Flow channel component and substrate for manufacturing flow channel component

Abstract

To provide a flow channel component with excellent water retention and / or cooling efficiency, a substrate for manufacturing a flow channel component used to manufacture the flow channel component, and a gasket with high adhesiveness to prevent leakage of fluid.SOLUTION: A flow channel component has a metal base material having a first surface and a second surface located on the opposite side of the first surface, and a flow channel portion extending in a first direction in the plane of the first surface of the metal base material, and a rough surface is formed on the first surface of the metal base material at least in an area surrounding the outer edge of the flow channel portion, and the arithmetic mean surface roughness Ra is in the range of 0.1 μm to 0.5 μm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a flow path member and a substrate for manufacturing a flow path member. [Background technology]

[0002] Polymer electrolyte fuel cells (PEFCs) are used in electric vehicles, small-scale power generation systems for home use, and the like. Polymer electrolyte fuel cells have a stack structure in which a plurality of fuel cells, each having a membrane electrode assembly (MEA) and a separator, are stacked. The membrane electrode assembly generally has a configuration in which a catalyst layer and a gas diffusion layer (GDL) are stacked in this order on both sides of a solid polymer electrolyte membrane. The separator is provided in contact with the gas diffusion layer, and is used to supply reactant gas (fuel gas such as hydrogen in the anode-side separator, and oxidant gas such as air (or oxygen) in the cathode-side separator) to the gas diffusion layer and to collect current, and has a gas flow path with an uneven shape. The fine uneven shape of the separator is generally formed by pressing a thin metal plate using a fine unevenness forming die (see Patent Document 1). In addition to the gas flow path, which is a flow path for the reactant gas, the separator is formed with a refrigerant flow path, supply manifold holes for supplying fluids such as the reactant gas and the refrigerant, and exhaust manifold holes for exhausting the fluids. Therefore, gaskets are provided around the gas flow path, the refrigerant flow path, the supply manifold holes, and the exhaust manifold holes to prevent leakage of the fluids. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-282728 A [Patent Document 2] JP 2018-73491 A Summary of the Invention [Problem to be solved by the invention]

[0004] The power generation efficiency of a polymer electrolyte fuel cell is affected by the amount of water in the solid polymer electrolyte membrane. If the solid polymer electrolyte membrane is dry, the ionic conductivity decreases, and the power generation efficiency is impaired. On the other hand, if the water generated in a polymer electrolyte fuel cell is not discharged, the supply of reactant gas through the separator flow path is impeded, and the power generation efficiency is impaired. Therefore, there is a demand for a separator that can sufficiently discharge the generated water through the separator flow path and can retain water in preparation for the drying of the solid polymer electrolyte membrane.

[0005] In a polymer electrolyte fuel cell, a reaction takes place on the anode side that converts hydrogen into hydrogen ions and electrons. The hydrogen ions move through the solid polymer electrolyte membrane to the cathode side, where a reaction takes place to produce water from oxygen, hydrogen ions, and electrons. To prevent the fuel cell from operating above a certain temperature range due to Joule heat or reaction heat from the water-producing reaction at the cathode, a refrigerant flow passage is formed in the separator through which a refrigerant (usually cooling water) flows, and the fuel cell is cooled by the refrigerant. There is a demand for improved cooling efficiency by the refrigerant in polymer electrolyte fuel cells.

[0006] If the adhesion of the gasket to the separator is poor, there is a problem of leakage of fluids such as reaction gases and coolants. In particular, in a polymer electrolyte fuel cell, operation and shutdown are frequently repeated during operation, and the gasket can frequently shrink and expand due to heat generated by chemical reactions, so there is a growing demand for a technology that can effectively improve the adhesion of the gasket.

[0007] In view of the above problems, the present disclosure aims to provide a flow path member having excellent water retention and / or cooling efficiency, and a flow path member manufacturing substrate used for manufacturing the flow path member. Another aim of the present disclosure is to provide a flow path member having high adhesion of a gasket and capable of preventing leakage of a fluid. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, one embodiment of the present disclosure provides a flow path member comprising a metal substrate having a first surface and a second surface located opposite the first surface, and a flow path portion extending in a first direction within the plane of the first surface of the metal substrate, wherein a rough surface is formed on the first surface of the metal substrate at least in an area surrounding an outer edge of the flow path portion, and the arithmetic mean surface roughness Ra of the rough surface is in the range of 0.1 μm to 0.5 μm.

[0009] As one embodiment of the present disclosure, there is provided a flow path member comprising: a metal substrate having a first surface and a second surface located opposite the first surface; and a flow path portion extending in a first direction within the plane of the first surface of the metal substrate, wherein the first surface of the metal substrate has a through hole portion formed therein that penetrates in the thickness direction of the metal substrate at least in an area surrounding an outer edge of the flow path portion, and the opening dimension of the opening of the through hole portion on the first surface side of the metal substrate is equal to or greater than 1 / 2 of the thickness of the metal substrate.

[0010] As one embodiment of the present disclosure, there is provided a flow path member comprising a metal substrate having a first surface and a second surface located opposite the first surface, and a flow path portion extending in a first direction within the plane of the first surface of the metal substrate, wherein the first surface of the metal substrate has fine recesses formed in at least an area surrounding the outer edge of the flow path portion, and the opening dimension of the opening of the fine recesses is less than 1 / 4 of the thickness of the metal substrate.

[0011] As one embodiment of the present disclosure, there is provided a flow path member which is formed by bending a substrate, and which comprises alternating parallel arrangements of concave and convex portions extending in a predetermined direction, wherein groove portions are formed in at least some of the corners of the concave and convex portions, and the shape of the groove portions is such that the maximum width within the groove portions is greater than the opening width of the groove portions.

[0012] As one embodiment of the present disclosure, there is provided a substrate for manufacturing a flow path member, the substrate being used for manufacturing the flow path member having concave and convex portions arranged alternately in parallel and extending in a predetermined direction, the substrate comprising a base material having a first surface and a second surface positioned opposite the first surface, and a groove portion formed on the first surface and / or the second surface, the groove portion being formed at a position corresponding to at least a portion of the corners of the concave portions and the convex portions of the flow path member. Effect of the Invention

[0013] According to the present disclosure, it is possible to provide a flow path member having excellent water retention and / or cooling efficiency, as well as a flow path member manufacturing substrate used for manufacturing the flow path member, and a flow path member having high adhesion to a gasket and capable of preventing fluid leakage. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a plan view showing a schematic configuration of a flow path member according to an embodiment of the present disclosure, the flow path member being provided on the anode side of a fuel cell. [Diagram 2] FIG. 2 is a plan view showing a schematic configuration of a flow path member according to an embodiment of the present disclosure, the flow path member being provided on the cathode side of a fuel cell. [Diagram 3] FIG. 3 is an enlarged cross-sectional end view taken along line AA in FIG. 1, showing a schematic configuration of a flow path member according to an embodiment of the present disclosure. [Figure 4A] FIG. 4A is a partially enlarged cutaway end view showing a schematic configuration of a rough surface in an embodiment of the present disclosure. [Figure 4B] FIG. 4B is a partially enlarged cutaway end view showing a schematic configuration of a recess in the embodiment of the present disclosure. [Figure 4C] FIG. 4C is a partially enlarged cross-sectional end view showing a schematic configuration of one aspect of a through-hole portion according to the embodiment of the present disclosure. [Figure 4D] FIG. 4D is a partially enlarged cross-sectional end view showing a schematic configuration of another aspect of the through-hole portion in the embodiment of the present disclosure. [Figure 4E]FIG. 4E is a partially enlarged cutaway end view showing a schematic configuration of a minute recess in accordance with an embodiment of the present disclosure. [Figure 4F] FIG. 4F is an enlarged, partially cutaway end view showing a schematic configuration of a combination of a rough surface and a recess in accordance with an embodiment of the present disclosure. [Figure 4G] FIG. 4G is a partially enlarged cutaway end view showing a schematic configuration of one embodiment of a combination of a rough surface and a through-hole portion according to the embodiment of the present disclosure. [Figure 4H] FIG. 4H is a partially enlarged cross-sectional end view showing a schematic configuration of another aspect of a combination of a rough surface and a through-hole portion according to an embodiment of the present disclosure. [Figure 4I] FIG. 4I is a partially enlarged cutaway end view showing a schematic configuration of a combination of a rough surface and fine recesses in an embodiment of the present disclosure. [Figure 5A] FIG. 5A is a partially enlarged cutaway end view illustrating one step of a manufacturing method of a flow path member according to an embodiment of the present disclosure. [Figure 5B] FIG. 5B is a partially enlarged cutaway end view illustrating a step following FIG. 5A in a manufacturing method of a flow path member according to an embodiment of the present disclosure. [Figure 5C] FIG. 5C is a partially enlarged cutaway end view illustrating a step following FIG. 5B in a manufacturing method of a flow path member according to an embodiment of the present disclosure. [Figure 5D] FIG. 5D is a plan view illustrating a step following FIG. 5C in a manufacturing method of a flow path member according to an embodiment of the present disclosure. [Figure 5E] FIG. 5E is a partially enlarged cutaway end view illustrating a step following FIG. 5D in a manufacturing method of a flow path member according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a cross-sectional view showing a schematic configuration of a fuel cell according to an embodiment of the present disclosure. [Figure 7] FIG. 7 is an exploded perspective view illustrating a stacked state of a membrane electrode assembly, a gasket, and a flow path member of a fuel cell according to an embodiment of the present disclosure. [Figure 8]FIG. 8 is a partial cross-sectional view showing a schematic configuration of a first embodiment of a substrate for manufacturing a fuel cell flow path member according to an embodiment of the present disclosure. [Figure 9] FIG. 9 is a partial cross-sectional view showing a schematic configuration of a second embodiment of a substrate for manufacturing a fuel cell flow path member according to an embodiment of the present disclosure. [Figure 10] FIG. 10 is a partial cross-sectional view showing a schematic configuration of a third embodiment of a substrate for manufacturing a fuel cell flow path member according to an embodiment of the present disclosure. [Figure 11] FIG. 11 is a partial cross-sectional view showing a schematic configuration of a fourth embodiment of a substrate for manufacturing a fuel cell flow path member according to an embodiment of the present disclosure. [Figure 12] FIG. 12 is a partial cross-sectional view showing a schematic configuration of a fifth embodiment of a substrate for manufacturing a fuel cell flow path member according to an embodiment of the present disclosure. [Figure 13] FIG. 13 is a perspective view showing a schematic configuration of another aspect of the substrate for manufacturing a fuel cell flow path member according to an embodiment of the present disclosure. [Figure 14A] FIG. 14A is a cross-sectional view showing a step of a method for manufacturing a substrate for manufacturing a fuel cell flow path member according to an embodiment of the present disclosure. [Figure 14B] FIG. 14B is a cross-sectional view showing a step of a method for manufacturing a fuel cell flow path member according to an embodiment of the present disclosure, which is a step subsequent to the step shown in FIG. 14A. [Figure 14C] FIG. 14C is a cross-sectional view showing a step of a method for manufacturing a fuel cell flow path member according to an embodiment of the present disclosure, which is a step subsequent to the step shown in FIG. 14B. [Figure 14D] FIG. 14D is a cross-sectional view showing a step of a method for manufacturing a fuel cell flow path member according to an embodiment of the present disclosure, the step following the step shown in FIG. 14C. [Figure 15] FIG. 15 is a partial cross-sectional view showing a schematic configuration of a flow path member for a fuel cell according to an embodiment of the present disclosure, manufactured from the fuel cell flow path member manufacturing substrate shown in FIG. [Figure 16]FIG. 16 is a partial cross-sectional end view showing a schematic configuration of a flow path member for a fuel cell according to an embodiment of the present disclosure, manufactured from the fuel cell flow path member manufacturing substrate shown in FIG. [Figure 17] FIG. 17 is a partial cross-sectional end view showing a schematic configuration of a flow path member for a fuel cell according to an embodiment of the present disclosure, manufactured from the fuel cell flow path member manufacturing substrate shown in FIG. [Figure 18] FIG. 18 is a partial cross-sectional view showing a schematic configuration of a flow path member for a fuel cell according to an embodiment of the present disclosure, manufactured from the fuel cell flow path member manufacturing substrate shown in FIG. [Figure 19] FIG. 19 is a partial cross-sectional end view showing a schematic configuration of a flow path member for a fuel cell according to an embodiment of the present disclosure, manufactured from the fuel cell flow path member manufacturing substrate shown in FIG. [Figure 20] FIG. 20 is a perspective view showing a schematic configuration of a flow path member for a fuel cell according to an embodiment of the present disclosure, manufactured from the fuel cell flow path member manufacturing substrate shown in FIG. [Figure 21A] FIG. 21A is a partial cutaway end view showing a schematic configuration of a groove portion of a fuel cell flow path member according to an embodiment of the present disclosure. [Figure 21B] FIG. 21B is a partial cutaway end view showing a schematic configuration of a groove portion of a fuel cell flow path member according to an embodiment of the present disclosure. [Figure 22A] FIG. 22A is a cross-sectional end view showing a step of a manufacturing method of a fuel cell flow path member according to an embodiment of the present disclosure. [Figure 22B] FIG. 22B is a cross-sectional end view showing a step of a method for manufacturing a fuel cell flow path member according to an embodiment of the present disclosure, which is a step subsequent to the step shown in FIG. 22A. [Figure 23] FIG. 23 is a cross-sectional view showing a schematic configuration of a fuel cell according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] An embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the shape, scale, aspect ratio, etc. of each part may be shown modified or exaggerated from the actual product to facilitate understanding. In this specification, etc., a numerical range expressed using "~" means that the range includes the numerical values ​​written before and after "~" as the lower and upper limits, respectively. In this specification, etc., terms such as "film," "sheet," and "plate" are not distinguished from each other based on differences in names. For example, "plate" is a concept that includes members that can be generally called "sheet" and "film."

[0016] Aspect 1 of this embodiment is a flow path member comprising a metal substrate having a first surface and a second surface located opposite the first surface, and a flow path portion extending in a first direction within the plane of the first surface of the metal substrate, wherein a rough surface is formed on the first surface of the metal substrate at least in an area surrounding the outer edge of the flow path portion, and the arithmetic mean surface roughness Ra of the rough surface is in the range of 0.1 μm to 0.5 μm.

[0017] Aspect 2 of this embodiment is the flow path member according to Aspect 1 above, which has a recess formed in the region, and the rough surface is formed on at least a part of the surface of the recess.

[0018] Aspect 3 of this embodiment is the flow path member according to Aspect 2 above, wherein the opening dimension of the opening of the recess is in the range of 1 / 4 to 1 / 2 the thickness of the metal base.

[0019] Aspect 4 of this embodiment is a flow path member in any one of aspects 1 to 3 above, which includes a through hole portion formed in the region, penetrating through the thickness direction of the metal substrate, and the rough surface is formed on at least a portion of the side surface of the through hole portion.

[0020] Aspect 5 of this embodiment is a flow path member in any one of Aspects 1 to 4 above, which has fine recesses formed in the region, the opening dimension of the opening of the fine recesses is less than 1 / 4 of the thickness of the metal substrate, and the rough surface is formed on at least a portion of the surface of the fine recesses.

[0021] Aspect 6 of the present embodiment is a flow path member in which, in any one of Aspects 1 to 5 above, the metal substrate is formed with a supply manifold hole that supplies a fluid to the flow path portion and a discharge manifold hole that discharges the fluid from the flow path portion, and the region is a region that surrounds the outer edge of the flow path portion and the outer edges of the supply manifold hole and the discharge manifold hole.

[0022] Aspect 7 of this embodiment is a flow path member comprising a metal substrate having a first surface and a second surface located opposite the first surface, and a flow path portion extending in a first direction within the plane of the first surface of the metal substrate, wherein a through hole portion penetrating through the thickness direction of the metal substrate is formed on the first surface of the metal substrate at least in a region surrounding the outer edge of the flow path portion, and the opening dimension of the opening of the through hole portion on the first surface side of the metal substrate is equal to or greater than 1 / 2 of the thickness of the metal substrate.

[0023] Aspect 8 of the present embodiment is the flow path member according to aspect 7 above, wherein an opening dimension of the opening of the through-hole portion on the first surface side of the metal base is equal to or larger than a thickness of the metal base.

[0024] A ninth aspect of the present embodiment is the flow path member according to the seventh or eighth aspect, wherein at least a part of a side surface of the through-hole portion is roughened.

[0025] Aspect 10 of the present embodiment is a flow path member in any one of aspects 7 to 9 above, which has a recess formed in the region, and the opening dimension of the opening of the recess is in the range of 1 / 4 to 1 / 2 of the thickness of the metal substrate.

[0026] Aspect 11 of the present embodiment is a flow path member in any one of aspects 7 to 10 above, which has fine recesses formed in the region, and the opening dimension of the opening of the fine recesses is less than 1 / 4 of the thickness of the metal substrate.

[0027] Aspect 12 of this embodiment is a flow path member in which, in any one of Aspects 7 to 11 above, the metal substrate is formed with a supply manifold hole that supplies a fluid to the flow path portion and a discharge manifold hole that discharges the fluid from the flow path portion, and the region is a region that surrounds the outer edge of the flow path portion and the outer edges of the supply manifold hole and the discharge manifold hole.

[0028] Aspect 13 of this embodiment is a flow path member comprising a metal substrate having a first surface and a second surface located opposite the first surface, and a flow path portion extending in a first direction within the plane of the first surface of the metal substrate, wherein fine recesses are formed on the first surface of the metal substrate at least in an area surrounding the outer edge of the flow path portion, and the opening dimension of the opening of the fine recess is less than 1 / 4 of the thickness of the metal substrate.

[0029] A fourteenth aspect of the present embodiment is the flow path member according to the thirteenth aspect, wherein a rough surface is formed on at least a part of the surface of the fine recesses.

[0030] A fifteenth aspect of the present embodiment is a flow path member according to the thirteenth or fourteenth aspect above, which has a through-hole portion formed in the region and penetrating the metal base in the thickness direction.

[0031] Aspect 16 of the present embodiment is a flow path member in any one of aspects 13 to 15 above, which has a recess formed in the region, and the opening dimension of the opening of the recess is in the range of 1 / 4 to 1 / 2 of the thickness of the metal substrate.

[0032] Aspect 17 of the present embodiment is a flow path member in which, in any one of Aspects 13 to 16 above, the metal substrate is formed with a supply manifold hole that supplies a fluid to the flow path portion and a discharge manifold hole that discharges the fluid from the flow path portion, and the region is a region that surrounds the outer edge of the flow path portion and the outer edges of the supply manifold hole and the discharge manifold hole.

[0033] Aspect 18 in this embodiment is a flow path member formed by bending a substrate, and consisting of alternating parallel arrangements of concave and convex portions extending in a predetermined direction, in which groove portions are formed in at least some of the corners of the concave and convex portions, and the shape of the groove portions is such that the maximum width within the groove portions is greater than the opening width of the groove portions.

[0034] Aspect 19 of this embodiment is the flow path member according to Aspect 18 above, wherein the grooves are formed on at least a portion of the inside of the corners of the recesses and the protrusions.

[0035] Aspect 20 of the present embodiment is the flow path member according to Aspect 18 or 19 above, wherein the grooves are formed on at least a portion of the outer sides of the corners of the recesses and the protrusions.

[0036] Aspect 21 of this embodiment is a flow path member in any one of Aspects 18 to 20 above, wherein the groove portion is formed in at least a portion of the inside of the corners of the recesses and protrusions and at least a portion of the outside of the corners.

[0037] Aspect 22 of the present embodiment is a flow path member in which, in any of Aspects 18 to 21 above, the recess and the protrusion each include a first plane and a second plane located opposite the first plane, and the groove is formed in at least a portion of the first plane and the second plane of the recess and the protrusion.

[0038] Aspect 23 of the present embodiment is a flow path member in which, in any of Aspects 18 to 22 above, the groove portions are formed on one side and the other side of the flow path member, and the groove portion formed on the one side and the groove portion formed on the other side are formed in positions facing each other.

[0039] Aspect 24 in this embodiment is a substrate used for manufacturing a flow path member having concave and convex portions arranged alternately in parallel and extending in a predetermined direction, the substrate comprising a base material having a first surface and a second surface located opposite the first surface, and a groove portion formed on the first surface and / or the second surface, the groove portion being formed at a position corresponding to at least a portion of the corners of the concave portions and the convex portions of the flow path member.

[0040] The flow path member 1 of this embodiment comprises a metal substrate 2 having a first surface 2A and a second surface 2B located on the opposite side of the first surface 2A, and a flow path portion 3 extending in a first direction D1 within the plane of the first surface 2A of the metal substrate 2.

[0041] The material constituting the metal base material 2 is not particularly limited, and may be, for example, a metal material such as austenitic stainless steel, titanium, aluminum, etc. On the surface (whole surface) of the metal base material 2 made of these materials, an electroplating layer, a vapor deposition layer, an electrodeposition layer, etc. (not shown) such as a gold layer, a silver layer, a nickel alloy layer, a carbon layer, a precious metal layer such as platinum, a resin layer containing a conductive material, etc. may be provided with a film thickness of about 5 nm to 30 nm. By providing the above-mentioned layer, the corrosion resistance of the flow path member 1 according to this embodiment can be improved, and the contact resistance with the gas diffusion layers 15, 16 of the fuel cell 10 (see FIG. 6) having the flow path member 1 can be further reduced.

[0042] The thickness T2 (see FIG. 3) of the metal substrate 2 may be set as appropriate according to the requirements and specifications for the thickness of a fuel cell 10 (see FIG. 6) having the flow path member 1 according to this embodiment, and may be, for example, approximately 0.05 mm to 1.00 mm.

[0043] The flow path section 3 provided on the first surface 2A of the metal base material 2 extends in a first direction D1 and has a plurality of grooves 31 arranged in parallel along a second direction D2 perpendicular to the first direction D1. The pitch P3 of the flow path section 3 (groove sections 31) in plan view from the first surface 2A side of the metal base material 2 is not particularly limited, but may be, for example, about 0.2 mm to 3.0 mm. The pitch P3 of the flow path section 3 (groove sections 31) is the length between the center of one groove section 31 in the second direction D2 (width direction) and the center of another groove section 31 adjacent thereto in the second direction D2 (width direction) in plan view from the first surface 2A side of the metal base material 2, and means the length parallel to the second direction D2 (width direction).

[0044] The metal base material 2 is formed with a supply manifold hole 4 for supplying a fluid to the flow path portion 3 and a discharge manifold hole 5 for discharging the fluid from the flow path portion 3. The supply manifold hole 4 is formed at one end of the metal base material 2 in the first direction D1, and the discharge manifold hole 5 is formed at the other end of the metal base material 2 in the first direction D1.

[0045] The supply manifold holes 4 include a fuel gas supply manifold hole 41, an oxidant gas supply manifold hole 42, and a coolant supply manifold hole 43. The exhaust manifold holes 5 include a fuel gas exhaust manifold hole 51, an oxidant gas exhaust manifold hole 52, and a coolant exhaust manifold hole 53. In this embodiment, the supply manifold holes 4 are arranged in parallel along the second direction D2 in the order of the oxidant supply manifold hole 42, the fuel gas supply manifold hole 41, and the coolant supply manifold hole 43, and the exhaust manifold holes 5 are arranged in parallel along the second direction D2 in the order of the coolant exhaust manifold hole 53, the fuel gas exhaust manifold hole 51, and the oxidant gas exhaust manifold hole 52, but the order of the manifold holes 41 to 43, 51 to 53 is not limited to this embodiment.

[0046] 1 is provided on the anode side of a fuel cell 10 (see FIG. 6). In the fuel cell 10, fuel gas is supplied to a flow path section 3 provided on a first surface 2A of the flow path member 1 through a fuel gas supply manifold hole 41 of the flow path member 1, and excess fuel gas is discharged through a fuel gas discharge manifold hole 51. In addition, a coolant is supplied to the second surface 2B side through a coolant supply manifold hole 43 of the flow path member 1, and the coolant is discharged through a coolant discharge manifold hole 53.

[0047] 2 is provided on the cathode side of a fuel cell 10 (see FIG. 6). In the fuel cell 10, an oxidant gas is supplied to a flow path section 3 provided on a first surface 2A of the flow path member 1 through an oxidant gas supply manifold hole 42 of the flow path member 1, and excess oxidant gas is discharged through an oxidant gas discharge manifold hole 52. A coolant is supplied to the second surface 2B side through a coolant supply manifold hole 43 of the flow path member 1, and the coolant is discharged through a coolant discharge manifold hole 53.

[0048] In a predetermined region 6 of the first surface 2A of the flow path member 1, a rough surface 61 (see FIG. 4A), a recess 62 (see FIG. 4B), a through hole portion 63 (see FIGS. 4C and 4D), a fine recess 64 (see FIG. 4E), etc. are formed by roughening the first surface 2A. In the flow path member 1 shown in FIG. 1, the rough surface 61 (see FIG. 4A), the recess 62 (see FIG. 4B), the through hole portion 63 (see FIGS. 4C and 4D), the fine recess 64 (see FIG. 4E), etc. are formed in a first region 6A that integrally surrounds the outer edges of the entirety of the plurality of flow path portions 3 provided on the first surface 2A and the fuel gas supply manifold hole 41 and the fuel gas exhaust manifold hole 51, and a second region 6B that surrounds the outer edges of the oxidant gas supply manifold hole 42, the coolant supply manifold hole 43, the oxidant gas exhaust manifold hole 52, and the coolant exhaust manifold hole 53. The first region 6A and the second region 6B are regions of the fuel cell 10 that come into contact with a gasket 19 (see FIGS. 6 and 7).

[0049] In the above region 6 (first region 6A and second region 6B), for example, one of a rough surface 61 (see FIG. 4A), a recess 62 (see FIG. 4B), a through hole portion 63 (see FIG. 4C and FIG. 4D), a fine recess 64 (see FIG. 4E), etc. may be formed, or two or more of them may be formed. For example, the rough surface 61 may be formed on at least a part of the surface of the recess 62 (see FIG. 4F), or the rough surface 61 may be formed on at least a part of the surface of the fine recess 64 or at least a part of the side surface portion 631 of the through hole portion 63 (see FIGS. 4G to 4I). In addition, the above region 6 may have a recess 62 and a through hole portion 63 formed.

[0050] By forming the rough surface 61 in the above-mentioned region 6 (first region 6A and second region 6B), an anchor effect can be generated between the gasket 19 (see Figs. 6 and 7), thereby improving the adhesion and bonding with the gasket 19. Furthermore, due to the anchor effect, even if the gasket 19 frequently contracts and expands as the fuel cell is repeatedly started and stopped, the fuel gas, oxidant gas, coolant, and other fluids supplied to the gas diffusion layers 15, 16 via the flow path section 3 can be effectively prevented from leaking from the fuel cell 10 (see Fig. 6).

[0051] By forming the recesses 62 in the region 6 (the first region 6A and the second region 6B), in addition to the effect of improving the adhesion and bonding with the gasket 19 due to the anchor effect, the gasket 19 can be made thicker, and vibration resistance can be improved. In addition, it is also possible to suppress the occurrence of positional deviation of the gasket 19 during the assembly work of the fuel cell 10 (see FIG. 6). Furthermore, when the supply manifold holes 4 and the discharge manifold holes 5 are formed by fine blanking on the workpiece substrate 20 in which the recesses 62 are formed in the region 6 (the first region 6A and the second region 6B), the fine blanking can be performed by fitting the protrusions of the plate holder into the recesses 62 in the second region 6B. Furthermore, by forming the recesses 62 in the region 6 (the first region 6A and the second region 6B), the flow path member 1 can be made lighter in weight.

[0052] By forming the through-holes 63 in the region 6 (the first region 6A and the second region 6B), the gasket 19 can be made thicker, and vibration resistance can be improved. In addition, it is also possible to suppress the occurrence of positional deviation of the gasket 19 during the assembly work of the fuel cell 10 (see FIG. 6). Furthermore, when the supply manifold holes 4 and the discharge manifold holes 5 are formed by fine blanking on the workpiece substrate 20 in which the through-holes 63 are formed in the region 6 (the first region 6A and the second region 6B), the fine blanking can be performed by fitting the protrusions of the plate holder into the through-holes 63 in the second region 6B. Furthermore, by forming the through-holes 63 in the region 6 (the first region 6A and the second region 6B), the flow path member 1 can be made lighter. In addition, the through-holes 63 can be used for positioning during the assembly work of the fuel cell 10.

[0053] By forming the fine recesses 64 in the region 6 (first region 6A and second region 6B), in addition to improving the adhesion and bonding with the gasket 19 due to the anchor effect, the gasket 19 can be made thicker and vibration resistance can be improved. Furthermore, by forming the fine recesses 64 in the region 6 (first region 6A and second region 6B), the flow path member 1 can be made lighter.

[0054] When the rough surface 61 (see FIG. 4A, etc.) is formed in the region 6 (first region 6A and second region 6B), the arithmetic mean roughness Ra of the rough surface 61 is in the range of 0.1 μm to 0.5 μm, and preferably in the range of 0.2 μm to 0.35 μm. If the arithmetic mean roughness Ra of the rough surface portion 61 is within the above range, the contact and adhesiveness with the gasket 19 (see FIGS. 6 and 7) can be improved, and leakage of fluid can be effectively prevented. In addition, if the arithmetic mean roughness Ra of the rough surface portion 61 exceeds 0.5 μm, fine gaps are formed between the rough surface portion 61 and the gasket 19, which may reduce the contact and adhesiveness with the gasket 19.

[0055] When a recess 62 (see FIG. 4B) is formed in the region 6, the opening dimension W 621 and the maximum depth D of the recess 62 62 The opening dimension W of the opening 621 of the recess 62 may be in the range of 1 / 4 to 1 / 2 of the thickness T2 of the metal base 2. 621 and the maximum depth D of the recess 62 62 If is within the above range, the adhesiveness and adhesion to the gasket 19 due to the anchor effect can be effectively improved, and the strength of the flow path member 1 can be maintained within a certain range.

[0056] When the through-hole portion 63 (see FIG. 4C and FIG. 4D) is formed in the region 6, the side portion 631 of the through-hole portion 63 may have a curved shape that is convex from the center of the width of the through-hole portion 63 toward the outside in a cross-sectional view along the thickness direction of the metal base material 2 (see FIG. 4C), or may have a protruding portion 632 that protrudes toward the center of the width of the through-hole portion 63 (see FIG. 4D). Note that the "curved shape that is convex from the center of the width of the through-hole portion 63 toward the outside" means that, assuming a straight line connecting the end portion on the first surface 2A side (the opening edge of the through-hole portion 63) of the side portion 631 and the end portion on the second surface 2B side (the opening edge of the through-hole portion 63), the entire side portion 631 is located outside the straight line (outside as viewed from the center of the width of the through-hole portion 63). The side portion 631 having the above shape can improve the adhesion and bonding between the through-hole portion 63 and the gasket 19 (see FIG. 6 and FIG. 7), thereby effectively preventing leakage of fluid. In the through-hole portion 63 shown in FIG. 4C, the opening dimension W 63A may be equal to or larger than the thickness T2 of the metal base 2. In the through-hole portion 63 shown in FIG. 4D, the opening dimension W 63A The opening dimension W of the opening 63A of the through-hole portion 63 shown in FIG. 63A The upper limit value can be appropriately set depending on the thickness T2 of the metal base 2.

[0057] In a cross-sectional view along the thickness direction of the metal base material 2, the length between the side surface portions 631 of the through-hole portion 63 on the first surface 2A (the opening dimension W 63A ) is defined as a first length L1, the maximum length between the side surface portions 631 of the through-hole portion 63 is defined as a second length L2, and the length between the side surface portions 631 of the through-hole portion 63 on the second surface 2B (the opening dimension W of the opening portion 63B of the through-hole portion 63 on the second surface 2B side is defined as 63B ) is the third length L3. The relationship between the first length L1, the second length L2, and the third length L3 may be such that the second length L2 is longer than the first length L1 and the third length L3 (see FIG. 4C), or the second length L2 may be the same as the first length L1 and the third length L3, and may have a portion between the side portions 631 that is shorter than the second length L2 (see FIG. 4D). In the case shown in FIG. 4C and FIG. 4D, the first length L1 may be substantially the same as the third length L3, may be longer than the third length L3, or may be shorter than the third length L3. The first length L1, the second length L2, and the third length L3 are lengths in a direction parallel to the first surface 2A and the second surface 2B in a cross-sectional view along the thickness direction of the metal base material 2. When the second length L2 is longer than the first length L1 and the third length L3 (see FIG. 4C), the second length L2 may be longer than the first length L1 and the third length L3 by about 0.01 mm to 0.10 mm. When the first length L1 is longer or shorter than the third length L3, the difference between the first length L1 and the third length L3 may be about 0.1 mm to 1.0 mm. The first length L1, the second length L2, and the third length L3 may be within a range of, for example, 0.05 mm to 1.05 mm.

[0058] When a fine recess 64 (see FIG. 4E) is formed in the region 6, the opening dimension W 641 and the maximum depth D of the fine recess 64 64 The opening dimension W of the opening 641 of the minute recess 64 may be greater than 0.00 mm and less than 1 / 4 of the thickness T2 of the metal base 2. 641 and the maximum depth D of the fine recess 64 64 If is within the above range, the adhesiveness and adhesion to the gasket 19 due to the anchor effect can be effectively improved, and the strength of the flow path member 1 can be maintained within a certain range.

[0059] A method for manufacturing the flow path member 1 having the above-mentioned configuration will be described. First, a substrate 20 to be processed is prepared, which is made of a metal material such as austenitic stainless steel, titanium, aluminum, etc., and has a first surface 20A and a second surface 20B located on the opposite side (see FIG. 5A). The substrate 20 to be processed may have the supply manifold holes 4 and the exhaust manifold holes 5 already formed therein, or may not have these formed therein. In the case of the latter substrate 20 to be processed, the supply manifold holes 4 and the exhaust manifold holes 5 may be formed after the flow path portion 3 is formed, as described below.

[0060] Then, a resist pattern 30 having an opening 30A at a position corresponding to the flow path portion 3 to be formed on the first surface 20A of the workpiece substrate 20 is formed (see FIG. 5B). The size of the opening 30A of the resist pattern 30 can be set appropriately according to the size of the flow path portion 3 of the flow path member 1. In this embodiment, the flow path portion 3 is formed by wet etching (half etching) using the resist pattern 30 as a mask, so the size of the opening 30A can be set smaller than the size of the flow path portion 3.

[0061] Next, the workpiece substrate 20 is subjected to a wet etching process using the resist pattern 30 as a mask to form a flow path portion 3 on the first surface 20A of the workpiece substrate 20, and then the resist pattern 30 is removed (see FIG. 5C). The method of the wet etching process is not particularly limited, and examples thereof include a spray etching method in which an etching solution is sprayed on the first surface 20A of the workpiece substrate 20, and a dipping method in which the workpiece substrate 20 is immersed in an etching solution.

[0062] When the supply manifold hole 4 and the exhaust manifold hole 5 are formed in the workpiece substrate 20 on which the flow path portion 3 is formed, a mask pattern 40 is formed having openings exposing a first formation planned region 60A that integrally surrounds the outer edges of the flow path portion 3, the fuel gas supply manifold hole 41, and the fuel gas exhaust manifold hole 51, and a second formation planned region 60B that surrounds the outer edges of the oxidant gas supply manifold hole 42, the coolant supply manifold hole 43, the oxidant gas exhaust manifold hole 52, and the coolant exhaust manifold hole 53 (see FIG. 5D). The first formation planned region 60A and the second formation planned region 60B are regions where the rough surface 61 (see FIG. 4A), the recessed portion 62 (see FIG. 4B), the through hole portion 63 (see FIG. 4C and FIG. 4D), the fine recessed portion 64 (see FIG. 4E), etc. are to be formed, and correspond to the first region 6A and the second region 6B of the flow path member 1 (see FIG. 1, etc.). Then, by performing a wet etching process on the workpiece substrate 20 via the mask pattern 40, a rough surface 61 (see FIG. 4A), a recess 62 (see FIG. 4B), a through-hole portion 63 (see FIG. 4C and FIG. 4D), a fine recess 64 (see FIG. 4E), etc. are formed in the first planned formation region 60A and the second planned formation region 60B, thereby manufacturing the flow path member 1 (see FIG. 5E).

[0063] On the other hand, when the supply manifold hole 4 and the exhaust manifold hole 5 are not formed in the workpiece substrate 20 in which the flow path portion 3 is formed, a mask pattern 40 is formed having openings exposing a first planned formation region 60A that integrally surrounds the outer edge of the region in which the flow path portion 3, the fuel gas supply manifold hole 41, and the fuel gas exhaust manifold hole 51 are to be formed, and a second planned formation region 60B that surrounds the outer edge of the region in which the oxidant gas supply manifold hole 42, the coolant supply manifold hole 43, the oxidant gas exhaust manifold hole 52, and the coolant exhaust manifold hole 53 are to be formed. The first planned formation region 60A and the second planned formation region 60B are regions in which the rough surface 61 (see FIG. 4A), the recessed portion 62 (see FIG. 4B), the through-hole portion 63 (see FIG. 4C and FIG. 4D), the fine recessed portion 64 (see FIG. 4E), etc. are to be formed, and correspond to the first region 6A and the second region 6B of the flow path member 1 (see FIG. 1, etc.). Then, wet etching is performed on the workpiece substrate 20 via the mask pattern 40 to form a rough surface 61 (see FIG. 4A), recesses 62 (see FIG. 4B), through-holes 63 (see FIGS. 4C and 4D), fine recesses 64 (see FIG. 4E), and the like in the first planned formation region 60A and the second planned formation region 60B. Thereafter, wet etching is performed using a pattern having openings corresponding to the supply manifold holes 4 and the exhaust manifold holes 5 as a mask to form the supply manifold holes 4 and the exhaust manifold holes 5, thereby manufacturing the flow path member 1 (see FIG. 1).

[0064] In the wet etching process for forming the rough surface 61 (see FIG. 4A), the recess 62 (see FIG. 4B), the through-hole portion 63 (see FIG. 4C and FIG. 4D), the fine recess 64 (see FIG. 4E), etc., the etching conditions (type of etching solution, temperature of the etching solution, etching time, etc.) may be set according to the type of the structure.

[0065] Next, a fuel cell 10 using the flow path member 1 according to this embodiment will be described. A fuel cell 10 in this embodiment includes a membrane electrode assembly 11 and flow path members 1 provided in contact with both sides of the membrane electrode assembly 11 (see FIG. 6). The fuel cell has a stack structure in which a plurality of fuel cells 10 are stacked.

[0066] The membrane electrode assembly 11 has a solid polymer electrolyte membrane 12, and catalyst layers 13, 14 and gas diffusion layers 15, 16 laminated in this order on both sides of the solid polymer electrolyte membrane 12. The catalyst layer 13 and gas diffusion layer 15 laminated on one side of the solid polymer electrolyte membrane 12 form a fuel electrode (hydrogen electrode) 17, and the catalyst layer 14 and gas diffusion layer 16 laminated on the other side form an air electrode (oxygen electrode) 18.

[0067] The solid polymer electrolyte membrane 12 is formed, for example, by applying a solution containing a hydrogen ion conductive polymer electrolyte onto a substrate and drying it. Examples of the hydrogen ion conductive polymer electrolyte membrane include perfluorosulfonic acid fluorine ion exchange resins, more specifically, perfluorocarbon sulfonic acid polymers (PFS polymers) in which the CH bonds of a hydrocarbon ion exchange membrane are replaced with fluorine. By introducing fluorine atoms with high electronegativity, the membrane becomes chemically stable, the degree of dissociation of sulfonic acid groups is high, and high ion conductivity can be achieved. Specific examples of such hydrogen ion conductive polymer electrolytes include "Nafion" (registered trademark) manufactured by DuPont, "Flemion" (registered trademark) manufactured by Asahi Glass Co., Ltd., "Aciplex" (registered trademark) manufactured by Asahi Kasei Corporation, and "Gore Select" (registered trademark) manufactured by Gore. The concentration of the hydrogen ion conductive polymer electrolyte contained in the hydrogen ion conductive polymer electrolyte-containing solution is usually about 5 to 60 mass%, and preferably about 20 to 40 mass%. The thickness of the solid polymer electrolyte membrane 12 is usually about 20 to 250 μm, preferably about 20 to 80 μm. In addition to the above-mentioned hydrogen ion conductive polymer electrolyte membrane, an anion conductive solid polymer electrolyte membrane or a liquid substance impregnated membrane can also be used. Examples of the anion conductive electrolyte membrane include hydrocarbon resins and fluorine resins. Specific examples of the hydrocarbon resins include Aciplex (registered trademark) A201, 211, and 221 manufactured by Asahi Kasei Corporation, and Neocepta (registered trademark) AM-1 and AHA manufactured by Tokuyama Corporation. Specific examples of the fluorine resins include Tosflex (registered trademark) IE-SF34 manufactured by Tosoh Corporation. Examples of the liquid substance impregnated membrane include polybenzimidazole (PBI).

[0068] The catalyst layers 13 and 14 are known platinum-containing catalyst layers (cathode catalyst layer 13 and anode catalyst layer 14). The catalyst layers 13 and 14 contain carbon particles carrying catalyst particles and a hydrogen ion conductive polymer electrolyte. Examples of the catalyst particles include platinum and platinum compounds. Examples of the platinum compounds include alloys of platinum and at least one metal selected from the group consisting of ruthenium, palladium, nickel, molybdenum, iridium, iron, and the like. Note that the catalyst particles contained in the cathode catalyst layer 13 are usually platinum, and the catalyst particles contained in the anode catalyst layer 14 are alloys of the above metal and platinum. In addition, the same material as that used in the solid polymer electrolyte membrane 12 described above can be used as the hydrogen ion conductive polymer electrolyte.

[0069] The gas diffusion layers 15 and 16 are well known and may be of various types used to form the fuel electrode 17 and the air electrode 18, and are made of a porous conductive base material to efficiently supply the fuel gas and the oxidant gas to the catalyst layers 13 and 14. Examples of the porous conductive base material include carbon paper and carbon cloth.

[0070] The flow path member 1 is provided so that the gasket 19 is superposed on the rough surface 61 (see FIG. 4A), the recessed portion 62 (see FIG. 4B), the through-hole portion 63 (see FIG. 4C and FIG. 4D), the fine recessed portion 64 (see FIG. 4E) and the like of the region 6 (first region 6A and second region 6B) of the first surface 2A of the metal base material 2, and is provided so that the first surface 2A of the metal base material 2 on which the gasket 19 is provided faces the gas diffusion layers 15, 16. A fuel gas (hydrogen) is supplied to the gas diffusion layer 15 through the flow path portion 3 of the flow path member 1 facing the gas diffusion layer 15 of the fuel electrode 17, and an oxidant gas (air or oxygen) is supplied to the gas diffusion layer 16 through the flow path portion 3 of the flow path member 1 facing the gas diffusion layer 16 of the air electrode 18.

[0071] In the fuel cell 10 of this embodiment, a rough surface 61 (see FIG. 4A), a recess 62 (see FIG. 4B), a through hole portion 63 (see FIG. 4C and FIG. 4D), a fine recess 64 (see FIG. 4E), and the like are formed on the first surface 2A of the metal base material 2 of the flow path member 1, and the gasket 19 is provided so as to overlap the rough surface 61 (see FIG. 4A), the recess 62 (see FIG. 4B), the through hole portion 63 (see FIG. 4C and FIG. 4D), the fine recess 64 (see FIG. 4E), and the like, thereby improving the adhesiveness and adhesion of the gasket 19 to the metal base material 2. Therefore, even if the operation and stop are frequently repeated during the operation of the fuel cell and the gasket 19 frequently contracts and expands due to heat generated by a chemical reaction, it is possible to effectively prevent the fuel gas, oxidant gas, coolant, and other fluids supplied to the gas diffusion layers 15 and 16 via the flow path portion 3 from leaking from the fuel cell 10.

[0072] The flow path member manufacturing substrate 100 according to this embodiment is formed by bending the flow path member manufacturing substrate 100, and is used to manufacture a fuel cell flow path member 200 (see FIGS. 15 to 20) having a plurality of recesses 201 and protrusions 202 arranged alternately in parallel along a first direction D1. As will be described later, the plurality of recesses 201 and protrusions 202 of the fuel cell flow path member 200 extend along a second direction D2 perpendicular to the first direction D1.

[0073] The flow path member manufacturing substrate 100 comprises a base material 101 having a first surface 101A and a second surface 101B located on the opposite side to the first surface 101A, and grooves 102 formed on the first surface 101A and / or the second surface 101B of the base material 101 (see FIGS. 8 to 13). The first surface 101A side of the flow path member manufacturing substrate 100 corresponds to one side 200A of a fuel cell flow path member 200 (see FIGS. 15 to 20) manufactured from the flow path member manufacturing substrate 100, and the second surface 101B side of the flow path member manufacturing substrate 100 corresponds to the other side 200B of the fuel cell flow path member 200.

[0074] The material constituting the base material 101 is not particularly limited, and may be, for example, a metal material such as austenitic stainless steel, titanium, or aluminum. On the surface (whole surface) of the base material 101 made of these materials, electroplating layers, vapor deposition layers, electrodeposition layers, etc. (not shown) such as a gold layer, a silver layer, a nickel alloy layer, a carbon layer, a precious metal layer such as platinum, or a resin layer containing a conductive material may be provided with a thickness of about 5 nm to 30 nm. By providing the above layers, the corrosion resistance of the fuel cell flow path member 200 (see FIGS. 15 to 20) manufactured from the flow path member manufacturing substrate 100 according to this embodiment can be improved, and the contact resistance with the gas diffusion layers 405, 406 of the fuel cell cell 400 (see FIG. 23) having the fuel cell flow path member 200 can be further reduced.

[0075] Thickness T of the substrate 101 101 may be appropriately set according to the requirements and specifications for the thickness of a fuel cell 400 (see FIG. 23) having a fuel cell flow path member 200 (see FIGS. 15 to 20) manufactured from the flow path member manufacturing substrate 100 according to this embodiment, and may be, for example, approximately 0.05 mm to 3.00 mm.

[0076] The grooves 102 are formed at positions corresponding to at least some of the corners of the recesses 201 and the protrusions 202 of the fuel cell flow path member 200 described below. By forming the grooves 102 in the base material 101, the fuel cell flow path member 200 manufactured from the flow path member manufacturing substrate 100 can be made lighter.

[0077] A corner of the recess 201 of the flow path member for a fuel cell 200 includes an inner side 211 located corresponding to the first surface 101A side of the base material 101 of the flow path member manufacturing substrate 100, and an outer side 212 located corresponding to the second surface 101B side of the base material 101 (see FIGS. 15 to 20). A corner of the protrusion 202 of the flow path member for a fuel cell 200 includes an outer side 222 located corresponding to the first surface 101A side of the base material 101, and an inner side 221 located corresponding to the second surface 101B side of the base material 101 (see FIGS. 15 to 20). The inner side 211 of the corner of the recess 201 is a corner formed by the first plane 213 and the first side wall surface 204 of the recess 201, and is a side where the angle between the first plane 213 and the first side wall surface 204 is less than 180° in a cross-sectional view of the flow path member manufacturing substrate 100. The outer side 212 of the corner of the recess 201 is a corner formed by the second plane 214 and the second side wall surface 205 of the recess 201, and is the side where the angle between the second plane 214 and the second side wall surface 205 is greater than 180° in the cross-sectional view of the flow path member production substrate 100. The inner side 221 of the corner of the protrusion 202 is a corner formed by the second plane 224 and the second side wall surface 205 of the protrusion 202, and is the side where the angle between the second plane 224 and the second side wall surface 205 is less than 180° in the cross-sectional view of the flow path member production substrate 100. The outer side 222 of the corner of the convex portion 202 is a corner formed by the first plane 223 and the first side wall surface 204 of the convex portion 202, and is the side where the angle between the first plane 223 and the first side wall surface 204 is larger than 180° in the cross-sectional view of the flow path member manufacturing substrate 100. In the flow path member manufacturing substrate 100 according to this embodiment, the groove portion 102 may be formed at a position corresponding to at least one of the outer side 212 and the inner side 211 of the corner of the recessed portion 201 and the outer side 222 and the inner side 221 of the corner of the convex portion 202. The groove portion 102 may be formed at a position corresponding to the first planes 213, 223 and the second planes 214, 224 of the recessed portion 201 and the convex portion 202 of the fuel cell flow path member 200, respectively, or may be formed at a position corresponding to the first side wall surface 204 and the second side wall surface 205.

[0078] For example, in the first embodiment of the flow path member manufacturing substrate 100 shown in Fig. 8, grooves 102 are formed on the first surface 101A of the base material 2, and the grooves 102 are formed at positions corresponding to the insides 211 of the corners of the recesses 201 in the fuel cell flow path member 200. As will be described later, each groove 102 in the flow path member manufacturing substrate 100 becomes a groove 203 formed on the insides 211 of the corners of the recesses 201 in the fuel cell flow path member 200 manufactured by pressing the flow path member manufacturing substrate 100 (see Fig. 15). It should be noted that the fuel cell flow path member 200 shown in FIG. 15 is manufactured by pressing the flow path member manufacturing substrate 100 shown in FIG. 8, and the number of grooves 102 in the flow path member manufacturing substrate 100 shown in FIG. 8 differs from the number of grooves 203 in the fuel cell flow path member 200 shown in FIG. 15. Needless to say, this is due to differences in the dimensional ratio of the scale between the flow path member manufacturing substrate 100 and the fuel cell flow path member 200 shown in each figure.

[0079] 9, grooves 102 are formed on the second surface 101B of the base material 101, and the grooves 102 are formed at positions corresponding to the insides 221 of the corners of the convex portions 202 of the fuel cell flow path member 200 and at positions corresponding to the second flat surfaces 214 of the concave portions 201. As will be described later, each groove 102 of the flow path member manufacturing substrate 100 becomes a groove 203 formed on the insides 221 of the corners of the convex portions 202 and on the second flat surfaces 214 of the concave portions 201 in the fuel cell flow path member 200 manufactured by pressing the flow path member manufacturing substrate 100 (see FIG. 16). It should be noted that the fuel cell flow path member 200 shown in FIG. 16 is manufactured by pressing the flow path member manufacturing substrate 100 shown in FIG. 9, and the number of grooves 102 in the flow path member manufacturing substrate 100 shown in FIG. 9 differs from the number of grooves 203 in the fuel cell flow path member 200 shown in FIG. 16. Needless to say, this is due to differences in the dimensional ratio of the scale between the flow path member manufacturing substrate 100 and the fuel cell flow path member 200 shown in each figure.

[0080] In the third embodiment of the flow path member manufacturing substrate 100 shown in FIG. 10, grooves 102 are formed on the first surface 101A and the second surface 101B of the base material 101, the grooves 102 on the first surface 101A are formed at positions corresponding to the insides 211 of the corners of the recesses 201 of the fuel cell flow path member 200, and the grooves 102 on the second surface 101B are formed at positions corresponding to the insides 221 of the corners of the protrusions 202 of the fuel cell flow path member 200. The grooves 102 on the first surface 101A and the grooves 102 on the second surface 101B are formed at positions that do not face each other. As will be described later, the grooves 102 on the flow path member manufacturing substrate 100 become grooves 203 formed on the insides 211 of the corners of the recesses 201 and the insides 221 of the corners of the protrusions 202 in the fuel cell flow path member 200 manufactured by pressing the flow path member manufacturing substrate 100 (see FIG. 17). It should be noted that the fuel cell flow path member 200 shown in FIG. 17 is manufactured by pressing the flow path member manufacturing substrate 100 shown in FIG. 10. The number of grooves 102 in the flow path member manufacturing substrate 100 shown in FIG. 10 differs from the number of grooves 203 in the fuel cell flow path member 200 shown in FIG. 17. Needless to say, this is due to differences in the dimensional ratio of the scale between the flow path member manufacturing substrate 100 and the fuel cell flow path member 200 shown in each figure.

[0081] In the fourth embodiment of the substrate 100 for manufacturing a flow path member shown in Figure 11, groove portions 102 are formed on the first surface 101A and the second surface 101B of the base material 101, and the groove portions 102 on the first surface 101A are formed at positions corresponding to the insides 211 of the corners of the recesses 201 and the outsides 222 of the corners of the convex portions 202 of the flow path member 200 for the fuel cell, and the groove portions 102 on the second surface 101B are formed at positions corresponding to the outsides 212 of the corners of the recesses 201 and the second plane 214 of the flow path member 200 for the fuel cell, and the insides 221 of the corners of the convex portions 202. The grooves 102 formed at positions corresponding to the inside 211 of the corners of the recesses 201 among the grooves 102 on the first surface 101A and the grooves 102 formed at positions corresponding to the outside 212 of the corners of the recesses 201 among the grooves 102 on the second surface 101B are formed at positions facing each other, and the grooves 102 formed at positions corresponding to the outside 222 of the corners of the protrusions 202 among the grooves 102 on the first surface 101A and the grooves 102 formed at positions corresponding to the inside 221 of the corners of the protrusions 202 are formed at positions facing each other. As will be described later, the grooves 102 of the flow path member manufacturing substrate 100 become grooves 203 formed on the inside 211 of the corners of the recesses 201, the outside 212 of the corners, and the second flat surface 214, and the outside 222 of the corners and the inside 221 of the corners of the protrusions 202 in the fuel cell flow path member 200 manufactured by pressing the flow path member manufacturing substrate 100 (see FIG. 18). In this embodiment, "formed at positions facing each other" means that when the grooves 102 of the second surface 101B are projected onto the first surface 101A, the grooves 102 of the first surface 101A and the grooves 102 of the second surface 101B projected onto the first surface 101A at least partially overlap in a plan view of the flow path member manufacturing substrate 100. The fuel cell flow path member 200 shown in Fig. 18 is manufactured by pressing the flow path member manufacturing substrate 100 shown in Fig. 11, and the number of grooves 102 of the flow path member manufacturing substrate 100 shown in Fig. 11 is different from the number of grooves 203 of the fuel cell flow path member 200 shown in Fig. 18, but this is due to differences in the dimensional ratio of the reduced scale between the flow path member manufacturing substrate 100 and the fuel cell flow path member 200 shown in each figure.

[0082] 12, grooves 102 are formed on the first surface 101A and the second surface 101B of the base material 101, and the grooves 102 on the first surface 101A are formed at positions corresponding to the inside 211 of the corner of the recess 201 of the fuel cell flow path member 200 and the first flat surface 213, the outside 222 of the corner of the protrusion 202 of the fuel cell flow path member 200 and the first flat surface 223, and the first side wall surface 204, and the grooves 102 on the second surface 101B are formed at positions corresponding to the outside 212 of the corner of the recess 201 of the fuel cell flow path member 200 and the second flat surface 214, the inside 221 of the corner of the protrusion 202 of the fuel cell flow path member 200 and the second flat surface 224, and the second side wall surface 205. The grooves 102 on the first surface 101A and the grooves 102 on the second surface 101B are formed at positions facing each other. As described later, each groove 102 of the flow path member manufacturing substrate 100 becomes grooves 203 formed on inner sides 211 and 212 of corners, first and second planes 213 and 214 of recesses 201, outer sides 222 and 221 of corners, first and second planes 223 and 224 of protrusions 202, and first and second side wall surfaces 204 and 205 of fuel cell flow path member 200 produced by pressing the flow path member manufacturing substrate 100 (see FIG. 19). Note that, in this embodiment, "formed at positions facing each other" means that when grooves 102 of second surface 101B are projected onto first surface 101A, grooves 102 of first surface 101A and grooves 102 of second surface 101B projected onto first surface 101A at least partially overlap each other in a plan view of the flow path member manufacturing substrate 100. 12. The number of grooves 102 in the flow path member manufacturing substrate 100 shown in FIG. 12 is different from the number of grooves 203 in the fuel cell flow path member 200 shown in FIG. 19. This is due to differences in the dimensional ratio of the scale between the flow path member manufacturing substrate 100 and the fuel cell flow path member 200 shown in each figure.

[0083] Opening width W of groove portion 102 102 (the length of the opening of the groove 102 on the first surface 101A and / or the second surface 101B parallel to the first direction D1) is not particularly limited, but is preferably the thickness T of the base material 101 101The depth (maximum depth) of the groove 102 is not particularly limited, and may be set appropriately depending on the width of the recess 201 and the protrusion 202 of the fuel cell flow path member 200, the height difference between the recess 201 and the protrusion 202, and the like. 101 The opening width W of the groove 102 on the first surface 101A may be about half of the width W 102 and the opening width W of the groove portion 102 of the second surface 101B 102 The opening width W of the groove 102 on the first surface 101A may be the same or different. 102 and the opening width W of the groove portion 102 of the second surface 101B 102 and are formed at positions facing each other, when groove portion 102 of second surface 101B is projected onto first surface 101A, groove portion 102 of first surface 101A may be physically contained in groove portion 102 of second surface 101B projected onto first surface 101A in a plan view of flow path member production substrate 100, or groove portion 102 of second surface 101B projected onto first surface 101A may be physically contained in groove portion 102 of first surface 101A. Also, the shape (cross-sectional shape) of groove portion 102 in flow path member production substrate 100 shown in FIGS. 8 to 12 has an opening width W 102 However, the groove 102 may have a shape in which the maximum width is greater than the opening width 3. Groove 102 having such a shape can further improve the water retention in the fuel cell 400 (see FIG. 23), and can relatively increase the contact area with the refrigerant, thereby manufacturing a fuel cell flow path member 200 that can improve the cooling efficiency by the refrigerant.

[0084] According to the flow path member manufacturing substrate 100 having the above configuration, the grooves 102 are formed on the first surface 101A and / or the second surface 101B of the base material 101, so that it is possible to manufacture a fuel cell flow path member 200 that is lightweight and has improved water retention and / or cooling efficiency. The fuel cell flow path member 200 is manufactured by pressing the flow path member manufacturing substrate 100 according to this embodiment, but generally, a "bending bump" may be formed at a corner (convex corner) due to the pressing (bending) of a metal thin plate. When this bending bump is formed, it becomes difficult for the first plane 223 of the convex portion 202 of the fuel cell flow path member 200 to come into contact with the gas diffusion layers 405, 406, and there is a risk of increasing the contact resistance. In this regard, by forming grooves 102 at positions corresponding to outer sides 212 of corners of recesses 201 and outer sides 222 of corners of protrusions 202 of fuel cell flow path member 200, it is possible to prevent bending bumps from being generated at outer sides 212, 222 of the corners in fuel cell flow path member 200 manufactured by pressing flow path member manufacturing substrate 100. Furthermore, in flow path member manufacturing substrate 100 shown in Figures 8 to 11, grooves 203 are reliably formed at corners of recesses 201 and / or protrusions 202 of fuel cell flow path member 200 manufactured therefrom, so high accuracy is required for alignment (positioning) of flow path member manufacturing substrate 100 during press working, but in flow path member manufacturing substrate 100 shown in Figure 12, alignment (positioning) accuracy of flow path member manufacturing substrate 100 during press working may be relatively low.

[0085] In the flow path member manufacturing substrate 100 according to the present embodiment described above, the grooves 102 are provided extending in the second direction D2 in correspondence with the corners of the recesses 201 and / or protrusions 202 of the fuel cell flow path member 200 manufactured by press working, but are not limited to this. For example, the grooves 102 may be provided at positions corresponding to the corners of the recesses 201 and / or protrusions 202 such that they are partially cut in the direction in which the grooves 102 extend (second direction D2) (see FIGS. 13 and 20).

[0086] A method for manufacturing the flow path member production substrate 100 having the above configuration will be described. In the following description, the method for manufacturing the flow path member production substrate 100 of the first embodiment (see FIG. 8) will be taken as an example, but the flow path member production substrates 100 of other embodiments shown in FIGS. 9 to 13 can also be manufactured by similar steps.

[0087] First, a substrate 101' to be processed made of a metal material such as austenitic stainless steel, titanium, or aluminum is prepared (see FIG. 14A), and a resist pattern 104B having an opening 104A at a position corresponding to the groove 102 to be formed in the substrate 101' to be processed is formed on a first surface 101A' and a second surface 101B' of the substrate 101' to be processed (see FIG. 14B). The size of the opening 104A in the resist pattern 104B can be appropriately set according to the size of the groove 102 of the flow path member manufacturing substrate 100. In this embodiment, the groove 102 is formed by wet etching (half etching) using the resist pattern 104B as a mask, so that the size of the opening 104A can be set smaller than the size of the groove 102.

[0088] Next, the substrate 101' is wet-etched using the resist pattern 104B as a mask to form the grooves 102 on the first surface 101A' of the substrate 101' (see FIG. 14C). The method of the wet etching is not particularly limited, and examples thereof include a spray etching method in which an etching solution is sprayed on the first surface 101A' of the substrate 101', and a dipping method in which the substrate 101' is immersed in an etching solution. By removing the resist pattern 104B from the substrate 101' in which the grooves 102 have been formed in this manner, the flow path member manufacturing substrate 100 according to this embodiment can be manufactured (see FIG. 14D).

[0089] As described above, in this embodiment, the grooves 102 are formed by wet etching the substrate 101', but this is not limited to this method. For example, the grooves 102, such as V-shaped grooves, may be formed by pressing the substrate 101'.

[0090] A fuel cell flow path member 200 in this embodiment will be described. The fuel cell flow path member 200 in this embodiment is manufactured by pressing the flow path member manufacturing substrate 100 according to this embodiment, and has a plurality of concave portions 201 and convex portions 202 arranged alternately in parallel (see Figs. 15 to 20). In this embodiment, the concave portions 201 are portions that are recessed downward when one side 200A of the fuel cell flow path member 200 is positioned upward and the other side 200B is positioned downward, and the convex portions 202 are portions that protrude upward in this state. The plurality of concave portions 201 and convex portions 202 are arranged alternately in parallel along a first direction D1, and extend along a second direction D2 perpendicular to the first direction D1. In this embodiment, one side 200A of the fuel cell flow path member 200 (the upper side of the fuel cell flow path member 200 in Figs. 15-19) faces, and preferably contacts, the gas diffusion layers 405, 406 in the fuel cell 400, and the other side 200B (the lower side of the fuel cell flow path member 200 in Figs. 15-19) is the side that contacts the coolant in the fuel cell 400. The recesses 201 function as flow paths for the reactant gas supplied to the gas diffusion layers 405, 406.

[0091] Pitch P of the recesses 201 and the protrusions 202 201 ,P 202 The pitch P of the recesses 201 is not particularly limited and may be, for example, about 0.2 mm to 3.0 mm. 201 By relatively increasing the pitch P of the protrusions 202, the amount of reactant gas supplied to the gas diffusion layers 405 and 406 can be relatively increased. 202 By making the pitch P of the recesses 201 and the protrusions 202 relatively large, the contact area between the fuel cell flow path member 200 and the gas diffusion layers 405, 406 can be relatively increased, and the contact resistance can be reduced. 201 ,P 202means the length between the center of one recess 201 and protrusion 202 in the first direction D1 (width direction) and the center of another recess 201 and protrusion 202 adjacent thereto in the first direction D1 (width direction) in a plan view of the fuel cell flow path member 200, and means the length parallel to the first direction D1 (width direction). 200 is not particularly limited, and may be, for example, about 0.05 mm to 1.00 mm. 200 means the length between the second plane 214 of the recess 201 and the first plane 223 of the protrusion 202, and is parallel to the third direction D3 (a direction perpendicular to the first direction D1 and the second direction D2).

[0092] The recess 201 and the protrusion 202 have a corner including inner sides 211, 221 and outer sides 212, 222, first flat surfaces 213, 223, second flat surfaces 214, 224 located opposite the first flat surfaces 213, 223, a groove 203, a first side wall surface 204, and a second side wall surface 205. An inner side 211 of the corner of the recess 201 is located corresponding to the first surface 101A side of the base material 101 of the flow path member production substrate 100, and an outer side 212 of the corner is located corresponding to the second surface 101B side of the base material 101 of the flow path member production substrate 100. An inner side 221 of a corner of convex portion 202 is located corresponding to the second surface 101B side of base material 101 of flow path member manufacturing substrate 100, and an outer side 222 of the corner is located corresponding to the first surface 101A side of base material 101 of flow path member manufacturing substrate 100. First flat surfaces 213, 223 and first side wall surface 204 are located corresponding to the first surface 101A side of base material 101 of flow path member manufacturing substrate 100, and second flat surfaces 214, 224 and second side wall surface 205 are located corresponding to the second surface 101B side of base material 101 of flow path member manufacturing substrate 100.

[0093] The fuel cell flow path member 200 in this embodiment has grooves 203 formed in at least some of the corners including the recesses 201 and the protrusions 202. The grooves 203 may be formed in at least some of the first flat surfaces 213, 223, the second flat surfaces 214, 224, the first side wall surface 204, and the second side wall surface 205, in addition to the corners.

[0094] For example, as shown in Fig. 15, a fuel cell flow path member 200 manufactured from the flow path member manufacturing substrate 100 shown in Fig. 8 has grooves 203 located on the insides 211 of the corners of the recesses 201. Also, as shown in Fig. 16, a fuel cell flow path member 200 manufactured from the flow path member manufacturing substrate 100 shown in Fig. 9 has grooves 203 located on the insides 221 of the corners of the protrusions 202 and on the second flat surface 214 of the recesses 201. Furthermore, as shown in Fig. 17, a fuel cell flow path member 200 manufactured from the flow path member manufacturing substrate 100 shown in Fig. 10 has grooves 203 located on the insides 211 of the corners of the recesses 201 and on the insides 221 of the corners of the protrusions 202.

[0095] As shown in FIG. 18, the fuel cell flow path member 200 manufactured from the flow path member manufacturing substrate 100 shown in FIG. 11 has grooves 203 located on the inner side 211 of the corner of the recess 201, the outer side 212 of the corner, and the second flat surface 214, and on the outer side 222 of the corner of the protrusion 202 and the inner side 221 of the corner. The grooves 203 on one side 200A and a part of the grooves 203 on the other side 200B of this fuel cell flow path member 200 may be formed in positions facing each other. For example, the grooves 203 located on the inner side 211 of the corner of the recess 201 and the grooves 203 located on the outer side 212 of the corner of the recess 201 are formed in positions facing each other. In addition, the grooves 203 located on the inner side 221 of the corner of the protrusion 202 and the grooves 203 located on the outer side 222 of the corner of the protrusion 202 are formed in positions facing each other. In this embodiment, "formed in a position facing each other" means that when groove portion 203 on the other side 200B is projected onto one side 200A, groove portion 203 on one side 200A and groove portion 203 of the other side 200B projected onto one side 200A at least partially overlap with each other.

[0096] As shown in Fig. 19, the fuel cell flow path member 200 manufactured from the flow path member manufacturing substrate 100 shown in Fig. 12 has grooves 203 located on the inner side 211 of the corner of the recess 201, the outer side 212 of the corner, the first flat surface 213, and the second flat surface 214, the outer side 222 of the corner of the protrusion 202, the inner side 221 of the corner, the first flat surface 223, and the second flat surface 224, and the first side wall surface 204 and the second side wall surface 205. A part of the grooves 203 on one side 200A of the fuel cell flow path member 200 and a part of the grooves 203 on the other side 200B may be formed in positions facing each other. For example, the grooves 203 located on the inner side 211 of the corner of the recess 201 and the grooves 203 located on the outer side 212 of the corner of the recess 201 are formed in positions facing each other. Moreover, the groove 203 located on the inside 221 of the corner of the convex portion 202 and the groove 203 located on the outside 222 of the corner of the convex portion 202 are formed in positions facing each other. Furthermore, a part of the groove 203 formed on each of the first plane 213 and the second plane 214 of the recess 201 and a part of the groove 203 formed on each of the first plane 223 and the second plane 224 of the convex portion 202 are formed in positions facing each other. Furthermore, a part of the groove 203 formed on each of the first side wall surface 204 and the second side wall surface 205 are formed in positions facing each other. In this embodiment, "formed in positions facing each other" means that when the groove 203 on the other side 200B is projected onto the one side 200A, the groove 203 on the one side 200A and the groove 203 on the other side 200B projected onto the one side 200A may at least partially overlap.

[0097] In this embodiment, the fuel cell flow path member 200 is manufactured by pressing the flow path member manufacturing substrate 100. Therefore, the opening width W 203 is the opening width W of the groove portion 102 in the flow path member manufacturing substrate 100 102 On the other hand, the opening width W 203 is the opening width W of the groove portion 102 in the flow path member manufacturing substrate 100 102The opening width W of the groove 203 located on the inside 211, 221 of the corner is longer than the opening width W 203 The opening width W of the groove portion 102 in the flow path member manufacturing substrate 100 102 Since the opening width W of the groove 203 located on the outer side 212, 222 of the corner portion is shorter than the width W of the groove 203, the flow rate of the fluid (e.g., air, hydrogen, refrigerant, etc.) flowing through the recess 201 can be increased in a fuel cell 400 (see FIG. 23) using the fuel cell flow path member 200, and the contact area between the fuel cell flow path member 200 and the fluid can be increased, thereby improving the water retention and cooling efficiency of the fuel cell 400. 203 The opening width W of the groove portion 102 in the flow path member manufacturing substrate 100 102 By making the width W longer than the width W1, it is possible to increase the area in which bending bumps are prevented from occurring on the outer sides 212, 222 of the corners during press working in manufacturing the fuel cell flow path member 200 from the flow path member manufacturing substrate 100. Note that the opening width W 203 is the opening width W of the groove portion 102 in the flow path member manufacturing substrate 100 102 The shape of the groove 203 of the fuel cell flow path member 200 is the same as the opening width W 203 The maximum width W max (See FIG. 21A.) When the grooves 203 have such a shape, the water retention can be further improved in the fuel cell 400 using the fuel cell flow path member 200.

[0098] As described above, the fuel cell flow path member 200 in this embodiment has the grooves 203, so that the fuel cell flow path member 200 can be made lighter. In addition, the fuel cell flow path member 200 has the grooves 203 corresponding to the grooves 102 formed on the first surface 101A of the base material 101 of the flow path member manufacturing substrate 100, i.e., the grooves 203 located on the gas diffusion layer 405, 406 side of the fuel cell 400 (see Fig. 15, Figs. 17 to 19), so that water generated in the fuel cell 400 is held in the grooves 203, and thus the water retention can be improved. In addition, the fuel cell flow path member 200 has the grooves 203 corresponding to the grooves 102 formed on the second surface 101B of the base material 101 of the flow path member manufacturing substrate 100, i.e., the grooves 203 located on the side of the fuel cell 400 that comes into contact with the refrigerant (see Figs. 16 to 19), so that the contact area of ​​the refrigerant with the fuel cell flow path member 200 can be relatively increased, and thus the cooling efficiency by the refrigerant can be improved. Furthermore, since the fuel cell flow path member 200 has the grooves 203 located on the outer sides 212 of the corners of the recesses 201 and the outer sides 222 of the corners of the protrusions 202 (see Figs. 18 and 19), it is possible to reduce the occurrence of bumps and burrs during bending (pressing), thereby reducing the contact resistance between the fuel cell flow path member 200 and other members (e.g., gas diffusion layers 405, 406). Furthermore, since the fuel cell flow path member 200 has the grooves 203 located on the first flat surfaces 213, 223 and the first side wall surface 204 (see Fig. 19), it is possible to easily cause turbulence in the fluid (e.g., reactant gas supplied to the gas diffusion layers 405, 406 and generated water in the fuel cell 400) flowing through the recesses 201 of the fuel cell flow path member 200, and therefore it is possible to promote the circulation of the fluid.

[0099] The fuel cell flow path member 200 having the above-mentioned configuration is manufactured by preparing a flow path member manufacturing substrate 100 according to this embodiment and a mold 300 (upper mold 301 and lower mold 302) for manufacturing the fuel cell flow path member 200 (see FIG. 22A), inserting the flow path member manufacturing substrate 100 between the upper mold 301 and the lower mold 302, and pressing from above and below (see FIG. 22B).

[0100] Next, a fuel cell 400 using the fuel cell flow path member 200 of this embodiment will be described. The fuel cell 400 in this embodiment includes a membrane electrode assembly 401 and a fuel cell flow path member 200 provided in contact with both sides of the membrane electrode assembly 401 (see FIG. 23). The fuel cell has a stack structure in which a plurality of fuel cell units 400 are stacked. In this embodiment, the fuel cell flow path member 200 is provided with one side 200A facing the membrane electrode assembly 401, preferably in contact with the membrane electrode assembly 401.

[0101] The membrane electrode assembly 401 has a solid polymer electrolyte membrane 402, and catalyst layers 403, 404 and gas diffusion layers 405, 406 laminated in this order on both sides of the solid polymer electrolyte membrane 402. The catalyst layer 403 and gas diffusion layer 405 laminated on one side of the solid polymer electrolyte membrane 402 constitute a fuel electrode (hydrogen electrode) 407, and the catalyst layer 404 and gas diffusion layer 406 laminated on the other side constitute an air electrode (oxygen electrode) 408.

[0102] The solid polymer electrolyte membrane 402 is formed, for example, by applying a solution containing a proton-conductive polymer electrolyte onto a substrate and drying it. Examples of the proton-conductive polymer electrolyte membrane include perfluorosulfonic acid-based fluorine ion exchange resins, more specifically, perfluorocarbon sulfonic acid-based polymers (PFS-based polymers) in which the CH bonds of a hydrocarbon-based ion exchange membrane are replaced with fluorine. By introducing fluorine atoms with high electronegativity, the membrane becomes chemically stable, the degree of dissociation of sulfonic acid groups is high, and high ion conductivity can be achieved. Specific examples of such proton-conductive polymer electrolytes include "Nafion" (registered trademark) manufactured by DuPont, "Flemion" (registered trademark) manufactured by Asahi Glass Co., Ltd., "Aciplex" (registered trademark) manufactured by Asahi Kasei Corporation, and "Gore Select" (registered trademark) manufactured by Gore. The concentration of the proton-conductive polymer electrolyte contained in the proton-conductive polymer electrolyte-containing solution is usually about 5 to 60 mass%, and preferably about 20 to 40 mass%. The thickness of the solid polymer electrolyte membrane 22 is usually about 20 to 250 μm, preferably about 20 to 80 μm. In addition to the above-mentioned hydrogen ion conductive polymer electrolyte membrane, an anion conductive solid polymer electrolyte membrane or a liquid substance impregnated membrane can also be used. Examples of the anion conductive electrolyte membrane include hydrocarbon resins and fluorine resins. Specific examples of the hydrocarbon resins include Aciplex (registered trademark) A201, 211, and 221 manufactured by Asahi Kasei Corporation, and Neocepta (registered trademark) AM-1 and AHA manufactured by Tokuyama Corporation. Specific examples of the fluorine resins include Tosflex (registered trademark) IE-SF34 manufactured by Tosoh Corporation. Examples of the liquid substance impregnated membrane include polybenzimidazole (PBI).

[0103] The catalyst layers 403 and 404 are known platinum-containing catalyst layers (cathode catalyst layer 403 and anode catalyst layer 404). The catalyst layers 403 and 404 contain carbon particles carrying catalyst particles and a hydrogen ion conductive polymer electrolyte. Examples of the catalyst particles include platinum and platinum compounds. Examples of the platinum compounds include alloys of platinum and at least one metal selected from the group consisting of ruthenium, palladium, nickel, molybdenum, iridium, iron, and the like. Note that the catalyst particles contained in the cathode catalyst layer 403 are usually platinum, and the catalyst particles contained in the anode catalyst layer 404 are alloys of the above metal and platinum. In addition, the same material as that used in the solid polymer electrolyte membrane 402 described above can be used as the hydrogen ion conductive polymer electrolyte.

[0104] Gas diffusion layers 405, 406 are well known, and various gas diffusion layers constituting fuel electrode 407 and air electrode 408 can be used, and are made of a porous conductive base material to efficiently supply fuel gas and oxidant gas to catalyst layers 403, 404. Examples of porous conductive base materials include carbon paper and carbon cloth.

[0105] The fuel cell flow path member 200 is provided such that the first plane 223 of the protrusion 202 faces, and preferably abuts, the gas diffusion layers 405, 406. A fuel gas (hydrogen) is supplied to the gas diffusion layer 405 through the recess 201 of the fuel cell flow path member 200 that abuts against the gas diffusion layer 405 of the fuel electrode 407, and an oxidant gas (air or oxygen) is supplied to the gas diffusion layer 406 through the recess 201 of the fuel cell flow path member 200 that abuts against the gas diffusion layer 406 of the air electrode 408.

[0106] In the fuel cell 400 having the above-mentioned configuration, when the fuel cell flow path member 200 has the grooves 203 located on the gas diffusion layers 405, 406 side (see Fig. 15, Figs. 17 to 19), the water generated in the fuel cell 400 is held in the grooves 203, so that the water retention can be improved. Furthermore, when the fuel cell flow path member 200 has the grooves 203 located on the side in contact with the refrigerant (cooling side) (see Figs. 16 to 19), the contact area of ​​the refrigerant with the fuel cell flow path member 200 can be relatively increased, so that the cooling efficiency by the refrigerant can be improved. Furthermore, when the fuel cell flow path member 200 has the grooves 203 located on the outer side 212 of the corners of the recessed portion 201 or the outer side 222 of the corners of the protruding portion 202 (see Figs. 18 and 19), the occurrence of bumps and burrs during bending (pressing) is reduced, so that the contact resistance between the fuel cell flow path member 200 and other members such as the gas diffusion layers 405, 406 is reduced. Furthermore, when the fuel cell flow path member 200 has groove portions 203 located on the first planes 213, 223 and the first side wall surface 204 (see FIG. 19), turbulence is more likely to be caused in the fluid (e.g., reactant gas supplied to the gas diffusion layers 405, 406 or generated water in the fuel cell 400) flowing through the recess 201 of the fuel cell flow path member 200, thereby promoting circulation of the fluid.

[0107] The above-described embodiments are described for the purpose of facilitating understanding of the present invention, and are not described for the purpose of limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design modifications and equivalents that fall within the technical scope of the present invention. [Explanation of symbols]

[0108] 1...Flow path member 2...Metal base material 2A…Side 1 2B…Second side 3...Flow passage section 4…Supply manifold hole 41...Fuel gas supply manifold hole 42...Oxidant gas supply manifold hole 43... Refrigerant supply manifold hole 5...Exhaust manifold hole 51...Fuel gas exhaust manifold hole 52...Oxidant gas exhaust manifold hole 53... Refrigerant discharge manifold hole 6…Area 6A…First area 6B…Second area 61…Rough surface 62…Recess 63...Through hole section 64...Fine recess 10...Fuel cell 100...Substrate for manufacturing flow path components 101...Base material 101A…Side 1 101B…Second side 102...Groove 200...Fuel cell flow path member 400…Fuel cell

Claims

1. A flow channel member formed by bending a substrate, having alternating recesses and protrusions extending in a predetermined direction, A groove is formed in at least a portion of the corners of the recess and the protrusion. The groove portion has a shape in which the maximum width within the groove portion is greater than the opening width of the groove portion, in the flow channel member.

2. The flow channel member according to claim 1, wherein the groove is formed in at least a portion of the inner side of the corner of the recess and the protrusion.

3. The flow channel member according to claim 1, wherein the groove is formed on at least a portion of the outer side of the corner of the recess and the protrusion.

4. The flow channel member according to claim 1, wherein the groove is formed in at least a portion of the inner side of the corner of the recess and the protrusion and at least a portion of the outer side of the corner.

5. The recess and the protrusion each include a first plane and a second plane located on the opposite side of the first plane. The flow channel member according to any one of claims 1 to 4, wherein the groove is formed in at least a portion of the first plane and the second plane of the recess and the protrusion.

6. The grooves are formed on one side and the other side of the flow channel member. The flow channel member according to any one of claims 1 to 4, wherein the groove formed on one side and the groove formed on the other side are formed in positions facing each other.

7. A substrate used to manufacture a flow channel member having alternating recesses and protrusions that extend in a predetermined direction, A substrate having a first surface and a second surface located opposite the first surface, The grooves formed on the first surface and / or the second surface Equipped with, The groove portion is formed at a position corresponding to at least a portion of the corner portion of the recess and the protrusion of the flow channel member, and is a substrate for manufacturing a flow channel member.

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