Modified mxene-sulfonated polysulfone composite material and preparation method and application thereof

Abstract

The application relates to the technical field of proton exchange membrane fuel cells, and particularly discloses a modified MXene-sulfonated polysulfone composite material as well as a preparation method and application thereof. The modified MXene-sulfonated polysulfone composite material comprises sulfonated polysulfone and proton acid modified MXene assembled on the sulfonated polysulfone molecules through intermolecular hydrogen bonds; wherein the proton acid is a proton acid containing sulfonic acid groups or carboxyl groups. The modified MXene-sulfonated polysulfone composite material provided by the application has high proton conductivity, low fuel permeability and excellent stability, the proton exchange capacity can reach more than 1.0 mmol / g, the proton conductivity can reach more than 0.078 S / cm, the methanol permeability is 9.4*10-7 cm / s, and the like. ‑ 7 cm 2 ·s ‑1 The application has broad application prospects in the field of proton exchange membrane fuel cells.

Description

Technical Field

[0001] This invention relates to the field of proton exchange membrane fuel cell technology, and in particular to a modified MXene-sulfonated polysulfone composite material, its preparation method, and its application. Background Technology

[0002] A proton exchange membrane fuel cell (PEMFC) is an energy conversion device that directly converts chemical energy into electrical energy. As long as an oxidant and reductant are continuously supplied, it can continuously output electrical energy. It has advantages such as high energy efficiency, good tolerance to CO, and a relatively simple hydrothermal management system. The proton exchange membrane is one of the key components of a PEMFC; it acts as an ion conductor and shields the cross-linking of fuel and electrons from the anode to the cathode. Currently, Nafion is used as the proton exchange membrane due to its excellent stability and conductivity. However, under high temperature conditions (>120°C), Nafion experiences a sharp decrease in proton conductivity due to water loss, limiting the battery's efficiency and thus restricting its commercial application.

[0003] Non-fluorinated proton exchange membranes (PEMs) are a relatively new technology proposed in recent years to replace Nafion series PEMs. Sulfonated polymers with rigid main-chain structures, such as sulfonated polyether ether ketones, sulfonated polysulfones, and sulfonated polyimides, have attracted considerable attention. However, the main problem with current non-fluorinated PEMs is the difficulty in forming microphase separation structures within their systems. Dead zones easily form between hydrophilic and hydrophobic phases, resulting in poor proton conductivity. To construct microphase separation structures within non-fluorinated PEM systems, current methods generally involve blending other positively charged or weakly positively charged compounds with sulfonic acid groups to form acid-base ion pairs, reducing proton exchange losses caused by dehydration at high temperatures. However, PEMs require high membrane homogeneity; therefore, the compatibility of the blended materials with the matrix materials is also a crucial consideration. In addition, PEMs also have high requirements for proton conductivity and gas permeability barrier properties. Therefore, how to prepare non-fluorinated proton exchange membranes with high proton exchange capacity, proton conductivity, and fuel barrier properties to improve the overall performance of fuel cells has become an urgent problem to be solved. Summary of the Invention

[0004] To address the shortcomings of existing non-fluorinated proton exchange membranes in terms of proton exchange capacity, conductivity, and fuel barrier properties, this invention provides a modified MXene-sulfonated polysulfone composite material, its preparation method, and its applications.

[0005] To solve the above-mentioned technical problems, the technical solution 1 provided by the embodiments of the present invention is:

[0006] A modified MXene-sulfonated polysulfone composite material comprising sulfonated polysulfone to modify MXene by means of intermolecular hydrogen bonding on the sulfonated polysulfone molecules;

[0007] Wherein, the modified MXene is a protonic acid-modified MXene, and the protonic acid is a protonic acid containing a sulfonic acid group or a carboxyl group.

[0008] Compared to existing technologies, the modified MXene-sulfonated polysulfone composite material provided by this invention introduces MXene material into the sulfonated polysulfone matrix. The layered structure of MXene can construct continuous proton transport channels within the sulfonated polysulfone film, improving proton conductivity. Furthermore, this invention utilizes the abundant hydroxyl groups on the surface of MXene and modifies MXene through the dehydration condensation of protic acids and hydroxyl groups, introducing alkyl sulfonic acid groups or alkyl carboxylic acid groups into the MXene molecular structure. The modified MXene not only has better compatibility with polysulfone but can also be well dispersed within the sulfonated polysulfone matrix. In addition to enhancing the stability of the proton exchange membrane, the addition of proton groups in sulfonated polysulfone is crucial. Furthermore, the sulfonic acid or carboxyl groups in MXene form a continuous proton transport network with the sulfonic acid groups in sulfonated polysulfone through hydrogen bonds, significantly improving the proton conductivity of sulfonated polysulfone. Moreover, the introduction of modified MXene containing alkyl sulfonic acid or alkyl carboxylic acid into the sulfonated polysulfone molecular chain through hydrogen bonds increases the stacking density of the sulfonated polysulfone molecular chain, making the molecular chain more compact and effectively improving the fuel barrier properties of the proton exchange membrane. This has broad application prospects in the field of proton exchange membrane fuel cells.

[0009] Further, the protic acid is at least one selected from 1,3-propanesulfonic acid lactone, 1,4-butanesulfonic acid lactone, succinic anhydride, maleic anhydride, oxalic acid, or phthalic acid.

[0010] Taking 1,4-butyryl lactone as an example, the reaction equation is as follows:

[0011]

[0012] Taking succinic anhydride as an example, the reaction equation is as follows:

[0013]

[0014] Modifying MXene with a preferred protic acid can enhance the compatibility between MXene and sulfonated polysulfone, increase the density of the molecular chain stacking of sulfonated polysulfone, and increase the proton density in sulfonated polysulfone, thereby significantly improving the proton conductivity, fuel barrier properties, and mechanical stability of sulfonated polysulfone membranes.

[0015] Furthermore, the method for preparing the modified MXene includes the following steps:

[0016] MXene was dispersed in a polar solvent to obtain an MXene dispersion;

[0017] The protic acid was added to the MXene dispersion, mixed evenly, stirred and reacted, separated into solid and liquid components, and dried to obtain the modified MXene.

[0018] In conjunction with the above, the polar solvent is further defined as at least one of water, methanol, ethanol, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, or dimethyl sulfoxide.

[0019] In conjunction with the above, the concentration of the MXene dispersion is further described as 0.1 wt% - 1 wt%.

[0020] In conjunction with the above, the mass ratio of MXene to protic acid is further 1:0.1-10.

[0021] In conjunction with the above, the temperature of the stirring reaction is 50℃-100℃, and the reaction time is 0.5h-5h.

[0022] For example, the above solid-liquid separation can be achieved by centrifugal separation or vacuum filtration separation.

[0023] The above modification method can enable the hydroxyl groups in MXene to react fully with the protic acid, thereby increasing the content of sulfonic acid groups or carboxyl groups in MXene.

[0024] Secondly, the present invention also provides a method for preparing a modified MXene-sulfonated polysulfone composite material, comprising the following steps:

[0025] Step 1: Disperse the modified MXene in an organic solvent to obtain a modified MXene dispersion;

[0026] Step 2: Add the sulfonated polysulfone monomer to the modified MXene dispersion, mix evenly, add the catalyst and dehydrating agent, heat to carry out dehydration reaction, remove the dehydrating agent after the reaction is completed, react at 160℃-200℃ for 6h-48h, separate the solid and liquid, wash, dry to obtain the modified MXene-sulfonated polysulfone composite material.

[0027] Taking 1,4-butyryl lactone as an example, the reaction equation is as follows:

[0028]

[0029] Taking succinic anhydride as an example, the reaction equation is as follows:

[0030]

[0031] Compared with the prior art, the preparation method of the modified MXene-sulfonated polysulfone composite material provided by the present invention involves in-situ assembly of proton acid-modified MXene and sulfonated polysulfone. That is, the modified MXene is assembled at the same time as the sulfonated polysulfone is synthesized. This facilitates the combination of MXene and sulfonated polysulfone, thereby improving the uniformity of MXene in sulfonated polysulfone and avoiding the problem of performance degradation of sulfonated polysulfone material caused by direct incorporation of MXene. Through the synergistic effect of modified MXene and sulfonated polysulfone, the purpose of simultaneously improving proton conductivity, fuel barrier properties and stability is achieved.

[0032] As a specific embodiment of the present invention, the MXene can be prepared by the following method:

[0033] MAX phase Ti3AlC2 powder was dispersed in an etching solution, heated and stirred, centrifuged, and dried to obtain MXene.

[0034] Furthermore, the etching solution is at least one of hydrofluoric acid, sodium fluoride-hydrochloric acid mixed solution, or lithium fluoride-hydrochloric acid mixed solution, and the fluoride ion concentration in each solution is 1 mol / L-10 mol / L.

[0035] Furthermore, the mass ratio of the Ti3AlC2 powder to the etching solution is 1:5-30.

[0036] Furthermore, the heating and stirring temperature is 0℃-70℃, and the time is 0.5h-24h.

[0037] Furthermore, the centrifugation speed is 1000rpm-10000rpm, and the centrifugation time is 1min-30min.

[0038] Furthermore, in step one, the concentration of the modified MXene dispersion is 0.04wt%-2wt%.

[0039] Further, in step one, the sulfonated polysulfone monomer is 4,4'-dihydroxydiphenyl sulfone, 4,4'-dichlorodiphenyl sulfone, and 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid.

[0040] Preferably, the molar ratio of 4,4'-dihydroxydiphenyl sulfone to the total amount of 4,4'-dichlorodiphenyl sulfone and 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid is 1:1, wherein the molar ratio of 4,4'-dichlorodiphenyl sulfone to 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid is 1:0.1-3.

[0041] It should be noted that the aforementioned 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid can be in sulfonic acid form or in sodium sulfonate form, with 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid being preferred. 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid can be prepared from commercially available disodium 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid via ion exchange resin.

[0042] Further, in step one, the organic solvent is at least one of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or sulfolane.

[0043] Furthermore, in step two, the mass ratio of the sulfonated polysulfone monomer to the modified MXene is 1-100:0.1.

[0044] Furthermore, in step two, the catalyst is potassium carbonate, and the dehydrating agent is toluene.

[0045] Furthermore, in step two, the temperature of the dehydration reaction is 100℃-120℃, and the dehydration time is 1h-6h.

[0046] It should be noted that after the reaction in step two is completed, the reaction solution is poured into water or alcohol solvent, and then solid-liquid separation is performed.

[0047] The alcohols mentioned above are preferably methanol or ethanol.

[0048] The method for preparing modified MXene-sulfonated polysulfone composite material provided by this invention uses readily available raw materials, has a simple process, and produces a modified MXene-sulfonated polysulfone composite material with good uniformity and low cost. It is easy to achieve large-scale production of MXene-sulfonated polysulfone composite material, and the prepared modified MXene-sulfonated polysulfone composite material has good proton conductivity and excellent fuel barrier properties. It can effectively replace Nafion series proton exchange membranes and has broad application prospects in the field of fuel cells.

[0049] Thirdly, the present invention also provides the application of the above-mentioned modified MXene-sulfonated polysulfone composite material in proton exchange membrane fuel cells.

[0050] A proton exchange membrane comprising the above-described modified MXene-sulfonated polysulfone composite material.

[0051] For example, the method for preparing the above-mentioned proton exchange membrane includes the following steps:

[0052] The modified MXene-sulfonated polysulfone composite material was dispersed in a solvent, then poured into a polytetrafluoroethylene mold and dried to obtain a proton exchange membrane.

[0053] As a specific embodiment of the present invention, the solvent mentioned above can be N-methylpyrrolidone, with a concentration of 8wt%-12wt%.

[0054] Specifically, the drying temperature is 90℃-110℃, and the drying time is 20h-25h.

[0055] A fuel cell membrane electrode assembly includes the proton exchange membrane described above.

[0056] A proton exchange membrane fuel cell includes the aforementioned fuel cell membrane electrode assembly.

[0057] The modified MXene-sulfonated polysulfone composite material provided by this invention exhibits high proton conductivity, low fuel permeability, and excellent stability. Its proton exchange capacity can reach over 1.0 mmol / g, proton conductivity can reach over 0.078 S / cm, and methanol permeability is 9.4 × 10⁻⁶. -7 cm 2 ·s -1 The following has broad application prospects in the field of proton exchange membrane fuel cells. Attached Figure Description

[0058] Figure 1 This is a SEM image of the modified MXene-sulfonated polysulfone composite material prepared in Example 1 of this invention;

[0059] Figure 2 This is a SEM image of the MXene-sulfonated polysulfone composite material prepared in Comparative Example 2 of this invention;

[0060] Figure 3 This is a schematic diagram of an H-type electrolytic cell used to test methanol permeability in an embodiment of the present invention. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0062] To better illustrate the present invention, further examples are provided below.

[0063] The MXene used in the following examples and comparative examples was prepared by the following method:

[0064] Ti3AlC2 was dispersed in 10 times its mass of a 3 mol / L hydrofluoric acid solution, heated to 50°C and stirred for 8 hours, centrifuged, washed, and dried to obtain MXene.

[0065] Example 1

[0066] This invention provides a method for preparing a modified MXene-sulfonated polysulfone composite material, comprising the following steps:

[0067] S1, 0.06 g MXene and 20 mL N-methylpyrrolidone were added to a three-necked flask and sonicated at 10 Hz and 100 W for 0.5 h to obtain an MXene dispersion;

[0068] S2, 0.2 g of 1,4-butyryl lactone was added to the above MXene dispersion, heated to 60°C, and reacted for 0.5 h. The reaction solution was poured into deionized water, filtered, washed with water, and dried to obtain modified MXene.

[0069] S3, the modified MXene obtained above and 260 mL of N-methylpyrrolidone were added to a three-necked flask and ultrasonically treated at 10 Hz and 100 W for 0.5 h to obtain a modified MXene dispersion;

[0070] S4, 5.0 g of 4,4'-dihydroxydiphenyl sulfone, 4.2 g of 4,4'-dichlorodiphenyl sulfone, and 2.6 g of 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid were added to the above modified MXene dispersion, followed by the addition of 3.0 g of K2CO3 and 50 mL of toluene. The mixture was dehydrated at 110 °C for 3 h, then the toluene was removed, the temperature was raised to 180 °C, and the reaction was carried out for 10 h. The reaction solution was poured into deionized water, filtered, washed with water, and dried to obtain the modified MXene-sulfonated polysulfone composite material.

[0071] The SEM image of the modified MXene-sulfonated polysulfone composite material prepared in this embodiment is shown below. Figure 1 As shown.

[0072] Example 2

[0073] This invention provides a method for preparing a modified MXene-sulfonated polysulfone composite material, comprising the following steps:

[0074] S1, 0.12g MXene and 20mL N-methylpyrrolidone were added to a three-necked flask and sonicated at 10Hz and 100W for 0.5h to obtain an MXene dispersion;

[0075] S2, add 0.3g of maleic anhydride to the above MXene dispersion, heat to 60℃, react for 5h, pour the reaction solution into deionized water, filter, wash with water, and dry to obtain modified MXene;

[0076] S3, the modified MXene obtained above and 300 mL of N-methylpyrrolidone were added to a three-necked flask and ultrasonically treated at 10 Hz and 100 W for 0.5 h to obtain a modified MXene dispersion;

[0077] S4, 5.0 g of 4,4'-dihydroxydiphenyl sulfone, 4.2 g of 4,4'-dichlorodiphenyl sulfone, and 2.6 g of 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid were added to the above modified MXene dispersion, followed by the addition of 3.0 g of K2CO3 and 50 mL of toluene. The mixture was dehydrated at 110 °C for 3 h, then the toluene was removed, and the temperature was raised to 200 °C for 6 h. The reaction solution was poured into deionized water, filtered, washed with water, and dried to obtain the modified MXene-sulfonated polysulfone composite material.

[0078] Example 3

[0079] This invention provides a method for preparing a modified MXene-sulfonated polysulfone composite material, comprising the following steps:

[0080] S1, 0.12 g MXene and 12 mL N,N-dimethylformamide were added to a three-necked flask and sonicated at 10 Hz and 100 W for 0.5 h to obtain an MXene dispersion;

[0081] S2, 0.012 g of 1,3-propanesulfonic acid lactone was added to the above MXene dispersion, heated to 80°C, and reacted for 3 h. The reaction solution was poured into deionized water, filtered, washed with water, and dried to obtain modified MXene.

[0082] S3, the modified MXene obtained above and 300 mL of N,N-dimethylformamide were added to a three-necked flask and sonicated at 10 Hz and 100 W for 0.5 h to obtain a modified MXene dispersion;

[0083] S4, 5.0 g of 4,4'-dihydroxydiphenyl sulfone, 4.2 g of 4,4'-dichlorodiphenyl sulfone, and 2.6 g of 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid were added to the above modified MXene dispersion, followed by the addition of 3.0 g of K2CO3 and 50 mL of toluene. The mixture was dehydrated at 110 °C for 3 h, then the toluene was removed, the temperature was raised to 170 °C, and the reaction was carried out for 10 h. The reaction solution was poured into deionized water, filtered, washed with water, and dried to obtain the modified MXene-sulfonated polysulfone composite material.

[0084] Example 4

[0085] This invention provides a method for preparing a modified MXene-sulfonated polysulfone composite material, comprising the following steps:

[0086] S1, 0.12 g MXene and 120 mL dimethyl sulfoxide were added to a three-necked flask and sonicated at 10 Hz and 100 W for 0.5 h to obtain an MXene dispersion;

[0087] S2, 0.6 g of succinic anhydride was added to the above MXene dispersion, heated to 70 °C, and reacted for 4 h. The reaction solution was poured into deionized water, filtered, washed with water, and dried to obtain modified MXene.

[0088] S3, the modified MXene obtained above and 400 mL of dimethyl sulfoxide were added to a three-necked flask and ultrasonically treated at 10 Hz and 100 W for 0.5 h to obtain a modified MXene dispersion;

[0089] S4, 5.0 g of 4,4'-dihydroxydiphenyl sulfone, 4.2 g of 4,4'-dichlorodiphenyl sulfone, and 2.6 g of 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid were added to the above modified MXene dispersion, followed by the addition of 3.0 g of K2CO3 and 50 mL of toluene. The mixture was dehydrated at 110 °C for 3 h, then the toluene was removed, and the temperature was raised to 180 °C for 48 h. The reaction solution was poured into deionized water, filtered, washed with water, and dried to obtain the modified MXene-sulfonated polysulfone composite material.

[0090] Example 5

[0091] This invention provides a method for preparing a modified MXene-sulfonated polysulfone composite material, comprising the following steps:

[0092] S1, 0.12 g MXene and 30 mL N,N-dimethylacetamide were added to a three-necked flask and sonicated at 10 Hz and 100 W for 0.5 h to obtain an MXene dispersion;

[0093] S2, 1.2g of oxalic acid was added to the above MXene dispersion, heated to 100℃, and reacted for 0.5h. The reaction solution was poured into deionized water, filtered, washed with water, and dried to obtain modified MXene.

[0094] S3, the modified MXene obtained above and 650 mL of N,N-dimethylacetamide were added to a three-necked flask and sonicated at 10 Hz and 100 W for 0.5 h to obtain a modified MXene dispersion;

[0095] S4, 5.0 g of 4,4'-dihydroxydiphenyl sulfone, 4.2 g of 4,4'-dichlorodiphenyl sulfone, and 2.6 g of 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid were added to the above modified MXene dispersion, followed by the addition of 3.0 g of K2CO3 and 50 mL of toluene. The mixture was dehydrated at 110 °C for 3 h, then the toluene was removed, the temperature was raised to 190 °C, and the reaction was carried out for 10 h. The reaction solution was poured into deionized water, filtered, washed with water, and dried to obtain the modified MXene-sulfonated polysulfone composite material.

[0096] Comparative Example 1

[0097] This comparative example provides a method for preparing sulfonated polysulfone, comprising the following steps:

[0098] S1, 5.0 g of 4,4'-dihydroxydiphenyl sulfone, 4.2 g of 4,4'-dichlorodiphenyl sulfone, and 2.6 g of 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid were dissolved in 260 mL of N-methylpyrrolidone and 50 mL of toluene. Then, 3.0 g of K2CO3 was added, and the mixture was dehydrated at 110 °C for 3 h. Toluene was then removed, the temperature was raised to 180 °C, and the reaction was carried out for 10 h. The reaction solution was poured into deionized water, filtered, washed with water, and dried to obtain sulfonated polysulfone.

[0099] Comparative Example 2

[0100] This comparative example provides a method for preparing MXene-sulfonated polysulfone composite material, including the following steps:

[0101] S1, 0.06 g MXene and 260 mL N-methylpyrrolidone were added to a three-necked flask and sonicated at 10 Hz and 100 W for 0.5 h to obtain an MXene dispersion;

[0102] S4, 5.0 g of 4,4'-dihydroxydiphenyl sulfone, 4.2 g of 4,4'-dichlorodiphenyl sulfone, and 2.6 g of 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid were added to the above modified MXene dispersion, followed by the addition of 3.0 g of K2CO3 and 50 mL of toluene. The mixture was dehydrated at 110 °C for 3 h, then the toluene was removed, the temperature was raised to 180 °C, and the reaction was carried out for 10 h. The reaction solution was poured into deionized water, filtered, washed with water, and dried to obtain the MXene-sulfonated polysulfone composite material.

[0103] The SEM images of the MXene-sulfonated polysulfone composite material prepared in this comparative example are shown below. Figure 2 As shown.

[0104] Performance testing

[0105] The modified MXene-sulfonated polysulfone composite materials prepared in Examples 1-5, the sulfonated polysulfone prepared in Comparative Example 1, and the MXene-sulfonated polysulfone composite materials prepared in Comparative Example 2 were dispersed in N-methylpyrrolidone to prepare dispersions with a mass concentration of 10 wt%. Each dispersion was poured into a polytetrafluoroethylene mold and dried at 100°C for 24 h to obtain the corresponding proton exchange membranes.

[0106] (1) Proton exchange capacity (IEC) test

[0107] Approximately 0.5 g of proton exchange membrane was vacuum dried at 80 °C for 10 h and then weighed, denoted as M (g). The proton exchange membrane was then placed in 30 mL of a sealed 1 mol / L sodium chloride solution and soaked at 25 °C for 24 h. One to two drops of phenolphthalein were added as an indicator. The solution was prepared using a 0.01 mol / L (C) solution. NaOH Titrate with sodium hydroxide solution until the solution turns pink and does not fade for 30 seconds, then record the volume V of sodium hydroxide solution consumed at this point. NaOH (mL), and then calculate the proton exchange capacity (IEC) using the following formula:

[0108]

[0109] (2) Proton conductivity

[0110] The proton exchange membrane was cut into 1cm × 3cm strips. The width W (cm) and thickness D (cm) of the dry strips were measured. The strips were then immersed in a 0.5mol / L sulfuric acid solution for 6 hours and washed with deionized water until neutral. The strips were then placed on two parallel platinum electrodes spaced L (cm) apart. The impedance R (Ω) of the membrane between the platinum electrodes was measured using an electrochemical workstation at 70℃. The proton conductivity σ (S / cm) was calculated using the following formula:

[0111]

[0112] (3) Methanol penetration rate

[0113] The methanol permeability was tested using cyclic voltammetry, with the proton exchange membrane placed in an H-type electrolytic cell, such as... Figure 3 As shown, cyclic voltammetry was performed. Methanol permeability (P) CH3OH The calculation formula is as follows:

[0114]

[0115] In the formula, P CH3OH Methanol permeability (cm) 2 ·s -1 );C A and C B V represents the methanol concentration (mol / L) in cells A and B, respectively. The initial methanol concentration in cell A is 5 mol / L, and the methanol concentration in cell B is the concentration (mol / L) of methanol on the permeate side at a certain moment, which can be calculated using the relationship between the standard methanol concentration and the current value of the cyclic voltammetric oxidation peak. B The volume of the solution in cell B is expressed in L; L represents the effective permeable area of ​​the membrane, which is 4.9 cm². 2 t represents the infiltration time (s).

[0116] The results are shown in Table 1.

[0117] Table 1

[0118]

[0119]

[0120] In summary, the modified MXene-sulfonated polysulfone composite material in the embodiments of the present invention has excellent proton conductivity and fuel barrier properties, and can be used as a material for preparing proton exchange membranes, showing broad application prospects in the field of fuel cells.

[0121] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A modified MXene-sulfonated polysulfone composite material, characterized in that, Including sulfonated polysulfone, to modify MXene by assembling the sulfonated polysulfone molecule via intermolecular hydrogen bonding; Wherein, the modified MXene is a protonic acid-modified MXene, and the protonic acid is a protonic acid containing a sulfonic acid group or a carboxyl group; The protic acid is at least one of 1,3-propanesulfonic acid lactone, 1,4-butanesulfonic acid lactone, maleic anhydride, succinic anhydride, oxalic acid, or phthalic acid.

2. The modified MXene-sulfonated polysulfone composite material as described in claim 1, characterized in that, The method for preparing the modified Mxene includes the following steps: MXene was dispersed in a polar solvent to obtain an MXene dispersion; The protic acid was added to the MXene dispersion, mixed evenly, stirred and reacted, separated into solid and liquid components, and dried to obtain the modified MXene.

3. The modified MXene-sulfonated polysulfone composite material as described in claim 2, characterized in that, The polar solvent is at least one of water, methanol, ethanol, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, or dimethyl sulfoxide; and / or The concentration of the MXene dispersion is 0.1wt%-1wt%; and / or The mass ratio of MXene to protic acid is 1:0.1-10; and / or The temperature of the stirring reaction is 50℃-100℃, and the reaction time is 0.5h-5h.

4. The method for preparing the modified MXene-sulfonated polysulfone composite material according to any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Disperse the modified MXene in an organic solvent to obtain a modified MXene dispersion; Step 2: Add the sulfonated polysulfone monomer to the modified MXene dispersion, mix evenly, add the catalyst and dehydrating agent, heat to carry out dehydration reaction, remove the dehydrating agent after the reaction is completed, react at 160℃-200℃ for 6h-48h, separate the solid and liquid, wash, dry to obtain the modified MXene-sulfonated polysulfone composite material.

5. The method for preparing the modified MXene-sulfonated polysulfone composite material as described in claim 4, characterized in that, In step one, the concentration of the modified MXene dispersion is 0.04wt%-2wt%; and / or In step one, the sulfonated polysulfone monomer is 4,4'-dihydroxydiphenyl sulfone, 4,4'-dichlorodiphenyl sulfone, and 4,4'-dichlorodiphenyl sulfone-3,3'-disulfonic acid; and / or In step one, the organic solvent is at least one selected from N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or sulfolane; and / or In step two, the mass ratio of the sulfonated polysulfone monomer to the modified MXene is 1-100:0.1; and / or In step two, the catalyst is potassium carbonate, and the dehydrating agent is toluene; and / or In step two, the temperature of the dehydration reaction is 100℃-120℃, and the dehydration time is 1h-6h.

6. The application of the modified MXene-sulfonated polysulfone composite material according to any one of claims 1-3 in proton exchange membrane fuel cells.

7. A proton exchange membrane, characterized in that, Including the modified MXene-sulfonated polysulfone composite material according to any one of claims 1-3.

8. A fuel cell membrane electrode assembly, characterized in that, Includes the proton exchange membrane as described in claim 7.

9. A proton exchange membrane fuel cell, characterized in that, Includes the fuel cell membrane electrode as described in claim 8.

Images