A two-dimensional organic framework material, a method for synthesizing the same, and an application of the same to a battery

Abstract

The application provides a two-dimensional organic framework material, a synthesis method thereof and an application thereof to a battery. The two-dimensional organic framework material is prepared by using a monomer A and a ligand B. The monomer A includes one of 1,3,5-tri(p-formylphenyl)benzene, tri(4-formylphenyl)amine, tetraaminophenyl methane or a triazine ring. The ligand B includes one of oxalyl hydrazide amide and oxalyl diamide. The two-dimensional organic framework material prepared by the application has a pore size of 1.8 nm. The separator prepared by using the two-dimensional organic framework material prepared by the application not only has a high I3 – blocking capability, but also has a high Zn 2+ transmission rate, so as to maintain normal operation and efficient energy transmission of the battery. The battery prepared by using the separator can significantly improve the overall performance of the zinc-iodine battery, including increasing the discharge capacity, improving the cycle stability and improving the overall battery performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of materials, in particular to a two-dimensional organic framework material, a synthesis method thereof and an application of the two-dimensional organic framework material to a battery. BACKGROUND

[0002] Serious safety problems such as short circuit, combustion and explosion of batteries hinder their marketization process. Under this background, high-safety zinc ion batteries with water-soluble salt as electrolyte and metal zinc or zinc alloy as negative electrode have attracted great attention in the industry due to their high reserves, high energy density, low cost and ability to perform large current charging and discharging, and have become a new focus in the field of batteries. However, the large-scale practical application of zinc ion batteries still faces some problems to be solved. The growth of zinc dendrites and the serious side reactions caused by zinc metal in the aqueous electrolyte lead to the corrosion and passivation of the zinc negative electrode and the rapid consumption of the electrolyte, thereby greatly reducing the performance and service life of the battery, which also affects the prospect of its large-scale application. The existing strategies to improve the reversibility of zinc negative electrode, such as using "salt-in-water" or organic electrolyte, designing a new type of current collector, and building an artificial interface layer, can stabilize the zinc negative electrode to some extent and improve the battery life, but these methods are high in cost or may cause environmental pollution, which does not meet the green and low-cost development requirements of zinc batteries. In addition, the commercial glass fiber separator currently mainly used in zinc batteries not only has high cost, but also has low strength and is easy to break, and has particularly limited inhibition effect on zinc dendrites.

[0003] The potential of iodine batteries goes far beyond this. In addition to the conversion between negative ions and elemental iodine, the positive ions with high reaction potential are obviously more attractive. For example, in the zinc-iodine battery system, paired with zinc metal, the theoretical discharge voltage of the full battery can reach about 1.7 V, which can exceed most reported mature electrode materials such as vanadium oxides, manganese oxides and organic polymers. More importantly, multi-valence conversion will bring multi-electron transfer and thus a huge increase in capacity and energy density. Currently, the polyethylene and polypropylene separators widely used in lithium ion batteries cannot be directly applied to zinc battery systems. In the development process of zinc ion batteries, although the commonly used glass fiber separator shows certain performance. However, in the zinc-iodine battery, the pore size of the glass fiber separator is large, which is difficult to effectively prevent the shuttling of I3 - , affecting its effect.

[0004] In modern battery material research, it is particularly crucial to develop an integrated composite separator with comprehensive functions. This new type of composite separator not only needs to have the ability to effectively block I3 - , thereby effectively preventing its negative impact on battery performance, but also must ensure high Zn 2+The transmittance of the separator is required to be high enough to maintain the normal operation and efficient energy transmission of the battery. Therefore, developing a separator material that meets these performance requirements is of great significance to the improvement of the overall performance of the battery. For zinc-iodine batteries, how to effectively improve their discharge capacity, coulombic efficiency and rate performance is one of the main challenges in the current research field. In order to solve this problem, researchers need to continuously innovate in the design and optimization of the separator, and find a solution that can meet multiple performance requirements. This is not only an important direction of theoretical research, but also a bottleneck that needs to be broken through in practical applications. SUMMARY

[0005] Therefore, the application provides a two-dimensional organic framework material, a synthesis method thereof and an application thereof to a battery.

[0006] The technical scheme of the application is implemented as follows.

[0007] The structure of the two-dimensional organic framework material is as shown in the following formula (1):

[0008]

[0009] Preferably, the synthesis method comprises the following steps:

[0010] The monomer A and the ligand B are mixed, an organic solvent is added for ultrasonic dispersion, a catalyst is added after dispersion, liquid nitrogen freezing is performed for 5-10 minutes, sealing is performed after freezing, heating reaction is performed at 80-150 DEG C for 60-90 hours, and a mixed solution is obtained;

[0011] The mixed solution is washed and dried at 110-130 DEG C to obtain a finished product.

[0012] The monomer A comprises one of 1,3,5-tris(p-formylphenyl)benzene, tris(4-formylphenyl)amine, tetraaminophenyl methane or a triazine ring.

[0013] The ligand B comprises oxalyl hydrazide amide or oxalyl diamide.

[0014] Preferably, the mass ratio of the monomer A and the ligand B is 1-2:1.

[0015] Preferably, the organic solvent comprises o-dichlorobenzene and n-butanol in a mass ratio of 0.5-1:1, and the volume-mass ratio of the organic solvent and the ligand B is 1 mL:10-20 mg.

[0016] The catalyst is an acetic acid solution, the volume ratio of the catalyst and the organic solvent is 1:5-7, and the concentration of the acetic acid solution is 6-12 M.

[0017] Preferably, the two-dimensional organic framework material is applied to the preparation of a zinc-iodine battery separator.

[0018] Preferably, comprising the following steps:

[0019] (1) dispersing the two-dimensional organic framework material of claim 1 in anhydrous ethanol solution, adding binder A to obtain mixed slurry A;

[0020] (2) dispersing the conductive material in anhydrous ethanol, adding binder B to obtain mixed slurry B;

[0021] (3) sequentially filtering the mixed slurry A and the mixed slurry B on the base film, and drying to obtain a zinc-iodine battery separator;

[0022] Preferably, in step (1), the mass percentage of the binder is 1-10% in the binder;

[0023] The mass ratio of the two-dimensional organic framework material to binder A is 1-7:1, and the mass ratio of the conductive material to binder B is 8-10:1;

[0024] The conductive material is one of Ketjen black, graphene and graphyne.

[0025] Preferably, in step (1), the binder A and the binder B are one or more of water-based polyurethane, polyvinylidene fluoride and polyvinylidene carbonate;

[0026] The polyvinylidene fluoride has a polymerization molecular weight of 1-1.1 million, and when the polyvinylidene fluoride is used as the binder, N-methyl pyrrolidone is used to configure a polyvinylidene fluoride solution with a mass concentration of 5%-10%.

[0027] Preferably, the preparation method prepares the zinc-iodine battery separator.

[0028] Preferably, the zinc-iodine battery separator is used in the preparation of a zinc-iodine battery.

[0029] Compared with the prior art, the beneficial effects of the present application are:

[0030] The present application uses 1,3,5-tris(p-formylphenyl)benzene, tris(4-formylphenyl)amine, tetraaminophenyl methane or triazine ring as a monomer, oxalyl hydrazide amide or oxalyl diamide as a ligand, and the monomer and the ligand are reacted to form a covalent organic framework material, which has a suitable pore size design (1.8 nm) that allows Zn 2+ rapidly pass through and can effectively limit I3 - shuttle effect through pore size limitation and electrostatic interaction. The present application develops an integrated composite separator with comprehensive functions.

[0031] The application develops an integrated composite diaphragm with comprehensive functions, which is applied to zinc-iodine battery system and matched with zinc metal, and the theoretical discharge voltage of the full battery can reach about 1.7V, which can exceed most reported mature electrode materials, and the growth of zinc dendrites and the serious side reactions caused by zinc metal in the aqueous electrolyte are overcome, so that the corrosion and passivation of the zinc negative electrode and the rapid consumption of the electrolyte are reduced, thereby the problems of battery performance and service life are greatly reduced. Therefore, the diaphragm can greatly improve the discharge capacity and cycle life of the battery, and contributes important force to the development of zinc battery. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is the reaction mechanism diagram and actual picture of the covalent organic material prepared by using 1,3,5-tris(p-formylphenyl)benzene and ethanedihydrazide amide in the embodiment 1 of the application.

[0033] Figure 2 is the general characterization (a) XRD; (b) IR; (c) BET; (d) pore size distribution of the covalent organic material prepared in the embodiment 1 of the application.

[0034] Figure 3 is the flowchart of the preparation of the composite diaphragm in the embodiment 2 of the application.

[0035] Figure 4 is the I3 of the preparation of the composite diaphragm in the embodiment 2 of the application. - Penetration experiment results.

[0036] Figure 5 is the cycle performance diagram of the symmetric and half symmetric battery assembled by the composite diaphragm prepared in the application example 1 and the application example 2.

[0037] Figure 6 is the cycle performance diagram of the zinc-iodine full battery assembled by the covalent organic material composite diaphragm prepared in the application example 3. DETAILED DESCRIPTION

[0038] In order to better understand the technical content of the application, the following specific embodiments are provided to further illustrate the application.

[0039] The experimental methods used in the embodiments of the application are conventional methods unless otherwise specified.

[0040] The materials, reagents and the like used in the embodiments of the application can be obtained from commercial channels unless otherwise specified.

[0041] Embodiment 1

[0042] Preparation of two-dimensional covalent organic framework material:

[0043] Into a reaction tube, 1, 3, 5-tri (p-formylphenyl) benzene (26 mg) and oxalyl dihydrazide (15 mg) were added, and were ultrasonically dispersed with o-dichlorobenzene and n-butanol (0.5 mL each), and an acetic acid solution (6 M, 0.2 mL) was added, and the mixture was frozen with liquid nitrogen for 5 minutes, and was flame-sealed, and was heated at 120 °C for 3 days. After being cooled to room temperature, a solid powder was obtained, which was washed with anhydrous tetrahydrofuran (THF), and was dried at 120 °C under vacuum to obtain a tan-colored covalent organic framework material.

[0044] Example 2

[0045] Preparation of a two-dimensional organic framework material composite separator:

[0046] 10 mg of the two-dimensional covalent organic framework material prepared in Example 1 was dispersed in 50 mL of anhydrous ethanol solution, and 2 mL of polyvinylidene fluoride with a mass fraction of 5% was added, and 5 mg of graphene was weighed and dispersed in 50 mL of anhydrous ethanol, and 2 mL of polyvinylidene fluoride with a mass fraction of 5% was added, and the mixture was sequentially filtered on a 40 mm circular separator by using suction filtration.

[0047] Example 3

[0048] Preparation of a two-dimensional organic framework material:

[0049] Into a reaction tube, 1, 3, 5-tri (p-formylphenyl) benzene (26 mg) and oxalyl dihydrazide (15 mg) were added, and were ultrasonically dispersed with o-dichlorobenzene and n-butanol (0.5 mL each), and an acetic acid solution (12 M, 0.2 mL) was added, and the mixture was frozen with liquid nitrogen for 5 minutes, and was flame-sealed, and was heated at 120 °C for 3 days. After being cooled to room temperature, a solid powder was obtained, which was washed with anhydrous THF, and was dried at 120 °C under vacuum to obtain a tan-colored covalent organic framework material.

[0050] Example 4

[0051] Preparation of a two-dimensional organic framework material (TFPA-HAD-COF):

[0052] Step 1, into a reaction tube, tri (4-formylphenyl) amine (20 mg) and oxalyl dihydrazide (15 mg) were added, and were ultrasonically dispersed with o-dichlorobenzene (0.3 mL) and n-butanol (0.7 mL), and an acetic acid solution (6 M, 0.3 mL) was added, and the mixture was frozen with liquid nitrogen for 5 minutes, and was flame-sealed, and was heated at 120 °C for 3 days. After being cooled to room temperature, a solid powder was obtained, which was washed with THF, and was dried at 120 °C under vacuum to obtain a tan-colored covalent organic framework material (TFPA-HAD-COF).

[0053] Example 5

[0054] Preparation of a two-dimensional organic framework material (TATB-HAD-COF):

[0055] Step 1, 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine 30 mg, and oxalyl hydrazide amide (15 mg) were added to a reaction tube, sonicated with o-dichlorobenzene (0.6 mL), n-butanol (0.4 mL each), added acetic acid solution (6 M, 0.1 mL), chilled with liquid nitrogen for 5 min, flame sealed, and heated at 120 °C for 3 days. After cooling to room temperature, a solid powder was obtained, which was Soxhlet extracted with THF for 24 h, and dried under vacuum at 120 °C to give a light yellow covalent organic framework material (TATB-HAD-COF).

[0056] Application Example 1

[0057] Preparation of the battery:

[0058] The composite separator obtained in Example 2 was cut into a circular piece with a diameter of 1.8 cm, then a zinc sheet with a diameter of 9 mm was used as the negative electrode, a zinc salt aqueous solution was used as the electrolyte, and a button cell was assembled, including the negative electrode, the spring, the gasket, the composite separator, the electrolyte, and the zinc foil (the half-coin battery was a 12 mm copper foil), and the negative electrode shell.

[0059] Preparation method of the half-coin battery: the assembly of the button half-coin battery was carried out under conventional conditions. The model of the battery shell was CR2032, the positive and negative electrodes were metal zinc sheets, and the positive electrode was a metal copper sheet. The composite separator was used to separate the positive and negative electrodes, and the side with the modified coating faced the copper positive electrode. The injection amount of the electrolyte was 100 μL. The electrolyte was composed of a 2M zinc sulfate solution. After the electrolyte was added, the assembly of the button half-coin battery was completed.

[0060] Application Example 2

[0061] Preparation of the battery:

[0062] The composite separator obtained in Example 2 was cut into a circular piece with a diameter of 1.8 cm, then a zinc sheet with a diameter of 9 mm was used as the negative electrode, a zinc salt aqueous solution was used as the electrolyte, and a button cell was assembled, including the negative electrode, the spring, the gasket, the composite separator, the electrolyte, and the zinc foil (the half-coin battery was a 12 mm copper foil), and the negative electrode shell.

[0063] Preparation method of the button half-coin battery: the assembly of the button half-coin battery was carried out under conventional conditions. The model of the battery shell was CR2032, the positive and negative electrodes were metal zinc sheets, and the composite separator was used to separate the two electrodes. The injection amount of the electrolyte was 100 μL. The electrolyte was composed of a 2M zinc sulfate solution. After the electrolyte was added, the assembly of the button half-coin battery was completed.

[0064] Application Example 3

[0065] Preparation of the battery:

[0066] The composite separator obtained in Example 2 was cut into a circular piece with a diameter of 1.8 cm, then a zinc sheet with a diameter of 9 mm was used as the negative electrode, a zinc salt aqueous solution was used as the electrolyte, and a button cell was assembled, including the negative electrode, the spring, the gasket, the composite separator, the electrolyte, the zinc foil (half of the cell is a 12 mm copper foil), and the negative electrode shell.

[0067] Full cell preparation method: the assembly of the button full cell was carried out under conventional conditions. The model of the cell shell was CR2032, the negative electrode was a zinc sheet, and the positive electrode was an iodine-absorbing activated carbon electrode. The composite separator was used to separate the positive and negative electrodes, and the side with the modified coating faced the iodine-absorbing activated carbon positive electrode. The injection amount of the electrolyte was 100 μL. The electrolyte was composed of 3M zinc sulfate solution and 0.4M zinc iodide solution. After the electrolyte was added, the assembly of the button full cell was completed.

[0068] Reference Example 1 Figure 1 , a yellow-brown covalent organic framework material was obtained. Further characterization of XRD, IR, BET, and the results are shown in Figure 2 . Figure 3 The general flowchart of the preparation of the two-dimensional organic framework material composite separator of Example 2 and the optical photograph thereof are shown.

[0069] Reference Example 2 Figure 4 , the I3 - penetration experiment results, in which the common glass fiber separator was used to test the inhibition effect on I3 - in the electrolytic cell. The left side is 1M ZnSO4+0.1M ZnI2 aqueous solution, and the right side is 1M ZnSO4 aqueous solution. The middle is a common glass fiber separator. After 4 hours of standing, it was found that the right side became light yellow after 4 hours. The solutions on both sides of the composite separator of the present application did not change color, proving that the ordinary separator can penetrate I3 - , and the composite separator has a good inhibitory effect on I3 - .

[0070] The performance of the batteries of Application Example 1 and Application Example 2 was tested, and it can be seen from Figure 5 that the battery can still be cycled for 150 hours at a high current density of 10 mA·cm -2 .

[0071] The full cell cycle performance test of Application Example 3 was carried out, and it can be seen from Figure 6 that the full cell has an initial high surface capacity of 6.0 mAh·cm -2 , and can still be stably cycled for a long time of 550 cycles (1110 hours) at a current density of 20 mA·cm -2 .

[0072] The above merely provides the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A two-dimensional organic framework material, characterized in that, The structure of the two-dimensional organic framework material is as follows formula (1): Formula (1).

2. The method of claim 1, wherein the two-dimensional organic framework material is synthesized by the method comprising: reacting a first organic linker with a second organic linker in the presence of a metal ion to form the two-dimensional organic framework material. The synthesis method comprises the following steps: (1) mixing monomer A and ligand B, adding an organic solvent for ultrasonic dispersion, adding a catalyst after dispersion, freezing for 5-10 minutes with liquid nitrogen, sealing after freezing, and heating at 80-150 DEG C for 60-90 h to obtain a mixed solution; (2) washing the mixed solution and drying at 110-130 DEG C to obtain a finished product; The monomer A comprises one of 1,3,5 tri (p-formylphenyl) benzene, tri (4-formylphenyl) amine, tetraaminophenyl methane or a triazine ring; The ligand B comprises oxalyl hydrazide amide or oxalyl diamide.

3. The method of claim 2, wherein the two-dimensional organic framework material is synthesized by the method comprising: reacting a first organic linker with a second organic linker in the presence of a metal ion to form the two-dimensional organic framework material. In step (1), the mass ratio of the monomer A and the ligand B is 1-2:

1.

4. The method of claim 2, wherein the two-dimensional organic framework material is synthesized by the method comprising: reacting a first organic linker with a second organic linker in the presence of a metal ion to form a two-dimensional organic framework material. In step (1), the organic solvent comprises o-dichlorobenzene and n-butanol with a mass ratio of 0.5-1:1, and the volume-mass ratio of the organic solvent and the ligand B is 1 mL:10-20 mg; The catalyst is acetic acid solution, the volume ratio of the catalyst and the organic solvent is 1:5-7, and the concentration of the acetic acid solution is 6-12 M.

5. The two-dimensional organic framework material of claim 1 in the preparation of a zinc-iodine battery separator.

6. The method of producing a zinc-iodine cell separator as defined in claim 5, characterized in that, Comprise the following steps: (1) dispersing the two-dimensional organic framework material of claim 1 in anhydrous ethanol, adding binder A to obtain mixed slurry A; (2) dispersing the conductive material in anhydrous ethanol, adding binder B to obtain mixed slurry B; (3) sequentially filtering the mixed slurry A and the mixed slurry B on a base film, and drying to obtain a zinc-iodine battery separator.

7. The method of making a zinc-iodine battery separator according to claim 6, wherein, In step (1), the mass percentage of the binder is 1-10%; The mass ratio of the two-dimensional organic framework material and binder A is 1-7:1, and the mass ratio of the conductive material and binder B is 8-10:1; The conductive material is one of ketjen black, graphene and graphdiyne.

8. The method of making a zinc-iodine battery separator of claim 6, wherein, In step (1), the binder A and the binder B are one or more of water-based polyurethane, poly (piperazine-1, 4-ethylene carbonate) and poly (vinylidene fluoride); The poly (vinylidene fluoride) has a polymer molecular weight of 1-1.1 million, and when the poly (vinylidene fluoride) is used as a binder, N-methyl pyrrolidone is used to configure a poly (vinylidene fluoride) solution with a mass concentration of 5%-10%.

9. The zinc-iodine battery separator prepared by the preparation method of any one of claims 6-8.

10. The zinc-iodine battery separator of claim 9 in the preparation of a zinc-iodine battery.

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