Biomass-based hard carbon negative electrode material and preparation method
Biomass-based hard carbon anode materials were prepared by doping biomass raw materials with waste drugs, which solved the problems of low coulombic efficiency in the first cycle and poor long-cycle stability, and improved the electrochemical performance and resource utilization efficiency of the materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING NADONG NEW ENERGY TECH CO LTD
- Filing Date
- 2024-07-04
- Publication Date
- 2026-06-19
Smart Images
Figure CN118637597B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of sodium-ion battery technology, and in particular to a biomass-based hard carbon anode material and its preparation method. Background Technology
[0002] With the development of new energy vehicles, portable electronic devices, and large-scale energy storage technologies, their demand is increasing daily, which in turn drives up the demand for lithium. Finding alternative or alternative energy storage technologies is currently a technological focus, leading to the development of sodium-ion batteries. Sodium-ion batteries are characterized by low cost, high safety performance, and a wide operating temperature range, making them widely applicable in low-speed electric vehicles, renewable energy access, and 5G communication base stations. Sodium ions have a larger ionic radius than lithium ions, and traditional graphite anodes are incompatible with sodium ions; sodium ions, once embedded, lack electrochemical activity. Research has found that hard carbon, as an anode, is essentially a carbon-based material, similar to graphite (0.335 nm interlayer spacing). However, the twisted carbon layer structure of hard carbon increases the repulsive force between graphitized carbon layers, resulting in a larger interlayer spacing (0.38 nm). This large interlayer spacing and nanopores also facilitate ion diffusion and structural stability during cycling.
[0003] Biomass hard carbon is inexpensive, widely available, and typically retains its precursor morphology during material synthesis. Biomass precursors possess a typical layered porous structure; the layered pore structure retained after carbonization provides defect sites for Na+ ion storage, shortening the solid-phase diffusion distance of Na+ ions, making it an excellent source of hard carbon. However, some issues still require improvement, such as low initial coulombic efficiency and poor long-cycle stability, which severely hinder the application of hard carbon materials in sodium-ion batteries. Summary of the Invention
[0004] To address the aforementioned technical problems, this application provides a biomass-based hard carbon anode material with large reversible capacity, good long-cycle stability, and excellent rate performance without sacrificing initial coulombic efficiency.
[0005] In a first aspect, this application provides a method for preparing a biomass-based hard carbon anode material, comprising the following steps:
[0006] S1. Wash the biomass raw material, and then perform ultrasonic treatment in deionized water and anhydrous ethanol in sequence. Wash, dry, and set aside.
[0007] S2. The biomass raw material processed in step S1 is crushed and sieved to obtain biological precursor powder.
[0008] S3. The biological precursor powder obtained in step S2 is mixed with rabeprazole drug tablet powder at a weight ratio of 7-20:1, then ball-milled and dried to obtain a mixed powder.
[0009] S4. The mixed powder obtained in step S3 is pre-calcined and carbonized under a protective atmosphere to obtain hard carbon material.
[0010] S5. Place the hard carbon material obtained in step S4 in an acid solution and stir to disperse it. Soak for 12-24 hours, then take it out, wash it until neutral, and dry it to obtain the biomass-based hard carbon anode material.
[0011] By adopting the above technical solution, this application synthesizes biomass hard carbon materials by selecting suitable biomass precursors as raw materials. Through the doping of waste pharmaceuticals, more oxygen-containing functional groups are introduced onto the surface of the biomass hard carbon materials, refining the hard carbon layers and constructing more graphite-like spacing conducive to sodium ion insertion / extraction. This improves the reversible capacity, long-cycle stability, and rate performance of the hard carbon materials without sacrificing initial coulombic efficiency, thus meeting the commercialization requirements of lithium / sodium / potassium ion rechargeable batteries. Furthermore, the doping of waste pharmaceuticals not only significantly enhances performance but also enables the resource utilization of waste pharmaceuticals, further reducing production costs and promoting a circular economy and green development.
[0012] Furthermore, in step S1, the biomass raw material is selected from one or more of the following: willow branches, tamarisk branches, sand willow branches, peach branches, crape myrtle branches, camellia branches, cherry blossom branches, and plum branches.
[0013] By employing the above-mentioned technical solution, biomass raw materials such as willow branches, tamarisk branches, sand willow branches, peach branches, crape myrtle branches, camellia branches, cherry blossom branches, and plum branches are sequentially pre-calcined, carbonized, and purified with acid. This process results in hard carbon materials with numerous internal lattice defects, generating a large number of active sites and significantly improving the material's energy density and conductivity. In particular, after sulfur and nitrogen co-doping, it is especially suitable for the preparation of sodium-ion battery negative electrode sheets, improving the migration rate of solvated molecules on the electrode surface and enhancing the electrode's energy density and conductivity.
[0014] Optionally, in step S3, the rabeprazole drug tablet powder is obtained by grinding waste rabeprazole drug tablets.
[0015] Furthermore, the rabeprazole sodium is 2-[[[4-(3-methoxypropoxy)-3-methyl-α-pyridyl]methyl]sulfinyl]-1H-benzimidazole sodium.
[0016] Furthermore, the discarded rabeprazole tablets are selected from discarded rabeprazole enteric-coated tablets.
[0017] Furthermore, the discarded rabeprazole enteric-coated tablets comprise the following components in parts by weight: 5-15 parts rabeprazole sodium, 50-80 parts mannitol, 1-2.5 parts betaine, 5-12 parts light magnesium oxide, 25-40 parts low-substituted hydroxypropyl cellulose, 0.5-1 part pullulan, 4-5.5 parts calcium hydroxide, 10-20 parts talc, and 0.5-3 parts sodium stearate fumarate.
[0018] By adopting the above technical solution, waste rabeprazole drug tablet powder is doped onto the basis of biological precursor powder. Under the combined effect of the benzimidazole group, the active ingredient in the waste rabeprazole drug tablet powder, other excipients, and the properties of the biological precursor powder itself, more carbonyl groups (C=O) are retained or introduced during the subsequent carbonization process to form hard carbon material. This provides more active sites for reversible sodium ion adsorption, thereby increasing the slope zone capacity. In addition, the interlayer spacing of the waste drug-doped biomass hard carbon is improved, the number of hard carbon layers is increased, and sodium ion insertion and extraction are easier. Compared with traditional biomass hard carbon, the rate performance and cycle stability are greatly improved.
[0019] Furthermore, in step S3, the D50 particle size of the mixed powder is 3-30 μm.
[0020] By controlling the particle size to be similar, the waste rabeprazole drug tablet powder is fully dispersed in the biological precursor powder, thereby making the carbonyl group distribution in the prepared biomass-based hard carbon anode material more uniform, which in turn makes the charge distribution in the biomass-based hard carbon anode material uniform and improves the cycle stability of sodium-ion batteries.
[0021] Furthermore, in step S4, the pre-firing temperature is 300-400℃ and the pre-firing time is 1.5-2.5h; the carbonization temperature is 1000-1600℃ and the carbonization time is 1-9h.
[0022] Furthermore, in step S5, the acid solution is a 1-4 mol / L hydrochloric acid or nitric acid solution.
[0023] By adopting the above technical solution, the carbonized mixed powder is soaked in acid solution to remove impurities from the material. More importantly, it activates the hard carbon of the bio-based material after carbonization, which can improve its conductivity, increase the number of defects, promote electron transport, and facilitate the adsorption and intercalation of more sodium ions.
[0024] Secondly, this application provides a biomass-based hard carbon anode material prepared by the above-mentioned method for preparing biomass-based hard carbon anode material.
[0025] In summary, the present invention has at least one of the following beneficial technical effects:
[0026] 1. The biomass-based hard carbon anode material used in this application is made from widely available and inexpensive raw materials. Its natural porous structure and irregular layered structure are conducive to accelerating electrolyte penetration, making it more suitable for use in secondary ion battery anode materials.
[0027] 2. The use of medical waste drugs in this application to prepare biomass-based hard carbon anode materials solves the problem of post-processing and reuse of medical waste rabeprazole tablets. On the other hand, the use of waste drugs to dope introduces more hydroxyl groups (C=O), providing more active sites for reversible sodium ion adsorption. The hard carbon materials prepared have significantly improved rate performance and cycle stability compared with traditional biomass hard carbon. Attached Figure Description
[0028] Figure 1 XPS image of the biomass-based hard carbon anode material prepared in Example 1;
[0029] Figure 2 SEM image of the biomass-based hard carbon anode material prepared in Example 1;
[0030] Figure 3 The first charge-discharge curve of the coin cell prepared from the biomass-based hard carbon anode material prepared in Example 1 in the voltage range of 0.01-3.0V is shown.
[0031] Figure 4 The image shows the long-cycle performance of a coin cell made from the biomass-based hard carbon anode material prepared in Example 1 in the voltage range of 0.01-3.0V.
[0032] Figure 5 The first charge-discharge curve of the coin cell prepared from the biomass-based hard carbon anode material prepared in Example 2 in the voltage range of 0.01-3.0V is shown.
[0033] Figure 6 XPS image of the biomass-based hard carbon anode material prepared in Comparative Example 1;
[0034] Figure 7 SEM image of the biomass-based hard carbon anode material prepared in Comparative Example 1;
[0035] Figure 8 The first charge-discharge curves of the coin cell made from the biomass-based hard carbon anode material prepared in Comparative Example 1 in the voltage range of 0.01-3.0V are shown.
[0036] Figure 9 This is a long-cycle graph of a coin cell made from the biomass-based hard carbon anode material prepared in Comparative Example 1 in the voltage range of 0.01-3.0V. Detailed Implementation
[0037] This application designs a method for preparing biomass-based hard carbon anode materials, including the following steps:
[0038] S1. Wash the biomass raw material, and then perform ultrasonic treatment in deionized water and anhydrous ethanol in sequence. Wash, dry, and set aside.
[0039] S2. The biomass raw material processed in step S1 is crushed and sieved to obtain biological precursor powder.
[0040] S3. The biological precursor powder obtained in step S2 is mixed with rabeprazole drug tablet powder at a weight ratio of 7-20:1, then ball-milled and dried to obtain a mixed powder.
[0041] S4. The mixed powder obtained in step S3 is pre-calcined and carbonized under a protective atmosphere to obtain hard carbon material.
[0042] S5. Place the hard carbon material obtained in step S4 in an acid solution and stir to disperse it. Soak for 12-24 hours, then take it out, wash it until neutral, and dry it to obtain the biomass-based hard carbon anode material.
[0043] The technical problem addressed in this application is that existing biomass hard carbon anode materials suffer from several issues requiring improvement, such as low initial coulombic efficiency and poor long-cycle stability, which severely hinder the application of hard carbon materials in sodium-ion batteries. This application utilizes medical waste drugs to prepare biomass-based hard carbon anode materials. This solves the problem of post-processing and reuse of medical waste rabeprazole tablets. Furthermore, the doping of waste drugs introduces more hydroxyl groups (C=O), providing more active sites for reversible sodium ion adsorption. The resulting hard carbon material exhibits significantly improved rate performance and cycle stability compared to traditional biomass hard carbon materials.
[0044] The present application will be further described in detail below with reference to the accompanying drawings and embodiments.
[0045] Example 1
[0046] The preparation method of the biomass-based hard carbon anode material in Example 1 includes the following steps:
[0047] S1. Wash 5g of peach branches, soak them in deionized water, and sonicate for 5 hours; then soak them in anhydrous ethanol, sonicate for 5 hours, wash them, and dry them at 80℃ for 12 hours.
[0048] S2. The peach branches processed in step S1 are crushed and sieved to obtain biological precursor powder.
[0049] S3. The biological precursor powder obtained in step S2 is mixed with rabeprazole drug tablet powder at a weight ratio of 7:1, ball-milled for 30 min, and dried at 80°C for 10 min to obtain the mixed powder.
[0050] S4. The mixed powder obtained in step S3 is pre-calcined at 300°C for 2 hours under an argon atmosphere, and then carbonized at 1400°C for 2 hours to obtain hard carbon material.
[0051] S5. The hard carbon material obtained in step S4 is soaked in 2 mol / L hydrochloric acid solution and stirred and dispersed for 16 h. Then it is taken out, washed with deionized water until neutral, and dried at 80 °C for 12 h to obtain biomass-based hard carbon anode material.
[0052] The rabeprazole tablet powder used in Example 1 was prepared by grinding waste rabeprazole tablets. The waste rabeprazole tablets used were expired rabeprazole enteric-coated tablets, which were uncoated rabeprazole enteric-coated tablets that had expired for more than six months and were purchased from Shuanghe Pharmaceutical Co., Ltd.
[0053] The uncoated rabeprazole enteric-coated tablets contain the following components in parts by weight: 10 parts rabeprazole sodium, 60 parts mannitol, 1.5 parts betaine, 10 parts light magnesium oxide, 32 parts low-substituted hydroxypropyl cellulose, 0.5 parts pullulan, 5 parts calcium hydroxide, 12 parts talc, and 2 parts sodium stearate fumarate.
[0054] Example 2
[0055] Example 2 is based on Example 1, except that in step S3 of Example 2, the weight ratio of biological precursor powder to rabeprazole drug tablet powder is changed to 20:1.
[0056] Example 3
[0057] Example 3 is based on Example 1, except that in step S1 of Example 3, the peach branches are replaced with willow branches of equal weight.
[0058] Example 4
[0059] Example 4 is based on Example 1, except that in step S1 of Example 3, the peach branches are replaced with camellia branches of equal weight.
[0060] Comparative Example 1
[0061] Comparative Example 1 is based on Example 1, except that: in step S3 of Comparative Example 1, rabeprazole drug tablet powder is not used to dope the biological precursor powder; the preparation method of the biomass-based hard carbon anode material in Comparative Example 1 includes the following steps:
[0062] S1. Wash 5g of peach branches, soak them in deionized water, and sonicate for 5 hours; then soak them in anhydrous ethanol, sonicate for 5 hours, wash them, and dry them at 80℃ for 12 hours.
[0063] S2. The peach branches processed in step S1 are crushed and sieved to obtain biological precursor powder.
[0064] S3. The biological precursor powder obtained in step S2 is pre-calcined at 300°C for 2 hours under an argon atmosphere, and then carbonized at 1400°C for 2 hours to obtain hard carbon material.
[0065] S4. The hard carbon material obtained in step S3 is soaked in 2 mol / L hydrochloric acid solution and stirred and dispersed for 16 h. Then it is taken out, washed with deionized water until neutral, and dried at 80 °C for 12 h to obtain biomass-based hard carbon anode material.
[0066] Performance testing
[0067] The performance of the biomass-based hard carbon anode materials prepared in Examples 1-4 and Comparative Example 1 of this application was tested using a half-cell test method. The biomass-based hard carbon anode materials prepared in Examples 1-4 and Comparative Example 1 were used as the positive electrodes of the batteries, and several metal sodium sheets of the same specifications were used as the counter electrodes. Commercially available sodium ion electrolytes were used, and GF / D separators were selected. The batteries were assembled into coin cells (forming sodium ion batteries) under an argon atmosphere, and the electrochemical performance was tested under a voltage range of 0.01-3.0V.
[0068] Table 1 shows the 0.1C first reversible capacity, first coulombic efficiency, and 5C specific capacity of the coin cells made from the biomass-based hard carbon anode materials in Examples 1-4 and Comparative Example 1.
[0069] Table 1
[0070]
[0071] Analysis of the data in Table 1 shows that the biomass-based hard carbon anode material prepared using the method described in this invention exhibits excellent initial reversible capacity and rate performance in sodium-ion batteries. Specifically, the initial reversible capacity at 0.1C reaches 318 mAh / g, and the specific capacity at 5C reaches 235 mAh / g. Combined with... Figure 3 As can be seen, the sodium-ion battery made from the biomass-based hard carbon anode material prepared in Example 1 achieved an initial discharge specific capacity of 318 mAh / g and a first-cycle coulombic efficiency of 91.68%. Combined with... Figure 4 The biomass-based hard carbon material prepared by this invention exhibits excellent rate performance, maintaining a reversible specific capacity of 235 mAh / g even at a high rate of 5C. The data from Example 1 and Comparative Example 1 are compared and combined... Figure 9It was found that Comparative Example 1 had an initial reversible capacity of 278 mAh / g and an initial coulombic efficiency of 85.37%; however, its specific capacity at a high rate of 5C was only 187 mAh / g. Therefore, this invention, by adding waste rabeprazole drug tablet powder to a biomass precursor and then sintering it, significantly improved the initial reversible capacity and rate performance of the biomass-based hard carbon anode material after high-temperature carbonization, while still maintaining a high initial coulombic efficiency. This indicates that this approach reduces the impedance of sodium ion diffusion in the hard carbon anode, thus improving its electrochemical performance.
[0072] Figure 1 and Figure 6 XPS elemental diagrams of the biomass-based hard carbon materials prepared in Example 1 and Comparative Example 1 of this invention are shown below. Figure 1 and Figure 6 Comparison shows that drug doping increases the proportion of carbonyl groups (C=O) in hard carbon materials. C=O+Na++e-→CO-Na increases the active sites for sodium ion storage, thus increasing the capacity and improving electrochemical performance.
[0073] Figure 2 and Figure 7 The SEM images of the biomass-based hard carbon materials prepared in Example 1 and Comparative Example 1 of this invention are shown in the figures. It can be seen that after adding waste rabeprazole drug tablet powder as a dopant, the hard carbon particles are refined and the number of hard carbon layers is increased, which increases the active sites of sodium ions and makes sodium ion insertion easier, thus improving the electrochemical performance of the material.
[0074] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A method for preparing a biomass-based hard carbon negative electrode material, characterized in that, Includes the following steps: S1. The biomass raw material is washed, and then subjected to ultrasonic treatment in deionized water and anhydrous ethanol in sequence. After washing and drying, it is ready for use. The biomass raw material is selected from one or more of the following: willow branches, red willow branches, sand willow branches, peach branches, crape myrtle branches, camellia branches, cherry blossom branches, and plum branches. S2. The biomass raw material processed in step S1 is crushed and sieved to obtain biological precursor powder. S3. The biological precursor powder obtained in step S2 is mixed with rabeprazole drug tablet powder at a weight ratio of 7-20:1, then ball-milled and dried to obtain a mixed powder. S4. The mixed powder obtained in step S3 is pre-calcined and carbonized under a protective atmosphere to obtain hard carbon material. S5. Place the hard carbon material obtained in step S4 in an acid solution and stir to disperse it. Soak for 12-24 hours, then take it out, wash it until neutral, and dry it to obtain the biomass-based hard carbon anode material.
2. The method for preparing biomass-based hard carbon anode material according to claim 1, characterized in that, In step S3, the rabeprazole drug tablet powder is obtained by grinding waste rabeprazole drug tablets.
3. The method for preparing biomass-based hard carbon anode material according to claim 2, characterized in that, The discarded rabeprazole tablets were selected from discarded rabeprazole enteric-coated tablets.
4. The method for preparing the biomass-based hard carbon anode material according to claim 3, characterized in that, The discarded rabeprazole enteric-coated tablets comprise the following components in parts by weight: 5-15 parts rabeprazole sodium, 50-80 parts mannitol, 1-2.5 parts betaine, 5-12 parts light magnesium oxide, 25-40 parts low-substituted hydroxypropyl cellulose, 0.5-1 part pullulan, 4-5.5 parts calcium hydroxide, 10-20 parts talc, and 0.5-3 parts sodium stearate fumarate.
5. The method for preparing biomass-based hard carbon anode material according to claim 1, characterized in that, In step S3, the D50 particle size of the mixed powder is 3-30 μm.
6. The method for preparing biomass-based hard carbon anode material according to claim 1, characterized in that, In step S4, the pre-firing temperature is 300-400℃ and the pre-firing time is 1.5-2.5h; the carbonization temperature is 1000-1600℃ and the carbonization time is 1-9h.
7. The method for preparing biomass-based hard carbon anode material according to claim 1, characterized in that, In step S5, the acid solution is a 1-4 mol / L hydrochloric acid or nitric acid solution.
8. A biomass-based hard carbon anode material prepared by the preparation method of the biomass-based hard carbon anode material according to any one of claims 1-7.