Continuous preparation method from carbon fiber to carbon paper

Abstract

The invention discloses a continuous preparation method from carbon fibers to carbon paper. The continuous preparation method comprises the steps of carbon fiber dispersion, carbon fiber dehydration forming, carbon felt sizing, carbon felt curing and carbon felt high-temperature treatment. The carbon felt production process and the carbon paper production process are integrated into a continuous production process, carbon fibers are used as raw materials in the process, the carbon paper is used as a finished product, drying and hot pressing of the carbon felt are completed at a time through the drying and hot pressing device, the drying frequency of semi-finished products is reduced, and cost is reduced; the carbon felt is directly subjected to hot pressing operation after being dried, so that the rolling and transporting processes of the carbon felt are omitted, and the situation that the strength of the carbon felt is reduced due to water absorption in the transporting and storing processes of the carbon felt is avoided. The sizing process and the dipping process of the carbon felt are integrated together, material waste caused by water absorption of the carbon felt in the placing and transporting process after sizing and drying is avoided, use of absolute ethyl alcohol is avoided, the cost is reduced, the carbon paper preparation process is simplified, and meanwhile the environment-friendly effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of fuel cells, and in particular to a continuous preparation method from carbon fibers to carbon paper. Background Art

[0002] Proton exchange membrane fuel cell (PEMFC) is a device that directly converts chemical energy into electrical energy. Its reactants are hydrogen and oxygen, and the only reaction product is water, which has the advantage of being environmentally friendly. In addition, proton exchange membrane fuel cells can be started quickly and have great application potential in the fields of transportation, chemical industry, aerospace, construction, etc. The gas diffusion layer (GasDiffusion Layer, referred to as GDL) is an important component of the fuel cell. On the one hand, it can be used as a current collector for the transmission of current, and on the other hand, it can be used as a support layer for the catalyst, and transmits the reaction gas and discharges the product water. The gas diffusion layer is usually composed of a porous, non-woven and macroporous carbon substrate. The most commonly used gas diffusion layer material is carbon paper.

[0003] The carbon paper is obtained by impregnation, hot pressing, carbonization and graphitization of carbon felt, wherein the impregnation and hot pressing processes are for introducing phenolic resin into the carbon felt and solidifying it, and achieving the overlapping effect on the fibers after high temperature treatment.

[0004] The traditional carbon paper manufacturing process is separate from the carbon felt manufacturing process, that is, carbon fiber is prepared into rolled carbon felt through processes such as dispersion, dehydration molding, sizing, and drying, and the carbon felt is then prepared into carbon paper through subsequent processes such as unwinding, impregnation, drying, hot pressing, and high-temperature treatment. It can be seen from the preparation processes of carbon felt and carbon paper that both involve the introduction of glue solution on the surface of carbon felt and the drying steps. For the production lines of carbon felt and carbon paper, the drying process will increase the consumption of electrical energy and increase the cost of carbon paper. In addition, the finished carbon felt is water-absorbent, and the strength of the carbon felt will decrease after absorbing water, which is not conducive to the continuous preparation of carbon paper and affects the control of gram weight during the subsequent preparation of carbon paper. Therefore, it is necessary to reduce the preparation cost of carbon paper and the material loss of carbon felt caused by water absorption. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, an embodiment of the present invention provides a continuous preparation method from carbon fiber to carbon paper.

[0007] The present invention provides a continuous preparation method from carbon fiber to carbon paper, comprising the following steps:

[0008] (a) dispersing carbon fibers: dispersing carbon fibers in a dispersion liquid to obtain a carbon fiber dispersion liquid;

[0009] (b) carbon fiber dehydration molding: dehydrating the carbon fiber dispersion to form a carbon felt;

[0010] (c) carbon felt gluing: applying mixed glue to the carbon felt, wherein the mixed glue comprises bulk glue and phenolic resin;

[0011] (d) curing of carbon felt: drying and hot pressing the carbon felt after sizing to complete the curing of the carbon felt;

[0012] (e) High temperature treatment of carbon felt: The solidified carbon felt is subjected to carbonization and graphitization treatments in sequence.

[0013] Furthermore, the mass proportion of the bulk glue in the mixed glue is 2% to 10%, and the mass proportion of the phenolic resin in the mixed glue is 10% to 50%.

[0014] Furthermore, the main glue includes one or more of polyvinyl alcohol, acrylic acid, and styrene acrylate.

[0015] Furthermore, the step (c) of carbon felt gluing is carried out by using a gluing device, wherein the gluing device comprises a slope structure and a slope overflow module arranged immediately downstream of the slope structure, wherein the slope structure is arranged opposite to the slope end of the slope overflow module.

[0016] Furthermore, the gap between the inclined surface structure and the inclined surface overflow module forms a glue application port, and the glue application amount is adjusted by adjusting the size of the glue application port.

[0017] Furthermore, a negative pressure device is provided below the glue application port.

[0018] Furthermore, the step (d) of curing the carbon felt is carried out by using a drying and hot pressing device, wherein the drying and hot pressing device comprises a first group of heating rollers and a second group of heating rollers arranged downstream of the first group of heating rollers.

[0019] Furthermore, the first group of heating rollers is a single roller, and the first group of heating rollers is used to complete primary drying; the second group of heating rollers is a double roller, and the second group of heating rollers is used to complete extrusion and secondary drying, and the thickness of the carbon felt after gluing is controlled by extrusion.

[0020] Furthermore, the temperature of the first heating roller is 80-150°C; the temperature of the second heating roller is 150-200°C.

[0021] Furthermore, in the step (e), the carbonization temperature is 900-1300° C. and the time is 2-10 min; the graphitization temperature is 1500-2400° C. and the time is 2-10 min.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] The present invention integrates the gluing and impregnation processes of the carbon felt, thereby avoiding the waste of materials caused by water absorption during the placement and transportation of the carbon felt after gluing and drying, avoiding the use of anhydrous ethanol, reducing costs, simplifying the process of carbon paper preparation, and being environmentally friendly.

[0024] The present invention adopts a negative pressure device to provide vacuum conditions to achieve uniform distribution of glue on the carbon felt. Compared with the impregnation method, the amount of glue can be controlled more accurately and the distribution of phenolic resin can be more uniform.

[0025] The glue applying tank of the present invention adopts a "double overflow" method to stabilize the flow rate of glue. One is that the glue passes through a communicating vessel composed of a second baffle before entering the glue tank to reduce the instability of the glue flow; the other is to add an inclined overflow module on the right side of the glue applying port to form a stable fixed volume of liquid above the glue applying port, and use the stable gravity above the glue applying port to control the flow rate of the glue.

[0026] The present invention integrates the two production processes of carbon felt and carbon paper into a continuous production process. The raw material in the process is carbon fiber, and the finished product is carbon paper. The drying and hot pressing of the carbon felt is completed at one time by using a drying and hot pressing device, which reduces the number of drying times of the semi-finished products and reduces the cost. The carbon felt is directly hot-pressed after drying, which saves the winding and transportation processes of the carbon felt and avoids the reduction in the strength of the carbon felt caused by water absorption during transportation and storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0028] Figure 1 The present invention is a flow chart of the continuous preparation method from carbon fiber to carbon paper;

[0029] Figure 2 This is a schematic structural diagram of the glue application device of the present invention;

[0030] Figure 3 This is a schematic diagram of the drying and hot pressing device of the present invention;

[0031] Figure 4 This is a schematic diagram of the glue application device used in Comparative Example 1;

[0032] Figure 5 Microscope images of the upper and lower surfaces of the cured carbon felt prepared in Example 1;

[0033] Figure 6 These are microscope images of the upper and lower surfaces of the cured carbon felt prepared in Comparative Example 1.

[0034] Description of reference numerals:

[0035] 1. Glue inlet; 2. First baffle; 3. Second baffle; 4. Inclined structure; 5. Inclined overflow module; 6. Glue outlet; 7. Negative pressure device; 8. Carbon felt; 9. Glue application port; 10. Conveying device; 11. First set of heating rollers; 12. Second set of heating rollers; 13. Normal temperature rollers; 14. Conveyor belt. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0037] The following describes the continuous preparation method from carbon fiber to carbon paper proposed by the present invention in conjunction with the accompanying drawings.

[0038] like Figure 1 As shown, the continuous preparation method from carbon fiber to carbon paper of the present invention comprises the following steps:

[0039] (a) dispersing carbon fibers: dispersing carbon fibers in a dispersion liquid to obtain a carbon fiber dispersion liquid;

[0040] (b) Carbon fiber dehydration molding: dehydrating the carbon fiber dispersion to form carbon felt;

[0041] (c) carbon felt gluing: applying mixed glue to the carbon felt, the mixed glue comprising bulk glue and phenolic resin;

[0042] (d) curing of carbon felt: drying and hot pressing the carbon felt after sizing to complete the curing of the carbon felt;

[0043] (e) High temperature treatment of carbon felt: The solidified carbon felt is subjected to carbonization and graphitization treatments in sequence.

[0044] Wherein, step (a) is a dispersion process of carbon fibers, wherein carbon fibers are added to a tank containing a dispersion liquid, and the carbon fibers are dispersed under mechanical action such as stirring and ultrasound to obtain a carbon fiber dispersion liquid. The dispersion liquid includes one or more of hydroxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, polyacrylamide, and polyethylene oxide.

[0045] Step (b) is a process for forming carbon felt, in which the carbon fiber dispersion obtained in step (a) is pumped to the inclined mesh module, and then dehydrated by a vacuum pump of the inclined mesh module to form a carbon fiber wet felt.

[0046] Step (c) is the gluing process of the carbon felt, in which a mixed glue is applied to the carbon felt. The mixed glue includes bulk glue and phenolic resin. That is, the mixed glue of the present application contains not only the glue for preparing the carbon felt, but also the phenolic resin used in the impregnation process for preparing the carbon paper. This step can introduce glue and phenolic resin on the carbon felt in one step, thereby eliminating the impregnation process and simplifying the process.

[0047] The present invention integrates the gluing and impregnation processes of the carbon felt, thereby avoiding the waste of materials caused by water absorption during the placement of the carbon felt after gluing and drying, avoiding the use of anhydrous ethanol, reducing costs, and being environmentally friendly.

[0048] The bulk glue is the glue that ensures the bonding of carbon fibers during the preparation of carbon felt, including one or more of polyvinyl alcohol, acrylic acid, and styrene acrylate. Phenolic resin is a water-soluble phenolic resin, which can be converted into resin carbon during the high-temperature treatment process of preparing carbon paper, thereby enhancing the bonding between carbon fibers in carbon paper and improving the conductivity of carbon paper. The mass proportion of bulk glue in the mixed glue is 2% to 10%, the mass proportion of phenolic resin in the mixed glue is 10% to 50%, and the rest is supplemented with deionized water.

[0049] The gluing process of carbon felt can be carried out by gluing in a gluing slot, gluing in a narrow slot or spraying, and a negative pressure device is used at the same time. In some embodiments, the gluing device is used to apply gluing to carbon felt. Figure 2 The glue applying device comprises a glue inlet 1, a first baffle 2, a second baffle 3, a slope structure 4, a slope overflow module 5, a glue outlet 6, and a negative pressure device 7.

[0050] The glue is stored in a glue tank. During the gluing process, the glue is pumped from the glue inlet 1 into the glue tank. The glue tank is provided with two baffles, namely a first baffle 2 and a second baffle 3. The first baffle 2 is used to reduce the surging phenomenon when the glue comes out of the glue inlet 1. The second baffle 3 is used to form a communicating vessel structure on both sides of the baffle, thereby further improving the stability of the glue flow and preventing fluctuations in the gluing process caused by changes in the glue flow.

[0051] The inclined surface structure 4 is arranged downstream of the second baffle 3. After the glue is filled in the glue tank, the glue flows along the inclined surface of the inclined surface structure 4 to the glue application port 9. The glue application port 9 is the gap formed between the inclined surface structure 4 and the inclined surface overflow module 5. The inclined surface overflow module 5 is arranged immediately downstream of the inclined surface structure 4. The inclined surface ends of the inclined surface structure 4 and the inclined surface overflow module 5 are arranged opposite to each other. The function of the inclined surface overflow module 5 is to ensure that the total amount of liquid above the glue application port 9 is constant and the stability of the glue application flow rate is ensured. The size of the glue application port 9 is adjusted by adjusting the gap between the inclined surface structure 4 and the inclined surface overflow module 5, thereby adjusting the glue application amount on the surface of the carbon felt 8.

[0052] The glue flows to the surface of the carbon felt 8 through the glue application port 9. A negative pressure device 7 for providing vacuum is arranged below the glue application port 9. The glue flowing out of the glue application port 9 passes through the carbon felt 8 and enters the negative pressure device 7. The negative pressure device 7 can collect the glue flowing through the carbon felt 8 for recycling on the one hand, and on the other hand, can utilize the negative pressure to promote the uniform distribution of the glue in the longitudinal direction of the carbon felt 8, thereby improving the uniformity of the distribution of the glue inside the carbon felt 8.

[0053] The carbon felt 8 is driven by the conveying device 10 to move. When the carbon felt 8 passes through the glue application port 9, the glue flowing out of the glue application port 9 flows through the carbon felt 8 to complete the glue application. When the amount of glue flowing down the inclined surface structure 4 increases, the excess glue can flow into the right groove through the inclined surface overflow module 5, and flow out from the glue outlet 6, and finally flow into the glue tank for recycling. The function of the inclined surface overflow module 5 is to keep the volume of glue on the two inclined surfaces fixed, thereby ensuring that the flow rate of the glue flowing out of the glue application port 9 is fixed and improving the stability of the glue application amount.

[0054] The glue applying tank for carbon felt gluing of the present invention uses gravity to control the flow of glue and is provided with an inclined overflow module, thereby improving the stability of the glue applying flow.

[0055] The present invention adopts a negative pressure device to provide vacuum conditions to achieve uniform distribution of glue in the carbon felt. Compared with the impregnation method, the amount of glue can be controlled more accurately and the distribution of phenolic resin can be more uniform.

[0056] The glue applying tank of the present invention adopts a "double overflow" method to stabilize the flow rate of glue. One is that the glue passes through a communicating vessel composed of a second baffle before entering the glue tank to reduce the instability of the glue flow; the other is to add an inclined overflow module on the right side of the glue applying port to form a stable fixed volume of liquid above the glue applying port, and use the stable gravity above the glue applying port to control the flow rate of the glue.

[0057] In some embodiments, the carbon felt curing step is performed using a drying and hot pressing device. Figure 3 As shown, the drying and hot pressing device includes a first group of heating rollers 11 , a second group of heating rollers 12 and a normal temperature roller 13 , and the second group of heating rollers 12 is arranged downstream of the first group of heating rollers 11 .

[0058] The first set of heating rollers 11 is a single roller, and the number of single rollers can be adjusted according to the actual working conditions. The first set of heating rollers 11 is located below the carbon felt. The first set of heating rollers 11 is used to complete the primary drying. The first set of heating rollers 11 can accelerate the evaporation of water in the carbon felt after gluing. The temperature of the first heating roller is 80-150°C. The second set of heating rollers 12 is a double roller. The second set of heating rollers 12 is used to complete the extrusion and secondary drying. On the one hand, the phenolic resin in the glue can be solidified under high temperature conditions. On the other hand, the thickness of the carbon felt after gluing can be controlled by extrusion, that is, the thickness of the carbon felt after gluing can be controlled by adjusting the extrusion pressure. The temperature of the second set of heating rollers 12 is 150-200°C. After the carbon felt passes through the second set of heating rollers 12, the normal temperature roller 13 drives the conveyor belt 14 to send the hot-pressed carbon felt to the subsequent processing technology, wherein the conveyor belt 14 has a running speed of 2-10m / min.

[0059] The present invention utilizes a drying and hot pressing device to complete the drying and hot pressing of the carbon felt at one time, thereby reducing the number of drying times of the semi-finished product and reducing the cost; the carbon felt is directly hot pressed after being dried, thereby eliminating the winding and transportation processes of the carbon felt and avoiding the reduction in the strength of the carbon felt caused by water absorption during transportation and storage.

[0060] The carbon felt after gluing is dried by a first set of heating rollers 11, and the first set of heating rollers 11 is located below the carbon felt. The carbon felt is in a wet state after gluing and before drying. The glue on the carbon felt will flow from top to bottom due to gravity, resulting in less glue content in the upper layer of the carbon felt and more glue content in the lower layer. The present application adopts a bottom-up drying method for the carbon felt. During the drying process, the moisture contained in the carbon felt will turn into water vapor when heated. The water vapor will move upward in the vertical direction of the carbon felt, generating a vertical upward force on the glue, thereby offsetting the gravity of the glue flowing downward and improving the uniformity of the glue distribution in the vertical direction of the carbon felt.

[0061] The high temperature treatment process of the carbon felt in step (e) includes carbonization and graphitization of the carbon felt, which are carried out in a carbonization furnace and a graphitization furnace respectively. The carbonization temperature is 900-1300° C. and the time is 2-10 min; the graphitization temperature is 1500-2400° C. and the time is 2-10 min.

[0062] The method of the present invention is described below with reference to specific embodiments.

[0063] Example 1

[0064] The carbon fiber is dispersed in a hydroxymethyl cellulose dispersion to obtain a carbon fiber dispersion with a mass concentration of 0.01%, and the carbon fiber dispersion is transported to an inclined mesh module through a pump, and then dehydrated by a vacuum pump of the inclined mesh module to form a carbon fiber wet felt.

[0065] use Figure 2The glue application device shown applies mixed glue to the carbon felt, wherein the vacuum degree of the negative pressure device 7 is -25 kPa, the width of the glue application port is 2 mm, the mass proportion of phenolic resin in the mixed glue is 20%, and the mass proportion of acrylic acid in the main glue is 6%.

[0066] use Figure 3 The drying and hot pressing device shown dries and hot presses the carbon felt after gluing, wherein the temperature of the first group of heating rollers is 120°C, the temperature of the second group of heating rollers 12 is 180°C, the extrusion pressure of the second group of heating rollers is 0.1MPa, and the conveyor belt speed is 5m / min.

[0067] The dried and hot-pressed carbon felt was treated in a carbonization furnace at 1000°C for 5 min, then treated in a graphitization furnace at 2000°C for 8 min, and then cooled to form carbon paper.

[0068] Example 2

[0069] The carbon fiber is dispersed in the dispersion liquid polyethylene oxide to obtain a carbon fiber dispersion liquid with a mass concentration of 0.015%, and the carbon fiber dispersion liquid is transported to the inclined mesh module through a pump, and then dehydrated by the vacuum pump of the inclined mesh module to form a carbon fiber wet felt.

[0070] use Figure 2 The glue applying device shown applies mixed glue to the carbon felt, wherein the vacuum degree of the negative pressure device 7 is -18 kPa, the width of the glue applying port is 1 mm, the mass proportion of phenolic resin in the mixed glue is 40%, and the mass proportion of polyvinyl alcohol in the main glue is 4%.

[0071] use Figure 3 The drying and hot pressing device shown dries and hot presses the carbon felt after gluing, wherein the temperature of the first group of heating rollers is 80°C, the temperature of the second group of heating rollers is 150°C, the extrusion pressure of the second group of heating rollers is 0.2MPa, and the conveyor belt speed is 10m / min.

[0072] The dried and hot-pressed carbon felt was treated in a carbonization furnace at 1000°C for 5 min, then treated in a graphitization furnace at 2000°C for 8 min, and then cooled to form carbon paper.

[0073] Example 3

[0074] The carbon fiber is dispersed in a dispersion liquid of hydroxypropyl methylcellulose to obtain a carbon fiber dispersion liquid with a mass concentration of 0.005%, and the carbon fiber dispersion liquid is transported to an inclined mesh module through a pump, and then dehydrated by a vacuum pump of the inclined mesh module to form a carbon fiber wet felt.

[0075] use Figure 2The glue application device shown applies the mixed glue to the carbon felt, wherein the vacuum degree of the negative pressure device is -2kPa, the width of the glue application port is 1cm, the mass proportion of phenolic resin in the mixed glue is 15%, and the mass proportion of styrene acrylate in the bulk glue is 10%.

[0076] use Figure 3 The drying and hot pressing device shown dries and hot presses the carbon felt after gluing, wherein the temperature of the first group of heating rollers is 150°C, the temperature of the second group of heating rollers is 200°C, the extrusion pressure of the second group of heating rollers is 0.05MPa, and the conveyor belt speed is 3m / min.

[0077] The dried and hot-pressed carbon felt was treated in a carbonization furnace at 1000°C for 5 min, then treated in a graphitization furnace at 2000°C for 8 min, and then cooled to form carbon paper.

[0078] Comparative Example 1

[0079] The difference from Example 1 is that Figure 4 As shown, the glue application device used in the glue application process does not have a negative pressure device and a slope overflow module of the glue application tank.

[0080] Test example

[0081] The cured carbon felts prepared in Example 1 and Comparative Example 1 were characterized by optical microscopy. Figure 5 and Figure 6 As shown, from Figure 5 It can be seen that the glue on the upper and lower surfaces of the cured carbon felt prepared in Example 1 is evenly distributed; Figure 6 It can be seen that the glue on the upper surface of the cured carbon felt prepared in Comparative Example 1 is more, while the glue on the lower surface is less, and the glue distribution is uneven. It can be seen that the preparation method of the present application achieves uniform distribution of glue on the carbon felt.

[0082] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms may be for different embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0083] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0084] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A continuous preparation method from carbon fiber to carbon paper, characterized in that: The following steps are involved: (a) dispersing carbon fibers: dispersing carbon fibers in a dispersion liquid to obtain a carbon fiber dispersion liquid; (b) carbon fiber dehydration molding: dehydrating the carbon fiber dispersion to form a carbon felt; (c) carbon felt gluing: applying mixed glue to the carbon felt, wherein the mixed glue comprises bulk glue and phenolic resin; (d) curing of carbon felt: drying and hot pressing the carbon felt after sizing to complete the curing of the carbon felt; (e) High temperature treatment of carbon felt: The solidified carbon felt is subjected to carbonization and graphitization treatments in sequence.

2. The method according to claim 1, characterized in that The mass proportion of the bulk glue in the mixed glue is 2% to 10%, and the mass proportion of the phenolic resin in the mixed glue is 10% to 50%.

3. The method according to claim 1, characterized in that The bulk glue includes one or more of polyvinyl alcohol, acrylic acid, and styrene acrylate.

4. The method according to claim 1, characterized in that The step (c) of carbon felt gluing is implemented by using a gluing device, wherein the gluing device comprises a slope structure and a slope overflow module arranged immediately downstream of the slope structure, wherein the slope structure is arranged opposite to the slope end of the slope overflow module.

5. The method according to claim 4, characterized in that The gap between the inclined surface structure and the inclined surface overflow module forms a glue application port, and the glue application amount can be adjusted by adjusting the size of the glue application port.

6. The method according to claim 5, characterized in that A negative pressure device is arranged below the glue application port.

7. The method according to claim 1, characterized in that The step (d) of curing the carbon felt is carried out by using a drying and hot pressing device, wherein the drying and hot pressing device comprises a first group of heating rollers and a second group of heating rollers arranged downstream of the first group of heating rollers.

8. The method according to claim 7, characterized in that The first set of heating rollers is a single roller, and the first set of heating rollers is used to complete primary drying; the second set of heating rollers is a double roller, and the second set of heating rollers is used to complete extrusion and secondary drying, and the thickness of the carbon felt after gluing is controlled by extrusion.

9. The method according to claim 7, characterized in that The temperature of the first heating roller is 80-150°C; the temperature of the second heating roller is 150-200°C.

10. The method according to claim 1, characterized in that In the step (e), the carbonization temperature is 900-1300° C. and the time is 2-10 min; the graphitization temperature is 1500-2400° C. and the time is 2-10 min.

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