FUEL CELL WITH AN INTEGRATED POROUS MATERIAL SEAL STRUCTURE

Abstract

Fuel cell with an integrated porous material seal structure (100), wherein the fuel cell comprises: an integrated porous material seal structure (100) with a thin frame (110) having a plurality of distributors (112) formed on opposite sides of the same, a porous material (120) formed in one piece adjacent to the distributors (112) of the thin frame (110), and a seal (130) formed in one piece on the thin frame (110);and a separator (200) with a section for receiving the porous material (120) in which the integrated porous material-seal structure (100) is stacked, wherein the porous material (120) is arranged between a distributor (112) of the separator (200) through which gas is supplied and a reaction flow field (202) of the separator (200) in which an electrochemical reaction takes place, wherein the reaction flow field (202) is free of porous material (120).

Description

BACKGROUND (a) Technical field The present invention relates to a fuel cell with an integrated porous material seal structure. More precisely, the present invention relates to a fuel cell with an integrated porous material seal structure stacked on a separator, wherein a porous material and a seal are formed in one piece. The resulting structure allows the flow of gas and water through the fuel cell. (b) Background of the invention The configuration of a unit cell of a typical fuel cell stack will be described with reference to Fig. 8. A membrane electrolyte assembly (MEA) is positioned in the center of the unit cell. The MEA contains a polymer electrolyte membrane 10 capable of transporting hydrogen ions (protons) and catalyst layers, such as a cathode 12 and an anode 14. The catalyst layers are applied to both sides of the electrolyte membrane 10 such that hydrogen and oxygen react with each other. As shown, a gas diffusion layer (GDL) 16 is stacked on the outside of both the cathode 12 and the anode 14. A separator 20, in which flow fields are formed to supply fuel and remove water produced by a reaction, is stacked between the gas diffusion layer 16 and the seal 18, and an end plate 30 for storing and securing the components described above is connected to the outermost side end. Consequently, an oxidation reaction of hydrogen takes place at the anode 14 of the fuel cell stack to generate hydrogen ions (protons) and electrons, and the generated hydrogen ions and electrons are transferred through the electrolyte membrane 10 and the separator 20 to the cathode 12. At the cathode 12, the hydrogen ions and electrons transferred from the anode 14 react with oxygen-containing air to produce water. At the same time, electrical energy is generated by the electron flow and supplied to a load requiring the energy via a current collector connected to the end plate 30. In the fuel cell described above, the water produced is not discharged uniformly onto a reaction surface of the separator 20, which is in contact with the anode 14 and the cathode 12, respectively. Consequently, a flooding event occurs, and at the same time, the flow fields of the separator 20 become clogged, which is very problematic. A proposed method for addressing these disadvantages is shown in Fig. 7, in which a fuel cell is provided with a separate porous material 40 arranged between a membrane electrode arrangement 50 and a separator 20 to allow the flow of gas and water. The porous material 40 is applied separately over a fuel flow region, i.e., a region between the anode and the separator and a region between the cathode and the separator. While the porous material 40 serves as a flow field, it also increases the number of layers forming the fuel cell and consequently increases the length and thickness of the fuel cell stack. Furthermore, since the porous material 40 is applied separately over a large area of ​​reaction zones, the heat transfer efficiency for transferring heat to the outside of the fuel cell during heat dissipation is reduced. This can cause overheating of the fuel cell stack and consequently reduce the fuel cell stack's performance. For the state of the art, reference can be made to DE 10 2011 085 069 A1 and US 2011 / 0 014 541 A1. The above information disclosed in this background section is intended only to improve the understanding of the background of the invention and may therefore contain information that does not constitute prior art that would already be known to someone with ordinary technical skills in this country. SUMMARY OF THE REVELATION The present invention provides a fuel cell with an integrated porous material-seal structure that enables the flow of gas and water. More precisely, the present invention provides a fuel cell in which an integrated porous material-seal structure, in which a porous material and a seal are formed in one piece, is stacked on a separator such that the porous material is located between a distributor through which gas is supplied and a reaction surface where an electrochemical reaction takes place. The integrated porous material-seal structure essentially serves as a diffuser for the gas supplied through the distributor. In one aspect, the present invention provides a fuel cell with an integrated porous material-seal structure, wherein the fuel cell comprises: an integrated porous material-seal structure comprising a thin frame with a plurality of distributors formed on both sides thereof, a porous material integrally formed at a position adjacent to the distributors of the thin frame, and a seal integrally formed on the thin frame; and a separator comprising a section for receiving the porous material in which the integrated porous material-seal structure is stacked, wherein the porous material is arranged between a distributor of the separator through which gas is supplied and a reaction flow field of the separator in which an electrochemical reaction takes place, wherein the reaction flow field is free of porous material. In an exemplary embodiment, the thin frame of the integrated porous material-seal structure has a structure in which a plurality of distributors are formed on both sides of it and frames for storing the porous material are formed in one piece on the inside of the distributors. In yet another exemplary embodiment, a sealing material is formed in one piece on the upper and lower surfaces of the porous material and on outer surfaces, with the exception of the area that is in contact with a distributor selected from the plurality of distributors. In yet another exemplary embodiment, the thin frame and the porous material are made of the same metal and are formed in one piece. In another exemplary embodiment, the frame contains a plurality of through-holes for injection molding the seal. In yet another preferred embodiment, the separator has a structure in which a section for receiving the porous material is formed between the distributors, which are formed on both sides of it, and a reaction flow field, which is formed by a central section of it. In yet another preferred embodiment, the reaction flow field in the section for receiving the porous material is designed as a straight flow field. Other aspects and exemplary embodiments of the invention are discussed below. BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other features of the present invention will now be described in detail with regard to certain exemplary embodiments thereof, which are illustrated in the accompanying drawings, which below serve only for illustration and consequently do not limit the present invention, and in which: Figs. 1A and 1B are a front view and a cross-sectional view, respectively, showing that a porous material is integrally formed on a thin frame to implement a fuel cell with an integrated porous material-seal structure according to an embodiment of the present invention; Figs. 2A to 2C are front views showing that a sealing material is formed on a porous material of an integrated porous material-seal structure according to an embodiment of the present invention; Fig.3 is a front view showing an integrated porous material-seal structure according to an embodiment of the present invention, wherein a porous material and a seal are integrally formed on a thin frame; Fig. 4 is a front view showing the structure of a separator for implementing a fuel cell with an integrated porous material-seal structure according to an embodiment of the present invention; Fig. 5 is a front view showing a structure in which an integrated porous material-seal structure and a separator are stacked according to an embodiment of the present invention; Fig. 6 is a cross-sectional view taken along line BB of Fig. 5, showing that several cells are stacked; Fig. 7 is a schematic representation showing the structure of a fuel cell in which a conventional porous material is used; and Fig.Figure 8 is a schematic representation showing the configuration of a unit cell of a typical fuel cell stack. The reference numerals shown in the drawings refer to the following elements, which are discussed further below: 100 Integrated porous material structure-seal 110 Thin frame 112 Distributor 114 Reaction area 116 Frame for holding the porous material 118 Distributor inner frame 122 Sealing material 132 Through-hole 120 Porous material 130 Seal 200 Separator 202 Reaction flow field 204 Porous material receiving section 206 Distributor It should be clear that the accompanying drawings are not necessarily to scale and represent a somewhat simplified depiction of various preferred features that illustrate the basic principles of the invention. The specific design features of the present invention disclosed herein, which include, for example, certain dimensions, orientations, positions, and shapes, will be partly determined by the specific intended application and operating environment. In the figures, the reference numbers throughout the various figures of the drawing refer to identical or equivalent parts of the present invention. DETAILED DESCRIPTION The following section will describe in detail various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. Although the invention will be described in connection with exemplary embodiments, it will be clear that the present description is not intended to limit the invention to these exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments but also various alternatives, modifications, equivalents, and other embodiments that may be included within the nature and scope of the invention as defined by the accompanying claims. It is clear that the term "vehicle" or "vehicle-" or any other similar term used herein includes motor vehicles in general, such as passenger cars, including all-terrain vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft, including a variety of boats and ships, aircraft and the like, and hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other vehicles using alternative fuels (e.g., fuels derived from raw materials other than petroleum). As defined herein, a hybrid vehicle is a vehicle that has two or more power sources, such as both gasoline-powered and electric-powered vehicles. The terminology used herein serves only to describe certain embodiments and is not intended to limit the invention. As used herein, the singular forms "a" and "the" are intended to include the plural forms unless the context otherwise makes clear. It will also be clear that the expressions "includes" and / or "include," when used in this description, specify the presence of the aforementioned 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 expression "and / or" includes any or all combinations of one or more of the associated, listed elements. Unless specifically stated or clear from the context, the term "approx." as used herein is to be understood as within a range of normal engineering tolerance, for example, within 2 standard deviations of the mean. "Approx." may be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear from the context, all numerical values ​​given herein are modified by the term "approx." The present invention provides an integrated porous material-seal structure in which a porous material and a seal are formed in one piece and stacked between a separator and a membrane electrode arrangement. With reference to Figures 1A and 1B, the integrated porous material structure 100-seal comprises a thin frame 110 in which a plurality of distributors 112 are formed, and a porous material 120 that is integrally formed in or at a position adjacent to the distributors 112 of the thin frame 110. As can be seen from Figure 3, a seal 130 is also integrally formed on the thin frame 110 in sections excluding the porous material 120. As shown, the thin frame 110 of the integrated structure 100, made of porous material, can be shaped as a rectangular frame and contains a variety of distributors 112, such as hydrogen, coolant, and air distributors. The thin frame 110 is formed on both sides of the structure and can be provided with a reaction surface area 114 with an open structure located in the center of the same, so that a reaction flow field 202 of a separator 200 is exposed (see Fig. 4-5). Frames 116 for storing the porous material can also be formed in one piece on the inside of the distributors 112 of the thin frame 110, which are arranged to extend upwards and downwards. The thin frame 110 has a smaller thickness than the porous material 120 and generally a thickness that provides a stiffness sufficient to prevent deformation during injection molding with the seal 130 or during handling. The porous material 120 preferably consists of the same metal as the thin frame 110 and is formed in one piece adjacent to the inside of the distributors 112 of the thin frame 110 during the formation of the thin frame 110. That is, the porous material 120 is formed in one piece between the distributors 112 of the thin frame 110 and the reaction surface area 114. This configuration is such that the reaction flow field 202 of the separator 200 is exposed when the separator 200 is subsequently stacked. In particular, the porous material 120 is formed in one piece to surround a distributor inner frame 118 and the frames 116 for storing the porous material of the thin frame 110 in such a way that the inner frame 118 of the distributor and the frames 116 for storing the porous material are connected by the porous material 120. At the same time, the porous material 120 is filled or inserted between the distributor inner frames 118 and the frames 116 for storing the porous material. As shown in Figures 2A to 2C, a sealing material 122 of a predetermined thickness is preferably formed integrally on the upper and lower surfaces of the porous material 120. The sealing material 122 can also be provided, as shown, on the outer surfaces of the porous material 120, with the exception of those sections that are in contact with a distributor of the plurality of distributors 112. As further shown in Figures 2A to 2C, the sealing material 122 can be absent from the side of the porous material 120 along the reaction surface region 114. As shown in Fig. 2A, the sealing material 122 is, for example, on the top and bottom surfaces of the porous material 120 and on the left outer surface, with the exception of the outer surface that is in contact with a hydrogen distributor through which hydrogen flows, designed such that only hydrogen can be supplied to the porous material 120. As shown, the right outer surface of the porous material 120 along the reaction surface area 114 is also not provided with the sealing material 122. Similarly, the sealing material 122 can be provided so that, by its absence along the air distributor (Fig. 2B) or coolant distributor (Fig. 2C), only air (Fig. 2B) or coolant (Fig. 2C), etc., is supplied to the porous material 120. According to various embodiments, the porous material 120, when formed in one piece with the thin frame 110, can have a porous structure, while the sealing material 122 can have a dense metal plate structure without pores. The porous material 120 and the sealing material 122 can be formed in one piece. After the thin frame 110 and the porous material 120 have been formed in one piece in the above manner, the seal 130 can be injection molded in one piece with the thin frame 110. According to various embodiments, the seal 130 is injection molded in such a way as to surround the thin frame 110 in sections except for the porous material 120 (see Fig. 3), and a plurality of through-holes 132 (see Fig. 1A) can be formed at regular intervals in the thin frame 110 to prevent deformation of the thin frame 110, to allow the flow of material for the seal 130 and to prevent the formation of burrs during the injection molding of the seal 130. Naturally, the number and size of the through-holes 132 can be adjusted to any suitable number and size depending on the flow characteristics of the material for the seal 130 and process conditions. When the seal 130 is injection molded with the thin frame 110, the seal 130 consequently surrounds the front and back sides of the thin frame 110 with a predetermined thickness and the seal 130 is integrally connected to it through the through-holes 132. The integrated porous material seal structure 100 of the present invention is configured such that the porous material 120, which preferably consists of the same metal as the thin frame 110, is formed integrally with the thin frame 110. Furthermore, the seal 130 is injection-molded integrally onto the thin frame 110 without being integrally formed onto the porous metal material 120. The integrated structure 100 made of porous material seal, configured in the manner above, can be stacked between the membrane electrode arrangement containing the cathode and the anode and the separator 200, thus forming a single unit cell. For this purpose, the separator 200 can be configured with a section 204 for receiving the porous material such that the integrated porous material-seal structure 100 can be easily stacked on the separator 200. In particular, the separator 200 can be provided with a structure, as shown in Fig. 4, in which a plurality of distributors 206 are formed on both sides of it, so that the plurality of distributors 206 can be aligned with and connected to the distributors 112 of the integrated porous material-seal structure 100. The separator 200 can further include the reaction flow field 202, in which channels and webs are repeated and which is arranged in the center of it, and the section 204 for receiving the porous material, which is formed between the distributors 206 and the reaction flow field 202. Here, the reaction flow field 202 of the separator 200, due to the porous material 120 incorporated in section 204 to hold the porous material, does not require a distribution flow field in the form of an inclined line or streamline. In fact, the distribution flow field can simply be designed as a straight flow field, which reduces the occurrence of defects due to the simplification of the separator's molded structure, reduces manufacturing costs and improves productivity due to the simplification of the mold structure, and reduces the occurrence of post-mold deformation due to the absence of rapid deformation of the separator. As shown in Fig. 5 and Fig. 6, one side of the integrated structure 100 made of porous material-seal is stacked on the separator 200 in such a way that the porous material 120 on the section 204 is tightly or densely accommodated to receive the porous material of the separator 200 and the seal 130 is in close contact with the outer four edges of the separator 200 and the edges of the distributors 206, and consequently obtains a gas impermeability. The other side of the integrated structure 100 made of porous material seal is further stacked on the cathode or anode side of the membrane electrode arrangement 50. Consequently, the porous material 120, as shown in Fig. 5, is located between the distributor 206 of the separator 200, through which gas is supplied, and the reaction flow field 202, in which an electrochemical reaction takes place. The gas (air or hydrogen) supplied through the distributor can easily spread towards the reaction flow field 202. According to various embodiments, either gas or water spreads through the porous material 120 and the other element of the same (water or gas) is blocked by the sealing material 122, which is formed on the top and bottom surfaces of the porous material 120 and the outer surfaces. As described above, the present invention provides the following effects. The integrated porous material-seal structure 100, in which the porous material and the seal 130 are integrally formed on the thin frame 110, is stacked on the separator 200 such that the porous material is located between the distributor 112, through which gas is supplied, and the reaction flow field 202, in which an electrochemical reaction takes place, to serve as a diffuser for the gas supplied through the distributor. Consequently, it is possible to allow the flow of gas and water through the porous material and prevent flooding in the reaction area, thereby improving the performance of the fuel cell. Since the porous material is formed in one piece with the seal 130, it is also possible to reduce the number of unit cells of the fuel cell stack, to shorten the overall length of the fuel cell stack and to reduce the overall volume of the fuel cell stack. Since the porous material is locally provided between the distributor 112, through which gas is supplied, and the reaction surface in which an electrochemical reaction takes place, it is possible to improve the heat transfer efficiency for transferring heat to the outside or fuel cell during heat dissipation and consequently to prevent the fuel cell stack from deteriorating due to overheating. The invention has been described in detail with regard to exemplary embodiments thereof. However, it will be apparent to someone with technical expertise that modifications can be made to these embodiments without departing from the principles and essence of the invention, the scope of which is defined in the accompanying claims and equivalents thereof.

Claims

Fuel cell with an integrated porous material seal structure (100), wherein the fuel cell comprises: an integrated porous material seal structure (100) with a thin frame (110) having a plurality of distributors (112) formed on opposite sides of the same, a porous material (120) formed in one piece adjacent to the distributors (112) of the thin frame (110), and a seal (130) formed in one piece on the thin frame (110);and a separator (200) with a section for receiving the porous material (120) in which the integrated porous material-seal structure (100) is stacked, wherein the porous material (120) is arranged between a distributor (112) of the separator (200) through which gas is supplied and a reaction flow field (202) of the separator (200) in which an electrochemical reaction takes place, wherein the reaction flow field (202) is free of porous material (120). Fuel cell according to claim 1, wherein the thin frame (110) further comprises frames for storing the porous material (120) which are formed in one piece adjacent to the inside of the distributors (112). Fuel cell according to claim 1 or 2, wherein the porous material (120) of the integrated porous material seal structure (100) is formed in one piece adjacent to the inside of the distributors (112) of the thin frame (110). Fuel cell according to claim 1 or 2, wherein the porous material (120) of the integrated porous material seal structure (100) is formed in one piece to surround a distributor inner frame (118) and the frames for storing the porous material (116) of the thin frame (110). Fuel cell according to claim 1, wherein a sealing material (122) is formed in one piece on the upper and lower surfaces of the porous material (120) and on an outer surface adjacent to the plurality of distributors (112), wherein the sealing material (122) is formed on the outer surface adjacent to the plurality of distributors (112) except for an area which is in contact with one of the plurality of distributors (112). Fuel cell according to claim 5, wherein the plurality of distributors (112) includes a hydrogen distributor, an air distributor and a coolant distributor and the sealing material (122) is formed on the outer surface of the porous material (120) adjacent to the plurality of distributors (112) except along the hydrogen distributor. Fuel cell according to claim 5, wherein the plurality of distributors (112) includes a hydrogen distributor, an air distributor and a coolant distributor and the sealing material is formed on the outer surface of the porous material (120) adjacent to the plurality of distributors (112) except along the air distributor. Fuel cell according to claim 5, wherein the plurality of distributors (112) includes a hydrogen distributor, an air distributor and a coolant distributor and the sealing material (122) is formed on the outer surface of the porous material (120) adjacent to the plurality of distributors (112) except along the coolant distributor. Fuel cell according to claim 1, wherein the thin frame (110) and the porous material (120) are made of the same metal and are formed in one piece. Fuel cell according to claim 1, wherein the thin frame (112) has a plurality of through-holes for injection molding the seal (130). Fuel cell according to claim 1 or 10, wherein the seal (130) is injection molded to surround the front and rear sides of the thin frame (110) and has a predetermined thickness, and the seal (130) is connected to the same through the through-holes (132). Fuel cell according to claim 1, wherein the separator (200) has a plurality of distributors formed on opposite sides thereof, a section for receiving the porous material (120) formed between the distributors (112), and the reaction flow field (202) formed in the middle thereof. Fuel cell according to claim 12, wherein the reaction flow field (202) in the section for receiving the porous material (120) is designed as a straight flow field.

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