Customized microporous hard carbon negative electrode material and preparation method and application thereof

Abstract

The application discloses a kind of customized microporous hard carbon negative material and its preparation method and application, belong to electrochemical energy storage material technical field.The preparation method includes the following steps: S01, deposition substrate is laid in reactor, then reactor is placed in deposition device, and reaction agent is introduced to carry out reaction, after reaction, cooling to room temperature, and initial sample is obtained;S02, the initial sample obtained in step S01 is taken out, and solvent is added to initial sample for soaking;After soaking is completed, suction filtration, drying, heating, and after cooling, customized microporous hard carbon negative material is obtained.The specific surface area of the customized microporous hard carbon negative material of the application is large, has rich open micropore below 1nm, is conducive to improving the initial coulomb efficiency of sodium ion battery;At the same time, micropore adsorbs more capacity of sodium ion, and electrochemical performance is high and rate performance is excellent;The application overcomes the problem of low initial coulomb efficiency with high specific surface area in the past, and has high cycle stability.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical energy storage materials, and in particular to a customized microporous hard carbon negative electrode material and a preparation method and application thereof. Background Art

[0002] In order to vigorously develop sustainable energy, large-scale energy storage technology has received considerable attention. Compared with this, sodium-ion batteries are expected to become the most attractive alternative.

[0003] First, sodium and lithium belong to the same main group and share similar chemical properties. However, the abundance of sodium in the Earth's crust (2.74%) is far higher than that of lithium (0.0065%), making sodium batteries more cost-effective for commercial development. Regarding safety, lithium-ion batteries are prone to dendrite formation at high current densities, potentially piercing the separator and causing a short circuit. In comparison, sodium batteries have a lower probability of dendrite formation and are therefore safer.

[0004] Currently, sodium-ion battery anode materials can be categorized into the following categories: alloys, conversion materials, titanium-based materials, and carbon-based materials. Hard carbon materials offer excellent conductivity, no significant volume expansion, excellent cycling stability, and readily available precursors. However, these materials generally suffer from poor rate performance and low initial coulombic efficiency, resulting in a greater loss of irreversible capacity.

[0005] Structural adjustments in hard carbon materials (introducing micropores) can effectively address the issues of low battery rate and initial coulombic efficiency. Considering that increasing the specific surface area of ​​a material exacerbates irreversible capacity, many researchers have focused on creating closed micropores to improve the initial coulombic efficiency. In fact, creating microporous materials with large specific surface areas in an open-pore form can also lead to improved initial coulombic efficiency and increased rate performance. Summary of the Invention

[0006] Based on this, the embodiment of the present invention provides a customized microporous hard carbon negative electrode material and its preparation method and application. It aims to solve the problems of poor rate performance, low first coulomb efficiency and large irreversible capacity loss of existing sodium ion battery negative electrode hard carbon materials. The preparation method of the present invention obtains microporous hard carbon with high specific surface area, rich micropores and excellent electrochemical performance by high-temperature evaporation of hard carbon precursor materials containing heteroatoms, breaking the previous view that high specific surface area leads to low first coulomb efficiency, and has high first coulomb efficiency and rate capability, as well as good cycle stability; and in terms of process, it can be customized to produce microporous hard carbon materials with specific specific surface area and pore size by changing the elements and content according to different needs, and is expected to be applied in more fields.

[0007] The technical solution of the present invention is achieved as follows:

[0008] A method for preparing a customized microporous hard carbon negative electrode material comprises the following steps:

[0009] S01, laying the deposition substrate flat in the reactor, then placing the reactor in the deposition device, introducing the reactants to react, and cooling to room temperature after the reaction to obtain an initial sample;

[0010] S02. The initial sample obtained in step S01 is taken out, and a solvent is added to the initial sample for soaking; after the soaking is completed, the sample is filtered, dried, heated, and cooled to obtain a customized microporous hard carbon negative electrode material.

[0011] As a preferred embodiment, in step S01,

[0012] The deposition substrate is freeze-dried sodium chloride powder.

[0013] The amount of the deposition substrate is 10 g to 15 g.

[0014] The reactant is at least one of carbon disulfide, phosphorus trichloride, selenium chloride or hydroiodic acid.

[0015] When the reactant is carbon disulfide, there is no need to add a gas containing carbon elements;

[0016] When the reactant is at least one of phosphorus trichloride, selenium chloride or hydroiodic acid, a gas containing carbon elements needs to be added.

[0017] The dosage of the reactant is 10-15 ml.

[0018] The carbon-containing gas is preferably a hydrogen mixed gas with a methane volume content of 30%, and a flow rate of 50 sccm to 150 sccm.

[0019] The reactor is a corundum ark; the deposition device is a plasma enhanced chemical vapor deposition device.

[0020] The initial temperature of the reaction is 20°C to 50°C, the reaction temperature is 20°C to 500°C, the heating rate is 10°C / min; and the reaction time is 30 min to 60 min.

[0021] The cooling method is to remove the heating component of the deposition device after the reaction is completed, and allow the sample to cool down quickly to room temperature.

[0022] As a preferred embodiment, in step S02,

[0023] The solvent is deionized water. The amount of the solvent used is 50ml to 100ml. The deposited substrate can be removed by soaking in the solvent.

[0024] The soaking time is 8 to 12 hours. The soaking is preferably carried out in a beaker.

[0025] The number of times of the filtration is 1 to 2 times.

[0026] The drying temperature is 50° C. to 100° C., and the drying time is 10 hours to 12 hours. Further preferably, the drying is carried out in an electric heated forced air drying oven.

[0027] The heating device for heating is preferably a tube furnace.

[0028] The heating temperature is 900° C. to 1000° C., the heating time is 30 min to 90 min, and the heating atmosphere is nitrogen; the heteroatoms of the initial sample are evaporated by heating.

[0029] A customized microporous hard carbon negative electrode material is obtained by the above preparation method.

[0030] The above-mentioned customized microporous hard carbon negative electrode material is used in sodium ion batteries.

[0031] The custom microporous hard carbon anode material prepared in this invention has a pore size of less than 1 nm. Its rich microporous structure effectively prevents a large number of solvent molecules from entering the material during the charge and discharge process, thereby reducing irreversible capacity loss caused by solvent molecule decomposition, limiting the formation of solid electrolyte surfaces within the pores, and improving the initial coulombic efficiency. Furthermore, sodium ions can migrate freely within the pores, and the active sites on the pore surface remain stable over long cycles due to the lack of interference from solvent molecules, which helps improve the material's rate capability and long-term cycling capability.

[0032] Furthermore, plasma chemical vapor deposition (PCVD) allows for the rapid and cost-effective production of hard carbon precursors containing heteroatoms (S, P, Se, and I), without large-scale agglomeration of the heteroatoms. Depending on the heteroatom elements and their content in the precursor, simply heating the hard carbon precursor at high temperatures can directly yield large-area microporous materials suitable for sodium-ion battery anodes. This is because the heteroatoms evaporate at high temperatures, leaving behind micropores similar in size to the molecules. The entire process is efficient and simple, amenable to commercial large-scale production.

[0033] Furthermore, due to differences in heteroatom elements and variations in heteroatom content in the precursor under different experimental conditions, the specific surface area and pore diameter of the resulting hard carbon materials vary significantly. Therefore, custom hard carbon can be created based on specific needs. Specifically, the heteroatom elements and their content can be adjusted to create porous hard carbon materials with specific surface areas and pore diameters within a specific range. The entire process is efficient and simple, and can be commercialized for large-scale production.

[0034] Compared with the existing technology, this application has the following technical effects:

[0035] The customized microporous hard carbon negative electrode material obtained by plasma vapor deposition and high-temperature heating in the present application has a high specific surface area and rich microporous structure. A large number of microporous structures are conducive to the desolvation of solvated sodium ions during the cycle, which improves the first coulombic efficiency. At the same time, the defects and active sites in the micropores promote the transmission of sodium ions and enhance the rate performance. The sheet structures with high specific surface area are stacked on each other, which reduces the volume expansion of the material and forms a sodium ion channel with high conductivity. In addition, in terms of process, it is only necessary to change the experimental conditions to customize hard carbon with different specific surface areas and pore sizes. The customization idea is simple and efficient. The preparation method of the present application is simple, low cost, and can be applied to large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 BET characterization diagram of the customized microporous hard carbon negative electrode material for sodium ion batteries prepared in Example 1 of the present invention;

[0038] Figure 2 XRD characterization diagram of the customized microporous hard carbon negative electrode material for sodium ion batteries prepared in Example 1 of the present invention;

[0039] Figure 3 This is an SEM characterization image of the customized microporous hard carbon negative electrode material for sodium ion batteries prepared in Example 1 of the present invention;

[0040] Figure 4 TEM characterization of the customized microporous hard carbon negative electrode material for sodium ion batteries prepared in Example 1 of the present invention;

[0041] Figure 5 A half-cell rate performance test diagram of the customized microporous hard carbon negative electrode material for sodium ion batteries prepared in Example 1 of the present invention;

[0042] Figure 6 A graph showing the cycling performance of a half-cell assembled with the sodium ion customized microporous hard carbon anode material prepared in Example 1 of the present invention at a current density of 50 A g-1;

[0043] Figure 7 BET characterization diagram of the customized microporous hard carbon negative electrode material for sodium ion batteries prepared in Example 2 of the present invention;

[0044] Figure 8 XRD characterization diagram of the customized microporous hard carbon negative electrode material for sodium ion batteries prepared in Example 2 of the present invention;

[0045] Figure 9 A graph showing the cycling performance of a half-cell assembled with the sodium ion customized microporous hard carbon anode material prepared in Example 2 of the present invention at a current density of 500 mA g-1;

[0046] Figure 10 BET characterization diagram of the customized microporous hard carbon negative electrode material for sodium ion batteries prepared in Example 3 of the present invention;

[0047] Figure 11 BET characterization diagram of the customized microporous hard carbon negative electrode material for sodium ion batteries prepared in Example 4 of the present invention.

[0048] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0050] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0051] Currently, most hard carbon anode materials for sodium-ion batteries have low specific surface areas. Conventional wisdom holds that a large specific surface area leads to significant irreversible capacity loss due to the formation of more solid electrolyte interphase (SEI) on the surface. However, customized microporous materials defy this conventional wisdom by possessing large intra-micropore specific surface areas and abundant ultra-micropores. These micropores prevent a large number of free solvent molecules from entering the material, promoting desolvation and improving initial coulombic efficiency. Furthermore, the micropores also adsorb a large number of sodium ions, providing high adsorption capacity during cycling and enhancing electrochemical performance. Example 1

[0052] A method for preparing a customized microporous hard carbon negative electrode material (carbon disulfide reactant) comprises the following steps:

[0053] S01. 15 g of freeze-dried sodium chloride powder (deposition substrate) was spread flatly in a corundum ark reactor, and then the corundum ark reactor was placed in a plasma-enhanced chemical vapor deposition device. 15 ml of carbon disulfide was introduced for reaction. The initial temperature of the reaction was 20° C., the reaction temperature was 40° C., the heating rate was 10° C. / min, and the reaction time was 60 min. After the reaction was completed, the heating component of the deposition device was removed, and the sample was quickly cooled to room temperature to obtain an initial sample.

[0054] S02. Take the initial sample in step S01 into a beaker, and add 100 ml of deionized water to the initial sample for soaking for 8 hours; after soaking, filter twice, dry it in an electric blast drying oven at 50°C for 10 hours, and then heat it in a tubular furnace. The atmosphere of the tubular furnace is nitrogen, the heating time is 60 minutes, the heating temperature is 1000°C, and after cooling, a customized microporous hard carbon negative electrode material is obtained.

[0055] The customized microporous hard carbon negative electrode material prepared in Example 1 was used as the active material; the active material, conductive carbon black, and polyacrylic acid were weighed in a mortar according to the mass ratio of active material: conductive agent: binder = 6:3:1, ground and mixed evenly, and NMP solution was added and mixed evenly to a paste slurry, which was then applied to a conductive copper foil. The copper foil containing the active material was dried at 80°C for 12 hours as the negative electrode, and the sodium sheet was used as the counter electrode; sodium hexafluorophosphate NaPF6 was used as the solute, and ethylene glycol dimethyl ether DME was used as the solvent, and the concentration was prepared to be 1 mol.L -1 The solution was used as the electrolyte; finally, a 2032 button-type sodium ion half-cell was assembled and charge and discharge tests were performed, with the test voltage window being 0.01 V-2.7 V.

[0056] The BET characterization diagram of the customized microporous hard carbon negative electrode material provided in Example 1 is as follows Figure 1 shown; from Figure 1 It can be observed that the microporous hard carbon material has micropores of 0.64 nm and a large specific surface area of ​​1252 m 2 g -1 .

[0057] The XRD characterization diagram of the customized microporous hard carbon negative electrode material prepared in Example 1 is as follows Figure 2 As shown, from Figure 2 It can be found that the structure of the customized microporous hard carbon negative electrode material prepared in this embodiment is an amorphous carbon peak package.

[0058] The SEM characterization of the customized microporous hard carbon negative electrode material prepared in Example 1 is shown in FIG. Figure 3 As shown, from Figure 3 It can be seen that the microporous hard carbon negative electrode material prepared in this embodiment is a sheet-like porous carbon.

[0059] The TEM characterization of the customized microporous hard carbon negative electrode material prepared in Example 1 is shown in FIG. Figure 4 As shown, from Figure 4 It can be seen that the microporous hard carbon negative electrode material prepared in this embodiment is a porous carbon material with a uniformly distributed carbon layer.

[0060] The half-cell rate performance test diagram of the customized microporous hard carbon negative electrode material prepared in Example 1 is shown in FIG. Figure 5 As shown, from Figure 5 It can be seen that the current density is 0.2A·g -1 ~30A·g -1 The range of the step increases, the electrode is 0.2, 0.5, 1, 2, 5, 10, 15, 20, 30A g -1 The average capacities were 502, 459, 427, 408, 392, 376, 362, 357, and 345 mAh·g, respectively. -1 When the current density returns to 0.2 A g -1 When the capacity is still up to 500Ah·g -1 , showing good rate performance.

[0061] The customized microporous hard carbon negative electrode material prepared in Example 1 is applied to sodium ion batteries. The half-cell assembled with the microporous hard carbon negative electrode material for sodium ion batteries prepared in Example 1 is subjected to a load of 50 A·g -1 The cycle performance test at the current density is shown in the figure Figure 6 As shown, from Figure 6 It can be seen that at 50 A·g -1 After 6000 cycles at a current density of 1.5 mAh g -1 capacity and exhibits good cycling stability.

[0062] Example 2

[0063] A method for preparing a customized microporous hard carbon negative electrode material (phosphorus chloride reactant) comprises the following steps:

[0064] S01. 15 g of freeze-dried sodium chloride powder (deposition substrate) was spread flatly in a corundum ark reactor, and then the corundum ark reactor was placed in a plasma-enhanced chemical vapor deposition device. Phosphorus trichloride and carbon-containing gas were introduced for reaction. The amount of phosphorus trichloride was 15 ml. The initial temperature of the reaction was 20°C, the reaction temperature was 500°C, the heating rate was 10°C / min, and the reaction time was 60 min. After the reaction was completed, the heating component of the deposition device was removed, and the sample was quickly cooled to room temperature to obtain an initial sample.

[0065] The carbon-containing gas is a hydrogen mixed gas with a flow rate of 150 sccm and a methane volume content of 30%;

[0066] S02. Take the initial sample in step S01 into a beaker, and add 100 ml of deionized water to the initial sample for soaking for 8 hours; after soaking, filter twice, dry it in an electric blast drying oven at 50°C for 10 hours, and then heat it in a tubular furnace. The atmosphere of the tubular furnace is nitrogen, the heating time is 60 minutes, the heating temperature is 1000°C, and after cooling, a customized microporous hard carbon negative electrode material is obtained.

[0067] The customized material prepared in Example 2 was used as the active material. The active material, conductive carbon black, and polyacrylic acid were weighed in a mortar according to the mass ratio of active material: conductive agent: binder = 6:3:1, and ground and mixed evenly. NMP solution was added and mixed evenly to a paste slurry, which was then applied to a conductive copper foil. The copper foil containing the active material was dried at 80°C for 12 hours as the negative electrode, and the sodium sheet was used as the counter electrode. Sodium hexafluorophosphate NaPF6 was used as the solute, and ethylene glycol dimethyl ether DME was used as the solvent. The concentration was prepared to be 1 mol·L -1 The solution was used as the electrolyte; finally, a 2032 button-type sodium ion half-cell was assembled and charge and discharge tests were performed, with the test voltage window being 0.01 V-2.7 V.

[0068] The BET characterization diagram of the customized microporous hard carbon negative electrode material provided in Example 2 is as follows Figure 7 shown; from Figure 7 It can be observed that the customized microporous hard carbon material has micropores of 0.73 nm and a large specific surface area of ​​672 m 2 ·g −1 ;

[0069] The XRD characterization of the customized microporous hard carbon negative electrode material for sodium ion batteries prepared in Example 2 of the present invention is shown in FIG. Figure 8 As shown, from Figure 8 It can be found that the structure of the material is an amorphous carbon peak package;

[0070] The half-cell assembled with the sodium ion customized microporous hard carbon negative electrode material prepared in Example 2 of the present invention was -1 The cycle performance test at the current density is shown in the figure Figure 9 shown.

[0071] Example 3

[0072] A method for preparing a customized microporous hard carbon negative electrode material (selenium chloride reactant) comprises the following steps:

[0073] S01. 15 g of freeze-dried sodium chloride powder (deposition substrate) was spread flatly in a corundum ark reactor, and then the corundum ark reactor was placed in a plasma-enhanced chemical vapor deposition device. Selenium chloride and carbon-containing gas were introduced for reaction. The amount of selenium chloride used was 15 ml. The initial temperature of the reaction was 20°C, the reaction temperature was 500°C, the heating rate was 10°C / min, and the reaction time was 60 min. After the reaction was completed, the heating component of the deposition device was removed, and the sample was quickly cooled to room temperature to obtain an initial sample.

[0074] The carbon-containing gas is a hydrogen mixed gas with a flow rate of 150 sccm and a methane volume content of 30%;

[0075] S02. Take the initial sample in step S01 into a beaker, add 50 ml of deionized water to the initial sample and soak it for 8 hours; after soaking, filter it twice, dry it in an electric blast drying oven at 50°C for 10 hours, and then heat it in a tubular furnace. The atmosphere of the tubular furnace is nitrogen, the heating time is 60 minutes, the heating temperature is 1000°C, and after cooling, a customized microporous hard carbon negative electrode material is obtained.

[0076] The BET characterization diagram of the customized microporous hard carbon negative electrode material provided in Example 3 is as follows Figure 10 shown; from Figure 10 It can be observed that the customized microporous hard carbon material has micropores of 0.53 nm and a large specific surface area of ​​711 m 2 ·g −1 .

[0077] Example 4

[0078] A method for preparing a customized microporous hard carbon negative electrode material (hydriodic acid reactant) comprises the following steps:

[0079] S01. 15 g of freeze-dried sodium chloride powder (deposition substrate) was spread flatly in a corundum ark reactor, and then the corundum ark reactor was placed in a plasma-enhanced chemical vapor deposition device. Hydroiodic acid and carbon-containing gas were introduced for reaction. The amount of hydroiodic acid used was 15 ml. The initial temperature of the reaction was 20°C, the reaction temperature was 200°C, the heating rate was 10°C / min, and the reaction time was 60 min. After the reaction was completed, the heating component of the deposition device was removed, and the sample was quickly cooled to room temperature to obtain an initial sample.

[0080] The carbon-containing gas is a hydrogen mixed gas with a flow rate of 150 sccm and a methane volume content of 30%;

[0081] S02. Take the initial sample in step S01 into a beaker, add 50 ml of deionized water to the initial sample and soak it for 8 hours; after soaking, filter it twice, dry it in an electric blast drying oven at 50°C for 10 hours, and then heat it in a tubular furnace. The atmosphere of the tubular furnace is nitrogen, the heating time is 60 minutes, the heating temperature is 1000°C, and after cooling, a customized microporous hard carbon negative electrode material is obtained.

[0082] The BET characterization diagram of the customized microporous hard carbon negative electrode material provided in Example 4 is as follows Figure 11 shown; from Figure 11 It can be observed that the customized microporous hard carbon anode material has micropores of 0.67 nm and a small specific surface area of ​​297 m 2 ·g −1 .

[0083] Reference for this comparative example: Zhen, Yichao, et al. "Breaking the limitation of sodium-ion storage for nanostructured carbon anode by engineering desolvation barrier with neat electrolytes." Nano Energy 74 (2020): 104895. A method for preparing a large specific surface area mesoporous sodium ion battery storage material, the specific steps are as follows:

[0084] (1) Weigh 45 g of lithium chloride and 55 g of potassium chloride into a beaker and mix them evenly to form a metal chloride salt.

[0085] (2) Weigh 1 g of glucose and 2 g of sodium thiosulfate powder and add them to the metal chloride salt to form a mixture.

[0086] (3) The mixture was placed in a crucible, heated to 350°C at 5°C per minute under an argon atmosphere and kept at this temperature for 2 hours, then heated to 600°C and kept at this temperature for 5 hours, and finally cooled to room temperature to obtain sample A.

[0087] (4) Sample A was crushed into powder, washed with sufficient deionized water and dilute hydrochloric acid, and finally dried at 60°C for 24 hours to obtain a mesoporous material with a large specific surface area.

[0088] Compare the method of the present invention with Comparative Example 1: The synthesis steps of Comparative Example 1 are cumbersome, and it is necessary to first undergo a molten salt reaction and then anneal for a long time to obtain a carbon material with a large specific surface area. Moreover, the molten salt method used in Comparative Example 1 requires the consumption of a large amount of metal chloride, which is costly and limits the application of this method to a certain extent. The plasma chemical vapor deposition reaction time used in the method of the present invention is shorter, requires fewer consumables, is lower in cost, is safe and convenient, can be used to quickly prepare customized microporous hard carbon, and has higher universality.

[0089] Compared with the existing technology, this application has the following technical effects:

[0090] The customized microporous hard carbon negative electrode material obtained by plasma vapor deposition and high-temperature heating in the present application has a high specific surface area and rich microporous structure. A large number of microporous structures are conducive to the desolvation of solvated sodium ions during the cycle, which improves the first coulombic efficiency. At the same time, the defects and active sites in the micropores promote the transmission of sodium ions and enhance the rate performance. The sheet structures with high specific surface area are stacked on each other, which reduces the volume expansion of the material and forms a sodium ion channel with high conductivity. In addition, in terms of process, it is only necessary to change the experimental conditions to customize hard carbon with different specific surface areas and pore sizes. The customization idea is simple and efficient. The preparation method of the present application is simple, low cost, and can be applied to large-scale production.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a customized microporous hard carbon negative electrode material, characterized by: The steps include: S01, laying the deposition substrate flat in the reactor, then placing the reactor in the deposition device, introducing the reactants to react, and cooling to room temperature after the reaction to obtain an initial sample; S02, taking out the initial sample obtained in step S01, adding a solvent to the initial sample for soaking; after the soaking is completed, filtering, drying, heating, and cooling to obtain a customized microporous hard carbon negative electrode material; In step S01, the deposition substrate is freeze-dried sodium chloride powder; The amount of the deposition substrate is 10g to 15g; The reactant is at least one of carbon disulfide, phosphorus trichloride, selenium chloride or hydroiodic acid; When the reactant is carbon disulfide, there is no need to add a gas containing carbon elements; When the reactant is at least one of phosphorus trichloride, selenium chloride or hydroiodic acid, a carbon-containing gas needs to be added; The dosage of the reactant is 10-15 ml; The deposition device is a plasma enhanced chemical vapor deposition device; The reaction temperature of the reaction is 20°C to 500°C, and the reaction time is 30 min to 60 min; In step S02, the solvent is deionized water; The heating temperature is 900° C. to 1000° C., the heating time is 30 min to 90 min, and the heating atmosphere is nitrogen.

2. The method for preparing a customized microporous hard carbon negative electrode material according to claim 1, characterized in that: The carbon-containing gas is a mixed gas of hydrogen with a methane volume content of 30%, and the flow rate is 50 sccm to 150 sccm.

3. The method for preparing a customized microporous hard carbon negative electrode material according to claim 1, characterized in that: In step S01, the reactor is a corundum ark.

4. The method for preparing a customized microporous hard carbon negative electrode material according to claim 1, characterized in that: In step S01, the initial temperature of the reaction is 20°C to 50°C, and the heating rate is 10°C / min; The cooling method is to remove the heating component of the deposition device after the reaction is completed, and allow the sample to cool down quickly to room temperature.

5. The method for preparing a customized microporous hard carbon negative electrode material according to claim 1, characterized in that: In step S02, the amount of the solvent is 50ml to 100ml; The soaking time is 8 hours to 12 hours.

6. The method for preparing a customized microporous hard carbon negative electrode material according to claim 1, characterized in that: In step S02, the filtration is performed 1 to 2 times; The drying temperature is 50°C to 100°C, and the drying time is 10h to 12h; The heating device for heating is a tubular furnace.

7. A customized microporous hard carbon negative electrode material obtained by the preparation method described in any one of claims 1 to 6.

8. Use of the customized microporous hard carbon negative electrode material according to claim 7 in sodium ion batteries.

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