Membrane for fuel cell and fuel cell including the membrane

Abstract

The present application relates to a diaphragm for a fuel cell and a fuel cell including the diaphragm. The fuel cell includes a diaphragm. A constant amount of air is supplied to the fuel cell regardless of the position within the air channel, and thus, degradation of the fuel cell is prevented. The diaphragm includes: a diaphragm body; and a porous structure having a plurality of pores defined therein to provide a path for fluid flow, wherein the diaphragm body includes: a fluid inlet portion having a space into which the fluid is introduced; a reaction region configured to receive the fluid; and a diffusion portion disposed between the fluid inlet portion and the reaction region, wherein the porous structure is stacked on one surface of the reaction region, and the number of pores per unit volume of the porous structure varies in the inlet region.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0036275, filed on March 25, 2020, which is hereby incorporated by reference herein. Technical Field

[0003] Example embodiments relate to a membrane for a fuel cell and a fuel cell including the membrane. Background Art

[0004] A fuel cell that generates electricity by reacting fuel (e.g., hydrogen) with air typically includes a membrane electrode assembly (MEA) comprising a membrane, a fuel electrode, and an air electrode; a gas diffusion layer in which the fuel and air diffuse; and a separator. In this configuration, the separator is positioned facing each of the fuel electrode and the air electrode, and serves to discharge water generated by the reactions within the fuel cell to the outside, while supplying fuel and air from the outside and providing a path through which current generated by the reactions within the fuel cell can flow.

[0005] Here, in the diaphragm, an air channel serving as a path for air to flow therethrough and a fuel channel serving as a path for fuel to flow therethrough are provided, and a manifold for supplying external fuel and air to the fuel channel and the air channel, respectively, is provided.

[0006] However, according to related art, the amount of air supplied is uneven between areas of the air passage relatively close to the manifold and areas of the air passage relatively far from the manifold. In this case, air is supplied more smoothly to areas of the air passage relatively close to the air supply manifold, and as a result, the electrochemical reaction of the MEA occurs more actively in this area compared to other areas. As a result, fuel cell degradation occurs earlier in areas adjacent to the air supply manifold. Specifically, this degradation occurs more severely in areas most directly supplied with air from the manifold. For example, according to related art, fuel cell degradation occurs most severely in the area closest to the manifold in the inlet area of ​​the air passage. Summary of the Invention

[0007] Exemplary embodiments of the present disclosure supply a constant amount of air to a fuel cell regardless of a position within an air passage to prevent degradation of the fuel cell.

[0008] A first aspect of the present disclosure provides a membrane for a fuel cell, the membrane comprising: a membrane body; and a porous structure stacked on one surface of the membrane body and having a plurality of pores defined therein to provide a path for fluid to flow through, wherein the membrane body comprises: a fluid inlet portion having a space into which a fluid is introduced; a reaction region configured to receive a fluid; and a diffusion portion arranged between the fluid inlet portion and the reaction region and having a passage to provide a path through which the fluid in the fluid inlet portion is supplied to the reaction region, wherein the porous structure is stacked on one surface of the reaction region, and the number of pores per unit volume of the porous structure in an inlet region (A1, hereinafter referred to as "the closest inlet region (A1)" or the first inlet region) of the fluid inlet portion closest to the inlet region of the porous structure facing the diffusion portion is less than the number of pores per unit volume of the porous structure in a second inlet region other than the first inlet region / closest inlet region (A1) among the inlet regions of the porous structure facing the diffusion portion.

[0009] The number of pores per unit volume of the porous structure in the inlet region of the porous structure may be smaller than the number of pores per unit volume of the porous structure in other regions except for the inlet region in the porous structure.

[0010] The fluid may be air.

[0011] The reaction area may include a first reaction area and a second reaction area, and the porous structure may include: a first porous structure stacked on a surface of the first reaction area; and a second porous structure stacked on a surface of the second reaction area, wherein the first reaction area and the second reaction area are arranged so that the distance between the first reaction area and the fluid inlet portion is smaller than the distance between the second reaction area and the fluid inlet portion, and the number of pores per unit volume in the inlet area of ​​the first porous structure is smaller than the number of pores per unit volume in the inlet area of ​​the second porous structure.

[0012] The reaction area may also include a third reaction area, and the porous structure may also include a third porous structure stacked on a surface of the third reaction area, wherein the third reaction area is arranged so that the distance between the second reaction area and the fluid inlet portion is less than the distance between the third reaction area and the fluid inlet portion, and the number of pores per unit volume of the third porous structure is constant over all areas of the third porous structure.

[0013] In other regions except for the inlet regions of the first to third porous structures, the numbers of pores per unit volume of the first to third porous structures may be the same as each other.

[0014] A second aspect of the present disclosure provides a diaphragm for a fuel cell, the diaphragm comprising: a diaphragm body; and a porous structure stacked on one surface of the diaphragm body and having a plurality of pores defined therein to provide a path for fluid to flow through, wherein the diaphragm body comprises: a fluid inlet portion having a space into which a fluid is introduced; a reaction region configured to receive a fluid; and a diffusion portion arranged between the fluid inlet portion and the reaction region and having a passage to provide a path through which the fluid in the fluid inlet portion is supplied to the reaction region, wherein the porous structure is stacked on one surface of the reaction region, and an inlet region (F1, hereinafter referred to as "inlet region (F1) at the same height" or a first inlet region) arranged at the same height as the fluid inlet portion in a height direction (h) in the inlet region of the porous structure facing the diffusion portion, the inlet region being arranged closer to a central region of the porous structure than a second inlet region other than the first inlet region / inlet region (F1) at the same height in the inlet region of the porous structure facing the diffusion portion.

[0015] When the inlet region is closer to the fluid inlet portion in the height direction (h) of the fluid inlet portion, the inlet region of the porous structure may be closer to the central region of the porous structure.

[0016] The boundary of the outlet region of the porous structure provided on the opposite side of the inlet region of the porous structure may extend in a direction perpendicular to the direction in which the porous structure extends from the inlet region to the outlet region.

[0017] The reaction area may include a first reaction area and a second reaction area, and the porous structure may include: a first porous structure stacked on a surface of the first reaction area; and a second porous structure stacked on a surface of the second reaction area, wherein the first reaction area and the second reaction area are arranged so that the height difference between the first reaction area and the fluid inlet portion is smaller than the height difference between the second reaction area and the fluid inlet portion, and the distance between the inlet area of ​​the first porous structure and the fluid inlet portion is the same as the distance between the inlet area of ​​the second porous structure and the fluid inlet portion.

[0018] A third aspect of the present disclosure provides a diaphragm for a fuel cell, the diaphragm comprising: a diaphragm body; and a porous structure stacked on one surface of the diaphragm body and having a plurality of pores defined therein to provide a path for fluid to flow through, wherein the diaphragm body comprises: a fluid inlet portion having a space into which a fluid is introduced; a reaction region configured to receive a fluid; and a diffusion portion arranged between the fluid inlet portion and the reaction region and having a passage to provide a path through which the fluid in the fluid inlet portion is supplied to the reaction region, wherein the porous structure is stacked on one surface of the reaction region, and a passage forming region (D1) of the passage facing the diffusion portion is arranged in an inlet region (A1, hereinafter referred to as "the closest inlet region (A1)" or the first inlet region), the passage forming region being closest to the fluid inlet portion in the inlet region facing the diffusion portion, and a pore forming region (D2) having a porous pore structure is arranged in a second inlet region other than the first inlet region / passage forming inlet region (D1).

[0019] When the passage forming region (D1) is closer to the fluid inlet portion in the height direction of the fluid inlet portion, the passage forming region (D1) of the porous structure may have a shape that protrudes toward the central region of the porous structure.

[0020] The reaction area may include a first reaction area and a second reaction area, and the porous structure may include: a first porous structure stacked on a surface of the first reaction area; and a second porous structure stacked on a surface of the second reaction area, wherein the first reaction area and the second reaction area are arranged so that the distance between the first reaction area and the fluid inlet portion is smaller than the distance between the second reaction area and the fluid inlet portion, and the passage forming area (D1) arranged in the inlet area of ​​the first porous structure has a shape that further protrudes from the passage forming area (D1) set in the inlet area of ​​the second porous structure toward the central area of ​​the porous structure.

[0021] A fourth aspect of the present disclosure provides a fuel cell, comprising: a membrane electrode assembly (MEA), the membrane electrode assembly comprising a membrane, a fuel electrode, and an air electrode; a gas diffusion layer stacked on one surface of the MEA; and a diaphragm stacked on one surface of the gas diffusion layer, wherein the diaphragm comprises: a diaphragm body; and a porous structure stacked on one surface of the diaphragm body and having a plurality of pores defined therein to provide a path for a fluid to flow through, wherein the diaphragm body comprises: a fluid inlet portion having a space into which a fluid is introduced; a reaction region configured to receive a fluid; and a diffusion portion. , the diffusion portion is arranged between the fluid inlet portion and the reaction area and has a passage to provide a path for the fluid in the fluid inlet portion to be supplied to the reaction area through the passage, wherein the porous structure is stacked on one surface of the reaction area, and the number of pores per unit volume of the porous structure in the inlet area (A1, hereinafter referred to as "the closest inlet area (A1)" or the first inlet area) closest to the fluid inlet portion in the inlet area of ​​the porous structure facing the diffusion portion is smaller than the number of pores per unit volume of the porous structure in the second inlet area other than the first inlet area / closest inlet area (A1) among the inlet areas of the porous structure facing the diffusion portion.

[0022] A fifth aspect of the present disclosure provides a fuel cell, comprising: a membrane electrode assembly (MEA), the membrane electrode assembly comprising a membrane, a fuel electrode and an air electrode; a gas diffusion layer, the gas diffusion layer being stacked on one surface of the MEA; and a diaphragm, the diaphragm being stacked on one surface of the gas diffusion layer, wherein the diaphragm comprises: a diaphragm body; and a porous structure, the porous structure being stacked on one surface of the diaphragm body and having a plurality of pores defined therein to provide a path for a fluid to flow through, wherein the diaphragm body comprises: a fluid inlet portion having a space into which a fluid is introduced; a reaction region, the reaction region being configured to receive a fluid; and a diffusion portion, the diffusion portion A porous structure is provided between a fluid inlet portion and a reaction area and has a passage to provide a path through which the fluid in the fluid inlet portion is supplied to the reaction area, wherein the porous structure is stacked on one surface of the reaction area, and an inlet area (F1, hereinafter referred to as "inlet area (F1) at the same height" or a first inlet area) is provided at the same height as the fluid inlet portion in the height direction (h) in the inlet area of ​​the porous structure facing the diffuser, and the inlet area is provided closer to the central area of ​​the porous structure than the second inlet area other than the first inlet area / inlet area (F1) at the same height in the inlet area of ​​the porous structure facing the diffuser. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

[0024] Figure 1 is a plan view illustrating the structure of a separator for a fuel cell according to a first exemplary embodiment of the present disclosure.

[0025] Figure 2 is an enlarged perspective view of a porous structure and a configuration around the porous structure in a fuel cell equipped with the separator for a fuel cell according to the first exemplary embodiment of the present disclosure.

[0026] Figure 3 is a plan view illustrating a structure of a separator for a fuel cell according to a second exemplary embodiment of the present disclosure.

[0027] Figure 4 is a plan view illustrating a structure of a separator for a fuel cell according to a third exemplary embodiment of the present disclosure.

[0028] Figure 5 is a cross-sectional view showing a stack structure of a fuel cell according to one example of the present disclosure. DETAILED DESCRIPTION

[0029] It should be understood that the term "vehicle" or "vehicular" or other similar terms used herein generally include motor vehicles (such as passenger cars including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles), watercraft including various boats and ships, etc., and include electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As described herein, a hybrid vehicle is a vehicle having two or more power sources, for example, both a gasoline-powered vehicle and an electric vehicle.

[0030] The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the present disclosure. As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It should be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of the features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more related listed items. Throughout this specification, unless explicitly described to the contrary, the word "comprise" and variations such as "comprises" or "comprising" will be understood to imply the inclusion of the elements described, but not the exclusion of any other elements. In addition, the terms "unit", "-device", "-machine", and "module" described in the specification mean a unit for processing at least one function and operation, and can be implemented by hardware components or software components and combinations thereof.

[0031] Furthermore, the control logic of the present disclosure may be embodied as a non-transitory computer-readable medium on a computer-readable medium containing executable program instructions executed by a processor, controller, or the like. Examples of computer-readable media include, but are not limited to, ROM, RAM, compact disk (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards, and optical data storage devices. The computer-readable medium can also be distributed among network-coupled computer systems so that the computer-readable medium is stored and executed in a distributed manner, for example, by a telematics server or a controller area network (CAN).

[0032] Hereinafter, a separator for a fuel cell and a fuel cell including the separator according to the present disclosure will be described with reference to the accompanying drawings.

[0033] Figure 1 is a plan view showing the structure of a separator for a fuel cell according to a first exemplary embodiment of the present disclosure, and Figure 2 is an enlarged perspective view of a porous structure and a configuration around the porous structure in a fuel cell equipped with the separator for a fuel cell according to the first exemplary embodiment of the present disclosure.

[0034] like Figure 1 As shown, a membrane for a fuel cell according to the present disclosure (hereinafter, referred to as a membrane 10 ) may include a membrane body 100 .

[0035] The diaphragm body 100 may include: a fluid inlet portion 110 having a space into which a fluid is introduced; a reaction area 130 for receiving the fluid from the fluid inlet portion 110; and a diffusion portion 120, which is arranged between the fluid inlet portion 110 and the reaction area 130 and has a passage to provide a path for the fluid in the fluid inlet portion 110 supplied to the reaction area 130 to pass through.

[0036] like Figure 2 As shown, according to the present disclosure, a reaction surface 20 including an electrode is provided in a fuel cell, and the reaction surface 20 may have a structure stacked on one surface of a reaction region 130 of the diaphragm 10. The fluid supplied to the fluid inlet portion 110 is supplied to the reaction region 130 via the diffuser 120, and then, the fluid supplied to the reaction region 130 is again supplied to the reaction surface 20 including the electrode. An electrochemical reaction may occur on the reaction surface 20 by the fluid supplied to the reaction surface 20, thereby generating current in the fuel cell.

[0037] Here, the fluid may be air. Therefore, the fluid introduced into the fluid inlet portion 110 may also be air. In addition, in addition to air, a fuel (e.g., hydrogen) may also be introduced into the diaphragm 10. Therefore, the fuel cell according to the present disclosure may be configured to generate current through a reaction between hydrogen and oxygen in the air.

[0038] Here, as Figure 2 As shown, in the membrane 10 according to the present disclosure, the porous structure 200 may be stacked on one surface of the membrane body 100. Specifically, the porous structure 200 may be stacked on one surface of the reaction region 130.

[0039] The porous structure 200 has a plurality of holes defined therein to provide a path through which a fluid supplied to the reaction area 130 flows, and also has a function of changing a passage of the fluid supplied to the reaction area 130 and supplying the fluid to the reaction surface 20 .

[0040] That is, the fluid introduced into the reaction region 130 flows through the pores provided in the porous structure 200 and collides with the structure of the main body provided with the porous structure 200. The moving direction of the fluid colliding with the structure of the main body provided with the porous structure 200 may be changed to a direction toward the reaction surface 20. The fluid whose moving direction has been changed is supplied to the reaction surface 20, and thus, an electrochemical reaction may occur on the reaction surface 20.

[0041] Moreover, reference Figure 1, the reaction region 130 provided in the diaphragm 10 may have a plurality of regions. For example, the reaction region 130 may include a first reaction region 130a, a second reaction region 130b, and a third reaction region 130c. Here, Figure 1 The state where the first to third reaction regions 130a, 130b, and 130c are separated from each other is shown. However, unlike this configuration, a plurality of reaction regions including the first to third reaction regions 130a, 130b, and 130c may be connected to each other and integrated.

[0042] Furthermore, as described above, the porous structure 200 may be stacked on one surface of the reaction region 130, and the reaction region 130 may include the first to third reaction regions 130a, 130b, and 130c. Therefore, the porous structure 200 may include a first porous structure stacked on one surface of the first reaction region 130a, a second porous structure stacked on one surface of the second reaction region 130b, and a third porous structure stacked on one surface of the third reaction region 130c. The first to third porous structures may be separated from each other, but unlike this configuration, the first to third porous structures may be connected to each other and integrated.

[0043] Also, the first to third reaction regions 130a, 130b, and 130c may be arranged in one direction based on the distance from the fluid inlet portion 110. That is, as Figure 1 As shown, the first reaction region 130a and the second reaction region 130b may be arranged such that the distance between the first reaction region 130a and the fluid inlet portion 110 is smaller than the distance between the second reaction region 130b and the fluid inlet portion 110. Furthermore, the second reaction region 130b and the third reaction region 130c may be arranged such that the distance between the second reaction region 130b and the fluid inlet portion 110 is smaller than the distance between the third reaction region 130c and the fluid inlet portion 110.

[0044] According to one aspect of the present disclosure, the density of pores defined in the porous structure 200 provided in the diaphragm 10 can be varied depending on the location. That is, according to the first exemplary embodiment, when the region of the porous structure 200 facing the diffuser 120 is referred to as the "inlet region E1" and the inlet region A1 closest to the inlet region E1 of the fluid inlet portion 110 is referred to as the "closest inlet region," the number of pores per unit volume of the porous structure 200 in the closest inlet region A1 can be smaller than the number of pores per unit volume of the porous structure 200 in inlet regions other than the closest inlet region A1 in the inlet region E1 of the porous structure 200. A small number of pores per unit volume can be understood as a large average size of the pores.

[0045] According to the related art, the closest inlet region A1 of the porous structure 200 is closest to the fluid inlet portion 110, and therefore, a large amount of fluid discharged from the fluid inlet portion 110 can be supplied to the closest inlet region A1 and the reaction region facing the closest inlet region A1 of the porous structure 200. However, in this case, in the closest inlet region A1, a large amount of fluid is supplied to the reaction surface due to collision with the porous structure 200, and therefore, the electrochemical reaction seriously occurs on the reaction surface facing the closest inlet region A1, which causes degradation.

[0046] According to the first exemplary embodiment of the present disclosure, the number of pores per unit volume of the porous structure 200 in the closest inlet region A1 of the porous structure 200 is relatively small, and therefore, as shown in FIG. Figure 2 As shown, the structure of the main body provided with the porous structure 200 has a relatively low density in the closest inlet area A1. Therefore, the collision frequency between the porous structure 200 and the fluid (i.e., air) supplied to the reaction area 130 that passes through the closest inlet area A1 of the porous structure 200 is reduced, and therefore, the amount of fluid supplied to the reaction surface 20 is also reduced. Therefore, relatively few electrochemical reactions occur in the reaction surface 20 facing the closest inlet area A1. That is, according to the present disclosure, degradation can be prevented from occurring on the reaction surface 20 facing the closest inlet area A1 of the porous structure 200. Here, as Figure 1 As shown, in the case where each of the reaction region 130 and the porous structure 200 is divided into a plurality of regions, the closest inlet region A1 of the porous structure 200 may be provided in a region facing the first reaction region 130a. On the other hand, in the case where each of the reaction region 130 and the porous structure 200 is integrated into one region, the closest inlet region A1 of the porous structure 200 may be defined as a region horizontally facing the inlet region E1 of the fluid inlet portion 110, which is a reference region. Figure 1 The upper area of ​​the entrance area E1.

[0047] Here, according to the first exemplary embodiment of the present disclosure, the number of pores per unit volume in the inlet region E1 of the porous structure 200 may be smaller than the number of pores per unit volume of the porous structure 200 in other regions except the inlet region E1 in the porous structure 200 .

[0048] As described above, degradation of the fuel cell including the reaction surface 20 may most frequently occur around the closest inlet area A1 of the porous structure 200, but degradation may also occur relatively easily in the inlet area E1 of the porous structure 200 that directly receives the fluid from the fluid inlet portion 110, compared to other areas of the porous structure 200. Therefore, according to the first exemplary embodiment of the present disclosure, since the number of pores per unit volume in the inlet area E1 of the porous structure 200 is relatively small, degradation can be prevented from occurring on the reaction surface 20 facing the inlet area E1 of the porous structure 200.

[0049] Moreover, according to the first exemplary embodiment of the present disclosure, even within the inlet region E1 of the porous structure 200, the number of pores per unit volume can be different from each other. For example, the number of pores per unit volume in the inlet region of the first porous structure arranged to face the first reaction region 130a can be smaller than the number of pores per unit volume in the inlet region of the second porous structure arranged to face the second reaction region 130b. On the other hand, the number of pores per unit volume of the third porous structure arranged to face the third reaction region 130c can be constant across all regions of the third porous structure. As described above, the number of pores per unit volume is configured to vary across the region of the porous structure 200 because degradation can relatively easily occur on the reaction surface 20 of the region facing the inlet region E1 of the porous structure 200 adjacent to the fluid inlet portion 110, but relatively less degradation occurs on the reaction surface 20 of the region facing the inlet region E1 of the porous structure 200 away from the fluid inlet portion 110.

[0050] Furthermore, according to the first exemplary embodiment of the present disclosure, in other regions except the inlet region E1 of the porous structure 200, the number of pores per unit volume of the porous structure 200 may be the same as each other. Figure 1 , in other regions except for the inlet regions of the first to third porous structures, the numbers of pores per unit volume of the first to third porous structures may be the same as each other.

[0051] Figure 3 is a plan view illustrating a structure of a separator for a fuel cell according to a second exemplary embodiment of the present disclosure.

[0052] Similar to the first exemplary embodiment of the present disclosure, a separator for a fuel cell according to a second exemplary embodiment of the present disclosure (hereinafter, referred to as a separator 10) may include a separator body 100, such as Figure 3 shown.

[0053] In addition, the diaphragm body 100 may include: a fluid inlet portion 110 having a space into which a fluid is introduced; a reaction area 130 for receiving the fluid from the fluid inlet portion 110; and a diffusion portion 120, which is arranged between the fluid inlet portion 110 and the reaction area 130 and has a passage to provide a path for the fluid in the fluid inlet portion 110 supplied to the reaction area 130 to pass through.

[0054] Moreover, in the diaphragm 10 according to the second exemplary embodiment of the present disclosure, the porous structure 200 may be stacked on one surface of the diaphragm body 100. Specifically, the porous structure 200 may be stacked on one surface of the reaction region 130. The description of both the content that the fluid supplied to the fluid inlet portion 110 is supplied to the reaction region 130 via the diffusion portion 120 and the principle that the fluid supplied to the reaction region 130 is supplied to the reaction surface including the electrode will be replaced with the above description of the diaphragm according to the first exemplary embodiment of the present disclosure.

[0055] Moreover, even in the diaphragm 10 according to the second exemplary embodiment of the present disclosure, the reaction region 130 provided in the diaphragm 10 may have a Figure 3 For example, the reaction region 130 may include a first reaction region 130a, a second reaction region 130b, and a third reaction region 130c. Here, Figure 3 The state where the first to third reaction regions 130a, 130b, and 130c are separated from each other is shown. However, unlike this configuration, a plurality of reaction regions including the first to third reaction regions 130a, 130b, and 130c may be connected to each other and integrated.

[0056] Furthermore, as described above, the porous structure 200 may be stacked on one surface of the reaction region 130, and the reaction region 130 may include the first to third reaction regions 130a, 130b, and 130c. Therefore, the porous structure 200 may include a first porous structure stacked on one surface of the first reaction region 130a, a second porous structure stacked on one surface of the second reaction region 130b, and a third porous structure stacked on one surface of the third reaction region 130c. The first to third porous structures may be separated from each other, but unlike this configuration, the first to third porous structures may be connected to each other and integrated.

[0057] Also, the first to third reaction regions 130a, 130b, and 130c may be arranged in one direction based on the distance from the fluid inlet portion 110. That is, as Figure 3As shown, the first reaction region 130a and the second reaction region 130b may be arranged such that the distance between the first reaction region 130a and the fluid inlet portion 110 is smaller than the distance between the second reaction region 130b and the fluid inlet portion 110. In addition, the second reaction region 130b and the third reaction region 130c may be arranged such that the distance between the second reaction region 130b and the fluid inlet portion 110 is smaller than the distance between the third reaction region 130c and the fluid inlet portion 110.

[0058] According to another aspect of the present disclosure, some regions of the porous structure 200 of the diaphragm 10 have a shape that is curved in a direction opposite to the direction facing the fluid inlet portion 110, compared to other regions. That is, according to the second exemplary embodiment of the present disclosure, when the region of the porous structure 200 facing the diffuser 120 is referred to as "inlet region E1," and the inlet region of the inlet region E1 located at the same height as the fluid inlet portion 110 in the height direction h is referred to as "inlet region F1 at the same height," the inlet region F1 at the same height of the porous structure 200 may be positioned closer to the central region of the porous structure than regions other than the inlet region F1 at the same height among the inlet regions of the porous structure 200. More preferably, when the inlet region E1 is closer to the fluid inlet portion 110 in the height direction (h) of the fluid inlet portion 110, the inlet region E1 of the porous structure 200 may be closer to the central region E3 of the porous structure 200.

[0059] According to the second exemplary embodiment of the present disclosure, inlet regions F1 at the same height of the porous structure 200 are shaped closer to the central region E3 of the porous structure 200. This increases the distance between the inlet regions F1 at the same height of the porous structure 200 and the fluid inlet portion 110 compared to the related art. Consequently, the amount of fluid supplied to the inlet regions F1 at the same height of the porous structure 200 is reduced, and thus, degradation of the reaction surface facing the inlet regions F1 at the same height can be prevented. Specifically, according to a further preferred exemplary embodiment, when the inlet regions E1 are closer to the fluid inlet portion 110 in the height direction h of the fluid inlet portion 110, the inlet regions E1 of the porous structure 200 are shaped closer to the central region E3. Consequently, degradation of the reaction surface facing the inlet regions E1 of the porous structure 200, which is relatively close to the fluid inlet portion 110, can be prevented compared to the related art.

[0060] Moreover, according to Figure 3In the present disclosure shown, the outlet region E2 through which the supplied fluid is discharged may be provided on the opposite side of the inlet region E1 of the porous structure 200. Here, according to the present disclosure, the boundary of the outlet region E2 in the porous structure 200 may extend in a direction perpendicular to the direction in which the porous structure 200 extends from the inlet region E1 to the outlet region E2. This can be understood as the boundary of the porous structure 200 in the outlet region E2 not having a curved shape or a concave shape, but having a straight shape.

[0061] Furthermore, according to the second exemplary embodiment, the distance between the fluid inlet portion 110 and the inlet region of the first porous structure disposed facing the first reaction region 130a may be the same as the distance between the fluid inlet portion 110 and the inlet region of the second porous structure. In this case, the movement distance of the fluid supplied from the fluid inlet portion 110 to the first reaction region 130a and the first porous structure is the same as the movement distance of the fluid supplied from the fluid inlet portion 110 to the second reaction region 130b and the second porous structure, and thus, it is possible to prevent the occurrence of degradation on the reaction region facing the inlet region F1 at the same height due to the fluid being concentratedly supplied to the inlet region closest to the fluid inlet portion 110 (i.e., the inlet region F1 at the same height).

[0062] Figure 4 is a plan view illustrating a structure of a separator for a fuel cell according to a third exemplary embodiment of the present disclosure.

[0063] Similar to the first and second exemplary embodiments of the present disclosure, a separator for a fuel cell according to a third exemplary embodiment of the present disclosure (hereinafter, referred to as a separator 10) may include a separator body 100, such as Figure 4 shown.

[0064] In addition, the diaphragm body 100 may include: a fluid inlet portion 110 having a space into which a fluid is introduced; a reaction area 130 for receiving the fluid from the fluid inlet portion 110; and a diffusion portion 120, which is arranged between the fluid inlet portion 110 and the reaction area 130 and has a passage to provide a path for the fluid in the fluid inlet portion 110 supplied to the reaction area 130 to pass through.

[0065] Moreover, in the diaphragm 10 according to the third exemplary embodiment of the present disclosure, the porous structure 200 may be stacked on one surface of the diaphragm body 100. Specifically, the porous structure 200 may be stacked on one surface of the reaction region 130. The description of both the content that the fluid supplied to the fluid inlet portion 110 is supplied to the reaction region 130 via the diffusion portion 120 and the principle that the fluid supplied to the reaction region 130 is supplied to the reaction surface including the electrode will be replaced with the above description of the diaphragm according to the first exemplary embodiment of the present disclosure.

[0066] Furthermore, even in the diaphragm 10 according to the third exemplary embodiment of the present disclosure, the reaction region 130 provided in the diaphragm 10 may have a Figure 4 For example, the reaction region 130 may include a first reaction region 130a, a second reaction region 130b, and a third reaction region 130c. Here, Figure 4 The state where the first to third reaction regions 130a, 130b, and 130c are separated from each other is shown. However, unlike this configuration, a plurality of reaction regions including the first to third reaction regions 130a, 130b, and 130c may be connected to each other and integrated.

[0067] Furthermore, as described above, the porous structure 200 may be stacked on one surface of the reaction region 130, and the reaction region 130 may include the first to third reaction regions 130a, 130b, and 130c. Therefore, the porous structure 200 may include a first porous structure stacked on one surface of the first reaction region 130a, a second porous structure stacked on one surface of the second reaction region 130b, and a third porous structure stacked on one surface of the third reaction region 130c. The first to third porous structures may be separated from each other, but unlike this configuration, the first to third porous structures may be connected to each other and integrated.

[0068] Also, the first to third reaction regions 130a, 130b, and 130c may be arranged in one direction based on the distance from the fluid inlet portion 110. That is, as Figure 4 As shown, the first reaction region 130a and the second reaction region 130b may be arranged such that the distance between the first reaction region 130a and the fluid inlet portion 110 is smaller than the distance between the second reaction region 130b and the fluid inlet portion 110. Furthermore, the second reaction region 130b and the third reaction region 130c may be arranged such that the distance between the second reaction region 130b and the fluid inlet portion 110 is smaller than the distance between the third reaction region 130c and the fluid inlet portion 110.

[0069] Here, according to the third exemplary embodiment of the present disclosure, the porous structure 200 of the diaphragm 10 may include not only a pore forming region having a plurality of pores but also a passage forming region provided in a region facing the passage provided in the diffusion portion 120 of the diaphragm body 100 .

[0070] That is, according to the third exemplary embodiment, the porous structure 200 may be stacked on one surface of the reaction area 130. When a region of the porous structure 200 facing the diffusion portion 120 is referred to as an "inlet region E1," and the inlet region E1 closest to the inlet region A1 of the fluid inlet portion 110 is referred to as a "closest inlet region," a passage forming region D1 provided as a passage facing the diffusion portion 120 may be provided in the closest inlet region A1 of the porous structure 200, and a pore forming region D2 having a porous pore structure may be provided in a region other than the passage forming region D1 in the porous structure 200. Figure 4 A state in which the passage forming area D1 is provided in a portion of the closest inlet area A1 is shown.

[0071] Here, according to the third exemplary embodiment, when the passage forming area D1 is closer to the fluid inlet portion 110 in the height direction h of the fluid inlet portion 110, the passage forming area D1 of the porous structure 200 may have a shape that protrudes toward the central area of ​​the porous structure 200. This can be understood as when the passage forming area D1 is closer to the fluid inlet portion 110 in the height direction h of the fluid inlet portion 110, the passage forming area D1 of the porous structure 200 may have a shape that curves toward the central area of ​​the porous structure 200.

[0072] As described above, according to the third exemplary embodiment, the passage forming region D1 may be provided in the closest inlet region A1 of the porous structure 200, and more preferably, when the passage forming region D1 is closer to the fluid inlet portion 110 in the height direction h of the fluid inlet portion 110, the passage forming region D1 of the porous structure 200 may have a shape that protrudes toward the central region of the porous structure 200. In this case, similar to the second exemplary embodiment, it is possible to prevent degradation on the reaction region facing the closest inlet region A1 due to the fluid being centrally supplied to the inlet region of the closest fluid inlet portion 110 (i.e., the closest inlet region A1) from occurring.

[0073] Furthermore, as described above, the reaction region 130 may include the first reaction region 130a and the second reaction region 130b, and the porous structure 200 may include a first porous structure stacked on one surface of the first reaction region 130a and a second porous structure stacked on one surface of the second reaction region 130b. Here, according to the third exemplary embodiment, the passage-forming region D1 provided in the inlet region of the first porous structure may have a shape that further protrudes from the passage-forming region D1 provided in the inlet region of the second porous structure toward the central region of the porous structure 200. Therefore, according to the third exemplary embodiment, the pore-forming region D2 provided in the first porous structure may have a shape that further curves from the pore-forming region D2 provided in the second porous structure toward the central region of the porous structure 200.

[0074] Figure 5 is a cross-sectional view showing a stack structure of a fuel cell according to one example of the present disclosure.

[0075] refer to Figure 5 A fuel cell according to the present disclosure may include: a membrane electrode assembly (MEA) 22 including a membrane, a fuel electrode, and an air electrode; a gas diffusion layer 24 stacked on one surface of the MEA 22; and a separator 10 stacked on one surface of the gas diffusion layer 24. The gas diffusion layer 24 may include an air diffusion layer 24a stacked on one surface of the MEA 22 and a fuel diffusion layer 24b stacked on the other surface of the MEA 22.

[0076] As described above, the diaphragm 10 may include a diaphragm body 100 and a porous structure 200, the porous structure 200 being stacked on one surface of the diaphragm body 100 and defining a plurality of pores therein to provide a path through which a fluid flows. Furthermore, as described above, the diaphragm body 100 may include: a fluid inlet portion 110 having a space into which a fluid is introduced; a reaction region 130 for receiving a fluid; and a diffusion portion 120 disposed between the fluid inlet portion 110 and the reaction region 130 and having a passage to provide a path through which the fluid in the fluid inlet portion 110 is supplied to the reaction region 130 (see Figure 1 、 Figure 3 and Figure 4 ). Moreover, the reaction surface 20 (see Figure 2 ) may include a MEA 22 and a gas diffusion layer 24 of a fuel cell according to the present disclosure.

[0077] Here, the shapes of the fluid inlet portion and the diffuser portion described and shown in this specification and the drawings are merely illustrative, and the present disclosure can be applied regardless of the specific shapes of the fluid inlet portion and the diffuser portion.

[0078] According to the present disclosure, a constant amount of air is supplied to the fuel cell regardless of the position within the air passage, and therefore, degradation of the fuel cell can be prevented.

[0079] Although the present disclosure has been described above through specific embodiments and drawings, the present disclosure is not limited thereto, and it is apparent that various changes and modifications can be made by those skilled in the art within the technical concept of the present disclosure and the equivalent scope of the appended claims.

Claims

1. A membrane for a fuel cell, comprising: diaphragm body; as well as a porous structure stacked on one surface of the diaphragm body and having a plurality of pores defined therein to provide a path for fluid to flow therethrough, Wherein, the diaphragm body comprises: a fluid inlet portion having a space into which the fluid is introduced; a reaction area configured to receive the fluid; and a diffusion portion provided between the fluid inlet portion and the reaction region and having a passage for providing a path through which the fluid in the fluid inlet portion is supplied to the reaction region, wherein the porous structure is stacked on one surface of the reaction area, and The number of pores per unit volume of the porous structure in a first inlet region closest to the fluid inlet region among the inlet regions of the porous structure facing the diffuser is smaller than the number of pores per unit volume of the porous structure in a second inlet region other than the first inlet region among the inlet regions of the porous structure facing the diffuser.

2. The diaphragm according to claim 1, wherein The number of pores per unit volume of the porous structure in the inlet region of the porous structure is smaller than the number of pores per unit volume of the porous structure in other regions except the inlet region in the porous structure.

3. The diaphragm according to claim 1, wherein The fluid is air. The diaphragm according to claim 1 , wherein: The reaction area includes a first reaction area and a second reaction area, and The porous structure comprises: a first porous structure stacked on one surface of the first reaction region; and a second porous structure, the second porous structure being stacked on one surface of the second reaction zone, wherein the first reaction region and the second reaction region are arranged such that the distance between the first reaction region and the fluid inlet portion is smaller than the distance between the second reaction region and the fluid inlet portion, and The number of pores per unit volume in the inlet region of the first porous structure is smaller than the number of pores per unit volume in the inlet region of the second porous structure.

5. The diaphragm according to claim 4, wherein The reaction zone further includes a third reaction zone, and The porous structure further includes a third porous structure stacked on one surface of the third reaction zone, wherein the third reaction zone is arranged such that the distance between the second reaction zone and the fluid inlet portion is smaller than the distance between the third reaction zone and the fluid inlet portion, and The number of pores per unit volume of the third porous structure is constant across all areas of the third porous structure. The diaphragm according to claim 5 , wherein: In other regions except the inlet region from the first porous structure to the third porous structure, The numbers of pores per unit volume of the first to third porous structures are the same as one another.

7. A membrane for a fuel cell, comprising: diaphragm body; as well as a porous structure stacked on one surface of the diaphragm body and having a plurality of pores defined therein to provide a path for fluid to flow therethrough, Wherein, the diaphragm body comprises: a fluid inlet portion having a space into which the fluid is introduced; a reaction area configured to receive the fluid; and a diffusion portion provided between the fluid inlet portion and the reaction region and having a passage for providing a path through which the fluid in the fluid inlet portion is supplied to the reaction region, wherein the porous structure is stacked on one surface of the reaction area, and a first inlet region provided closer to a central region of the porous structure than a second inlet region other than the first inlet region in the inlet region of the porous structure facing the diffuser, the first inlet region provided at the same height as the fluid inlet portion in a height direction in the inlet region of the porous structure facing the diffuser, and The number of pores per unit volume of the porous structure in a first inlet region closest to the fluid inlet region among the inlet regions of the porous structure facing the diffuser is smaller than the number of pores per unit volume of the porous structure in a second inlet region other than the first inlet region among the inlet regions of the porous structure facing the diffuser.

8. The diaphragm according to claim 7, wherein When the inlet region is closer to the fluid inlet portion in the height direction of the fluid inlet portion, the inlet region of the porous structure is closer to the central region of the porous structure.

9. The diaphragm according to claim 8, wherein Boundaries of the outlet region of the porous structure provided on opposite sides of the inlet region of the porous structure extend in a direction perpendicular to a direction in which the porous structure extends from the inlet region to the outlet region.

10. The diaphragm according to claim 7, wherein The reaction area includes a first reaction area and a second reaction area, and The porous structure comprises: a first porous structure stacked on one surface of the first reaction region; and a second porous structure, the second porous structure being stacked on one surface of the second reaction zone, wherein the first reaction region and the second reaction region are arranged such that a height difference between the first reaction region and the fluid inlet portion is smaller than a height difference between the second reaction region and the fluid inlet portion, and The distance between the inlet region of the first porous structure and the fluid inlet portion is the same as the distance between the inlet region of the second porous structure and the fluid inlet portion.

11. A membrane for a fuel cell, comprising: diaphragm body; as well as a porous structure stacked on one surface of the diaphragm body and having a plurality of pores defined therein to provide a path for fluid to flow therethrough, Wherein, the diaphragm body comprises: a fluid inlet portion having a space into which the fluid is introduced; a reaction area configured to receive the fluid; and a diffusion portion provided between the fluid inlet portion and the reaction region and having a passage for providing a path through which the fluid in the fluid inlet portion is supplied to the reaction region, wherein the porous structure is stacked on one surface of the reaction area, a passage forming region of the passage facing the diffuser portion is provided in a first inlet region, the passage forming region being closest to the fluid inlet portion in the inlet region of the porous structure facing the diffuser portion, and a pore forming region having a porous pore structure is provided in a second inlet region other than the first inlet region in the porous structure, The number of pores per unit volume of the porous structure in a first inlet region closest to the fluid inlet region among the inlet regions of the porous structure facing the diffuser is smaller than the number of pores per unit volume of the porous structure in a second inlet region other than the first inlet region among the inlet regions of the porous structure facing the diffuser.

12. The diaphragm according to claim 11, wherein The passage forming region of the porous structure has a shape that protrudes toward a central region of the porous structure when the passage forming region is closer to the fluid inlet portion in a height direction of the fluid inlet portion.

13. The diaphragm according to claim 11, wherein The reaction area includes a first reaction area and a second reaction area, and The porous structure comprises: a first porous structure stacked on one surface of the first reaction region, and a second porous structure, the second porous structure being stacked on one surface of the second reaction zone, wherein the first reaction region and the second reaction region are arranged such that the distance between the first reaction region and the fluid inlet portion is smaller than the distance between the second reaction region and the fluid inlet portion, and The passage forming region provided in the inlet region of the first porous structure has a shape that further protrudes from the passage forming region provided in the inlet region of the second porous structure toward a central region of the porous structure.

14. A fuel cell comprising: a membrane electrode assembly, the membrane electrode assembly comprising a membrane, a fuel electrode, and an air electrode; a gas diffusion layer stacked on one surface of the membrane electrode assembly; as well as The diaphragm according to claim 1, wherein the diaphragm is stacked on one surface of the gas diffusion layer.

15. A fuel cell comprising: a membrane electrode assembly, the membrane electrode assembly comprising a membrane, a fuel electrode, and an air electrode; a gas diffusion layer stacked on one surface of the membrane electrode assembly; as well as The diaphragm according to claim 7, wherein the diaphragm is stacked on one surface of the gas diffusion layer.

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