Quinolizine organic electrode material with multiple active sites, preparation method and application thereof

Abstract

The application belongs to the field of aqueous metal-ion battery electrode materials, and particularly relates to a quinonizine organic electrode material with multiple active sites and a preparation method and application thereof. In a nitrogen atmosphere, dihydroxyphenazine is synthesized, then is fully ground with an o-phenylenediamine derivative, and is sintered in a tube furnace to obtain an intermediate after cooling and washing. The intermediate is oxidized under acidic conditions to obtain a product. The quinonizine compound has multiple carbon-nitrogen double bonds and carbon-oxygen double bonds in the molecular structure, and the redox active sites are rich and uniformly dispersed. The quinonizine compound realizes high specific capacity, high material utilization, excellent rate performance and cycle stability; meanwhile, the quinonizine compound reduces the solubility of the compound by expanding the molecules with a conjugated structure, and solves the problem of battery stability caused by the easy dissolution of the organic electrode material in the electrolyte. An aqueous zinc-ion battery with high capacity, good cycle stability and high energy storage density is constructed.

Description

Technical Field

[0001] This invention belongs to the field of electrode materials for aqueous metal-ion batteries, specifically relating to a quinone-azine organic electrode material with multiple active sites, its preparation method, and its application. Background Technology

[0002] Over the past two decades, the rapid increase in fossil fuel consumption and its negative environmental impact has spurred the exploration of renewable energy sources and more efficient energy storage technologies. This rapidly growing demand has fueled the development of high-performance energy storage batteries. Lithium-ion batteries, with their extremely high energy density, excellent cycle performance, and superior voltage platform, quickly captured the energy storage device market upon commercialization. However, the organic electrolytes used in lithium-ion batteries are toxic, costly, and resource-limited, failing to meet the enormous market demand. Aqueous zinc-ion batteries, due to their inherent safety, high theoretical capacity, and environmental friendliness, have become a research hotspot.

[0003] Current research on electrode materials for aqueous zinc-ion batteries mainly focuses on inorganic materials, which possess advantages such as high capacity, high energy density, and high power density. However, they also have many problems, such as resource scarcity, environmental pollution, complex synthesis, and high energy consumption during processing. Furthermore, due to the rigid structure of inorganic materials, the insertion / extraction of cations during cycling can lead to volume expansion, phase transitions, and in severe cases, structural collapse, resulting in capacity decay. These issues make it difficult to achieve further breakthroughs in the performance of inorganic materials for electrodes.

[0004] Compared to electrodeless materials, organic materials are simpler to synthesize, easier to scale up, and less expensive. Furthermore, the diverse structures of organic materials allow for simple molecular engineering modifications to enhance their electrochemical performance. Based on their active sites, commonly used organic electrode materials can be divided into two categories: quinones and imines. Quinones are stable, inexpensive, and abundant, exhibiting high discharge capacity and low polarizability. However, small quinone molecules are readily soluble in organic electrolytes, affecting their cycle stability. Wang's team discovered that a pyrene-4,5,9,10-tetraone (PTO) cathode with a tetracarbonyl group and planar conjugated structure exhibits high discharge capacity at a current density of 0.04 A g. -1 At that time, it can provide 336mAh g -1 Specific capacity. (Using 3Ag) -1After 1000 cycles at the specified current density, the battery retained 70% of its capacity (Angew. Chem. Int. Ed. 57, 11737–11741 (2018)). The lone pair electrons of nitrogen atoms in imine-based materials can enhance redox activity and improve dissolution resistance, but their structural design is inherently limited, significantly restricting the research of higher capacity materials. Huang et al. found that the capacity of 1,4,5,8-naphthalenedimide (NDI) layered molecules as the cathode was only 200 mAh g⁻¹. -1 [J. Power Sources 482, 228904 (2021)]. Wang et al. found that the imine-based material TAP / Ti3C2Tx cathode can provide 303 mAh g at a current density of 0.04 Ag⁻¹. -1 The reversible capacity [Adv.Mater.34,2206812(2022).].

[0005] To enhance the solubility of quinone materials, new active groups have been added. Nitrogen-based active compounds are widely used as electrochemically active materials due to their abundant storage sites and large insoluble framework. The electronegativity of nitrogen (N) lies between that of carbon (C) and oxygen (O), which can improve both electronic conductivity and redox potential. In recent years, an increasing number of materials have simultaneously possessed electroactive carbonyl and imine groups in their molecular structures; these materials are called quinazons. The carbonyl and imine groups in quinazons have similar redox mechanisms and potentials, and integration within the same conjugated system is an effective strategy to improve theoretical capacity, redox potential, or both simultaneously. The fusion of quinone molecules with pyrazine units can extend the number of aromatic core units, thereby reducing molecular solubility and increasing specific capacity. However, existing quinazons suffer from an overly dense concentration of active sites, leading to underutilization of capacity. For example, the quinazon structure BBQPH proposed by Liu et al. has a theoretical specific capacity of 567 mAh g⁻¹. -1 However, the actual specific capacity is 490mAh g. -1 The material utilization rate is only 86.4%, and the recycling performance is weak, which needs to be further improved (Nat.Commun.14,5235(2023)). Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing and applying a conjugated quinone azine organic electrode material with uniformly dispersed multi-redox active sites, diverse structures, and stability. The raw materials for this material are readily available, the synthesis method is simple, it is easy to scale up, and the yield is high. Furthermore, this material provides multiple electrochemical active sites and a uniform, highly conjugated structural system, which can overcome the shortcomings of low capacity and utilization rate of existing organic electrode materials, and has broad application prospects.

[0007] The conjugated quinazine organic electrode material provided by this invention, which has uniformly dispersed multiple redox active sites and a diverse and stable structure, is selected from one of the following: benzo[b]quinoxolino[2,3-i]phenazine-6,8,13,15-tetraone (I), pyrazino[2,3-b:5,6-b']dibenzo-6,17-dione (II), and 6a,20a-pyrazino[2,3-b]pyrazino[2',3':6,7]quinoxolino[2,3-i]phenazine-6,8,10,17,19,21-hexanone (III).

[0008]

[0009] This invention also provides a method for preparing conjugated quinazine organic electrode materials: firstly, an intermediate product is obtained by an amidation reaction, and then an oxidation method is used under supercritical conditions to obtain quinazine organic electrode materials with multiple active sites;

[0010] The intermediate product is prepared by an amidation reaction of dihydroxyphenazine and o-phenylenediamine derivative or an amidation reaction of dihydroxyphenazine and 2,3-diaminophenazine.

[0011] The preparation steps for synthesizing conjugated quinone azine-based organic electrode materials using dihydroxyphenazine and o-phenylenediamine derivatives are as follows:

[0012] (1) First, using commercial naphthoquinone derivatives and potassium phthalimide as raw materials, acetonitrile solution was added and the mixture was stirred and refluxed for 12 h under a nitrogen atmosphere. After hot filtration and washing, hydrazine hydrate was added for reduction, and after washing and vacuum drying, solid o-phenylenediamine derivatives were obtained.

[0013] The molar ratio of naphthoquinone derivatives to potassium phthalimide is 1:2 to 1:4.5, and the naphthoquinone derivatives are selected from 2,3-dichloro-1,4-naphthoquinone or tetrachloronaphthoquinone.

[0014] (2) Weigh o-phenylenediamine and p-hydroxybenzoquinone, then add H2O as a solvent, heat the mixture to 110°C under a nitrogen atmosphere, and continuously reflux and stir for 10-12 h. After the reaction is complete, cool to room temperature, filter to remove the solvent, wash with water, and vacuum dry to obtain a black powder, namely dihydroxyphenazine.

[0015] The molar ratio of o-phenylenediamine to p-hydroxybenzoquinone is 1:1 to 1:1.5.

[0016] (3) Using the dihydroxyphenazine prepared in step (2) and the o-phenylenediamine derivative prepared in step (1) as raw materials, grind them until fully mixed, and heat them at 200-400℃ for 4-6 hours to obtain the intermediate product;

[0017] The molar ratio of dihydroxyphenazine to o-phenylenediamine derivative is 1:1 to 1:1.5;

[0018] (4) Conjugated quinazine organic electrode materials were prepared by supercritical fluid method.

[0019] The preparation steps for synthesizing quinone-azine-based organic electrode materials by reacting dihydroxyphenazine and 2,3-diaminophenazine are as follows:

[0020] (1) Dissolve o-phenylenediamine in water and add ferric chloride, with a molar ratio of 5:4. Heat the solution at 60°C for 20 min with constant stirring. After standing, filter and wash with pure water until the filtrate is colorless. Then dry the filter cake at 80°C for 12 h to obtain the orange-red product 2,3-diaminophenazine;

[0021] (2) Weigh o-phenylenediamine and p-hydroxybenzoquinone, then add H2O as solvent, heat the mixture to 110°C under nitrogen atmosphere, and continuously reflux and stir for 10-12 h. After the reaction is completed, cool to room temperature, filter to remove solvent, wash with water, and vacuum dry to obtain black powder, i.e. dihydroxyphenazine.

[0022] The molar ratio of o-phenylenediamine to p-hydroxybenzoquinone is 1:1 to 1:1.5.

[0023] (3) Using the dihydroxyphenazine prepared in step (2) and the 2,3-diaminophenazine prepared in step (1) as raw materials, grind them until fully mixed, and heat them to react to obtain a brown intermediate product;

[0024] The molar ratio of 2,3-diaminophenazine to dihydroxyphenazine is 1:1;

[0025] (4) The intermediate product prepared in step (3) is used to prepare quinone azine organic electrode material with multiple active sites by supercritical fluid method.

[0026] The specific preparation process of quinone-azine organic electrode materials with multiple active sites using the supercritical fluid method is as follows:

[0027] The black or brown intermediate product prepared in step (3) was added to 100 mL of anhydrous ethanol and sonicated for 1 h to form a homogeneous dispersion. K₂Cr₂O₇ was then added, and the mixture was sealed in a 0.5 L stainless steel autoclave. The autoclave temperature was steadily increased to 30 °C, and CO₂ was introduced into the autoclave to bring the pressure inside to 6 MPa. The autoclave temperature was then slowly increased to 130 °C while stirring at 300 r / min, allowing the reaction system to reach a supercritical state. After the reaction continued for 3–6 h, the autoclave was cooled to room temperature, and CO₂ was slowly released. The product was then removed. After multiple washings and centrifugation, the product was vacuum dried at 80 °C to obtain a yellow solid product.

[0028] The aforementioned conjugated quinone azine organic electrode materials are used to prepare electrode materials for aqueous zinc-ion batteries.

[0029] The preparation method of the aqueous zinc-ion battery electrode material is as follows: Conjugated quinone azine organic electrode material, conductive additives, and binders are uniformly dispersed in a solvent and coated onto a current collector, followed by vacuum drying to obtain an organic positive electrode. The mass ratio of the conjugated quinone azine organic electrode material, conductive additives, and binders is 4–7:3–6:1.

[0030] The solvent is isopropanol or N-methyl-2-pyrrolidone (NMP), the current collector is 300-mesh stainless steel mesh, titanium mesh, carbon paper, aluminum foil or copper foil, the vacuum drying temperature is 60-80℃, and the drying time is 12-18h.

[0031] The assembly process of an aqueous zinc-ion battery is as follows: button cells are assembled in the following order: anode shell, spring, gasket, zinc sheet, glass fiber separator, electrolyte, cathode sheet, and cathode shell. The assembled batteries are then sealed under high pressure using a button cell sealing machine and allowed to stand at room temperature until fully impregnated with the electrolyte, thus obtaining the zinc-ion battery.

[0032] Beneficial effects: This invention designs a structurally diverse and stable conjugated quinone azine organic electrode material with multiple redox active sites and a uniform large π conjugated structure. Aqueous zinc-ion batteries assembled with this material have excellent actual specific capacity, material utilization, rate performance and cycle performance. Attached Figure Description

[0033] Figure 1 This is the 1H NMR spectrum of the organic electrode material I prepared in Example 1;

[0034] Figure 2 The charge and discharge diagrams are of an aqueous zinc-ion battery assembled using the organic electrode material prepared in Example 1.

[0035] Figure 3 The battery assembled in Example 1 was used at a current density of 5 A g. -1 The following is a charge / discharge cycle life diagram;

[0036] Figure 4 The infrared spectrum of compound I, benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone, from Example 2 is shown.

[0037] Figure 5 The battery assembled for Example 2 operates at a current density of 0.05 A g. -1 The following is a charge / discharge cycle life diagram;

[0038] Figure 6 The battery assembled for Example 3 was tested at a current density of 0.05 A g.-1 The following is a charge / discharge cycle life diagram;

[0039] Figure 7 The battery assembled for Example 4 operates at a current density of 0.05 A g. -1 The following is a charge / discharge cycle life diagram;

[0040] Figure 8 The battery assembled for control example 1 was used at a current density of 0.1 A g. -1 The following is a charge / discharge cycle life diagram;

[0041] Figure 9 The battery assembled for control example 1 was used at a current density of 5 A g. -1 The following is a charge / discharge cycle life diagram. Detailed Implementation

[0042] The present invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0043] Example 1: The synthesis route of organic electrode material I is as follows:

[0044]

[0045] (1) Weigh 10.07 g (45 mmol) of 2,3-dichloro-1,4-naphthoquinone and 16.70 g (90 mmol) of potassium phthalimide, add 150 ml of acetonitrile solution, and heat in an oil bath to 80 °C under a nitrogen atmosphere, stirring and refluxing for 12 h. After the reaction is complete, immediately filter the hot product, and then wash it with 500 ml of 80 °C hot water and 200 ml of ethanol, respectively. The resulting filter cake is a yellow solid 2,2'-(1,4-dioxane-1,4-dione-2,3-diyl)bis(isoindoline-1,3-dione) (TPB). Then dry the product under vacuum at 60 °C for 12 h. Add 16 g of TPB and 150 ml of hydrazine hydrate to a 250 ml single-necked flask, heat in an oil bath to 60 °C, and reflux for 12 h. After the reactants were cooled to room temperature, the product was filtered and washed 10 times with ultrapure water until the filtrate was colorless. The product was then dried under vacuum at 60°C for 12 hours to obtain a dark purple solid, 2,3-diamino-1,4-naphthoquinone.

[0046] (2) Weigh 0.5407 g (5 mmol) of o-phenylenediamine and 0.7 g (5 mmol) of p-hydroxybenzoquinone, then add 50 ml of H2O as a solvent. Heat the mixture to 110 °C under a nitrogen atmosphere and stir continuously under reflux for 12 h. After the reaction is complete, cool to room temperature, filter the suspension, wash the filter cake with water, and dry it under vacuum at 80 °C for 12 h to finally obtain 0.576 g of black powder, namely 2,3-dihydroxyphenazine.

[0047] (3) Grind 0.429 g (2 mmol) of 2,3-diamino-1,4-naphthoquinone and 0.377 g (2 mmol) of 2,3-dihydroxyphenazine in an agate mortar for 20 min until thoroughly mixed. Then transfer the mixture to a porcelain boat and place it in a tube furnace, heating at 400 °C for 4 h under a nitrogen atmosphere. After the reaction is complete, cool to room temperature and add 40 ml of acetone to prepare a slurry. Filter and wash with 1-methylpyrrolidone (NMP) and ethanol successively until colorless, and then dry at 80 °C for 18 h to obtain a black intermediate product.

[0048] (4) The black intermediate product (0.63 g, 1.7 mmol) prepared in step (3) was added to 100 mL of anhydrous ethanol and sonicated for 1 h to form a homogeneous dispersion. Then, 4 g (13.6 mmol) of K2Cr2O7 was added, and the mixture was sealed in a 0.5 L stainless steel autoclave. The temperature of the autoclave was steadily increased to 30 °C, and CO2 was introduced into the autoclave to bring the pressure inside the autoclave to 6 MPa. Under stirring at 300 r / min, the temperature of the autoclave was slowly increased to 130 °C to bring the reaction system to a supercritical state. After the reaction continued for 6 h, the autoclave was cooled to room temperature, and CO2 was slowly released. The product was then removed. After washing 10 times and centrifuging, the product was vacuum dried at 80 °C to finally obtain the yellow solid product benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone. The yield was 92.3%.

[0049] The above-mentioned solid product, benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone, conductive additives, and binders were uniformly dispersed in the solvent N-methyl-2-pyrrolidone (NMP) and coated (1.5 mg / cm³). 2 The organic positive electrode was obtained by vacuum drying on a stainless steel mesh current collector for 12 hours. The mass ratio of benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone, conductive additive, and binder was 6:3:1. Button cells were assembled in the following order: anode shell, spring, gasket, zinc sheet, glass fiber separator, electrolyte, cathode sheet (the organic electrode material synthesized in this invention), and cathode shell. The assembled cells were sealed under high pressure using a button cell encapsulation machine and allowed to stand at room temperature until fully impregnated with the electrolyte, thus obtaining a zinc-ion battery.

[0050] Figure 1 This is the 1H NMR spectrum of compound I, benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone, from Example 1. It can be seen that compound I exhibits corresponding 1H NMR peaks at 8.51, 8.37, 8.20, and 8.05 ppm.

[0051] Figure 2 The battery assembled for Example 1 operates at a current density of 0.05 A g. -1 The charge-discharge curves were obtained, with a voltage test window of 0.2V–1.5V. As can be seen from the figure, this organic electrode material exhibits a high specific capacity (487 mAh g⁻¹). -1 The cathode material exhibits excellent electrochemical reversibility, demonstrating a discharge plateau of approximately 1.1V and 0.8V, and close to 100% coulombic efficiency. Furthermore, it demonstrates good material utilization (91.9%).

[0052] Figure 3 The battery assembled in Example 1 was used at a current density of 5 A g. -1 The graph shows the charge-discharge cycle life at a current density of 5A g. -1 At this point, the discharge capacity of the assembled battery is 365mAh g. -1 ; with 0.05Ag -1 Compared to the previous discharge capacity, even with a 100-fold increase in discharge current density, the discharge capacity still maintains 74.9%, indicating that the battery has good discharge rate capability; after 1000 cycles, the discharge capacity is 337 mAh g. -1 The capacity retention rate is 92.3%; after 5000 battery cycles, the discharge capacity is 318 mAh g. -1 The capacity retention rate was 87.1%.

[0053] Example 2: The synthesis route of organic electrode material I is the same as in Example 1. The specific preparation process is as follows:

[0054] (1) Weigh 10.07 g (45 mmol) of 2,3-dichloro-1,4-naphthoquinone and 16.70 g (90 mmol) of potassium phthalimide, add 150 ml of acetonitrile solution, and heat in an oil bath to 80 °C under a nitrogen atmosphere, stirring and refluxing for 12 h. After the reaction is complete, immediately filter the hot product, and then wash it with 500 ml of 80 °C hot water and 200 ml of ethanol, respectively. The resulting filter cake is a yellow solid 2,2'-(1,4-dioxane-1,4-dione-2,3-diyl)bis(isoindoline-1,3-dione) (TPB). Then dry the product under vacuum at 60 °C for 12 h. Add 16 g of TPB and 150 ml of hydrazine hydrate to a 250 ml single-necked flask, heat in an oil bath to 60 °C, and reflux for 12 h. After the reactants were cooled to room temperature, the product was filtered and washed 10 times with ultrapure water. The product was then dried under vacuum at 60°C for 12 hours to obtain a dark purple solid, 2,3-diamino-1,4-naphthoquinone.

[0055] (2) Weigh 0.5407 g (5 mmol) of o-phenylenediamine and 1.05 g (7.5 mmol) of p-hydroxybenzoquinone, then add 50 ml of H2O as a solvent. Heat the mixture to 110 °C under a nitrogen atmosphere and stir continuously under reflux for 12 h. After the reaction is complete, cool to room temperature, filter the suspension, wash the filter cake with water, and dry it under vacuum at 80 °C for 12 h to finally obtain 0.576 g of black powder, namely 2,3-dihydroxyphenazine.

[0056] (3) Grind 0.429 g (2 mmol) of 2,3-diamino-1,4-naphthoquinone and 0.566 g (3 mmol) of 2,3-dihydroxyphenazine in an agate mortar for 20 min until thoroughly mixed. Then transfer the mixture to a porcelain boat and place it in a tube furnace, heating at 200 °C for 6 h under a nitrogen atmosphere. After the reaction is complete, cool to room temperature and add 40 ml of acetone to prepare a slurry. Filter and wash with 1-methylpyrrolidone (NMP) and ethanol successively until colorless, and then dry at 80 °C for 18 h to obtain a black intermediate product.

[0057] (4) The black intermediate product (0.635 g, 1.71 mmol) prepared in step (3) was added to 100 mL of anhydrous ethanol and sonicated for 1 h to form a homogeneous dispersion. Then, 4 g (13.6 mmol) of K2Cr2O7 was added, and the mixture was sealed in a 0.5 L stainless steel autoclave. The temperature of the autoclave was steadily increased to 30 °C, and CO2 was introduced into the autoclave to bring the pressure inside the autoclave to 6 MPa. Under stirring at 300 r / min, the temperature of the autoclave was slowly increased to 130 °C to bring the reaction system to a supercritical state. After the reaction continued for 6 h, the autoclave was cooled to room temperature, and CO2 was slowly released. The product was then removed. After washing 10 times and centrifuging, the product was vacuum dried at 80 °C to finally obtain the yellow solid product benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone. The yield was 91.3%.

[0058] The above-mentioned solid product, benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone, conductive additives, and binders were uniformly dispersed in the solvent N-methyl-2-pyrrolidone (NMP) and coated (1.5 mg / cm³). 2 Organic positive electrode was obtained by vacuum drying on a stainless steel mesh current collector for 12 hours. The mass ratio of benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone, conductive additive, and binder was 6:3:1. Button cells were assembled in the following order: anode shell, spring, gasket, zinc sheet, glass fiber separator, electrolyte, cathode sheet, and cathode shell. The assembled cells were sealed under high pressure using a button cell packaging machine and allowed to stand at room temperature until fully impregnated with the electrolyte, thus obtaining a zinc-ion battery.

[0059] Figure 4 This is the infrared spectrum of compound I, benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone, from Example 2. As can be seen from the figure, compound I has an infrared spectrum at 1710 cm⁻¹. -1 With 1590cm -1 There are two sets of very strong absorption vibration peaks at 3490 cm⁻¹, which are attributed to C=O and CN bonds within the ring, respectively. -1 The absorption vibration peak at that point is attributed to the OH bond in the water peak.

[0060] Figure 5 The battery assembled for Example 2 operates at a current density of 0.05 A g. -1 The graph shows the charge-discharge cycle life at a current density of 0.05 A g. -1 At this point, the discharge capacity of the assembled battery is 469 mAh g. -1 The utilization rate of electrode materials is 88.5%; after 1000 battery cycles, the discharge capacity is 437 mAh g. -1 The capacity retention rate is 93.2%; after 2000 battery cycles, the discharge capacity is 423 mAh g. -1 The capacity retention rate was 90.2%.

[0061] Example 3: The synthesis route of organic electrode material II is as follows:

[0062]

[0063] (1) Add 5.407 g (50 mmol) of o-phenylenediamine to a 1000 ml beaker, then add 600 ml of water, heat to 60 °C, stir until completely dissolved, then add 6.488 g of ferric chloride, add ultrapure water to 1000 ml, stir for 20 min, let stand overnight, then discard the supernatant, add ultrapure water to 1000 ml again, let stand for 12 h, repeat three times. Wash with ultrapure water until the filtrate is colorless, then dry the filter cake at 80 °C for 12 h to obtain the orange-red product 2,3-diaminophenazine;

[0064] (2) The preparation process of 2,3-dihydroxyphenazine is the same as in Example 1;

[0065] (3) Grind 0.4244 g (2 mmol) of 2,3-diaminophenazine and 0.4205 g (2 mmol) of 2,3-dihydroxyphenazine in an agate mortar for 20 min until thoroughly mixed. Then transfer the mixture to a porcelain boat and place it in a tube furnace. Heat at 300 °C for 4 h under a nitrogen atmosphere. After the reaction is complete, cool to room temperature and add 40 ml of acetone to prepare a slurry. Filter and wash with acetone and ultrapure water until colorless, and then dry at 80 °C for 18 h to obtain a brown intermediate product.

[0066] (4) The brown intermediate product (0.386 g, 1 mmol) from step (3) was dissolved in 100 mL of glacial acetic acid and sonicated for 1 h to form a homogeneous dispersion. Then, K2Cr2O7 (2.942 g, 10 mmol) was added. The mixture was then sealed in a 0.5 L stainless steel autoclave, and the temperature of the autoclave was steadily increased to 30 °C. CO2 was then introduced into the autoclave to bring the pressure inside to 6 MPa. The autoclave was slowly heated to 130 °C while stirring at 300 r / min to bring the reaction system to a supercritical state. After the reaction continued for 6 h, the autoclave was cooled to room temperature, and CO2 was slowly released. The product was then removed. After washing 10 times and centrifuging, the product was vacuum dried at 80 °C to finally obtain the yellow solid product pyrazino[2,3-b:5,6-b']dibenzo-6,17-dione, with a yield of 90.2%.

[0067] Figure 6 The battery assembled for Example 3 was tested at a current density of 0.05 A g. -1 The graph shows the charge-discharge cycle life at a current density of 0.05 A g. -1 At that time, the discharge capacity of the assembled battery was 532 mAh g. -1 The battery material utilization rate is 87.2%; after 1000 battery cycles, the discharge capacity is 485 mAh g. -1 The capacity retention rate is 91.2%; after 5000 battery cycles, the discharge capacity is 457 mAh g. -1 The capacity retention rate was 85.9%.

[0068] Example 4: The synthesis route of organic electrode material III is as follows:

[0069]

[0070] (1) First, add 6 g (24.4 mmol) tetrachloronaphthoquinone and 20 g (108 mmol) potassium phthalimide to a 250 ml three-necked round-bottom flask, then add 150 ml acetonitrile solution. Under a nitrogen atmosphere, heat in an oil bath to 80 °C and stir under reflux for 12 h. Filter and wash with 500 ml of 80 °C hot water and 200 ml of ethanol. The resulting filter cake is a yellow solid 2,2',2”,2”'-(3,6-dioxocyclohexane-1,4-diene-1,2,4,5-tetrayl)tetra(isoindole-1,3-dione) (TCB), which is dried under vacuum at 60 °C for 12 h. Add 6 g TCB, 30 ml hydrazine hydrate, and 10 ml ultrapure water to a 50 ml single-necked flask and heat in an oil bath to 70 °C for 4 h. The reactants were filtered while hot and washed 10 times with ultrapure water. The product was dried under vacuum at 80°C for 12 h to obtain a silvery-purple solid, 2,3,5,6-tetraaminobenzoquinone.

[0071] (2) The preparation process of 2,3-dihydroxyphenazine is the same as in Example 1;

[0072] (3) Grind 0.4244 g (2 mmol) of 2,3-diaminophenazine and 0.336 g (2 mmol) of tetraaminobenzoquinone in an agate mortar for 20 min until thoroughly mixed. Then transfer the mixture to a porcelain boat and place it in a tube furnace. Heat at 300 °C for 4 h under a nitrogen atmosphere. After the reaction is complete, cool to room temperature and add 40 ml of acetone to prepare a slurry. Filter and wash with acetone and ultrapure water until colorless, and then dry at 80 °C for 18 h to obtain a brown intermediate product.

[0073] (4) Dissolve the brown intermediate product (0.520 g, 1 mmol) from step (3) in 30 mL of glacial acetic acid and sonicate for 1 h to form a homogeneous dispersion. Then add K2Cr2O7 (4.412 g, 15 mmol), and seal the mixture in a 0.5 L stainless steel autoclave. Steadily raise the temperature of the autoclave to 30 °C, and then charge CO2 into the autoclave to bring the pressure inside the autoclave to 6 MPa. Then, while stirring at 300 r / min, slowly raise the temperature of the autoclave to 130 °C to bring the reaction system to a supercritical state. After the reaction continues for 6 h, cool the autoclave to room temperature, slowly release CO2, and remove the product. After washing 10 times and centrifuging, the product was vacuum dried at 80°C for 18 h to finally obtain the yellow needle-like crystalline product 6a,20a-pyrazino[2,3-b]pyrazino[2',3':6,7]quinoxalino[2,3-i]phenazine-6,8,10,17,19,21-hexanone. The yield was 88.7%.

[0074] In addition to being used as cathode materials in zinc-ion batteries, quinone-azine multi-active-site organic materials are also used in aqueous or organic lithium, sodium, potassium, magnesium, and aluminum-ion batteries.

[0075] Organic electrode material ⅠII 6a,20a-pyrazino[2,3-b]pyrazino[2',3':6,7]quinoxalino[2,3-i]phenazine-6,8,10,17,19,21-hexanone was used as the positive electrode material for aqueous zinc-ion batteries. Preparation of the organic positive electrode for zinc-ion batteries: The organic positive electrode material, Ketjen black, and polytetrafluoroethylene (mass ratio 4.5:4.5:1) were uniformly dispersed in NMP, uniformly coated onto carbon paper, and then vacuum dried at 60°C for 4 h, followed by drying at 120°C overnight to obtain the organic positive electrode. Using the organic positive electrode, a zinc sheet as the negative electrode, a glass fiber membrane as the separator, and a 2M ZnSO4 solution as the electrolyte, a zinc-ion battery was assembled. The voltage testing window was 0.2V–1.5V. The assembled zinc-ion battery was allowed to stand for 24 h before electrochemical testing.

[0076] Figure 7 The battery assembled for Example 4 operates at a current density of 0.05 A g. -1 The graph shows the charge-discharge cycle life at a current density of 0.05 A g. -1 At that time, the discharge capacity of the assembled battery was 569 mAh g. -1 The battery material utilization rate is 87.5%; after 1000 battery cycles, the discharge capacity is 502 mAh g. -1 The capacity retention rate is 88.2%; after 5000 battery cycles, the discharge capacity is 469 mAh g. -1 The capacity retention rate was 82.4%.

[0077] Comparative Example 1: Preparation of benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone by liquid phase method

[0078] (1) The preparation process of 2,3-diamino-1,4-naphthoquinone and 2,3-dihydroxyphenazine is the same as in Example 1;

[0079] (2) Using an agate pestle and mortar, mix 0.429 g (2 mmol) of 2,3-diamino-1,4-naphthoquinone and

[0080] 0.377 g (2 mmol) of 2,3-dihydroxyphenazine was ground in an agate mortar for 20 min until thoroughly mixed. The mixture was then transferred to a porcelain boat and placed in a tube furnace, where it was heated at 280 °C for 4 h under a nitrogen atmosphere. After the reaction was complete, the mixture was cooled to room temperature and 40 mL of acetone was added to prepare a slurry. The slurry was washed successively with 1-methylpyrrolidone (NMP) and ethanol until colorless, and then dried at 80 °C for 18 h to obtain a dark purple intermediate.

[0081] (3) The above-mentioned dark purple intermediate product (0.623 g, 1.7 mmol) was dissolved in 30 mL of glacial acetic acid, and then K2Cr2O7 (4 g, 13.6 mmol) was added. The mixture was stirred and heated at 130 °C for 4 h. After the reaction was completed, the mixture was cooled to room temperature. The suspension was filtered, the filter cake was washed with 1 M H2SO4, and dried under vacuum at 80 °C for 18 h to finally obtain the yellow needle-like crystal product benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone.

[0082] Figure 8 The zinc-ion battery assembled as a control example 1 operates at a current density of 0.1 A g. -1 The following is a cycle life graph. The initial capacity is 375 mAh g. -1 After 100 cycles, the organic zinc-ion battery still retains a capacity of 264 mAh g. -1 The capacity retention rate was 70.4%.

[0083] Figure 9 The organic zinc-ion battery assembled in Comparative Example 1 operates at a current density of 5.0 A g. -1 The following is a cycle life graph. After 5000 cycles, the capacity of the organic zinc-ion battery still remains at 100 mAh g. -1 The capacity retention rate was approximately 61.2%.

[0084] Compare with Example 2:

[0085] 0.6407 g (4 mmol) of 2,3-dihydroxynaphthalene and 0.432 g (4 mmol) of o-phenylenediamine were ground in an agate mortar until thoroughly mixed. The mixture was then stirred and heated at 170 °C for 3 h under a nitrogen atmosphere. After cooling to room temperature, 40 mL of acetone was added to form a slurry. The slurry was washed several times with deionized water and acetone, and then dried under vacuum at 80 °C for 18 h to obtain a yellow solid.

[0086] The obtained yellow solid (0.1161 g, 0.5 mmol) was dissolved in 15 mL of glacial acetic acid, and K₂Cr₂O₇ (0.8825 g, 3 mmol) was added. The mixture was stirred and heated at 130 °C for 3 h, and then cooled to room temperature after the reaction was complete. The suspension was filtered, the filter cake was washed with deionized water and acetone, and then dried under vacuum at 80 °C for 18 h to finally obtain a yellow needle-like crystalline product with a yield of 86.1%. The capacity of the aqueous zinc-ion battery assembled with this material was 282 mAh g⁻¹. -1 .

Claims

1. An application of a quinone-azine-based organic electrode material with multiple active sites, characterized in that, The quinazine-based organic electrode material with multiple active sites is used to prepare electrode materials for aqueous zinc-ion batteries; the quinazine-based organic electrode material with multiple active sites is selected from one of benzo[b]quinoxalino[2,3-i]phenazine-6,8,13,15-tetraone (I), pyrazino[2,3-b:5,6-b']dibenzo-6,17-dione (II), and 6a,20a-pyrazino[2,3-b]pyrazino[2',3':6,7]quinoxalino[2,3-i]phenazine-6,8,10,17,19,21-hexanone (III). 。 2. The application of the quinone-azine organic electrode material with multiple active sites according to claim 1, characterized in that, The method for preparing the aqueous zinc-ion battery electrode material is as follows: the quinone azine organic electrode material, conductive additive and binder are uniformly dispersed in a solvent and coated on the current collector, and vacuum dried to obtain the organic positive electrode; the mass ratio of the quinone azine organic electrode material, conductive additive and binder is 4~7:3~6:

1.

3. The application of the quinone-azine organic electrode material with multiple active sites according to claim 2, characterized in that... The assembly process of the aqueous zinc-ion battery is as follows: button batteries are assembled in the order of anode shell, spring, gasket, zinc sheet, glass fiber diaphragm, electrolyte, cathode sheet and cathode shell; the assembled batteries are sealed under high pressure using a button battery packaging machine and left to stand at room temperature until the electrolyte is fully impregnated, thus obtaining the zinc-ion battery.

4. The application of the quinone-azine organic electrode material with multiple active sites according to claim 1, characterized in that, The preparation steps of the quinazine-based organic electrode materials I and III are as follows: (1) The naphthoquinone derivative and potassium phthalimide were stirred and refluxed under nitrogen atmosphere for 12 h. After hot filtration and washing, hydrazine hydrate was added for reduction. After washing and vacuum drying, solid o-phenylenediamine derivative was obtained. (2) Weigh o-phenylenediamine and p-hydroxybenzoquinone, then add H2O as solvent, heat the mixture under nitrogen atmosphere, and after the reaction is complete, cool to room temperature, filter to remove solvent, wash with water, and vacuum dry to obtain black powder, i.e. dihydroxyphenazine; (3) Using the dihydroxyphenazine prepared in step (2) and the o-phenylenediamine derivative prepared in step (1) as raw materials, grind them until fully mixed, and heat them to react to obtain a black intermediate product; (4) The intermediate product prepared in step (3) is used to prepare quinone azine organic electrode material with multiple active sites by supercritical fluid method.

5. The application of the quinone-azine organic electrode material with multiple active sites according to claim 1, characterized in that, The preparation steps of the quinazine-based organic electrode material II are as follows: (1) Dissolve o-phenylenediamine in water, add ferric chloride, and heat the solution at 60 °C for 20 min with constant stirring; after standing, filter, wash with pure water until the filtrate is colorless, and then dry the filter cake at 80 °C for 12 h to obtain the orange-red product 2,3-diaminophenazine. (2) Weigh o-phenylenediamine and p-hydroxybenzoquinone, then add H2O as solvent, heat the mixture under nitrogen atmosphere, and after the reaction is complete, cool to room temperature, filter to remove solvent, wash with water, and vacuum dry to obtain black powder, i.e. dihydroxyphenazine; (3) Using the dihydroxyphenazine prepared in step (2) and the 2,3-diaminophenazine prepared in step (1) as raw materials, grind them until fully mixed, and heat them to react to obtain a brown intermediate product; (4) The intermediate product prepared in step (3) is used to prepare quinone azine organic electrode material with multiple active sites by supercritical fluid method.

6. The application of the quinone-azine organic electrode material with multiple active sites according to claim 4 or 5, characterized in that, In step (1), the molar ratio of naphthoquinone derivative and potassium phthalimide is 1:2 to 1:4.5, and the naphthoquinone derivative is selected from 2,3-dichloro-1,4-naphthoquinone or tetrachloronaphthoquinone; the molar ratio of o-phenylenediamine and ferric chloride is 5:

4.

7. The application of the quinone-azine organic electrode material with multiple active sites according to claim 4 or 5, characterized in that, In step (2), the molar ratio of o-phenylenediamine to p-hydroxybenzoquinone is 1:1 to 1:1.5; the reaction conditions are: continuous reflux and stirring at 110 °C for 10 to 12 h.

8. The application of the quinone-azine organic electrode material with multiple active sites according to claim 4 or 5, characterized in that, In step (3), the molar ratio of dihydroxyphenazine to o-phenylenediamine derivative is 1:1 to 1:1.5; the heating reaction temperature is 200 to 400 °C, and the heating reaction time is 4 to 6 h; the molar ratio of 2,3-diaminophenazine to dihydroxyphenazine is 1:

1.

9. The application of the quinone-azine organic electrode material with multiple active sites according to claim 4 or 5, characterized in that, In step (4), the preparation process of the quinone azine organic electrode material with multiple active sites is as follows: the black or brown intermediate product prepared in step (3) is added to anhydrous ethanol, and ultrasonically dispersed to form a uniform dispersion. Then K2Cr2O7 is added, and the mixed solution is sealed in a stainless steel autoclave. The temperature of the autoclave is raised to 30°C, and CO2 is introduced into the autoclave to make the pressure inside the autoclave reach 6 MPa. Then, the autoclave is heated to 130°C with stirring at 300 r / min to make the reaction system reach a supercritical state. After the reaction continues for 3~6 h, the autoclave is cooled to room temperature to release CO2 and the product is taken out. After washing and centrifugation, the product is vacuum dried at 80°C to finally obtain a yellow solid product.

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