Two-layer polymer electrolyte membrane

Abstract

The present disclosure relates to a bilayer polymer electrolyte membrane comprising a first layer and a second layer, the first layer comprising a perfluorosulfonic acid and the second layer comprising a crosslinked polysulfonated polymer, the first layer disposed on the second layer. The present disclosure further relates to methods of making the bilayer polymer electrolyte membrane, as well as membrane electrode assemblies and fuel cells comprising the bilayer polymer electrolyte membrane.

Description

[Technical field]

[0001] Related Applications This application claims the benefit of U.S. Provisional Application Nos. 63 / 331007, filed April 14, 2022, 63 / 433574, filed December 19, 2022, 63 / 453499, filed March 21, 2023, and 63 / 454771, filed March 27, 2023. The entire teachings of each of the above applications are incorporated herein by reference.

[0002] government support This invention was made with Government support under Grant No. DE-SC0021832 awarded by the Department of Energy and Grant No. DE-AR0001242 awarded by ARPA-E. The Government has certain rights in this invention. [Background technology]

[0003] 2. Background of the Invention Proton exchange membrane fuel cells (PEMFCs) are environmentally friendly energy conversion devices that operate at low temperatures and are more efficient than existing internal combustion engines. With these advantages, PEMFCs have emerged as a popular alternative to fossil fuels in the transportation industry and have the potential for use in a wide range of applications, such as portable devices and stationary power supply systems.

[0004] The proton exchange membrane (PEM), which conducts protons and serves to separate the cathode and anode, is one of the most important elements of a PEMFC. The PEM significantly affects the overall performance of the fuel cell; therefore, improving the efficiency of a fuel cell requires a PEM that has high ionic conductivity, has low fuel crossover, and offers high physicochemical and mechanical stability. Because PEMFCs use a thin membrane as their electrolyte, these devices are more mobile and compact than other types of fuel cells. However, the thin membrane is also a barrier to the flow of the fuel gas (hydrogen, H 2) crossover, negatively affecting cell efficiency. Therefore, a PEM with high ionic conductivity and reduced hydrogen crossover is needed. Summary of the Invention

[0005] Summary of the Invention In a first aspect, the invention is a bilayer polymer electrolyte membrane comprising a first layer and a second layer, wherein: the first layer comprises perfluorosulfonic acid (PFSA) and the second layer comprises a crosslinked polysulfonated polymer comprising sulfonated polyphenylsulfone (sPPS), sulfonated polyetheretherketone (sPEEK), sulfonated polyphosphazene (sPOP), sulfonated polybenzimidazole (sPBI), sulfonated polyethersulfone (sPES), sulfonated polyphenylene oxide (sPPO), sulfonated polyarylene ether ketone (sPAEK), sulfonated poly(sulfone), sulfonated poly(sulfide sulfone), sulfonated polyimide (sPI), sulfonated poly(etherimide) (sPEI), sulfonated poly(amine) or combinations thereof, and the first layer is disposed on the second layer.

[0006] In a second aspect, the present invention provides a method for producing a pharmaceutical composition comprising: a) providing a first layer having a first surface and a solution or suspension comprising a polysulfonated polymer and a cross-linking reagent; b) coating a first surface of a first layer with a solution or suspension, thereby producing a coated first layer; c) exposing the coated first layer to conditions sufficient for the polysulfonated polymer and the cross-linking reagent to undergo a cross-linking reaction, thereby producing a bilayer polymer electrolyte membrane. A method of making a bilayer polymer electrolyte membrane as described herein with respect to the first embodiment and various aspects thereof, comprising:

[0007] In a third aspect, the invention is a membrane electrode assembly (MEA) comprising a bilayer polymer electrolyte membrane as described herein with respect to the first aspect and various aspects thereof; a cathode; and an anode, wherein the bilayer electrolyte membrane is disposed between the anode and the cathode.

[0008] In a fourth aspect, the invention is a fuel cell comprising one or more of the MEAs described herein with respect to the third aspect and various aspects thereof, and one or more gas flow bipolar plates. [Brief description of the drawings]

[0009] BRIEF DESCRIPTION OF THE DRAWINGS The foregoing will be apparent from the following more particular description of illustrative embodiments of the invention. [Figure 1] FIG. 1 is a schematic representation of the degradation of a Nafion® membrane as a result of hydrogen crossover. [Diagram 2] FIG. 2 is a schematic representation of the reduction in hydrogen crossover due to the presence of a crosslinked polymer layer on top of the PFSA layer, resulting in reduced degradation of the PFSA layer. [Diagram 3] FIG. 3 shows a plot illustrating a theoretical calculation of hydrogen crossover and resistance of a coated PFSA membrane as a function of coating thickness. [Figure 4] FIG. 4 shows cyclic voltammograms of a Nafion® 211 membrane and a membrane containing a layer of Nafion® 211 coated with crosslinked sulfonated polyphenylsulfone (sPPS). [Diagram 5] FIG. 5 shows plots illustrating fuel cell polarization and power curves for a Nafion® 211 membrane (squares) and a membrane comprising a layer of Nafion® 211 coated with a layer of sPPS (diamonds). [Figure 6]FIG. 6 shows plots illustrating the results of a faster accelerated stress test (FAST) of a Nafion® 211 membrane and a membrane including a layer of Nafion® 211 coated with a layer of crosslinked sPPS. [Figure 7] FIG. 7 shows a schematic representation of a PEM-containing fuel cell. [Figure 8] FIG. 8 shows a plot showing the water stability of sPPS before and after crosslinking. [Figure 9] FIG. 9 shows a plot showing the relationship between the degree of crosslinking and the conductivity of crosslinked sPPS. [Figure 10] FIG. 10 shows plots showing H2 crossover through membranes containing only Nafion® 211 or layers of Nafion® 211 coated with layers of crosslinked sPPS of varying thickness. [Figure 11] FIG. 11 shows a plot showing the relationship between crosslinked sPPS coating thickness and the durability of the resulting bilayer membrane. [Figure 12] FIG. 12 shows plots showing H2 crossover as a function of time in accelerated stress tests (AST) for membranes containing only Nafion® 211 or layers of Nafion® 211 coated with layers of crosslinked sPPS of varying thickness. [Figure 13] 13 shows a plot containing fuel cell polarization curves, where the dashed line corresponds to the voltage-current curve (left axis) and the solid line corresponds to the current density curve (right axis), with the squares representing the supported Aquivion®-based layer and the triangles representing the Nafion® 211-based layer. [Figure 14] FIG. 14 shows plots showing H2 crossover through a membrane containing only the base layer (dark line) or a base layer coated with a 1.5 μm coating of 40% crosslinked sPPS (light line). [Figure 15]FIG. 15 shows the area specific resistance values ​​as measured by electrochemical impedance spectroscopy for a bilayer membrane including a 25 μm Nafion® 211 membrane, a 1.5 μm 40% cross-linked sPPS membrane and a 25 μm Nafion® 211 layer with a 1.5 μm 40% cross-linked sPPS coating. [Figure 16] FIG. 16 shows the 1H NMR spectrum of sPPS. [Figure 17] FIG. 17 shows a plot containing fuel cell polarization curves for 1.5 μm sPPS coated Nafion® 211 with various crosslinkers, where the dashed line corresponds to the voltage-current curve (left axis) and the solid line corresponds to the current density curve (right axis). 1.3sHQ is Nafion® 211 (30% crosslinked) coated with approximately 1.5 μm of sPPS crosslinked with 1.3 molecules of 2,5-dihydroxybenzenesulfonic acid per sPPS repeat unit; 1.3HQ is Nafion® 211 (29% crosslinked) coated with approximately 1.5 μm of sPPS crosslinked with 1.3 molecules of hydroquinone per sPPS repeat unit; 1BP is Nafion® 211 (32% crosslinked) coated with approximately 1.5 μm of sPPS crosslinked with 1 molecule of biphenyl per sPPS repeat unit; and 6EG is Nafion® 211 (40% crosslinked) coated with approximately 1.5 μm of sPPS crosslinked with 6 molecules of ethylene glycol per sPPS repeat unit. [Figure 18] FIG. 18 shows plots showing H2 crossover through membranes containing Nafion® 211 coated with a 1.5 μm coating of sPPS crosslinked with various crosslinkers; 3sHQ: 0.513 mA / cm2, 1.3HQ: 0.651 mA / cm2, 1BP: 0.737 mA / cm2, 6EG: 0.736 mA / cm2, Nafion® 211: 1.39 mA / cm2. [Figure 19]19 shows a plot containing fuel cell polarization curves for bilayer membranes containing Nafion® 211 coated with sPPS, sPPO or sPSU crosslinked with hydroquinone, with dashed lines corresponding to voltage-current curves (left axis) and solid lines corresponding to current density curves (right axis). sPPS is Nafion® 211 (29% crosslinked) coated with approximately 1.5 μm of sPPS crosslinked with 1.3 molecules of hydroquinone per sPPS repeat unit; sPSU is Nafion® 211 (90% crosslinked) coated with approximately 1.5 μm of sPSU crosslinked with 1.3 molecules of hydroquinone per sPSU repeat unit; sPPO is Nafion® 211 (90% crosslinked) coated with approximately 1.5 μm of sPPO crosslinked with 0.5 molecules of hydroquinone per repeat unit. [Figure 20] FIG. 20 shows plots illustrating H2 crossover through bilayers containing Nafion® 211 coated with sPPS, sPPO or sPSU crosslinked with hydroquinone; sPPS: 0.651 mA / cm2, sPSU: 1.216 mA / cm2, sPPO: 1.903 mA / cm2, Nafion 211: 1.39 mA / cm2 (labels for curves are the same as in FIG. 19). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The foregoing will become apparent from the following more particular description of exemplary embodiments of the invention, as illustrated in the accompanying drawings, in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the invention.

[0011] Detailed Description of the Invention A description of exemplary embodiments of the present invention follows.

[0012] Hydrogen crossover is the unwanted diffusion of hydrogen from the anode to the cathode through the membrane in a fuel cell. Hydrogen crossover can have at least three effects, including reduced fuel efficiency, reduced cathode potential, and the formation of aggressive peroxide radicals. The crossing hydrogen can react directly with oxygen at the cathode surface, resulting in a lower cathode potential than that of the fuel cell. More seriously, the H 2 and O 2 This direct reaction between H and H can generate peroxide radicals that not only attack the catalyst layer, but also the membrane, resulting in significant catalyst layer and membrane degradation. 2 and O 2 It has been shown that the formation of hot-points or hydrogen peroxide due to the highly exothermic chemical reaction between the hydrogen crossover and the membrane can also cause pin-heeling in the membrane, destroying the MEA and creating safety issues. Accelerated sintering of the catalyst could also be caused by this hydrogen crossover.

[0013] In some embodiments, the present disclosure relates to a bilayer polymer electrolyte membrane that exhibits reduced hydrogen crossover. The membrane comprises a layer of perfluorosulfonic acid (PFSA), such as Nafion®, and a coating comprising crosslinked polysulfonated polyelectrolyte. Sulfonated polyelectrolytes, such as polyphenylsulfone (sPPS), sulfonated polyetheretherketone (sPEEK), sulfonated polyphosphazene (sPOP), sulfonated polybenzimidazole (sPBI), sulfonated polyethersulfone (sPES), sulfonated polyphenylene oxide (sPPO), and sulfonated polyaryleneetherketone (sPAEK), sulfonated poly(sulfone), sulfonated poly(sulfide sulfone), sulfonated polyimide (sPI), sulfonated poly(etherimide) (sPEI) and sulfonated poly(amine) can be used in the coating layer. The coating layer has lower hydrogen permeation compared to the PFSA, thus reducing hydrogen crossover through the membrane (FIGS. 1 and 2).

[0014] The plot in FIG. 3 shows the design criteria for the coated membrane. 2 The theoretical calculations of hydrogen crossover and resistance of the coated PFSA as a function of coating thickness are shown in Figure 4. The cyclic voltammograms in Figure 4 show hydrogen crossover measurements for Nafion® 211 and Nafion® 211 coated with 1 μm crosslinked sPPS. The plots in Figure 5 show fuel cell polarization and power curves for Nafion® 211 and Nafion® 211 with 1 μm crosslinked sPPS coating. These data show that the hydrogen crossover is significantly higher than that of Nafion® 211 without a polymer coating. 2 6 shows that the cross-linked sPPS coating reduces the cross-over by 44%. Furthermore, the fast accelerated stress test (FAST) results in FIG. 6 show that the presence of the cross-linked sPPS coating nearly doubles the durability of the membrane. The membrane failure time for Nafion® 211 is about 5000 equivalent hours, while for Nafion® 211 with a 1 μm cross-linked sPPS coating, the failure time is about 9500 equivalent hours.

[0015] definition Numerical ranges include the numbers that define the range. For example, "x is an integer from 5 to 14" means that x can be 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14. Measured and measurable values ​​are understood to be approximate, taking into account significant figures and errors associated with measurements. As used herein, the terms "about" and "approximately" have their art-understood meanings; the use of one over the other does not necessarily imply a different range. Unless otherwise indicated, numerical values ​​used herein, with or without modifiers such as "about" or "approximately", should be understood to encompass normal deviations and / or variations as would be understood by one of ordinary skill in the relevant art. In certain embodiments, the term "about" or "approximately" refers to a range of values ​​that falls within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less in either direction (greater or less) of the stated reference value, unless otherwise stated or clear from the context (except where such number exceeds 100% of the possible value).

[0016] The term "bilayer polyelectrolyte membrane," as used herein, refers to a membrane that includes two layers disposed on top of one another, each layer including a polyelectrolyte. The two layers may be attached to one another through the formation of chemical bonds or through van der Waals interactions.

[0017] As used herein, the term "polysulfonated polymer" or "sulfonated polymer" refers to a polymer having multiple sulfonic acid or sulfonate groups: S(O) 2 OH or S(O) 2 O - M + (In the formula, M + is a counter ion.

[0018] As used herein, the term "degree of sulfonation" refers to the number of repeating units that have at least one sulfonic acid / sulfonate group. For example, a degree of sulfonation of 20% indicates a polymer that has 20% of its repeating units sulfonated, and a degree of sulfonation of 100% indicates that all repeating units in the polymer contain one sulfonic acid / sulfonate group. This may include polymers that contain multiple sulfonic acids / sulfonate groups per repeating unit (e.g., disulfonated, trisulfonated, tetrasulfonated, etc.). In some embodiments, the sulfonated polymer may contain an average of 2 sulfonic acid groups per repeating unit, which corresponds to a degree of sulfonation of 200%. In some embodiments, the sulfonated polymer may contain an average of 2, 3, 4, or 5 sulfonic acid groups per repeating unit, which corresponds to a degree of sulfonation of 200%, 300%, 400%, or 500%, respectively. In some embodiments, the sulfonated polymer can contain an average of 1.5 to 2.5 sulfonic acid groups per repeat unit, which corresponds to a degree of sulfonation of 150% to 200%.

[0019] The sulfonated polymers of the present disclosure may also be characterized by the average number of sulfonic acid groups per repeat unit. For example, sulfonated polyphenylsulfone (sPPS) may contain 1, 2, 3, 4, 5, 6, 7, or 8 sulfonic acid groups per repeat unit. For example, the repeat unit of sPPS may contain 2 sulfonic acid groups: [ka] Alternatively, the repeating unit of sPPS may contain 4 or 6 sulfonic acid groups: [ka] may include.

[0020] In a given polymer, some repeat units may have, for example, one sulfonic acid group, some repeat units may have two sulfonic acid groups, and some repeat units may have three or more sulfonic acid groups. 1The number of sulfonic acid groups per repeat unit, as measured in the bulk polymer by analyzing the 1 H NMR spectrum or the ion exchange capacity, corresponds to the average number of sulfonic groups in all repeat units of the polymer.

[0021] As used herein, the term "polyphenylsulfone" refers to a compound having the following repeating units: [ka] The term "polymer" refers to a polymer comprising:

[0022] The sulfonated polyphenylsulfone may contain 1, 2, 3, 4, 5, 6, 7 or 8 sulfonic acid groups per repeat unit.

[0023] As used herein, the term "polyetheretherketone" refers to a polymer having the following repeating units: [ka] The term "polymer" refers to a polymer comprising:

[0024] The sulfonated polyetheretherketone may contain 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 sulfonic acid groups per repeat unit.

[0025] As used herein, the term "polyphosphazine" refers to a compound having the following repeating units: [ka] The term "polymer" refers to a polymer comprising:

[0026] As used herein, the term "polybenzimidazole" refers to a compound having the following repeating units: [ka] The term "polymer" refers to a polymer comprising:

[0027] The sulfonated polybenzimidazole may contain 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 sulfonic acid groups per repeat unit.

[0028] As used herein, the term "polyethersulfone" refers to a polymer having the following repeating units: [ka] The term "polymer" refers to a polymer comprising:

[0029] The sulfonated polyethersulfone may contain 1, 2, 3, 4, 5, 6, 7 or 8 sulfonic acid groups per repeat unit.

[0030] As used herein, the term "polyphenylene oxide" refers to a polymer having the following repeating units: [ka] The term "polymer" refers to a polymer comprising:

[0031] The sulfonated polyphenylene oxide may contain one or two sulfonic acid groups per repeat unit.

[0032] As used herein, the term "polyarylene ether ketone" refers to a polymer having the following repeating units: [ka] The term "polymer" refers to a polymer that contains one or more of the following:

[0033] The sulfonated polyarylene ether ketone can contain 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 sulfonic acid groups per repeat unit.

[0034] As used herein, the term "poly(sulfone)" refers to a polymer having the following repeating units: [ka] The term "polymer" refers to a polymer comprising:

[0035] The sulfonated poly(sulfone) (sPSU) may contain 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16 sulfonic acid groups per repeat unit.

[0036] As used herein, the term "poly(sulfide sulfone)" refers to a compound having the following repeating units: [ka] The term "polymer" refers to a polymer comprising:

[0037] The sulfonated poly(sulfide sulfone) may contain 1, 2, 3, 4, 5, 6, 7 or 8 sulfonic acid groups per repeat unit.

[0038] As used herein, the term "polyimide" refers to a polymer having the following repeating units: [ka] The term "polymer" refers to a polymer comprising:

[0039] The sulfonated polyimides may contain 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 sulfonic acid groups per repeat unit.

[0040] As used herein, the term “poly(etherimide)” refers to a polymer having the following repeating units: [ka] The term "polymer" refers to a polymer comprising:

[0041] The sulfonated poly(etherimide) may contain 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 sulfonic acid groups per repeat unit.

[0042] Any of the above polymer repeat units may be -CN, -NO 2 , -N 3, -OH, F, Cl, Br, I, oxo, -SO 2 H, -SO 3 H, -OR aa , -NH(R aa ) 2 , -N(R aa ) 2 , -N(R aa ) 3 + X - , -SH, -SR aa , -C(=O)R aa , -CO 2 H, -CHO, -CO 2 R aa , -OC(=O)R aa , -OCO 2 R aa , -C(=O)N(R aa ) 2 , -OC(=O)N(R aa ) 2 , -NR aa C(=O)R aa , -NR aa CO 2 R aa , -NR aa C(=O)N(R aa ) 2 , -C(=NR aa )R aa , -C(=O)NR aa SO 2 R aa , -NR aa SO 2 R aa , -SO 2 N(R aa ) 2 , -SO 2 R aa , -SO 2 OR aa , -OSO 2 R aa , -S(=O)R aa , -OS(=O)R aa , -Si(R aa ) 3 , -OSi(R aa ) 3 , C 1-12 Alkyl, C 1-12 Alkoxyl, C 1-12 Haloalkyl, C3-12 Cycloalkyl, 3- to 16-membered heterocyclyl, and C 6-12 One or more hydrogen atoms may be replaced by aryl, where X - is the counter ion and R aa Each example is independently H, -OH, C 1-10 Alkyl, C 1-10 Haloalkyl, C 3-12 Cycloalkyl, 5-16 membered heterocyclyl and C 6-12 aryl, or two R aa The groups are linked to form a 3- to 16-membered heterocyclyl.

[0043] As used herein, the term "polyalcohol" refers to an alcohol containing more than one hydroxyl group. Examples of polyalcohols include, but are not limited to, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, glycerol, erythriol, xylitol, hydroquinone, catechol, resorcinol, and phloroglucinol.

[0044] As used herein, the term "polyelectrolyte" refers to a polymer that includes repeating units that have charged or ionizable groups. Under a particular set of conditions, a polyelectrolyte has a net negative or net positive charge. In some embodiments, a polyelectrolyte is or includes a polycation; in some embodiments, a polyelectrolyte is or includes a polyanion. A polycation has a net positive charge, and a polyanion has a net negative charge. The net charge of a given polyelectrolyte may depend on the surrounding chemical conditions, such as pH.

[0045] As used herein, the term "perfluorosulfonic acid" refers to a compound having the following structural formula: [ka] The present invention refers to a polymer represented by the formula: In the formula, R frepresents a perfluoroalkylene or perfluorooxyalkylene group, and x and y are the relative proportions of perfluoromonomer and sulfonated monomer, respectively. As used herein, the term "perfluoroalkylene" or "perfluorooxyalkylene" refers to an alkylene or oxyalkylene group in which all hydrogen atoms have been replaced with fluorine. A class of PFSAs are represented by structural formula (I): [ka] Such PFSAs are typically classified according to the length of their side chains. For example, Aquivion® (formerly Dow SSC) PFSA is generally classified as a short side chain (SSC) PFSA, while Nafion® is considered a long side chain (LSC) PFSA. Examples of commercial PFSAs include: [Table 1]

[0046] As used herein, the term "crosslinking" refers to the formation of a covalent or ionic bond between a sulfonic acid group of a sulfonated polymer and a crosslinking reagent. For example, crosslinking refers to the formation of a sulfonate ester as a result of the reaction between a sulfonic acid group of a sulfonated polymer and a polyol. In some embodiments, crosslinking refers to the formation of a sulfonamide as a result of the reaction between a sulfonic acid group of a sulfonated polymer and a polyamine. As used herein, the term "crosslinking" does not refer to the formation of a covalent or ionic bond between a crosslinking reagent and any functional group in the repeating unit of the polymer other than the sulfonic acid group.

[0047] As used herein, the term "crosslinked polymer" refers to a polymer in which two or more non-adjacent repeat units of the same backbone are linked through a bridging moiety. The term "crosslinked polymer" also refers to two or more different backbones that are linked through multiple bridging moieties.

[0048] As used herein, the term "bridging moiety" refers to a multivalent, e.g., divalent or trivalent, moiety that forms a covalent bond with one or more non-adjacent repeat units of the same polymer backbone or one or more repeat units of different backbones. The bridging moiety may contain a charged group, e.g., an ammonium group or a metal ion, which forms an electrostatic / ionic bond with a sulfonic acid group attached to a repeat unit of a sulfonated polymer.

[0049] As used herein, the term "crosslinking reaction" refers to a chemical reaction between a sulfonic acid group attached to a repeating unit of a sulfonated polymer and a crosslinking reagent, resulting in the formation of covalent or electrostatic / ionic bonds between the polymer chain and the crosslinking reagent.

[0050] As used herein, the term "conditions sufficient for the polymer and cross-linking reagent to undergo a cross-linking reaction" refers to the external stimulus (e.g., heat, UV light, microwave radiation, the presence of a chemical initiator, e.g., a radical initiator) and the time necessary to form a cross-linked polymer.

[0051] As used herein, the term "gel fraction (%)" is calculated based on the following formula: [[M(f) / [M(i)]]*100, where M(f) is the dry mass of the membrane exposed to a solvent that dissolves the original polymer and crosslinker, and M(i) is the dry mass of the membrane prior to exposure to the dissolution solvent. The gel fraction indicates the percentage of polymer and linker that remain in the network after exposure to a solvent that dissolves each individual component.

[0052] As used herein, the term "repeating unit" (also known as monomeric unit) refers to a chemical moiety that periodically repeats itself to make a complete polymer chain (excluding the end groups) by sequentially linking repeating units together. A polymer may contain one or more different repeating units.

[0053] As used herein, a polymer "backbone" or a polymer "backbone" is a series of bonded atoms that together make a continuous chain of the molecule. As used herein, a polymer "side chain" is a series of bonded atoms that are pendant from the polymer backbone.

[0054] As used herein, "the PFSA and the matrix polymer form an interpenetrating network" refers to a porous matrix that contains the PFSA within its pores. The porous matrix can be infiltrated with the PFSA, for example, by immersing the matrix in a solution of the PFSA or by spraying a solution of the PFSA onto the porous matrix. Alternatively, the porous matrix can be infiltrated with a solution of the PFSA monomer, followed by a polymerization reaction within the pores of the matrix.

[0055] As used herein, "unsupported membrane" refers to a membrane that includes only a PFSA layer and a crosslinked polysulfonated polymer layer, without any other layers, supports, or reinforcing materials.

[0056] As used herein, the term "continuous layer" refers to a layer in which any point on the layer can be connected to any other point on the layer by a straight line, without gaps or openings, and each point of the line belongs to the layer.

[0057] As used herein, the term "alkyl" refers to the radical of a straight or branched chain saturated hydrocarbon group having 1 to 10 carbon atoms ("C 1-10 In some embodiments, an alkyl group has 1 to 9 carbon atoms ("C 1-9 In some embodiments, the alkyl group has 1 to 8 carbon atoms ("C 1-8 In some embodiments, the alkyl group has 1 to 7 carbon atoms ("C 1-7 In some embodiments, the alkyl group has 1 to 6 carbon atoms ("C 1-6 In some embodiments, the alkyl group has 1 to 5 carbon atoms ("C 1-5In some embodiments, the alkyl group has 1 to 4 carbon atoms ("C 1-4 In some embodiments, the alkyl group has 1 to 3 carbon atoms ("C 1-3 In some embodiments, the alkyl group has 1 to 2 carbon atoms ("C 1-2 In some embodiments, the alkyl group has one carbon atom ("C 1 In some embodiments, the alkyl group has 2 to 6 carbon atoms ("C 2-6 "Alkyl"). C 1-6 Examples of alkyl groups include methyl (C 1 ), ethyl (C 2 ), Propyl (C 3 ) (e.g. n-propyl, isopropyl), butyl (C 4 ) (e.g. n-butyl, tert-butyl, sec-butyl, iso-butyl), pentyl (C 5 ) (e.g. n-pentyl, 3-pentanyl, amyl, neopentyl, 3-methyl-2-butanyl, tertiary amyl) and hexyl (C 6 ) (e.g., n-hexyl). Further examples of alkyl groups include n-heptyl (C 7 ), n-octyl (C 8 ), and the like. Unless otherwise specified, each instance of an alkyl group is independently unsubstituted ("unsubstituted alkyl") or substituted ("substituted alkyl") with one or more substituents (e.g., halogens such as F). In certain embodiments, an alkyl group is an unsubstituted C 1-10 Alkyl (unsubstituted C 1-6 Alkyl, e.g. -CH 3 (Me), unsubstituted ethyl (Et), unsubstituted propyl (Pr, e.g., unsubstituted n-propyl (n-Pr), unsubstituted isopropyl (i-Pr), unsubstituted butyl (Bu, e.g., unsubstituted n-butyl (n-Bu), unsubstituted tert-butyl (tert-Bu or t-Bu), unsubstituted sec-butyl (sec-Bu), unsubstituted isobutyl (i-Bu), etc.). In some embodiments, the alkyl group is a substituted C 1-10 Alkyl (substituted C 1-6Alkyl, e.g. -CF 3 , Bn, etc.).

[0058] As used herein, the term "alkenyl" refers to the radical of a straight- or branched-chain hydrocarbon group having 2 to 10 carbon atoms and one or more carbon-carbon double bonds (e.g., 1, 2, 3, or 4 double bonds) ("C 2-10 In some embodiments, the alkenyl group has 2 to 9 carbon atoms ("C 2-9 In some embodiments, the alkenyl group has 2 to 8 carbon atoms ("C 2-8 In some embodiments, the alkenyl group has 2 to 7 carbon atoms ("C 2-7 In some embodiments, the alkenyl group has 2 to 6 carbon atoms ("C 2-6 In some embodiments, the alkenyl group has 2 to 5 carbon atoms ("C 2-5 In some embodiments, the alkenyl group has 2 to 4 carbon atoms ("C 2-4 In some embodiments, the alkenyl group has 2 to 3 carbon atoms ("C 2-3 In some embodiments, the alkenyl group has two carbon atoms ("C 2 The one or more carbon-carbon double bonds can be internal (e.g., in 2-butenyl) or terminal (e.g., in 1-butenyl). 2-4 Examples of alkenyl groups include, but are not limited to, vinyl (C 2 ), 1-propenyl (C 3 ), 2-propenyl (C 3 ), 1-butenyl (C 4 ), 2-butenyl (C 4 ) etc. 2-6 Examples of alkenyl groups include the above-mentioned C 2-4 Alkenyl groups, as well as pentenyl (C 5 ), hexenyl (C 6 Further examples of alkenyl include heptenyl (C 7 ), octenyl (C8 ), and the like. Unless otherwise specified, each instance of an alkenyl group is independently unsubstituted ("unsubstituted alkenyl") or substituted ("substituted alkenyl") with one or more substituents. In certain embodiments, an alkenyl group is an unsubstituted C 2-10 In some embodiments, the alkenyl group is a substituted C 2-10 It is alkenyl.

[0059] As used herein, the term "alkynyl" refers to the radical of a straight or branched chain hydrocarbon group having 2 to 10 carbon atoms and one or more carbon-carbon triple bonds (e.g., 1, 2, 3, or 4 triple bonds) ("C 2-10 In some embodiments, the alkynyl group has 2 to 9 carbon atoms ("C 2-9 In some embodiments, the alkynyl group has 2 to 8 carbon atoms ("C 2-8 In some embodiments, the alkynyl group has 2 to 7 carbon atoms ("C 2-7 In some embodiments, the alkynyl group has 2 to 6 carbon atoms ("C 2-6 In some embodiments, the alkynyl group has 2 to 5 carbon atoms ("C 2-5 In some embodiments, the alkynyl group has 2 to 4 carbon atoms ("C 2-4 In some embodiments, the alkynyl group has 2 to 3 carbon atoms ("C 2-3 In some embodiments, the alkynyl group has two carbon atoms ("C 2 The one or more carbon-carbon triple bonds can be internal (e.g., in 2-butynyl) or terminal (e.g., in 1-butynyl). 2-4 Examples of alkynyl groups include, but are not limited to, ethynyl (C 2 ), 1-propynyl (C 3 ), 2-propynyl (C 3 ), 1-butynyl (C 4 ), 2-butynyl (C 4 ) etc.2-6 Examples of alkynyl groups include the above-mentioned C 2-4 Alkynyl groups, as well as pentynyl (C 5 ), Hexynyl (C 6 Further examples of alkynyl include heptenyl (C 7 ), Octynyl (C 8 ) and the like. Unless otherwise specified, each instance of an alkynyl group is independently unsubstituted ("unsubstituted alkynyl") or substituted ("substituted alkynyl") with one or more substituents. In certain embodiments, an alkynyl group is an unsubstituted C 2-10 In some embodiments, the alkynyl group is a substituted C 2-10 It is alkynyl.

[0060] The term "aryl" refers to a radical of a monocyclic or polycyclic (e.g., bicyclic or tricyclic) 4n+2 aromatic ring system (e.g., having 6, 10 or 14 pi electrons shared among the cyclic array) having 6 to 14 ring carbon atoms and 0 heteroatoms provided within the aromatic ring system (e.g., having 6, 10 or 14 pi electrons shared among the cyclic array). 6-14 In some embodiments, an aryl group has 6 ring carbon atoms ("C 6 aryl"; e.g., phenyl). In some embodiments, an aryl group has 10 ring carbon atoms ("C 10 Aryl"; e.g. naphthyl, such as 1-naphthyl and 2-naphthyl). In some embodiments, an aryl group has 14 ring carbon atoms ("C 14 "Aryl"; e.g., anthracyl). "Aryl" also includes ring systems in which an aryl ring, as defined above, is fused with one or more carbocyclyl or heterocyclyl groups, and the radical or point of attachment is on the aryl ring, and in such instances the number of carbon atoms continues to designate the number of carbon atoms in the aryl ring system. Unless otherwise specified, each instance of an aryl group is independently unsubstituted ("unsubstituted aryl") or substituted with one or more substituents ("substituted aryl"). In certain embodiments, an aryl group is an unsubstituted C 6-14 In some embodiments, the aryl group is a substituted C6-14 It is aryl.

[0061] The term "haloalkyl" refers to a substituted alkyl group in which one or more of the hydrogen atoms are independently replaced with a halogen, such as fluoro, bromo, chloro, or iodo. In some embodiments, the haloalkyl moiety has 1 to 12 carbon atoms ("C 1-12 In some embodiments, the haloalkyl moiety has 1 to 6 carbon atoms ("C 1-6 In some embodiments, the haloalkyl moiety has 1 to 4 carbon atoms ("C 1-4 In some embodiments, the haloalkyl moiety has 1 to 3 carbon atoms ("C 1-3 In some embodiments, the haloalkyl moiety has 1 to 2 carbon atoms ("C 1-2 An example of a haloalkyl group is -CHF 2 , -CH 2 F, -CF 3 , -CH 2 CF 3 , -CF 2 CF 3 , -CF 2 CF 2 CF 3 , -CCl 3 , -CFCl 2 , -CF 2 Cl and the like.

[0062] The term "sulfonic acid group" refers to the following group: -S(O) 2 It is called OH.

[0063] The term "sulfonate" refers to a salt or ester of sulfonic acid, -S(O) 2OR, where R represents a cation, such as a metal or ammonium cation, or an aliphatic or aromatic substituent. Examples of sulfonates include salts such as lithium sulfonate, sodium sulfonate, potassium sulfonate, or ammonium sulfonate. In some embodiments, the term "sulfonate" refers to an ester of sulfonic acid, such as an optionally substituted C 1-12 Alkyl sulfonate or optionally substituted C 6 - 12 In some embodiments, R is a multivalent (e.g., divalent or trivalent) radical that forms a covalent or ionic bond with one or more sulfonic acid groups attached to the same or different sulfonated polymer chains, thereby forming a bond between the two or more -S(O) groups to which it is attached. 2 Together with the O-group it forms a bridging moiety.

[0064] The term "sulfonamide" refers to the amide of a sulfonic acid, -S(O) 2 NRR′, where R and R′ are each hydrogen or an optionally substituted aliphatic or aromatic substituent, such as an optionally substituted C 1-12 Alkyl or optionally substituted C 6 - 12 In some embodiments, R and / or R' are each polyvalent (e.g., divalent or trivalent) radicals that form covalent or ionic bonds with one or more sulfonic acid groups attached to the same or different sulfonated polymer chains, such that the two or more -S(O) to which it is attached are bonded. 2 Together with the O-group it forms a bridging moiety.

[0065] The addition of the suffix "-ene" to a base indicates that the group is a divalent moiety, for example, alkylene is a divalent moiety of alkyl, alkenylene is a divalent moiety of alkenyl, alkynylene is a divalent moiety of alkynyl, and arylene is a divalent moiety of aryl.

[0066] The term "substituted" refers to a moiety having a substituent replacing a hydrogen on one or more carbons of the backbone. "Substituted" or "substituted with" is understood to include the implicit proviso that such substitution is in accordance with the permissible valences of the substituted atom and substituent, and that the substitution results in a stable compound that does not undergo transformation, e.g., spontaneously by rearrangement, cyclization, elimination, and the like. As used herein, the term "substituted" is intended to include all permissible substituents of organic compounds. In a broad aspect, the permissible substituents include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, aromatic and nonaromatic substituents of organic compounds. The permissible substituents can be one or more and can be the same or different for appropriate organic compounds. For purposes of this invention, heteroatoms, such as nitrogen, can have hydrogen substituents and / or any permissible substituent of organic compounds described herein that satisfies the valence of the heteroatom. The substituents may include any of the substituents described herein, such as halogen, hydroxyl, carbonyl (e.g., carboxyl, alkoxycarbonyl, formyl, or acyl), thiocarbonyl (e.g., thioester, thioacetate, or thioformate), alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino, amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamide, sulfonyl, heterocyclyl, aralkyl, or aromatic or heteroaromatic moieties. It will be understood by those skilled in the art that the substituents may themselves be substituted where appropriate. Unless specifically described as "unsubstituted," references to chemical moieties herein are understood to include substituted variants. For example, references to "aryl" groups or moieties implicitly include both substituted and unsubstituted variants.

[0067] Exemplary carbon atom substituents include, but are not limited to, halogen, -CN, -NO 2 , -N 3 , -OH, F, Cl, Br, I, oxo, -SO 2 H, -SO 3 H, -ORaa , -NH(R aa ) 2 , -N(R aa ) 2 , -N(R aa ) 3 + X - , -SH, -SR aa , -C(=O)R aa , -CO 2 H, -CHO, -CO 2 R aa , -OC(=O)R aa , -OCO 2 R aa , -C(=O)N(R aa ) 2 , -OC(=O)N(R aa ) 2 , -NR aa C(=O)R aa , -NR aa CO 2 R aa , -NR aa C(=O)N(R aa ) 2 , -C(=NR aa )R aa , -C(=O)NR aa SO 2 R aa , -NR aa SO 2 R aa , -SO 2 N(R aa ) 2 , -SO 2 R aa , -SO 2 OR aa , -OSO 2 R aa , -S(=O)R aa , -OS(=O)R aa , -Si(R aa ) 3 , -OSi(R aa ) 3 , C 1-12 Alkyl, C 1-12 Haloalkyl, 3-16 membered heterocyclyl and C 6-12 aryl, wherein X - is the counter ion and R aaEach example is independently H, -OH, C 1-10 Alkyl, C 1-10 Haloalkyl, C 3-12 Cycloalkyl, 5-16 membered heterocyclyl and C 6-12 aryl or two R aa The groups are linked to form a 3- to 16-membered heterocyclyl.

[0068] In a first aspect, the invention is a bilayer polymer electrolyte membrane comprising a first layer and a second layer: the first layer comprises perfluorosulfonic acid (PFSA) and the second layer comprises a crosslinked polysulfonated polymer comprising sulfonated polyphenylsulfone (sPPS), sulfonated polyetheretherketone (sPEEK), sulfonated polyphosphazene (sPOP), sulfonated polybenzimidazole (sPBI), sulfonated polyethersulfone (sPES), sulfonated polyphenylene oxide (sPPO), sulfonated polyaryleneetherketone (sPAEK), sulfonated poly(sulfone) (sPSU), sulfonated poly(sulfide sulfone), sulfonated polyimide (sPI), sulfonated poly(etherimide) (sPEI), sulfonated poly(amine) or combinations thereof, and the first layer is disposed on the second layer.

[0069] In a first aspect of the first embodiment, the PFSA has structural formula (I): [ka] wherein x is an integer from 1 to 15, m is an integer from 0 to 2, and n is an integer from 1 to 5; [ka] represents the point of attachment to the adjacent repeat unit. For example, x is an integer from 5 to 14, m is 1 or 2, and n is 2 or 3. In some cases, m is 1 and n is 2.

[0070] In a second aspect of the first embodiment, the PFSA is a polymer comprising about 500 to about 1500 repeat units represented by structural formula (I). For example, the PFSA is a polymer comprising about 600 to about 1400, about 700 to about 1300, about 800 to about 1200, or about 900 to about 1100 repeat units represented by structural formula (I). For example, the PFSA is a polymer comprising about 1000 repeat units represented by structural formula (I). The remainder of the features and exemplary features of the second aspect are as described above with respect to the first aspect of the first embodiment.

[0071] In a third aspect of the first embodiment, the crosslinked polysulfonated polymer comprises sulfonated polyphenylsulfone (sPPS), sulfonated polyetheretherketone (sPEEK), sulfonated polyphosphazene (sPOP), sulfonated polybenzimidazole (sPBI), sulfonated polyethersulfone (sPES), sulfonated polyaryleneetherketone (sPAEK), sulfonated poly(sulfone) (sPSU), sulfonated poly(sulfide sulfone), sulfonated polyimide (sPI), sulfonated poly(etherimide) (sPEI), sulfonated poly(amine), or a combination thereof. For example, the crosslinked polysulfonated polymer comprises sPPS, sPES, sPSU, sulfonated poly(sulfide sulfone), or a combination thereof. For example, the crosslinked polysulfonated polymer comprises sPPS, sPES, sPSU, sulfonated poly(sulfide sulfone), or a combination thereof. For example, the crosslinked polysulfonated polymer comprises sPPS, sPEEK, sPOP or sPBI. For example, the crosslinked polysulfonated polymer comprises sPPS or sPSU. For example, the crosslinked polysulfonated polymer comprises sPPS. The remainder of the features and exemplary features of the third aspect are as described above with respect to the first and second aspects of the first embodiment.

[0072] In a fourth aspect of the first embodiment, the crosslinked polysulfonated polymer has the following structural formula: [ka] wherein R 1, R 2 , R 3 and R 4 Each of these is independently H, C 1-12 Alkyl, C 1-12 Haloalkyl, C 6-12 Aryl and C 6-14 Aryl (C 1-12 alkylene); M 2+ Mr. 2+ , Ca2 + , B.A. 2+ and Al(X) 2+ wherein X is a halide, acetate or nitrate; [ka] represents the point of attachment of the crosslinking moiety to the repeating unit of the crosslinked polysulfonated polymer. For example, the crosslinking moiety may have the following structural formula: [ka] For example, the bridging moiety may be represented by one of the following structural formulas: [ka] The remainder of the features and example features of the fourth aspect are as described above with respect to the first through third aspects of the first embodiment.

[0073] In a fifth aspect of the first embodiment, the first layer further comprises a porous matrix comprising a matrix polymer, and the PFSAs and the matrix polymer form an interpenetrating network. For example, the first layer comprises about 50 wt.% to about 99 wt.% PFSAs, about 55 wt.% to about 98 wt.% PFSAs, about 60 wt.% to about 97 wt.% PFSAs, about 70 wt.% to about 96 wt.% PFSAs, or about 80 wt.% to about 96 wt.% PFSAs. For example, the first layer comprises about 70 wt.% to about 99 wt.% PFSAs, such as about 78 wt.% to about 95 wt.% PFSAs. The remainder of the features and exemplary features of the fifth aspect are as described above with respect to the first to fourth aspects of the first embodiment.

[0074] In a sixth aspect of the first embodiment, the matrix polymer is polytetrafluoroethylene (PTFE). For example, the matrix polymer is expanded PTFE (ePTFE). The remainder of the features and exemplary features of the sixth aspect are as described above with respect to the first to fifth aspects of the first embodiment.

[0075] In the seventh aspect of the first embodiment, the degree of sulfonation of the crosslinked polysulfonated polymer is about 10% to about 400%. For example, the degree of sulfonation of the crosslinked polysulfonated polymer is about 10% to about 100%, about 20% to about 100%, about 30% to about 100%, about 40% to about 100%, about 50% to about 100%, about 60% to about 100%, about 70% to about 100%, about 80% to about 100%, about 50% to about 200%, about 80% to about 200%, about 10 ... about 250%, about 150% to about 200%, about 100% to about 300%, about 100% to about 350%, about 100% to about 400%, about 150% to about 250%, about 150% to about 300%, about 150% to about 350%, about 150% to about 400%, about 200% to about 300%, about 200% to about 350%, about 200% to about 400%, or about 250% to about 350%. For example, the degree of sulfonation of the crosslinked polysulfonated polymer is about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 100%, about 120%, about 140%, about 160%, about 180%, about 200%, about 220%, about 240%, about 260%, about 280%, about 300%, about 320%, about 340%, about 360%, about 380%, or about 400%. For example, the degree of sulfonation of the crosslinked polysulfonated polymer is about 30% to about 90%, about 40% to about 80%, or about 50% to about 60%. The remainder of the features and exemplary features of the seventh aspect are as described above with respect to the first to sixth aspects of the first embodiment.

[0076] In an eighth aspect of the first embodiment, the gel fraction of the crosslinked polysulfonated polymer is about 50% to about 100%. For example, the gel fraction of the crosslinked polysulfonated polymer is about 50%, about 60%, about 70%, about 80%, about 90% or about 100%. The remainder of the features and exemplary features of the eighth aspect are as described above with respect to the first to seventh aspects of the first embodiment.

[0077] In a ninth aspect of the first embodiment, the thickness of the first layer is about 5 μm to about 200 μm. For example, the thickness of the first layer is about 5 μm, about 10 μm, about 15 μm, about 20 μm, about 25 μm, about 30 μm, about 35 μm, about 40 μm, about 45 μm, about 50 μm, about 55 μm, about 60 μm, about 65 μm, about 70 μm, about 75 μm, about 80 μm, about 85 μm, about 90 μm, about 95 μm, about 100 μm, about 110 μm, about 120 μm, about 130 μm, about 140 μm, about 150 μm, about 160 μm, about 170 μm, about 180 μm, about 190 μm, or about 200 μm. For example, the first layer has a thickness of about 5 μm to about 175 μm. For example, the first layer has a thickness of about 25 μm. The remainder of the features and example features of the ninth aspect are as described above with respect to the first to eighth aspects of the first embodiment.

[0078] In a tenth aspect of the first embodiment, the second layer has a thickness of about 0.2 μm to about 175 μm. For example, the thickness of the second layer is about 0.2 μm, about 0.4 μm, about 0.6 μm, about 0.8 μm, about 1.0 μm, about 2.0 μm, about 3.0 μm, about 4.0 μm, about 5 μm, about 10 μm, about 15 μm, about 20 μm, about 25 μm, about 30 μm, about 35 μm, about 40 μm, about 45 μm, about 50 μm, about 55 μm, about 60 μm, about 65 μm, about 70 μm, about 75 μm, about 80 μm, about 85 μm, about 90 μm, about 95 μm, about 100 μm, about 110 μm, about 120 μm, about 130 μm, about 140 μm, about 150 μm, about 160 μm, or about 170 μm. For example, the thickness of the second layer is about 0.2 μm to about 10 μm, about 0.4 μm to about 5 μm, about 0.6 μm to about 2 μm, about 0.8 μm to about 1.5 μm. For example, the thickness of the second layer is about 0.75 μm. For example, the thickness of the second layer is about 1 μm. For example, the thickness of the second layer is about 1.5 μm. The remainder of the features and exemplary features of the tenth aspect are as described above with respect to the first to ninth aspects of the first embodiment.

[0079] In an eleventh aspect of the first embodiment, the first layer is continuous. The remainder of the features and example features of the eleventh aspect are as described above for the first through tenth aspects of the first embodiment.

[0080] In a twelfth aspect of the first embodiment, the membrane is unsupported. The remainder of the features and example features of the twelfth aspect are as described above in relation to the first to eleventh aspects of the first embodiment.

[0081] In a thirteenth aspect of the first embodiment, the PFSA has structural formula (I): [ka] wherein x is an integer from 5 to 14, m is 1 or 2, and n is 2 or 3; the crosslinked polysulfonated polymer is a polymer comprising sPPS and a repeating unit represented by the following structural formula: [ka] The remainder of the features and example features of the thirteenth aspect are as described above for the first through twelfth aspects of the first embodiment.

[0082] In a fourteenth aspect of the first embodiment, the first layer comprises a porous matrix comprising a matrix polymer, wherein the PFSA and the matrix polymer form an interpenetrating network; the PFSA has Structural Formula (I): [ka] wherein x is an integer from 5 to 14, m is 1 or 2, and n is 2 or 3; the matrix polymer comprises ePTFE; the crosslinked polysulfonated polymer comprises sPPS and a polymer having the following structural formula: [ka] The remainder of the features and example features of the fourteenth aspect are as described above for the first through thirteenth aspects of the first embodiment.

[0083] In a fifteenth aspect of the first embodiment, the crosslinked polysulfonated polymer is sulfonated polyphenylsulfone (sPPS), sulfonated polyetheretherketone (sPEEK), sulfonated polyphosphazene (sPOP), sulfonated polybenzimidazole (sPBI), sulfonated polyethersulfone (sPES), sulfonated polyaryleneetherketone (sPAEK), sulfonated poly(sulfone) (sPSU), sulfonated poly(sulfide sulfone), sulfonated polyimide (sPI), sulfonated poly(etherimide) (sPEI), sulfonated poly(amine) or a combination thereof. For example, the crosslinked polysulfonated polymer is sPPS, sPES, sPSU, sulfonated poly(sulfide sulfone) or a combination thereof. For example, the crosslinked polysulfonated polymer is sPPS, sPES, sPSU, sulfonated poly(sulfide sulfone) or a combination thereof. For example, the cross-linked polysulfonated polymer is sPPS, sPEEK, sPOP or sPBI. For example, the cross-linked polysulfonated polymer is sPPS or sPSU. For example, the cross-linked polysulfonated polymer is sPPS. The remainder of the features and exemplary features of the third aspect are as described above for the first and second aspects of the first embodiment.

[0084] The remainder of the features and example features of the fifteenth aspect are as described above in relation to the first through fourteenth aspects of the first embodiment.

[0085] In a sixteenth aspect of the first embodiment, the crosslinked polysulfonated polymer has the following structural formula: [ka] wherein R 1 , R 2 , R 3 and R 4 Each of these is independently H, C 1-12 Alkyl, C 1-12 Haloalkyl, C 6-14 Aryl and C 6-14 Aryl (C 1-12 alkylene); R5 is H or -SO 3 H and M 2+ Mr. 2+ , Ca 2+ , B.A. 2+ and Al(X) 2+ wherein X is a halide, acetate or nitrate; k is 1, 2, 3 or 4; [ka] represents the point of attachment of the crosslinking moiety to the repeating unit of the crosslinked polysulfonated polymer. For example, the crosslinking moiety may have the following structural formula: [ka] For example, the bridging moiety may be represented by one of the following structural formulas: [ka] For example, the bridging moiety may be represented by one of the following structural formulas: [ka] For example, the bridging moiety may be represented by one of the following structural formulas: [ka] For example, the bridging moiety may be represented by the following structural formula: [ka] For example, R 5 is H. For example, R 5 -SO 3 H. The remainder of the features and example features of the sixteenth aspect are as described above in relation to the first through fifteenth aspects of the first embodiment.

[0086] In a seventeenth aspect of the first embodiment, the crosslinked polysulfonated polymer comprises sPPS or sPSU, and the crosslinking moiety has the following structural formula: [ka] For example, the crosslinked polysulfonated polymer may include sPPS, the crosslinking moiety being represented by one of the following structural formulas: [ka] For example, the crosslinked polysulfonated polymer may include sPPS, the crosslinking moiety being represented by one of the following structural formulas: [ka] For example, the crosslinked polysulfonated polymer comprises sPPS, the crosslinking moiety being represented by the following structural formula: [ka] For example, the crosslinked polysulfonated polymer may include sPPS, the crosslinking moiety being represented by one of the following structural formulas: [ka] The remainder of the features and example features of the seventeenth aspect are as described above in relation to the first through sixteenth aspects of the first embodiment.

[0087] In an eighteenth aspect of the first embodiment, the crosslinked polysulfonated polymer comprises an average of about 0.5 to about 6 combined sulfonic acid, sulfonate, and sulfonamide groups per repeat unit. For example, the crosslinked polysulfonated polymer comprises an average of about 0.5 to about 2, about 1 to about 3, about 1.5 to about 2.5, about 2 to about 4, about 1.5 to about 3, or about 2 to about 1.5 combined sulfonic acid, sulfonate, and sulfonamide groups per repeat unit. For example, the crosslinked polysulfonated polymer comprises an average of about 0.5, about 1, about 1.5, about 2.0, about 2.5, or about 3 combined sulfonic acid, sulfonate, and sulfonamide groups per repeat unit. The remainder of the features and exemplary features of the eighteenth aspect are as described above with respect to the first to seventeenth aspects of the first embodiment.

[0088] In a nineteenth aspect of the first embodiment, the crosslinked polysulfonated polymer has a crosslinking degree of about 10% to about 95%. For example, the crosslinking degree of the crosslinked polysulfonated polymer is about 15% to about 90%, about 20% to about 80%, about 20% to about 70%, about 20% to about 60%, about 20% to about 50%, about 20% to about 45%, about 20% to about 40%, about 30% to about 50%, about 25% to about 30%, or about 30% to about 35%. For example, the degree of crosslinking of the crosslinked polysulfonated polymer is about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90% or about 95%. The remainder of the features and exemplary features of the nineteenth aspect are as described above with respect to the first through eighteenth aspects of the first embodiment.

[0089] In a twentieth aspect of the first embodiment, the membrane is unsupported, the crosslinked polysulfonated polymer is sPPS, and the crosslinking moieties have the following structural formula: [ka] The remainder of the features and example features of the twentieth aspect are as described above in relation to the first through nineteenth aspects of the first embodiment.

[0090] In a twenty-first aspect of the first embodiment, the membrane is unsupported, the crosslinked polysulfonated polymer is sPPS, and the crosslinking moieties have the following structural formula: [ka] The remainder of the features and example features of the twenty-first aspect are as described above with respect to the first through twentieth aspects of the first embodiment.

[0091] In a twenty-second aspect of the first embodiment, the PFSA has structural formula (I): [ka] wherein x is an integer from 5 to 14, m is 1 or 2, and n is 2 or 3; the crosslinked polysulfonated polymer comprises sPPS or sPSU, the crosslinking moiety being represented by the following structural formula: [ka] The remainder of the features and example features of the twenty-second aspect are as described above with respect to the first through twenty-first aspects of the first embodiment.

[0092] In a twenty-third aspect of the first embodiment, the membrane is unsupported and the PFSA has structural formula (I): [ka] wherein x is an integer from 5 to 14, m is 1 or 2, and n is 2 or 3; and wherein the crosslinked polysulfonated polymer is an sPPS, the crosslinked moiety having the following structural formula: [ka] wherein the degree of sulfonation of sPPS is about 200%, the degree of crosslinking of sPPS is about 40%, and the second layer has a thickness of about 0.5 μm to about 2 μm. The remainder of the features and example features of the twenty-third aspect are as described above for the first through twenty-second aspects of the first embodiment.

[0093] In a twenty-fourth aspect of the first embodiment, the membrane is unsupported and the PFSA has structural formula (I): [ka] wherein x is an integer from 5 to 14, m is 1 or 2, and n is 2 or 3; and wherein the crosslinked polysulfonated polymer is sPPS, the crosslinked moieties are represented by the structural formula: [ka] wherein the degree of sulfonation of the sPPS is about 200%, the degree of crosslinking of the sPPS is about 25% to about 30%, and the thickness of the second layer is about 1 μm to about 2 μm. The remainder of the features and example features of the twenty-fourth aspect are as described above for the first to twenty-third aspects of the first embodiment.

[0094] In a twenty-fifth aspect of the first embodiment, the first layer comprises a porous matrix comprising a matrix polymer, the PFSA and the matrix polymer forming an interpenetrating network, and the crosslinked polysulfonated polymer comprises sPPS or sPSU. For example, the crosslinked polysulfonated polymer is sPPS. For example, sPPS has the following structural formula: [ka] For example, the bridging moiety may be represented by one of the following structural formulas: [ka] For example, the bridging moiety may be represented by one of the following structural formulas: [ka] The remainder of the features and example features of the twenty-fifth aspect are as described above for the first through twenty-fourth aspects of the first embodiment.

[0095] In a second aspect, the present invention provides a method for producing a pharmaceutical composition comprising: a) providing a first layer having a first surface and a solution or suspension comprising a polysulfonated polymer and a cross-linking reagent; b) coating a first surface of a first layer with a solution or suspension, thereby producing a coated first layer; c) exposing the coated first layer to conditions sufficient for the polysulfonated polymer and the cross-linking reagent to undergo a cross-linking reaction, thereby producing a bilayer polymer electrolyte membrane. A method of making a bilayer polymer electrolyte membrane as described herein with respect to the first embodiment and various aspects thereof, comprising:

[0096] In a first aspect of the second embodiment, the cross-linking reagent is selected from a polyalcohol, an amine, an epoxide, a thiol, or a compound containing a terminal alkene or alkyne. For example, the cross-linking reagent is selected from glycerol, ethylene glycol, hydroquinone, 2,5-dihydroxybenzenesulfonic acid, 2,5-dihydroxybenzene-1,4-disulfonic acid, biphenyl, tetraglycidyl bis(p-aminophenyl)methane, phenylenediamine, 4,4'-thiobisbenzenethiol, and tetrafluorostyrene. For example, the cross-linking reagent is glycerol, ethylene glycol, hydroquinone, or 2,5-dihydroxybenzenesulfonic acid. For example, the cross-linking reagent is a polyalcohol, such as glycerol or ethylene glycol. For example, the cross-linking reagent is hydroquinone or 2,5-dihydroxybenzenesulfonic acid. The cross-linking reagent can be selected from glycerol, ethylene glycol, tetraglycidyl bis(p-aminophenyl)methane, phenylenediamine, 4,4'-thiobisbenzenethiol, and tetrafluorostyrene.

[0097] In a second aspect of the second embodiment, the conditions sufficient for the polysulfonated polymer and the crosslinking reagent to undergo a crosslinking reaction include heating the coated first layer to a crosslinking temperature of about 150°C to about 200°C for a crosslinking time of about 2 hours to about 96 hours. For example, the crosslinking temperature is about 150°C, about 160°C, about 170°C, about 180°C, about 190°C, or about 200°C. For example, the crosslinking temperature is approximately about 180°C and the crosslinking time is about 4 hours. For example, the crosslinking time is about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 20 hours, about 30 hours, about 40 hours, about 50 hours, about 60 hours, about 70 hours, about 80 hours, or about 90 hours. For example, the crosslinking time is about 4 hours. The remainder of the features and exemplary features of the second aspect are as described above for the first aspect of the second embodiment.

[0098] In a second aspect of the second embodiment, coating the first surface of the first layer with the first solution or suspension comprises spray coating the first surface of the first layer with the first solution or suspension. Alternatively, coating the first surface of the first layer with the first solution or suspension comprises dip coating, spin coating or flow coating the first surface of the first layer with the first solution or suspension. The remainder of the features and exemplary features of the third aspect are as described above with respect to the first and second aspects of the second embodiment.

[0099] In a third aspect, the invention is a membrane electrode assembly (MEA) comprising a bilayer polymer electrolyte membrane as described herein with respect to the first aspect and various aspects thereof; a cathode; and an anode, wherein the bilayer electrolyte membrane is disposed between the anode and the cathode.

[0100] In a first aspect of the third embodiment, the cathode is disposed on the first layer of the bilayer electrolyte membrane and the anode is disposed on the second layer of the bilayer electrolyte membrane. Alternatively, the anode is disposed on the first layer of the bilayer electrolyte membrane and the cathode is disposed on the second layer of the bilayer electrolyte membrane.

[0101] In a fourth aspect, the invention is a fuel cell comprising one or more of the MEAs described herein with respect to the third aspect and various aspects thereof, and one or more gas flow bipolar plates.

[0102] In various aspects, the present invention provides a method for producing a method for treating a cancer cell comprising: 1. A bilayer polymer electrolyte membrane comprising a first layer and a second layer, the first layer comprises perfluorosulfonic acid (PFSA); the second layer comprises a crosslinked polysulfonated polymer comprising sulfonated polyphenylsulfone (sPPS), sulfonated polyetheretherketone (sPEEK), sulfonated polyphosphazene (sPOP), sulfonated polybenzimidazole (sPBI), sulfonated polyethersulfone (sPES), sulfonated polyphenylene oxide (sPPO), sulfonated polyaryleneetherketone (sPAEK), sulfonated poly(sulfone), sulfonated poly(sulfide sulfone), sulfonated polyimide (sPI), sulfonated poly(etherimide) (sPEI), sulfonated poly(amine), or a combination thereof; A bilayer polymer electrolyte membrane, in which a first layer is disposed on a second layer. 2. The PFSA has structural formula (I): [ka] A polymer comprising a repeat unit represented by During the ceremony, x is an integer from 1 to 15; m is an integer from 0 to 2; n is an integer from 1 to 5; [ka] 2. The bilayer polymer electrolyte membrane of claim 1, wherein represents a point of attachment to an adjacent repeat unit. 3. x is an integer between 5 and 14; m is 1 or 2, 3. The bilayer polymer electrolyte membrane of claim 2, wherein n is 2 or 3. 4. The bilayer polymer electrolyte membrane according to claim 2 or 3, wherein the PFSA is a polymer containing about 900 to about 1100 repeating units represented by structural formula (I). 5. The bilayer polymer electrolyte membrane of any one of claims 1 to 4, wherein the crosslinked polysulfonated polymer comprises sPPS, sPEEK, sPOP or sPBI. 6. The bilayer polymer electrolyte membrane of claim 5, wherein the crosslinked polysulfonated polymer comprises sPPS. 7. The crosslinked polysulfonated polymer has the following structural formula: [ka] and a bridging moiety represented by one of the following: During the ceremony, R 1 , R 2 , R 3 and R 4 Each of these is independent of H, C 1-12 Alkyl, C 1-12 Haloalkyl, C 6-14 Aryl and C 6-14 Aryl (C 1-12 alkylene); M 2+ Mr. 2+ , Ca 2+ , B.A. 2+ and Al(X) 2+ wherein X is a halide, acetate or nitrate; [ka] 7. The bilayer polymer electrolyte membrane of claim 1, wherein represents the point of attachment of the crosslinked moiety to the repeat unit of the crosslinked polysulfonated polymer. 8. The bridging moiety has the following structural formula: [ka] 8. The bilayer polymer electrolyte membrane of claim 7, wherein the bilayer polymer electrolyte membrane is represented by one of the following formulas: 9. The bridging moiety has the following structural formula: [ka] 8. The bilayer polymer electrolyte membrane of claim 7, wherein the bilayer polymer electrolyte membrane is represented by one of the following formulas: 10. The bilayer polymer electrolyte membrane of any one of claims 1-9, wherein the first layer further comprises a porous matrix comprising a matrix polymer, and the PFSA and the matrix polymer form an interpenetrating network. 11. The bilayer polymer electrolyte membrane of claim 10, wherein the first layer comprises about 70 wt.% to about 99 wt.% PFSA. 12. The bilayer polymer electrolyte membrane of claim 10, wherein the first layer comprises about 78 wt.% to about 95 wt.% PFSA. 13. The bilayer polymer electrolyte membrane according to any one of claims 10 to 12, wherein the matrix polymer is polytetrafluoroethylene (PTFE). 14. The bilayer polymer electrolyte membrane of claim 13, wherein the matrix polymer is expanded polytetrafluoroethylene (ePTFE). 15. The bilayer polymer electrolyte membrane according to any one of claims 1 to 14, wherein the crosslinked polysulfonated polymer has a degree of sulfonation of about 20% to about 100%. 16. The bilayer polymer electrolyte membrane according to claim 15, wherein the crosslinked polysulfonated polymer has a degree of sulfonation of about 40% to about 80%. 17. The bilayer polymer electrolyte membrane according to claim 15, wherein the crosslinked polysulfonated polymer has a degree of sulfonation of about 50% to about 60%. 18. The bilayer polymer electrolyte membrane according to any one of claims 1 to 17, wherein the gel fraction of the crosslinked polysulfonated polymer is from about 50% to about 100%. 19. The bilayer polymer electrolyte membrane according to any one of claims 1 to 18, wherein the first layer has a thickness of about 5 µm to about 175 µm. 20. The bilayer polymer electrolyte membrane according to any one of claims 1 to 19, wherein the second layer has a thickness of about 0.2 µm to about 170 µm. 21. The bilayer polymer electrolyte membrane of claim 20, wherein the second layer has a thickness of about 0.2 μm to about 10 μm. 22. The bilayer polymer electrolyte membrane of any one of claims 1 to 21, wherein the first layer is continuous. 23. The bilayer polymer electrolyte membrane of any one of claims 1 to 22, wherein the membrane is unsupported. 24. The PFSA has structural formula (I): [ka] A polymer comprising a repeating unit represented by During the ceremony, x is an integer from 5 to 14; m is 1 or 2, n is 2 or 3; The crosslinked polysulfonated polymer comprises sPPS and the following structural formula: [ka] 2. The bilayer polymer electrolyte membrane of claim 1, comprising a cross-linking moiety represented by one of: 25. The first layer comprises a porous matrix including a matrix polymer, wherein the PFSA and the matrix polymer form an interpenetrating network; PFSA has structural formula (I): [ka] A polymer comprising a repeat unit represented by During the ceremony, x is an integer from 5 to 14; m is 1 or 2, n is 2 or 3; the matrix polymer comprises ePTFE; The crosslinked polysulfonated polymer comprises sPPS and the following structural formula: [ka] 2. The bilayer polymer electrolyte membrane of claim 1, comprising a cross-linking moiety represented by one of: 26. a) providing a first layer having a first surface and a solution or suspension comprising a polysulfonated polymer and a cross-linking reagent; b) coating a first surface of a first layer with a solution or suspension, thereby producing a coated first layer; c) exposing the coated first layer to conditions sufficient for the polysulfonated polymer and the cross-linking reagent to undergo a cross-linking reaction, thereby producing a bilayer polymer electrolyte membrane. 26. A method for producing the bilayer polymer electrolyte membrane according to claim 1, comprising: 27. The method of claim 26, wherein the cross-linking reagent is selected from a polyalcohol, an amine, an epoxide, a thiol, or a compound containing a terminal alkene or alkyne. 28. The method of claim 26, wherein the cross-linking reagent is selected from glycerol, ethylene glycol, tetraglycidylbis(p-aminophenyl)methane, phenylenediamine, 4,4'-thiobisbenzenethiol, and tetrafluorostyrene. 29. The method of claim 26, wherein the cross-linking reagent is a polyalcohol. 30. The method of claim 29, wherein the cross-linking reagent is ethylene glycol or glycerol. 31. The method of any one of claims 26-30, wherein the conditions sufficient for the polysulfonated polymer and the cross-linking reagent to undergo a cross-linking reaction include heating the coated first layer to a cross-linking temperature of about 150°C to about 200°C for a cross-linking time of about 2 hours to about 96 hours. 32. The method of claim 31, wherein the crosslinking temperature is about 180°C. 33. The method of claim 31, wherein the crosslinking time is about 4 hours. 34. The method of any one of claims 26-33, wherein coating the first surface of the first layer with the first solution or suspension comprises spray coating the first surface of the first layer with the first solution or suspension. 35. The bilayer polymer electrolyte membrane according to any one of claims 1 to 25; cathode; and anode A membrane electrode assembly (MEA) comprising: A bilayer electrolyte membrane is placed between the anode and cathode, the MEA. 36. The MEA of claim 35, wherein the cathode is disposed on a first layer of the bilayer electrolyte membrane and the anode is disposed on a second layer of the bilayer electrolyte membrane. 37. The MEA of claim 35, wherein the anode is disposed on a first layer of the bilayer electrolyte membrane and the cathode is disposed on a second layer of the bilayer electrolyte membrane. 38. A fuel cell comprising one or more MEAs according to any one of claims 35 to 37 and one or more gas flow bipolar plates. EXAMPLES

[0103] Working Example material PPS (Solvay Radel R-5000, MW=5000) was purchased from Solvay. 2 SO 4 ) was purchased from Sigma-Aldrich (95-98%, CAS 7664-93-9). Ethylene glycol was purchased from Sigma-Aldrich (≥99%, CAS 107-21-1). Nafion® 211 PFSA membrane (NR-211) was purchased from Fuel Cell Store.

[0104] Example 1. Sulfonation of PPS. General procedure: Polymer is 2 SO 4 PPS was sulfonated by reacting with concentrated H 2 SO 4 The reaction mixture was stirred at 60-70°C for 10-48 hours. 2 The sulfonated polymer was precipitated by dropping it into 2024 H2O. The resulting precipitated polymer was isolated by centrifugation. The sulfonated PPS (sPPS) was stirred at room temperature for 2 hours at 4°C for 1 hour. 2 The sPPS was redispersed in 0 and washed using dialysis until a neutral pH was recorded. The washed sPPS was dried on a hot plate to obtain the final product. The sulfonation degree of sPPS can be adjusted by adjusting the reaction time (1-72 hr).

[0105] Example synthesis: Polymer and H 2 SO 4 PPS (Radel-5000 NT) was sulfonated by reacting with . The PPS resin was ground into powder using an industrial grinder. The PPS powder (20 g) was dissolved in concentrated H2SO4 at a concentration of 25 mg / mL. 2 SO 4 The reaction mixture was stirred at 60° C. for 8 hours. 2 The resulting sulfonated polymer was precipitated by dropping it into 2024. The resulting precipitated polymer was isolated by centrifugation. The sulfonated PPS (sPPS) was stirred at room temperature for 2 hours at 37°C. 20 and washed using dialysis until a neutral pH was recorded. The washed sPPS was dried on a hot plate to obtain the final product. The yield of the reaction was determined to be 91% by weight. When measured according to the procedure described in Example 3, the resulting product had a titration determined IEC of 3.605 meq / g (corresponding to 2.0 sulfonic acid per repeat unit).

[0106] Sulfonated polymer 1 1 H NMR was measured at a concentration of about 10 wt.% in DMSO-d6 to confirm the polymer structure and the degree of sulfonation. 1 H NMR spectra were acquired using a 500 MHz Bruker Ultrashield 500 Plus Spectrometer and processed using SpinWorks 4. A pulse angle of 30° and a pulse delay of 5 s with 32 scans were used. 1 H NMR experiments were performed. 1 The H NMR spectrum is shown in Figure 16. The integration of the peaks as shown below in Table 1 was used to establish the number and position of sulfonic acid groups in the repeat unit as shown in Figure 16. [Table 2]

[0107] The peaks were integrated and normalized by setting the peak integral of peak B to a value of 4, which is the number of B-site protons per repeat unit (Table 1). The identity of peak B is assigned based on the steric and electronic protection of the B site from sulfonation due to the presence of sulfone bonds. The number of sulfonic acid moieties per repeat unit was calculated by the ratio of the peak integral with peak C. Furthermore, the IEC value was calculated based on the peak integral values ​​as follows: The value of IEC is related to the weight of material per sulfonic acid moiety. This is known as the effective weight (EW). Since the prepared sPPS has a monopolymer backbone, the ratio of the C peak integral with any hydrogen peak (adapted for the number of sulfonic acid groups in the structure) was used to calculate the effective weight (EW) of the material per sulfonic acid moiety, using the following formula:

number

[0108] The number of sulfonic acid moieties per repeating unit is determined according to the following formula:

number

number

number

[0109] sPPS 1 The obtained and average numbers for IEC, based on each of the integrated peaks in the H NMR spectrum, align well with the experimental IEC values ​​obtained by titration (see Table 1). This alignment indicates that there are no other significant sulfonation positions on the repeat unit and that sPPS contains two sulfonic acid moieties per repeat unit, located on the biphenyl portion of the backbone as shown in FIG.

[0110] Example 2. Casting of free-standing sPPS membranes. A solution of 1-5 wt.% sPPS in an ethylene glycol:water mixture was added to a Kapton trough. The solution was allowed to dry overnight. The dried sPPS film was crosslinked via a condensation reaction with the remaining ethylene glycol by heating to 180 °C under flowing nitrogen for 4 h to achieve a water-stable sPPS polymer film.

[0111] Example 3. Determination of ion exchange capacity and degree of cross-linking. The ion exchange capacity (IEC) of sPPS polymers and crosslinked sPPS membranes was measured by titration. Pieces of polymer or membrane were dried in an oven under flowing nitrogen at 100° C. for 12 hours and then weighed to determine the mass of the material (W 乾燥 The dried material was immersed in 20 mL of 2 M NaCl for 30 min, after which 10 μL of phenolphthalein was added. A standardized solution of NaOH (C NaOH The volume of NaOH solution added (V NaOH ) was recorded. The IEC was then calculated as follows:

number

[0112] The degree of crosslinking (%) is defined as the fraction of sulfonic acid moieties that react with crosslinker molecules. The degree of crosslinking was calculated as follows:

number

[0113] Example 4. Conductivity measurements of free-standing membranes. Membrane conductivity was measured in a four-point probe geometry using an Admiral Squidstat potentiostat in a Scribner Bekktech BT-112 HT conductivity cell. Conductivity was assessed by current measurement during linear sweep voltammetry from -0.5 V to 0.5 V. Conductivity was then calculated from the current-voltage slope using the sample thickness.

[0114] Upon cross-linking of sPPS materials, the loss of proton concentration results in a non-linear decrease in membrane conductivity. The relationship between conductivity and degree of cross-linking is shown in Figure 9.

[0115] Example 5. Spray coating of Nafion® membrane with sPPS and ethylene glycol as crosslinker. The sPPS was deposited onto the Nafion® membrane using a Sono-tek ExactaCoat coating system. 2 The mixture consisted of 0.5 wt.% or 0.75 wt.% sPPS in O and varying amounts of crosslinker (ethylene glycol or glycerol). In the case of ethylene glycol, 6 molecules of ethylene glycol were added per repeat unit of the polymer. The solution was stirred for 30-60 min before use. The Nafion® membrane substrate was kept under vacuum during deposition. The following parameters were used for spray coating: power 0.8-1.3 W, nozzle height 40 mm, temperature 60 °C, flow rate 0.25-0.5 mL / min. The number of polymer layers was adjusted for the desired coating thickness. 75 layers were deposited to achieve a 1.5 μm thick sPPS coating, and 38 layers were deposited to achieve a 0.75 μm thickness. The following ranges for spray coating parameters may be used: sPPS solution concentration: 0.05-20 wt.%; substrate temperature: 5-200 °C; nozzle height: 10-70 mm; flow rate: 0.1-4 mL / min; power: 0.8-5 W; crosslinker amount (specific for ethylene glycol and glycerol): 0.2-12 molecules / repeating unit of sPPS.

[0116] Example 6. Crosslinking of sPPS coatings on Nafion® membranes. The sPPS coatings on Nafion® membranes were crosslinked using ethylene glycol or glycerol. To effect crosslinking, the sPPS-coated Nafion® membranes were heated to 180°C under flowing nitrogen while held under tension by tape against an aluminum mask for either 4 hours or as a series of temperature steps over 4 days to achieve a water-stable sPPS polymer coating. The resulting coatings had a degree of crosslinking of 30-50%.

[0117] Example 7. Preparation of membrane electrode assembly. The bilayer polymer electrolyte membrane was used in a membrane electrode assembly (MEA) with a 5 cm 2For MEA preparation, a 3" x 3" membrane was prepared by pre-coating 0.2 mg Pt / cm on Sigracet 22 BB. 2 The electrode was placed between two gas diffusion electrodes (GDEs) with a thickness of 5 cm (20% Pt on Vulcan carbon). 2 The GDE had an area of ​​5 cm. The GDE was implemented with a catalyst layer pre-deposited on the side of the microporous layer and interfacing the membrane. 2 A 3"x3" PTFE gasket with a window was placed on each side of the membrane to encompass the gas diffusion electrodes to prevent leakage of reactant gases. The gasket thickness is adjusted to allow for 80% compression of the GDE when the MEA is clamped between the two fuel cell end plates.

[0118] Example 8. Testing of bilayer polymer electrolyte membranes in fuel cells. H 2 The membrane performance was evaluated in fuel cells by crossover measurements, fuel cell polarization curves and accelerated stress tests.

[0119] H 2 Crossover Measurement H 2 The crossover was measured by performing cyclic voltammetry, where the cathodic electrode was scanned between 0.1 V and 0.8 V using a voltage scan rate of 2 mV / s at 80 °C and 100% RH, and 0.4 lpm H on the anodic electrode. 2 The fuel cell polarization curves were measured at 80°C and various RH values ​​by performing constant voltage measurements from open circuit potential to 0.3V and back to open circuit potential at 0.5V increments between open circuit potential to 0.7V and 1V increments between 0.7V and 0.3V, and with 0.2 lpm H on the anode side. 2 Flow and 0.2 lpm air or O on the cathode surface 2 Flow is 50kPa gThe back pressure was 1.33 mA / cm. The data obtained is shown in Figures 4 and 10. The membrane tested was coated with sPPS with a crosslinking degree of 40%. The data shows that the hydrogen crossover was 1.33 mA / cm. 2 (0μm coating) to 1.05mA / cm 2 (0.75μm coating), 0.84mA / cm 2 (1.5 μm coating), thus demonstrating that the low gas permeable coating reduces hydrogen crossover through the PFSA-based membrane.

[0120] Electrochemical Impedance Spectroscopy Electrochemical impedance spectroscopy is 2 75mA / cm in pump mode 2 Using an excitation amplitude of 150 mA / cm 2 The measurements were performed at 80°C and 100% RH with 0.05 lpm H 2 flow and 0.05 lpm Ar flow on the cathode side had no back pressure.

[0121] The data in FIG. 15 unexpectedly show that in bilayer membranes containing Nafion® 211 and crosslinked sPPS, the sPPS and Nafion® layers exhibit no contact resistance between each other, meaning that protons do not experience excessive resistance by moving between the layers. Contact resistance between hetero-materials is frequently observed in conductive systems and presents a significant barrier to layered geometries. Therefore, bilayer systems containing two materials layered on top of each other are expected to show reduced ionic conductivity due to interface / contact resistance. To evaluate contact resistance in bilayer membranes, the area specific resistance (ASR) of a 25 μm Nafion® 211 membrane, a 1.5 μm 40% crosslinked sPPS membrane, and a bilayer membrane (25 μm Nafion® 211 with a 1.5 μm 40% crosslinked sPPS coating) was measured in a single cell fuel cell. Surprisingly, the ASR of the two-layer system was approximately equal to the sum of the ASR values ​​of the individual layers.

[0122] Accelerated Stress Test (AST) AST was performed under one of the following protocols: Protocol A: AST included an aggressive strenuous phase and a cyclic hydration phase, the duration of each phase reaching 4.5 h and 0.5 h, respectively. During the aggressive strenuous phase, the cell was set at 110° C. and 0.1 lpm H on the anode. 2 Flow and 0.1 lpm O on cathode 2 The flow had no back pressure and both gases were at 30% RH. During the hydration step the cell was set at 80° C. and 0.1 lpm H on the anode. 2 Flow and 0.1 lpm O on cathode 2 The flow had no back pressure and both gases were at 100% RH. The results of the test are shown in Figure 6.

[0123] Protocol B: AST was performed by applying a RH cycle switching the gas between 0 and 100% RH at 2 min intervals while keeping the cell open circuit. The cell was held at 90 °C and 0.1 lpm H on the anode. 2 The flow and 0.1 lpm air flow over the cathode had no back pressure. 2 Crossover was measured and discharged water was collected periodically during the accelerated stress test, and the results of the test are shown in Figures 11 and 12.

[0124] The data in Figure 11 shows that Nafion® 211 membranes with increasing cross-linked sPPS coating thickness exhibit improved durability. It can be seen that the increase in durability with thicker coatings is disproportionately large when compared to the overall membrane thickness change. Specifically, Nafion® 211 (25 μm) with a 1.5 μm 40% cross-linked sPPS coating withstands the test conditions for three times longer than that for Nafion® 211, despite being only 6% thicker.

[0125] The data in Figure 12 confirm that the Nafion® 211 membrane with the thicker cross-linked sPPS coating (40% cross-linked) exhibits substantially higher durability. Furthermore, the H 2 The increase in crossover occurs significantly more slowly compared to the rapid deterioration of hydrogen crossover in membranes with thinner or no coatings. The gradual film deterioration observed near the end of life in membranes with thicker coatings was unexpected and allows for improved safety features in hydrogen devices to prevent catastrophic decomposition at the end of life.

[0126] The data in FIG. 12 further shows that the bilayer membranes including Nafion® 211 and crosslinked sPPS coating are more durable compared to the single layer Nafion® 211 membrane and the crosslinked sPPS membrane alone. The crosslinked sPPS membrane has a fuel cell durability of less than 100 hours (see, for example, Kim JD et al., “Chemically Crosslinked Sulfonated Polyphenylsulfone (CSPPSU) Membranes for PEM Fuel Cells”, Membranes, 10(2):31 (2020)). Similarly, Nafion® 211 shows an AST durability significantly less than 100 hours (FIG. 12). Surprisingly, the bilayer membranes including the Nafion® 211 base layer with a 1.5 μm 40% crosslinked sPPS coating show a durability substantially at least 3 times longer than either of the component materials (FIG. 12).

[0127] Example 9. Evaluation of the water stability of crosslinked sPPS membranes. The water stability of the coating material before and after crosslinking was evaluated by cyclically drying the membrane at 80 °C for 12 h and recovering the mass before immersion in refluxing water for 20-25 h. As synthesized, the sPPS free-standing membranes were highly soluble in water. Non-crosslinked sPPS membranes immersed in boiling water immediately and completely dissolve. After the ethylene glycol crosslinking procedure, the 40% crosslinked sPPS free-standing membranes showed excellent stability to boiling water, with less than 3% weight loss after 120 h. The results of the test are shown in Figure 8.

[0128] Example 10. Testing of coated PFSA membranes containing various PFSA layers. PFSA-based membranes of various thicknesses from multiple suppliers (supported Aquivion® (20 μm thick) and Nafion® 211 (25 μm thick) with crosslinked sPPS coating (1.5 μm coating with 40% crosslinking degree)) were tested. When operated in a single cell fuel cell, the coated membranes showed full functionality as proton exchange membranes (see FIG. 13). Furthermore, hydrogen crossover for the coated membranes was substantially reduced compared to the uncoated baseline (FIG. 14). The data showed that the approach of coating the PFSA layer with a layer of crosslinked sulfonated polymer is applicable to all major PFSA-based commercial membranes and allows for a significant increase in fuel cell power density while simultaneously reducing hydrogen crossover.

[0129] Example 11. Evaluation of swelling and delamination in membranes. The membranes were evaluated for dimensional stability by measuring the membrane size and thickness using a ruler and micrometer, soaking the membrane in 80°C water for 1 hour, and measuring its size and thickness again after soaking in 80°C water. Nafion® 211 showed a substantially different degree of swelling (28-33%) in 80°C water compared to free-standing 40% cross-linked sPPS (147-209%), free-standing 90% cross-linked sPSU (0%), and free-standing 90% cross-linked sPPO (8%). The large disparity in material swelling was expected to cause significant delamination of the layers in the coated bilayer system. However, bilayer membranes containing a 1.5 μm polysulfonated polymer layer and a 25 μm Nafion® 211 layer did not delaminate after 1 hour exposure to 80°C water. Instead, the swelling characteristics closely matched these Nafion® 211 membranes for sPPS and sPSU (see Table 2). Furthermore, no evidence of delamination of the bilayer was seen during AST evaluation, which involved repeatedly hydrating and dehydrating the membrane in cycles. [Table 3]

[0130] Without wishing to be bound by any particular theory, it is believed that the claimed polymers of the present disclosure exhibit unexpected performance in bilayer membranes as a result of the polymer backbone containing moieties with nucleophilic lone pairs and moieties with electrophilic aromatic rings. The nucleophilic lone pairs exhibit electrostatic attraction to protons on the sulfonic acid moieties of the PFSA surface, while the electrophilic aromatic rings exhibit electrostatic attraction to deprotonated sulfonic acid moieties (sulfonate moieties) on the PFSA surface. In a representative number of the claimed polymers, these electrostatic interactions have surprisingly been shown to be sufficient to overcome the mechanical forces caused by the significant mismatched swelling between the layers and prevent delamination of the layers.

[0131] Example 12. Preparation of a bilayer membrane comprising a layer of Nafion® 211 coated with sPPS crosslinked with hydroquinone Spray coating of sPPS and hydroquinone solution onto Nafion® membrane. The sPPS was deposited onto a Nafion® membrane using a Sono-tek ExactaCoat coating system. The spray solution was 2 A solution was prepared with 0.75 wt.% sPPS and 0.19 wt.% hydroquinone in O (1.3 hydroquinone molecules per sPPS repeat unit). The solution was stirred for 30-60 min before use. The Nafion® membrane substrate was held under vacuum during deposition. The following parameters were used for spray coating: power 0.8-1.3 W, nozzle height 40 mm, temperature 60° C., flow rate 0.25-0.5 mL / min. The number of polymer layers was adjusted for the desired coating thickness. 75 layers were deposited to achieve a 1.5 μm thick sPPS coating. The following ranges for spray coating parameters may be used: sPPS solution concentration: 0.05-15 wt.%; substrate temperature: 20-200° C.; nozzle height: 10-70 mm; flow rate: 0.1-4 mL / min; power: 0.8-5 W; crosslinker amount: 0.1-4 molecules / repeat unit of sPPS.

[0132] Crosslinking of sPPS coatings onto Nafion® membranes. The sPPS coating on the Nafion® membrane was crosslinked using hydroquinone. To effect crosslinking, the sPPS coated Nafion® membrane was heated to 200°C for 2 hours under flowing nitrogen while held under tension by tape against an aluminum mask to achieve a water-stable sPPS polymer coating. The resulting coating was 25-30% crosslinked.

[0133] Example 13. Preparation of a bilayer membrane comprising a layer of Nafion® 211 coated with sPPS crosslinked with 2,5-dihydroxybenzenesulfonic acid Spray coating of Nafion® membrane with sPPS and 2,5-dihydroxybenzenesulfonic acid solution. The sPPS was deposited onto the Nafion® membrane using a Sono-tek ExactaCoat coating system. 2 The solution was prepared with 0.75 wt.% sPPS and 0.39 wt.% potassium salt of 2,5-dihydroxybenzenesulfonic acid (1.3 molecules of potassium salt of 2,5-dihydroxybenzenesulfonic acid per sPPS repeat unit) in O. The solution was stirred for 30-60 min. The Nafion® membrane substrate was kept under vacuum during deposition. The following parameters were used for spray coating: power 0.8-1.3 W, nozzle height 40 mm, temperature 60° C., flow rate 0.25-0.5 mL / min. The number of polymer layers was adjusted for the desired coating thickness. 75 layers were deposited to achieve a 1.5 μm thick sPPS coating. The following ranges for spray coating parameters may be used: sPPS solution concentration: 0.05-15 wt.%; substrate temperature: 20-200° C.; nozzle height: 10-70 mm; flow rate: 0.1-4 mL / min; power: 0.8-5 W; crosslinker amount: 0.1-4 molecules / repeat unit of sPPS.

[0134] Crosslinking of sPPS coatings on Nafion® membranes. The sPPS coating on the Nafion® membrane was a crosslinked potassium salt of 2,5-dihydroxybenzenesulfonic acid. To effect crosslinking, the sPPS coated Nafion® membrane was heated to 200°C for 2 hours under flowing nitrogen while held under tension by tape against an aluminum mask to achieve a water stable sPPS polymer coating. The resulting coating was 25-30% crosslinked.

[0135] Acidification of 2,5-dihydroxybenzenesulfonic acid-crosslinked sPPS The crosslinked membrane was treated with 1 M aqueous HCl at 25 °C for 1 h. The membrane was removed from the HCl solution and rinsed with DI water 3-4 times until the effluent water remained neutral. The membrane was then dried at 25 °C.

[0136] Example 14. Preparation of a bilayer membrane comprising a layer of Nafion® 211 coated with sPPS crosslinked with biphenyl Spray coating of sPPS and biphenyl solutions onto Nafion® membrane. sPPS was deposited onto Nafion® membranes using a Sono-tek ExactaCoat coating system. Spray solutions were prepared at 0.75 wt.% sPPS and 0.2 wt.% biphenyl (one biphenyl molecule per sPPS repeat unit) in ethanol. The solutions were stirred for 30-60 min before use. The Nafion® membrane substrate was held under vacuum during deposition. The following parameters were used for spray coating: power 0.8-1.3 W, nozzle height 40 mm, temperature 60° C., flow rate 0.25-0.5 mL / min. The number of polymer layers was adjusted for the desired coating thickness. 75 layers were deposited to achieve a 1.5 μm thick sPPS coating. The following ranges for spray coating parameters may be used: sPPS solution concentration: 0.05-15 wt.%; substrate temperature: 20-200°C; nozzle height: 10-70 mm; flow rate: 0.1-4 mL / min; power: 0.8-5 W; crosslinker amount: 0.1-4 molecules / repeat unit of sPPS.

[0137] Crosslinking of sPPS coatings to Nafion® membranes. The sPPS coating on the Nafion® membrane was crosslinked using biphenyl. To effect crosslinking, the sPPS coated Nafion® membrane was heated to 200°C for 2 hours under flowing nitrogen while held under tension by tape against an aluminum mask to achieve a water stable sPPS polymer coating. The resulting coating was 30-35% crosslinked.

[0138] The properties of sPPS coated membranes prepared with different crosslinkers according to Examples 6 and 12-14 were tested. Fuel cell polarization and power curves of the bilayer membrane and uncoated Nafion® 211 show that all tested membranes function well as proton exchange membranes (FIG. 17).

[0139] H carried out according to Example 8 2 Crossover studies showed that sPPS, as well as bilayers prepared with biphenyl, hydroquinone, and 2,5-dihydroxybenzenesulfonic acid, crosslinked H as efficiently or better than sPPS crosslinked with ethylene glycol. 2 The crossover reduction in Nafion® 211 shown in FIG. 2 Crossover comparison was performed for sPPS-based bilayers crosslinked with all tested crosslinkers. 2 Showing significant improvement in crossover.

[0140] Example 15. Preparation of a bilayer membrane comprising a layer of Nafion® 211 coated with sPSU crosslinked with hydroquinone Sulfonation of PSU PSU is a polymer and H 2 SO 4 The PSU resin was ground into a powder using an industrial grinder. 20 mL of concentrated sulfuric acid was heated to 60° C. under mechanical stirring. Once the sulfuric acid reached 60° C., 2 g of ground sPSU was added. Once the sPSU was dissolved, the reaction was allowed to proceed for 8 hours at 60° C. with stirring. The reaction mixture was then cooled to 50° C. for 1 hour. 2 The sulfonated polymer was precipitated by dropwise addition of 100 mL of 1.0% ethanol at 0° C. The resulting precipitated polymer was isolated by centrifugation. The sulfonated PSU (sPSU) was precipitated by 100 mL of 1.0% ethanol at room temperature. 2 The sPPS was redispersed in 0 and washed using dialysis until a neutral pH was recorded. The washed sPPS was dried on a hot plate to give the final product.

[0141] Spray coating of Nafion® membrane with sPSU and hydroquinone solution. The sPSU was deposited onto the Nafion® membrane using a Sono-tek ExactaCoat coating system. The spray solution was 2A solution was prepared with 0.75 wt.% sPSU and 0.177 wt.% hydroquinone in O (1.3 hydroquinone molecules per sPSU repeat unit). The solution was stirred for 30-60 min before use. The Nafion® membrane substrate was held under vacuum during deposition. The following parameters were used for spray coating: power 0.8-1.3 W, nozzle height 40 mm, temperature 60° C., flow rate 0.25-0.5 mL / min. The number of polymer layers was adjusted for the desired coating thickness. 75 layers were deposited to achieve a 1.5 μm thick sPPS coating. The following ranges for spray coating parameters may be used: sPSU solution concentration: 0.05-15 wt.%; substrate temperature: 20-200° C.; nozzle height: 10-70 mm; flow rate: 0.1-4 mL / min; power: 0.8-5 W; crosslinker amount: 0-4 molecules / repeat unit of sPSU.

[0142] Crosslinking of sPSU coatings on Nafion® membranes. The sPSU coating on the Nafion® membrane was crosslinked using hydroquinone. To effect crosslinking, the sPSU-coated Nafion® membrane was heated to 200° C. for 2 hours under flowing nitrogen while held under tension by tape against an aluminum mask to achieve a water-stable sPSU polymer coating. The resulting coating was 90% crosslinked.

[0143] Example 16. Preparation of a bilayer membrane comprising a layer of Nafion® 211 coated with sPPO crosslinked with hydroquinone Sulfonation of PPO PPO was dissolved in chloroform at a concentration of 100 mg / mL under nitrogen purge. The PPO in chloroform was allowed to stir in an ice bath (0° C.) for 30 minutes prior to sulfonation. Chlorosulfonic acid was added dropwise to the PPO solution in a 1:1 molar ratio with PPO. The reaction was allowed to proceed for 30 minutes and then terminated by the addition of DI water. The sulfonated PPO (sPPO) was dissolved in H 22O and washed using dialysis until a neutral pH was recorded. The washed sPPO was dried on a hot plate to obtain the final product.

[0144] Spray coating of Nafion® membrane with sPPO and hydroquinone solution. sPPO was deposited onto a Nafion® membrane using a Sono-tek ExactaCoat coating system. The spray solution was 1:1 H 2 O: Prepared with 0.75 wt.% sPPO and 0.385 wt.% or 0.077 wt.% hydroquinone (0.5 or 0.1 hydroquinone molecule per sPPO repeat unit) in ethanol solution. The solution was stirred for 30-60 min before use. The Nafion® membrane substrate was kept under vacuum during deposition. The following parameters were used for spray coating: power 0.8-1.3 W, nozzle height 40 mm, temperature 60° C., flow rate 0.25-0.5 mL / min. The number of polymer layers was adjusted for the desired coating thickness. 75 layers were deposited to achieve a 1.5 μm thick sPPS coating. The following ranges for spray coating parameters may be used: sPPS solution concentration: 0.05-15 wt.%; substrate temperature: 20-200°C; nozzle height: 10-70 mm; flow rate: 0.1-4 mL / min; power: 0.8-5 W; crosslinker amount: 0.05-4 molecules / repeat unit of sPPO.

[0145] Crosslinking of sPPO coatings on Nafion® membranes. The sPPO coating on the Nafion® membrane was crosslinked using hydroquinone. To effect crosslinking, the sPPO-coated Nafion® membrane was heated to 200° C. for 2 hours under flowing nitrogen while held under tension by tape against an aluminum mask to achieve a water-stable sPPO polymer coating. The resulting coatings were 20% and 90% crosslinked for 0.1 and 0.5 hydroquinone per repeat unit of sPPO, respectively.

[0146] The properties of bilayer membranes crosslinked with hydroquinone and having coatings containing sPPS, sPSU and sPPO prepared according to Examples 6, 15 and 16 were tested. The fuel cell polarization and power curves of the bilayer membrane and uncoated Nafion® 211 are shown in FIG.

[0147] H performed according to Example 8 on a bilayer having a coating containing sPPS, sPSU and sPPO crosslinked with hydroquinone 2 Data obtained in the crossover study are shown in FIG.

[0148] The teachings of all patents, published applications and references cited herein are incorporated by reference in their entirety.

[0149] While the present invention has been particularly shown and described with respect to illustrative embodiments thereof, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the scope of the invention encompassed by the appended claims.

Claims

1. A two-layer polymer electrolyte membrane comprising a first layer and a second layer: The first layer contains perfluorosulfonic acid (PFSA), The second layer comprises a crosslinked polysulfonated polymer containing sulfonated polyphenylsulfone (sPPS), sulfonated polyether ether ketone (sPEEK), sulfonated polyphosphazene (sPOP), sulfonated polybenzimidazole (sPBI), sulfonated polyethersulfone (sPES), sulfonated polyphenylene oxide (sPPO), sulfonated polyarylene ether ketone (sPAEK), sulfonated poly(sulfone) (sPSU), sulfonated poly(sulfide sulfone), sulfonated polyimide (sPI), sulfonated poly(etherimide) (sPEI), sulfonated poly(amine), or a combination thereof. A bilayer polymer electrolyte membrane in which the first layer is positioned on top of the second layer.

2. PFSA has the structural formula (I): 【Chemistry 1】 A polymer containing repeating units represented by, During the ceremony, x is an integer between 1 and 15. m is an integer between 0 and 2, n is an integer from 1 to 5, 【Chemistry 2】 The two-layer polymer electrolyte membrane according to claim 1, wherein represents a point of binding to an adjacent repeating unit.

3. The cross-linked polysulfonated polymer has the following structural formula: 【Transformation 3】 It includes a bridge portion represented by one of the following: During the ceremony, R 1 、R 2 、R 3 and R 4 each independently is selected from H, C 1-12 alkyl, C 1-12 haloalkyl, C 6-14 aryl and C 6-14 aryl(C 1-12 alkylene); R 5 is H or -SO 3 H is, M 2+ However, Mr 2+ Ca 2+ Ba 2+ and Al(X) 2+ Selected from the following, where X is a halide, acetate, or nitrate; k is 1, 2, 3, or 4, 【Chemistry 4】 However, the crosslinked portion represents the point of bonding to the repeating unit of the crosslinked polysulfonated polymer. The two-layer polymer electrolyte membrane according to claim 1.

4. The cross-linked section has the following structural formula: 【Transformation 5】 A two-layer polymer electrolyte membrane according to claim 3, represented by one of the following.

5. The cross-linked polysulfonated polymer contains sPPS or sPSU, and the cross-linked portion has the following structural formula: 【Transformation 6】 A two-layer polymer electrolyte membrane according to claim 3, represented by one of the following.

6. The two-layer polymer electrolyte membrane according to claim 1, wherein the second layer comprises a crosslinked polysulfonated polymer including sulfonated polyphenylsulfone (sPPS), sulfonated polyetheretherketone (sPEEK), sulfonated polyphosphazene (sPOP), sulfonated polybenzimidazole (sPBI), sulfonated polyethersulfone (sPES), sulfonated polyaryleneetherketone (sPAEK), sulfonated poly(sulfone) (sPSU), sulfonated poly(sulfidesulfone), sulfonated polyimide (sPI), sulfonated poly(etherimide) (sPEI), sulfonated poly(amine), or a combination thereof.

7. The two-layer polymer electrolyte membrane according to claim 6, wherein the cross-linked polysulfonated polymer contains sPPS.

8. The two-layer polymer electrolyte membrane according to claim 1, wherein the first layer further comprises a porous matrix containing a matrix polymer, and the PFSA and matrix polymer form an interpenetrating network.

9. The two-layer polymer electrolyte membrane according to claim 8, wherein the matrix polymer is polytetrafluoroethylene (PTFE).

10. The two-layer polymer electrolyte membrane according to claim 1, wherein the degree of sulfonation of the crosslinked polysulfonated polymer is about 100% to about 300%.

11. The two-layer polymer electrolyte membrane according to claim 1, wherein the first layer is continuous.

12. A two-layer polymer electrolyte membrane according to claim 1, wherein the membrane is not supported.

13. The membrane is not supported, The cross-linked polysulfonated polymer is sPPS. The cross-linked section has the following structural formula: 【Transformation 7】 A two-layer polymer electrolyte membrane according to claim 1, represented by one of the following.

14. The membrane is not supported, PFSA structural formula (I): 【Transformation 8】 A polymer containing repeating units represented by, During the ceremony, x is an integer between 5 and 14, m is 1 or 2, n is 2 or 3, The cross-linked polysulfonated polymer contains sPPS or sPSU, and the cross-linked portion has the following structural formula: 【Chemistry 9】 A two-layer polymer electrolyte membrane according to claim 3, represented by one of the following.

15. The membrane is not supported, PFSA structural formula (I): 【Chemistry 10】 A polymer containing repeating units represented by, During the ceremony, x is an integer between 5 and 14, m is 1 or 2, n is 2 or 3, Cross-linked polysulfonated polymers include sPPS and the following structural formula: 【Chemistry 11】 A two-layer polymer electrolyte membrane according to claim 3, comprising a crosslinked portion represented by one of the following.

16. The membrane is not supported, PFSA has the structural formula (I): 【Chemistry 12】 A polymer containing repeating units represented by, During the ceremony, x is an integer between 5 and 14, m is 1 or 2, n is 2 or 3; further The cross-linked polysulfonated polymer is sPPS. The cross-linked section has the following structural formula: 【Chemistry 13】 It is represented by, The degree of sulfonation of sPPS is approximately 200%. The degree of crosslinking of sPPS is approximately 40%. The thickness of the second layer is approximately 0.5 μm to approximately 2 μm. The two-layer polymer electrolyte membrane according to claim 3.

17. The membrane is not supported, PFSA has the structural formula (I): 【Chemistry 14】 A polymer containing repeating units represented by, During the ceremony, x is an integer between 5 and 14, m is 1 or 2, n is 2 or 3; further The cross-linked polysulfonated polymer is sPPS. The cross-linked section has the following structural formula: 【Chemistry 15】 It is represented by one of the following: The degree of sulfonation of sPPS is approximately 200%. The degree of cross-linking of sPPS is approximately 25% to 30%. The thickness of the second layer is approximately 1 μm to 2 μm. The two-layer polymer electrolyte membrane according to claim 3.

18. The first layer comprises a porous matrix containing a matrix polymer, PFSA and matrix polymers form an interpenetrating network. The cross-linked polysulfonated polymer is sPPS. The cross-linked section has the following structural formula: 【Chemistry 16】 It is represented by one of the following: The two-layer polymer electrolyte membrane according to claim 3.

19. a) A step of providing a solution or suspension comprising a first layer having a first surface, a polysulfonated polymer and a crosslinking reagent, b) A step of coating the first surface of the first layer with a solution or suspension to produce a coated first layer; c) Exposing the coated first layer to conditions sufficient for the polysulfonated polymer and crosslinking reagent to undergo a crosslinking reaction, thereby producing a two-layer polymer electrolyte membrane. A method for producing a two-layer polymer electrolyte membrane according to any one of claims 1 to 18, comprising the above.

20. The method according to claim 19, wherein the crosslinking reagent is selected from compounds comprising a polyalcohol, an amine, an epoxide, a thiol, or a terminal alkene or alkyne.

21. The method according to claim 19, wherein the crosslinking reagent is ethylene glycol or glycerol.

22. The method according to claim 19, wherein the crosslinking agent is hydroquinone or 2,5-dihydroxybenzenesulfonic acid.

23. A two-layer polymer electrolyte membrane according to any one of claims 1 to 18; Cathode; and A membrane electrode assembly (MEA) including an anode, A membrane electrode assembly (MEA) in which a two-layer electrolyte membrane is placed between the anode and cathode.

24. A fuel cell comprising one or more MEAs according to claim 23 and one or more gas flow bipolar plates.

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