Method for prelithiation of silicon-based negative electrode material and prelithiated silicon-based negative electrode material

Abstract

The application discloses a method for prelithiation of a silicon-based negative electrode material and a prelithiated silicon-based negative electrode material. The method comprises the following steps: a coating step for coating a ceramic layer on the surface of Si powder or SiOx powder to obtain ceramic layer coated particles, wherein 0 < x < 2; a mixing step for mixing the ceramic layer coated particles with metal lithium powder to obtain a mixture; and a heat treatment step for heat treating the mixture to lithiate the Si powder or SiOx powder, thereby obtaining the prelithiated silicon-based negative electrode material. The method for prelithiation of the silicon-based negative electrode material is simple in operation and good in repeatability, thus overcoming the defects of the existing prelithiation technology, i.e., immaturity and complicated operation, and having important application value in negative electrode materials of lithium ion batteries and the like.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a method for pre-lithiation of a silicon-based negative electrode material and a pre-lithiation silicon-based negative electrode material. Background Art

[0002] Secondary batteries, represented by lithium-ion secondary batteries, are high-capacity, long-life, environmentally friendly batteries with many advantages such as high voltage, high specific energy, long cycle life, good safety performance, low self-discharge, no memory effect, fast charging and discharging, and a wide operating temperature range. They are widely used in energy storage, electric vehicles, portable electronic products and other fields.

[0003] During the first charge of a lithium-ion battery, the organic electrolyte will be reduced and decomposed on the surface of the negative electrode, such as graphite, to form a solid electrolyte interface (SEI) film, which permanently consumes a large amount of lithium from the positive electrode, resulting in a low coulombic efficiency in the first cycle and reducing the capacity and energy density of the lithium-ion battery. To solve this problem, people have studied pre-lithiation technology, which replenishes lithium in the electrode material through pre-lithiation to offset the irreversible lithium loss caused by the formation of the SEI film, thereby increasing the total capacity and energy density of the battery. However, existing traditional pre-lithiation technology is immature and complex to operate, making it difficult to meet actual usage needs. Summary of the Invention

[0004] The present application provides a method for pre-lithiation of silicon-based negative electrode materials and a pre-lithiation silicon-based negative electrode material that are simple to operate, have good repeatability, and can increase the total capacity of a battery.

[0005] In a first aspect, the present application provides a method for pre-lithiation of a silicon-based negative electrode material, comprising:

[0006] The coating step is used to coat the surface of Si powder or SiOx powder with a ceramic layer to obtain ceramic layer coated particles, wherein 0 <x<2;

[0007] a mixing step for mixing the ceramic layer coated particles with the metallic lithium powder to obtain a mixture;

[0008] The heat treatment step is used to heat treat the mixture to lithiate the Si powder or SiOx powder to obtain a pre-lithiated silicon-based negative electrode material.

[0009] According to any embodiment of the first aspect of the present application, the coating step comprises:

[0010] Coating the surface of Si powder with at least one ceramic layer selected from SiC layer, Si3N4 layer, TiN layer or TiO2 layer; and / or

[0011] A ceramic layer selected from at least one of a TiN layer and a TiO2 layer is coated on the surface of the SiOx powder.

[0012] According to any one of the embodiments of the first aspect of the present application, the coating step comprises:

[0013] The Si powder is contacted with a reaction gas selected from ethylene or nitrogen under heating conditions and reacts to obtain SiC layer / Si3N4 layer coated Si powder particles.

[0014] According to any one of the embodiments of the first aspect of the present application, the coating step further comprises:

[0015] Ethylene is introduced into the Si powder, and a heating reaction is performed; preferably, the heating reaction is performed at a temperature of 850-900°C for 40-120 min;

[0016] The heating is stopped, and the temperature is raised to continue the reaction to obtain SiC layer coated Si powder particles; preferably, the temperature is raised to 1300-1500°C.

[0017] According to any one of the embodiments of the first aspect of the present application, the coating step further comprises:

[0018] Nitrogen is introduced into the Si powder, and a heating reaction is performed, and then a temperature reduction treatment is performed to obtain Si3N4 layer coated Si powder particles; preferably, the heating reaction is performed at a temperature of 1200-1500°C for 40-120 min, and the temperature reduction treatment is performed by reducing the temperature to 80-100°C.

[0019] According to any one of the embodiments of the first aspect of the present application, the coating step comprises:

[0020] The Si powder and / or SiOx powder is mixed with a tetrabutyl orthotitanate solution and reacts, and then the solid product obtained by the reaction is calcined to obtain TiN layer / TiO2 layer coated particles.

[0021] According to any one of the embodiments of the first aspect of the present application, the coating step further comprises:

[0022] The Si powder and / or SiOx powder is mixed with an organic solution of tetrabutyl orthotitanate, and then water is added, and a hydrolysis reaction is performed after the temperature is raised to obtain a solid product; preferably, the organic solution is an ethanol solution, and the temperature is raised to 80-100°C;

[0023] The solid product is calcined to obtain TiO2 layer coated Si powder particles / SiOx powder particles; preferably, the calcination is performed at a temperature of 900-1000°C for 300-400 min.

[0024] According to any one of the embodiments of the first aspect of the present application, the coating step further comprises:

[0025] The solid product is calcined in ammonia to obtain TiN layer-coated Si powder particles / SiOx powder particles; preferably, the calcination temperature is 900-1000° C. and the calcination time is 300-400 min.

[0026] According to any embodiment of the first aspect of the present application, the mixing step comprises mixing the ceramic layer coated particles with the metallic lithium powder in a molar ratio of 1:(0.01-100), preferably 1:(2-80).

[0027] According to any embodiment of the first aspect of the present application, the heat treatment step comprises heat treating the mixture at a temperature of 200-800° C., preferably 300-600° C., for 0.1-100 h, preferably 5-80 h.

[0028] The second aspect of the present application provides a pre-lithiation silicon-based negative electrode material, which is prepared using the method of the first aspect of the present application.

[0029] The third aspect of the present application provides a negative electrode plate, comprising the pre-lithiated silicon-based negative electrode material prepared by the method of the first aspect of the present application or the pre-lithiated silicon-based negative electrode material of the second aspect of the present application.

[0030] Compared with the prior art, this application has at least the following beneficial effects:

[0031] The method for pre-lithiation of silicon-based negative electrode materials provided in the present application fully utilizes the process characteristics of the thermochemical method and changes the traditional pre-lithiation process. By coating the silicon-based material with a ceramic layer and heating it with metallic lithium powder, the pre-lithiation of the silicon-based negative electrode material can be achieved, thereby obtaining an electrode material with good pre-lithiation effect. The method is simple to operate and has good repeatability, thereby overcoming the defects of the existing pre-lithiation technology that is immature and complex to operate, and has important application value in lithium-ion battery negative electrode materials and other aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0033] Figure 1 This is a capacity-voltage curve diagram of the first charging process of a battery assembled from a pre-lithiated silicon-based negative electrode material provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the application purpose, technical solution and beneficial technical effects of this application clearer, the application is further described in detail below with reference to the embodiments. It should be understood that the embodiments described in this specification are only for explaining this application and are not intended to limit this application.

[0035] For simplicity, only some numerical ranges are explicitly disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and similarly, any upper limit can be combined with any other upper limit to form an unspecified range. In addition, although not explicitly stated, each point or individual value between the endpoints of a range is included in the range. Thus, each point or individual value can serve as its own lower limit or upper limit and be combined with any other point or individual value, or with other lower limits or upper limits, to form an unspecified range.

[0036] In the description of this article, it should be noted that, unless otherwise specified, “above” and “below” are inclusive of the number themselves, and “a variety” in “one or more” means more than two.

[0037] The above disclosure of the present application is not intended to describe every disclosed embodiment or every implementation in the present application. The following description more specifically illustrates exemplary embodiments. In many places throughout the application, guidance is provided through a series of examples, which can be used in various combinations. In each example, the enumeration is intended only as a representative group and should not be construed as exhaustive.

[0038] An embodiment of the first aspect of the present application provides a method for pre-lithiation of a silicon-based negative electrode material, comprising:

[0039] S2, coating step, for coating the surface of Si powder or SiOx powder with a ceramic layer to obtain ceramic layer coated particles, wherein 0 <x<2;

[0040] S4, a mixing step for mixing the ceramic layer coated particles with the metallic lithium powder to obtain a mixture;

[0041] S6, a heat treatment step, for heat-treating the mixture to lithiate the Si powder or SiOx powder to obtain a pre-lithiated silicon-based negative electrode material.

[0042] The method for pre-lithiation of silicon-based negative electrode materials provided in the present application fully utilizes the process characteristics of the thermochemical method, changes the traditional pre-lithiation process, and achieves pre-lithiation of the silicon-based negative electrode material by coating the silicon-based material with a ceramic layer and heating it with metallic lithium powder, thereby obtaining an electrode material with good pre-lithiation effect; and the method is simple to operate and has good repeatability, thereby overcoming the defects of the existing pre-lithiation technology that is immature and complex to operate, and has important application value in lithium-ion battery negative electrode materials and other aspects.

[0043] In some embodiments, the coating step S2 includes:

[0044] S20. Coating the surface of the Si powder with a ceramic layer selected from at least one of a SiC layer, a Si3N4 layer, a TiN layer, and a TiO2 layer.

[0045] In some embodiments, the coating step S2 includes:

[0046] S22. Coating the surface of the SiOx powder with a ceramic layer selected from at least one of a TiN layer and a TiO2 layer.

[0047] In the present application, by coating the surface of Si powder and SiOx powder with a ceramic layer, it is beneficial to obtain ceramic layer-coated particles with uniform particle size distribution, which facilitates uniform mixing with metallic lithium powder in subsequent steps, thereby facilitating the subsequent heat treatment to allow more lithium powder to be embedded in the ceramic layer-coated particles and react, thereby obtaining a pre-lithiation silicon-based negative electrode material with excellent pre-lithiation effect.

[0048] In any embodiment, step S20 includes:

[0049] S200, contacting and reacting Si powder with a reaction gas selected from ethylene or nitrogen under heating conditions to obtain SiC layer / Si3N4 layer-coated Si powder particles.

[0050] In any embodiment, step S200 further includes:

[0051] S2000, introducing ethylene into Si powder to carry out heating reaction;

[0052] S2002, stop the ethylene flow, continue the reaction after heating, and obtain SiC layer-coated Si powder particles.

[0053] In any embodiment, the temperature of the heating reaction in step S2000 is preferably 850-900° C., such as 850° C., 870° C., 880° C., 890° C., and 900° C., etc.

[0054] In any embodiment, the heating reaction time in step S2000 is preferably 40 to 120 minutes, for example, 40 minutes, 60 minutes, 80 minutes, 100 minutes, 120 minutes, and the like.

[0055] In any embodiment, the reactions in step S2000 and step S2002 need to be performed in an argon atmosphere that does not participate in the reaction.

[0056] In any embodiment, the temperature increase in step S2002 is preferably to increase the temperature to 1300-1500° C., such as 1300° C., 1400° C., and 1500° C., etc.

[0057] In the present application, by controlling the temperature and time of the heating reaction within a suitable range, ethylene is facilitated to react with silicon on the surface of the silicon powder, thereby forming SiC layer-coated Si powder particles with surface pores and uniform particle size distribution.

[0058] In any embodiment, step S200 further includes:

[0059] S2020. Nitrogen is introduced into the Si powder, and the Si powder is subjected to a heating reaction and then a cooling treatment to obtain Si3N4 layer-coated Si powder particles.

[0060] In any embodiment, the temperature of the heating reaction in step S2020 is preferably 1200-1500° C., such as 1200° C., 1300° C., 1400° C., and 1500° C., etc.

[0061] In any embodiment, the heating reaction time in step S2020 is preferably 40 to 120 minutes, for example, 40 minutes, 60 minutes, 80 minutes, 100 minutes, 120 minutes, and the like.

[0062] In any embodiment, the cooling treatment in step S2020 preferably reduces the temperature to 80-100° C., such as 80° C., 90° C., and 100° C., etc.

[0063] In the present application, by controlling the temperature and time of the heating reaction within a suitable range, nitrogen is facilitated to react with silicon on the surface of the silicon powder, thereby forming Si3N4 layer-coated Si powder particles with surface pores and uniform particle size distribution.

[0064] In some embodiments, step S22 includes:

[0065] S220, mixing Si powder and / or SiOx powder with tetrabutyl orthotitanate solution and reacting them, and then calcining the solid product obtained by the reaction to obtain TiN layer / TiO2 layer coated particles.

[0066] In any embodiment, the tetrabutyl orthotitanate solution in step S220 is preferably an organic solution of tetrabutyl orthotitanate dissolved in an organic solvent. The type of the organic solvent is not limited and can be selected according to actual needs, which is preferably an alcohol organic solvent, such as ethanol, propanol, butanol, and the like; and more preferably ethanol.

[0067] In any embodiment, step S220 further comprises:

[0068] S2201, mixing Si powder with the ethanol solution of tetrabutyl orthotitanate, then adding water, and performing hydrolysis reaction after temperature rising to obtain a solid product;

[0069] S2203, calcining the solid product to obtain Si powder particles coated with TiO2 layer.

[0070] In any embodiment, the temperature rising in step S2201 is preferably rising the temperature to 80-100℃, such as 80℃, 90℃, and 100℃, and the like.

[0071] In any embodiment, the calcination temperature in step S2203 is preferably 900-1000℃, such as 900℃, 920℃, 940℃, 960℃, 980℃, and 1000℃, and the like.

[0072] In any embodiment, the calcination time in step S2203 is preferably 300-400min, such as 300min, 320min, 340min, 360min, 380min, and 400min, and the like.

[0073] In any embodiment, step S220 further comprises:

[0074] S2202, mixing SiOx powder with the ethanol solution of tetrabutyl orthotitanate, then adding water, and performing hydrolysis reaction after temperature rising to obtain a solid product;

[0075] S2204, calcining the solid product to obtain SiOx powder particles coated with TiO2 layer.

[0076] In any embodiment, the temperature rising in step S2202 is preferably rising the temperature to 80-100℃, such as 80℃, 90℃, and 100℃, and the like.

[0077] In any embodiment, the calcination temperature in step S2204 is preferably 900-1000℃, such as 900℃, 920℃, 940℃, 960℃, 980℃, and 1000℃, and the like.

[0078] In any embodiment, the calcination time in step S2204 is preferably 300 to 400 min, such as 300 min, 320 min, 340 min, 360 min, 380 min, and 400 min.

[0079] In any embodiment, after the hydrolysis reaction is performed in step S2201 and step S2202, the method may optionally include filtering, washing and drying the mixed solution obtained after the hydrolysis reaction to obtain a solid product.

[0080] In any embodiment, the drying method is not specifically limited and can be selected according to actual needs, for example, natural drying, oven drying, blow drying, etc. can be selected.

[0081] The present application controls the temperature and time of the hydrolysis reaction within a suitable range, thereby facilitating the hydrolysis reaction and generating a silicon-based solid product with a surface-coated TiO2 layer. Controlling the calcination temperature and time within a suitable range facilitates the reaction of the silicon-based solid product and the formation of TiO2-coated Si powder particles or TiO2-coated SiOx powder particles with surface porosity and uniform particle size distribution, thereby facilitating the subsequent embedding of metallic lithium powder and achieving pre-lithiation.

[0082] In any embodiment, step S220 further includes:

[0083] S2210, mixing Si powder with an ethanol solution of tetrabutyl orthotitanate, adding water, heating and performing a hydrolysis reaction to obtain a solid product;

[0084] S2230, calcining the solid product in ammonia to obtain TiN layer-coated Si powder particles.

[0085] In any embodiment, the temperature increase in step S2210 is preferably to increase the temperature to 80-100°C, for example, 80°C.

[0086] In any embodiment, the calcination temperature in step S2230 is preferably 900-1000° C., such as 900° C., 920° C., 940° C., 960° C., 980° C., and 1000° C., etc.

[0087] In any embodiment, the calcination time in step S2230 is preferably 300 to 400 min, such as 300 min, 320 min, 340 min, 360 min, 380 min, and 400 min.

[0088] In any embodiment, step S220 further includes:

[0089] S2220, mixing SiOx powder with an ethanol solution of tetrabutyl orthotitanate, adding water, heating and performing a hydrolysis reaction to obtain a solid product;

[0090] S2240, calcining the solid product in ammonia to obtain TiN layer-coated SiOx powder particles.

[0091] In any embodiment, the temperature increase in step S2220 is preferably to increase the temperature to 80-100° C., such as 80° C., 90° C., and 100° C., etc.

[0092] In any embodiment, the calcination temperature in step S2240 is preferably 900-1000° C., such as 900° C., 920° C., 940° C., 960° C., 980° C., and 1000° C., etc.

[0093] In any embodiment, the calcination time in step S2240 is preferably 300 to 400 min, such as 300 min, 320 min, 340 min, 360 min, 380 min, and 400 min.

[0094] In any embodiment, after the hydrolysis reaction is performed in step S2210 and step S2220, the following method may be optionally included: filtering, washing and drying the mixed solution obtained after the hydrolysis reaction to obtain a solid product.

[0095] In any embodiment, the drying method is not specifically limited and can be selected according to actual needs, for example, natural drying, oven drying, blow drying, etc. can be selected.

[0096] The present application controls the temperature and time of the hydrolysis reaction within a suitable range, thereby facilitating the hydrolysis reaction and generating a silicon-based solid product with a surface-coated TiN layer. Controlling the calcination temperature and time within a suitable range facilitates the reaction of ammonia with the TiN layer of the silicon-based solid product to form TiN-coated Si powder particles or TiN-coated SiOx powder particles with surface pores and uniform particle size distribution, thereby facilitating the subsequent embedding of metallic lithium powder and achieving pre-lithiation.

[0097] In some embodiments, the mixing step S4 comprises:

[0098] S40, mixing ceramic layer coated particles and metallic lithium powder at a molar ratio of 1:(0.01-100).

[0099] In any embodiment, the molar ratio of the ceramic layer coated particles to the metallic lithium powder in step S40 is preferably 1:(2-80).

[0100] In the present application, by controlling the molar ratio of the ceramic layer coated particles to the metallic lithium powder within a suitable range, it is beneficial for the metallic lithium powder to diffuse into the ceramic layer coated particles and react during the subsequent reaction process, thereby achieving a better pre-lithiation effect.

[0101] In some embodiments, the heat treatment step S6 comprises:

[0102] S60, heat-treating the mixture at a temperature of 200 to 800° C. for 0.1 to 100 hours.

[0103] In any embodiment, the temperature of the heat treatment in step S60 is preferably 300-600° C., such as 300° C., 400° C., and 500° C.

[0104] In any embodiment, the heat treatment time in step S60 is preferably 5 to 80 hours, such as 5 hours, 10 hours, 15 hours, 20 hours, 25 hours, and 30 hours.

[0105] The present application controls the temperature and time of the above-mentioned heat treatment within a suitable range, which is conducive to the full diffusion and embedding of metallic lithium powder into the ceramic layer-coated particles and the reaction, thereby obtaining a pre-lithium-embedded silicon-based negative electrode material and achieving a good pre-lithiation effect.

[0106] An embodiment of the second aspect of the present application provides a pre-lithiated silicon-based negative electrode material, which is prepared using the method of the first aspect of the present application.

[0107] In any embodiment, the pre-lithiated silicon-based negative electrode material provided in the present application can be used as a negative electrode material for lithium-ion secondary batteries.

[0108] An embodiment of the third aspect of the present application provides a negative electrode plate, comprising a pre-lithiated silicon-based negative electrode material prepared by the method provided in the first aspect of the present application or the pre-lithiated silicon-based negative electrode material provided in the second aspect of the present application.

[0109] In any embodiment, the negative electrode plate may further optionally include carbon black, carboxymethyl cellulose and tetrahydrofuran.

[0110] In any embodiment, the preparation of the negative electrode plate may include: preparing an electrode slurry with a pre-lithiated silicon-based negative electrode material, carbon black, carboxymethyl cellulose and tetrahydrofuran, and dripping the slurry onto a copper foil to obtain a pre-lithiated negative electrode plate.

[0111] In any embodiment, the negative electrode sheet of the present application can be used in a lithium-ion secondary battery.

[0112] Example

[0113] The following examples describe the present disclosure in more detail and are intended to be illustrative only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and used directly without further processing, and all instruments used in the examples are commercially available.

[0114] Example 1

[0115] (1) Coating the Si powder surface with a TiN layer, specifically: first, mixing the Si powder with an ethanol solution of tetrabutyl orthotitanate, adding an appropriate amount of water, and hydrolyzing at 80°C; then filtering, washing, and drying the resulting mixture; and finally calcining the solid sample in ammonia (900°C, 300 min) to obtain TiN-coated Si powder particles;

[0116] (2) In an argon atmosphere, the TiN-coated Si powder particles obtained in step (1) were thoroughly mixed with metallic lithium powder in a molar ratio of 1:2;

[0117] (3) The sample mixed in step (2) is heated at 300° C. for 15 min to obtain a black solid. The obtained black solid is mixed with carbon black, carboxymethyl cellulose and tetrahydrofuran to make an electrode slurry, which is then dropped onto a copper foil to make an electrode material.

[0118] Test section

[0119] The electrode material obtained in Example 1 was assembled into a battery and the capacity-voltage curve analysis test of the first charging process was carried out. The test results are shown in the attached figure. Figure 1 shown.

[0120] Through analysis Figure 1 It can be seen that the battery assembled using the electrode material in the above-mentioned Example 1 has a certain charging capacity (the charging capacity of the pure TiN layer-coated Si powder particles is 0), which proves that the method for pre-lithiation of silicon-based negative electrode materials provided in this application can achieve pre-lithiation of silicon-based negative electrode materials, and can obtain pre-lithiation silicon-based negative electrode materials with excellent pre-lithiation effect.

[0121] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for pre-lithiation of silicon-based negative electrode materials, characterized in that: Comprising: A coating step for coating a ceramic layer on the surface of Si powder or SiOx powder to obtain ceramic layer-coated particles, where 0 < x < 2; the coating step includes: coating at least one of a SiC layer, a Si3N4 layer, a TiN layer, or a TiO2 layer on the surface of the Si powder; Coating Si powder particles with a SiC layer or a Si3N4 layer includes: introducing ethylene into the Si powder and carrying out a heating reaction; the temperature of the heating reaction is 850 - 900 °C, and the time is 40 - 120 min; stop introducing ethylene, raise the temperature and continue the reaction to obtain the SiC layer-coated Si powder particles; the temperature increase is to raise the temperature to 1300 - 1500 °C; or introduce nitrogen into the Si powder, carry out a heating reaction and then cooling treatment to obtain the Si3N4 layer-coated Si powder particles; the temperature of the heating reaction is 1200 - 1500 °C, the time is 40 - 120 min, and the cooling treatment is to lower the temperature to 80 - 100 °C Or coating at least one of a TiN layer or a TiO2 layer on the surface of the SiOx powder; A mixing step for mixing the ceramic layer-coated particles with lithium metal powder to obtain a mixture; A heat treatment step for heat-treating the mixture to lithiate the Si powder or SiOx powder to obtain a prelithiated silicon-based anode material.

2. The method according to claim 1, wherein The coating step includes: Mixing and reacting the Si powder or the SiOx powder with tetrabutyl orthotitanate solution, and then calcining the solid product obtained from the reaction to obtain TiN layer- or TiO2 layer-coated particles.

3. The method according to claim 2, wherein The coating step further includes: Mixing the Si powder or the SiOx powder with an organic solution of tetrabutyl orthotitanate, adding water, raising the temperature and carrying out a hydrolysis reaction to obtain a solid product; Calcining the solid product to obtain TiO2 layer-coated Si powder particles or SiOx powder particles.

4. The method according to claim 3, wherein The organic solution is an ethanol solution, and the temperature increase is to raise the temperature to 80 - 100 °C; The temperature of the calcining is 900 - 1000 °C, and the time is 300 - 400 min.

5. The method according to any one of claims 2 to 4, characterized in that The coating step further includes: Calcining the solid product in ammonia gas to obtain TiN layer-coated Si powder particles or SiOx powder particles.

6. The method according to claim 5, wherein The temperature of the calcining is 900 - 1000 °C, and the time is 300 - 400 min.

7. The method according to claim 1, wherein The mixing step includes mixing the ceramic layer-coated particles and the lithium metal powder at a molar ratio of 1:(0.01 - 100).

8. The method according to claim 7, wherein The molar ratio of the ceramic layer-coated particles to the lithium metal powder in the mixture is 1:(2 - 80).

9. The method according to claim 1, wherein The heat treatment step includes heat-treating the mixture at a temperature of 200 - 800 °C for 0.1 - 100 h.

10. The method according to claim 9, wherein The heat treatment step includes heat-treating the mixture at a temperature of 300 - 600 °C for 5 - 80 h.

11. A pre-lithiation silicon-based negative electrode material, characterized in that: Prepared by the method according to any one of claims 1 - 10.

12. A negative electrode plate, characterized in that: Comprising the prelithiated silicon-based anode material prepared by the method according to any one of claims 1 - 10 or the prelithiated silicon-based anode material according to claim 11.

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