Proton exchange membrane, and fuel cell and water electrolyser comprising proton exchange membrane

Abstract

The invention relates to a proton exchange membrane and equipment such as a fuel cell comprising the proton exchange membrane. The proton exchange membrane comprises a membrane cathode side layer and a membrane anode side layer, at least one of the membrane cathode side layer and the membrane anode side layer contains a free radical quenching agent, and the content of the free radical quenching agent in the membrane cathode side layer is different from the content of the free radical quenching agent in the membrane anode side layer. And under the condition that the addition amount of the free radical quenching agent is basically not increased, the durability of the proton exchange membrane can be effectively improved by the content of the free radical quenching agent in gradient distribution, and the service life is prolonged.

Description

Technical Field

[0001] The present invention relates to the field of new energy technologies, and particularly to a proton exchange membrane. Background Art

[0002] Fuel cells use hydrogen as a raw material, generate electric energy through the electrochemical reaction of hydrogen and oxygen, and the product is only water; and the reaction process is not restricted by the Carnot cycle, having a higher energy conversion efficiency. Therefore, hydrogen fuel cells have the characteristics of zero pollution and high energy efficiency, and are an important new energy technology.

[0003] The hydrogen production technology by water electrolysis that can be used in combination with wind and photovoltaic power generation is the cleanest and most environmentally friendly hydrogen production technology. Among them, the proton exchange membrane water electrolysis hydrogen production technology is considered the most promising water electrolysis hydrogen production technology due to its advantages of high hydrogen production purity, high hydrogen production efficiency, low energy consumption, stable performance, and the ability to operate at high current densities.

[0004] Both the fuel cells and water electrolyzers used in the above technologies contain a proton exchange membrane (PEM). The service life of the ion exchange membrane directly affects the service life of the fuel cell and the water electrolyzer. In order to improve the service life of the water electrolyzer, a radical quencher can be introduced into the PEM.

[0005] However, when the amount of the radical quencher added is small, it is completely lost in a short time, and the effect of extending the service life of the proton exchange membrane is limited; when the amount of the radical quencher added increases, it will affect the proton conduction performance of the PEM. Therefore, the existing method of adding a radical quencher to improve the service life of the PEM is not ideal enough. Summary of the Invention

[0006] Based on the above problems, the inventors propose the following solution, which can significantly improve the durability of the proton exchange membrane and extend its service life without substantially increasing the amount of the radical quencher added.

[0007] In a first aspect, the present invention provides a proton exchange membrane, characterized in that the proton exchange membrane comprises a membrane cathode side layer and a membrane anode side layer, at least one of the membrane cathode side layer and the membrane anode side layer contains a radical quencher, and the contents of the radical quencher in the membrane cathode side layer and the membrane anode side layer are different.

[0008] Preferably, the content of the radical quencher in the membrane anode side layer is higher than the content of the radical quencher in the membrane cathode side layer; preferably, the mass ratio of the content of the radical quencher in the membrane anode side layer to the content of the radical quencher in the membrane cathode side layer is (100 - 1.0001):(0 - 1), or (100 - 1.0001):(0.0001 - 1).

[0009] Alternatively, preferably, the content of the radical quencher in the cathode-side layer of the membrane is higher than that in the anode-side layer of the membrane; preferably, the mass ratio of the content of the radical quencher in the cathode-side layer of the membrane to that in the anode-side layer of the membrane is (100 - 1.0001):(0 - 1), or (100 - 1.0001):(0.0001 - 1).

[0010] The proton exchange membrane may include a reinforcing layer.

[0011] The thickness of the anode-side layer of the membrane accounts for 1% - 99% of the total thickness of the membrane; the thickness of the cathode-side layer of the membrane accounts for 1% - 99% of the total thickness of the membrane.

[0012] The radical quencher of the present invention is selected from at least one of organic acid compounds, metal compounds, metal organic complexes, and metal organic composites.

[0013] The metal organic complex includes (i) an organic acid compound or its ionic compound, and (ii) a metal ion.

[0014] The metal organic composite includes (i) an organic acid compound or its ionic compound, and (ii) a metal compound.

[0015] Preferably, the metal compound is selected from at least one of metal oxides and metal nanoparticles.

[0016] Preferably, the metal element in the metal ion, metal oxide or metal nanoparticle is selected from at least one of Ce, Mn, Pd, Ag, Au, Pt, Co, Rh, W, or is selected from at least one of Ce and Mn.

[0017] Preferably, the metal compound is selected from cerium oxide, manganese oxide, silver oxide, cobalt oxide, tungsten oxide, gold nanoparticles, silver nanoparticles, platinum nanoparticles, rhodium nanoparticles, nano-cerium oxide, nano-manganese oxide, hydrated nano-cerium oxide or its sol, hydrated nano-manganese oxide or its sol, hydrated nano-tungsten oxide or its sol, hydrated nano-cobalt oxide or its sol, nano-gold sol, nano-silver sol, nano-palladium sol, nano-platinum sol, nano-rhodium sol, etc.

[0018] Preferably, the particle size of the metal nanoparticles is 1 - 500 nm.

[0019] The organic acid compound of the present invention is selected from the following formula I compounds:

[0020]

[0021] Wherein:

[0022] Cy is C containing at least 1 heteroatom 5-15a cyclic compound group, wherein the heteroatom is selected from nitrogen, oxygen or sulfur;

[0023] m is any integer from 1 to 6;

[0024] Each L may be the same or different and is independently selected from a chemical bond or a C 1-10 unsubstituted or R s substituted alkyl group, wherein the R s is selected from halogen, C 1-6 alkyl group, C 1-6 alkyloxy group;

[0025] A is an acid group, and each A may be the same or different and is independently selected from an inorganic acid group or an organic acid group;

[0026] n is any integer from 0 to 12;

[0027] Each R may be the same or different and is independently H, C 1-12 unsubstituted or R s substituted alkyl group.

[0028] In a second aspect of the present invention, there is provided an application of a proton exchange membrane in the preparation of a membrane electrode assembly, a fuel cell, a water electrolyzer, a hydrogen production device, and a flow battery.

[0029] In a third aspect of the present invention, there is provided a fuel cell comprising the proton exchange membrane of the present invention, wherein the content of the radical quencher in the membrane anode side layer of the proton exchange membrane is higher than the content of the radical quencher in the membrane cathode side layer.

[0030] In a fourth aspect of the present invention, there is provided a water electrolyzer comprising the proton exchange membrane of the present invention, wherein the content of the radical quencher in the membrane cathode side layer of the proton exchange membrane is higher than the content of the radical quencher in the membrane anode side layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 : Schematic diagram of the durability experimental test results of the proton exchange membranes in the examples and comparative examples of the present invention.

[0032] Figure 2 : Schematic diagrams of the membrane anode side layer and the membrane cathode side layer of the proton exchange membrane of the present invention. DETAILED DESCRIPTION

[0033] In the following description, numerous specific details are given to provide a more thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the present invention may be practiced without one or more of these details. In other instances, well-known features have not been described in order to avoid obscuring the present invention.

[0034] The implementation of the present invention will be described in detail in combination with the following term definitions:

[0035] I Proton exchange membrane

[0036] In a specific embodiment of the present invention, the proton exchange membrane of the present invention refers to a polymer membrane material having strong acidic groups such as sulfonic acid groups or carboxylic acid groups in the polymer chain and having the property of selectively permeating protons. Examples include perfluorosulfonic acid resin proton exchange membranes.

[0037] The thickness of the proton exchange membrane of the present invention is 4 - 250 μm, 5 - 150 μm, 6 - 100 μm, 8 - 80 μm, or 20 - 60 μm.

[0038] The proton exchange membrane of the present invention comprises at least two membrane layers, one of which is the membrane cathode side layer and the other is the membrane anode side layer. The membrane cathode side layer refers to the membrane layer designed to be closer to the cathode than the membrane anode side layer in the proton exchange membrane. Conversely, the membrane anode side layer refers to the membrane layer designed to be closer to the anode than the membrane cathode side layer in the proton exchange membrane.

[0039] Preferably, the membrane cathode side layer is the surface layer of the proton exchange membrane close to the cathode. Preferably, the membrane anode side layer is the surface layer of the proton exchange membrane close to the anode.

[0040] Preferably, the thickness ratio of the membrane cathode side layer to the membrane anode side layer is 1 - 10:1 - 10, 1 - 5:1 - 5, 1 - 2:1 - 2, or 1:1.

[0041] At least one of the membrane cathode side layer and the membrane anode side layer of the proton exchange membrane of the present invention contains a radical quencher, and the contents of the radical quencher in the membrane cathode side layer and the membrane anode side layer are different.

[0042] Preferably, the distribution of the radical quencher in the membrane cathode side layer and the membrane anode side layer can be uniform, non-uniform, or gradient distribution.

[0043] In one embodiment of the present invention, the content of the radical quencher in the membrane anode side layer is higher than the content of the radical quencher in the membrane cathode side layer.

[0044] Preferably, the mass ratio of the content of the radical quencher in the membrane anode side layer to the content of the radical quencher in the membrane cathode side layer is (100 - 1.0001):(0 - 1), (100 - 1.0001):(0.0001 - 1), (10 - 1.01):(0.01 - 1), (10 - 1.01):(0.1 - 1), (5 - 1.01):(0.5 - 1), or (5 - 1.01):1.

[0045] In another embodiment of the present invention, the content of the radical quencher in the cathode side layer of the membrane is higher than that in the anode side layer of the membrane.

[0046] Preferably, the mass ratio of the content of the radical quencher in the cathode side layer of the membrane to the content of the radical quencher in the anode side layer of the membrane is (100 - 1.0001):(0 - 1), (100 - 1.0001):(0.0001 - 1), (10 - 1.01):(0.01 - 1), (10 - 1.01):(0.1 - 1), (5 - 1.01):(0.5 - 1), or (5 - 1.01):1.

[0047] In one embodiment of the present invention, other layers may also be included in the proton exchange membrane of the present invention to provide the required performance for the proton exchange membrane. Preferably, the other layer is an enhanced layer, such as an expanded polytetrafluoroethylene membrane layer (ePTEF). The addition amount of the reinforcing material may be 5 - 70 wt% of the total mass of the proton exchange membrane.

[0048] In a specific embodiment of the present invention, the radical quencher refers to a substance having the function of quenching radicals. The radical quencher of the present invention is selected from at least one of organic acid compounds, metal compounds, metal organic complexes, and metal organic composites.

[0049] Among them, the metal organic complex contains (i) an organic ligand: an organic acid compound or its ionized product, and (ii) a metal component: a metal ion; the metal organic composite contains (i) an organic ligand: an organic acid compound or its ionized product, and (ii) a metal component: a metal compound.

[0050] Preferably, the metal compound is selected from at least one of metal oxides and metal nanoparticles.

[0051] Preferably, the metal element in the metal ion, metal oxide or metal nanoparticle is selected from at least one of Ce, Mn, Pd, Ag, Au, Pt, Co, Rh, W, or at least one of Ce and Mn.

[0052] Preferably, the metal compound is selected from cerium oxide, manganese oxide, silver oxide, cobalt oxide, tungsten oxide, gold nanoparticles, silver nanoparticles, platinum nanoparticles, rhodium nanoparticles, nano - cerium oxide, nano - manganese oxide, nano - cobalt oxide, nano - tungsten oxide, hydrated nano - cerium oxide or its sol, hydrated nano - manganese oxide or its sol, hydrated nano - tungsten oxide or its sol, hydrated nano - cobalt oxide or its sol, nano - gold sol, nano - silver sol, nano - palladium sol, nano - platinum sol, nano - rhodium sol, etc.

[0053] The molar ratio of the organic ligand to the metal element in the metal organic complex or metal organic composite is 0.1 - 10:1, 0.15 - 8:1, 0.2 - 6:1, 0.25 - 5:1, 0.3 - 4:1, 0.5 - 2:1, or 1:1.

[0054] Preferably, the molar ratio of the organic ligand to the metal element in the metal organic complex or metal organic composite is 0.5 - 2:1, or 1:1.

[0055] In one embodiment of the present invention, in the metal organic complex, the metal component is the metal ion corresponding to Ce, Mn, Pd, Ag, Au, Pt, W, such as monovalent, divalent, trivalent, tetravalent, pentavalent or hexavalent metal ions.

[0056] Preferably, the metal component is the metal ion corresponding to Ce and Mn, such as monovalent, divalent, trivalent, tetravalent metal ions.

[0057] The metal organic complex or metal organic composite of the present invention can be formed by connecting the organic ligand and metal component of the present invention through chemical bonds, ionic bonds, covalent bonds, metallic bonds, coordination bonds, hydrogen bonds or other intra - or intermolecular forces.

[0058] Preferably, the metal organic complex of the present invention is a complex formed by an organic acid compound and its anion and metal cation through ionic bonds and / or coordination bonds.

[0059] In another embodiment of the present invention, the preparation method of the metal organic composite of the present invention comprises the following steps:

[0060] An organic acid compound and a metal oxide or metal nanoparticles are reacted at an acid radical ion: metal element molar ratio of 0.1 - 10:1, 0.2 - 5:1, 0.5 - 2:1, or 1:1 to obtain the product.

[0061] Preferably, the reaction temperature is 20 - 130 °C, 30 - 120 °C, 50 - 110 °C, 70 - 100 °C.

[0062] Preferably, the reaction time is 0.5 - 24 h, 1 - 18 h, 2 - 12 h, 3 - 8 h, or 4 - 6 h.

[0063] In one embodiment of the present invention, the particle size of the metal organic composite of the present invention is 1 - 500 nm, or 5 - 200 nm, or 10 - 100 nm.

[0064] In a specific embodiment of the present invention, since there are usually defect sites on the surface of metal oxides or metal nanoparticles, these defect sites can form unsaturated coordination sites of the metal components of the present invention, enabling the metal components to coordinate with the coordination atoms on the organic ligands of the present invention, such as nitrogen atoms on organic acid compounds or their ionized forms, thereby forming the organometallic complexes of the present invention.

[0065] In one embodiment of the present invention, the organic acid compound of the present invention is selected from the compounds of formula I as follows:

[0066]

[0067] Wherein:

[0068] Cy is a cyclic compound group containing at least 1 heteroatom selected from nitrogen, oxygen or sulfur. 5-15 of C.

[0069] In one embodiment, Cy is a cyclic compound group containing at least 1 heteroatom 5-15 of C, and at least one of the heteroatoms is nitrogen.

[0070] Preferably, Cy is a cyclic compound group containing at least 1 heteroatom 5-14 of C, 5-10 of C, 5-6 of C, 8-9 of C, 9-10 of C, and at least one of the heteroatoms is nitrogen. Wherein, Cy can be a heterocycloalkyl group or a heteroaryl group, or a bicyclic or polycyclic or fused ring group composed of at least one cycloalkyl group and / or at least one aryl group.

[0071] In one embodiment, the cyclic compound group containing at least 1 heteroatom 5-15 of C for Cy is a heteroaryl group 5-10 of C or a nitrogen-containing bicyclic group 5-15 of C.

[0072] When Cy is a heteroaryl group 5-10 of C, Cy contains a heteroaryl group 5-10 containing at least 1 heteroatom 5-6 of C, 8-9 of C, or a heteroaryl group of C, and at least one of the heteroatoms is nitrogen. Preferably, Cy contains at least 2, or 3, or more nitrogen atoms, and may also contain at least 1, 2, or more oxygen atoms and / or sulfur atoms.

[0073] For example, Cy can be selected from the following heteroaryl group 5-10 groups of C:

[0074]

[0075] Preferably, Cy is selected from a pyrrole, thiazole, oxazole, imidazole, pyrazole, pyridine, or pyrimidine group.

[0076] When Cy is a nitrogen-containing bicyclic group of C 5-15 the nitrogen-containing bicyclic group is selected from a C 5-14 or C 5-6 or C 8-9 or C 9-10 nitrogen-containing bicyclic group, with at least one of the heteroatoms being nitrogen. Preferably, Cy contains at least 2, or 3, or more nitrogen atoms, and may also contain at least 1, 2, or more oxygen atoms and / or sulfur atoms.

[0077] For example, Cy may be selected from the following nitrogen-containing bicyclic groups of C 5-15 :

[0078]

[0079] Preferably, Cy is selected from a benzopyrrole group, benzothiazole group, benzoxazole group, benzimidazole group, benzopyrazole group, benzopyridine group, or benzopyrimidine group.

[0080] m is any integer from 1 to 6, and can be 1, 2, 3, 4, 5, or 6. Preferably, m is 1, 2, or 3. Most preferably, m is 1 or 2.

[0081] Each L may be the same or different and is independently a chemical bond or an unsubstituted or R 1-10 substituted alkyl group of C s where R s is selected from halogen, C 1-6 alkyl, C 1-6 alkyloxy.

[0082] Preferably, L is a chemical bond or an alkyl group of C 1-6 When L is an alkyl group of C 1-6 it can be methylene, ethylene, propylene, butylene, pentylene, hexylene. Most preferably, L is an alkyl group of C 1-4 such as methylene, ethylene, propylene, butylene.

[0083] A is an acid group, and each A may be the same or different and is independently selected from an inorganic acid group or an organic acid group, such as a carboxylic acid, phosphoric acid, hypophosphorous acid, phosphorous acid, sulfinic acid, sulfonic acid, or boric acid group. Preferably, A is selected from -SO3H, -COOH, -PO3H2.

[0084] n is any integer from 0 to 12, and can be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12. Preferably, n is 0, 1, 2, 3, 4, 5, or 6.

[0085] Each R can be the same or different and is independently H, C 1-12 or C 1-6 unsubstituted or substituted by R s of the alkyl group, and the definition of R s is as described above. When R is an alkyl group, it can be methyl, ethyl, propyl, butyl, pentyl, or hexyl.

[0086] In another embodiment of the present invention, the compound of formula I is selected from the following compounds of formula II:

[0087]

[0088] wherein, X1 to X9 can be the same or different and are independently selected from C, N, O, S, and at least one of X1 to X9 is a nitrogen atom. Preferably, at least two or more of X1 to X9 are nitrogen atoms, and more preferably, two of X1 to X9 are nitrogen atoms.

[0089] As an example, the group in formula II contains a group derived from the following heteroaromatic ring:

[0090]

[0091] The definition of m is as described above.

[0092] -L1-SO3H can be substituted on any of the atoms of X1 to X9. Each L1 can be the same or different and is independently a chemical bond or C 1-4 of the alkyl group. Preferably, L1 is a chemical bond or methylene.

[0093] n is any integer from 0 to 6, and can be 0, 1, 2, 3, 4, 5, or 6.

[0094] R1 can be substituted on any of the atoms of X1 to X9. Each R1 can be the same or different and is independently H, C 1-4 of the alkyl group, preferably H, methyl, or ethyl.

[0095] In another embodiment of the present invention, the compound of formula I is selected from the following compounds of formula III:

[0096]

[0097] wherein, -L2-A can be substituted at any position on the benzimidazole ring. Each L2 can be the same or different and is independently a chemical bond or C 1-4alkyl groups. Preferably, L2 is a chemical bond or a methylene group. Most preferably, L2 is a chemical bond.

[0098] A, n, and m are defined as in any of the previous embodiments.

[0099] R2 can be substituted at any position on the benzimidazole ring. Each R2 can be the same or different and is independently H, C 1-4 substituted or unsubstituted alkyl groups, preferably H, methyl, or ethyl.

[0100] In a specific embodiment of the present invention, the compound of formula I is:

[0101]

[0102] II Application

[0103] The proton exchange membrane of the present invention is particularly suitable for preparing membrane electrode assemblies, fuel cells, water electrolyzers, hydrogen production equipment, and flow batteries.

[0104] Preferably, the proton exchange membrane of the present invention is particularly suitable for preparing fuel cells or water electrolyzers.

[0105] In one example, the fuel cell comprises the proton exchange membrane of the present invention, and the content of the radical quencher in the anode side layer of the membrane is higher than the content of the radical quencher in the cathode side layer of the membrane.

[0106] Preferably, the mass ratio of the content of the radical quencher in the anode side layer of the membrane to the content of the radical quencher in the cathode side layer of the membrane is (100 - 1.0001):(0 - 1), (100 - 1.0001):(0.0001 - 1), (10 - 1.01):(0.01 - 1), (10 - 1.01):(0.1 - 1), (5 - 1.01):(0.5 - 1), or (5 - 1.01):1.

[0107] Preferably, the thickness ratio of the anode side layer of the membrane to the cathode side layer of the membrane is: 1 - 10:1, 1 - 5:1, 1 - 2:1, or 1:1.

[0108] In another example, the water electrolyzer comprises the proton exchange membrane of the present invention, and the content of the radical quencher in the cathode side layer of the membrane is higher than the content of the radical quencher in the anode side layer of the membrane.

[0109] Preferably, the mass ratio of the content of the radical quencher in the membrane cathode side layer to the content of the radical quencher in the membrane anode side layer is (100 - 1.0001):(0 - 1), (100 - 1.0001):(0.0001 - 1), (10 - 1.01):(0.01 - 1), (10 - 1.01):(0.1 - 1), (5 - 1.01):(0.5 - 1), or (5 - 1.01):1.

[0110] Preferably, the thickness ratio of the membrane cathode side layer to the membrane anode side layer is: 1 - 10:1, 1 - 5:1, 1 - 2:1, or 1:1.

[0111] The present invention will be described in detail below in conjunction with specific embodiments.

[0112] Example 1

[0113] Take the Nafion D2020CS resin dispersion (solid content 20%), add 5 wt.% of the hydrated nano-ceria aqueous solution to it, and the mass ratio of the resin to ceria is 100:0.5. After mixing evenly, a coating solution is prepared.

[0114] Use the above coating solution to prepare 12 μm and 50 μm PEMs respectively by the double-slit extrusion coating process, and name them NC05-12 and NC05-50 respectively.

[0115] Example 2

[0116] Take the Nafion D2020CS resin dispersion (solid content 20%), add 5 wt.% of the hydrated nano-ceria to it, so that the mass ratio of the resin to ceria in the coating solution is 100:0.7. After mixing evenly, a coating solution a is prepared.

[0117] Take the Nafion D2020CS resin dispersion (solid content 20%), add 5 wt.% of the hydrated nano-ceria to it, so that the mass ratio of the resin to ceria in the coating solution is 100:0.3. After mixing evenly, a coating solution b is prepared.

[0118] Use coating solution a as the anode coating solution and coating solution b as the cathode coating solution, and prepare a 12 μm PEM by the double-slit extrusion coating process. The amounts of coating solution a and coating solution b used in the coating operation are the same. This PEM is named NCe0703-12.

[0119] Use coating solution a as the cathode coating solution and coating solution b as the anode coating solution, and prepare a 50 μm PEM by the double-slit extrusion coating process. The amounts of coating solution a and coating solution b used in the coating operation are the same. This PEM is named NCe0307-50.

[0120] Example 3

[0121] Take 100 g of hydrated nano-manganese oxide sol with a solid content (calculated as MnO₂) of 5.0%, and add 2-methylbenzimidazole-5-sulfonic acid thereto so that the molar ratio of 2-methylbenzimidazole-5-sulfonic acid to MnO₂ is 1:3, and mix well. Transfer the above solution to a sealed reaction kettle, raise the temperature to 80 °C, and react for 4 h to obtain a colloid of 2-methylbenzimidazole-5-sulfonic acid and hydrated nano-ceria composite, denoted as MnO-MBIS.

[0122] Example 4

[0123] Take Nafion D2020CS resin dispersion (solid content 20%), add MnO-MBIS sol thereto so that the mass ratio of the resin to MnO₂ is 1000:5, and mix well to prepare a coating solution.

[0124] Use the above coating solution to prepare 12 μm and 50 μm PEMs by a double-slit extrusion coating process, named NMMBIS05-12 and NMMBIS05-50 respectively.

[0125] Example 5

[0126] Take Nafion D2020CS resin dispersion (solid content 20%), add the MnO-MBIS sol prepared in Example 3 thereto so that the ratio of the resin to MnO₂ is 1000:7, and mix well to prepare coating solution c.

[0127] Take Nafion D2020CS resin dispersion (solid content 20%), add the MnO-MBIS sol prepared in Example 3 thereto so that the ratio of the resin to MnO₂ is 1000:3, and mix well to prepare coating solution d.

[0128] Use coating solution c as the anode coating solution and coating solution d as the cathode coating solution to prepare a 12 μm PEM by a double-slit extrusion coating process, where the amounts and thicknesses of coating solution c and coating solution d are the same during the coating operation, and this PEM is named NMMBIS0703-12.

[0129] Use coating solution c as the cathode coating solution and coating solution d as the anode coating solution to prepare a 50 μm PEM by a double-slit extrusion coating process, where the amounts and thicknesses of coating solution c and coating solution d are the same during the coating operation, and this PEM is named NMMBIS0307-50.

[0130] Example 6

[0131] Take 100 g of hydrated nano-ceria sol with a solid content (calculated as CeO2) of 5.0%, and add benzimidazole-5,6-dicarboxylic acid thereto so that the molar ratio of benzimidazole-5,6-dicarboxylic acid to CeO2 is 1:3, and mix well. Transfer the above solution to a sealed reaction kettle, raise the temperature to 80 °C, and react for 4 h to obtain a colloid of a benzimidazole-5,6-dicarboxylic acid and hydrated nano-ceria complex, denoted as CeO-BIDCA.

[0132] Example 7

[0133] Take Nafion D2020CS resin dispersion (solid content 20%), add CeO-BIDCA sol thereto so that the mass ratio of the resin to CeO2 is 100:1, and mix well to prepare a coating solution.

[0134] Use the above coating solution to prepare 12 μm and 50 μm PEMs by a double-slit extrusion coating process, and name them NCBIDCA10-12 and NCBIDCA10-50 respectively.

[0135] Example 8

[0136] Take Nafion D2020CS resin dispersion (solid content 20%), add the CeO-BIDCA sol prepared in Example 6 thereto so that the ratio of the resin to CeO2 is 100:1.5, and mix well to prepare coating solution e.

[0137] Take Nafion D2020CS resin dispersion (solid content 20%), add the CeO-BIDCA sol prepared in Example 6 thereto so that the ratio of the resin to CeO2 is 100:0.5, and mix well to prepare coating solution f.

[0138] Use coating solution e as the anode coating solution and coating solution f as the cathode coating solution to prepare a 12 μm PEM by a double-slit extrusion coating process. The amounts of coating solution e and coating solution f used in the coating operation are the same and the thicknesses are the same. This PEM is named NCBIDCA1505-12.

[0139] Use coating solution e as the cathode coating solution and coating solution f as the anode coating solution to prepare a 50 μm PEM by a double-slit extrusion coating process. The amounts of coating solution e and coating solution f used in the coating operation are the same and the thicknesses are the same. This PEM is named NCBIDCA0515-50.

[0140] Example 9

[0141] Cut the PEMs prepared in Examples 1-2 and Examples 4-5 and test the proton conductivity at 85 °C and RH 50% according to the method of GB / T 200242.3-2022. The measured results are shown in Table 1.

[0142] Example 10

[0143] The 12-μm PEMs prepared in Examples 1-2, Examples 4, 5, Examples 7, and 8 were made into membrane electrodes, assembled into single cells, and subjected to chemical durability tests. The test conditions are shown in Table 2. During the test, the open-circuit voltage and hydrogen permeation current density of the cell were monitored. When the open-circuit voltage drop reached 20% and / or the hydrogen permeation current density > 15 mA / cm 2 was used as the failure criterion. The open-circuit voltage was monitored in real time, and the hydrogen permeation current density was measured every about 100 h. The test results are as Figure 1 shown.

[0144] The 50-μm PEMs prepared in Examples 1-2, 4-5, 7-8 were made into membrane electrodes, assembled into electrolyzers, and subjected to chemical durability tests. The test conditions are shown in Table 3. During the test, the electrolyzer voltage was monitored. After 3000 h, the voltage increase rate was calculated by the difference in voltage between the end and the beginning of the experiment. The calculation formula is as follows:

[0145] Voltage increase rate (μV / h) = (end voltage - initial voltage) / experimental duration (3000 h).

[0146] The test results are shown in Table 4.

[0147] Table 1 Fluoride ion dissolution amount in Fenton experiments of each membrane material

[0148]

[0149] Table 2 Chemical durability test conditions of single cells

[0150]

[0151]

[0152] Table 3 Chemical durability test conditions of electrolyzers

[0153] Item Parameter <![CDATA[Effective area cm 2 > 25 Operating Temperature °C 60 Current Density <![CDATA[2A / cm 2 > Pressure 1 bar

[0154] Table 4 Voltage increase rate in electrolyzer durability experiments of each membrane material

[0155] Example Membrane Material Voltage Increase Rate Example 1 NC05-50 3.5 μV / h Example 2 NC0307-50 2.8 μV / h Example 4 NMMBIS05-50 3.2 μV / h Example 5 NMMBIS0307-50 2.5 μV / h Example 7 NCBIDCA10-50 3.0 μV / h Example 8 NCBIDCA0515-50 2.1 μV / h

[0156] It can be seen from the examples and comparative examples of the present invention that:

[0157] (1) Under the condition that the total amount of radical scavengers is the same, different contents of radical scavengers on the cathode and anode sides will not cause differences in the proton conduction performance of the PEM.

[0158] (2) When the contents of radical scavengers on the cathode and anode sides are different, the chemical durability of the proton exchange membrane of the present invention is significantly improved.

[0159] In the above embodiments, all technical solutions falling within the concept of the present invention are within the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A proton exchange membrane, characterized in that, The proton exchange membrane comprises a membrane cathode side layer and a membrane anode side layer, at least one of the membrane cathode side layer and the membrane anode side layer contains a radical quencher, and the contents of the radical quencher in the membrane cathode side layer and the membrane anode side layer are different.

2. The proton exchange membrane according to claim 1, characterized in that: The content of the radical quencher in the membrane anode side layer is higher than the content of the radical quencher in the membrane cathode side layer; preferably, the mass ratio of the content of the radical quencher in the membrane anode side layer to the content of the radical quencher in the membrane cathode side layer is (100 - 1.0001):(0 - 1), or (100 - 1.0001):(0.0001 - 1); Or, the content of the radical quencher in the membrane cathode side layer is higher than the content of the radical quencher in the membrane anode side layer; preferably, the mass ratio of the content of the radical quencher in the membrane cathode side layer to the content of the radical quencher in the membrane anode side layer is (100 - 1.0001):(0 - 1), or (100 - 1.0001):(0.0001 - 1).

3. The proton exchange membrane according to claim 1, wherein the proton exchange membrane comprises a reinforcing layer.

4. The proton exchange membrane according to any one of claims 1 - 3, wherein the radical quencher is selected from at least one of organic acid compounds, metal compounds, metal organic complexes, and metal organic composites; The metal organic complex comprises (i) an organic acid compound or its ionic compound, and (ii) a metal ion; The metal organic composite comprises (i) an organic acid compound or its ionic compound, and (ii) a metal compound; Preferably, the metal compound is selected from at least one of metal oxides and metal nanoparticles; Preferably, the metal element in the metal ion, metal oxide or metal nanoparticle is selected from at least one of Ce, Mn, Pd, Ag, Au, Pt, Co, Rh, W, or selected from at least one of Ce and Mn; Preferably, the metal compound is selected from cerium oxide, manganese oxide, silver oxide, cobalt oxide, tungsten oxide, gold nanoparticles, silver nanoparticles, platinum nanoparticles, rhodium nanoparticles, nano-cerium oxide, nano-manganese oxide, hydrated nano-cerium oxide or its sol, hydrated nano-manganese oxide or its sol, hydrated nano-tungsten oxide or its sol, hydrated nano-cobalt oxide or its sol, nano-gold sol, nano-silver sol, nano-palladium sol, nano-platinum sol, nano-rhodium sol, etc.; Preferably, the particle size of the metal nanoparticles is 1 - 500 nm.

5. The proton exchange membrane according to claim 4, wherein the organic acid compound is selected from the following formula I compounds: Wherein: Cy is a cyclic compound group of C containing at least 1 heteroatom, and the heteroatom is selected from nitrogen, oxygen or sulfur; 5-15 ​ m is any integer from 1 to 6; Each L can be the same or different and is independently selected from a chemical bond or an unsubstituted or R 1-10 -substituted alkyl group, where the R s is selected from halogen, C s alkyl group, C 1-6 alkyloxy group; 1-6 ​ A is an acid group, and each A can be the same or different and is independently selected from an inorganic acid group or an organic acid group; n is any integer from 0 to 12; Each R may be the same or different and each independently is H, C 1-12 which is unsubstituted or substituted by R s substituted alkyl group.

6. Use of the proton exchange membrane according to any one of claims 1 - 5 in the preparation of a membrane electrode assembly, a fuel cell, a water electrolyzer, a hydrogen production device, and a flow battery.

7. A fuel cell comprising the proton exchange membrane according to any one of claims 1-5, wherein the content of the radical quencher in the anode-side layer of the membrane is higher than that in the cathode-side layer of the membrane.

8. An electrolytic water cell comprising the proton exchange membrane according to any one of claims 1-5, wherein the content of the radical quencher in the cathode-side layer of the membrane is higher than that in the anode-side layer of the membrane.

Images