Carbon material, method for producing the same, and method for using the same

Abstract

The application relates to a carbon material and a preparation method and an application method thereof, the preparation method comprising the following steps: mixing polyformaldehyde, a phenolic substance and an alkaline solution to perform a reaction, so as to obtain a polyhydroxy phenolic crosslinking agent; mixing an aromatic oil and biomass, and then adding the polyhydroxy phenolic crosslinking agent to perform a crosslinking condensation reaction, so as to obtain a condensed polycyclic polynuclear aromatic resin; and carbonizing the condensed polycyclic polynuclear aromatic resin, so as to obtain the carbon material, thereby providing a method for preparing a high-performance carbon material which can be used as an electrode material of a sodium ion battery by taking a petrochemical aromatic oil and biomass as raw materials, and oxygen-containing functional groups can be introduced into the obtained condensed polycyclic polynuclear aromatic resin, so that the metal ion storage capacity of the finally prepared condensed polycyclic polynuclear aromatic resin-based carbon material can be greatly improved, and the carbon material can be well applied in a metal ion battery.

Description

Technical Field

[0001] This application relates to the field of carbon materials technology, specifically to a carbon material and its preparation and application methods. Background Technology

[0002] With the development of the petrochemical industry, ethylene cracking and catalytic cracking processes have become increasingly important. These processes produce two aromatic-rich oils as byproducts: ethylene tar (accounting for approximately 15% of ethylene production capacity) and catalytic cracked diesel (accounting for approximately 30% of diesel production capacity). Industrially, ethylene tar is primarily used as fuel, which not only contributes to environmental problems such as the greenhouse effect and air pollution but also wastes its rich aromatic hydrocarbon resources. Catalytic diesel is mainly converted into light aromatics and benzene-toluene-xylene mixtures through hydrogenation processes to upgrade its utilization; however, these processes are energy-intensive and economically inefficient. Therefore, finding efficient and rational ways to convert ethylene tar and catalytic diesel into high-value-added materials is of great significance and practical value. Since both by-product oils are aromatic oils, characterized by their high carbon content and susceptibility to electrophilic substitution reactions, utilizing these two characteristics to transform them into carbon-rich macromolecular polymers (condensed polycyclic aromatic hydrocarbon resins) followed by carbonization to produce high-value-added carbon materials for electrodes is an efficient and effective pathway for utilizing these two aromatic oils. This not only effectively converts the aromatics in the by-product oils into high-value-added carbon materials but also improves the economic efficiency of the petroleum refining system and optimizes petroleum processing technology.

[0003] Generally, when carbon materials are used as anodes in batteries containing alkali metal ions (e.g., sodium ions) with slightly larger ionic radii, certain requirements are placed on the interlayer spacing and disorder of the carbon materials. However, ethylene tar and catalytic diesel oil are both aromatic hydrocarbon-rich oils. Although traditional crosslinking agents (e.g., terephthalic acid, divinylbenzene, trioxymethylene, benzaldehyde, and terephthalaldehyde) can transform them into condensed polycyclic aromatic hydrocarbon resin-based carbon materials, they exhibit soft carbon behavior similar to asphalt, i.e., low interlayer spacing and disorder, which is unfavorable for storing alkali metal ions with large ionic radii.

[0004] Therefore, how to improve the metal ion storage capacity of condensed polycyclic aromatic hydrocarbon resin-based carbon materials has become an urgent problem to be solved. Summary of the Invention

[0005] The purpose of this application is to provide a carbon material and its preparation and application methods to improve the metal ion storage capacity of condensed polycyclic aromatic hydrocarbon resin-based carbon materials.

[0006] This application provides a method for preparing a carbon material, which includes: mixing paraformaldehyde, phenolic substances and an alkaline solution and reacting them to obtain a polyhydroxyphenolic crosslinking agent; mixing aromatic oil with biomass and adding the polyhydroxyphenolic crosslinking agent to carry out a crosslinking condensation reaction to obtain a condensed polycyclic polynuclear aromatic resin; and carbonizing the condensed polycyclic polynuclear aromatic resin to obtain the carbon material.

[0007] The process involves mixing paraformaldehyde, phenolic substances, and an alkaline solution and reacting them to obtain a polyhydroxyphenolic crosslinking agent. This includes: dissolving paraformaldehyde and phenolic substances in an alkaline solution to form a mixed solution; stirring the mixed solution at a first predetermined temperature for a first predetermined time, followed by standing and separating for a second predetermined time to obtain the polyhydroxyphenolic crosslinking agent. The first predetermined temperature is 20–90°C, the first predetermined time is 3–48 h, and the second predetermined time is 6–24 h.

[0008] Among them, phenolic substances include one or more of phenol, catechol, hydroquinone, resorcinol, phloroglucinol, p-tert-butylphenol, p-tert-octylphenol, and p-methylphenol; the alkaline solution is an aqueous solution of any one or more combinations of sodium hydroxide, potassium hydroxide, and ammonia, and the mass concentration of the alkaline solution is 2% to 50%; the mass ratio of paraformaldehyde to phenolic substances is (30 to 55): (45 to 70); the mass ratio of paraformaldehyde to alkali in the alkaline solution is (1 to 2.5): (0.5 to 1.5).

[0009] Among them, aromatic oil includes one or more of catalytic diesel, ethylene tar, ethylene tar residues and light fractions of ethylene tar; biomass includes one or more of hydrolyzed tannic acid, condensed tannic acid, cellulose, starch and lignin.

[0010] The mass ratio of aromatic oil, biomass and polyhydroxyphenol crosslinking agent is (45-55):(5-20):(25-50).

[0011] The process involves mixing aromatic oil with biomass and then adding a polyhydroxyphenolic crosslinking agent to perform a crosslinking condensation reaction to obtain a condensed polycyclic and polynuclear aromatic resin. The process includes: mixing aromatic oil with biomass and then adding a polyhydroxyphenolic crosslinking agent, stirring the mixture at a second predetermined temperature for a third predetermined time, and obtaining the condensed polycyclic and polynuclear aromatic resin. The second predetermined temperature is 120–260°C, and the third predetermined time is 2–10 h.

[0012] The process of carbonizing condensed polycyclic aromatic hydrocarbon resin to obtain carbon materials includes: calcining condensed polycyclic aromatic hydrocarbon resin to obtain carbon materials.

[0013] The calcination heating rate is 1–5℃ / min; the final calcination temperature is 800–1600℃; the calcination holding time is 1–10h; and the calcination is carried out under a protective gas atmosphere.

[0014] This application also provides a carbon material, which is prepared by any of the above-described methods for preparing carbon materials.

[0015] This application also provides a method for using carbon materials, which includes: using the above-mentioned carbon materials to make a metal-ion battery negative electrode.

[0016] The carbon material, its preparation method, and its application method provided in this application involve reacting a mixture of paraformaldehyde, phenolic substances, and an alkaline solution to obtain a polyhydroxyphenolic crosslinking agent. Then, a mixture of aromatic oil and biomass is added to the polyhydroxyphenolic crosslinking agent for a crosslinking condensation reaction, yielding a condensed polycyclic aromatic hydrocarbon resin. This resin is then carbonized to obtain the carbon material. This provides a method for preparing high-performance carbon materials suitable as electrode materials for sodium-ion batteries using petrochemical aromatic oil and biomass as raw materials. Furthermore, this method utilizes highly polar functional groups... Biomass is introduced into petrochemical aromatic oil, and the petrochemical aromatic oil is linked with biomass rich in polar functional groups through a polyhydroxyphenol crosslinking agent. This allows the introduction of polar functional groups (e.g., oxygen-containing functional groups) into the resulting condensed polycyclic and polynuclear aromatic resin, thereby controlling the structural properties of the final condensed polycyclic and polynuclear aromatic resin-based carbon material. This significantly improves the metal ion storage capacity of the final condensed polycyclic and polynuclear aromatic resin-based carbon material, making it suitable for storing alkali metal ions with large ionic radii, and enabling its good application in metal-ion batteries. Attached Figure Description

[0017] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0018] Figure 1 This is a schematic flowchart of the carbon material preparation method provided in the embodiments of this application. Detailed Implementation

[0019] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are for illustrative purposes only and do not limit the scope of the application. Similarly, the following embodiments are only some, not all, embodiments of the present application, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present application.

[0020] In the following description of this application, "some embodiments" are referred to, which describe a subset of all possible embodiments. However, it is understood that "some embodiments" may be the same subset or different subset of all possible embodiments, and may be combined with each other without conflict.

[0021] In the following description of this application, the terms "first, second, third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. In the event of any conflict, this specification shall prevail. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0023] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0024] The following detailed description is based on specific embodiments. It should be noted that the sequence numbers of the following embodiments are not intended to limit the preferred order of the embodiments.

[0025] Please see Figure 1 , Figure 1 This is a schematic flowchart of the carbon material preparation method provided in the embodiments of this application. The specific process of the carbon material preparation method can be as follows:

[0026] Step S11. Paraformaldehyde, phenolic substances and alkaline solution are mixed and reacted to obtain a polyhydroxyphenolic crosslinking agent.

[0027] In this embodiment, hydroxymethyl groups are attached to phenolic substances by paraformaldehyde, so that the phenolic substances have multiple cross-linkable active groups, thus obtaining a polyhydroxyphenolic cross-linking agent. The obtained polyhydroxyphenolic cross-linking agent can be specifically a polyol, which can then act on aromatic oil molecules such as ethylene tar and catalytic diesel to synthesize condensed polycyclic and polynuclear aromatic resins with high oxygen-containing functional group content.

[0028] Among them, phenolic substances may include one or more of phenol, catechol, hydroquinone, resorcinol, phloroglucinol, p-tert-butylphenol, p-tert-octylphenol, and p-methylphenol. For example, it may specifically be phenol, catechol, phloroglucinol, or p-tert-octylphenol.

[0029] The alkaline solution can be an aqueous solution of any one or more combinations of sodium hydroxide, potassium hydroxide, and ammonia, specifically, an aqueous solution of ammonia, sodium hydroxide, or potassium hydroxide. Furthermore, the mass concentration of the alkaline solution can be from 2% to 50%, specifically 2%, 5%, 12%, 20%, 30%, or 40%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable. In some examples, the alkaline solution can specifically be a 2% sodium hydroxide aqueous solution, or a 10% potassium hydroxide aqueous solution, or a 15% sodium hydroxide aqueous solution, or a 20% potassium hydroxide aqueous solution, or a 30% ammonia aqueous solution.

[0030] Furthermore, it should be noted that in the embodiments of this application, by using paraformaldehyde to convert phenolic substances into polyhydroxyphenolic crosslinking agents under alkaline conditions, on the one hand, the polyhydroxyphenolic crosslinking agent contains more oxygen-containing functional groups than traditional crosslinking agents (such as terephthalic acid, divinylbenzene, trioxymethylene, benzaldehyde, and terephthalic acid), and on the other hand, the polyhydroxyphenolic crosslinking agent, due to its rich oxygen-containing functional groups, is beneficial to promoting deep crosslinking between macromolecular resins in the subsequent carbonization process of the obtained condensed polycyclic polynuclear aromatic resin to obtain carbon materials.

[0031] In some embodiments, in step S11, the mass ratio of paraformaldehyde to phenolic substances can be (30-55):(45-70), specifically 30:70, 38:62, 43:57, 55:45, or 47:53, but is not limited to the listed values; other unlisted values ​​within the range are also applicable. Thus, by controlling the mass ratio of paraformaldehyde to phenolic substances in step S11 within a specific range, it is possible to ensure the formation of a polyhydroxy structure between paraformaldehyde and phenolic substances, thereby effectively improving the crosslinking effect of the crosslinking agent (i.e., the polyhydroxyphenolic crosslinking agent) obtained in step S11. Furthermore, by controlling the amount of paraformaldehyde used in step S11, excessive condensation reactions between the crosslinking agents obtained in step S11 can be prevented to avoid the formation of condensation polymers, thereby ensuring the crosslinking effect of the crosslinking agent obtained in step S11.

[0032] In some embodiments, in step S11 above, the mass ratio of paraformaldehyde used to alkali in the alkaline solution can be (1-2.5):(0.5-1.5), for example, specifically 0.8:1, 2:1, 3.2:1 or 4.0:1, but not limited to the listed values, other unlisted values ​​within the range are also applicable.

[0033] In some embodiments, step S11 may specifically include:

[0034] Step S111. Dissolve paraformaldehyde and phenolic substances in an alkaline solution to form a mixed solution;

[0035] Step S112. The mixed solution is stirred at a first predetermined temperature for a first predetermined time, and then allowed to stand for a second predetermined time to obtain a polyhydroxyphenol crosslinking agent.

[0036] Specifically, after dissolving paraformaldehyde and phenolic substances in an alkaline solution to form a mixed solution, the mixed solution can be stirred at a first predetermined temperature for a first predetermined time, and then allowed to stand for a second predetermined time to obtain a polyhydroxyphenolic crosslinking agent.

[0037] The first predetermined temperature can be between 20 and 90°C, specifically 25°C or 60°C, but is not limited to the listed values; other unlisted values ​​within this range are also applicable. The first predetermined time can be between 3 and 48 hours, specifically 2 hours, 5 hours, 15 hours, 20 hours, 24 hours, 35 hours, or 48 hours, but is not limited to the listed values; other unlisted values ​​within this range are also applicable. Thus, by controlling both the stirring reaction time and temperature within a specific range, sufficient time can be provided to ensure the complete conversion of phenolic substances into polyhydroxyphenolic crosslinking agents, while also ensuring thorough mixing of the reaction raw materials.

[0038] The second predetermined time can be 6 to 24 hours, specifically 6 hours, 12 hours, 24 hours, or 8 hours, but is not limited to the listed values; other unlisted values ​​within the range are also applicable. Thus, by controlling the settling time within a specific range, it is possible to promote the complete protonation of the metal salt (e.g., sodium salt) in the reaction system and to ensure the complete extraction of the crosslinking agent.

[0039] Furthermore, in specific implementation, paraformaldehyde and phenolic substances can be mixed in a certain mass ratio, and then an alkaline solution can be added in a certain mass ratio of alkaline solution to paraformaldehyde. The mixture is then stirred and reacted at a set temperature for a certain time, and the resulting product is purified and separated to obtain a polyhydroxyphenolic crosslinking agent.

[0040] Step S12. After mixing the aromatic oil with biomass, add a polyhydroxyphenol crosslinking agent to carry out a crosslinking condensation reaction to obtain a condensed polycyclic polynuclear aromatic resin.

[0041] The aromatic oil may include at least one of petrochemical aromatic oils such as catalytic diesel, ethylene tar, ethylene tar residues (e.g., ethylene tar-coated asphalt residues), and ethylene tar light fractions. Biomass may include at least one of biomass rich in polar functional groups (e.g., hydroxyl, ether, ester, carboxyl, etc.) such as hydrolyzed tannic acid, condensed tannic acid, cellulose, starch, and lignin.

[0042] In this embodiment, by using low-cost petrochemical aromatic oil and biomass as raw materials, and employing the polyhydroxyphenolic crosslinking agent obtained after step S11, the raw materials are transformed into condensed polycyclic and polynuclear aromatic resins. On the one hand, the raw materials are low-cost, and on the other hand, biomass introduces more oxygen-containing functional groups into the condensed polycyclic and polynuclear aromatic resins, which can control the content of oxygen-containing functional groups in the condensed polycyclic and polynuclear resins, thereby effectively improving the electrochemical performance of the finally obtained condensed polycyclic and polynuclear aromatic resin-based carbon material.

[0043] In some embodiments, in step S12 above, the mass ratio of the aromatic oil, biomass, and polyhydroxyphenolic crosslinking agent can be (45-55):(5-20):(25-50), for example, specifically 45:5:50, 45:10:45, 50:5:45, or 55:15:30, but not limited to the listed values; other unlisted values ​​within the range are also applicable. Thus, by controlling the proportions of the aromatic oil, biomass, and crosslinking agent in step S12 within a specific range, the amount of oxygen-containing functional groups introduced into the obtained condensed polycyclic aromatic hydrocarbon resin can be controlled, thereby enabling the controllable preparation of condensed polycyclic aromatic hydrocarbon resins with different oxygen-containing functional group contents, and thus achieving structural regulation of condensed polycyclic aromatic hydrocarbon resin-based carbon materials.

[0044] In some embodiments, in step S12 above, the crosslinking condensation reaction time can be 2 to 10 hours, for example, specifically 1 to 2 hours. Exemplarily, in step S12 above, the crosslinking condensation reaction time can be 2 hours, 2.5 hours, 3 hours, 5 hours, 7.5 hours, or 10 hours, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0045] In some embodiments, in step S12 above, the temperature of the crosslinking condensation reaction can be 120–260°C, for example, specifically 170–240°C. Exemplarily, in step S12 above, the temperature of the crosslinking condensation reaction can specifically be 120°C, 135°C, 145°C, 170°C, 200°C, 220°C, 245°C, or 260°C, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0046] In some specific embodiments, step S12 may specifically include: mixing aromatic oil with biomass and then adding a polyhydroxyphenol crosslinking agent, stirring and reacting at a second predetermined temperature for a third predetermined time to obtain a condensed polycyclic aromatic hydrocarbon resin, wherein the second predetermined temperature is 120-260°C and the third predetermined time is 2-10h.

[0047] Specifically, aromatic oil and biomass can be mixed in a certain mass ratio, and then a crosslinking agent (i.e., the polyhydroxyphenolic crosslinking agent obtained after step S12 above) and a catalyst (e.g., p-toluenesulfonic acid) can be added to carry out a crosslinking condensation reaction to prepare a condensed polycyclic aromatic hydrocarbon resin. During the crosslinking condensation reaction, the crosslinking agent connects the aromatic oil and biomass to each other, thereby introducing polar functional groups into the condensed polycyclic aromatic hydrocarbon resin through the polar functional groups on the molecular structure of biomass and crosslinking agent, so that it can undergo deep crosslinking in the subsequent resin carbonization process to regulate the material structure properties such as interlayer spacing, disorder, and specific surface area of ​​carbon materials.

[0048] Furthermore, in practice, after the cross-linking condensation reaction is completed, the obtained product can be dissolved, precipitated, and dried to remove residual impurities on the resin, thereby obtaining the final product (i.e., condensed polycyclic aromatic hydrocarbon resin).

[0049] Step S13: Carbonize the condensed polycyclic aromatic hydrocarbon resin to obtain carbon material.

[0050] In this embodiment, the carbon material obtained after step S13 is a condensed polycyclic aromatic hydrocarbon resin-based carbon material, which can be used as an electrode material for sodium-ion batteries. Furthermore, compared to existing resin-based carbon materials, the carbon material obtained after step S13 has a larger interlayer spacing and greater disorder, thus effectively improving the overall electrochemical performance of sodium-ion batteries when used as a negative electrode material. For example, it can enable the reversible capacity of the sodium-ion battery to reach 260 mAh / g at a current density of 100 mA / g.

[0051] It is understandable that, on the one hand, the presence of oxygen-containing functional groups in the condensed polycyclic aromatic hydrocarbon resin obtained after step S12 is beneficial for forming carbon materials with larger interlayer spacing and disorder in step S13; on the other hand, the resin-based carbon materials prepared by cross-linking and condensing biomass and aromatic oil together with polyhydroxyphenolic cross-linking agents effectively improve the overall electrochemical performance of sodium-ion batteries when used as a negative electrode material.

[0052] In some embodiments, the condensed polycyclic aromatic hydrocarbon resin can be carbonized at high temperature to obtain a carbon material. Specifically, after obtaining the condensed polycyclic aromatic hydrocarbon resin, the condensed polycyclic aromatic hydrocarbon resin can be calcined to obtain a carbon material.

[0053] The heating rate for calcination can be 1–5 °C / min, for example, specifically 2–5 °C / min. For example, the heating rate for calcination can be 1 °C / min, 1.5 °C / min, 2.5 °C / min, 4 °C / min, or 5 °C / min, but is not limited to the listed values; other unlisted values ​​within the range are also applicable.

[0054] The final calcination temperature can be between 800 and 1600°C, specifically between 1000 and 1500°C. For example, the final calcination temperature can be 800°C, 900°C, 1000°C, 1100°C, 1200°C, 1300°C, 1400°C, or 1600°C, but is not limited to the listed values; other unlisted values ​​within the range are also applicable. Thus, by controlling the calcination temperature within a specific range, the condensed polycyclic aromatic hydrocarbon resin can be completely converted into a carbon material.

[0055] The holding time for calcination can be 1 to 10 hours, for example, 2 to 6 hours. For example, the holding time for calcination can be 1 hour, 1.5 hours, 3 hours, 5 hours, 7 hours, 8 hours or 10 hours, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0056] The calcination can be carried out under a protective gas atmosphere, which can be argon or nitrogen.

[0057] In some specific embodiments, the condensed polycyclic aromatic hydrocarbon resin obtained after step S12 can be heated to a specific temperature at a certain heating rate for carbonization treatment to obtain condensed polycyclic aromatic hydrocarbon resin-based carbon material. The electrochemical performance of the obtained condensed polycyclic aromatic hydrocarbon resin-based carbon material is significantly improved due to the introduction of oxygen-containing functional groups.

[0058] Furthermore, in specific implementation, the condensed polycyclic aromatic hydrocarbon resin obtained after step S21 can be calcined at a rate of 1-5℃ / min to 800-1600℃ and held for 1-10h under an argon atmosphere to obtain a high-performance carbon material that can be used as an electrode material for sodium-ion batteries.

[0059] It should be noted that among the existing technologies for preparing carbon materials using petrochemical aromatic oils:

[0060] Chinese patent document (CN119050351A) discloses a method for converting low softening point asphalt into high softening point asphalt using crosslinking agents such as terephthalaldehyde, terephthalaldehyde, benzaldehyde, trioxymethylene, and p-methylbenzaldehyde. Pre-oxidized asphalt balls are then obtained by plasma oxidation, and finally asphalt-based hard carbon material is obtained by carbonization. This asphalt-based hard carbon material can be used as a negative electrode material for lithium-ion / sodium-ion batteries. When this asphalt-based hard carbon material is used as a negative electrode material for sodium-ion batteries, the reversible capacity of the sodium-ion battery can reach 310 mAh / g.

[0061] Chinese patent document (CN118479452A) discloses a method for preparing asphalt-based hypercrosslinked polymers using coal tar pitch, petroleum pitch, and shale pitch as raw materials, and using dimethoxymethane and p-phenylenedimethyl dimethyl ether as crosslinking agents under the action of concentrated sulfuric acid and dichloromethane. The polymers are then carbonized to obtain hard carbon materials for sodium-ion battery anodes. This patent provides a simple and efficient preparation method for asphalt-derived hard carbon materials for sodium-ion batteries.

[0062] Chinese patent document (CN118419903A) discloses a method for preparing a hard carbon material for sodium-ion anodes with abundant micropores and sodium storage sites by using coal / biomass / asphalt as raw materials, preparing a homogeneous mixture of coal and biomass through ball milling, and then subjecting it to blistering and pre-carbonization treatment before hydrothermal reaction with asphalt. This provides a simple and easily mass-producible method for preparing high-capacity sodium-ion anode materials.

[0063] Chinese patent document (CN118324117A) discloses a method for preparing carbon materials for sodium ion anodes by hydrothermal reaction and drying of petroleum asphalt and sucrose.

[0064] Chinese patent document (CN117902565A) discloses a method of crosslinking asphalt and resin (including phenolic resin, epoxy resin, furanyl ether, benzoxazine resin) under the action of a crosslinking agent (acid anhydride) to effectively control the molecular structure of carbon precursors, thereby regulating the disorder, interlayer spacing and pore structure of carbonized products.

[0065] Chinese patent document (CN116395667B) discloses a method for obtaining doped asphalt powder by pre-treating it in ball milling tanks with different atmospheres such as oxygen, nitrogen, ammonia, phosphine, boron trichloride, and hydrogen sulfide, and then obtaining hard carbon material by high-temperature carbonization. This patent provides a method for controlling the doping elements and doping amount in asphalt by adjusting the plasma ball milling parameters to control the structural properties of asphalt.

[0066] The aforementioned patent documents propose methods for preparing carbon materials for sodium-ion battery anodes using petrochemical-rich aromatic hydrocarbons. These methods include using traditional crosslinking agents to increase the softening point of asphalt, pre-oxidation treatment to dope heteroatoms (O, N, P, etc.) into the asphalt structure, hyper-crosslinking to crosslink asphalt particles, and combining biomass and hydrothermal treatment methods to improve the pore structure and sodium storage sites of the final asphalt-based carbon material. While these methods provide inexpensive asphalt and performance improvement methods for preparing carbon materials for sodium-ion battery anodes, none of them involve using inexpensive and readily available petrochemical-rich aromatic hydrocarbon oils (ethylene tar and catalytic diesel) combined with biomass, crosslinking and condensing them under the action of phenolic crosslinking agents to obtain condensed polycyclic and polynuclear aromatic hydrocarbon resins, and then carbonizing them to obtain carbon materials for sodium-ion anodes.

[0067] Therefore, in response to the current situation of continuously increasing production capacity of aromatic hydrocarbon-rich oils but difficult utilization, and the shortcomings of traditional petroleum-based resins in producing carbon materials with poor electrochemical performance, this application provides a method for preparing high-performance carbon materials that can be used as electrode materials for sodium-ion batteries using petrochemical aromatic hydrocarbon oils and biomass as raw materials. Furthermore, compared to existing technologies for preparing carbon materials using petrochemical aromatic hydrocarbon oils, the method provided in this application for preparing high-performance carbon materials that can be used as electrode materials for sodium-ion batteries can, on the one hand, efficiently and environmentally convert aromatic hydrocarbon oils and biomass raw materials into high-value-added products (i.e., high-performance carbon materials); on the other hand, it can introduce oxygen-containing functional groups into traditional petroleum-based resins and achieve control over the content of oxygen-containing functional groups, thereby effectively improving the electrochemical performance of carbon materials, such as ion storage capacity, conductivity, and performance stability.

[0068] Furthermore, for ease of understanding, this application will be further described in detail below through seven specific embodiments (i.e., Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4, Embodiment 5, Embodiment 6 and Embodiment 7), with Comparative Example 1 and Comparative Example 2 as comparisons.

[0069] Example 1

[0070] In Example 1, the specific process for preparing the carbon material can be as follows:

[0071] Step S21. Weigh 10g of paraformaldehyde and 24g of phenol, dissolve them in a 2% sodium hydroxide solution, and the mass ratio of paraformaldehyde to the alkali (i.e., sodium hydroxide) in the alkaline solution (i.e., the 2% sodium hydroxide solution) is 0.8. After the paraformaldehyde and phenol are completely dissolved, stir and react at 20°C for 24h, and then let stand for 12h to obtain a polyhydroxyphenol crosslinking agent.

[0072] Step S22. Weigh 10g of catalytic diesel oil, 4.44g of hydrolyzed tannic acid and 4.81g of the polyhydroxyphenol crosslinking agent obtained in step S21 above, and stir the mixture at 160℃ for 8h to obtain condensed polycyclic aromatic hydrocarbon resin.

[0073] Step S23. Weigh 2g of the condensed polycyclic aromatic hydrocarbon resin obtained in step S22 above, and calcine it at 1200℃ at a rate of 1℃ / min under an argon atmosphere and keep it at that temperature for 2h to obtain a high-performance carbon material that can be used as an electrode material for sodium-ion batteries. The carbon material is then cooled and dried for later use.

[0074] Example 2

[0075] In Example 2, the specific process for preparing the carbon material can be as follows:

[0076] Step S31. Weigh 10g of paraformaldehyde and 17.24g of catechol, dissolve them in a 10% potassium hydroxide solution, and the mass ratio of paraformaldehyde to the alkali (i.e., potassium hydroxide) in the alkaline solution (i.e., the 10% potassium hydroxide solution) is 2. After the paraformaldehyde and catechol are completely dissolved, stir and react at 35°C for 30h, and then let stand for 8h to separate and obtain a polyhydroxyphenol crosslinking agent.

[0077] Step S32. Weigh 10g of ethylene tar coated asphalt residue, 2.86g of condensed tannin and 5.14g of the polyhydroxyphenol crosslinking agent obtained in step S31 above, and stir and react at 180℃ for 5h to obtain condensed polycyclic aromatic hydrocarbon resin.

[0078] Step S33. Weigh 2g of the condensed polycyclic aromatic hydrocarbon resin obtained in step S32 above, and calcine it at 1000℃ at a rate of 2℃ / min under an argon atmosphere and keep it at that temperature for 3h to obtain a high-performance carbon material that can be used as an electrode material for sodium-ion batteries. The carbon material is then cooled and dried for later use.

[0079] Example 3

[0080] In Example 3, the specific process for preparing the carbon material can be as follows:

[0081] Step S41. Weigh 10g of paraformaldehyde and 14.29g of phloroglucinol, dissolve them in a 15% sodium hydroxide solution, and the mass ratio of paraformaldehyde to the alkali (i.e., sodium hydroxide) in the alkaline solution (i.e., the 15% sodium hydroxide solution) is 3.2. After the paraformaldehyde and phloroglucinol are completely dissolved, stir and react at 45°C for 15h, and then let stand for 10h to obtain a polyhydroxyphenol crosslinking agent.

[0082] Step S42. Weigh 10g of ethylene tar light distillate oil, 1.67g of lignin and 5.83g of the polyhydroxyphenol crosslinking agent obtained in step S41 above, and stir the reaction at 200℃ for 10h to obtain condensed polycyclic polynuclear aromatic resin.

[0083] Step S43. Weigh 2g of the condensed polycyclic aromatic hydrocarbon resin obtained in step S42 above, and calcine it at 1400℃ at a rate of 5℃ / min under an argon atmosphere and keep it at that temperature for 3h to obtain a high-performance carbon material that can be used as an electrode material for sodium-ion batteries. The carbon material is then cooled and dried for later use.

[0084] Example 4

[0085] In Example 4, the specific process for preparing the carbon material can be as follows:

[0086] Step S51. Weigh 10g of paraformaldehyde and 11.11g of p-tert-octylphenol, dissolve them in a 20% potassium hydroxide solution, and the mass ratio of paraformaldehyde to the alkali (i.e., potassium hydroxide) in the alkaline solution (i.e., the 20% potassium hydroxide solution) is 4.0. After the paraformaldehyde and p-tert-octylphenol are completely dissolved, stir the reaction at 60°C for 6 hours, and then let it stand for 24 hours to separate and obtain a polyhydroxyphenol crosslinking agent.

[0087] Step S52. Weigh 10g of ethylene tar, 1.25g of lignin and 7.50g of the polyhydroxyphenol crosslinking agent obtained in step S52 above, and stir the mixture at 230℃ for 3h to obtain a condensed polycyclic aromatic hydrocarbon resin.

[0088] Step S53. Weigh 2g of the condensed polycyclic aromatic hydrocarbon resin obtained in step S52 above, and calcine it at 1600℃ at a rate of 3℃ / min under an argon atmosphere and keep it at that temperature for 2h to obtain a high-performance carbon material that can be used as an electrode material for sodium-ion batteries. The carbon material is then cooled and dried for later use.

[0089] Example 5

[0090] The preparation method of the carbon material provided in Example 5 is basically the same as that provided in Example 1, the only difference being that: in ensuring OH... - With the total amount remaining the same, the sodium hydroxide solution was replaced with an ammonia solution.

[0091] Example 6

[0092] The preparation method of the carbon material provided in Example 6 is basically the same as that provided in Example 2. The only difference is that the crosslinking condensation reaction time is changed from 5 hours to 12 hours.

[0093] Example 7

[0094] The preparation method of the carbon material provided in Example 7 is basically the same as that provided in Example 4. The only difference is that the calcination temperature is changed from 1600℃ to 800℃.

[0095] Comparative Example 1

[0096] The preparation method of the carbon material provided in Comparative Example 1 is basically the same as that provided in Example 1. The only difference is that the polyhydroxyphenol crosslinking agent in step S22 is replaced with terephthalic acid.

[0097] Comparative Example 2

[0098] The preparation method of the carbon material provided in Comparative Example 2 is basically the same as that provided in Example 1. The only difference is that the weighing of 10g of catalytic diesel, 4.44g of hydrolyzed tannic acid and 4.81g of the polyhydroxyphenol crosslinking agent obtained in step S21 in step S22 is changed to weighing only 10g of catalytic diesel and 4.81g of the polyhydroxyphenol crosslinking agent obtained in step S21. That is, biomass was not used in Comparative Example 2.

[0099] Specifically, by conducting electrochemical performance tests on the carbon materials obtained in Examples 1, 2, 3, 4, 5, 6, 7, Comparative Example 1, and Comparative Example 2, the electrochemical performance test results of each carbon material are shown in Table 1 below.

[0100] The process of testing the electrochemical performance of carbon materials may include: mixing carbon materials, conductive agents, and binders in a mass ratio of 8:1:1, adding N-methylpyrrolidone (NMP) as a solvent, stirring evenly, and then uniformly coating the mixture onto aluminum foil. The mixture is then dried in a vacuum oven for 12 hours to obtain carbon-coated aluminum foil. The carbon-coated aluminum foil is then cut into electrodes of the required diameter. The obtained electrodes are then used as electrodes, Whatman glass fiber is used as a separator, and a 1 mol / L NaPF6 solution is used as the electrolyte to assemble a battery. Furthermore, for the assembled battery, the reversible capacity and plateau capacity are tested at different current densities within a test voltage range of 0.01–2.0 V. The test results are shown in Table 1 below.

[0101] Table 1

[0102]

[0103] As can be seen from the test results in Table 1, when the carbon materials prepared in Examples 1 to 7 are used as electrode materials for sodium-ion batteries, they can effectively improve the overall electrochemical performance of sodium-ion batteries. For example, the reversible capacity of sodium-ion batteries at different current densities can be significantly improved.

[0104] Comparing Example 1 with Comparative Example 1, it can be seen that polyhydroxyphenolic crosslinking agents are more conducive to forming carbon materials with high electrochemical performance in the subsequent carbonization process of the obtained condensed polycyclic polynuclear aromatic resin to obtain carbon materials than traditional crosslinking agents.

[0105] Comparing Example 1 and Comparative Example 2, it can be seen that the introduction of biomass is beneficial to the formation of carbon materials with high electrochemical performance in the subsequent carbonization process of the obtained condensed polycyclic aromatic hydrocarbon resin to obtain carbon materials.

[0106] As can be seen from the above, the method for preparing carbon materials provided in this embodiment involves reacting a mixture of paraformaldehyde, phenolic substances, and an alkaline solution to obtain a polyhydroxyphenolic crosslinking agent. Then, a mixture of aromatic oil and biomass is added to the polyhydroxyphenolic crosslinking agent for a crosslinking condensation reaction, yielding a condensed polycyclic aromatic hydrocarbon resin. Finally, the condensed polycyclic aromatic hydrocarbon resin is carbonized to obtain the carbon material. This provides a method for preparing high-performance carbon materials that can be used as electrode materials for sodium-ion batteries using petrochemical aromatic oil and biomass as raw materials. Furthermore, this method utilizes highly polar functional groups... Biomass is introduced into petrochemical aromatic oil, and the petrochemical aromatic oil is linked with biomass rich in polar functional groups through a polyhydroxyphenol crosslinking agent. This allows the introduction of polar functional groups (e.g., oxygen-containing functional groups) into the resulting condensed polycyclic and polynuclear aromatic resin, thereby controlling the structural properties of the final condensed polycyclic and polynuclear aromatic resin-based carbon material. This significantly improves the metal ion storage capacity of the final condensed polycyclic and polynuclear aromatic resin-based carbon material, making it suitable for storing alkali metal ions with large ionic radii, and enabling its good application in metal-ion batteries.

[0107] To better implement the carbon material preparation method provided in the embodiments of this application, the embodiments of this application also provide a carbon material, which is prepared by the carbon material preparation method provided in any of the above embodiments.

[0108] Specifically, this carbon material exhibits good electrode activity and can be used as an electrode material for sodium-ion batteries.

[0109] Furthermore, it should be noted that the carbon materials in this embodiment are prepared using the carbon material preparation method provided in any of the above embodiments, and therefore have all the same beneficial effects, which will not be repeated here.

[0110] Based on the carbon materials described in the above embodiments, this embodiment will further describe the application methods of carbon materials.

[0111] The carbon material application method provided in this application embodiment can be applied to the fabrication of battery electrodes. The specific process of this carbon material application method is as follows:

[0112] Carbon materials are used to make the negative electrode of a metal-ion battery.

[0113] Specifically, the carbon material provided in any of the above embodiments of this application can be used to fabricate the negative electrode of a metal-ion battery. The metal-ion battery can specifically be a sodium-ion battery, a lithium-ion battery, or a potassium-ion battery.

[0114] Furthermore, in specific implementation, the carbon material provided in any of the above embodiments can be mixed with a conductive agent and a binder, and a solvent can be added to obtain a slurry. The slurry is then coated onto a substrate and dried to obtain an electrode sheet. Specifically, the conductive agent can be a super p conductive agent (i.e., small-particle conductive carbon black). The binder can be PVDF (i.e., polyvinylidene fluoride). The solvent can be NMP (i.e., N-methylpyrrolidone). The substrate can be copper foil or aluminum foil.

[0115] For example, the carbon material, conductive agent and binder provided in any of the above embodiments can be mixed in a mass ratio of 8:1:1 and a solvent can be added to obtain a slurry. The slurry is then uniformly coated on the substrate and dried in a vacuum oven for 12 hours to obtain a carbon-coated substrate. The carbon-coated substrate is then cut into electrode sheets of the required diameter to obtain the negative electrode of a metal-ion battery.

[0116] In this embodiment, by using the carbon material provided in any of the above embodiments to prepare the metal-ion battery anode, the storage capacity of the metal-ion battery anode for metal ions (especially alkali metal ions with large ionic radii) can be effectively improved, thereby enhancing the electrochemical performance of the metal-ion battery.

[0117] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0118] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a carbon material, characterized in that, include: Paraformaldehyde, phenolic substances, and an alkaline solution are mixed and reacted to obtain a polyhydroxyphenolic crosslinking agent; After mixing aromatic oil with biomass, the polyhydroxyphenolic crosslinking agent is added to carry out a crosslinking condensation reaction to obtain a condensed polycyclic polynuclear aromatic resin. The condensed polycyclic aromatic hydrocarbon resin is carbonized to obtain a carbon material. The aromatic oil includes one or more of catalytic diesel, ethylene tar, ethylene tar residues, and light fractions of ethylene tar; the biomass includes one or more of hydrolyzed tannic acid, condensed tannic acid, cellulose, starch, and lignin.

2. The preparation method according to claim 1, characterized in that, The process of mixing paraformaldehyde, phenolic substances, and an alkaline solution and then reacting them to obtain a polyhydroxyphenolic crosslinking agent includes: Paraformaldehyde and phenolic substances are dissolved in an alkaline solution to form a mixed solution; The mixed solution is stirred at a first predetermined temperature for a first predetermined time, and then allowed to stand for a second predetermined time to obtain a polyhydroxyphenol crosslinking agent. The first predetermined temperature is 20~90℃, the first predetermined time is 3~48h, and the second predetermined time is 6~24h.

3. The preparation method according to claim 1, characterized in that, The phenolic substances include one or more of phenol, catechol, hydroquinone, resorcinol, phloroglucinol, p-tert-butylphenol, p-tert-octylphenol, and p-methylphenol; the alkaline solution is an aqueous solution of any one or more combinations of sodium hydroxide, potassium hydroxide, and ammonia, and the mass concentration of the alkaline solution is 2% to 50%; the mass ratio of paraformaldehyde to the phenolic substances is (30 to 55): (45 to 70); the mass ratio of paraformaldehyde to the alkali in the alkaline solution is (1 to 2.5): (0.5 to 1.5).

4. The preparation method according to claim 1, characterized in that, The mass ratio of the aromatic oil, the biomass, and the polyhydroxyphenolic crosslinking agent is (45~55):(5~20):(25~50).

5. The preparation method according to claim 1, characterized in that, The process involves mixing aromatic oil with biomass and then adding the polyhydroxyphenolic crosslinking agent to undergo a crosslinking condensation reaction to obtain a condensed polycyclic polynuclear aromatic resin, comprising: After mixing aromatic oil with biomass, the polyhydroxyphenol crosslinking agent is added, and the mixture is stirred at a second predetermined temperature for a third predetermined time to obtain a condensed polycyclic aromatic hydrocarbon resin. The second predetermined temperature is 120~260℃, and the third predetermined time is 2~10h.

6. The preparation method according to claim 1, characterized in that, The carbonization of the condensed polycyclic aromatic hydrocarbon resin to obtain a carbon material includes: The condensed polycyclic aromatic hydrocarbon resin was calcined to obtain a carbon material.

7. The preparation method according to claim 6, characterized in that, The heating rate of the calcination is 1~5℃ / min; the final temperature of the calcination is 800~1600℃; the holding time of the calcination is 1~10h; and the calcination is carried out in a protective gas atmosphere.

8. A carbon material, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.

9. A method for applying carbon materials, characterized in that, include: The carbon material described in claim 8 is used to fabricate the negative electrode of a metal-ion battery.

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