Biomass derived hard carbon negative electrode material for sodium ion battery and preparation method of biomass derived hard carbon negative electrode material
By co-carbonizing aromatic compounds containing zinc and biomass hard carbon materials, closed nanopores are manufactured in three steps, which solves the problem of unstable sodium storage performance of hard carbon materials, achieves the stability and consistency of the material, and simplifies the process flow.
Patent Information
- Application Number
- CN202510284199.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-11
- Publication Date
- 2025-06-06
AI Technical Summary
The prior art is difficult to effectively regulate the nanopore structure of hard carbon materials, resulting in unstable sodium storage performance, and the commonly used methods are complex and highly restrictive.
The zinc-containing aromatic compounds are used to co-carbonize with biomass hard carbon materials, and sealed nanopores are manufactured through three-step carbonization treatment to improve the sodium storage performance of the material.
The sodium storage performance stability and consistency of biomass-derived hard carbon anode materials is achieved, the process flow is simplified, energy consumption is reduced, and it is suitable for different biomass materials.
Smart Images
Figure CN120097322A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of sodium ion batteries, and in particular to a biomass-derived hard carbon negative electrode material, a preparation method and an application thereof. Background Art
[0002] With the growing global energy demand and increasingly severe environmental problems, the development of new and efficient energy storage systems has become particularly important. Sodium-ion batteries (SIBs) are regarded as an important supplement or even alternative technology to lithium-ion batteries (LIBs) in large-scale energy storage and low-speed electric transportation due to their low cost, abundant resources and environmental friendliness. In sodium-ion batteries, the performance of the negative electrode material directly affects the electrochemical performance of the battery, such as energy density, cycle stability and rate performance. Hard carbon (HC) has the advantages of abundant raw materials, low cost, simple preparation process and easy operation, which is conducive to commercial production and is considered to be the most promising anode material. Biomass materials are widely available, low-priced and have excellent performance, making them ideal precursors for the preparation of hard carbon negative electrode materials. However, it is precisely because of the wide source of biomass materials that the properties of derived hard carbons are easily different. It is crucial to develop a suitable carbonization process to obtain hard carbon materials with stable sodium storage performance. This patent uses discarded apple branches and bamboo as biomass raw materials. As a wood-based biomass, discarded apple branches are not only cheap, abundant in resources, and environmentally friendly, but also have rich functional groups, short-range graphite domains, and expandable interlayer spacing. As a fruit tree branch, apple branches contain a large amount of lignin and cellulose, which is very suitable as a source of hard carbon materials with high closed-cell content; bamboo has a short growth cycle, high annual output, and high carbon content. After high-temperature carbonization, it can form a porous structure, increase the specific surface area, and promote the rapid insertion / extraction of sodium ions. It is a commonly used source of hard carbon biomass. In addition, we preliminarily carbonize the original biomass to establish initial pores and form a cross-linked skeleton, and remove volatile components, which can not only improve the electrochemical performance, but also reduce energy consumption.
[0003] According to the sodium storage mechanism of hard carbon materials, the storage of sodium ions in the platform area is closely related to the nanopore structure of hard carbon. Therefore, it is also a common strategy to improve the first coulomb efficiency of the material by regulating the nanopore structure. For the regulation of nanopore structure, we can not only increase the number of pores, but also consider increasing closed pores and reducing open pores to achieve the purpose of storing more sodium ions without reducing the first coulomb efficiency. Common methods for regulating nanopore structure include gas etching (CO 2 or H 2O), template method (ZnO, MnO, KOH), closed porous carbon opening, etc. However, these methods are only a single manufacturing or closed pore structure, and some of them have great restrictions on the selection of raw materials, sometimes toxic substances are used, and the process is complicated, which limits its application. Therefore, it is very important to explore a simple and universal hard carbon nanopore modification process. Summary of the invention
[0004] The purpose of the present invention is to provide a biomass-derived hard carbon negative electrode material, a preparation method and an application thereof, and to manufacture closed nanopores in one step by carbonizing a zinc-containing aromatic compound and a biomass hard carbon material.
[0005] In a first aspect, the present invention provides a method for preparing a biomass-derived hard carbon negative electrode material, comprising the following steps:
[0006] S1: crushing clean and dry biomass materials into powder;
[0007] S2: preliminarily carbonizing the powder under an inert atmosphere;
[0008] S3: placing the powder after preliminary carbonization in a hydrochloric acid solution and an aminosulfonic acid solution, stirring and washing, and then washing with deionized water until neutral, drying, and sieving to obtain biomass carbon powder;
[0009] S4: Grind and mix the biomass carbon powder and the zinc-containing aromatic compound, and carbonize them in three steps under a protective atmosphere to obtain a biomass-derived hard carbon negative electrode material with nano-closed pores.
[0010] Preferably, the biomass material is one of apple branches and bamboo.
[0011] Preferably, the temperature of the preliminary carbonization is 300-700° C., the heating rate is 3-7° C. / min, and the holding time is 1-5 h.
[0012] Preferably, the concentration of the hydrochloric acid solution is 0.1-1.5 mol / L, the concentration of the aminosulfonic acid solution is 0.1-1.5 mol / L, the stirring washing time is 2-5 hours, the temperature is 25-60°C, and the washing is performed until the ash content is ≤0.5%. The aqueous solution of aminosulfonic acid has a complexing ability, can effectively remove dirt such as calcium and magnesium, and is non-volatile, odorless, and has low toxicity to the human body, which can effectively increase the impurity removal effect.
[0013] Preferably, the particle size D of the biomass carbon powder is max ≤20μm.
[0014] Preferably, the zinc-containing aromatic compound includes, but is not limited to, any one of zinc benzoate, zinc benzenesulfonate, zinc p-toluenesulfonate, etc., with zinc benzoate being particularly preferred.
[0015] Preferably, the mass of the zinc-containing aromatic compound accounts for 1%-30% of the mass of the biomass carbon powder, particularly preferably 1%-20%.
[0016] Preferably, the protective atmosphere is argon or nitrogen.
[0017] Preferably, the three-step carbonization treatment refers to: the first step carbonization treatment temperature is 300-600°C, the heating rate is 2-5°C / min, and the insulation time is 2-4h; the second step carbonization treatment temperature is 800-1000°C, the heating rate is 5-10°C / min, and the insulation time is 1-3h; the third step carbonization treatment temperature is 1100-1600°C, the heating rate is 1-5°C / min, and the insulation time is 2-5h.
[0018] Preferably, the pore size of the biomass-derived hard carbon negative electrode material with nano-closed pores ranges from 0.4 nm to 5 nm.
[0019] In a second aspect, the present invention further provides a biomass-derived hard carbon negative electrode material prepared by the method described in the first aspect.
[0020] In a third aspect, the present invention further provides an application of the biomass-derived hard carbon negative electrode material described in the second aspect in a negative electrode material for a sodium ion battery.
[0021] In a fourth aspect, the present invention further provides a negative electrode for a sodium ion battery, comprising the biomass-derived hard carbon negative electrode material described in the second aspect.
[0022] In a fifth aspect, the present invention further provides a sodium ion battery, which uses the negative electrode described in the fourth aspect.
[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0024] The present invention uses hydrochloric acid and aminosulfonic acid solution for pickling in sequence, which improves the impurity removal effect on the basis of protecting the carbon skeleton; uses zinc-containing aromatic compounds to effectively create closed pores in hard carbon materials. This method is not limited by raw materials and has universality. The prepared derivative hard carbon has stable sodium storage performance and good consistency. The zinc-containing aromatic compound can produce different substances at different temperatures to form pores and fill the carbon material. The whole process is carried out in a tubular furnace by sintering, without the need for additional steps and equipment, with a short process, simple process and good practicality. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 The XRD diagrams of Example 1 and Comparative Example 1 are shown.
[0026] Figure 2 This is the HRTEM image of Example 1.
[0027] Figure 3These are the first charge and discharge curves of the biomass carbon material and the hard carbon material prepared in Example 1 and Comparative Example 1.
[0028] Figure 4 These are the charge and discharge cycle performance curves of the biomass carbon material and the hard carbon material prepared in Example 1 and Comparative Example 1. DETAILED DESCRIPTION
[0029] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in further detail.
[0030] The present invention takes advantage of the fact that zinc-containing aromatic compounds decompose into different substances at different temperatures, and can create open pores and fill closed pores in biomass-derived carbon by carbonization alone, and Zn vapor can be condensed and recovered after escaping. In a low-temperature environment, zinc-containing aromatic compounds will pyrolyze to generate ZnO; in a medium-temperature environment, ZnO will react with C to generate metal elements and CO, and this process will etch the carbon material to create open pores. At the same time, Zn will be converted into Zn vapor and escape, which will not only not pollute the material, but also further generate pores; at high temperatures above 1100°C, the decomposition product of zinc-containing aromatic compounds, heterocyclic aromatic hydrocarbons, will be converted into soft carbon to fill the open pores, and at the same time, under the action of high temperature, the open pores are effectively converted into closed pores.
[0031] The present invention provides a method for preparing a biomass-derived hard carbon negative electrode material, the preparation method comprising the following steps:
[0032] (1) Cut the biomass material (e.g., apple branches, bamboo) into small pieces, wash them several times with clean water to remove surface dirt, and dry them in a forced air drying oven at 60°C;
[0033] (2) crushing the dried biomass material block into biomass powder using a crusher;
[0034] (3) placing an appropriate amount of biomass powder in a firing boat and placing it in a tube furnace for preliminary carbonization, heating the mixture to 300-700°C at a heating rate of 3-7°C / min under an inert atmosphere, keeping the temperature for 1-5 hours, and then cooling it naturally to room temperature;
[0035] (4) placing the initially carbonized material in a hydrochloric acid solution and an aminosulfonic acid solution, stirring and washing for 2 to 5 hours at a temperature of 25 to 60° C., then washing with deionized water until neutral, placing it in a vacuum drying oven at 80° C. and drying it thoroughly, and sieving it to obtain biomass carbon powder;
[0036] (5) The dried biomass carbon powder and the zinc-containing aromatic compound are ground and mixed in different mass ratios, and the mixed materials are placed in a tubular furnace and carbonized in three steps under an argon or nitrogen atmosphere. The carbonization conditions are as follows: the first step carbonization treatment temperature is 300-600°C, the heating rate is 2-5°C / min, and the insulation time is 2-4h; the second step carbonization treatment temperature is 800-1000°C, the heating rate is 5-10°C / min, and the insulation time is 1-3h; the third step carbonization treatment temperature is 1100-1600°C, the heating rate is 1-5°C / min, and the insulation time is 2-5h.
[0037] The performance of the biomass-derived hard carbon negative electrode materials prepared in the following embodiments and comparative examples was evaluated by button cells. The electrode slurry was prepared in the following proportions: active material: conductive carbon black: binder CMC: dispersant SBR = 90:4:3:3. Appropriate amounts of ethanol and water were added to prepare the slurry, which was evenly coated on a copper foil. After drying at 100°C for 12 hours, the electrode was cut into pole pieces. The metal sodium sheet was used as the counter electrode, and the electrolyte was 1M NaPF 6 EC / DMC (1:1) solution, glass fiber separator GF / D, assembled into 2032 button cells. -1 The charge and discharge performance was tested under current density and voltage range of 0.001 to 2.5V.
[0038] Example 1
[0039] The method for preparing the biomass-derived hard carbon negative electrode material for a sodium ion battery of this embodiment comprises the following steps:
[0040] (a) The washed, dried and crushed apple branch powder is placed in a tube furnace and heated to 500°C at a heating rate of 5°C / min under an argon atmosphere, and kept at this temperature for 2 hours for preliminary carbonization; the apple branch carbon powder after preliminary carbonization is placed in a 1M hydrochloric acid solution and stirred for 3 hours, and then filtered, and then placed in a 1M aminosulfonic acid solution and stirred for 3 hours, and the temperature during stirring is always 50°C, and then washed with deionized water until neutral, dried, and sieved;
[0041] (b) Take the sieved apple branch carbon powder (D) at a mass ratio of 9.5:0.5 max ≤20μm) and zinc benzoate were fully ground in a mortar, placed in a sintered boat and put into a tube furnace, and carbonized in three steps under an argon atmosphere. The carbonization conditions were as follows: the first step carbonization treatment condition was 600℃, the heating rate was 5℃ / min, and the heat preservation time was 2h; the second step carbonization treatment condition was 900℃, the heating rate was 5℃ / min, and the heat preservation time was 2h; the third step carbonization treatment condition was 1400℃, the heating rate was 5℃ / min, and the heat preservation time was 4h. After cooling, the apple branch derived hard carbon negative electrode material was obtained. Its XRD curve is as follows Figure 1As shown, HRTEM Figure 2 As shown, the first charge and discharge curve and the charge and discharge cycle performance curve are shown as Figure 3 and Figure 4 shown.
[0042] The electrochemical performance results of the biomass-derived hard carbon material prepared in this example are shown in Table 1.
[0043] Example 2
[0044] The other processes are the same as in Example 1, except that in step (b), zinc benzoate is replaced by zinc benzenesulfonate.
[0045] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this example are shown in Table 1.
[0046] Example 3
[0047] The other processes are the same as in Example 1, except that in step (b), zinc benzoate is replaced by zinc p-toluenesulfonate.
[0048] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this example are shown in Table 1.
[0049] Example 4
[0050] The other processes are the same as in Example 1, except that in step (a), the apple branches are replaced with bamboos.
[0051] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this example are shown in Table 1.
[0052] Example 5
[0053] The other processes are the same as in Example 1, except that in step (b), the mass ratio of apple branch carbon powder to zinc benzoate is changed to 4:1.
[0054] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this example are shown in Table 1.
[0055] Example 6
[0056] The other processes are the same as in Example 1, except that in step (b), the temperature of the first carbonization treatment is changed from 600°C to 500°C.
[0057] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this example are shown in Table 1.
[0058] Example 7
[0059] The other processes are the same as in Example 1, except that in step (b), the temperature of the second carbonization treatment is changed from 900°C to 800°C.
[0060] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this example are shown in Table 1.
[0061] Example 8
[0062] The other processes are the same as in Example 1, except that in step (b), the temperature of the third carbonization treatment is changed from 1400°C to 1100°C.
[0063] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this example are shown in Table 1.
[0064] Example 9
[0065] The other processes are the same as in Example 1, except that in step (b), the holding time during the first carbonization treatment is changed from 2 h to 4 h.
[0066] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this example are shown in Table 1.
[0067] Example 10
[0068] The other processes are the same as in Example 1, except that in step (b), the holding time during the second carbonization treatment is changed from 2 h to 3 h.
[0069] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this example are shown in Table 1.
[0070] Embodiment 11
[0071] The other processes are as shown in Example 1, except that in step (b), the holding time is changed from 4 h to 2 h during the second carbonization treatment.
[0072] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this example are shown in Table 1.
[0073] Comparative Example 1
[0074] The other processes are the same as those in Example 1, except that in step (b), no zinc-containing aromatic compound is added, that is, the apple branch carbon powder sieved in step (a) is directly placed in a tube furnace for carbonization in three steps.
[0075] The XRD curve of the biomass-derived hard carbon negative electrode material prepared in this comparative example is as follows Figure 1 As shown, the first charge and discharge curve and the charge and discharge cycle performance curve are shown as Figure 3 and Figure 4 The electrochemical performance results are shown in Table 1.
[0076] Comparative Example 2
[0077] The other processes are the same as those in Example 1, except that: in step (a), the apple branches are replaced with bamboos; in step (b), no zinc-containing aromatic compound is added, that is, the bamboo charcoal powder sieved in step (a) is directly placed in a tubular furnace for carbonization in three steps.
[0078] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this comparative example are shown in Table 1.
[0079] Comparative Example 3
[0080] The other processes are the same as in Example 1, except that in step (a), no aminosulfonic acid solution is used for washing, that is, only 1 M hydrochloric acid solution is used for washing by stirring for 3 hours.
[0081] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this example are shown in Table 1.
[0082] Comparative Example 4
[0083] The other processes are the same as in Example 1, except that in step (b), no three-step carbonization is performed, that is, the temperature is raised to 1400° C. at a heating rate of 5° C. / min and the temperature is kept for 4 h in an argon atmosphere for carbonization.
[0084] The electrochemical performance results of the biomass-derived hard carbon negative electrode material prepared in this comparative example are shown in Table 1.
[0085] Table 1 Performance of biomass-derived hard carbon negative electrode materials prepared in various embodiments and comparative examples
[0086] Discharge specific capacity (mAh / g) Charge capacity (mAh / g) Charge and discharge efficiency % Example 1 365.19 323.44 88.57 Example 2 354.26 310.45 87.63 Example 3 338.25 301.86 89.24 Example 4 347.63 306.45 88.15 Example 5 347.92 303.24 87.16 Example 6 343.84 298.52 86.82 Example 7 329.77 292.16 88.60 Example 8 350.28 308.71 88.13 Example 9 315.88 272.94 86.41 Example 10 329.27 286.72 87.07 Embodiment 11 322.69 260.49 80.72 Comparative Example 1 303.15 223.42 73.70 Comparative Example 2 348.52 283.15 81.24 Comparative Example 3 362.19 296.44 81.84 Comparative Example 4 338.24 266.73 78.86
[0087] It can be seen from the data in Table 1 that the performance of Examples 1, 2, 3, and 5 is improved compared to the blank control Example 1 in which no zinc-containing aromatic compound is added, especially Example 1. This is because the zinc-containing aromatic compound can create closed pores in the biomass carbon during carbonization, thereby improving the sodium storage capacity of the hard carbon negative electrode material and increasing the platform capacity; the performance of Example 4 is effectively improved compared to the blank control Example 2 in which no zinc-containing aromatic compound is added, which shows that the modification method is also applicable to bamboo-based biomass and has certain versatility; the first coulomb efficiency of Example 1 is significantly improved compared to the blank control Example 3 in which no aminosulfonic acid solution is used for washing. This is because the aminosulfonic acid solution not only reacts more gently than stronger acids, but also has the ability to complex metal ions and can effectively remove impurities; the performance of Examples 1, 6, 7, and 8 is effectively enhanced compared to the blank control Example 4 without step-by-step carbonization. This is because the zinc-containing aromatic compounds can be fully converted and reacted during the step-by-step carbonization process, effectively creating pores, and finally closed at high temperatures, while direct one-step carbonization causes the zinc-containing aromatic compounds to be unable to fully function. In addition, different temperatures also have a significant effect on performance; it can be seen from Examples 1, 10, 11, and 12 that different insulation times are also an important factor affecting the electrochemical properties of hard carbon negative electrode materials.
Claims
1. A method for preparing a biomass-derived hard carbon negative electrode material, characterized in that: The steps include: S1: crushing clean and dry biomass materials into powder; S2: preliminarily carbonizing the powder under an inert atmosphere; S3: placing the powder after preliminary carbonization in a hydrochloric acid solution and an aminosulfonic acid solution, stirring and washing, and then washing with deionized water until neutral, drying, and sieving to obtain biomass carbon powder; S4: Grind and mix the biomass carbon powder and the zinc-containing aromatic compound, and carbonize them in three steps under a protective atmosphere to obtain a biomass-derived hard carbon negative electrode material with nano-closed pores.
2. The method according to claim 1, characterized in that The temperature of the initial carbonization is 300-700°C, the heating rate is 3-7°C / min, and the holding time is 1-5h.
3. The method according to claim 1, characterized in that The zinc-containing aromatic compound is selected from any one of zinc benzoate, zinc benzenesulfonate and zinc p-toluenesulfonate, preferably zinc benzoate.
4. The method according to claim 1, characterized in that The mass of the zinc-containing aromatic compound accounts for 1%-30% of the mass of the biomass carbon powder, preferably 1%-20%.
5. The method according to claim 1, characterized in that The three-step carbonization treatment refers to: the first step carbonization treatment temperature is 300-600°C, the heating rate is 2-5°C / min, and the insulation time is 2-4h; the second step carbonization treatment temperature is 800-1000°C, the heating rate is 5-10°C / min, and the insulation time is 1-3h; the third step carbonization treatment temperature is 1100-1600°C, the heating rate is 1-5°C / min, and the insulation time is 2-5h.
6. A biomass-derived hard carbon negative electrode material prepared by the method according to any one of claims 1 to 5.
7. The biomass-derived hard carbon negative electrode material according to claim 6, characterized in that: The pore size of the biomass-derived hard carbon negative electrode material is 0.4nm to 5nm.
8. Use of the biomass-derived hard carbon negative electrode material as claimed in claim 6 or 7 in a negative electrode material for a sodium ion battery.
9. A negative electrode of a sodium ion battery, characterized in that: Comprising the biomass-derived hard carbon negative electrode material as described in claim 6 or 7.
10. A sodium ion battery, characterized in that: The negative electrode as claimed in claim 9 is used.