Preparation method of efficient activated carbon cloth based on carbon fibers
By synchronously modifying carbon fibers and activated carbon precursors during thermal cracking and using surfactant coupling agent to prepare high-efficiency activated carbon cloth, the problem of insufficient conductivity of activated carbon is solved, and activated carbon cloth with high conductivity and porous structure is achieved, which expands its application range.
Patent Information
- Application Number
- CN202510558516.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-29
- Publication Date
- 2025-08-08
AI Technical Summary
Inadequate conductivity of activated carbon limits its application in high power density environments, and existing modification methods use adhesives to reduce conductivity or lead to insufficient bonding strength.
The carbon fiber and activated carbon precursor are used as the binding agent to synchronously modify the carbon fiber and the activated carbon precursor, and the preparation of highly conductive and porous activated carbon is achieved simultaneously during the thermal cracking process. The use of adhesives is avoided and the carbon fiber and activated carbon are linked through the oxygen-containing functional groups of the surfactant.
The prepared activated carbon cloth not only maintains a high specific surface area and porous structure, but also greatly improves the conductivity and has good flexibility. It is suitable for supercapacitors, wires and cables, new energy batteries and other fields.
Smart Images
Figure CN120443459A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of functional materials, and in particular to a high-efficiency activated carbon cloth based on carbon fibers and a preparation method thereof. Background Art
[0002] Activated carbon is a carbon material with highly developed pores and is widely used in the fields of food, environment, chemical industry, medicine, electronics, etc. The large number of micropores and mesoporous structures inside it, as well as the stable source of carbon materials, give activated carbon the advantages of high specific surface area, high specific capacitance and electrochemical stability, which can ensure that it works within a wider potential window. This technology can also optimize the pore size distribution of activated carbon through process control, thereby improving its transmission efficiency in different electrolytes. It has been widely studied in cutting-edge fields such as supercapacitors, hydrogen storage, and green catalysts. However, the conductivity of activated carbon is one of the main reasons limiting its high-value application. Since some of the pores in activated carbon cannot be effectively utilized by electrolyte particles, its effective specific surface area is reduced. Usually, the conductivity of activated carbon is only 0.5-0.85S / m, which seriously limits its application performance in high power density environments.
[0003] Carbon fiber is a fiber material with good thermal conductivity, chemical stability and flexibility, and is easy to process into fabrics of various shapes and sizes. Although its conductivity is extremely high, the surface active sites of carbon fiber itself are relatively few, and it is usually necessary to treat the surface of the carbon fiber or functionalize it to increase its active sites when in use. Currently, functional modification on carbon fiber fabrics usually requires the use of adhesives, but the use of adhesives can easily reduce the conductivity of the carbon fiber itself on the one hand, and on the other hand, the modified carbon fiber fabric often has hollowing, warping, uneven thickness, etc. due to insufficient bonding strength, so its application scenarios are subject to certain restrictions. The characteristic of the present invention is that a surfactant is used as a coupling agent to achieve a "one-step" coupling of carbon fiber and activated carbon, and the coupling process is placed between the carbonization and activation processes, and the activated carbon layer is synchronously reinforced during thermal cracking, which simplifies the preparation process and saves costs, while ensuring the preparation of activated carbon cloth with both high conductivity and porous properties. The prepared activated carbon cloth also retains the flexibility of carbon fiber, and is presented in the form of activated carbon cloth, and its application field can be expanded by cutting, processing, etc. Summary of the Invention
[0004] The purpose of the embodiments of the present application is to provide a high-efficiency activated carbon cloth based on carbon fiber and a preparation method thereof, which simultaneously realizes the preparation of highly conductive and porous activated carbon during the thermal cracking process by simultaneously modifying the carbon fiber and the activated carbon precursor, thereby improving the conductive properties of the activated carbon while ensuring a high specific surface area, expanding the application field, and thus solving at least one technical problem involved in the background technology.
[0005] In order to solve the above technical problems, this application is implemented as follows:
[0006] A method for preparing high-efficiency activated carbon cloth based on carbon fiber comprises the following steps:
[0007] Step 1: Pre-treating sawdust; soaking the pre-treated sawdust raw materials in phosphoric acid solution, stirring, transferring to an atmosphere furnace, and thermally cracking under nitrogen protection to produce activated carbon precursor;
[0008] Step 2: Adding activated carbon precursor and surfactant into DMAC according to mass fraction, stirring, and ultrasonicating in an ultrasonic cell disruptor to prepare a conductive activated carbon precursor solution;
[0009] Step 3: Attach the first thickness of carbon fiber felt to a smooth glass plate, pour the conductive activated carbon precursor solution on it, and use a scraper to evenly scrape the solution onto the carbon fiber felt at the second thickness. Then, dry the carbon fiber felt in a vacuum drying oven to remove excess solvent.
[0010] Step 4: Place the composite carbon fiber felt in an atmosphere furnace for activation, and then wash with deionized water until the filtrate is neutral to obtain a high-efficiency activated carbon cloth.
[0011] In step 1, the thermal cracking temperature is 180-220° C. and the time is 0.5-2 h.
[0012] In step 2, the stirring temperature is 60-80° C., and the time is 0.5-2 h; the ultrasonic time is 30-120 s, and the power is 60-200 W.
[0013] In step three, the first thickness is 80-300 μm, and the second thickness is 200-1000 μm; the drying temperature is 105° C., and the drying time is 12 hours.
[0014] In step 4, the activation temperature is 350-450°C, the time is 1-2 hours; the deionized water temperature is 60-100°C.
[0015] In step 1, the mesh size of the sawdust raw material is 10-200 meshes; the mass fraction of the phosphoric acid is 40-60%; and the mass ratio of the sawdust to the phosphoric acid is 1:3.
[0016] In step 1, the sawdust raw material is pine, fir, medicinal residue or other wood waste, which is dried in a forced air drying oven at 105° C. for 24 hours to remove residual moisture before use.
[0017] In step 2, the surfactant is any one of styrene maleic anhydride, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, and Tween 80, and the mass fraction is 5-20%.
[0018] In step 2, the mass fraction of the activated carbon precursor is 10-50%, and the mass fraction of DMAC is 50-80%.
[0019] A high-efficiency activated carbon cloth based on carbon fibers is prepared by the preparation method.
[0020] Beneficial effects of the present invention:
[0021] 1. Coating an activated carbon precursor layer on the carbon fiber lining and then performing an activation treatment can improve the properties of the activated carbon, such as conductivity, flexibility, good mechanical properties and environmental stability;
[0022] 2. By linking the carbon fiber lining cloth and activated carbon through the abundant oxygen-containing functional groups on the surfactant, the interfacial area between the activated carbon layer and the carbon fiber layer can be ensured to be sufficiently strong without the use of adhesives, making the prepared activated carbon cloth more solid and reliable;
[0023] 3. During the activation and modification process, the oxygen-containing functional groups in the surfactant interact with the activated carbon surface through electrostatic interaction, hydrogen bonding, ion exchange and other mechanisms, changing the pores and surface charge distribution of the activated carbon cloth, thereby improving the adsorption capacity of the activated carbon cloth;
[0024] 4. The activated carbon cloth based on carbon fiber not only ensures the high specific surface area and porous structure of the activated carbon, but also greatly improves the conductive function by adopting carbon fiber composite modification technology, forming a double-layer carbon cloth structure with more stable performance and structure, laying a solid foundation for its application in supercapacitors, wires and cables, new energy batteries, environmental purification and other fields. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:
[0026] Figure 1 The scanning electron microscope morphology structures of Comparative Example (A), Example 1 (B), Example 2 (C) and Example 3 (D) provided in the examples of this application;
[0027] Figure 2 It is the infrared spectrum of the comparative example, embodiment 1, embodiment 2 and embodiment 3 provided in the examples of this application. DETAILED DESCRIPTION
[0028] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.
[0029] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.
[0030] The following describes in detail the method for preparing a high-efficiency activated carbon cloth based on carbon fiber provided in the embodiment of the present application through specific embodiments and their application scenarios in conjunction with the accompanying drawings.
[0031] The following is a detailed description of a method for preparing a high-efficiency activated carbon cloth based on carbon fiber provided by the embodiment of the present application using specific embodiments and comparative examples.
[0032] Example 1
[0033] Step 1: Accurately weigh 100g of pretreated sawdust raw material and 300g of 50% mass fraction phosphoric acid solution, place them in a 40℃ water bath and stir at constant temperature for 30min; transfer them to an atmosphere furnace, heat to 200℃ under nitrogen protection and pyrolyze for 30min to prepare an activated carbon precursor;
[0034] Step 2: Accurately weigh 30 g of activated carbon precursor and 10 g of styrene maleic anhydride into 60 g of DMAC, stir in a 70°C water bath for 40 min, transfer to an ultrasonic cell disruptor, and sonicate at 60 W for 30 s to prepare an activated carbon precursor solution;
[0035] Step 3: Attach a carbon fiber felt with a thickness of 80 μm to a smooth glass plate, pour the activated carbon precursor solution on it, and evenly scrape the precursor solution on the carbon fiber felt with a scraper at a thickness of 200 μm. Then, dry the carbon fiber felt in a vacuum drying oven at 105°C for 12 hours to remove excess solvent to form a composite carbon fiber felt.
[0036] Step 4: Transfer the composite carbon fiber felt into an atmosphere furnace and activate it at 400℃ for 40 minutes under nitrogen protection. Take it out and wash it with 80℃ deionized water for 3-5 times until the filtrate is neutral to obtain high-efficiency activated carbon cloth. The activated carbon cloth has a tensile strength of 41.74MPa and a specific surface area of 1298.43m 2 / g, and the electrical conductivity is 91.45S / m.
[0037] Example 2
[0038] Step 1: Accurately weigh 120g of pretreated sawdust raw material and 360g of 55% mass fraction phosphoric acid solution, place them in a 50℃ water bath and stir at constant temperature for 40min; transfer them to an atmosphere furnace and heat to 220℃ under nitrogen protection for thermal cracking for 50min to prepare an activated carbon precursor;
[0039] Step 2: Accurately weigh 40 g of activated carbon precursor and 10 g of sodium dodecylbenzenesulfonate into 50 g of DMAC, stir in a water bath at 80°C for 50 min, transfer to an ultrasonic cell disruptor, and sonicate at 120 W for 30 s to prepare an activated carbon precursor solution;
[0040] Step 3: Attach a 100 μm thick carbon fiber felt to a smooth glass plate, pour the activated carbon precursor solution onto it, and evenly scrape the precursor solution onto the carbon fiber felt with a scraper at a thickness of 300 μm. Then, dry the carbon fiber felt in a vacuum drying oven at 105°C for 12 hours to remove excess solvent to form a composite carbon fiber felt.
[0041] Step 4: Transfer the composite carbon fiber felt into an atmosphere furnace and activate it at 380°C for 65 minutes under nitrogen protection. Take it out and wash it with 90°C deionized water for 3-5 times until the filtrate is neutral to obtain a high-efficiency activated carbon cloth. The activated carbon cloth has a tensile strength of 57.25MPa and a specific surface area of 1597.73m 2 / g, and the electrical conductivity is 131.67S / m.
[0042] Example 3
[0043] Step 1: Accurately weigh 80g of pretreated sawdust raw material and 240g of 40% mass fraction phosphoric acid solution, place them in a 60℃ water bath and stir them at constant temperature for 60min; transfer them to an atmosphere furnace and heat them to 180℃ under nitrogen protection for 60min to produce an activated carbon precursor;
[0044] Step 2: Accurately weigh 50 g of activated carbon precursor and 15 g of sodium lauryl sulfate into 35 g of DMAC, stir in a 70°C water bath for 40 min, transfer to an ultrasonic cell disruptor, and sonicate at 200 W for 60 s to prepare an activated carbon precursor solution;
[0045] Step 3: Attach a 300 μm thick carbon fiber felt to a smooth glass plate, pour the activated carbon precursor solution onto it, and evenly scrape the precursor solution onto the carbon fiber felt with a scraper at a thickness of 400 μm. Then, dry the carbon fiber felt in a vacuum drying oven at 105°C for 12 hours to remove excess solvent to form a composite carbon fiber felt.
[0046] Step 4: Transfer the composite carbon fiber felt into an atmosphere furnace and activate it at 410°C for 70 minutes under nitrogen protection. Take it out and wash it with 100°C deionized water for 3-5 times until the filtrate is neutral to obtain a high-efficiency activated carbon cloth. The activated carbon cloth has a tensile strength of 48.72MPa and a specific surface area of 1423.94m 2 / g, conductivity is 102.33S / m.
[0047] Comparative Example (Carbon Fiber and Surfactant)
[0048] Step 1: Accurately weigh 16 g of sodium dodecyl sulfate precursor and place it in 45 g of DMAC. Stir the mixture in a 70°C water bath for 50 min. Then, transfer the mixture to an ultrasonic cell disruptor and sonicate at 80 W for 40 s to prepare a surfactant solution.
[0049] Step 2: Attach a 150um thick carbon fiber felt to a smooth glass plate, pour the above surfactant solution on it, and evenly scrape the surfactant solution on the carbon fiber felt with a scraper at a thickness of 300um. Then, place the carbon fiber felt in a vacuum drying oven at 105℃ and dry it for 12 hours to remove excess solvent to make a composite carbon fiber cloth. The carbon fiber cloth has a tensile strength of 5.87MPa and a specific surface area of 72.43m 2 / g, and the electrical conductivity is 76.31S / m.
[0050] Figure 1 The following are the surface morphology structures of the comparative example, example 1, example 2 and example 3 provided in the examples of this application under a scanning electron microscope. Figure 2 It can be seen that the surface of the carbon fiber cloth in the comparative example is mainly a strip-like fibrous structure, while the surface of Examples 1-3 prepared using this dough-leaving method is obviously changed to a more uniform and rough granular structure under a scanning electron microscope, and there are a large number of pore structures with different pore sizes in the gaps of the rough structure. On the one hand, this shows that the activated carbon is successfully loaded on the carbon cloth; on the other hand, it is consistent with the significant increase in the specific surface area of the activated carbon cloth in Examples 1-3.
[0051] Figure 2 The infrared spectra of the comparative example, example 1, example 2 and example 3 provided in the examples of this application are shown in FIG. Figure 2 It can be seen that compared with the comparative example, the examples 1-3 have a -1、1496.01cm -1 、1592.45cm -1 and 3028.04cm -1 There are new absorption peaks of different sizes at 1397.74 cm -1 and 1592.45cm -1 The peaks correspond to the symmetric stretching vibration peaks and antisymmetric stretching vibration peaks of the -COO- group in the carboxylate, respectively, indicating that the surface of the high-efficiency activated carbon cloth prepared by the method of the present invention has been enriched with oxygen-containing functional groups (carboxylate groups), which is conducive to the further functional modification and application expansion of the activated carbon cloth. In addition, Examples 1-3 have a peak at 1496.01 cm -1 and 3028.04cm -1 The newly added peaks at are relatively weak in intensity, but the spectral bands are sharp, corresponding to the C=C skeleton vibration in the benzene ring and the stretching vibration of the C-H bond of the aromatic hydrocarbon, respectively. This shows that the surfactant containing the benzene ring is successfully and stably loaded on the activated carbon cloth.
[0052] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.
[0053] In addition, it should be noted that the scope of the methods and preparation methods in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order depending on the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.
[0054] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.
Claims
1. A method for preparing high-efficiency activated carbon cloth based on carbon fiber, characterized by: The following steps are involved: Step 1: Pre-treating sawdust; The pretreated sawdust raw materials are immersed in phosphoric acid solution, stirred, transferred to an atmosphere furnace, and thermally cracked under nitrogen protection to produce activated carbon precursor; Step 2: Adding activated carbon precursor and surfactant into DMAC according to mass fraction, stirring, and ultrasonicating in an ultrasonic cell disruptor to prepare a conductive activated carbon precursor solution; Step 3: Attach the first thickness of carbon fiber felt to a smooth glass plate, pour the conductive activated carbon precursor solution on it, and use a scraper to evenly scrape the solution onto the carbon fiber felt at the second thickness. Then, dry the carbon fiber felt in a vacuum drying oven to remove excess solvent. Step 4: Place the composite carbon fiber felt in an atmosphere furnace for activation, and then wash with deionized water until the filtrate is neutral to obtain a high-efficiency activated carbon cloth.
2. The method for preparing a high-efficiency activated carbon cloth based on carbon fiber according to claim 1, characterized in that: In step 1, the thermal cracking temperature is 180-220° C. and the time is 0.5-2 h.
3. The method for preparing a high-efficiency activated carbon cloth based on carbon fiber according to claim 1, characterized in that: In step 2, the stirring temperature is 60-80° C., and the time is 0.5-2 h; the ultrasonic time is 30-120 s, and the power is 60-200 W.
4. The method for preparing a high-efficiency activated carbon cloth based on carbon fiber according to claim 1, characterized in that: In step three, the first thickness is 80-300 μm, and the second thickness is 200-1000 μm; the drying temperature is 105° C., and the drying time is 12 hours.
5. The method for preparing a high-efficiency activated carbon cloth based on carbon fiber according to claim 1, characterized in that: In step 4, the activation temperature is 350-450°C, the time is 1-2 hours; the deionized water temperature is 60-100°C.
6. The method for preparing a high-efficiency activated carbon cloth based on carbon fiber according to claim 1, characterized in that: In step 1, the mesh size of the sawdust raw material is 10-200 meshes; the mass fraction of the phosphoric acid is 40-60%; and the mass ratio of the sawdust to the phosphoric acid is 1:
3.
7. The method for preparing a high-efficiency activated carbon cloth based on carbon fiber according to claim 1, characterized in that: In step 1, the sawdust raw material is pine, fir, medicinal residue or other wood waste, which is dried in a forced air drying oven at 105° C. for 24 hours to remove residual moisture before use.
8. The method for preparing a high-efficiency activated carbon cloth based on carbon fiber according to claim 1, characterized in that: In step 2, the surfactant is any one of styrene maleic anhydride, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, and Tween 80, and the mass fraction is 5-20%.
9. The method for preparing a high-efficiency activated carbon cloth based on carbon fiber according to claim 1, characterized in that: In step 2, the mass fraction of the activated carbon precursor is 10-50%, and the mass fraction of DMAC is 50-80%.
10. A high-efficiency activated carbon cloth based on carbon fiber, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 9.