Tungsten copper modified carbon paper for fuel cell and manufacturing method of tungsten copper modified carbon paper

Abstract

The invention discloses tungsten copper modified carbon paper for a fuel cell and a manufacturing method thereof.The carbon paper comprises a carbon paper precursor, tungsten copper powder and salt, and the carbon paper precursor, the tungsten copper powder and the salt are sintered according to a preset proportion to form a tungsten copper alloy plated carbon paper precursor; and dipping, drying, hot-pressing, carbonizing and graphitizing the carbon paper precursor plated with the tungsten-copper alloy to obtain the tungsten-copper modified carbon paper for the fuel cell. The carbon paper precursor plated with tungsten copper alloy is prepared by matching the carbon paper precursor, tungsten copper powder and salt, and the carbon paper is manufactured by using the carbon paper precursor plated with tungsten copper, so that the conductivity of the carbon paper is improved, and meanwhile, the mechanical strength and the air permeability of the carbon paper are improved.

Description

Technical Field

[0001] The invention relates to the technical field of processing key supporting materials for fuel cells, and in particular to a tungsten-copper modified carbon paper for fuel cells and a manufacturing method thereof. Background Art

[0002] Proton exchange membrane fuel cells use hydrogen as fuel and convert the chemical energy of the fuel into electrical energy through hydrogen oxidation. It is an energy conversion device. It has the advantages of high energy conversion efficiency, long-term continuous power supply, low pollution and noise, stability and reliability, and has huge market potential in the fields of new energy vehicles, military spacecraft, submarine power supplies, etc.

[0003] Carbon paper is the main material of the gas diffusion layer of proton exchange membrane fuel cells. It plays the role of transporting reaction gases, discharging product water, supporting the catalyst layer, collecting current, etc., and realizes the redistribution of product water and reaction gases. It is one of the key components that affect electrode performance. Carbon paper needs to have the following properties in proton exchange membrane fuel cells: (1) Certain strength. It needs to have high mechanical strength and appropriate flexibility to provide structural support for the fuel cell. (2) Appropriate pore size structure. It is used for gas transport during fuel cell operation and the discharge of water after electrochemical reaction to ensure the smooth progress of electrochemical reaction. (3) Low resistivity. It is conducive to electron transport in carbon paper, reduces the contact resistance between carbon paper and other components, and ensures the output power of the fuel cell. (4) Appropriate thickness and apparent density. Improve the ability of carbon paper to transport gas and water.

[0004] At present, there are many patents related to the preparation of carbon paper. For example, patents CN100336972C and CN1331261C use carbon fiber and adhesive to make base paper, and then make carbon paper through thermosetting resin impregnation, hot pressing and graphitization. The carbon material can be transformed from a disordered chaotic layer structure to graphitization through high-temperature heat treatment at 2200℃-2800℃. The higher the temperature and the longer the insulation time, the higher the degree of graphitization. Most of these patents focus on the optimization of the preparation process, and few are modified by doping. However, since the resin is hard carbon, it is difficult to achieve a low resistivity even with high-temperature graphitization treatment. Summary of the invention

[0005] In view of the problems existing in the prior art, the object of the present invention is to provide a tungsten-copper modified carbon paper for fuel cells having good electrical conductivity, air permeability and high mechanical strength and a method for manufacturing the same.

[0006] To achieve the above-mentioned purpose, the first aspect of the present invention provides a tungsten-copper modified carbon paper for fuel cells, comprising a carbon paper precursor, tungsten-copper powder and salt. The carbon paper precursor, tungsten-copper powder and salt in a preset proportion are sintered to form a tungsten-copper alloy-plated carbon paper precursor, and the tungsten-copper alloy-plated carbon paper precursor is subjected to impregnation, drying, hot pressing, carbonization and graphitization to obtain a tungsten-copper modified carbon paper for fuel cells.

[0007] Furthermore, the molar ratio of the carbon paper precursor, tungsten copper powder and salt is 1:5-10:10-20.

[0008] Furthermore, the salt is one or more of sodium chloride, potassium chloride and barium chloride.

[0009] Furthermore, the mass ratio of the components in the tungsten copper powder is 80-95 tungsten: 20-5 copper.

[0010] Furthermore, the tungsten copper powder is an alloy powder with a tungsten-coated copper structure, and the particle size of the alloy powder is less than 10 microns.

[0011] A second aspect of the present invention provides a method for manufacturing tungsten-copper modified carbon paper for fuel cells, comprising the following steps:

[0012] 1) Pre-treating the carbon paper precursor before plating, and burying the pre-treated carbon paper precursor with salt and tungsten copper powder in a preset ratio, sintering at 1000-1200° C. and keeping warm for 2-4 hours, and then naturally cooling to room temperature, and then removing the salt residue by ultrasonic heating and vibration cleaning in distilled water to obtain a carbon paper precursor plated with tungsten copper alloy;

[0013] 2) impregnating the carbon paper precursor coated with tungsten copper alloy in an impregnation solution;

[0014] 3) drying the impregnated carbon paper precursor;

[0015] 4) The dried carbon paper precursor is clamped in the middle of a graphite plate and placed in a sintering furnace to perform gas hot pressing, carbonization and graphitization treatment in sequence to obtain tungsten-copper modified carbon paper for fuel cells.

[0016] Furthermore, the distilled water in step 1) is boiled distilled water.

[0017] Furthermore, the impregnation solution in step 2) includes 50-75% anhydrous ethanol and 25-50% alcohol-soluble thermosetting resin in weight percentage.

[0018] Furthermore, the alcohol-soluble thermosetting resin includes one or more of phenolic, epoxy, and vinyl ester.

[0019] A third aspect of the present invention provides a tungsten-copper modified carbon paper for a fuel cell, which is produced by the above-mentioned manufacturing method.

[0020] A fourth aspect of the present invention provides a fuel cell, comprising the above-mentioned tungsten-copper modified carbon paper for fuel cells.

[0021] The invention prepares a tungsten-copper alloy-plated carbon paper precursor by mixing a carbon paper precursor, tungsten-copper powder and salt, and uses the tungsten-copper-plated carbon paper precursor to manufacture carbon paper, thereby improving the electrical conductivity of the carbon paper while improving the mechanical strength and air permeability of the carbon paper.

[0022] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a SEM image of the tungsten-copper-coated carbon paper of Example 1 of the present invention;

[0024] Figure 2 for Figure 1 A magnified area of ​​the SEM image of the tungsten-copper-coated carbon paper;

[0025] Figure 3 This is the SEM image of the carbon paper of Comparative Example 1;

[0026] Figure 4 Schematic diagram of tensile strength-displacement curves of all embodiments and comparative examples of the present invention. DETAILED DESCRIPTION

[0027] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present invention will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0028] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0029] A first aspect of the present invention provides a tungsten-copper modified carbon paper for a fuel cell, comprising a carbon paper precursor, a tungsten-copper powder and a salt. The carbon paper precursor, the tungsten-copper powder and the salt are sintered in a preset ratio to form a tungsten-copper alloy-plated carbon paper precursor, and the tungsten-copper alloy-plated carbon paper precursor is subjected to impregnation, drying, hot pressing, carbonization and graphitization to obtain a tungsten-copper modified carbon paper for a fuel cell.

[0030] In a preferred embodiment of the present invention, the molar ratio of the carbon paper precursor, tungsten copper powder and salt is 1:5-10:10-20. The carbon paper precursor is carbon fiber felt. In this embodiment, the carbon paper precursor, tungsten copper powder and salt are configured according to the above ratio, which can significantly improve the conductivity, air permeability and mechanical strength of the carbon paper finally obtained, and the comprehensive performance of the carbon paper is higher.

[0031] In a preferred embodiment of the present invention, the salt is one or more of sodium chloride, potassium chloride, and barium chloride.

[0032] In a preferred embodiment of the present invention, the mass ratio of the components in the tungsten copper powder is 80-95 tungsten: 20-5 copper. The above ratio of tungsten copper powder can not only ensure that the conductivity is improved by adding an appropriate amount of copper to the carbon paper, but also enable the tungsten copper alloy powder to react chemically with the carbon fiber at high temperature to generate tungsten carbide, thereby improving the bonding force between the powder and the carbon fiber.

[0033] In a preferred embodiment of the present invention, the tungsten copper powder is an alloy powder with a tungsten-coated copper structure, and the particle size of the alloy powder is less than 10 microns. The tungsten copper powder adopts a tungsten-coated copper structure to protect copper from corrosion and improve durability.

[0034] A second aspect of the present invention provides a method for manufacturing tungsten-copper modified carbon paper for fuel cells, comprising the following steps:

[0035] 1) Pre-treating the carbon paper precursor before plating, and burying the pre-treated carbon paper precursor with salt and tungsten copper powder in a preset ratio, sintering at 1000-1200° C. and keeping warm for 2-4 hours, and then naturally cooling to room temperature, and then removing the salt residue by ultrasonic heating and vibration cleaning in distilled water to obtain a carbon paper precursor plated with tungsten copper alloy;

[0036] 2) impregnating the carbon paper precursor coated with tungsten copper alloy in an impregnation solution;

[0037] 3) drying the impregnated carbon paper precursor;

[0038] 4) The dried carbon paper precursor is clamped in the middle of a graphite plate and placed in a sintering furnace to perform gas hot pressing, carbonization and graphitization treatment in sequence to obtain tungsten-copper modified carbon paper for fuel cells.

[0039] In order to make those skilled in the art more clearly understand the method for manufacturing the tungsten-copper modified fuel cell carbon paper of the present invention, several specific embodiments are listed to specifically introduce the method for manufacturing the carbon paper as follows:

[0040] Embodiment 1:

[0041] 1. Tungsten copper plating: The carbon paper precursor is pre-treated before plating (degreasing, roughening, activation, sensitization), and then the pre-treated carbon paper precursor is placed in a ceramic crucible containing chloride-based salt and tungsten copper alloy powder, and the carbon paper precursor is buried with chloride-based salt and tungsten-5wt.% copper powder. The molar ratio of carbon paper precursor, tungsten copper powder and salt is 1:5:10. Finally, the crucible containing the sample is placed in a vacuum sintering furnace, kept at 1000℃ for 4 hours, and then naturally cooled to room temperature. The sample is placed in boiling distilled water and ultrasonically heated and vibrated for 30 minutes to remove the salt residue, and the carbon paper precursor plated with tungsten copper alloy powder is obtained.

[0042] 2. Impregnation: Prepare an impregnation solution by mixing 75% anhydrous ethanol and 25% alcohol-soluble thermosetting resin by weight. Add a magnetic stirrer rotor, stir the mixture magnetically to mix them thoroughly, and then add the tungsten-copper-plated carbon paper precursor for impregnation for 5 minutes.

[0043] 3. Drying: Place the impregnated carbon paper precursor in an oven at 100°C and dry for 10 minutes.

[0044] 4. Gas hot pressing, carbonization, and graphitization: Place the dried sample in step 3 between two graphite plates and then place it in the furnace chamber of a high-temperature gas pressure sintering furnace. Close the furnace chamber and evacuate the chamber until the vacuum degree is less than 10 -2 pa, and then fill with high-purity inert gas (≥99.99%) to make the test furnace chamber pressure 1MPa, then start the temperature increase program, rise to 160°C at 40°C / minute, and keep warm for 10 minutes for gas hot pressing. After the hot pressing is completed, release the gas to keep the furnace chamber pressure slightly positive, and at the same time, raise the temperature to 1200°C at 20°C / minute, keep warm for 60 minutes, and carbonize. Then raise the temperature to 2000°C at 10°C / minute, keep warm for 30 minutes for graphitization. After the high-temperature furnace is cooled to room temperature, take out the sample, and you will get a tungsten-copper modified carbon paper for fuel cells.

[0045] The obtained carbon paper for proton exchange membrane fuel cell with thickness of 0.2 mm and air permeability of 1500 mL·mm / cm 2 ·h·mmHg, tensile strength 20.5MPa, plane resistivity 4.5mΩ.cm. The carbon paper precursor, tungsten copper powder, salt ratio and subsequent hot pressing, carbonization and lithotripsy process parameters used in this embodiment and Example 2 are slightly different, but the conductivity, mechanical strength and air permeability of the prepared carbon paper are significantly improved compared with the carbon paper without tungsten copper plating in the comparative example.

[0046] Embodiment 2:

[0047] 1. Tungsten copper plating: The carbon paper precursor is pre-treated before plating (degreasing, roughening, activation, sensitization), and then the pre-treated carbon paper precursor is placed in a ceramic crucible containing chloride-based salt and tungsten copper alloy powder, and the carbon paper precursor is buried with chloride-based salt and tungsten-20wt.% copper powder. The molar ratio of carbon paper precursor, tungsten copper powder and salt is 1:7:15. Finally, the crucible containing the sample is placed in a vacuum sintering furnace, and after being kept at 1100°C for 3 hours, it is naturally cooled to room temperature, and the sample is placed in boiling distilled water and ultrasonically heated and vibrated for 30 minutes to remove the salt residue, and a carbon paper precursor plated with tungsten copper alloy powder is obtained. Among them, the distilled water is preferably boiled distilled water to improve the cleaning effect and efficiency. The carbon paper precursor is pre-treated with molten salt tungsten copper plating, and the tungsten copper alloy powder is an ultrafine powder of tungsten-copper structure prepared by wet chemical method. Compared with pure tungsten, tungsten-copper alloy powder has better conductivity; compared with pure copper, tungsten-copper alloy powder will react chemically with carbon fiber at high temperature to generate tungsten carbide, which improves the bonding strength between powder and carbon fiber. Secondly, the tungsten-copper structure protects copper from corrosion and improves durability.

[0048] 2. Impregnation: Take 65% anhydrous ethanol and 35% alcohol-soluble thermosetting resin by weight fraction to prepare an impregnation solution. Add a magnetic stirrer rotor, stir magnetically to mix thoroughly, then add the tungsten-copper-plated carbon paper precursor for impregnation for 5 minutes. The alcohol-soluble thermosetting resin can be one or more of sodium chloride, potassium chloride, and barium chloride.

[0049] 3. Drying: Place the impregnated carbon paper precursor in an oven at 100°C and dry for 10 minutes.

[0050] 4. Gas hot pressing, carbonization, and graphitization: Place the dried sample in step 3 between two graphite plates and then place it in the furnace chamber of a high-temperature gas pressure sintering furnace. Close the furnace chamber and evacuate the chamber until the vacuum degree is less than 10 -2pa, and then fill with high-purity inert gas (≥99.99%), so that the test furnace chamber pressure is 3MPa, then start the temperature increase program, rise to 170℃ at 40℃ / min, and keep warm for 5 minutes for gas hot pressing. After the hot pressing is completed, release the gas to keep the furnace chamber pressure slightly positive, and at the same time, raise the temperature to 1300℃ at 20℃ / min, keep warm for 45 minutes, and carbonize. Then raise the temperature to 2200℃ at 10℃ / min, keep warm for 20 minutes for graphitization. After the high-temperature furnace is cooled to room temperature, take out the sample, and a tungsten-copper modified carbon paper for fuel cells is obtained. Hot pressing, carbonization and graphitization adopt an integrated preparation process, which simplifies the preparation steps; and a high-temperature gas pressure sintering furnace is used to replace the hot press, carbonization furnace and graphitization furnace, saving equipment costs; finally, keep the furnace chamber slightly positive, which can prevent the carbon paper from curling and bubbling due to uneven stress distribution during the sintering process, thereby improving the product yield. By using gas pressurization, the pressure in all directions can be kept equal to ensure the consistency of the product.

[0051] pass Figure 1 and Figure 2 The SEM image shows that the tungsten copper alloy powder is well attached to the carbon fiber, which improves the conductivity of the carbon fiber. The tungsten copper modified proton exchange membrane fuel cell carbon paper with a thickness of 0.19 mm was obtained, and its air permeability was 2000 mL·mm / cm 2 ·h·mmHg, tensile strength 26.8MPa, plane resistivity 4mΩ.cm. Compared with the carbon paper without tungsten copper plating in the comparative example, the performance is significantly improved.

[0052] Embodiment 3:

[0053] 1. Tungsten copper plating: The carbon paper precursor is pre-treated before plating (degreasing, roughening, activation, sensitization), and then the pre-treated carbon paper precursor is placed in a ceramic crucible containing chloride-based salt and tungsten copper alloy powder, and the carbon paper precursor is buried with chloride-based salt and tungsten-10wt.% copper powder. The molar ratio of carbon paper precursor, tungsten copper powder and salt is 1:10:10. Finally, the crucible containing the sample is placed in a vacuum sintering furnace, kept at 1200℃ for 2 hours, and naturally cooled to room temperature. The sample is placed in boiling distilled water and ultrasonically heated and vibrated for 30 minutes to remove the salt residue, and the carbon paper precursor plated with tungsten copper alloy powder is obtained.

[0054] 2. Impregnation: Take 50% anhydrous ethanol and 50% alcohol-soluble thermosetting resin by weight to prepare an impregnation solution. Add a magnetic stirrer rotor, stir magnetically to mix thoroughly, then add the tungsten-copper-plated carbon paper precursor for impregnation for 5 minutes.

[0055] 3. Drying: Place the impregnated carbon paper precursor in an oven at 100°C and dry for 10 minutes.

[0056] 4. Gas hot pressing, carbonization, and graphitization: Place the dried sample in step 3 between two graphite plates and then place it in the furnace chamber of a high-temperature gas pressure sintering furnace. Close the furnace chamber and evacuate the chamber until the vacuum degree is less than 10 -2 pa, and then fill with high-purity inert gas (≥99.99%) to make the test furnace chamber pressure 5MPa, then start the temperature increase program, rise to 180℃ at 40℃ / min, and keep warm for 5 minutes for gas hot pressing. After the hot pressing is completed, release the gas to keep the furnace chamber pressure slightly positive, and at the same time, raise the temperature to 1500℃ at 20℃ / min, keep warm for 30 minutes, and carbonize. Then raise the temperature to 2400℃ at 10℃ / min, keep warm for 10 minutes for graphitization. After the high-temperature furnace is cooled to room temperature, take out the sample, and you will get a tungsten-copper modified carbon paper for fuel cells.

[0057] The obtained carbon paper for proton exchange membrane fuel cell with thickness of 0.18 mm and air permeability of 1700 mL·mm / cm 2 ·h·mmHg, tensile strength 25.3MPa, plane resistivity 8.5mΩ.cm. Compared with the carbon paper without tungsten copper plating in the comparative example, the performance is significantly improved.

[0058] Comparative Example:

[0059] 1. Impregnation: Prepare an impregnation solution by mixing 75% anhydrous ethanol and 25% alcohol-soluble thermosetting resin by weight. Add a magnetic stirrer rotor, stir the mixture magnetically to mix the mixture thoroughly, and then add the tungsten-copper-plated carbon paper precursor for impregnation for 5 minutes.

[0060] 2. Drying: Place the impregnated carbon paper precursor in an oven at 100°C and dry for 10 minutes.

[0061] 3. Gas hot pressing, carbonization, and graphitization: Place the dried sample in step 2 between two graphite plates, and then place it in the furnace chamber of a high-temperature gas pressure sintering furnace. Close the furnace chamber, evacuate the chamber so that the vacuum degree is less than 10-2pa, and then fill it with high-purity inert gas (≥99.99%) to make the test furnace chamber pressure 2MPa, then start the heating program, raise the temperature to 170°C at 40°C / minute, and keep it warm for 5 minutes for gas hot pressing. After the hot pressing is completed, release the gas to keep the furnace chamber pressure slightly positive, and at the same time, raise the temperature to 1300°C at 20°C / minute, keep it warm for 45 minutes, and carbonize. Then raise the temperature to 2800°C at 10°C / minute, and keep it warm for 10 minutes for graphitization. After the high-temperature furnace cools to room temperature, take out the sample to obtain a tungsten-copper modified carbon paper for fuel cells.

[0062] pass Figure 3From the SEM image, it can be seen that the high temperature graphitization at 2800℃ makes the carbon fiber coated with hard carbon, resulting in fewer air pores, affecting the air permeability and poor surface flatness. The obtained carbon paper for proton exchange membrane fuel cells with a thickness of 0.19mm was tungsten-copper modified, with an air permeability of 800mL·mm / cm2·h·mmHg, a tensile strength of 14.7MPa, and a plane resistivity of 15mΩ.cm. The carbon paper precursor used in the preparation of the comparative carbon paper was not treated with tungsten-copper plating, and the conductivity, air permeability and mechanical strength of the carbon paper were relatively low.

[0063] It can be seen from the above embodiments that the present invention prepares a carbon paper precursor plated with tungsten copper alloy by mixing a carbon paper precursor, tungsten copper powder and salt, and uses the carbon paper precursor plated with tungsten copper to manufacture carbon paper, thereby improving the conductivity of the carbon paper and improving the mechanical strength and air permeability of the carbon paper. It should be noted that the above embodiments listed in the present invention are only for illustration, and the present invention is not limited thereto.

[0064] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0065] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A tungsten-copper modified carbon paper for fuel cells, characterized in that: The invention comprises a carbon paper precursor, tungsten copper powder and salt. The carbon paper precursor, tungsten copper powder and salt in a preset ratio are sintered to form a tungsten copper alloy-plated carbon paper precursor, and the tungsten copper alloy-plated carbon paper precursor is subjected to impregnation, drying, hot pressing, carbonization and graphitization to obtain tungsten copper modified carbon paper for fuel cells.

2. The tungsten-copper modified carbon paper for fuel cells according to claim 1, characterized in that: The molar ratio of the carbon paper precursor, tungsten copper powder and salt is 1:5-10:10-20.

3. The tungsten-copper modified carbon paper for fuel cells according to claim 1, characterized in that: The salt is one or more of sodium chloride, potassium chloride and barium chloride.

4. The tungsten-copper modified carbon paper for fuel cells according to claim 1, characterized in that: The mass ratio of the components in the tungsten copper powder is 80-95 tungsten: 20-5 copper.

5. The tungsten-copper modified carbon paper for fuel cells according to claim 1, characterized in that: The tungsten copper powder is an alloy powder with a tungsten-coated copper structure, and the particle size of the alloy powder is less than 10 microns.

6. A method for manufacturing tungsten-copper modified carbon paper for fuel cells, characterized in that: The steps include: 1) Pre-treating the carbon paper precursor before plating, and burying the pre-treated carbon paper precursor with salt and tungsten copper powder in a preset ratio, sintering at 1000-1200° C. and keeping warm for 2-4 hours, and then naturally cooling to room temperature, and then removing the salt residue by ultrasonic heating and vibration cleaning in distilled water to obtain a carbon paper precursor plated with tungsten copper alloy; 2) impregnating the carbon paper precursor coated with tungsten-copper alloy in an impregnation solution; 3) drying the impregnated carbon paper precursor; 4) The dried carbon paper precursor is clamped in the middle of a graphite plate and placed in a sintering furnace to perform gas hot pressing, carbonization and graphitization treatment in sequence to obtain tungsten-copper modified carbon paper for fuel cells.

7. The manufacturing method according to claim 6, characterized in that: In step 1), the distilled water is boiled distilled water.

8. The manufacturing method according to claim 6, characterized in that: The impregnation liquid in step 2) includes 50-75% anhydrous ethanol and 25-50% alcohol-soluble thermosetting resin in weight percentage.

9. The manufacturing method according to claim 8, characterized in that: The alcohol-soluble thermosetting resin includes one or more of phenolic, epoxy, and vinyl ester.

10. A tungsten-copper modified carbon paper for a fuel cell, characterized in that: The invention is prepared by the manufacturing method according to any one of claims 6 to 9.

11. A fuel cell, characterized in that: It comprises the tungsten-copper modified carbon paper for fuel cells as claimed in claim 10.

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