Unit cell for fuel cell

Abstract

A unit cell for a fuel cell according to an embodiment includes an anode separator, a cathode separator, a frame disposed between the anode separator and the cathode separator, a membrane electrode assembly, and a pair of gas diffusion layers respectively bonded to a first side and a second side of the membrane electrode assembly. The frame includes a plurality of films stacked together, a through hole provided at a center portion of the frame, a manifold hole provided at an edge portion of the frame, where the manifold hole is configured to allow fluid to flow therethrough, and slits provided in a plurality of first films of the plurality of films, the slits extending from the manifold hole toward the through hole and being cut to form fluid flow paths, wherein the membrane electrode assembly and the pair of gas diffusion layers are disposed in the through-hole in the frame.

Description

Technical Field

[0001] The present disclosure relates to a unit cell for a fuel cell. Background Art

[0002] A fuel cell is a type of generator that converts the chemical energy contained in the fuel into electrical energy through an electrochemical reaction in a battery stack. It can not only provide driving power for industry, household, construction, aviation, vehicles, etc., but can also be used to power small electronic products such as portable devices. In recent years, its application areas are gradually expanding to efficient and clean energy.

[0003] A unit cell of a typical fuel cell has a membrane electrode assembly (MEA) located innermost, which consists of a polymer electrolyte membrane capable of transporting hydrogen protons, and an anode and a cathode, which are electrodes arranged so that hydrogen and oxygen can react on both surfaces of the electrolyte membrane.

[0004] In addition, a gas diffusion layer (GDL) is stacked outside the membrane electrode assembly, that is, outside where the anode and cathode are located, and a separator is located outside the gas diffusion layer, and a flow field is formed on the separator to supply fuel and discharge water generated by the reaction.

[0005] The fuel cell stack is configured by stacking a plurality of unit cells having the above configuration in series so as to generate a desired output level from the fuel cell. The fuel cell stack has end plates coupled to the outermost sides of the unit cells to support and fix the plurality of unit cells.

[0006] Meanwhile, a power generation assembly (EGA) integrating a membrane electrode assembly and a gas diffusion layer is conventionally manufactured and applied to facilitate airtightness maintenance and a stacking process of unit cells.

[0007] In addition, a frame supporting EGA has recently been studied. The frame is made of engineering plastic (EP) to ensure heat resistance and is molded by injection molding. However, the frame is formed thin but has a complex structure, so when it is molded by injection molding, there is a problem that some areas are not molded to have a desired structure or are deformed due to thickness deviation or pressure deviation.

[0008] The discussion of the related art is only for obtaining a full understanding of the related art of the embodiments of the present invention, and it should not be understood as an admission that the related art belongs to the technology well known to ordinary technicians in the field. Summary of the invention

[0009] Embodiments of the present disclosure can solve the problems in the art, and the embodiments provide a unit cell for a fuel cell including a frame having a structure capable of minimizing thickness deviation or pressure deviation.

[0010] The technical objectives that can be achieved through the embodiments of the present disclosure are not limited to the above-mentioned technical objectives, and those skilled in the art can clearly understand other technical objectives not mentioned from the following description.

[0011] A unit cell for a fuel cell according to an embodiment of the present disclosure may include an anode separator, a cathode separator, and a frame arranged between the anode separator and the cathode separator and formed by stacking a plurality of membranes, wherein a through hole through which a membrane electrode assembly and a gas diffusion layer are combined is formed in a central portion of the frame, a manifold hole through which a fluid flows is formed at an edge portion of the frame, and slits extending from the manifold hole to the through hole and cut to form a fluid flow path are formed in some of the plurality of membranes.

[0012] For example, in the through hole of the frame, a seating surface extending from at least one of the plurality of membranes along the edge of the through hole toward the through hole may be formed, and the membrane electrode assembly and the gas diffusion layer may be coupled through the seating surface formed in the through hole.

[0013] For example, the gas diffusion layer can be bonded to both sides of the membrane electrode assembly, the gas diffusion layer bonded to one side of the membrane electrode assembly can be placed on the mounting surface together with the membrane electrode assembly, and the gas diffusion layer bonded to the other side can be formed to be smaller in size than the membrane electrode assembly and arranged in the through hole in a state of not being placed on the mounting surface.

[0014] For example, a plurality of slits may be formed in some of the plurality of films by cutting some of the plurality of films, and the plurality of slits may be formed in parallel along the edge of the manifold hole and spaced apart from each other.

[0015] For example, the frame may include first slits and second slits formed in different regions, the first slits may be formed in some of the plurality of films, and the second slits may be formed in other films except for the some of the plurality of films.

[0016] For example, the first slit and the second slit may be formed in different manifold holes.

[0017] For example, the first slit may be formed in some of the membranes disposed on the side in contact with the anode separator among the plurality of membranes, and the second slit may be formed in the other membranes disposed on the side in contact with the cathode separator among the plurality of membranes.

[0018] For example, a gasket may be installed on the side of each of the anode separator and the cathode separator that does not face the frame, and the first slit and the second slit may be formed by extending from the manifold hole of the frame to a point behind the corresponding point where the gasket of each of the anode separator and the cathode separator is installed.

[0019] For example, the frame may be formed by surface adherence of a first membrane contacting the anode separator and a second membrane contacting the cathode separator, the first slit may be formed in the first membrane, and the second slit may be formed in the second membrane.

[0020] For example, the first slit may be formed in the outermost membrane on the side of the plurality of membranes contacting the anode separator, and the second slit may be formed in the outermost membrane on the side of the plurality of membranes contacting the cathode separator.

[0021] For example, formations may be formed on the anode separator and the cathode separator at points corresponding to the first slit and the second slit, respectively, so that the formations and each slit together may form a flow path.

[0022] For example, the widthwise length of the forming portion formed on each of the anode separator and the cathode separator may be formed to be the same as or different from the widthwise lengths of the first slit and the second slit.

[0023] For example, the frame may be provided with a plurality of first slits and a plurality of second slits spaced apart in parallel with each other, and the anode separator and the cathode separator may have a plurality of forming parts at points corresponding to the plurality of first slits and the plurality of second slits.

[0024] For example, the width direction lengths of the plurality of forming portions may be formed to be the same as or different from each other.

[0025] For example, the forming portion is formed to protrude toward a side of each of the anode separator and the cathode separator that does not face the frame.

[0026] For example, a reaction surface is formed in the central portion of each of the anode separator and the cathode separator corresponding to one side of the frame, each edge portion may be formed with a manifold hole through which fluid flows, and the forming portion may be formed to extend from the manifold hole of each of the anode separator and the cathode separator toward the reaction surface.

[0027] For example, a side of each of the anode separator and the cathode separator that does not face the frame may be mounted with a gasket, and the formed portion may be formed by extending from the manifold hole of each of the anode separator and the cathode separator only to a point where the gasket is mounted.

[0028] According to the above, in the unit cell for a fuel cell of the presently disclosed embodiment, a seating surface is formed in the through hole of the frame, and the membrane electrode assembly and the gas diffusion layer are seated on the seating surface, thereby minimizing the occurrence of a step between the frame and the gas diffusion layer.

[0029] Furthermore, by configuring the frame with a plurality of films and forming a fine structure of the frame by film cutting, the frame can be molded similarly to one molded by an injection method, reducing the occurrence of deformation and easily forming a desired structure.

[0030] Furthermore, slits are formed by cutting some of the plurality of films, and inlets / outlets and paths for fluid to flow through the slits and the formations formed on the separator, thereby improving transferability of the fluid into the separator.

[0031] Furthermore, by cutting the film to form slits, the cross-sectional area of ​​the inlet / outlet through which the fluid flows can be freely adjusted.

[0032] The effects of the embodiments of the present disclosure are not limited to the above-described effects, and other effects not described herein will become apparent to those skilled in the art from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is an exploded perspective view showing a unit cell for a fuel cell according to an embodiment of the present disclosure.

[0034] Figure 2 is a diagram showing one side of a frame according to an embodiment of the present disclosure.

[0035] Figure 3 is along Figure 2 A cross-sectional view taken along line II.

[0036] Figure 4 1 is a diagram showing one side of a frame disposed on an anode separator according to an embodiment of the present disclosure.

[0037] Figure 5 FIG. 1 is a diagram showing that a frame according to an embodiment of the present disclosure is disposed on the other side of a cathode separator.

[0038] Figure 6 is a diagram showing a cathode separator of a unit cell for a fuel cell according to an embodiment of the present disclosure.

[0039] Figure 7 is along Figure 6 A cross-sectional view taken along line II-II.

[0040] Figure 8 is along Figure 6 Cross-sectional view taken along line III-III.

[0041] Fig. 9 is a diagram showing an anode separator of a unit cell for a fuel cell according to an embodiment of the present disclosure.

[0042] Fig.10 is along Fig. 9 A cross-sectional view taken along line IV-IV.

[0043] Fig.11 is along Fig. 9A cross-sectional view taken along line VV.

[0044] Figures 12 to 15 is a perspective view showing a cathode separator of a unit cell for a fuel cell according to other embodiments of the present disclosure. DETAILED DESCRIPTION

[0045] When describing the embodiments of the present disclosure, if it is determined that a detailed description of the known technology will make the embodiments of the present disclosure unclear, the detailed description of the known technology will be omitted. In addition, the drawings are used to help easily understand the embodiments of the present disclosure, and it should be understood that the embodiments proposed herein are not limited to the drawings. Therefore, it should be understood that the embodiments of the present disclosure include all variations, equivalents, and alternatives within the conceptual and technical scope of the embodiments of the present disclosure.

[0046] Although terms including ordinal numbers such as first, second, etc. may be used to describe various elements, the structural elements are not limited by these terms. These terms are used only for the purpose of distinguishing one element from other elements.

[0047] It should be understood that when an element is referred to as being "connected" or "coupled" to other elements, it can be directly connected or coupled to the other elements, or there may be intervening elements. On the contrary, when an element is referred to as being "directly connected" or "directly coupled" to other elements, there are no intervening elements.

[0048] Singular forms are intended to include plural forms as well, unless the context clearly indicates otherwise.

[0049] It should also be understood that the terms “comprises,” “includes,” and / or “comprising” when used herein refer to the presence of stated features, integers, steps, operations, elements, parts, and / or combinations thereof, but do not preclude the pre-existence or addition of one or more other features, integers, steps, operations, elements, parts, and / or combinations thereof.

[0050] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, regardless of the figure numbers, the same or similar components will be assigned the same reference numerals, and repeated descriptions thereof will be omitted.

[0051] First, refer to Figure 1 A unit cell for a fuel cell according to an embodiment of the present disclosure is described.

[0052] Figure 1 is an exploded perspective view showing a unit cell for a fuel cell according to an embodiment of the present disclosure.

[0053] Reference Figure 1, a unit cell 10 for a fuel cell according to an embodiment of the present disclosure may include an anode separator 110, a cathode separator 120, a frame 200, a membrane electrode assembly 300, and a gas diffusion layer 400. Each component is described as follows.

[0054] The unit cell 10 for a fuel cell may be a component forming a fuel cell stack. For example, the unit cell 10 may include an anode (positive electrode), a cathode (negative electrode), and an electrolyte membrane between the anode and the cathode. Specifically, the electrolyte membrane is located between the anode and the cathode, and is capable of conducting hydrogen ions while electrically separating the anode and the cathode. The anode and the cathode may be coated with a catalyst that ionizes hydrogen and oxygen, and the anode and the cathode may be joined to the electrolyte membrane and exist as a unit. This is referred to as a membrane electrode assembly (MEA) 300.

[0055] Gas diffusion layers (GDL) 400 may be disposed on both sides of the membrane electrode assembly 300 , and the gas diffusion layers 400 may include an anode gas diffusion layer disposed on the anode side of the membrane electrode assembly 300 and a cathode gas diffusion layer disposed on the cathode side of the membrane electrode assembly 300 .

[0056] Due to the provision of the gas diffusion layer 400, the transfer and distribution of hydrogen and oxygen to the membrane electrode assembly 300 can be smoothly performed. The anode gas diffusion layer can diffuse hydrogen, and the cathode gas diffusion layer can diffuse air.

[0057] The separator 100 may be combined with the structure formed by combining the membrane electrode assembly 300 and the gas diffusion layer 400 to form a unit cell 10. The separator 100 may electrically connect the unit cells 10, and a flow path through which hydrogen and oxygen move may be formed in the separator 100. For example, the anode separator 110 may be disposed on the anode side of the membrane electrode assembly 300, and the cathode separator 120 may be disposed on the cathode side of the membrane electrode assembly 300.

[0058] A frame 200 may be provided between the anode separator 110 and the cathode separator 120. Conventionally, the frame 200 is formed by injection molding and is made of engineering plastic (EP). However, it is impossible to form a fine structure in the frame 200 by injection molding. In an embodiment of the present disclosure, the frame 200 may be formed by stacking a plurality of films, rather than by injection molding. That is, the frame 200 according to an embodiment of the present disclosure may be formed by stacking a plurality of films.

[0059] Meanwhile, the frame 200 may be formed with a through hole TH at the center thereof, and the membrane electrode assembly 300 and the gas diffusion layer 400 may be coupled to the frame 200 through the through hole TH. To this end, a placement surface SA may be formed in the through hole TH, where the membrane electrode assembly 300 and the gas diffusion layer 400 are coupled. For example, the placement surface SA may be formed by extending from at least one of the plurality of membranes along the edge of the through hole TH toward the through hole TH. This will be referred to as Figures 2 to 3 Provide explanation.

[0060] Figure 2 is a diagram showing one side of a frame according to an embodiment of the present disclosure. Figure 3 is along Figure 2 A cross-sectional view taken along line II.

[0061] First, if Figure 2 As shown, the membrane electrode assembly 300 and the gas diffusion layer 400 may be combined in the through hole TH formed in the center of the frame 200. When the gas diffusion layer 400 is adhered to both sides of the membrane electrode assembly, the gas diffusion layer 400 may be exposed in the regions corresponding to the through hole TH on both sides of the frame 200. Figure 2 , it is assumed that the anode gas diffusion layer is exposed at one side of the frame 200.

[0062] like Figure 3 As shown, the seating surface SA extending toward the through hole TH may be formed on one of the plurality of films forming the frame 200. Figure 3 In the embodiment, for convenience of explanation, it is assumed that the frame 200 is formed of two films. However, this is an example and the number of films is not necessarily limited thereto.

[0063] In addition, the membrane electrode assembly 300 and the gas diffusion layer 400 may be coupled to the formed placement surface SA. For example, the gas diffusion layer 400 is coupled to both sides of the membrane electrode assembly 300, and the gas diffusion layer 400 coupled to one side of the membrane electrode assembly 300 may be mounted on the placement surface SA together with the membrane electrode assembly 300. The gas diffusion layer 400 coupled to the other side of the membrane electrode assembly 300 may be formed in a smaller size than the membrane electrode assembly 300, and may be disposed in the through hole TH without being mounted on the placement surface SA.

[0064] Since the seating surface SA is formed in the through hole TH of the frame 200 and the membrane electrode assembly 300 and the gas diffusion layer 400 are seated on the seating surface SA, the gas diffusion layer 400 may form a height level similar to the frame 200 and may be coupled to the frame 200 .

[0065] In other words, by minimizing the level difference between the frame 200 and the gas diffusion layer 400 , the thickness of the unit cell 10 may be prevented from increasing.

[0066] At the same time, refer again Figure 2 The frame 200 may be formed with manifold holes at the edge of the frame 200 for fluid to flow through, and the manifold holes may be divided into a plurality of holes according to the type of fluid. For example, the frame 200 may be formed with a first manifold hole MH1 for hydrogen to flow through, a second manifold hole MH2 for air to flow through, and a third manifold hole MH3 for coolant to flow through.

[0067] In addition, the frame 200 according to an embodiment of the present disclosure is formed of a plurality of films, and a fine structure formed in the frame 200 can be formed by cutting each film. For example, some of the plurality of films forming the frame 200 may have slits extending from the manifold hole to the through hole TH and cut into a fluid flow path. In addition, a plurality of slits may be formed in some of the plurality of films by cutting the films, and the plurality of slits may be formed in parallel along the edge of the manifold hole and spaced apart from each other. This will be achieved by Figure 4 and 5 To explain.

[0068] Figure 4 1 is a diagram showing one side of a frame disposed on an anode separator according to an embodiment of the present disclosure. Figure 5 FIG. 1 is a diagram showing that a frame according to an embodiment of the present disclosure is disposed on the other side of a cathode separator.

[0069] First, it is assumed that the frame 200 to be described below is formed of a plurality of films (eg, two films). This is an assumption made only for the convenience of explanation, and it is obvious that the configuration of the frame 200 is not necessarily limited thereto.

[0070] The frame 200 may be formed of a first film 210 contacting the anode separator 110 and a second film 220 contacting the cathode separator 120 , and the first film 210 and the second film 220 may be formed by surface attachment to each other.

[0071] Figure 4 FIG. 2 is a diagram of the first membrane 210 in contact with the anode separator 110. Figure 4 , a plurality of manifold holes MH1, MH2, MH3 may be formed in the first film 210, and a first slit 211 cut extending from one of the manifold holes (e.g., MH1) toward the through hole TH may be formed in the first film 210. When the number of films forming the frame 200 exceeds two, the first slit 211 may be formed in some of the films disposed on the side in contact with the anode separator 110 among the plurality of films. In particular, the first slit 211 may be formed in the outermost film on the side in contact with the anode separator 110 among the plurality of films.

[0072] In addition, a plurality of first slits 211 may be cut and formed in the first film 210 , and the plurality of first slits 211 may be formed in parallel along an edge of one manifold hole (eg, MH1 ) and spaced apart from each other.

[0073] also, Figure 5 2 is a diagram of the second film 220 in contact with the cathode separator 120. Figure 5 , a plurality of manifold holes MH1, MH2, MH3 may be formed in the second film 220, and a second slit 221 cut extending from one of the manifold holes (e.g., MH1) toward the through hole TH may be formed in the second film 220. When the number of films forming the frame 200 exceeds two, the second slit 221 may be formed in some of the films disposed on the side in contact with the cathode separator 120 among the plurality of films. In particular, the second slit 221 may be formed in the outermost film on the side in contact with the cathode separator 120 among the plurality of films.

[0074] Furthermore, a plurality of second slits 221 may be cut and formed in the second film 220 , and the plurality of second slits 221 may be formed in parallel along an edge of one manifold hole (eg, MH2 ) and spaced apart from each other.

[0075] The first film 210 and the second film 220 are surface-attached to each other to form the frame 200. Figure 4 and Figure 5 It can be seen from the figure that the first slit 211 and the second slit 221 are formed in different regions.

[0076] In other words, the frame 200 includes the first slit 211 and the second slit 221 formed in different regions, and when the frame 200 is formed of a plurality of films, some of the plurality of films may include the first slit 211, and other films except for the some of the plurality of films may include the second slit 221. In addition, in connection with this, the first slit 211 and the second slit 221 may be formed on different manifold holes.

[0077] In the following, reference will be made to Figures 6 to 11 The description is made of the fluid flow path formed by the above-mentioned slits 211 and 221 and the fluid flow. However, for ease of understanding, the cathode separator 120 of the unit cell 10 will be described first, and then the anode separator 110 will be described.

[0078] First, refer to Figures 6 to 8 The cathode separator 120 of the unit cell 10 is described.

[0079] Figure 6 is a diagram showing a cathode separator of a unit cell for a fuel cell according to an embodiment of the present disclosure. Figure 7 is along Figure 6 A cross-sectional view taken along line II-II. Figure 8 is along Figure 6 Cross-sectional view taken along line III-III.

[0080] Reference Figure 6 , the cathode separator 120 may be coupled to one side of the frame 200, for example, to the second film 220. Therefore, the cathode separator 120 may be formed with a forming portion 121 at a point corresponding to the second slit 221 formed in the second film 220. If the frame 200 is provided with a plurality of second slits 221 spaced apart in parallel with each other, the cathode separator 120 may also be formed with a plurality of forming portions 121 at points corresponding to the plurality of second slits 221.

[0081] In addition, the forming part 121 may be formed to protrude toward a side of the cathode separator 120 that does not face the frame 200. Due to the shape of the forming part 121 formed on the cathode separator 120, the forming part 121 and the second slit 221 may form a fluid flow path.

[0082] However, the area where the forming part 121 is formed on the cathode separator 120 and the area where the second slit 221 is formed on the frame 200 may be limited. For example, the gasket 500 may be installed on one side of the cathode separator 120 that does not face the frame 200, that is, on the outer surface of the cathode separator 120. When the gasket 500 is installed on the cathode separator 120, the forming part 121 formed on the cathode separator 120 may be formed so as not to interfere with the area where the gasket 500 is installed.

[0083] For example, a reaction surface (not shown) may be formed at the center of the side surface of the cathode separator 120 corresponding to the frame 200, and manifold holes MH1, MH2, and MH3 through which a fluid flows may be formed on the edge of the cathode separator 120. Since the forming portion 121 must be formed to correspond to the second slit 221 formed in the frame 200, it may be formed to extend from the manifold hole MH2 (e.g., MH2) that is the same as the manifold hole MH2 formed with the second slit 221 toward the reaction surface. However, when the gasket 500 is mounted on the cathode separator 120, the forming portion 121 may be formed to extend from the manifold hole MH2 only to the point where the gasket 500 is mounted.

[0084] On the other hand, the frame 200 is coupled to the inner surface of the cathode separator 120, and may be formed with the second slit 221 formed in the frame 200 regardless of whether the gasket 500 is installed. That is, the second slit 221 may extend from the manifold hole MH2 of the frame 200 to a point located behind a point corresponding to a point where the gasket 500 of the cathode separator 120 is installed.

[0085] Will refer to Figure 7 and Figure 8 The flow of the fluid due to the difference in shape between the forming portion 121 and the second slit 221 is described.

[0086] Reference Figure 7, it can be seen that the forming portion 121 is formed to protrude only to the front of the point where the gasket 500 is installed. Due to the protruding forming portion 121, the fluid flowing along the manifold hole MH2 can easily flow into the inside of the forming portion 121, and the inflowing fluid flows from front to back along the forming portion 121. In this case, when viewed at the point where the gasket 500 is installed, it can be seen that a space as large as a membrane is formed between the anode separator 110 and the cathode separator 120. This can be a space formed by the second slit 221 extending to a point behind the installation point of the gasket 500 of the second membrane 220 located on the side facing the cathode separator 120 among the membranes 210, 220 of the forming frame 200. Due to this space, the fluid flowing in through the forming portion 121 can flow smoothly from the front to the back, and the transferability of the fluid is improved.

[0087] At the same time, refer to Figure 8 , the forming portion 121 is formed to protrude only in front of the mounting point of the gasket 500, and therefore, since the frame 200 does not form a space at the mounting point of the gasket 500, the inflowing fluid cannot be sent to the rear. That is, the fluid is basically introduced through the forming portion 121, but a selective fluid flow is formed, which transmits or does not transmit the introduced fluid to the rear according to the formation position of the second slit 221 of the frame 200.

[0088] Next, we will refer to Figures 9 to 11 The anode separator 110 of the unit cell 10 is described.

[0089] Fig. 9 is a diagram showing an anode separator of a unit cell for a fuel cell according to an embodiment of the present disclosure. Fig.10 is along Fig. 9 A cross-sectional view taken along line IV-IV. Fig.11 is along Fig. 9 A cross-sectional view taken along line VV in FIG.

[0090] Reference Fig. 9 , the anode separator 110 may be coupled to the other side of the frame 200, for example, to the first membrane 210. Therefore, the anode separator 110 may be formed with a forming portion 111 at a point corresponding to the first slit 211 formed in the first membrane 210. If the frame 200 is provided with a plurality of first slits 211 spaced apart in parallel with each other, the anode separator 110 may also be formed with a plurality of forming portions 111 at points corresponding to the plurality of first slits 211.

[0091] In addition, the forming part 111 may be formed to protrude toward a side of the anode separator 110 that does not face the frame 200. Due to the shape of the forming part 111 formed on the anode separator 110, the forming part 111 and the first slit 211 may form a fluid flow path.

[0092] However, as mentioned above Figure 6 As described above, the region where the forming portion 111 is formed on the anode separator 110 and the region where the first slit 211 is formed on the frame 200 may be limited. For example, the gasket 500 may be installed on one side of the anode separator 110 that does not face the frame 200, that is, on the outer surface of the anode separator 110. When the gasket 500 is installed on the anode separator 110, the forming portion 111 formed on the anode separator 110 may be formed so as not to interfere with the region where the gasket 500 is installed.

[0093] For example, a reaction surface (not shown) may be formed at the center of the side surface of the anode separator 110 corresponding to the frame 200, and manifold holes MH1, MH2, and MH3 through which fluid flows may be formed on the edge of the anode separator 110. Since the forming portion 111 must be formed to correspond to the first slit 211 formed in the frame 200, it may be formed to extend from the manifold hole MH1 (e.g., MH1) that is the same as the manifold hole MH1 formed with the first slit 211 toward the reaction surface. However, when the gasket 500 is mounted on the anode separator 110, the forming portion 111 may be formed to extend from the manifold hole MH1 only to the point where the gasket 500 is mounted.

[0094] On the other hand, the frame 200 is coupled to the inner surface of the anode separator 110, and may be formed with the first slit 211 formed in the frame 200 regardless of whether the gasket 500 is installed. That is, the first slit 211 may extend from the manifold hole MH1 of the frame 200 to a point located behind a point corresponding to a point where the gasket 500 of the anode separator 110 is installed.

[0095] Will refer to Fig.10 and Fig.11 The flow of the fluid due to the difference in shape between the forming portion 111 and the first slit 211 is described.

[0096] Reference Fig.10 , it can be seen that the forming portion 111 is formed to protrude only to the front of the point where the gasket 500 is installed. Due to the protruding forming portion 111, the fluid flowing along the manifold hole MH1 can easily flow into the inside of the forming portion 111, and the inflowing fluid flows from front to back along the forming portion 111. In this case, when viewed at the point where the gasket 500 is installed, it can be seen that a space as large as a film is formed between the anode separator 110 and the cathode separator 120. This may be a space formed by the first slit 211 extending to a point behind the attachment point of the gasket 500 of the first membrane 210 located on the side facing the anode separator 110 among the membranes 210, 220 of the forming frame 200. Due to this space, the fluid flowing in through the forming portion 111 can flow smoothly from the front to the back, and the transferability of the fluid is improved.

[0097] At the same time, refer to Fig.11 In the part without the forming part 111, the frame 200 blocks the inflow of the fluid, and as a result, the fluid cannot be transported to the rear. That is, not only can the fluid be selectively introduced through the forming part 111, but also a selective fluid flow that transports or does not transport the fluid to the rear can be formed.

[0098] On the other hand, the forming portion 111 formed on the anode separator 110 and the forming portion 121 formed on the cathode separator 120 may be formed to have the same or different lengths in the width direction as the first slit 211 and the second slit 221, and the width direction lengths of the first slit 211 and the second slit 221 correspond to the forming portions 111 and 121, respectively. In addition, when the forming portion 111 formed on the anode separator 110 and the forming portion 121 formed on the cathode separator 120 are formed in plurality, each of the plurality of forming portions may be formed to have the same or different lengths in the width direction. This reference Figures 12 to 15 Provide explanation.

[0099] Figures 12 to 15 is a perspective view showing a cathode separator of a unit cell for a fuel cell according to other embodiments of the present disclosure.

[0100] Reference Fig.12 and Fig.13 , the widthwise length of the forming portion 121 formed on the cathode separator 120 may be formed to be the same as the widthwise length of the second slit 221 of the frame 200 corresponding to the forming portion 121. That is, the widthwise length of the forming portion 121 and the widthwise length of the second slit 221 may both be formed to be wide or narrow.

[0101] At the same time, refer to Fig.14 , the widthwise length of the forming portion 121 formed on the cathode separator 120 may be fixed, and the widthwise length of the second slit 221 of the frame 200 may be formed to gradually increase or decrease.

[0102] Thus, by freely adjusting the cross-sectional area through which the fluid is introduced or flows, the flow rate or amount of the fluid flowing into the cathode separator 120 can be adjusted.

[0103] On the other hand, refer to Fig.15 , the width direction length of the forming portion 121 formed on the cathode separator 120 and the width direction length of the second slit 221 of the frame 200 may be fixed, and the shape of the end of the second slit 221 extending to the rear may be changed. Thus, when the fluid flows in along the fluid flow path formed by the forming portion 121 and the second slit 221, the inflowing fluid can smoothly flow to the arrival point behind.

[0104] According to the above, in the unit cell for a fuel cell of the embodiment of the present disclosure, a seating surface is formed in the through hole of the frame, and the membrane electrode assembly and the gas diffusion layer are seated on the seating surface, thereby minimizing the generation of a height difference between the frame and the gas diffusion layer.

[0105] Furthermore, by constructing the frame with a plurality of films and forming a fine structure of the frame by film cutting, the frame can be molded similarly to one molded by injection molding, reducing the occurrence of deformation, and easily forming a desired structure.

[0106] Furthermore, slits are formed by cutting some of the plurality of films, and inlets / outlets and paths through which fluid flows through the slits and the formations formed on the separator, thereby improving transferability of the fluid into the separator.

[0107] Furthermore, by cutting the film to form slits, the cross-sectional area of ​​the inlet / outlet through which the fluid flows can be freely adjusted.

[0108] Although the exemplary embodiments of the present disclosure have been disclosed for illustrative purposes, those skilled in the art will appreciate that various improvements and modifications may be made without departing from the scope and spirit of the embodiments of the present disclosure as disclosed in the appended claims.

[0109] The above detailed description should not be interpreted as limiting in any aspect, but should be regarded as illustrative. The scope of the embodiments of the present disclosure should be determined by reasonable interpretation of the attached claims, and all changes within the equivalent scope of the embodiments of the present disclosure are included in the scope of the embodiments of the present disclosure.

Claims

1. A unit cell for a fuel cell, the unit cell comprising: Anode separator; cathode separator; A frame is provided between the anode separator and the cathode separator, the frame comprising: Multiple membranes stacked together; a through hole provided in the central portion of the frame; a manifold hole disposed at an edge portion of the frame, wherein the manifold hole is configured to allow fluid to flow therethrough; and slits disposed in a plurality of first membranes among the plurality of membranes, the slits extending from the manifold hole toward the through hole and cut to form a fluid flow path; and a membrane electrode assembly and a pair of gas diffusion layers bonded to a first side and a second side of the membrane electrode assembly, respectively, The membrane electrode assembly and the pair of gas diffusion layers are disposed in the through holes of the frame.

2. The unit cell according to claim 1, further comprising a placement surface located in the through hole of the frame, the placement surface extending from one of the plurality of membranes along an edge of the through hole toward the through hole, wherein the membrane electrode assembly is disposed on the placement surface.

3. A unit cell according to claim 2, wherein a first gas diffusion layer of the pair of gas diffusion layers coupled to a first side of the membrane electrode assembly is placed on the placement surface together with the membrane electrode assembly, and a second gas diffusion layer of the pair of gas diffusion layers coupled to a second side of the membrane electrode assembly is smaller in size than the membrane electrode assembly and is arranged in the through hole in a state of not being placed on the placement surface.

4. The unit cell according to claim 1, wherein the slits include a plurality of slits disposed in a plurality of first films among the plurality of films, the slits are disposed in parallel and spaced apart from each other along an edge of the manifold hole, and the slits include cutouts in a plurality of first films among the plurality of films.

5. A unit cell for a fuel cell, the unit cell comprising: Anode separator; cathode separator; A frame is provided between the anode separator and the cathode separator, the frame comprising: Multiple membranes stacked together; a through hole provided in the central portion of the frame; a manifold hole disposed at an edge portion of the frame, wherein the manifold hole is configured to allow a fluid to flow therethrough; a first slit disposed in a first membrane among the plurality of membranes, extending from the manifold hole toward the through hole and cut to form a fluid flow path; and a second slit provided in a region different from the first slit and provided in a second film among the plurality of films different from a first film among the plurality of films; and a membrane electrode assembly and a pair of gas diffusion layers bonded to a first side and a second side of the membrane electrode assembly, respectively, The membrane electrode assembly and the pair of gas diffusion layers are disposed in the through holes of the frame. The unit cell according to claim 5 , wherein the first slit and the second slit extend from different manifold holes.

7. The unit cell according to claim 5, wherein a first membrane among the plurality of membranes is disposed on a first side of the frame in contact with an inner side of the anode separator, and a second membrane among the plurality of membranes is disposed on a second side of the frame in contact with an inner side of the cathode separator.

8. The unit cell according to claim 7 further comprises a pair of gaskets respectively disposed on the outer side of each of the anode separator and the cathode separator, wherein the first slit and the second slit extend from the manifold hole of the frame to a point located behind a corresponding point where each of the pair of gaskets is disposed. 9 . The unit cell according to claim 7 , wherein the first film is bonded to the second film by surface attachment.

10. The unit cell according to claim 7, wherein the first membrane comprises a plurality of first membrane layers stacked together, and the second membrane comprises a plurality of second membrane layers stacked together, the first slit is cut in an outermost membrane layer on an outer side in contact with the anode separator among the plurality of first membrane layers, and the second slit is cut in an outermost membrane layer on an outer side in contact with the cathode separator among the plurality of second membrane layers.

11. The unit cell according to claim 7, further comprising a formation provided on the anode separator and the cathode separator at points corresponding to the first slit and the second slit, respectively, so that the formation forms the fluid flow path together with each of the first slit and the second slit. 12 . The unit battery according to claim 11 , wherein a widthwise length of the forming portion is equal to widthwise lengths of the first slit and the second slit. 13 . The unit battery according to claim 11 , wherein a widthwise length of the forming portion is different from widthwise lengths of the first slit and the second slit.

14. The unit cell according to claim 11, wherein the first slits are provided in plurality and spaced apart in parallel with each other, the second slits are provided in plurality and spaced apart in parallel with each other, the anode separator has a plurality of formed portions at points corresponding to the first slits, and the cathode separator has a plurality of formed portions at points corresponding to the second slits. 15 . The unit battery according to claim 14 , wherein width-direction lengths of the forming portions are equal to each other. The unit battery according to claim 14 , wherein width-direction lengths of the forming portions are different from each other. 17 . The unit cell according to claim 11 , wherein the forming portions protrude toward an outer side of the anode separator and an outer side of the cathode separator, respectively, which do not face the frame.

18. The unit cell according to claim 11, wherein a reaction surface is respectively provided in a central portion of each of the anode separator and the cathode separator facing the inner side of the frame, each edge portion is provided with the manifold hole, and the forming portion extends from the manifold hole of each of the anode separator and the cathode separator toward the reaction surface.

19. The unit cell according to claim 18, further comprising a pair of gaskets respectively disposed on the outer side of each of the anode separator and the cathode separator that does not face the frame, wherein the forming portion extends from the manifold hole of each of the anode separator and the cathode separator only to a point where the gasket is disposed.

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