Three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material and preparation method thereof

Abstract

The present invention relates to a preparation method for a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube, wherein cotton is put into a titanium chloride aqueous solution and fully soaked, the cotton is taken out and drained, and then the cotton is put into a CVD tubular furnace, and is heated to a given temperature under an ammonia atmosphere, wherein the titanium chloride aqueous solution is 15-20wt%, and is heated to 500 DEG C; the weight volume ratio (w / v, g / ml) of cotton to the titanium chloride aqueous solution is 1: 25-75; then the atmosphere in the CVD tubular furnace is heated and kept warm under a hydrogen reducing atmosphere. The beneficial effects of the present invention are that the preparation process is simple, and it is convenient to quickly and massively produce three-dimensional reduced conductive titanium dioxide tubes; the three-dimensional titanium dioxide prepared is reduced, and its composition is actually TiO2-X, and the performance of the negative electrode material for the battery is better than that of non-reduced titanium dioxide, and the electron transfer rate is higher; the cost of raw materials is low, and the price of titanium chloride and water is cheaper than that of the titanium source tetrabutyl titanate and solvent alcohol of other solutions for preparing titanium dioxide.

Description

Technical Field

[0001] The invention belongs to the technical field of electrodes composed of nano-composite materials, and particularly relates to a three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material and a preparation method thereof. Background Art

[0002] Lithium battery anode materials include carbon and non-carbon materials. Because they provide more lithium ion transfer channels, the three-dimensional porous structure of titanium dioxide composited with carbonized melamine foam has been reported as a lithium battery anode material. For example, Chinese patent application CN111517821A discloses a three-dimensional porous titanium dioxide-loaded lithium battery anode material. The preparation method is to fully absorb tetrabutyl titanate dispersed in ethanol into melamine foam and then calcine it. This three-dimensional porous titanium dioxide-loaded lithium battery anode material has excellent mechanical and lithium battery energy storage properties. However, the material preparation process consumes more energy than the current solution, resulting in high costs and unsuitable for large-scale production by enterprises. Moreover, without hydrogen reduction, the resulting product is ordinary three-dimensional titanium dioxide particles rather than conductive reduced titanium dioxide tubes, which results in slower electron transfer rates when used as a lithium-ion battery anode material. Testing has shown that this method is not suitable for preparing three-dimensional reduced conductive titanium dioxide tubes.

[0003] Titanium dioxide nanotubes have a high specific surface area, high chemical stability, and excellent photoelectric properties. Technologies related to loaded titanium dioxide tubes have been widely reported. For example, Chinese patent application CN108325519A discloses a method for preparing wrinkled TiO2 microtubes. The preparation process involves treating absorbent cotton with anhydrous ethanol, NH3·H2O, and tetrabutyl titanate to obtain dry cotton, which is then calcined in a muffle furnace to produce wrinkled TiO2 microtubes. However, this material cannot be reduced to three-dimensional conductive titanium dioxide tubes without hydrogen reduction. Summary of the Invention

[0004] In response to the above technical problems, the first aspect of the present invention relates to a method for preparing a three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material, comprising the following steps:

[0005] The cotton and titanium trichloride aqueous solution are thoroughly mixed, and then the cotton is taken out and drained, wherein the mass volume ratio of the titanium trichloride aqueous solution is 15-20 wt%; the weight volume ratio of the cotton to the titanium trichloride aqueous solution (w / v, g / ml) is 1:25-75;

[0006] The dried cotton was placed in a CVD tube furnace and heated under an ammonia atmosphere to obtain powder;

[0007] The atmosphere of the CVD tube furnace is changed to a reducing atmosphere of hydrogen, and the temperature is increased and kept warm to obtain a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube.

[0008] A further method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube is provided, wherein:

[0009] The mass volume ratio of the titanium trichloride aqueous solution is 17.5%.

[0010] A further method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube is provided, wherein:

[0011] The weight-to-volume ratio of cotton to titanium trichloride aqueous solution (w / v, g / ml) is 1:50.

[0012] A further method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube is provided, wherein:

[0013] The baking temperature of the CVD tube furnace under the ammonia atmosphere is 200-280 degrees Celsius, and the heating time is 0.8-1.5 hours; preferably, the baking temperature is 240 degrees Celsius, and the heating time is 1 hour.

[0014] A further method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube is provided, wherein:

[0015] The ammonia ventilation rate is 200-240 sccm; preferably, the ammonia ventilation rate is 220 sccm

[0016] A further method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube is provided, wherein:

[0017] The baking temperature of the CVD tube furnace is 550-650 degrees Celsius, the heating time is 0.8 to 1.5 hours, the insulation temperature is 550 to 650 degrees Celsius, and the insulation time is 100 to 140 minutes; preferably, the baking temperature of the high-temperature resistance furnace is 600 degrees Celsius, the heating time is 1.2 hours, the insulation temperature is 600 degrees Celsius, and the insulation time is 120 minutes.

[0018] A further method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube is provided, wherein:

[0019] The hydrogen gas flow rate is 80 to 150 sccm; preferably, the hydrogen gas flow rate is 110 sccm.

[0020] A further method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube, wherein the cotton is fully mixed with the titanium trichloride aqueous solution and then the cotton is taken out and dried, comprises:

[0021] The cotton and the titanium trichloride aqueous solution are fully stirred for 5 to 10 minutes, the cotton is taken out from the solution, and filtered with a suction filtration bottle to obtain filtered cotton; preferably, the stirring is performed for 8 minutes.

[0022] The second aspect of the present invention relates to a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube prepared by the aforementioned method.

[0023] The third aspect of the present invention relates to a lithium-ion battery negative electrode prepared from the lithium-ion battery negative electrode material of the aforementioned three-dimensional reduced conductive titanium dioxide tube.

[0024] The beneficial effects of the present invention are that the three-dimensional reduced conductive titanium dioxide tubes can effectively promote charge transfer efficiency and uniform charge distribution during electrochemical reactions. They can also effectively prevent lithium dendrite deposition and reduce problems caused by volume increase. The three-dimensional titanium dioxide tubes have excellent mechanical properties and, in a reducing atmosphere, can reduce trace amounts of titanium oxides such as titanium trioxide, which can better modify lithium metal. They also offer excellent conductivity and a higher charge transfer rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Total time-voltage graph;

[0026] Figure 2 、 3 SEM images at different magnifications;

[0027] Figure 4 Actual picture of lithium-ion battery negative electrode material of three-dimensional reduced conductive titanium dioxide tube. DETAILED DESCRIPTION

[0028] The following examples further illustrate the present invention, but should not be construed as limiting the present invention. Without departing from the spirit and substance of the present invention, modifications or substitutions made to the methods, steps or conditions of the present invention are within the scope of the present invention.

[0029] The reagents, materials and equipment used in the present invention are all commercially available.

[0030] CVD tubular furnace (Chemical Vapor Deposition Tubular Furnace) is a device that deposits chemical substances produced by gas phase reactions onto a heated substrate to form a thin film.

[0031] Example 1 Lithium-ion battery negative electrode material of three-dimensional reduced conductive titanium dioxide tube

[0032] Weigh 6 g of cotton and mix with 300 ml of 17.5% titanium trichloride aqueous solution by mass volume ratio and stir thoroughly for 8 minutes;

[0033] The cotton was taken out from the solution and filtered with a suction flask. The filtered cotton was placed in a CVD tube furnace and baked at 240 degrees Celsius under an ammonia atmosphere (ammonia ventilation rate of 200 sccm) for 1 hour to obtain a white solid with a powdery texture.

[0034] The ammonia atmosphere of the CVD tube furnace was replaced with hydrogen, and the temperature was raised to 600 degrees Celsius in the reducing atmosphere of hydrogen (hydrogen ventilation flow rate was 110 sccm), the heating time was 1 hour, the holding temperature was 600 degrees Celsius, and the holding time was 120 minutes to obtain a blue-gray three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material.

[0035] Example 2: Lithium-ion battery negative electrode material of three-dimensional reduced conductive titanium dioxide tube

[0036] Weigh 5g of cotton and mix it with 300ml of 15% titanium trichloride aqueous solution by mass volume ratio and stir thoroughly for 10min;

[0037] The cotton was taken out from the reaction solution in the reaction vessel and filtered with a suction flask. The filtered cotton was placed in a CVD tube furnace and heated under an ammonia atmosphere (ammonia ventilation rate of 220 sccm) at a baking temperature of 220 degrees Celsius for a heating time of 0.8 h to obtain a white solid with a powdery texture;

[0038] The ammonia atmosphere of the CVD tube furnace was replaced with hydrogen, and the temperature was raised to 650 degrees Celsius in the reducing atmosphere of hydrogen (hydrogen ventilation flow rate was 150 sccm), the heating time was 0.8h, the holding temperature was 650 degrees Celsius, and the holding time was 140min to obtain a blue-gray three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material.

[0039] Example 3: Lithium-ion battery negative electrode material of three-dimensional reduced conductive titanium dioxide tube

[0040] Weigh 5g of cotton and mix it with 400ml of 20% titanium trichloride aqueous solution by mass volume ratio and stir thoroughly for 6min;

[0041] The cotton was taken out from the reaction solution in the reaction vessel and filtered with a suction flask. The filtered cotton was placed in a CVD tube furnace and heated under an ammonia atmosphere (ammonia ventilation rate of 240 sccm) at a baking temperature of 250 degrees Celsius for 1.5 hours to obtain a white solid with a powdery texture;

[0042] The ammonia atmosphere of the CVD tube furnace was replaced with hydrogen, and the temperature was raised to 550 degrees Celsius in the reducing atmosphere of hydrogen (hydrogen ventilation flow rate was 80 sccm), the heating time was 1.5 hours, the holding temperature was 550 degrees Celsius, and the holding time was 100 minutes to obtain a blue-gray three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material.

[0043] Example 4: Lithium-ion battery negative electrode material of three-dimensional reduced conductive titanium dioxide tube

[0044] The preparation method is basically the same as that of Example 1, except that the preparation method of the white solid with powdery texture is different:

[0045] Thoroughly mixing cotton with anhydrous ethanol and tetrabutyl titanate, the cotton is taken out and drained, wherein the volume ratio of tetrabutyl titanate to anhydrous ethanol (v / v / v) is 1-5:200-300; and the weight-volume ratio of cotton to anhydrous ethanol (w / v, g / ml) is 1:25-75;

[0046] Soak the drained cotton in deionized water for 2 minutes, then take out the cotton and drain it, wherein the weight-to-volume ratio of cotton to deionized water (w / v, g / ml) is 1:25-75;

[0047] The dried cotton is placed in a high-temperature resistance furnace for heating and heat preservation to obtain a white solid with a powdery texture.

[0048] Example 5: Lithium-ion battery negative electrode material of three-dimensional reduced conductive titanium dioxide tube

[0049] The preparation method is basically the same as that of Example 1, except for the first CVD tube furnace treatment step:

[0050] (Example 5-1) In the first CVD tube furnace treatment step, the baking temperature was 180 degrees Celsius under an ammonia atmosphere (ammonia ventilation rate was 180 seem), and the heating time was 2 hours.

[0051] (Example 5-2) In the first CVD tube furnace treatment step, under an ammonia atmosphere (ammonia ventilation rate is 260 seem), the baking temperature is 290 degrees Celsius, and the heating time is 1.5 hours.

[0052] (Example 5-3) In the first CVD tube furnace treatment step, under an ammonia atmosphere (ammonia ventilation rate is 260 seem), the baking temperature is 190 degrees Celsius, and the heating time is 1.5 hours.

[0053] Example 6: Lithium-ion battery negative electrode material of three-dimensional reduced conductive titanium dioxide tube

[0054] The preparation method is basically the same as that of Example 1, except for the second CVD tube furnace treatment step:

[0055] (Example 6-1) In the second CVD tube furnace treatment step, the temperature of the CVD tube furnace was raised to 450 degrees Celsius under a reducing atmosphere of hydrogen (hydrogen flow rate of 60 seem), the heating time was 2 hours, and the holding temperature was 450 degrees Celsius for 150 minutes.

[0056] (Example 6-2) In the second CVD tube furnace treatment step, the temperature was raised to 700 degrees Celsius in a reducing atmosphere of hydrogen (hydrogen flow rate was 180 seem), the heating time was 0.8 hours, the holding temperature was 700 degrees Celsius, and the holding time was 80 minutes.

[0057] (Example 6-3) In the second CVD tube furnace treatment step, the temperature was raised to 500°C in a reducing hydrogen atmosphere (hydrogen flow rate of 160 sccm) for 1.2 hours, and then maintained at 500°C for 100 minutes.

[0058] The preparation method of the lithium ion battery negative electrode material of the three-dimensional reduced conductive titanium dioxide tube of Example 7 is basically the same as that of Example 1, except that:

[0059] In the second CVD tube furnace treatment step, an argon atmosphere was used.

[0060] The preparation method of the lithium ion battery negative electrode material of the three-dimensional reduced conductive titanium dioxide tube of Example 8 is basically the same as that of Example 1, except that:

[0061] When mixing cotton with the titanium trichloride aqueous solution, the cotton does not need to be torn into pieces.

[0062] The preparation method of the lithium ion battery negative electrode material of the three-dimensional reduced conductive titanium dioxide tube of Example 9 is basically the same as that of Example 1, except that:

[0063] When the cotton and titanium trichloride aqueous solution are mixed, no stirring is performed.

[0064] Comparative Example 1: Refer to the method of CN111517821A

[0065] Mix 5 ml of tetrabutyl titanate with 15 ml of anhydrous ethanol solution and stir thoroughly. Then, immerse a 4 cm long, 2 cm wide, and 1.5 cm high shredded cotton into the solution. Squeeze the shredded cotton to fully absorb the solution. Place the cotton in an 80°C oven for 1 hour to allow the ethanol to evaporate. Then, place the tetrabutyl titanate-soaked cotton in a CVD tube furnace and heat it to 800°C over 1 hour under an argon atmosphere. Hold the temperature for 2 hours to obtain the product.

[0066] Comparative Example 2 refers to the method of CN108325519A

[0067] 0.6 g of absorbent cotton is placed in 200 mL of anhydrous ethanol and stirred for 5 minutes, then 0.8 mL of 25% to 28% NH3·H2O is dropped into the mixture, and after ultrasonic treatment for 15 minutes, 0.15 mL of tetrabutyl titanate is added under stirring to obtain a mixed solution; the mixed solution is placed in a 45°C water bath and stirred for 12 hours, the absorbent cotton is removed from the mixed solution, first washed with ethanol 3 to 5 times and then with deionized water 3 to 5 times, and then dried at 50°C for 12 hours to obtain dry cotton, and the dry cotton is placed in a muffle furnace (air) and calcined at 500°C for 4 hours to obtain the product.

[0068] The technical effects of the present invention are described below with reference to test examples.

[0069] Experimental Example 1 Physical properties of lithium-ion battery negative electrode materials of three-dimensional reduced conductive titanium dioxide tubes

[0070] Examples 1 to 6 and Comparative Examples 1 to 2 were tested using a scanning electron microscope (SEM).

[0071] Table 1 Physical properties of three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material

[0072]

[0073]

[0074] The results show that:

[0075] 1) The diameter of the titanium dioxide tubes in Examples 1 to 6 is better than that in Comparative Examples 1 to 2. In Comparative Example 1, cotton is loaded with titanium dioxide and then treated in a CVD tube furnace. In Comparative Example 2, cotton is loaded with titanium dioxide in the presence of NH3·H2O and then treated in a muffle furnace. The diameter is higher than that in Examples 1 to 6, indicating that the mass volume ratio of the titanium trichloride aqueous solution is 15 to 20 wt%; the weight volume ratio of cotton to the titanium trichloride aqueous solution (w / v, g / ml) is 1:25 to 75; ammonia treatment in a CVD tube furnace; and hydrogen treatment in a CVD tube furnace are necessary conditions for obtaining a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube. Due to the superior diameter range of Examples 1 to 6 (6.7 to 20.2 μm), the effect of preventing uneven lithium deposition (lithium dendrite deposition) is significantly better than that in Comparative Examples 1 to 2. The better modification of the three-dimensional reduced conductive titanium dioxide tubes in the embodiments of the present invention can effectively reduce the lithium nucleation overpotential, enable uniform lithium deposition, and improve the coulombic efficiency and cycle life of the lithium ion battery.

[0076] 2) The diameter of the titanium dioxide tubes in Examples 1 to 3 is better than that in Examples 4 to 6. Example 4 uses tetrabutyl titanate as the titanium source. Examples 5-1, 5-2, and 5-3 adjust the first CVD tube furnace treatment conditions under an ammonia atmosphere. Experiments show that the main influencing factor of Example 5 is the ammonia flow rate. When the ammonia flow rate is within the specified range (200-240 sccm), the titanium dioxide tube wall produced is more uniform and dense; the temperature change within the specified range (200-280 degrees Celsius) has a relatively small effect on it. Examples 6-1, 6-2, and 6-3 adjust the second CVD tube furnace treatment conditions under a hydrogen atmosphere. Experiments show that the main influencing factor of Example 6 is the hydrogen flow rate. Within the safe flow range, the hydrogen flow rate is within the specified range (80-150 sccm), the more titanium dioxide produced, the better the conductivity, and the temperature change within the specified range (550-650 degrees Celsius) has a relatively small effect. This indicates that the conditions for loading cotton with titanium dioxide and the CVD tube furnace treatment produce a synergistic effect. This demonstrates that the preparation process of these embodiments of the present invention is simple, facilitating rapid and mass production of three-dimensional reduced conductive titanium dioxide tubes. The prepared three-dimensional titanium dioxide is reduced, and its composition is actually TiO2-X. Its performance as a battery negative electrode material is better than that of non-reduced titanium dioxide, resulting in higher conductivity and electron transfer rates. The raw material costs are also low, with titanium trichloride and water being significantly cheaper than the titanium source tetrabutyl titanate and solvent alcohol used in other titanium dioxide preparation methods.

[0077] Although CN104766963A discloses a method for preparing a metal oxide-carbon fiber nanocomposite material using titanium trichloride and natural cotton in a nitrogen furnace, this method cannot prepare the three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material of the present invention. In the embodiment of the present invention, the first CVD tube furnace is calcined in an ammonia atmosphere to load titanium dioxide onto the uncarbonized cotton fiber to form a titanium dioxide tube wall. The pH is not adjusted in the liquid phase, but the reaction is carried out in the gas phase. Titanium dioxide is directly loaded on the cotton fiber, which can make the formed titanium dioxide tube wall more uniform and dense. The second CVD tube furnace is in a hydrogen atmosphere to carbonize the cotton fiber in the material while reducing part of the titanium dioxide to titanium trioxide, thereby improving the conductivity of the material and increasing the electron transfer rate, thereby preparing a three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material.

[0078] The results of repeated tests using Examples 7 to 9 show that: in Example 7, an argon atmosphere was used in the CVD tube furnace treatment step; Example 8 used unshredded cotton; and Example 9 did not stir. The diameter of the titanium dioxide tube increased, but the effect was relatively small.

[0079] Test Example 2 Lithium-ion Battery Performance Test

[0080] The test method is to use the three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material of Examples 1 to 3 and Comparative Examples 1 to 2, and use the prepared three-dimensional reduced conductive titanium dioxide tube material as the negative electrode active material to make a Li-Cu half-cell, and perform the following performance tests, see Table 2 and Figure 1 Corresponding to the cycle performance of Example 1, Figure 2 Corresponding to the SEM image of Example 1, Figure 3 Corresponding to the SEM image of Example 2.

[0081] Table 2 Lithium-ion battery performance test

[0082] Coulomb efficiency Cycle performance (h / cycle) Example 1 99.3％ 1260 / 315 Example 2 98.6％ 1080 / 270 Example 3 97.8％ 1148 / 287 Comparative Example 1 97.9％ 940 / 235 Comparative Example 2 98.4％ 896 / 224

[0083] Note: h stands for hour.

[0084] The results show that:

[0085] 1) The Coulomb effects of Examples 1 to 3 are slightly better than those of Comparative Examples 1 to 2, wherein the Coulomb effect of Example 1 is better than that of Comparative Examples 1 to 2 by about 1%.

[0086] 2) The cycle performance (h / cycle) of Examples 1 to 3 is significantly better than that of Comparative Examples 1 to 2. Combined with the test results of the Coulomb effect, it can be seen that the lithium-ion battery prepared using the lithium-ion battery negative electrode material of the three-dimensional reduced conductive titanium dioxide tube of Examples 1 to 3 has an overall better performance than that of Comparative Documents 1 to 2.

[0087] The results of Examples 7 to 9 show that the lithium-ion battery performance of Examples 1 to 3 is better than that of Examples 7 to 9. Among them, in Example 7, the cotton that was not torn was used. Although the performance of the lithium-ion battery decreased, the impact on the coulombic efficiency and cycle performance (h / cycle) was relatively small; in Example 8, there was no stirring, and the impact on the coulombic efficiency was relatively small, but the cycle performance (h / cycle) decreased by about 5%; in Example 9, an argon atmosphere was used in the CVD tube furnace treatment step, which had a relatively small impact on the coulombic efficiency, but caused the cycle performance (h / cycle) to decrease by about 4%.

[0088] In summary, the three-dimensional reduced conductive titanium dioxide tubes offer improved conductivity, effectively promoting charge transfer efficiency and uniform charge distribution during electrochemical reactions. They also effectively prevent lithium dendrite deposition, improving coulombic efficiency and cycle life. Three-dimensional titanium dioxide tubes exhibit excellent mechanical properties and, in a reducing atmosphere, produce trace amounts of titanium trioxide and other titanium oxides, which can effectively modify lithium metal. Furthermore, the simple manufacturing process, low heating temperature and energy consumption, and inexpensive raw materials make them suitable for large-scale mass production.

[0089] Although the present invention has been described in detail above using general explanations, specific embodiments, and experiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A method for preparing a three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material, comprising the following steps: The cotton is mixed with the titanium trichloride aqueous solution and then the cotton is taken out and dried. The mass volume ratio of the titanium trichloride aqueous solution is 15-20 wt%; the weight volume ratio of the cotton to the titanium trichloride aqueous solution w / v, g / ml = 1:25-75; The dried cotton was placed in a CVD tube furnace and heated in an ammonia atmosphere to obtain powder with an ammonia flow rate of 200-240 sccm; The atmosphere of the CVD tube furnace is changed to a hydrogen reducing atmosphere, and the temperature is increased and maintained to obtain a three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material, with a hydrogen ventilation flow rate of 80 to 150 sccm; The baking temperature of the CVD tube furnace under ammonia atmosphere is 200-280 degrees Celsius, and the heating time is 0.8-1.5 hours; The baking temperature of the CVD tube furnace under hydrogen atmosphere is 550-650 degrees Celsius, the heating time is 0.8-1.5 hours, the holding temperature is 550-650 degrees Celsius, and the holding time is 100-140 minutes.

2. The method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube according to claim 1, wherein: The mass volume ratio of the titanium trichloride aqueous solution is 17.5 wt%.

3. The method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube according to claim 1, wherein: The weight-to-volume ratio of cotton to titanium trichloride aqueous solution (w / v, g / ml) is 1:

50.

4. The method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube according to claim 1, wherein: The baking temperature of the CVD tube furnace under the ammonia atmosphere is 240 degrees Celsius, and the heating time is 1 hour.

5. The method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube according to claim 4, wherein: The ammonia flow rate was 220 sccm.

6. The method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube according to claim 1, wherein: The baking temperature of the CVD tube furnace under the hydrogen atmosphere is 600 degrees Celsius, the heating time is 1 hour, and the heat preservation time is 600 degrees Celsius for 120 minutes.

7. The method for preparing a lithium ion battery negative electrode material of a three-dimensional reduced conductive titanium dioxide tube according to claim 6, wherein: The hydrogen gas flow rate was 110 sccm.

8. The method for preparing a three-dimensional reduced conductive titanium dioxide tube as claimed in claim 7, wherein the step of thoroughly mixing the cotton with the titanium trichloride aqueous solution and then removing the cotton and draining it comprises: The cotton and the titanium trichloride aqueous solution are fully stirred for 5 to 10 minutes, the cotton is taken out from the solution, and filtered with a suction filtration bottle to obtain filtered cotton.

9. The method for preparing a three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material according to claim 8, wherein the cotton and the titanium trichloride aqueous solution are fully stirred for 8 minutes.

10. A three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material, characterized in that: The three-dimensional reduced conductive titanium dioxide tube lithium ion battery negative electrode material is prepared by the method according to any one of claims 1 to 9.

11. A lithium ion battery negative electrode, wherein the lithium ion battery negative electrode is prepared from the lithium ion battery negative electrode material of the three-dimensional reduced conductive titanium dioxide tube according to claim 10.

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