Antimony-based composite negative electrode material, and preparation method and application thereof

Abstract

The application provides an antimony-based composite negative electrode material and a preparation method and application thereof, and relates to the technical field of new energy batteries.The preparation method provided by the application comprises the following steps: mixing antimony metal powder with amorphous carbon, ball-milling, drying and calcining to obtain an antimony-based intermediate; performing acidification treatment on the surface of carbon nanotubes to obtain acidified carbon nanotubes, dispersing the acidified carbon nanotubes in an organic sodium modified solution, stirring, filtering, drying to obtain modified carbon nanotubes; mixing and dispersing the antimony-based intermediate, sodium polyacrylate and the modified carbon nanotubes to obtain a suspension, and then performing spray drying to obtain the antimony-based composite negative electrode material.The preparation method provided by the application can improve the problem of performance decline caused by the capacity attenuation of the antimony metal due to the huge volume expansion in the process of deintercalating sodium ions, and effectively improves the electrochemical performance of the antimony-based negative electrode material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy battery, in particular to a Sb-based composite negative electrode material and a preparation method and application thereof. BACKGROUND

[0002] The development of renewable energy and the development of energy storage technology are particularly important, among which lithium batteries have excellent electrochemical performance, high energy density and green environmental protection, and have become the research focus of current energy storage technology. At present, lithium ion batteries are widely used in portable electronic devices, and with the large-scale development and application of electric vehicles and portable electronic devices, the limited lithium resources on earth will lead to the increase of the cost of lithium ion batteries, so the sodium ion secondary battery with similar electrochemical performance and lithium ion battery properties becomes the most suitable alternative. Sodium ion battery uses single element or compound that can reversibly insert and extract sodium ions as positive and negative electrodes, and sodium element is easy to obtain and has higher half-cell potential, so sodium ion battery can use low decomposition voltage electrolyte, and its safety is better than that of lithium ion battery.

[0003] However, due to the larger radius of sodium ions, when the interlayer spacing of the negative electrode is smaller than the diameter of the sodium ions, it is difficult for the sodium ions to be inserted into the negative electrode material, resulting in a very small amount of sodium ion insertion, and thus the specific capacity of the sodium ion battery is low. Since metallic antimony (Sb) can alloy with sodium ions, the amount of sodium ion insertion is increased, thereby increasing the theoretical specific capacity of the sodium ion battery. However, metallic antimony undergoes a large volume change during sodiumization and desodiumization, which may even cause the electrode to break and powder, resulting in a rapid decrease in the electrochemical performance of the sodium ion battery, leading to a serious decrease in capacity and a decrease in cycle stability. Therefore, there is an urgent need to provide a solution to improve the above problems. SUMMARY

[0004] The purpose of the present application is to provide a Sb-based composite negative electrode material and a preparation method and application thereof, which can improve the capacity attenuation and other performance degradation problems caused by the large volume expansion of metallic antimony during sodium ion extraction, and effectively improve the electrochemical performance of the Sb-based negative electrode material.

[0005] In a first aspect, the present application provides a preparation method of a Sb-based composite negative electrode material, comprising the following steps:

[0006] Mixing and ball-milling the antimony metal powder and the amorphous carbon precursor, drying and calcining to obtain a Sb-based intermediate;

[0007] Surface acidification treatment is performed on the carbon nanotubes to obtain acidified carbon nanotubes, and the acidified carbon nanotubes are dispersed in an organic sodium modified solution, stirred, filtered and dried to obtain modified carbon nanotubes;

[0008] The antimony-based intermediate, sodium polyacrylate and modified carbon nanotubes are mixed and dispersed to prepare a suspension, and then spray drying is performed to prepare the antimony-based composite negative electrode material.

[0009] The preparation method of the antimony-based composite negative electrode material provided by the application can effectively reduce the particle size of the antimony metal powder after ball milling of the antimony metal powder and the amorphous carbon precursor, and can better uniformly composite the amorphous carbon precursor in the subsequent process, thereby effectively inhibiting the volume expansion of the metal antimony.

[0010] Meanwhile, the modified carbon nanotubes are beneficial to the mutual crosslinking between the carbon nanotubes, and can also improve the anchoring capacity of the antimony metal powder, the addition of organic sodium in the carbon nanotubes can improve the capacity and service life of the sodium ion battery, and the use of the spray drying technology is beneficial to the formation of a three-dimensional conductive network of the modified carbon nanotubes and the locking of the antimony-based intermediate in the three-dimensional conductive network, which can further inhibit the volume expansion of the metal antimony and improve the overall conductive performance and structural stability of the negative electrode material, thereby improving the electrochemical performance of the antimony-based composite negative electrode material.

[0011] The organic sodium can form an organic SEI film in the negative electrode material, which has stronger ductility and weaker rigidity, so that the SEI film is not easy to break during the use of the negative electrode material, and the negative electrode material can be better protected, and the spray drying of the antimony-based intermediate and the modified carbon nanotubes can avoid damaging the carbon structure coated on the surface of the antimony-based intermediate.

[0012] Optionally, during the ball milling of the antimony metal powder and the amorphous carbon precursor, the mass ratio of the antimony metal powder to the amorphous carbon precursor is 0.5-1.

[0013] Optionally, during the ball milling of the antimony metal powder and the amorphous carbon precursor, the ball-to-material ratio is 10-20.

[0014] Optionally, during the preparation of the antimony-based intermediate by drying and calcining after the ball milling of the antimony metal powder and the amorphous carbon precursor, the process comprises: after the ball milling of the antimony metal powder and the amorphous carbon precursor, the antimony-based intermediate is prepared by suction filtration and drying of the antimony-based precursor; and the antimony-based precursor is calcined at 1000-1300 DEG C in an inert atmosphere for 2-4 h to prepare the antimony-based intermediate.

[0015] Optionally, during the preparation of the antimony-based precursor by suction filtration and drying after the ball milling of the antimony metal powder and the amorphous carbon precursor, the process comprises: after the ball milling of the antimony metal powder and the amorphous carbon precursor, the antimony-based precursor is prepared by suction filtration and drying of the suction filtration product at 50-80 DEG C for 10-14 h.

[0016] Optionally, when the antimony-based intermediate is mixed and dispersed with the modified carbon nanotubes to prepare a suspension, a solid-liquid ratio of the suspension is 0.03-0.06.

[0017] Optionally, in the process of preparing the acidified carbon nanotubes by surface acidification treatment of the carbon nanotubes, the acidified carbon nanotubes are prepared by immersing the carbon nanotubes in nitric acid, and then performing suction filtration and drying.

[0018] Optionally, in the process of preparing the acidified carbon nanotubes by surface acidification treatment of the carbon nanotubes, the acidified carbon nanotubes are prepared by immersing the carbon nanotubes in nitric acid for 20-30 hours, washing the suction filtration product with deionized water, and then drying at 50-80°C for 10-14 hours.

[0019] Optionally, in the process of dispersing the acidified carbon nanotubes in the organic sodium modified solution, stirring, and drying by filtration, the acidified carbon nanotubes are stirred and dried by filtration in a siloxane solution to prepare activated carbon nanotubes; and the activated carbon nanotubes are dispersed in the organic sodium modified solution, stirred for 5-6 hours at 50-60°C, and then dried by filtration. By pre-activating the acidified carbon nanotubes in the siloxane solution, the subsequent modification reaction between the acidified carbon nanotubes and the organic sodium modified solution and the anchoring of the antimony metal powder are facilitated.

[0020] Optionally, when the acidified carbon nanotubes are stirred and filtered in the siloxane solution, a solute of the siloxane solution includes at least one of γ-aminopropyltrimethoxysilane and γ-glycidyl ether propyltrimethoxysilane.

[0021] Optionally, in the process of dispersing the acidified carbon nanotubes in the organic sodium modified solution, stirring, and drying by filtration, a solute of the organic sodium modified solution includes at least one of ethylenediaminetetraacetic acid disodium salt and cyanuric acid trisodium.

[0022] In a second aspect, the present application further provides the antimony-based composite negative electrode material prepared by any of the optional preparation methods described above.

[0023] In a third aspect, the present application further provides the use of the antimony-based composite negative electrode material prepared by any of the optional preparation methods described above in a sodium ion battery. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A flow chart of a preparation method of an antimony-based composite negative electrode material is provided for an embodiment of the present application;

[0025] Figure 2 A structural schematic diagram of an antimony-based composite negative electrode material is provided for an embodiment of the present application;

[0026] Figure 3Cycling performance chart of the present application embodiment 1 to embodiment 3, comparative example 1 to comparative example 7. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meaning understood by those skilled in the art.

[0028] Reference Figure 1 The present application embodiment provides a preparation method of antimony-based composite negative electrode material, comprising the following steps:

[0029] S1, preparing an antimony-based intermediate: mixing antimony metal powder and amorphous carbon precursor, ball milling, drying and calcining to obtain an antimony-based intermediate;

[0030] S2, preparing modified carbon nanotubes: performing surface acidification treatment on carbon nanotubes to obtain acidified carbon nanotubes, dispersing the acidified carbon nanotubes in an organic sodium modified solution, stirring, filtering and drying to obtain modified carbon nanotubes;

[0031] S3, preparing an antimony-based composite negative electrode material: mixing and dispersing the antimony-based intermediate, sodium polyacrylate and modified carbon nanotubes to obtain a suspension, and then spray drying to obtain an antimony-based composite negative electrode material.

[0032] In some embodiments, the antimony metal powder used in step S1 is micron-sized powder. Specifically, the micron-sized antimony metal powder has a particle size of 1-20 μm, and the purity of the metal antimony in the antimony metal powder is greater than or equal to 99%. In fact, the antimony metal powder can be selected from commercially available conventional products, such as spherical antimony powder with a particle size of 1-20 μm produced by Tianjin Lizite Science and Technology Co., Ltd.

[0033] In some embodiments, the amorphous carbon precursor used in step S1 includes at least one of oil-based phenolic resin and pitch. Specifically, both the oil-soluble phenolic resin and the pitch can be commercially available products or recycled waste. When the oil-based phenolic resin is a commercially available product, it can be oil-soluble phenolic resin with a molecular weight of 80,000-100,000 purchased from Shaoxing Yitong Plastic Co., Ltd. When the pitch is a commercially available product, it can be coal tar pitch powder with a particle size of 1-3 mm purchased from Han Kai Energy.

[0034] In fact, in the process of performing step S1, the following sub-steps are included:

[0035] S1.1, mixing antimony metal powder with amorphous carbon precursor, then wet ball milling, and drying by suction filtration to obtain an antimony-based precursor;

[0036] S1.2, calcining the antimony-based precursor in an inert atmosphere at 1000-1300℃ for 2-4h to obtain an antimony-based intermediate.

[0037] In some embodiments, in the process of performing step S1.1, the mass ratio of the antimony metal powder to the amorphous carbon precursor is 0.5-1, and the ball-to-material ratio of the ball milling is 10-20.

[0038] In some embodiments, in the process of performing step S1.1, after mixing and ball milling the antimony metal powder with the amorphous carbon precursor, the solid obtained by suction filtration is dried at 50-80℃ for 10-14h to obtain the antimony-based precursor.

[0039] In some embodiments, in the process of performing step S1.2, the antimony-based precursor is first placed in an inert atmosphere environment, and the antimony-based precursor is gradually heated from room temperature to 1000-1300℃, and the antimony-based intermediate is obtained after calcining at 1000-1300℃ for 2-4h. Specifically, the inert atmosphere environment can be an atmosphere furnace, and the inert atmosphere used can be an argon atmosphere, and the heating rate can be 2-10℃ / min.

[0040] In some embodiments, in the process of performing step S2 to obtain acidified carbon nanotubes, the carbon nanotubes are soaked in nitric acid, then dried by suction filtration to obtain acidified carbon nanotubes. In practice, the concentration of the nitric acid used is in the range of 70-80%, and the carbon nanotubes used can be at least one of single-walled carbon nanotubes and multi-walled carbon nanotubes.

[0041] Specifically, in the process of performing step S2 to obtain acidified carbon nanotubes, the carbon nanotubes are soaked in nitric acid for 20-30h, then washed repeatedly with deionized water, and the washed product is dried at 50-80℃ for 10-14h to obtain acidified carbon nanotubes.

[0042] In some embodiments, in the process of performing step S2 to obtain modified carbon nanotubes, the process includes:

[0043] After stirring and filtering the acidified carbon nanotubes in a siloxane solution and drying, activated carbon nanotubes are obtained;

[0044] The activated carbon nanotubes are dispersed in an organic sodium modified solution, stirred and dispersed at 50-60℃ for 5-6h, then dried by suction filtration to obtain modified carbon nanotubes.

[0045] In fact, when the acidified carbon nanotubes are stirred and filtered dry in the silicone solution, the solute of the silicone solution used includes at least one of γ-aminopropyltrimethoxysilane (γ-APS) and γ-glycidyl ether propyltrimethoxysilane (KH560).

[0046] Specifically, when the acidified carbon nanotubes are stirred and filtered dry in the silicone solution, the solid-liquid ratio of the acidified carbon nanotubes to the silicone solution is 0.05-0.07, and the solute concentration in the silicone solution is 80-90% of the saturation concentration.

[0047] In fact, when the activated carbon nanotubes are dispersed in the organic sodium modified solution, the solute of the organic sodium modified solution used includes at least one of disodium ethylenediaminetetraacetate and trisodium cyanurate, and the solid-liquid ratio of the activated carbon nanotubes to the organic sodium modified solution is 0.05-0.08, and the solute concentration in the organic sodium modified solution is 70-90% of the saturation concentration.

[0048] In some embodiments, when the step S3 is performed, the suspension is prepared by dispersing the antimony-based intermediate, sodium polyacrylate, and modified carbon nanotubes, the liquid environment used in the suspension is deionized water, and the solid-liquid ratio of the suspension is 0.03-0.06.

[0049] Referring to Figure 2 The present application also provides the antimony-based composite negative electrode material prepared by any of the above embodiments, the antimony metal powder 1 is adsorbed on the surface defect position of the amorphous carbon 2, and after the composite modified carbon nanotube 3, the three-dimensional conductive network formed by the modified carbon nanotube 3 is wrapped in the outermost layer of the antimony metal powder 1 and the amorphous carbon 2. The carbon skeleton formed by the amorphous carbon 2 and the three-dimensional conductive network formed by the modified carbon nanotube are interwoven, and the antimony-based metal powder 1 is locked in the skeleton gap, thereby effectively inhibiting the antimony-based expansion effect of the antimony metal powder 1 in the process of deintercalating sodium ions, and improving the overall conductivity and electrochemical performance of the negative electrode material. Embodiment

[0050] The present embodiment 1 provides a preparation method of an antimony-based composite negative electrode material, comprising the following steps:

[0051] S1, preparing an antimony-based intermediate: 4g of micron-sized antimony metal powder and 5.5g of oil-soluble phenolic resin are stirred and mixed, then put into a ball mill pot, the ball-to-material ratio is set to 15, the rotation speed is 500rpm, ball milling for 8h, then filtered, the obtained solid is transferred to a drying oven for drying treatment at 70℃ for 12h to obtain an antimony-based precursor, and then the antimony-based precursor is transferred to a tube furnace filled with argon, heated from room temperature to 1200℃ at a rate of 5℃ / min, and then kept for 3h to obtain the antimony-based intermediate;

[0052] S2, preparation of modified carbon nanotubes: after soaking multi-walled carbon nanotubes in 75% nitric acid for 25h, the filtered product is washed with deionized water for three times, and the washed filtered product is dried in a drying oven at 70℃ for 12h to obtain acidified carbon nanotubes; the acidified carbon nanotubes are added into a siloxane solution (85% of saturated concentration of KH560) at a solid-liquid ratio of 0.06, and dispersed by mechanical stirring at 200rpm for 3h, then filtered and washed, and the washed filtered product is dried in a drying oven at 60℃ for 8h to obtain activated carbon nanotubes; the activated carbon nanotubes are dispersed in an organic sodium modified solution (80% of saturated concentration of ethylenediaminetetraacetic acid disodium salt) at a solid-liquid ratio of 0.06, and dispersed by mechanical stirring at 200rpm for 3h, then filtered and washed, and the washed filtered product is dried in a drying oven at 60℃ for 8h to obtain modified carbon nanotubes;

[0053] S3, preparation of antimony-based composite negative electrode material: 4.0g of antimony-based intermediate and 0.5g of modified carbon nanotubes are added into 78g of deionized water and magnetically stirred to form a suspension, and a spray drying device is used to spray dry the suspension at an inlet temperature of 160℃ to obtain a powder-like antimony-based composite negative electrode material. Example

[0054] This embodiment 2 provides a preparation method of an antimony-based composite negative electrode material, which is different from the embodiment 1 in that 5.5g of pitch is selected as the amorphous carbon precursor in step S1. Example

[0055] This embodiment 3 provides a preparation method of an antimony-based composite negative electrode material, which is different from the embodiment 1 in that 4.0g of antimony-based intermediate, 0.5g of sodium polyacrylate and 0.5g of modified carbon nanotubes are added into 78g of deionized water and magnetically stirred to form a suspension in step S3.

[0056] Comparative Example 1

[0057] This comparative example 1 provides a preparation method of an antimony-based composite negative electrode material, which is different from the embodiment 1 in that: in S3, 4.0g of antimony-based intermediate and 0.5g of modified carbon nanotubes are added into 78g of deionized water and magnetically stirred to form a suspension, and then the suspension is left to settle and precipitate, and the filtered and dried product is obtained as a powder-like antimony-based composite negative electrode material.

[0058] Comparative Example 2

[0059] This comparative example 2 provides a preparation method of an antimony-based composite negative electrode material, which is different from the embodiment 1 in that steps S2 and S3 are not performed, and the obtained antimony-based intermediate after completing step S1 is the antimony-based composite negative electrode material.

[0060] Comparative Example 3

[0061] Comparative Example 3 provides a preparation method of the antimony-based composite negative electrode material, which is different from Example 1 in that step S2 is not performed, and directly using multi-walled carbon nanotubes in step S3.

[0062] Comparative Example 4

[0063] Comparative Example 4 provides a preparation method of the antimony-based composite negative electrode material, which is different from Example 1 in that in step S2, the activated carbon nanotubes are dispersed in a saturated solution of sodium dodecyl sulfate at a solid-liquid ratio of 0.06.

[0064] Comparative Example 5

[0065] Comparative Example 5 provides a preparation method of the antimony-based composite negative electrode material, which is different from Example 1 in that in step S3, after the antimony-based intermediate and the modified carbon nanotubes are sufficiently ground, the antimony-based composite negative electrode material is prepared by calcining at 500°C under an argon atmosphere for 3h.

[0066] Comparative Example 6

[0067] Comparative Example 6 provides a preparation method of the antimony-based composite negative electrode material, which is different from Example 1 in that in step S3, after the powder-like material is prepared using a spray drying device, the antimony-based composite negative electrode material is prepared by calcining at 300°C under an argon atmosphere for 3h.

[0068] Comparative Example 7

[0069] Comparative Example 7 provides a preparation method of the antimony-based composite negative electrode material, which is different from Example 1 in that step S2 is not performed, and directly using 0.5g of multi-walled carbon nanotubes with 4.0g of the antimony-based intermediate and 0.5g of sodium polyacrylate to configure a suspension liquid in step S3.

[0070] The antimony-based composite negative electrode materials prepared in Examples 1 to 3 and Comparative Examples 1 to 7 are assembled into sodium ion button-type half-batteries, and a mixed solution of 1M NaClO4(sodium perchlorate) / EC(ethylene carbonate):DEC(diethyl carbonate) at a volume ratio of 1:1 is used as an electrolyte. The cycle performance test is carried out under the test conditions of 0.01-2.5V and a current density of 100mA / g, and the test results are shown in Table 1. Figure 3

[0071] From Figure 3 ​It can be seen from the above that the first charge specific capacity of the negative electrode material prepared by the method provided by the present application is good, and the capacity retention rate is good during long cycle, so it can be illustrated that the negative electrode material prepared by the method provided by the present application has good cycle stability and capacity retention performance, and it can also be seen that the sodium polyacrylate is added in example 3, the dispersion uniformity of the antimony-based intermediate and the modified carbon nanotube is promoted, so as to improve the cycle stability of the negative electrode material, and the sodium polyacrylate can also be organically combined with the organic sodium on the surface of the modified carbon nanotube, which is beneficial to the formation of SEI film on the surface of the negative electrode material, and the negative electrode material is better protected.

[0072] From Figure 3 It can also be seen from the above that the combination performance between the antimony-based intermediate and the modified carbon nanotube is poor in comparative example 1 due to the fact that the spray drying is not performed, so that the capacity of the negative electrode material is seriously reduced during the cycle, and the antimony-based expansion effect of the antimony-based intermediate is difficult to inhibit in comparative example 2 due to the fact that the antimony-based intermediate is directly used as the negative electrode material, and the cycle stability of the negative electrode material can be improved in comparative example 3 by directly using the multi-arm carbon nanotube, but compared with example 1 and example 2, it can be illustrated that the multi-arm carbon nanotube is modified by the method provided by the present application, and has obvious positive effect.

[0073] And from Figure 3 It can also be seen from the above that the cycle performance and rate performance of the negative electrode material cannot be obviously improved after the sodium dodecyl sulfate is used as the organic sodium and is compounded with the active carbon nanotube in comparative example 4, because the sodium dodecyl sulfate is only used as a dispersant, and the dispersion performance of the antimony-based intermediate and the carbon nanotube is only slightly improved, so that the cycle performance of the battery is slightly improved.

[0074] And in comparative example 5, the antimony-based intermediate and the modified carbon nanotube are ground, which can damage the carbon-coated structure formed on the surface of the antimony-based intermediate, so that the antimony metal powder in the antimony-based intermediate is exposed, and then Figure 3 As shown in the above, the cycle performance of the negative electrode material in comparative example 5 is obviously reduced.

[0075] And the internal organic sodium is carbonized into inorganic carbon network structure after the spray drying and high-temperature calcination of comparative example 6, although the anchoring ability of the antimony metal powder in the antimony-based composite and the compactness of the carbon network structure can be improved, but the SEI film structure formed by the organic sodium is lacking, and the cycle performance is still obviously reduced.

[0076] In comparative example 7, the multi-arm carbon nanotube, the antimony-based intermediate and the sodium polyacrylate are spray dried, and the sodium polyacrylate can only have similar effect as the sodium dodecyl sulfate, and the cycle performance of the negative electrode material is not obviously improved, and the sodium polyacrylate is also difficult to form the SEI film structure when used in the negative electrode material.

[0077] While the embodiments of the application have been illustrated and described in detail, it will be readily apparent to those skilled in the art that various modifications and changes can be made to the embodiments without departing from the scope of the application as described in the claims. It is therefore intended that the application not be limited to the exact embodiments described herein, but that the application can also include all such modifications and changes as fall within the scope of the claimed application. Moreover, the application illustratively described herein suitably can be practiced in the absence of any element or step which is not specifically disclosed herein.

Claims

1. A method for preparing an antimony-based composite negative electrode material, characterized in that, The method comprises the following steps: The antimony metal powder is mixed with the amorphous carbon precursor, ball-milled, dried, and calcined to obtain an antimony-based intermediate; The carbon nanotubes are subjected to surface acidification treatment to obtain acidified carbon nanotubes, the acidified carbon nanotubes are dispersed in an organic sodium modified solution, stirred, filtered, and dried to obtain modified carbon nanotubes; the solute of the organic sodium modified solution is disodium ethylenediaminetetraacetate; The antimony-based intermediate, sodium polyacrylate, and the modified carbon nanotubes are mixed and dispersed to obtain a suspension, which is spray-dried to obtain an antimony-based composite negative electrode material; in the antimony-based composite negative electrode material, the antimony metal powder is adsorbed on the surface defect position of the amorphous carbon, and after being combined with the modified carbon nanotubes, a three-dimensional conductive network formed by the modified carbon nanotubes is wrapped on the outermost layer of the antimony metal powder and the amorphous carbon.

2. The production method according to claim 1, characterized by, In the process of mixing the antimony metal powder with the amorphous carbon precursor, ball-milling, drying, and calcining to obtain the antimony-based intermediate, the antimony metal powder is mixed with the amorphous carbon precursor at a mass ratio of 0.5-1, ball-milled, and then subjected to suction filtration and drying to obtain an antimony-based precursor; the antimony-based precursor is calcined at 1000-1300°C in an inert atmosphere for 2-4h to obtain the antimony-based intermediate.

3. The production method according to claim 2, characterized by, In the process of mixing the antimony metal powder with the amorphous carbon precursor, ball-milling, and then suction filtration and drying to obtain the antimony-based precursor, the antimony metal powder is mixed with the amorphous carbon precursor at a mass ratio of 0.5-1, ball-milled, and then subjected to suction filtration; the suction filtration product is subjected to drying treatment at 50-80°C for 10-14h to obtain the antimony-based precursor.

4. The method of claim 1, wherein, In the process of subjecting the carbon nanotubes to surface acidification treatment to obtain acidified carbon nanotubes, the carbon nanotubes are immersed in nitric acid, subjected to suction filtration and drying to obtain the acidified carbon nanotubes.

5. The preparation method according to claim 4, characterized in that, In the process of subjecting the carbon nanotubes to surface acidification treatment to obtain acidified carbon nanotubes, the carbon nanotubes are immersed in nitric acid for 20-30h, subjected to suction filtration, washed with deionized water, and then subjected to drying at 50-80°C for 10-14h to obtain the acidified carbon nanotubes.

6. The method of claim 1, wherein, In the process of dispersing the acidified carbon nanotubes in an organic sodium modified solution, stirring, filtering, and drying, the process comprises: The acidified carbon nanotubes are stirred in a siloxane solution, filtered, and dried to obtain activated carbon nanotubes; The activated carbon nanotubes are dispersed in an organic sodium modified solution, stirred at 50-60°C for 5-6h, and then subjected to suction filtration and drying.

7. The production method according to claim 6, characterized by, When the acidified carbon nanotubes are stirred in a siloxane solution and filtered, the solute of the siloxane solution comprises at least one of γ-aminopropyltrimethoxysilane and γ-glycidyl ether oxypropyltrimethoxysilane.

8. An antimony-based composite negative electrode material prepared by the preparation method in any one of claims 1 to 7.

9. Use of an antimony-based composite negative electrode material prepared by the preparation method in any one of claims 1 to 7 in a sodium ion battery.

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