Bismuth nanoparticle composite material based on multilayer graphdiyne interlayer confinement structure as well as preparation method and application of bismuth nanoparticle composite material

Abstract

The invention discloses a bismuth nanoparticle composite material based on a multilayer graphdiyne interlayer confinement structure and a preparation method and application thereof, and belongs to the technical field of electrochemical energy storage materials. According to the method, a copper substrate is used for catalyzing a precursor to carry out an acetylene-acetylene coupling reaction, then copper is replaced with bismuth, and finally annealing treatment is carried out to further optimize the crystallinity and the interface bonding strength of the material, so that the bismuth nanoparticle composite material with the multilayer graphdiyne interlayer confinement structure is obtained. The material solves the problems of large volume change and fast performance attenuation of the bismuth material in the prior art, and has excellent industrial prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrochemical energy storage materials, and particularly relates to a bismuth nanoparticle composite material based on an interlayer confinement structure of multi-layer graphdiyne, and a preparation method and application thereof. Background Art

[0002] Sodium-ion batteries have become a sustainable alternative to lithium-ion systems, driven by crustal abundance (2.36% for sodium and 0.006% for lithium) and cost-effectiveness. Although SIBs are promising for large-scale energy storage, the development of SIBs is still bottlenecked due to insufficient anode performance, especially the stability-kinetics trade-off of alloy-type materials.

[0003] Sodium-ion batteries are regarded as a potential alternative for large-scale energy storage systems because the crustal abundance of sodium resources (2.36 wt%) is significantly higher than that of lithium (0.002 wt%), and they have a cost advantage. However, their industrialization process is limited by the stability-kinetics performance trade-off problem existing in alloy-type anode materials. Taking metallic bismuth as an example, its theoretical specific capacity is as high as 385 mAh g -1 , and the sodiation potential is moderate (0.3 - 0.6 V vs. Na + / Na), showing ultra-fast reaction kinetics characteristics (fully charge and discharge can be achieved within 7.5 s at a current density of 150 A g -1 ). However, the 244% volume expansion (Bi → Na3Bi phase change) generated during the sodiation process easily causes electrode pulverization failure, and although the traditional carbon coating strategy can alleviate mechanical failure, it will hinder the formation of fast ion transport channels. Summary of the Invention

[0004] Aiming at the above-mentioned prior art, the present invention provides a bismuth nanoparticle composite material based on an interlayer confinement structure of multi-layer graphdiyne, and a preparation method and application thereof, which solve the problems of large volume change and fast performance decay of bismuth materials in the prior art.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: to provide a preparation method of a bismuth nanoparticle composite material based on an interlayer confinement structure of multi-layer graphdiyne, including the following steps: S1: Using a copper substrate to catalyze the alkyne-alkyne coupling reaction of an ethynyl precursor to obtain a multi-layer graphdiyne three-dimensional skeleton structure product; S2: Using an electrochemical replacement reaction to replace copper in the multi-layer graphdiyne three-dimensional skeleton structure product with bismuth to obtain a crude product; S3: Annealing the crude product to obtain a bismuth nanoparticle composite material based on an interlayer confinement structure of multi-layer graphdiyne.

[0006] The beneficial effects of the present invention are as follows: The method provided by the present invention realizes the uniform loading of bismuth nanoparticles in the graphdiyne framework by catalyzing the alkyne-alkyne coupling reaction with a copper substrate and then replacing copper with bismuth. Finally, annealing treatment is carried out to further optimize the crystallinity and interfacial bonding strength of the material, obtaining a bismuth nanoparticle composite material with a multi-layer graphdiyne interlayer confinement structure. The preparation process of this method is simple, and the prepared product has excellent electrical properties and good industrial value.

[0007] On the basis of the above technical solutions, the present invention can be further improved as follows.

[0008] Further, the copper substrate is copper nanoparticles, copper nanowires, copper nanosheets, copper nanorods or copper nanotubes.

[0009] The beneficial effect of adopting the further technical solution is that the morphology and pore structure of the graphdiyne framework can be regulated according to actual needs. When copper substrates with different morphologies catalyze the alkyne-alkyne coupling reaction, a three-dimensional framework with a specific pore distribution can be formed, optimizing the confined distribution of bismuth nanoparticles and enhancing the structural stability and mechanical support ability of the material.

[0010] Further, the ethynyl precursor is hexakis(ethynyl)benzene, 1,3,5-tris(ethynyl)-2,4,6-triazine, 1,3,5-tris(ethynyl)-2,4,6-trifluorobenzene, 1,3,5-tris(ethynyl)-2,4,6-trichlorobenzene or 1,3,5-tris(ethynyl)benzene.

[0011] Further, the process of the alkyne-alkyne coupling reaction is as follows: Add the copper substrate and the ethynyl precursor to a mixed solvent of pyridine and acetone to obtain a mixed solution, and stir the mixed solution at -18°C to 50°C for 24 to 72 hours to prepare a product with a multi-layer graphdiyne three-dimensional framework structure.

[0012] Further, the molar ratio of the copper substrate to the ethynyl precursor is 1:1 to 100, the concentration of the ethynyl precursor in the mixed solution is 0.1 to 100 mg / mL, and the volume ratio of pyridine to acetone in the mixed solvent of pyridine and acetone is 1:1 to 200.

[0013] The beneficial effect of adopting the further technical solution is that the ethynyl precursor is an ethynyl-containing aromatic compound such as hexakis(ethynyl)benzene, and combined with the volume ratio (1:1 to 200) of the pyridine-acetone mixed solvent and the low-temperature reaction conditions, it ensures the efficient progress of the alkyne-alkyne coupling reaction. The synergistic effect of these parameters can precisely regulate the stacking density and crosslinking degree of the graphdiyne layers, forming a three-dimensional network with high conductivity and high specific surface area, providing a fast channel for sodium ion transport.

[0014] Furthermore, the process of electrochemical replacement reaction is as follows: BiI3 and tetrabutylammonium tetrafluoroborate are added to a 1,3-dimethylpropyleneurea solvent to obtain a mixed solution, and then the multi-layered graphdiyne three-dimensional framework structure product is added to the mixed solution, followed by stirring and reacting for 12 to 72 hours to obtain a crude product.

[0015] Furthermore, the concentration of BiI3 in the mixed solution is 0.1 to 10 mol / L, the concentration of tetrabutylammonium tetrafluoroborate is 0.1 to 10 mol / L, and the molar ratio of copper to Bi in the multi-layered graphdiyne three-dimensional framework structure product is 1:1 to 10.

[0016] The beneficial effect of adopting the further technical solution is that the replacement rate and loading amount of bismuth nanoparticles can be controlled, excessive agglomeration of bismuth particles can be avoided, and their uniform distribution between graphdiyne layers can be ensured, thereby effectively suppressing volume expansion and maintaining a high utilization rate of active sites.

[0017] Furthermore, the annealing treatment is carried out at 250 to 350 °C for 1 to 5 hours under argon or a mixed gas of argon and hydrogen with a volume ratio of 95 to 99:1 to 5.

[0018] The beneficial effect of adopting the further technical solution is that the interfacial bonding strength between graphdiyne and bismuth particles is optimized through thermodynamic regulation, internal defects of the material are eliminated, crystallinity is improved, and the electron conduction efficiency and cycle stability are further enhanced.

[0019] The present invention also provides a bismuth nanoparticle composite material based on a multi-layered graphdiyne interlayer confinement structure prepared by the preparation method of the bismuth nanoparticle composite material based on the multi-layered graphdiyne interlayer confinement structure.

[0020] The present invention also provides an application of the bismuth nanoparticle composite material based on the multi-layered graphdiyne interlayer confinement structure in the preparation of electrochemical energy storage devices.

[0021] The beneficial effect of the present invention is that the bismuth nanoparticle composite material based on the multi-layered graphdiyne interlayer confinement structure provided by the present invention has a hierarchical pore structure, which can promote the penetration of the electrolyte. At the same time, the volume expansion stress is buffered by the cavity, and the morphology optimization of the graphdiyne skeleton and the confined distribution of bismuth particles jointly inhibit volume expansion and improve the cycle life. Moreover, the strong electron coupling effect between bismuth particles and graphdiyne effectively reduces the interfacial impedance. When this material is applied to sodium / lithium ion batteries, the highly conductive skeleton and open pores enable the dual fast transport of sodium ions / electrons, supporting second-level charge and discharge under ultra-high current density, and having excellent application potential. Description of the Drawings

[0022] Figure 1 It is the XRD pattern of the bismuth nanoparticle composite material based on the multi-layered graphdiyne interlayer confinement structure in Example 1; Figure 2TEM image of the bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne in Example 1. Detailed implementation manners

[0023] The following combines examples to make a detailed description of the specific implementation manners of the present invention.

[0024] Example 1 A bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne, and its preparation method includes the following steps: S1: Dissolve copper nanoparticles with a particle size of 50 nm and 1,3,5-ethynyl-2,4,6-trifluorobenzene (molar ratio 1:50) in a mixed solution with a volume ratio of pyridine to acetone of 1:10 (the concentration of the precursor is 20 mg / mL), and stir and react at 25 °C for 48 h to obtain a three-dimensional skeleton structure product of multi-layer graphdiyne; S2: Add BiI3 and tetrabutylammonium tetrafluoroborate to the 1,3-dimethylpropyleneurea solvent to obtain a mixed solution, where the concentration of BiI3 is 0.5 mol / L and the concentration of tetrabutylammonium tetrafluoroborate is 0.1 mol / L. Then add the three-dimensional skeleton structure product of multi-layer graphdiyne to the mixed solution (the molar ratio of copper to Bi in the three-dimensional skeleton structure product of multi-layer graphdiyne is 1:2), and stir and react for 24 h to obtain a crude product; S3: Place the crude product in an argon atmosphere and anneal it at 350 °C for 3 h to obtain the bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne.

[0025] Perform XRD analysis on the bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne in this example, and the results are as Figure 1 shown, indicating that the replacement of bismuth nanoparticles is successful.

[0026] Perform TEM analysis on the bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne in this example, and the results are as Figure 2 , the particle size of the bismuth particles in the bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne in this example is 50 nm, the thickness of the graphdiyne layer is 100 nm, and the bismuth particles are confined between the multi-layer graphdiyne layers.

[0027] Prepare a slurry by mixing the bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne, carbon black, and sodium carboxymethylcellulose (CMC) according to a mass ratio of 7:2:1, coat it on a copper foil as the negative electrode, use LiFePO4 as the positive electrode to assemble a full cell, use a glass fiber as the separator, and use a 1M NaPF6 ethylene glycol dimethyl ether solution as the electrolyte to prepare a battery; this battery has a capacity retention rate of 98.3% after cycling 5000 times at a current density of 5A g -1 .

[0028] Example 2 A bismuth nanoparticle composite material based on an interlayer confinement structure of multilayer graphdiyne, and its preparation method includes the following steps: S1: Dissolve copper nanosheets with a thickness of 2 nm and 1,3,5 - ethynyl - 2,4,6 - triazobenzene (molar ratio 1:1) in a mixed solution with a volume ratio of pyridine to acetone of 1:1 (the concentration of the precursor is 0.1 mg / mL), and stir - react at - 18°C for 72 h to obtain a product of a three - dimensional framework structure of multilayer graphdiyne; S2: Add BiI3 and tetrabutylammonium tetrafluoroborate to a 1,3 - dimethylpropyleneurea solvent to obtain a mixed solution, where the concentration of BiI3 is 2 mol / L and the concentration of tetrabutylammonium tetrafluoroborate is 10 mol / L. Then add the product of the three - dimensional framework structure of multilayer graphdiyne to the mixed solution (the molar ratio of copper to Bi in the product of the three - dimensional framework structure of multilayer graphdiyne is 1:1) and stir - react for 12 h to obtain a crude product; S3: Place the crude product in a mixed atmosphere of argon / hydrogen (the volume ratio of argon to hydrogen is 95:5), and anneal at 250°C for 5 h to obtain the bismuth nanoparticle composite material based on the interlayer confinement structure of multilayer graphdiyne.

[0029] After testing, the thickness of the graphdiyne layer of the bismuth nanoparticle composite material based on the interlayer confinement structure of multilayer graphdiyne in this example is 50 nm.

[0030] Prepare a slurry by mixing the bismuth nanoparticle composite material based on the interlayer confinement structure of multilayer graphdiyne, carbon black, and sodium carboxymethylcellulose (CMC) according to a mass ratio of 7:2:1, coat it on a copper foil as the negative electrode, use LiFePO4 as the positive electrode to assemble a full cell, use a glass fiber as the separator, and use a 1M NaPF6 ethylene glycol dimethyl ether solution as the electrolyte to prepare a battery; at room temperature, under a current density of 15 A g -1 , the capacity decay rate of this battery is only 0.015% per cycle after 1000 cycles, and it can maintain a capacity of 203 mAh g -1 at - 40°C, and there is no capacity decay after 500 cycles at 70°C.

[0031] Preferably, add 0.5 wt% carbon nanotubes to the negative electrode slurry formula. After testing, the electrode resistance of the prepared battery is reduced by 42%.

[0032] Example 3 A bismuth nanoparticle composite material based on an interlayer confinement structure of multilayer graphdiyne, and its preparation method includes the following steps: S1: Dissolve copper nanorods with a diameter of 10 nm and hexaethynylbenzene (molar ratio 1:200) in a mixed solution with a volume ratio of pyridine to acetone of 1:200 (the concentration of the precursor is 100 mg / mL), and stir - react at 50°C for 24 h to obtain a product of a three - dimensional framework structure of multilayer graphdiyne; S2: Add BiI3 and tetrabutylammonium tetrafluoroborate into a 1,3-dimethylpropyleneurea solvent to obtain a mixed solution, where the concentration of BiI3 is 10 mol / L and the concentration of tetrabutylammonium tetrafluoroborate is 0.5 mol / L. Then add the multi-layered graphdiyne three-dimensional framework structure product into the mixed solution (the molar ratio of copper to Bi in the multi-layered graphdiyne three-dimensional framework structure product is 1:5), and stir and react for 72 h to obtain a crude product; S3: Place the crude product in a mixed atmosphere of argon / hydrogen (the volume ratio of argon to hydrogen is 99:1), and anneal at 350 °C for 1 h to obtain the bismuth nanoparticle composite based on the multi-layered graphdiyne interlayer confinement structure.

[0033] Prepare a slurry by mixing the bismuth nanoparticle composite based on the multi-layered graphdiyne interlayer confinement structure, carbon black, and sodium carboxymethylcellulose (CMC) according to a mass ratio of 7:2:1, coat it on a copper foil as the negative electrode, use LiFePO4 as the positive electrode to assemble a full cell, use glass fiber as the separator, and use a 1 M NaPF6 ethylene glycol dimethyl ether solution as the electrolyte to prepare a battery; the battery has a discharge capacity retention of 287 mAh g -1 at a current density of 20 A g -1 .

[0034] Example 4 A bismuth nanoparticle composite based on the multi-layered graphdiyne interlayer confinement structure, and its preparation method includes the following steps: S1: Dissolve copper nanowires and 1,3,5-ethynyl-2,4,6-trichlorobenzene (molar ratio 1:50) in a mixed solution with a volume ratio of pyridine to acetone of 1:10 (the concentration of the precursor is 20 mg / mL), and stir and react at 0 °C for 48 h to obtain a multi-layered graphdiyne three-dimensional framework structure product; S2: Add BiI3 and tetrabutylammonium tetrafluoroborate into a 1,3-dimethylpropyleneurea solvent to obtain a mixed solution, where the concentration of BiI3 is 0.5 mol / L and the concentration of tetrabutylammonium tetrafluoroborate is 0.1 mol / L. Then add the multi-layered graphdiyne three-dimensional framework structure product into the mixed solution (the molar ratio of copper to Bi in the multi-layered graphdiyne three-dimensional framework structure product is 1:2), and stir and react for 24 h to obtain a crude product; S3: Place the crude product in a mixed atmosphere of argon and hydrogen, and anneal in segments (the first stage: anneal at 250 °C for 1 h in an argon atmosphere; the second stage: anneal at 300 °C for 2 h in a mixed atmosphere with a volume ratio of argon to hydrogen of 95:5; the third stage: anneal at 350 °C for 1 h in a mixed atmosphere with a volume ratio of argon to hydrogen of 90:10) to obtain the bismuth nanoparticle composite based on the multi-layered graphdiyne interlayer confinement structure.

[0035] After testing, the bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne forms a three-level gradient pore structure.

[0036] A slurry is prepared by mixing the bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne, carbon black, and sodium carboxymethylcellulose (CMC) in a mass ratio of 7:2:1, and coated on a copper foil as the negative electrode. LiFePO4 is used as the positive electrode to assemble a full cell. The separator is glass fiber, and the electrolyte is a 1M NaPF6 solution in ethylene glycol dimethyl ether to prepare the battery. The battery maintains 91.5% of its capacity after 2000 cycles at 2A g -1 -1.

[0037] The same materials are used for a sodium ion full cell (Na3V2(PO4)3 positive electrode), and the discharge capacity reaches 82% of the theoretical value at 50A g -1 -1, and the Coulomb efficiency > 99.9%.

[0038] Example 5 A bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne, and its preparation method includes the following steps: S1: Copper nanotubes and 1,3,5-triethynylbenzene (molar ratio 1:50) are dissolved in a mixed solution with a volume ratio of pyridine to acetone of 1:10 (the concentration of the precursor is 20 mg / mL), and stirred at 4 °C for 48 h to obtain a multi-layer graphdiyne three-dimensional framework structure product; S2: BiI3 and tetrabutylammonium tetrafluoroborate are added to a 1,3-dimethylpropyleneurea solvent to obtain a mixed solution, where the concentration of BiI3 is 0.5 mol / L and the concentration of tetrabutylammonium tetrafluoroborate is 0.1 mol / L. Then, the multi-layer graphdiyne three-dimensional framework structure product is added to the mixed solution (the molar ratio of copper to Bi in the multi-layer graphdiyne three-dimensional framework structure product is 1:2) and stirred for 24 h to obtain a crude product; S3: The crude product is placed in a mixed atmosphere of argon / hydrogen (volume ratio of argon to hydrogen is 98:2), and annealed at 300 °C for 3 h to obtain the bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne.

[0039] A battery is prepared by the same method as in Example 1. Under the condition of pulsed charging (5 seconds) at 150A g -1 -1, 85% charging can be achieved.

[0040] Although the specific implementation manners of the present invention have been described in detail in combination with the embodiments, it should not be construed as a limitation on the protection scope of this patent. Within the scope described in the claims, various modifications and deformations that can be made by those skilled in the art without creative labor still fall within the protection scope of this patent.

Claims

1. A preparation method of a bismuth nanoparticle composite material based on an interlayer confinement structure of multilayer graphdiyne, characterized in that, It includes the following steps: S1: Using a copper substrate to catalyze the alkyne-alkyne coupling reaction of an ethynyl precursor to obtain a product of a multi-layer graphdiyne three-dimensional framework structure; S2: Using an electrochemical replacement reaction to replace the copper in the multi-layer graphdiyne three-dimensional framework structure product with bismuth to obtain a crude product; S3: Annealing the crude product to obtain a bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne.

2. The preparation method of the bismuth nanoparticle composite material based on the interlayer confinement structure of multilayer graphdiyne according to claim 1, characterized in that: The copper substrate is copper nanoparticles, copper nanowires, copper nanosheets, copper nanorods or copper nanotubes.

3. The preparation method of the bismuth nanoparticle composite material based on the interlayer confinement structure of multilayer graphdiyne according to claim 1, wherein: The ethynyl precursor is hexaethynylbenzene, 1,3,5-ethynyl-2,4,6-triazobenzene, 1,3,5-ethynyl-2,4,6-trifluorobenzene, 1,3,5-ethynyl-2,4,6-trichlorobenzene or 1,3,5-ethynylbenzene.

4. The preparation method of the bismuth nanoparticle composite material based on the interlayer confinement structure of multilayer graphdiyne according to claim 1, characterized in that, The process of the alkyne-alkyne coupling reaction is as follows: adding the copper substrate and the ethynyl precursor into a mixed solvent of pyridine and acetone to obtain a mixed solution, and stirring the mixed solution at -18°C to 50°C for 24 to 72 h to obtain a product of a multi-layer graphdiyne three-dimensional framework structure.

5. The preparation method of the bismuth nanoparticle composite material based on the interlayer confinement structure of multilayer graphdiyne according to claim 4, characterized in that: The molar ratio of the copper substrate to the ethynyl precursor is 1:1 to 100, the concentration of the ethynyl precursor in the mixed solution is 0.1 to 100 mg / mL, and the volume ratio of pyridine to acetone in the mixed solvent of pyridine and acetone is 1:1 to 200.

6. The preparation method of the bismuth nanoparticle composite material based on the interlayer confinement structure of multilayer graphdiyne according to claim 1, characterized in that, The process of the electrochemical replacement reaction is as follows: adding BiI3 and tetrabutylammonium tetrafluoroborate into a 1,3-dimethylpropyleneurea solvent to obtain a mixed solution, and then adding the multi-layer graphdiyne three-dimensional framework structure product into the mixed solution and stirring and reacting for 12 to 72 h to obtain a crude product.

7. The preparation method of the bismuth nanoparticle composite material based on the interlayer confinement structure of multilayer graphdiyne according to claim 6, characterized in that: The concentration of BiI3 in the mixed solution is 0.1 to 10 mol / L, the concentration of tetrabutylammonium tetrafluoroborate is 0.1 to 10 mol / L, and the molar ratio of copper to Bi in the multi-layer graphdiyne three-dimensional framework structure product is 1:1 to 10.

8. The preparation method of the bismuth nanoparticle composite material based on the interlayer confinement structure of multilayer graphdiyne according to claim 1, characterized in that: The annealing treatment is carried out at 250 to 350°C for 1 to 5 h under argon or a mixed gas of argon and hydrogen with a volume ratio of 95 to 99:1 to 5.

9. A bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne prepared by the method according to any one of claims 1 to 8.

10. Use of the bismuth nanoparticle composite material based on the interlayer confinement structure of multi-layer graphdiyne according to claim 9 in the preparation of an electrochemical energy storage device.

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