Electrolytic cell and electrolysis device

Abstract

The present disclosure proposes an electrolytic cell and an electrolytic device. The electrolytic cell comprises: a main pole frame having a first surface and a second surface opposite in a thickness direction, and an inner side wall and an outer side wall spaced apart in a lateral direction, the inner side wall defining a central hole extending through the main pole frame in the thickness direction and having a stepped portion opposite the second surface in the thickness direction; a bipolar plate abutting against the first surface or the second surface; a diaphragm and a sub-pole frame accommodated in the central hole, the sub-pole frame being annular and pushing the diaphragm against the stepped portion, so that the central hole is divided by the diaphragm into a first chamber leading to the first surface and a second chamber leading to the second surface; a first porous transport layer and a first electrode layer accommodated in the first chamber; and a second porous transport layer and a second electrode layer accommodated in the second chamber.

Description

Technical Field

[0001] This disclosure relates to the field of electrolysis technology, and more specifically, to an electrolysis unit for electrolyzing water to produce hydrogen and oxygen, and an electrolysis apparatus comprising a plurality of electrolysis units stacked together. Background Technology

[0002] An electrolysis system is an electrochemical device that converts electrical energy into chemical energy to produce hydrogen. It is widely used in the hydrogen production industry, especially in fields requiring high-purity hydrogen, such as chemical, electronics, and food processing. Furthermore, with the development of renewable energy, electrolysis systems are also being used to convert renewable energy sources such as wind and solar power into chemical energy for storage—that is, the production of green hydrogen.

[0003] Taking an alkaline solution electrolyzer as an example, after supplying direct current to the electrolyzer, water molecules gain electrons at the cathode electrode, thus being reduced to hydrogen molecules and hydroxide ions. The hydroxide ions can penetrate the membrane to reach the anode electrode, where they lose electrons and are oxidized to oxygen molecules and water molecules. In practical applications, multiple electrolyzers are often stacked for use, requiring precise alignment during assembly. However, due to the low modularity of existing electrolyzers, precise alignment is difficult during assembly. Furthermore, the cells often need to be arranged and stacked vertically, while the stack needs to be placed horizontally during operation. Therefore, assembling existing electrolyzer stacks is challenging and inefficient.

[0004] Therefore, there is an urgent need in this field for a technical solution that can improve the modularity of electrolytic cells to reduce their production and maintenance costs. Utility Model Content

[0005] To address the problems in the prior art, this disclosure proposes an improved electrolysis unit comprising: a main electrode frame having a first surface and a second surface opposite in the thickness direction, and inner and outer sidewalls spaced apart in the transverse direction, the inner sidewalls defining a central hole extending through the main electrode frame in the thickness direction and having a stepped portion opposite in the thickness direction to the second surface; a bipolar plate abutting the first surface or the second surface; a diaphragm and a secondary electrode frame housed in the central hole, the secondary electrode frame being annular and pushing the diaphragm against the stepped portion such that the central hole is divided by the diaphragm into a first chamber leading to the first surface and a second chamber leading to the second surface; a first porous transport layer housed in the first chamber and a first electrode layer located between the diaphragm and the first porous transport layer; and a second porous transport layer housed in the second chamber and a second electrode layer located between the diaphragm and the second porous transport layer.

[0006] According to an optional embodiment of this disclosure, the main pole frame is further provided with a plurality of sealing grooves and includes a plurality of sealing rings, wherein each sealing ring is held by a corresponding sealing groove, and the natural height of each sealing ring is greater than the depth of the corresponding sealing groove.

[0007] According to an optional embodiment of the present disclosure, the main pole frame is further provided with a plurality of outer holes extending through the thickness direction, the plurality of sealing grooves including a first outer sealing groove recessed from the first surface and a second outer sealing groove recessed from the second surface, each of the first outer sealing groove and the second outer sealing groove being arranged to surround the central hole and the plurality of outer holes.

[0008] According to an optional embodiment of this disclosure, the plurality of outer holes include a plurality of first outer holes communicating with the first chamber and a plurality of second outer holes communicating with the second chamber, and the plurality of sealing grooves further include a plurality of first inner sealing grooves recessed from the first surface and a plurality of second inner sealing grooves recessed from the second surface, wherein each first inner sealing groove is arranged to surround one of the plurality of second outer holes, and each second inner sealing groove is arranged to surround one of the plurality of first outer holes.

[0009] According to an optional embodiment of this disclosure, the main pole frame is further provided with a plurality of first distribution grooves recessed from the first surface, and the secondary pole frame is provided with a plurality of connecting grooves, wherein each first outer hole communicates with the first chamber through a corresponding first distribution groove and a connecting groove, and the first outer sealing groove is further arranged to surround the plurality of first distribution grooves.

[0010] According to an optional embodiment of the present disclosure, the main pole frame is further provided with a plurality of second distribution grooves recessed from the second surface, wherein each second outer hole communicates with the second chamber through a corresponding second distribution groove, and the second outer sealing groove is further arranged to surround the plurality of second distribution grooves.

[0011] According to an alternative embodiment of this disclosure, the plurality of sealing grooves further include a central sealing groove recessed from the stepped portion, the central sealing groove being arranged to surround the second chamber.

[0012] According to an optional embodiment of this disclosure, the difference between the natural height of at least one of the plurality of sealing rings and the depth of the corresponding sealing groove is greater than 25% of the natural height of the sealing ring; and / or, the cross-sectional area of ​​at least one of the plurality of sealing rings is less than 90% of the cross-sectional area of ​​the corresponding sealing groove; and / or, at least one of the plurality of sealing grooves has a sidewall inclined relative to the thickness direction, such that the sealing groove widens as it approaches its bottom.

[0013] According to an alternative embodiment of the present disclosure, the second chamber extends along the thickness direction from an internal opening located at the stepped portion to an external opening located at the second surface, and the main pole frame further includes a retaining structure disposed on the inner sidewall, the retaining structure being configured to reduce the lateral dimension of the second chamber and abut against the second porous transmission layer.

[0014] According to an alternative embodiment of this disclosure, the bipolar plate abuts against the first surface and covers the central hole, such that the diaphragm and the sub-electrode frame are sandwiched between the bipolar plate and the stepped portion.

[0015] According to one alternative embodiment of this disclosure, the retaining structure is formed by a flange projecting from the inner sidewall in a lateral direction; or, the retaining structure is formed by an inclined portion of the inner sidewall, the inclined portion being configured to reduce the lateral dimension of the second chamber as it approaches the second surface.

[0016] According to an optional embodiment of this disclosure, the main electrode frame further includes a plurality of positioning protrusions protruding from the first surface and a plurality of positioning grooves recessed from the second surface, wherein each positioning groove is aligned with a corresponding positioning protrusion along the thickness direction and is shaped to allow the positioning protrusion to be inserted, and the bipolar plate is provided with a plurality of positioning holes, wherein each positioning hole allows a corresponding positioning protrusion to pass through.

[0017] According to an alternative embodiment of this disclosure, at least one of the plurality of positioning protrusions is configured as a locking protrusion having a neck and an end that expands laterally relative to the neck, the end being connected to the first surface via the neck, and at least one of the plurality of positioning holes is configured as a locking hole having a narrow portion that allows only the neck to pass through and a wide portion that allows both the neck and the end to pass through.

[0018] According to an alternative embodiment of this disclosure, the sub-electrode frame is provided with an auxiliary sealing groove, the auxiliary sealing groove holding an auxiliary sealing ring and being arranged to surround the first chamber, and the auxiliary sealing ring being configured to be sandwiched between the diaphragm and the sub-electrode frame; and / or, the sub-electrode frame is made of an elastic material.

[0019] Similarly, in order to address the problems in the prior art described above, this disclosure also proposes an improved electrolysis apparatus comprising a plurality of electrolysis units as described herein, stacked together along the thickness direction.

[0020] This disclosure may be embodied in the illustrative embodiments shown in the accompanying drawings. However, it should be noted that the drawings are merely illustrative, and any variations contemplated under the teachings of this disclosure should be considered to be included within the scope of this disclosure. Attached Figure Description

[0021] The accompanying drawings illustrate exemplary embodiments of this disclosure. These drawings should not be construed as necessarily limiting the scope of this disclosure, wherein: Figure 1 This is a schematic exploded perspective view of an electrolysis unit according to one embodiment of the present disclosure; Figure 2 yes Figure 1 A schematic rear exploded perspective view of the electrolysis unit shown; Figure 3 yes Figure 1 and Figure 2 A schematic front view of the assembled electrolysis unit shown; Figure 4 yes Figure 1 and Figure 2 A schematic rear view of the electrolysis unit shown; Figure 5 It is along Figure 3 A schematic cross-sectional view of the electrolysis unit taken from line VV in the diagram; Figure 6 It is along Figure 3 A schematic cross-sectional view of the electrolysis unit taken by line VI-VI in the diagram; Figure 7 yes Figures 1-6 A schematic formal diagram of the bipolar plates of the electrolysis unit shown; and Figure 8 It includes multiple stacked together Figures 1-6 A schematic cross-sectional view of the electrolysis unit shown. Detailed Implementation

[0022] Further features and advantages of this disclosure will become more apparent from the following description with reference to the accompanying drawings. Exemplary embodiments of this disclosure are shown in the drawings, and the drawings are not necessarily drawn to scale. However, this disclosure can be implemented in many different forms and should not be construed as necessarily limited to the exemplary embodiments shown herein. Rather, these exemplary embodiments are provided merely to illustrate this disclosure and to convey the spirit and essence of this disclosure to those skilled in the art.

[0023] This disclosure aims to provide an improved electrolysis unit and an electrolysis apparatus comprising multiple electrolysis units stacked together. The electrolysis unit according to this disclosure has a high level of modularity due to its novel design, thereby facilitating assembly, disassembly, and reassembly, significantly reducing the production and maintenance costs of the electrolysis unit. In particular, the novel design of the electrolysis unit according to this disclosure provides a mono-cell structure, which allows the electrolysis unit to be placed and transported as a whole, enabling multiple electrolysis units to be stacked not only vertically but also horizontally. This effectively improves the assembly efficiency of the electrolysis apparatus, thereby significantly reducing its production and maintenance costs. Furthermore, the novel design of the electrolysis unit according to this disclosure also contributes to improved assembly accuracy of the electrolysis apparatus, thus improving not only its assembly efficiency but also its reliability. Furthermore, the novel design of the electrolysis unit according to this disclosure can improve the isolation between the cathode chamber and the anode chamber, thereby more reliably preventing the mixing of oxygen in the cathode chamber with hydrogen in the anode chamber. This not only improves the purity of the produced hydrogen and oxygen, but also reduces the risk of explosion from the mixing of hydrogen and oxygen, thereby improving the safety of the electrolysis unit and the electrolysis apparatus.

[0024] The following describes in detail, with reference to the accompanying drawings, various optional but non-limiting embodiments of the electrolysis unit and electrolysis apparatus according to this disclosure. It should be noted that although the teachings of this disclosure are described below using an alkaline water electrolysis apparatus (i.e., an electrolysis apparatus using an alkaline solution such as sodium hydroxide or potassium hydroxide as the electrolyte) as an example, those skilled in the art will understand that the teachings of this disclosure are equally applicable to other types of electrolysis apparatuses, such as proton exchange membrane (PEM) electrolysis apparatuses, solid polymer anion exchange membrane (AEM) electrolysis apparatuses, etc. Therefore, the specific type of electrolysis apparatus should not constitute a limitation on the scope of protection of this disclosure.

[0025] refer to Figure 1 and Figure 2 ,in, Figure 1 A schematic exploded perspective view of an electrolysis unit 10 according to one embodiment of the present disclosure is shown, and Figure 2 It shows Figure 1 A schematic exploded rear view of the electrolysis unit 10 shown. Figure 1 and Figure 2 As shown, the electrolytic unit (also referred to as a single electrolytic cell) 10 generally includes a main electrode frame 100 (e.g., injection molded from a resin material such as PPS, PEI, PSU, PPSU), which has a first surface 110 and a second surface 120 opposite to each other along the thickness direction TT'. Additionally, the main electrode frame 100 also has inner sidewalls 130 and outer sidewalls 140 spaced apart along a transverse direction transverse to (or perpendicular to) the thickness direction TT', wherein the inner sidewall 130 defines a central hole 131 extending along the thickness direction TT' through the main electrode frame 100 (i.e., extending from the first surface 110 to the second surface 120). Specifically, as... Figure 1 and Figure 2 As shown, the inner sidewall 130 does not extend entirely along the thickness direction TT', but has a stepped portion 132 that protrudes inward along the transverse direction and is arranged around the entire circumference. That is, the stepped portion 132 extends in the transverse direction and forms a complete annular shape. The inner sidewall 130 also has a first portion 133 and a second portion 134 extending along the thickness direction TT', wherein the first portion 133 extends from the stepped portion 132 to the first surface 110, and the second portion 134 extends from the stepped portion 132 to the second surface 120. In addition, the stepped portion 132 is formed by offsetting the first portion 133 outward relative to the second portion 134 in the transverse direction. Therefore, the stepped portion 132 is not only spaced apart from both the first surface 110 and the second surface 120 along the thickness direction TT', but is also arranged so that it is opposite to the second surface 120 along the thickness direction TT'. This also makes the transverse dimension of the hole segment of the central hole 131 defined by the first portion 133 larger than the transverse dimension of the hole segment of the central hole 131 defined by the second portion 134. Additionally, the electrolysis unit 10 also includes a bipolar plate 200 stacked with the main electrode frame 100 along a stacking direction SS', wherein the stacking direction SS' is intended to be in the same direction as the thickness direction TT', and the bipolar plate 200 is arranged to abut against a first surface 110 or a second surface 120 of the main electrode frame 100 such that the bipolar plate 200 can cover the opening of the central hole 131 on the first surface 110 or the second surface 120.

[0026] Continue to refer to Figure 1 and Figure 2The electrolysis unit 10 also includes a diaphragm 310 and a secondary electrode frame 320 housed in the central hole 131 of the main electrode frame 100. The diaphragm 310 and the secondary electrode frame 320 can enter the central hole 131 through an opening on the first surface 110. Specifically, the diaphragm 310 is arranged in the central hole 131 to abut against a stepped portion 132 of the inner sidewall 130 of the main electrode frame 100 along its entire circumference. That is, the diaphragm 310 abuts against the stepped portion 132 along its entire edge on one side, thereby forming an annular contact area arranged around the central hole 131 along its entire circumference between the diaphragm 310 and the stepped portion 132. Furthermore, the generally annular sub-pole frame 320 abuts against the diaphragm 310 along its entire circumference on the side opposite to the stepped portion 132 and is aligned with the stepped portion 132 along its thickness direction TT'. That is, the diaphragm 310 abuts against the sub-pole frame 320 along its entire edge on the other side, thus forming another annular contact area between the diaphragm 310 and the sub-pole frame 320, also arranged around the central hole 131 along its entire circumference. Since the sub-pole frame 320 is aligned with the stepped portion 132 along its thickness direction TT', the two annular contact areas formed between the diaphragm 310 and the stepped portion 132 and the sub-pole frame 320 are also aligned with each other along their thickness direction TT'. Therefore, in the above configuration, the sub-pole frame 320 can push the diaphragm 310 to abut against the stepped portion 132, thereby forming the aforementioned two annular contact areas aligned with each other along their thickness direction TT'. Specifically, when the bipolar plate 200 abuts against the first surface 110, the bipolar plate 200 can push the diaphragm 310 against the stepped portion 132 via the secondary pole frame 320, so that both the diaphragm 310 and the secondary pole frame 320 are sandwiched between the bipolar plate 200 and the stepped portion 132. Furthermore, with the above configuration, the central hole 131 is divided by the diaphragm 310 into a first chamber 131a and a second chamber 131b located on both sides of the diaphragm 310. Figure 4 (as indicated by the reference numeral), wherein the first chamber 131a is surrounded (or defined by) the sub-pole frame 320, and the second chamber 131b is surrounded (or defined by) the inner wall 130 (more specifically, the second portion 134 of the inner wall 130) of the main pole frame 100, and the first chamber 131a and the second chamber 131b are effectively isolated from each other by means of the two annular contact areas formed between the diaphragm 310 and the step portion 132 and the sub-pole frame 320.

[0027] like Figure 1 and Figure 2As shown, the electrolysis unit 10 further includes a first electrode layer 410 and a first porous transport layer 510 disposed in a first chamber 131a, and a second electrode layer 420 and a second porous transport layer 520 disposed in a second chamber 131b. More specifically, the first electrode layer 410 and the first porous transport layer 510 are stacked in the first chamber 131a along the stacking direction SS', and the first electrode layer 410 is disposed between the first porous transport layer 510 and the diaphragm 310 and abuts against the first porous transport layer 510 and the diaphragm 310 on both sides, respectively. Similarly, the second electrode layer 420 and the second porous transport layer 520 are stacked in the second chamber 131b along the stacking direction SS', and the second electrode layer 420 is disposed between the second porous transport layer 520 and the diaphragm 310 and abuts against the second porous transport layer 520 and the diaphragm 310 on both sides, respectively. Specifically, when the bipolar plate 200 abuts against the first surface 110, the bipolar plate 200 can push the first electrode layer 410 against the diaphragm 310 through the first porous transport layer 510. In the electrolysis apparatus, the bipolar plate 200 of another electrolysis unit 10 adjacent to this electrolysis unit 10 can abut against the second surface 120 of the main electrode frame 100 of that electrolysis unit 10, and push the second electrode layer 420 against the diaphragm 310 through the second porous transport layer 520. Furthermore, the first electrode layer 410 and the first porous transport layer 510 can respectively serve as the anode electrode layer and the anode porous transport layer, in which case the first chamber 131a can be used as the anode chamber. Simultaneously, the second electrode layer 420 and the second porous transport layer 520 can respectively serve as the cathode electrode layer and the cathode porous transport layer, in which case the second chamber 131b can be used as the cathode chamber. Of course, the above configuration is merely exemplary. In other embodiments, the opposite configuration may be adopted, in which the first chamber 131a is used as the cathode chamber and the second chamber 131b is used as the anode chamber.

[0028] In the above configuration, each component of the electrolysis unit 10 is attached to or housed in the main electrode frame 100. This allows the electrolysis unit 10 to be operated by manipulating the main electrode frame 100 (e.g., by handling or installing the main electrode frame 100). This significantly improves the modularity of the electrolysis unit 10. The improved modularity makes the electrolysis unit 10 easier to assemble, disassemble, and reassemble, thereby reducing the production and maintenance costs of the electrolysis unit 10. On the other hand, it also makes the electrolysis device easier to assemble, disassemble, and reassemble, thereby reducing the production and maintenance costs of the electrolysis device.

[0029] Using the above configuration and taking an alkaline water electrolyzer as an example, the operation of the electrolysis unit 10 is described. After an electrolyte such as sodium hydroxide solution or potassium hydroxide solution is injected into the first chamber 131a and the second chamber 131b, and power is supplied to the first electrode layer 410 and the second electrode layer 420 via an external DC power supply, the electrolyte entering the first chamber 131a is diffused by the first porous transport layer 510 and distributed onto the first electrode layer 410, while the electrolyte entering the second chamber 131b is diffused by the second porous transport layer 520 and distributed onto the second electrode layer 420. Further, when the first electrode layer 410 acts as the anode electrode layer and is electrically connected to the positive terminal of the external DC power supply, and the second electrode layer 420 acts as the cathode electrode layer and is electrically connected to the negative terminal of the external DC power supply, at the second electrode layer 420, water molecules in the electrolyte decompose into hydrogen molecules and hydroxide ions due to gaining electrons (i.e., a hydrogen evolution reaction occurs, also known as a reduction reaction). 4H 2 O+4e - →2H 2 + 4OH - Hydrogen molecules, unable to pass through the diaphragm 310, diffuse as bubbles into the electrolyte in the second chamber 131b. Hydroxide ions, driven by voltage, pass from the second electrode layer 420 through the diaphragm 310 to the first electrode layer 410. At the first electrode layer 410, the hydroxide ions lose electrons and decompose into oxygen and water molecules (i.e., an oxygen evolution reaction occurs, also known as an oxidation reaction). OH - →2 H 2 O + O 2 +4 e -In this process, oxygen molecules, unable to pass through the diaphragm 310, diffuse as bubbles into the electrolyte in the first chamber 131a. Through the aforementioned electrochemical reaction, water in the electrolyte is electrolyzed into hydrogen and oxygen in the electrolysis unit 10, and the hydrogen and oxygen will exist in the electrolyte as bubbles. Specifically, when the bipolar plate 200 abuts against the first surface 110 of the main electrode frame 100, the first electrode layer 410 can be electrically connected to an external DC power supply through the first porous transport layer 510 and the bipolar plate 200, while the second electrode layer 420 can be electrically connected to an external DC power supply through the second porous transport layer 520 and the bipolar plate 200 of another electrolysis unit 10 adjacent to the electrolysis unit 10 in the electrolysis device. In this configuration, in addition to the two bipolar plates 200 at both ends of the electrolysis unit, each bipolar plate 200 located in the middle of the electrolysis unit serves as both the cathode plate (i.e., the plate electrically connected to the cathode electrode layer) of one electrolysis unit 10 and the anode plate (i.e., the plate electrically connected to the anode electrode layer) of another electrolysis unit 10. Furthermore, it is worth mentioning that since the two annular contact areas formed between the diaphragm 310 and the stepped portion 132 and the secondary electrode frame 320 can effectively isolate the first chamber 131a and the second chamber 131b from each other, the above configuration can reliably prevent the oxygen generated in the first chamber 131a from mixing with the hydrogen generated in the second chamber 131b. This not only improves the purity of the hydrogen and oxygen discharged from the electrolysis unit 10 but also enhances the safety of the electrolysis unit 10.

[0030] In order to transport electrolytes in and out of the first chamber 131a and the second chamber 131b for the aforementioned electrochemical reaction and to discharge oxygen and hydrogen, as follows: Figure 1 and Figure 2As shown, the main electrode frame 100 also has a plurality of outer holes 150 extending through it along the thickness direction TT' (i.e., extending from the first surface 110 to the second surface 120). Each outer hole 150 is positioned in the lateral direction between the inner sidewall 130 and the outer sidewall 140 of the main electrode frame 100, such that each outer hole 150 is spaced apart from the central hole 131 in the lateral direction. In addition, the bipolar plate 200 also has a plurality of mass transfer holes 250 extending through it along the thickness direction TT'. Each mass transfer hole 250 is designed to be aligned with the corresponding outer hole 150 of the main electrode frame 100 along the stacking direction SS'. In other words, after the electrolysis unit 10 is assembled, each outer hole 150 of the main electrode frame 100 can be aligned with the corresponding mass transfer hole 250 of the bipolar plate 200 along the stacking direction SS'. In this configuration, each outer hole 150 of the main electrode frame 100 and the corresponding mass transfer hole 250 of the bipolar plate 200 form a manifold extending through the electrolysis unit 10 along the stacking direction SS', which allows electrolyte to flow through the electrolysis unit 10 along the stacking direction SS'. Of course, after multiple electrolysis units 10 are stacked together to form an electrolysis device, each manifold of each electrolysis unit 10 can be aligned with the corresponding manifold of the adjacent electrolysis unit 10 along the stacking direction SS', thereby forming a manifold extending through the electrolysis device along the stacking direction SS', which allows electrolyte to flow through the electrolysis device along the stacking direction SS'. Specifically, the multiple outer holes 150 of the main electrode frame 100 include two (or more) first outer holes 151 located on opposite sides of the central hole 131 along the lateral direction, and two (or more) second outer holes 152 also located on opposite sides of the central hole 131 along the lateral direction. Additionally, the bipolar plate 200 includes a plurality of mass transfer holes 250, including two first mass transfer holes 251 aligned with two first outer holes 151 along the stacking direction SS' and two second mass transfer holes 252 aligned with two second outer holes 152 along the stacking direction SS'. In this configuration, the two first outer holes 151 of the main electrode frame 100 and the two first mass transfer holes 251 of the bipolar plate 200 form two first manifolds located on both sides of the central hole 131, and the two second outer holes 152 of the main electrode frame 100 and the two second mass transfer holes 252 of the bipolar plate 200 form two second manifolds located on both sides of the central hole 131.

[0031] Furthermore, the main pole frame 100 is also provided with a plurality of distribution grooves 160 recessed along the thickness direction TT' from the first surface 110 or the second surface 120, wherein each distribution groove 160 extends along the lateral direction from one of the plurality of outer holes 150 to the central hole 131. Specifically, as Figure 1As shown, the main electrode frame 100 has a plurality of distribution slots 160 including two first distribution slots 161 recessed from the first surface 110, wherein each first distribution slot 161 extends from one of the two first outer holes 151 to the central hole 131 (i.e., the first chamber 131a). In particular, the secondary electrode frame 320 is provided with two connecting slots 321 recessed from its surface along the thickness direction TT', wherein each connecting slot 321 extends from the outer side to the inner side of the secondary electrode frame 320 in a transverse direction, such that after the electrolysis unit 10 is assembled, each connecting slot 321 can fluidly communicate one of the two first distribution slots 161 with the first chamber 131a surrounded by the secondary electrode frame 320. In this configuration, each first outer port 151 (i.e., each first manifold) can be in fluid communication with the first chamber 131a through a corresponding first distribution groove 161 and connecting groove 321, so that the first chamber 131a can receive electrolyte from one first manifold and discharge electrolyte containing oxygen generated by electrolysis to another first manifold, thereby realizing the delivery of electrolyte in and out of the first chamber 131a. Figure 2 As shown, the plurality of distribution slots 160 of the main electrode frame 100 also include two second distribution slots 162 recessed from the second surface 120, wherein each second distribution slot 162 extends from one of the two second outer holes 152 to the central hole 131 (i.e., the second chamber 131b). In this configuration, each second outer hole 152 (i.e., each second manifold) can be in fluid communication with the second chamber 131b through the corresponding second distribution slot 162, so that the second chamber 131b can receive electrolyte from one second manifold and discharge electrolyte containing hydrogen gas generated by electrolysis to the other second manifold, thereby realizing the delivery of electrolyte in and out of the second chamber 131b. It should be noted that the above-described method of realizing the delivery of electrolyte in and out of the first chamber 131a and the second chamber 131b is merely exemplary. In other embodiments not shown, the first chamber 131a can be in fluid communication with the two first manifolds and the second chamber 131b can be in fluid communication with the two second manifolds in other ways. For example, the first chamber 131a can be fluidly connected to two first manifolds via channels located inside the main pole frame 100 and the secondary pole frame 320, rather than on the surface, and the second chamber 131b can be fluidly connected to two second manifolds via channels located inside the main pole frame 100, rather than on the surface. As another example, each first manifold can be fluidly connected to the first chamber 131a via multiple, rather than a single, first distribution slots 161 and multiple, rather than a single, connecting slots 321, and each second manifold can be fluidly connected to the second chamber 131b via multiple, rather than a single, second distribution slots 162.

[0032] refer to Figure 3 and Figure 4 ,in, Figure 3 It shows Figure 1 and Figure 2 The schematic assembly front view of the electrolysis unit 10 shown is as follows: Figure 4 It shows Figure 1 and Figure 2 The diagram shows a schematic rear view of the electrolysis unit 10 after assembly. It should be noted that... Figure 3 In the diagram, the first chamber 131a, the first distribution groove 161, and the secondary pole frame 320, etc., are shown with dashed lines because they are obscured by the bipolar plate 200. Figure 3 As shown, two first manifolds, each consisting of two first outer holes 151 of the main pole frame 100 and two first mass transfer holes 251 of the bipolar plate 200, are located on opposite sides of the first chamber 131a in the lateral direction. Each first manifold is in fluid communication with the first chamber 131a through a corresponding first distribution groove 161 of the main pole frame 100 and a corresponding communication groove 321 of the secondary pole frame 320. Similarly, as Figure 4 As shown, two second manifolds, consisting of two second outer holes 152 of the main pole frame 100 and two second mass transfer holes 252 of the bipolar plate 200, are located on opposite sides of the second chamber 131b in the lateral direction, and each second manifold is in fluid communication with the second chamber 131b through a corresponding second distribution groove 162 of the main pole frame 100.

[0033] To further improve the safety and reliability of the electrolysis unit 10, the main electrode frame 100 is also provided with multiple sealing grooves and includes multiple sealing rings, wherein each sealing ring is held in one of the multiple sealing grooves, that is, the main electrode frame 100 holds multiple sealing rings through multiple sealing grooves. With the help of these sealing rings, reliable sealing of each electrolysis unit 10 can be achieved without applying a large assembly force to the electrolysis unit 10 or multiple electrolysis units 10 stacked together. Specifically, as... Figure 3As shown, the main electrode frame 100 has a plurality of sealing grooves including a first outer sealing groove 171 recessed from the first surface 110 and two (or more) first inner sealing grooves 172. The first outer sealing groove 171 is arranged to surround the central hole 131, each outer hole 150, and each distribution groove 160 (if any), and each first inner sealing groove 172 is arranged to surround one of the two second through holes 152. In this configuration, with the bipolar plate 200 abutting against the first surface 110, the sealing rings in the first outer sealing groove 171 and each of the first inner sealing grooves 172 are clamped between the main electrode frame 100 and the bipolar plate 200. This allows the sealing rings in the first outer sealing groove 171 to prevent electrolyte in the first chamber 131a, each manifold, and each first distribution groove 161 from leaking to the outside of the electrolysis unit 10 through the gap between the main electrode frame 100 and the bipolar plate 200, thereby protecting the electrolysis device. Other components and the operating environment are protected from electrolyte contamination, thereby further improving the reliability of the electrolysis unit 10. The sealing ring in each first inner sealing groove 172 can prevent the electrolyte in the corresponding second manifold from leaking into the first manifold, the first distribution groove 161 or the first chamber 131a through the gap between the main electrode frame 100 and the bipolar plate 200. This can prevent the oxygen generated in the first chamber 131a from mixing with the hydrogen generated in the second chamber 131b, thereby further improving the safety of the electrolysis unit 10.

[0034] Similarly, such as Figure 4As shown, the main electrode frame 100's plurality of sealing grooves also includes a second outer sealing groove 173 recessed from the second surface 120 and two (or more) second inner sealing grooves 174, wherein the second outer sealing groove 173 is arranged to surround the central hole 131, each outer hole 150, and each distribution groove 160 (if any), and each second inner sealing groove 174 is arranged to surround one of the two first through holes 151. In this configuration, when the bipolar plate 200 of another electrolysis unit 10 abuts against the second surface 120, the sealing rings in the second outer sealing groove 173 and the sealing rings in each of the second inner sealing grooves 174 are clamped between the main electrode frame 100 and the bipolar plate 200. This allows the sealing rings in the second outer sealing groove 173 to prevent electrolyte in the second chamber 131b, each manifold, and each second distribution groove 162 from leaking to the outside of the electrolysis unit 10 through the gap between the main electrode frame 100 and the bipolar plate 200, thereby protecting the electrolyte. Other components of the electrolysis unit and the operating environment are protected from electrolyte contamination, thereby further improving the reliability of the electrolysis unit 10. The sealing ring in each second inner sealing groove 174 can prevent the electrolyte in the corresponding first manifold from leaking into the second manifold, the second distribution groove 162 or the second chamber 131b through the gap between the main electrode frame 100 and the bipolar plate 200. This can prevent the oxygen generated in the first chamber 131a from mixing with the hydrogen generated in the second chamber 131b, thereby further improving the safety of the electrolysis unit 10.

[0035] refer to Figure 5 , which shows along Figure 3 A schematic cross-sectional view of the electrolysis unit 10 taken from line VV in the diagram. (See diagram for reference.) Figure 5 As shown, the main electrode frame 100 also includes a central sealing groove 175 recessed from the stepped portion 132 of the inner sidewall 130 and arranged around the entire circumference. In this configuration, the central sealing groove 175 can form a complete annular shape around the second chamber 131b, and when the diaphragm 310 abuts against the stepped portion 132, the sealing ring in the central sealing groove 175 is clamped between the diaphragm 310 and the stepped portion 132. This allows the sealing ring to reliably seal the annular contact area formed between the diaphragm 310 and the stepped portion 132, effectively preventing oxygen generated in the first chamber 131a and hydrogen generated in the second chamber 131b from mixing through the gap between the diaphragm 310 and the stepped portion 132, thereby further improving the safety of the electrolysis unit 10. Specifically, the secondary electrode frame 320 can be made of a hard material such as resin or metal, and as... Figure 5As shown, the sub-electrode frame 320 may be provided with an auxiliary sealing groove 322 recessed from its surface intended to abut against the diaphragm 310 and arranged circumferentially, and includes an auxiliary sealing ring held in the auxiliary sealing groove 322. In this configuration, with the sub-electrode frame 320 abutting against the diaphragm 310 and the diaphragm 310 abutting against the stepped portion 132, the auxiliary sealing groove 322 can form a complete annular shape around the first chamber 131a, and the auxiliary sealing ring in the auxiliary sealing groove 322 will be clamped between the sub-electrode frame 320 and the diaphragm 310. This allows the auxiliary sealing ring to reliably seal the annular contact area formed between the diaphragm 310 and the sub-electrode frame 320, thereby effectively preventing the oxygen generated in the first chamber 131a and the hydrogen generated in the second chamber 131b from mixing through the gap between the diaphragm 310 and the sub-electrode frame 320, thereby further improving the safety of the electrolysis unit 10. It should be noted that the method of sealing the two annular contact areas between the diaphragm 310 and the secondary pole frame 320 and the stepped portion 132 described above is merely exemplary. In other embodiments not shown, other methods can also be used to seal these two annular contact areas. For example, the secondary pole frame 320 can be made of a rubber material such as EPDM or other elastic materials, thereby enabling the secondary pole frame 320 itself to seal the annular contact area between itself and the diaphragm 310 without the need for additional sealing grooves or additional sealing rings in the secondary pole frame 320.

[0036] Next, with the help of Figure 5 The enlarged view in the diagram illustrates a specific configuration of at least one of the plurality of sealing grooves in the main pole frame 100, using the second outer sealing groove 173 as an example. It should be noted that the following description of the second outer sealing groove 173 also applies to the other sealing grooves of the main pole frame 100. For example... Figure 5As shown in the enlarged view indicated by the solid line, the sealing ring in the second outer sealing groove 173 protrudes from the second outer sealing groove 173 in its natural state. That is, the natural height of the sealing ring (i.e., the height of the sealing ring when it is not compressed) is greater than the depth of the second outer sealing groove 173 (i.e., the dimension measured along the thickness direction TT'). This allows the sealing ring to be pressed between the main pole frame 100 and the bipolar plate 200, resulting in an elastic restoring force. This elastic restoring force allows the sealing ring to abut against both the main pole frame 100 and the bipolar plate 200, thereby forming a reliable seal between the main pole frame 100 and the bipolar plate 200. Specifically, the difference between the natural height of the sealing ring and the depth of the second outer sealing groove 173 is greater than 25% of its natural height. This allows the bipolar plate 200 to compress the height of the sealing ring by at least 25% after abutting against the main pole frame 100. This at least 25% compression provides sufficient elastic restoring force to the sealing ring, ensuring a tighter fit between the sealing ring and both the main pole frame 100 and the bipolar plate 200, thus forming a more reliable seal between them. Specifically, the cross-sectional area of ​​the sealing ring is less than 90% of the cross-sectional area of ​​the second outer sealing groove 173. This allows the bipolar plate 200 to completely compress the sealing ring into the second outer sealing groove 173, ensuring that the bipolar plate 200 abuts against the first surface 110 or the second surface 120 of the main pole frame 100, without being separated from the first surface 110 or the second surface 120 due to any portion of the sealing ring that cannot be compressed into the second outer sealing groove 173. Specifically, as... Figure 5 As shown in the enlarged view indicated by the dashed line, one or both of the two opposing sidewalls of the second outer sealing groove 173 along the lateral direction are configured to be inclined relative to the thickness direction TT', so that the second outer sealing groove 173 widens as it approaches its bottom. In this configuration, after the bipolar plate 200 compresses the sealing ring into the second outer sealing groove 173, the inclined sidewalls of the second outer sealing groove 173 in the manner described above help to lock the sealing ring in the second outer sealing groove 173, thereby preventing the sealing ring from accidentally dislodging from the second outer sealing groove 173, thus enabling the sealing ring to form a more reliable seal between the main electrode frame 100 and the bipolar plate 200.

[0037] Continue to refer to Figure 5The second chamber 131b has an internal opening 135 located at the stepped portion 132 for being covered by the diaphragm 310 and an external opening 136 located at the second surface 120 for being covered by the bipolar plate 200 (e.g., the bipolar plate 200 of another electrolysis unit 10 in the electrolysis apparatus). In other words, the second chamber 131b extends along the thickness direction TT' from the internal opening 135 at the stepped portion 132 to the external opening 136 at the second surface 120. The second electrode layer 420 can abut against the diaphragm 310 by means of the internal opening 135, and the second porous transport layer 520 can abut against the bipolar plate 200 by means of the external opening 136. Additionally, the main pole frame 100 also includes a retaining structure 137 disposed on the inner sidewall 130 and positioned in the thickness direction TT' between the stepped portion 132 and the second surface 120. This retaining structure 137 is configured to reduce the lateral dimension of the second chamber 131b such that the size of the external opening 136 of the second chamber 131b is smaller than the size of the internal opening 135, and the retaining structure 137 is also configured to abut against the second porous transport layer 520. Specifically, the retaining structure 137 is flush with the second surface 120 on the side facing away from the diaphragm 310 along the thickness direction TT'. More specifically, the retaining structure 137 may be formed by a flange projecting inward from the inner sidewall 130. Of course, the above embodiments are merely exemplary, and in other embodiments not shown, the retaining structure 137 may be formed in other ways. For example, the retaining structure 137 may be formed by an inclined portion of the inner sidewall 130, which is configured to reduce the lateral dimension of the second chamber 131b as it approaches the second surface 120 in the thickness direction TT'. In this configuration, because the retaining structure 137 causes the size of the external opening 136 of the second chamber 131b to be smaller than the size of its internal opening 135 and to abut against the second porous transport layer 520, the retaining structure 137 can prevent the second porous transport layer 520 and the second electrode layer 420 from leaving the second chamber 131b through the external opening 136. This ensures that the components housed in the central hole 131 can only enter and exit the central hole 131 through the opening on the first surface 110, and will not accidentally leave the central hole 131 through the external opening 136. In particular, when the bipolar plate 200 abuts against the first surface 110, the bipolar plate 200 can cover the opening of the central hole 131 on the first surface 110, thereby reliably retaining the components in the central hole 131, thereby further improving the reliability and modularity of the electrolysis unit 10.

[0038] refer to Figure 6 , which shows along Figure 3 A schematic cross-sectional view of the electrolysis unit 10 taken from line VI-VI in the diagram. (See attached image.) Figures 3-6As shown, the main pole frame 100 also includes a plurality of (six shown in the figure) positioning protrusions 180 protruding from the first surface 110 along the thickness direction TT' and a plurality of (six shown in the figure) positioning grooves 190 recessed from the second surface 120 along the thickness direction TT', wherein each positioning groove 190 is aligned with one of the plurality of positioning protrusions 180 along the thickness direction TT' and is configured in shape to allow the positioning protrusion 180 to be inserted. Additionally, refer to... Figure 7 , which shows Figures 1-6 The schematic formal view of the bipolar plate 200 of the electrolysis unit 10 shown illustrates that, in addition to the mass transfer holes 250, the bipolar plate 200 also has a plurality of (six shown in the figure) positioning holes 280 extending through along the thickness direction TT', wherein, as... Figure 5 and Figure 6 As shown, each positioning hole 280 is configured to allow one of the plurality of positioning protrusions 180 to pass through. In this configuration, the plurality of positioning protrusions 180 of the main electrode frame 100 can pass through the plurality of positioning holes 280 of the bipolar plate 200, thereby reliably holding the bipolar plate 200 on the first surface 110 of the main electrode frame 100. This allows the bipolar plate 200 to reliably prevent the components in the central hole 131 from accidentally dislodging from the central hole 131 through the opening in the central hole 131 on the first surface 110. Therefore, the above configuration can further improve the modularity of the electrolysis unit 10, especially when the bipolar plate 200 cooperates with the aforementioned holding structure 137. The components in the central hole 131 cannot be accidentally dislodged from the central hole 131 in any way. This allows the electrolysis unit 10 to be constructed as an almost completely independent modular unit, thereby further improving the modularity of the electrolysis unit 10. It is also worth mentioning that when multiple electrolysis units 10 are stacked together to assemble an electrolysis device, multiple positioning protrusions 180 of the main electrode frame 100 of one electrolysis unit 10 can be inserted into multiple positioning slots 190 of the main electrode frame 100 of another electrolysis unit 10 after passing through multiple positioning holes 280 of the bipolar plate 200. This allows the individual electrolysis units 10 to be accurately and reliably positioned together, for example, so that the corresponding manifolds of the individual electrolysis units 10 can be accurately aligned with each other to form a manifold extending through the electrolysis device. Therefore, the above configuration can also improve the reliability and assembly accuracy of the electrolysis device. Furthermore, it should be noted that the above embodiments are merely exemplary; in other embodiments not shown, the positioning protrusions 180 and positioning slots 190 can also be formed in other ways. For example, the main pole frame 100 may include a plurality of positioning protrusions 180 protruding from the second surface 120 along the thickness direction TT' and have a plurality of positioning grooves 190 recessed from the first surface 110 along the thickness direction TT'. In this case, the bipolar plate 200 will be held on the second surface 120 of the main pole frame 100 by the plurality of positioning protrusions 180.

[0039] In particular, such as Figures 3-7 As shown, at least one of the plurality of positioning protrusions 180 of the main pole frame 100 is configured as a locking protrusion having a neck 181 and an end 182 that expands laterally relative to the neck 181. The end 182 is connected to the first surface 110 via the neck 181 such that the end 182 is spaced apart from the first surface 110 along the thickness direction TT'. Of course, when the locking protrusion is provided on the second surface 120, the end 182 is connected to the second surface 120 via the neck 181 such that the end 182 is spaced apart from the second surface 120 along the thickness direction TT'. Specifically, as... Figure 6 As shown, since the end 182 of the locking protrusion expands laterally relative to the neck 181, the locking protrusion can be configured in a T-shape. Additionally, as... Figure 7 As shown, at least one of the plurality of positioning holes 280 of the bipolar plate 200 is configured as a locking hole through which a locking protrusion passes. The locking hole has a narrow portion 281 and a wide portion 282 that expands laterally relative to the narrow portion 281. The narrow portion 281 is configured to allow the neck 181 of the locking protrusion to pass through while preventing the end 182 from passing through. In other words, the narrow portion 281 is configured to allow only the neck 181 of the locking protrusion to pass through, and the wide portion 282 is configured to allow both the neck 181 and the end 182 of the locking protrusion to pass through. For example, the lateral dimension of the narrow portion 281 can be set to be larger than the lateral dimension of the neck 181 but smaller than the lateral dimension of the end 182, so that the neck 181 can pass through the narrow portion 281 but the end 182 cannot. Similarly, the lateral dimension of the wide portion 282 can be set to be larger than the lateral dimension of the end 182, so that both the neck 181 and the end 182 can pass through the wide portion 282. Specifically, as... Figure 7 As shown, since the width 282 of the locking hole is expanded in the lateral direction relative to the narrow portion 281, the locking hole can be configured in a T-shape. In particular, each positioning protrusion 180 of the main pole frame 100 is configured as a locking protrusion, and each positioning hole 280 of the bipolar plate 200 is configured as a locking hole.

[0040] In the above case, when assembling the main pole frame 100 and the bipolar plate 200 together, the end 182 of the locking protrusion of the main pole frame 100 can be aligned with the width 282 of the locking hole of the bipolar plate 200 along the thickness direction TT'. Then, the bipolar plate 200 is pushed toward the main pole frame 100 until the neck 181 and end 182 of the locking protrusion pass through the width 282 of the locking hole. Finally, the bipolar plate 200 is moved in the lateral direction until the neck 181 of the locking protrusion enters the narrow part 281 of the locking hole. In this configuration, since the end 182 of the locking protrusion cannot pass through the narrow portion 281 of the locking hole, the end 182 of the locking protrusion can lock the bipolar plate 200 onto the main electrode frame 100, thereby preventing the bipolar plate 200 from accidentally detaching from the main electrode frame 100. When combined with the retaining structure 137 mentioned above, the above configuration constructs the electrolysis unit 10 as an independent modular unit, thereby enabling the electrolysis unit 10 to be placed and transported in any way as an independent module. This not only improves the reliability of the electrolysis unit 10 and reduces its production and maintenance costs, but also reduces the production and maintenance costs of the electrolysis device.

[0041] refer to Figure 8 The diagram shows multiple stacked together. Figures 1-6 A schematic cross-sectional view of the electrolysis apparatus 20 of the electrolysis unit 10 shown. Figure 8 As shown, the electrolysis apparatus 20 includes a plurality of electrolysis units 10 (three shown in the figure) stacked together along the stacking direction SS'. The bipolar plate 200 of each electrolysis unit 10 is held on the first surface 110 of the main electrode frame 100 of the electrolysis unit 10 and abuts against the second surface 120 of the main electrode frame 100 of the adjacent electrolysis unit 10 on the other side, such that the bipolar plate 200 is electrically connected to the first electrode layer 410 of the electrolysis unit 10 through the first porous transport layer 510 and to the second electrode layer 420 of the adjacent electrolysis unit 10 through the second porous transport layer 520. In this way, the individual electrolysis units 10 are connected in series. Furthermore, multiple positioning protrusions 180 of the main electrode frame 100 of each electrolysis unit 10 are inserted into multiple positioning slots 190 of the main electrode frame 100 of the adjacent electrolysis unit 10 after passing through multiple positioning holes 280 of its bipolar plate 200. In this way, the individual electrolysis units 10 are reliably and precisely assembled together, and the corresponding manifolds of the individual electrolysis units 10 are aligned with each other along the stacking direction SS', thereby forming a manifold extending through the electrolysis device 20. It is also worth noting that, since the high level of modularity of the electrolysis units 10 allows the individual electrolysis units 10 to be arranged and stacked together in a horizontal direction, the above configuration can significantly reduce the assembly difficulty of the electrolysis device 20, thereby improving the reliability of the electrolysis device 20 and reducing its production and maintenance costs.

[0042] The optional but non-limiting embodiments of the electrolysis unit and electrolysis apparatus according to this disclosure have been described in detail above with reference to the accompanying drawings. Modifications and additions to the technology and structure, as well as recombinations of features in the various embodiments, should be considered within the scope of this disclosure without departing from its spirit and essence. Therefore, such modifications and additions conceivable under the teachings of this disclosure should be considered part of this disclosure. The scope of this disclosure includes equivalent technologies known at the filing date of this disclosure and equivalent technologies not yet foreseen.

Claims

1. An electrolysis unit, characterized in that, include: A main pole frame (100) having a first surface (110) and a second surface (120) opposite in the thickness direction, and an inner sidewall (130) and an outer sidewall (140) spaced apart in the transverse direction, the inner sidewall (130) defining a central hole (131) extending through the main pole frame (100) in the thickness direction and having a stepped portion (132) opposite in the thickness direction to the second surface (120). Bipolar plate (200) abutting against the first surface (110) or the second surface (120). A diaphragm (310) and a sub-pole frame (320) are housed in the central hole (131). The sub-pole frame (320) is annular and pushes the diaphragm (310) against the stepped portion (132) so that the central hole (131) is divided by the diaphragm (310) into a first chamber (131a) leading to the first surface (110) and a second chamber (131b) leading to the second surface (120). A first porous transport layer (510) housed in the first chamber (131a) and a first electrode layer (410) located between the diaphragm (310) and the first porous transport layer (510); and The second porous transport layer (520) is housed in the second chamber (131b) and the second electrode layer (420) is located between the diaphragm (310) and the second porous transport layer (520).

2. The electrolysis unit according to claim 1, characterized in that, The main pole frame (100) is also provided with a plurality of sealing grooves and includes a plurality of sealing rings, wherein each sealing ring is held by a corresponding sealing groove, and the natural height of each sealing ring is greater than the depth of the corresponding sealing groove.

3. The electrolysis unit according to claim 2, characterized in that, The main pole frame (100) is also provided with a plurality of outer holes (150) extending through the thickness direction. The plurality of sealing grooves include a first outer sealing groove (171) recessed from the first surface (110) and a second outer sealing groove (173) recessed from the second surface (120). Each of the first outer sealing groove (171) and the second outer sealing groove (173) is arranged to surround the central hole (131) and the plurality of outer holes (150).

4. The electrolysis unit according to claim 3, characterized in that, The plurality of outer holes (150) include a plurality of first outer holes (151) communicating with the first chamber (131a) and a plurality of second outer holes (152) communicating with the second chamber (131b). The plurality of sealing grooves also include a plurality of first inner sealing grooves (172) recessed from the first surface (110) and a plurality of second inner sealing grooves (174) recessed from the second surface (120), wherein each first inner sealing groove (172) is arranged to surround one of the plurality of second outer holes (152) and each second inner sealing groove (174) is arranged to surround one of the plurality of first outer holes (151).

5. The electrolysis unit according to claim 4, characterized in that, The main pole frame (100) is further provided with a plurality of first distribution grooves (161) recessed from the first surface (110), and the secondary pole frame (320) is provided with a plurality of connecting grooves (321). Each first outer hole (151) is connected to the first chamber (131a) through a corresponding first distribution groove (161) and connecting groove (321), and the first outer sealing groove (171) is also arranged to surround the plurality of first distribution grooves (161).

6. The electrolysis unit according to claim 4, characterized in that, The main pole frame (100) is further provided with a plurality of second distribution grooves (162) recessed from the second surface (120), wherein each second outer hole (152) communicates with the second chamber (131b) through the corresponding second distribution groove (162), and the second outer sealing groove (173) is also arranged to surround the plurality of second distribution grooves (162).

7. The electrolysis unit according to claim 2, characterized in that, The plurality of sealing grooves also include a central sealing groove (175) recessed from the stepped portion (132), the central sealing groove (175) being arranged to surround the second chamber (131b).

8. The electrolysis unit according to any one of claims 2-7, characterized in that, The difference between the natural height of at least one of the plurality of sealing rings and the depth of the corresponding sealing groove is greater than 25% of the natural height of the sealing ring; and / or, the cross-sectional area of ​​at least one of the plurality of sealing rings is less than 90% of the cross-sectional area of ​​the corresponding sealing groove; and / or, at least one of the plurality of sealing grooves has a sidewall inclined relative to the thickness direction, such that the sealing groove widens as it approaches its bottom.

9. The electrolysis unit according to any one of claims 1-7, characterized in that, The second chamber (131b) extends along the thickness direction from an internal opening (135) located at the stepped portion (132) to an external opening (136) located at the second surface (120). The main pole frame (100) also includes a retaining structure (137) disposed on the inner sidewall (130), the retaining structure (137) being configured to reduce the lateral dimension of the second chamber (131b) and abut against the second porous transmission layer (520).

10. The electrolysis unit according to claim 9, characterized in that, The bipolar plate (200) abuts against the first surface (110) and covers the central hole (131) such that the diaphragm (310) and the sub-electrode frame (320) are sandwiched between the bipolar plate (200) and the stepped portion (132).

11. The electrolysis unit according to claim 9, characterized in that, The retaining structure (137) is formed by a flange protruding from the inner sidewall (130) in the lateral direction; or, the retaining structure (137) is formed by an inclined portion of the inner sidewall (130) configured to reduce the lateral dimension of the second chamber (131b) as it approaches the second surface (120).

12. The electrolysis unit according to any one of claims 1-7, characterized in that, The main pole frame (100) further includes a plurality of positioning protrusions (180) protruding from the first surface (110) and a plurality of positioning grooves (190) recessed from the second surface (120), wherein each positioning groove (190) is aligned with the corresponding positioning protrusion (180) along the thickness direction and is shaped to allow the positioning protrusion (180) to be inserted, and the bipolar plate (200) is provided with a plurality of positioning holes (280), wherein each positioning hole (280) allows the corresponding positioning protrusion (180) to pass through.

13. The electrolysis unit according to claim 12, characterized in that, At least one of the plurality of positioning protrusions (180) is configured as a locking protrusion having a neck (181) and an end (182) that expands laterally relative to the neck (181), the end (182) being connected to the first surface (110) via the neck (181), and at least one of the plurality of positioning holes (280) is configured as a locking hole having a narrow portion (281) that allows only the neck (181) to pass through and a wide portion (282) that allows both the neck (181) and the end (182) to pass through.

14. The electrolysis unit according to any one of claims 1-7, characterized in that, The sub-pole frame (320) is provided with an auxiliary sealing groove (322) that holds an auxiliary sealing ring and is arranged to surround the first chamber (131a), and the auxiliary sealing ring is configured to be sandwiched between the diaphragm (310) and the sub-pole frame (320); and / or, the sub-pole frame (320) is made of an elastic material.

15. An electrolysis apparatus, characterized in that, It includes multiple electrolysis units stacked together along the thickness direction according to any one of claims 1-14.

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