Device and process for producing hard carbon negative electrode material by detonation method
Patent Information
- Application Number
- CN202510353567.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-25
- Publication Date
- 2026-09-29
AI Technical Summary
[0009]综上所述，生物质基比容量较高，当前产业化进程最快，但存在产品结构不一致问题和潜在保供风险；树脂基产品结构可调，一致性高，当前比容量最高且仍有较大提升空间，产品原料均为成熟化工用品，具备批量放大能力，但缺点是成本过高，当前达6万/吨，约为其他路径的2～3倍；沥青基和煤基在性能上存在一定瑕疵，克容量和纯度较低，仍需持续改善
[0030]1、本发明的爆轰法生产硬碳负极材料的装置，利用电磁打火装置进行远程打火，并通过温度传感器和压力传感器实时监测和控制爆轰过程，最终获得高首效和高容量的硬碳负极材料，整个工艺简单，成本低廉；
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Figure CN122828623A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of hard carbon material production, and more specifically, to an apparatus and process for producing hard carbon anode materials by detonation. Background Technology
[0002] Sodium-ion batteries are similar in composition to lithium-ion batteries, consisting of a positive electrode, a negative electrode, an electrolyte, a separator, and a current collector. Currently, the negative electrode material is one of the core bottlenecks restricting the industrialization of sodium batteries: on the one hand, there is still no consensus on the sodium storage mechanism of the sodium battery negative electrode, with many mechanism models existing, such as intercalation, adsorption, and pore filling; on the other hand, the performance of current negative electrode materials under verification varies, and product stability is poor, requiring urgent breakthroughs.
[0003] Currently, research on sodium-ion battery anode materials mainly includes carbon-based anode materials, titanium-based anode materials, conversion reaction-type anode materials, and intermetallic compound anode materials. Among these, carbon-based anode materials are widely used in lithium batteries due to their wide availability, low cost, and ease of preparation, making them the preferred anode material for sodium-ion batteries. Carbon-based materials can be further classified into graphitic carbon and amorphous carbon based on their degree of graphitization. Currently widely used graphite anode materials are incompatible with sodium batteries: First, the radius of sodium ions (0.106 nm) is much larger than that of lithium ions (0.076 nm), resulting in greater resistance to sodium ion migration in the crystal lattice and making it difficult for sodium ions to effectively intercalate between graphite layers, exhibiting slow reaction kinetics; relevant data show that the sodium storage specific capacity of graphite is only 35 mAh / g (the theoretical lithium storage specific capacity of graphite can reach 372 mAh / g, and the actual mass production is about 350 mAh / g); Second, the larger sodium ion radius leads to greater lattice stress in graphite materials, which in turn leads to lattice collapse and poor material cycling stability during electrochemical cycling; Third, the interaction between sodium ions and graphite layers is weak, and the energy required for the two to form a compound is higher than 0, resulting in thermodynamic instability. Therefore, sodium-ion batteries cannot use the graphite system of lithium-ion batteries for their anode materials, but mainly use amorphous carbon. Amorphous carbon is divided into soft carbon and hard carbon according to the ease of graphitization. Both are produced by the pyrolysis of organic precursors at temperatures of 500–1500℃. Soft carbon can be transformed into graphitized carbon above 2000℃, while hard carbon retains its amorphous structure. Different precursors result in different amorphous carbon anode materials. The core difference between soft and hard carbon lies in the cross-linking relationship of the carbon layers in the microstructure, which is closely related to the structure and shape of the precursor used. The crystal structure of soft carbon is similar to graphite, but the order of the graphite microcrystals is not as high as that of graphite, with a small number of wrinkles and stacking faults, which is beneficial for the storage of sodium ions. In addition, the carbon layers of soft carbon are more regularly arranged, resulting in higher conductivity and better rate performance. However, the disadvantage is that the specific capacity is relatively low, about 200 mAh / g. Hard carbon possesses high mechanical hardness, large interlayer spacing, and disordered micropores, resulting in more sodium storage sites and thus a high specific capacity, typically reaching 300 mAh / g. However, the numerous defects and large specific surface area of hard carbon easily induce other irreversible reactions, leading to a lower initial efficiency of the battery. In summary, due to its advantages over soft carbon in specific capacity, low-temperature performance, and rate capability, hard carbon has become the mainstream research direction for sodium battery anodes. However, the difficulties in compaction and low initial efficiency of hard carbon materials are problems that urgently need to be solved.
[0004] As one of the key upstream raw materials for sodium batteries, hard carbon anodes have precursors that are generally classified into different types, such as biomass-based, resin-based, pitch-based, and coal-based, depending on the carbon source.
[0005] Biomass-based: There are many types of biomass, and dozens of materials can be used to prepare hard carbon, including various fruit shells, plant tubers, and fibers. Among them, coconut shells, starch, bamboo, and straw have advantages in bulk density and initial efficiency, and are currently the mainstream choices. In relevant foreign studies, coconut shells are used as raw materials, and then carbonized, crushed, alkali-treated, heat-treated and purified, and CVD treated. Among them, the CVD treatment process is more difficult, which is the key link that widens the gap with domestic research.
[0006] Resin-based resins can be directly synthesized into hard carbon materials through chemical synthesis. The precursor molecules have simple structures, and their molecular structures can be designed as needed to precisely control pore structure and active sites. The resulting products exhibit good consistency, high specific capacity, and significant performance advantages. For example, a research team at Shanghai University used ethanol as a pore-forming agent. By curing liquid phenolic resin using a solvothermal method, ethanol was uniformly dispersed in the precursor. The carbonization process of the precursor gradually releases internal ethanol molecules, which act as activators and construct a large number of nanoscale closed micropores, resulting in a specific capacity of up to 410 mAh / g for the hard carbon.
[0007] Asphalt-based: Asphalt is a common petroleum industry residue, widely available, inexpensive, and with high carbon yield, making it a highly sought-after precursor for hard carbon. Asphalt-based precursors offer significant cost-effectiveness advantages; however, untreated asphalt easily forms a graphite-like structure during carbonization, which is detrimental to sodium storage, with a sodium storage capacity of only about 90 mAh / g. Therefore, asphalt-based precursors require pretreatment before carbonization. One method is to use a cross-linking agent to cross-link the asphalt, altering its microstructure and hindering the growth of graphite crystals during pyrolysis carbonization, followed by solid-phase carbonization to obtain hard carbon materials. Another method is pre-oxidation, using oxidants (potassium permanganate, nitric acid, and hydrogen peroxide, etc.) to pre-oxidize the asphalt, obtaining pre-oxidized asphalt with a certain oxygen content. Due to the presence of oxygen heteroatoms, the asphalt is less likely to form an ordered structure during pyrolysis carbonization, thus yielding hard carbon materials with a three-dimensional cross-linked structure. According to relevant research, after a simple pre-oxidation process, the performance of a certain asphalt carbonized was significantly improved, with the carbon production rate increasing from 54% to 67%, the sodium storage capacity increasing from 94 mAh / g to 300 mAh / g, and the initial efficiency increasing from 64.2% to 88.6%.
[0008] Coal-based: Coal has the advantages of abundant resources and low price; according to the degree of coalification, it can be divided into lignite, sub-bituminous coal, bituminous coal and anthracite. Anthracite is the most coalified type, with high carbon content and low impurity content, making it a suitable precursor for preparing hard carbon anodes.
[0009] In summary, biomass-based products have a high specific capacity and are currently the fastest in industrialization process, but they suffer from inconsistent product structures and potential supply risks. Resin-based products have adjustable product structures and high consistency, currently have the highest specific capacity and still have considerable room for improvement, and their raw materials are all mature chemical products, enabling large-scale production. However, their drawback is the high cost, currently reaching 60,000 RMB / ton, which is about 2 to 3 times that of other methods. Asphalt-based and coal-based products have certain performance defects, with lower specific capacity and purity, and still need continuous improvement.
[0010] The future development focuses of the aforementioned precursors differ. For high-performance applications, such as those requiring a specific capacity of 350mAh / g and an initial efficiency >92%, polymer- or resin-based hard carbon may have unique advantages. For cost-sensitive conventional applications, it's necessary to consider product types with slightly lower performance but significantly better cost-effectiveness, such as pitch-based and coal-based materials, which may become more attractive after technological breakthroughs. In general, since a major driving force behind the introduction of sodium batteries is cost reduction, low-cost hard carbon anode materials are a key factor in the subsequent large-scale promotion of sodium batteries. The cost of hard carbon anode products is closely related to the source, quality, storage, transportation, processing flow, and process complexity of upstream raw materials. Even factors such as the types of processing-related chemicals, the ease of meeting environmental standards, and the localization rate of production equipment all have a significant impact on the final cost of mass-produced hard carbon anodes.
[0011] In view of the above, there is an urgent need to develop a low-cost technology for producing hard carbon anode materials in order to obtain high-quality hard carbon anode materials. Summary of the Invention
[0012] To address the shortcomings of existing technologies, the purpose of this invention is to provide an apparatus and process for producing hard carbon anode materials using a detonation method. This method achieves low-cost production while simultaneously obtaining hard carbon anode materials with high initial efficiency and high capacity.
[0013] To achieve the above objectives, the present invention adopts the following technical solution:
[0014] A first aspect of the present invention provides an apparatus for producing hard carbon anode materials by detonation, comprising a detonation device and a remote controller;
[0015] The detonation device is used to detonate a carbon source; the detonation device includes a detonation cylinder and a vacuum pump and a remote ignition device respectively connected to the detonation cylinder; the detonation cylinder is equipped with a temperature sensor and a pressure sensor; the vacuum pump is connected to the detonation cylinder through a vacuum pipeline, the vacuum pipeline is connected to a vent branch pipe connected to the detonation gas, the vacuum pipeline is equipped with a vacuum valve to control the opening and closing of the pipeline, and the vent branch pipe is equipped with a regulating valve; the remote ignition device ignites the detonation gas inside the detonation cylinder by remote ignition.
[0016] The remote controller is connected to a vacuum pump, a remote ignition device, a temperature sensor, a pressure sensor, a vacuum valve, and a regulating valve. The remote controller receives the temperature and pressure detected by the temperature and pressure sensors in real time, adjusts the pressure of the detonation equipment through the vacuum pump and vacuum valve, controls the amount of detonation gas loaded through the regulating valve, and controls the remote ignition device to ignite the detonation gas in the detonation equipment, thereby completing the detonation treatment of the carbon source and finally obtaining a hard carbon anode material.
[0017] Preferably, one side of the detonation tube is provided with a charging slide and a charging flange, and the charging flange is installed on the detonation tube via the charging slide; the other side of the detonation tube is provided with a sealing flange, and the remote ignition device is installed on the sealing flange.
[0018] Preferably, the detonation cylinder and the loading slide are made of 316L stainless steel.
[0019] Preferably, the loading flange and the sealing flange are sealed by a sealing ring.
[0020] Preferably, the sealing ring is a graphite gasket or a vermiculite gasket.
[0021] Preferably, the remote ignition device is an electromagnetic ignition device, and the start button of the electromagnetic ignition device is located on the remote controller.
[0022] A second aspect of the present invention provides a process for producing hard carbon anode materials by detonation, comprising the following steps performed using an apparatus for producing hard carbon anode materials by detonation as described in the first aspect of the present invention:
[0023] S1, after the asphalt or resin-based carbon source is pulverized to 1-3 μm by airflow, it is loaded into the detonation cylinder of the detonation equipment;
[0024] S2, the remote controller closes the regulating valve, opens the vacuum valve, and starts the vacuum pump to evacuate the detonation equipment to an absolute pressure of 1-10 kPa;
[0025] S3, the remote controller shuts off the vacuum pump and vacuum valve, opens the regulating valve, and introduces the detonation gas into the detonation equipment. The detonation gas is obtained by mixing H2 and O2 or C2H2 and O2.
[0026] S4, the remote controller closes the regulating valve, starts the remote ignition device, ignites the detonation gas, and instantly obtains hard carbon anode material.
[0027] Preferably, in step S4, the detonation temperature when the detonation gas is ignited is 1400–2100°C.
[0028] Preferably, the compaction density of the hard carbon anode material is 2-3 g / cm³. 3The initial efficacy is 85-89%, and the reversible capacity is 330-350 mAh / g.
[0029] The effects of this invention are as follows:
[0030] 1. The apparatus for producing hard carbon anode material by detonation method of the present invention uses an electromagnetic ignition device for remote ignition and monitors and controls the detonation process in real time through temperature and pressure sensors, and finally obtains hard carbon anode material with high initial efficiency and high capacity. The whole process is simple and low cost.
[0031] 2. This invention uses the detonation method, which can make the detonation temperature reach 1400-2100℃, ensuring the formation of a stable and reliable hard carbon anode material. In addition, by controlling the amount of air detonation gas and the amount of asphalt filling, the uniform particle size of the hard carbon anode material can be ensured.
[0032] 3. The hard carbon anode material obtained by this invention achieves an initial efficiency of 85-89% and a reversible capacity of 330-350 mAh / g, solving the problem of low initial efficiency in current sodium-ion batteries. Attached Figure Description
[0033] Figure 1 This is a schematic diagram of the apparatus for producing hard carbon anode material by detonation method according to the present invention;
[0034] Figure 2 This is a schematic diagram of the detonation device of the present invention;
[0035] Figure 3 Here is a SEM image of the hard carbon anode material prepared according to an embodiment of the present invention;
[0036] Among them, 1. Detonation equipment; 2. Remote ignition device; 3. Vacuum pump; 4. Remote controller; 5. Temperature sensor; 6. Pressure sensor; 7. Vacuum pipeline; 8. Ventilation branch pipe; 9. Vacuum valve; 10. Regulating valve; 11. Detonation cylinder; 12. Loading flange; 13. Sealing flange; 14. Loading slide bar. Detailed Implementation
[0037] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.
[0038] Combination Figure 1 , Figure 2As shown, the present invention provides an apparatus for producing hard carbon anode materials by detonation, comprising a detonation device 1 and a remote controller 4. The detonation device 1 is used to detonate a carbon source; the detonation device 1 includes a detonation cylinder 11 and a vacuum pump 3 and a remote ignition device 2 respectively connected to the detonation cylinder 11; the detonation cylinder 11 is equipped with a temperature sensor 5 and a pressure sensor 6; the vacuum pump 3 is connected to the detonation cylinder 11 through a vacuum pipe 7, and a ventilation branch pipe 8 connected to the detonation gas is connected to the vacuum pipe 7. The vacuum pipe 7 is equipped with a vacuum valve 9 for controlling the opening and closing of the pipe, and the ventilation branch pipe 8 is equipped with a regulating valve 10; the remote ignition device 2 ignites the detonation gas in the detonation cylinder 11 by remote ignition. The remote controller 4 is connected to the vacuum pump 3, the remote ignition device 2, the temperature sensor 5, the pressure sensor 6, the vacuum valve 9, and the regulating valve 10. The remote controller 4 receives the temperature and pressure detected by the temperature sensor 5 and the pressure sensor 6 in real time, adjusts the pressure of the detonation device 1 through the vacuum pump 3 and the vacuum valve 9, controls the amount of detonation gas loaded through the regulating valve 10, and controls the remote ignition device 2 to ignite the detonation gas in the detonation device 1, thereby completing the detonation treatment of the carbon source and finally obtaining the hard carbon anode material.
[0039] Combination Figure 2 As shown, a charging slide bar 14 and a charging flange 12 are provided on one side of the detonation tube 11. The charging flange 12 is mounted on the detonation tube 11 via the charging slide bar 14. The charging slide bar 14 is designed here to facilitate the disassembly of the charging flange 12. The charging slide bar 14 can be bolted to the detonation tube 11. A sealing flange 13 is provided on the other side of the detonation tube 11, and the remote ignition device 2 is mounted on the sealing flange 13. In a specific embodiment, the detonation tube 11 and the charging slide bar 14 are made of 316L stainless steel, and the corresponding dimensions can be customized according to the processing capacity requirements.
[0040] The charging flange 12 and the sealing flange 13 are sealed by a sealing ring; the sealing ring is a graphite gasket or a vermiculite gasket; this arrangement ensures the sealing performance of the detonation cylinder 11.
[0041] The remote ignition device 2 can be configured as an electromagnetic ignition device, and the start button of the electromagnetic ignition device is located on the remote controller 4; the ignition time can be determined according to the actual situation.
[0042] This invention also provides a process for producing hard carbon anode materials by detonation, wherein the apparatus for producing hard carbon anode materials by detonation described above performs the following steps:
[0043] S1, after the asphalt or resin-based carbon source is pulverized to 1-3 μm by airflow, it is loaded into the detonation cylinder 11 of the detonation device 1;
[0044] S2, the remote controller 4 closes the regulating valve 10, opens the vacuum valve 9, and starts the vacuum pump 3 to pump the detonation equipment 1 to an absolute pressure of 1-10 kPa.
[0045] S3, the remote controller 4 shuts off the vacuum pump 3 and vacuum valve 9, and opens the regulating valve 10 to introduce detonation gas into the detonation device 1. The detonation gas is obtained by mixing H2 and O2 or C2H2 and O2.
[0046] In this step, the detonation gas can be selected according to the requirements of the finished hard carbon anode material particles and temperature. The ratio of H2 to O2 or the ratio of C2H2 to O2 is determined according to the complete reaction equation. O2 is slightly in excess to facilitate the formation of cross-linked structures and the amount of detonation gas loaded. The amount of detonation gas loaded can be determined according to the pressure detected by the pressure sensor 6 of the detonation device 1. For example, the pressure of the detonation device 1 can be controlled at 140 kPa.
[0047] S4, remote controller 4 closes regulating valve 10, starts remote ignition device 2, ignites detonation gas, and instantly obtains hard carbon anode material.
[0048] In this step, the detonation temperature when the detonation gas is ignited is 1400–2100℃.
[0049] The hard carbon anode material obtained through the above detonation treatment has uniform particle size and internal porosity; the compaction density of this hard carbon anode material is 2-3 g / cm³. 3 The initial efficacy is 85-89%, and the reversible capacity is 330-350 mAh / g.
[0050] Example
[0051] This embodiment adopts Figure 1 , Figure 2 The apparatus shown illustrates the production process of hard carbon anode material via detonation. The specific process is as follows: Isotropic pitch with a softening point of 200–210°C is crushed to D50 = 3.8 μm using an air jet mill, then loaded into the detonation chamber of the detonation equipment and sealed. A remote controller shuts off the vacuum pump and vacuum valve, opens the regulating valve, and introduces detonation gas into the detonation equipment. The detonation gas uses an H2:O2 ratio of 2:1, with a slightly higher O2 content, and the pressure is ultimately controlled at 140 kPa. The remote controller then closes the regulating valve and activates the remote ignition device to ignite the detonation gas, instantly yielding hard carbon anode material after detonation.
[0052] SEM images of the hard carbon anode material prepared in this embodiment are shown below. Figure 3 As shown, the particles are spherical and uniformly distributed. The particle size distribution of this hard carbon anode material is shown in Table 1. The electrochemical performance results are 86% initial efficiency and 335 mAh / g reversible capacity.
[0053] Table 1. Particle size distribution of hard carbon anode materials
[0054]
[0055] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.
Claims
1. An apparatus for producing hard carbon anode materials by detonation, characterized in that, Includes detonation equipment and remote controllers; The detonation device is used to detonate a carbon source; the detonation device includes a detonation cylinder and a vacuum pump and a remote ignition device respectively connected to the detonation cylinder; the detonation cylinder is equipped with a temperature sensor and a pressure sensor; the vacuum pump is connected to the detonation cylinder through a vacuum pipeline, the vacuum pipeline is connected to a vent branch pipe connected to the detonation gas, the vacuum pipeline is equipped with a vacuum valve to control the opening and closing of the pipeline, and the vent branch pipe is equipped with a regulating valve; the remote ignition device ignites the detonation gas inside the detonation cylinder by remote ignition. The remote controller is connected to a vacuum pump, a remote ignition device, a temperature sensor, a pressure sensor, a vacuum valve, and a regulating valve. The remote controller receives the temperature and pressure detected by the temperature and pressure sensors in real time, adjusts the pressure of the detonation equipment through the vacuum pump and vacuum valve, controls the amount of detonation gas loaded through the regulating valve, and controls the remote ignition device to ignite the detonation gas in the detonation equipment, thereby completing the detonation treatment of the carbon source and finally obtaining a hard carbon anode material.
2. The apparatus for producing hard carbon anode materials by detonation method according to claim 1, characterized in that, One side of the detonation tube is provided with a charging slide and a charging flange, and the charging flange is installed on the detonation tube via the charging slide; the other side of the detonation tube is provided with a sealing flange, and the remote ignition device is installed on the sealing flange.
3. The apparatus for producing hard carbon anode materials by detonation method according to claim 2, characterized in that, The detonation cylinder and the loading slide are made of 316L stainless steel.
4. The apparatus for producing hard carbon anode materials by detonation method according to claim 2, characterized in that: The loading flange and the sealing flange are sealed by a sealing ring.
5. The apparatus for producing hard carbon anode materials by detonation method according to claim 4, characterized in that: The sealing ring is a graphite gasket or a vermiculite gasket.
6. The apparatus for producing hard carbon anode materials by detonation method according to claim 1, characterized in that: The remote ignition device is an electromagnetic ignition device, and the start button for the electromagnetic ignition device is located on the remote controller.
7. A process for producing hard carbon anode materials by detonation, characterized in that: The apparatus for producing hard carbon anode materials using the detonation method as described in any one of claims 1 to 6 performs the following steps: S1, after the asphalt or resin-based carbon source is pulverized to 1-3 μm by airflow, it is loaded into the detonation cylinder of the detonation equipment; S2, the remote controller closes the regulating valve, opens the vacuum valve, and starts the vacuum pump to evacuate the detonation equipment to an absolute pressure of 1-10 kPa; S3, the remote controller shuts off the vacuum pump and vacuum valve, opens the regulating valve, and introduces the detonation gas into the detonation equipment. The detonation gas is obtained by mixing H2 and O2 or C2H2 and O2. S4, the remote controller closes the regulating valve, starts the remote ignition device, ignites the detonation gas, and instantly obtains hard carbon anode material.
8. The process for producing hard carbon anode materials by detonation according to claim 7, characterized in that: In step S4, the detonation temperature when the detonation gas is ignited is 1400-2100℃.
9. The process for producing hard carbon anode materials by detonation according to claim 7, characterized in that: The compaction density of the hard carbon anode material is 2-3 g / cm³. 3 The initial efficacy is 85-89%, and the reversible capacity is 330-350 mAh / g.