CN113279003A

CN113279003A - Electrode structure for electrolytic cell

Info

Publication number: CN113279003A
Application number: CN202110181712.8A
Authority: CN
Inventors: 浅海清人; 寺田宏一; 松井尚平; 肥后桥弘喜
Original assignee: Osaka Soda Co Ltd
Current assignee: Osaka Soda Co Ltd
Priority date: 2020-02-18
Filing date: 2021-02-09
Publication date: 2021-08-20

Abstract

The invention provides an electrolytic cell technology capable of inhibiting damage of a diaphragm. As an electrode structure for an electrolytic cell, (I) at least one of an anode and a cathode is bent such that an end portion thereof is meandering in a cross-sectional view; (II) at least one of the anode and the cathode has an end-approaching member disposed in proximity to the end thereof; or (III) at least one of the anode and the cathode is attached to the electrode base via an intervening member interposed between the electrode and the electrode base on which the electrode is provided.

Description

Electrode structure for electrolytic cell

Technical Field

The present invention relates to an electrode structure for an electrolytic cell. In particular to an electrode structure of an electrolytic cell at least consisting of an anode, a cathode and a diaphragm between them.

Background

Electrolysis is currently commonly utilized in various industries. The electrolysis is carried out using an electrolytic cell. The electrolytic cell is of various types according to its use, but is provided with at least an anode and a cathode. For example, a cell that performs electrolysis of aqueous sodium chloride solution can produce chlorine, hydrogen, and sodium hydroxide (so-called caustic soda) for use in the production of basic feedstock for the chemical industry. And also for the electrolysis of aqueous alkaline solutions for the production of hydrogen.

Documents of the prior art

Patent document

Patent document 1: international publication (WO) No. 2012/091051

Patent document 2: japanese patent No. 5108043

Patent document 3: japanese patent No. 5970250

Disclosure of Invention

Technical problem to be solved

In general, in an electrolytic cell, in order to avoid mixing of a substance generated from an anode and a substance generated from a cathode, a separator is further provided. The process of electrolyzing an aqueous sodium chloride solution using an ion exchange membrane as a separator is also referred to as "salt electrolysis by an ion exchange membrane method" or the like. And also for the electrolysis of aqueous alkaline solutions for the production of hydrogen.

There are various types of electrolytic cells for common salt electrolysis by an ion exchange membrane method, but the zero-pole method is the mainstream. In a zero-pitch electrolytic cell, an anode, a separator and a cathode are closely attached to each other, thereby shortening the distance between the electrodes, reducing the resistance of an electrolyte and reducing power consumption. In the case of the "zero pitch" electrolytic cell, it is conceivable that one of the anode and the cathode is made softer and more flexible than the other, and the other is made to have relatively higher rigidity. More specifically, it is conceivable that one of the electrodes has a soft flexible structure capable of absorbing the tolerance of the electrode support frame and the like and the unevenness due to deformation, and the other electrode has a rigid structure having high rigidity and less deformation even when pressed against the diaphragm. In this case, by providing the conductive elastic body on the back side of the flexible electrode, it is possible to provide a pressure necessary to bring the cathode, the separator, and the anode into close contact with each other by the elastic force (i.e., the reaction force) of the conductive elastic body.

The present inventors have noticed that the problems still remain to be solved in the conventional electrolytic cells, and have considered that a solution is required. Specifically, the following technical problems are solved.

In the electrolytic cell, when the separator is damaged, electrolysis cannot be efficiently performed. Damage to the separator not only reduces the efficiency of the electrolysis operation but also risks direct contact of the electrolyte between the anode side and the cathode side, with the possibility of undesired accidental reactions.

For example, in the above-described "zero-pitch" electrolytic cell, the electrode and the ion exchange membrane are in direct contact, and therefore the ion exchange membrane is easily affected by the electrode. In particular, the edge of the end portion of the electrode (more specifically, the edge constituting the outermost edge of the electrode) generally used in such an electrolytic cell has a relatively sharp form, and the ion exchange membrane is easily damaged.

The present invention has been made in view of the above problems. That is, a main object of the present invention is to provide an electrolytic cell technology capable of suppressing damage to a separator.

(II) technical scheme

The inventor does not follow the prior art, but solves the technical problems through a brand new thought. The electrode structure achieving the above-described main object is thus invented.

In the present invention, an electrode structure having at least any one of the following (I) to (III) is provided as an electrode structure for an electrolytic cell.

(I) At least one of the anode and the cathode is bent in a meandering manner at an end thereof in a cross-sectional view;

(II) at least one of the anode and the cathode has an end-approaching member disposed in proximity to the end thereof; and

(III) at least one of the anode and the cathode is attached to the electrode base portion via an intervening member interposed between the electrode and the electrode base portion on which the electrode is provided.

(III) advantageous effects

The electrode structure of the present invention can suppress damage to the separator in the electrolytic cell.

Drawings

Fig. 1 is a schematic view for exemplarily illustrating the structure of an electrolytic cell.

FIG. 2 is a perspective view showing an example of a conductive elastomer used in an electrolytic cell.

FIG. 3 is a schematic perspective view for explaining the combination of the diaphragm-interposed electrolytic cell units with each other.

Fig. 4 is a partially enlarged schematic view of an expansion alloy for explaining the width dimension (W) of the strands.

FIG. 5 is a schematic cross-sectional view in the horizontal direction of an exemplary embodiment of an electrolytic cell.

Fig. 6 is a schematic cross-sectional view for explaining an electrolytic cell provided as an embodiment of the present invention.

Fig. 7 is a schematic sectional view for explaining bending of the electrode tip.

Fig. 8 is a schematic cross-sectional view for explaining a mode of sandwiching a thin plate-like member at a bent end portion.

Fig. 9 is a schematic cross-sectional view for explaining a manner of sandwiching the wire member at the bent end portion.

Fig. 10 is a schematic cross-sectional view for explaining an exemplary manner of positioning of the end edge.

Fig. 11 is a schematic cross-sectional view for explaining an end portion approaching member provided at an electrode end portion.

Fig. 12 is a schematic cross-sectional view for explaining a mode of providing a thin plate-like member as the end portion approaching member.

Fig. 13 (a) to (c) are schematic cross-sectional views of the electrodes for explaining "approach".

Fig. 14 is a schematic cross-sectional view for explaining a mode of providing a linear member as an end approaching member.

Fig. 15 is a schematic cross-sectional view for explaining a mode in which a thin plate-like member is provided as an end approaching member with respect to a bent end.

Fig. 16 is a schematic cross-sectional view for explaining a mode of providing a linear member as an end approaching member with respect to a bent end.

Fig. 17 is a schematic cross-sectional view for explaining a mode in which the end portion access member is disposed above.

Fig. 18 is a schematic cross-sectional view for explaining a manner in which the electrode edge is sealed by the end portion approaching member.

Fig. 19 is a schematic cross-sectional view for explaining an intervening member provided between an electrode and an electrode base.

Fig. 20 is a schematic cross-sectional view for explaining a mode of providing a thin plate-like member as an intervening member.

Fig. 21 is a schematic cross-sectional view for explaining a mode of providing a linear member as an intervening member.

Fig. 22 is a schematic cross-sectional view for explaining a mode in which a thin plate-like member is provided as an intervening member between a bent electrode and an electrode base.

Fig. 23 is a schematic cross-sectional view for explaining a mode in which a linear member is provided as an intervening member between a bent electrode and an electrode base.

Fig. 24 is a schematic cross-sectional view for explaining a mode in which a thin plate-like member is provided as an intervening member between an electrode bent in a meandering manner and an electrode base.

Fig. 25 is a schematic cross-sectional view for explaining a mode in which a linear member is provided as an intervening member between an electrode bent in a meandering shape and an electrode base.

Fig. 26 is a schematic cross-sectional view for explaining a combination manner of the thin plate-like member and the electrode tip portion bending.

Fig. 27 is a schematic cross-sectional view for explaining a combination manner of the thin plate-like member and the electrode tip portion bending.

Fig. 28 is a schematic cross-sectional view for explaining a mode in which a thin plate-like member is provided as an intervening member in a non-end region other than an end region of an electrode.

Fig. 29 is a schematic cross-sectional view for explaining a mode in which a linear member is provided as an intervening member in a non-end region other than an end region of an electrode.

Fig. 30 (a) to (e) are schematic diagrams showing various modifications of the bending of the electrode end portion.

Fig. 31 (a) to (e) are schematic diagrams showing various modifications of the bending of the electrode end portion.

Fig. 32 (a) to (d) are schematic diagrams showing various modifications of the bending of the electrode end portion.

Fig. 33 (a) to (d) are schematic diagrams showing various modifications of the bending of the electrode end portion.

Fig. 34 (a) to (d) are schematic diagrams showing various modifications of the bending of the electrode end portion.

Fig. 35 (a) to (d) are schematic diagrams showing various modifications of the bending of the electrode end portion.

Fig. 36 (a) and (b) are schematic views showing various modifications of the bending of the electrode end portion.

Fig. 37 (a) to (e) are schematic views showing various modifications of the electrode end portion.

Fig. 38 (a) to (e) are schematic diagrams showing various modifications of the bending of the electrode end portion.

Fig. 39 (a) to (e) are schematic diagrams showing various modifications of bending of the electrode end portion.

Fig. 40 (a) to (g) are schematic diagrams showing various modifications of the bending of the electrode end portion.

Fig. 41 (a) to (g) are schematic diagrams showing various modifications of the bending of the electrode end portion.

Fig. 42 (a) to (d) are schematic diagrams showing various modifications of the bending of the electrode end portion.

Fig. 43 (a) to (j) are schematic diagrams showing various modifications of the bending of the electrode end portion.

Fig. 44 (a) to (j) are schematic diagrams showing various modifications of the end proximity member provided to the electrode end.

Fig. 45 (a) to (d) are schematic diagrams showing various modifications of the end proximity member provided to the electrode end.

Fig. 46 (a) and (b) are schematic views showing various modifications of the end proximity member provided to the electrode end.

Fig. 47 is a schematic cross-sectional view for explaining a use mode of a conventional pin for fixing an electrode.

Fig. 48 is a schematic view for explaining a sharp electrode end edge.

Description of the reference numerals

100-an electrolyzer unit; 100' -an electrolyzer unit; 100' -cell unit; 150-a support frame for the electrodes; 200-electrodes (in particular electrodes for electrolysis); 200A-cathode; 200B-anode; 210-strand; 250-the ends of the electrodes; 250' -bent or serpentine portion; 252 — outermost edge of the bent end; 255-end edges of electrodes; 257-a bend region; 257A — first bend portion; 257B — second bend portion; 258 — the maximum bend displacement portion of the electrode; 280-electrode base (e.g. cathode base); 300-membrane (e.g., ion exchange membrane); 400-a conductive elastomer; 450-an elastic portion; 500-end access component (cushion intervening component); 540-thin plate-like member; 560-a linear member; 580-edge sealing means; 600-an intervening component; 640-a thin plate-like member; 640A-an upper sheet-like member; 640B-a thin plate-like member of the lower side; 660-a linear member; 700-a stamping unit; 800-conventional electrode fixation pins; 850-flange portion.

Detailed Description

The electrode structure according to an embodiment of the present invention will be described in more detail below with reference to the drawings. The various elements in the drawings are shown schematically and illustratively for the understanding of the present invention, and may differ from actual ones in appearance, size ratio, etc.

The present invention relates to an electrode structure for an electrolytic cell. In the present specification, the term "electrolytic cell" refers broadly to an apparatus for performing electrolysis, and refers narrowly to an apparatus comprising at least an anode, a cathode, and a separator provided between the electrodes. Therefore, in the present specification, "electrode structure" refers to a structure relating to an electrode of an apparatus for performing electrolysis in a broad sense, and refers to a structure of an electrode (i.e., an anode and/or a cathode) and a relevant portion thereof in the apparatus in a narrow sense. Therefore, the "electrode structure" in the present invention may also be referred to as an "electrode structure" for an electrolytic cell, an "electrolytic cell structure" or the like, and may be simply referred to as an "electrode" as necessary.

In the present specification, "up-down" and "left-right" directions directly or indirectly described correspond to the up-down direction and the left-right direction in the drawings, respectively. More specifically, for example, in the embodiment shown in fig. 7, the direction along the planar direction of the electrode corresponds to the left-right direction, and the direction orthogonal thereto corresponds to the up-down direction. In the operation of the electrolytic cell, the electrode of the type shown in fig. 7 and the like is generally used in a vertical orientation as shown on the left side of fig. 3 and 6 (that is, the electrode is generally used in an orientation that is changed by substantially 90 ° from the state of fig. 7). Therefore, the orientation of the cell or its constituent elements may be different between when the electrolytic cell is used (particularly, when the electrolytic cell is operated in a state in which the cells constituting the electrolytic cell are combined with each other) and when the electrolytic cell is not used (particularly, when the cell is not operated before the cells constituting the electrolytic cell are combined with each other).

The various numerical ranges set forth in this specification also include the lower and upper numerical values themselves. That is, for example, if a numerical range of 1 to 10 is taken as an example, the explanation is that "1" including the lower limit value and "10" including the upper limit value are included.

First, the basic structure of the electrolytic cell on which the present invention is based will be described, and then the features of the present invention will be described. Also, in the following description, an electrode for electrolysis, i.e., an electrode for electrolysis, is also simply referred to as an "electrode", or more specifically, an "anode" or a "cathode".

[ basic Structure of electrolytic cell ]

The electrode structure of the invention is used in an electrolytic cell having at least an anode, a cathode and a separator arranged between these electrodes. The anode and the cathode are electrodes for supplying electric energy to the electrolyte solution from the outside. The anode is typically an electrode connected to the positive electrode of an external power supply, and is an electrode capable of causing an oxidation reaction during operation of the electrolytic cell. On the other hand, the cathode is typically an electrode connected to the negative electrode of the external electrode, and is an electrode capable of causing a reduction reaction during operation of the electrolytic cell.

The diaphragm is typically a member that separates the anode and cathode chambers. The separator is preferably arranged to avoid mixing of the substance produced by the anode with the substance produced by the cathode. In the present invention, the separator may be conventionally used for electrolysis. For example, the membrane is an ion exchange membrane. For example only, in an electrolytic cell used in the alkali industry, a cation exchange membrane may be used as a diaphragm.

The electrolytic cell may be provided with a conductive elastomer. The conductive elastomer contributes to the electrical conduction between the electrodes due to its "conductivity", and can exert a pressing force on the electrodes due to its "elasticity". That is, the conductive elastic body corresponds to a conductive member capable of providing a reaction force in the electrolytic cell, and has at least a structure capable of being elastically deformed in order to provide the reaction force.

Figure 1 schematically illustrates an exemplary construction of an electrolytic cell. As shown in the drawing, in the electrolytic cell, a conductive elastomer is used for an electrode assembly composed of at least an anode, a cathode, and an ion exchange membrane between these electrodes. In such an electrolytic cell, the reaction force of the conductive elastomer is used to press an electrode assembly composed of at least an anode, a cathode, and an ion exchange membrane between these electrodes. Specifically, the conductive elastic body is used in a state of being elastically deformed on the back surface side of the electrode assembly, and a pressing force is applied to the electrode assembly by an elastic force (i.e., a reaction force) provided by the conductive elastic body. In particular, the conductive elastic body that is elastically deformed functions to apply a pressing force from one electrode to the other electrode, thereby promoting adhesion of the electrode assembly. That is, the presence of the conductive elastomer brings the anode, the ion exchange membrane, and the cathode into close contact with each other, and the electrolytic cell can satisfactorily exhibit the function of the so-called "zero-pitch" type.

The conductive elastic body used in the electrolytic cell may have any form as long as it generates an elastic repulsive force. The conductive elastomer may have, for example, the following various forms: an elastic cushion member, an elastic pad (for example, a member made of a metal coil body, a metal nonwoven fabric, a woven or knitted fabric made of metal wires, or the like), a leaf spring, or the like. As a specific example, the conductive elastic body 400 may have an elastic portion 450 that is curved in a wave-like manner as shown in fig. 2. The conductive elastic body is used in a state of being elastically deformed in order to exhibit spring characteristics in the electrolytic cell. More specifically, the conductive elastomer is provided in the electrolytic cell in a state of being deformed so that the wavy curve of the elastic portion is reduced, for example. In the conductive elastic body thus deformed, a reaction force is generated as a spring characteristic due to a stress for restoring the original shape. In addition, in general, in a large electrolytic cell, a plurality of conductive elastic bodies are provided instead of using a single conductive elastic body.

In the electrolytic cell, the electrode may be formed of, for example, a conductive base material having liquid permeability. In this regard, at least one of the anode and the cathode is preferably composed of a conductive porous substrate. In other words, at least one of the anode and the cathode may be a mesh opening electrode having mesh openings. For example, the electrode may be made of an expanded alloy, a metal mesh (plain mesh, twill mesh), a punched metal, or the like.

In a preferred embodiment, both the anode and the cathode may have a conductive porous substrate. For example, both electrodes may be formed of an expanded alloy or a plain weave mesh, or one electrode may be formed of an expanded alloy and the other electrode formed of a plain weave mesh. That is, both the anode and the cathode may have an expanded mesh or a plain mesh, or one of the anode and the cathode may have an expanded mesh and the other may have a plain mesh. Each of the anode and the cathode may contain at least one selected from the group consisting of titanium, nickel, stainless steel, tantalum, zirconium, niobium, and the like, from the viewpoint of enabling corrosion resistance and the like to be obtained. Further, an appropriate catalyst may be supported on each of the anode and the cathode. The aperture ratio of the conductive porous substrate is not particularly limited, and may be about 20% to 90%, for example, 30% to 80%, 40% to 75%, or 50% to 75%.

Preferably, the electrolytic cell is composed of a plurality of electrolytic cell units. Each cell unit has at least an electrode and a support frame supporting the electrode. Preferably, the support frame supports the electrodes to facilitate the arrangement of the electrodes in a planar manner, and constitutes a frame portion of the unit. Therefore, the electrode unit has a form in which the electrode is disposed on the side surface thereof, and the electrode is disposed so as to occupy most of the side surface of the unit. The electrolytic cell can be configured by combining the electrode cell units having the electrodes on the side surfaces thereof with each other via the separators.

The electrolytic cell is preferably of the zero-pole pitch type. The electrode structure thus has characteristics suitable for such a zero-pitch type. As one of such characteristics, the anode and the cathode have characteristics in terms of so-called "hardness" and "softness" such as rigidity and flexibility of the electrode material. Specifically, one of the anode and the cathode is preferably flexible relative to the other, and the other is preferably rigid relative to the one. Accordingly, the electrode having flexibility can be deflected while receiving the reaction force of the conductive elastic body, and the electrode having rigidity can resist the deflection via the ion exchange membrane. From such a viewpoint, if the anode and the cathode are relatively different, the anode, the ion exchange membrane, and the cathode are more closely attached to each other, and the electrolytic cell can more preferably function as a "zero-pole-pitch type". This configuration is particularly suitable when the electrolytic cell is large. That is, the present invention is particularly suitable for a case where the main surface of the electrode which needs to be pressed to realize zero-pitch is large, such as a case of zero-pitch salt electrolysis.

In order to obtain a larger amount of desired electrolytic product, a larger electrolytic cell is used, but the main surface of the electrode (particularly, the main surface where the anode and the cathode face each other) becomes larger. The large zero-pitch electrolyzer is preferably composed of a plurality of electrolyzer units each having a large main electrode surface on each of the opposite side surfaces. By way of example only, a so-called "multi-pole" electrolytic cell will be described with reference to fig. 3, in which a cathode 200A (for example, a cathode surface made of an expanded alloy) is provided on one of two opposite side surfaces of the cell unit 100, and an anode 200B (for example, an anode surface made of an expanded alloy) is provided on the other of the two side surfaces. In the electrolytic cell, a plurality of such electrolytic cell units are connected to each other via an ion exchange membrane 300 (particularly, a cation exchange membrane) so as to overlap each other. In particular, in the adjacent electrolytic cell units, the cathode surface of one electrolytic cell unit 100' and the anode surface of the other electrolytic cell unit 100 ″ are overlapped so as to face each other. The electrolytic cell is constituted by combining a plurality of electrolytic cell units via the ion exchange membrane in this manner. The electrolytic cell including a plurality of electrolytic cell units is not limited to the "multi-pole type", and may be a "single-pole type". That is, the electrolytic cell unit constituting the electrolytic cell is not limited to a multi-pole type electrolytic cell unit having an anode section and a cathode section on both opposite side surfaces, and may be a "single-pole type" electrolytic cell unit having only an anode section and only a cathode section on both opposite side surfaces. In this case, the electrolytic cell may be configured by alternately arranging the electrolytic cell unit including only the anode section and the electrolytic cell unit including only the cathode section through the ion exchange membrane.

In the electrolytic cell comprising the electrolytic cell unit, it is preferable that the size of the major surface of the electrode is relatively large and the desired electrolytic reaction is carried out by the relatively large electrode surface, but it is difficult to ensure the flatness of the electrode surface. Specifically, the larger the size of the electrode main surface is, the more the influence of the deflection or the like due to its own weight is not negligible, and the influence of the mounting or the like on the electrode support is also significant, and it is difficult for the electrode main surface to be a completely flat surface. For example, in the electrolytic cell unit 100 (100', 100 ") illustrated in fig. 3, the major surface size of the anode surface and the cathode surface is not in the order of several cm but in the order of m. Even when the electrode is made rigid in order to obtain a preferable flat surface, flatness of the major surface of the electrode is as large as ± 0.5mm to 1.0mm, for example, and it is difficult to obtain a completely flat surface (that is, flatness of 0mm) for the above reasons. In other words, in a large-sized electrolytic cell, the following tendency is exhibited: the rigid electrode main surface is relatively flat in macroscopic view, but is a surface accompanied by local unevenness in microscopic view.

If the electrodes having not completely flat surfaces are brought into close contact with each other through the ion exchange membrane, unevenness may impair the uniformity of the current distribution. Therefore, in a preferred electrolytic cell, the electrode paired with the rigid electrode is made a softer flexible electrode than the rigid electrode. As a result, even if the electrodes are strongly adhered to each other via the ion exchange membrane, the flexible electrode is bent so as to follow the irregularities of the rigid electrode surface, and thus, it is possible to prevent unevenness and the like of the current distribution. For example, the anode may be formed of a relatively rigid, relatively hard expansion alloy and the cathode may be formed of a relatively soft, flexible expansion alloy. The conductive elastic body may be provided on the back surface side of the flexible expansive alloy of the cathode combined with the rigid expansive alloy of the anode via the ion exchange membrane. In this case, the flexible expansion alloy of the cathode is pressed against the rigid expansion alloy of the anode by the reaction force of the conductive elastomer, but the flexible expansion alloy of the cathode can be locally displaced in accordance with the flatness of the main surface of the rigid expansion alloy of the anode. Therefore, even under the condition that the electrolytic cell units are strongly fastened to each other and the reaction force of the conductive elastic body acts to a large extent, the anode, the ion exchange membrane, and the cathode can be brought into close contact with each other well, and defects such as non-uniformity of current distribution are less likely to occur.

Although not particularly limited, the thickness of the relatively hard and rigid expansion alloy is preferably about 0.2 to 2.0mm due to "relative rigidity", and the width (step size) (portion indicated by "W" in fig. 4) of the strands 210 constituting the porous or open portion is preferably about 0.2 to 2.0 mm. Similarly, although not particularly limited, the flexible expansive alloy is preferably 0.1 to 1.0mm thick, more preferably 0.1 to 0.5mm thick, and the width (step size) (portion indicated by "W" in fig. 4) of strands constituting the opening, which is a porous structure, is preferably 0.1 to 2.0mm, more preferably 0.1 to 1.5mm thick, because of "relative flexibility". When a metal mesh or a punched metal is used as the flexible electrode, the thickness is preferably about 0.1 to 1.0mm, and more preferably about 0.1 to 0.5mm, for example, because of "flexibility in relative terms". In the case of the metal mesh, the wire diameter φ, which represents the approximate diameter of the metal fibers constituting the metal mesh, is preferably on the order of 0.05 to 1.0mm, and more preferably on the order of 0.1 to 0.5 mm. In the case of punching metal, the length of the non-opening portion between adjacent opening portions may be about 0.1 to 2.0mm, and more preferably about 0.1 to 1.5 mm.

Figure 5 is shown for a further understanding of the cell. FIG. 5 corresponds to a cross-sectional view of an exemplary embodiment of the electrolytic cell as viewed from the vertical direction. That is, the cross-sectional view of the cell shown in fig. 3 (particularly, the combination of the cells of the electrolytic cell) cut in the horizontal transverse direction corresponds to fig. 5. In the embodiment shown in fig. 5, the flexible cathode 200A of an expansion alloy, the separator 300, and the rigid anode 200B of an expansion alloy are arranged in this order, and the conductive elastic body 400 is provided on the back surface side of the cathode 200A (i.e., on the opposite side of the installation side of the separator 300). Since the conductive elastic body 400 is provided so as to be deformed to narrow between the cathode 200A of the expanded alloy and the cathode base 280 (more specifically, a plurality of electrolytic cell units connected to each other are fastened to each other to form such a narrow width and cause deformation of the conductive elastic body), the elastic force of the conductive elastic body 400 directly acts on the flexible cathode 200A of the expanded alloy which is in direct contact with the elastic portion of the conductive elastic body 400. As a result, the flexible cathode 200A of the expanded alloy is urged so as to be pressed against the rigid anode 200B of the expanded alloy, and the flexible cathode 200A, the separator 300, and the rigid anode 200B are brought into close contact with each other. In addition, since the rigid anode itself, which is an electrode not in direct contact with the conductive elastomer, is fixed to an electrode support or the like of the electrolytic cell unit so as not to move, it acts against the elastic force of the conductive elastomer, and contributes to the realization of close contact.

As a specific example: the cell unit provided with rigid anodes is constituted at least by rigid anodes and a support frame supporting them. On the other hand, an electrolytic cell unit provided with a flexible cathode is composed of at least an electrically conductive electrode base, a support frame for supporting the electrode base, an electrically conductive elastic body provided on the electrode base, and a flexible cathode disposed on the electrically conductive elastic body. The electrode base may have a higher rigidity than the flexible cathode at least for supporting the flexible cathode.

[ features of the invention ]

The present invention relates to the electrode structure of the electrolytic cell. In particular, the present invention is characterized by various electrode forms including the arrangement mode of the electrodes. Specifically, the electrode structure has at least any one of the following (I) to (III).

(I) At least one of the anode and the cathode is bent such that an end portion thereof is meandering in a cross-sectional view.

(II) at least one of the anode and the cathode has an end-approaching member disposed in proximity to the end thereof.

In the present invention, any one of the electrode structures (I) to (III) can suppress damage to the separator.

In the electrolytic cell, the damage of the separator can be suppressed by the specific shape of the electrode end portion in the (I). More specifically, the electrode for electrolysis of at least one of the anode and the cathode is bent at its end in a meandering manner, and the risk of damage to the separator can be reduced by such an electrode. In particular, even when the edge of the end portion of the electrolysis electrode has a relatively sharp shape, the "meandering" can suppress damage to the separator.

In the aspect (II), damage to the separator of the electrolytic cell can be suppressed by the end proximity member provided at the end of the electrode. More specifically, at least one of the anode and the cathode of the electrolytic cell is lined with an end approach member at the end thereof, thereby reducing the risk of damage to the separator due to the electrode. In particular, even if the edge of the end portion of the electrode has a relatively sharp form, damage to the separator can be suppressed due to the presence of the end portion proximity member.

In the case of (III), damage to the separator can be suppressed due to the intervening member provided between the electrode and the electrode base. More specifically, the electrode is at least one of an anode and a cathode, and is attached and fixed to the electrode base portion via an intervening member between the electrode and the electrode base portion. That is, when the electrode is fixed to the support member via the intervening member, the intervening member is located between the electrode and the support member and does not directly contact the diaphragm. This means that: the intervening member can fix the electrode to the support and suppress damage to the separator.

Thus, the present invention provides an electrolytic cell technology that can satisfactorily prevent a failure caused by damage to a separator.

In a preferred embodiment of the present invention, in the electrolytic cell, the edge of at least one of the electrodes does not contact the separator between the anode and the cathode. That is, the edge of the electrode does not contact the separator provided between the anode and the cathode due to the "peculiar form of the electrode end", "the end approach member provided at the electrode end", and/or "the intervening member provided between the electrode and the electrode base thereof". That is, the edges of the electrodes of the electrode structure of the present invention preferably do not directly contact the separator, in a spaced or separated state therebetween. For example, the edge does not directly contact the major surface of the diaphragm. By such non-contact, the separator can be more reliably prevented from being damaged in the present invention. The "edge" referred to herein corresponds to an edge of an end of the electrode, and thus may be referred to as an "end edge". The "edge" also corresponds to an edge forming the outer periphery, and therefore may be referred to as an "outer peripheral edge".

The following describes the details of the above-mentioned (I) to (III), respectively. In the present invention, based on the respective features, (I) is also referred to as an electrode structure relating to "meandering of the electrode end portion", "II) is also referred to as an electrode structure relating to" use of the end portion proximity member ", and (III) is also referred to as an electrode structure relating to" use of the intervening member ".

Snake bending of electrode tip

In the above-mentioned (I), at least one of the anode and the cathode used as the electrolysis electrode is bent so that its end portion is meandering in a cross-sectional view.

Fig. 6 and 7 schematically show the form of the end of the electrolysis electrode. Fig. 6 and 7 show partial cross sections of the electrolytic cell units, and show the forms at the time before the electrolytic cell units are combined with each other. That is, fig. 6 and 7 show a state before the conductive elastic body exhibits spring characteristics by fastening the cell units, that is, a state before the diaphragm and the electrode are in close contact with each other. As can be seen in particular from fig. 7: the end portion 250 of the electrolysis electrode 200 is bent largely, particularly in a meandering manner.

If the electrode end portion is bent in a meandering shape, the effect of suppressing damage to the separator in the electrolytic cell can be exhibited. The end edges of the electrodes used in the electrolytic cell generally have a relatively sharp form, but the influence of the sharp end edges can be reduced and damage to the separator can be suppressed in the present invention.

In the electrode for electrolysis, particularly, the end edge (i.e., the edge forming the outermost edge of the electrode) is easily sharpened. This is because the electrodes are generally porous or open. That is, in the porous or open-cell electrode, the end edge thereof tends to be sharp. This is because, as shown in fig. 48, the electrode 200 for an electrolytic cell may have sharp edges that "produce barbs" due to a plurality of wires that form a plurality of holes or openings. In other words, it can be said that the electrode composed of the conductive porous substrate is likely to have a sharp edge at the end due to the wire constituting the porous or open end thereof. The sharp edge of the end portion easily damages the separator, but in the electrode for electrolysis of the present invention, the separator damage is suppressed by the "zigzag-shaped bending" of the end portion.

The effect of "meandering of the electrode end" will be described in detail. In such an electrode structure, the edge 255 of the electrode 200 is easily arranged in the electrolytic cell so as not to contact the separator 300 by "meandering of the electrode end portion 250" (see fig. 7). That is, the bending of the electrode ends displaces the position of the electrode edges (in particular the peripheral/outer edge of the electrode), reducing the risk of the electrode edges and the membrane coming into direct contact with each other when the cell is in use. In particular, by making the electrode end portion meander, the edge of the electrode can be made farther away from the separator, and damage to the separator can be more effectively suppressed. Further, by making the bending meandering, an appropriate stress can be applied to the electrode. Preferably, the meandering shape causes stress to be generated at the electrode end portion to promote adhesion between the electrode and the separator, thereby facilitating adhesion between the anode, the ion exchange membrane, and the cathode. Therefore, the "meandering" of the electrode end makes it easy to make the electrolytic cell function better as a "zero-pole-pitch type". From the above description, it can be seen that: in the "meandering of the electrode end portion", the electrode end portion is not bent for fixation of the electrode (particularly fixation of the electrode on the electrode base portion), but is bent for reducing a possibility of causing a failure such as damage of the separator at the edge of the electrode. Therefore, the "meandering of the electrode tip" in the present invention may be referred to as a meandering for preventing damage to the separator.

In the present specification, "bent in a meandering manner" refers to a form in which the electrode end portion extends in a reciprocating manner in a cross-sectional view. In the present invention, therefore, the electrode tips at least partially overlap each other due to the "meandering".

In a preferred form, the bend in the electrode tip is continuous. That is, the end portion of at least one of the anode and the cathode may be bent several times in a reciprocating manner in a cross-sectional view. This makes it possible to more reliably separate the edge of the electrode from the separator and to easily generate stress at the end of the electrode, which promotes the adhesion between the electrode and the separator. Therefore, it is possible to realize a zero-pitch system that promotes close contact between the anode, the ion exchange membrane, and the cathode, and to suppress damage to the separator more effectively.

In addition, it can be said that the electrode end portion 250 is bent in a serpentine shape so as to form at least two bent portions. In the embodiment shown in fig. 7, when the end portion 250 of the electrode 200 is bent largely, the bent end portion is bent twice so that the bent end portions overlap each other. When the electrode end is thus bent, the electrode edge can be more reliably moved away from the separator. In addition, such bending can also appropriately generate stress at the electrode end portion to promote adhesion of the electrode to the separator.

The bent portion of the end portion 250 of the electrode may have a profile as shown in fig. 7. That is, the bent portion 257 of the electrode tip 250 may have a curved sectional shape. With the electrode end portion having such a configuration, it is possible to reduce the adverse effect that may be caused on the separator by the bent portion. That is, since the cross-sectional profile of the bent portion is relatively smooth without any edge, the diaphragm is less likely to be damaged even when the bent portion temporarily contacts the ion exchange membrane in the electrolytic cell. Further, if the electrode is broken or cut at the bent portion of the electrode end, the separator is likely to be damaged, but according to the present invention, even if stress that causes the electrode to be broken or cut is generated at the bent portion, stress concentration is unlikely to occur, and the electrode can be prevented from being broken or cut.

In the present invention, it is preferable that an end of at least one of the anode and the cathode is bent on the opposite side to the side where the separator is located. This is because the bending direction of the electrode tip is located on the more distant position side with respect to the separator. That is, by bending the electrode so as to be away from the separator, the edge of the electrode can be more reliably away from the separator, and the effect of suppressing damage to the separator is improved. The phrase "the end portion is bent on the side opposite to the side on which the separator is provided" as used herein broadly means that the electrode is bent in a direction in which the end edge of the electrode for electrolysis is farther from the separator. In a narrow sense, the ends of the electrodes for electrolysis are bent in such a way as to overlap each other, so that the end edges of the electrodes are located at a further distance from the separator in the electrolytic cell. In the embodiment shown in fig. 7, the end portion 250 of the electrode is folded downward and overlapped, and therefore the end edge 255 is positioned not close to the separator 300 but close to the electrode base 280 on which the electrode is provided.

In a preferred embodiment, the electrode end portion of the electrolysis electrode of at least one of the anode and the cathode is bent so as not to straddle the electrode base portion on which the electrode is provided. As shown in fig. 7, in the structure in which the relatively soft electrode 200A (for example, the electrode 200A formed of the conductive porous substrate) is disposed in the electrode base 280 together with the conductive elastic body 400, the electrode end portion 250 extends so as not to cross over the electrode base 280. In the illustrated embodiment, the electrode base 280 is provided with the meandering bent portion 250' of the end portion 250 of the electrolysis electrode.

The electrode base 280 is a conductive member, and generally has higher rigidity than the electrode 200A. If the electrode base is provided with the meandering curved portion, more appropriate stress is easily generated on the electrode end portion. When the electrolytic cell is used, the electrode is in a fastened state between the diaphragm and the electrode base, because the end portion of the electrolysis electrode that is meandering can be more appropriately sandwiched between the diaphragm and the electrode base to generate a reaction force. That is, by sandwiching the electrolysis electrode between the separator and the electrode base in a state in which the electrode end is bent so as not to straddle the electrode base, stress that promotes the adhesion of the electrolysis electrode to the separator is likely to be generated at the electrode end.

As described above, in the case where the electrode 200 for electrolysis is porous or open, the edge of the electrode end is particularly easily sharpened (see fig. 48), but in the present invention, the influence of the sharp edge is suppressed by the "zigzag folding" of the electrode end. In other words, it can be said that the effects of the present invention are easily exhibited when the electrode used in the electrolytic cell is composed of the conductive porous substrate. More specifically, when the electrolysis electrode of at least one of the anode and the cathode is a mesh-open electrode made of, for example, an expanded alloy, a metal mesh (plain mesh, twill mesh), or a punched metal, and the end of such a mesh-open electrode is bent in a meandering manner, the effect of suppressing damage to the separator is easily exhibited.

Similarly, the effect of the present invention is also readily exhibited when the separator used in the electrolytic cell is an ion exchange membrane. The ion exchange membrane used in the electrolytic cell is relatively thin, for example, about 0.1 to 0.5mm, and is generally made of a material relatively softer than the electrode (for example, as a cation exchange membrane used in the electrolytic cell, a flexible membrane made of a fluororesin membrane having a cation exchange group may be used). Therefore, when an ion exchange membrane is used in an electrolytic cell, the ion exchange membrane is generally easily damaged by an electrode for electrolysis. Therefore, when the electrolysis electrode of at least one of the anode and the cathode is a conductive porous base material made of metal, and the separator directly opposed to the electrode is an ion exchange membrane, the effect of suppressing damage to the separator is easily exhibited.

The "meandering shape of the electrode end" can be formed by any method. For example, the electrode tip portion can be bent in a serpentine shape by using an appropriate pressing means and/or an appropriate gripping means (means for gripping the electrode tip portion or the like). Typically, the electrolysis electrode can be bent in a meandering manner by applying an external force to the end portion thereof. In this case, it is preferable that the bending is performed by applying an external force at a point before the electrolytic cell units are combined with each other.

The bending operation of the end portion of the electrode for electrolysis is performed at least once, that is, at least one bent portion may be formed at the end portion of the electrode. Preferably, the bending operation is performed at least twice on the electrode tip, i.e., at least two bending portions are preferably formed at the electrode tip. The upper limit of the number of times of bending/the bending portion is not particularly limited, and is, for example, 10 times/10, more specifically, 3 times/4. In addition, the width dimension of the region of the electrode end portions overlapping each other by bending, that is, the width dimension of the meandering bent region (for example, the dimension of "L" shown in the cross-sectional view of fig. 10 referred to below) may be on the order of 1mm to 3cm, more specifically, on the order of 1mm to 5 mm.

The "meandering of the electrode tip" is characterized in that the electrode tip is bent as described above so that the edge of the electrode used for the electrolytic cell does not cause damage to the separator. Such bending of the electrode end can be embodied in various ways. This will be explained below.

(form of member held at end)

In this embodiment, an additional member is provided at an end of the electrolysis electrode so as to be sandwiched therebetween. Specifically, a thin plate-like member or a linear member is sandwiched between bent end portions. In the embodiment shown in fig. 8, a thin plate member 540 is provided so as to be sandwiched between the end portion 250 bent in a meandering manner; in the embodiment shown in fig. 9, a linear member 560 is provided so as to be sandwiched between the end portions 250 bent in a meandering manner.

The thin plate-like member or the linear member may be made of various materials such as metal or resin, and the production method thereof is not particularly limited. Preferable materials for the thin plate-like member or the linear member include corrosion-resistant materials such as nickel, stainless steel, and fluorine resin. The "thin plate-like member" referred to in the present specification means a member having a shape extending thinly in a plate shape or a thin plate shape as a whole, as the name implies. As the thin plate-like member, for example, a foil-like member can be used. The term "linear member" as used herein refers to a member having a long and thin shape like a "linear shape", as the name implies. The wire may be a metal wire, for example. For example, the thin plate-like member may be a "thin plate" and thus may be thinner than the thickness of the electrode (e.g., a mesh-open electrode). Similarly, the thickness (cross-sectional dimension) of the linear member may be smaller than the thickness of the electrode (e.g., mesh opening electrode). However, the present invention is not limited to such a dimensional relationship, and the thickness of the thin plate-like member or the thickness of the linear member may be larger than the thickness of the electrode (e.g., mesh opening electrode).

The thin plate-like member or the linear member may be used for mounting the electrode to the electrode base. That is, the electrode and the electrode base may be joined to each other by a thin plate-like member or a linear member sandwiched at the bent end portions. In the arrangement in a plan view, a thin plate-like member or a linear member may be provided for at least one of the sides (i.e., at least one side) constituting the outer peripheral edge of the electrode. In this case, it is preferable to provide a long thin plate-like member or a linear member along the one side.

For example, a thin plate-like member or a linear member may be used for welding. That is, the electrode base and the electrode (particularly, the bent electrode end) may be welded to each other via a thin plate-like member or a linear member. This enables the electrolysis electrode to be fixed to the electrode base with a more appropriate attachment force. Since the thin plate-like member or the linear member is provided locally in the electrode, it can be said that spot welding can be performed via such a member. When the "welding" is set, it is preferable that the thin plate-like member or the linear member is made of a meltable material that can be temporarily melted by a welding gun, a light beam, or the like. In this regard, the thin plate-like member and the linear member may be, for example, metal members. The metal used for the metal component is preferably at least one selected from the group consisting of titanium, nickel, stainless steel, tantalum, zirconium, niobium, and the like, in view of corrosion resistance and the like. The thin plate-like member may be, for example, a metal foil, and may be, for example, a nickel foil. Similarly, the linear member may be, for example, a metal wire, and may be, for example, a nickel wire. Nickel foil or wire is particularly suitable in terms of both corrosion resistance and welding properties.

The presence of the thin plate-like member or the linear member itself can promote the effect of suppressing damage to the separator. That is, due to the presence of the thin plate-like member or the linear member, it is easy to realize a manner in which the end edges of the electrodes are farther apart or spaced farther apart with respect to the separator. For example only, when the thin plate-like member is located above the end edge of the electrode, the end edge of the electrode is covered with the thin plate-like member, and the effect of suppressing damage to the separator is particularly likely to be improved. Further, the linear member does not have a large surface like a thin plate-like member and is difficult to be used as a member for covering the edge of the end portion, but it can relatively well act on a product (for example, a gaseous product) generated from the electrode during the operation of the electrolytic cell due to its small shape. Specifically, since the linear member is thin, the flow of the generated gas generated by the electrode is not easily obstructed, and inappropriate retention of the gas is easily prevented. In the case of using a linear member, only one linear member may be used, or a plurality of linear members may be used.

Further, a thin plate-like member or a linear member may also be used for the bending operation of the electrode tip. In this case, the thin plate-like member or the linear member is brought into contact with the electrode end portion and the member is sandwiched inside, thereby contributing to the bending operation of the electrode end portion. Further, the thin plate-like member or the linear member not only contributes to the bending operation, but also suppresses bending failure of the electrode end portion due to the thickness, and the like, and facilitates formation of a smooth bent portion in a curved shape.

(means of preferred location of end edge)

In this embodiment, the edge is arranged at a specific position at the end of the bent electrode for electrolysis. As shown in the cross-sectional view of fig. 10, the end edge 255 of the electrode 250 is located further inboard than the outermost edge 252 of the bent end 250. That is, the end edge 255 of the electrode 250 does not exceed the outermost edge 252 of the bent end 250. In this manner, the bent end portion 250 'is interposed between the electrode edge 255 and the separator 300, and thus the electrode edge 255 is more reliably covered with the bent end portion 250'. Therefore, the electrode edge 255 can be isolated from the separator 300 to further reduce the influence of the electrode edge 255, and the effect of suppressing the separator damage can be more improved.

For example, the position of the end edge 255 (i.e., the "outer peripheral edge") of the electrolysis electrode 250 may be located approximately midway between the serpentine overlap regions. More specifically, as shown in fig. 10, when the end 250 of the electrode 200 of at least one of the anode and the cathode is bent to have a first bent portion 257A and a second bent portion 257B in a cross-sectional view, the end edge 255 may be located substantially midway between the first bent portion 257A and the second bent portion 257B in the direction of the electrode surface.

The term "substantially middle" as used herein does not necessarily mean a strict "middle", and may mean a form slightly deviated from the middle. For example, when the spacing distance between the first bent portion 257A and the second bent portion 257B is L in a cross-sectional view, the position of the edge 255 of the electrode tip in the electrode plane direction ("point a" shown in fig. 10) may be in the range of 0.4L to 0.6L from the first bent portion 257A ("point B" shown in fig. 10). Further, the "point a" may be in the range of 0.45L to 0.55L or in the range of 0.48L to 0.52L from the "point b".

In this aspect, the electrode is bent twice in a relatively simple "zigzag shape", and the bent end portion is more reliably interposed between the electrode edge and the separator. In particular, in the "middle", the electrode edge 255 can be more reliably covered with the bent end portion 250' as shown in fig. 10, and the influence of the electrode edge 255 can be further reduced. Therefore, the electrode edge can be more reliably isolated from the separator, and the effect of suppressing damage to the separator can be more improved.

(zero polar distance type special mode)

This embodiment is a specific embodiment of the zero-pitch type electrolytic cell. In the zero-pitch system, when the anode, the ion exchange membrane, and the cathode are in close contact with each other (see fig. 1), the ion exchange membrane is easily damaged by the electrodes in close contact with each other. Therefore, the effect of the present invention is easily exhibited when the electrolytic cell is a zero-pitch type electrolytic cell (for example, a zero-pitch type common salt electrolytic cell).

For example, when one of the anode and the cathode used as an electrode for electrolysis is flexible so as to face the other electrode, the anode, the ion exchange membrane, and the cathode can be brought into close contact with each other, which generally means that the ion exchange membrane is easily damaged. In the present invention, even under such a close contact condition, the edge of the electrode is easily arranged so as not to be in direct contact with the ion exchange membrane due to the "meandering" and damage to the ion exchange membrane can be suppressed. In other words, in this case, it can be said that one of the anode and the cathode has flexibility so as to be opposed to the other electrode, and the one electrode is bent in a meandering manner.

From the same viewpoint, if the conductive elastic body is provided in the electrolytic cell, the anode, the ion exchange membrane, and the cathode can be brought into close contact with each other, but this generally means that the ion exchange membrane is easily damaged. That is, when the conductive elastic body is provided on the back surface side of one of the anode and the cathode so that the conductive elastic body presses the other electrode, the conductive elastic body can be appropriately attached to the back surface side of the one electrode, but the ion exchange membrane is easily damaged. For example, when a cathode (particularly, a cathode composed of a conductive porous base material) is pressed toward an anode side via an ion exchange membrane, the conductive porous base material is generally likely to cause damage to the ion exchange membrane. Even under such conditions, in the present invention, the "zigzag-shaped bend" facilitates the arrangement in which the edge of the electrode does not directly contact the ion-exchange membrane, and damage to the ion-exchange membrane can be suppressed.

Use of end proximity Member

In the above (II), at least one of the anode and the cathode has an end-approaching member at an end thereof.

Fig. 11 and 12 schematically show the electrode tip shape based on the "use of the tip approach member". Fig. 11 and 12 are slightly different in the manner of arrangement of the end proximity members, but both show a partial cross section of the electrolytic cell unit and show the form of the electrolytic cell unit at the time before the electrolytic cell units are combined with each other. That is, fig. 11 and 12 show a state before the conductive elastic body exhibits spring characteristics by fastening the electrolytic cell units to each other, that is, a state before the diaphragm and the electrode are in close contact with each other. According to the mode of illustration, it can be seen that: in the electrode structure of the electrolytic cell, an additional member is provided on the electrode 200, and in this case, the end approaching member 500 is lined on the electrode end 250 as the additional member.

If the electrode is provided with an end-approaching member, the effect of suppressing damage to the separator in the electrolytic cell can be exhibited. As described above, especially the end edge (i.e., the edge forming the outermost edge of the electrode) is easily sharpened (see fig. 48). Although the sharp end edge easily damages the separator, the separator damage is suppressed by the "end approaching member" provided in the electrode structure of the electrolytic cell in the present invention.

The effect of the use of the end proximity member will be described in detail. In such an aspect, the "end approaching member" suppresses: the sharp portion of the edge 255 of the electrode 200 contacts the septum 300, for example, in a piercing manner. That is, the end proximity means provided for the electrodes perform a good function for the ends of the electrodes, reducing the risk of the edges of the electrodes and the membrane coming into improper contact with each other when the cell is in use. In particular, when the end portion approach member is provided so as to be in direct contact with the electrode end portion, the end portion approach member more effectively acts on the electrode end portion, and the adverse effect of the electrode edge on the separator is easily reduced.

In the present specification, the term "end portion approach member" broadly refers to an additional member provided in the electrolytic cell in proximity to the end portion of the electrode. In a narrow sense, the term "electrode" refers to a member provided as a separate member from various elements of the electrode (electrode or electrode base supporting the electrode) and the conductive elastic body at the electrode end located in a region outside the region where the conductive elastic body is disposed. Here, "close to" refers to a mode of being disposed very close to the electrode end, and includes a case of being in contact with the electrode end. That is, the "proximity" used in the present specification includes a manner of being at least partially in contact with the electrode end portion, and also includes a manner which can be regarded as being equivalent to this manner. As a specific indicator, such "approaching" corresponds to a mode in which the end approaching member is located at least partially in a circular region (for example, a circular region having a radius of about 6 cm) centered around the edge of the electrode end in the electrode cross-sectional view shown in fig. 13 (a) to (c).

As can be seen from fig. 11 and 12: the end portion approaching member 500 is disposed in a region above the electrode base portion 280 supporting the electrode 200. Furthermore, from the sectional views shown: the end proximity member 500 is preferably disposed on the electrode base 280 and is provided so as to at least partially overlap the end 250 of the electrode 200. The type of the end portion approach member is not limited as long as it acts on the electrode end portion to reduce the adverse effect of the electrode edge on the separator. For example, the end proximity member may have conductivity. The end proximity member having conductivity may contribute to the electrical conduction between the electrodes. The end-approaching member may have a thin plate-like or linear shape, for example. That is, the end portion approaching member lined at the end portion of the electrode may be a thin plate-like member or a linear member. Since the thin plate-like member is a "thin plate", its thickness may be thinner than that of the electrode (e.g., a mesh-open electrode). Similarly, the thickness (cross-sectional dimension) of the linear member may be smaller than the thickness of the electrode (e.g., mesh opening electrode). However, the dimension relationship is not limited to this, and the thickness dimension of the thin plate-like member or the thickness dimension of the linear member may be larger than the thickness dimension of the electrode (e.g., mesh opening electrode).

In the exemplary embodiment shown in fig. 12, a thin plate-like member 540 is provided as the end approaching member at the end 250 of the electrode. In the illustrated embodiment shown in fig. 14, a linear member 560 is provided as the end approaching member at the end 250 of the electrode. From such a diagram, it can be seen that: the end proximity member 500 may be disposed on a position side farther than the electrode 200 with respect to the diaphragm 300. That is, the end proximity member 500 may be disposed farther than the electrode 200 as viewed from the separator 300. Preferably, as illustrated, the end access member 500 is located between the electrode 200 and the electrode base 280 on which the electrode is disposed.

When the end portion approaching member is disposed on the far side as described above, the end portion approaching member cannot directly contact the diaphragm. On the other hand, if the separator is in direct contact with the end proximity member in the electrolytic cell, that is, if the end proximity member is in direct contact with the separator, a large load is applied to the separator, and the separator may be damaged depending on the degree of the load. In this regard, according to the present invention, the end access member 500 (fig. 12 and 14) disposed relatively on the far side easily avoids such direct contact, and can excellently prevent the membrane from being damaged by the end access member.

In a preferred embodiment, the thin plate-like member or the linear member is used for fixing the electrode end portion. That is, it is preferable to fix the position of the electrode end portion by a thin plate-like member or a linear member. More specifically, the electrode tip is attached to the electrode base by interposing a thin plate-like member or a linear member as the tip approaching member. This means that: the electrode and the electrode base are joined to each other by a thin plate-like member or a linear member. The use of such an end proximity member contributes to fixation or position fixation of the electrode edge, and thus it is easy to further reduce the adverse effect of the electrode edge on the separator. In the arrangement in a plan view, a thin plate-like member or a linear member may be provided for at least one of the sides (i.e., at least one side) constituting the outer peripheral edge of the electrode. In this case, it is preferable to provide a long thin plate-like member or a linear member along the one side.

Various manners of engagement are contemplated. For example, welding may be performed as the mutual joining of the electrode and the electrode base. That is, the electrode base and the electrode may be welded to each other via a thin plate-like member or a wire member used as the end portion approaching member. This enables the electrode to be fixed to the electrode base with a more appropriate mounting force. Since the thin plate-like member or the wire member is provided locally in the electrode, it can be said that spot welding can be performed via such a member. When the "welding" is set, it is preferable that the thin plate-like member or the wire member is made of a meltable material that can be temporarily melted by a welding gun, a light beam, or the like. In this regard, the thin plate-like member and the wire member may be provided as a metal member, for example. In view of corrosion resistance, the metal of such a metal member is preferably at least one selected from the group consisting of titanium, nickel, stainless steel, tantalum, zirconium, niobium, and the like. The thin plate-like member may be, for example, a metal foil, and may be, for example, a nickel foil. Similarly, the wire member may be, for example, a metal wire, and may be, for example, a nickel wire. Nickel foil or wire is particularly suitable in terms of both corrosion resistance and welding properties.

In the case where the electrode base and the electrode are welded to each other via the end portion approaching member lined at the electrode end portion, the end portion approaching member may be located between the electrode base and the electrode. In the mode shown in fig. 12 and 14, the thin plate-like member 540 or the wire member 560 is disposed between the electrode base 280 and the electrode 200. In this way, when the end portion approaching member is positioned between the electrode base and the electrode, the bonding strength between the electrode base and the electrode is increased, so that the effect of reducing the adverse effect of the electrode edge on the separator is easily sustained.

In the embodiment shown in fig. 12 and 14, the electrode tip is lined with the tip approaching member so as not to be particularly bent, but as shown in fig. 15 and 16, the tip approaching member 500 may be provided in the bent electrode tip 250.

In fig. 15, the electrode tip 250, which is bent to a large extent, is lined with a thin plate-like member 540; in fig. 16, the wire member 560 is lined at the electrode end portion 250 bent to a large extent. As shown, the electrode tip 250 is preferably bent and a tip access member 500 is preferably clamped at the bent tip 250. If the end portion is bent, the edge 255 of the electrode 200 is more easily arranged so as not to contact the separator 300. Therefore, if the end proximity member is used in the manner shown in fig. 15 and 16, damage to the diaphragm can be more effectively suppressed.

As can be seen from the manner shown in fig. 15: it may be provided that the thin plate-like member 540 is located above the end edge 255 of the electrode. More specifically, the thin plate-like member 540 is preferably sandwiched between the bent electrode end 250 and is disposed so as to extend beyond the end edge 255 of the electrode. This makes it possible to cover the edge of the electrode with the thin plate-like member, and in particular, to easily improve the effect of suppressing damage to the separator. Further, the linear member does not have a large surface as a thin plate-like member and is difficult to be used as a member for covering the edge of the end portion, but the linear member can relatively effectively act on a product (for example, a gaseous product) generated from the electrode during the operation of the electrolytic cell because of its narrow shape. Specifically, since the linear member 560 (see fig. 16) has a thin shape, the flow of the generated gas generated by the electrode is less likely to be obstructed, and inappropriate retention of such gas is likely to be prevented. In the case of using a linear member as the end-approaching member, only one linear member may be used, or a plurality of linear members may be used.

The bent portion of the end portion 250 of the electrode may have a contour configuration as shown in fig. 15 and 16. That is, the bent portion 257 of the electrode tip 250 may have a curved sectional shape. With the electrode end portion having such a configuration, it is possible to reduce the adverse effect that may be caused on the separator by the bent portion. That is, since the cross-sectional profile of the bent portion is relatively smooth without any edge, the separator is less likely to be damaged even when the bent portion temporarily contacts the separator in the electrolytic cell. Further, if the electrode is broken or cut at the bent portion of the electrode end, the separator is likely to be damaged, but according to the present invention, even if stress that causes the electrode to be broken or cut is generated at the bent portion, stress concentration is unlikely to occur, and the electrode can be prevented from being broken or cut.

As can be seen from the manner shown in fig. 15 and 16: in the electrode structure having the end approaching member, the electrode end 250 is preferably bent at the side opposite to the side where the separator 300 is located. This is because the bending direction of the electrode tip is located on the more distant position side with respect to the separator. That is, by bending the electrode so as to be away from the separator, the edge of the electrode can be more reliably away from the separator, and the effect of suppressing damage to the separator can be further improved. The term "the end portion is bent on the side opposite to the side on which the separator is provided" as used herein means that the electrode is bent in a direction in which the end edge of the electrode is farther from the separator.

Similarly, the modes shown in fig. 15 and 16 show that: in the electrode 200 including the end proximity member, the electrode end is preferably bent so as not to straddle the electrode base 280 on which the electrode is provided. For example, in a structure in which the relatively soft electrode 200A (e.g., the electrode 200A composed of the conductive porous substrate) is disposed in the electrode base 280 together with the conductive elastomer, the electrode end portion 250 does not extend so as to cross over the electrode base 280. According to the illustrated embodiment, the bent portion 250' of the electrode tip 250 is disposed on the electrode base 280 together with the tip approaching member 500. In addition, the electrode base 280 is a conductive member, generally has higher rigidity than the electrode 200A, and can be used to support the flexible electrode 200A and the end portion approaching member 500. In a preferred embodiment, if the end portion approach member is sandwiched between the electrodes in a state where the electrode end portion is bent so as not to straddle the electrode base, stress that promotes the electrode and the separator to be in close contact with each other is likely to be generated at the electrode end portion.

When the electrode end portion 250 is bent, the electrode end portion may be bent in a meandering manner. That is, the thin plate-like member 540 or the linear member 560 may be provided so as to be sandwiched by the end portion 250 bent in a meandering manner (see fig. 8 and 9). By bending the electrode end in a meandering manner in this manner, the electrode edge can be easily moved farther away from the separator, and damage to the separator can be suppressed more effectively. In addition, the electrode can be given an appropriate stress by bending in a meandering manner. Preferably, the electrode is bent in a meandering manner, so that stress for promoting adhesion between the electrode and the separator can be generated at the end of the electrode, and adhesion between the anode, the ion exchange membrane, and the cathode can be promoted.

As described above, in the case where the electrode 200 included in the electrode structure of the electrolytic cell is porous or open, the edge of the electrode end portion is particularly easily sharpened (see fig. 48). In other words, it can be said that the effect of the present invention is easily exhibited when the electrode in the electrode structure of the present invention is composed of the conductive porous substrate. More specifically, when at least one of the anode and the cathode is a mesh-open electrode made of, for example, an expanded alloy, a metal mesh (plain mesh, twill mesh), or a punched metal, and the end portion of such a mesh-open electrode and the "end-portion-approaching member" are used together, the effect of suppressing damage to the separator is easily exhibited. Similarly, the effect of the present invention is also easily exhibited when the diaphragm of the electrolytic cell is an ion exchange membrane. As described above, when an ion exchange membrane is used for the electrode structure of an electrolytic cell, the ion exchange membrane is generally easily damaged by the electrode of the electrolytic cell. Therefore, when at least one of the anode and the cathode is a metal conductive porous substrate and the separator directly opposed to the electrode is an ion exchange membrane, the effect of suppressing damage to the separator is easily exhibited.

The end proximity member can be provided by any method. For example, the end portion approaching member which is preliminarily formed into a desired shape may be provided to the electrode at a point of time before the electrolytic cell units are combined with each other. In the case of welding or the like via the end proximity member, the end proximity member may be positioned at the electrode end by a conventional method, followed by heat treatment by a welding gun, a light beam, or the like.

In the case where the electrode tip is bent and the tip approaching member is used, the electrode tip may be bent by any method. For example, the electrode end portion can be bent by using an appropriate pressing means and/or an appropriate gripping means (means for gripping the electrode end portion or the like). Typically, the electrode can be bent by applying an external force to the electrode tip. In this case, it is preferable that the bending is performed by applying an external force at a point before the electrolytic cell units are combined with each other.

In the electrode structure relating to "use of the end proximity member", as described above, the end proximity member is provided at the electrode end so that the edge of the electrode does not cause damage to the separator. Such an invention can be embodied in various ways. This will be explained below.

(mode in which the end part is arranged above the approach part)

In this embodiment, an end approaching member is provided at the electrode end. As shown in the cross-sectional view of fig. 17, the end access member 500 covers the electrode end 250. Specifically, the end portion approaching member 500 is provided so as to cover at least the electrode edge 255 from above. For example, the end access member 500 may be provided in a manner extending beyond the electrode edge 255 to the support frame 150 of the electrode. According to the mode of illustration, it can be seen that: this can be said to be the case where the end proximity member 500 is disposed closer to the separator 300 than the electrode 200.

In this embodiment, the end access member 500 is interposed between the electrode edge 255 and the separator 300, and thus the electrode edge 255 is more reliably covered with the end access member 500 in the intervening configuration. Therefore, the electrode edge 255 can be isolated from the separator 300 to more reliably reduce the influence of the electrode edge 255, in which point the effect of suppressing damage to the separator can be improved.

(means for edge sealing)

In this embodiment, the edge of the electrode is sealed by the end-approaching member. As shown in fig. 18, the end proximity member 500 is provided to the electrode end 250 and directly to the edge 255 of the end. According to the mode of illustration, it can be seen that: this means that the end proximity member 500 surrounds at least a portion of the peripheral edge 250 of the electrode 200. The term "surrounding" as used herein means surrounding the end portion approaching member so that at least a part of the edge of the end portion does not come out or is not exposed.

In this case, since there is an end approach member 500 for surrounding so that exposure of the outer peripheral edge 255 of the electrode is reduced or eliminated, the influence of the sharp end edge can be directly reduced. In the manner shown in the cross-sectional view of fig. 18, the end access member 500 contacts the end edge and encases the end edge and its vicinity.

The material of the end proximity member for surrounding is not particularly limited. When importance is attached to ease of arrangement, the end proximity member preferably includes resin. Examples of the resin include corrosion-resistant materials such as fluorine-based resins. In one preferred mode, the end approaching member may be provided as an edge sealing member 580 obtained by sealing the edge with a resin material. The fluorine-based resin used as the edge sealing member 580 may be at least one selected from the group consisting of PTFE (tetrafluoroethylene resin), PFA (tetrafluoroethylene perfluoroalkoxyethylene copolymer resin), PVDF (vinylidene fluoride resin), ETFE (tetrafluoroethylene ethylene copolymer resin), FEP (tetrafluoroethylene hexafluoropropylene copolymer resin), and PCTFE (chlorotrifluoroethylene resin), for example. The resin used AS the edge sealing member 580 is not limited to a fluorine-based resin, and at least one selected from the group consisting of an epoxy resin, a UV epoxy resin, an unsaturated polyester resin, a polyamide resin, an epoxy resin, a phenol resin, a vinyl chloride resin, a vinyl acetate resin, a polyurethane resin, an ABS resin, an AS resin, an AAS resin, an ethylene vinyl chloride copolymer resin, a butyral resin, an ethylene vinyl acetate copolymer resin, a polyimide resin, a polyacetal resin, a polyethylene resin, a polycarbonate resin, a styrene maleic acid resin, a polysulfone resin, a melamine resin, a urea resin, a xylene resin, a coumarone resin, a ketone resin, a maleic acid resin, a polyvinyl alcohol, a polyvinyl ether, a polyterpene resin, a terpene phenol resin, an acrylic resin, and the like may be used.

(means relating to the material of the end-approaching member)

This embodiment is a method specific to the material of the end proximity member. In a preferred mode, the end proximity member includes at least a metal material. In this case, not only the strength required for the end-approaching member can be provided, but also the corrosion resistance of the end-approaching member is preferable. For example, titanium, nickel, stainless steel, etc. are preferable in terms of strength and corrosion resistance required for the end portion close to the member. In particular, when the electrode base and the electrode are welded to each other via the end portion approaching member, the end portion approaching member preferably contains a metal material. In this case, the electrode can be appropriately attached to the electrode base, and the electrolytic cell has good strength and corrosion resistance, and contributes to stable operation of the electrolytic cell over a long period of time.

In another mode, the end proximity member includes at least a resin material. In this case, the end portion approaching member can be provided with appropriate flexibility, and even if the end portion approaching member temporarily contacts the diaphragm, adverse effects of the end portion approaching member can be reduced. In addition, since the end-approaching member made of a resin material can be provided by supplying a resin precursor having variability or fluidity to the electrode end and then curing the resin precursor, the end-approaching member can be provided in any form at the electrode end. As a specific resin material, there is no particular limitation, and for example, a fluorine-based resin can exhibit good corrosion resistance.

(zero polar distance type special mode)

This embodiment is a specific embodiment of the zero-pitch type electrolytic cell. Since the zero-pitch system can closely contact the anode, the ion exchange membrane, and the cathode as described above (see fig. 1), the effect of "use of end-approaching members" is easily exhibited. For example, if one of the anode and the cathode is flexible relative to the other, it is possible to make a better close contact between the anode, the ion exchange membrane, and the cathode, and even under such a close contact condition, it is possible to easily reduce the influence of the electrode edge on the ion exchange membrane and suppress damage to the ion exchange membrane by using the "end proximity member" provided at the electrode end. That is, in this aspect, one of the anode and the cathode has flexibility to be opposed to the other electrode, and an end proximity member is provided to the one electrode.

From the same viewpoint, the use of the "end proximity member" can suppress damage to the ion exchange membrane even under conditions where the conductive elastic body is provided in the electrolytic cell and damage to the ion exchange membrane is likely to occur. That is, the "end portion approaching member" provided at the end portion of the electrode can easily reduce the influence of the edge of the electrode on the ion exchange membrane, thereby suppressing damage to the ion exchange membrane.

Use of interventional component

In the above-described (III), at least one of the anode and the cathode is attached to the electrode base portion via an intervening member between the electrode and the electrode base portion (i.e., the electrode base portion on which the electrode is provided).

Fig. 19 and 20 schematically show an exemplary form of the electrode regarding "use of an intervening member". Fig. 19 and 20 show partial cross sections of the electrolytic cell units, and show the form at the time before the electrolytic cell units are combined with each other (the separators are shown together with the electrolytic cell units for understanding the invention). That is, fig. 19 and 20 show a state before the conductive elastic body exhibits spring characteristics by fastening the combined electrolytic cell units to each other, that is, a state before the diaphragm and the electrode are brought into close contact with each other. According to the mode of illustration, it can be seen that: the electrode 200 used in the electrolytic cell is attached to the electrode base 280, and in this case, an intervening member 600 is provided between the electrode 200 and the electrode base 280.

The intervening member 600 joins the electrode 200 and the electrode base 280 to each other between them. The intervening member 600 for attaching the electrode 200 to the electrode base 280 is provided between the electrode 200 and the electrode base 280 as the name implies, and preferably does not include a portion located in an upper region of the electrode 200. Therefore, the intervening member 600 becomes a member that is used for mounting of the electrode in the electrolytic cell and can suppress the risk of itself causing damage to the separator.

As shown in fig. 47, a conventional pin 800 for fixing an electrode is used from above the electrode 200 so as to press the electrode 200 from above. Therefore, the conventional fixing pin 800 includes a portion (e.g., a flange 850 shown) located in an upper region of the electrode 200, and is in a state of being able to directly contact the ion exchange membrane. The pin is a member capable of applying a large load to the ion exchange membrane in the electrolytic cell, and may damage the ion exchange membrane depending on the degree of the load. In contrast, the intervening member 600 of the present invention does not include a portion located in a region above the electrode 200 (i.e., a portion located on the upper side or the diaphragm side with respect to the electrode), and avoids direct contact with the diaphragm 300 (see fig. 19 and 20). Therefore, the present invention can preferably prevent the damage of the diaphragm caused by the intervention member 600.

In the present description, "intervening component" refers broadly to an additional component disposed between an electrode and its supporting component in an electrolytic cell or cell unit. The term "intervening member" is used in the narrow sense to mean a member which is located in a region between an electrode and an electrode base (a conductive electrode base capable of being provided with or mounted on the electrode and functioning as a support for the electrode) in the cross-sectional view shown in the present application and which is in contact with both of them at least partially. Preferably the intervening component is located only between the electrode and its electrode base.

In addition, in the present specification, "interposed between the same and the electrode base" means a region located between the electrode and the electrode base employed in the electrolytic cell or the electrolytic cell unit. Or, macroscopically, the intervening component is located between the electrode and the electrode base. Therefore, in the case of bending of the electrode end portion (fig. 22 to 27) described later, the intervening member is sandwiched between the electrode end portion and, macroscopically, the intervening member is positioned between the electrode and the electrode base portion.

As can be seen from fig. 19 and 20: the intervention member 600 is disposed in a region above the electrode base 280 supporting the electrode 200. Further, the intervening member 600 is preferably disposed on the electrode base 280 and disposed to at least partially overlap the electrode 200 (e.g., the end 250 thereof).

Further, it can be said that the intervening member 600 is disposed on the position side farther than the electrode 200 with respect to the diaphragm 300. That is, the intervening member 600 is farther away from the electrode 200 as viewed from the diaphragm 300. This means that: even if the electrolytic cell units are combined with each other, the electrode 200 and the separator 300 are closely attached to each other, there is no case where the intervening member 600 is located between the electrode and the separator, eliminating or reducing direct contact of the intervening member 600 with the separator 300. Therefore, in the present invention, even under the condition that the electrode 200 and the separator 300 are in close contact with each other, the separator is well prevented from being damaged by the intervening member 600 for fixing the electrode.

The intervening member 600 is not limited in type as long as it is located between the electrode and its electrode base and facilitates the mounting or fixation of the electrode. For example, the intervening component may be electrically conductive. The intervening member exhibiting conductivity can facilitate the electrical conduction between the electrodes. The intervening member may be in the form of a thin plate or a wire, for example. That is, the member located between the electrode and the electrode base thereof for mounting or fixing the electrode may be a thin plate-like member or a linear member. The thin plate-like member may be thinner than the thickness of the electrode (e.g., a mesh opening electrode) because it is a "thin plate". The thin plate-like member may be in the form of a foil, for example. Similarly, the thickness (cross-sectional dimension) of the linear member may be smaller than the thickness of the electrode (e.g., mesh opening electrode). However, the present invention is not limited to such a dimensional relationship, and the thickness of the thin plate-like member or the thickness of the linear member may be larger than the thickness of the electrode (e.g., mesh opening electrode).

In the exemplary embodiment shown in fig. 20, the thin plate-like member 640 is used as an intervening member for mounting the electrode 200. In the exemplary embodiment shown in fig. 21, the linear member 660 is used as an intervening member for mounting the electrode 200. From such a diagram, it can be seen that: the intervening member 600 is located between the electrode 200 and the electrode base 280 in the electrolytic cell or cell unit and facilitates the fixation of the electrode 200.

In the case where an intervening member such as a thin plate-like member or a linear member contributes to the attachment or fixation of the electrode, it is preferable that the electrode and the electrode base are joined to each other through the intervening member. That is, the intervening member between the electrode 200 and the electrode base 280 functions as a bonding material for these members, and the electrode 200 is attached to the electrode base 280.

The material of such an intervening member is not particularly limited as long as it contributes to "joining". For example, the intervening component may comprise at least a metallic material. The metal material is particularly suitable when the joining by the intervening members is welding (the manner of "welding" will be described later). In the case of a metal material, it is preferable to provide not only the strength required for the intervening member but also the corrosion resistance and the like of the intervening member. For example, titanium, nickel, stainless steel, etc. are preferable based on the strength, corrosion resistance, etc. required for the intervening member.

In the present invention, the intervening member is not limited to being composed of only a metal material. The intervening member may also be a member containing a resin material. An intervening member containing a resin material is particularly likely to exhibit adhesiveness. Such an intervening member may also be provided as an adhesive that bonds the electrodes and the electrode base to each other between them. In the case of a resin material, the intervening member can be provided with appropriate flexibility, and even if the electrode portion provided with the intervening member comes into contact with the separator, the influence of the electrode portion can be reduced. Further, since the intervening member made of a resin material can be provided by supplying a resin precursor having variability or fluidity and then curing the resin precursor, the intervening member can be easily provided in any form at any position. As a specific resin material, for example, a fluorine-based resin is preferable because it can exhibit good corrosion resistance. The fluorine-based resin may be at least one selected from the group consisting of PTFE (tetrafluoroethylene resin), PFA (tetrafluoroethylene perfluoroalkoxyethylene copolymer resin), PVDF (vinylidene fluoride resin), ETFE (tetrafluoroethylene ethylene copolymer resin), FEP (tetrafluoroethylene hexafluoropropylene copolymer resin), and PCTFE (chlorotrifluoroethylene resin). The resin material is not limited to fluorine-based resins, and at least one selected from the group consisting of epoxy resins, UV epoxy resins, unsaturated polyester resins, polyamide resins, epoxy resins, phenol resins, vinyl chloride resins, vinyl acetate resins, polyurethane resins, ABS resins, AS resins, AAS resins, ethylene vinyl chloride copolymer resins, butyral resins, ethylene vinyl acetate copolymer resins, polyimide resins, polyacetal resins, polyethylene resins, polycarbonate resins, styrene maleic acid resins, polysulfone resins, melamine resins, urea resins, xylene resins, coumarone resins, ketone resins, maleic acid resins, polyvinyl alcohols, polyvinyl ethers, polyterpene resins, terpene phenolic resins, and acrylic resins may be used.

Various manners are contemplated based on the manner of engagement of the intervening components. For example, welding may be performed as the mutual joining of the electrode and the electrode base. That is, the electrode base and the electrode may be joined to each other by using the intervening member as a welding member. In the case of using a thin plate-like member or a linear member, the electrode base and the electrode may be welded to each other via the thin plate-like member or the linear member. This enables the electrode to be fixed to the electrode base with a more appropriate fixing force. Since intervening members such as thin plate-like members or linear members may be provided locally in the electrodes, it can also be said that spot welding can be performed via such members. When "welding" is set, the intervening member is preferably made of a fusible material that can be temporarily melted by a welding gun, a light beam, or the like. In this regard, the intervening member such as the thin plate-like member and the wire member may be a metal member, for example. The metal of the metal component is preferably at least one selected from the group consisting of titanium, nickel, stainless steel, tantalum, zirconium, niobium, and the like, in view of corrosion resistance and the like. The thin plate-like member may be, for example, a metal foil, and may be, for example, a nickel foil. Similarly, the wire member may be, for example, a metal wire, and may be, for example, a nickel wire. Nickel foil or wire is particularly suitable in terms of both corrosion resistance and welding properties.

In the present invention, it is preferable that the electrode and the electrode base are joined to each other via an intervening member, regardless of whether the bonding method or the welding method is used. Therefore, the intervening member can also be referred to as a "joining member" or the like in the present invention.

In a preferred embodiment, an intervening member is provided at least in an end region of the electrode. That is, as shown in fig. 19 and 20, for example, the intervening member 600 may be provided as a member different from various elements of the electrode (electrode or electrode base supporting the electrode) and the conductive elastic body at the electrode end 250 located in the region outside the region where the conductive elastic body 400 is arranged. If the intervening member is provided at the end of the electrode, the effect of suppressing damage to the separator can be obtained also from the viewpoint of "end edge" of the electrode. This is because, in the end region, the electrode is mounted with an intervening member provided between the electrode and the electrode base, so that the electrode edge is fixed or positionally fixed, and the adverse effect of the electrode edge on the separator is more easily reduced. In the arrangement in a plan view, a thin plate-like member or a linear member may be provided for at least one of the sides (i.e., at least one side) constituting the outer peripheral edge of the electrode. In this case, it is preferable to provide a long thin plate-like member or a linear member along the one side.

As described above, in the case where the electrode 200 included in the electrode structure of the electrolytic cell is porous or open, the edge of the electrode end portion is particularly apt to be sharpened (see fig. 48), but if the "intervening member" is provided at the electrode end portion and the edge of the end portion is fixed or the position thereof is fixed, it is possible to suppress damage to the separator due to such a sharp edge.

That is, in the case where the intervening member is provided in the end region of the electrode, there is no portion located in the upper region of the electrode in the electrode mounting member, direct contact with the diaphragm is avoided, and by fixing the end edge or position by such mounting, the inconvenience of the sharp portion of the edge coming into contact with the diaphragm, for example, in a piercing manner, is suppressed. Therefore, this embodiment can preferably suppress damage to the separator during operation of the electrolytic cell. The term "end region of the electrode" as used herein refers to a peripheral region of the electrode in a broad sense, and refers to a peripheral region of, for example, about 1mm to 3cm (about 1mm to 5mm in some cases) from the edge of the electrode (the outermost edge of the electrode) to the inside in a narrow sense.

In the embodiment shown in fig. 20 and 21, the electrode end portion 250 is not particularly bent and the intervening member 600 is provided, but as shown in fig. 22 and 23, the intervening member 600 may be provided at the bent electrode end portion 250.

As shown in fig. 22, the electrode end portion 250 bent largely is lined with a thin plate-like member 640 as an intervening member, and as shown in fig. 23, the electrode end portion 250 thus bent is lined with a linear member 660 as an intervening member. As illustrated, the intervening member 640 may be positioned between the electrode 200 and the electrode base 280 in such a manner that the electrode tip 250 is bent and the intervening member 600 is sandwiched between the bent end 250. If the end portion is bent, the edge 255 of the electrode 200 is more easily arranged so as not to contact the separator 300. That is, when the intervention member 600 is used as shown in fig. 22 and 23, the damage of the septum can be more effectively suppressed. In addition, as in the case of the embodiments of fig. 20 and 21, since the intervening member 600 is disposed on the side of the separator 300 that is farther than the electrode 200 (particularly, the electrode portion other than the edge 255 and the vicinity thereof), the intervening member 600 does not directly contact the separator 300, and in this regard, the separator can be prevented from being damaged.

As can be seen from the mode shown in fig. 22, the thin plate-like member 640 provided as an intervening member may have a portion located above the end edge 255 of the electrode. More specifically, the thin plate-like member 640 may be clamped at the bent electrode end 250 and extend beyond the end edge 255 of the electrode. This makes it possible to cover the edge of the electrode with the thin plate-like member, thereby easily improving the effect of suppressing damage to the separator. As shown in fig. 22, at least a part of the edge 255 may be covered with the interposed member 600. Further, the linear member does not have a large surface like a thin plate-like member and is difficult to be used as a member for covering the edge of the end portion, but the linear member can relatively effectively act on a product (for example, a gaseous product) generated from the electrode during the operation of the electrolytic cell due to its narrow shape. Specifically, since the linear member 660 (see fig. 23) has a thin shape, the flow of the generated gas generated by the electrode is not easily obstructed, and inappropriate retention of the gas is easily prevented. In the case of using a linear member as the intervening member, only one linear member may be used, or a plurality of linear members may be used.

The bent portion of the end portion 250 of the electrode may have a contour form as shown in fig. 22 and 23. That is, the bent portion 257 of the electrode tip 250 may have a curved sectional shape. With the electrode end portion having such a configuration, it is possible to reduce the adverse effect that may be caused on the separator by the bent portion. That is, as described above, the cross-sectional profile of the bent portion is relatively smooth without any edge, and therefore, even when the bent portion temporarily comes into contact with the separator in the electrolytic cell, the separator is less likely to be damaged. Further, if the electrode is broken or cut at the bent portion of the electrode end, the separator is likely to be damaged, but even if stress that causes the electrode to break or cut is generated at the bent portion, stress concentration is unlikely to occur, and the electrode can be prevented from breaking or cutting.

As can be seen from the manner shown in fig. 22 and 23: in the electrode structure having an intervening member, it is preferable that the electrode tip 250 is bent on the side opposite to the side where the separator 300 is located. This is because the bending direction of the electrode tip is located on the more distant position side with respect to the separator. That is, by bending the electrode so as to be away from the separator, the edge of the electrode can be more reliably away from the separator, and the effect of suppressing damage to the separator is further improved. The term "the end portion is bent on the side opposite to the side where the separator is present" as used herein means that the electrode is bent in a direction in which the end edge of the electrode is farther from the separator.

Similarly, as can be seen from the modes shown in fig. 22 and 23: in the electrode 200 provided with an intervening member, the end portion is preferably bent so as not to straddle the electrode base portion 280 on which the electrode is provided. For example, in a structure in which a relatively soft electrode 200A (e.g., an electrode 200A composed of a conductive porous substrate) is disposed on the electrode base 280 together with a conductive elastomer, the electrode end portion 250 extends so as not to cross over the electrode base 280. According to the illustrated embodiment, the bent portion 250' of the electrode tip 250 is disposed on the electrode base 280 together with the intervening member 600. In addition, the electrode base 280 is a conductive member, generally having higher rigidity than the electrode 200A, and is useful for supporting the flexible electrode 200A and the intervening member 600. In a preferred embodiment, if the intervening member is sandwiched between the electrodes in a state where the electrode end portion is bent so as not to straddle the electrode base portion, stress that promotes the close contact between the electrodes and the separators is likely to be generated at the electrode end portion. When the electrode tip 250 is bent, it may be bent in a meandering manner as shown in fig. 24 and 25. More specifically, the intervening member 600 such as the thin plate-like member 640 or the linear member 660 may be disposed so as to be sandwiched between the end portions 250 bent in a meandering manner. By making the electrode end portion meander, the edge of the electrode can be easily moved farther away from the separator, and damage to the separator can be suppressed more effectively. Further, by making the bending meandering, an appropriate stress can be applied to the electrode. Preferably, the meandering shape causes stress to be generated at the electrode end portion to promote adhesion between the electrode and the separator, thereby facilitating adhesion between the anode, the ion exchange membrane, and the cathode.

As described above, in the case where the electrode 200 of the electrolytic cell or the electrolytic cell unit is porous or open, the conventional pin for fixing the electrode is in a state of being able to contact the separator, but in the present invention, the intervening member 600 is actually located only between the electrode 200 and the electrode base 280, and therefore, the member for fixing the electrode is not in contact with the separator or such contact is reduced. In addition, in the case where the electrodes 200 of the electrolytic cell or the electrolytic cell unit are porous or open, the edges of the electrode ends are easily sharpened (see fig. 48), but according to the present invention, if an intervening member is used in the region of the electrode ends, the influence of the sharp edges can be suppressed. In other words, when the electrode used in the electrode cell or the electrolytic cell unit of the present invention is composed of the conductive porous substrate, it can be said that the effect of the present invention is easily exhibited. More specifically, when at least one of the anode and the cathode is a mesh-open electrode made of, for example, an expanded alloy, a metal mesh (plain mesh, twill mesh), or a punched metal, and such a mesh-open electrode is used together with the "intervening member", the effect of suppressing damage to the separator is easily exhibited.

Similarly, the effect of the present invention is also readily exhibited when the separator used in the electrolytic cell is an ion exchange membrane. As described above, when an ion exchange membrane is used in an electrolytic cell, the ion exchange membrane is not only damaged by the pins of the electrolytic cell for fixing the electrodes, but also is generally easily damaged by the presence of the electrodes. Therefore, when at least one of the anode and the cathode is a metal conductive porous substrate and the separator directly opposed to the electrode is an ion exchange membrane, the effect of suppressing damage to the separator is easily exhibited.

The intervention member can be provided by any method. For example, an intervening member that is preliminarily formed into a desired shape may be provided on the electrode at a time before the electrolytic cell units are combined with each other. Thereafter, heat treatment may be performed for bonding via the intervening members. For example, in the case of welding the electrode and the electrode base portion with an intervening member, the intervening member may be positioned between the electrode and the electrode base portion, and then subjected to heat treatment with a welding torch, a light beam, or the like.

In the case where the electrode tip is bent and the intervening member is used, the electrode tip may be bent by any method. For example, the electrode end portion can be bent by using an appropriate pressing means and/or an appropriate gripping means (means for gripping the electrode end portion or the like). Typically, the electrode can be bent by applying an external force to the electrode tip. In this case, it is preferable that the bending is performed by applying an external force at a point before the electrolytic cell units are combined with each other.

In the electrode structure relating to the "use of an intervening member", as described above, the intervening member is provided between the electrode and the electrode base portion so that the electrode is attached to the electrode base portion. Such an invention can be embodied in various ways. This will be explained below.

(combination of thin plate-like member and electrode tip bending)

This embodiment is a method in which a thin plate-like member is provided and an electrode end portion is bent. In the illustrated embodiment shown in fig. 26 and 27, the thin plate-like member 640 is used as the intervening member 600 for mounting the electrode, and the electrode end portion 250 is bent with respect to the thin plate-like member 640.

In the embodiment of fig. 26, a thin plate-like member 640 is disposed on the electrode base 280, and the electrode end portion 250 bent is provided on the thin plate-like member 640. The electrode tip 250 is bent in such a manner that: so that the end edge 255 of the electrode is located on the upper surface of the thin plate-like member 640 disposed on the electrode base 280. As shown, the thin plate-like member 640 may be provided directly on the electrode base 280, and the end edge 255 of the electrode may be positioned in relatively close proximity to or in contact with the upper surface of the thin plate-like member 640. That is, in the electrode 200, the electrode end portion 250 is bent to the opposite side to the diaphragm 300 side, and the edge 255 of the bent electrode end portion 250 is positioned on the upper side of the thin plate-like member 640 rather than the lower side. The electrode 200 is interposed between the end edge 255 and the separator 300, and therefore the influence of the "sharp edge" is suppressed, enabling the suppression of damage to the separator in the electrolytic cell.

In this manner, a region further inward than the end edge 255 may be joined. That is, the joining may be performed in a region further inside than the end edge in the plane direction of the electrode. With regard to fig. 26, the electrode 200 and the electrode base 280 may be joined via the thin plate-like member 640 at "point a". The electrode 200, the thin plate-like member 640, and the electrode base 280 may be joined to each other at a position further inward than the end edge 255. The joining may be welding, for example spot welding. The thin plate-like member 640 is made of metal, and when spot welding is performed as joining, the current at the time of spot welding can be further stabilized, and stronger joining can be achieved. In this embodiment, the electrode end is bent in such a manner that: positioning an end edge of the electrode on an upper surface of a thin plate-like member provided as an intervening member on the electrode base; also, the joint portion may be present in a region further inside than the end edge. The "joint portion" is preferably a portion where the electrode 200, the thin plate-like member 640, and the electrode base 280 are joined to each other. In the case of welding, the "joint" corresponds to a welded portion.

In the mode of fig. 27, the thin plate-like members 640 are provided in pairs on the upper and lower sides. The upper thin plate-like part 640A has at least a portion located above the end edge 255 of the electrode. On the other hand, the lower thin plate-like member 640B is located below the end edge 255 of the electrode as a whole. The lower thin plate-like member 640B corresponds to the thin plate-like member 640 in fig. 26 described above. That is, the electrode tip 250 is bent in such a manner that: so that the end edge 255 of the electrode is located on the upper surface of the thin plate-like part 640B arranged directly on the electrode base 280. In this embodiment, the end edge 255 of the electrode is sandwiched between the upper thin plate-like member 640A and the lower thin plate-like member 640B, and therefore the effect of suppressing damage to the diaphragm is further enhanced.

In the embodiment of fig. 27, a region inside the end edge 255 may be joined as in the embodiment of fig. 26. That is, the joining may be performed in a region further inside than the end edge in the plane direction of the electrode. With regard to fig. 27, the electrode 200 and the electrode base 280 may be joined via the thin plate-like member 640 at "point a". The electrode 200, the upper and lower thin plate-

like members

640A and 640B, and the electrode base 280 may be joined to each other at a position further inward than the end edge 255. The joining may be welding, for example spot welding. The thin plate-like members 640 are made of metal, and when welding is performed as the joining, the current at the time of spot welding can be further stabilized, and the joining can be further secured. In this embodiment, the electrode end is bent in such a manner that: such that the end edge of the electrode is located on the upper surface of the thin plate-like member provided as an intervening member on the electrode base (particularly such that the end edge of the electrode is located on the upper surface of the thin plate-like member on the lower side); also, the joint portion may be present in a region further inside than the end edge. Preferably, there may be a portion where the electrode 200, the thin plate-like member 640, and the electrode base 280 are joined to each other in this region.

Although not limiting to the present invention, some more specific matters will be described with respect to the exemplary embodiment of fig. 26 and 27. The thin plate-like members 640(640A, 640B) may be, for example, metal foils. The electrode 200 may be a flexible electrode 200A, and may be a mesh opening electrode having a mesh opening, for example. In the case where welding is performed in a region inside the end edge 255 (particularly, in the case where spot welding is performed), the welded portion provided as the joint portion may be a spot-like welded portion.

(mode of non-end region)

In this embodiment, the intervening member is provided in a non-end region other than the end region of the electrode. In the exemplary embodiment shown in fig. 28, the thin plate-like member 640 is used as an intervening member for mounting the electrode, and particularly, the intervening member is provided in a region other than the electrode end portion. In the exemplary embodiment shown in fig. 29, the linear member 660 is used as an insertion member for attaching the electrode, and particularly, the insertion member is provided in a region other than the end of the electrode. In such an aspect, it can be said that the thin plate-like member and/or the linear member is provided as the intervening member in a region of the electrode other than the non-peripheral portion of the electrode.

As can be seen from fig. 28 and 29: the intervening member 600 may be provided particularly in a region where the conductive elastic body 400 is disposed. As shown in the drawing, when a plurality of conductive elastic bodies 400 are used, it is preferable that an intervening member 600 is disposed between the conductive elastic bodies adjacent to each other. This is because the conductive elastic body 400 does not become an obstacle, and an intervening member can be more reliably disposed between the electrode and the electrode base.

The provision of the intervening component in the non-end region helps to improve the freedom of mounting of the electrode relative to the electrode base. That is, in the present invention, depending on the size or type of the electrode used, not only the intervention member can be provided at the end portion of the electrode, but also the intervention member can be provided in addition to or instead of this in the non-end portion region of the electrode.

(temporary electrode fixing mode)

In this embodiment, the electrode is temporarily fixed by an intervening member. That is, the electrode can be temporarily fixed with respect to the electrode base by the above-described mounting.

In the electrolytic cell, the operation is performed in a state where the electrolytic cell units are combined with each other with the separators interposed therebetween, and it is preferable that the electrodes are temporarily fixed to the electrolytic cell units before the electrolytic cell is assembled. This is because the electrolytic cell is assembled by vertically arranging the electrolytic cell units (see fig. 3). In addition, the electrolytic cell units may be disassembled for maintenance, and the combination of the electrolytic cell units may be released. In this case, if the electrode is temporarily fixed by the intervening member, the electrode can be removed from the electrode base portion, and the electrode base portion can be cleaned and replaced more easily.

The term "temporary fixation" as used herein means: when the electrode cell units are combined to form the electrode cell, the electrodes are fixed to prevent the electrodes from being deviated from the cells. Therefore, in the case of "temporary fixation", not all of the electrodes are joined to the electrode base portion, but only a part of the electrodes are joined to the electrode base portion. In such a temporary fixing method, it can be said that the electrode and the electrode base are locally joined.

The size of the intervening member for temporary fixation may not be too large. For example, taking a cross-sectional view of the insertion member 600 shown in fig. 21 as an example, the width W of the insertion member 600 is about 0.5mm to 10mm, and the height H of the insertion member 600 (particularly, the dimension H of a portion between the electrode and the electrode base) is about 0.5mm to 10 mm. In addition, in the case where there is a difference in width of the intervening members (i.e., in the case where the width dimension is not constant), the width dimension W refers to the largest maximum width dimension among them. Likewise, in the case where there is a difference in height of the intervening components (i.e., where the height dimension is not constant), the height dimension H refers to the largest maximum height dimension among them.

In the case where the intervening member is locally used with respect to the electrode region, the portion for attachment is also locally formed, so that the state of attachment of the electrode to the electrode base portion is easily released. Since it is easy to locally provide a thin plate-like member or a linear member as an intervening member to the electrode region, the state of attachment of the electrode to the electrode base is easily released. For example only, when spot welding is performed through an intervening member, a joint portion between an electrode and an electrode base portion becomes a "weld spot", and as part of maintenance, for example, when replacing the electrode, the electrode is easily removed from the electrode base portion.

(zero polar distance type special mode)

This embodiment is a specific embodiment of the zero-pitch type electrolytic cell. Since the zero-pitch system can bring the anode, the ion exchange membrane, and the cathode into close contact with each other as described above, the effect of "use of intervening members" is easily exhibited. As described above, if one of the anode and the cathode is flexible relative to the other, the anode, the ion exchange membrane, and the cathode can be better adhered to each other, but this also easily causes damage to the ion exchange membrane. In the electrode structure relating to the "use of an intervening member", by using the "intervening member" as the electrode mounting member even under such a close contact condition, the influence of such an electrode mounting member on the ion exchange membrane can be minimized, and damage to the ion exchange membrane can be suppressed. That is, in this aspect, one of the anode and the cathode is flexible so as to face the other electrode, and an intervening member is provided to the one electrode.

From the same viewpoint, even under conditions where the conductive elastic body is provided in the electrolytic cell and the ion exchange membrane is easily damaged, by using the "intervening member" as the electrode mounting member, the influence of the electrode mounting member on the ion exchange membrane can be reduced and damage to the ion exchange membrane can be suppressed.

[ electrolytic cell Unit of the present invention ]

In the present invention, an electrolyzer unit is also provided. The electrolytic cell unit of the present invention is a unit for constituting the electrolytic cell described above. Therefore, the cell is not limited to the cells combined with each other to constitute the electrolytic cell, and includes cells in a state before combination and cells in a state once combined and released from combination.

The electrolytic cell unit of the present invention has the above-described electrode structure because it is a unit constituting the electrolytic cell. That is, (I) at least one of the anode and the cathode is bent such that an end portion thereof is meandering in a cross-sectional view; (II) at least one of the anode and the cathode has an end-approaching member disposed in proximity to the end thereof; and/or (III) at least one of the anode and the cathode is attached to the electrode base via an intervening member interposed between the electrode and the electrode base on which the electrode is provided. As for other matters such as more detailed matters, more specific aspects and the like of the electrolytic cell unit of the present invention, the explanation has been directly or indirectly made in the above-mentioned "basic structure of electrolytic cell" and "feature of the present invention", and therefore, the explanation is omitted to avoid redundancy.

In addition, "electrode base" used in the present specification will be additionally described. As can be seen from the above description: in the case where the electrolytic cell is of the zero-pitch (particularly, strictly zero-pitch) type, the electrode base portion corresponds to a back plate or a support plate for pressing the conductive elastic body. Furthermore, based on the knowledge of the person skilled in the art, the electrode base corresponds to a base electrode which is opposite to the flexible electrode in the electrolytic cell, for example to a base cathode when the flexible electrode is a flexible cathode. In addition, if the electrode base is considered from the viewpoint of function and structure, the electrode base is preferably a porous plate material to be a current collecting plate.

Although the embodiments of the present invention have been described above, only typical examples within the scope of application of the present invention are shown. Therefore, it is easily understood to those skilled in the art that: the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope not changing the gist of the present invention.

For example, in the above (I), the "electrode end portion bent in a meandering manner" is described, but the form may be various forms. In addition, such a configuration may be considered as long as the influence of the electrode edge on the separator can be reduced, even if the electrode is not bent strictly in a meandering shape. For example, the electrode end may be bent to have only one bent portion in a cross-sectional view.

Fig. 30 to 43 exemplify the shapes of the electrode ends of various types of electrodes for electrolysis. Fig. 30 shows various exemplary forms in which the lower end portion is bent in a pointed shape in a cross-sectional view. Fig. 31 shows various exemplary forms in which the bent portion of the electrode end portion is bent in the shape of "コ" in a cross-sectional view. Fig. 32 shows various exemplary forms in which the bent portion of the electrode end portion is bent in an arc shape in a cross-sectional view. Fig. 33 shows a plurality of exemplary forms having a bend of the electrode end portion of substantially 90 ° (the bend having the illustrated angle α of substantially 90 ° (the same applies to the following drawings)). Fig. 34 shows a plurality of exemplary forms having a bend of the electrode end portion smaller than 90 ° (the bend with the angle α shown in the drawing is smaller than 90 ° (the same applies to the following drawings)). Fig. 35 shows a plurality of exemplary forms in which the electrode end portion is bent and bent from the bent portion to the edge. Fig. 36 shows various exemplary forms in which the electrode end portion is bent in a coil shape. Fig. 37 shows a mode in which the electrode end portion is bent so that the bent portion has an arc shape or a curved shape in a cross-sectional view, and an exemplary mode in which the electrode end portion has a plurality of kinds of deformation in the direction of the bending. Fig. 38 shows various exemplary forms of the electrode end portion including a bent portion, particularly a bent portion that is bent at approximately 90 ° in an arc shape or a curved shape in a cross-sectional view. Fig. 39 shows various exemplary forms of the electrode end portion including a bent portion, particularly a bent portion which is bent or not bent and is less than 90 ° in a cross-sectional view. Fig. 40 shows an exemplary form in which the electrode tip is bent so that the bent portion is shaped like "コ" in a cross-sectional view, and has a plurality of deformations in the direction of the bending. Fig. 41 shows various exemplary forms of the electrode end portion including a bent portion in the shape of "コ" in a cross-sectional view and including a bent portion bent at substantially 90 °. Fig. 42 shows various exemplary forms including a bent portion of substantially 90 ° and the bent portion increasing outward. Fig. 43 shows various exemplary forms of random bending with a point bent into a pointed shape.

In the above-mentioned (II), the end portion approaching member may be referred to as an "abutment member", "intervening member", or "close contact member" of the electrode end portion in consideration of its function, form, and the like. In addition, although the "electrode end portion provided with the end portion approaching member" is described above, the form may be various forms. Even if the end portion approaching member is not strictly provided at the electrode end portion, such a configuration can be considered as long as the influence of the electrode edge on the separator can be reduced.

Fig. 44 to 46 exemplify various arrangements of end proximity members that can be used for the electrode structure. Fig. 44 shows various exemplary forms in which the electrode tip is bent in a pointed shape in a cross-sectional view and the tip access member 500 is provided at the electrode tip or edge. Fig. 45 shows various exemplary forms in which the electrode tip is bent at various angles and the tip access member 500 is provided so as to surround the edge. Fig. 46 illustrates various exemplary configurations of electrode end bends and providing an end access feature 500 having a cross-sectional shape complementary to at least a portion of the inner contour of the bend.

In addition, although the embodiment of sealing the edges of the electrodes is described in connection with (II), the present invention is not limited thereto. For example, when a part of the mesh opening electrode is broken or partially damaged, the electrode portion may be sharpened (for example, "barbs" of strands may be generated at the broken or damaged portion). Accordingly, an edge sealing member may be provided at the fracture or defect site to reduce or avoid exposure of such a sharpened portion.

In the above-described (III), the intervening member is in the form of a thin plate or a wire, but the present invention is not limited thereto. The shape of the intervening member may be any shape as long as it is positioned between the electrode and the electrode base and contributes to the joining thereof.

In the present invention, at least two of the above-mentioned (I) to (III) may at least partially overlap each other. For example, the end portion approaching member may constitute the intervening member, or the intervening member may constitute the end portion approaching member.

Finally, the present invention can have the following modes.

Mode 1: an electrode for electrolysis used in an electrolytic cell, wherein at least one of an anode and a cathodeThe end portion is bent in a meandering manner in a cross-sectional view.

Mode 2: the electrolysis electrode according to mode 1, wherein the end portion has at least two bent portions in a cross-sectional view.

Mode 3: the electrolysis electrode according to aspect 1 or 2, wherein the bent portion of the end portion has a curved cross-sectional shape.

Mode 4: an electrolysis electrode according to any one of aspects 1 to 3, wherein a thin plate-like member or a linear member is provided so as to be sandwiched between the bent end portions.

Mode 5: an electrolysis electrode according to any one of aspects 1 to 4, wherein an end edge of the electrode is located more inward than an outermost edge of the bent end.

Mode 6: an electrolysis electrode according to mode 5, wherein the end portion has a first bent portion and a second bent portion due to the bending in a cross-sectional view,

the end edge is located substantially midway between the first bent portion and the second bent portion in the direction of the electrode face.

Mode 7: an electrolysis electrode according to any one of embodiments 1 to 6, wherein at least one of the electrodes has a conductive porous base material.

Mode 8: an electrolysis electrode according to any one of embodiments 1 to 7, wherein one of the anode and the cathode is relatively flexible with respect to the other of the anode and the cathode, and the one of the electrodes is bent.

Mode 9: an electrolytic cell comprising at least the electrode for electrolysis of any one of modes 1 to 8 and a separator.

Mode 10: the electrolytic cell according to mode 9, wherein the end portion of the electrolysis electrode is bent on a side opposite to the side on which the separator is located.

Mode 11: the electrolytic cell according to mode 9 or 10, wherein the end portion is bent so as not to straddle the electrode base portion on which the electrode is provided.

Mode 12: the electrolytic cell according to any one of aspects 9 to 11, wherein the conductive elastic body is provided on a back surface side of the one of the electrodes so that the one of the electrodes is pressed against the other of the electrodes by the conductive elastic body.

Mode 13: the electrolytic cell according to any one of modes 9 to 12, wherein the diaphragm is an ion exchange membrane.

Mode 14: the electrolytic cell according to any one of modes 9 to 13, which is a zero-pole-pitch common salt electrolytic cell.

Mode 15: an electrode structure for an electrolytic cell, wherein at least one of an anode and a cathode has an end-approaching member disposed in proximity to an end thereof.

Mode 16: the electrode structure according to mode 15, wherein the end proximity member is in direct contact with the end of the electrode.

Mode 17: the electrode structure according to mode 15 or 16, wherein the end-approaching member is thin plate-shaped or linear.

Mode 18: the electrode structure according to any one of modes 15 to 17, wherein the end portion of the electrode is bent, and the end portion approach member is sandwiched between the bent end portions.

Mode 19: the electrode structure according to any one of modes 15 to 18, wherein the end proximity member surrounds at least a part of an outer peripheral edge of the electrode.

Mode 20: the electrode structure according to any one of modes 15 to 19, wherein the end approaching member is provided between the electrode and an electrode base portion on which the electrode is provided.

Mode 21: the electrode structure according to any one of modes 15 to 19, wherein the end portion approaching member is provided so as to cover the end portion of the electrode.

Mode 22: the electrode structure according to any one of modes 15 to 21, wherein the electrode and an electrode base portion provided with the electrode are joined to each other via the end proximity member.

Mode 23: the electrode structure according to any one of modes 15 to 22, wherein the electrode and an electrode base portion on which the electrode is provided are welded to each other via the end proximity member.

Mode 24: the electrode structure according to any one of modes 15 to 22, wherein the end proximity member includes at least a resin material.

Mode 25: the electrode structure according to any one of modes 15 to 23, wherein the end proximity member includes at least a metal material.

Mode 26: the electrode structure according to any one of modes 15 to 25, wherein the at least one electrode has a conductive porous base material.

Mode 27: the electrode structure according to any one of modes 15 to 26, wherein one of the anode and the cathode has flexibility to be opposed to the other of the anode and the cathode, and the end approaching member is provided on the one of the electrodes.

Mode 28: according to the electrode structure of aspect 27, the conductive elastic body is provided on the back surface side of the one electrode so that the one electrode is pressed toward the other electrode by the conductive elastic body.

Mode 29: the electrode structure according to any one of modes 15 to 28, wherein a separator, which is an ion exchange membrane, is provided between the anode and the cathode.

Mode 30: the electrode structure according to any one of modes 15 to 29, which is an electrode structure for a zero-pole-pitch-type salt electrolyzer.

Mode 31: an electrolytic cell comprising at least an anode, a cathode and a separator therebetween,

at least one of the anode and the cathode is attached to an electrode base portion in which the electrode is provided, via an intervening member interposed between the electrode and the electrode base portion.

Mode 32: the electrolytic cell according to mode 31, wherein the intervening member is in the form of a thin plate or a wire.

Mode 33: the electrolytic cell according to mode 31 or 32, wherein the electrode and the electrode base are joined to each other through the intervening member.

Mode 34: the electrolytic cell according to any one of modes 31 to 33, wherein the electrode and the electrode base are welded to each other through the intervening member.

Mode 35: the electrolytic cell according to any one of modes 31 to 34, wherein the intervening member is disposed further to the separator than the electrode.

Mode 36: the electrolytic cell according to any one of modes 31 to 35, wherein the intervening member is provided at least in an end region of the electrode.

Mode 37: according to the electrolytic cell of mode 31 or 36, the electrode end is bent in such a manner that: positioning an end edge of the electrode on an upper surface of a thin plate-like member provided as the intervening member on the electrode base; the joint portion is present in a region further inward than the end edge.

Mode 38: the electrolytic cell according to any one of modes 31 to 35, wherein the intervening member is provided in a non-end region other than an end region of the electrode.

Mode 39: the electrolytic cell according to any one of modes 31 to 38, wherein the electrode is temporarily fixed to the electrode base by the mounting.

Mode 40: the electrolytic cell according to any one of modes 31 to 39, wherein the at least one electrode has a conductive porous base material.

Mode 41: the electrolytic cell according to any one of modes 31 to 40, wherein one of the anode and the cathode has flexibility to be opposed to the other of the anode and the cathode, and the intervening member is provided on the one of the electrodes.

Mode 42: according to the electrolytic cell of the aspect 41, the conductive elastic body is provided on the back surface side of the one electrode so that the one electrode is pressed toward the other electrode by the conductive elastic body.

Mode 43: the electrolytic cell according to any one of modes 31 to 42, wherein the diaphragm is an ion exchange membrane.

Mode 44: the electrolytic cell according to any one of modes 31 to 43, wherein the electrolytic cell is a zero-pole-pitch common salt electrolytic cell.

Mode 45: an electrolytic cell unit used in the electrolytic cell of any one of the constitution modes 31 to 44.

Industrial applicability

The electrode structure according to the present invention can be used for various electrolytic cells for electrolysis. Although not limited thereto, the present invention is applicable to, for example, an electrolytic cell used in the alkali industry, and is particularly suitable for an electrolytic cell in which there is a risk of damage to a separator by an electrode.

Claims

1. An electrode structure used in an electrolytic cell and having any one of the following (I) to (III),

(II) at least one of the anode and the cathode has an end-approaching member disposed in proximity to the end thereof;

2. The electrode structure according to claim 1,

in the electrolytic cell, an edge of the at least one electrode is not in contact with the separator between the anode and the cathode.

3. The electrode structure according to claim 1 or 2,

the end part has at least two bending parts under the cross-sectional view.

4. The electrode structure according to claim 1 or 2,

the bent portion of the end portion has a curved sectional shape.

5. The electrode structure according to claim 1 or 2,

a thin plate-like member or a linear member is provided so as to be sandwiched between the bent end portions.

6. The electrode structure according to claim 1 or 2,

the edge of the electrode is located more inward than the outermost edge of the end of the bend.

7. The electrode structure according to claim 6,

the end portion has a first bent portion and a second bent portion due to the bending in a cross-sectional view,

the edge is located substantially midway between the first folded portion and the second folded portion in the direction of the electrode face.

8. The electrode structure according to claim 1 or 2,

the end proximity component is in direct contact with the end of the electrode.

9. The electrode structure according to claim 1 or 2,

the end approaching member is thin plate-like or linear.

10. The electrode structure according to claim 1 or 2,

the end portion of the electrode is bent, and the end portion approach member is held at the bent end portion.

11. The electrode structure according to claim 1 or 2,

the end proximity component surrounds at least a portion of an edge of the electrode.

12. The electrode structure according to claim 1 or 2,

the end portion approaching member is provided between the electrode and an electrode base portion where the electrode is provided.

13. The electrode structure according to claim 1 or 2,

the end portion of the electrode is provided with the end portion access member in a covering manner.

14. The electrode structure according to claim 1 or 2,

the electrode and an electrode base portion provided with the electrode are joined to each other via the end portion approaching member.

15. The electrode structure according to claim 1 or 2,

the electrode and an electrode base portion where the electrode is provided are welded to each other via the end proximity member.

16. The electrode structure according to claim 1 or 2,

the end proximity part contains at least a resin material.

17. The electrode structure according to claim 1 or 2,

the end proximity member includes at least a metal material.

18. The electrode structure according to claim 1 or 2,

the intervening member is in the shape of a thin plate or a wire.

19. The electrode structure according to claim 1 or 2,

the electrode and the electrode base are joined to each other through the intervening member.

20. The electrode structure according to claim 1 or 2,

the electrode and the electrode base are welded to each other through the intervening member.

21. The electrode structure according to claim 2,

the intervening member is disposed on a position side farther than the electrode with respect to the diaphragm.

22. The electrode structure according to claim 1 or 2,

the intervening component is disposed at least in an end region of the electrode.

23. The electrode structure according to claim 1 or 2,

the intervening member is disposed in a non-end region other than an end region of the electrode.

24. The electrode structure according to claim 1 or 2,

temporarily fixing the electrode relative to the electrode base by the mounting.

25. The electrode structure according to claim 1 or 2,

the at least one electrode has a conductive porous substrate.

26. The electrode structure according to claim 1 or 2,

one of the anode and the cathode has flexibility so as to be opposed to the other of the anode and the cathode, the one of the electrodes is bent, and the end approaching member is provided on the one of the electrodes or the intervening member is provided on the one of the electrodes.

27. The electrode structure of claim 26,

the conductive elastic body is provided on the back surface side of the one electrode so that the one electrode is pressed toward the other electrode by the conductive elastic body.

28. The electrode structure according to claim 1,

a separator, which is an ion exchange membrane, is disposed between the anode and the cathode.

29. The electrode structure of claim 28,

the end portion of the at least one electrode is bent on a side opposite to the side where the separator is located.

30. The electrode structure of claim 29,

the end portion is bent so as not to straddle the electrode base portion on which the electrode is provided.

31. The electrode structure according to claim 1 or 2,

the electrode structure is used for a zero-polar distance type salt electrolysis bath.