Alkaline water electrolysis membrane

Abstract

The present invention relates to an alkaline water electrolysis membrane in which the volume of a polymer mesh support included in the membrane is optimized, and thus mesh exposure and defects such as bending and cracking do not occur when fastened to a cell and the mechanical properties and durability of the membrane are maintained.

Description

alkaline water electrolysis membrane

[0001] Cross-citation with related applications

[0002] The present application claims the benefit of priority based on Korean Patent Application No. 10-2024-0170584 filed on November 26, 2024 and Korean Patent Application No. 10-2025-0171723 filed on November 13, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of the specification.

[0003] Technology field

[0004] The present invention relates to an alkaline water electrolysis membrane.

[0005]

[0006] Water electrolysis technology is a method of producing hydrogen in an eco-friendly manner by electrically decomposing water, and its high potential and importance as a clean energy source are being emphasized. The performance and durability of such water electrolysis systems are primarily determined by the characteristics of the membrane, and in particular, the durability and mechanical properties of the membrane have a significant impact on the stability and long-term performance of the system.

[0007] Water electrolysis systems are broadly classified into polymer electrolysis using polymer electrolyte membranes (PEM), alkaline electrolysis using alkaline aqueous solutions as electrolytes (AEC), anion electrolysis using anion exchange membranes (AEM), and solid oxide electrolysis using solid oxides as electrolytes (SOEC). Among these, alkaline electrolysis membranes used in alkaline electrolysis operate in an alkaline electrolyte environment and have the advantage of maintaining high mechanical strength and durability through their porous structure.

[0008] Conventional alkaline water electrolysis membranes were mainly composed of ceramic mixed compositions, but these compositions had problems with reduced mechanical properties and durability upon repeated use, causing the membranes to be easily damaged or deformed (curled, cracked), and these defects reduced the efficiency and stability of the electrolytic cell.

[0009] To solve this, a technology was introduced to insert a polymer mesh structure as a reinforcing support into a membrane composed solely of a ceramic mixed composition. While this polymer mesh has the effect of improving mechanical strength and durability by reinforcing the physical properties of the membrane, it was difficult to consistently ensure the performance of the membrane due to ambiguous optimization criteria for the polymer mesh.

[0010] Accordingly, there is a need for research on alkaline water electrolysis membranes that improve the mechanical strength and durability of the membrane while preventing defects by controlling the volume characteristics of the polymer mesh included in the membrane.

[0011]

[0012] The problem to be solved by the present invention is to provide an alkaline water electrolysis membrane that optimizes the volume of the polymer mesh support itself included in the porous membrane, thereby maintaining the mechanical properties and durability of the membrane while preventing defects such as mesh exposure, bending, and cracking when fastened to a cell.

[0013]

[0014] To solve the above-mentioned problem, the present invention provides an alkaline water electrolysis membrane.

[0015] More specifically, (1) the present invention provides an alkaline water electrolysis membrane comprising: a polymer mesh support; and a coating layer formed on the polymer mesh support and comprising ceramic particles and a polymer binder, wherein the volume percentage of the polymer mesh support calculated by the following formula 1 is 11% or more and 19% or less.

[0016] [Equation 1]

[0017] Volume percentage (%) = (Volume of polymer mesh support contained in unit cell / Volume of unit cell) * 100,

[0018] In the above Equation 1, the unit cell is a rectangular prism having a height corresponding to the thickness of the membrane, and a square formed by connecting the points where the longitudinal rotation axes of the vertical strands and the horizontal strands intersect when the two horizontal strands and two vertical strands of the polymer mesh support are arranged vertically.

[0019] (2) The present invention provides an alkaline water electrolysis membrane according to (1), wherein the volume percentage of the polymer mesh support is 13% or more and 19% or less.

[0020] (3) The present invention provides an alkaline water electrolysis membrane in which, in either (1) or (2) above, the polymer mesh support comprises one or more selected from the group consisting of polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), polysulfone (PSU), polyether ether ketone (PEEK), polypropylene (PP), polyether sulfone (PES), polyethylene terephthalate (PET), and polyamide (PA).

[0021] (4) The present invention provides an alkaline water electrolysis membrane in which, in any one of (1) to (3), the ceramic particles comprise one or more selected from the group consisting of ZrO2, NiO, Co3O4, TiO2, Fe3O4, CeO2, HfO2, Al2O3, SiO2 and Y2O3.

[0022] (5) The present invention provides an alkaline water electrolysis membrane in which, in any one of (1) to (4), the polymer binder comprises one or more selected from the group consisting of polysulfone (PSU), polyethersulfone (PES), polyphenylsulfone (PPSU), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN) and polyethylene oxide (PEO).

[0023] (6) The present invention provides an alkaline water electrolysis membrane in which, in any one of (1) to (5), the ceramic particles are 50% by weight or more and 80% by weight or less, and the polymer binder is 10% by weight or more and 20% by weight or less, based on the total weight of the alkaline water electrolysis membrane.

[0024] (7) The present invention provides an alkaline water electrolysis membrane having a thickness of 150 μm or more and 600 μm or less, in any one of (1) to (6).

[0025] (8) The present invention provides an alkaline water electrolysis membrane in which, in any one of (1) to (7), the mesh number calculated as the number of unit cells per inch is 30 or more and 250 or less.

[0026] (9) The present invention provides an alkaline water electrolysis membrane in which, in any one of (1) to (8), the diameter of the polymer mesh support is 30 μm or more and 180 μm or less.

[0027] (10) The present invention provides an alkaline water electrolysis membrane in which, in any one of (1) to (9), the bottom surface of the unit cell is a square with a side length of 100 μm or more and 700 μm or less.

[0028] (11) The present invention provides an alkaline water electrolysis membrane in which, in any one of (1) to (10), when a pressure is applied to a membrane filled with water while gradually increasing the pressure from 0 bar using nitrogen gas, the bubble point pressure obtained by measuring the pressure at which bubbles are generated is 2 bar or more and 6 bar or less.

[0029]

[0030] The alkaline water electrolysis membrane according to the present invention includes a polymer mesh support as a reinforcing support, and the volume percentage of the polymer mesh support included in the unit cell is optimized so that no defects occur when the cell is connected, while maintaining the mechanical properties and durability of the membrane.

[0031]

[0032] FIG. 1 is a conceptual diagram showing the shape of a unit cell of the present invention in three dimensions.

[0033] FIG. 2 is a conceptual diagram showing a plan view of the membrane of the present invention as seen horizontally from above and a front view as seen from the front.

[0034]

[0035] The present invention will be described in more detail below.

[0036] Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0037]

[0038] alkaline water electrolysis membrane

[0039] The present invention provides an alkaline water electrolysis membrane comprising: a polymer mesh support; and a coating layer formed on the polymer mesh support and comprising ceramic particles and a polymer binder, wherein the volume percentage of the polymer mesh support calculated by Formula 1 below is 11 to 19%.

[0040] [Equation 1]

[0041] Volume percentage (%) = (Volume of polymer mesh support contained in unit cell / Volume of unit cell) * 100,

[0042] In the above Equation 1, the unit cell is a rectangular prism having a height corresponding to the thickness of the membrane, and a square formed by connecting the points where the longitudinal rotation axes of the vertical strands and the horizontal strands intersect when the two horizontal strands and two vertical strands of the polymer mesh support are arranged vertically.

[0043]

[0044] The alkaline water electrolysis membrane of the present invention will be described in detail below.

[0045] The polymer mesh support included in the alkaline water electrolysis membrane of the present invention supports the membrane and performs the role of improving mechanical properties and durability. The polymer mesh support may include one or more selected from the group consisting of polyphenylene sulfide mesh (PPS Mesh), polytetrafluoroethylene mesh (PTFE Mesh), polysulfone mesh (PSU Mesh), polyether ether ketone mesh (PEEK Mesh), polypropylene mesh (PP Mesh), polyether sulfone (PES), polyethylene terephthalate (PET), and polyamide (PA), and preferably may be polyphenylene sulfide mesh (PPS Mesh). When the above polymer mesh support is appropriately selected, the membrane can be kept chemically stable even in an alkaline environment, which can increase the lifespan of the membrane and increase ion conductivity. Additionally, the pore structure and density of the membrane can be optimized, which can lead to increased cell coupling suitability and reduced gas crossover.

[0046] The ceramic particles included in the alkaline water electrolysis membrane of the present invention serve to provide a pathway for ion conduction and increase mechanical stability. Specifically, the ceramic particles may include one or more selected from the group consisting of ZrO2, NiO, Co3O4, TiO2, Fe3O4, CeO2, HfO2, Al2O3, SiO2, and Y2O3, and preferably may be ZrO2. When the ceramic particles are appropriately selected, the efficiency of the alkaline water electrolysis reaction can be increased, and the thermal stability of the membrane can be enhanced to maintain stable performance even at high temperatures.

[0047] The polymer binder included in the alkaline water electrolysis membrane of the present invention can provide structural and electrochemical stability to the membrane and perform the role of blocking gas, and specifically may include one or more selected from the group consisting of polysulfone (PSU), polyethersulfone (PES), polyphenylsulfone (PPSU), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), and polyethylene oxide (PEO). When the polymer binder is appropriately selected, the performance and durability of the membrane can be significantly improved, and the gas blocking function can be enhanced to reduce gas crossover.

[0048] The alkaline water electrolysis membrane of the present invention may include a coating layer formed on the polymer mesh support and comprising a polymer binder and ceramic particles. The content of the ceramic particles may be 50 wt% or more, 51 wt% or more, 52 wt% or more, 53 wt% or more, 54 wt% or more, 55 wt% or more, 56 wt% or more, 57 wt% or more, 58 wt% or more, 59 wt% or more, or 60 wt% or more, and 80 wt% or less, 79 wt% or less, 78 wt% or less, 77 wt% or less, 76 wt% or less, 75 wt% or less, 74 wt% or less, 73 wt% or less, 72 wt% or less, 71 wt% or less, or 70 wt% or less.

[0049] In addition, the content of the polymer binder may be 10 wt% or more, 11 wt% or more, 12 wt% or more, 13 wt% or more, or 14 wt% or more, and 20 wt% or less, 19 wt% or less, 18 wt% or less, 17 wt% or less, 16 wt% or less, or 15 wt% or less, based on the total weight of the alkaline water electrolysis membrane.

[0050] When the content of polymer binder and ceramic particles is maintained appropriately, the mechanical strength and durability of the membrane can be improved, and the ion conductivity can be optimized, which can significantly improve the performance and stability of the overall water electrolysis system.

[0051] Additionally, the coating layer may include a polymer additive capable of promoting pore formation. Specifically, the polymer additive may include one or more selected from the group consisting of polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetate, glycerol, and triethylene glycol, and preferably may be polyvinylpyrrolidone.

[0052] The content of the above polymer additive may be 0.1 wt% or more, 0.2 wt% or more, 0.3 wt% or more, 0.4 wt% or more, or 0.5 wt% or more, and 2.5 wt% or less, 2.4 wt% or less, 2.3 wt% or less, 2.2 wt% or less, 2.1 wt% or less, or 2.0 wt% or less, based on the total weight of the alkaline water electrolysis membrane.

[0053] The volume percentage of the polymer mesh support included in the alkaline water electrolysis membrane of the present invention may be 11% or more and 19% or less, preferably 11.0% or more, 11.2% or more, 11.4% or more, 11.6% or more, 11.8% or more, 12.0% or more, 12.2% or more, 12.4% or more, 12.6% or more, 12.8% or more, or 13.0% or more, and may be 19.0% or less, 18.8% or less, 18.6% or less, 18.4% or less, 18.2% or less, 18.0% or less, 17.8% or less, 17.6% or less, 17.4% or less, 17.2% or less, 17.0% or less, 16.0% or less, or 15.0% or less. When the volume percentage of the polymer mesh support is maintained within the above range, defects caused by curl, crack, or exposure of the polymer mesh during cell fastening can be minimized, thereby enabling stable cell fastening while improving the mechanical properties and durability of the membrane.

[0054] The above unit cell is defined as a rectangular prism having a height corresponding to the thickness of the membrane, and having a square base formed by connecting the points where the longitudinal rotation axes of the vertical and horizontal strands intersect when two horizontal strands and two vertical strands of the polymer mesh support are arranged vertically. The volume of the unit cell can be obtained by multiplying the area of ​​the base by the thickness of the membrane.

[0055] Specifically, the base of the unit cell may be a square, and the length of one side of the square may be 100 µm or more and 700 µm or less, preferably 400 µm or more, 420 µm or more, 440 µm or more, 460 µm or more, 480 µm or more, or 500 µm or more, and may be 700 µm or less, 690 µm or less, 680 µm or less, 670 µm or less, 660 µm or less, 650 µm or less, 640 µm or less, 630 µm or less, 620 µm or less, 610 µm or less, or 600 µm or less. The length of one side of the square may be defined as the length of the unit cell.

[0056] In addition, the wire diameter of the polymer mesh support included in the unit cell may be 30㎛ or more and 180㎛ or less, and preferably 100㎛ or more, 105㎛ or more, 110㎛ or more, 115㎛ or more, 120㎛ or more, 125㎛ or more, 130㎛ or more, 135㎛ or more, 140㎛ or more, or 145㎛ or more, and may be 180㎛ or less, 175㎛ or less, 170㎛ or less, 165㎛ or less, 160㎛ or less, 155㎛ or less, or 150㎛ or less.

[0057] When the length of one side of the bottom surface of the unit cell and the wire diameter of the polymer mesh support are maintained within the above range, the membrane can maintain an appropriate thickness, and the porosity and mechanical properties of the membrane can be improved.

[0058] The thickness of the alkaline water electrolysis membrane of the present invention may be 150 μm or more and 600 μm or less, preferably 300 μm or more, 320 μm or more, 340 μm or more, 360 μm or more, 380 μm or more, or 400 μm or more, and may be 600 μm or less, 580 μm or less, 560 μm or less, 540 μm or less, 520 μm or less, 500 μm or less, 480 μm or less, 460 μm or less, or 440 μm or less. The thickness of the membrane can be controlled by the coating gap, and when the thickness is maintained within the above range, the durability and mechanical strength of the membrane can be enhanced, the bubble point pressure can be optimized, and this can lead to cell results. In particular, when the thickness of the alkaline water electrolysis membrane is thick, there is an advantage of higher tensile strength compared to a thin membrane.

[0059] The mesh number of the alkaline water electrolysis membrane of the present invention may be 30 or more and 250 or less, preferably 30 or more, 32 or more, 34 or more, 36 or more, 38 or more, or 40 or more, and may be 80 or less, 75 or less, 70 or less, 65 or less, 60 or less, or 55 or less. When the mesh number is appropriately maintained, the mechanical strength of the membrane can be increased to improve durability, and ion conductivity can be appropriately maintained.

[0060] The thickness, mesh number, wire diameter, and side length of the unit cell of the above alkaline water electrolysis membrane can be measured using a thickness gauge and a microscope. Specifically, the thickness of the membrane can be calculated as the average value obtained by measuring at five points using a contact thickness gauge (Teclock, PG-02). In addition, the unit cell length according to the mesh number can be calculated by averaging the values ​​measured at three or more points using an optical microscope (100x magnification, using a calibrator). Furthermore, the wire diameter can be calculated as the average value of the diameters measured at three or more points using image analysis software after photographing the cross-section of the strand using an optical microscope (100x magnification, using a calibrator).

[0061] In addition, the bubble point pressure of the alkaline water electrolysis membrane of the present invention may be 2 bar or more and 6 bar or less, and preferably 3.0 bar or more, 3.1 bar or more, 3.2 bar or more, 3.3 bar or more, 3.4 bar or more, or 3.5 bar or more, and 5.5 bar or less, 5.4 bar or less, 5.3 bar or less, 5.2 bar or less, 5.1 bar or less, or 5.0 bar or less. When the bubble point pressure of the membrane is maintained within the above range, gas crossover can be prevented due to excellent pore characteristics, stable ion conductivity and electrolyte stability can be secured, and it can lead to increased mechanical strength and durability.

[0062]

[0063] Hereinafter, the present invention will be described in more detail through examples and experimental examples to specifically explain the invention, but the present invention is not limited by these examples and experimental examples. The embodiments according to the present invention may be modified in various different forms, and the scope of the present invention should not be interpreted as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the invention to those with average knowledge in the art.

[0064]

[0065] Example 1

[0066] A slurry containing 40 g of ZrO2 and 7.5 g of a polysulfone polymer binder was double-sidedly coated onto a polyphenylene sulfide mesh with a mesh number of 40 and a wire diameter of 150 μm using a tape casting method. Subsequently, the polymer mesh coated with the slurry was hot-air dried at 90°C for 15 minutes, and the dried polymer substrate was immersed in water, a non-solvent, to form phase separation and pores at 5°C for 10 hours. An alkaline water electrolysis membrane was then prepared through a washing process. The final thickness of the prepared membrane was 500 μm.

[0067]

[0068] Example 2

[0069] In the above Example 1, an alkaline water electrolysis membrane was prepared in the same manner as in Example 1, except that a polyphenylene sulfide mesh with a mesh number of 50 was used.

[0070]

[0071] Example 3

[0072] In the above Example 1, an alkaline water electrolysis membrane was prepared in the same manner as in Example 1, except that a polyphenylene sulfide mesh with a mesh number of 50 was used and the thickness of the final membrane was 400 μm.

[0073]

[0074] Comparative Example 1

[0075] In the above Example 1, an alkaline water electrolysis membrane was prepared in the same manner as in Example 1, except that the thickness of the final membrane was 600 μm.

[0076]

[0077] Comparative Example 2

[0078] In the above Example 1, an alkaline water electrolysis membrane was prepared in the same manner as in Example 1, except that a polyphenylene sulfide mesh with a mesh number of 50 was used and the thickness of the final membrane was 350 μm.

[0079]

[0080] Experimental Example 1: Calculation of Unit Cell Volume Percentage

[0081] The thickness, mesh number, wire diameter, and unit cell length of the membranes prepared in the above examples and comparative examples are shown in Table 1 below. In this case, the thickness of the membrane was calculated as the average of values ​​measured at five points using a contact thickness gauge (Teclock, PG-02). Additionally, the unit cell length was calculated as the average of values ​​measured at three or more points using an optical microscope (100x magnification, using a calibrator). Furthermore, the wire diameter of the mesh strand was calculated as the average of diameter values ​​measured at three or more points using image analysis software after photographing the strand cross-section using the same microscope.

[0082] At this time, the unit cell was defined as a rectangular prism having a height corresponding to the thickness of the membrane, and a square formed by connecting the points where the longitudinal rotation axes of the vertical and horizontal strands intersect when the two horizontal strands and two vertical strands of the polymer mesh support are arranged vertically.

[0083] In addition, the unit cell volume of the membrane prepared in the above examples and comparative examples and the volume of the polymer mesh support included in the unit cell were each calculated, and the volume percentage of the polymer mesh support was calculated from this and shown in Table 2 below.

[0084]

[0085] Membrane Thickness [㎛] Mesh Number Line Diameter [㎛] Unit Cell Length [㎛] Example 1 500 40 150 635 Example 2 500 50 150 508 Example 3 400 50 150 508 Comparative Example 1600 40 150 635 Comparative Example 23 50 50 150 508

[0086]

[0087] Polymer mesh support volume (A) [㎛ 3 ] Unit cell volume (B) [㎛ 3 ] Volume Percentage ((A / B)*100) [%] Example 1 22,442,753 201,612,500 11.13 Example 2 17,954,202 129,032,000 13.91 Example 3 17,954,202 103,225,600 17.39 Comparative Example 1 22,442,753 241,935,000 9.28 Comparative Example 2 17,954,202 90,322,400 19.88

[0088]

[0089] Experimental Example 2: Measurement of bubble point pressure of a membrane

[0090] To comprehensively evaluate the pore characteristics and durability of the membrane, the bubble point pressure of the membranes of the examples and comparative examples was measured by the following method, and the results were summarized in Table 3 below.

[0091]

[0092] [measurement method]

[0093] Bubble point pressure [bar]: After cutting the prepared membrane to fit the diameter of the nitrogen cylinder, the membrane is attached to a measuring cell, water is filled on one side, and a pressure gradually increasing from 0 bar is applied to the other side using nitrogen gas. At this time, the pressure at which the first bubble appears on the opposite side after passing through the membrane is measured as the bubble point pressure.

[0094]

[0095] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Bubble point pressure [bar] 4.0 4.9 3.3 3.0 1.6

[0096]

[0097] As can be seen from Table 3 above, the membranes of Examples 1 to 3 of the present invention all show higher bubble point pressures compared to the comparative example, and in particular, the membrane of Comparative Example 2 shows a significantly lower bubble point pressure because the polymer mesh support is exposed to the surface. From these results, it was found that the membrane of the present invention has excellent pore stability.

[0098]

[0099] Experimental Example 3: Evaluation of Membrane-Applied Cells

[0100] To determine the cell coupling suitability of the membranes manufactured in the above examples and comparative examples, the cell coupling suitability was evaluated using the measurement method described below. In addition, a High Frequency Resistance (HFR) cell evaluation was conducted to objectively verify the internal cell resistance.

[0101]

[0102] [measurement method]

[0103] 1) Evaluation of cell connection suitability

[0104] Effective evaluation area 5*5cm 2Based on [the reference point], the membrane was placed in the center, and the nickel foam electrode was fixed as a load cell. Subsequently, cell evaluation (constant current condition (0.6A / cm²) was performed while maintaining the electrolyte KOH at a temperature of 80℃ and a flow rate of 500mL / min. 2 After maintaining performance until stabilization, IV curve measurement was performed. In addition, the suitability of cell assembly was determined by checking the degree of electrolyte leakage caused by membrane damage (cracks or wrinkles) during cell assembly.

[0105]

[0106] [Judgment Criteria]

[0107] Excellent (◎): No issues with cell evaluation (stable data collection possible during IV curve measurement), excellent appearance without tearing or membrane separation, etc.

[0108] Good (○): No issues with cell evaluation (stable data collection possible during IV curve measurement), partial membrane tearing around the cell connection point during membrane disassembly

[0109] Defective (X): Cell evaluation impossible (data instability during IV curve measurement, short circuit), electrolyte leakage due to membrane damage such as cracks, wrinkles, or folds when the load cell is connected

[0110]

[0111] 2) HFR (High Frequency Resistance) Cell Evaluation

[0112] High Frequency Resistance (HFR) was measured using Electrochemical Impedance Spectroscopy (EIS). The membrane has an effective area of ​​2 x 2 cm². 2After cutting to the desired shape, it was placed between nickel plate electrodes and fixed at a constant pressure using a load cell. A 30 wt% aqueous KOH solution was used as the electrolyte, and the electrolyte was circulated under conditions of 80°C and a flow rate of 500 mL / min. EIS measurements were performed at a constant current density of 1 A / cm². 2 The experiment was conducted in a frequency range from 1 Hz to 1 MHz under the conditions. The acquired impedance data was analyzed using a Nyquist plot, and the resistance value appearing near the real axis on the Nyquist plot was measured as the ionic resistance component (HFR) of the membrane.

[0113]

[0114] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Judgment Result ○◎◎XX Ion Resistance [Ω·cm 2 ]< 0.2< 0.15< 0.15> 0.2> 0.2

[0115]

[0116] As can be seen from Table 4 above, in the case of Examples 1 to 3, which are membranes satisfying the volume characteristics of the present invention, the cell judgment results are all good / excellent, and it can be confirmed that the membrane ion resistance value is lower compared to the comparative example.

[0117] In comparison, Comparative Example 1, in which the volume percentage [%] of the polymer mesh support was less than 11, showed defects such as curling or cracking, and Comparative Example 2, in which the volume percentage [%] of the polymer mesh support was greater than 19, also showed defects such as leakage of KOH and exposure of the polymer mesh support when the cell was connected. In addition, it was confirmed that both Comparative Examples 1 and 2 exhibited high membrane ion resistance, making them unsuitable for application in water electrolysis cells.

[0118] From these results, it was found that the membrane of the present invention has an optimized volume percentage of the mesh support, excellent cell fastening suitability and membrane ion resistance characteristics, and is suitable for application in a water electrolysis system.

Claims

1. Polymer mesh support; and A coating layer formed on the above polymer mesh support and comprising ceramic particles and a polymer binder, and An alkaline water electrolysis membrane having a volume percentage of a polymer mesh support calculated by Formula 1 below of 11% or more and 19% or less. [Equation 1] Volume percentage (%) = (Volume of polymer mesh support contained in unit cell / Volume of unit cell) * 100, In the above Equation 1, the unit cell is a rectangular prism having a height corresponding to the thickness of the membrane, and includes a square formed by connecting the points where the longitudinal rotation axes of the vertical strands and the horizontal strands intersect when two horizontal strands and two vertical strands of the polymer mesh support are arranged vertically.

2. In Claim 1, An alkaline water electrolysis membrane having a volume percentage of the polymer mesh support of 13% or more and 19% or less.

3. In Claim 1, The above-mentioned polymer mesh support comprises one or more selected from the group consisting of polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), polysulfone (PSU), polyether ether ketone (PEEK), polypropylene (PP), polyether sulfone (PES), polyethylene terephthalate (PET), and polyamide (PA), an alkaline water electrolysis membrane.

4. In Claim 1, An alkaline water electrolysis membrane comprising one or more types selected from the group consisting of ZrO2, NiO, Co3O4, TiO2, Fe3O4, CeO2, HfO2, Al2O3, SiO2, and Y2O3, wherein the ceramic particles are an alkaline water electrolysis membrane.

5. In Claim 1, The above-mentioned polymer binder comprises one or more selected from the group consisting of polysulfone (PSU), polyethersulfone (PES), polyphenylsulfone (PPSU), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), and polyethylene oxide (PEO), an alkaline water electrolysis membrane.

6. In Claim 1, Based on the total weight of the alkaline water electrolysis membrane, Ceramic particles of 50 weight% or more and 80 weight% or less, Alkaline water electrolysis membrane containing 10% by weight or more and 20% by weight or less of a polymer binder.

7. In Claim 1, Alkaline water electrolysis membrane having a thickness of 150㎛ or more and 600㎛ or less.

8. In Claim 1, An alkaline water electrolysis membrane having a mesh number calculated as the number of unit cells per inch of 30 or more and 250 or less.

9. In Claim 1, Alkaline water electrolysis membrane having a polymer mesh support with a wire diameter of 30㎛ or more and 180㎛ or less.

10. In Claim 1, An alkaline water electrolysis membrane, wherein the bottom surface of the above unit cell is a square with a side length of 100㎛ or more and 700㎛ or less.

11. In Claim 1, An alkaline water electrolysis membrane having a bubble point pressure of 2 bar or more and 6 bar or less, obtained by measuring the pressure at which bubbles are generated when nitrogen gas is applied to a membrane filled with water while gradually increasing the pressure from 0 bar.

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