Highly conductive flexible carbon plate and process for producing the same

Abstract

The application relates to the technical field of liquid flow batteries and fuel cell bipolar plates, and discloses a high-conductivity flexible carbon plate and a production process thereof. In the boiling intercalation stage, a closed pore agent is introduced, composite carbon is cooled to 180-200 DEG C in a boiling furnace, and due to the temperature difference effect, micro-negative pressure is generated in the gap of the graphite intermediate. Then, the polymer closed pore agent is injected into the boiling furnace in multiple stages and multiple directions under high pressure. Under the double action of high-pressure injection and high-speed collision of the powder boiling, the closed pore agent layer and the pore intercalation are realized in combination with the micro-negative pressure effect of the graphite intermediate pores. The closed pore agent can not only quickly fill the surface pores of the composite carbon, but also can deeply enter the deep pores, so that the uniform distribution of the closed pore agent in the carbon matrix is realized, the closed porosity of the carbon plate is improved, and the problems of closed pore agent falling off or extrusion deformation in the subsequent treatment process are avoided.

Description

Technical Field

[0001] This invention relates to the field of bipolar plate technology for flow batteries and fuel cells, and in particular to a highly conductive flexible carbon plate and its manufacturing process. Background Technology

[0002] The preparation process of highly conductive flexible carbon plates mostly uses high-purity graphite as the matrix, combined with carbon nanotubes, graphene and other nano-carbon materials to build a conductive network, and then achieves performance control through molding, densification and other processes. However, the existing process still has significant technical pain points in the construction of closed-cell structure and the synergistic optimization of conductivity and flexibility, which makes it difficult to meet the stringent requirements of high-end applications for the comprehensive performance of carbon plates. In the current preparation of highly conductive flexible carbon plates, to improve the airtightness, impermeability, and structural stability of the carbon plates, it is usually necessary to introduce a closed-cell agent to construct a closed pore structure. Traditional methods of adding closed-cell agents mainly fall into two categories: one is to directly dry-mix the closed-cell agent with raw materials such as graphite and nano-carbon materials in the initial mixing stage, and then proceed together to subsequent processes such as high-temperature intensive mixing and molding; the other is to attach the closed-cell agent to the surface of the carbon plate or penetrate into the surface pores through methods such as soaking or spraying during the pre-pressing stage of the cake board. However, both of these methods have insurmountable drawbacks: For processes involving the addition of a closing agent in the initial mixing stage, the significant density difference between the closing agent and high-purity graphite can easily lead to "segregation" during dry mixing and pneumatic conveying. This results in uneven distribution of the closing agent in the composite carbon, ultimately causing local deviations in the closed-cell rate of the carbon plate to exceed 30%. Furthermore, during subsequent high-temperature mixing, unprotected closing agents are prone to premature high-temperature decomposition or carbonization, losing their closing-cell function. This necessitates increasing the amount of closing agent added, which not only increases production costs but may also affect the flexibility of the carbon plate due to residual carbonization products. For the process of adding a closed-cell agent after pre-pressing, the porosity of the cake board has decreased to 40%-50% and the pore connectivity is poor after pre-pressing. Therefore, the closed-cell agent cannot effectively penetrate into the internal pores of the carbon board through soaking or spraying. It can only form a closed-cell structure on the surface, while the interior of the carbon board remains predominantly open-cell, resulting in insufficient overall impermeability and structural stability. Furthermore, this method requires additional drying and curing processes, extending the production cycle. The interfacial bonding between the closed-cell agent and the carbon board substrate is also weak, making it prone to detachment during subsequent precision pressing and bending, leading to a decline in the performance of the carbon board. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a highly conductive flexible carbon plate and its manufacturing process. The closing agent can not only quickly fill the surface pores of the composite carbon, but also penetrate deep into the pores, achieving uniform distribution of the closing agent in the carbon matrix, improving the closed-cell rate of the carbon plate, thereby avoiding the problem of closing agent falling off or being deformed by extrusion during subsequent processing.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solution: A manufacturing process for a highly conductive flexible carbon board includes the following steps: High-purity graphite is mixed with high-purity carbon nanotubes and / or graphene powder, and then fed into a high-temperature kneading furnace for high-temperature kneading at 900-1000℃. The high-purity graphite expands into a porous, high-specific-surface-area worm-like graphite intermediate, which adsorbs with the high-purity carbon nanotubes or graphene powder to obtain composite carbon. The composite carbon is fed into a fluidized bed furnace and cooled to 180-200℃ inside the furnace, which creates a slight negative pressure in the pores of the graphite intermediate. This allows the nano-sized closed-pore agent to be injected into the fluidized bed furnace under high pressure from multiple stages and directions. The closed-pore agent particles achieve interlayer and pore embedding by relying on the high-speed collision of the powder boiling and the slight negative pressure effect of the graphite intermediate pores. With the help of the residual temperature of 180-200℃, micro-melting adhesion is achieved to form a mixture. Then, the temperature is cooled to 60-80℃ to achieve adhesion and curing of the nano-sized closed-pore agent. The mixture and gas are separated. The mixture falls into the central control belt feeding device. The mixture is layered and fed according to the thickness and uniformity of the material layer. The material layer is driven by the belt into the pre-pressing roller to be pressed into a slab. The density of the gluten board is increased by pressing it step by step with multi-stage precision rollers, and then it is cut and slit.

[0005] As a further implementation method, a circular cutting machine is used to dynamically and precisely control the length and width dimensions of the blank product to achieve cutting and slitting.

[0006] As a further implementation method, each blank product is sorted and classified according to grade, and then subjected to overpressure shaping according to the sorted grade to make the density of the blank product greater than 1.80g / cm³. 3 .

[0007] As a further implementation method, after overpressure shaping, the blank product is sent into a high-temperature molding chamber for molding hot melt internal impregnation and shaping. The temperature of the molding chamber is controlled at 160-200℃. The temperature of the molding chamber is adjusted according to the hot melting point of the closing agent. Under hot melt and high pressure, the closing agent further penetrates into the graphite pores and interlayer to achieve the closing effect. Increase the temperature of the molding chamber to 280-350℃ at a rate of 20-30℃ / min and hold for 5-10 minutes, then cool down to below 50℃ to achieve micro-carbonization of excess polymer closed-cell agent overflowing from the surface of the board.

[0008] As a further implementation method, after the product cools to room temperature, it is engraved into the required size and shape using an engraving machine, and then inspected and packaged.

[0009] As a further implementation, the high-purity graphite has a carbon content greater than 99.5%, the high-purity carbon nanotubes and / or graphene powder have a mass fraction of 5-10%, and the mixing time is 30-40 seconds.

[0010] As a further implementation method, the fluidized bed furnace adopts a dual cooling system of water-cooled jacket and inert gas purging, which reduces the temperature of composite carbon from 900-1000℃ to 180-200℃ within 10-15s.

[0011] As a further implementation method, a modified polyolefin-based closed-cell agent is used. A plunger-type high-pressure pump is used to inject the closed-cell agent into the fluidized bed furnace in 3-5 stages. The delivery volume of each stage is evenly distributed according to 2%-5% of the total mass. The nozzles at the output end of the plunger pump are evenly distributed on the furnace body. During the process, the temperature inside the fluidized bed furnace is monitored in real time to maintain a stable residual temperature of 180-200℃, and the micro-melting time is controlled at 20-30s.

[0012] As a further implementation method, multiple sets of vibrating cloth feeders are used to achieve layered cloth feeding, and the thickness of each layer is monitored in real time during the feeding process; the material layer is pre-pressed by pre-pressing rollers in conjunction with pressure sensors, with the initial pressure set at 2-3MPa, increasing by 0.5MPa every 1min, and the final pressure controlled at 5-8MPa. The thickness of the pre-pressed cake board is controlled at 2%-5% of the total thickness of the material layer.

[0013] Secondly, a highly conductive flexible carbon plate is manufactured using any of the production processes described above.

[0014] The beneficial effects of the present invention are as follows: 1. This invention introduces a nano-scale pore-closing agent during the fluidized bed intercalation stage. The composite carbon is cooled to 180-200℃ in a fluidized bed furnace. Due to the temperature difference effect, a slight negative pressure is generated in the pores of the graphite intermediate. Then, the polymer pore-closing agent is injected into the fluidized bed furnace under high pressure in multiple stages and directions. Under the dual action of high-pressure injection and high-speed collision of powder fluidization, combined with the slight negative pressure effect of the graphite intermediate pores, the pore-closing agent is embedded in the interlayer and pores. The pore-closing agent can not only quickly fill the surface pores of the composite carbon, but also penetrate into the deep pores, achieving uniform distribution of the pore-closing agent in the carbon matrix, improving the pore-closing rate of the carbon plate, thereby avoiding the problem of pore-closing agent falling off or being deformed by extrusion during subsequent processing. 2. The closed-cell agent of the present invention does not need to be mixed with graphite and nano-carbon materials in advance, avoiding decomposition loss during high-temperature mixing and significantly reducing raw material costs. On the other hand, the closed-cell agent can directly form a mixture with composite carbon under the action of micro-melting adhesion, without the need for additional drying and curing process, shortening the single production cycle to 8-10 hours and improving production efficiency. 3. The uniformly embedded and firmly bonded closed-cell agent will not form conductive blind areas or structural defects inside the carbon plate. Furthermore, the closed-cell agent is further melted and filled into microcracks during the hot pressing process, which reduces the bending radius of the carbon plate. This achieves a synergistic optimization of high conductivity and flexibility, making the carbon plate more suitable for high-end application scenarios such as fuel cell bipolar plates and flexible electronic device electrodes.

[0015] 4. A plunger-type high-pressure pump is used to deliver the pore-closing agent in 3-5 stages. The delivery nozzles are evenly distributed on the furnace body, which can ensure that the pore-closing agent particles are uniformly dispersed in the fluidized bed furnace. The composite carbon and the pore-closing agent collide fully, which improves the embedding efficiency of the pore-closing agent. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Figure 1 This is a flowchart of the production process of highly conductive flexible carbon plates in an embodiment of the present invention. Detailed Implementation

[0018] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0019] Example 1 In a typical embodiment of the present invention, reference is made to Figure 1 As shown, a manufacturing process for a highly conductive flexible carbon board includes the following steps: S1: High-temperature mixing: High-purity graphite is mixed with high-purity carbon nanotubes and / or graphene powder (high-purity carbon nanotubes and / or graphene powder can be used alone or in combination; in this embodiment, they are used in combination); then, it is fed into a high-temperature mixing furnace by pneumatic conveying for high-temperature mixing. At a high temperature of 900-1000℃ (preferably 950℃) inside the high-temperature mixing furnace, the high-purity graphite instantly expands into a porous, high-specific-surface-area worm-like graphite intermediate. In this state, the worm-like graphite intermediate, carbon nanotubes, and graphene powder adsorb onto each other, resulting in composite carbon.

[0020] The high-purity graphite contains more than 99.5% carbon, and the mass fraction of high-purity carbon nanotubes or graphene powder is 5-10% (preferably 10%), with the remainder being high-purity graphite.

[0021] Understandably, the raw materials need to be pretreated before high-temperature intensive mixing. The selected high-purity graphite needs to be subjected to airflow milling to control the particle size distribution between 10-50μm and ensure particle uniformity. The high-purity carbon nanotubes need to undergo nitro-modification (using a 5% nitric acid solution refluxed at 90℃ for 4-6 hours), and the graphene powder needs to be ultrasonically exfoliated (power 300-500W, ultrasonic time 2-3 hours) to solve the agglomeration problem of the two and improve their compatibility with graphite.

[0022] When mixing raw materials, a twin-screw mixer is used for premixing, with the speed controlled at 300-500 r / min (preferably 400 r / min) and the mixing time at 15-20 min (preferably 18 min) to ensure that the carbon nanotube / graphene powder is evenly dispersed in high-purity graphite. When using pneumatic conveying, an inert gas (such as nitrogen) is used as the conveying medium, with the flow rate controlled at 8-12 m / s (preferably 10 m / s) to avoid oxidation of the raw materials during the conveying process.

[0023] The high-temperature internal mixing furnace uses natural gas for heating, with a heating rate controlled at 15-20℃ / min (preferably 20℃ / min) to avoid excessively rapid heating that could cause localized overheating of the graphite particles. The furnace pressure is maintained at a slight positive pressure to prevent outside air from entering and affecting the quality of the intermediate. The mixing time is controlled at 30-40s (preferably 35s) to ensure that the graphite is fully expanded and firmly adsorbed with carbon nanotubes / graphene. The bulk density of the composite carbon is controlled at 0.6-0.8 g / cm³. 3 .

[0024] Each batch of composite carbon requires sampling and testing. The pore structure of the worm-like graphite intermediate is observed using a scanning electron microscope (SEM) to ensure that it meets the requirements of subsequent processes.

[0025] S2: Fluidized Layering: The composite carbon obtained after high-temperature intensive mixing is rapidly cooled to 180-200℃ (preferably 190℃) in a fluidized bed furnace via a special system. During this process, a slight negative pressure is generated within the pores of the graphite intermediate due to the temperature difference effect. A special conveying device injects nano-sized closed-pore agents into the fluidized bed furnace at multiple stages and directions under high pressure (mass percentage of 10-20% (preferably 15%)). This allows the closed-pore agent nanoparticles to achieve interlayer and pore embedding through high-speed collisions caused by powder jetting and fluidization, and the slight negative pressure effect within the graphite intermediate pores. The residual temperature of 180-200℃ further facilitates micro-melting adhesion to form a mixture. The mixture is then cooled to 60-80℃ to achieve adhesion and curing of the nano-sized closed-pore agent.

[0026] Understandably, the fluidized bed furnace employs a dual cooling system of water-cooled jacket and inert gas purging. The inlet water temperature of the water-cooled jacket is controlled at 20-30℃ (preferably 25℃), the outlet water temperature is ≤60℃, and the inert gas (nitrogen) purging rate is 6m / s. 3The temperature is controlled at a rate of / h to ensure that the composite carbon temperature drops from 950℃ to 190℃ within 10-15s, with a stable cooling rate (fluctuation ≤5℃ / min). Simultaneously, a pressure sensor monitors the furnace pressure in real time to ensure a stable micro-negative pressure between -0.01 and -0.03MPa, providing favorable conditions for the embedding of the closing agent.

[0027] For the selection and pretreatment of nanoscale closed-cell agents: modified polyolefin closed-cell agents (preferably polyethylene-vinyl acetate copolymer) are selected; the closed-cell agents need to be dried (dried at 100℃ for 2 hours, with a moisture content ≤0.5%) to prevent particle agglomeration; an air classifier is used to screen the particle size to ensure that the qualified particle size is ≥95%.

[0028] The special conveying device uses a plunger-type high-pressure pump with pressure controlled at 8-12MPa (preferably 10MPa), conveying the closing agent in 3-5 stages (preferably 5 stages), with each stage's conveying volume evenly distributed according to 2-5% of the total mass. The conveying nozzles adopt a multi-directional layout (8 conveying nozzles evenly distributed around the furnace body and 4 layers distributed axially) to ensure that the closing agent particles are evenly dispersed in the fluidized bed furnace. The powder fluidization stirring rate is controlled at 25Hz by adjusting the fan frequency, so that the collision frequency between the composite carbon and the closing agent is 5-10 times / s, improving the embedding efficiency (embedding rate ≥90%).

[0029] During the process, the temperature inside the boiling furnace is monitored in real time to maintain a stable residual temperature of 190℃ (fluctuation ≤3℃). The micro-melting time is controlled at 20-30s to ensure that the surface of the pore-closing agent is slightly melted, which not only achieves a firm adhesion with the graphite intermediate, but also avoids excessive melting that would cause pore blockage. After the mixture is formed, samples are taken for testing, and the embedding state of the pore-closing agent is analyzed by X-ray diffraction (XRD) to ensure uniform embedding between layers and within pores.

[0030] S3: Material-Gas Cyclone Separation: The mixture and gas are separated by a cyclone separator, and the mixture falls into the central control belt conveyor.

[0031] Understandably, a high-efficiency cyclone separator is selected for separation. The inlet velocity of the high-efficiency cyclone separator is controlled at 20m / s to ensure a gas-solid separation efficiency of ≥99.5%. The inner wall of the separator is coated with a wear-resistant ceramic coating to reduce wear on the inner wall caused by the mixture and extend the service life of the equipment. A pulse dust collector is installed at the top of the separator to collect the escaped fine particles of the mixture, avoid dust pollution and reduce raw material loss. Central control belt feeding device connection: The bottom discharge valve of the cyclone separator adopts a star-shaped discharger (speed 10-15r / min) to evenly discharge the mixture onto the central control belt; a material level sensor is installed on the belt to monitor the material layer thickness in real time. If the material layer thickness deviation exceeds ±10mm, the speed of the star-shaped discharger is automatically adjusted to ensure that the mixture is evenly conveyed to the subsequent process and the material layer thickness fluctuation is ≤5%.

[0032] S4: Layered fabric: Precise fabric application is achieved by controlling the thickness and uniformity of the fabric layers. Understandably, multiple sets of vibrating fabric placing machines (vibration frequency 30-50Hz, amplitude 2-3mm) are used in conjunction with a laser positioning system (positioning accuracy ±0.1mm) to achieve multi-layer fabric placement; an adjustable baffle (adjustment accuracy ±0.5mm) is set below the fabric placing machine to control the thickness of a single layer (the thickness of a single layer is controlled at 1-3mm, and the number of layers is determined according to the final carbon plate thickness requirement, generally 5-10 layers). Material layer thickness and uniformity control: The thickness of each material layer is monitored in real time by a laser thickness gauge (measurement accuracy ±0.01mm). If the thickness deviation exceeds ±0.05mm, the vibration amplitude of the vibrating cloth spreader and the height of the baffle are automatically adjusted.

[0033] The fabric application area is designed to be sealed, maintaining a slight positive pressure (0.01-0.02MPa) to prevent external dust from entering; the ambient temperature is controlled at 20-25℃, and the relative humidity is controlled at 40%-60% to avoid the mixture absorbing moisture (moisture content ≤0.3%), which would affect the subsequent molding quality; during the fabric application process, the density of the material layer is sampled and tested every 30 minutes (controlled at 0.7-0.9g / cm³) to ensure that the quality of the material layer is consistent across batches.

[0034] S5: Pre-compression molding: The material layer is driven into the pre-compression roller by a belt and pressed into a sponge board; The pre-compression roller adopts a double-roller structure, and the pre-compression pressure can be monitored in real time by a pressure sensor. The belt drive speed is controlled at 0.5-1m / min to ensure that the material layer is fully compressed; the pre-compression pressure is gradually increased, with the initial pressure set at 2-3MPa, increasing by 0.5MPa every 1min, and the final pressure controlled at 5-8MPa, with a holding time of 10-15s to avoid cracking of the material layer due to sudden pressure rise; the thickness of the pre-compressed sponge board is controlled at 2%-5% of the total thickness of the material layer (e.g., if the total thickness of the material layer is 500mm, the thickness of the sponge board is 10-25mm). After obtaining the sponge cake boards, quality inspection is conducted. Each board is inspected for appearance (no cracks, missing corners, delamination, or other defects), thickness, and density. A nuclear density analyzer is used to test the bulk density of the sponge cake boards, ensuring it reaches 0.6-0.8 g / cm³. 3 If any defective products are found, the pre-compression parameters should be adjusted immediately.

[0035] S6: Precision pressing and density improvement, thickness control: The density is further improved by pressing through multiple stages of precision rollers. The last stage is a hydraulic precision control roller to achieve precise thickness control (thickness deviation ±0.02mm).

[0036] For multi-stage precision pressing rollers, 4-5 stages of precision pressing rollers are set, with the diameter of each stage increasing sequentially. The first stage is a mechanically pressurized roller, and the last stage is a hydraulically controlled precision roller. The hydraulic system adopts servo control to ensure stable pressure. The first stage precision pressing pressure is set at 8MPa, increasing the bulk density to 1.0g / cm³; the second stage pressure is 10MPa, increasing the bulk density to 1.2g / cm³; the third stage pressure is 12MPa, increasing the bulk density to 1.3g / cm³; and the last stage hydraulically controlled precision pressure is 15MPa, increasing the bulk density to 1.5g / cm³. The hydraulic precision control roller is equipped with a laser thickness gauge and a closed-loop control system. If the thickness deviation is detected to exceed ±0.01mm, the hydraulic pressure is automatically adjusted to ensure that the final carbon plate thickness deviation is strictly controlled within ±0.02mm. At the same time, a torque sensor is used to monitor the roller shaft torque to prevent overload damage to the equipment.

[0037] S7: Cutting and Slitting: According to requirements, the circular cutter is used to dynamically and precisely control the length and width dimensions of the blank products to achieve cutting and slitting. After each batch is cut and slitting, blank products are randomly selected and their length and width dimensions are inspected. Unqualified products need to be recut or scrapped.

[0038] S8: Grade Sorting and Overpressure Shaping: Each blank product is sorted and classified according to grade, and then overpressure shaped according to the sorted grade. At this time, the density of the blank product is controlled at 1.8g / cm³. 3 The thickness deviation is ±0.02mm.

[0039] Specifically, grading standards are established based on the density, thickness, appearance (number of defects such as cracks, missing corners, and scratches) and internal quality of the raw products, classifying them into superior, first-class, and qualified products. An automated sorting line (sorting speed 1-3 pieces / min) is adopted, equipped with a density detector (detection accuracy ±0.01g / cm³), a laser thickness gauge, and a vision inspection system to automatically identify product grades and classify and transport them (superior product rate target ≥80%, first-class product rate ≥15%, qualified product rate ≤5%). During the sorting process, manual sampling inspection (sampling ratio 5%) is carried out to ensure accurate grade determination. A four-column hydraulic press is used for overpressure shaping. The pressure is set according to the product grade: 15-18MPa for superior products, 18-20MPa for first-grade products, and 20-22MPa for qualified products. The overpressure time is controlled at 30-60s, and the holding time is 10-20s to ensure uniform density increase. The hydraulic press is equipped with a heating device to reduce the forming resistance of the carbon plate and prevent cracking. After overpressure shaping, each product is tested for density (ensuring ≥1.8g / cm³, deviation ±0.02g / cm³), thickness (deviation ±0.02mm), and flatness (flatness error ≤0.03mm / m); pressure sensors are used to detect the pressure distribution in each area of ​​the product (pressure distribution uniformity error ≤5%) to ensure there are no local density deficiencies; superior products require additional conductivity testing to ensure they meet the requirements of high-end applications.

[0040] S9: Hot pressing and surface modification: The material enters a high-temperature molding chamber for hot-melt impregnation and shaping. The temperature of the molding chamber is controlled at 160-200℃. The temperature of the molding chamber is adjusted according to the different hot melting points of the polymer closing agent. Under hot melting and high pressure (generally 10-15MPa), the closing agent will further penetrate into the graphite pores and interlayers to achieve the closing effect. Then, the temperature of the molding chamber is rapidly increased to 280-350℃ and then rapidly cooled to achieve micro-carbonization of the excess polymer closing agent overflowing from the surface of the board, thereby further improving the conductivity of the board surface.

[0041] The high-temperature molding chamber is made of stainless steel and equipped with an electric heating system and a hydraulic pressurization system. Temperature and pressure sensors are installed inside the chamber to monitor process parameters in real time. The carbon plate, after being overpressure shaped, is placed into a mold and then sent into the high-temperature molding chamber. First, the temperature is raised to 160-200℃ at a rate of 5-8℃ / min (adjusted according to the melting point of the closing agent; for example, for a closing agent with a melting point of 160℃, the temperature is set to 170-180℃), and held for 10-15 minutes to allow the closing agent to fully melt. Then, the pressure is slowly increased to 10-15MPa (pressurization rate 0.5MPa / min) and held for 20-30 minutes to ensure that the molten closing agent fully penetrates the graphite pores (pore filling rate ≥95%) and interlayers, achieving a closed-cell effect (closed-cell rate ≥90%). During the process, a vacuum system is used to remove air from the chamber to prevent bubble formation. After impregnation with the closed-cell agent, the temperature is rapidly increased to 280-350℃ at a rate of 20-30℃ / min (adjusted according to the carbonization temperature of the closed-cell agent, such as 300-320℃ for polyethylene closed-cell agents), held at this temperature for 5-10 minutes, and then rapidly cooled to below 50℃ using a water cooling system. This allows the excess closed-cell agent (thickness ≤0.1mm) overflowing from the board surface to undergo micro-carbonization (carbonization degree 50%-60%). After micro-carbonization, the board surface is lightly sanded with sandpaper to remove residual impurities and improve surface smoothness. After hot pressing, the closed-cell rate, surface conductivity, volume resistivity, and mechanical properties of the carbon board are tested.

[0042] S10: Engraving, shaping, inspection and packaging: After the product cools to room temperature, it is engraved into the size and shape required by the customer using an engraving machine. The engraving machine engraving is an existing technology.

[0043] Quality inspectors conduct tests as required before packaging and warehousing. Qualified carbon plates are individually packaged using anti-static packaging materials such as anti-static pearl cotton, with partitions separating each plate to prevent damage during transportation. Product information, such as model, specifications, grade, batch, and production date, is labeled on the outside of the packaging. Upon warehousing, the plates are arranged according to batch and grade.

[0044] Example 2 A highly conductive flexible carbon plate is manufactured using the production process described in Example 1.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A manufacturing process for highly conductive flexible carbon plates, characterized in that, Includes the following steps: High-purity graphite is mixed with high-purity carbon nanotubes and / or graphene powder, and then fed into a high-temperature kneading furnace for high-temperature kneading at 900-1000℃. The high-purity graphite expands into a porous, high-specific-surface-area worm-like graphite intermediate, which adsorbs with the high-purity carbon nanotubes or graphene powder to obtain composite carbon. The composite carbon is fed into a fluidized bed furnace and cooled to 180-200℃ inside the furnace, which creates a slight negative pressure in the pores of the graphite intermediate. This allows the nano-sized closed-pore agent to be injected into the fluidized bed furnace under high pressure from multiple stages and directions. The closed-pore agent particles achieve interlayer and pore embedding by relying on the high-speed collision of the powder boiling and the slight negative pressure effect of the graphite intermediate pores. With the help of the residual temperature of 180-200℃, micro-melting adhesion is achieved to form a mixture. Then, the temperature is cooled to 60-80℃ to achieve adhesion and curing of the nano-sized closed-pore agent. The mixture and gas are separated. The mixture falls into the central control belt feeding device. The mixture is layered and fed according to the thickness and uniformity of the material layer. The material layer is driven by the belt into the pre-pressing roller to be pressed into a slab. The density of the gluten board is increased by pressing it step by step with multi-stage precision rollers, and then it is cut and slit.

2. The manufacturing process for a highly conductive flexible carbon plate according to claim 1, characterized in that, The circular cutter is used to dynamically and precisely control the length and width dimensions of the blank product to achieve cutting and slitting.

3. The manufacturing process for a highly conductive flexible carbon plate according to claim 2, characterized in that, Each raw product is sorted and classified according to grade, and then subjected to overpressure shaping according to the sorted grade to ensure that the density of the raw product is greater than 1.8g / cm³. 3 .

4. The manufacturing process for a highly conductive flexible carbon plate according to claim 3, characterized in that, After high-pressure shaping, the blank product is sent into a high-temperature molding chamber for molding hot melt internal impregnation and shaping. The temperature of the molding chamber is controlled at 160-200℃. The temperature of the molding chamber is adjusted according to the hot melting point of the closing agent. Under hot melt and high pressure, the closing agent further penetrates into the graphite pores and interlayer to achieve the closing effect. Increase the temperature of the molding chamber to 280-350℃ at a rate of 20-30℃ / min and hold for 5-10 minutes, then cool down to below 50℃ to achieve micro-carbonization of excess polymer closed-cell agent overflowing from the surface of the board.

5. The manufacturing process for a highly conductive flexible carbon plate according to claim 4, characterized in that, After the product cools to room temperature, it is engraved into the required size and shape using an engraving machine, and then inspected and packaged.

6. The manufacturing process for a highly conductive flexible carbon plate according to claim 1, characterized in that, The high-purity graphite has a carbon content greater than 99.5%, the high-purity carbon nanotubes and / or graphene powder have a mass fraction of 5-10%, and the mixing time is 30-40 seconds.

7. The manufacturing process for a highly conductive flexible carbon plate according to claim 1, characterized in that, The fluidized bed furnace employs a dual cooling system of water-cooled jacket and inert gas purging, which allows the temperature of the composite carbon to drop from 900-1000℃ to 180-200℃ within 10-15 seconds.

8. The manufacturing process for a highly conductive flexible carbon plate according to claim 1, characterized in that, The closed-cell agent is a modified polyolefin closed-cell agent. A plunger-type high-pressure pump is used to pump the closed-cell agent into the fluidized bed furnace in 3-5 stages. The delivery volume of each stage is evenly distributed according to 2%-5% of the total mass. The nozzles at the output end of the plunger pump are evenly distributed on the furnace body. During the process, the temperature inside the fluidized bed furnace is monitored in real time to maintain a stable residual temperature of 180-200℃, and the micro-melting time is controlled at 20-30s.

9. The manufacturing process for a highly conductive flexible carbon plate according to claim 1, characterized in that, Multiple sets of vibrating cloth feeders are used to achieve layered cloth feeding, and the thickness of each layer is monitored in real time during the feeding process. The material layer is pre-compressed by pre-compressing rollers in conjunction with pressure sensors. The initial pressure is set to 2-3 MPa, and it is increased by 0.5 MPa every 1 minute. The final pressure is controlled at 5-8 MPa, and the pressure holding time is 10-15 seconds. The thickness of the pre-compressed cake board is controlled at 2%-5% of the total thickness of the material layer.

10. A highly conductive flexible carbon plate, characterized in that, The highly conductive flexible carbon plate is manufactured using the production process described in any one of claims 1-9.

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