Gas diffusion layer for electrolytic cell and electrolytic cell

Abstract

The utility model provides a gas diffusion layer for an electrolytic bath and the electrolytic bath, and relates to the technical field of electrolysis. The gas diffusion layer for an electrolytic cell includes: a support layer; a plurality of first holes are formed in the supporting layer; the at least one microporous layer is laminated on one side of the supporting layer; a plurality of second holes are formed in the microporous layer, the hole diameter of the second holes is smaller than that of the first holes, and the hole diameter of the second holes ranges from 0.05 micrometer to 30 micrometers. According to the utility model, the aperture of the second hole in the micropore layer in the gas diffusion layer is smaller, the second hole plays a role in aperture transition between the supporting layer and the catalyst layer, the aperture difference between every two of the catalyst layer, the micropore layer and the supporting layer is smaller, after gas is generated, the gas can be desorbed from the surface of the catalyst layer more quickly, and the gas diffusion effect is better. Therefore, gas accumulation is reduced, and gas can be discharged quickly. And the aperture of the second hole is not too small, so that the rapid discharge of gas is guaranteed, and the electrolysis efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electrolysis, in particular to a gas diffusion layer for an electrolytic cell and an electrolytic cell. Background Art

[0002] Hydrogen plays an important role in the carbon neutralization path due to its advantages of being clean and pollution-free, having a high energy density, and being storable and transportable. Electrolytic water hydrogen production is currently the simplest and most effective way to obtain high-purity hydrogen, which can be combined with renewable energy power generation technologies, such as photovoltaic power generation, hydropower, and wind power, to produce green hydrogen and achieve zero carbon emissions during the hydrogen production process. For example, electrolytic water can be used as a large-scale hydrogen production technology, which has advantages such as environmental friendliness and high economic benefits and has good application prospects. During the electrolytic hydrogen production process, a large amount of gas is continuously generated, and it is necessary to quickly transport the generated gas outside the electrolytic cell, which is beneficial to releasing more active sites for electrolytic reactions and accelerating the mass transfer process.

[0003] Currently, the electrolytic cell mainly consists of a gas diffusion layer adjacent to the catalytic layer, which transports the gas generated by the reaction outside the electrolytic cell.

[0004] However, the existing gas diffusion layer will cause the gas generated by the reaction to accumulate in the catalytic layer and the gas diffusion layer, resulting in blocked gas discharge, which is not conducive to the progress of the electrolytic reaction and thus affects the performance of the electrolytic cell. Summary of the Utility Model

[0005] The utility model provides a gas diffusion layer for an electrolytic cell and an electrolytic cell, aiming to solve the problem that the existing gas diffusion layer for an electrolytic cell causes gas to accumulate in the catalytic layer and the gas diffusion layer.

[0006] In the first aspect of the utility model, a gas diffusion layer for an electrolytic cell is provided, including:

[0007] A support layer; the support layer has a number of first holes;

[0008] At least one microporous layer, laminated on one side of the support layer;

[0009] Wherein, the microporous layer has a number of second holes, the aperture of the second hole is smaller than the aperture of the first hole, and the aperture of the second hole is 0.05 μm to 30 μm.

[0010] In the present utility model, the pore diameter of the second pores in the microporous layer of the gas diffusion layer is relatively small, which plays a role in pore diameter transition between the support layer and the catalytic layer. Among the catalytic layer, the microporous layer, and the support layer, the pore diameter difference between adjacent two layers is relatively small. After the gas is generated in the catalytic layer, it basically does not need to grow and can be desorbed from the surface of the catalytic layer relatively quickly, thereby reducing gas accumulation and enabling the gas to be discharged rapidly. At the same time, the pore diameter of the second pores in the microporous layer is 0.05 μm to 30 μm, and the pore diameter is not too small, ensuring the rapid discharge of gas and improving the electrolysis efficiency.

[0011] Optionally, the number of layers of the microporous layer is greater than or equal to 2, and along the direction away from the support layer, the pore diameter of the second pores in each layer of the microporous layer decreases.

[0012] Optionally, both the microporous layer and the support layer include particles; the particle size of the particles in the microporous layer is smaller than the particle size of the particles in the support layer; the number of layers of the microporous layer is greater than or equal to 2, and along the direction away from the support layer, the particle size of the particles in each layer of the microporous layer decreases.

[0013] Optionally, the microporous layer includes: metal particles, the number of layers of the microporous layer is greater than or equal to 2, and along the direction away from the support layer, the mass ratio of the metal particles in each layer of the microporous layer decreases.

[0014] Optionally, the mass ratio of the metal particles in the microporous layer is 70% to 98%; and / or, the particle size of the particles in the microporous layer is 0.1 μm to 10 μm.

[0015] Optionally, each layer of the microporous layer includes: at least one first microporous layer containing a hydrophobic binder.

[0016] Optionally, the number of layers of the first microporous layer is greater than or equal to 2, and along the direction away from the support layer, the contact angle of the surface of each layer of the first microporous layer increases.

[0017] Optionally, each layer of the microporous layer includes: at least one second microporous layer containing an ion exchange membrane type binder; each layer of the second microporous layer is farther from the support layer than all the first microporous layers; the ion exchange membrane type binder includes: an anion exchange membrane type binder, or a cation exchange membrane type binder.

[0018] Optionally, each layer of the microporous layer includes: at least one second microporous layer containing an ion exchange membrane type binder; the ion exchange membrane type binder includes: an anion exchange membrane type binder, or a cation exchange membrane type binder.

[0019] Optionally, the number of layers of the second microporous layer is greater than or equal to 2, and along the direction away from the support layer, the contact angle of the surface of each layer of the second microporous layer decreases.

[0020] Optionally, the porosity of the microporous layer is less than the porosity of the support layer; the number of layers of the microporous layer is greater than or equal to 2, and along the direction away from the support layer, the porosity of each layer of the microporous layer

[0021] decreases.

[0022] Optionally, the porosity of the microporous layer is 20% to 60%.

[0023] Optionally, the support layer is at least one of: a metal felt layer, a metal foam layer, and a sintered metal particle layer;

[0024] and / or, the microporous layer includes at least one of: titanium particles and titanium oxide particles, nickel particles and nickel oxide particles, and stainless steel particles and stainless steel oxide particles;

[0025] and / or, the contact angle of the surface of the microporous layer is less than or equal to 50°.

[0026] In a second aspect of the present invention, there is provided an electrolytic cell, comprising: a catalytic layer and any one of the aforementioned gas diffusion layers for an electrolytic cell;

[0027] The microporous layer is located between the support layer and the catalytic layer.

[0028] Optionally, each layer of the microporous layer includes: at least one second microporous layer containing an ion exchange membrane type binder;

[0029] In the case where the electrolytic cell is an AEM electrolytic cell, the ion exchange membrane type binder is an anion exchange membrane type binder;

[0030] In the case where the electrolytic cell is a PEM electrolytic cell, the ion exchange membrane type binder is a cation exchange membrane type binder.

[0031] The aforementioned gas diffusion layer for an electrolytic cell and the electrolytic cell have the same or similar beneficial effects. To avoid repetition, they will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0033] Figure 1 Shows a schematic structural diagram of a gas diffusion layer for an electrolytic cell in an embodiment of the present invention;

[0034] Figure 2 Shows a schematic structural diagram of another gas diffusion layer for an electrolytic cell in an embodiment of the present invention;

[0035] Figure 3 Shows a schematic structural diagram of yet another gas diffusion layer for an electrolytic cell in an embodiment of the present invention.

[0036] Description of the drawing reference numerals:

[0037] 100 - Gas diffusion layer, 1 - Support layer, 2 - Microporous layer. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0039] The existing gas diffusion layer will cause the gas generated by the reaction to accumulate in the catalytic layer and the gas diffusion layer, and the main reason for the blocked gas discharge is that: the existing gas diffusion layer usually uses materials such as metal foam or metal felt (such as titanium felt, sintered titanium metal, nickel felt, nickel foam, etc.), and this type of structure is usually a homogeneous structure with relatively large pore diameters (the minimum pore diameter is usually greater than 5 μm (micrometers), and the average pore diameter is usually greater than 10 μm). The pore diameter of the catalytic layer is much smaller than that of the existing gas diffusion layer. Compared with the catalytic layer, there is a large pore diameter difference between the two. After the gas is generated in the catalytic layer, it needs to grow to be approximately the same as the pore diameter of the adjacent gas diffusion layer before it can desorb from the surface of the catalytic layer, resulting in the accumulation of the generated gas between the catalytic layer and the gas transport layer and blocking the gas discharge.

[0040] Figure 1 Shows a schematic structural diagram of a gas diffusion layer for an electrolytic cell in an embodiment of the present invention. Figure 2 Shows a schematic structural diagram of another gas diffusion layer for an electrolytic cell in an embodiment of the present invention. Figure 3 Shows a schematic structural diagram of yet another gas diffusion layer for an electrolytic cell in an embodiment of the present invention.

[0041] The present invention provides a gas diffusion layer 100 for an electrolytic cell, referring to Figures 1 to 3, the gas diffusion layer 100 for the electrolytic cell may include: a support layer 1 having a plurality of first holes (not shown in the figure). The first holes may be through holes, and the extending direction of the holes may be substantially along the lamination direction of the support layer 1 and the microporous layer 2. The number of the first holes in the support layer 1 is not specifically limited. The gas diffusion layer 100 may further include at least one microporous layer 2 laminated on one side of the support layer 1. The number of the microporous layers 2 in the gas diffusion layer 100 is not specifically limited. For example, Figure 1 in the gas diffusion layer 100, there is 1 microporous layer 2, Figure 2 in the gas diffusion layer 100, there are 2 microporous layers 2, Figure 3 in the gas diffusion layer 100, there are 3 microporous layers 2.

[0042] Among them, the microporous layer 2 has a plurality of second holes (not shown in the figure), and the number of the second holes in the microporous layer 2 is not specifically limited. The second holes may be through holes, and the extending direction of the holes may be substantially along the lamination direction of the support layer 1 and the microporous layer 2. The aperture of the second holes is smaller than that of the first holes, and the aperture of the second holes is 0.05 μm to 30 μm.

[0043] Aiming at the above technical problems, in the present utility model, the aperture of the second holes in the microporous layer 2 in the gas diffusion layer 100 is small, which plays a role in aperture transition between the support layer 1 and the catalytic layer. Among the catalytic layer, the microporous layer 2 and the support layer 1, the aperture gap between adjacent two of them is small. After the gas is generated in the catalytic layer, it basically does not need to grow and can be desorbed from the surface of the catalytic layer quickly, thereby reducing gas accumulation and enabling the gas to be discharged quickly. At the same time, the aperture of the second holes in the microporous layer 2 is 0.05 μm to 30 μm, and the aperture is not too small, ensuring the rapid discharge of the gas and improving the electrolysis efficiency. There is no need to add a pore-forming agent in the gas diffusion layer 100 of the present application, and it will not be affected by the cracks that may be introduced by the pore-forming agent.

[0044] For example, the aperture of the second holes in the microporous layer 2 may be 0.05 μm, or 0.09 μm, or 0.13 μm, or 0.7 μm, or 0.9 μm, or 2.3 μm, or 4.4 μm, or 10 μm, or 13.45 μm, or 15 μm, or 18 μm, or 22.1 μm, or 27.4 μm, or 30 μm.

[0045] It should be noted that the pore diameter mentioned throughout the text refers to: on the cross-section perpendicular to the extension direction of the pore, the maximum size of the pore. For example, in the case where the second pore is a cylindrical through-hole, the pore diameter of the second pore refers to the diameter of the second pore. The microporous layer 2 is a homogeneous structure, that is, the structures, properties, etc. at various positions in the microporous layer 2 are the same or similar. The support layer 1 is also a homogeneous structure, that is, the structures, properties, etc. at various positions in the support layer 1 are the same or similar.

[0046] Optionally, the variance of the contact angles of the respective surfaces of the microporous layer 2 is less than or equal to (1°) 2 , which means that the contact angles of the respective surfaces of the microporous layer 2 are approximately equal. For example, the variance of the contact angles of the respective surfaces of the microporous layer 2 can be (0.01°) 2 , or (0.08°) 2 , or (0.1°) 2 , or (0.13°) 2 , or (0.26°) 2 , or (0.49°) 2 , or (0.67°) 2 , or (0.83°) 2 , or (1°) 2 .

[0047] Optionally, each microporous layer 2 includes: at least one first microporous layer containing a hydrophobic binder. Here, one first microporous layer is one of the microporous layers 2 in the gas diffusion layer 100. There is no specific limitation on the number of layers of the first microporous layer. Here, the hydrophobic binder refers to a binder that can bond metal particles and has hydrophobicity. For example, the hydrophobic binder here can be a PTFE (polytetrafluoroethylene) binder, a PVDF (polyvinylidene fluoride) binder, etc. There is no specific limitation on the specific material or composition of the hydrophobic binder. That is to say, the first microporous layer has a certain hydrophobicity, providing a good hydrophobic transport channel for gas discharge, which is conducive to gas discharge. Moreover, since the pore diameter of the second pore in each first microporous layer is 0.05 μm to 30 μm, the pore diameter is of a more appropriate size, and a liquid transport channel can be established through capillary action, promoting liquid transport. Therefore, this utility model not only facilitates the rapid discharge of gas, but also facilitates liquid transport, achieving a balance between gas transport and liquid transport, and further improving the electrolysis efficiency.

[0048] Figures 1 to 3Among them, the direction indicated by the virtual arrow L is the direction away from the support layer 1. The larger the contact angle of the surface of the microporous layer 2, the stronger the hydrophobicity and the worse the hydrophilicity. The number of layers of the first microporous layer is greater than or equal to 2. Along the direction L away from the support layer, the contact angle of the surface of each layer of the first microporous layer increases. That is to say, the number of layers of the first microporous layer is greater than or equal to 2. Along the direction away from the support layer 1, the hydrophobicity of each layer of the first microporous layer increases. The direction away from the support layer 1 is the direction closest to the catalytic layer. That is, the closer to the catalytic layer, the hydrophobicity of each layer of the first microporous layer increases, providing a good gradient hydrophobic transport channel for gas discharge, facilitating gas discharge. Moreover, since the pore diameter of the second pores in each layer of the first microporous layer is 0.05 μm to 30 μm, the pore size is more appropriate, and a liquid transport channel can be established through capillary action, promoting liquid transport. Therefore, this utility model not only facilitates the rapid discharge of gas, but also facilitates liquid transport, achieving the balance of gas transport and liquid transport, and further improving the electrolysis efficiency.

[0049] It should be noted that in the electrolytic cell, the gas transport direction is usually from the catalytic layer to the support layer 1, and the liquid transport direction can be opposite to the gas transport direction. The number of layers of the first microporous layer in all the microporous layers 2 or in the gas diffusion layer 100 is not specifically limited.

[0050] Optionally, along the direction L away from the support layer, the contact angle of the surface of each layer of the first microporous layer increases linearly. That is to say, along the direction L away from the support layer, the difference in the contact angle of the surface between every two adjacent first microporous layers is equal. Along the direction close to the catalytic layer, the hydrophobicity of each layer of the first microporous layer increases linearly, providing a better gradient hydrophobic transport channel for gas discharge, being more conducive to gas discharge, and further improving the electrolysis efficiency.

[0051] Optionally, on the basis that each layer of the microporous layer 2 includes the first microporous layer, each layer of the microporous layer 2 may further include: at least one second microporous layer containing an ion exchange membrane type binder. Each layer of the second microporous layer is farther from the support layer 1 than all the first microporous layers. One layer of the second microporous layer here is a certain layer of the microporous layer 2 in the gas diffusion layer 100. The number of layers of the second microporous layer in all the microporous layers 2 or in the gas diffusion layer 100 is not specifically limited. Specifically, the ion exchange membrane type binder can be an anion exchange membrane type binder or a cation exchange membrane type binder. Each layer of the second microporous layer is farther from the support layer 1 than all the first microporous layers, that is, each layer of the second microporous layer and the catalytic layer are adjacent to each other. The second microporous layer containing the ion exchange membrane type binder has a good promoting effect on ion transport, and thus can promote more ions to be transported to the catalytic layer to participate in the electrolysis reaction, and further improve the electrolysis efficiency.

[0052] It should be noted that for the ion exchange membrane-based binder here, specifically whether to select an anion exchange membrane-based binder or a cation exchange membrane-based binder needs to be determined according to the specific type of the electrolytic cell. Optionally, when the electrolytic cell is an AEM (Anion exchange membrane) electrolytic cell, the ion exchange membrane-based binder in the second microporous layer is an anion exchange membrane-based binder, which promotes the transport of, for example, OH - and improves the electrolysis efficiency. When the electrolytic cell is a PEM (Proton exchange membrane) electrolytic cell, the ion exchange membrane-based binder in the second microporous layer is a cation exchange membrane-based binder, which promotes the transport of, for example, H - and improves the electrolysis efficiency.

[0053] Optionally, each microporous layer 2 includes: a second microporous layer containing an ion exchange membrane-based binder. One second microporous layer is a certain microporous layer 2 in the gas diffusion layer 100. The ion exchange membrane-based binder can refer to the foregoing relevant records. To avoid repetition, it will not be elaborated here. The number of the second microporous layers is not specifically limited. The second microporous layer here contains an ion exchange membrane-based binder, which has a good promoting effect on the transport of ions, and thus can promote more ions to be transported to the catalytic layer to participate in the electrolysis reaction, and further improve the electrolysis efficiency.

[0054] Optionally, the number of the second microporous layers is greater than or equal to 2. Along the direction L away from the support layer 1, the contact angle of the surface of each second microporous layer decreases. Specifically, the ion exchange membrane-based binder has a certain hydrophilicity. The direction L away from the support layer 1 is the direction close to the catalytic layer. The closer to the catalytic layer, the contact angle of the surface of each second microporous layer decreases, that is, the hydrophilicity of each second microporous layer increases. Or rather, the closer to the catalytic layer, the greater the mass ratio of the ion exchange membrane-based binder in each second microporous layer, the stronger the promoting effect on ion transport, and the better the gradient promoting effect on ion transport. Thus, more ions can be promoted to be transported to the catalytic layer to participate in the electrolysis reaction, and further improve the electrolysis efficiency.

[0055] Optionally, along the direction L away from the support layer 1, the contact angle of the surface of each second microporous layer linearly decreases, that is, the closer to the catalytic layer, the hydrophilic linear gradient of each second microporous layer is enhanced. Since the ion exchange membrane-like binder has a certain hydrophilicity, furthermore, the larger the mass ratio of the ion exchange membrane-like binder in a second microporous layer, the stronger the hydrophilicity of this layer may be. That is, the closer to the catalytic layer, the mass ratio of the ion exchange membrane-like binder in each second microporous layer linearly increases, which has a better gradient promotion effect on ion transport and a better promotion effect on the transport of ions. Furthermore, more ions can be promoted to be transported to the catalytic layer to participate in the electrolysis reaction, and thus the electrolysis efficiency can be further improved. The linear decrease in the contact angle of the surface of each second microporous layer along the direction L away from the support layer 1 means that along the direction L away from the support layer 1, the difference in the contact angle of the surface of every two adjacent second microporous layers is equal. It should be noted that throughout the text, the mass ratio of the ion exchange membrane-like binder in each second microporous layer refers to: the mass of the ion exchange membrane-like binder in a certain second microporous layer divided by the total mass of this second microporous layer. The linear increase in the mass ratio of the ion exchange membrane-like binder in each second microporous layer closer to the catalytic layer means that along the direction closer to the catalytic layer, the difference in the mass ratio of the ion exchange membrane-like binder in every two adjacent second microporous layers is equal.

[0056] It should be noted that the ion exchange membrane-like binder here also needs to be determined according to the specific type of the electrolytic cell. Similarly, in the case where the electrolytic cell is an AEM electrolytic cell, the ion exchange membrane-like binder in this second microporous layer is an anion exchange membrane-like binder, which promotes the transport of, such as OH - and improves the electrolysis efficiency. In the case where the electrolytic cell is a PEM electrolytic cell, the ion exchange membrane-like binder in this second microporous layer is a cation exchange membrane-like binder, which promotes the transport of, such as H - and improves the electrolysis efficiency.

[0057] Optionally, the contact angle of the surface of any microporous layer 2 is less than or equal to 50°. The contact angles of the surfaces of the foregoing first microporous layers or second microporous layers can all be within this range. The contact angle of the surface of the microporous layer 2 is of a more appropriate size, which has a more obvious promotion effect on gas transport and also has a more obvious promotion effect on liquid transport, and can further improve the electrolysis efficiency.

[0058] For example, the contact angle of the surface of the microporous layer 2 can be 50°, or 43°, or 40°, or 38°, or 36°, or 30°, or 27°, or 20°, or 15°.

[0059] Optionally, the number of layers of the microporous layer 2 is greater than or equal to 2. Along the direction L away from the support layer 1, the pore diameter of the second pores in each layer of the microporous layer 2 decreases. That is, the closer to the catalytic layer, the smaller the pore diameter of the second pores in the microporous layer 2. The microporous layer closest to the catalytic layer has the smallest difference in pore diameter from the catalytic layer. After the gas is generated in the catalytic layer, it basically does not need to grow and can be desorbed from the surface of the catalytic layer relatively quickly, thereby reducing gas accumulation and enabling the gas to be discharged quickly. Moreover, the formed gas transmission channel has an increasing pore diameter in the direction L towards the support layer, and the gas transmission path is smoother, enabling the gas to be discharged quickly.

[0060] It should be noted that along the direction L away from the support layer 1, the degree of the pore diameter of the second pores in each layer of the microporous layer 2 is not specifically limited. For example, it can be a linear decrease, or a geometric decrease, etc., and no specific limitation is made in this regard. It should be noted that the decrease mentioned throughout the text can be a linear decrease, a multiple decrease, an exponential decrease, etc. The multiple decrease here can be a geometric decrease or a non-geometric decrease, etc., and no specific limitation is made on the specific decrease method. The increase mentioned throughout the text can be a linear increase, a multiple increase, an exponential increase, etc. The multiple increase here can be a geometric increase or a non-geometric increase, etc., and no specific limitation is made on the specific decrease method.

[0061] Optionally, both the microporous layer 2 and the support layer 1 include particles. The particles here can be binder particles, metal particles, etc. The particle size of the particles in the microporous layer 2 is smaller than the particle size of the particles in the support layer 1. The number of layers of the microporous layer 2 is greater than or equal to 2. Along the direction L away from the support layer 1, the particle size of the particles in each layer of the microporous layer 2 decreases. That is, along the direction towards the catalytic layer, the particle size gradient of the particles in each layer of the microporous layer 2 decreases. Furthermore, in each layer of the microporous layer 2 formed, the closer to the catalytic layer, the smaller the pore diameter of the second pores in the microporous layer 2. The microporous layer 2 closest to the catalytic layer has the smallest difference in pore diameter from the catalytic layer. After the gas is generated in the catalytic layer, it basically does not need to grow and can be desorbed from the surface of the catalytic layer relatively quickly, thereby reducing gas accumulation and enabling the gas to be discharged quickly. Moreover, the formed gas transmission channel has an increasing pore diameter in the direction L towards the support layer, and the gas transmission path is smoother, enabling the gas to be discharged quickly.

[0062] Optionally, along the direction L away from the support layer 1, the particle size of the particles in each layer of the microporous layer 2 decreases linearly. The formed gas transmission channel has a linearly increasing pore diameter in the direction L towards the support layer, and the gas transmission path is smoother and more unobstructed, enabling the gas to be discharged quickly. Along the direction L away from the support layer 1, the linear decrease in the particle size of the particles in each layer of the microporous layer 2 means that along the direction L away from the support layer 1, the difference in the particle size between every two adjacent microporous layers 2 is equal.

[0063] Optionally, the particle size of the particles in any microporous layer 2 is from 0.1 μm to 10 μm. The particle size of the particles in the microporous layer 2 is more appropriate, which is conducive to the discharge of gas and the transmission of liquid. For example, the particle size of the particles in the microporous layer 2 is not too large. If it is too large, the pore diameter of the formed second pores has a large gap with the pore diameter of the catalytic layer, which is not conducive to gas discharge. Nor is it too small. If it is too small, the pore diameter of the formed second pores is also not conducive to gas discharge.

[0064] For example, the particle size of the particles in the microporous layer 2 can be 0.1 μm, or 0.3 μm, or 1.1 μm, or 1.8 μm, or 2.2 μm, or 3.5 μm, or 4.4 μm, or 5 μm, or 6.3 μm, or 7.8 μm, or 8.9 μm, or 10 μm.

[0065] Optionally, the microporous layer 2 includes: metal particles, and the metal particles are the main material for forming the second pores. The microporous layer 2 also includes an adhesive. After the metal particles in the microporous layer 2 are bonded by the adhesive, they will stack on each other. However, due to the randomness of the bonding positions and factors such as the shape of the metal particles, there will still be gaps between the stacked metal particles. The second pores in the microporous layer 2 are mainly the gaps existing between the metal particles here. The number of layers of the microporous layer 2 is greater than or equal to 2. Along the direction L away from the support layer 1, the mass ratio of the metal particles in each layer of the microporous layer 2 decreases. As a result, in each layer of the microporous layer 2 formed, the closer to the catalytic layer, the smaller the pore diameter of the second pores in the microporous layer 2. The microporous layer closest to the catalytic layer has the smallest gap with the pore diameter of the catalytic layer. After the gas is generated in the catalytic layer, it basically does not need to grow and can be desorbed from the surface of the catalytic layer relatively quickly, thereby reducing gas accumulation and enabling the gas to be discharged quickly. And the formed gas transmission channel has an increasing pore diameter in the direction L towards the support layer, and the gas transmission path is smoother, enabling the gas to be discharged quickly.

[0066] It should be noted that along the direction L away from the support layer 1, the way of decreasing the mass ratio of the metal particles in each layer of the microporous layer 2 can be linear decrease, geometric decrease, etc., and no specific limitation is made thereto.

[0067] Optionally, the mass ratio of the metal particles in the microporous layer 2 is from 70% to 98%. The mass ratio of the metal particles in the microporous layer 2 is more appropriate, and each layer of the microporous layer formed is more conducive to the discharge of gas and the transmission of liquid. The mass ratio of the metal particles in the microporous layer 2 refers to the mass of the metal particles in the microporous layer 2 divided by the total mass of the microporous layer 2.

[0068] For example, the mass ratio of the particles in the microporous layer 2 can be 70%, or 79%, or 84%, or 86%, or 90%, or 93%, or 95%, or 97%, or 98%.

[0069] Optionally, the porosity of the microporous layer 2 is less than that of the support layer 1; the number of layers of the microporous layer 2 is greater than or equal to 2. Along the direction L away from the support layer 1, the porosity of each layer of the microporous layer 2 decreases. As a result, in each layer of the microporous layer 2 formed, the smaller the pore diameter of the second pores in the microporous layer 2 is, the closer it is to the catalytic layer. The microporous layer closest to the catalytic layer has the smallest difference in pore diameter from the catalytic layer. After the gas is generated in the catalytic layer, it basically does not need to grow and can be desorbed from the surface of the catalytic layer relatively quickly, thereby reducing gas accumulation and enabling the gas to be discharged quickly. Moreover, the formed gas transmission channel has an increasing pore diameter in the direction L towards the support layer, and the gas transmission path is smoother, enabling the gas to be discharged quickly.

[0070] It should be noted that along the direction L away from the support layer 1, the manner in which the porosity of each layer of the microporous layer 2 decreases can be linear decrease, geometric decrease, etc., and no specific limitation is made thereto.

[0071] Optionally, the porosity of the microporous layer 2 is 20% to 60%. The porosity of the microporous layer 2 is relatively appropriate, and each layer of the microporous layer formed is more conducive to gas discharge and liquid transmission.

[0072] For example, the porosity of the microporous layer 2 can be 20%, or 27%, or 35%, or 40%, or 41%, or 43%, or 55%, or 60%.

[0073] Optionally, the support layer 1 is at least one of a metal felt layer, a metal foam layer, and a sintered metal particle layer. The microporous layer 2 includes at least one of titanium particles and titanium oxide particles, nickel particles and nickel oxide particles, and stainless steel particles and stainless steel oxide particles. The titanium particles are micron particles or nano particles. Here, the titanium oxide particles refer to the products after the titanium particles are oxidized, the nickel oxide particles refer to the products after the nickel particles are oxidized, and the stainless steel oxide particles refer to the products after the stainless steel particles are oxidized. The material of the gas diffusion layer is conducive to gas discharge and liquid transmission. At the same time, the sizes of the nickel particles, titanium particles, and stainless steel particles in the microporous layer 2 are all relatively appropriate, and each layer of the microporous layer formed is more conducive to gas discharge and liquid transmission.

[0074] For example, in an AEM electrolytic cell, the microporous layer 2 can include at least one of titanium particles and titanium oxide particles, nickel particles and nickel oxide particles, and stainless steel particles and stainless steel oxide particles. In a PEM electrolytic cell, the microporous layer 2 can include titanium particles and titanium oxide particles.

[0075] The microporous layer 2 can be prepared by a metal sintering method or by preparing a slurry of metal powder or particles using a binder, etc., and is prepared on the support layer 1 by spraying, scraping, coating, transfer printing, etc. No specific limitation is made to the preparation method.

[0076] It should be noted that the pore diameter of a certain structure mentioned throughout the text can be the average pore diameter within the preset area of the structure, or the average pore diameter within the entire structure, or can be the pore diameter of any pore within the structure, and no specific limitation is made in this regard. The contact angle of the surface of the microporous layer 2 mentioned throughout the text can be the average contact angle within the preset surface of the microporous layer 2, or the average contact angle of the entire surface of the entire microporous layer 2, or can be the contact angle at any position on any surface within the microporous layer 2, and no specific limitation is made in this regard. The particle size of the particles in the microporous layer 2 mentioned throughout the text can be the average particle size of the particles within the preset area of the microporous layer 2, or the average particle size of the particles in the entire microporous layer 2, or can be the particle size of the particles at any position within the microporous layer 2, and no specific limitation is made in this regard. The mass ratio of the metal particles in the microporous layer 2 mentioned throughout the text can be the average mass ratio of the metal particles within the preset area of the microporous layer 2, or the average mass ratio of the metal particles in the entire microporous layer 2, or can be the mass ratio of the metal particles at any position within the microporous layer 2, and no specific limitation is made in this regard. The porosity of the microporous layer 2 mentioned throughout the text can be the average porosity within the preset area of the microporous layer 2, or the average porosity of the entire microporous layer 2, or can be the porosity at any position within the microporous layer 2, and no specific limitation is made in this regard.

[0077] It should be noted that the contact angle of the surface of the microporous layer 2 mentioned throughout the text is the water contact angle of the surface of the microporous layer 2 measured by a contact angle tester under room temperature conditions. Specifically, according to the operation instructions of the contact angle tester, a water droplet is dropped on the surface of the microporous layer 2, and the water contact angle of the surface of the microporous layer 2 is measured by the contact angle tester. Usually, it can be measured three times or even more times, and the average value is taken as the contact angle of the surface of the microporous layer 2.

[0078] The present utility model also provides an electrolytic cell, including: a catalytic layer and any one of the aforementioned gas diffusion layers 100 for electrolytic cells. The microporous layer 2 in the gas diffusion layer 100 is located between the catalytic layer and the support layer 1 in the gas diffusion layer 100.

[0079] Optionally, each microporous layer 2 includes: at least one second microporous layer containing an ion exchange membrane type binder. In the case where the electrolytic cell is an AEM electrolytic cell, the ion exchange membrane type binder is an anion exchange membrane type binder; in the case where the electrolytic cell is a PEM electrolytic cell, the ion exchange membrane type binder is a PEM cation of a cation exchange membrane type binder.

[0080] The electrolytic cell here has the same or similar beneficial effects as any one of the aforementioned gas diffusion layers 100 for electrolytic cells, and the relevant parts of the two can be referred to each other. To avoid repetition, it will not be elaborated here.

[0081] The present application will be further explained below in conjunction with specific embodiments.

[0082] Embodiment 1

[0083] Taking the PEM electrolyzed water technology route as an example, the gas diffusion layer of the present application is applied to the anode. The support layer 1 is selected as a 400-μm-thick titanium felt, and a microporous layer 2 is prepared on its surface. Titanium metal particles with a particle size of 1 μm are used, and PTFE is used as a binder. They are dispersed in an ethanol solution to form a uniform slurry. The mass ratio of the titanium metal particles, PTFE, and ethanol solution is 5:1:20. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 10,000 r / min (revolutions per minute), and the dispersion time is 80 min (minutes). It is prepared on the surface of the titanium felt by spraying, with a thickness of 50 μm. After spraying and drying, it is placed in a tube furnace and treated at 300 °C for 1 hour in an air atmosphere. After the temperature drops to room temperature, it is taken out for assembling the electrolytic cell. The average pore diameter of the second pores in the newly prepared microporous layer 2 is 0.8 μm, the porosity is 32%, and the surface contact angle of the microporous layer 2 is 40°. The gas transport layer 100 of Embodiment 1 is as Figure 1 shown, and Figure 1 the microporous layer 2 in corresponds to the first microporous layer. Comparing the performance of the electrolytic cell assembled by this gas transport layer 100 with that of the electrolytic cell assembled with a 400-μm-thick titanium felt as the gas transport layer, under the condition of 1 A / cm 2 (ampere per square centimeter), although the gas transport layer of Embodiment 1 is thicker than the original titanium felt, the cell voltage of the electrolytic cell assembled by the gas transport layer 100 of this Embodiment 1 is 40 mV (millivolts) lower than that of the electrolytic cell assembled with a 400-μm-thick titanium felt as the gas transport layer.

[0084] Embodiment 2

[0085] Taking the PEM electrolytic water technology route as an example, the gas diffusion layer 100 of this second embodiment is applied to the anode. The support layer 1 is made of a 300-μm-thick titanium felt, and a double-layer microporous layer 2 is prepared on its surface. For the preparation of the first microporous layer 2 adjacent to the support layer 1, titanium metal particles with a particle size of 5 μm are used, and PTFE is used as a binder. They are dispersed in an ethanol solution to form a uniform slurry. The mass ratio of the titanium metal particles, PTFE, and ethanol solution is 20:3:20. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 10,000 r / min, and the dispersion time is 30 min. It is prepared on the surface of the titanium felt by means of doctor blade coating, and the thickness is controlled at 50 μm. After the first microporous layer 2 is dried, the second microporous layer 2 is prepared. For the preparation of the second microporous layer 2, titanium metal particles with a particle size of 1 μm are used, and PTFE is used as a binder. They are dispersed in an ethanol solution to form a uniform slurry. The mass ratio of the titanium metal particles, PTFE, and ethanol solution is 5:1:20. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 10,000 r / min, and the dispersion time is 80 min. It is prepared on the surface of the first microporous layer 2 by means of spraying, and the thickness is controlled at 50 μm. After spraying and drying, it is placed in a tube furnace and treated at 300 °C for 1 hour in an air atmosphere. After the temperature drops to room temperature, it is taken out for assembling the electrolytic cell. The average pore size of the first microporous layer 2 is 3 μm, the porosity is 48%, and the surface contact angle is 32°. The average pore size of the second microporous layer 2 is 0.8 μm, the porosity is 32%, and the surface contact angle is 40°. The gas diffusion layer 100 of the second embodiment is as Figure 2 shown, and Figure 2 both of the two microporous layers 2 in 2 correspond to the first microporous layer. Comparing the performance of the electrolytic cell assembled with the gas diffusion layer 100 of this second embodiment with that of the electrolytic cell assembled with a 400-μm-thick titanium felt as the gas diffusion layer, under the condition of 1 A / cm 2 , the cell voltage of the electrolytic cell assembled with the gas diffusion layer 100 of this second embodiment is 55 mV lower than that of the electrolytic cell assembled with a 400-μm-thick titanium felt as the gas diffusion layer.

[0086] Example 3

[0087] Taking the PEM electrolyzed water technology route as an example, the gas diffusion layer 100 of this Example 3 is applied to the anode. The support layer 1 is made of a 300-μm-thick titanium felt, and a multi-layered microporous layer 2 is prepared on its surface. For the preparation of the first microporous layer 2 adjacent to the support layer 1, titanium metal particles with a particle size of 5 μm are used, and PTFE is used as a binder. They are dispersed in an ethanol solution to form a uniform slurry. The mass ratio of the titanium metal particles, PTFE, and ethanol solution is 20:3:20. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 10,000 r / min, and the dispersion time is 30 min. It is prepared on the surface of the titanium felt by means of doctor blade coating, and the thickness is controlled at 50 μm. After the first microporous layer 2 is dried, the second microporous layer 2 is prepared. For the preparation of the second microporous layer 2, titanium metal particles with a particle size of 3 μm are used, and PTFE is used as a binder. They are dispersed in an ethanol solution to form a uniform slurry. The mass ratio of the titanium metal particles, PTFE, and ethanol solution is 15:2:50. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 10,000 r / min, and the dispersion time is 50 min. It is prepared on the surface of the first microporous layer 2 by means of spraying, and the thickness is controlled at 30 μm. For the preparation of the third microporous layer 2, titanium metal particles with a particle size of 1 μm are used, and PTFE is used as a binder. They are dispersed in an ethanol solution to form a uniform slurry. The mass ratio of the titanium metal particles, PTFE, and ethanol solution is 5:1:20. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 10,000 r / min, and the dispersion time is 80 min. It is prepared on the surface of the second microporous layer 2 by means of spraying, and the thickness is controlled at 20 μm.

[0088] After spraying is completed and it is dried, it is placed in a tube furnace and treated at 300 °C for 1.5 hours in an air atmosphere. After the temperature drops to room temperature, it is taken out for assembling the electrolytic cell. The average pore diameter of the newly prepared first microporous layer 2 is 3 μm, the porosity is 48%, and the surface contact angle is 32°. The average pore diameter of the second microporous layer 2 is 1.2 μm, the porosity is 41%, and the surface contact angle of the microporous layer 2 is 36°. The average pore diameter of the third microporous layer 2 is 0.8 μm, the porosity is 32%, and the surface contact angle is 40°. The gas diffusion layer 100 of Example 3 is as Figure 3 shown, and Figure 3 the three microporous layers 2 in 2 are all correspondingly the first microporous layer. Comparing the performance of the electrolytic cell assembled with the gas diffusion layer 100 of this Example 3 with that of the electrolytic cell assembled with a 400-μm-thick titanium felt as the gas diffusion layer, under the condition of 1 A / cm 2 , the cell voltage of the electrolytic cell assembled with the gas diffusion layer 100 of this Example 3 is 70 mV lower than that of the electrolytic cell assembled with a 400-μm-thick titanium felt as the gas diffusion layer.

[0089] Example 4

[0090] Taking the AEM electrolyzed water technology route as an example, the gas diffusion layer structure of this Example 4 is applied to the anode. The support layer 1 is made of a 200-μm-thick nickel felt, and a microporous layer 2 is prepared on its surface. Nickel metal particles with a particle size of 1.5 μm are used, and PTFE is used as a binder. They are dispersed in an ethanol solution to form a uniform slurry. The mass ratio of the titanium metal particles, PTFE, and ethanol solution is 6:1:20. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 10,000 r / min, and the dispersion time is 80 min. It is prepared on the surface of the nickel felt substrate by spraying, with a thickness of 30 μm. After spraying and drying, it is placed in a tube furnace and treated at 350 °C for 0.5 h in an air atmosphere. After the temperature drops to room temperature, it is taken out for assembling the electrolytic cell. The newly prepared microporous layer 2 has an average pore size of 1.0 μm, a porosity of 38%, and a surface contact angle of 36°. The gas diffusion layer 100 of Example 4 is as Figure 1 shown, and Figure 1 in the microporous layer 2 corresponds to the first microporous layer. Comparing the performance of the electrolytic cell assembled with the gas diffusion layer 100 of this Example 4 with that of the electrolytic cell assembled with a 200-μm-thick nickel felt as the gas diffusion layer, under the condition of 1 A / cm 2 , the cell voltage of the electrolytic cell assembled with the gas diffusion layer of this Example 2 is 50 mV lower than that of the electrolytic cell assembled with a 200-μm-thick nickel felt as the gas diffusion layer.

[0091] Example 5

[0092] Taking the AEM electrolyzed water technology route as an example, the gas diffusion layer 100 of this Example 5 is applied to the anode. The support layer 1 is made of a 200-μm-thick nickel felt, and a microporous layer 2 is prepared on its surface. Nickel metal particles with a particle size of 1.5 μm are used, and PTFE is used as a binder. They are dispersed in an ethanol solution to form a uniform slurry. The mass ratio of the titanium metal particles, PTFE, and ethanol solution is 6:1:10. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 12,000 r / min, and the dispersion time is 80 min. It is prepared on the surface of the nickel felt substrate by doctor blading, with a controlled thickness of 30 μm. After preparation and drying, it is placed in a tube furnace and treated at 350 °C for 0.5 h in an air atmosphere. After the temperature drops to room temperature, it is taken out for assembling the electrolytic cell. The newly prepared microporous layer 2 has an average pore size of 0.98 μm, a porosity of 38%, and a surface contact angle of 36°. The gas diffusion layer 100 of Example 5 is as Figure 1 shown, and Figure 1The microporous layer 2 therein corresponds to the first microporous layer. Comparing the performance of the electrolytic cell assembled with the gas transport layer 100 of this Example 5 with that of the electrolytic cell assembled with a 200-μm thick nickel felt as the gas transport layer, under the condition of 1 A / cm 2 The cell voltage of the electrolytic cell assembled with the gas transport layer 100 of this Example 5 is 45 mV lower than that of the electrolytic cell assembled with a 200-μm thick nickel felt as the gas transport layer.

[0093] Example 6

[0094] Taking the AEM electrolytic water technology route as an example, the gas transport layer 100 of this Example 6 is applied to the anode. The support layer 1 is a 300-μm thick nickel felt, and a double-layer microporous layer 2 is prepared on its surface. For the preparation of the first microporous layer 2 close to the support layer 1, nickel metal particles with a particle size of 2 μm are used, and an anion exchange membrane resin is used as a binder, which is dispersed in a DMF solution to form a uniform slurry. The mass ratio of the titanium metal particles, the anion exchange membrane resin, and the DMF solution is 15:3:20. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 15000 r / min, and the dispersion time is 30 min. It is prepared on the surface of the nickel felt by means of doctor blade coating, and the thickness is controlled at 30 μm. After the first microporous layer 2 is dried, the second microporous layer 2 is prepared. For the preparation of the second microporous layer 2, titanium metal powder with a particle size of less than 0.5 μm is used, and an anion exchange membrane resin is used as a binder, which is dispersed in a DMF solution to form a uniform slurry. The mass ratio of the titanium metal particles, the anion exchange membrane resin, and the DMF solution is 5:1:20. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 15000 r / min, and the dispersion time is 50 min. It is prepared on the surface of the first microporous layer 2 by means of spraying, and the thickness is controlled at 20 μm. After spraying and drying, it can be used as the gas transport layer. The average pore diameter of the newly prepared first microporous layer 2 is 0.8 μm, the porosity is 36%, and the surface contact angle is 27°. The average pore diameter of the second microporous layer 2 is 0.3 μm, the porosity is 23%, and the surface contact angle is 21°. The gas transport layer 100 of Example 6 is as Figure 2 shown, and Figure 2 both of the two microporous layers 2 therein correspond to the second microporous layer. Comparing the performance of the electrolytic cell assembled with the gas transport layer of this Example 6 with that of the electrolytic cell assembled with a 350-μm thick titanium felt as the gas transport layer, under the condition of 1 A / cm 2 The cell voltage of the electrolytic cell assembled with the gas transport layer 100 of this Example 6 is 55 mV lower than that of the electrolytic cell assembled with a 350-μm thick titanium felt as the gas transport layer.

[0095] Example 7

[0096] Taking the AEM electrolyzed water technology route as an example, the gas diffusion layer 100 of this Example 7 is applied to the anode. The support layer 1 is a 200-μm-thick nickel felt, and a multi-layered microporous layer 2 is prepared on its surface. The first microporous layer 2 close to the support layer 1 is prepared using nickel metal particles with a particle size of 5 μm. Using PTFE as a binder, it is dispersed in an ethanol solution to form a uniform slurry. The mass ratio of the titanium metal particles, PTFE, and ethanol solution is 20:3:20. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 10,000 r / min, and the dispersion time is 30 min. It is prepared on the surface of the nickel felt substrate by doctor blading, with the thickness controlled at 50 μm. After the first microporous layer 2 is dried, the second microporous layer 2 is prepared. The second microporous layer 2 is prepared using nickel metal particles with a particle size of 2 μm. Using PTFE as a binder, it is dispersed in an ethanol solution to form a uniform slurry. The mass ratio of the titanium metal particles, PTFE, and ethanol solution is 15:2:50. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 10,000 r / min, and the dispersion time is 50 min. It is prepared on the surface of the first microporous layer 2 by spraying, with the thickness controlled at 30 μm. After spraying and drying, it is placed in a tube furnace and treated at 300 °C for 1.5 hours in an air atmosphere. After the temperature drops to room temperature, it is taken out for the preparation of the third microporous layer 2.

[0097] The third microporous layer 2 is prepared using titanium metal powder with a particle size of less than 0.5 μm. Using an anion exchange membrane resin as a binder, it is dispersed in a DMF solution to form a uniform slurry. The mass ratio of the titanium metal particles, anion exchange membrane resin, and DMF solution is 5:1:20. A slurry dispersion device is used for slurry dispersion. During the dispersion process, the stirring rate of the slurry is controlled at 15,000 r / min, and the dispersion time is 50 min. It is prepared on the surface of the second microporous layer 2 by spraying, with the thickness controlled at 20 μm.

[0098] The average pore diameter of the newly prepared first microporous layer 2 is 3 μm, the porosity is 48%, and the surface contact angle is 33°. The average pore diameter of the second microporous layer 2 is 1.2 μm, the porosity is 41%, and the surface contact angle is 36°. The average pore diameter of the third microporous layer 2 is 0.3 μm, the porosity is 23%, and the surface contact angle is 22°. The gas diffusion layer 100 of Example 7 is as Figure 3 shown, and Figure 3 the two microporous layers 2 close to the support layer 1 in 2Under the same conditions, the cell voltage of the electrolytic cell assembled with the gas transport layer 100 of Example 7 is 70 mV lower than that of the electrolytic cell assembled with a 300-μm-thick nickel felt as the gas transport layer.

[0099] The parameter comparison of the above Examples 1 to 7 is shown in the following table. Among them, the particle size, pore size, porosity, and contact angle are all for one layer of the microporous layer 2.

[0100] Table: Parameter Comparison Table of Examples

[0101]

[0102]

[0103] From the above Examples 1 to 7, it can be concluded that for the electrolytic cell formed by the gas diffusion layer 100 provided by the present invention, under the same working conditions, the voltage is relatively low. That is to say, under the same working conditions, compared with the electrolytic cell formed by the gas diffusion layer in the related art, the electrolytic cell formed by the gas diffusion layer 100 provided in this application has lower energy consumption. This shows that through the improvement of factors such as the pore structure, hydrophobicity, hydrophilicity, and ion exchange membrane resin of the microporous layer 2 in the gas diffusion layer 100, the gas diffusion layer provided in this application fully improves the gas discharge speed and liquid transmission rate. The gas discharge speed is faster than that of the gas diffusion layer in the related art, with basically no product accumulation or less product accumulation, and the liquid transmission rate of the electrolytic cell formed by the gas diffusion layer provided in this application is faster than that of the related art, and the electrolysis efficiency is higher.

[0104] More specifically, compared with Embodiment 2, Embodiment 3, Embodiment 6 and Embodiment 7, in Embodiment 1, Embodiment 4 and Embodiment 5, the number of layers of the microporous layer 2 is less. Therefore, in the electrolytic cells of Embodiment 1, Embodiment 4 and Embodiment 5, the gas discharge rate and the liquid transmission rate are not as good as those in Embodiment 2, Embodiment 3, Embodiment 6 and Embodiment 7. In Embodiment 2 and Embodiment 3, the total thickness of the microporous layer 2 is equal. However, in Embodiment 3, the number of layers of the microporous layer 2 is more, and through the cooperation of the contact angles of the surfaces of each layer of the microporous layer, etc. Therefore, in the electrolytic cell of Embodiment 3, both the gas discharge rate and the liquid transmission rate are faster than those in Embodiment 2. In Embodiment 1 and Embodiment 4, the number of layers of the microporous layer 2 is 1 layer. However, in Embodiment 4, the thickness of the microporous layer 2 is smaller, and through the cooperation of factors such as the contact angle of the surface of the microporous layer 2, the porosity of the microporous layer 2, and the pore diameter of the second pores in the microporous layer 2, the gas discharge rate and the liquid transmission rate in the electrolytic cell of Embodiment 4 are both faster than those in Embodiment 1. Through the comparison between Embodiment 4 and Embodiment 5, it can be concluded that the proportion of the dispersion liquid has little influence on the gas discharge rate and the liquid transmission rate in the electrolytic cell. In Embodiment 7, the number of layers of the microporous layer 2 is more, and through the cooperation of the hydrophobic binder and the ion exchange membrane binder, etc., in the electrolytic cell of Embodiment 7, the gas discharge rate and the liquid transmission rate are faster than those in the electrolytic cell of Embodiment 6.

[0105] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including that element.

[0106] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims. All of these fall within the protection scope of the present invention.

Claims

1. A gas diffusion layer for an electrolytic cell, characterized in that: include: Support layer; The support layer has a plurality of first holes; At least one microporous layer laminated on one side of the support layer; Each of the microporous layers comprises: at least one first microporous layer containing a hydrophobic adhesive; and / or, At least one microporous layer is stacked on one side of the support layer; each of the microporous layers includes: at least one second microporous layer containing an ion exchange membrane adhesive; the ion exchange membrane adhesive includes: an anion exchange membrane adhesive, or a cation exchange membrane adhesive; The microporous layer has a plurality of second pores, the pore diameter of the second pores is smaller than the pore diameter of the first pores, and the pore diameter of the second pores is 0.05 μm to 30 μm.

2. The gas diffusion layer for an electrolytic cell according to claim 1, characterized in that: The number of the microporous layers is greater than or equal to 2, and the pore size of the second pores in each microporous layer decreases along a direction away from the support layer.

3. The gas diffusion layer for an electrolytic cell according to claim 1 or 2, characterized in that: The microporous layer and the supporting layer both include particles; the particle size of the particles in the microporous layer is smaller than the particle size of the particles in the supporting layer.

4. The gas diffusion layer for an electrolytic cell according to claim 3, characterized in that: The number of the microporous layers is greater than or equal to 2, and the particle size of particles in each microporous layer decreases along a direction away from the support layer.

5. The gas diffusion layer for an electrolytic cell according to claim 3, characterized in that: The particle size of the particles in the microporous layer is 0.1 μm to 10 μm.

6. The gas diffusion layer for an electrolytic cell according to claim 1, characterized in that: The number of the first microporous layers is greater than or equal to 2, and the contact angle of the surface of each layer of the first microporous layer increases along a direction away from the support layer.

7. The gas diffusion layer for an electrolytic cell according to claim 1, characterized in that: Each of the microporous layers comprises: at least one of the second microporous layer and at least one of the first microporous layer; each of the second microporous layers is farther away from the support layer than all of the first microporous layers.

8. The gas diffusion layer for an electrolytic cell according to claim 1, characterized in that: The number of the second microporous layers is greater than or equal to 2, and the contact angle of the surface of each second microporous layer decreases along a direction away from the support layer.

9. The gas diffusion layer for an electrolytic cell according to claim 1 or 2, characterized in that: The porosity of the microporous layer is less than that of the support layer; the number of the microporous layers is greater than or equal to 2, and the porosity of each microporous layer decreases along a direction away from the support layer.

10. The gas diffusion layer for an electrolytic cell according to claim 9, characterized in that: The porosity of the microporous layer is 20% to 60%.

11. The gas diffusion layer for an electrolytic cell according to claim 1 or 2, characterized in that: The support layer is one of a metal felt layer, a metal foam layer and a sintered metal particle layer; And / or, the contact angle of the surface of the microporous layer is less than or equal to 50°.

12. An electrolytic cell, characterized in that: include: A catalytic layer and a gas diffusion layer for an electrolytic cell as claimed in any one of claims 1 to 11; The microporous layer is located between the support layer and the catalytic layer.

13. The electrolytic cell according to claim 12, characterized in that Each of the microporous layers comprises: at least one second microporous layer containing an ion exchange membrane adhesive; In the case where the electrolytic cell is an AEM electrolytic cell, the ion exchange membrane adhesive is an anion exchange membrane adhesive; When the electrolytic cell is a PEM electrolytic cell, the ion exchange membrane adhesive is a cation exchange membrane adhesive.

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