CN108963237A - A kind of preparation method of anode material of lithium-ion battery - Google Patents

Abstract

The invention relates to a preparation method of a negative electrode material of a sodium ion battery. The method uses antimony trichloride, selenium powder, and triethylene glycol as raw materials to prepare rod-shaped antimony selenide through a polyol method, and then uses antimony selenide and carbon nanotubes as main materials, through water vapor etching and spray drying, Microspheres with evenly distributed antimony selenide nanorods and carbon nanotubes are obtained. The spherical structure of the material can effectively solve the problem of large volume changes when antimony selenide is used as the positive electrode material in sodium-ion batteries, and more defects are formed on the surface of antimony selenide/carbon nanotube composite materials by water etching to improve the electronic efficiency. And the transport speed of ions, so as to improve the electrochemical performance and cycle stability of lithium-sulfur batteries as a whole.

Description

A kind of preparation method of sodium ion battery negative electrode material

technical field

The invention relates to the technical field of negative electrode materials for sodium ion batteries, in particular to a method for preparing an antimony selenide/carbon nanotube composite material used for the negative electrode of sodium ion batteries.

Background technique

Energy is one of the important elements driving the progress of human civilization. With the development of modern industrialization and emerging technologies, traditional energy sources such as fossils, coal, oil and natural gas are being consumed at an accelerated rate. The ensuing global energy crisis has not only seriously affected people's basic life. In addition, the environmental problems caused by the excessive use of traditional energy cannot be ignored. In order to deal with the above problems, clean energy sources such as wind energy, solar energy, tidal energy, biomass energy and geothermal energy are being gradually developed and used. The total amount of these renewable clean energy is large but the energy density is small, and the energy supply also has randomness and discontinuity in time and space. Therefore, in order to meet the convenience of people's use of these clean energy in daily life, various energy storage devices that can meet the actual needs have been widely developed and used.

At present, lithium-ion batteries are widely used in portable electronic devices. With the large-scale development and application of power vehicles and electronic portable devices, the limited lithium resources on the earth may lead to an increase in the cost of lithium-ion batteries, which will eventually be consumed quickly Exhausted. Therefore, sodium-ion secondary batteries, whose electrochemical performance is similar to that of lithium-ion batteries, have become the most suitable substitutes. Although sodium ions are heavier than lithium ions, except for power vehicles that need to consider battery energy and volume density, other small energy storage devices (such as mobile phone batteries, notebook batteries, etc.) Great possibility. There are many similarities in the properties of sodium and lithium, which are both the main group I of the periodic table, so the constructed sodium-ion battery is similar to the lithium-ion battery in many respects. Its basic working principle is the same as that of the "rocking chair battery" of lithium-ion batteries, using simple substances or compounds that can reversibly intercalate and deintercalate sodium ions as the positive and negative electrodes of the battery system. Sodium is rich in resources and easy to obtain, and sodium has a higher half-cell potential than lithium, so an electrolyte with a low decomposition voltage can be used, so the safety performance is expected to be better than that of lithium-ion batteries. Therefore, in order to realize the sustainable development of the battery industry, it is the general trend to develop new energy storage batteries that are pollution-free to the environment, and sodium-ion batteries are just one of these new high-energy green batteries.

Although sodium-ion batteries have the above advantages, due to the large radius of sodium ions, when the interlayer distance of the negative electrode is smaller than the diameter of sodium ions, it will be difficult for sodium ions to intercalate into the negative electrode and the intercalation amount of sodium ions is very small, resulting in the ratio of sodium-ion batteries Very low capacity. Moreover, when sodium can be embedded in the negative electrode material, it will recombine to form a compound, but the volume expansion of the material is very serious when the compound is formed, and even causes the electrode to break and pulverize, resulting in a rapid decline in electrochemical performance. Therefore, cycle stability is difficult to solve. In general, sodium-ion batteries that can replace lithium-ion batteries have attracted the attention of scientists around the world, but there are still many problems in sodium-ion batteries that need further research to solve.

Antimony-based materials have become promising anode materials for Na-ion batteries due to their high Na-ion intercalation capacity. Among them, antimony selenide, as a typical V-VI compound, is a direct bandgap P-type semiconductor with a layered structure, and is widely used in the fields of hydrogen storage, photocatalysis, and electrochemical energy storage. Moreover, 1mol of antimony selenide can intercalate 12mol of sodium ions, and the reaction is reversible, and finally a theoretical specific capacity of up to 678mAh g ^-1 can be obtained. However, when antimony selenide is used as the anode material of sodium-ion batteries, it will produce large volume expansion and contraction during the reversible reaction process, which may lead to cracking and crushing of the electrode as the number of cycles increases, thus leading to its cycle stability. Poor performance, this shortcoming greatly limits its wide application. Therefore, it is necessary to improve the reactivity of the battery by controlling the morphology of the product, and reduce the volume change during charge and discharge by reducing the size of the material or compounding with other materials, thereby improving its cycle performance. CN 107140609A discloses a method for hydrothermally preparing bundled antimony selenide electrode materials for sodium-ion battery negative electrodes by microwave oven. The antimony selenide nanobeams prepared by this material are large in size, with a length of up to 6-7 μm, and the top of the nanobeams is formed by agglomeration of antimony selenide nanowires. Volume expansion and contraction are extremely unfavorable, and easily cause cracking and crushing of electrodes, which is not conducive to the cycle stability of lithium-sulfur batteries. Therefore, the development of new antimony selenide sodium ion battery anode materials has become the focus of attention.

Contents of the invention

The technical problem to be solved in this patent is to provide a preparation method for the negative electrode material of a sodium ion battery in view of the shortcomings existing in the current technical center. The method uses antimony trichloride, selenium powder, and triethylene glycol as raw materials to prepare rod-shaped antimony selenide through a polyol method, and then uses antimony selenide and carbon nanotubes as main materials, through water vapor etching and spray drying, Microspheres with evenly distributed antimony selenide nanorods and carbon nanotubes are obtained. The spherical structure of the material can effectively solve the problem of large volume changes when antimony selenide is used as the positive electrode material in sodium-ion batteries, and more defects are formed on the surface of antimony selenide/carbon nanotube composite materials by water etching to improve the electronic efficiency. And the transport speed of ions, so as to improve the electrochemical performance and cycle stability of lithium-sulfur batteries as a whole.

Technical scheme of the present invention is as follows:

A preparation method of a negative electrode material for a sodium ion battery, comprising the steps of:

Step 1: Prepare antimony trichloride solution; wherein, the solvent is triethylene glycol, and 0.5-2 g of antimony trichloride is added to every 20-50 mL of triethylene glycol;

Step 2: prepare a selenium solution with a concentration of 0.2-2 mmol/mL; wherein, the solvents are ethanolamine and hydrazine hydrate, and the volume ratio of ethanolamine and hydrazine hydrate is 1-5:1;

Step 3: Prepare antimony selenide dispersion liquid:

Add the selenium solution, polyvinylpyrrolidone and triethylene glycol prepared in step 2 into the airtight container, vacuumize and pass in argon gas, then raise the temperature to 200-250°C, and then inject into step 1 through the syringe to obtain Stir and react at 200-250°C for 20-50 minutes; after cooling to room temperature, centrifuge to obtain antimony selenide, add it to deionized water and ultrasonically disperse to obtain an aqueous phase suspension of antimony selenide liquid;

Among them, every 7-20mL of selenium solution prepared in step 2 is added with 0.2-2g of polyvinylpyrrolidone, 10-50mL of triethylene glycol and 20-200mL of antimony trichloride solution; every 1g of antimony selenide is added with 10-20mL Deionized water;

Step 4: Prepare powder by spraying: dilute the antimony selenide aqueous phase suspension to 10 to 100 times the original volume, sonicate for 0.5 to 1.5 hours; then add carbon nanotube powder, continue to sonicate for 0.5 to 1.5 hours; then spray to obtain selenium Antimony/carbon nanotube powder;

Among them, the mass ratio of antimony selenide to carbon nanotubes is 1:0.2-1.5, and the parameters of the spray drying instrument are: air intake volume 100%, feed rate 3-10mLmin ^-1 , air intake temperature 150-200°C;

Step 5: Water vapor etching:

Place the antimony selenide/carbon nanotube powder in a tube furnace, and seal the tube furnace under an argon atmosphere; then heat the tube furnace to 200-400°C; then pass in the mixed gas for 3-10 minutes, turn off the tube Type furnace, after cooling to room temperature, obtain antimony selenide/carbon nanotube composite material, namely the preparation method of sodium ion battery anode material; Wherein, the composition of mixed gas is water vapor and argon, and the volume of water vapor is mixed gas 10-30% of the volume.

The heating rate in the fifth step is 5-10°C min ^-1 .

In the preparation method of the antimony selenide/carbon nanotube composite material used for the negative electrode of the sodium ion battery, the raw materials involved are all commercially available, and the equipment and processes used are well known to those skilled in the art.

Compared with the prior art, the outstanding substantive features of the inventive method are as follows:

1. The layer spacing of antimony selenide is relatively large, 1 mole of antimony selenide can intercalate 12 moles of sodium ions, and the reaction is reversible, so that a higher specific capacity can be obtained.

2. The preparation process of the antimony selenide/carbon nanotube composite material is simple, the process is intuitive, and the cost is low.

3. The antimony selenide/carbon nanotube composite material is prepared by spray drying method. The carbon nanotubes form a three-dimensional network structure, and the rod-shaped antimony selenide is uniformly interspersed in it. This structure greatly shortens the reaction process. The transmission path of electrons, and because of the strong flexibility of carbon nanotubes, can effectively alleviate the volume change of the electrode during charging and discharging, thereby improving the electrochemical performance of lithium-sulfur batteries.

4. Through water vapor etching, more atomic defects are produced on the surface of the antimony selenide/carbon nanotube composite material, which is conducive to the transmission of electrons and ions during the reaction process, and the holes etched on the surface are conducive to alleviating the filling The volume change of the electrode during the discharge process maintains the integrity of the electrode and improves its cycle performance.

Compared with prior art, the remarkable progress that the inventive method has is as follows:

1. Compared with the prior art CN 107256967 A, the present invention combines antimony selenide rods with nanostructure and uniform distribution with carbon nanotubes with excellent electrical conductivity and flexibility through spray drying, which can effectively buffer its The volume change when used as the negative electrode material of sodium ion battery, and the rod-shaped antimony selenide inside the spherical antimony selenide/carbon nanotube composite material crosses each other to produce a large number of pores can also buffer the volume change generated during the charge and discharge process, thus improving the performance of the battery . However, the spherical antimony selenide prepared in the prior art CN 107256967 A is very easy to agglomerate, so when it is used as the negative electrode material of a sodium ion battery, it is easy to produce a large volume change, resulting in cracking of the pole piece and shedding of the active material, resulting in poor cycle performance. And the surface of the antimony selenide ball prepared in the prior art CN 107256967 A is smooth, and the present invention has a large number of defects due to water vapor etching on the surface, therefore, the prior art CN 107256967 A has fewer defects than the present invention, which is unfavorable for the reaction The transmission of electrons and ions in the process leads to low utilization of active materials, which can be expressed by the electrochemical charge-discharge specific capacity. The second discharge specific capacity of the antimony selenide/carbon nanotube composite material prepared in the present invention as the negative electrode of the sodium ion battery is 657mAh g ^-1 , far higher than the 495mAh second discharge capacity of the prior art CN 107256967 A g ^-1 .

2. Compared with the prior art CN 107140608 A, the present invention has short reaction time, short experiment period, no need for freeze-drying, one-step drying and one-step uniform compounding with carbon nanotubes through spray drying, and hydrazine hydrate participates in the reaction in a closed reaction apparatus , less air pollution. However, in the prior art CN 107140608 A, the experimental reaction cycle is long, and hydrazine hydrate needs to be configured with selenium powder to form a solution and then ultrasonicated in the air, which causes great pollution to the environment. The balls formed by the antimony selenide/carbon nanotube composite material obtained by spray drying in the present invention are smaller in size and uniformly distributed between 3-3.5 μm, while the antimony selenide negative electrode prepared in the prior art CN 107140608A The material agglomerates seriously, and the diameter distribution is 20-30 μm. Therefore, when the material obtained in the present invention is used as the negative electrode of a sodium ion battery, the contact area with the electrolyte is larger, which is beneficial to improving the utilization rate of the active material. And in the present invention, the three-dimensional network carbon nanotubes obtained by spray drying and the defects produced by water vapor etching further provide ion transport channels, and the flexibility of carbon nanotubes and the more holes etched by water vapor further alleviate the selenium The problem of volume expansion caused by antimony as the negative electrode of the battery, while in the prior art CN 107140608 A, the single-phase antimony selenide nanorods are aggregated to form an irregular spherical structure with a diameter of 20-30 μm, which is used as the negative electrode material of the sodium ion battery in the charging process. During the discharge process, a large volume change will occur, and its buffer space is extremely small, which may easily cause the pole piece to crack, resulting in poor cycle performance. And the addition of carbon nanotubes in the present invention can further shorten the transmission path of electrons and ions, and improve the utilization rate of active materials, but there is no such thing in the prior art CN 107140608 A, thus resulting in poor electrochemical results. In the present invention, the second The first charge and discharge curve shows that the second discharge capacity reaches 657mAh g ^-1 , and the coulombic efficiency is as high as 99.7%, while the electrochemical results of the state-of-the-art CN 107140608 A obtain a capacity of about 608mAh g ^-1 during the second discharge, which is far Lower than the discharge specific capacity in the present invention.

In a word, the antimony selenide/carbon nanotube composite material prepared by the present invention solves the problems of low capacity and poor circulation of the existing antimony selenide material as a sodium ion battery. The nanotubes form a three-dimensional network structure, and the rod-shaped antimony selenide is uniformly interspersed in it, and the rod-shaped antimony selenide is interlaced with each other, and a large number of pores are generated inside the spherical structure, thereby overcoming the volume expansion and circulation of antimony selenide as a battery negative electrode material. The disadvantage of poor performance. And through water vapor etching, more surface defects are produced on the surface of the spherical antimony selenide/carbon nanotube composite material, which is conducive to the transmission of ions and electrons during the reaction process, thereby improving the utilization of active materials, so antimony selenide/carbon nanotube composites The carbon nanotube composite material as the negative electrode has excellent rate performance and cycle performance of sodium ion batteries, and is a battery with great market prospects.

Description of drawings

FIG. 1 is an X-ray diffraction pattern of the antimony selenide/carbon nanotube composite material prepared in Example 2.

2 is a scanning electron microscope image of the antimony selenide/carbon nanotube composite material prepared in Example 2.

Fig. 3 is the second charge and discharge curve at a current density of 0.1C when the antimony selenide/carbon nanotube composite material prepared in Example 2 is used as the negative electrode of a sodium ion battery.

Detailed ways

Example 1

The first step, prepare the solution:

Weigh 1 g of antimony trichloride and add it to 20 mL of triethylene glycol, and stir it on a magnetic stirrer to completely dissolve the antimony trichloride and put it aside for later use.

The second step is to prepare selenium solution:

Mix ethanolamine and hydrazine hydrate at a ratio of 4:1, and add selenium powder to it to prepare a selenium solution with a concentration of 1 mmol/mL, and set it aside for later use.

The third step is to prepare antimony selenide dispersion:

Take a three-necked flask, add 7mL of selenium solution prepared in step 2, 1g of polyvinylpyrrolidone and 20mL of triethylene glycol to it, block the left bottle mouth with a bottle stopper with a needle, and block the middle bottle mouth Connect to the condenser tube, insert a thermometer into the mouth of the right bottle, confirm that the instrument is airtight, and start vacuuming. When the inside of the experimental instrument is vacuumed, argon gas is introduced, and repeated 3 times. Insert the syringe containing 20mL of the mixed solution prepared in step 1 into the three-necked bottle, turn on the stirring heater to start stirring and heating, raise the temperature to 210°C, inject all the liquid in the syringe, control the temperature at 210°C, and react for 20 minutes. After the three-neck flask was cooled to room temperature, centrifuge to obtain 1.05 g of Sb ₂ Se ₃ , add 15 mL of deionized water and sonicate to obtain a Sb ₂ Se ₃ aqueous phase suspension.

The fourth step, spray preparation powder:

Dilute the antimony selenide aqueous phase suspension to 350mL and put it into an ultrasonic machine for 0.5h. Take 0.5 g of carbon nanotube powder and add it to the antimony selenide dispersion liquid and continue to put it into an ultrasonic machine for ultrasonication for 0.5 h. Then spray to obtain antimony selenide/carbon nanotube powder. The parameters of the spray drying instrument are: air intake volume 100%, feed rate 5mL/min, and air intake temperature 180°C.

The fifth step, water vapor etching:

The antimony selenide/carbon nanotube powder is placed in a tube furnace, and both ends of the tube furnace are sealed. Prepare an Erlenmeyer flask and seal it with a rubber stopper with three vent tubes, which are respectively connected to the water bottle, argon gas bottle and tube furnace through rubber tubes. First, close the rubber tube connected to the water bottle tightly, and pass argon gas into the conical flask, so that the argon gas enters the tube furnace through the conical bottle, and after 1 hour, the air is driven out, and the heating switch of the tube furnace is turned on. The heating rate of min ^-1 was increased to 200 °C. At the same time, 20 mL of deionized water was passed into the Erlenmeyer flask, and the water bath was turned on to heat the water in the Erlenmeyer flask to 85°C. Then pass the argon gas into the deionized water with a temperature of 85°C and then pass it into the tube furnace, so that the argon gas passing into the tube furnace contains water vapor, and the content of water vapor is controlled by the flow rate of the argon gas. The flow rate of the argon gas was controlled at 2L/min. At this time, the water vapor content in the argon gas was 25%. Antimony selenide/carbon nanotube composites after etching.

The sixth step, the preparation of the negative electrode sheet of the battery and the assembly of the battery:

The prepared antimony selenide/carbon nanotube composite material, conductive agent and binder were placed in a mortar according to the mass ratio of 8:1:1, ground and mixed to form a slurry, and the slurry was evenly scraped on the On the copper foil, dry at 55° C. for 24 hours, and press into a thin sheet using a tablet press under a pressure of 5 MPa to obtain a negative electrode sheet. The obtained antimony selenide/carbon nanotubes were used as the negative electrode and the metal Li sheet was used as the positive electrode, and the electrolyte was added, and the battery was assembled in a glove box to obtain a button-type CR2025 half-cell.

Electrochemical performance analysis (BTS-5V5mA, Xinwei) was performed on the prepared samples.

The rod-shaped antimony selenide prepared in Example 1 has a length distribution of 1-1.5 μm and a width of 50-100 nm, and the average diameter of the antimony selenide/carbon nanotube composite nanospheres prepared by spraying is distributed between 3.5-4.1 μm . And due to water vapor etching, more porous structures are produced on the surface. Electrochemical results show that its second discharge capacity is 628mAh g ^-1 .

Example 2

Others are the same as in Example 1, except that the fourth step is to dilute the antimony selenide aqueous phase suspension to 500 mL, and the fifth step is to raise the temperature of the tube furnace to 300°C.

FIG. 1 is an X-ray diffraction pattern of the antimony selenide/carbon nanotube composite material prepared in Example 2. It can be seen from the figure that there is a relatively broad peak at 26°, which is the carbon peak of carbon nanotubes. The rest of the peaks correspond to the peaks of antimony selenide, thus proving the successful synthesis of the composite material of antimony selenide/carbon nanotubes.

2 is a scanning electron microscope image of the antimony selenide/carbon nanotube composite material prepared in Example 2. It can be seen that the rod-shaped antimony selenide has a length distribution of 1-1.5 μm and a width of 50-100 nm. The antimony selenide/carbon nanotubes obtained by spraying are uniformly distributed in a spherical structure with a diameter of 3-3.5 μm. The rod-shaped selenium Antimony is uniformly entangled by carbon nanotubes. And there are a large number of hole structures on the surface of the spherical structure.

Fig. 3 is the second charge and discharge curve at a current density of 0.1C when the antimony selenide/carbon nanotube composite material prepared in Example 2 is used as the negative electrode of a sodium ion battery. The second discharge capacity of the sodium ion battery with the antimony selenide/carbon nanotube as the negative electrode is 657mAh g ^-1 , and the coulombic efficiency is as high as 99.7%.

Example 3

Others are the same as in Example 1, except that the fourth step is to dilute the antimony selenide aqueous phase suspension to 650 mL, and the fifth step is to raise the temperature of the tube furnace to 400°C.

The rod-shaped antimony selenide prepared in Example 3 has a length distribution of 1 to 1.5 μm and a width of 50 to 100 nm. The antimony selenide/carbon nanotube composite material prepared by spraying, due to the low concentration of the precursor solution prepared before spray drying, The nanostructure size of the antimony selenide/carbon nanotube composite material prepared by spraying is small, and the diameter is averagely distributed between 2 and 2.8 μm, and the surface pores are obviously enlarged due to the high water vapor etching temperature. Electrochemical results show that its second discharge capacity is 649mAh g ^-1 .

Example 4

Others are the same as in Example 1, except that 1.5 g of antimony selenide is added to 20 mL of triethylene glycol in the first step, and the concentration of the selenium solution configured in the second step is 1.5 mmol/mL.

The rod-shaped antimony selenide prepared in Example 4 has a length distribution of 1.2-1.6 μm and a width distribution of 80-120 nm, and the diameter distribution of the antimony selenide/carbon nanotube composite material obtained by spraying is 3.1-3.5 μm, and there is more water vapor on the surface Holes created by etching. Electrochemical results show that its second discharge capacity is 622mAh g ^-1 .

Example 5

Others are the same as in Example 1, except that 2 g of antimony selenide is added to 20 mL of triethylene glycol in the first step, and the concentration of the selenium solution configured in the second step is 2 mmol/mL.

The rod-shaped antimony selenide prepared in Example 5 has a length distribution of 1.5-1.9 μm and a width distribution of 90-135 nm, and the diameter distribution of the antimony selenide/carbon nanotube composite material obtained by spraying is 3.2-3.6 μm, and there is more water vapor on the surface Holes created by etching. Electrochemical results show that its second discharge capacity is 628mAh g ^-1 .

Example 6

Others are the same as in Example 1, except that in the third step, the reaction temperature is raised to 230° C., and the reaction time is extended to 35 minutes.

The rod-shaped antimony selenide prepared in Example 6 has a length distribution of 1.8-1.9 μm and a width distribution of 70-105 nm, and the diameter distribution of the antimony selenide/carbon nanotube composite material obtained by spraying is 3.1-3.3 μm, and there is more water vapor on the surface Holes created by etching. Electrochemical results show that its second discharge capacity is 638mAh g ^-1 .

Example 7

Others are the same as in Example 1, except that in the third step, the reaction temperature is raised to 250° C., and the reaction time is extended to 50 minutes.

The rod-shaped antimony selenide prepared in Example 7 has a length distribution of 1.85-2 μm and a width distribution of 90-110 nm. The diameter distribution of the antimony selenide/carbon nanotube composite material obtained by spraying is 3.2-3.5 μm, and there are many water vapor scratches on the surface. Holes created by corrosion. Electrochemical results show that its second discharge capacity is 630mAh g ^-1 .

In order to solve the problem that antimony selenide is applied to the negative electrode of sodium ion battery, the antimony selenide/carbon nanotube composite material is processed by water vapor etching technology in the present invention, so that a large amount of antimony selenide/carbon nanotube composite material is produced on the surface of the antimony selenide/carbon nanotube composite material. Atomic defects, which are beneficial to the transport of ions and electrons during charge and discharge, thus improving the charge and discharge efficiency. Moreover, holes are formed on the surface, which is beneficial to alleviate the volume effect during the charging and discharging process and maintain the integrity of the structure. In addition, in the present invention, the antimony selenide/carbon nanotube composite material is prepared by a spray drying method as the negative electrode material of the sodium ion battery. Since carbon nanotube materials have some excellent characteristics, their combination with antimony selenide can improve many problems of antimony selenide, such as further improving its electrical conductivity, shortening the transmission path of electrons and ions, thereby improving its electrochemical performance. Moreover, carbon nanotubes have high flexibility, which can effectively buffer the volume change of antimony selenide during charging and discharging by interlacing each other to form a three-dimensional network structure, thereby improving the cycle performance of the battery.

Matters not covered in the present invention are known technologies.

Claims (2)

1. a preparation method of sodium ion battery negative electrode material, is characterized in that comprising the steps: Step 1: Prepare antimony trichloride solution; wherein, the solvent is triethylene glycol, and 0.5-2 g of antimony trichloride is added to every 20-50 mL of triethylene glycol; Step 2: prepare a selenium solution with a concentration of 0.2-2 mmol/mL; wherein, the solvents are ethanolamine and hydrazine hydrate, and the volume ratio of ethanolamine and hydrazine hydrate is 1-5:1; Step 3: Prepare antimony selenide dispersion liquid: Add the selenium solution, polyvinylpyrrolidone and triethylene glycol prepared in step 2 into the airtight container, vacuumize and pass in argon gas, then raise the temperature to 200-250°C, and then inject into step 1 through the syringe to obtain Stir and react at 200-250°C for 20-50 minutes; after cooling to room temperature, centrifuge to obtain antimony selenide, add it to deionized water and ultrasonically disperse to obtain an aqueous phase suspension of antimony selenide liquid; Among them, every 7-20mL of selenium solution prepared in step 2 is added with 0.2-2g of polyvinylpyrrolidone, 10-50mL of triethylene glycol and 20-200mL of antimony trichloride solution; every 1g of antimony selenide is added with 10-20mL Deionized water; Step 4: Prepare powder by spraying: dilute the antimony selenide aqueous phase suspension to 10 to 100 times the original volume, sonicate for 0.5 to 1.5 hours; then add carbon nanotube powder, continue to sonicate for 0.5 to 1.5 hours; then spray to obtain selenium Antimony/carbon nanotube powder; Among them, the mass ratio of antimony selenide to carbon nanotubes is 1:0.2-1.5, and the parameters of the spray drying instrument are: air intake volume 100%, feed rate 3-10mLmin ^-1 , air intake temperature 150-200°C; Step 5: Water vapor etching: Place the antimony selenide/carbon nanotube powder in a tube furnace, and seal the tube furnace under an argon atmosphere; then heat the tube furnace to 200-400°C; then pass in the mixed gas for 3-10 minutes, turn off the tube Type furnace, after cooling to room temperature, obtain antimony selenide/carbon nanotube composite material, namely the preparation method of sodium ion battery anode material; Wherein, the composition of mixed gas is water vapor and argon, and the volume of water vapor is mixed gas 10-30% of the volume. 2. The method for preparing the negative electrode material of the sodium ion battery according to claim 1, characterized in that the heating rate in the fifth step is 5-10°C min ^-1 .