Preparation method of an inorganic-organic composite material based on an organic fluorine polymer

Abstract

The present invention relates to a method for preparing an inorganic-organic composite material based on an organic fluoropolymer, comprising: (1) mixing an amino monomer and an aldehyde monomer, then adding mesitylene and dioxane, and reacting in an oven to obtain a benzene ring-rich organic fluoropolymer material; wherein the aldehyde monomer is 2,3,5,6-tetrafluoroterephthalaldehyde; (2) mixing an aqueous potassium permanganate solution with the benzene ring-rich organic fluoropolymer material, stirring evenly to obtain a dispersion liquid, and then transferring it to an oil bath for a reduction reaction to obtain an inorganic-organic composite material based on an organic fluoropolymer. As an electrode material for lithium-ion batteries, the inorganic-organic composite material based on an organic fluoropolymer in the present invention has excellent electrochemical performance and can be further modified and assembled, having good application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of lithium-ion battery electrode materials, and particularly relates to a preparation method of an inorganic-organic composite material based on an organic fluoropolymer. Background Art

[0002] Currently, most of the anode materials commonly used in lithium-ion batteries focus on graphite. However, with the widespread application of lithium-ion batteries in energy storage devices such as mobile phones and new energy vehicles, the energy required by the energy storage devices has far exceeded the theoretical capacity of graphite (372 mA·h·g -1 ). Therefore, organic compounds rich in a large number of organic functional groups have attracted extensive attention.

[0003] Firstly, organic compounds contain a large number of functional groups, such as carbonyl (C=O), imino (C=N), and phenyl, etc., which can undergo reversible redox reactions with lithium ions, thereby providing excellent reversible capacity; secondly, organic compounds are mainly formed by covalent bonding of light elements such as C, N, and O. Compared with pure inorganic oxides or transition metal salts, they are very friendly to the environment and belong to green materials. Therefore, organic materials have been proven to be very promising electrode candidate materials.

[0004] However, for the small molecule organic materials widely studied currently, due to their small molecular weight, they are very easy to dissolve in the organic electrolyte in the battery system, resulting in a sharp decline in capacity; while for macromolecular organic polymers, due to the stacking of molecular structures during the synthesis process, the organic functional groups cannot be well exposed in the reaction system, resulting in a very small reversible capacity of pure organic polymers. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a preparation method of an inorganic-organic composite material based on an organic fluoropolymer, which overcomes the current situation that organic small molecule materials are extremely easy to dissolve and polymer materials are easy to stack in the prior art, and discovers the energy storage potential of the six electrons of the benzene ring molecule.

[0006] The present invention provides a preparation method of an inorganic-organic composite material based on an organic fluoropolymer, comprising the following steps:

[0007] (1) Mix an amine-based monomer and an aldehyde-based monomer in a molar ratio of 1:2 - 2:1, then add mesitylene and dioxane, and place them in an oven at 120 - 150 °C for reaction for 24 - 72 h to obtain a benzene ring-rich organic fluoropolymer material; wherein, the aldehyde-based monomer is 2,3,5,6-tetrafluoroterephthalaldehyde;

[0008] (2) Mix an aqueous potassium permanganate solution and an organic fluorine polymer material rich in benzene rings at a mass ratio of 3:1 - 1:1, stir evenly to obtain a dispersion liquid, and then transfer it to an oil bath for a reduction reaction to obtain an inorganic-organic composite material based on the organic fluorine polymer.

[0009] The amino monomer in the step (1) is one or more of 1,3,5-tris(4-aminophenyl)benzene and tris(4-aminophenyl)amine.

[0010] The dosage ratio of the amino monomer, mesitylene and dioxane in the step (1) is 0.1 - 0.3 mmol: 2.5 - 7.5 mL: 2.5 - 7.5 mL.

[0011] The reaction product in the step (1) is first washed, then subjected to Soxhlet extraction and dried at 60 - 80 °C to obtain an organic fluorine polymer material rich in benzene rings.

[0012] The solvent selected for the Soxhlet extraction is tetrahydrofuran, the Soxhlet extraction temperature is 80 - 100 °C, and the Soxhlet extraction time is 24 - 48 h.

[0013] The number of benzene rings in the organic fluorine polymer material rich in benzene rings is 4 - 5 benzene rings per two monomer linking units.

[0014] The concentration of the aqueous potassium permanganate solution in the step (2) is 0.1 - 1.0 mg / mL.

[0015] The reduction reaction temperature in the step (2) is 25 - 45 °C, and the reaction time is 0.5 - 6 h.

[0016] The application of the inorganic-organic composite material based on the organic fluorine polymer obtained in the step (2) in a lithium-ion battery electrode material.

[0017] The organic fluorine polymer material rich in benzene rings in the present invention is a class of organic compounds rich in benzene ring π-conjugated systems. During the charge and discharge process, the benzene ring groups therein can realize the energy storage potential of six lithium ions, thereby obtaining a highly stable material and realizing a high-capacity lithium-ion battery. Several synthesized organic fluorine polymer materials rich in benzene rings, in which the benzene rings have a large π-conjugated extended system and can realize the energy storage potential of six lithium ions, show excellent electrochemical performance in lithium-ion batteries.

[0018] The present invention utilizes the in-situ reduction of potassium permanganate solution in the stacking gaps of benzene-ring-rich organic fluoropolymer materials to generate granular manganese dioxide, thereby realizing the dispersion of the stacked polymer. This enables the redox-active functional groups in the benzene-ring-rich organic fluoropolymer materials to be better exposed in the electrolyte reaction system, thus better promoting the participation of benzene-ring molecules with six-electron redox characteristics in the energy storage reaction and significantly enhancing the electrochemical performance of lithium-ion batteries.

[0019] Beneficial effects

[0020] (1) The preparation process of the present invention is simple, feasible, and the equipment is simple, enabling batch production.

[0021] (2) The present invention combines the advantages of two materials: benzene-ring-rich organic fluoropolymer materials and inorganic manganese dioxide metal oxides. Benzene-ring-rich organic fluoropolymer materials have a large structural design space, rich open pore structures, and electrochemical activity, and the benzene-ring molecules contained therein have the potential to store six lithium ions. The manganese dioxide particles obtained by in-situ reduction of liquid-phase potassium permanganate can greatly increase the gaps between the particles of benzene-ring-rich organic fluoropolymer materials, enabling the redox-active benzene-ring molecules to be better exposed in the reaction system and participating in the redox reaction themselves.

[0022] (3) The inorganic-organic composite material based on organic fluoropolymer prepared by the present invention presents a spherical shape, has uniform size and stable structure, and can be directly used for the preparation of electrode materials for lithium-ion batteries.

[0023] (4) The inorganic-organic composite material based on organic fluoropolymer prepared by the present invention is used for the preparation of electrode materials for lithium-ion batteries. Among them, the benzene-ring molecules exhibit excellent six-electron energy storage performance, show excellent electrochemical performance, and demonstrate great application potential in the field of lithium-ion batteries. Description of the Drawings

[0024] Figure 1 Synthesis schematic diagrams of benzene-ring-rich organic fluoropolymer materials synthesized from different monomers in Example 1 (a) and Example 2 (b);

[0025] Figure 2 Scanning electron microscope image of the benzene-ring-rich organic fluoropolymer material in Example 2;

[0026] Figure 3 Scanning electron microscope image of the inorganic-organic composite material based on organic fluoropolymer in Example 2;

[0027] Figure 4 For the benzene-ring-rich organic fluoropolymer material and the inorganic-organic composite material based on organic fluoropolymer in Example 2 at 100 mA·g-1 Electrochemical cycling performance graph at current density. Detailed implementation manners

[0028] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0029] Example 1

[0030] Preparation of benzene-ring-rich organofluorine polymer material A: The amine monomer selected for synthesizing the benzene-ring-rich organofluorine polymer is 1,3,5-tris(4-aminophenyl)benzene, and the aldehyde monomer is 2,3,5,6-tetrafluoroterephthalaldehyde. Its structural schematic diagram is as shown in Figure 1 a. Put 35.1 mg (0.1 mmol) of 1,3,5-tris(4-aminophenyl)benzene, 30.9 mg (0.15 mmol) of 2,3,5,6-tetrafluoroterephthalaldehyde, and 5 mL of a mixed solvent of dioxane (containing 2.5 mL) / mesitylene (containing 2.5 mL) into a pressure-resistant glass tube, ultrasonically treat for 5 min, perform a gas replacement operation on the system in an argon / nitrogen atmosphere, place it in an oven at 120 °C for 72 h, collect the solid into a centrifuge tube, wash it 3 times with dioxane, dichloromethane, and tetrahydrofuran respectively, then perform Soxhlet extraction with tetrahydrofuran at 80 °C for 24 h and dry at 60 °C to obtain the benzene-ring-rich organofluorine polymer material A. At a current density of 100 mA·g -1 The initial charge / discharge capacity at this current density is 103.7 / 646.2 mA·h·g -1 , and the reversible capacity remains at 97.9 mA·h·g after 50 cycles -1 .

[0031] Preparation of inorganic-organic composite material A based on organofluorine polymer: Put 20 mg of benzene-ring-rich organofluorine polymer material A into 40 mL of an aqueous potassium permanganate solution with a concentration of 0.1 mg / mL, control the reduction temperature at 25 °C, the reduction time at 6 h, and continue ultrasonic treatment for 2 h to obtain the inorganic-organic composite material A based on organofluorine polymer. At a current density of 100 mA·g -1 The initial charge / discharge capacity at this current density is 485.8 / 1587.4 mA·h·g -1 , and the reversible capacity reaches 492.3 mA·h·g after 50 cycles -1 .

[0032] Example 2

[0033] Preparation of benzene-ring-rich organic fluoropolymer material B: The amine monomer selected for synthesizing benzene-ring-rich organic fluoropolymer material B is tris(4-aminophenyl)amine, and the aldehyde monomer is 2,3,5,6-tetrafluoroterephthalaldehyde. Its structural schematic diagram is as shown in Figure 1 Figure b. 87.1 mg (0.3 mmol) of tris(4-aminophenyl)amine, 92.7 mg (0.45 mmol) of 2,3,5,6-tetrafluoroterephthalaldehyde, and 15 mL of a mixed solvent of dioxane (containing 7.5 mL) / mesitylene (containing 7.5 mL) were placed in a pressure-resistant glass tube, ultrasonically treated for 10 min, the system was purged in an argon / nitrogen atmosphere, placed in an oven at 150 °C for 24 h, the solid was collected in a centrifuge tube, washed 5 times with dioxane, dichloromethane, and tetrahydrofuran respectively, and then Soxhlet extracted with tetrahydrofuran at 100 °C for 48 h and dried at 80 °C to obtain an organic polymer. The obtained benzene-ring-rich organic fluoropolymer material B is used as the anode material of a lithium-ion battery. Its scanning electron micrograph is as shown in Figure 2 Figure. At a current density of 100 mA·g -1 , its initial charge / discharge capacity in the first cycle is 95.2 / 297.7 mA·h·g -1 , and the reversible capacity remains at 102.2 mA·h·g -1 after 50 cycles. Its electrochemical cycling performance is as shown in Figure 4 Figure.

[0034] Preparation of inorganic-organic composite material B based on organic fluoropolymer: 20 mg of benzene-ring-rich organic fluoropolymer material B was placed in 40 mL of an aqueous potassium permanganate solution with a concentration of 1.0 mg / mL, the reduction temperature was controlled at 45 °C, the reduction time was 0.5 h, and ultrasonic treatment was continued for 2 h to obtain the inorganic-organic composite material B based on organic fluoropolymer. The obtained inorganic-organic composite material B based on organic fluoropolymer is used as the anode material of a lithium-ion battery. Its scanning electron micrograph is as shown in Figure 3 Figure. At a current density of 100 mA·g -1 , its initial charge / discharge capacity in the first cycle is 547.7 / 1815.1 mA·h·g -1 , and the reversible capacity reaches 560.3 mA·h·g -1 after 50 cycles. Its electrochemical cycling performance is as shown in Figure 4 Figure, indicating that the inorganic-organic composite material based on organic fluoropolymer has more excellent electrochemical performance.

[0035] Example 3

[0036] Preparation of benzene-rich organic fluoropolymer material C: The amino monomer selected for synthesizing the benzene-rich organic fluoropolymer is 1,3,5-tris(4-aminophenyl)benzene, and the aldehyde monomer is 2,3,5,6-tetrafluoroterephthalaldehyde. 35.1 mg (0.2 mmol) of 1,3,5-tris(4-aminophenyl)benzene, 30.9 mg (0.2 mmol) of 2,3,5,6-tetrafluoroterephthalaldehyde, and 10 mL of a mixed solvent of dioxane (containing 5.0 mL) / mesitylene (containing 5.0 mL) are placed in a pressure-resistant glass tube, ultrasonically treated for 7 min, the system is purged in an argon / nitrogen atmosphere, placed in an oven at 130 °C for 36 h, the solid is collected in a centrifuge tube, washed 4 times with dioxane, dichloromethane, and tetrahydrofuran respectively, then subjected to Soxhlet extraction with tetrahydrofuran at 90 °C for 36 h and dried at 70 °C to obtain the benzene-rich organic fluoropolymer material C. At a current density of 100 mA·g -1 the initial charge / discharge capacity is 111.6 / 654.9 mA·h·g -1 and the reversible capacity remains 100.5 mA·h·g after 50 cycles -1 .

[0037] Preparation of inorganic-organic composite material C based on organic fluoropolymer: 20 mg of the benzene-rich organic fluoropolymer material C is placed in 40 mL of an aqueous potassium permanganate solution with a concentration of 0.5 mg / mL, the reduction temperature is controlled at 35 °C, the reduction time is 3 h, and ultrasonic treatment is continued for 2 h to obtain the inorganic-organic composite material C based on the organic fluoropolymer. At a current density of 100 mA·g -1 the initial charge / discharge capacity is 488.1 / 1613.2 mA·h·g -1 and the reversible capacity reaches 498.2 mA·h·g after 50 cycles -1 .

[0038] Example 4

[0039] Preparation of benzene-rich organic fluoropolymer material D: The amine monomer selected for synthesizing benzene-rich organic fluoropolymer material D is tris(4-aminophenyl)amine, and the aldehyde monomer is 2,3,5,6-tetrafluoroterephthalaldehyde. 87.1 mg (0.2 mmol) of tris(4-aminophenyl)amine, 92.7 mg (0.4 mmol) of 2,3,5,6-tetrafluoroterephthalaldehyde, and 10 mL of a mixed solvent of dioxane (containing 5.0 mL) / mesitylene (containing 5.0 mL) were placed in a pressure-resistant glass tube, ultrasonically treated for 10 min, the system was purged in an argon / nitrogen atmosphere, placed in an oven at 120 °C for 48 h, the solid was collected in a centrifuge tube, washed 5 times with dioxane, dichloromethane, and tetrahydrofuran respectively, then subjected to Soxhlet extraction with tetrahydrofuran at 90 °C for 36 h and dried at 60 °C to obtain organic fluoropolymer material D. The benzene-rich organic fluoropolymer material D was obtained. At a current density of 100 mA·g -1 The initial charge / discharge capacity is 110.8 / 660.0 mA·h·g -1 and the reversible capacity remains 105.1 mA·h·g after 50 cycles -1 .

[0040] Preparation of inorganic-organic composite material D based on organic fluoropolymer: 20 mg of benzene-rich organic fluoropolymer material D was placed in 40 mL of an aqueous potassium permanganate solution with a concentration of 0.8 mg / mL, the reduction temperature was controlled at 40 °C, the reduction time was 2 h, and ultrasonic treatment was continued for 2 h to obtain the inorganic-organic composite material D based on organic fluoropolymer. The inorganic-organic composite material D based on organic fluoropolymer was obtained. At a current density of 100 mA·g -1 The initial charge / discharge capacity is 501.1 / 1605.8 mA·h·g -1 and the reversible capacity reaches 500.7 mA·h·g after 50 cycles -1 . It shows that the inorganic-organic composite material based on organic fluoropolymer has more excellent electrochemical performance.

Claims

1. A method for preparing an inorganic-organic composite material based on an organic fluoropolymer, comprising the following steps: (1) Mix the amine-based monomer and the aldehyde-based monomer in a molar ratio of 1:2 - 2:1, then add mesitylene and dioxane, and place them in an oven at 120 - 150 °C for reaction for 24 - 72 h to obtain a benzene ring-rich organic fluorine polymer material; among them, The amino monomer is one or more of 1,3,5-tris(4-aminophenyl)benzene and tris(4-aminophenyl)amine; the aldehyde monomer is 2,3,5,6-tetrafluoroterephthalaldehyde; (2) Mix an aqueous potassium permanganate solution and an aromatic-ring-rich organic fluoropolymer material in a mass ratio of 3:1 - 1:1, stir evenly to obtain a dispersion, and then transfer it to an oil bath for a reduction reaction to obtain an inorganic-organic composite material based on the organic fluoropolymer; in step (2), in-situ reduction is carried out in the stacking gaps of the aromatic-ring-rich organic fluoropolymer material to generate granular manganese dioxide to achieve the dispersion of the stacked polymer.

2. The preparation method according to claim 1, characterized in that: The dosage ratio of the amino monomer, mesitylene and dioxane in step (1) is 0.1 - 0.3 mmol: 2.5 - 7.5 mL: 2.5 - 7.5 mL.

3. The preparation method according to claim 1, characterized in that: The reaction product in step (1) is first washed, then subjected to Soxhlet extraction and dried at 60 - 80 °C to obtain an aromatic-ring-rich organic fluoropolymer material.

4. The preparation method according to claim 3, characterized in that: The solvent used for Soxhlet extraction is tetrahydrofuran, the Soxhlet extraction temperature is 80 - 100 °C, and the Soxhlet extraction time is 24 - 48 h.

5. The preparation method according to claim 1, characterized in that: The concentration of the aqueous potassium permanganate solution in step (2) is 0.1 - 1.0 mg / mL.

6. The preparation method according to claim 1, characterized in that: The reduction reaction temperature in step (2) is 25 - 45 °C, and the reaction time is 0.5 - 6 h.

7. Use of an inorganic-organic composite material based on an organic fluorine polymer obtained by the preparation method according to claim 1, characterized in that: Applied to the electrode material of a lithium-ion battery.

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