Anthraquinone dimer organic positive electrode material and preparation method and application thereof

Abstract

An anthraquinone dimer type organic positive electrode material and a preparation method and application thereof belong to the field of secondary batteries. Amino compounds and ketone compounds are mixed, a condensation reaction is carried out, and a positive electrode active material is obtained. Through molecular design, small molecule monomers which are easy to dissolve are connected into dimers through covalent bonds, the dissolution of the active material in the aqueous electrolyte is effectively inhibited, and thus the cycle stability of the battery is significantly improved while the high capacity and fast kinetics advantages of the organic material are retained. Taking a water-based zinc ion battery as an example, the button cell still maintains a high capacity of 97.5 mAh g ‑1 after 10,000 mA g ‑1 of current density is cycled for 300 cycles.

Description

Technical Field

[0001] This invention relates to the field of secondary battery technology, and in particular to anthraquinone dimer-type organic cathode material, its preparation method, and its application. Background Technology

[0002] Aqueous zinc-ion batteries have shown great application potential in large-scale energy storage due to their advantages such as high safety, low cost, environmental friendliness, and abundant zinc resources. The cathode material is one of the key components determining the battery's energy density, cycle life, and power performance. Currently, cathode materials for aqueous zinc-ion batteries are mainly divided into two categories: inorganic materials and organic materials. Inorganic cathode materials (such as manganese-based oxides, vanadium-based compounds, and Prussian blue analogues) generally suffer from technical bottlenecks such as structural collapse, metal ion dissolution, poor rate performance, and weak adaptability to high and low temperatures.

[0003] Organic cathode materials, with their advantages of tunable structure, abundant resources, environmental friendliness, and high theoretical voltage, are gradually becoming a core direction for overcoming the limitations of inorganic materials. Anthraquinone compounds, due to the carbonyl (C=O) redox active sites in their molecules, can achieve reversible coordination and desorption of zinc ions, making them an important research branch of organic cathode materials. However, in current technologies, anthraquinones are mostly used as monomeric cathode active materials, which have the following prominent problems: First, the intermolecular forces of monomers are weak, making them easily dissolved and lost in aqueous electrolytes, resulting in extremely poor cycle stability; second, the monomer conjugated system is limited, resulting in insufficient electronic conductivity and difficulty in improving rate performance. In current technologies, dissolution is usually suppressed by polymerizing active units (such as covalent organic framework compounds, polymers) or combining them with insoluble skeletons. However, these methods often lead to decreased material conductivity, reduced utilization of active sites, or complex synthesis processes.

[0004] Therefore, developing an anthraquinone dimer-based organic cathode active material with a well-developed conjugated system, excellent electronic conductivity, high stability in aqueous electrolytes, long cycle life, simple preparation method, low cost, and suitability for large-scale production is of great significance for promoting the industrial application of aqueous zinc-ion batteries. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned problems in the prior art and to provide anthraquinone dimer-type organic cathode material, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An anthraquinone dimer-based organic cathode material has the following structural formula:

[0008] or

[0009] R1, R2, R3, R4, R5, and R6 are independently selected from CH3O, COOH, C≡N, H, F, Cl, Br, and I, respectively; R7 is selected from C1-C6 alkylene chains, benzene, and biphenyl. R1 to R6 may be the same or different.

[0010] The method for preparing an anthraquinone dimer organic cathode material includes the following steps: dissolving amino compounds and ketone compounds in a reaction solvent and heating under reflux; after the reaction is completed and the mixture is cooled to room temperature, vacuum filtration is performed; and finally, the filter cake is washed and dried to obtain the anthraquinone dimer organic cathode material.

[0011] The amino compounds include one or more of 1,2-diaminoanthraquinone, 1,2-diamino-7-fluoro-9,10-anthraquinone, 1,2-diamino-3-chloroanthraquinone, 1,4-diaminoanthraquinone, 1,5-diaminoanthraquinone, 1,8-diaminoanthraquinone, 2,3-diaminoanthraquinone, 2,6-diaminoanthraquinone, and 2,7-diaminoanthraquinone.

[0012] The ketone compounds include one or more of 1,4-dibromo-2,3-butanedione, 1,1'-(1,4-phenylene)bis(2-bromoethylone), 4,4'-bis(2-bromoacetyl)biphenyl, cyclohexanehexaone, cyclopentanepentone, and 1-chloro-2,3-butanedione.

[0013] The molar ratio of the amino compounds to the ketone compounds is 2 to 6:1.

[0014] The heating reflux temperature is 60 ~ 120 ℃, and the reaction time is 4 ~ 24 h.

[0015] The reaction solvent is methanol, ethanol, or acetic acid.

[0016] In this invention, the washing solvent is one or more of water, methanol, ethanol, N,N-dimethylformamide, and N-methylpyrrolidone.

[0017] The aforementioned anthraquinone dimer-type organic cathode material is used as an active material in the cathode of an ion battery.

[0018] An ion battery comprising the anthraquinone dimer-type organic cathode material described in this invention.

[0019] Compared with the prior art, the beneficial effects achieved by the technical solution of this invention are:

[0020] This invention provides an anthraquinone dimer-based organic cathode material, its preparation method, and its applications. This organic cathode material employs a dimer structure design, connecting two active units to form a complete large π-conjugated framework, resulting in improved electronic conductivity compared to monomeric materials. Simultaneously, the carbonyl and imine sites of the anthraquinone dimer synergistically enable multiple reversible coordination of zinc ions. Compared to materials with single active sites, the intermolecular forces in the dimer are significantly enhanced, effectively reducing dissolution and loss during charge and discharge, and greatly improving cycle stability at 10000 mA g. -1 After 300 cycles under current, it still maintains a capacity of 97.5 mAh g. -1 High capacity. Attached Figure Description

[0021] Figure 1 The infrared spectrum of the anthraquinone dimer-type organic cathode material obtained in Example 1 is shown below.

[0022] Figure 2 The aqueous zinc-ion battery obtained in Example 1 operates within a voltage range of 0.2 ~ 1.5 V and a current density of 50 mA g. -1 The charge / discharge curves are as follows;

[0023] Figure 3 The aqueous zinc-ion battery obtained in Example 1 operates within a voltage range of 0.2 ~ 1.5 V and a current density of 1000 mA g. -1 Long-cycle performance under these conditions;

[0024] Figure 4 The aqueous zinc-ion battery obtained in Example 1 operates within a voltage range of 0.2 ~ 1.5 V and a current density of 10000 mA g. -1 Long-cycle performance. Detailed Implementation

[0025] To make the technical problems, technical solutions and beneficial effects of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] The following two synthesis routes are given in the embodiments of the present invention.

[0027] Route 1: Reaction of 1,4-dibromo-2,3-butanedione and 1,2-diaminoanthraquinone.

[0028]

[0029] Route 2: Reaction of 1,2-diaminoanthraquinone with 1,1'-(1,4-phenylene)bis(2-bromoethylone).

[0030]

[0031] Example 1

[0032] 2.3824 g of 1,2-diaminoanthraquinone and 1.2194 g of 1,4-dibromo-2,3-butanedione were weighed and dissolved in 100 mL of methanol, and reacted at 80 °C for 16 h. After the reaction was completed and cooled to room temperature, the mixture was vacuum filtered. The obtained filter cake was washed five times with methanol and N,N-dimethylformamide solvent until the filtrate was colorless, and then dried to obtain a black solid powder, which is the organic cathode material.

[0033] Example 2

[0034] 2.3824 g of 1,2-diaminoanthraquinone and 1.599 g of 1,1'-(1,4-phenylene)bis(2-bromoethylone) were weighed and dissolved in 80 mL of methanol, and reacted at 80 °C for 12 h. After the reaction was completed and cooled to room temperature, the mixture was vacuum filtered. The filter cake was washed four times with methanol and N,N-dimethylformamide solvent until the filtrate was colorless, and then dried to obtain a black solid powder, which is the organic cathode material.

[0035] Example 3

[0036] 2.3824 g of 1,2-diaminoanthraquinone and 1.9803 g of 4,4'-bis(2-bromoacetyl)biphenyl were weighed and dissolved in 100 mL of methanol, and reacted at 80 °C for 12 h. After the reaction was completed and cooled to room temperature, the mixture was vacuum filtered. The filter cake was washed five times with methanol and N,N-dimethylformamide solvent until the filtrate was colorless and then dried to obtain a black solid powder, which is the organic cathode material.

[0037] Figure 1 The image shows the infrared spectrum of the anthraquinone dimer-type organic cathode material prepared in Example 1. The image shows the spectrum at 1658 cm⁻¹. -1 and 1468 cm -1 The peaks correspond to the absorption peaks of the carbonyl (C=O) vibration and imine (C=N) vibration in the anthraquinone dimer.

[0038] The anthraquinone dimer-type organic cathode material prepared in Example 1 was used as the active material for the cathode of a zinc-ion battery. The organic cathode material, Ketjen black, and polyvinylidene fluoride were mixed and ground in a mass ratio of 5:4:1. 2 mL of N-methylpyrrolidone was added dropwise and the mixture was ground for 30 min to obtain a uniform slurry. The slurry was then coated onto a titanium mesh current collector using a scraper and placed in a vacuum drying oven at 80 °C for 12 h. The resulting material was then cut to a diameter of 10 mm and a loading of ~1.5 mg cm⁻¹. -2 A composite positive electrode; using zinc sheet as the negative electrode, 2 mol L -1A Zn(CF3SO3)2 aqueous solution was used as the electrolyte, and glass fiber was used as the separator to assemble a CR2032 coin cell, and the electrochemical performance was tested.

[0039] Figure 2 To test the aqueous zinc-ion battery obtained in Example 1 using the Xinwei Battery Testing System and the Koster Electrochemical Workstation, constant current charge-discharge cycle tests were conducted. The voltage test range was 0.2–1.5 V, and the current density was 50 mA g. -1 The obtained charge-discharge curves are as follows: Figure 2 As shown; from Figure 2 It can be seen that the specific capacity during the first charge is 183.58 mAh g. -1 After 4 cycles, the battery's specific charging capacity is 147.78 mAh g. -1 .

[0040] Figure 3 To test the aqueous zinc-ion battery obtained in Example 1 using the Xinwei Battery Testing System and the Koster Electrochemical Workstation, constant current charge-discharge cycle tests were conducted. The voltage test range was 0.2–1.5 V, and the current density was 1000 mA g. -1 ;from Figure 3 It can be seen that the specific capacity during the first charge cycle is 146.81 mAh g. -1 The battery's specific charge capacity after 100 cycles is 118.5 mAh g. -1 It exhibits good cyclic stability.

[0041] Figure 4 To test the aqueous zinc-ion battery obtained in Example 1 using the Newway Battery Testing System and the Koster Electrochemical Workstation, constant current charge-discharge cycle tests were conducted. The voltage test range was 0.2–1.5 V, and the current density was 10,000 mA g. -1 ;from Figure 4 It can be seen that the specific capacity during the first charge cycle is 100.8 mAh g. -1 The battery's specific charge capacity after 300 cycles is 97.5 mAh g. -1 It exhibits good cyclic stability.

Claims

1. An anthraquinone dimer-based organic cathode material, characterized in that, The structure is as follows: or Among them, R1, R2, R3, R4, R5, and R6 are independently selected from CH3O, COOH, C≡N, H, F, Cl, Br, and I, respectively; R7 is selected from C1~C6 alkylene chains, benzene, and biphenyl.

2. The method for preparing anthraquinone dimer-type organic cathode material according to claim 1, characterized in that, The process includes the following steps: dissolving amino compounds and ketone compounds in a reaction solvent and heating under reflux; after the reaction is complete and the mixture is cooled to room temperature, vacuum filtration is performed; and finally, the filter cake is washed and dried to obtain the anthraquinone dimer-type organic cathode material.

3. The preparation method according to claim 2, characterized in that: The amino compounds include one or more of 1,2-diaminoanthraquinone, 1,2-diamino-7-fluoro-9,10-anthraquinone, 1,2-diamino-3-chloroanthraquinone, 1,4-diaminoanthraquinone, 1,5-diaminoanthraquinone, 1,8-diaminoanthraquinone, 2,3-diaminoanthraquinone, 2,6-diaminoanthraquinone, and 2,7-diaminoanthraquinone.

4. The preparation method according to claim 2, characterized in that: The ketone compounds include one or more of 1,4-dibromo-2,3-butanedione, 1,1'-(1,4-phenylene)bis(2-bromoethylone), 4,4'-bis(2-bromoacetyl)biphenyl, cyclohexanehexaone, cyclopentanepentone, and 1-chloro-2,3-butanedione.

5. The preparation method according to claim 2, characterized in that: The molar ratio of the amino compounds to the ketone compounds is 2 to 6:

1.

6. The preparation method according to claim 2, characterized in that: The heating reflux temperature is 60 ~ 120 ℃, and the reaction time is 4 ~ 24 h.

7. The preparation method according to claim 2, characterized in that: The reaction solvent is methanol, ethanol, or acetic acid.

8. The preparation method according to claim 2, characterized in that: The solvent used for washing is one or more of water, methanol, ethanol, N,N-dimethylformamide, and N-methylpyrrolidone.

9. The application of the anthraquinone dimer-type organic cathode material according to claim 1, characterized in that: Active material used as the positive electrode in ion batteries.

10. An ion battery, characterized in that: This includes the anthraquinone dimer-type organic cathode material as described in claim 1.

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