Preparation method of carbon / tin bismuth composite material and application thereof in sodium ion battery
By preparing a carbon/tin-bismuth composite material with a tin-doped transition metal cobalt organic framework cubic structure, the problems of poor cycle stability and low capacity of tin/bismuth anode materials in sodium-ion batteries were solved, achieving high capacity and good cycle performance, making it suitable for industrial applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUANGDONG UNIV OF TECH
- Filing Date
- 2024-07-18
- Publication Date
- 2026-07-21
AI Technical Summary
Tin/bismuth anode materials suffer from poor cycle stability and low capacity of bismuth-based organometallic materials in sodium-ion batteries, which limits their widespread application.
Using cobalt nitrate, tin powder, dimethylimidazole, and bismuth trichloride as raw materials, a carbon/tin-bismuth composite material based on Sn@ZIF-67 was prepared through steps such as static aging, centrifugation, drying, and inert gas sintering. This resulted in a tin-doped transition metal cobalt organic framework cubic structure that provides reversible conversion and electronic conductor properties.
It improves the capacity and cycle stability of sodium-ion battery anode materials, with a capacity retention rate of up to 94.3% after 1300 cycles, overcoming the shortcomings of existing materials and making it suitable for large-scale industrial production.
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Figure CN118919677B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of sodium-ion battery electrode material technology, specifically relating to a method for preparing a carbon / tin-bismuth composite material and its application in sodium-ion batteries. Background Technology
[0002] Rechargeable batteries, with their high energy density, high conversion efficiency, and high flexibility, are currently a hot research topic. The most promising rechargeable batteries are lithium-ion and sodium-ion batteries. Among them, sodium-ion batteries, with their abundant sodium resources and low cost, are expected to become the most promising energy storage device after lithium-ion batteries in the field of large-scale energy storage. A sodium-ion battery is a rechargeable battery that works similarly to a lithium-ion battery, but the lithium in its cathode material is replaced by sodium. This type of battery has potential applications in energy storage systems, electric vehicles, and renewable energy.
[0003] The anode material in sodium-ion batteries primarily serves as the main sodium storage medium, facilitating the insertion and extraction of sodium ions during charge and discharge. Therefore, developing high-performance anode materials is crucial for the commercialization of sodium-ion batteries. Among various anode materials for sodium-ion batteries, alloy anode materials have attracted considerable attention due to their advantages such as high specific capacity and low cost. Tin-based metals, in particular, possess high theoretical specific capacity, abundant reserves, and low operating potential, making them the most promising anode materials for sodium-ion batteries, such as the widely used tin / bismuth anode material. However, tin-based anode materials experience drastic volume changes during charge and discharge, leading to electrode disintegration and gradual loss of electrical contact with the current collector, resulting in poor cycle stability. Furthermore, bismuth-based organometallic materials have low capacity. Therefore, tin / bismuth anode materials are not widely used. Thus, it is necessary to modify tin / bismuth anode materials to promote their application. Summary of the Invention
[0004] To overcome the shortcomings of the prior art, this invention uses cobalt nitrate, tin powder, dimethylimidazole, bismuth trichloride, etc. as raw materials to design and synthesize a bismuth-based metal composite material based on Sn@ZIF-67, namely a carbon / tin-bismuth composite anode material, thereby overcoming the disadvantages of poor cycle stability of tin-based anode materials and low capacity of bismuth-based organometallic materials.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0006] The first aspect of this invention provides a method for preparing a carbon / tin-bismuth composite material, the method comprising the following steps:
[0007] S1. Dissolve cobalt nitrate hexahydrate, tin powder, and polyvinylpyrrolidone in water to obtain a mixed solution;
[0008] S2. After dissolving dimethylimidazole and polyvinylpyrrolidone in water, mix them with the mixed solution from step S1. After static aging, centrifugation and drying, sinter the resulting material in an inert gas to obtain Co-Sn / NC.
[0009] S3. The Co-Sn / NC and bismuth trichloride from step S2 undergo a displacement reaction in dimethyl sulfoxide, followed by filtration and drying to obtain the carbon / tin-bismuth composite material.
[0010] The carbon / tin-bismuth composite material prepared by the method of this invention is a bismuth-based metal composite material based on Sn@ZIF-67, possessing a specific metal-organic framework structure (i.e., ZIF-67). This structure is a composite framework structure composed of tin nanoparticles and a transition metal cobalt-based carbon structure, specifically a tin-doped transition metal cobalt organic framework cubic structure (3D porous structure). This structure not only provides maximum conversion reversibility but also reduces tin expansion. Simultaneously, the 3D porous structure acts as a tin carrier, providing sufficient space for volume fluctuations during sodium ion insertion / extraction processes. Furthermore, ZIF-67 is also a good electronic conductor, enhancing the coulombic efficiency of the battery.
[0011] Preferably, in S1, the molar ratio of cobalt nitrate hexahydrate to tin powder is 1:1-2.
[0012] Preferably, in S2, the molar ratio of cobalt nitrate hexahydrate to dimethylimidazole is 5:70-90.
[0013] Preferably, in S2, the static aging time is 20-30 hours, the number of centrifugations is 3-5 times, the drying temperature is 50-70°C, and the drying time is 10-15 hours.
[0014] Preferably, in S2, the sintering temperature is 700-900℃ and the time is 3-5h.
[0015] Preferably, in S3, the mass ratio of Co-Sn / NC to bismuth trichloride is 100-200:0.2-0.7.
[0016] Preferably, in S3, the displacement reaction is carried out at room temperature for 20-30 hours.
[0017] The second aspect of the present invention provides a carbon / tin-bismuth composite material prepared by the preparation method described in the first aspect.
[0018] The third aspect of the present invention provides the application of the carbon / tin-bismuth composite material described in the second aspect in the preparation of sodium-ion batteries, wherein the carbon / tin-bismuth composite material is used to prepare the negative electrode of the sodium-ion battery.
[0019] The carbon / tin-bismuth composite material prepared by the method of this invention, when used as an anode in sodium-ion batteries, exhibits a significantly improved capacity and excellent cycle stability. After 1300 cycles, the sodium intercalation capacity remains around 350 mAh / g, and the capacity retention rate is still as high as 94.3%. This overcomes the shortcomings of poor cycle stability of tin-based anode materials and low capacity of bismuth-based organometallic materials, and has significant application value.
[0020] Compared with the prior art, the beneficial effects of the present invention are:
[0021] This invention utilizes cobalt nitrate, tin powder, dimethylimidazole, and bismuth trichloride as raw materials, combined with inert atmosphere sintering and displacement reaction techniques, to prepare a bismuth-based metal-organic composite material (carbon / tin-bismuth composite material) based on Sn@ZIF-67. The carbon / tin-bismuth composite material prepared using this method is a tin-doped transition metal cobalt organic framework cubic structure (3D porous structure). This composite structure not only provides maximum conversion reversibility but also reduces tin expansion. The 3D porous structure acts as a tin carrier, providing sufficient space for volume fluctuations during sodium ion insertion / extraction. ZIF-67 is also a good electronic conductor, improving the coulombic efficiency of the battery. Compared to bismuth-based metal-organic framework materials, the carbon / tin-bismuth composite material of this invention not only improves capacity but also exhibits better cycle stability. It can be used as a negative electrode in sodium-ion batteries, overcoming the poor cycle stability of tin-based negative electrode materials and the low capacity of bismuth-based organometallic materials. Furthermore, the method for preparing carbon / tin-bismuth composite materials of the present invention has the advantages of simple preparation process, mild reaction conditions, undemanding equipment requirements, easy operation, low production cost, no pollution, and short time. It can be mass-produced industrially and has broad application prospects. Attached Figure Description
[0022] Figure 1 The image shows a SEM image of the carbon / tin-bismuth composite material prepared in Example 1; the synthesis temperature was 750℃ and the holding time was 3.5 hours.
[0023] Figure 2 The image shows a SEM image of the carbon / tin-bismuth composite material prepared in Example 2; the synthesis temperature was 800℃ and the holding time was 3 hours.
[0024] Figure 3 The image shows an XRD pattern of the carbon / tin-bismuth composite material prepared in Example 1; the synthesis temperature was 750°C and the holding time was 3.5 hours.
[0025] Figure 4 The graph shows the cycling performance of the carbon / tin-bismuth composite material prepared in Example 1 at a current density of 100 mA / g; the synthesis temperature was 750℃ and the holding time was 3.5 hours. Detailed Implementation
[0026] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0027] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.
[0028] Example 1: A method for preparing a carbon / tin-bismuth composite material
[0029] It is prepared through the following steps:
[0030] (1) Dissolve 5 mmol (1.455 g) cobalt nitrate hexahydrate, 5 mmol (0.59355 g) tin powder and 100 mg polyvinylpyrrolidone in 40 mL of water to obtain a mixed solution.
[0031] (2) Dissolve 80 mmol (6.57 g) of dimethylimidazole and 100 mg of polyvinylpyrrolidone in 40 mL of water, then mix and stir with the mixed solution in step (1) for 10 min. After static aging for 24 h, collect the solid product by centrifugation 5 times (10000 rpm) and dry at 60 °C overnight. Then place the material in a nitrogen atmosphere and heat it to 750 °C and keep it at that temperature for 3.5 h. After cooling to room temperature, Co-Sn / NC is obtained.
[0032] (3) Add 100 mg Co-Sn / NC and 2 mmol (0.631 g) bismuth trichloride to 50 mL of dimethyl sulfoxide. After a room temperature displacement reaction (24 h), filter and dry at 60 °C overnight to obtain carbon / tin bismuth composite material.
[0033] from Figure 1 It can be seen that the prepared carbon / tin-bismuth composite material is a tin-doped transition metal cobalt organic framework cubic structure, namely a 3D porous structure based on Sn@ZIF-67. Meanwhile, through... Figure 3 It can be seen that the carbon / tin-bismuth composite material is a composite framework structure composed of tin nanoparticles and a transition metal cobalt-based carbon structure.
[0034] (4) The synthesized carbon / tin-bismuth composite material, conductive carbon black, and binder CMC were mixed in a mass percentage ratio of 70:20:10 to form a slurry, which was then uniformly coated onto copper foil. After drying, it was formed into a circular electrode, which was then assembled with metallic sodium to form a simulated battery. A constant current charge-discharge experiment was conducted, with a charge-discharge current of 100 mA / g and a charge-discharge voltage controlled between 0.01 and 1.5 V. The results showed that the initial sodium intercalation capacity of the prepared carbon / tin-bismuth composite material was 443.1 mAh / g, the second sodium intercalation capacity was 372.5 mAh / g, and the sodium intercalation capacity after 1300 cycles was 351.2 mAh / g, with a capacity retention rate of 94.3% from the second cycle onwards. However, from the second cycle onwards, the sodium intercalation capacity of the carbon / bismuth composite material decreased rapidly with the increase of the number of cycles, decreasing to about 100 mAh / g and remaining unchanged. Figure 4 The preparation method of carbon / bismuth composite material is similar to that of carbon / tin-bismuth composite material, except that tin powder is not added in step (1).
[0035] Example 2: A method for preparing a carbon / tin-bismuth composite material
[0036] It is prepared through the following steps:
[0037] (1) Dissolve 5 mmol (1.455 g) cobalt nitrate hexahydrate, 10 mmol (1.1871 g) tin powder and 100 mg polyvinylpyrrolidone in 40 mL of water to obtain a mixed solution.
[0038] (2) Dissolve 90 mmol (7.389 g) of dimethylimidazolium and 120 mg of polyvinylpyrrolidone in 50 mL of water, then mix and stir with the mixed solution in step (1) for 15 min, then statically age for 24 h, collect the solid product by centrifugation 5 times (10000 rpm), and dry at 80 °C overnight. Then place the material in a nitrogen atmosphere and heat it to 800 °C and keep it at that temperature for 3 h. After cooling to room temperature, Co-Sn / NC is obtained.
[0039] (3) Add 200 mg Co-Sn / NC and 1 mmol (0.3155 g) of bismuth trichloride to 25 mL of dimethyl sulfoxide. After a room temperature displacement reaction (24 h), filter and dry at 80 °C overnight to obtain carbon / tin bismuth composite material.
[0040] The prepared carbon / tin-bismuth composite material is also a tin-doped transition metal cobalt organic framework cubic structure (Sn@ZIF-67 3D porous structure), and is a composite framework structure composed of tin nanoparticles and transition metal cobalt-based carbon structures. Figure 2 ).
[0041] (4) The synthesized carbon / tin-bismuth composite material, conductive carbon black, and binder CMC were mixed in a mass percentage of 70:20:10 to form a slurry, which was then uniformly coated on copper foil. After drying, it was formed into a circular electrode and assembled with metallic sodium to form a simulated battery. Constant current charge-discharge experiments were conducted with a charge-discharge current of 100 mA / g and a charge-discharge voltage controlled between 0.01 and 1.5 V. The results showed that the initial sodium intercalation capacity of the prepared carbon / tin-bismuth composite material was 433.1 mAh / g, the second sodium intercalation capacity was 362.5 mAh / g, and the sodium intercalation capacity after 1300 cycles was 341.2 mAh / g. The capacity retention rate from the second cycle onwards was 94.1%.
[0042] Example 3: A method for preparing a carbon / tin-bismuth composite material
[0043] It is prepared through the following steps:
[0044] (1) Dissolve 5 mmol (1.455 g) cobalt nitrate hexahydrate, 5 mmol (0.59355 g) tin powder and 100 mg polyvinylpyrrolidone in 40 mL of water to obtain a mixed solution.
[0045] (2) Dissolve 70 mmol (5.747 g) of dimethylimidazole and 90 mg of polyvinylpyrrolidone in 45 mL of water, then mix and stir with the mixed solution in step (1) for 10 min. After static aging for 24 h, collect the solid product by centrifugation 5 times (10000 rpm) and dry at 80 °C overnight. Then place the material in a nitrogen atmosphere and heat it to 850 °C and keep it at that temperature for 4 h. After cooling to room temperature, Co-Sn / NC is obtained.
[0046] (3) Add 150 mg Co-Sn / NC and 1.5 mmol (0.4725 g) bismuth trichloride to 35 mL of dimethyl sulfoxide. After a room temperature displacement reaction (24 h), filter and dry at 80 °C overnight to obtain carbon / tin bismuth composite material.
[0047] The carbon / tin-bismuth composite material obtained is also a tin-doped transition metal cobalt organic framework cubic structure (Sn@ZIF-67 3D porous structure), and is a composite framework structure composed of tin nanoparticles and transition metal cobalt-based carbon structure.
[0048] (4) The synthesized carbon / tin-bismuth composite material, conductive carbon black, and binder CMC were mixed in a mass percentage of 70:20:10 to form a slurry, which was then uniformly coated on copper foil. After drying, it was formed into a circular electrode and assembled with metallic sodium to form a simulated battery. Constant current charge-discharge experiments were conducted with a charge-discharge current of 100 mA / g and a charge-discharge voltage controlled between 0.01 and 1.5 V. The results showed that the initial sodium intercalation capacity of the prepared carbon / tin-bismuth composite material was 412.1 mAh / g, the second sodium intercalation capacity was 352.5 mAh / g, and the sodium intercalation capacity after 1300 cycles was 331.2 mAh / g. The capacity retention rate from the second cycle onwards was 93.9%.
[0049] In summary, this invention uses cobalt nitrate, tin powder, dimethylimidazole, bismuth trichloride, and other raw materials to design and synthesize a bismuth-based metal composite material (carbon / tin-bismuth composite material) based on Sn@ZIF-67. This carbon / tin-bismuth composite material not only improves the capacity but also has good cycle stability. It can be used as a negative electrode for sodium-ion batteries to overcome the shortcomings of poor cycle stability of tin-based negative electrode materials and low capacity of bismuth-based organometallic materials, and has broad application prospects.
[0050] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.
Claims
1. The application of a carbon / tin-bismuth composite material in the preparation of sodium-ion batteries, characterized in that, The carbon / tin-bismuth composite material is used to prepare the negative electrode of a sodium-ion battery; The preparation method of the carbon / tin-bismuth composite material includes the following steps: S1. Dissolve cobalt nitrate hexahydrate, tin powder, and polyvinylpyrrolidone in water to obtain a mixed solution; S2. After dissolving dimethylimidazole and polyvinylpyrrolidone in water, mix them with the mixed solution from step S1. After static aging, centrifugation and drying, sinter the resulting material in an inert gas to obtain Co-Sn / NC. S3. The Co-Sn / NC and bismuth trichloride from step S2 undergo a displacement reaction in dimethyl sulfoxide, followed by filtration and drying to obtain the carbon / tin-bismuth composite material. The mass ratio of Co-Sn / NC to bismuth trichloride is 100-200:0.2-0.7, and the displacement reaction is carried out at room temperature for 20-30 hours.
2. The application according to claim 1, characterized in that, In S1, the molar ratio of cobalt nitrate hexahydrate to tin powder is 1:1-2.
3. The application according to claim 1, characterized in that, In S2, the molar ratio of cobalt nitrate hexahydrate to dimethylimidazole is 5:70-90.
4. The application according to claim 1, characterized in that, In S2, the static aging time is 20-30 h, the number of centrifugations is 3-5, the drying temperature is 50-70℃, and the time is 10-15 h.
5. The application according to claim 1, characterized in that, In S2, the sintering temperature is 700-900℃ and the time is 3-5 h.