Electropolymer of polycarbonyl dihydropyrazine derivatives, process for the preparation and use thereof

Abstract

The application discloses a polycarbonyl dihydropyrazine derivative electric polymer and a preparation method and application thereof, and belongs to the technical field of organic molecule electrochemical polymerization and water-based zinc ion battery electrode material preparation. The preparation method is simple, controllable, low in cost, and extremely short in time consumption. The conductive polymer is in-situ grown on the electrode surface, is closely combined, and is not easy to fall off. In addition, no binder needs to be added, so that the internal resistance is reduced, and the activity and stability of the cathode material are improved. The organic matter is polymerized by using an electrochemical method, a free radical polymerization process is generated, and the preparation of the organic molecule electric polymer is realized. The organic molecule electric polymer obtained in the application can realize high conductivity, high specific capacity and long cycle life of the material when being used as a cathode material of a water-based zinc ion battery.

Description

Technical Field

[0001] This invention belongs to the field of organic molecular electrochemical polymerization and aqueous zinc-ion battery electrode material preparation technology, specifically relating to an electropolymer of a polycarbonyl dihydropyrazine derivative, its preparation method and application. Background Technology

[0002] Aqueous zinc-ion batteries are emerging in the energy storage field with unique advantages. The zinc anode in aqueous zinc-ion batteries has a relatively low redox potential and a high theoretical capacity, which is beneficial for achieving higher battery charge-discharge efficiency and greater energy storage. Furthermore, zinc is a widely available and relatively inexpensive metal, giving aqueous zinc-ion batteries greater potential for commercial applications. Compared to traditional lithium-ion batteries, aqueous zinc-ion batteries are also favored for their high safety and environmental friendliness.

[0003] In zinc-ion batteries, the cathode material serves as the central element for energy conversion and storage, and its performance directly determines the charge-discharge efficiency and stability of the entire battery system. In the field of zinc-ion batteries, inorganic cathode materials have been extensively researched and applied, including transition metal oxides (such as V₂O₅ and MnO₂) and transition metal dichalcogenides (such as MoS₂ and VS₂). These inorganic materials play a crucial role in improving battery energy density and extending cycle life due to their diverse structural types and excellent electrochemical performance. However, these inorganic electrode materials may cause serious environmental problems due to their heavy metal content, and some inorganic cathode materials undergo volume changes during charge-discharge processes, thus affecting battery life and performance. Some low-conductivity inorganic cathode materials also require additional conductive additives, thereby increasing battery costs.

[0004] In recent years, organic cathode materials have attracted widespread attention due to their unique structural diversity, tunability, and renewability. Among them, organic carbonyl compounds, as high-performance electrode materials, can realize low-cost, environmentally friendly, flexible, and rechargeable energy storage systems. However, the inherent low conductivity and high solubility of organic electrode materials limit the realization of high-performance aqueous zinc-ion batteries. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide an electropolymer of polycarbonyl dihydropyrazine derivatives, its preparation method and application, so as to solve the technical problems that the inherent low conductivity and high solubility of existing organic cathode materials limit the realization of high-performance aqueous zinc-ion batteries.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention discloses a method for preparing an electropolymer of a polycarbonyl dihydropyrazine derivative, comprising the following steps:

[0008] S1: Mix organic molecules and electrolyte to obtain a mixed electrolyte;

[0009] S2: A working electrode, a counter electrode, and a reference electrode are placed in a mixed electrolyte, and an electropolymer of a polycarbonyl dihydropyrazine derivative is formed on the working electrode by electrochemical polymerization.

[0010] Further, in S1, the organic molecule is 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone; and the electrolyte is a sulfuric acid solution.

[0011] Furthermore, the concentration of 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone in the mixed electrolyte is 1–10 mM;

[0012] The concentration of the sulfuric acid solution is 0.1M.

[0013] Further, in S2, the electrochemical polymerization method includes:

[0014] Cyclic voltammetry: voltage range 2.0 to (-1.0) V relative to a saturated calomel electrode, scan rate 1 to 500 mV·s -1 ;

[0015] Constant current method: current range 1~100mA·cm -2 The time range is 20 to 120 minutes;

[0016] Potentiostatic method: voltage not less than 1.8V relative to saturated calomel electrode, time range 20-120min.

[0017] Furthermore, in S2, the working electrode is carbon cloth.

[0018] Furthermore, in S2, the reference electrode is a calomel electrode.

[0019] Furthermore, in S2, the counter electrode is a graphite electrode.

[0020] The present invention also discloses an electropolymer of a polycarbonyl dihydropyrazine derivative prepared by the above preparation method.

[0021] Furthermore, the electropolymer of the polycarbonyl dihydropyrazine derivative is a 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone electropolymer.

[0022] The present invention also discloses the application of the above-mentioned polycarbonyl dihydropyrazine derivatives, wherein the electropolymer of the polycarbonyl dihydropyrazine derivatives is loaded on carbon cloth and used as an electrode material in an aqueous zinc-ion battery as a cathode material for energy storage and conversion.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention discloses a method for preparing an electropolymer of a polycarbonyl dihydropyrazine derivative. The method utilizes electrochemical polymerization, in which the polymer grows in situ on the electrode surface, resulting in a tight bond that is not easily detached. The entire preparation process is simple and controllable, low in cost, and extremely short in time. Furthermore, no binder is required, thereby reducing internal resistance and improving the activity and stability of the cathode material.

[0025] Furthermore, the present invention utilizes an electrochemical method to polymerize the organic compound 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone, which undergoes a free radical polymerization process, thereby achieving the preparation of the electropolymer of 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone.

[0026] The present invention also discloses an electropolymer of polycarbonyl dihydropyrazine derivatives prepared by the above preparation method, which can achieve high specific capacity and long cycle life when used as a cathode material for aqueous zinc-ion batteries. Since the material is prepared by electrochemical polymerization of organic molecules, the stability and high conductivity of the material can be guaranteed, thereby realizing the preparation of an electrode material with excellent performance. Attached Figure Description

[0027] Figure 1 Structural diagram of the organic molecule in Example 1: 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone;

[0028] Figure 2 The image shows the X-ray photoelectron spectroscopy (XPS) spectrum of the 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone electropolymer grown on carbon cloth in Example 1.

[0029] Figure 3 The image shows a scanning electron microscope (SEM) image of the 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone electropolymer prepared in Example 1 and grown on carbon cloth.

[0030] Figure 4 The CV diagram shows the 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone electropolymer grown on carbon cloth as prepared in Example 1.

[0031] Figure 5 The rate curve shows the rate of use of the 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone electropolymer grown on carbon cloth in Example 1 as a cathode material for an aqueous zinc-ion battery. Detailed Implementation

[0032] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0033] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0034] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0035] In this article, unless otherwise specified, the terms “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of”. For example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a”.

[0036] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0037] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0038] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0039] Example 1

[0040] A method for preparing an electropolymer of a polycarbonyl dihydropyrazine derivative includes the following steps:

[0041] S1: Add 1 mM of 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone to 20 mL of 0.1 M sulfuric acid solution and stir thoroughly to form a mixed electrolyte;

[0042] S2: Use carbon cloth as the working electrode, graphite rod electrode as the counter electrode, and saturated calomel electrode as the reference electrode.

[0043] The electrochemical instrument used was a CHI660E electrochemical workstation (Shanghai Chenhua Instrument Co., Ltd.), employing a standard one-compartment three-electrode system. Cyclic voltammetry was used for the electrochemical experiments, with a positive potential of 2.0 V, a negative potential of -1.0 V, and a scan rate of 0.1 V s. -1 After 40 cycles, a 6,9-dihydropyrazine[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone electropolymer is formed on the working electrode. The electrode is then post-treated to obtain the electrode material.

[0044] The organic molecule is 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone, the structure of which is described in [reference needed]. Figure 1 ;

[0045] Figure 2 The image shows the X-ray photoelectron spectroscopy (XPS) spectrum of the 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraketone electropolymer grown on carbon cloth in Example 1. The presence of C, O, N and S indicates the successful preparation of the 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraketone electropolymer.

[0046] Figure 3This is a scanning electron microscope (SEM) image of the 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone electropolymer grown on carbon cloth prepared in Example 1. As can be seen from the image, there is polymer attached to the carbon fiber surface.

[0047] See Figure 4 , Figure 4 The 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone electropolymer prepared in Example 1 and grown on carbon cloth at 0.1 V s -1 Scan rate and CV test graph in 1M zinc trifluoromethanesulfonate solution, with the working electrode immersed in the electrolyte solution by 1 cm. 2 ,from Figure 4 As can be seen, the polymer has obvious redox peaks.

[0048] See Figure 5 , Figure 5 This is a rate profile of the 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone electropolymer grown on carbon cloth in Example 1, used as a cathode material in an aqueous zinc-ion battery. Figure 5 It can be seen that when this polymer is used as a cathode material for aqueous zinc-ion batteries, even at 10 A g... -1 It still maintains a high specific capacity at current densities, and when the current density recovers to 0.1 A g... -1 The ability to recover to near the initial capacity indicates that the polymer has excellent electrochemical performance when used as a cathode material for aqueous zinc-ion batteries.

[0049] Example 2

[0050] A method for preparing an electropolymer of a polycarbonyl dihydropyrazine derivative includes the following steps:

[0051] S1: Add 1 mM of 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone to 20 mL of 0.1 M sulfuric acid solution and stir thoroughly to form a mixed electrolyte;

[0052] S2: Use carbon cloth as the working electrode, graphite rod electrode as the counter electrode, and saturated calomel electrode as the reference electrode;

[0053] The electrochemical instrument used was a CHI660E electrochemical workstation (Shanghai Chenhua Instrument Co., Ltd.), which adopted a standard one-chamber three-electrode system. Electrochemical experiments were conducted in constant potential mode. Electropolymerization was carried out at a constant potential of 2V for 40 min to form 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraketone electropolymer.

[0054] Example 3

[0055] A method for preparing an electropolymer of a polycarbonyl dihydropyrazine derivative includes the following steps:

[0056] S1: Add 1 mM of 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone to 20 mL of 0.1 M sulfuric acid aqueous solution and stir thoroughly to form a mixed electrolyte;

[0057] S2: Use carbon cloth as the working electrode, graphite rod electrode as the counter electrode, and saturated calomel electrode as the reference electrode.

[0058] The electrochemical instrument used was a CHI660E electrochemical workstation (Shanghai Chenhua Instrument Co., Ltd.), employing a standard one-chamber three-electrode system. Electrochemical experiments were conducted using constant current mode at 0.01 A·cm⁻¹. -2 Electrochemical polymerization under constant current for 40 min yielded a 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraketone electropolymer.

[0059] Example 4

[0060] Unlike Example 1, the concentration of 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone in the mixed electrolyte in this example is 10 mM, while the other parameters and preparation steps are the same as in Example 1.

[0061] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for preparing an electropolymer of a polycarbonyl dihydropyrazine derivative, characterized in that, Includes the following steps: S1: Mix the organic molecule and the electrolyte to obtain a mixed electrolyte; the organic molecule is 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone; the electrolyte is a sulfuric acid solution; S2: A working electrode, a counter electrode, and a reference electrode are placed in a mixed electrolyte, and an electropolymer of a polycarbonyl dihydropyrazine derivative is formed on the working electrode by electrochemical polymerization.

2. The method for preparing an electropolymer of a polycarbonyl dihydropyrazine derivative according to claim 1, characterized in that, The concentration of 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone in the mixed electrolyte is 1~10mM; The concentration of the sulfuric acid solution is 0.1 M.

3. The method for preparing an electropolymer of a polycarbonyl dihydropyrazine derivative according to claim 1, characterized in that, In S2, the electrochemical polymerization method includes: Cyclic voltammetry: voltage range 2.0~(-1.0) V relative to a saturated calomel electrode, scan rate 1~500 mV s -1 ; Constant current method: current range 1~100 mA cm -2 The time range is 20 to 120 minutes. Potentiostatic method: voltage not less than 1.8 V relative to saturated calomel electrode, time range 20~120 min.

4. The method for preparing an electropolymer of a polycarbonyl dihydropyrazine derivative according to claim 1, characterized in that, In S2, the working electrode is carbon cloth.

5. The method for preparing an electropolymer of a polycarbonyl dihydropyrazine derivative according to claim 1, characterized in that, In S2, the reference electrode is a calomel electrode.

6. The method for preparing an electropolymer of a polycarbonyl dihydropyrazine derivative according to claim 1, characterized in that, In S2, the counter electrode is a graphite electrode.

7. An electropolymer of a polycarbonyl dihydropyrazine derivative, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 6.

8. The electropolymer of a polycarbonyl dihydropyrazine derivative according to claim 7, characterized in that, The electropolymer of the polycarbonyl dihydropyrazine derivative is a 6,9-dihydropyrazino[2,3-g]quinoxaline-2,3,7,8(1H,4H)-tetraone electropolymer.

9. The application of the electropolymer of the polycarbonyl dihydropyrazine derivative according to claim 7, characterized in that, The electropolymer of the polycarbonyl dihydropyrazine derivative is loaded onto carbon cloth and used as an electrode material in an aqueous zinc-ion battery as a cathode material for energy storage and conversion.

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