fuel cell
The fuel cell separator's innovative seal structure with linear boundaries and recessed connecting portions addresses the challenge of miniaturization and rigidity, ensuring efficient sealing and load distribution.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2024-11-26
- Publication Date
- 2026-06-05
AI Technical Summary
Existing fuel cell separators with meandering side portions face challenges in miniaturization due to increased dimensional width, which affects their rigidity and sealing efficiency.
A fuel cell design featuring a seal structure with linearly formed boundaries and recessed connecting portions that distribute compressive loads, allowing for a reduced width and enhanced rigidity.
The design achieves a smaller dimensional width and improved rigidity of the seal structure, enhancing its ability to withstand compressive loads while maintaining effective sealing.
Smart Images
Figure 2026092262000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to fuel cell.
Background Art
[0002] Various techniques related to separators used in fuel cells have been proposed. For example, Patent Document 1 discloses a separator provided with a seal structure portion (also referred to as a "bead") for sealing reaction gas and refrigerant along the outer periphery. In a plan view, this seal structure portion includes a pair of meandering side portions and a top portion that extends linearly and is sandwiched between the pair of side portions. The meandering side portions increase the rigidity against compressive loads, while the linearly extending top portion shortens the seal length of the seal structure portion.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, since the side portions are meandering, the dimensional width of the seal structure portion increases. As a result, it is difficult to miniaturize the seal structure portion. There is a need for a separator having a seal structure portion that can be configured with a small dimensional width while improving rigidity.
Means for Solving the Problems
[0005] The present disclosure can be realized in the following forms.
[0006] According to one embodiment of the present disclosure, a fuel cell is provided comprising a membrane electrode gas diffusion layer assembly and a pair of separators provided so as to sandwich the membrane electrode gas diffusion layer assembly. Each separator has a structure in which a pair of plates are joined facing each other, and each plate has a plate body portion and a seal structure portion extending along the outer circumference of the plate body portion and protruding from the plate body portion in the thickness direction of the plate body portion, the seal structure portion has a top portion spaced apart from the plate body portion in the thickness direction and provided parallel to the plate body portion, and a pair of connecting portions connecting the plate body portion and the top portion and provided so as to sandwich the top portion, the boundary with the plate body portion being formed linearly when viewed in the thickness direction, and at least one of the pair of connecting portions has a recess. In this type of fuel cell, the boundary between the connection part and the plate body is formed in a straight line when viewed in the thickness direction, so the width of the sealing structure can be reduced compared to a configuration in which the boundary between the connection part and the plate body is meandering. Furthermore, since at least one of the pair of connecting parts has a recess, even if a compressive load is applied to the seal structure, the load can be distributed by the recess in the connecting part, and the rigidity of the seal structure can be improved compared to a configuration in which there is no recess in the connecting part. [Brief explanation of the drawing]
[0007] [Figure 1] This is a perspective view of a fuel cell in which a fuel cell cell according to one embodiment of the present disclosure is used. [Figure 2] This is a plan view of the separator. [Figure 3] This is a plan view of the seal structure in another embodiment. [Modes for carrying out the invention]
[0008] A. Embodiments: <Configuration of Fuel Cell 100> Figure 1 is a perspective view of a fuel cell 100 in which a fuel cell cell 10 in one embodiment of the present disclosure is used. Figure 1 shows mutually orthogonal X, Y, and Z axes. The fuel cell 100 is used, for example, as a power source for an electric vehicle. The fuel cell 100 comprises a cell stack 110 and a pair of terminal plates 120, 130.
[0009] The cell stack 110 is composed of a plurality of fuel cell cells 10 stacked in the Z direction. The fuel cell cell 10 is a polymer electrolyte fuel cell that generates electricity using a reaction gas. The reaction gas is, for example, oxygen as an oxidizing gas and hydrogen as a fuel gas. The fuel cell cell 10 includes an electrolyte membrane, an anode catalyst layer disposed on one side of the electrolyte membrane, a cathode catalyst layer disposed on the other side of the electrolyte membrane, a pair of gas diffusion layers disposed between the anode catalyst layer and the cathode catalyst layer, and a pair of separators disposed between the pair of gas diffusion layers.
[0010] The electrolyte membrane is a solid polymer membrane with proton conductivity. For example, the electrolyte membrane is an ion-exchange membrane made of fluororesin. The anode catalyst layer includes a catalyst that promotes the chemical reaction of the fuel gas and carbon particles supporting the catalyst. The cathode catalyst layer includes a catalyst that promotes the chemical reaction of the oxidizer gas and carbon particles supporting the catalyst. The gas diffusion layer is composed of a porous material. The porous material is manufactured from a metal or carbon material. The gas diffusion layer uniformly diffuses the reaction gas to the cathode catalyst layer and the anode catalyst layer. The electrolyte membrane, anode catalyst layer, cathode catalyst layer, and gas diffusion layer together are called a Membrane Electrode Gas Diffusion Layer Assembly (MEGA). A pair of separators are positioned to sandwich the Membrane Electrode Gas Diffusion Layer Assembly. Details of the separators will be described later.
[0011] The terminal plates 120 and 130 are positioned at both ends of the cell stack 110 in the stacking direction. The terminal plates 120 and 130 are made of conductive materials such as aluminum and copper. The terminal plates 120 and 130 are used to extract the electricity generated by the fuel cell cell 10 to the outside.
[0012] The fuel cell 100 is formed with oxidizer gas manifolds 11a and 11b, refrigerant manifolds 12a and 12b, and fuel gas manifolds 13a and 13b. Each of these manifolds is composed of manifold holes formed in the separator 200 and terminal plates 120 and 130, respectively. The oxidizer gas manifold 11a is used to supply oxidizer gas to the fuel cell 100. The oxidizer gas manifold 11b is used to discharge oxidizer gas from the fuel cell 100. The refrigerant manifold 12a is used to supply refrigerant to the fuel cell 100. The refrigerant manifold 12b is used to discharge refrigerant from the fuel cell 100. The fuel gas manifold 13a is used to supply fuel gas to the fuel cell 100. The fuel gas manifold 13b is used to discharge fuel gas from the fuel cell 100.
[0013] <Configuration of separator 200> Figure 2 is a plan view of the separator 200. The seal structure 500, which will be described later, is schematically shown in an enlarged view at the bottom of Figure 2. As shown at the bottom of Figure 2, the separator 200 has a structure in which a pair of plates 210 and 220 are joined facing each other. The plates 210 and 220 have a symmetrical structure. The plates 210 and 220 are made of a metal material or the like. Below, we will describe plate 210 of the two plates 210 and 220.
[0014] As shown in Figure 2, the plate 210 comprises a plate body portion 230 and a sealing structure portion 500.
[0015] <Configuration of the main body of the plate 230> The plate body portion 230 has a rectangular shape in plan view. The plate body portion 230 has six manifold holes 221a, 221b, 222a, 222b, 223a, and 223b formed therein. Manifold hole 221a is part of the oxidizer gas manifold 11a, manifold hole 221b is part of the oxidizer gas manifold 11b, manifold hole 222a is part of the refrigerant manifold 12a, manifold hole 222b is part of the refrigerant manifold 12b, manifold hole 223a is part of the fuel gas manifold 13a, and manifold hole 223b is part of the fuel gas manifold 13b.
[0016] The plate body 230 has a plurality of flow channels FP provided on the surface facing the membrane electrode gas diffusion layer, along the longitudinal direction (Y direction) of the plate body 230. Each flow channel FP is arranged along the short direction (X direction) of the plate body 230. A reaction gas flows through each flow channel FP. Each flow channel FP is formed by folding and bending the plate body 230 multiple times.
[0017] <Configuration of the seal structure 500> The seal structure 500 extends along the outer circumference of the plate body 230. More specifically, the seal structure 500 is located outside the area where the membrane electrode gas diffusion layer is positioned, when viewed in the thickness direction (Z direction) of the plate body 230. The seal structure 500 also protrudes from the plate body 230 in the thickness direction of the plate body 230. In a plan view, the seal structure 500 is provided so as to surround a portion of the manifold holes 221a, 221b, 222a, 222b, 223a, and 223b from the outside of the plate body 230. The seal structure 500 prevents leakage of refrigerant and reaction gas. The seal structure 500 also receives loads applied from other adjacent fuel cell cells.
[0018] The seal structure portion 500 in the present disclosure has a top portion 510 and a pair of connection portions 520 and 530. The top portion 510 is spaced apart from the plate main body portion 230 in the thickness direction. Further, the top portion 510 is provided parallel to the plate main body portion 230. The top portion 510 is provided in a strip shape and linearly when viewed in the thickness direction.
[0019] The connection portions 520 and 530 connect the plate main body portion 230 and the top portion 510 and are provided so as to sandwich the top portion 510. The connection portions 520 and 530 are inclined so as to approach each other as they separate from the plate main body portion 230. The boundaries B1 and B2 between the connection portions 520 and 530 and the plate main body portion 230 are linearly formed along the extending direction (Y direction) of the seal structure portion 500 when viewed in the thickness direction.
[0020] The connection portions 520 and 530 in the present embodiment have recesses GR. In FIG. 2, the recess GR of the connection portion 520 is not shown for illustration purposes, but actually, in the connection portion 520 as well, a recess GR is provided at the same position in the Y direction as the recess GR provided in the connection portion 530. The recess GR has a planar shape in which the width gradually narrows from the boundaries B1 and B2 toward the top portion 510. A plurality of recesses GR are provided along the Y direction.
[0021] In the present embodiment, the recess GR is formed such that the depth of the recess GR becomes deeper as it moves away from the side closer to the plate main body portion 230.
[0022] According to the fuel cell 10 of the embodiment described above, since the boundaries B1 and B2 between the connection portions 520 and 530 and the plate main body portion 230 are linearly formed when viewed in the thickness direction, the dimensional width of the seal structure portion 500 can be made smaller as compared with a configuration in which the boundaries B1 and B2 between the connection portions 520 and 530 and the plate main body portion 230 meander.
[0023] Furthermore, since at least one of the pair of connecting parts 520 and 530 has a recess GR, even if a compressive load is applied to the seal structure 500, the load can be distributed by the recess GR of the connecting parts 520 and 530, thereby improving the rigidity of the seal structure 500 compared to a configuration in which the connecting parts 520 and 530 do not have a recess GR.
[0024] B. Other embodiments: (B1) Figure 3 is a plan view of the seal structure 500b in another embodiment. In the above embodiment, the recesses GR provided in the connecting portions 520 and 530 were located at the same position along the Y direction, but the disclosure is not limited thereto. As shown in Figure 3, the recess GR1 provided in the connecting portion 520 and the recess GR2 provided in the connecting portion 530 may be provided alternately along the direction in which the seal structure 500b extends (Y direction). With this configuration, since the recesses GR1 and GR2 are provided alternately, the compressive load can be distributed more evenly between the connecting portions 520 and 530 compared to a configuration in which the recesses provided in each of the connecting portions 520 and 530 are located at the same position along the Y direction. This further improves the rigidity of the seal structure 500b.
[0025] (B2) In each of the above embodiments, the recesses GR, GR1, and GR2 were provided in both the connecting portions 520 and 530, but the disclosure is not limited thereto. The recesses GR, GR1, and GR2 may be provided in only one of the connecting portions 520 and 530. With such a configuration, the rigidity of the sealing structures 500 and 500b can be improved compared to a configuration in which the recesses GR, GR1, and GR2 are not provided in either of the connecting portions 520 and 530.
[0026] (B3) In each of the above embodiments, the recesses GR, GR1, and GR2 may be extended from the connecting portions 520 and 530 to the plate body portion 230.
[0027] (B4) In each of the above embodiments, the separator 200 was used in the fuel cell cell 10, but the disclosure is not limited thereto. The separator 200 may also be used in a water electrolysis cell.
[0028] (B5) In each of the above embodiments, the recesses GR, GR1, and GR2 are not limited to multiple, but may consist of only one. Also, in each of the above embodiments, the recesses GR, GR1, and GR2 may have any shape. For example, the depths of the recesses GR, GR1, and GR2 may be uniform.
[0029] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of Symbols]
[0030] 10…Fuel cell, 11a,11b…Oxidizer gas manifold, 12a,12b…Refrigerant manifold, 13a,13b…Fuel gas manifold, 100…Fuel cell, 110…Cell stack, 120,130…Terminal plate, 200…Separator, 210,220…Plate, 221a,221b,222a,222b,223a,223b…Manifold hole, 230…Plate body, 500,500b…Seal structure, 510…Top, 520,530…Connection part, B1,B2…Boundary, GR,GR1,GR2…Recess, FP…Flow path
Claims
[Claim 1] A fuel cell comprising a membrane electrode gas diffusion layer assembly and a pair of separators provided so as to sandwich the membrane electrode gas diffusion layer assembly, Each of the separators has a structure in which a pair of plates are joined together facing each other. Each of the aforementioned plates is The main body of the plate, A sealing structure extends along the outer circumference of the plate body and protrudes from the plate body in the thickness direction of the plate body, It has, The aforementioned sealing structure is A top portion is provided that is spaced apart from the plate body in the thickness direction and parallel to the plate body, A pair of connecting parts that connect the plate body and the top portion, and are provided so as to sandwich the top portion, wherein the boundary between the plate body and the connecting parts is formed in a straight line when viewed in the thickness direction, It has, Of the pair of connecting parts, at least one has a recess. Fuel cell.