electrolyzer

Abstract

The present invention relates to an electrolyzer, and the electrolyzer according to the present invention includes a plurality of separator plates and a membrane-electrode assembly positioned between the plurality of separator plates, the membrane-electrode assembly including a plurality of electrodes and a separator membrane positioned between the plurality of electrodes. The separator plates include a first flow path portion having alternating reliefs and recesses in an active area on one side to form a first flow path, and a second flow path portion having alternating reliefs and recesses in an active area on the other side to form a second flow path, the second flow path being formed by alternating reliefs and recesses corresponding to the reliefs and recesses in the first flow path portion.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0161754 filed November 28, 2022 and Korean Patent Application No. 10-2023-0166825 filed November 27, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to an electrolyzer. [Background technology]

[0003] Currently, carbon dioxide is a greenhouse gas that causes global warming and must be reduced. Methods for reducing carbon dioxide include capture, chemical conversion, and electrochemical conversion. Among these, electrochemical conversion allows precise control of the components so that other synthetic gases can be produced, and is more economically advantageous than simply removing carbon dioxide.

[0004] Among water electrolysis systems that electrochemically convert carbon dioxide or split water to produce hydrogen, membrane-electrode assembly (MEA)-based systems are particularly being actively researched because they can operate under high current density conditions, are highly energy efficient, and are easy to stack and modularize.

[0005] The unit cell of a membrane electrode assembly system is composed of an anode and a cathode positioned around a separation membrane, and a separator plate with a flow path that supplies electrical energy and reactants to the anode and cathode electrodes and discharges the products. A stack is manufactured by stacking unit cells. In a membrane electrode assembly system, if the separator plates on the anode and cathode sides are manufactured and joined separately, the manufacturing costs of the separator plates increase and, most importantly, resistance occurs at the joining interface, resulting in lower energy efficiency. Summary of the Invention [Problem to be solved by the invention]

[0006] One aspect of the present invention is to provide an electrolyzer that can reduce manufacturing costs and increase energy efficiency. [Means for solving the problem]

[0007] An electrolyzer according to an embodiment of the present invention includes a plurality of separator plates and a membrane-electrode assembly positioned between the plurality of separator plates, the membrane-electrode assembly including a plurality of electrodes and a separator membrane positioned between the plurality of electrodes, wherein the separator plates include a first flow path portion having an active area on one side thereof on which reliefs and intaglios are alternately formed to form a first flow path, and a second flow path portion having an active area on the other side thereof on which intaglios and intaglios are alternately formed to form a second flow path, corresponding to the reliefs and intaglios formed in the first flow path portion. [Effects of the Invention]

[0008] According to the present invention, in an electrolysis device for electrolyzing carbon dioxide, the separator plates facing the anode and cathode electrodes of a membrane-electrode assembly are formed into a single plate by forming reliefs and depressions, thereby reducing manufacturing costs and improving energy efficiency.

[0009] In addition, the multiple separators are stacked with one side and the other side inverted relative to each other in the stacking direction, sandwiching the membrane-electrode assembly therebetween, thereby preventing the flow paths of the separators stacked at the top from being blocked by the separators stacked at the bottom.

[0010] Furthermore, by forming the first gasket and the second gasket arranged on one side and the other side of the separation plate to have different thicknesses, it is possible to more effectively maintain airtightness. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an exploded perspective view illustrating an electrolyzer according to an embodiment of the present invention; [Figure 2] 2 is a cross-sectional view taken along line AA' in FIG. 1. FIG. [Figure 3] FIG. 3 is an enlarged cross-sectional view of region B in FIG. 2. [Figure 4] 3 is a plan view illustrating one surface of a separator plate in an electrolyzer according to an embodiment of the present invention; FIG. [Figure 5] 4 is a plan view illustrating another surface of a separator plate in an electrolyzer according to an embodiment of the present invention; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] The objectives, particular advantages, and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. It should be noted that, when referring to components in each drawing, the same components will have the same numbers as much as possible even if they appear in different drawings. The present invention may be realized in various different forms and is not limited to the embodiments described herein. In describing the present invention, detailed descriptions of related known technologies that may obscure the gist of the present invention will be omitted.

[0013] FIG. 1 is an exploded perspective view illustrating an electrolyzer according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A' in FIG. 1, and FIG. 3 is an enlarged cross-sectional view of region B in FIG. 2.

[0014] 1 to 5, an electrolyzer 100 according to an embodiment of the present invention includes a plurality of separator plates 110, 120, 130, and 140, and a membrane-electrode assembly 210 positioned between the separator plates 110, 120, 130, and 140 and including a plurality of electrodes 213 and a separator membrane 214. The separator plates 110, 120, 130, and 140 have an active area A1 on one surface 110a, 120a, 130a, and 140a, respectively, and have a embossed pattern 111. The active area A2 of the other surfaces 110b, 120b, 130b, 140b may include first flow path portions 111, 121 in which the reliefs 111a, 121a and the reliefs 111b, 121b are alternately formed, and second flow path portions 112, 122 in which the reliefs 112b, 122b and the reliefs 112a, 122a are alternately formed corresponding to the reliefs 111a, 121a and the reliefs 111b, 121b formed in the first flow path portions 111, 121. The electrolyzer 100 according to the embodiment of the present invention may further include a first gasket 311 and a second gasket 312.

[0015] More specifically, the electrolyzer 100 according to the embodiment can electrolyze carbon dioxide (CO2) by causing an electrochemical reduction reaction of carbon dioxide (CO2).

[0016] The electrolyzer 100 may include a number of separator plates 110 , 120 , 130 , 140 and a membrane-electrode assembly 210 positioned between the number of separator plates 110 , 120 , 130 , 140 .

[0017] The separators 110, 120, 130, 140 and the membrane-electrode assemblies 210 are stacked alternately, and in this case, the separators 110, 140 may be located at the top and bottom in the stacking direction S.

[0018] The membrane-electrode assembly 210 is positioned between a number of separator plates 110 , 120 , 130 , and 140 , and may include a plurality of electrodes 213 and separator membranes 214 positioned between the plurality of electrodes 213 .

[0019] The electrodes 213 include anodes 211 and cathodes 212, and the anodes 211 and cathodes 212 can be alternately positioned in the stacking direction S.

[0020] The separation membrane 214 is made of an insulating ion exchange membrane (IEM), and allows ions to move between the anode 211 and the cathode 212.

[0021] In addition, the membrane-electrode assembly 210 can cause an electrochemical reduction reaction, for example, by electrolyzing carbon dioxide (CO2) into carbon monoxide (CO) or ethylene (C2H4).

[0022] FIG. 4 is a plan view illustrating one side of a separator plate in an electrolyzer according to an embodiment of the present invention, and FIG. 5 is a plan view illustrating the other side of a separator plate in an electrolyzer according to an embodiment of the present invention.

[0023] 1 to 5, the separation plates 110, 120, 130, and 140 include first flow path portions 111 and 121 in which reliefs 111a and 121a and recesses 111b and 121b are alternately formed in an active area A1 of one surface 110a, 120a, 130a, and 140a, forming a first flow path P1, and second flow path portions 112 and 122 in which recesses 112b and 122b and reliefs 112a and 122a are alternately formed in an active area A2 of the other surface 110b, 120b, 130b, and 140b, corresponding to the reliefs 111a and 121a and recesses 111b and 121b formed in the first flow path portions 111 and 121, forming a second flow path P2.

[0024] The first flow path sections 111 and 121 face the electrode 213, and a first flow path P1 through which the raw fluid flows opens toward the electrode 213, while the second flow path sections 112 and 122 face the electrode 213, and a second flow path P2 through which the raw fluid flows opens toward the electrode 213. Here, the raw fluid may contain, for example, carbon dioxide (CO2) and an electrolyte. Here, the electrolyte may contain water (H2O).

[0025] On one surface 110a, 120a, 130a, 140a of the separation plates 110, 120, 130, 140, the reliefs 111a, 121a of the first flow path portions 111, 121 formed in the active region A1 are formed to protrude toward the inactive region B1, and the reliefs 112b, 122b of the second flow path portions 112, 122 formed in the active region A2 of the other surfaces 110b, 120b, 130b, 140b of the separation plates 110, 120, 130, 140 may be formed to be recessed toward the inactive region B2.

[0026] The first flow path P1 may be formed in the recesses 111b and 121b of the first flow path portions 111 and 121, and the second flow path P2 may be formed in the recesses 112b and 122b of the second flow path portions 112 and 122.

[0027] The first flow path P1 and the second flow path P2 may be parallel. Here, for example, the reliefs 111a, 121a, 112a, 122a and the recesses 111b, 121b, 112b, 122b formed in the first flow path portions 111, 121 and the second flow path portions 112, 122 of the separation plates 110, 120, 130, 140 may be formed along the width direction W of the separation plates 110, 120, 130, 140, and the first flow path P1 and the second flow path P2 may be formed along the length direction L of the second gaskets of the separation plates 110, 120, 130, 140.

[0028] Meanwhile, the reliefs 111a, 121a, 112a, 122a and recesses 111b, 121b, 112b, 122b formed in the first flow path portions 111, 121 and the second flow path portions 112, 122 may be formed in a rectangular shape.

[0029] Furthermore, the width W1 of the recesses 111b, 121b formed in the first flow path portions 111, 121 and the width W2 of the recesses 112b, 122b formed in the second flow path portions 112, 122 may be 100 to 5000 μm. Therefore, the width W1 of the recesses 111b, 121b formed in the first flow path portions 111, 121 and the width W2 of the recesses 112b, 122b formed in the second flow path portions 112, 122 are formed to be greater than 100 μm, thereby significantly reducing the pressure within the separator plates 110, 120, 130, 140 during fluid flow. Furthermore, the width W1 of the recesses 111b, 121b formed in the first flow path portions 111, 121 and the width W2 of the recesses 112b, 122b formed in the second flow path portions 112, 122 are formed to be smaller than 5000 μm, thereby significantly reducing electrical resistance. That is, if the widths W1 and W2 of the recesses 112b and 122b of the first flow path portions 111 and 121 and the second flow path portions 112 and 122 are too large, the contact area between the electrode 213 and the separator plates 110, 120, 130 and 140 will be reduced accordingly, resulting in an increase in electrical resistance. However, if the widths W1 and W2 of the recesses 111b, 121b, 112b and 122b are formed to be smaller than 5000 μm, the problem of increased electrical resistance can be significantly reduced.

[0030] The width W1 of the recesses 111b, 121b of the first flow path sections 111, 121 and the width W2 of the recesses 112b, 122b of the second flow path sections 112, 122 may be the same. This has the effect of ensuring reaction uniformity. That is, if the width W1 of the recesses 111b, 121b of the first flow path sections 111, 121 and the width W2 of the recesses 112b, 122b of the second flow path sections 112, 122 are the same, the width over which the reaction fluids in the first flow path P1 and the second flow path P2 formed in the recesses 111b, 121b of the first flow path sections 111, 121 and the recesses 112b, 122b of the second flow path sections 112, 122 contact the electrode 213 becomes uniform, thereby enabling the reaction to occur uniformly.

[0031] Meanwhile, the plurality of separators 110, 120, 130, 140 may be stacked in the stacking direction S with the membrane-electrode assembly 210 sandwiched therebetween such that one surface 110a, 120a, 130a, 140a and the other surface 110b, 120b, 130b, 140b are inverted to each other.

[0032] Here, for example, when the separator plates 110, 120, 130, and 140 are inverted, the embossment 111a of the first flow path portion 111 of the separator plate 110 positioned at the top in the stacking direction S may be positioned to face the embossment 121a of the first flow path portion 121 of the separator plate 120 positioned at the bottom in the stacking direction S, between the membrane-electrode assembly 210. As a result, when stacked, the embossment 111b of the first flow path portion 111 of the separator plate 110 positioned at the top and the embossment 122a of the second flow path portion 122 of the separator plate 120 positioned at the bottom are inserted together with the membrane-electrode assembly 210, preventing the first flow path P1 formed in the embossment 111b of the first flow path portion 111 of the separator plate 120 positioned at the top from being blocked.

[0033] The active area A1 of one surface 110a, 120a, 130a, 140a of the separation plate 110, 120, 130, 140 may further include a first distributor 113 through which fluid flows in and out of the first flow path. The active area A2 of the other surface 110b, 120b, 130b, 140b of the separation plate 110, 120, 130, 140 may include a second distributor 114 through which fluid flows in and out of the second flow path P2.

[0034] Meanwhile, the thickness d of the separation plates 110, 120, 130, and 140 may be formed to be 50 to 500 μm. Therefore, the thickness d of the separation plates 110, 120, 130, and 140 is greater than 50 μm, which can prevent distortion during processing of the separation plates 110, 120, 130, and 140. In addition, the thickness d of the separation plates 110, 120, 130, and 140 is less than 500 μm, which can allow the width W2 of the recesses 111b, 121b, 112b, and 122b formed in the first flow path portions 111 and 121 and the second flow path portions 112 and 122 of the separation plates 110, 120, 130, and 140 to be 100 μm or more. That is, if the thickness d of the separation plates 110, 120, 130, 140 is formed to be 500 μm or more, the thickness d of the separation plates 110, 120, 130, 140 is too thick, and there is a problem that the width W2 of the depressions 111b, 121b, 112b, 122b of the first flow path portions 111, 121 and the second flow path portions 112, 122 cannot be formed to be 100 μm or more when the separation plates 110, 120, 130, 140 are manufactured. Therefore, if the thickness d of the separation plates 110, 120, 130, 140 is formed to be less than 500 μm, the widths W1 and W2 of the recesses 111b, 121b, 112b, 122b of the first flow path portions 111, 121 and the second flow path portions 112, 122 can be formed to be 100 μm or more, which is the width W1 and W2 that can significantly relieve the pressure within the separation plates 110, 120, 130, 140 while the fluid is flowing.

[0035] The first gasket 311 can be arranged in the inactive area B1 of one surface 110a, 120a, 130a, 140a of the separator plate 110, 120, 130, 140, and the second gasket 312 can be arranged in the inactive area B2 of the other surface 110b, 120b, 130b, 140b of the separator plate 110, 120, 130, 140.

[0036] In addition, the first gasket 311 and the second gasket 312 may be formed to have different thicknesses g1, g2 in the stacking direction S. Thus, the thickness g1 of the first gasket 311 and the thickness g2 of the second gasket 312 disposed on one surface 110a, 120a, 130a, 140a and the other surface 110b, 120b, 130b, 140b of the separator plates 110, 120, 130, 140 may be formed to be different in accordance with the height h of the embossments 111a, 121a, 112a, 122a and the indentations 111b, 121b, 112b, 122b formed on the separator plates 110, 120, 130, 140 and the thickness t1, t2 of the electrode 213, thereby more effectively maintaining airtightness.

[0037] The first gasket 311 and the second gasket 312 can be positioned on the same line in the stacking direction S.

[0038] The thickness g1 of the first gasket 311 may be formed to be the same as the sum of the thickness t2 of the electrode 213 facing one surface 110a, 120a, 130a, 140a of the separator 110, 120, 130, 140 in the plurality of electrodes 213 and the protruding height h of the embossments 111a, 121a formed on one surface 110a, 120a, 130a, 140a of the separator 110, 120, 130, 140. Here, the thickness g2 of the second gasket 312 may be formed to be the same as the thickness t1 of the electrode 213 facing the other surface 110b, 120b, 130b, 140b of the separator 110, 120, 130, 140 in the plurality of electrodes 213.

[0039] In addition, the first gasket 311 is provided along the edge of the active area A1 on one side 110a, 120a, 130a, 140a of the separator 110, 120, 130, 140 to maintain airtightness of the active area A1 on one side 110a, 120a, 130a, 140a, and the second gasket 312 is provided along the edge of the active area A2 on the other side 110b, 120b, 130b, 140b of the separator 110, 120, 130, 140 to maintain airtightness of the active area A2 on the other side 110b, 120b, 130b, 140b of the separator 110, 120, 130, 140.

[0040] Meanwhile, the electrolyzer 100 according to an embodiment of the present invention may further include a first-side peripheral gasket 411 provided along the periphery of one surface 110a, 120a, 130a, 140a of the separator plates 110, 120, 130, 140, and an second-side peripheral gasket 511 provided along the periphery of the second surface 110b, 120b, 130b, 140b of the separator plates 110, 120, 130, 140. Here, the thickness of the first-side peripheral gasket 411 in the stacking direction S may correspond to the thickness g1 of the first gasket 311, and the thickness of the second-side peripheral gasket 511 in the stacking direction S may correspond to the thickness g2 of the second gasket 312.

[0041] In addition, the electrolyzer 100 according to the embodiment of the present invention may further include branch gaskets 412 and 512 that are provided with the first and second distribution portions 113 and 114 of the separation plates 110, 120, 130, and 140 and branch the flow paths.

[0042] In the electrolyzer 100 according to an embodiment of the present invention configured as described above, the separators 110, 120, 130, 140 facing the anode 211 and the electrode 213 of the cathode 212 of the membrane-electrode assembly 210 are formed with embossments 111a, 121a, 112a, 122a and recesses 111b, 121b, 112b, 122b, respectively, thereby reducing manufacturing costs and improving energy efficiency. That is, when electrochemically converting carbon dioxide or splitting water to produce hydrogen, an aqueous solution-based electrolyte is supplied to the anode 211, eliminating the need for a separate cooling water supply. Therefore, the separators 110, 120, 130, 140 may be formed with embossments 111a, 121a, 112a, 122a and recesses 111b, 121b, 112b, 122b to form flow paths between the anode 211 and the cathode 212. As a result, by using one separator 110, 120, 130, 140 instead of two separators, manufacturing costs can be reduced, and the interface resistance that occurs when two separators are used is not generated, resulting in increased energy efficiency due to the reduced resistance.

[0043] In addition, the multiple separators 110, 120, 130, 140 are stacked in the stacking direction S with the membrane-electrode assembly 210 sandwiched between them, such that one side 110a, 120a, 130a, 140a and the other side 110b, 120b, 130b, 140b are inverted relative to each other. This prevents the reliefs 111a, 121a, 112a, 122a of the separators 120, 130, 140 stacked at the bottom in the stacking direction S from blocking the flow paths formed in the recesses 111b, 121b, 112b, 122b of the separators 110, 120, 130 stacked at the top in the stacking direction S.

[0044] Furthermore, the first gaskets 311 and second gaskets 312 disposed on one side 110a, 120a, 130a, 140a and the other side 110b, 120b, 130b, 140b of the separator plates 110, 120, 130, 140 are formed to have different thicknesses g1, g2 in accordance with the height h of the embossments 111a, 121a, 112a, 122a and the recesses 111b, 121b, 112b, 122b formed on the separator plates 110, 120, 130, 140 and the thickness t1, t2 of the electrode 213, thereby more effectively maintaining airtightness.

[0045] Although the present invention has been described in detail above with reference to specific embodiments, these are merely for the purpose of specifically describing the present invention, and the post-processing device according to the present invention is not limited thereto. It can be said that various implementations are possible within the technical concept of the present invention by those skilled in the art.

[0046] The specific scope of protection of the invention will be defined by the appended claims. [Explanation of symbols]

[0047] 100 Electrolyzer 110, 120, 130, 140 separation plate 110a, 120a, 130a, 140a one side 110b, 120b, 130b, 140b other side 111, 121 First flow path section 112, 122 Second flow path section 111a, 121a engraving 111b, 121b intaglio 113 1st distribution section 114 2nd distribution section 210 Membrane-electrode assembly 211 Anode 212 cathode 213 Electrode 214 Separation membrane 311 First Gasket 312 Second gasket 411 Single-sided peripheral gasket 511 Other side peripheral gasket A1, A2 active area B1, B2 inactive area L Longitudinal direction W width direction S Stacking direction P1 First flow path P2 Second flow path

Claims

1. A large number of separation plates; a membrane-electrode assembly disposed between the plurality of separator plates, the membrane-electrode assembly including a plurality of electrodes and a separator membrane disposed between the plurality of electrodes; The separation plate includes a first flow path portion in which reliefs and intaglios are alternately formed on an active area on one side to form a first flow path, and a second flow path portion in which intaglios and intaglios are alternately formed on an active area on the other side to form a second flow path, corresponding to the reliefs and intaglios formed on the first flow path portion.

2. the first flow path portion faces the electrode, and the first flow path through which the raw material fluid moves is open toward the electrode; The electrolyzer according to claim 1 , wherein the second flow path portion faces the electrode, and the second flow path through which the raw material fluid moves opens toward the electrode.

3. 2. The electrolyzer according to claim 1, wherein the plurality of separator plates are stacked with the membrane-electrode assembly sandwiched therebetween such that the one surface and the other surface are inverted relative to each other in the stacking direction.

4. The electrodes include an anode and a cathode, The electrolyzer according to claim 3 , wherein the anodes and the cathodes are alternately positioned in the stacking direction.

5. a first gasket disposed in an inactive area on the one side of the separator plate; a second gasket disposed in an inactive area on the other surface of the separator plate; The electrolyzer according to claim 1 , wherein the first gasket and the second gasket are formed to have different thicknesses in a stacking direction.

6. The electrolyzer according to claim 5 , wherein the first gasket and the second gasket are positioned on the same line in the stacking direction.

7. The relief of the first flow path portion formed in the active region of the one surface of the separation plate is formed to protrude with respect to the inactive region, The electrolyzer according to claim 5 , wherein the recesses of the second flow passages formed in the active area on the other surface of the separator plate are formed in a concave shape relative to the inactive area.

8. a thickness of the first gasket is formed to be equal to a sum of a thickness of an electrode facing the one surface of the separator plate among the plurality of electrodes and a protruding height of a relief formed on the one surface of the separator plate; 8. The electrolyzer of claim 7, wherein the thickness of the second gasket is the same as the thickness of the electrode facing the other surface of the separator plate among the plurality of electrodes.

9. the separator plates and the membrane-electrode assemblies are stacked alternately; 2. The electrolyzer according to claim 1, wherein the separator plates are located at the top and bottom in the stacking direction.

10. The active area on the one surface of the separation plate further includes a first distribution portion through which fluid flows in and out of the first flow path, The electrolyzer of claim 1 , wherein the active area on the other surface of the separator plate further includes a second distribution portion through which fluid flows in and out of the second flow path.

11. The first flow path is formed in a recessed portion of the first flow path portion, The electrolyzer according to claim 1 , wherein the second flow path is formed in a recessed portion of the second flow path portion.

12. The electrolyzer according to claim 1 , wherein the reliefs and depressions formed on the first flow path portion and the second flow path portion are formed in a rectangular shape.

13. 2. The electrolysis device according to claim 1, wherein the width of the depressions formed in the first flow path portion and the width of the depressions formed in the second flow path portion are each 100 to 5000 μm.

14. 2. The electrolyzer of claim 1, wherein the width of the depressions formed in the first flow path portion and the width of the depressions formed in the second flow path portion are the same.

15. 15. The electrolyzer according to claim 1, wherein the thickness of the separator plate is 50 to 500 μm.

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