Graphitized controllable biomass carbon negative electrode material for batteries and preparation method thereof

Abstract

The application discloses a kind of graphitization controllable biomass carbon battery negative material and its preparation method, method includes the following steps: step 1: using bamboo processing waste as precursor, bamboo processing waste is classified, broken and sieved, different types of precursor are treated with targeted acid treatment scheme, for removing non-structural components and impurities in precursor;Step 2: using alkaline transition metal salt solution to regulate the content and form of the structure component of the precursor after crushing and impurity removal;Step 3: the precursor treated in step 2 is washed, pre-burned and sintered;Step 4: the carbon material after sintering in step 3 is surface modified;Step 4 in the application.By regulating the composition of the precursor and the sintering conditions, the controllable design of the degree of graphitization of biomass carbon is realized.The obtained carbon material is used as a sodium-ion battery negative material, which has high specific capacity and good cycle stability.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of carbon battery material preparation, in particular to a graphitized controllable biomass carbon battery negative electrode material and a preparation method thereof. BACKGROUND

[0002] Fossil energy depletion and environmental deterioration make people pay attention to the development and utilization of renewable energy. Developing solar and wind power generation technology meets the requirements of sustainable development. However, the electric energy generated by clean energy often has timeliness and intermittency, so it is necessary to store energy to improve the quality of energy to realize power grid connection. Since the physical energy storage methods such as pumped storage and compressed air energy storage have low energy storage efficiency and are high in investment cost due to local conditions, it is necessary and urgent to develop high-efficiency, flexible-scale and low-cost energy storage devices for the effective utilization of clean energy. Electrochemical energy storage has the advantages of high energy storage efficiency and low investment cost, and since it has high energy efficiency and long service life, alkali metal ion batteries such as lithium and sodium ion batteries have the potential to be applied in large-scale energy storage. The main factors determining the performance and cost of alkali metal ion batteries are positive and negative electrode materials. In practical applications, in order to improve the working efficiency of the positive electrode material, more negative electrode materials are often needed to realize capacity matching, so reducing the cost of the negative electrode material is beneficial to the large-scale application of the battery in energy storage.

[0003] Carbon materials have the advantages of easy availability and low cost, and the diverse electronic states make carbon materials have rich and adjustable structures, and the working potential of carbon materials is low, which is an ideal negative electrode material of a battery. In the development of carbon materials, the selection and processing technology of the precursor are very important, which directly determines the electrochemical performance and industrialization cost of the carbon material. Biomass has diverse structures and is an ideal precursor of carbon materials, and the carbon material designed by using the biomass precursor has unique morphology and microstructure.

[0004] The design and regulation scheme of biomass-derived carbon materials mainly includes pretreatment before sintering, optimization of sintering conditions and post-treatment after sintering. The means of pretreatment before sintering mainly include ball milling, acid and alkali treatment, metal salt solution treatment, etc., the purpose is mainly to reduce the particle size of the precursor, to regulate the composition of the precursor, to design the structure of the precursor and to introduce doping atoms, etc. The means of optimizing sintering conditions mainly include adjusting the heating rate of pre-sintering and high-temperature sintering, controlling the reaction atmosphere, etc., the purpose is mainly to regulate the degree of different chemical reactions and the sintering rate during sintering, to introduce doping atoms and to realize coating, etc. The means of post-treatment after sintering mainly include surface modification, redox treatment, etc., the purpose is mainly to improve the compatibility of hard carbon and electrolyte, to introduce functional functional groups.

[0005] In the development of biomass carbon materials, each enterprise has its own processing technology, which is a parallel trend. Among them, the product of Japan Kureha Corporation is the most mature, but the process is more complicated. It uses coconut shell as raw material, and goes through crushing, alkali impregnation, heat treatment purification, carbonization and CVD treatment. The CVD treatment process is more difficult.

[0006] As a domestic enterprise aiming at Kureha, the biomass carbon material product of Baisige uses glucose, starch and lignin as raw materials, and can obtain sodium-ion battery hard carbon negative electrode material meeting fast-charging performance through modification treatment, pyrolysis and polycondensation, carbonization and surface modification steps. The process of the company's product is simpler than that of foreign enterprises, and the cost is more low-cost, and the selling price is about 1 / 2 of overseas enterprises (CN111834614A, CN111834613A).

[0007] The biomass carbon material technology of traditional lithium battery negative electrode enterprises such as Betta, Sunward, Zhongke Xingcheng and Xiangfenghua in China has been developed, including hard carbon CN111509198A based on plant precursors such as rice husk, corn cob, fruit shell, hard carbon CN114835104A based on hazelnut shell precursor, and hard carbon CN111439738A based on peanut shell, coconut shell and walnut shell precursor.

[0008] At present, although various design processing means of biomass carbon materials have been developed, the microcosmic understanding of amorphous carbon materials is still lacking, the universal mechanism of sintering change and graphitization of biomass-derived carbon materials cannot be explained, resulting in that the design regulation of biomass-derived carbon materials lacks criteria, and it is difficult to establish the relationship between the results of pre-treatment, sintering and post-treatment and the structure-activity relationship of carbon materials themselves. Meanwhile, the intrinsic structure of biomass precursors is difficult to be completely regulated, and the original morphology characteristics are still retained after high-temperature calcination. SUMMARY

[0009] The purpose of the present application is to provide a graphitizable controllable biomass carbon battery negative material and a preparation method thereof. The present application realizes the controllable design of the graphitization degree of biomass carbon by regulating the composition of the precursor and the sintering conditions. The obtained carbon material is used as a sodium ion battery negative material, which has high specific capacity and good cycle stability.

[0010] To solve the above technical problems, the technical scheme adopted by the present application is:

[0011] A preparation method of a graphitizable controllable biomass carbon battery negative material, at least comprising the following steps:

[0012] Step 1: using bamboo processing waste as a precursor, classifying, crushing and sieving the bamboo processing waste, and using targeted acid treatment scheme for different types of precursors to remove non-structural components and impurities in the precursors;

[0013] Step 2: using an alkaline transition metal salt solution to regulate the content and morphology of the structural components of the crushed and impurity-removed precursor;

[0014] Step 3: washing the precursor treated in step 2, and then pre-burning and sintering;

[0015] Step 4: surface modification of the carbon material after sintering in step 3;

[0016] In step 4, the carbon material obtained in step 3 is soaked in a mixture of 10 mL of sulfuric acid with a concentration of 1-1.5 M and 2 mL of hydrogen peroxide for 8-12 min, to obtain a negative material for a sodium ion battery.

[0017] In step 1, the bamboo processing waste includes leftover materials generated during the bamboo processing process and impurities introduced during the processing process;

[0018] The specific steps of step 1 are as follows:

[0019] First, separate different parts of the bamboo, separate the bamboo branches, bamboo stems and bamboo joints according to the hardness and morphology, dry and crush, and sieve, and then separate the precursors with particle size greater than 100 mesh and less than 100 mesh for the second time;

[0020] Then, the non-structural components in the precursor, including proteins, lipids and impurities, are removed by acid treatment.

[0021] Further, different acid treatment schemes are adopted for different types of precursors.

[0022] The precursor particles with a particle size greater than 100 mesh are treated by hydrochloric acid reflux, and the precursor is added to a hydrochloric acid solution with a concentration of 0.5-1M in an oil bath at 110-130℃, and is condensed and refluxed for 1-2h.

[0023] The bamboo joints are crushed, and the hardness of the particles is relatively high. The precursor particles with a particle size greater than 100 mesh are treated by hydrochloric acid reflux, and the precursor is added to a hydrochloric acid solution with a concentration of 0.5-1M in an oil bath at 110-130℃, and is condensed and refluxed for 1-2h.

[0024] In step 2, the specific steps are as follows: the precursor after removing the non-structural components and impurities is mixed, and is stirred in a weak alkaline pH=8, 0.001M ferric chloride solution with the addition of sodium hydroxide for 8-12min.

[0025] In step 3, when sintering, the treated precursor is heated at a rate of 4-6℃ / min -1 to 300℃, and is kept for 2.5-3.5h, and then is heated at a rate of 4-6℃ / min -1 to 1300℃, and is kept for 2.5-3.5h.

[0026] In addition, the application also discloses a graphitized controllable biomass carbon negative electrode material.

[0027] Compared with the prior art, the application has the following beneficial effects:

[0028] The application uses bamboo processing waste as a precursor, combines hot water bath and acid-base treatment, transition metal salt solution treatment, and realizes controllable design of the graphitization degree of biomass carbon by adjusting the composition of the precursor and the sintering conditions. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0030] Figure 1 XRD pattern of the precursor of the present application after carbonization after treatment with 0.1M sodium hydroxide solution at 80℃ for different time.

[0031] Figure 2 XRD pattern of the precursor of the present application after carbonization after treatment with different concentration of ferric chloride solution for 2h.

[0032] Figure 3 XRD pattern of the precursor of the present application after carbonization after treatment with sodium hydroxide and ferric chloride solution for 10min.

[0033] Figure 4 SEM pattern of the precursor of the present application after carbonization without sodium hydroxide and ferric chloride treatment.

[0034] Figure 5 SEM pattern of the precursor of the present application after carbonization with sodium hydroxide and ferric chloride treatment.

[0035] Figure 6 Sodium storage performance pattern of the precursor of the present application after carbonization after treatment with 0.1M sodium hydroxide solution at 80℃ for different time.

[0036] Figure 7 Sodium storage performance pattern of the precursor of the present application after carbonization after treatment with different concentration of ferric chloride solution for 2h.

[0037] Figure 8 Sodium storage performance pattern of the precursor of the present application after carbonization after treatment with sodium hydroxide and ferric chloride solution for 10min.

[0038] Figure 9 Sodium storage long cycle curve pattern of the carbon material of the present application after sintering and treatment with sulfuric acid / hydrogen peroxide. DETAILED DESCRIPTION

[0039] In the following, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the embodiments of the present application. Therefore, the drawings and the description are considered to be exemplary in nature rather than limiting. The embodiments of the present application are described in detail below in conjunction with the drawings.

[0040] The embodiment discloses a preparation method of a graphitized controllable biomass carbon negative electrode material, and has at least the following steps:

[0041] Step 1: using bamboo processing waste as a precursor, the bamboo processing waste is classified, crushed and sieved, and different types of precursors are subjected to targeted acid treatment schemes to remove non-structural components and impurities in the precursors;

[0042] Step 2: using an alkaline transition metal salt solution to regulate the content and morphology of the structural components of the crushed and impurity-removed precursors;

[0043] Step 3: washing the precursors treated in step 2, and then pre-burning and sintering;

[0044] Step 4: surface modification of the sintered carbon material in step 3 is performed;

[0045] In step 4, the carbon material obtained in step 3 is soaked in a mixture of 10 mL of sulfuric acid with a concentration of 1-1.5 M and 2 mL of hydrogen peroxide for 8-12 min to obtain a negative electrode material for a sodium ion battery.

[0046] In step 1, the bamboo processing waste includes leftover materials generated during the bamboo processing and impurities introduced during the processing; first, different parts of the bamboo are separated, and the bamboo branches, bamboo stems and bamboo joints are separated according to the hardness and morphology, dried, crushed and sieved, and the precursors with a particle size greater than 100 mesh and less than 100 mesh are subjected to a second separation; then, the non-structural components including proteins, lipids and impurities are removed by acid treatment. Different acid treatment schemes are used for different types of precursors, wherein the crushed bamboo branches and bamboo stems have relatively low hardness, and the precursor particles with a particle size less than 100 mesh are treated by acid washing, and the precursors are added to a hydrochloric acid solution with a concentration of 0.5-1 M in a 70-90°C hot water bath and stirred for 1-2 h;

[0047] The precursor particles with a particle size greater than 100 mesh are treated by hydrochloric acid reflux, and the precursors are added to a hydrochloric acid solution with a concentration of 0.5-1 M in an oil bath at 110-130°C and condensed and refluxed for 1-2 h;

[0048] The crushed bamboo joints have relatively high hardness, and the precursor particles with a particle size less than 100 mesh are treated by 0.5-1 M hydrochloric acid condensation reflux at 110-130°C for 2-3 h, and the precursor particles with a particle size greater than 100 mesh are treated by 0.5-1 M hydrochloric acid condensation reflux at 110-130°C for 3-4 h.

[0049] The step 2 is specifically as follows: the precursor after removing non-structural components and impurities is mixed, and then stirred in a weak alkaline solution of 0.001-0.005M iron chloride solution with the addition of sodium hydroxide at pH=8 for 8-12min.

[0050] Further, in the step 3, the treated precursor is sintered at a temperature increasing rate of 4-6℃ / min -1 The temperature is increased to 300℃ for 2.5-3.5h, and then the temperature is increased at a rate of 4-6℃ / min -1 The precursor is carbonized under a temperature increasing procedure of increasing the temperature to 1300℃ and keeping the temperature for 2.5-3.5h.

[0051] In order to make the present application more comprehensible to those skilled in the art, the present application is further described below in combination with specific preparation cases.

[0052] The present application mainly uses bamboo processing waste as a precursor, including leftover materials generated in the bamboo processing and impurities introduced in the processing.

[0053] Firstly, different parts of the bamboo are separated, and the bamboo branches, bamboo stems and bamboo joints are separated according to the hardness and morphology. After drying and crushing, the precursor with a particle size greater than 100 mesh and less than 100 mesh is secondarily separated.

[0054] Then, the non-structural components and impurities in the precursor are removed by acid treatment, and the non-structural components include proteins and lipids.

[0055] Different acid treatment schemes are adopted for different types of precursors. The crushed bamboo branches and stems have relatively low hardness, and the precursor particles with a particle size less than 100 mesh are treated by acid washing. The precursor is added into a hydrochloric acid solution with a concentration of 0.5-1M in a hot water bath at 80℃ and stirred for 1-2h.

[0056] The precursor particles with a particle size greater than 100 mesh are treated by hydrochloric acid reflux. The precursor is added into a hydrochloric acid solution with a concentration of 0.5-1M in an oil bath at 120℃ and condensed and refluxed for 1-2h. The crushed bamboo joints have relatively high hardness, and the precursor particles with a particle size less than 100 mesh are treated by 0.5-1M hydrochloric acid condensation reflux at 120℃ for 2-3h, and the precursor particles with a particle size greater than 100 mesh are treated by 0.5-1M hydrochloric acid condensation reflux at 120℃ for 3-4h.

[0057] The two-step separation and targeted acid treatment scheme can not only remove the impurities in the precursor sufficiently, but also reduce the irreversible capacity caused by defects without causing excessive damage to the structure of the precursor.

[0058] The content and morphology of the structural components (cellulose, hemicellulose and lignin) of the crushed and impurity-removed precursor are regulated, and then the graphitization degree of the carbon material after sintering is regulated.

[0059] The present application utilizes sodium hydroxide and ferric chloride solution to regulate the content of amorphous hemicellulose and lignin in the precursor. The content of amorphous component will be reflected in the graphitization degree of the carbonized precursor. In the development of the present application, the removal of amorphous component by sodium hydroxide and ferric chloride is proved to have a synergistic effect, as shown in the accompanying Figures 1-3 Although sodium hydroxide or ferric chloride can be used alone, the content of amorphous component can be regulated by changing the solution concentration and reaction conditions, but a higher concentration of solution and a longer heating treatment time are required.

[0060] Taking the use of sodium hydroxide alone as an example, the precursor needs to be treated in 0.1M sodium hydroxide solution at 80℃ water bath for 6h, and the carbon material after sintering can obtain good graphitization degree.

[0061] For the precursor used in the present patent, only 10min stirring of the precursor in the weakly alkaline (pH=8) 0.001-0.005M ferric chloride solution with the addition of sodium hydroxide is needed, and the carbon material with the best graphitization degree for sodium storage can be obtained. The present application has small reagent dosage, high treatment efficiency, and has potential for large-scale popularization and application.

[0062] In the present application, the main weight loss temperature range of the precursor is between 200-300℃, and when the temperature continues to rise, the precursor loses weight slowly, and when the temperature reaches about 1300℃, the weight loss of the precursor basically stops. Therefore, in actual use, first increase the temperature to 300℃ at a rate of 5℃ / min -1 and keep it for 3h, then increase the temperature to 1300℃ at a rate of 5℃ / min -1 and keep it for 3h. The 300℃ pre-sintering can make the non-stable components (bound water, etc.) in the precursor fully removed, reducing their influence on subsequent graphitization. The 1300℃ calcination can make the precursor fully carbonized.

[0063] After regulating the content and morphology of the structural components of the precursor, it is inevitable to introduce certain structural defects in the precursor, which increases the irreversible capacity of the carbon material after sintering. Therefore, the present patent designs a mixture of 10mL of sulfuric acid with a concentration of 1-1.5M and 2mL of hydrogen peroxide to soak the carbon material after sintering for 10min, to modify the surface structural defects, introduce oxygen-containing functional groups, and reduce the ion migration energy barrier during work. Experimental results show that after treatment with sulfuric acid and hydrogen peroxide, the cycle stability of the carbon material has been significantly improved.

[0064] The specific preparation example is as follows:

[0065] First, the bamboo processing scraps are sorted into three parts: bamboo branches, bamboo rods and bamboo joints, dried and crushed. Then, the bamboo branch and rod particles with a particle size less than 100 mesh are added to a 0.5M hydrochloric acid solution, stirred in a 80℃ hot water bath for 1h, and the bamboo branch and rod particles with a particle size greater than 100 mesh are refluxed with 0.5M hydrochloric acid at 120℃ for 1h. The bamboo joint particles with a particle size less than 100 mesh are refluxed with 0.5M hydrochloric acid at 120℃ for 2h, and the bamboo joint particles with a particle size greater than 100 mesh are refluxed with 0.5M hydrochloric acid at 120℃ for 3h. Then, the precursor with non-structural components and impurities removed is mixed and stirred in a weakly alkaline (pH = 8) 0.001M iron chloride solution with sodium hydroxide added for 10min. The treated precursor is carbonized at a temperature rising program of 5℃ / min -1 to 300℃ for 3h, and then 5℃ / min -1 to 1300℃ for 3h. Finally, the obtained carbon material is soaked in a mixture of 10mL of 1M sulfuric acid and 2mL of hydrogen peroxide for 10min to obtain a negative electrode material for a sodium ion battery.

[0066] More importantly, in the present application, the alkali and transition metal ions have a synergistic effect on increasing the graphitization degree of the carbon material, and the graphitization degree of the carbon material can be continuously controlled by changing the concentrations of NaOH and FeCl3. The weakly alkaline (pH = 8) 0.001M iron chloride with sodium hydroxide added is the optimal condition for sodium storage, and the concentration of FeCl3 can be further increased to obtain high graphitization carbon.

[0067] The XRD results of the precursor treated with 0.1M sodium hydroxide solution at 80℃ for different times and then carbonized are shown in Figure 1 .

[0068] The XRD results of the precursor treated with different concentrations of iron chloride solution for 2h and then carbonized are shown in Figure 2 .

[0069] The XRD results of the precursor treated with sodium hydroxide and iron chloride solution for 10min and then carbonized are shown in Figure 3 .

[0070] As shown in the accompanying Figure 1 , with the extension of the treatment time of sodium hydroxide, the graphitization peak near 26° in the XRD pattern of the carbonized precursor gradually increases, indicating that the graphitization degree is gradually increasing, and the amorphous components in the precursor are gradually removed.

[0071] As shown in the accompanying Figure 2 , with the increase of the concentration of iron chloride solution, the graphitization degree of the treated precursor after carbonization also gradually increases.

[0072] As shown in the accompanying Figure 3As shown, when the precursor is treated simultaneously with a solution prepared from sodium hydroxide and ferric chloride, both the solution concentration and treatment time required to achieve the same degree of graphitization after carbonization are significantly reduced. Therefore, sodium hydroxide and ferric chloride have a synergistic effect on the removal of amorphous components from the precursor and the regulation of the degree of graphitization of carbon materials.

[0073] SEM results of the precursor carbonization without sodium hydroxide and ferric chloride treatment are as follows: Figure 4 As shown, the SEM results of the precursor carbonized after treatment with sodium hydroxide and ferric chloride are as follows: Figure 5 As shown.

[0074] From the appendix Figure 4 and attached Figure 5 As shown, the precursor treated with sodium hydroxide and ferric chloride has more pores on its surface after carbonization, which increases the specific surface area of ​​the carbon material and is beneficial for the storage of alkali metal ions.

[0075] The sodium storage performance of the precursor after carbonization by treatment with 0.1M sodium hydroxide solution at 80℃ for different times is shown in the following figures. Figure 6 As shown;

[0076] The sodium storage performance of the precursor after carbonization by treatment with ferric chloride solutions of different concentrations for 2 hours is as follows: Figure 7 As shown;

[0077] The sodium storage performance structure of the precursor after carbonization by treatment with sodium hydroxide and ferric chloride solution for 10 min is as follows: Figure 8 As shown;

[0078] The sodium storage long-cycle curve of carbon materials treated with sulfuric acid / hydrogen peroxide after sintering is shown below. Figure 9 As shown.

[0079] From the appendix Figure 6 and attached Figure 7 As shown, the sodium storage capacity of carbon materials does not increase indefinitely with increasing graphitization, but rather reaches a maximum value. Excessive graphitization can actually reduce the sodium storage capacity of hard carbon.

[0080] From the appendix Figure 8 As shown, the precursor treated with sodium hydroxide and ferric chloride has a higher sodium storage capacity after carbonization.

[0081] From the appendix Figure 9 As shown, treatment with sodium hydroxide and ferric chloride inevitably introduces defects into carbon materials, causing capacity decay. However, after carbonization of the precursor, treatment with sulfuric acid and hydrogen peroxide suppresses capacity decay.

[0082] While the preferred embodiments of the application have been described, additional variations and modifications can be made to these embodiments by those skilled in the art once they have the benefit of the present disclosure. Therefore, the appended claims are intended to encompass all such variations and modifications as falling within the scope of the application.

[0083] The preferred embodiments of the application described hereinabove are therefore to be considered in all respects as illustrative only and not restrictive in character, since the scope of the application includes any modifications within the spirit and scope of the application as defined in the following claims.

Claims

1. A method for preparing a graphitized controllable biomass carbon anode material, characterized in that, At least comprising the following steps: Step 1: Using bamboo processing waste as precursor, the bamboo processing waste is classified, crushed and sieved, and then different types of precursors are treated with targeted acid treatment scheme to remove non-structural components and impurities in the precursors; Step 2: Using the alkaline transition metal salt solution formed by sodium hydroxide and ferric chloride to regulate the content and morphology of the structural components of the crushed and impurity-removed precursors; Step 3: Washing the precursors treated in step 2, and then pre-burning and sintering; Step 4: Surface modification of the sintered carbon material in step 3 can be done; In step 4, the carbon material obtained in step 3 is soaked in a mixture of 10 mL of 1-1.5 M sulfuric acid and 2 mL of hydrogen peroxide for 8-12 min to obtain a negative electrode material for sodium ion batteries.

2. The method according to claim 1, wherein the method is characterized by: In step 1, the bamboo processing waste includes leftover materials generated during the processing of bamboo and impurities introduced during the processing; The specific steps of step 1 are as follows: First, separate different parts of the bamboo, separate the bamboo branches, bamboo poles and bamboo joints according to the hardness and morphology, dry and crush, and sieve, then separate the precursors with particle size greater than 100 mesh and less than 100 mesh for the second time; Then, use acid treatment to decompose and remove non-structural components and impurities in the precursors, including proteins and lipids.

3. The preparation method of the graphitized controllable biomass carbon battery negative electrode material according to claim 2, characterized in that: Different acid treatment schemes are used for different types of precursors, wherein the hardness of the crushed bamboo branches and bamboo poles is relatively low, and the particle size of the precursors is less than 100 mesh, and the acid washing method is used to treat the precursors, and the precursors are added to a 0.5-1 M hydrochloric acid solution in a 70-90 ℃ hot water bath and stirred for 1-2 h; The particle size of the crushed bamboo branches and bamboo poles is greater than 100 mesh, and the hydrochloric acid reflux treatment is used to treat the precursors, and the precursors are added to a 0.5-1 M hydrochloric acid solution in a 110-130 ℃ oil bath and condensed and refluxed for 1-2 h; The hardness of the crushed bamboo joints is relatively high, and the particle size of the precursors is less than 100 mesh, and the 0.5-1 M hydrochloric acid 110-130 ℃ condensation reflux treatment is used to treat the precursors for 2-3 h, and the particle size of the precursors is greater than 100 mesh, and the 0.5-1 M hydrochloric acid 110-130 ℃ condensation reflux treatment is used to treat the precursors for 3-4 h.

4. The method of claim 2, wherein the method further comprises the step of: The specific steps of step 2 are as follows: mixing the precursors from which the non-structural components and impurities have been removed, stirring in a 0.001-0.005 M ferric chloride solution with weak alkalinity of pH = 8. ​ 5. The method for preparing a graphitized controllable biomass carbon battery anode material according to claim 2, characterized in that, The pre-burning and sintering in step 3 is carried out at a heating rate of 4-6 °C min -1 to 300 °C for 2.5-3.5 h, then at a heating rate of 4-6 °C min -1 Carbonization at a heating program of heating to 1300 °C for 2.5-3.5 h.

6. A graphitized controllable biomass carbon anode material, characterized in that: The graphitized controllable biomass carbon battery negative electrode material is prepared by the preparation method of the graphitized controllable biomass carbon battery negative electrode material according to any one of claims 1-5.

Images