Membrane electrode assembly, cylinder-type water electrolysis cell and manufacturing method thereof

Abstract

The present invention provides a membrane electrode assembly for water electrolysis, the membrane electrode assembly having a wound jelly-roll structure, wherein a fuel inlet portion is provided at an outer circumferential portion of the membrane electrode assembly to introduce water inwardly, and a gas outlet portion is provided at one end thereof in a winding-axis direction to discharge gas generated by electrochemical reaction.

Description

Membrane electrode assembly, cylindrical water electrolysis cell and method for manufacturing the same

[0001] The present invention relates to a membrane electrode assembly, a cylindrical water electrolysis cell, and a method for manufacturing the same. More specifically, the present invention relates to a membrane electrode assembly for water electrolysis, a cylindrical water electrolysis cell, and a method for manufacturing a membrane electrode assembly.

[0002]

[0003] Recently, in response to global warming, there is a demand for the use of clean energy sources, and as the utilization of hydrogen increases, various types of water electrolysis cells are being developed. The membrane electrode assembly (MEA), which significantly affects the performance of water electrolysis devices, has a structure in which an anode and a cathode are attached to both sides of an electrolyte membrane composed of polymer materials.

[0004] Typically, MEAs for polymer electrolyte exchange membranes (MEAs) for water electrolysis are manufactured as stacks by stacking dozens or hundreds of sheet-type MEAs, similar to separators. Sheet-type stacks require multiple manufacturing steps, resulting in a high defect rate and consequently low production yield. Furthermore, while manufacturing costs can be reduced by increasing the effective surface area of ​​the MEAs and electrodes, there are limitations regarding the size of these devices.

[0005] Meanwhile, stack types are broadly classified into sub-gasket type and cell frame type. In the sub-gasket type, a sub-gasket film is laminated around the electrodes, and a manifold serving as a passage for the supply fluid and generated gas is perforated in the sub-gasket section to facilitate the movement of fluids and gases. The advantages of the sub-gasket type include reinforcing the physical properties of the 3-layer MEA, which facilitates automated continuous processes, and making the stacking process—where the MEA and separator are laminated—easy. Furthermore, the ability to perform a continuous MEA manufacturing process ensures high mass production capability.

[0006] However, the sub-gasket type has a high probability of defects in sub-gasket bonding and manifold cutting, a low final MEA manufacturing yield, and uses a large amount of electrolyte membrane that does not participate in the reaction, and there are problems with additional process costs and material costs due to the addition of a sub-gasket bonding process and the use of a sub-gasket film.

[0007] The cell frame type is a structure in which a frame is combined with the periphery of the MEA to form a stack, and the frame has supply liquid and fish gas passages, and combines MEAs without a manifold. The advantages of the cell frame type include a smaller area of ​​the electrolyte membrane in the unreacted region due to the absence of a manifold in the MEA, and lower processing costs compared to the sub-gasket type because there is no sub-gasket bonding process. However, due to the characteristics of the cell frame, the circular shape provides the most stable stack and hermetic structure. The disadvantages include low mass production capability because the electrode transfer process suitable for mass production cannot be applied to the circular MEA, and continuous processing is difficult in the MEA manufacturing process.

[0008] Therefore, there is an urgent need to develop a new type of membrane electrode assembly that can increase the manufacturing efficiency of MEAs for polymer electrolyte membrane water electrolysis and reduce the use of electrolyte membranes that are not involved in the reaction.

[0009] Korean Published Patent Application No. 10-2011-0022455 is disclosed as background technology for the present invention.

[0010]

[0011] The objective of the present invention is to provide a cylindrical membrane electrode assembly that can reduce manufacturing costs by reducing the use of an electrolyte that does not participate in the reaction in a membrane electrode assembly for a water electrolysis cell, reduce the size of the water electrolysis cell, and effectively increase the water electrolysis efficiency per unit area.

[0012] Another objective of the present invention is to provide a water electrolysis cell capable of miniaturization by including a cylindrical membrane electrode assembly.

[0013] Another objective of the present invention is to provide a method for manufacturing a cylindrical membrane electrode assembly that can be manufactured in a continuous process by transferring the membrane electrode assembly.

[0014] The above and other objectives of the present invention can all be achieved by the present invention described below.

[0015]

[0016] 1. One aspect of the present invention relates to a membrane electrode assembly (MEA) for water electrolysis.

[0017] The above membrane electrode assembly is a membrane electrode assembly for water electrolysis, and

[0018] The above membrane electrode assembly has a wound jelly-roll structure,

[0019] A fuel inlet is formed on the outer periphery of the above membrane electrode assembly for water to flow in, and a gas outlet is formed at one end in the direction of the winding axis for gas generated by an electrochemical reaction to be discharged.

[0020] 2. In the above 1 embodiment, the membrane electrode assembly is formed by sequentially stacking and winding a first electrode separator, a first electrode portion, an electrolyte membrane, a second electrode portion, and a second electrode separator.

[0021] The first electrode portion comprises a first electrode in contact with the electrolyte membrane and a first porous transport layer in contact with the first electrode, and

[0022] The second electrode portion may include a second electrode in contact with the electrolyte membrane and a second porous transport layer in contact with the second electrode.

[0023] 3. In the above 1 or 2 embodiments, the second electrode portion may be longer than the first electrode portion in the winding axis direction.

[0024] 4. In the above 1 to 3 embodiments, an oxygen discharge hole may be formed at the end of the first electrode portion to discharge oxygen.

[0025] 5. Another aspect of the present invention relates to a membrane electrode assembly for water electrolysis having a fuel inlet hole and an oxygen outlet hole formed therein.

[0026] The above membrane electrode assembly includes an anode-side separator;

[0027] A first porous transport layer in contact with the anode-side separator plate;

[0028] An anode attached to the first porous transport layer;

[0029] O-rings spaced apart and disposed on the left and right sides of the above anode;

[0030] Electrolyte membrane to which the above O-ring and anode are attached;

[0031] A cathode disposed on the other side of the anode in contact with the above electrolyte membrane;

[0032] A second porous transport layer attached to the above cathode; and

[0033] A cathode-side separator attached to the second porous transport layer; comprising

[0034] The width of the anode and the first porous transport layer is smaller than the width of the cathode and the second porous transport layer, and

[0035] The above O-ring is positioned between the anode-side separator and the electrolyte membrane to form oxygen discharge holes and fuel inlet holes on both sides of the anode, and

[0036] It is wound into a jelly-roll shape while stacked from the anode-side separator to the cathode-side separator.

[0037] 6. In the above 5 embodiments, the anode-side separator and the cathode-side separator may be made of stainless steel and be ductile.

[0038] 7. In the above 5 or 6 embodiments, fuel is introduced into the fuel inlet hole, the fuel generates a charge through an electrochemical reaction, the charge moves to the cathode, hydrogen is produced through an electrochemical reaction at the cathode, and the hydrogen can move in the direction of the winding axis and be discharged to the outside.

[0039] 8. In the above 5 to 7 embodiments, the oxygen discharge hole is spaced apart from the fuel inlet hole, and the oxygen discharge hole can collect oxygen generated in the anode and discharge it in one direction.

[0040] 9. In the above 5 to 8 embodiments, the O-ring can seal the space between the anode-side separator and the electrolyte membrane so that oxygen or fuel does not leak out to parts other than the oxygen discharge hole and the fuel inlet hole.

[0041] 10. In the above 5 to 9 embodiments, the electrolyte membrane may be a polymer electrolyte membrane (PEM).

[0042] 11. In the above 5 to 10 embodiments, the width of the anode and the first porous transport layer can be determined according to the following Formula 1.

[0043] [Equation 1]

[0044] W O <W1<W2

[0045] W in Equation 1 above O is the width of the oxygen discharge hole, W1 is the width of the anode and the first porous transport layer, and W2 is the width of the cathode and the cathode-side separator.

[0046] 12. Another aspect of the present invention relates to a water electrolysis cell in which the membrane electrode assembly is accommodated.

[0047] The above-mentioned water electrolysis cell comprises a cylindrical case that houses the above-mentioned membrane electrode assembly inside;

[0048] A hydrogen discharge pipe protruding in the axial direction of the above case;

[0049] An oxygen discharge pipe provided on the outer periphery of the above case; and

[0050] It includes a fuel inlet pipe spaced apart from the oxygen exhaust pipe.

[0051] 13. In the above 12 embodiments, a second fuel inlet pipe may be further included on the opposite side of the hydrogen discharge pipe.

[0052] 14. Another aspect of the present invention relates to a method for manufacturing a membrane electrode assembly.

[0053] The above method for manufacturing a membrane electrode assembly comprises: (a) transferring an anode to one side of an electrolyte membrane and transferring a cathode to the other side, and adjusting the width of the anode to be smaller than the width of the cathode;

[0054] (b) a step of laminating a first porous transport layer placed on the anode and a second porous transport layer placed on the cathode;

[0055] (c) A step of joining an O-ring to the side of the anode so as to form a space spaced apart from the anode;

[0056] (d) a step of placing an anode-side separator on the upper part of the first porous transport layer, placing and joining a cathode-side separator on the upper part of the second porous transport layer, and sealing the anode-side separator and the electrolyte membrane with the O-ring; and

[0057] (e) a step of simultaneously winding the anode-side separator and the cathode-side separator to form a jelly-roll shape; comprising,

[0058] It involves forming an oxygen discharge hole and a fuel inlet hole at the end of a jelly-roll shaped membrane electrode assembly.

[0059] 15. In the above 14 embodiments, the transfer process of step (a) can be continuously transferred to a roll-to-roll process.

[0060] 16. In the above 14 or 15 embodiments, the water electrolysis capacity can be determined by adjusting the width and length of the electrolyte membrane in step (a).

[0061] 17. In the above 14 to 16 embodiments, in step (c), the O-ring is positioned to form a space spaced apart from the anode and may be positioned around the entire circumference excluding one side of the anode.

[0062] 18. In the above 14 to 17 embodiments, the anode-side separator and the cathode-side separator in (e) may be made of ductile stainless steel.

[0063]

[0064] The cylindrical membrane electrode assembly according to the present invention can not only reduce the manufacturing cost of the membrane electrode assembly by minimizing the electrolyte area that does not participate in the reaction, but also very effectively increase the electrolytic efficiency per unit area based on the electrolyte.

[0065] Since membrane electrode assemblies can be manufactured using a continuous transfer process, the amount of catalyst and electrolyte membrane used is reduced compared to the cell frame type, which can significantly reduce the manufacturing cost of water electrolysis cells. Additionally, the simplified manufacturing process can significantly reduce the defect rate compared to sub-gasket type water electrolysis cells.

[0066] In addition, since a cylindrical water electrolysis cell can be manufactured by winding the membrane electrode assembly into a jelly roll shape, not only is miniaturization of the water electrolysis cell possible, but it is also possible to manufacture water electrolysis cells of various sizes corresponding to hydrogen production capacity.

[0067]

[0068] FIG. 1 is a perspective view showing a membrane electrode assembly according to one embodiment of the present invention.

[0069] FIG. 2 is a schematic diagram showing the winding state of a membrane electrode assembly according to one embodiment of the present invention.

[0070] Figure 3 is a cross-sectional view along the line A-A' of Figure 2.

[0071] FIG. 4 is a perspective view of a water electrolysis cell according to one embodiment of the present invention.

[0072] FIG. 5 is a process flowchart of a method for manufacturing a membrane electrode assembly according to another aspect of the present invention.

[0073]

[0074] The present invention will be described in more detail below with reference to the attached drawings. However, the following drawings are provided merely to aid in understanding the present invention, and the present invention is not limited by the drawings. Furthermore, the shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings are exemplary, and the present invention is not limited to the depicted details.

[0075] Throughout the specification, the same reference numerals refer to the same components. Additionally, in describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the invention.

[0076] Where terms such as 'includes,' 'have,' and 'consists of' are used in this specification, other parts may be added unless 'only' is used. Where a component is expressed in the singular, it includes cases where it is in the plural unless specifically stated otherwise.

[0077] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0078] In this specification, "a to b" indicating a numerical range is defined as "≥a and ≤b".

[0079] In this specification, all numerical ranges include a 95% standard error range.

[0080]

[0081] One aspect of the present invention relates to a membrane electrode assembly (MEA) for water electrolysis.

[0082] FIG. 1 is a perspective view showing a membrane electrode assembly according to one embodiment of the present invention, FIG. 2 is a schematic diagram showing the winding state of a membrane electrode assembly according to one embodiment of the present invention, and FIG. 3 is a cross-sectional view along line A-A' of FIG. 2.

[0083] A membrane electrode assembly (2000) according to one embodiment of the present invention will be described in detail below with reference to the drawings.

[0084] The above membrane electrode assembly (2000) may be formed by transferring catalyst electrodes to both sides of the electrolyte membrane (700), and may produce electrons and hydrogen through an electrochemical reaction.

[0085] The above membrane electrode assembly (2000) for water electrolysis is wound in a jelly-roll shape. The above membrane electrode assembly (2000) is not in a stacked sheet shape, but is wound in a jelly-roll shape, and the area and electrolytic capacity of the electrolyte membrane (700) can be determined according to the length and width of the electrolyte membrane (700).

[0086] The above membrane electrode assembly (2000) may be provided with a fuel inlet portion into which water is introduced on the outer periphery, and specifically, a fuel inlet hole (400) may be provided. Water or steam, which is fuel, may be introduced through the fuel inlet hole (400).

[0087] The above fuel inlet hole (400) is formed such that the width of one of the electrodes of the membrane electrode assembly (2000) is smaller than that of the other electrode. For example, the membrane electrode assembly (2000) may be formed by sequentially stacking and winding a first electrode separator, a first electrode part (1100), an electrolyte membrane (700), a second electrode part (1200), and a second electrode separator.

[0088] In the present invention, the membrane electrode assembly (2000) means that electrode portions (1100, 1200) including electrodes and porous transport layers are arranged on both sides of the electrolyte membrane (700), and a first electrode separator and a second electrode separator are respectively attached to the outside of each electrode portion.

[0089] For example, the first electrode separator may be an anode separator (100), and the second electrode separator may be a cathode separator (1000).

[0090] If the first electrode part (1100) includes an anode, the second electrode part (1200) includes a cathode, and the electrodes of the electrode parts may be opposite. In this case, the first electrode separator may be a cathode separator, and the second electrode separator may be an anode separator.

[0091] Since the fuel inlet is formed by adjusting the width of the electrode of the first electrode part (1100), separate fuel inlet pipes and oxygen outlet pipes for the separator plate and end plate are not required, as in a sub-gasket type water electrolysis cell, and a manifold for supplying fuel to the separator plate is also not required.

[0092] The first electrode portion (1100) may include an anode (600), which is a first electrode in contact with an electrolyte membrane, and a first porous transport layer (500), which is in contact with the anode (600). The second electrode portion (1200) may include a cathode (800), which is a second electrode in contact with an electrolyte membrane, and a second porous transport layer (900), which is in contact with the cathode (800).

[0093] In the above membrane electrode assembly (2000), the second electrode portion (1200) may be longer than the first electrode portion (1100) in the winding axis direction.

[0094] A fuel inlet hole (400) is formed on the outer periphery of the wound membrane electrode assembly (2000) to allow water to flow in, and hydrogen generated by an electrochemical reaction moves in the direction of the winding axis of the membrane electrode assembly (2000) and is discharged.

[0095] One end of the above winding axis direction may be formed with a gas discharge section through which gas generated by an electrochemical reaction is discharged, for example, a gas discharge section through which hydrogen moves in the winding axis direction and is discharged may be provided.

[0096] The above hydrogen moves to the opposite side of the fuel inlet hole (400) due to the difference in partial pressure of the hydrogen generated as the electrochemical reaction proceeds, and can be discharged to the outside through the gas discharge part with relatively low pressure.

[0097] Specifically, when fuel containing water is introduced from one side of the anode, the charge generated by the electrochemical reaction at the anode (600) moves to the cathode through the separator, and at the cathode, hydrogen (H2) and hydroxide ions (OH) are produced by the electrochemical reaction. - ) is generated. At this time, hydrogen can flow in the opposite direction due to the pressure generated.

[0098] When the area of ​​the porous transport layer (900) through which hydrogen diffuses is larger than that of the membrane electrode assembly (2000) of the sub-gasket type stack, hydrogen diffusion is facilitated, thereby increasing the electrolytic efficiency.

[0099] In one embodiment, the second electrode portion (1100) may be longer than the first electrode portion (1100) in the direction of the winding axis.

[0100] The length and width of the first electrode part (1100) can be adjusted to form a fuel inlet part, and a fuel inlet hole (400) can be formed in the fuel inlet part.

[0101] In one embodiment, an oxygen discharge hole (300) is formed at the end of the membrane electrode assembly (2000) so that oxygen can be discharged.

[0102] Water or steam introduced into the fuel inlet hole (400) is ionized by an electrochemical reaction in the first electrode part (1100), and oxygen is generated in the second electrode part (1200), and the generated oxygen can be discharged to the outside along the oxygen discharge hole (300).

[0103] Accordingly, a membrane electrode assembly (2000) according to one aspect of the present invention has a jelly-roll structure wound with electrodes transferred to both sides of an electrolyte membrane (700), and a fuel inlet hole (400) and an oxygen outlet hole (300) are provided on the outer periphery of the membrane electrode assembly (2000), so there is no need to place an additional manifold, fuel inlet, or oxygen outlet on the separator. The electrolytic capacity can be determined solely by adjusting the length and width of the membrane electrode assembly (2000), and since processes such as cutting and stacking of the electrolyte membrane (700) are not required, the manufacturing labor cost is reduced, and the possibility of defects occurring due to damage to the membrane electrode assembly (2000) during the manufacturing process is greatly reduced.

[0104]

[0105] Another aspect of the present invention relates to a membrane electrode assembly (2000) for water electrolysis having a fuel inlet hole (400) and an oxygen outlet hole (300) formed therein.

[0106] The above membrane electrode assembly (2000) includes an anode-side separator (100), a first porous transport layer (500), an anode (600), an O-ring (200), an electrolyte membrane (700), a cathode (800), a second porous transport layer (900), and a cathode-side separator (1000).

[0107] The above anode-side separator (100) provides a passage for electrons generated at the anode (600) to move.

[0108] The above anode-side separator (100) may be stainless steel coated with one or more of iron (Fe), carbon (C), nickel (Ni), cobalt (Co), or molybdenum (Mo), and may be ductile and capable of bending.

[0109] The first porous transport layer (500) can be in contact with the anode-side separator (100).

[0110] The first porous transport layer (500) above allows oxygen (O2) to move, and oxygen can be collected along the first porous transport layer (500) and discharged outside the membrane electrode assembly (2000).

[0111] The first porous transport layer (500) above can transport water generated during the reaction and discharge it along with oxygen.

[0112] The anode (600) is attached to the first porous transport layer (500).

[0113] The first porous transport layer (500) may be made of a material such as carbon fiber or cellulose and may be adhered to the anode (600).

[0114] The width of the anode (600) and the first porous transport layer (500) is smaller than the width of the cathode (800) and the second porous transport layer (900).

[0115] The width of the anode (600) and the first porous transport layer (500) is smaller than the width of the cathode (800) and the second porous transport layer (900), so that a space can be formed on both sides of the anode (600) and the first porous transport layer (500).

[0116] The above O-ring (200) is spaced apart from the left and right sides of the anode (600).

[0117] The above O-ring (200) is placed between the anode-side separator (100) and the electrolyte membrane (700) to form oxygen discharge holes (300) and fuel inlet holes (400) on both sides of the anode (600).

[0118] Referring to FIG. 3, the O-ring (200) can be spaced apart at regular intervals on the left and right sides of the anode (600), and can form the oxygen discharge hole (300) and the fuel inlet hole (400) by closing one side of the space formed on the sides of the anode (600) and the first porous transport layer (500).

[0119] By adjusting the width of the anode (600) and the first porous transport layer (500) to form a space, and sealing the side of the anode (600) using an O-ring (200), fuel can be introduced using the space within the membrane electrode assembly (2000) without providing a separate oxygen discharge pipe and fuel inlet pipe, and oxygen generated by an electrochemical reaction can be discharged.

[0120] In one embodiment, fuel is introduced into the fuel inlet hole (400), the fuel generates an electric charge through an electrochemical reaction, the electric charge moves to the cathode (800), hydrogen is produced through an electrochemical reaction at the cathode (800), and the hydrogen can move in the direction of the winding axis and be discharged to the outside.

[0121] For example, water is introduced as fuel into the fuel inlet hole (400), and the water is transferred to the anode (600). In the anode (600), electrons and cations (H) are produced through an electrochemical reaction. + ) is generated, and the cation passes through the electrolyte membrane (700) and combines with electrons at the cathode (800) to generate hydrogen (H2) gas. At this time, a pressure difference is created between the anode (600) and the cathode (800) due to the pressure of the fuel flowing into the anode (600), and the partial pressure of the anode (600) can move the hydrogen gas in one direction.

[0122] The above hydrogen gas diffuses along the second porous transport layer (900) and finally moves in the direction of the winding axis of the membrane electrode assembly (2000).

[0123] When all of the above hydrogen moves in the direction of the winding axis, a hydrogen discharge pipe (3200) is positioned in the direction of the winding axis to very effectively collect and supply hydrogen gas.

[0124] In one embodiment, the oxygen discharge hole (300) is spaced apart from the fuel inlet hole (400), and the oxygen discharge hole (300) can collect oxygen generated in the anode (600) and discharge it in one direction.

[0125] The oxygen discharge hole (300) is spaced apart from the fuel inlet hole (400) with respect to the anode (600), and when oxygen generated from the anode (600) diffuses along the first porous transport layer (500), it is ultimately collected along the passage of the oxygen discharge hole (300) and can be discharged to the outside through the oxygen discharge hole (300).

[0126] In one embodiment, the O-ring (200) seals the space between the anode-side separator (100) and the electrolyte membrane (700) so that oxygen or fuel does not leak out to a part other than the oxygen discharge hole (300) and the fuel inlet hole (400).

[0127] The above O-ring (200) can be compressed by the anode-side separator (100) to effectively seal the space between the electrolyte membranes (700), and specifically, by sealing the entire edge of the anode (600) except for the oxygen discharge hole (300) and the fuel inlet hole (400), oxygen or fuel can be prevented from leaking out of the membrane electrode assembly (2000).

[0128] In one embodiment, the oxygen can be discharged only through the oxygen discharge hole (300).

[0129] In one embodiment, the width of the anode (600) and the first porous transport layer (500) can be determined according to the following Equation 1.

[0130] [Equation 1]

[0131] W O <W1<W2

[0132] W in Equation 1 above OW1 is the width of the oxygen discharge hole (300), W1 is the width of the anode (600) and the first porous transport layer (500), and W2 is the width of the cathode (800) and the cathode-side separator (1000).

[0133] The widths of the anode (600) and the first porous transport layer (500) can be determined according to Equation 1, specifically the width (W) of the oxygen discharge hole (300). O It can be provided to be larger than ) and smaller than the width (W2) of the cathode (800) and the cathode-side separator (1000).

[0134] When determining the width of the anode (600) and the first porous transport layer (500) within the range of the above Equation 1, a minimum space for the oxygen discharge hole (300) and the fuel inlet hole (400) can be secured.

[0135] The above electrolyte membrane (700) may have the O-ring (200) and the anode (600) attached to one side.

[0136] In one embodiment, the electrolyte membrane (700) may be a polymer electrolyte membrane (700; PEM).

[0137] The above electrolyte membrane (700) can be manufactured in a jelly-roll form by winding the membrane electrode assembly (2000) with a polymer electrolyte membrane (700), and can exhibit a high current density.

[0138] The above cathode (800) is positioned on the other side of the anode (600) in contact with the electrolyte membrane (700).

[0139] The above cathode (800) is a cation (H + When this passes through the electrolyte membrane (700), it can receive electrons and produce gaseous hydrogen (H2) through an electrochemical reaction.

[0140] The second porous transport layer (900) is attached to the cathode (800).

[0141] The second porous transport layer (900) provides a passage for hydrogen generated in the cathode (800) to move, and the hydrogen moves along the winding axis direction of the membrane electrode assembly (2000) through the second porous transport layer (900).

[0142] The above hydrogen can be discharged to the outside of the membrane electrode assembly (2000) through the second porous transport layer (900), and since the hydrogen moves in one direction along the winding axis direction, hydrogen can be effectively produced and collected when a hydrogen discharge pipe (3200) is additionally arranged in the water electrolysis cell.

[0143] The above cathode-side separator (1000) is attached to the second porous transport layer (900).

[0144] In one embodiment, the anode-side separator (100) and the cathode-side separator (1000) may be made of stainless steel and be ductile.

[0145] The above anode-side separator (100) and cathode-side separator (1000) may be made of stainless steel, which is corrosion-resistant, and may have high workability, particularly due to its ductility.

[0146] When the above anode-side separator plate (100) and cathode-side separator plate (1000) are selected from stainless steel, it is highly desirable because the separator plates can be processed thinly and bent, and also have a low gas permeability.

[0147] Accordingly, in one embodiment of the present invention, the membrane electrode assembly (2000) is formed such that the O-ring (200) is placed between the anode-side separator (100) and the electrolyte membrane (700) to form oxygen discharge holes (300) and fuel inlet holes (400) on both sides of the anode (600), and is wound in a jelly-roll shape while stacked from the anode-side separator (100) to the cathode-side separator (1000). Since the space formed by adjusting the width of the anode (600) is utilized as an oxygen discharge hole (300) and a fuel inlet hole (400), a separate manifold or pipes required for oxygen discharge and fuel inlet are not required compared to a sub-gasket type or cell frame type stack, and the electrolytic capacity can be determined simply by increasing the length of the membrane electrode assembly (2000), and the manufacturing efficiency of the membrane electrode assembly (2000) can be greatly increased by minimizing the area of ​​the electrolyte membrane (700) in the unreacted region that does not participate in the reaction.

[0148]

[0149] Another aspect of the present invention relates to a cylindrical water electrolysis cell in which the membrane electrode assembly (2000) is housed.

[0150] FIG. 4 is a perspective view of a water electrolysis cell according to one embodiment of the present invention.

[0151] Referring to FIG. 4, the cylindrical water electrolysis cell (3000) includes a cylindrical case (3100), a hydrogen discharge pipe (3200), an oxygen discharge pipe (3400), and a fuel inlet pipe (3300).

[0152] The above cylindrical case (3100) may be made of metal, such as stainless steel, and is manufactured by processing into a cylindrical shape.

[0153] The above cylindrical case (3100) can provide a space for accommodating the above-described jelly-roll type membrane electrode assembly (2000).

[0154] The above membrane electrode assembly (2000) can be housed inside the cylindrical case (3100).

[0155] The hydrogen discharge pipe (3200) may be provided protruding in the axial direction of the case (3100).

[0156] Hydrogen moves in the direction of the winding axis of the above membrane electrode assembly (2000), and the hydrogen discharge pipe (3200) is positioned in the direction of hydrogen movement, making it very easy to collect and discharge hydrogen.

[0157] In one embodiment, a second fuel inlet pipe (not shown) may be further included on the opposite side of the hydrogen discharge pipe (3200).

[0158] When a second fuel inlet pipe is placed on the opposite side of the hydrogen discharge pipe (3200), it is possible to introduce more fuel into the water electrolysis cell (3000) through the second fuel inlet pipe, and the electrochemical reaction of the membrane electrode assembly (2000) can be controlled by placing the second fuel inlet pipe (3300).

[0159] The oxygen exhaust pipe (3400) is provided on the outer periphery of the case (3100).

[0160] The above oxygen discharge pipe (3400) may be provided on the outer periphery of a cylindrical case (3100) and, specifically, may be connected to an oxygen discharge hole (300) of a membrane electrode assembly (2000).

[0161] The fuel inlet pipe (3300) is provided spaced apart from the oxygen outlet pipe (3400).

[0162] The above fuel inlet pipe (3300) can also be connected to the fuel inlet hole (400) of the above membrane electrode assembly (2000), and water, which is fuel, can be directly supplied to the fuel inlet hole (400) from the outside.

[0163] The above-described cylindrical water electrolysis cell can produce hydrogen by accommodating a jelly-roll type membrane electrode assembly (2000) and has the advantage of being easy to manufacture, allowing for miniaturization, and also being able to increase the volume according to the required electrolytic capacity, thereby providing water electrolysis cells of various capacities.

[0164]

[0165] Another aspect of the present invention relates to a method for manufacturing a membrane electrode assembly.

[0166] FIG. 5 is a process flowchart of a method for manufacturing a membrane electrode assembly according to another aspect of the present invention.

[0167] Referring to FIG. 5, the method for manufacturing the membrane electrode assembly comprises: (a) transferring an anode to one side of an electrolyte membrane and transferring a cathode to the other side, and adjusting the width of the anode to be smaller than the width of the cathode;

[0168] (b) a step of laminating a first porous transport layer placed on the anode and a second porous transport layer placed on the cathode;

[0169] (c) A step of joining an O-ring to the side of the anode so as to form a space spaced apart from the anode;

[0170] (d) a step of placing an anode-side separator on the upper part of the first porous transport layer, placing and joining a cathode-side separator on the upper part of the second porous transport layer, and sealing the anode-side separator and the electrolyte membrane with the O-ring; and

[0171] (e) A step of simultaneously winding the anode-side separator and the cathode-side separator to form a jelly-roll shape; is included.

[0172] First, an anode is transferred to one side of the electrolyte membrane and a cathode is transferred to the other side, and the width of the anode is adjusted to be smaller than the width of the cathode (S100).

[0173] By adjusting the width of the anode, an oxygen discharge hole and a fuel inlet hole can be formed at the end of the jelly-roll type membrane electrode assembly.

[0174] Although the above anode width may be larger than the above cathode width, since water produces 2 moles of hydrogen for every 1 mole of oxygen, it is desirable to have a larger cathode width to increase hydrogen production.

[0175] In one embodiment, the transfer process of the above S100 can be continuously transferred as a roll-to-roll process.

[0176] When using the above roll-roll process, the membrane electrode assembly can be continuously manufactured in the longitudinal direction, and the area of ​​the electrolyte membrane can be effectively increased, thereby significantly increasing the manufacturing efficiency of the membrane electrode assembly.

[0177] In one embodiment, the water electrolysis capacity can be determined by adjusting the width and length of the electrolyte membrane in S100.

[0178] In S100, the total reaction surface area can be determined by adjusting the width and length of the electrolyte membrane, and the capacity of the water electrolysis cell can be effectively determined.

[0179] A first porous transport layer is placed on the upper part of the anode, and a second porous transport layer is placed on the upper part of the cathode and laminated (S200).

[0180] A first porous transport layer with a width equal to the width of the anode can be placed on the upper part of the anode, and a second porous transport layer with the same width can be placed on the upper part of the cathode to form a laminate.

[0181] At this time, although it can be manufactured by transferring an anode to one side of the electrolyte membrane, it is also possible to form a first electrode portion by coating an electrode on a first porous transport layer and a second electrode portion by coating an electrode on a second porous transport layer to adhere to the electrolyte membrane.

[0182] An O-ring is joined to the side of the anode so that a space is formed between the anode and the anode (S300).

[0183] The width of the above anode is reduced to form a space, and an O-ring is placed and joined to be spaced apart from the above anode to form an oxygen discharge hole and a fuel inlet hole.

[0184] In one embodiment, the O-ring in the S300 is positioned to form a space spaced apart from the anode and may be positioned over the entire perimeter excluding one side of the anode.

[0185] The above O-ring is positioned along the entire circumference of the anode to seal the space between the anode-side separator and the electrolyte membrane, and is not positioned at the end of the membrane electrode assembly so that the oxygen discharge hole and the fuel inlet hole can be left open.

[0186] An anode-side separator is placed on the upper part of the first porous transport layer, and a cathode-side separator is placed on the upper part of the second porous transport layer and joined, and the space between the anode-side separator and the electrolyte membrane is sealed with the O-ring (S400).

[0187] By arranging the anode-side separator and the cathode-side separator and applying pressure to compress and bond the O-ring, the space between the anode-side separator and the electrolyte membrane can be sealed.

[0188] In S400, the O-ring seals the space between the anode-side separator and the electrolyte membrane along the entire perimeter of the anode, thereby preventing oxygen or fuel from leaking out to areas other than the oxygen discharge hole and the fuel inlet hole.

[0189] The above anode-side separator and cathode-side separator are wound simultaneously to form a jelly-roll shape (S500).

[0190] In one embodiment, the anode-side separator and the cathode-side separator in the above S500 may be made of ductile stainless steel.

[0191] The above anode-side separator and cathode-side separator can be bent, so that a jelly-roll type membrane electrode assembly can be manufactured by winding them into a jelly-roll shape while stacked from the anode-side separator to the cathode-side separator.

[0192] In one embodiment, an oxygen discharge hole and a fuel inlet hole can be formed at the end of the jelly-roll type membrane electrode assembly.

[0193] The above membrane electrode assembly has an oxygen discharge hole and a fuel inlet hole formed at the end, and when the membrane electrode assembly is wound to manufacture a jelly-roll shape, an oxygen discharge hole and a fuel inlet hole may be formed along the end of the membrane electrode assembly on the outer periphery of the jelly-roll.

[0194] Accordingly, the method for manufacturing a membrane electrode assembly according to another aspect of the present invention manufactures a membrane electrode assembly for polymer electrolyte membrane (PEM) water electrolysis using a roll-to-roll continuous process, which has very high manufacturing efficiency. During manufacturing, the width of the anode, which is one of the electrode catalysts, is adjusted to secure a space which is then sealed with an O-ring. By winding the membrane electrode assembly into a jelly-roll form, the amount of catalyst used and the area of ​​the unreacted electrolyte membrane can be drastically reduced. Compared to conventional cell-frame type membrane electrode assemblies, the process of cutting and stacking the membrane electrode assembly and arranging a separate fuel and oxygen transport channel, such as a manifold, is eliminated. This not only reduces the number of manufacturing steps but also reduces the amount of electrolyte membrane consumed, thereby very effectively increasing manufacturing efficiency.

[0195]

[0196] Hereinafter, preferred embodiments are presented to aid in understanding the present invention; however, the following embodiments are merely illustrative of the invention and the scope of the invention is not limited to the following embodiments.

[0197]

[0198] Example 1.

[0199] A membrane electrode assembly for water electrolysis was prepared by transferring an electrode catalyst onto a polymer electrolyte membrane with a length of 20 cm and a width of 5 cm.

[0200] The width of the anode was adjusted to 4 cm, and a sealing O-ring was placed to press and join the separator plate. At this time, the total width of the fuel inlet hole and the oxygen outlet hole was made to be 0.8 cm.

[0201] A jelly-roll structure membrane electrode assembly for water electrolysis was manufactured by winding a stacked membrane electrode assembly.

[0202]

[0203] Comparative Example 1

[0204] The reaction zone of the electrolyte membrane and reaction catalyst is 100 cm 2 A fixed unit cell was manufactured by placing a membrane electrode assembly between sub-gaskets so as to be fixed.

[0205]

[0206] Comparative Example 2

[0207] As with Comparative Example 1, the reaction catalyst reaction zone is 100 cm 2 A unit cell was manufactured by cutting the membrane electrode assembly to fix it to a circular cell frame so as to be fixed to the cell frame.

[0208]

[0209] Experimental Example 1

[0210] In the case of the jelly-roll type membrane electrode assembly in Example 1, the electrolyte membrane is 100 cm 2 Although the entire area is utilized for the electrochemical reaction and non-reactive zones can be excluded, the total area of ​​the electrolyte membrane used to fix the sub-gasket in Comparative Example 1 is 200 cm² 2 That is all, and the area of ​​the electrode catalyst is 130 cm² 2 It was nothing more than that.

[0211] Comparative Example 2 also 100 cm 2 To form the reaction zone, an electrolyte membrane of 150 cm 2- It was confirmed that unnecessary electrolyte membrane consumption increases as it is required.

[0212] Therefore, it was confirmed that the membrane electrode assembly according to the present invention prevents the consumption of catalyst and electrolyte membranes, resulting in a much higher manufacturing efficiency than conventional cell frame type membrane electrode assemblies.

[0213]

[0214] The present invention has been described above with reference to embodiments. Those skilled in the art will understand that the present invention may be embodied in modified forms without departing from the essential characteristics of the invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the invention is defined by the claims, not by the foregoing description, and all variations within the scope of equivalents should be interpreted as being included in the invention.

Claims

1. It is a membrane electrode assembly for water electrolysis, and The above membrane electrode assembly has a wound jelly-roll structure, A fuel inlet is formed on the outer periphery of the above membrane electrode assembly for water to flow in, and a gas outlet is formed on one end in the direction of the winding axis for gas generated by an electrochemical reaction to be discharged. Membrane electrode assembly.

2. In claim 1, the membrane electrode assembly comprises a first electrode separator, a first electrode part, an electrolyte membrane, a second electrode part, and a second electrode separator, which are sequentially stacked and wound. The first electrode portion comprises a first electrode in contact with the electrolyte membrane and a first porous transport layer in contact with the first electrode, and The above second electrode portion comprises a second electrode in contact with the electrolyte membrane and a second porous transport layer in contact with the second electrode, forming a membrane electrode assembly.

3. A membrane electrode assembly according to paragraph 2, wherein the second electrode portion is longer than the first electrode portion in the direction of the winding axis.

4. A membrane electrode assembly according to paragraph 2, wherein an oxygen discharge hole is formed at the end of the first electrode portion to discharge oxygen.

5. Anode-side separator; A first porous transport layer in contact with the anode-side separator plate; An anode attached to the first porous transport layer; O-rings spaced apart and disposed on the left and right sides of the above anode; Electrolyte membrane to which the above O-ring and anode are attached; A cathode disposed on the other side of the anode in contact with the above electrolyte membrane; A second porous transport layer attached to the above cathode; and A cathode-side separator attached to the second porous transport layer; comprising The width of the anode and the first porous transport layer is smaller than the width of the cathode and the second porous transport layer, and The above O-ring is positioned between the anode-side separator and the electrolyte membrane to form oxygen discharge holes and fuel inlet holes on both sides of the anode, and A jelly-roll wound in a stacked state from the anode-side separator to the cathode-side separator, Membrane electrode assembly.

6. A cylindrical membrane electrode assembly according to claim 5, wherein the anode-side separator and the cathode-side separator are made of ductile stainless steel.

7. A cylindrical membrane electrode assembly according to claim 5, wherein the fuel inlet hole receives fuel, generates a charge through an electrochemical reaction, moves to a cathode, produces hydrogen through an electrochemical reaction at the cathode, and the hydrogen moves in the direction of the winding axis and is discharged to the outside.

8. A cylindrical membrane electrode assembly according to claim 5, wherein the oxygen discharge hole is spaced apart from the fuel inlet hole, and the oxygen discharge hole collects oxygen generated at the anode and discharges it in one direction.

9. A cylindrical membrane electrode assembly according to claim 5, wherein the O-ring seals the space between the anode-side separator and the electrolyte membrane to prevent oxygen or fuel from leaking out to a part other than the oxygen discharge hole and the fuel inlet hole.

10. A cylindrical membrane electrode assembly according to claim 5, wherein the electrolyte membrane is a polymer electrolyte membrane (PEM).

11. A cylindrical membrane electrode assembly according to claim 5, wherein the widths of the anode and the first porous transport layer are determined according to the following formula 1: [Equation 1] IN O <W1<W2 W in Equation 1 above O is the width of the oxygen discharge hole, W1 is the width of the anode and the first porous transport layer, and W2 is the width of the cathode and the cathode-side separator.

12. A cylindrical case housing a membrane electrode assembly according to any one of claims 5 to 11; A hydrogen discharge pipe protruding in the axial direction of the above case; An oxygen discharge pipe provided on the outer periphery of the above case; and A fuel inlet pipe provided spaced apart from the oxygen exhaust pipe; comprising Cylindrical water electrolysis cell.

13. A cylindrical water electrolysis cell according to claim 12, further comprising a second fuel inlet pipe on the opposite side of the hydrogen discharge pipe. 14.(a) A step of transferring an anode to one side of an electrolyte membrane and transferring a cathode to the other side, and adjusting the width of the anode to be smaller than the width of the cathode; (b) a step of laminating a first porous transport layer placed on the anode and a second porous transport layer placed on the cathode; (c) A step of joining an O-ring to the side of the anode so as to form a space spaced apart from the anode; (d) a step of placing an anode-side separator on the upper part of the first porous transport layer, placing and joining a cathode-side separator on the upper part of the second porous transport layer, and sealing the anode-side separator and the electrolyte membrane with the O-ring; and (e) a step of simultaneously winding the anode-side separator and the cathode-side separator to form a jelly-roll shape; comprising, Forming an oxygen discharge hole and a fuel inlet hole at the end of a jelly-roll type membrane electrode assembly, Method for manufacturing a membrane electrode assembly.

15. A method for manufacturing a membrane electrode assembly according to claim 14, wherein the transfer process of step (a) above is continuously transferred as a roll-to-roll process.

16. A method for manufacturing a membrane electrode assembly according to claim 14, wherein the water electrolysis capacity is determined by adjusting the width and length of the electrolyte membrane in step (a) above.

17. A method for manufacturing a membrane electrode assembly according to claim 14, wherein in step (c) above, the O-ring is positioned to form a space spaced apart from the anode and is positioned around the entire circumference excluding one side of the anode.

18. A method for manufacturing a membrane electrode assembly according to claim 14, wherein the anode-side separator and the cathode-side separator in (e) above are made of ductile stainless steel.

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