High-performance lithium ion battery porous carbon negative electrode material and preparation method thereof

Abstract

The invention relates to the technical field of lithium ion battery materials, in particular to a high-performance lithium ion battery porous carbon negative electrode material and a preparation method thereof.The preparation method comprises the following steps that S1, a hard template material and a carbon precursor material are subjected to ball milling and mixing to obtain a template / carbon mixed material; s2, mixing the template / carbon mixed material with a pore forming agent, grinding, and sieving to obtain a nano mixed material; s3, the nanometer mixed material is subjected to preheating treatment, pyrolysis modification is conducted after preheating is completed, a nitrogen-doped template carbon nanometer product is obtained, the preheating temperature ranges from 300 DEG C to 500 DEG C, the preheating time ranges from 3 h to 6 h, the pyrolysis temperature ranges from 600 DEG C to 1000 DEG C, and the pyrolysis time ranges from 0.5 h to 24 h; and S4, placing the nitrogen-doped template carbon nano-product in a template removing agent solution for reaction to obtain a nano-mixed solution, and centrifuging, washing and drying the nano-mixed solution to obtain the porous carbon negative electrode material of the lithium ion battery. The prepared porous carbon negative electrode material of the lithium ion battery is good in conductivity, and the diffusion rate of lithium ions under the low-temperature condition can be effectively increased.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium ion battery materials, and in particular to a high-performance lithium ion battery porous carbon negative electrode material and a preparation method thereof. Background Art

[0002] Energy storage devices are an important cornerstone for promoting the country's information development and modernization process. Among them, lithium-ion batteries have been widely used in electric vehicles, rail transportation, aerospace and other fields due to their advantages such as high operating voltage, high energy density, environmental friendliness and no memory effect. However, with the rapid development of military-civilian integration, military and civilian science and technology, and modernization, the demand for ultra-low temperature lithium-ion batteries in high-cold areas such as plateaus, deep seas, and polar regions, as well as extremely cold areas such as high altitudes and space, which have important scientific research significance and national defense strategic value, is increasing. The demand for low-temperature resistant lithium-ion batteries that meet the applications of new energy vehicles, 5G base stations, military drones and Beidou navigation systems has also surged. Traditional lithium-ion batteries can no longer meet people's needs for energy storage and release in the above-mentioned low-temperature environment areas. Therefore, it is urgent to develop lithium-ion batteries and their electrode materials with excellent low-temperature performance.

[0003] Graphite is the most commonly used negative electrode material in the lithium battery industry. However, at low temperatures, the diffusion rate of lithium ions between graphite layers slows down, and the kinetics of lithium ion insertion / extraction in the graphite negative electrode slows down; the overpotential caused by the slow kinetics makes the actual potential of graphite lithium insertion close to or even lower than the lithium metal deposition potential, thus causing lithium precipitation. The dendrites produced by uneven lithium deposition will increase the internal resistance of the battery, reduce capacity, reduce life, and cause safety issues.

[0004] Studies have found that porous structures can provide fast transmission channels for lithium ions, reduce the diffusion distance of lithium ions in electrode materials, and accelerate the diffusion rate of lithium ions, thereby accelerating the charging and discharging speed. Among them, porous carbon, as an emerging product, is widely used in various fields and is a new material with great potential. In the prior art, the invention patent with application publication number CN118206104A discloses a porous carbon negative electrode material with rich pore structure, using starch as a carbon precursor and magnesium gluconate as a template agent using a hard template method; after ball milling, coke pretreatment, crushing, pickling, and high-temperature carbonization treatment, a porous carbon material with a high specific surface area is prepared. However, the porous carbon negative electrode material prepared by this method has a small pore size, concentrated in micropores (<2nm), and the pore size is not easy to control. The diffusion rate of lithium ions is slow when used, and two-step high-temperature carbonization is required, and the process is relatively complicated.

[0005] Therefore, it is necessary to study a high-performance lithium-ion battery porous carbon negative electrode material with excellent pore structure and adjustable pore size, which can effectively improve the diffusion rate of lithium ions under low temperature conditions. Summary of the invention

[0006] The present invention is made to solve the above-mentioned problems, and its purpose is to provide a high-performance lithium-ion battery porous carbon negative electrode material and a preparation method thereof having an excellent pore structure and adjustable pore size, which can effectively improve the diffusion rate of lithium ions under low temperature conditions, aiming to solve one or more of the above-mentioned problems and other potential problems.

[0007] In a first aspect, the present invention provides a method for preparing a high-performance porous carbon negative electrode material for a lithium-ion battery, characterized in that the method comprises the following steps: S1, ball-milling a hard template material and a carbon precursor material to obtain a template / carbon mixed material; S2, mixing the template / carbon hybrid material with the pore-forming agent, grinding, and sieving to obtain a nano-hybrid material; S3, preheating the nano-hybrid material, and after the preheating is completed, performing pyrolysis modification to obtain a nitrogen-doped template carbon nano-product, wherein the preheating temperature is 300-500° C., the preheating time is 3-6 hours, the pyrolysis temperature is 600-1000° C., and the pyrolysis time is 0.5-24 hours; S4, placing the nitrogen-doped template carbon nano-product in a template removal agent solution to react to obtain a nano-mixed solution, and centrifuging, washing, and drying the nano-mixed solution to obtain the lithium-ion battery porous carbon negative electrode material.

[0008] The porous carbon negative electrode material for lithium ion batteries prepared by the present invention has the advantages of high chemical stability, good conductivity, controllable pore size and fast lithium ion diffusion, and the pore size is basically concentrated in 20-40 nm; the assembled battery is used to test the electrochemical performance, the first charge and discharge efficiency can reach 85-95%, the reversible capacity is 300-450 mAh / g, and the capacity retention rate is greater than 88% after 500 cycles; at -20°C, the capacity is 85-99% when charged and discharged at a 0.2 C rate; at -40°C, the capacity is 77-99% when charged and discharged at a 0.2 C rate, and it is suitable for use as a high-performance lithium ion battery negative electrode material.

[0009] The present invention combines a hard template method with an element doping modification technique to prepare a nitrogen-doped template carbon nanoproduct, and then removes the template and washes to obtain the lithium ion battery porous carbon negative electrode material. The process is simple and the cost is low. The equipment used is all common equipment in the preparation of lithium ion battery negative electrode materials, which is conducive to large-scale production and promotion.

[0010] In some embodiments, the hard template material in S1 is selected from any one of anodized aluminum, silicon dioxide, and zeolite molecular sieve.

[0011] In the embodiment, anodized aluminum oxide, silicon dioxide, and zeolite molecular sieve are used as hard template materials, and the pore size, pore density, and pore depth can be precisely controlled to obtain a template with a specific and uniform pore structure, which can provide a highly ordered pore structure for the synthetic material. These hard template materials all have good mechanical stability and can maintain their structural integrity during the synthesis process. At the same time, these hard template materials are easy to remove, leaving materials with corresponding pore structures.

[0012] In some embodiments, the carbon precursor material in S1 is selected from any one of coal tar, phenolic resin, and rice husk.

[0013] Among them, coal tar contains more than 90% carbon, which is not easy to decompose at high temperature, which is conducive to the preparation of carbon materials with high carbon content, and can maintain structural stability during high temperature treatment. Similarly, phenolic resin has excellent heat resistance and chemical stability. The cross-linking density of phenolic resin can be adjusted by changing the raw material ratio and reaction conditions, thereby affecting the pore structure and performance of the final carbon material. The carbon material formed after the carbonization of phenolic resin usually has higher strength and hardness. Rice husk not only contains a large amount of carbon, has a wide source, and has a low cost for raw material acquisition, but also the rice husk itself has a porous structure, which can form a carbon material with rich pores after carbonization.

[0014] In the embodiment, these three materials are used as carbon precursors, and appropriate carbon precursor materials can be selected according to different application requirements to prepare carbon materials with specific properties.

[0015] In some embodiments, the mixing mass ratio of the hard template material and the carbon precursor material in S1 is 1:(1-2), the ball milling speed is 700-1000 rpm, and the ball milling time is 2-4 h.

[0016] In some embodiments, the mass ratio of the pore-forming agent to the template / carbon mixed material is 1:(0.3-3), and the pore-forming agent in S2 is selected from any one of urea, polyethylene glycol, and starch.

[0017] Urea can be decomposed at a relatively low temperature to generate gas (mainly ammonia and carbon dioxide), so pores can be formed during the sintering process of the material. Polyethylene glycol can melt and volatilize during the heating process without leaving any residue, so clean pores can be formed. Starch can form pores during the combustion process, and its combustion rate can be controlled by adjusting the type and content of starch. Starch itself has a porous structure and can be used as a template to guide the formation of pores.

[0018] In the embodiment, these three materials are used as pore formers, and the prepared pore size is controlled by controlling the mass ratio of the pore former and the template / carbon mixed material, thereby obtaining a lithium ion battery porous carbon negative electrode material with excellent pore structure.

[0019] In some embodiments, in S3, the preheating / pyrolysis needs to be carried out in an air-tight manner, specifically, heating in a vacuum environment or heating under the protection of an inert gas.

[0020] In some embodiments, in S4, the template removal agent is selected from any one of hydrofluoric acid, sodium hydroxide, and potassium hydroxide.

[0021] In some embodiments, in S4, the mass fraction of the de-templating agent in the de-templating agent solution is 25%-35%, and the mass ratio of the nitrogen-doped template carbon nanoproduct to the de-templating agent solution is 1:(1-3).

[0022] In the embodiment, a de-templating agent is used to dissolve the hard template material in the nitrogen-doped template carbon nanoproduct. By controlling the type and addition ratio of the de-templating agent, the dissolution of the nitrogen-doped template carbon nanoproduct by the de-templating agent is controlled to avoid affecting the performance of subsequent lithium-ion battery porous materials.

[0023] In some embodiments, in S4, the de-templated nanoproduct is washed with a deionized water / alcohol mixed solution, wherein the mass ratio of deionized water to alcohol solvent is 1:(1-3), and the alcohol solvent is selected from any one of anhydrous ethanol, methanol, and propanol.

[0024] In some embodiments, the centrifugal speed in S4 is 8000-10000 rpm, the centrifugal time is 10-30 min, the blast drying time is 8-24 h, and the blast drying temperature is 60-80 °C.

[0025] A second aspect of the present invention provides a high-performance porous carbon negative electrode material for lithium-ion batteries, characterized in that the high-performance porous carbon negative electrode material for lithium-ion batteries is prepared according to the method described in any one of the first aspects.

[0026] By implementing the above technical solution, the present invention has the following beneficial effects: The porous carbon negative electrode material for lithium ion batteries prepared by the present invention has the advantages of high chemical stability, good conductivity, controllable pore size and fast lithium ion diffusion, and the pore size is basically concentrated in 20-40 nm; the assembled battery is used to test the electrochemical performance, the first charge and discharge efficiency can reach 85-95%, the reversible capacity is 300-450 mAh / g, and the capacity retention rate is greater than 88% after 500 cycles; at -20°C, the capacity is 85-99% when charged and discharged at a 0.2 C rate; at -40°C, the capacity is 77-99% when charged and discharged at a 0.2 C rate, and it is suitable for use as a high-performance lithium ion battery negative electrode material.

[0027] The present invention combines a hard template method with an element doping modification technique to prepare a nitrogen-doped template carbon nanoproduct, and then removes the template and washes to obtain the lithium ion battery porous carbon negative electrode material. The process is simple and the cost is low. The equipment used is all common equipment in the preparation of lithium ion battery negative electrode materials, which is conducive to large-scale production and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the TEM of the porous carbon negative electrode material for lithium ion batteries prepared in Example 2; Figure 2 This is the SEM of the porous carbon negative electrode material for lithium ion batteries prepared in Example 2. DETAILED DESCRIPTION

[0029] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is described in detail below in conjunction with embodiments and drawings.

[0030] Example 1 A method for preparing a high-performance porous carbon negative electrode material for a lithium-ion battery comprises the following steps: (1) 4 g of silica hard template material and 4 g of coal tar pitch precursor were placed in a ball mill and ball milled at 750 rpm for 2 h at room temperature to obtain a template / carbon hybrid material.

[0031] (2) 3 g of template / carbon material and 1 g of urea were mixed and ground, and sieved with a mesh size of 300 to obtain a nano-hybrid material.

[0032] (3) The nano-hybrid material was preheated at 350 °C for 3 h in an Ar atmosphere and then heat treated at 800 °C for 2 h to obtain a nitrogen-doped template carbon nanoproduct after pyrolysis.

[0033] (4) The nitrogen-doped template carbon nanoproduct is fully reacted with the HF solution to wash away the SiO 2 Hard template material to obtain a nano-mixed solution.

[0034] (5) The obtained nano-mixed solution was centrifuged in a centrifuge at a speed of 9000 rpm for 15 min, and washed three times with 100 ml of a water / ethanol mixed solution to remove excess impurities. It was then dried in a 75 °C forced air oven for 12 h to obtain a high-performance lithium-ion battery porous carbon negative electrode material, which was used as a lithium-ion battery negative electrode material.

[0035] (6) The obtained porous carbon negative electrode material for lithium-ion batteries has a pore size of 28 nm. The electrochemical performance of the battery was tested by assembling a battery with acetylene black conductive agent. The first charge and discharge efficiency reached 90%, the reversible capacity was 360 mAh / g, and the capacity retention rate was 93% after 500 cycles. At -20 ℃ and 0.2 C discharge, the capacity was 92%; at -40 ℃ and 0.2 C discharge, the capacity was 83%.

[0036] Example 2 A method for preparing a high-performance porous carbon negative electrode material for a lithium-ion battery comprises the following steps: (1) 4 g of silica hard template material and 4 g of coal tar pitch precursor were placed in a ball mill and ball milled at 750 rpm for 2 h at room temperature to obtain a template / carbon hybrid material.

[0037] (2) 2 g of template / carbon material and 1 g of urea were mixed and ground, and sieved with a mesh size of 300 to obtain a nano-hybrid material.

[0038] (3) The nano-hybrid material was preheated at 350 °C for 3 h in an Ar atmosphere and then heat treated at 800 °C for 2 h to obtain a nitrogen-doped template carbon nanoproduct after pyrolysis.

[0039] (4) The nitrogen-doped template carbon nanoproduct is fully reacted with the HF solution to wash away the SiO 2 Hard template material to obtain a nano-mixed solution.

[0040] (5) The obtained nano-mixed solution was centrifuged in a centrifuge at a speed of 9000 rpm for 15 min, and washed three times with 100 ml of a water / ethanol mixed solution to remove excess impurities. It was then dried in a 75 °C forced air oven for 12 h to obtain a high-performance lithium-ion battery porous carbon negative electrode material, which was used as a lithium-ion battery negative electrode material.

[0041] (6) The obtained lithium-ion battery negative electrode material has a pore size concentrated at 36 nm. Using acetylene black conductive agent, the battery was assembled to test the electrochemical performance. The first charge and discharge efficiency reached 93%, the reversible capacity was 423 mAh / g, and the capacity retention rate was 95% after 500 cycles. At -20 ℃ and 0.2 C discharge, the capacity was 95.6%; at -40 ℃ and 0.2 C discharge, the capacity was 88%.

[0042] Example 3 A method for preparing a high-performance porous carbon negative electrode material for a lithium-ion battery comprises the following steps: (1) 4 g of silica hard template material and 4 g of coal tar pitch precursor were placed in a ball mill and ball milled at 750 rpm for 2 h at room temperature to obtain a template / carbon hybrid material.

[0043] (2) 1 g of template / carbon material and 1 g of urea were mixed and ground, and sieved with a mesh size of 300 to obtain a nano-hybrid material.

[0044] (3) The nano-hybrid material was preheated at 350 °C for 3 h in an Ar atmosphere and then heat treated at 800 °C for 2 h to obtain a nitrogen-doped template carbon nanoproduct after pyrolysis.

[0045] (4) The nitrogen-doped template carbon nanoproduct is fully reacted with the HF solution to wash away the SiO 2 Hard template material to obtain a nano-mixed solution.

[0046] (5) The obtained nano-mixed solution was centrifuged in a centrifuge at a speed of 9000 rpm for 15 min, and washed three times with 100 ml of a water / ethanol mixed solution to remove excess impurities. It was then dried in a 75 °C forced air oven for 12 h to obtain a high-performance lithium-ion battery porous carbon negative electrode material, which was used as a lithium-ion battery negative electrode material.

[0047] (6) The obtained porous carbon negative electrode material for lithium-ion batteries has a pore size of 33 nm. The electrochemical performance of the battery was tested by assembling a battery with acetylene black conductive agent. The first charge and discharge efficiency reached 91%, the reversible capacity was 392 mAh / g, and the capacity retention rate was 93.1% after 500 cycles. At -20 ℃ and 0.2 C discharge, the capacity was 91.8%; at -40 ℃ and 0.2 C discharge, the capacity was 82%.

[0048] Example 4 A method for preparing a high-performance porous carbon negative electrode material for a lithium-ion battery comprises the following steps: (1) 4 g of silica hard template material and 4 g of coal tar pitch precursor were placed in a ball mill and ball milled at 750 rpm for 2 h at room temperature to obtain a template / carbon hybrid material.

[0049] (2) 1 g of template / carbon material and 2 g of urea were mixed and ground, and sieved with a mesh size of 300 to obtain a nano-hybrid material.

[0050] (3) The nano-hybrid material was preheated at 350 °C for 3 h in an Ar atmosphere and then heat treated at 800 °C for 2 h to obtain a nitrogen-doped template carbon nanoproduct after pyrolysis.

[0051] (4) The nitrogen-doped template carbon nanoproduct is fully reacted with the HF solution to wash away the SiO 2 Hard template material to obtain a nano-mixed solution.

[0052] (5) The obtained nano-mixed solution was centrifuged in a centrifuge at a speed of 9000 rpm for 15 min, and washed three times with 100 ml of a water / ethanol mixed solution to remove excess impurities. It was then dried in a 75 °C forced air oven for 12 h to obtain a high-performance lithium-ion battery porous carbon negative electrode material, which was used as a lithium-ion battery negative electrode material.

[0053] (6) The obtained porous carbon negative electrode material for lithium-ion batteries has a pore size of 22 nm. The electrochemical performance of the battery was tested by assembling it with acetylene black conductive agent. The first charge and discharge efficiency reached 88%, the reversible capacity was 336 mAh / g, and the capacity retention rate was 90% after 500 cycles. At -20 ℃ and 0.2 C discharge, the capacity was 88%; at -40 ℃ and 0.2 C discharge, the capacity was 80%.

[0054] Example 5 A method for preparing a high-performance porous carbon negative electrode material for a lithium-ion battery comprises the following steps: (1) 4 g of silica hard template material and 4 g of coal tar pitch precursor were placed in a ball mill and ball milled at 750 rpm for 2 h at room temperature to obtain a template / carbon hybrid material.

[0055] (2) 1 g of template / carbon material and 3 g of urea were mixed and ground, and sieved with a mesh size of 300 to obtain a nano-hybrid material.

[0056] (3) The nano-hybrid material was preheated at 350 °C for 3 h in an Ar atmosphere and then heat treated at 800 °C for 2 h to obtain a nitrogen-doped template carbon nanoproduct after pyrolysis.

[0057] (4) The nitrogen-doped template carbon nanoproduct is fully reacted with the HF solution to wash away the SiO 2 Hard template material to obtain a nano-mixed solution.

[0058] (5) The obtained nano-mixed solution was centrifuged in a centrifuge at a speed of 9000 rpm for 15 min, and washed three times with 100 ml of a water / ethanol mixed solution to remove excess impurities. It was then dried in a 75 °C forced air oven for 12 h to obtain a high-performance lithium-ion battery porous carbon negative electrode material, which was used as a lithium-ion battery negative electrode material.

[0059] (6) The obtained porous carbon negative electrode material for lithium-ion batteries has a pore size of 17 nm. The electrochemical performance of the battery was tested by assembling a battery with acetylene black conductive agent. The first charge and discharge efficiency reached 86%, the reversible capacity was 318 mAh / g, and the capacity retention rate was 88% after 500 cycles. At -20 ℃ and 0.2 C discharge, the capacity was 86%; at -40 ℃ and 0.2 C discharge, the capacity was 78%.

[0060] Comparative Example 1 A method for preparing a high-performance porous carbon negative electrode material for a lithium-ion battery comprises the following steps: (1) 4 g of coal tar pitch precursor was placed in a ball mill and ball milled at 750 rpm for 2 h at room temperature to obtain a uniform coal tar pitch material.

[0061] (2) 2 g of coal tar pitch material and 1 g of urea were mixed and ground, and sieved with a mesh size of 300 to obtain a nano-hybrid material.

[0062] (3) The nano-hybrid material was preheated at 350 °C for 3 h in an Ar atmosphere and then heat treated at 800 °C for 2 h to obtain a nitrogen-doped nanocarbon product after pyrolysis.

[0063] (4) The nitrogen-doped nanocarbon product was washed three times with 100 ml of a water / ethanol mixed solution to remove excess impurities, and then dried in a 75 °C forced air oven for 12 h to obtain a high-performance lithium-ion battery porous carbon negative electrode material, which was used as a lithium-ion battery negative electrode material.

[0064] (5) The obtained porous carbon negative electrode material for lithium-ion batteries has a pore size of 18 nm. The electrochemical performance of the battery was tested by assembling a battery with acetylene black conductive agent. The first charge and discharge efficiency reached 78%, the reversible capacity was 286 mAh / g, and the capacity retention rate was 73% after 500 cycles. At -20 ℃ and 0.2 C discharge, the capacity was 64%; at -40 ℃ and 0.2 C discharge, the capacity was 52%.

[0065] Comparative Example 2 A method for preparing a high-performance porous carbon negative electrode material for a lithium-ion battery comprises the following steps: (1) 4 g of silica hard template material and 4 g of coal tar pitch precursor were placed in a ball mill and ball milled at 750 rpm for 2 h at room temperature to obtain a template / carbon hybrid material.

[0066] (2) Grind 1 g of template / carbon material and sieve it with a mesh size of 300 to obtain a nano-hybrid material.

[0067] (3) The nano-hybrid material was preheated at 350 °C for 3 h in an Ar atmosphere and then heat treated at 800 °C for 2 h to obtain a nitrogen-doped template carbon nanoproduct after pyrolysis.

[0068] (4) The nitrogen-doped template carbon nanoproduct is fully reacted with the HF solution to wash away the SiO 2 Hard template material to obtain a nano-mixed solution.

[0069] (5) The obtained nano-mixed solution was centrifuged in a centrifuge at a speed of 9000 rpm for 15 min, and washed three times with 100 ml of a water / ethanol mixed solution to remove excess impurities. It was then dried in a 75 °C forced air oven for 12 h to obtain a high-performance lithium-ion battery porous carbon negative electrode material, which was used as a lithium-ion battery negative electrode material.

[0070] (6) The obtained porous carbon negative electrode material for lithium-ion batteries has a pore size of 9 nm. The electrochemical performance of the battery was tested by assembling a battery with acetylene black conductive agent. The first charge and discharge efficiency reached 85%, the reversible capacity was 310 mAh / g, and the capacity retention rate was 80% after 500 cycles. At -20 ℃ and 0.2 C discharge, the capacity was 76%; at -40 ℃ and 0.2 C discharge, the capacity was 68%.

[0071] The above-mentioned embodiments are preferred examples of the present invention and are not intended to limit the protection scope of the present invention.

Claims

1. A method for preparing a high-performance porous carbon negative electrode material for lithium-ion batteries, characterized in that: The following steps are involved: S1, ball-milling a hard template material and a carbon precursor material to obtain a template / carbon mixed material; S2, mixing the template / carbon hybrid material with the pore-forming agent, grinding, and sieving to obtain a nano-hybrid material; S3, preheating the nano-hybrid material, and after the preheating is completed, performing pyrolysis modification to obtain a nitrogen-doped template carbon nano-product, wherein the preheating temperature is 300-500° C., the preheating time is 3-6 hours, the pyrolysis temperature is 600-1000° C., and the pyrolysis time is 0.5-24 hours; S4, placing the nitrogen-doped template carbon nano-product in a template removal agent solution to react to obtain a nano-mixed solution, and centrifuging, washing, and drying the nano-mixed solution to obtain the lithium-ion battery porous carbon negative electrode material.

2. The preparation method according to claim 1, characterized in that: The hard template material in S1 is selected from any one of anodized aluminum, silicon dioxide, and zeolite molecular sieve.

3. The method according to claim 2, characterized in that The carbon precursor material in S1 is selected from any one of coal tar, phenolic resin and rice husk.

4. The method according to claim 3, characterized in that The mixing mass ratio of the hard template material and the carbon precursor material in the S1 is 1:(1~2), the ball milling speed is 700~1000 rpm, and the ball milling time is 2~4 h.

5. The method according to claim 1, characterized in that The mass ratio of the pore-forming agent to the template / carbon mixed material is 1:(0.3-3), and the pore-forming agent in S2 is selected from any one of urea, polyethylene glycol, and starch.

6. The method according to claim 1, characterized in that In S4, the template removal agent is selected from any one of hydrofluoric acid, sodium hydroxide and potassium hydroxide.

7. The method according to claim 6, characterized in that In the S4, the mass fraction of the de-template agent in the de-template agent solution is 25%-35%, and the mass ratio of the nitrogen-doped template carbon nanoproduct to the de-template agent solution is 1:(1-3).

8. The method according to claim 7, characterized in that In S4, the nano-mixed solution is washed with a deionized water / alcohol mixed solution, in which the mass ratio of deionized water to alcohol solvent is 1:(1-3), and the alcohol solvent is selected from any one of anhydrous ethanol, methanol, and propanol.

9. The method according to claim 1, characterized in that: In the S4, the centrifugal speed is 8000-10000 rpm, the centrifugal time is 10-30 min, the blast drying time is 8-24 h, and the blast drying temperature is 60-80 °C.

10. A high-performance porous carbon negative electrode material for lithium-ion batteries, characterized in that: The high-performance lithium-ion battery porous carbon negative electrode material is prepared according to the method according to any one of claims 1 to 9.

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