A preparation method of metal-coordinated benzene ring-rich organic polymer material

Abstract

The present invention relates to a preparation method of a metal-coordinated benzene ring-rich organic polymer material, comprising: (1) stirring a boric acid monomer and an amine monomer at room temperature to obtain a benzene ring-rich organic polymer material; (2) mixing a metal salt solution with the benzene ring-rich organic polymer material, stirring evenly to obtain a dispersion, and then transferring to a microwave reactor for reaction to obtain a metal-coordinated benzene ring-rich organic polymer material. The metal-coordinated benzene ring-rich organic polymer material of the present invention has a small spherical morphology and is evenly distributed, wherein the rich conjugated benzene ring structure improves the cycle performance and structural stability of the organic electrode material, and each benzene ring molecule can reversibly store six lithium ions, thereby greatly improving its energy storage potential.

Description

Technical Field

[0001] The invention belongs to the field of lithium ion battery electrode materials, and particularly relates to a method for preparing a metal coordinated benzene ring-rich organic polymer material. Background Art

[0002] At present, the negative electrode materials commonly used in lithium-ion batteries are mostly focused 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 energy storage devices has far exceeded the theoretical capacity of graphite (372mA·h·g -1 ). Therefore, organic compounds rich in organic functional groups have attracted widespread attention.

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

[0004] However, for the small molecule organic materials that are currently widely studied, due to their small molecular weight, they are very easy to dissolve in the organic electrolyte in the battery system, causing a sharp decay in capacity; synthesizing high-molecular organic polymer materials through polymerization of small molecule monomers can greatly reduce the dissolution of molecules in organic electrolytes, thereby greatly improving the stability of the material during the cycle process. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing a metal-coordinated benzene ring-rich organic polymer material, which overcomes the current situation in the art that small organic molecule materials are extremely easy to dissolve, resulting in poor stability and low capacity, and discovers the six-electron energy storage potential of benzene ring molecules.

[0006] The present invention provides a method for preparing a metal-coordinated benzene ring-rich organic polymer material, comprising the following steps:

[0007] (1) mixing a boric acid monomer and an amine monomer in a molar ratio of 1:2-2:1, then adding dioxane and triethylamine (dioxane as an organic solvent and triethylamine providing an alkaline environment), and stirring at room temperature for 24-72 hours to obtain a benzene ring-rich organic polymer material;

[0008] (2) The metal salt solution and the benzene ring-rich organic polymer material are mixed in a mass ratio of 2:3 to 4:1, stirred evenly at room temperature to obtain a dispersion, and then transferred to a microwave reactor for reaction to obtain a metal-coordinated benzene ring-rich organic polymer material.

[0009] The boric acid monomer in step (1) is one or more of 1,4-phenyldiboronic acid and 4,4'-biphenyldiboronic acid; the amine monomer is one or more of tris(4-aminophenyl)amine and 1,3,5-tris(4-aminophenyl)benzene.

[0010] The ratio of the amount of the boronic acid monomer to dioxane, the metal salt and triethylamine in the step (1) is 0.15-0.45 mmol:4.0-12.0 mL:0.015-0.045 g:0.015-0.045 g.

[0011] The stirred product in step (1) is first washed and then dried at 60-80° C. to obtain a benzene ring-rich organic polymer material.

[0012] The benzene ring-rich organic polymer material contains 4 to 6 benzene rings per two monomer connection units.

[0013] The metal salt in steps (1) and (2) is cobalt nitrate.

[0014] The room temperature in steps (1) and (2) is 25-40°C.

[0015] The solvent of the metal salt solution in step (2) is a mixed solvent of anhydrous ethanol and N,N-dimethylformamide in a volume ratio of 1:1 to 2:1, and the concentration of the metal salt solution is 1.0 to 5.0 mg / mL.

[0016] The reaction temperature in step (2) is 150-180° C., and the reaction time is 0.5-2 h.

[0017] The metal-coordinated benzene ring-rich organic polymer material obtained in step (2) is used in lithium-ion battery electrode materials.

[0018] The benzene ring-rich organic polymer material of the present invention has the characteristics of being rich in the benzene ring π conjugated system, wherein each benzene ring has the energy storage potential of storing six lithium ions, and can realize a lithium ion battery with a stable structure and excellent electrochemical performance. Several synthesized benzene ring-rich organic polymer materials, wherein the benzene ring has a large π conjugated extension system, and each benzene ring molecule can store six lithium ions, thus exhibiting excellent electrochemical performance in lithium ion batteries.

[0019] The present invention uses cobalt ions as metal ions to achieve coordination in a benzene ring-rich organic polymer material, thereby increasing the molecular layer spacing of the benzene ring-rich organic polymer material, thereby better exposing benzene ring molecules with six-electron redox activity to the reaction system, thereby significantly improving the electrochemical performance of lithium-ion batteries.

[0020] Beneficial Effects

[0021] (1) The preparation process of the present invention is simple, has good feasibility, high repeatability, simple equipment, and can achieve mass production.

[0022] (2) The present invention combines the two advantages of benzene ring-rich organic polymer materials and metal ion coordination: the benzene ring-rich organic polymer material has a large structural design space, and has a rich open pore structure and the characteristics of being rich in benzene rings, wherein each benzene ring molecule has the energy storage potential to store six lithium ions, and can realize electrochemically active charge storage; and the metal ions are coordinated between the molecular layers of the benzene ring-rich organic polymer material, so that the interlayer spacing of the benzene ring-rich organic polymer material is increased, thereby better exposing the benzene ring molecules with redox activity to the reaction system, significantly improving the electrochemical performance of lithium-ion batteries.

[0023] (3) The metal-coordinated benzene ring-rich organic polymer material prepared by the present invention is in the shape of small spheres with uniform size and stable structure, and can be directly used for the preparation of electrode materials for lithium-ion batteries.

[0024] (4) The metal-coordinated benzene ring-rich organic polymer material prepared by the present invention is used for the preparation of electrode materials for lithium-ion batteries, wherein the benzene ring molecules exhibit excellent performance of six-electron energy storage, showing great potential in the field of lithium-ion batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the synthesis of benzene ring-rich organic polymer materials from different monomers in Example 1 (a) and Example 2 (b);

[0026] Figure 2 The scanning electron microscope images of the benzene ring-rich organic polymer material (a) and the cobalt-coordinated benzene ring-rich organic polymer material (b) in Example 1;

[0027] Figure 3 The benzene ring-rich organic polymer material (a) and the cobalt-coordinated benzene ring-rich organic polymer material (b) in Example 1 were subjected to 100 mA·g -1 Electrochemical cycling performance diagram at different current densities. DETAILED DESCRIPTION

[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 are not intended 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 fall within the scope limited by the appended claims of the application equally.

[0029] Example 1

[0030] Preparation of benzene ring-rich organic polymer material A: The boric acid monomer used to synthesize the benzene ring-rich organic polymer material is 1,4-phenylenediboronic acid, and the amine monomer is tris(4-aminophenyl)amine; the structural schematic diagram thereof is as follows Figure 1 29.0 mg (0.1 mmol) of tri(4-aminophenyl)amine, 24.9 mg (0.15 mmol) of 1,4-phenylenediboronic acid, 4.0 mL of dioxane, 0.015 g of copper acetate and 0.015 g of triethylamine solution were mixed in a sealed glass bottle, stirred at 25°C for 24 h, the solid was collected in a centrifuge tube, washed with dioxane 3 times, and finally dried at 60°C to obtain the benzene ring-rich organic polymer material used as the negative electrode material of lithium ion batteries, and its scanning electron microscope image is shown as follows Figure 2 a. At 100 mA·g -1 The first cycle charge / discharge capacity at the current density is 239.6 / 668.3 mA·h·g -1 , and the reversible capacity remained at 208.4 mA·h·g after 50 cycles -1 , its electrochemical cycle performance is as follows Figure 3 As shown in a.

[0031] Preparation of cobalt-coordinated benzene ring-rich organic polymer material A: 20 mg of benzene ring-rich organic polymer material was placed in 20 mL of 1.0 mg / mL cobalt acetate solution, stirred at 25°C for 10 minutes, and then transferred to a microwave reaction tank. The microwave reaction temperature was controlled to be 150°C and the reaction time was 0.5 h to obtain the cobalt-coordinated benzene ring-rich organic polymer material used as a negative electrode material for lithium-ion batteries. The scanning electron microscope image is shown as follows Figure 2 b. At 100 mA·g -1 The first cycle charge / discharge capacity can reach 574.3 / 1007.5 mA·h·g at the current density -1 , and the reversible capacity reaches 461.0mA·h·g after 100 cycles -1 , which is much higher than that of benzene-rich organic polymer materials. Its electrochemical cycle performance is as follows Figure 3 As shown in b, it shows that the cobalt-coordinated benzene ring-rich organic polymer material has better electrochemical properties.

[0032] Example 2

[0033] Preparation of benzene ring-rich organic polymer material B: The boric acid monomer used to synthesize the benzene ring-rich organic polymer material is 4,4'-biphenyl diboronic acid, and the amine monomer is 1,3,5-tri(4-aminophenyl)benzene; the structural schematic diagram thereof is as follows Figure 1 b. 105.4 mg (0.3 mmol) of 1,3,5-tri(4-aminophenyl)benzene, 108.8 mg (0.45 mmol) of 4,4'-biphenyl diboronic acid, 12.0 mL of dioxane, 0.045 g of copper acetate and 0.045 g of triethylamine solution were mixed in a sealed glass bottle, stirred at 40°C for 72 h, the solid was collected in a centrifuge tube, washed with dioxane 5 times, and finally dried at 80°C to obtain the benzene ring-rich organic polymer material B. At 100 mA·g -1 The first cycle charge / discharge capacity at the current density is 215.7 / 603.2 mA·h·g -1 , and the reversible capacity remained at 195.4 mA·h·g after 50 cycles -1 .

[0034] Preparation of cobalt-coordinated benzene ring-rich organic polymer material B: 20 ​​mg of benzene ring-rich organic polymer material was placed in 20 mL of 1.0 mg / mL cobalt acetate solution, stirred at 40°C for 30 minutes, and then transferred to a microwave reaction tank, the microwave reaction temperature was controlled to be 180°C, and the reaction time was 2 hours to obtain the cobalt-coordinated benzene ring-rich organic polymer material B. At 100 mA·g -1 The first cycle charge / discharge capacity can reach 535.9 / 975.6 mA·h·g at the current density -1 , and the reversible capacity reaches 431.0mA·h·g after 100 cycles -1 .

[0035] Example 3

[0036] Preparation of benzene ring-rich organic polymer material C: The boric acid monomer used to synthesize the benzene ring-rich organic polymer material is 1,4-phenylenediboronic acid, and the amine monomer is tris(4-aminophenyl)amine; the structural schematic diagram thereof is as follows Figure 1 As shown in a. 29.0 mg (0.2 mmol) of tris (4-aminophenyl) amine, 24.9 mg (0.2 mmol) of 1,4-phenylenediboronic acid, 8.0 mL of dioxane, 0.03 g of copper acetate and 0.03 g of triethylamine solution were mixed in a sealed glass bottle, stirred at 30 ° C for 36 h, and the solid was collected in a centrifuge tube, washed with dioxane for 4 times, and finally dried at 70 ° C to obtain the benzene ring-rich organic polymer material C. At 100 mA·g -1 The first cycle charge / discharge capacity at the current density is 218.5 / 613.6 mA·h·g -1 , and the reversible capacity remained at 206.4 mA·h·g after 50 cycles-1 .

[0037] Preparation of cobalt-coordinated benzene ring-rich organic polymer material C: 20 mg of benzene ring-rich organic polymer material was placed in 20 mL of 2.0 mg / mL cobalt acetate solution, stirred at 30°C for 15 minutes, and then transferred to a microwave reaction tank, the microwave reaction temperature was controlled to be 160°C, and the reaction time was 1 hour to obtain the cobalt-coordinated benzene ring-rich organic polymer material C. At 100 mA·g -1 The first cycle charge / discharge capacity can reach 556.8 / 1015.3mA·h·g at the current density -1 , and the reversible capacity reaches 446.7 mA·h·g after 100 cycles -1 .

[0038] Example 4

[0039] Preparation of benzene ring-rich organic polymer material D: The boric acid monomer used to synthesize the benzene ring-rich organic polymer material is 4,4'-biphenyl diboronic acid, and the amine monomer is 1,3,5-tri(4-aminophenyl)benzene; the structural schematic diagram thereof is as follows Figure 1 b. 105.4 mg (0.2 mmol) of 1,3,5-tri(4-aminophenyl)benzene, 108.8 mg (0.4 mmol) of 4,4'-biphenyl diboric acid, 8.0 mL of dioxane, 0.03 g of copper acetate and 0.03 g of triethylamine solution were mixed in a sealed glass bottle, stirred at 35°C for 48 h, the solid was collected in a centrifuge tube, washed with dioxane 5 times, and finally dried at 70°C to obtain the benzene ring-rich organic polymer material D. At 100 mA·g -1 The first cycle charge / discharge capacity at the current density is 252.8 / 698.7 mA·h·g -1 , and the reversible capacity remained at 206.9 mA·h·g after 50 cycles -1 .

[0040] Preparation of cobalt-coordinated benzene ring-rich organic polymer material D: 20 mg of benzene ring-rich organic polymer material was placed in 20 mL of 4.0 mg / mL cobalt acetate solution, stirred at 35°C for 20 minutes, and then transferred to a microwave reaction tank, the microwave reaction temperature was controlled at 170°C, the reaction time was 2 hours, and the cobalt-coordinated benzene ring-rich organic polymer material D was obtained. At 100 mA·g -1 The first cycle charge / discharge capacity can reach 596.3 / 1080.6 mA·h·g at the current density -1 , and the reversible capacity reaches 458.9 mA·h·g after 100 cycles -1 .

Claims

1. A method for preparing a metal-coordinated benzene ring-rich organic polymer material, comprising the following steps: (1) mixing a boric acid monomer and an amine monomer in a molar ratio of 1:2-2:1, then adding dioxane and triethylamine, and stirring at room temperature for 24-72 hours to obtain a benzene ring-rich organic polymer material; wherein: The boronic acid monomer is one or more of 1,4-phenyldiboronic acid and 4,4'-biphenyldiboronic acid; the amine monomer is one or more of tris(4-aminophenyl)amine and 1,3,5-tris(4-aminophenyl)benzene; (2) The metal salt solution and the benzene ring-rich organic polymer material are mixed in a mass ratio of 2:3 to 4:1, stirred evenly at room temperature to obtain a dispersion, and then transferred to a microwave reactor for reaction to obtain a metal-coordinated benzene ring-rich organic polymer material.

2. The preparation method according to claim 1, characterized in that: The ratio of the amount of the boronic acid monomer to dioxane, the metal salt and triethylamine in the step (1) is 0.15-0.45 mmol:4.0-12.0 mL:0.015-0.045 g:0.015-0.045 g.

3. The preparation method according to claim 1, characterized in that: The stirred product in step (1) is first washed and then dried at 60-80° C. to obtain a benzene ring-rich organic polymer material.

4. The preparation method according to claim 1, characterized in that: The metal salt in step (2) is cobalt nitrate.

5. The preparation method according to claim 1, characterized in that: The room temperature in steps (1) and (2) is 25-40°C.

6. The preparation method according to claim 1, characterized in that: The solvent of the metal salt solution in step (2) is a mixed solvent of anhydrous ethanol and N,N-dimethylformamide in a volume ratio of 1:1 to 2:1, and the concentration of the metal salt solution is 1.0 to 5.0 mg / mL.

7. The preparation method according to claim 1, characterized in that: The reaction temperature in step (2) is 150-180° C., and the reaction time is 0.5-2 h.

8. The preparation method according to claim 1, characterized in that: The metal-coordinated benzene ring-rich organic polymer material obtained in step (2) is used in lithium-ion battery electrode materials.

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