Membrane-electrode assembly, method for manufacturing the membrane-electrode assembly, and fuel cell comprising the membrane-electrode assembly

Abstract

The present application discloses a membrane-electrode assembly, which has an increased active area, improved fluid control capability and reduced gas transmission resistance due to electrodes with patterned structures on both sides. The present application also discloses a method for manufacturing the membrane-electrode assembly and a fuel cell including the membrane-electrode assembly. The membrane-electrode assembly according to the present invention includes: a first electrode; a second electrode; and a polymer electrolyte membrane between the first electrode and the second electrode, wherein the first electrode has a first surface facing the polymer electrolyte membrane and a second surface opposite to the first surface, the first surface has a first patterned structure, and the second surface has a second patterned structure.

Description

Technical Field

[0001] The present disclosure relates to a membrane-electrode assembly, a method for manufacturing the membrane-electrode assembly, and a fuel cell including the membrane-electrode assembly, and more specifically, to a membrane-electrode assembly having an increased active area, improved fluid control capability, and reduced gas transmission resistance due to double-sided patterned electrodes, a method for manufacturing the membrane-electrode assembly, and a fuel cell including the membrane-electrode assembly. Background Art

[0002] Polymer electrolyte membrane fuel cells (PEMFCs) are constructed to generate electricity using a structure in which unit cells each including a membrane-electrode assembly (MEA) and a separator (also called a bipolar plate) are stacked, and have attracted attention as a next-generation energy source capable of replacing fossil fuels due to their high energy efficiency and environmentally friendly features.

[0003] A membrane-electrode assembly generally includes an anode (also called a fuel electrode), a cathode (also called an air electrode), and a polymer electrolyte membrane (PEM) therebetween.

[0004] When a fuel such as hydrogen is supplied to the anode, hydrogen ions (H 2 O 2 ) are generated at the anode due to the hydrogen-oxygen reaction. + ) and electron (e - ). The generated hydrogen ions are transferred to the cathode via the polymer electrolyte membrane (PEM), and the generated electrons are transferred to the cathode via an external circuit. Oxygen in the air supplied to the cathode combines with the hydrogen ions and the electrons, and water is generated due to reduction.

[0005] Since each of the electrodes and polymer electrolyte membrane (PEM) of a conventional membrane-electrode assembly has a smooth surface, the active area of ​​each of the electrodes and the polymer electrolyte membrane is substantially equal to the projected area of ​​the electrodes. Therefore, in order to increase the active area of ​​the electrodes and the polymer electrolyte membrane, the size of the electrodes must be increased, which leads to increased costs.

[0006] In addition, when a diaphragm including a flow channel portion (i.e., a groove) serving as a fluid path and other portions, i.e., a non-channel portion, is fixed to a membrane-electrode assembly by pressure, a portion of the electrode corresponding to the non-channel portion is compressed, causing the movement of a fluid (e.g., oxygen, hydrogen, or water) to be affected.

[0007] Specifically, the oxygen that must be reduced at the cathode accounts for only about 20% of the air supplied to the cathode, and the water produced by the oxygen reduction reaction interferes with the diffusion of oxygen in the cathode. Therefore, for the cathode, it is particularly necessary to increase the active area to achieve smooth discharge of water and reduce oxygen transmission resistance.

[0008] In order to increase the active area of ​​each of the electrode and the polymer electrolyte membrane, it has been proposed to form concavoconvex on the surface of the polymer electrolyte membrane. However, this method has the problem that the decal transfer method (decal transfer method) as a conventional electrode formation method cannot be used, and the polymer electrolyte membrane needs to be directly coated with a catalyst dispersion. In addition, if the catalyst dispersion directly coated on the polymer electrolyte membrane has a poor catalyst dispersion state, the catalyst cannot penetrate into the patterned groove of the polymer electrolyte membrane, thereby increasing the interface resistance between the electrode and the polymer electrolyte membrane.

[0009] Meanwhile, in order to minimize the oxygen transport resistance of the cathode, it has been proposed to form a cathode composed of a plurality of sub-electrodes spaced apart from each other. However, exposure of the electrolyte membrane between the sub-electrodes causes loss of active area of ​​the membrane-electrode assembly and degradation of durability. Summary of the invention

[0010] Technical issues

[0011] Accordingly, the present disclosure is directed to a membrane-electrode assembly capable of preventing problems caused by the above-mentioned limitations and disadvantages of the related art, a method of manufacturing the membrane-electrode assembly, and a fuel cell including the membrane-electrode assembly.

[0012] An object of the present disclosure is to provide a membrane-electrode assembly having an increased active area, improved fluid control capability, and reduced gas transport resistance due to double-sided patterned electrodes.

[0013] Another object of the present disclosure is to provide a method of manufacturing a membrane-electrode assembly having an increased active area, improved fluid control capability, and reduced gas transport resistance due to double-sided patterned electrodes.

[0014] Another object of the present disclosure is to provide a fuel cell having excellent performance and high durability.

[0015] In addition to the above-mentioned objects, other features and advantages of the present disclosure will be described hereinafter, or those skilled in the art to which the present disclosure belongs will clearly understand the present disclosure through the following description.

[0016] Technical Solution

[0017] According to one aspect of the present disclosure, a membrane-electrode assembly is provided, comprising: a first electrode; a second electrode; and a polymer electrolyte membrane between the first electrode and the second electrode, wherein the first electrode has a first surface facing the polymer electrolyte membrane and a second surface opposite to the first surface, the first surface has a first patterned structure, and the second surface has a second patterned structure.

[0018] The first electrode may include an intermediate layer between the first patterned structure and the second patterned structure, and a thickness of the intermediate layer is 10% to 90% of a thickness of the first electrode.

[0019] The first patterned structure may be different from the second patterned structure.

[0020] At least one of the first patterned structure and the second patterned structure may have a plurality of protrusions dispersed over an entire area of ​​the first surface or the second surface.

[0021] A height of each of the protrusions may be 1 μm to 50 μm, and a diameter of a circumscribed circle of a bottom surface of each of the protrusions may be 10 μm to 1000 μm.

[0022] The first patterned structure may have the protrusion.

[0023] At least one of the first patterned structure and the second patterned structure may include: at least one protrusion pattern extending in a direction parallel to the first surface and the second surface; and a concave pattern adjacent to the protrusion pattern.

[0024] The protrusion pattern may have a height of 1 μm to 50 μm, and a width of 10 μm to 1000 μm.

[0025] At least one of the first patterned structure and the second patterned structure may include a plurality of the protrusion patterns arranged in parallel with each other.

[0026] The protrusion pattern may have a zigzag shape.

[0027] The first electrode may be a cathode, and the second electrode may be an anode.

[0028] According to another aspect of the present disclosure, a method for manufacturing a membrane-electrode assembly is provided, the method comprising: applying a catalyst dispersion to a first release film having a first concave pattern; covering the applied catalyst dispersion with a second release film having a second concave pattern or a plurality of holes; drying at least a surface of the catalyst dispersion to form an electrode; removing the second release film; transferring the electrode to a polymer electrolyte membrane; and removing the first release film.

[0029] The first concave pattern may include at least one groove extending in a direction parallel to the surface of the first release film, and a depth of the groove may be 1 μm to 50 μm.

[0030] The second debossed pattern may be different from the first debossed pattern.

[0031] The second release film may have the plurality of holes.

[0032] The second release film may have a thickness of 10 μm to 100 μm, and each of the holes may have a diameter of 10 μm to 1000 μm.

[0033] The method may further include drying the electrode immediately after removing the second release film.

[0034] According to another aspect of the present disclosure, a fuel cell is provided, comprising: the membrane-electrode assembly; and a diaphragm arranged on the second patterned structure of the first electrode, wherein the second patterned structure comprises: at least one protruding pattern extending in a direction parallel to the first surface and the second surface; and a concave pattern adjacent to the protruding pattern, the diaphragm having a third surface facing the membrane-electrode assembly and a fourth surface opposite to the third surface, the third surface comprising: a groove-shaped channel portion serving as a fluid path; and a non-channel portion, and the membrane-electrode assembly is aligned with the diaphragm so that the non-channel portion corresponds to the concave pattern.

[0035] The protrusion pattern of the second patterned structure may have the same shape as the channel portion.

[0036] A width of the protrusion pattern of the second patterned structure may be no greater than a width of the channel portion.

[0037] The general description of the present disclosure given above is only for illustrating or describing the present disclosure and cannot limit the scope of rights of the present disclosure.

[0038] Beneficial Effects

[0039] According to the present disclosure, the electrode is configured so that the surface of the electrode in contact with the polymer electrolyte membrane has a patterned structure, and the opposite surface of the electrode also has a patterned structure, thereby increasing the active area of ​​each of the polymer electrolyte membrane and the electrode. That is, the membrane-electrode assembly according to the present disclosure can have an increased active area and improved fluid control capability due to the double-sided patterned electrode, and the fuel cell according to the present disclosure can have excellent performance and high durability.

[0040] Furthermore, the electrode according to the present disclosure can be formed using a decal transfer method which is a conventional electrode forming method, facilitating mass production.

[0041] In particular, since the opposite surface of the cathode has the patterned structure, it is possible to minimize oxygen transport resistance in the cathode and improve water control capability in the cathode. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings are included to assist in the understanding of the present disclosure and are incorporated in and constitute a part of this specification. They illustrate embodiments of the present disclosure and together with the detailed description of the present disclosure, serve to explain the principles of the present disclosure.

[0043] Figure 1 schematically illustrates a cross section of a membrane-electrode assembly according to one embodiment of the present disclosure;

[0044] Figure 2 A cross section of a double-sided patterned electrode according to one embodiment of the present disclosure is schematically shown.

[0045] Figure 3 (a) to 3(c) show various examples of patterned structures according to the present disclosure;

[0046] Figure 4 (a) to 4(c) show longitudinal cross-sections of various examples of protrusions or protrusion patterns according to the present disclosure;

[0047] Figure 5a to Figure 5h is a cross-sectional view for describing a method of manufacturing a membrane-electrode assembly according to one embodiment of the present disclosure;

[0048] Figure 6 A cross section of a fuel cell according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0049] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the following examples are provided only for clear understanding of the present disclosure and are not intended to limit the scope of the present disclosure.

[0050] Figure 1 Schematically illustrates a cross section of a membrane-electrode assembly 1000 according to one embodiment of the present disclosure, Figure 2 A cross section of a double-sided patterned electrode 1210 according to one embodiment of the present disclosure is schematically shown.

[0051] like Figure 1 As shown in , the membrane-electrode assembly 1000 according to the present disclosure includes: a first electrode 1210 ; a second electrode 1220 ; and a polymer electrolyte membrane 1100 located between the first electrode 1210 and the second electrode 1220 .

[0052] According to the present disclosure, the first electrode 1210 is a double-sided patterned electrode. Figure 1, a membrane-electrode assembly 1000 is shown, which is configured such that only the first electrode 1210 is a double-sided patterned electrode and the second electrode 1220 is a double-sided smooth electrode. However, the present disclosure is not limited thereto. The second electrode 1220 may also be a double-sided patterned electrode in the same manner as the first electrode 1210.

[0053] like Figure 2 As shown in , the first electrode 1210 has a first surface facing the polymer electrolyte membrane 1100; and a second surface opposite to the first surface, the first surface has a first patterned structure 1211, and the second surface has a second patterned structure 1212.

[0054] The first patterned structure 1211 according to the present disclosure may increase the active areas of both the first electrode 1210 and the polymer electrolyte membrane 1100 , thereby improving the performance of the membrane-electrode assembly 1000 and the performance of the fuel cell.

[0055] The second patterned structure 1212 according to the present disclosure may reduce gas transmission resistance in the first electrode 1210 , thereby improving the performance of the membrane-electrode assembly 1000 and the performance of the fuel cell.

[0056] In one embodiment of the present disclosure, Figure 2 As shown in , the first electrode 1210 may include an intermediate layer 1213 between the first patterned structure 1211 and the second patterned structure 1212. The thickness T2 of the intermediate layer 1213 may be 10% to 90% of the thickness T1 of the first electrode 1210. If the percentage of the thickness T2 of the intermediate layer 1213 is less than 10%, the gas supplied to the first electrode 1210 may easily pass through the first electrode 1210 and then be transmitted to the second electrode 1220, thereby reducing the performance and durability of the membrane-electrode assembly 1000. On the other hand, if the percentage of the thickness T2 of the intermediate layer 1213 is greater than 90%, the size of the patterns of the first patterned structure 1211 and the second patterned structure 1212 may be excessively reduced, so that the effect to be achieved by the present disclosure may not be significant.

[0057] exist Figure 2 , a membrane-electrode assembly 1000 is shown, which is configured such that a first patterned structure 1211 and a second patterned structure 1212 are different from each other. However, the present disclosure is not limited thereto. The first patterned structure 1211 and the second patterned structure 1212 may be the same as each other.

[0058] Figure 3 (a) to 3(c) show various examples of patterned structures according to the present disclosure.

[0059] like Figure 3As shown in (a), at least one of the first patterned structure 1211 and the second patterned structure 1212 may have a plurality of protrusions 1211 a and 1212 a dispersed over the entire area of ​​the first surface or the second surface.

[0060] For example, Figure 2 As shown in , the first patterned structure 1211 in contact with the polymer electrolyte membrane 1100 may include a plurality of protrusions 1211 a dispersed over the entire area of ​​the first surface of the first electrode 1210 .

[0061] The height of each protrusion 1211 a may be 1 μm to 50 μm, and the diameter of a circumscribed circle of the bottom surface of each protrusion 1211 a may be 10 μm to 1000 μm.

[0062] like Figure 3 As shown in (b) and 3(c), at least one of the first patterned structure 1211 and the second patterned structure 1212 may include at least one protruding pattern 1211a or 1212a extending in a direction parallel to the first surface and the second surface and a concave pattern adjacent to the protruding pattern 1211a or 1212a.

[0063] For example, the second patterned structure 1212 may include at least one protruding pattern 1212 a extending in a direction parallel to the first surface and the second surface and a concave pattern 1212 b adjacent to the protruding pattern 1212 a .

[0064] The protrusion pattern 1212 a may have a height of 1 μm to 50 μm, and a width of 10 μm to 1000 μm.

[0065] At least one of the first patterned structure 1211 and the second patterned structure 1212 may include a plurality of protrusion patterns 1211a or 1212a arranged in parallel with each other. Figure 3 (b), or may include zigzag convex patterns 1211a or 1212a, such as Figure 3 As shown in (c).

[0066] For example, the second patterned structure 1212 may include a plurality of protruding patterns 1212a arranged in parallel to each other, or may include a zigzag protruding pattern 1212a. In particular, preferably, the second patterned structure 1212 that will face the diaphragm in the fuel cell stack includes a protruding pattern 1212a having a shape and size corresponding to the flow channel of the diaphragm, and the specific reason will be described below.

[0067] Figure 4 (a) to 4(c) show longitudinal cross-sections of various examples of the protrusion / protrusion pattern 1211a or 1212a according to the present disclosure.

[0068] exist Figure 1 and 2 In the embodiment, the protrusion / protrusion pattern 1211a or 1212a is shown as having a semicircular or rectangular longitudinal cross section. However, the present disclosure is not limited thereto. The protrusion / protrusion pattern 1211a or 1212a may have a longitudinal cross section of any shape. For example, the longitudinal cross section of the protrusion / protrusion pattern 1211a or 1212a may have a partially curved shape (e.g., Figure 4 (a)) or any polygonal shape (e.g. Figure 4 (b) and the shapes shown in 4(c)).

[0069] As mentioned above, the oxygen that must be reduced at the cathode accounts for only about 20% of the air supplied to the cathode, and the water produced by the oxygen reduction reaction interferes with the diffusion of oxygen in the cathode. Therefore, for the cathode, it is particularly necessary to increase the active area to achieve smooth discharge of water and reduce the oxygen transmission resistance. Therefore, in one embodiment of the present invention, the first electrode 1210 as a double-sided patterned electrode can be a cathode, and the second electrode 1220 can be an anode.

[0070] In the following, reference will be made to Figure 5a to Figure 5h A method of manufacturing a membrane-electrode assembly according to the present disclosure is described in detail.

[0071] First, if Figure 5a As shown in FIG. 1 , a first release film 10 having a first concave pattern 11 is prepared. The first concave pattern 11 may include at least one groove extending in a direction parallel to the surface of the first release film 10, and the depth of the groove may be 1 μm to 50 μm.

[0072] Then, if Figure 5b As shown in FIG. 1 , a mask 21 is adhered to the surface of a first release film 10 having a first concave pattern 11. A first catalyst dispersion 1210' is applied to a portion of the first release film 10 exposed by an opening of the mask 21 (i.e., a portion of the first release film formed with the first concave pattern 11). After the first catalyst dispersion 1210' is introduced into the first concave pattern 11, a protruding pattern 1212a of a second patterned structure 1212 is formed by a subsequent drying process.

[0073] Any catalyst dispersion that can be used to make an electrode for a fuel cell can be used in the present disclosure. For example, the first catalyst dispersion 1210' can include a catalyst, an ionomer, and a dispersion medium.

[0074] The catalyst may include a support and a plurality of metal particles dispersed on the support.

[0075] The carrier can be: (i) a carbon-based carrier; (ii) a porous inorganic oxide carrier, such as zirconium oxide, aluminum oxide, titanium dioxide, silicon dioxide, or ceria, or (iii) a zeolite carrier. The carbon-based carrier can be graphite, super P, carbon fiber, carbon sheet, carbon black, Ketjen black, superconductive acetylene black (Denka black), acetylene black (acetylene black), carbon nanotube (CNT), carbon sphere, carbon ribbon, fullerene, activated carbon, carbon nanofiber, carbon nanowire, carbon nanosphere, carbon nanohorn, carbon nanocage, carbon nanoring, ordered nano / mesoporous carbon, carbon aerogel, mesoporous carbon, graphene, stable carbon, activated carbon or a combination of two or more thereof.

[0076] The metal particles may be platinum (Pt) particles or platinum alloy particles. The platinum alloy may be Pt-Pd, Pt-Mn, Pt-Sn, Pt-Mo, Pt-W, Pt-Ru, Pt-Ru-W, Pt-Ru-Ni, Pt-Ru-Mo, Pt-Ru-Rh-Ni, Pt-Ru-Sn-W, Pt-Ru-Ir-Ni, Pt-Co, Pt-Co-Mn, Pt-Co-Ni, Pt-Co-Fe, Pt-Co-Ir, Pt-Co-S, Pt-Co-P, Pt-Fe, Pt-Fe-Ir, Pt-Fe-S, Pt-Fe-P, Pt-Au-Co, Pt-Au-Fe, Pt-Au-Ni, Pt-Ni, Pt-Ni-Ir, Pt-Cr or Pt-Cr-Ir. However, the present disclosure is not limited thereto.

[0077] An ionomer dispersed in a dispersion medium together with a catalyst is provided to transport cations and also functions as a binder to increase the adhesion between the electrode and the polymer electrolyte membrane. The ionomer may be a fluorine-based ionomer or a hydrocarbon ionomer, and may have at least one ion-conducting group selected from a sulfonic acid group, a carboxyl group, a boric acid group, a phosphoric acid group, an imide group, a sulfonimide group, a sulfonamide group, and a sulfonyl fluoride group.

[0078] For example, the ionomer may be a fluorine-based ionomer, such as poly(perfluorosulfonic acid) or poly(perfluorocarboxylic acid).

[0079] Alternatively, the ionomer can be a hydrocarbon ionomer such as a sulfonated polyimide (S-PI), a sulfonated polyarylethersulfone (S-PAES), a sulfonated polyetheretherketone (SPEEK), a sulfonated polybenzimidazole (SPBI), a sulfonated polysulfone (S-PSU), a sulfonated polystyrene (S-PS), a sulfonated polyphosphazene, a sulfonated polyquinoxaline, a sulfonated polyketone, a sulfonated polyphenylene ether, a sulfonated polyethersulfone, a sulfonated polyetherketone, a sulfonated polyphenylene sulfide, a sulfonated polyphenylene sulfide sulfone, a sulfonated polyphenylene sulfide sulfone nitrile, a sulfonated polyarylether, a sulfonated polyarylether nitrile, a sulfonated polyarylether ether nitrile, or a sulfonated polyarylether sulfoneketone.

[0080] The dispersion medium may be ethanol, distilled water, isopropanol, n-propanol, butanol, or a mixture of two or more thereof. However, the present disclosure is not limited thereto.

[0081] Then, if Figure 5c As shown in FIG. 1 , the applied first catalyst dispersion 1210 ′ is covered with a second release film 30. The second release film 30 according to the present disclosure has a second concave pattern or a plurality of holes.

[0082] For example, the second release film 30 may have a second concave pattern different from the first concave pattern 11 of the first release film 10 .

[0083] Or, if Figure 5c As shown in , the second release film 30 may have a plurality of holes 31 dispersed over the entire area to be in contact with the first catalyst dispersion 1210'. In the subsequent drying process, the dispersion medium of the first catalyst dispersion 1210' can be easily removed through the holes 31. The thickness of the second release film 30 (i.e., the depth of each hole 31) may be 10 μm to 100 μm, and the diameter of each hole 31 may be 10 μm to 1000 μm. After the first catalyst dispersion 1210' is introduced into the hole 31 by capillary action, the protrusion 1211a of the first patterned structure 1211 is formed by a subsequent drying process.

[0084] Then, if Figure 5d As shown in FIG. 1 , at least the surface of the first catalyst dispersion 1210 ′ is dried to form the first electrode 1210 , and the second release film 30 and the mask 21 are removed.

[0085] Although the second release film 30 and the mask 21 can be removed after the first catalyst dispersion 1210' is completely dried, in terms of the efficiency of the drying process, it is preferred to dry only the surface of the first catalyst dispersion 1210' to the extent that the shape of the first electrode 1210 is maintained, remove the second release film 30 and the mask 21, and further dry the first electrode 1210 to completely remove the dispersion medium therein.

[0086] The first electrode 1210 formed as described above has an exposed first patterned structure 1211 and a second patterned structure 1212 in contact with the first release film 10 .

[0087] The first electrode 1210 may be stacked on the polymer electrolyte membrane 1100 such that the first patterned structure 1211 contacts the polymer electrolyte membrane 1100 , a heat pressing process may be performed to transfer the first electrode 1210 to the polymer electrolyte membrane 1100 , and the first release film 10 may be removed.

[0088] However, more typically, the first electrode 1210 and the second electrode 1220 are transferred to the polymer electrolyte membrane 1100 simultaneously.

[0089] That is to say, Figure 5e As shown in FIG. 1 , mask 22 is attached to third release film 40, and second catalyst dispersion 1220' is applied to portions of third release film 40 exposed through openings of mask 22. Second catalyst dispersion 1220' may have the same composition as first catalyst dispersion 1210', and thus a detailed description thereof will be omitted.

[0090] Then, if Figure 5f As shown in FIG. 1 , the second catalyst dispersion 1220 ′ is completely dried to form the second electrode 1220 , and the mask 22 is removed.

[0091] Then, if Figure 5g As shown in , the first electrode 1210 is stacked on the first surface of the polymer electrolyte membrane 1100 so that the first patterned structure 1211 contacts the polymer electrolyte membrane 1100 , and the second electrode 1220 is stacked on the second surface of the polymer electrolyte membrane 1100 .

[0092] The polymer electrolyte membrane 1100 may be a single membrane type electrolyte membrane formed of an ionomer or a reinforced composite membrane type electrolyte membrane including a porous support impregnated with an ionomer. In these two types of polymer electrolyte membranes 1100, the ionomer of the first catalyst dispersion 1210' or the second catalyst dispersion 1220' may be used. Preferably, the ionomer of the polymer electrolyte membrane 1100 and the ionomer of each of the first electrode 1210 and the second electrode 1220 are of the same kind. However, the present disclosure is not limited thereto. Different kinds of ionomers may be used to manufacture the polymer electrolyte membrane 1100 and the first electrode 1210 and the second electrode 1220.

[0093] Then, if Figure 5h As shown in , the obtained laminate is hot-pressed to transfer the first electrode 1210 and the second electrode 1220 to the first surface and the second surface of the polymer electrolyte membrane 1100, respectively, and the first release film 10 and the third release film 40 are removed, thereby obtaining the membrane-electrode assembly 1000 according to the present disclosure.

[0094] In the following, reference will be made to Figure 6 A fuel cell according to the present disclosure is described in detail.

[0095] like Figure 6 As shown in , the fuel cell according to the present disclosure includes the membrane-electrode assembly 1000 according to the present disclosure and a first separator 1510 disposed on the second patterned structure 1212 of the first electrode 1210 .

[0096] In the present embodiment, the second patterned structure 1212 includes at least one protruding pattern 1212 a extending in a direction parallel to the first surface and the second surface of the first electrode 1210 and a concave pattern 1212 b adjacent to the protruding pattern 1212 a .

[0097] The first separator 1510 has a third surface facing the membrane-electrode assembly 1000 and a fourth surface opposite to the third surface, the third surface including: a groove-shaped first channel portion 1511 serving as a fluid path; and a first non-channel portion 1512 .

[0098] As described above, when the first separator 1510 is fixed to the membrane-electrode assembly 1000 by pressure, a portion of the first electrode 1210 corresponding to the first non-channel portion 1512 is compressed, so that movement of a fluid (eg, oxygen, hydrogen, or water) is affected.

[0099] According to the present disclosure, the membrane-electrode assembly 1000 is aligned with the first diaphragm 1510 so that the first non-channel portion 1512 corresponds to the concave pattern 1212b of the second patterned structure 1212, thereby minimizing the compression deformation of the first electrode 1210 and improving the fluid control ability of the membrane-electrode assembly 1000 when compressing and fixing the first diaphragm 1510, thereby improving the performance and durability of the fuel cell. In particular, when the first electrode 1210 is a cathode, the oxygen transport resistance in the cathode can be minimized and the water control ability in the cathode can be improved.

[0100] In order to maximize the effects of the present disclosure described above, preferably, the second patterned structure 1212 includes a protruding pattern 1212a having a shape and size corresponding to the first channel portion 1511 of the first diaphragm 1510. For example, the protruding pattern 1212a of the second patterned structure 1212 may have the same shape as the first channel portion 1511 of the first diaphragm 1510, and the width of the protruding pattern 1212a may be greater than the width of the first channel portion 1511.

[0101] like Figure 6 As shown in FIG. 1 , the fuel cell according to the present disclosure may further include a second separator 1520 disposed on the second electrode 1220. The second separator 1520 may also include a second channel portion 1521 and a second non-channel portion 1522 formed on a surface thereof facing the membrane-electrode assembly 1000.

[0102] like Figure 6 As shown in , the fuel cell according to the present disclosure may also include: a first subgasket 1310 disposed on the first surface of the polymer electrolyte membrane 1100 to surround the first electrode 1210; and a second subgasket 1320 disposed on the second surface of the polymer electrolyte membrane 1100 to surround the second electrode 1220.

[0103] The first subgasket 1310 and the second subgasket 1320: (i) prevent damage to the edge portion of the polymer electrolyte membrane 1100 due to repeated expansion and contraction of the fuel cell during operation; (ii) remedy the poor processing performance of the membrane electrode assembly 1000 due to the extremely thin polymer electrolyte membrane 1100; and (iii) prevent leakage of gas (i.e., hydrogen and air). Each of the first subgasket 1310 and the second subgasket 1320 can be a film including a polyimide (PI)-based compound, a polyethylene (PE)-based compound, a polypropylene (PP)-based compound, a polyethylene terephthalate (PET)-based compound, a fluorinated ethylene propylene (FEP)-based compound, or a mixture of two or more thereof. However, the present disclosure is not limited thereto.

[0104] like Figure 6 As shown in , the fuel cell according to the present disclosure may further include a first gas diffusion layer 1410 between the first electrode 1210 and the first separator 1510 and a second gas diffusion layer 1420 between the second electrode 1220 and the second separator 1520 .

[0105] The main functions of the first gas diffusion layer 1410 and the second gas diffusion layer 1420 are: (i) to provide a gas diffusion path from the first channel portion 1511 and the second channel portion 1521 in the first membrane 1510 and the second membrane 1520 to the first electrode 1210 and the second electrode 1220, so that gas (i.e., hydrogen and air) can be easily and uniformly supplied to the first electrode 1210 and the second electrode 1220; (ii) to enable water, which is a by-product of the oxygen reduction reaction, to be easily removed from the first electrode 1210 and the second electrode 1220, thereby preventing overflow; (iii) to store water to a certain extent, thereby preventing the moisture content of the polymer electrolyte membrane 1100 from suddenly decreasing; and (iv) to provide sufficient mechanical strength for the membrane-electrode assembly 1000.

[0106] Each of the first gas diffusion layer 1410 and the second gas diffusion layer 1420 may be a conductive porous member, such as carbon paper, carbon cloth, carbon felt, or metal cloth.

[0107] Hereinafter, the present disclosure will be described in detail with reference to specific examples. However, the following examples are given only to help understand the present disclosure and do not limit the scope of rights of the present disclosure.

[0108] Example 1

[0109] according to Figure 5a to Figure 5h The process shown in the figure is manufactured using the decal transfer method. Figure 1 The membrane-electrode assembly shown in (double-sided patterned cathode + conventional anode). The cathode was formed using a Pt / C catalyst (0.4 mg Pt / cm2 ) and anode (0.1 mg Pt / cm 2 ), and a fluorine-based polymer electrolyte membrane with a thickness of 18 μm was used.

[0110] Comparative Example 1

[0111] A conventional cathode and a conventional anode were formed on opposite surfaces of the polymer electrolyte membrane using a decal transfer method to obtain a membrane-electrode assembly. A cathode was formed using a Pt / C catalyst (0.4 mg Pt / cm 2 ) and anode (0.1 mg Pt / cm 2 ), and a fluorine-based polymer electrolyte membrane with a thickness of 18 μm was used.

[0112] Comparative Example 2

[0113] A single-sided patterned cathode and a conventional anode were formed on opposite surfaces of a polymer electrolyte membrane using a decal transfer method to obtain a membrane-electrode assembly. The patterned surface of the cathode was in contact with the polymer electrolyte membrane. A Pt / C catalyst was used to form the cathode (0.4 mg Pt / cm 2 ) and anode (0.1 mg Pt / cm 2 ), and a fluorine-based polymer electrolyte membrane with a thickness of 18 μm was used.

[0114] Comparative Example 3

[0115] A cathode composed of a plurality of sub-electrodes spaced apart from each other and a conventional anode were formed on opposite surfaces of the polymer electrolyte membrane to obtain a membrane-electrode assembly. The cathode was formed using a Pt / C catalyst (0.4 mg Pt / cm 2 ) and anode (0.1mgPt / cm 2 ), and a fluorine-based polymer electrolyte membrane with a thickness of 18 μm was used.

[0116] [Power performance evaluation]

[0117] The power performance of the membrane-electrode assembly was evaluated by IV measurement of the membrane-electrode assembly. Specifically, in order to examine the power performance under actual fuel cell operating conditions, the membrane-electrode assembly was fixed to a fuel cell unit cell evaluation device, and the temperature of the membrane-electrode assembly was maintained at 65°C. Hydrogen (100% RH) and air (100% RH) were supplied to the anode and cathode in amounts corresponding to the stoichiometric 1.2 / 2.0, respectively. The measurement applied 0.1A / cm 2 , 1A / cm 2 and 2A / cm 2 The results of the current density versus voltage are shown in Table 1 below. A higher measured voltage indicates better power performance.

[0118] In addition, the open circuit voltage (OCV) was measured and the results are shown in Table 1 below.

[0119] [Table 1]

[0120]

[0121] It can be seen that for Comparative Example 2, the interface area between the cathode and the polymer electrolyte membrane is increased, so that compared with Comparative Example 1, the interface area between the cathode and the polymer electrolyte membrane is increased in the active region (current density is 0.1 A / cm2) and the ohmic region (1 A / cm 2 ) power performance is improved. It can be seen that for Comparative Example 3, the cathode is formed using a plurality of sub-electrodes spaced apart from each other, so that the material transport resistance area (2 A / cm 2 ) power performance is improved. However, other regions (i.e., current density 0.1 A / cm 2 and 1A / cm 2 ) is not much different from that in Comparative Example 1. In addition, Comparative Example 3 exhibits lower OCV than Comparative Example 1. The reason is that the hydrogen permeability increases due to the exposure of the polymer electrolyte membrane between the sub-electrodes.

[0122] It can be seen that Example 1 exhibits the highest OCV due to its low gas permeability, while having all the positive effects of Comparative Examples 2 and 3.

[0123] [Cyclic Voltammetry (CV) & Linear Sweep Voltammetry (LSV)]

[0124] In the CV curve obtained by cyclic voltammetry (CV), the electrochemical surface area (ECA) of the cathode of the membrane-electrode assembly was calculated using the area values ​​of the hydrogen adsorption and desorption regions, and the results are shown in the following Table 2. In addition, the hydrogen permeability was indirectly examined by linear sweep voltammetry (LSV), and the results are shown in the following Table 2.

[0125] [Table 2]

[0126] <![CDATA[ECA(m 2 / g)]]> <![CDATA[H2 Permeability (mA / cm 2 )(@ 0.2V)]]> Example 1 35 1.72 Comparative Example 1 29 1.7 Comparative Example 2 34 1.75 Comparative Example 3 28 1.91

[0127] It can be seen that for Comparative Example 2, the interface area between the cathode and the polymer electrolyte membrane increases, so that the electrochemical surface area (ECA) increases compared to Comparative Example 1, and the hydrogen permeability increases compared to Comparative Example 1.

[0128] It can be seen that for Comparative Example 3, the cathode is formed using a plurality of sub-electrodes spaced apart from each other, so that the electrochemical surface area (ECA) is reduced compared to Comparative Example 1. In addition, Comparative Example 3 exhibits a much higher hydrogen permeability than Comparative Example 1.

[0129] It can be seen that for Example 1, the electrochemical surface area (ECA) increases the most compared to Comparative Example 1, and the hydrogen permeability increases only slightly compared to Comparative Example 1.

Claims

1. A membrane-electrode assembly, comprising: a first electrode; a second electrode; and a polymer electrolyte membrane between the first electrode and the second electrode, wherein The first electrode has a first surface facing the polymer electrolyte membrane and a second surface opposite to the first surface, The first surface has a first patterned structure, The second surface has a second patterned structure, and The first patterned structure has a plurality of protrusions, each having a diameter of a circumscribed circle of 10 μm to 1000 μm on its bottom surface, so that both the first electrode and the polymer electrolyte membrane have increased active areas, and the second patterned structure has at least one protrusion pattern extending in a direction parallel to the second surface and having a width of 10 μm to 1000 μm; and a concave pattern adjacent to the protrusion pattern, so that the non-channel portion of the diaphragm arranged on the second patterned structure corresponds only to the concave pattern of the second patterned structure.

2. The membrane-electrode assembly according to claim 1, wherein: The first electrode includes an intermediate layer between the first patterned structure and the second patterned structure, and The thickness of the intermediate layer is 10% to 90% of the thickness of the first electrode.

3. The membrane-electrode assembly according to claim 1, wherein: The protrusions are dispersed over the entire area of ​​the first surface.

4. The membrane-electrode assembly according to claim 3, wherein: The height of each of the protrusions is 1 μm to 50 μm.

5. The membrane-electrode assembly according to claim 1, wherein: The height of the protrusion pattern is 1 μm to 50 μm.

6. The membrane-electrode assembly according to claim 1, wherein: The second patterned structure includes a plurality of protrusion patterns arranged parallel to each other.

7. The membrane-electrode assembly according to claim 1, wherein: The convex pattern has a zigzag shape.

8. The membrane-electrode assembly according to claim 1, wherein: The first electrode is a cathode, and The second electrode is an anode.

9. A method for manufacturing a membrane-electrode assembly, the method comprising: applying a catalyst dispersion to a first release film having a first debossed pattern; covering the applied catalyst dispersion with a second release film having a second debossed pattern or a plurality of holes; drying at least a surface of the catalyst dispersion to form an electrode having a first patterned structure formed on a first surface thereof by the second release film and a second patterned structure formed on a second surface thereof by the first release film; removing the second release film; transferring the electrode to a polymer electrolyte membrane in such a manner that a first surface of the electrode faces the polymer electrolyte membrane; and removing the first release film, Wherein, the first patterned structure has a plurality of protrusions, each having a diameter of a circumscribed circle of 10 μm to 1000 μm on its bottom surface, so that both the electrode and the polymer electrolyte membrane have an increased active area, and the second patterned structure has at least one protrusion pattern extending in a direction parallel to the second surface and having a width of 10 μm to 1000 μm; and a concave pattern adjacent to the protrusion pattern, so that the non-channel portion of the diaphragm arranged on the second patterned structure corresponds only to the concave pattern of the second patterned structure.

10. The method according to claim 9, wherein: The first concave pattern of the first release film includes at least one groove extending in a direction parallel to a surface of the first release film and corresponding to the convex pattern of the second patterned structure, and The depth of the groove is 1 μm to 50 μm.

11. The method according to claim 9, wherein: The second release film has the plurality of holes corresponding to the plurality of protrusions of the first patterned structure.

12. The method according to claim 11, wherein: The thickness of the second release film is 10 μm to 100 μm, and Each of the holes has a diameter of 10 μm to 1000 μm. 13 . The method according to claim 9 , further comprising drying the electrode immediately after removing the second release film.

14. A fuel cell comprising: A membrane-electrode assembly, comprising: a first electrode; a second electrode; and a polymer electrolyte membrane between the first electrode and the second electrode, wherein the first electrode has a first surface facing the polymer electrolyte membrane and a second surface opposite to the first surface, the first surface has a first patterned structure, and the second surface has a second patterned structure; and A diaphragm disposed on the second patterned structure of the first electrode, wherein: The second patterned structure includes: at least one protruding pattern extending in a direction parallel to the first surface and the second surface and having a width of 10 μm to 1000 μm; and a concave pattern adjacent to the protruding pattern, The separator has a third surface facing the membrane-electrode assembly and a fourth surface opposite to the third surface, The third surface includes: a groove-shaped channel portion used as a fluid path; and a non-channel portion, The membrane-electrode assembly is aligned with the separator so that the non-channel portion of the separator corresponds only to the concave pattern of the second patterned structure, and The first patterned structure has a plurality of protrusions, each having a diameter of a circumscribed circle of 10 μm to 1000 μm on a bottom surface thereof, so that both the first electrode and the polymer electrolyte membrane have increased active areas.

15. The fuel cell according to claim 14, wherein The protrusion pattern of the second patterned structure has the same shape as the channel portion.

16. The fuel cell according to claim 15, wherein A width of the protruding patterns of the second patterned structure is not greater than a width of the channel portion.

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