CN111342051A - Silica modified negative electrode composite material, preparation method and battery - Google Patents
Silica modified negative electrode composite material, preparation method and battery Download PDFInfo
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- H01M4/02—Electrodes composed of, or comprising, active material
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- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
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- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
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- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
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Abstract
The invention provides a preparation method of a silicon-oxygen modified cathode composite material, which is characterized in that a high-energy ball milling method is utilized to enable silicon monoxide and magnesium powder to react in situ, and then the silicon monoxide and the magnesium powder are uniformly mixed with graphite by ball milling to prepare a multi-component Si-MgO-G silicon cathode composite material; meanwhile, a solid-liquid phase combination method is adopted to prepare a jelly-like suspension material, and the particles of the mixed solution of the silicon cathode composite material prepared by the preparation method are uniformly dispersed; after high-temperature calcination, the carbon-coated core-shell structure (Si-MgO-G) @ C silicon negative electrode composite material is prepared, and the carbon layer is coated more uniformly. The preparation method is environment-friendly and economical, is suitable for industrial popularization, and the prepared carbon-coated core-shell structure (Si-MgO-G) @ C silicon negative electrode composite material is assembled into a half cell for capacity cycle test, so that the long cycle performance is stable.
Description
Technical Field
The invention relates to the field of energy storage battery materials, in particular to a silica modified cathode composite material, a preparation method and a battery.
Background
Due to the shortage and low utilization rate of the traditional fossil fuel, part of use scenes are replaced by lithium ion batteries with light weight and high energy density, the energy density of the lithium ion batteries is improved at a rate of 7-10% per year with the rapid development of the demand of the times, the hard index of the energy density of the power batteries is released in China, according to the technical route map of energy-saving and new energy vehicles, the demand of 300Wh/kg of the high-energy density lithium ion secondary batteries in 2020 is met, and the energy density target of the pure electric vehicle power batteries in 2025 years is 350 Wh/kg. In order to meet the requirements of new-generation energy, the development of a novel lithium battery cathode technology is imminent. Therefore, the development of new anode materials with high capacity and high safety has become a hot spot and direction of research on anode materials for lithium ion batteries.
In the prior art, most of lithium ion battery negative electrode materials take silicon as a matrix, but the conductivity of the silicon is low and is only 6.7 × 10-4S·cm-1Therefore, it is generally necessary to use a silicon-based composite material as the negative electrode.
However, the silicon-based negative electrode has severe volume expansion (about 400%) in the lithium intercalation and deintercalation process, the stress generated by repeated intercalation and deintercalation of lithium ions easily causes mechanical pulverization of silicon particles, the particles lose electrical contact and even fall off from a current collector, and the silicon-based material and the electrode structure are damaged, so that a fresh silicon surface is exposed to an electrolyte, and a Solid Electrolyte Interface (SEI) film is regenerated. With the progress of charging and discharging, the continuous growth of the SEI film consumes the limited lithium source in the battery anode material and decomposes the electrolyte, so that the internal resistance is continuously increased, and finally, the capacity of the battery is rapidly attenuated due to the collapse of the conductive network caused by the pulverization of the silicon material.
In the prior art, a series of researches are carried out aiming at the problems, but most of the researches are concentrated on colleges and universities or scientific research institutes, so that a plurality of schemes do not meet the environmental protection requirements and are not beneficial to realizing industrialization. Typically, as in chinese patent application 201610503372.5, a core-shell silicon-carbon composite material and a method for preparing the same are disclosed, wherein silica particles are subjected to a magnesiothermic reduction reaction by magnesium powder, the reduction product is in-situ coated by an organic polymer carbon source, and then carbonized, and the carbonized product is corroded by hydrofluoric acid, thereby obtaining the silicon-carbon composite material. The process not only consumes a large amount of heat energy, but also uses hydrofluoric acid with high corrosivity and high pollution to corrode magnesium oxide and silicon oxide, which obviously does not meet the purposes of green, energy conservation and emission reduction, and thus cannot be well popularized in the industry. The silicon cathode material is prepared by a high-energy ball milling method and an asphalt carbon coating method, wherein magnesium oxide (MgO) and a carbon layer both have a positive effect on reduction of the volume expansion rate of silicon, and industrialization is easy to realize.
Disclosure of Invention
The invention aims to provide a silicon-oxygen modified cathode composite material which is used for solving the problems that the volume expansion of a silicon-based cathode in the prior art is easy to cause the rapid attenuation of battery capacity and the low conductivity.
In order to achieve the above purpose, the invention provides the following technical scheme:
a preparation method of a silicon-oxygen modified cathode composite material comprises the steps of obtaining a Si-MgO-G silicon cathode composite material in a high-energy ball milling mode; stirring and mixing the Si-MgO-G silicon negative electrode composite material and carbon powder by using a glue-containing solution, and then drying and calcining to obtain the (Si-MgO-G) @ C silicon negative electrode composite material.
Further, in the invention, the preparation process of the Si-MgO-G silicon negative electrode composite material is as follows:
carrying out ball milling on the micron-sized SiO, wherein the ball milling speed is 300-700 rpm, and the ball milling time is 1-5 h;
mixing and ball-milling the SiO and magnesium powder after ball milling according to the molar mass ratio of (0.9-1.1) to 1, wherein the ball-material ratio is (20-40): 1, ball milling speed is 300-700 rpm, and ball milling time is 2-15 h;
adding graphite for mixing and ball milling, wherein the graphite accounts for 15-30% of the whole powder consisting of SiO, magnesium powder and graphite in parts by weight, and the process adopts argon protection, and the ball-to-material ratio is (20-40): 1, the ball milling speed is 300 rpm-700 rpm, and the ball milling time is 1 h-5 h.
Further, in the present invention, the (Si-MgO-G) @ C silicon negative electrode composite material is prepared as follows:
adding 15-30% by mass of carbon source powder into the gel-containing solution and uniformly stirring;
adding the Si-MgO-G silicon negative electrode composite material into the solution and uniformly stirring;
drying the solution to obtain powder;
calcining the powder at 600-800 ℃ for 2-4 h under the protection of argon at a heating speed of 1-6 ℃/min;
and cooling the calcined material to room temperature at a cooling speed of 1-6 ℃/min.
The invention also discloses a silica modified cathode composite material, which is prepared by the preparation method of the silica modified cathode composite material.
The invention also discloses a battery, and the negative electrode of the battery adopts the silicon-oxygen modified negative electrode composite material.
Has the advantages that:
according to the technical scheme, the invention provides the preparation method of the silicon-oxygen modified cathode composite material, and a simple green environment-friendly high-energy ball milling method combining force, heat and reaction is comprehensively applied, so that the silicon monoxide and the magnesium powder are subjected to in-situ reaction and then are uniformly mixed with graphite by ball milling, and the multi-component Si-MgO-G silicon cathode composite material is prepared; the jelly-like suspended material is further prepared by a solid-liquid phase combination method, the suspended particles are dispersed more uniformly, and no layering is generated;
the raw material resources involved in the process are rich, and the preparation process is low in cost, safe, environment-friendly, simple and easy to operate and can be industrialized;
the composite material prepared by the preparation method has uniform granularity, complete carbon coating structure and more uniform coated carbon layer. The conductivity of the silicon cathode material is increased by adding the conductive graphite for mixed grinding, and buffer phase magnesium oxide (MgO) is generated, so that the volume expansion rate of silicon can be effectively reduced, and the cycle stability of the silicon cathode material is increased;
by assembling the prepared carbon-coated core-shell structure (Si-MgO-G) @ C silicon negative electrode composite material into a half-cell for capacity test, under the current density of 200mA/G, the capacity of the half-cell of the (Si-MgO-G) @ C silicon negative electrode composite material is kept at 1038mAh/G when the half-cell circulates for 440 circles, the capacity is 84.9 percent of the capacity of the initial second circle, and the circulation performance is relatively stable; the charge-discharge efficiency after the second circle is higher and is always kept about 100 percent, and the stable cycle life is long.
It should be understood that all combinations of the foregoing concepts and additional concepts described in greater detail below can be considered as part of the inventive subject matter of this disclosure unless such concepts are mutually inconsistent.
The foregoing and other aspects, embodiments and features of the present teachings can be more fully understood from the following description taken in conjunction with the accompanying drawings. Additional aspects of the present invention, such as features and/or advantages of exemplary embodiments, will be apparent from the description which follows, or may be learned by practice of specific embodiments in accordance with the teachings of the present invention.
Drawings
The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Embodiments of various aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is an SEM photograph of (Si-MgO-G) @ C silicon negative electrode composite obtained in the first example of the present invention;
FIG. 2 is a carbon-coated SEM photograph of a (Si-MgO-G) @ C silicon negative electrode composite material obtained in the first embodiment of the present invention;
fig. 3 is a schematic diagram of the results of the half-cell cycle performance test of the present invention.
Detailed Description
In order to better understand the technical content of the present invention, specific embodiments are described below with reference to the accompanying drawings.
In this disclosure, aspects of the present invention are described with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be appreciated that the various concepts and embodiments described above, as well as those described in greater detail below, may be implemented in any of numerous ways, as the disclosed concepts and embodiments are not limited to any one implementation. In addition, some aspects of the present disclosure may be used alone, or in any suitable combination with other aspects of the present disclosure.
The invention is generated based on the improvement requirement of the lithium battery cathode in the aspect of cycle performance, which is suitable for industrialization, and the two requirements of the lithium battery cathode in cycle performance improvement and industrialization popularization need to be comprehensively considered.
Based on this, the invention proposes the following solutions:
a preparation method of a silicon-oxygen modified cathode composite material,
obtaining Si-MgO-G silicon cathode composite material by high-energy ball milling;
stirring and mixing the Si-MgO-G silicon negative electrode composite material and carbon source powder by using a glue-containing solution, and drying and calcining to obtain the (Si-MgO-G) @ C silicon negative electrode composite material.
In the two steps, the energy consumption is low in a high-energy ball milling mode, and SiO and Mg can be subjected to in-situ reaction to generate an active phase Si and a buffer phase MgO; the stirring mode of the colloid-containing solution is environment-friendly, and the silicon cathode material and the carbon source powder can be uniformly mixed to form uniform and stable suspension.
Specifically, in the invention, the preparation process of the Si-MgO-G silicon negative electrode composite material is as follows:
carrying out ball milling on the micron-sized SiO, wherein the ball milling speed is 300-700 rpm, and the ball milling time is 1-5 h;
mixing and ball-milling the SiO and magnesium powder after ball milling according to the molar mass ratio of (0.9-1.1) to 1, wherein the ball-material ratio is (20-40): 1, ball milling speed is 300-700 rpm, and ball milling time is 2-15 h;
adding graphite for mixed ball milling, wherein the graphite accounts for 15-30% of the whole powder consisting of SiO, magnesium powder and graphite in parts by weight, and in the process, argon is adopted for protection, and new balls are supplemented to ensure that the total ball-to-material ratio is (20-40): 1, the ball milling speed is 300 rpm-700 rpm, and the ball milling time is 1 h-5 h.
Through the process steps, the refined SiO and Mg are subjected to in-situ reaction to generate an active phase Si and a buffer phase MgO, so that the capacitance is improved, and the volume expansion of the silicon cathode material is limited; meanwhile, the addition of the graphite enhances the conductive connectivity among the particles and enhances the conductivity; in order to further improve the cycle stability, conductivity and other electrochemical properties of the silicon cathode material, the multicomponent Si-MgO-G silicon cathode composite material needs to be further subjected to carbon coating modification treatment.
Specifically, in the invention, the preparation process of the (Si-MgO-G) @ C silicon negative electrode composite material is as follows:
adding 15-30% by mass of carbon source powder into the gel-containing solution and uniformly stirring;
adding the Si-MgO-G silicon negative electrode composite material into the solution and uniformly stirring;
drying the solution to obtain powder;
calcining the powder at 600-800 ℃ for 2-4 h under the protection of argon at a heating speed of 1-6 ℃/min;
and cooling the calcined material to room temperature at a cooling speed of 1-6 ℃/min.
According to the scheme, by designing a strategy of preparing a gel-containing solution by mixing solid and liquid, uniform and stable carbon source powder and a silicon cathode composite material jelly-like gel solution are prepared, and the phenomenon of solid-liquid layering is prevented; and then, drying and calcining the low-cost dry colloidal mixture containing the organic carbon source at high temperature to prepare the (Si-MgO-G) @ C silicon cathode composite material with the uniform core-shell carbon coating structure, so that the volume expansion of the silicon cathode material is further limited, the conductivity of the material is increased, and the electrochemical performance of the silicon cathode composite material is better improved.
More specifically, in the above process, the mass fraction of the gel in the gel-containing solution is 2%.
In more detail, in the above process, the glue in the glue-containing solution is an organic adhesive. The organic adhesive is mainly used for forming an adhesive solution, and is a carrier for uniformly mixing an organic carbon source and a silicon negative electrode material in the solution. The organic adhesive includes, but is not limited to, one or a mixture of polyethylene oxide, polypropylene oxide, polyvinyl alcohol, sodium carboxymethyl cellulose, polytetrafluoroethylene, and fluorinated polymer, and derivatives thereof.
In more detail, in the above process, an organic solvent is selected to be mixed with an organic adhesive, and the solvent of the glue-containing solution may optionally include, but is not limited to, one or a mixture of N-methylpyrrolidone, acetone, ethanol, propanol, deionized water, and isopropanol.
In more detail, in the above process, the carbon source powder is derived from an organic carbon source. The organic carbon source is one or a mixture of coal tar pitch, sucrose and glucose. These materials are widely available, readily available, and environmentally friendly.
In order to better develop the invention, 4 examples are provided below.
The first embodiment,
Firstly, a certain amount of micron-sized SiO is taken to be ball-milled for 1h at a high ball-milling speed of 500 rpm.
Respectively weighing SiO powder and magnesium powder (Mg) after ball milling according to the molar mass ratio of 0.95:1, putting the SiO powder and the magnesium powder (Mg) into a stainless steel ball milling tank filled with argon gas together, wherein the ball-material ratio is 20:1, and carrying out ball milling for 5 hours at a high-energy ball milling speed of 500 rpm.
And continuously weighing graphite (G) in a ball milling tank according to the mass fraction of 15 percent, adding the graphite (G) into a stainless steel ball milling tank filled with argon, wherein the ball-to-material ratio is 20:1, and carrying out ball milling for 1h at a high-energy ball milling speed of 500rpm to obtain the Si-MgO-G silicon cathode composite material with the multi-component structure.
Taking a prepared 2% PVA solution; adding asphalt powder with the mass fraction of 20% into the solution, and uniformly stirring by using a magnetic stirrer; adding the Si-MgO-G silicon negative electrode composite material with a multi-element structure into the mixed solution, stirring for 10h by using a magnetic stirrer, then putting the mixed solution into a blast drying box for drying treatment, taking down the powder after completely volatilizing the liquid, putting the powder into a crucible, calcining the powder at 700 ℃ for 3h by using a high-temperature atmosphere tubular resistance furnace at the heating rate of 5 ℃/min and the protective atmosphere of argon during calcination, and cooling to room temperature at the cooling rate of 5 ℃/min to obtain the carbon-coated core-shell structure (Si-MgO-G) @ C silicon negative electrode composite material.
As shown in fig. 1 and 2, SEM photographs of the material obtained in this example and SEM photographs of carbon coating were taken.
Example II,
Firstly, a certain amount of micron-sized SiO is taken to be ball-milled for 3 hours at a high ball-milling speed of 400 rpm.
And respectively weighing the SiO powder and the magnesium powder (Mg) after ball milling according to the molar mass ratio of 1:1, putting the weighed SiO powder and the Mg powder (Mg) into a stainless steel ball milling tank filled with argon, wherein the ball-material ratio is 40:1, and ball milling is carried out for 15 hours at a high-energy ball milling speed of 400 rpm.
Continuously weighing graphite (G) in a ball milling tank according to the mass fraction of 25 percent, adding the graphite (G) into a stainless steel ball milling tank filled with argon, wherein the ball-to-material ratio is 40:1, and carrying out ball milling for 5 hours at a high ball milling speed of 400rpm to obtain the Si-MgO-G silicon cathode composite material with a multi-component structure.
The rest of the procedure was the same as in example one.
Example III,
Firstly, a certain amount of micron-sized SiO is taken to be ball-milled for 1h at a high ball milling speed of 700 rpm.
Respectively weighing SiO powder and magnesium powder (Mg) which are subjected to ball milling according to the molar mass ratio of 1.1:1, putting the weighed SiO powder and magnesium powder (Mg) into a stainless steel ball milling tank filled with argon gas together, wherein the ball-material ratio is 20:1, and carrying out ball milling for 2 hours at a high-energy ball milling speed of 700 rpm.
Continuously weighing graphite (G) in a ball milling tank according to the mass fraction of 20 percent, adding the graphite (G) into a stainless steel ball milling tank filled with argon, wherein the ball-to-material ratio is 20:1, and carrying out ball milling for 1h at a high-energy ball milling speed of 700rpm to obtain the Si-MgO-G silicon cathode composite material with the multi-component structure.
The rest of the procedure was the same as in example one.
Example four,
Firstly, a certain amount of micron-sized SiO is taken to be ball-milled for 5 hours at a high ball-milling speed of 300 rpm.
Respectively weighing SiO powder and magnesium powder (Mg) after ball milling according to the molar mass ratio of 0.9:1, putting the SiO powder and the magnesium powder (Mg) into a stainless steel ball milling tank filled with argon gas together, wherein the ball-material ratio is 40:1, and carrying out ball milling for 15 hours at a high-energy ball milling speed of 300 rpm.
And continuously weighing graphite (G) in a ball milling tank according to the mass fraction of 30 percent, adding the graphite (G) into a stainless steel ball milling tank filled with argon, wherein the ball-to-material ratio is 40:1, and carrying out ball milling for 5 hours at a high-energy ball milling speed of 700rpm to obtain the Si-MgO-G silicon cathode composite material with the multi-component structure.
The rest of the procedure was the same as in example one.
In order to compare the four embodiments more intuitively, the key parameters in the above embodiments are listed in table 1, wherein the ball milling time is numbered and recorded as the first ball milling time, the second ball milling time and the third ball milling time in sequence because the whole process in each embodiment has 3 ball milling times and the ball milling times are inconsistent.
TABLE 1
According to the research on the products produced in the above 4 examples, it was found that in order to ensure the quality of the products, various factors need to be considered in the selection of the ball milling speed and the ball milling time: firstly, the ball milling energy must be enough to ensure the reaction degree of SiO and Mg, and the ball milling energy is positively correlated with the ball milling speed and the ball milling time; if the ball milling speed is low, longer ball milling time is needed to ensure enough ball milling energy; if the ball milling speed is high, the energy is large, the reaction can be sufficient, but if the time is long, the particle agglomeration is easy to cause.
In the embodiments, the electrochemical performance of the product can be effectively improved, wherein the product quality of the first embodiment is the best, the reaction of SiO and Mg is sufficient, the generation rate of the active phase Si and the buffer phase MgO is high, and the electrochemical performance of the product is effectively improved.
A button cell prepared from the carbon-coated core-shell structure (Si-MgO-G) @ C silicon negative electrode composite material obtained in the first embodiment is subjected to constant-current charge-discharge cycle electrochemical performance test.
The procedure for making the button cell was as follows:
mixing a carbon-coated core-shell structure (Si-MgO-G) @ C silicon negative electrode composite material, conductive carbon black Super-P and a binder Polyimide (PI) according to a mass ratio of 8:1:1, adding a proper amount of N-methylpyrrolidone (NMP) solvent, uniformly mixing in an agate mortar to prepare slurry, and uniformly coating the slurry on a copper foil by using a scraper.
And after vacuum drying at 300 ℃ for 3h, punching the sample into a circular electrode plate with the diameter of 13mm by using a die, and assembling the circular electrode plate into a 2025 type button cell in a glove box by using the sample electrode as a research electrode and a metal lithium sheet as a counter electrode.
The test environment was as follows:
the electrochemical cycle of a Xinwei battery testing system is adopted for testing, the charge-discharge current density is 100mA/g, the charge-discharge cut-off voltage is 0.01-1.5V, and the testing temperature is 25 ℃ at room temperature.
The test results were as follows:
under the current density of 200mA/G, (Si-MgO-G) @ C silicon negative electrode composite material half-cell capacity is kept at 1038mAh/G when circulating 440 circles, is 84.9% of the initial second circle capacity, and the circulation performance is relatively stable; the charge-discharge efficiency after the second cycle is high, and is always kept at about 100%, and the stable cycle life is long, as shown in fig. 3.
Therefore, the battery prepared by the composite material prepared by the embodiment of the invention has a good cycle life, and the preparation process is environment-friendly, simple to operate and suitable for industrial popularization.
Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.
Claims (11)
1. A preparation method of a silicon-oxygen modified negative electrode composite material is characterized by comprising the following steps:
obtaining Si-MgO-G silicon cathode composite material by high-energy ball milling;
stirring and mixing the Si-MgO-G silicon negative electrode composite material and carbon source powder by using a glue-containing solution, and drying and calcining to obtain the (Si-MgO-G) @ C silicon negative electrode composite material.
2. The method for preparing the silicon-oxygen-modified anode composite material according to claim 1, wherein the method comprises the following steps:
the preparation process of the Si-MgO-G silicon negative electrode composite material is as follows:
carrying out ball milling on the micron-sized SiO, wherein the ball milling speed is 300-700 rpm, and the ball milling time is 1-5 h;
mixing and ball-milling the SiO and magnesium powder after ball milling according to the molar mass ratio of (0.9-1.1) to 1, wherein the ball-material ratio is (20-40): 1, ball milling speed is 300-700 rpm, and ball milling time is 2-15 h;
adding graphite for mixing and ball milling, wherein the graphite accounts for 15-30% of the whole powder consisting of SiO, magnesium powder and graphite in parts by weight, and the process adopts argon protection, and the ball-to-material ratio is (20-40): 1, the ball milling speed is 300 rpm-700 rpm, and the ball milling time is 1 h-5 h.
3. The method for preparing the silicon-oxygen-modified negative electrode composite material according to claim 2, wherein the method comprises the following steps:
the preparation process of the (Si-MgO-G) @ C silicon negative electrode composite material is as follows:
adding 15-30% by mass of carbon source powder into the gel-containing solution and uniformly stirring;
adding the Si-MgO-G silicon negative electrode composite material into the solution and uniformly stirring;
drying the solution to obtain powder;
calcining the powder at 600-800 ℃ for 2-4 h under the protection of argon at a heating speed of 1-6 ℃/min;
and cooling the calcined material to room temperature at a cooling speed of 1-6 ℃/min.
4. The method for preparing the silicon-oxygen-modified anode composite material according to claim 3, wherein the method comprises the following steps: the mass fraction of the gel content in the gel-containing solution is 2%.
5. The method for preparing the silicon-oxygen-modified anode composite material according to claim 4, wherein the method comprises the following steps: the glue in the glue-containing solution is an organic adhesive.
6. The method for preparing the silicon-oxygen-modified anode composite material according to claim 5, wherein the method comprises the following steps: the organic adhesive is one or a mixture of polyethylene oxide, polypropylene oxide, polyvinyl alcohol, sodium carboxymethyl cellulose, polytetrafluoroethylene and fluorinated polymer and derivatives thereof.
7. The method for preparing the silicon-oxygen-modified anode composite material according to claim 4, wherein the method comprises the following steps: the solvent of the glue-containing solution is one or a mixture of N-methyl pyrrolidone, acetone, ethanol, propanol, deionized water and isopropanol.
8. The method for preparing the silicon-oxygen-modified anode composite material according to claim 3, wherein the method comprises the following steps: the carbon source powder is derived from an organic carbon source.
9. The method for preparing the silicon-oxygen-modified anode composite material according to claim 8, wherein the method comprises the following steps: the organic carbon source is one or a mixture of coal tar pitch, sucrose and glucose.
10. Silicon-oxygen-modified anode composite material prepared by the preparation method of the silicon-oxygen-modified anode composite material as claimed in claims 1 to 9.
11. A battery, characterized by: the silicon-oxygen modified negative electrode composite material of claim 10 is adopted for the negative electrode.
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