of the electrolytic unit 20 are damaged or fail and need to be replaced, the integrated electrolytic unit 20 is easier to disassemble, replace, and reassemble, thereby improving the maintenance efficiency of the electrolytic apparatus 10 and reducing its maintenance costs. Compared to an electrolytic unit 20 in the prior art in which components are held together by pressure, the integrated electrolytic unit 20 has a higher degree of integration and reliability. Further, the integrated electrolytic unit 20 provides the flexibility to increase or decrease the number of electrolytic units 20 in the electrolytic apparatus 10 as needed, thereby increasing the flexibility of the electrolytic apparatus 10. Therefore, the electrolytic unit 20 and the electrolytic apparatus 10 comprising such an electrolytic unit 20 in accordance with the present application are prone to manufacture, assembly, and maintenance, have high reliability and flexibility, and are significantly cost-effective.

[0038] The first sealing member 30 isolates the second sealing member 40 from the aforementioned stack. That is, the first sealing member 30 separates the second sealing member 40 from the interior space of the electrolytic unit 20 for electrolyte flow. With this configuration, the first sealing member 30 forms a first seal (or a “primary seal”), and the second sealing member 40 forms a second seal (or a “secondary seal”) on an outer side of the first sealing member 30. Such a dual seal can improve the reliability and service life of the electrolytic unit 20.As shown in FIGS. 2 and 3, in each electrolytic unit 20, each of the anodic side outlet header channel 20a, the cathodic side outlet header channel 20b, and the electrolyte inlet header channel 20c may extend through the first sealing member 30 in the stacking direction 28. In other words, the first sealing member 30 may include a plurality of apertures extending along the stacking direction 28 through the first sealing member 30, and these apertures may form a section of the anodic side outlet header channel 20a, the cathodic side outlet header channel 20b, and the electrolyte inlet header channel 20c, respectively. With this configuration, the first sealing member 30 forms a first seal around each header channel, and the second sealing member 40 forms a second seal outside the first sealing member 30. Providing a dual seal around each header channel may further improve the reliability and service life of the electrolytic unit 20.

[0039] In applications where the electrolytic unit 20 is used to electrolyze water in the alkaline electrolyte, the first sealing member 30 may be made of a sealing material resistant to alkaline electrolyte corrosion. For example, the sealing material may be polytetrafluoroethylene (PTFE). Exemplarily, the first sealing member 30 may be formed in the form of a sealing gasket.

[0040] In some embodiments, the stack formed by the anodic porous transmission layer 23, the anodic electrode layer 24, the membrane 25, the cathodic electrode layer 26, and the cathodic porous transmission layer 27 stacked in sequence along the stacking direction 28 and the first sealing member 30 may be respectively clamped between the first plate 21 and the second plate 22 in the stacking direction 28. That is, the stack and the first sealing member 30 are held together by the clamping force applied by the first plate 21 and the second plate 22, respectively. As will be described specifically below, for the manufactured electrolytic unit 20, the clamping force of the first plate 21 and the second plate 22 is provided by the second sealing member 40 that retains the first plate 21 and the second plate 22 as an integral structure. When a plurality of electrolytic units 20 are assembled in the electrolytic apparatus 10, a grip 50 (FIG. 1) applies a clamping force to the plurality of electrolytic units 20 to hold the plurality of electrolytic units 20 together. In this instance, the clamping force of the first plate 21 and the second plate 22 to the stack is further provided by the grip 50.

[0041] In some embodiments, as best shown in FIG. 2, the first sealing member 30 may at least receive edges of the anodic electrode layer 24, the membrane 25, and the cathodic electrode layer 26 in a direction perpendicular to the stacking direction 28 therein to retain at least the anodic electrode layer 24, the membrane 25, and the cathodic electrode layer 26 as an integral structure.

[0042] For example, the first sealing member 30 may receive edges of the anodic electrode layer24, the membrane 25, and the cathodic electrode layer 26 therein (e.g., molding the first sealing member 30 on the edges) to retain the anodic electrode layer 24, the membrane 25, and the cathodic electrode layer 26 as an integral structure. With this configuration, the first sealing member 30, the anodic electrode layer 24, the membrane 25, and the cathodic electrode layer 26 can be formed as an integral structure, i.e., a single piece integral structure. During the manufacture of the electrolytic unit 20, an integrated electrolytic unit 20 can be formed by first forming the first sealing member 30, the anodic electrode layer 24, the membrane 25, and the cathodic electrode layer 26 into an integral structure, then stacking the first plate 21, the second plate 22, the anodic porous transmission layer 23, and the cathodic porous transmission layer 27 with the integral structure in the aforementioned manner, and then holding the first plate 21 and the second plate 22 as an integral structure by the second sealing member 40. The first sealing member 30, the anodic electrode layer 24, the membrane 25, and the cathodic electrode layer 26 formed as an integral structure are easier to operate when manufacturing the electrolytic unit 20, thereby improving the manufacturing efficiency of the electrolytic unit 20. Moreover, such an integrated structure can significantly reduce assembly errors (such as misalignment, deformation, and excessive stress) during the assembly of the electrolytic unit 20, thereby improving the quality of the electrolytic unit 20. When some of the components of the electrolytic unit 20 are damaged or fail and need to be replaced, the integrated structure is easier to disassemble, replace, and reassemble, thereby improving the maintenance efficiency of the electrolytic unit 20 and reducing its maintenance costs. Compared to an electrolytic unit 20 in the prior art in which components are held together by pressure, such an integrated structure has a higher degree of integration and reliability. Thus, such an integrated structure can further improve the integration, manufacturability, and reliability of the electrolytic unit 20.

[0043] As another example, the first plate 21 may be formed as an integral structure with the anodic porous transmission layer 23 (e.g., by bonding), and the second plate 22 may be formed as an integral structure with the cathodic porous transmission layer 27 (e.g., by bonding). Subsequently, these two integral structures may be stacked with the integral structure formed by the first sealing member 30, the anodic electrode layer 24, the membrane 25, and the cathodic electrode layer 26. Subsequently, the first plate 21 and the second plate 22 can be held together using the second sealing member 40 to retain these structures together, thereby forming the integrated electrolytic unit 20. In this way, the integration, manufacturability, and reliability of the electrolytic unit 20 can be further improved.

[0044] As another example, the first sealing member 30 may receive edges of the anodic poroustransmission layer 23, the anodic electrode layer 24, the membrane 25, the cathodic electrode layer 26, and the cathodic porous transmission layer 27 in a direction perpendicular to the stacking direction 28 (e.g., molding the first sealing member 30 on the edges) therein to retain the anodic porous transmission layer 23, the anodic electrode layer 24, the membrane 25, the cathodic electrode layer 26, and the cathodic porous transmission layer 27 as an integral structure. During the manufacture of the electrolytic unit 20, the first plate 21 and the second plate 22 may be disposed on two sides of the integrated structure, and the first plate 21 and the second plate 22 can be held together by the second sealing member 40 to form the integrated electrolytic unit 20. In this way, the integration, manufacturability, and reliability of the electrolytic unit 20 can be further improved.

[0045] In some embodiments, the second sealing member 40 may be vulcanized to be fixedly attached to the first plate 21 and the second plate 22 and to retain the first plate 21 and the second plate 22 as an integral structure, such that the first plate 21 and the second plate 22 retain the first sealing member 30 and the aforementioned stack therebetween. That is, the first plate 21 and the second plate 22 can be held together as an integral structure by at least the adhesion force provided by the second sealing member 40. As used herein, that the second sealing member 40 is vulcanized to be fixedly attached to the first plate 21 and the second plate 22 refers to that the second sealing member 40 is formed in such a manner that a vulcanizable sealing material is vulcanized to be fixedly attached to the first plate 21 and the second plate 22 by crosslinking. A chemical binding force and a physical adsorption force may be present at an interface between the sealing member 40 and each of the first plate 21 and the second plate 22. These two forces constitute an adhesion force that attaches the sealing member 40 to each of the first plate 21 and the second plate 22. In some instances, such an adhesion force may also be referred to as an "adhesive force".

[0046] For example, the second sealing member 40 may be formed of ethylene propylene diene monomer (EPDM) rubber, fluoro-rubber, or silicon rubber. In other words, the vulcanizable sealing material used to form the second sealing member 40 may be ethylene propylene diene monomer (EPDM) rubber, fluoro-rubber, or silicone rubber. As will be described in detail below, during the assembly of the electrolytic unit 20, the vulcanizable sealing material may be first disposed on one of the opposing surfaces of the first plate 21 and the second plate 22 or between the two plates. The sealing material may then be vulcanized to form the second sealing member 40 that retains the first plate 21 and the second plate 22 as an integral structure.

[0047] The first sealing member 30 is arranged inwardly and in direct contact with the electrolyte, while the second sealing member 40 is arranged outside the first sealing member30 and provides a second seal and an adhesion force that holds the first plate 21 and the second plate 22 together. Accordingly, the first sealing member 30 may be made of a sealing material more resistant to electrolyte corrosion. For example, it can be made of PTFE in applications where the electrolytic unit 20 is used to electrolyze water in an alkaline electrolyte. Further, the second sealing member 40 may be formed using a vulcanizable sealing material without worrying about the effects of electrolyte corrosion (although an alkaline corrosion is present here, acidic corrosion may also be present in other embodiments). This is because the second sealing member 40 is located outside the first sealing member 30 and is isolated from the aforementioned stack by the first sealing member 30. As a result, the requirements for electrolyte corrosion resistance of the sealing material used to manufacture the second sealing member 40 are not so high. Since the second sealing member 40 is not in direct contact with the electrolyte, the attachment is more reliable. The inventors have recognized and realized that by such a dual seal (or hybrid seal), a reliable seal can be provided, while the first plate 21 and the second plate 22 are reliably held together, thereby improving the reliability and service life of the electrolytic unit 20.

[0048] In some embodiments, as shown in FIGS. 2 and 3, the second sealing member 40 may be disposed in contact with the first sealing member 30 in a direction perpendicular to the stacking direction 28 to retain the first sealing member 30 together with the first plate 21 and the second plate 22. In other words, the second sealing member 40 may be vulcanized to be fixedly attached to the first sealing member 30, thereby retaining the first sealing member 30 together with the first plate 21 and the second plate 22. In this way, shifting of the first sealing member 30 can be prevented (e.g., due to a change in clamping force when the electrolytic unit 20 is mounted to the electrolytic apparatus 10 or removed from the electrolytic apparatus 10, or due to thermal expansion and contraction caused by a change in temperature during operation of the electrolytic apparatus 10), thereby further increasing the reliability of the electrolytic unit 20.

[0049] In some embodiments, the first plate 21 may be a monopole plate (i.e., an anodic plate). The first plate 21 may be formed of a metallic material or a composite material. FIGS. 4 and 5 specifically illustrate one exemplary model of the first plate 21. As shown in FIGS. 4 and 5, the first plate 21 may include a first plate body 21a and a first frame 21b surrounding the first plate body 21a in a direction perpendicular to the stacking direction 28. The first frame 21b is secured to the first plate body 21a or is integrally formed with the first plate body 21a. For example, the first frame 21b may be secured to the first plate body 21a by any suitable means or mechanism (e.g., bonding, snap-fit, welding). In this instance, the first plate body 21a andthe first frame 21b may be formed of the same or different materials. Exemplarily, the first plate body 21a may be formed of a metal material such as nickel, and the first frame 21b may be formed of a metal material or a resin material. As another example, the first frame 21b may be integrally formed with the first plate body 21a by any suitable process such as stamping and machining. In this instance, the first plate body 21a and the first frame 21b are formed of the same material.

[0050] In some embodiments, as shown in FIGS. 4 and 5, the first plate body 21a may include a recess 21c recessed therein in the stacking direction 28. The recess 21c is configured to at least partially receive the anodic porous transmission layer 23, i.e., to receive a portion of the aforementioned stack. The first frame 21b surrounds the first plate body 21a in a direction perpendicular to the stacking direction 28. Each of the anodic side outlet header channel 20a, the cathodic side outlet header channel 20b, and the electrolyte inlet header channel 20c may extend through the first frame 21b in the stacking direction 28. In other words, the first frame 21b may include a plurality of apertures extending along the stacking direction 28 through the first frame 21b, and these apertures may form a section of the anodic side outlet header channel 20a, the cathodic side outlet header channel 20b, and the electrolyte inlet header channel 20c. A groove may be provided within the recess 21c, and the electrolyte and reaction product may flow along the groove. Accordingly, the recess 21c may define an anodic side flow field. The first plate 21 may also include an input channel 21d and an output channel 21e, wherein the input channel 21d communicates the electrolyte inlet header channel 20c with the recess 21c for inputting the electrolyte from the electrolyte inlet header channel 20c into the anodic side flow field of the electrolytic unit 20, and the output channel 21e communicates the recess 21c with the anodic side outlet header channel 20a for discharging the anodic side reaction products and unconsumed electrolyte from the anodic side flow field to the anodic side outlet header channel 20a. It should be understood that the specific configuration of the first plate 21 is not to be limited thereto. For example, in some other embodiments, the first plate body 21a may be free of a recess 21c.

[0051] As shown in FIG. 2, the second plate 22 is also a monopole plate (i.e., a cathodic plate) and is similar in configuration to the first plate 21. In particular, the structure of the second plate 22 may be substantially symmetric with the structure of the first plate 21. Further, the second plate 22 may be formed from a similar material and with a similar process to the first plate 21. Similar to the first plate 21, the second plate 22 may also include a second plate body 22a and a second frame 22b surrounding the second plate body 22a in a direction perpendicular to the stacking direction 28. The second frame 22b is secured to the second plate body 22a oris integrally formed with the second plate body 22a. For the sake of brevity, the details of the similar content will not be repeated.

[0052] As shown in FIG. 2, the first sealing member 30 and the second sealing member 40 may be disposed between the first frame 21b and the second frame 22b in the stacking direction 28, respectively, and the aforementioned stack is disposed between the first plate body 21a and the second plate body 22a in the stacking direction 28. For example, the stack may be clamped between the first plate body 21a and the second plate body 22a in the stacking direction 28, and the first sealing member 30 may be clamped between the first frame 21b and the second frame 22b in the stacking direction 28. Further, the second sealing member 40 may be vulcanized to be fixedly attached to the first frame 21b and the second frame 22b and retain the first plate 21 and the second plate 22 as an integral structure.

[0053] In some embodiments, a surface of each of the first frame 21b and the second frame 22b opposite the second sealing member 40 is roughened by any suitable process. With this configuration, the adhesion force between the second sealing member 40 and the first frame 21b and the second frame 22b can be enhanced.

[0054] In some embodiments, the second sealing member 40 may provide an adhesion force of at least 10 N / mm (calculated based on peel strength) or at least 1 MPa (calculated based on shear strength) between itself and each of the first plate 21 and the second plate 22. This may be measured according to a peel strength test standard, such as GB / T 7122, ASTM D1876, and EN 1464 or any other suitable test method.

[0055] Referring back to FIG. 1, the electrolytic apparatus 10 includes a plurality of electrolytic units 20 and a grip 50. The plurality of electrolytic units 20 are stacked with each other along the stacking direction 28. The grip 50 may include a first end plate 51, a second end plate 52, and a third end plate 53. The second end plate 52 is disposed between the first end plate 51 and the third end plate 53 in the stacking direction 28. The grip 50 may also include a number of connecting rods 54 connecting the first end plate 51, the second end plate 52, and the third end plate 53. The first end plate 51 and the third end plate 53 are fixed relative to each other by the connecting rod 54. That is, both the first end plate 51 and the third end plate 53 are fixed end plates. The second end plate 52 is capable of sliding on the connecting rod 54 along the stacking direction 28 relative to the first end plate 51 and the third end plate 53. That is, the second end plate 52 is a movable end plate. The first end plate 51 and the second end plate 52 are configured to clamp the stack formed by a plurality of electrolytic units 20 in the stacking direction 28 therebetween to hold the plurality of electrolytic units 20 together. The grip 50 may further comprise a device 55 configured to drive the second end plate 52 to move in thestacking direction 28 relative to the first end plate 51. In this way, the device 55 can apply pressure to the second end plate 52, such that the second end plate 52 and the first end plate 51 apply a clamping force to the stack of the electrolytic units 20 positioned therebetween, thereby reliably holding the plurality of electrolytic units 20 together. The device 55 is capable of adjusting the clamping force applied to the stack of the electrolytic units 20 by adjusting the position of the second end plate 52 relative to the first end plate 51 in the stacking direction 28. The grip 50 may also be referred to as a "holding mechanism" or a "holding device." Such a configuration of the grip 50 of the electrolytic apparatus 10 allows for easier installation of the electrolytic unit 20 into the electrolytic apparatus 10 and disassembly and replacement of the electrolytic unit 20 from the electrolytic apparatus 10, thereby significantly improving the maintenance efficiency of the electrolytic apparatus 10 and reducing its maintenance costs.

[0056] In some embodiments, as shown in FIG. 1, the hydrogen side outlet 10a, the oxygen side outlet 10b, and the inlet 10c of the electrolytic apparatus 10 are all disposed at the first end plate 51. It will be understood that the present application is not limited thereto, and in some other embodiments, one or more of the hydrogen side outlet 10a, the oxygen side outlet 10b, and the inlet 10c may be disposed at the second end plate 52.

[0057] In some embodiments, the device 55 may be a hydraulic drive device secured to the third end plate 53 and hydraulically driving the second end plate 52 to move relative to the first end plate 51 in the stacking direction 28. The use of a hydraulic drive device provides a reliable clamping force and allows for precise adjustment of the clamping force. Moreover, the maintenance cost of a hydraulic drive device is low. It will be understood that in some other implementations, any other suitable type of device may also be employed to adjust the position of the second end plate 52 relative to the first end plate 51 in the stacking direction 28, thereby adjusting the clamping force applied by the first end plate 51 and the second end plate 52 to the stack of the electrolytic units 20.

[0058] In some embodiments, as shown in FIG. 1, a plurality of electrolytic units 20 of the electrolytic apparatus 10 may be stacked in a horizontal direction, thanks to the integrated unit design of the electrolytic unit 20 and the aforementioned configuration of the grip 50. In other words, the stacking direction 28 may be oriented horizontally relative to the direction of gravity. As described in the background, in a conventional electrolytic apparatus, components are held together by pressure. More specifically, in conventional electrolytic apparatus, each electrolytic unit must be stacked in the direction of gravity. This results in conventional electrolytic apparatus having a very large vertical height (e.g., reaching 5 meters or higher) andits time-consuming assembly and maintenance. As the stacking direction 28 in the electrolytic apparatus 10 according to the present application is oriented horizontally relative to the direction of gravity compared to a conventional electrolytic apparatus, the electrolytic apparatus 10 can have a significantly reduced vertical height and allows for convenient assembly and maintenance.

[0059] In some other embodiments, the stacking direction 28 may also be oriented parallel to the direction of gravity. In this instance, the electrolytic apparatus 10 can still be conveniently assembled and maintained.

[0060] In some embodiments, as shown in FIG. 1, a sealing gasket 60 may be provided between adjacent electrolytic units 20 to provide a seal therebetween. For example, the sealing gasket 60 may be made of a PTFE. The sealing gasket 60 is clamped between adjacent electrolytic units 20 by a clamping force applied by the second end plate 52 and the first end plate 51.

[0061] Although described herein is the use of a number of connecting rods 54 to connect the first end plate 51, the second end plate 52, and the third end plate 53, it should be understood that any other type of structure may also be employed to fix the first end plate 51 and the third end plate 53 and to allow the second end plate 52 to move relative to the first end plate 51 in the stacking direction 28.

[0062] Further, although the third end plate 53 is described herein as a fixed end plate, and the device 55 (e.g., a hydraulic drive device) is secured to the third end plate 53, it should be understood that the third end plate 53 is only one example of a fixing structure and the present application is not limited thereto. In some other embodiments, the first end plate 51 and the device 55 may be secured by any other suitable fixing structure.

[0063] The inventors have recognized and become aware of methods used to manufacture the electrolytic unit 20. In particular, the stack formed by the anodic porous transmission layer 23, the anodic electrode layer 24, the membrane 25, the cathodic electrode layer 26, and the cathodic porous transmission layer 27 stacked in sequence in the stacking direction 28, and the first sealing member 30 may be first disposed between the first plates 21 and the second plate 22 in the stacking direction 28 (the first sealing member 30 surrounds the stack in a direction perpendicular to the stacking direction 28), and then the first plate 21 and the second plate 22 may be retained as an integral structure by fixedly attaching the second sealing member 40 (e.g., by vulcanization process to be described later) to the first plate 21 and the second plate 22. In this way, the entire electrolytic unit 20 (i.e., the stack, the first plate 21, the second plate 22, the first sealing member 30, and the second sealing member 40) can be formed as an integral unit, i.e., a single piece integral structure.In various embodiments, steps of disposing the stack and the first sealing member 30 between the first plate 21 and the second plate 22 may be different depending on the aforementioned configurations of the stack and the first sealing member 30. Since these steps have been described above in connection with the different configurations of the stack and the first sealing member 30, these repeated portions are not described here. Further, since various methods of disposing the second sealing member have been described above in connection with the different configurations of the second sealing member 40, these repeated portions are not described here.

[0064] In an embodiment where the second sealing member 40 is vulcanized to be fixedly attached to the first plate 21 and the second plate 22, the vulcanizable sealing material may be disposed into the electrolytic unit 20 to form the second sealing member 40 in such a way that, the vulcanizable sealing material ("400" in FIGS. 8A to 9C) may be first disposed in the stacking direction 28 between the first plate 21 and the second plate 22 to position the sealing material on a side of the first sealing member 30 away from the stack in a direction perpendicular to the stacking direction 28, and then the sealing material may be subjected to a vulcanization process to form the second sealing member 40. As previously noted, the second sealing member 40 surrounds the first sealing member 30 in a direction perpendicular to the stacking direction 28 and is fixedly attached to the first plate 21 and the second plate 22 to retain the first plate 21 and the second plate 22 as an integral structure, such that the first plate 21 and the second plate 22 hold the first sealing member 30 and the stack therebetween.

[0065] FIGS. 8 A to 9C illustrate in greater detail two exemplary methods of disposing the vulcanizable sealing material 400 into the electrolytic unit 20 to form the second sealing member 40.

[0066] In some embodiments, as shown in FIGS. 8A and 8B, disposing the vulcanizable sealing material 400 between the first plate 21 and the second plate 22 may include the following steps: (i) holding the first plate 21 and the second plate 22 fixed relative to each other; (ii) heating the vulcanizable sealing material 400 to its melting temperature, wherein the melting temperature is lower than the vulcanization temperature of the sealing material 400; and (iii) flowing the sealing material 400 together with a vulcanizing agent to between the first plate 21 and the second plate 22.

[0067] In particular, as shown in FIGS. 8 A and 8B, the first plate 21 and the second plate 22 may be held fixed relative to each other by a mold 80. As the first plate 21 and the second plate 22 are held fixed relative to each other, the first sealing member 30 and the stack are held between the first plate 21 and the second plate 22. The mold 80 may receive edges of the firstplate 21 and the second plate 22 in a direction perpendicular to the stacking direction 28 therein to retain the first plate 21 and the second plate 22 fixed relative to each other. Further, the mold 80 may surround a structure formed by the first plate 21, the second plate 22, the first sealing member 30 and the stack in a direction perpendicular to the stacking direction 28 to form an annular chamber 81 between itself and the first plate 21, the second plate 22, and the first sealing member 30. The annular chamber 81 is located between the first plate 21 and the second plate 22 in the stacking direction 28 and is bounded by the first plate 21 and the second plate 22, and is located on a side of the first sealing member 30 away from the stack in a direction perpendicular to the stacking direction 28, surrounding the first sealing member 30 and bounded by the first sealing member 30 and the mold 80 itself. Optionally, or additionally, the first plate 21 and the second plate 22 may be held fixed relative to each other using other grips.

[0068] Subsequently, the vulcanizable sealing material 400 may be heated to its melting temperature in, for example, an injection device (not shown), where the melting temperature is lower than the vulcanization temperature of the sealing material 400. Subsequently, as indicated by the arrow in FIG. 8B, the sealing material 400 may be caused to flow together with a vulcanizing agent (and optionally an accelerator) through an injection hole 82 of the mold 80 into the annular chamber 81, i.e., between the first plate 21 and the second plate 22. This may be achieved, for example, by applying pressure to the injection device to drive the flow of the sealing material 400 and the vulcanizing agent. It will be understood that the vulcanizing agent (and optionally an accelerator) may also be mixed with the sealing material 400 prior to heating the vulcanizable sealing material 400 to its melting temperature. For example, the sealing material 400 may be in the form of particles or blocks before being heated to its melting temperature.

[0069] In this embodiment, vulcanizing the sealing material 400 to form the second sealing member 40 may comprise: heating the sealing material 400 and the vulcanizing agent to (e.g., continue to heat) the vulcanization temperature such that the sealing material 400 is vulcanized, thereby fixedly attaching the sealing material 400 between the first plate 21 and the second plate 22 to form the second sealing member 40. In particular, when the sealing material 400, heated to the melting temperature, is flowed between the first plate 21 and the second plate 22, a vulcanization reaction will not or almost not occur because the temperature of the sealing material 400 does not reach its vulcanization temperature. A vulcanization reaction occurs when the sealing material 400 and the vulcanizing agent are heated to the vulcanization temperature. Upon cooling and curing of the sealing material 400, the sealing material 400 is fixedly attached by crosslinking to the first plate 21 and the second plate 22, forming the secondsealing member 40. Exemplarily, the melting temperature of the ethylene propylene diene monomer (EPDM) rubber is approximately 150°C, and the vulcanization temperature is approximately 180°C.

[0070] By the method shown in FIGS. 8 A and 8B, a second sealing member 40 can be formed by a single vulcanization reaction. This approach can improve the integration, reliability, and manufacturing efficiency of the electrolytic unit 20.

[0071] In some other embodiments, disposing the vulcanizable sealing material 400 between the first plate 21 and the second plate 22 may include the following steps: (i) heating the vulcanizable sealing material 400 to a melting temperature of the sealing material 400, wherein the melting temperature is lower than the vulcanization temperature of the sealing material 400; (ii) flowing the sealing material 400 together with a vulcanizing agent onto one of the first plate 21 and the second plate 22; (iii) heating the sealing material 400 and the vulcanizing agent to the vulcanization temperature to vulcanize the sealing material 400 to fixedly attach the sealing material 400 to the one of the first plate 21 and the second plate 22; and (iv) holding the first plate 21 and the second plate 22 fixed relative to each other.

[0072] Exemplarily, as shown in FIG. 9A, a mold 90 may first be disposed on a structure formed by the first plate 21, the first sealing member 30, and the stack. The mold 90 may hold the first plate 21, the first sealing member 30, and the stack relatively fixed to each other. Further, the mold 90 may surround the structure formed by the first plate 21, the first sealing member 30, and the stack in a direction perpendicular to the stacking direction 28 to form an annular chamber 91 between itself and the first plate 21 and the first sealing member 30. The annular chamber 91 is positioned between the mold 90 and the first plate 21 in the stacking direction 28 and is bounded by the mold 90 and the first plate 21, and is located on a side of the first sealing member 30 away from the stack in a direction perpendicular to the stacking direction 28, surrounding the first sealing member 30 and bounded by the first sealing member 30 and the mold 90 itself.

[0073] Subsequently, the vulcanizable sealing material 400 may be heated to its melting temperature in, for example, an injection device (not shown), where the melting temperature is lower than the vulcanization temperature of the sealing material 400. Subsequently, as indicated by the arrow in FIG. 9B, the sealing material 400 may be caused to flow together with a vulcanizing agent (and optionally an accelerator) through an injection hole 92 of the mold 90 into the annular chamber 91, i.e., onto the first plate 21. This may be achieved, for example, by applying pressure to the injection device to drive the flow of the sealing material 400 and the vulcanizing agent. It should be understood that the vulcanizing agent (andoptionally an accelerator) may also be mixed with the sealing material 400 prior to heating the vulcanizable sealing material 400 to its melting temperature. For example, the sealing material 400 may be in the form of particles or blocks before being heated to its melting temperature.

[0074] Subsequently, the sealing material 400 and the vulcanizing agent may be heated to (e.g., continue to be heated to) the vulcanization temperature to vulcanize the sealing material 400 to fixedly attach the sealing material 400 to the first plate 21. In particular, when the sealing material 400, heated to the melting temperature, is flowed onto the first plate 21, a vulcanization reaction will not or almost not occur because the temperature of the sealing material 400 does not reach its vulcanization temperature. In contrast, when the sealing material 400 and the vulcanizing agent are heated to the vulcanization temperature, a vulcanization reaction occurs. Upon cooling and curing of the sealing material 400, the sealing material 400 is fixedly attached to the first plate 21 by crosslinking. For example, in this process, the sealing material 400 can be preliminarily vulcanized or vulcanized once to be fixedly attached to the first plate 21. The portion formed by the sealing material 400 during this process may be a "semifinished sealing structure."

[0075] Subsequently, the first plate 21 and the second plate 22 may be held fixed relative to each other. As shown in FIG. 9C, the mold 90 may be replaced with a mold 93. The mold 93 may hold the first plate 21 and the second plate 22 fixed relative to each other. The mold 93 may receive edges of the first plate 21 and the second plate 22 in a direction perpendicular to the stacking direction 28 therein to hold the first plate 21 and the second plate 22 fixed relative to each other. In this way, the sealing material 400 is disposed between the first plate 21 and the second plate 22. Since the first plate 21 and the second plate 22 are held fixed relative to each other, the first sealing member 30 and the stack are held between the first plate 21 and the second plate 22.

[0076] In this embodiment, vulcanizing the sealing material 400 to form the second sealing member 40 may comprise: reheating the sealing material 400 (which contains a vulcanizing agent and an optional accelerator) fixedly attached to first plate 21 to a vulcanization temperature to vulcanize the sealing material 400, thereby fixedly attaching the sealing material 400 between the first plate 21 and the second plate 22 to form the second sealing member 40. For example, in this process, the sealing material 400 may be fully vulcanized or re-vulcanized to be fixedly attached to the second plate 22.

[0077] In particular, as shown in FIG. 9C, the mold 93 may also surround a structure formed by the first plate 21, the second plate 22, the first sealing member 30, and the stack in a direction perpendicular to the stacking direction 28 to form an annular chamber 94 between itself andthe first plate 21, the second plate 22, and the first sealing members 30. The annular chamber 94 is located between the first plate 21 and the second plate 22 in the stacking direction 28 and is bounded by the first plate 21 and the second plate 22, and is located on a side of the first sealing member 30 away from the stack in a direction perpendicular to the stacking direction 28, surrounding the first sealing member 30 and bounded by the first sealing member 30 and the mold 93 itself. The aforementioned semifinished sealing structure is housed and held in the annular chamber 94. Optionally, or additionally, the first plate 21 and the second plate 22 may be held fixed relative to each other using other grips.

[0078] Subsequently, the aforementioned semifinished sealing structure may be heated again to a vulcanization temperature to vulcanize the sealing material 400, thereby fixedly attaching the sealing material 400 between the first plate 21 and the second plate 22 to form the second sealing member 40.

[0079] Although described herein is having the mold 90 form the annular chamber 91 for receiving the sealing material 400 between itself and the first plate 21 and the first sealing member 30, it is to be understood that the present application is not limited thereto. In some other embodiments, the mold 90 may be caused to form the annular chamber 91 for receiving the sealing material 400 between itself and the first plate 21. In this instance, it is not necessary to provide the first sealing member 30 on the first plate 21 when the sealing material 400 is fixedly attached to the first plate 21.

[0080] Further, although described herein is firstly fixedly attaching the sealing material 400 to the first plate 21 and subsequently fixedly attaching the sealing material 400 to the second plate 22, it is to be understood that the present application is not limited thereto. In some other embodiments, the sealing material 400 may first be fixedly attached to the second plate 22 and subsequently fixedly attached to the first plate 21 by a similar method.

[0081] The inventors have also recognized and become aware of methods for producing the electrolytic apparatus 10. In particular, as shown in FIG. 1, a plurality of electrolytic units 20 and corresponding sealing gaskets 60 may be alternately stacked along the stacking direction 28 between the second end plate 52 and the first end plate 51 of the grip 50. The second end plate 52 may then be driven to move towards the first end plate 51 in the stacking direction 28 by controlling the device 55 to increase the clamping force applied by the second end plate 52 and the first end plate 51 to the plurality of electrolytic units 20 and the corresponding sealing gaskets 60, thereby reliably holding them in place. That is, for each of the electrolytic units 20, during assembly of the electrolytic units 20 into the electrolytic apparatus 10, the second sealing member 40 applies a clamping force to retain the stack and the first sealing member ofthe electrolytic unit 20 between the second end plate 52 and the first end plate 51 by being fixedly attached to the first plate 21 and the second plate 22. In the assembled electrolytic apparatus 10, the clamping force of the first plate 21 and the second plate 22 on the stack and the first sealing member 30 is further applied by the grip 50.

[0082] The inventors have also recognized and become aware of methods for disassembling and maintaining the electrolytic apparatus 10. In particular, the second end plate 52 may be driven to move away from the first end plate 51 in the stacking direction 28 by controlling the device 55 to reduce the clamping force applied by the second end plate 52 and the first end plate 51 to the plurality of electrolytic units 20 and the corresponding sealing gaskets 60, thereby allowing the electrolytic units 20 to be removed from the electrolytic apparatus 10 if replacement is required. Subsequently, a new electrolytic unit 20 may be installed into the electrolytic apparatus 10 quickly

[0083] and the clamping force may be reapplied to hold the plurality of electrolytic units 20 and the corresponding sealing gaskets 60 together, thus resuming operation of the electrolytic apparatus 10. Replaced electrolytic units 20 may be returned to factory for repair.

[0084] The inventors have further recognized and appreciated a structure capable of enhancing the adhesion force between the second sealing member 40 and the first plate 21 and the second plate 22. FIGS. 6A to 7B show two exemplary models of electrolytic units employing such a structure, i.e., electrolytic units 620 and 720. The configurations and methods of producing and assembly of the electrolytic units 620 and 720 are similar to the configurations and methods of producing and assembly of the electrolytic units 20 shown in FIGS. 1 to 5 and 8A to 9B. Thus, for components or portions of the electrolytic units 620 and 720 that are the same as or similar to those in the electrolytic unit 20, reference numerals used to indicate the components and portions of the electrolytic unit 20 in FIGS. 1 to 5 and 8 A to 9B will be used to indicate the same or similar components and portions of the electrolytic units 620 and 720 in FIGS. 6 A to 7B. For brevity, the details of the configuration and producing and assembly methods of these same or similar components or portions will not be repeated, and the unique features of the electrolytic units 620 and 720 will be highlighted below.

[0085] As shown in FIGS. 6A and 6B, at least one (each in the drawing) of the first frame 21b of the first plate 21 and the second frame 22b of the second plate 22 of the electrolytic unit 620 may include a groove 621 recessed therein along the stacking direction 28. The groove 621 has a narrower inlet portion 621a and a wider interior portion 621b in the stacking direction 28. The second sealing member 40 includes a first portion 40a disposed in the groove 621 of the first frame 21b and a second portion 40b disposed in the groove 621 of the second frame 22b.1

[0086] The first portion 40a and the second portion 40b each fill a corresponding groove 621. It is contemplated that, during the manufacture of the electrolytic unit 620, the first portion 40a and the second portion 40b may be formed by having one portion of the sealing material 400 disposed in the groove 621 and filling the groove 621. With this configuration, an adhesion force between the second sealing member 40 and the first frame 21b and the second frame 22b can be enhanced. In particular, on one hand, the groove 621 can increase the contact area between the second sealing member 40 and the first frame 21b and the second frame 22b, thereby enhancing the adhesion force. On the other hand, the shape of the groove 621 allows the first portion 40a and the second portion 40b of the second sealing member 40 to be snapped in the corresponding groove 621 respectively, thereby enhancing the adhesion force.

[0087] As shown in FIG. 6B, when viewed in cross-section, the groove 621 may include an inlet portion 621a that is in a narrow neck shape, and an interior portion 621b that is in a wide and rounded shape. It should be understood that the shape of the groove 621 is not limited thereto. In some other embodiments, the cross-section of the groove 621 may be in a dovetail (inverted trapezoidal) shape or any other suitable shape.

[0088] In some embodiments, the groove 621 may be continuous annular. In some other embodiments, the groove 621 may be intermittent (e.g., including a single section or multiple separate sections). For example, the groove 621 may be provided at a location where a higher adhesion force is required.

[0089] As shown in FIGS. 7A and 7B, the first frame 21b of the first plate 21 of the electrolytic unit 720 may include a first body 721a and a first annular protrusion 721b (one in the drawing) projecting from the first body 721a towards the second frame 22b of the second plate 22 along the stacking direction 28, and the second frame 22b of the second plate 22 may include a second body 722a and a second annular protrusion 722b (one in the drawing) projecting from the second body 722a towards the first frame 21b of the first plate 21 along the stacking direction28. The first annular protrusion 721b and the second annular protrusion 722b are staggered from each other in the stacking direction 28. The first annular protrusion 721b and the second annular protrusion 722b are spaced apart from each other in a direction perpendicular to the stacking direction 28 to define a gap therebetween. The second sealing member 40 is disposed in the gap and is disposed between a top of the first annular protrusion 721b and the second body 722a of the second frame 22b, and between a top of the second annular protrusion 722b and the first body 721a of the first frame 21b. It is contemplated that, during the manufacture of the electrolytic unit 720, the second sealing member 40 may be formed by disposing the sealing material 400 in the gap and between the top of the first annular protrusion 721b and the secondbody 722a of the second frame 22b, and between the top of the second annular protrusion 722b and the first body 721a of the first frame 21b. With this configuration, an adhesion force between the second sealing member 40 and the first frame 21b and the second frame 22b can be enhanced. In particular, the first annular protrusion 721b and the second annular protrusion 722b can increase the contact area of the second sealing member 40 with the first frame 21b and the second frame 22b, thereby enhancing the adhesion force. Further, the first annular protrusion 721b and the second annular protrusion 722b enable the second sealing member 40 to form a labyrinth sealing structure in a direction perpendicular to the stacking direction 28, which increases the overall length of the fluid movement path from the inside to the outside of the electrolytic unit 20, thereby improving the sealing effect. Further, the first annular protrusion 721b and the second annular protrusion 722b can reliably retain the second sealing member 40 in place, particularly prevent the second sealing member 40 from deforming or displacing in a direction perpendicular to the stacking direction 28, thereby improving the sealing effect.

[0090] As shown in FIG. 7B, the first annular protrusion 721b and the second annular protrusion 722b may have a trapezoidal shape, respectively, when viewed in cross-section. It should be understood that the cross-sectional shape of the first annular protrusion 721b and the second annular protrusion 722b is not limited thereto. In some other embodiments, the cross-sections of the first annular protrusion 721b and the second annular protrusion 722b may be triangular, rectangular, semicircular, or any other suitable shape.

[0091] Although only one first annular protrusion 721b and one second annular protrusion 722b are shown in FIGS. 7A and 7B, it should be understood that the first frame 21b of the first plate 21 and the second frame 22b of the second plate 22 of the electrolytic unit 720 may have more than one annular protrusion, respectively. That is, the first frame 21b may include at least one first annular protrusion 721b projecting from the first body 721a towards the second frame 22b along the stacking direction 28, and the second frame 22b may include at least one second annular protrusion 722b projecting from the second body 722a towards the first frame 21b along the stacking direction 28. The at least one first annular protrusion 721b and the at least one second annular protrusion 722b are staggered from one another in the stacking direction 28 and are arranged alternately in a direction perpendicular to the stacking direction 28. Adjacent first annular protrusion 721b and second annular protrusion 722b are spaced apart from each other in a direction perpendicular to the stacking direction 28 to define a gap therebetween. The second sealing member 40 is disposed in the gap and between a top of at least one first annular protrusion 721b and the second body 722a of the second frame 22b, andbetween a top of at least one second annular protrusion 722b and the first body 721a of the first frame 21b. With this configuration, the adhesion force between the second sealing member 40 and the first frame 21b and the second frame 22b can be enhanced, and the sealing effect of the second sealing member 40 can be improved.

[0092] Although described above is the second sealing member 40 being vulcanized to be fixedly attached to the first plate 21 and the second plate 22 and to retain the first plate 21 and the second plate 22 as an integral structure, it should be understood that the second sealing member 40 may be fixedly attached to the first plate 21 and the second plate 22 by any other suitable means to retain the first plate 21 and the second plate 22 as an integral structure. For example, the second sealing member 40 may be thermally fused or ultrasonically welded to the first plate 21 and the second plate 22. As another example, the second sealing member 40 may have a stiffer body and a protrusion projecting from the body (e.g., the first portion 40a and the second portion 40b shown in FIG. 6B). The outer side of the protrusion may be provided with a deformation layer. Exemplarily, the body and the protrusion of the second sealing member 40 may be formed of a resin material. The deformation layer is made of a material that is less rigid and more elastic than the resin material, such as fluoro-rubber, ethylene propylene diene monomer (EPDM) rubber, silicone rubber, and polytetrafluoroethylene. The protrusion of the second sealing member 40 may be snapped directly into the grooves 621 of the first plate 21 and the second plate 22 by way of the deformation layer to achieve a reliable mechanical attachment and tight sealing between the first plate 21 and the second plate 22. As another example, the second sealing member 40 may be bonded between the first plate 21 and the second plate 22 to be fixedly attached to the first plate 21 and the second plate 22, thereby retaining the first plate 21 and the second plate 22 as an integral structure. Exemplarily, the second sealing member 40 may be formed of a sealant or an adhesive film. As yet another example, the second sealing member 40 may be fixedly attached to the first plate 21 and the second plate 22 by a hot melt stud. Exemplarily, the first plate 21 and the second plate 22 may each be perforated along the stacking direction 28, and the hot melt stud may extend through the hole and be hot-melted to be fixed in place to fixedly attach the second sealing member 40 to the first plate 21 and the second plate 22.

[0093] Further, although the configuration of the first plate 21 and the second plate 22 is described herein with a monopole plate as an example, it should be understood that the first plate 21 and the second plate 22 may also be bipolar plates, respectively, and are also applicable to the electrolytic unit 20 of the present application. In this instance, the electrolytic apparatus 10 may comprise at least one additional electrolytic unit, which is arranged alternately with theelectrolytic unit 20 in the electrolytic apparatus 10 along the stacking direction 28. Each of the additional electrolytic units may include a stack formed by an anodic porous transmission layer, an anodic electrode layer, a membrane (here, a diaphragm), a cathodic electrode layer, and a cathodic porous transmission layer, and a sealing member (e.g., the aforementioned first sealing member 30 or other sealing gasket). The stack and sealing member of each additional electrolytic unit may be held in place by a bipolar plate of adjacent electrolytic units 20. Accordingly, in the present application, the bipolar and monopole plates may be summarized as a plate.

[0094] Further, although described herein is the electrolytic unit 20 used to electrolyze water in the alkaline electrolyte, it is understood that the electrolytic apparatus 10 and the electrolytic unit 20 thereof, or variations thereof, according to the present application, are capable of being used in other types of electrolytic systems, such as PEM electrolytic systems and AEM electrolytic systems. In applications where the electrolytic unit 20 is used in the PEM electrolytic system, the membrane 25 is a protic exchange membrane. In applications where the electrolytic unit 20 is used in the AEM electrolytic system, the membrane 25 is an anion exchange membrane. Further, the configuration of the inlet header channel and the outlet header channel may change accordingly.

[0095] In the present application, the terms "first," "second," and the like are only used to distinguish one component, line, or mode from another component, line, or mode, and these components, lines, and modes are not to be limited by such terms.

[0096] The present application has been described in detail in conjunction with specific examples. It is evident that the above description and the examples illustrated in the accompanying drawings are all to be understood as exemplary and not as limiting the present application. Those skilled in the art may make various modifications or alterations without departing from the spirit of the present application, and such modifications or alterations are not to be excluded from the scope of the present application.

Claims

Claims1. An electrolytic unit (20, 620, 720) for an electrolytic apparatus (10), comprising: a first plate (21) and a second plate (22);a stack formed by an anodic porous transmission layer (23), an anodic electrode layer (24), a membrane (25), a cathodic electrode layer (26), and a cathodic porous transmission layer (27) stacked in sequence along a stacking direction (28), the stack being disposed between the first plate and the second plate in the stacking direction; anda first sealing member (30) and a second sealing member (40) respectively disposed between the first plate and the second plate in the stacking direction, the first sealing member surrounding the stack in a direction perpendicular to the stacking direction, and the second sealing member being disposed on a side of the first sealing member away from the stack in the direction perpendicular to the stacking direction, the second sealing member being vulcanized to be fixedly attached to the first plate and the second plate and retain the first plate and the second plate as an integral structure, such that the first sealing member and the stack are maintained between the first plate and the second plate.

2. The electrolytic unit according to claim 1, wherein the first sealing member at least receives edges of the anodic electrode layer, the membrane, and the cathodic electrode layer in the direction perpendicular to the stacking direction therein to retain at least the anodic electrode layer, the membrane, and the cathodic electrode layer as an integral structure.

3. The electrolytic unit according to claim 2, wherein the first sealing member receives edges of the anodic porous transmission layer, the anodic electrode layer, the membrane, the cathodic electrode layer, and the cathodic porous transmission layer in the direction perpendicular to the stacking direction therein to retain the anodic porous transmission layer, the anodic electrode layer, the membrane, the cathodic electrode layer, and the cathodic porous transmission layer as an integral structure.

4. The electrolytic unit according to claim 1, wherein:the stack and the first sealing member are respectively clamped between the first plate and the second plate in the stacking direction; and / orthe first sealing member isolates the second sealing member from the stack; and / orthe electrolytic unit further comprises an electrolyte inlet header channel (20c), an anodic side outlet header channel (20a), and a cathodic side outlet header channel (20b), each of the electrolyte inlet header channel, the anodic side outlet header channel, and the cathodic side outlet header channel extending through the first sealing member along the stacking direction.

5. The electrolytic unit according to claim 1, wherein the electrolytic unit is used to electrolyze water in an alkaline electrolyte, and the first sealing member is made of a sealing material resistant to alkaline electrolyte corrosion.

6. The electrolytic unit according to any one of claims 1 to 5, wherein the second sealing member is formed of ethylene propylene diene monomer (EPDM) rubber, fluororubber, or silicone rubber.

7. The electrolytic unit according to any one of claims 1 to 5, wherein the second sealing member is disposed in contact with the first sealing member in the direction perpendicular to the stacking direction to hold the first sealing member with the first and second pole plates.

8. The electrolytic unit according to any one of claims 1 to 5, wherein:the first plate comprises a first plate body (21a) and a first frame (21b) surrounding the first plate body in the direction perpendicular to the stacking direction, the first frame being fixed to the first plate body or integrally formed with the first plate body;the second plate comprises a second plate body (22a) and a second frame (22b) surrounding the second plate body in the direction perpendicular to the stacking direction, the second frame being fixed to the second plate body or integrally formed with the second plate body; andthe first sealing member and the second sealing member are respectively disposed between the first frame and the second frame in the stacking direction.

9. The electrolytic unit according to claim 8, wherein:one or both of the first frame and the second frame include a groove (621) recessed therein along the stacking direction, the groove having a narrower inlet portion (621a) and a wider interior portion (621b) in the stacking direction, a portion (40a, 40b) of the second sealingmember being disposed in the groove and filling the groove; and / orthe first frame includes a first body (721a) and at least one first annular protrusion (721b) projecting from the first body towards the second frame in the stacking direction, and the second frame includes a second body (722a) and at least one annular protrusion (722b) projecting from the second body towards the first frame in the stacking direction, the at least one first annular protrusion and the at least one second annular protrusion being staggered from each other in the stacking direction and alternately arranged in the direction perpendicular to the stacking direction, adjacent first annular protrusion and second annular protrusion being spaced apart from each other in the direction perpendicular to the stacking direction to define a gap therebetween, the second sealing member being disposed in the gap and between a top of the at least one first annular protrusion and the second body of the second frame, and between a top of the at least one second annular protrusion and the first body of the first frame; and / ora surface of each of the first frame and the second frame opposite the second sealing member is roughened; and / orthe second sealing member provides an adhesion force of at least 10 N / mm or at least 1 MPa between the second sealing member and each of the first and second plates.

10. An electrolytic device (10), comprising:a plurality of electrolytic units (20, 620, 720), each of the plurality of electrolytic units being the electrolytic unit according to any one of claims 1 to 9, and the plurality of electrolytic units stacked in the stacking direction (28); anda first end plate (51) and a second end plate (52) clamping the plurality of electrolytic units therebetween in the stacking direction to hold the plurality of electrolytic units together.

11. The electrolytic device according to claim 10, whereinthe electrolytic apparatus further comprises a hydraulic drive device (55), the first end plate being a fixed end plate and the second end plate being a movable end plate and capable of being driven by the hydraulic drive device to move in the stacking direction relative to the first end plate; and / orthe stacking direction is oriented horizontally relative to a direction of gravity.

12. A method for producing an electrolytic unit (20, 620, 720), comprising: disposing a stack formed by stacking an anodic porous transmission layer (23), an anodicelectrode layer (24), a membrane (25), a cathodic electrical layer (26), and a cathodic porous transmission layer (27) in sequence along a stacking direction (28) and a first sealing member (30) between a first plate (21) and a second plate (22) in the stacking direction, wherein the first sealing member surrounding the stack in a direction perpendicular to the stacking direction;disposing a vulcanizable sealing material (400) between the first plate and the second plate in the stacking direction such that the sealing material is on a side of the first sealing member away from the stack in the direction perpendicular to the stacking direction; and vulcanizing the sealing material to form a second sealing member (40), wherein the second sealing member surrounds the first sealing member in the direction perpendicular to the stacking direction and is vulcanized to be fixedly attached to the first plate and the second plate and retain the first plate and the second plate as an integral structure, such that the first sealing member and the stack are maintained between the first plate and the second plate.

13. The method according to claim 12, wherein:disposing the sealing material between the first plate and the second plate comprises: (i) holding the first plate and the second plate fixed relative to each other; (ii) heating the sealing material to a melting temperature of the sealing material, wherein the melting temperature is lower than a vulcanization temperature of the sealing material; and (iii) flowing the sealing material together with a vulcanizing agent to between the first plate and the second plate; and vulcanizing the sealing material to form the second sealing member comprises: heating the sealing material and the vulcanizing agent to the vulcanization temperature to vulcanize the sealing material, thereby fixedly attaching the sealing material between the first plate and the second plate.

14. The method according to claim 12, wherein:disposing the sealing material between the first plate and the second plate comprises: (i) heating the sealing material to a melting temperature of the sealing material, wherein the melting temperature is lower than a vulcanization temperature of the sealing material; (ii) flowing the sealing material together with a vulcanizing agent onto one of the first plate and the second plate; (iii) heating the sealing material and the vulcanizing agent to the vulcanization temperature to vulcanize the sealing material to fixedly attach the sealing material to the one of the first plate and the second plate; and (iv) holding the first plate and the second plate fixed relative to each other; andvulcanizing the sealing material to form the second sealing member comprises: heatingthe sealing material to be fixedly attached to the one of the first plate and the second plate and the vulcanizing agent to the vulcanization temperature to vulcanize the sealing material, thereby fixedly attaching the sealing material to between the first plate and the second plate.

15. The method according to claim 12, wherein:the first plate comprises a first plate body (21a) and a first frame (21b) surrounding the first plate body in the direction perpendicular to the stacking direction, the first frame being fixed to the first plate body or integrally formed with the first plate body;the second plate comprises a second plate body (22a) and a second frame (22b) surrounding the second plate body in the direction perpendicular to the stacking direction, the second frame being fixed to the second plate body or integrally formed with the second plate body; anddisposing the sealing material between the first plate and the second plate comprises disposing the sealing material between the first frame and the second frame in the stacking direction.

16. The method according to claim 15, wherein:one or both of the first frame and the second frame include a groove (621) recessed therein along the stacking direction, the groove having a narrower inlet portion (621a) and a wider interior portion (621b) in the stacking direction, disposing the sealing material between the first frame and the second frame including disposing a portion of the sealing material in the groove and filling the groove; and / orthe first frame includes a first body (721a) and at least one first annular protrusion (721b) projecting from the first body towards the second frame in the stacking direction, and the second frame includes a second body (722a) and at least one annular protrusion (722b) projecting from the second body towards the first frame in the stacking direction, the at least one first annular protrusion and the at least one second annular protrusion being staggered from each other in the stacking direction and alternately arranged in the direction perpendicular to the stacking direction, adjacent first annular protrusion and second annular protrusion being spaced apart from each other in the direction perpendicular to the stacking direction to define a gap therebetween, disposing the sealing material between the first frame and the second frame including disposing the sealing material in the gap and between a top of the at least one first annular protrusion and the second body of the second frame, and between a top of the at least one second annular protrusion and the first body of the first frame; and / orthe sealing material is ethylene propylene diene monomer (EPDM) rubber, fluoro-rubber, or silicone rubber.

17. The method according to any one of claims 12 to 16, wherein the first sealing member at least receives edges of the anodic electrode layer, the membrane, and the cathodic electrode layer in the direction perpendicular to the stacking direction therein to retain at least the anodic electrode layer, the membrane, and the cathodic electrode layer as an integral structure.

18. The method according to claim 17, wherein the first sealing member receives edges of the anodic porous transmission layer, the anodic electrode layer, the membrane, the cathodic electrode layer, and the cathodic porous transmission layer in the direction perpendicular to the stacking direction therein to retain the anodic porous transmission layer, the anodic electrode layer, the membrane, the cathodic electrode layer, and the cathodic porous transmission layer as an integral structure.

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