Nitrogen-doped high-capacity organic material connected with pyridine ring, preparation method and application of nitrogen-doped high-capacity organic material in organic zinc ion battery
By preparing the bipolar organic molecule 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine as the cathode material for organic zinc-ion batteries, the capacity and cycle life problems of existing materials were solved, and high-capacity and long-life battery performance was achieved.
Patent Information
- Application Number
- CN202511989266.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-04-10
Smart Images
Figure CN121824547A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of zinc-ion battery material synthesis, and specifically discloses a nitrogen-doped high-capacity organic material with a pyridine ring, its preparation method, and its application in organic zinc-ion batteries. Background Technology
[0002] Aqueous zinc-ion batteries are considered a candidate technology for next-generation large-scale energy storage systems due to their high safety, low cost, and good environmental compatibility. These batteries use metallic zinc as the negative electrode and possess a low redox potential (relative to the standard hydrogen electrode -0.76 V), a high theoretical specific capacity (820 mAh g⁻¹), and good aqueous phase stability, thus attracting widespread attention. However, zinc electrodes still face challenges in practical applications, such as dendrite growth, corrosion, hydrogen evolution reaction, and electrode passivation. Furthermore, the insufficient overall energy density of the battery and the poor structural stability of the positive electrode material also limit its further development. Currently, research focuses on the design of the positive electrode material, optimization of the electrolyte composition, functionalization of the separator, and protection strategies for the zinc negative electrode interface.
[0003] As a key determinant of battery performance, the structural design of cathode materials is crucial for improving the overall electrochemical performance of aqueous zinc-ion batteries. Currently, widely studied inorganic cathode materials, such as manganese-based, vanadium-based, and molybdenum-based oxides / sulfides, as well as Prussian blue analogs, are limited by issues such as limited elemental resources, environmental toxicity, and large volume changes in crystal structure during charge and discharge, making them unsuitable for future large-scale energy storage needs. In contrast, organic cathode materials composed of lightweight elements such as carbon, hydrogen, oxygen, nitrogen, and sulfur offer advantages such as renewable resources, environmental friendliness, and strong structural designability, and are considered ideal cathode candidate systems for aqueous zinc-organic batteries.
[0004] Since polyaniline was first reported as an organic electrode material in 1985, related research has continued to develop over the past four decades. A variety of novel organic compounds with diverse structures have been developed and applied to the cathodes of zinc-organic batteries. These mainly include carbonyl compounds, imine compounds, imine-carbonyl hybrid systems, nitroaromatic compounds, nitroxide radical compounds, organosulfur compounds, triphenylamines, triphenylphosphines, and conductive small molecules. Through rational structural control and material modification strategies, zinc-organic batteries have continuously improved in terms of specific capacity, operating voltage, rate performance, and cycle stability.
[0005] Among various organic cathodes, imine compounds, as typical n-type electrode materials, exhibit superior redox activity and cycle stability in aqueous electrolytes compared to traditional carbonyl compounds due to their extended π-conjugated structure. For example, Chen et al. first used phenazine in zinc organic battery cathodes, achieving a 232 mAh g⁻¹. -1It exhibits high specific capacity and good cycle performance, but its average discharge voltage is relatively low (approximately 0.8 V). To further improve capacity, researchers developed hexaazanaphthalene with a larger conjugated plane as a cathode material. Its molecule contains six -C=N- reaction sites. Kundu et al. developed a small molecule of 1,4-bis(diphenylamine)benzene containing two tertiary nitrogen atoms, achieving an average output voltage of 1.25 V and a capacity of approximately 125 mAh g⁻¹ in aqueous zinc-ion batteries. -1 These two tertiary nitrogen atoms undergo a two-step reversible oxidation / reduction, accompanied by anion insertion / release into a highly concentrated aqueous solution with high oxidation stability. Paired with a cellulose nanocrystalline film to inhibit the diffusion of active material into the electrolyte, the BDB cathode provides 112 mAh g / L. -1 The capacity and at 0.39A g -1 82% retention rate after 500 cycles.
[0006] Despite some progress in the aforementioned materials, there is still room for further improvement in the theoretical specific capacity of existing organic cathodes. Summary of the Invention
[0007] The purpose of this invention is to provide a high-performance cathode material for organic zinc-ion batteries. It involves designing organic molecules with extended π-conjugation to enhance intermolecular interactions and suppress dissolution of the organic cathode material. Simultaneously, it increases the active sites, theoretical specific capacity, and redox potential by connecting nitrogen-hydrogen bonds and carbon-nitrogen double bonds. When applied to the cathode material of organic zinc-ion batteries, it exhibits advantages such as high electrochemical capacity and long cycle life, demonstrating broad application prospects.
[0008] This invention develops a bipolar organic electrode material containing multiple redox potential active sites, enabling multi-electron storage and thus exhibiting a high theoretical specific capacity. The structural formula of this material is as follows: .
[0009] The preparation process of the nitrogen-doped high-capacity organic material with a pyridine ring according to the present invention is as follows:
[0010] The specific preparation method steps are as follows: Step 1: Weigh o-phenylenediamine and add it to the solvent, heat and stir in an oil bath until fully dissolved; then weigh anhydrous ferric chloride and add it to the solvent, sonicate to dissolve; then add the ferric chloride solution to the o-phenylenediamine solution, heat in an oil bath for 10 min, and stir at room temperature for 4 h; then let stand, filter, collect the reddish-brown solid, wash it three times with ultrapure water, and dry it under vacuum to obtain the reddish-brown solid.
[0011] The molar ratio of o-phenylenediamine to anhydrous ferric chloride is 1:1 to 1:2; the solvent is water; and the oil bath is heated to 50-60℃.
[0012] Step 2: Add the above reddish-brown solid and 4-pyridinecarboxaldehyde to an organic solvent, heat the reaction in an oil bath under nitrogen protection, cool the reactants to room temperature, then heat in an ice bath for 4 hours, filter to remove the solvent, collect the brown solid, wash it three times with ultrapure water, then wash it three times with anhydrous ethanol, and then dry it under vacuum to obtain the brown solid.
[0013] The molar ratio of the reddish-brown solid 2,3-diaminophenazine and 4-pyridinecarboxaldehyde is 1:1 to 1:2.5; the solvent is selected from DMF; the oil bath heating reaction temperature is 120-140℃, and the reaction time is 36-48 h.
[0014] The prepared 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine was used as the positive electrode material of an organic zinc-ion battery and assembled with a zinc metal sheet to form an organic zinc-ion battery.
[0015] The positive electrode material is obtained by uniformly dispersing organic positive electrode material, Ketjen black and PVDF in isopropanol, coating it on carbon paper, and then vacuum drying.
[0016] The beneficial effects of this invention are: This invention enhances the availability and electronic conductivity of active sites by constructing a synergistic connection between nitrogen-hydrogen bonds and carbon-nitrogen double bonds, thereby improving the theoretical specific capacity of the material. A nitrogen-doped high-capacity organic material, 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine, with a pyridine ring is prepared and used as the positive electrode material for organic zinc-ion batteries, achieving the goal of improving the electrochemical capacity and cycle life of organic zinc-ion batteries.
[0017] This invention not only provides an organic zinc-ion battery using 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine as the positive electrode material, but also solves the problems of low actual electrochemical capacity and short cycle life caused by dissolution in electrolyte that are common in existing organic zinc-ion batteries. Attached Figure Description
[0018] Figure 1 The image shows the 1H NMR spectrum of 2,3-diaminophenazine corresponding to Example 1.
[0019] Figure 2 The image shows the 1H NMR spectrum of the organic cathode material corresponding to Example 1.
[0020] Figure 3 The image shows the infrared spectrum of the organic cathode material corresponding to Example 1.
[0021] Figure 4 The charge-discharge curves are for the zinc-ion battery prepared with the organic cathode material corresponding to Example 1.
[0022] Figure 5 The graph shows the rate performance of the zinc-ion battery prepared with the organic cathode material corresponding to Example 1 at different current densities.
[0023] Figure 6 The cycle stability of the zinc-ion battery prepared using the organic cathode material corresponding to Example 1.
[0024] Figure 7 The charge-discharge curves are for the zinc-ion battery prepared with the organic cathode material corresponding to Example 4.
[0025] Figure 8 The cycle stability of the zinc-ion battery prepared using the organic cathode material corresponding to Example 4. Detailed Implementation
[0026] 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. Furthermore, the technical features described in the various embodiments of the invention below can be combined with each other as long as they do not conflict with each other.
[0027] Example 1: Preparation of 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine
[0028] (1) Weigh 10.814 g (0.1 mol) of o-phenylenediamine and add it to 800 ml of water. Heat and stir in an oil bath at 50 °C until fully dissolved. Then weigh 12.976 g (0.08 mol) of anhydrous ferric chloride and add it to 500 ml of water. Dissolve by sonication. Add the ferric chloride solution to the o-phenylenediamine solution, add water to 2000 ml, heat and stir in an oil bath at 50 °C for 10 min, and then stir at room temperature for 4 h. Then let it stand, pour off the supernatant, add water to 2000 ml, let it stand again, pour off the supernatant, and repeat three times. Filter, collect the reddish-brown solid, wash it three times with ultrapure water, and dry it under vacuum to obtain 2,3-diaminophenazine. The yield was 88%.
[0029] Figure 1 The image shows the 1H NMR spectrum of 2,3-diaminophenazine corresponding to Example 1. The peak positions in the image are consistent with the structure, confirming the synthesis of 2,3-diaminophenazine.
[0030] (2) Weigh 0.21 g (1 mmol) of 2,3-diaminophenazine and 0.25 ml (2.5 mmol) of 4-pyridinecarboxaldehyde, add them to 5 ml of DMF, and heat under nitrogen protection at 140 °C in an oil bath under reflux for 48 h. After the reactants are cooled to room temperature, they are placed in an ice bath for 4 h, filtered to remove the solvent, and the brown solid is collected. It is washed three times with ultrapure water and then three times with anhydrous ethanol. After vacuum drying, 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine is obtained. The yield is 90%.
[0031] Figure 2 The 1H NMR spectrum of this bipolar organic electrode material shows corresponding 1H NMR peaks at 5.7, 7.8, 8.2, 8.5, and 9.1. Figure 3 The image shows the infrared spectrum of the organic cathode material corresponding to Example 1. The disappearance of the carbon C=O group and the appearance of the NH bond prove the formation of 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine.
[0032] The bipolar organic electrode material provided in this embodiment is used as a positive electrode material for zinc-ion batteries. Specific examples are given below: Preparation of organic cathode for zinc-ion batteries: Organic cathode material, Ketjen black, and PVDF were uniformly dispersed in 5 mL of isopropanol at a mass ratio of 4.5:4.5:1, and then uniformly coated onto carbon paper. The mixture was then vacuum-dried at 60°C for 12 h to obtain the organic cathode. A zinc-ion battery was assembled using the organic cathode, a zinc sheet as the negative electrode, a glass fiber membrane as the separator, and a ZnSO4 solution as the electrolyte.
[0033] Perform charge and discharge tests on the battery. Figure 4 The zinc-ion battery prepared using the materials in Example 1 operates at a current density of 0.05 A g. -1 The charge-discharge curves below show that this organic electrode material has a high specific capacity, with a discharge capacity of up to 235 mAh g⁻¹. -1 .
[0034] Figure 5 The graph shows the rate performance of the zinc-ion battery prepared with the organic cathode material corresponding to Example 1 at different current densities. As can be seen from the graph, when the current density increases from 0.05 A g... -1 Increased to 5.0 Ag -1 That is, with a 100-fold increase in current density, the electrochemical discharge specific capacity is retained at 79%, and it recovers to a current density of 0.05 A g. -1 The capacity can be restored to 91% of the initial capacity, indicating that the battery has excellent capacity retention and is suitable for charging and discharging at high current densities.
[0035] Figure 6The cycle stability of the zinc-ion battery prepared using the organic cathode material corresponding to Example 1 is evaluated. The battery operates at 0.1 A g... -1 After undergoing 5000 charge-discharge cycles, the capacity can still be maintained at 90.8%, indicating that the zinc-ion battery composed of this material has good cycle stability.
[0036] Example 2
[0037] The preparation process of 2,3-diaminophenazine is the same as in Example 1.
[0038] Weigh 0.21 g (1 mmol) of 2,3-diaminophenazine and 0.1 ml (1.2 mmol) of 4-pyridinecarboxaldehyde, add them to 10 ml of DMF, and heat in an oil bath at 120 °C for 36 h under nitrogen protection. After cooling the reaction mixture to room temperature, heat in an ice bath for 4 h, filter to remove the solvent, collect the brown solid, wash three times with ultrapure water, then wash three times with anhydrous ethanol, and dry under vacuum to obtain 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine. Add 10 ml of 30% HNO3, heat in an oil bath at 140 °C, and reflux for 3 h. The yield is 70%.
[0039] A zinc-ion battery was assembled using this organic electrode material, following the same procedure as in Example 1. Its discharge capacity reached 255 mAh g⁻¹. -1 The battery operates at 0.1 A g. -1 After undergoing 5000 charge-discharge cycles, the capacity can still be maintained at 89.2%, indicating that the zinc-ion battery composed of this material has good cycle stability.
[0040] Example 3
[0041] The preparation process of 2,3-diaminophenazine is the same as in Example 1.
[0042] Weigh 0.21 g (1 mmol) of 2,3-diaminophenazine and 0.094 ml (1 mmol) of 4-pyridinecarboxaldehyde, add them to 5 ml of DMF, and heat in an oil bath at 130 °C under nitrogen protection for 40 h under reflux. After the reaction mixture cools to room temperature, filter to remove the solvent, collect the brown solid, wash three times with ultrapure water, then wash three times with anhydrous ethanol, and dry under vacuum to obtain 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine. The yield is 75%.
[0043] A zinc-ion battery was assembled using this organic electrode material, following the same procedure as in Example 1. Its discharge capacity reached 249 mAh g⁻¹. -1 The battery operates at 0.1 A g. -1 After undergoing 5000 charge-discharge cycles, the capacity can still be maintained at 90.2%.
[0044] Example 4: Preparation and Battery Performance Study of 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine
[0045] (1) Weigh 10.814 g (0.1 mol) of o-phenylenediamine and add it to 800 ml of water. Heat and stir in an oil bath at 50 °C until fully dissolved. Then weigh 32.44 g (0.2 mol) of anhydrous ferric chloride and add it to 500 ml of water. Dissolve by sonication. Add the ferric chloride solution to the o-phenylenediamine solution, add water to 2000 ml, heat and stir in an oil bath at 50 °C for 10 min, and then stir at room temperature for 4 h. Then let it stand, pour off the supernatant, add water to 2000 ml, let it stand again, pour off the supernatant, and repeat three times. Filter, collect the reddish-brown solid, wash it three times with ultrapure water, and dry it under vacuum to obtain 2,3-diaminophenazine. The yield was 91%.
[0046] (2) Weigh 0.21 g (1 mmol) of 2,3-diaminophenazine and 0.25 ml (2.5 mmol) of 4-pyridinecarboxaldehyde, add them to 5 ml of DMF, heat in an oil bath at 140 °C under nitrogen protection, and reflux for 48 h. After the reactants are cooled to room temperature, they are placed in an ice bath for 4 h, filtered to remove the solvent, and the brown solid is collected. It is washed three times with ultrapure water, then three times with anhydrous ethanol, and dried under vacuum to obtain 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine. The yield is 92%.
[0047] A zinc-ion battery was assembled using this organic electrode material, following the same procedure as in Example 1. Its discharge capacity reached 258 mAh g⁻¹. -1 The battery operates at 0.1 A g. -1 After undergoing 5000 charge-discharge cycles, the battery still retains 94.6% of its capacity. This battery operates at 5 A g... -1 After undergoing 5000 charge-discharge cycles, the capacity can still be maintained at 98.7%.
[0048] Example 5
[0049] The preparation process of 2-(pyridin-4-yl)-1H-imidazo[4,5-b]phenazine is the same as in Example 1.
[0050] The zinc-ion battery was made using the bipolar organic electrode material prepared in Example 1. The zinc-ion battery was assembled with the following steps: the mass ratio of organic positive electrode material, Ketjen black and PVDF was changed to 3:6:1 during the electrode preparation process, and the other steps were the same as the zinc-ion battery preparation method in Example 1.
[0051] Figure 7 The image shows the charge-discharge curves of the zinc-ion battery prepared using the organic cathode material corresponding to Example 4. Its discharge capacity was tested at a current density of 0.1 A g. -1The capacity can reach 193 mAh g -1 .
[0052] Figure 8 The cycle stability of the zinc-ion battery prepared with the organic cathode material corresponding to Example 4 is shown. After 3000 charge-discharge cycles, the capacity retention rate is 95.2%.
[0053] Compare with Example 1
[0054] Weigh 10.814 g (0.1 mol) of p-phenylenediamine and add it to 800 ml of water. Heat and stir in an oil bath at 50°C until fully dissolved. Then weigh 12.976 g (0.08 mol) of anhydrous ferric chloride and add it to 500 ml of water. Dissolve by sonication. Add the ferric chloride solution to the p-phenylenediamine solution, add water to 2000 ml, heat and stir in an oil bath at 50°C for 10 min, and then stir at room temperature for 4 h. Let it stand, pour off the supernatant, add water to 2000 ml, let it stand again, pour off the supernatant, and repeat three times. Filter by suction, and no precipitate appears.
[0055] Compare with Example 2
[0056] Weigh 10.814 g (0.1 mol) of m-phenylenediamine and add it to 800 ml of water. Heat and stir in an oil bath at 50°C until fully dissolved. Then weigh 12.976 g (0.08 mol) of anhydrous ferric chloride and add it to 500 ml of water. Dissolve the solution by sonication. Add the ferric chloride solution to the m-phenylenediamine solution, add water to 2000 ml, heat and stir in an oil bath at 50°C for 10 min, and then stir at room temperature for 4 h. Let it stand, pour off the supernatant, add water to 2000 ml, let it stand again, pour off the supernatant, and repeat three times. Filter by suction, and no precipitate appears.
[0057] When p-phenylenediamine or m-phenylenediamine was used instead of o-phenylenediamine, no precipitation occurred.
[0058] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A nitrogen-doped high-capacity organic material with a pyridine ring, characterized in that, The structural formula of the nitrogen-doped high-capacity organic material with a pyridine ring is shown below: 。 2. A method for preparing a nitrogen-doped high-capacity organic material with a pyridine ring according to claim 1, characterized in that, The preparation method steps are as follows: Step 1: Add o-phenylenediamine to the solvent and heat in an oil bath with stirring until fully dissolved; then add anhydrous ferric chloride to the solvent and sonicate to dissolve; then add the ferric chloride solution to the o-phenylenediamine solution and heat in an oil bath to react, then stir at room temperature for 4 hours, let stand, filter, collect the reddish-brown solid, wash three times with ultrapure water, and dry under vacuum to obtain the reddish-brown solid (2,3-diaminophenazine). Step 2: React 2,3-diaminophenazine with 4-pyridinecarboxaldehyde to obtain a nitrogen-doped high-capacity organic material with a pyridine ring.
3. The method for preparing nitrogen-doped high-capacity organic materials with pyridine rings according to claim 2, characterized in that, In step 1, the molar ratio of o-phenylenediamine to anhydrous ferric chloride is 1:1 to 1:
2.
4. The method for preparing nitrogen-doped high-capacity organic materials with pyridine rings according to claim 2, characterized in that, In step 1, the organic solvent is water; the oil bath heating temperature is 50-60℃, and the reaction time is 10 min.
5. The method for preparing a nitrogen-doped high-capacity organic material with a pyridine ring according to claim 2, characterized in that, In step 2, the molar ratio of 2,3-diaminophenazine to 4-pyridinecarboxaldehyde is 1:1 to 1:2.
5.
6. The method for preparing a nitrogen-doped high-capacity organic material with a pyridine ring according to claim 2, characterized in that, In step 2, the reaction temperature is 120-140℃ and the reaction time is 36-48 h.
7. An application of the nitrogen-doped high-capacity organic material with a pyridine ring according to claim 1, characterized in that, The nitrogen-doped high-capacity organic material with a pyridine ring is used to prepare the cathode material for organic zinc-ion batteries.
8. The application of the nitrogen-doped high-capacity organic material with a pyridine ring according to claim 7, characterized in that, The cathode material is obtained by uniformly dispersing organic cathode material, Ketjen black and PVDF in isopropanol, coating it on carbon paper, and then vacuum drying.