Method for producing electrolytic cell

Abstract

To provide a method for producing an electrolytic cell that reduces a risk of positional displacement occurring during production of the electrolytic cell.SOLUTION: A method for producing an electrolytic cell (12) comprises a joining step of joining a frame portion (48b) of a protective sheet member (48) provided between an electrolyte membrane-electrode structure (30) and a fluid supply side current collector (42) and a portion of the electrolyte membrane-electrode structure (30) outside a covered portion (40a) where an electrolyte membrane (40) is covered with an electrode catalyst layer (42a) to form a joined portion, and a joined body stacking step of stacking the joined electrolyte membrane-electrode structure (30) and protective sheet member (48) on the fluid supply side current collector (42) in a state where the protective sheet member (48) faces toward the fluid supply side current collector (42).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing an electrolysis cell. [Background technology]

[0002] There is an electrolysis stack comprising a stack of multiple electrolysis cells. Electrolysis cells include water electrolysis cells that electrolyze water and hydrogen electrolysis cells that electrolyze hydrogen (hydrogen gas). An electrolysis stack comprising a stack of multiple water electrolysis cells is sometimes called a water electrolysis device. An electrolysis stack comprising a stack of multiple hydrogen electrolysis cells is sometimes called an EHC (Electrochemical Hydrogen Compressor).

[0003] Patent Document 1 below discloses a water electrolysis device including water electrolysis cells. In this water electrolysis device, multiple water electrolysis cells are stacked. Each water electrolysis cell includes a membrane electrode assembly, a pair of power feeders disposed on both sides of the membrane electrode assembly, and a protective sheet member provided between one of the pair of power feeders and the membrane electrode assembly. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-157212 Summary of the Invention [Problem to be solved by the invention]

[0005] An electrolysis cell is manufactured by stacking a membrane electrode assembly, a pair of power feeders, and a protective sheet member in a predetermined order. It is desirable to reduce the risk of misalignment during the manufacture of an electrolysis cell.

[0006] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0007] An aspect of the present disclosure is a method for manufacturing an electrolysis cell comprising: an electrolyte membrane having a through hole formed therein; and a pair of electrode catalyst layers provided on both sides of the electrolyte membrane and covering a region of the electrolyte membrane between the peripheral region of the through hole and the outer peripheral region; a pair of power feeders arranged on both sides of the electrolyte membrane electrode assembly; and a protective sheet member provided between one of the pair of power feeders and the electrolyte membrane electrode assembly, one of the pair of power feeders being a fluid supply side power feeder to which a fluid used for electrolysis is supplied, the protective sheet member being configured with a central portion facing a covered portion of the electrolyte membrane that is covered by the electrode catalyst layer, and a frame portion outside the central portion, the method comprising: a joining step of joining the frame portion and the region of the electrolyte membrane electrode assembly outside the covered portion to form a joint; and an assembly lamination step of stacking the joined electrolyte membrane electrode assembly and protective sheet member on the fluid supply side power feeder with the protective sheet member facing the fluid supply side power feeder. [Effects of the Invention]

[0008] According to an aspect of the present disclosure, it is possible to prevent misalignment of the protective sheet member without a dedicated restraining member for the protective sheet member, thereby reducing the risk of misalignment occurring during the manufacture of the electrolysis cell. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of an electrolysis stack according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of an electrolysis cell that constitutes the electrolysis stack. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a flowchart showing the steps of the method for manufacturing an electrolytic cell. [Figure 5] FIG. 5 is a diagram showing a joined body joined at a joint. [Figure 6] FIG. 6 is a diagram showing another joined body joined at a joint. [Figure 7] FIG. 7 is a diagram showing the state after the first arrangement step. [Figure 8] FIG. 8 is a diagram showing a state in which the bonded bodies shown in FIG. 5 are stacked. DETAILED DESCRIPTION OF THE INVENTION

[0010] As shown in Fig. 1, the electrolysis stack 10 according to this embodiment includes a stack 14 in which multiple electrolysis cells 12 are stacked vertically (in the direction of arrow A) or horizontally (in the direction of arrow B). The electrolysis cells 12 may be water electrolysis cells. Alternatively, the electrolysis cells 12 may be hydrogen electrolysis cells.

[0011] The electrolysis stack 10 further includes a plurality of electrolytic cells 12, a pair of terminal plates 16a, 16b, a pair of insulating plates 18a, 18b, and a pair of end plates 20a, 20b. The terminal plate 16a, the insulating plate 18a, and the end plate 20a are arranged in this order upward at one end (upper end) of the stack 14 in the stacking direction. The terminal plate 16b, the insulating plate 18b, and the end plate 20b are arranged in this order downward at the other end (lower end) of the stack 14 in the stacking direction.

[0012] The electrolysis stack 10 is fastened in the stacking direction. For example, the electrolysis stack 10 is held in a state in which the end plates 20a, 20b are integrally fastened by a pressing mechanism such as a plurality of tie rods 22 extending in the direction of arrow A. The electrolysis stack 10 may be integrally held by a box-shaped casing (not shown) that includes the end plates 20a, 20b as end plates. The electrolysis stack 10 has a generally cylindrical shape as a whole, but may be set to various shapes such as a cube.

[0013] Terminal portions 24a, 24b are provided on the sides of the terminal plates 16a, 16b so as to protrude outward. An electrolysis power supply 28 is electrically connected to the terminal portions 24a, 24b via wires 26a, 26b.

[0014] 2 and 3, the electrolysis cell 12 includes a substantially disk-shaped membrane electrode assembly 30, and a first separator 32 and a second separator 34 that sandwich the membrane electrode assembly 30 and other components. A resin frame member 36 is disposed between the first separator 32 and the second separator 34 so as to surround the membrane electrode assembly 30 and other components.

[0015] The resin frame member 36 has a generally ring shape, and seal members 37a, 37b (see FIG. 3 ) are provided on both sides of the resin frame member 36. One radial end (arrow B direction) of the resin frame member 36 is provided with a fluid inlet hole 38a extending along the stacking direction (arrow A direction). The fluid inlet hole 38a is formed to introduce a fluid used for electrolysis. The fluid inlet holes 38a of the stacked electrolytic cells 12 communicate with each other. The other radial end (arrow B direction) of the resin frame member 36 is provided with a fluid outlet hole 38b extending along the stacking direction (arrow A direction). The fluid outlet hole 38b is formed to discharge a mixed fluid containing unreacted fluids that have not been electrolyzed. The fluid outlet holes 38b of the stacked electrolytic cells 12 communicate with each other.

[0016] As shown in Fig. 1 , a fluid inlet 39a is provided on a side of the resin frame member 36 of one of the electrolytic cells 12 located at one end (lower end) in the stacking direction (direction of arrow A). The fluid inlet 39a is connected to a fluid inlet hole 38a (see Figs. 2 and 3 ). A fluid outlet 39b is provided on a side of the resin frame member 36 of one of the electrolytic cells 12 located at the other end (upper end) in the stacking direction (direction of arrow A). The fluid outlet 39b is connected to a fluid outlet hole 38b (see Figs. 2 and 3 ).

[0017] As shown in Figures 2 and 3, each electrolytic cell 12 is provided with a high-pressure fluid outlet hole 38c that penetrates the radial center along the stacking direction. The high-pressure fluid outlet hole 38c is formed to pressurize and discharge gas generated by electrolysis of the fluid used in electrolysis. The high-pressure fluid outlet holes 38c of the multiple stacked electrolytic cells 12 are connected to each other. The gas supplied to the high-pressure fluid outlet hole 38c is discharged at a pressurized state of, for example, 1 MPa to 80 MPa.

[0018] The first separator 32 and the second separator 34 are generally disk-shaped and made of, for example, a carbon material. The first separator 32 and the second separator 34 may also be formed by press-molding a steel plate, a stainless steel plate, a titanium plate, an aluminum plate, a plated steel plate, or a metal plate whose metal surface has been treated for corrosion prevention. Alternatively, the first separator 32 and the second separator 34 may be formed by cutting the plate and then treating it for corrosion prevention.

[0019] The membrane electrode assembly 30 is composed of a ring-shaped electrolyte membrane 40 made of a solid polymer, a first electrode catalyst layer 42a, and a second electrode catalyst layer 44a. The membrane electrode assembly 30 is disposed between a first power feeder 42 and a second power feeder 44.

[0020] The electrolyte membrane 40 is a membrane capable of exchanging ions. The first electrode catalyst layer 42a is an electrode catalyst layer (fluid supply side catalyst layer) to which a fluid used in electrolysis is supplied. The first power supply 42 is a power supply (fluid supply side power supply) to which a fluid used in electrolysis is supplied. The second electrode catalyst layer 44a is an electrode catalyst layer on the opposite side to the first electrode catalyst layer 42a. The second power supply 44 is a power supply on the opposite side to the first power supply 42. The first electrode catalyst layer 42a may also be simply referred to as the electrode catalyst layer 42a. The same applies to the second electrode catalyst layer 44a. The first power supply 42 may also be simply referred to as the power supply 42. The same applies to the second power supply 44.

[0021] When the electrolysis cell 12 is a water electrolysis cell, the electrolyte membrane 40 may be an anion exchange membrane or a proton exchange membrane. When the electrolyte membrane 40 is an anion exchange membrane, the fluid used for electrolysis is alkaline water. When the electrolyte membrane 40 is an anion exchange membrane, the electrode catalyst layer 42a and the power supply 42 are the anode, and the electrode catalyst layer 44a and the power supply 44 are the cathode, the gas supplied to the high-pressure fluid outlet hole 38c (see FIG. 1) is hydrogen produced by electrolysis. In this case, the mixed fluid discharged from the fluid outlet 39b (see FIG. 1) contains unreacted water that has not been electrolyzed and oxygen produced by electrolysis. On the other hand, when the electrolyte membrane 40 is an anion exchange membrane, the electrode catalyst layer 42a and the power supply 42 are the cathode, and the electrode catalyst layer 44a and the power supply 44 are the anode, the gas supplied to the high-pressure fluid outlet hole 38c (see FIG. 1) is oxygen produced by electrolysis. In this case, the mixed fluid discharged from the fluid outlet 39b (see FIG. 1) contains unreacted water that has not been electrolyzed and hydrogen that has been produced by electrolysis.

[0022] When the electrolysis cell 12 is a water electrolysis cell and the electrolyte membrane 40 is a proton exchange membrane, the fluid used for electrolysis is water (e.g., pure water) containing impurities at a predetermined level or less. When the electrolyte membrane 40 is a proton exchange membrane, the electrode catalyst layer 42a and the power supply 42 are the anode, and the electrode catalyst layer 44a and the power supply 44 are the cathode, the gas supplied to the high-pressure fluid outlet hole 38c (see FIG. 1) is hydrogen produced by electrolysis. In this case, the mixed fluid discharged from the fluid outlet 39b (see FIG. 1) contains unreacted water that has not been electrolyzed and oxygen produced by electrolysis. On the other hand, when the electrolyte membrane 40 is a proton exchange membrane, the electrode catalyst layer 42a and the power supply 42 are the cathode, and the electrode catalyst layer 44a and the power supply 44 are the anode, the gas supplied to the high-pressure fluid outlet hole 38c (see FIG. 1) is oxygen produced by electrolysis. In this case, the mixed fluid discharged from the fluid outlet 39b (see FIG. 1) consists of unreacted water that has not been electrolyzed and hydrogen that has been produced by electrolysis.

[0023] When the electrolysis cell 12 is a hydrogen electrolysis cell, the electrolyte membrane 40 is a proton exchange membrane. In this case, the fluid used for electrolysis is hydrogen. The electrode catalyst layer 42a and the power supply 42 form the anode, and the electrode catalyst layer 44a and the power supply 44 form the cathode. The gas supplied to the high-pressure fluid outlet hole 38c (see FIG. 1) is hydrogen produced by electrolysis. The mixed fluid discharged from the fluid outlet 39b (see FIG. 1) contains unreacted hydrogen that has not been electrolyzed and water vapor.

[0024] A through-hole 40h is formed in the electrolyte membrane 40 approximately at the center in the radial direction. This through-hole 40h is part of the high-pressure fluid outlet hole 38c provided in the electrolysis cell 12. A first electrode catalyst layer 42a is provided on part of one surface of the electrolyte membrane 40. The first electrode catalyst layer 42a is provided on one surface of the electrolyte membrane 40, in a region between the peripheral portion and outer peripheral portion of the through-hole 40h of the electrolyte membrane 40. A second electrode catalyst layer 44a is provided on part of the other surface of the electrolyte membrane 40. The second electrode catalyst layer 44a is provided on the other surface of the electrolyte membrane 40, in a region between the peripheral portion and outer peripheral portion of the through-hole 40h of the electrolyte membrane 40. The first electrode catalyst layer 42a and the second electrode catalyst layer 44a are formed, for example, in a ring shape.

[0025] The electrolyte membrane 40 has a covered portion 40a covered by a pair of electrode catalyst layers 42a, 44a, and an exposed portion 40b exposed from the electrode catalyst layers. In the electrolysis cell 12, the area facing the covered portion 40a in the stacking direction forms the electrolysis region. The exposed portions 40b are provided on the radially central side and outer side of the electrolysis region, in other words, on the peripheral and outer peripheral portions of the through-holes 40h in the electrolyte membrane 40. Hereinafter, the peripheral portion of the through-holes 40h in the exposed portion 40b will also be referred to as a first exposed portion 41a. Furthermore, the radially outer portion of the exposed portion 40b (the outer peripheral portion) of the electrolysis region will also be referred to as a second exposed portion 41b.

[0026] The exposed portion 40b of the electrolyte membrane 40 has a smaller ion exchange capacity (IEC) than the covered portion 40a. The ion exchange capacity here is the reciprocal (meq / g) of the weight of the electrolyte membrane 40 in a dry state required to be able to exchange one mole of ions.

[0027] The first electrode catalyst layer 42a uses, for example, a Ru (ruthenium)-based catalyst, and the second electrode catalyst layer 44a uses, for example, a platinum catalyst. The first power supply body 42 and the second power supply body 44 are made of, for example, a sintered body (porous conductor) of spherical atomized titanium powder. The first power supply body 42 and the second power supply body 44 have smooth surfaces that are etched after grinding, and the porosity is set to a range of 10% to 50%, preferably 20% to 40%.

[0028] The inner and outer diameters of the first and second power feeders 42, 44 are set so that they are disposed in the electrolysis region. Therefore, the radially central ends of the first and second power feeders 42, 44 are respectively disposed at a radial distance from the high-pressure fluid outlet hole 38c.

[0029] A frame 42e is fitted onto the outer periphery of the first current feeder 42. The frame 42e is configured to be denser than the first current feeder 42. Note that by configuring the outer periphery of the first current feeder 42, which extends radially outward from the electrolysis region, to be dense, the outer periphery can also be used as the frame 42e.

[0030] The first separator 32 and the resin frame member 36 form a first chamber 45an between themselves and the electrolyte membrane 40, in which a first power supply body 42 is housed. The second separator 34 and the resin frame member 36 form a second chamber 45ca between themselves and the electrolyte membrane 40, in which a second power supply body 44 is housed.

[0031] A flow path member 46 is interposed between the first separator 32 and the first current feeder 42 (first chamber 45an), and a protective sheet member 48 is interposed between the first current feeder 42 and the first electrode catalyst layer 42a. As shown in Fig. 2, the flow path member 46 has a substantially disk shape, and an inlet protrusion 46a and an outlet protrusion 46b that face each other in the radial direction are formed on the outer periphery thereof.

[0032] The inlet protrusion 46a is formed with a supply connection passage 50a that communicates with the fluid introduction hole 38a, and the supply connection passage 50a communicates with a fluid flow path 50b (see FIG. 3). A plurality of holes 50c communicate with the fluid flow path 50b, and the holes 50c open toward the first power feed body 42. The outlet protrusion 46b is formed with a discharge connection passage 50d that communicates with the fluid flow path 50b, and the discharge connection passage 50d communicates with the fluid outlet hole 38b.

[0033] As shown in Figures 2 and 3, the protective sheet member 48 has a substantially circular shape when viewed in the stacking direction, with its inner periphery positioned inward relative to the inner periphery of the first current feeder 42 and its outer periphery positioned at the same position as the outer peripheries of the electrolyte membrane 40 and the frame portion 42e. The protective sheet member 48 is composed of a central portion 48a and a frame portion 48b. The central portion 48a is surrounded by the frame portion 48b. The central portion 48a faces the covering portion 40a. The central portion 48a is disposed within the electrolysis region. The outer edge of the electrolysis region and the outer edge of the central portion 48a coincide with each other, but this is not limited to this. A plurality of communication holes 48c are formed in the central portion 48a. The frame portion 48b is positioned radially outward relative to the central portion 48a. For example, rectangular holes (not shown) are formed in the frame portion 48b.

[0034] As shown in FIG. 3 , the protective sheet member 48 and the membrane electrode assembly 30 are joined at a joint 49. The joint 49 joins the frame portion 48b of the protective sheet member 48 and the second exposed portion 41b of the electrolyte membrane 40. The joint 49 is located between a boundary position P1 between the central portion 48a and the frame portion 48b of the protective sheet member 48 and the outer peripheral edge E1 of the frame portion 48b. The joint 49 does not abut against the boundary position P1 and is spaced apart from the boundary position P1. Similarly, the joint 49 does not abut against the outer peripheral edge E1 and is spaced apart from the outer peripheral edge E1. Preferably, the joint 49 is located approximately midway between the boundary position P1 and the outer peripheral edge E1.

[0035] In this embodiment, the joint 49 is located outside the boundary position P1 and inside the pressure-resistant member 74 described below. When the joint 49 is located inside the pressure-resistant member 74, the joint 49 is not interposed between the pressure-resistant member 74 and the protective sheet member 48. Therefore, tolerances in the thickness direction (stacking direction) of the electrolysis cell 12 due to the joint 49 are unlikely to occur.

[0036] A generally cylindrical communicating-hole body 52 surrounding the high-pressure fluid discharge hole 38c is disposed radially center between the first separator 32 and the electrolyte membrane 40. Note that hereinafter, the flow path member 46, the first power supply member 42, and the protective sheet member 48 may be collectively referred to as the first electrode side member. In this case, the communicating-hole body 52 is disposed between the high-pressure fluid discharge hole 38c and the first electrode side member in the radial direction of the high-pressure fluid discharge hole 38c.

[0037] The communication hole body 52 includes an inner pipe member 54 made of a porous material facing the high-pressure fluid outlet hole 38c, and an outer pipe member 55 disposed between the inner pipe member 54 and the first electrode member. Storage chambers 55a and 55b are provided on the side of the outer pipe member 55 facing the inner pipe member 54. The storage chambers 55a and 55b are formed by cutting out ring-shaped notches on the radially central side and both ends of the outer pipe member 55 in the axial direction (stacking direction), and seal members (O-rings) 56a and 56b are disposed therein, surrounding the high-pressure fluid outlet hole 38c. This seals the high-pressure fluid outlet hole 38c from the first chamber 45an (the first power feeder 42 side).

[0038] As shown in FIGS. 2 and 3, on the side of the outer pipe member 55 facing the first electrode side member, a groove 55s in which a protective sheet member 48 is disposed is formed on the end surface facing the electrolyte membrane 40.

[0039] The second power supply body 44 and a load-applying mechanism 58 (FIG. 3) that presses the second power supply body 44 against the second electrode catalyst layer 44a are disposed in the electrolysis region within the second chamber 45ca. The load-applying mechanism 58 includes, for example, a conductive elastic member such as a leaf spring 60, and the leaf spring 60 applies a load to the second power supply body 44 via a metal leaf spring holder (shim member) 62. Note that, in addition to the leaf spring 60, a disc spring, a coil spring, or the like can also be used as the elastic member.

[0040] A resin sheet 68, for example, is disposed radially closer to the center than the electrolysis region in the second chamber 45ca as an insulating member that covers the first exposed portion 41a of the electrolyte membrane 40. The resin sheet 68 is set to have approximately the same thickness as the second power feeder 44 and is ring-shaped with a high-pressure fluid outlet hole 38c formed approximately in the radial center. The resin sheet 68 may be made of, for example, PEN (polyethylene naphthalate) or a polyimide film.

[0041] The second power feeder 44 and the surface of the resin sheet 68 facing the leaf spring holder 62 are covered with a conductive sheet 66. The conductive sheet 66 is made of a metal sheet such as titanium, SUS, or iron, and has a ring shape with the high-pressure fluid outlet hole 38c formed approximately in the radial center.

[0042] A tubular member 70 is disposed between the load-applying mechanism 58 and the high-pressure fluid discharge hole 38c in the radial direction, and between the conductive sheet 66 and the second separator 34 in the stacking direction. The tubular member 70 has a cylindrical shape and is made of a conductive material such as metal, and has the high-pressure fluid discharge hole 38c formed in its center. A discharge passage 71 that connects the second chamber 45ca and the high-pressure fluid discharge hole 38c is formed in one end surface of the tubular member 70 facing the second separator 34.

[0043] As described above, by disposing the through-hole body 52 (outer pipe member 55) and the tubular member 70 between the first separator 32 and the second separator 34, it is possible to improve the load-bearing capacity of the electrolysis cell 12 near the high-pressure fluid outlet hole 38c. In addition, the electrolyte membrane 40 (first exposed portion 41a), the resin sheet 68, and the conductive sheet 66 are sandwiched between the through-hole body 52 and the tubular member 70 at portions closer to the radial center than the electrolysis region (portions near the high-pressure fluid outlet hole 38c).

[0044] A sealing member (O-ring) 72 is disposed radially outside the electrolysis region in the second chamber 45ca so as to be interposed between the second exposed portion 41b of the electrolyte membrane 40 and the second separator 34. A pressure-resistant member 74 is disposed on the outer periphery of the sealing member 72. The pressure-resistant member 74 has a generally ring shape, and its outer periphery fits into the inner periphery of the resin frame member 36.

[0045] The electrolytic cell 12 is provided with a conductive path electrically connecting the second separator 34 to the tubular member 70, the conductive sheet 66, and the second power supply 44, and a conductive path electrically connecting the second separator 34 to the leaf spring 60, the leaf spring holder 62, the conductive sheet 66, and the second power supply 44.

[0046] Although not shown, the end plate 20a shown in FIG. 1 is provided with a pipe connected to the high-pressure fluid outlet hole 38c, and the pipe is provided with a back pressure mechanism that can regulate the discharge of gas through the high-pressure fluid outlet hole 38c.

[0047] The electrolysis stack 10 is basically constructed as described above. Next, a manufacturing method of the electrolysis stack 10 will be briefly described with reference to FIG.

[0048] First, stacking is performed in the reverse vertical direction of FIG. 1 on a jig (not shown) used for manufacturing the electrolytic stack 10. That is, the end plate 20a, the insulating plate 18a, and the terminal plate 16a are stacked in this order. Next, multiple electrolytic cells 12 are stacked on the terminal plate 16a. Next, the terminal plate 16b, the insulating plate 18b, and the end plate 20b are stacked in this order on the last-stacked electrolytic cell 12. Thereafter, the end plates 20a, 20b are held in an integrally clamped state by a pressing mechanism such as multiple tie rods 22. In this manner, the electrolytic stack 10 is manufactured.

[0049] Next, we will explain the method for manufacturing the electrolytic cell 12. Figure 4 is a flowchart showing the steps of the method for manufacturing the electrolytic cell 12. The method for manufacturing the electrolytic cell 12 includes a joining step S1, a first arrangement step S2, a second arrangement step S3, an assembled body lamination step S4, and a multiple-component lamination step S5.

[0050] The manufacturing method of the electrolysis cell 12 includes, but is not limited to, the following steps: joining step S1, first arrangement step S2, second arrangement step S3, assembly lamination step S4, and multiple-component lamination step S5. For example, the joining step S1 may be performed between the first arrangement step S2 and the second arrangement step S3. Alternatively, the joining step S1 may be performed between the second arrangement step S3 and the assembly lamination step S4.

[0051] The joining step S1 is a step of joining the frame portion 48b of the protective sheet member 48 to a portion of the membrane electrode assembly 30 that is outside the covered portion 40a (the second exposed portion 41b of the electrolyte membrane 40) to form a joint 49. An assembly 90 is obtained by the joining step S1 (see FIGS. 5 and 6). The assembly 90 is the protective sheet member 48 and the membrane electrode assembly 30 joined at the joint 49.

[0052] 5, the joint 49 may be provided in a ring shape surrounding the central portion 48a. In this case, the joint 49 is provided in a ring shape concentric with the boundary position P1, which is formed in a substantially circular shape when viewed from the stacking direction, on the outer side of the boundary position P1. The joint 49 is also provided in a ring shape concentric with the outer peripheral edge E1 of the frame portion 48b, which is formed in a substantially circular shape when viewed from the stacking direction. The joint 49 may also be provided in a ring shape concentric with the boundary position P1 and the outer peripheral edge E1, in an intermediate portion between the boundary position P1 and the outer peripheral edge E1, which are formed in a substantially circular shape.

[0053] Alternatively, as shown in Figure 6, the joint 49 is concentric with the boundary position P1 or the outer peripheral edge E1, which is formed in an approximately circular shape when viewed from the stacking direction, but multiple joints may be provided at intervals around the circumferential direction of the protective sheet member 48.

[0054] The bonding portion 49 is formed by, but is not limited to, welding. For example, the bonding portion 49 may be formed by adhesive. Note that when the bonding portion 49 is provided in a ring shape surrounding the central portion 48a, it is preferably formed by welding.

[0055] The first arrangement step S2 is a step of arranging the resin frame member 36. Specifically, as shown in Fig. 7, the resin frame member 36 is arranged by inserting the guide rod 102 of the jig 100 into the high-pressure fluid outlet hole 38h of the resin frame member 36. The guide rod 102 is fixed to the mounting base 104 of the jig 100 and extends in the vertical direction. Therefore, the guide rod 102 restricts displacement of the resin frame member 36 in a direction perpendicular to the guide rod 102 (the radial direction of the electrolysis cell 12).

[0056] 7 illustrates the production of the first stacked electrolytic cell 12. In this case, the resin frame member 36 is disposed on the terminal plate 16a. Although not shown, when producing the nth (n is an integer of 2 or more) stacked electrolytic cell 12, the resin frame member 36 is disposed on the first separator 32 (or the second separator 34) of the electrolytic cell 12 that is already stacked nth.

[0057] The second arrangement step S3 is a step of arranging the flow path member 46 (FIG. 2), the first power supply body 42 (FIG. 2), the seal members 56a and 56b (FIG. 2), the outer pipe member 55 (FIG. 2), and the inner pipe member 54 (FIG. 2). Specifically, as shown in FIG. 2, the guide rod 102 (FIG. 7) is inserted into the inner space of the inner pipe member 54. Next, the seal member 56b, the outer pipe member 55, and the seal member 56a are inserted into the inner pipe member 54. Next, the outer pipe member 55 is inserted into the through hole 46h of the flow path member 46, thereby arranging the flow path member 46 in the accommodation space 36AR, which is the interior of the resin frame member 36. Next, the outer pipe member 55 is inserted into the through hole 42h of the first power supply body 42, thereby arranging the first power supply body 42 in the accommodation space 36AR. The inner pipe member 54, into which the guide rod 102 is inserted, and the outer pipe member 55, which is inserted into the inner pipe member 54, restrict positional deviation of the flow path member 46 and the first power feeder 42 in a direction perpendicular to the guide rod 102. The inner space of the inner pipe member 54 forms part of the high-pressure fluid outlet hole 38c.

[0058] The assembly lamination step S4 is a step of laminating the assembly 90 obtained in the joining step S1. The through holes 40h (FIG. 5 or FIG. 6) formed in the electrolyte membrane 40 of the assembly 90 are inserted into the guide rods 102 (FIG. 7). As a result, the assembly 90 is laminated on the first power feeder 42 (FIG. 2) with the protective sheet member 48 facing the first power feeder 42. FIG. 8 shows the laminated state of the assembly 90 shown in FIG. 5.

[0059] A guide rod 102 is inserted into the through-hole 40h of the electrolyte membrane 40 of the assembly 90. This prevents the membrane electrode assembly 30 (FIG. 5) from shifting in position in a direction perpendicular to the guide rod 102. A protective sheet member 48 (FIG. 5) is joined to the membrane electrode assembly 30. This also prevents the protective sheet member 48 from shifting in position in a direction perpendicular to the guide rod 102.

[0060] The multiple-member stacking step S5 is a step of stacking multiple members on the assembly 90. Specifically, a pressure-resistant member 74 (FIG. 2), a second power supply member 44 (FIG. 2), a resin sheet 68 (FIG. 2), a conductive sheet 66 (FIG. 2), a leaf spring holder 62 (FIG. 2), a leaf spring 60 (FIG. 2), a cylindrical member 70 (FIG. 2), and a second separator 34 (FIG. 2) are stacked in this order. A guide rod 102 (FIG. 7) is inserted through each of these members.

[0061] When the multiple-component stacking step S5 is completed, one electrolytic cell 12 is manufactured. The guide rod 102 is removed after multiple electrolytic cells 12 are manufactured (stacked) by the above-described manufacturing method. Thereafter, as described above, the terminal plate 16b, the insulating plate 18b, and the end plate 20b are stacked in this order, and the end plates 20a, 20b are fastened together.

[0062] When the protective sheet member 48 is not joined to the membrane electrode assembly 30 at the joints 49, a restricting member is required to restrict misalignment of the protective sheet member 48 in a direction perpendicular to the guide rod 102 (the radial direction of the electrolysis cell 12). This is for the following reason: As shown in FIG. 2, the through-hole 48h (FIG. 2) of the protective sheet member 48 is larger than the through-hole 40h of the electrolyte membrane 40 to accommodate the sealing member 56a (FIG. 2). Therefore, before the end plates 20a, 20b are fastened together, a relatively large gap exists between the through-hole 48h (FIG. 2) of the protective sheet member 48 and the guide rod 102 inserted into the through-hole 48h. For this reason, when the protective sheet member 48 is not joined to the membrane electrode assembly 30 at the joints 49, a restricting member is required.

[0063] In contrast, in this embodiment, the protective sheet member 48 is joined to the membrane electrode assembly 30 at the joint 49 and then laminated on the fluid supply-side power feeder (first power feeder 42). There is a small gap between the through-hole 40h of the electrolyte membrane 40 of the membrane electrode assembly 30 and the guide rod 102 inserted into the through-hole 40h. Therefore, the guide rod 102 restricts the protective sheet member 48 from shifting in a direction perpendicular to the guide rod 102 via the membrane electrode assembly 30. Therefore, even without a dedicated restricting member for the protective sheet member 48, it is possible to restrict the positional displacement of the protective sheet member 48 in a direction perpendicular to the guide rod 102. This reduces the risk of misalignment during the manufacture of the electrolysis cell 12.

[0064] 3, the joint 49 is located away from the boundary position P1 between the central portion 48a and the frame portion 48b of the protective sheet member 48 and from the outer peripheral edge E1 of the frame portion 48b. Therefore, the bonding strength between the protective sheet member 48 and the membrane electrode assembly 30 can be increased compared to when the joint 49 is not located away from the boundary position P1 or the outer peripheral edge E1.

[0065] In this embodiment, the joints 49 are formed by welding, which makes it easier to join the protective sheet member 48 and the membrane electrode assembly 30 without distortion, compared to when the joints 49 are formed by adhesive or the like.

[0066] 5, when the joining portion 49 is formed in a ring shape surrounding the central portion 48a, the joining strength between the protective sheet member 48 and the membrane electrode assembly 30 can be increased. In this case, the joining portion 49 can be easily formed by welding.

[0067] The following additional notes are further disclosed regarding the above embodiment.

[0068] (Appendix 1) A method for manufacturing an electrolysis cell (12) according to the present disclosure includes a membrane electrode assembly (30) including an electrolyte membrane (40) having through holes (40h) formed therein, and a pair of electrode catalyst layers (42a, 44a) provided on both sides of the electrolyte membrane and covering a region of the electrolyte membrane between the peripheral edge region of the through holes and the outer peripheral edge region thereof, a pair of power feeders (42, 44) arranged on both sides of the membrane electrode assembly, and a protective sheet member (48) provided between one of the pair of power feeders and the membrane electrode assembly, wherein one of the pair of power feeders is a fluid supply side power feeder to which a fluid used for electrolysis is supplied. a protective sheet member having a central portion (48a) facing a covered portion (40a) of the electrolyte membrane that is covered with the electrode catalyst layer, and a frame portion (48b) located outside the central portion, the method comprising: a joining step (S1) of joining the frame portion and a portion of the electrolyte membrane-electrode structure that is located outside the covered portion to form a joint portion (49); and an assembly lamination step (S4) of laminating the joined electrolyte membrane-electrode structure and protective sheet member on the fluid supply-side power supply member with the protective sheet member facing the fluid supply-side power supply member.

[0069] (Appendix 2) In the method for manufacturing an electrolytic cell according to Supplementary Note 1, the joint may be spaced apart from a boundary position (P1) between the central portion and the frame portion and from an outer peripheral edge (E1) of the frame portion.

[0070] (Appendix 3) In the method for manufacturing an electrolytic cell according to Supplementary Note 1, the bonding portion may be provided in plurality at intervals in the circumferential direction of the protective sheet member.

[0071] (Appendix 4) In the method for manufacturing an electrolysis cell according to Supplementary Note 1, the joint may be formed by welding.

[0072] (Appendix 5) In the method for manufacturing an electrolysis cell according to Supplementary Note 4, the joint may be formed in a ring shape surrounding the central portion.

[0073] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments. [Explanation of symbols]

[0074] 12...Electrolytic cell 30...Electrolyte membrane-electrode assembly 40...electrolyte membrane 40a...covering portion 42...First power feeder (power feeder: fluid supply side power feeder) 42a...First electrode catalyst layer (electrode catalyst layer) 44...Second power supply body 44a... second electrode catalyst layer (electrode catalyst layer) 48... protective sheet member 48a...Central part 48b...Frame part 49…Joint part

Claims

1. an electrolyte membrane electrode assembly including an electrolyte membrane having through holes formed therein, and a pair of electrode catalyst layers provided on both sides of the electrolyte membrane and covering a region of the electrolyte membrane between a peripheral portion of the through hole and an outer peripheral portion thereof; a pair of power feeders disposed on both sides of the membrane electrode assembly; a protective sheet member provided between one of the pair of power feeders and the membrane electrode assembly; Equipped with one of the pair of power feeders is a fluid supply side power feeder to which a fluid used for electrolysis is supplied, a method for manufacturing an electrolysis cell, wherein the protective sheet member is configured by a central portion facing a covered portion of the electrolyte membrane that is covered with the electrode catalyst layer, and a frame portion that is located outside the central portion, a joining step of joining the frame to a portion of the membrane electrode assembly outside the covering portion to form a joint; an assembly laminating step of laminating the joined membrane electrode assembly and the protective sheet member onto the fluid supply side power feeder in a state where the protective sheet member faces the fluid supply side power feeder; A method for manufacturing an electrolysis cell, comprising:

2. 2. A method for producing the electrolytic cell of claim 1, comprising: A method for manufacturing an electrolytic cell, wherein the joint is spaced apart from the boundary between the central portion and the frame portion and from the outer peripheral edge of the frame portion.

3. 2. A method for producing the electrolytic cell of claim 1, comprising: A method for manufacturing an electrolytic cell, wherein the joints are provided at intervals in the circumferential direction of the protective sheet member.

4. 2. A method for producing the electrolytic cell of claim 1, comprising: The method for manufacturing an electrolytic cell, wherein the joint is formed by welding.

5. 5. A method for producing an electrolytic cell according to claim 4, comprising the steps of: A method for manufacturing an electrolytic cell, wherein the joint portion is formed in a ring shape surrounding the central portion.

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