Electrolysis cell and electrolysis device

Abstract

In an electrolysis cell according to the present disclosure, an insulating packing material has: an annular packing body; an arc-shaped packing material having an arc shape formed inside the packing body and surrounding a first supply hole and a first discharge hole from the outer peripheral side, respectively; and a triangular packing material. In the arc-shaped packing material, which is in a state prior to elastic deformation by being sandwiched between a separator and an anion exchange membrane, the thickness of the arc-shaped packing material is set to be greater than the gap between a first diffusion guide part and the anion exchange membrane, and in the triangular packing material, the thickness thereof is set to be greater than that of the packing body.

Description

Electrolytic cell and electrolytic device

[0001] This application claims priority to Japanese Patent Application No. 2024-053567, filed on March 28, 2024, the contents of which are incorporated herein by reference.

[0002] Water electrolysis devices (electrolysis devices) are known as devices for generating hydrogen. In this type of device, an electrolytic cell separated into a cathode chamber and an anode chamber by an ion exchange membrane is filled with water, and water is electrolyzed by supplying electricity to the cathode and anode. In the cathode chamber, hydrogen is generated by a reaction between water and electrons. The hydroxide ions produced by this reaction permeate the ion exchange membrane and reach the anode chamber. In the anode chamber, oxygen and water are generated from these hydroxide ions. By continuing this reaction, large amounts of hydrogen can be obtained.

[0003] More specifically, the ion exchange membrane is sandwiched between plate-like members called separators on both sides in the thickness direction, and a flow path through which the electrolyte flows is formed on the surface of the separator. To prevent leakage of the electrolyte from the flow path, a sealing member (insulating packing) is interposed between the separator and the ion exchange membrane (see, for example, Patent Document 1 below). In the device disclosed in Patent Document 1 below, a resin material with a uniform thickness is used as the sealing member.

[0004] Japanese Patent Application Laid-Open No. 2021-191886

[0005] When the electrolyte flows through the flow path under high pressure, the distribution of the surface pressure between the separator and the insulating packing tends to vary depending on the position. Therefore, if an insulating packing with a uniform thickness is used as described above, a sufficient sealing effect cannot be obtained in the area where the surface pressure is low. As a result, there is a risk of leakage of the electrolyte.

[0006] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide an electrolysis cell and an electrolysis device in which leakage of electrolyte is further suppressed.

[0007] In order to solve the above problems, an electrolytic cell according to the present disclosure includes a pair of separators, an anion exchange membrane disposed between the pair of separators, and insulating gaskets provided between the anion exchange membrane and each of the separators, wherein the separators each have a rectangular plate-like shape and include a separator body having a first surface facing one side in a thickness direction and a second surface facing the other side, a first supply hole and a first discharge hole formed on one diagonal line of the separator body on the first surface and penetrating the separator body from the first surface toward the second surface, and a main flow path formed in a region between the supply hole and the first discharge hole, the main flow path having a plurality of first groove portions extending in the longitudinal direction of the separator body and arranged at intervals in a width direction perpendicular to the longitudinal direction; a trapezoidal first diffusion flow path extending from the first supply hole to the first groove portion and recessed from the first surface side toward the second surface side, the dimension in the width direction gradually increasing from the first supply hole to the first groove portion as viewed from the first surface side; and a trapezoidal first diffusion flow path extending from the first groove portion to the first discharge hole and recessed from the first surface side toward the second surface side, a first convergent flow path having a trapezoidal shape whose dimension in the width direction gradually decreases from the first groove portion toward the first discharge hole as viewed from the first surface side; a first diffusion guide portion provided in the first diffusion flow path, protruding from the second surface side toward the first surface side and extending radially from the first supply hole to guide the fluid from the first supply hole to the first groove portion; and a first convergent flow path provided in the first convergent flow path, protruding from the second surface side toward the first surface side and extending radially from the first discharge hole to guide the fluid from the first groove portion to the first discharge hole. the insulating packing has a packing body arranged outside the main flow path, the first diffusion flow path, and the first convergent flow path and having an annular shape when viewed from the first surface side, arc-shaped arc packings formed inside the packing body and extending so as to straddle the first diffusion flow path and the first convergent flow path, respectively, and surrounding the first supply hole and the first discharge hole from the outer periphery, and triangular packings formed inside the packing body and extending to the oblique sides of the first diffusion flow path and the first convergent flow path, respectively,The arc-shaped packing, which is sandwiched between the separator and the anion exchange membrane and is not elastically deformed, has a thickness set to be larger than the gap between the first diffusion guide portion and the anion exchange membrane.

[0008] The electrolysis device according to the present disclosure includes the electrolysis cell described above, an electrolyte solution supply unit that supplies an electrolyte solution to the electrolysis cell, and a power supply unit that applies a voltage to the electrolysis cell.

[0009] According to the present disclosure, it is possible to provide an electrolysis cell and an electrolysis device in which leakage of electrolyte is further suppressed.

[0010] FIG. 1 is a schematic diagram illustrating the configuration of an electrolysis device according to an embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view illustrating the configuration of an electrolysis cell according to an embodiment of the present disclosure. FIG. 3 is an exploded perspective view illustrating the configuration of an electrolysis cell according to an embodiment of the present disclosure. FIG. 4 is a schematic cross-sectional view illustrating the configuration of a separator and an insulating gasket according to an embodiment of the present disclosure. FIG. 5 is a schematic cross-sectional view illustrating the configuration of an electrolysis cell stack according to an embodiment of the present disclosure. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 4. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 4. FIG. 7 is a graph illustrating the relationship between the material of an insulating gasket according to an embodiment of the present disclosure and an example of the results of a load test. FIG. 8 is a cross-sectional view illustrating a modified example of a separator according to an embodiment of the present disclosure. FIG. 9 is a plan view illustrating a further modified example of a separator according to an embodiment of the present disclosure.

[0011] Hereinafter, an electrolytic cell and an electrolytic device according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 7 .

[0012] Hereinafter, an embodiment of an electrolysis device 1 according to the present disclosure will be described with reference to the accompanying drawings. In the following description, components having the same or similar functions will be denoted by the same reference numerals. In this specification, the term "opposing" means that two members overlap when viewed in a certain direction, and may also include the case where another member (e.g., another layer) exists between the two members.

[0013] First, with reference to FIG. 2 , the Z direction, X direction, and Y direction are defined. The Z direction is the direction from a first separator 11a to a second separator 11b (described later) (to the right in FIG. 2 ). The X direction is a direction intersecting (e.g., perpendicular to) the Z direction and is a direction from a center C of the electrolysis cell 12 to one end of the electrolysis cell 12 (the up-and-down direction in FIG. 2 ). The X direction is, for example, the vertical direction. The Y direction is a direction intersecting (e.g., perpendicular to) the Z direction and the X direction and is, for example, the depth direction of the paper in FIG. 2 . In this specification, the term "external size" refers to the external size when viewed in the Z direction.

[0014] 1 is a schematic diagram showing the overall 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 proton exchange membrane (PEM) type electrolysis device or a device that electrolytically reduces carbon dioxide.

[0015] The electrolysis device 1 includes, for example, an electrolysis cell stack 10 , an electrolyte supply unit 20 , and a power supply unit 30 .

[0016] (Electrolysis Cell Stack) The electrolysis cell stack 10 electrolyzes an externally supplied electrolytic solution Es. The electrolysis cell stack 10 is an assembly of a plurality of separators 11 and a plurality of electrolysis cells 12. The electrolysis cell stack 10 is formed by arranging a plurality of separators 11 and a plurality of electrolysis cells 12 in one direction. In this embodiment, an example is described in which the electrolysis cell stack 10 is formed by arranging five separators 11 and four electrolysis cells 12 (see FIG. 6 ).

[0017] Hereinafter, the above-mentioned direction (the left-right direction in FIG. 6 ) in which the plurality of separators 11 and the plurality of electrolytic cells 12 are arranged will be referred to as the "first direction D1." Furthermore, one side of the first direction D1 (the left side in FIG. 6 ) will be simply referred to as the "one side dl," and the side opposite the one side dl will be referred to as the "other side dr." Hereinafter, for ease of explanation, the five separators 11 will be referred to in order from the one side dl as the "first separator 11a," the "second separator 11b," the "third separator 11c," the "fourth separator 11d," and the "fifth separator 11e." Furthermore, the four electrolytic cells 12 will be referred to in order from the one side dl as the "first electrolytic cell 12a," the "second electrolytic cell 12b," the "third electrolytic cell 12c," and the "fourth electrolytic cell 12d."

[0018] As shown in FIG. 5 , the electrolytic cell stack 10 includes a plurality of (four) electrolytic cells 12 that, together with separators 11, form a cathode chamber Sa and an anode chamber Sb; first flow path sections 13, 13′ (described later) that allow the electrolytic solution Es supplied from the electrolytic solution supply section 20 to flow toward the cathode chamber Sa and the anode chamber Sb; and second flow path sections 14, 14′ (described later) that allow the electrolytic solution that has completed the reaction in the cathode chamber Sa and the anode chamber Sb to flow toward (return) the electrolytic solution supply section 20. The electrolytic cell stack 10 will be described in detail later. Note that the number of separators 11 and the number of electrolytic cells 12 are not limited to those described above. Each electrolytic cell 12 includes a cathode chamber Sa and an anode chamber Sb. The electrolytic cells 12 will also be described in detail later.

[0019] (Electrolyte Solution Supply Unit) The electrolyte solution supply unit 20 is a supply unit that supplies the electrolyte solution Es to each electrolytic cell 12. The electrolyte solution Es is, for example, pure water or an alkaline aqueous solution. The electrolyte solution supply unit 20 includes a cathode side supply unit 20 a and an anode side supply unit 20 b.

[0020] The cathode side supply unit 20a is a supply unit that supplies the electrolytic solution Es to the cathode chamber Sa of each electrolytic cell 12. 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.

[0021] The hydrogen-gas-liquid separator 21 stores the electrolytic solution Es. A supply port of the hydrogen-gas-liquid separator 21 is connected to the cathode chamber Sa of the electrolytic cell 12 via a piping line L1. The first pump 22 is provided midway along the piping line L1 and sends the electrolytic solution Es stored in the hydrogen-gas-liquid separator 21 toward the cathode chamber Sa of the electrolytic cell 12.

[0022] A return port of the hydrogen-gas-liquid separator 21 is connected to the cathode chamber Sa of the electrolytic cell 12 via a piping line L2. Electrolyte solution Es containing hydrogen produced in the electrolytic cell 12 flows into the hydrogen-gas-liquid separator 21 from the electrolytic cell 12. The hydrogen-gas-liquid separator 21 has a gas-liquid separation unit that separates the hydrogen contained in the electrolytic solution Es. The hydrogen separated from the electrolytic solution Es 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 Es from a first electrolytic solution supply unit 24.

[0023] On the other hand, the anode side supply unit 20b is a supply unit that supplies the electrolytic solution Es to the anode chamber Sb of each electrolytic cell 12. 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.

[0024] The oxygen-gas-liquid separator 26 stores the electrolytic solution Es. A supply port of the oxygen-gas-liquid separator 26 is connected to the anode chamber Sb of the electrolytic cell 12 via a piping line L3. A second pump 27 is provided in the piping line L3 and sends the electrolytic solution Es stored in the oxygen-gas-liquid separator 26 toward the anode chamber Sb of the electrolytic cell 12.

[0025] A return port of the oxygen-gas-liquid separator 26 is connected to the anode chamber Sb of the electrolytic cell 12 via a piping line L4. The oxygen-containing electrolytic solution Es produced in the electrolytic cell 12 flows into the oxygen-gas-liquid separator 26 from the electrolytic cell 12. The oxygen-gas-liquid separator 26 has a gas-liquid separation unit that separates the oxygen contained in the electrolytic solution Es. The oxygen separated from the electrolytic solution Es by the oxygen-gas-liquid separator 26 is recovered by an oxygen recovery unit 28. The oxygen-gas-liquid separator 26 is replenished with the electrolytic solution Es from a second electrolytic solution supply unit 29.

[0026] (Power Supply Unit) The power supply unit 30 is a DC power supply device that applies a voltage to each separator 11 of the electrolytic cell stack 10. The power supply unit 30 applies a voltage to each separator 11 in the first direction D1, thereby applying a DC voltage required for electrolysis of the electrolytic solution Es between the anode 122 and the cathode 121 of each electrolytic cell 12.

[0027] (Configuration of Electrolysis Cell Stack) Next, the electrolysis cell stack 10 will be described in detail with reference to Fig. 2 to Fig. 6. Fig. 2 is a diagram schematically illustrating a part of the electrolysis cell stack 10. Fig. 2 focuses on the electrolysis cell 12 (first electrolysis cell 12a) arranged on the furthest side dl among the electrolysis cells 12 arranged in the first direction D1 (the left-right direction in Fig. 5).

[0028] As shown in FIG. 5 , the electrolysis cell stack 10 includes, for example, a plurality of separators 11 and a plurality of electrolysis cells 12 .

[0029] (Separator) The separator 11 is a member that defines the internal space S in which the electrolytic cell 12 is disposed. The internal space S is a space that includes a cathode chamber Sa and an anode chamber Sb, which will be described later. The separator 11 has, for example, a rectangular plate shape when viewed from the first direction D1, and is formed of a metal member or the like. The separators 11 are arranged at intervals from each other in the first direction D1.

[0030] The separator 11 has a first surface 201a facing one side in the thickness direction and a second surface 201b facing the other side. The configurations of the first surface 201a and the second surface 201b (described later) are point-symmetric with respect to the geometric center of gravity of the separator 11. The configuration of the first surface 201a side will be representatively described below with reference to FIG. 4 .

[0031] The separator 11 includes a rectangular plate-shaped separator body 201, a first discharge hole 202, a first supply hole 203, a first groove portion 204 (main flow path 204a), a first convergence flow path 205, a first diffusion flow path 206, a first convergence guide portion 207, a first diffusion guide portion 208, a straight section 209, a second discharge hole 210, a second supply hole 211, and a second groove portion 212.

[0032] The first supply hole 203 and the first discharge hole 202 are each arranged at a corner along one of two diagonal lines connecting the corners of the rectangular separator body 201. The first supply hole 203 and the first discharge hole 202 are circular holes that penetrate the separator body 201 from the first surface side to the second surface side. The diameter of the first discharge hole 202 is set larger than the diameter of the first supply hole 203. In addition, a second supply hole 211 and a second discharge hole 210 are provided at each corner along the other of the two diagonal lines connecting the corners of the separator body 201.

[0033] The first groove portions 204, first diffusion channels 206, first convergence channels 205, first diffusion guide portions 208, and first convergence guide portions 207 are formed only on the first surface 201a. The first groove portions 204 are formed in the region between the first supply holes 203 and the first discharge holes 202. The first groove portions 204 extend in the longitudinal direction of the separator body 201 and are arranged at intervals in the width direction perpendicular to the longitudinal direction. The first groove portions 204 have a rectangular cross section that is concave from the first surface 201a toward the second surface 201b.

[0034] The first diffusion channel 206 extends from the first supply hole 203 to the first groove 204 and forms a channel by being recessed from the first surface 201a toward the second surface 201b. When viewed from the first surface 201a, the first diffusion channel 206 has a trapezoidal shape whose width gradually increases from the first supply hole 203 toward the first groove 204. More specifically, the first diffusion channel 206 is defined by a first side 206a extending in the width direction from an edge of the first supply hole 203, a second side 206b extending in a direction perpendicular to the first side 206a (the longitudinal direction), and a hypotenuse 206c facing the second side 206b in the width direction. The hypotenuse 206c extends in a direction away from the first supply hole 203 from one longitudinal side to the other. The angle that the oblique side 206c forms with respect to the width direction is preferably 24° or more and 50° or less, more preferably 30° or more and 45° or less, and most preferably 35° or more and 40° or less.

[0035] A first diffusion guide portion 208 is provided in the first diffusion channel 206. The first diffusion guide portions 208 protrude from the first surface 201a and are provided in a radial pattern centered on the first supply hole 203. The angle formed by the first diffusion guide portions 208 with respect to the width direction decreases as the first diffusion guide portions 208 become farther away from the first supply hole 203. Furthermore, the longitudinal dimension of the first diffusion guide portions 208 increases as the first diffusion guide portions 208 become farther away from the first supply hole 203.

[0036] A straight section 209 is provided between the first convergence channel 205 and the first groove portion 204. The width dimension of the straight section 209 is constant over the entire length. The length dimension of the straight section 209 is preferably about 25 mm.

[0037] The first convergence channel 205 forms a channel by expanding from the first groove portion 204 to the first discharge hole 202 and recessing from the first surface 201 a side toward the second surface 201 b side. The first convergence channel 205 has a trapezoidal shape whose width dimension gradually increases from the first discharge hole 202 toward the first groove portion 204 when viewed from the first surface 201 a side.

[0038] A first converging and guiding section 207 is provided within the first converging channel 205. The first converging and guiding sections 207 protrude from the first surface 201a and are provided in a plurality of sections radially from the first discharge hole 202. The angle formed by the first converging and guiding section 207 with respect to the width direction decreases as the section becomes farther away from the first discharge hole 202. Furthermore, the longitudinal dimension of the first converging and guiding section 207 increases as the section becomes farther away from the first discharge hole 202.

[0039] (Electrolysis Cell) The electrolysis cell (MEA: Membrane Electrode Assembly) 12 is a structure assembled by stacking an ion exchange membrane, a catalyst, a power supply, etc. As shown in Fig. 2 or 5 , the electrolysis cells 12 are disposed one by one between two adjacent separators 11, connecting the two adjacent separators 11 to each other in the first direction D1. Therefore, the electrolysis cells 12 are located in the internal space S between the two adjacent separators 11. The electrolysis cells 12 include, for example, an ion exchange membrane 120, a cathode 121, and an anode 122.

[0040] (Ion Exchange Membrane) The ion exchange membrane 120 is a membrane that selectively allows ions to pass through. The ion exchange membrane 120 is, for example, a solid polymer electrolyte membrane. The ion exchange membrane 120 is, for example, an anion exchange membrane (AEM) that is hydroxide ion conductive. However, the ion exchange membrane 120 is not limited to the above example, and may be a proton exchange membrane (PEM: Polymer Electrolyte Membrane) of a type different from the above example that is proton conductive.

[0041] The ion exchange membrane 120 has, for example, a rectangular sheet shape. The outer size of the ion exchange membrane 120 is smaller than the outer size of the separator 11 adjacent to it in the first direction D1. The ion exchange membrane 120 is disposed between two separators 11 adjacent to it in the first direction D1 and is located in the internal space S. The ion exchange membrane 120 has a first surface 120a facing the first inner surface 110a of the separator 11 located on one side dl of the ion exchange membrane 120, and a second surface 120b located on the opposite side from the first surface 120a. The first surface 120a of the ion exchange membrane 120 faces the one side dl. The second surface 120b of the ion exchange membrane 120 faces the other side dr. The second surface 120b of the ion exchange membrane 120 faces the second inner surface 110b of the separator 11 located on the other side dr of the ion exchange membrane 120.

[0042] In the internal space S, a cathode chamber Sa or an anode chamber Sb is defined between the first surface 120a of the ion exchange membrane 120 and the first inner surface 110a of the separator 11, and between the second surface 120b of the ion exchange membrane 120 and the second inner surface 110b of the separator 11. Specifically, a cathode chamber Sa is defined between the first surface 120a of the ion exchange membrane 120 of the first electrolytic cell 12a and the first inner surface 110a of the first separator 11a, and between the first surface 120a of the ion exchange membrane 120 of the third electrolytic cell 12c and the first inner surface 110a of the third separator 11c. On the other hand, an anode chamber Sb is defined between the second surface 120b of the ion exchange membrane 120 of the first electrolytic cell 12a and the second inner surface 110b of the second separator 11b, and between the second surface 120b of the ion exchange membrane 120 of the third electrolytic cell 12c and the second inner surface 110b of the fourth separator 11d.

[0043] A cathode chamber Sa is defined between the first surface 120a of the ion exchange membrane 120 of the second electrolytic cell 12b and the first inner surface 110a of the second separator 11b, and between the first surface 120a of the ion exchange membrane 120 of the fourth electrolytic cell 12d and the first inner surface 110a of the fourth separator 11d. An anode chamber Sb is defined between the second surface 120b of the ion exchange membrane 120 of the second electrolytic cell 12b and the second inner surface 110b of the third separator 11c, and between the second surface 120b of the ion exchange membrane 120 of the fourth electrolytic cell 12d and the second inner surface 110b of the fifth separator 11e.

[0044] In the cathode chamber Sa, when a voltage is applied to the electrolytic cell 12, the chemical reaction shown in the following formula (1) occurs, and hydrogen is produced from the electrolytic solution Es. In this specification, the phrase "XX is produced" may also include the case where other substances are produced simultaneously with the production of XX. The hydroxide ions produced in the cathode chamber Sa pass through the electrolytic cell 12 and move from the cathode chamber Sa to the anode chamber Sb. 2H ２ O + 2e － →H ２ +2OH － ...(Chemical 1)

[0045] On the other hand, in the anode chamber Sb, when a voltage is applied to the electrolytic cell 12, the chemical reaction shown in the following (chemical formula 2) occurs, and oxygen is produced from the electrolytic solution Es. － →1 / 2O ２ +H ２ O + 2e － ...(Case 2)

[0046] As a result, when viewed as a whole in the electrolytic cell 12, the chemical reaction shown in Chemical Formula 3 below occurs. ２ O → H ２ +1 / 2O ２ ...(Chem.3)

[0047] The ion exchange membrane 120 may have a high ion conductivity, for example, a polystyrene-based or tetraphenyl-based composition in the main chain and an imidazolium group or a quaternary ammonium group in the side chain. Alternatively, the ion exchange membrane 120 may have a high oxidation resistance, for example, a polysulfone-based or bromobutylstyrene-based composition.

[0048] (Cathode) The cathode 121 is disposed between the ion exchange membrane 120 and the separator 11, and is sandwiched between the ion exchange membrane 120 and the separator 11. The cathode 121 includes, for example, a cathode catalyst layer 121a and a cathode power supplier 121b.

[0049] The cathode catalyst layer 121a is a layer that promotes the chemical reaction in the cathode chamber Sa. The cathode catalyst layer 121a has, for example, a rectangular sheet shape. The cathode catalyst layer 121a is disposed in the cathode chamber Sa and fixed to the ion exchange membrane 120 by, for example, surface pressure bonding.

[0050] Specifically, the cathode catalyst layer 121a of the first electrolytic cell 12a, the cathode catalyst layer 121a of the second electrolytic cell 12b, the cathode catalyst layer 121a of the third electrolytic cell 12c, and the cathode catalyst layer 121a of the fourth electrolytic cell 12d are fixed to the first surface 120a of the ion exchange membrane 120, for example, by surface pressure bonding. The anode catalyst layers 122a of the first electrolytic cell 12a, the second electrolytic cell 12b, the third electrolytic cell 12c, and the fourth electrolytic cell 12d are fixed to the second surface 120b of the ion exchange membrane 120, for example, by surface pressure bonding. A negative voltage is applied to each cathode catalyst layer 121a from the power supply unit 30 via the separator 11 and the cathode power supply 121b.

[0051] The cathode catalyst layer 121a may be made of any material that promotes the chemical reaction in the cathode chamber Sa. For example, the cathode catalyst layer 121a may contain one or more of nickel, nickel alloy, cerium oxide, lanthanum oxide, or platinum. Note that the "XX oxide" in this specification may include materials other than XX and oxygen. Note that the cathode catalyst layer 121a may contain other materials, such as carbon, in addition to the above-mentioned materials. The outer size of the cathode catalyst layer 121a is smaller than the outer size of the ion exchange membrane 120, for example.

[0052] The cathode power supply 121b is an electrical connection part that transmits the voltage applied to the separator 11 to the cathode catalyst layer 121a. The cathode power supply 121b is disposed in the cathode chamber Sa. The cathode power supply 121b is located between the separator 11 and the cathode catalyst layer 121a.

[0053] Specifically, the cathode power supply 121b of the first electrolytic cell 12a is bonded to the first inner surface 110a and the cathode catalyst layer 121a of the first separator 11a, the cathode power supply 121b of the second electrolytic cell 12b is bonded to the first inner surface 110a and the cathode catalyst layer 121a of the second separator 11b, and the cathode power supply 121b of the third electrolytic cell 12c is bonded to the first inner surface 110a and the cathode catalyst layer 121a of the third separator 11c. The anode power supply 122b of the second electrolytic cell 12b is bonded to the second inner surface 110b and the anode catalyst layer 122a of the second separator 11b, and the anode power supply 122b of the fourth electrolytic cell 12d is bonded to the first inner surface 110a and the cathode catalyst layer 121a of the fourth separator 11d.

[0054] The cathode power supply 121b has a structure that allows the electrolyte Es and gas to pass through it. The cathode power supply 121b is formed, for example, from a metal mesh structure, a sintered body, or a fiber. In this embodiment, the external size of the cathode power supply 121b is the same as the external size of the cathode catalyst layer 121a.

[0055] (Anode) The anode 122 is disposed between the ion exchange membrane 120 and the separator 11, and is sandwiched between the ion exchange membrane 120 and the second separator 11b. The anode 122 includes, for example, an anode catalyst layer 122a and an anode power supplier 122b.

[0056] The anode catalyst layer 122a is a layer that promotes the chemical reaction in the anode chamber Sb. The anode catalyst layer 122a has, for example, a rectangular sheet shape. The anode catalyst layer 122a is disposed in the anode chamber Sb and fixed to the ion exchange membrane 120 by, for example, surface pressure bonding.

[0057] Specifically, the anode catalyst layer 122a of the first electrolytic cell 12a and the anode catalyst layer 122a of the third electrolytic cell 12c are fixed to the second surface 120b of the ion exchange membrane 120, for example, by surface pressure bonding. The anode catalyst layer 122a of the second electrolytic cell 12b and the anode catalyst layer 122a of the fourth electrolytic cell 12d are fixed to the first surface 120a of the ion exchange membrane 120, for example, by surface pressure bonding. A positive voltage is applied to each anode catalyst layer 122a from the power supply unit 30 via the separator 11 and the anode power supply 122b.

[0058] The anode catalyst layer 122a may be made of any material that promotes the chemical reaction in the anode chamber Sb. For example, the anode catalyst layer 122a 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, "XX oxide" in this specification may include other materials in addition to XX and oxygen. For example, "nickel oxide" may include other materials such as iron or cobalt in addition to nickel and oxygen. "Copper oxide" may include other materials such as cobalt in addition to copper and oxygen. "Iridium oxide" may include other materials such as ruthenium in addition to iridium and oxygen. "Lead oxide" may include other materials such as ruthenium in addition to lead and oxygen. "Bismuth oxide" may include other materials such as ruthenium in addition to bismuth and oxygen.

[0059] The anode power supply 122b is an electrical connection part that transmits the voltage applied to the separator 11 to the anode catalyst layer 122a. The anode power supply 122b is disposed in the anode chamber Sb. The anode power supply 122b is located between the separator 11 and the anode catalyst layer 122a.

[0060] Specifically, the anode power supply 122b of the first electrolytic cell 12a is bonded to the second inner surface 110b and the anode catalyst layer 122a of the second separator 11b, and the anode power supply 122b of the third electrolytic cell 12c is bonded to the second inner surface 110b and the anode catalyst layer 122a of the fourth separator 11d, respectively. The cathode power supply 121b of the second electrolytic cell 12b is bonded to the first inner surface 110a and the cathode catalyst layer 121a of the third separator 11c, and the cathode power supply 121b of the fourth electrolytic cell 12d is bonded to the second inner surface 110b and the cathode catalyst layer 121a of the fifth separator 11e, respectively.

[0061] The anode power supply body 122b has a structure that allows the electrolyte solution Es and gas to pass through it. The anode power supply body 122b is formed, for example, of a metal mesh structure, a sintered body, or a fiber. In this embodiment, the external size of the anode power supply body 122b is the same as the external size of the anode catalyst layer 122a.

[0062] Figure 3 is an exploded perspective view showing a part of the electrolysis cell stack 10. In addition to the above-described configuration, the electrolysis cell stack 10 includes, for example, a first current collector 61, a second current collector 62, a first insulator 65, a second insulator 66, a first end plate 67, and a second end plate 68. Note that Figure 3 omits the illustration of a first flow path section 13 and a second flow path section 14, which will be described later.

[0063] (First Current Collector) The first current collector 61 is an electrical connection part that transmits the negative voltage applied from the power supply unit 30 to the first separator 11a. That is, the first current collector 61 is electrically connected to the first separator 11a (detailed illustration of the connection is omitted). A negative voltage required for electrolysis in each electrolysis cell 12 is applied to the first current collector 61 from the power supply unit 30. The first current collector 61 is formed of a metal plate member (e.g., a copper plate) or the like.

[0064] (Second Current Collector) The second current collector 62 is an electrical connection part that transmits the positive voltage applied from the power supply unit 30 to the second separator 11b. That is, the second current collector 62 is electrically connected to the second separator 11b. The positive voltage required for electrolysis in each electrolysis cell 12 is applied to the second current collector 62 from the power supply unit 30. The second current collector 62 is formed of a metal plate member (e.g., a copper plate) or the like.

[0065] (First Insulating Material) The first insulating material 65 is located between the first current collector 61 and the first end plate 67. The outer size of the first insulating material 65 is, for example, the same as or larger than the outer size of the first current collector 61.

[0066] (Second Insulating Material) The second insulating material 66 is located between the second current collector 62 and the second end plate 68. The outer size of the second insulating material 66 is the same as or larger than the outer size of the second current collector 62.

[0067] (First End Plate) The first end plate 67 is located on the opposite side of the first insulating material 65 from the first current collector 61. The first end plate 67 is formed, for example, from a metal plate member (e.g., a stainless steel plate). The outer size of the first end plate 67 is larger than the outer size of the first insulating material 65, for example.

[0068] (Second End Plate) The second end plate 68 is located on the opposite side of the second insulating material 66 from the second current collector 62. The second end plate 68 is formed, for example, from a metal plate member (e.g., a stainless steel plate). The outer size of the second end plate 68 is larger than the outer size of the second insulating material 66, for example.

[0069] Furthermore, as shown in FIG. 3, the electrolysis cell stack 10 has, in addition to the above-described configuration, for example, a first insulator 63 and a second insulator 64.

[0070] (First insulator) The first insulator 63 provides insulation between the outer periphery of the separator 11 on one side dl and the outer periphery of the separator 11 on the other side dr of two adjacent separators 11. The first insulator 63 is a frame-shaped sheet member that is slightly larger than the external dimensions of the cathode catalyst layer 121 a and the anode catalyst layer 122 a and the cathode current collector 121 b and the anode current collector 122 b.

[0071] (Second Edge Body) Similar to the first insulator 47, the second insulator 64 provides insulation between the outer periphery of the separator 11 on the other side dr and the outer periphery of the separator 11 on one side dl of two adjacent separators 11. The second insulator 64 is a frame-shaped sheet member that is slightly larger than the external dimensions of the anode catalyst layer 122a and the cathode catalyst layer 121a and the anode power supply 122b and the cathode power supply 121b.

[0072] (Packing) The packing 60 (insulating packing) is a member that closes the internal space S between two adjacent separators 11. The packing 60 is disposed between two adjacent separators 11. The packing 60 is located outside (on the outer periphery side) of the outer edge portion 120e of the ion exchange membrane 120, and seals the internal space S.

[0073] In this embodiment, the packing 60 includes a first insulator 63 serving as the first packing 63 and a second insulator 64 serving as the second packing 64. The first packing 63 and the second packing 64 may be integrally formed. That is, the first packing 63 and the second packing 64 may be a single member. The packing 60 may also be integrally formed with at least one of the first insulator 63 and the second insulator 64 described above.

[0074] (First Gasket) The first gasket 63 is a gasket located near the separator 11 on one side dl of two adjacent separators 11. The first gasket 63 is located outside (on the outer periphery side) of the outer edge 120e of the ion exchange membrane 120. The first gasket 63 is sandwiched between the first inner surface 110a of the separator 11 located on the one side dl of the ion exchange membrane 120 and the second gasket 64, and seals a portion of the outer periphery side of the internal space S. In this embodiment, the first gasket 63 is sandwiched between the first insulator 47 attached to the first inner surface 110a and the second gasket 64. The first gasket 63 is annular (e.g., frame-shaped) along the outer edge 120e of the ion exchange membrane 120 and is formed into a ring shape that is slightly larger than the outer edge 120e of the ion exchange membrane 120.

[0075] (Second Gasket) The second gasket 64 is a gasket located near the separator 11 on the other side dr of two adjacent separators 11. The second gasket 64 is located outside the outer edge 120e of the ion exchange membrane 120. The second gasket 64 is sandwiched between the first gasket 63 and the second inner surface 110b of the separator 11 located on the other side dr of the ion exchange membrane 120, and seals a part of the outer peripheral side of the internal space S. The second gasket 64 is annular (for example, frame-shaped) along the outer edge 120e of the ion exchange membrane 120, and is formed into an annular shape that is one size larger than the outer edge 120e of the ion exchange membrane 120.

[0076] The detailed planar shape of the packing 60 will be described with reference to FIGS. 4, 6, and 7. As shown in the figures, the packing 60 includes a packing body 301, an arc-shaped packing 302, and a triangular packing 303. The packing body 301 is disposed outside the main flow path 204a, the first diffusion flow path 206, and the first convergence flow path 205, and has a rectangular ring shape when viewed from the first surface 201a. As shown in FIG. 6, one packing body 301 is provided on each side of the ion exchange membrane 120 in the thickness direction, and the ion exchange membrane 120 is sandwiched between a pair of separators 11. The width of the packing body 301 is, for example, 30 mm to 60 mm.

[0077] The arc-shaped packing 302 is integrally formed inside the packing body 301. The arc-shaped packing 302 extends across the first diffusion guide section 208 and the first convergence guide section 207, and has an arc shape that surrounds the first supply hole 203 and the first discharge hole 202 from the outer periphery. More specifically, as shown in Fig. 7 , the arc-shaped packing 302 faces the triangular packing 303 of another packing 60 in the thickness direction, with the ion exchange membrane 120 sandwiched between them.

[0078] Furthermore, the arc-shaped packing 302 is arranged to cover the first diffusion guide section 208 or the first convergence guide section 207 from the tip side via a plate-shaped member (not shown). The thickness dimension of the arc-shaped packing 302 is set to be larger than the gap between the tip of the first diffusion guide section 208 or the first convergence guide section 207 and the ion exchange membrane 120 before elastic deformation occurs due to assembly. Specifically, the thickness of the arc-shaped packing 302 is set to be 0.1 mm to 1.0 mm larger than the gap. Note that the apparent thickness after elastic deformation occurs after assembly is equivalent to the dimension of the gap. In other words, in the assembled state, the arc-shaped packing 302 is compressed from both sides in the thickness direction and elastically deforms, thereby generating high surface pressure between the separator 11 and the ion exchange membrane 120.

[0079] 7, the thickness of the triangular packing 303 is set to be larger than the thickness of the packing body 301 before elastic deformation. Note that the apparent thickness after assembly when elastic deformation occurs is equal to the thickness of the packing body 301. In other words, in the assembled state, the triangular packing 303 is compressed from both sides in the thickness direction and elastically deforms, thereby generating high surface pressure between the separator 11 and the ion exchange membrane 120.

[0080] The selection criteria for the material of the packing 60 are described below. In a cyclic load test with a total load of 500 N or more, the packing 60 is preferably formed of a material that can maintain an elastic compressive displacement of 90% or more 5 seconds after the load is released from 500 N after 3,000 cycles, where the elastic compressive displacement at a surface pressure of 500 N is defined as 100%. Furthermore, in a cyclic load test with a total load of 500 N or more, where the elastic compressive displacement at a maximum load of 500 N is defined as 100%, the packing 60 is preferably formed of a material that maintains an elastic compressive displacement of 99% or less 1 second after the load is released (see FIG. 8). An example of a material that exhibits these characteristics is ethylene propylene diene rubber with a hardness of 50 to 60.

[0081] (Effects) As described above, the ion exchange membrane 120 is sandwiched between the separator 11 on both sides in the thickness direction, and a flow path through which the electrolyte flows is formed on the surface of the separator 11. To prevent leakage of the electrolyte from the flow path, a packing 60 is interposed between the separator 11 and the ion exchange membrane 120.

[0082] When electrolyte is flowed through the flow path under high pressure, the surface pressure distribution between the separator and the insulating packing tends to vary depending on the position. Therefore, if an insulating packing with a uniform thickness, different from the above configuration, is used, a sufficient sealing effect cannot be obtained in the area where the surface pressure is low. As a result, there is a risk of electrolyte leakage. To solve this problem, the above-described configurations are adopted in this embodiment.

[0083] Here, because the separators 11 are fastened together using a bolt and nut fastening structure, a surface pressure of several MPa is applied between the separators 11 and the insulating packing (packing 60). When the electrolytic solution is flowed through the electrolytic cell 12 in this state, the above surface pressure decreases due to the fluid pressure, and in some places the surface pressure approaches zero. If an insulating packing with a uniform thickness were used, the gap between the packing 60 and the separator 11 would not be sufficiently small in areas where the surface pressure is low, which could result in leakage of the electrolytic solution. In particular, the surface pressure tends to be low in the arc packing 302 that contacts the first diffusion guide section 208 and the first convergence guide section 207, and in the triangular packing 303 that extends to the oblique sides of the first diffusion channel 206 and the first convergence channel 205. However, according to the above configuration, the thickness of the packing 60 is set to be thicker in areas where the surface pressure is low than in other areas. Specifically, the arc-shaped packing 302 is designed to have a thickness greater than the gap between the first diffusion guide section 208 and the ion exchange membrane 120 before elastic deformation, and the triangular packing 303 is designed to have a thickness greater than that of the packing body 301. This ensures sufficient surface pressure between each section and the separator 11. As a result, the sealing performance of the packing 60 is improved, further suppressing leakage of the electrolyte. This allows the electrolysis cell 12 to continue to operate stably over a long period of time.

[0084] According to the above configuration, the arc-shaped packing 302, which has a lower surface pressure, is set to have a thickness greater than that of the packing body 301. This ensures sufficient surface pressure between the arc-shaped packing 302 and the separator 11. As a result, the sealing performance of the packing 60 is improved, and leakage of the electrolyte can be further suppressed.

[0085] According to the above configuration, a material is selected for the insulating packing (packing 60) that can maintain a surface pressure of 96% or more of the full load one second after the load is released in a load load test. This allows the insulating packing to immediately recover its initial shape in response to changes in surface pressure during startup and shutdown of the electrolytic cell 12. This further reduces the possibility of electrolyte leakage during startup, operation, and shutdown. As a result, the electrolytic cell 12 can be operated stably for a long period of time.

[0086] According to the above configuration, a material is selected for the insulating packing, whose elastic compressive displacement 5 seconds after the load is released is 90% or less of that at full load in a load load test. This allows the insulating packing to quickly recover its initial shape in response to changes in surface pressure during startup and shutdown of the electrolytic cell 12. This further reduces the possibility of electrolyte leakage during startup, operation, and shutdown. As a result, the electrolytic cell 12 can be operated stably for a long period of time.

[0087] According to the above configuration, ethylene propylene diene rubber having a hardness of 50 or more and 60 or less is used as the material of the insulating packing. This allows the insulating packing to quickly recover its initial shape in response to changes in surface pressure during startup and shutdown of the electrolytic cell 12. This further reduces the possibility of electrolyte leakage during startup, operation, and shutdown. As a result, the electrolytic cell 12 can be operated stably for a long period of time.

[0088] According to the above configuration, it is possible to provide an electrolysis device 1 including an electrolysis cell 12 in which leakage of the electrolyte is further suppressed.

[0089] (Other Embodiments) Although the embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within the scope that does not deviate from the gist of the present disclosure are also included.

[0090] For example, a configuration shown in Fig. 9 can be adopted as a modified example of the separator 11. In the example shown in Fig. 9, a separator body 201 is formed with an accommodating groove 401 that accommodates a part of the packing body 301.

[0091] According to the above configuration, the separator body 201 is formed with an accommodation groove 401 that accommodates a portion of the packing body 301 in the thickness direction. This makes it possible to complicate the leakage path between the packing body 301 and the separator 11, thereby further minimizing the possibility of electrolyte leakage. In addition, this makes it easier to align the separator 11 and the packing body 301 when assembling the electrolytic cell 12. Similarly, this reduces the possibility of misalignment between the separator 11 and the packing body 301 during operation.

[0092] As a further modified example, the configuration shown in Fig. 10 may be employed. In the example shown in Fig. 10, the separator 11 is further provided with a first convex portion 501, a second convex portion 502, a third convex portion 503, and a fourth convex portion 504. The first convex portion 501 is provided in a portion of the periphery of the first discharge hole 202 and is spaced apart in the circumferential direction. The second convex portion 502 is provided in a portion of the periphery of the first supply hole 203 and is spaced apart in the circumferential direction. The third convex portion 503 and the fourth convex portion 504 are provided in the straight section 209 on the first discharge hole 202 side and the straight section 209 on the first supply hole 203 side, respectively. The third convex portion 503 and the fourth convex portion 504 are provided in a portion of the periphery of the straight section 209 and are spaced apart in the direction intersecting the extension direction of the straight section 209. That is, the third convex portion 503 and the fourth convex portion 504 are provided on the upstream side and the downstream side of the main flow path 204a, respectively.

[0093] According to this configuration, even if the ion exchange membrane 120 sinks toward one of the separators 11 for some reason, the first convex portion 501, the second convex portion 502, the third convex portion 503, and the fourth convex portion 504 can support the ion exchange membrane 120. This reduces the possibility that the ion exchange membrane 120 will clog the flow path, and also significantly reduces fluid pressure loss. It is also possible to adopt a configuration in which only the first convex portion 501 and the second convex portion 502 are provided, without the third convex portion 503 and the fourth convex portion 504. Conversely, it is also possible to provide only the third convex portion 503 and the fourth convex portion 504. The first convex portion 501 to the fourth convex portion 504 may be provided on a plate-shaped thickness adjustment plate laminated on the ion exchange membrane 120, rather than on the separator 11. In this case, it is only necessary to install a new thickness adjustment plate or to replace an existing thickness adjustment plate that does not have the first convex portion 501 to the fourth convex portion 504 with another thickness adjustment plate that does have the first convex portion 501 to the fourth convex portion 504.This results in significant cost benefits because it is not necessary to initially install the first convex portion 501 to the fourth convex portion 504 on the separator 11, which is an expensive part that is difficult to process.

[0094] <Additional Notes> The electrolytic cell 12 and the electrolytic device 1 described in each embodiment can be understood, for example, as follows.

[0095] (1) An electrolysis cell 12 according to a first aspect includes a pair of separators 11, an anion exchange membrane (ion exchange membrane 120) disposed between the pair of separators 11, and insulating packings (packings 60) provided between the anion exchange membrane and each of the separators 11. The separator 11 has a rectangular plate shape and includes a separator body 201 having a first surface facing one side in the thickness direction and a second surface facing the other side. The separator body 201 is formed on one diagonal line of the first surface of the separator body 201, and extends from the first surface toward the second surface. a main flow path (204a) formed in a region between the first supply hole (203) and the first discharge hole (202) and having a plurality of first groove portions (204) extending in the longitudinal direction of the separator body (201) and arranged at intervals in a width direction perpendicular to the longitudinal direction; a main flow path (204a) extending from the first supply hole (203) to the first groove portion (204) and recessed from the first surface side toward the second surface side, the dimension in the width direction gradually decreasing from the first supply hole (203) toward the first groove portion (204) as viewed from the first surface side; a trapezoidal first diffusion channel 206 that expands between the first groove portion 204 and the first discharge hole 202 and is recessed from the first surface side toward the second surface side, and whose dimension in the width direction gradually decreases from the first groove portion 204 toward the first discharge hole 202 as viewed from the first surface side; and a trapezoidal first convergence channel 205 that is provided in the first diffusion channel 206, protrudes from the second surface side toward the first surface side, and extends radially from the first supply hole 203 to guide the fluid from the first supply hole 203 to the first groove portion 204. and a first converging guide portion 207 that is provided in the first converging channel 205 and protrudes from the second surface side toward the first surface side and extends radially from the first discharge holes 202 to guide the fluid from the first groove portion 204 to the first discharge holes 202. The insulating packing includes a packing body 301 that is arranged outside the main channel 204 a, the first diffusion channel 206, and the first converging channel 205 and has an annular shape when viewed from the first surface side, and is formed inside the packing body 301 and includes the first diffusion guide portion 208,and the first converging and guiding portion 207, and surrounds the first supply hole 203 and the first discharge hole 202 from the outer periphery, respectively; and triangular packings 303 formed inside the packing body 301 and extending to the oblique sides of the first diffusion channel 206 and the first converging channel 205, respectively. The arc packing 302, before being sandwiched between the separator 11 and the anion exchange membrane and elastically deforming, has a thickness set to be larger than the gap between the first diffusion guide portion 208 and the anion exchange membrane.

[0096] According to the above configuration, the thickness of the packing 60 is set to be thicker in areas where the surface pressure is low than in other areas. This ensures sufficient surface pressure between the packing 60 and the separator 11 at each area. As a result, the sealing performance of the packing 60 is improved, and leakage of the electrolyte can be further suppressed.

[0097] (2) The electrolytic cell 12 according to the second aspect is the electrolytic cell 12 of (1), wherein the arc gasket 302 has a thickness set to be 0.1 mm to 1.0 mm larger than the gap between the first diffusion guide portion 208 and the anion exchange membrane (ion exchange membrane 120).

[0098] According to the above configuration, the arc-shaped packing 302, which has a lower surface pressure, is set to have a thickness greater than that of the packing body 301. This ensures sufficient surface pressure between the arc-shaped packing 302 and the separator 11. As a result, the sealing performance of the packing 60 is improved, and leakage of the electrolyte can be further suppressed.

[0099] (3) The electrolytic cell 12 according to a third aspect is the electrolytic cell 12 according to (1) or (2), wherein the separator body 201 has an accommodating groove 401 formed therein to accommodate a portion of the packing body 301.

[0100] According to the above configuration, the separator body 201 is formed with an accommodation groove 401 that accommodates a portion of the packing body 301 in the thickness direction. This makes it possible to complicate the leakage path between the packing body 301 and the separator 11, thereby further minimizing the possibility of electrolyte leakage.

[0101] (4) The electrolytic cell 12 according to a fourth aspect is the electrolytic cell 12 according to any one of the aspects (1) to (3), wherein the insulating packing is formed of a material such that, in a repeated load test with a total load of 500 N or more, when the elastic compressive displacement at a maximum load of 500 N is defined as 100%, the elastic compressive displacement 5 seconds after the load is released is 90% or less of the elastic compressive displacement at a load of 500 N.

[0102] According to the above configuration, a material is selected for the insulating packing, whose elastic compressive displacement 5 seconds after the load is released is 90% or less of that at full load in a load application test, thereby enabling the insulating packing to quickly recover its initial shape in response to changes in surface pressure when the electrolytic cell 12 is started and stopped.

[0103] (5) The electrolysis cell 12 according to a sixth aspect is the electrolysis cell 12 according to any one of (1) to (4), wherein the insulating packing (packing 60) is formed of ethylene propylene diene rubber having a hardness of 50 or more and 60 or less.

[0104] According to the above configuration, the insulating packing is made of ethylene propylene diene rubber having a hardness of 50 or more and 60 or less. This allows the insulating packing to quickly recover its initial shape in response to changes in surface pressure when the electrolysis cell 12 is started up and stopped.

[0105] (6) An electrolytic cell 12 according to a seventh aspect is the electrolytic cell 12 according to any one of the aspects (1) or (5), wherein the separator 11 further comprises a plurality of first convex portions 501 and second convex portions 502 that are provided at intervals in the circumferential direction along the peripheries of the first discharge holes 202 and the first supply holes 203, and a plurality of third convex portions 503 and fourth convex portions 504 that are provided on the upstream and downstream sides of the main flow path 204a, respectively, and are arranged at intervals in a direction intersecting the main flow path 204a.

[0106] According to the above configuration, even if the ion exchange membrane 120 sinks toward one of the separators 11 due to some factor, the first convex portion 501, the second convex portion 502, the third convex portion 503, and the fourth convex portion 504 can support the ion exchange membrane 120.

[0107] (7) The electrolysis device 1 according to the seventh aspect comprises an electrolysis cell 12 according to any one of aspects (1) to (6), an electrolyte solution supply unit 20 that supplies an electrolyte solution to the electrolysis cell 12, and a power supply unit 30 that applies a voltage to the electrolysis cell 12.

[0108] According to the above configuration, it is possible to provide an electrolysis device 1 including an electrolysis cell 12 in which leakage of the electrolyte is further suppressed.

[0109] According to the present disclosure, it is possible to provide an electrolysis cell and an electrolysis device in which leakage of electrolyte is further suppressed.

[0110] REFERENCE SIGNS LIST 1...Electrolysis device 10...Electrolysis cell stack 11...Separator 11a...First separator 11b...Second separator 11c...Third separator 11d...Fourth separator 11e...Fifth separator 11h1, 11h3...First insertion hole 11h2, 11h4...Second insertion hole 12...Electrolysis cell 12a...First electrolysis cell 12b...Second electrolysis cell 12c...Third electrolysis cell 12d...Fourth electrolysis cell 13, 13'...First flow path section 13o, 13o', 14o, 14o'...Outlet 14, 14'...Second flow path section 15...First structure 16...Second structure 20...Electrolyte solution supply section 21...Hydrogen gas-liquid separation device 22...First pump 23...Hydrogen recovery section 24...First electrolyte solution supply section DESCRIPTION OF SYMBOLS 26...Oxygen gas-liquid separator 27...Second pump 28...Oxygen recovery section 29...Second electrolyte supply section 30...Power supply section 65...First insulator 66...Second insulator 67...First end plate 68...Second end plate 63...First insulator 47h1, 47h2, 48h1, 48h2...Hole 64...Second insulator 50...Support section 51...First ion exchange membrane 52...Second ion exchange membrane 60...Packing 61...First current collector 62...Second current collector 110a...First inner surface 110b...Second inner surface 111...First end 112...Second end 120...Ion exchange membrane 120a...First surface 120b...Second surface 120e...Outer edge section 121...Cathode 121a...Cathode catalyst layer 121b...cathode current collector 122...anode 122a...anode catalyst layer 122b...anode current collector 130, 130', 140, 140'...tube portion 150, 150a, 150b, 150c, 160...cutout portion 151...mesh member 151a...first mesh member 151b...second mesh member 151c...third mesh member 151d...fourth mesh member 152,153...Conductive mesh 201...Separator body 201a...First surface 201b...Second surface 202...First discharge hole 203...First supply hole 204...First groove portion 205...First convergent flow path 206...First diffusion flow path 207...First convergent guide portion 208...First diffusion guide portion 209...Straight section 211...Second supply hole 210...Second discharge hole 212...Second groove portion 301...Packing body 302...Circular arc packing 303...Triangular packing 401...Accommodation groove 501...First convex portion 502...Second convex portion 503...Third convex portion 504...Fourth convex portion C...Central portion D1...First direction dl...One side dr...Other side Es...Electrolyte L1, L1', L2, L2'...Piping line S...Internal space S1...Gap Sa...Cathode chamber Sb...Anode chamber,

Claims

1. A separator comprising: a pair of separators; an anion exchange membrane disposed between the pair of separators; and insulating gaskets provided between the anion exchange membrane and each of the separators, wherein the separator comprises: a separator body in the shape of a rectangular plate having a first surface facing one side in a thickness direction and a second surface facing the other side; a first supply hole and a first discharge hole formed on one diagonal line of the separator body on the first surface and penetrating the separator body from the first surface toward the second surface; a main flow path formed in a region between the first supply hole and the first discharge hole, extending in the longitudinal direction of the separator body and having a plurality of first groove portions arranged at intervals in a width direction perpendicular to the longitudinal direction; and a trapezoidal first diffusion flow path extending between the first supply hole and the first groove portion and recessed from the first surface side toward the second surface side, the dimension in the width direction gradually increasing from the first supply hole toward the first groove portion as viewed from the first surface side. the insulating packing comprises: a trapezoidal first convergent flow path that extends between the first groove portion and the first discharge hole, is recessed from the first surface side toward the second surface side, and has a dimension in the width direction that gradually decreases from the first groove portion to the first discharge hole as viewed from the first surface side; a first diffusion guide portion that is provided in the first diffusion flow path, protrudes from the second surface side toward the first surface side, and extends radially from the first supply hole to guide the fluid from the first supply hole to the first groove portion; and a first convergent guide portion that is provided in the first convergent flow path, protrudes from the second surface side toward the first surface side, and extends radially from the first discharge hole to guide the fluid from the first groove portion to the first discharge hole, and the insulating packing comprises: a packing body that is arranged outside the main flow path, the first diffusion flow path, and the first convergent flow path, and is annular as viewed from the first surface side; an arc-shaped arc packing formed inside the packing body, extending so as to straddle the first diffusion guide portion and the first convergence guide portion, and surrounding the first supply hole and the first discharge hole from the outer periphery, and a triangular packing formed inside the packing body, extending to the oblique sides of the first diffusion flow path and the first convergence flow path,An electrolysis cell in which the arc-shaped packing, when sandwiched between the separator and the anion exchange membrane and before elastic deformation, is set to have a thickness greater than the gap between the first diffusion guide portion and the anion exchange membrane.

2. The electrolytic cell according to claim 1, wherein the arcuate packing has a thickness set to be 0.1 mm to 1.0 mm larger than the gap between the first diffusion guide portion and the anion exchange membrane.

3. The electrolytic cell according to claim 1 or 2, wherein the separator body has an accommodation groove formed therein for accommodating a part of the packing body.

4. An electrolytic cell according to claim 1 or 2, wherein the insulating packing is formed from a material such that, in a repeated load test with a total load of 500 N or more, the elastic compressive displacement at a maximum load of 500 N is defined as 100%, and the elastic compressive displacement 5 seconds after the load is released is 90% or less of the elastic compressive displacement at a load of 500 N.

5. The electrolytic cell according to claim 1 or 2, wherein the insulating packing is made of ethylene propylene diene rubber having a hardness of 50 or more and 60 or less.

6. An electrolytic cell according to claim 1 or 2, wherein the separator further comprises a plurality of first convex portions and second convex portions spaced apart in the circumferential direction along the peripheries of the first discharge hole and the first supply hole, and a plurality of third convex portions and fourth convex portions provided on the upstream and downstream sides of the main flow path, respectively, and arranged at intervals in a direction intersecting the main flow path.

7. An electrolysis device comprising: the electrolysis cell according to claim 1 or 2; an electrolyte supply unit that supplies an electrolyte to the electrolysis cell; and a power supply unit that applies a voltage to the electrolysis cell.

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