Separator and water electrolysis device

Abstract

To provide a separator capable of satisfactorily supplying and diffusing a fluid such as water and gas, and a water electrolysis device using the separator.SOLUTION: A separator 26 includes a plate-like separator body 27 having electrical conductivity, a fluid supply port 28A formed at one end of the separator body 27, a fluid discharge port 28B formed at the other end of the separator body 27, a flow path region 40 integrally formed with the separator body 27 between the fluid supply port 28A and the fluid discharge port 28B to allow fluid to pass through, a resistance large flow path part 42 formed at one end of the flow path adjacent to the fluid supply port 28A and the other end of the flow path adjacent to the fluid discharge port 28B in the flow path region 40 to increase the flow path resistance in a fluid supply direction X from the fluid supply port 28A, and a resistance small flow path part 44 formed at a position non-adjacent to the fluid supply port 28A and the fluid discharge port 28B in the flow path region 40 and in which the flow path resistance in the fluid supply direction X is smaller than that of the resistance large flow path part 42.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a separator and a water electrolysis device using the separator. [Background technology]

[0002] In recent years, water electrolysis devices that generate hydrogen and fuel cell devices that use hydrogen to generate electricity have been attracting attention as clean energy applications. By generating and storing hydrogen in a water electrolysis device using electricity obtained from renewable energy, and then using the hydrogen to generate electricity in a fuel cell as needed, it is possible to supply electricity continuously even when renewable energy is unstable.

[0003] For such water electrolysis devices and fuel cell devices, development is also being carried out on the cell stack configuration, and various technologies have been proposed for the cell structure including the electrolyte membrane, anode, cathode, and separator (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2020-136218 Summary of the Invention [Problem to be solved by the invention]

[0005] In such water electrolysis devices and fuel cell devices, separators are used to form flow paths for supplying and diffusing fluids such as water and gases. If the separator can efficiently supply and diffuse fluids such as water and gases, power generation efficiency and water electrolysis efficiency will improve, and therefore, improvements in separator flow paths are desired.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a separator that can satisfactorily supply and diffuse a fluid such as water or a gas, and a water electrolysis device using the separator. [Means for solving the problem]

[0007] The separator according to claim 1 comprises a conductive plate-shaped separator body, a fluid supply port formed at one end of the separator body so as to penetrate the separator body, a fluid discharge port formed at the other end of the separator member so as to penetrate the separator body, a flow path region formed integrally with the separator body between the fluid supply port and the fluid discharge port and allowing a fluid to pass, large resistance flow path sections formed in the flow path region at one end of the flow path adjacent to the fluid supply port and at the other end of the flow path adjacent to the fluid discharge port, and making the flow path resistance in the fluid supply direction from the fluid supply port greater than the flow path resistance in a direction perpendicular to the fluid supply port, and a position in the flow path region not adjacent to the fluid supply port and the fluid discharge port, and adjacent to the large resistance flow path portion in a direction perpendicular to the fluid supply direction. and a small resistance flow path portion formed in the fluid supply direction, the small resistance flow path portion having a flow path resistance in the fluid supply direction smaller than that of the large resistance flow path portion.

[0008] The separator according to claim 1 has a flow path region formed integrally with the separator body between the fluid supply port and the fluid discharge port, through which a fluid passes. The flow path region has a large-resistance flow path portion formed adjacent to the fluid supply port and the fluid discharge port, and a small-resistance flow path portion formed at a position not adjacent to the fluid supply port and the fluid discharge port. The large-resistance flow path portion has a flow path resistance greater in the fluid supply direction than in a direction perpendicular to the fluid supply direction. Therefore, fluids such as liquids and gases supplied from the fluid supply port are less likely to flow linearly to the fluid discharge port and more likely to flow to the small-resistance flow path portion. This prevents the fluid supplied from the fluid supply port from flowing linearly to the fluid discharge port, allowing the fluid to diffuse to portions of the separator far from the fluid supply port and fluid discharge port, thereby ensuring good fluid supply and diffusion.

[0009] In the separator according to claim 2, the large resistance flow path portion and the small resistance flow path portion are formed in an uneven pattern in which concaves on one side of the separator body become convex on the other side.

[0010] According to the separator of claim 2, the flow path can be easily formed in a relatively thin plate.

[0011] The separator according to claim 3 includes a supply header formed adjacent to the large resistance flow path section and the small resistance flow path section between the fluid supply port and the flow path region, for sending fluid to the flow path region, and a discharge header formed adjacent to the large resistance flow path section and the small resistance flow path section between the fluid discharge port and the flow path region, for discharging fluid from the flow path region.

[0012] According to the separator of claim 3, the fluid can be sent from the supply header to both the large resistance flow path section and the small resistance flow path section, and the fluid can be smoothly dispersed to areas not adjacent to the fluid supply port. In addition, the fluid can be smoothly discharged from the flow path area by the discharge header.

[0013] In the separator according to claim 4, the high resistance flow path portion and the low resistance flow path portion have, when viewed in the thickness direction, a reference portion, a first recess that is recessed on one side of the reference portion, and a second recess that is recessed on the other side of the reference portion, and the fluid supply port and the fluid discharge port are formed in the reference portion.

[0014] According to the separator of claim 4, the fluid supply port and the fluid discharge port can be easily connected to the recesses of the concave-convex pattern on both the one surface and the other surface of one separator.

[0015] In the separator according to claim 5, the supply header and the discharge header are formed flush with the reference portion when viewed in the thickness direction.

[0016] According to the separator of claim 5, the supply header and the discharge header can be easily formed.

[0017] In the separator according to claim 6, the large resistance flow path portion and the small resistance flow path portion are formed on both one and the other plate surfaces of the separator body.

[0018] According to the separator of claim 6, flow paths for flowing different fluids can be formed on one surface and the other surface of one separator.

[0019] In the separator according to claim 7, the large resistance flow path portion is formed in a concave shape extending in a direction intersecting the fluid supply direction, and the small resistance flow path portion is formed in a concave shape extending in a direction perpendicular to the extension direction of the large resistance flow path portion.

[0020] According to the separator of claim 7, by extending the recess in a direction intersecting the fluid supply direction, it is possible to easily make the fluid flow in a direction different from the fluid supply direction.

[0021] In the separator according to claim 8, the small resistance flow path portion is formed in a concave shape that is shorter in a direction intersecting the fluid supply direction than the large resistance flow path portion.

[0022] According to the separator of claim 8, by making the recess shorter than the large resistance flow path portion, it is possible to easily form a small resistance flow path portion having a smaller flow path resistance than the large resistance flow path portion.

[0023] A water electrolysis device according to a ninth aspect of the present invention includes the separator according to any one of the first to eighth aspects of the present invention.

[0024] According to the water electrolysis device of claim 9, the separator allows fluids such as water and gas to be supplied and diffused well, thereby improving the efficiency of water electrolysis. [Effects of the Invention]

[0025] The separator according to the present invention allows for good supply and diffusion of fluids such as water and gas. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 2 is a plan view of the anode side of the separator used in the water electrolysis apparatus according to the first embodiment. [Figure 2] 2 is a cross-sectional view of a cell of a portion of the water electrolysis device according to the first embodiment, taken along line 2-2 in FIG. 1. FIG. [Figure 3] 3 is a cross-sectional view of a portion of the water electrolysis apparatus according to the first embodiment, taken along line 3-3 in FIG. 1. FIG. [Figure 4] FIG. 4 is a partial plan view of a large resistance flow path portion. [Figure 5] FIG. 4 is a partial plan view of a small resistance flow path portion. [Figure 6] FIG. 4 is a partial plan view of a resistance intermediate flow passage portion. [Figure 7] 4, (B) is a cross-sectional view of the small resistance flow path portion taken along line BB in FIG. 5, and (C) is a cross-sectional view of the medium resistance flow path portion taken along line CC in FIG. 6. [Figure 8] 2 is a plan view of the cathode side of the separator used in the water electrolysis apparatus according to the first embodiment. FIG. [Figure 9] (A) is a cross-sectional view of a large resistance flow path portion, (B) is a cross-sectional view of a small resistance flow path portion, and (C) is a cross-sectional view of a medium resistance flow path portion. [Figure 10] FIG. 1A is an explanatory diagram showing the flow of water in a flow channel region of this embodiment, and FIG. 1B is an explanatory diagram showing the flow of water in a flow channel region of a comparative example. [Figure 11] FIG. 10 is a partial plan view of a small resistance flow path portion according to a modified example. [Figure 12] 3 is a cross-sectional view of a stack of a portion of the water electrolysis device according to the first embodiment, taken along line 3-3 in FIG. 1. FIG. [Figure 13] FIG. 6 is a plan view of the anode side of a separator used in a water electrolysis apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0027] First Embodiment A first embodiment of a water electrolysis device of the present invention will be described with reference to the drawings. In this embodiment, a polymer electrolyte membrane (PEM) water electrolysis apparatus 10A will be described as an example. Fig. 1 shows a plan view of a separator 26 of a cell 20 of the water electrolysis apparatus 10A, and Figs. 2 and 3 show partial schematic cross sections of the cell 20.

[0028] 2 and 3, the cell 20 includes an electrolyte layer 22, and an anode catalyst layer 24, an anode gas diffusion layer 25, and a separator 26 stacked in this order on one surface of the electrolyte layer 22. Also, a cathode catalyst layer 34, a cathode gas diffusion layer 35, and a separator 36 stacked in this order on the other surface of the electrolyte layer 22.

[0029] The electrolyte layer 22 has a rectangular shape and can be made of a carbon-fluorine-based polymer membrane or a carbon-fluorine-based polymer membrane. The anode catalyst layer 24 laminated on one surface of the electrolyte layer 22 covers the inner periphery of one surface of the electrolyte layer 22, which is narrower than the outer periphery, and can be made of an Ir-based catalyst or the like. The cathode catalyst layer 34 laminated on the other surface of the electrolyte layer 22 covers the inner periphery of the other surface of the electrolyte layer 22, which is narrower than the outer periphery, and can be made of a Pt / carbon-based catalyst or the like.

[0030] The anode gas diffusion layer 25 is laminated on the anode catalyst layer 24. The anode gas diffusion layer 25 has substantially the same shape as the anode catalyst layer 24 in a plan view. The anode gas diffusion layer 25 can be made of a material that allows fluid to flow through the layer, such as a porous body, a powder sintered body, a fiber sintered body, a metal mesh, or felt.

[0031] A separator 26 is laminated on the anode gas diffusion layer 25. Details of the separator 26 will be described later.

[0032] The cathode gas diffusion layer 35 is laminated on the cathode catalyst layer 34. The cathode gas diffusion layer 35 has substantially the same shape as the cathode catalyst layer 34 in a plan view. The cathode gas diffusion layer 35 can be made of a material that allows fluid to flow through the layer, such as a porous body, a powder sintered body, a fiber sintered body, a metal mesh, or felt.

[0033] A separator 36 is laminated on the cathode gas diffusion layer 35. The separator 36 will be described in detail later. A voltage is applied between the separator 26 and the separator 36 by a voltage application means 11.

[0034] 1, separator 26 is composed of a rectangular plate-shaped separator body 27, and fluid openings 28 and a flow path region 40 are formed in separator body 27. Note that FIG. 1 is a plan view seen from below the cross section of FIGS.

[0035] The fluid openings 28 are formed at each of the four corners of the separator body 27. When viewed from one side, one fluid opening 28 at one end serves as a fluid supply port 28A, and the fluid opening 28 at the other end diagonally opposite the one fluid supply port 28A serves as a fluid discharge port 28B. In plan view, the direction in which fluid is supplied from the fluid supply port 28A to the flow path region 40 is referred to as the fluid supply direction X. Here, the direction along the shortest distance from the fluid supply port 28A to the flow path region 40 is referred to as the fluid supply direction X. Opening seal members 56 are provided around the other two fluid openings 28 on the one side, sealing the gap between the separator body 27 and the electrolyte layer 22.

[0036] The flow path region 40 is a region through which a fluid passes. In plan view, the flow path region 40 is formed integrally with the separator 26 between the fluid supply port 28A and the fluid discharge port 28B and has a shape corresponding to the anode gas diffusion layer 25. The flow path region 40 is formed with a high-resistance flow path section 42, a low-resistance flow path section 44, and a medium-resistance flow path section 46.

[0037] 1, when the flow path region 40 is divided vertically and horizontally into four regions A1, B1, C1, and D1, the large resistance flow path section 42 is formed in one flow path end (region A1) adjacent to the fluid supply port 28A and the other flow path end (region D1) adjacent to the fluid discharge port 28B. As shown in Fig. 4, the large resistance flow path section 42 is formed in a plan view by alternately arranging elongated holes 42A elongated in the Y direction perpendicular to the fluid supply direction X and convex shapes 42B elongated in the same direction in the fluid supply direction X and Y directions. The large resistance flow path section 42 has high flow path resistance in the fluid supply direction X and low flow path resistance in the Y direction.

[0038] The small resistance flow path section 44 is formed in regions B1 and C1 in the flow path region 40, which are not adjacent to the fluid supply port 28A and the fluid discharge port 28B. As shown in Fig. 5, the small resistance flow path section 44 has a configuration obtained by rotating the large resistance flow path section 42 by 90° in a plan view, and is formed by alternately arranging elongated holes 44A in the fluid supply direction X and elongated convex shapes 44B in the fluid supply direction X and Y. The small resistance flow path section 44 has low flow path resistance in the fluid supply direction X and high flow path resistance in the Y direction.

[0039] The medium resistance flow path section 46 is disposed in the central portion of the flow path region 40. As shown in FIG. 6 , the medium resistance flow path section 46 is formed in a plan view by alternately arranging elongated holes 46A elongated in the Y direction perpendicular to the fluid supply direction X and convex shapes 46B elongated in the same direction in the fluid supply direction X and Y directions. The lengths of the elongated holes 46A and the convex shapes 46B in the fluid supply direction X are set shorter than the lengths of the elongated holes 42A and the convex shapes 42B in the same direction. The medium resistance flow path section 46 has medium flow path resistance in the fluid supply direction X and small flow path resistance in the Y direction.

[0040] The flow path resistance in the fluid supply direction X in the high resistance flow path section 42, the medium resistance flow path section 46, and the low resistance flow path section 44 is the highest in the high resistance flow path section 42 and the lowest in the low resistance flow path section 44, and the medium resistance flow path section 46 is smaller than the high resistance flow path section 42 and larger than the low resistance flow path section 44.

[0041] 7(A), (B), and (C), the large-resistance flow path section 42, the small-resistance flow path section 44, and the medium-resistance flow path section 46 are formed in a concave-convex pattern in which concaves on one side of the separator body 27 become convex on the other side when viewed in the thickness direction (cross-sectional view). The concave-convex pattern has a reference section α located in the center in the thickness direction, a first recessed section β that is concave on one side of the reference section α, and a second recessed section γ that is concave on the other side of the reference section α. ​​The first recessed section β and the second recessed section γ are set to the same depth.

[0042] As shown in FIG. 7(A), on one surface (the side facing the anode gas diffusion layer 25), the elongated holes 42A of the large-resistance flow path section 42 are formed with first recesses β, and a second recess γ and a reference portion α are formed between adjacent elongated holes 42A. On the other hand, on one surface, the elongated holes 44A of the small-resistance flow path section 44 are formed with first recesses β, and a second recess γ and a reference portion α are formed between adjacent elongated holes 44A. On the other surface, the elongated holes 46A of the medium-resistance flow path section 46 are formed with first recesses β, and a second recess γ and a reference portion α are formed between adjacent elongated holes 46A. The first recesses β and the second recesses γ have opposite concavities and convexities on one surface and the other surface. That is, the first recesses β are concave on one surface and convex on the other surface, and the second recesses γ are convex on one surface and concave on the other surface. Such a pattern with projections and depressions on both sides can be easily formed by double-sided pressing.

[0043] 1, on one side of the flow path region 40 of the separator body 27, a supply header 50 is formed in a portion other than the fluid openings 28, continuing from the large resistance flow path section 42 and the small resistance flow path section 44. The supply header 50 is formed as a flat surface that is flush with the reference portion α, as shown in FIG.

[0044] On the other side of the separator body 27 across the flow path region 40, a discharge header 52 is formed in the portion other than the fluid openings 28, continuing from the large resistance flow path section 42 and the small resistance flow path section 44. Similar to the supply header 50, the discharge header 52 is formed with a flat surface that is flush with the reference section α.

[0045] A peripheral seal layer 54 is formed on the peripheral portion of the separator body 27. As shown in Fig. 2, the peripheral seal layer 54 seals between the electrolyte layer 22 and the separator 26. As shown in Fig. 1, the peripheral seal layer 54 is connected to an opening seal member 56. The peripheral seal layer 54 and the opening seal member 56 can be made of a resin or rubber material.

[0046] 2, the separator body 27 is disposed so that the bottom of the second recess γ is in contact with the anode gas diffusion layer 25. A space is formed between the anode gas diffusion layer 25 and the first recess β and the reference portion α, which serves as a fluid passage.

[0047] The separator 26 is made of a conductive material, and a voltage is applied to it by the voltage application means 11 .

[0048] Separator 36 has the same shape as separator 26. In Figure 8, separator 36 is shown in a plan view from above the cross section of Figures 2 and 3. Separator 36 is made up of a separator body 37, and like separator 26, fluid openings 28 and a flow path region 40 are formed in separator body 37. Furthermore, flow path region 40 is formed with a large resistance flow path section 42, a small resistance flow path section 44, and a medium resistance flow path section 46.

[0049] Of the fluid openings 28, those provided in the discharge header 52 serve as cathode fluid discharge ports 28C on the cathode side. Opening seal members 56 are provided around the three fluid openings 28 other than the cathode fluid discharge port 28C on one side, sealing the gap between the separator body 37 and the electrolyte layer 22.

[0050] 9(A), on one surface, the elongated holes 42A of the large-resistance flow path section 42 are formed by the second recess γ, and a first recess β and a reference portion α are formed between adjacent elongated holes 42A. Also, on one surface, the elongated holes 44A of the small-resistance flow path section 44 are formed by the second recess γ, and a first recess β and a reference portion α are formed between adjacent elongated holes 44A. Also, on one surface, the elongated holes 46A of the medium-resistance flow path section 46 are formed by the second recess γ, and a first recess β and a reference portion α are formed between adjacent elongated holes 46A. That is, in the concavo-convex pattern, the other surface side of the separator 26 corresponds to one surface side of the separator 36.

[0051] 2, in the separator 36, the separator body 37 is disposed so that the bottom of the first recess β is in contact with the cathode gas diffusion layer 35. A space is formed between the cathode gas diffusion layer 35 and the second recess γ and the reference portion α, which serves as a fluid passage.

[0052] 8, a supply header 50 is formed with a flat surface that is flush with the reference portion α on one side of the flow path region 40 of the separator body 37. Furthermore, a discharge header 52 is formed with a flat surface that is flush with the reference portion α on the other side of the flow path region 40 of the separator body 27.

[0053] A peripheral seal layer 54 is formed on the peripheral portion of the separator body 27. As shown in Fig. 2, the peripheral seal layer 54 seals between the electrolyte layer 22 and the separator 26. The peripheral seal layer 54 is also connected to an opening seal member 56. The peripheral seal layer 54 and the opening seal member 56 can be made of a resin or rubber material.

[0054] The separator 36 is made of a conductive material, and a voltage is applied to it by the voltage application means 11 .

[0055] Next, the effects of this embodiment will be described.

[0056] Water supplied from fluid supply port 28A flows into supply header 50 and then flows from supply header 50 into flow path region 40. In flow path region 40, large-resistance flow path section 42 is provided in region A1 adjacent to fluid supply port 28A via supply header 50, so the inflow of water into region A1 is suppressed compared to when region A and region B have the same flow path resistance. On the other hand, small-resistance flow path section 44 is provided in region B1, which is not adjacent to fluid supply port 28A, so the inflow of water into region B1 is promoted. This suppresses the amount of water that flows linearly from fluid supply port 28A to fluid discharge port 28B, allowing the supplied water to be dispersed well in flow path region 40.

[0057] In the water electrolysis apparatus 10A, application of a voltage between the separator 26 and the separator 36 causes the following reaction (1) to occur on the surface of the anode catalyst layer 24.

[0058] H2O → 2H + + 0.5O2+ 2e - (1)

[0059] Oxygen O2 is diffused in the anode gas diffusion layer 25 and discharged to the fluid discharge port 28B together with unreacted water (H2O) described below.

[0060] Hydrogen ion H + moves to the cathode side through the electrolyte layer 22 and converts electrons e supplied by external wiring - (reaction (2)) to become hydrogen H2, which is diffused in the cathode gas diffusion layer 35, passes through the discharge header 52, and is discharged from the cathode fluid discharge port 28C.

[0061] 2H + + 2e - → H2(2)

[0062] Water that flows into regions A1 and B1 of flow path region 40 flows toward regions C1 and D1, respectively, in fluid supply direction X of flow path region 40, and a portion of the water passes through central medium-resistance flow path section 46. Water that had difficulty flowing in fluid supply direction X in region A1 becomes more flowable in region C1, and water that had difficulty flowing in fluid supply direction X in region B1 becomes more flowable in region D1. Furthermore, water flows with moderate fluid resistance in central medium-resistance flow path section 46, passes through regions C1 and D1, flows into discharge header 52, and is discharged to fluid discharge port 28B.

[0063] 10 shows the fluid flow (B) when all fluid resistances in the flow path region 40 are set to the same, and the fluid flow (A) when regions with different fluid resistances are provided as in this embodiment. When all fluid resistances in the flow path region 40 are set to the same, as shown in FIG. 10(B), a large amount of fluid flows linearly from the fluid supply port 28A to the fluid discharge port 28B. On the other hand, by providing regions with different fluid resistances as in this embodiment, the flow of fluid in the flow path region 40 is equalized, as shown in FIG. 10(A), and the fluid can be diffused throughout the entire flow path region 40.

[0064] Furthermore, in this embodiment, since the supply header 50 and the discharge header 52 are provided, the fluid can be sent from the supply header 50 to both the large resistance flow path section 42 and the small resistance flow path section 44, and water can be smoothly diffused to areas not adjacent to the fluid supply port 28A. In addition, the discharge header 52 allows water to be smoothly discharged from the flow path area 40.

[0065] In this embodiment, the large resistance flow path portion 42, the small resistance flow path portion 44, and the medium resistance flow path portion 46 are formed in an uneven pattern in which a concave shape on one side of the separator body 27, 37 becomes a convex shape on the other side. Therefore, flow paths can be easily formed in a relatively thin plate, and the thickness of the separators 26, 37 can be made thin.

[0066] In this embodiment, the reference portion α is formed with the fluid supply port 28A and the fluid discharge port 28B. Therefore, the fluid supply port 28A and the fluid discharge port 28B can be easily connected to the first recess β and the second recess γ on both the one surface and the other surface of one separator 26, 36.

[0067] In this embodiment, the supply header 50 and the discharge header 52 are formed flush with the reference portion α when viewed in the thickness direction, which makes it easy to form the supply header 50 and the discharge header 52.

[0068] In this embodiment, a flow path region 40 having a large resistance flow path portion 42, a small resistance flow path portion 44, and a medium resistance flow path portion 46 is formed on both one and the other plate surfaces of the separator bodies 27, 37. Therefore, flow paths for flowing different fluids can be formed on one and the other surfaces of a single separator 26, 36.

[0069] Furthermore, in this embodiment, the large resistance flow path section 42 is formed by an elongated hole extending in a direction perpendicular to the fluid supply direction X, and the small resistance flow path section 44 is formed by an elongated hole extending in a direction perpendicular to the extension direction of the elongated hole of the large resistance flow path section 42. Therefore, it is possible to easily make the fluid flow in a direction different from the fluid supply direction.

[0070] In this embodiment, the flow path resistance of the large-resistance flow path section 42 and the small-resistance flow path section 44 is made different by changing the elongated hole extension direction, but the flow path resistance may also be made different by changing the elongated hole extension length. For example, the flow path resistance can be reduced by making the elongated hole extension length of the small-resistance flow path section 44 shorter than that of the large-resistance flow path section 42. Furthermore, as shown in FIG. 11 , the flow path resistance can be reduced by using a circular concavo-convex pattern in a plan view.

[0071] 12, a plurality of cells 20 of this embodiment can be stacked to form a cell stack 20S. In this case, one surface of one separator 26 can be opposed to the anode gas diffusion layer 25, and the other surface can be opposed to the cathode gas diffusion layer 35, and can be used in the same manner as one surface of the separator 36.

[0072] Furthermore, by using the separator 26 of this embodiment in the water electrolysis apparatus 10A, one side can be used as the anode side for supplying water, and the other side can be used as the cathode side for recovering hydrogen gas. Therefore, even if the concave and convex surfaces of the separator 26 are reversed between one side and the other side, different fluids can be suitably passed through the front and back sides of a single separator 26.

[0073] Second Embodiment Next, a second embodiment of the present invention will be described. In this embodiment, the same parts as those in the first embodiment are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0074] The water electrolysis apparatus 10B of this embodiment differs from the first embodiment only in the planar shape of the separator, the pattern formed in the flow path region, and the arrangement of the fluid openings, but the other configurations are the same as those of the first embodiment.

[0075] 13, separator 66 of this embodiment has protrusions 66A and 66B protruding from one surface on the short sides of the rectangular plate in a plan view. Fluid supply port 28A is formed in protrusion 66A, and fluid discharge port 28B is formed in protrusion 66B. In the description of this embodiment, fluid openings other than fluid supply port 28A and fluid discharge port 28B are omitted.

[0076] A high-resistance flow path section 42 and a low-resistance flow path section 44 are formed in the flow path region 40. When the flow path region 40 is vertically divided into four sections, with one end section being region A2, the two middle sections being region B2, and the other end section being region C2, the high-resistance flow path section 42 is formed in one end section (region B2) of the flow path adjacent to the fluid supply port 28A and the fluid discharge port 28B. The low-resistance flow path section 44 is formed in the flow path region 40 in regions A2 and C2 that are not adjacent to the fluid supply port 28A and the fluid discharge port 28B.

[0077] On one side of the separator body 27 across the flow path region 40, a supply header 50 is formed in a portion other than the fluid openings 28, continuing with the large resistance flow path section 42 and the small resistance flow path section 44. On the other side of the separator body 27 across the flow path region 40, a discharge header 52 is formed in a portion other than the fluid openings 28, continuing with the large resistance flow path section 42 and the small resistance flow path section 44.

[0078] Even when the separator 66 of this embodiment is used, the fluid can flow through the entire flow path region 40 .

[0079] In the above-described embodiments, the water electrolysis apparatuses 10A and 10B are provided with the anode gas diffusion layer 25 and the cathode gas diffusion layer 35, but the anode gas diffusion layer 25 and the cathode gas diffusion layer 35 may be omitted.

[0080] Furthermore, in each of the above-described embodiments, the large resistance flow path section 42 and the small resistance flow path section 44 of the flow path region 40 of the separator 26, 36 are formed with an uneven pattern in which a concave shape on one side of the separator body 27, 37 becomes a convex shape on the other side, but a pattern in which unevenness is formed on only one side is also acceptable.

[0081] In addition, in each of the above-described embodiments, the supply header 50 and the discharge header 52 are formed on the separators 26, 36, but it is also possible to form the supply header 50 and the discharge header 52 by disposing separate sealing members in their regions.

[0082] In addition, in each of the above-described embodiments, the first recessed portion β and the second recessed portion γ of the separators 26, 36 are set to have the same depth, but the depths may be changed depending on the application. For example, in the separator 26 that constitutes the anode-side flow path of the water electrolysis device as in this embodiment, the first recessed portion β on one side can be made deeper than the second recessed portion γ on the other side. By setting the depths in this manner, it is possible to efficiently pass fluid between the front and back of the separator depending on the fluid flow rate.

[0083] Furthermore, in the above-described embodiments, a polymer electrolyte membrane (PEM) water electrolysis device has been described as an example, but the present invention can also be used in an anion exchange membrane (AEM) water electrolysis device. [Explanation of symbols]

[0084] 10A, 10B Water electrolysis device 26, 66 separator 27 Separator body 28A Fluid supply port 28B Fluid outlet 40 Flow Area 42 High resistance flow path section 44 Low resistance flow path section 50 Supply Header 52 Discharge Header α Reference part β First recess γ Second recess X Fluid supply direction

Claims

1. a conductive plate-shaped separator body; a fluid supply port formed at one end of the separator body so as to penetrate the separator body; a fluid outlet formed at the other end of the separator body by penetrating the separator body; a flow path region formed integrally with the separator body between the fluid supply port and the fluid discharge port, for allowing a fluid to pass therethrough; a large resistance flow path portion formed in the flow path region at one end of the flow path adjacent to the fluid supply port and at the other end of the flow path adjacent to the fluid discharge port, the large resistance flow path portion making a flow path resistance in a fluid supply direction from the fluid supply port greater than a flow path resistance in a direction perpendicular to the fluid supply port; a small resistance flow path section formed in the flow path region at a position not adjacent to the fluid supply port and the fluid discharge port and adjacent to the large resistance flow path section in a direction perpendicular to the fluid supply direction, the small resistance flow path section having a flow path resistance in the fluid supply direction smaller than that of the large resistance flow path section; A separator comprising:

2. the large resistance flow path portion and the small resistance flow path portion are formed in an uneven pattern in which a concave shape on one side of the separator body becomes a convex shape on the other side; The separator according to claim 1 .

3. a supply header formed adjacent to the large resistance flow path section and the small resistance flow path section between the fluid supply port and the flow path region, for sending fluid to the flow path region; a discharge header formed adjacent to the large resistance flow path portion and the small resistance flow path portion between the fluid discharge port and the flow path region, for discharging the fluid from the flow path region; The separator according to claim 1 or claim 2, comprising:

4. When viewed in the thickness direction, the large resistance flow path portion and the small resistance flow path portion each have a reference portion, a first recess that is recessed on one side of the reference portion, and a second recess that is recessed on the other side of the reference portion, and the fluid supply port and the fluid discharge port are formed in the reference portion. The separator according to claim 3 .

5. The supply header and the discharge header are formed flush with the reference portion when viewed in the thickness direction. The separator according to claim 4.

6. The large resistance flow path portion and the small resistance flow path portion are formed on both one and the other plate surfaces of the separator body. The separator according to any one of claims 1 to 5.

7. the large resistance flow path portion is formed in a concave shape extending in a direction intersecting the fluid supply direction, and the small resistance flow path portion is formed in a concave shape extending in a direction perpendicular to the extension direction of the large resistance flow path portion. The separator according to any one of claims 1 to 6.

8. The small resistance flow path portion is formed in a concave shape that is shorter in a direction intersecting the fluid supply direction than the large resistance flow path portion. The separator according to claim 7.

9. A water electrolysis device comprising the separator according to any one of claims 1 to 8.

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