Electrolytic cell and electrolytic device

Abstract

Provided is an electrolytic cell and an electrolytic device in which leakage of an electrolyte is further suppressed. [Solution] In the electrolytic cell, the insulating gasket has a ring-shaped gasket body, an arc-shaped arc gasket formed inside the gasket body and surrounding the first supply hole and the first discharge hole from the outer periphery, and a triangular gasket, and the arc gasket, before being sandwiched between the separator and the anion exchange membrane and elastically deformed, is set to a thickness greater than the gap between the first diffusion guide portion and the anion exchange membrane, and the triangular gasket is set to a thickness greater than the gasket body.

Description

[Technical field]

[0001] The present disclosure relates to electrolysis cells and electrolysis devices. [Background technology]

[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 two 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. In order 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 according to Patent Document 1 below, a resin material with a uniform thickness is used as the sealing member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-191886 Summary of the Invention [Problem to be solved by the invention]

[0005] When the electrolyte is passed 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. 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. [Means for solving the problem]

[0007] In order to solve the above problems, an electrolysis cell according to the present disclosure includes a pair of separators, an anion exchange membrane disposed between the pair of separators, and an insulating packing provided between the anion exchange membrane and each of the separators, Extends in a longitudinal direction and a width direction perpendicular to the longitudinal direction a separator body having a rectangular plate shape and 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 to the second surface; the first supply hole is provided in a portion on one side in the longitudinal direction and one side in the width direction, the first discharge hole is provided in the other side in the longitudinal direction and the other side in the width direction, the separator has: a main flow path formed in a region between the first supply hole and the first discharge hole, recessed from the first surface side toward the second surface side and having a plurality of first groove portions arranged at intervals in the width direction; a first diffusion flow path formed in a region where the first supply hole exists, recessed from the first surface side toward the second surface side, with the first supply hole opening therein and connected to the main flow path from the one side in the longitudinal direction across the width direction; a first convergence flow channel formed in a region where the first discharge hole is present, recessed from the first surface side toward the second surface side, with the first discharge hole open, and connected to the main flow channel from the other longitudinal side across the width direction, wherein the first diffusion flow channel has: a first side portion which is an edge portion of the first diffusion flow channel on one longitudinal side and extends in the width direction; a second side portion which is an edge portion of the diffusion flow channel on one width direction side and extends in the longitudinal direction; and an oblique side which is an edge portion of the diffusion flow channel on the other width direction side and extends to the other width direction side as it approaches the other longitudinal side, wherein the first convergence flow channel has: a first side portion which is an edge portion of the first convergence flow channel on the other longitudinal side and extends in the width direction; a second side portion which is an edge portion of the first convergence flow channel on the other width direction side and extends in the longitudinal direction; and an oblique side which is an edge portion of the first convergence flow channel on one width direction side and extends to the one width direction side as it approaches the one longitudinal side, wherein the separator a first diffusion passage provided in the first diffusion channel, 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; Multiple a first diffusion guide portion provided in the first convergence flow passage, 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; Multiple a first convergence guide portion, and the insulating packing is disposed on an outer side of the main flow path, the first diffusion flow path, and the first convergence flow path. and surrounding the main flow path, the first diffusion flow path, and the first convergence flow path as viewed from the first surface side. A ring-shaped packing body and an inner surface of the packing body And multiple The first diffusion guide, and Multiple The first convergence guide portion and both ends are connected to the packing body,a pair of arc-shaped packings each surrounding the first supply hole and the first discharge hole from an outer periphery, and a triangular packing formed inside the packing body and extending to the first diffusion flow passage and the first convergence flow passage, respectively; The thickness of the packing body is determined by sandwiching the packing body between the separator and the anion exchange membrane. The gap is set larger than the gap between the first diffusion guide portion and the anion exchange membrane, The thickness of the triangular gasket before it is sandwiched between the separator and the anion exchange membrane and elastically deformed is greater than the thickness of the gasket body before it is sandwiched between the separator and the anion exchange membrane and elastically deformed.

[0008] The electrolysis device according to the present disclosure includes the electrolysis cell described above, 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. Effect of the Invention

[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. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating a configuration of an electrolysis device according to an embodiment of the present disclosure. [Diagram 2] FIG. 1 is a schematic cross-sectional view showing a configuration of an electrolysis cell according to an embodiment of the present disclosure. [Diagram 3] FIG. 1 is an exploded perspective view showing a configuration of an electrolysis cell according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a plan view showing the configuration of a separator and an insulating gasket according to an embodiment of the present disclosure. [Diagram 5] FIG. 1 is a schematic cross-sectional view illustrating a configuration of an electrolysis cell stack according to an embodiment of the present disclosure. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] 1 is a graph showing a relationship between the material of an insulating packing according to an embodiment of the present disclosure and an example of a result of a load test. [Figure 9]FIG. 11 is a cross-sectional view showing a modified example of the separator according to the embodiment of the present disclosure. [Figure 10] FIG. 11 is a plan view showing a further modified example of the separator according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 are denoted by the same reference numerals. In this specification, "facing" means that two members overlap when viewed in a certain direction, and may also include a case where another member (e.g., another layer) exists between the two members.

[0013] First, referring to FIG. 2, the Z direction, the X direction, and the Y direction are defined. The Z direction is the direction from the first separator 11a to the second separator 11b (to the right in FIG. 2), which will be described later. The X direction is a direction that intersects (e.g., perpendicular to) the Z direction, and is a direction from the center C of the electrolysis cell 12 to one end of the electrolysis cell 12 (the up-down direction in FIG. 2). The X direction is, for example, a vertical direction. The Y direction is a direction that intersects (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 "external size" means the external size when viewed in the Z direction.

[0014] FIG 1 is a schematic diagram showing the overall configuration of an electrolysis device 1 of a first embodiment. The electrolysis device 1 is, for example, a device that generates hydrogen by electrolyzing water contained in an electrolytic 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 electrolytic solution Es supplied from the outside. 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, a case where the electrolysis cell stack 10 is formed by arranging five separators 11 and four electrolysis cells 12 will be described as an example (see FIG. 6 ).

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

[0018] As shown in FIG. 5, the electrolytic cell stack 10 includes a plurality of (four) electrolytic cells 12 which, together with the separators 11, form a cathode chamber Sa and an anode chamber Sb, a first flow path section 13, 13' (described later) that allows 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 a second flow path section 14, 14' (described later) that allows the electrolytic solution that has completed the reaction in the cathode chamber Sa and the anode chamber Sb to flow (return) toward 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 the above numbers. 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 supply section) The electrolyte supply unit 20 is a supply unit that supplies the electrolyte Es to each electrolytic cell 12. The electrolyte Es is, for example, pure water or an alkaline aqueous solution. The electrolyte supply unit 20 includes a cathode side supply unit 20a and an anode side supply unit 20b.

[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. The second pump 27 is provided in the middle of 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-gas-liquid separator 26 receives the electrolytic solution Es containing oxygen produced in the electrolytic cell 12 from the electrolytic cell 12. The oxygen-gas-liquid separator 26 has a gas-liquid separation section 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 section 28. The oxygen-gas-liquid separator 26 is replenished with the electrolytic solution Es from a second electrolytic solution supply section 29.

[0026] (Power supply part) 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 electrolyte Es between the anode 122 and the cathode 121 of each electrolytic cell 12.

[0027] (Electrolysis cell stack configuration) Next, the electrolysis cell stack 10 will be described in detail with reference to Fig. 2 to Fig. 6. Fig. 2 is a schematic diagram of 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 a first direction D1 (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 an internal space S in which the electrolysis 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] 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 first surface 201a and second surface 201b (described later) are point symmetric with respect to the geometric center of gravity of separator 11. The configuration of first surface 201a 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 convergent flow path 205, a first diffusion flow path 206, a first convergent 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] First supply hole 203 and first discharge hole 202 are disposed at the corners along one of two diagonals connecting the corners of rectangular separator body 201. First supply hole 203 and first discharge hole 202 are circular holes penetrating separator body 201 from the first surface side to the second surface side. The diameter of first discharge hole 202 is set to be larger than the diameter of first supply hole 203. Second supply hole 211 and second discharge hole 210 are provided at the respective corners along the other of the two diagonals connecting the corners of separator body 201.

[0033] The first groove portion 204, the first diffusion channel 206, the first convergence channel 205, the first diffusion guide portion 208, and the first convergence guide portion 207 are formed only on the first surface 201a. The first groove portion 204 is formed in a region between the first supply hole 203 and the first discharge hole 202. The first groove portion 204 extends in the longitudinal direction of the separator body 201, and a plurality of first groove portions 204 are arranged at intervals in the width direction perpendicular to the longitudinal direction. The first groove portion 204 has a rectangular cross section recessed from the first surface 201a side toward the second surface 201b side.

[0034] The first diffusion channel 206 forms a channel by expanding between the first supply hole 203 and the first groove portion 204 and recessing from the first surface 201a side toward the second surface 201b side. The first diffusion channel 206 has a trapezoidal shape in which the dimension in the width direction gradually increases from the first supply hole 203 toward the first groove portion 204 when viewed from the first surface 201a side. More specifically, the first diffusion channel 206 is defined by a first side portion 206a extending in the width direction from the edge of the first supply hole 203, a second side portion 206b extending in a direction perpendicular to the first side portion 206a (the above-mentioned longitudinal direction), and an oblique side 206c facing the second side portion 206b in the width direction. The oblique side 206c extends in a direction away from the first supply hole 203 as it moves from one side to the other side in the longitudinal direction. The angle that the oblique side 206c makes 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 flow 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 farther away the first diffusion guide portions 208 are from the first supply hole 203, the smaller the angle they form with respect to the width direction. Also, the farther away the first diffusion guide portions 208 are, the larger their longitudinal dimensions become.

[0036] A straight section 209 is provided between the first convergence channel 205 and the first groove portion 204. In the straight section 209, the dimension in the width direction is constant over the entire area in the longitudinal direction. Moreover, the dimension in the longitudinal direction of the straight section 209 is desirably about 25 mm.

[0037] First convergent channel 205 forms a channel by expanding between first groove portion 204 and first discharge hole 202 and recessing from first surface 201a toward second surface 201b. First convergent channel 205 has a trapezoidal shape whose width gradually increases from first discharge hole 202 toward first groove portion 204 when viewed from first surface 201a.

[0038] A first convergent guide portion 207 is provided in the first convergent flow path 205. The first convergent guide portion 207 protrudes from the first surface 201a, and a plurality of first convergent guide portions 207 are provided radially from the first discharge hole 202. The more the first convergent guide portion 207 is away from the first discharge hole 202, the smaller the angle the first convergent guide portion 207 forms with respect to the width direction. Also, the more the first convergent guide portion 207 is away, the larger the longitudinal dimension of the first convergent guide portion 207 becomes.

[0039] (Electrolysis Cell) The electrolysis cell (MEA: Membrane Electrode Assembly) 12 is a structure in which an ion exchange membrane, a catalyst, a power supply, and the like are stacked and assembled. As shown in FIG. 2 or FIG. 5, the electrolysis cells 12 are disposed between two adjacent separators 11, one by one, and connect the two adjacent separators 11 to each other in a first direction D1. Thus, the electrolysis cell 12 is located in an internal space S between the two adjacent separators 11. The electrolysis cell 12 has, 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) that is different from the above example and has proton conductivity.

[0041] The ion exchange membrane 120 is, for example, a rectangular sheet. The outer size of the ion exchange membrane 120 is, for example, smaller than the outer size of the separator 11 adjacent to the ion exchange membrane 120 in the first direction D1. The ion exchange membrane 120 is disposed between the two separators 11 adjacent to the ion exchange membrane 120 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 to 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 electrolysis 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 electrolysis 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 electrolysis 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 electrolysis 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 electrolysis 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 electrolysis 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 (Chemical Formula 1) occurs, and hydrogen is produced from the electrolytic solution Es. In this specification, "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. 2H2O+2e - →H2+2OH - …(C1)

[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 electrolyte Es. 2OH - →1 / 2O2+H2O+2e - …(Case 2)

[0046] As a result, when viewed as a whole in the electrolysis cell 12, the chemical reaction shown in Chemical Formula 3 below occurs. H2O→H2+1 / 2O2…(Chem.3)

[0047] The ion exchange membrane 120 may be an example of a membrane with high ion conductivity, which contains 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 be an example of a membrane with high oxidation resistance, which contains 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 has, 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 described above. 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 is 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 a 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 a 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 material of the cathode catalyst layer 121a may be any material that promotes the chemical reaction in the cathode chamber Sa described above, and various materials can be used. For example, the cathode catalyst layer 121a includes one or more of nickel, nickel alloy, cerium oxide, lanthanum oxide, and platinum. In this specification, the "XX oxide" may include other materials other than XX and oxygen. In addition to the above-mentioned materials, the cathode catalyst layer 121a may include other materials such as carbon. 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 supplier 121b is an electrical connection part that transmits the voltage applied to the separator 11 to the cathode catalyst layer 121a. The cathode power supplier 121b is disposed in the cathode chamber Sa. The cathode power supplier 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 joined 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 joined 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 joined 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 joined 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 joined to the first inner surface 110a and the cathode catalyst layer 121a of the fourth separator 11d.

[0054] The cathode power supply body 121b has a structure through which the electrolyte Es and gas can pass. The cathode power supply body 121b is formed of, for example, a metal mesh structure, a sintered body, or a fiber. In this embodiment, the outer size of the cathode power supply body 121b is, for example, the same as the outer 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 described above. The anode catalyst layer 122a is, for example, in the form of a rectangular sheet. The anode catalyst layer 122a is disposed in the anode chamber Sb and is fixed to the ion exchange membrane 120 by, for example, surface pressure bonding.

[0057] Specifically, the anode catalyst layer 122a of the first electrolysis cell 12a and the anode catalyst layer 122a of the third electrolysis cell 12c are fixed, for example, by surface pressure bonding, to the second surface 120b of the ion exchange membrane 120. The anode catalyst layer 122a of the second electrolysis cell 12b and the anode catalyst layer 122a of the fourth electrolysis cell 12d are fixed, for example, by surface pressure bonding, to the first surface 120a of the ion exchange membrane 120. 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 material of the anode catalyst layer 122a may be any material that promotes the chemical reaction in the anode chamber Sb described above, and various materials can be used. For example, the anode catalyst layer 122a includes one or more of nickel, nickel alloy, nickel oxide, copper oxide, iridium oxide, niobium oxide, lead oxide, or bismuth oxide. As described above, the "XX oxide" in this specification may include other materials other than XX and oxygen. For example, the "nickel oxide" may include other materials such as iron and cobalt in addition to nickel and oxygen. Also, the "copper oxide" may include other materials such as cobalt in addition to copper and oxygen. The "iridium oxide" may include other materials such as ruthenium in addition to iridium and oxygen. The "lead oxide" may include other materials such as ruthenium in addition to lead and oxygen. The "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 electrolysis cell 12a is joined 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 electrolysis cell 12c is joined to the second inner surface 110b and the anode catalyst layer 122a of the fourth separator 11d. The cathode power supply 121b of the second electrolysis cell 12b is joined 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 electrolysis cell 12d is joined to the second inner surface 110b and the cathode catalyst layer 121a of the fifth separator 11e.

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

[0062] Fig. 3 is an exploded perspective view showing a part of the electrolysis cell stack 10. In addition to the above-mentioned components, the electrolysis cell stack 10 has, 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 Fig. 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 a 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. A 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 of, for example, a metal plate member (for example, 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 (for example, 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-mentioned components, a first insulator 63 and a second insulator 64, for example.

[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 outer sizes of the cathode catalyst layer 121a and the anode catalyst layer 122a and the cathode power supply 121b and the anode power supply 122b.

[0071] (Second edge body) The second insulator 64, like the first insulator 47, 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 outer sizes of the anode catalyst layer 122a and the cathode catalyst layer 121a and the anode power feeder 122b and the cathode power feeder 121b.

[0072] (rubber seal) 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 as the first packing 63 and a second insulator 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 one member. The packing 60 may be integrally formed with at least one of the first insulator 63 and the second insulator 64 described above.

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

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

[0076] A detailed planar shape of the packing 60 will be described with reference to Figs. 4, 6, and 7. As shown in Figs. 4, 6, and 7, the packing 60 has a packing body 301, an arc 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 side. As shown in Fig. 6, the packing bodies 301 are provided on both sides of the ion exchange membrane 120 in the thickness direction, respectively, and sandwich the ion exchange membrane 120 between a pair of separators 11. The width dimension 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 so as to straddle the first diffusion guide portion 208 and the first convergence guide portion 207, and has an arc shape surrounding 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 therebetween.

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

[0079] 7, the thickness dimension of the triangular packing 303 is set to be larger than the thickness dimension of the packing body 301 before elastic deformation. The apparent thickness after assembly and elastic deformation 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 deformed, 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 will be described below. In a repeated load test with a total load of 500N or more, after 3000 cycles, the packing 60 is desirably formed of a material capable of maintaining an elastic compression displacement of 90% or more 5 seconds after the load is removed from 500N, where the elastic compression displacement at a surface pressure of 500N is defined as 100%. In addition, in a repeated load test with a total load of 500N or more, where the elastic compression displacement at a maximum load of 500N is defined as 100%, the packing 60 is desirably formed of a material whose elastic compression displacement 1 second after the load is removed is 99% or less of the elastic compression displacement at a load of 500N (see FIG. 8). An example of a material having such characteristics is ethylene propylene diene rubber with a hardness of 50 to 60.

[0081] (Action and effect) 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. A packing 60 is interposed between the separator 11 and the ion exchange membrane 120 to prevent leakage of the electrolyte from the flow path.

[0082] Here, when the electrolyte is flowed 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. 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 leakage of the electrolyte. In order to solve this problem, the above-mentioned configurations are adopted in this embodiment.

[0083] Here, since the separators 11 are fixed to each other by a fastening structure of bolts and nuts, a surface pressure of about several MPa is applied between the separators 11 and the insulating packing (packing 60). In this state, when the electrolytic solution is flowed through the electrolytic cell 12, the above surface pressure is reduced by the pressure of the fluid, and the surface pressure approaches zero in some places. If an insulating packing with a uniform thickness is used, the gap between the packing 60 and the separator 11 is not sufficiently small in the area where the surface pressure is low, and there is a risk of 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 flow path 206 and the first convergence flow path 205. However, according to the above configuration, the thickness of the packing 60 is set to be thicker than other parts in the area where the surface pressure is low. Specifically, the arcuate packing 302 is set to have a thickness greater than the gap between the first diffusion guide portion 208 and the ion exchange membrane 120 before elastic deformation, and the triangular packing 303 is set to have a thickness greater than that of the packing body 301. This ensures sufficient surface pressure between the separator 11 at each portion. As a result, the sealing performance of the packing 60 is improved, and leakage of the electrolyte can be further suppressed. This makes it possible to continue stable operation of the electrolytic cell 12 for 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 capable of maintaining a surface pressure of 96% or more of the full load 1 second after the load is removed in a load load test is selected as the insulating packing (packing 60). This allows the insulating packing to immediately recover its initial shape in response to changes in surface pressure when the electrolytic cell 12 is started up and stopped. This makes it possible to further reduce the possibility of electrolyte leakage regardless of whether the electrolytic cell 12 is started up, in operation, or stopped. 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 compression displacement 5 seconds after the load is removed is 90% or less of that at full load in a load load test. This allows the insulating packing to immediately recover its initial shape in response to changes in surface pressure when the electrolytic cell 12 is started up and stopped. This makes it possible to further reduce the possibility of electrolyte leakage regardless of whether the electrolytic cell 12 is started up, in operation, or stopped. 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 immediately recover its initial shape in response to changes in surface pressure when the electrolytic cell 12 is started up and stopped. This makes it possible to further reduce the possibility of electrolyte leakage regardless of whether the electrolytic cell 12 is started up, in operation, or stopped. 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 that do not depart from the gist of the present disclosure are also included.

[0090] For example, a modified example of the separator 11 may have a configuration shown in Fig. 9. In the example shown in the figure, a separator body 201 is formed with an accommodating groove 401 for accommodating 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 part 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 reducing the possibility of leakage of the electrolyte. In addition, it is possible to easily align the separator 11 and the packing body 301 when assembling the electrolytic cell 12. Similarly, it is possible to reduce 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 adopted. In the example shown in the figure, 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 part of the peripheral portion of the first discharge hole 202 with a plurality of portions spaced apart in the circumferential direction. The second convex portion 502 is provided in a part of the peripheral portion of the first supply hole 203 with a plurality of portions 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 plurality of portions spaced apart in a 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, respectively, of the main flow path 204a.

[0093] According to this configuration, even if the ion exchange membrane 120 sinks toward one of the separators 11 due to 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. Therefore, the possibility that the ion exchange membrane 120 blocks the flow path is reduced, and the pressure loss of the fluid can be significantly reduced. It is also possible to adopt a configuration in which only the first convex portion 501 and the second convex portion 502 are provided, and the third convex portion 503 and the fourth convex portion 504 are not provided. Conversely, it is also possible to provide only the third convex portion 503 and the fourth convex portion 504. It is also possible that the first convex portion 501 to the fourth convex portion 504 are 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 has the first convex portion 501 to the fourth convex portion 504. Since 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, a significant cost benefit can be obtained.

[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 embodiment includes a pair of separators 11, an anion exchange membrane (ion exchange membrane 120) disposed between the pair of separators 11, and an insulating packing (packing 60) provided between the anion exchange membrane and each of the separators 11. The separator 11 has a rectangular plate shape and a separator body 201 having a first surface facing one side in a 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 is inclined from the first surface to the second surface. a first supply hole 203 and a first discharge hole 202 penetrating a main body 201; a main flow path 204a formed in a region between the first supply hole 203 and the first discharge hole 202, extending in the longitudinal direction of the separator main body 201 and having a plurality of first groove portions 204 arranged at intervals in a width direction perpendicular to the longitudinal direction; and a first groove portion 204 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 flow 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 a trapezoidal first convergence flow channel 205 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 flow channel 205 that is provided within the first diffusion flow channel 206, protrudes from the second surface side toward the first surface side, and extends radially from the first supply hole 203 to guide a fluid from the first supply hole 203 to the first groove portion 204. the first diffusion guide portion 208 is disposed in the first convergent flow passage 205 and protrudes from the second surface side toward the first surface side, and extends radially from the first discharge hole 202 to guide the fluid from the first groove portion 204 to the first discharge hole 202. The insulating packing is disposed outside the main flow passage 204 a, the first diffusion flow passage 206, and the first convergent flow passage 205 and has an annular shape when viewed from the first surface side;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 a triangular packing 303 formed inside the packing body 301 and extending to the oblique sides of the first diffusion flow path 206 and the first converging flow path 205, respectively. The arc packing 302, before being sandwiched between the separator 11 and the anion exchange membrane and elastically deformed, 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 the area where the surface pressure is low than in other parts. This ensures sufficient surface pressure between the packing 60 and the separator 11 at each part. 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 is formed with an accommodation groove 401 for accommodating a part of the packing body 301.

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

[0101] (4) The electrolytic cell 12 of the fourth aspect is an electrolytic cell 12 of any one of the aspects (1) to (3), and is formed from a material in which, in a repeated load test with a total load of 500 N or more, when the elastic compression displacement at the maximum load of 500 N is defined as 100%, the elastic compression displacement 5 seconds after the load is removed is 90% or less of the elastic compression displacement at a load of 500 N.

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

[0103] (5) The electrolytic cell 12 according to a sixth aspect is the electrolytic cell 12 according to any one of the aspects (1) to (4), wherein the insulating gasket (gasket 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 enables the insulating packing to immediately recover its initial shape in response to changes in surface pressure when the electrolysis cell 12 is started up and stopped.

[0105] (6) The 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 has a plurality of first convex portions 501 and second convex portions 502 provided at intervals in the circumferential direction along the periphery of the first discharge hole 202 and the first supply hole 203, and a plurality of third convex portions 503 and fourth convex portions 504 provided on the upstream and downstream sides, respectively, of the main flow path 204a and 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 supply unit 20 that supplies electrolyte to the electrolysis cell 12, and a power supply unit 30 that applies 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. [Explanation of symbols]

[0109] 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 supply section 21...Hydrogen gas-liquid separation device 22...First pump 23...Hydrogen recovery section 24...First electrolyte supply section 26...oxygen gas-liquid separation device 27...second pump 28...oxygen recovery section 29...second electrolyte supply section 30...power supply section 65...first insulating material 66...second insulating material 67...first end plate 68...second end plate 63...first insulator 47h1, 47h2, 48h1, 48h2...holes 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 portion 112...second end portion 120...ion exchange membrane 120a...first surface 120b...second surface 120e...outer edge portion 121...cathode 121a...cathode catalyst layer 121b...cathode power supply body 122...anode 122a...anode catalyst layer 122b...anode power supply body 130, 130', 140, 140'...tube portion 150, 150a, 150b, 150c, 160...notch 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...Center portion D1...First direction dl...One side dr...Other side Es...Electrolyte L1,L1',L2,L2'...Pipe line S...Internal space S1...Gap Sa...Cathode chamber Sb…Anode chamber,

Claims

1. A pair of separators; an anion exchange membrane disposed between the pair of separators; and an insulating packing provided between the anion exchange membrane and each of the separators, The separator is a separator body having a rectangular plate shape extending in a longitudinal direction and a width direction perpendicular to the longitudinal direction, the 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 to the second surface; having the first supply hole is provided in a portion on one side in the longitudinal direction and one side in the width direction, The first discharge hole is provided on the other side in the longitudinal direction and on the other side in the width direction, The separator is a main flow path formed in a region between the first supply hole and the first discharge hole, the main flow path having a plurality of first groove portions recessed from the first surface side toward the second surface side and arranged at intervals in the width direction; a first diffusion flow path formed in a region where the first supply hole exists, recessed from the first surface side toward the second surface side, with the first supply hole opening therein, and connected to the main flow path from one side in the longitudinal direction across the width direction; a first convergence flow path formed in a region where the first discharge hole exists, recessed from the first surface side toward the second surface side, with the first discharge hole opening therein, and connected to the main flow path from the other side in the longitudinal direction across the width direction; having The first diffusion channel is a first side portion that is an edge portion on one side in the longitudinal direction of the first diffusion channel and extends in the width direction; a second side portion that is an edge portion on one side in a width direction of the diffusion channel and extends in the longitudinal direction; a slanting side that is an edge portion on the other side of the width direction of the diffusion flow path and extends toward the other side of the width direction as it approaches the other side of the longitudinal direction; having The first convergent flow channel is a first side portion that is an edge portion on the other side in the longitudinal direction of the first convergent flow channel and extends in the width direction; a second side portion that is an edge portion on the other side in the width direction of the first convergent flow channel and extends in the longitudinal direction; a slant side that is an edge portion on one side in a width direction of the first convergent flow path and extends toward the one side in the width direction as it approaches the one side in the longitudinal direction; having The separator is a plurality of first diffusion guides provided in the first diffusion flow channel, 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; a plurality of first convergent guide portions 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; having The insulating packing is a packing body that is disposed on an outer edge portion of the first surface, which is an area outside the main flow path, the first diffusion flow path, and the first convergence flow path, and has an annular shape surrounding the main flow path, the first diffusion flow path, and the first convergence flow path when viewed from the first surface side; a pair of arc-shaped packings extending inside the packing body so as to contact tips of the first diffusion guide portions and the first convergence guide portions, both ends of which are connected to the packing body, and each of which forms an arc shape surrounding the first supply hole and the first discharge hole from an outer circumferential side; a triangular packing formed inside the packing body and extending to the first diffusion flow passage and the first convergence flow passage; having a thickness of the arc-shaped packing before being sandwiched between the separator and the anion exchange membrane and elastically deformed is set to be larger than a gap between the first diffusion guide portion and the anion exchange membrane that is defined by the packing body being sandwiched between the separator and the anion exchange membrane, An electrolytic cell in which the thickness of the triangular gasket before it is sandwiched between the separator and the anion exchange membrane and elastically deformed is greater than the thickness of the gasket body before it is sandwiched between the separator and the anion exchange membrane and elastically deformed.

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

4. 3. The electrolytic cell according to claim 1 or 2, which is formed from a material in which, 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 removed is 90% or less of the elastic compressive displacement at a load of 500 N.

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

6. the separator further includes a plurality of first convex portions and a plurality of second convex portions provided at intervals in a circumferential direction along peripheral edges of the first discharge hole and the first supply hole, and a plurality of third convex portions and a plurality of fourth convex portions provided on the upstream side and the downstream side of the main flow path, respectively, and arranged at intervals in a direction intersecting the main flow path, 3 . The electrolysis cell according to claim 1 , wherein the first convex portion, the second convex portion, the third convex portion, and the fourth convex portion are each capable of supporting the separator in a thickness direction.

7. The electrolytic cell according to claim 1 or 2; an electrolyte supply unit for supplying an electrolyte to the electrolytic cell; A power supply unit that applies a voltage to the electrolytic cell; An electrolysis device comprising:

Images