Highly heat-conductive porous carbon skeleton material, and preparation method and application thereof

Abstract

The application discloses a kind of high-thermal-conductivity porous carbon skeleton materials and preparation method and application thereof, belong to the technical field of heat-conducting composite material.The method comprises the following steps: immerse C / C composite material in phenolic resin precursor solution containing expandable microspheres, carry out vacuum impregnation treatment, obtain impregnated composite material;Impregnated composite material is sequentially subjected to mold foaming treatment, heating curing treatment, normal pressure drying treatment, carbonization treatment, chemical vapor deposition treatment and high-temperature heat treatment, and high-thermal-conductivity porous carbon skeleton material is prepared;Wherein, expandable microspheres are acrylic polymer microspheres containing closed liquid alkane gas.By thermoplastic foaming, multi-level pore structure is accurately constructed, combined with chemical vapor deposition and high-temperature graphitization treatment, active regulation of carbon skeleton pore size and high-order crystal structure are realized, and the contradiction that traditional porous carbon material is difficult to consider high specific surface area and high mass transfer is solved, and the thermal conductivity and structural designability are significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of thermally conductive porous materials technology, specifically relating to a high thermal conductivity porous carbon skeleton material, its preparation method, and its application. Background Technology

[0002] Carbon / carbon (C / C) porous thermally conductive frameworks possess excellent thermal conductivity and high-temperature stability due to their intrinsic three-dimensional continuous carbon network structure. Their open pore system and large specific surface area make them ideal multifunctional composite platforms, allowing for melt-infiltration composites with metals, polymers, or phase change materials to create next-generation composite materials with superior comprehensive properties. However, porous carbon frameworks prepared by currently widely used physical or chemical activation methods still have significant limitations in terms of structural control. These methods typically rely on highly random corrosion or gas etching processes, resulting in excessively wide pore size distributions, poor structural uniformity, and pore morphology dominated by narrow and tortuous micropores. This disordered and difficult-to-control pore structure severely restricts material performance: on the one hand, while micropores contribute a high specific surface area, they significantly increase fluid transport resistance, hindering the effective penetration and uniform distribution of functional substances (such as molten metals, polymer monomers, or phase change media); on the other hand, the unpredictability of the pore structure also challenges the reproducibility and reliability of material properties. More importantly, when such porous carbon frameworks with a single structure are used as reinforcing phases in composites with other matrix materials, their simple porous system cannot achieve true functional gradient design. For example, when composited with polymers or phase change materials, the single pore size cannot simultaneously optimize impregnation efficiency, interfacial bonding strength, and the transport dynamics of functional molecules, resulting in the final composite material struggling to maintain stable performance under harsh conditions such as high power, high load, or long-term cycling. Therefore, developing novel C / C porous thermally conductive frameworks with multi-scale, multi-level pore structures is key to realizing next-generation high-performance composite functional materials and an inevitable path to breaking through current material design bottlenecks.

[0003] Studies have shown that precise control and surface modification of the pore structure of preforms are key prerequisites for achieving uniform impregnation of the phenolic resin matrix within the framework, good interfacial bonding, and the final formation of an ideal carbon structure, which is crucial for improving the overall performance of composite materials. However, although the pore structure of phenolic resin-based carbon materials after carbonization can be controlled to some extent by adjusting the raw material molar ratio, curing agent proportion, or introducing pore-forming agents, these methods are usually limited to the construction of single-scale pore sizes, making it difficult to achieve the synergistic construction of a multi-level pore system spanning macro-meso-micro scales. Therefore, single-pore-size porous carbon thermal conductive frameworks often perform poorly in complex applications requiring both high mass transfer efficiency and high interfacial activity. They cannot simultaneously achieve the organic combination of "rapid transport channels" and "fully reactive interfaces" within the same structure, severely limiting their practical application potential in high-end integrated thermal management and functional systems. Overcoming this bottleneck requires multi-level pore design across scales to maximize the active interface while maintaining good transport performance, thereby achieving a leapfrog improvement in material performance.

[0004] To address the aforementioned issues, existing technologies have attempted to construct porous carbon frameworks using various methods. For example, Chinese patent application CN118420374A discloses a method for preparing porous carbon-assisted ZrC-modified C / C composite materials. This method involves sol-gel coagulation, curing, carbonization, and subsequent combination with CVI PyC to obtain a porous carbon matrix with a uniform pore structure and high thermal stability, solving the technical problems of easy collapse of porous frameworks and poor overall thermal control of composite materials. However, the porous carbon framework constructed by this method mainly consists of pores formed by the carbonization of resorcinol-formaldehyde resin. Although the pore size and distribution can be controlled to some extent by adjusting the precursor ratio, it is essentially limited to single-scale pores formed by resin carbonization, making it difficult to achieve the synergistic construction of a multi-scale macro-meso-micro multi-level pore system. Therefore, when facing complex application scenarios that require both high mass transfer efficiency and high interfacial activity, the single pore size structure of this framework limits further performance improvement. Chinese patent application CN119263865A discloses a high thermal conductivity carbon skeleton resin-based composite material and its preparation method. This method involves in-situ growth of carbon nanotubes on chopped mesophase pitch-based carbon fibers via chemical vapor deposition, followed by the deposition of pyrolytic carbon. This constructs a high thermal conductivity hybrid carbon skeleton composed of carbon fibers, carbon nanotubes, and pyrolytic carbon, significantly improving the thermal conductivity of the composite material in the thickness direction. The core of this method lies in constructing a three-dimensional thermally conductive network. However, the pore structure of the carbon skeleton mainly depends on the random channels formed by the stacking of chopped carbon fibers and the filling of carbon nanotubes / pyrolytic carbon within them. It does not actively design and control the morphology, size, and distribution of the pores across scales. The randomness and uniformity of its pore structure make it unsuitable as an ideal multifunctional composite platform, failing to simultaneously meet the dual requirements of efficient mass transfer and high interfacial reactivity. Therefore, developing a novel C / C porous thermally conductive skeleton with a cross-scale, multi-level pore structure capable of achieving synergistic effects of efficient mass transfer and highly reactive interfaces is crucial for realizing next-generation high-performance composite functional materials and is an inevitable path to overcome current material design bottlenecks. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a high thermal conductivity porous carbon framework material, its preparation method and application, so as to solve the technical problem of how to construct a multi-level porous C / C thermally conductive framework with precisely controllable pore structure and both efficient mass transfer channels and highly active interfaces.

[0006] To achieve the above objectives, the present invention employs the following technical solution: This invention discloses a method for preparing a highly thermally conductive porous carbon framework material, comprising the following steps: The C / C composite material was immersed in a phenolic resin precursor solution containing expandable microspheres and subjected to vacuum impregnation to obtain the impregnated composite material. The impregnated composite material was then subjected to molding foaming, heating curing, atmospheric pressure drying, carbonization, chemical vapor deposition, and high temperature heat treatment to obtain a high thermal conductivity porous carbon skeleton material. Among them, the expandable microspheres are acrylic polymer microspheres containing enclosed liquid alkane gas.

[0007] Preferably, the conditions for vacuum impregnation treatment include: pressure below 0.09 MPa and holding time of 30 to 40 min.

[0008] Preferably, the conditions for compression molding foaming treatment include: pressure of 0.2~0.5 MPa, foaming temperature of 70~90℃, and foaming time of 5~20 min; The conditions for heat curing treatment include: temperature of 70~90℃ and time of 24~48 h; The conditions for atmospheric pressure drying include: temperature of 80~100℃ and time of 10~24 h.

[0009] Preferably, the carbonization conditions include: heating to 800-1100°C at a heating rate of 2-5°C / min under an argon atmosphere, and holding at that temperature for 2-4 hours.

[0010] Preferably, the chemical vapor deposition (CVD) conditions include: using argon as a protective gas, heating to 900-1100°C at a heating rate of 1-5°C / min, followed by introducing CH4 to deposit pyrolytic carbon for 30-300 min, and cooling to room temperature; the argon flow rate is 1-3 L / min during the heating and cooling processes; the argon flow rate is 2-5 L / min during CH4 deposition; and the number of cycles for depositing pyrolytic carbon is 5-8.

[0011] Preferably, the conditions for high-temperature heat treatment include: heating to 1600-2500°C in an argon atmosphere at a heating rate of 5-10°C / min for 2-3 hours.

[0012] Preferably, the phenolic resin precursor solution containing expandable microspheres has a mass fraction of 0.5 wt% to 2.5 wt%; the expandable microspheres are mixed in the phenolic resin precursor solution by magnetic stirring for 20 to 40 min to obtain the phenolic resin precursor solution containing expandable microspheres.

[0013] More preferably, the method for preparing the phenolic resin precursor solution is as follows: resorcinol and formaldehyde solution are dissolved in deionized water, hexadecyltrimethylammonium bromide is added, and the mixture is magnetically stirred for 10-40 min to obtain the phenolic resin precursor solution. The ratio of resorcinol, formaldehyde solution, deionized water and hexadecyltrimethylammonium bromide is (12.0~15.0) g : (17.4~21.7) g : (18.0~22.5) mL : (0.036~0.06) g.

[0014] This invention discloses a high thermal conductivity porous carbon framework material, which is prepared by the above-mentioned method for preparing high thermal conductivity porous carbon framework materials.

[0015] This invention discloses the application of the above-mentioned high thermal conductivity porous carbon framework material in thermal management of high-power electronic devices or thermal protection systems for aerospace.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a method for preparing a highly thermally conductive porous carbon framework material. The impregnation step ensures that the resin solution containing expandable microspheres uniformly enters the interior of the C / C composite material; the molding and foaming step forms a uniform microsphere expansion body under physical constraints; the curing step locks the morphology of the expanded microspheres within the cross-linked resin network; the carbonization step transforms the organic framework into a carbon framework; the chemical vapor deposition step reinforces the pore walls and connects the carbon fibers by depositing pyrolytic carbon; and the high-temperature heat treatment step achieves graphitization transformation, improving thermal conductivity. The physical constraints provided by molding guide the coordinated and uniform expansion of the expandable microspheres, avoiding pore wall rupture and disordered pore sizes caused by free foaming; subsequent multi-step processes gradually transform the foamed structure into a reinforced, graphitized three-dimensional network framework, achieving a fundamental shift from random pore formation to active design. This successfully constructs a three-dimensional porous carbon-based framework material with precisely controllable pore structure, high specific surface area, and excellent thermal stability, overcoming the problems of wide pore size distribution, random and simple structure, and low mass transfer efficiency of traditional methods. Expandable microspheres are acrylic polymer microspheres containing closed liquid alkane gas. This specific choice makes the formation of pore structure no longer dependent on random corrosion, but achieves active design and controllable construction of material pore density, pore size distribution and pore morphology through thermoplastic foaming, solving the fundamental problem that traditional methods are difficult to achieve in terms of structural control.

[0017] This invention discloses a high thermal conductivity porous carbon framework material, comprising carbon fibers, phenolic resin carbon, and pyrolytic carbon, forming a three-dimensional network framework with a hierarchical porous structure and high crystal orientation. Carbon fibers provide continuous thermally conductive channels and mechanical support for the framework; phenolic resin carbon forms a hierarchical porous structure through a foaming process, contributing specific surface area and pore system; pyrolytic carbon is deposited on the framework using chemical vapor deposition, enhancing pore wall strength and connecting the interface between carbon fibers and resin carbon. The hierarchical porous structure includes mesopores, macropores, or through-pores formed by expanding microspheres. By introducing a resin solution containing thermoplastic expandable microspheres into the porous carbon matrix, the hierarchical porous structure can be controllably constructed. By systematically adjusting key parameters such as the amount of expandable microspheres added, foaming pressure, foaming temperature, and foaming time, the size, density, and spatial distribution of mesopores, macropores, and even through-pores in the final carbon framework can be directionally controlled. Mesopores provide high specific surface area, serving as active interface regions; macropores and through-pores provide rapid mass transfer channels, reducing fluid transport resistance. This multi-level collaborative and integrated pore structure design effectively solves the contradiction between high specific surface area and efficient mass transfer in traditional porous materials, enabling the material to maximize the active interface while maintaining good transport performance.

[0018] This invention discloses the application of a highly thermally conductive porous carbon framework material in thermal management of high-power electronic devices or aerospace thermal protection systems. Through high-temperature heat treatment, carbon atoms gain sufficient kinetic energy under thermal excitation to migrate and rearrange, achieving a transformation from a disordered layered structure to a highly ordered graphite crystal. During this process, the originally disordered sp atoms in the porous carbon material... 3 The hybrid carbon structure gradually transforms into an ordered sp... 2 Hybrid graphite microcrystals, with increased grain size and improved stacking order, construct continuous and complete high-efficiency phonon transport channels. This highly ordered graphite crystal significantly reduces phonon scattering, resulting in a substantial improvement in the material's intrinsic thermal conductivity, meeting the stringent requirements for thermal conductivity in extreme conditions such as high-power electronic devices and aerospace thermal protection systems. Simultaneously, high-temperature treatment significantly purifies the bulk and surface structure of the carbon skeleton, improving the material's chemical and thermal stability in high-temperature and highly corrosive environments. When used in high-power electronic devices, heat can rapidly diffuse along the three-dimensional thermal conductivity network, effectively reducing hotspot temperatures and preventing localized overheating. The porous structure imparts low-density properties, meeting the lightweight requirements of electronic devices without adding extra weight. Carbon fibers provide mechanical support, while the carbon skeleton provides thermal insulation and ablation resistance, achieving an integrated design of thermal protection and structural load-bearing, meeting the urgent needs of the aerospace field for lightweight and efficient thermal protection materials. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the preparation process of a high thermal conductivity porous carbon framework material according to the present invention. Figure 2 The image shows the morphology of the high thermal conductivity porous carbon framework material prepared in Example 1. Figure 3 This is a morphology diagram of the high thermal conductivity porous carbon framework material prepared in Example 6; Figure 4 The image shows the morphology of the high thermal conductivity porous carbon framework material prepared in Comparative Example 1. Figure 5 The image shows the XPS spectrum of the high thermal conductivity porous carbon framework material obtained in Example 6 after high-temperature heat treatment. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0021] Unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0022] Unless otherwise specified, all the technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0023] In this invention, unless otherwise specified, percentage (%) or parts refer to weight percentage or parts relative to the composition.

[0024] In this invention, unless otherwise specified, the components involved or their preferred components can be combined to form new technical solutions.

[0025] In this invention, unless otherwise specified, the numerical range "a~b" is an abbreviation for any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "6~22" indicates that the text already includes real numbers between "6~22", and "6~22" is simply an abbreviation for these numerical combinations.

[0026] The "scope" disclosed in this invention can be in the form of a lower limit and an upper limit, and can be one or more lower limits and one or more upper limits, respectively.

[0027] In this invention, the term "and / or" as used herein refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations.

[0028] Unless otherwise stated, the technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods or materials similar to or equivalent to those described herein may also be used in this invention.

[0029] This invention provides a method for preparing a highly thermally conductive porous carbon framework material, comprising the following steps: Low-density C / C composite materials (density 1.2~1.4 g / cm³) were used. 3 The carbon skeleton is immersed in a phenolic resin precursor solution containing expandable microspheres, and then heated and cured sequentially to achieve molding foaming and drying. A thermally conductive carbon skeleton with a multi-level porous structure is prepared by carbonization process. Then, pyrolytic carbon is deposited by chemical vapor deposition process. The pyrolytic carbon is used to further control the pore size and connect the carbon fibers in the preform. Finally, a porous carbon skeleton with a highly crystalline orientation structure is obtained by high-temperature heat treatment.

[0030] The introduction of expandable microspheres involves adding 0.5 wt% to 2.5 wt% of expandable microspheres to a phenolic resin precursor solution, stirring and mixing to obtain an initial solution; the stirring method is magnetic stirring for 20 to 40 minutes. The expandable microspheres are acrylic polymer microspheres containing enclosed liquid alkane gas.

[0031] The phenolic resin precursor solution was prepared as follows: resorcinol and formaldehyde solution were dissolved in deionized water, hexadecyltrimethylammonium bromide was added, and the mixture was stirred to obtain the phenolic resin precursor solution. The stirring was performed using magnetic stirring for 10–40 minutes. The formaldehyde solution had a mass concentration of 37.5 wt%.

[0032] The ratio of resorcinol, formaldehyde solution, deionized water and hexadecyltrimethylammonium bromide is (12.0~15.0) g : (17.4~21.7) g : (18.0~22.5) mL : (0.036~0.06) g.

[0033] The curing process is carried out in an oven at a temperature of 70-90°C for 24-48 hours. A certain pressure is applied during curing and foaming, ranging from 0.2 to 0.5 MPa. Drying is carried out at atmospheric pressure and 80-100°C for 10-24 hours.

[0034] The carbonization parameters include: heating to 800-1100℃ at a rate of 2-5℃ / min under an argon atmosphere, and holding at that temperature for 2-4 hours.

[0035] The parameters for the deposition of pyrolytic carbon are as follows: A porous thermally conductive C / C composite material with a framework is placed in a vertical CVD furnace. Argon is used as the protective gas, and the heating equipment is heated to 900-1100°C at a heating rate of 1-5°C / min. Then, CH4 is introduced to deposit pyrolytic carbon (PyC) for 30-300 min. After cooling to room temperature, a porous carbon matrix is ​​obtained. During the heating and cooling processes, the argon flow rate is 1-3 L / min; during CH4 deposition, the argon flow rate is 2-5 L / min. The deposition cycle is 5-8 times to obtain the carbon matrix containing the pyrolytic carbon framework.

[0036] The heat treatment parameters are as follows: in an argon atmosphere, the temperature is increased to 1600~2500℃ at a heating rate of 5~10 ℃ / min, and heated for 2~3 h.

[0037] The high thermal conductivity porous carbon skeleton material disclosed in this invention is a three-dimensional network skeleton with a hierarchical porous structure and high crystal orientation, composed of carbon fibers, phenolic resin carbon and pyrolytic carbon; the hierarchical porous structure includes mesopores, macropores or through pores formed by expanding microsphere foaming.

[0038] This invention discloses a method for preparing a high thermal conductivity porous carbon framework material. This method organically combines multiple steps including resin impregnation, curing, foaming, carbonization, chemical vapor deposition (CVD), and high-temperature graphitization to successfully construct a three-dimensional porous carbon-based framework material with precisely controllable pore structure, high specific surface area, and excellent thermal stability. Specifically, a carbon fiber preform is impregnated with a precursor resin. The foaming process is precisely controlled, followed by high-temperature carbonization to remove non-carbon elements and initially form a carbon framework. Further, pyrolytic carbon is deposited inside the pores using CVD, strengthening the pore walls and densifying the structure. Finally, high-temperature heat treatment achieves the graphitization transformation of the carbon material, significantly improving its thermal conductivity. The core of this method lies in the precise control of key parameters during the foaming stage (such as the type and content of the foaming agent, temperature, pressure, and time), enabling the active design and controllable construction of the material's pore density, pore size distribution, and pore morphology. This overcomes the problems of wide pore size distribution, random and monotonous structure, and low mass transfer efficiency found in traditional porous carbon materials.

[0039] Furthermore, by introducing a resin solution containing thermoplastic expandable microspheres into a porous carbon matrix, the controllable construction of a hierarchical porous structure can be achieved. By systematically adjusting key parameters such as the amount of expandable microspheres added, foaming pressure, foaming temperature, and foaming time, the size, density, and spatial distribution of mesopores, macropores, and even through-pores in the final carbon framework can be directionally controlled. This multi-level, synergistic, and integrated pore structure design effectively solves the contradiction between high specific surface area and efficient mass transfer in traditional porous materials, making this material an ideal high-performance thermally conductive framework. It is particularly suitable for cutting-edge fields such as thermal management of high-power electronic devices, aerospace thermal protection systems, heat exchange units in high-temperature processing equipment, and high-efficiency energy conversion systems, providing an innovative material solution for addressing heat dissipation and thermal control challenges under extreme operating conditions.

[0040] Furthermore, through high-temperature heat treatment, carbon atoms gain sufficient kinetic energy under thermal excitation to migrate and rearrange, achieving a transformation from a disordered layered structure to highly ordered graphite crystals. During this process, the originally disordered sp atoms in the porous carbon material... 3 The hybrid carbon structure gradually transforms into an ordered sp... 2 Hybrid graphite microcrystals, with their increased grain size and improved stacking order, construct continuous and highly efficient phonon transport channels. The highly ordered graphite crystals significantly reduce phonon scattering, resulting in a substantial increase in the material's intrinsic thermal conductivity, meeting the stringent requirements for thermal conductivity in extreme applications such as high-power electronic devices and aerospace thermal protection systems. Meanwhile, as... Figure 5 As shown, under high-temperature conditions, residual heteroatoms (such as hydrogen, oxygen, nitrogen, and sulfur) and unstable surface functional groups (such as carboxyl-COOH and hydroxyl-OH) in the material are pyrolyzed and removed as gaseous small molecules such as H2O, CO, CO2, and CH4, thereby significantly purifying the bulk and surface structure of the carbon framework. This process not only reduces lattice defects and improves the crystal integrity and thermal conductivity of the material, but also greatly enhances the chemical and thermal stability of the porous carbon framework under harsh environments such as high temperature and strong corrosion. This lays a solid foundation for its long-term reliable application as a high thermal conductivity carbon-based framework in fields such as high-efficiency thermal management devices, high-power electronic packaging, and aerospace thermal protection systems.

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0042] Example 1 A method for preparing a highly thermally conductive porous carbon framework material includes the following steps: Step 1: Dissolve 12.0 g of resorcinol and 17.4 g of 37.5 wt% formaldehyde solution in 18.0 mL of deionized water to obtain a mixture; then add 0.036 g of cetyltrimethylammonium bromide (CTAB) to the mixture, and magnetically stir the suspension for 10 min to obtain a transparent precursor solution; add 0.5 wt% expandable microspheres to the phenolic resin precursor solution, and magnetically stir for 20 min to obtain the initial solution.

[0043] Step 2: Immerse the low-density C / C composite material in the initial solution obtained in Step 1, so that the block is completely submerged, and then place it in a vacuum drying oven. Evacuate the oven until the pressure inside is below 0.09 MPa and maintain it for 40 minutes. Then, it undergoes heating curing, microsphere expansion, normal pressure drying, and carbonization.

[0044] The heating, curing, microsphere expansion, atmospheric pressure drying, and carbonization process is as follows: The low-density C / C composite material is placed in an oven at 60℃ and preheated for 20 minutes; it is then foamed by compression molding at 0.3 MPa and 70℃ for 5 minutes. After stopping the pressure application, heating and curing continue for 24 hours; subsequently, it is dried at 80℃ under atmospheric pressure for 10 hours; finally, it is placed in a tube furnace and heated to 800℃ at a rate of 2℃ / min, held for 2 hours, with argon gas purging throughout as a protective gas to decompose the phenolic resin in the composite material into carbon.

[0045] Step 3: Place the carbonized sample in a CVD furnace, use argon as a protective gas, and heat the equipment to 900°C at a heating rate of 3°C / min. Then, introduce CH4 to deposit PyC for 40 min, and repeat the deposition cycle 5 times.

[0046] The carbon deposition pyrolysis process is as follows: the argon flow rate is set to 1L / min during the heating and cooling process, the carbon deposition pyrolysis process is 2L / min, and the CH4 flow rate is 70L / min; then the temperature is cooled to room temperature to obtain a porous carbon matrix.

[0047] Step 4: Place the obtained porous carbon matrix in a high-temperature furnace for heat treatment to obtain a high thermal conductivity porous C / C composite material.

[0048] The heat treatment process for the composite material is as follows: the dried composite material is placed in a high-temperature furnace, argon is introduced as a protective gas, and the equipment is heated to 1600℃ for 2 hours at a heating rate of 5℃ / min, so that the phenolic resin-based amorphous carbon is transformed into a highly oriented crystal structure.

[0049] Example 2 A method for preparing a highly thermally conductive porous carbon framework material includes the following steps: Step 1: Dissolve 13.0 g of resorcinol and 18.8 g of 37.5 wt% formaldehyde solution in 19.5 mL of deionized water to obtain a mixture; then add 0.039 g of CTAB to the mixture and magnetically stir the suspension for 15 min to obtain a transparent precursor solution; add 1.0 wt% expandable microspheres to the phenolic resin precursor solution and magnetically stir for 20 min to obtain the initial solution.

[0050] Step 2: Immerse the low-density C / C in the initial solution obtained in Step 1, so that the block is completely submerged, and then place it in a vacuum drying oven. Evacuate the oven until the pressure inside is below 0.09 MPa and maintain for 35 minutes. Then, heat curing and microsphere expansion, normal pressure drying and carbonization are carried out.

[0051] The heating, curing, microsphere expansion, atmospheric pressure drying, and carbonization process is as follows: The low-density C / C composite material is placed in an oven at 60℃ and preheated for 20 minutes; then, it is foamed by compression molding at 0.3 MPa and 75℃ for 10 minutes. After stopping the pressure application, heating and curing continue for 24 hours; subsequently, it is dried at 90℃ under atmospheric pressure for 10 hours; finally, it is placed in a tube furnace and heated to 900℃ at a rate of 3℃ / min, held for 2 hours, with argon gas purging throughout as a protective gas to decompose the phenolic resin in the composite material into carbon.

[0052] Step 3: Place the carbonized sample in a CVD furnace, use argon as a protective gas, and heat the equipment to 950°C at a heating rate of 4°C / min. Then, introduce CH4 to deposit PyC for 80 min, and repeat the deposition cycle 6 times.

[0053] The carbon deposition pyrolysis process is as follows: the argon flow rate is set to 2L / min during the heating and cooling process, the argon flow rate is 5L / min during the carbon deposition pyrolysis process, and the CH4 flow rate is 90L / min; then the temperature is cooled to room temperature to obtain a porous carbon matrix.

[0054] Step 4: Place the obtained porous carbon matrix in a high-temperature furnace for heat treatment to obtain a high thermal conductivity porous C / C composite material.

[0055] The heat treatment process for the composite material is as follows: the dried composite material is placed in a high-temperature furnace, argon is introduced as a protective gas, and the equipment is heated to 1800℃ for 2 hours at a heating rate of 5℃ / min, so that the phenolic resin-based amorphous carbon is transformed into a highly oriented crystal structure.

[0056] Example 3 A method for preparing a highly thermally conductive porous carbon framework material includes the following steps: Step 1: Dissolve 14.0 g of resorcinol and 20.3 g of 37.5 wt% formaldehyde solution in 21.0 mL of deionized water to obtain a mixture; then add 0.042 g of CTAB to the mixture and magnetically stir the suspension for 20 min to obtain a transparent precursor solution; add 1.5 wt% expandable microspheres to the phenolic resin precursor solution and magnetically stir for 25 min to obtain the initial solution.

[0057] Step 2: Immerse the low-density C / C in the initial solution obtained in Step 1, so that the block is completely submerged, and then place it in a vacuum drying oven. Evacuate the oven until the pressure inside is below 0.09 MPa and maintain for 30 minutes. Then, heat curing and microsphere expansion, normal pressure drying and carbonization are carried out.

[0058] The heating, curing, microsphere expansion, atmospheric pressure drying, and carbonization process is as follows: The low-density C / C composite material is placed in an oven at 60℃ and preheated for 25 minutes; it is then foamed by compression molding at 0.4 MPa and 80℃ for 15 minutes. After stopping the pressure application, heating and curing continue for 30 hours; subsequently, it is dried at 80℃ under atmospheric pressure for 15 hours; finally, it is placed in a tube furnace and heated to 900℃ at a rate of 2℃ / min, held for 3 hours, with argon gas purging throughout as a protective gas to decompose the phenolic resin in the composite material into carbon.

[0059] Step 3: Place the carbonized sample in a CVD furnace, use argon as a protective gas, and heat the equipment to 1000℃ at a heating rate of 3℃ / min. Then, introduce CH4 to deposit PyC for 60 min and repeat the deposition cycle 7 times.

[0060] The carbon deposition pyrolysis process is as follows: the argon flow rate is set to 3L / min during the heating and cooling process, the argon flow rate is 4L / min during the carbon deposition pyrolysis process, and the CH4 flow rate is 80L / min; then the temperature is cooled to room temperature to obtain a porous carbon matrix.

[0061] Step 4: Place the obtained porous carbon matrix in a high-temperature furnace for heat treatment to obtain a high thermal conductivity porous C / C composite material.

[0062] The heat treatment process for the composite material is as follows: the dried composite material is placed in a high-temperature furnace, argon is introduced as a protective gas, and the equipment is heated to 2000℃ for 2 hours at a heating rate of 5℃ / min, so that the phenolic resin-based amorphous carbon is transformed into a highly oriented crystal structure.

[0063] Example 4 A method for preparing a highly thermally conductive porous carbon framework material includes the following steps: Step 1: Dissolve 15.0g of resorcinol and 21.7g of 37.5wt% formaldehyde solution in 22.5mL of deionized water to obtain a mixture; then add 0.045g of CTAB to the mixture and magnetically stir the suspension for 20min to obtain a transparent precursor solution; add 2.0wt% expandable microspheres to the phenolic resin precursor solution and magnetically stir for 30min to obtain the initial solution.

[0064] Step 2: Immerse the low-density C / C in the initial solution obtained in Step 1, so that the block is completely submerged, and then place it in a vacuum drying oven. Evacuate the oven until the pressure inside is below 0.09 MPa and maintain for 30 minutes. Then, heat curing and microsphere expansion, normal pressure drying and carbonization are carried out.

[0065] The heating, curing, microsphere expansion, atmospheric pressure drying, and carbonization process is as follows: The low-density C / C composite material is placed in an oven at 65℃ and preheated for 25 minutes; it is then foamed by compression molding at 0.45 MPa and 85℃ for 20 minutes. After stopping the pressure application, heating and curing continue for 30 hours; subsequently, it is dried at 80℃ under atmospheric pressure for 20 hours; finally, it is placed in a tube furnace and heated to 1100℃ at a rate of 2℃ / min, held for 2 hours, with argon gas purging throughout as a protective gas to decompose the phenolic resin in the composite material into carbon.

[0066] Step 3: Place the carbonized sample in a CVD furnace, use argon as a protective gas, and heat the equipment to 900°C at a heating rate of 3°C / min. Then, introduce CH4 to deposit PyC for 100 min and repeat the deposition cycle 8 times.

[0067] The carbon deposition pyrolysis process is as follows: the argon flow rate is set to 2L / min during the heating and cooling process, the carbon deposition pyrolysis process is 2L / min, and the CH4 flow rate is 70L / min; then the temperature is cooled to room temperature to obtain a porous carbon matrix.

[0068] Step 4: Place the obtained porous carbon matrix in a high-temperature furnace for heat treatment to obtain a high thermal conductivity porous C / C composite material.

[0069] The heat treatment process for the composite material is as follows: the dried composite material is placed in a high-temperature furnace, argon is introduced as a protective gas, and the equipment is heated to 2200℃ for 2 hours at a heating rate of 5℃ / min, so that the phenolic resin-based amorphous carbon is transformed into a highly oriented crystal structure.

[0070] Example 5 A method for preparing a highly thermally conductive porous carbon framework material includes the following steps: Step 1: Dissolve 12.0 g of resorcinol and 15.0 g of 37.5 wt% formaldehyde solution in 19.0 mL of deionized water to obtain a mixture; then add 0.042 g of CTAB to the mixture and magnetically stir the suspension for 20 min to obtain a transparent precursor solution; add 2.5 wt% expandable microspheres to the phenolic resin precursor solution and magnetically stir for 35 min to obtain the initial solution.

[0071] Step 2: Immerse the low-density C / C in the initial solution obtained in Step 1, so that the block is completely submerged, and then place it in a vacuum drying oven. Evacuate the oven until the pressure inside is below 0.09 MPa and maintain for 30 minutes. Then, heat curing and microsphere expansion, normal pressure drying and carbonization are carried out.

[0072] The heating, curing, microsphere expansion, atmospheric pressure drying, and carbonization process is as follows: The low-density C / C composite material is placed in an oven at 65℃ and preheated for 30 minutes; it is then foamed by compression molding at 0.5 MPa and 90℃ for 20 minutes. After the pressure is stopped, heating and curing continue for 48 hours; subsequently, it is dried at 90℃ under atmospheric pressure for 24 hours; finally, it is placed in a tube furnace and heated to 900℃ at a rate of 4℃ / min, held for 2 hours, with argon gas purging throughout as a protective gas to decompose the phenolic resin in the composite material into carbon.

[0073] Step 3: Place the carbonized sample in a CVD furnace, use argon as a protective gas, and heat the equipment to 1100℃ at a heating rate of 3℃ / min. Then, introduce CH4 to deposit PyC for 250 min and repeat the deposition cycle 6 times.

[0074] The carbon deposition pyrolysis process is as follows: the argon flow rate is set to 1 L / min during the heating and cooling process, the carbon deposition pyrolysis process is 4 L / min, and the CH4 flow rate is 70 L / min; then the temperature is cooled to room temperature to obtain a porous carbon matrix.

[0075] Step 4: Place the obtained porous carbon matrix in a high-temperature furnace for heat treatment to obtain a high thermal conductivity porous C / C composite material.

[0076] The heat treatment process for the composite material is as follows: the dried composite material is placed in a high-temperature furnace, argon is introduced as a protective gas, and the equipment is heated to 2400℃ for 2 hours at a heating rate of 5℃ / min, so that the phenolic resin-based amorphous carbon is transformed into a highly oriented crystal structure.

[0077] Example 6 A method for preparing a highly thermally conductive porous carbon framework material includes the following steps: Step 1: Dissolve 12.0g of resorcinol and 16g of 37.5wt% formaldehyde solution in 20.0mL of deionized water to obtain a mixture; then add 0.06g of CTAB to the mixture and magnetically stir the suspension for 20min to obtain a transparent precursor solution; add 1.5wt% expandable microspheres to the phenolic resin precursor solution and magnetically stir for 40min to obtain the initial solution.

[0078] Step 2: Immerse the low-density C / C in the initial solution obtained in Step 1, so that the block is completely submerged, and then place it in a vacuum drying oven. Evacuate the oven until the pressure inside is below 0.09 MPa and maintain for 30 minutes. Then, heat curing and microsphere expansion, normal pressure drying and carbonization are carried out.

[0079] The heating, curing, microsphere expansion, atmospheric pressure drying, and carbonization process is as follows: The low-density C / C composite material is placed in an oven at 65℃ and preheated for 30 minutes; it is then foamed by compression molding at 0.5 MPa and 90℃ for 10 minutes. After stopping the pressure application, heating and curing continue for 24 hours; subsequently, it is dried at 90℃ under atmospheric pressure for 24 hours; finally, it is placed in a tube furnace and heated to 900℃ at a rate of 5℃ / min, held for 2 hours, with argon gas purging throughout as a protective gas to decompose the phenolic resin in the composite material into carbon.

[0080] Step 3: Place the carbonized sample in a CVD furnace, use argon as a protective gas, and heat the equipment to 1100℃ at a heating rate of 5℃ / min. Then, introduce CH4 to deposit PyC for 300 min and repeat the deposition cycle 6 times.

[0081] The carbon deposition pyrolysis process is as follows: the argon flow rate is set to 2L / min during the heating and cooling process, the argon flow rate is 4L / min during the carbon deposition pyrolysis process, and the CH4 flow rate is 70L / min; then the temperature is cooled to room temperature to obtain a porous carbon matrix.

[0082] Step 4: Place the obtained porous carbon matrix in a high-temperature furnace for heat treatment to obtain a high thermal conductivity porous C / C composite material.

[0083] The heat treatment process for the composite material is as follows: the dried composite material is placed in a high-temperature furnace, argon is introduced as a protective gas, and the equipment is heated to 2400℃ for 3 hours at a heating rate of 10℃ / min, so that the phenolic resin-based amorphous carbon is transformed into a highly oriented crystal structure.

[0084] Example 7 A method for preparing a highly thermally conductive porous carbon framework material includes the following steps: Step 1: Dissolve 13.5g of resorcinol and 21.7g of 37.5wt% formaldehyde solution in 20.0mL of deionized water to obtain a mixture; then add 0.048g of cetyltrimethylammonium bromide (CTAB) to the mixture, and magnetically stir the suspension for 25min to obtain a transparent precursor solution; add 1.8wt% expandable microspheres to the phenolic resin precursor solution, and magnetically stir for 30min to obtain the initial solution.

[0085] Step 2: Immerse the low-density C / C composite material in the initial solution obtained in Step 1, so that the block is completely submerged, and then place it in a vacuum drying oven. Evacuate the oven until the pressure inside is below 0.09 MPa and maintain it for 35 minutes. Then, it undergoes heating curing, microsphere expansion, normal pressure drying, and carbonization.

[0086] The heating, curing, microsphere expansion, atmospheric pressure drying, and carbonization process is as follows: The low-density C / C composite material is placed in an oven at 65℃ and preheated for 25 minutes; it is then foamed by compression molding at 0.4 MPa and 80℃ for 12 minutes. After stopping the pressure application, heating and curing continue for 36 hours; subsequently, it is dried at 100℃ under atmospheric pressure for 18 hours; finally, it is placed in a tube furnace and heated to 1000℃ at a rate of 3℃ / min, held for 4 hours, with argon gas purging throughout as a protective gas to decompose the phenolic resin in the composite material into carbon.

[0087] Step 3: Place the carbonized sample in a CVD furnace, use argon as a protective gas, and heat the equipment to 1000℃ at a heating rate of 4℃ / min. Then, introduce CH4 to deposit PyC for 150 min and repeat the deposition cycle 6 times.

[0088] The carbon deposition pyrolysis process is as follows: the argon flow rate is set to 2L / min during the heating and cooling process, the carbon deposition pyrolysis process is 3L / min, and the CH4 flow rate is 80L / min; then the temperature is cooled to room temperature to obtain a porous carbon matrix.

[0089] Step 4: Place the obtained porous carbon matrix in a high-temperature furnace for heat treatment to obtain a high thermal conductivity porous C / C composite material.

[0090] The heat treatment process for the composite material is as follows: the dried composite material is placed in a high-temperature furnace, argon is introduced as a protective gas, and the equipment is heated to 2000℃ for 2.5h at a heating rate of 8℃ / min, so that the phenolic resin-based amorphous carbon is transformed into a highly oriented crystal structure.

[0091] Example 8 A method for preparing a highly thermally conductive porous carbon framework material includes the following steps: Step 1: Dissolve 14.0 g of resorcinol and 17.4 g of 37.5 wt% formaldehyde solution in 21.0 mL of deionized water to obtain a mixture; then add 0.050 g of cetyltrimethylammonium bromide (CTAB) to the mixture, and magnetically stir the suspension for 30 min to obtain a transparent precursor solution; add 2.2 wt% expandable microspheres to the phenolic resin precursor solution, and magnetically stir for 35 min to obtain the initial solution.

[0092] Step 2: Immerse the low-density C / C composite material in the initial solution obtained in Step 1, so that the block is completely submerged, and then place it in a vacuum drying oven. Evacuate the oven until the pressure inside is below 0.09 MPa and maintain it for 40 minutes. Then, it undergoes heating curing, microsphere expansion, normal pressure drying, and carbonization.

[0093] The heating, curing, microsphere expansion, atmospheric pressure drying, and carbonization process is as follows: The low-density C / C composite material is placed in an oven at 70℃ and preheated for 30 minutes; then, it is foamed by compression molding at 0.35 MPa and 85℃ for 15 minutes. After stopping the pressure application, heating and curing continue for 40 hours; subsequently, it is dried at 95℃ under atmospheric pressure for 20 hours; finally, it is placed in a tube furnace and heated to 950℃ at a rate of 4℃ / min, held for 3 hours, with argon gas purging throughout as a protective gas to decompose the phenolic resin in the composite material into carbon.

[0094] Step 3: Place the carbonized sample in a CVD furnace, use argon as a protective gas, and heat the equipment to 1050℃ at a heating rate of 3℃ / min. Then, introduce CH4 to deposit PyC for 200 min and repeat the deposition cycle 7 times.

[0095] The carbon deposition pyrolysis process is as follows: the argon flow rate is set to 2.5 L / min during the heating and cooling process, the flow rate is 4 L / min during the carbon deposition pyrolysis process, and the CH4 flow rate is 85 L / min; then the temperature is cooled to room temperature to obtain a porous carbon matrix.

[0096] Step 4: Place the obtained porous carbon matrix in a high-temperature furnace for heat treatment to obtain a high thermal conductivity porous C / C composite material.

[0097] The heat treatment process for the composite material is as follows: the dried composite material is placed in a high-temperature furnace, argon is introduced as a protective gas, and the equipment is heated to 2200℃ for 2 hours at a heating rate of 7℃ / min, so that the phenolic resin-based amorphous carbon is transformed into a highly oriented crystal structure.

[0098] Comparative Example 1 The high thermal conductivity porous carbon skeleton material was prepared using the same method as in Example 6, except that in the preparation of the high thermal conductivity porous carbon skeleton material, step 2 was modified from "Place the low density C / C composite material in an oven, set the temperature to 65°C, and preheat for 30 min; foam by molding, with a pressure of 0.5 MPa, a temperature of 90°C, and a foaming time of 20 min" to "Place the low density C / C composite material in an oven, set the temperature to 65°C, and preheat for 30 min".

[0099] Figure 1 This is a flowchart illustrating the preparation process of a high thermal conductivity porous carbon skeleton material according to the present invention. As can be seen from the figure, a low-density carbon fiber preform material is first immersed in an initial solution containing expandable microspheres, followed by heating and curing, molding and foaming, drying and carbonization processes to obtain a thermally conductive carbon skeleton with a multi-level porous structure. Then, pyrolytic carbon is deposited through chemical vapor deposition, and the pyrolytic carbon is used to further control the pore size and connect the carbon fibers in the preform to obtain a porous carbon skeleton.

[0100] Figure 2 The image shows the morphology of the high thermal conductivity porous carbon framework material prepared in Example 1. As can be seen from the image, micropores and macropores are distributed on the surface, but the distribution is not very uniform. Two sizes of pores are distributed on the material surface: smaller micropores and larger macropores. However, the distribution of these pores is not uniform; some areas have denser pores, while others are relatively sparse, and there are even localized areas without pores, indicating that the uniformity of the foaming and carbonization processes in this example needs to be improved.

[0101] Figure 3 The image shows the morphology of the high thermal conductivity porous carbon framework material prepared in Example 6; and... Figure 2In contrast, this figure shows a more ideal pore structure: the material surface is covered with a large number of micropores and macropores, and the distribution of the pores is very uniform, with large and small pores interspersed. This uniform pore structure is beneficial to improving the thermal conductivity and mechanical properties of the material, indicating that the optimization of process parameters in Example 6 has achieved good results.

[0102] Figure 4 The figure shows the morphology of the high thermal conductivity porous carbon framework material prepared in Comparative Example 1. As can be seen from the figure, the microstructure of the high thermal conductivity porous carbon framework material provided in Comparative Example 1 of this invention is as follows: Figure 4 As shown, the results clearly reveal the decisive role of compression molding foaming in controlling the framework structure. Analysis indicates that, due to the lack of physical constraints provided by molding, expandable microspheres undergo free and disordered expansion during heating. This "free foaming" mode leads to two key structural defects: first, the microspheres over-expand and merge, causing partial pore wall rupture and a reduction in the total pore volume; second, the expansion of microspheres is asynchronous, ultimately forming pores of vastly different sizes and disordered distribution, rather than a uniform porous structure. This comparative example verifies from the opposite perspective that compression molding foaming is not a simple step, but a crucial "structure editing" process. By applying controllable mechanical constraints, it guides the microspheres to expand in a coordinated and uniform manner and pack tightly, which is a necessary prerequisite for obtaining an ideal three-dimensional network structure with uniform pore size, intact pore walls, and a continuous framework. These experimental results clearly indicate that to achieve the design goal of high thermal conductivity and multifunctional synergy in materials, the core process of "compression molding-foaming" must be precisely controlled. At the same time, it also demonstrates that the successful implementation of foaming technology is an inevitable result of the coupling of multiple factors.

[0103] Figure 5 The image shows the XPS spectrum of the high thermal conductivity porous carbon framework material prepared in Example 6 after high-temperature heat treatment. As can be seen from the image, the high-temperature heat treatment significantly purified the bulk phase of the carbon framework, resulting in a significantly lower oxygen content.

[0104] In summary, this invention discloses a high thermal conductivity porous carbon skeleton material, its preparation method, and its application. First, a low-density carbon fiber preform is immersed in an initial solution containing expandable microspheres, followed by sequential heating and curing, thermoplastic foaming, and drying. A thermally conductive carbon skeleton with a hierarchical porous structure is prepared through a carbonization process. Then, pyrolytic carbon is deposited using chemical vapor deposition, and the pyrolytic carbon is used to further control the pore size and connect the carbon fibers in the preform, thus creating a porous carbon skeleton. This porous carbon skeleton is then subjected to high-temperature graphitization treatment to obtain a high thermal conductivity porous carbon skeleton with a highly crystalline orientation structure, composed of carbon fibers, phenolic resin carbon, and pyrolytic carbon. By precisely controlling the foaming parameters (content, temperature, pressure, and time) of the expandable microspheres, the active construction of the macro-meso-micro hierarchical porous structure of the material is achieved, synergistically optimizing specific surface area, mass transfer efficiency, and thermal conductivity. The prepared carbon skeleton not only possesses excellent thermal stability and high thermal conductivity but also exhibits good structural designability and composite adaptability, making it suitable for high-end fields such as thermal management of high-power electronic devices and aerospace thermal protection systems.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a highly thermally conductive porous carbon framework material, characterized in that, Includes the following steps: The C / C composite material was immersed in a phenolic resin precursor solution containing expandable microspheres and subjected to vacuum impregnation to obtain the impregnated composite material. The impregnated composite material was subjected to molding foaming treatment, heat curing treatment, normal pressure drying treatment, carbonization treatment, chemical vapor deposition treatment, and high temperature heat treatment in sequence to obtain a high thermal conductivity porous carbon skeleton material. The expandable microspheres are acrylic polymer microspheres containing enclosed liquid alkane gas.

2. The method for preparing a high thermal conductivity porous carbon framework material according to claim 1, characterized in that, The conditions for the vacuum impregnation treatment include: pressure below 0.09 MPa and holding time of 30 to 40 minutes.

3. The method for preparing the high thermal conductivity porous carbon framework material according to claim 1, characterized in that, The conditions for the molding foaming process include: pressure of 0.2~0.5 MPa, foaming temperature of 70~90℃, and foaming time of 5~20 min; The conditions for the heat curing treatment include: a temperature of 70~90℃ and a time of 24~48 h; The conditions for the atmospheric pressure drying process include: a temperature of 80~100℃ and a time of 10~24 h.

4. The method for preparing a high thermal conductivity porous carbon framework material according to claim 1, characterized in that, The carbonization treatment conditions include: heating to 800-1100℃ at a heating rate of 2-5℃ / min under an argon atmosphere, and holding at that temperature for 2-4 hours.

5. The method for preparing a high thermal conductivity porous carbon framework material according to claim 1, characterized in that, The conditions for the chemical vapor deposition process include: using argon as a protective gas, heating to 900-1100°C at a heating rate of 1-5°C / min, followed by CH4 deposition of pyrolytic carbon for 30-300 min, and cooling to room temperature; the argon flow rate is 1-3 L / min during the heating and cooling processes; the argon flow rate is 2-5 L / min during CH4 deposition; and the number of cycles for pyrolytic carbon deposition is 5-8.

6. The method for preparing a high thermal conductivity porous carbon framework material according to claim 1, characterized in that, The conditions for the high-temperature heat treatment include: heating to 1600-2500℃ in an argon atmosphere at a heating rate of 5-10℃ / min for 2-3 hours.

7. The method for preparing a high thermal conductivity porous carbon framework material according to claim 1, characterized in that, The phenolic resin precursor solution containing expandable microspheres has a mass fraction of 0.5 wt% to 2.5 wt%; the expandable microspheres are mixed in the phenolic resin precursor solution by magnetic stirring for 20 to 40 min to obtain the phenolic resin precursor solution containing expandable microspheres.

8. The method for preparing a high thermal conductivity porous carbon framework material according to claim 7, characterized in that, The method for preparing the phenolic resin precursor solution is as follows: dissolve resorcinol and formaldehyde solution in deionized water, add hexadecyltrimethylammonium bromide, and stir magnetically for 10-40 min to obtain the phenolic resin precursor solution. The ratio of resorcinol, formaldehyde solution, deionized water and hexadecyltrimethylammonium bromide is (12.0~15.0) g : (17.4~21.7) g : (18.0~22.5) mL : (0.036~0.06) g.

9. A highly thermally conductive porous carbon framework material, characterized in that, It is prepared by the method of any one of claims 1-8 for preparing a high thermal conductivity porous carbon framework material.

10. The application of the high thermal conductivity porous carbon framework material of claim 9 in thermal management of high-power electronic devices or aerospace thermal protection systems.

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