High-performance proton exchange membrane and roll-to-roll batch preparation method thereof

Abstract

The invention relates to the technical field of fuel cells, in particular to a high-performance proton exchange membrane and a roll-to-roll batch preparation method thereof. The proton exchange membrane comprises a perfluorosulfonic acid-based membrane, one surface of the perfluorosulfonic acid-based membrane is provided with a COFS layer, and the other surface of the perfluorosulfonic acid-based membrane is provided with an IL-Si dynamic crosslinking layer; the COFS layer is formed by performing thermal field induced crystallization on a sulfonated COFS solution, and the IL-Si dynamic cross-linking layer is formed by coating an ionic liquid-containing functionalized siloxane dynamic cross-linking agent solution; a COFS layer is arranged on one side of a perfluorosulfonic acid-based membrane, an IL-Si dynamic crosslinking layer is arranged on the other side of the perfluorosulfonic acid-based membrane, and two independent and symmetrical proton-self-repairing dual-network synergistic structures are formed on the two sides of the perfluorosulfonic acid-based membrane through the two structures.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and more particularly to a high-performance proton exchange membrane and a roll-to-roll batch preparation method thereof. Background Technology

[0002] Proton exchange membranes (PEMs), as core components of proton exchange membrane fuel cells (PEMFCs) and water electrolysis for hydrogen production (PEMWEs), must meet requirements such as high proton conductivity, excellent chemical stability, high mechanical strength, and long lifespan. Traditional single-layer perfluorosulfonic acid-based membranes generally cannot meet these multi-performance requirements. For example, they suffer from mechanical durability issues; frequent wet-dry cycles cause repeated expansion and contraction of the membrane, inducing mechanical stress, which can easily lead to cracks or perforations after long-term use, shortening battery life. Therefore, extensive research on proton exchange membranes has emerged.

[0003] In mass production, roll-to-roll coating has become a commonly used process for the mass production of proton exchange membranes due to its high efficiency and continuous production advantages. This technology can achieve high-speed continuous coating, thereby greatly improving production efficiency. However, during the coating process, delamination can easily occur between different material layers due to insufficient interfacial bonding. Such interfacial defects can seriously affect the overall performance and reliability of the membrane electrode assembly.

[0004] In summary, how to prepare a proton exchange membrane with high mechanical durability using a roll-to-roll coating process, and how to improve the delamination phenomenon during the coating process, is one of the urgent problems to be solved in the field of fuel cell proton exchange membrane preparation. Summary of the Invention

[0005] The purpose of this invention is to provide a high-performance proton exchange membrane and a roll-to-roll batch preparation method thereof. Its advantages are that it has high interlayer bonding strength and self-healing ability, thus exhibiting good mechanical durability and being suitable for large-scale roll-to-roll coating processes.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: The first aspect of this invention provides a method for preparing a proton exchange membrane, comprising the following steps: Step 1: The perfluorosulfonic acid-based membrane is plasma activated on both sides, and then grafted by immersion in a silane coupling agent solution. Step 2: Coat the first side of the perfluorosulfonic acid-based film obtained in Step 1 with sulfonated COF. S The solution, induced by an infrared thermal field, crystallizes to form COF. S layer; Step 3: After coating the second surface with an ionic liquid-functionalized siloxane dynamic crosslinking agent solution, pre-dry the coating layer and then irradiate it with ultraviolet light. Subsequently, dynamic crosslinking is performed using a three-level gradient temperature control and infrared thermal field coupling. The ionic liquid-functionalized siloxane dynamic crosslinking agent solution contains siloxane prepolymer, ionic liquid, photoinitiator and ethanol solvent. Step 4: Perform gradient annealing on the membrane material obtained in Step 3 to obtain the proton exchange membrane.

[0007] The present invention is further configured such that, in step 1, the conditions for plasma activation are: the working gas is a mixture of Ar and O2 with a volume ratio of 1:1, the gas flow rate is 50-200 mL / min, the plasma excitation treatment time is 30-120 s / face, and the power is 60-120 W. The method for grafting silane coupling agent is as follows: the plasma-activated perfluorosulfonic acid-based membrane is immersed in a silane coupling agent solution for grafting, and then dried; wherein the immersion temperature is 25-40℃ and the time is 10-15min; the drying temperature is 60-80℃ and the time is 10-20min. The silane coupling agent solution is a 3-aminopropyltriethoxysilane (KH-550) solution with a mass concentration of 2-5 wt%. KH-550 is mixed with a mixed solvent, stirred, and the pH is adjusted to 4-5 to obtain the KH-550 solution. The mixed solvent is ethanol and water with a volume ratio of 9:1.

[0008] The present invention is further configured such that, in step 2, the infrared thermal field-induced crystallization uses an infrared radiation heater with an infrared wavelength of 2-5 μm and a power density of 1-3 W / cm². 2 The temperature for thermal field-induced crystallization is 100-120℃, and the time is 10-20 min. The sulfonated COF S The solution preparation steps are as follows: In the sulfonated COF... S Sodium dodecylbenzenesulfonate was added to a mixture of sodium dodecylbenzenesulfonate and DMSO to achieve a concentration of 0.2 wt%. The mixture was then sonicated at 40 kHz and 800 W for 45-60 min to obtain sulfonated COF. S Solution, in which sulfonated COF S Sulfonated COF in a mixture of DMSO S The mass concentration is 5-15 wt%, sulfonated COF SIt is one of TpPa-SO3H and TpBD-(SO3H)2, wherein the pore size of TpPa-SO3H is 1.2-1.8 nm and the sulfonic acid group density is 3-4 mmol / g, and the pore size of TpBD-(SO3H)2 is 1.8-2.4 nm and the sulfonic acid group density is 2.8-3.6 mmol / g.

[0009] The present invention is further configured such that, in step 3, the pre-drying temperature is 60-80℃ and the time is 2-5 min; The mass ratio of siloxane prepolymer, ionic liquid, and photoinitiator is (1-3):(2-5):(0.1-1), and the solid content is 20-40 wt%. The siloxane prepolymer is methacryloyloxypropyltrimethoxysilane, the ionic liquid is [BMIM][TFSI], and the photoinitiator is one of Irgacure 1173 and Irgacure 184.

[0010] The present invention is further configured such that, in step 4, the ultraviolet light irradiation time is 30-120 seconds; The coupling parameters of the three-level gradient temperature control and infrared thermal field are as follows: Level 1 temperature zone: 80-110℃, irradiation time: 30-90s; Level 2 temperature zone: 130-150℃, irradiation time: 60-120s; Level 3 temperature zone: 170-190℃, irradiation time: 30-60s.

[0011] The present invention is further configured such that, in step 5, the gradient annealing conditions are as follows: the first stage annealing temperature is 120-130℃, the time is 2-4h, and the heating rate is ≤1℃ / min; the second stage annealing temperature is 160-170℃, the time is 4-8h, and the heating rate is ≤0.5℃ / min.

[0012] A second aspect of the present invention provides a proton exchange membrane prepared by the above-described preparation method, characterized in that: it comprises a perfluorosulfonic acid-based membrane, wherein one side of the perfluorosulfonic acid-based membrane is provided with COF. S The other side of the perfluorosulfonic acid-based membrane is provided with an IL-Si dynamic crosslinking layer; The thickness of the perfluorosulfonic acid-based film is 5-20 μm, and the COF... S The thickness of the layer is 0.5-2 μm, and the thickness of the IL-Si dynamic crosslinking layer is 1-3 μm.

[0013] The third aspect of this invention provides a roll-to-roll production line for preparing the above-mentioned proton exchange membrane. The production line has a conveying mechanism, which includes a base film unwinding roller, a base film take-up roller, and a conveying roller located between the base film unwinding roller and the base film take-up roller. Along the conveying direction of the conveying mechanism, the roller is sequentially configured as a plasma activation zone, a grafting impregnation tank, a first drying unit, a first coating zone, a hot field drying unit, a turning roller assembly, a second coating zone, a pre-drying unit, a UV irradiation heating zone, and an infrared hot field heating zone. The plasma activation zone includes a plasma processing chamber, a vacuum pump for evacuating the plasma processing chamber, and a gas source pipe for injecting gas into the plasma processing chamber. The plasma processing chamber is provided with a pair of electrode plates parallel to the base film being conveyed, and respectively positioned above and below the base film being conveyed. The infrared thermal field heating zone includes a temperature-controlled oven with an integrated infrared radiator. The temperature-controlled oven contains a primary temperature zone, a secondary temperature zone, and a tertiary temperature zone, arranged sequentially along the conveying direction of the conveying mechanism.

[0014] A fourth aspect of the present invention provides a method for preparing a proton exchange membrane using the above-described production line, comprising the following steps: S1. Place the perfluorosulfonic acid-based film in the production line and convey it under tension by a conveying mechanism with a linear speed of 1-1.8 m / min. S2. The perfluorosulfonic acid-based membrane is transferred to the plasma processing chamber for plasma activation treatment of both the upper and lower surfaces of the perfluorosulfonic acid-based membrane. The plasma activation time is 30-120s / side. S3. Pour the silane coupling agent solution into the grafting impregnation tank and control the temperature at 25-40℃. The perfluorosulfonic acid base film is impregnated in the grafting impregnation tank under the conveying mechanism and continuously conveyed for 10-15 minutes to achieve the grafting reaction. Then, it is dried in the first drying unit at 60-80℃ under vacuum for 10-20 minutes to complete the silane coupling agent grafting reaction. S4, Preparation of sulfonated COF S The solution is placed in the feeding system of the first coating area. The perfluorosulfonic acid-based film, which completes S3, arrives at the first coating area under the conveying mechanism. Sulfonated COF is then coated on the first surface of the perfluorosulfonic acid-based film. S The solution was coated at a speed of 0.5-0.8 m / min, followed by thermal field-induced crystallization treatment at 100-120℃ for 10-20 min in a thermal field drying unit, which forms COF on the first surface of the perfluorosulfonic acid-based film. S layer; S5. Prepare a solution of ionic liquid functionalized siloxane dynamic crosslinking agent and place it in the feeding system of the second coating zone. The perfluorosulfonic acid-based film completed in S4 is rotated 180° under the action of the steering roller assembly. Then, it is conveyed to the second coating zone by the conveying mechanism. In the second coating zone, the solution of ionic liquid functionalized siloxane dynamic crosslinking agent is sprayed on the second side at a spraying rate of 50-400 mL / min. Then, it is pre-dried at 60-80℃ for 2-5 min in the pre-drying unit. S6. Irradiate the second coating layer with ultraviolet light sequentially. The ultraviolet light wavelength is 365nm and the intensity is 200-400MW / cm. 2 The irradiation time is 30-120s. The second coating layer is irradiated using a three-step temperature-controlled coupled infrared thermal field within the infrared thermal field region. Along the film material's transport direction, the irradiation sequence is as follows: First-level temperature zone 80-110℃, irradiation time 30-90s, infrared wavelength 3.0-4.0μm, infrared power density 2-4W / cm². 2 Secondary temperature range: 130-150℃; irradiation time: 60-120s; infrared wavelength: 1.2-1.8μm; infrared power density: 5-8W / cm². 2 The temperature range is 170-190℃ (Level 3), the irradiation time is 30-60s, the infrared wavelength is 0.8-1.2μm, and the infrared power density is 8-12W / cm². 2 ; S7. After the membrane material from S6 is wound up at the take-up roller, it is manually fed into a hot air circulating oven with continuous nitrogen blowing. The temperature is raised to 120-130℃ at a heating rate of ≤1℃ / min and treated for 2-4 hours. Then, the temperature is raised to 160-170℃ at a heating rate of ≤0.5℃ / min and treated for 4-8 hours. Finally, it is naturally cooled to room temperature to obtain the proton exchange membrane.

[0015] The present invention is further configured such that, in step S2, the specific steps of plasma activation are as follows: A. The perfluorosulfonic acid-based film is fixed on the conveyor mechanism of the production line and conveyed to the plasma activation zone; B. Start the vacuum pump in the plasma activation zone to reduce the pressure in the plasma processing chamber to below 50 Pa; C. Introduce a 1:1 mixture of Ar and O2 gas into the plasma processing chamber through a gas source pipe at a flow rate of 50-200 mL / min. D. Start the radio frequency power supply of the electrode plate to achieve plasma excitation treatment on both sides of the perfluorosulfonic acid-based film. The treatment time is 30-180s and the power is 60-120W.

[0016] In summary, the present invention has the following beneficial effects: 1. The method of the present invention achieves the formation of COF on one side of a perfluorosulfonic acid-based membrane.S On one side, an IL-Si dynamic cross-linking layer is applied. These two structures form two independent and symmetrical proton-self-healing dual-network synergistic structures on both sides of the perfluorosulfonic acid-based membrane, achieving a functional partitioning design. In this case, the COFs layer focuses on proton conduction, while the IL-Si dynamic cross-linking layer is responsible for self-healing, avoiding performance conflicts. Furthermore, the two coatings are prepared separately, and the COFs... S The layer can provide mechanical support for the preparation of the IL-Si dynamic cross-linked layer on the reverse side, and the functional layers on both sides can be indirectly coupled through the ion cluster network of the perfluorosulfonic acid base membrane to maintain the overall proton conduction stability. Therefore, the two coatings complement each other on both sides of the base membrane without causing functional conflict, making the base proton exchange membrane have better performance and lifespan.

[0017] 2. COF in this invention S The ordered pore structure of the coating provides directional channels for proton transport, reducing mass transfer resistance and making the inert ion exchange membrane perform better, especially under high humidity or high temperature conditions. The ionic liquid of IL-Si, as a proton carrier, enhances the proton conductivity through a "jump-diffusion" mechanism. At the same time, the high temperature resistance of the ionic liquid of L-Si alleviates the problem of decreased proton conductivity caused by high-temperature water loss of the perfluorosulfonic acid membrane. Therefore, the integration of the two coatings on the perfluorosulfonic acid-based membrane also makes the inert ion exchange membrane have a high proton conductivity, effectively improving the performance of the fuel cell.

[0018] 3. The plasma treatment of both sides of the perfluorosulfonic acid-based film in this invention: By activating the double-sided surface with low-temperature plasma and then introducing hydroxyl or carboxyl functional groups, the COF can be effectively improved. S The adhesion of IL-Si to the perfluorosulfonic acid-based film reduces the risk of interfacial delamination. Then, a chemical grafting process is used: silane coupling agents are grafted onto both sides of the perfluorosulfonic acid-based film. The ethoxy groups in the silane molecules hydrolyze to generate silanols, which condense with the hydroxyl groups on the film surface to form covalent bonds. Simultaneously, the amino groups at the other end react with COF... S The precursors are bonded through hydrogen bonds or imine bonds, which further enhances the interlayer adhesion between the two coatings and the perfluorosulfonic acid-based film.

[0019] 4. This invention employs gradient annealing, which promotes COF through staged heating. S Further orderly arrangement of the organic framework in the layer reduces grain boundary defects and enhances pore connectivity. First, the crystalline regions of the perfluorosulfonic acid film partially melt and rearrange at 120°C, and after annealing at 160°C, a more uniform ion cluster distribution is formed, optimizing proton transport channels. Second, high-temperature annealing promotes the reversible recombination of siloxane dynamic bonds in the IL-Si layer, increasing crosslinking density. In addition, rapid UV / IR crosslinking may lead to local stress concentration, and gradient annealing reduces the risk of microcrack initiation by slowly releasing thermal stress.

[0020] 5. This invention addresses the shortcomings of perfluorosulfonic acid-based membranes, which suffer from poor flexibility and easy deformation, by employing a roll-to-roll process for the mass production of proton exchange membranes. Firstly, this invention selects a thin perfluorosulfonic acid membrane and enhances its flexibility through chemical grafting to adapt to the mechanical tension of the R2R production line. Simultaneously, a COF coating is formed on one side of the perfluorosulfonic acid-based membrane. S Layer, COF S The rigid frame provides structural support, effectively resisting swelling and deformation during roll-to-roll transport. Then, an IL-Si dynamic cross-linked layer is coated on the other side of the perfluorosulfonic acid-based film. The dynamic chemical bonds in IL-Si can spontaneously recombine after mechanical damage, repairing microscopic defects and extending the film's lifespan. This coating can automatically optimize cracks caused by mechanical tension / roll transport factors in roll-to-roll processes. Additionally, COF... S The rigid framework inhibits water absorption and swelling, while the dynamic cross-linking of IL-Si alleviates thermal stress, thus the intrinsic ion exchange membrane exhibits better membrane size stability; and COF S The rigid skeleton of the layer and the dynamic network of the IL-Si layer respectively suppress water absorption and swelling on both sides of the base film, reducing interlayer shear stress caused by expansion differences. Therefore, the design of the above two coatings can make the perfluorosulfonic acid base film more adaptable to roll-to-roll processes.

[0021] 6. This invention employs a combined ultraviolet and infrared crosslinking approach for the IL-Si dynamic crosslinking layer. UV light rapidly fixes the main structure of the IL-Si prepolymer, while the infrared thermal field dynamically regulates siloxane bond recombination in subsequent processes, achieving a phased reaction of "rapid curing + dynamic optimization." Therefore, this method can adapt to and match the production line speed of roll-to-roll processes, effectively overcoming the process bottleneck of continuous dynamic crosslinking. In addition, the infrared thermal field-assisted dynamic crosslinking reaction can adapt to temperature fluctuations, ensuring the film maintains a stable network structure under different operating conditions. Furthermore, a three-level gradient temperature control coupled with an infrared thermal field is used for dynamic crosslinking: the first temperature zone (80-110℃) implements solvent evaporation and infrared preheating; the second temperature zone (130-150℃) implements the siloxane condensation reaction; and the third temperature zone (170-190℃) implements dynamic disulfide bond network reconstruction. This graded temperature control mode can better ensure the stability of the crosslinking process and the robustness of the crosslinked structure. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the production line structure in Example 4; In the diagram: 1. Base film unwinding roller; 2. Plasma activation zone; 2-1. Plasma treatment chamber; 2-2. Vacuum pump; 2-3. Gas source pipeline; 2-4. Electrode plate; 3. Grafting impregnation tank; 4. First drying unit; 5. First coating zone; 6. Hot field drying unit; 7. Directing roller assembly; 8. Second coating zone; 9. Pre-drying unit; 10. UV irradiation heating zone; 11. Infrared hot field heating zone; 11-1. Primary temperature zone; 11-2. Secondary temperature zone; 11-3. Tertiary temperature zone; 12. Base film take-up roller; Figure 2 This is a photograph of the severely peeled coating in Comparative Example 4. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings.

[0024] Example 1 Step a, Pretreatment of perfluorosulfonic acid base film: The perfluorosulfonic acid base film with a thickness of 20 μm was subjected to plasma activation treatment. The plasma activation treatment conditions were: Ar and O2 mixed gas with a working gas volume ratio of 1:1, gas flow rate of 200 mL / min, plasma excitation treatment for 120 s / face, power of 120 W, 5 g KH-550 was dissolved in 225 ml ethanol and 25 ml water in an ethanol / water mixed solution, the pH was adjusted to 5 to obtain a mixed solution, and then the base film after plasma activation treatment was placed in the mixed solution, soaked at 40℃ for 15 min, and dried at 80℃ for 20 min to complete the grafting. Step b, COF S Layer preparation: 15g of TpPa-SO3H with a sulfonic acid group density of 4mmol / g and a pore size of 1.2nm was dissolved in 84.8g of DMSO, and then 0.2g of sodium dodecylbenzenesulfonate was added. The mixture was ultrasonically treated at 800W and 40kHz for 60min to obtain sulfonated COF. S Solution, sulfonated COF S The solution was coated onto the first surface of the film material after step a, and then irradiated for 20 minutes using an infrared radiation heater at 120℃, an infrared wavelength of 5μm, and a power density of 3 W / cm² to induce crystallization, thus obtaining COF. S layer; Step c, Preparation of IL-Si dynamic crosslinking layer: Take 133.3g of methacryloyloxypropyltrimethoxysilane, 222.2g of [BMIM][TFSI], 44.5g of Irgacure 1173, and 600g of ethanol solvent, mix them evenly, and then coat them on the second side of the membrane material completed in step b. After that, place them in an 80℃ temperature-controlled oven for pre-drying for 5 minutes. Step d, Dynamic cross-linking treatment: The second coating layer is sequentially irradiated with ultraviolet (UV) light at a wavelength of 365 nm and an intensity of 400 MW / cm².2 After irradiation for 30 seconds, infrared thermal field treatment was performed in a temperature-controlled oven equipped with an infrared radiator: firstly, a primary temperature zone of 110℃ for 90 seconds, infrared wavelength of 4.0μm, and IR power density of 4W / cm². 2 Secondly, the temperature range is 150℃, the second-level temperature range is 120s, the infrared wavelength is 1.8μm, and the IR power density is 8W / cm². 2 The final temperature range was 190℃ for 60 seconds, with an infrared wavelength of 1.2μm and an IR power density of 12W / cm². 2 This forms a self-healing-proton conduction bifunctional network structure, resulting in an IL-Si dynamic cross-linking layer. Step e, Gradient annealing: The membrane material from step d is placed in a hot air circulating oven with continuous nitrogen blowing, heated to 130℃ at a heating rate of 1℃ / min, and treated for 4 hours. Then, it is heated to 170℃ at a heating rate of 0.5℃ / min and treated for 8 hours. Finally, it is naturally cooled to room temperature to obtain the desired proton exchange membrane, wherein COF S The layer thickness is 2μm, and the IL-Si dynamic cross-linking layer thickness is 3μm.

[0025] Example 2 Step a, Pretreatment of perfluorosulfonic acid base film: The perfluorosulfonic acid base film with a thickness of 12μm was subjected to plasma activation treatment. The plasma activation treatment conditions were: Ar and O2 mixed gas with a working gas volume ratio of 1:1, gas flow rate of 125mL / min, plasma excitation treatment for 120s / face, power of 90W, 6.9g KH-550 was dissolved in 210ml ethanol and 23.3ml water mixed solution, pH adjusted to 4.5 to obtain mixed solution, and then the base film after plasma activation treatment was placed in the mixed solution, soaked at 35℃ for 12min, and dried at 75℃ for 15min to complete the grafting. Step b, COF S Layer preparation: 10g of TpPa-SO3H with a sulfonic acid group density of 3.5mmol / g and a pore size of 1.5nm was dissolved in 89.8g of DMSO, and then 0.2g of sodium dodecylbenzenesulfonate was added. The mixture was ultrasonically treated at 800W and 40kHz for 50min to obtain sulfonated COF. S Solution, sulfonated COF S The solution was coated onto the first surface of the membrane material after step a, and then an infrared radiation heater was used at a temperature of 110°C, an infrared wavelength of 3 μm, and a power density of 2 W / cm². 2 COF was obtained by thermally inducing crystallization under irradiation for 20 minutes. S layer; Step c, Preparation of IL-Si dynamic crosslinking layer: Take 66.7g of methacryloyloxypropyltrimethoxysilane, 133.4g of [BMIM][TFSI], 16.7g of Irgacure 1173, and 453.3g of ethanol solvent, mix them evenly, and then coat them on the second side of the membrane material completed in step b. After that, place it in a temperature-controlled oven at 70℃ for pre-drying for 3.5min. Step d, Dynamic cross-linking treatment: The second coating layer is sequentially irradiated with ultraviolet (UV) light at a wavelength of 365 nm and an intensity of 300 MW / cm². 2 After irradiation for 75 seconds, infrared thermal field treatment was performed in a temperature-controlled oven equipped with an infrared radiator: firstly, a primary temperature zone of 95℃ for 60 seconds, infrared wavelength of 3.5μm, and IR power density of 3W / cm². 2 Secondly, the temperature range is 140℃ for 90 seconds, the infrared wavelength is 1.5μm, and the IR power density is 6.5W / cm². 2 The final temperature range was 180°C for 45 seconds, with an infrared wavelength of 1μm and an IR power density of 10W / cm². 2 This forms a self-healing-proton conduction bifunctional network structure, resulting in an IL-Si dynamic cross-linking layer. Step e, Gradient annealing: The membrane material from step d is placed in a hot air circulating oven with continuous nitrogen blowing, heated to 125℃ at a heating rate of 0.75℃ / min, and treated for 3 hours. Then, it is heated to 165℃ at a heating rate of 0.3℃ / min and treated for 6 hours. Finally, it is naturally cooled to room temperature to obtain the desired proton exchange membrane, wherein COF S The layer thickness is 1.25 μm, and the IL-Si dynamic cross-linking layer thickness is 2 μm.

[0026] Example 3 Step a, Pretreatment of perfluorosulfonic acid base film: The perfluorosulfonic acid base film with a thickness of 5μm was subjected to plasma activation treatment. The plasma activation treatment conditions were: Ar and O2 mixed gas with a working gas volume ratio of 1:1, gas flow rate of 50mL / min, plasma excitation treatment for 30s / face, power of 60W, 3.5g KH-550 was dissolved in 180ml ethanol and 20ml water mixed solution, the pH was adjusted to 4 to obtain a mixed solution, and then the base film after plasma activation treatment was placed in the mixed solution, soaked at 25℃ for 10min, and dried at 60℃ for 10min to complete the grafting. Step b, COF S Layer preparation: 5g of TpBD-(SO3H)2 with a sulfonic acid group density of 2.8mmol / g and a pore size of 2nm was dissolved in 94.8g of DMSO, and then 0.2g of sodium dodecylbenzenesulfonate was added. The mixture was ultrasonically treated at 800W and 40kHz for 45min to obtain sulfonated COF. SSolution, sulfonated COF S The solution was coated onto the first surface of the membrane material after step a, and then an infrared radiation heater was used at a temperature of 100°C, an infrared wavelength of 2μm, and a power density of 1 W / cm². 2 COF was obtained by irradiation for 10 minutes to induce crystallization. S layer; Step c, Preparation of IL-Si dynamic crosslinking layer: Take 33.3g of methacryloyloxypropyltrimethoxysilane, 66.7g of [BMIM][TFSI], 3.3g of Irgacure 1173, and 206.7g of ethanol solvent, mix them evenly, and then coat them on the second side of the membrane material completed in step b. Then place them in a temperature-controlled oven at 60℃ for pre-drying for 2 minutes. Step d, Dynamic cross-linking treatment: The second coating layer is sequentially irradiated with ultraviolet (UV) light at a wavelength of 365 nm and an intensity of 200 MW / cm². 2 Irradiation for 120 seconds, followed by infrared thermal field treatment in a temperature-controlled oven equipped with an infrared radiator: firstly, a primary temperature zone of 110℃ for 90 seconds, infrared wavelength of 4μm, and IR power density of 4W / cm². 2 Secondly, the temperature range is 150℃, the second-level temperature range is 120s, the infrared wavelength is 1.8μm, and the IR power density is 8W / cm². 2 The final temperature range was 190℃ for 60 seconds, with an infrared wavelength of 1.2μm and an IR power density of 12W / cm². 2 This forms a self-healing-proton conduction bifunctional network structure, resulting in an IL-Si dynamic cross-linking layer. Step e, Gradient annealing: The membrane material from step d is placed in a hot air circulating oven with continuous nitrogen blowing, heated to 120℃ at a heating rate of 0.5℃ / min, and treated for 2 hours. Then, it is heated to 160℃ at a heating rate of 0.2℃ / min and treated for 4 hours. Finally, it is allowed to cool naturally to room temperature to obtain the desired proton exchange membrane, wherein the COF... S The layer thickness is 0.5 μm, and the IL-Si dynamic cross-linking layer thickness is 1 μm.

[0027] Example 4 This embodiment provides a roll-to-roll production line for preparing proton exchange membranes. The production line includes a PLC system, a circuit system, and a conveying mechanism, such as... Figure 1 As shown, the conveying mechanism includes a base film unwinding roller, a base film take-up roller, and a conveying roller, located between the base film unwinding roller and the base film take-up roller, and sequentially configured as a plasma activation zone, a grafting impregnation tank, a first drying unit, a first coating zone, a hot zone drying unit, a steering roller assembly, a second coating zone, a pre-drying unit, a UV irradiation heating zone, and an infrared hot zone heating zone along the conveying direction of the conveying mechanism. The plasma activation zone includes a plasma processing chamber, a vacuum pump for evacuating the plasma processing chamber, and a gas source pipe for injecting gas into the plasma processing chamber. The plasma processing chamber is equipped with a pair of electrode plates parallel to the base film being transported, and they are respectively placed above and below the base film being transported. The hot zone drying unit is an infrared radiation heater integrated into the production line; Both the first and second coating areas are coated using a slotted coating head. The UV irradiation heating zone includes UV lamps that irradiate the second surface of the membrane material. The infrared thermal field heating zone includes a temperature-controlled oven with an integrated infrared radiator. Inside the temperature-controlled oven, along the conveying direction of the conveying mechanism, there are three temperature zones in sequence: a primary temperature zone (80-110℃), a secondary temperature zone (130-150℃), and a tertiary temperature zone (170-190℃).

[0028] Example 5 This embodiment provides a method for preparing a proton exchange membrane using the production line of Example 4. The specific steps are as follows: S1. A perfluorosulfonic acid-based film with a thickness of 20μm is placed in the production line and conveyed by a tensioning mechanism with a linear speed of 1.5m / min. S2. The perfluorosulfonic acid-based membrane is transferred to the plasma processing chamber. The vacuum pump in the plasma activation zone is started to reduce the pressure in the plasma processing chamber to 40 Pa. A mixture of Ar and O2 with a volume ratio of 1:1 is introduced into the plasma processing chamber through the gas source pipe at a flow rate of 200 mL / min. The radio frequency power supply of the electrode plate is started to achieve plasma excitation treatment of the upper and lower surfaces of the perfluorosulfonic acid-based membrane for 120 s, with a power of 120 W during this process. S3. Preparation of silane coupling agent solution: Dissolve 500g KH-550 in 25L of ethanol and water mixed solvent, adjust the pH to 5, mix to form a mixed solution, and pour it into the grafting impregnation tank. Control the temperature at 40°C. The perfluorosulfonic acid base membrane is impregnated in the grafting impregnation tank for 15min under the conveying mechanism and is continuously conveyed to achieve the grafting reaction. Then, it is dried in the first drying unit at 80°C under vacuum for 20min to complete the silane coupling agent grafting reaction. S4. Preparation of sulfonated COFs solution: Dissolve 1.5 kg of TpPa-SO3H (sulfonic acid base density 4 mmol / g, pore size 1.2 nm) in 8.48 kg of DMSO, then add 0.02 kg of sodium dodecylbenzenesulfonate. After ultrasonic treatment at 800 W, 40 kHz for 60 min, place the solution in the loading system of the first coating zone. The perfluorosulfonic acid film from S3 is then conveyed to the first coating zone by the conveying mechanism. The sulfonated COFs solution is coated on the first surface of the perfluorosulfonic acid film at a coating speed of 0.8 m / min. Afterwards, it undergoes thermal field-induced crystallization treatment at 120°C for 20 min in the thermal field drying unit, thus forming COFs on the first surface of the perfluorosulfonic acid film. S layer; S5. Preparation of ionic liquid functionalized siloxane (IL-Si) dynamic crosslinking agent solution: Take 13.33 kg of methacryloyloxypropyltrimethoxysilane, 22.22 kg of [BMIM][TFSI], 4.45 kg of Irgacure 1173, and 60 kg of ethanol solvent, disperse and mix them evenly, and place them in the feeding system of the second coating zone. The perfluorosulfonic acid-based film completed in S4 is rotated 180° under the action of the steering roller assembly, and then continues to be conveyed to the second coating zone under the conveying mechanism. In the second coating zone, the ionic liquid functionalized siloxane (IL-Si) dynamic crosslinking agent solution is sprayed on the other side at a spraying rate of 400 mL / min. Then, it is pre-dried at 80°C for 5 min in the pre-drying unit. S6. The second coating layer is sequentially irradiated with ultraviolet (UV) light, with a wavelength of 365nm and an intensity of 400mW / cm². 2 After irradiation for 30 seconds, the sample is transferred to a temperature-controlled oven with an integrated infrared radiator for sequential infrared thermal field treatment: first, a primary temperature zone of 110℃ for 90 seconds, infrared wavelength of 4.0μm, and IR power density of 4W / cm². 2 Secondly, the temperature range is 150℃, the second-level temperature range is 120s, the infrared wavelength is 1.8μm, and the IR power density is 8W / cm². 2 The final temperature range was 190℃ for 60 seconds, with an infrared wavelength of 1.2μm and an IR power density of 12W / cm². 2 This forms a self-healing-proton conduction bifunctional network structure, resulting in an IL-Si dynamic cross-linking layer. S7. After the membrane material from S6 is wound into a roll at the take-up roller, it is manually fed into a hot air circulating oven with continuous nitrogen blowing. The temperature is increased to 130°C at a rate of 1°C / min and treated for 4 hours. Then, the temperature is increased to 170°C at a rate of 0.5°C / min and treated for 8 hours. Finally, it is naturally cooled to room temperature to obtain the desired proton exchange membrane, in which COF... S The layer thickness is 2μm, and the IL-Si dynamic cross-linking layer thickness is 3μm.

[0029] Comparative Example 1 The preparation method is the same as in Example 1, except that step b is omitted. The remaining steps are the same as in Example 1, namely: IL-Si dynamic cross-linking layers are prepared on both sides of the perfluorosulfonic acid base film after step a, and then both sides are subjected to ultraviolet (UV) irradiation, infrared thermal field treatment and gradient annealing treatment in sequence.

[0030] Comparative Example 2 The preparation method is the same as in Example 1, except that steps c and d are omitted, while the remaining steps are the same as in Example 1, namely: COF is prepared on both sides of the perfluorosulfonic acid-based membrane after step a. S The layers are then subjected to gradient annealing.

[0031] Comparative Example 3 The preparation method is the same as in Example 1, except that step c, the preparation of the IL-Si dynamic crosslinking layer, is changed to: taking 133.3g of methacryloyloxypropyltrimethoxysilane, 44.5g of Irgacure 1173, and 600g of ethanol solvent, mixing them evenly, and coating them on the second side of the film material after step a, and then placing them in an 80°C temperature-controlled oven for pre-drying for 5 minutes to obtain the IL-Si dynamic crosslinking layer, with the remaining steps unchanged.

[0032] Comparative Example 4 The preparation method is the same as in Example 1, except that the preparation of the grafting solution and the impregnation process in step a are omitted, while the other steps remain unchanged.

[0033] Comparative Example 5 The preparation method is the same as in Example 1, except that the plasma treatment in step a is omitted and the grafting and coating processes are performed directly, while the other steps remain unchanged.

[0034] Comparative Example 6 The preparation method is the same as in Example 1, except that the UV+IR treatment in step d is omitted, while the other steps remain unchanged.

[0035] Comparative Example 7 The preparation method is the same as in Example 1, except that step d, the dynamic crosslinking treatment, is replaced by irradiating the second coating layer with ultraviolet light (UV) at a wavelength of 365 nm and an intensity of 400 mW / cm. 2 Irradiate for 30 seconds, then treat in a single temperature zone of 140℃ in the infrared thermal field for 180 seconds, with the remaining steps unchanged.

[0036] Comparative Example 8 The preparation method is the same as in Example 1, except that step e, gradient annealing, is replaced by placing the film material that has completed step d in a hot air circulating oven with continuous nitrogen blowing, and annealing it at a constant temperature of 170°C for 12 hours. The other steps remain unchanged.

[0037] Performance tests were conducted on Examples 1-3 and Comparative Examples 1-8. Samples were placed in a constant temperature and humidity chamber (80℃, 30%RH) for 24 hours until swelling equilibrium was reached. Samples were then quickly removed, and dimensional measurements were performed within 30 seconds to determine the swelling rate. Proton conductivity was obtained using electrochemical impedance spectroscopy (EIS) with an electrochemical workstation. Standard scratches (depth ≈ 50% film thickness, length 1 cm) were created on the film surface using a microblade. Damaged samples were placed under self-healing conditions (80℃, 90%RH) for 24 hours, and tensile strength before and after repair was tested. Self-healing efficiency = damage amount / repair amount × 100%. After pressing the sample with a PET protective film, a universal testing machine was used to peel it 180° at a speed of 10 mm / min. The peel force F (N) was recorded, and the interfacial bonding strength (N / cm) was calculated. The test results are shown in Table 1.

[0038] Table 1

[0039] Comparative Example 1 does not contain COF S The performance defects of the IL-Si layer are manifested in high swelling ratio, low proton conductivity, and lack of self-healing ability. The root cause lies in the fact that without the COFs layer, the system relies solely on random ion clusters in the base film for proton conduction, and lacks a rigid framework to suppress water absorption and swelling. Furthermore, although the self-healing function is provided by the dynamic chemical bonds in the IL-Si layer, its dynamic network requires the rigid framework of the COFs layer to provide mechanical support to maintain structural stability. In Comparative Example 1, without the COFs layer, the IL-Si layer is prone to irreversible deformation under mechanical stress or swelling, resulting in the inability of dynamic bonds to effectively recombine and repair cracks; and without the mechanical support provided by the COFs layer, interlayer separation is easily caused by tension during roll-to-roll processes.

[0040] Comparative Example 2, lacking the IL-Si dynamic crosslinking layer, exhibits performance defects in poor interfacial adhesion and weak self-healing ability. The root cause lies in the absence of the IL-Si layer; COFs and the base film are only bonded through hydrogen bonds, resulting in insufficient interfacial bonding strength. Furthermore, the absence of the dynamic crosslinking network leads to stress buffer failure, preventing crack repair. However, plasma activation introduces functional groups, enhancing the adhesion between the coating and the base film. This treatment can inhibit crack propagation through physical anchoring, indirectly slowing damage accumulation and exhibiting a similar "self-healing" appearance.

[0041] In Comparative Example 3, the IL-Si solution lacks an ionic liquid, resulting in performance defects such as low proton conductivity and increased swelling ratio. The fundamental reason is that the IL-Si layer lacks an ionic liquid, leading to insufficient dynamic network plasticization. Proton transport relies on the siloxane framework, and the decreased hydrophobicity causes exacerbated water absorption and swelling.

[0042] In Comparative Example 4, which lacks a grafted layer, performance defects manifest as coating peeling, extremely high swelling rate, and no self-healing ability. The fundamental reason is that the grafted layer enhances the adhesion between the IL-Si layer and the base film through covalent and hydrogen bonds. Without a grafted layer, the IL-Si layer only bonds through physical adsorption, resulting in weak interfacial adhesion and easy peeling of the coating from the base film (e.g., ...). Figure 2 As shown in the figure, the dynamic key repair function cannot be triggered; the interface separates during volume-to-volume transfer, and swelling becomes uncontrollable after absorbing water.

[0043] In Comparative Example 5, which did not undergo plasma activation, performance defects were observed in interface delamination and a high swelling ratio. The root cause was the lack of plasma activation, resulting in low hydroxyl density on the base film surface, insufficient KH-550 grafting rate, and poor coating adhesion.

[0044] In Comparative Example 6, which lacked UV+IR treatment, performance defects manifested as low self-healing efficiency and localized shrinkage. The root cause was the absence of UV / IR synergistic crosslinking, resulting in insufficient curing of dynamic bonds, poor network stability, and localized shrinkage upon heating.

[0045] In Comparative Example 7, the IR irradiation was not divided into three temperature zones, resulting in performance defects such as uneven pore volume and decreased proton conductivity. The root cause is that the single-temperature IR treatment leads to insufficient siloxane condensation, poor COF pore connectivity, and obstructed ion transport pathways.

[0046] In Comparative Example 8, the lack of gradient annealing resulted in performance defects such as microcracks and a slight decrease in proton conductivity. The root cause lies in the absence of gradient annealing; rapid heating leads to residual internal stress, disordered arrangement of COF channels, and uneven distribution of ion clusters.

[0047] In summary, the embodiments of this invention employ a synergistic dual-functional layer of COFs and IL-Si. COFs provide rigid support and proton channels, while the dynamic network of IL-Si enhances self-healing and interfacial bonding. Furthermore, the process utilizes plasma activation and grafting to improve interfacial bonding, and UV / IR graded curing and gradient annealing to optimize the network structure and stability. Moreover, the mechanical properties (crack-free, flexible, and ductile) of Examples 1-3 all meet the requirements for roll-to-roll production. In contrast, the comparative examples, due to issues such as coating peeling and delamination, cannot be adapted to continuous production. Comparative examples 1-2 suffer from performance imbalances due to missing functional layers, such as uncontrolled swelling or interfacial delamination. Comparative examples 3-8 involve simplification of key components or processes, disrupting the integrity or structural order of the dynamic network; therefore, their performance is inferior to that of Examples 1-3.

[0048] The above specific embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A method for preparing a proton exchange membrane, characterized in that, Includes the following steps: Step 1: The perfluorosulfonic acid-based membrane is plasma activated on both sides, and then grafted by immersion in a silane coupling agent solution. Step 2: Coat the first side of the perfluorosulfonic acid-based film obtained in Step 1 with sulfonated COF. S The solution, induced by an infrared thermal field, crystallizes to form COF. S layer; Step 3: After coating the second surface with an ionic liquid-functionalized siloxane dynamic crosslinking agent solution, pre-dry the coating layer and then irradiate it with ultraviolet light. Subsequently, dynamic crosslinking is performed using a three-level gradient temperature control and infrared thermal field coupling. The ionic liquid-functionalized siloxane dynamic crosslinking agent solution contains siloxane prepolymer, ionic liquid, photoinitiator and ethanol solvent. Step 4: Perform gradient annealing on the membrane material obtained in Step 3 to obtain the proton exchange membrane.

2. The preparation method according to claim 1, characterized in that: In step 1, the conditions for plasma activation are as follows: the working gas is a mixture of Ar and O2 with a volume ratio of 1:1, the gas flow rate is 50-200 mL / min, the plasma excitation treatment time is 30-120 s / face, and the power is 60-120 W. The method for grafting silane coupling agent is as follows: the plasma-activated perfluorosulfonic acid-based membrane is immersed in a silane coupling agent solution for grafting, and then dried; wherein the immersion temperature is 25-40℃ and the time is 10-15min; the drying temperature is 60-80℃ and the time is 10-20min. The silane coupling agent solution is a 3-aminopropyltriethoxysilane solution with a mass concentration of 2-5 wt%; 3-aminopropyltriethoxysilane is mixed with a mixed solvent, stirred, and the pH is adjusted to 4-5 to obtain the 3-aminopropyltriethoxysilane solution; the mixed solvent is ethanol and water with a volume ratio of 9:

1.

3. The preparation method according to claim 1, characterized in that, In step 2, the infrared thermal field-induced crystallization uses an infrared radiation heater with an infrared wavelength of 2-5 μm and a power density of 1-3 W / cm². 2 The temperature for thermal field-induced crystallization is 100-120℃, and the time is 10-20 min. The sulfonated COF S The solution preparation steps are as follows: In the sulfonated COF... S Sodium dodecylbenzenesulfonate was added to a mixture of sodium dodecylbenzenesulfonate and DMSO to achieve a concentration of 0.2 wt%. The mixture was then sonicated at 40 kHz and 800 W for 45-60 min to obtain sulfonated COF. S Solution, in which sulfonated COF S Sulfonated COF in a mixture of DMSO S The mass concentration is 5-15 wt%, sulfonated COF S It is one of TpPa-SO3H and TpBD-(SO3H)2, wherein the pore size of TpPa-SO3H is 1.2-1.8 nm and the sulfonic acid group density is 3-4 mmol / g, and the pore size of TpBD-(SO3H)2 is 1.8-2.4 nm and the sulfonic acid group density is 2.8-3.6 mmol / g.

4. The preparation method according to claim 1, characterized in that, In step 3, the pre-drying temperature is 60-80℃ and the time is 2-5 minutes; The mass ratio of siloxane prepolymer, ionic liquid, and photoinitiator is (1-3):(2-5):(0.1-1), and the solid content is 20-40 wt%. The siloxane prepolymer is methacryloyloxypropyltrimethoxysilane, the ionic liquid is [BMIM][TFSI], and the photoinitiator is one of Irgacure 1173 and Irgacure 184.

5. The preparation method according to claim 1, characterized in that, In step 4, the ultraviolet light irradiation time is 30-120 seconds; The coupling parameters of the three-level gradient temperature control and infrared thermal field are as follows: Level 1 temperature zone: 80-110℃, irradiation time: 30-90s; Level 2 temperature zone: 130-150℃, irradiation time: 60-120s; Level 3 temperature zone: 170-190℃, irradiation time: 30-60s.

6. The preparation method according to claim 1, characterized in that, In step 5, the gradient annealing conditions are as follows: the first stage annealing temperature is 120-130℃, the time is 2-4h, and the heating rate is ≤1℃ / min; the second stage annealing temperature is 160-170℃, the time is 4-8h, and the heating rate is ≤0.5℃ / min.

7. The proton exchange membrane prepared by the method according to any one of claims 1-6, characterized in that: The membrane includes a perfluorosulfonic acid-based membrane, one side of which is provided with a COFs layer and the other side of which is provided with an IL-Si dynamic crosslinking layer. The thickness of the perfluorosulfonic acid-based film is 5-20 μm, and the COF... S The thickness of the layer is 0.5-2 μm, and the thickness of the IL-Si dynamic crosslinking layer is 1-3 μm.

8. A roll-to-roll production line for preparing the proton exchange membrane according to any one of claims 7, characterized in that, The production line has a conveying mechanism, which includes a base film unwinding roller, a base film take-up roller, and a conveying roller located between the base film unwinding roller and the base film take-up roller. Along the conveying direction of the conveying mechanism, the roller is sequentially configured as a plasma activation zone, a grafting impregnation tank, a first drying unit, a first coating zone, a hot zone drying unit, a steering roller assembly, a second coating zone, a pre-drying unit, a UV irradiation heating zone, and an infrared hot zone heating zone. The plasma activation zone includes a plasma treatment chamber, a vacuum pump for evacuating the plasma treatment chamber, and a gas source pipe for injecting gas into the plasma treatment chamber. The plasma treatment chamber contains a pair of electrode plates parallel to the conveyed base film, positioned above and below the conveyed base film, respectively. The infrared thermal field heating zone includes a temperature-controlled oven with an integrated infrared radiator. The temperature-controlled oven contains a primary temperature zone, a secondary temperature zone, and a tertiary temperature zone, arranged sequentially along the conveying direction of the conveying mechanism.

9. A method for preparing a proton exchange membrane using the production line described in claim 8, characterized in that, Includes the following steps: S1. Place the perfluorosulfonic acid-based film in the production line and convey it under tension by a conveying mechanism with a linear speed of 1-1.8 m / min. S2. The perfluorosulfonic acid-based membrane is transferred to the plasma processing chamber for plasma activation treatment of both the upper and lower surfaces of the perfluorosulfonic acid-based membrane. The plasma activation time is 30-120s / side. S3. Pour the silane coupling agent solution into the grafting impregnation tank and control the temperature at 25-40℃. The perfluorosulfonic acid base film is impregnated in the grafting impregnation tank under the conveying mechanism and continuously conveyed for 10-15 minutes to achieve the grafting reaction. Then, it is dried in the first drying unit at 60-80℃ under vacuum for 10-20 minutes to complete the silane coupling agent grafting reaction. S4, Preparation of sulfonated COF S The solution is placed in the feeding system of the first coating area. The perfluorosulfonic acid-based film, which completes S3, arrives at the first coating area under the conveying mechanism. Sulfonated COF is then coated on the first surface of the perfluorosulfonic acid-based film. S The solution was coated at a speed of 0.5-0.8 m / min, followed by thermal field-induced crystallization treatment at 100-120℃ for 10-20 min in a thermal field drying unit, which forms COF on the first surface of the perfluorosulfonic acid-based film. S layer; S5. Prepare a solution of ionic liquid functionalized siloxane dynamic crosslinking agent and place it in the feeding system of the second coating zone. The perfluorosulfonic acid-based film completed in S4 is rotated 180° under the action of the steering roller assembly. Then, it is conveyed to the second coating zone by the conveying mechanism. In the second coating zone, the solution of ionic liquid functionalized siloxane dynamic crosslinking agent is sprayed on the second side at a spraying rate of 50-400 mL / min. Then, it is pre-dried at 60-80℃ for 2-5 min in the pre-drying unit. S6. Irradiate the second coating layer with ultraviolet light sequentially. The ultraviolet light wavelength is 365nm and the intensity is 200-400MW / cm. 2 The irradiation time is 30-120s. The second coating layer is irradiated using a three-step temperature-controlled coupled infrared thermal field within the infrared thermal field region. Along the film material's transport direction, the irradiation sequence is as follows: First-level temperature zone 80-110℃, irradiation time 30-90s, infrared wavelength 3.0-4.0μm, infrared power density 2-4W / cm². 2 Secondary temperature range: 130-150℃; irradiation time: 60-120s; infrared wavelength: 1.2-1.8μm; infrared power density: 5-8W / cm². 2 The temperature range is 170-190℃ (Level 3), the irradiation time is 30-60s, the infrared wavelength is 0.8-1.2μm, and the infrared power density is 8-12W / cm². 2 ; S7. After the membrane material from S6 is wound up at the take-up roller, it is manually fed into a hot air circulating oven with continuous nitrogen blowing. The temperature is raised to 120-130℃ at a heating rate of ≤1℃ / min and treated for 2-4 hours. Then, the temperature is raised to 160-170℃ at a heating rate of ≤0.5℃ / min and treated for 4-8 hours. Finally, it is naturally cooled to room temperature to obtain the proton exchange membrane.

10. The method according to claim 9, characterized in that: In step S2, the specific steps for plasma activation are as follows: A. The perfluorosulfonic acid-based film is fixed on the conveyor mechanism of the production line and conveyed to the plasma activation zone; B. Start the vacuum pump in the plasma activation zone to reduce the pressure in the plasma processing chamber to below 50 Pa; C. Introduce a 1:1 mixture of Ar and O2 gas into the plasma processing chamber through a gas source pipe at a flow rate of 50-200 mL / min. D. Start the radio frequency power supply of the electrode plate to achieve plasma excitation treatment on both sides of the perfluorosulfonic acid-based film. The treatment time is 30-120s and the power is 60-120W.

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