Conductive carbon paper, and manufacturing method and application thereof

Abstract

To provide a conductive carbon paper that can be used in a fuel cell to enable a membrane electrode of a fuel cell to maintain good conductive stability and power generation performance during power generation, and a method for manufacturing the same.SOLUTION: A conductive carbon paper includes carbon fibers and an adhesive component, and the adhesive component contains an elasticity aid, and when a load of 1 MPa is applied in the thickness direction of the carbon paper, its volume density is 0.30 to 0.40 g / cm3. The conductive carbon paper is produced by producing a carbon fiber base paper containing the elasticity aid, dipping it in a gel liquid, and then drying, solidifying, and carbonizing it.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to the field of fuel cell technology, and in particular to conductive carbon paper and its manufacturing method and application. [Background technology]

[0002] Typically, the basic structure of a polymer electrolyte fuel cell (hereinafter referred to as a fuel cell) consists of a proton exchange membrane, a catalyst, and gas diffusion layers arranged at both the cathode and anode. The gas diffusion substrate functions as a cell reaction field and a current collector. In a typical fuel cell, a waterproof layer is placed between the catalyst and the gas diffusion layer substrate, and a bipolar plate is placed on the opposite side of the gas diffusion layer substrate.

[0003] In the prior art, carbon paper, a gas diffusion layer substrate for fuel cells, is a porous sheet material in which dispersed carbon fibers are bonded with carbide, and carbon paper with different porosities can be designed to improve the breathability and drainage properties of the carbon paper.

[0004] However, currently, the density, strength, and thermal conductivity of porous carbon paper are values ​​measured when the paper is not compressed. In fact, when such porous carbon paper is placed in a fuel cell as a gas diffusion substrate, the porous carbon sheet is compressed. However, since carbon fibers and carbides do not have elasticity when compressed, distortion occurs in the carbon paper during the long-term compression process, leading to problems such as gas leakage, increased resistivity, and reduced power generation performance.

[0005] It is with this in mind that the present invention is particularly proposed. Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide a conductive carbon paper that solves the above problems, and a manufacturing method and application thereof. [Means for solving the problem]

[0007] To achieve the above object, the present invention particularly adopts the following technical solutions.

[0008] According to a first aspect, the present invention provides a conductive carbon paper comprising carbon fibers and an adhesive component, wherein the adhesive component includes an elasticity aid, and when a load of 1 MPa is applied in the thickness direction of the carbon paper, the volume density of the carbon paper is 0.30 to 0.40 g / cm. 3 is.

[0009] According to a second aspect, the present invention further provides a method for producing the conductive carbon paper, Step S1 of producing carbon fiber base paper containing the elasticity aid; Step S2 of dipping the carbon fiber base paper in a gel liquid; Step S3 of drying, solidifying, and carbonizing the carbon fiber base paper after the dipping; and step S4, which is obtained by hydrophobizing the carbonized product.

[0010] According to a third aspect, the present invention further provides an application of said conductive carbon paper in the field of fuel cells. [Effects of the Invention]

[0011] The present invention adds an elasticity aid when manufacturing conductive carbon paper, which allows the carbon paper to have considerable elastic recovery while also allowing the total area of ​​carbon material exposed on the surface of the carbon paper to be sufficiently large when the carbon paper is compressed, thereby reducing the resistivity through the thickness direction. At the same time, the gas permeability and gas diffusivity are relatively high even when compressed for a long period of time. This solves the technical problem of carbon paper having relatively high resistivity when compressed and being difficult to recover after compression, allowing fuel cell membrane electrodes to maintain long-term conductive stability during power generation. DETAILED DESCRIPTION OF THE INVENTION

[0012] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present invention, the following clearly and completely describes the technical solutions in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without any creative efforts fall within the protection scope of the present invention.

[0013] When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or range defined by a series of upper and lower preferred values, it should be understood to specifically disclose all ranges formed by any pairing of any range upper or preferred value with any range lower or preferred value, whether or not the ranges are individually disclosed. For example, if a range "1 to 5" is disclosed, the stated range should be interpreted to include the ranges "1 to 4," "1 to 3," "1 to 2," "1 to 2 and 4 to 5," "1 to 3 and 5," etc. When a range of numerical values ​​is described herein, unless otherwise stated, it is intended that the range include the endpoints thereof, and all integers and fractions within the range.

[0014] In these examples, unless otherwise specified, all parts and percentages are calculated by weight. The raw material blend ratios not specified in the present invention can be blended and mixed in any ratio.

[0015] "And / or" is used to indicate that either or both of the stated situations may occur; for example, A and / or B includes (A and B) and (A or B).

[0016] The conductive carbon paper of the present invention includes the carbon fiber and an adhesive component, and the adhesive component includes an elasticity aid. When a load of 1 MPa is applied in the thickness direction of the carbon paper, the volume density of the carbon paper is 0.30 to 0.40 g / cm. 3 is.

[0017] The volume density of the carbon paper when a load of 1 MPa is applied in the thickness direction of the carbon paper is 0.30 to 0.40 g / cm 3 In this case, the gas permeability and gas diffusivity of the carbon fiber sheet are increased.

[0018] When a load of 1 MPa is applied in the thickness direction of the carbon paper, the volume density of the carbon fiber is 0.30 g / cm 3 If the thickness is smaller than 1 / 2 mm, the total area of ​​the carbon fibers exposed on the surface of the carbon fiber sheet when a load is applied will be small, resulting in a large contact resistance when the gas diffusion substrate is brought into contact with components such as a bipolar plate or a catalyst layer.

[0019] When a load of 1 MPa is applied in the thickness direction of the carbon paper, the volume density of the carbon fiber is 0.40 g / cm 3 If the temperature exceeds this range, the gas permeability of the carbon fiber sheet decreases.

[0020] In the gas diffusion substrate of the present invention, the resistance value of the carbon paper when a load of 1 MPa is applied in the thickness direction of the carbon paper is 2 to 10 mΩ·cm 2 It is preferable that:

[0021] In some embodiments, the elasticity aid comprises 0.2 to 10 wt % modified helical carbon nanotubes and / or modified helical carbon fibers.

[0022] Furthermore, in some preferred embodiments, the modified helical carbon nanotube has a length of 30 to 100 μm and a diameter of 10 to 20 nm; Furthermore, in some preferred embodiments, the modified helical carbon fiber has a length of 50 to 6000 μm and a diameter of 50 nm to 10000 nm.

[0023] When the content of the modified helical carbon nanotubes and / or modified helical carbon fibers is 0.2 to 10 wt%, the modified helical carbon nanotubes and / or modified helical carbon fibers have elasticity, which allows the total area of ​​the carbon material exposed on the surface of the carbon paper to be sufficiently large when the carbon paper is compressed, thereby reducing the contact resistance when the gas diffusion substrate is brought into contact with components such as a bipolar plate or a catalyst layer.

[0024] When the content of modified helical carbon nanotubes and / or modified helical carbon fibers is less than 0.2 wt%, the elastic recovery force of the modified helical carbon nanotubes and / or modified helical carbon fibers is relatively small, so the impact on the contact resistance during compression and the recovery force after long-term compression is relatively small.

[0025] If the content of modified helical carbon nanotubes and / or modified helical carbon fibers exceeds 10 wt%, when the carbon paper is compressed, too much modified helical carbon nanotubes and / or modified helical carbon fibers will be exposed on the surface of the carbon fiber sheet, which will be prone to falling off and pollute the environment.

[0026] The method for producing the conductive carbon paper of the present invention includes the following steps:

[0027] In S1, carbon fiber base paper containing the elasticity aid is produced.

[0028] In some embodiments, the carbon fiber base paper is produced by adding carbon fibers, an elasticity aid, and a dispersant to water, dispersing them uniformly to obtain a suspension, and then producing the carbon fiber base paper using a conventional papermaking method.

[0029] In some embodiments, the mass concentration of the carbon fibers is 0.05 to 0.5 wt %.

[0030] In some embodiments, the mass concentration of the dispersing agent is 0.01 to 1 wt %, and the dispersing agent includes one or more of sodium polyacrylate, sodium dodecylbenzenesulfonate, polyoxyethyleneamine, polyacrylamide, polyvinyl alcohol, polyethylene glycol, polyoxyethylene, carboxymethylcellulose, hydroxyethylcellulose, or chitosan, etc.

[0031] In some embodiments, the elasticity aid comprises modified helical carbon nanotubes and / or modified helical carbon fibers.

[0032] In some preferred embodiments, the mass concentration of the elasticity aid is 0.2 to 10 wt %.

[0033] Furthermore, the modified helical carbon nanotube has a length of 30 to 100 μm and a diameter of 10 to 20 nm; Furthermore, the modified helical carbon fiber has a length of 50 to 6000 μm and a diameter of 50 nm to 10000 nm.

[0034] Furthermore, the modified helical carbon nanotube or modified helical carbon fiber is obtained by heat treating the helical carbon nanotube or helical carbon fiber in an oxygen-containing atmosphere at 150 to 400°C for 1 to 60 minutes. The oxygen-containing atmosphere includes air or other oxygen-containing atmospheres.

[0035] The heat treatment in the oxygen-containing atmosphere can remove substances such as moisture and organic contaminants. If the heat treatment temperature is lower than 150°C, the required heat treatment time will be long, increasing production costs. If the heat treatment temperature is higher than 400°C, the helical carbon nanotubes or helical carbon fibers will be excessively oxidized, resulting in a decrease in mechanical properties.

[0036] In S2, the carbon fiber base paper is dipped in a gel liquid.

[0037] In some embodiments, the gel liquid is a solution of an adhesive resin, and the mass concentration of the adhesive resin solution is 0.5 to 30 wt %.

[0038] In S3, the dipped carbon fiber base paper is dried, solidified, and carbonized.

[0039] In some embodiments, the solidification is performed by pressing the dried carbon fiber base paper at 150 to 250°C and 0.1 to 5 MPa.

[0040] In some embodiments, the carbonization temperature is 1200 to 2300° C., and the carbonization time is 2 to 30 minutes.

[0041] In S4, the conductive carbon paper obtained by hydrophobizing the carbonized product can be used as a gas diffusion layer substrate for a fuel cell membrane electrode.

[0042] In some embodiments, the hydrophobization is achieved by thoroughly contacting the carbonized product with a solution, dispersion, or suspension of a hydrophobic material, followed by drying and heat treatment.

[0043] In some preferred embodiments, the hydrophobic material comprises a fluorine-containing resin.

[0044] In some more preferred embodiments, the hydrophobic material comprises one or more of polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), or tetrafluoroethylene-ethylene copolymer (ETFE).

[0045] The present invention further provides an application of the conductive carbon paper in the field of fuel cells.

[0046] The carbide-based phase of the present invention, and the carbon fiber and elastic component contained in this phase, provide a stable conductive path. Furthermore, the presence of the elastic component in the material provides the gas diffusion layer substrate with elasticity, improving dimensional adaptability when compression-bonded with the proton exchange membrane layer or catalyst layer during fuel cell fabrication. Even after prolonged compression, the conductive performance does not significantly decrease, and the battery maintains stable power generation performance.

[0047] The carbon paper manufactured in the examples of the present invention was tested, including a thickness resistivity test, a change rate of the thickness resistivity of the carbon paper due to long-term compression, an air permeability test, and a power generation performance test of the membrane electrode.

[0048] Carbon paper surface morphology: Visually inspect the carbon paper for uniformity.

[0049] Through-thickness resistivity test method: The carbon paper was sandwiched between two gold-plated copper electrodes, and a pressure of 1 MPa was applied between the copper electrodes. Then, a current of 10 mA / cm was applied. 2 At this current density, read the voltage drop and calculate the resistivity of the carbon paper in the thickness direction using the following formula: R (Ω cm 2 ) = (voltage drop (V) × sample area (cm 2 )) / Current (A).

[0050] Percent change in resistivity through thickness of carbon paper due to long-term compression: The carbon paper is placed between two gold-plated copper electrodes, and after 5 minutes, the resistivity in the thickness direction is measured at a surface pressure of 1.0 MPa. The surface pressure of 1.0 MPa is then applied for 14,400 minutes, and the resistivity in the thickness direction is measured after the pressure is continued. The rate of change in resistivity in the thickness direction due to long-term compression is calculated as follows: Resistivity change rate (%) through thickness due to long-term compression = [resistivity in the thickness direction when pressure is applied for 5 minutes (Ω cm 2 ) - Resistivity through the thickness (Ω cm) when pressure is applied for 14,400 minutes 2 )] / resistivity in the thickness direction when pressure is applied for 5 minutes (Ω cm 2 ).

[0051] Air permeability test method: The carbon paper is clamped with a special tool and attached to the air permeability measuring device. Then, 200 mL of air is poured into the carbon paper in the thickness direction, and the gas permeability (mL / hr / cm 2 / mmAq) is calculated.

[0052] Membrane electrode power generation performance test: The cells were tested at a fuel cell testing station (Changsha Blue Membrane Technology Co., Ltd.). Under different humidity conditions, the cells were discharged under constant voltage conditions, and the corresponding current decay was measured to obtain the decay status of the membrane electrode performance, i.e., the current density-voltage polarization curve and power density curve.

[0053] The test steps are as follows: The operating temperature of the fuel cell is fixed at 80°C and the relative humidity (RH) is 20%, and humidified pure hydrogen gas and pure oxygen gas are supplied to the anode and cathode at 200 mL / min, respectively. A back pressure of 55 kPa is applied to the exhaust ports on both sides. Before the cell test, the membrane electrode is first activated for 30 minutes at a constant voltage of 0.6 V under fully humidified conditions (100% RH) until the cell current density stabilizes. A polarization curve is measured using a scan voltage of 1.0 V to 0.2 V at 20 mV s-1 per step.

[0054] The power generation performance that can be evaluated from the obtained polarization curve is as follows. Current density ≧2.5A / cm 2 If @0.6V, it is considered good and is indicated by the symbol ◎. Current density ≧1.5A / cm 2 @0.6V, while current density <2.5A / cm 2 In the case of @0.6V, it is still considered good and is indicated by the symbol △. Current density<1.5A / cm 2 If it is @0.6V, it is considered bad and is indicated by the symbol X.

[0055] Example 1 According to the manufacturing method provided in the present invention, the conductive carbon paper is manufactured and its performance is tested. The specific steps are as follows:

[0056] (1) Commercially available helical carbon nanotubes are heat-treated in air at 180°C for 20 minutes to obtain modified helical carbon nanotubes, which have a length of 30 to 100µm and a diameter of 10 to 20nm.

[0057] (2) Approximately 1 g of carbon fiber, 10 g of the modified helical carbon nanotubes obtained in step (1), and 1 g of polyvinyl alcohol are placed in 1000 mL of deionized water, uniformly dispersed to obtain a suspension, and carbon fiber base paper is produced using a conventional papermaking method.

[0058] (3) An aqueous solution of approximately 10 wt% phenolic resin is placed to form a gel liquid.

[0059] (4) The carbon fiber base paper obtained in step (2) is immersed in the gel solution of step (3) for 30 minutes.

[0060] (5) The carbon fiber base paper obtained in step (4) is dried at 120°C, pressed at 200°C and 0.5 MPa for 10 minutes, and then carbonized at 2000°C for 20 minutes.

[0061] (6) The carbonized product is immersed in a 10% by mass PTFE aqueous solution for 5 minutes, removed, dried, and sintered at 350°C to obtain the conductive carbon paper. The conductive carbon paper contains approximately 1 wt% of modified helical carbon nanotubes, and when a load of 1 MPa is applied in the thickness direction of the carbon paper, the volume density of the carbon paper is 0.33 g / cm. 3 is.

[0062] Two sheets of the conductive carbon paper were placed symmetrically on both sides of the catalyst-coated proton exchange membrane, and the catalyst coating amount on both sides was 0.5 mg / cm. 2 and heat-pressed at 170°C to form a membrane electrode.

[0063] A single cell is assembled by sandwiching the membrane electrode between two graphite bipolar plates with a single serpentine channel and gasketed with polytetrafluoroethylene.

[0064] Finally, the membrane electrode is tested using the test method described above to evaluate its power generation performance.

[0065] The performance test data of the conductive carbon paper and membrane electrode are shown in Table 1.

[0066] Example 2 According to the manufacturing method provided in the present invention, the conductive carbon paper is manufactured and its performance is tested. The specific steps are as follows:

[0067] (1) Commercially available helical carbon nanotubes are heat-treated in air at 200°C for 20 minutes to obtain modified helical carbon nanotubes, which have a length of 30 to 100 µm and a diameter of 10 to 20 nm.

[0068] (2) Approximately 3 g of carbon fiber, 5 g of the modified helical carbon nanotubes obtained in step (1), and 3 g of polyacrylamide are placed in 1000 mL of deionized water, uniformly dispersed to obtain a suspension, and carbon fiber base paper is produced using a conventional papermaking method.

[0069] (3) An aqueous solution of approximately 20 wt% phenolic resin is placed to form a gel liquid.

[0070] (4) The carbon fiber base paper obtained in step (2) is immersed in the gel solution of step (3) for 30 minutes.

[0071] (5) The carbon fiber base paper obtained in step (4) is dried at 120°C, pressed at 150°C and 1 MPa for 10 minutes, and then carbonized at 1800°C for 20 minutes.

[0072] (6) The carbonized product is immersed in an 8% by mass PFA aqueous solution for 5 minutes, taken out, dried, and sintered at 350°C to obtain the conductive carbon paper. The conductive carbon paper contains approximately 0.5 wt% of modified helical carbon nanotubes, and when a load of 1 MPa is applied in the thickness direction of the carbon paper, the volume density of the carbon paper is 0.30 g / cm. 3 is.

[0073] Two sheets of the conductive carbon paper were placed symmetrically on both sides of the catalyst-coated proton exchange membrane, with the catalyst coating amount on both sides being 0.5 mg / cm. 2 and heat-pressed at 170°C to form a membrane electrode.

[0074] A single cell is assembled by sandwiching the membrane electrode between two graphite bipolar plates with a single serpentine channel and gasketed with polytetrafluoroethylene.

[0075] Finally, the membrane electrode is tested using the test method described above to evaluate its power generation performance.

[0076] The performance test data of the conductive carbon paper and membrane electrode are shown in Table 1.

[0077] Example 3 According to the manufacturing method provided in the present invention, the conductive carbon paper is manufactured and its performance is tested. The specific steps are as follows:

[0078] (1) A commercially available spiral carbon fiber is heat-treated with air at 150°C for 20 minutes to obtain a modified spiral carbon fiber, the length of which is 50 to 6000µm and the diameter of which is 50nm to 10000nm.

[0079] (2) Approximately 1 g of carbon fiber, 50 g of the modified spiral carbon fiber obtained in step (1), and 0.5 g of polyvinyl alcohol are placed in 1000 mL of deionized water, uniformly dispersed to obtain a suspension, and carbon fiber base paper is produced using a conventional papermaking method.

[0080] (3) A solution of approximately 1 wt% phenolic resin in methanol is placed to form a gel liquid.

[0081] (4) The carbon fiber base paper obtained in step (2) is immersed in the gel solution of step (3) for 60 minutes.

[0082] (5) The carbon fiber base paper obtained in step (4) is dried at 120°C, pressed at 200°C and 3 MPa for 10 minutes, and then carbonized at 1500°C for 20 minutes.

[0083] (6) The obtained carbon paper is immersed in an aqueous solution of FEP with a mass concentration of 12%, left for 5 minutes, taken out, dried, and further sintered at 350°C to obtain the conductive carbon paper. The conductive carbon paper contains approximately 5 wt% of modified helical carbon fibers, and when a load of 1 MPa is applied in the thickness direction of the carbon paper, the volume density of the carbon paper is 0.34 g / cm. 3 is.

[0084] Two sheets of the conductive carbon paper were placed symmetrically on both sides of the catalyst-coated proton exchange membrane, with the catalyst coating amount on both sides being 0.5 mg / cm. 2 and heat-pressed at 170°C to form a membrane electrode.

[0085] A single cell is assembled by sandwiching the membrane electrode between two graphite bipolar plates with a single serpentine channel and gasketed with polytetrafluoroethylene.

[0086] Finally, the membrane electrode is tested using the test method described above to evaluate its power generation performance.

[0087] The performance test data of the conductive carbon paper and membrane electrode are shown in Table 1.

[0088] (Comparative Example 1) The difference from Example 1 is that no modified helical carbon nanotubes were used when preparing the carbon fiber base paper. The performance test data of the resulting conductive carbon paper and membrane electrode are shown in Table 1.

[0089] (Comparative Example 2) The difference from Example 1 is that the amount of modified helical carbon nanotubes added in step (2) is 1 g, and the content of modified helical carbon nanotubes in the obtained conductive carbon paper is approximately 0.1 wt %. The performance test data of the obtained conductive carbon paper and membrane electrode are shown in Table 1.

[0090] (Comparative Example 3) The difference from Example 1 is that the amount of modified helical carbon nanotubes added in step (2) is 150 g, and the content of modified helical carbon nanotubes in the obtained conductive carbon paper is approximately 15 wt %. The performance test data of the obtained conductive carbon paper and membrane electrode are shown in Table 1.

[0091] Comparative Example 4 The difference from Example 1 is that in step (2), unmodified commercially available helical carbon nanotubes were directly used, and the length of the helical carbon nanotubes was 30-100 μm and the diameter was 10-20 nm. The performance test data of the obtained conductive carbon paper and membrane electrode are shown in Table 1.

[0092] JPEG2025171941000001.jpg49105

[0093] As can be seen from Table 1, Examples 1 to 3 have relatively low resistivities and good, stable membrane electrode power generation performance. Comparative Example 3 has relatively low resistivity, but the amount of modified helical carbon nanotubes added is too high, resulting in too many modified helical carbon nanotubes exposed to the surface of the carbon fiber sheet when the carbon paper is compressed, resulting in obvious carbon particle shedding. Comparative Example 2 has too low an amount of modified helical carbon nanotubes added, resulting in significantly greater variation in resistivity under sustained pressure. Comparative Example 1 does not use modified helical carbon nanotubes, and Comparative Example 4 uses unmodified helical carbon nanotubes; however, the resistivity, conductive stability, and membrane electrode power generation performance are all relatively poor.

[0094] It should be noted that the technical features of the above examples can be combined in any desired manner. For the sake of brevity, not all possible combinations of the technical features in the above examples are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered within the scope of the present specification. The above examples only illustrate some embodiments of the present application, and although the descriptions are relatively specific and detailed, they should not be construed as limitations on the patent scope of the invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and all of these fall within the scope of protection of the present application. Therefore, the scope of protection of the patent of the present application should be governed by the appended claims.

Claims

1. A conductive carbon paper comprising carbon fibers and an adhesive component, wherein the adhesive component contains an elasticity aid; When a load of 1 MPa is applied in the thickness direction of the carbon paper, the volume density of the carbon paper is 0.30 to 0.40 g / cm ３ and The elasticity assistant contains 0.2 to 10 wt % of modified helical carbon nanotubes and / or modified helical carbon fibers, The conductive carbon paper is characterized in that the modified helical carbon nanotubes or modified helical carbon fibers are obtained by heat treating helical carbon nanotubes or helical carbon fibers in an oxygen-containing atmosphere at 150 to 400°C.

2. 2. The conductive carbon paper according to claim 1, wherein the modified helical carbon nanotubes have a length of 30 to 100 μm and a diameter of 10 to 20 nm.

3. 2. The conductive carbon paper according to claim 1, wherein the modified helical carbon fiber has a length of 50 to 6000 μm and a diameter of 50 nm to 10000 nm.

4. Step S1 of producing carbon fiber base paper containing the elasticity aid; Step S2: dipping the carbon fiber base paper in a gel liquid; Step S3 of drying, solidifying, and carbonizing the carbon fiber base paper after the dipping; and step S4 of hydrophobizing the carbonized product, In step S1, producing the carbon fiber base paper is to add carbon fibers, an elasticity aid, and a dispersant to water, uniformly disperse them to obtain a suspension, and produce the carbon fiber base paper by a normal papermaking method; The mass concentration of the carbon fiber is 0.05 to 0.5 wt %, The mass concentration of the dispersant is 0.01 to 1 wt %, The elasticity assistant comprises modified helical carbon nanotubes and / or modified helical carbon fibers, The mass concentration of the elasticity aid is 0.2 to 10 wt %, The method for producing conductive carbon paper according to any one of claims 1 to 3, wherein the modified helical carbon nanotubes or modified helical carbon fibers are obtained by heat treating helical carbon nanotubes or helical carbon fibers in an oxygen-containing atmosphere at 150 to 400°C.

5. In step S2, the gel liquid is a solution of an adhesive resin, 5. The manufacturing method according to claim 4, wherein the mass concentration of the adhesive resin solution is 0.5 to 30 wt %.

6. 6. The manufacturing method according to claim 5, wherein in step S2, the mass concentration of the adhesive resin solution is 0.5 to 20 wt %.

7. In step S3, the solidification refers to pressing the dried carbon fiber base paper at 150 to 250°C and 0.1 to 5 MPa, 5. The method according to claim 4, wherein the carbonization temperature is 1200 to 2300° C., and the carbonization time is 2 to 30 minutes.

8. 5. The method according to claim 4, wherein in step S4, the hydrophobization is performed by sufficiently contacting the carbonized product with a solution or dispersion of a hydrophobic material, followed by drying and heat treatment.

9. The manufacturing method according to claim 8 , wherein in step S4, the hydrophobic material includes a fluorine-containing resin.

10. 10. The manufacturing method of claim 9, wherein in step S4, the hydrophobic material comprises one or more of polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, or tetrafluoroethylene-ethylene copolymer.

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