A donor-acceptor porous aromatic framework material and ultra-low temperature organic battery
By preparing donor-acceptor based porous aromatic framework material DA PAF as the positive electrode material of potassium ion battery, the problems of low capacity and poor cycle stability were solved, high specific capacity and good electrochemical performance were achieved, and it is suitable for ultra-low temperature environment.
Patent Information
- Application Number
- CN202411652138.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2044-11-19
AI Technical Summary
Existing potassium-ion battery electrode materials generally suffer from problems such as low capacity, poor cycle stability, and unstable rate performance.
A donor-acceptor based porous aromatic framework material (DA PAF) was used as the cathode material for a potassium-ion battery. Multiple redox active sites were synthesized through Schiff base reaction, sodium dithionite reduction reaction and palladium acetate catalysis to prepare an ultra-low temperature organic battery.
DA PAF material exhibits high specific capacity and good stability, can maintain a high reversible specific capacity at low temperatures, is easy to synthesize and has low cost, and is suitable for mass production.
Smart Images
Figure CN119505233B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of energy storage technology and relates to a porous aromatic framework containing multiple redox active sites for use as a cathode material in potassium-ion batteries. The donor-acceptor structure can promote charge transfer, thereby accelerating reaction kinetics and improving the specific capacity of potassium-ion batteries. Background Technology
[0002] High-energy-density lithium-ion batteries are currently the leading electrochemical energy storage technology, but the uneven distribution and rapid depletion of lithium resources have raised concerns about their sustainability and cost. Furthermore, with the increasing demand for various applications such as portable electronics, electric vehicles, and large-scale energy storage devices, rechargeable battery technology with renewable resources and high energy density has become an urgent need.
[0003] In this respect, due to the high natural abundance of potassium (1.5%, lithium 0.0017%) and low K+, + Potassium-ion batteries, with their potential of approximately 1000 K / 2000 kJ / k, have attracted increasing research interest. Furthermore, due to their smaller Stokes radius and lower solvation energy, potassium-ion batteries are better adapted to varying operating temperatures and can achieve rapid kinetics at low temperatures. However, K / 2000 kJ / k is a significant factor. + With a larger diameter Lithium ions are ) and relatively heavy mass. This large-sized K + Repeated insertion / extraction of inorganic electrode materials leads to significant volume changes and slow electrode kinetics. In contrast, organic electrode materials have been widely used in various rechargeable metal-ion batteries (lithium, zinc, aluminum-ion batteries, etc.) in recent years due to their flexible structural designability, high level of functionality, and environmental friendliness. Built-in groups in organic molecules such as C=N, C=O, and N=N can serve as reactive sites for metal ion storage. Considering the problem of easy solubility of small organic molecule electrodes in organic electrolytes, immobilizing redox active groups in porous two-dimensional or three-dimensional (2D or 3D) frameworks has been extensively explored and proven to be an effective strategy for obtaining more reliable electrodes.
[0004] Porous aromatic frameworks (PAFs), as an emerging porous material, exhibit a wealth of excellent properties, such as lightweight, customizable pore structures, and tunable framework structures. Composed of abundant aromatic units, their modular structure and high structural stability make them potential applications in storage, sensing, and catalysis. When used as electrode materials, PAFs designed using a donor-acceptor approach can promote charge transfer, accelerate reaction kinetics, and thus improve capacity performance. Donor structural units mainly include phenothiazines, phenazines, triphenylamines, thiophenes, pyrene, and tetrathiofulvalenes. Acceptor structural units mainly include triazines, hexaazanaphthalenes, pyrene-tetrones, anthraquinones, acid anhydrides, phthalocyanines, porphyrins, and benzothiazoles. Summary of the Invention
[0005] To address the problems of low capacity, poor cycle stability, and unstable rate performance commonly found in most potassium-ion battery electrode materials, this invention provides a porous aromatic framework material that can be used as a positive electrode material for potassium-ion batteries, and its preparation method.
[0006] The above-mentioned technical problems are solved by the following technical solutions:
[0007] A donor-acceptor based porous aromatic framework material, denoted as DA PAF, has the following structure:
[0008]
[0009] A method for preparing a donor-acceptor based porous aromatic framework material includes the following steps:
[0010] 1) Using compounds 1 and 2 as raw materials, compound 3 was synthesized by refluxing in acetic acid solution for 40 hours via a Schiff base reaction. Compound 1 is cyclohexanehexanone, and compound 2 is 4-bromo-1,2-phenylenediamine. The structural formula of compound 3 is as follows:
[0011]
[0012] 2) Using compound 4 as a starting material, compound 5 was synthesized by refluxing in a mixed solution of ethanol and water for 3 hours via a sodium dithionite reduction reaction. Compound 4 is a phenazine. The structural formula of compound 5 is as follows:
[0013]
[0014] 3) Compound 3, compound 5, potassium carbonate, and palladium acetate were refluxed in an organic solvent for 48 hours, and the reaction was carried out in an inert gas atmosphere to obtain compound 6, which is the donor-acceptor based porous aromatic framework material; the organic solvent is toluene.
[0015] Preferably, in step 1), the molar ratio of compound 1 to compound 2 is 1:4, and the entire reaction is carried out in an inert gas atmosphere.
[0016] Preferably, in step 2), the reaction is carried out in an inert gas atmosphere, and the entire reaction process avoids contact with air to prevent the product from being oxidized.
[0017] Preferably, in step 3), the molar ratio of compound 3 to compound 5 is 2:3.
[0018] An ultra-low temperature organic battery, which is a potassium-ion battery using the aforementioned donor-acceptor based porous aromatic framework material (DA PAF) as the positive electrode material, is prepared according to the following steps:
[0019] 1) Add DA PAF, acetylene black, and PVDF to the solvent NMP (N-methylpyrrolidone) in a mass ratio of 6:3:1 and grind them into a uniform slurry. Then, use a coating machine to coat it onto aluminum foil.
[0020] 2) Place the coated aluminum foil in an oven at 80℃ and dry for 12 hours to remove residual solvent;
[0021] 3) Cut the dried electrode sheet from step 2) into circular electrode sheets with a diameter of 12mm for later use;
[0022] 4) Battery assembly: Using 2025 type button cells, circular electrode plates, separators, electrolytes, potassium plates, gaskets, springs, and positive electrode shells are placed in sequence in the negative electrode shell. Then, they are sealed with a packaging machine to obtain potassium-ion 2025 type button cells. After that, constant current charge and discharge tests are performed using the Blue Electric / Newway battery testing system.
[0023] Preferably, in step 4), the electrolyte is a 1 mol / L KPF6 ethylene glycol dimethyl ether solution with a volume of 100 μL, and the diaphragm is a glass fiber membrane.
[0024] Beneficial effects:
[0025] 1. The DA PAF synthesized in this invention has multiple redox centers, exhibiting high specific capacity and good stability as a cathode material for potassium-ion batteries, with a capacity of 200 mAg. -1 At a current density, it exhibits 210 mAh g. -1 The specific capacity is around 30Ag. -1 At a current density, it can cycle for 11,000 cycles without significant degradation.
[0026] 2. DA PAF, as a cathode material for potassium-ion batteries, exhibits good reversible specific capacity at low temperatures. At -20℃, it has a capacity of 200 mAg. -1It can exhibit 170 mAh g at a current density. -1 Approximately 200 mAg capacity at -40℃. -1 It can exhibit 140 mAh g at a current density. -1 The specific capacity is approximately [value missing]. At -80℃, 50 mAg [capacity missing]. -1 It can exhibit 75 mAh g at a current density. -1 The specific capacity of the left and right sides.
[0027] 3. The DA PAF material synthesized in this invention is easy to synthesize, has low cost, outstanding electrochemical performance, and is easy to mass-produce. Attached Figure Description
[0028] Figure 1 FTIR image of the donor-acceptor porous aromatic framework DA PAF;
[0029] Figure 2 NMR image of the donor-acceptor porous aromatic framework DA PAF;
[0030] Figure 3 XRD pattern of donor-acceptor porous aromatic framework DA PAF;
[0031] Figure 4 SEM image of the donor-acceptor porous aromatic framework DA PAF;
[0032] Figure 5 Porous aromatic framework DA PAF as donor and acceptor is used as a positive electrode material in potassium-ion batteries in 200 mAh g -1 Charge-discharge curves at current density;
[0033] Figure 6 Rate capability diagram of DA PAF, a porous aromatic framework for donor and acceptor, as a positive electrode material for potassium-ion batteries;
[0034] Figure 7 Porous aromatic framework DA PAF as donor and acceptor is used as a positive electrode material in potassium-ion batteries at 30 A g. -1 Cyclic plot at current density;
[0035] Figure 8 Cyclic voltammetry curves of porous aromatic framework DA PAF as donor and acceptor cathode material in potassium-ion battery.
[0036] Figure 9 Impedance diagram of DA PAF, a porous aromatic framework for donor and acceptor, as a cathode material for potassium-ion batteries.
[0037] Figure 10Porous aromatic framework DA PAF as donor and acceptor exhibits 200 mAg as a cathode material in potassium-ion batteries at -20℃ and -40℃. -1 Cyclic plot at current density.
[0038] Figure 11 Porous aromatic framework DA PAF as donor and acceptor, as a positive electrode material for potassium-ion batteries, achieves 50 mAg at -80℃. -1 Cyclic plot at current density. Detailed Implementation
[0039] This invention provides a donor-acceptor based porous aromatic framework material (DA PAF) with multiple redox active sites, which can be used as an electrode material for organic potassium-ion batteries. The synthetic route of the DA PAF is as follows:
[0040] Compound 3 was synthesized by refluxing cyclohexanehexanone (referred to as compound 1) and 4-bromo-1,2-phenylenediamine (referred to as compound 2) in acetic acid.
[0041]
[0042] Compound 4 was refluxed with sodium dithionite in a mixed solution of ethanol and water to give compound 5.
[0043]
[0044] Compound 3 was refluxed with compound 5, potassium carbonate, and palladium acetate in an organic solvent to give compound 6 (DA PAF), wherein the organic solvent was a toluene solution (1 mol / L) of toluene and tritert-butylphosphine.
[0045]
[0046] Example 1
[0047] 1) Cyclohexanehexanone (312 mg, 1 mmol) and 4-bromo-1,2-phenylenediamine (748 mg, 4 mmol) were added to anhydrous acetic acid (60 mL) under a nitrogen atmosphere, and then refluxed for 40 h. After cooling to room temperature, the mixture was poured into water, filtered, and thoroughly washed with deionized water and ethanol to remove excess acid, yielding a light green solid (denoted as compound 3). Finally, the product was dried under vacuum at 80 °C.
[0048] 2) Compound 4 (6 g, 33.3 mmol) was dispersed in 150 mL of ethanol and heated to reflux under a nitrogen atmosphere. Then, sodium dithionite (58 g, 333 mmol) dissolved in 600 mL of water was added in one go, and the mixture was heated to reflux for 3 h. After cooling to room temperature, the solid was filtered and thoroughly washed with deionized water. The pale blue solid (designated as compound 5) was collected. Finally, the product was dried under vacuum at 80 °C.
[0049] 3) A mixture of compound 3 (364 mg, 0.6 mmol), compound 5 (164 mg, 0.9 mmol), and potassium carbonate (1.3 g, 9.406 mmol) was added to a two-necked flask, and toluene (50 mL) was added under a nitrogen atmosphere. The mixture was heated to 80 °C, and palladium acetate (26.3 mg, 0.117 mmol) and a toluene solution of tritert-butylphosphine (1 mL) were added. The reaction mixture was stirred at 120 °C for 48 h under a nitrogen atmosphere.
[0050] 4) After cooling the obtained mixture to room temperature, the solid was filtered and then washed with hot water and methanol. Finally, it was washed with water, methanol, dichloromethane, and acetone respectively by Soxhlet extraction, and dried under vacuum at 80°C overnight to obtain a dark red powdery solid, which is the donor-acceptor based porous aromatic framework material DA PAF. The obtained material was characterized by FTIR, NMR, XRD, and SEM, and the results are as follows. Figures 1-4 As shown, this proves that DA PAF was successfully synthesized.
[0051] Example 2
[0052] Potassium-ion batteries were prepared using the DA PAF synthesized in Example 1 as the positive electrode material: HATNPZ, acetylene black, and PVDF were added to NMP at a mass ratio of 6:3:1 and ground into a uniform slurry. The slurry was then coated onto aluminum foil using a coating machine and placed in an oven at 80°C for 14 hours to remove residual solvent. The slurry was then cut into circular electrode sheets with a diameter of 12 mm for later use. Using the 2025 coin cell standard, the circular electrode sheet, separator, electrolyte, potassium sheet, gasket, spring sheet, and positive electrode shell were sequentially placed in the negative electrode shell. After encapsulation, a potassium-ion 2025 coin cell was obtained. The constant current charge-discharge test was then performed using the Blue Electric / Newway battery testing system.
[0053] Depend on Figure 5 As can be seen from the charge-discharge curves, the battery prepared in this invention can achieve a charge-discharge ratio of 200 mAg. -1 It exhibits 210 mAh g at a current density. -1 Specific capacity, at the same time, Figure 6 The rate performance of the DA PAF electrode at different current densities is presented, with the current density reaching 5 Ag. -1At that time, the capacity can still reach 190mAh g -1 When the current returns to 200mAg -1 At this time, the capacity can return to its initial capacity. At 30Ag -1 The stability of the battery was tested at a current density, and the results are as follows: Figure 7 As shown, the cycling capacity shows almost no decay after 11,000 cycles. According to... Figure 8 The CV curves shown indicate five distinct redox peaks representing a multi-step redox process, and exhibit a significant PF6 peak at high potentials. - Storage process. To study the battery's kinetic behavior, impedance tests were performed on the battery, and the results are as follows: Figure 9 As shown, the impedance value remained low after 200 cycles, indicating that DA PAF possesses good electrochemical kinetics, potentially leading to its excellent electrochemical performance. Further testing was conducted on the electrochemical performance of DA PAF at low temperatures. Figure 10 The cycling curves show that DA PAF reaches 200 mAg at -20℃ and -40℃. -1 It exhibited 170 mAh g at current density. -1 and 140mAh g -1 The specific capacity was measured. Further testing of the battery's performance at an extreme temperature of -80°C yielded the following results: Figure 11 As shown, at 50mAg -1 It exhibits 75 mAh g at current density -1 Specific capacity.
Claims
1. A donor-acceptor based porous aromatic framework material, denoted as DA PAF, has the following structure:
2. A method for preparing the donor-acceptor based porous aromatic framework material according to claim 1, comprising the following steps: 1) Using compounds 1 and 2 as raw materials, compound 3 was synthesized by refluxing in acetic acid solution for 40 hours via a Schiff base reaction. Compound 1 is cyclohexanehexanone, and compound 2 is 4-bromo-1,2-phenylenediamine. The structural formula of compound 3 is as follows: 2) Using compound 4 as a starting material, compound 5 was synthesized by refluxing in a mixed solution of ethanol and water for 3 hours via a sodium dithionite reduction reaction. Compound 4 is a phenazine. The structural formula of compound 5 is as follows: 3) Compound 3, compound 5, potassium carbonate, and palladium acetate were refluxed in an organic solvent for 48 hours, and the reaction was carried out in an inert gas atmosphere to obtain compound 6, which is the donor-acceptor based porous aromatic framework material; the organic solvent is toluene.
3. The method for preparing a donor-acceptor based porous aromatic framework material according to claim 2, characterized in that, In step 1), the molar ratio of compound 1 to compound 2 is 1:4, and the entire reaction is carried out in an inert gas atmosphere.
4. The method for preparing a donor-acceptor based porous aromatic framework material according to claim 2, characterized in that, In step 2), the reaction must be carried out in an inert gas atmosphere, and the entire reaction process must avoid contact with air to prevent the product from being oxidized.
5. The method for preparing a donor-acceptor based porous aromatic framework material according to claim 2, characterized in that, In step 3), the molar ratio of compound 3 to compound 5 is 2:
3.
6. An ultra-low temperature organic battery, which is a potassium-ion battery using the donor-acceptor based porous aromatic framework material as described in claim 1 as the positive electrode material, is prepared according to the following steps: 1) Add DA PAF, acetylene black, and PVDF to the solvent N-methylpyrrolidone in a mass ratio of 6:3:1 and grind them into a uniform slurry. Then, use a coating machine to coat it onto aluminum foil. 2) Place the coated aluminum foil in an oven at 80℃ and dry for 12 hours to remove residual solvent; 3) Cut the dried electrode sheet from step 2) into circular electrode sheets with a diameter of 12mm for later use; 4) Battery assembly: Using a 2025 type coin cell, a circular electrode plate, separator, electrolyte, potassium plate, gasket, spring, and positive electrode shell are placed in sequence in the negative electrode shell, and then sealed with a sealing machine to obtain a potassium-ion 2025 type coin cell.
7. The ultra-low temperature organic battery according to claim 6, characterized in that, In step 4), the electrolyte is a 1 mol / L KPF6 ethylene glycol dimethyl ether solution with a volume of 100 μL, and the diaphragm is a glass fiber membrane.