Covalent organic framework material as well as preparation method and application thereof

Abstract

The invention provides a covalent organic framework material as well as a preparation method and application thereof, and belongs to the technical field of covalent organic framework materials. The method provided by the invention comprises the following steps: mixing 2, 4, 6-triformyl phloroglucinol, multi-element aromatic amine and a polar organic solvent, and sequentially carrying out Schiff base reaction and precipitation to obtain a crude product; the ratio of the volume of the polar organic solvent to the mass of the 2, 4, 6-triformyl phloroglucinol is 300 to 500 mL / g; and sequentially washing and drying the crude product to obtain the covalent organic framework material. The method provided by the invention does not need to be operated under an anhydrous condition, the 2, 4, 6-triformyl phloroglucinol does not need to be completely dissolved in a reaction system, the use amount of an organic solvent can be remarkably reduced, a good reaction effect can be achieved without anhydrous and anaerobic tube sealing, and the method is suitable for large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of covalent organic framework materials, and in particular, to a covalent organic framework material, a preparation method thereof, and an application thereof. Background Art

[0002] Covalent organic framework materials (COFs) have highly ordered pore sizes and adjustable pore structures, and have a wide range of applications in the fields of semiconductors, sensing, adsorption, membrane separation, energy storage, and heterogeneous catalysis. At present, the preparation methods of COFs materials mainly include solvothermal method, ionothermal method, microwave method, and melt synthesis method, etc. Among them, the solvothermal method is the most commonly used method for preparing COFs materials.

[0003] The solvothermal method is to add a mixed solution of a precursor and a mixed solvent into a sealed reactor and react at a certain temperature and pressure. This method has the following problems: First, the solvothermal method for preparing COFs requires anhydrous and anaerobic sealed tube operation, and the equipment requirements are high; Second, the solvothermal reaction requires the precursor to form a solution, and the solubility of many currently used precursors is relatively poor, and a large amount of organic solvents need to be used, which does not meet the requirements of green chemistry; Third, the reaction conditions of the solvothermal method are relatively complex, such as temperature, pressure, solvent type and ratio, acidity, etc. These factors will affect the formation of COFs. If not controlled properly, overreaction is likely to occur, and separation and purification are more difficult, resulting in a decrease in the purity and crystallinity of the product, and the post-treatment steps are complex; Fourth, the reaction time of the solvothermal method is relatively long. For example, when preparing COFs by related prior art, it needs to react for 2 - 9 days at 80 - 120 °C; Fifth, at present, many high-quality COFs can only be carried out on a laboratory scale and it is difficult to achieve large-scale industrial production.

[0004] Therefore, there is an urgent need to provide a preparation method for covalent organic framework materials that is simple in equipment, green, short in reaction time, and suitable for large-scale production. Summary of the Invention

[0005] The purpose of the present invention is to provide a covalent organic framework material, a preparation method thereof, and an application thereof. The method provided by the present invention does not require anhydrous and anaerobic operation, has simple equipment requirements, is green, short in reaction time, and suitable for large-scale production.

[0006] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0007] The present invention provides a preparation method for a covalent organic framework material, comprising the following steps:

[0008] (1) Mix 2,4,6-triformylphloroglucinol, polyaromatic amine and polar organic solvent, and conduct Schiff base reaction and precipitation in sequence to obtain a crude product; the volume ratio of the polar organic solvent to the mass of 2,4,6-triformylphloroglucinol is 300-500 mL / g;

[0009] (2) Wash and dry the crude product obtained in the step (1) in sequence to obtain a covalent organic framework material.

[0010] Preferably, the molar ratio of CHO in 2,4,6-triformylphloroglucinol to NH 2 in the polyaromatic amine in the step (1) is 1:(1-1.2).

[0011] Preferably, the polyaromatic amine in the step (1) includes one or more of diaminoaromatic, triaminoaromatic and tetraaminoaromatic.

[0012] Preferably, the diaminoaromatic includes 4,4'-diaminooctafluorobiphenyl, 3,6-diaminocarbazole, 2,5-diaminopyridine, 6,6'-diamino-2,2'-bipyridine, 3,5-diaminopyridine, 2,4-diaminopyridine, 2,5-diaminobenzonitrile, 4,4'-diaminodiphenyl disulfide, 4,4'-diamino-2,2'-bipyridine, 2,4-diamino-1,3,5-triazine, 4,4'-diamino-[1,1'-biphenyl]-3-carbonitrile, benzidine, m-phenylenediamine, 1,4-benzenedimethanamine, m-xylylenediamine, 2,6-diaminopyridine, 4,4”-diaminoterphenyl, 3,5-diaminobenzotrifluoride, tetramethyl-p-phenylenediamine, dianisidine, 2,5-dimethyl-1,4-phenylenediamine, 2,5-diaminobenzotrifluoride, 3,3',5,5'-tetramethylbenzidine, 2,4,5,6-tetrafluoro-1,3-phenylenediamine, 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl, 4,4”-diaminotetraphenyl, benzo[1,2-D:4,5-D]bithiazole-2,6-diamine, 2.5-bis(4-aminophenyl-1-yl)-1,4-xylene, 3,3'-bis(allyloxy)-[1,1'-biphenyl]-4,4'-diamine, 2,2'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)diaminobiphenyl, 2,2'-dichlorobenzidine, 2,2'-dibromo-4,4'-diaminobiphenyl, melamine, 6,7,9,10,17,18,20,21-octahydrodibenzo[b,k][1,4,7,10,13,16]hexaoxacyclooctadecane-2,13-diamine, methylguanamine or 2-chloro-4,6-diamino-1,3,5-triazine;

[0013] The ternary aromatic amine includes tris(4-aminophenyl)amine, 1,3,5-tris(4-aminophenyl)benzene, 4,4',4''-triaminotriphenylmethane, 1,3,5-tris(4-aminophenoxy)benzene, 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, 5''-(4'-amino-[1,1'-biphenyl]-4-yl)-[1,1':4',1'':3'',1''':4''',1'''-quinquephenyl]-4,4'''-diamine, 5'-(3-aminophenyl)-[1,1':3',1''-terphenyl]-3,3''-diamine, or N4,N4-bis(4'-amino-[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine;

[0014] The quaternary aromatic amine includes 1,3,6,8-tetra-(p-aminophenyl)pyrene, N,N,N',N'-tetrakis(p-aminophenyl)-p-phenylenediamine, 4',5'-bis(4-aminophenyl)-[1,1':2',1''-terphenyl]-4,4''-diamine, or 5',5''-bis(4-aminophenyl)-[1,1':3',1'':3'',1'''-quaterphenyl]-4,4'''-diamine.

[0015] Preferably, the polar organic solvent in the step (1) includes one of 1,4-dioxane, N,N-dimethylformamide, ethylene glycol, n-butanol, isopropanol, ethanol, methanol, and tetrahydrofuran.

[0016] Preferably, the temperature of the Schiff base reaction in the step (1) is 20-150 °C.

[0017] Preferably, the time of the Schiff base reaction in the step (1) is 5-48 h.

[0018] Preferably, the washing reagent in the step (2) includes at least one of N,N-dimethylformamide, tetrahydrofuran, and acetone.

[0019] The present invention also provides a covalent organic framework material prepared by the preparation method described in the above technical solution.

[0020] The present invention also provides an application of the covalent organic framework material described in the above technical solution in a solid electrolyte system.

[0021] The present invention provides a method for preparing a covalent organic framework material, comprising the following steps: mixing phloroglucinol trimethaldehyde, polyaromatic amine and a polar organic solvent, and successively carrying out a Schiff base reaction and precipitation to obtain a crude product; the volume ratio of the polar organic solvent to the mass of phloroglucinol trimethaldehyde is 300-500 mL / g; washing and drying the crude product successively to obtain the covalent organic framework material. Within the scope defined by the present invention, the amount of the polar organic solvent used does not need to completely dissolve phloroglucinol trimethaldehyde, so that phloroglucinol trimethaldehyde dissolved in the polar organic solvent and the polyaromatic amine undergo a Schiff base reaction to form a Schiff base imine structure; due to the presence of OH, the product is more easily converted into a stable keto structure, and the keto structure is difficult to return to the imine structure, so the method provided by the present invention does not need to be operated under anhydrous and anaerobic conditions; after the keto structure is formed, the Schiff base reaction between phloroglucinol trimethaldehyde and the polyaromatic amine supplements the formation of imine. At this time, the phloroglucinol trimethaldehyde dissolved in the polar organic solvent is consumed, and at the same time, more phloroglucinol trimethaldehyde is dissolved in the solvent, forming a dynamic process. Therefore, the method provided by the present invention does not need to completely dissolve phloroglucinol trimethaldehyde in the reaction system, can significantly reduce the usage amount of the organic solvent, and meets the requirements of green chemistry; at the same time, reducing the addition amount of the solvent and forming a stable keto structure as the driving force of the Schiff base reaction can shorten the reaction time, improve the product purity, and can achieve good reaction effects without an anhydrous and anaerobic sealed tube. The equipment requirements are simple and suitable for large-scale production. The results of the examples show that the method provided by the present invention can obtain gram-scale crystal materials in 5-24 h, which is beneficial to promoting the industrialization process of the COFs structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 FIG. is an infrared spectrum diagram of phloroglucinol trimethaldehyde, 4,4'-diaminooctafluorobiphenyl and the prepared COF-8F used in Example 1 of the present invention;

[0023] Figure 2 FIG. is a SEM diagram of the COF-8F prepared in Example 1 of the present invention;

[0024] Figure 3 FIG. is an infrared spectrum diagram of phloroglucinol trimethaldehyde, 1,3,5-tris(4-aminophenyl)benzene and the prepared COF-TAPB used in Example 2 of the present invention;

[0025] Figure 4 FIG. is an infrared spectrum diagram of phloroglucinol trimethaldehyde, N,N,N',N'-tetrakis(p-aminophenyl)-p-phenylenediamine and the prepared COF-PBABD used in Example 3 of the present invention;

[0026] Figure 5 Photographs of the electrolyte sheets prepared in Application Example 1 and Comparative Application Example 1 of the present invention;

[0027] Figure 6 Test results of the electrochemical window of the electrolyte prepared in Application Example 1 of the present invention;

[0028] Figure 7 Test results of the electrochemical window of the electrolyte prepared in Comparative Application Example 1 of the present invention;

[0029] Figure 8 Test results of the ionic conductivity of the electrolytes prepared in Application Example 1 and Comparative Application Example 1 of the present invention;

[0030] Figure 9 Test results of the cyclic stability of the electrolytes prepared in Application Example 1 and Comparative Application Example 1 of the present invention. Detailed implementation manners

[0031] The present invention provides a preparation method of a covalent organic framework material, comprising the following steps:

[0032] (1) Mix 2,4,6-triformylphloroglucinol, polyaromatic amine and a polar organic solvent, and carry out a Schiff base reaction and precipitation in sequence to obtain a crude product; the volume ratio of the polar organic solvent to the mass of 2,4,6-triformylphloroglucinol is 300-500 mL / g;

[0033] (2) Wash and dry the crude product obtained in step (1) in sequence to obtain the covalent organic framework material.

[0034] The present invention mixes 2,4,6-triformylphloroglucinol, polyaromatic amine and a polar organic solvent, and carries out a Schiff base reaction and precipitation in sequence to obtain a crude product.

[0035] In the present invention, the polyaromatic amine preferably includes one or more of a diamine, a triamine and a tetraamine. The present invention uses a diamine, a triamine and a tetraamine as reaction raw materials, and their reaction with 2,4,6-triformylphloroglucinol can regulate the topological structure and crystallinity of the covalent organic framework material, so that the covalent organic framework material has excellent electrochemical performance when used in an electrolyte system.

[0036] In the present invention, the divalent aromatic amine preferably includes 4,4'-diaminooctafluorobiphenyl, 3,6-diaminocarbazole, 2,5-diaminopyridine, 6,6'-diamino-2,2'-bipyridine, 3,5-diaminopyridine, 2,4-diaminopyridine, 2,5-diaminobenzonitrile, 4,4'-diaminodiphenyl disulfide, 4,4'-diamino-2,2'-bipyridine, 2,4-diamino-1,3,5-triazine , 4,4'-diamino-[1,1'-biphenyl]-3-carbonitrile, benzidine, m-phenylenediamine, 1,4-phenylenediamine, m-phenylenediamine, 2,6-diaminopyridine, 4,4"-diamino-p-terphenyl, 3,5-diaminotrifluorotoluene, tetramethyl-p-phenylenediamine, dianisidine, 2,5-dimethyl-1,4-phenylenediamine, 2,5-diaminotrifluorotoluene, 3,3',5,5'-tetramethylbenzidine, 2,4,5 ,6-tetrafluoro-1,3-phenylenediamine, 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl, 4,4"-diaminoquaternaryl, benzo[1,2-D:4,5-D]bithiazole-2,6-diamine, 2.5-bis(4-aminophenyl-1-yl)1,4-xylene, 3,3'-bi(allyloxy)-[1,1'-biphenyl]-4,4'-diamine, 2,2'-difluoro-4,4'-diamino 2,2'-bis(trifluoromethyl)diaminobiphenyl, 2,2'-dichlorobenzidine, 2,2'-dibromo-4,4'-diaminobiphenyl, benzoguanamine, 6,7,9,10,17,18,20,21-octahydrodibenzo[b,k][1,4,7,10,13,16]hexaoxacyclooctadecane-2,13-diamine, methylguanamine or 2-chloro-4,6-diamino-1,3,5-triazine.

[0037] In the present invention, the ternary aromatic amine preferably includes tris(4-aminophenyl)amine, 1,3,5-tris(4-aminophenyl)benzene, 4,4',4"-triaminotriphenylmethane, 1,3,5-tris(4-aminophenoxy)benzene, 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, 5"-(4'-amino-[1,1'-biphenyl]-4-yl)-[1,1':4',1":3",1"':4"',1""-pentaphenyl]-4,4""-diamine, 5'-(3-aminophenyl)-[1,1':3',1"-terphenyl]-3,3"-diamine or N4,N4-bis(4'-amino-[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine.

[0038] In the present invention, the quaternary aromatic amine preferably includes 1,3,6,8-tetra-(p-aminophenyl)-pyrene, N,N,N',N'-tetrakis(p-aminophenyl)-p-phenylenediamine, 4',5'-bis(4-aminophenyl)-[1,1':2',1''-terphenyl]-4,4''-diamine or 5',5''-bis(4-aminophenyl)-[1,1':3',1'':3'',1'''-quaterphenyl]-4,4'''-diamine.

[0039] In the present invention, the CHO in the 2,4,6-triformylphloroglucinol and the NH in the polyaromatic amine 2 The molar ratio of the substances (hereinafter simply referred to as n(CHO):n(NH 2 )) is preferably 1:(1 to 1.2), more preferably 1:(1 to 1.1). In the present invention, by controlling n(CHO):n(NH 2 ) within the above range, the crystallinity and stability of the COFs can be regulated, so that they have excellent electrochemical performance when used in the electrolyte system.

[0040] In the present invention, the polar organic solvent preferably includes one of 1,4-dioxane, N,N-dimethylformamide, ethylene glycol, n-butanol, isopropanol, ethanol, methanol and tetrahydrofuran, and more preferably one of N,N-dimethylformamide, ethylene glycol, n-butanol, isopropanol and ethanol. In the present invention, the above single polar organic solvent is used as the reaction solvent, which has good solubility for 2,4,6-triformylphloroglucinol and polyaromatic amine. After the reaction of 2,4,6-triformylphloroglucinol and polyaromatic amine is consumed, it can continue to dissolve 2,4,6-triformylphloroglucinol, forming a dynamic equilibrium process, reducing the amount of solvent and thus promoting the reaction to quickly reach dynamic equilibrium and accelerating the reaction rate.

[0041] In the present invention, the ratio of the volume of the polar organic solvent to the mass of 2,4,6-triformylphloroglucinol is 300 to 500 mL / g. As an embodiment of the present invention, the ratio of the volume of the polar organic solvent to the mass of 2,4,6-triformylphloroglucinol can be 300 mL / g, 350 mL / g, 400 mL / g, 450 mL / g or 500 mL / g. In the present invention, the ratio of the volume of the polar organic solvent to the mass of 2,4,6-triformylphloroglucinol is controlled within the above range, and the amount of the organic solvent can partially dissolve 2,4,6-triformylphloroglucinol, so that 2,4,6-triformylphloroglucinol dissolved in the solvent participates in the Schiff base reaction to form an imine, and the imine forms a more thermodynamically stable keto structure through a tautomer. This process is an irreversible process. While the imine in the system is converted into a more stable keto structure, the equilibrium of the Schiff base reaction between 2,4,6-triformylphloroglucinol and the polyaromatic amine shifts towards the formation of the imine. While 2,4,6-triformylphloroglucinol is consumed in the system, another part of 2,4,6-triformylphloroglucinol is dissolved in the solvent, forming a continuous dynamic equilibrium process. Reducing the amount of the solvent can promote the reaction to quickly reach the dynamic equilibrium, thereby accelerating the reaction rate.

[0042] In the present invention, the method of mixing 2,4,6-triformylphloroglucinol, the polyaromatic amine and the polar organic solvent is preferably ultrasonic. In the present invention, ultrasonic is used to accelerate the dissolution of 2,4,6-triformylphloroglucinol in the polar organic solvent. In the examples of the present invention, the time of ultrasonic can be 5 min.

[0043] In the present invention, the temperature of the Schiff base reaction is preferably 20 to 150 °C; as an embodiment of the present invention, the temperature of the Schiff base reaction can be 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C or 150 °C; the time of the Schiff base reaction is preferably 5 to 48 h; as an embodiment of the present invention, the time of the Schiff base reaction can be 5 h, 6 h, 8 h, 10 h, 12 h, 15 h, 18 h, 20 h or 24 h. At the above temperature and time in the present invention, it is more beneficial to promote the full reaction of 2,4,6-triformylphloroglucinol and the polyaromatic amine to obtain COFs.

[0044] In the present invention, the method of precipitation is preferably cooling precipitation. In the present invention, the cooling precipitation is preferably to form a precipitate when the system after the Schiff base reaction is cooled to room temperature. In the present invention, cooling is used to precipitate the COFs formed in the system after the Schiff base reaction in the form of a precipitate.

[0045] In the present invention, when no precipitate is formed after the Schiff base reaction system is cooled to room temperature, the present invention preferably adds water to the Schiff base reaction system cooled to room temperature. The present invention promotes the precipitation of COFs in the form of precipitate by adding water. The present invention has no special limitation on the dosage of the water, and it can be adjusted according to needs as long as it can promote the full precipitation of COFs. In the examples of the present invention, the volume ratio of the water to the polar organic solvent can be 10:1.

[0046] The present invention preferably filters the precipitation system to obtain a crude product. The present invention has no special limitation on the operation method of the filtration, and a conventional filtration method can be used as long as the solid obtained by precipitation can be fully separated.

[0047] After obtaining the crude product, the present invention washes and dries the crude product in sequence to obtain a covalent organic framework material.

[0048] In the present invention, the washing reagent preferably includes at least one of N, N-dimethylformamide, tetrahydrofuran and acetone, and more preferably tetrahydrofuran and / or acetone. Since the present invention uses a small amount of polar organic solvent and a stable keto structure as the driving force for the Schiff base reaction, the reaction product has a high purity and few impurities. Therefore, the above reagents are used to wash the crude product, and the impurities can be fully removed without complicated post-treatment operations.

[0049] In the present invention, the drying temperature is preferably 30-100 °C, more preferably 60-80 °C; the drying time is preferably 5-24 h, more preferably 12-24 h. In the present invention, the drying is preferably vacuum drying. In the examples of the present invention, the vacuum degree of the vacuum drying can be 27 MPa. The present invention removes the residual washing reagent in the product COFs by drying.

[0050] Compared with the conventional solvothermal synthesis method carried out in an anhydrous and anaerobic sealed tube, the method provided by the present invention can be prepared in large doses and on a large scale in a flask, and at the same time, it avoids the harsh vacuum conditions in the conventional synthesis method and can be synthesized in any atmosphere. It has the characteristics of simple process conditions, convenient operation and is conducive to large-scale production.

[0051] The present invention also provides a covalent organic framework material prepared by the preparation method described in the above technical solution.

[0052] In the examples of the present invention, the covalent organic framework material preferably has the following structural formula:

[0053]

[0054]

[0055] The covalent organic framework material provided by the present invention has the above structural formula, and has a regular pore structure and stability.

[0056] The present invention also provides an application of the covalent organic framework material described in the above technical solution in a solid electrolyte system.

[0057] The present invention has no special limitation on the method for applying the covalent organic framework material in the electrolyte system, and it can be added to the electrolyte system as an additive.

[0058] Since the covalent organic framework material provided by the present invention has a regular pore structure and stability, it can provide a fast conduction path for charge carriers such as lithium ions, which is beneficial to improving the ionic conductivity of the electrolyte and further improving the electrochemical performance of the electrolyte.

[0059] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the embodiments in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0060] Example 1

[0061] A preparation method of a covalent organic framework material, the steps are as follows:

[0062] (1) Weigh 2,4,6-triformylphloroglucinol (0.210 g, 1 mmol) and 4,4'-diaminooctafluorobiphenyl (0.541 g, 1.65 mmol) in a 500 mL round-bottom flask, add 105 mL of absolute ethanol (the volume ratio of absolute ethanol to the mass of 2,4,6-triformylphloroglucinol is 500 mL / g), ultrasonically treat for 5 min, heat to 50 °C, react for 8 h, cool, and filter to obtain a crude product;

[0063] (2) Wash the crude product obtained in step (1) three times with tetrahydrofuran (10 mL each time), and then wash it three times with acetone (30 mL each time), and place it in a vacuum drying oven (vacuum degree 27 MPa), and dry it at 30 °C for 24 h to obtain a yellow covalent organic framework material, denoted as COF-8F;

[0064] The synthesis route is as follows:

[0065]

[0066] The infrared spectra of 2,4,6-triformylphloroglucinol, 4,4'-diaminooctafluorobiphenyl and the prepared COF-8F used in this example are as Figure 1 shown. From Figure 1It can be seen that the C-H stretching vibration peak of the aldehyde at 2900 cm -1 and the N-H stretching vibration peak corresponding in the range of 3200 - 3500 cm -1 disappear significantly, indicating that the condensation reaction occurs between the aldehyde and the amine. Moreover, the disappearance of the broad O-H stretching vibration peak at 3453 cm -1 and the appearance of a strong C=C double bond stretching vibration peak of ketenimine at 1589 cm -1 confirm the formation of the ketenimine bond in COF-8F.

[0067] The SEM image of the COF-8F prepared in this example is as shown in Figure 2 . It can be seen from Figure 2 that the COF-8F prepared in this example has a regular crystal structure.

[0068] Example 2

[0069] A preparation method of a covalent organic framework material, the steps are as follows:

[0070] (1) Weigh 2,4,6-triformylphloroglucinol (0.210 g, 1 mmol) and 1,3,5-tris(4-aminophenyl)benzene (0.422 g, 1.2 mmol) in a 500 mL round-bottom flask, add 63 mL of N,N-dimethylformamide (the volume ratio of N,N-dimethylformamide to the mass of 2,4,6-triformylphloroglucinol is 300 mL / g), ultrasonicate for 5 min, heat to 150 °C, react for 5 h, cool, pour the reaction solution into 630 mL of water (10 times the amount of DMF), and a solid precipitates. Filter to obtain the crude product;

[0071] (2) Wash the crude product obtained in step (1) three times with N,N-dimethylformamide (5 mL each time), then wash three times with acetone (30 mL each time), place it in a vacuum drying oven (vacuum degree 27 MPa), and dry at 100 °C for 24 h to obtain a yellow covalent organic framework material, denoted as COF-TAPB;

[0072] The synthesis route is as follows:

[0073]

[0074] The infrared spectra of 2,4,6-triformylphloroglucinol, 1,3,5-tris(4-aminophenyl)benzene and the prepared COF-TAPB used in this example are as shown in Figure 3 . It can be seen from Figure 3 that the C-H stretching vibration peak of the aldehyde at 2900 cm -1 and the N-H stretching vibration peak corresponding in the range of 3200 - 3500 cm -1 disappear significantly, indicating that the condensation reaction occurs between the aldehyde and the amine; at 3453 cm-1 The broad hydroxyl stretching vibration peak disappeared, and a strong ketenimine C═C double bond stretching vibration peak appeared at 1579 cm -1 , confirming the formation of the ketenimine bond in COF-TAPB.

[0075] Example 3

[0076] A method for preparing a covalent organic framework material, the steps are as follows:

[0077] (1) Weigh 2,4,6-triformylphloroglucinol (0.210 g, 1 mmol) and N,N,N',N'-tetrakis(p-aminophenyl)-p-phenylenediamine (0.354 g, 0.75 mmol) in a 500 mL round-bottom flask, add 73.5 mL of 1,4-dioxane (the volume ratio of 1,4-dioxane to the mass of 2,4,6-triformylphloroglucinol is 350 mL / g), ultrasonicate for 5 min, stir at room temperature for 24 h, pour the reaction solution into 735 mL of water (10 times the amount of dioxane), and a solid precipitates. Filter to obtain the crude product;

[0078] (2) Wash the crude product obtained in step (1) three times with tetrahydrofuran (10 mL each time), then wash three times with acetone (30 mL each time), and place it in a vacuum drying oven (vacuum degree 27 MPa) and dry at 80 °C for 24 h to obtain a yellow covalent organic framework material, denoted as COF-PBABD;

[0079] The synthesis route is as follows:

[0080]

[0081] The infrared spectra of 2,4,6-triformylphloroglucinol, N,N,N',N'-tetrakis(p-aminophenyl)-p-phenylenediamine and the prepared COF-PBABD used in this example are as Figure 4 shown. It can be seen from Figure 4 that the C-H stretching vibration peak of the aldehyde and the N-H stretching vibration peak corresponding to the range of 3200-3500 cm -1 disappeared significantly, indicating that the condensation reaction occurred between the aldehyde and the amine; the broad hydroxyl stretching vibration peak at 3453 cm -1 disappeared, and a strong broad peak appeared at 1614 cm -1 , which includes the ketenimine C═C double bond stretching vibration peak, confirming the formation of the ketenimine bond in COF-PBABD. -1

[0082] Application Example 1

[0083] A method for preparing an electrolyte material:

[0084] (1) Add 2 g of PVDF-HFP and 20 mL of N,N-dimethylformamide to a 100 mL round-bottom flask, heat to 60 °C and stir for 0.5 h. Add 2 g of lithium bis(trifluoromethanesulfonyl)imide and continue heating and stirring for 0.5 h to mix evenly. Add 0.1 g of COF-8F prepared in Example 1, and obtain a uniform slurry after ultrasonic dispersion;

[0085] (2) Prepare an electrolyte membrane on a glass plate using a coating process and dry it at 150 °C for 24 h.

[0086] (3) Cut the electrolyte membrane into electrolyte sheets. The photo is as shown in Figure 5 the right figure below.

[0087] Assemble the prepared electrolyte material into a battery in the stacking manner of lithium sheet / / solid electrolyte membrane / / positive electrode sheet, and test the performance of the battery.

[0088] Comparative Application Example 1

[0089] A preparation method of an electrolyte material:

[0090] (1) Add 2 g of PVDF-HFP and 20 mL of N,N-dimethylformamide to a 100 mL round-bottom flask, heat to 60 °C and stir for 0.5 h. Add 2 g of lithium bis(trifluoromethanesulfonyl)imide and continue heating and stirring for 0.5 h to mix evenly;

[0091] (2) Prepare an electrolyte membrane on a glass plate using a coating process and dry it at 150 °C for 24 h.

[0092] (3) Cut the electrolyte membrane into electrolyte sheets. The photo is as shown in Figure 5 the left figure below.

[0093] Assemble the prepared electrolyte material into a battery in the stacking manner of lithium sheet / / solid electrolyte membrane / / positive electrode sheet, and test the performance of the battery.

[0094] Test Example 1

[0095] (1) The test results of the electrochemical window of the electrolyte prepared in Application Example 1 are as shown in Figure 6 the figure below, and the test results of the electrolyte prepared in Comparative Application Example 1 are as shown in Figure 7 the figure below. It can be seen from Figure 6 and 7 that for the electrolyte added with COF-8F, its electrochemical window is significantly improved.

[0096] (2) The test results of the ionic conductivity of the electrolytes prepared in Application Example 1 and Comparative Application Example 1 are as shown in Figure 8 the figure below. At Figure 8Among them, 0 represents the test result of the ionic conductivity of the electrolyte prepared in Comparative Application Example 1, and COF0.3 represents the test result of the ionic conductivity of the electrolyte prepared in Application Example 1. From Figure 8 It can be seen that the ionic conductivity of the electrolyte prepared by adding COF-8F is significantly improved.

[0097] (3) The cyclic stability test results of the electrolytes prepared in Application Example 1 and Comparative Application Example 1 are as Figure 9 shown. In Figure 9 Among them, 0 represents the test result of the cyclic stability of the electrolyte prepared in Comparative Application Example 1, and COF0.3 represents the test result of the cyclic stability of the electrolyte prepared in Application Example 1. From Figure 9 It can be seen that the test result of the cyclic stability of the electrolyte prepared by adding COF-8F is significantly improved.

[0098] From the above results, it can be seen that after adding the covalent organic framework material prepared in the present invention, the electrochemical performance of the electrolyte can be significantly improved. This is because the method provided in the present invention uses a polar organic solvent to dissolve part of phloroglucinol trimethaldehyde, and phloroglucinol trimethaldehyde reacts with polyaromatic amines. The particles grow by polycondensation, resulting in an increased particle size; as the generated particles gradually increase, they slowly precipitate, and it is difficult for the keto structure to return to the imine structure, so that it does not need to be operated under anhydrous conditions. By controlling the solubility of the COF structure in different solvents and the feeding ratio, the chain segment length when the COF molecules precipitate from the solution is controlled, and then the molecular weight is adjusted to make it have a regular pore structure. These pores provide a fast conduction path for charge carriers such as lithium ions, which is beneficial to improving the ionic conductivity of the electrolyte.

[0099] In addition, compared with the conventional solvothermal synthesis method carried out in an anhydrous and anaerobic sealed tube, the preparation method provided in the present invention can be prepared in large doses and on a large scale in a flask. At the same time, it avoids the harsh vacuum conditions in the conventional synthesis method and can be synthesized in any atmosphere. It has the characteristics of simple process conditions, convenient operation, and is conducive to large-scale production.

[0100] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a covalent organic framework material, characterized in that: The following steps are involved: (1) mixing 2,4,6-triformylphloroglucinol, a polyvalent aromatic amine and a polar organic solvent, and sequentially performing a Schiff base reaction and precipitation to obtain a crude product; wherein the ratio of the volume of the polar organic solvent to the mass of the 2,4,6-triformylphloroglucinol is 300 to 500 mL / g; (2) The crude product obtained in step (1) is washed and dried in sequence to obtain a covalent organic framework material.

2. The preparation method according to claim 1, characterized in that: In the step (1), the molar ratio of CHO in 2,4,6-triformylphloroglucinol to NH2 in the polyvalent aromatic amine is 1:(1-1.2).

3. The preparation method according to claim 1, characterized in that: The polyvalent aromatic amine in step (1) includes one or more of divalent aromatic amines, trivalent aromatic amines and tetravalent aromatic amines.

4. The preparation method according to claim 3, characterized in that: The divalent aromatic amines include 4,4'-diaminooctafluorobiphenyl, 3,6-diaminocarbazole, 2,5-diaminopyridine, 6,6'-diamino-2,2'-bipyridine, 3,5-diaminopyridine, 2,4-diaminopyridine, 2,5-diaminobenzonitrile, 4,4'-diaminodiphenyl disulfide, 4,4'-diamino-2,2'-bipyridine, 2,4-diamino-1,3,5-triazine, 4,4'- Diamino-[1,1'-biphenyl]-3-carbonitrile, benzidine, m-phenylenediamine, 1,4-phenylenediamine, m-phenylenediamine, 2,6-diaminopyridine, 4,4"-diamino-p-terphenyl, 3,5-diaminotrifluorotoluene, tetramethyl-p-phenylenediamine, dianisidine, 2,5-dimethyl-1,4-phenylenediamine, 2,5-diaminotrifluorotoluene, 3,3',5,5'-tetramethylbenzidine, 2,4,5,6-tetra Fluoro-1,3-phenylenediamine, 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl, 4,4"-diaminoquaternaryl, benzo[1,2-D:4,5-D]bithiazole-2,6-diamine, 2.5-bis(4-aminophenyl-1-yl)1,4-xylene, 3,3'-bi(allyloxy)-[1,1'-biphenyl]-4,4'-diamine, 2,2'-difluoro-4,4'-diaminobiphenyl Benzene, 2,2'-bis(trifluoromethyl)diaminobiphenyl, 2,2'-dichlorobenzidine, 2,2'-dibromo-4,4'-diaminobiphenyl, benzoguanamine, 6,7,9,10,17,18,20,21-octahydrodibenzo[b,k][1,4,7,10,13,16]hexaoxacyclooctadecane-2,13-diamine, methylguanamine or 2-chloro-4,6-diamino-1,3,5-triazine; The ternary aromatic amines include tris(4-aminophenyl)amine, 1,3,5-tris(4-aminophenyl)benzene, 4,4',4"-triaminotriphenylmethane, 1,3,5-tris(4-aminophenoxy)benzene, 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, 5"-(4'-amino-[1,1'-biphenyl]-4-yl)-[1,1':4',1":3",1"':4"',1""-pentaphenyl]-4,4""-diamine, 5'-(3-aminophenyl)-[1,1':3',1"-terphenyl]-3,3"-diamine or N4,N4-bis(4'-amino-[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine; The quaternary aromatic amines include 1,3,6,8-tetrakis-(p-aminophenyl)-pyrene, N,N,N',N'-tetrakis(p-aminophenyl)-p-phenylenediamine, 4',5'-bis(4-aminophenyl)-[1,1':2',1"-triphenyl]-4,4"-diamine or 5',5"-bis(4-aminophenyl)-[1,1':3',1":3",1"'-quadrphenyl]-4,4"'-diamine.

5. The preparation method according to claim 1, characterized in that: The polar organic solvent in step (1) includes one of 1,4-dioxane, N,N-dimethylformamide, ethylene glycol, n-butanol, isopropanol, ethanol, methanol and tetrahydrofuran.

6. The preparation method according to claim 1, characterized in that: The temperature of the Schiff base reaction in step (1) is 20 to 150°C.

7. The preparation method according to claim 1 or 6, characterized in that: The time of the Schiff base reaction in step (1) is 5 to 48 hours.

8. The preparation method according to claim 1, characterized in that: The washing reagent in step (2) includes at least one of N,N-dimethylformamide, tetrahydrofuran and acetone.

9. The covalent organic framework material prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the covalent organic framework material according to claim 9 in a solid electrolyte system.

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