Porous carbon material, preparation method and application thereof, and supercapacitor

Abstract

The invention relates to a porous carbon material as well as a preparation method and application thereof. The specific surface area of the porous carbon material is 1500-3000m < 2 > / g, and pore channels are intensively distributed in a range of 0.6-2.0 nm. The preparation method of the porous carbon material comprises the following steps: (1) montmorillonite acid treatment; (2) uniformly mixing the acid-treated montmorillonite obtained in the step (1) with asphalt, and carrying out carbonization treatment to obtain a carbonized material; and (3) under the inert atmosphere condition, mixing the carbonized material with an activating agent for activation, and then washing and drying. The porous carbon material obtained by the invention has the advantages of large specific surface area, reasonable pore size distribution, high ion transmission speed and the like, and is a super-capacitor carbon material with excellent rate capability.

Description

Technical Field

[0001] The present invention relates to a porous carbon material, a preparation method thereof, an application as supercapacitor carbon in a supercapacitor, and a supercapacitor using the porous carbon material. Background Art

[0002] Capacitor carbon is a high-end activated carbon product, which has the characteristics of large specific surface area, abundant nano-scale micropores, stable surface physical and chemical properties, and large adsorption capacity. It has broad application prospects in emerging technical fields such as electronic electrodes, new catalyst carriers, energy storage, electric vehicles, and functional adsorbents. Especially as an electrode material for supercapacitors, it has higher added value. Compared with lithium batteries, the advantages of supercapacitors are more reflected in their superior rate performance, fast charge and discharge performance, and long-cycle performance. Therefore, improving the performance of supercapacitor carbon in these aspects has always been the goal pursued by people. Due to the characteristics of continuous electron migration channels and easy contact with the electrolyte of two-dimensional nano-sheet carbon materials, the prior art generally adopts the method of adding conductive materials such as carbon nanotubes and graphene to improve the capacitance performance of supercapacitor carbon. For example, both CN114597074A and CN109665523A improve the conductivity of activated carbon by adding graphene oxide to activated carbon, thereby improving the capacitance performance of capacitor carbon. CN106115694A mixes molten matrix asphalt with graphene oxide to prepare a composite asphalt-based activated carbon. The specific surface area of the obtained composite asphalt-based activated carbon is 2300 - 3200m 2 / g, the mesopore ratio is 6 - 10 microns, the nitrogen content is 1 - 3%, and the metal impurities < 100 ppm. It has a relatively high specific capacitance, but the rate performance and long-cycle performance of the obtained capacitor are poor. Moreover, the common disadvantage of the above methods is that graphene oxide and pitch coke or activated carbon need to be mixed at high temperature repeatedly for many times in the early stage to improve the uniformity of the conductive network in the composite material. The process is complex, and graphene oxide and activated carbon are independent particles of each other. Therefore, it is difficult to ensure the stability and long-cycle performance of the product.

[0003] Therefore, despite the above-mentioned many modification methods, it is difficult to ensure that the product takes into account the specific capacitance, rate discharge performance, and long-cycle performance. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the core purpose of the present invention is to provide a supercapacitor carbon that takes into account good specific capacitance, rate performance, and long-cycle performance, and a preparation method thereof.

[0005] The first aspect of the present invention provides a porous carbon material, in which the pore volume of pores with a pore diameter of 0.6 to 2 nm is greater than 50% by volume, and the ratio of the pore volume of pores with a pore diameter of 1 to 2 nm to the pore volume of pores with a pore diameter of 0.6 to 1 nm is 1 to 3, preferably 1.9 to 2.6.

[0006] The second aspect of the present invention provides a method for preparing a porous carbon material, which comprises sequentially carbonizing and activating an organic carbon source, wherein the carbonization is performed in the presence of montmorillonite.

[0007] The third aspect of the present invention provides a porous carbon material obtained by the above preparation method.

[0008] A fourth aspect of the present invention provides the use of the porous carbon material in a supercapacitor.

[0009] The fifth aspect of the present invention provides a supercapacitor, which uses the above-mentioned porous carbon material as an active electrode material.

[0010] The pores of the porous carbon material provided by the present invention are concentratedly distributed in the range of 0.6 to 2 nm, and the ratio of the pore volume of pores with a pore diameter of 1 to 2 nm to the pore volume of pores with a pore diameter of 0.6 to 1 nm is 1 to 3, thereby greatly improving the specific capacity, rate performance and long-term cycle performance of the carbon material when used as a supercapacitor active material. The reason may be that the pores with a pore diameter of 0.6 to 2 nm, especially 1 to 2 nm, are more conducive to the effective infiltration of the electrolyte, shortening the ion and charge transfer distance. The fast charge transfer speed significantly improves the rate performance of the material. A large number of pores with a pore diameter of 1 to 2 nm can also improve the capacitance and long-term cycle performance of the material.

[0011] The porous carbon material obtained by the present invention has a specific pore structure by adding montmorillonite, especially montmorillonite after acid treatment, i.e., monolayer exfoliation, during the carbonization process of the organic carbon material. The reason may be that the montmorillonite monolayer acts as a nanoscale two-dimensional confined unit during the activation process of the asphalt, so that the formation process of the supercapacitor carbon proceeds along the direction of the two-dimensional layer, hindering the relative movement of the asphalt molecules. The structural dimension of the material is fixed by the spatial partitioning effect of the montmorillonite layer, and at the same time, it plays the role of a hard template agent, which is conducive to increasing the proportion of the pore structure between 1 and 2 nm during the activation process. The prepared carbon material has pores concentrated in the range of 0.6 to 2 nm and has a long-range disordered and short-range ordered structure. When used in supercapacitors, it can ensure that the capacitor has a large capacity, a high rate discharge performance, and a good long-term cycle performance. Brief Description of the Figures

[0012] Figure 1 This is the pore size distribution diagram of the supercapacitor carbon manufactured in Example 1 of the present invention.

[0013] Figure 2 The electron microscope photograph of the supercapacitor carbon manufactured in Example 1 of the present invention.

[0014] Figure 3 The Raman spectrogram of the supercapacitor carbon manufactured in Example 1 of the present invention.

[0015] Figure 4 Shows the charge-discharge performance of the supercapacitor carbon manufactured in Example 1 of the present invention in a long cycle of 100,000 times. Detailed implementation manners

[0016] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0017] The pore channels of the porous carbon material provided in the first aspect of the present invention are concentratedly distributed in the range of 0.6 - 2 nm. The pore volume of the pores with a pore diameter of 0.6 - 2 nm in the pore structure is greater than 50% by volume, preferably not less than 60% by volume, and the ratio of the pore volume of the pores with a pore diameter of 1 - 2 nm to the pore volume of the pores with a pore diameter of 0.6 - 1 nm is 1 - 3, preferably 1.9 - 2.6.

[0018] In the present invention, unless otherwise specified, the pores with a pore diameter of 0.6 - 1 nm refer to the pores with a pore diameter greater than or equal to 0.6 nm and less than 1 nm.

[0019] In the present invention, the pore channels of the porous carbon material are concentratedly distributed in the range of 0.6 - 2 nm. The pores with a pore diameter of 0.6 - 2 nm, especially 1 - 2 nm, are beneficial to the effective infiltration of the electrolyte, shorten the ion and charge transport distance, and the fast charge transport speed significantly improves the rate performance, specific capacitance and long cycle performance of the material.

[0020] Further, the specific surface area of the porous carbon material can be 1500 - 3000 m 2 / g, preferably 1800 - 2700 m 2 / g. A suitable specific surface area can better meet the requirements of the rate performance, capacity and long cycle performance of the supercapacitor.

[0021] In the present invention, the specific surface area and pore distribution curve are measured by the method obtained through the nitrogen adsorption - desorption curve on a Micromeritics ASAP 2020 type adsorption instrument.

[0022] According to a preferred embodiment of the present invention, the D of the porous carbon material50 is 5 to 10 micrometers. The D of the porous carbon material 50 For example, it can be 5 micrometers, 6 micrometers, 7 micrometers, 8 micrometers, 9 micrometers, 10 micrometers, and the ranges composed of any two of the above.

[0023] According to a preferred embodiment of the present invention, the carbon content of the porous carbon material is more than 99% by weight.

[0024] The Raman spectrum of the porous carbon material provided by the present invention has spectral peaks only in the range of 800 - 2000 wavenumbers / cm -1 and only in the range of 1300 - 1600 wavenumbers / cm -1 within this range, and the spectral peak near 1350 wavenumbers / cm -1 has a larger peak width and a smaller peak height than the spectral peak near 1580 wavenumbers / cm -1 . Preferably, the peak width ratio of the spectral peak near 1350 wavenumbers / cm -1 to the spectral peak near 1580 wavenumbers / cm -1 is 1:0.5 - 0.95, and the peak height ratio is 1:1.05 - 1.5. In the present invention, unless otherwise specified, "nearby" refers to the error caused by factors such as acceptable instruments / operations in the present invention, for example, ±10 wavenumbers / cm -1 .

[0025] Furthermore, the size La value of the aromatic lamellae of the porous carbon material is between 4.4 and 6 nm, preferably between 4.6 and 5.8 nm.

[0026] The size La value of the aromatic lamellae of the porous carbon material refers to the diameter of the aromatic layer of the carbon graphite microcrystal. A larger La value within the above range is beneficial for shortening the ion and charge transport distances and accelerating the charge transport speed, thereby further ensuring that the capacitor has good rate performance, capacity, and long - cycle performance. In the present invention, the size La value of the aromatic lamellae is calculated by the Scherrer formula L a = 0.89×0.15406 / (B (100) cosθ (100) ) using the X - ray diffraction results of the porous carbon material, where B (100) is the full - width at half - maximum corresponding to the (100) peak of the porous carbon material; θ (100) is the Bragg angle corresponding to the (100) peak.

[0027] The porous carbon material provided by the present invention is suitable as supercapacitor carbon for supercapacitors because it has a large number of pores with a size of 0.6 - 2 nm, especially 1 - 2 nm, a large specific surface area, and a high La value.

[0028] The preparation method of the porous carbon material provided by the second aspect of the present invention includes carbonizing and activating an organic carbon source in the presence of montmorillonite, and then removing the montmorillonite and other impurities. The obtained porous carbon material has a large number of pores with a size of 0.6 - 2 nm, a relatively large specific surface area, and a relatively high La value. When used as supercapacitor carbon in a supercapacitor, a relatively high rate discharge performance can be obtained. The reason may be that the lamellar structure of montmorillonite can effectively restrict the delocalization of the organic carbon source during the carbonization process, enabling the components in the carbon source to preferentially form a planar structure, thereby promoting the growth of the material along the two-dimensional direction. At the same time, the spatial partitioning effect of the montmorillonite lamellae fixes the structural dimension of the material and plays the role of a hard template agent, increasing the proportion of the pore structure between 1 - 2 nm in the porous carbon.

[0029] The inventors of the present invention have found that acid modification of montmorillonite, on the one hand, increases the surface acidity of montmorillonite and enhances its catalytic activity for the polycondensation reaction of organic carbon sources such as pitch, and on the other hand, increases the specific surface area and porosity of montmorillonite, which is beneficial for its dispersion in organic carbon sources such as pitch, thereby ultimately improving the rate discharge performance of the carbon material. Therefore, according to a preferred embodiment of the present invention, the montmorillonite is acid-treated before carbonization with the organic carbon source, that is, the montmorillonite is preferably acid-treated montmorillonite.

[0030] Preferably, the conditions for acid modification of montmorillonite are such that the specific surface area of the acid-treated montmorillonite is 50 - 1000 m 2 / g, preferably 150 - 600 m 2 / g.

[0031] According to a specific embodiment of the present invention, the acid treatment method is to fully contact the montmorillonite raw material with an organic acid and / or an inorganic acid with or without stirring. The contact conditions include that the temperature can be 20 - 100 °C, preferably 30 - 70 °C; the acid treatment time can be 2 - 48 h, preferably 5 - 30 h, more preferably 5 - 24 h. Then, filter and wash to remove the acid remaining on the surface of the montmorillonite.

[0032] For the convenience of distinction, the present invention refers to the montmorillonite without acid treatment as the montmorillonite raw material. The montmorillonite raw material can be various existing montmorillonite products, for example, selected from at least one of sodium-based montmorillonite, calcium-based montmorillonite, sodium-calcium-based montmorillonite, lithium-based montmorillonite, magnesium-based montmorillonite, and hydrogen-based montmorillonite, preferably sodium-based montmorillonite.

[0033] Preferably, the montmorillonite has a nano-layered silicate structure.

[0034] In the preferred embodiment of the present invention, the silicon-oxygen tetrahedron and the aluminum-oxygen tetrahedron in the montmorillonite are connected by sharing oxygen atoms.

[0035] Further preferably, the thermal decomposition temperature of the montmorillonite is not lower than 650 °C.

[0036] The montmorillonite satisfying the above conditions may be at least one of sodium montmorillonite (Na-MMT), calcium montmorillonite, magnesium montmorillonite, and hydrogen montmorillonite produced by Macklin.

[0037] Further preferably, the specific surface area of the montmorillonite raw material is 20 - 300 m 2 / g, preferably 20 - 250 m 2 / g.

[0038] Further preferably, the particle diameter of the montmorillonite is 0.1 - 20 μm, preferably 0.3 - 15 μm, and more preferably 10 - 15 μm.

[0039] The acid used for the acid treatment may be selected from inorganic acids and / or organic acids, preferably inorganic acids; it may be one or more of strong acids, medium-strong acids, and weak acids. The inorganic acid may be selected from one or a mixture of two or more of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and perchloric acid, preferably nitric acid. The organic acid may be a monobasic acid or a polybasic acid with two or more carboxyl groups. For example, it may be one or a mixture of two or more of formic acid, acetic acid, succinic acid, oxalic acid, citric acid, tartaric acid, salicylic acid, and malic acid. The acid is preferably used in the form of an aqueous solution with a concentration of 0.1 - 6 mol / L, preferably 0.5 - 3 mol / L in terms of H + concentration.

[0040] Preferably, the liquid-solid ratio of the montmorillonite to the acid solution is 5 - 50 mL / g, preferably 8 - 30 mL / g, and more preferably 15 - 30 mL / g. The liquid-solid ratio of the montmorillonite to the acid solution may be 5 mL / g, 8 mL / g, 10 mL / g, 12 mL / g, 15 mL / g, 17 mL / g, 19 mL / g, 21 mL / g, 23 mL / g, 25 mL / g, 30 mL / g, 40 mL / g, 50 mL / g, and the range composed of any two of the above.

[0041] In order to remove the free acid in the acidified montmorillonite, the method of the present invention preferably further includes washing the montmorillonite after the acidification treatment. The washing is preferably washing with deionized water several times until the filtrate is neutral. After washing, drying is carried out to obtain the acid-treated montmorillonite. The drying conditions are: the drying temperature is 40 - 150 °C, preferably 40 - 110 °C; the drying time is 1 - 48 h, preferably 6 - 24 h.

[0042] In the present invention, the organic carbon source may be various organic substances that can obtain a carbon material with a porous structure after carbonization, preferably petroleum-based carbon, more preferably asphalt, and further preferably the asphalt is one or several of petroleum asphalt and coal asphalt, and particularly preferably petroleum asphalt.

[0043] Preferably, the softening point of the asphalt is 80 to 350 °C, preferably 100 to 300 °C.

[0044] Preferably, the density of the asphalt is 0.6 to 1.4 g / cm 3 , preferably 0.9 to 1.25 g / cm 3 .

[0045] According to a preferred embodiment of the present invention, the mass ratio of the organic carbon source to montmorillonite is 100 to 1:1, preferably 50 to 3:1, more preferably 20 to 3:1. The mass ratio of the organic carbon source to montmorillonite can be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 8:1, 10:1, 15:1, 20:1, 30:1, 40:1, 50:1, 60:1, 80:1, 100:1, and the ranges composed of any two of the above.

[0046] Before carbonization, the organic carbon source can be mixed uniformly with montmorillonite or acid-treated montmorillonite by means of melt blending, shearing, ball milling, etc. Preferably, melt blending and high-speed shearing are used. Further, when shear mixing, the shear rate of the high-speed shearer is 2000 to 20000 r / min, preferably 3000 to 8000 r / min. The inventors of the present invention have found that using the method of melt blending and high-speed shearing can make montmorillonite have a larger amount of single-layer structures, so as to better play a confinement role on the organic carbon source during the carbonization process, obtain a porous carbon material with a larger La value and a larger specific surface area, and thus further improve the capacity, rate performance and long-cycle performance of the supercapacitor.

[0047] Further, the temperature when the organic carbon source is mixed with montmorillonite or acid-treated montmorillonite can be 100 to 350 °C, preferably 150 to 300 °C; the mixing time can be 0.2 to 3 h, preferably 0.5 to 2 h.

[0048] In the present invention, the carbonization treatment is preferably carried out in an inert atmosphere in the absence of oxygen. The inert atmosphere can be nitrogen and / or inert gas, and the inert gas is one or more of helium, neon, argon, krypton, and xenon.

[0049] The carbonization treatment conditions include: the carbonization treatment temperature can be 200 to 650 °C, preferably 300 to 600 °C; further, the heating rate can generally be controlled at 1 to 20 °C / min, preferably 5 to 15 °C / min. The carbonization treatment time can be 40 to 500 minutes. Here, the carbonization treatment time refers to the constant-temperature carbonization time and does not include the heating and cooling times.

[0050] The carbonization treatment can be carried out at one temperature or in two stages at two temperatures, preferably at two temperatures.

[0051] When the carbonization treatment is carried out at one temperature, the treatment temperature can be 200 - 650 °C, preferably 300 - 600 °C; the further heating rate can generally be controlled at 1 - 20 °C / min, preferably 2 - 15 °C / min; the further gas flow rate can be 50 - 500 mL / min, preferably 200 - 500 mL / min; the carbonization treatment time can be 20 - 300 min, preferably 60 - 300 min.

[0052] When the carbonization treatment is carried out in two stages at two temperatures, the first-stage carbonization temperature can be 300 - 550 °C, preferably 450 - 520 °C; the further heating rate can generally be controlled at 1 - 15 °C / min, preferably 5 - 15 °C / min; the further gas flow rate can be 100 - 500 mL / min, preferably 200 - 500 mL / min; the carbonization treatment time can be 10 - 100 min, preferably 20 - 60 min.

[0053] The second-stage carbonization temperature can be 400 - 650 °C, preferably 500 - 600 °C; the further heating rate can generally be controlled at 5 - 20 °C / min, preferably 5 - 15 °C / min; the further gas flow rate can be 100 - 500 mL / min, preferably 200 - 300 mL / min; the carbonization treatment time can be 40 - 200 min, preferably 60 - 200 min.

[0054] According to a preferred embodiment of the present invention, the temperature of the first-stage carbonization is 50 - 150 °C lower than that of the second stage, and the time is 20 - 180 minutes shorter. Adopting this method can further improve the specific capacity, rate charge-discharge performance and long-cycle performance of the obtained carbon material.

[0055] Since no obvious two-phase separation occurs in the solid material obtained after the carbonization treatment, it is a uniform black mixture. In order to obtain the required porous carbon material, an activation treatment is also required after carbonization.

[0056] Preferably, after the carbonization treatment is completed, it is first cooled to room temperature or ambient temperature. There is no limitation on the cooling method, and it can be natural cooling or the material can be cooled by means of external heat exchange. After cooling, it is further preferred to crush the obtained solid material to a particle size of 10 - 100 μm, preferably 10 - 30 μm, and then carry out the activation.

[0057] The activator used for activation is preferably at least one of hydroxides and carbonates containing alkali metals and / or alkaline earth metals. Preferably, the activator is a granular solid with a particle size generally of 10 - 300 μm. Specifically, the activator can be one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, potassium bicarbonate, sodium bicarbonate, calcium hydroxide, and magnesium hydroxide, preferably one or more of sodium hydroxide, potassium hydroxide, and potassium carbonate.

[0058] Preferably, the activation treatment conditions include that the activation temperature can be 600 - 1000 °C, preferably 700 - 900 °C; further, the activation heating rate is generally controlled at 1 - 10 °C / min, preferably 8 - 10 °C / min; the activation time can be 20 - 180 min, preferably 20 - 120 min. Further preferably, the activation is carried out in the absence of oxygen, preferably in an inert atmosphere. The inert atmosphere can be nitrogen and / or inert gas, and the inert gas is one or more of helium, neon, argon, krypton, and xenon. The gas flow rate can be 100 - 500 mL / min, preferably 200 - 500 mL / min.

[0059] Further preferably, the weight ratio of the carbonized material to the activator is 1:0.2 - 10, preferably 1:1.5 - 3, and more preferably 1:2 - 3. The weight ratio of the carbonized material to the activator can be 1:0.2, 1:1, 1:1.5, 1:1.7, 1:1.8, 1:2, 1:2.1, 1:2.2, 1:2.5, 1:2.6, 1:2.8, 1:3, 1:4, 1:5, 1:10, and the ranges composed of any two of the above.

[0060] According to a preferred embodiment of the present invention, the method further includes washing the activated product. The main purpose of washing is to remove the residual montmorillonite and the alkaline substances generated during the reaction through washing, and expose the rich pore structure formed during the activation process. The washing can include a first-stage water wash, a second-stage acid wash, and a third-stage water wash. Among them, the temperature of the first-stage water wash is 30 - 100 °C, preferably 60 - 100 °C. The first-stage water wash is preferably carried out under the conditions of condensation reflux and stirring. The time of the first-stage water wash is 2 - 48 h, preferably 5 - 24 h. The liquid-solid mass ratio of the first-stage water wash is 10 - 50:1, preferably 10 - 30:1. The acid solution used in the second-stage acid wash can be one or several of hydrochloric acid, nitric acid, sulfuric acid, and acetic acid. The mass fraction of the acid solution can be 0.5 - 20%, preferably 1 - 10%. The liquid-solid mass ratio of the acid solution to the solid material can be 5 - 30:1, preferably 5 - 20:1. The third-stage water wash is to wash with deionized water or ultrapure water for several times. The liquid-solid mass ratio of water to the solid-phase material during the water wash can be 10 - 50:1, preferably 10 - 30:1; the third-stage water wash is carried out at room temperature.

[0061] According to a preferred embodiment of the present invention, the method further includes drying the washed product. The drying temperature can be 60 - 150 °C, preferably 60 - 120 °C; the drying time is 1 - 24 h, preferably 4 - 12 h.

[0062] According to a specific embodiment of the present invention, the preparation method of the porous carbon material includes the following steps:

[0063] (1) Under an inert atmosphere condition, carbonize the organic carbon material in the presence of montmorillonite to obtain a carbonized material;

[0064] (2) Contact the carbonized material with an activator for activation, and then perform washing and drying.

[0065] According to a particularly preferred embodiment of the present invention, the preparation method of the porous carbon material includes the following steps:

[0066] (1) Contact montmorillonite with an acid solution for acid treatment to obtain acid-treated montmorillonite;

[0067] (2) Under an inert atmosphere, mix the acid-treated montmorillonite obtained in step (1) with an organic carbon source, preferably pitch, for carbonization treatment to obtain a carbonized material;

[0068] (3) Under an inert atmosphere, mix the carbonized material with an activator for activation, and then perform washing and drying.

[0069] The third aspect of the present invention provides a porous carbon material prepared by the above preparation method.

[0070] The porous carbon material obtained by the above method has a large number of pores with a size of 0.6 - 2 nm, especially 1 - 2 nm, and has a large specific surface area and La value, and is suitable as supercapacitor carbon for supercapacitors. Therefore, the fourth aspect of the present invention provides the application of the above porous carbon material in supercapacitors, preferably as an active electrode material.

[0071] The fifth aspect of the present invention provides a supercapacitor, which uses the above porous carbon material as an active electrode material.

[0072] When the obtained supercapacitor is an organic-based button-type supercapacitor, at a current density of 1 A / g, the mass specific capacitance can be 25 - 45 F / g, preferably 35 - 45 F / g; when the current density increases to 15 A / g, the mass specific capacitance of the organic-based button-type supercapacitor can be 20 - 40 F / g, preferably 30 - 39 F / g, and the specific capacitance retention rate after 100,000 charge-discharge cycles can be 78 - 95%, preferably 85 - 95%.

[0073] The present invention will be further described below through examples.

[0074] In the examples, the specific surface area and pore size distribution curves of the samples were obtained from the nitrogen adsorption - desorption curves on a Micromeritics ASAP 2020 adsorption instrument. The operating temperature was -196 °C (liquid nitrogen temperature). The samples were pre - dehydrated at 300 °C under nitrogen protection before testing. The specific surface area and pore size distribution were calculated by the BET method and the DFT method respectively.

[0075] The electron microscope was tested using a JEOL field - emission scanning electron microscope JEM7500M made in Japan; Raman was tested using an HR - 800 Raman spectrometer produced by HORIBA Jobin Yvon in France.

[0076] The electrochemical test method is as follows: Activated carbon, conductive agent acetylene black, and binder PVDF (polyvinylidene fluoride) were mixed evenly according to a mass ratio of 8:1:1, coated on carbon - coated aluminum foil, dried and sliced. The areal density of the electrode was 2.6 mg / cm 2 (The areal density of the electrode = (weight after coating - weight before coating) / coating area), and an organic - system button - type supercapacitor was assembled. The electrolyte was 1 mol / L tetraethylammonium tetrafluoroborate dissolved in propylene carbonate. Then, electrochemical performance tests and long - cycle performance tests were carried out on a Neware electrochemical tester (model BTS - 5V50mA).

[0077] Example 1

[0078] Accurately weigh 5 g of montmorillonite (Na - MMT, produced by Macklin, specific surface area is 240 m 2 / g, average particle size is 10 μm) and place it in a 250 - mL single - neck flask. Add 150 mL of a nitric acid solution with a concentration of 2 mol / L, stir and acidify at a constant temperature of 50 °C for 24 h, cool to room temperature (25 °C, the same below), filter by suction, wash with deionized water until neutral, dry at 110 °C for 12 h, grind and sieve to obtain acidified montmorillonite with a particle size less than 15 μm, and the specific surface area is 485 m 2 / g.

[0079] Weigh 20 g of petroleum asphalt (softening point is 190 °C, density is 1.12 g / cm 3 ), heat it to the molten state. Under stirring conditions, weigh 4 g of the above - mentioned acidified montmorillonite and add it to the molten asphalt. Use a high - speed shear machine to shear the molten blend at a shear rate of 6000 r / min for 1 h, and take it out in a solid state after cooling to room temperature as the first material.

[0080] Load the first material into a quartz ark, place it in a carbonization furnace. After replacing the air in the activation furnace with nitrogen at a flow rate of 500 mL / min for 20 min, heat it at a rate of 5 °C / min to 480 °C at a nitrogen flow rate of 300 mL / min, keep it at a constant temperature for carbonization for 40 min, then heat it at a rate of 10 °C / min to 590 °C, keep it at a constant temperature for carbonization for 60 min, cool it to room temperature. The carbonization product is pulverized to the micron level in a jet mill and used as the second material.

[0081] Mix 15 g of the second material and 45 g of KOH evenly, load them into a corundum ark, place it in the activation furnace. After replacing the air in the activation furnace with nitrogen at a flow rate of 500 mL / min for 20 min, heat it at a rate of 10 °C / min to 900 °C at a nitrogen flow rate of 200 mL / min, keep it at a constant temperature for activation for 40 min, turn off the heating, take it out after cooling to room temperature, which is the activation product. Transfer the activation product to a flask, add deionized water according to the liquid-solid mass ratio of 15:1, heat it to 100 °C and condense and reflux, stir magnetically for 5 h, filter by suction, then wash it with water with a liquid-solid mass ratio of 40:1, then filter and wash it with dilute hydrochloric acid with a mass fraction of 5% according to the liquid-solid mass ratio of 15:1, and then wash it with water with a liquid-solid mass ratio of 40:1. The obtained filter cake is dried in a forced-air drying oven at 105 °C for 8 h to obtain porous carbon. Grind the porous carbon into D 50 with a particle size of 8 - 10 μm, remove metal ions through a magnetic separator to obtain pitch-based supercapacitor carbon.

[0082] The pore size distribution diagram, electron microscope photo, and Raman spectrum diagram of the obtained supercapacitor carbon are respectively as Figure 1 、 Figure 2 and Figure 3 shown. It can be seen from Figure 1 that the total proportion of pores < 0.6 nm and > 2.0 nm is 28% by volume, and the pores with a size of 1.0 - 2.0 nm are 1.9 times the proportion of micropores with a size of 0.6 - 1.0 nm. It can be seen from Figure 2 that the prepared porous carbon material has an obvious lamellar structure, and is long-range disordered and short-range ordered. It can be seen from Figure 3 that the Raman spectrum of the porous carbon material only shows spectral peaks in the range of 800 - 2000 wavenumbers / cm -1 in the range of 1300 - 1600 wavenumbers / cm -1 , and the spectral peak near 1350 wavenumbers / cm -1 has a larger peak width and a smaller peak height than the spectral peak near 1580 wavenumbers / cm -1 ; specifically, the peak width ratio of the spectral peak near 1300 wavenumbers / cm -1 to the spectral peak near 1600 wavenumbers / cm -1 is 1:0.71, and the peak height ratio is 1:1.11.

[0083] In addition, the specific surface area of the obtained supercapacitor carbon was measured to be 2363 m 2 / g, and the size La of the aromatic lamella was 4.9 nm.

[0084] After electrochemical testing, when the current density was 1 A / g, the mass specific capacitance of the organic button-type supercapacitor was 42.5 F / g; when the current density increased to 15 A / g, the mass specific capacitance of the organic button-type supercapacitor was 39.0 F / g; the specific capacitance retention rate was 91.8%, and the specific capacitance retention rate after 100,000 charge-discharge cycles was 89.7% (see Figure 4 ).

[0085] Example 2

[0086] Accurately weigh 5 g of montmorillonite (Ca-MMT, produced by Macklin, with a specific surface area of 190 m 2 / g and an average particle size of 15 μm) and place it in a 150 mL single-neck flask. Add 75 mL of a hydrochloric acid solution with a concentration of 3 mol / L, stir and acidify at a constant temperature of 70 °C for 15 h, cool to room temperature and filter by suction, wash with deionized water until neutral, dry at 110 °C for 12 h, grind and sieve to obtain acidified montmorillonite with a particle size less than 15 μm, and the specific surface area is 369 m 2 / g.

[0087] Weigh 20 g of asphalt (softening point is 280 °C, density is 1.21 g / cm 3 ), heat it to 300 °C, and under stirring conditions, weigh 1 g of acidified montmorillonite and add it to the molten asphalt. Use a high-speed shear machine to shear the molten blend at a shear rate of 3000 r / min for 2 h, cool to room temperature and take it out in a solid state as the first material.

[0088] Put the first material into a quartz ark, place it in a carbonization furnace, use nitrogen to displace the air in the activation furnace at a flow rate of 500 mL / min for 20 min, then at a rate of 300 mL / min of nitrogen flow rate, heat it to 450 °C at a rate of 2 °C / min, keep it at a constant temperature for carbonization for 60 min, then heat it to 550 °C at a rate of 15 °C / min, keep it at a constant temperature for carbonization for 120 min, cool to room temperature, and crush the carbonization product to the micron level in an air flow crusher as the second material.

[0089] Mix 15 g of the second material and 38 g of KOH evenly, load them into a corundum ark, place it in an activation furnace. After replacing the air in the activation furnace with nitrogen at a flow rate of 500 mL / min for 20 min, heat it to 800 °C at a rate of 8 °C / min under a nitrogen flow rate of 300 mL / min, keep it at a constant temperature for activation for 120 min, turn off the heating, take it out after cooling to room temperature, and it is the activated product. Transfer the activated product to a flask, add deionized water according to a liquid-solid ratio of 10:1, heat it to 70 °C and carry out condensation reflux, stir magnetically for 10 h, perform hot filtration, then wash it with ultrapure water with a liquid-solid mass ratio of 40:1, and finally carry out suction filtration and washing with 5% dilute hydrochloric acid according to a liquid-solid mass ratio of 15:1, and then wash it with ultrapure water with a liquid-solid mass ratio of 40:1. The obtained filter cake is dried in a forced-air drying oven at 120 °C for 4 h to obtain porous carbon. Grind the porous carbon into particles with a size of D 50 of 8 - 10 μm, remove excess metal ions through a magnetic separator to obtain pitch-based supercapacitor carbon. The electron microscope photos and Raman spectrograms of the obtained supercapacitor carbon are respectively consistent with Figure 2 and Figure 3 basically.

[0090] The specific surface area of the obtained supercapacitor carbon is 2162 m 2 / g. The total proportion of pores less than 0.6 nm and pores greater than 2.0 nm is 25%. The pores with a size of 1.0 - 2.0 nm are 2.1 times the proportion of micropores with a size of 0.6 - 1.0 nm, and the size of the aromatic lamella is 4.6 nm.

[0091] After electrochemical testing, when the current density is 1 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 39.3 F / g; when the current density increases to 15 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 35.3 F / g, and the specific capacitance retention rate is 89.8%. After 100,000 charge-discharge cycles, the specific capacitance retention rate is 87.6%.

[0092] Example 3

[0093] Accurately weigh 5 g of montmorillonite (Na-MMT, produced by Macklin, specific surface area is 240 m 2 / g, average particle size is 10 μm) and place it in a 100 mL single-neck flask, add 50 mL of sulfuric acid solution with a concentration of 1.5 mol / L, stir and acidify it at a constant temperature of 40 °C for 30 h, cool it to room temperature and carry out suction filtration, wash it with deionized water until neutral, dry it at 105 °C for 12 h, grind and sieve it to obtain acidified montmorillonite with a particle size less than 15 μm, and the specific surface area is 503 m 2 / g.

[0094] Weigh 20 g of petroleum pitch (softening point is 240 °C, density is 1.18 g / cm 3) Heat to 250 °C. Under stirring conditions, weigh 5.7 g of acidified montmorillonite and add it to the molten asphalt. Use a high-speed shearer to shear the molten blend at a shear rate of 5000 r / min for 2 h. After cooling to room temperature, take it out in a solid state as the first material.

[0095] Load the first material into a quartz boat and place it in a carbonization furnace. After displacing the air in the activation furnace with nitrogen at a flow rate of 500 mL / min for 20 min, heat it to 520 °C at a rate of 8 °C / min under a nitrogen flow rate of 200 mL / min, hold the temperature for carbonization for 20 min, then heat it to 600 °C at a rate of 5 °C / min, hold the temperature for carbonization for 80 min, cool to room temperature, and co-crush the carbonized product in a jet mill to a micron-level homogeneous mixture as the second material.

[0096] Uniformly mix 15 g of the second material and 30 g of KOH, load it into a corundum boat, place it in an activation furnace. After displacing the air in the activation furnace with nitrogen at a flow rate of 500 mL / min for 20 min, heat it to 850 °C at a rate of 8 °C / min under a nitrogen flow rate of 300 mL / min, hold the temperature for activation for 60 min, turn off the heating, take it out after cooling to room temperature as the activated product. Transfer the activated product to a flask, add deionized water according to a liquid-to-solid ratio of 30:1, heat to 100 °C and condense and reflux, stir magnetically for 12 h, perform hot filtration, then wash with ultrapure water with a liquid-to-solid mass ratio of 40:1, finally filter and wash with 5% dilute hydrochloric acid according to a liquid-to-solid mass ratio of 15:1, and then wash with ultrapure water with a liquid-to-solid mass ratio of 40:1. The obtained filter cake is dried in a blast drying oven at 105 °C for 8 h to obtain porous carbon. Grind the porous carbon into D 50 with a size of 8 - 10 μm, remove the excess metal ions through a magnetic separator to obtain pitch-based supercapacitor carbon. The SEM images and Raman spectra of the obtained supercapacitor carbon are respectively Figure 2 and Figure 3 basically the same.

[0097] The specific surface area of the obtained supercapacitor carbon is 1923 m 2 / g. The total proportion of pores <0.6 nm and >2.0 nm is 30%. The pores of 1.0 - 2.0 nm are 2.6 times the proportion of micropores of 0.6 - 1.0 nm, and the size of the aromatic lamella is 5.1 nm.

[0098] After electrochemical testing, at a current density of 1 A / g, the mass specific capacitance of the organic-based button supercapacitor is 35.4 F / g; when the current density increases to 15 A / g, the mass specific capacitance of the organic-based button supercapacitor is 31.6 F / g, and the specific capacitance retention rate is 89.0%. After 100,000 charge-discharge cycles, the specific capacitance retention rate is 88.3%.

[0099] Example 4

[0100] Accurately weigh 10 g of calcium-based montmorillonite (Ca-MMT, specific surface area is 190 m 2 / g, average particle size is 15 μm) and place it in a 200 mL single-neck flask. Add 120 mL of hydrochloric acid solution with a concentration of 0.5 mol / L, stir and acidify at a constant temperature of 100 °C for 30 h, cool to room temperature and filter by suction, wash with deionized water until neutral, dry at 105 °C for 12 h, grind and sieve to obtain acidified montmorillonite with a particle size less than 15 μm, and the specific surface area is 352 m 2 / g.

[0101] Weigh 30 g of petroleum asphalt (softening point is 150 °C, density is 1.08 g / cm 3 ), heat it to 250 °C, and under stirring conditions, weigh 0.75 g of acidified montmorillonite and add it to the molten asphalt, mechanically stir for 2 h, take it out in a solid state after cooling to room temperature, and it is the first material.

[0102] Put the first material into a quartz boat, place it in a carbonization furnace, use nitrogen to displace the air in the activation furnace at a flow rate of 500 mL / min for 20 min, then at a rate of 200 mL / min of nitrogen flow rate, heat it to 490 °C at a rate of 3 °C / min, keep it at a constant temperature for carbonization for 30 min, then heat it to 650 °C at a rate of 8 °C / min, keep it at a constant temperature for carbonization for 100 min, cool to room temperature, and crush the carbonized product to the micron level in a jet mill and use it as the second material.

[0103] Mix 20 g of the second material and 36 g of KOH evenly, put them into a corundum boat, place it in an activation furnace, use nitrogen to displace the air in the activation furnace at a flow rate of 500 mL / min for 20 min, then at a rate of 250 mL / min of nitrogen flow rate, heat it to 820 °C at a rate of 10 °C / min, keep it at a constant temperature for activation for 100 min, turn off the heating, take it out after cooling to room temperature, and it is the activated product. Transfer the activated product to a flask, add deionized water according to the liquid-solid ratio of 30:1, heat it to 100 °C and condense and reflux, stir magnetically for 12 h, filter by suction while it is hot, then wash with ultrapure water with a liquid-solid mass ratio of 30:1, finally filter and wash with dilute hydrochloric acid with a mass fraction of 5% according to the liquid-solid mass ratio of 15:1, and then wash with ultrapure water with a liquid-solid mass ratio of 30:1. The obtained filter cake is dried in a forced-air drying oven at 105 °C for 6 h to obtain porous carbon. Grind the porous carbon into D 50 with a size of 8 - 10 μm, and remove the excess metal ions through a magnetic separator to obtain asphalt-based supercapacitor carbon.

[0104] The specific surface area of the obtained supercapacitor carbon is 1787 m 2 / g, the total proportion of pores with a size less than 0.6 nm and pores with a size greater than 2.0 nm is 39%, the pores with a size of 1.0 - 2.0 nm are 1.7 times the proportion of micropores with a size of 0.6 - 1.0 nm, and the size of the aromatic lamella is 4.4 nm.

[0105] After electrochemical testing, when the current density is 1 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 27.1 F / g; when the current density increases to 15 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 22.6 F / g, the retention rate of specific capacitance is 83.3%, and the retention rate of specific capacitance after 100,000 charge-discharge cycles is 80.5%.

[0106] Example 5

[0107] Weigh 15 g of petroleum asphalt (softening point is 215 °C, density is 1.14 g / cm 3 ), heat it to 260 °C, and under stirring conditions, weigh 1.5 g of amino montmorillonite (H-MMT, specific surface area is 485 m 2 / g, average particle size is 15 μm) and add it to the molten asphalt. The high-speed shearer shears the molten blend at a shear rate of 4000 r / min for 2 h, and after cooling to room temperature, it is taken out in a solid state as the first material.

[0108] Put the first material into a quartz ark and place it in a carbonization furnace. After replacing the air in the activation furnace with nitrogen at a flow rate of 500 mL / min for 20 min, under a nitrogen flow rate of 300 mL / min, heat it to 500 °C at a rate of 6 °C / min, keep it at a constant temperature for carbonization for 80 min, then heat it to 610 °C at a rate of 12 °C / min, keep it at a constant temperature for carbonization for 150 min, cool it to room temperature, and the carbonization product is crushed to the micron level in a jet mill and used as the second material.

[0109] Mix 10 g of the second material and 28 g of KOH evenly, put them into a corundum ark, place it in an activation furnace, after replacing the air in the activation furnace with nitrogen at a flow rate of 500 mL / min for 20 min, under a nitrogen flow rate of 200 mL / min, heat it to 750 °C at a rate of 10 °C / min, keep it at a constant temperature for activation for 90 min, turn off the heating, take it out after cooling to room temperature as the activated product. Transfer the activated product to a flask, add deionized water according to a liquid-solid ratio of 30:1, heat it to 100 °C and condense and reflux, stir magnetically for 12 h, perform hot suction filtration, then wash it with ultrapure water with a liquid-solid mass ratio of 40:1, finally perform suction filtration and washing with 5% dilute hydrochloric acid according to a liquid-solid mass ratio of 20:1, and then wash it with ultrapure water with a liquid-solid mass ratio of 30:1. The obtained filter cake is dried in a forced-air drying oven at 105 °C for 6 h to obtain porous carbon. Grind the porous carbon into D 50It is 8 - 10 μm. After removing excess metal ions by a magnetic separator, pitch-based supercapacitor carbon is obtained.

[0110] The specific surface area of the obtained supercapacitor carbon is 2069 m 2 / g. The total proportion of pores with <0.6 nm and pores >2.0 nm is 38%. The pores with 1.0 - 2.0 nm are 2.0 times the proportion of micropores with 0.6 - 1.0 nm. The size of the aromatic lamella is 4.7 nm.

[0111] After electrochemical testing, at a current density of 1 A / g, the mass specific capacitance of the organic button-type supercapacitor is 35.2 F / g; when the current density increases to 15 A / g, the mass specific capacitance of the organic button-type supercapacitor is 29.6 F / g, and the specific capacitance retention rate is 84.1%. After 100,000 charge-discharge cycles, the specific capacitance retention rate is 82.6%.

[0112] Example 6

[0113] Accurately weigh 10 g of magnesium-based montmorillonite (Mg-MMT, specific surface area is 190 m 2 / g, average particle size is 8 μm) and place it in a 150 mL single-neck flask. Add 80 mL of acetic acid solution with a concentration of 3 mol / L, stir and acidify at a constant temperature of 60 °C for 18 h, cool to room temperature and filter by suction, wash with deionized water until neutral, dry at 110 °C for 12 h, grind and sieve to obtain acidified montmorillonite with a particle size less than 15 μm, and the specific surface area is 367 m 2 / g.

[0114] Weigh 20 g of petroleum pitch (softening point is 230 °C, density is 1.17 g / cm 3 ), heat it to 270 °C, and under stirring conditions, weigh 5 g of acidified montmorillonite and add it to the molten pitch. Use a high-speed shearer to shear the molten blend at a shear rate of 8000 r / min for 0.5 h, take it out in a solid state after cooling to room temperature, and it is the first material.

[0115] Put the first material into a quartz boat, place it in a carbonization furnace. After replacing the air in the activation furnace with nitrogen at a flow rate of 500 mL / min for 20 min, heat it to 580 °C at a rate of 5 °C / min under a nitrogen flow rate of 250 mL / min, keep it at a constant temperature for carbonization for 300 min, cool to room temperature, and crush the carbonization product to the micron level in a jet mill as the second material.

[0116] 16 g of the second material and 35 g of KOH were uniformly mixed, loaded into a corundum ark, placed in an activation furnace. After displacing the air in the activation furnace with nitrogen at a flow rate of 500 mL / min for 20 min, the temperature was raised to 880 °C at a rate of 8 °C / min under a nitrogen flow rate of 200 mL / min, and the activation was carried out at a constant temperature for 60 min. Then the heating was turned off, and after cooling to room temperature, it was taken out as the activated product. The activated product was transferred to a flask, deionized water was added according to a liquid-solid ratio of 30:1, heated to 100 °C and condensed and refluxed, magnetically stirred for 12 h, hot filtered, then washed with ultrapure water with a liquid-solid mass ratio of 40:1, and finally filtered and washed with 5% dilute hydrochloric acid according to a liquid-solid mass ratio of 15:1, and then washed with ultrapure water with a liquid-solid mass ratio of 40:1. The obtained filter cake was dried in a blast drying oven at 105 °C for 8 h to obtain porous carbon. The porous carbon was ball-milled and pulverized to D 50 to 8 - 10 μm, and the excess metal ions were removed by a magnetic separator to obtain pitch-based supercapacitor carbon.

[0117] The specific surface area of the obtained supercapacitor carbon was 1982 m 2 / g. The total proportion of pores <0.6 nm and pores >2.0 nm was 28%. The pores of 1.0 - 2.0 nm were 1.8 times the proportion of micropores of 0.6 - 1.0 nm, and the size of the aromatic lamella was 4.4 nm.

[0118] After electrochemical testing, at a current density of 1 A / g, the mass specific capacitance of the organic system button-type supercapacitor was 28.7 F / g; when the current density increased to 15 A / g, the mass specific capacitance of the organic system button-type supercapacitor was 23.1 F / g, and the specific capacitance retention rate was 80.5%. After 100,000 charge-discharge cycles, the specific capacitance retention rate was 79.2%.

[0119] Example 7

[0120] 8 g of pitch (softening point 260 °C, density 1.20 g / cm 3 ) was weighed and heated to 280 °C. Under stirring conditions, 1 g of Na-MMT (produced by Macklin, specific surface area 240 m 2 / g, average particle size 10 μm) was added to the molten pitch, and the molten blend was sheared at a shear rate of 6000 r / min for 1.5 h with a high-speed shearer. After cooling to room temperature, it was taken out in a solid state as the first material.

[0121] Load the first material into a quartz ark, place it in a carbonization furnace. After displacing the air in the activation furnace with nitrogen at a flow rate of 500 mL / min for 20 min, heat it to 300 °C at a rate of 5 °C / min under a nitrogen flow rate of 250 mL / min, keep it at a constant temperature for carbonization for 80 min, then heat it to 550 °C at a rate of 10 °C / min and keep it at a constant temperature for carbonization for 100 min. Cool it to room temperature. After the carbonized product is pulverized to the micron level in a jet mill, it is used as the second material.

[0122] Mix 8 g of the second material and 32 g of KOH evenly, load them into a corundum ark, place it in an activation furnace. After displacing the air in the activation furnace with nitrogen at a flow rate of 500 mL / min for 20 min, heat it to 800 °C at a rate of 7 °C / min under a nitrogen flow rate of 300 mL / min, keep it at a constant temperature for activation for 70 min, turn off the heating, take it out after cooling to room temperature, and it is the activated product. Transfer the activated product to a flask, add deionized water according to a liquid-solid ratio of 30:1, heat it to 100 °C and condense and reflux, stir magnetically for 12 h, carry out hot filtration, then wash it with ultrapure water with a liquid-solid mass ratio of 40:1, and finally carry out suction filtration and washing with 5% dilute hydrochloric acid according to a liquid-solid mass ratio of 15:1, and then wash it with ultrapure water with a liquid-solid mass ratio of 40:1. The obtained filter cake is dried in a blast drying oven at 105 °C for 8 h to obtain porous carbon. Grind the porous carbon into D 50 with a particle size of 8 - 10 μm, remove the excess metal ions through a magnetic separator to obtain pitch-based supercapacitor carbon.

[0123] The specific surface area of the obtained supercapacitor carbon is 1832 m 2 / g. The total proportion of pores with <0.6 nm and >2.0 nm is 40%. The pores with 1.0 - 2.0 nm are 3 times the proportion of micropores with 0.6 - 1.0 nm. The size of the aromatic lamella is 4.5 nm.

[0124] After electrochemical testing, when the current density is 1 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 24.3 F / g; when the current density increases to 15 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 19.4 F / g, and the specific capacitance retention rate is 79.7%. After 100,000 charge-discharge cycles, the specific capacitance retention rate is 78.6%.

[0125] Comparative Example 1

[0126] According to the method of Example 1, the difference is that montmorillonite is not added during the carbonization process, the step of acidifying montmorillonite is not included, and the petroleum pitch is directly carbonized and activated to obtain supercapacitor carbon.

[0127] The specific surface area of the obtained supercapacitor carbon is 2184 m 2 / g, the total proportion of pores with <0.6 nm and >2.0 nm is 51%, the pores with 1.0 - 2.0 nm are 1.7 times the proportion of micropores with 0.6 - 1.0 nm, and the size of the aromatic lamella is 4.3 nm.

[0128] After electrochemical testing, when the current density is 1 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 38.7 F / g; when the current density increases to 15 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 28.7 F / g, the specific capacitance retention rate is 74.2%, and the specific capacitance retention rate after 100,000 charge-discharge cycles is 68.5%.

[0129] Comparative Example 2

[0130] According to the method of Example 1, the difference is that the mixed system of acidified montmorillonite and asphalt is directly activated to obtain supercapacitor carbon without going through the carbonization step.

[0131] The specific surface area of the obtained supercapacitor carbon is 2008 m 2 / g, the total proportion of pores with <0.6 nm and >2.0 nm is 42%, the pores with 1.0 - 2.0 nm are 3.5 times the proportion of micropores with 0.6 - 1.0 nm, and the size of the aromatic lamella is 4.1 nm.

[0132] After electrochemical testing, when the current density is 1 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 36.9 F / g; when the current density increases to 15 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 26.6 F / g, the specific capacitance retention rate is 72.1%, and the specific capacitance retention rate after 100,000 charge-discharge cycles is 67.8%.

[0133] Comparative Example 3

[0134] According to the method of Example 1, the difference is that montmorillonite is replaced by the same weight of silica to obtain supercapacitor carbon.

[0135] The specific surface area of the obtained supercapacitor carbon is 648 m 2 / g, the total proportion of pores with <0.6 nm and >2.0 nm is 52%, the pores with 1.0 - 2.0 nm are 3.4 times the proportion of micropores with 0.6 - 1.0 nm, and the size of the aromatic lamella is 4.0 nm.

[0136] After electrochemical testing, when the current density is 1 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 12 F / g; when the current density increases to 15 A / g, the mass specific capacitance of the organic system button-type supercapacitor is 5.3 F / g, the specific capacitance retention rate is 41.7%, and the specific capacitance retention rate after 100,000 charge-discharge cycles is 23.2%.

[0137] Comparative Example 4

[0138] The porous carbon material was prepared according to the method of Example 1 of CN106115694A. As a result, the specific surface area of the obtained porous carbon material was 3167 m² / g, the mesopore ratio of 2 - 50 nm was 63 vol%, the total proportion of pores < 0.6 nm and > 2.0 nm was 82%, the pores of 1.0 - 2.0 nm were 1.1 times the proportion of micropores of 0.6 - 1.0 nm, and the size of the aromatic lamella was 4.0 nm.

[0139] After electrochemical testing, when the current density was 1 A / g, the mass specific capacitance of the organic system button-type supercapacitor was 45 F / g; when the current density increased to 15 A / g, the mass specific capacitance of the organic system button-type supercapacitor was 29.9 F / g, the specific capacitance retention rate was 66.4%, and the specific capacitance retention rate after 100,000 charge-discharge cycles was 68.5%.

[0140] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A porous carbon material, wherein the pore volume of pores with a pore diameter of 0.6 to 2 nm is greater than 50% by volume, preferably not less than 60% by volume, and the ratio of the pore volume of pores with a pore diameter of 1 to 2 nm to the pore volume of pores with a pore diameter of 0.6 to 1 nm is 1 to 3, preferably 1.9 to 2.

6.

2. The porous carbon material according to claim 1, wherein The specific surface area of ​​the porous carbon material is 1500~3000m 2 / g, preferably 1800~2700 m 2 / g.

3. The porous carbon material according to claim 1 or 2, wherein: The size La value of the aromatic sheet layer of the porous carbon material is between 4.4 and 6 nm, preferably between 4.6 and 5.8 nm.

4. The porous carbon material according to claim 1, 2 or 3, wherein: The D of the porous carbon material 50 The particle size is 5 to 10 microns, and the carbon content is more than 99% by weight.

5. The porous carbon material according to any one of claims 1 to 4, wherein: The Raman spectrum of the porous carbon material is between 800 and 2000 wavenumbers / cm -1 The range is only between 1300 and 1600 wavenumbers / cm -1 The peak appears in the range of 1350 wavenumber / cm -1 The spectral peak near 1580 wavenumber / cm -1 The peak width near the peak is larger and the peak height is smaller; preferably, 1350 wavenumber / cm -1 The peak near 1580 wavenumber / cm -1 The peak width ratio of the nearby spectral peaks is 1:0.5-0.95, and the peak height ratio is 1:1.05-1.

5.

6. A method for preparing a porous carbon material, the method comprising sequentially carbonizing and activating an organic carbon source, characterized in that: The carbonization is carried out in the presence of montmorillonite.

7. The preparation method according to claim 6, wherein: The specific surface area of ​​the montmorillonite is 50-1000m 2 / g, preferably 150-600m 2 / g.

8. The preparation method according to claim 7, wherein: The montmorillonite is an acid-treated montmorillonite, wherein the acid-treated montmorillonite raw material is contacted with an acid solution, wherein the liquid-to-solid ratio of the montmorillonite raw material to the acid solution is 5 to 50 mL / g, preferably 8 to 30 mL / g; + The concentration is 0.1 to 6 mol / L, preferably 0.5 to 3 mol / L.

9. The preparation method according to claim 8, wherein: The contacting temperature is 20 to 100° C., preferably 30 to 70° C.; the contacting time is 2 to 48 hours, preferably 5 to 30 hours.

10. The preparation method according to claim 8 or 9, wherein: The average particle diameter of the montmorillonite raw material is 0.1 to 20 μm, preferably 0.3 to 15 μm; the specific surface area of ​​the montmorillonite raw material is 20 to 300 m 2 / g preferably 20 to 250 m 2 / g.

11. The preparation method according to any one of claims 6 to 10, wherein: The carbonization temperature is 200-650° C., preferably 300-600° C., and the carbonization time is 40-500 minutes, preferably 50-200 minutes.

12. The preparation method according to any one of claims 6 to 11, wherein: The carbonization method includes firstly performing the carbonization at 300-550°C, preferably 450-520°C, for 10-100 min, preferably 20-60 min; and then performing the carbonization at 400-650°C, preferably 500-600°C, for 40-200 min, preferably 60-200 min.

13. The preparation method according to any one of claims 6 to 12, wherein: The mass ratio of the organic carbon source to montmorillonite is 100 to 1:1, preferably 50 to 3:

1.

14. The preparation method according to any one of claims 6 to 13, wherein: The weight ratio of the carbonized material to the activating agent used for activation is 1:0.2-10, preferably 1:1.5-3; the activation temperature is 600-1000°C, preferably 700-900°C; the activation time is 20-180 min, preferably 20-120 min; preferably, the activating agent is NaOH and / or KOH.

15. The porous carbon material obtained by the preparation method according to any one of claims 6 to 14.

16. Use of the porous carbon material according to any one of claims 1 to 5 and 15 in a supercapacitor, preferably as an active electrode material.

17. A supercapacitor, characterized in that: The supercapacitor uses the porous carbon material described in any one of claims 1 to 5 and 15 as an active electrode material.

18. The supercapacitor according to claim 17, wherein: The supercapacitor is an organic button-type supercapacitor. When the current density is 1 A / g, the mass specific capacitance is 25-45 F / g, preferably 35-45 F / g; when the current density increases to 15 A / g, the mass specific capacitance of the organic button-type supercapacitor is 20-40 F / g, preferably 30-39 F / g, and the specific capacitance retention rate after 100,000 charge and discharge cycles is 78-95%, preferably 85-95%.

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