JP7808969B2 - Separator and water electrolysis device - Google Patents

Description

The present invention relates to a separator and a water electrolysis device using this separator.

In recent years, water electrolysis devices that generate hydrogen and fuel cell devices that use hydrogen to generate electricity have been attracting attention as ways to utilize clean energy. 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 provide a continuous supply of electricity even when renewable energy sources are unstable.

For such water electrolysis devices and fuel cell devices, development is also underway regarding 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).

JP 2020-136218 A

In such water electrolysis devices and fuel cell devices, separators are used to form flow paths that supply and diffuse fluids such as water and gas. If the separator can efficiently supply and diffuse fluids such as water and gas, power generation efficiency and water electrolysis efficiency will improve, so there is a demand for improvements in separator flow paths.

The present invention was made in consideration of the above, and aims to provide a separator that can efficiently supply and diffuse fluids such as water and gas, and a water electrolysis device that uses this separator.

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 body 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; high 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, the high resistance flow path sections 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 small resistance flow path section formed in the flow path region at a position not adjacent to the fluid supply port or the fluid discharge port and adjacent to the high resistance flow path section in the 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 high resistance flow path section.

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 fluid passes. In the flow path region, a high-resistance flow path section is formed adjacent to the fluid supply port and the fluid discharge port, and a low-resistance flow path section is formed in a position not adjacent to the fluid supply port and the fluid discharge port. The high-resistance flow path section has a higher flow path resistance in the fluid supply direction than in a direction perpendicular to this 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 low-resistance flow path section. 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 enabling efficient fluid supply and diffusion.

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

The separator according to claim 2 makes it easy to form flow paths in a relatively thin plate.

The separator according to claim 3 includes a supply header formed adjacent to the high resistance flow path section and the low 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 high resistance flow path section and the low resistance flow path section between the fluid discharge port and the flow path region, for discharging fluid from the flow path region.

The separator according to claim 3 allows fluid to be delivered from the supply header to both the high resistance flow path section and the low resistance flow path section, allowing the fluid to be smoothly dispersed to areas not adjacent to the fluid supply port. Furthermore, the discharge header allows the fluid to be smoothly discharged from the flow path area.

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

According to the separator of claim 4, the fluid supply port and fluid discharge port can be easily connected to the recesses of the concave-convex pattern on both one side and the other side of a single separator.

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.

The separator according to claim 5 makes it easy to form supply and discharge headers.

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

The separator according to claim 6 allows for the formation of flow channels for different fluids on one side and the other side of a single separator.

In the separator according to claim 7, the large resistance flow path section is formed as a recess extending in a direction intersecting the fluid supply direction, and the small resistance flow path section is formed as a recess extending in a direction perpendicular to the extension direction of the large resistance flow path section.

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

In the separator according to claim 8, the small resistance flow path section is concave and shorter in the direction intersecting the fluid supply direction than the large resistance flow path section.

According to the separator of claim 8, by making the recess shorter than the high-resistance flow path portion, it is possible to easily form a low-resistance flow path portion with lower flow path resistance than the high-resistance flow path portion.

The water electrolysis device according to claim 9 includes the separator according to any one of claims 1 to 8.

In the water electrolysis device of claim 9, the separator allows for good supply and diffusion of fluids such as water and gas, thereby improving water electrolysis efficiency.

The separator according to the present invention allows for good supply and diffusion of fluids such as water and gas.

FIG. 2 is a plan view of the anode side of the separator used in the water electrolysis apparatus according to the first embodiment. 2 is a cross-sectional view of a cell of a portion corresponding to line 2-2 in FIG. 1 of the water electrolysis device according to the first embodiment. FIG. 3 is a cross-sectional view of a portion of the water electrolysis device according to the first embodiment taken along line 3-3 in FIG. 1. FIG. FIG. 4 is a partial plan view of a large resistance flow path portion. FIG. 4 is a partial plan view of a small resistance flow path portion. FIG. 4 is a partial plan view of a resistance intermediate flow passage portion. 4A is a cross-sectional view of the large resistance flow path portion taken along line A-A in FIG. 4, FIG. 5B is a cross-sectional view of the small resistance flow path portion taken along line B-B in FIG. 5, and FIG. 6C is a cross-sectional view of the medium resistance flow path portion taken along line C-C in FIG. 6. FIG. 2 is a plan view of the cathode side of the separator used in the water electrolysis apparatus according to the first embodiment. 1A is a cross-sectional view of a large resistance flow path portion, FIG. 1B is a cross-sectional view of a small resistance flow path portion, and FIG. 1C is a cross-sectional view of a medium resistance flow path portion. 1A is an explanatory diagram showing the flow of water in a flow channel region of the present embodiment, and FIG. 1B is an explanatory diagram showing the flow of water in a flow channel region of a comparative example. FIG. 10 is a partial plan view of a small resistance flow path portion according to a modified example. 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. FIG. 10 is a plan view of the anode side of a separator used in a water electrolysis apparatus according to a second embodiment.

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.

As shown in Figures 2 and 3, the cell 20 includes an electrolyte layer 22. An anode catalyst layer 24, an anode gas diffusion layer 25, and a separator 26 are stacked in this order on one side of the electrolyte layer 22. Furthermore, a cathode catalyst layer 34, a cathode gas diffusion layer 35, and a separator 36 are stacked in this order on the other side of the electrolyte layer 22.

The electrolyte layer 22 is rectangular and can be made of a carbon-fluorine polymer membrane or a carbon-fluorine polymer membrane. The anode catalyst layer 24 laminated on one side of the electrolyte layer 22 covers the inner periphery of one side 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 side of the electrolyte layer 22 covers the inner periphery of the other side 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.

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 material, a powder sintered material, a fiber sintered material, a metal mesh, or felt.

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

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 material, a powder sintered material, a fiber sintered material, a metal mesh, or felt.

A separator 36 is laminated on the cathode gas diffusion layer 35. Details of the separator 36 will be described later. A voltage is applied between the separator 26 and the separator 36 by the voltage application means 11.

As shown in Figure 1, the separator 26 is composed of a rectangular plate-shaped separator body 27, which has fluid openings 28 and a flow path region 40 formed in it. Note that Figure 1 is a plan view of the cross section of Figures 2 and 3, viewed from below.

A fluid opening 28 is 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 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 one side, sealing the space between the separator body 27 and the electrolyte layer 22.

The flow path region 40 is a region through which 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 large resistance flow path section 42, a small resistance flow path section 44, and a medium resistance flow path section 46.

As shown in FIG. 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 end of the flow path adjacent to the fluid supply port 28A (region A1) and the other end of the flow path adjacent to the fluid discharge port 28B (region D1). As shown in FIG. 4, in a plan view, the large resistance flow path section 42 is formed by alternately arranging elongated holes 42A in the Y direction perpendicular to the fluid supply direction X and elongated convex shapes 42B 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.

The small resistance flow path section 44 is formed in regions B1 and C1 of the flow path region 40, which are not adjacent to the fluid supply port 28A and fluid discharge port 28B. As shown in FIG. 5 , the small resistance flow path section 44 has a configuration in which the large resistance flow path section 42 is rotated 90 degrees 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 same direction 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.

The medium resistance flow path section 46 is located in the center of the flow path region 40. As shown in FIG. 6 , in a plan view, the medium resistance flow path section 46 is formed 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 length of the elongated holes 46A and convex shapes 46B in the fluid supply direction X is set shorter than the length of the elongated holes 42A and 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 low flow path resistance in the Y direction.

The flow path resistance in the fluid supply direction X of the high-resistance flow path section 42, medium-resistance flow path section 46, and small-resistance flow path section 44 is highest in the high-resistance flow path section 42 and lowest in the small-resistance flow path section 44, with the medium-resistance flow path section 46 being lower than the high-resistance flow path section 42 and higher than the small-resistance flow path section 44.

As shown in Figures 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 an uneven pattern in which a concave shape on one side of the separator body 27 becomes a convex shape on the other side when viewed in the thickness direction (cross-sectional view). The uneven 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 second recessed section γ are set to the same depth.

7A, 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 a first recess β, and a second recess γ 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 with a first recess β, and a second recess γ 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 with a first recess β, and a second recess γ and a reference portion α are formed between adjacent elongated holes 46A. The first recess β and the second recess γ have opposite concavities and convexities on one surface and the other surface; that is, the first recess β is concave on one surface and convex on the other surface, and the second recess γ is convex on one surface and concave on the other surface. Such a pattern with projections and recesses on both sides can be easily formed using double-sided pressing.

As shown in FIG. 1, on one side of the separator body 27 across the flow path region 40, a supply header 50 is formed in the area other than the fluid openings 28, continuing from the large resistance flow path section 42 and the small resistance flow path section 44. As shown in FIG. 3, the supply header 50 is formed as a flat surface flush with the reference section α.

On the other side of the separator body 27 across the flow path region 40, in the area other than the fluid openings 28, a discharge header 52 is formed, continuing from the high-resistance flow path section 42 and the low-resistance flow path section 44. Like the supply header 50, the discharge header 52 is formed with a flat surface flush with the reference section α.

A peripheral sealing layer 54 is formed on the outer periphery of the separator body 27. As shown in FIG. 2, the peripheral sealing layer 54 seals the gap between the electrolyte layer 22 and the separator 26. As shown in FIG. 1, the peripheral sealing layer 54 is connected to the opening sealing member 56. The peripheral sealing layer 54 and opening sealing member 56 can be made of resin or rubber material.

As shown in Figure 2, the separator body 27 is positioned so that the bottom of the second recess γ is in contact with the anode gas diffusion layer 25. A space is then formed between the anode gas diffusion layer 25 and the first recess β and reference portion α, forming a fluid passageway.

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

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 composed 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.

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

As shown in FIG. 9(A), on one surface, the elongated holes 42A of the large resistance flow path section 42 are formed with the second recess γ, with a first recess β and a reference portion α formed between adjacent elongated holes 42A. Also, on one surface, the elongated holes 44A of the small resistance flow path section 44 are formed with the second recess γ, with a first recess β and a reference portion α formed between adjacent elongated holes 44A. Also, on one surface, the elongated holes 46A of the medium resistance flow path section 46 are formed with the second recess γ, with a first recess β and a reference portion α formed between adjacent elongated holes 46A. In other words, in the concavo-convex pattern, the other surface of the separator 26 becomes one surface of the separator 36.

As shown in Figure 2, in the separator 36, the separator body 37 is positioned so that the bottom of the first recess β is in contact with the cathode gas diffusion layer 35. A space is then formed between the cathode gas diffusion layer 35 and the second recess γ and reference portion α, which serves as a fluid passageway.

As shown in Figure 8, on one side of the flow path region 40 of the separator body 37, a supply header 50 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, a discharge header 52 is formed with a flat surface that is flush with the reference portion α.

A peripheral sealing layer 54 is formed on the outer periphery of the separator body 27. As shown in FIG. 2, the peripheral sealing layer 54 seals the gap between the electrolyte layer 22 and the separator 26. It is also connected to an opening sealing member 56. The peripheral sealing layer 54 and opening sealing member 56 can be made of resin or rubber material.

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

Next, we will explain the effects of this embodiment.

Water supplied from the fluid supply port 28A flows into the supply header 50 and then flows from the supply header 50 into the flow path region 40. The flow path region 40 has a large-resistance flow path section 42 in region A1 adjacent to the fluid supply port 28A via the supply header 50. This reduces the inflow of water into region A1 compared to when regions A and B have the same flow path resistance. On the other hand, a small-resistance flow path section 44 is provided in region B1, which is not adjacent to the fluid supply port 28A, promoting the inflow of water into region B1. This reduces the amount of water that flows linearly from the fluid supply port 28A to the fluid discharge port 28B, allowing for good diffusion of the supplied water in the flow path region 40.

In the water electrolysis device 10A, when a voltage is applied between the separator 26 and the separator 36, the following reaction (1) occurs on the surface of the anode catalyst layer 24.

H ₂ O → 2H ⁺ + 0.5O ₂ + 2e ^- (1)

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.

The hydrogen ions H ⁺ move through the electrolyte layer 22 to the cathode side, obtain electrons ^e- supplied by external wiring (reaction (2)), and become hydrogen H2. The hydrogen ions _H2 are diffused in the cathode gas diffusion layer 35, pass through the discharge header 52, and are discharged from the cathode fluid discharge port 28C.

2H ⁺ + 2e ^- → H ₂ (2)

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

Figure 10 shows the fluid flow when all fluid resistances in the flow path region 40 are set to the same (B), and the fluid flow when regions with different fluid resistances are provided as in this embodiment (A). When all fluid resistances in the flow path region 40 are set to the same, as shown in Figure 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 Figure 10(A), and the fluid can be diffused throughout the entire flow path region 40.

In addition, this embodiment has a supply header 50 and a discharge header 52, so 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, allowing water to be smoothly dispersed to areas not adjacent to the fluid supply port 28A. Furthermore, the discharge header 52 allows water to be smoothly discharged from the flow path area 40.

In addition, in this embodiment, the large resistance flow path section 42, small resistance flow path section 44, and medium resistance flow path section 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, allowing the thickness of the separators 26, 37 to be reduced.

In addition, in this embodiment, the fluid supply port 28A and the fluid discharge port 28B are formed in the reference portion α. 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 one side and the other side of a single separator 26, 36.

In addition, in this embodiment, the supply header 50 and discharge header 52 are formed flush with the reference portion α when viewed in the thickness direction. Therefore, the supply header 50 and discharge header 52 can be easily formed.

In addition, in this embodiment, a flow path region 40 having a large resistance flow path section 42, a small resistance flow path section 44, and a medium resistance flow path section 46 is formed on both one and the other sides of the plate surface of the separator body 27, 37. Therefore, flow paths for flowing different fluids can be formed on one and the other sides of a single separator 26, 36.

In addition, in this embodiment, the large resistance flow path section 42 is formed as an elongated hole extending in a direction perpendicular to the fluid supply direction X, and the small resistance flow path section 44 is formed as 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 easy to make the fluid flow in a direction different from the fluid supply direction.

In this embodiment, the flow path resistance of the large resistance flow path section 42 and the small resistance flow path section 44 is differentiated by changing the elongated hole extension direction. However, the flow path resistance may also be differentiated 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 Figure 11, the flow path resistance can be reduced by using a circular concave-convex pattern in plan view.

Furthermore, as shown in Figure 12, multiple cells 20 of this embodiment can be stacked to form a cell stack 20S. In this case, one side of one separator 26 can be placed opposite the anode gas diffusion layer 25, and the other side can be placed opposite the cathode gas diffusion layer 35, in the same manner as one side of the separator 36.

Furthermore, by using the separator 26 of this embodiment in the water electrolysis device 10A, one side can be used as the anode side to supply water, and the other side can be used as the cathode side to recover hydrogen gas. Therefore, even if the concave and convex sides of the separator 26 are reversed, different fluids can be suitably flowed on the front and back of a single separator 26.

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 designated by the same reference numerals, and detailed description thereof will be omitted.

The water electrolysis device 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; the rest of the configuration is the same as the first embodiment.

As shown in FIG. 13, the 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. A fluid supply port 28A is formed in the protrusion 66A, and a fluid discharge port 28B is formed in the protrusion 66B. In the description of this embodiment, fluid openings other than the fluid supply port 28A and the fluid discharge port 28B are omitted.

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 as region A2, the two middle sections as region B2, and the other end as region C2, the high-resistance flow path section 42 is formed in one end of the flow path (region B2) adjacent to the fluid supply port 28A and the fluid discharge port 28B. The low-resistance flow path section 44 is formed in regions A2 and C2 of the flow path region 40 that are not adjacent to the fluid supply port 28A and the fluid discharge port 28B.

On one side of the separator body 27 across the flow path region 40, a supply header 50 is formed in the area other than the fluid openings 28, continuing from 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 the area other than the fluid openings 28, continuing from the large resistance flow path section 42 and the small resistance flow path section 44.

Even when using the separator 66 of this embodiment, fluid can flow throughout the entire flow path region 40.

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

In addition, 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 may also be used.

In addition, in the above-described embodiments, the separators 26, 36 are formed with supply headers 50 and discharge headers 52, but it is also possible to form separate sealing members in the areas of the supply headers 50 and discharge headers 52.

In addition, in the above-described embodiments, the first recess β and the second recess γ of the separators 26, 36 were set to the same depth, but the depth may be changed depending on the application. For example, in the separator 26 that forms the anode-side flow path of the water electrolysis device as in this embodiment, the first recess β on one side can be made deeper than the second recess γ on the other side. By setting it in this way, fluid can be efficiently passed through the front and back of the separator depending on the fluid flow rate.

Furthermore, while the above-described embodiments have been described using a polymer electrolyte membrane (PEM) water electrolysis device as an example, the present invention can also be used in an anion exchange membrane (AEM) water electrolysis device.

10A, 10B Water electrolysis apparatus (water electrolysis device)
26, 66 Separator 27 Separator body 28A Fluid supply port 28B Fluid discharge port 40 Flow path region 42 Large resistance flow path section 44 Small resistance flow path section 50 Supply header 52 Discharge header α Reference section β First recess γ Second recess X Fluid supply direction

Claims (9)

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: 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 . 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: 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 . 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. 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. 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. 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. A water electrolysis device equipped with the separator described in any one of claims 1 to 8.