Chemical self-charging aqueous zinc-potassium organic battery anode material, preparation method and application

Abstract

The chemical self-charging aqueous zinc-potassium organic battery positive electrode material, preparation method and application belong to the technical field of energy storage, and the chemical self-charging aqueous zinc-potassium organic battery positive electrode material is a porous aromatic framework material, denoted as PAF-305, and the preparation method is as follows: Schiff base reaction is carried out by taking cyclohexanehexone octahydrate and 1,2,4,5-benzene tetraamine tetrahydrochloride as raw materials, the obtained product is subjected to reflux reaction with 4,5,9,10-pyrene tetraone in an organic solvent, and the product is washed and dried to obtain the porous aromatic framework material PAF-305; the obtained product can be used as a positive electrode material to prepare an aqueous zinc-potassium mixed ion battery. The PAF-305 prepared by the application exhibits high specific capacity and good stability as the positive electrode material of the aqueous zinc-potassium mixed ion battery, and can realize the air self-charging characteristics in a harsh environment.

Description

Technical Field

[0001] This invention belongs to the field of energy storage technology and relates to a porous aromatic framework material rich in C=N bond active sites for the positive electrode material of an air-self-charging zinc-potassium hybrid ion battery. This enables the battery to achieve normal charging characteristics without external power supply. Background Technology

[0002] The increasing energy consumption and environmental problems are driving the development of new energy storage technologies. Among many new energy storage technologies, rechargeable batteries are the most promising and efficient energy storage technology for large-scale industrialization. Aqueous zinc-ion batteries (AZIBs) have attracted much attention due to their high capacity, low cost, and environmentally friendly characteristics. Typically, depleted AZIBs can only be recharged through the grid; however, in some rugged environments or remote mountainous areas, battery reuse is limited. To overcome this limitation, rechargeable battery systems can be combined with external energy harvesting systems (solar, wind, geothermal, air, etc.) to construct self-charging systems, enabling the collection and utilization of clean energy. However, in some cases, these external energy harvesting devices are not always available and cannot provide a reliable energy supply to the battery system. Furthermore, the construction of external energy harvesting systems increases the complexity and cost of the overall system, hindering large-scale industrialization. Therefore, the realization of power-based self-charging integrated energy storage systems will inevitably attract widespread development and research.

[0003] Oxygen is abundant and readily available in the air, and can provide energy through redox reactions. Therefore, combining the chemical energy of oxygen with the chemical energy of rechargeable battery electrode materials can realize low-cost, high-efficiency self-charging battery systems. Compared to metal-air batteries, air-based self-charging zinc-ion batteries convert the chemical energy of oxygen into electrical energy during charging, which is then stored in the system. The air self-charging process is achieved through the redox reaction between the battery's positive electrode and oxygen; therefore, functionalizing the electrode materials to regulate the potential between the two will provide guidance for the design of high-performance air-based self-charging batteries. However, most reported self-charging aqueous batteries currently have a cycle life of less than 5 times, making the design of electrode materials with high stability and high capacity imperative.

[0004] Compared to inorganic electrode materials, organic electrode materials exhibit superior electrochemical performance due to their functionalizable design and pre-designed active sites on the framework. In particular, porous aromatic frameworks (PAFs) with high specific surface area and rigid skeletons can better contact oxygen, enabling a more efficient air self-charging process. Furthermore, zinc dendrite growth affects battery life and stability. Current strategies for suppressing dendrite growth include electrolyte additives, which can not only inhibit dendrite growth but also modify the effective coordination strategy of hydrated zinc ions to achieve faster reaction kinetics. Therefore, designing and developing novel organic electrode materials and selecting suitable electrolytes are fundamental to developing superior self-charging batteries. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the problem that batteries cannot be reused in some remote mountainous areas lacking electricity, and to provide a design scheme for self-charging of aqueous zinc-potassium hybrid ion batteries in an air environment.

[0006] The above-mentioned technical problems are solved by the following technical solutions:

[0007] A chemically self-charging aqueous zinc-potassium organic battery cathode material, designated as PAF-305, is a porous aromatic framework material with the following structure:

[0008]

[0009] A method for preparing a positive electrode material for a chemically self-charging aqueous zinc-potassium organic battery includes the following steps:

[0010] 1) Using compounds 1 and 2 as raw materials, compound 3 was synthesized by reflux in a mixed solution of ethanol and acetic acid at 100-140°C for 2-10 hours via a Schiff base reaction. Compound 1 is cyclohexanehexanone octahydrate, and compound 2 is 1,2,4,5-phenyltetramine tetrahydrochloride. The structural formula of the obtained compound 3 is as follows:

[0011]

[0012] 2) Compound 3 and compound 4 are refluxed in an organic solvent, and the reaction is carried out in an inert gas atmosphere to give compound 5; wherein the organic solvent is N-methylpyrrolidone and acetic acid, and compound 4 is 4,5,9,10-pyrenetetrone;

[0013] 3) The obtained compound 5 was thoroughly washed in DMF (N,N-dimethylformamide), water and methanol respectively, and dried under vacuum at 80-100℃ to obtain the porous aromatic framework material PAF-305.

[0014] Preferably, in step 1), the molar ratio of compound 1 to compound 2 is 1:3.0-3.5, and the reaction is carried out in a nitrogen atmosphere.

[0015] Preferably, in step 2), the molar ratio of compound 3 to compound 4 is 1:1.0-1.5; the reaction is carried out in a nitrogen atmosphere.

[0016] An application of a chemically self-charging aqueous zinc-potassium organic battery cathode material is as follows: It is used as a cathode material in the preparation of an aqueous zinc-potassium hybrid ion battery. The steps are as follows:

[0017] 1) PAF-305, acetylene black, and PVDF (polyvinylidene chloride) are ground into a uniform slurry by adding NMP (N-methylpyrrolidone) solvent at a mass ratio of 4:5:1 or 6:3:1, and then uniformly coated onto a stainless steel mesh.

[0018] 2) Place the coated stainless steel mesh in an oven at 85℃ for 12 hours to remove residual solvent;

[0019] 3) Cut the dried stainless steel mesh from step 2) into circular electrode pieces with a diameter of 12mm for later use;

[0020] 4) Battery assembly: Using the 2025 type button cell standard, circular electrode plates, separator, electrolyte, zinc plate, gasket, spring, and positive cell are placed in sequence in the negative electrode shell, and then sealed with a packaging machine to obtain an aqueous zinc ion 2025 type button cell.

[0021] Preferably, in step 4), the electrolyte is an aqueous solution of 12M KOTF and 2M Zn(OTF)2 with a volume of 80-120 μL, and the diaphragm is a glass fiber membrane.

[0022] Beneficial effects:

[0023] 1. The porous aromatic conjugated framework material PAF-305 synthesized in this invention exhibits high specific capacity and good stability as a cathode material in aqueous zinc-potassium hybrid ion batteries, with a specific capacity of 50 mAg. -1 At a current density of 209.9 mAh g, it exhibits a current density of 209.9 mAh g -1 The specific capacity, even at 10Ag -1 Even at a current density of 1600 cycles, it can continue to cycle for 1600 cycles without significant decay.

[0024] 2. PAF-305, as the positive electrode material in an aqueous zinc-potassium hybrid ion battery, adsorbs K+ at its C=N redox active sites in a KOTF+Zn(OTF)2 mixed electrolyte. + Ions enable higher battery specific capacity.

[0025] 3. The PAF-305 material of the present invention is easy to synthesize, and as a positive electrode material for aqueous zinc-potassium hybrid ion batteries, it can achieve air self-charging characteristics under harsh environments. Attached image description:

[0026] Figure 1 FTIR image of porous aromatic framework PAF-305;

[0027] Figure 2 XRD pattern of porous aromatic framework PAF-305;

[0028] Figure 3 SEM image of porous aromatic framework PAF-305;

[0029] Figure 4 PAF-305, a porous aromatic framework, was used as an electrode material for aqueous zinc-potassium hybrid ion batteries at 50 mA hg. -1 Charge-discharge curves at current density;

[0030] Figure 5 Rate performance of porous aromatic framework PAF-305 as an electrode material for aqueous zinc-potassium hybrid ion batteries;

[0031] Figure 6 PAF-305, a porous aromatic framework, was used as an electrode material for aqueous zinc-potassium hybrid ion batteries at 10Ag. -1 Cyclic plot at current density;

[0032] Figure 7 Figures showing multiple air-charge cycles of PAF-305, a porous aromatic framework, as an electrode material for an aqueous zinc-potassium hybrid ion battery.

[0033] Figure 8 Cyclic voltammetry for porous aromatic framework PAF-305 as an electrode material in an aqueous zinc-potassium hybrid ion battery;

[0034] Figure 9 Impedance diagram of porous aromatic framework PAF-305 as an electrode material for aqueous zinc-potassium mixed-ion batteries. Detailed Implementation

[0035] This invention provides a conjugated organic-aqueous zinc-potassium hybrid ion battery electrode material, wherein the electrode material is a porous aromatic framework (PAF-305), and the synthesis route of the porous aromatic framework organic-aqueous zinc-potassium hybrid ion battery electrode material (PAF-305) is as follows:

[0036] Compound 3 was synthesized by reflux in a mixed solution of ethanol and acetic acid using cyclohexanehexaone octahydrate (referred to as compound 1) and 1,2,4,5-phenyltetramine tetrahydrochloride (referred to as compound 2) as starting materials.

[0037]

[0038] Compound 3 and 4,5,9,10-pyrenetetrone (compound 4) were refluxed in acetic acid and N-methylpyrrolidone to give compound 5.

[0039]

[0040] Example 1

[0041] 1) Cyclohexane hexaone octahydrate (225 mg, 0.72 mmol) and 1,2,4,5-phenyltetramine tetrahydrochloride (644 mg, 2.27 mmol) were added to ethanol and acetic acid (4:1, 80-120 mL) under a nitrogen atmosphere, and then refluxed at 100-140 °C for 8-12 h. After cooling to room temperature, the mixture was filtered, and the solid was collected by rotary evaporation to obtain a black solid (designated as compound 3). Finally, the product was dried under vacuum at 100 °C.

[0042] 2) Add the mixture of compound 3 (31.75 mg, 0.038 mmol) and 4,5,9,10-pyrenetetrone (15 mg, 0.057 mmol) to a 5 ml ampoule, and add 0.5-1 ml of acetic acid and 2-3 ml of N-methylpyrrolidone. Purge the ampoule three times and react at 100-140 °C for 48 h.

[0043] 3) After cooling the obtained mixture to room temperature, filter it, wash it thoroughly with N,N-dimethylformamide, water, and methanol, and then dry it under vacuum at 100°C to obtain a black solid, which is the porous aromatic framework PAF-305. The obtained material was characterized by FTIR, XRD, and SEM, and the results are as follows: Figures 1-3 As shown, this proves that PAF-305 was successfully synthesized.

[0044] Example 2

[0045] Aqueous zinc-ion batteries were prepared using PAF-305 synthesized in Example 1 as the positive electrode material. PAF-305, acetylene black, and PVDF were mixed in a mass ratio of 4:5:1 with NMP solvent and ground into a uniform slurry. This slurry was then uniformly coated onto a stainless steel mesh and placed in an oven at 85°C for 12 hours to remove residual solvent. The resulting material was then cut into 12mm diameter circular electrode sheets. Using the 2025 coin cell standard, the circular electrode sheets, separator, electrolyte, zinc sheet, gasket, spring, and positive electrode shell were sequentially placed in the negative electrode shell. The shell was then sealed using a packaging machine to obtain an aqueous zinc-potassium hybrid ion 2025 coin cell. Battery performance was then tested using a Blue Battery testing system. Figure 4As can be seen from the charge-discharge curves, the battery prepared in this invention can achieve a charge-discharge performance of 50 mA g. -1 It exhibits 209.9 mA hg at a current density. -1 The specific capacity was measured, and the rate performance of the PAF-305 electrode was tested at different current densities. The results are as follows: Figure 5 As shown, when the current density reaches 2Ag -1 At that time, the capacity can still reach 109.6 mA hg -1 When the current returns to 100mA g -1 At that time, the capacity can almost return to its initial capacity. At 10A g -1 The stability of the battery was tested at a current density, and the results are as follows: Figure 6 As shown, the capacity shows almost no decay after 1600 cycles. Furthermore, the aqueous zinc-potassium hybrid ion battery assembled using the PAF-305 electrode can withstand numerous air-charge cycles (…). Figure 7 Its total discharge capacity can reach 2783.8 mA hg -1 This results in an energy density of 1670.3 Wh / kg. -1 .according to Figure 8 The CV curves shown indicate two distinct redox peaks, representing two redox processes. The reduction peaks of PAF-305 at 0.89 and 0.8 V correspond to two K... + Embedding. To study the kinetic behavior of the battery, impedance tests were performed on the battery, and the results are as follows: Figure 9 As shown, the smaller transfer resistance ensures the battery's excellent performance.

Claims

1. A chemically self-charging aqueous zinc-potassium organic battery cathode material, which is a porous aromatic framework material, designated PAF-305, has the following structure: 。 2. A method for preparing the positive electrode material of a chemically self-charging aqueous zinc-potassium organic battery according to claim 1, comprising the following steps: 1) Using compounds 1 and 2 as raw materials, compound 3 was synthesized by reflux in a mixed solution of ethanol and acetic acid at 100-140°C for 2-10 hours via a Schiff base reaction. Compound 1 is cyclohexanehexanone octahydrate, and compound 2 is 1,2,4,5-phenyltetramine tetrahydrochloride. The structural formula of the obtained compound 3 is as follows: ； 2) Compound 3 and compound 4 are refluxed in an organic solvent, and the reaction is carried out in an inert gas atmosphere to give compound 5; wherein the organic solvent is N-methylpyrrolidone and acetic acid, and compound 4 is 4,5,9,10-pyrenetetrone; 3) The obtained compound 5 was thoroughly washed in DMF, water and methanol respectively, and dried under vacuum at 80-100℃ to obtain the porous aromatic framework material PAF-305.

3. The method for preparing a chemically self-charging aqueous zinc-potassium organic battery cathode material according to claim 2, characterized in that, In step 1), the molar ratio of compound 1 to compound 2 is 1:3.0-3.5, and the reaction is carried out in a nitrogen atmosphere.

4. The method for preparing a chemically self-charging aqueous zinc-potassium organic battery cathode material according to claim 2, characterized in that, In step 2), the molar ratio of compound 3 to compound 4 is 1:1.0-1.5; the reaction is carried out in a nitrogen atmosphere.

5. The application of the chemically self-charging aqueous zinc-potassium organic battery cathode material according to claim 1 is as a cathode material in the preparation of an aqueous zinc-potassium hybrid ion battery, comprising the following steps: 1) PAF-305, acetylene black, and PVDF are mixed in a mass ratio of 4:5:1 or 6:3:1 with NMP solvent and ground into a uniform slurry. Then, the slurry is uniformly coated onto a stainless steel mesh. 2) Place the coated stainless steel mesh in an oven at 85℃ for 12 hours to remove residual solvent; 3) Cut the dried stainless steel mesh from step 2) into circular electrode pieces with a diameter of 12 mm for later use; 4) Battery assembly: Using the 2025 type button cell standard, circular electrode plates, separator, electrolyte, zinc plate, gasket, spring, and positive cell are placed in sequence in the negative electrode shell, and then sealed with a packaging machine to obtain an aqueous zinc ion 2025 type button cell.

6. The application of the chemically self-charging aqueous zinc-potassium organic battery cathode material according to claim 5, characterized in that, In step 4), the electrolyte is an aqueous solution of 12M KOTF and 2M Zn(OTF)2 with a volume of 80-120 μL, and the diaphragm is a glass fiber membrane.

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