Highly conductive pitch-based carbon fiber prepreg and method for making the same

Abstract

This invention discloses a highly conductive pitch-based carbon fiber prepreg and its preparation method. The preparation method includes the following steps: applying a conductive resin slurry; treating pitch-based carbon fiber bundles in a high-pressure plasma treatment chamber; and impregnating and pre-curing the prepreg in an ultrasonic field to form the highly conductive pitch-based carbon fiber prepreg. The method provided by this invention utilizes plasma treatment chamber activation to provide anchor points and ultrasonic-driven nanofiller bridging to form a three-dimensional conductive network skeleton in the carbon fiber prepreg. After curing, the prepreg achieves ultra-high volume conductivity comparable to metals, excellent electromagnetic shielding effectiveness, and superior space thermal cycling stability even without secondary metallization. This allows the carbon fiber prepreg to meet the integrated requirements of lightweight, high conductivity, and high shielding performance for high-frequency aerospace components.

Description

Technical Field

[0001] This invention relates to the field of high-performance composite materials technology, and in particular to a highly conductive pitch-based carbon fiber prepreg and its preparation method. Background Technology

[0002] As communication satellites evolve towards higher frequencies (such as Ka and V bands) and higher power, extremely high demands are placed on the lightweighting of antenna reflectors and electronic payload bays, signal reflection efficiency, and electromagnetic interference (EMI) shielding performance. Traditional metal materials are too heavy, while ordinary PAN-based carbon fiber composites have low conductivity, often requiring "secondary metallization" treatments (such as surface copper mesh, vacuum aluminum / silver plating, etc.) to meet signal reflection or shielding requirements. This not only significantly increases structural weight, but also, under the intense temperature cycling of space (±100℃), the mismatch in thermal expansion coefficients (CTE) between the metal coating and the resin matrix makes them highly susceptible to electrochemical corrosion, delamination, or peeling, ultimately leading to antenna signal distortion or even failure.

[0003] While existing pitch-based carbon fibers possess a highly ordered graphite microcrystalline structure and extremely high intrinsic conductivity, their smooth surface and chemical inertness make them unsuitable for direct, metal-free applications in high-end antennas and signal shielding. In traditional impregnation processes, the insulating resin matrix forms an "insulating layer" between the fibers, cutting off electron transport pathways. This prevents the composite material from fully utilizing the intrinsic conductivity of the fibers, hindering its direct, metal-free application in high-end antennas and signal shielding.

[0004] Therefore, there is an urgent need for a preparation method to solve the above-mentioned technical problems. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of pitch-based carbon fiber in the fields of high-end antennas and signal shielding, the present invention provides a method for preparing a highly conductive pitch-based carbon fiber prepreg, which can achieve the effect of maintaining ultra-high conductivity and lightweight characteristics without secondary metallization.

[0006] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0007] A method for preparing a highly conductive pitch-based carbon fiber prepreg, the method comprising the following steps:

[0008] Conductive nanofillers are dispersed in cyanate ester resin to form a conductive resin slurry;

[0009] After being mechanically and air-flowed, preheated and dehumidified, pitch-based carbon fiber bundles or fabrics are continuously and uniformly passed through an atmospheric pressure plasma treatment chamber with working gas.

[0010] Under inert gas protection, the treated pitch-based carbon fiber bundles or fabrics are impregnated in the prepared conductive resin slurry under an applied ultrasonic field to form a preliminary three-dimensional conductive network skeleton.

[0011] After impregnation, the fibers are extruded by extrusion rollers to remove excess resin and air bubbles, and then pre-cured at low temperature to form a stable three-dimensional conductive network skeleton, thus obtaining a highly conductive pitch-based carbon fiber prepreg.

[0012] According to one aspect of the present invention, the conductive nanofiller comprises multi-walled carbon nanotubes and graphene nanosheets; the total amount of the conductive nanofiller added is 0.5%-50% of the mass of the cyanate ester resin.

[0013] According to one aspect of the present invention, the dispersion step includes: co-processing with a high-speed shear mixer at a rotation speed of 2000-5000 rpm and a probe-type ultrasonic power of 300-800W and a frequency of 20-40Hz for 20-60 minutes.

[0014] According to one aspect of the present invention, the working gas is a mixture of argon and oxygen, wherein oxygen accounts for 1%-10% of the volume of the working gas.

[0015] According to one aspect of the present invention, the rated radio frequency power of the atmospheric pressure plasma treatment chamber is 200-800 W, and the processing time is 2-10 seconds.

[0016] According to one aspect of the present invention, the fibers treated in the atmospheric pressure plasma treatment chamber enter the impregnation step after passing through a sealed transport channel containing an inert protective gas.

[0017] According to one aspect of the present invention, the ultrasonic field has an ultrasonic power of 800-2000W, a frequency of 20-40kHz, and an action time of 30-120 seconds.

[0018] According to one aspect of the invention, the pressure of the extrusion roller is 0.2-1.0 MPa.

[0019] According to one aspect of the invention, the low temperature is 80-120°C.

[0020] A highly conductive pitch-based carbon fiber prepreg is prepared by the above-described preparation method.

[0021] Advantages of this invention: (1) This invention abandons the idea of ​​simply improving interfacial adhesion and pioneers a synergistic mechanism of providing anchor points through plasma activation and ultrasonically driven nanofiller bridging. It constructs an efficient and stable three-dimensional electron transport network inside the asphalt-based carbon fiber and resin matrix composite material, and utilizes quantum tunneling effect and direct contact conductivity to make the overall conductivity of the composite material close to the intrinsic value of the fiber. (2) The continuous process design of plasma etching-inert gas protection-ultrasonic wetting ensures that the highly active surface energy of the fiber is maximized by the conductive slurry, avoiding performance loss caused by process interruption. (3) The obtained high-conductivity carbon fiber prepreg has ultra-high conductivity, spatial environment stability and lightweight characteristics. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] A highly conductive pitch-based carbon fiber prepreg and its preparation method include the following steps:

[0024] Conductive nanofillers are dispersed in cyanate ester resin to form a conductive resin slurry;

[0025] Under working gas, pitch-based carbon fiber bundles or fabrics are mechanically and airflow-combined to spread, preheated and dehumidified, and then continuously and uniformly passed through an atmospheric pressure plasma treatment chamber.

[0026] Under inert gas protection, the treated pitch-based carbon fiber bundles or fabrics are impregnated in conductive resin slurry under an applied ultrasonic field to form a preliminary three-dimensional conductive network skeleton.

[0027] After impregnation, the fibers are extruded by extrusion rollers to remove excess resin and air bubbles, and then pre-cured at low temperature to form a stable three-dimensional conductive network skeleton, thus obtaining a highly conductive pitch-based carbon fiber prepreg.

[0028] In practical applications, conductive nanofillers include multi-walled carbon nanotubes and graphene nanosheets.

[0029] In practical applications, the preferred mass ratio of multi-walled carbon nanotubes to graphene nanosheets is 1:1 to 3:1.

[0030] In practical applications, the total amount of conductive nanofiller added is 0.5%-50% of the low viscosity cyanate resin, etc.

[0031] In practical applications, the dispersion step includes: using a high-speed shear mixer at a speed of 2000-5000 rpm and probe-type ultrasonic waves with a power of 300-800W and a frequency of 20-40Hz for 20-60 minutes to ensure that the nanofiller is fully dispersed and not damaged by excessive shearing.

[0032] In practical applications, the fiber spreading step is as follows: a multi-roller stretching fiber spreading device combined with a turbulent air nozzle array is used to spread the pitch-based carbon fiber filaments or fabrics into a thinner state.

[0033] Mechanical fiber spreading is achieved by using 7-11 sets of metal rollers with varying diameters. The front section is a small-diameter high-tension roller (15-25mm in diameter), and the rear section is a large-diameter shaping roller (40-60mm in diameter). The difference in linear velocity between the roller surfaces is 1.05-1.30, which allows the fiber bundle to slide and spread laterally while being stretched longitudinally.

[0034] Compressed air of 0.2-0.6MPa is used for airflow fiber spreading. The air is sprayed onto the fiber surface at an angle of 30°-45° through a slit nozzle, forming a high-frequency micro-vibration airflow field to assist in the separation of fiber monofilaments.

[0035] After the fibers are spread, the width of the filament bundle is controlled at 2.5-4 times the original width, the thickness uniformity deviation is ≤±8%, and the single filament breakage rate is less than 3%.

[0036] In practical applications, the preheating and dehumidification steps are as follows: the spread fibers are placed in an infrared-hot air composite heating channel and continuously preheated and dehydrated in a working gas atmosphere.

[0037] The working gas is dry air, nitrogen, or a mixture of the two in a volume ratio of 1:1 to 3:1, with a dew point ≤ -40℃;

[0038] The preheating temperature is set to 80-120℃, the heating zone length is 1.0-2.5m, and the fiber residence time is 15-40s;

[0039] A segmented temperature control method is adopted: the first segment of 60-80℃ is used for surface moisture evaporation, and the second segment of 100-120℃ is used for internal residual moisture removal and fiber surface energy activation;

[0040] After treatment, the fiber moisture content is ≤0.03%, and the surface temperature fluctuation is controlled within ±3℃ to avoid bubbles or weak interfacial bonding during resin impregnation.

[0041] In practical applications, pitch-based carbon fiber bundles or fabrics are spread, preheated and dehumidified, and then continuously and uniformly enter an atmospheric pressure plasma treatment chamber with working gas.

[0042] In practical applications, the working gas in the atmospheric pressure plasma processing chamber is a mixture of argon and oxygen, with oxygen accounting for 1%-10% of the working gas volume and a total gas flow rate of 500-2000 sccm.

[0043] In practical applications, the radio frequency power of the atmospheric pressure plasma treatment chamber is 200-800W, and the treatment time is 2-10 seconds, with the specific treatment time controlled by the fiber travel speed. This treatment method can effectively break the chemical inertness of the fiber surface, significantly increase its surface roughness, and introduce abundant oxygen-containing polar functional groups without significantly damaging the strength of the fiber itself.

[0044] In practical applications, the fiber surface treated by the atmospheric pressure plasma treatment chamber has high reactivity. To prevent the treated fiber from being contaminated or experiencing activity decay when exposed to the atmosphere, the fiber needs to immediately enter a sealed transport channel filled with high-purity inert protective gas after leaving the plasma chamber. Under this protective atmosphere, it directly enters the impregnation process, forming a continuous etching-protection-transfer step to ensure the formation effect of the subsequent nano-bridge structure.

[0045] In practical applications, the high-purity inert protective gas in the sealed transmission channel is preferably nitrogen or argon with a purity of ≥99.999%.

[0046] In practical applications, activated pitch-based carbon fiber bundles or fabrics treated in an atmospheric pressure plasma treatment chamber are impregnated in a treated conductive resin slurry under the protection of an inert gas.

[0047] In practical applications, the impregnation step requires the application of a high-intensity ultrasonic field with an ultrasonic power of 800-2000W, a frequency of 20-40kHz, and an action time of 30-120 seconds.

[0048] In practical applications, the cavitation effect and microjets generated by the ultrasonic field force the low-viscosity resin to penetrate deeply into the fiber bundle and the micro-gap between fibers.

[0049] In practical applications, the cavitation effect generated by the ultrasonic field and the micro-jet drive the conductive nanofiller to move in a directional manner and anchor it on the activated fiber surface and in the narrow gaps between the fibers, forming a large number of nano-conductive bridges that penetrate and connect the barrier layer originally composed of insulating resin, thus initially constructing a three-dimensional conductive network skeleton.

[0050] In practical applications, the impregnated fibers are passed through a set of extrusion rollers with pressure controlled at 0.2-1.0 MPa to remove excess resin and entrained air bubbles, and to promote closer contact between the nanofillers that have been initially bridged between the fibers, forming a more stable three-dimensional conductive network skeleton.

[0051] In practical applications, fibers passing through extrusion rollers are pre-cured at a lower temperature to obtain highly conductive carbon fiber prepregs with specific viscosity and shelf life.

[0052] In practical applications, the preferred pre-curing temperature is 80-120℃.

[0053] Example 1

[0054] Two g of multi-walled carbon nanotubes and one g of graphene nanosheets were dispersed in 100 g of low-viscosity cyanate ester resin. The mixture was then synergistically treated for 40 minutes using a high-speed shear mixer at 3000 rpm and a probe-type ultrasonic wave with a power of 500 W and a frequency of 30 Hz to form a conductive resin slurry. Pitch-based carbon fiber tows were then mechanically and air-flow-combined for fiber spreading, preheating, and dehumidification before being placed in a plasma treatment chamber containing 95% argon and 5% oxygen for 5 seconds; the radio frequency power of the plasma treatment chamber was 500 W. Under a protective atmosphere of nitrogen with a purity ≥99.999%, the plasma-treated pitch-based carbon fiber tows were impregnated in the synergistically treated conductive resin slurry. The ultrasonic field used for impregnation had a power of 1200 W, a frequency of 40 kHz, and a duration of 60 seconds. After impregnation, the fibers were subjected to a 0.6 MPa pressure extrusion roller to remove excess resin and air bubbles, and then pre-cured at 100°C to obtain a highly conductive pitch-based carbon fiber prepreg. The volume conductivity of the high-conductivity pitch-based carbon fiber prepreg was tested using the four-probe method; the electromagnetic shielding effectiveness (SE) was tested at 10 GHz using the waveguide method; and a thermal cycling test was conducted 100 times in the range of -120℃ to +120℃, referring to GJB 150.5A-2009 "Laboratory Environmental Test Methods for Military Equipment Part 5: Temperature Shock Test".

[0055] Example 2

[0056] 1g of graphene nanosheets were dispersed in 100g of low-viscosity cyanate ester resin and synergistically treated for 40 minutes using a high-speed shear mixer at 3000rpm and 500W power under probe-type ultrasonic treatment at 30Hz to form a conductive resin slurry. Pitch-based carbon fiber tows were mechanically and air-flow-combined for fiber spreading, preheating, and dehumidification before being placed in a plasma treatment chamber containing 98% argon and 2% oxygen for 8 seconds; the radio frequency power of the plasma treatment chamber was 300W. In a protective atmosphere of nitrogen with a purity ≥99.999%, the plasma-treated pitch-based carbon fiber tows were impregnated in the synergistically treated conductive resin slurry. The ultrasonic field used for impregnation had an ultrasonic power of 1000W, a frequency of 40kHz, and a duration of 90 seconds. After impregnation, the fibers were subjected to a 0.6MPa pressure extrusion roller to remove excess resin and air bubbles, and then pre-cured at 100℃ to obtain a highly conductive pitch-based carbon fiber prepreg. The volume conductivity of the high-conductivity pitch-based carbon fiber prepreg was tested using the four-probe method; the electromagnetic shielding effectiveness (SE) was tested at 10 GHz using the waveguide method; and a thermal cycling test was conducted 100 times in the range of -120℃ to +120℃, in accordance with GJB150.5A-2009 "Laboratory Environmental Test Methods for Military Equipment Part 5: Temperature Shock Test".

[0057] Example 3

[0058] Two g of multi-walled carbon nanotubes were dispersed in 100 g of low-viscosity cyanate ester resin and co-treated for 40 minutes using a high-speed shear mixer at 3000 rpm and 500 W power under probe-type ultrasonic treatment at 30 Hz to form a conductive resin slurry. Pitch-based carbon fiber tows were then mechanically and air-flow-combined for fiber spreading, preheating, and dehumidification before being placed in a plasma treatment chamber containing 92% argon and 8% oxygen for 3 seconds; the radio frequency power of the plasma treatment chamber was 600 W. In a protective atmosphere of nitrogen with a purity ≥99.999%, the plasma-treated pitch-based carbon fiber tows were impregnated in the co-treated conductive resin slurry using a conventional impregnation method without ultrasonic treatment. After impregnation, the fibers were subjected to a 0.6 MPa pressure extrusion roller to remove excess resin and air bubbles, and then pre-cured at 100°C to obtain a highly conductive pitch-based carbon fiber prepreg. The volume conductivity of the high-conductivity pitch-based carbon fiber prepreg was tested using the four-probe method; the electromagnetic shielding effectiveness (SE) was tested at 10 GHz using the waveguide method; and a thermal cycling test was conducted 100 times in the range of -120℃ to +120℃, referring to GJB 150.5A-2009 "Laboratory Environmental Test Methods for Military Equipment Part 5: Temperature Shock Test".

[0059] Comparative Example 1

[0060] 100g of low-viscosity cyanate ester resin was used as the conductive resin slurry. Pitch-based carbon fiber tows were mechanically and air-flow-combined, preheated, and dehumidified before being impregnated in the conductive resin slurry using conventional impregnation methods without ultrasonic treatment. After impregnation, the fibers were subjected to a 0.6MPa pressure extrusion roller to remove excess resin and air bubbles, followed by pre-curing at 100℃ to obtain a highly conductive pitch-based carbon fiber prepreg. The volume conductivity of the highly conductive pitch-based carbon fiber prepreg was tested using the four-probe method; the electromagnetic shielding effectiveness (SE) was tested at 10GHz using the waveguide method; and a thermal cycling test was conducted 100 times within the -120℃ to +120℃ range, referring to GJB 150.5A-2009 "Laboratory Environmental Test Methods for Military Equipment Part 5: Temperature Shock Test".

[0061] Comparative Example 2

[0062] Two g of multi-walled carbon nanotubes and one g of graphene nanosheets were dispersed in 100 g of T800 carbon fibers. The mixture was then synergistically treated for 40 minutes using a high-speed shear mixer at 3000 rpm and a probe-type ultrasonic wave with a power of 500 W and a frequency of 30 Hz to form a conductive resin slurry. The T800 carbon fiber tow was then mechanically and air-flow-combined for fiber spreading, preheating, and dehumidification before being placed in a plasma treatment chamber containing 95% argon and 5% oxygen for 5 seconds; the radio frequency power of the plasma treatment chamber was 500 W. Under a protective atmosphere of nitrogen with a purity ≥99.999%, the plasma-treated T800 carbon fiber tow was then impregnated in the synergistically treated conductive resin slurry. The ultrasonic field used for impregnation had a power of 1200 W, a frequency of 40 kHz, and a duration of 60 seconds. After impregnation, the fibers were subjected to a 0.6 MPa pressure extrusion roller to remove excess resin and air bubbles, and then pre-cured at 100°C to obtain a highly conductive T800 carbon fiber prepreg. The volume conductivity of the high-conductivity T800 carbon fiber prepreg was tested using the four-probe method; the electromagnetic shielding effectiveness (SE) was tested at 10 GHz using the waveguide method; and a thermal cycling test was conducted 100 times in the range of -120℃ to +120℃, referring to GJB 150.5A-2009 "Laboratory Environmental Test Methods for Military Equipment Part 5: Temperature Shock Test".

[0063] Comparative Example 3

[0064] Two g of multi-walled carbon nanotubes and one g of graphene nanosheets were dispersed in 100 g of T800 carbon fibers and subjected to electrochemical treatment to form a conductive resin slurry. The electrochemical treatment included a primary electrochemical surface treatment of the carbon fibers using an acidic electrolyte containing inorganic acidic ammonium salts and a secondary electrochemical surface treatment using a compound electrolyte containing inorganic alkaline ammonium salts and amino compounds, resulting in surface-modified carbon fibers. These surface-modified carbon fibers were then impregnated with a resin film to obtain a carbon fiber prepreg. Under a nitrogen atmosphere with a purity ≥99.999%, the electrochemically treated pitch-based carbon fiber tow was impregnated in the synergistically treated conductive resin slurry. The ultrasonic field used for impregnation had an ultrasonic power of 1200 W, a frequency of 40 kHz, and a duration of 60 seconds. After impregnation, the fibers were subjected to a 0.6 MPa pressure extrusion roller to remove excess resin and air bubbles, and then pre-cured at 100°C to obtain a highly conductive pitch-based carbon fiber prepreg. The volume conductivity of the high-conductivity pitch-based carbon fiber prepreg was tested using the four-probe method; the electromagnetic shielding effectiveness (SE) was tested at 10 GHz using the waveguide method; and a thermal cycling test was conducted 100 times in the range of -120℃ to +120℃, referring to GJB 150.5A-2009 "Laboratory Environmental Test Methods for Military Equipment Part 5: Temperature Shock Test".

[0065] The test data obtained for Examples 1-3 and Comparative Examples 1-3 are shown in Table 1 below:

[0066] Table 1

[0067]

[0068] From the data in Table 1 above, we can see that:

[0069] (1) Example 1 demonstrates the effect of the optimal solution of the present invention. The volume conductivity and shielding effectiveness are far superior to the control example. The high conductivity retention rate after thermal cycling indicates that the pitch-based carbon fiber prepreg of Example 1 has excellent stability.

[0070] (2) Compared with Example 1, which only used graphene, Example 2 still has excellent performance but is slightly lower than the synergistic filler in Example 1, which illustrates the necessity of multi-walled carbon nanotubes and graphene nanosheets as synergistic fillers.

[0071] (3) In Example 3, ultrasonic assistance was omitted compared to Example 1. The conductivity of the pitch-based carbon fiber prepreg prepared in Example 3 decreased significantly, which proves that ultrasonic assistance is an indispensable key step for constructing nanobridges and three-dimensional networks. Ultrasonic assistance was used instead of simple dispersion.

[0072] (4) Comparative Example 2 used the same process as Example 1, but the fiber was replaced with T800 carbon fiber with poor intrinsic conductivity. The final performance was much lower than that of Example 1, which shows that the use of pitch-based carbon fiber helps to improve the performance of carbon fiber prepreg.

[0073] (5) In Comparative Example 3, the electrochemical treatment method was used instead of plasma treatment, and the performance of the obtained pitch-based carbon fiber prepreg was significantly reduced and the retention rate after thermal cycling was low.

[0074] Advantages of this invention: (1) This invention abandons the idea of ​​simply improving interfacial adhesion and pioneers a synergistic mechanism of providing anchor points through plasma activation and ultrasonically driven nanofiller bridging. It constructs an efficient and stable three-dimensional electron transport network inside the asphalt-based carbon fiber and resin matrix composite material, and utilizes quantum tunneling effect and direct contact conductivity to make the overall conductivity of the composite material close to the intrinsic value of the fiber. (2) The continuous process design of plasma etching-inert gas protection-ultrasonic wetting ensures that the highly active surface energy of the fiber is maximized by the conductive slurry, avoiding performance loss caused by process interruption. (3) The obtained high-conductivity carbon fiber prepreg has ultra-high conductivity, spatial environment stability and lightweight characteristics.

[0075] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a highly conductive pitch-based carbon fiber prepreg, characterized in that, The preparation method of the highly conductive pitch-based carbon fiber prepreg includes the following steps: Conductive nanofillers are dispersed in cyanate ester resin to form a conductive resin slurry; After being mechanically and air-flowed, preheated and dehumidified, pitch-based carbon fiber bundles or fabrics are continuously and uniformly passed through an atmospheric pressure plasma treatment chamber with working gas. The radio frequency power of the atmospheric pressure plasma treatment chamber is 200-800W, and the treatment time is 2-10 seconds. Under the protection of inert gas, the treated pitch-based carbon fiber filaments or fabrics are impregnated in a conductive resin slurry under an applied ultrasonic field to form a preliminary three-dimensional conductive network skeleton. The ultrasonic power of the ultrasonic field is 800-2000W, the frequency is 20-40kHz, and the duration is 30-120 seconds. After impregnation, the fibers are extruded by extrusion rollers to remove excess resin and air bubbles, and then pre-cured at low temperature to form a stable three-dimensional conductive network skeleton, thus obtaining a highly conductive pitch-based carbon fiber prepreg. The low temperature is 80-120℃. The conductive nanofiller includes multi-walled carbon nanotubes and graphene nanosheets; the total amount of the conductive nanofiller added is 0.5%-50% of the mass of the cyanate ester resin.

2. The method for preparing the highly conductive pitch-based carbon fiber prepreg according to claim 1, characterized in that, The dispersion step includes: using a high-speed shear mixer to co-process the mixture for 20-60 minutes under probe-type ultrasonic waves at a speed of 2000-5000 rpm and a power of 300-800W with a frequency of 20-40Hz.

3. The method for preparing the highly conductive pitch-based carbon fiber prepreg according to claim 1, characterized in that, The working gas is a mixture of argon and oxygen, with oxygen accounting for 1%-10% of the working gas volume.

4. The method for preparing the highly conductive pitch-based carbon fiber prepreg according to claim 1, characterized in that, The fibers treated in the atmospheric pressure plasma treatment chamber are then transported through a sealed transmission channel containing inert protective gas before entering the impregnation step.

5. The method for preparing the highly conductive pitch-based carbon fiber prepreg according to claim 1, characterized in that, The pressure of the extrusion roller is 0.2-1.0 MPa.

6. A highly conductive pitch-based carbon fiber prepreg, characterized in that, It is prepared by the preparation method described in any one of claims 1-5.

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