Preparation method of nanoscale titanium carbide

Abstract

The invention relates to a preparation method of nanoscale titanium carbide, and belongs to the technical field of sodium ion batteries. The preparation method of the nanoscale titanium carbide comprises the following steps that S1, under the protective atmosphere, titanium dioxide, carbon black and an additive are subjected to ball milling through a planetary ball mill, and composite powder is obtained; s2, preheating, carbon thermal reduction and cooling are conducted on the composite powder, and a titanium carbide crude product is obtained through water washing; and S3, carrying out dispersion grading treatment on the titanium carbide crude product, and carrying out centrifugation and drying to obtain the nano-scale titanium carbide. Through a collaborative strategy of mechanical activation pretreatment, low-temperature carbon thermal reduction and spatial confinement growth, the particle size of titanium carbide is effectively regulated and controlled, and meanwhile, the production efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of sodium-ion battery technology, and particularly relates to a method for preparing nanoscale titanium carbide. Background Technology

[0002] In the field of energy storage, sodium-ion batteries, with their advantages of abundant resources and low cost, have become a highly promising rechargeable battery technology, demonstrating broad application potential in large-scale energy storage, electric vehicles, and other areas. In the development of sodium-ion batteries, the performance of the negative electrode material plays a crucial role in the overall performance of the battery, including its energy density, cycle life, and rate capability.

[0003] Titanium carbide (TiC), with its high electrical conductivity, excellent chemical stability, and suitable sodium storage potential, has become one of the most promising anode materials in the field of sodium-ion batteries. However, the practical application and industrial-scale development of titanium carbide materials currently face severe challenges from the preparation process. Existing titanium carbide preparation methods mainly include chemical vapor deposition and mechanical alloying, but these methods have many insurmountable obstacles in achieving mass production.

[0004] While chemical vapor deposition (CVD) can produce high-quality titanium carbide products, its drawbacks are also significant. This method relies on complex and expensive equipment and has extremely demanding reaction conditions, typically requiring reactions to occur under extreme environments such as high temperatures and high vacuum. This not only substantially increases the production cost of titanium carbide but also makes large-scale industrial production difficult due to equipment and reaction condition limitations. Furthermore, CVD has low production efficiency, far from meeting the growing market demand for titanium carbide materials.

[0005] Mechanical alloying involves high-energy ball milling to achieve solid-state alloying between elements in raw material powders such as titanium and carbon sources through collisions, cold welding, and crushing, ultimately producing titanium carbide. However, this method also suffers from a series of serious problems. On the one hand, the powder is prone to agglomeration during ball milling, leading to uneven particle size distribution and severely affecting the stability and consistency of product quality. On the other hand, it typically requires a long milling time and a large energy input, resulting in enormous energy consumption. More importantly, the titanium carbide particles prepared by this method are often large, making it difficult to achieve the fine size requirements at the nanometer level. Nanoscale titanium carbide can more fully leverage its performance advantages in sodium-ion batteries, and excessively large particle sizes significantly limit further improvements in titanium carbide performance.

[0006] Therefore, developing a new method to prepare high-performance titanium carbide remains a key technical challenge that urgently needs to be addressed in the field of sodium-ion batteries. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a method for preparing nanoscale titanium carbide. Through a synergistic strategy of mechanical activation pretreatment, low-temperature carbothermal reduction, and spatially confined growth, the particle size of titanium carbide can be effectively controlled, while simultaneously improving production efficiency.

[0008] The purpose of this invention is to provide a method for preparing nano-sized titanium carbide, comprising the following steps:

[0009] S1. Under a protective atmosphere, titanium dioxide, carbon black and additives are ball-milled using a planetary ball mill to obtain composite powder;

[0010] S2. The composite powder described in S1 is preheated, carbotherm reduced and cooled, and then washed with water to obtain crude titanium carbide product.

[0011] S3. The crude titanium carbide product described in S2 is dispersed and classified, and then centrifuged and dried to obtain the nano-sized titanium carbide.

[0012] In one embodiment of the present invention, in S1, the titanium dioxide has a purity ≥99.5% and an average particle size ≤1μm;

[0013] The specific surface area of ​​the carbon black is 100 m². 2 / g-300m 2 / g, with a particle size of 20nm-50nm; limiting the particle size of titanium dioxide and carbon black can improve the driving force of the reaction, otherwise the reaction will be incomplete;

[0014] The additive is selected from sodium chloride (NaCl) and / or potassium chloride (KCl). During the subsequent carbothermic reduction process, the additive melts to form a liquid phase and is uniformly dispersed in the reaction system. This state effectively isolates the titanium carbide grains, thereby limiting their excessive growth. In addition, the additive also acts as a steric confinement agent, precisely controlling the material particle size to maintain it stably at the nanoscale, thus achieving precise control over the material size.

[0015] In one embodiment of the present invention, in S1, the molar ratio of titanium dioxide to carbon black is 1:(1.01-1.1);

[0016] The amount of the additive is 0.5wt%-2wt% of the total amount of titanium dioxide and carbon black.

[0017] In one embodiment of the present invention, in step S1, the ball-to-material ratio of the ball mill is 20:1, the rotation speed is 400-500 rpm, and the time is 8-12 hours. During the ball milling process, the mechanical force promotes the close contact between titanium dioxide and carbon black, thereby triggering mechanochemical reactions that bind the two together into a tight composite. Simultaneously, it induces lattice distortion in titanium dioxide, a change that significantly enhances the reactivity of the raw material. This step not only successfully achieves nano-scale processing of the raw material but also lowers the activation energy of the subsequent carbothermic reduction reaction by increasing the raw material's reactivity, laying a solid foundation for the smooth progress of the reaction.

[0018] In one embodiment of the present invention, in S1, the specific surface area of ​​the composite powder is ≥80m². 2 / g.

[0019] In one embodiment of the present invention, in S2, the preheating temperature is 800℃-1000℃ and the time is 20min-80min; during this stage, the adsorbed gas in the composite powder is removed and the mechanical stress is eliminated.

[0020] In one embodiment of the present invention, in S2, the carbothermic reduction temperature is 1300℃-1400℃, and the time is 30min-60min; during this stage, titanium dioxide and carbon black undergo a carbothermic reduction reaction to generate titanium carbide. Thanks to the mechanical activation pretreatment during ball milling, the reaction temperature is reduced by 200℃ compared to conventional processes, effectively suppressing grain growth; simultaneously, the improved reaction kinetics brought about by the mechanical activation pretreatment significantly shortens the holding time, thereby significantly improving production efficiency while ensuring the reaction proceeds fully.

[0021] In one embodiment of the present invention, in S2, the cooling is first performed under an argon atmosphere, cooling to 400°C-800°C at a rate of 10°C / min-20°C / min, and then air-cooling to room temperature; during this stage, the Ostwald curing phenomenon is prevented, thereby preserving the nanostructure of the material.

[0022] In one embodiment of the present invention, in S2, the water washing can remove the additives. Since the additives NaCl or KCl have good solubility in water, they can be easily removed (recovery rate > 99%) without causing pollution to the material.

[0023] In one embodiment of the present invention, in step S3, the dispersion and classification treatment involves adding the material to a 5wt%-8wt% citric acid solution and stirring at 250rpm-350rpm at 80℃-105℃ for 1h-3h. During this process, the citric acid solution removes free carbon from the material surface and introduces carboxylic acid functional groups onto its surface, thereby significantly improving the dispersibility and uniformity of the material.

[0024] In one embodiment of the present invention, the equipment for dispersion and classification is a centrifugal classifier, and the atmosphere is a protective atmosphere; nano-sized particles are collected by separating and removing undispersed agglomerated particles.

[0025] In the dispersion and fractionation process, the mass ratio of citric acid solution to crude titanium carbide product is (9-11):1.

[0026] The technical solution of the present invention has the following advantages compared with the prior art:

[0027] (1) The preparation method described in this invention introduces a mechanical activation pretreatment step before the carbothermic reduction reaction. This mechanical energy reduces the activation energy of subsequent reactions, causing the carbothermic reduction temperature to decrease by 150℃-200℃. This significant decrease in carbothermic reduction temperature not only substantially reduces energy consumption during production, becoming a crucial breakthrough in reducing production costs—especially in large-scale production scenarios, where energy cost reduction directly translates into improved economic benefits for enterprises. Simultaneously, the improved reaction kinetics resulting from mechanical activation also significantly shortens the holding time. This change not only improves production efficiency but also further reduces overall production costs from a time cost perspective. Through the dual effects of energy saving and efficiency improvement, this preparation process achieves a significant cost advantage in market competition, highlighting its stronger competitiveness.

[0028] (2) In the preparation method described in this invention, the NaCl or KCl added during ball milling melts to form a liquid phase and is uniformly dispersed in the reaction system during subsequent carbothermic reduction, thereby effectively isolating the titanium carbide grains and limiting their excessive growth. Furthermore, these additives can be efficiently removed by washing with water after the reaction, with a recovery rate exceeding 99%. This characteristic not only reduces waste generation and environmental impact but also enables resource recycling.

[0029] (3) The preparation method described in this invention retains the scalability compatibility of the carbothermal reduction method, and makes the entire process more suitable for large-scale industrial production by adjusting and optimizing each preparation step. From raw material pretreatment to post-treatment optimization, each step is carefully designed and strictly controlled, which provides a reliable guarantee for the stability and consistency of titanium carbide quality.

[0030] (4) The preparation method described in this invention can prepare nano-sized titanium carbide. On the one hand, nano-sized titanium carbide eliminates the tedious secondary crushing step, directly improving production efficiency; on the other hand, nano-sized titanium carbide has a larger specific surface area and higher reactivity, which allows it to participate more fully in the electrochemical reaction in sodium-ion batteries, thereby comprehensively improving the battery's charge-discharge performance, cycle stability, and rate performance.

[0031] (5) The preparation method described in this invention not only excels in energy saving and consumption reduction, but also improves the performance of titanium carbide, while possessing good mass production adaptability and environmental friendliness. Detailed Implementation

[0032] The present invention will be further described below with reference to specific embodiments, so that those skilled in the art can better understand and implement the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. It should be understood that the specific embodiments are only used to explain the present invention, but the embodiments are not intended to limit the present invention.

[0033] In this invention, unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0034] In this invention, unless otherwise stated, the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] In this invention, unless otherwise specified, the experimental methods used in the embodiments of this invention are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0036] In this invention, unless otherwise stated, the titanium dioxide powder used in the embodiments of this invention has a purity of 99.9% and an average particle size of ≤1μm.

[0037] In this invention, unless otherwise stated, the specific surface area of ​​the nano-carbon black used in the embodiments of this invention is 100 m². 2 / g-300m 2 / g, particle size 20nm-50nm.

[0038] Example 1

[0039] The preparation method of nanoscale titanium carbide in this embodiment specifically includes the following steps:

[0040] S1. Titanium dioxide powder and nano carbon black (molar ratio of titanium dioxide powder and nano carbon black is 1:1.05) and sodium chloride accounting for 1 wt% of the total amount of the two are added together into a WC cemented carbide can. Then the can is placed in a planetary ball mill and argon gas is introduced into the can to create an inert protective atmosphere. The ball-to-material ratio of the planetary ball mill is set to 20:1, the ball milling speed is 450 rpm, and the ball milling time is 10 h. The composite powder is obtained by ball milling.

[0041] S2. The composite powder is transferred to a tube furnace, heated to 900°C and held for 50 min, then heated to 1350°C and carbothermally reduced for 45 min. The material is then quickly transferred to a cooling zone and cooled to 500°C at a rate of 15°C / min under an argon atmosphere. It is then air-cooled to room temperature and washed with water to obtain crude titanium carbide.

[0042] S3. Under a nitrogen atmosphere, the crude titanium carbide product was dispersed and classified using a centrifugal classifier. The crude titanium carbide product was added to a 6.5 wt% citric acid solution and stirred at 300 rpm at 90°C for 1.5 h. The mass ratio of citric acid solution to crude titanium carbide product was 10:1. The supernatant was then taken and centrifuged at 8000 rpm for 20 min. The precipitate was collected and dried to obtain nano-sized titanium carbide.

[0043] Comparative Example 1

[0044] The process is basically the same as in Example 1, except that sodium chloride is not added during the ball milling process. Specifically, it includes the following steps:

[0045] S1. Titanium dioxide powder and nano carbon black (molar ratio of titanium dioxide powder to nano carbon black is 1:1.05) are added together into a WC cemented carbide can. The can is then placed in a planetary ball mill, and argon gas is introduced into the can to create an inert protective atmosphere. The ball-to-material ratio of the planetary ball mill is set to 20:1, the ball milling speed is 450 rpm, and the ball milling time is 10 h. The composite powder is obtained by ball milling.

[0046] S2. The composite powder is transferred to a tube furnace, heated to 900°C and held for 50 min, then heated to 1350°C and carbothermally reduced for 45 min. The material is then quickly transferred to a cooling zone and cooled to 500°C at a rate of 15°C / min under an argon atmosphere. It is then air-cooled to room temperature and washed with water to obtain crude titanium carbide.

[0047] S3. Under a nitrogen atmosphere, the crude titanium carbide product was dispersed and classified using a centrifugal classifier. The crude titanium carbide product was added to a 6.5 wt% citric acid solution and stirred at 300 rpm at 90°C for 1.5 h. The mass ratio of citric acid solution to crude titanium carbide product was 10:1. The supernatant was then taken and centrifuged at 8000 rpm for 20 min. The precipitate was collected and dried to obtain nano-sized titanium carbide.

[0048] Comparative Example 2

[0049] The process is basically the same as in Example 1, except that mechanical ball milling is not used. Specifically, it includes the following steps:

[0050] S1. Add titanium dioxide powder and nano carbon black (molar ratio of titanium dioxide powder and nano carbon black is 1:1.05) and sodium chloride accounting for 1 wt% of the total amount of the two into a WC cemented carbide can and mix evenly to obtain composite powder.

[0051] S2. The composite powder is transferred to a tube furnace, heated to 900°C and held for 50 min, then heated to 1350°C and carbothermally reduced for 45 min. The material is then quickly transferred to a cooling zone and cooled to 500°C at a rate of 15°C / min under an argon atmosphere. It is then air-cooled to room temperature and washed with water to obtain crude titanium carbide.

[0052] S3. Under a nitrogen atmosphere, the crude titanium carbide product was dispersed and classified using a centrifugal classifier. The crude titanium carbide product was added to a 6.5 wt% citric acid solution and stirred at 300 rpm at 90°C for 1.5 h. The mass ratio of citric acid solution to crude titanium carbide product was 10:1. The supernatant was then taken and centrifuged at 8000 rpm for 20 min. The precipitate was collected and dried to obtain nano-sized titanium carbide.

[0053] Comparative Example 3

[0054] Basically the same as Example 1, except that the staged carbothermal reduction is not performed. Specifically, it includes the following steps:

[0055] S1. Titanium dioxide powder and nano carbon black (molar ratio of titanium dioxide powder and nano carbon black is 1:1.05) and sodium chloride accounting for 1 wt% of the total amount of the two are added together into a WC cemented carbide can. Then the can is placed in a planetary ball mill and argon gas is introduced into the can to create an inert protective atmosphere. The ball-to-material ratio of the planetary ball mill is set to 20:1, the ball milling speed is 450 rpm, and the ball milling time is 10 h. The composite powder is obtained by ball milling.

[0056] S2. The composite powder is transferred to a tube furnace, heated to 1350℃ and carbothermally reduced for 85 min. Then the material is quickly transferred to a cooling zone and cooled to 500℃ at a rate of 15℃ / min under an argon atmosphere. Then it is air-cooled to room temperature and washed with water to obtain crude titanium carbide product.

[0057] S3. Under a nitrogen atmosphere, the crude titanium carbide product was dispersed and classified using a centrifugal classifier. The crude titanium carbide product was added to a 6.5 wt% citric acid solution and stirred at 300 rpm at 90°C for 1.5 h. The mass ratio of citric acid solution to crude titanium carbide product was 10:1. The supernatant was then taken and centrifuged at 8000 rpm for 20 min. The precipitate was collected and dried to obtain nano-sized titanium carbide.

[0058] Comparative Example 4

[0059] The process is basically the same as in Example 1, except that argon cooling is not performed. The specific steps include:

[0060] S1. Titanium dioxide powder and nano carbon black (molar ratio of titanium dioxide powder and nano carbon black is 1:1.05) and sodium chloride accounting for 1 wt% of the total amount of the two are added together into a WC cemented carbide can. Then the can is placed in a planetary ball mill and argon gas is introduced into the can to create an inert protective atmosphere. The ball-to-material ratio of the planetary ball mill is set to 20:1, the ball milling speed is 450 rpm, and the ball milling time is 10 h. The composite powder is obtained by ball milling.

[0061] S2. The composite powder is transferred to a tube furnace, heated to 900°C and held for 50 min, then heated to 1350°C and carbothermally reduced for 45 min, then air-cooled to room temperature, and washed with water to obtain crude titanium carbide product.

[0062] S3. Under a nitrogen atmosphere, the crude titanium carbide product was dispersed and classified using a centrifugal classifier. The crude titanium carbide product was added to a 6.5 wt% citric acid solution and stirred at 300 rpm at 90°C for 1.5 h. The mass ratio of citric acid solution to crude titanium carbide product was 10:1. The supernatant was then taken and centrifuged at 8000 rpm for 20 min. The precipitate was collected and dried to obtain nano-sized titanium carbide.

[0063] Comparative Example 5

[0064] The process is basically the same as in Example 1, except that citric acid solution is not used for dispersion and fractionation. Specifically, it includes the following steps:

[0065] S1. Titanium dioxide powder and nano carbon black (molar ratio of titanium dioxide powder and nano carbon black is 1:1.05) and sodium chloride accounting for 1 wt% of the total amount of the two are added together into a WC cemented carbide can. Then the can is placed in a planetary ball mill and argon gas is introduced into the can to create an inert protective atmosphere. The ball-to-material ratio of the planetary ball mill is set to 20:1, the ball milling speed is 450 rpm, and the ball milling time is 10 h. The composite powder is obtained by ball milling.

[0066] S2. The composite powder is transferred to a tube furnace, heated to 900℃ and held for 50 min, then heated to 1350℃ and carbothermally reduced for 45 min. The material is then quickly transferred to a cooling zone and cooled to 500℃ at a rate of 15℃ / min under an argon atmosphere. It is then air-cooled to room temperature, washed with water and dried to obtain nano-sized titanium carbide.

[0067] Test Example 1

[0068] (1) Based on Example 1 and Comparative Examples 1-5, the specific surface area of ​​the composite powder and the particle size of nano-sized titanium carbide were tested:

[0069] Specific surface area test: The specific surface area was obtained by nitrogen adsorption-desorption BET method (Brunauer-Emmett-Teller);

[0070] Particle size testing: Particle size was obtained using a Malvern Mastersizer 3000 particle size analyzer.

[0071] (2) Battery assembly:

[0072] Negative electrode: The negative electrode active material is nano-sized titanium carbide prepared in Examples 1 and 1-5, respectively; the conductive agent is acetylene black; the binder is polyvinylidene fluoride; and the negative electrode current collector is 6μm aluminum foil. The negative electrode active material, conductive agent, and binder are mixed at a mass ratio of 8:1:1, and N-methylpyrrolidone is added and stirred to form a uniform and stable negative electrode slurry. The negative electrode slurry is uniformly coated onto the surface of the negative electrode current collector using a 200μm doctor blade coating. After drying and cold pressing, a mass load of approximately 2.5 mg / cm³ is obtained. 2 The negative electrode plate.

[0073] Counter electrode: Sodium metal sheet.

[0074] Separating membrane: Polyethylene film, 9μm thick.

[0075] Electrolyte: Sodium hexafluorophosphate is dissolved in polycarbonate to prepare an electrolyte with a concentration of 1 mol / L.

[0076] Sodium-ion battery assembly: Arrange the negative electrode, separator, counter electrode, and separator in sequence to assemble a CR2032 coin cell sodium-ion battery.

[0077] Performance testing:

[0078] First coulombic efficiency test: The CR2032 coin cell sodium-ion battery to be formed was left to stand at 60℃ for 40 min, then charged at a rate of 0.1C to the upper limit of the activation voltage, and then discharged to the lower limit of the activation voltage. The first coulombic efficiency was measured. The first coulombic efficiency is the ratio of the first discharge capacity to the first charge capacity.

[0079] Cycle stability testing began with a 0.1C capacity calibration, where the discharge capacity was recorded as C0. Then, a 10C charge-discharge cycle was performed (charged to 3.9V, discharged to 1.5V). A 0.1C capacity calibration was performed every 1000 cycles, and the capacity retention rate after the 1000th cycle was recorded. The discharge capacity C10 from the 10th 0.1C capacity calibration was used to evaluate the sodium-ion battery's cycle stability over 8000 cycles. The capacity retention rate R = C10 / C0 * 100% was used to assess this stability.

[0080] Table 1 shows the relevant test results:

[0081] Table 1

[0082]

[0083]

[0084] As shown in Table 1, the sodium-ion battery prepared with nanoscale titanium carbide in the examples exhibits excellent initial charge-discharge efficiency and capacity retention. This is because the examples, through the synergistic use of mechanical activation pretreatment, NaCl spatial confinement agent addition, and stepwise sintering processes, significantly improved the reactivity of the raw materials while effectively suppressing particle growth, thus ensuring that the particle size of the nanoscale titanium carbide was stably controlled within the range of 50nm-100nm. This series of process optimizations resulted in significant performance improvements, fully demonstrating that the synergistic effect of the three processes can greatly enhance the electrochemical performance of titanium carbide anode in sodium-ion batteries.

[0085] Comparing Example 1 and Comparative Example 1, it can be seen that when ball milling was performed without the addition of sodium chloride, the nano-sized titanium carbide particles were larger. This increased particle size directly led to a decrease in the initial charge-discharge efficiency and cycle stability of the battery. This is because, without the addition of sodium chloride, the lack of spatial confinement effectively constrains particle growth, resulting in a significant increase in product particle size. This also demonstrates the significant effect of spatial confinement agents such as sodium chloride in particle size control, which can inhibit excessive particle growth and play a crucial role in improving the electrochemical performance of the sodium-ion battery anode.

[0086] Comparing Example 1 and Comparative Example 2, it can be seen that when titanium dioxide powder and nano-carbon black are mixed using only a simple method, the nano-sized titanium carbide particles are large. This large particle size directly leads to a significant decrease in both the initial charge-discharge efficiency and the capacity retention rate after 8000 cycles. This is because the contact area between the titanium dioxide powder and nano-carbon black mixed using the simple method is small, hindering diffusion at the reaction interface and resulting in large titanium carbide grains. Furthermore, the unactivated raw materials cannot form a stable SEI film, further affecting battery performance.

[0087] Comparing Example 1 and Comparative Example 3, it can be seen that when the reaction temperature is directly raised to 1400℃, the nano-sized titanium carbide particles are larger. The increased particle size directly leads to a decrease in the first charge-discharge efficiency and a decline in cycle stability of the battery. This is because without preheating treatment, mechanical stress cannot be eliminated, resulting in local sintering and agglomeration, producing coarse products, which in turn affects battery performance.

[0088] Comparing Example 1 and Comparative Example 4, it can be seen that without argon cooling, the nano-sized titanium carbide particles are larger. This increased particle size directly leads to a decrease in both the initial charge-discharge efficiency and the capacity retention rate after 8000 cycles. This is because air cooling (slow cooling) induces Ostwald curing, increasing particle coarsening and thus affecting battery performance.

[0089] Comparing Example 1 and Comparative Example 5, it can be seen that the powder without citric acid dispersion and classification treatment has an increased particle size. This is because citric acid dispersion and classification treatment can remove free carbon on the surface and introduce carboxylic acid groups, which significantly improves the dispersibility of the product. However, the added free carbon induces sodium dendrite growth, and the oxygen-containing functional groups (C=O, -OH) on the surface undergo nucleophilic reactions with the electrolyte, consuming active sodium ions and reducing specific capacity and cycle performance.

[0090] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing nanoscale titanium carbide, characterized in that, Includes the following steps: S1. Under a protective atmosphere, titanium dioxide, carbon black and additives are ball-milled using a planetary ball mill to obtain composite powder; S2. The composite powder described in S1 is preheated, carbotherm reduced and cooled, and then washed with water to obtain crude titanium carbide product. S3. The crude titanium carbide product described in S2 is dispersed and classified, and then centrifuged and dried to obtain the nano-sized titanium carbide.

2. The method for preparing nanoscale titanium carbide according to claim 1, characterized in that, In S1, the titanium dioxide has a purity of ≥99.5% and an average particle size of ≤1μm; The specific surface area of ​​the carbon black is 100 m². 2 / g-300m 2 / g, with a particle size of 20nm-50nm; The additive is selected from sodium chloride and / or potassium chloride.

3. The method for preparing nanoscale titanium carbide according to claim 1, characterized in that, In S1, the molar ratio of titanium dioxide to carbon black is 1:(1.01-1.1); The amount of the additive is 0.5wt%-2wt% of the total amount of titanium dioxide and carbon black.

4. The method for preparing nanoscale titanium carbide according to claim 1, characterized in that, In S1, the ball-to-material ratio of the ball mill is 20:1, the rotation speed is 400rpm-500rpm, and the time is 8h-12h.

5. The method for preparing nanoscale titanium carbide according to claim 1, characterized in that, In S1, the specific surface area of ​​the composite powder is ≥80m². 2 / g.

6. The method for preparing nanoscale titanium carbide according to claim 1, characterized in that, In S2, the preheating temperature is 800℃-1000℃ and the time is 20min-80min.

7. The method for preparing nanoscale titanium carbide according to claim 1, characterized in that, In S2, the carbothermic reduction temperature is 1300℃-1400℃ and the time is 30min-60min.

8. The method for preparing nanoscale titanium carbide according to claim 1, characterized in that, In S2, the cooling is first performed under an argon atmosphere, cooling down to 400°C-800°C at a rate of 10°C / min-20°C / min, and then air-cooling to room temperature.

9. The method for preparing nanoscale titanium carbide according to claim 1, characterized in that, In S3, the dispersion and classification process involves adding the material to a 5wt%-8wt% citric acid solution and stirring it at 250rpm-350rpm at 80℃-105℃ for 1h-3h.

10. The method for preparing nanoscale titanium carbide according to claim 9, characterized in that, The equipment for the dispersion and grading process is a centrifugal classifier, and the atmosphere is a protective atmosphere. In the dispersion and fractionation process, the mass ratio of citric acid solution to crude titanium carbide product is (9-11):1.

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