Stable triazole-based metal organic framework material, preparation method thereof and solid-state battery

Abstract

The invention discloses a stable triazole-based metal organic framework material, a preparation method thereof and a solid-state battery. According to the preparation method, 1, 3, 5-trimethylbenzene and 4-bromo-1, 2-diaminobenzene are used as raw materials to synthesize a tri-connection triazole-based ligand H3TTBT under specific and appropriate conditions, and then the tri-connection triazole-based ligand H3TTBT and Cu metal are prepared under specific and appropriate conditions to obtain the stable triazole-based metal organic framework material. The material is novel in structure, excellent in property and relatively high in stability, and has excellent lithium ion and sodium ion conduction performance. In addition, the synthesis and preparation method disclosed by the invention is simple to operate, relatively low in cost and suitable for the solid electrolyte of a high-safety lithium metal battery and a sodium metal battery.

Description

Technical Field

[0001] The present invention belongs to the field of metal-organic framework materials, and relates to a metal-organic framework material, specifically to a stable triazole-based metal-organic framework material, a preparation method thereof, and a solid-state battery. Background Art

[0002] Lithium metal batteries with high theoretical energy density can meet the requirements of next-generation electronic devices and electric vehicles for long battery life, showing great application potential. However, lithium metal batteries based on flammable organic electrolytes have safety problems, including lithium dendrite growth and unstable electrolyte interface layers, which limit their performance and large-scale application. Using solid-state electrolytes instead of organic electrolytes is an effective strategy to achieve lithium metal batteries with both high energy density and high safety. Inorganic solid-state electrolytes have high ionic conductivity, but insufficient stability towards air components and lithium metal anodes limits the performance of solid-state batteries. Polymer solid-state electrolytes exhibit excellent interfacial compatibility and high stability, but low ionic conductivity and ion transfer number limit their performance. In addition, solid-state sodium metal batteries show great potential in large-scale energy storage systems due to their low cost, safety, and high energy density. Therefore, the development of high-performance lithium-ion and sodium-ion solid-state electrolytes with high ionic conductivity and good stability is beneficial to the large-scale application of lithium metal batteries and sodium metal batteries.

[0003] Metal-organic frameworks (MOFs) are assembled from metal-containing nodes and organic ligands, and are crystalline porous materials with high porosity, designability, and well-defined pore structures. These inherent characteristics endow them with tunable ion transport channels, making them one of the promising solid-state electrolyte materials. In particular, anion MOFs with charge-balanced cations can be used as single-ion conductors, which can significantly increase the + or + transfer number of Li -5 S cm -1 For example, MIT-20, a benzotriazole-based anion MOF synthesized based on the hard-soft acid-base principle, shows 4.4×10 -5 S cm -1 and 8.8×10 -7 Scm -1 of Li + or + Na 2+ and Mg Summary of the Invention

[0004] The present invention provides a stable triazole-based metal-organic framework material, a preparation method thereof, and applications in solid electrolytes of lithium metal batteries and sodium metal batteries. This metal-organic framework material has a novel structure, excellent properties, high stability, and lithium ion and sodium ion conduction performance.

[0005] The specific technical solutions are as follows:

[0006] A stable triazole-based metal-organic framework material, Cu-TTBT-MOF, is formed by coordinating and connecting an organic ligand (H3TTBT) with Cu.

[0007] The organic ligand has the following chemical structure:

[0008]

[0009] The preparation method of the organic ligand includes the following:

[0010] (1) 4-Bromo-1,2-diaminobenzene, di-tert-butyl dicarbonate, and ethanol are added and stirred at room temperature for at least 24 hours. The precipitate is collected by filtration and dried in an oven to obtain a solid, namely Compound 1:

[0011]

[0012] (2) Under anhydrous and anaerobic conditions, Compound 1, bis(pinacolato)diboron, KOAc, and Pd(dppf)Cl2 are added to dioxane, and heated at 100 °C for 12 hours under nitrogen. The mixture is extracted with chloroform and washed with brine. The combined organic extracts are dried over anhydrous MgSO4, filtered, and the organic solvents are rotary evaporated. The crude product is purified by column chromatography to obtain a solid, namely Compound 2:

[0013]

[0014] (3) 1,3,5-Trimethylbenzene, iodine, periodic acid, acetic acid, and water are stirred and mixed, and then concentrated sulfuric acid is added dropwise. The resulting mixture is heated under reflux at 90 °C for 10 hours, filtered under vacuum, and washed with distilled water and acetone respectively to obtain a solid, namely Compound 3:

[0015]

[0016] (4) Compound 3, Compound 2, Pd(dppf)Cl2, KOAc, 1,4-dioxane, and H2O are added to a reaction vessel, a condenser is connected, and the mixture is degassed by bubbling nitrogen. The reaction is stirred at 105 °C for three days. After cooling to room temperature, the solvent is removed under reduced pressure. The crude solid is purified by column chromatography to obtain a white solid, namely Compound 4:

[0017]

[0018] (5) Dissolve Compound 4 in a tetrahydrofuran solution. Add concentrated hydrochloric acid solution, and stir the mixture overnight at room temperature. Filter to obtain a solid, which is Compound 5.

[0019]

[0020] (6) Add Compound 5, acetic acid and water into a reaction vessel. Cool the mixture in an ice / water bath, slowly add an aqueous solution of sodium nitrite while maintaining the temperature below 10 °C, then stir at room temperature overnight, and dilute the mixture with water. Filter the precipitate to obtain the organic ligand.

[0021]

[0022] In step (1), the mass ratio of 4-bromo-1,2-diaminobenzene to di-tert-butyl dicarbonate is usually 1:3.

[0023] In step (2), the molar ratio of Compound 1 to bis(pinacolato)diboron can be 1:1.5;

[0024] In step (2), Pd(dppf)Cl2 is usually added at 5 mol% of Compound 1;

[0025] In step (2), the eluent used for column chromatography is ethyl acetate and petroleum ether, and the volume ratio of the two is 1:4.

[0026] In step (3), the molar ratio of 1,3,5-trimethylbenzene, iodine and periodic acid is usually 1:3:0.6;

[0027] In step (3), the volume ratio of the solvent acetic acid to water is 5:1;

[0028] In step (3), the amount of sulfuric acid used is 3 ml.

[0029] In step (4), the molar ratio of Compound 3 to Compound 2 is 1:4;

[0030] In step (4), Pd(dppf)Cl2 is usually added at 5 mol% of Compound 3;

[0031] In step (4), the volume ratio of the solvent dioxane to water is 10:1;

[0032] In step (4), the eluent used for column chromatography is ethyl acetate and petroleum ether, and the volume ratio of the two is 1:4.

[0033] In step (6), the molar ratio of Compound 5 to sodium nitrite is usually 1:1.5;

[0034] In step (6), the concentration of the sodium nitrite aqueous solution is 1 M;

[0035] In step (6), the volume ratio of the solvent acetic acid to water is 7:1.

[0036] The method for preparing the stable triazole-based metal-organic framework material as described above includes the steps:

[0037] Adding the organic ligand and copper dichloride dihydrate into a mixed solution of N,N-dimethylformamide (DMF) and trifluoroacetic acid for solvothermal reaction to obtain the stable triazole-based metal-organic framework material Cu-TTBT-MOF.

[0038] In the above technical solution, further, the mass ratio of the copper dichloride dihydrate to the organic ligand is not less than 2:1;

[0039] In the mixed solution of N,N-dimethylformamide and trifluoroacetic acid, the volume ratio of N,N-dimethylformamide to trifluoroacetic acid is 1:1;

[0040] The dosage ratio of the organic ligand to N,N-dimethylformamide is 5 mg:2 mL;

[0041] Further, the temperature of the solvothermal reaction is 120 - 180 °C, and the time is 24 - 48 h;

[0042] Further, after the solvothermal reaction, the following post-treatment operations are also carried out: taking the solid product, washing and soaking it with N,N-dimethylformamide, and drying to obtain the metal-organic framework material;

[0043] The present invention also provides the application of the metal-organic framework material Cu-TTBT-MOF in a solid electrolyte; the present invention first designs and synthesizes a novel three-connected triazole ligand, and then synthesizes a highly stable metal-organic framework material Cu-TTBT-MOF under specific and suitable conditions. After activation, lithium ions or sodium ions are exchanged in a THF solution to obtain the solid electrolyte Cu-TTBT-Li or Cu-TTBT-Na, which can be applied in lithium metal batteries or sodium metal batteries, and the solid battery performance is excellent. Specifically, according to some embodiments of the present invention, a certain amount of Cu-TTBT-MOF is placed in a vacuum drying oven at 120 °C for activation, added to a LiCl / tetrahydrofuran (THF) solution and stirred for 24 h. Centrifuged and washed with THF, and dried to obtain the metal-organic framework material Cu-TTBT-Li;

[0044] Or, the activated Cu-TTBT-MOF is added to a NaSCN / THF solution and stirred for 24 h. Centrifuged and washed with THF, and dried to obtain the metal-organic framework material Cu-TTBT-Na.

[0045] Furthermore, the amount of Cu-TTBT-MOF is 50 mg;

[0046] Furthermore, the concentration of the LiCl / THF solution is 0.1 - 0.5 M, and the amount is 20 mL;

[0047] Furthermore, the concentration of the NaSCN / THF solution is 2 - 5 mg / mL, and the amount is 20 mL.

[0048] The preparation method provided by the present invention synthesizes the tritopic triazole ligand H3TTBT under specific and suitable conditions, and then prepares a stable metal-organic framework material with Cu metal under specific and suitable conditions. Through the ion exchange of lithium ions or sodium ions, the solid electrolyte Cu-TTBT-Li or Cu-TTBT-Na is obtained. The synthesis and preparation method of the present invention is simple to operate and has a low cost.

[0049] The metal-organic framework material of the present invention has excellent lithium-ion and sodium-ion conduction properties, enabling long-life lithium-metal batteries and sodium-metal batteries.

[0050] After ion exchange, the lithium-ion conductivity and sodium-ion conductivity of the metal-organic framework material Cu-TTBT-MOF at room temperature are 1.83×10 -4 S cm -1 and 1.1×10 -4 S cm -1 , demonstrating its potential in practical applications.

[0051] The present invention also provides a solid-state battery, which is a solid-state lithium-metal battery or a solid-state sodium-metal battery. The solid-state lithium-metal battery or solid-state sodium-metal battery is loaded with the activated and ion-exchanged metal-organic framework material Cu-TTBT-MOF as a solid electrolyte.

[0052] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0053] 1. The present invention creatively synthesizes a novel-structured tritopic triazole organic ligand H3TTBT.

[0054] 2. The preparation method of the tritopic triazole organic ligand provided by the present invention is simple to operate, has a high yield, and a low cost.

[0055] 3. The preparation method of the metal-organic framework material provided by the present invention is simple and suitable for large-scale synthesis.

[0056] 4. The metal-organic framework material provided by the present invention has high lithium-ion conductivity and sodium-ion conductivity, and has high practical application value.

[0057] 5. The metal-organic framework material provided by the present invention has a stable structure and crystal form after long-term storage, which is convenient for long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a schematic diagram of the metal-organic framework material Cu-TTBT formed by the coordination connection of the organic ligand of the present invention and Cu metal. The yellow atoms represent copper ions, the gray atoms represent carbon atoms, and the blue atoms represent nitrogen atoms.

[0059] Figure 2 It is the powder X-ray diffraction (PXRD) pattern of the metal-organic framework material in Example 2.

[0060] Figure 3 It is the nitrogen adsorption-desorption curve and pore size distribution diagram of the metal-organic framework material in Example 2.

[0061] Figure 4 It is the scanning electron microscope image of the metal-organic framework material in Example 2.

[0062] Figure 5 It is the PXRD pattern of the metal-organic framework material in Example 2 at different temperatures.

[0063] Figure 6 It is the PXRD pattern of the metal-organic framework material in Example 2 in different pH solutions.

[0064] Figure 7 It is the lithium ion and sodium ion conduction performance diagram of the materials obtained in Example 3 and Example 4.

[0065] Figure 8 It is the battery cycle life diagram of the materials obtained in Example 3 and Example 4 as solid electrolytes for lithium metal batteries and sodium metal batteries.

[0066] Figure 9 It is the battery rate diagram of the materials obtained in Example 3 and Example 4 as solid electrolytes for lithium metal batteries and sodium metal batteries. DETAILED DESCRIPTION OF THE INVENTION

[0067] The present invention will be further described below in conjunction with the accompanying drawings and 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.

[0068] The organic ligand used in the present invention is H3TTBT, which is a tritopic triazole ligand H3TTBT synthesized from 1,3,5-trimethylbenzene and 4-bromo-1,2-diaminobenzene as raw materials under specific and appropriate conditions. The stable triazole-based metal-organic framework material can be prepared by using this organic ligand and Cu metal under specific and appropriate conditions, and can be applied to solid electrolytes, having excellent ion conduction ability.

[0069] Example 1

[0070] Synthesis method of organic ligand H3TTBT:

[0071]

[0072] (1) Add 4-bromo-1,2-diaminobenzene (50 g, 0.27 mol), di-tert-butyl dicarbonate (150 g, 0.69 mol) and ethanol (500 mL) to a 1000 mL round-bottom flask equipped with magnetic stirring. Stir at room temperature for 24 hours. Collect the precipitate by filtration and dry it in an oven to obtain Compound 1

[0073] (2) Under anhydrous and anaerobic conditions, add Compound 1 (3.87 g, 10 mmol), bis(pinacolato)diboron (3.8 g, 1.5 mmol), KOAc (3 g, 30 mmol), Pd(dppf)Cl2 (365 mg, 0.5 mmol) to dioxane (150 mL). Heat the reaction mixture at 100 °C under nitrogen for 12 hours. Extract the mixture with chloroform and wash with brine. Dry the combined organic extracts with anhydrous MgSO4, filter and rotary evaporate the organic solvent. Purify the crude product by flash column using ethyl acetate / petroleum ether (1:4) as the eluent to obtain Compound 2:

[0074] (3) Load 1,3,5-trimethylbenzene (12.0 g, 0.1 mol), iodine (38.8 g, 0.305 mol), periodic acid (14.0 g, 0.0614 mol), acetic acid (100 mL) and water (20 mL) into a 250 mL round-bottom flask. After stirring the mixture, add 3 mL of concentrated sulfuric acid dropwise. Heat the mixture under reflux at 90 °C for 10 hours, filter by vacuum, and wash with distilled water and acetone respectively to obtain Compound 3:

[0075] (4) Add Compound 3 (4.98 g, 10 mmol), Compound 2 (17.3 g, 40 mmol), Pd(dppf)Cl2 (365 mg, 0.5 mmol), KOAc (6 g, 60 mmol), 1,4-dioxane (200 mL) and H2O (20 mL) to a 500 mL round-bottom flask. Connect a condenser to the flask and degas the mixture by bubbling nitrogen for 30 minutes. Stir the reaction at 100 °C for three days. After cooling to room temperature, remove the solvent under reduced pressure. Purify the crude solid by column chromatography using ethyl acetate / petroleum ether (1:4) as the eluent to obtain a white solid, i.e., Compound 4:

[0076] (5) Dissolve compound 4 (10 g, 10 mmol) in tetrahydrofuran solution (30 mL). Add concentrated hydrochloric acid solution (15 mL), and stir the mixture overnight at room temperature. Filter to obtain compound 5.

[0077] (6) Add compound 5 (4.71 g, 3.45 mmol), acetic acid (70 mL) and water (10 mL) to a 250 mL round-bottom flask equipped with a magnetic stir bar. Cool the mixture in an ice / water bath, and slowly add an aqueous sodium nitrite solution (0.36 g, 5.2 mmol) while maintaining the temperature below -10 °C. Stir the mixture at room temperature overnight, and dilute the mixture with water. Filter the precipitate to obtain the organic ligand.

[0078] Example 2

[0079] Synthesis method of metal-organic framework materials (MOFs):

[0080] Dissolve copper(II) chloride dihydrate (10 mg) and the organic ligand (5 mg) in 2 mL of DMF and 2 mL of trifluoroacetic acid, and place them in a 15 mL vial. Then, sonicate the mixture for 3 minutes. Seal the resulting mixture and heat it to 150 °C and hold for 12 hours. Golden block-shaped crystals are obtained. Harvest the crystals and wash them 6 times with DMF within three days. Then wash the crystals 6 times with methanol (MeOH) within three days. Dry the crystals after washing with MeOH to obtain the metal-organic framework material Cu-TTBT-MOF.

[0081] Example 3

[0082] Heat the metal-organic framework material Cu-TTBT-MOF obtained in Example 2 under vacuum at 120 °C for 6 h, stir and exchange it with 0.1 M LiCl / THF solution for 24 hours, centrifuge, wash it with a large amount of tetrahydrofuran solution, and dry to obtain Cu-TTBT-Li for lithium ion conduction performance testing.

[0083] Example 4

[0084] Heat the metal-organic framework material Cu-TTBT-MOF obtained in Example 2 under vacuum at 120 °C for 6 h, stir and exchange it with 5 mg / mL NaSCN / THF solution for 24 h, centrifuge, wash it with a large amount of tetrahydrofuran solution, and dry to obtain Cu-TTBT-Na for sodium ion conduction performance testing.

[0085] The metal-organic framework material Cu-TTBT-MOF prepared in Example 1, its structural schematic diagram is as Figure 1 shown, Figure 2 is the PXRD pattern of Cu-TTBT-MOF, and it can be seen that it has high crystallinity. Figure 3Nitrogen adsorption curve and pore size distribution diagram of Cu-TTBT-MOF Figure 4 SEM photograph of Cu-TTBT-MOF, it can be seen that it has a regular shape Figure 5 and Figure 6 PXRD patterns of Cu-TTBT-MOF under different environments, it can be seen that it has excellent thermal stability and pH stability. As Figure 7 、 8 shown in 9, the materials prepared by the present invention have relatively high lithium ion conductivity and sodium ion conductivity, and can be used as solid electrolytes in lithium metal batteries or sodium metal batteries

[0086] In addition, it should be understood that after reading the above description of 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

Claims

1. A stable triazole-based metal organic framework material, characterized in that: It is Cu-TTBT-MOF, which is formed by the coordination connection between the organic ligand H3TTBT and Cu; The organic ligand H3TTBT has the following chemical structure:

2. The method for preparing a stable triazole-based metal organic framework material according to claim 1, characterized in that: Includes steps: S1, adding the organic ligand and cupric chloride dihydrate into a mixed solution of N,N-dimethylformamide and trifluoroacetic acid to carry out a solvothermal reaction to obtain the stable triazole-based metal organic framework material.

3. The preparation method according to claim 2, characterized in that: The preparation method of the organic ligand comprises: (1) 4-bromo-1,2-diaminobenzene, di-tert-butyl dicarbonate and ethanol were stirred at room temperature for at least 24 hours, the precipitate was collected by filtration, and dried in an oven to obtain a solid, namely, compound 1: (2) Under anhydrous and oxygen-free conditions, compound 1, bis(pinacolato)diboron, KOAc, and PdCl2(dppf) were added to dioxane, and heated at 75-115° C. for 12-48 hours under nitrogen. The mixture was extracted with chloroform and washed with brine. The combined organic extracts were dried over anhydrous MgSO4, filtered, and the organic solvent was dried by spin drying. The crude product was purified by column chromatography to obtain a solid, namely compound 2: (3) After 1,3,5-trimethylbenzene, iodine, periodic acid, acetic acid and water are stirred and mixed, concentrated sulfuric acid is added dropwise, and the resulting mixture is heated to reflux at 50 to 120° C. for 10 to 24 hours, filtered by vacuum, and washed with distilled water and acetone, respectively, to obtain a solid, namely compound 3: (4) Compound 3, compound 2, Pd(dppf)Cl2, KOAc, 1,4-dioxane and H2O were added to a reaction vessel, a condenser was connected, and the mixture was degassed by bubbling nitrogen. The reaction was stirred at 75-125°C for three days. After cooling to room temperature, the solvent was removed under reduced pressure, and the crude solid was purified by column chromatography to obtain a white solid, namely, compound 4: (5) Compound 4 was dissolved in tetrahydrofuran solution, concentrated hydrochloric acid solution was added, the mixture was stirred at room temperature overnight, and a solid was obtained by filtration, namely, compound 5: (6) Compound 5, acetic acid and water are added to a reaction vessel, the mixture is cooled in an ice / water bath, an aqueous sodium nitrite solution is slowly added while maintaining the temperature below 10°C, and then stirred at room temperature overnight. The mixture is diluted with water and the organic ligand is obtained by filtering the precipitate.

4. The preparation method according to claim 3, characterized in that: In step (1): The mass ratio of 4-bromo-1,2-diaminobenzene to di-tert-butyl dicarbonate is 1:3; in step (2): The molar ratio of compound 1 to bis(pinacol)diboron is 1:1.5; Pd(dppf)Cl2 was added at 5 mol% of compound 1; The eluent used in the column chromatography is ethyl acetate and petroleum ether, and the volume ratio of the two is 1:4; in step (3): The molar ratio of 1,3,5-trimethylbenzene, iodine and periodic acid is 1:3:0.6; The volume ratio of solvent acetic acid to water is 5:1; The amount of sulfuric acid used is 3 ml; in step (4): The molar ratio of compound 3 to compound 2 is 1:4; Pd(dppf)Cl2 was added at 5 mol% of compound 3; The volume ratio of solvent dioxane to water is 10:1; The eluent used in the column chromatography is ethyl acetate and petroleum ether, and the volume ratio of the two is 1:4; in step (6): The molar ratio of compound 5 to sodium nitrite is 1:1.5; The concentration of the sodium nitrite aqueous solution is 1M; The volume ratio of solvent acetic acid to water is 7:

1.

5. The preparation method according to claim 2, characterized in that: In step S1: The mass ratio of the cupric chloride dihydrate to the organic ligand is not less than 2:1; The volume ratio of N,N-dimethylformamide to trifluoroacetic acid in the mixed solution of N,N-dimethylformamide and trifluoroacetic acid is 1:1; The usage ratio of the organic ligand and the N,N-dimethylformamide is 5 mg:2 mL; The temperature of the solvent thermal reaction is 120-180°C and the time is 24-48h; After the solvothermal reaction is completed, the following post-treatment operation is further performed: the solid product is washed and soaked with N,N-dimethylformamide to obtain the stable triazole-based metal organic framework material.

6. Use of the stable triazole-based metal organic framework material according to claim 1 in solid electrolytes.

7. The use according to claim 6, characterized in that: The metal organic framework material is first activated, then immersed in a tetrahydrofuran solution containing lithium ions or sodium ions to exchange lithium ions or sodium ions, and then used as a solid electrolyte in a solid lithium metal battery or a solid sodium metal battery.

8. The use according to claim 6, characterized in that: The activation treatment is a vacuum drying treatment at 120°C.

9. The use according to claim 6, characterized in that: The lithium ion concentration of the tetrahydrofuran solution containing lithium ions or sodium ions is 0.1-0.5 M, or the sodium ion concentration is 2-5 mg / mL.

10. A solid-state battery, characterized in that: Containing the metal organic framework material as claimed in claim 1 or the solid electrolyte used in claim 6.

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