Refined asphalt-based porous carbon double-layer orderly coated conductive material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of conductive material preparation, and relates to a refined asphalt-based porous carbon double-layer orderly coated conductive material and a preparation method and application thereof, and the preparation method comprises the following steps: S1, cutting medium and low temperature coal tar to obtain fraction section asphalt of 350-550 DEG C; s2, refining the fraction section asphalt, and blending with polyacrylonitrile fibers (PAN) to obtain a compound material; pre-oxidizing the compound material at low temperature, mixing with an activating agent, grinding, drying, activating at high temperature, cooling and washing to obtain refined asphalt porous carbon; s3, coating the refined asphalt porous carbon with silicone oil through an impregnation method, and curing to obtain a single-coating coating material; and S4, dissolving the single-coating coating material in tetrahydrofuran, then adding carbolic oil-gel to perform double-layer coating, and performing secondary curing treatment to obtain the conductive material. According to the invention, medium and low temperature coal tar is used as a raw material, and the cycle stability and electrochemical performance of the conductive material are improved and the processing cost is reduced through methods of fraction cutting, mixed carbonization and double-layer coating.

Description

Technical Field

[0001] The present invention belongs to the technical field of conductive material preparation, and relates to a conductive material with a refined asphalt-based porous carbon double layer orderly coating, and a preparation method and application thereof. Background Art

[0002] Conductive materials refer to materials specifically used to transport and conduct electric current, and are generally divided into two categories: good conductor materials and high resistance materials. Conductive materials can be divided into common materials, composite materials, and structural materials. Commonly used metal conductive materials can be divided into: metallic elements, alloys (copper alloys, aluminum alloys, etc.), composite metals, and other special-purpose conductive materials whose primary function is not conductivity; composite polymer conductive materials, which are made by combining general polymer materials with various conductive substances through filling, surface, or layered composites; structural polymer conductive materials, which refer to polymer materials that have conductive functions in their polymer structure itself or after doping.

[0003] At present, the preparation methods of conductive materials are: At present, the preparation methods of conductive materials mainly include the following: traditional metal conductive material preparation methods, composite polymer conductive material preparation methods and structural polymer conductive material preparation methods. However, these methods have some obvious disadvantages. For example, the preparation process of traditional metal conductive materials has high energy consumption, and it is difficult to meet the requirements of lightweight and flexibility in certain application scenarios. Although the conductivity of composite polymer conductive materials can be improved by filling and compounding, the preparation process is complicated and the cost is high, and the interface compatibility problem of the composite material may lead to unstable performance. Although structural polymer conductive materials have certain conductivity, their electrochemical properties still need to be improved, and the preparation process may require complex chemical synthesis steps. In contrast, the preparation method of the refined asphalt-based porous carbon double-layer ordered coated conductive material of the present invention has significant advantages.

[0004] Based on the above, it can be seen that existing conductive materials have technical problems such as poor stability, poor electrochemical performance and high processing costs. Summary of the Invention

[0005] In response to the technical problems of poor stability, poor electrochemical performance and high processing cost of existing conductive materials, the present invention provides a refined asphalt-based porous carbon double-layer orderly coated conductive material and its preparation method and application.

[0006] The present invention uses medium- and low-temperature coal tar as raw material and improves the cycle stability and electrochemical performance of the conductive material and reduces processing costs through fraction cutting, mixed carbonization and double-layer coating methods.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A method for preparing a conductive material having a refined pitch-based porous carbon double layer orderly coated thereon comprises the following steps:

[0009] S1, fraction cutting

[0010] Take medium and low temperature coal tar and use atmospheric and vacuum distillation to cut out phenol oil in the 180℃-220℃ fraction and asphalt in the 350℃-550℃ fraction respectively;

[0011] S2. Preparation of refined pitch porous carbon

[0012] Solvent refining the 350°C-550°C fraction asphalt in step S1 to obtain refined asphalt;

[0013] The polyacrylonitrile fiber is pre-cut into short fibers, and then added with refined asphalt to toluene to mix to obtain a composite material; the mass ratio of the refined asphalt to the polyacrylonitrile fiber is 1:(1-3); the mass of the toluene is 3-5 times the mass of the composite material;

[0014] The composite material is first subjected to low-temperature pre-oxidation treatment, and then mixed with an activator, ground, dried, activated at high temperature, and cooled and washed to obtain refined asphalt porous carbon of varying lengths and in order; the amount of activator added is 200% to 300% of the mass of the composite material; the activator is sodium hydroxide, zinc chloride, phosphoric acid, potassium nitrate or calcium hydroxide.

[0015] S3, silicone oil coating

[0016] Taking the refined pitch porous carbon obtained in step S2, coating the refined pitch porous carbon with silicone oil by an impregnation method, and curing after coating to obtain a single coating material;

[0017] S4, double layer coating

[0018] The single coating material obtained in step S3 is dissolved in tetrahydrofuran, and then phenol oil-gel is added, stirred, ultrasonicated, filtered, dried and carbonized, and then solidified to obtain a refined asphalt-based porous carbon double-layer orderly coated conductive material; the addition amount of the phenol oil-gel is 5wt% to 15wt%.

[0019] It is further defined that in step S2, the specific steps of refining the 350°C-550°C fraction asphalt are as follows:

[0020] S2.1. Evenly mix the 350°C-550°C fraction asphalt and a mixed solvent in a mass ratio of 1:2; the mixed solvent is a mixture of n-heptane and toluene in a mass ratio of 1:3;

[0021] S2.2. After preheating, stirring, and settling the uniformly mixed materials, refined asphalt is obtained from the upper solution.

[0022] It is further defined that in step S2, the polymerization molecular weight of the polyacrylonitrile fiber is 80,000.

[0023] It is further defined that in step S2, the temperature of the low-temperature pre-oxidation treatment is 200°C to 220°C, and the time is 1 hour to 1.5 hours; the temperature of the activation is 700°C to 900°C, and the time of the activation is 1 hour to 2 hours.

[0024] It is further defined that in step S2, the length-varying and ordered refined pitch porous carbon has a specific surface area exceeding 2000 m2·g -1 , the proportion of mesopores reaches up to 66%.

[0025] It is further defined that the specific process of silicone oil coating in step S3 is:

[0026] Silicone oil and toluene were first mixed in a mass ratio of (0.4-0.75):1 and stirred to obtain a silicone oil solution for 5-20 minutes. Under ultrasonic conditions, the refined asphalt porous carbon was coated with the silicone oil solution.

[0027] It is further defined that in step S4, the phenol oil-gel is obtained by mixing a gelling agent and the phenol oil of step S1 in a mass ratio of 1:(50-80); the temperature when the gelling agent and the phenol oil are mixed is 80°C to 200°C; and the gelling agent is one of polyaniline, polypyrrole or polythiophene.

[0028] It is further defined that the carbonization process in step S4 is: heating to 800° C. to 1000° C. at a rate of 0.5° C. / min to 3° C. / min, and maintaining the constant temperature for 0.5 h to 2 h.

[0029] The method for preparing the refined asphalt-based porous carbon double-layer orderly coated conductive material prepares the refined asphalt-based porous carbon double-layer orderly coated conductive material, the conductive material has a specific capacitance of 366mAh / g to 407mAh / g, and a capacity retention rate of 83% to 98% after 3000 cycles.

[0030] The application of the conductive material orderly coated with a refined pitch-based porous carbon double layer in supercapacitor electrodes.

[0031] Compared with the prior art, the present invention has the following positive effects:

[0032] 1. This invention uses low- to medium-temperature coal tar as a raw material and produces a conductive material coated with a double layer of refined pitch-based porous carbon through fraction cutting, mixed carbonization, and double-layer coating. The core-shell structure of this conductive material not only enhances its conductivity but also improves its mechanical stability and electrochemical performance through the double-layer coating.

[0033] 2. The present invention mixes the refined asphalt obtained by cutting the fraction with polyacrylonitrile fiber for carbonization to prepare a conductive material. The polyacrylonitrile fiber is both a carbon source and a template and does not need to be removed, which simplifies the process flow, optimizes the structural properties of the porous carbon, and improves the yield and performance of the porous carbon.

[0034] 3. The preparation method of the present invention achieved a yield of 75% for a single-layer refined pitch-based porous carbon, with a mesopore ratio as high as 66.3%. This demonstrates that the method effectively preserves the porous structure while increasing the mesopore ratio, which facilitates electrolyte storage and ion transport, thereby improving the conductive material's electrical properties.

[0035] 4. The present invention adopts a double-layer coating of silicone oil and phenol oil-gel. The use of phenol oil-gel as the coating layer provides additional conductivity and chemical stability for the material. At the same time, the addition of phenol oil gel also helps to improve the material and capacity retention rate. DETAILED DESCRIPTION

[0036] The technical solutions protected by the present invention are now described in detail with reference to the embodiments, but they should not be used as a limitation to the scope of protection of the present invention.

[0037] The present invention provides a method for preparing a conductive material having a refined asphalt-based porous carbon double layer orderly coated thereon, comprising the following steps:

[0038] S1, fraction cutting

[0039] Take medium and low temperature coal tar and use atmospheric and vacuum distillation to cut out phenol oil in the 180℃-220℃ fraction and asphalt in the 350℃-550℃ fraction respectively;

[0040] S2. Preparation of refined pitch porous carbon

[0041] Solvent refining the 350°C-550°C fraction asphalt in step S1 to obtain refined asphalt;

[0042] Polyacrylonitrile fiber (PAN) with a polymerization molecular weight of 80,000 is pre-cut into short fibers, which are then added into toluene and mixed with refined asphalt to obtain a compound material.

[0043] Preferably, the mass ratio of refined asphalt to polyacrylonitrile fiber is 1:(1-3); the mass of toluene is 3-5 times the mass of the compounded ingredients.

[0044] Exemplarily, the mass ratio of refined asphalt to polyacrylonitrile fiber is 1:1, 1:1.5, 1:2, 1:2.5 or 1:3.

[0045] The composite materials are first pre-oxidized, then mixed with an activator, ground, dried, activated at high temperature, cooled and washed to obtain refined asphalt porous carbon of varying lengths and in order; the amount of activator added is 200% to 300% of the mass of the composite materials; illustratively, the pre-oxidation temperature is 200°C, 210°C, and 220°C; the pre-oxidation time is 1h, 1.2h, and 1.5h; the amount of activator added is 200%, 250%, 270%, and 300% of the mass of the composite materials.

[0046] The activator is sodium hydroxide, zinc chloride, phosphoric acid, potassium nitrate or calcium hydroxide.

[0047] In step S2 of the present invention, the specific steps of refining the 350°C-550°C fraction asphalt are as follows:

[0048] S2.1. Evenly mix the 350°C-550°C fraction asphalt and a mixed solvent in a mass ratio of 1:2; the mixed solvent is a mixture of n-heptane and toluene in a mass ratio of 1:3;

[0049] S2.2. Preheat, stir, and allow the mixed material to settle, and then obtain refined asphalt from the upper layer of solution. Preferably, the preheating temperature is 80°C, stirring is performed at a speed of 200 r / min for 1 hour, and the settling time is 3 hours.

[0050] Preferably, in step S2, the activation temperature of the composite material is 700° C. to 900° C., and the heating time is 1 hour to 2 hours.

[0051] Preferably, the length-varying and ordered refined pitch porous carbon has a specific surface area exceeding 2000 m2·g -1 , the proportion of mesopores is the highest at 66%.

[0052] S3, silicone oil coating

[0053] The refined asphalt porous carbon obtained in step S2 is taken, and silicone oil is coated on the refined asphalt porous carbon obtained in step S2 by an impregnation method. After the coating is completed, the carbon is cured at 100° C. for 1 hour to obtain a single-coating coating material.

[0054] In step S3 of the present invention, silicone oil and toluene are first mixed uniformly in a mass ratio of (0.4 to 0.75):1 to obtain a silicone oil solution; the silicone oil and toluene are stirred for 5 to 20 minutes to mix uniformly.

[0055] Under ultrasonic conditions, the refined pitch porous carbon is coated with a silicone oil solution; illustratively, the ultrasonic power is 200 W, the ultrasonic temperature is 80° C., and the ultrasonic time is 10 to 30 minutes.

[0056] S4, double layer coating

[0057] The single coating material obtained in step S3 was dissolved in tetrahydrofuran, and then phenol oil-gel was added and stirred, ultrasonicated, filtered, dried and carbonized. After carbonization, it was cured at 70°C for 2.5h to obtain a refined asphalt-based porous carbon double-layer orderly coated conductive material.

[0058] Preferably, the amount of phenol oil-gel added is 5 wt% to 15 wt%, and exemplary, the amount of phenol oil-gel added is 5 wt%, 8 wt%, 10 wt% or 15 wt%.

[0059] In step S4 of the present invention, the phenol oil-gel is prepared by mixing a gelling agent with the phenol oil from step S1 in a mass ratio of 1:50 to 80. The gelling agent and the phenol oil are mixed at a temperature of 80° C. to 200° C. Exemplarily, the gelling agent and the phenol oil are mixed at a temperature of 80° C., 100° C., 150° C., or 200° C.

[0060] Preferably, the gelling agent is polyaniline, polypyrrole or polythiophene.

[0061] Preferably, the carbonization process in step S4 is: heating to 800° C. to 1000° C. at a rate of 0.5° C. / min to 3° C. / min, and maintaining the constant temperature for 0.5 h to 2 h.

[0062] The conductive material with ordered coating of refined asphalt-based porous carbon double layer prepared by the above preparation method of the present invention has a specific capacitance of 366 mAh / g to 407 mAh / g and a capacity retention rate of 83% to 98% after 3000 cycles.

[0063] It has good electrical conductivity and can be used in electrodes of supercapacitors.

[0064] The preparation method of the present invention is described below with several groups of examples, and the performance of the refined asphalt-based porous carbon double-layer ordered coated conductive material is verified through experiments.

[0065] It should be noted that, unless otherwise specified, the reagents and drugs used in the following examples and experiments are conventional commercially available products.

[0066] It should be noted that, unless otherwise specified, the operations used in the following examples and experiments are routine operations in the art.

[0067] Example 1

[0068] This embodiment provides a refined pitch-based porous carbon double-layer orderly coated conductive material, comprising the following steps:

[0069] S1, fraction cutting

[0070] 1 kg of medium-low temperature coal tar was subjected to vacuum distillation to obtain 51.8 g of phenol oil in the 180°C to 220°C fraction and 504.5 g of asphalt in the 350-550°C fraction.

[0071] S2. Preparation of refined pitch porous carbon

[0072] 100g of 350-550℃ fraction asphalt and 200g of extractant (toluene / n-heptane mass ratio is 3:1) are placed in an extraction device, then the extraction device is heated to 80℃, the stirrer speed is controlled at 200r / min, stirred for 1h, and allowed to stand at a constant temperature for 3h to separate the supernatant liquid. Finally, the extractant is distilled and recovered to obtain 73g of refined asphalt (abbreviated as RCTP).

[0073] 20g of RCTP was placed in a crucible in a tube furnace. The temperature was raised at 5°C / min to 220°C and maintained constant. When the temperature reached 200°C, dry air was introduced at 80mL / min and oxidation was continued for 1 hour. 20g of polyacrylonitrile fiber (molecular weight 80,000) was cut into 5mm short fibers and mixed with 20g of refined asphalt in 120g of toluene to form a composite material. The mixture was then oven-dried at 50°C for 5 hours.

[0074] 5g of the resulting composite was mixed with 10g of potassium hydroxide and ground, and the mixture was then heated at 700°C for 1 hour under an argon flow. The activated sample was then thoroughly washed with dilute hydrochloric acid and distilled water to obtain a refined, well-ordered, pitch-like porous carbon.

[0075] In this embodiment, the yield of the ordered refined pitch porous carbon with varying lengths was calculated to be 75%.

[0076] S3, silicone oil coating

[0077] Take 10 mL of silicone oil and 25 mL of toluene and stir for 5 minutes to mix evenly to obtain a silicone oil solution.

[0078] Take 5g of refined asphalt porous carbon of varying lengths and order, put it into a beaker, and then add silicone oil solution to ensure that the silicone oil solution completely covers the refined asphalt porous carbon of varying lengths and order; then ultrasonicate for 10 minutes, the ultrasonic temperature is 80℃, and the ultrasonic power is 200W to obtain the reaction product; after the coating is completed, cure at 100℃ for 1h to obtain a single-coating coating material.

[0079] S4, double layer coating

[0080] The single coating coating material is dissolved in tetrahydrofuran, and then phenol oil-gel is added and stirred, ultrasonicated, filtered, dried and carbonized to obtain a refined asphalt-based porous carbon double-layer orderly coated conductive material; the addition amount of phenol oil-gel is 5wt%.

[0081] In this embodiment, carbonization is carried out in a tubular furnace, the temperature is raised to 800°C at a rate of 0.5°C / min, and the temperature is maintained at a constant level for 0.5h under a nitrogen atmosphere to complete carbonization; and the material is cured at 70°C for 2.5h to obtain the final conductive material.

[0082] In this example, polyaniline (PANI) was selected as the gelling agent. The gelling agent and the phenol oil prepared in step S1 were mixed at a mass ratio of 1:60 to produce a phenol oil-gel. Specifically, the gelling agent and phenol oil mixture was heated to 80°C and thoroughly mixed. The mixture was then cooled to room temperature, whereupon the gelling agent began to solidify, and the phenol oil gradually solidified to form a gel, i.e., the phenol oil-gel.

[0083] Example 2 to Example 6

[0084] The preparation methods provided in Examples 2 to 6 are the same as those in Example 1, except that the amounts of raw materials used and the process parameters are different, as shown in Table 1.

[0085] Table 1 Process parameters of Examples 2 to 6

[0086]

[0087]

[0088] It should be noted that in Table 1, RCTP refers to refined asphalt and PAN refers to polyacrylonitrile fiber.

[0089] The properties of the conductive material prepared above and coated with a double layer of ordered refined pitch-based porous carbon were further studied. In order to highlight the novelty of the technical solution of the present invention, the following comparative examples were also prepared.

[0090] Comparative Example 1

[0091] The difference between this comparative example and Example 1 is that in step S2, the 350°C-550°C fraction asphalt is directly mixed with the polyacrylonitrile fiber without using toluene and n-heptane for refining. The remaining steps are the same as in Example 1.

[0092] Comparative Example 2

[0093] The difference between this comparative example and Example 2 is that no gelling agent is added in step S4, and phenol oil is directly used for double-layer coating. The remaining steps are the same as those in Example 2.

[0094] Comparative Example 3

[0095] The difference between this comparative example and Example 3 is that no activator is added in step S2. The remaining steps are the same as those in Example 3.

[0096] Comparative Example 4

[0097] The difference between this comparative example and Example 4 is that no polyacrylonitrile fiber is added in step S2. The remaining steps are the same as those in Example 4.

[0098] Comparative Example 5

[0099] Comparative Example 5 differs from Example 5 in that silicone oil coating is not performed, and the double-layer coating of step S4 is performed directly after step S2.

[0100] Comparative Example 6

[0101] The difference between Comparative Example 6 and Example 6 is that the double-layer coating of step S4 is not adopted, and only steps S1 to S3 are adopted, and steps S1 to S3 are the same as those of Example 6.

[0102] Test 1

[0103] The 12 groups of ordered refined asphalt porous carbons of different lengths prepared in the above-mentioned embodiments and comparative examples were respectively tested for carbon yield, specific surface area (SSA), micropore volume ratio, and mesopore volume ratio of the porous carbons with reference to the national standards for coking products in the metallurgical industry GB / T19587-2017, GB / T21650.1-2008, and GB / T21650.2-2008. The results are shown in Table 2.

[0104] Table 2 Performance test results of porous carbon of Examples and Comparative Examples

[0105]

[0106] From the data in Table 2, it can be seen that the specific surface area of ​​the ordered refined asphalt porous carbon of varying lengths prepared by the present invention is higher than that of each comparative example; and the mesopore volume is also significantly better than that of each comparative example, with the highest reaching 66.3%. This shows that the present invention uses medium- and low-temperature coal tar as raw material, and obtains the ordered refined asphalt porous carbon of varying lengths by fraction cutting and mixed carbonization. In addition, during the preparation process, the cut fractions are refined, compounded with polyacrylonitrile fiber, and activated with an activator, all of which can promote the improvement of the performance of the ordered refined asphalt porous carbon of varying lengths, resulting in a higher specific surface area and mesopore ratio. These advantages make the conductive material obtained after the subsequent double-layer coating have excellent conductive properties.

[0107] Test 2

[0108] The refined asphalt-based porous carbon double-layer orderly coated conductive materials prepared in the examples and comparative examples were mixed with polytetrafluoroethylene (PTFE) at a mass ratio of 85:15, rolled and punched to obtain electrodes, and assembled into symmetrical supercapacitors. The obtained refined asphalt-based porous carbon double-layer orderly coated conductive materials were placed in a 6 mol / L KOH electrolyte. At 1 A·g -1The specific capacitance of the electrode material was evaluated by testing at a current density of 10A·g -1 The electrode material was cycled 3000 times and the capacitance retention was recorded to evaluate the electrochemical stability of the electrode material. The electrochemical test performance results are shown in Table 3.

[0109] Table 3 Test results of supercapacitors of examples and comparative examples

[0110] serial number Specific capacitance (mAh / g) 3000-week cycle retention rate (%) Example 1 372 83.1 Example 2 366 84.2 Example 3 375 85.3 Example 4 407 97.5 Example 5 401 94.3 Example 6 391 91.5 Comparative Example 1 331 56.4 Comparative Example 2 335 62.7 Comparative Example 3 321 67.4 Comparative Example 4 311 67.9 Comparative Example 5 333 64.5 Comparative Example 6 309 57.8

[0111] The data in Table 3 show that the refined pitch-based porous carbon double-layer ordered-coated conductive material prepared by the present invention has a specific capacitance of 366 mAh / g to 407 mAh / g, and a capacity retention rate of 83% to 98% after 3000 cycles. Compared with Comparative Examples 1 to 6, the refined pitch-based porous carbon double-layer ordered-coated conductive material prepared by the present invention exhibits excellent stability and electrochemical properties, effectively enhancing the electrochemical performance of supercapacitors.

[0112] The material prepared by the above method is obtained by selecting polyacrylonitrile fiber and using potassium hydroxide as the activator. However, when the type of activator is changed according to the material range defined by the present invention, the prepared porous carbon and double-layer ordered coated conductive material also show similar effects as shown in Tables 2 and 3. The double-layer coating of phenol oil-gel further enhances the conductivity and structural stability of the material and improves the comprehensive performance of the material. The prepared double-layer ordered coated conductive material has a high specific capacitance and cycle retention rate, thereby improving the electrochemical performance of the supercapacitor. In addition, the process preparation cost is low, the yield is high, and there is no pollution to the environment, thereby developing a new approach to prepare refined asphalt-based porous carbon double-layer ordered coated conductive materials.

[0113] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for preparing a conductive material coated with a refined pitch-based porous carbon double layer in an orderly manner, characterized in that: The following steps are involved: S1, fraction cutting Take medium and low temperature coal tar and use atmospheric and vacuum distillation to cut out phenol oil in the 180℃-220℃ fraction and asphalt in the 350℃-550℃ fraction respectively; S2. Preparation of refined pitch porous carbon Solvent refining the 350°C-550°C fraction asphalt in step S1 to obtain refined asphalt; The polyacrylonitrile fiber is pre-cut into short fibers, and then added with refined asphalt to toluene to mix to obtain a composite material; the mass ratio of the refined asphalt to the polyacrylonitrile fiber is 1:(1-3); the mass of the toluene is 3-5 times the mass of the composite material; The composite material is first subjected to a low-temperature pre-oxidation treatment, and then mixed with an activator, ground, dried, activated at high temperature, cooled and washed to obtain a refined pitch porous carbon of varying lengths and in an orderly manner; the amount of the activator added is 200% to 300% of the mass of the composite material; the activator is sodium hydroxide, zinc chloride, phosphoric acid, potassium nitrate or calcium hydroxide; S3, silicone oil coating Taking the refined pitch porous carbon obtained in step S2, coating the refined pitch porous carbon with silicone oil by an impregnation method, and curing after coating to obtain a single coating material; S4, double layer coating The single coating material obtained in step S3 is dissolved in tetrahydrofuran, and then phenol oil-gel is added, stirred, ultrasonicated, filtered, dried and carbonized, and then solidified to obtain a refined asphalt-based porous carbon double-layer orderly coated conductive material; the addition amount of the phenol oil-gel is 5wt% to 15wt%.

2. The method for preparing a conductive material having a double layer of ordered coating of refined pitch-based porous carbon according to claim 1, characterized in that: In step S2, the specific steps of refining the 350°C-550°C fraction asphalt are as follows: S2.

1. Evenly mix the 350°C-550°C fraction asphalt and a mixed solvent in a mass ratio of 1:2; the mixed solvent is a mixture of n-heptane and toluene in a mass ratio of 1:3; S2.

2. After preheating, stirring, and settling the uniformly mixed materials, refined asphalt is obtained from the upper solution.

3. The method for preparing a conductive material having a double layer of ordered coating of refined pitch-based porous carbon according to claim 1, characterized in that: In step S2, the polymerization molecular weight of the polyacrylonitrile fiber is 80,000.

4. The method for preparing a conductive material having a double layer of ordered coating of refined pitch-based porous carbon according to claim 1, characterized in that: In step S2, the temperature of the low-temperature pre-oxidation treatment is 200° C. to 220° C., and the time is 1 hour to 1.5 hours; the temperature of the activation is 700° C. to 900° C., and the time of the activation is 1 hour to 2 hours.

5. The method for preparing a conductive material having a double layer of ordered coating of refined pitch-based porous carbon according to claim 1, characterized in that: The refined asphalt porous carbon of varying lengths and order in step S2 has a specific surface area exceeding 2000 m2·g -1 , the proportion of mesopores reaches up to 66%.

6. The method for preparing a conductive material having an ordered double layer of refined pitch-based porous carbon coating according to claim 1, characterized in that: The specific process of silicone oil coating in step S3 is: First, silicone oil and toluene are mixed in a mass ratio of (0.4-0.75):1, and stirred evenly to obtain a silicone oil solution. The stirring time is 5-20 minutes. Under ultrasonic conditions, the refined asphalt porous carbon is coated with the silicone oil solution.

7. The method for preparing a conductive material having a double layer of ordered coating of refined pitch-based porous carbon according to claim 1, characterized in that: In step S4, the phenol oil-gel is obtained by mixing a gelling agent and the phenol oil of step S1 in a mass ratio of 1:(50-80); the temperature when the gelling agent and the phenol oil are mixed is 80°C to 200°C; the gelling agent is one of polyaniline, polypyrrole or polythiophene.

8. The method for preparing a conductive material having a double layer of ordered coating of refined pitch-based porous carbon according to claim 1, characterized in that: The carbonization process in step S4 is as follows: heating to 800° C. to 1000° C. at a rate of 0.5° C. / min to 3° C. / min, and maintaining the constant temperature for 0.5 h to 2 h.

9. The method for preparing a refined pitch-based porous carbon double-layer orderly coated conductive material according to claim 8, wherein: The specific capacitance of the conductive material is 366 mAh / g to 407 mAh / g, and the capacity retention rate is 83% to 98% after 3000 cycles.

10. Use of the conductive material orderly coated with a double layer of refined pitch-based porous carbon as claimed in claim 8 in a supercapacitor electrode.

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