Alkaline electrolyzer separator and method of making same

Abstract

The application provides a kind of alkaline electrolytic cell diaphragm, the method comprises: (1) organic fiber yarn is placed in modification solution and is modified to obtain modified organic fiber yarn;(2) respectively inorganic fiber yarn and the modified organic fiber yarn are fed into air nozzle, air deformation is carried out under air pressure, and inorganic fiber deformation yarn and modified organic fiber deformation yarn are obtained;(3) the inorganic fiber deformation yarn and modified organic fiber deformation yarn are sequentially plaited, twisted, warped, drawn, inserted into reed and woven, and the alkaline electrolytic cell diaphragm is obtained.The alkaline electrolytic cell diaphragm in the application can make the electrolyte fully enter the pores of the alkaline electrolytic cell diaphragm during electrolysis, and can avoid the penetration of oxygen and hydrogen, thereby ensuring better electrolysis effect at lower energy consumption.

Description

Technical Field

[0001] This invention relates to the field of alkaline water electrolysis technology, and in particular to an alkaline electrolyzer diaphragm and its preparation method. Background Technology

[0002] The membrane material for alkaline water electrolysis hydrogen production is an important component of the alkaline electrolyzer, which needs to achieve selective transport of cations and anions. In the process of alkaline water electrolysis hydrogen production, oxygen ions and hydrogen ions are generated at the anode, while hydrogen ions and hydrogen ions are generated at the cathode. The alkaline water electrolyzer is mainly composed of electrodes and a membrane. The electrolyzer is divided into an anode chamber and a cathode chamber, which are separated by a membrane. During the electrolysis process, oxygen is generated at the anode and hydrogen is generated at the cathode. The membrane suitable for alkaline water electrolyzer should meet the following requirements: (1) Ensure that H2 and O2 molecules cannot pass through the membrane, but allow electrolyte ions to pass through; (2) Be able to withstand the corrosion of high concentration alkaline solution; (3) Have good mechanical strength and be able to withstand the impact of electrolyte and generated gas for a long time without damage to the membrane structure; (4) In order to reduce power loss, the membrane must have a small sheet resistance, so the membrane porosity should be as high as possible; (5) The membrane can maintain chemical stability under the electrolysis temperature and pH conditions.

[0003] Currently, polyphenylene sulfide (PPS) is widely used in alkaline electrolytic cell diaphragms due to its excellent heat resistance, good mechanical properties, corrosion resistance, and excellent electrical properties. However, during electrolysis, the electrolyte cannot fully penetrate the pores of the electrolytic cell diaphragm, and tiny bubbles tend to accumulate on the diaphragm surface, thereby increasing the resistance of the electrolytic cell diaphragm and leading to increased energy consumption.

[0004] Therefore, based on the above problems, there is an urgent need to provide a new alkaline electrolytic cell diaphragm and its preparation method. Summary of the Invention

[0005] This invention provides an alkaline electrolytic cell diaphragm and its preparation method. During electrolysis, the electrolyte can fully enter the diaphragm, thereby ensuring a good electrolysis effect with low energy consumption.

[0006] In a first aspect, the present invention provides a method for preparing an alkaline electrolytic cell diaphragm, the method comprising:

[0007] (1) The organic fiber yarn is placed in a modification solution for modification treatment to obtain modified organic fiber yarn;

[0008] (2) The inorganic fiber yarn and the modified organic fiber yarn are fed into the air nozzle respectively, and air deformation is carried out under air pressure to obtain inorganic fiber textured yarn and modified organic fiber textured yarn.

[0009] (3) The inorganic fiber textured yarn and the modified organic fiber textured yarn are sequentially plyed, twisted, warped, threaded, inserted into the heddle, and woven to obtain the alkaline electrolytic cell diaphragm.

[0010] Preferably, the organic fiber yarn is polyethylene fiber yarn, polypropylene fiber yarn, polyphenylene sulfide fiber yarn, polytetrafluoroethylene fiber yarn, or polyetheretherketone fiber yarn; the inorganic fiber yarn is alkali-resistant glass fiber yarn, basalt fiber yarn, or zirconium oxide fiber yarn.

[0011] Preferably, the diameter of the fibers in the organic fiber yarn is 0.5–30 μm and the denier is 0.5–10.0 dtex; the diameter of the fibers in the inorganic fiber yarn is 2–17 μm and the denier is 48–500 tex.

[0012] Preferably, in step (1), the modified solution is a sodium naphthalene solution, chlorosulfonic acid, or concentrated sulfuric acid; the temperature of the modification treatment is 40–150°C, and the time is 5–60 min.

[0013] Preferably, step (2) includes the following sub-steps:

[0014] (21) The fiber yarn is fed into the air nozzle using a roller roller, and the air pressure in the air nozzle is adjusted so that the fiber yarn is intertwined and deformed.

[0015] (22) After the intertwined and deformed fiber yarn leaves the air nozzle, it is bent at 90° to obtain inorganic fiber deformed yarn or modified organic fiber deformed yarn.

[0016] Preferably, in step (21), the air nozzle includes a wire inlet, a wire outlet, and a wire channel. An air inlet hole is provided on the side wall of the air nozzle, and the air inlet hole is used to adjust the gas pressure of the air nozzle.

[0017] Preferably, the ratio of the diameter of the inlet to the diameter of the outlet is (0.4 to 0.7):1, and the angle between the axis of the air inlet and the axis of the air nozzle is 20-40°.

[0018] Preferably, during the air deformation process, the overfeed rate of the fiber yarn is 10-130%, the air pressure is 0.4-0.8 MPa, and the speed at which the fiber yarn is fed into the air nozzle is 100-300 m / min.

[0019] Preferably, in step (3), the mass ratio of the inorganic fiber textured yarn to the modified organic fiber textured yarn is (0.3-0.9):(0.7-0.1).

[0020] Preferably, the twist of the inorganic fiber textured yarn and the modified organic fiber textured yarn after plying is 5 to 50 twists;

[0021] The tension during the weaving process is 10–50 cN, and the relative humidity is 40–80%.

[0022] Secondly, the present invention provides an alkaline electrolytic cell diaphragm, which is obtained by modification using any one of the modification methods described in the first aspect above.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] In this invention, organic fiber yarns are first modified using a modified solution to increase their water absorption rate. Then, the modified organic and inorganic fiber yarns are fed into an air nozzle, causing them to intertwine under the influence of the airflow, forming textured yarns with arc-shaped surfaces. Finally, the inorganic and modified organic textured yarns are woven together to obtain an alkaline electrolytic cell diaphragm with small pores. This allows the electrolyte to fully enter the pores of the diaphragm during electrolysis, while preventing the permeation of oxygen and hydrogen, thus ensuring good electrolysis results with low energy consumption. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a flowchart of an alkaline electrolytic cell diaphragm provided by the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] like Figure 1 As shown, the present invention provides an alkaline electrolytic cell diaphragm, the method comprising:

[0029] (1) The organic fiber yarn is placed in a modification solution for modification treatment to obtain modified organic fiber yarn;

[0030] (2) The inorganic fiber yarn and the modified organic fiber yarn are fed into the air nozzle respectively, and air deformation is carried out under air pressure to obtain inorganic fiber textured yarn and modified organic fiber textured yarn.

[0031] (3) The inorganic fiber textured yarn and the modified organic fiber textured yarn are sequentially plyed, twisted, warped, threaded, inserted into the heddle, and woven to obtain the alkaline electrolytic cell diaphragm.

[0032] In this embodiment of the invention, the organic fiber yarn is first modified with a modified solution to increase its water absorption rate. Then, the modified organic and inorganic fiber yarns are fed into an air nozzle, causing them to intertwine under the influence of the airflow, forming textured yarns with arc-shaped surfaces. Finally, the inorganic and modified organic fiber textured yarns are woven together to obtain an alkaline electrolytic cell diaphragm with small pores. This allows the electrolyte to fully enter the pores of the diaphragm during electrolysis, while preventing the permeation of oxygen and hydrogen, thus ensuring a good electrolysis effect with low energy consumption.

[0033] According to some preferred embodiments, the organic fiber yarn is polyethylene fiber yarn, polypropylene fiber yarn, polyphenylene sulfide fiber yarn, polytetrafluoroethylene fiber yarn, or polyetheretherketone fiber yarn; the inorganic fiber yarn is alkali-resistant glass fiber yarn, basalt fiber yarn, or zirconium oxide fiber yarn.

[0034] According to some preferred embodiments, the organic fiber yarn has a fiber diameter of 0.5–30 μm (e.g., 0.5 μm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, or 30 μm) and a fiber denier of 0.5–10.0 dtex (e.g., 0.5 dtex, 1 dtex, 2 dtex, 5 dtex, 8 dtex, or 10 dtex); the inorganic fiber yarn has a fiber diameter of 2–17 μm (e.g., 2 μm, 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, or 17 μm) and a fiber denier of 48–500 tex (e.g., 48 tex, 50 tex, 80 tex, 100 tex, 200 tex, 300 tex, 400 tex, or 500 tex).

[0035] In this embodiment of the invention, considering the excellent chemical resistance of organic fibers and the advantages of good mechanical properties, small deformation, high operating temperature, and excellent chemical stability of inorganic fibers, the invention employs the aforementioned types of organic and inorganic fibers. Taking into account the differences in properties between organic and inorganic fibers, the invention first processes the aforementioned types and specific diameters of organic fibers sequentially through opening and cleaning, carding, drawing, and roving. The roving is then drafted to obtain fiber single yarns with a count of 5-60s and a twist of 5-100. These yarns are then processed through winding, drawing, twisting, and heat setting to prepare organic fiber yarns with a ply count of 2-8. Finally, the organic and inorganic fiber yarns obtained are mixed and woven together. Furthermore, by synergistically controlling the process parameters during weaving, the integrity of the properties of both organic and inorganic fibers can be ensured, thereby guaranteeing that the alkaline electrolytic cell diaphragm formed by the weaving has good chemical resistance and mechanical properties.

[0036] According to some preferred embodiments, in step (1), the modified solution is sodium naphthalene solution, chlorosulfonic acid or concentrated sulfuric acid; the temperature of the modification treatment is 40 to 150°C (for example, it can be 40°C, 50°C, 80°C, 100°C, 120°C or 150°C), and the time is 5 to 60 min (for example, it can be 5 min, 10 min, 20 min, 30 min, 40 min, 50 min or 60 min).

[0037] Considering that organic fibers are non-polar polymers with extremely low wettability, therefore in OH... - They play almost no role in the movement of ions; however, the OH groups on inorganic fibers and the inorganic particles attached to their surfaces play a significant role. - Bonds play a crucial role in driving hydrogen ion exchange. Therefore, in this embodiment of the invention, by completely immersing the organic fiber yarn in the aforementioned specific type of modification solution and treating it under specific temperature conditions, it is possible to ensure that the hydrophilic groups in the modification solution fully combine with the groups on the surface of the organic fiber yarn. This not only greatly accelerates the water absorption rate of the organic fiber yarn but also improves the purity of hydrogen and oxygen. Compared to methods that modify the hydrophilicity of organic fibers after spinning, the method of modifying the fibers before spinning in this embodiment has significant advantages. It optimizes the process directly during fiber manufacturing, thus ensuring that the fibers can more effectively exert their water absorption and gas purity enhancement properties in subsequent applications.

[0038] It should be noted that, in the embodiments of the present invention, when the modified solution is sodium naphthalene solution, the mass concentration of the solution is preferably 0.1-1 mol / L, and the modified solution is preferably chlorosulfonic acid or concentrated sulfuric acid with a mass concentration of 85-98%.

[0039] According to some preferred embodiments, step (2) includes the following sub-steps:

[0040] (21) The fiber yarn is fed into the air nozzle using a roller roller, and the air pressure in the air nozzle is adjusted so that the fiber yarn is intertwined and deformed.

[0041] (22) After the intertwined and deformed fiber yarn leaves the air nozzle, it is bent at 90° to obtain inorganic fiber deformed yarn or modified organic fiber deformed yarn.

[0042] In this embodiment of the invention, before weaving the modified organic fiber yarn and inorganic fiber yarn together, the modified organic fiber yarn (or inorganic fiber yarn) is passed through an air nozzle at the same speed via rollers. Passing through the turbulent airflow field within the air nozzle, the individual fibers in the fiber yarn are blown apart and separated under the action of the airflow. The separated individual fibers intertwine with each other, and simultaneously undergo lateral bending deformation, thereby producing looped or arc-shaped structures. Finally, the deformed fiber yarn is bent at 90° by a refractive element at the air nozzle outlet and continuously pulled out. The modified organic fiber textured yarn with a stable loop structure is formed by the interaction of friction between the rollers or between individual fiber yarns. The modified organic fiber yarn and the inorganic fiber yarn are fed into the air nozzle for air deformation using the above method. This allows the filaments of the fiber yarn to intertwine and loop in the airflow of the air nozzle, thereby forming a loosely structured fiber textured yarn. This ensures that the final alkaline electrolytic cell diaphragm has good porosity and reduces the concentration of hydrogen in oxygen, thus avoiding explosion problems caused by excessive hydrogen and oxygen concentrations.

[0043] According to some preferred embodiments, in step (21), the air nozzle includes an inlet, an outlet, and a yarn path. An air inlet hole is provided on the side wall of the air nozzle, which is used to adjust the gas pressure of the air nozzle. The ratio of the diameter of the inlet to the diameter of the outlet is (0.4 to 0.7):1 (for example, it can be 0.4:1, 0.5:1, 0.6:1, or 0.7:1). The angle between the axis of the air inlet hole and the core axis of the air nozzle is 20-40° (for example, it can be 20°, 30°, or 40°).

[0044] According to some preferred embodiments, during the air deformation process, the overfeed rate of the fiber yarn is 10-130% (e.g., 10%, 20%, 40%, 80%, 110%, or 130%), the air pressure is 0.4-0.8 MPa (e.g., 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, or 0.8 MPa), and the speed at which the fiber yarn is fed into the air nozzle is 100-300 m / min (e.g., 100 m / min, 150 m / min, 200 m / min, 250 m / min, or 300 m / min).

[0045] Based on the properties of the modified organic fiber yarn and the inorganic fiber, in this embodiment of the invention, considering that during air processing, the diameter ratio of the inlet and outlet of the air nozzle directly affects the smoothness of yarn entry and exit and the pushing effect of airflow on the yarn, while the angle between the axis of the air inlet and the core axis is related to the uniformity and directionality of airflow distribution, which is crucial to ensuring the stability and accuracy of nozzle performance, this embodiment optimizes the flow efficiency and direction of gas by rationally designing the diameter of the inlet / outlet of the air nozzle and the angle of the air inlet; and further optimizes the feeding speed of the fiber yarn and the air pressure during air texturing. Comprehensive control of process parameters such as overfeed rate is beneficial for preparing modified organic and inorganic fiber textured yarns with suitable coil size on the fiber surface, good mechanical properties, and easy weaving. For example, if the overfeed rate of the fiber yarn is too large, the coil size formed on the fiber surface will be too large, which will affect the yarn's passage in the subsequent weaving process and thus have an adverse effect on the subsequent weaving process. If the overfeed rate of the fiber yarn is too small, it will be difficult for the fiber filaments to form an intertwined loop structure during the deformation process, resulting in a poor deformation effect of the fiber yarn and thus failing to ensure that the final alkaline electrolytic cell diaphragm has a good porosity.

[0046] According to some preferred embodiments, in step (3), the mass ratio of the inorganic fiber textured yarn to the modified organic fiber textured yarn is (0.1-0.9):(0.9-0.1) (for example, it can be 0.1:0.9, 0.1:0.1, 0.1:0.5, 0.1:0.8, 0.5:0.1, 0.5:0.8, 0.8:0.1, 0.8:0.5, or 0.9:0.1).

[0047] In this embodiment of the invention, by considering the respective advantages of inorganic and organic fibers, inorganic and organic fibers are creatively combined to give full play to the advantages of both fibers. At the same time, the disadvantages of inorganic and organic fibers, the performance changes of modified and deformed fiber yarns, and the process differences brought about by using them together in the textile process are comprehensively considered. Thus, the mass ratio of inorganic fiber textured yarn to modified organic fiber textured yarn is controlled within the above-mentioned range. This is beneficial to obtaining alkaline electrolytic cell diaphragms with good ion conductivity, high gas barrier properties, and low energy consumption through textiles.

[0048] According to some preferred embodiments, in step (3), the twist of the inorganic fiber textured yarn and the modified organic fiber textured yarn after plying is 5 to 50 twists (for example, it can be 5 twists, 10 twists, 20 twists, 30 twists, 40 twists or 50 twists); the tension during the weaving process is 10 to 50 cN (for example, it can be 10 cN, 20 cN, 30 cN, 40 cN or 50 cN); and the relative humidity is 40 to 80% (for example, it can be 40%, 50%, 60%, 70% or 80%).

[0049] In this embodiment of the invention, to ensure that the air permeability of the final membrane fabric is within a suitable range and to avoid excessive air permeability, it is first necessary to control the blending ratio of inorganic fiber textured yarn and modified organic fiber textured yarn to balance air permeability and other properties. Furthermore, the fineness and twist of the fiber textured yarn are adjusted to ensure the density and air permeability of the fiber fabric. During the weaving process, the tension and relative humidity are controlled to prevent the inorganic fiber yarn from breaking easily and to balance the process parameter changes caused by the large difference in breaking elongation between the inorganic fiber textured yarn and the modified organic fiber textured yarn. Then, by changing the warp and weft density and tightness of the fabric, good air permeability of the fiber fabric can be ensured. Furthermore, a suitable weaving speed is used to avoid fiber breakage or uneven fabric structure caused by excessively fast or slow weaving, thus facilitating the preparation of an alkaline electrolytic cell membrane with suitable pore size and air permeability.

[0050] It should be noted that, in this embodiment of the invention, the warp density of the fabric is 35-75 threads / 5cm, the weft density is 40-80 threads / 5cm, the weaving speed is 350-500 r / min, and the tightness is 1.5-3.5 g / cm. 3 .

[0051] It should be noted that the structure of the fabric formed in the embodiments of the present invention can be plain weave, twill weave, satin weave, mesh structure, velvet structure, or a combined structure or a more complex structure. A combined structure is a new structure formed by combining two or more original or modified structures using different methods, possessing a special appearance effect, such as striped or checkered structures, or openwork structures. A complex structure refers to at least one of the warp and weft yarns consisting of two or more sets of yarn systems, such as a double structure or a double-layer structure. In the embodiments of the present invention, a mesh structure or velvet structure is preferred, thus ensuring that the formed fabric alkaline electrolytic cell diaphragm has good air permeability. Furthermore, the forming method of the above-mentioned structure is not specifically limited in the embodiments of the present invention; those skilled in the art can adjust the parameters during the weaving process according to the structure of the structure.

[0052] The present invention also provides an alkaline electrolytic cell diaphragm prepared by any of the above-described preparation methods; the preparation method in the embodiments of the present invention can yield a diaphragm with a thickness of 0.1-3 mm and an areal density of 100-1000 g / m³. 2 A composite fiber woven fabric with a pore size of 0.1-10μm, an average pore size of less than 6μm, a porosity of 40-70%, and an air permeability of 0.3-5cm / s can be directly used as a diaphragm for alkaline water electrolysis to produce hydrogen.

[0053] In summary, the alkaline electrolyzer membrane in this embodiment of the invention exhibits high ion conductivity and good gas barrier properties during electrolysis, allowing the electrolyte to fully enter the pores of the membrane and effectively preventing the aggregation of microbubbles on the membrane surface. This results in better electrolysis performance with lower energy consumption. Furthermore, the alkaline electrolyzer membrane in this embodiment can be appropriately used as an electrolysis membrane for water using alkaline aqueous solutions as the electrolyte. In addition, it can also be used as a membrane for alkaline fuel cells, primary and secondary batteries, and for salt electrolysis.

[0054] To more clearly illustrate the technical solution and advantages of the present invention, a detailed description of an alkaline electrolytic cell diaphragm is provided below through several embodiments.

[0055] Example 1:

[0056] (1) Organic short fibers (polyphenylene sulfide) with a diameter of 15μm, a denier of 2dtex and a flat cross-section are processed through opening and cleaning, carding, drawing and roving. The roving is then stretched to obtain an organic fiber single yarn with a count of 5s and a twist of 100. The yarn is then wound, drawn, twisted and heat-set to obtain a polytetrafluoroethylene organic fiber yarn with 10 plies. The polyphenylene sulfide organic fiber yarn is placed in a modification solution (a sodium naphthalene solution with a concentration of 0.2mol / L) and modified at 40℃ for 10min to obtain modified organic fiber yarn (polyphenylene sulfide yarn).

[0057] (2) Using rollers, inorganic fiber yarn (zirconia fiber with a diameter of 6μm and a denier of 128tex) and modified organic fiber yarn are fed into an air nozzle (with an inlet diameter of 0.4cm and an outlet diameter of 1cm, and an angle of 20° between the axis of the air inlet and the core axis of the air nozzle) at a speed of 200m / min and an overfeed rate of 10%. The air pressure in the air nozzle is adjusted to 0.7MPa to make the fiber yarn intertwine and deform. After the intertwined and deformed fiber yarn leaves the air nozzle, it is bent at 90° to obtain inorganic fiber textured yarn and modified organic fiber textured yarn respectively.

[0058] (3) Inorganic fiber textured yarn and modified organic fiber textured yarn with a mass ratio of 8:2 were sequentially plyed, twisted, warped, threaded onto heddles, inserted into reeds, and woven. During the weaving process, the weaving speed was 400 r / min, the tension was 30 cN, and the relative humidity was 60%. The resulting warp density was 45 ends / 5cm, the weft density was 40 ends / 5cm, and the tightness was 3 g / cm. 3 Alkaline electrolytic cell diaphragm made of plain woven fabric with a twist of 200.

[0059] Example 2:

[0060] (1) Organic short fibers (polytetrafluoroethylene) with a diameter of 30μm, a denier of 10dtex and a flat cross-section are processed through opening and cleaning, carding, drawing and roving. The roving is then stretched to obtain an organic fiber single yarn with a count of 5s and a twist of 100. The yarn is then wound, drawn, twisted and heat-set to obtain a polytetrafluoroethylene organic fiber yarn with 10 plies. The polytetrafluoroethylene organic fiber yarn is placed in a modification solution (a sodium naphthalene solution with a concentration of 0.2mol / L) and modified at 40℃ for 10min to obtain modified organic fiber yarn (polytetrafluoroethylene yarn).

[0061] (2) Using rollers, inorganic fiber yarn (zirconia fiber with a diameter of 13μm and a denier of 128tex) and modified organic fiber yarn are fed into an air nozzle (with an inlet diameter of 0.7cm and an outlet diameter of 1cm, and an angle of 20° between the axis of the air inlet and the core axis of the air nozzle) at a speed of 200m / min and an overfeed rate of 40%. The air pressure in the air nozzle is adjusted to 0.7MPa to make the fiber yarn intertwine and deform. After the intertwined and deformed fiber yarn leaves the air nozzle, it is bent at 90° to obtain inorganic fiber textured yarn and modified organic fiber textured yarn respectively.

[0062] (3) Inorganic fiber textured yarn and modified organic fiber textured yarn with a mass ratio of 8:2 were sequentially plyed, twisted, warped, threaded onto heddles, inserted into reeds, and woven. During the weaving process, the weaving speed was 400 r / min, the tension was 30 cN, and the relative humidity was 60%. The resulting warp density was 45 ends / 5cm, the weft density was 40 ends / 5cm, and the tightness was 3 g / cm. 3 Alkaline electrolytic cell diaphragm made of plain woven fabric with a twist of 200.

[0063] Example 3:

[0064] (1) Organic short fibers (polypropylene fibers) with a diameter of 20μm, a denier of 8dtex and a circular cross-section are processed through opening and cleaning, carding, drawing and roving. The roving is then drawn to obtain an organic fiber single yarn with a count of 5s and a twist of 100. The yarn is then wound, drawn, twisted and heat-set to obtain a polypropylene organic fiber yarn with 50 plies. The polypropylene organic fiber yarn is placed in a modification solution (chlorosulfonic acid with a mass concentration of 98%) and modified at 60℃ for 30 min to obtain modified organic fiber yarn (polypropylene yarn).

[0065] (2) Using rollers, inorganic fiber yarn (basalt fiber with a diameter of 17μm and a denier of 500tex) and modified organic fiber yarn are fed into an air nozzle (with an inlet diameter of 0.6cm and an outlet diameter of 1cm, and an angle of 40° between the axis of the air inlet and the core axis of the air nozzle) at a speed of 100m / min and an overfeed rate of 60%. The air pressure in the air nozzle is adjusted to 0.8MPa to make the fiber yarn intertwine and deform. After the intertwined and deformed fiber yarn leaves the air nozzle, it is bent at 90° to obtain inorganic fiber textured yarn and modified organic fiber textured yarn respectively.

[0066] (3) Inorganic fiber textured yarn and modified organic fiber textured yarn with a mass ratio of 7:3 were sequentially plyed, twisted, warped, threaded onto heddles, inserted into reeds, and woven. During the weaving process, the weaving speed was 500 r / min, the tension was 10 cN, and the relative humidity was 40%. The resulting warp density was 35 ends / 5cm, the weft density was 32 ends / 5cm, and the tightness was 2.5 g / cm. 3 Alkaline electrolytic cell diaphragm made of plain woven fabric with a twist of 150.

[0067] Example 4:

[0068] (1) Organic short fibers (polyetheretherketone fibers) with a diameter of 9μm, a denier of 6dtex and an elliptical cross section are processed through opening and cleaning, carding, drawing and roving. The roving is then stretched to obtain an organic fiber single yarn with a count of 5s and a twist of 100. The yarn is then wound, drawn, twisted and heat-set to obtain a polyetheretherketone fiber organic fiber yarn with 10 plies. The polyetheretherketone fiber organic fiber yarn is placed in a modification solution (concentrated sulfuric acid with a mass concentration of 98%) and modified at 150℃ for 5 min to obtain modified organic fiber yarn (polyetheretherketone fiber yarn).

[0069] (2) Using rollers, inorganic fiber yarn (alkali-resistant glass fiber with a diameter of 7μm and a denier of 56tex) and modified organic fiber yarn are fed into an air nozzle (with an inlet diameter of 0.5cm and an outlet diameter of 1cm, and the angle between the axis of the air inlet and the core axis of the air nozzle is 30°) at a speed of 200m / min and an overfeed rate of 10%. The air pressure in the air nozzle is adjusted to 0.5MPa to make the fiber yarn intertwine and deform. After the intertwined and deformed fiber yarn leaves the air nozzle, it is bent at 90° to obtain inorganic fiber textured yarn and modified organic fiber textured yarn respectively.

[0070] (3) The inorganic fiber textured yarn and the modified organic fiber textured yarn with a mass ratio of 6:4 are sequentially plyed, twisted, warped, threaded onto heddles, inserted into reeds, and woven. During the weaving process, the weaving speed is 350 r / min, the tension is 20 cN, the relative humidity is 50%, and the density is 1.5 g / cm. 3 The alkaline electrolytic cell diaphragm is woven from a twill double-weft woven fabric with a warp density of 60 threads / 5cm, a weft density of 55 threads / 5cm, and a twist of 5.

[0071] Example 5:

[0072] (1) Organic short fibers (polyethylene fibers) with a diameter of 6μm, a denier of 0.8dtex and an elliptical cross section are processed through opening and cleaning, carding, drawing and roving. The roving is then stretched to obtain an organic fiber single yarn with a count of 5s and a twist of 100. The yarn is then wound, drawn, twisted and heat-set to obtain a polyethylene organic fiber yarn with 2 plies. The polyethylene organic fiber yarn is placed in a modification solution (concentrated sulfuric acid with a mass concentration of 98%) and modified at 150℃ for 5 min to obtain modified organic fiber yarn (polyethylene yarn).

[0073] (2) Using rollers, inorganic fiber yarn (alkali-resistant glass fiber with a diameter of 6μm and a denier of 68tex) and modified organic fiber yarn are fed into an air nozzle (with an inlet diameter of 0.3cm and an outlet diameter of 0.5cm, and an angle of 30° between the axis of the air inlet and the core axis of the air nozzle) at a speed of 200m / min and an overfeed rate of 50%. The air pressure in the air nozzle is adjusted to 0.5MPa to make the fiber yarn intertwine and deform. After the intertwined and deformed fiber yarn leaves the air nozzle, it is bent at 90° to obtain inorganic fiber textured yarn and modified organic fiber textured yarn, respectively.

[0074] (3) The inorganic fiber textured yarn and the modified organic fiber textured yarn with a mass ratio of 7:3 were successively plyed, twisted, warped, threaded onto heddles, inserted into reeds, and woven. During the weaving process, the weaving speed was 400 r / min, the tension was 50 cN, and the relative humidity was 80%. The resulting warp density was 65 threads / 5cm, the weft density was 45 threads / 5cm, and the tightness was 2 g / cm. 3 Alkaline electrolytic cell diaphragm made of plain woven fabric with a twist of 20.

[0075] Example 6:

[0076] Example 6 is basically the same as Example 1, except that in step (2), the overfeed rate of the fiber yarn is 135%.

[0077] Example 7:

[0078] Example 7 is basically the same as Example 1, except that in step (2), the air pressure is 1 MPa and the speed at which the fiber yarn is fed into the air nozzle is 80 m / min.

[0079] Example 8:

[0080] Example 8 is basically the same as Example 1, except that in step (2), the air pressure is 0.3 MPa and the speed at which the fiber yarn is fed into the air nozzle is 400 m / min.

[0081] Example 9:

[0082] Example 9 is basically the same as Example 1, except that in step (3), the tension during the weaving process is 60 cN and the relative humidity is 90%.

[0083] Example 10:

[0084] Example 10 is basically the same as Example 1, except that in step (3), the tension during the weaving process is 5 cN and the relative humidity is 30%.

[0085] Comparative Example 1:

[0086] (1) Organic short fibers (polyphenylene sulfide fibers) with a diameter of 6μm, a denier of 2.2dtex and an elliptical cross section are processed through opening and cleaning, carding, drawing and roving. The roving is then stretched to obtain an organic fiber single yarn with a count of 5s and a twist of 100. The yarn is then wound, drawn, twisted and heat-set to obtain a polyphenylene sulfide organic fiber yarn with 2 plies.

[0087] (2) The obtained organic fiber yarn (polyphenylene sulfide yarn) is used as the warp and weft yarns and woven on a loom to produce a plain weave fabric with a warp density of 47 threads / inch and a weft density of 55 threads / inch.

[0088] (3) The above plain weave woven fabric was modified in a sodium naphthalene solution with a concentration of 0.2 mol / L at 40°C for 10 min and then dried to serve as a diaphragm for an alkaline electrolytic cell.

[0089] Comparative Example 2:

[0090] Comparative Example 2 is basically the same as Example 1, except that in step (1), the organic fiber yarn was not modified.

[0091] Comparative Example 3:

[0092] Comparative Example 3 is basically the same as Example 1, except that step (2) is removed. That is, the modified organic fiber yarn (polyphenylene sulfide yarn) and inorganic fiber yarn (alkali-resistant glass fiber with a diameter of 6μm and a denier of 110tex) with a mass ratio of 1:1 are directly plyed, twisted, warped, threaded, inserted, and woven in sequence to obtain a plain weave woven alkaline electrolytic cell diaphragm with a warp density of 45 threads / 5cm, a weft density of 40 threads / 5cm, and a twist of 20.

[0093] Comparative Example 4:

[0094] Comparative Example 4 is basically the same as Example 1, except that in step (3), only the modified organic fiber textured yarn is used as the warp and weft yarn, and the yarn is plied, twisted, warped, threaded, inserted and woven in sequence to obtain a plain weave fabric alkaline electrolytic cell diaphragm with a warp density of 45 threads / 5cm, a weft density of 40 threads / 5cm, and a twist of 20.

[0095] The modified alkaline electrolyzer diaphragms from Examples 1 to 10 and Comparative Examples 1 to 4 were subjected to performance tests, and the test data are shown in Table 1.

[0096] Performance testing methods or standards:

[0097] Air permeability: Tested according to GB / T5453 standard, pressure drop 200Pa, test area 50mm2;

[0098] Porosity determination method: The porosity of each membrane described above was measured by the n-butanol immersion method. Each membrane was cut into a circular piece with a diameter of approximately 2 cm, and its thickness and mass were measured. The membrane was then immersed in n-butanol for 2 hours. After 2 hours, the membrane was removed, and the residual n-butanol on the surface of the membrane was gently wiped off with filter paper and weighed. The membrane porosity was calculated using the following formula:

[0099]

[0100] Where P(%) is the porosity of the membrane, and W 前 and W 后 These represent the mass of the diaphragm before and after immersion in n-butanol, respectively, where ρ is the density of n-butanol (0.811 g / cm³). 3 V represents the volume of the diaphragm.

[0101] Aperture size: Tested according to ASTM F3126 standard method.

[0102] Water absorption rate: Tested according to the dripping method in 7.1.1 of JIS L1907-2010 Test Method for Water Absorption of Fiber Products.

[0103] Table 1

[0104]

[0105]

[0106] As shown in Table 1, the preparation method in the embodiments of the present invention can prepare composite fiber fabrics with suitable thickness, areal density, pore size, porosity and air permeability. When directly used as a diaphragm for alkaline water electrolysis to produce hydrogen, the diaphragm has high ion conductivity and good gas barrier properties. At the same time, the diaphragm achieves good electrolysis effect with low energy consumption.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an alkaline electrolytic cell diaphragm, characterized in that, The method includes: (1) The organic fiber yarn is placed in a modification solution for modification treatment to obtain modified organic fiber yarn; the modification solution is sodium naphthalene solution, chlorosulfonic acid or concentrated sulfuric acid; the temperature of the modification treatment is 40~150°C and the time is 5~60min; (2) The inorganic fiber yarn and the modified organic fiber yarn are fed into the air nozzle respectively, and air deformation is carried out under air pressure to obtain inorganic fiber textured yarn and modified organic fiber textured yarn. (21) The fiber yarn is fed into the air nozzle using a roller roller, and the air pressure in the air nozzle is adjusted to make the fiber yarn intertwine and deform; the air nozzle includes an inlet, an outlet and a yarn path, and an air inlet is provided on the side wall of the air nozzle, which is used to adjust the gas pressure of the air nozzle; the ratio of the diameter of the inlet to the diameter of the outlet is (0.4~0.7):1, and the angle between the axis of the air inlet and the core axis of the air nozzle is 20-40°; (22) After the intertwined and deformed fiber yarn leaves the air nozzle, it is bent at 90° to obtain inorganic fiber deformed yarn or modified organic fiber deformed yarn; during the air deformation process, the overfeed rate of the fiber yarn is 10~130%, the air pressure is 0.4~0.8MPa, and the speed at which the fiber yarn is fed into the air nozzle is 100~300m / min. (3) The inorganic fiber textured yarn and the modified organic fiber textured yarn are sequentially plyed, twisted, warped, threaded, inserted into reeds, and woven to obtain the alkaline electrolytic cell diaphragm; the mass ratio of the inorganic fiber textured yarn to the modified organic fiber textured yarn is (6~9):(1~4); the thickness of the alkaline electrolytic cell diaphragm is 0.1-3mm, and the areal density is 100-1000g / m³. 2 The pore size is 0.1-10μm, the average pore size is less than 6μm, the porosity is 40-70%, and the air permeability is 0.3-5cm / s.

2. The preparation method according to claim 1, characterized in that, The organic fiber yarn is polyethylene fiber yarn, polypropylene fiber yarn, polyphenylene sulfide fiber yarn, polytetrafluoroethylene fiber yarn, or polyetheretherketone fiber yarn; the inorganic fiber yarn is alkali-resistant glass fiber yarn, basalt fiber yarn, or zirconium oxide fiber yarn.

3. The preparation method according to claim 1, characterized in that, The organic fiber yarn has a fiber diameter of 0.5~30μm and a fiber denier of 0.5~10.0dtex; the inorganic fiber yarn has a fiber diameter of 2~17μm and a fiber denier of 48~500tex.

4. The preparation method according to claim 1, characterized in that, In step (3), the twist of the inorganic fiber textured yarn and the modified organic fiber textured yarn after plying is 5 to 50 twists; The tension during the weaving process is 10~50cN, and the relative humidity is 40~80%.

5. A diaphragm for an alkaline electrolytic cell, characterized in that, It is prepared by any one of the preparation methods according to claims 1 to 4.

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