High-conductivity carbon fiber felt composite material and preparation method thereof

Abstract

The invention discloses a high-conductivity carbon fiber felt composite material and a preparation method thereof, and the preparation method comprises the following steps: providing silver nanowires, and dispersing the silver nanowires in a first solvent to form a silver nanowire dispersion liquid; providing short carbon fibers, and mixing and dispersing the short carbon fibers, a binder and an auxiliary agent in a second solvent to form a carbon fiber dispersion liquid; mixing the silver nanowire dispersion liquid with the carbon fiber dispersion liquid, and then standing to obtain mixed slurry; diluting the mixed slurry, and then carrying out wet papermaking molding to obtain a wet carbon fiber felt; and drying the wet carbon fiber felt to cure the binder to obtain the high-conductivity carbon fiber felt composite material. According to the invention, a three-dimensional continuous conductive network is constructed at the cross points of the carbon fibers through the silver nanowires, the conductivity and electromagnetic shielding performance of the composite material are remarkably improved, meanwhile, the lightweight characteristic of the carbon fibers is reserved, the process is simple and efficient, and large-scale production can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic shielding materials, and in particular to a high-conductivity carbon fiber felt composite material and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of modern electronic information technology, electromagnetic radiation pollution has become an environmental and engineering problem that needs to be solved urgently. High-intensity electromagnetic radiation not only causes signal interference and malfunction to precision electronic equipment such as communication equipment and computer systems, but is also listed as a potential carcinogen by the World Health Organization, posing a serious threat to human health. Electromagnetic shielding mainly attenuates electromagnetic waves through reflection, absorption and multiple reflections. The current mainstream electromagnetic shielding materials mainly rely on metal sheets or metal filler composite materials. However, these materials have three inherent defects: First, the density is too high (>3000kg / m 3 First, they significantly increase the weight of portable devices and aerospace payloads; second, they suffer from poor formability, making it difficult to adapt to complex curved surfaces; and third, they suffer from limited flexibility in electromagnetic performance adjustment, failing to meet multi-band compatibility requirements. These drawbacks severely restrict the application of metal-based materials in lightweight applications such as 5G communications and wearable devices.

[0003] Carbon fiber felt is an emerging lightweight flexible shielding material (density <100kg / m 3 Carbon fiber felt, manufactured through processes such as wet forming or needle punching, has shown potential for application in electromagnetic shielding due to its flexibility, lightweight, high specific surface area, and high-temperature resistance. However, traditional carbon fiber felt relies on physical contact at the intersections of the carbon fibers to form a conductive pathway. These intersections account for a relatively small proportion of the material's total volume, resulting in an extremely limited conductive pathway and high contact resistance. Furthermore, the shielding effectiveness (SE) of traditional carbon fiber felt is modest, failing to meet the protection requirements of millimeter-wave communication equipment.

[0004] To overcome the above limitations, the existing technology has attempted a variety of improvement solutions, but all of them have significant defects: Chinese patent CN118457015A discloses a method for preparing a carbon fiber composite material with thermal conductivity and electromagnetic shielding properties: using magnetron sputtering to alternately deposit Cu and AlN particles layer by layer on the surface of the carbon fiber to obtain functionalized fibers; forming the functionalized fibers into functionalized carbon fiber mesh; and alternately layering the functionalized carbon fiber mesh with carbon fiber unidirectional cloth, with the outermost layer being the carbon fiber unidirectional cloth. This method, which uses magnetron sputtering to deposit Cu / AlN particles on the carbon fiber surface, improves conductivity, but the vacuum process has an insufficient deposition rate, a complex preparation process, and high production costs, making it difficult to achieve mass and continuous production.

[0005] Chinese patent CN110258106B discloses a method for preparing a sandwich-type flexible electromagnetic shielding material based on carbon fiber fabric, metal nickel nanoparticles and graphene. The metal nickel nanoparticle / carbon fiber fabric composite material is prepared by magnetron sputtering. The preparation process is complex, the cost is high, and it is difficult to mass produce.

[0006] Chinese patent CN120158042A discloses a graphite / carbon fiber felt / epoxy composite material with a three-dimensional thermally conductive network. The composite is prepared by combining graphite and carbon fiber surface felt to form a three-dimensional graphite / carbon fiber felt thermally conductive network, which is then composited with an epoxy resin matrix. This technology uses two-dimensional graphite flakes as filler, resulting in poor electrical connectivity and conductivity.

[0007] In summary, current technologies are unable to achieve efficient conductive bridging between fibers through a simple, scalable approach while maintaining the lightweight properties of carbon fiber. Therefore, a breakthrough solution is urgently needed that can circumvent the cost bottlenecks of complex processes such as magnetron sputtering while overcoming the structural defects of two-dimensional fillers. By constructing a three-dimensional continuous conductive network, this solution can solve the core pain points of carbon fiber felt, such as poor conductivity and weak high-frequency shielding effectiveness, and open up a new path for lightweight electromagnetic shielding materials. Summary of the Invention

[0008] To address the aforementioned technical issues, the present invention aims to provide a highly conductive carbon fiber felt composite material and its preparation method. This method utilizes silver nanowires to construct a three-dimensional continuous conductive network at the intersections of the carbon fibers, significantly improving the composite material's electrical conductivity and electromagnetic shielding performance while retaining the lightweight properties of carbon fibers. The process is simple and efficient, enabling large-scale production.

[0009] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions: A method for preparing a highly conductive carbon fiber felt composite material comprises the following steps: S1. Preparing a silver nanowire dispersion: providing silver nanowires and dispersing them in a first solvent to form a stable silver nanowire dispersion; this step employs a low-speed, long-term dispersion process with a rotation speed of 10-500 rpm and a time of 1-120 min; S2. Preparing a carbon fiber dispersion: providing chopped carbon fibers, and mixing and dispersing them with a binder and an additive for promoting fiber dispersion in a second solvent to form a uniform carbon fiber dispersion; in this step, the speed of the stirrer used for dispersion is 10 to 1000 rpm, and the time is 1 to 60 minutes; S3. Mixing: The silver nanowire dispersion and the carbon fiber dispersion are mixed, and then allowed to stand for a period of 1 minute to allow the high-density silver nanowires to preferentially settle under gravity and accumulate at the intersections of the carbon fiber network, thereby obtaining a mixed slurry. In this step, the silver nanowire dispersion and the carbon fiber dispersion are uniformly stirred in a stirrer at a speed of 10 to 1000 rpm for a period of 1 to 60 minutes. S4, forming and shaping: diluting the mixed slurry, and then performing wet papermaking and shaping to obtain a wet carbon fiber felt; S5. Drying: Drying the wet carbon fiber felt to solidify the binder and to bond and fix the silver nanowires to the carbon fibers to form a highly conductive carbon fiber felt composite material in which the silver nanowires construct a three-dimensional continuous conductive network in the carbon fiber network.

[0010] Furthermore, in step S1, the diameter of the silver nanowires is 1-100 nm, and the aspect ratio is 100-5000.

[0011] Furthermore, in step S1, the solid content of the silver nanowire dispersion is 0.1-10%; and / or the first solvent is water, ethanol or a mixture of water and ethanol.

[0012] Furthermore, in step S2, the length of the chopped carbon fiber is 0.1-10 mm; and / or the specification of the carbon fiber tow is 1 k-12 k.

[0013] Furthermore, in step S2, the solid content of the carbon fiber in the carbon fiber dispersion is 0.5% to 2%; and / or the second solvent is water, ethanol, or a mixture of water and ethanol.

[0014] Furthermore, in step S2, the binder is at least one of polyurethane, epoxy resin, and polyacrylic resin; the amount of the binder added is 1-10% of the weight of the chopped carbon fiber; the auxiliary agent is at least one of polyvinyl alcohol, hydroxyethyl cellulose, and sodium carboxymethyl cellulose; the content of the auxiliary agent in the carbon fiber dispersion is 0.5-1.5%.

[0015] Furthermore, in step S3, the mixing ratio of the silver nanowire dispersion and the carbon fiber dispersion is such that the dry weight ratio of the silver nanowires to the carbon fibers is 1:100 to 1:5.

[0016] Furthermore, in step S4, the mixed slurry is diluted to a carbon fiber solid content of 0.05-0.5%.

[0017] Furthermore, in step S5, the drying temperature is 60-80° C., and the drying time is 30-45 minutes.

[0018] Another aspect of the present application provides a high-conductivity carbon fiber felt composite material prepared by the above preparation method, the grammage of the carbon fiber felt composite material is 5-100 g / m 2 , and the square resistance is 0.01-1.5 Ω / □.

[0019] The present application has the following advantages: (1) The carbon fiber felt composite material of the present application has achieved a breakthrough in the aspect of conductive performance. Among them, the silver nanowires, with their high density characteristics, effectively settle down and preferentially enrich at the intersection nodes of the carbon fiber network during the standing process, and combine with the fluid shear force and capillary force generated during the papermaking process to further strengthen the bridging and fixing of silver nanowires at the intersection nodes of carbon fibers, thereby realizing the erection of a continuous conductive bridge between the fiber gaps through one-dimensional linear structures and the construction of a highly efficient three-dimensional continuous conductive network. This unique design enables the composite material to achieve excellent conductivity at a very low silver nanowire addition amount, with a square resistance as low as 0.01-1.5 Ω / □.

[0020] (2) The composite material has excellent electromagnetic shielding performance; due to the good continuity and integrity of the three-dimensional conductive network constructed by silver nanowires, it can effectively reflect and absorb electromagnetic waves, so that its electromagnetic shielding effectiveness (SE) can be stably maintained at more than 40 dB in a wide frequency range of 10 MHz to 40 GHz, especially in the high-frequency millimeter wave band, fully meeting the needs of modern 5G communication and high-speed electronic equipment for high-frequency electromagnetic protection.

[0021] (3) The composite material of the present application successfully balances high performance and lightweight characteristics; the composite material uses lightweight carbon fibers as the skeleton and realizes functional enhancement by introducing a small amount of silver nanowires, and the grammage of the final product can be controlled in a relatively low range of 5-100 g / m 2 , perfectly inheriting the light weight advantage of carbon fiber materials, and is very suitable for aerospace, portable electronic products and other fields with strict requirements on weight.

[0022] (4) The present application innovatively uses a wet papermaking technology platform to composite silver nanowires and carbon fibers in liquid phase, replacing traditional processes such as magnetron sputtering and chemical vapor deposition that rely on high vacuum and high energy consumption. The entire process can be carried out in a normal pressure environment, with simple equipment requirements and convenient operation, significantly shortening the production cycle and greatly reducing energy consumption, perfectly meeting the needs of large-scale continuous production, and fundamentally solving the industry's core pain points of high cost and limited production capacity due to the complexity of high-performance electromagnetic shielding material preparation process. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Electromagnetic shielding performance diagram of the carbon fiber felt composite material of Example 3.

[0024] DETAILED DESCRIPTION The technical solutions in the present application will be clearly and completely described below in combination with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0025] The present application provides a preparation method of high-conductivity carbon fiber felt composite material, comprising the following steps: S1, preparing silver nanowire dispersion liquid: providing silver nanowires and dispersing them in a first solvent to form a stable silver nanowire dispersion liquid; low-speed long-time dispersion is adopted in this step, and the rotation speed is preferably 10-500 rpm, more preferably 50-200 rpm, and the time is 1-120 min, more preferably 30-60 min; low-speed long-time dispersion can maximize the structural integrity and aspect ratio of silver nanowires under the premise of ensuring sufficient dispersion of silver nanowires; In this step S1, the diameter of silver nanowires is preferably 1-100 nm, more preferably 10-30 nm, and the aspect ratio is preferably 100-5000, more preferably 800-2000. The preferred diameter of silver nanowires can ensure that silver nanowires have significant surface effect and flexibility, can closely adhere to the surface of carbon fibers, and form low-resistance surface contact instead of point contact. Too large diameter reduces the specific surface area and adaptability, and too small diameter easily causes aggregation. The preferred aspect ratio 100-5000 can ensure that a single silver nanowire can span multiple carbon fiber cross points, effectively connect the originally isolated or poorly contacted fiber nodes like a "bridge", significantly increase the number and continuity of conductive paths, and is the structural basis for building a three-dimensional conductive network.

[0026] In this step S1, the solid content of the silver nanowire dispersion liquid is 0.1-10%, more preferably 0.5-5%; and the first solvent is preferably water, ethanol or a mixture of water and ethanol. This solid content range balances the dispersion stability and process efficiency. Too low solid content requires a large amount of silver nanowire dispersion liquid for subsequent mixing, increasing the process complexity; too high solid content makes dispersion difficult, easily leading to silver nanowire aggregation and affecting the final conductive uniformity.

[0027] S2, preparing carbon fiber dispersion liquid: providing short-cut carbon fibers and mixing and dispersing them with a binder and an additive for promoting fiber dispersion in a second solvent to form a uniform carbon fiber dispersion liquid; in this step, the rotation speed of the stirrer used for dispersion is preferably 10-1000 rpm, further preferably 100-500 rpm, and the time is 1-60 min, further preferably 10-30 min; The length of the chopped carbon fiber is preferably 0.1-10 mm, more preferably 0.5-5 mm; and the specification of the carbon fiber bundle is preferably 1k-12k. The chopped carbon fiber with the length in the range can form a uniform fiber network in the papermaking process, which ensures the mechanical strength of the felt and provides enough cross points as the "anchor points" for the silver nanowire bridging. If the fiber is too short, the network strength is insufficient, and if the fiber is too long, it is difficult to disperse uniformly. The carbon fiber bundle with the preferred specification range is beneficial to form a fiber network with moderate density after cutting and dispersing, which can ensure the density of the conductive path and avoid the difficulty in dispersing and the formation of local enrichment area in the felt.

[0028] The solid content of the carbon fiber in the carbon fiber dispersion liquid is 0.5%-2%, and is further preferably 0.5%-1%; and the second solvent is preferably water, ethanol or a mixture of water and ethanol. The carbon fiber solid content is beneficial to the wet papermaking process. If the solid content is too low, the production efficiency is low; and if the solid content is too high, the slurry viscosity is too large, the fiber is difficult to disperse uniformly, and the felt uniformity is affected by the flocculation during the papermaking.

[0029] In the step S2, the binder is at least one of polyurethane, epoxy resin and polyacrylic resin; the addition amount of the binder is 1-10% of the weight of the chopped carbon fiber, and is further preferably 2-8%; the binder can effectively "weld" and fix the silver nanowire at the carbon fiber cross point, preventing it from falling off in the subsequent processing or use. The additive is at least one of polyvinyl alcohol, hydroxyethyl cellulose and sodium carboxymethyl cellulose; the content of the additive in the carbon fiber dispersion liquid is 0.5-1.5%. The additive can effectively improve the dispersibility of the hydrophobic carbon fiber in the system, prevent fiber flocculation and ensure the formation of a uniform fiber network.

[0030] S3, mixing: mixing the silver nanowire dispersion liquid and the carbon fiber dispersion liquid, and then standing to treat, so that the high-density silver nanowire preferentially settles and enriches at the cross node of the carbon fiber network, to obtain a mixed slurry; the silver nanowire dispersion liquid and the carbon fiber dispersion liquid are uniformly mixed by using a stirrer, the stirring speed of the stirrer is 10-1000 rpm, and the stirring time is 1-60 min; the mixing ratio of the silver nanowire dispersion liquid and the carbon fiber dispersion liquid is such that the dry mass ratio of silver nanowire to carbon fiber is 1:100-1:5. The standing time is 20-40 min.

[0031] S4, forming and shaping: diluting the mixed slurry to a carbon fiber solid content of 0.05-0.5%, and then performing wet papermaking to form a wet-state carbon fiber felt; S5. Drying: Drying the wet carbon fiber felt to solidify the binder and bond the silver nanowires to the carbon fibers, forming a highly conductive carbon fiber felt composite material in which the silver nanowires construct a three-dimensional continuous conductive network within the carbon fiber network. In this step, the drying temperature is 60-80°C and the drying time is 30-45 minutes. If the drying temperature is too low or the drying time is too short, the binder will not be fully solidified, resulting in an unstable network structure. If the temperature is too high, the silver nanowires may be oxidized or melted and agglomerated, destroying the conductive network structure that has been formed and possibly damaging the carbon fibers and the binder.

[0032] The highly conductive carbon fiber felt composite material prepared by the above-mentioned preparation method has a gram weight of 5~100g / m 2 , further 10~50g / m 2 , the square resistance is 0.01~1.5Ω / □.

[0033] Example 1 S1. Preparation of a silver nanowire dispersion: Add silver nanowire wet powder with a diameter of approximately 20 nm and an aspect ratio of approximately 1500 to deionized water and disperse at 100 rpm using a disperser for 40 minutes to obtain a silver nanowire aqueous dispersion with a solid content of 2%; S2. Prepare a carbon fiber dispersion: Chop a 3k polyacrylonitrile-based carbon fiber tow into 3mm long chopped fibers. Weigh a certain amount of the chopped carbon fibers and add them to deionized water. Add a polyurethane binder (5% by weight of the carbon fibers) and a sodium carboxymethyl cellulose additive (1.0% by weight of the system). Use a blender to stir at 300 rpm for 20 minutes to form a uniform carbon fiber dispersion with a carbon fiber solids content of 0.8%. S3. Mixing: The silver nanowire dispersion obtained in step S1 is mixed with the carbon fiber dispersion obtained in step S2 at a silver / carbon dry weight ratio of 1:20. The mixture is stirred at 200 rpm for 15 minutes to achieve preliminary mixing, followed by 30 minutes of undisturbed mixing to obtain a mixed slurry. During this process, the high-density silver nanowires preferentially settle under gravity and accumulate at the intersections of the carbon fiber network. S4. Forming and shaping: The mixed slurry is diluted with water to a carbon fiber solid content of 0.1%, and then transported to a papermaking machine for wet papermaking and shaping. During the dewatering process in the web section, the fluid shear force and capillary force further strengthen the bridging and fixation of the silver nanowires at the fiber intersections, resulting in a wet carbon fiber mat. S5. Drying: The wet carbon fiber felt is transferred to a forced air drying oven and dried at 70°C for 40 minutes. The polyurethane binder is fully cured, firmly bonding the silver nanowires to the carbon fiber network, and ultimately producing a highly conductive carbon fiber felt composite material.

[0034] After testing, the composite material has a gram weight of 35g / m2 , the square resistance is 0.5Ω / □.

[0035] Example 2 S1. Preparation of a silver nanowire dispersion: Silver nanowires with a diameter of approximately 50 nm and an aspect ratio of approximately 800 were dispersed in a mixed solvent of ethanol and water using a disperser at a rotation speed of 150 rpm for 50 minutes to obtain a silver nanowire dispersion with a solid content of 1.5%.

[0036] S2. Prepare a carbon fiber dispersion: Chop 6k carbon fiber tow into 5mm long fibers. Mix the fibers with an epoxy resin binder (3% by weight of the carbon fibers) and a hydroxyethyl cellulose additive (1.2% by weight of the total system) in water. Stir at 400 rpm for 15 minutes to obtain a carbon fiber dispersion with a carbon fiber solids content of 0.6%. S3. Mixing: The two dispersions were mixed at a silver / carbon dry weight ratio of 1:50, stirred at 250 rpm for 10 minutes, and allowed to stand for 25 minutes to obtain a mixed slurry; S4, forming and shaping: diluting the mixed slurry to a carbon fiber solid content of 0.08%, and then forming and shaping to obtain a wet carbon fiber felt; S5. Drying: Dry the wet carbon fiber felt at 65° C. for 35 minutes to cure the epoxy resin.

[0037] After testing, the composite material weight is 20g / m 2 , the square resistance is 1.5Ω / □.

[0038] Example 3 S1. Preparing a silver nanowire dispersion: dispersing silver nanowires with a diameter of about 15 nm and an aspect ratio of about 1800 in water at 100 rpm for 50 minutes to prepare a silver nanowire dispersion with a solid content of 3%; S2. Prepare a carbon fiber dispersion: Chop 6k carbon fibers into 4mm lengths. Mix with 7% polyacrylic acid resin binder and 1% polyvinyl alcohol additive, and stir at 400 rpm for 15 minutes to prepare a carbon fiber dispersion with a carbon fiber solid content of 1.2%. S3. Mixing: The silver nanowire dispersion and the carbon fiber dispersion were mixed at a silver / carbon dry weight ratio of 1:15, stirred at 200 rpm for 15 minutes, and then allowed to stand for 35 minutes to obtain a mixed slurry; S4, forming and shaping: diluting the mixed slurry to a carbon fiber solid content of 0.12%, and then forming and shaping to obtain a wet carbon fiber felt; S5. Drying: Dry the wet carbon fiber felt at 75°C for 40 minutes to ensure that the binder is completely cured.

[0039] After testing, the composite material weight is 50g / m 2 , the square resistance is 0.1Ω / □.

[0040] Figure 1 This is a graph showing the electromagnetic shielding performance of the carbon fiber felt composite material of Example 3. It can be seen from the graph that the electromagnetic shielding effectiveness (SE) thereof can be stably maintained above 40 dB in a wide frequency range of 10 MHz to 40 GHz.

[0041] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0042] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for preparing a highly conductive carbon fiber felt composite material, characterized in that: The following steps are involved: S1. Preparing a silver nanowire dispersion: providing silver nanowires and dispersing them in a first solvent to form a stable silver nanowire dispersion; S2. Preparing a carbon fiber dispersion: providing chopped carbon fibers, and mixing and dispersing the chopped carbon fibers with a binder and an additive for promoting fiber dispersion in a second solvent to form a uniform carbon fiber dispersion; S3. Mixing: Mixing the silver nanowire dispersion with the carbon fiber dispersion, and then allowing the high-density silver nanowires to preferentially settle under gravity and accumulate at the intersection nodes of the carbon fiber network to obtain a mixed slurry; S4, forming and shaping: diluting the mixed slurry, and then performing wet papermaking and shaping to obtain a wet carbon fiber felt; S5. Drying: Drying the wet carbon fiber felt to solidify the binder and to bond and fix the silver nanowires to the carbon fibers to form a highly conductive carbon fiber felt composite material in which the silver nanowires construct a three-dimensional continuous conductive network in the carbon fiber network.

2. The method for preparing a highly conductive carbon fiber felt composite material according to claim 1, wherein: In step S1, the diameter of the silver nanowires is 1-100 nm, and the aspect ratio is 100-5000.

3. The method for preparing a highly conductive carbon fiber felt composite material according to claim 1, wherein: In step S1, the solid content of the silver nanowire dispersion is 0.1-10%; and / or the first solvent is water, ethanol, or a mixture of water and ethanol.

4. The method for preparing a highly conductive carbon fiber felt composite material according to claim 1, wherein: In step S2, the length of the chopped carbon fiber is 0.1-10 mm; and / or the specification of the carbon fiber tow is 1 k-12 k.

5. The method for preparing a highly conductive carbon fiber felt composite material according to claim 1, wherein: In step S2, the solid content of the carbon fiber in the carbon fiber dispersion is 0.5% to 2%; and / or the second solvent is water, ethanol, or a mixture of water and ethanol.

6. The method for preparing a highly conductive carbon fiber felt composite material according to claim 1, wherein: In step S2, the binder is at least one of polyurethane, epoxy resin, and polyacrylic resin; the amount of the binder added is 1-10% of the weight of the chopped carbon fiber; the additive is at least one of polyvinyl alcohol, hydroxyethyl cellulose, and sodium carboxymethyl cellulose; the content of the additive in the carbon fiber dispersion is 0.5-1.5%.

7. The method for preparing a highly conductive carbon fiber felt composite material according to claim 1, wherein: In step S3, the mixing ratio of the silver nanowire dispersion and the carbon fiber dispersion is such that the dry weight ratio of the silver nanowires to the carbon fibers is 1:100 to 1:

5.

8. The method for preparing a highly conductive carbon fiber felt composite material according to claim 1, wherein in step S4, the mixed slurry is diluted to a carbon fiber solid content of 0.05-0.5%.

9. The method for preparing a highly conductive carbon fiber felt composite material according to claim 1, wherein: In step S5, the drying temperature is 60-80° C., and the drying time is 30-45 minutes.

10. A highly conductive carbon fiber felt composite material prepared by the preparation method according to any one of claims 1 to 9, characterized in that: The carbon fiber felt composite material has a gram weight of 5 to 100 g / m 2 , the square resistance is 0.01~1.5Ω / □.

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