A covalent organic framework material based on polybenzimidazoles, preparation method and application thereof

Abstract

The present invention belongs to the field of electrode material preparation, and specifically relates to a covalent organic framework material based on polybenzimidazoles, its preparation method and application. The material is prepared by hydrothermal synthesis of hexaazanaphthylic acid HAT‑COOH and diaminobenzidine BPTA. The preparation method of the above material comprises mixing hexaazanaphthylic acid and diaminobenzidine in a certain molar ratio, dissolving in water, undergoing hydrothermal reaction, filtering, and washing to obtain a polybenzimidazole covalent organic framework material HATBPTA. This new material exhibits good electrochemical performance in an aqueous zinc ion battery system. The method of the present invention is simple in process, is conducive to large-scale industrial preparation, and promotes the development of the industrialization of cheap, efficient, and environmentally friendly aqueous zinc ion batteries.

Description

Technical Field

[0001] The present invention belongs to the field of electrode material preparation, and specifically relates to a covalent organic framework material based on polybenzimidazoles, a preparation method and an application thereof. Background Art

[0002] Since the beginning of the 21st century, science and industry have rapidly advanced worldwide, leading to a growing demand for energy. The development of renewable clean energy sources, such as wind, hydrogen, and solar, has become an inevitable requirement for human progress. However, these renewable energy sources lack sustainable and stable access or are difficult to transport, hindering their large-scale application. Using energy storage devices to store, convert, and integrate these renewable energy sources into the national power grid is a key solution to this problem.

[0003] Aqueous zinc-ion batteries are considered to be large-scale energy storage devices with good development prospects due to their low cost, eco-friendliness, and high safety. Metallic zinc has a large theoretical specific capacity (820 mAh g -1 ) and a low redox potential (-0.76V). Therefore, aqueous zinc-ion batteries are expected to achieve higher energy density. The most commonly used electrode materials for zinc-ion batteries are inorganic electrode materials. However, most inorganic materials contain transition metals, which are resource-scarce, difficult to prepare, and environmentally unfriendly, making them difficult to recycle and reuse. Therefore, scientists have turned their attention to green and environmentally friendly organic electrode materials.

[0004] Organic materials have the characteristics of high specific energy, designability, economy and environmental friendliness, which give them many advantages in the application of battery electrode materials. When metal ions are inserted and removed from organic molecular materials, the molecular structure tends to be stable, and there is no restriction on the type of metal ions, which is very beneficial for the cycle stability of the battery over a long period of time. Organic electrode materials usually adopt electron-deficient systems, and common functional groups include carbon-nitrogen double bonds and carbon-oxygen double bonds. The structure of organic materials can also be precisely molecularly designed, which is very important for improving the performance of rechargeable aqueous zinc-ion batteries. Therefore, the design and development of organic electrode materials with multiple active sites and structural diversity is crucial for the construction of energy storage devices with high capacity, long cycle life and high energy density. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing a novel covalent organic framework material that can be used as an electrode material for zinc ion batteries.

[0006] The above technical problem is achieved by the following technical solution: a covalent organic framework material based on polybenzimidazole, characterized in that the covalent organic framework material is HATBPTA, with a structure as shown in formula (I):

[0007]

[0008] The above-mentioned method for preparing a covalent organic framework material based on polybenzimidazoles comprises the following steps: dissolving hexaazine naphthylic acid and 3,3'-diaminobenzidine in water, adding a certain amount of catalyst, placing the mixture in a reactor for reaction, filtering, washing, and drying to obtain a brown-black product HATBPTA;

[0009] The structural formula of hexaazine naphthylic acid is as follows:

[0010]

[0011] The structural formula of 3,3'-diaminobenzidine is as follows:

[0012]

[0013] In the above preparation method, the catalyst is 3M acetic acid solution.

[0014] In the above preparation method, the molar ratio of hexaazine carboxylic acid to 3,3'-diaminobenzidine is 1:1.5.

[0015] In the above preparation method, the reaction is carried out at 180° C. for three days.

[0016] In the above preparation method, the drying step is drying at 60° C. for 12 h.

[0017] The above-mentioned application of a covalent organic framework material based on polybenzimidazole as an electrode material for aqueous zinc ion batteries.

[0018] The above application method is as follows:

[0019] 1) The current collector titanium foil is made into an electrode sheet;

[0020] 2) Grinding the above-mentioned covalent organic framework material, Super P, and polyvinylidene fluoride according to a certain mass ratio, adding solvent NMP to grind into a uniform and non-granular slurry, and evenly coating it on the electrode sheet;

[0021] 3) Place the coated electrode sheet in a vacuum drying oven at 60°C for 12 hours to remove the residual solvent, weigh it, and calculate the loading;

[0022] 4) Battery assembly: Using the 2032 button cell standard, place the zinc sheet, separator, electrolyte, electrode sheet obtained in step 3), gasket, spring, and positive electrode shell in the negative electrode shell in sequence, and then encapsulate them using a packaging machine to obtain an aqueous zinc ion 2032 button cell.

[0023] In the above application, in step 2), the mass ratio of the covalent organic framework material, Super P, and polyvinylidene fluoride is 6:3:1.

[0024] In the above application, in step 4), the concentration of the electrolyte is 1M Zn(CF3SO3)2 aqueous solution, and the volume is 120 μL.

[0025] Beneficial effects of the present invention:

[0026] 1. The HATBPTA synthesized in the present invention exhibits a high capacity as an electrode material for zinc ion batteries. -1 At a current density of 83 mAh g -1 discharge capacity.

[0027] 2. HATBPTA as an electrode material for zinc ion batteries can absorb Zn 2+ , and can adsorb H + , precisely because H + The embedding of α-HATBPTA gives it a high specific capacity.

[0028] 3. The HATBPTA material of the present invention is easy to synthesize, uses water as a solvent, is environmentally friendly, green and efficient, and can be used for large-scale preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the SEM image of HATBPTA.

[0030] Figure 2 This is the FTIR spectrum of HATBPTA.

[0031] Figure 3 HATBPTA is an electrode material for zinc ion batteries at a scan rate of 1 mV·S -1 The cyclic voltammetry curve below.

[0032] Figure 4 HATBPTA is an electrode material for zinc ion batteries at a current density of 100 mA g -1 The charge and discharge curves of the first three cycles are shown below. DETAILED DESCRIPTION

[0033] Experimental Example 1 Preparation of covalent organic framework materials based on polybenzimidazole

[0034] Compound 1 (199.66 mg, 0.2 mmol) and compound 2 (264.28 mg, 0.3 mmol) were ground and mixed uniformly, then dispersed in 30 mL of ultrapure water. 1 mL of 3M acetic acid solution was then added dropwise as a catalyst. After ultrasonic dispersion for 15 minutes, the mixture was transferred to a 50 mL polytetrafluoroethylene-lined container and placed in a reactor. The mixture was then reacted in an oven at 180°C for 3 days. After cooling to room temperature, the product was filtered out using a sand core filter and washed three times with 20 mL of ultrapure water and 20 mL of acetone, respectively. The resulting brown-black product, HATBPTA, was then dried in a vacuum drying oven at 60°C for 12 hours to obtain the covalent organic framework material, HATBPTA. Compound 1 is hexaazinapyridine carboxylic acid, and compound 2 is 3,3'-diaminobenzidine. The specific synthesis route is as follows:

[0035]

[0036] Figure 1 This is the SEM image of HATBPTA, which shows that the microstructure of HATBPTA is a layered structure. Figure 2 This is the FTIR spectrum of HATBPTA. -1 Corresponding to the distortion vibration and resonance vibration of the aromatic C=N bond, 1590cm -1 Corresponding to the common resonance vibration of the imidazole C=N bond, 1611 cm -1 Corresponding to the stretching vibration of the C=O bond in the amide, 1358 cm -1 The FTIR spectrum shows that HATBPTA has an aromatic hydrocarbon configuration and an amide structure, in which the unsaturated C=N and C=O bonds provide active sites for reversible insertion and removal of zinc ions.

[0037] Experimental Example 2 Preparation of electrode sheets

[0038] After HATBPTA, Super P, and PVDF are evenly ground in a mass ratio of 6:3:1, the solvent NMP is added to grind into a uniform and non-granular slurry, and the slurry is evenly coated on the current collector titanium foil. The coated titanium foil is placed in a vacuum drying oven at 60°C and dried for 12 hours to obtain an electrode sheet.

[0039] Experimental Example 3: Assembling a battery

[0040] Using the 2032 button battery standard, a round zinc sheet with a diameter of 12 mm and a glass fiber separator were placed in the negative electrode shell in sequence, 120 μL of 1 M Zn(CF3SO3)2 electrolyte was added dropwise to ensure that the electrolyte moistened the separator, and then the electrode sheet, gasket, spring, and positive electrode shell obtained in Example 2 were placed in sequence, and then packaged with a packaging machine to obtain an aqueous zinc ion 2032 button battery.

[0041] Test results of Experiment 4

[0042] After the zinc ion battery was left at room temperature for 2 hours, cyclic voltammetry test, constant current charge and discharge test and cycle life test were performed in the voltage window of 0.1-1.6V. Figure 3 As shown, at 1mV·S -1 At a scan rate of , two pairs of redox peaks were obtained for HATBPTA.

[0043] like Figure 4 As shown, at 100mA·g -1 At a current density of 160 mAh g -1 The high discharge capacity proves that HATBPTA can be successfully used as electrode materials for aqueous zinc-ion batteries.

Claims

1. A covalent organic framework material based on polybenzimidazole, characterized in that: The covalent organic framework material is HATBPTA, and its structure is as shown in formula (I):

2. The method for preparing a covalent organic framework material based on polybenzimidazoles according to claim 1, characterized in that: The method comprises the following steps: dissolving hexaazine naphthylacetic acid and 3,3'-diaminobenzidine in water, adding a certain amount of catalyst, placing the mixture in a reactor for reaction, filtering, washing and drying to obtain a brown-black product HATBPTA.

3. The preparation method according to claim 2, characterized in that The catalyst is 3M acetic acid solution.

4. The preparation method according to claim 2, characterized in that The molar ratio of the hexaazine naphthyridine carboxylic acid to 3,3'-diaminobenzidine is 1:1.

5.

5. The preparation method according to claim 2, characterized in that The reaction was carried out at 180° C. for three days.

6. The preparation method according to claim 2, characterized in that The drying step is performed at 60° C. for 12 hours.

7. Use of the polybenzimidazole-based covalent organic framework material according to claim 1 as an electrode material for aqueous zinc ion batteries.

8. The use according to claim 7, characterized in that Here’s how: 1) The current collector titanium foil is made into an electrode sheet; 2) grinding the covalent organic framework material according to claim 1, Super P, and polyvinylidene fluoride according to a certain mass ratio, adding solvent NMP and grinding into a uniform and non-granular slurry, and evenly coating the slurry on the electrode sheet; 3) Place the coated electrode sheet in a vacuum drying oven at 60°C for 12 hours to remove the residual solvent, weigh it, and calculate the loading; 4) Battery assembly: Using the 2032 button cell standard, place the zinc sheet, separator, electrolyte, electrode sheet obtained in step 3), gasket, spring, and positive electrode shell in the negative electrode shell in sequence, and then encapsulate them using a packaging machine to obtain an aqueous zinc ion 2032 button cell.

9. The use according to claim 8, characterized in that In step 2), the mass ratio of the covalent organic framework material, Super P, and polyvinylidene fluoride is 6:3:

1.

10. The use according to claim 8, characterized in that In step 4), the concentration of the electrolyte is 1M Zn(CF3SO3)2 aqueous solution with a volume of 120 μL.

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