A high-conductivity proton exchange membrane and its preparation method
By adding free radical inhibitors to the proton exchange membrane, the problems of complex and high cost in the prior art are solved, and the proton exchange membrane conductivity and acid absorption rate are significantly improved.
Patent Information
- Application Number
- CN202510387153.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2045-03-31
AI Technical Summary
The prior art has problems with high preparation process requirements and high cost in improving the proton conductivity of the proton exchange membrane, and the existing methods are difficult to effectively improve the hydrophilic phase region continuity of the membrane material.
Using the method of adding different types of radical inhibitors, a high-conductivity proton exchange membrane was prepared through ultrasonic reaction and drying membrane treatment, which improved the continuity of the hydrophilic phase region of the membrane material.
The conductivity of the proton exchange membrane has been significantly improved, with simple operation and low cost, and the acid absorption and swelling rate of the membrane material has been improved.
Smart Images
Figure CN119905622B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of membrane preparation, and more precisely, it relates to a high-conductivity proton exchange membrane and a preparation method thereof. Background Art
[0002] Proton exchange membrane fuel cells have the advantages of being pollution-free, having high energy conversion efficiency, fast startup speed, simple structure, convenient operation and maintenance, etc., and are new energy devices that have received much attention in recent years. The proton exchange membrane is a key component of proton exchange membrane fuel cells, and it has a significant impact on the actual performance of the battery during operation.
[0003] Currently, the research direction of proton exchange membranes is mainly to balance the problems between proton conductivity and chemical stability, and the permeability of active substances such as fuels. It can mainly be achieved through structural modification, blending modification, surface modification, and hybrid / composite modification by introducing functional dopants of proton-conducting polymer molecules. Proton conductivity is one of the most critical properties of proton exchange membranes. Improving the proton conductivity of proton exchange membranes can effectively improve the performance of proton exchange membrane fuel cells.
[0004] Some studies have shown that the formation of larger hydrophilic proton-conducting phase regions in proton membranes is beneficial to the improvement of the conductivity of proton exchange membranes. The prior art compared the performance of polysulfone membranes with fluorinated alkylsulfonic acid side chains of different graft chain lengths, branched and unbranched. The stronger the acidity and the longer the graft chain, the easier it is for the hydrophilic side chains with branched structures to aggregate to form larger hydrophilic proton-conducting phase regions, and the higher the proton conductivity of the prepared proton exchange membrane. The prior art has disclosed ABA-type block matrix proton exchange membranes with polystyrene at both ends and sulfonated polyphenylene sulfide sulfone in the middle section. As the volume fraction of the middle section increases, the microphase separation structure of the proton exchange membrane changes from spheres to cylinders and then to layers. The proton conductivity of the membrane is significantly improved with the increase in the continuity of the hydrophilic phase region. Although the prior art can well improve the conductivity of membrane materials, it has relatively high requirements for the preparation process of membrane materials, relatively harsh reaction conditions, and high production costs. Summary of the Invention
[0005] The object of the present invention is to propose a high-conductivity proton exchange membrane and a preparation method thereof in view of the deficiencies of the prior art.
[0006] In the first aspect, a preparation method of a high-conductivity proton exchange membrane includes:
[0007] Step 1: Place the polymer material in an organic solvent and ultrasonically dissolve it until completely dissolved to prepare a 1-10 wt% polymer solution; the polymer material contains bromomethyl or chloromethyl;
[0008] Step 2: Add a quaternization reagent to the polymer solution and perform an ultrasonic reaction at 30 - 80 °C for 5 - 180 min;
[0009] Step 3: Add a radical inhibitor to the solution obtained in Step 2. The polymer material includes bromomethyl or chloromethyl; and stir at room temperature for 10 - 120 min to obtain a casting solution;
[0010] Step 4: Pour the casting solution into a super-flat petri dish and place it in an oven. Bake the film at 45 - 80 °C for 24 - 60 h to complete the preparation of the proton exchange membrane.
[0011] Preferably, in Step 1, the polymer material is any one of polyphenylene oxide bromide and poly(p-chloromethylstyrene - styrene).
[0012] Preferably, in Step 1, the organic solvent is at least one of N-methylpyrrolidone, N,N-dimethylacetamide, and N,N-dimethylformamide.
[0013] Preferably, in Step 2, the quaternization reagent is triethylamine.
[0014] Preferably, in Step 3, the radical inhibitor is a phenolic reagent, a ketone reagent, or an amine reagent. The phenolic reagent is 4-tert-butylphenol; the ketone reagent includes benzophenone; the amine reagent is N-phenyl-1-naphthylamine or diphenylamine sulfide.
[0015] In a second aspect, a high-conductivity proton exchange membrane prepared by the method according to any one of the first aspect is provided.
[0016] The beneficial effects of the present invention are as follows:
[0017] 1. The present invention uses a method of adding different types of radical inhibitors to improve the acid absorption rate of the proton exchange membrane, thereby improving the continuity of the hydrophilic phase region in the proton exchange membrane material, and further obtaining the effect of improving the conductivity of the proton exchange membrane material, providing a new path for improving the performance of the proton exchange membrane.
[0018] 2. The method provided by the present invention for adding a radical inhibitor to improve the conductivity of the proton membrane is simple and convenient to operate, has low requirements for instruments, and has a short reaction time.
[0019] 3. The radical inhibitor materials used in the present invention are inexpensive, rich in variety, small in dosage, and can effectively improve the conductivity of the proton exchange membrane. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a flowchart for the preparation of a quaternized polyphenylene oxide membrane material;
[0021] Figure 2The graph of the conductivity of proton membranes doped with different radical inhibitors varying with temperature;
[0022] Figure 3 The AFM images of proton exchange membranes doped and undoped with 4-tert-butylphenol. Detailed implementation manners
[0023] The following further describes the present invention in conjunction with embodiments. The descriptions of the following embodiments are only for helping to understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
[0024] Embodiment 1:
[0025] To solve the problems of the prior art, in Embodiment 1 of the present application, a simple and low-cost method is adopted to improve the continuity of the hydrophilic phase region in the proton exchange membrane material, thereby improving the conductivity of the proton exchange membrane.
[0026] Specifically, a preparation method of a high-conductivity proton exchange membrane includes:
[0027] Weigh 1.5 g of brominated polyphenylene oxide, add it to a mixed solution of 10 mL of N-methylpyrrolidone (NMP) and 25 mL of N,N-dimethylacetamide (DMAc), ultrasonically dissolve it, then add 475 μL of triethylamine, and ultrasonically react at 30 °C for 3 h. Divide the obtained solution into five equal parts, one part without adding substances, and the other 4 parts are respectively added with 4 different radical inhibitors to obtain five different casting solutions. Among them, the 4 different radical inhibitors include: 4-tert-butylphenol (4-TBP), benzophenone (BP), N-phenyl-1-naphthylamine (PNA), and diphenylamine sulfide (PTZ). The amount of substance of the radical inhibitor is 0.24 times the amount of substance of bromomethyl in brominated polyphenylene oxide (0.3 g). Stir the 5 casting solutions at room temperature for 10 min simultaneously, pour them into a super-flat petri dish, and dry the film in an oven at 80 °C for 48 h to obtain QPPO 0.75 and QPPO 0.75 -R 0.24 proton exchange membranes (where R represents the type of radical inhibitor added). Figure 1 Shows the preparation flow chart of quaternized polyphenylene oxide membrane materials with 4-tert-butylphenol, benzophenone, N-phenyl-1-naphthylamine, and diphenylamine sulfide as additive components.
[0028] The measurement method of the acid absorption performance of the proton exchange membrane includes:
[0029] The prepared proton exchange membrane was cut into rectangles of a certain size, placed in an oven and dried to a constant weight. Its mass was weighed with an electronic balance and recorded as m0 (g), and its length (cm), width (cm), and thickness (cm) were measured. Then the membrane was soaked in an 85 wt% phosphoric acid aqueous solution and placed in an oven at a certain temperature for 24 h. The membrane material was taken out and quickly dried with filter paper, and its mass was weighed and recorded as m e (g), and its length, width, and thickness were measured. The phosphoric acid doping level of the membrane can be calculated according to the following formula:
[0030]
[0031] If the area and volume of the dry membrane before phosphoric acid absorption are recorded as A0 and V0 respectively, and the area at 24 h of phosphoric acid adsorption is A e and V e , the area swelling ratio (AS) and volume swelling ratio (VS) of the membrane can be obtained from the following formula:
[0032]
[0033]
[0034] Among them, is the area swelling ratio, is the volume swelling ratio.
[0035] The specific analysis of the acid absorption performance and conductivity of the proton exchange membrane is as follows:
[0036] The acid absorption rate, area and volume swelling ratio, and conductivity at 180 °C of the prepared membrane materials are shown in Table 1. It can be seen from the table that adding different types of radical inhibitors to the proton exchange membrane will increase the acid absorption rate, area, and volume swelling ratio of the proton exchange membrane to varying degrees. Figure 2 is the graph of the conductivity of the prepared membrane material changing with temperature. It can be seen from Figure 2 that after doping with radical inhibitors, the conductivity of the proton membrane increases to varying degrees. Among them, when 4-TBP is added, the conductivity of the proton membrane increases most significantly. At 180 °C, the conductivity of the proton exchange membrane doped with radical inhibitors is 2.2 times that of the proton membrane without doping radical inhibitors. The membrane material was characterized by AFM (as shown in Figure 3 ). It can be seen from the figure that after doping with radical inhibitors, the continuity of the hydrophilic phase region of the membrane material increases significantly. Figure 3 In (a) corresponds to the membrane material QPPO 0.75 , without doping 4-tert-butylphenol; Figure 3 In (b) corresponds to the membrane material QPPO 0.75 -4-TBP 0.12 ; Figure 3In (c), the corresponding membrane material is QPPO 0.75 -4-TBP 0.24 Among them, the membrane material QPPO x -4-TBP y where x represents that the amount of substance of triethylamine during the reaction feed is x times the amount of substance of bromomethyl in polyphenylene oxide bromide, and y represents that the amount of substance of 4-TBP during the reaction feed is y times the amount of substance of bromomethyl in polyphenylene oxide bromide.
[0037] Table 1 Changes in conductivity, acid uptake rate, and swelling of proton exchange membranes doped with different types of radical inhibitors
[0038]
[0039] Example 2:
[0040] On the basis of Example 1, Example 2 of the present application provides another preparation method of a high-conductivity proton exchange membrane, including:
[0041] Weigh 0.6 g of poly(p-chloromethylstyrene-styrene) copolymer, add it to a mixed solution of 4 mL of N-methylpyrrolidone (NMP) and 16 mL of N,N-dimethylacetamide (DMAc), and ultrasonicate until dissolved. Then add 2 mL of triethylamine and react under ultrasonic conditions at 60 °C for 2 h. Divide the obtained solution into two equal parts. Add 4-tert-butylphenol to one part, and the amount of substance added is 1.5 times the amount of substance of chloromethyl in poly(p-chloromethylstyrene-styrene) copolymer. Do not add any substance to the other part as a blank control group. Stir the two parts simultaneously at room temperature for 30 min to obtain two different casting solutions. Pour them into a super-flat petri dish and dry the film in an oven at 60 °C for 48 h to obtain QP(VBC-St) and QP(VBC-St)-4-TBP proton exchange membranes.
[0042] The measurement steps for the acid uptake performance of the proton exchange membrane can refer to Example 1, and will not be elaborated here in the present application.
[0043] The acid uptake performance and conductivity of the proton exchange membrane are shown in Table 2.
[0044] Table 2 Acid uptake performance and conductivity of proton exchange membranes
[0045]
[0046] As can be seen from Table 2, after doping with 4-TBP radical inhibitor, the acid uptake rate, area and volume swelling rate, and conductivity at 180 °C of the QP(VBC-St) proton exchange membrane have all increased significantly.
[0047] Example 3:
[0048] On the basis of Example 1, Example 2 of the present application provides another method for preparing a high-conductivity proton exchange membrane, including:
[0049] Weigh 0.6 g of brominated polyphenylene oxide and add it to a mixed solution of 2 mL of N-methylpyrrolidone (NMP) and 10 mL of N,N-dimethylformamide (DMF). Ultrasonic until dissolved, then add 90 mL of triethylamine and react under ultrasonic conditions at 30 °C for 2 h. Divide the obtained solution into two equal parts. Add benzophenone to one part, and the amount of substance added is 1.5 times the amount of bromomethyl in the brominated polyphenylene oxide. Do not add any substance to the other part as a blank control group. Stir the two parts simultaneously at room temperature for 10 min to obtain two different casting solutions. Pour them into a super-flat petri dish and dry the film in an oven at 70 °C for 36 h to obtain QPPO 0.7 and QPPO 0.7 -BP proton exchange membrane.
[0050] The steps for measuring the acid absorption performance of the proton exchange membrane can refer to Example 1, and will not be elaborated herein.
[0051] The acid absorption performance and conductivity of the proton exchange membrane are shown in Table 3.
[0052] Table 3 Acid absorption performance and conductivity of proton exchange membrane
[0053]
[0054] Example 4:
[0055] On the basis of Example 1, Example 4 of the present application provides another method for preparing a high-conductivity proton exchange membrane, including:
[0056] Weigh 0.6 g of poly(p-chloromethylstyrene-styrene) copolymer and add it to 20 mL of N,N-dimethylacetamide (DMAc). Ultrasonic until dissolved, then add 1 mL of triethylamine and react under ultrasonic conditions at 80 °C for 3 h. Divide the obtained solution into two equal parts. Add benzophenone to one part, and the amount of substance added is 1.5 times the amount of chloromethyl in the poly(p-chloromethylstyrene-styrene) copolymer. Do not add any substance to the other part as a blank control group. Stir the two parts simultaneously at room temperature for 20 min to obtain two different casting solutions. Pour them into a super-flat petri dish and dry the film in an oven at 60 °C for 48 h to obtain QP(VBC-St) and QP(VBC-St)-BP proton exchange membranes.
[0057] The steps for measuring the acid absorption performance of the proton exchange membrane can refer to Example 1, and will not be elaborated herein.
[0058] The acid absorption performance and conductivity of the proton exchange membrane are shown in Table 4.
[0059] Table 4 Acid Absorption Performance and Conductivity of Proton Exchange Membrane
[0060]
[0061] As can be seen from Table 4, QPPO 0.7 After the proton exchange membrane is doped with the BP radical inhibitor, the acid absorption rate, area and volume swelling rate of the membrane material, and the conductivity at 180 °C all increase significantly.
[0062] Example 5:
[0063] On the basis of Example 1, Example 5 of the present application provides another method for preparing a high-conductivity proton exchange membrane, including:
[0064] According to the ratio of adding 0.6 g of brominated polyphenylene oxide to a mixed solution of 4 mL of N-methylpyrrolidone (NMP) and 5 mL of N,N-dimethylacetamide (DMAc), ultrasonically dissolve it, and prepare 5 solutions respectively. Add triethylamine in an amount of 100%, 90%, 80%, 75% and 70% of the amount of bromomethyl in brominated polyphenylene oxide (calculated based on 0.6 g of brominated polyphenylene oxide) to the 5 solutions respectively, and ultrasonically react at 60 °C for 3 h. Divide each solution into 2 equal parts, one part without any substance, and the other part with 4-TBP added. The amount of the radical inhibitor is 0.24 times the amount of bromomethyl in brominated polyphenylene oxide (calculated based on 0.3 g). Stir the solutions at room temperature for 10 min to obtain ten different casting solutions, pour them into a super-flat petri dish, and dry the film in an oven at 80 °C for 48 h to obtain QPPO1 1.0 、QPPO1 1.0 -4-TBP 0.24 、QPPO 0.9 、QPPO 0.9 -4-TBP 0.24 、QPPO 0.8 、QPPO 0.8 -4-TBP 0.24 、QPPO 0.75 、QPPO 0.75 -4-TBP 0.24 、QPPO 0.7 、QPPO 0.7 -4-TBP 0.24 。
[0065] The measurement steps of the acid absorption performance of the proton exchange membrane can refer to Example 1, and will not be elaborated here in the present application.
[0066] The acid absorption performance and swelling performance of the proton exchange membrane are shown in Table 5.
[0067] Table 5 Changes in acid absorption amount and area-volume swelling rate of QPPO membrane materials with different degrees of quaternization before and after doping with the same amount of 4-tert-butylphenol
[0068]
[0069] The acid absorption rate and area-volume swelling rate of the prepared membrane materials are shown in Table 5. As can be seen from Table 5, after adding 4-TBP to the proton exchange membrane, the acid absorption rate, area, and volume swelling rate of the proton exchange membrane can be improved to varying degrees. Among them, for the proton exchange membrane with a high degree of quaternization, the addition of 4-TBP has a more significant effect on improving the conductivity.
Claims
1. Application of a high-conductivity proton exchange membrane in a fuel cell, characterized in that, The preparation method of the high-conductivity proton exchange membrane includes: Step 1: Place the polymer material in an organic solvent and ultrasonically dissolve it until completely dissolved to prepare a 1-10 wt% polymer solution; the polymer material contains bromomethyl or chloromethyl; Step 2: Add a quaternization reagent to the polymer solution and ultrasonically react at 30-80 °C for 5-180 min; Step 3: Add a radical inhibitor to the solution obtained in Step 2, and the amount of substance of the radical inhibitor is 0.24-1.5 times the amount of substance of bromomethyl or chloromethyl in the polymer material, and stir at room temperature for 10-120 min to obtain a casting solution; the radical inhibitor is used to increase the conductivity of the proton exchange membrane; the radical inhibitor is a phenolic reagent, a ketone reagent or an amine reagent; Step 4: Pour the casting solution into a super-flat petri dish and place it in an oven to dry the membrane at 45-80 °C for 24-60 h to complete the preparation of the proton exchange membrane.
2. Use of the high-conductivity proton exchange membrane according to claim 1 in a fuel cell, characterized in that, In Step 1, the polymer material is any one of brominated polyphenylene ether and poly(p-chloromethylstyrene-styrene).
3. Use of the high-conductivity proton exchange membrane according to claim 2 in a fuel cell, characterized in that, In Step 1, the organic solvent is at least one of N-methylpyrrolidone, N,N-dimethylacetamide and N,N-dimethylformamide.
4. Use of the high-conductivity proton exchange membrane according to claim 3 in a fuel cell, characterized in that, In Step 2, the quaternization reagent is triethylamine.
5. The application of the high-conductivity proton exchange membrane according to claim 4 in a fuel cell, characterized in that, In Step 3, the phenolic reagent is 4-tert-butylphenol; the ketone reagent includes benzophenone; the amine reagent is N-phenyl-1-naphthylamine or diphenylamine sulfide.