A method for preparing a sulfonated modified zirconium-based metal organic framework / grafted sulfonated polybenzimidazole composite membrane for a vanadium redox flow battery
Patent Information
- Application Number
- CN202510430423.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-08
- Publication Date
- 2026-10-16
AI Technical Summary
目前，市场上使用的最广泛的一类膜是全氟磺酸膜(以Nafion为代表)，这类膜具备高质子传导率及高氧化稳定性，但由于其成本过高、钒离子透过率过高等限制了发展
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Abstract
Description
Technical Field
[0001] This invention belongs to the fields of polymer chemistry and vanadium redox flow batteries, and relates to a method for preparing a sulfonated modified zirconium-based metal-organic framework / grafted sulfonated polybenzimidazole composite membrane for all-vanadium redox flow batteries. Background Technology
[0002] Vanadium redox flow batteries have attracted widespread attention in existing electrochemical energy storage systems due to their controllable capacity, high reliability, long cycle life, and cost-effectiveness. The vanadium redox flow battery was first proposed in 1985 by Maria Skyllas-Kazacos of the University of New South Wales, Australia. The ion exchange membrane is a key component of the vanadium redox flow battery, its function being to isolate the positive and negative electrolytes, prevent cross-contamination, and allow proton transport to complete the current circuit. Currently, the most widely used type of membrane on the market is the perfluorosulfonic acid membrane (represented by Nafion), which possesses high proton conductivity and high oxidation stability; however, its development is limited by its high cost and high vanadium ion permeability. Currently, researchers are exploring the application of non-fluorinated ion exchange membranes such as polybenzimidazole (PBI), sulfonated polyether ether ketone (SPEEK), and polyarylether ketone (PAEK) in vanadium redox flow batteries. Summary of the Invention
[0003] The purpose of this invention is to provide a method for preparing a sulfonated modified zirconium-based metal-organic framework / grafted sulfonated polybenzimidazole composite membrane for vanadium redox flow batteries. This composite proton exchange membrane exhibits good proton conductivity, vanadium blocking ability, and battery performance. The prepared sPBI B5 The proton conductivity of -MS5 reaches 43.1 mS / cm at 30°C. -1 After 200 charge-discharge cycles, it demonstrated excellent long-term cycling stability. Furthermore, the preparation method is simple and low-cost. This invention first provides a method for preparing a sulfonated modified zirconium-based metal-organic framework / grafted sulfonated polybenzimidazole composite membrane for vanadium redox flow batteries. The proton exchange membrane comprises the following components by mass percentage: Grafted sulfonated polybenzimidazole: 93-99% MIP-202-SO3H: 1-7%
[0004] This invention also provides a method for preparing a sulfonated modified zirconium-based metal-organic framework / grafted sulfonated polybenzimidazole composite membrane for vanadium redox flow batteries, comprising the following:
[0005] Step 1: Thoroughly mix polyphosphoric acid and DAB. Then add IPA, 5-SSIPA, and P2O5 to a round-bottom flask, and pour the resulting polymer into deionized water containing sodium bicarbonate. Finally, cut the polymer into small pieces, boil, and dry to obtain sulfonated polybenzimidazole-sPBI.
[0006] Step 2: sPBI is grafted with 2-(bromomethyl)naphthalene under the catalysis of 4-dimethylaminopyridine to form grafted sulfonated polybenzimidazole-sPBI-BMN. Here, we choose a grafting degree of 5%.
[0007] Step 3: First, prepare MIP-202. First, prepare MIP-202. Add L-aspartic acid (1.4g) to a 25mL round-bottom flask, add 5mL of deionized water, and ultrasonically disperse. Next, add ZrCl4 (1.15g), add 5mL of deionized water, rinse the flask walls to remove residual reagents, and ultrasonically disperse again. After the reactants are completely dissolved, reflux at 110℃ for 12-24h. Finally, after the reaction is complete, cool to room temperature, filter, and wash repeatedly with deionized water and anhydrous ethanol. Then place in a 50℃ vacuum oven for drying, obtaining a white powder. Next, weigh 2.0g of the prepared MIP-202, disperse it in chloroform, add 2mL of 1,3-propanesulfonate lactone, treat for 24h, centrifuge to collect the solid, wash three times with water and anhydrous ethanol, and vacuum dry overnight. The resulting solid is the sulfonated modified zirconium-based metal-organic framework—MIP-202-SO3H.
[0008] Step 4: Add 5% of grafted sulfonated polybenzimidazole sPBI-BMN to DMSO. After the polymer is completely dissolved, add MIP-202-SO3H with different doping contents, mix, and sonicate until completely homogeneous. Then, pour the casting solution evenly onto a glass plate. After the solvent has completely evaporated at a certain temperature, sPBI is obtained. B5 -MS X membrane. The preferred embodiment is the sPBI. B5 -MS X The membrane was prepared by casting, and the prepared sPBI B5 -MS X The purpose of grafting and doping with MIP-202-SO3H is to (1) construct multiple proton transport channels to promote proton transfer and transport; and (2) prevent vanadium ion permeation by extending the vanadium ion transport path and using Donnan repulsion, thereby enhancing the ion selectivity of the composite membrane. The preferred embodiment is the method for preparing a sulfonated modified zirconium-based metal-organic framework / grafted sulfonated polybenzimidazole composite membrane for vanadium redox flow batteries, characterized in that the ratio of grafted sulfonated polybenzimidazole to MIP-202-SO3H is 95%:5%. Attached Figure Description
[0009] Figure 1 The preparation process of sPBI, sPBI-BMN and MIP-202-SO3H is shown below; Figure 2 Shown as sPBI, sPBI-BMN5% and sPBI B5 -MS X Infrared spectrum of the membrane; Figure 3 Shown as sPBI, sPBI-BMN5% and sPBI B5 -MS X The proton conductivity of the membrane at 30°C.
[0010] The technical solution of the present invention will be clearly and completely described below, and detailed implementation methods and specific operation processes will be given. It should be pointed out that researchers in this field can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
[0011] Example 1 includes the following steps:
[0012] 78g of polyphosphoric acid was gradually poured into a round-bottom flask at 140℃. Then, 0.015mol of DAB was added to the reaction system and mixed thoroughly. Subsequently, IPA, 5-SSIPA, and P2O5 were gradually added to the round-bottom flask. When the reactants became viscous, the temperature was raised to 200℃ at a specific rate, and the reaction was allowed to proceed for 4-5 hours. After the reaction proceeded to the top of the flask, the resulting polymer was poured into deionized water containing sodium bicarbonate to remove residual acid. The polymer was then shredded, boiled, and dried to obtain sulfonated polybenzimidazole-sPBI.
[0013] 17 mL of DMSO and 0.3 g of sPBI were added to a 50 mL round-bottom flask. After complete dissolution, a certain amount of 2-(bromomethyl)naphthalene and 4-dimethylaminopyridine were added, and the reaction was carried out at 50 °C for 12 hours. The product was poured into acetone and dried under vacuum to obtain grafted sulfonated polybenzimidazole-sPBI-BMN.
[0014] First, MIP-202 was prepared. L-Aspartic acid (1.4 g) was added to a 25 mL round-bottom flask, followed by 5 mL of deionized water and ultrasonic dispersion. Then, ZrCl4 (1.15 g) was added, along with 5 mL of deionized water, to rinse the flask walls and remove any remaining reagents. The mixture was then ultrasonically dispersed again. After complete dissolution, the mixture was refluxed at 110 °C for 12-24 h. After the reaction was complete, the mixture was cooled to room temperature, filtered, and washed multiple times with deionized water and anhydrous ethanol. The product was then dried in a 50 °C vacuum oven to obtain a white powder. Next, 2.0 g of the prepared MIP-202 was weighed, dispersed in chloroform, and treated with 2 mL of 1,3-propanesulfonate lactone for 24 h. The solid was collected by centrifugation, washed three times with water and anhydrous ethanol, and then vacuum dried overnight. The resulting solid is the sulfonated modified zirconium-based metal-organic framework—MIP-202-SO3H.
[0015] First, 0.3 g of sPBI was dissolved in DMSO. After the polymer was completely dissolved, a certain amount of 2-(bromomethyl)naphthalene and 4-dimethylaminopyridine were added. The reaction was carried out at 50 °C for 12 hours to obtain sPBI-BMN. Then, MIP-202-SO3H with different doping contents (1, 3, 5, and 7 wt%) was added, and the mixture was stirred and sonicated until completely homogeneous. The casting solution was then poured through a filter cloth onto a clean glass plate until it evenly covered the entire glass plate. The plate was then placed in an oven at 80 °C until the solvent was completely evaporated to obtain sPBI. B5 -MS X membrane.
[0016] sPBI B5 -MS X The proton conductivity of the composite membrane first increases and then decreases with increasing MIP-202-SO3H doping content. B5 The proton conductivity of -MS5 reaches 43.1 mS cm⁻¹ at 30 °C. -1 This indicates that the composite membrane can be applied to vanadium redox flow batteries.
[0017] sPBI B5 -MS X The battery performance of the composite membrane first increases and then decreases with increasing MIP-202-SO3H doping content. B5 -MS5 has a power efficiency of 60 mA / cm². -2 The high performance indicates that the composite membrane can be applied to vanadium redox flow batteries.
Claims
1. A sulfonated modified zirconium-based metal-organic framework / grafted sulfonated polybenzimidazole composite membrane for vanadium redox flow batteries, prepared from grafted sulfonated polybenzimidazole and sulfonated modified zirconium-based metal-organic framework, is further described in detail below with reference to the embodiments: 78g of polyphosphoric acid was gradually poured into a round-bottom flask at 140°C; then, 0.015mol of DAB was added to the reaction system and mixed thoroughly. Subsequently, IPA, 5-SSIPA and P2O5 were gradually added to the round-bottom flask; when the reactants became viscous, the temperature was raised to 200°C at a specific rate, and the reaction was allowed to proceed for 4-5 hours. After the reaction proceeded, the resulting polymer was poured into deionized water containing sodium bicarbonate to remove residual acid; then, the polymer was shredded, boiled and dried to obtain sulfonated polybenzimidazole-sPBI.
2. Add 17 mL of DMSO and 0.3 g of sPBI to a 50 mL round-bottom flask; after it is completely dissolved, add a certain amount of 2-(bromomethyl)naphthalene and 4-dimethylaminopyridine, and react at 50 °C for 12 hours; pour the product into acetone and dry under vacuum to obtain grafted sulfonated polybenzimidazole-sPBI-BMN.
3. First, MIP-202 was prepared. L-Aspartic acid (1.4g) was added to a 25mL round-bottom flask, and 5mL of deionized water was added for ultrasonic dispersion. Next, ZrCl4 (1.15g) was added, and 5mL of deionized water was added to rinse the flask walls to remove any remaining reagents. The mixture was then ultrasonically dispersed. After the reactants were completely dissolved, the mixture was refluxed at 110℃ for 12-24h. Finally, after the reaction was completed, the mixture was cooled to room temperature, filtered, and washed multiple times with deionized water and anhydrous ethanol. The mixture was then placed in a 50℃ vacuum oven for drying, yielding a white powder. Next, 2.0g of the prepared MIP-202 was weighed, dispersed in chloroform, and treated with 2mL of 1,3-propanesulfonate lactone for 24h. The solid was collected by centrifugation, washed three times with water and anhydrous ethanol, and then vacuum dried overnight. The resulting solid was the sulfonated modified zirconium-based metal-organic framework—MIP-202-SO3H.
4. First, dissolve 0.3g of sPBI in DMSO. After the polymer is completely dissolved, add a certain amount of 2-(bromomethyl)naphthalene and 4-dimethylaminopyridine. The reaction is carried out at 50℃ for 12 hours to obtain sPBI-BMN with an optimal grafting degree of 5%. Then, add MIP-202-SO3H with different doping contents (1, 3, 5, and 7 wt%), stir, and sonicate until completely mixed. Pour the casting solution through a filter cloth onto a clean glass plate until the casting solution evenly covers the entire glass plate. Place it in an oven at 80℃ until the solvent is completely evaporated to obtain sPBI. B5 -MSx membrane.