Insulator

Abstract

To provide an insulator capable of improving manufacturability and rigidity. [Solution] The insulator 16 is provided on the fuel cell stack 1. The fuel cell stack 1 comprises a cell stack 10 formed by stacking a plurality of power generation cells 12 having an electrolyte membrane / electrode structure 20 and separators 24, 26, a terminal plate 15 provided at the end of the cell stack 10 in the stacking direction, an insulator 16, and an end plate 17. The terminal plate 15, the insulator 16, and the end plate 17 are provided in that order from the cell stack 10 side in the stacking direction, and the insulator 16 has a main body 60, a first rib 61 erected from the first surface 6a of the main body 60 facing the terminal plate 15, and a second rib 62 erected from the second surface 6b of the main body 60 facing the end plate 17.

Description

Technical Field

[0001] The present invention relates to an insulator.

Background Art

[0002] Conventionally, in order to ensure access to sustainable and advanced energy, research and development have been carried out on fuel cell stacks that contribute to energy efficiency. As a fuel cell stack, one including a cell stack formed by laminating a plurality of power generation cells each having an electrolyte membrane / electrode structure and a separator is known. At the end in the stacking direction of the cell stack, a terminal plate, an insulator, and an end plate are sequentially arranged outward.

[0003] A technique has been proposed to improve the sealing performance and heat insulation performance of a fuel cell stack by forming ribs on an insulator (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When forming ribs on an insulator, there has been a concern that the rib formation does not result in a desired shape, leading to a decrease in yield and productivity. Therefore, it is required to successfully form ribs with a high probability. By solving this problem, the productivity of the fuel cell stack is improved, and the rigidity and heat insulation performance are improved, which in turn contributes to energy efficiency.

Means for Solving the Problems

[0006] (1) The present invention relates to an insulator (e.g., insulator 16) provided in a fuel cell stack (e.g., fuel cell stack 1), wherein the fuel cell stack comprises a cell stack (e.g., cell stack 10) formed by stacking a plurality of power generation cells (e.g., power generation cell 12) having an electrolyte membrane / electrode structure (e.g., electrolyte membrane / electrode structure 20) and separators (e.g., a first metal separator 24 and a second metal separator 26), a terminal plate (e.g., terminal plate 15) provided at the end of the cell stack in the stacking direction, the insulator, and end The present invention relates to an insulator comprising a plate (for example, an end plate 17), wherein the terminal plate, the insulator, and the end plate are arranged in the order of the cell stacking body side in the stacking direction, and the insulator has a main body (for example, a main body 60), a first rib (for example, a first rib 61) erected from a first surface (for example, a first surface 6a) of the main body facing the terminal plate, and a second rib (for example, a second rib 62) erected from a second surface (for example, a second surface 6b) of the main body facing the end plate.

[0007] (2) Preferably, the first rib and the second rib are made of a single member.

[0008] (3) It is preferable that the first rib and the second rib have the same shape when viewed from the stacking direction.

[0009] (4) It is preferable that the first rib and the second rib are arranged at the same position when viewed from the stacking direction.

[0010] (5) It is preferable that a third rib (for example, a third rib 73) is erected on the surface of the end plate facing the insulator so as to contact the second rib.

[0011] (6) It is preferable that the second rib and the third rib have the same shape when viewed from the stacking direction.

[0012] (7) It is preferable that the second rib and the third rib are located at the same position when viewed from the stacking direction. [Effects of the Invention]

[0013] According to (1) above, when ribs are formed on both sides of the main body, the height of the first and second ribs is half that of the case when ribs are formed on only one side of the insulator. Therefore, even if the thickness of the insulator in the stacking direction is the same, the height of the first and second ribs will be lower when the first and second ribs are provided on the first and second surfaces respectively, compared to when the ribs are formed from only one side of the insulator. When forming ribs by injection molding, if long ribs are formed on only one side of the insulator, it is conceivable that the resin may not fill the entire recess of the mold in which the ribs are formed. However, when the first and second ribs are formed from the first and second surfaces of the main body, the depth of the recess in the mold becomes shallower, the resin fills to the end of the recess, and the manufacturability is improved. In addition, when stacking the cell stack, terminal plate, insulator, and end plate of the fuel cell stack, a load is applied. At this time, the first and second ribs need to have rigidity to withstand the applied surface pressure. By providing the first and second ribs on both sides of the main body, the height of the ribs is reduced compared to when the ribs are formed on only one side, improving the rigidity of the insulator. In addition, the formation of two air layers in the gap between the first and second ribs improves the thermal insulation performance.

[0014] According to (2) above, the insulator can be manufactured using a single mold, simplifying the manufacturing process and improving machinability. Furthermore, the first and second ribs do not shift, resulting in stable rigidity.

[0015] According to (3) above, it is possible to create a shape that is less prone to molding defects, thereby improving manufacturing efficiency.

[0016] According to (4) above, it is possible to create a shape that is less prone to molding defects, improving manufacturability and increasing rigidity.

[0017] According to the above (5), by abutting the second rib and the third rib against each other, an air layer is formed between the second rib and the third rib to improve the heat insulation property. Even if the third rib is provided on the end plate, sufficient rigidity and surface pressure can be ensured.

[0018] According to the above (6), the surface pressure obtained when the third rib is provided on the end plate can be ensured to the maximum extent.

[0019] According to the above (7), the surface pressure obtained when the third rib is provided on the end plate can be ensured to the maximum extent.

Brief Description of the Drawings

[0020] [Figure 1] It is a schematic diagram showing the fuel cell stack of this embodiment. [Figure 2] It is a schematic diagram showing the power generation cell of this embodiment. [Figure 3A] It is a plan view of the insulator of this embodiment as viewed from the first surface. [Figure 3B] It is a plan view of the insulator of this embodiment as viewed from the second surface. [Figure 3C] It is an enlarged cross-sectional view of the cut surface along the line A-A in FIG. 3B. [Figure 4] It is a plan view of the end plate of this embodiment as viewed from the surface facing the insulator. [Figure 5A] It is a plan view of the state where the insulator is stacked on the end plate of this embodiment. [Figure 5B] It is a schematic diagram of the cross section along the line C-C in FIG. 5A. [Figure 5C] It is a schematic diagram of the cross section along the line B-B in FIG. 5A.

Modes for Carrying Out the Invention

[0021] Embodiments of this disclosure will be described in detail below with reference to the drawings. Figure 1 is a schematic diagram showing the configuration of a fuel cell stack 1 in which the insulator 16 of this embodiment is provided. As shown in Figure 1, the fuel cell stack 1 includes a cell stack 10 composed of a plurality of cells 11 stacked on top of each other, a terminal plate 15 provided at the end of the cell stack 10 in the stacking direction, an insulator 16, and an end plate 17. The terminal plate 15, the insulator 16, and the end plate 17 are arranged in this order from the cell stack 10 side, from the inside to the outside. In this specification, the stacking direction is the direction in which the cells 11 constituting the cell stack 10, the terminal plate 15, the insulator 16, and the end plate 17 are stacked, and refers to the direction of arrow A in Figure 2.

[0022] First, let's describe the configuration of the cell stack 10. As schematically shown in Figure 2, the fuel cell stack 1 is configured so that oxidizer gas, fuel gas, and cooling medium can flow inside and outside the cell 11. The fuel cell stack 1 has an oxidizer gas supply channel 31, an oxidizer off-gas flow channel 32, a fuel gas supply channel 33, a fuel off-gas flow channel 34, a cooling medium supply channel 35, and a cooling medium discharge channel 36.

[0023] Cell 11 comprises a power generation cell 12 and a dummy cell 14. Multiple power generation cells 12 and dummy cells 14 are stacked to form a cell stack 10. Figure 2 is a diagram illustrating the configuration of the power generation cell 12. As shown in Figure 2, the power generation cell 12 comprises an electrolyte membrane / electrode structure 20 and a first metal separator 24 and a second metal separator 26 that sandwich the electrolyte membrane / electrode structure 20. Although not shown in the figure, sealing members such as gaskets are interposed between the electrolyte membrane / electrode structure 20 and the first metal separator 24 and the second metal separator 26, covering the periphery of various communication holes (described later) and the outer circumference of the electrode surface (power generation surface).

[0024] At one end edge of the power generation cell 12 in the direction of arrow B, an oxidizer gas supply port 31a for supplying an oxidizer gas, such as an oxygen-containing gas; a cooling medium discharge port 36b for discharging a cooling medium; and a fuel gas discharge port 34b for discharging a fuel gas, such as a hydrogen-containing gas, are provided, arranged in the direction of arrow C (up and down direction), communicating with each other in the direction of arrow A, which is the stacking direction.

[0025] At the other end edge of the power generation cell 12 in the direction of arrow B, a fuel gas supply communication hole 33a for supplying fuel gas, a cooling medium supply communication hole 35a for supplying cooling medium, and an oxidant gas discharge communication hole 32b for discharging oxidant gas are provided, arranged in the direction of arrow C, communicating with each other in the direction of arrow A.

[0026] The oxidant gas supply communication holes 31a formed in each power generation cell 12 form an oxidant gas supply channel 31 that supplies oxidant gas to the power generation cells 12 when multiple power generation cells 12 are stacked side by side as shown in Figure 1. The oxidant gas discharge communication holes 32b form an oxidant off-gas flow channel 32 through which the oxidant gas discharged from the power generation cells 12 flows when multiple power generation cells 12 are stacked side by side.

[0027] The fuel gas supply communication holes 33a formed in each power generation cell 12 form a fuel gas supply channel 33 that supplies fuel gas to the power generation cells 12 when multiple power generation cells 12 are stacked side by side. The fuel gas discharge communication holes 34b form a fuel off-gas flow channel 34 through which fuel off-gas discharged from the power generation cells 12 flows when multiple power generation cells 12 are stacked side by side.

[0028] The cooling medium supply communication holes 35a formed in each power generation cell 12 form a cooling medium supply channel 35 that supplies cooling medium to the first metal separator 24 and the second metal separator 26, which will be described later, when multiple power generation cells 12 are stacked side by side. The cooling medium discharge communication holes 36b form a cooling medium discharge channel 36 through which the cooling medium discharged from the first metal separator 24 and the second metal separator 26, which will be described later, flows.

[0029] The electrolyte membrane / electrode structure 20 comprises, for example, a solid polymer electrolyte membrane 21 in which water is impregnated into a thin film of perfluorosulfonic acid, and an anode electrode 22 and a cathode electrode 23 that sandwich the solid polymer electrolyte membrane 21 (see Figures 1 and 2).

[0030] The anode electrode 22 and cathode electrode 23 each have a gas diffusion layer made of carbon paper or the like, and an electrode catalyst layer in which porous carbon particles with a platinum alloy supported on their surface are uniformly coated on the surface of the gas diffusion layer. The electrode catalyst layers are bonded to both sides of the solid polymer electrolyte membrane 21 so that they face each other with the solid polymer electrolyte membrane 21 in between.

[0031] The first metal separator 24 and the second metal separator 26 are made of, for example, metal or carbon, and are arranged to sandwich the electrolyte membrane / electrode structure 20.

[0032] As shown in Figure 2, an oxidant gas flow groove 25 is provided on the surface 24a of the first metal separator 24 facing the electrolyte membrane / electrode structure 20, communicating with an oxidant gas supply communication hole 31a and an oxidant gas discharge communication hole 32b. The oxidant gas flow groove 25 is formed by creating multiple grooves extending in the direction of arrow B on the surface 24a of the first metal separator 24, allowing oxidant gas to flow between these grooves and the cathode electrode 23. Oxidant gas flows through the oxidant gas flow groove 25 in the direction of arrow B, receiving oxidant gas from the oxidant gas supply channel 31 and discharging it to the oxidant off-gas flow channel 32.

[0033] On the surface 26a of the second metal separator 26 facing the electrolyte membrane / electrode structure 20, a fuel gas flow groove 27 is formed, which communicates with the fuel gas supply communication hole 33a and the fuel gas discharge communication hole 34b. The fuel gas flow groove 27 is formed on the surface 26a of the second metal separator 26, with multiple grooves extending in the direction of arrow B, and is configured so that fuel gas flows between these grooves and the anode electrode 22. Fuel gas flows through the fuel gas flow groove 27 in the direction of arrow B, receiving fuel gas from the fuel gas supply passage 33 and discharging it to the fuel off-gas flow passage 34.

[0034] As shown in Figure 1, with multiple power generation cells 12 stacked, a cooling medium flow groove 37 is formed between the surfaces 24b of the first metal separator 24 and 26b of the second metal separator 26, communicating with a cooling medium supply communication hole 35a and a cooling medium discharge communication hole 36b. This cooling medium flow groove 37 is integrally formed extending in the direction of arrow B by overlapping multiple grooves provided in the first metal separator 24 and multiple grooves provided in the second metal separator 26. Cooling medium flows through the cooling medium flow groove 37 in the direction of arrow B, receiving cooling medium from the cooling medium supply passage 35 and discharging it to the cooling medium discharge passage 36.

[0035] As shown in Figure 1, the dummy cell 14 comprises a conductive plate 52 corresponding to the electrolyte membrane / electrode structure 20, and a dummy cell first metal separator 54 and a dummy cell second metal separator 56 that sandwich the conductive plate 52. The conductive plate 52 is made of, for example, a metal plate and is constructed substantially the same as the electrolyte membrane / electrode structure 20. However, the dummy cell 14 does not have the electrolyte membrane / electrode structure 20 and does not generate water through power generation.

[0036] The dummy cell first metal separator 54 and the dummy cell second metal separator 56 each have an oxidizer gas supply communication hole 31a, a cooling medium discharge communication hole 36b, a fuel gas discharge communication hole 34b, a fuel gas supply communication hole 33a, a cooling medium supply communication hole 35a, and an oxidizer gas discharge communication hole 32b. The oxidizer gas supply communication hole 31a, the cooling medium discharge communication hole 36b, and the fuel gas discharge communication hole 34b are provided on one end edge in the direction of arrow B of the dummy cell first metal separator 54 and the dummy cell second metal separator 56, arranged in the direction of arrow C (up and down). The fuel gas supply communication hole 33a, the cooling medium supply communication hole 35a, and the oxidizer gas discharge communication hole 32b are provided on the other end edge in the direction of arrow B of the dummy cell first metal separator 54 and the dummy cell second metal separator 56, arranged in the direction of arrow C. The dummy cell 14 allows water vapor flowing into the oxidizer gas supply channel 31 to flow through multiple grooves extending in the direction of arrow B provided in the dummy cell's first metal separator 54 and dummy cell's second metal separator 56, thereby preventing excessive water vapor from flowing into the power generation cell 12.

[0037] The cell stack 10 is supplied with a fuel gas such as hydrogen-containing gas, an oxidizing gas such as air or an oxygen-containing gas, and a cooling medium such as pure water, ethylene glycol, or oil.

[0038] As shown in Figure 2, in each power generation cell 12, fuel gas is introduced from the fuel gas supply communication hole 33a into the fuel gas flow groove 27 of the second metal separator 26 and moves along the anode electrode 22 that constitutes the electrolyte membrane / electrode structure 20. Oxidizing gas is introduced from the oxidizing gas supply communication hole 31a into the oxidizing gas flow groove 25 of the first metal separator 24 and moves along the cathode electrode 23 that constitutes the electrolyte membrane / electrode structure 20.

[0039] In the electrolyte membrane / electrode structure 20, the fuel gas supplied to the anode electrode 22 and the oxidizing gas supplied to the cathode electrode 23 are consumed by an electrochemical reaction within the electrode catalyst layer, generating electricity. In the catalyst layer of the anode electrode 22, electrons are removed from hydrogen in the fuel gas to produce hydrogen ions, which then conduct through the electrolyte membrane to the cathode side. Then, in the catalyst layer of the cathode electrode 23, hydrogen ions react with oxygen in the oxidizing gas to produce water. Thus, water is generated on the cathode side. A portion of the generated water moves to the anode side through the electrolyte membrane.

[0040] The oxidizer gas supplied to and consumed by the cathode electrode 23 is discharged in the direction of arrow A along the oxidizer gas discharge communication hole 32b. The fuel gas supplied to and consumed by the anode electrode 22 is discharged in the direction of arrow A along the fuel gas discharge communication hole 34b.

[0041] The cooling medium supplied to the cooling medium supply communication hole 35a is introduced into the cooling medium flow groove 37 between the first metal separator 24 and the second metal separator 26, and then flows along the direction of arrow B. After cooling the electrolyte membrane / electrode structure 20, this cooling medium is discharged from the cooling medium discharge communication hole 36b.

[0042] The terminal plate 15, insulator 16, and end plate 17 each have an oxidizer gas supply port 31a, a cooling medium discharge port 36b, and a fuel gas discharge port 34b arranged in the direction of arrow C (up and down) at one end edge in the direction of arrow B. Additionally, a fuel gas supply port 33a, a cooling medium supply port 35a, and an oxidizer gas discharge port 32b are provided at the other end edge in the direction of arrow B, arranged in the direction of arrow C. In other words, the terminal plate 15, insulator 16, and end plate 17 also have passages formed in the cell stack 10 (oxidizer gas supply passage 31, oxidizer off-gas flow passage 32, fuel gas supply passage 33, fuel off-gas flow passage 34, cooling medium supply passage 35, and cooling medium discharge passage 36), allowing each gas to flow through them. Figure 1 is a schematic side view of the fuel cell stack 1, and therefore these passages are not shown.

[0043] The terminal plate 15 is positioned at one end and the other end of the cell stack 10, sandwiching the cell stack 10. The terminal plate 15 is made of an electrically conductive material. The terminal plate 15 is, for example, a roughly rectangular plate-like member made of metal, and has terminal portions for extracting the electricity generated by the electrochemical reaction in the cell stack 10.

[0044] The insulator 16 is positioned alongside the terminal plate 15 on the outside in the stacking direction of the terminal plate 15. The insulator 16 is made of an insulating material such as polycarbonate or phenolic resin, and as shown in Figure 1, it is made thicker than the terminal plate 15 in the stacking direction. The insulator 16 insulates the terminal plate 15 from the end plate 17, which will be described below.

[0045] As shown in Figures 3A to 3C, the insulator 16 is formed with ribs that rise towards both the terminal plate 15 and the end plate 17. More specifically, the insulator 16 has a main body 60, a first surface 6a, a second surface 6b, a first rib 61, and a second rib 62.

[0046] As shown in Figures 3A and 3B, the main body 60 has a generally rectangular plate shape when viewed from the stacking direction and is positioned between the terminal plate 15 and the end plate 17. The main body 60 has a flow path peripheral region 162 and a rib-forming region 161. The flow path peripheral region 162 is the region in which holes for the gas flow path provided in the main body 60 are formed, and is located at one end and the other end in the longitudinal direction of the main body 60. The rib-forming region 161 is a substantially rectangular region located in the central part in the longitudinal direction of the main body 60, sandwiched between the pair of flow path peripheral regions 162.

[0047] The first surface 6a is the surface of the main body 60 that faces the terminal plate 15. The second surface 6b is the surface of the main body 60 that faces the end plate 17.

[0048] The first rib 61 is erected from the first surface 6a of the rib-forming region 161 and stands upright toward the terminal plate 15, as shown in Figure 3C. As shown in Figure 3A, the first rib 61 is arranged so that a series of hexagons are formed within the rib-forming region 161, forming a roughly honeycomb shape in a plan view from the stacking direction.

[0049] The second rib 62 is erected from the second surface 6b of the rib-forming region 161 and stands up toward the end plate 17, as shown in Figure 3C. As shown in Figure 3B, the second rib 62 is arranged so that a series of hexagons are formed within the rib-forming region 161, forming a roughly honeycomb shape in a plan view from the stacking direction.

[0050] The second rib 62 and the first rib 61 are composed of a single component and are formed continuously from the main body 60. For example, the second rib 62 and the first rib 61 are formed by resin injection molding. The second rib 62 and the first rib 61 have the same shape when viewed from the stacking direction and are positioned at the same location where they overlap with the main body 60 in between when viewed from the stacking direction. The heights of the second rib 62 and the first rib 61 from the first surface 6a and the second surface 6b of the main body 60 are the same. The sum of the thicknesses of the main body 60, the first rib 61 and the second rib 62 in the stacking direction becomes the insulation distance, which is the distance insulated by the insulator 16.

[0051] The end plate 17 is positioned on the outer side of the insulator 16 in the stacking direction, and is positioned alongside the insulator 16. The end plate 17 is located on the outermost part of the fuel cell stack 1 and is connected to a case (not shown) that houses the cell stack 10. The end plate has a roughly rectangular shape and is larger in external dimensions than the insulator 16. As shown in Figure 4, the end plate 17 has an end plate body portion 70, flow path peripheral ribs 731 and 732, reinforcing ribs 733, a third rib 73, and a body recess 72.

[0052] The end plate body portion 70 has a roughly plate-like shape. The end plate body portion 70 has an outer edge portion 171 and a rib-forming region 172. The outer edge portion 171 is located on the four edges of the end plate body portion 70 and is formed with screw holes, etc., that allow it to be attached to a case (not shown) that houses the fuel cell stack 1. The rib-forming region 172 is located inside the outer edge portion 171 and is a roughly rectangular area that is slightly smaller than the dimensions of the end plate body portion 70 itself.

[0053] As shown in Figure 4, the channel peripheral ribs 731 and 732 are positioned on one and the other sides of the longitudinal direction of the rib-forming region 172. The channel peripheral ribs 731 and 732 are formed in the area surrounding the holes of the gas channel formed in the end plate body 70. Specifically, the channel peripheral rib 731 is formed to surround the oxidizer gas supply communication hole 31a, the cooling medium discharge communication hole 36b, and the fuel gas discharge communication hole 34b, which are formed on one side of the end plate body 70. The channel peripheral rib 732 is formed to surround the fuel gas supply communication hole 33a, the cooling medium supply communication hole 35a, and the oxidizer gas discharge communication hole 32b. The channel peripheral ribs 731 and 732 stand upright from the end plate body 70 and have a surface that is continuous with the surroundings in a plan view. The reinforcing ribs 733 are formed to extend linearly along the shorter direction of the rib-forming region 172 in order to connect and reinforce the honeycomb-shaped third ribs 73, which will be described later. Multiple reinforcing ribs 733 are arranged on one side and the other side of the rib-forming region 172.

[0054] The third rib 73 is formed between the flow path peripheral ribs 731 and 732 on one and the other sides of the end plate body 70. Figures 5A to 5C show the insulator 16 placed on the inner surface of the end plate 17. For ease of explanation, the outer edge 171 of the end plate 17, the flow path peripheral ribs 731 and 732, the third rib 73, and the reinforcing rib 733 are shown in gray to distinguish them from the insulator 16. As shown in Figures 5B and 5C, the third rib 73 is positioned so that its end face abuts against the end face of the second rib 62 of the insulator 16. The third rib 73 has the same honeycomb shape as the first rib 61 and the second rib 62 when viewed from the stacking direction, and is positioned at the same location where it overlaps with the first rib 61 and the second rib 62 when viewed from the stacking direction. As shown in Figure 5C, the third rib 73, the first rib 61, and the second rib 62 are continuous in the stacking direction when viewed from the side in cross-section.

[0055] The main body recess 72 is a recessed portion between the outer edge 171 of the end plate main body 70 and the third rib 73, and also between the third ribs 73 themselves. The main body recess 72 creates an air layer between the end plate main body 70 and the insulator 16.

[0056] This embodiment provides the following effects. (1) An insulator 16 is provided on the fuel cell stack 1. The fuel cell stack 1 is composed of a cell stack 10, which is made up of multiple power generation cells 12 having an electrolyte membrane / electrode structure 20 and separators (first metal separator 24 and second metal separator 26) stacked on top of each other, a terminal plate 15 provided at the end of the cell stack 10 in the stacking direction, an insulator 16, and an end plate 17. The terminal plate 15, the insulator 16, and the end plate 17 are provided in that order from the cell stack 10 side in the stacking direction. The insulator 16 is composed of a main body 60, a first rib 61 erected from the first surface 6a of the main body 60 facing the terminal plate 15, and a second rib erected from the second surface 6b of the main body 60 facing the end plate 17.

[0057] When ribs are formed on both sides of the main body 60, the height of the first rib 61 and the second rib 62 is half that of the case where ribs are formed on only one side of the insulator 16. Therefore, even if the thickness of the insulator 16 in the stacking direction is the same, the height of the first rib 61 and the second rib 62 will be lower when the first rib 61 and the second rib 62 are provided on the first surface 6a and the second surface 6b, respectively, compared to when the ribs are formed from only one side of the insulator. When forming ribs by injection molding, if long ribs are formed on only one side of the insulator, it is conceivable that the resin may not fill the entire recess of the mold in which the ribs are formed. However, when the first rib 61 and the second rib 62 are formed from the first surface 6a and the second surface 6b of the main body 60, the depth of the recess of the mold becomes shallower, the resin fills to the end of the recess, and the manufacturability is improved. In addition, loads are applied when stacking the cell stack 10, terminal plate 15, insulator 16, and end plate 17 of the fuel cell stack 1. In this case, the first rib 61 and the second rib 62 must have sufficient rigidity to withstand the applied surface pressure. By providing the first rib 61 and the second rib 62 on both sides of the main body 60, the height of the ribs is reduced compared to when the ribs are formed on only one side, improving the rigidity of the insulator 16. In addition, the formation of two air layers in the gap between the first rib 61 and the second rib 62 also improves the heat insulation performance.

[0058] (2) The first rib 61 and the second rib 62 are made from a single component. This allows the insulator 16 to be manufactured using a single mold, simplifying the manufacturing process and improving machinability. In addition, the first rib 61 and the second rib 62 do not shift, providing stable rigidity.

[0059] (3) The first rib 61 and the second rib 62 are formed to have the same shape when viewed from the lamination direction. This makes it possible to create a shape that is less prone to molding defects and improves manufacturing efficiency.

[0060] (4) The first rib 61 and the second rib 62 are positioned at the same location when viewed from the lamination direction. This makes it possible to create a shape that is less prone to molding defects, improving manufacturability and increasing rigidity.

[0061] (5) A third rib 73 is provided on the surface of the end plate 17 facing the insulator 16 so as to abut against the second rib 62. By abutting the second rib 62 and the third rib 73 together, an air layer is formed between the second rib 62 and the third rib 73 to improve heat insulation, while ensuring sufficient rigidity and surface pressure even with the third rib 73 on the end plate 17.

[0062] (6) The second rib 62 and the third rib 73 have the same shape when viewed from the stacking direction. This makes it possible to maximize the surface pressure obtained when the third rib 73 is provided on the end plate 17.

[0063] (7) The second rib 62 and the third rib 73 are positioned at the same location when viewed from the stacking direction. This maximizes the surface pressure that can be obtained when the third rib 73 is provided on the end plate 17.

[0064] It should be noted that the present invention is not limited to the embodiments described above, and any modifications, improvements, etc., that can achieve the objectives of the present invention are included in the present invention. For example, although the first rib 61 and the second rib 62 were described as having a honeycomb shape, their shape is not limited. The first rib 61 and the second rib 62 may be lattice-shaped, circular, triangular, rhombic, etc., and a shape that improves rigidity is preferred. [Explanation of Symbols]

[0065] 1 Fuel cell stack 6a Front page 6b Second side 10-cell stack 12 power cells 15 Terminal Plate 16 Insulators 17 End Plate 20 Electrolyte membrane / electrode structure 24. First Metal Separator (Separator) 26. Second Metal Separator (Separator) 60 Main body 61 First Rib 62 Second Rib 73 Third Rib

Claims

1. An insulator provided in a fuel cell stack, The fuel cell stack comprises a cell stack in which multiple power generation cells having an electrolyte membrane, electrode structure and separator are stacked, The cell stack comprises a terminal plate provided at the end in the stacking direction of the cell stack, the insulator, and an end plate. The terminal plate, the insulator, and the end plate are provided in the order of the cell stacking body side in the stacking direction, The aforementioned insulator is The main body and A first rib is erected from the first surface of the main body facing the terminal plate, An insulator having a second rib erected from a second surface of the main body facing the end plate.

2. The insulator according to claim 1, wherein the first rib and the second rib are composed of a single member.

3. The insulator according to claim 1 or 2, wherein the first rib and the second rib have the same shape when viewed from the stacking direction.

4. The insulator according to claim 1 or 2, wherein the first rib and the second rib are arranged at the same position when viewed from the stacking direction.

5. The insulator according to claim 1, wherein a third rib is erected on the end plate facing the insulator so as to contact the second rib.

6. The insulator according to claim 5, wherein the second rib and the third rib have the same shape when viewed from the stacking direction.

7. The insulator according to claim 5 or 6, wherein the second rib and the third rib are arranged at the same position when viewed from the stacking direction.

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