CN114267850B - Novel gas diffusion layer for fuel cell and preparation method and application thereof - Google Patents
Novel gas diffusion layer for fuel cell and preparation method and application thereof Download PDFInfo
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
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- Inert Electrodes (AREA)
Abstract
The invention belongs to the technical field of hydrogen fuel cells, and particularly relates to a novel gas diffusion layer for a fuel cell, and a preparation method and application thereof. Dissolving carbon powder particles in a solvent under the actions of ultrasonic, ball milling, yarn milling or high-speed shearing to form a stable suspension, sequentially adding a hydrophobic agent emulsion, a pore-increasing fiber and a thickening adhesive, and mixing and stirring to obtain microporous layer slurry; uniformly coating the prepared microporous layer slurry on one side surface of a substrate layer, and drying to prepare a microporous layer; and then sintering the mixture in a protective atmosphere to obtain the gas diffusion layer for the fuel cell. The invention adds the degradable fiber into the microporous layer, and the porous channel can be formed by high-temperature sintering, so that the proportion of non-porous holes in the microporous layer can be greatly reduced, the mass transfer efficiency of the fuel cell can be improved during operation, and the drainage performance can be enhanced.
Description
Technical Field
The invention belongs to the technical field of hydrogen fuel cells, and particularly relates to a novel gas diffusion layer for a fuel cell, and a preparation method and application thereof.
Background
The fuel cell is a type of cell which converts chemical energy into electric energy through electrochemical reaction, wherein the hydrogen fuel cell takes hydrogen and oxygen as fuel, water as a product, and from the aspects of energy consumption and environmental pollution, zero emission can be truly realized, the pollution is low, and the fuel cell has a very good application prospect.
The fuel cell is a chemical device for directly converting chemical energy of fuel into electric energy, and its core component membrane electrode mainly consists of proton exchange membrane, catalyst and gas diffusion layer. The gas diffusion layer not only plays roles of supporting the catalyst layer and stabilizing the electrode structure in the electrode, but also has multiple functions of providing a gas channel, an electronic channel and a drainage channel for electrode reaction. With the development of fuel cell technology, there is an increasing demand for the output of the power density of the single cell of the fuel cell, and the water management inside the fuel cell has a direct effect on the power output of the fuel cell. The gas diffusion layer serves as an important role in supporting the catalytic layer, collecting electric current, conducting gas, and discharging reaction product water in the fuel cell.
In the current preparation technology of the gas diffusion layer, conductive carbon black is mainly coated on base layer carbon paper uniformly to form the porous material, and the porous material is formed by the high specific surface area and the geometric shape of carbon black particles, so that the effects of supporting, charge transfer, mass transfer and water drainage are achieved.
The invention of China (application number 202010064394.2) discloses a porous carbon film of a fuel cell gas diffusion layer and a preparation method thereof, and is characterized in that the porous carbon film is realized by thermally curing an expansion pore-forming agent to form a porous structure, wherein the expansion pore-forming agent is thermal expansion agent coated sublimation pore-forming agent particles, and in the thermal curing process, the sublimation pore-forming agent particles are heated to sublimate and promote the expansion agent to grow up, and the inside of the film has larger transverse internal stress under the action of a die, so that pores can be provided for the gas diffusion layer. The microporous layer of the gas diffusion layer is tested by mercury intrusion method, and the differences among the closed holes, the half through holes and the through holes cannot be identified, so that the following problems are caused: although the gas diffusion layer has larger porosity, the gas flow is difficult to uniformly distribute in the plane of the gas diffusion layer; in addition, the effective gas flow is limited in the direction perpendicular to the gas diffusion layer, so that insufficient reaction, flooding and current effective transmission are easily caused.
The Chinese patent application number 202110690914.5 discloses a gas diffusion layer for balancing the water balance in a fuel cell and a preparation method thereof, and is characterized in that the gas diffusion layer comprises a basal layer and a microporous layer, the microporous layer is made of conductive carbon powder and a hydrophobic material, and the hydrophobic gradient is formed by changing the proportion of a hydrophobic agent, so that the hydrophobic gradient of the microporous layer is gradually increased along the air flow direction. The gas diffusion layer is only designed in the hydrophobic gradient direction, the influence of the pore structure on the drainage effect is not considered, and the pore-forming agent such as ammonium carbonate, ammonium bicarbonate and lithium carbonate is used, so that an effective gradient through hole structure is difficult to form.
Disclosure of Invention
Aiming at the problems existing in the prior art, the invention provides a novel gas diffusion layer for a fuel cell, and a preparation method and application thereof.
In order to achieve the above purpose, the present invention is realized by the following technical scheme:
the invention provides a novel gas diffusion layer for a fuel cell, which consists of a basal layer and a microporous layer, wherein the microporous layer is prepared by coating a fiber slurry containing easy degradation on one side of the surface of the basal layer; the easily degradable fiber is protein fiber, cellulose fiber, chitin fiber, polyvinyl alcohol fiber, polyhydroxyalkanoate fiber or polylactic acid fiber. By adding the degradable fiber as the pore-increasing filler, effective through holes can be formed after high-temperature sintering, invalid closed holes and non-through holes are reduced or eliminated, and the mass transfer and drainage effects of the gas diffusion layer are improved.
The second aspect of the present invention provides a method for preparing the gas diffusion layer for a novel fuel cell, comprising the steps of:
Step 1: dissolving carbon powder particles in a solvent under the actions of ultrasonic, ball milling, yarn milling or high-speed shearing to form a stable suspension, sequentially adding a hydrophobic agent emulsion, a pore-increasing fiber and a thickening adhesive, and mixing and stirring to obtain microporous layer slurry;
Step 2: uniformly coating the microporous layer slurry prepared in the step 1 on one side surface of a substrate layer, and drying to prepare a microporous layer;
Step 3: and after the drying is finished, sintering the material in a protective atmosphere to obtain the gas diffusion layer for the fuel cell.
By adopting the technical scheme, the degradable fibers which are uniformly dispersed in the microporous layer can be decomposed into micromolecular gas after high-temperature sintering, the micromolecular gas is discharged out of the microporous layer, occupies a flow passage formed by volume residues, and is mutually overlapped to form a through hole. On one hand, because the hole-increasing fibers are randomly arranged in the slurry and are mutually overlapped, a disordered through hole network structure in the direction in the plane of the gas diffusion layer can be formed, and the uniform arrangement and effective conduction of gas are facilitated; on the other hand, a certain number of through holes can be formed in the direction perpendicular to the gas diffusion layer, so that the effects of increasing gas conduction and discharging reactant water in the vertical direction are realized.
Further, the mass percentage of each component in the microporous layer slurry is as follows: 50-70% of carbon powder particles, 15-30% of hydrophobic agent emulsion, 0.5-12% of pore-increasing fibers and 5-20% of thickening adhesive.
Further, the carbon powder particles are one or more of carbon black, acetylene black, activated carbon, carbon nanotubes, flexible graphite, graphene and carbon fiber powder; the particle diameter of the carbon powder particles is 5 nm-200 nm, and the specific surface area is 50-800 m 2/g.
Further, the hydrophobic agent emulsion is one of Polytetrafluoroethylene (PTFE), fluorinated Ethylene Propylene (FEP), ethylene tetrafluoroethylene copolymer (ETFE), soluble Polytetrafluoroethylene (PFA) and polyvinylidene fluoride homopolymer (PVDF); the solid content of the hydrophobe emulsion is more than or equal to 40 percent, and the hydrophobe emulsion is uniformly stirred by a high-speed shearing and dispersing machine before use.
Further, the hole-increasing fibers are easily degradable chopped fibers including protein fibers, cellulose fibers, chitin fibers, polyvinyl alcohol (PVA) fibers, polyhydroxyalkanoate (PHA) fibers, and polylactic acid (PLA) fibers; the diameter of the hole-increasing fiber is 0.05-2 mu m, the length-diameter ratio is more than or equal to 5, and the bending rigidity is more than or equal to 5 multiplied by 10 -4cN·cm2.
The performance and proportioning design of the hole-increasing fiber directly influence the hole structure of the gas diffusion layer and the mass transfer and drainage performance. The through hole structure matched with the basal layer can enable the interface to be combined more tightly, and the gas transmission and the electron conduction are smoother; the larger length-diameter ratio and bending rigidity are beneficial to the lap joint formation of more effective through holes in the microporous layer, and the influence of non-through holes on the performance of the gas diffusion layer is reduced. In addition, the flow channel is formed into a small-diameter tubular flow channel, and water passes through the small-diameter tubular flow channel due to capillary effect, so that the water is more beneficial to rapid discharge under the influence of water surface tension, and the flooding condition of the gas diffusion layer is avoided. The porous layer is coated in multiple layers by regulating and controlling the proportion of the porous layer pore-increasing filler, so that the pore diameter gradient design change is achieved, and the function of draining and moisturizing the catalyst in the membrane electrode can be achieved.
Further, the thickening adhesive is a pasty material formed by adsorbing water by a high molecular polymer, and comprises carboxymethyl cellulose (CMC), hydroxypropyl methyl cellulose (HPMC), sodium carboxymethyl cellulose (CMC-Na), methyl Cellulose (MC), sodium Polyacrylate (PAAS), polyacrylamide (PAM), polyethylene oxide (PEO), polyvinylpyrrolidone (PVP), starch, agar, gelatin and dextrin; the viscosity of the thickened binder is 0.2 pa.s to 20 pa.s.
Further, the solvent is one or more of methanol, ethanol, isopropanol, n-butanol, glycol, glycerol and water.
Further, the substrate layer is carbon paper, woven carbon cloth or non-woven carbon cloth; the basal layer is subjected to hydrophobic treatment, and the surface contact angle is more than or equal to 135 degrees.
Further, the slurry coating mode is one of a coater, a spray gun and a scraper; the coating process can be single-layer coating or multi-layer coating; the number of the coating layers is 1-10, and the proportion of each component of each layer of coating slurry can be the same or different; the drying temperature after coating is 50-120 ℃; the thickness of the microporous layer is 10-80 μm.
Further, the protective atmosphere in the sintering process is one of air, nitrogen, oxygen, argon and helium; the sintering temperature adopts two-section sintering, and the first section: the sintering temperature is 210-260 ℃ and the sintering time is 30min; and a second section: the sintering temperature is 330-380 ℃ and the sintering time is 30min.
The third aspect of the invention provides an application of the novel gas diffusion layer for the fuel cell in preparing the fuel cell.
Compared with the prior art, the invention has the following beneficial effects:
The invention adds the degradable fiber into the microporous layer, and the porous channel can be formed by high-temperature sintering, so that the proportion of non-porous holes in the microporous layer can be greatly reduced, the mass transfer efficiency of the fuel cell can be improved during operation, and the drainage performance can be enhanced. The formed through holes are arranged in a non-oriented way in the three-dimensional space to form a network structure, so that on one hand, the uniform arrangement and effective conduction of the gas are facilitated in the direction in the plane of the gas diffusion layer; on the other hand, the effect of increasing gas conduction and discharging reactant water is achieved in the direction perpendicular to the gas diffusion layer. In addition, the proportion and the coating number of the coating slurry enable the microporous layer to generate performance gradient difference to cause gradient pressure difference, so that the water draining and moisturizing effect can be further increased, and the performance of the fuel cell is improved.
Drawings
FIG. 1 is a schematic cross-sectional view of a gas diffusion layer according to the present invention;
FIG. 2 is a schematic cross-sectional structure of a gas diffusion layer prepared from a conventional pore-forming agent;
FIG. 3 is a schematic diagram of gas flow conductance of a gas diffusion layer according to the present invention;
FIG. 4 is a polarization graph of example 1 and comparative example;
The gas in the 1-microporous layer, the 2-basal layer, the 3-non-through holes, the 4-gas transmission flow channel, the 5-basal layer flows along the direction vertical to the plane, the 6-basal layer flows along the direction vertical to the plane, the 7-microporous layer flows along the direction vertical to the plane, the 8-microporous layer flows along the direction vertical to the plane, and the 9-bipolar plate.
Detailed Description
The following examples are given by taking the technical scheme of the invention as a premise, and detailed implementation modes and specific operation processes are given, but the protection scope of the patent of the invention is not limited, and all technical schemes obtained by adopting equivalent substitution or equivalent transformation are within the protection scope of the invention.
As shown in FIG. 3, it can be seen that the reactant gases (hydrogen and oxygen) reach the substrate layer through the bipolar plate flow channels, and the substrate layer is mostly made of porous materials such as carbon paper, and the gas is transported in a direction perpendicular to the plane of the gas diffusion layer due to the influence of pressure difference, and is transported in a direction in the plane of the gas diffusion layer. After the gas reaches the microporous layer, the transmission efficiency of the gas along the in-plane direction is greatly enhanced due to the net-shaped through hole structure formed in the plane and the capillary effect, and the gas tends to be uniformly distributed; in addition, the great increase in the porosity also increases the gas transmission in the direction perpendicular to the gas diffusion layer, which variations certainly contribute to the improvement of the cell performance.
In order to facilitate the performance analysis of the gas diffusion layer, a bubble point method is adopted to measure the aperture (through hole), the principle is that the impregnating solution can be bound in the through hole due to the existence of surface tension, and the impregnating solution in the through hole can be pushed out by increasing the pressure of the gas at one side; and obtaining the pore size distribution information through the relationship between the pressure difference and the pore diameter. Pore size and pressure are related as in the Washburn formula: d=4γcosθ/p, where D is pore diameter, γ is the surface tension of the liquid, θ is contact angle, and p=pressure difference. Thus, the information of the through holes in the gas diffusion layer can be measured, and interference and influence caused by non-through holes are avoided.
In addition, the gas permeability test was performed from the direction perpendicular to the plane of the gas diffusion layer and the direction in the plane of the gas diffusion layer, respectively, and the gas permeation performance through the gas diffusion layer was examined, respectively.
Comparative example
Step 1: dissolving carbon black (65 parts) with the particle size of 25nm and the specific surface area of 120m 2/g in isopropanol, performing ultrasonic treatment to form stable suspension, sequentially adding PTFE emulsion (25 parts) with the solid content of 60% and PVP water-absorbing paste (10 parts) with the viscosity of 1.2 Pa.s, mixing and stirring to obtain microporous layer slurry;
Step 2: uniformly coating the prepared slurry on one side surface (the surface contact angle is 135 ℃) of hydrophobic carbon paper by using a coating machine, and drying at 100 ℃; repeatedly coating and drying for 3 times to prepare a microporous layer with the thickness of 35 mu m;
Step 3, after the drying is finished, placing the material under the protection of nitrogen to perform two-section high-temperature sintering, wherein the temperature of the first section is 250 ℃ and the time is 30min; the second stage is carried out at 350 ℃ for 30min, and the gas diffusion layer for the fuel cell is obtained.
The prepared gas diffusion layer was subjected to performance test, and the test results are shown in table 3.
Example 1
Step 1: dissolving carbon black (60 parts) with the particle size of 25nm and the specific surface area of 120m 2/g in isopropanol, performing ultrasonic treatment to form a stable suspension, sequentially adding PTFE emulsion (25 parts) with the solid content of 60 percent, PLA fiber (5 parts) with the diameter of 0.6 mu m and the length-diameter ratio of 20 and the bending rigidity of 8.5 multiplied by 10 -4cN·cm2 and PVP water absorption paste (10 parts) with the viscosity of 1.2 Pa.s, mixing and stirring to obtain microporous layer slurry;
step 2: uniformly coating the microporous layer slurry prepared in the step 1 on one side surface (the surface contact angle is 135 ℃) of hydrophobic carbon paper by using a coating machine, drying at 100 ℃, and repeatedly coating and drying for 3 times to prepare a microporous layer with the thickness of 36 mu m;
Step 3, after the drying is finished, placing the material under the protection of nitrogen to perform two-section high-temperature sintering, wherein the temperature of the first section is 250 ℃ and the time is 30min; the second stage is carried out at 350 ℃ for 30min, and the gas diffusion layer for the fuel cell is obtained.
The prepared gas diffusion layer was subjected to performance test, and the test results are shown in table 3.
Example 2
Step 1: dissolving carbon nano tube (20 parts) with the particle size of 25nm and the specific surface area of 120m 2/g and carbon black (40 parts) in ethanol, performing ball milling treatment to form stable suspension, sequentially adding PTFE (25 parts) emulsion with the solid content of 55%, PLA fiber (1 part) with the diameter of 0.6 mu m and the length-diameter ratio of 20 and the bending rigidity of 8.5 multiplied by 10 -4cN·cm2 and HPMC water absorption paste (14 parts) with the viscosity of 3.94 Pa.s, mixing and stirring to obtain microporous layer slurry;
step 2: uniformly coating the microporous layer slurry prepared in the step 1 on one side surface (surface contact angle is 138) of hydrophobic carbon paper by using a coating machine, drying at 100 ℃, repeating the step of coating and drying, adding 1 part of PLA in each slurry, reducing 1 part of carbon black for 6 times, and preparing a microporous layer with the thickness of 53 mu m;
Step 3: after the drying is finished, placing the powder under the protection of nitrogen to perform two-section high-temperature sintering, wherein the temperature of the first section is 260 ℃ and the time is 30min; the second stage is carried out at 370 ℃ for 30min, and the gas diffusion layer for the fuel cell is obtained.
The prepared gas diffusion layer was subjected to performance test, and the test results are shown in table 3.
Examples 3 to 7
The procedure was followed as in example 1, with the different performance parameters listed in Table 1 and the different preparation schemes listed in Table 2.
TABLE 1 parameter Table for gas diffusion layers
Table 2 microporous layer preparation protocol table
| Coating mode | Number of coating layers | Drying temperature (DEG C) | Sintering atmosphere, temperature (. Degree. C.) | |
| Comparative example | Coating machine | 3 | 100 | Nitrogen, 250, 350 |
| Example 1 | Coating machine | 3 | 100 | Nitrogen, 250, 350 |
| Example 2 | Coating machine | 6 | 50 | Nitrogen, 260, 370 |
| Example 3 | Spray gun | 2 | 120 | Air, 210, 330 |
| Example 4 | Coating machine | 10 | 80 | Oxygen, 260, 380 |
| Example 5 | Scraper knife | 1 | 80 | Helium, 245, 365 |
| Example 6 | Scraper knife | 6 | 100 | Argon, 250, 350 |
| Example 7 | Spray gun | 2 | 70 | Air, 230, 340 |
TABLE 3 gas diffusion layer Performance test Table
As can be seen from Table 3, the comparative example has substantially the same parameters as in example 1, but the microporous layer has a small difference in thickness after the addition of the pore-increasing fibers, and the average through-hole diameter is significantly increased, and the ventilation in the vertical and in-plane directions is significantly improved. In other examples, although different slurry ratios and preparation methods are adopted, the average through pore diameter is more than 0.5 μm, and the ventilation in the vertical and in-plane directions is relatively large.
The gas diffusion layers prepared in example 1 and comparative example were further hot-pressed to prepare a film-forming electrode, wherein a cell performance test (reaction area 5cm 2) was performed using the same proton exchange membrane and catalyst loading, a reaction gas relative humidity of 100%, and a polarization curve test result was shown in fig. 4. It can be seen that the maximum output power in example 1 can reach 1480mW/cm 2 under high humidity conditions, while the maximum output power in comparative example is only 1250mW/cm 2, and the voltage drop trend in comparative example is more remarkable, the voltage drop slope in example 1 is smaller, and the limiting current density (at 0.3V) reaches 4400mA/cm 2, which is significantly better than 3900mA/cm 2 in comparative example. This reflects that example 1 uses the degradable fiber as the pore-forming agent, and the mass transfer of the reaction gas is more sufficient and more uniformly distributed while the through holes are increased, so that the reaction efficiency is high, the drainage effect is remarkable, and the flooding situation is effectively prevented.
Claims (9)
1. A novel gas diffusion layer for a fuel cell, characterized in that: the microporous layer is prepared by coating a sizing agent containing easily degradable fibers on one side of the surface of the substrate layer; adding degradable fiber as hole-increasing fiber, and forming through holes after high-temperature sintering and decomposition;
The easily degradable fiber is protein fiber, cellulose fiber, chitin fiber, polyvinyl alcohol fiber, polyhydroxyalkanoate fiber or polylactic acid fiber; the diameter of the degradable fiber is 0.05-2 mu m, the length-diameter ratio is more than or equal to 5, and the bending rigidity is more than or equal to 5 multiplied by 10 -4cN·cm2.
2. A method of preparing the novel gas diffusion layer for a fuel cell of claim 1, characterized by: the method comprises the following steps:
Step 1: dissolving carbon powder particles in a solvent under the actions of ultrasonic, ball milling, yarn milling or high-speed shearing to form a stable suspension, sequentially adding a hydrophobic agent emulsion, a pore-increasing fiber and a thickening adhesive, and mixing and stirring to obtain microporous layer slurry;
Step 2: uniformly coating the microporous layer slurry prepared in the step 1 on one side surface of a substrate layer, and drying to prepare a microporous layer;
Step 3: and after the drying is finished, sintering the material in a protective atmosphere to obtain the gas diffusion layer for the fuel cell.
3. The method for producing a novel gas diffusion layer for a fuel cell according to claim 2, characterized in that: the microporous layer slurry comprises the following components in percentage by mass: 50-70% of carbon powder particles, 15-30% of hydrophobic agent emulsion, 0.5-12% of pore-increasing fibers and 5-20% of thickening adhesive.
4. The method for producing a novel gas diffusion layer for a fuel cell according to claim 2, characterized in that: the carbon powder particles are one or more of carbon black, activated carbon, carbon nano tubes, flexible graphite, graphene and carbon fiber powder; the hydrophobic agent emulsion is one of polytetrafluoroethylene, perfluoroethylene propylene, ethylene tetrafluoroethylene copolymer and polyvinylidene fluoride homopolymer; the pore-increasing fiber is a short-cut fiber which is easy to degrade and comprises protein fiber, cellulose fiber, chitin fiber, polyvinyl alcohol fiber, polyhydroxyalkanoate fiber and polylactic acid fiber; the thickening adhesive is a pasty material formed by adsorbing water by a high molecular polymer, and comprises carboxymethyl cellulose, hydroxypropyl methyl cellulose, sodium carboxymethyl cellulose, methyl cellulose, sodium polyacrylate, polyacrylamide, polyethylene oxide, polyvinylpyrrolidone, starch, agar, gelatin and dextrin; the solvent is one or more of methanol, ethanol, isopropanol, n-butanol, ethylene glycol, glycerol and water.
5. The method for producing a novel gas diffusion layer for a fuel cell according to claim 2, characterized in that: the particle diameter of the carbon powder particles is 5 nm-200 nm, and the specific surface area is 50-800 m 2/g; the solid content of the hydrophobe emulsion is more than or equal to 40%; the diameter of the hole-increasing fiber is 0.05-2 mu m, the length-diameter ratio is more than or equal to 5, and the bending rigidity is more than or equal to 5 multiplied by 10 -4cN·cm2; the viscosity of the thickened binder is 0.2 pa.s to 20 pa.s.
6. The method for producing a novel gas diffusion layer for a fuel cell according to claim 2, characterized in that: the substrate layer is carbon paper, woven carbon cloth or non-woven carbon cloth; the basal layer is subjected to hydrophobic treatment, and the surface contact angle is more than or equal to 135 degrees.
7. The method for producing a novel gas diffusion layer for a fuel cell according to claim 2, characterized in that: the slurry coating mode is one of a coating machine, a spray gun and a scraper; the number of coating layers is 1-10; the drying temperature is 50-120 ℃; the thickness of the microporous layer is 10-80 μm.
8. The method for producing a novel gas diffusion layer for a fuel cell according to claim 2, characterized in that: the protective atmosphere in the sintering process is one of air, nitrogen, oxygen, argon and helium; the sintering temperature adopts two-section sintering, and the first section: the sintering temperature is 210-260 ℃ and the sintering time is 30min; and a second section: the sintering temperature is 330-380 ℃ and the sintering time is 30min.
9. Use of a novel gas diffusion layer for a fuel cell according to claim 1 for the preparation of a fuel cell.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006294559A (en) * | 2005-04-14 | 2006-10-26 | Aisin Chem Co Ltd | Water repellent paste, fuel cell gas diffusion layer, and manufacturing method of the fuel dell gas diffusion layer |
| JP2007311269A (en) * | 2006-05-22 | 2007-11-29 | Toyota Motor Corp | Diffusion layer for fuel cell, its manufacturing method, membrane-electrode assembly for fuel cell, and fuel cell |
| DE102007025207A1 (en) * | 2007-05-30 | 2008-12-04 | Volkswagen Ag | Gas diffusion electrode for high temperature gas cells based on electrolyte-impregnated membrane, comprises gas diffusion layer, and porous catalyst layer arranged on diffusion layer and having conductive substrate and catalytic material |
| JP2019009140A (en) * | 2013-11-06 | 2019-01-17 | 東レ株式会社 | Gas diffusion electrode base material and manufacturing method for gas diffusion electrode |
| CN111194497A (en) * | 2017-11-29 | 2020-05-22 | 东丽株式会社 | Microporous layer, method for producing same, gas diffusion electrode substrate, and fuel cell |
| CN111509252A (en) * | 2020-05-06 | 2020-08-07 | 一汽解放汽车有限公司 | Gas diffusion layer and preparation method and application thereof |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006294559A (en) * | 2005-04-14 | 2006-10-26 | Aisin Chem Co Ltd | Water repellent paste, fuel cell gas diffusion layer, and manufacturing method of the fuel dell gas diffusion layer |
| JP2007311269A (en) * | 2006-05-22 | 2007-11-29 | Toyota Motor Corp | Diffusion layer for fuel cell, its manufacturing method, membrane-electrode assembly for fuel cell, and fuel cell |
| DE102007025207A1 (en) * | 2007-05-30 | 2008-12-04 | Volkswagen Ag | Gas diffusion electrode for high temperature gas cells based on electrolyte-impregnated membrane, comprises gas diffusion layer, and porous catalyst layer arranged on diffusion layer and having conductive substrate and catalytic material |
| JP2019009140A (en) * | 2013-11-06 | 2019-01-17 | 東レ株式会社 | Gas diffusion electrode base material and manufacturing method for gas diffusion electrode |
| CN111194497A (en) * | 2017-11-29 | 2020-05-22 | 东丽株式会社 | Microporous layer, method for producing same, gas diffusion electrode substrate, and fuel cell |
| CN111509252A (en) * | 2020-05-06 | 2020-08-07 | 一汽解放汽车有限公司 | Gas diffusion layer and preparation method and application thereof |
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