Preparation method and application of o-PBI / PPS alkaline water electrolysis diaphragm

Abstract

The invention provides a preparation method of an o-PBI / PPS alkaline water electrolysis diaphragm. The method comprises the following steps: preparing a hydrophilic PPS woven membrane, preparing o-PBI, adding o-PBI into an organic solvent, then blade-coating the surface of the hydrophilic PPS woven membrane, uniformly covering, soaking in deionized water, and carrying out vacuum drying to obtain the o-PBI / PPS alkaline water electrolysis diaphragm. The invention also provides an application of the o-PBI / PPS alkaline water electrolysis diaphragm, and the o-PBI / PPS alkaline water electrolysis diaphragm is applied to the preparation method of the o-PBI / PPS alkaline water electrolysis diaphragm. According to the invention, o-PBI is loaded on the surface of the hydrophilic PPS woven membrane to form a membrane, a compact and fine pore structure is formed, and the substrate hydrophilic PPS woven membrane has strong hydrophilicity, so that relatively high air tightness and relatively good water electrolysis performance are realized. The diaphragm can be used in an alkaline water electrolytic bath and is responsible for blocking gas and permeating alkaline liquor.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of alkaline water electrolysis diaphragm, and particularly relates to a preparation method and application of an o-PBI / PPS alkaline water electrolysis diaphragm. BACKGROUND

[0002] Alkaline water electrolysis (AWE) is a mature water electrolysis technology at present, and is also the earliest developed water electrolysis technology, and is widely considered as a safe and long service life water electrolysis technology, so it is favored by people. AWE usually takes 30wt% KOH solution as an electrolyte, and after a power supply is input, H2 is reduced near the cathode, and O2 is released near the anode. As a core component of an alkaline electrolytic tank, the diaphragm mainly plays two roles, one is to serve as OH - A channel from the cathode to the anode, and the other is to prevent H2 and O2 from mixing and to prevent safety accidents. The earliest diaphragm is an asbestos diaphragm, but it has been abandoned due to safety problems, and the most widely used diaphragm at present is a polyphenylene sulfide (PPS) diaphragm.

[0003] The PPS molecular chain is composed of benzene rings and thioether bonds (-S-), which makes PPS have high rigidity, and the corrosion resistance, thermal stability and anti-creep property thereof are very excellent. The PPS diaphragm has excellent stability in alkaline solution, but the large pore size thereof will cause obvious gas cross to reduce the safety performance of the alkaline electrolytic tank. At the same time, due to the hydrophobicity of the PPS film, the PPS film is not easy to be infiltrated by the electrolyte, and the bubbles are also gathered at the joint of the diaphragm and the electrolyte, which increases the surface resistance of the PPS and reduces the electrolysis efficiency. Therefore, it is very important to improve the gas tightness and hydrophilicity of the PPS diaphragm. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a preparation method and application of an o-PBI / PPS alkaline water electrolysis diaphragm, which utilizes o-PBI to load on the surface of a hydrophilic PPS woven film to form a dense and small pore structure, fills the pores of the PPS woven film, and increases the gas tightness of the composite diaphragm, and the substrate hydrophilic PPS woven film has strong hydrophilicity, so that high gas tightness and good water electrolysis performance are realized. The o-PBI / PPS alkaline water electrolysis diaphragm prepared by the present application can be used in an alkaline water electrolytic tank, and is responsible for the diaphragm for blocking gas and permeating alkaline solution.

[0005] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a preparation method of an o-PBI / PPS alkaline water electrolysis diaphragm, which comprises the following steps: S1, preparation of a PPS woven film: Polyphenylene sulfide fibers are woven to obtain a PPS woven film; S2, preparation of a hydrophilic PPS woven film: The PPS braided film obtained in S1 is soaked in anhydrous ethanol for 24-30 hours, vacuum dried at 60 DEG C, dried PPS braided film is obtained, then soaked in 38-44% mass fraction nitric acid aqueous solution at 50 DEG C for 2-3 hours, washed with deionized water until the surface pH value is 7, vacuum dried at 80 DEG C, and then a hydrophilic PPS braided film is obtained. Compared with the traditional sulfonated hydrophilic modification method, the hydrophilic modification of the PPS braided film by nitric acid aqueous solution has a relatively mild condition, a simple post-treatment process, and is beneficial to maintaining the stability of the PPS diaphragm. S3, preparation of o-PBI: Polyphosphoric acid (PPA) is used as a solvent, 3,3',4,4'-tetraaminobiphenyl (DAB) and 4,4'-diphenyl ether dicarboxylic acid (OBBA) are subjected to polycondensation reaction, and polyaryletherbenzimidazole, i.e. o-PBI, is obtained. S4, o-PBI obtained in S3 is added to an organic solvent, stirred and dissolved at room temperature, and then an o-PBI-containing organic solution is obtained. S5, the o-PBI-containing organic solution obtained in S4 is poured onto the outer side of the hydrophilic PPS braided film obtained in S2, and then the o-PBI-containing organic solution is scraped onto the surface of the hydrophilic PPS braided film, and after uniform covering, a hydrophilic PPS braided film loaded with o-PBI is obtained, then soaked in deionized water for 24-26 hours, taken out, and vacuum dried, and then o-PBI / PPS alkaline water electrolysis diaphragm is obtained.

[0006] The use of o-PBI fills the pores of the PPS braided film, so that the finally prepared o-PBI / PPS alkaline water electrolysis diaphragm has improved air tightness.

[0007] In the present application, o-PBI and hydrophilic PPS braided film are compounded to improve the air tightness, and the hydrophilic PPS braided film with good hydrophilicity is used instead of the commonly used hydrophobic polysulfone (PSU), which effectively alleviates the decrease of hydrophilicity after compounding, and improves the air tightness and mechanical properties of the diaphragm.

[0008] Preferably, the vacuum drying time of S2 at 60 DEG C is 24 hours; the vacuum drying time of S2 at 80 DEG C is 24 hours.

[0009] Preferably, the amount ratio of 3,3',4,4'-tetraaminobiphenyl, 4,4'-diphenyl ether dicarboxylic acid and polyphosphoric acid in S3 is 4.2854:5.1646:200.

[0010] Preferably, the specific preparation method of the o-PBI is as follows: Preheat the polyphosphoric acid at 60℃ for 0.5h, then heat the preheated polyphosphoric acid to 120℃ under nitrogen atmosphere, stir at 120r / min for 0.5h, then add 3,3',4,4'-tetraaminobiphenyl, stir at 300r / min for 3h, then add 4,4'-oxybisbenzoic acid, stir at 300r / min for 2h, then heat to 140℃ at a rate of 1℃ / min, stir at 300r / min for 3.5h, then heat to 170℃ at a rate of 1℃ / min, stir at 300r / min for 3h, then heat to 200℃ at a rate of 1℃ / min, and react for 4h, then wash the obtained product with deionized water, sodium carbonate aqueous solution, deionized water and anhydrous ethanol in sequence, and vacuum dry the washed product to obtain the poly (arylene ether benzimidazole), i.e. the o-PBI.

[0011] Preferably, the method for washing with the sodium carbonate aqueous solution is washing with a 5% sodium carbonate aqueous solution at room temperature for 24h; and the vacuum drying condition is 60℃ for 24h.

[0012] Preferably, the organic solvent in S4 is N-methylpyrrolidone, dimethylacetamide, dimethylformamide or dimethyl sulfoxide.

[0013] Preferably, the mass ratio of the o-PBI to the organic solvent in S4 is (0.25-0.625):(4.375-4.75), and the stirring and dissolving time in S4 is 6h.

[0014] Preferably, the vacuum drying condition in S5 is 60℃ for 24h.

[0015] Preferably, the o-PBI / PPS alkaline water electrolysis separator has a water contact angle of 68.9°-89.3°, an average pore size of 0.106μm-16μm, a bubble point pressure of 0.4kPa-3.28kPa, and a surface resistance of 0.71Ω·cm at 80℃. 2 ~3.75Ω·cm 2 .

[0016] The application further provides an application of the o-PBI / PPS alkaline water electrolysis separator prepared by the above preparation method, and the o-PBI / PPS alkaline water electrolysis separator is used in an alkaline water electrolysis tank.

[0017] Compared with the prior art, the application has the following advantages: The application utilizes o-PBI to load film formation on the surface of the hydrophilic PPS woven film, forms a dense and small pore structure, fills the pores of the PPS woven film, makes the composite diaphragm gas tightness rise, and the substrate hydrophilic PPS woven film has strong hydrophilicity, realizes higher gas tightness and better electrolytic water performance. The o-PBI / PPS alkaline water electrolysis diaphragm prepared in the application can be used in an alkaline water electrolysis tank, and is responsible for blocking gas and permeating alkali solution.

[0018] The application will be further described in detail below in combination with examples. DETAILED DESCRIPTION

[0019] Example 1 The preparation method of the o-PBI / PPS alkaline water electrolysis diaphragm in the example is as follows: S1, preparation of PPS woven film: The polyphenylene sulfide fiber is woven to obtain the PPS woven film; Specifically, 1000 D polyphenylene sulfide (PPS) fiber is woven into a film using a semi-automatic loom. First, 16 fibers are evenly fixed on the rack to ensure consistent tension, then 16 groups of fibers are fixed as warp threads in the same way, then the variable amount of yarn is put into the shuttle as weft, and finally the woven program of twill is followed to weave the PPS woven film; S2, preparation of hydrophilic PPS woven film: A piece (5 cm x 5 cm) of the PPS woven film obtained in S1 is cut, soaked in anhydrous ethanol for 24 h, then vacuum dried at a temperature of 60℃ for 24 h to obtain the dried PPS woven film, then soaked in a 44% mass fraction nitric acid aqueous solution at a temperature of 50℃ for 2 h, washed with deionized water until the surface pH value is 7, and then vacuum dried at a temperature of 80℃ for 24 h to obtain the hydrophilic PPS woven film; The water contact angle is reduced from 127.8° (PPS woven film) to 43.85° (hydrophilic PPS woven film), the average pore size is 70 μm, the bubble point pressure is 0.25 kPa, and the surface resistance at 80℃ is 0.41 Ω•cm 2 ; S3, preparation of o-PBI: Using polyphosphoric acid (PPA) as a solvent, 3,3',4,4'-tetraaminobiphenyl and 4,4'-diphenyl ether dicarboxylic acid are subjected to condensation polymerization, and the specific reaction is as follows: The 200 g of polyphosphoric acid was preheated at 60 °C for 0.5 h, then the preheated polyphosphoric acid was heated to 120 °C under nitrogen atmosphere, and stirred at 120 r / min for 0.5 h, then 4.2854 g of 3,3',4,4'-tetraaminobiphenyl was added, and stirred at 300 r / min for 3 h, then 5.1646 g of 4,4'-oxybisbenzoic acid was added, and stirred at 300 r / min for 2 h, then heated to 140 °C at a rate of 1 °C / min, and stirred at 300 r / min for 3.5 h, then heated to 170 °C at a rate of 1 °C / min, and stirred at 300 r / min for 3 h, then heated to 200 °C at a rate of 1 °C / min, and stirred for 4 h, then the obtained product was washed with deionized water, and washed with 5% sodium carbonate aqueous solution at room temperature for 24 h, and washed with deionized water and anhydrous ethanol, and the washed product was vacuum dried at 60 °C for 24 h to obtain poly (arylene ether benzimidazole), i.e. o-PBI; The viscosity average molecular weight of the o-PBI prepared in this example was 8.7 kDa; S4, 0.25 g of the o-PBI obtained in S3 was added to 4.75 g of an organic solvent (dimethyl sulfoxide DMSO), and stirred and dissolved at room temperature for 6 h to obtain an organic solution containing o-PBI; S5, the organic solution containing o-PBI obtained in S4 was poured onto the outer side of the hydrophilic PPS woven film obtained in S2, and then a stainless steel scraper was used to blade coat the organic solution containing o-PBI to the surface of the hydrophilic PPS woven film (5 cm x 5 cm), and after uniform coverage, a hydrophilic PPS woven film loaded with o-PBI was obtained, which was then soaked in deionized water for 24 h, taken out, and vacuum dried at 60 °C for 24 h to obtain an o-PBI / PPS alkaline water electrolysis separator. The deionized water soaking in this step is a phase inversion process, which replaces the solvent in the organic solution containing o-PBI to form pores and obtain a porous structure; Test method: (1) Water contact angle was tested using a water contact angle tester. (2) Bubble point pressure and average membrane pore size were tested using a membrane pore size analyzer. The material cut into blocks was fully wetted with GQ-16 wetting liquid, and then placed in the tester and tested by introducing nitrogen. (3) Surface resistance was tested using a Shanghai Chenhua instrument model CHI 604E electrochemical analyzer at a frequency range of 1 kHz-1000 kHz with and without a separator. (4) Viscosity average molecular weight of the polymer was tested using a Ubbelohde viscometer.

[0020] The water contact angle of the o-PBI / PPS alkaline water electrolysis diaphragm prepared in the embodiment is 68.9°, the bubble point pressure is 0.4 kPa, and the surface resistance at 80°C is 1.37 Ω·cm. 2 .

[0021] The average pore size of the hydrophilic PPS woven film in step S5 in the embodiment is 70 μm, and the maximum pore size is 9.04%, while the average pore size of the o-PBI / PPS alkaline water electrolysis diaphragm finally prepared in the embodiment is 5 μm, and the maximum pore size is 114.40 μm, and the porosity is 19.86%, indicating that the average pore size is reduced from 70 μm to 5 μm. The reduction of the pore size can effectively block the penetration of hydrogen and oxygen, enhance the gas tightness of the diaphragm, and increase the bubble point pressure from 0.25 kPa to 0.4 kPa.

[0022] The increase of the porosity can provide more ion transmission channels, increase the connectivity between the pores, reduce the surface resistance, and improve the electrolysis efficiency. However, the reduction of the pore size will make the ion migration channel narrow, increase the flow resistance of the electrolyte in the pore, and enhance the interaction between the ions and the pore wall, resulting in an increase of the surface resistance. In order to obtain a lower surface resistance, the pore size and the porosity need to be balanced. The o-PBI / PPS alkaline water electrolysis diaphragm prepared in the embodiment has a relatively low surface resistance.

[0023] In addition, in order to illustrate the performance of the o-PBI prepared in step S3 in the embodiment, the o-PBI porous film is also prepared in the embodiment, and the performance is tested: The preparation method is as follows: the o-PBI-containing organic solution obtained in step S4 in the embodiment is poured on a clean glass plate, and a doctor blade is used to coat a film, and then a non-solvent induced phase separation method is used to prepare a porous film. After soaking in a non-solvent (water) for 24 h, it is taken out and dried in a vacuum oven at 80°C.

[0024] The principle of non-solvent induced phase separation is as follows: when the o-PBI-containing organic solvent phase is immersed in a non-solvent (usually water or alcohol), mutual diffusion occurs between the solvent and the non-solvent, resulting in a decrease in the thermodynamic stability of the polymer solution, and phase separation occurs, and finally a porous structure is formed.

[0025] The performance of the o-PBI porous film is as follows: a dense sponge-like pore structure is formed.

[0026] Therefore, in step S5 in the embodiment, the o-PBI-containing organic solution is coated on the surface of the hydrophilic PPS woven film to obtain a hydrophilic PPS woven film loaded with o-PBI. The dense and small pore structure of the o-PBI porous film can fill the pores of the PPS woven film, so that the gas tightness of the composite diaphragm is improved.

[0027] The present embodiment utilizes o-PBI to load on the surface of the hydrophilic PPS woven film to form a dense and fine pore structure and strong hydrophilicity of the substrate hydrophilic PPS woven film, so as to realize higher air tightness and better water electrolysis performance. The o-PBI / PPS alkaline water electrolysis diaphragm can be used in the alkaline water electrolysis tank to block gas and pass through the diaphragm of the alkaline solution.

[0028] Example 2 The preparation method of the o-PBI / PPS alkaline water electrolysis diaphragm of the present embodiment is as follows: S1, preparation of PPS woven film: The polyphenylene sulfide fibers are woven to obtain the PPS woven film; Specifically, 400 D polyphenylene sulfide (PPS) fibers are woven into a film using a semi-automatic loom. First, 16 fibers are evenly fixed on the rack as a group to ensure consistent tension. Then, 16 groups of fibers are fixed as the warp threads in the same way. After that, the yarn is put into the shuttle as the weft thread. Finally, the woven program of twill is followed to weave the PPS woven film. S2, preparation of hydrophilic PPS woven film: A piece of PPS woven film obtained in S1 is cut (5 cm x 5 cm), soaked in anhydrous ethanol for 30 h, and then vacuum dried at 60℃ for 24 h to obtain the dried PPS woven film. Then, the dried PPS woven film is soaked in a 38% mass fraction nitric acid aqueous solution at 50℃ for 3 h, washed with deionized water until the surface pH value is 7, and then vacuum dried at 80℃ for 24 h to obtain the hydrophilic PPS woven film. S3, preparation of o-PBI: Using polyphosphoric acid (PPA) as the solvent, 3,3',4,4'-tetraaminobiphenyl and 4,4'-diphenyl ether dicarboxylic acid are subjected to condensation polymerization, and the specific reaction is as follows: 200g of polyphosphoric acid was preheated at 60℃ for 0.5h, then the preheated polyphosphoric acid was heated to 120℃ under nitrogen atmosphere, and stirred at 120r / min for 0.5h, then 4.2854g of 3,3',4,4'-tetraaminobiphenyl was added, and stirred at 300r / min for 3h, then 5.1646g of 4,4'-oxybisbenzoic acid was added, and stirred at 300r / min for 2h, then heated to 140℃ at a rate of 1℃ / min, and stirred at 300r / min for 3.5h, then heated to 170℃ at a rate of 1℃ / min, and stirred at 300r / min for 3h, then heated to 200℃ at a rate of 1℃ / min, and reacted for 4h, then the obtained product was washed with deionized water, and washed with 5% sodium carbonate aqueous solution at room temperature for 24h, and washed with deionized water and anhydrous ethanol, and the washed product was vacuum dried at 60℃ for 24h to obtain poly (arylene ether benzimidazole), i.e. o-PBI; The viscosity average molecular weight of the o-PBI prepared in this example was 8.7 kDa; S4, 0.5g of the o-PBI obtained in S3 was added to 4.5g of an organic solvent (N-methyl pyrrolidone NMP), and stirred and dissolved at room temperature for 6h to obtain an organic solution containing o-PBI; S5, the organic solution containing o-PBI obtained in S4 was poured onto the outer side of the hydrophilic PPS woven film obtained in S2, and then a stainless steel scraper was used to blade coat the organic solution containing o-PBI to the surface of the hydrophilic PPS woven film (5cm×5cm), and after uniform coverage, a hydrophilic PPS woven film loaded with o-PBI was obtained, which was then soaked in deionized water for 26h, taken out, and vacuum dried at 60℃ for 24h to obtain an o-PBI / PPS alkaline water electrolysis separator; The o-PBI / PPS alkaline water electrolysis separator prepared in this example had a water contact angle of 72.7°, an average pore size of 16μm, a maximum pore size of 35.45μm, a porosity of 25.25%, a bubble point pressure of 1.45kPa, and a surface resistance of 0.71Ω·cm at 80℃ 2 .

[0029] Example 3 The preparation method of the o-PBI / PPS alkaline water electrolysis separator in this example was as follows: S1, preparation of PPS woven film: Polyphenylene sulfide fibers were woven to obtain a PPS woven film; The specific method is: using a semi-automatic loom to weave 1000 D polyphenylene sulfide (PPS) fibers into a film, first fixing 16 fibers as a group on the rack to ensure consistent tightness, then fixing 16 groups of fibers as warp threads in the same way, then putting the variable amount of yarn into the shuttle as weft threads, and finally weaving according to the weaving program of twill to obtain a PPS woven film; S2, preparation of a hydrophilic PPS woven film: A piece of the PPS woven film obtained in S1 is cut off (5 cm x 5 cm), soaked in anhydrous ethanol for 26 h, then vacuum dried at 60℃ for 24 h to obtain a dried PPS woven film, then soaked in a 40% mass fraction nitric acid aqueous solution at 50℃ for 2.5 h, washed with deionized water until the surface pH value is 7, and then vacuum dried at 80℃ for 24 h to obtain a hydrophilic PPS woven film; S3, preparation of o-PBI: Using polyphosphoric acid (PPA) as a solvent, 3,3',4,4'-tetraaminobiphenyl and 4,4'-diphenyl ether dicarboxylic acid are subjected to condensation polymerization, and the specific reaction is as follows: 200 g of polyphosphoric acid is preheated at 60℃ for 0.5 h, then heated to 120℃ under a nitrogen atmosphere, and stirred at a constant temperature for 0.5 h at a rotation speed of 120 r / min, then 4.2854 g of 3,3',4,4'-tetraaminobiphenyl is added, and stirred at a constant temperature for 3 h at a rotation speed of 300 r / min, then 5.1646 g of 4,4'-diphenyl ether dicarboxylic acid is added, and stirred at a constant temperature for 2 h at a rotation speed of 300 r / min, then heated to 140℃ at a heating rate of 1℃ / min, and stirred at a constant temperature for 3.5 h at a rotation speed of 300 r / min, then heated to 170℃ at a heating rate of 1℃ / min, and stirred at a constant temperature for 3 h at a rotation speed of 300 r / min, then heated to 200℃ at a heating rate of 1℃ / min, and stirred at a constant temperature for 4 h, then the obtained product is sequentially washed with deionized water, washed with a 5% mass fraction sodium carbonate aqueous solution at room temperature for 24 h, washed with deionized water, washed with anhydrous ethanol, and then vacuum dried at 60℃ for 24 h after washing to obtain a polyaryletherbenzimidazole, which is o-PBI; The viscosity average molecular weight of the o-PBI prepared in this example is 8.7 kDa; In S4, 0.625 g of o-PBI obtained in S3 is added to 4.375 g of an organic solvent (dimethylacetamide DMAc), and stirred to dissolve at room temperature for 6 h to obtain an organic solution containing o-PBI; The organic solvent in this example can also be dimethylformamide (DMF); S5, pour the o-PBI-containing organic solution obtained in S4 to the outer side of the hydrophilic PPS woven film obtained in S2, then use a stainless steel scraper to blade-coat the o-PBI-containing organic solution to the surface of the hydrophilic PPS woven film (5 cm x 5 cm), after uniform coverage, obtain the o-PBI-loaded hydrophilic PPS woven film, then put it into deionized water for 24 h, take it out, and vacuum dry at a temperature of 60 DEG C for 24 h, to obtain the o-PBI / PPS alkaline water electrolysis diaphragm; The o-PBI / PPS alkaline water electrolysis diaphragm prepared in the embodiment has a water contact angle of 89.3 DEG, an average pore size of 0.106 mu m, a maximum pore size of 13.951 mu m, a porosity of 12.63%, a bubble point pressure of 3.28 kPa, and a surface resistance of 3.75 omega cm at 80 DEG C 2 .

[0030] The application utilizes the film formation of o-PBI on the surface of the hydrophilic PPS woven film, forms a dense and small pore structure, and the strong hydrophilicity of the substrate hydrophilic PPS woven film, realizes higher air tightness and better electrolytic water performance.

[0031] The o-PBI / PPS alkaline water electrolysis diaphragm prepared by the application is used for an alkaline water electrolysis tank, and is responsible for the diaphragm for blocking gas and permeating alkali solution.

[0032] The above is only a preferred embodiment of the application, and does not limit the application. Any simple modification, change and equivalent change made according to the technical essence of the application to the above embodiment are still within the protection scope of the technical solution of the application.

Claims

1. A method for preparing an o-PBI / PPS alkaline water electrolysis separator, characterized by, The method is as follows: Preparation of S1 and PPS braided films: Polyphenylene sulfide fibers are woven to obtain a PPS woven film; S2. Preparation of hydrophilic PPS woven film: The PPS woven film obtained in S1 was soaked in anhydrous ethanol for 24-30 hours, and then vacuum dried at 60°C to obtain a dried PPS woven film. Then, it was soaked in a nitric acid aqueous solution with a mass fraction of 38%-44% at 50°C for 2-3 hours, rinsed with deionized water until the surface pH value was 7, and then vacuum dried at 80°C to obtain a hydrophilic PPS woven film. Preparation of S3 and o-PBI: Using polyphosphoric acid (PPA) as a solvent, 3,3′,4,4′-tetraaminobiphenyl and 4,4′-diphenyl ether dicarboxylic acid undergo a polycondensation reaction to obtain polyaryl ether benzimidazole, which is o-PBI; S4. Add the o-PBI obtained in S3 to an organic solvent, stir and dissolve at room temperature to obtain an organic solution containing o-PBI. S5. Pour the organic solution containing o-PBI obtained in S4 onto the outside of the hydrophilic PPS woven membrane obtained in S2, and then scrape the organic solution containing o-PBI onto the surface of the hydrophilic PPS woven membrane. After uniform coverage, a hydrophilic PPS woven membrane loaded with o-PBI is obtained. Then, it is immersed in deionized water for 24h to 26h, taken out, and vacuum dried to obtain an o-PBI / PPS alkaline water electrolysis membrane.

2. The method of claim 1, wherein the o-PBI / PPS alkaline water electrolysis separator is prepared by the steps of: The vacuum drying time for S2 at 60℃ is 24h; the vacuum drying time for S2 at 80℃ is 24h.

3. The method of claim 1, wherein the o-PBI / PPS alkaline water electrolysis separator is prepared by the steps of: The ratio of 3,3′,4,4′-tetraaminobiphenyl, 4,4′-diphenyl ether dicarboxylic acid and polyphosphoric acid in S3 is 4.2854:5.1646:

200.

4. The method of claim 3, wherein the o-PBI / PPS alkaline water electrolysis separator is prepared by the steps of: The specific preparation method of the o-PBI is as follows: Polyphosphoric acid was preheated at 60°C for 0.5 h, then heated to 120°C under a nitrogen atmosphere and stirred at a constant temperature of 120 r / min for 0.5 h. 3,3′,4,4′-tetraaminobiphenyl was then added, and the mixture was stirred at a constant temperature of 300 r / min for 3 h. 4,4′-diphenyl ether dicarboxylic acid was then added, and the mixture was stirred at a constant temperature of 300 r / min for 2 h. Finally, the temperature was increased to 140°C at a rate of 1°C / min. The mixture was stirred at 300 r / min for 3.5 h at a constant temperature, then heated to 170 °C at a rate of 1 °C / min and stirred at 300 r / min for 3 h at a constant temperature, then heated to 200 °C at a rate of 1 °C / min and reacted at a constant temperature for 4 h. The product was then washed sequentially with deionized water, sodium carbonate aqueous solution, deionized water, and anhydrous ethanol. The washed product was then vacuum dried to obtain polyaryl ether benzimidazole, i.e., o-PBI.

5. The method for preparing an o-PBI / PPS alkaline water electrolysis membrane according to claim 4, characterized in that, The method for washing the sodium carbonate aqueous solution is washing with 5% sodium carbonate aqueous solution at room temperature for 24 hours; the vacuum drying condition is 60℃ for 24 hours.

6. The method of claim 1, wherein the o-PBI / PPS alkaline water electrolysis separator is prepared by the steps of: The organic solvent in S4 is N-methylpyrrolidone, dimethylacetamide, dimethylformamide or dimethyl sulfoxide.

7. The method for preparing an o-PBI / PPS alkaline water electrolysis membrane according to claim 1, characterized in that, The mass ratio of the o-PBI to the organic solvent in S4 is (0.25-0.625):(4.375-4.75); the stirring and dissolving time in S4 is 6 hours.

8. The method for preparing an o-PBI / PPS alkaline water electrolysis membrane according to claim 1, characterized in that, The vacuum drying condition in S5 is 60℃ for 24 hours.

9. The method for preparing an o-PBI / PPS alkaline water electrolysis membrane according to claim 1, characterized in that, The water contact angle of the o-PBI / PPS alkaline water electrolysis diaphragm in S5 is 68.9°-89.3°, the average pore size is 0.106 μm-16 μm, the bubble point pressure is 0.4 kPa-3.28 kPa, and the surface resistance at 80°C is 0.71 Ω·cm 2 ~ 3.75 Ω·cm 2 .

10. Use of an o-PBI / PPS alkaline water electrolysis separator membrane prepared according to the method of any one of claims 1 to 9, characterized in that, The o-PBI / PPS alkaline water electrolysis diaphragm is used for alkaline water electrolysis tank.