Preparation method of carbon-coated hollow silicon-oxygen material, negative electrode and lithium battery

Abstract

The application relates to a preparation method of carbon-coated hollow siloxane material, which comprises the following steps: potassium hexacyanocobaltate, cobalt acetate tetrahydrate and trisodium citrate are added into deionized water, a first solution is obtained after complete dissolution, and the first solution is collected after solid is precipitated from the first solution to obtain a cobalt hexacyanocobaltate nano template; the nano template is added into a second solution, a layer of siloxane compound layer is prepared on the surface of the nano template to obtain an intermediate; the intermediate is dispersed into a third solution, the second solution is subjected to heat treatment at a predetermined temperature, a carbon-coated layer is prepared on the surface of the siloxane compound layer, the generated solid is collected, and the carbon-coated hollow siloxane material is obtained, wherein the second solution comprises tetraethyl orthosilicate, ethanol, ammonia and water, and the third solution comprises an amine compound, ethanol and selenium dioxide. The application solves the technical problem that the carbon-coated hollow siloxane negative electrode is difficult to prepare.

Description

Technical Field

[0001] This application relates to lithium battery anode materials, and more particularly to silicon-based anode materials. Background Technology

[0002] With the increasing demand for lithium-ion battery energy density from industries such as electric vehicles, silicon-based anodes are being used more and more widely in lithium-ion batteries. Especially in solid-state batteries, to achieve higher energy density, the anode often contains a high silicon content. However, the problems with silicon-based anodes have not been completely solved. The main problem with silicon-based anodes is the enormous volume expansion of silicon particles after lithium intercalation, exceeding 300%, leading to a series of consequences such as particle pulverization, electrode structure damage, and repeated growth of the SEI film, resulting in poor long-cycle performance of the battery. Solving the expansion problem of silicon anodes has always been a hot research topic in academia and industry. There are many solutions to the silicon anode expansion problem, one important approach being the hollow design of the silicon anode structure. Carbon-coated hollow silicon-oxygen anodes are currently a promising design scheme. The carbon coating increases the conductivity of the anode material, and the hollow structure provides sufficient space for expansion during the lithium intercalation process. However, the fabrication of carbon-coated hollow silicon-oxygen anodes is extremely difficult. Summary of the Invention

[0003] This application provides a method for preparing carbon-coated hollow silicon-oxygen materials, an anode, and a lithium battery, to solve the technical problem that the preparation of carbon-coated hollow silicon-oxygen anodes is very difficult.

[0004] In a first aspect, embodiments of this application provide a method for preparing a carbon-coated hollow silicon oxide material, the method comprising the following steps:

[0005] Potassium hexacyanocobalaminate, cobalt acetate tetrahydrate, and trisodium citrate were added to deionized water and completely dissolved to obtain the first solution. After the first solution precipitated a solid, the precipitated solid was collected to obtain the cobalt hexacyanocobalaminate nanotemplate.

[0006] The nanotemplate is added to a second solution, and a silicon oxide layer is prepared on the surface of the nanotemplate to obtain an intermediate.

[0007] The intermediate is dispersed in a third solution, and the second solution is heat-treated at a predetermined temperature to prepare a carbon coating layer on the surface of the silicon oxide layer. The solid generated during the reaction is collected to obtain the carbon-coated hollow silicon oxide material.

[0008] The second solution comprises tetraethyl orthosilicate, ethanol, ammonia, and water, and the third solution comprises amine compounds, ethanol, and selenium dioxide.

[0009] In some embodiments of this application, the mass ratio of potassium hexacyanocobalaminate to cobalt acetate tetrahydrate is 0.8 to 1:1; and / or,

[0010] The mass ratio of trisodium citrate to cobalt acetate tetrahydrate is 1.5 to 2:1.

[0011] In some embodiments of this application, potassium hexacyanocobalaminate, cobalt acetate tetrahydrate, and trisodium citrate are added to deionized water, wherein the mass ratio of deionized water to cobalt acetate tetrahydrate is 250-300:1.

[0012] In some embodiments of this application, the molar ratio of the tetraethyl orthosilicate to the cobalt hexacyanocobalaminate is 0.3 to 0.45:1.

[0013] In some embodiments of this application, the molar ratio of selenium dioxide to potassium hexacyanocobalaminate is 2 to 3:1.

[0014] In some embodiments of this application, the volume ratio of the amine compound to the ethanol in the third solution is 0.8 to 1:1.

[0015] In some embodiments of this application, the predetermined temperature is 180°C to 230°C; and / or,

[0016] The heat treatment time is 6 to 12 hours.

[0017] In some embodiments of this application, the amine compound is at least one of hexylamine, heptaamine, octylamine, and nonylamine.

[0018] Secondly, embodiments of this application provide a negative electrode, the material of which includes carbon-coated hollow silicon-oxygen material prepared by the method described in any embodiment of the first aspect.

[0019] Thirdly, embodiments of this application provide a lithium battery, wherein the negative electrode of the lithium battery is the negative electrode described in any embodiment of the second aspect.

[0020] The technical solutions provided in this application have the following advantages compared with the prior art:

[0021] The method for preparing carbon-coated hollow silicon oxide material provided in this application embodiment uses cobalt hexacyanocobalaminate as a nanotemplate, prepares a silicon oxide compound layer on the surface of the nanotemplate, prepares a carbon coating layer on the surface of the silicon oxide compound layer by using amine compounds, and removes the nanotemplate by using selenium dioxide, thereby preparing carbon-coated hollow silicon oxide material, which solves the technical problem of difficult preparation of carbon-coated hollow silicon oxide anode. Attached Figure Description

[0022] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic flowchart illustrating a method for preparing a carbon-coated hollow silicon oxide material according to an embodiment of this application;

[0025] Figure 2 This is a scanning electron microscope image of the carbon-coated hollow silicon oxide material prepared in Example 1 of this application;

[0026] Figure 3 This is a scanning electron microscope image of the carbon-coated hollow silicon oxide material prepared in Example 2 of this application;

[0027] Figure 4 This is a scanning electron microscope image of the cobalt hexacyanocobalamin nanotemplate prepared in Example 1 of this application;

[0028] Figure 5 This is a scanning electron microscope image of cobalt hexacyanocobalanate prepared in the comparative example of this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] Unless otherwise specified, the terminology used herein should be understood as having the meaning as commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In case of any conflict, this specification shall prevail.

[0031] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0032] Existing carbon-coated hollow silicon-oxygen anodes face technical challenges in their fabrication.

[0033] The technical solution provided in this application is to solve the above-mentioned technical problems, and the general idea is as follows:

[0034] In a first aspect, embodiments of this application provide a method for preparing a carbon-coated hollow silicon oxide material, the method comprising the following steps:

[0035] S1: Add potassium hexacyanocobalaminate, cobalt acetate tetrahydrate, and trisodium citrate to deionized water and dissolve them completely to obtain the first solution. After the first solution precipitates a solid, collect the precipitated solid to obtain the cobalt hexacyanocobalaminate nanotemplate.

[0036] S2: The nanotemplate is added to the second solution, and a silicon oxide layer is prepared on the surface of the nanotemplate to obtain an intermediate;

[0037] S3: The intermediate is dispersed in a third solution, and the second solution is heat-treated at a predetermined temperature to prepare a carbon coating layer on the surface of the silicon oxide layer. The solid generated by the reaction is collected to obtain the carbon-coated hollow silicon oxide material.

[0038] The second solution comprises tetraethyl orthosilicate, ethanol, ammonia, and water, and the third solution comprises amine compounds, ethanol, and selenium dioxide.

[0039] In step S1, the role of trisodium citrate is that the citrate ion can complex with cobalt ions, thereby controlling the concentration of cobalt ions and thus controlling the precipitation rate of cobalt hexacyanocobalaminate, making it easier to obtain cobalt hexacyanocobalaminate nanocubes with relatively regular shapes and small particle sizes.

[0040] In step S2, tetraethyl orthosilicate is gradually hydrolyzed in an alkaline environment provided by ammonia, and a layer of silicon oxide is gradually formed on the surface of the nanotemplate.

[0041] In step S3, amines act as carbon sources and reducing agents to reduce silicon oxides and simultaneously perform carbon coating; selenium dioxide reacts with cobalt hexacyanocobalaminate to generate cobalt selenide, which dissolves and removes the template.

[0042] This application uses cobalt hexacyanocobalaminate as a nanotemplate to prepare a silicon oxide layer on the surface of the nanotemplate. A carbon coating layer is then prepared on the surface of the silicon oxide layer using amine compounds, and the nanotemplate is removed using selenium dioxide. This process yields a carbon-coated hollow silicon oxide material, solving the technical problem of the difficulty in preparing carbon-coated hollow silicon oxide anodes.

[0043] In addition, this application uses potassium hexacyanocobalaminate, cobalt acetate tetrahydrate, and trisodium citrate as raw materials to prepare cobalt hexacyanocobalaminate nanotemplates with regular cubic structure and uniform particle size, which in turn makes it easy to prepare carbon-coated hollow silicon oxide materials with relatively regular structure and relatively uniform particle size.

[0044] In some embodiments of this application, step S1 is specifically implemented as follows:

[0045] Potassium hexacyanocobalaminate, cobalt acetate tetrahydrate, and trisodium citrate were added to deionized water and stirred vigorously for 3–5 minutes after complete dissolution. The mixture was then allowed to stand for 20–30 hours. The precipitated solid was collected by centrifugation and washed with water and anhydrous ethanol in sequence. The solid was then vacuum dried to obtain cobalt hexacyanocobalaminate nanotemplates.

[0046] In some embodiments of this application, step S2 is implemented as follows:

[0047] The cobalt hexacyanocobalamin nanotemplate was dispersed in deionized water, and ammonia was added to adjust the pH to above 12. Then, a mixture of tetraethyl orthosilicate and ethanol was added, and the mixture was stirred for 3-5 hours. The precipitated solid was collected, and the solid was washed with water and anhydrous ethanol in sequence. The solid was then vacuum dried to obtain an intermediate.

[0048] In some embodiments of this application, step S3 is implemented as follows:

[0049] The intermediate and selenium dioxide are dispersed together in a mixture of amine compounds and ethanol. The second solution is heat-treated at a predetermined temperature. The solid generated by the reaction is collected, and the solid is washed with water and anhydrous ethanol in sequence. The solid is then vacuum-dried to obtain the carbon-coated hollow silicon oxide material.

[0050] In some embodiments of this application, the mass ratio of potassium hexacyanocobalaminate to cobalt acetate tetrahydrate is 0.8 to 1:1; and / or,

[0051] The mass ratio of trisodium citrate to cobalt acetate tetrahydrate is 1.5 to 2:1.

[0052] If the mass ratio of potassium hexacyanocobalaate to cobalt acetate tetrahydrate is too high or too low, the resulting cobalt hexacyanocobalaate will likely have more lattice defects and lattice water, which is detrimental to its formation of a regular cube. Therefore, the mass ratio of potassium hexacyanocobalaate to cobalt acetate tetrahydrate can be selected within the above-mentioned range.

[0053] As an example, the mass ratio of potassium hexacyanocobalaminate to cobalt acetate tetrahydrate can be, for example, 0.8:1, 0.85:1, 0.9:1, 0.95:1, or 1:1.

[0054] As an example, the mass ratio of the trisodium citrate to the cobalt acetate tetrahydrate can be, for example, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, or 2:1.

[0055] In some embodiments of this application, potassium hexacyanocobalaminate, cobalt acetate tetrahydrate, and trisodium citrate are added to deionized water, wherein the mass ratio of deionized water to cobalt acetate tetrahydrate is 250-300:1.

[0056] If the amount of deionized water used is too low, the concentration of reactants will be too high, and the reaction rate will be too fast, which may affect the structural regularity and particle size uniformity of cobalt hexacyanocobalamate. If the amount of deionized water used is too high, the concentration of reactants will be too low, and the reaction rate will be too slow, affecting production efficiency.

[0057] As an example, the mass ratio of deionized water to cobalt acetate tetrahydrate can be, for example, 250:1, 260:1, 270:1, 280:1, 290:1, or 300:1.

[0058] In some embodiments of this application, the molar ratio of the tetraethyl orthosilicate to the cobalt hexacyanocobalaminate is 0.3 to 0.45:1.

[0059] If too much tetraethyl orthosilicate is used, the silicon oxide layer will be too thick, which is not conducive to the full release of battery capacity; if too little is used, the wall thickness will be too thin, and damage may occur during the reduction process.

[0060] As an example, the molar ratio of the tetraethyl orthosilicate to the cobalt hexacyanocobalaminate can be, for example, 0.3:1, 0.35:1, 0.4:1, or 0.45:1.

[0061] In some embodiments of this application, the molar ratio of selenium dioxide to potassium hexacyanocobalaminate is 2 to 3:1.

[0062] As an example, the molar ratio of selenium dioxide to potassium hexacyanocobalaminate can be, for example, 2:1, 2.2:1, 2.5:1, 2.8:1, or 3:1.

[0063] In some embodiments of this application, the volume ratio of the amine compound to the ethanol in the third solution is 0.8 to 1:1.

[0064] As an example, in the third solution, the volume ratio of the amine compound to the ethanol can be, for example, 0.8:1, 0.85:1, 0.9:1, 0.95:1, or 1:1.

[0065] In some embodiments of this application, the predetermined temperature is 180°C to 230°C; and / or,

[0066] The heat treatment time is 6 to 12 hours.

[0067] As an example, the predetermined temperature may be 180°C, 190°C, 200°C, 210°C, 220°C, or 230°C.

[0068] As an example, the heat treatment time can be 6h, 7h, 8h, 9h, 10h, 11h, or 12h.

[0069] In some embodiments of this application, the amine compound is at least one of hexylamine, heptaamine, octylamine, and nonylamine.

[0070] Secondly, embodiments of this application provide a negative electrode, the material of which includes carbon-coated hollow silicon-oxygen material prepared by the method described in any embodiment of the first aspect.

[0071] The negative electrode is prepared based on the carbon-coated hollow silicon oxide material preparation method described in the first aspect. The specific implementation of the negative electrode can be referred to the embodiments of the first aspect and common knowledge in the art. Since the negative electrode adopts some or all of the technical solutions of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0072] Thirdly, embodiments of this application provide a lithium battery, wherein the negative electrode of the lithium battery is the negative electrode described in any embodiment of the second aspect.

[0073] The lithium battery is based on the negative electrode described in the second aspect. The specific implementation of the lithium battery can be referred to the embodiments of the second aspect and common knowledge in the art. Since the lithium battery adopts some or all of the technical solutions of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0074] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards. If there is no corresponding industry standard, then common international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0075] Example 1

[0076] This embodiment provides a method for preparing carbon-coated hollow silicon oxide material, including the following steps:

[0077] Sa: Potassium hexacyanocobalaminate, cobalt acetate tetrahydrate, and trisodium citrate were added to deionized water. The mass ratio of potassium hexacyanocobalaminate to cobalt acetate tetrahydrate was 0.88:1, the mass ratio of trisodium citrate to cobalt acetate tetrahydrate was 1.76:1, and the mass ratio of deionized water to cobalt acetate tetrahydrate was 266:1. After complete dissolution, a first solution was obtained. The first solution was stirred vigorously for 3 minutes, allowed to stand for 20 hours, and the precipitated solid was collected by centrifugation. The solid was washed successively with water and anhydrous ethanol. The solid was then vacuum dried to obtain cobalt hexacyanocobalaminate nanotemplates.

[0078] Sb: The cobalt hexacyanocobalaminate nanotemplate was dispersed in deionized water, and ammonia was added to adjust the pH to above 12. Then, a mixture of tetraethyl orthosilicate and ethanol was added to obtain a second solution. The molar ratio of tetraethyl orthosilicate to cobalt hexacyanocobalaminate was 0.36:1, and the volume ratio of deionized water to anhydrous ethanol in the second solution was 1:1. The second solution was stirred for 3 hours, and the precipitated solid was collected. The solid was washed with water and anhydrous ethanol in sequence, and the solid was vacuum dried to obtain an intermediate.

[0079] Sc: The intermediate and selenium dioxide are dispersed together in a mixture of amine compounds and ethanol, wherein the molar ratio of selenium dioxide to potassium hexacyanocobalaminate is 3:1. The second solution is heat-treated at 180°C for 6 hours. The solid generated by the reaction is collected, and the solid is washed successively with water and anhydrous ethanol. The solid is then vacuum-dried to obtain the carbon-coated hollow silicon oxide material.

[0080] Example 2

[0081] This embodiment provides a method for preparing carbon-coated hollow silicon oxide material, including the following steps:

[0082] Sa: Potassium hexacyanocobalaminate, cobalt acetate tetrahydrate, and trisodium citrate were added to deionized water. The mass ratio of potassium hexacyanocobalaminate to cobalt acetate tetrahydrate was 0.8:1, the mass ratio of trisodium citrate to cobalt acetate tetrahydrate was 1.5:1, and the mass ratio of deionized water to cobalt acetate tetrahydrate was 250:1. After complete dissolution, the first solution was obtained. The first solution was stirred vigorously for 5 minutes and allowed to stand for 30 hours. The precipitated solid was collected by centrifugation. The solid was washed successively with water and anhydrous ethanol. The solid was then vacuum dried to obtain cobalt hexacyanocobalaminate nanotemplates.

[0083] Sb: The cobalt hexacyanocobalaminate nanotemplate was dispersed in deionized water, and ammonia was added to adjust the pH to above 12. Then, a mixture of tetraethyl orthosilicate and ethanol was added to obtain a second solution. The molar ratio of tetraethyl orthosilicate to cobalt hexacyanocobalaminate was 0.45:1, and the volume ratio of deionized water to anhydrous ethanol in the second solution was 1:1. The second solution was stirred for 5 hours, and the precipitated solid was collected. The solid was washed with water and anhydrous ethanol in sequence, and the solid was vacuum dried to obtain an intermediate.

[0084] Sc: The intermediate and selenium dioxide are dispersed together in a mixture of amine compounds and ethanol, wherein the molar ratio of selenium dioxide to potassium hexacyanocobalaminate is 3:1. The second solution is heat-treated at 230°C for 12 hours. The solid generated by the reaction is collected, and the solid is washed successively with water and anhydrous ethanol. The solid is then vacuum-dried to obtain the carbon-coated hollow silicon oxide material.

[0085] Example 3

[0086] This embodiment provides a method for preparing carbon-coated hollow silicon oxide material, including the following steps:

[0087] Sa: Potassium hexacyanocobalaminate, cobalt acetate tetrahydrate, and trisodium citrate were added to deionized water at a mass ratio of 1:1, 2:1, and 300:1. After complete dissolution, a first solution was obtained. The first solution was stirred vigorously for 4 minutes, allowed to stand for 24 hours, and the precipitated solid was collected by centrifugation. The solid was washed successively with water and anhydrous ethanol, and then vacuum dried to obtain cobalt hexacyanocobalaminate nanotemplates.

[0088] Sb: The cobalt hexacyanocobalaminate nanotemplate was dispersed in deionized water, and ammonia was added to adjust the pH to above 12. Then, a mixture of tetraethyl orthosilicate and ethanol was added to obtain a second solution. The molar ratio of tetraethyl orthosilicate to cobalt hexacyanocobalaminate was 0.3:1, and the volume ratio of deionized water to anhydrous ethanol in the second solution was 1:1. The second solution was stirred for 4 hours, and the precipitated solid was collected. The solid was washed with water and anhydrous ethanol in sequence, and the solid was vacuum dried to obtain an intermediate.

[0089] Sc: The intermediate and selenium dioxide are dispersed together in a mixture of amine compounds and ethanol, wherein the molar ratio of selenium dioxide to potassium hexacyanocobalaminate is 2.5:1. The second solution is heat-treated at 200°C for 8 hours. The solid generated by the reaction is collected, and the solid is washed successively with water and anhydrous ethanol. The solid is then vacuum-dried to obtain the carbon-coated hollow silicon oxide material.

[0090] Comparative Example

[0091] This comparative example provides cobalt hexacyanocobalanate, which is prepared by the following method:

[0092] Potassium hexacyanocobalaminate and cobalt acetate tetrahydrate were added to deionized water at a mass ratio of 1:1 and 300:1. After complete dissolution, a first solution was obtained. The first solution was stirred vigorously for 4 minutes and allowed to stand for 24 hours. The precipitated solid was collected by centrifugation. The solid was washed with water and anhydrous ethanol in sequence. The solid was then vacuum dried to obtain cobalt hexacyanocobalaminate.

[0093] Relevant experimental and effect data:

[0094] The carbon-coated hollow silicon-oxygen materials prepared in Examples 1 and 2 were observed using a scanning electron microscope. The obtained scanning electron microscope images are shown below. Figure 2 , Figure 3 As shown. Observation Figure 2 , Figure 3 It was found that the carbon-coated hollow silicon oxide materials prepared in Examples 1 and 2 both have regular cubic structures and very uniform particle size.

[0095] The cobalt hexacyanocobalamin nanotemplate prepared in step Sa of Example 1 was observed using a scanning electron microscope. The obtained scanning electron microscope images are as follows: Figure 4 As shown. The cobalt hexacyanocobalaate prepared in the comparative example was observed using a scanning electron microscope (SEM), and the obtained SEM images are shown below. Figure 5 As shown. The only difference between step Sa in Example 1 and the comparative example is that trisodium citrate was added to the reaction system in Example 1. Observation Figure 4 , Figure 5 It was found that the cobalt hexacyanocobalaminate nanotemplate prepared in Example 1 had a regular cubic structure, while the cobalt hexacyanocobalaminate prepared in the comparative example did not have a regular crystal structure. This indicates that the addition of trisodium citrate can effectively control the precipitation process and is beneficial for the formation of a regular cubic structure of cobalt hexacyanocobalaminate.

[0096] The carbon-coated hollow silicon-oxygen materials obtained in Examples 1 and 2 were used to prepare lithium battery anodes. The specific steps are as follows:

[0097] A mixture of carbon-coated hollow silicon oxide material, conductive agent, and binder was prepared in a mass ratio of 85:6:9 and then coated onto the surface of a copper foil current collector. After vacuum drying, the mixture was cut into 12mm diameter electrode sheets to serve as the negative electrode of a lithium battery. The binder was LA133, and the conductive agent was acetylene black.

[0098] The negative electrode was selected from the lithium battery negative electrode materials corresponding to Examples 1-2, and the positive electrode was selected from Li sheets. The button cells were assembled, and the specific capacity, coulombic efficiency and cycle life of the button cells were tested. The results are shown in Table 1.

[0099] Implementation Example 1 1875mAh / g 1710mAh / g 91.2％ 93.0％ Implementation Example 2 2156mAh / g 1988mAh / g 92.2％ 90.6％

[0100] Table 1

[0101] As shown in Table 1, the button cells using carbon-coated hollow silicon-oxygen materials obtained in Examples 1 and 2 as anode materials achieved a remaining capacity of 93.0% and 90.6% after 100 cycles, respectively, which significantly improved their lifespan compared to existing silicon-based anodes.

[0102] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0103] In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. Furthermore, in the description of this application, the terms "comprising," "including," etc., mean "including but not limited to." Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this document, "and / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone. For associations involving three or more related objects described using "and / or", it indicates that any one of the three related objects can exist alone, or at least two of them can exist simultaneously. For example, for A, and / or B, and / or C, it can mean that any one of A, B, and C exists alone, or any two of them exist simultaneously, or all three of them exist simultaneously. In this document, "at least one" means one or more, and "more than one" means two or more. "At least one", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can each be single or multiple.

[0104] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing a carbon-coated hollow silicon oxide material, characterized in that, The preparation method of the carbon-coated hollow silicon oxide material includes the following steps: Potassium hexacyanocobalaminate, cobalt acetate tetrahydrate, and trisodium citrate were added to deionized water and completely dissolved to obtain a first solution. After the first solution precipitated a solid, the precipitated solid was collected to obtain a cobalt hexacyanocobalaminate nanotemplate. The mass ratio of trisodium citrate to cobalt acetate tetrahydrate was 1.5~2:

1. The nanotemplate is added to a second solution, and a silicon oxide layer is prepared on the surface of the nanotemplate to obtain an intermediate. The intermediate is dispersed in a third solution, and the third solution is heat-treated at a predetermined temperature to prepare a carbon coating layer on the surface of the silicon oxide layer. The solid generated during the reaction is collected to obtain the carbon-coated hollow silicon oxide material. The predetermined temperature is 180℃~230℃. The second solution comprises tetraethyl orthosilicate, ethanol, ammonia, and water, and the third solution comprises an amine compound, ethanol, and selenium dioxide, wherein the amine compound is at least one selected from hexylamine, heptylamine, octylamine, and nonylamine.

2. The method for preparing carbon-coated hollow silicon oxide material according to claim 1, characterized in that, The mass ratio of potassium hexacyanocobalaminate to cobalt acetate tetrahydrate is 0.8~1:

1.

3. The method for preparing carbon-coated hollow silicon oxide material according to claim 1, characterized in that, The potassium hexacyanocobalaminate, cobalt acetate tetrahydrate, and trisodium citrate are added to deionized water, wherein the mass ratio of deionized water to cobalt acetate tetrahydrate is 250-300:

1.

4. The method for preparing carbon-coated hollow silicon oxide material according to claim 1, characterized in that, The molar ratio of the tetraethyl orthosilicate to the cobalt hexacyanocobalaminate is 0.3~0.45:

1.

5. The method for preparing carbon-coated hollow silicon oxide material according to claim 1, characterized in that, The molar ratio of selenium dioxide to potassium hexacyanocobalaminate is 2~3:

1.

6. The method for preparing carbon-coated hollow silicon oxide material according to claim 1, characterized in that, In the third solution, the volume ratio of the amine compound to the ethanol is 0.8 to 1:

1.

7. The method for preparing carbon-coated hollow silicon oxide material according to claim 1, characterized in that, The heat treatment time is 6~12 hours.

8. A negative electrode, characterized in that, The negative electrode material includes the carbon-coated hollow silicon-oxygen material prepared by the method described in any one of claims 1 to 7.

9. A lithium battery, characterized in that, The negative electrode of the lithium battery is the negative electrode as described in claim 8.

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