CN118223054A

CN118223054A - Electrolytic tank

Info

Publication number: CN118223054A
Application number: CN202410644101.6A
Authority: CN
Inventors: 张琪; 姜天豪; 胡鹏; 毕飞飞; 蓝树槐
Original assignee: Shanghai Zhizhen New Energy Co Ltd
Current assignee: Shanghai Zhizhen New Energy Co Ltd
Priority date: 2024-05-22
Filing date: 2024-05-22
Publication date: 2024-06-21

Abstract

The application discloses an electrolytic cell, which comprises a membrane electrode, a polar plate and a diffusion layer; the diffusion layer is positioned between the membrane electrode and the polar plate along a first direction x, and comprises a body and a first bulge connected with the body, wherein the first bulge is positioned on one side of the body facing the polar plate, the first bulge is a metal particle layer, and the body is a metal felt layer; the polar plate is provided with a groove, and the first bulge is positioned in the groove, so that a flow passage is arranged between the first bulge and the inner wall of the groove. In the working process of the electrolytic tank, the body is contacted with water in the flow channel through the first bulge, so that the contact area of the body and the water is enlarged, and the water in the flow channel can diffuse into the body through the first bulge. Specifically, part of water in the flow channel can permeate into the first bulge through the gaps between two adjacent metal particles in the metal particle layer, and flow in the first bulge along the direction of the first direction x towards the membrane electrode, so that the absorption efficiency of the diffusion layer on water is improved, and the transmission performance of the diffusion layer on water is improved.

Description

Electrolytic tank

Technical Field

The application relates to the technical field of electrolytic tanks, in particular to an electrolytic tank.

Background

In the internal structure of the electrolytic cell, a gas diffusion layer is used as one of the main components of the electrolytic cell, one side of the gas diffusion layer is contacted with a membrane electrode, and the other side is contacted with a polar plate, so that the effect of transmitting gas and moisture is achieved. In the process of the operation of the electrolytic cell, the gas diffusion layer can transmit water in the polar plate runner to one side contacted with the membrane electrode, so that the water is ionized under the action of the catalyst, and the reaction is carried out to generate gas. However, in the prior art, the gas diffusion layer has poor water transport performance.

Disclosure of Invention

In view of the above, the present application provides an electrolytic cell to solve the technical problem of poor water transmission performance of the gas diffusion layer in the prior art.

The application provides an electrolytic cell, which comprises a membrane electrode, a polar plate and a diffusion layer, wherein the polar plate is provided with a groove, the diffusion layer is positioned between the membrane electrode and the polar plate along a first direction x, the diffusion layer comprises a body and a first bulge connected with the body, and the first bulge is positioned on one side of the body facing the polar plate; the first protrusions are metal particle layers, the first protrusions are located in the grooves, and flow channels are formed between the first protrusions and the inner walls of the grooves.

In the embodiment of the application, along the first direction x, a first bulge is arranged on one side of the diffusion layer body, facing the polar plate, and a groove is arranged on one side of the polar plate, facing the diffusion layer, and the first bulge can be positioned in the groove in the process of assembling the polar plate and the diffusion layer, so that a flow channel is formed between the first bulge and the inner wall of the groove, and water flowing into the electrolytic tank can flow in the flow channel in the process of working the electrolytic tank.

When the first bulge is positioned in the groove, the body can be contacted with water through the first bulge, so that the contact area of the body and the water is enlarged, and the water in the flow channel can diffuse towards the inside of the body through the first bulge. Specifically, because the first protrusion is the metal particle layer, when first protrusion is located the recess, part of water in the runner can permeate to in the first protrusion through the clearance between two adjacent metal particles in the metal particle layer to flow along direction x towards the membrane electrode in the first protrusion, thereby be favorable to accelerating diffusion layer to the absorption efficiency of water, promote diffusion layer to the transmission performance of water. Therefore, the diffusion layer in this embodiment can enlarge the contact area with water through the first protrusion, so that water in the groove can flow towards the membrane electrode along the first direction x through the first protrusion, which is beneficial to accelerating the absorption efficiency of the diffusion layer to water and improving the transmission performance of the diffusion layer to water.

In a possible embodiment, the flow channel comprises at least a first flow channel, which is enclosed by at least the first protrusion and the bottom wall of the recess in the first direction x.

In a possible embodiment, the flow channel further comprises a second flow channel, and at least one side wall of the first protrusion and at least one side wall of the groove enclose at least one second flow channel along the second direction y.

In one possible embodiment, along the first direction x, the cross-sectional area of the first protrusion is S1, the cross-sectional area of the groove is S2, and S1 and S2 satisfy: S1/S2 is more than or equal to 0.3 and less than or equal to 0.7.

In one possible embodiment, along the first direction x, the height of the first protrusion is H1, the depth of the groove is H2, and H1 and H2 satisfy: H1/H2 is more than or equal to 0.1 and less than or equal to 1.

In one possible embodiment, the first protrusion abuts at least one side wall of the recess in the second direction y.

In one possible embodiment, the first protrusion includes a plurality of first metal particles, the first metal particles having a diameter D1, and D1 satisfies: d1 is more than or equal to 70 mu m and less than or equal to 100 mu m.

In one possible embodiment, the first protrusion has one or more of a rectangular, circular and trapezoidal cross-sectional shape along the first direction x.

In one possible embodiment, the diffusion layer further comprises a second protrusion connected to the body, the second protrusion being located on a side of the body facing the membrane electrode in the first direction x; the second protrusions are spaced apart from each other in the second direction y.

In a possible embodiment, the second protrusion is a metal particle layer, and the projection of the second protrusion along the first direction x at least partially coincides with the projection of the groove along the first direction x.

In one possible embodiment, the projection of the second protrusion along the first direction x is located within the projection range of the groove along the first direction x.

In one possible embodiment, the diffusion layer further includes a third protrusion connected to the body, the third protrusion being located on a side of the body facing the membrane electrode along the first direction x, the third protrusion being located between two adjacent second protrusions along the second direction y, and a projection of the third protrusion along the first direction x at least partially coincides with a projection of the first protrusion along the first direction x.

In one possible embodiment, along the second direction y, there is a channel between the adjacent second and third protrusions.

In one possible embodiment, the through-flow cross-sectional area of the channel is S3, and S3 satisfies: 0.6mm ²≤S3≤25mm².

In one possible embodiment, the first protrusion includes a plurality of first metal particles, the second protrusion includes a plurality of second metal particles, a first gap is provided between adjacent first metal particles, a second gap is provided between adjacent second metal particles, and the first gap is larger than the second gap.

In one possible embodiment, the body has a third gap, the third gap being greater than the second gap, the first gap being greater than the third gap; the third gap gradually decreases along the direction of the polar plate towards the membrane electrode.

In one possible embodiment, the first protrusions and the second protrusions are each formed on the body by screen printing.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a diffusion layer and a plate structure according to the present application;

FIG. 2 is a schematic view of the diffusion layer of FIG. 1;

fig. 3 is a cross-sectional view of fig. 1 along a first direction x;

FIG. 4 is a cross-sectional view of the second protrusion in the first embodiment;

FIG. 5 is a cross-sectional view of a second protrusion in a second embodiment;

FIG. 6 is a cross-sectional view of the third protrusion in the first embodiment;

FIG. 7 is a cross-sectional view of a third protrusion in a second embodiment;

FIG. 8 is a schematic structural view of first and second metal particles;

FIG. 9 is a schematic view of a third flow path;

FIG. 10 is a cross-sectional view of a second protrusion in a third embodiment;

Fig. 11 is a cross-sectional view of a third protrusion in a third embodiment.

Reference numerals illustrate:

1-a membrane electrode;

2-polar plates;

21-grooves;

211-flow channel;

211 a-a first flow channel;

211 b-a second flow channel;

211 c-a third flow channel;

A 3-diffusion layer;

31-a first bump;

311-first metal particles;

32-a second bump;

321-second metal particles;

33-a third protrusion;

34-body;

35-channel.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.

Detailed Description

For a better understanding of the technical solution of the present application, the following detailed description of the embodiments of the present application refers to the accompanying drawings.

It should be understood that the described embodiments are merely some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The terminology used in the embodiments of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be understood that the term "and/or" as used herein is merely one way of describing an association of associated objects, meaning that there may be three relationships, e.g., a and/or b, which may represent: the first and second cases exist separately, and the first and second cases exist separately. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

The embodiment of the application provides an electrolytic cell, as shown in fig. 1,2 and 3, comprising a membrane electrode 1, a pole plate 2 and a diffusion layer 3, the diffusion layer 3 being located between the membrane electrode 1 and the pole plate 2 in a first direction x, and the diffusion layer 3 comprising a body 34 and a first protrusion 31 connected to the body 34, the first protrusion 31 being located on the side of the body 34 facing the pole plate 2. The first protrusion 31 is a metal particle layer, the body 34 is a metal felt layer, the electrode plate 2 has a groove 21, and the first protrusion 31 is located in the groove 21 along the first direction x, so that a flow passage 211 is formed between the first protrusion 31 and an inner wall of the groove 21.

In the embodiment of the present application, along the first direction x, a first protrusion 31 is provided on a side of the body 34 of the diffusion layer 3 facing the electrode plate 2, a groove 21 is provided on a side of the electrode plate 2 facing the diffusion layer 3, and the first protrusion 31 can be located in the groove 21 during the assembly process of the electrode plate 2 and the diffusion layer 3, so that a flow channel 211 is formed between the first protrusion 31 and the inner wall of the groove 21, and water flowing into the electrolytic tank can flow in the flow channel 211 during the operation process of the electrolytic tank.

When the first protrusion 31 is positioned in the groove 21, the body 34 can be contacted with water through the first protrusion 31, thereby enlarging the contact area of the body 34 with the water, so that the water in the flow passage 211 can be diffused into the body 34 through the first protrusion 31. Specifically, since the first protrusion 31 is a metal particle layer, when the first protrusion 31 is located in the groove 21, part of water in the flow channel 211 can permeate into the first protrusion 31 through gaps between two adjacent metal particles in the metal particle layer, and flow in the first protrusion 31 along the first direction x towards the direction of the membrane electrode 1, thereby being beneficial to accelerating the absorption efficiency of the diffusion layer 3 on water and improving the transmission performance of the diffusion layer 3 on water.

Therefore, the diffusion layer 3 in this embodiment can enlarge the contact area with water through the first protrusions 31, so that the water in the grooves 21 can flow toward the membrane electrode 1 along the first direction x through the first protrusions 31, which is beneficial to accelerating the absorption efficiency of the diffusion layer 3 on water and improving the transmission performance of the diffusion layer 3 on water.

In one possible embodiment, the first protrusion 31 and the groove 21 may be linear or curved, i.e. the shape of the first protrusion 31 is the same as the shape of the groove 21, so as to be more convenient and quick in the process of assembling the two.

In a specific embodiment, as shown in fig. 3, the first protrusion 31 abuts at least one side wall of the recess 21 along the second direction y.

In the embodiment of the application, when the first protrusion 31 is located in the groove 21, at least part of the first protrusion 31 can be abutted against the side wall of the groove 21, so that concave-convex matching can be realized between the groove 21 and the first protrusion 31, which is beneficial to reducing the possibility of mutual separation between the polar plate 2 and the diffusion layer 3 and improving the stability and reliability of connection between the polar plate 2 and the diffusion layer 3. Specifically, the grooves 21 and the first protrusions 31 can extend along the third direction z and are arranged at intervals along the second direction y, so that after the grooves 21 and the first protrusions 31 are matched, the relative movement of the polar plates 2 and the diffusion layers 3 along the second direction y can be limited, the connection between the polar plates 2 and the diffusion layers 3 is more stable and reliable, the positioning effect can be achieved in the process of connecting the polar plates 2 and the diffusion layers 3, the assembly difficulty between the polar plates and the diffusion layers is reduced, the assembly time is shortened, and the assembly efficiency of the electrolytic tank is improved. And when the runner 211 for circulating water is formed between the first protrusion 31 and the inner wall of the groove 21, the possibility that the first protrusion 31 and the groove 21 are influenced by water flowing to cause relative movement along the second direction y can be reduced, so that the structural stability of the electrolytic cell is further improved, and the stability of the electrolytic cell in the working process is ensured.

Therefore, the diffusion layer 3 in this embodiment can be matched with the recess 21 of the polar plate 2 in a concave-convex manner through the first protrusion 31, so that the assembly difficulty between the diffusion layer 3 and the polar plate 2 is low, the assembly time of the diffusion layer 3 and the polar plate is shortened, and the overall assembly efficiency of the electrolytic cell is improved. Meanwhile, the concave-convex fit between the first protrusion 31 and the groove 21 can also limit the relative movement of the diffusion layer 3 and the polar plate 2 along the second direction y, so that the connection stability between the diffusion layer 3 and the polar plate 2 is improved, and the safety and reliability of the electrolytic cell in the working process are improved.

In a specific embodiment, as shown in fig. 3 and 4, the flow channel 211 includes at least a first flow channel 211a, and along the first direction x, at least the first protrusion 31 and the bottom wall of the groove 21 enclose the first flow channel 211a.

In the embodiment of the present application, when the first protrusion 31 is located in the flow channel 211, the first protrusion 31 and the bottom wall of the groove 21 and the side wall of the groove 21 together form a first flow channel 211a, so that water in the first flow channel 211a can permeate into the first protrusion 31 along the first direction x and the second direction y at the same time, and flow towards the membrane electrode 1 along the first direction x through the first protrusion 31, so as to realize the transmission of water by the diffusion layer 3, therefore, when the first flow channel 211a is surrounded by the first protrusion 31, the bottom wall of the groove 21 and the side wall of the groove 21 together, the contact area between the first protrusion 31 and the water is larger, which is favorable for accelerating the transmission efficiency of water by the diffusion layer 3, thereby improving the transmission performance of water by the diffusion layer 3. Or when the first protrusion 31 is located in the flow channel 211, the first protrusion 31 and the bottom wall of the groove 21 may enclose a first flow channel 211a, so that water in the first flow channel 211a can permeate into the first protrusion 31 along the first direction x, and continuously flow along the first direction x towards the membrane electrode 1 through the first protrusion 31, so that the possibility that water moves along the second direction y in the diffusion process is reduced, the time for diffusing water to the membrane electrode 1 is shortened, the flow speed of water in the diffusion layer 3 is increased, and the water transmission performance of the diffusion layer 3 is improved.

In a specific embodiment, as shown in fig. 3, the flow channel 211 further includes a second flow channel 211b, and along the second direction y, the first protrusion 31 and at least one side wall of the groove 21 enclose at least one second flow channel 211b.

In this embodiment of the present application, when the first protrusion 31 is located in the flow channel 211, the first protrusion 31 and at least one side wall of the groove 21 may enclose at least one second flow channel 211b, so that water in the second flow channel 211b can permeate into the first protrusion 31 from at least one side of the first protrusion 31 along the second direction y, and diffuse toward the membrane electrode 1 along the first direction x through the first protrusion 31, and meanwhile, water in the second flow channel 211b can diffuse into the body 34 directly along the first direction x, so as to realize the water transmission of the diffusion layer 3. Therefore, when the first protrusion 31 and at least one side wall of the groove 21 enclose at least one second flow channel 211b, water in the second flow channel 211b can flow along the first direction x towards the membrane electrode 1 through the first protrusion 31, and can also flow along the first direction x towards the membrane electrode 1 through the body 34 at the same time, which is beneficial to accelerating the diffusion speed of water in the diffusion layer 3, thereby improving the water transmission performance of the diffusion layer 3.

In one possible embodiment, as shown in fig. 3, when the first protrusion 31 is located in the groove 21, at least part of the first protrusion 31 can abut against the inner wall of the groove 21, at this time, the first protrusion 31 and the bottom wall of the groove 21 enclose a first flow channel 211a, and at the same time, the first protrusion 31 and at least one side wall of the groove 21 enclose at least one second flow channel 211b, so that water in the flow channel 211 can flow in the first direction x towards the membrane electrode 1 through the first protrusion 31, and can also flow in the first direction x towards the membrane electrode 1 through the first protrusion 31 after penetrating from at least one first protrusion 31 into the first protrusion 31 in the second direction y, so as to realize the transmission of water in the flow channel 211 by the diffusion layer 3. Therefore, in the present embodiment, the diffusion layer 3 can enclose the plurality of flow channels 211 through the first protrusions 31 and the grooves 21, so that water in each flow channel 211 can diffuse towards the direction close to the membrane electrode 1 through different flow modes at the same time, thereby improving the transmission efficiency of the diffusion layer 3 to water, improving the generation efficiency of gas at the membrane electrode 1, and further being beneficial to improving the working efficiency of the electrolytic tank.

In a specific embodiment, as shown in fig. 3, along the first direction x, the cross-sectional area of the first protrusion 31 is S1, the cross-sectional area of the groove 21 is S2, and S1 and S2 satisfy: S1/S2 is more than or equal to 0.3 and less than or equal to 0.7.

In the embodiment of the present application, the ratio S1/S2 of the cross-sectional area S1 of the first protrusion 31 to the cross-sectional area S2 of the groove 21 may be specifically 0.3, 0.33, 0.35, 0.37, 0.4, 0.43, 0.45, 0.47, 0.5, 0.53, 0.55, 0.57, 0.6, 0.63, 0.65, 0.67, 0.7, etc.

When the ratio of the sectional area S1 of the first protrusion 31 to the sectional area S2 of the groove 21 is too small (e.g., S1/S2 is smaller than 0.3), the first protrusion 31 occupies less space in the groove 21, so that the contact area of the first protrusion 31 with the water in the flow channel 211 is smaller, resulting in lower absorption capacity of the first protrusion 31 for water and thus lower transmission capacity of the diffusion layer 3 for water.

When the ratio of the cross-sectional area S1 of the first protrusion 31 to the cross-sectional area S2 of the groove 21 is too large (e.g., S1/S2 is greater than 0.7), the space occupied by the first protrusion 31 in the groove 21 is large, so that the space for circulating water in the groove 21 is small, and the water flow in the groove 21 is reduced, thereby affecting the working efficiency of the electrolytic cell.

Therefore, when the ratio of the sectional area S1 of the first protrusion 31 to the sectional area S2 of the groove 21 satisfies 0.3S 1/S2 is less than or equal to 0.7, the space occupied by the first protrusion 31 in the groove 21 is moderate, the contact area between the first protrusion 31 and the water in the flow channel 211 is moderate, which is beneficial to accelerating the absorption efficiency of the water, so that the water passing capacity in the flow channel 211 can be in a proper range while improving the water transmission capacity of the diffusion layer 3, and further the working efficiency of the electrolytic tank is ensured.

In a specific embodiment, as shown in fig. 4, along the first direction x, the height of the first protrusion 31 is H1, the depth of the groove 21 is H2, and the H1 and H2 satisfy: H1/H2 is more than or equal to 0.1 and less than or equal to 1.

In the embodiment of the present application, the ratio H1/H2 of the height H1 of the first protrusion 31 to the depth H2 of the groove 21 may be specifically 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, etc.

When the ratio of the height H1 of the first protrusion 31 to the depth H2 of the groove 21 is too small (e.g., H1/H2 is smaller than 0.1), the height of the first protrusion 31 protruding toward the inside of the groove 21 with respect to the body 34 is small in the first direction x, so that the contact area of the first protrusion 31 with the water in the flow path 211 is small, resulting in a low water absorption capacity of the first protrusion 31, and thus a low water transmission capacity of the diffusion layer 3.

When the ratio of the height H1 of the first protrusion 31 to the depth H2 of the groove 21 is 1, along the first direction x, the height of the first protrusion 31 facing the groove 21 relative to the body 34 is larger, so that the first protrusion 31 abuts against the bottom wall of the groove 21, and the first protrusion 31 and at least one side wall of the groove 21 can form at least one second flow channel 211b, so that water in the second flow channel 211b can flow along the first direction x towards the membrane electrode 1 through the first protrusion 31, and can also flow along the first direction x towards the membrane electrode 1 through the body 34 at the same time, thereby increasing the flow mode of water in the diffusion layer 3, accelerating the absorption efficiency of the diffusion layer 3 on water, and improving the water transmission capacity of the diffusion layer 3.

Therefore, when the ratio of the height H1 of the first protrusion 31 to the depth H2 of the groove 21 satisfies 0.1+.h1/h2+.1, the height of the first protrusion 31 facing the inside of the groove 21 along the first direction x relative to the body 34 is moderate, so that the water in the groove 21 can realize multiple diffusion modes through the first protrusion 31, so as to accelerate the absorption efficiency of the diffusion layer 3 to water, and facilitate the improvement of the water transmission capability of the diffusion layer 3.

In a specific embodiment, as shown in fig. 3 and 8, the first protrusion 31 includes a plurality of first metal particles 311, the first metal particles 311 have a diameter D1, and D1 satisfies: d1 is more than or equal to 70 mu m and less than or equal to 100 mu m.

In the embodiment of the present application, the diameter D1 of the first metal particles 311 may be specifically 70 μm, 73 μm, 75 μm, 77 μm, 80 μm, 83 μm, 85 μm, 87 μm, 90 μm, 93 μm, 95 μm, 97 μm, 100 μm, etc.

When the diameter of the first metal particles 311 is too small (e.g., D1 is less than 70 μm), the gaps in the first protrusions 31 are too small, the too small gaps are unfavorable for water penetration, and the fluidity of water is easily affected, resulting in a decrease in the water transporting ability of the first protrusions 31.

When the diameter of the first metal particles 311 is too large (e.g., D1 is greater than 100 μm), the gaps in the first protrusions 31 are too large, and the too large gaps may make the filtering performance of the first protrusions 31 poor, and external impurities easily permeate into the first protrusions 31 along with water and are transported into the diffusion layer 3 under the driving of water, thereby easily negatively affecting the inside of the electrolytic cell.

Therefore, when the diameter of the first metal particles 311 satisfies 70 μm and D1 and 100 μm, the gap in the first protrusion 31 is moderate, so that the first protrusion 31 can filter out impurities in water while improving the water transmission capacity, thereby ensuring the stability of the electrolytic cell in the working process.

In a specific embodiment, as shown in fig. 4, the cross-sectional shape of the first protrusion 31 along the first direction x is one or more of rectangular, circular, and trapezoidal.

In the embodiment of the present application, the cross-section shape of the first protrusion 31 along the first direction x may be rectangular, when the first protrusion 31 is located in the groove 21, the first protrusion 31, the bottom wall of the groove 21 and the side wall of the groove 21 may enclose the first flow channel 211a and the second flow channel 211b, so that water in the flow channel 211 can flow along the first direction x towards the membrane electrode 1 through the first protrusion 31, and also can flow along the first direction x towards the membrane electrode 1 through the first protrusion 31 after penetrating into the first protrusion 31 along the second direction y from both sides of the first protrusion 31, and can also flow along the first direction x directly into the body 34, so as to increase the diffusion mode of water from the groove 21 towards the membrane electrode 1, improve the water transmission capability of the diffusion layer 3, shorten the time of water transmission to the membrane electrode 1, thereby improving the gas generation efficiency in the electrolytic cell and improving the working efficiency of the electrolytic cell.

Or the cross section shape of the first protrusion 31 along the first direction x may be circular, when the first protrusion 31 is located in the groove 21, the first protrusion 31, the bottom wall of the groove 21 and the side wall of the groove 21 together enclose the first flow channel 211a, so that the contact area between the first protrusion 31 and water in the groove 21 is larger, which is beneficial to accelerating the absorption efficiency of the diffusion layer 3 on water, and thus the transmission performance of the diffusion layer 3 on water is improved.

Or the cross section shape of the first bulge 31 along the first direction x can be trapezoid, when the first bulge 31 is positioned in the groove 21, the first bulge 31 and the bottom wall of the groove 21 can enclose into a first flow channel 211a, so that water in the first flow channel 211a can be directly diffused towards the direction of the membrane electrode 1 along the first direction x through the first bulge 31, the possibility that the water moves in the diffusion layer 3 along the second direction y is reduced, the time for diffusing the water to the membrane electrode 1 is shortened, and the water transmission performance of the diffusion layer 3 is improved.

In a specific embodiment, as shown in fig. 3 and 4, the diffusion layer 3 further includes second protrusions 32 connected to the body 34, the second protrusions 32 are located at a side of the body 34 facing the membrane electrode 1 along the first direction x, and the plurality of second protrusions 32 can be spaced apart along the second direction y.

In the embodiment of the application, the second protrusions 32 are connected to one side of the body 34 facing the membrane electrode 1 along the first direction x, so that the diffusion layer 3 can abut against the membrane electrode 1 through the second protrusions 32, and the plurality of second protrusions 32 are distributed at intervals along the second direction y, so that a channel 35 is formed between two adjacent second protrusions 32.

Specifically, during operation of the electrolyzer, water flowing into the electrolyzer can flow in the direction of extension of the recess 21 and submerge the first protrusions 31 and the body 34 so that at least a portion of the water can flow in the channels 35 directly seeping out of the body 34.

Wherein, water in the groove 21 can flow in the flow channel 211 surrounded by the first protrusion 31 and the inner wall of the groove 21, at least part of water in each flow channel 211 can permeate into the first protrusion 31 and flow towards the body 34 along the first direction x through the gap between two adjacent first metal particles 311, when water flows into the body 34, water in the body 34 can permeate into the channel 35 between two adjacent second protrusions 32, and the channel 35 can promote water to flow to one side of the diffusion layer 3, which is abutted against the membrane electrode 1, to react and generate gas, thereby realizing the water transmission of the diffusion layer 3.

Meanwhile, flowing water in the channel 35 can drive gas to move along the extending direction of the groove 21, when the flow speed of water vapor in the channel 35 is high, the pressure in the channel 35 can be reduced, so that a pressure difference exists between the channel 35 and the second bulge 32, after the water reacts in the second bulge 32 to generate gas, the gas in the second bulge 32 can flow towards the channel 35 along the second direction y through the pressure difference between the two and can be collected in the channel 35, so that the water in the channel 35 can drive the gas to flow out of the diffusion layer 3 together, and further, the gas transmission of the diffusion layer 3 is realized.

Therefore, the diffusion layer 3 in the application not only can enlarge the contact area with water through the first protrusions 31 and improve the water absorption efficiency, but also can improve the mobility of water and gas in the diffusion layer 3 through the second protrusions 32 and the channels 35 between the two adjacent second protrusions 32, thereby improving the water vapor transmission capacity of the diffusion layer 3, further improving the overall working efficiency of the electrolytic tank and optimizing the working performance of the electrolytic tank.

In a specific embodiment, as shown in fig. 3, 4 and 8, the second protrusions 32 are metal particle layers, and the projection of the second protrusions 32 along the first direction x at least partially coincides with the projection of the grooves 21 along the first direction x.

In the embodiment of the present application, since the second protrusions 32 are metal particle layers, water can be diffused into the second protrusions 32, and water can be moved into the channels 35 along the second direction y through the gaps between two adjacent metal particles in the second protrusions 32, thereby further promoting water diffusion into the channels 35. Meanwhile, along the first direction x, the projection of the second protrusion 32 is at least partially overlapped with the projection of the groove 21, so that at least part of the second protrusion 32 is positioned above the groove 21, water in the first protrusion 31 can be diffused to the body 34 and the second protrusion 32 along the first direction x, and water in the second protrusion 32 can flow towards the membrane electrode 1 along the first direction x through gaps between two adjacent metal particles in the second protrusion 32, thereby shortening the path of water transmitted to the membrane electrode 1 along the first direction x and accelerating the transmission efficiency of the diffusion layer 3 to water. At the same time, the generated gas can also flow through the gap in the second direction y into the channel 35 so as to jointly flow out of the diffusion layer 3 under the drive of water, thereby realizing the capability of the diffusion layer 3 to transmit the gas.

And when the first protrusion 31 and the inner wall of the groove 21 enclose the flow channel 211 in the process that the diffusion layer 3 diffuses the water in the groove 21 to the membrane electrode 1. The water in the first flow channel 211a may permeate into the first protrusion 31 first, then flow along the first direction x toward the membrane electrode 1, and flow through the body 34 and the second protrusion 32 in sequence during the flowing process, so as to reduce the possibility of water flowing along the second direction y during the diffusion process, and facilitate improving the transmission efficiency of the diffusion layer 3 for transmitting the water to the side close to the membrane electrode 1. Meanwhile, the water in the second flow channel 211b may first permeate into the first protrusion 31 and then sequentially flow into the body 34 and the second protrusion 32 along the first direction x, or may directly permeate into the body 34 along the first direction x and then continuously flow into the second protrusion 32 along the first direction x, so as to further shorten the flowing distance of the water in the diffusion layer 3, and further increase the water transmission efficiency of the diffusion layer 3.

In a specific embodiment, as shown in fig. 3 and 5, the projection of the second protrusion 32 along the first direction x is located within the projection range of the groove 21 along the first direction x.

In the embodiment of the present application, along the first direction x, the projection of the second protrusion 32 is located within the projection range of the groove 21, so that the second protrusion 32 is completely located above the groove 21, which is favorable for further shortening the distance of water flowing in the body 34 along the second direction y, and further accelerating the transmission efficiency of the diffusion layer 3 to water.

The first protrusions 31 can enclose the flow passages 211 with the inner walls of the grooves 21 in the process that the diffusion layer 3 diffuses the water in the grooves 21 to the membrane electrode 1. The water in the first flow channel 211a may permeate into the first protrusion 31 first, then flow along the first direction x toward the membrane electrode 1, and flow through the body 34 and the second protrusion 32 in sequence during the flowing process, so as to reduce the possibility of water flowing along the second direction y during the diffusion process, and facilitate improving the transmission efficiency of the diffusion layer 3 for transmitting the water to the side close to the membrane electrode 1. Meanwhile, the water in the second flow channel 211b may first permeate into the first protrusion 31 and then sequentially flow into the body 34 and the second protrusion 32 along the first direction x, or may directly permeate into the body 34 along the first direction x and then continuously flow into the second protrusion 32 along the first direction x, so as to further shorten the flowing distance of the water in the diffusion layer 3, and further increase the water transmission efficiency of the diffusion layer 3.

In addition, when the second protrusions 32 are located entirely above the grooves 21 in the first direction x, the grooves 21 can correspond to one or more second protrusions 32 in the first direction x, and in this embodiment, one or more second protrusions 32 corresponding to each groove 21 are defined as a set of second protrusions 32.

Specifically, as shown in fig. 5, the grooves 21 are spaced apart along the second direction y, and when the second protrusions 32 are located completely above the grooves 21 along the first direction x, there is a gap between two adjacent groups of second protrusions 32, and the projection of the gap along the first direction x is located between two adjacent grooves 21.

Therefore, in the process that the diffusion layer 3 diffuses the water in the groove 21 to the membrane electrode 1, the water flowing into the body 34 can preferentially flow into the one or more second protrusions 32 corresponding to the groove 21, so that the possibility that the water in the groove 21 flows into the second protrusions 32 of the adjacent group in the diffusion process is reduced, the time for the water to diffuse from the groove 21 to the membrane electrode 1 is further shortened, and the water transmission capacity of the diffusion layer 3 is further improved.

Meanwhile, in the process of preparing the second protrusions 32, gaps are reserved between two adjacent groups of second protrusions 32, so that the input amount of preparation materials is reduced, the purpose of reducing the production cost can be achieved while the transmission performance of the diffusion layer 3 is improved, and the actual production requirements are met.

In another specific embodiment, as shown in fig. 6 and 7, the diffusion layer 3 further includes a third protrusion 33 connected to the body 34, the third protrusion 33 is located on a side of the body 34 facing the membrane electrode 1 along the first direction x, the third protrusion 33 is located between two adjacent second protrusions 32 along the second direction y, and a projection of the third protrusion 33 along the first direction x at least partially coincides with a projection of the first protrusion 31 along the first direction x. And in this embodiment the second projection 32 coincides with a part of the projection of the recess 21 in the first direction x or the projection of the second projection 32 does not coincide with the projection of the recess 21 in the first direction x.

In the embodiment of the application, the third protrusion 33 is connected with one side of the body 34 facing the membrane electrode 1 along the first direction x, and the third protrusion 33 is located between two adjacent second protrusions 32 along the second direction y, so that the diffusion layer 3 can be abutted with the membrane electrode 1 through the second protrusions 32 and the third protrusion 33.

Specifically, along the first direction x, the projection of the third protrusion 33 coincides with the projection of the first protrusion 31, so that at least part of the third protrusion 33 is located above the first protrusion 31, which is favorable for further shortening the distance of water flowing from the body 34 to the membrane electrode 1 along the first direction x in the process of diffusing the water in the groove 21 to the membrane electrode 1 by the diffusion layer 3, thereby accelerating the transmission efficiency of the diffusion layer 3 to the water.

In the process of diffusing the water in the groove 21 to the membrane electrode 1 by the diffusion layer 3, when the first protrusion 31 and the inner wall of the groove 21 enclose the flow path 211. The water in the first flow channel 211a may permeate into the first protrusion 31 first, then flow along the first direction x toward the membrane electrode 1, and continuously flow along the first direction x sequentially through the body 34 and the third protrusion 33 during the flowing process, so as to reduce the possibility of flowing along the second direction y during the diffusion process, and facilitate improving the transmission efficiency of the diffusion layer 3 for transmitting the water to the side close to the membrane electrode 1. Meanwhile, the water in the second flow channel 211b may first permeate into the first protrusion 31, then sequentially flow into the body 34 and the third protrusion 33 along the first direction x, and may also directly permeate into the body 34 along the first direction x and then continuously flow into the second protrusion 32 along the first direction x, so that the water in the flow channel 211 can flow to the membrane electrode 1 through the first protrusion 31, the second protrusion 32 and the third protrusion 33 corresponding to the groove 21, so as to further shorten the flowing distance of the water in the diffusion layer 3, and further accelerate the water transmission efficiency of the diffusion layer 3.

In a specific embodiment, as shown in fig. 6 and 7, there is a channel 35 between adjacent second protrusions 32 and third protrusions 33 along the second direction y.

In the embodiment of the present application, the third protrusion 33 is located between two adjacent second protrusions 32 along the second direction y, so that a channel 35 is formed between the adjacent third protrusion 33 and the second protrusion 32, where the third protrusion 33 and the second protrusion 32 may be disposed at intervals along the second direction y as shown in fig. 6, or may be disposed adjacent along the second direction y as shown in fig. 7.

When the third protrusion 33 and the second protrusion 32 are disposed at intervals along the second direction y (as shown in fig. 6), the projection of the third protrusion 33 along the first direction x at least partially coincides with the projection of the first protrusion 31 along the first direction x, and the projection of the second protrusion 32 along the first direction x may at least partially coincide with the projection of the groove 21 along the first direction x, or may be within the projection range of the groove 21 along the first direction x.

In a possible embodiment, when the projection of the second protrusion 32 along the first direction x at least partially coincides with the projection of the groove 21 along the first direction x (as shown in fig. 6), the first protrusion 31 and the inner wall of the groove 21 enclose the flow channel 211 during the diffusion of the water in the groove 21 to the membrane electrode 1 by the diffusion layer 3.

The water in the first flow channel 211a can permeate into the first protrusion 31 along the first direction x, then flow in the first protrusion 31 along the first direction x towards the direction close to the membrane electrode 1, meanwhile, the water in the second flow channel 211b can permeate into the first protrusion 31 along the second direction y, then flow in the first protrusion 31 along the first direction x towards the direction close to the membrane electrode 1, and can also permeate into the body 34 along the first direction x.

After the water in the groove 21 diffuses into the body 34, a part of the water in the groove 21 flows into the third protrusion 33 along the first direction x, then flows in the third protrusion 33 along the first direction x toward the membrane electrode 1, and reacts to generate gas in the process of approaching the membrane electrode 1, and another part of the water in the groove 21 flows into the second protrusion 32 adjacent to the third protrusion 33 along the first direction x and the second direction y, then flows in the second protrusion 32 along the first direction x toward the membrane electrode 1, and reacts to generate gas in the process of approaching the membrane electrode 1.

At least part of the water flowing into the electrolytic tank flows in the channel 35, so that the pressure in the channel 35 is low, and a pressure difference exists between the channel 35 and the third bulge 33 and between the channel 35 and the second bulge 32, so that the gas generated in the third bulge 33 and the second bulge 32 flows into the channel 35 along the second direction y, and flows out of the diffusion layer 3 together with the water which does not participate in the reaction under the driving of the water.

Therefore, in the present embodiment, along the first direction x, the projection of the third protrusion 33 at least partially coincides with the projection of the first protrusion 31, and the projection of the second protrusion 32 at least partially coincides with the projection of the groove 21, which is beneficial to improving the water transmission efficiency of the diffusion layer 3, thereby increasing the gas generation amount in the electrolytic cell and further improving the working efficiency of the electrolytic cell. Meanwhile, the third protrusions 33 and the second protrusions 32 are arranged at intervals along the second direction y, so that a plurality of channels 35 are formed in one side, facing the membrane electrode 1, of the diffusion layer 3, and the transmission capacity of the diffusion layer 3 to water vapor is improved, so that the stability and reliability of the electrolytic cell in the working process are guaranteed.

In another possible embodiment, when the projection of the second protrusion 32 along the first direction x is located within the projection range of the groove 21 along the first direction x, the first protrusion 31 and the inner wall of the groove 21 enclose the flow channel 211 during the diffusion process of the water in the groove 21 to the membrane electrode 1 by the diffusion layer 3.

After the water in the groove 21 diffuses into the body 34, a part of the water in the groove 21 flows into the third protrusion 33 along the first direction x, then flows in the third protrusion 33 along the first direction x toward the membrane electrode 1, and reacts to generate gas in the process of approaching the membrane electrode 1, and another part of the water in the groove 21 flows into the second protrusion 32 adjacent to the third protrusion 33 along the first direction x and the second direction y, and it is noted that the adjacent second protrusion 32 is the second protrusion 32 corresponding to the groove 21, then flows in the second protrusion 32 along the first direction x toward the membrane electrode 1, and reacts to generate gas in the process of approaching the membrane electrode 1.

Therefore, in the present embodiment, along the first direction x, the projection of the third protrusion 33 at least partially coincides with the projection of the first protrusion 31, and the projection of the second protrusion 32 is located within the projection range of the groove 21, which is favorable for further reducing the possibility that water flows along the second direction y in the diffusion process, and improving the possibility that water continuously flows along the first direction x in the diffusion process, thereby further improving the water transmission efficiency of the diffusion layer 3, increasing the gas generation amount in the electrolytic cell, and further improving the working efficiency of the electrolytic cell. Meanwhile, the third protrusions 33 and the second protrusions 32 are arranged at intervals along the second direction y, so that a plurality of channels 35 are formed in one side, facing the membrane electrode 1, of the diffusion layer 3, and the transmission capacity of the diffusion layer 3 to water vapor is improved, so that the stability and reliability of the electrolytic cell in the working process are guaranteed.

When the third protrusion 33 is disposed adjacent to the second protrusion 32 along the second direction y (as shown in fig. 7), the projection of the third protrusion 33 along the first direction x at least partially coincides with the projection of the first protrusion 31 along the first direction x, and the projection of the second protrusion 32 along the first direction x may at least partially coincide with the projection of the groove 21 along the first direction x, or may be within the projection range of the groove 21 along the first direction x.

In a possible embodiment, when the projection of the second protrusion 32 along the first direction x at least partially coincides with the projection of the groove 21 along the first direction x (as shown in fig. 7), the first protrusion 31 and the inner wall of the groove 21 enclose the flow channel 211 during the diffusion of the water in the groove 21 to the membrane electrode 1 by the diffusion layer 3.

Therefore, in the present embodiment, along the first direction x, the projection of the third protrusion 33 at least partially coincides with the projection of the first protrusion 31, and the projection of the second protrusion 32 at least partially coincides with the projection of the groove 21, which is beneficial to improving the water transmission efficiency of the diffusion layer 3, thereby increasing the gas generation amount in the electrolytic cell and further improving the working efficiency of the electrolytic cell. Meanwhile, the third protrusions 33 and the second protrusions 32 are adjacently arranged along the second direction y, so that water in the body 34 can flow along the second direction y to the third protrusions 33 and the second protrusions 32 corresponding to the adjacent grooves 21, uniformity of water distribution in the diffusion layer 3 is improved, reaction of water in the electrolytic cell is more uniform, and stability and reliability of the electrolytic cell in a working process can be improved.

Therefore, in the present embodiment, along the first direction x, the projection of the third protrusion 33 at least partially coincides with the projection of the first protrusion 31, and the projection of the second protrusion 32 is located within the projection range of the groove 21, which is favorable for further reducing the possibility that water flows along the second direction y in the diffusion process, and improving the possibility that water continuously flows along the first direction x in the diffusion process, thereby further improving the water transmission efficiency of the diffusion layer 3, increasing the gas generation amount in the electrolytic cell, and further improving the working efficiency of the electrolytic cell. Meanwhile, the third protrusion 33 and the second protrusion 32 are adjacent to each other along the second direction y, so that the third protrusion 33 and the second protrusion 32 corresponding to the groove 21 can generate a larger attractive force to the water in the body 34, thereby further guaranteeing the possibility that the water continuously flows along the first direction x in the diffusion process.

In one possible embodiment, as shown in fig. 7, in the two embodiments where the third protrusion 33 and the second protrusion 32 are disposed adjacent to each other along the second direction y, the cross-sectional shapes of the second protrusion 32 and the third protrusion 33 along the first direction x may be trapezoidal, which is beneficial to reducing the difficulty of preparation, and is convenient for processing and shaping, and the cross-sectional shape of the channel 35 may be V-shaped, so that the gas generated in the third protrusion 33 and the second protrusion 32 can be smoothly discharged out of the diffusion layer 3, and the gas transmission capability of the diffusion layer 3 is improved.

In one specific embodiment, the through-flow cross-sectional area of the channel 35 is S3, and S3 satisfies: 0.6mm ²≤S3≤25mm².

In the embodiment of the present application, the through-flow cross-sectional area S3 of the channel 35 may be 0.6mm²、0.8mm²、1mm²、3mm²、5mm²、7mm²、9mm²、11mm²、13mm²、15mm²、17mm²、19mm²、21mm²、23mm²、25mm².

When the through-flow cross-sectional area of the channel 35 is too small (e.g., S3 is smaller than 0.6mm ²), the gap between the second protrusion 32 and the third protrusion 33 is too small along the second direction y, so that the flow space of water and gas is smaller, the through-flow of water in the channel 35 is smaller, which is not beneficial to the discharge of gas, and the working efficiency of the electrolytic cell is reduced.

When the through-flow cross-sectional area of the channel 35 is too large (e.g., S3 is greater than 25mm ²), the gap between the second protrusion 32 and the third protrusion 33 is too large in the second direction y, so that the projection of the second protrusion 32 adjacent to the third protrusion 33 in the first direction x overlaps less with the projection of the groove 21 in the first direction x, resulting in a decrease in the speed at which water in the body 34 flows in the first direction x, and thus in a decrease in the water transmission capacity of the diffusion layer 3.

Therefore, when the through-flow cross-sectional area of the channel 35 meets 0.6mm ²≤S3≤25mm², the gap between the second protrusion 32 and the third protrusion 33 along the second direction y is moderate, so that the projection of the second protrusion 32 along the first direction x and the projection of the groove 21 along the first direction x overlap more, which is beneficial to improving the water transmission capacity of the diffusion layer 3, and meanwhile, the channel 35 has a larger through-flow space, so that the water and gas in the channel 35 can be smoothly discharged out of the diffusion layer 3, and the working efficiency of the electrolytic tank is improved.

In a specific embodiment, as shown in fig. 8, the first protrusion 31 includes a plurality of first metal particles 311, the second protrusion 32 includes a plurality of second metal particles 321, a first gap is provided between adjacent first metal particles 311, and a second gap is provided between adjacent second metal particles 321, and the first gap is greater than the second gap.

In the embodiment of the application, the first gaps in the first protrusions 31 and the second gaps in the second protrusions 32 can ensure the smoothness of water and gas flowing in the diffusion layer 3, and reduce the possibility of weaker water-gas transmission capability of the diffusion layer 3. Specifically, the first gaps in the first protrusions 31 are larger than the second gaps in the second protrusions 32, so that the pores of the diffusion layer 3 gradually decrease in the direction along the first direction x toward the membrane electrode 1, and the diffusion layer 3 can improve the diffusion efficiency of water into the diffusion layer 3 through capillary phenomenon, thereby being beneficial to enhancing the absorption efficiency of the diffusion layer 3 to electrolyte. Wherein, the first metal particles 311 and the second metal particles 321 can be spherical, when a plurality of metal particles are connected together, compared with metal particles with other shapes, the phenomenon that gaps disappear due to close fit between adjacent metal particles can be avoided, mobility of water and gas in the first protrusions 31 and the second protrusions 32 is ensured, and risks of too low capability of the diffusion layer 3 in transmitting water vapor due to the disappearance of gaps are reduced. Meanwhile, along the first direction x, as the second protrusion 32 is connected to one side of the body 34 facing the membrane electrode 1, in the process that the diffusion layer 3 is connected with the membrane electrode 1, the diffusion layer 3 is abutted with the membrane electrode 1 through the second protrusion 32, so that the diffusion layer 3 can refine the surface pores of the body 34 and the membrane electrode 1 through the second metal particles 321, thereby being beneficial to reducing the contact resistance between the diffusion layer 3 and the membrane electrode 1 and improving the working stability of the electrolytic tank.

In a specific embodiment, as shown in fig. 8, the body 34 has a third gap, which is larger than the second gap, the first gap is larger than the third gap, and the third gap gradually decreases in the direction of the electrode plate 2 toward the membrane electrode 1.

In the embodiment of the application, the first gap of the first protrusion 31 is larger than the third gap of the body 34, and the third gap of the body 34 is larger than the second gap of the second protrusion 32, so that the diffusion layer 3 further forms a gradient structure on the whole structure, and water in the groove 21 can diffuse towards the direction of the membrane electrode 1 along the first direction x under the action of capillary phenomenon, thereby accelerating the generation of gas at the membrane electrode 1 and improving the working efficiency of the electrolytic tank. The third gap of the body 34 gradually decreases along the direction of the first direction x towards the membrane electrode 1, so as to further refine the gradient structure in the body 34, thereby being beneficial to further promoting the capillary phenomenon, improving the efficiency of water transmission in the diffusion layer 3, and further improving the efficiency of water transmission by the diffusion layer 3.

In one possible embodiment, the third protrusion 33 includes a plurality of third metal particles, and the adjacent third metal particles have a fourth gap therebetween, the first gap is greater than the fourth gap, the third gap is greater than the fourth gap, and the second gap may be equal to or smaller than the fourth gap.

In the embodiment of the present application, when the third protrusion 33 is located above the first protrusion 31 along the first direction x and the third protrusion 33 is located between two adjacent second protrusions 32 along the second direction y, the first gap of the first protrusion 31, the third gap of the body 34, and the fourth gap of the third protrusion 33 can form a gradient structure in the first direction x of the diffusion layer 3, which is beneficial to accelerating the flow speed of water in the diffusion layer 3 along the first direction x. In the case that the third gap of the third protrusion 33 is equal to the second gap of the adjacent second protrusion 32, the water in the body 34 is more easily transferred to the side of the diffusion layer 3, which is close to the membrane electrode 1, so that the transmission efficiency of the diffusion layer 3 to the water is further improved, and the working efficiency of the electrolytic tank is improved. Or in the case where the third gap of the third protrusion 33 is smaller than the second gap of the adjacent second protrusion 32, the possibility of water flowing in the second direction y within the body 34 can be reduced by taking advantage of the gradient structure, so that the time for water to diffuse from within the groove 21 to the membrane electrode 1 side can be shortened to further optimize the water transmission capability of the diffusion layer 3. Wherein, the plurality of third metal particles of the third protrusion 33 may also have a spherical structure.

In a specific embodiment, the first protrusions 31 and the second protrusions 32 are formed on the body 34 by screen printing.

In the embodiment of the application, the screen printing has the characteristic of easy configuration, and the mode of the screen printing is not limited by the size and shape of a printing stock, which is beneficial to reducing the difficulty of preparing the first bulge 31 and the second bulge 32 on the body 34, thereby improving the preparation efficiency of the first bulge 31 and the second bulge 32 and further improving the processing efficiency of the diffusion layer 3. Meanwhile, the silk screen in silk screen printing is soft and elastic, damage to the body 34 in the printing process can be reduced, so that the production yield of the diffusion layer 3 is improved, in addition, the cost of silk screen printing is low, the silk screen printing is easy to control, and the practical use requirements are met.

In a possible embodiment, when the diffusion layer 3 further includes the third protrusion 33, since the third protrusion 33 and the second protrusion 32 are both connected to the side of the body 34 facing the membrane electrode 1 along the first direction x, the third protrusion 33 and the second protrusion 32 can be formed on the body 34 by screen printing at the same time, so as to save processing steps and improve production efficiency.

Specifically, in the process of preparing the first protrusion 31, first metal particles 311 and slurry are mixed to form a first mixture, the first mixture is printed on one side of the body 34 through a printing screen, so that the first mixture is attached to the surface of the body 34, and then moisture in the first mixture is removed through a drying manner, at this time, the first metal particles 311 in the first mixture are bonded together through glue, and the volume of the glue is 30% -40% of the volume of the first mixture.

When the diffusion layer 3 further includes the second protrusions 32, it may be prepared after the preparation of the first protrusions 31 is completed. Specifically, the second metal particles 321 and the slurry are mixed to form a second mixture, the second mixture is printed on one side of the body 34, which is away from the first protrusions 31, through a printing screen, so that the second mixture is attached to the surface of the body 34, and then the moisture in the second mixture is removed through a drying mode, at this time, the second metal particles 321 in the second mixture are bonded together through glue, and the volume ratio of the glue in the second mixture can be 40% -50%.

When the diffusion layer 3 further includes the third protrusions 33, it may be prepared simultaneously with the second protrusions 32 after the preparation of the first protrusions 31 is completed, or it may be prepared separately after the preparation of the second protrusions 32 is completed. Specifically, the third metal particles and the slurry are mixed to form a third mixture, and then the third mixture is printed on one side of the body 34, which is away from the first protrusions 31, through the printing screen and the second mixture, or is printed between two adjacent second protrusions 32 through the printing screen, so that the third mixture is attached to the surface of the body 34, and then the moisture in the third mixture is removed through a drying mode, at this time, a plurality of third metal particles in the third mixture are bonded together through glue, and the volume ratio of the glue in the second mixture can be 40% -50% or 50% -60%.

Wherein, after each metal particle mixes with the thick liquids and forms the mixture, can take out the bubble in the mixture through the defoaming machine to reduce the possibility that each protruding inside produced the gas pocket in the course of working, improve each protruding structural stability, thereby improve the holistic mechanical strength of diffusion layer 3.

Specifically, in the process of defoaming each mixture, the rotating speed of the first section of the defoaming machine can be 600r/min-800r/min, the time can be 30s-50s, the vacuum degree can be 0.5Kpa-0.8Kpa, the rotating speed of the second section of the defoaming machine can be 2100r/min-2500r/min, the time can be 150s-180s, the vacuum degree can be 1Kpa-1.2Kpa, the rotating speed of the third section of the defoaming machine can be 1100r/min-1500r/min, the time can be 50s-80s, and the vacuum degree can be 1Kpa-1.2Kpa.

Finally, the glue in the first mixture, the second mixture or the third mixture is removed by high-temperature sintering, so that the first metal particles 311 are in solid phase connection, the second metal particles 321 are in solid phase connection, the third metal particles are in solid phase connection, the first protrusions 31 are in solid phase connection with the body 34, the second protrusions 32 are in solid phase connection with the body 34, and the third protrusions 33 are in solid phase connection with the body 34, and the preparation of the metal particle layer on the metal felt layer is completed.

Therefore, through screen printing's preparation method, can be more convenient and fast with metal particle attached to the surface on metal felt layer, and the metal particle after the adhesion can demonstrate the structure of predetermineeing to have higher structural stability, reduced the degree of difficulty when configuring metal particle effectively, be convenient for follow-up mode through the sintering formation metal particle layer more.

In one possible embodiment, the electrolytic cell provided by the application comprises a membrane electrode 1, a polar plate 2 and a diffusion layer 3, wherein the diffusion layer 3 is positioned between the membrane electrode 1 and the polar plate 2 along a first direction x, and the diffusion layer 3 comprises a body 34 and first bulges 31 connected with the body 34, and the first bulges 31 are positioned on one side of the body 34 facing the polar plate 2 and are distributed at intervals along a second direction y.

Wherein the first protrusions 31 are metal particle layers, the body 34 is a metal felt layer, and the surface of the electrode plate 2 facing the diffusion layer 3 along the first direction x may be a plane. In the process of assembling the electrode plate 2 and the diffusion layer 3, the first protrusions 31 are abutted against the electrode plate 2, so that the side walls of two adjacent first protrusions 31, the body 34 and the electrode plate 2 jointly enclose a third flow passage 211c. During operation of the electrolyzer, water flowing into the electrolyzer can flow in the third flow channel 211c.

In the embodiment of the present application, when the plate 2 and the diffusion layer 3 together enclose the third flow channel 211c, water in the third flow channel 211c can flow in the direction of the membrane electrode 1 along the first direction x through the top wall and at least one side wall of the third flow channel 211 c. Specifically, a part of water in the third flow channel 211c can be directly diffused into the body 34 along the first direction x, and at the same time, another part of water in the third flow channel 211c can be firstly permeated into the first protrusion 31 from at least one side of the third flow channel 211c along the second direction y, and then diffused towards the membrane electrode 1 along the first direction x through the first protrusion 31, so as to realize the transmission of water by the diffusion layer 3.

Therefore, the diffusion layer 3 in this embodiment can further enlarge the contact area with water through the first protrusion 31, so that water in the third flow channel 211c can flow towards the membrane electrode 1 along the first direction x through the first protrusion 31 and the body 34 at the same time, which is beneficial to further accelerating the absorption efficiency of the diffusion layer 3 on water, improving the transmission efficiency of the diffusion layer 3 on water, and increasing the generation amount of gas in the electrolytic cell.

Meanwhile, the side walls of two adjacent first bulges 31, the body 34 and the polar plate 2 jointly enclose a third flow passage 211c, so that the polar plate 2 in the embodiment does not need to be processed with the groove 21, which is beneficial to reducing the processing steps of the polar plate 2 and improving the production efficiency of the polar plate 2; and when the first protrusions 31 are metal particle layers, the first protrusions 31 include a plurality of metal particles with gaps between adjacent two of the metal particles, and during operation of the electrolytic cell, water in each third flow passage 211c can flow not only in the direction of the membrane electrode 1 in the first direction x through the gaps, but also in the adjacent third flow passages 211c in the second direction y through the gaps.

Therefore, the diffusion layer 3 in the embodiment can also make the water flowing into the electrolytic cell more uniform, thereby guaranteeing the uniformity of the reaction in the electrolytic cell and being beneficial to improving the stability and reliability of the electrolytic cell in the working process.

In one possible embodiment, the cross-sectional shape of the first protrusion 31 may be rectangular or trapezoidal along the first direction x, so that the diffusion layer 3 and the electrode plate 2 are in plane-to-plane contact, which is beneficial to improve stability and reliability when the two are connected, thereby improving structural stability of the third flow channel 211 c. Meanwhile, along the first direction x, the connection part of the first protrusion 31 and the body 34 is in an arc structure, so that the cross section of the third flow channel 211c is semicircular or arched, which is beneficial to reducing the stress at the connection part of the first protrusion 31 and the body 34, thereby reducing the possibility of collapse of the third flow channel 211c in the working process of the electrolytic bath and further improving the structural stability of the third flow channel 211 c.

In a possible embodiment, when the diffusion layer 3 encloses the third flow channel 211c together with the body 34 and the electrode plate 2 by the side walls of two adjacent first protrusions 31, the side of the diffusion layer 3 facing the membrane electrode 1 along the first direction x may also be provided with the above-mentioned second protrusions 32 and/or third protrusions 33, so as to further improve the operation performance of the electrolytic cell.

While the foregoing is directed to embodiments of the present application, other and further embodiments of the application may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. An electrolytic cell, the cell comprising:

a membrane electrode (1);

a pole plate (2), the pole plate (2) having a recess (21);

A diffusion layer (3), along a first direction x, the diffusion layer (3) being located between the membrane electrode (1) and the plate (2), the diffusion layer (3) comprising a body (34) and a first protrusion (31) connected to the body (34), the first protrusion (31) being located on a side of the body (34) facing the plate (2);

The first protrusions (31) are metal particle layers, the first protrusions (31) are located in the grooves (21), and flow passages (211) are formed between the first protrusions (31) and the inner walls of the grooves (21);

The flow channel (211) at least comprises a first flow channel (211 a), and along a first direction x, at least the first protrusion (31) and the bottom wall of the groove (21) enclose the first flow channel (211 a).

2. The cell of claim 1, wherein the flow channel (211) further comprises a second flow channel (211 b), the first protrusion (31) and at least one side wall of the recess (21) enclosing at least one of the second flow channels (211 b) in the second direction y.

3. The cell of claim 1, wherein the cross-sectional area of the first protrusion (31) is S1, the cross-sectional area of the recess (21) is S2, and S1 and S2 satisfy: S1/S2 is more than or equal to 0.3 and less than or equal to 0.7.

4. The cell according to claim 1, characterized in that in the first direction x the height of the first protrusion (31) is H1, the depth of the groove (21) is H2, and H1 and H2 satisfy: H1/H2 is more than or equal to 0.1 and less than or equal to 1.

5. The cell according to claim 1, characterized in that the first protrusion (31) abuts at least one side wall of the recess (21) in the second direction y.

6. The electrolyzer of claim 1 characterized in that the first protrusions (31) comprise a plurality of first metal particles (311), the first metal particles (311) having a diameter D1, and D1 satisfying: d1 is more than or equal to 70 mu m and less than or equal to 100 mu m.

7. The cell according to claim 1, wherein the first protrusion (31) has one or more of a rectangular, circular and trapezoidal cross-sectional shape along the first direction x.

8. The cell according to any one of claims 1-7, wherein the diffusion layer (3) further comprises a second protrusion (32) connected to the body (34), the second protrusion (32) being located on a side of the body (34) facing the membrane electrode (1) in a first direction x;

the second protrusions (32) are spaced apart along the second direction y.

9. An electrolytic cell according to claim 8, characterised in that the second protrusions (32) are layers of metal particles, the projection of the second protrusions (32) in the first direction x at least partially coinciding with the projection of the grooves (21) in the first direction x.

10. An electrolytic cell according to claim 8, characterised in that the projection of the second protrusion (32) in the first direction x lies within the projection of the recess (21) in the first direction x.

11. The cell according to claim 8, characterized in that the diffusion layer (3) further comprises a third protrusion (33) connected to the body (34), the third protrusion (33) being located on a side of the body (34) facing the membrane electrode (1) in a first direction x, the third protrusion (33) being located between two adjacent second protrusions (32) in a second direction y, and the projection of the third protrusion (33) in the first direction x at least partially coincides with the projection of the first protrusion (31) in the first direction x.

12. An electrolytic cell according to claim 11, characterised in that in the second direction y there is a channel (35) between the adjacent second (32) and third (33) projections.

13. The cell according to claim 12, characterized in that the through-flow cross-sectional area of the channel (35) is S3, and S3 satisfies: 0.6mm ²≤S3≤25mm².

14. The electrolytic cell of claim 8 wherein the first protrusion (31) comprises a plurality of first metal particles (311) and the second protrusion (32) comprises a plurality of second metal particles (321), wherein a first gap is provided between adjacent first metal particles (311) and a second gap is provided between adjacent second metal particles (321), and wherein the first gap is greater than the second gap.

15. The electrolyzer of claim 14 characterized in that the body (34) has a third gap, the third gap being greater than the second gap, the first gap being greater than the third gap;

The third gap gradually decreases along the direction of the polar plate (2) towards the membrane electrode (1).

16. The cell according to claim 8, characterized in that the first (31) and the second (32) projections are formed on the body (34) by means of screen printing.