Preparation method and application of bamboo-based hard carbon material based on pore structure regulation and control

Abstract

The invention discloses a preparation method and application of a bamboo-based hard carbon material based on pore structure regulation and control, and belongs to the technical field of new energy materials. The preparation method comprises the following steps: ball-milling and uniformly mixing coarse bamboo powder and a modifying reagent according to different mass ratios; heating treatment is carried out to promote advanced pyrolysis of the bamboo powder, in-situ depolymerization and reassembly of three element molecules are achieved, and a modified intermediate is obtained; carrying out acid washing and water washing on the modified intermediate, and drying to obtain neutral bamboo-based pyrolytic carbon; and putting the neutral bamboo-based pyrolytic carbon into a high-temperature tubular furnace for secondary carbonization to obtain the hard carbon material with uniform stepped pore volume distribution. According to the method, in-situ depolymerization of bamboo molecules is effectively promoted, sufficient free radicals and precursor cracking fragments can be generated at low temperature, and optimization of a carbon layer structure is achieved in the reassembly process. The bamboo-based hard charcoal also has the characteristics of uniform pore volume distribution and quasi-circular closed pore structure, and the sodium / lithium battery prepared from the bamboo-based hard charcoal shows excellent electrochemical performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy materials, and particularly relates to a preparation method and application of bamboo-based hard carbon materials based on pore structure regulation, and more particularly to a preparation method of high-capacity bamboo-based hard carbon materials based on pore structure regulation and its energy storage application. Background Art

[0002] To cope with the increasingly severe energy crisis, it is particularly urgent to promote the development and application of renewable energy. Affected by reasons such as the intermittency of renewable energy supply, its large-scale development has been greatly restricted. The application of large-scale energy storage technology can effectively avoid the disadvantage of unstable energy supply. Therefore, large-scale energy storage technology has become one of the core technologies to promote the efficient utilization of renewable energy. At present, the demand for cost-effective electrochemical energy storage solutions is increasing in various countries. Rechargeable sodium / lithium batteries are ideal energy storage devices due to the high abundance and low cost of metals such as sodium and lithium.

[0003] As a new type of carbon anode material, hard carbon is composed of graphite microcrystals cross-linked and stacked in an amorphous structure, with rich intrinsic defects, larger interlayer spacing, and abundant closed pores, so it can provide more ion diffusion paths and storage sites. The main raw materials for the production of hard carbon include resins, mineral resources, and biomass, etc. Among them, biomass has the characteristics of natural regeneration and rich resources. Bamboo has a natural porous structure, with advantages such as easy regulation of pore structure and rich active groups, providing more possibilities for the regulation of hard carbon structure, and is an ideal hard carbon precursor.

[0004] Bamboo-based hard carbon has received great attention from researchers. In terms of molecular structure, bamboo is mainly composed of cellulose, hemicellulose, and lignin, and contains rich hydroxyl structures. Bamboo molecules will rapidly lose weight intensively during the thermal conversion process, resulting in a greatly reduced carbon yield. Zhang Zhian et al. treated bamboo-based pre-carbonized materials with acid and alkali solutions, and then obtained hard carbon with good performance and high closed pore content through gas-phase tempering treatment (CN118343734A); Zhang Gaoyue et al. used bamboo joints as raw materials and prepared bamboo joint hard carbon materials with high closed pore capacity by pre-carbonization combined with high-temperature refining. The bamboo joint hard carbon materials showed relatively high specific capacity when used as the anode of sodium-ion batteries (Biomass Chemical Engineering. 2023, 57, 6). Li Chuang et al. from the University of Science and Technology of China used two methods of pretreatment and template carbonization to extract high-closed pore capacity hard carbon materials from bamboo powder. The introduction of the template greatly increased the specific surface area of the hard carbon, thus showing good cycle stability (ChemistryOpen. 2024, 1-9).

[0005] Previous studies on bamboo-based hard carbon mainly focused on the control of pore volume. By using strong acids and bases and introducing templates to maintain the specific surface area, the closed pore volume was increased. However, the increase in closed pore volume often only improved the specific capacity and was not conducive to the improvement of its kinetic performance. In the current research on bamboo-based hard carbon materials, scientists ignored the problem of rapid weight loss during the pyrolysis of bamboo, resulting in generally low carbon yields. Summary of the Invention

[0006] Aiming at the problem that the rapid weight loss during pyrolysis of current bamboo-based hard carbon leads to low carbon yield, the present invention provides a preparation method and application of a bamboo-based hard carbon material based on pore structure regulation. In the present invention, the phosphate group-containing groups in the modification reagent promote the premature cracking of bamboo molecules during the thermal conversion process, enabling the pyrolysis fragments to react with persistent free radicals at a lower temperature to generate carbon-centered free radicals. The phosphate group-containing groups can also crosslink and recombine with the bamboo molecule pyrolysis fragments to introduce more sp 3 hybrid carbon bonds into the carbon matrix. These advantages not only increase the carbon yield but also optimize the closed pore structure. On the basis of maintaining the high capacity of hard carbon, more accessible spaces and channels are provided for the storage of ions, greatly improving its rate and cycle performance.

[0007] To solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A preparation method of a bamboo-based hard carbon material based on pore structure regulation, comprising the following steps:

[0009] Step 1, mixing bamboo powder and a modification reagent and ball milling to obtain a mixed powder;

[0010] Step 2, performing a low-temperature pyrolysis reaction on the mixed powder in an argon atmosphere and keeping warm to obtain bamboo-based pyrolytic carbon;

[0011] Step 3, washing the bamboo-based pyrolytic carbon in an acid solution, and then washing with deionized water, filtering by suction, and drying to obtain neutral bamboo-based pyrolytic carbon;

[0012] Step 4, performing high-temperature carbonization on the neutral bamboo-based pyrolytic carbon in an argon atmosphere and keeping warm to obtain a high-capacity bamboo-based hard carbon material.

[0013] Further, the mass ratio of bamboo powder to the modification reagent in Step 1 is 1:3 - 20:1.

[0014] Further, the modification reagent in Step 1 is any one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, or phytic acid.

[0015] Further, for the ball milling in Step 1, zirconium beads with a number of 10 - 1000 and a volume number ratio of large:medium:small of 1:1:8 - 2:5:3 are used for ball milling.

[0016] Furthermore, the ball milling time in step 1 is 0.1 to 10 hours, and the rotation speed is 200 to 500 rpm.

[0017] Furthermore, in step 2, the heating rate is 1-10°C / min, the pyrolysis reaction temperature is 300-800°C, and the reaction time is 0.1-5 hours.

[0018] Furthermore, the acid solution in step 3 is one of hydrochloric acid, nitric acid and hydrofluoric acid, and the concentration of the acid solution is 1 to 3 mol.

[0019] Furthermore, in step 4, the high-temperature carbonization temperature is 1100-1600° C., the heating rate is 1-10° C. / min, and the carbonization time is 0.1-5 h.

[0020] A bamboo-based hard carbon material based on pore structure regulation, wherein the graphite-like microcrystalline interlayer spacing of the bamboo-based hard carbon material is 0.35-0.45nm and the specific surface area is 1-300m 2 / g, and the charcoal yield is 15-40wt.%.

[0021] Application of bamboo-based hard carbon material in sodium / lithium ion battery negative electrode based on pore structure regulation.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The present invention proposes to modify bamboo by cross-linking of a modifying agent, which greatly improves the carbon yield. And by means of phosphate groups, the bamboo molecules can be cracked in advance and the three-element molecular fragments can be reorganized in situ, which greatly optimizes the closed-pore structure of hard carbon. The prepared hard carbon material has the advantage of uniform step pore volume distribution. The method appropriately expands the specific surface area and pore volume of the hard carbon material, and obtains a hard carbon material with excellent rate performance and lithium storage capacity.

[0024] 2. The high capacity bamboo-based hard carbon material of the present invention has a large graphite microcrystalline interlayer spacing of 0.35 to 0.45 nm and a low specific surface area of ​​1 to 300 m 2 / g and good conductivity, providing more space and channels for the storage of sodium ions, and possessing excellent first coulombic efficiency and reversible capacity.

[0025] 3. The preparation process of the present invention is simple, environmentally friendly, easy to operate, and easy to achieve large-scale production of low-cost, high-capacity hard carbon materials. At the same time, high carbon fixation is also a process of low cost, high value and achieving "carbon neutrality", which will produce potential objective environmental benefits and economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 Thermogravimetric curves of the modified bamboo-based sample prepared in Example 1 and the natural bamboo powder in Comparative Example 1.

[0028] Figure 2 Charge-discharge curves of the sodium-ion battery of the high-capacity bamboo-based hard carbon prepared in Example 1 and the natural bamboo-based hard carbon in Comparative Example 1.

[0029] Figure 3 Charge-discharge curves of the lithium-ion battery of the high-capacity bamboo-based hard carbon prepared in Example 4 and the natural bamboo-based hard carbon in Comparative Example 1. Detailed implementation manners

[0030] To deeply understand the present invention, we will describe it comprehensively and meticulously. However, the present invention has multiple implementation manners and is not limited to the specific examples listed herein. The presentation of these examples aims to deepen the comprehensive understanding of the disclosed content of the present invention.

[0031] Example 1

[0032] Step 1: Put bamboo powder and diammonium hydrogen phosphate into a ball milling tank at a mass ratio of 10:9. Then continue to add 200 zirconium beads with a large, medium, and small ratio of 2:5:3 to the ball milling tank, and use a ball mill to mix and ball mill for 0.5 hours to obtain a mixed powder.

[0033] Step 2: Perform a low-temperature pyrolysis reaction on the above mixed powder under an argon atmosphere. The heating rate is 2 °C / min, and perform a low-temperature pyrolysis reaction at 600 °C for 0.5 hours to obtain bamboo-based pyrolytic carbon, and cool it to room temperature and take it out.

[0034] Step 3: Put the cooled bamboo-based pyrolytic carbon into a 1 mol hydrochloric acid solution for washing, and then wash, filter, and dry it with deionized water to obtain neutral bamboo-based pyrolytic carbon.

[0035] Step 4: Carbonize the above neutral bamboo-based pyrolytic carbon at 1300 °C for 2 hours under an argon atmosphere, and the heating rate is 2 °C / min. After cooling to room temperature, take it out to obtain a high-performance modified capacity bamboo-based hard carbon material.

[0036] The carbon yield of the bamboo-based hard carbon material prepared in Example 1 is 30 wt.%, the specific surface area is 31.9 m 2 / g, and the interlayer spacing is 0.371 nm. Figure 1It can be seen that the carbon yield of Comparative Example 1 is 21 wt.% at 600 °C, and the carbon yield of Example 1 is 42 wt.% at 600 °C. The increase in carbon yield is because the phosphate group-containing can undergo an esterification cross-linking reaction with functional groups such as hydroxyl groups in bamboo molecules, thereby retaining more precursor pyrolysis fragments. The prepared bamboo-based hard carbon material powder is mixed with carbon black, sodium carboxymethylcellulose, and styrene-butadiene rubber in a mass ratio of 91:2:2:5 to form a slurry, and then the slurry is evenly scraped onto the current collector copper foil and cut into electrode sheets after drying. The battery is assembled in a glove box under an Ar atmosphere, using metallic sodium as the counter electrode and 1M NaPF6 (in diglyme solution) solution as the electrolyte to assemble a CR2032 coin cell. After testing, the reversible specific capacity of this hard carbon negative electrode is 382.4 mAh / g at a current density of 30 mA / g, and the initial Coulombic efficiency is 84.5%. From Figure 2 It can be seen that the reversible capacities of the sodium-ion half-cells prepared in Comparative Example 1 and Example 1 are 281 and 382.4 mAh / g at 30 mA / g, respectively. The increase in the reversible capacity of Example 1 is because a uniform stepped closed pore volume distribution is introduced during the reassembly process.

[0037] Example 2

[0038] Step 1: Put bamboo powder and ammonium dihydrogen phosphate into a ball milling tank in a mass ratio of 5:3. Then add 1000 zirconium beads with a large, medium, and small ratio of 1:2:7 to the ball milling tank, and use a ball mill to mix and ball mill for 0.1 hour to obtain a mixed powder;

[0039] (2) Carry out a low-temperature pyrolysis reaction on the above mixed powder under an argon atmosphere. The heating rate is 5 °C / min, and the low-temperature pyrolysis reaction is carried out at 300 °C for 0.1 hour to obtain bamboo-based pyrolytic carbon, which is cooled to room temperature and taken out;

[0040] (3) Put the cooled bamboo-based pyrolytic carbon into a 3 mol nitric acid solution for washing, and then wash, filter by suction, and dry with deionized water to obtain neutral bamboo-based pyrolytic carbon;

[0041] (4) Carbonize the above neutral bamboo-based pyrolytic carbon at 1100 °C for 3 hours under an argon atmosphere, with a heating rate of 5 °C / min. After cooling to room temperature, take it out to obtain a high-capacity bamboo-based hard carbon material.

[0042] The carbon yield of the bamboo-based hard carbon material prepared in Example 2 is 29 wt.%, and the specific surface area is 22.5 m 2 / g, the layer spacing is 0.372 nm. The prepared bamboo-based hard carbon material powder is mixed with carbon black, sodium carboxymethylcellulose, and styrene-butadiene rubber in a mass ratio of 91:2:2:5 to form a slurry, and then the slurry is evenly coated on the current collector copper foil, dried and cut into electrode sheets. The battery is assembled in a glove box under an Ar atmosphere, using metallic sodium as the counter electrode and 1 M NaPF6 (in diglyme solution) solution as the electrolyte to assemble a CR2032 coin cell. After testing, the reversible specific capacity of this hard carbon negative electrode is 349.6 mAh / g at a current density of 30 mA / g, and the initial Coulombic efficiency is 86.3%.

[0043] Example 3

[0044] Step 1, put bamboo powder and sodium dihydrogen phosphate into a ball mill tank according to a mass ratio of 10:3. Then add 50 zirconium beads with a large, medium, and small ratio of 1:1:8 to the ball mill tank, and use a ball mill to mix and mill for 3 hours to obtain the mixed powder;

[0045] (2) Carry out a low-temperature pyrolysis reaction on the above mixed powder under an argon atmosphere. The heating rate is 1 °C / min, and a low-temperature pyrolysis reaction is carried out at 800 °C for 5 hours to obtain bamboo-based pyrolytic carbon, which is taken out after cooling to room temperature;

[0046] (3) Put the cooled bamboo-based pyrolytic carbon into a 2 mol hydrofluoric acid solution for washing, and then wash, filter by suction, and dry with deionized water to obtain neutral bamboo-based pyrolytic carbon;

[0047] (4) Carbonize the above neutral bamboo-based pyrolytic carbon at 1400 °C for 4 hours under an argon atmosphere, with a heating rate of 1 °C / min. After cooling to room temperature, take it out to obtain a high-capacity bamboo-based hard carbon material.

[0048] The carbon yield of the bamboo-based hard carbon material prepared in Example 3 is 26 wt.%, and the specific surface area is 7.1 m 2 / g, the layer spacing is 0.372 nm. The prepared bamboo-based hard carbon material powder is mixed with carbon black, sodium carboxymethylcellulose, and styrene-butadiene rubber in a mass ratio of 91:2:2:5 to form a slurry, and then the slurry is evenly coated on the current collector copper foil, dried and cut into electrode sheets. The battery is assembled in a glove box under an Ar atmosphere, using metallic sodium as the counter electrode and 1 M NaPF6 (in diglyme solution) solution as the electrolyte to assemble a CR2032 coin cell. After testing, the reversible specific capacity of this hard carbon negative electrode is 297.9 mAh / g at a current density of 30 mA / g, and the initial Coulombic efficiency is 81.9%.

[0049] Example 4

[0050] Step 1: Put bamboo powder and potassium dihydrogen phosphate into a ball milling tank at a mass ratio of 1:3. Then continue to add 300 zirconium beads with a large, medium and small ratio of 2:5:3 into the ball milling tank, and use a ball mill to mix and ball mill for 10 hours to obtain the mixed powder;

[0051] (2) Carry out a low-temperature pyrolysis reaction on the above-mentioned mixed powder under an argon atmosphere. The heating rate is 3°C / min, and carry out a low-temperature pyrolysis reaction at 500°C for 4.5 hours to obtain bamboo-based pyrolytic carbon, and take it out after cooling to room temperature;

[0052] (3) Put the cooled bamboo-based pyrolytic carbon into a 2 mol hydrochloric acid solution for washing, and then wash, filter by suction and dry with deionized water to obtain neutral bamboo-based pyrolytic carbon;

[0053] (4) Carbonize the above-mentioned neutral bamboo-based pyrolytic carbon at 1500°C for 3.5 hours under an argon atmosphere, and the heating rate is 3°C / min. After cooling to room temperature, take it out to obtain a high-capacity bamboo-based hard carbon material.

[0054] The carbon yield of the bamboo-based hard carbon material prepared in Example 4 is 28 wt.%, the specific surface area is 20.7 m2 / g, and the layer spacing is 0.370 nm. Mix the prepared bamboo-based hard carbon material powder, carbon black, sodium carboxymethyl cellulose, and styrene-butadiene rubber according to a mass ratio of 91:2:2:5 to form a slurry, and then evenly scrape the slurry onto the current collector copper foil, and cut it into electrode sheets after drying. The battery is assembled in a glove box under an Ar atmosphere, using metallic lithium as the counter electrode and a solution of 1 M LiPF6 in EC / DMC / EMC (v / v / v = 1:1:1) as the electrolyte to assemble a CR2032 button battery. After testing, the reversible specific capacity of this hard carbon negative electrode is 227.6 mAh / g at a current density of 30 mA / g, and the first Coulomb efficiency is 61.1%. It can be seen from Figure 3 that the reversible capacities of the lithium-ion half-cells prepared in Comparative Example 1 and Example 4 are 207.3 and 227.6 mAh / g respectively at 30 mA / g. The increase in the reversible capacity of Example 4 is because the carbon layer structure was optimized during the reassembly process, enabling the hard carbon to have a uniform stepped pore volume distribution structure.

[0055] Example 5

[0056] Step 1: Put bamboo powder and phytic acid into a ball milling tank at a mass ratio of 20:1. Then continue to add 1000 zirconium beads with a large, medium and small ratio of 1:5:4 into the ball milling tank, and use a ball mill to mix and ball mill for 8 hours to obtain the mixed powder;

[0057] (2) Carry out a low-temperature pyrolysis reaction on the above-mentioned mixed powder under an argon atmosphere. The heating rate is 10°C / min, and carry out a low-temperature pyrolysis reaction at 700°C for 1 hour to obtain bamboo-based pyrolytic carbon, and take it out after cooling to room temperature;

[0058] (3) Wash the cooled bamboo-based pyrolytic carbon above in a 2 mol nitric acid solution, and then wash, filter by suction, and dry it with deionized water to obtain neutral bamboo-based pyrolytic carbon;

[0059] (4) Carbonize the above neutral bamboo-based pyrolytic carbon at 1600 °C for 3 hours in an argon atmosphere, with a heating rate of 10 °C / min. After cooling to room temperature, take it out to obtain a high-capacity bamboo-based hard carbon material.

[0060] The carbon yield of the bamboo-based hard carbon material prepared in Example 5 is 23 wt.%, the specific surface area is 4.2 m 2 / g, and the interlayer spacing is 0.370 nm. Mix the prepared bamboo-based hard carbon material powder with carbon black, sodium carboxymethyl cellulose, and styrene-butadiene rubber in a mass ratio of 91:2:2:5 to form a slurry, and then evenly scrape the slurry onto the current collector copper foil, and cut it into electrode sheets after drying. The battery is assembled in a glove box under an Ar atmosphere, using metallic sodium as the counter electrode and 1 M NaPF6 (bis(2-methoxyethyl) ether solution) solution as the electrolyte to assemble a CR2032 coin cell. After testing, the reversible specific capacity of this hard carbon negative electrode is 295.4 mAh / g at a current density of 30 mA / g, and the first Coulombic efficiency is 86.3%.

[0061] Comparative Example 1

[0062] Step 1: Put natural bamboo powder into a ball mill tank. Continue to add 200 zirconium beads with a large, medium, and small ratio of 1:1:8 to the ball mill tank, and use the ball mill to mix and mill for 1 hour to obtain its mixed powder;

[0063] (2) Carry out a low-temperature pyrolysis reaction on the above natural bamboo powder in an argon atmosphere. The heating rate is 2 °C / min, and carry out a low-temperature pyrolysis reaction at 600 °C for 0.5 hours to obtain bamboo-based pyrolytic carbon, and take it out after cooling to room temperature;

[0064] (3) Wash the cooled bamboo-based pyrolytic carbon above in a 1 mol hydrochloric acid solution, and then wash, filter by suction, and dry it with deionized water to obtain neutral bamboo-based pyrolytic carbon;

[0065] (4) Carbonize the above neutral bamboo-based pyrolytic carbon at 1300 °C for 2 hours in an argon atmosphere, with a heating rate of 2 °C / min. After cooling to room temperature, take it out to obtain a natural bamboo-based hard carbon material.

[0066] The carbon yield of the natural bamboo-based hard carbon material prepared in Comparative Example 1 is 21 wt.%, and the specific surface area is 2.6 m 2 / g, and the layer spacing is 0.371 nm. The prepared natural bamboo-based hard carbon material powder is mixed with carbon black, sodium carboxymethyl cellulose, and styrene-butadiene rubber in a mass ratio of 91:2:2:5 to form a slurry, and then the slurry is evenly spread on the current collector copper foil, and after drying, it is cut into electrode sheets. The battery is assembled in a glove box under an Ar atmosphere, using metallic sodium as the counter electrode and 1M NaPF6 (in diglyme solution) solution as the electrolyte to assemble a CR2032 coin cell. After testing, the reversible specific capacity of this hard carbon negative electrode is 281 mAh / g at a current density of 30 mA / g, and the initial Coulombic efficiency is 85.3%.

[0067] The prepared natural bamboo-based hard carbon material powder is mixed with carbon black, sodium carboxymethyl cellulose, and styrene-butadiene rubber in a mass ratio of 91:2:2:5 to form a slurry, and then the slurry is evenly spread on the current collector copper foil, and after drying, it is cut into electrode sheets. The battery is assembled in a glove box under an Ar atmosphere, using metallic lithium as the counter electrode and 1M LiPF6 in EC / DMC / EMC (v / v / v = 1:1:1) solution as the electrolyte to assemble a CR2032 coin cell. After testing, the reversible specific capacity of this hard carbon negative electrode is 207.3 mAh / g at a current density of 30 mA / g, and the initial Coulombic efficiency is 64.6%.

[0068] The content not detailedly described in the specification of the present invention belongs to the prior art well-known to those skilled in the art. Although the illustrative specific embodiments of the present invention are described above for the understanding of those skilled in the art of the present technology, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of the present technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions created using the concept of the present invention are within the scope of protection.

Claims

1. A method for preparing bamboo-based hard carbon material based on pore structure regulation, characterized in that: The following steps are involved: Step 1, mixing bamboo powder and a modifying agent and ball-milling them to obtain a mixed powder; Step 2, subjecting the mixed powder to a low-temperature pyrolysis reaction under an argon atmosphere and keeping the temperature, to obtain bamboo-based pyrolytic carbon; Step 3, washing the bamboo-based pyrolytic carbon in an acid solution, then washing with deionized water, filtering, and drying to obtain neutral bamboo-based pyrolytic carbon; Step 4, carbonizing the neutral bamboo-based pyrolytic carbon at high temperature in an argon atmosphere and keeping the temperature, to obtain a high-capacity bamboo-based hard carbon material.

2. The method for preparing a bamboo-based hard carbon material based on pore structure regulation according to claim 1, characterized in that: In the step 1, the mass ratio of bamboo powder to modifying agent is 1:3-20:

1.

3. The method for preparing a bamboo-based hard carbon material based on pore structure regulation according to claim 1, characterized in that: The modifying agent in step 1 is any one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate or phytic acid.

4. The method for preparing a bamboo-based hard carbon material based on pore structure regulation according to claim 1, characterized in that: The ball milling in step 1 is performed using 10 to 1000 zirconium beads with a volume ratio of large: medium: small of 1:1:8 to 2:5:

3.

5. The method for preparing a bamboo-based hard carbon material based on pore structure regulation according to claim 1, characterized in that: The ball milling time in step 1 is 0.1 to 10 hours, and the rotation speed is 200 to 500 rpm.

6. The method for preparing a bamboo-based hard carbon material based on pore structure regulation according to claim 1, characterized in that: In step 2, the heating rate is 1-10°C / min, the pyrolysis reaction temperature is 300-800°C, and the reaction time is 0.1-5 hours.

7. The method for preparing a bamboo-based hard carbon material based on pore structure regulation according to claim 1, characterized in that: The acid solution in step 3 is one of hydrochloric acid, nitric acid and hydrofluoric acid, and the concentration of the acid solution is 1 to 3 mol.

8. The method for preparing a bamboo-based hard carbon material based on pore structure regulation according to claim 1, characterized in that: In step 4, the high-temperature carbonization temperature is 1100-1600° C., the heating rate is 1-10° C. / min, and the carbonization time is 0.1-5 h.

9. A bamboo-based hard carbon material based on pore structure regulation obtained by the preparation method according to any one of claims 1 to 8, characterized in that: The graphite-like microcrystal interlayer spacing of the bamboo-based hard carbon material is 0.35-0.45 nm, and the specific surface area is 1-300 m 2 / g, and the charcoal yield is 15-40wt.%.

10. Use of a bamboo-based hard carbon material based on pore structure regulation obtained by the preparation method according to any one of claims 1 to 8 in a negative electrode of a sodium / lithium ion battery.

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