Method for manufacturing electrolytic cell and method for manufacturing electrolytic device

Abstract

To provide a method for producing an electrolysis cell and a method for producing an electrolysis apparatus capable of improving assembly workability of the electrolysis cell.SOLUTION: The present disclosure provides a method for producing an electrolysis cell which comprises a first separator, a second separator, an ion exchange membrane, a negative electrode power feeding body, a negative electrode catalyst layer, a positive electrode power feeding body and a positive electrode catalyst layer. This production method comprises: a process in which the electrolysis cell is assembled such that the ion exchange membrane, the negative electrode power feeding body, the negative electrode catalyst layer, the positive electrode power feeding body and the positive electrode catalyst layer are sandwiched between the first separator and the second separator before the ion exchange membrane is immersed in an electrolyte solution; and a process in which after the electrolysis cell is assembled, an electrolyte solution is supplied into the electrolysis cell, and the ion exchange membrane is immersed in the electrolyte solution by storing the electrolysis cell or circulating the electrolyte solution for a predetermined period of time in a state where the electrolyte solution is present within the electrolysis cell.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a method for assembling a fuel cell stack in which a membrane electrode assembly or another separator is temporarily attached with an adhesive material applied to one separator, the adhesive material is then cured to form a seal line, and impurities are removed from the adhesive material. In this assembly method, water vapor is blown into the fuel cell as a pretreatment to dissolve and remove impurities from the adhesive material.

[0003] Patent Document 2 discloses a method for assembling a monopolar filter press type electrolytic cell, which includes the steps of assembling a vertical stack of horizontal electrode frames by disposing a horizontal thin membrane between each pair of opposing frames, preconditioning the vertical stack by passing a moist warm fluid through the stack, and applying pressure to opposite vertical ends of the stack so as to compress the vertical stack in the vertical direction.

[0004] Patent Document 3 discloses a method for assembling an electrolytic cell for an alkaline electrolyte, in which an ion exchange membrane is attached to an electrolytic cell, and then a 32 wt % aqueous sodium hydroxide solution is first supplied into the cathode chamber from the bottom of the cathode chamber, and then pure water is supplied into the cathode chamber from the bottom of the cathode chamber, and the pure water is supplied into the cathode chamber at a flow rate of 70 L / Hr or more per electrolytic cell, so that the cathode chamber is finally filled with an alkaline aqueous solution of 0.1 N or more and 6 N or less. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2017-174687 [Patent Document 2] Japanese Patent Publication No. 57-134583 [Patent Document 3] Patent No. 5833594 Summary of the Invention [Problem to be solved by the invention]

[0006] As a method for assembling an electrolytic cell for water electrolysis, a wet assembly process is recommended in which an ion exchange membrane is pre-treated by immersing it in an electrolytic solution, functional groups are substituted with hydroxide ions, and then the ion exchange membrane is incorporated into the electrolytic cell.

[0007] However, when wet assembly is performed, it is difficult to handle the ion exchange membrane wet with the electrolyte, and it takes time to adjust the installation position of the ion exchange membrane. It is also difficult to improve the accuracy of the installation position of the ion exchange membrane. These problems become more pronounced when multiple ion exchange membranes are handled, such as in an electrolysis cell stack.

[0008] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a method for manufacturing an electrolytic cell and a method for manufacturing an electrolytic device that can improve the assembly workability of the electrolytic cell. [Means for solving the problem]

[0009] In order to solve the above problems, the present disclosure provides a method for manufacturing an electrolytic cell, the method comprising: a first separator; a second separator; and a separator disposed between the first separator and the second separator. Anion exchange membranean ion exchange membrane, a cathode current supplier disposed between the first separator and the ion exchange membrane, a cathode catalyst layer disposed between the cathode current supplier and the ion exchange membrane, an anode current supplier disposed between the second separator and the ion exchange membrane, and an anode catalyst layer disposed between the anode current supplier and the ion exchange membrane, wherein the manufacturing method includes assembling the electrolytic cell such that the ion exchange membrane, the cathode current supplier, the cathode catalyst layer, the anode current supplier, and the anode catalyst layer are sandwiched between the first separator and the second separator before the ion exchange membrane is immersed in an electrolytic solution, and after assembling the electrolytic cell, It is an alkaline aqueous solution An electrolytic solution is supplied, and the electrolytic solution is left in the electrolytic cell for a predetermined time. Before The method includes circulating the electrolyte solution to immerse the ion exchange membrane in the electrolyte solution. The immersion of the ion exchange membrane in the electrolyte solution includes heating the electrolytic cell with the electrolyte solution present inside the electrolytic cell, and maintaining the temperature at 60°C or higher and lower than 100°C, which is the same temperature range as the operating temperature range of the electrolytic cell. In front The electrolyte is circulated and replacing the chloride ions contained in the ion exchange membrane with hydroxide ions. Includes:

[0010] The method for manufacturing an electrolysis device according to the present disclosure is a method for manufacturing an electrolysis device including a plurality of electrolysis cells, each of the plurality of electrolysis cells including a first separator, a second separator, and a separator disposed between the first separator and the second separator. Anion exchange membrane an ion exchange membrane, a cathode current supplier disposed between the first separator and the ion exchange membrane, a cathode catalyst layer disposed between the cathode current supplier and the ion exchange membrane, an anode current supplier disposed between the second separator and the ion exchange membrane, and an anode catalyst layer disposed between the anode current supplier and the ion exchange membrane, wherein the manufacturing method includes assembling the electrolytic cell such that the ion exchange membrane, the cathode current supplier, the cathode catalyst layer, the anode current supplier, and the anode catalyst layer are sandwiched between the first separator and the second separator before the ion exchange membrane is immersed in an electrolytic solution, and after assembling the electrolytic cell, It is an alkaline aqueous solutionAn electrolytic solution is supplied, and the electrolytic solution is left in the electrolytic cell for a predetermined time. Before The method includes circulating the electrolyte solution to immerse the ion exchange membrane in the electrolyte solution. The immersion of the ion exchange membrane in the electrolyte solution includes heating the electrolytic cell with the electrolyte solution present inside the electrolytic cell, and maintaining the temperature at 60°C or higher and lower than 100°C, which is the same temperature range as the operating temperature range of the electrolytic cell. In front The electrolyte is circulated and replacing the chloride ions contained in the ion exchange membrane with hydroxide ions. Includes: [Effects of the Invention]

[0011] According to the method for manufacturing an electrolytic cell and a method for manufacturing an electrolytic device of the present disclosure, it is possible to provide a method for manufacturing an electrolytic cell and a method for manufacturing an electrolytic device that can improve the assembly workability of the electrolytic cell. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing the configuration of an electrolysis device according to a first embodiment of the present disclosure. [Figure 2] FIG. 1 is a cross-sectional view schematically illustrating an electrolysis cell according to a first embodiment of the present disclosure. [Figure 3] FIG. 1 is an exploded perspective view showing an electrolysis cell according to a first embodiment of the present disclosure. [Figure 4] FIG. 1 is a cross-sectional view showing an electrolysis cell according to a first embodiment of the present disclosure. [Figure 5] FIG. 2 is a cross-sectional view illustrating a method for manufacturing the electrolysis cell according to the first embodiment of the present disclosure. [Figure 6] 1A to 1C are diagrams illustrating a method for manufacturing an electrolysis cell according to a first example of a first embodiment of the present disclosure. [Figure 7] 10A to 10C are diagrams illustrating a method for manufacturing an electrolysis cell according to a second example of the first embodiment of the present disclosure. [Figure 8] FIG. 2 is a diagram for explaining the effects of the electrolysis device according to the first embodiment of the present disclosure. [Figure 9] FIG. 4 is a diagram showing the configuration of an electrolysis device according to a second embodiment of the present disclosure. [Figure 10]FIG. 10 is a diagram showing the configuration of an electrolysis device according to a first modified example of the second embodiment of the present disclosure. [Figure 11] FIG. 10 is a diagram showing the configuration of an electrolysis device according to a second modified example of the second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a method for manufacturing an electrolytic cell and a method for manufacturing an electrolytic device according to an embodiment of the present disclosure will be described with reference to the drawings. In the following description, components having the same or similar functions will be denoted by the same reference numerals. In this disclosure, "facing" means that two components overlap when viewed from a certain direction, and may also include the case where another component exists between the two components.

[0014] First, referring to Figure 4, the Z direction, X direction, and Y direction will be defined. The Z direction is the direction from a first separator 41 to a second separator 42, which will be described later. The X direction is a direction that intersects (for example, is perpendicular to) the Z direction and is the direction from a center C of an ion exchange membrane 51, which will be described later, to one end of the ion exchange membrane 51. The Y direction is a direction that intersects (for example, is perpendicular to) the Z direction and the X direction and is, for example, the direction into the paper in Figure 4.

[0015] (First embodiment) <1. Configuration of electrolysis device> FIG. 1 is a diagram showing the configuration of an electrolysis device 1 according to a first embodiment. The electrolysis device 1 is, for example, a device that generates hydrogen by electrolyzing water contained in an electrolyte solution. The electrolysis device 1 is, for example, an anion exchange membrane (AEM) type electrolysis device. However, the electrolysis device 1 is not limited to the above example, and may be a different type of electrolysis device, such as a polymer electrolyte membrane (PEM) electrolysis device using a cation exchange membrane, or an electrolysis device that electrolytically reduces carbon dioxide.

[0016] The electrolysis device 1 includes, for example, an electrolysis cell stack 10, an electrolyte supply unit 20, a power supply unit 30, and a heating device 35.

[0017] (Electrolysis cell stack) The electrolysis cell stack 10 is an assembly of multiple electrolysis cells 11. For example, the electrolysis cell stack 10 is formed by arranging multiple electrolysis cells 11 in one direction and fastening the multiple electrolysis cells 11 together. Each electrolysis cell 11 includes a cathode chamber Sa and an anode chamber Sb. The electrolysis cells 11 will be described in detail below.

[0018] (Electrolyte supply section) The electrolyte supply unit 20 is a supply unit that supplies an electrolyte to each electrolytic cell 11. The electrolyte is, for example, pure water or an alkaline aqueous solution. In this embodiment, for example, an aqueous potassium hydroxide (KOH) solution with a concentration adjusted to 1 mol / L is used as the electrolyte. The electrolyte supply unit 20 includes a cathode-side supply unit 20a and an anode-side supply unit 20b.

[0019] The cathode-side supply unit 20a is a supply unit that supplies the electrolytic solution to the cathode chamber Sa of each electrolytic cell 11. The cathode-side supply unit 20a includes, for example, a hydrogen-gas-liquid separator 21, a first pump 22, a hydrogen recovery unit 23, a first electrolytic solution supply unit 24, and piping lines L1 and L2. In this embodiment, the piping lines L1 and L2 form a cathode-side circulation line La that circulates the electrolytic solution between the cathode chamber Sa of the electrolytic cell 11 and the hydrogen-gas-liquid separator 21.

[0020] The hydrogen-gas-liquid separator 21 stores the electrolytic solution. A supply port of the hydrogen-gas-liquid separator 21 is connected to the cathode chamber Sa of the electrolytic cell 11 via a piping line L1. A first pump 22 is provided midway along the piping line L1 and sends the electrolytic solution stored in the hydrogen-gas-liquid separator 21 toward the cathode chamber Sa of the electrolytic cell 11.

[0021] A return port of the hydrogen-gas-liquid separator 21 is connected to the cathode chamber Sa of the electrolytic cell 11 via a piping line L2. An electrolytic solution containing hydrogen produced in the electrolytic cell 11 flows into the hydrogen-gas-liquid separator 21 from the electrolytic cell 11. The hydrogen-gas-liquid separator 21 has a gas-liquid separation unit that separates the hydrogen contained in the electrolytic solution. The hydrogen separated from the electrolytic solution by the hydrogen-gas-liquid separator 21 is recovered by a hydrogen recovery unit 23. The hydrogen-gas-liquid separator 21 is replenished with electrolytic solution from a first electrolytic solution supply unit 24.

[0022] On the other hand, the anode-side supply unit 20b is a supply unit that supplies the electrolytic solution to the anode chamber Sb of each electrolytic cell 11. The anode-side supply unit 20b includes, for example, an oxygen-gas-liquid separator 26, a second pump 27, an oxygen recovery unit 28, a second electrolytic solution supply unit 29, and piping lines L3 and L4. In this embodiment, the piping lines L3 and L4 form an anode-side circulation line Lb that circulates the electrolytic solution between the anode chamber Sb of the electrolytic cell 11 and the oxygen-gas-liquid separator 26.

[0023] The oxygen-gas-liquid separator 26 stores the electrolyte. A supply port of the oxygen-gas-liquid separator 26 is connected to the anode chamber Sb of the electrolytic cell 11 via a piping line L3. A second pump 27 is provided in the piping line L3 and sends the electrolyte stored in the oxygen-gas-liquid separator 26 toward the anode chamber Sb of the electrolytic cell 11.

[0024] A return port of the oxygen-gas-liquid separator 26 is connected to the anode chamber Sb of the electrolytic cell 11 via a piping line L4. The electrolyte containing oxygen produced in the electrolytic cell 11 flows from the electrolytic cell 11 into the oxygen-gas-liquid separator 26. The oxygen-gas-liquid separator 26 has a gas-liquid separation unit that separates the oxygen contained in the electrolyte. The oxygen separated from the electrolyte by the oxygen-gas-liquid separator 26 is recovered by an oxygen recovery unit 28. The oxygen-gas-liquid separator 26 is replenished with electrolyte from a second electrolyte supply unit 29.

[0025] (Power supply part) The power supply unit 30 is a DC power supply device that applies a voltage to the electrolytic cell 11. The power supply unit 30 applies a DC voltage required for electrolysis of the electrolyte between the anode and cathode of the electrolytic cell 11.

[0026] (heating device) The heating device 35 heats the electrolysis cell 11 to an operating temperature suitable for electrolysis of the electrolyte. The heating device 35 is, for example, a heater attached to the electrolysis cell stack 10. The heating device 35 heats the electrolysis cell 11 to a predetermined operating temperature, for example, not lower than 60°C and not higher than 100°C, at least during normal operation of the electrolysis device 1. In the present disclosure, "normal operation" refers to a state in which a voltage is applied to the first separator 41 and the second separator 42, and hydrogen and oxygen are produced inside the electrolysis cell 11.

[0027] <2. Electrolysis cell configuration> 2.1 Basic structure of electrolysis cell Next, the electrolytic cell 11 will be described in detail. 2 is a cross-sectional view schematically illustrating the electrolysis cell 11. The electrolysis cell 11 includes, for example, a first separator 41, a second separator 42, a cathode current collector 43, an anode current collector 44, and a membrane electrode assembly 45.

[0028] (First separator) The first separator 41 is a member that defines one side of the internal space S of the electrolysis cell 11. The internal space S is a space that includes a cathode chamber Sa and an anode chamber Sb, which will be described later. The first separator 41 is, for example, in the shape of a rectangular plate, and is formed of a conductive material such as a metal member or graphite. A negative voltage is applied to the first separator 41 from the power supply unit 30, for example, via a first current collector 63 (see FIG. 3), which will be described later.

[0029] The first separator 41 has a first end 41e1 (e.g., a lower end) and a second end 41e2 (e.g., an upper end) located opposite the first end 41e1. The piping line L1 described above is connected to the first end 41e1 of the first separator 41. The piping line L2 described above is connected to the second end 41e2 of the first separator 41. The first separator 41 has a first inner surface 41a facing the cathode chamber Sa described below. The first inner surface 41a is formed with a first flow path FP1 through which the electrolytic solution supplied from the piping line L1 flows. The first flow path FP1 is, for example, a groove provided in the first inner surface 41a. The electrolytic solution that has flowed through the first flow path FP1 is discharged to the outside of the electrolytic cell 11 through the piping line L2. Note that the structures (e.g., flow path structure, etc.) shown in FIG. 2 are merely examples and do not limit the content of this embodiment. For example, various flow path structures can be used depending on the size, purpose, and usage environment of the device. This also applies to the structures shown in the other figures.

[0030] (Second separator) The second separator 42 is disposed with an internal space S between it and at least a part of the first separator 41, and is a member that defines the other side of the internal space S. The second separator 42 is, for example, a rectangular plate and is made of a metal member. A positive voltage is applied to the second separator 42 from the power supply unit 30 via a second current collector 64 (see FIG. 3 ), which will be described later.

[0031] The second separator 42 has a first end 42e1 (e.g., a lower end) and a second end 42e2 (e.g., an upper end) located opposite the first end 42e1. The above-mentioned piping line L3 is connected to the first end 42e1 of the second separator 42. The above-mentioned piping line L4 is connected to the second end 42e2 of the second separator 42. The second separator 42 has a second inner surface 42a facing the anode chamber Sb, which will be described later. A second flow path FP2 is formed on the second inner surface 42a, through which the electrolytic solution supplied from the piping line L3 flows. The second flow path FP2 is, for example, a groove provided in the second inner surface 42a. The electrolytic solution that has flowed through the second flow path FP2 is discharged to the outside of the electrolytic cell 11 through the piping line L4.

[0032] For ease of explanation, the configuration described here is one in which a flow path groove (first flow path FP1) is provided on the first inner surface 41a of the first separator 41, and a flow path groove (second flow path FP2) is provided on the second inner surface 42a of the second separator 42. However, for example, the first separator 41 of the electrolysis cell 11 included in the electrolysis cell stack 10 (see FIG. 1 ) may be a bipolar plate having a similar flow path groove (first flow path FP1, shown by a two-dot chain line in FIG. 2 ) on the surface 41b opposite the first inner surface 41a in addition to the first inner surface 41a. Furthermore, the second separator 42 of the electrolysis cell 11 included in the electrolysis cell stack 10 may be a bipolar plate having a similar flow path groove (second flow path FP2, shown by a two-dot chain line in FIG. 2 ) on the surface 42b opposite the second inner surface 42a in addition to the second inner surface 42a. That is, each of the first separator 41 and the second separator 42 may be shared by multiple electrolysis cells 11. The flow path grooves provided on both sides of the first separator 41 may have different shapes and arrangements. The flow path grooves provided on both sides of the second separator 42 may have different shapes and arrangements.

[0033] (Cathode feeder) The cathode power supply 43 is an electrical connection that transmits the voltage applied to the first separator 41 to the cathode catalyst layer 52. The cathode power supply 43 is disposed between the first separator 41 and the membrane electrode assembly 45, and is located in the cathode chamber Sa. The cathode power supply 43 is located between the first inner surface 41a of the first separator 41 and the cathode catalyst layer 52, and is in contact with the first inner surface 41a of the first separator 41 and the cathode catalyst layer 52, respectively. The cathode power supply 43 has a structure that allows electrolyte and gas to pass through. The cathode power supply 43 is formed, for example, from a metal mesh structure, a sintered body, or fiber. The outer size of the cathode power supply 43 is, for example, the same as the outer size of the cathode catalyst layer 52. In this embodiment, the cathode power supply 43 and the cathode catalyst layer 52 form the cathode 47 of the battery cell 11.

[0034] (anode current collector) The anode power supply 44 is an electrical connection that transmits the voltage applied to the second separator 42 to the anode catalyst layer 53. The anode power supply 44 is disposed between the second separator 42 and the membrane electrode assembly 45, and is located in the anode chamber Sb. The anode power supply 44 is located between the second inner surface 42a of the second separator 42 and the anode catalyst layer 53, and is in contact with the second inner surface 42a of the second separator 42 and the anode catalyst layer 53, respectively. The anode power supply 44 has a structure that allows electrolyte and gas to pass through. The anode power supply 44 is formed, for example, from a metal mesh structure, sintered body, or fiber. The external size of the anode power supply 44 is, for example, the same as the external size of the anode catalyst layer 53. In this embodiment, the anode power supply 44 and the anode catalyst layer 53 form the anode 48 of the battery cell 11.

[0035] (Membrane electrode assembly) The membrane electrode assembly (MEA) 45 is a structure in which an ion exchange membrane and a catalyst are assembled. The membrane electrode assembly 45 is disposed between a first separator 41 and a second separator 42, and is located in the internal space S. The membrane electrode assembly 45 includes, for example, an ion exchange membrane 51, a cathode catalyst layer 52, and an anode catalyst layer 53.

[0036] (ion exchange membrane) The ion exchange membrane 51 is a membrane that selectively allows ions to pass through. The ion exchange membrane 51 is, for example, a solid polymer electrolyte membrane. The ion exchange membrane 51 is, for example, an anion exchange membrane (AEM) that is hydroxide ion conductive. However, the ion exchange membrane 51 is not limited to the above example and may be a type of ion exchange membrane different from the above example. The ion exchange membrane 51 is, for example, in the form of a rectangular sheet. The ion exchange membrane 51 is disposed between the first separator 41 and the second separator 42 and is located in the internal space S described above. The ion exchange membrane 51 has a first surface 51a facing the first inner surface 41a of the first separator 41 and a second surface 51b facing the second inner surface 42a of the second separator 42, located on the opposite side from the first surface 51a. A cathode chamber Sa is defined between the first surface 51a of the ion exchange membrane 51 and the first inner surface 41a of the first separator 41. Between the second surface 51b of the ion exchange membrane 51 and the second inner surface 42a of the second separator 42, an anode chamber Sb is defined.

[0037] When a voltage is applied to the electrolytic cell 11 in the cathode chamber Sa, the following chemical reaction occurs, producing hydrogen from the electrolytic solution. Note that in this application, the phrase "XX is produced" may also include cases where other substances are produced simultaneously with the production of XX. The hydroxide ions produced in the cathode chamber Sa pass through the ion exchange membrane 51 and move from the cathode chamber Sa to the anode chamber Sb. 2H2O+2e - →H2+2OH - …(C1)

[0038] In the anode chamber Sb, when a voltage is applied to the electrolytic cell 11, the following chemical reaction occurs, producing oxygen from the electrolyte. 2OH - →1 / 2O2+H2O+2e - …(Case 2)

[0039] As a result, the following chemical reactions occur in the electrolysis cell 11 as a whole. H2O→H2+1 / 2O2…(Chem.3)

[0040] (Cathode catalyst layer) The cathode catalyst layer 52 is a layer that promotes the chemical reaction in the cathode chamber Sa described above. The cathode catalyst layer 52 is, for example, a rectangular sheet. In this embodiment, the outer size of the cathode catalyst layer 52 is the same as that of the cathode power supply 43. However, the outer size of the cathode catalyst layer 52 may be the same as or smaller than that of the ion exchange membrane 51. The cathode catalyst layer 52 is disposed between the cathode power supply 43 and the ion exchange membrane 51. The cathode catalyst layer 52 is adjacent to the ion exchange membrane 51. Note that in this application, "adjacent" is not limited to two components being adjacent to each other independently, but may also include a case where at least a portion of one of the two components penetrates into the other. For example, a portion of the cathode catalyst layer 52 may penetrate into the surface of the ion exchange membrane 51.

[0041] In this embodiment, the cathode catalyst layer 52 is provided on the first surface 51a of the ion exchange membrane 51. For example, the cathode catalyst layer 52 is formed by applying a material for the cathode catalyst layer 52 to the first surface 51a of the ion exchange membrane 51. A negative voltage is applied to the cathode catalyst layer 52 from the power supply unit 30 via the first separator 41 and the cathode power supply 43, and the cathode catalyst layer 52 functions as part of the cathode 47 of the battery cell 11.

[0042] The cathode catalyst layer 52 may be made of any material that promotes the chemical reaction in the cathode chamber Sa. For example, the cathode catalyst layer 52 may contain one or more of nickel, nickel alloy, cerium oxide, lanthanum oxide, or platinum. In this disclosure, "XX oxide" may include other materials in addition to XX and oxygen. The cathode catalyst layer 52 may also include other materials, such as carbon, in addition to the above-mentioned materials. "XX" is any material.

[0043] (Anode catalyst layer) The anode catalyst layer 53 is a layer that promotes the chemical reaction in the anode chamber Sb. The anode catalyst layer 53 is, for example, a rectangular sheet. In this embodiment, the outer size of the anode catalyst layer 53 is the same as that of the anode power supply 44. However, the outer size of the anode catalyst layer 53 may be the same as or smaller than that of the ion exchange membrane 51. The anode catalyst layer 53 is disposed between the anode power supply 44 and the ion exchange membrane 51. The anode catalyst layer 53 is adjacent to the ion exchange membrane 51. Note that, for example, a portion of the anode catalyst layer 53 may extend into the surface portion of the ion exchange membrane 51. In this embodiment, the anode catalyst layer 53 is provided on the second surface 51b of the ion exchange membrane 51. For example, the anode catalyst layer 53 is formed by applying a material for the anode catalyst layer 53 to the second surface 51b of the ion exchange membrane 51. A positive voltage is applied to the anode catalyst layer 53 from the power supply unit 30 via the second separator 42 and the anode power supply 44 , and the anode catalyst layer 53 functions as part of the anode 48 of the battery cell 11 .

[0044] The anode catalyst layer 53 may be made of any material that promotes the chemical reaction in the anode chamber Sb. For example, the anode catalyst layer 53 may contain one or more of nickel, nickel alloy, nickel oxide, copper oxide, iridium oxide, niobium oxide, lead oxide, or bismuth oxide. As described above, in this disclosure, "XX oxide" may contain other materials in addition to XX and oxygen. For example, "nickel oxide" may contain other materials such as iron or cobalt in addition to nickel and oxygen. "Copper oxide" may contain other materials such as cobalt in addition to copper and oxygen. "Iridium oxide" may contain other materials such as ruthenium in addition to iridium and oxygen. "Lead oxide" may contain other materials such as ruthenium in addition to lead and oxygen. "Bismuth oxide" may contain other materials such as ruthenium in addition to bismuth and oxygen.

[0045] (Other configurations of electrolysis cells) Next, other configurations of the electrolysis cell 11 will be described. 3 is an exploded perspective view showing an electrolysis cell 11. In addition to the components described above, the electrolysis cell 11 includes, for example, a first insulator 61, a second insulator 62, a first current collector 63, a second current collector 64, a third insulator 65, a fourth insulator 66, a first end plate 67, a second end plate 68, and a plurality of fastening members 69. Note that the first current collector 63, the second current collector 64, the third insulator 65, the fourth insulator 66, the first end plate 67, the second end plate 68, and the plurality of fastening members 69 may be shared by a plurality of electrolysis cells 11 included in the electrolysis cell stack 10. Furthermore, these components may be provided as part of the electrolysis cell 11 or as part of the electrolysis cell stack 10.

[0046] (first insulator) The first insulator 61 is a member that provides insulation between the outer periphery of the first separator 41 and the outer periphery of the second separator 42. The first insulator 61 is a frame-shaped sheet member that is slightly larger than the outer shape of the cathode power supply 43. The first insulator 61 is attached to the first inner surface 41a of the first separator 41 and covers the end of the first inner surface 41a. The material of the first insulator 61 is not particularly limited as long as it is an insulating material, and is, for example, a sheet-shaped resin such as PTFE (polytetrafluoroethylene).

[0047] (Second insulator) Similar to the first insulator 61, the second insulator 62 is a member that provides insulation between the outer periphery of the first separator 41 and the outer periphery of the second separator 42. The second insulator 62 is a frame-shaped sheet member that is slightly larger than the outer shape of the anode power supply 44. The second insulator 62 is attached to the second inner surface 42a of the second separator 42 and covers the end of the second inner surface 42a. The material of the second insulator 62 is not particularly limited as long as it is an insulating material, and is, for example, a sheet-shaped resin such as PTFE. The first insulator 61 and the second insulator 62 can also be used as an integrated insulator.

[0048] (First current collector) The first current collector 63 is an electrical connection part that transmits a negative voltage applied from the power supply unit 30 to the first separator 41. The first current collector 63 is a metal plate member (e.g., a copper plate). The first current collector 63 contacts the first separator 41 from the side opposite to the internal space S of the electrolysis cell 11, for example, and is electrically connected to the first separator 41. A negative voltage required for electrolysis in the electrolysis cell 11 is applied to the first current collector 63 from the power supply unit 30.

[0049] (Second current collector) The second current collector 64 is an electrical connection part that transmits the positive voltage applied from the power supply unit 30 to the second separator 42. The second current collector 64 is a metal plate member (e.g., a copper plate). The second current collector 64 contacts the second separator 42 from the side opposite to the internal space S of the electrolysis cell 11, for example, and is electrically connected to the second separator 42. The positive voltage required for electrolysis in the electrolysis cell 11 is applied to the second current collector 64 from the power supply unit 30.

[0050] (third insulator) The third insulator 65 is located between the first current collector 63 and the first end plate 67. The external size of the third insulator 65 is, for example, larger than the external size of the first current collector 63. The third insulator 65 has, for example, a recess that accommodates at least a portion of the first current collector 63. The third insulator 65 has a plurality of holes 65a through which fastening members 69, described later, are passed.

[0051] (fourth insulator) The fourth insulator 66 is located between the second current collector 64 and the second end plate 68. The outer size of the fourth insulator 66 is, for example, larger than the outer size of the second current collector 64. The fourth insulator 66 has, for example, a recess that accommodates at least a portion of the second current collector 64. The fourth insulator 66 has a plurality of holes 66a through which fastening members 69, described later, are passed.

[0052] (First end plate) The first end plate 67 is located on the opposite side of the third insulator 65 with respect to the internal space S of the electrolysis cell 11. The outer size of the first end plate 67 is, for example, the same as or larger than the outer size of the third insulator 65. The first end plate 67 has a plurality of holes 67a through which fastening members 69, which will be described later, are passed.

[0053] (Second end plate) The second end plate 68 is located on the opposite side of the internal space S of the electrolysis cell 11 from the fourth insulator 66. The outer size of the second end plate 68 is, for example, the same as or larger than the outer size of the fourth insulator 66. The second end plate 68 has a plurality of holes 68a through which fastening members 69, which will be described later, are passed.

[0054] (Fastening member) The fastening member 69 is a fastening member that presses the first separator 41 and the second separator 42 in a direction that brings them closer to each other, thereby integrating the electrolysis cell 11 with the cathode current collector 43, the anode current collector 44, and the membrane electrode assembly 45 sandwiched between the first separator 41 and the second separator 42.

[0055] The fastening members 69 include, for example, bolts 69a and nuts 69b. The bolts 69a are passed from the outside of the first end plate 67 through holes 67a in the first end plate 67, holes 65a in the third insulator 65, holes 66a in the fourth insulator 66, and holes 68a in the second end plate 68. The nuts 69b engage with the tips of the bolts 69a on the outside of the second end plate 68. In this embodiment, the fastening members 69 apply a fastening force between the first end plate 67 and the second end plate 68, thereby pressing the first separator 41 and the second separator 42 in a direction that brings them closer to each other, thereby integrating the electrolysis cell 11. Note that the fastening structure for integrating the electrolysis cell 11 is not limited to the above example, and various structures can be adopted.

[0056] The electrolysis cell 11 is not limited to the above-described configuration. For example, when multiple electrolysis cells 11 are arranged side by side in the electrolysis cell stack 10, two adjacent electrolysis cells 11 among the multiple electrolysis cells 11 may share a first separator 41 or a second separator 42, which is a bipolar plate. In this case, there may not be a current collector (first current collector 63 or second current collector 64), an insulator (third insulator 65 or fourth insulator 66), or an end plate (first end plate 67 or second end plate 68) between the two adjacent electrolysis cells 11.

[0057] 2.2 Peripheral structure of electrolytic cell 4 is a cross-sectional view showing the electrolysis cell 11. The electrolysis cell 11 has, for example, a support 70. The support 70 is a member that supports the membrane electrode assembly 45 inside the electrolysis cell 11 and closes the internal space S between the first separator 41 and the second separator 42 in a liquid-tight manner.

[0058] The support 70 is disposed between the first separator 41 and the second separator 42. The support 70 is located inside (on the inner circumferential side) of the outer edge 51e of the ion exchange membrane 51 and supports the ion exchange membrane 51. In the present disclosure, the "outer edge" refers to an edge away from the central portion C of the ion exchange membrane 51 in a direction (e.g., the X direction or the Y direction) perpendicular to the thickness direction (Z direction) of the membrane electrode assembly 45. In addition, in the present disclosure, the "inside" or "inner circumferential side" refers to the inside (the side closer to the central portion C) when viewed from the central portion C of the ion exchange membrane 51. In the present embodiment, the support 70 includes, for example, a first support 71 and a second support 72.

[0059] (1st support part) The first support portion 71 is a support portion on the cathode side. The first support portion 71 is disposed between the first inner surface 41a of the first separator 41 and the first surface 51a of the ion exchange membrane 51. The first support portion 71 is located inside (on the inner circumferential side) of the outer edge portion 51e of the ion exchange membrane 51. The first support portion 71 is sandwiched between the first inner surface 41a of the first separator 41 (or the first insulator 61) and the first surface 51a of the ion exchange membrane 51 at a position outside (on the outer circumferential side) of the cathode power supply 43, and supports the ion exchange membrane 51 against the first inner surface 41a of the first separator 41. The first support portion 71 is formed in a ring shape (e.g., a frame shape) that follows the outer edge portion 51e of the ion exchange membrane 51 and is one size smaller than the outer edge portion 51e of the ion exchange membrane 51. The first support portion 71 is sandwiched between the first inner surface 41a of the first separator 41 (or the first insulator 61) and the first surface 51a of the ion exchange membrane 51, thereby liquid-tightly sealing the cathode chamber Sa from the outside.

[0060] (Second support part) The second support 72 is a support on the anode side. The second support 72 is disposed between the second inner surface 42a of the second separator 42 and the second surface 51b of the ion exchange membrane 51. The second support 72 is located inside (on the inner circumferential side) of the outer edge 51e of the ion exchange membrane 51. The second support 72 is sandwiched between the second inner surface 42a of the second separator 42 (or the second insulator 62) and the second surface 51b of the ion exchange membrane 51 at a position outside (on the outer circumferential side) of the anode power supply 44, and supports the ion exchange membrane 51 against the second inner surface 42a of the second separator 42. The second support 72 is annular (e.g., frame-shaped) along the outer edge 51e of the ion exchange membrane 51 and is formed into a ring shape slightly smaller than the outer edge 52e of the ion exchange membrane 51. The second support portion 72 is sandwiched between the second inner surface 42a of the second separator 42 (or the second insulator 62) and the second surface 51b of the ion exchange membrane 51, thereby liquid-tightly sealing the anode chamber Sb from the outside.

[0061] <3. Manufacturing method of electrolysis device> Next, a method for manufacturing the electrolysis device 1 will be described. In the electrolysis device 1 of this embodiment, the electrolysis cell 11 is assembled before the ion effect membrane 51 is immersed in the electrolyte, the electrolyte is supplied into the electrolysis cell 11 after assembly, and the electrolysis cell 11 is stored or the electrolyte is circulated for a predetermined period of time while the electrolyte is present inside the electrolysis cell 11, thereby immersing the ion exchange membrane 51 in the electrolyte. A method for producing such an electrolysis device 1 will be described in detail below.

[0062] 5A and 5B are cross-sectional views illustrating a method for manufacturing the electrolysis cell 11. First, as shown in (a) of Fig. 5A, a cathode catalyst layer 52 and an anode catalyst layer 53 are provided on the ion exchange membrane 51 before the ion exchange membrane 51 is immersed in the electrolytic solution (in a dry state), thereby forming a membrane electrode assembly 45. For example, the membrane electrode assembly 45 is formed by applying the material for the cathode catalyst layer 52 to a first surface 51a of the ion exchange membrane 51 and applying the material for the anode catalyst layer 53 to a second surface 51b of the ion exchange membrane 51.

[0063] Next, as shown in FIG. 5(b), before the ion exchange membrane 51 is immersed in the electrolyte (in a dry state), the cathode power supply 43, the anode power supply 44, the membrane electrode assembly 45, the first insulator 61, the second insulator 62, the first support 71, and the second support 72 are sandwiched between the first separator 41 and the second separator 42. The cathode power supply 43 may be bonded to the first separator 41 or the membrane electrode assembly 45 in advance and stabilized before being sandwiched between the first separator 41 and the second separator 42. Similarly, the anode power supply 44 may be bonded to the second separator 42 or the membrane electrode assembly 45 in advance and integrated before being sandwiched between the first separator 41 and the second separator 42.

[0064] Next, as shown in FIG. 5(c), with the cathode power supply 43, the anode power supply 44, the membrane electrode assembly 45, the first insulator 61, the second insulator 62, the first support 71, and the second support 72 sandwiched between the first separator 41 and the second separator 42, a fastening operation is performed using fastening members 69 to press the first separator 41 and the second separator 42 toward each other. This assembles the electrolysis cell 11 in a state (dry state) before the ion exchange membrane 51 is immersed in the electrolytic solution. Note that in this embodiment, the above-described operations (a) to (c) in FIG. 5 are performed simultaneously for the multiple electrolysis cells 11 included in the electrolysis cell stack 10.

[0065] Next, as shown in (d) of FIG. 5, after the electrolytic cell stack 10 is assembled, an electrolyte is supplied into each electrolytic cell 11, and the cathode chamber Sa and the anode chamber Sb are filled with the electrolyte. This causes the ion exchange membrane 51 inside each electrolytic cell 11 to come into contact with the electrolyte and become ready for immersion. In this state, the electrolytic cell stack 10 is stored or the electrolyte is circulated, thereby immersing the ion exchange membrane 51 in the electrolyte. That is, a sufficient amount of electrolyte is absorbed into the ion exchange membrane 51, and functional group substitution with hydroxide ions is performed.

[0066] <4. Example of manufacturing method of electrolysis device> Two examples of the method for manufacturing the electrolysis device 1 will be described below.

[0067] 4.1 First Example 6 is a diagram showing a manufacturing method of the electrolysis device 1 of the first embodiment. The first embodiment is an example in which the electrolytic solution used for immersing the ion exchange membrane 51 is not discharged from the electrolysis device 1, but at least a part (for example, all) of the electrolytic solution used for immersion is used as is to start normal operation (water electrolysis treatment) of the electrolysis device 1.

[0068] First, as described with reference to (a) to (c) in FIG. 5, the electrolysis cell 11 is assembled so that the membrane electrode assembly 45, the cathode power supply 43, and the anode power supply 44 are sandwiched between the first separator 41 and the second separator 42 in a state (dry state) before the ion exchange membrane 51 is immersed in the electrolytic solution (S101). This operation is performed for a plurality of electrolysis cells 11, thereby assembling the electrolysis cell stack 10. In this embodiment, the electrolysis device 1 is assembled following the process of S101. That is, the various components included in the cathode side supply unit 20a and the anode side supply unit 20b are connected to the electrolysis cell stack 10.

[0069] Next, as described with reference to (d) in FIG. 5 , an electrolytic solution is supplied into each electrolytic cell 11, and the cathode chamber Sa and the anode chamber Sb are filled with the electrolytic solution (S102). This brings the ion exchange membrane 51 into contact with the electrolytic solution inside each electrolytic cell 11. In this embodiment, the electrolytic solution supplied into the electrolytic cell 11 in the process of S102 is an electrolytic solution adjusted to a predetermined concentration, for example, the same as the alkali concentration during normal operation of the electrolytic device 1 (e.g., 1 mol / L). In this embodiment, the process of S102 is performed using the cathode-side circulation line La and the anode-side circulation line Lb, which supply the electrolytic solution into the electrolytic cell 11 during normal operation, etc.

[0070] Next, with the predetermined concentration of the electrolyte solution present inside the electrolytic cell 11, the electrolyte solution is circulated for a predetermined time (e.g., 1 hour) (S103). In this embodiment, the electrolyte solution is circulated using the cathode-side circulation line La and the anode-side circulation line Lb. For example, the first pump 22 is driven to circulate the electrolyte solution between the cathode chamber Sa of the electrolytic cell 11 and the hydrogen-gas-liquid separator 21 using the cathode-side circulation line La. Similarly, the second pump 27 is driven to circulate the electrolyte solution between the anode chamber Sb of the electrolytic cell 11 and the oxygen-gas-liquid separator 26 using the anode-side circulation line Lb. This immerses the ion exchange membrane 51 in the electrolyte solution. That is, a sufficient amount of the electrolyte solution is absorbed into the ion exchange membrane 51, and functional group substitution with hydroxide ions is performed.

[0071] Next, the electrolytic cell 11 is heated using the heating device 35 (S104). In this embodiment, the heating device 35 heats the electrolytic cell 11 to the same operating temperature as that during normal operation of the electrolytic cell 11 (for example, a predetermined temperature of 60°C or higher and 100°C or lower). By heating the electrolytic cell 11, for example, chloride ions (Cl - ) and hydroxide ions (OH - In other words, since the diffusion rate of ion exchange is determined by the concentration difference and temperature, the temperature can be raised to increase the diffusion rate.

[0072] Thereafter, the electrolysis device 1 starts water electrolysis (S105). In this embodiment, while the circulation of the electrolytic solution by the first pump 22 and the second pump 27 and the heating by the heating device 35 are maintained from the process step of S104, the power supply unit 30 applies a voltage to the first separator 41 and the second separator 42, thereby starting the water electrolysis. That is, in this embodiment, the electrolytic solution is circulated to immerse the ion exchange membrane 51 in the electrolytic solution, and then the electrolytic solution used for immersion is used as is to start normal operation of the electrolytic cell 11.

[0073] In addition, instead of circulating the electrolyte as described above, the ion exchange membrane 51 may be immersed in the electrolyte by supplying the electrolyte (for example, the electrolyte having the above-mentioned predetermined concentration) to the inside of the electrolytic cell 11, and storing the electrolytic cell 11 as is for a predetermined period of time without circulating the electrolyte, in a state where the electrolyte is present inside the electrolytic cell 11.

[0074] Furthermore, heating the electrolytic cell 11 using the heating device 35 (the process of S104) may be performed simultaneously with circulating the electrolytic solution for the predetermined time (the process of S103). That is, immersing the ion exchange membrane 51 in the electrolytic solution may be performed by heating the electrolytic cell 11 while the electrolytic solution is present inside the electrolytic cell 11, and storing the electrolytic cell 11 or circulating the electrolytic solution while the electrolytic cell 11 is at a temperature higher than room temperature (for example, a predetermined temperature of 60°C or higher and 100°C or lower). Furthermore, heating the electrolytic cell 11 using the heating device 35 (the process of S104) may be performed before circulating the electrolytic solution for the predetermined time (the process of S103). The same applies to a second example described below.

[0075] <4.2 Second Example> 7 is a diagram showing a manufacturing method of the electrolysis device 1 of the second embodiment. The second embodiment is an example in which the electrolytic solution used for immersing the ion exchange membrane 51 is discharged to the outside of the electrolysis device 1, and then new electrolytic solution is supplied into the electrolytic cell 11, and operation of the electrolysis device 1 is started. Note that the processes of S101 to S105 are the same as those of the first embodiment, and therefore redundant explanations will be omitted.

[0076] In the second example, after the process of heating the electrolytic cell 11 using the heating device 35 (the process of S104), the electrolyte used to immerse the ion exchange membrane 51 is discharged to the outside of the electrolysis device 1 (S201). As a result, if impurities are eluted into the electrolyte due to the immersion of the ion exchange membrane 51, the electrolyte containing the impurities is discharged to the outside of the electrolysis device 1. Note that after the electrolyte used for immersion is discharged to the outside of the electrolysis device 1, the electrolysis device 1 may be washed with new electrolyte or pure water. An example of the impurities is chloride ions eluted from the ion exchange membrane 51. The elution of chloride ions will be described in detail in the second embodiment. However, the impurities eluted into the electrolyte are not limited to chloride ions, and other types of impurities may be used.

[0077] Next, fresh electrolyte is supplied to each electrolytic cell 11, and the cathode chamber Sa and the anode chamber Sb are filled with the electrolyte (S202). In this embodiment, the electrolyte supplied to the electrolytic cell 11 in the process of S202 is adjusted to a predetermined concentration, for example, the same as the alkali concentration during normal operation of the electrolytic device 1 (for example, 1 mol / L). The process of S202 is also performed, for example, using the cathode-side circulation line La and the anode-side circulation line Lb that supply the electrolyte to the electrolytic cell 11 during normal operation. Thereafter, circulation of the electrolyte is started while the electrolyte is present in the electrolytic cell 11. Circulation of the electrolyte is performed, for example, using the first pump 22 and the second pump 27. Thereafter, water electrolysis by the electrolytic device 1 is started (S105).

[0078] <5. Action and Effects> 8 is a diagram for explaining the effects of the electrolysis device 1 of the first embodiment, showing the results of an experiment conducted by the present inventors regarding the relationship between the current density and the cell voltage (IV characteristics) of the electrolysis cell 11. Note that the "cell voltage" refers to the voltage applied between the first separator 41 and the second separator 42 by the power supply unit 30.

[0079] 8 is an example in which the ion exchange membrane 51 is pretreated (the ion exchange membrane 51 is immersed in an electrolyte solution) before the electrolysis cell 11 is assembled. For example, the pretreatment is performed by immersing the ion exchange membrane 51 in an electrolyte solution whose concentration is adjusted to 0.5 mol / L for a predetermined time (e.g., 1 hour), then replacing the electrolyte solution used for the immersion, and immersing the ion exchange membrane 51 again in an electrolyte solution whose concentration is adjusted to 0.5 mol / L for a predetermined time (e.g., 1 hour). In the comparative example, the ion exchange membrane 51 is placed between the first separator 41 and the second separator 42 while wet with the electrolyte solution, and the electrolysis cell 11 is assembled.

[0080] The present inventors have confirmed that the electrolysis devices 1 manufactured by the manufacturing methods of the first and second examples described above can achieve electrical characteristics (e.g., IV characteristics) that are almost the same as those of the electrolysis device manufactured by the manufacturing method of the comparative example described above, as shown in Fig. 8. In other words, it has been confirmed that even when the electrolysis cell 11 is assembled with the ion exchange membrane 51 in a dry state, the electrical characteristics do not deteriorate when the electrolysis cell 11 is immersed after assembly.

[0081] From another perspective, the present inventors have confirmed that the electrolysis device 1 manufactured by the manufacturing method of Example 1 can obtain electrical characteristics (e.g., IV characteristics) that are almost the same as those of the electrolysis device 1 manufactured by the manufacturing method of Example 2. In other words, it has been confirmed that the electrical characteristics do not deteriorate even when the electrolytic solution used for immersing the ion exchange membrane 51 is used directly to perform water electrolysis.

[0082] <6. Advantages> As in the comparative example, when an ion exchange membrane is pretreated by immersing it in an electrolytic solution and functional groups are substituted with hydroxide ions before the ion exchange membrane is incorporated into an electrolytic cell, the ion exchange membrane that is wet with the electrolytic solution is difficult to handle, it takes time to adjust the installation position of the ion exchange membrane, and it is also difficult to improve the accuracy of the installation position of the ion exchange membrane. These problems become even more pronounced when multiple ion exchange membranes are handled, such as in an electrolytic cell stack.

[0083] Furthermore, when an ion exchange membrane is pretreated by immersing it in an electrolyte solution and then assembled into an electrolytic cell, a portion of the ion exchange membrane begins to dry out during assembly of the electrolytic cell, and if that portion comes into contact with the electrolyte solution again during use of the electrolytic cell, that portion will repeatedly dry out and swell, which may result in a shortened lifespan of the ion exchange membrane.

[0084] On the other hand, in the present embodiment, before the ion exchange membrane 51 is immersed in the electrolyte, the electrolytic cell 11 is assembled such that the ion exchange membrane 51, the cathode power supply 43, the cathode catalyst layer 52, the anode power supply 44, and the anode catalyst layer 53 are sandwiched between the first separator 41 and the second separator 42. After the electrolytic cell 11 is assembled, the electrolytic cell 11 is supplied with the electrolyte, and the electrolytic cell 11 is stored or circulated for a predetermined period of time while the electrolyte is present inside the electrolytic cell 11, thereby immersing the ion exchange membrane 51 in the electrolyte. With this configuration, the electrolytic cell 11 can be assembled while the ion exchange membrane 51 is dry. This makes the ion exchange membrane 51 easier to handle, reduces the time required to adjust the installation position of the ion exchange membrane 51, and increases the accuracy of the installation position of the ion exchange membrane 51. This improves the ease of assembly of the electrolytic cell 11.

[0085] Furthermore, assembling the electrolytic cell 11 before the ion exchange membrane 51 is immersed in the electrolytic solution can prevent a portion of the ion exchange membrane 51 from repeatedly drying and swelling, thereby preventing the life of the ion exchange membrane 51 from being shortened. This also improves the life and reliability of the electrolytic cell 11.

[0086] (Second embodiment) Next, a second embodiment will be described. The second embodiment differs from the first embodiment in that the electrolysis device 1A has a chloride ion removal section 80. Note that the configuration other than that described below is the same as that of the first embodiment.

[0087] FIG. 9 is a diagram showing the configuration of an electrolysis apparatus 1A according to a second embodiment. This embodiment is an example that corresponds to a case where chloride ions are eluted from the ion exchange membrane 51 when the ion exchange membrane 51 is immersed in the electrolyte. The electrolysis apparatus 1A has a chloride ion removal unit 80 in addition to the configuration of the first embodiment. The chloride ion removal unit 80 is a functional unit that removes chloride ions eluted from the ion exchange membrane 51 into the electrolyte. The chloride ion removal unit 80 is provided midway along the anode-side circulation line Lb. The chloride ion removal unit 80 may be provided in either the pipe L3 or the pipe L4.

[0088] In this embodiment, the chloride ion removal unit 80 has a silver or silver-plated mesh structure 81. When the electrolyte circulating through the anode-side circulation line Lb passes through the mesh structure 81, chloride ions are insolubilized and removed.

[0089] Specifically, chloride ions (Cl - ) is present, the following chemical reactions can occur in the cathode chamber Sa and the anode chamber Sb, respectively: (Cathode chamber)2H2O+2e - →H2+2OH - …(C4) (Anode chamber)2KCl+2OH - →2KOH+2e - +Cl2…(chemical 5) (Whole cell) 2KCl + H2O → 2KOH + H2 + Cl2... (Chemical formula 6)

[0090] That is, for example, in the ion exchange membrane 51 which is an anion exchange membrane, chloride ions (Cl - ) are captured by the ion exchange groups (quaternary ammonium groups, etc.) of the ion exchange membrane 51, but the chloride ions (Cl - ) is the hydroxide ion (OH) of potassium hydroxide solution (KOH). - ), it dissolves into the electrolyte as free potassium chloride (KCl). In this case, when the water electrolysis process starts, two chloride ions (Cl -) may be reduced to generate gaseous chlorine gas (Cl2). Although the amount of chlorine gas (Cl2) generated is small, it is toxic and therefore it is preferable to be able to remove it.

[0091] Therefore, in this embodiment, the mesh structure 81 made of silver or plated with silver has a flow path. In this case, the following chemical reaction occurs in the electrolyte passing through the mesh structure 81. KCl + Ag + H2O → AgCl (insoluble solid) + KOH + 1 / 2H2... (Chemical formula 7)

[0092] That is, the chloride ions react with the silver of the mesh structure 81 and precipitate as AgCl (silver chloride) on the surface of the mesh structure 81, solidifying it. This removes the chloride ions from the electrolytic solution, suppressing the generation of chlorine gas. This makes it possible to suppress the generation of chlorine gas even when an ion exchange membrane 51 containing chloride ions is used. This allows the reliability of the electrolytic cell 11 and the electrolytic device 1 to be further improved.

[0093] Next, several modified examples of the second embodiment will be described. Note that the configuration of each modified example is the same as that of the second embodiment except for the configuration described below.

[0094] (First Modification) FIG. 10 is a diagram showing the configuration of an electrolysis device 1B according to a second modification of the second embodiment. The chloride ion removal unit 80 of the electrolysis device 1B has a filtering structure 82 containing silver particles or silver-plated particles instead of a mesh structure 81. The filtering structure 82 includes, for example, silver particles or silver-plated particles and a container (for example, a cartridge) that contains the silver particles or silver-plated particles. The silver particles are, for example, particles having a diameter of approximately 0.1 mm to several mm. The silver-plated particles are, for example, metal oxide (for example, ceramic) particles whose surfaces are silver-plated, thereby depositing silver nanoparticles having a diameter of several tens to several hundreds of nm on their surfaces. These types of particles are preferred because they ensure a large surface area for chemical reactions to occur.

[0095] According to this configuration, as in the second embodiment, even when an ion exchange membrane 51 from which chloride ions can be eluted is used, it is possible to suppress the generation of chlorine gas, thereby further improving the reliability of the electrolytic cell 11 and the electrolysis device 1.

[0096] (Second Modification) FIG. 11 is a diagram showing the overall configuration of an electrolysis apparatus 1C according to a second modified example of the second embodiment. The chloride ion removing unit 80 of the electrolysis apparatus 1C has a chloride ion removing agent feeding unit 83 instead of a mesh structure 81. The chloride ion removing agent feeding unit 83 is a functional unit that feeds a chloride ion removing agent into the electrolytic solution. The chloride ion removing agent is fed into the electrolytic solution circulating through the anode-side circulation line Lb by the chloride ion removing agent feeding unit 83, thereby insolubilizing chloride ions. The chloride ion removing agent feeding unit 83 feeds the chloride ion removing agent into the electrolytic solution based on, for example, a control instruction from a control device (not shown). The chloride ion removing agent may be fed manually.

[0097] The chloride ion remover is, for example, a silver nitrate (AgNO3) aqueous solution. Note that, since the silver nitrate aqueous solution precipitates as silver hydroxide (AgOH: solid) in an alkaline electrolyte (e.g., potassium hydroxide aqueous solution), and immediately turns into silver oxide (Ag2O: solid) after the precipitation, it is preferable to use it after diluting it to a certain extent.

[0098] According to this configuration, even when an ion exchange membrane 51 containing chloride ions is used, it is possible to suppress the generation of chlorine gas, as in the second embodiment, thereby further improving the reliability of the electrolysis cell 11 and the electrolysis device 1.

[0099] (Other embodiments) In the above-described embodiment, the process of supplying the electrolytic solution into the electrolytic cell 11 to immerse the ion exchange membrane 51 in the electrolytic solution (the process of S102 in FIG. 6 ) is performed using the cathode-side circulation line La and the anode-side circulation line Lb that supply the electrolytic solution into the electrolytic cell 11 during normal operation. Note that the process of supplying the electrolytic solution into the electrolytic cell 11 to immerse the ion exchange membrane 51 in the electrolytic solution is not limited to using the cathode-side circulation line La and the anode-side circulation line Lb, and may be performed using piping and equipment dedicated to the manufacture of the electrolytic device 1 (dedicated to immersion).

[0100] In the above-described embodiment, the cathode catalyst layer 52 and the anode catalyst layer 53 are formed by applying a catalyst material to the surface of the ion exchange membrane 51 and are integrated with the ion exchange membrane 51 as part of the membrane electrode assembly 45. Alternatively, the cathode catalyst layer 52 may be applied to the surface of the cathode current collector 43 and be integrated with the cathode current collector 43. Furthermore, the anode catalyst layer 53 may be applied to the anode current collector 44 and be integrated with the anode current collector 44.

[0101] The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure.

[0102] <Additional Notes> The method for manufacturing the electrolytic cell 11 and the method for manufacturing the electrolytic devices 1, 1A, 1B, and 1C described in each embodiment can be understood, for example, as follows.

[0103] (1) A first embodiment of a method for producing an electrolytic cell 11 is a method for producing an electrolytic cell 11, in which the electrolytic cell 11 includes a first separator 41, a second separator 42, an ion exchange membrane 51 disposed between the first separator 41 and the second separator 42, a cathode current collector 43 disposed between the first separator 41 and the ion exchange membrane 51, a cathode catalyst layer 52 disposed between the cathode current collector 43 and the ion exchange membrane 51, an anode current collector 44 disposed between the second separator 42 and the ion exchange membrane 51, and a cathode catalyst layer 52 disposed between the anode current collector 44 and the ion exchange membrane 51. and an anode catalyst layer 53 sandwiched between a first separator 41 and a second separator 42 before the ion exchange membrane 51 is immersed in the electrolyte, and the manufacturing method includes assembling an electrolytic cell 11 so that the ion exchange membrane 51, the cathode current collector 43, the cathode catalyst layer 52, the anode current collector 44, and the anode catalyst layer 53 are sandwiched between a first separator 41 and a second separator 42, supplying an electrolyte solution into the electrolytic cell 11 after assembling the electrolytic cell 11, and storing the electrolytic cell 11 or circulating the electrolyte solution for a predetermined period of time in a state where the electrolyte solution is present inside the electrolytic cell 11, thereby immersing the ion exchange membrane 51 in the electrolyte solution.

[0104] According to this configuration, the electrolytic cell 11 can be assembled while the ion exchange membrane 51 is dry, which makes it easier to handle the ion exchange membrane 51 than when the ion exchange membrane 51 is wet with the electrolytic solution, shortens the time required to adjust the installation position of the ion exchange membrane 51, and also increases the accuracy of the installation position of the ion exchange membrane 51. This improves the ease of assembly of the electrolytic cell 11.

[0105] (2) A second embodiment of the method for producing an electrolytic cell 11 is the method for producing an electrolytic cell 11 of (1), in which immersing the ion exchange membrane 51 in the electrolytic solution includes supplying the electrolytic solution to the inside of the electrolytic cell 11 in a state in which the electrolytic solution has been adjusted to a predetermined concentration used during normal operation of the electrolytic cell 11, and storing or circulating the electrolytic solution for the predetermined period of time in a state in which the electrolytic solution of the predetermined concentration is present inside the electrolytic cell 11.

[0106] According to this configuration, after the ion exchange membrane 51 is immersed, the electrolytic solution can be used as is to perform water electrolysis. Furthermore, if the swelling state of the ion exchange membrane 51 varies depending on the concentration of the electrolytic solution, by making the concentration of the electrolytic solution during immersion the same as the concentration of the electrolytic solution during normal use, the state of the ion exchange membrane 51 during immersion and during normal use will be the same, and the operational stability of the electrolysis device 1 can be improved.

[0107] (3) A third aspect of the method for producing an electrolytic cell 11 is the method for producing an electrolytic cell 11 of (1) or (2), in which immersing the ion exchange membrane 51 in the electrolytic solution includes circulating the electrolytic solution for the above-mentioned predetermined time while the electrolytic solution is present inside the electrolytic cell 11.

[0108] According to this configuration, by circulating the electrolyte during immersion, new electrolyte can be supplied to the vicinity of the ion exchange membrane 51, and the speed of immersion of the ion exchange membrane 51 (substitution of functional groups with hydroxide ions) can be increased. This allows the electrolysis device 1 to start water electrolysis sooner.

[0109] (4) A fourth aspect of the method for producing an electrolytic cell 11 is a method for producing an electrolytic cell 11 according to any one of (1) to (3), in which immersing the ion exchange membrane 51 in the electrolytic solution includes heating the electrolytic cell 11 in a state in which the electrolytic solution is present inside the electrolytic cell 11, and storing the electrolytic cell 11 at a temperature higher than room temperature or circulating the electrolytic solution therein.

[0110] According to this configuration, the temperature of the electrolytic cell 11 can be increased during immersion to increase the speed of immersion of the ion exchange membrane 51 (substitution of functional groups with hydroxide ions), thereby hastening the start of water electrolysis by the electrolysis device 1.

[0111] (5) A fifth aspect of the method for producing the electrolytic cell 11 is a method for producing the electrolytic cell 11 according to any one of (1) to (4), in which the ion exchange membrane 51 is immersed in the electrolytic solution by storing or circulating the electrolytic solution for the predetermined period of time, and then normal operation of the electrolytic cell 11 is started by directly utilizing at least a portion of the electrolytic solution used for immersion.

[0112] With this configuration, the electrolyte used for immersion can be used as is, thereby enabling effective use of the electrolyte. Furthermore, by not requiring replacement of the electrolyte, the start of water electrolysis by the electrolysis device 1 can be accelerated.

[0113] (6) A sixth aspect of the method for producing an electrolytic cell 11 is a method for producing an electrolytic cell 11 according to any one of (1) to (4), further comprising: immersing the ion exchange membrane 51 in the electrolytic solution by storing or circulating the electrolytic solution for the predetermined period of time; then discharging the electrolytic solution used for immersion from the electrolytic cell 11; and supplying new electrolytic solution into the electrolytic cell 11.

[0114] According to this configuration, if impurities are contained in the electrolytic solution due to immersion, the impurity-containing electrolytic solution can be discharged and new electrolytic solution can be used to perform water electrolysis, which may improve the reliability of the electrolysis device 1.

[0115] (7) A seventh aspect of the method for producing an electrolytic cell 11 is a method for producing an electrolytic cell 11 according to any one of (1) to (6), in which immersing the ion exchange membrane 51 in the electrolytic solution includes circulating the electrolytic solution for the predetermined time while the electrolytic solution is present inside the electrolytic cell 11, and the circulation of the electrolytic solution is carried out so that at least a portion of the electrolytic solution passes through the chloride ion removal section 80.

[0116] According to this configuration, when chloride ions are mixed into the electrolytic solution due to immersion, the chloride ions can be removed, which may improve the reliability of the electrolysis device 1.

[0117] (8) An eighth aspect of the method for producing an electrolytic cell 11 is the method for producing an electrolytic cell 11 of (7), in which the chloride ion removal unit 80 has a silver or silver-plated mesh structure 81. With this configuration, chloride ions can be efficiently removed by the mesh structure 81.

[0118] (9) A ninth aspect of the method for producing an electrolytic cell 11 is the method for producing an electrolytic cell 11 according to (7) or (8), in which the chloride ion removal unit 80 has a filtering structure 82 containing silver particles or silver-plated particles. With this configuration, chloride ions can be efficiently removed by the filtering structure 82.

[0119] (10) A tenth aspect of the method for producing an electrolytic cell 11 is the method for producing an electrolytic cell 11 according to any one of (7) to (9), further comprising adding a chloride ion removing agent to the electrolytic solution. This configuration allows chloride ions to be efficiently removed by the chloride ion removing agent.

[0120] (11) A method for producing an electrolysis device 1 according to an eleventh aspect is a method for producing an electrolysis device 1 including a plurality of electrolysis cells 11, each of the plurality of electrolysis cells 11 including a first separator 41, a second separator 42, an ion exchange membrane 51 disposed between the first separator 41 and the second separator 42, a cathode current collector 43 disposed between the first separator 41 and the ion exchange membrane 51, a cathode catalyst layer 52 disposed between the cathode current collector 43 and the ion exchange membrane 51, an anode current collector 44 disposed between the second separator 42 and the ion exchange membrane 51, and a cathode catalyst layer 52 disposed between the anode current collector 44 and the ion exchange membrane 51. and an anode catalyst layer 53 disposed between the first separator 41 and the second separator 42, and the manufacturing method includes assembling an electrolytic cell 11 such that the ion exchange membrane 51, the cathode current collector 43, the cathode catalyst layer 52, the anode current collector 44, and the anode catalyst layer 53 are sandwiched between the first separator 41 and the second separator 42 before the ion exchange membrane 51 is immersed in the electrolytic solution, supplying the electrolytic solution into the electrolytic cell 11 after assembling the electrolytic cell 11, and storing or circulating the electrolytic solution for a predetermined period of time in a state in which the electrolytic solution is present inside the electrolytic cell 11, thereby immersing the ion exchange membrane 51 in the electrolytic solution.

[0121] According to this configuration, the electrolytic cell 11 can be assembled while the ion exchange membrane 51 is dry, which makes it easier to handle the ion exchange membrane 51 than when the ion exchange membrane 51 is wet with the electrolytic solution, shortens the time required to adjust the installation position of the ion exchange membrane 51, and also increases the accuracy of the installation position of the ion exchange membrane 51. This improves the ease of assembly of the electrolytic cell 11. [Explanation of symbols]

[0122] 1,1A,1B,1C…Electrolyzer 10...Electrolysis cell stack 11...Electrolytic cell 22...First pump 27...Second pump 20...Electrolyte supply section 30...Power supply section 35...Heating device La: Cathode side circulation line Lb: Anode side circulation line 41...First separator 42...Second separator 43...Cathode power supply 44...Anode power supply 51...Ion exchange membrane 52...Cathode catalyst layer 53...Anode catalyst layer 80...Chloride ion removal section 81...Mesh structure 82…filtration structure 83...Chloride ion removing agent injection section

Claims

1. 1. A method for manufacturing an electrolysis cell, comprising: The electrolysis cell comprises: a first separator; a second separator; and an ion exchange membrane that is an anion exchange membrane disposed between the first separator and the second separator; a cathode current collector disposed between the first separator and the ion exchange membrane; a cathode catalyst layer disposed between the cathode current collector and the ion exchange membrane; an anode current collector disposed between the second separator and the ion exchange membrane; an anode catalyst layer disposed between the anode current collector and the ion exchange membrane; Equipped with The manufacturing method includes: before the ion exchange membrane is immersed in the electrolytic solution, the electrolytic cell is assembled so that the ion exchange membrane, the cathode current collector, the cathode catalyst layer, the anode current collector, and the anode catalyst layer are sandwiched between the first separator and the second separator; After assembling the electrolytic cell, an electrolyte solution which is an alkaline aqueous solution is supplied into the electrolytic cell; With the electrolytic solution present inside the electrolytic cell, the electrolytic solution is circulated for a predetermined time, thereby immersing the ion exchange membrane in the electrolytic solution. This includes: immersing the ion exchange membrane in the electrolytic solution includes heating the electrolytic cell with the electrolytic solution present inside the electrolytic cell, and circulating the electrolytic solution while maintaining the temperature at a temperature range of 60°C or higher and lower than 100°C, which is the same as the operating temperature range of the electrolytic cell, to replace chloride ions contained in the ion exchange membrane with hydroxide ions. Method for manufacturing electrolytic cells.

2. immersing the ion exchange membrane in the electrolytic solution includes supplying the electrolytic solution into the electrolytic cell in a state in which the electrolytic solution has been adjusted to a predetermined concentration used during normal operation of the electrolytic cell, and circulating the electrolytic solution for the predetermined time in a state in which the electrolytic solution of the predetermined concentration is present inside the electrolytic cell. A method for producing the electrolytic cell according to claim 1 .

3. After the ion exchange membrane is immersed in the electrolytic solution by circulating the electrolytic solution for the predetermined time, normal operation of the electrolytic cell is started by utilizing at least a portion of the electrolytic solution used for immersion. The method for producing the electrolytic cell according to claim 1 or 2.

4. the method further includes circulating the electrolytic solution for the predetermined time to immerse the ion exchange membrane in the electrolytic solution, and then discharging the electrolytic solution used for immersion from the electrolytic cell and supplying new electrolytic solution into the electrolytic cell. The method for producing the electrolytic cell according to claim 1 or 2.

5. 3. The method for manufacturing an electrolytic cell according to claim 1 or 2, wherein immersing the ion exchange membrane in the electrolytic solution includes circulating the electrolytic solution for the predetermined time in a state where the electrolytic solution is present inside the electrolytic cell, and the circulation of the electrolytic solution is performed such that at least a portion of the electrolytic solution passes through a chloride ion removal section.

6. The chloride ion removal unit has a silver or silver-plated mesh structure. A method for producing the electrolytic cell according to claim 5.

7. The method for manufacturing an electrolytic cell according to claim 5 , wherein the chloride ion removal section has a filtering structure containing silver particles or silver-plated particles.

8. Further comprising adding a chloride ion removing agent to the electrolyte. The method for producing the electrolytic cell according to claim 1 or 2.

9. 1. A method for manufacturing an electrolysis device including a plurality of electrolysis cells, comprising: Each of the plurality of electrolysis cells comprises: a first separator; a second separator; and an ion exchange membrane that is an anion exchange membrane disposed between the first separator and the second separator; a cathode current collector disposed between the first separator and the ion exchange membrane; a cathode catalyst layer disposed between the cathode current collector and the ion exchange membrane; an anode current collector disposed between the second separator and the ion exchange membrane; an anode catalyst layer disposed between the anode current collector and the ion exchange membrane; Equipped with The manufacturing method includes: before the ion exchange membrane is immersed in the electrolytic solution, the electrolytic cell is assembled so that the ion exchange membrane, the cathode current collector, the cathode catalyst layer, the anode current collector, and the anode catalyst layer are sandwiched between the first separator and the second separator; After assembling the electrolytic cell, an electrolyte solution which is an alkaline aqueous solution is supplied into the electrolytic cell; With the electrolytic solution present inside the electrolytic cell, the electrolytic solution is circulated for a predetermined time, thereby immersing the ion exchange membrane in the electrolytic solution. This includes: immersing the ion exchange membrane in the electrolytic solution includes heating the electrolytic cell with the electrolytic solution present inside the electrolytic cell, and circulating the electrolytic solution while maintaining the temperature at a temperature range of 60°C or higher and lower than 100°C, which is the same as the operating temperature range of the electrolytic cell, to replace chloride ions contained in the ion exchange membrane with hydroxide ions. Method for manufacturing an electrolysis device.

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