Bimetal MOF (Metal Organic Framework) material as well as preparation method and application thereof
By preparing bimetallic MOF materials for the positive electrode of lithium-ion hybrid capacitors, the problem that existing materials cannot achieve both high power and high specific energy is solved, and the performance of high-efficiency and low-cost lithium-ion hybrid capacitors is improved, which is suitable for new energy electric vehicles and smart electronic products.
Patent Information
- Application Number
- CN202510995577.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-18
- Publication Date
- 2025-10-17
AI Technical Summary
Existing positive electrode materials for lithium-ion hybrid capacitors cannot achieve both high power and high specific energy. In addition, traditional materials have high energy consumption and high cost during the preparation process, low purity, and poor cycle stability.
By using bimetallic MOF materials, through specific chemical structure and preparation methods, including preparing mixed solutions, heating, precipitation, washing and drying, MOF materials with ordered pore structure and multi-metal synergy are prepared for use as positive electrode materials for lithium-ion hybrid capacitors.
A lithium-ion hybrid capacitor with high rate performance, wide potential window, long cycle life and low cost is achieved. The material has high specific capacity and good conductivity, and is suitable for industrial mass production.
Smart Images
Figure CN120795337A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of lithium ion hybrid capacitors, and particularly relates to a bimetallic MOF material, a preparation method and application thereof. BACKGROUND
[0002] Lithium ion hybrid capacitors, referred to as LIHCs, are energy storage devices combining the advantages of lithium ion batteries and double-layer capacitors, and have high energy density, high power density and long cycle life, and thus show broad application prospects in the fields of new energy electric vehicles and intelligent electronic products.
[0003] Taking a lithium ion hybrid capacitor of a battery type-capacitor type (active carbon) as an example, during charging, a double-layer energy storage is formed by adsorbing anions in an electrolyte on the surface / near-surface of a capacitor type positive electrode, and Li + During discharging, the anions are desorbed from the surface of the positive electrode, and metal cations are desorbed from the negative electrode material and return to the electrolyte, so that the energy density of the LIHCs is mainly provided by the battery type electrode, and the power density is mainly provided by the capacitor type electrode.
[0004] A carbon-based material with a high specific surface area is commonly used as a capacitor type positive electrode material of the LIHCs, and the double-layer formed at the interface between the electrode and the electrolyte is mainly relied on to store energy, which means that the positive electrode is a place for storing electric charges and determines the power density of the lithium ion capacitor, and therefore an excellent positive electrode material must have high conductivity, high specific surface area, developed pore structure, high bulk density and good electrochemical inertness. At present, commonly used positive electrode materials include active carbon, MXenes and metal oxides, but the above-mentioned materials all have defects: the active carbon has a large specific surface area, but its structure is amorphous, which is not conducive to performance prediction; the MXenes have high conductivity and specific volume capacitance, but the voltage window is relatively narrow and the synthesis is relatively complex; the metal oxides have high capacitance, but have poor cycle stability and short service life, and the above-mentioned materials cannot simultaneously have high power and high specific energy. Based on these limitations, a new electrode material is needed. SUMMARY
[0005] The present application aims to provide a bimetallic MOF material, a preparation method and application thereof, so as to solve the problem that the existing materials cannot simultaneously have high power and high specific energy.
[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: a bimetallic MOF material, characterized by comprising a compound A, and the chemical structural formula of the compound A is:
[0007] Wherein M1 and M2 both include one or more of Cu, Zn, Mn, Co, Fe, Zr, Ni, and the sum of the metal species of M1 and M2 is greater than or equal to 2.
[0008] The beneficial effects of the present scheme are: 1. The MOF in the present scheme has an ordered pore structure, which is conducive to the rapid transmission of ions, thereby realizing high rate, and has higher specific capacity compared with existing positive electrode materials. Secondly, although there are MOF materials at present, the current MOF materials rely on single metal nodes, and the selectivity of catalysis, adsorption and redox is limited. The bimetallic MOF material in the present scheme has a bimetallic structure, in which at least two metals cooperate with each other. From the perspective of energy storage, the MOF material in the present scheme has different metal sites, which enhances the ion conductivity, improves the rate performance, and the multi-metal design also makes the material have higher capacity.
[0009] Moreover, the MOF material in the present scheme can adjust the pore size (from microporous to mesoporous) and surface chemical properties by changing the length, functional groups (such as —NH2, —COOH, —OH) or symmetry of the ligand; selecting different metals (Zn²⁺, Cu²⁺, Zr 4+ , etc.) or constructing multi-metal clusters (such as Zr6-O8 clusters), which can adjust the coordination environment and framework strength, i.e. the MOF material in the present scheme also has structural adjustability, which can also enhance the stability of the skeleton.
[0010] 2. The bimetallic MOF material in the present scheme is a polymer molecule with high symmetry, which effectively improves the problem that small organic molecules are easily soluble in organic electrolyte, and the active site in the material is rich in variety, in which the metal ions are located at the center, and both the organic ligand and the metal ions can be active centers for electrochemical reaction, thereby realizing the regulation of the material charge and discharge voltage, capacity, energy density and other parameters through the molecular structure. Moreover, the porous structure and adjustable defects of the material realize obvious advantages in high capacity, long life and fast charging and discharging.
[0011] 3. The π-d interaction between the bimetallic and the π-rich organic molecules such as porphyrin in the present scheme can greatly improve the conduction of electrons in the MOF molecule, thereby further improving the conductivity and improving the rate performance.
[0012] A preparation method of a bimetallic MOF material, for preparing the above-mentioned bimetallic MOF material, comprising the following steps: Step 1: configure a mixed solution comprising 4-formylbenzoic acid methyl ester, dissolve the pyrrole in propionic acid and add the mixed solution, wherein 1-2 g of pyrrole is dissolved in 50 ml of propionic acid, the ratio between the volume of propionic acid and the amount of substance of 4-formylbenzoic acid methyl ester is 40-80 ml:0.02-0.03 mol, and then heated to reflux, and after the reaction is completed, first cooled to room temperature, and then separated to obtain a purple solid; Step 2: dissolve the purple solid in N,N-dimethylformamide, then add an M1Cl2 solution and heat to reflux, and after the reaction is completed, cool to room temperature, and separate to obtain a precipitate; Step 3: dissolve the precipitate in a CHCl3 solution, perform acid washing with hydrochloric acid, and then wash with ultrapure water, remove water from the solution, and then filter to obtain a solution; Step 4: remove the solvent from the solution to obtain TCPPOOMe-M1; Step 5: mix THF and methanol solutions in a ratio of 2-3:1, dissolve TCPPOOMe-M1 and KOH in the above-mentioned solution in an amount-of-substance ratio of 0.05-0.1:0.059-0.13, after the reaction is completed, add water in a ratio of 1:3-4 between the volume of the water and the total volume of the above-mentioned solution, heat the mixture to complete dissolution, then add hydrochloric acid for acidification in an amount-of-substance ratio of 50-70:0.05 between the hydrochloric acid and TCPPOOMe-M1, and finally collect the precipitate to obtain M1-TCPP; Step 6: dissolve M2(CH3COO)x in ethanol to configure a metal ion solution; configure a CHCl3-ethanol solution, disperse dry M1-TCPP in the CHCl3-ethanol solution, then add a cosolvent and a base to obtain a dispersion, wherein the weight of the base is greater than or equal to the weight of ethanol; finally, mix the dispersion with the metal ion solution, wherein the cosolvent comprises a mixture of one or more of DMSO and DMF, and the volume of the cosolvent is 3-10% of the total volume of the mixed solution system after the dispersion and the metal ion solution are mixed, and finally filter to obtain a solid; Step 7: dry the solid obtained in step 6 in a vacuum environment at 50-75°C to obtain an M1-TCPP-M2 MOF material. The beneficial effects of the present scheme are: 1. The current process of introducing metal ions all needs to use high temperature to reduce the activation energy barrier of the reaction and improve the crystallinity, and the difficulty coefficient of the reaction is large. However, the reaction condition of step 6 of the present scheme when introducing the second metal ion M2 can be carried out at room temperature, which reduces energy consumption and also does not need to control the temperature, thereby effectively reducing the preparation difficulty. Moreover, the base added in step 6 can promote the deprotonation of the carboxyl group, thereby accelerating the coordination effect with M2 and improving the yield and purity of M1-TCPP-M2 MOF.
[0013] 2. The scheme effectively reduces energy consumption because no high-temperature heating is required in all preparation steps, and the raw materials used are low-cost, renewable, and environmentally friendly, making it more suitable for large-scale industrial production. Second, the preparation method in this scheme does not introduce inorganic salt impurities during the preparation process, and the subsequent treatment is simple, and the purity of the material obtained in step 7 is higher.
[0014] Further, the base is one or more of triethylamine, ammonia, NaOH, and KOH.
[0015] Further, step 4 heats the solution to 50-60℃, and distills the solution to remove the solvent in the solution.
[0016] Further, step 2 adds water after cooling to room temperature.
[0017] Further, after adding water in step 2, the solution is allowed to stand, and then the precipitate is separated.
[0018] The beneficial effects of this scheme are that standing can ensure that the precipitate is fully precipitated, making it easier to separate from the liquid.
[0019] Further, the purple solid obtained in step 1 and the TCPPOOMe-M1 obtained in step 4 are both washed with ethanol and dried before participating in the preparation of the next step.
[0020] The beneficial effects of this scheme are that washing and drying can further remove impurities in TCPPOOMe-M1, thereby improving the purity of M1-TCPP-M2 MOF material.
[0021] The application also protects the application of a kind of bimetallic MOF material, the bimetallic MOF material is applied to lithium ion hybrid capacitor pole piece.
[0022] The beneficial effects of this scheme are that after testing, the lithium ion hybrid capacitor using the above bimetallic MOF material has a wide potential window, a long cycle life, and good rate performance, and the preparation method is simple, the preparation cost is low, and the practicality is strong.
[0023] Further, the preparation of the lithium ion hybrid capacitor pole piece includes the following steps: Step 1: Mix M1-TCPP-M2 MOF material, PVDF, and Super-P in a mass ratio of 79-89:5-15:5-15, then mix with NMP to prepare a slurry; Step 2: Coat the slurry on an aluminum foil and then dry it in an environment of 65-80℃; Step 3: Roll and cut the pole piece in sequence.
[0024] The M1-TCPP-M2 MOF material in the application has a wider stable window, a larger specific capacity, and a longer service life. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 SEM image of the M1-TCPP-M2 material prepared in Embodiment 1 of the application; Figure 2 XRD image of the M1-TCPP-M2 material prepared in Embodiment 1 of the application; Figure 3 LSV image of the capacitor prepared from the MOF material in Embodiment 1 of the application; Figure 4 CV image of the capacitor prepared from the MOF material in Embodiment 1 of the application; Figure 5 Rate performance test of the capacitor prepared from the MOF material in Embodiment 1 of the application; Figure 6 Cycle life test result of the capacitor prepared from the MOF material in Embodiment 1 of the application. DETAILED DESCRIPTION
[0026] The application will be described in further detail below through specific embodiments: Embodiment 1 This embodiment 1 discloses a double-metal MOF material, which comprises a compound A, and the chemical structural formula of the compound A is as follows:
[0027] wherein M1 and M2 each comprises one or more of Cu, Zn, Mn, Co, Fe, Zr and Ni, and the sum of the metal types of M1 and M2 is equal to 2, and specifically, M1 in this embodiment is Co and M2 is Mn.
[0028] This embodiment also discloses a preparation method of a double-metal MOF material, which is used for preparing the double-metal MOF material, and comprises the following steps: Step 1: a mixed solution comprising 4-formylbenzoic acid methyl ester is configured, pyrrole is dissolved in 200 ml of propionic acid and then added dropwise into the mixed solution, 1-2 g of pyrrole is dissolved in 50 ml of propionic acid, the ratio between the volume of propionic acid and the amount of substance of 4-formylbenzoic acid methyl ester is 40-80 ml:0.02-0.03 mol, and then heated to reflux, the reaction is ended after 8-12 h of reaction, cooled to room temperature first, and then separated by suction filtration to obtain a purple solid; finally, the purple solid is washed with ethanol and dried in a vacuum environment after washing; Step 2: The purple solid is dissolved in dimethylformamide, CoCl2 solution is added and heated to reflux in the dark for 8-12 h, then cooled to room temperature, 50-150 mL of ultrapure water is added, and after standing, the precipitate is obtained by suction filtration; Step 3: The precipitate is dissolved in a CHCl3 solution, washed with hydrochloric acid, and washed with ultrapure water, then anhydrous magnesium sulfate or anhydrous sodium sulfate is used to remove water from the solution, and then filtered to obtain a solution; Step 4: The solution is heated to 55°C, and the solvent in the solution is removed by pressure distillation to obtain TCPPOOMe-Co; the TCPPOOMe-Co solid is washed with ethanol, and the washed TCPPOOMe-Co is dried under vacuum at a temperature of 50-75°C; Step 5: THF and methanol solution are mixed in a ratio of 1:1, 0.05 mM of TCPPOOMe-Co and 0.059 mM of KOH are dissolved in the above solution, 100-150 mL of water is added after the reaction is complete, the mixture is heated to complete dissolution, 50-70 mL of 1 mol / L concentration of hydrochloric acid is added for acidification, then it is left to stand, and after standing, the precipitate is collected to obtain Co-TCPP, which is finally washed with water and vacuum dried; Step 6: M2(CH3COO)x is dissolved in ethanol, specifically, M2(CH3COO)x in this embodiment is Mn(CH3COO)2, a metal ion solution is prepared; a CHCl3-ethanol solution is prepared, the dried Co-TCPP is dispersed in the CHCl3-ethanol solution, a cosolvent and a base are added to obtain a dispersion, wherein the base is one or more of triethylamine, ammonia, NaOH, and KOH, the amount of base is greater than or equal to the amount of ethanol, specifically, the weight ratio of base to ethanol is 1-3:1, and the base is triethylamine; finally, the dispersion is added dropwise to the metal ion solution and mixed with the metal ion solution, and the solid is filtered to obtain a solid; the above-mentioned cosolvent includes a mixture of one or more of DMSO and DMF, and the volume of the cosolvent is 3-10% of the total volume of the mixed solution system after the dispersion and the metal ion solution are mixed; Step 7: The solid obtained in step 6 is dried in a vacuum environment at 50-75°C to obtain a Co-TCPP-Mn MOF material.
[0029] Specifically, the reflux method of steps 1 and 2 and the washing method of claims 1, 3, and 4 are the same as the prior art, and will not be described in detail in this embodiment.
[0030] The Co-TCPP-Mn MOF material prepared by the above method was measured by scanning electron microscope and X-ray irradiation crystal, and the SEM image of the Co-TCPP-Mn MOF material is shown in FIG. 1, which shows that the Co-TCPP-Mn MOF material prepared by the preparation method of the embodiment is a ordered porous structure; and the XRD image is shown in FIG. 2, which shows that the Co-TCPP-Mn MOF material prepared by the preparation method of the embodiment has a crystal structure of a bimetallic MOF. Figure 1 The Co-TCPP-Mn MOF material prepared by the above method was measured by scanning electron microscope and X-ray irradiation crystal, and the SEM image of the Co-TCPP-Mn MOF material is shown in FIG. 1, which shows that the Co-TCPP-Mn MOF material prepared by the preparation method of the embodiment is a ordered porous structure; and the XRD image is shown in FIG. 2, which shows that the Co-TCPP-Mn MOF material prepared by the preparation method of the embodiment has a crystal structure of a bimetallic MOF. Figure 2 The Co-TCPP-Mn MOF material prepared by the above method was measured by scanning electron microscope and X-ray irradiation crystal, and the SEM image of the Co-TCPP-Mn MOF material is shown in FIG. 1, which shows that the Co-TCPP-Mn MOF material prepared by the preparation method of the embodiment is a ordered porous structure; and the XRD image is shown in FIG. 2, which shows that the Co-TCPP-Mn MOF material prepared by the preparation method of the embodiment has a crystal structure of a bimetallic MOF.
[0031] The Co-TCPP-Mn MOF material prepared by the above method was measured by scanning electron microscope and X-ray irradiation crystal, and the SEM image of the Co-TCPP-Mn MOF material is shown in FIG. 1, which shows that the Co-TCPP-Mn MOF material prepared by the preparation method of the embodiment is a ordered porous structure; and the XRD image is shown in FIG. 2, which shows that the Co-TCPP-Mn MOF material prepared by the preparation method of the embodiment has a crystal structure of a bimetallic MOF. Step 1: The Co-TCPP-Mn MOF material, PVDF and Super-P are mixed in a mass ratio of 79-89:5-15:5-15, and then mixed with NMP to prepare a slurry; Step 2: The slurry is coated on an aluminum foil, and then dried at 65-80°C; Step 3: The slurry is coated on an aluminum foil, and then dried at 65-80°C;
[0032] The prepared electrode sheet is made into a lithium metal negative electrode hybrid capacitor, wherein the positive and negative electrode shells are of type 2032, and the following tests are performed: I. LSV test: The instrument used is a Shanghai Chenhua electrochemical workstation, and the scan speed is set to 0.002 V / s, as shown in FIG. 6, the electrochemical stability window is 1.6-4.8 V, which shows that the MOF material in the application has a wider stability window and better stability. Figure 3
[0033] II. CV test: The instrument used is a Shanghai Chenhua electrochemical workstation, and the scan speed is set to 0.0002-0.005 V / s, and the voltage window is 1.5-4.5 V, as shown in FIG. 7, the test results show that there is no obvious redox peak, which shows that the MOF material belongs to a capacitive material. Figure 4
[0034] III. Rate performance test: The instrument used is a Wuhan Lan electric electrochemical workstation, and the current density is set to 0.1 A / g, 0.2 A / g, 0.5 A / g, 1 A / g, 2 A / g and 5 A / g, and the specific capacity corresponding to the rate is shown in FIG. 8, which shows that the MOF material in the application has a large specific capacity. Figure 5
[0035] IV. Cycle life test: The instrument used is a Wuhan Lan electric electrochemical workstation, and the current density is set to 1 A / g, as shown in FIG. 9, which shows that the MOF material in the application has a long cycle life. Figure 6 As shown, after about 2400 cycles, the battery is damaged, indicating that the MOF material in the application has a long service life.
[0036] The present application adopts Comparative Example 1 and Comparative Example 2: Comparative Example 1 adopts: Jiangsu University of Science and Technology Qin et al. with 1,4,5,8-naphthalene tetracarboxylic acid as ligand, a kind of petal-like bimetallic Co / Zn-NTCA MOFs material with thin layer structure synthesized by multi-solvent thermal method, please refer to the literature: Qin C, Pengfei M, et al. Zn2+ significantly enhances the performance of petal-like Co-naphthalenetetracarboxylic acid MOF as an anode material for lithium-ion batteries[J], Chinese Journal of Chemical Engineering 2025.79, 164-171.
[0037] Comparative Example 2 adopts: Lanzhou University Li Zhan research team adopts simple, mild, one-step solvothermal process to prepare Ni-MOF crystal, please refer to Wang J, Liang J, Lin Y. Nanowire stacked bimetallic metal-organic frameworks for asymmetric supercapacitor[J]. Chemical engineering journal, 2022.
[0038] The material of the above comparative example 1 has a capacity retention rate of about 50%~55% after 500 cycles at 1A / g, and the material of the above comparative example 2 has a specific capacity of 108.5 mAh g -1 And the present application adopts a simple and green way to prepare MOF material, the specific capacity can reach 350 mAh / g at a current density of 1 / g, and the cycle can be cycled more than 2000 times, and the capacity retention rate is more than 90%, far more than the existing MOF material.
[0039] The above-mentioned are only embodiments of the present application, and common technical solutions and / or common knowledge of the scheme are not described in detail. It should be pointed out that, for those skilled in the art, without departing from the technical solutions of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, and these will not affect the effect and practicality of the patent. The protection scope claimed in the present application should be subject to the content of its claims, and the specific implementation mode and the like recorded in the specification can be used to explain the content of the claims.
Claims
1. A bimetallic MOF material, characterized in that: Including compound A, the chemical structural formula of compound A is: Wherein, M1 and M2 both include one or more of Cu, Zn, Mn, Co, Fe, Zr, and Ni, and the sum of the metal types of M1 and M2 is greater than or equal to 2.
2. A method for preparing a bimetallic MOF material, characterized in that: The method for preparing the bimetallic MOF material comprises the following steps: Step 1: preparing a mixed solution including methyl 4-formylbenzoate, dissolving pyrrole in propionic acid and adding the solution to the mixed solution, wherein 1-2 g of pyrrole is dissolved per 50 ml of propionic acid, and the ratio between the volume of propionic acid and the amount of methyl 4-formylbenzoate is 40-80 ml:0.02-0.03 mol, then heating to reflux, cooling to room temperature after the reaction is completed, and then isolating to obtain a purple solid; Step 2: Dissolve the purple solid in N,N-dimethylformamide, add M1Cl2 solution and heat to reflux. After the reaction is completed, cool to room temperature and separate the precipitate. Step 3: dissolving the precipitate in a CHCl3 solution, washing with hydrochloric acid, and washing with ultrapure water, then removing water from the solution and filtering to obtain a solution; Step 4: Remove the solvent from the solution to obtain TCPPOOMe-M1; Step 5: THF and methanol solution are mixed in a ratio of 2-3:1, TCPPOOMe-M1 and KOH are dissolved in the above solution in a ratio of 0.05-0.1:0.059-0.13 of the amount of substance, and water is added after the reaction is completed, and the ratio of the volume of the water to the total volume of the above solution is 1:3-4; after the mixture is heated until completely dissolved, hydrochloric acid is added for acidification, wherein the amount of hydrochloric acid to TCPPOOMe-M1 is 50-70:0.05, and finally the precipitate is collected to obtain M1-TCPP; Step 6: M2(CH3COO) x dissolving in ethanol to prepare a metal ion solution; preparing a CHCl3-ethanol solution, dispersing the dried M1-TCPP in the CHCl3-ethanol solution, and then adding a cosolvent and a base to obtain a dispersion, wherein the weight of the base is greater than or equal to the weight of ethanol; finally, mixing the dispersion with the metal ion solution, wherein the cosolvent includes a mixture of one or more of DMSO and DMF, and the volume of the cosolvent is 3-10% of the total volume of the mixed solution system after the dispersion and the metal ion solution are mixed, and finally filtering to obtain a solid; Step 7: The solid obtained in step 6 is dried under a vacuum environment at 50-75°C to obtain the M1-TCPP-M2 MOF material.
3. The method for preparing a bimetallic MOF material according to claim 2, wherein: The base is one or more of triethylamine, ammonia water, NaOH and KOH.
4. The method for preparing a bimetallic MOF material according to claim 2, wherein: Step 4: Heat the solution to 50-60° C. and distill the solution to remove the solvent.
5. The method for preparing a bimetallic MOF material according to claim 2, wherein: Step 2: After cooling to room temperature, water is added first.
6. The method for preparing a bimetallic MOF material according to claim 5, characterized in that: Step 2: Add water and let it stand, then separate the precipitate.
7. The method for preparing a bimetallic MOF material according to claim 6, characterized in that: The purple solid obtained in step 1 and the TCPPOOMe-M1 obtained in step 4 were washed with ethanol and dried before participating in the preparation of the next step.
8. The use of a bimetallic MOF material according to claim 7, characterized in that: Applied to lithium-ion hybrid capacitor pole pieces.
9. The method for preparing a bimetallic MOF material according to claim 8, characterized in that: The preparation of lithium-ion hybrid capacitor pole pieces includes the following steps: Step 1: M1-TCPP-M2 MOF material, PVDF, and Super-P are mixed in a mass ratio of 79-89: 5-15: 5-15, and then mixed with NMP to prepare a slurry; Step 2: Apply the slurry onto aluminum foil and dry it at 65-80°C. Step 3: The electrode is produced by rolling and cutting in sequence.