CN113235120B

CN113235120B - Membrane electrode assembly and water electrolysis device

Info

Publication number: CN113235120B
Application number: CN202110342836.XA
Authority: CN
Inventors: 江亚阳; 杨福源; 党健; 李洋洋; 胡松; 王天泽
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2021-03-30
Filing date: 2021-03-30
Publication date: 2022-04-08
Anticipated expiration: 2041-03-30
Also published as: CN113235120A

Abstract

The invention relates to a membrane electrode assembly and a water electrolysis device. The membrane electrode assembly includes: a first proton exchange membrane; a second proton exchange membrane; 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. The water electrolysis device comprises the membrane electrode assembly, and further comprises an anode assembly and a cathode assembly which are respectively positioned on two sides of the membrane electrode assembly. The membrane electrode assembly can be suitable for the environment generating high-pressure hydrogen, so that the hydrogen output pressure of a water electrolysis device comprising the membrane electrode assembly can be increased, and the high-pressure hydrogen can be directly output.

Description

Membrane electrode assembly and water electrolysis device

Technical Field

The present invention relates to the field of water electrolysis technology, and more particularly to a membrane electrode assembly and a water electrolysis apparatus.

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 proton exchange membranes and the electrolysis devices comprising the same are only suitable for the environment generating normal pressure hydrogen, and after the hydrogen is electrolyzed, the generated hydrogen is compressed by a compressor and then is filled into a hydrogen cylinder for storage and transportation. However, hydrogen compressors are expensive and costly to maintain. Therefore, there is a need for an improved structure of a proton exchange membrane and an electrolysis apparatus, which is suitable for high pressure environment, so as to directly output high pressure hydrogen.

Disclosure of Invention

Based on the above, the present invention provides a membrane electrode assembly, which can be applied to an environment where high-pressure hydrogen is generated, so as to increase the hydrogen output pressure of a water electrolysis device including the membrane electrode assembly, thereby directly outputting high-pressure hydrogen.

A membrane electrode assembly comprising:

a first proton exchange membrane;

a second proton exchange membrane;

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 first proton exchange membrane is made of N115, and the second proton exchange membrane is made of XL 100.

In one embodiment, the interlayer is made of platinum or iridium.

When the membrane electrode assembly is applied to an environment with high pressure for outputting hydrogen, the pressure of the cathode side is far greater than that of the anode side, part of hydrogen generated by the cathode can permeate to the anode side through the membrane electrode assembly, and the part of hydrogen can regenerate hydrogen ions under the action of the interlayer after passing through the interlayer, and then reaches the cathode side from the anode side through the membrane electrode assembly again. Through setting up the intermediate layer, can restrain hydrogen permeation volume, reduce the risk that the oxyhydrogen mixes, make this membrane electrode assembly can be applicable to under the environment that produces high-pressure hydrogen.

The invention provides a water electrolysis device which can be suitable for the environment of high-pressure hydrogen, so that the output pressure of the hydrogen can be increased, the high-pressure hydrogen can be directly output, a compressor is not needed for compression, and the cost can be saved.

The water electrolysis device comprises the membrane electrode assembly, and also comprises an anode assembly and a cathode assembly which are respectively positioned at two sides of the membrane electrode assembly.

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.

In one embodiment, the cathode assembly is provided with a hydrogen outlet, and the hydrogen outlet is positioned at the center of the cathode assembly.

In one embodiment, the cathode assembly comprises a cathode flow field plate, a first through hole is formed in the center of the cathode flow field plate, a plurality of annular flow channels and linear flow channels are further formed in the cathode flow field plate, the linear flow channels extend in the radial direction and are communicated with the annular flow channels, and the end portions of at least some 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 anode flow field plate is provided with a water inlet and an oxygen outlet, the anode plate is provided with a protrusion portion protruding 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 a region where the protrusion portion is located.

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.

When the water electrolysis device is applied to an environment with high pressure for outputting hydrogen, the pressure of the cathode side is far greater than that of the anode side, part of hydrogen generated by the cathode can permeate to the anode side through the membrane electrode assembly, and the part of hydrogen can regenerate hydrogen ions under the action of an interlayer after passing through the interlayer of the membrane electrode assembly, and then reaches the cathode side from the anode side through the membrane electrode assembly again. Through set up the intermediate layer in membrane electrode assembly, can restrain the hydrogen infiltration volume, reduce the risk that oxyhydrogen mixes, make this water electrolysis device can be applicable to under the environment that produces high-pressure hydrogen to can increase hydrogen output pressure, direct output high-pressure hydrogen need not to use the compressor to compress, can save the cost.

Drawings

FIG. 1 is a schematic view of the overall structure of a water electrolysis apparatus according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the water electrolysis apparatus of FIG. 1;

FIG. 3 is an enlarged view of a portion of FIG. 2 at A;

FIG. 4 is an exploded view of the cathode side of the water electrolysis apparatus of FIG. 1;

FIG. 5 is an exploded view of the anode side of the water electrolysis apparatus of FIG. 1;

FIG. 6 is a schematic diagram of the construction of an anode plate of the water electrolysis apparatus of FIG. 1;

FIG. 7 is a schematic view of the membrane electrode assembly of the water electrolysis apparatus of FIG. 1;

FIG. 8 is a schematic structural view of a membrane electrode assembly and a frame membrane of the water electrolysis apparatus shown in FIG. 1;

FIG. 9 is a schematic view of a seal ring according to an embodiment of the present invention;

FIG. 10 is a partial cross-sectional view of the seal ring of FIG. 9;

FIG. 11 is a top view of a bezel film in an embodiment of the present invention;

FIG. 12 is a schematic view of the position of the vent holes in an embodiment of the invention.

Reference numerals:

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 member 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 second lug 246, a cathode electrode 250, a third through-hole 251, a cathode cable connection portion 252, a cathode end plate 260, a fourth through-hole 261, a hydrogen gas outlet 270, a gas discharge hole 280;

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 eighth through hole 341, the ninth through hole 342, the anode cable connecting part 343, the anode end plate 350, the tenth through hole 351, the eleventh through hole 352, 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 to 3, a water electrolysis apparatus according to an embodiment of the present invention includes a membrane electrode assembly 100, a cathode assembly 200, and an anode assembly 300. The cathode assembly 200 and the anode assembly 300 are respectively positioned at both sides of the membrane electrode assembly 100. The water electrolysis device can electrolyze water to generate hydrogen and oxygen. Specifically, water enters the water electrolysis device from a water inlet 360 at the anode where oxygen gas and hydrogen ions are generated, the oxygen gas exits from an oxygen outlet 370 at the anode, the hydrogen ions pass through the membrane electrode assembly 100 to the cathode side, hydrogen gas is generated at the cathode and exits from a hydrogen outlet 270. When the water electrolysis device is used, the pressure of the hydrogen output can be changed by changing a pressure regulating valve or a flow valve connected with the hydrogen outlet 270. If the hydrogen output pressure is increased, the hydrogen pressure on the cathode side is also increased. The water electrolysis device can adapt to the high-pressure state of the cathode side by improving a plurality of structures in the water electrolysis device.

When the water electrolysis device outputs high-pressure hydrogen, the cathode side is in a high-pressure state, the pressure is far greater than that of the anode side, the water electrolysis device operates in a differential pressure mode, the hydrogen generated by the cathode permeates towards the anode side under the action of the differential pressure, the mixed concentration of the hydrogen and the oxygen on the anode side is high, and great risk exists. Referring to fig. 7, 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 water electrolysis device 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 IrO oxide thereof₂(iridium oxide). 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. 8, 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. 11, 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. 2-4, the cathode assembly 200 includes a cathode diffusion layer 210, a cathode flow field plate 220, a cathode plate 240, a cathode electrode 250, and a cathode end plate 260. The cathode diffusion layer 210, the cathode flow field plate 220, the cathode plate 240, the cathode electrode 250, and the cathode end plate 260 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. The cathode electrode 250 is made of copper, a cathode cable connecting portion 252 extending outwards is arranged on the cathode electrode 250, three large holes arranged on the cathode electrode are bolt holes, and two small holes are connected with a cable through small bolts and used for being connected with an external power supply and electrified. The cathode end plate 260 protects the above components from the outside. An insulating varnish is coated between the cathode terminal plate 260 and the cathode electrode 250 to achieve insulation. The corresponding positions of the cathode plate 240, the cathode electrode 250 and the cathode end plate 260 are provided with positioning holes, and positioning is realized by the positioning pins penetrating through the positioning holes.

Preferably, in some embodiments, the hydrogen outlet 270 is located in a central location of the cathode assembly 200. That is, hydrogen generated from the cathode flows and is discharged from the periphery of the cathode assembly 200 toward the central region. 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, the center of the cathode electrode 250 is provided with a third through hole 251, and the center of the cathode end plate 260 is provided with a fourth through hole 261. The first through hole 221, the second through hole 245, the third through hole 251 and the fourth through hole 261 form a hydrogen outlet 270, and the four through holes are corresponding in position and are communicated with each other, and are all located at the central position of each component. The hydrogen generated at the cathode side flows through the first through hole 221, the second through hole 245, the third through hole 251, and the fourth through hole 261 in sequence and is discharged.

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 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 in the annular flow channels 222 flows along an annular path, enters the straight flow channels 223, flows radially inward, finally enters the first through holes 221, and is discharged out of the cathode assembly 200.

In the embodiment shown in fig. 4, 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. 2 to 4, 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 plate 240 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 246, which corresponds 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.

Referring to fig. 12, preferably, the cathode assembly 200 may further include an exhaust hole 280, which may be disposed in a manner that the hydrogen outlet 270 is referred to, and corresponding and communicated hole sites are disposed on each component. Before use, nitrogen gas may be introduced from the hydrogen outlet 270, discharged from the exhaust hole 280, and purged with nitrogen gas to remove oxygen gas from the inside, thereby improving safety. After purging is complete, the corresponding valve is closed and hydrogen is still vented from the hydrogen outlet 270 during use.

Referring to fig. 4, 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. 2, 3, 5 and 6, the anode assembly 300 includes an anode diffusion layer 310, an anode flow field plate 320, an anode plate 330, an anode electrode 340, and an anode terminal plate 350. The anode diffusion layer 310 and the anode flow field plate 320 are both installed inside the anode plate 330, and the anode plate 330, the anode electrode 340 and the anode end plate 350 are sequentially arranged along the direction from the membrane electrode assembly 100 to the cathode assembly 200. The anode plate 330 is used for fixedly mounting the anode diffusion layer 310, the anode flow field plate 320 and other components, and the anode plate 330 can be made of corrosion-resistant materials such as stainless steel. The anode electrode 340 is made of copper, an anode cable connecting portion 343 extending outwards is arranged on the anode electrode 340, three large holes arranged on the anode cable connecting portion are bolt holes, and two small holes are connected with a cable through small bolts and used for being connected with an external power supply and electrified. The anode terminal plate 350 protects the above-mentioned components from the outside. An insulating varnish is coated between the anode terminal plate 350 and the anode electrode 340 to achieve insulation. The anode plate 330, the anode electrode 340 and the anode end plate 350 are provided with positioning holes at corresponding positions, and positioning is realized by the positioning pins penetrating through the positioning holes. 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.

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. As shown in fig. 2 and 3, the anode flow field plate 320 is provided with a fifth through hole 3224 and a sixth through hole 3225, the anode electrode 340 is provided with an eighth through hole 341 and a ninth through hole 342, and the anode end plate 350 is provided with a tenth through hole 351 and an eleventh through hole 352. The fifth through hole 3224, the eighth through hole 341 and the tenth through hole 351 correspond in position and communicate with each other to form the water inlet 360. The sixth through hole 3225 and the ninth through hole 342 correspond to and communicate with the eleventh through hole 352 to form an 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 water electrolysis apparatuses, the area where the protrusion 331 is located is a diffusion layer, and the water inlet 360 and the oxygen outlet 370 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 membrane electrode assembly 100 is easily deformed and broken at the area where the water inlet 360 and the oxygen outlet 370 are located due to excessive pressing. In this embodiment, by providing the protruding portion 331 with higher strength and hardness, the water inlet 360 and the oxygen outlet 370 are separated from the membrane electrode assembly 100 by the protruding portion 331, so as to enhance the support of the membrane electrode assembly 100 and reduce the possibility of deformation and rupture of the membrane electrode assembly 100 in the region of the water inlet 360 and the oxygen outlet 370.

Referring to fig. 2, fig. 3, fig. 5 and fig. 6, 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 the fifth through hole 3224 and the sixth through hole 3225 are both communicated with the hollow grooves 3211. The water introduced from 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, the sixth through hole 3225 and the hollow groove 3211 are respectively disposed on two portions, so that the water inlet 360 and the oxygen outlet 370 are separated from the membrane electrode assembly 100 by the protrusion 331 and the main body 321, and the protrusion 331 and the main body 321 jointly enhance the support of the membrane electrode assembly 100, thereby further reducing the possibility of deformation and fracture of the portions of the membrane electrode assembly 100 located in the regions of the water inlet 360 and the oxygen outlet 370.

Specifically, the hollow groove 3211 of the main body 321 is flat, 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 communicating hole 3224, the second communicating groove 3222 is communicated with the sixth communicating 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. 5 and fig. 6, 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 246 on the cathode plate 240. First lug 410 is located between third lug 337 and second lug 246.

Referring to fig. 1 and 2, the cathode end plate 260 is fixedly coupled to the anode end plate 350, thereby fixedly coupling and compressing the respective components between the cathode end plate 260 and the anode end plate 350. The positioning pins are used for positioning between the cathode plate 240 and the cathode end plate 260, between the cathode plate 240 and the anode plate 330, and between the anode plate 330 and the anode end plate 350.

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. 9 and 10, 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 water electrolysis apparatus is assembled, the second face 530 is compressed to achieve sealing. 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 apparatus, comprising: the membrane electrode assembly also comprises an anode assembly and a cathode assembly which are respectively positioned at two sides of the membrane electrode assembly; the membrane electrode assembly includes:

a first proton exchange membrane;

a second proton exchange membrane;

an interlayer positioned between the first proton exchange membrane and the second proton exchange membrane, the interlayer configured to react hydrogen gas permeating from a cathode side to an anode side of the membrane electrode assembly under a pressure differential to generate hydrogen ions.

2. The water electrolysis device according to claim 1, wherein the first proton exchange membrane is made of N115 and the second proton exchange membrane is made of XL 100.

3. The water electrolysis apparatus of claim 1, wherein the interlayer is made of platinum or iridium.

4. The water electrolysis device 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.

5. The water electrolysis device according to claim 4, wherein the membrane electrode assembly is provided with membrane materials on the anode side surface and the cathode side surface, and the two membrane materials extend outwards along the radial direction and are bonded to form the frame film wrapping the side surfaces and the peripheral surface of the membrane electrode assembly.

6. The water electrolysis device according to claim 1, wherein the cathode assembly is provided with a hydrogen outlet, and the hydrogen outlet is positioned at the center of the cathode assembly.

7. The water electrolysis device according to claim 6, wherein the cathode assembly comprises a cathode flow field plate, a first through hole is formed in the center of the cathode flow field plate, a plurality of annular flow channels and linear flow channels are further formed in the cathode flow field plate, 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.

8. The water electrolysis device of claim 1, wherein the cathode assembly comprises a cathode plate and a cathode flow field plate with an elastic conductive element disposed therebetween.

9. The water electrolysis device according to claim 8, 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.

10. The water electrolysis device according to claim 1, wherein the anode assembly comprises an anode diffusion layer, an anode plate and an anode flow field plate, the anode flow field plate is provided with a water inlet and an oxygen outlet, the anode plate is provided with a radially inwardly extending protrusion, 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.

11. The water electrolysis device according to claim 10, 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.