High-conductivity and high-strength activated carbon and preparation method thereof

Abstract

The preparation method comprises the following steps: uniformly mixing a carbon precursor with rich functional groups and high thermal stability with an activator in a dispersion liquid, and carrying out ion activation, washing purification, drying, airflow crushing and particle size screening to obtain the activated carbon with four high properties. The activating agent is uniformly dispersed and anchored in the carbon precursor in an ion form (such as K < + > and Cs < + >) under the adsorption / coordination action of functional groups, and controllable construction of a through micropore structure in the activated carbon is realized through uniform etching and pore-forming of activating agent ions on a carbon skeleton in a high-temperature activation process; therefore, the activated carbon has high specific surface area (2000-3200m < 2 > g <-1 >), high conductivity (800-1300S m <-1 >), high tap / compacted density (0.4-0.7 g cm <-3 >) and high particle strength (500-100MPa), which exceed most of the currently known activated carbon materials. In addition, compared with a traditional activated carbon preparation method, the method has the advantages of being low in alkali-carbon ratio, high in activation efficiency, weak in corrosivity and suitable for large-scale preparation.

Description

Technical Field

[0001] The present invention relates to the technical field of new materials and preparation thereof, in particular to a high-conductivity and high-strength activated carbon and a preparation method thereof. Background Art

[0002] Supercapacitors, due to their high power density, long service life, robust charge-discharge capabilities, and safety, have been widely used in a variety of applications, including renewable energy grid-connected power supplies, high-power starting power supplies, and brake energy recovery. As a core component of supercapacitors, electrode materials directly influence their electrochemical performance. Activated carbon, with its low cost, high specific surface area, adjustable pore structure, and strong electrochemical stability, is currently the most widely used electrode material.

[0003] In recent years, silicon-based materials have become popular due to their high theoretical specific capacity (4200 mAh g -1 ) and low operating voltage (≈0.3V vs Li + / Li), has become one of the most promising negative electrode materials for high-energy-density lithium-ion batteries. However, the drastic volume expansion of silicon (more than 300%) during the charge and discharge process can lead to particle breakage and electrode pulverization, which in turn leads to poor capacity and cycle stability of silicon-based materials, seriously hindering its commercialization process. To solve this problem, researchers have focused their attention on chemical vapor deposition (CVD) silicon-carbon negative electrode technology. Group 14 of the United States was the first to use CVD technology to deposit silicon in the micropores of activated carbon, and successfully prepared a new silicon-carbon composite material with greatly improved cycle stability. When preparing silicon-carbon negative electrodes by CVD method, activated carbon is indispensable as a key carrier material. The rich pore structure of activated carbon can accommodate the uniform distribution of silicon particles, effectively alleviating the volume expansion problem of silicon during the charge and discharge process, thereby improving the cycle stability and safety of the battery.

[0004] Activated carbon is produced by physically or chemically activating carbon precursors (biomass / polymer / asphalt-derived carbon, green coke, etc.) at high temperatures. Due to the structural contradiction between the large specific surface area (high porosity) of activated carbon and its high electrical conductivity, high tap / compacted density, and high particle strength, it is difficult to achieve all the "four highs" at the same time. High specific surface area activated carbon is usually chemically activated, which requires a large amount of strong alkali to etch the carbon precursor from the outside to the inside to form pores, forming a large number of dendritic deep pores and dead spaces inside the activated carbon. This results in a long transmission distance and large transmission resistance of ions inside the activated carbon, and the continuous conductive network is destroyed, resulting in limited conductivity and active material utilization of the activated carbon, making it difficult to meet the development needs of high energy and high power energy storage devices. On the other hand, the loose porous structure of high specific surface area activated carbon makes its compacted density (<0.5g cm -3) and the mechanical strength of the particles are low. During the battery rolling process, some particles will break and the active material will fall off and lose electricity, resulting in poor volume energy storage performance of the electrode, which is difficult to meet the development needs of miniaturization and lightweight devices. In addition, as a key carrier material for CVD silicon-carbon negative electrodes, the poor particle strength of activated carbon also makes it difficult to withstand the severe volume changes and mechanical stress of silicon during the energy storage process, resulting in the material's cyclic stability being difficult to meet the needs of high-end applications. Therefore, it is of great significance to prepare "four highs" activated carbon with high specific surface area, high conductivity, high vibration / compaction density and high particle strength. It is a key and difficult problem that needs to be solved urgently in this field.

[0005] In order to solve the problem of balancing the porosity and conductivity of activated carbon, researchers have used highly conjugated carbon precursors, such as fossil-based precursors such as coal, asphalt and coke, to prepare highly conductive activated carbon. Such fossil-based precursors contain a large amount of polycyclic aromatic hydrocarbons, which are conducive to the formation of large-area conjugated structures during high-temperature treatment. For example, patent CN102491320B discloses a method of preparing a high specific surface area asphalt-based activated carbon material using asphalt and rosin as raw materials through hot melt stirring, high-temperature carbonization, pre-oxidation and activation treatment. Patent CN103803550A cokes the powder obtained by crushing the asphalt to obtain green coke, activates the crushed green coke powder with KOH, and then washes, crushes and dries to obtain an asphalt-based activated carbon. Patent CN110127694A prepares a high-strength, low-resistance (65-80μΩ·m) activated carbon by uniformly mixing coal tar and other carbonaceous materials, pressing, activating, crushing and drying.

[0006] Compounding activated carbon with other highly conductive nanocarbons (carbon nanotubes, graphene oxide, conductive carbon black, etc.) is also an effective method for preparing highly conductive activated carbon. For example, patent CN103050294B uses phenolic resin as a carbon source and employs supercritical drying or freeze-drying methods to in situ prepare activated carbon / carbon nanotube composite aerogel electrode materials. The prepared electrode materials have high conductivity and high specific capacitance (390F g -1 ). Patent CN107331523B prepares a flexible three-dimensional porous film composite material by vacuum filtration of a suspension of graphene oxide, carbon nanotubes and activated carbon. This method fully utilizes the advantages of large specific surface area and high conductivity of graphene oxide and carbon nanotubes, and then introduces activated carbon to inhibit the agglomeration of graphene oxide and carbon nanotubes. The prepared composite material exhibits excellent electrochemical properties when applied to supercapacitors and lithium-ion capacitors. Patent CN106115693B in-situ composites nitrogen-doped phenolic resin with graphene oxide to prepare a composite phenolic resin-based activated carbon. Graphene oxide helps to form a complete conductive network in the activated carbon, and the phenolic resin is anchored to the graphene oxide during the curing process. The prepared activated carbon with a large specific surface area has low internal resistance and excellent specific capacity.

[0007] In addition, researchers also repair defects by high-temperature secondary heat treatment of activated carbon, thereby improving the crystallinity and electrical conductivity of activated carbon. For example, patent CN101290837A uses methane, ethylene or acetylene gas as a carbon source and microporous zeolite molecular sieve as a template to prepare activated carbon with a large specific surface area by gas phase deposition in a quartz tube reactor. After 1000-1600°C high-temperature secondary treatment, activated carbon with low oxygen content and hydrophilicity is obtained.

[0008] Although the above methods can improve the electrical conductivity of activated carbon, there are still some problems. Specifically, the chemical inertness of high conjugated precursors is strong, which requires a large amount of corrosive activator and / or a long reaction time, resulting in increased production cost. High-conductivity nanocarbon is difficult to uniformly disperse during preparation, and the preparation cost is high, which restricts its practical application. In addition, too high a secondary heat treatment temperature usually leads to a decrease in the specific surface area of activated carbon and pore collapse.

[0009] The incompatibility of large specific surface area and high density of activated carbon has been a difficult point that has restricted the development of the field. There are currently few patents for the preparation of high-density activated carbon. From the existing paper materials, researchers have improved the density of activated carbon by methods such as direct mechanical compaction of activated carbon, graphene-induced densification assembly, and ultra-microporous structure design. For example, Zhu et al. (Nano Energy, 2013, 2, 764) prepared a high-density and high-volumetric specific capacity porous carbon material by simple mechanical compaction treatment of porous graphene. Yang et al. (Adv. Sci., 2019, 6, 1802355) proposed embedding activated carbon in a dense graphene network to prepare a carbon material with excellent volumetric specific capacity. However, there are still few reports on new structures and preparation methods of activated carbon.

[0010] The purpose of the present application is to provide a high-conductivity and high-strength activated carbon and a preparation method thereof. Compared with the published patents and literatures, the present application uniformly mixes a carbon precursor with rich functional groups and high thermal stability with an activating agent in a dispersion liquid; during high-temperature activation, the anchored activating agent ions uniformly etch the carbon skeleton to create pores, achieving controllable construction of microporous structures, thereby preparing a "four-high" activated carbon with high specific surface area (2000-3200 m 2 g -1 ), high electrical conductivity (800-1300 S m -1 ), high tap / compacted density (0.4-0.7 g cm -3 ) and high particle strength (50-100 MPa). SUMMARY

[0011] The present invention provides a high-conductivity and high-strength activated carbon and a preparation method thereof. A carbon precursor having rich functional groups and high thermal stability is uniformly mixed with an activator in a dispersion liquid. The adsorption / coordination effect of the functional groups converts the activator into an ionic form (such as K + 、Cs + ) is evenly dispersed and anchored in the carbon precursor, and a through-hole microporous structure is constructed inside the activated carbon through uniform etching during the activation process, achieving the compatibility of the "four high" properties of activated carbon. The preparation steps are as follows:

[0012] (1) The carbon precursor is dissolved / dispersed in a compatible polar solvent to form a polymer solution or nanosol, which is labeled as solution A; the activator is dissolved in water, which is labeled as solution B;

[0013] (2) After solution A and solution B are thoroughly stirred and mixed, they are placed in an oven and completely dried to obtain an activated precursor;

[0014] (3) The activated precursor is subjected to high-temperature activation treatment under an inert atmosphere, and then washed, purified, dried, air-flow crushed and particle size screened to obtain activated carbon with "four high" properties. The pore and surface state can be further controlled through secondary heat treatment modification.

[0015] Furthermore, the carbon precursor in step (1) is an activated carbon precursor with rich functional groups and high thermal stability, including but not limited to lignin, chitosan, phenolic resin, carbon quantum dots, oxidized asphalt, etc.; the polar solvent is deionized water, anhydrous ethanol, acetic acid solution, N, N-dimethylformamide (DMF), tetrahydrofuran (THF), etc., and the specific selection depends on the carbon precursor used; the dissolution / dispersion ratio of the carbon precursor to the polar solvent is 1:5 to 1:300 g mL -1 .

[0016] Furthermore, the activator in step (1) is one or a mixture of KOH and CsOH; the dispersion ratio of the activator to water is 1:20 to 1:80 g mL -1 .

[0017] Furthermore, in step (2), the mass ratio of the carbon precursor to the activator is 1:0.1 to 1:4.

[0018] Furthermore, the heating rate of the activation treatment in step (3) is 0.1-30°C min -1 , the activation temperature is 500-950℃, and the holding time is 0.5-4h.

[0019] Further, the washing method in step (3) adopts acid washing and water washing, the acid washing solution is a mixed solution of hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid and formic acid; the main body is hydrochloric acid, the concentration range is 0.5-3 mol / L -1 ; according to the types of carbon precursor and activator, the nitric acid solubility is 0-0.5 mol / L -1 , the sulfuric acid solubility is 0-1.0 mol / L -1 , the hydrofluoric acid concentration can be 0-0.5 mol / L -1 , and the formic acid solubility is 0-0.5 mol / L -1 ; the sample to be washed is immersed in the acid washing solution and stirred at 25-95℃ for 3-24h, and according to the impurity content and pore structure of the activated carbon, the acid washing times can be 1-4 times. After acid washing, water (deionized water, distilled water, pure water, etc.) is repeatedly washed, and the pH of the washing solution after water washing needs to reach 6.5 or more.

[0020] Further, the high-temperature secondary heat treatment temperature of the activated carbon in step (3) is 400-1600℃, and the holding time is 0.5-5h. This step can be selected to be implemented or not implemented according to the requirements of the final product.

[0021] The beneficial technical effects of the present application are:

[0022] (1) The present application prepares a new type of activated carbon with high specific surface area, high electrical conductivity, high tap / compacted density and high particle strength, which comprehensively surpasses the level of traditional activated carbon in performance.

[0023] (2) Compared with the traditional activation method, the uniform ion activation method adopted by the present application has the advantages of low alkali / carbon ratio, high activation efficiency, low corrosion and suitability for large-scale preparation. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 SEM image and N2 isothermal adsorption-desorption curve of the activated carbon prepared in Example 1.

[0025] Figure 2 SEM image and N2 isothermal adsorption-desorption curve of the activated carbon prepared in Example 4. Figure 3 Preparation schematic diagram of the "four-high" activated carbon. DETAILED DESCRIPTION

[0026] The present application will be further illustrated by the following examples, but the present application is not limited to only the following examples.

[0027] Example 1

[0028] The preparation method of a highly conductive and high-strength activated carbon in Example 1 is as follows: 1.0 g of oxidized asphalt is fully dispersed in 40 mL of anhydrous ethanol, and 1.0 g of KOH is completely dissolved in 20 mL of deionized water. The two solutions are fully stirred and mixed for 8 hours, and then placed in a 110°C oven to completely dry to obtain an activated precursor. Then, the activated precursor is placed in a high-temperature tube furnace and heated at 5°C min under a high-purity argon atmosphere. -1 The sample was heated to 800℃ at a heating rate of 1 hour for activation. After the tube furnace cooled to room temperature, the activated sample was taken out and treated with 1 mol L -1 The activated carbon was then immersed in hydrochloric acid, stirred at 60°C for 10 hours, and washed repeatedly with deionized water until the pH reached >6.5. Finally, it was dried, jet milled, and sieved to obtain highly conductive and strong activated carbon. To further control its pore structure and surface properties, the activated carbon was subjected to a secondary heat treatment at 900°C for 1 hour in a high-purity argon atmosphere.

[0029] Example 2

[0030] The preparation method of a highly conductive and high-strength activated carbon in Example 2 is as follows: 2.0 g of oxidized asphalt is fully dispersed in 40 mL of anhydrous ethanol, and 1.0 g of CsOH·H2O is completely dissolved in 20 mL of deionized water. The two solutions are stirred and mixed for 6 hours, and then placed in a 110°C oven to completely dry to obtain an activated precursor. Next, the activated precursor is placed in a high-temperature tube furnace and heated at 3°C ​​min-1 under a high-purity argon atmosphere. -1 The sample was heated to 900℃ at a heating rate of 1 hour for activation. After the tube furnace cooled to room temperature, the activated sample was taken out and treated with 2 mol L -1 Hydrochloric acid and 0.1 mol L -1 The activated carbon was immersed in hydrofluoric acid, stirred at 80°C for 12 hours, and then washed repeatedly with distilled water until the pH was >6.5. Finally, it was dried, jet milled, and sieved to obtain highly conductive and strong activated carbon. To further control its pore structure and surface properties, the activated carbon was subjected to a secondary heat treatment at 1000°C for 2 hours in a high-purity argon atmosphere.

[0031] Example 3

[0032] The preparation method of a highly conductive and high-strength activated carbon in Example 3 is as follows: 1.0 g of carbon quantum dots are dispersed in 40 mL of anhydrous ethanol, and 1.0 g of KOH is completely dissolved in 20 mL of deionized water. The two solutions are stirred and mixed for 8 h, and then placed in a 110°C oven to completely dry to obtain an activated precursor. Then, the activated precursor is placed in a high-temperature tube furnace and heated at 5°C min under a high-purity argon atmosphere. -1 The sample was heated to 800℃ at a heating rate of 100℃ and activated for 2h. After the tube furnace cooled to room temperature, the activated sample was taken out and treated with 1mol L -1Hydrochloric acid and 0.1 mol L -1 The activated carbon was then immersed in sulfuric acid, stirred at 70°C for 10 hours, and washed repeatedly with deionized water until the pH reached >6.5. Finally, it was dried, jet milled, and sieved to obtain highly conductive and strong activated carbon. To further control its pore structure and surface properties, the activated carbon was subjected to a secondary heat treatment at 1100°C for 1 hour in a high-purity argon atmosphere.

[0033] Example 4

[0034] The preparation method of a highly conductive and high-strength activated carbon in Example 4 is as follows: 1.0 g of carbon quantum dots are dispersed in 40 mL of anhydrous ethanol, and 3.0 g of CsOH·H2O is completely dissolved in 60 mL of deionized water. The two solutions are thoroughly stirred and mixed for 6 h, and then placed in a 110°C oven to completely dry to obtain an activated precursor. Subsequently, the activated precursor is placed in a high-temperature tube furnace and heated at 3°C ​​min-1 under a high-purity argon atmosphere. -1 The sample was heated to 800℃ at a heating rate of 100℃ and activated for 3h. After the tube furnace cooled to room temperature, the activated sample was taken out and treated with 2mol L -1 Hydrochloric acid and 0.1 mol L -1 The activated carbon was immersed in hydrofluoric acid, stirred at 85°C for 12 hours, and then washed repeatedly with distilled water until the pH was >6.5. Finally, it was dried, jet milled, and sieved to obtain highly conductive and strong activated carbon. To further control its pore structure and surface properties, the activated carbon was subjected to a secondary heat treatment at 1100°C for 3 hours in a high-purity argon atmosphere.

[0035] Example 5

[0036] The preparation method of a highly conductive and high-strength activated carbon in Example 5 is as follows: 2.0 g of lignin is fully dispersed in 160 mL of deionized water, and 1.0 g of KOH is completely dissolved in 20 mL of deionized water. The two solutions are fully stirred and mixed for 8 hours, and then placed in a 110°C oven to completely dry to obtain an activated precursor. Then, the activated precursor is placed in a high-temperature tube furnace and heated at 5°C min under a high-purity argon atmosphere. -1 The sample was heated to 900℃ at a heating rate of 100℃ and activated for 2h. After the tube furnace cooled to room temperature, the activated sample was taken out and treated with 2mol L -1 The activated carbon was then immersed in hydrochloric acid, stirred at 65°C for 10 hours, and washed repeatedly with deionized water until the pH was >6.5. Finally, it was dried, jet milled, and sieved to obtain highly conductive and strong activated carbon. To further control its pore structure and surface properties, the activated carbon was subjected to a secondary heat treatment at 900°C for 5 hours in a high-purity argon atmosphere.

[0037] Example 6

[0038] The preparation method of a highly conductive and high-strength activated carbon in Example 6 is as follows: 1.0 g of lignin is fully dispersed in 80 mL of deionized water, and 1.5 g of CsOH·H2O is completely dissolved in 20 mL of deionized water. The two solutions are thoroughly stirred and mixed for 10 h, and then placed in a 110°C oven to completely dry to obtain an activated precursor. Next, the activated precursor is placed in a high-temperature tube furnace and heated at 3°C ​​min-1 under a high-purity argon atmosphere. -1 The sample was heated to 900℃ at a heating rate of 100℃ and activated for 4h. After the tube furnace cooled to room temperature, the activated sample was taken out and treated with 1mol L -1 Hydrochloric acid and 0.1 mol L -1 The activated carbon was then immersed in nitric acid, stirred at 85°C for 11 hours, and washed repeatedly with distilled water until the pH was >6.5. Finally, it was dried, jet milled, and sieved to obtain highly conductive and strong activated carbon. To further control its pore structure and surface properties, the activated carbon was subjected to a secondary heat treatment at 1300°C for 1 hour in a high-purity argon atmosphere.

[0039] Example 7

[0040] The preparation method of a highly conductive and high-strength activated carbon in Example 7 is as follows: 1.5 g of phenolic resin is dispersed in 30 mL of anhydrous ethanol, and 1.5 g of KOH is completely dissolved in 30 mL of deionized water. The two solutions are thoroughly stirred and mixed for 8 h, and then placed in a 110°C oven to completely dry to obtain an activated precursor. Next, the activated precursor is placed in a high-temperature tube furnace and heated at 5°C min-1 under a high-purity argon atmosphere. -1 The sample was heated to 700℃ at a heating rate of 100℃ and activated for 3h. After the tube furnace cooled to room temperature, the activated sample was taken out and treated with 1mol L -1 Hydrochloric acid and 0.1 mol L -1 The activated carbon was immersed in sulfuric acid, stirred at 75°C for 14 hours, and then washed with deionized water several times until the pH was greater than 6.5. Finally, after drying, air flow milling and particle size screening, the activated carbon was subjected to a secondary heat treatment at 1400°C for 1 hour in a high-purity argon atmosphere.

[0041] Example 8

[0042] The preparation method of a highly conductive and high-strength activated carbon in Example 8 is as follows: 2.0 g of phenolic resin is dispersed in 40 mL of anhydrous ethanol, and 3.0 g of CsOH·H2O is completely dissolved in 60 mL of deionized water. The two solutions are thoroughly stirred and mixed for 9 hours, and then placed in a 110°C oven to completely dry to obtain an activated precursor. Next, the activated precursor is placed in a high-temperature tube furnace and heated at 3°C ​​min-1 under a high-purity argon atmosphere. -1 The sample was heated to 700℃ at a heating rate of 100℃ and activated for 2h. After the tube furnace cooled to room temperature, the activated sample was taken out and treated with 1 mol L -1hydrochloric acid and 0.1 mol L -1 hydrofluoric acid soaking, stirring at 90℃ for 20h, adding distilled water for multiple times to wash until pH>6.5. Finally, high conductive and high strength activated carbon is obtained through drying, air flow crushing and particle size screening. In order to further regulate its pore and surface state, the activated carbon is subjected to secondary heat treatment at 1500℃ for 2h under high purity argon atmosphere.

[0043] Table 1 Examples and Comparative Examples

[0044]

[0045] The above only is the preferred embodiment of the present application, and is not limited to the application. It should be noted that for those skilled in the art, under the technical inspiration provided by the present application, other equivalent improvements can also be made, which can all achieve the purpose of the present application, and should be considered as the protection scope of the present application.

Claims

1. A highly conductive and high-strength activated carbon and a method for preparing the same, characterized in that: Follow the steps below to get: The carbon precursor is dissolved / dispersed in a compatible polar solvent to form a polymer solution or nanosol, which is labeled as solution A; the activator is dissolved in water, which is labeled as solution B; after solution A and solution B are fully stirred and mixed, they are placed in an oven and completely dried to obtain an activated precursor C; Subsequently, the activated precursor C is subjected to high-temperature activation treatment under an inert atmosphere to obtain sample A, which is then washed, purified, dried, airflow crushed and particle size screened to obtain highly conductive and high-strength activated carbon. The pore and surface state can be further controlled through secondary heat treatment modification.

2. The highly conductive and high-strength activated carbon and its preparation method according to claim 1, characterized in that: The carbon precursor is an activated carbon precursor with rich functional groups and high thermal stability, including but not limited to lignin, chitosan, phenolic resin, carbon quantum dots, oxidized asphalt, etc.; the polar solvent is deionized water, anhydrous ethanol, acetic acid solution, N,N-dimethylformamide (DMF), tetrahydrofuran (THF), etc., and the specific selection depends on the carbon precursor used; the dissolution / dispersion ratio of the carbon precursor to the polar solvent is 1:5 to 1:300 g / mL -1 The activation step is to add an activator according to a mass ratio of carbon precursor to activator of 1:0.1 to 1:4 to obtain a mixed solution, fully immerse for 8 to 10 hours and then evaporate to dryness, grind the obtained powder sample until uniform, and obtain an activated precursor C; the activator is one or a mixture of KOH and CsOH; the dispersion ratio of the activator to water is 1:20 to 1:80 g mL -1 The activated precursor C was then subjected to high temperature activation treatment under an inert atmosphere to obtain sample A. The activation heating rate was 0.1-30°C min -1 The activation temperature is 500-950°C, the holding time is 0.5-4 hours, and the activation atmosphere is a conventional inert atmosphere, including but not limited to N2 and Ar atmosphere. The washing and purification step is to use acid washing and water washing, and the acid washing solution is a mixed solution of hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and formic acid; Its main component is hydrochloric acid, and its concentration range is 0.5~3molL -1 ; Depending on the type of carbon precursor and activator, the solubility of nitric acid is 0-1.0 mol L -1 , sulfuric acid solubility is 0~0.5molL -1 The concentration of hydrofluoric acid can be 0~0.5molL -1 , the solubility of formic acid is 0~0.5molL -1 ; Immerse the sample to be washed in the pickling solution and stir at 25-95°C for 3-24 hours. Depending on the impurity content and pore structure of the activated carbon, the number of pickling times can be 1-4 times. After pickling, wash repeatedly with water (deionized water, distilled water, purified water, etc.). The pH of the washing solution after washing needs to reach above 6.

5. The secondary heat treatment temperature is 400-1600°C, and the insulation time is 0.5-5h. The heat treatment step can be implemented or not according to the requirements of the final product.

3. The highly conductive and high-strength activated carbon according to claim 1, characterized in that: Prepared according to claims 1 and 2; the activated carbon has a through-hole microporous structure and a large specific surface area (2000-3200m 2 g -1 ), high powder conductivity (800~1300Sm -1 ), high vibration / compaction density (0.4~0.7g cm -3 ) and high particle strength (50-100MPa) characteristics.

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