Nitrogen-doped resin carbon material, preparation method and application thereof
By pre-oxidizing the resin material and reacting ammonia, nitrogen-doped resin carbon materials are formed, which solves the problem of insufficient conductivity of traditional resin carbon materials, achieves higher conductivity and porosity, and improves the electron transmission efficiency and structural stability of silicon carbon materials.
Patent Information
- Application Number
- CN202510502555.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2025-07-25
AI Technical Summary
Traditional resin carbon materials have low porosity and poor electrical conductivity, which cannot effectively improve the conductivity and electron transmission efficiency of silicon carbon materials, limiting their application in high-performance lithium-ion batteries.
By pre-oxidizing the resin material and reacting with ammonia at 800°C, a C-O-C bond and C=O bond are formed, a three-dimensional crosslinking network is enhanced, and a -NH2 free radical is generated and a carbon framework is reacted to form C-N bonds, etching the voids, and improving porosity and conductivity.
The conductivity of nitrogen-doped resin carbon material is improved, so that it can show higher electron transmission efficiency and structural stability in silicon-carbon composite materials, meeting the needs of high-performance lithium-ion batteries.
Smart Images
Figure CN120364673A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of carbon materials, and particularly relates to a nitrogen-doped resin carbon material, a preparation method thereof, and an application thereof. Background Art
[0002] With the rapid development of modern electronic devices and new energy vehicles, the demand for high-performance battery electrode materials is becoming increasingly urgent. Due to its high theoretical specific capacity, silicon-carbon materials have become potential next-generation anode materials for lithium-ion batteries, and are expected to significantly improve the energy density of batteries and meet the long-range requirements of devices. However, silicon undergoes a huge volume change during charge and discharge, resulting in the collapse of the material structure and a sharp decline in cycle performance; at the same time, its intrinsic conductivity is poor and the electron transport efficiency is low, which severely limits the actual application performance of silicon-carbon materials in batteries.
[0003] To solve the above problems of silicon-carbon materials, a large number of studies have been carried out by researchers. Among them, compounding with highly conductive carbon materials is one of the main strategies. Porous carbon materials, with their high specific surface area, rich pore structure, and good conductivity, can effectively buffer the volume change of silicon and provide a fast electron transport channel, becoming an ideal carbon source for silicon-carbon composites. At present, there are a variety of precursors for preparing porous carbon. Among them, resin carbon has received extensive attention due to its wide source, easy molding, and easy regulation.
[0004] The resin carbon prepared by traditional methods has a relatively dense internal structure and a low porosity, resulting in poor conductivity. This makes the porous carbon prepared from it, even after activation to obtain a rich pore structure, still difficult to fully play its role in improving the conductivity of silicon-based composites due to the weak initial conductivity foundation when applied to silicon-carbon materials, and unable to effectively meet the stringent requirements of high-performance silicon-carbon anode materials for fast electron transport, restricting the further development of silicon-carbon materials in the field of high-power batteries. Summary of the Invention
[0005] This application aims to at least partly solve one of the above technical problems in the prior art. To this end, an embodiment of this application provides a nitrogen-doped resin carbon material, a preparation method thereof, and an application thereof, which have higher conductivity.
[0006] A preparation method of a nitrogen-doped resin carbon material includes the following steps:
[0007] Step 1: Select a resin material as the carbon source precursor material and perform a drying treatment on the resin material;
[0008] Step 2: Place the dried resin material in a reaction ark and pre-oxidize it in an air atmosphere for 2 h - 8 h, and the pre-oxidation temperature is 160°C - 240°C;
[0009] Step 3: Add the pre-oxidized resin material into a rotary atmosphere furnace and evacuate the air in the rotary furnace.
[0010] Step 4: Continuously introduce ammonia gas with a mass volume of more than 99.9% into the rotary atmosphere furnace, start the heating program to start carbonization, and at the same time, the rotary furnace starts to rotate. Heat the rotary atmosphere furnace to 800 °C at a heating rate of 2 - 10 °C / min, and then keep it at a constant temperature for 1 - 6 h.
[0011] Step 5: After the heat preservation ends, stop introducing ammonia gas into the rotary furnace, and continuously introduce inert gas or nitrogen with a mass volume of more than 99.99% into the rotary furnace. Under an inert atmosphere, naturally cool it to room temperature.
[0012] In an optional or preferred embodiment, the step of drying the resin material in Step 1 includes: placing the resin material in a vacuum drying oven at 85 °C and drying it for 12 h.
[0013] In an optional or preferred embodiment, in Step 2, the pre-oxidation temperature is 160 °C - 240 °C.
[0014] In an optional or preferred embodiment, in Step 3, introduce inert gas or nitrogen into the rotary furnace to evacuate the air in the rotary furnace.
[0015] In an optional or preferred embodiment, in Step 4, the rotation speed of the rotary furnace is 1.5 revolutions per minute.
[0016] In an optional or preferred embodiment, in Step 4, heat the rotary atmosphere furnace to 800 °C at a heating rate of 4 °C / min and keep it at a constant temperature for 2 h.
[0017] In an optional or preferred embodiment, the resin material is phenolic resin.
[0018] In an optional or preferred embodiment, the particle size of the resin material is 0 - 10 um.
[0019] A nitrogen-doped resin carbon material, characterized in that it is prepared by using the preparation method of the nitrogen-doped resin carbon material described in any one of the above.
[0020] An application of a nitrogen-doped resin carbon material, the application of the nitrogen-doped resin carbon material includes using the nitrogen-doped resin carbon material prepared as described above.
[0021] Based on the above technical solutions, the embodiments of the present application have at least the following beneficial effects: Through the pre-oxidation of the resin material and the reaction of ammonia gas with the resin material at a temperature of 800 °C in the present application, the conductivity of the prepared nitrogen-doped resin carbon material is improved. This is because after the phenolic resin is pre-oxidized, more C-O-C bonds and C=O bonds are formed between the molecular chains, enhancing the three-dimensional cross-linked network. At the same time, the -NH2 free radicals generated by the pyrolysis of NH3 react with the carbon skeleton of the resin to form C-N bonds and etch voids, thereby increasing the porosity of the nitrogen-doped resin carbon material and making the conductivity of the nitrogen-doped resin carbon material higher. Description of the Drawings
[0022] The following further describes the present application in conjunction with the drawings and embodiments;
[0023] Figure 1 is the scanning electron microscope image of the nitrogen-doped resin carbon material prepared in Example 1;
[0024] Figure 2 is the graph of the resistivity change with pressure for Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4 of the present application. Detailed Embodiments
[0025] To make the above objects, features, and advantages of the present application more obvious and understandable, the following provides a detailed description of the specific embodiments of the present application in conjunction with the drawings. Many specific details are set forth in the following description to facilitate a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.
[0026] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application.
[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.
[0028] In this application, unless otherwise clearly defined and limited, terms such as "installed", "connected", "linked", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0029] In this application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.
[0030] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.
[0031] With the rapid development of modern electronic devices and new energy vehicles, the demand for high-performance battery electrode materials is becoming increasingly urgent. Due to its high theoretical specific capacity, silicon-carbon materials have become a promising next-generation anode material for lithium-ion batteries, which is expected to significantly improve the battery energy density and meet the long-term battery life requirements of devices. However, silicon undergoes a huge volume change during charge and discharge, resulting in the collapse of the material structure and a sharp decline in cycle performance. At the same time, its intrinsic conductivity is poor and the electron transport efficiency is low, which severely limits the practical application performance of silicon-carbon materials in batteries.
[0032] To solve the above problems of silicon-carbon materials, researchers have conducted a large number of studies, and one of the main strategies is to composite with highly conductive carbon materials. Porous carbon materials, with their high specific surface area, rich pore structure and good conductivity, can effectively buffer the volume change of silicon and provide a fast electron transport channel, becoming an ideal carbon source for silicon-carbon composite materials. At present, there are a wide variety of precursors for preparing porous carbon. Among them, resin carbon has received extensive attention due to its advantages such as wide source, easy shaping and regulation.
[0033] The resin carbon prepared by traditional methods has a relatively dense internal structure, low porosity and imperfect conductive network, resulting in poor conductivity of itself. This makes the porous carbon prepared from it, even though it obtains a rich pore structure after activation, still difficult to fully play its role in improving the conductivity of silicon-based composite materials due to the weak initial conductivity foundation when applied to silicon-carbon materials, and cannot effectively meet the stringent requirements of high-performance silicon-carbon anode materials for fast electron transport, restricting the further development of silicon-carbon materials in the field of high-power batteries.
[0034] This application provides a preparation method of a nitrogen-doped resin carbon material, including the following steps
[0035] Step 1: Select a resin material as the carbon source precursor material and dry the resin material.
[0036] Step 2: Place the dried resin material in a reaction ark and pre-oxidize it in an air atmosphere for 2 h - 8 h, and the pre-oxidation temperature is 160°C - 240°C.
[0037] Step 3: Add the pre-oxidized resin material to a rotary atmosphere furnace and evacuate the air in the rotary furnace.
[0038] Step 4: Continuously introduce ammonia with a mass volume of more than 99.9% into the rotary atmosphere furnace, start the heating program to start carbonization, and at the same time the rotary furnace starts to rotate. Heat the rotary atmosphere furnace to 700 - 850°C at a heating rate of 2 - 10°C / min and then keep it warm for 1 - 6 h.
[0039] Step 5: After the heat preservation is completed, stop introducing ammonia into the rotary furnace, continuously introduce an inert gas or nitrogen with a mass volume of more than 99.99% into the rotary furnace, and cool it naturally to room temperature in an inert atmosphere.
[0040] In this application, through the pre-oxidation of the resin material and the reaction of ammonia gas with the resin material at a temperature of 800 °C, the conductivity of the prepared nitrogen-doped resin carbon material is improved. This is because after the phenolic resin is pre-oxidized, more C-O-C bonds and C=O bonds are formed between the molecular chains, strengthening the three-dimensional cross-linked network. At the same time, the -NH2 free radicals generated by the pyrolysis of NH3 react with the carbon skeleton of the resin to form C-N bonds and etch voids, thereby increasing the porosity of the nitrogen-doped resin carbon material and making the conductivity of the nitrogen-doped resin carbon material higher.
[0041] In some embodiments, the step of drying the resin material in step (1) includes: placing the resin material in a vacuum drying oven at 85 °C and drying for 12 h.
[0042] In some embodiments, in step (2), the pre-oxidation temperature is 160 °C - 240 °C.
[0043] In some embodiments, in step (3), an inert gas or nitrogen is introduced into the rotary furnace to exhaust the air in the rotary furnace completely. This is to avoid the influence of the oxygen contained in the air on the implementation of subsequent step (4).
[0044] In some embodiments, in step (4), the rotation speed of the rotary furnace is 1.5 revolutions per minute.
[0045] In some embodiments, in step (4), the rotary atmosphere furnace is heated to 800 °C at a heating rate of 4 °C / min and held for 2 h. Heating to 800 °C can effectively reduce the resistivity of the prepared nitrogen-doped resin carbon material.
[0046] In some embodiments, the resin material is phenolic resin.
[0047] In some embodiments, the particle size of the resin material is 0 - 10 μm.
[0048] This application also provides a nitrogen-doped resin carbon material, which is prepared by using the preparation method of the nitrogen-doped resin carbon material described in any one of the above.
[0049] This application also provides an application of the nitrogen-doped resin carbon material. The application of the nitrogen-doped resin carbon material includes the nitrogen-doped resin carbon material prepared by the above method.
[0050] The following is a detailed description of this application using phenolic resin as the resin material:
[0051] Example 1:
[0052] Step (1): Select phenolic resin as the carbon source precursor material, and place the phenolic resin with a particle size of 0 - 10 μm in a vacuum drying oven at 85 °C and dry for 12 h.
[0053] Step (2): Take the dried phenolic resin and place it in a graphite ark, then transfer it to a forced-air drying oven for pre-oxidation treatment. Pre-oxidize it at 220 °C for 3 h in an air atmosphere.
[0054] Step (3): Feed the pre-oxidized phenolic resin into a rotary atmosphere furnace.
[0055] Step (4): Continuously introduce nitrogen with a mass volume of more than 99.99% into the rotary furnace for 1 hour to completely displace the air in the rotary furnace.
[0056] Step (5): After 1 hour, stop introducing nitrogen with a mass volume of more than 99.99% into the rotary furnace, continuously introduce ammonia with a mass volume of more than 99.9% into the rotary furnace, start the heating program for carbonization, set the rotation speed of the rotary furnace to 1.5 rpm, heat up to 800 °C at a heating rate of 4 °C / min, and hold for 2 h.
[0057] Step (6): After the holding is completed, stop introducing ammonia with a mass volume of more than 99.9% into the rotary furnace, continuously introduce nitrogen with a mass volume of more than 99.99% into the rotary furnace, and naturally cool to room temperature under an inert atmosphere to obtain a nitrogen-doped resin carbon material. Its SEM image is as Figure 1 shown.
[0058] Use an automated powder resistivity tester to test the nitrogen-doped resin carbon material prepared in Example 1. The data shows that at a pressure of 30 MPa, its resistivity is 0.11 Ω / cm.
[0059] Comparative Example 1:
[0060] This example provides a preparation method of a nitrogen-doped resin carbon material, and the difference from Example 1 is only that: in step (5), the carbonization temperature of 800 °C is adjusted to 700 °C, and the other steps and parameters are the same as those in Example 1.
[0061] Use an automated powder resistivity tester to test the nitrogen-doped resin carbon material obtained in Comparative Example 1. It is measured that at a pressure of 30 MPa, its resistivity is 1.15 Ω / cm.
[0062] Comparative Example 2:
[0063] This example provides a preparation method of a nitrogen-doped resin carbon material, and the difference from Example 1 is only that step (2) is omitted and pre-oxidation treatment is not carried out. The other steps and parameters are the same as those in Example 1.
[0064] Use an automated powder resistivity tester to test the nitrogen-doped resin carbon material obtained in Comparative Example 2. The data shows that at a pressure of 30 MPa, the resistivity is 0.13 Ω / cm.
[0065] Comparative Example 3:
[0066] Comparative Example 1 provided a method for preparing a resin carbon material, and its operation steps were as follows:
[0067] Step (1): Select phenolic resin as the carbon source precursor material, and place the phenolic resin with a particle size of about 0 - 10 μm in a vacuum drying oven at 85°C for 12 h.
[0068] Step (2): Take the dried phenolic resin and place it in a graphite ark, and then transfer it to a blast drying oven for pre-oxidation treatment. Pre-oxidize at 220°C for 3 h in an air atmosphere.
[0069] Step (3): Feed the pre-oxidized phenolic resin into a rotary atmosphere furnace.
[0070] Step (4): Continuously introduce nitrogen with a mass volume of more than 99.99% into the rotary furnace for 1 h to completely displace the air in the rotary furnace.
[0071] Step (5): After 1 h, continuously introduce nitrogen with a mass volume of more than 99.99% into the rotary furnace, start the heating program to start carbonization, set the rotation speed of the rotary furnace to 1.5 rpm, and increase the temperature to 800°C at a heating rate of 4°C / min, and hold for 2 h.
[0072] Step (6): After the heat preservation is completed, naturally cool to room temperature under an inert atmosphere to obtain the resin carbon material of Comparative Example 1.
[0073] Test the resin carbon material of Comparative Example 3 with an automated powder resistivity tester. The data shows that at a pressure of 30 MPa, the resistivity is 0.22 Ω / cm.
[0074] Comparative Example 4:
[0075] Comparative Example 2 provided a method for preparing a resin carbon material. The difference from Example 1 was that the phenolic resin did not undergo the pre-oxidation treatment in step (2), and ammonia was not introduced for N doping during the carbonization process in step (5). The remaining steps and parameters were the same as those in Example 1.
[0076] Test Comparative Example 4 with an automated powder resistivity tester. The data shows that at a pressure of 30 MPa, its resistivity is 0.18 Ω / cm.
[0077] Figure 1 Showed the scanning electron microscope image of the nitrogen-doped resin carbon material prepared in Example 1, Figure 2 Showed the resistivity change situations of Example 1 and each comparative example.
[0078] In summary, through the pre-oxidation combined with ammonia doping process, the present application provides a high-performance and low-cost carbon matrix solution for the silicon-carbon anode material.
[0079] The embodiments of the present application have been described in detail above in conjunction with the accompanying drawings. However, the present application is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present application within the scope of knowledge possessed by those of ordinary skill in the art.
Claims
1. A preparation method of a nitrogen-doped resin carbon material, characterized in that, It includes the following steps: Step 1: Select a resin material as the carbon source precursor material and perform a drying treatment on the resin material; Step 2: Take the dried resin material and place it in a reaction ark, and pre-oxidize it in an air atmosphere for 2h - 8h, with the pre-oxidation temperature being 160°C - 240°C; Step 3: Add the pre-oxidized resin material to a rotary atmosphere furnace and evacuate the air in the rotary furnace; Step 4: Continuously introduce ammonia with a mass volume of more than 99.9% into the rotary atmosphere furnace, start the heating program to start carbonization, and at the same time the rotary furnace starts to rotate. Heat the rotary atmosphere furnace to 800°C at a heating rate of 2 - 10°C / min, and then hold the temperature for 1 - 6h. Step 5: After the heat preservation ends, stop introducing ammonia into the rotary furnace, continuously introduce an inert gas or nitrogen with a mass volume of more than 99.99% into the rotary furnace, and under an inert atmosphere, naturally cool to room temperature.
2. The preparation method of the nitrogen-doped resin carbon material according to claim 1, characterized in that: The step of performing a drying treatment on the resin material in Step 1 includes: placing the resin material in a vacuum drying oven at 85°C and drying it for 12h.
3. The preparation method of the nitrogen-doped resin carbon material according to claim 1, wherein: In Step 2, the pre-oxidation temperature is 160°C - 240°C.
4. The preparation method of the nitrogen-doped resin carbon material according to claim 1, characterized in that: In Step 3, introduce an inert gas or nitrogen into the rotary furnace to evacuate the air in the rotary furnace.
5. The preparation method of the nitrogen-doped resin carbon material according to claim 1, characterized in that: In Step 4, the rotation speed of the rotary furnace is 1.5 revolutions per minute.
6. The preparation method of the nitrogen-doped resin carbon material according to claim 5, wherein: In Step 4, heat the rotary atmosphere furnace to 800°C at a heating rate of 4°C / min and hold the temperature for 2h.
7. The preparation method of the nitrogen-doped resin carbon material according to claim 1, characterized in that: The resin material is phenolic resin.
8. The preparation method of the nitrogen-doped resin carbon material according to claim 7, characterized in that: The particle size of the resin material is 0 - 10um.
9. A nitrogen-doped resin carbon material, characterized in that, It is made by using the preparation method of the nitrogen-doped resin carbon material described in any one of Claims 1 to 8.
10. Application of a nitrogen-doped resin carbon material, characterized in that, The application of the nitrogen-doped resin carbon material includes using the nitrogen-doped resin carbon material prepared in Claim 9.