Adhesive-fixed water electrolysis module

Abstract

To provide an adhesive-fixed water electrolysis module that enables simplifying product assembly and reducing assembly costs compared to a single stack fixing method using welding, riveting, bolting, etc., between conventional parts.SOLUTION: The present invention is an adhesive-fixed water electrolysis module comprising a single stack 100 having a separator, and a pair of bipolar plates 120a, 120b, a pair of gaskets 130a, 130b, a pair of diffusers 140a, 140b, and a pair of electrodes 150a, 150b, which are sequentially arranged on the cathode and anode sides, respectively, with respect to the separator, forming a symmetrical structure, wherein the separator, the pair of bipolar plates, the pair of gaskets, the pair of diffusers, and the pair of electrodes are stacked in a zero-gap manner in a cell frame 160, and the pair of bipolar plates are adhered and fixed to the cell frame using an adhesive.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an adhesive-fixed alkaline water electrolysis module in which bipolar plates and cell frames are fixed with an adhesive to enable assembly into a single stack. [Background technology]

[0002] Water electrolysis is a technology that produces high-purity (99.999%) green hydrogen by electrolyzing water, and includes alkaline water electrolysis (AWE), polymer electrolyte membrane water electrolysis (PEMWE), and solid oxide electrolyzer cell (SOEC) technologies.

[0003] Of these, alkaline water electrolysis is a technology that uses an alkaline aqueous solution such as KOH or NaOH as an electrolyte to generate hydrogen and oxygen. Alkaline water electrolysis has been researched for the longest time, and its stability and cost competitiveness have been proven, making it a highly mature technology. Specifically, alkaline water electrolysis uses nickel or stainless steel as the catalyst material rather than expensive precious metal catalysts, which means that the initial installation costs are relatively low, the system has a long lifespan, and it is a technology suitable for large-volume hydrogen production.

[0004] The water electrolysis module used in alkaline water electrolysis is a core component of water electrolysis equipment that decomposes supplied water to actually produce hydrogen, and is made by stacking several to several hundred unit components such as anodes, cathodes, and separation membranes. The water electrolysis module is made up of a plurality of stacked single stacks, and each single stack is formed by arranging a hydrogen generating electrode, a diffuser, and a bipolar plate on one side of the separation membrane and an oxygen generating electrode, a diffuser, and a bipolar plate on the other side.

[0005] Conventional alkaline water electrolysis modules are divided into single-cell stacking type and bolted stacking type water electrolysis modules. The single-cell stacking type water electrolysis module is a modified version of an electrolysis device used in a conventional chloro-alkali process, and is configured by connecting a desired number of single cells, each having independent input and output structures for gas, liquid, and current. The bolted stacking type water electrolysis module is configured by stacking a desired number of single cells, each of which is configured by sequentially connecting cell frames provided with end plates, current collector plates, gaskets, mesh-type diffusion layers, electrodes, and separators, and then fixing them with bolts so that the input and output of gas, liquid, and current are connected together.

[0006] The single-cell stacking type water electrolysis module described above can ensure product stability and technical capabilities by converting existing caustic soda production equipment into water electrolysis equipment. However, this single-cell stacking type water electrolysis module has drawbacks, such as individual flow paths formed in each single cell, which increases the size and volume of each cell and increases the number of components. In particular, when stacking tens to hundreds of single cells, single-cell stacking type water electrolysis modules have poorer compatibility between stack components compared to bolt-pressed stacking type water electrolysis modules, resulting in reduced water electrolysis efficiency. Furthermore, while single-cell stacking type water electrolysis modules ensure product stability and technical capabilities, they are large in volume and each single cell has an independent gas / liquid flow path structure, making the product configuration complex and difficult to repair and replace.

[0007] Meanwhile, a bolted stack-type water electrolysis module simplifies the gas and liquid flow paths due to the continuous connection of single cells, reducing internal resistance and ensuring excellent performance. However, a bolted stack-type water electrolysis module has a disadvantage in that the number of parts increases due to the continuous fastening of each part, and incorrect assembly can adversely affect the performance of the entire product and make replacement and repair difficult. In particular, a bolted stack-type water electrolysis module has a disadvantage in that if a part is damaged or its performance deteriorates, the entire stack must be disassembled to replace the part, which requires the water electrolysis system to be shut down for an extended period of time, making on-site repair difficult. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Republic of Korea Patent Publication No. 10-2021-0010231 (2021.01.27.) [Patent Document 2] Republic of Korea Patent Publication No. 10-2003-0090653 (November 28, 2003) [Patent Document 3] Republic of Korea Patent No. 10-1016445 (2011.02.14.) Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an adhesive-fixed water electrolysis module in which the stack can be easily assembled by adhesively fixing the bipolar plates and the cell frames using an adhesive.

[0010] Another object of the present invention is to provide an adhesive-fixed water electrolysis module in which stacks assembled by the adhesive-fixed method are stacked using a zero-gap method, thereby reducing internal resistance and simplifying internal components, and enabling flexible adaptation to a variety of capacities. [Means for solving the problem]

[0011] To achieve the above object, an adhesive-type water electrolysis module according to the present invention includes a single stack including a separation membrane, bipolar plates sequentially arranged on a cathode side and an anode side of the separation membrane and symmetrically disposed with respect to each other, a gasket, a diffuser, and an electrode, wherein the separation membrane, a pair of bipolar plates, a pair of gaskets, a pair of diffusers, and a pair of electrodes are stacked in a cell frame in a zero-gap manner, and the pair of bipolar plates are adhesively fixed to the cell frame using an adhesive.

[0012] Preferably, adhesive application lines are formed on the edge portions of both sides of the cell frame, and the pair of bipolar plates are adhesively fixed to the cell frame by the adhesive applied to the adhesive application lines.

[0013] More preferably, the adhesive is heat-resistant and alkali-resistant, and is a thermoplastic, room-temperature-setting, two-component, or one-component adhesive.

[0014] More preferably, the depth of the adhesive application line on the cell frame is determined by the viscosity of the adhesive and is 0.5 to 2 times the thickness of the gasket, and the width of the adhesive application line on the cell frame is determined by the viscosity of the adhesive and is 0.5 to 2 times the depth of the adhesive application line.

[0015] Additionally, the present invention further includes a physical fastening means for fastening the cell frame and the bipolar plate, the physical fastening means including a first fastening portion protruding from an outer edge of the cell frame and a second fastening portion formed on an outer edge of the bipolar plate and fastened to the first fastening portion, and the first fastening portion and the second fastening portion are engaged with each other by a snap fit.

[0016] Preferably, the second fastening part includes a bent part that is bent from the outer edge of the bipolar plate toward the cell frame and wraps around the outer edge of the cell frame, and a groove part that is formed by cutting open a center part of the bent part and into which the first fastening part is fitted, and the first fastening part has a hook shape with its end protruding outward and is fitted into the groove part of the second fastening part by a snap fit method.

[0017] Preferably, the cell frame includes, at a central portion thereof, a receiving portion for receiving the separator, the pair of gaskets, the pair of diffusers, and the pair of electrodes, and an outer portion thereof includes a gas passage for discharging hydrogen and oxygen and an electrolyte passage for inflow and discharge of electrolyte, the bipolar plate includes a gas passage and an electrolyte passage corresponding to the gas passage and the electrolyte passage of the cell frame, and a plurality of the single stacks are connected by a bolting method or a hydraulic press method to form a water electrolysis module.

[0018] More preferably, the cell frame includes a gasket leakage prevention protrusion having protrusions arranged in two or three layers to surround the gas flow path and the electrolyte flow path, and the gasket has two or three protrusions that fit between the protrusions of the gasket leakage prevention protrusion, and when the single stack is crimped, the gasket is crimped to the cell frame in a snap-fit ​​manner. [Effects of the Invention]

[0019] According to the present invention, a stack is formed by fixing a cell frame and a pair of bipolar plates with an adhesive, which simplifies product assembly and reduces assembly costs compared to conventional stack fixing methods that use welding, riveting, bolting, etc. between parts.

[0020] Furthermore, according to the present invention, the cell frame and the bipolar plates are first fixed to each other with an adhesive and then joined together by a physical fastening means, thereby assembling the stack more firmly. Furthermore, the physical fastening means fixes the stack components in precise positions without any steps, thereby preventing a decrease in the efficiency of the water electrolysis module. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is an exploded perspective view showing a single stack of adhesive fixed type water electrolysis modules according to the present invention. [Figure 2] FIG. 2 is a front view showing a cell frame of a single stack of the adhesive fixed type water electrolysis module according to the present invention. [Figure 3] 1 is a perspective view showing a physical fastening means of an adhesive fixed type water electrolysis module according to the present invention, illustrating a state in which a cell frame and a bipolar plate are fastened together; DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, preferred embodiments of an adhesive-type water electrolysis module according to the present invention will be described with reference to the accompanying drawings. For reference, in the following description of the present invention, terms referring to components of the present invention are named in consideration of the functions of each component, and should not be construed as limiting the technical components of the present invention.

[0023] 1 and 2, an adhesive fixed type water electrolysis module according to the present invention includes at least one or more single stacks 100. Each single stack 100 includes a separator 110, bipolar plates 120a, 120b, gaskets 130a, 130b, diffusers 140a, 140b, and electrodes 150a, 150b, which are sequentially arranged on the cathode and anode sides of the separator 110, respectively. The bipolar plates 120a, 120b, gaskets 130a, 130b, diffusers 140a, 140b, and electrodes 150a, 150b are arranged symmetrically with respect to each other with respect to the separator 110.

[0024] Specifically, the single stack 100 is constructed by fastening a pair of bipolar plates 120a, 120b to a cell frame 160 so that stack components, i.e., a separator 110, a pair of electrodes 150a, 150b, a pair of diffusers 140a, 140b, and a pair of gaskets 130a, 130b, are housed within the cell frame 160. That is, within the cell frame 160, the cathode bipolar plate 120a, gasket 130a, diffuser 140a, and electrode 150a and the anode bipolar plate 120b, gasket 130b, diffuser 140b, and electrode 150b are stacked symmetrically with respect to each other, with the separator 110 at the center.

[0025] The cell frame 160 is made of a material that is resistant to corrosion in strong alkalis, such as PS (Polystyrene), PESU (Polyethersulfone), PP (Polypropylene), PPSU (Polyphenylsulfone), PTFE (Polytetrafluoroethylene), or stainless steel. The cell frame 160 has an anode chamber and a cathode chamber separately configured, and includes gas flow paths 161 and 162 for discharging hydrogen and oxygen, and electrolyte flow paths 163 and 164 for inflow and outflow of electrolyte. Here, the cell frame 160 may be stacked between a pair of cell frame supports (not shown).

[0026] The bipolar plates 120a and 120b are metal plates disposed on the outermost sides of the single stack 100, functioning as bus bars that apply external current to the internal electrodes 150a and 150b, and also serve to establish electrical connection between the stacked single stacks 100. The bipolar plates 120a and 120b have gas channels for discharging hydrogen and oxygen, and electrolyte channels for the inflow and outflow of electrolyte.

[0027] The gaskets 130a and 130b are inserted between the bipolar plates 120a and 120b and the cell frame 160 to prevent leakage between the components constituting the single stack 100. The gaskets 130a and 130b are made of a material that is resistant to corrosion by strong alkalis, such as EPDM (Ethylene Propylene Diene M-Class Rubber), fluorine-based rubber, or PTFE (Polytetrafluoroethylene). The gaskets 130a and 130b are formed with double protrusions to provide airtightness between the stacked components, preventing leakage of liquid or gas between the components.

[0028] The diffusers 140a and 140b are disposed on the surfaces of the electrodes 150a and 150b facing the bipolar plates 120a and 120b, and serve to uniformly diffuse the fluid supplied to the cathode electrode 150a and the anode electrode 150b from the separator 110. The diffusers 140a and 140b are porous bodies manufactured in a mesh, knit, or foam shape, and have pore sizes of 10 μm to 10 mm and thicknesses of 0.1 mm to 20 mm, for example.

[0029] The electrodes 150a and 150b are disposed between the separator 110 and the diffusers 140a and 150b. The electrodes 150a and 150b are mainly made of transition metals such as Ni, Fe, Co, and Mo, and can be manufactured by coating, plasma coating, or plating a mixed oxide of these transition metals on a porous metal body.

[0030] The separator 110 is laminated between a pair of electrodes 150a and 150b. The separator 110 is a porous composite with ceramic particles dispersed therein to ensure durability in a strong alkaline environment. For example, the separator 110 can be manufactured by spraying a zirconium mixture onto a PPS (Polyphenylene sulfide) or PPSU (Polyphenylsulfone) polymer matrix support.

[0031] Additionally, the separation membrane 110 is fixed inside a separation membrane fixing frame 111 , and a separation membrane gasket 112 for preventing leakage around the separation membrane 110 is disposed between the separation membrane fixing frame 111 and the separation membrane 110 .

[0032] The cell frame 160 has a central portion formed with a receiving portion 165 for stacking the separator 110, the pair of gaskets 130a and 130b, the pair of diffusers 140a and 140b, and the pair of electrodes 150a and 150b. The outer periphery of the cell frame 165 has flow paths 161 and 162 for discharging hydrogen and oxygen, and flow paths 163 and 164 for inflow and discharge of electrolyte. The cell frame 160 also has adhesive application lines 170 formed on its both side edges. An adhesive is applied to the adhesive application lines 170, and bipolar plates 120a and 120b are fixed to both side surfaces of the cell frame 160 by adhesive, respectively.

[0033] That is, the separator 110, a pair of gaskets 130a and 130b, a pair of diffusers 140a and 140b, and a pair of electrodes 150a and 150b are accommodated and stacked inside the cell frame 160, and bipolar plates 120a and 120b are respectively adhered and fixed to both sides of the cell frame 160 with an adhesive to form a single stack 100. In particular, the pair of bipolar plates 120a and 120b, the separator 110 stacked inside the cell frame 160, the gaskets 130a and 130b, the diffusers 140a and 140b, and the electrodes 150a and 150b are stacked in a zero-gap manner, which allows for smooth current connection and reduces current loss due to low resistance.

[0034] As described above, the adhesive-type water electrolysis module according to the present invention does not require bonding or fastening other stack components (separator, gasket, diffuser, and electrodes), and can assemble a single stack 100 by adhesively fixing only the cell frame 160 and the pair of bipolar electrodes 120a, 120b. This simplifies product assembly and reduces assembly costs compared to conventional water electrolysis stacks that use fixing methods such as welding, riveting, and bolting between components.

[0035] Preferably, the adhesive has heat resistance and alkali resistance, and a thermoplastic, room temperature curing, two-component, or one-component adhesive can be used. For example, the adhesive used is an adhesive that is resistant to high heat (up to 100°C or higher) and strong alkalinity generated during water electrolysis operation.

[0036] The depth of the adhesive application line 170 formed on the cell frame 160 is determined by the viscosity of the adhesive and is designed to be 0.5 to 2 times the thickness of the gaskets 130a and 130b. The width of the adhesive application line 170 is determined by the viscosity of the adhesive and is designed to be 0.5 to 2 times the depth of the adhesive application line.

[0037] Preferably, the adhesive fixed type water electrolysis module according to the present invention can be configured to accommodate various capacities by stacking a desired number of single stacks 100 by bolting or hydraulic pressing in accordance with the water electrolysis operating capacity.

[0038] Although not shown in the drawings, when connecting the single stacks 100 by a bolt clamping method, a water electrolysis module can be constructed by stacking a desired number of single stacks in accordance with the water electrolysis operating capacity on a stacking frame and connecting the single stacks by a bolt clamping method using bolts and insert nuts.

[0039] In addition, when connecting the single stacks 100 using a hydraulic press, a desired number of single stacks may be stacked on a stacking frame according to the water electrolysis operating capacity, and the stacked single stacks may be pressurized and fixed using a hydraulic press.

[0040] Meanwhile, the cell frame 160 includes a gasket leakage prevention projection 180 having projections arranged in two or three layers so as to surround the periphery of the gas flow paths 161, 162 and the electrolyte flow paths 163, 164. In addition, the gaskets 130a, 130b described above have two or three projections that fit between the projections of the gasket leakage prevention projection 180.

[0041] When assembling a single stack 100, the stack components are compressed by the gaskets 130a, 130b and the gasket leakage prevention protrusions 180, and the gaskets 130a, 130b and the cell frame 160 are compressed in a snap-fit ​​manner.

[0042] Preferably, the protrusions of the gaskets 130a, 130b or the gasket leakage prevention protrusions 180 may have a triangular shape that is symmetrical to each other in the vertical direction, and when a single stack 100 is crimped, they spread apart from each other to prevent leakage of flowing gases and fluids.

[0043] 3, the adhesive fixed type water electrolysis module according to the present invention includes a physical fastening means for physically fastening the pair of bipolar plates 120a, 120b to the cell frame 60.

[0044] Specifically, the physical fastening means includes a first fastening portion 210 provided on the outer edge portion of the cell frame 160 and a second fastening portion 220 provided on the outer edge portion of the bipolar plates 120a and 120b and fastened to the first fastening portion 210. The first fastening portion 210 has a protruding shape that protrudes from the outer edge portion of the cell frame 160. The second fastening portion 220 is bent from the outer edge portion of the bipolar plates 120a and 120b toward the cell frame 160 and includes a bent portion 221 that encloses the outer edge portion of the cell frame 160, and a groove 222 that is cut in the center of the bent portion 221 and into which the first fastening portion 210 is fitted. Here, the first fastening portion 210 and the second fastening portion 220 are fitted together using a snap fit method.

[0045] Preferably, the cell frame 160 has a pair of first fastening portions 210 arranged adjacent to each other in the vertical direction on one side of the outer edge portion. One of the pair of first fastening portions 210 is fitted into the groove 222 of the second fastening portion 220 of one bipolar plate 120a of the pair of bipolar plates 120a, 120b, and the other of the pair of first fastening portions 210 is fitted into the groove 222 of the second fastening portion 220 of the other bipolar plate 120b of the pair of bipolar plates 120a, 120b. In addition, the first fastening portion 210 of the cell frame 160 has a hook shape with an outward protruding end so as to be firmly fitted into the groove 222 of the second fastening portion 220. With this configuration, when the first fastening portion 210 of the cell frame 160 is engaged with the groove portion 222 of the second fastening portion 220 of the bipolar plates 120a and 120b to be coupled, the first fastening portion 210 slides on the bent portion 221 of the second fastening portion 210 and is engaged with the groove portion 222 of the second fastening portion 220 in a snap-fit ​​manner.

[0046] In addition, a pair of adjacent first fastening portions 210 are respectively disposed on four side surfaces of the outer edge of the cell frame 160. Corresponding to the first fastening portions 210, second fastening portions 220 are similarly disposed on four side surfaces of the outer edge of the bipolar plates 120a, 120b.

[0047] As described above, in the adhesive-type water electrolysis module according to the present invention, the cell frame 160 and the bipolar plates 120a, 120b are first fixed with an adhesive and then additionally joined by a physical fastening means, thereby assembling the cell frame 160 and the bipolar plates 120a, 120b of the single stack 100 more firmly and stably.

[0048] The above-described embodiments of the present invention are merely illustrative of the technical idea of ​​the present invention, and the scope of protection of the present invention should be interpreted by the following claims. Furthermore, a person skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention, and all technical ideas within the scope equivalent to the present invention should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0049] 100 Single stack 110 Separation membrane 111 Separation membrane fixing frame 112 Separation membrane gasket 120a, 120b Bipolar plate 130a, 130b Gasket 140a, 140b Diffuser 150a, 150b Electrode 160 Cell frame 161, 162 Gas flow path 163, 164 Electrolyte flow path 165 Receptacle 170 Adhesive application line 180 Gasket leakage prevention protrusion 210 First fastening portion 220 Second fastening portion 221 Bent portion 222 Groove portion

Claims

1. The fuel cell includes a single stack including a separator, bipolar plates, a gasket, a diffuser, and an electrode, which are sequentially arranged on a cathode side and an anode side of the separator, respectively, and are symmetrical to each other, and The separation membrane, the pair of bipolar plates, the pair of gaskets, the pair of diffusers, and the pair of electrodes are stacked in a cell frame in a zero-gap manner, The adhesive-fixed water electrolysis module, wherein the pair of bipolar plates are adhesively fixed to the cell frame using an adhesive.

2. 2. The adhesive-type water electrolysis module according to claim 1, wherein an adhesive application line is formed on each edge portion of each side surface of the cell frame, and the pair of bipolar plates are adhesively fixed to the cell frame by the adhesive applied along the adhesive application line.

3. 3. The adhesive-fixed water electrolysis module according to claim 2, wherein the adhesive is heat-resistant and alkali-resistant, and is a thermoplastic, room-temperature-setting, two-component, or one-component adhesive.

4. The depth of the adhesive application line on the cell frame is determined by the viscosity of the adhesive and is 0.5 to 2 times the thickness of the gasket; 4. The adhesive-fixed water electrolysis module according to claim 3, wherein a width of the adhesive application line on the cell frame is determined depending on the viscosity of the adhesive and is 0.5 to 2 times the depth of the adhesive application line.

5. further comprising physical fastening means for fastening the cell frame and the bipolar plate; the physical fastening means includes a first fastening portion protruding from an outer edge of the cell frame and a second fastening portion formed on an outer edge of the bipolar plate and fastened to the first fastening portion; The adhesive-type water electrolysis module according to claim 2 , wherein the first fastening portion and the second fastening portion are engaged with each other by a snap fit.

6. the second fastening portion includes a bent portion that is bent from an outer edge of the bipolar plate toward the cell frame and wraps around the outer edge of the cell frame, and a groove that is formed by cutting a center portion of the bent portion and into which the first fastening portion is fitted, 6. The adhesive-type water electrolysis module according to claim 5, wherein the first fastening portion has a hook-like end protruding outward and is fitted into the groove of the second fastening portion by a snap-fit ​​method.

7. the cell frame has a housing portion in a central portion in which the separation membrane, the pair of gaskets, the pair of diffusers, and the pair of electrodes are housed, and has a gas flow path for discharging hydrogen and oxygen and an electrolyte flow path for inflow and discharge of electrolyte in an outer shell portion; the bipolar plate has gas channels and electrolyte channels corresponding to the gas channels and electrolyte channels of the cell frame; The adhesive-type water electrolysis module according to claim 1 , wherein a plurality of the single stacks are connected by a bolt clamping method or a hydraulic press method to form a water electrolysis module.

8. the cell frame includes a gasket leakage prevention protrusion having protrusions arranged in two or three layers so as to surround the periphery of the gas flow path and the electrolyte flow path; 8. The adhesive-type water electrolysis module according to claim 7, wherein the gasket has double or triple protrusions that are fitted between protrusions of the gasket leakage prevention protrusions, and the gasket is crimped to the cell frame in a snap-fit ​​manner when the single stack is crimped.

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