Gas diffusion layer, preparation method thereof and proton exchange membrane fuel cell

Abstract

The invention provides a gas diffusion layer, a preparation method thereof and a proton exchange membrane fuel cell, and relates to the technical field of fuel cells. The gas diffusion layer comprises a substrate layer and a microporous layer, and the conductive material contained in the microporous layer is of an ordered pore structure. According to the invention, the conductive material with the ordered pore structure is doped into the microporous layer, so that the ordered pore channel is formed in the microporous layer, and the gas diffusion layer through which liquid and gas can quickly pass is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a gas diffusion layer and a preparation method thereof, and a proton exchange membrane fuel cell. Background Art

[0002] The proton exchange membrane fuel cell is mainly composed of a membrane electrode and a bipolar plate. The membrane electrode part includes a proton exchange membrane, a cathode catalyst layer on both sides of the proton exchange membrane, and a gas diffusion layer next to the catalyst layer. The reactants hydrogen and oxygen diffuse through the gas diffusion layer to the anode and cathode catalyst layers respectively, and undergo oxidation and reduction reactions respectively under the action of the catalyst. The protons (H + ) is conducted to the cathode through the proton exchange membrane, and the water (H 2 0) is discharged from the gas diffusion layer in the form of water vapor or condensed water. Usually, when the fuel cell is operated at low temperature and high current, liquid water cannot be discharged in time, which can easily cause flooding and affect the battery performance and life. In other words, the gas diffusion layer is mainly used to support the catalyst layer, transmit current, conduct gas and discharge reactant water. It is one of the main sources of concentration polarization of the entire hydrogen fuel cell system. Reasonable drainage and uniform gas distribution capabilities are key factors affecting the mass transfer of the gas diffusion layer.

[0003] However, the existing gas diffusion layer has a non-connected pore structure in the carbon material used in its microporous layer, and the gas is transmitted through the pores of the stacked carbon material. This gas transmission channel is in a disordered state, the transmission path is long, and the number of channels is small. In the prior art, the pore structure of the microporous layer is adjusted by adding different amounts of pore-forming agents or adding substances with a three-dimensional structure. For example, patent CN116632273A constructs a multi-layer microporous layer, adds different amounts of pore-forming agents in different microporous layers, and establishes a multi-layer gradient pore structure, thereby improving the mass transfer efficiency of the gas diffusion layer. Patent CN116505009A constructs a three-dimensional network structure in the microporous layer by adding silica sol, and improves the porosity and pore structure of this network structure by adding polyvinyl alcohol, thereby improving the drainage capacity and gas diffusion capacity of the microporous layer. However, this method of using a multi-layer microporous layer structure or adding a three-dimensional structured substance such as silica sol has problems such as complex preparation process, high manufacturing cost, and not conducive to mass production during actual implementation. Summary of the invention

[0004] A technical problem to be solved by the present invention is to improve the mass transfer efficiency of the gas diffusion layer while solving the problems of complex preparation process, high manufacturing cost and disadvantages of mass production in the prior art.

[0005] In order to solve the above technical problems, the first aspect of the present invention provides a gas diffusion layer. The gas diffusion layer comprises a substrate layer and a microporous layer; the microporous layer contains a conductive material with an ordered pore structure.

[0006] In some embodiments, the pore size of the conductive material with an ordered pore structure ranges from 10 to 500 nm. In specific implementations, the pore size can be any one or more of 10 nm, 30 nm, 50 nm, 70 nm, 100 nm, 130 nm, 150 nm, 180 nm, 200 nm, 270 nm, 300 nm, 350 nm, 400 nm, 460 nm, and 500 nm.

[0007] In some embodiments, the mass proportion of the conductive material of the ordered pore structure in the microporous layer is 5%-95%. In specific implementations, the mass proportion can be any value of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 55%, 65%, 75%, 85%, 95%.

[0008] In some embodiments, the conductive material with an ordered pore structure is a mixture of one or more of a carbon material with an ordered pore structure, a metal material with an ordered pore structure, and a conductive polymer with an ordered pore structure.

[0009] In some embodiments, one side of the substrate layer is coated with a microporous layer.

[0010] In some embodiments, the carbon material with an ordered pore structure is ordered porous carbon black and / or ordered porous graphene; the metal material with an ordered pore structure is ordered porous titanium; and the conductive polymer with an ordered pore structure is an ordered porous covalent organic framework COF.

[0011] In a second aspect, the present invention provides a proton exchange membrane fuel cell, which comprises any one of the above-mentioned gas diffusion layers.

[0012] In a third aspect, the present invention provides a method for preparing the above-mentioned gas diffusion layer. In specific implementation, the method comprises:

[0013] The conductive material with ordered pore structure, the conventional conductive material, the solvent, the dispersant and the dispersion liquid are mixed in a certain ratio to obtain a microporous layer slurry;

[0014] The microporous layer slurry is coated on a base layer and sintered to obtain a gas diffusion layer.

[0015] In some embodiments, the mass percentage of each component in the microporous layer slurry is: the mass percentage of the conductive material with ordered pore structure is 0.05-5.5%, the mass percentage of the traditional conductive material is 2-15%, the mass percentage of the solvent is 40-95%, the mass percentage of the dispersant is 0.5-15%, and the mass percentage of the dispersion is 0.5-30%.

[0016] In a specific implementation, the mass percentage of the conductive material of the ordered pore structure can be any value among 0.05%, 1.5%, 2.0%, 2.75%, 3.25%, 4.35%, 5.0%, and 5.5%.

[0017] In a specific implementation, the mass percentage of the traditional conductive material can be any value among 2%, 7%, 10%, 13%, and 15%.

[0018] In a specific implementation, the mass percentage of the solvent can be any value among 40%, 55%, 65%, 75%, 85%, and 95%.

[0019] In a specific implementation, the mass percentage of the dispersant can be any value among 0.5%, 3%, 7.5%, 10%, 13.5%, and 15%.

[0020] In a specific implementation, the mass percentage of the dispersion can be any value among 0.5%, 4.5%, 10%, 16%, 21%, 26%, and 30%.

[0021] In some embodiments, the sintering is staged sintering, specifically including: the temperature of the first stage sintering is 80-200°C, and the first stage sintering time is 10-240min; the temperature of the second stage sintering is 250-500°C, and the second stage sintering time is 10-180min.

[0022] In a specific implementation, the temperature of the first stage sintering can be any value or composition range among 80°C, 110°C, 140°C, 170°C, and 200°C.

[0023] In a specific implementation, the first sintering time can be any value or composition range of 10 min, 35 min, 75 min, 135 min, 175 min, and 240 min.

[0024] In a specific implementation, the temperature of the second sintering stage can be any value or composition range among 250°C, 300°C, 340°C, 390°C, 450°C, and 500°C.

[0025] In a specific implementation, the second sintering time can be any value or composition range of 10 min, 45 min, 90 min, 130 min, 160 min, and 180 min.

[0026] The present invention adopts the method of doping a conductive material with an ordered pore structure into a microporous layer to form an ordered pore structure in the microporous layer, and at the same time controls the thickness of the microporous layer based on the ordered structure, thereby improving the drainage capacity and gas distribution capacity of the obtained gas diffusion layer, thereby improving the comprehensive performance of the membrane electrode.

[0027] On the other hand, the present invention uses solid powder with an ordered pore structure as the material of the microporous layer. Since the solid powder is added as an auxiliary agent in the preparation of the microporous layer, the amount of the ordered pore structure material is reduced, thereby achieving control of the manufacturing cost. In addition, the traditional calcination process is still used in the preparation process, so the preparation process also has the advantages of being simple and easy to operate. Furthermore, since the raw materials for preparing the microporous layer of the present invention are all solid powders, batch production is possible.

[0028] In summary, the gas diffusion layer provided by the present invention can not only improve the mass transfer efficiency of the gas diffusion layer, but also solve the problems existing in the prior art of complex preparation process, high manufacturing cost and disadvantageous for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of the structure of a gas diffusion layer disclosed in an embodiment of the present invention is shown;

[0031] Figure 2 A schematic diagram showing a structural comparison between a microporous layer provided by an embodiment of the present invention and a traditional microporous layer is shown;

[0032] Figure 3 A structural comparison diagram of the ordered hole material used in the present invention and the traditional disordered hole, traditional solid and traditional blind hole materials is shown;

[0033] Figure 4 A comparison chart of the electrical properties of Example 2 of the present invention and Comparative Examples 1 and 2 is shown. DETAILED DESCRIPTION

[0034] The following is a further detailed description of the embodiments of the present invention in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present invention, but cannot be used to limit the scope of the present invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0035] The present invention provides these embodiments to make the present invention thorough and complete, and fully express the scope of the present invention to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of materials, numerical expressions and numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary, rather than as limiting.

[0036] It should be noted that, in the description of the present invention, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0037] In addition, the words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different parts. "Vertical" is not strictly perpendicular, but is within the tolerance range. "Parallel" is not strictly parallel, but is within the tolerance range. "Include" or "comprising" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0038] All terms used in the present invention have the same meanings as those understood by ordinary technicians in the field to which the present invention belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0039] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0040] In a first aspect, an embodiment of the present invention provides a gas diffusion layer. Figure 1 FIG. 1 shows a schematic diagram of the structure of a gas diffusion layer disclosed in an embodiment of the present invention. Figure 1 As shown, the gas diffusion layer includes a substrate layer and a microporous layer; the microporous layer contains a conductive material with an ordered pore structure.

[0041] Figure 2 FIG. 2 shows a schematic diagram comparing the structures of the microporous layer provided by an embodiment of the present invention and a conventional microporous layer. Figure 2As shown, the present invention uses a conductive material with an ordered pore structure as the solid powder material of the microporous layer, providing more and better gas distribution and water management channels, shortening the transmission path, thereby reducing the mass transfer resistance of the gas in a high-electric density environment and improving the membrane electrode performance.

[0042] Figure 3 The structure comparison diagram of the conductive material with ordered pore structure used in the present invention (referred to as "ordered pore material") and the traditional disordered pore, traditional solid and traditional blind pore materials is shown. Figure 3 As shown in the structural comparison diagram, compared with solid and blind hole materials, the ordered hole material used in the present invention increases the transmission channel; compared with disordered holes, the ordered hole material used in the present invention shortens the transmission distance.

[0043] In some embodiments, the pore size of the conductive material with an ordered pore structure ranges from 10 to 500 nm. In specific implementations, the pore size can be any one or more of 10 nm, 30 nm, 50 nm, 70 nm, 100 nm, 130 nm, 150 nm, 180 nm, 200 nm, 270 nm, 300 nm, 350 nm, 400 nm, 460 nm, and 500 nm.

[0044] In the specific implementation, if the pore size is too small, the transmission resistance of water from the catalyst layer to the substrate layer will increase, and the performance will be reduced; if the pore size is too large, water cannot be discharged in time, which may cause flooding and reduce the performance. Therefore, in this embodiment, based on the structural characteristics of the ordered pore structure and the comprehensive consideration of shortening the ordered channel path as much as possible, the optimal pore size range is 10-60nm.

[0045] In some embodiments, the mass proportion of the conductive material of the ordered pore structure is 5%-95%. In specific implementations, the mass proportion can be any value of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 55%, 65%, 75%, 85%, 95%.

[0046] Among them, in the specific implementation, based on the comprehensive consideration of the formation of ordered pore channels, shortening the ordered channel path as much as possible, cost and electrode performance, the optimal value range of the content ratio is 15%-70%.

[0047] In some embodiments, the conductive material of the ordered pore structure is a mixture of one or more of a carbon material of the ordered pore structure, a metal material of the ordered pore structure, and a conductive polymer of the ordered pore structure. In the specific implementation, the carbon material of the ordered pore structure can be ordered porous carbon black, ordered porous graphene, etc., the metal material of the ordered pore structure can be ordered porous titanium, and the conductive polymer of the ordered pore structure can be an ordered porous covalent organic framework COF.

[0048] In some embodiments, one side of the substrate layer is coated with a microporous layer.

[0049] In order to ensure the pore access rate between the base layer and the microporous layer, the base layer preferably has a pore size ranging from 10 to 100 μm.

[0050] In a second aspect, the present invention provides a proton exchange membrane fuel cell, which comprises any one of the above-mentioned gas diffusion layers.

[0051] In a third aspect, the present invention provides a method for preparing the above-mentioned gas diffusion layer. In specific implementation, the method comprises:

[0052] The conductive material with ordered pore structure, the conventional conductive material, the solvent, the dispersant and the dispersion liquid are mixed in a certain ratio to obtain a microporous layer slurry;

[0053] The microporous layer slurry is coated on a base layer and sintered to obtain a gas diffusion layer.

[0054] In some embodiments, the mass percentage of each component in the microporous layer slurry is: the mass percentage of the conductive material with ordered pore structure is 0.05-5.5%, the mass percentage of the traditional conductive material is 2-15%, the mass percentage of the solvent is 40-95%, the mass percentage of the dispersant is 0.5-15%, and the mass percentage of the dispersion is 0.5-30%.

[0055] In a specific implementation, the mass percentage of the conductive material of the ordered pore structure can be any value among 0.05%, 1.5%, 2.0%, 2.75%, 3.25%, 4.35%, 5.0%, and 5.5%.

[0056] In a specific implementation, the mass percentage of the traditional conductive material can be any value among 2%, 7%, 10%, 13%, and 15%.

[0057] In a specific implementation, the mass percentage of the solvent can be any value among 40%, 55%, 65%, 75%, 85%, and 95%.

[0058] In a specific implementation, the mass percentage of the dispersant can be any value among 0.5%, 3%, 7.5%, 10%, 13.5%, and 15%.

[0059] In a specific implementation, the mass percentage of the dispersion can be any value among 0.5%, 4.5%, 10%, 16%, 21%, 26%, and 30%.

[0060] In some embodiments, the sintering is staged sintering, specifically including: the temperature of the first stage sintering is 80-200°C, and the first stage sintering time is 10-240min; the temperature of the second stage sintering is 250-500°C, and the second stage sintering time is 10-180min.

[0061] In a specific implementation, the temperature of the first stage sintering can be any value or composition range among 80°C, 110°C, 140°C, 170°C, and 200°C.

[0062] In a specific implementation, the first sintering time can be any value or composition range of 10 min, 35 min, 75 min, 135 min, 175 min, and 240 min.

[0063] In a specific implementation, the temperature of the second sintering stage can be any value or composition range among 250°C, 300°C, 340°C, 390°C, 450°C, and 500°C.

[0064] In a specific implementation, the second sintering time can be any value or composition range of 10 min, 45 min, 90 min, 130 min, 160 min, and 180 min.

[0065] The present invention adopts the method of doping a conductive material with an ordered pore structure into a microporous layer to form an ordered pore structure in the microporous layer, and at the same time controls the thickness of the microporous layer based on the ordered structure, thereby improving the drainage capacity and gas distribution capacity of the obtained gas diffusion layer, thereby improving the comprehensive performance of the membrane electrode.

[0066] On the other hand, the present invention uses solid powder with an ordered pore structure as the material of the microporous layer. Since the solid powder is added as an auxiliary agent in the preparation of the microporous layer, the amount of the ordered pore structure material is reduced, thereby achieving control of the manufacturing cost. In addition, the traditional calcination process is still used in the preparation process, so the preparation process also has the advantages of being simple and easy to operate. Furthermore, since the raw materials for preparing the microporous layer of the present invention are all solid powders, batch production is possible.

[0067] In summary, the gas diffusion layer provided by the present invention can not only improve the mass transfer efficiency of the gas diffusion layer, but also solve the problems existing in the prior art of complex preparation process, high manufacturing cost and disadvantageous for mass production.

[0068] In order to enable those skilled in the art to better understand the gas diffusion layer and its preparation process provided by the present invention, the applicant will explain it in conjunction with the following specific embodiments. The raw materials, reagents and equipment used in the following embodiments that are not described are all existing commercially available products.

[0069] Example 1

[0070] Step 1, take 0.04g of carbon powder with an ordered pore structure (purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.) with a pore size of 10-60nm, 3.96g of traditional carbon black (Vulcan XC-72R), add 42.3g of water, 1g of dispersant (Triton X-100), and 0.67g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0071] Step 2: carbon paper (Avcarb EP40T) is selected as the substrate, the above microporous layer slurry is coated on the substrate, sintered at 120° C. for 30 min and 350° C. for 30 min to obtain a gas diffusion layer.

[0072] Example 2

[0073] Step 1, take 0.6g of carbon powder with an ordered pore structure (purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.), with a pore size of 10-60nm, 3.4g of traditional carbon black (Vulcan XC-72R), add 47.2g of water, 1g of dispersant (Triton X-100), and 0.67g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0074] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0075] Example 3

[0076] Step 1, take 1.4g of carbon powder with an ordered pore structure (purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.), with a pore size of 10-60nm, 2.6g of traditional carbon black (Vulcan XC-72R), add 50.6g of water, 1g of dispersant (Triton X-100), and 0.67g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0077] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0078] Example 4

[0079] Step 1, take 2.6g of carbon powder with an ordered pore structure (purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.), with a pore size of 10-60nm, 1.4g of traditional carbon black (Vulcan XC-72R), add 59.5g of water, 1g of dispersant (Triton X-100), and 0.67g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0080] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0081] Example 5

[0082] Step 1, take 2.8g of carbon powder with an ordered pore structure (purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.), with a pore size of 10-60nm, 1.2g of traditional carbon black (Vulcan XC-72R), add 63.1g of water, 1g of dispersant (Triton X-100), and 0.67g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0083] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0084] Example 6

[0085] Step 1, take 3.96g of carbon powder with an ordered pore structure (purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.), with a pore size of 10-60nm, 0.04g of conventional carbon black (Vulcan XC-72R), add 66.8g of water, 1g of dispersant (TritonX-100), and 0.67g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0086] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0087] Example 7

[0088] Step 1, take 1.4g of carbon powder with an ordered pore structure (purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.), with a pore size of 100-200nm, 2.6g of conventional carbon black (Vulcan XC-72R), add 50.6g of water, 1g of dispersant (Triton X-100), and 0.67g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0089] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0090] Example 8

[0091] Step 1, take 1.4g of carbon powder with an ordered pore structure (purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.), with a pore size of 300-500nm, 2.6g of conventional carbon black (Vulcan XC-72R), add 50.6g of water, 1g of dispersant (Triton X-100), and 0.67g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and uniform dispersion;

[0092] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0093] Example 9

[0094] Step 1, take 0.8 g of a covalent organic framework COF material with an ordered pore structure (purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.), 3.2 g of conventional carbon black (Vulcan XC-72R), add 39.2 g of water, 1 g of a dispersant (Triton X-100), and 0.67 g of a 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0095] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0096] Comparative Example 1

[0097] Step 1, take 4g of solid carbon black (acetylene black, Nippon Denka Co., Ltd.), add 28.8g of water, 1g of dispersant (TritonX-100), and 0.67g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0098] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0099] Comparative Example 2

[0100] Step 1, take 4g of conventional carbon black (Vulcan XC-72R), add 50.6g of water, 1g of dispersant (Triton X-100), and 0.67g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0101] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0102] The gas diffusion layers obtained from all the above embodiments and comparative examples were assembled with CCM into membrane electrodes and subjected to electrical performance tests. The test conditions were: temperature 80°C, relative humidity of both the cathode and anode was 50%, stoichiometric ratio anode / cathode = 1.5 / 2.5, pressure anode / cathode = 130 kPa / 120 kPa. The performance summary data are shown in Table 1.

[0103] Table 1 Summary of electrical performance data of Examples 1-9 and Comparative Examples 1-2

[0104]

[0105] It can be seen from Table 1 that the performance of Examples 1-9 is better than that of Comparative Example 2, which indicates that when a certain proportion of conductive material with an ordered pore structure is added to the microporous layer, the performance can be significantly improved.

[0106] By comparing Examples 1 to 6, it can be seen that when the proportion of the conductive material added is too low or too high, the performance improvement effect is weak. Only by adding a suitable proportion (as shown in Examples 2 to 5) of the ordered pore structure conductive material can the performance be optimal.

[0107] In addition, the performance of Examples 3, 7 and 9 is compared, indicating that the pore size within 10-500nm can achieve good performance, and the pore size is 100-200nm The performance is the best. Among them, if the pore size is too small, the transmission resistance of water from the catalyst layer to the substrate layer will increase, reducing the performance; if the pore size is too large, water cannot be discharged in time, which is easy to cause flooding and reduce the performance.

[0108] Figure 4 The electrical performance comparison diagram of Example 2 of the present invention and Comparative Examples 1 and 2 is shown. Figure 3 and Figure 4 As shown, from the performance comparison between Example 2 and Comparative Example 1 and Comparative Example 2, it can be seen that at 1.0 A / cm 2 After electrical density, especially at high current density, the performance of the gas diffusion layer membrane electrode with ordered pore structure materials is significantly improved compared to that of blind hole and solid structure materials. Therefore, by using this invention, the gas transmission capacity is enhanced, water flooding can be avoided at high electrical density, the mass transfer capacity is improved, and the electrical performance is thereby improved.

[0109] Example 10

[0110] Step 1, take 0.04g of carbon powder with an ordered pore structure, the pore size is 10-60nm, 3.96g of conventional carbon black (Vulcan XC-72R), add 15g of water, 5.2g of dispersant (Triton X-100), 10.5g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0111] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0112] Embodiment 11

[0113] Step 1, take 0.04g of carbon powder with an ordered pore structure, the pore size of which is 10-60nm, 3.96g of conventional carbon black (Vulcan XC-72R), add 18g of water, 3g of dispersant (Triton X-100), and 5g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and dispersion;

[0114] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0115] Example 12

[0116] Step 1, take 0.04g of carbon powder with an ordered pore structure, the pore size of which is 10-60nm, 3.96g of conventional carbon black (Vulcan XC-72R), add 25g of water, 1.5g of dispersant (Triton X-100), and 2g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and uniform dispersion;

[0117] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0118] Embodiment 13

[0119] Step 1, take 0.04g of carbon powder with an ordered pore structure, the pore size of which is 10-60nm, 3.96g of conventional carbon black (Vulcan XC-72R), add 43g of water, 1g of dispersant (Triton X-100), and 20% by mass of polytetrafluoroethylene dispersion 1 in sequence, and obtain a microporous layer slurry after ball milling and dispersion evenly;

[0120] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0121] Embodiment 14

[0122] Step 1, take 0.04g of carbon powder with an ordered pore structure, the pore size of which is 10-60nm, 3.96g of conventional carbon black (Vulcan XC-72R), add 80g of water, 0.4g of dispersant (Triton X-100), and 0.4g of 20% polytetrafluoroethylene dispersion in sequence, and obtain a microporous layer slurry after ball milling and uniform dispersion;

[0123] Step 2 is the same as step 2 in Example 1 and will not be described in detail in this example.

[0124] Table 2 Summary of electrical performance data of Examples 10-14

[0125]

[0126] It can be seen from Table 2 that by controlling the ratio of the components in the microporous layer slurry within a certain range and adopting the sintering process provided in this embodiment, the gas diffusion layer finally obtained has relatively good performance.

[0127] Embodiment 15

[0128] Step 1 is the same as step 1 of Example 1 and will not be described in detail in this example;

[0129] Step 2: carbon paper (Avcarb EP40T) is selected as the substrate, the above microporous layer slurry is coated on the substrate, sintered at 50° C. for 120 min and 350° C. for 30 min to obtain a gas diffusion layer.

[0130] Example 16

[0131] Step 1 is the same as step 1 of Example 1 and will not be described in detail in this example;

[0132] Step 2: Carbon paper (Avcarb EP40T) is selected as the substrate, the above microporous layer slurry is coated on the substrate, sintered at 200° C. for 10 min and 350° C. for 30 min to obtain a gas diffusion layer.

[0133] Embodiment 17

[0134] Step 1 is the same as step 1 of Example 1 and will not be described in detail in this example;

[0135] Step 2: carbon paper (Avcarb EP40T) is selected as the substrate, the above microporous layer slurry is coated on the substrate, sintered at 120° C. for 30 min and 250° C. for 180 min to obtain a gas diffusion layer.

[0136] Embodiment 18

[0137] Step 1 is the same as step 1 of Example 1 and will not be described in detail in this example;

[0138] Step 2: Carbon paper (Avcarb EP40T) is selected as the substrate, the above microporous layer slurry is coated on the substrate, sintered at 120° C. for 30 min and 350° C. for 180 min to obtain a gas diffusion layer.

[0139] Embodiment 19

[0140] Step 1 is the same as step 1 of Example 1 and will not be described in detail in this example;

[0141] Step 2: Carbon paper (Avcarb EP40T) is selected as the substrate, the above microporous layer slurry is coated on the substrate, sintered at 120° C. for 30 min and 500° C. for 10 min to obtain a gas diffusion layer.

[0142] Table 3 Summary of electrical performance data of Examples 15-19

[0143]

[0144] It can be seen from Table 3 that when the ratio of the components in the microporous layer slurry is constant, the gas diffusion layer finally obtained by using the sintering process provided in this embodiment has relatively good performance.

[0145] The present invention applies a conductive material with an ordered pore structure to the microporous layer, provides more ordered gas transmission channels, shortens the transmission distance, reduces mass transfer resistance, and thus improves membrane electrode performance. The invention has low cost, simple operation, improved performance, and high practicality.

[0146] So far, various embodiments of the present invention have been described in detail. In order to avoid obscuring the concept of the present invention, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0147] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.

Claims

1. A gas diffusion layer, characterized in that: The gas diffusion layer comprises a substrate layer and a microporous layer; the microporous layer contains a conductive material with an ordered pore structure.

2. The gas diffusion layer according to claim 1, characterized in that The pore size range of the conductive material with the ordered pore structure is 10-500 nm.

3. The gas diffusion layer according to claim 2, characterized in that: The mass proportion of the conductive material of the ordered pore structure in the microporous layer is 5%-95%.

4. The gas diffusion layer according to claim 3, characterized in that: The conductive material with an ordered pore structure is a mixture of one or more of a carbon material with an ordered pore structure, a metal material with an ordered pore structure and a conductive polymer with an ordered pore structure.

5. The gas diffusion layer according to claim 4, characterized in that The carbon material with the ordered pore structure is ordered porous carbon black and / or ordered porous graphene; the metal material with the ordered pore structure is ordered porous titanium; and the conductive polymer with the ordered pore structure is an ordered porous covalent organic framework COF.

6. The gas diffusion layer according to claim 1, characterized in that A microporous layer is formed on at least one side of the base layer.

7. A proton exchange membrane fuel cell, characterized in that: A fuel cell comprises the gas diffusion layer according to any one of claims 1 to 6.

8. A method for preparing a gas diffusion layer according to any one of claims 1 to 6, characterized in that: The method comprises: The conductive material with ordered pore structure, the conventional conductive material, the solvent, the dispersant and the dispersion liquid are mixed in a certain ratio to obtain a microporous layer slurry; The microporous layer slurry is coated on a base layer and sintered to obtain a gas diffusion layer.

9. The method according to claim 8, characterized in that The mass percentages of the components in the microporous layer slurry are: 0.05-5.5% of the conductive material with ordered pore structure, 2-15% of the traditional conductive material, 40-95% of the solvent, 0.5-15% of the dispersant, and 0.5-30% of the dispersion.

10. The method according to claim 8, characterized in that The sintering is staged sintering, specifically including: the temperature of the first stage sintering is 80-200°C, and the sintering time of the first stage is 10-240min; the temperature of the second stage sintering is 250-500°C, and the sintering time of the second stage is 10-180min.

Images