Preparation method of high-performance silicon-carbon negative electrode material based on interface design

Abstract

The invention discloses a preparation method of a high-performance silicon-carbon negative electrode material based on interface design, which comprises the following steps: preparing the silicon-carbon negative electrode material: weighing 2.0 g of nano silicon particles, adding absolute ethyl alcohol for ultrasonic treatment, dropwise adding APTES, and heating at 80 DEG C for reflux reaction for 6 hours to obtain aminated silicon nano particles; mixing with glucose, grinding and carbonizing to obtain a carbon-coated precursor; weighing thermoplastic phenolic resin and the like, stirring into viscous liquid, curing, carbonizing, activating and pore-forming to obtain a porous carbon matrix; and mixing with boric acid and the like for heat treatment to enhance toughness. And carrying out gradient pulse silicon deposition to obtain a silicon-carbon precursor, mixing the silicon-carbon precursor with the modified molecular sieve, and introducing silane gas in a plasma atmosphere in a gradient pulse manner to deposit silicon. Dispersing the silicon-carbon precursor, adding a triblock copolymer, stirring, performing heat treatment to form a buffer layer, and performing CVD (chemical vapor deposition) and carbonization treatment to complete triple interface reconstruction, thereby obtaining the high-performance silicon-carbon negative electrode composite material.

Description

Technical Field

[0001] This invention relates to the technical field of lithium-ion battery anode materials, and in particular to a method for preparing high-performance silicon-carbon anode materials based on interface design. Background Technology

[0002] Lithium-ion batteries are among the most important energy storage devices in modern times. Due to their advantages such as high energy density, low operating voltage, environmental friendliness, and long cycle life, they have been widely used in various new energy devices. Silicon-carbon anode materials possess ultra-high theoretical capacity and a low charge / discharge voltage window, making them a promising candidate for applications in the lithium-ion battery field.

[0003] Existing traditional graphite anode materials have low theoretical specific capacity, making it difficult to meet the requirements of high energy density batteries; silicon materials have high theoretical specific capacity, but have two major drawbacks: volume expansion: the volume changes by up to 300% during charging and discharging, leading to particle pulverization; poor conductivity: the intrinsic conductivity is low, affecting the lithium-ion transport efficiency. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, this invention proposes a method for preparing high-performance silicon-carbon anode materials based on interface design. By controlling the interface throughout the entire chain from silicon core pretreatment to final encapsulation, the core technical challenges of silicon-carbon anode materials, such as rapid capacity decay, short cycle life, and poor rate performance, are solved in a coordinated manner. The prepared material has excellent comprehensive electrochemical performance, providing key material support for the development of a new generation of high-energy-density lithium-ion batteries.

[0006] To achieve the above objectives, this invention proposes a method for preparing high-performance silicon-carbon anode materials based on interface design, comprising the following steps.

[0007] S1: Disperse nano-silicon particles in organic solvents such as ethanol or toluene, and sonicate them to remove surface impurities and promote dispersion; then add a silane coupling agent, and heat and reflux the reaction under nitrogen protection to form Si-O-Si bonds between the coupling agent and the surface of the silicon particles, while introducing amino functional groups; finally, convert the amino groups into hydroxyl groups through acylation or hydrolysis to form Si-OH functional groups; thus, the silicon core pretreatment is achieved.

[0008] S2: A porous carbon matrix is ​​prepared by using thermoplastic phenolic resin as the first precursor and polyacrylonitrile as the second precursor. The two precursors are mixed in a certain mass ratio and a curing agent, hexamethyloltrimethylenetetramine, is added. After being dispersed evenly in a solvent, the matrix is ​​heated and cured. It is then carbonized under an inert gas and subsequently activated to form pores under carbon dioxide gas to obtain a porous carbon matrix with a bimodal pore size distribution.

[0009] S3: The obtained porous carbon precursor is mixed with boron-containing compounds and cerium phosphate in a certain mass ratio, and then heat-treated under argon gas to obtain porous carbon with high mechanical strength.

[0010] S4: Silicon material is uniformly distributed in the pores of a porous carbon matrix using plasma-assisted pulsed gradient chemical vapor deposition.

[0011] S5: A triblock copolymer coated on the surface of a silicon-carbon precursor.

[0012] S6: Finally, chemical vapor deposition is used with methane as the carbon source to form a nitrogen-doped carbon coating layer on the material surface at high temperature. Then, low-temperature carbonization is carried out under inert gas to rebuild the interface between silicon and triblock copolymer and form strong chemical bonds.

[0013] In addition, the method for preparing high-performance silicon-carbon anode materials based on interface design proposed above in this application may also have the following additional technical features: Specifically, the silane coupling agent in S1 is APTES, and the surface of the nano-silicon particles is modified by APTES, and then mixed with organic carbon sources such as glucose and carbonized at high temperature to form a Si-C chemically bonded composite material.

[0014] Specifically, the mass ratio of thermoplastic phenolic resin to polyacrylonitrile in S2 is controlled at 3-5:1.

[0015] Specifically, in step S2, a curing agent, hexamethyloltamine, is added simultaneously. After being evenly dispersed in a solvent, the mixture is heated and cured. Under an inert gas atmosphere, the temperature is increased to 800-1000℃ for 2-4 hours.

[0016] Specifically, after curing in S2, the carbon matrix is ​​further activated and pore-forming at 850°C under carbon dioxide gas for 1-2 hours to obtain a porous carbon matrix with a bimodal pore size distribution.

[0017] Specifically, in S3, the porous carbon precursor is mixed with boron-containing compounds and cerium phosphate in a mass ratio of 5-8:1:0.5-1, and then heat-treated at 800-1000℃ for 2-3 hours under argon atmosphere to obtain porous carbon with high mechanical strength.

[0018] Specifically, in step S4, porous carbon is first mixed with high-silica Y-type zeolite molecular sieve modified by grafting with trimethylchlorosilane, wherein the silicon-to-aluminum ratio is 20-30, and placed in a fluidized bed as a solid fluidizing medium to reconstruct the fluidized system; then silane is used as a gaseous silicon source.

[0019] Specifically, in step S4, silicon deposition is performed at 300-500°C, and the deposition rate and uniformity of silicon are controlled by gradient pulse method to obtain silicon-carbon precursor.

[0020] Specifically, in the triblock copolymer of S5, block A is polymerized from monomers containing crosslinking functional groups to form a chemical crosslinking network structure that buffers volume expansion; block B is an ion-conducting block polymerized from ion-conducting monomers to provide a continuous lithium-ion transport channel.

[0021] Specifically, in step S6, a nitrogen-doped carbon coating layer is formed on the material surface at 500-700°C, followed by low-temperature carbonization at 600-800°C under an inert atmosphere to rebuild the interface between silicon and the triblock copolymer and form strong chemical bonds.

[0022] Compared with the prior art, the beneficial effects of this application are as follows: This invention addresses the core technical challenges of silicon-carbon anode materials, such as rapid capacity decay, short cycle life, and poor rate performance, through full-chain interface regulation from silicon core pretreatment to final packaging. The resulting material exhibits excellent comprehensive electrochemical performance, providing key material support for the development of a new generation of high-energy-density lithium-ion batteries.

[0023] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This invention relates to a method for producing a novel silicon-carbon anode material. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention. Rather, embodiments of the invention include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0026] The following describes a method for preparing a high-performance silicon-carbon anode material based on interface design, according to an embodiment of the present invention, with reference to the accompanying drawings.

[0027] like Figure 1As shown, an embodiment of the present invention provides a method for preparing a high-performance silicon-carbon anode material based on interface design, comprising the following steps: S1: Dispersing nano-silicon particles in an organic solvent such as ethanol or toluene, and ultrasonically treating them to remove surface impurities and promote dispersion; then adding a silane coupling agent, and heating under nitrogen protection under reflux to form Si-O-Si bonds with the surface of the silicon particles, while introducing amino functional groups; finally, converting the amino groups into hydroxyl groups through acylation or hydrolysis to form Si-OH functional groups; thus achieving pretreatment of the silicon core; S2: A porous carbon matrix is ​​prepared by using thermoplastic phenolic resin as the first precursor and polyacrylonitrile as the second precursor. The two precursors are mixed in a certain mass ratio and a curing agent, hexamethyloltrimethylenetetramine, and then the mixture is dispersed evenly in a solvent and heated to cure. The mixture is then carbonized under an inert gas and activated to form pores under carbon dioxide gas to obtain a porous carbon matrix with a bimodal pore size distribution. S3: The obtained porous carbon precursor is mixed with boron-containing compounds and cerium phosphate in a certain mass ratio and heat-treated under argon gas to obtain porous carbon with high mechanical strength. S4: Silicon material is uniformly distributed in the pores of a porous carbon matrix using plasma-assisted pulsed gradient chemical vapor deposition. S5: A triblock copolymer is coated on the surface of a silicon-carbon precursor; S6: Finally, chemical vapor deposition is used with methane as the carbon source to form a nitrogen-doped carbon coating layer on the material surface at high temperature. Then, low-temperature carbonization is carried out under inert gas to rebuild the interface between silicon and triblock copolymer and form strong chemical bonds.

[0028] The silane coupling agent in S1 is APTES. The surface of the nano-silicon particles is modified by APTES and then mixed with organic carbon sources such as glucose and carbonized at high temperature to form a Si-C chemically bonded composite material. First, 2.0 g of nano-silicon particles are weighed and placed in a 500 mL three-necked flask, and 200 mL of anhydrous ethanol is added. The flask is placed in an ultrasonic cleaner and ultrasonically treated at 40 °C for 1 hour to fully disperse the silicon particles and remove some of the natural oxide layer and impurities on the surface.

[0029] Add 5 mL of APTES dropwise to the suspension. Transfer the three-necked flask to a heated magnetic stirrer, assemble the condenser, and reflux at 80°C for 6 hours under nitrogen atmosphere. During this process, the hydrolysis products of APTES undergo a condensation reaction with the hydroxyl groups on the surface of silicon particles to form strong Si-O-Si bonds, thereby introducing amino functional groups onto the silicon surface.

[0030] After the functional group transformation reaction was completed, the product was naturally cooled to room temperature. The solid product was collected by vacuum filtration, washed three times with anhydrous ethanol, and dried in a vacuum drying oven at 80°C for 12 hours to obtain aminated silicon nanoparticles.

[0031] The above-mentioned aminated silicon nanoparticles were thoroughly mixed and ground with 1.0 g of glucose in an agate mortar for 30 minutes. The mixture was then transferred to a tube furnace and carbonized under argon gas by heating to 700°C at 5°C / min and holding for 2 hours. During this process, glucose carbonized to form an amorphous carbon layer and may react with the amino groups on the surface to initially construct a strong Si-C interface, thus obtaining a carbon-coated Si-C bonded precursor.

[0032] In S2, the mass ratio of thermoplastic phenolic resin to polyacrylonitrile is controlled at 3-5:1. Simultaneously, hexamethyloltrimethylenetetramine (HMT) is added as a curing agent. After uniform dispersion in the solvent, the mixture is heated and cured. Under inert gas, the temperature is increased at 5-10℃ / min to 800-1000℃ for 2-4 hours for carbonization. Subsequently, it is activated and pore-forming at 850℃ under carbon dioxide gas for 1-2 hours, resulting in a porous carbon matrix with a bimodal pore size distribution. 3.0 g of thermoplastic phenolic resin and 1.0 g of polyacrylonitrile are weighed and added to a beaker containing 50 mL of NMP at a mass ratio of 3:1. 0.6 g of HMT is added as a curing agent, and the mixture is stirred for 4 hours in a high-speed mixer to form a uniform viscous liquid. The resulting liquid is transferred to a petri dish and cured in a 120℃ oven for 4 hours to obtain a hard solid precursor.

[0033] The cured precursor was crushed and ground into powder, then placed in a tube furnace. Under argon gas, the temperature was programmed to rise to 900°C at a rate of 5°C / min, and carbonized at this temperature for 3 hours. After the furnace temperature naturally dropped to 800°C, the protective gas was switched to carbon dioxide, and activation and pore formation were carried out at 850°C for 1.5 hours. This process creates a porous carbon matrix with a bimodal pore size distribution, consisting of macropores with a diameter of 50-100 nm and mesopores with a diameter of 2-5 nm.

[0034] S3 porous carbon precursor is mixed with boron-containing compounds and cerium phosphate in a mass ratio of 5-8:1:0.5-1, and then heat-treated at 800-1000℃ for 2-3 hours under argon atmosphere to obtain porous carbon with high mechanical strength.

[0035] The porous carbon matrix obtained from S2 was accurately weighed with boric acid and cerium phosphate in a mass ratio of 6:1:0.8, and then thoroughly mixed in an agate mortar for 30 minutes.

[0036] The mixture was placed in an alumina crucible, then placed in a tube furnace, and heated to 900°C at 3°C / min under argon gas for 2.5 hours.

[0037] After the reaction was complete, the mixture was allowed to cool naturally to room temperature, and the product was removed. This step, through the doping and compositing of boron and phosphorus, significantly enhanced the mechanical strength and toughness of the carbon framework.

[0038] In step S4, porous carbon is first mixed with high-silica Y-type zeolite molecular sieve grafted with trimethylchlorosilane, with a silicon-to-aluminum ratio of 20-30, and placed in a fluidized bed as a solid fluidizing medium to reconstruct the fluidization system. Subsequently, silicon deposition is carried out at 300-500℃ using silane as a gaseous silicon source, and the deposition rate and uniformity of silicon are controlled by gradient pulse method to obtain silicon-carbon precursor. High-strength porous carbon is then mixed with high-silica Y-type zeolite molecular sieve grafted with trimethylchlorosilane at a mass ratio of 1:0.5 and placed in a fluidized bed CVD reactor. The molecular sieve, as a solid fluidizing medium, can improve the fluidization state of porous carbon and ensure the uniformity of subsequent deposition.

[0039] The reactor temperature is then raised to 400°C, and the plasma generator is turned on to create a weak plasma atmosphere. Silane gas is then introduced in a gradient pulse pattern, with the pulse sequence being: 5 seconds of silane introduction followed by a 10-second interruption; the total deposition time is controlled at 60 minutes. This method can precisely control the silicon deposition rate and nucleation sites, achieving a highly uniform distribution of silicon within the porous carbon pores.

[0040] S5 is a triblock copolymer, wherein block A is polymerized from monomers containing crosslinking functional groups to form a chemical crosslinking network structure to buffer volume expansion; block B is an ion-conducting block polymerized from ion-conducting monomers to provide a continuous lithium-ion transport channel; the silicon-carbon precursor obtained in step S4 is dispersed in tetrahydrofuran solvent.

[0041] Weigh out 10% of the mass of the silicon-carbon precursor triblock copolymer, which has the following structure: block A - vinyltrimethoxysilane, providing crosslinking points; block B - ethylene oxide, providing lithium-ion conductivity; block C - styrene, providing mechanical strength, and dissolved in THF.

[0042] The polymer solution was slowly added dropwise to the silicon-carbon precursor suspension under vigorous stirring. After the addition was complete, stirring was continued for 6 hours, and then the solvent was removed by rotary evaporation.

[0043] The obtained powder was heat-treated at 60°C for 4 hours to hydrolyze and crosslink the siloxane groups in block A, forming an elastic three-dimensional network structure buffer layer.

[0044] In step S6, a nitrogen-doped carbon coating layer is formed on the material surface at 500-700℃, followed by low-temperature carbonization at 600-800℃ under an inert atmosphere to rebuild the interface between silicon and the triblock copolymer and form strong chemical bonds. The product of step S5 is placed in another CVD furnace, with methane as the carbon source and ammonia as the nitrogen source and carrier gas. The furnace temperature is raised to 600℃, and the reaction is carried out at this temperature for 1 hour to form a dense nitrogen-doped carbon coating layer on the outermost layer of the material.

[0045] Subsequently, under argon protection, the material was subjected to low-temperature carbonization treatment at 700℃ for 2 hours. This key step enables the partial carbonization of the internal triblock copolymer buffer layer and the formation of stronger chemical bonds with the inner silicon layer and the outer carbon shell, ultimately completing the reconstruction of the core-bridge-shell triple interface structure and obtaining a high-performance silicon-carbon anode composite material.

[0046] In summary, the present invention provides a method for preparing high-performance silicon-carbon anode materials based on interface design. First, when preparing silicon-carbon anode materials, the surface of nano-silicon particles is functionalized by introducing active groups onto their surface using a silane coupling agent, enhancing their interaction with the carbon source. Subsequently, the particles are mixed with a carbon source such as glucose and carbonized to initially form an amorphous carbon layer on the silicon surface, bonded by Si-C chemical bonds. This initial coating not only improves the conductivity of silicon but also constitutes the first interfacial buffer and constraint layer. Then, using thermoplastic phenolic resin and polyacrylonitrile as precursors, a porous carbon matrix with a bimodal pore size distribution is prepared through blending, curing, carbonization, and CO2 activation. The macropores facilitate silicon loading and electrolyte wetting, while the mesopores provide a high specific surface area. Further high-temperature heat treatment with boron-containing compounds and cerium phosphate was introduced to achieve multi-element doping and composite formation of B, P, and Ce, significantly enhancing the mechanical strength, toughness, and structural stability of the carbon framework and providing a robust and elastic three-dimensional support network to accommodate silicon volume changes. Simultaneously, plasma-assisted pulsed gradient chemical vapor deposition (PLC) was employed, using silane as the gas source, to gradually and uniformly deposit gaseous silicon atoms into the pores of porous carbon in a fluidized bed system. Pulse control and the plasma atmosphere effectively suppressed the excessively rapid agglomeration growth of silicon, achieving high dispersion and confined encapsulation of silicon nanounits within the carbon framework, thus alleviating the overall expansion stress of silicon agglomerates at the source. A customized triblock copolymer was then coated onto the surface of the silicon-carbon composite material. This polymer is ingeniously designed: one segment can crosslink to form an elastic network, directly buffering the volume expansion of silicon; the other segment provides a continuous lithium-ion transport channel. This polymer layer acts as a flexible bridge layer, absorbing mechanical stress while ensuring high-speed ion conduction. Finally, a dense nitrogen-doped carbon coating layer was formed on the outer surface of the entire material through chemical vapor deposition. This shell provides a stable electrode / electrolyte interface, suppresses side reactions, and ensures rapid electron transport. The subsequent low-temperature carbonization process is a crucial step, causing partial carbonization of the internal polymer buffer layer. This carbonizes the inner silicon-carbon interface and strongly bonds it to the outer nitrogen-doped carbon shell through newly formed chemical bonds, ultimately completing the chemical reconstruction of the triple interface of silicon core-polymer buffer bridge-carbon shell. This invention, through full-chain interface control from silicon core pretreatment to final encapsulation, synergistically solves the core technical challenges of rapid capacity decay, short cycle life, and poor rate performance in silicon-carbon anode materials. The resulting material exhibits excellent overall electrochemical performance, providing key material support for the development of next-generation high-energy-density lithium-ion batteries.

[0047] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0048] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0049] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing high-performance silicon-carbon negative electrode material based on interface design, comprising the following steps: S1: dispersing nano-silicon particles in an organic solvent such as ethanol or toluene, and ultrasonic treatment to remove surface impurities and promote dispersion; adding a silane coupling agent, heating and refluxing under nitrogen protection, allowing the coupling agent to form Si-O-Si bonds with the surface of the silicon particles, while introducing amino functional groups; finally, through acylation or hydrolysis reaction, the amino groups are converted into hydroxyl groups to form Si-OH functional groups; thus realizing the pretreatment of the silicon core; S2: using thermoplastic phenolic resin as the first precursor and polyacrylonitrile as the second precursor to prepare a porous carbon matrix, mixing them in a certain mass ratio, adding a curing agent hexamethylenetetramine, dispersing uniformly in a solvent, heating and curing, carbonizing under inert gas, and then activating and pore-forming under carbon dioxide gas to obtain a porous carbon matrix with a bimodal pore size distribution; S3: mixing the obtained porous carbon precursor with boron-containing compounds and cerium phosphate in a mass ratio, and heat-treating under argon gas to obtain a porous carbon with high mechanical strength; S4: uniformly distributing the silicon material in the pores of the porous carbon matrix by plasma-assisted pulsed gradient chemical vapor deposition; S5: coating a triblock copolymer on the surface of the silicon-carbon precursor; S6: finally, using chemical vapor deposition with methane as the carbon source to form a nitrogen-doped carbon coating layer on the surface of the material at high temperature, and then performing low-temperature carbonization treatment under inert gas to reconstruct the interface between silicon and the triblock copolymer and form strong chemical bonds.

2. The method for preparing high-performance silicon-carbon negative electrode material based on interface design according to claim 1, characterized in that: In S1, the silane coupling agent is APTES, which modifies the surface of the nano-silicon particles, and then mixes with organic carbon sources such as glucose and carbonizes at high temperature to form a Si-C chemically bonded composite material.

3. The method for preparing high-performance silicon-carbon negative electrode material based on interface design according to claim 1, characterized in that: In S2, the mass ratio of thermoplastic phenolic resin to polyacrylonitrile is controlled at 3-5:

1.

4. The method for preparing high-performance silicon-carbon negative electrode material based on interface design according to claim 3, characterized in that: In S2, the curing agent hexamethylenetetramine is added at the same time, and after uniform dispersion in a solvent, heating and curing, carbonization under inert gas at a temperature increasing rate of 5-10℃ / min to 800-1000℃ for 2-4 hours.

5. The method for preparing high-performance silicon-carbon negative electrode material based on interface design according to claim 4, characterized in that: In S2, after curing, continue to activate and pore-forming under carbon dioxide gas at 850℃ for 1-2 hours to obtain a porous carbon matrix with a bimodal pore size distribution.

6. The method for preparing high-performance silicon-carbon negative electrode material based on interface design according to claim 1, characterized in that: In S3, the porous carbon precursor is mixed with boron-containing compounds and cerium phosphate in a mass ratio of 5-8:1:0.5-1, and heat-treated under argon gas at 800-1000℃ for 2-3 hours to obtain a porous carbon with high mechanical strength.

7. The method of claim 1, wherein the method is characterized by: In S4, the porous carbon is first mixed with high-silicon Y-type zeolite molecular sieves modified by trimethylchlorosilane grafting, with a silicon-aluminum ratio of 20-30, placed in a fluidized bed as a solid fluidization medium, and the fluidization system is reconstructed; then silane is used as a gaseous silicon source.

8. The method for preparing high-performance silicon-carbon negative electrode material based on interface design according to claim 1, characterized in that: In S4, silicon deposition is carried out at 300-500℃, and the deposition rate and uniformity of silicon are controlled by gradient pulse to obtain a silicon-carbon precursor.

9. The method for preparing high-performance silicon-carbon negative electrode material based on interface design according to claim 1, characterized in that: In S5, the triblock copolymer, in which block A is polymerized from a cross-linking functional group-containing monomer to form a chemical cross-linking network structure to buffer volume expansion; block B is an ion-conducting block polymerized from an ion-conducting monomer to provide a continuous lithium ion transmission channel.

10. The method for preparing high-performance silicon-carbon negative electrode material based on interface design according to claim 1, characterized in that: The S6 forms a nitrogen-doped carbon coating layer on the surface of the material at 500-700 DEG C, and then low-temperature carbonization treatment is carried out at 600-800 DEG C in an inert atmosphere, the interface between silicon and the triblock copolymer is reconstructed, and a strong chemical bond is formed.

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