Electrolytic cell

Abstract

To provide an electrolytic cell capable of suitably holding a conductive elastic body.SOLUTION: There is provided the electrolytic cell in one embodiment that includes an anode 100, a cathode 200, a diaphragm 300 arranged between the anode and the cathode, a conductive elastic body 400 provided on a back side of one of the anode and the cathode, an electrode base 500 provided on a back side of the conductive elastic body and having a plurality of openings, and an attachment member capable of attaching the conductive elastic body to the electrode base, in which the attachment member comprises a plate-shaped main body portion 710 provided on a front side of the conductive elastic body, and a first bent portion 721 continuing from a predetermined portion of the plate-shaped main body portion and a second bent portion 722, facing the first bent portion while being spaced apart, and further in a cross-sectional view, at least the plate-like main body portion and the conductive elastic body directly face each other, and the bent portion and the electrode base can directly face each other.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electrolytic cell, and more particularly to an electrolytic cell comprising an anode, a cathode, and a diaphragm. [Background technology]

[0002] Electrolysis is currently used in a variety of industries. Electrolysis, or electrolysis, is performed using an electrolytic cell. An electrolytic cell is equipped with at least an anode and a cathode. For example, an electrolytic cell that electrolyzes a sodium chloride solution can extract chlorine, hydrogen, and sodium hydroxide (also known as caustic soda), and is used to produce raw materials that are the basis of the chemical industry. It is also used to electrolyze alkaline solutions used in hydrogen production.

[0003] In electrolytic cells, a diaphragm is often further provided to prevent mixing of the substances produced at the anode and the cathode. The process of electrolyzing a sodium chloride solution using an ion exchange membrane as a diaphragm is also called "ion exchange membrane chlor-alkali electrolysis."

[0004] In the field of ion-exchange membrane chloride electrolysis, there are various types of electrolytic cells, but the zero-gap type is becoming the mainstream. In a zero-gap electrolytic cell, the anode, diaphragm, and cathode are closely attached to each other, reducing the distance between the electrodes and reducing the electrolyte resistance. Therefore, the use of such an electrolytic cell leads to reduced power consumption. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 009241 [Patent Document 2] International Publication No. 2020 / 022440 [Patent Document 3] Patent No. 3686270 [Patent Document 4] Patent No. 5493787 Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors have found that there are still areas in which zero-gap electrolytic cells can be improved. In addition to the above-mentioned anode, cathode, and diaphragm, zero-gap electrolytic cells further include a conductive elastic body provided on the back side of one of the anode and cathode electrodes (e.g., the cathode), and a current collecting plate serving as an electrode base provided on the back side of the conductive elastic body. In this regard, there are two modes for holding the conductive elastic body: one that uses a fixing pin and one that uses welding.

[0007] However, in the former embodiment using a fixing pin, the fixing pin has a configuration in which its main shaft portion extends in one direction from the electrode side to the current collector side, where the electrodes are arranged opposite each other, and therefore there is a risk that the fixing pin will come off and damage the diaphragm, etc. Furthermore, in the latter embodiment using welding, the plating must be removed from the electrode base, which is usually plated, for welding, and the unplated surface of the electrode base may be exposed to the high-concentration alkali in the electrolytic cell, which may result in dissolution of the surface of the electrode base and a deterioration in electrolytic characteristics.

[0008] The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide an electrolytic cell capable of suitably holding a conductive elastic body. [Means for solving the problem]

[0009] In order to achieve the above object, in one embodiment of the present invention, an anode, a cathode, a diaphragm disposed between the anode and the cathode, a conductive elastic body provided on a back surface side of one of the anode and the cathode, an electrode base provided on the back surface side of the conductive elastic body and having a plurality of openings, and an attachment member capable of attaching the conductive elastic body to the electrode base, The mounting member comprises a plate-shaped main body portion provided on the front side of the conductive elastic body, a first bent portion continuing from a predetermined position of the plate-shaped main body portion, and a second bent portion spaced apart and facing the first bent portion, and in a cross-sectional view, at least the plate-shaped main body portion and the conductive elastic body directly face each other, and the bent portion and the electrode base can directly face each other, thereby providing an electrolytic cell. [Effects of the Invention]

[0010] According to the electrolytic cell according to one embodiment of the present invention, the conductive elastic body, which is a component thereof, can be held in a suitable manner. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an exploded perspective view showing an electrolytic cell according to an embodiment of the present invention; [Figure 2] FIG. 10 is a partially enlarged plan view schematically illustrating a conductive elastic body attached to an electrode base according to an embodiment; [Figure 3A] FIG. 1 is a plan view schematically showing a cathode-side support, which is a component of an electrolytic cell according to an embodiment of the present invention. [Figure 3B] FIG. 3B is a cross-sectional view schematically showing the cathode-side support taken along line II-II′ in FIG. 3A. [Figure 3C] FIG. 3B is a cross-sectional view schematically showing the cathode-side support taken along line II′ in FIG. 3A. [Figure 4] FIG. 1 is an enlarged partial cross-sectional view schematically illustrating an electrolytic cell according to an embodiment of the present invention, which includes a conductive elastic body attached to an electrode base via an attachment member. [Figure 5A] FIG. 1 is a plan view schematically showing an installation preparation member in a pre-installation stage, which is a component of an electrolytic cell according to an embodiment of the present invention. [Figure 5B] 5B is a side view schematically showing the pre-attachment stage of the attachment preparation member taken along line III-III′ in FIG. 5A. [Figure 5C] FIG. 1 is a side view schematically showing an installation preparation member, which is a component of an electrolytic cell according to an embodiment of the present invention, in an intermediate stage of installation. [Figure 5D]FIG. 1 is a cross-sectional view schematically illustrating a mounting member, which is a component of an electrolytic cell according to an embodiment of the present invention, at a stage where mounting is completed. [Figure 6A] FIG. 1 is a plan view schematically illustrating an attachment preparation member in a pre-attachment stage according to an embodiment; [Figure 6B] FIG. 10 is a plan view schematically showing an attachment preparation member in a pre-attachment stage according to another embodiment; [Figure 6C] FIG. 10 is a plan view schematically showing an attachment preparation member in a pre-attachment stage according to another embodiment; [Figure 7] FIG. 10 is a partially enlarged plan view schematically illustrating a conductive elastic body attached to an electrode base according to another embodiment. [Figure 8A] FIG. 10 is a plan view schematically showing an installation preparation member in a pre-installation stage, which is a component of an electrolytic cell according to another embodiment of the present invention. [Figure 8B] FIG. 10 is a plan view schematically showing an installation preparation member in an intermediate installation stage (bending stage) that is a component of an electrolytic cell according to another embodiment of the present invention. [Figure 8C] FIG. 10 is a cross-sectional view schematically showing an installation preparation member, which is a component of an electrolytic cell according to another embodiment of the present invention, in an intermediate stage of installation (the stage of insertion into the opening of the electrode base); [Figure 8D] FIG. 10 is a cross-sectional view schematically showing a mounting member, which is a component of an electrolytic cell according to another embodiment of the present invention, in the mounting completion stage. DETAILED DESCRIPTION OF THE INVENTION

[0012] An electrolytic cell according to one embodiment of the present invention will be described in detail below with reference to the drawings. Various elements in the drawings are merely shown schematically and exemplarily to facilitate understanding of the present invention, and the overall appearance and dimensional ratios may differ from those of the actual parts.

[0013] In this specification, the term "electrolytic cell" refers, in a broad sense, to an apparatus for performing electrolysis, and in a narrow sense, to an apparatus including at least an anode, a cathode, and a diaphragm disposed between the electrodes. In this specification, the term "electrode for electrolysis" refers, in a broad sense, to an electrode used in an apparatus for performing electrolysis, and in a narrow sense, to an anode and / or cathode used in such an apparatus.

[0014] The term "plan view" as used herein refers to the shape of an object viewed from above or below along a thickness direction based on the extension direction of the diaphragm, electrodes, etc. that constitute the electrolytic cell. Furthermore, the term "cross-sectional view" as used herein refers to a state when viewed from a direction approximately perpendicular to the thickness direction of the support, electrodes, etc. that constitute the electrolytic cell. The terms "upper-lower direction" and "left-right direction" used directly or indirectly in this specification correspond to the upper-lower direction and left-right direction in the drawings, respectively. Unless otherwise specified, the same symbols or symbols indicate the same components or parts or have the same meaning. In a preferred embodiment, the vertical downward direction (i.e., the direction in which gravity acts) can be considered to correspond to the "downward direction," and the opposite direction to that corresponds to the "upward direction."

[0015] The various numerical ranges referred to in this specification are intended to include both the lower and upper limits. For example, a numerical range such as 1 to 10 is interpreted as including the lower limit of "1" and the upper limit of "10."

[0016] First, the basic configuration of the electrolytic cell that is the premise of the present invention will be described, and then the features of the present invention will be described. In the following description, electrodes for the electrolytic cell, i.e., electrodes for electrolysis, will also be referred to simply as "electrodes," or more specifically as "anodes" or "cathodes."

[0017] [Basic configuration of electrolytic cell] The basic configuration of an electrolytic cell according to one embodiment of the present invention will be described below with reference to Fig. 1. Fig. 1 is an exploded perspective view that schematically shows an electrolytic cell according to one embodiment of the present invention. As shown in Fig. 1, an electrolytic cell 1000 according to one embodiment of the present invention includes at least an anode 100, a cathode 200, and a diaphragm 300 disposed between the anode 100 and the cathode 200.

[0018] The anode 100 and the cathode 200 are electrodes for externally applying electrical energy to the electrolyte solution. Typically, the anode 100 is an electrode connected to the positive electrode of an external power source, and is an electrode where an oxidation reaction can occur during operation of the electrolytic cell. On the other hand, the cathode 200 is an electrode typically connected to the negative electrode of the external electrode, and is an electrode where a reduction reaction can occur during operation of the electrolytic cell.

[0019] The diaphragm 300 is typically a member that separates the anode chamber from the cathode chamber. Preferably, the diaphragm 300 is provided to prevent mixing of substances produced at the anode and substances produced at the cathode. In the present invention, the diaphragm 300 may be one that is conventionally used in electrolysis. For example, the diaphragm 300 is an ion exchange membrane. As just one example, in an electrolytic cell used in the soda industry, a cation exchange membrane may be used as the diaphragm 300.

[0020] The electrolytic cell 1000 according to one embodiment of the present invention may further include a conductive elastic body 400 provided on the back side of one of the anode 100 and the cathode 200, an electrode base 500 provided on the back side of the conductive elastic body 400, and an outer casing 600.

[0021] The electrode base 500 may be a metal plate having electrical conductivity and corrosion resistance. For example, a plate made of nickel, stainless steel, or the like may be used. Alternatively, a metal plate made of copper or the like with a nickel coating on its surface may be used. The electrode base 500 may also be a metal plate with openings to allow smooth flow of the electrolyte, generated gas, and the like within each electrode chamber in the electrolytic cell 1000.

[0022] The exterior body 600 constitutes the exterior of the electrolytic cell 1000 and is composed of a set of two supports (an anode-side support 610 and a cathode-side support 620). The anode-side support 610 has a support frame 610A located at the edge, a bottom (not shown) that is continuous with the support frame 610A and forms an internal space (specifically, a recessed space), and a support portion (corresponding to a rib) (not shown) for installing the electrode base 500 (see FIG. 1). Similarly, the cathode-side support 620 has a support frame 620A located at the edge, a bottom 620B that is continuous with the support frame 620A and forms an internal space (specifically, a recessed space), and a support portion 620C (corresponding to a rib) for installing the electrode base 500 (see FIGS. 1, 3B, and 3C). That is, in the supports 610 and 620, the support frames are configured to surround the internal space (specifically, the recessed space). Furthermore, it is preferable that a gasket be positioned on the upper surface (corresponding to the sealing surface) of each support frame 610A, 620A. Specifically, the gasket is arranged to seal the gap between the sealing surfaces of the support frames to prevent leakage of the electrolyte or generated gas from the electrode chambers to the outside. The gasket is elastic, and by utilizing elastic deformation due to compression, gaps are preferably prevented from occurring between the sealing surfaces of the support frames.

[0023] The gasket may be one commonly used in electrolysis. For example, the gasket is preferably made of an alkaline-resistant, elastic material with high sealing properties. For example, the gasket may be made of at least one resin material selected from the group consisting of natural rubber, isoprene rubber, styrene-butadiene rubber, butyl rubber, butadiene rubber, ethylene-propylene rubber (EPM rubber), ethylene-propylene-diene rubber (EPDM rubber), chloroprene rubber, silicone rubber, fluororubber, acrylic rubber, porous PTFE (polytetrafluoroethylene), etc.

[0024] FIG. 2 is a partially enlarged plan view schematically illustrating a conductive elastic body attached to an electrode base. As shown in FIG. 2, the conductive elastic body 400 contributes to the flow of current between the electrodes due to its conductivity, while exerting a pressing force on the electrodes due to its elasticity. In other words, the conductive elastic body 400 corresponds to a conductive component capable of providing a reaction force in the electrolytic cell, and includes a structure capable of elastic deformation to provide such a reaction force. The conductive elastic body 400 is used in the electrolytic cell 1000 in a state subjected to elastic deformation in order to exhibit spring characteristics. Specifically, the conductive elastic body 400 is provided in the electrolytic cell 1000 in a state subjected to deformation such that the wavy curvature of the elastic portion 430 is reduced.

[0025] Specifically, the reaction force of the conductive elastic body 400 is used to press an electrode assembly including an anode, a cathode, and an ion exchange membrane between those electrodes. The conductive elastic body 400 is used in a state in which it is subjected to elastic deformation on the back side of the electrode assembly, and the elastic force (i.e., reaction force) provided by the conductive elastic body 400 applies a pressing force to the electrode assembly. In particular, the conductive elastic body 400 subjected to elastic deformation acts to apply a pressing force from one electrode toward the other electrode, thereby promoting close contact of the electrode assembly. In other words, the presence of the conductive elastic body 400 results in close contact between the anode 100, the diaphragm 300, and the cathode 200, enabling the electrolytic cell to function favorably as a so-called zero-gap type.

[0026] The conductive elastic body 400 used in the electrolytic cell 1000 may have any form as long as it generates an elastic repulsive force. For example, the conductive elastic body 400 may have various forms such as an elastic cushion, an elastic mat (e.g., a member made of a metal coil, a metal nonwoven fabric, a knitted or woven fabric made of metal wire, etc.), a leaf spring, etc.

[0027] As an example, the conductive elastic body 400 may have a fixed portion 410 with a plurality of openings 420 formed at predetermined intervals, and a plurality of wavy elastic portions 430 extending from the fixed portion 410 (see FIG. 2). In a large electrolytic cell, a plurality of conductive elastic bodies 400 may be provided rather than being used singly (see FIG. 1). In this specification, the term "fixed portion" refers to a main skeletal portion that serves as the axis or base of a component. In this specification, the term "elastic portion" refers to a secondary skeletal portion that extends or branches from the axis or base portion.

[0028] In one example, the multiple elastic portions 430 have a shape in which wave-like curves are alternately arranged. The fixing portion 410 is preferably an elongated member. Furthermore, the fixing portion 410 preferably extends in a plane. The elastic portion 430 extends in a non-planar manner and has a curved shape.

[0029] The multiple elastic portions 430 are provided so as to extend from multiple locations along the longitudinal direction of the fixed portion 410, particularly from the side portions of the fixed portion 410. The multiple elastic portions 430 may extend from only one side of the fixed portion 410, or may extend from both sides of the fixed portion 410. In the conductive elastic body 400, the fixed portion 410 and the elastic portions 430 are preferably integrated with each other. In such an integrated body, the fixed portion 410 has a non-curved shape, while the elastic portions 430 have a curved shape. For example, the curved elastic portions 430 extend in a direction perpendicular to the longitudinal direction of the non-curved fixed portion 410.

[0030] According to this configuration, the conductive elastic body 400 has a leaf spring shape with the fixed portion 410 and the multiple elastic portions 430 as a skeletal structure. Therefore, stress acts on the conductive elastic body 400 to restore its original shape, providing a reaction force as a spring characteristic and reducing the likelihood of breakage during use of the electrolytic cell. Furthermore, each of the multiple elastic portions 430 of the conductive elastic body 400 is curved in a wave-like manner, and this wave-like arrangement can be non-aligned along the longitudinal direction of the fixed portion 410. This allows the contact points between the conductive elastic body 400 and the electrodes to be optimal for current distribution during electrolysis. In particular, the contact points between the conductive elastic body 400 and the electrodes are likely to form a so-called houndstooth-shaped contact. This reduces the likelihood of biased current flow and leads to a uniform current distribution overall. As a result, the electrolysis voltage during electrolysis is reduced overall, potentially improving the efficiency of the electrolytic cell 1000. Furthermore, the voltage drop due to structural resistance of the cathode 200 can also be reduced.

[0031] The conductive elastic body 400 is made of metal from the viewpoints of both its elastically deformable structure and electrical conductivity. For example, the conductive elastic body 400 may be made of a substrate of at least one material selected from the group consisting of titanium, nickel, stainless steel, iron, copper, and alloys thereof. The material of the conductive elastic body 400 is not limited to metal, but may also be carbon. Therefore, the conductive elastic body 400 may be made of carbon in addition to or instead of metal. An electrolytic reaction catalyst may also be added to such a substrate. For example, if the electrolytic cell 1000 is a sodium chloride electrolytic cell, the substrate may be coated with a platinum group metal, and the conductive elastic body 400 may have a hydrogen generation catalytic function.

[0032] Furthermore, in the electrolytic cell 1000, the electrodes (at least one of the anode 100 and the cathode 200) may be a conductive porous substrate having liquid permeability. In other words, it is preferable that at least one of the anode 100 and the cathode 200 is an electrode having mesh openings. By way of example only, the electrodes may be made of expanded metal, wire mesh (plain weave mesh, twill weave mesh), punched metal, or the like.

[0033] From the viewpoint of corrosion resistance, each of the anode 100 and the cathode 200 may comprise at least one selected from the group consisting of titanium, nickel, stainless steel, tantalum, zirconium, niobium, etc. Furthermore, an appropriate catalyst may be supported on each of the anode 100 and the cathode 200. The aperture ratio of the conductive porous substrate is not particularly limited, but may be about 20% to 90%, for example, 30% to 80%, 40% to 75%, or 50% to 75%, etc.

[0034] The electrolytic cell is preferably a zero-gap type, and has characteristics suitable for such a zero-gap type. One such characteristic is that the anode 100 and the cathode 200 are characterized in terms of the rigidity and flexibility of the electrode materials, i.e., hardness and softness. Specifically, it is preferable that one of the anode 100 and the cathode 200 is relatively flexible relative to the other, and conversely, the other is relatively rigid relative to the other. This allows the relatively flexible electrode to bend due to the reaction force of the conductive elastic body, while the relatively rigid electrode can absorb that bending via the diaphragm 300.

[0035] From this viewpoint, the anode, the ion exchange membrane, and the cathode are more closely attached to each other, and the electrolytic cell can function more effectively as a "zero-gap type." This is particularly true when the electrolytic cell is large. That is, this is particularly true when the main electrode surfaces that require pressure for zero-gap electrolysis are large, as typified by zero-gap type sodium chloride electrolysis.

[0036] To obtain a larger amount of the desired electrolysis product, a larger electrolytic cell is used, and the main surfaces of the electrodes (particularly the main surfaces where the anode 100 and the cathode 200 face each other) also become larger accordingly. A large zero-gap electrolytic cell is preferably composed of multiple electrolytic cell units, and each of these electrolytic cell units has large electrode main surfaces on both opposing side surfaces. Taking a so-called "bipolar" electrolytic cell as an example, a cathode 200 (e.g., a cathode surface made of expanded metal) is provided on one of the opposing side surfaces of the electrolytic cell unit, and an anode 100 (e.g., an anode surface made of expanded metal) is provided on the other of the opposing side surfaces. In the electrolytic cell, multiple such electrolytic cell units are connected to each other so as to be stacked one on top of the other with diaphragms 300 (e.g., cation exchange membranes) interposed therebetween.

[0037] In particular, adjacent electrolytic cell units are stacked such that the cathode surface of one electrolytic cell unit faces the anode surface of the other electrolytic cell unit. In this way, an electrolytic cell is constructed by combining multiple electrolytic cell units via ion exchange membranes. Note that an electrolytic cell constructed from multiple electrolytic cell units is not limited to a "bipolar" type, but may also be a "monopolar" type. In other words, the electrode cell units constituting the electrolytic cell are not limited to bipolar electrolytic cell units having an anode portion and a cathode portion on opposing side surfaces, but may also be "monopolar" electrolytic cell units having only an anode portion and only a cathode portion on opposing side surfaces. In such cases, an electrolytic cell can be constructed by combining electrolytic cell units having only an anode portion and electrolytic cell units having only a cathode portion so that they are alternately arranged via ion exchange membranes.

[0038] Electrolytic cells composed of electrolytic cell units have relatively large electrode principal surfaces. While this is desirable because the desired electrolytic reaction occurs through these large electrode surfaces, maintaining the flatness of the electrode surfaces becomes difficult. Specifically, the larger the electrode principal surfaces, the more likely it is that the effects of bending due to their own weight become significant. Furthermore, factors such as attachment to the electrode support also have an impact, making it difficult to achieve perfectly flat electrode principal surfaces. For example, in the electrolytic cell 1000 illustrated in FIG. 1, the main surface sizes of the anode and cathode surfaces are on the order of several meters. Even if the electrodes are made rigid enough to achieve a suitable flat surface, for the reasons described above, such large electrode principal surfaces have a flatness of, for example, ±0.5 mm to ±1.0 mm, making it difficult to achieve a perfectly flat surface (i.e., a flatness of 0 mm). In other words, in large electrolytic cells, rigid electrode principal surfaces may appear flat macroscopically, but tend to have localized irregularities when viewed microscopically.

[0039] If electrodes that do not have completely flat surfaces are brought into close contact with each other via an ion exchange membrane, the unevenness may cause a loss of uniformity in current distribution. Therefore, in a preferred electrolytic cell, the electrode that pairs with a rigid electrode is a soft, flexible electrode. This allows the flexible electrode to bend to follow the unevenness of the rigid electrode surface, even if the electrodes are tightly brought into close contact with each other via an ion exchange membrane, thereby effectively preventing non-uniformity in current distribution.

[0040] As just one example, the anode may be made of a relatively hard, rigid expanded metal, while the cathode may be made of a relatively soft, flexible expanded metal. A conductive elastic body 400 may be provided on the back side of the flexible expanded metal of the cathode, which is combined with the rigid expanded metal of the anode via an ion exchange membrane. In this case, the flexible expanded metal of the cathode is pressed toward the rigid expanded metal of the anode by the reaction force of the conductive elastic body 400, and at this time, the flexible expanded metal of the cathode can be locally displaced depending on the flatness of the main surface of the rigid expanded metal of the anode. Therefore, even when the electrolytic cell units are tightly fastened together and the reaction force of the conductive elastic body 400 is large, the anode 100, diaphragm 300, and cathode 200 are in favorable contact with each other, and undesirable phenomena such as non-uniform current distribution are unlikely to occur.

[0041] Although not particularly limited, a relatively rigid expanded metal may have a thickness of about 0.2 to 2.0 mm due to its characteristics, and the width (interval) of the strands forming the pores, i.e., openings, may be about 0.2 to 2.0 mm. A flexible expanded metal may have a thickness of about 0.1 to 1.0 mm, preferably about 0.1 to 0.5 mm, and the width of the strands forming the pores, i.e., openings, may be about 0.1 to 2.0 mm, preferably about 0.1 to 1.5 mm. When a wire mesh or punched metal is used as the flexible electrode, the thickness may be, for example, about 0.1 to 1.0 mm, preferably about 0.1 to 0.5 mm. In the case of a wire mesh, the wire diameter φ, which refers to the approximate diameter of the metal fibers constituting the wire mesh, may be about 0.05 to 1.0 mm, preferably about 0.1 to 0.5 mm. In the case of a punched metal, the non-opening length L between adjacent openings may be about 0.1 to 2.0 mm, preferably about 0.1 to 1.5 mm.

[0042] As one example, in an arrangement in which an expanded metal flexible cathode 200, a diaphragm 300, and an expanded metal rigid anode 100 are stacked in that order, a conductive elastic body 400 is provided on the back side of the cathode 200 (i.e., the side opposite to the side on which the diaphragm 300 is installed). The conductive elastic body 400 is provided while being subjected to deformation so as to be constricted between the expanded metal cathode 200 and the cathode base 500. Therefore, the elastic force of the conductive elastic body 400 is directly applied to the expanded metal flexible cathode 200 that is in direct contact with the elastic portion 430 of the conductive elastic body 400. As a result, the expanded metal flexible cathode 200 is biased so as to be pressed toward the expanded metal rigid anode 100, bringing the flexible cathode 200, the diaphragm 300, and the rigid anode 100 into close contact with one another. The rigid anode itself is fixed so as not to move to the electrode support of the electrolytic cell unit, and therefore acts to receive the elastic force of the conductive elastic body, contributing to close contact.

[0043] [Characteristics of the present invention] The following describes the characteristics of electrolytic cell 1000 according to one embodiment of the present invention. The inventors of the present invention have conducted extensive research into the configuration of an electrolytic cell that can favorably hold conductive elastic body 400, which is a component of electrolytic cell 1000. As a result, the inventors have devised an electrolytic cell according to one embodiment of the present invention that has the following characteristics.

[0044] The electrolytic cell 1000 according to one embodiment of the present invention further includes a mounting member 700 capable of mounting the conductive elastic body 400 to the electrode base 500 (see FIGS. 1 to 4). In one embodiment of the present invention, the configuration of the mounting member 700 is a technical feature.

[0045] The mounting member 700 comprises a plate-shaped main body portion 710 provided on the front side of the conductive elastic body 400, and at least two bent portions 720 continuing from predetermined positions on the plate-shaped main body portion 710. The bent portions 720 may be crimped portions. Specifically, the at least two bent portions 720 comprise a first bent portion 721 and a second bent portion 722 spaced apart and facing the first bent portion 721.

[0046] In one embodiment, the curved portion 720 can be continuous from within the main region 713 of the plate-shaped main body portion 710 (see FIGS. 2 and 4). In this case, the main body portion 710 of the mounting member 700 can be arranged to extend along the longitudinal direction of the fixing portion 410 of the conductive elastic body 400. In another embodiment, the curved portion 720α can be continuous from the side region 712α of the plate-shaped main body portion 710α (see FIGS. 7 and 8D). In this case, the main body portion 710α of the mounting member 700α can be arranged to extend along the lateral direction of the fixing portion 410α of the conductive elastic body 400α.

[0047] The following description will be given taking the above-described embodiment as an example. Each of the first bent portion 721 and the second bent portion 722 has, in a cross-sectional view, a first region 720A facing the plate-shaped main body portion 710 and a second region 720B (corresponding to a predetermined region) extending in a direction intersecting the extending direction of the plate-shaped main body portion 710. In this specification, "the first region 720A facing the plate-shaped main body portion 710" refers to a positional relationship in which the main surface of the first region 720A can face the main surface of the plate-shaped main body portion 710.

[0048] Furthermore, in a cross-sectional view, at least the plate-shaped main body portion 710 and the conductive elastic body 400 directly face each other, and the bent portion 720 and the electrode base 500 can directly face each other. Specifically, the rear main surface 711 of the plate-shaped main body portion 710 directly faces the conductive elastic body 400, and the bent portion 720 can directly face the rear main surface 510 and the side surface 520 of the electrode base 500 (see FIG. 4 ). Note that, in this specification, the "rear main surface 710 of the plate-shaped main body portion 710" refers to the main surface of the main body portion 710 provided on the distal side relative to the flexible electrode (e.g., a flexible cathode). Also, in this specification, the "rear main surface 510 of the electrode base 500" refers to the main surface of the electrode base 500 provided on the distal side relative to the conductive elastic body 400, specifically, the continuous main surface formed between adjacent openings on the rear side of the electrode base 500. According to this configuration, in a cross-sectional view, the main body portion 710 of the mounting member 700 abuts against the conductive elastic body 400, and each bent portion 720 can abut against the electrode base 500. Specifically, in a cross-sectional view, at least the first bent portion 721 and the second bent portion 722 can abut against the electrode base 500.

[0049] From another perspective, in a cross-sectional view, at least a part of the electrode base 500 is positioned within a region surrounded by the main body portion 710 of the mounting member 700, the first bent portion 721 that is continuous with the main body portion 710, and the second bent portion 722. With this configuration, in a cross-sectional view, the main body portion 710 of the mounting member 700 can directly face the electrode base 500, and the bent portion 720 can abut against the electrode base 500.

[0050] On the other hand, when the bent portion 720α is continuous from the side region 712α of the plate-shaped main body portion 710α based on the above-mentioned other embodiment, an overlapping portion 800 in which a portion of the conductive elastic body 400α and a portion of the electrode base 500 overlap each other can be positioned within the area surrounded by the main body portion 710α of the mounting member 700α and at least two mutually opposing bent portions 720α (a first bent portion 721α and a second bent portion 722α) that are continuous with the main body portion 710α (Figures 7 and 8D).

[0051] From another perspective, the second region 720B of the bent portion 720 can be inserted at least into the first opening portion 530 of the electrode base 500 that face each other and the second opening portion 540 that faces and separates from the first opening portion 530. This allows the electrode base 500 to be sandwiched between the second regions 720B of the two bent portions 720 that face each other in a cross-sectional view.

[0052] In one example, a first overlapping opening portion X is formed between the conductive elastic body 400 and the electrode base 500 by the overlapping opening portion 420 of the conductive elastic body 400 and the first overlapping opening portion 530 of the electrode base 500. Furthermore, a second overlapping opening portion Y is formed by the overlapping opening portion 420 of the conductive elastic body 400 and the second overlapping opening portion 540 of the electrode base 500, spaced apart and facing the first overlapping opening portion X. In this state, in one embodiment of the present invention, the second region 720B of each bent portion 720 can be inserted into the first overlapping opening portion X and the second overlapping opening portion Y, respectively, in a cross-sectional view.

[0053] In this specification, the term "overlapping opening portion" refers to an opening portion formed between the conductive elastic body 400 and the electrode base 500, where the opening portions 530, 540 of the electrode base 500 and the opening portion 420 of the conductive elastic body 400 overlap each other.

[0054] For the above reasons, even if forces are applied in the extension direction (corresponding to the longitudinal direction) and thickness direction (corresponding to the lateral direction) of the conductive elastic body 400, the main body portion 710 and the bent portion 720 of the mounting member 700 can suppress displacement of the conductive elastic body 400. As a result, according to one embodiment of the present invention, the conductive elastic body 400 can be suitably held in a predetermined position. For the above reasons, one embodiment of the present invention is advantageous in that it can suitably hold the conductive elastic body 400 in a predetermined position without using the conventional "aspects using a fixing pin" and "aspects using welding."

[0055] Furthermore, compared to the conventional "aspect of using a fixing pin," in one embodiment of the present invention, there are two or more bent portions, which makes it possible to increase the number of contact points between the attachment member 700 and the electrode base 500. This can make it less likely that bias will occur in the current flow during electrolysis operation, which can reduce the overall electrolysis voltage.

[0056] In a preferred embodiment, two or more bent portion groups each including a first bent portion and a second bent portion are provided at a predetermined interval. This embodiment increases the number of portions where the bent portions directly face the electrode base in cross-sectional view. This increases the number of contact points between the bent portions and the electrode base in cross-sectional view. This allows the conductive elastic body to be more appropriately held in a predetermined location.

[0057] In one embodiment, adjacent bent portion groups 750 and the other bent portion group 750 can be arranged in series along the extension direction of the fixing portion 410 of the conductive elastic body 400 (see FIGS. 2 and 4). In this case, provided that the main body portion 710 of the mounting member 700 can directly face the electrode base 500, it is possible to increase the number of portions where the bent portions 720 directly face the electrode base 500. This makes it possible to increase the number of contact points between the bent portions 720 and the electrode base 500 in a cross-sectional view. This makes it possible to more suitably hold the conductive elastic body 400 in a predetermined position.

[0058] On the other hand, in another embodiment, when the bent portion 720α continues from the side region 712α of the plate-shaped main body portion 710α, adjacent bent portion groups 750α and 750α may be arranged in series along a direction substantially perpendicular to the extension direction of the fixing portion 410α of the conductive elastic body 400α (see FIGS. 7 and 8D). In such a configuration, two or more sets of "overlapping portions 800 between a portion of the conductive elastic body 400α and a portion of the electrode base 500" may be provided within the region surrounded by the main body portion 710α of the mounting member 700α and two opposing bent portions 720α. This increases the number of portions where the plate-shaped main body portion 710α and the conductive elastic body 400α directly face each other in a cross-sectional view. Therefore, it is possible to increase the number of contact points between the plate-shaped main body portion 710α and the conductive elastic body 400α, in addition to the number of contact points between the bent portion 720α and the electrode base 500. For these reasons, this embodiment also makes it possible to more suitably hold the conductive elastic body 400α in a predetermined position.

[0059] (Method of manufacturing electrolytic cell 1000 according to one embodiment of the present invention) A method for manufacturing an electrolytic cell 1000 according to one embodiment of the present invention will be described below. In particular, the method for manufacturing an electrolytic cell 1000 according to one embodiment of the present invention includes a "step of forming a mounting member 700" having the above-described configuration.

[0060] Figure 5A is a plan view schematically showing an installation preparation member 700I in a pre-installation stage, which is a component of an electrolytic cell according to one embodiment of the present invention, and Figure 5B is a side view schematically showing the installation preparation member in a pre-installation stage taken along line III-III' in Figure 5A.

[0061] The following description will be given taking, as an example, the case of forming a curved portion 720 (see FIGS. 2 and 4) continuing from the main region 713 of a plate-shaped main body portion 710 according to one embodiment. As shown in FIGS. 5A and 5B , first, an attachment-prepared member 700I is prepared in a pre-attachment stage. The attachment-prepared member 700I is a plate-shaped member having a first slit portion 730I and a second slit portion 740I that are spaced apart and opposed to each other before attachment. That is, the attachment-prepared member 700I before use comprises a plate-shaped main body portion 710I and at least two slit portions 730I, 740I that are opposed to each other.

[0062] Due to the slit shapes of the first slit portion 730I and the second slit portion 740I, the inner region 711I surrounded by each slit portion can be flexible. Therefore, by pushing the flexible portion surrounded by each slit portion downward, it is possible to move from the initial state shown in Figures 5A and 5B to the intermediate state shown in Figure 5C.

[0063] Each slit portion may be curved outward or inward in a plan view. Alternatively, each slit portion may be arranged in a line along the longitudinal direction of the plate-shaped main body portion 710I. While not particularly limited thereto, in one example, the slit portion may be curved outward in a U-shape in a plan view, as shown in FIGS. 5A and 6A. In another example, the slit portion may have one bending point in a plan view and be curved outward, as shown in FIG. 6B. In yet another example, the slit portion may have two bending points in a plan view and be curved outward, as shown in FIG. 6C.

[0064] FIG. 5C is a side view schematically illustrating an attachment member in an intermediate attachment stage, which is a component of an electrolytic cell according to one embodiment of the present invention. In the intermediate state shown in FIG. 5C, two extension portions 720I (first extension portion 721I and second extension portion 722I) can be formed, extending in a direction substantially perpendicular to the extension direction of plate-shaped main body portion 710I. This allows for the provision of attachment preparation member 700I, which includes plate-shaped main body portion 710I and two extension portions 720I (first extension portion 721I and second extension portion 722I). Note that first extension portion 721I and second extension portion 722I are positioned facing each other at a distance from each other.

[0065] Then, the electrode base 500 is installed by welding the edges to the support frame side by welding or the like on the support portion (corresponding to the rib) of the support on the side where the conductive elastic body 400 is installed. As the support on the side where the conductive elastic body 400 is installed, for example, the cathode side support shown in Figures 1 and 3A to 3C can be used. In this case, the electrode base 500 can serve as the cathode base. After installing the electrode base 500, the conductive elastic body 400 is installed so as to face the main surface of the electrode base 500, and both ends of the conductive elastic body 400 installed on a metal plate (e.g., a Ni plate) welded to the support frame are spot-welded.

[0066] 2, for example, an attachment preparation member 700I is provided so that a main body portion 710I (see also FIG. 5C) is positioned on the fixing portion 410 of the conductive elastic body 400. In one embodiment, when an attachment preparation member having a slit portion as shown in FIG. 5A is used, the attachment preparation member 700I is placed so that the main body portion 710I extends along the longitudinal direction of the fixing portion 410 of the conductive elastic body 400.

[0067] Specifically, the first extension portion 721I and the second extension portion 722I of the attachment preparation member 700I shown in Fig. 5C are inserted into the mutually opposing first opening portion 530 and second opening portion 540 of the electrode base 500. More specifically, when an attachment preparation member having the slit portion shown in Fig. 5A is used, the first extension portion 721I and the second extension portion 722I of the attachment preparation member 700I shown in Fig. 5C are inserted into the first overlapping opening portion X and the second overlapping opening portion Y formed between the conductive elastic body 400 and the electrode base 500 described above in cross-sectional view.

[0068] After the extension portion 720I of the attachment preparation member 700I has been inserted, the jig 2000 is inserted through the openings 530, 540 of the electrode base 500 via the opening 760I formed in the attachment preparation member 700I shown in the lower right of Fig. 2 and in Fig. 5C. After the jig 2000 is inserted, the jig 2000 is used to crimp portions of the two extension portions 720I so that a portion of the first extension portion 721I and a portion of the second extension portion 722I (see Figs. 2 and 5D) of the attachment preparation member 700I are each bent inward.

[0069] On the other hand, according to another embodiment, when forming the bent portion 720α continuing from the side region 712α of the plate-shaped main body portion 710α, a pre-attachment stage attachment preparation member 700αI can be used, which has mutually opposing protrusions 720αI on the side region 712αI of the plate-shaped main body portion 710αI (see FIGS. 7 and 8A). Specifically, the mutually opposing protrusions 720αI can be provided so as to be positionable on both sides of the fixing portion 410α of the conductive elastic body 400α, with the fixing portion 410α serving as the long axis. Such two protrusions 720αI can be arranged at any position on the side region 712αI of the plate-shaped main body portion 710αI, as long as they are located on both sides of the long axis of the fixing portion 410α.

[0070] In one example, the first protrusion 721αI and the second protrusion 722αI may be provided on the short side 714αI of the side region 712α of the main body portion 710αI. In another example, the first protrusion 721αI and the second protrusion 722αI may be provided on both end sides of the side region 712αI. The drawings (FIGS. 8A to 8D) show an example in which the first protrusion 721αI and the second protrusion 722αI are provided on both ends of the side region 712αI. In this case, as will be described later, it is preferable that two or more protrusion groups 750αI each including a first protrusion 721αI and a second protrusion 722αI are provided at a predetermined interval (see FIGS. 7 and 8A).

[0071] Thereafter, the protrusion 720αI is bent in a direction substantially perpendicular to the extending direction of the plate-shaped main body portion 710αI (see FIG. 8B). Next, similar to the case of forming the bent portion 720 (see FIGS. 2 and 4) continuing from the main region 713 of the plate-shaped main body portion 710 described above, after the electrode base 500 is installed, the conductive elastic body 400α is installed so as to face the main surface of the electrode base 500, and then the attachment preparation member 700αI is provided so that the main body portion 710αI is positioned on the fixing portion 410α of the conductive elastic body 400α. In such another embodiment, the attachment preparation member 700αI is installed so that the main body portion 710αI straddles the short side direction of the fixing portion 410α of the conductive elastic body 400α (see FIG. 7).

[0072] In this state, the mutually opposing protrusions 720αI provided on the side portion 712αI of the plate-shaped main body portion 710αI are inserted into the mutually opposing first opening portion 550 and second opening portion 560 of the electrode base 500 (see FIG. 8C). After the protrusions 720αI are inserted, a jig is inserted so that it passes through the first opening portion 550 and the second opening portion 560 of the electrode base 500, and then the jig is used to crimp at least two mutually opposing protrusions 720αI of the attachment preparation member 700αI so that the protrusions 720αI are bent inward (see FIG. 8D).

[0073] As a result of the above, in any embodiment, mounting members 700, 700α can be formed, each comprising a plate-shaped main body portion 710, 710α provided on the front side of conductive elastic body 400, 400α, and at least two bent portions 720, 720α continuing from predetermined locations on plate-shaped main body portion 710, 710α (see Figures 2, 5D, 7 and 8D).

[0074] As a result, as shown in Figures 5D and 8D (cross-sectional views schematically showing the mounting member at the completion of mounting), in a cross-sectional view, the main body portions 710, 710α of the mounting member 700, 700α can be abutted against the conductive elastic bodies 400, 400α, and the electrode base 500 can be abutted against the bent portions 720, 720α. As a result, even if forces act in the extension direction (corresponding to the longitudinal direction) and thickness direction (corresponding to the lateral direction) of the conductive elastic bodies 400, 400α, the main body portions 710, 710α and the bent portions 720, 720α of the mounting member 700, 700α can suppress displacement of the conductive elastic bodies 400, 400α. As a result, the conductive elastic bodies 400, 400α can be suitably held in place.

[0075] In one embodiment, in a preferred aspect, two or more slit portion groups 750I each having a first slit portion 730I and a second slit portion 740I are provided at a predetermined interval (see FIG. 5A). In another embodiment, in a preferred aspect, two or more protrusion groups 750αI each having a first protrusion 721αI and a second protrusion 722αI are provided at a predetermined interval (see FIGS. 7 and 8A). According to this aspect, when the attachment members 700, 700α each having plate-shaped main body portions 710I, 710αI and bending portions 720, 720α are finally formed from the attachment preparation members 700I, 700αI, it is possible to increase the number of portions where the bending portions 720, 720α directly face the electrode base 500 in a cross-sectional view. This allows an increase in the number of contact points between the bent portions 720, 720α and the electrode base 500 in a cross-sectional view. This allows the conductive elastic bodies 400, 400α to be held in predetermined positions more suitably. Therefore, the conductive elastic bodies 400, 400α can be more suitably attached to the electrode base 500. After attaching the conductive elastic body 400, the cathode 200 made of a flexible porous substrate is placed opposite the conductive elastic body 400. In this case, the anode side is provided with an anode 100 made of a rigid porous substrate without placing a conductive elastic body.

[0076] Thereafter, with the diaphragm 300 positioned between the anode 100 and the cathode 200, the anode side support frame 610A and the cathode side support frame 620A are directly opposed to each other and then connected together. After the support frames are connected together in this manner, the electrolyte is poured into the electrode chambers. In this manner, an electrolytic cell 1000 according to one embodiment of the present invention can be manufactured.

[0077] Although one embodiment of the present invention has been described above, it is merely a typical example. Therefore, it will be readily understood by those skilled in the art that the present invention is not limited to this embodiment and that various other embodiments are possible. [Industrial Applicability]

[0078] An electrolytic cell according to an embodiment of the present invention can be used for electrolysis, for example in the soda industry. [Explanation of symbols]

[0079] 2000 Jig 1000 electrolytic cell 100 anode 200 cathode 300 Diaphragm 400, 400α conductive elastic body 410, 410α fixed part 420, 420α opening part 430 Elastic part 500 Electrode base 510 Back side principal surface of electrode base 520 Side of electrode base 530, 550, 570 First opening of electrode base 540, 560, 580 Second opening of electrode base 600 exterior body 610 Anode side support 620 Cathode side support 610A Anode side support frame 620A Cathode side support frame 620B Bottom of cathode support 620C Cathode side support support part (corresponding to rib) 700, 700α mounting parts 700I, 700αI installation preparation parts 710I, 710αI Plate-shaped main body of the installation preparation member 712αI Side region of plate-shaped body 720I extension part 721I 1st extension 722I Second extension 720αI Protrusion of installation preparation part 721αI First protrusion 722αI Second protrusion 710, 710α Plate-shaped main body 711 Back side main surface of plate-shaped main body 712 Side region of plate-like body part 713 Main area of ​​the plate-shaped body 720 Bent part 720A First region of bend 720B Second region of bend 721 First bend 722 Second bend 730I, 740I, 730II, 740II, 730III, 740III slit part 750, 750α bending subgroup 750I Slit subgroup 750αI Protrusions of installation preparation parts 800 Overlapping portion (the portion where a part of the conductive elastic body and a part of the electrode base overlap each other)

Claims

1. an anode, a cathode, a diaphragm disposed between the anode and the cathode, a conductive elastic body provided on a back surface side of one of the anode and the cathode, an electrode base provided on the back surface side of the conductive elastic body and having a plurality of openings, and an attachment member capable of attaching the conductive elastic body to the electrode base, the mounting member comprises a plate-shaped main body portion provided on the front side of the conductive elastic body, a first bent portion continuing from a predetermined position of the plate-shaped main body portion, and a second bent portion spaced apart and facing the first bent portion, and in a cross-sectional view, at least the plate-shaped main body portion and the conductive elastic body directly face each other, and the bent portion and the electrode base can directly face each other; An electrolytic cell in which, in a cross-sectional view, at least the electrode base is positioned within an area surrounded by the main body portion of the mounting member, the first bent portion continuous with the main body portion, and the second bent portion.

2. 2. The electrolytic cell according to claim 1, wherein, in a cross-sectional view, the main body portion of the mounting member abuts against the conductive elastic body, and each bent portion is capable of abutting against the electrode base portion.

3. 3. The electrolytic cell according to claim 1, wherein, in a cross-sectional view, a predetermined region of the first bent portion extending in a direction intersecting the extension direction of the main body portion and the predetermined region of the second bent portion are inserted into at least a first opening portion of the electrode base that faces each other and a second opening portion that faces the first opening portion at a distance, respectively.

4. 4. The electrolytic cell according to claim 3, wherein the conductive elastic body has a plurality of openings, and the predetermined region of each bent portion is inserted into an overlapping opening formed by the openings of the conductive elastic body and the openings of the electrode base, which overlap each other, in a cross-sectional view.

5. 5. The electrolytic cell according to claim 1, wherein two or more groups of bent portions each including the first bent portion and the second bent portion are provided at a predetermined interval.

6. 6. The electrolytic cell according to claim 1, wherein the bent portion is a crimped portion.

7. 7. The electrolytic cell according to claim 1, wherein the bent portion is continuous with the main region of the body portion.

8. 8. The electrolytic cell according to claim 1, wherein the bent portion is continuous with a side region of the main body portion.

9. 9. The electrolytic cell according to claim 1, wherein the conductive elastic body comprises a fixed portion and an elastic portion extending from the fixed portion, and the plate-shaped main body portion is disposed on the fixed portion.

10. 10. An electrolytic cell according to claim 9, dependent on claim 4, wherein the plurality of openings of the conductive elastic body are formed in the fixing portion.

11. The electrolytic cell according to any one of claims 1 to 10, which is a zero-gap electrolytic cell.

Images