Inorganic-organic metal framework gel material as well as preparation method and application thereof

Abstract

The invention discloses an inorganic-organic metal framework gel material as well as a preparation method and application thereof. The inorganic-organic metal framework gel material is obtained by polymerizing a polymer monomer and an organic metal framework; the polymer monomer is selected from at least one of acrylamide, vinyl alcohol and acrylic acid; the organic metal framework is selected from at least one of ZIF-8, ZIF-67, ZIF-7, UIO-66, MIL-88, MOF-74 and MOF-5, and the organic metal framework is selected from at least one of ZIF-8, ZIF-67, ZIF-7, UIO-66, MIL-88, MOF-74 and Due to the existence of the MOFs gel, the transportation performance of ions is improved; the mechanical strength of the gel is improved through organic-inorganic penetration, so that the service life of the water-based zinc ion battery is prolonged in the circulating process.

Description

Technical Field

[0001] The present application relates to an inorganic-organic metal framework gel material and a preparation method and application thereof, belonging to the field of electrolyte materials. Background Art

[0002] Since Sony first commercialized lithium-ion batteries in 1991, they have been widely used in portable electronics, electric vehicles, energy storage and other fields due to their high energy efficiency, long cycle life and high energy density. However, the scarcity of lithium resources, the uneven distribution of lithium resources in the world and the high price of lithium salts have hindered the sustainable development of lithium-ion batteries. At the same time, lithium-ion batteries also have disadvantages such as poor safety, leakage of organic electrolytes and easy explosion. In recent years, aqueous zinc-ion batteries (AZBs) have been widely used due to their low cost, environmental friendliness, abundant raw materials, high theoretical capacity (820mAh g -1 ) and low overpotential (-0.76V vs. standard hydrogen electrode), and has attracted widespread attention.

[0003] Flexible electrochemical energy storage devices are gradually emerging, and gel electrolytes with shape adjustability, good flexibility and good mechanical properties have been widely studied. The problems of zinc-ion batteries include: zinc negative electrode dendrite growth, zinc corrosion, hydrogen evolution and other side reactions, which will not only reduce ionic conductivity, but also cause battery short circuit failure during the cycle. At the same time, since flexible batteries must meet bending and impact requirements during use, this requires the gel electrolyte used in the battery to have higher mechanical properties. Summary of the invention

[0004] Metal-organic framework (MOF) is a kind of highly ordered porous crystalline material composed of organic linkers and metal-containing clusters through coordination bonds. It has high stability, chemical diversity, ultra-high specific area, and high porosity. ZIF-8 is a sodium salt topological MOF with 2-methylimidazole (MeIM) ligands and zinc centers. It has excellent chemical stability, moisture resistance and ultra-microporous structure. It can be used to prepare MOF gel electrolytes to improve ionic conductivity.

[0005] The purpose of the present invention is to provide a preparation method and application of an inorganic-organic metal framework gel electrolyte. MOF has the ability to store more electrolytes and regulate the ion transfer process due to its high specific surface area, adjustable pore size, flexible chemical structure and adjustable organic ligand. Metal organic framework (MOF) improves the ion transport performance due to the presence of a large number of micro / mesopores and functional pores; organic-inorganic penetration improves the mechanical strength of the gel, and inhibits the growth of dendrites by adjusting ion deposition and promoting ion conduction. The manufactured gel electrolyte can effectively avoid liquid leakage.

[0006] According to one aspect of the present application, an inorganic-organic metal framework gel material is provided, wherein the inorganic-organic metal framework gel material is obtained by polymerizing a polymer monomer and an organic metal framework;

[0007] The polymer monomer is selected from at least one of acrylamide, vinyl alcohol and acrylic acid;

[0008] The organic metal framework is selected from at least one of ZIF-8, ZIF-67, ZIF-7, UIO-66, MIL-88, MOF-74, and MOF-5.

[0009] According to another aspect of the present application, a method for preparing the above-mentioned inorganic-organic metal framework gel material is provided, comprising the following steps:

[0010] The organic metal framework gel is mixed with an aqueous solution containing a polymer monomer, a crosslinking agent and an initiator, and then an accelerator is added, polymerized in a mold, and dried to obtain the inorganic-organic metal framework gel material.

[0011] The organic metal framework gel is selected from at least one of ZIF-8 gel, ZIF-67 gel, ZIF-7 gel, UIO-66 gel, MIL-88 gel, MOF-74 gel and MOF-5 gel;

[0012] The crosslinking agent is selected from at least one of N,N'methylenebisacrylamide, ethylene glycol diacrylate, 1,4-butanediol diacrylate, and ethylene glycol dimethacrylate;

[0013] The initiator is selected from at least one of ammonium persulfate, potassium persulfate, benzoyl oxide, and tert-butyl hydroperoxide.

[0014] In the aqueous solution containing polymer monomers, crosslinking agents and initiators, the content of the polymer monomers is 150-350 mg / ml;

[0015] The mass ratio of the cross-linking agent to the polymer monomer is 0.002:1 to 0.004:1;

[0016] The mass ratio of the initiator to the polymer monomer is 0.002:1 to 0.004:1.

[0017] The accelerator is selected from tetramethylethylenediamine;

[0018] The volume ratio of the accelerator to the aqueous solution containing the polymer monomer, the cross-linking agent and the initiator is 3:1 to 4:1.

[0019] The polymerization temperature is 20 to 30°C;

[0020] The polymerization time is 1 to 4 hours;

[0021] The drying temperature is 40-80°C;

[0022] The drying time is 6 to 36 hours.

[0023] Soak in water after drying;

[0024] The soaking time is 12 to 48 hours.

[0025] The dosage ratio of the organic metal framework gel to the aqueous solution containing polymer monomers, a crosslinking agent and an initiator is 2:1 to 3:1.

[0026] According to another aspect of the present application, an inorganic-organic metal framework gel electrolyte is provided, comprising the above-mentioned inorganic-organic metal framework gel material.

[0027] The thickness of the inorganic-organic metal framework gel electrolyte is 0.5 mm to 1 mm.

[0028] According to another aspect of the present application, an application of the above-mentioned inorganic-organic metal framework gel electrolyte is provided, which is used in aqueous zinc ion batteries, supercapacitors, zinc-air batteries, and flexible wearable electronic equipment.

[0029] The beneficial effects of this application include:

[0030] 1) The presence of metal organic framework MOFs gel improves the ion transport performance; the organic-inorganic interpenetration jointly improves the mechanical strength of the gel, which prolongs the life of the aqueous zinc-ion battery during the cycle process.

[0031] 2) The present invention proposes a method for preparing an inorganic-organic metal framework gel electrolyte and its application. The preparation method is simple, environmentally friendly, has high ionic conductivity and good safety performance. In the process of combining MOFs with hydrogel, the side groups (such as -NH 2 , -OH, etc.) are easy to coordinate with the metal ions that construct MOFs, which is beneficial to enhance the stability of MOFs in the hydrogel system. The synergistic effect of the highly wettable porous framework and polyacrylamide gel produces a high Zn 2+ Transfer number. Distributing MOFs in the three-dimensional network structure of hydrogel will further improve the mechanical properties of hydrogel. At the same time, it can effectively improve the disadvantage of MOFs' easy decomposition and improve MOFs' stability, processability and recyclability.

[0032] 3) Due to the presence of metal organic framework MOFs gel, the prepared gel electrolyte has a large number of micro / mesopores and functional channels, which leads to an increase in the number of free particles and a higher ionic conductivity, which can reach 40mS cm at room temperature. -1 . BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Symmetrical cycle curve of a symmetric battery assembled with the inorganic-organic metal framework gel electrolyte prepared in Example 1.

[0034] Figure 2 This is the SEM image of the zinc plate of the inorganic-organic metal framework gel electrolyte symmetric battery prepared in Example 1 after 100 cycles, with a scale of 1 μm.

[0035] Figure 3 This is the Zn / Cu coulombic efficiency diagram of the inorganic-organic metal framework gel electrolyte assembled in Example 1.

[0036] Figure 4 The rate diagram of the symmetrical battery assembled with the inorganic-organic metal framework gel electrolyte prepared in Example 1 at different current densities.

[0037] Figure 5 The ionic conductivity of the inorganic-organic metal framework gel electrolyte prepared in Example 1 at different temperatures.

[0038] Figure 6 This is an electron microscope image of the inorganic-organic metal framework gel electrolyte prepared in Example 1, with a scale of 100 μm.

[0039] Figure 7 This is an electron microscope image of the inorganic-organic metal framework gel electrolyte prepared in Example 1, with a scale of 5 μm. DETAILED DESCRIPTION

[0040] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0041] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0042] Embodiment 1:

[0043] 1 g of acrylamide was dissolved in 6 mL of deionized water, and then 0.003 g of N,N'methylenebisacrylamide and 0.003 g of ammonium persulfate were added in sequence until completely dissolved to obtain an acrylamide mixed solution, which was poured into 16.5 mL of organic metal framework ZIF-8 gel and stirred evenly; after adding 0.02 L of tetramethylethylenediamine, it was immediately poured into a mold and polymerized at room temperature for 1 to 2 hours; the obtained gel was placed in an 80°C oven for drying for 12 hours, and then soaked in deionized water for 24 hours after drying to finally obtain an inorganic-organic metal framework gel electrolyte.

[0044] Figure 1 The symmetric cycle curve of the symmetric battery assembled with the inorganic-organic metal framework gel electrolyte prepared in Example 1 shows that the polarization voltage is small and stable during the cycle.

[0045] Figure 2 This is the SEM image of the zinc plate of the inorganic-organic metal framework gel electrolyte symmetric battery prepared in Example 1 after 100 cycles, with a scale of 1 μm. It can be seen that the zinc plate is relatively flat after the cycle and the growth of zinc dendrites is suppressed.

[0046] Figure 3 This is the coulombic efficiency diagram of Zn / Cu assembled with the inorganic-organic metal framework gel electrolyte prepared in Example 1. It can be seen that the coulombic efficiency remains stable after 70 cycles.

[0047] Figure 4 The rate diagram of the symmetrical battery assembled with the inorganic-organic metal framework gel electrolyte prepared in Example 1 at different current densities shows that the polarization voltage does not have obvious fluctuations at different current densities and remains stable.

[0048] Figure 5 The ionic conductivity of the inorganic-organic metal framework gel electrolyte prepared in Example 1 at different temperatures. It can be seen from the figure that the conductivity increases with the increase of temperature, indicating that the prepared inorganic-organic metal framework gel electrolyte also has good Zn 2+ Conductive properties.

[0049] Figure 6 This is an electron microscope image of the inorganic-organic metal framework gel electrolyte prepared in Example 1, with a scale of 100 μm. It can be seen from the image that the prepared inorganic-organic metal framework gel electrolyte has an interpenetrating structure.

[0050] Figure 7 This is an electron microscope image of the inorganic-organic metal framework gel electrolyte prepared in Example 1, with a scale of 5 μm. From the image, it can be seen that the MOF particles in the prepared inorganic-organic metal framework gel electrolyte are tightly attached to the organic framework.

[0051] Embodiment 2:

[0052] 1 g of acrylamide was dissolved in 6 mL of deionized water, and then 0.003 g of N,N'methylenebisacrylamide and 0.003 g of ammonium persulfate were added in sequence until completely dissolved to obtain an acrylamide mixed solution, which was poured into 16.5 mL of organic metal framework ZIF-8 gel and stirred evenly; after adding 0.02 L of tetramethylethylenediamine, it was immediately poured into a mold and polymerized at room temperature for 1 to 2 hours; the obtained gel was placed in an 80°C oven for drying for 12 hours, and then soaked in deionized water for 24 hours after drying to finally obtain an inorganic-organic metal framework gel electrolyte.

[0053] Embodiment 3:

[0054] 1 g of acrylamide was dissolved in 6 mL of deionized water, and then 0.003 g of N,N'methylenebisacrylamide and 0.003 g of ammonium persulfate were added in sequence until completely dissolved to obtain an acrylamide mixed solution, which was poured into 16.5 mL of organic metal framework ZIF-8 gel and stirred evenly; after adding 0.02 L of tetramethylethylenediamine, it was immediately poured into a mold and polymerized at room temperature for 1 to 2 hours; the obtained gel was placed in an 80°C oven for drying for 12 hours, and then soaked in deionized water for 24 hours after drying to finally obtain an inorganic-organic metal framework gel electrolyte.

[0055] Embodiment 4:

[0056] 0.5 g of acrylamide was dissolved in 6 mL of deionized water, and then 0.0015 g of N,N'methylenebisacrylamide and 0.0015 g of ammonium persulfate were added in sequence until completely dissolved to obtain an acrylamide mixed solution, which was poured into 16.5 mL of organic metal framework ZIF-8 gel and stirred evenly; after adding 0.02 L of tetramethylethylenediamine, it was immediately poured into a mold and polymerized at room temperature for 1 to 2 hours; the obtained gel was placed in an 80°C oven for drying for 12 hours, and then soaked in deionized water for 24 hours after drying to finally obtain an inorganic-organic metal framework gel electrolyte.

[0057] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. An inorganic-organic metal framework gel material, characterized in that: The inorganic-organic metal framework gel material is obtained by polymerizing a polymer monomer and an organic metal framework; The polymer monomer is selected from at least one of acrylamide, vinyl alcohol and acrylic acid; The organic metal framework is selected from at least one of ZIF-8, ZIF-67, ZIF-7, UIO-66, MIL-88, MOF-74, and MOF-5.

2. A method for preparing the inorganic-organic metal framework gel material according to claim 1, characterized in that: The following steps are involved: The organic metal framework gel is mixed with an aqueous solution containing a polymer monomer, a crosslinking agent and an initiator, and then an accelerator is added, polymerized in a mold, and dried to obtain the inorganic-organic metal framework gel material.

3. The preparation method according to claim 1, characterized in that: The organic metal framework gel is selected from at least one of ZIF-8 gel, ZIF-67 gel, ZIF-7 gel, UIO-66 gel, MIL-88 gel, MOF-74 gel and MOF-5 gel; The crosslinking agent is selected from at least one of N,N'methylenebisacrylamide, ethylene glycol diacrylate, 1,4-butanediol diacrylate, and ethylene glycol dimethacrylate; The initiator is selected from at least one of ammonium persulfate, potassium persulfate, benzoyl oxide, and tert-butyl hydroperoxide.

4. The preparation method according to claim 1, characterized in that: In the aqueous solution containing polymer monomers, crosslinking agents and initiators, the content of the polymer monomers is 150-350 mg / ml; The mass ratio of the cross-linking agent to the polymer monomer is 0.002:1 to 0.004:1; The mass ratio of the initiator to the polymer monomer is 0.002:1 to 0.004:

1.

5. The preparation method according to claim 1, characterized in that: The accelerator is selected from tetramethylethylenediamine; The volume ratio of the accelerator to the aqueous solution containing the polymer monomer, the cross-linking agent and the initiator is 3:1 to 4:

1.

6. The preparation method according to claim 1, characterized in that: The polymerization temperature is 20 to 30°C; The polymerization time is 1 to 4 hours; The drying temperature is 40-80°C; The drying time is 6 to 36 hours.

7. The preparation method according to claim 1, characterized in that: Soak in water after drying; The soaking time is 12 to 48 hours.

8. The preparation method according to claim 1, characterized in that: The dosage ratio of the organic metal framework gel to the aqueous solution containing polymer monomers, a crosslinking agent and an initiator is 2:1 to 3:

1.

9. An inorganic-organic metal framework gel electrolyte, characterized in that: Containing the inorganic-organic metal framework gel material according to claim 1; The thickness of the inorganic-organic metal framework gel electrolyte is 0.5 mm to 1 mm.

10. An application of the inorganic-organic metal framework gel electrolyte according to any one of claims 9, characterized in that: Used in aqueous zinc-ion batteries, supercapacitors, zinc-air batteries, and flexible wearable electronic equipment.

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