Preparation method of high-performance carbon framework material for silicon-carbon negative electrode material

Abstract

The invention discloses a preparation method of a high-performance porous carbon framework material for a silicon-carbon negative electrode material, which comprises the following steps of: firstly, impregnating fruit shell-based or wood-based high-specific-surface-area activated carbon by using a titanium oxalate solution, and chambering the activated carbon by using carbon dioxide as an activating agent under the catalysis of a titanium element to obtain porous carbon with reasonable pore size distribution; titanium and carbon generate titanium carbide at high temperature, so that the strength of the porous carbon is enhanced. And impregnating the porous carbon with copper acetate, and depositing copper element on micropores and the surface of the porous carbon to obtain the titanium-copper modified porous carbon framework material. According to the method disclosed by the invention, the titanium is impregnated in the activated carbon, so that not only can a catalytic chambering effect be achieved, the content of micropores of 2-10nm be increased, but also titanium carbide can be generated with carbon at a high temperature, the effect of enhancing the strength of the carbon framework material is achieved, and the strength of the carbon framework material is more than or equal to 99%; through the method of depositing copper in the micropores of the porous carbon, the permeation wettability of the nano silicon in the micropores of the porous carbon can be improved, and the conductivity of the carbon framework material is improved.

Description

Technical Field

[0001] The present invention belongs to the field of electrode materials. More specifically, the present invention relates to a preparation method of a high-performance carbon skeleton material for silicon-carbon anode materials. Background Art

[0002] The mass specific capacity of silicon anode materials can reach up to 4200 mAh / g, which is much larger than 372 mAh / g of carbon anode materials. It is one of the materials with high theoretical specific capacity for use as lithium / sodium battery anode materials. However, problems such as low cycle life, large volume change, and continuous generation of SEI film in silicon anode materials restrict the application of silicon anode materials. Combining silicon with carbon can effectively improve these problems. Therefore, silicon-carbon anode materials are the current development focus of lithium / sodium battery anode materials.

[0003] In order to solve many problems such as fast cycle decay, low initial efficiency, pole piece expansion and shedding, and low conductivity caused by volume expansion during the lithium intercalation process of silicon-based anode materials itself, researchers have been working hard to make improvements. Silicon anode materials have gone through and involved four stages: nanosizing, surface coating, compounding, and cavity construction, forming four types of silicon-based anode materials mainly based on silicon oxide and silicon carbon. The main technical development paths are sanded silicon carbon (the first generation), coated silicon oxide (the second generation), pre-lithiated and pre-magnesiated silicon oxide (the third generation), and chemical vapor deposition silicon carbon (the fourth generation).

[0004] The fourth-generation chemical vapor deposition silicon carbon uses the method of chemical vapor deposition (CVD) and uses a micro-nano carbon skeleton as the cavity construction method for the main structure. Nano-silicon is deposited in the micropores inside the carbon skeleton to stabilize the volume expansion of silicon particles during charge and discharge.

[0005] In the fourth-generation deposited silicon carbon anode material, on the one hand, the carbon material skeleton should play a role in structural support to form a cavity, and on the other hand, it should provide appropriate micropores to confine the deposited silicon particles within the nanometer range. A carbon skeleton material with a certain microporous structure and composition is beneficial to improving the specific capacity of the silicon-carbon anode material. A carbon skeleton material with good mechanical properties is beneficial to resisting the stress release during the volume change of the silicon material during charge and discharge cycles; a conductive network formed by a carbon skeleton material with good electrical conductivity is beneficial to improving the overall conductivity of the electrode.

[0006] Currently, for economic reasons, activated carbon is preferably used as the carbon skeleton material. However, it is difficult for activated carbon to meet the requirements of high-performance silicon-carbon anode materials in terms of pore size composition, appropriate mesopore ratio, strength, and conductivity. Especially in the case of high mesopore ratio and high silicon loading requirements, these defects are particularly prominent. And it directly affects the conductivity, thermal conductivity, resistance to expansion and shedding, and toughness of the negative electrode.

[0007] The good mechanical properties, surface properties, electrical conductivity and microporous composition of the carbon skeleton material directly or indirectly affect the performance of the silicon-carbon anode material. Therefore, the present application aims to invent a preparation method of a carbon skeleton for a silicon-carbon anode material with high mechanical strength, good electrical conductivity and well-developed mesopores. Summary of the Invention

[0008] One object of the present invention is to solve at least the above problems and provide at least the advantages described hereinafter.

[0009] One object of the present invention is to provide a preparation method of a high-performance carbon skeleton material for a silicon-carbon anode material, and the prepared carbon skeleton material has properties such as reasonable microporous composition, good electrical conductivity, high mechanical strength and high silicon deposition rate.

[0010] To achieve these objects and other advantages of the present invention, there is provided a preparation method of a high-performance carbon skeleton material for a silicon-carbon anode material, which comprises the following steps: 1) Impregnating activated carbon with a titanyl oxalate solution, dehydrating and drying to obtain pretreated carbon; 2) Placing the pretreated carbon in an activation furnace for treatment to decompose and evaporate oxalic acid, then introducing an inert gas into the activation furnace, raising the temperature, and subsequently introducing CO 2 gas, and performing activation and pore expansion under the catalysis of titanium to obtain highly mesoporous porous carbon loaded with titanium carbide; the activation furnace can be a rotary furnace or a static furnace or other forms of activation furnaces; 3) Grinding and pulverizing the highly mesoporous porous carbon loaded with titanium carbide to obtain porous carbon powder; 4) Impregnating the porous carbon powder with a copper acetate solution and drying to obtain porous carbon loaded with copper; 5) Shaping the porous carbon loaded with titanium and copper to reach the particle size required for the silicon-carbon anode material, thus obtaining the high-performance carbon skeleton material for the silicon-carbon anode material.

[0011] Preferably, in step 1), the activated carbon has a particle size of 0.25 - 0.3 mm, a specific surface area of 1400 - 1600 m 2 / g, and an ash content of ≤0.2%. The activated carbon is one of fruit shell activated carbons such as coconut shell or wood carbon.

[0012] Preferably, in step 1), the activated carbon is subjected to impurity removal and purification treatment, and its ash content is ≤0.2%; the suspension of the activated carbon is adjusted to pH 3 - 7 with one of oxalic acid, acetic acid, and citric acid. More preferably, the pH is 6.0 - 6.5.

[0013] Preferably, the mass concentration of titanyl oxalate is 0.5 - 5%.

[0014] Preferably, the preparation method of titanium oxalate is to react concentrated oxalic acid with titanium powder at a mass ratio of 1:1, with the reaction temperature being 110 - 130 °C, the reaction lasting for at least 3 h, and then diluting with deionized water to obtain a titanium oxalate solution.

[0015] Preferably, in step 1), under the action of ultrasonic waves, the activated carbon is impregnated with the titanium oxalate solution for 4 - 8 h; the drying temperature is 100 - 110 °C, and the drying time is 12 - 48 h.

[0016] Preferably, in step 2), the pretreated carbon is placed in an activation furnace at 250 - 350 °C for 1 - 2 h to decompose and evaporate the oxalic acid; the inert gas introduced is nitrogen or argon, the temperature is raised to 850 - 1250 °C, and the reaction lasts for 0.5 - 1 h. The total amount of CO 2 gas introduced is 0.02 - 0.03 m 3 / min•kg, the activation and pore - expansion temperature is 650 - 850 °C, and the activation and pore - expansion time is 1 - 2 h.

[0017] Preferably, the particle size of the porous carbon powder is below 20 μm; the particle size of the porous carbon powder conforms to the regulations in GB / T38823.

[0018] Preferably, the copper oxide powder is mixed with a 1 - 10% acetic acid solution, stirred and reacted for 3 - 6 hours, the reaction temperature is 50 - 150 °C, the solid - liquid ratio is 1:2 - 10, and after the reaction ends, it is diluted with deionized water to 5 - 10% to obtain a copper acetate solution.

[0019] Preferably, in step 4), under the condition that the temperature is less than 40 °C, the porous carbon powder is impregnated with the copper acetate solution for 4 - 8 hours, and spray - drying is carried out at a temperature of 200 - 300 °C to obtain copper - loaded porous carbon.

[0020] The present invention has at least the following beneficial effects: First, the present invention introduces titanium elements on the surface and microporous walls of the activated carbon to form titanium carbide, improving the mechanical strength of the porous carbon, enhancing the strength of the porous carbon against external force damage, and avoiding the fragmentation of particles and the collapse of micropores during subsequent use. Second, the carbon - skeleton material prepared by the method of the present invention reduces the resistivity of the carbon skeleton of the silicon - carbon anode material, improves the electrical conductivity of the carbon skeleton of the silicon - carbon anode material, and thus improves the electrical conductivity of the silicon - carbon anode. Third, the present invention expands the pores of the activated carbon under the catalysis of titanium elements to form a large number of 2 - 10 nm micropores that are beneficial for the adsorption and deposition of silane, which is conducive to improving the silane adsorption rate in the micropores of the porous carbon. Fourth, the present invention introduces copper elements on the pore walls of the activated carbon. In the presence of copper elements, the wettability of silicon in the micropores of the porous carbon is improved, the amount of silane entering the micropores is promoted, the deposition and cracking efficiency of silane are increased, and the deposition rate of nano - silicon in the micropores of the porous carbon is improved.

[0021] Other advantages, objects and features of the present invention will be partly reflected by the following description, and partly will be understood by those skilled in the art through the research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a graph showing the relationship between pore volume and pore diameter of the carbon skeleton prepared by the method of Example 3 of the present invention; Figure 2 It is a graph showing the relationship between pore volume and pore diameter of the carbon skeleton prepared by the method of Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0023] The following further describes the present invention in detail with reference to the drawings, so that those skilled in the art can implement it according to the description in the specification.

[0024] It should be understood that the terms such as "having", "comprising" and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0025] It should be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified.

[0026] <Example 1> A preparation method of a high-performance carbon skeleton material for silicon-carbon anode materials, which includes the following steps: 1) Under the action of ultrasonic waves, activated carbon with a particle size of 0.25 - 0.3 mm, an ash content of ≤ 0.2%, and a specific surface area of 1450 ± 30 m 2 / g is impregnated with oxalic acid titanium solution for 8 h, dehydrated, and dried. The drying temperature is 110 ± 5 °C, and the drying time is 20 h to obtain pretreated carbon; the suspension of activated carbon is adjusted to pH 6 - 6.5 with one of oxalic acid, acetic acid, and citric acid and then impregnated with oxalic acid titanium; the preparation method of oxalic acid titanium is to react concentrated oxalic acid and titanium powder with a mass ratio of 1:1 at a reaction temperature of 120 ± 5 °C for 4 h, and then dilute it with deionized water to 0.5% to obtain oxalic acid titanium solution; the purity of concentrated oxalic acid is greater than 99%, and the purity of titanium powder is greater than 99.5%; 2) The pretreated carbon is placed in an activation furnace at 210 ± 10 °C for 2 h to decompose and evaporate oxalic acid, and then inert gas argon is introduced into the activation furnace, the temperature is raised to 950 ± 50 °C, and the reaction is carried out for 2 h. Subsequently, CO 2 gas is introduced into the activation furnace, and activation and pore expansion are carried out under the catalysis of titanium. The furnace temperature is controlled at 700 ± 50 °C, and the reaction is carried out for 1 h. The total amount of CO 2 gas introduced is 0.03 m 3 / min•kg (CO required per kg of activated carbon)2 The gas volume), to obtain highly mesoporous porous carbon loaded with titanium carbide; 3) Grind and pulverize the highly mesoporous porous carbon loaded with titanium carbide to less than 20 µm to obtain porous carbon powder; 4) Impregnate the porous carbon powder with a copper acetate solution, and dry it to obtain porous carbon loaded with copper; Mix copper oxide powder with 10% acetic acid solution, stir and react for 6 hours, the reaction temperature is 130 - 150 °C, the solid-liquid ratio is 1:10, after the reaction ends, dilute it with deionized water to 10% to obtain a copper acetate solution; At a temperature of 30 °C, impregnate the porous carbon powder with the copper acetate solution for 8 hours, and perform drying by spray drying at a temperature of 300 ± 10 °C to obtain porous carbon loaded with copper; 5) Shape the porous carbon loaded with copper to reach the particle size required for the silicon-carbon anode material, that is, obtain a high-performance carbon skeleton material for the silicon-carbon anode material.

[0027] <Example 2> A preparation method of a high-performance carbon skeleton material for a silicon-carbon anode material, which includes the following steps: 1) Under the action of ultrasonic waves, impregnate activated carbon with a particle size of 0.25 - 0.3 mm and a specific surface area of 1550 ± 30 m 2 / g with a titanium oxalate solution for 6 h, dehydrate, and perform drying treatment, the drying temperature is 110 ± 5 °C, the drying time is 30 h, to obtain pretreated carbon; Among them, the activated carbon has been subjected to impurity removal and purification treatment, the ash content ≤ 0.2%, and the suspension of the activated carbon is adjusted to pH 6 - 6.5 with one of oxalic acid, acetic acid, and citric acid and then impregnated with titanium oxalate; The preparation method of titanium oxalate is to react concentrated oxalic acid and titanium powder with a mass ratio of 1:1, the reaction temperature is 120 ± 5 °C, the reaction is 4 h, and it is diluted with deionized water to 3% to obtain a titanium oxalate solution; 2) Place the pretreated carbon in an activation furnace at 300 ± 10 °C for 1.5 h to decompose and evaporate the oxalic acid, then introduce the inert gas nitrogen into the activation furnace, raise the temperature to 1050 ± 50 °C, react for 1 h, and then introduce CO 2 gas into the activation furnace, perform activation and pore expansion under the catalysis of titanium, control the furnace temperature at 800 ± 50 °C, react for 1 h, and the total amount of CO 2 gas introduced is 0.025 m 3 / min•kg (the amount of CO 2 gas required per kg of activated carbon), to obtain highly mesoporous porous carbon loaded with titanium carbide; 3) Grind and pulverize the highly mesoporous porous carbon loaded with titanium carbide to less than 20 µm to obtain porous carbon powder; 4) Impregnate the porous carbon powder with a copper acetate solution, and dry it to obtain copper-loaded porous carbon; mix copper oxide powder with 10% acetic acid solution, stir and react for 5 hours, the reaction temperature is 100 - 120 °C, the solid-liquid ratio is 1:5, after the reaction ends, add deionized water to dilute it to 7% to obtain a copper acetate solution; under the condition of a temperature of 30 °C, impregnate the porous carbon powder with the copper acetate solution for 8 hours, and perform drying by spray drying under the condition of a temperature of 250 ± 5 °C to obtain copper-loaded porous carbon; 5) Shape the copper-loaded porous carbon to reach the particle size required for the silicon-carbon anode material, and thus obtain the high-performance carbon skeleton material for the silicon-carbon anode material.

[0028] <Example 3> A preparation method of a high-performance carbon skeleton material for a silicon-carbon anode material, which comprises the following steps: 1) Under the action of ultrasonic waves, impregnate activated carbon with a particle size of 0.25 - 0.3 mm and a specific surface area of 1600 ± 30 m 2 / g with a titanyl oxalate solution for 8 h, dehydrate, and perform drying treatment, the drying temperature is 110 ± 5 °C, the drying time is 30 h, to obtain pretreated carbon; wherein, the activated carbon has been subjected to impurity removal and purification treatment, the ash content ≤ 0.2%, and the suspension of the activated carbon is adjusted to pH 6 with one of oxalic acid, acetic acid, and citric acid and then impregnated with titanyl oxalate; the preparation method of titanyl oxalate is to react concentrated oxalic acid and titanium powder with a mass ratio of 1:1, the reaction temperature is 120 ± 5 °C, the reaction is 4 h, add deionized water to dilute it to 3% to obtain a titanyl oxalate solution; 2) Place the pretreated carbon in an activation furnace at 250 ± 10 °C for 1.5 h to decompose and evaporate oxalic acid, then introduce inert gas nitrogen into the activation furnace, raise the temperature to 1150 ± 50 °C, react for 1 h, and then introduce CO 2 gas into the activation furnace, and perform activation and pore expansion under the catalysis of titanium, the furnace temperature is controlled at 850 ± 50 °C, react for 1 h, and the total amount of CO 2 gas introduced is 0.025 m 3 / min•kg (the amount of CO 2 gas required per kg of activated carbon), to obtain highly mesoporous porous carbon loaded with titanium carbide; 3) Grind and crush the highly mesoporous porous carbon loaded with titanium carbide to less than 20 µm to obtain porous carbon powder; 4) Impregnate the porous carbon powder with a copper acetate solution, and dry it to obtain copper-loaded porous carbon; mix copper oxide powder with 10% acetic acid solution, stir and react for 5 hours, the reaction temperature is 100 ± 5 °C, the solid-liquid ratio is 1:5, after the reaction ends, dilute it with deionized water to 7% to obtain a copper acetate solution. Under the condition of a temperature of 30 °C, impregnate the porous carbon powder with the copper acetate solution for 8 hours, and carry out drying by spray drying under the condition of a temperature of 300 ± 10 °C to obtain copper-loaded porous carbon; 5) Shape the copper-loaded porous carbon to reach the particle size required for the silicon-carbon anode material, that is, obtain a high-performance carbon skeleton material for the silicon-carbon anode material.

[0029] The relationship diagram between the mesopore volume and pore diameter of the carbon skeleton material prepared in Example 3 is as Figure 1 shown. It can be seen from the figure that the mesopores are basically distributed in the range of 2-10 nm, and the main body is 2-6 nm. From Figure 1 and Figure 2 it can be seen that Figure 1 the micropore volume of 1-10 nm in Figure 2 is significantly higher than that of

[0030] <Effect test> Comparative Example 1 is not treated with titanium and copper, that is, the following method steps are adopted: 1) Remove impurities and purify the activated carbon with a particle size of 0.25-0.3 mm and a specific surface area of 1600 ± 30 m 2 / g, the ash content ≤ 0.2%, and carry out drying treatment, the drying temperature is 110 ± 5 °C, and the drying time is 30 h; 2) Then feed it into an activation furnace into which CO 2 gas is introduced for activation and pore expansion, the furnace temperature is controlled at 850 ± 30 °C, react for 1 h, and the total amount of CO 2 gas introduced is 0.025 m 3 / min•kg (the amount of CO 2 gas required per kg of activated carbon); 3) Shape the porous carbon to reach the particle size required for the silicon-carbon anode material, that is, obtain a carbon skeleton material for the silicon-carbon anode material.

[0031] Comparative Example 2 is not treated with titanium, that is, the following method steps are adopted: 1) The activated carbon with a particle size of 0.25-0.3 mm and a specific surface area of 1600 ± 30 m 2 / g is subjected to impurity removal and purification treatment, and the ash content ≤ 0.2%. Subsequently, it is fed into an activation furnace into which CO 2 gas is introduced for activation and pore expansion, the furnace temperature is controlled at 850 ± 50 °C, react for 1 h, and CO2 The total amount of gas introduced is 0.025 m 3 / min•kg (the amount of CO required per kg of activated carbon 2 gas volume), 2) Grind and crush the activated carbon to less than 20 µm to obtain porous carbon powder; 3) Impregnate the porous carbon powder with copper acetate solution, and dry it to obtain copper-loaded porous carbon; Mix copper oxide powder with 10% acetic acid solution, stir and react for 5 hours, the reaction temperature is 100 ± 5 °C, the solid-liquid ratio is 1:5, after the reaction is completed, dilute it with deionized water to 7% to obtain copper acetate solution. Under the condition of a temperature of 30 °C, impregnate the porous carbon powder with copper acetate solution for 8 hours, and dry it by spray drying under the condition of a temperature of 300 ± 10 °C to obtain copper-loaded porous carbon; 4) Shape the copper-loaded porous carbon to reach the particle size required for the silicon-carbon anode material, and thus obtain the carbon skeleton material for the silicon-carbon anode material.

[0032] Comparative Example 3 is without copper treatment, that is, the following steps are adopted: 1) Under the action of ultrasonic waves, impregnate activated carbon with a particle size of 0.25 - 0.3 mm, an ash content of ≤0.2%, and a specific surface area of 1600 ± 30 m 2 / g with oxalic acid titanium solution for 8 h, dehydrate, and perform drying treatment, the drying temperature is 110 ± 5 °C, the drying time is 30 h, to obtain pretreated carbon; Among them, the activated carbon is subjected to impurity removal and purification treatment, and the suspension of the activated carbon is adjusted to pH 6 with one of oxalic acid, acetic acid, and citric acid and then impregnated with oxalic acid titanium; The preparation method of oxalic acid titanium is to react concentrated oxalic acid and titanium powder with a mass ratio of 1:1, the reaction temperature is 120 ± 5 °C, the reaction is 34 h, and it is diluted with deionized water to 3% to obtain oxalic acid titanium solution; 2) Place the pretreated carbon in an activation furnace at 250 ± 10 °C for 1.5 h to decompose and evaporate oxalic acid, then introduce inert gas nitrogen into the activation furnace, raise the temperature to 1150 ± 50 °C, react for 1 h, and then introduce CO 2 gas for activation and pore expansion, control the furnace temperature at 850 ± 30 °C, react for 1 h, CO 2 The total amount of gas introduced is 0.025 m 3 / min•kg (the amount of CO required per kg of activated carbon 2 gas volume), to obtain highly mesoporous porous carbon loaded with titanium carbide; 3) Shape the titanium-loaded porous carbon to reach the particle size required for the silicon-carbon anode material, and thus obtain the carbon skeleton material for the silicon-carbon anode material.

[0033] Detect the strength, resistivity, specific surface area, total pore volume, and micropore volume distribution of the product, and the results are shown in Table 1.

[0034] Wherein: The strength is measured in accordance with GB / T 12496.6 "Test Methods for Wood Activated Carbon - Determination of Strength".

[0035] The ash content is measured in accordance with GB / T 12496.3 "Test Methods for Wood Activated Carbon - Determination of Ash Content".

[0036] The resistivity is measured with reference to GB / T 30835 "Carbon Composite Lithium Iron Phosphate Cathode Material for Lithium - Ion Batteries" according to the four - probe powder resistivity measurement method.

[0037] The specific surface area and pore size distribution are measured in accordance with GB / T 21650.3 "Determination of Pore Size Distribution and Porosity of Solid Materials by Mercury Intrusion and Gas Adsorption - Part 3: Gas Adsorption Method for Analysis of Micropores", and the results are by the NLDFT method.

[0038] Table 1 From the results in Table 1, it can be seen that the strength of the carbon skeleton materials prepared by the methods of Examples 1 - 3 and Comparative Example 3 is higher than that of Comparative Example 1 and Comparative Example 2, indicating that the strength of the carbon skeleton materials can be improved by treatment with titanium oxalate. The specific surface area of Examples 1 - 3 is smaller than that of Comparative Example 1, indicating that titanium and copper are deposited in the micropores of the activated carbon, thus reducing the specific surface area of the activated carbon. The average pore diameter of Examples 1 - 3 is larger than that of Comparative Example 1. The possible reason is that CO 2 The activated carbon is continuously expanded to form more mesopores, so that the average pore diameter is larger than that of Comparative Example 1. The pore size distribution of 2 - 10 nm in Examples 1 - 3 of the present invention is significantly higher than that of Comparative Example 1. The possible reason is that in Examples 1 - 3, under the catalysis of titanium, the CO2 pore - expanding process of the porous carbon easily forms pores of 2 - 10 nm, creating more micropores with a pore size of 2 - 10 nm. The resistivity of the examples is significantly lower than that of Comparative Example 1, indicating that the addition of titanium and copper can improve the electrical conductivity of the carbon skeleton materials.

[0039] Although the embodiments of the present invention have been disclosed as above, they are not limited to only the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to specific details and the examples shown and described herein.

Claims

1. A method for preparing a high-performance carbon skeleton material for a silicon-carbon negative electrode material, characterized in that: The following steps are involved: 1) Using titanium oxalate solution to impregnate activated carbon, dehydrate, and dry to obtain pretreated carbon; 2) The pretreated carbon is placed in an activation furnace to decompose and evaporate the oxalic acid, and then an inert gas is introduced into the activation furnace to increase the temperature, and then CO2 gas is introduced into the activation furnace to activate and expand the pores under the catalysis of titanium to obtain a porous carbon with high mesoporosity loaded with titanium carbide; 3) grinding and crushing the high mesoporous porous carbon loaded with titanium carbide to obtain porous carbon powder; 4) impregnating porous carbon powder with a copper acetate solution and drying the porous carbon to obtain copper-loaded porous carbon; 5) The copper-loaded porous carbon is shaped to achieve the particle size required for the silicon-carbon negative electrode material, thereby obtaining a high-performance carbon skeleton material for the silicon-carbon negative electrode material.

2. The method for preparing a high-performance carbon skeleton material for a silicon-carbon negative electrode material according to claim 1, characterized in that: In step 1), the particle size of the activated carbon is 0.2-0.3 mm and the specific surface area is not less than 1400 m 2 / g, ash content ≤0.2%.

3. The method for preparing a high-performance carbon skeleton material for a silicon-carbon negative electrode material according to claim 1, characterized in that: In step 1), the activated carbon is treated with impurities removal and purification, and the activated carbon suspension is adjusted to pH 3-7 with one of oxalic acid, acetic acid and citric acid.

4. The method for preparing a high-performance carbon skeleton material for a silicon-carbon negative electrode material according to claim 1, characterized in that: The mass concentration of titanium oxalate is 0.5-5%.

5. The method for preparing a high-performance carbon skeleton material for a silicon-carbon negative electrode material according to claim 1, characterized in that: The preparation method of titanium oxalate is to react concentrated oxalic acid with titanium powder in a mass ratio of 1:1, the reaction temperature is 110-130°C, and the reaction time is not less than 3 hours to obtain a titanium oxalate solution.

6. The method for preparing a high-performance carbon skeleton material for a silicon-carbon negative electrode material according to claim 1, characterized in that: In step 1), the activated carbon is impregnated with titanium oxalate solution under the action of ultrasound for 4-8 h; the drying temperature is 110±5°C, and the drying time is 12-48 h.

7. The method for preparing a high-performance carbon skeleton material for a silicon-carbon negative electrode material according to claim 1, characterized in that: In step 2), the pretreated carbon is placed in an activation furnace at 200-300 °C for 1-2 h to decompose and evaporate the oxalic acid; the inert gas introduced is nitrogen or argon, the temperature is raised to 800-1200 °C, the reaction is carried out for 0.5-1 h, and the total amount of CO2 gas introduced is 0.02-0.03 m 3 / min•kg, the activation expansion temperature is 600-800℃, and the activation expansion time is 1-2 h.

8. The method for preparing a high-performance carbon skeleton material for a silicon-carbon negative electrode material according to claim 1, characterized in that: The particle size of the porous carbon powder is 20 μm or less.

9. The method for preparing a high-performance carbon skeleton material for a silicon-carbon negative electrode material according to claim 1, characterized in that: Mix copper oxide powder with 1-10% acetic acid solution, stir and react for 3-6 hours, the reaction temperature is 50-150°C, the solid-liquid ratio is 1:2-10, and after the reaction is completed, add deionized water to dilute to 5-10% to obtain a copper acetate solution.

10. The method for preparing a high-performance carbon skeleton material for a silicon-carbon negative electrode material according to claim 1, characterized in that: In step 4), the porous carbon powder is impregnated with a copper acetate solution at a temperature below 40° C. for 4-8 hours, and then dried at a temperature of 200-300° C. by a spray drying method to obtain a porous carbon loaded with copper.

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