CN117558894A - Preparation method and application of a simple pre-lithiated nanostructured silicon-oxygen carbon composite material - Google Patents
Preparation method and application of a simple pre-lithiated nanostructured silicon-oxygen carbon composite material Download PDFInfo
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Abstract
本发明公开了一种简单预锂化纳微结构硅氧碳复合材料的制备方法及其应用，将SiOx材料与锂源放入有机溶剂中混合搅拌均匀之后将有机溶剂蒸干。将混合物放入CVD回转炉中，开启一定的转速，在氩气气氛下加热保温进行预锂化反应；将所述预锂化的Pre‑Li‑SiOx材料继续在CVD回转炉中升温后进行碳沉积包覆，经过洗涤、抽滤、干燥得到预锂化纳微结构硅氧碳复合材料。本发明采用一锅法制备的材料均匀性和一致性较好；将动态预锂化和碳沉积包覆有效结合；增强了材料的导电性，减少材料的表面极化，使其形成稳定的SEI膜，提高了电池的首次库伦效率，改善了材料的循环稳定性能，在锂离子电池负极材料中具有广阔的应用前景。
The invention discloses a preparation method and application of a simple pre-lithiated nano-microstructure silicon-oxycarbon composite material. The SiOx material and the lithium source are put into an organic solvent, mixed and stirred evenly, and then the organic solvent is evaporated to dryness. Put the mixture into a CVD rotary furnace, turn on a certain rotation speed, and heat and maintain the temperature under an argon atmosphere to perform a pre-lithiation reaction; continue to heat the pre-lithiated Pre-Li-SiOx material in the CVD rotary furnace and then carbonize. After deposition and coating, washing, suction filtration and drying are performed to obtain the pre-lithiated nano-microstructure silicon-oxycarbon composite material. The material prepared by the one-pot method of the present invention has better uniformity and consistency; it effectively combines dynamic prelithiation and carbon deposition coating; it enhances the conductivity of the material, reduces the surface polarization of the material, and enables it to form a stable SEI The membrane improves the first Coulombic efficiency of the battery, improves the cycle stability of the material, and has broad application prospects in lithium-ion battery anode materials.
Description
Technical Field
The invention relates to the technical field of lithium ion battery cathode materials, in particular to a preparation method and application of a simple pre-lithiated nano-microstructure silicon-oxygen-carbon composite material.
Background
Lithium Ion Batteries (LIBs) have become the main energy storage devices of electric vehicles due to the advantages of high energy density, wide operating temperature range, no memory effect and the like. Along with the improvement of the energy density requirement of the lithium ion battery, the energy density and the electrochemical performance of the cathode material are correspondingly improved.
Low lithium-removing potential of silicon factor<0.5V), and a high theoretical capacity (Li at room temperature 15 Si 4 The phase capacity is 3590mAh g -1 ) The advantages of environmental friendliness, abundant reserves, lower cost and the like have been evaluated as the negative electrode material of the next-generation lithium ion battery. But so far it has not been applied in large scale as a primary active material in practical batteries. This is mainly that Si undergoes structural transformation during the initial lithiation of silicon, that crystalline Si (c-Si) is transformed into amorphous LixSi, and that it is further transformed into amorphous Si (a-Si) during the initial delithiation. Anisotropic expansion and contraction during lithium intercalation and deintercalation occur, and the volume change rate is large (for Li 4.4 Si about 360%); the huge volume expansion can lead to pulverization of materials, repeated growth of SEI films, separation from a current collector and rapid capacity decay, and severely limits practical application thereof. Second, intrinsic conductivity of SiLow (< 10) -3 S/cm,25 ℃). Silicon oxides (SiOx) of different silicon and oxygen content do not have severe volume changes of pure silicon. The oxygen is introduced into SiOx such that it forms inert components, such as Li, in the first deintercalation of lithium 2 O and lithium silicate are beneficial to reducing the volume change in the lithiation process. But Li 2 O and lithium silicate, the formation of inactive products also results in partial Li deactivation, reducing the first coulombic efficiency.
The pre-lithiation and carbon coating can effectively improve the first coulombic efficiency of SiOx, improve the conductivity of the material and relieve the volume expansion of SiOx. The existing SiOx pre-lithiation and carbon coating are mostly divided into two steps or even multiple steps, the SiOx is mostly pre-lithiated by mixing SiOx with a lithium source solid phase and heating the mixture to a temperature above the melting point of the lithium source, then the material is washed and dried, and then the material is subjected to carbon coating, the methods are complicated, in the pre-lithiation process, the material is mostly in a static state all the time, and the uniformity and consistency of the material cannot be ensured due to the different pre-lithiation temperatures in the experimental process.
Therefore, the simple, uniform and controllable pre-lithiated carbon coated nano-microstructure silicon-oxygen-carbon composite material and the preparation method thereof are provided, so that the application value of the SiOx material in the negative electrode material of the lithium ion battery is comprehensively improved, and the problem to be solved by the person skilled in the art is needed to be solved.
Disclosure of Invention
Based on the technical problems in the background technology, the invention provides a preparation method and application of a simple pre-lithiated nano-microstructure silicon-oxygen-carbon composite material. The preparation method adopts a one-pot method, and the required experimental equipment is simple and easy to operate; the experimental procedure is simple. The prepared material has better uniformity and consistency; the material has higher first effect, good conductivity and cycle performance. The preparation method effectively combines dynamic prelithiation and carbon deposition coating; the material has the advantages of enhancing the conductivity, reducing the surface polarization of the material, enabling the material to form a stable SEI film, improving the first coulomb efficiency of the battery, improving the cycling stability of the material, and having wide application prospect in the lithium ion battery cathode material.
In order to solve the technical problems, the invention adopts the following technical scheme:
the invention provides a preparation method of a simple pre-lithiated nano-microstructure silicon-oxygen-carbon composite material, which comprises the following steps:
s1, placing SiOx materials (x is more than 0 and less than or equal to 2) and lithium sources such as lithium hydroxide into an organic solvent, uniformly mixing and stirring, and then evaporating the organic solvent. Putting the mixture into a CVD rotary furnace, starting a certain rotating speed, heating to a pre-lithiation temperature in an argon atmosphere, and preserving heat to perform a pre-lithiation reaction; obtaining a Pre-lithiated SiOx material, labeled as Pre-Li-SiOx; and directly continuously heating or cooling the Pre-lithiated Pre-Li-SiOx material in a CVD rotary furnace with a certain rotating speed to a deposition coating temperature, and then introducing gases such as an organic carbon source and the like to carry out carbon deposition coating to obtain a Pre-lithiated carbon deposition coated nano-microstructure silicon-oxygen-carbon composite material, wherein the Pre-Li-SiOx@C is marked.
S2, washing, suction filtering and drying the Pre-Li-SiOx@C composite material to obtain the Pre-lithiated nano-microstructure silicon-oxygen-carbon composite material.
In the step S1, the lithium source is one or more of metal lithium powder, lithium hydroxide, lithium carbonate, lithium nitrate, lithium acetate, lithium iodide and lithium stearate.
In S1, the mass ratio of SiOx to lithium source is (10-50) 1, x is more than 0 and less than or equal to 2.
In the step S1, the organic solvent is one or more of methanol, ethanol, acetone, diethyl ether and dimethylformamide.
Further, in S1, the rotational speed of the CVD rotary furnace is 10 to 60 revolutions per minute.
In S1, the temperature rising rate of the pre-lithiation is 2-10 ℃/min, the pre-lithiation temperature is 700-850 ℃, and the heat preservation time is 0-60min.
Further, the organic carbon source gas in the S1 is a mixed gas composed of organic gas and argon gas in a volume ratio of 1 (1-20), and the organic gas is one or more of methane, ethane, ethylene and acetylene.
Further, the CVD carbon coating is carried out in the S1, the heating rate is 2-10 ℃/min, the carbon deposition coating temperature is 700-900 ℃, and the coating time is 10-120min.
Further, the washing solvent in S2 is water and ethanol, the washing is carried out until the solution is neutral, and the drying temperature is 50-100 ℃.
Preferably, in S1, the average particle size D of SiOx 50 The mass ratio of SiOx to lithium source was 30:1 at 5 μm.
Preferably, in S1, the organic solvent is ethanol and is evaporated to dryness at 80 ℃.
Preferably, in S1, the rotational speed of the CVD rotary kiln is 40 revolutions per minute.
Preferably, in S1, the pre-lithiation is performed in an argon atmosphere at a temperature rising rate of 5 ℃/min, the pre-lithiation temperature is 800 ℃, and the pre-lithiation time is 30min.
Preferably, in S1, the organic carbon source gas is acetylene, and the volume ratio of the organic carbon source gas to the argon is 1:6.
Preferably, in S1, CVD carbon is deposited and coated, the heating rate is 5 ℃/min, the coating temperature is 800 ℃, and the coating time is 20min.
Preferably, in S2, the washing solvent is water, and the washing solvent is washed for 3-5 times until the solution is neutral, and the drying temperature is 60 ℃.
The invention also provides application of the pre-lithiated nano-microstructure composite material prepared by the preparation method as a lithium ion battery anode material.
Compared with the prior art, the invention has the following beneficial technical effects:
1. the invention carries out one-pot dynamic prelithiation and carbon deposition coating on SiOx. The required experimental equipment is simple, the operation is easy, and the preparation method is simple. In the processes of prelithiation and carbon deposition coating, the materials are always in a rotary motion state, and the prepared materials are better in uniformity and consistency. The prepared material has higher initial effect, good conductivity and cycle performance.
2. The preparation method ensures that the pre-lithiation is more uniform and controllable compared with the solid phase mixed contact. Pre-lithiation enables SiOx to generate a small amount of Si nano microcrystal to form a nano microstructure, thereby being beneficial to improving the first coulomb efficiency of the material; the carbon deposition coating improves the conductivity of the material, relieves volume expansion and improves the circulation stability; the electrochemical performance of the lithium battery is comprehensively improved by the synergistic effect of the prelithiation and the carbon deposition coating.
Drawings
Fig. 1 is an SEM image of SiOx powder used in the examples of the present invention.
Fig. 2 shows the XRD pattern of the raw material SiOx of the present invention.
Figure 3 XRD patterns of the materials prepared in example 1 and example 4.
FIG. 4 is an XRD pattern of the materials obtained in comparative examples 4 to 6.
Fig. 5 is a charge-discharge curve of the material according to the present invention using SiOx and example 1.
Detailed Description
The following examples are given to illustrate the invention in detail, but are not intended to limit the scope of the invention in any way.
The invention is further illustrated below with reference to examples. The raw materials used in the examples were commercially available conventional raw materials unless otherwise specified.
As shown in FIG. 1, an SEM image of SiOx powder used in the examples shows that the SiOx powder has a size of 4-8 μm and a SiOx particle diameter D from FIG. 1 50 Is 5 μm and has a smooth surface.
The XRD patterns of the SiOx powders used in the examples are shown in FIG. 2, and for the SiOx samples used, there are only two relatively broad "steamed bread" peaks around 15-35℃and 50℃and no distinct crystal peaks are observed, indicating that SiOx is amorphous.
Example 1
A preparation method of a simple prelithiation nano-microstructure silicon-oxygen-carbon composite material comprises the following specific steps:
the SiOx powder and lithium hydroxide with the mass ratio of 30:1 are put into 30ml of ethanol to be mixed and stirred uniformly, and then the ethanol is evaporated to dryness. The mixture was placed in a CVD rotary kiln at a rotary kiln speed of 40 revolutions per minute. And introducing high-purity argon, heating to 800 ℃ at a heating rate of 5 ℃/min at an air flow rate of 200mL/min, preserving heat for 30min to obtain prelithiated SiOx (marked as Pre-Li-SiOx-800 ℃), then introducing argon and acetylene mixed gas with a volume ratio of 6:1 into a CVD rotary furnace, continuously carrying out CVD carbon deposition coating at 800 ℃ for 20min, cooling, taking out, washing with water to neutral pH, and drying at 60 ℃. Obtaining a pre-lithiated nano-microstructure silicon-oxygen-carbon composite material; marked as Pre-Li-SiOx@C-800 ℃.
Example 2
A preparation method of a simple prelithiation nano-microstructure silicon-oxygen-carbon composite material comprises the following specific steps:
SiOx powder and lithium hydroxide with the mass ratio of 30:1 are put into 30ml of methanol to be mixed and stirred uniformly, and then the methanol is evaporated to dryness. The mixture was placed in a CVD rotary kiln at a rotary kiln speed of 40 revolutions per minute. And introducing high-purity argon, the air flow rate is 200mL/min, heating to 800 ℃ at the heating rate of 5 ℃/min, preserving heat for 30min to obtain prelithiated SiOx (marked as Pre-Li-SiOx-800-A), then introducing argon and acetylene mixed gas with the volume ratio of 6:1 into a CVD rotary furnace, continuously carrying out CV D carbon deposition coating at 800 ℃ for 20min, cooling, taking out, washing with water to neutral pH, and drying at 60 ℃. Obtaining a pre-lithiated nano-microstructure silicon-oxygen-carbon composite material; marked as Pre-Li-SiOx@C-800-A.
Example 3
A preparation method of a simple prelithiation nano-microstructure silicon-oxygen-carbon composite material comprises the following specific steps:
the SiOx powder and lithium hydroxide with the mass ratio of 30:1 are put into 30ml of ethanol to be mixed and stirred uniformly, and then the ethanol is evaporated to dryness. The mixture was placed in a CVD rotary kiln at a rotary kiln speed of 60 revolutions per minute. And introducing high-purity argon, the air flow rate is 200mL/min, heating to 800 ℃ at the heating rate of 5 ℃/min, preserving heat for 30min to obtain prelithiated SiOx (marked as Pre-Li-SiOx-800-B), then introducing argon and acetylene mixed gas with the volume ratio of 6:1 into a CVD rotary furnace, continuously carrying out CVD carbon deposition coating at 800 ℃ for 20min, cooling, taking out, washing with water to neutral pH, and drying at 60 ℃. Obtaining a pre-lithiated nano-microstructure silicon-oxygen-carbon composite material; marked as Pre-Li-SiOx@C-800-B.
Example 4
A preparation method of a simple prelithiation nano-microstructure silicon-oxygen-carbon composite material comprises the following specific steps:
the SiOx powder and lithium hydroxide with the mass ratio of 30:1 are put into 30ml of ethanol to be mixed and stirred uniformly, and then the ethanol is evaporated to dryness. The mixture was placed in a CVD rotary kiln at a rotary kiln speed of 40 revolutions per minute. And introducing high-purity argon, heating to 700 ℃ at a heating rate of 5 ℃/min at an air flow rate of 200mL/min, preserving heat for 30min to obtain prelithiated SiOx (marked as Pre-Li-SiOx-700 ℃), heating to 800 ℃ from 700 ℃ at a heating rate of 5 ℃/min in a CVD rotary furnace, introducing argon and acetylene mixed gas with a volume ratio of 6:1, carrying out CVD carbon deposition coating for 20min, cooling, taking out, washing with water to neutral pH, and drying at 60 ℃. Obtaining a pre-lithiated nano-microstructure silicon-oxygen-carbon composite material; marked as Pre-Li-SiOx@C-700 ℃.
The XRD characterization results of the prelithiated nano-microstructured siloxycarbon composites prepared in example 1 and example 4 are shown in fig. 3, and no significant diffraction peak of Si was observed in example 4, indicating that no significant disproportionation reaction of prelithiation and carbon deposit coating occurred at this temperature. The XRD pattern of example 1 showed that diffraction peaks of Si (PDF # 27-1402) were generated, and weak SiO was observed 2 (PDF # 89-3608) and Li 2 SiO 3 (PDF # 29-0828) diffraction peaks; indicating that there is a small amount of Li in the product formed by pre-lithiation 2 SiO 3 While the carbon coating is amorphous carbon.
Comparative example 1
The comparative example performs two-step pre-lithiated carbon coating on SiOx, and comprises the following specific steps:
(1) The SiOx powder and lithium hydroxide with the mass ratio of 30:1 are put into 30ml of ethanol to be mixed and stirred uniformly, and then the ethanol is evaporated to dryness. Placing the mixture into a tube furnace, introducing high-purity argon, heating the mixture from room temperature to 800 ℃ at a heating rate of 5 ℃/min at a gas flow rate of 200mL/min, and preserving heat for 30min to obtain pre-lithiated SiOx; cooling, taking out, washing until pH is neutral, and drying at 60 ℃; marked as Pre-Li-SiOx-800 deg.c-2.
(2) Placing the prelithiated SiOx in the step (1) in a tube furnace, introducing argon, heating to 800 ℃ from room temperature at a heating rate of 5 ℃/min, introducing argon and acetylene mixed gas with a volume ratio of 6:1, carrying out carbon coating for 20min, and cooling and taking out. Obtaining a pre-lithiated nano-microstructure silicon-oxygen-carbon composite material; marked as Pre-Li-SiOx@C-800-2.
Comparative example 2
The comparative example performs a pre-lithiation solid phase mixed carbon deposition coating on SiOx, and comprises the following specific steps:
the SiOx powder and lithium hydroxide solid with the mass ratio of 30:1 are directly stirred and mixed. The mixture was placed in a CVD rotary kiln at a rotary kiln speed of 40 revolutions per minute. Introducing high-purity argon, heating to 800 ℃ at a heating rate of 5 ℃/min at an air flow rate of 200mL/min, and preserving heat for 30min to obtain pre-lithiated SiOx; marked as Pre-Li-SiOx-800-3.
And (3) continuously placing the Pre-Li-SiOx-800-3 in a CVD rotary furnace, then introducing argon and acetylene mixed gas with the volume ratio of 6:1, carrying out CVD carbon deposition coating for 20min, cooling, taking out, washing with water to be neutral in PH, and drying at 60 ℃. Obtaining a pre-lithiated nano-microstructure silicon-oxygen-carbon composite material; marked as Pre-Li-SiOx@C-800-3.
Comparative example 3
The SiOx is only coated by carbon deposition, and the specific steps are as follows:
5g of SiOx powder was weighed and placed in a CVD rotary kiln at a rotary speed of 40 rpm. And introducing high-purity argon, heating to 800 ℃ at a heating rate of 5 ℃/min at an air flow rate of 200mL/min, then introducing argon and acetylene mixed gas with a volume ratio of 6:1, carrying out CVD carbon deposition coating for 20min, and taking out after cooling to obtain the SiOx@C composite material.
Comparative example 4
The comparative example only prelithiation of SiOx was performed, specifically as follows:
the SiOx powder and lithium hydroxide with the mass ratio of 30:1 are put into 30ml of ethanol to be mixed and stirred uniformly, and then the ethanol is evaporated to dryness. The mixture was placed in a CVD rotary kiln at a rotary kiln speed of 40 rpm. Introducing high-purity argon, heating to 800 ℃ at a heating rate of 5 ℃/min at an air flow rate of 200mL/min, preserving heat for 30min, cooling, taking out, washing with water to neutral pH, and drying at 60 ℃ to obtain pre-lithiated SiOx; marked Pre-Li-SiOx-800 ℃.
Comparative example 5
The comparative example increases the pre-lithiation temperature as follows:
the SiOx powder and lithium hydroxide with the mass ratio of 30:1 are put into 30ml of ethanol to be mixed and stirred uniformly, and then the ethanol is evaporated to dryness. The mixture was placed in a CVD rotary kiln at a rotary kiln speed of 40 rpm. Introducing high-purity argon, heating to 900 ℃ at a heating rate of 5 ℃/min at an air flow rate of 200mL/min, preserving heat for 30min, cooling, taking out, washing with water to neutral pH, and drying at 60 ℃ to obtain pre-lithiated SiOx; marked Pre-Li-SiOx-900 ℃.
Comparative example 6
The comparative example reduces the pre-lithiation temperature as follows:
the SiOx powder and lithium hydroxide with the mass ratio of 30:1 are put into 30ml of ethanol to be mixed and stirred uniformly, and then the ethanol is evaporated to dryness. The mixture was then placed in a CVD rotary kiln at a rotary kiln speed of 40 revolutions per minute. Introducing high-purity argon, heating to 700 ℃ at a heating rate of 5 ℃/min at an air flow rate of 200mL/min, preserving heat for 30min, cooling, taking out, washing with water to neutral pH, and drying at 60 ℃ to obtain pre-lithiated SiOx; marked Pre-Li-SiOx-700 ℃.
XRD characterization results of the materials obtained in comparative example 4 and comparative examples 5 and 6, as shown in FIG. 4, XRD patterns of comparative example 4 and comparative example 5 showed that diffraction peaks of Si (PDF # 27-1402) were generated, and weak SiO was detected 2 (PDF # 89-3608) and Li 2 SiO 3 (PDF # 29-0828) diffraction peaks; indicating that the product formed by prelithiation has a small amount of Li 2 SiO 3 And as the temperature increases, the diffraction peak of the crystalline silicon is gradually enhanced, and more impurity peaks appear at the same time, which indicates that the pre-lithiation at 900 ℃ can lead to the growth of silicon grains inside the SiOx. Comparative example 6 does not observe a significant diffraction peak of Si, and is maintained with the XRD pattern of the raw material SiOConsistent, it is shown that at this temperature, no significant disproportionation of SiOx occurs, and to some extent, that the internal microstructure retains the original structure at lower temperatures.
The composite materials obtained in examples 1 and 4 and comparative examples 1 and 2 were used as negative electrode active materials for lithium ion batteries, and electrochemical performance tests were performed as follows:
mixing the prepared active substance with a conductive agent, wherein the conductive agent is Super P, the binder is CMC and SBR (mass ratio is 6:4), coating the mixture on a copper foil, and performing vacuum drying on a pole piece at 100 ℃ for 12 hours to obtain a wafer with the diameter of 12 mm. Lithium foil is used as a counter electrode, and the electrolyte is 1M LiPF 6 Dissolved in EC+DMC (volume ratio 1:1) solvent, celgard 2500 membrane; the CR2025 button half cell was assembled in a glove box. And after the assembled battery is static for 10 hours at room temperature, performing constant-current charge and discharge test on the Wuhan blue electro-chemical test channel, wherein the current density is 0.1 ℃, the charge cut-off voltage is 2.00V, and the discharge cut-off voltage is 0.005V.
The samples prepared in examples 1 and 4 and comparative examples 1 and 2 were assembled into a battery to perform a charge and discharge test, and the test results are shown in table 1:
TABLE 1
It can be seen from table 1 that the first coulombic efficiency was improved for both examples 1 and 2 compared to comparative examples 1 and 2.
The first charge and discharge curves of the assembled button half cell of example 1 are shown in fig. 5. As can be seen from fig. 5, the pure SiOx material has a first discharge capacity of 2195.62mAh/g and a charge capacity of 1529.14mAh/g at a current density of 0.1C. The first coulombic efficiency is only 69.64%. For the nano-microstructure silicon-oxygen-carbon composite material prepared in the example 1, the first discharge capacity is 1674.22mAh/g, the charge capacity is 1485.5mAh/g, and the first coulomb efficiency can reach 88.73%. The analytical reason is that the addition of the lithium source in example 1 forms lithium silicate in advance during the pre-lithiation process, while nano-crystallite Si is formed at the pre-lithiation temperature of 800 ℃. The carbon deposition coating layer is favorable for charge transfer, so that lithium ions are easier to insert and extract, and meanwhile, the carbon coating layer can effectively stabilize a solid-liquid interface between an electrode material and electrolyte, so that the first coulomb efficiency is remarkably improved.
Therefore, the preparation method effectively combines the pre-lithiated carbon deposition coating by using a one-pot method, and the prepared nano-microstructure silicon-oxygen-carbon composite material has higher initial coulomb efficiency, excellent conductivity and stable cycle performance. The method is simple and controllable, and the pre-lithiation generates the irreversible Li in advance by co-heating SiOx and a lithium source 2 SiO 3 Meanwhile, a small amount of Si nano microcrystals can be generated, so that the first coulomb efficiency of the lithium battery anode material is improved; the carbon deposition coating layer is favorable for charge transfer, so that lithium ions are easier to insert and extract, and meanwhile, the carbon coating layer can effectively stabilize a solid-liquid interface between the electrode material and the electrolyte, relieve volume expansion and improve conductivity, so that the electrochemical performance of the composite material is improved.
The above embodiments are only for illustrating the technical solution of the present invention, but not for limiting, and other modifications and equivalents thereof by those skilled in the art should be included in the scope of the claims of the present invention without departing from the spirit and scope of the technical solution of the present invention.
Claims (10)
1. The preparation method of the simple prelithiation nano-microstructure silicon-oxygen-carbon composite material is characterized by comprising the following steps of:
s1, placing SiOx material and a lithium source into an organic solvent, mixing and stirring uniformly, evaporating the organic solvent to obtain a mixture, placing the mixture into a CVD rotary furnace, starting a certain rotating speed, heating to a pre-lithiation temperature in an argon atmosphere, and preserving heat to perform a pre-lithiation reaction; obtaining a Pre-lithiated SiOx material, wherein x is more than 0 and less than or equal to 2, and is marked as Pre-Li-SiOx; directly heating the obtained Pre-lithiated Pre-Li-SiOx material in a CVD rotary furnace with a certain rotating speed to a carbon deposition coating temperature, and then introducing organic carbon source gas to carry out carbon deposition coating to obtain a Pre-lithiated carbon deposition coated nano-microstructure silicon-oxygen-carbon composite material, wherein the Pre-Li-SiOx@C is marked;
s3, washing, suction filtering and drying the obtained Pre-Li-SiOx@C composite material to obtain the Pre-lithiated nano-microstructure silicon-oxygen-carbon composite material.
2. The method for preparing a pre-lithiated nano-microstructure silicon-oxygen-carbon composite material according to claim 1, wherein in S1, the lithium source is one or more of metal lithium powder, lithium hydroxide, lithium carbonate, lithium nitrate, lithium acetate, lithium iodide, and lithium stearate.
3. The method for preparing a pre-lithiated nano-microstructure silicon-oxygen-carbon composite material according to claim 1, wherein in S1, the mass ratio of SiOx to lithium source is (10-50) 1,0 < x.ltoreq.2.
4. The method for preparing a prelithiation nano-micro structured silicon-oxygen-carbon composite material according to claim 1, wherein in the step S1, the organic solvent is one or more of methanol, ethanol, acetone, diethyl ether and dimethylformamide.
5. The method for preparing a prelithiated nano-microstructured silica-carbon composite material according to claim 1, wherein in S1, the rotation speed of the CVD rotary furnace is 10-60 rpm.
6. The preparation method and the application of the pre-lithiated nano-microstructure silicon-oxygen-carbon composite material according to claim 1, wherein in S1, the temperature rising rate of the pre-lithiation is 2-10 ℃/min, the pre-lithiation temperature is 700-850 ℃, and the heat preservation time is 0-60min.
7. The preparation method and the application of the prelithiation nano-microstructure silicon-oxygen-carbon composite material are characterized in that the organic carbon source gas in S1 is mixed gas composed of organic gas and argon gas in a volume ratio of 1 (1-20), and the organic gas is one or more of methane, ethane, ethylene and acetylene.
8. The preparation method and the application of the prelithiation nano-microstructure silicon-oxygen-carbon composite material as claimed in claim 1, wherein the CVD carbon coating is carried out in S1, the heating rate is 2-10 ℃/min, the carbon deposition coating temperature is 700-900 ℃, and the coating time is 10-120min.
9. The method for preparing the prelithiation nano-microstructure silicon-oxygen-carbon composite material and the application thereof according to claim 1, wherein the washing solvent in the step S2 is water and ethanol, the washing is carried out until the solution is neutral, and the drying temperature is 50-100 ℃.
10. Use of the pre-lithiated nano-microstructure composite material prepared by the preparation method of claims 1-9 as a lithium ion battery negative electrode material.
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