fuel cells

Abstract

This invention provides a technology that can suppress the formation of gaps between the case and the distribution manifold in a fuel cell. [Solution] The fuel cell comprises a laminate having a plurality of fuel cell cells stacked in the stacking direction, a case for housing the laminate having one end formed on one end in the stacking direction and forming an opening, and a lid member having a through hole through which a fluid supplied to the laminate flows, and a lid member fastened to the one end of the case so as to cover the opening, wherein the lid member has a resin part and a metal part, and the metal part is in contact with the one end of the case.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to fuel cell technology.

BACKGROUND ART

[0002] Conventionally, in fuel cells, a technology is known that includes a case accommodating a fuel cell stack, and a distribution manifold (lid member) fastened to the case so as to close an opening of the case at one end of the case (for example, Patent Document 1). The distribution manifold has openings through which gas and cooling medium supplied to the fuel cell stack flow, and through which gas and cooling medium after passing through the fuel cell stack flow.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0003]

PATENT DOCUMENT 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] In conventional technology, the distribution manifold may be formed of a resin member. When the fuel cell is in operation, gases such as fuel gas and oxidant gas, and a coolant are supplied to the fuel cell stack, so the fuel cell stack may expand. Along with the expansion of the fuel cell stack, the distribution manifold located at the end of the fuel cell stack may also deform. When the distribution manifold deforms, a gap may be generated between the case and the distribution manifold. If a gap is generated between the case and the distribution manifold, water or the like may enter through this gap. Therefore, in fuel cells, a technology that can reduce the possibility of generating a gap between the case and the distribution manifold is desired.

MEANS FOR SOLVING THE PROBLEMS

[0005] The present disclosure can be implemented in the following forms.

[0006] (1) According to one embodiment of the present disclosure, a fuel cell is provided. The fuel cell comprises a laminate having a plurality of fuel cell cells stacked in a stacking direction, a case housing the laminate having one end formed on one end in the stacking direction and forming an opening, and a lid member having a through hole through which a fluid supplied to the laminate flows, and a lid member fastened to the one end of the case so as to cover the opening, wherein the lid member has a resin part and a metal part, and the metal part is in contact with the one end of the case. According to this embodiment, because the metal part of the lid member is in contact with the one end of the case, deformation of the metal part can be suppressed even if the laminate is deformed due to expansion or the like. As a result, the occurrence of a gap between the one end of the case and the metal part can be suppressed, and the possibility of water or the like entering the inside of the case from the outside can be reduced. (2) In the above embodiment, in a plan view of the lid member, the metal part has a peripheral part arranged around the resin part so as to surround the resin part, and the contact portion between the end of the case and the metal part may have a width greater than or equal to a predetermined value. According to this embodiment, the end of the case and the metal part can be brought into contact with a width greater than or equal to a predetermined value. This makes it possible to further suppress the occurrence of a gap between the end of the case and the metal part. (3) In the above embodiment, the case may further have an insulating sheet located between the plurality of fuel cell cells and the case, wherein one end of the case has a case-facing surface that contacts the metal part, an inner surface of the case end that is connected to the case-facing surface and forms part of the inner circumferential surface of the case, and a recess formed on the inner surface of the case end that is used for positioning the insulating sheet inside the case. (4) In the above embodiment, the case may be made of metal. This embodiment increases the rigidity of the case and suppresses deformation of the case itself. This further suppresses deformation of the metal part. This disclosure can be implemented in various forms, and in addition to the fuel cell described above, it can also be implemented in forms such as a method for manufacturing a fuel cell. [Brief explanation of the drawing]

[0007] [Figure 1] A cross-sectional view showing a schematic configuration of a fuel cell in one embodiment of the present disclosure. [Figure 2] Schematic diagram of the case and lid components. [Figure 3] A cross-sectional view showing an enlarged view of the lid member side of the fuel cell in Figure 1. [Figure 4] A schematic perspective view showing one end of the case. [Modes for carrying out the invention]

[0008] A. Embodiments: Figure 1 is a cross-sectional view showing the schematic configuration of a fuel cell 100 in one embodiment of the present disclosure. Figure 2 is a schematic diagram of the case 40 and the lid member 30. Figure 1 shows a cross-section of the fuel cell 100 along the stacking direction. In Figure 1, the Z-axis is parallel to the vertical direction, and the X-axis and Y-axis are parallel to the horizontal direction. The +Z direction is vertically upward, and the -Z direction is vertically downward. The stacking direction of the multiple fuel cell cells 10 is parallel to the X-axis. Note that the X-axis, Y-axis and Z-axis in Figure 1 are also shown in other figures as needed.

[0009] The fuel cell 100 comprises a laminate 20, a lid member 30 which also functions as an end plate and insulator, a case 40, a plurality of bolts 50, and an insulating sheet 90. The laminate 20 is composed of a plurality of fuel cell cells 10 stacked along the stacking direction. Specifically, the laminate 20 comprises a plurality of fuel cell cells 10, a pair of terminal plates 33, 34, an insulator 36, and an end plate 35. The pair of terminal plates 33, 34 are located on both sides of the plurality of fuel cell cells 10 in the stacking direction. The fuel cell cells 10 are solid polymer fuel cells. The fuel cell cells 10 generate electricity through an electrochemical reaction using reaction gas supplied to an anode-side catalyst electrode layer and a cathode-side catalyst electrode layer, which are provided with a solid polymer electrolyte membrane in between. In each fuel cell cell 10, a gas diffusion layer formed of a carbon porous material such as carbon paper and carbon cloth is arranged outside the catalyst electrode layer of each electrode. In addition, a conductive separator is arranged outside the gas diffusion layer of each electrode. Inside the fuel cell 100, multiple manifolds are formed parallel to the stacking direction for supplying reaction gas to each fuel cell cell 10, discharging off-gas from each fuel cell cell 10, and supplying and discharging cooling medium to each fuel cell cell 10.

[0010] The case 40 is substantially rectangular in shape and houses the laminate 20. The case 40 has one end 42 formed on the -X direction side of the stacking direction, another end 44 formed on the other end side of the stacking direction, and a surrounding wall 46 as shown in Figure 2. The surrounding wall 46 is composed of four walls that surround the laminate 20 with the stacking direction as the center. The four walls are a bottom wall, a top wall, and two side walls. The case 40 is made of metal. In this embodiment, the case is made of an aluminum alloy which has excellent waterproof, dustproof, and impact resistant properties.

[0011] As shown in Figures 1 and 2, one end 42 of the case forms a rectangular opening 49. The laminate 20 and the insulating sheet 90 (described later) are placed inside the case 40 through the opening 49. The other end 44 of the case faces the end plate 35. The other end 44 of the case has a shaft hole 47 through which a shaft 48 is inserted. The shaft 48 is airtightly inserted through the shaft hole 47. The shaft 48 pushes the end plate 35 in the -X direction, thereby adjusting the load on the laminate 20 in the stacking direction.

[0012] As shown in Figure 1, the lid member 30 is fastened to the case end 42 so as to cover the opening 49 of the case end 42. The lid member 30 is fastened to the case end 42 by a plurality of bolts 50, which are fastening members. The lid member 30 is in contact with the entire circumference of the case end 42 in the circumferential direction centered on the stacking direction.

[0013] As shown in Figure 2, the lid member 30 has a plurality of through holes 70 through which gas and cooling fluid supplied to the laminate 20 flow, or through which gas (off-gas) and cooling fluid that have passed through the laminate 20 flow. The plurality of through holes 70 penetrate the lid member 30 in the stacking direction. There are six plurality of through holes 70. The plurality of through holes 70 are passage holes for fuel gas and fuel off-gas, passage holes for oxidizer gas and oxidizer off-gas, or passage holes for the cooling medium that is supplied or discharged.

[0014] The lid member 30 comprises a metal part 31 and a resin part 32. The metal part 31 is a metal plate-shaped member. The metal part 31 has higher rigidity than the resin part 32. In this embodiment, the metal part 31 is made of an aluminum alloy. However, the metal part 31 may be made of any metal other than aluminum alloy, such as a titanium alloy or stainless steel. The resin part 32 is a layer formed on the metal part 31. The resin part 32 is formed on the surface of the portion of the metal part 31 that demarcates the through hole 70, and on the surface of the portion that contacts the terminal plate 34 in the direction opposite to the stacking direction. The resin part 32 is a member that has insulating and corrosion-resistant properties. For example, the resin part 32 is made of an insulating polymer material, such as polyolefin such as polypropylene (PP), or engineering plastic such as polyamide (PA) or polyphenylene sulfide (PPS). Aromatic polyamide or polyphenylene sulfide (PPS) can be used as a suitable material for the resin part 32. In a plan view of the lid member 30 as seen from a direction along the stacking direction, the metal part 31 has a peripheral part 37 that surrounds the resin part 32 and is also located around the resin part 32. As shown in Figure 1, the lid member 30 is attached to the case 40 by bolts 50 with the peripheral part 37 of the metal part 31 in airtight contact with the end part 42 of the case. Details of the end part 42 of the case and the lid member 30 will be described later.

[0015] The insulating sheet 90 shown in Figure 1 is placed between the laminate 20 and the surrounding wall 46 of the case 40. In this embodiment, the insulating sheet 90 is placed on the surrounding wall 46, i.e., the top wall, bottom wall, and two side walls of the case 40. The insulating sheet 90 is a member for insulating between the laminate 20 and the case 40. The insulating sheet 90 is made of an electrically insulating organic material, such as resin or rubber. A shock-absorbing cushioning member, such as a foamed material, may be placed between the insulating sheet 90 and the case 40.

[0016] Figure 3 is an enlarged cross-sectional view showing the configuration of the lid member 30 side of the fuel cell 100 as shown in Figure 1. Figure 4 is a schematic perspective view showing the case end 42 side of the case 40. As shown in Figure 3, the resin part 32 is formed on the surface of the metal part 31 that demarcates the through hole 70 and on the surface that is in contact with the terminal plate 34. A through hole 418 is formed in the case facing surface 42fa through which the bolt 50 is inserted.

[0017] As shown in Figure 3, the through-hole 70 communicates with the manifold 21 formed in the laminate 20. The manifold 21 serves as a supply channel or discharge channel for oxidizer gas, fuel gas, or cooling medium.

[0018] The metal part 31 and the case end 42 are fixed together by bolts 50, with the lid-facing surface 37fa of the peripheral portion 37 facing the case 40 and the case-facing surface 42fa of the case end 42 facing the peripheral portion 37 in contact with each other. The resin part 32 is not in contact with the case-facing surface 42fa of the case end 42. In a plan view, the case end 42 is the portion that protrudes outward from the peripheral wall 46 connecting the case end 42 and the other end 44 of the case. The contact portion CP between the case-facing surface 42fa of the case end 42 and the lid-facing surface 37fa of the metal part 31 has a width Wa of a predetermined value or greater. Preferably, the predetermined value is set to a value that ensures the contact area of ​​the contact portion CP necessary to airtightly seal the case 40 and the lid member 30. An annular sealing member may also be placed between the case-facing surface 42fa and the lid-facing surface 37fa. The annular sealing member may be placed in a groove formed on either the case-facing surface 42fa or the lid-facing surface 37fa.

[0019] As shown in FIG. 3 and FIG. 4, the case one end portion 42 has a case one end inner surface 412 in addition to the case opposing surface 42fa that comes into contact with the metal portion 31. The case one end inner surface 412 is connected to the case opposing surface 42fa and forms a part of the inner peripheral surface of the case 40. The case one end inner surface 412 is a portion of the case one end portion 42 that forms the inner peripheral surface of the case 40. Recesses 414 are respectively formed in the -Z direction side surface 412a and the +Z direction side surface 412b of the case one end inner surface 412. Two recesses 414 are formed on the surface 412a, and two recesses 414 are formed on the surface 412b. The two recesses 414 on each of the surfaces 412a and 412b are formed at intervals in the Y direction. The two recesses 414 on the surface 412a and the two recesses 414 on the surface 412b are arranged at positions facing each other in the Z direction. The recesses 414 are used for positioning the insulating sheet 90 into the case 40 when arranging the insulating sheet 90 at a predetermined position in the case 40. Specifically, pins serving as positioning marks are arranged in the recesses 414. Using the pins arranged in the recesses 414 as positioning marks, the insulating sheet 90 is arranged at a predetermined position in the case 40 using a jig. After the insulating sheet 90 is arranged at the predetermined position in the case 40, the pins in the recesses 414 are removed.

[0020] According to the above embodiment, since the metal portion 31 of the lid member 30 is in contact with the case one end portion 42 of the case 40, even when the laminate 20 is deformed due to expansion or the like, deformation of the metal portion 31, which has higher rigidity than the resin portion 32, can be suppressed. As a result, the occurrence of a gap between the case one end portion 42 and the metal portion 31 can be suppressed, so that the possibility of water or the like entering the inside of the case 40 from the outside can be reduced. Further, according to the above embodiment, by bringing the case one end portion 42 and the metal portion 31 into contact with each other with a width Wa equal to or larger than a predetermined value, the occurrence of a gap between the case one end portion 42 and the metal portion 31 can be further suppressed. In addition, since the contact portion CP has the width Wa equal to or larger than the predetermined value, the region (for example, the depth) for forming the recess 414 shown in FIG. 4 can be secured. Further, the insulating sheet 90 can be easily positioned relative to the case 40 using the recess 414. Further, according to the above embodiment, since the case 40 is made of metal, the rigidity can be increased compared to a case made of resin. Accordingly, deformation of the case 40 itself can be suppressed, so that deformation of the metal portion 31 can be further suppressed. Thereby, the possibility of a gap being generated between the case 40 and the metal portion 31 can be further reduced. Further, according to the above embodiment, since the deformation of the metal portion 31 is suppressed, application of a fluctuating load to the bolt 50 that fastens the metal portion 31 and the case 40 can be suppressed, so that the possibility of fatigue fracture of the bolt 50 occurring can be reduced.

[0021] The present disclosure is not limited to the above-described embodiments, and can be implemented in various configurations without departing from the spirit thereof. For example, the technical features of the embodiments corresponding to the technical features in each form described in the Summary of the Invention section can be appropriately replaced or combined in order to solve part or all of the above-described problems, or to achieve part or all of the above-described effects. Further, if the technical feature is not described as essential in the present specification, it can be appropriately deleted. [Description of Reference Numerals]

[0022] 10...Fuel cell, 20...Laminate, 21...Manifold, 30...Lid member, 31...Metal part, 32...Resin part, 34...Terminal plate, 35...End plate, 36...Insulator, 37...Peripheral part, 37fa...Lid opposing surface, 40...Case, 42...One end of case, 42fa...Facing surface of case, 44...Other end of case, 46...Peripheral wall, 47...Shaft hole, 48...Shaft, 49...Opening, 50...Bolt, 70...Through hole, 90...Insulating sheet, 100...Fuel cell, 412...Inner surface of one end of case, 412a...Surface, 412b...Surface, 414...Recess, 418...Through hole, CP...Contact part, Wa...Width

Claims

1. It is a fuel cell, A laminate having multiple fuel cell cells stacked in the stacking direction, A case for housing the laminate, the case having one end formed on one end in the stacking direction and forming an opening, A lid member having a through hole through which a fluid supplied to the laminate flows, the lid member being fastened to one end of the case so as to cover the opening, The lid member has a resin part and a metal part. A fuel cell in which the aforementioned metal part is in contact with one end of the case.

2. A fuel cell according to claim 1, In a plan view of the lid member, the metal portion has a peripheral portion arranged around the resin portion so as to surround the resin portion. A fuel cell in which the contact portion between one end of the case and the metal part has a width greater than or equal to a predetermined value.

3. A fuel cell according to claim 2, further, The plurality of fuel cell cells and the case are separated by an insulating sheet, One end of the aforementioned case is The case-facing surface that comes into contact with the aforementioned metal part, The inner surface of one end of the case, which is connected to the opposing surface of the case and forms a part of the inner circumferential surface of the case, A fuel cell having a recess formed on the inner surface of one end of the case, which is used for positioning the insulating sheet inside the case.

4. A fuel cell according to claim 1, The aforementioned case is made of metal and is a fuel cell.

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