CN113215603A

CN113215603A - Water electrolysis pile

Info

Publication number: CN113215603A
Application number: CN202110342988.XA
Authority: CN
Inventors: 江亚阳; 杨福源; 党健; 李洋洋; 古俊杰; 杨明烨
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2021-03-30
Filing date: 2021-03-30
Publication date: 2021-08-06
Anticipated expiration: 2041-03-30
Also published as: CN113215603B

Abstract

The invention relates to a water electrolysis stack comprising: the electrolytic cell comprises a membrane electrode assembly, an anode assembly and a cathode assembly, wherein the anode assembly and the cathode assembly are respectively positioned on two sides of the membrane electrode assembly, the anode assembly of the electrolytic cell is adjacent to the anode assembly of the electrolytic cell, and/or the cathode assembly of the electrolytic cell is adjacent to the cathode assembly of the electrolytic cell. The thickness of the water electrolysis pile can be reduced as much as possible, so that the manufacturing cost is reduced.

Description

Water electrolysis pile

Technical Field

The invention relates to the technical field of water electrolysis, in particular to a water electrolysis pile.

Background

As a novel energy source, the hydrogen energy source is not easy to cause environmental pollution and is high-efficiency, so that the hydrogen energy source receives more and more extensive attention. In the related art, hydrogen is mainly obtained by electrolyzing water through a proton exchange membrane. Many current water electrolysis galvanic piles select to directly output high-pressure hydrogen in order to be able to omit a compressor for compressing the hydrogen. However, in order to prevent the adjacent electrolytic cells from being broken due to excessive pressure difference in the high-pressure output hydrogen environment, the thickness of the parts is increased to resist the pressure difference, which results in more material consumption and higher cost.

Disclosure of Invention

The invention provides a water electrolysis pile, which can reduce the thickness of the pile as much as possible, thereby reducing the manufacturing cost.

A water electrolysis stack comprising:

the electrolytic cell comprises a membrane electrode assembly, an anode assembly and a cathode assembly, wherein the anode assembly and the cathode assembly are respectively positioned on two sides of the membrane electrode assembly, the anode assembly of the electrolytic cell is adjacent to the anode assembly of the electrolytic cell, and/or the cathode assembly of the electrolytic cell is adjacent to the cathode assembly of the electrolytic cell.

In one embodiment, the cathode assembly is provided with a first segment of the hydrogen outlet extending in the axial direction at a central position of the cathode assembly.

In one embodiment, the cathode assembly comprises a cathode plate, a hydrogen outlet second section extending along the radial direction is arranged on the outer surface of the cathode plate, the hydrogen outlet second section is communicated with the hydrogen outlet first section, a hydrogen outlet third section is arranged on the outer side of the electrolytic cell, the hydrogen outlet third section axially penetrates through the electrolytic cell, and the hydrogen outlet third section is communicated with the outer end of the hydrogen outlet second section.

In one embodiment, the outer surface of the cathode plate is provided with a plurality of hydrogen outlet second sections extending along the radial direction, the electrolytic cell is provided with a plurality of groups of hydrogen outlet third sections evenly distributed along the circumferential direction, and each group of hydrogen outlet third sections is respectively communicated with the outer end of each group of hydrogen outlet second sections.

In one embodiment, the cathode assembly further comprises a cathode flow field plate, the hydrogen outlet first section comprises a first through hole located in the center of the cathode flow field plate, the cathode flow field plate is further provided with a plurality of annular flow channels and linear flow channels, the linear flow channels extend in the radial direction and are communicated with the annular flow channels, and the end parts of at least part of the linear flow channels are communicated with the first through hole.

In one embodiment, the cathode assembly includes a cathode plate and a cathode flow field plate with an elastic conductive element disposed therebetween.

In one embodiment, the cathode plate is provided with a projection projecting toward the cathode flow field plate, and the elastic conductive element is sleeved on the projection.

In one embodiment, the anode assembly includes an anode diffusion layer, an anode plate and an anode flow field plate, the water electrolysis stack is provided with a water inlet and an oxygen outlet, the anode plate is provided with a protrusion portion protruding inward in the radial direction, the membrane electrode assembly and the anode flow field plate are separated by the anode diffusion layer and the anode plate, and the water inlet and the oxygen outlet are both located in the region of the protrusion portion.

In one embodiment, the anode flow field plate includes a main body portion and a support portion, the main body portion is located on one side of the protruding portion and the anode diffusion layer, the main body portion is provided with a plurality of hollow grooves, the water inlet and the oxygen outlet are located on the support portion, and the water inlet and the oxygen outlet are both communicated with the hollow grooves.

In one embodiment, the membrane electrode assembly includes a first proton exchange membrane, a second proton exchange membrane, and an interlayer between the first proton exchange membrane and the second proton exchange membrane for reacting hydrogen gas permeating from a cathode side to an anode side to generate hydrogen ions.

In one embodiment, the edge of the membrane electrode assembly is wrapped by a frame film, and the hardness of the frame film is greater than that of the membrane electrode assembly.

The water electrolysis galvanic pile is characterized in that components with the same polarity in adjacent electrolytic cells are adjacently arranged, for example, anode components and/or cathode components of two adjacent electrolytic cells are adjacently arranged. If when outputting high-pressure hydrogen, the cathode side is the high-pressure side, and the anode side is the low-pressure side, after setting up according to above-mentioned mode, the high-pressure side is adjacent with the high-pressure side, and the low pressure side is adjacent with the low-pressure side, and the pressure between the adjacent subassembly is comparatively close, and the pressure differential is less, and the part of electrolysis trough is difficult to damage because of the pressure differential is too big, makes the electrolysis trough have sufficient intensity and guarantees the security when using. And because the arrangement mode reduces the pressure difference between the adjacent electrolytic cells, parts do not need to resist the pressure difference by increasing the thickness, so that the thickness of the electric pile can be reduced, the volume power density is improved, and the manufacturing cost is reduced.

Drawings

FIG. 1 is a schematic diagram of a water electrolysis stack according to an embodiment of the present invention;

FIG. 2 is a side view of the water electrolysis cell stack of FIG. 1;

FIG. 3 is a sectional view of the water electrolysis cell stack of FIG. 1 (with parts in the cathode receiving tank and the anode receiving tank omitted);

FIG. 4 is a cross-sectional view of the water electrolysis cell stack of FIG. 1 taken in another direction (with parts in the cathode receiving tank and the anode receiving tank omitted);

FIG. 5 is a cross-sectional view of one cell of the water electrolysis cell stack of FIG. 1;

FIG. 6 is an enlarged view of a portion of FIG. 5 at A;

FIG. 7 is an exploded view of the cathode assembly of one cell of the water electrolyser stack of FIG. 1 (the third section of the hydrogen outlet, the water inlet and the oxygen outlet, etc. are not shown);

FIG. 8 is an exploded view of the anode assembly of an electrolytic cell in the water electrolyser stack of FIG. 1 (the third section of the hydrogen outlet, the water inlet and the oxygen outlet, etc. are not shown);

FIG. 9 is a schematic view of the anode plate of FIG. 8 in another angle (the third section of the hydrogen outlet, the water inlet, the oxygen outlet, and other holes are not shown);

FIG. 10 is a schematic view of the membrane electrode assembly of the cell of FIG. 5;

FIG. 11 is a schematic structural view of a membrane electrode assembly and a frame membrane of the electrolytic cell of FIG. 5;

FIG. 12 is a schematic view of a seal ring according to an embodiment of the present invention;

FIG. 13 is a partial cross-sectional view of the seal ring of FIG. 12;

FIG. 14 is a top view of a bezel film in an embodiment of the invention.

Reference numerals:

an electrolytic cell 10;

a membrane electrode assembly 100, a first proton exchange membrane 110, a second proton exchange membrane 120, an interlayer 130, a first catalyst layer 140, a second catalyst layer 150;

a cathode assembly 200, a cathode diffusion layer 210, a cathode flow field plate 220, a first through hole 221, an annular flow channel 222, a linear flow channel 223, an elastic conductive element 230, a mounting hole 231, a cathode plate 240, a cathode receiving groove 241, a first sealing groove 242, a projection 243, a discharge groove 244, a second through hole 245, a hydrogen outlet second section 246, a second lug 247, a cathode electrode 250, a hydrogen outlet third section 260, and a hydrogen outlet first section 270;

the anode assembly 300, the anode diffusion layer 310, the anode flow field plate 320, the main body 321, the hollow groove 3211, the first boss 3212, the support 322, the first connecting groove 3221, the second connecting groove 3222, the second boss 3223, the fifth through hole 3224, the sixth through hole 3225, the anode plate 330, the protrusion 331, the anode receiving groove 332, the seventh through hole 333, the groove 334, the second sealing groove 335, the third sealing groove 336, the third lug 337, the anode electrode 340, the water inlet 360, and the oxygen outlet 370;

a frame film 400, a first lug 410;

seal ring 500, projection 510, first surface 520, and second surface 530.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Referring to fig. 1 and 2, a water electrolysis stack according to an embodiment of the present invention includes a plurality of electrolytic cells 10, and the plurality of electrolytic cells 10 are stacked to form the water electrolysis stack. Each of the electrolytic cells 10 includes a cathode assembly 200, an anode assembly 300, and a membrane electrode assembly 100, the cathode assembly 200, the anode assembly 300 being disposed on both sides of the membrane electrode assembly 100, respectively. Referring to fig. 2 to 4, water can be electrolyzed by the water electrolysis cell to generate hydrogen and oxygen. Specifically, water enters each electrolytic cell 10 of the water electrolysis stack from the water inlet 360, oxygen gas and hydrogen ions are generated at the anode of each electrolytic cell 10, the oxygen gas is discharged from the oxygen gas outlet 370, the hydrogen ions pass through the membrane electrode assembly 100 to the cathode side, and hydrogen gas is generated at the cathode and discharged from the hydrogen gas outlet. When the water electrolysis pile is used, the pressure of hydrogen output can be changed by changing a pressure regulating valve or a flow valve connected with a hydrogen outlet. If the hydrogen output pressure is increased, the hydrogen pressure on the cathode side is also increased.

Referring to fig. 1 and 2, adjacent cells are arranged with the same polarity, for example, adjacent anode assemblies 300 of two adjacent cells 10 and adjacent cathode assemblies 200 of two adjacent cells 10. If high-pressure hydrogen is output, the cathode side is a high-pressure side, the anode side is a low-pressure side, and after the arrangement in the above manner, the high-pressure side and the high-pressure side of the adjacent electrolytic cell 10 are adjacent, the low-pressure side and the low-pressure side are adjacent, the pressure between the adjacent cathode assemblies 200 is relatively close, and the pressure between the adjacent anode assemblies 300 is relatively close, so that the pressure difference between the adjacent assemblies is relatively small. Compared with the arrangement of cathode assembly-anode assembly-cathode assembly-anode assembly, the arrangement of cathode assembly-anode assembly-cathode assembly in this embodiment can make the components of the electrolytic cell 10 not easy to be damaged due to excessive pressure difference, so that the electrolytic cell 10 has sufficient strength to ensure the safety in use. Because the pressure difference between the adjacent electrolytic cells 10 is reduced, the pressure difference can be resisted without over designing the thickness of each component, so that the whole thickness of the electric pile can be reduced, the manufacturing cost is reduced, and the power density is improved.

It should be noted that the above-mentioned "adjacent arrangement" in the arrangement of the components of the same polarity in the adjacent electrolytic cells 10, for example, the adjacent arrangement of the anode components 300 of the two adjacent electrolytic cells 10 "does not mean direct contact, but merely for explaining the arrangement sequence of the components, actually, the cathode electrode 250 is disposed between the two cathode components 200 of the two adjacent electrolytic cells 10, and the anode electrode 340 is disposed between the two anode components 300 of the two adjacent electrolytic cells 10. The cathode 250 and the anode 340 are made of copper, and cable connecting parts extending outwards are arranged at corresponding positions on the cathode and the anode for connecting with an external power supply. The corresponding positions of the cathode plate 240 and the cathode electrode 250 are provided with positioning holes, and positioning is realized by the positioning pins penetrating through the positioning holes. The anode plate 330 and the anode electrode 340 are provided with positioning holes at corresponding positions, and positioning is realized by the positioning pins penetrating through the positioning holes.

In the cathode side high pressure state, in addition to ensuring that the adjacent components between the adjacent electrolytic cells 10 can adapt to the high pressure, the internal structure of each electrolytic cell 10 needs to be modified to adapt to the cathode side high pressure state.

When the electric pile outputs high-pressure hydrogen, the cathode side is in a high-pressure state, the pressure is far greater than that of the anode side, each electrolytic cell 10 operates under differential pressure, the hydrogen generated at the cathode can permeate towards the anode side under the action of the differential pressure, the mixed concentration of the hydrogen and the oxygen at the anode side is high, and great risk exists. Referring to fig. 10, in some embodiments, the membrane electrode assembly 100 includes a first proton exchange membrane 110, a second proton exchange membrane 120, and a sandwich 130. The interlayer 130 is located between the first proton exchange membrane 110 and the second proton exchange membrane 120. When the hydrogen gas on the cathode side reaches the anode through the interlayer 130, the electrochemical reaction can be performed under the catalysis of the interlayer 130, hydrogen ions are regenerated, and then the hydrogen gas passes through the membrane electrode assembly 100 from the anode side to the cathode again, and the hydrogen gas is regenerated on the cathode to be discharged. In the above embodiment, the interlayer 130 is provided for catalysis, so that the hydrogen concentration on the anode side can be reduced, the risk of mixing hydrogen and oxygen can be reduced, and the safety of the galvanic pile during use can be improved.

Specifically, in some embodiments, the material of the interlayer 130 is platinum. The hydrogen gas is catalyzed by the platinum interlayer to form hydrogen ions. Alternatively, the material of the interlayer 130 may be other noble metals such as iridium.

Alternatively, in some embodiments, the permeation of hydrogen gas to the anode side may also be reduced by increasing the thickness of the membrane electrode assembly 100. Alternatively, in some embodiments, hydrogen permeation to the anode side may also be reduced by selecting a membrane electrode assembly 100 with a reduced permeability. Alternatively, the above two modes may be combined.

In some embodiments, the first proton exchange membrane 110 and the second proton exchange membrane 120 are perfluorosulfonic acid membranes or other modified membranes with a reinforcing layer to ensure sufficient strength and not easy to deform and crack due to differential pressure. Specifically, the material of the first proton exchange membrane 110 is N115, and the material of the second proton exchange membrane 120 is XL 100. Generally, the larger the thickness of the proton exchange membrane is, the higher the strength is, the larger the thickness of the N115 is, the smaller the thickness of XL100 is, and the combination of the N115 and the XL100 can give consideration to both the thickness and the strength of the membrane, so that the thickness of the proton exchange membrane is reduced as much as possible on the premise of ensuring the strength. In one specific embodiment, N115 is 127 μm thick and XL100 is 27.5 μm thick. Of course, if both the first proton exchange membrane 110 and the second proton exchange membrane 120 are N115, the same can be used.

Further, the membrane electrode assembly 100 further includes a catalyst coated on an outer surface of the membrane material. Specifically, a first catalyst layer 140 on the cathode side and a second catalyst layer 150 on the anode side are included. The material of the first catalyst layer 140 may be platinum black (Pt) or platinum on carbon (Pt/C). The material of the second catalyst layer 150 may be iridium (Ir) or iridium oxide (IrO) oxide thereof₂) A mixture of (a). In a specific embodiment, the first catalyst layer 140 has a thickness of 10 μm and the second catalyst layer 150 has a thickness of 20 μm.

Referring to fig. 11, in order to enhance the sealing performance, sealing rings are disposed between the membrane electrode assembly 100 and the anode assembly 300, and between the membrane electrode assembly 100 and the cathode assembly 200. Preferably, in some embodiments, the edge of the membrane electrode assembly 100 is wrapped by a frame film 400, and the frame film 400 has a hardness greater than that of the membrane electrode assembly 100. By providing the frame film 400, the mea 100 may be prevented from being pressed into the sealing groove provided at the cathode assembly 200 and/or the anode assembly 300 due to an excessive pressure difference, resulting in deformation loss or seal failure of the mea 100. Because the hardness of the frame film 400 is relatively high, the film can form a protective frame at the edge of the membrane electrode assembly 100, and the sealing effect is relatively good when the sealing ring is pressed on the surface of the membrane electrode assembly.

Further, the frame film 400 wraps the sides and the periphery of the membrane electrode assembly 100. The above-described membrane material may be provided on both the anode-side surface and the cathode-side surface of the membrane electrode assembly 100, with both the membrane materials being extended and bonded radially outward. In this way, the membrane electrode assembly 100 is prevented from being subjected to a large pressure in a water absorption state to cause water to seep out from the edge, thereby reducing the risk of short circuit and improving safety.

Preferably, in some embodiments, the material of the frame film is PI or PEN. A PI or PEN film may be bonded to the surface of the membrane electrode assembly 100 using a heat sensitive adhesive.

Referring to fig. 14, preferably, a first protrusion 410 extends outward from an edge of the frame 400, the first protrusion 410 is provided with a positioning hole, and the first protrusion 410 corresponds to the positions of the protrusions on the cathode plate 240 of the cathode assembly 200 and the anode plate 330 of the anode assembly 300. The membrane assembly can be well positioned by the positioning pins penetrating through the positioning holes at the corresponding positions, and the short circuit caused by the contact between lugs of the cathode/anode plate can be avoided due to the lugs. Preferably, the frame 400 is slightly larger than the cathode/anode plate to ensure good insulation.

Referring to fig. 5-7, the cathode assembly 200 includes a cathode diffusion layer 210, a cathode flow field plate 220, and a cathode plate 240. The cathode diffusion layer 210, the cathode flow field plate 220, and the cathode plate 240 are arranged in this order along the mea 100 to a direction away from the anode assembly 300. The cathode diffusion layer 210 is attached to one side surface of the membrane electrode assembly 100. The cathode diffusion layer 210 is a porous material that functions to conduct electricity, transport water and gas during electrolysis. The cathode diffusion layer 210 may be made of porous titanium, carbon cloth, carbon paper, or the like. The cathode flow field plate 220 uses a titanium or stainless steel material for product delivery. The cathode plate 240 is used for fixedly mounting the cathode diffusion layer 210 and the cathode flow field plate 220, and the cathode plate 240 may be made of 316L stainless steel material which can resist hydrogen.

Referring to fig. 1, 3 and 7, in some embodiments, hydrogen gas flows out of the electrolytic cell 10 from the center of the cathode plate 240 of the cathode assembly 300 in each electrolytic cell 10. That is, the hydrogen gas generated at the cathode in each electrolytic cell 10 flows around the inside of the cathode assembly 200 toward the central region and is discharged out of the electrolytic cell 10. Therefore, the internal pressure can be well balanced, the pressure in each area in the radial direction is balanced, and the pressure eccentricity caused by the high pressure of the hydrogen is not easy to occur, so that the sealing effect is enhanced. Specifically, the center of the cathode flow field plate 220 is provided with a first through hole 221, the center of the cathode plate 240 is provided with a second through hole 245, and the two through holes are correspondingly and mutually communicated and are positioned at the center of each component. The first through hole 221 and the second through hole 245 form a hydrogen outlet first section 270, and hydrogen generated at the cathode side flows through the first through hole 221 and the second through hole 245 in sequence and is discharged.

Further, in some embodiments, in each electrolytic cell 10, the hydrogen flowing out of the second through hole 245 in the center of the cathode plate 240 flows radially outward along the cathode plate 240, reaches the outside of the electrolytic cell 10, converges, and then is discharged out of the stack. The outer area is only provided with the cathode plate 240, the anode plate 330 and other parts, and the hydrogen is led to the outer side and then discharged, so that hole positions are prevented from being formed in the center positions of all the parts of the pile, and the sealing difficulty can be reduced. Specifically, the outer surface of the cathode plate 240 is provided with a second hydrogen outlet section 246 extending along the radial direction and communicated with the second through hole 245, the outer side of each electrolytic cell 10 is provided with a hole site running through along the axial direction to form a third hydrogen outlet section 260, and the third hydrogen outlet section 260 is communicated with the second hydrogen outlet section 246.

Preferably, a plurality of hydrogen outlet second sections 246 are arranged on the outer surface of the cathode plate 240, a plurality of hydrogen outlet third sections 260 are arranged on the outer side of each electrolytic cell, and each hydrogen outlet third section 260 is communicated with the outer end of the corresponding hydrogen outlet second section 246. In this way, the hydrogen outflow rate can be increased, and if one of the hydrogen outlet second segments 246 is blocked, the hydrogen discharge is not affected. Preferably, the plurality of hydrogen outlet second sections 246 are uniformly distributed along the circumferential direction, and the plurality of hydrogen outlet third sections 260 are also uniformly distributed along the circumferential direction, so that the pressure in each radial region can be balanced, and the pressure eccentricity caused by the high pressure of hydrogen is not easy to occur, thereby enhancing the sealing effect.

Referring to fig. 3, in summary, the hydrogen outlet includes a first hydrogen outlet section 270, a second hydrogen outlet section 246 and a third hydrogen outlet section 260, and hydrogen in each electrolytic cell 10 flows out of the electrolytic cell 10 through the first hydrogen outlet section 270. The hydrogen gas flowing out of the first section 270 of the hydrogen outlet of the plurality of electrolysis cells 10 flows outwards along the respective second section 246 of the hydrogen outlet and is discharged out of the stack after being collected at the third section 260 of the hydrogen outlet.

Referring to fig. 5 to 7, in some embodiments, the cathode flow field plate 220 has a plurality of annular flow channels 222 and linear flow channels 223 on the surface facing the cathode diffusion layer 210. The annular flow passage 222 extends annularly, the linear flow passage 223 extends along the radial direction, the linear flow passage 223 passes through the positions of the plurality of annular flow passages 222 and is communicated with the annular flow passage 222, and the end part of at least part of the linear flow passage 223 is communicated with the first through hole 221. The hydrogen gas generated at the cathode side reaches the straight flow channels 223 and the annular flow channels 222 from the cathode diffusion layer 210, and the hydrogen gas in the annular flow channels 222 flows along an annular path, enters the straight flow channels 223, flows radially inward, and finally enters the first through holes 221.

In the embodiment shown in fig. 7, the end of the partial straight flow passage 223 communicates with the first through hole 221, and the end of the partial straight flow passage 223 does not extend radially inward to the first through hole 221. Alternatively, the ends of all the linear flow channels 223 may be extended to the first through holes 221 in the radial direction and communicate with the first through holes 221.

Referring to fig. 6 to 7, in some embodiments, a cathode receiving groove 241 is disposed on a surface of the cathode plate 240 facing the mea 100, the cathode receiving groove 241 is located in a central region, the cathode diffusion layer 210 and the cathode flow field plate 220 are both disposed in the cathode receiving groove 241, the cathode assembly 200 is fixedly connected to the anode assembly 300, so that the cathode plate 240 is pressed toward the mea 100, and the cathode diffusion layer 210 and the cathode flow field plate 220 are tightly attached to the mea 100. An annular first sealing groove 242 is formed in the outer ring of the cathode accommodating groove 241, and a sealing ring is disposed in the first sealing groove 242 to enhance the sealing property between the cathode plate 240 and the membrane electrode assembly 100. The edge of the cathode plate 240 further extends outward to form a second lug 247 corresponding to the first lug 410 on the frame 400 and the lug on the anode plate.

Preferably, a resilient conductive element 230 is also provided within the cathode receiving groove 241, the resilient conductive element 230 being located between the cathode plate 240 and the cathode flow field plate 220. The two ends of the elastic conductive element 230 are respectively contacted and abutted with the cathode plate 240 and the cathode flow field plate 220, so that a large gap is generated between the cathode plate 240 and the cathode flow field plate 220 due to the extrusion of hydrogen when the cathode plate is in a high-pressure state, and poor contact or overlarge resistance is caused. The elastic conductive element 230 may be made of metal, and specifically, a copper sheet or a disc spring may be selected.

Further, a protruding portion 243 is disposed on the bottom wall of the cathode accommodating groove 241, a mounting hole 231 is disposed on the elastic conductive element 230, and the elastic conductive element 230 is sleeved on the protruding portion 243 through the mounting hole 231 to achieve positioning. Preferably, a plurality of resilient conductive elements 230 may be provided to further alleviate the problem of poor contact or excessive resistance. Preferably, the plurality of elastic conductive elements 230 are uniformly distributed in a ring shape.

Preferably, the cathode assembly 200 may further include an exhaust hole, which may be any one of the third sections 260 of the hydrogen outlet, before use, nitrogen may be introduced from one of the third sections 260 of the hydrogen outlet and discharged from the other third section 260 of the hydrogen outlet, and the nitrogen may be purged to remove oxygen inside, thereby improving safety.

Referring to fig. 7, it is preferable that the bottom wall of the cathode receiving groove 241 is further provided with a discharge groove 244, the discharge groove 244 passes through the protruding portion 243, and the discharge hole communicates with the discharge groove 244. When using after not opening for the first time or for a long time, need carry out nitrogen gas and sweep, perhaps when the assembly is accomplished the back and carry out the water pressure experiment, if elastic conductive element 230 chooses for use belleville spring, belleville spring is inside to have probably residual air, and discharge groove 244 can be with belleville spring inner space and outside intercommunication, is favorable to gaseous complete discharge.

Referring to fig. 5, 6 and 8, the anode assembly 300 includes an anode diffusion layer 310, an anode flow field plate 320, an anode plate 330, and the like. The anode diffusion layer 310 and the anode flow field plate 320 are both mounted inside the anode plate 330. The anode plate 330 can be made of corrosion-resistant materials such as stainless steel. If the anode side voltage is high, the corrosion potential of the selected metal material may be exceeded at the anode diffusion layer 310, anode flow field plate 320, and anode plate 330, and therefore, it is preferable to plate the surfaces of these components with a noble metal such as gold to improve the corrosion resistance.

Referring to fig. 6, 8 and 9, the anode plate 330 is provided with a seventh through hole 333, the anode diffusion layer 310 is clamped in the seventh through hole 333, and the anode diffusion layer 310 is tightly attached to one side surface of the membrane electrode assembly 100. The anode diffusion layer 310 is a porous material that functions to conduct electricity, transport water and gas during electrolysis. The anode diffusion layer 310 may be made of powdered sintered titanium, which has a higher hardness, less deformation when operating under differential pressure, and a porosity of 30%.

The anode flow field plate 320 is made of titanium or stainless steel and is surface plated with gold to prevent corrosion at high voltages for delivery of products and reactants. The anode flow field plate 320 includes a main portion 321 and a support portion 322, and the main portion 321 is located at a side close to the anode diffusion layer 310. The anode plate 330 is provided with a protruding portion 331 protruding radially inward, and the inside of the protruding portion 331 defines the seventh through hole 333. The anode flow field plate 320 is provided with a fifth through hole 3224 and a sixth through hole 3225.

Referring to fig. 4, the water inlet 360 and the oxygen outlet 370 penetrate all the electrolytic cells 10, and water flows in from the water inlet 360, flows from one end of the stack to the other end, and flows into each electrolytic cell 10 in the process. Oxygen is discharged from the anode side of each cell 10 and collected at an oxygen outlet 370 to exit the stack. Referring to fig. 6, 8 and 9, the fifth through hole 3224 is a portion of the water inlet 360, and the sixth through hole 3225 is a portion of the oxygen outlet 370. The membrane electrode assembly 100 and the anode flow field plate 320 are separated by the anode diffusion layer 310 and the protrusion 331, and the water inlet 360 and the oxygen outlet 370 are located in the region of the protrusion 331.

In some conventional electrolytic cells, the area where the protruding portion 331 is located is a diffusion layer, and the fifth through hole 3224 and the sixth through hole 3225 are separated from the membrane electrode assembly 100 by the diffusion layer, but under high pressure conditions, the strength and hardness of the diffusion layer may be insufficient, and the portions of the membrane electrode assembly 100 around the areas of the fifth through hole 3224 and the sixth through hole 3225 are easily deformed and cracked due to excessive pressing. In the present embodiment, by providing the protruding portion 331 with higher strength and hardness, the fifth through hole 3224 and the sixth through hole 3225 are separated from the membrane electrode assembly 100 by the protruding portion 331, so that the support of the membrane electrode assembly 100 is enhanced, and the possibility of deformation and fracture of the portion of the membrane electrode assembly 100 around the area of the fifth through hole 3224 and the sixth through hole 3225 is reduced.

Referring to fig. 5, 6, 8 and 9, further, the anode flow field plate 320 includes a main body 321 and a supporting portion 322, the main body 321 is located at a side close to the protruding portion 331 and the anode diffusion layer 310, a plurality of hollow grooves 3211 are disposed on the main body 321, a fifth through hole 3224 and a sixth through hole 3225 are disposed on the supporting portion 322, and both the fifth through hole 3224 and the sixth through hole 3225 are communicated with the hollow grooves 3211. The water in the water inlet 360 flows through the hollow groove 3211 from the fifth through hole 3224 to reach the anode diffusion layer 310. In this embodiment, the fifth through hole 3224 and the sixth through hole 3225 and the hollow groove 3211 are respectively disposed on two portions, so that the fifth through hole 3224 and the sixth through hole 3225 are separated from the membrane electrode assembly 100 by the protruding portion 331 and the main body portion 321, the protruding portion 331 and the main body portion 321 jointly enhance the support of the membrane electrode assembly 100, and further reduce the possibility of deformation and fracture of the portion of the membrane electrode assembly 100 around the area of the fifth through hole 3224 and the sixth through hole 3225.

Specifically, the hollow grooves 3211 on the main body 321 are parallel, the supporting portion 322 is provided with a first arc-shaped communicating groove 3221 and a second arc-shaped communicating groove 3222, the first communicating groove 3221 is communicated with the fifth through hole 3224, the second communicating groove 3222 is communicated with the sixth through hole 3225, and the first communicating groove 3221 and the second communicating groove 3222 are both communicated with the edge of the hollow groove 3211. The water flows through the first communicating groove 3221 from the fifth through hole 3224 and then flows to the hollow groove 3211, and the oxygen flows through the second communicating groove 3222 from the hollow groove 3211 and then flows to the sixth through hole 3225.

Referring to fig. 8 and 9, an anode receiving groove 332 is formed on a side of the protruding portion 331 away from the mea 100, the main portion 321 and the supporting portion 322 are disposed in the anode receiving groove 332, and the main portion 321 is closely attached to the anode diffusion layer 310 located in the seventh through hole 333. Specifically, a groove 334 is formed in the anode accommodating groove 332, a first boss 3212 is formed on the body portion 321, a second boss 3223 is formed on the supporting portion 322, and the first boss 3212 and the second boss 3223 are clamped into the groove 334 for positioning. An annular third sealing groove 336 is further formed in the surface of the anode plate 330 close to the membrane electrode assembly 100, and a sealing ring is arranged in the third sealing groove 336 and used for enhancing the sealing performance between the anode plate 330 and the membrane electrode assembly 100. The surface of the anode plate 330 on the side far away from the membrane electrode assembly 100 is further provided with a second annular sealing groove 335 for enhancing the sealing property between the anode plate 330 and the anode electrode 340. The edge of the anode plate 330 further extends outward to form a third lug 337 corresponding to the first lug 410 on the frame 400 and the second lug 247 on the cathode plate 240. First lobe 410 is located between third lobe 337 and second lobe 247.

In addition, a cathode end plate and an anode end plate (not shown) are provided at both ends of the structure shown in fig. 1, and are fixedly connected to each other, thereby pressing the components in each electrolytic cell 10 between the cathode end plate and the anode end plate. And the adjacent plate members are positioned by positioning pins.

As described above, the cathode plate 240, the anode plate 330, and other components are provided with a plurality of sealing grooves, and sealing rings are provided in the sealing grooves. Referring to fig. 12 and 13, the sealing ring 500 is annular, and the first surface 520 of the sealing ring 500 matches the shape of the sealing groove to enhance the fit. For example, in the illustrated embodiment, the first surface 520 is a flat surface, and the groove bottom wall of each of the seal grooves is a flat surface. A second face 530 of the gasket 500 opposite the first face 520 is convex in shape, and when the cell is assembled, the second face 530 is compressed to effect a seal. The sidewall of the sealing ring 500 is further provided with a protrusion 510, and the protrusion 510 will be abutted against the groove sidewall of the sealing groove for fixing the position. In addition, when the sealing ring 500 is subjected to high pressure, a shear force may be applied in a lateral direction (in a width direction of the sealing groove), and therefore, it is desirable to avoid a parting line of the sealing ring 500 from being torn when the sealing ring is subjected to a shear force, for example, the parting line may be disposed at an upper and lower position.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A water electrolysis cell stack, comprising:

2. The water electrolysis cell stack according to claim 1, wherein the cathode assembly is provided with a first section of axially extending hydrogen outlet at a central location.

3. The water electrolysis cell stack according to claim 2, wherein the cathode assembly comprises a cathode plate, a second section of the hydrogen outlet extending along the radial direction is arranged on the outer surface of the cathode plate, the second section of the hydrogen outlet is communicated with the first section of the hydrogen outlet, a third section of the hydrogen outlet is arranged on the outer side of the electrolytic cell, the third section of the hydrogen outlet axially penetrates through the electrolytic cell, and the third section of the hydrogen outlet is communicated with the outer end of the second section of the hydrogen outlet.

4. The water electrolysis cell stack as claimed in claim 3, wherein the outer surface of the cathode plate is provided with a plurality of second sections of hydrogen outlets extending along the radial direction, the electrolytic cell is provided with a plurality of groups of third sections of hydrogen outlets evenly distributed along the circumferential direction, and the third section of each group of hydrogen outlets is respectively communicated with the outer end of the second section of each group of hydrogen outlets.

5. The water electrolysis stack according to claim 2, wherein the cathode assembly further comprises a cathode flow field plate, the hydrogen outlet first section comprises a first through hole located at the center of the cathode flow field plate, the cathode flow field plate is further provided with a plurality of annular flow channels and linear flow channels, the linear flow channels extend along the radial direction and are communicated with the annular flow channels, and the end parts of at least part of the linear flow channels are communicated with the first through hole.

6. The water electrolysis stack according to claim 1 wherein the cathode assembly comprises a cathode plate and a cathode flow field plate with an elastic conductive element disposed therebetween.

7. The water electrolysis cell stack according to claim 6, wherein the cathode plate is provided with a protrusion protruding toward the cathode flow field plate, and the elastic conductive element is sleeved on the protrusion.

8. The water electrolysis stack according to claim 1, wherein the anode assembly comprises an anode diffusion layer, an anode plate and an anode flow field plate, the water electrolysis stack is provided with a water inlet and an oxygen outlet, the anode plate is provided with a protrusion extending radially inward, the membrane electrode assembly and the anode flow field plate are separated by the anode diffusion layer and the anode plate, and the water inlet and the oxygen outlet are both located in the region of the protrusion.

9. The water electrolysis stack according to claim 8, wherein the anode flow field plate comprises a main body part and a support part, the main body part is located on one side of the extension part and the anode diffusion layer, the main body part is provided with a plurality of hollowed-out grooves, the water inlet and the oxygen outlet are arranged on the support part, and the water inlet and the oxygen outlet are both communicated with the hollowed-out grooves.

10. The water electrolysis stack according to claim 1, wherein the membrane electrode assembly comprises a first proton exchange membrane, a second proton exchange membrane, and an interlayer between the first proton exchange membrane and the second proton exchange membrane, the interlayer for reacting hydrogen gas permeating from a cathode side to an anode side to generate hydrogen ions.

11. The water electrolysis stack according to claim 1, wherein the edge of the membrane electrode assembly is wrapped with a frame film, and the frame film has a hardness greater than that of the membrane electrode assembly.