A zinc-iodine battery separator based on a three-dimensional covalent organic framework, its preparation method and application

Abstract

This invention provides a zinc-iodine battery separator based on a three-dimensional covalent organic framework, its preparation method, and its application, relating to the research of organic materials and battery energy. This invention obtains organic framework materials (COFs) from tetrakis(4-aminophenyl)methane and terephthalaldehyde ligands via a solvothermal method; the organic framework materials are then assembled with conductive materials on a substrate surface to obtain a composite separator. This composite separator has a suitable pore size, enabling rapid transport of zinc ions (Zn). 2+ Meanwhile, the three-dimensional covalent organic framework can inhibit I3. – The shuttle function. The batteries assembled from them have high capacity, long cycle life, and excellent rate performance at high current densities.

Description

Technical Field

[0001] This invention relates to the field of new energy technology, specifically to a zinc-iodine battery separator with a three-dimensional covalent organic framework, its preparation method, and its application. Background Technology

[0002] While the widespread use of traditional fossil fuels has driven rapid economic development, it has also triggered numerous problems such as the energy crisis and the greenhouse effect, necessitating a clean energy transition. Developing green and renewable energy sources such as solar, wind, and hydropower is an important way to achieve these goals. However, due to environmental and geographical limitations, these renewable energy sources cause significant grid fluctuations, making uninterrupted use difficult. Therefore, it is necessary to develop more efficient energy storage technologies.

[0003] Since its invention in 1990, the lithium-ion battery has been widely used in electronic products and new energy vehicles. This is mainly due to its advantages such as high energy density, high open-circuit voltage, and good cycle stability. However, the high cost of lithium-ion batteries and the safety issues such as flammability and thermal runaway of their organic electrolytes have hindered their further development in the energy storage field, especially in large-scale power plants. While traditional lead-acid batteries have the advantages of low cost and good safety performance, their low volumetric energy density, poor cycle life, and environmental pollution also limit their promotion and application in energy storage. Therefore, there is an urgent need to develop new energy storage battery systems with low cost, high safety, and long lifespan.

[0004] The cathode material of zinc-ion batteries has a crucial impact on performance. Currently, the mainstream cathode materials under development, such as metal oxides, metal sulfides, and Prussian blue compounds, mainly use Zn. 2+ The insertion / extraction mechanism stores charge. Due to Zn 2+ The large hydration radius and limited ion storage space provided by the cathode restrict power performance and energy density. Recently, the conversion reactions of halogen element cathodes have attracted much attention due to their high open-circuit voltage, strong redox kinetics, and excellent charge-discharge stability. Among them, halogen elements, with their high boiling points and low costs, have greater development potential.

[0005] Zinc-iodine secondary batteries use an aqueous solution of dissolved zinc salts as the electrolyte, metallic zinc as the negative electrode, and elemental iodine as the positive electrode, storing charge through a dissolution-deposition mechanism. Compared to batteries employing ion intercalation or conversion reaction mechanisms, this type of battery offers faster reaction speeds, better reversibility, higher energy and power density, and unique advantages such as safety, economy, environmental friendliness, and high efficiency. However, despite its relatively simple reaction mechanism, I3 is generated during charging and discharging. –Intermediate products cause severe shuttle effects, which in turn affect the battery's discharge capacity, coulombic efficiency, and cycle life.

[0006] The main reason for this problem is that the glass fiber separator widely used in traditional zinc-ion batteries has a large pore size (0.7~1.6 μm), making it difficult to effectively block the smaller I3 particles. – Ion shuttle makes it difficult to achieve high-performance zinc-iodine batteries. Although some ion-selective permeable membranes (such as the Nafion series membranes) can effectively suppress I3 through the electrostatic repulsion effect of charge groups. – The shuttle-like movement, but its closed structure will reduce Zn 2+ The low conductivity of Zn leads to severe polarization in the battery, resulting in degraded battery performance. Therefore, the key to solving this problem lies in designing a highly efficient separator that can ensure the conductivity of Zn... 2+ It allows for quick passage while effectively blocking I3. – The shuttle.

[0007] Recently, researchers have proposed a zeolite molecular sieve membrane with a small pore size (0.4 nm) to suppress I3. – The shuttle effect improves performance indicators such as coulombic efficiency, discharge capacity, and cycle stability. Although zeolite molecular sieves can physically suppress I3 through their smaller pore size... – While the transport efficiency is good, the large hydrated ions (0.43 nm) in the aqueous electrolyte limit its efficiency. Furthermore, inorganic particles require additional binders to form the membrane, making it difficult to ensure uniformity and continuity of pore size. Additionally, commercially available iodine-ion batteries typically have a thickness of less than 25 µm, while this zeolite molecular sieve membrane is 60 µm thick, which is detrimental to improving volumetric energy density.

[0008] Therefore, it is necessary to develop a high I3 – Blocking efficiency and high Zn 2+ Developing an integrated composite separator with high permeability to improve the discharge capacity, coulombic efficiency, and rate performance of zinc-iodine batteries is one of the most challenging issues currently facing this field. Summary of the Invention

[0009] To address the difficulty in simultaneously achieving rapid Zn enrichment in zinc-iodine battery separators 2+ Transmission and effective blocking of I3 – To address the problem of zinc-iodine battery separator fabrication, researchers have proposed a novel method for preparing such a separator. This separator utilizes a three-dimensional organic framework (COF) structure with a suitable pore size design, which can ensure the stability of Zn... 2+ Rapidly transmit and block I3 –The conductive material in the separator enhances conductivity. Using this type of separator can significantly improve the performance of zinc-iodine batteries, including discharge capacity, cycle performance, coulombic efficiency, and rate performance.

[0010] Currently, polyethylene and polypropylene separators, widely used in lithium-ion batteries, are difficult to apply directly to zinc battery systems. This is mainly because their non-hydrophilic nature prevents them from wetting aqueous zinc batteries, thus affecting the unobstructed flow of ion channels. While zinc-ion batteries were still in the research and development stage, commonly used glass fiber separators exhibited good performance in oxide and sulfide cathodes, but they failed to achieve ideal results in zinc-iodine batteries.

[0011] To address these issues, we propose a three-dimensional covalent organic framework material, synthesized via a solvothermal reaction of tetra(4-aminophenyl)methane and terephthalaldehyde. It possesses a suitable pore size design (0.8 nm), allowing Zn... 2+ While allowing for rapid passage, the micropore confinement and electrostatic effects effectively limit I3. – Therefore, based on the above mechanism, the prepared three-dimensional composite covalent organic composite membrane can effectively suppress I3. – It facilitates rapid transit and significantly improves battery performance and cycle life.

[0012] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0013] A method for preparing a zinc-iodine battery separator with a three-dimensional covalent organic framework includes the following steps:

[0014] (1) Tetra(4-aminophenyl)methane and terephthalaldehyde ligand were placed in an organic solvent and ultrasonically dispersed to obtain a homogeneous mixed solution;

[0015] (2) Add the mixed solution from step (1) to the catalyst, heat the reaction, cool after the reaction, filter to obtain solid powder, wash and purify the solid powder, dry it to obtain a highly crystalline three-dimensional covalent organic framework material;

[0016] (3) The highly crystalline three-dimensional covalent organic framework material prepared in step (2) and the conductive material are layered and assembled onto the substrate membrane to obtain a zinc-iodine battery membrane with a three-dimensional covalent organic framework.

[0017] Further, in step (1), the terephthalaldehyde ligand is one or more of 2-hydroxyterephthalaldehyde, 2,5-dihydroxyterephthalaldehyde, 2,5-diethoxyterephthalaldehyde, and 2,5-dimethoxyterephthalaldehyde.

[0018] Further, in step (1), the molar ratio of tetra(4-aminophenyl)methane to terephthalaldehyde ligand is 1:1.5-2.5, preferably 1:2.

[0019] Further, in step (1), the organic solvent is one or more of 1,4-dioxane, mesitylene, o-dichlorobenzene, and n-butanol. Preferably, the organic solvent is composed of 1,4-dioxane and mesitylene in a volume ratio of 1:1-4, specifically including a ratio of 1:1, 1:4, or 3:7.

[0020] Further, in step (1), the ultrasonic dispersion time is 10~30 min and the temperature is 20~30℃.

[0021] Further, in step (2), the catalyst is a 3-9 mol / L acetic acid solution, preferably a 3 mol / L acetic acid solution.

[0022] Furthermore, the volume ratio of the organic solvent to the catalyst is 3-5:0.1-0.2.

[0023] Further, in step (2), the reaction temperature is heated to 90-120℃ and the reaction time is 70-90h.

[0024] Furthermore, in step (2), the solvent used for washing and purification is at least one of THF (tetrahydrofuran), methanol, ethyl acetate, and 1,4-dioxane.

[0025] Furthermore, in step (2), the drying is vacuum drying, the drying temperature is 90-130℃, and the drying time is 4-8h.

[0026] Further, in step (3), the conductive material is one or more of graphene, Ketjen black, carbon black, and acetylene black.

[0027] Further, in step (3), the pore size of the substrate diaphragm is 1-5 μm, and the substrate diaphragm is any one of glass fiber filter paper, polyethylene diaphragm, and polypropylene diaphragm.

[0028] Further, step (3) specifically involves: dispersing the organic framework material in ethanol, with a mass-to-volume ratio of 4-6 mg to 30-50 ml, to obtain an organic framework material liquid; then dispersing the conductive material in another portion of ethanol, with a mass-to-volume ratio of 8-12 mg to 30-50 ml, to obtain a conductive material liquid; the mass ratio of the organic framework material to the conductive material is 4-6:8-12; and using a vacuum filtration method, sequentially filtering the organic framework material liquid and the conductive material liquid onto the substrate membrane to form a zinc-iodine battery membrane.

[0029] Furthermore, the zinc-iodine battery separator has a thickness of 15-20 mm, and its natural thickness before assembly is 800-1000 μm. Preferably, the zinc-iodine battery separator has a thickness of 18 mm, and its natural thickness before assembly is 900 μm.

[0030] Furthermore, the methane in the tetra(4-aminophenyl)methane is replaced with adamantane.

[0031] A zinc-iodine battery separator with a three-dimensional covalent organic framework is prepared by any one of the preparation methods described in this invention.

[0032] A zinc-iodine battery, comprising a positive electrode, a negative electrode, an electrolyte, and the battery separator described in this invention.

[0033] Furthermore, the positive electrode is made of carbon material, with the addition of a binder, and after preparing a slurry, iodine adsorption is performed to form the positive electrode. The carbon material is one or more of microporous carbon, coconut shell carbon, or activated carbon, and the binder is one or more of polyvinylidene fluoride, polytetrafluoroethylene, and polyaniline.

[0034] The negative electrode is a zinc foil or other zinc-containing metal alloy.

[0035] The electrolyte is an aqueous solution of zinc salts, including zinc sulfate, zinc iodide, and zinc trifluoromethanesulfonate.

[0036] Furthermore, the electrolyte is composed of an aqueous solution of 2-5 mol / L ZnSO4 and 0.1-0.3 mol / L ZnI2.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) This invention uses tetra(4-aminophenyl)methane and terephthalaldehyde ligands to form a covalent organic framework membrane with a suitable pore size design (0.8 nm), which allows Zn 2+ While allowing rapid passage, I3 can be effectively limited through aperture confinement and electrostatic effects. – Based on the above mechanism, this diaphragm can effectively suppress I3. – It facilitates the shuttle between different parts of the battery and significantly improves the battery's coulombic efficiency, discharge capacity, and cycle life.

[0039] (2) The amino or aldehyde groups in the raw materials of this invention are superior to aldehyde or amine monomers containing sulfonate groups in terms of preparation methods, and will have the advantage of "low cost" in actual production. At the same time, the assembled full battery is a zinc-iodine battery, which avoids the environmental pollution caused by common positive electrode materials such as manganese dioxide, Prussian blue, and vanadium pentoxide. In addition, the substrate used in this invention is a glass fiber membrane, which does not require complicated pretreatment and preparation.

[0040] (3) Compared with the "a zinc-iodine battery separator based on a covalent organic framework and its preparation method and application" disclosed in patent CN 115693022 B and the "a lithium-ionized covalent organic framework nanosheet separator and its preparation and application" disclosed in CN 110534683 B, the battery prepared by this invention has better performance, for example: it can withstand high current density (20 mA·cm) 2 It can operate stably for more than 800 cycles, further enhancing the performance of the full battery in actual production and daily life.

[0041] (4) In existing technologies (e.g., CN 115693022 B, CN 110534683 B), the preparation of self-supporting membranes involves processes such as heating and evaporation, which are relatively complex. Furthermore, the crystalline structure of covalent organic frameworks is generally uneven, leading to inhomogeneous pores and hindering ion conduction. This is especially true for the preparation of Li-based membranes, which is cumbersome and unsuitable for large-scale production. In contrast, the three-dimensional composite covalent organic membrane prepared by this invention allows for the rapid synthesis and expansion of different types of covalent organic frameworks. The entire process is convenient, simple, and fast, and has greater potential for industrial application.

[0042] (5) Compared with glass fiber membranes and Nafion membranes, the covalent organic framework membrane prepared in this invention exhibits significantly improved discharge capacity, cycle performance, coulombic efficiency, and rate performance when applied to zinc-iodine batteries. Even after hundreds of high-current charge-discharge cycles, its capacity retention rate is high, far exceeding the performance of some current zinc-based batteries and zinc-iodine batteries, thus showing great application potential in energy storage rechargeable batteries.

[0043] (6) The three-dimensional covalent organic framework composite membrane prepared by this invention adopts a one-step synthesis process, which is simple and conducive to large-scale manufacturing. At the same time, the raw materials are inexpensive and environmentally friendly. In addition, the covalent organic framework material prepared by this Schiff base reaction can be further assembled into a membrane with recycling advantages, as it can be dissolved in acidic solutions and does not pollute the environment.

[0044] (7) Zinc-iodine batteries prepared using the three-dimensional covalent organic framework zinc-iodine battery separator of the present invention have wide applications in energy storage devices, grid peak-shaving energy storage, low-speed electric vehicles, road lighting, port machinery, emergency power supply and other fields. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the three-dimensional covalent organic framework material prepared using tetrakis(4-aminophenyl)methane and terephthalaldehyde in Example 1.

[0046] Figure 2This is a photograph of the three-dimensional covalent organic framework material prepared in Example 1.

[0047] Figure 3 This is the XRD pattern of the three-dimensional covalent organic framework material prepared in Example 1.

[0048] Figure 4 This is a cross-sectional SEM image of the covalent organic material composite membrane prepared in Example 1.

[0049] Figure 5 I3 is the covalent organic material composite membrane prepared in Example 1. – Results of (iodine ion) penetration experiments, namely, optical photographs of three-dimensional covalent organic framework composite membranes blocking polyiodine compounds.

[0050] Figure 6 This is an optical photograph of the adamantane-centered three-dimensional covalent organic framework composite membrane used in Example 2 to block polyiodine compounds.

[0051] Figure 7 The graph shows the charge-discharge cycle performance of a zinc-iodine full battery assembled with the covalent organic material composite separator prepared in Application Example 1.

[0052] Figure 8 The graph shows the rate performance of the zinc-iodine full cell assembled with the covalent organic material composite separator prepared in Application Example 1. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solutions of this invention, without departing from the spirit and scope of the invention, should be covered within the protection scope of this invention.

[0054] The raw materials and consumables used in the following specific implementation methods were all purchased from the market.

[0055] Example 1

[0056] Preparation of three-dimensional covalent organic framework composite membranes:

[0057] This invention utilizes tetra(4-aminophenyl)methane and terephthalaldehyde to prepare three-dimensional covalent organic framework materials, and the synthetic route is as follows: Figure 1 As shown.

[0058] Step 1: Tetra(4-aminophenyl)methane (40 mg) and terephthalaldehyde (20 mg) were added to a reaction tube, followed by dioxane (1.5 mL) and mesitylene (1.5 mL). The mixture was ultrasonically dispersed at 20-30°C for 15 minutes. Acetic acid solution (3 M, 0.1 mL) was added, and the mixture was frozen in liquid nitrogen, flame-sealed, and heated at 120°C for 72 hours. After cooling to room temperature, the solid powder was obtained by filtration, washed with anhydrous THF, and vacuum dried at 120°C for 4-8 hours to obtain a yellow three-dimensional covalent organic framework material powder, as shown below. Figure 2 As shown. Further characterization of its XRD pattern yielded the following results. Figure 3 As shown.

[0059] Step 2: Disperse 5 mg of the three-dimensional covalent organic framework material powder from Step 1 in 40 ml of anhydrous ethanol to obtain a three-dimensional covalent organic framework material liquid; then weigh 10 mg of graphene and disperse it in another 40 ml of anhydrous ethanol to obtain a graphene liquid; using a conventional vacuum filtration method, sequentially filter the three-dimensional covalent organic framework material liquid and the graphene liquid onto a glass fiber membrane (substrate membrane), and dry them to obtain a composite membrane. The prepared composite membrane was characterized by cross-sectional SEM. Figure 4 The results show that the cross-sectional morphology demonstrates good consistency of the material.

[0060] Electrolytic cell testing of composite diaphragm against I3 – Inhibitory effects, such as Figure 5 As shown, the left side contains a 1 M ZnSO4 + 0.1 M ZnI2 aqueous solution (simulating I3). – The right side shows a 1 M ZnSO4 aqueous solution. The middle section shows a three-dimensional covalent organic framework composite membrane. After standing for 6 hours (see...), Figure 5 The aqueous solution on the right side remained colorless, indicating that the composite separator has excellent inhibition properties, laying the foundation for improving battery performance.

[0061] The prepared composite separator was subjected to full-cell cycle performance testing. Adsorbed iodine was used as the positive electrode, zinc foil as the negative electrode, and a 3 M ZnSO4 + 0.2 M ZnI2 aqueous solution as the electrolyte. The full-cell cycle performance was tested using a battery charge-discharge testing instrument. Figure 7 It can be seen that the full battery has 6.5 mAh·cm³. 2 The initial high capacitance, at a current density of 20 mA·cm 2 It can still stably cycle for a long time of 800 times (1600 hours).

[0062] The rate performance of the prepared composite membrane in a full-cell test was performed. Adsorbed iodine was used as the positive electrode, zinc foil as the negative electrode, and a 3 M ZnSO4 + 0.2 M ZnI2 aqueous solution as the electrolyte. Different current densities were used to test the rate performance of the full cell. Figure 8 It can be seen that, through 10 20 mA·cm 2 Under different current densities, the capacity decay is small, and it can recover to the initial capacity after cycling, indicating that it has good rate performance.

[0063] Example 2

[0064] Preparation of adamantane-centered three-dimensional covalent organic framework composite membrane:

[0065] Step 1: Tetraaminophenyladamantane (53 mg) and terephthalaldehyde (20 mg) were added to a reaction tube, along with dioxane (2 mL) and mesitylene (2 mL). The mixture was ultrasonically dispersed at 20–30 °C for 20 minutes. Acetic acid solution (3 M, 0.15 mL) was added, and the mixture was frozen in liquid nitrogen, flame-sealed, and heated at 120 °C for 120 h. After cooling to room temperature, the solid powder was obtained by filtration, extracted with anhydrous THF using a Soxhlet extractor for 24 hours, and vacuum dried at 120 °C for 4–8 h to obtain a yellow adamantane-centered three-dimensional covalent organic framework material powder.

[0066] Step 2: Disperse 5 mg of the adamantane three-dimensional covalent organic framework material powder from Step 1 in 40 ml of anhydrous ethanol to obtain an adamantane three-dimensional covalent organic framework material liquid; then weigh 10 mg of graphene and disperse it in another 40 ml of anhydrous ethanol to obtain a graphene liquid; use vacuum filtration to sequentially filter the adamantane three-dimensional covalent organic framework material liquid and the graphene liquid onto a glass fiber diaphragm (substrate diaphragm). Dry and set aside for later use.

[0067] Electrolytic cell testing of the effect of adamantane three-dimensional covalent organic framework membrane on I3 – The inhibition effect of the adamantane three-dimensional covalent organic framework membrane on polyiodide polymers was tested under static conditions. The left side of the H-electrolyte contained aqueous solutions of ZnSO4 and ZnI2, while the right side contained an aqueous solution of ZnSO4. The middle layer consisted of an adamantane three-dimensional covalent organic framework membrane.

[0068] The prepared adamantane three-dimensional covalent organic framework membrane was subjected to full-cell cycle performance testing. Adsorbed iodine was used as the positive electrode, zinc foil as the negative electrode, and ZnSO4 and ZnI2 aqueous solutions were used as electrolytes. The full-cell cycle performance was tested using a battery charge-discharge test instrument.

[0069] The rate performance of the prepared adamantane three-dimensional covalent organic framework membrane was tested for full cells. Similarly, adsorbed iodine was used as the positive electrode, zinc foil as the negative electrode, and ZnSO4 and ZnI2 aqueous solutions were used as electrolytes to test the rate performance of the full cells at different current densities.

[0070] The results are as follows Figure 6 As shown, after standing for 6 hours, the zinc sulfate solution on the right side of the H electrolytic cell became colorless, indicating that the three-dimensional covalent organic framework composite membrane centered on adamantane also has excellent inhibitory effect on polyiodine compounds.

[0071] Comparative Example

[0072] Based on Example 1, different combinations of aldehyde and amine monomers will yield different three-dimensional organic framework materials.

[0073] Comparative Group 1: The synthesis of three-dimensional organic materials from carbon-centered 4-aminophenylmethane and terephthalaldehyde resulted in materials with shorter chain connections, leading to smaller pores, which is detrimental to Zn. 2+ Pass through quickly.

[0074] Comparative Group 2: Three-dimensional organic materials were synthesized from carbon-centered 4-aminophenylmethane and p-2,5-diethoxybenzaldehyde. Due to the modification of the side chains, the resulting materials had a smaller specific surface area, which was not conducive to the performance of the battery.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the preparation of a zinc-iodine battery separator of a three-dimensional covalent organic framework, characterized in that, Includes the following steps: (1) Tetra(4-aminophenyl)methane and terephthalaldehyde ligand were placed in an organic solvent and ultrasonically dispersed to obtain a mixed solution; (2) Add the mixed solution from step (1) to the catalyst and heat the reaction at a temperature of 90-120℃ for 70-90h. After the reaction, cool the solution, filter the solid powder, wash and purify the solid powder, and dry it to obtain the organic framework material. (3) The organic framework material and conductive material prepared in step (2) are sequentially layered and assembled onto the substrate membrane to obtain a zinc-iodine battery membrane with a three-dimensional covalent organic framework. The structural formula of terephthalaldehyde is shown below: 。 2. The method for preparing a zinc-iodine battery separator with a three-dimensional covalent organic framework according to claim 1, characterized in that, In step (1), the molar ratio of tetra(4-aminophenyl)methane to terephthalaldehyde ligand is 1:1.5-2.5; the organic solvent is one or more of 1,4-dioxane, mesitylene, o-dichlorobenzene, and n-butanol.

3. The method for preparing a zinc-iodine battery separator with a three-dimensional covalent organic framework according to claim 1, characterized in that, In step (2), the catalyst is a 3-9 mol / L acetic acid solution; The volume ratio of the organic solvent in step (1) to the catalyst in step (2) is 3-5:0.1-0.2; In step (2), the solvent used for washing and purification is at least one of tetrahydrofuran, methanol, ethyl acetate, and 1,4-dioxane; Step (2) involves vacuum drying at a temperature of 90-130℃ for 4-8 hours.

4. The method for preparing a zinc-iodine battery separator with a three-dimensional covalent organic framework according to claim 1, characterized in that, In step (3), the conductive material is one or more of graphene, Ketjen black, and acetylene black; the pore size of the substrate membrane is 1-5 μm, and the substrate membrane is any one of glass fiber membrane, polyethylene membrane, and polypropylene membrane.

5. The method for preparing a zinc-iodine battery separator with a three-dimensional covalent organic framework according to claim 1, characterized in that, Step (3) is as follows: the organic framework material is dispersed in ethanol, with a mass-volume ratio of 4-6 mg to 30-50 ml, to obtain an organic framework material liquid; the conductive material is then dispersed in another portion of ethanol, with a mass-volume ratio of 8-12 mg to 30-50 ml, to obtain a conductive material liquid; the organic framework material liquid and the conductive material liquid are sequentially filtered onto the substrate membrane using a vacuum filtration method to prepare a zinc-iodine battery membrane.

6. The method for preparing a zinc-iodine battery separator with a three-dimensional covalent organic framework according to claim 1, characterized in that, The thickness of the zinc-iodine battery separator is 15-20 mm.

7. The method for preparing a zinc-iodine battery separator with a three-dimensional covalent organic framework according to any one of claims 1-6, characterized in that, The tetra(4-aminophenyl)methane is replaced with tetra(4-aminophenyl)adamantane.

8. A zinc-iodine battery separator with a three-dimensional covalent organic framework, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.

9. A zinc-iodine battery, characterized in that, The zinc-iodine battery includes a positive electrode, a negative electrode, an electrolyte, and the zinc-iodine battery separator as described in claim 8.

10. The zinc-iodine battery according to claim 9, characterized in that, The positive electrode is made of carbon material, with the addition of a binder, and after preparing a slurry, iodine adsorption is performed to form the positive electrode. The carbon material is one or more of microporous carbon, coconut shell carbon, or activated carbon, and the binder is one or more of polyvinylidene fluoride, polytetrafluoroethylene, and polyaniline. The negative electrode is a zinc foil or other zinc-containing metal alloy. The electrolyte is an aqueous solution of zinc salt, which is composed of 2-5 mol / L ZnSO4 and 0.1-0.3 mol / L ZnI2 aqueous solution.

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