Organic electrode material, preparation method thereof and high-performance aqueous aluminum ion battery

Abstract

This invention discloses an organic electrode material, relating to the field of battery technology. The molecular structure of the organic electrode material is as follows: This invention also provides a method for preparing the above-mentioned organic electrode material and a high-performance aqueous aluminum-ion battery prepared using the organic electrode material. The raw materials used in this invention are green and environmentally friendly, inexpensive, and the preparation process is simple, showing good application prospects. Furthermore, when this organic electrode material is used to make the positive electrode of an aluminum-ion battery, it exhibits excellent specific capacity, good rate performance, and outstanding long-cycle stability, giving the aqueous aluminum-ion battery excellent electrochemical performance. Therefore, this invention provides an attractive pathway for the sustainable and large-scale energy storage of ion batteries.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to an organic electrode material and its preparation method, and a high-performance aqueous aluminum-ion battery. Background Technology

[0002] The increasing cost, environmental unfriendliness, and safety risks of lithium-ion batteries have limited their further development. Consequently, aqueous rechargeable batteries based on non-flammable electrolytes, such as aluminum-ion batteries, have gained more attention. According to existing data, aluminum is currently the most abundant metal among metals, and rechargeable aluminum-ion batteries (AIBs) are particularly promising due to their high theoretical capacity and the presence of aluminum. 3+ The favorable potential of / Al also endows it with enormous large-scale energy storage capabilities.

[0003] Currently, electrode materials are divided into organic and inorganic electrode materials. Inorganic electrode materials have the advantage of high specific capacity, but they suffer from limited resources and structural collapse. Furthermore, the vast application market poses significant challenges to the sustainability and cost of inorganic electrode materials (especially cathode materials). Organic electrode materials, on the other hand, exhibit advantages such as renewability, environmental friendliness, low cost, and high capacity due to their abundant carbon, hydrogen, and oxygen content. Therefore, they have attracted widespread attention in recent years; aluminum batteries using organic electrode materials offer an attractive pathway for sustainable and large-scale energy storage.

[0004] Previous studies have shown that the following factors need to be considered when using materials for the cathode of aluminum batteries:

[0005] 1. Can the material's electrochemical performance indicators, such as energy density, power density, and cycle life, meet the requirements of practical applications?

[0006] 2. What are the costs, resource availability, and thermal / chemical stability of electrode materials used in large-scale electrochemical energy storage applications?

[0007] However, traditional organic materials are not well-suited to meet the above requirements due to their limited active sites, structural instability, and slow redox kinetics. In other words, the application of traditional organic materials in aluminum battery cathodes is quite limited and difficult to promote on a large scale. Summary of the Invention

[0008] This invention discloses an organic electrode material, its preparation method, and a high-performance aqueous aluminum-ion battery, which can solve the problem that traditional organic materials are greatly limited when applied to the positive electrode of aluminum batteries due to defects such as limited active sites, structural instability, and redox kinetics.

[0009] The technical solution adopted in this invention is as follows:

[0010] One objective of this invention is to provide an organic electrode material with the following molecular structural formula:

[0011]

[0012] The second objective of this invention is to provide a method for preparing the above-mentioned organic electrode material, which is obtained by a one-step dehydration condensation reaction of 1,10-o-diazaphenanthroline-5,6-dione and 2,3-diaminonaphthalene-1,4-dione.

[0013] Specifically, the specific process of the one-step dehydration condensation reaction is as follows:

[0014] Step 1: Add 1,10-o-diazaphenanthroline-5,6-dione and 2,3-diaminonaphthalene-1,4-dione to an ethanol / acetic acid solution with a volume ratio of 1:1, and sonicate until the solids are completely dissolved to obtain a mixed solution; the molar ratio of 1,10-o-diazaphenanthroline-5,6-dione and 2,3-diaminonaphthalene-1,4-dione is 0.8 to 1:1 to 1.2.

[0015] Step 2: Stir and heat the mixed solution to allow 1,10-o-diazanphenanthroline-5,6-dione and 2,3-diaminonaphthalene-1,4-dione to react completely, and then cool to room temperature;

[0016] Step 3: The solution obtained in Step 2 is filtered to obtain the target solid, which is then washed and dried to obtain the organic electrode material.

[0017] Furthermore, in step 2, the reaction conditions are 70-80℃ and 150-200rpm.

[0018] Furthermore, in step 3, after filtration, the target solid is washed sequentially with ethanol, acetic acid, and water.

[0019] The third objective of this invention is to provide a high-performance aqueous aluminum-ion battery, comprising a positive electrode, a negative electrode, a separator, and an electrolyte, wherein the positive electrode is made of the organic electrode material described in claim 1.

[0020] Specifically, the preparation process of the positive electrode is as follows:

[0021] Step a: Mix and grind the organic electrode material, conductive agent and binder in a weight ratio of 7:2:1 to form a uniform slurry;

[0022] Step b: Coat the slurry evenly onto the titanium foil current collector, and then dry it to obtain the positive electrode.

[0023] Further, step a specifically involves: weighing the organic electrode material, conductive agent, and binder separately and placing them into an agate mortar, then adding 2-5 ml of N-methyl-2-pyrrolidone, and continuously grinding to form a uniform slurry.

[0024] Preferably, the conductive agent is Ketjen Black.

[0025] Preferably, the adhesive is polyvinylidene fluoride.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] (1) 1,10-o-diazaphenanthroline-5,6-dione is mainly used to prepare molecules with specific functions, synthetic drug precursors, and catalytic reaction materials. Due to the presence of two pyridine ligands, 1,10-o-diazaphenanthroline-5,6-dione can form stable complexes with various transition metals. These metal complexes can act as catalysts in chemical reactions, promoting specific conversion processes. This invention utilizes the above-mentioned properties of 1,10-o-diazaphenanthroline-5,6-dione and applies it to organic electrode materials. This invention designs the component ratio and reaction parameters to enable it to undergo a one-step dehydration condensation reaction with 2,3-diaminonaphthalene-1,4-dione in a strongly polar organic solvent, thereby constructing a novel organic electrode material. The organic electrode material constructed in this invention has a large number of abundant C=N and C=O bonds, which can serve as cation storage sites. At the same time, experiments show that this organic electrode material also has a small charge transfer impedance and a high ion diffusion coefficient, indicating that it has rapid redox kinetics and can achieve reversible cation storage. Therefore, based on the above characteristics, when this organic electrode material is used as the positive electrode material of an aqueous aluminum-ion battery, it can exhibit high specific capacity, excellent cycle stability and rate performance, thus enabling the aqueous aluminum-ion battery to have excellent electrochemical performance.

[0028] (2) The organic electrode material prepared by this invention is not only inexpensive and environmentally friendly, but also uses a one-step dehydration condensation reaction technology, which simplifies the preparation process, eliminates the need for multiple purification steps, and ensures high purity and structural consistency of the product. Therefore, this invention provides a feasible strategy for the green and low-cost application of organic materials in aluminum-ion batteries, and has excellent application prospects, making it very suitable for large-scale promotion. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the synthesis of the organic electrode material obtained in Example 1 of the present invention.

[0030] Figure 2 This is the Fourier transform infrared spectrum of the organic electrode material obtained in Example 1 of the present invention.

[0031] Figure 3 This is a thermogravimetric analysis diagram of the organic electrode material obtained in Example 1 of the present invention.

[0032] Figure 4 This is a scanning electron microscope image of the organic electrode material obtained in Example 1 of the present invention.

[0033] Figure 5 The aluminum-ion battery in Example 3 of this invention has a voltage of 0.1 mV·s. -1 Cyclic voltammetry curves at scan rate.

[0034] Figure 6 This is a rate performance diagram of the aluminum-ion battery in Example 3 of the present invention.

[0035] Figure 7 The aluminum-ion battery in Example 3 of this invention is at 0.1 A·g -1 The constant current charge and discharge curves are shown below.

[0036] Figure 8 This is the impedance diagram of the aluminum-ion battery in Example 3 of the present invention.

[0037] Figure 9 This is a GITT diagram of the aluminum-ion battery under different charge and discharge states in Example 3 of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to various embodiments.

[0039] Example 1

[0040] This embodiment provides an organic electrode material (Nqphen) obtained by a one-step dehydration condensation reaction of 1,10-o-diazaphenanthroline-5,6-dione and 2,3-diaminonaphthalene-1,4-dione, and its molecular structure is as follows:

[0041]

[0042] The preparation process of the organic electrode material in this embodiment is as follows:

[0043] Weigh out 1 mmol of 1,10-o-phenanthroline-5,6-dione, 1.2 mmol of 2,3-diaminonaphthalene-1,4-dione, and 150 mL of ethanol / acetic acid (ethanol:acetic acid volume ratio 1:1) and add them to a 250 mL three-necked flask. Sonicate for 15 minutes until the solids are completely dissolved. Then, place the three-necked flask in an oil bath and heat with stirring at 70 °C, 200 rpm, for 12 h. The relevant reaction equations are as follows: Figure 1 As shown.

[0044] After the reaction is complete, cool to room temperature, then filter, and wash with ethanol, acetic acid and water in sequence to obtain a pale yellow solid (target solid). Finally, dry in a vacuum oven to obtain the final product.

[0045] Figure 2 The image shows the Fourier transform infrared spectrum of the organic electrode material obtained in this embodiment. It can be observed from the image that the absorption peak of the stretching vibration of the -NH2 bond in Nq disappears; simultaneously, the retention of the C=N bond and the appearance of the C=O bond in phen both demonstrate the successful synthesis of Nqphen.

[0046] Figure 3 The image shows the thermogravimetric analysis (TGA) of the organic electrode material obtained in this embodiment. It can be seen that it exhibits good structural thermal stability.

[0047] Figure 4 The image shows a scanning electron microscope image (scale bar is 10.0 μm) of the organic electrode material obtained in this embodiment. As can be seen from the image, it has a uniform sheet-like structure.

[0048] Example 2

[0049] The difference from Example 1 is that in this example, 0.8 mmol of 1,10-o-diazaphenanthroline-5,6-dione, 1 mmol of 2,3-diaminonaphthalene-1,4-dione, and 120 mL of ethanol / acetic acid (volume ratio 1:1) were weighed and added to a 250 mL three-necked flask, and sonicated for 10 minutes until the solids were completely dissolved. Then, the three-necked flask was placed in an oil bath and heated with stirring at 80°C and 150 rpm for 10 hours. The remaining steps and parameters were the same as in Example 1.

[0050] The organic electrode material obtained in this embodiment also has good structural thermal stability and a uniform sheet structure.

[0051] Example 3

[0052] This embodiment provides a high-performance aqueous aluminum-ion battery, whose positive electrode sheet is prepared using the organic electrode material (Nqphen) obtained in Example 1. The specific process is as follows:

[0053] 1. Preparation of the positive electrode sheet:

[0054] Nqphen, Ketjen black, and polyvinylidene fluoride (in a weight ratio of 7:2:1) were weighed and placed into an agate mortar. Then, 5 ml of N-methyl-2-pyrrolidone was added and the mixture was continuously ground to form a uniform slurry. The slurry was then uniformly coated onto a titanium foil current collector and finally dried in a vacuum oven at 80-100℃ for 20-26 hours to produce a positive electrode sheet.

[0055] 2. Battery fabrication:

[0056] A positive electrode sheet is used as the positive electrode, an aluminum foil is used as the negative electrode, and a glass fiber membrane is placed between the positive and negative electrodes to separate them. 1M Al(ClO4)3 electrolyte is added to assemble a button cell.

[0057] Figure 5 The aluminum-ion battery obtained in this embodiment has a voltage rating of 0.1 mV·s. -1 Cyclic voltammetry curves at different scan rates. It can be seen that there are two distinct pairs of redox peaks, and the peak shapes are completely identical at different scan rates, indicating that this aluminum-ion battery has good reversibility.

[0058] Figure 6 This is a rate performance graph of the aluminum-ion battery obtained in this embodiment. As can be seen from the graph, at rates of 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.7, and 1.0 A·g... -1 At the given current densities, the battery capacities were 265, 234, 216, 194, 173, 157, 139, and 113 mAh·g, respectively. -1 The specific capacity. When the current density recovers to 0.1 A·g -1 When the battery's specific capacity can recover to its original value, it indicates that the positive electrode material used in this embodiment has high reversibility.

[0059] Figure 7 The aluminum-ion battery obtained in this embodiment is at 0.1 A·g -1 The constant current charge-discharge curves are shown below. According to the charge-discharge curves, the positive electrode material used in this embodiment exhibits a high initial specific capacity and a distinct charge-discharge plateau, corresponding to the cyclic voltammetry curves.

[0060] Figure 8 The image shows the impedance diagram of the aluminum-ion battery obtained in this embodiment. It can be seen that the charge transfer impedance (Rct, the semi-circular diameter in the high-frequency band) of this aluminum-ion battery is relatively small, indicating that it has the ability to transfer charges rapidly.

[0061] Figure 9 The GITT plots of the aluminum-ion battery obtained in this embodiment under different charge-discharge states are shown. The GITT plots show that the cations have high diffusion coefficients under different charge-discharge states, indicating that the aluminum-ion battery has a high ion diffusion coefficient.

[0062] In summary, this invention designs an organic electrode material with C=O and C=N as active sites, endowing it with high reversible capacity and rapid charge transfer capability. These characteristics make this organic electrode material show great potential for application as a cathode material in aluminum-ion batteries. Therefore, compared with the prior art, this invention represents a significant technological advancement, possessing outstanding substantive features and remarkable progress.

[0063] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. An aqueous aluminum-ion battery, comprising a positive electrode, a negative electrode, a separator, and an electrolyte, characterized in that, The positive electrode is made of an organic electrode material with the following molecular structure: 。 2. The aqueous aluminum-ion battery according to claim 1, characterized in that, The preparation process of the positive electrode is as follows: Step a: Mix and grind the organic electrode material, conductive agent and binder in a weight ratio of 7:2:1 to form a uniform slurry; Step b: Coat the slurry evenly onto the titanium foil current collector, and then dry it to obtain the positive electrode.

3. The aqueous aluminum-ion battery according to claim 2, characterized in that, Step a specifically involves weighing the organic electrode material, conductive agent, and binder separately and placing them into an agate mortar. Then, 2-5 ml of N-methyl-2-pyrrolidone is added, and the mixture is continuously ground to form a uniform slurry.

4. The aqueous aluminum-ion battery according to claim 2 or 3, characterized in that, The conductive agent is Ketjen Black.

5. The aqueous aluminum-ion battery according to claim 4, characterized in that, The adhesive is polyvinylidene fluoride.

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