Aza-aromatic fused ring polymer, preparation method and application of aza-aromatic fused ring polymer in preparation of aqueous zinc ion battery

Abstract

The invention provides an aza-aromatic fused ring polymer, and belongs to the technical field of rechargeable batteries, and the aza-aromatic fused ring polymer is obtained by sequentially carrying out bromination reaction, debromination reaction and dehydration condensation reaction on 2, 6-diamino-anthraquinone. The aza-aromatic fused ring polymer can be used as a positive electrode of a water-based zinc ion battery, the cycling stability and electrochemical performance of the water-based zinc ion battery can be effectively improved, and the weather resistance of the water-based zinc ion battery can also be improved. The invention also provides a preparation method of the aza-aromatic fused ring polymer and application of the aza-aromatic fused ring polymer in preparation of an aqueous zinc ion battery.

Description

Technical Field

[0001] This invention belongs to the field of rechargeable battery technology, and specifically relates to a nitrogen-containing aromatic fused ring polymer, its preparation method, and its application in the preparation of aqueous zinc-ion batteries. Background Technology

[0002] Non-aqueous lithium-ion batteries possess advantages such as high specific capacity and long cycle life, making them the mainstream energy storage system in mobile electronic devices and emerging hybrid electric vehicles. However, the scarcity and high price of lithium resources, along with serious safety hazards, restrict the large-scale application of lithium batteries in high-safety-level environments such as power plants. Furthermore, organic electrolytes, due to their highly toxic and flammable properties, increase safety risks in practical battery applications. Therefore, replacing batteries containing organic electrolytes with aqueous batteries not only helps improve the stability and safety of energy storage systems but also yields more cost-effective battery devices. Aqueous zinc-ion batteries (AZIBs) are resource-rich, environmentally friendly, and possess excellent redox potentials. , Its high theoretical capacity and fast dynamics make it increasingly popular.

[0003] However, suitable cathode materials are currently lacking to meet the high and low temperature requirements of aqueous zinc-ion batteries. Inorganic cathode materials typically have rigid structures, which often lead to difficult ion intercalation during charge and discharge, resulting in slow electrochemical kinetics and low capacity. Compared to inorganic electrode materials, research on organic electrode materials has made continuous breakthroughs. Organic materials, due to their inherent flexibility, properties that can be regulated by molecular engineering, abundant natural resources, and recyclability, provide an alternative and more diverse material space for electrode design. Traditional organic electrode materials, due to limited electron delocalization and high solubility, suffer from poor conductivity, low redox activity, and unstable electrochemical performance, limiting their application under harsh conditions. Therefore, developing an electrode design strategy to regulate electron delocalization, improve the structural stability of organic cathode materials, and achieve structural stability and rapid diffusion kinetics is of great significance for enhancing the overall electrochemical performance of organic cathode materials. Summary of the Invention

[0004] To address the issues of insufficient conductivity, structural instability, and low redox activity in existing organic cathode materials, this invention provides a nitrogen-containing aromatic fused-ring polymer. This nitrogen-containing aromatic fused-ring polymer can be used as a cathode in aqueous zinc-ion batteries, effectively improving the cycle stability and electrochemical performance of aqueous zinc-ion batteries, and also enhancing their weather resistance.

[0005] The present invention also provides a method for preparing a nitrogen-containing aromatic fused-ring polymer and its application in the preparation of aqueous zinc-ion batteries.

[0006] This invention is achieved through the following technical solution:

[0007] This invention provides a nitrogen-containing aromatic fused-ring polymer, the structural formula of which is as follows: ;

[0008] Where n is between 3 and 100.

[0009] Based on the same inventive concept, the present invention provides a method for preparing a nitrogen-containing aromatic fused-ring polymer, the method comprising: subjecting 2,6-diaminoanthraquinone to a bromination reaction, a debromination reaction and a dehydration condensation reaction in sequence to obtain a nitrogen-containing aromatic fused-ring polymer.

[0010] Furthermore, the preparation method specifically includes:

[0011] S1. Dissolve 2,6-diaminoanthraquinone (DAAQ) and N-bromosuccinimide in an organic solvent to obtain a 2,6-diaminoanthraquinone solution and an N-bromosuccinimide solution, respectively. Add the N-bromosuccinimide solution dropwise to the 2,6-diaminoanthraquinone solution at 0±5℃. After heating, carry out the bromination reaction under an inert atmosphere. After the reaction is completed, remove the solvent. Wash and vacuum dry the crude product to obtain 2,6-diamino-1,5-bromo-anthraquinone (DAAQ-Br).

[0012] S2. Under an inert atmosphere, the 2,6-diamino-1,5-bromo-anthraquinone and hexanoic anhydride solution were microwave-treated at 170-190 °C for 0.5-1 h. The crude product was filtered, washed and vacuum-dried to obtain DAAQ-Br-C6.

[0013] S3. The DAAQ-Br-C6, copper powder, and iodine are added to an organic solvent and heated to 120-140 °C for 18-28 h under an inert atmosphere. After the reaction is completed, the mixture is filtered, and the filtrate is poured into water to precipitate the solid. Solid-liquid separation is then performed, and the obtained solid is recrystallized with a mixed solution of tetrahydrofuran and ether. The crystals are washed and vacuum dried to obtain Pre-PPP.

[0014] S4. The Pre-PPP, dilute hydrochloric acid and 1,4-dioxane are mixed and heated at 150±10 °C for 40-54 h. After cooling, solid-liquid separation is performed. The obtained solid is washed and dried to obtain the nitrogen-aromatic fused ring polymer (PPP).

[0015] The structural formulas of DAAQ-Br-C6 and Pre-PPP are as follows:

[0016] , .

[0017] Preferably, in step S1, the molar ratio of 2,6-diaminoanthraquinone and N-bromosuccinimide is 1:(2-3).

[0018] The inert atmosphere is argon or nitrogen;

[0019] The bromination reaction was carried out at a temperature of 25±5 ℃ for 20–28 h.

[0020] The crude product obtained is washed and vacuum dried, specifically including:

[0021] The crude product was washed several times with water and ethanol, and then vacuum dried at 60–100 °C for 8–16 h.

[0022] Preferably, in step S2, the molar ratio of DAAQ-Br to hexanoic anhydride is 1:(5-15), and the reaction temperature is 170-190°C. o C, reaction time is 0.5 to 1 hour;

[0023] The crude product obtained is subjected to filtration, washing, and vacuum drying, specifically including:

[0024] The crude product was filtered and then washed several times with water and ethanol. The washed product was then vacuum dried at 60–100 °C for 8–16 h.

[0025] Preferably, in step S3, the molar ratio of DAAQ-Br-C6, copper powder, and iodine is 1:(1.5-3.5):(0.01-0.5).

[0026] The obtained solid is recrystallized from a mixed solution of tetrahydrofuran and ether, and the crystals are washed and vacuum dried, specifically including:

[0027] The obtained solid was recrystallized from a mixed solution of tetrahydrofuran and ether in a volume ratio of 1:(0.5–1.5). The crystals were washed several times with water and ethanol, and then dried under vacuum at 60–100 °C for 8–16 h.

[0028] Preferably, in step S4, the concentration of the dilute hydrochloric acid is 1.5–2.5 mol / L;

[0029] The volume ratio of 1,4-dioxane to the dilute hydrochloric acid is 1:(3-5).

[0030] The obtained solid material is washed and dried to obtain a nitrogen-containing aromatic fused-ring polymer, specifically including:

[0031] The obtained solid was washed sequentially with tetrahydrofuran, water and ethanol, and the washing product was vacuum dried at 60-100℃ for 8-16 h to obtain a nitrogen-containing aromatic fused ring polymer.

[0032] Based on the same inventive concept, this invention provides the application of a nitrogen-containing aromatic fused-ring polymer as a raw material or in the preparation of organic cathode materials.

[0033] Based on the same inventive concept, this invention provides an application of nitrogen-containing aromatic fused ring polymers in the preparation of aqueous zinc-ion batteries.

[0034] Based on the same inventive concept, the present invention also provides a wide-temperature-range aqueous zinc-ion battery, wherein the aqueous zinc-ion battery contains the aforementioned nitrogen-containing aromatic fused-ring polymer.

[0035] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0036] 1. This invention discloses a nitrogen-containing aromatic fused-ring polymer, which promotes intermolecular charge jumping and carrier migration, facilitates the formation of open two-dimensional channels in aromatic rings, enhances π-electron delocalization and ion migration, thereby improving electronic / ionic conductivity and ensuring rapid electrochemical kinetics at high / low temperatures. Furthermore, due to the extension of the aromatic backbone, the tight stacking of aromatic rings, and the strong intermolecular π-π interactions, this polymer exhibits excellent corrosion resistance and insolubility in any electrolyte, thereby enhancing its structural stability and long-term cycle durability during charge and discharge processes.

[0037] 2. This invention discloses a nitrogen-containing aromatic fused-ring polymer, which can be used to prepare battery cathodes and exhibits high reversible capacity under both high and low temperature conditions: at room temperature (25 °C), the specific capacity is 205 mAh g⁻¹. -1 The current density is 0.1 A. -1 At a high temperature of 50 °C, the specific capacity is 214 mAh g. -1 The current density is 0.1 A. -1 At a low temperature of -70 °C, the specific capacity is 85 mAh g. -1 The current density is 0.1 A. -1 It also has excellent cycle performance, with a long cycle life of more than 10,000 cycles, and excellent rate performance.

[0038] 3. This invention discloses a nitrogen-atom aromatic fused-ring polymer. Its high reversible capacity and rapid charge transfer capability make it a promising candidate for use as a cathode material in aqueous zinc-ion batteries. It solves the problems of insufficient conductivity, structural instability, and low redox activity of existing organic cathode materials. Furthermore, the raw materials for preparing this nitrogen-atom aromatic fused-ring polymer are green, environmentally friendly, and inexpensive, and it has good application prospects.

[0039] 4. The present invention relates to the application of a nitrogen-containing aromatic fused-ring polymer in the preparation of aqueous zinc-ion batteries. When the nitrogen-containing aromatic fused-ring polymer is used to make the positive electrode of the aqueous zinc-ion battery, it has excellent specific capacity, fast electrochemical reaction kinetics, good rate performance, long cycle life and excellent weather resistance, thereby improving the cycle stability, electrochemical performance and weather resistance of the aqueous zinc-ion battery, so that the aqueous zinc-ion battery has excellent comprehensive electrochemical performance. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 TEM image of the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1;

[0042] Figure 2 The infrared spectra of the nitrogen-aromatic fused-ring polymer synthesized in Example 1 and the infrared spectra of the precursors for each step are shown below.

[0043] Figure 3 Gel permeation chromatogram (GPC) of the polymer precursor Pre-PPP;

[0044] Figure 4 Thermogravimetric analysis (TGA) diagram of the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1;

[0045] Figure 5 The graph shows the resistance and conductivity of the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1 as a function of temperature.

[0046] Figure 6 The graph shows the constant current charge-discharge curves of an aqueous zinc-ion battery using the nitrogen-atom aromatic fused-ring polymer synthesized in Example 1 as the positive electrode material at different temperatures.

[0047] Figure 7 The graph shows the rate performance of an aqueous zinc-ion battery using the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1 as the cathode material at different temperatures.

[0048] Figure 8 An aqueous zinc-ion battery using the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1 as the positive electrode material at a current density of And cycling performance graphs at different temperatures;

[0049] Figure 9 The graph shows a comparison of the ion diffusion coefficients of an aqueous zinc-ion battery using the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1 as the positive electrode material at different temperatures. Where a represents the polymer at different temperatures and current densities of 0.05 A / g. -1 The constant current intermittent titration curve (GITT) is shown below; b is the diffusion coefficient of the polymer at different temperatures. Detailed Implementation

[0050] The present invention will be described in detail below with reference to specific embodiments and examples, thereby making the advantages and various effects of the present invention more clearly apparent. Those skilled in the art should understand that these specific embodiments and examples are for illustrative purposes only and are not intended to limit the present invention.

[0051] Throughout this specification, unless otherwise specified, the terminology used herein should be understood as having the meaning commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any conflict, this specification shall prevail.

[0052] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0053] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0054] The following will provide a detailed description of the nitrogen-containing aromatic fused-ring polymer, its preparation method, and its application in the preparation of aqueous zinc-ion batteries, in conjunction with examples and experimental data.

[0055] Example 1

[0056] This embodiment provides a method for preparing a nitrogen-containing aromatic fused-ring polymer. The specific synthetic route and steps are as follows:

[0057] Synthesis route:

[0058] .

[0059] Synthesis steps:

[0060] (1) Bromination reaction: 2,6-Diaminoanthraquinone (DAAQ, 2.38 g, 10 mmol) was dissolved in 140 ml DMF and transferred to a three-necked flask; N-bromosuccinimide (3.75 g, 21 mmol) was dissolved in 20 ml DMF and slowly added dropwise to the flask at 0 °C for 30 min. The reaction was carried out at room temperature (25 °C) under argon atmosphere for 24 h. The solvent was removed by rotary evaporation under reduced pressure; the crude product was washed several times with water and ethanol (AR) and dried in a vacuum oven at 80 °C for 12 h to obtain DAAQ-Br.

[0061] (2) Under argon conditions, the DAAQ-Br (1.0 g, 2.5 mmol) and hexanoic anhydride (5 ml, 22 mmol) solution was heated to 180 °C by microwave for 0.5 h to assist the reaction. After filtration, the solution was washed several times with water and ethanol, and dried in a vacuum oven at 80 °C for 12 h to obtain DAAQ-Br-C6.

[0062] (3) Debromination reaction: DAAQ-Br-C6 (2.95 g, 5 mM), copper powder (0.65 g, 10 mM) and iodine (25 mg, 0.1 mM) were added to 75 ml DMF and refluxed at 130 °C for 24 h under N2 atmosphere; the hot reaction mixture was filtered and the solution was collected. The mixed solution was poured into water to precipitate and separate the solid product, which was then filtered; the product was recrystallized with tetrahydrofuran and ether (volume ratio 1:1). The solid was filtered and washed several times with water and ethanol, and finally dried in a vacuum oven at 80 °C for 12 h to obtain Pre-PPP.

[0063] (4) Dehydration condensation reaction: 0.434 g of Pre-PPP, 18 ml of HCl (2M) and 5 ml of 1,4-dioxane were added to a 50 ml reactor and heated at 150 °C for 48 h. After cooling naturally to room temperature, the black product was recovered by filtration and washed with tetrahydrofuran, water and ethanol in sequence. Then it was dried in a vacuum oven at 80 °C for 12 h to obtain the final product, nitrogen-acidic fused ring polymer (PPP).

[0064] Pre-PPP precursor was tested by gel permeation chromatography (GPC), utilizing the relationship between the polymer and the precursor (n... (PPP) =n (Pre-PPP) – 1), it can be concluded that the range of n in the structural formula of the PPP prepared in this embodiment is 3-100.

[0065] Battery fabrication: The prepared polymer, conductive carbon (Ketjen Black), and binder (PVDF) were mixed in a mass ratio of 6:3:1. NMP solution was added, and the mixture was ground into a slurry. This slurry was then coated onto titanium foil and dried in a vacuum oven at 80–120°C for 8–12 hours to obtain the electrode sheet. The positive electrode sheet was used as the positive electrode, and the zinc foil as the negative electrode. A glass fiber separator was used to separate the two electrodes. An aqueous zinc perchlorate electrolyte was added, and the cells were assembled into a CR2032 button cell.

[0066] Related tests:

[0067] The degree of polymerization of the polymer was determined by gel permeation chromatography (GPC). High-resolution transmission electron microscopy (HRTEM) was performed using a Themis Z instrument. Fourier transform infrared spectroscopy (FT-IR, ThermoScientific Nicolet iS5) was used to analyze the spectral properties of the polymer. Thermogravimetric analysis (TGA, sta449f5) was used to test the thermal stability of PPP in air from 30 to 900 °C. The polymer conductivity was measured using a PPMS-9 temperature and field controlled platform + KEITHLEY 2400 source meter + KEITHLEY 2182A nanovoltmeter in the range of -50 to 50 °C. The electrochemical performance and GITT of the polymer in the voltage range of 0.2 to 1.6 V were tested on NEWAER.

[0068] The test results are as follows:

[0069] Figure 1 The image shows a TEM image of the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1. The material exhibits a graphite-like disordered stacking state, demonstrating its microscopic morphological characteristics.

[0070] Figure 2 The infrared spectra of the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1 and the infrared spectra of the precursors for each step are shown. The spectra show the chemical structures of the reaction products at each stage and the appearance / disappearance of the corresponding functional groups CH2, CH3, C-Br, C=N, C=O and -NH2, which proves the rationality of the synthetic route and the preparation of the final product.

[0071] Figure 3 The image shows the gel permeation chromatogram (GPC) of the polymer precursor Pre-PPP. Calculations show that the structural formula of the aza-aromatic fused-ring polymer has n values ​​ranging from 3 to 100.

[0072] Figure 4 The thermogravimetric analysis (TGA) diagram of the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1 shows that the polymer has good structural thermal stability.

[0073] Figure 5 The graph shows the resistance and conductivity of the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1 as a function of temperature (-50 to 50°C). It can be observed that as the temperature increases, the resistance of the nitrogen-containing aromatic fused-ring polymer decreases, while its electronic conductivity increases, exhibiting a conductivity of 5.75 × 10⁻⁶ at room temperature. -4 S cm –1 High electrical conductivity.

[0074] Figure 6 To test the aqueous zinc-ion battery using the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1 as the positive electrode material, at 0.1 A g... -1 The current density and constant current charge-discharge curves at different temperatures are shown. Similar redox processes are observed at different temperatures, indicating that temperature has no significant effect on the redox reaction of the nitrogen-aromatic fused-ring polymer cathode. Furthermore, no obvious polarization phenomenon is observed at both high and low temperatures, indicating that the reaction kinetics of the nitrogen-aromatic fused-ring polymer are stable at different temperatures.

[0075] Figure 7 The graph shows the rate performance of an aqueous zinc-ion battery using the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1 as the cathode material at different temperatures; from 0.1 to 20 A g. -1 Within the current range, nitrogen-containing aromatic fused-ring polymer cathodes exhibit excellent rate performance at low and high temperatures. The capacity retention values ​​at 20 °C were 79.0, 85.8, 86.1, 86.8, 86.5, 83.1, 80.0, and 76.3% compared to 25 °C, showing a higher low-temperature capacity retention rate. When the current was increased from 20 Ag... -1 Restored to 0.1 Ag -1 At that time, the capacities were 50, 25, and respectively. , and The values ​​have been restored to 210, 205, 161, 143, and... This demonstrates the excellent stability and reversibility of the nitrogen-aromatic fused-ring polymer cathode at different temperatures.

[0076] Figure 8 An aqueous zinc-ion battery using the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1 as the positive electrode material at a current density of Cyclic performance graphs at different temperatures; nitrogen-aromatic fused-ring polymer cathode at 50, 25, , and The following values ​​showed satisfactory results: 164, 166, 136, 114, and... The high discharge specific capacity and impressive stability after 10,000 cycles demonstrate that this polymer possesses superior electrochemical stability and energy storage capabilities.

[0077] Figure 9 This is a comparison of the ion diffusion coefficients of an aqueous zinc-ion battery using the nitrogen-containing aromatic fused-ring polymer synthesized in Example 1 as the positive electrode material at different temperatures. The results show that at 50, 25, ... and At temperatures of [temperature value missing], the nitrogen-aromatic fused-ring polymer cathode exhibits a high and stable diffusion coefficient, ranging from [temperature value missing] to [temperature value missing]. to This demonstrates the rapid reaction kinetics and superior ion transport capabilities of PPP.

[0078] It should be noted that by changing the ratio of raw materials in different steps, this invention can obtain the nitrogen-aromatic fused-ring polymer and exhibit excellent electrochemical performance.

[0079] In summary, this invention designs an organic electrode material—a nitrogen-containing aromatic fused-ring polymer—which has high reversible capacity and rapid charge transfer capability. These characteristics make this organic electrode material show great potential when applied as a cathode material for aqueous zinc-ion batteries.

[0080] Finally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0081] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0082] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A nitrogen-containing aromatic fused-ring polymer, characterized in that, The structural formula of the nitrogen-containing aromatic fused ring polymer is as follows: ; Where n is between 3 and 100.

2. The method for preparing a nitrogen-containing aromatic fused-ring polymer as described in claim 1, characterized in that, The preparation method includes: subjecting 2,6-diaminoanthraquinone to bromination, debromination, and dehydration condensation reactions in sequence to obtain a nitrogen-containing aromatic fused-ring polymer.

3. The method for preparing a nitrogen-containing aromatic fused-ring polymer according to claim 2, characterized in that, The preparation method specifically includes: S1. Dissolve 2,6-diaminoanthraquinone and N-bromosuccinimide in an organic solvent to obtain a 2,6-diaminoanthraquinone solution and an N-bromosuccinimide solution. Add the N-bromosuccinimide solution dropwise to the 2,6-diaminoanthraquinone solution at 0±5℃. After heating, carry out the bromination reaction under an inert atmosphere. After the reaction is completed, remove the solvent. Wash and vacuum dry the crude product to obtain 2,6-diamino-1,5-bromo-anthraquinone. S2. Under an inert atmosphere, the 2,6-diamino-1,5-bromo-anthraquinone and hexanoic anhydride solution were microwave-treated at 170-190 °C for 0.5-1 h. The crude product was filtered, washed and vacuum-dried to obtain DAAQ-Br-C6. S3. The DAAQ-Br-C6, copper powder, and iodine are added to an organic solvent and heated to 120-140 °C for 18-28 h under an inert atmosphere. After the reaction is completed, the mixture is filtered, and the filtrate is poured into water to precipitate the solid. Solid-liquid separation is then performed, and the obtained solid is recrystallized with a mixed solution of tetrahydrofuran and ether. The crystals are washed and vacuum dried to obtain Pre-PPP. S4. The Pre-PPP, dilute hydrochloric acid and 1,4-dioxane are mixed and heated at 150±10 °C for 40-54 h. After cooling, solid-liquid separation is performed. The obtained solid is washed and dried to obtain a nitrogen-containing aromatic fused ring polymer. The structural formulas of DAAQ-Br-C6 and Pre-PPP are as follows: 、 。 4. The method for preparing a nitrogen-containing aromatic fused-ring polymer according to claim 3, characterized in that, In step S1, the molar ratio of 2,6-diaminoanthraquinone to N-bromosuccinimide is 1:(2-3). The inert atmosphere is argon or nitrogen; The bromination reaction was carried out at a temperature of 25±5 ℃ for 20–28 h. The crude product obtained is washed and vacuum dried, specifically including: The crude product was washed several times with water and ethanol, and then vacuum dried at 60–100 °C for 8–16 h.

5. The method for preparing a nitrogen-containing aromatic fused-ring polymer according to claim 3, characterized in that, In step S2, the molar ratio of DAAQ-Br to hexanoic anhydride is 1:(5-15), and the reaction temperature is 170-190°C. o C, reaction time is 0.5 to 1 hour; The crude product obtained is subjected to filtration, washing, and vacuum drying, specifically including: The crude product was filtered and then washed several times with water and ethanol. The washed product was then vacuum dried at 60–100 °C for 8–16 h.

6. The method for preparing a nitrogen-containing aromatic fused-ring polymer according to claim 3, characterized in that, In step S3, the molar ratio of DAAQ-Br-C6, copper powder, and iodine is 1:(1.5-3.5):(0.01-0.5). The obtained solid is recrystallized from a mixed solution of tetrahydrofuran and ether, and the crystals are washed and vacuum dried, specifically including: The obtained solid was recrystallized from a mixed solution of tetrahydrofuran and ether in a volume ratio of 1:(0.5–1.5). The crystals were washed several times with water and ethanol, and then dried under vacuum at 60–100 °C for 8–16 h.

7. The method for preparing a nitrogen-containing aromatic fused-ring polymer according to claim 3, characterized in that, In step S4, the concentration of the dilute hydrochloric acid is 1.5–2.5 mol / L; The volume ratio of 1,4-dioxane to the dilute hydrochloric acid is 1:(3-5). The obtained solid material is washed and dried to obtain a nitrogen-containing aromatic fused-ring polymer, specifically including: The obtained solid was washed sequentially with tetrahydrofuran, water and ethanol, and the washing product was vacuum dried at 60-100℃ for 8-16 h to obtain a nitrogen-containing aromatic fused ring polymer.

8. The use of the nitrogen-containing aromatic fused-ring polymer as described in claim 1 in the preparation of organic cathode materials.

9. The application of the nitrogen-containing aromatic fused-ring polymer as described in claim 1 in the preparation of aqueous zinc-ion batteries.

10. A wide-temperature-range aqueous zinc-ion battery, characterized in that, The aqueous zinc-ion battery contains a nitrogen-containing aromatic fused-ring polymer as described in claim 1.

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