A hydroxyl nickel oxide-based alkaline electrolytic water diaphragm, a preparation method and application thereof

Abstract

The application discloses a kind of basic electrolytic water diaphragm based on nickel oxyhydroxide and its preparation method and application, it is related to composite diaphragm technical technical field, the basic electrolytic water diaphragm is prepared using phase inversion method, wherein inorganic nano filler selects nano nickel oxyhydroxide NiOOH particle, the mass percentage of nickel oxyhydroxide in casting solution is 15-30%.Strong chemical bond formed by nickel ion and hydroxyl in the nickel oxyhydroxide crystal used by the application, gives its excellent structural stability, in strong alkaline electrolytic environment, the material shows excellent anti-dissolution, anti-hydrolysis and anti-structural collapse ability, can tolerate high concentration OH ‑ Erosion; at the same time has intrinsic high antioxidant properties.

Description

Technical Field

[0001] This invention relates to the field of composite membrane technology, specifically to an alkaline water electrolysis membrane based on nickel hydroxy oxide, its preparation method, and its application. Background Technology

[0002] Alkaline water electrolysis membrane is one of the core components of an electrolyzer. The membrane separates the cathode and anode chambers, and under the action of KOH electrolyte and electric current, it realizes efficient water molecule cracking to produce hydrogen. It can be widely used in the large-scale production of hydrogen, renewable energy storage, synthetic ammonia feedstock gas production and fuel cell hydrogen refueling stations.

[0003] The mainstream preparation process for alkaline water electrolysis membranes is typically based on the phase inversion method. This usually involves adding zirconium oxide (ZrO2) nanoparticles or their surface-modified products to a casting solution, thoroughly mixing and stirring, and then using a phase inversion process to obtain a composite membrane with a microporous structure. Besides the widely used zirconium oxide filler, other high-performance inorganic nanofillers (such as cerium oxide (CeO2) and titanium dioxide (TiO2)) have also received increasing attention and been introduced into research and application in recent years. These fillers aim to improve the key properties of the membrane, such as hydrophilicity, ionic conductivity, chemical stability, and mechanical strength, to meet the requirements for efficient and durable alkaline water electrolysis for hydrogen production.

[0004] The pore structure plays a decisive role in the performance of the membrane. Its core function is to provide transport channels for anions and cations in the electrolyte, effectively isolating hydrogen and oxygen while reducing internal resistance. Therefore, precise control of pore size and porosity is crucial. If the pore size is too large, the membrane's airtightness decreases; if it is too small, ion transport is hindered. The effect of porosity follows the same rule: too high a porosity may compromise airtightness, while too low a porosity will increase internal resistance. Therefore, the membrane needs to achieve an optimal balance between pore size and porosity through optimized pore structure design to simultaneously meet the core requirements of high airtightness and low internal resistance. However, currently used inorganic nanofillers may not be able to achieve instantaneous micro-dispersion, which can lead to a series of chain problems. For example, agglomerates can easily clog micropores, and local pore defects can cause hydrogen and oxygen to cross-contaminate, significantly increasing the risk of explosion. At the same time, local temperature gradients can induce polysulfone phase separation, forming an asymmetric pore structure and causing surface densification, ultimately resulting in voltage fluctuations in the electrolyzer.

[0005] Therefore, providing an alkaline water electrolysis membrane with low surface resistance and high airtightness that is simple to prepare is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides an alkaline water electrolysis membrane based on nickel hydroxy oxide, its preparation method, and its application. The method of this invention has advantages such as simple operation, low cost, and high yield, and the prepared membrane has the characteristics of low surface resistivity and high airtightness.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An alkaline water electrolysis membrane based on nickel hydroxy oxide is provided. The alkaline water electrolysis membrane is prepared by phase inversion method, wherein the inorganic nanofiller is selected as nano-nickel hydroxy oxide (NiOOH) particles.

[0009] Preferably, the mass percentage of the nano-nickel hydroxyl oxide in the casting solution is 15-30%, and the particle size of the nano-nickel hydroxyl oxide is 200-250 nm.

[0010] Preferably, the casting solution comprises the following raw materials by mass percentage: N-methylpyrrolidone: polysulfone: polyvinylpyrrolidone: NiOOH = 55-65%: 15-20%: 5-10%: 10-20%.

[0011] Preferably, the preparation method of the nano-nickel hydroxyl oxide is as follows:

[0012] Nickel acetate and urea were dissolved in distilled water, and then polyvinylpyrrolidone was added and stirred until homogeneous. The mixture was then reacted at 100°C for 24 hours and cooled to room temperature to obtain the product, which is a matcha-green NiOOH powder.

[0013] Preferably, the mass ratio of the nickel acetate, the urea, the distilled water, and the polyvinylpyrrolidone is 74.7:120.1:100.

[0014] Preferably, the preparation method of the nano-nickel hydroxyl oxide is as follows:

[0015] Dissolve potassium hydroxide and concentrated ammonia in deionized water, then add β-Ni(OH)2 and stir until homogeneous. Then heat to 60℃ and add potassium persulfate in batches to react. The reaction continues until the reaction solution turns black and no oxygen bubbles are produced. The product obtained is black NiOOH powder.

[0016] Preferably, the mass-to-volume ratio of the potassium hydroxide, the concentrated ammonia, the deionized water, and the β-Ni(OH)2 is 7g:8mL:80mL:10g.

[0017] The preparation method of the alkaline water electrolysis membrane based on nickel hydroxyl oxide described above specifically includes the following steps:

[0018] (1) Preparation of casting solution: Polysulfone powder, polyvinyl alcohol and polyvinylpyrrolidone are added to N-methylpyrrolidone in sequence to form a uniform and transparent solution. Then, nano-nickel hydroxyl oxide is added and stirred evenly to obtain the casting solution.

[0019] (2) After the casting solution is degassed, a uniform liquid film is formed on the substrate, and then it is immersed in deionized water for phase transformation to form a wet composite membrane with a microporous structure.

[0020] (3) The wet composite membrane is washed and dried to obtain an alkaline water electrolysis membrane based on nickel hydroxy oxide.

[0021] Preferably, the stirring time in step (1) is 8-24 hours;

[0022] The phase transformation time described in step (2) is 5-30 min;

[0023] The drying conditions described in step (3) are: drying at 50-60℃ for 12-24 hours.

[0024] The above describes the application of an alkaline water electrolysis membrane based on nickel hydroxy oxide in the field of water electrolysis.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) Breakthrough in material stability: The strong chemical bonds formed between nickel ions and hydroxyl groups in the nickel oxide crystal used in this invention endow it with excellent structural stability. In a strongly alkaline electrolytic environment, this material exhibits excellent resistance to dissolution, hydrolysis, and structural collapse, and can withstand high concentrations of OH for a long time. - It resists corrosion; at the same time, it possesses intrinsic high antioxidant properties, capable of withstanding high potential impacts of >1.5V in the anodic region, avoiding electrochemical degradation, and increasing the membrane's service life by >40%;

[0027] (2) Upgraded ion transport efficiency: The NiOOH surface used in this invention is enriched with hydroxyl functional groups, which can construct hydroxide ions (OH-). - The rapid transport channel has a hydroxide ion conductivity that is about twice that of traditional inorganic fillers (such as ZrO2 / CeO2 / TiO2). This characteristic significantly reduces the membrane surface resistance, causing the electrolyzer operating voltage to drop by 8-12%.

[0028] (3) Expanded formulation tolerance: This invention breaks through the bottleneck of material dispersion by strengthening the mixing process, so that the proportion of components in the casting solution can be controlled in a wide range. This feature supports the customized development of diaphragm performance (such as high mechanical strength type / high ion conductivity type).

[0029] (4) Improved overall performance: Through the collaborative innovation of materials and processes, this invention enables the membrane to have an ionic conductivity ≥0.12S / cm (80℃, 30% KOH) and a tensile strength >20MPa (5 times higher than pure PSF membrane). After 1000h accelerated aging at 30% KOH and 80℃, the performance degradation is <5%. Attached Figure Description

[0030] 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. The drawings in this description are merely embodiments of the present invention.

[0031] Figure 1 The image shows the XRD pattern of NiOOH powder in Example 1 of this invention.

[0032] Figure 2 Thermogravimetric analysis diagram of NiOOH powder in Example 1 of this invention;

[0033] Figure 3 This is a scanning electron microscope image of NiOOH powder in Example 1 of the present invention;

[0034] Figure 4 This is a scanning electron microscope image of the surface of the NiOOH / PSF composite microporous membrane in Example 1 of the present invention;

[0035] Figure 5 This is a scanning electron microscope image of the cross-section of the NiOOH / PSF composite microporous membrane in Example 1 of the present invention;

[0036] Figure 6 This is a tensile strength test diagram of the NiOOH / PSF composite microporous membrane in Example 1 of the present invention;

[0037] Figure 7 This is a test diagram of the contact angle of the NiOOH / PSF composite microporous membrane in Example 1 of the present invention;

[0038] Figure 8 This is a test diagram of the surface resistance of the NiOOH / PSF composite microporous membrane in Example 1 of the present invention;

[0039] Figure 9 The image shows the XRD pattern of NiOOH powder in Example 2 of this invention.

[0040] Figure 10 This is a thermogravimetric analysis diagram of NiOOH powder in Example 2 of the present invention;

[0041] Figure 11 This is a scanning electron microscope image of NiOOH powder in Example 2 of the present invention;

[0042] Figure 12 This is a scanning electron microscope image of the surface of the NiOOH / PSF / PVP composite microporous membrane in Example 2 of the present invention;

[0043] Figure 13 This is a scanning electron microscope image of the cross-section of the NiOOH / PSF / PVP composite microporous membrane in Example 2 of the present invention;

[0044] Figure 14 This is a tensile strength test diagram of the NiOOH / PSF / PVP composite microporous membrane in Example 2 of the present invention;

[0045] Figure 15 This is a test diagram of the contact angle of the NiOOH / PSF / PVP composite microporous membrane in Example 2 of the present invention;

[0046] Figure 16 This is a test diagram of the surface resistance of the NiOOH / PSF / PVP composite microporous membrane in Example 2 of the present invention;

[0047] Figure 17 This is a voltage test diagram of the NiOOH / PSF / PVP composite microporous membrane chamber in Example 2 of the present invention;

[0048] Figure 18 This is a tensile strength test diagram of the NiOOH / PSF composite microporous membrane in Example 3 of the present invention;

[0049] Figure 19 This is a test diagram of the contact angle of the NiOOH / PSF composite microporous membrane in Example 3 of the present invention;

[0050] Figure 20 This is a test diagram of the surface resistance of the NiOOH / PSF composite microporous membrane in Example 3 of the present invention;

[0051] Figure 21 This is a tensile strength test diagram of the NiOOH / PSF / PVP composite microporous membrane in Example 4 of the present invention;

[0052] Figure 22 This is a test diagram of the contact angle of the NiOOH / PSF / PVP composite microporous membrane in Example 4 of the present invention;

[0053] Figure 23 The image shows the surface resistance test results of the NiOOH / PSF / PVP composite microporous membrane in Example 4 of this invention. Detailed Implementation

[0054] Embodiments of the present invention are described below, examples of which are shown in the accompanying drawings. The embodiments described with reference to the drawings are exemplary and intended to explain the present invention, but are not to be construed as limiting the present invention.

[0055] Example 1

[0056] This invention provides a method for preparing an alkaline water electrolysis membrane based on nickel hydroxyl oxide, specifically including the following steps:

[0057] (1) Dissolve 74.7 mg of nickel acetate (NiAc) and 120.1 mg of urea in 50 mL of distilled water, then add 0.1 g of polyvinylpyrrolidone (PVP). Stir the resulting solution magnetically for 30 min at room temperature, then transfer it to a 100 mL high-pressure reactor lined with polytetrafluoroethylene. Place the reactor in an oven and react at 100 °C for 24 h. After cooling naturally to room temperature, transfer the solution to a centrifuge tube and centrifuge at 6000 rpm for 5 min. Collect the precipitate and wash it three times with water and ethanol respectively. Finally, place the product in a vacuum drying oven and dry it at 50 °C for 12 h to obtain matcha green NiOOH powder. Figure 1 XRD pattern of NiOOH powder. Figure 2 Thermogravimetric analysis (TGA) diagram of NiOOH powder. Figure 3 The image shows a scanning electron microscope (SEM) image of NiOOH powder. As can be seen from the image, NiOOH powder was successfully synthesized. The particle size of the synthesized NiOOH powder is 200nm-250nm, and the NiOOH nanosheets have regular hexagonal shapes. The decomposition temperature of the NiOOH powder is around 155℃.

[0058] (2) Preparation of casting solution: Add 12.5g of N-methylpyrrolidone (NMP) to a 100mL three-necked beaker. Install the mechanical stirrer at the mouth of the middle beaker and slowly add 4.5g of polysulfone (PSF) powder to NMP at a stirring speed of 200rpm. Stir until it is basically dissolved. Then mix 4g of NMP and 10mg of polyvinyl alcohol (PVA) in a sample bottle and dissolve them completely in an oil bath at 95℃. Add the mixture to the NMP and PSF mixture. Then add 3g of polyvinylpyrrolidone (PVP) and continue stirring until PVP is completely dissolved to form a uniform and transparent solution. Then add 6g of the prepared NiOOH powder and increase the stirring speed to 300rpm (to ensure sufficient dispersion and not introduce too many bubbles). Continue stirring for 12h to make the NiOOH nanoparticles uniformly dispersed in the polymer solution to obtain the casting solution.

[0059] (3) Transfer the prepared casting solution to a suitable container and place it in a vacuum drying oven. Vacuum for 12 hours at room temperature until no obvious bubbles are generated in the casting solution. Pour the fully degassed casting solution onto a clean and flat substrate glass plate and use a 300μm scraper to scrape it at a uniform speed to form a uniform liquid film. Immediately immerse the substrate with the wet film into deionized water at room temperature for a coagulation bath. Keep it submerged for 15 minutes to allow the solvent (NMP) to exchange with the water, and the polymer precipitates out to form a wet composite membrane with a microporous structure.

[0060] (4) Take the solidified wet composite membrane with microporous structure out of the coagulation bath, rinse the membrane surface with a large amount of deionized water to thoroughly remove residual solvent and possible impurities, place the cleaned wet membrane on clean filter paper to absorb excess surface moisture, and then transfer the wet membrane to a vacuum drying oven and dry it at 50°C for 12 hours to completely remove the moisture inside the membrane, and obtain the final alkaline water electrolysis NiOOH / PSF composite microporous membrane. The dried membrane should be stored in a desiccator for later use.

[0061] Figure 4 This is a scanning electron microscope image of the surface of the NiOOH / PSF composite microporous membrane. Figure 5 The image shows a scanning electron microscope (SEM) image of the cross-section of a NiOOH / PSF composite microporous membrane. As can be seen from the image, NiOOH nanoparticles are uniformly attached to the surface of the membrane, and the pore size of the membrane is about 10 μm. The cross-section is mostly sponge-like.

[0062] Figure 6 The figure shows the tensile strength test results of the NiOOH / PSF composite microporous membrane. Table 1 shows the tensile strength test parameters and data of the NiOOH / PSF composite microporous membrane. It can be seen that the tensile strength of the NiOOH / PSF composite microporous membrane is 29.28 MPa.

[0063] Table 1. Tensile strength test parameters and data of NiOOH / PSF composite microporous membrane

[0064]

[0065] Figure 7 The figure shows the contact angle test results of the NiOOH / PSF composite microporous membrane. As can be seen from the figure, the contact angle of the membrane is 60.3°, which indicates good hydrophilicity.

[0066] Figure 8 Table 2 shows the surface resistivity test results for the NiOOH / PSF composite microporous membrane. It can be seen that the surface resistivity of the NiOOH / PSF composite microporous membrane is 0.324 Ω cm⁻¹. -2 (The blank group is the group without a diaphragm. The national standard specifies the resistance value of the diaphragm of a certain area and the resistance value of a potassium hydroxide solution of the same concentration and area. The product of the difference between the two and the diaphragm area is the surface resistance of the diaphragm.) Table 3 shows the test data of the alkali absorption rate of the NiOOH / PSF composite microporous diaphragm. The method refers to the electronic industry standard SJ / T 10171.7-91 "Determination of Alkali Absorption Rate of Diaphragm" and the alkali absorption rate is about 400%. The high alkali absorption rate of the diaphragm means that it has a rich microporous structure and hydrophilic groups, which can quickly and in large quantities adsorb and store electrolyte. This reflects that the composite microporous diaphragm has extremely high alkali absorption capacity and hydrophilicity, which is conducive to the transport of hydroxide ions and the discharge of product gases.

[0067] Table 2. Test data of surface resistivity of NiOOH / PSF composite microporous membrane

[0068]

[0069] The sheet resistivity of the composite diaphragm was measured to be 0.324 Ω cm. -2 The measured thickness of the film is 0.16 mm;

[0070] Table 3. Alkali Absorption Rate Test Data of NiOOH / PSF Composite Microporous Membrane

[0071]

[0072] Note: Samples H1 and H2 are samples from different batches of NiOOH / PSF composite microporous membranes.

[0073] Example 2

[0074] This invention provides a method for preparing an alkaline water electrolysis membrane based on nickel hydroxyl oxide, specifically including the following steps:

[0075] (1) In a 150mL beaker placed in an ice bath, add 80mL of deionized water to dissolve 7g of potassium hydroxide (KOH) and 8mL of concentrated ammonia. Then, add 10g of β-Ni(OH)2 powder to the solution and mechanically stir at room temperature for 30min. After stirring, transfer the beaker to a water bath and heat it to 60℃ and maintain this temperature while stirring. Add potassium persulfate (K2S2O8) in six batches, 6.3g each time, with an interval of about 10min. Stop stirring when the reaction solution turns black and no oxygen bubbles are generated. Filter the reaction mixture under vacuum. Wash the resulting solid precipitate repeatedly with hot water at 80℃ until the pH of the filtrate reaches 7-8. Finally, dry the product in a vacuum drying oven at 60℃ for 12h to obtain black NiOOH powder. Figure 9 XRD pattern of NiOOH powder. Figure 10 Thermogravimetric analysis (TGA) diagram of NiOOH powder. Figure 11 The image shows a scanning electron microscope (SEM) image of NiOOH powder. As can be seen from the image, NiOOH powder was successfully synthesized; the NiOOH nanosheets exhibit a relatively obvious plate-like or needle-like morphology; and the decomposition temperature is around 220℃.

[0076] (2) Preparation of casting solution: Add 12.5g of N-methylpyrrolidone to a 100mL three-necked beaker. Install the mechanical stirrer at the mouth of the middle beaker and slowly add 4.5g of polysulfone powder to NMP at a stirring speed of 200rpm. Stir until it is basically dissolved. Then mix 4g of NMP and 10mg of polyvinyl alcohol (PVA) in a sample bottle and dissolve them completely in an oil bath at 95℃. Then add the mixture of NMP and PSF. Then add 3g of polyvinylpyrrolidone (PVP) and continue stirring until PVP is completely dissolved to form a uniform and transparent solution. Then add 6g of the prepared NiOOH powder and adjust the stirring speed to 300rpm (to ensure sufficient dispersion and not introduce too many bubbles). Continue stirring for 12h to make the NiOOH nanoparticles uniformly dispersed in the polymer solution to obtain the casting solution.

[0077] (3) Transfer the prepared casting solution to a suitable container and place it in a vacuum drying oven. Vacuum the container at room temperature for 12 hours until no obvious bubbles are generated in the casting solution. Pour the fully degassed casting solution onto a clean and flat substrate glass plate and use a 300μm scraper to scrape it at a uniform speed to form a uniform liquid film. Immediately immerse the substrate with the wet film into a deionized water coagulation bath at room temperature and keep it submerged for 15 minutes to allow the solvent (NMP) and non-solvent (water) to exchange, and the polymer precipitates out to form a wet composite membrane with a microporous structure.

[0078] (4) Take the solidified wet composite membrane with microporous structure out of the coagulation bath, rinse the membrane surface with a large amount of deionized water to thoroughly remove residual solvent and possible impurities, place the cleaned wet membrane on clean filter paper to absorb excess surface moisture, and then transfer the wet membrane to a vacuum drying oven and dry it at 50°C for 12 hours to completely remove the moisture inside the membrane, so as to obtain the final alkaline water electrolysis NiOOH / PSF / PVP composite microporous membrane. The dried membrane should be stored in a desiccator for later use.

[0079] Figure 12 This is a scanning electron microscope image of the surface of the NiOOH / PSF / PVP composite microporous membrane. Figure 13 The image shows a scanning electron microscope (SEM) image of the cross-section of the NiOOH / PSF / PVP composite microporous membrane. As can be seen from the image, the membrane surface has abundant pores, and NiOOH nanoparticles are uniformly distributed on the surface. The cross-section has many sponge-like pores, and the nanoparticles are well dispersed. The proportion of NiOOH in the dry membrane is 15%-25%.

[0080] Figure 14 The figure shows the tensile strength test results of the NiOOH / PSF / PVP composite microporous membrane. Table 4 shows the tensile strength test parameters and data of the NiOOH / PSF / PVP composite microporous membrane. It can be seen that its tensile strength is 21.01 MPa.

[0081] Table 4 Tensile strength test parameters and data of NiOOH / PSF / PVP composite microporous membrane

[0082]

[0083] Figure 15 The figure shows the contact angle test results of the NiOOH / PSF / PVP composite microporous membrane. As can be seen from the figure, the contact angle is 68.9°, indicating good hydrophilicity.

[0084] Figure 16 Table 5 shows the surface resistivity test results for the NiOOH / PSF / PVP composite microporous membrane. The results indicate that the surface resistivity of the NiOOH / PSF / PVP composite microporous membrane is 0.209 Ω cm⁻¹. -2 (The blank group is the group without a diaphragm. The national standard specifies the resistance value of the diaphragm of a certain area and the resistance value of a potassium hydroxide solution of the same concentration and area. The product of the difference between the two and the diaphragm area is the surface resistance of the diaphragm.) Table 6 shows the alkali absorption rate test data of the NiOOH / PSF / PVP composite microporous diaphragm. The alkali absorption rate is about 260%. The alkali absorption rate of 260% indicates that the diaphragm still has good hydrophilicity and sufficient liquid absorption capacity, which can ensure the basic ionic conductivity requirements. However, compared with Example 1, the decrease in alkali absorption rate means that the pore size of the diaphragm is larger and the pore morphology is changed. More through pores appear instead of closed pores, and the density of hydrophilic groups on the surface is relatively reduced.

[0085] Table 5. Surface resistivity test data of NiOOH / PSF / PVP composite microporous membrane

[0086]

[0087] The sheet resistivity of the composite diaphragm was measured to be 0.209 Ω cm. -2 ;

[0088] Table 6. Alkali Absorption Rate Test Data of NiOOH / PSF / PVP Composite Microporous Membrane

[0089]

[0090] Note: Samples H1 and H2 are samples from different batches of NiOOH / PSF composite microporous membranes.

[0091] Figure 17 The figure shows the voltage test results of the NiOOH / PSF / PVP composite microporous membrane chamber in Example 2. Nickel felt was used as the catalyst at both the anode and cathode of the electrolyzer. As can be seen from the figure, the NiOOH / PSF / PVP composite microporous membrane was used in water electrolysis to achieve a voltage of 5000 A / m. 2The high current density of @2V significantly outperforms the performance of commercial membranes (3500A / m). 2 @2V~UTP500).

[0092] Example 3

[0093] This invention provides a method for preparing an alkaline water electrolysis membrane based on nickel hydroxyl oxide, specifically including the following steps:

[0094] (1) Dissolve 74.7 mg of nickel acetate (NiAc) and 120.1 mg of urea in 50 mL of distilled water, then add 0.1 g of polyvinylpyrrolidone (PVP). Stir the resulting solution magnetically for 30 min at room temperature, then transfer it to a 100 mL high-pressure reactor lined with polytetrafluoroethylene. Place the reactor in an oven and react at 100 °C for 24 h. After cooling naturally to room temperature, transfer the solution to a centrifuge tube and centrifuge at 6000 rpm for 5 min. Collect the precipitate and wash it three times with water and ethanol respectively. Finally, place the product in a vacuum drying oven and dry it at 50 °C for 12 h to obtain matcha green NiOOH powder.

[0095] (2) Preparation of casting solution: Add 20g of N-methylpyrrolidone to a 100mL three-necked beaker, install the mechanical stirrer at the mouth of the middle beaker, and slowly add 8g of polysulfone powder to NMP at a stirring speed of 200rpm. Stir until it is basically dissolved. Then mix 6g of NMP and 10mg of polyvinyl alcohol (PVA) in a sample bottle and dissolve them completely in an oil bath at 95℃. Then add the mixture of NMP and PSF, followed by 2g of polyvinylpyrrolidone (PVP). Continue stirring until PVP is completely dissolved to form a uniform and transparent solution. Then add 4g of the prepared NiOOH powder, adjust the stirring speed to 300rpm (to ensure sufficient dispersion and not introduce too many bubbles), and continue stirring for 12h to make the NiOOH nanoparticles uniformly dispersed in the polymer solution to obtain the casting solution.

[0096] (3) Transfer the prepared casting solution to a suitable container and place it in a vacuum drying oven. Vacuum the container at room temperature for 12 hours until no obvious bubbles are generated in the casting solution. Pour the fully degassed casting solution onto a clean and flat substrate glass plate and use a 300μm scraper to scrape it at a uniform speed to form a uniform liquid film. Immediately immerse the substrate with the wet film into a deionized water coagulation bath at room temperature and keep it submerged for 15 minutes to allow the solvent (NMP) and non-solvent (water) to exchange, and the polymer precipitates out to form a wet composite membrane with a microporous structure.

[0097] (4) Take the solidified wet composite membrane with microporous structure out of the coagulation bath, rinse the membrane surface with a large amount of deionized water to thoroughly remove residual solvent and possible impurities, place the cleaned wet membrane on clean filter paper to absorb excess surface moisture, and then transfer the wet membrane to a vacuum drying oven and dry it at 50°C for 12 hours to completely remove the moisture inside the membrane, and obtain the final alkaline water electrolysis NiOOH / PSF composite microporous membrane. The dried membrane should be stored in a desiccator for later use.

[0098] Figure 18 The figure shows the tensile strength test results of the NiOOH / PSF composite microporous membrane. Table 7 shows the tensile strength test parameters and data of the NiOOH / PSF composite microporous membrane. It can be seen that its tensile strength is 16.53 MPa.

[0099] Table 7 Tensile strength test parameters and data for NiOOH / PSF composite microporous membranes

[0100]

[0101] Figure 19 The figure shows the contact angle test results for the NiOOH / PSF composite microporous membrane. As can be seen from the figure, its contact angle is 100.9°.

[0102] Figure 20 The diagram shows the surface resistivity of the NiOOH / PSF composite microporous membrane. Table 5 shows the surface resistivity test data for the NiOOH / PSF composite microporous membrane, indicating that its surface resistivity is 0.173 Ω cm. -2 (The blank group is the group without a separator. The national standard specifies the resistance value of the separator by area and the resistance value of a potassium hydroxide solution of the same concentration and area. The product of the difference between the two and the separator area is the sheet resistance of the separator.) Table 9 shows the test data of alkali absorption rate of NiOOH / PSF composite microporous separator. The average alkali absorption rate is about 311%, which indicates that the inherent strong hydrophilicity and porous characteristics of the NiOOH / PSF composite material system can provide sufficient ion transport channels for alkaline batteries.

[0103] Table 8. Test data of surface resistance of NiOOH / PSF composite microporous membrane

[0104]

[0105] The sheet resistivity of the composite diaphragm was measured to be 0.173 Ω cm. -2 ;

[0106] Table 9. Alkali Absorption Rate Test Data of NiOOH / PSF Composite Microporous Membrane

[0107]

[0108] Note: Samples H1 and H2 are samples from different batches of NiOOH / PSF composite microporous membranes.

[0109] Example 4

[0110] This invention provides a method for preparing an alkaline water electrolysis membrane based on nickel hydroxyl oxide, specifically including the following steps:

[0111] (1) In a 150mL beaker placed in an ice bath, add 80mL of deionized water to dissolve 7g of potassium hydroxide (KOH) and 8mL of concentrated ammonia. Then, add 10g of β-Ni(OH)2 powder to the solution and mechanically stir at room temperature for 30min. After stirring, transfer the beaker to a water bath and heat it to 60℃ and maintain this temperature while stirring. Add potassium persulfate (K2S2O8) in six batches, 6.3g each time, with an interval of about 10min. Stop stirring when the reaction solution turns black and no oxygen bubbles are generated. Filter the reaction mixture under vacuum. Wash the resulting solid precipitate repeatedly with hot water at 80℃ until the pH of the filtrate reaches 7-8. Finally, dry the product in a vacuum drying oven at 60℃ for 12h to obtain black NiOOH powder.

[0112] (2) Preparation of casting solution: Add 20g of N-methylpyrrolidone to a 100mL three-necked beaker, install the mechanical stirrer at the mouth of the middle beaker, and slowly add 8g of polysulfone powder to NMP at a stirring speed of 200rpm. Stir until it is basically dissolved. Then mix 6g of NMP and 10mg of polyvinyl alcohol (PVA) in a sample bottle and dissolve them completely in an oil bath at 95℃. Then add the mixture of NMP and PSF, followed by 2g of polyvinylpyrrolidone (PVP). Continue stirring until PVP is completely dissolved to form a uniform and transparent solution. Then add 4g of the prepared NiOOH powder, adjust the stirring speed to 300rpm (to ensure sufficient dispersion and not introduce too many bubbles), and continue stirring for 12h to make the NiOOH nanoparticles uniformly dispersed in the polymer solution to obtain the casting solution.

[0113] (3) Transfer the prepared casting solution to a suitable container and place it in a vacuum drying oven. Vacuum the container at room temperature for 12 hours until no obvious bubbles are generated in the casting solution. Pour the fully degassed casting solution onto a clean and flat substrate glass plate and use a 300μm scraper to scrape it at a uniform speed to form a uniform liquid film. Immediately immerse the substrate with the wet film into a deionized water coagulation bath at room temperature and keep it submerged for 15 minutes to allow the solvent (NMP) and non-solvent (water) to exchange, and the polymer precipitates out to form a wet composite membrane with a microporous structure.

[0114] (4) Take the solidified wet composite membrane with microporous structure out of the coagulation bath, rinse the membrane surface with a large amount of deionized water to thoroughly remove residual solvent and possible impurities, place the cleaned wet membrane on clean filter paper to absorb excess surface moisture, and then transfer the wet membrane to a vacuum drying oven and dry it at 50°C for 12 hours to completely remove the moisture inside the membrane, and obtain the final alkaline water electrolysis NiOOH / PSF composite microporous membrane. The dried membrane should be stored in a desiccator for later use.

[0115] Figure 21 The figure shows the tensile strength test results of the NiOOH / PSF / PVP composite microporous membrane. Table 10 shows the tensile strength test parameters and data of the NiOOH / PSF / PVP composite microporous membrane. It can be seen that its tensile strength is 22.24 MPa.

[0116] Table 10 Tensile strength test parameters and data for NiOOH / PSF / PVP composite microporous membranes

[0117]

[0118] Figure 22 The figure shows the contact angle test results for the NiOOH / PSF / PVP composite microporous membrane. As can be seen from the figure, the contact angle is 102.4°.

[0119] Figure 23 The diagram shows the surface resistivity of the NiOOH / PSF / PVP composite microporous membrane. Table 11 shows the surface resistivity test data for the NiOOH / PSF / PVP composite microporous membrane. It can be seen that the surface resistivity is 0.606 Ω cm. -2 (The blank group is the group without a diaphragm. The national standard specifies the resistance value of the diaphragm of a certain area and the resistance value of a potassium hydroxide solution of the same concentration and area. The product of the difference between the two and the diaphragm area is the surface resistance of the diaphragm.) Table 12 shows the alkali absorption rate test data of the NiOOH / PSF / PVP composite microporous diaphragm. Its average alkali absorption rate is 340%, which means that the diaphragm has extremely high potential for ionic conductivity.

[0120] Table 11. Test data of surface resistivity of NiOOH / PSF / PVP composite microporous membrane

[0121]

[0122] The sheet resistivity of the composite diaphragm was measured to be 0.606 Ω cm. -2 ;

[0123] Table 12 Alkali Absorption Rate Test Data of NiOOH / PSF / PVP Composite Microporous Membrane

[0124]

[0125] Note: Samples H1 and H2 are samples of NiOOH / PSF / PVP composite microporous membranes from different batches.

[0126] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. 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. Such 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. An alkaline water electrolysis membrane based on nickel hydroxyl oxide, characterized in that, The alkaline water electrolysis membrane is prepared by phase inversion method, wherein the inorganic nanofiller is selected as nano-nickel hydroxyl oxide (NiOOH).

2. The alkaline water electrolysis membrane based on nickel hydroxyl oxide according to claim 1, characterized in that, The mass percentage of the nano-hydroxy nickel oxide in the casting solution is 10-20%, and the particle size of the nano-hydroxy nickel oxide is 200-250 nm.

3. The alkaline water electrolysis membrane based on nickel hydroxyl oxide according to claim 2, characterized in that, The casting solution comprises the following raw materials by mass percentage: N-methylpyrrolidone: polysulfone: polyvinylpyrrolidone: NiOOH = 55-65%: 15-20%: 5-10%: 10-20%.

4. The alkaline water electrolysis membrane based on nickel hydroxyl oxide according to claim 1, characterized in that, The preparation method of the nano-nickel hydroxyl oxide is as follows: Nickel acetate and urea are dissolved in distilled water, then polyvinylpyrrolidone is added and stirred until homogeneous. The mixture is then reacted at 80-100℃ for 12-36 hours and cooled to room temperature to obtain the product, which is a matcha-green NiOOH powder.

5. The alkaline water electrolysis membrane based on nickel hydroxyl oxide according to claim 4, characterized in that, The mass ratio of the nickel acetate, the urea, the distilled water, and the polyvinylpyrrolidone is 74.7:120.1:

100.

6. The alkaline water electrolysis membrane based on nickel hydroxyl oxide according to claim 1, characterized in that, The preparation method of the nano-nickel hydroxyl oxide is as follows: Dissolve potassium hydroxide and concentrated ammonia in deionized water, then add β-Ni(OH)2 and stir until homogeneous. Then heat to 45-65℃ and add potassium persulfate in batches to react. The reaction continues until the reaction solution turns black and no oxygen bubbles are produced. The product obtained is black NiOOH powder.

7. The alkaline water electrolysis membrane based on nickel hydroxyl oxide according to claim 6, characterized in that, The mass-to-volume ratio of the potassium hydroxide, the concentrated ammonia, the deionized water, and the β-Ni(OH)2 is 7g:8mL:80mL:10g.

8. A method for preparing an alkaline water electrolysis membrane based on nickel hydroxyl oxide according to any one of claims 1-7, characterized in that, Specifically, the following steps are included: (1) Preparation of casting solution: Polysulfone powder, polyvinyl alcohol and polyvinylpyrrolidone are added to N-methylpyrrolidone in sequence to form a uniform and transparent solution. Then, nano-nickel hydroxyl oxide is added and stirred evenly to obtain the casting solution. (2) After the casting solution is degassed, a uniform liquid film is formed on the substrate, and then it is immersed in deionized water for phase transformation to form a wet composite membrane with a microporous structure. (3) The wet composite membrane is washed and dried to obtain an alkaline water electrolysis membrane based on nickel hydroxy oxide.

9. The method for preparing an alkaline water electrolysis membrane based on nickel hydroxyl oxide according to claim 8, characterized in that, The stirring time in step (1) is 8-24 hours; The phase transformation time described in step (2) is 5-30 min; The drying conditions described in step (3) are: drying at 50-60℃ for 12-24 hours.

10. The application of the alkaline water electrolysis membrane based on nickel hydroxyl oxide according to any one of claims 1-7 in the field of water electrolysis.

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