Preparation method, product and application of Ga-MOF electrode material with fluorescence characteristic

Abstract

The invention relates to the technical field of nano electrode materials, in particular to a preparation method, a product and application of a Ga-MOF electrode material with fluorescence characteristics. The preparation method of the Ga-MOF electrode material comprises the following steps: adding a terephthalic acid solution into a gallium salt solution, and uniformly mixing to obtain a mixed solution; and carrying out hydrothermal reaction on the mixed solution, drying, and calcining to obtain the Ga-MOF electrode material. The Ga-MOF electrode material with the fluorescence characteristic is prepared through the hydrothermal reaction, the preparation method is simple, the process is easy to control, and industrial preparation is facilitated. The Ga-MOF electrode material prepared by the method disclosed by the invention has a fluorescent characteristic and a porous structure, shows relatively high specific capacity and long cycle life when being applied to a lithium ion battery, and has application potential in the fields of lithium ion battery and sodium ion battery negative electrode materials.

Description

Technical Field

[0001] The present invention relates to the technical field of nano-electrode materials, and in particular to a preparation method, product and application of a Ga-MOF electrode material with fluorescent properties. Background Art

[0002] With the large-scale consumption of traditional fossil fuels, the development of new clean energy sources has become inevitable. As a core energy storage technology, the performance optimization of lithium-ion batteries (LiBs) has become a research focus. Anode materials play a key role in lithium-ion storage and transmission within battery systems, directly impacting the battery's energy density, cycle life, and safety. Therefore, the development of high-performance, low-cost anode materials for lithium-ion batteries has become an inevitable trend. Summary of the Invention

[0003] The present invention aims to provide a method for preparing a fluorescent Ga-MOF electrode material, as well as a product and application thereof, to improve the problems of low capacity and short cycle life of the electrode material. The Ga-MOF electrode material prepared using the present method exhibits certain fluorescent properties and exhibits excellent long cycle life.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a method for preparing a Ga-MOF electrode material having fluorescent properties, comprising the following steps:

[0006] adding the terephthalic acid solution to the gallium salt solution and mixing to obtain a mixed solution;

[0007] The mixed solution is subjected to a hydrothermal reaction, dried, and then calcined to obtain the Ga-MOF electrode material.

[0008] The present invention also provides a Ga-MOF electrode material prepared by the above preparation method.

[0009] The present invention also provides a secondary battery comprising a positive electrode material, a negative electrode material, an electrolyte and a separator;

[0010] The negative electrode material includes the above-mentioned Ga-MOF electrode material.

[0011] The present invention discloses the following technical effects:

[0012] The present invention adopts hydrothermal reaction to prepare Ga-MOF electrode material with fluorescent characteristics. The preparation method is simple, the process is easy to control, and it is conducive to industrial preparation.

[0013] The Ga-MOF electrode material prepared by the method of the present invention has certain fluorescence characteristics. When it is applied to lithium ion batteries, the Ga-MOF electrode material has a fluorescence characteristic of 0.5Ag. -1 After 1500 cycles at the current density, it still shows a high reversible specific capacity and long cycle life; the Ga-MOF electrode material with fluorescent properties of the present invention has application potential in the field of negative electrode materials for lithium ion batteries and sodium ion batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 This is the XRD pattern of the Ga-MOF electrode material prepared in Example 1 of the present invention.

[0016] Figure 2 This is a TEM image of the Ga-MOF electrode material prepared in Example 1 of the present invention.

[0017] Figure 3 This is a fluorescence emission spectrum of the Ga-MOF electrode material prepared in Example 1 of the present invention.

[0018] Figure 4 This is a cycle performance curve of the Ga-MOF electrode material prepared in Example 1 of the present invention.

[0019] Figure 5 This is the XRD pattern of the electrode material prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0020] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0021] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0022] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0023] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0024] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0025] Metal-organic frameworks (MOFs) are hybrid functional materials constructed from metal ions (clusters) and organic linkers. Due to their high specific surface area, tunable pore structure and diverse chemical functions, they have shown great potential in the field of energy storage (such as fuel cells, supercapacitors and lithium-ion batteries, etc.), especially in the fields of lithium-ion batteries and sodium-ion batteries.

[0026] Taking into account the inherent advantages of metal-organic framework materials, the present invention proposes a method for preparing Ga-MOF nanomaterials with fluorescent properties, namely: utilizing the fluorescent properties of the material to improve the electron transmission ability of the electrode material during the charging and discharging process, increase the interaction between the electrode and the electrolyte, and thus improve the kinetic performance of the electrode reaction; at the same time, the nanoscale pores or gaps in the present invention can effectively inhibit the volume expansion and structural collapse of the electrode material during the charging and discharging process, improve the ion diffusion and transmission capacity, and thus improve the electrochemical performance of the battery.

[0027] Using terephthalic acid as an organic ligand, water and ethanol as solvents, a hydrothermal method combined with a heat treatment process was used to prepare a porous Ga-MOF electrode material with fluorescent properties. The unique fluorescent properties of the material improve the conductivity of the electrode material. At the same time, the rich porous structure can expand the contact area between the electrode and the electrolyte, effectively reducing the Li-ion battery charge and discharge process. + The shorter diffusion distance is more conducive to ion migration and lithium ion storage, thereby improving the electrochemical properties of the material.

[0028] The present invention provides a method for preparing a Ga-MOF electrode material having fluorescent properties, comprising the following steps:

[0029] Adding the terephthalic acid solution (solution B) to the gallium salt solution (solution A) and mixing them to obtain a mixed solution;

[0030] The mixed solution is subjected to a hydrothermal reaction, dried, and then calcined to obtain the Ga-MOF electrode material.

[0031] In a preferred embodiment of the present invention, the solvent of the terephthalic acid solution is an alkaline solution.

[0032] The terephthalic acid solution is prepared by dissolving terephthalic acid in an alkaline solution. The alkaline solution can enhance the solubility of terephthalic acid, provide a certain alkaline environment for the coordination reaction, and is more conducive to the smooth progress of the reaction. The present invention does not impose any particular limitation on the amount of the alkaline solution used. The amount of the alkaline solution used can fully dissolve the terephthalic acid and ensure the smooth progress of the subsequent hydrothermal reaction.

[0033] In a preferred embodiment of the present invention, the alkaline solution is a 1.6 M NaOH solution.

[0034] In a preferred embodiment of the present invention, the solvent of the gallium salt solution is a mixture of water and ethanol in a volume ratio of 2:1; and the gallium salt in the gallium salt solution is gallium nitrate.

[0035] The gallium salt solution is prepared by dissolving the gallium salt in a solvent (a mixture of water and ethanol in a volume ratio of 2:1). The present invention does not impose any particular limitation on the amount of the solvent used, as long as the amount of the solvent can fully dissolve the gallium salt and ensure the smooth progress of the subsequent hydrothermal reaction.

[0036] In a preferred embodiment of the present invention, the mass ratio of the gallium salt in the gallium salt solution to the terephthalic acid in the terephthalic acid solution is 1:5 to 5:1, and more preferably 1.2:1.

[0037] In a preferred embodiment of the present invention, the temperature of the hydrothermal reaction is 120-180° C., and the time is 8-15 hours.

[0038] In a preferred embodiment of the present invention, the calcination temperature is 300-480° C. and the calcination time is 1-5 hours.

[0039] The present invention also provides a Ga-MOF electrode material prepared by the above preparation method.

[0040] The present invention also provides a secondary battery comprising a positive electrode material, a negative electrode material, an electrolyte and a separator;

[0041] The negative electrode material includes the above-mentioned Ga-MOF electrode material.

[0042] Unless otherwise specified, the technical solutions described in the present invention are all conventional solutions in the field, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0043] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0044] Example 1

[0045] First, dissolve 3g Ga(NO3)3·xH2O in 50mL L 水 ∶V 乙醇 =2:1 mixed solution, stirred evenly to form solution A. Then, 2.5g of terephthalic acid was dissolved in 25ml of 1.6M NaOH solution and stirred evenly to form solution B. Solution A was slowly added dropwise to solution B and stirred continuously for 1h. Subsequently, the uniform mixed solution was transferred to a hydrothermal reactor and hydrothermally reacted at 150℃ for 13h. After cooling to room temperature, it was filtered and dried at 60℃ for 12h. After that, it was transferred to a muffle furnace and calcined at 450℃ for 2h (heating rate was 2℃min -1 ), and after cooling to room temperature, it was taken out and ground into powder to obtain Ga-MOF electrode material.

[0046] The XRD pattern of the Ga-MOF electrode material prepared in this example is shown in FIG. Figure 1 shown by Figure 1 It can be seen that the high-intensity diffraction peak in the material indicates a higher degree of crystallinity, and the diffraction peak position is consistent with the results reported in relevant literature, indicating that the material was successfully prepared.

[0047] The TEM image of the Ga-MOF electrode material prepared in this example is as follows Figure 2 shown by Figure 2 It can be seen that the particle size of the material reaches the nanometer level and presents an obvious porous structure.

[0048] The fluorescence emission spectrum of the Ga-MOF electrode material prepared in this example is shown in FIG. Figure 3 shown by Figure 3 It can be seen that the material has an obvious fluorescence characteristic peak in the wavelength range of 300 to 500 nm, proving that the material has certain fluorescence properties.

[0049] The electrochemical performance of the Ga-MOF electrode material prepared in Example 1 was tested as follows:

[0050] First, the prepared Ga-MOF electrode material, conductive agent Ketjen black and binder polyvinylidene fluoride (PVDF) were weighed in a mass ratio of 8:1:1 and put into an agate mortar to grind and mix evenly. An appropriate amount of N-methylpyrrolidone (NMP) was added as a dispersant to completely disperse the mixture. The mixed slurry was coated on a dry copper foil and vacuum dried at 120°C for 12 hours. After the copper foil was naturally cooled to room temperature, it was cut into circular electrode sheets with a diameter of 11 mm using a sheet punch. After weighing the electrode sheets, they were transferred to an argon-filled glove box and assembled into a CR2032 button battery with a metal lithium sheet as the counter electrode. The electrolyte was 1 mol L -1 LiPF6 was dissolved in ethylene carbonate (EC), ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) in a volume ratio of 1:1:1. The separator was a Celgard 2400 polypropylene membrane. The performance of the electrodes was tested using a Land-2001B battery tester. The voltage range was fixed at 0.01 to 3 V, and the long cycle test was performed at 0.5 Ag. -1 The charge and discharge cycles were carried out at a current density of .

[0051] The cycling performance curve of Ga-MOF electrode material is shown in the figure Figure 4 As shown by Figure 4 It can be seen that the Coulomb efficiency of the material during the cycle is above 90%, and gradually approaches 100% as the cycle progresses, showing good cycle reversibility. -1 At a current density of 1000 mAh g, the maximum reversible specific capacity can reach 600 mAh g -1 It still shows good long-term cycle stability after 1500 cycles.

[0052] Example 2

[0053] First, dissolve 3g Ga(NO3)3·xH2O in 50mL L 水 ∶V 乙醇 =2:1 mixed solution, stirred evenly to form solution A. Then, 2.5g of terephthalic acid was dissolved in 25mL of 1.6M NaOH solution and stirred evenly to form solution B. Solution A was slowly added dropwise to solution B and stirred continuously for 1h. Subsequently, the uniform mixed solution was transferred to a hydrothermal reactor and hydrothermally reacted at 150℃ for 13h. After cooling to room temperature, it was filtered and dried at 60℃ for 12h. After that, it was transferred to a muffle furnace and calcined at 500℃ for 2h (heating rate of 2℃min -1 ), and after cooling to room temperature, the mixture was taken out and ground into powder to obtain an electrode material (i.e., the only difference from Example 1 is that the calcination temperature is 500°C).

[0054] The XRD pattern of the electrode material prepared in this example is as follows: Figure 5 As shown by Figure 5 It can be seen that the diffraction peaks shown in the figure are consistent with those of the standard Ga2O3 material (#PDF-20-0426), indicating that the sample has been converted into Ga2O3.

[0055] The electrode material prepared in this embodiment was subjected to the same effect verification as in Example 1. The results showed that the sample -1 The highest reversible specific capacity at the current density is only 100 mAh g -1 The specific capacity is only about 17% of that in Example 1.

[0056] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a Ga-MOF electrode material with fluorescent properties, characterized in that: The following steps are involved: adding the terephthalic acid solution to the gallium salt solution and mixing to obtain a mixed solution; The mixed solution is subjected to a hydrothermal reaction, dried, and then calcined to obtain the Ga-MOF electrode material.

2. The preparation method according to claim 1, characterized in that The solvent of the terephthalic acid solution is an alkaline solution.

3. The preparation method according to claim 2, characterized in that The alkaline solution is 1M to 3M NaOH solution.

4. The preparation method according to claim 1, characterized in that The solvent of the gallium salt solution is a mixture of water and ethanol in a volume ratio of 1:3 to 3:1; the gallium salt in the gallium salt solution is gallium nitrate.

5. The preparation method according to claim 1, characterized in that The mass ratio of the gallium salt in the gallium salt solution to the terephthalic acid in the terephthalic acid solution is 1:5 to 5:

1.

6. The preparation method according to claim 1, characterized in that The temperature of the hydrothermal reaction is 120-180° C., and the time is 8-15 hours.

7. The preparation method according to claim 1, characterized in that The calcination temperature is 300-480° C., and the calcination time is 1-5 hours.

8. The Ga-MOF electrode material prepared according to the preparation method according to any one of claims 1 to 7.

9. A secondary battery, characterized in that: Including positive electrode materials, negative electrode materials, electrolytes and separators; The negative electrode material includes the Ga-MOF electrode material according to claim 8.

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