JP7122181B2 - Electrode structure, electrolytic cell and electrolytic bath - Google Patents

Description

The present invention relates to electrode structures, electrolytic cells and electrolytic baths.

Alkali metal salt electrolysis is the process of electrolyzing an aqueous alkali metal chloride solution such as salt water (hereinafter also simply referred to as "electrolysis") to produce high-concentration alkali metal hydroxide, hydrogen, chlorine, etc. The method. Electrolysis using a mercury method or a diaphragm method can be mentioned as a method for this, but in recent years, an ion-exchange membrane method, which has good power efficiency, is mainly used.

In the ion-exchange membrane method, electrolysis is performed using an electrolytic cell in which a large number of electrolytic cells each having an anode and a cathode (hereinafter collectively referred to as "electrodes") are arranged via ion-exchange membranes. The electrolytic cell has a structure in which a cathode chamber with a cathode and an anode chamber with an anode are arranged back to back with a partition wall (back plate) interposed therebetween. In the electrolysis cell, an aqueous alkali metal chloride solution is supplied to the anode chamber and an alkali metal hydroxide is supplied to the cathode chamber, and electrolysis is performed to generate chlorine gas in the anode chamber and alkali metal hydroxide in the cathode chamber. produce hydrogen gas.

Further, in recent years, in order to further improve the power consumption rate, zero-gap electrolysis, in which electrolysis is performed by bringing an ion exchange membrane and a cathode into contact, has become mainstream. For example, Patent Literature 1 discloses the structure of a zero-gap electrolytic cell. Normally, a rib and an anode are arranged in the anode chamber of the zero-gap electrolytic cell, and a rib, a current collector (conductive plate), an elastic body (mattress) and a cathode are arranged in the cathode chamber. In the cathode chamber, a current collecting plate, an elastic body, and a cathode are arranged in this order. By pressing the cathode with a cushioning mattress, the cathode can be brought into contact with the ion-exchange membrane during electrolysis. Hereinafter, a structure including a current collector plate, an elastic body and an electrode will be simply referred to as an "electrode structure".

Patent Document 2 discloses a method of using a Teflon (registered trademark) pin and a method of welding as conventionally known methods of fixing a cathode. As a welding method, there is a method of spot-welding the peripheral edge of the cathode onto the sealing surface of the cathode chamber frame using a nickel tape. Specifically, the cathode is fixed by placing the cathode on the sealing surface of the cathode chamber frame, placing a nickel tape thereon, and spot welding the tape.

Japanese Patent No. 4453973 JP 2010-111947 A

According to the techniques described in Patent Documents 1 and 2, in the method of fixing the cathode by spot welding on the sealing surface using a nickel tape, corrosion of the sealing surface of the cathode chamber frame and sealing during cathode renewal Problems such as thinning of the surface and poor work efficiency occur.

In addition, in the electrolytic cell, a gasket is attached to the sealing surface corresponding to the outer periphery of the electrolytic cell in order to prevent the contents from leaking. In this case, as shown in FIG. 6, since the cathode 104 and the nickel tape 106 are affixed and fixed on the sealing surface 102 of the electrolytic cell 100, unevenness exists, and the electrolyte solution tends to accumulate in this portion. , the sealing surface 102 may be corroded (crevice corrosion) depending on the conditions. Moreover, when the gasket deteriorates as the electrolysis is performed, the gasket is replaced in order to ensure the sealing performance of the gasket. In the electrolytic cell shown in FIG. 6, when the gasket is replaced, the nickel tape 106 is peeled off together with the gasket 108, and the cathode 104 may be torn. This leads to damage inside the electrolysis cell.

Furthermore, when the electrodes deteriorate as the electrolysis is performed, the electrodes are replaced in order to eliminate the deterioration of the electrolysis performance. Here, when replacing the cathode 104, the old cathode 104 is peeled off, the sealing surface 102 of the frame 101 of the cathode chamber 110 is washed, and a new cathode is spotted on the sealing surface 102 using a nickel tape 106. Fix by welding. In order to fix by welding, it is necessary to remove oxides on the surface layer of the sealing surface 102 . In order to remove the oxide, the surface layer of the seal surface 102 needs to be scraped, and the thickness of the plate material of the seal surface 102 is reduced. If such an operation is repeated, there is a possibility that the reduction in sealing performance due to the reduction in wall thickness will become apparent. As described above, the conventional method has the problem that it takes a lot of time and effort to replace the cathode.

Here, in consideration of this problem, it is conceivable to construct a structure in which at least a part of the peripheral edge of the cathode straddles the edge of the current collector plate and is folded on the side opposite to the cathode of the current collector plate. . However, simply folding the peripheral edge of the cathode to the opposite side of the current collector plate is likely to cause wire breakage in the mattress due to welding and replacement of the mattress, resulting in damage to the ion exchange membrane, etc., inside the electrolytic cell. Damage may occur.

As described above, the prior art still has room for improvement from the viewpoint of preventing damage inside the electrolytic cell due to replacement of members such as electrodes and from the viewpoint of preventing crevice corrosion on the seal surface. The present invention has been made to solve the above problems, and an object of the present invention is to provide an electrode structure capable of reducing corrosion and damage inside an electrolytic cell, and an electrolytic cell and an electrolytic bath using the same.

The present inventors have made intensive studies in order to solve the above problems. As a result, the inventors have found that the above problems can be solved by forming the edges of the electrodes and the elastic body into predetermined shapes, and have completed the present invention.

That is, the present invention is as follows.
[1]
an electrode;
a current collector plate having a first surface facing the electrode and a second surface opposite to the first surface;
an elastic body positioned between the electrode and the first surface of the current collector plate and having electrical conductivity;
with
An electrode structure, wherein at least part of the peripheral edge of the electrode and at least part of the peripheral edge of the elastic body extend across the edge of the current collector plate so as to be positioned on the second surface.
[2]
The electrode structure according to [1], wherein the entire peripheral edge portion of the electrode and the entire peripheral edge portion of the elastic body extend across the edge of the current collector plate so as to be positioned on the second surface.
[3]
The electrode structure according to [1] or [2], wherein the length of the portion of the electrode and the elastic body located on the second surface of the current collector plate is 3 mm or more and 20 mm or less.
[4]
a cathode chamber;
a partition facing the cathode chamber;
an anode chamber facing the partition wall and located on the side opposite to the cathode chamber;
with
An electrolytic cell, wherein at least one of the cathode chamber and the anode chamber includes the electrode structure according to any one of [1] to [3].
[5]
The electrolytic cell according to [4];
an ion exchange membrane facing the electrolytic cell;
an electrolytic cell.

ADVANTAGE OF THE INVENTION According to this invention, the electrode structure which can reduce corrosion and damage in an electrolysis cell, an electrolysis cell using the same, and an electrolysis tank can be provided.

FIG. 1 is a front view schematically illustrating an electrolytic cell according to one embodiment of the invention. FIG. 2 is a front view illustrating an electrolytic cell according to one embodiment of the invention. 3 is a diagram showing a cross-sectional configuration of the electrolytic cell shown in FIG. 2. FIG. 4 is a cross-sectional view showing an enlarged part of the electrolytic cell shown in FIG. 3. FIG. FIG. 5 is a diagram illustrating a cross-sectional configuration of an electrolytic cell according to another embodiment of the invention. FIG. 6 is a diagram showing a cross-sectional structure of a conventional electrolytic cell.

EMBODIMENT OF THE INVENTION Hereinafter, the form (only henceforth "this embodiment") for implementing this invention is demonstrated in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the gist thereof.
In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and overlapping descriptions are omitted. In addition, unless otherwise specified, the positional relationships in the drawings, such as top, bottom, left, and right, are based on the positional relationships shown in the drawings, and the dimensional ratios in the drawings are not limited to the ratios shown in the drawings. However, the drawings merely show an example of the present embodiment, and the present embodiment should not be construed as being limited thereto.

The electrode structure of this embodiment includes an electrode, a current collector plate having a first surface facing the electrode and a second surface opposite to the first surface, and the second surface between the electrode and the current collector plate. an elastic body positioned between the first surface and having conductivity, wherein at least part of the peripheral edge of the electrode and at least part of the peripheral edge of the elastic body are aligned with the edge of the current collector plate straddling the part and extending so as to be positioned on the second surface. As described above, in the electrode structure of the present embodiment, both the elastic body and the electrode are folded toward the second surface side of the collector plate. It is possible to fix these to the current collector plate without any need to fix them, and as a result, it is possible to prevent wire breakage of the elastic body that may occur during welding. In particular, since welding of the electrodes is unnecessary, it is possible to effectively prevent crevice corrosion of the sealing surface caused by accumulation of the electrolyte in the vicinity of the welded portion. Therefore, the electrode structure of this embodiment can reduce corrosion and damage inside the electrolytic cell.

Moreover, the electrode structure of this embodiment is applied to the electrolytic cell of this embodiment. That is, the electrolytic cell of the present embodiment includes a cathode chamber, a partition facing the cathode chamber, and an anode chamber facing the partition and located on the opposite side of the cathode chamber. At least one of the anode chambers includes the electrode structure of this embodiment. Because of this configuration, the electrolytic cell of the present embodiment can reduce internal corrosion and damage.
Furthermore, the electrolytic cell of the present embodiment includes the electrolytic cell of the present embodiment and an ion exchange membrane facing the electrolytic cell. Because of this configuration, the electrolytic cell of the present embodiment can reduce internal corrosion and damage.

Hereinafter, the configuration of the electrode structure of the present embodiment will be described in detail based on the relationship with the configuration of the electrolytic cell and the electrolytic bath having the electrode structure.

FIG. 1 is a front view schematically showing an electrolytic cell according to one aspect of the present embodiment. As shown in FIG. 1, the electrolytic cell 1 is composed of a plurality of electrolytic cells 3 connected in series by a press 7 via ion exchange membranes 5 (see FIG. 4). It is an electrolytic cell. In the electrolytic cell 1, one of the electrolytic cells 3 located at both ends is connected to the anode terminal 9, and the other is connected to the cathode terminal 11. As shown in FIG.

The electrolysis in the electrolytic cell 1 is separated by the ion exchange membrane 5 between the anode chamber 22 (see FIG. 3) of the electrolysis cell 3 described later and the cathode chamber 32 (see FIG. 3) of the adjacent electrolysis cell 3. is done in For example, sodium ions will migrate from the anode compartment 22 of the electrolysis cell 3 through the ion exchange membrane 5 to the cathode compartment 32 of the adjacent electrolysis cell 3, and the current during electrolysis is connected in series. It will flow along the direction of the electrolytic cell 3 .

The ion exchange membrane 5 is not particularly limited, and known membranes can be used. For example, when chlorine and alkali are produced by electrolysis of alkali chloride or the like, fluorine-containing ion exchange membranes are preferable from the viewpoint of excellent heat resistance and chemical resistance. Examples of the fluorine-containing ion exchange membrane include those having a function of selectively permeating cations generated during electrolysis and containing a fluorine-containing polymer having ion exchange groups. The fluorine-containing polymer having an ion-exchange group as used herein means a fluorine-containing polymer having an ion-exchange group or an ion-exchange group precursor capable of becoming an ion-exchange group by hydrolysis. For example, a polymer which consists of a main chain of a fluorinated hydrocarbon, has a functional group convertible to an ion-exchange group by hydrolysis or the like as a pendant side chain, and is melt-processable.

Next, the electrolytic cell 3 will be described in detail. FIG. 2 is a front view showing an electrolytic cell according to one aspect of the present embodiment, viewed from the cathode side. 3 is a diagram showing a cross-sectional configuration of the electrolytic cell shown in FIG. 2. FIG. The ribs (supports) 42 are not shown in FIG. 4 is a cross-sectional view showing an enlarged part of the electrolytic cell shown in FIG. 3. FIG. As shown in each figure, the electrolytic cell 3 includes an anode section 20, a cathode section 30, and a partition wall 50 separating the anode section 20 and the cathode section 30 (anode chamber 22 and cathode chamber 32). The anode section 20 and the cathode section 30 are electrically connected. The electrolytic cell 3 is a zero-gap electrolytic cell.

The anode section 20 has an anode chamber 22 . Anode chamber 22 is defined by frame 24 . A gasket 26 is provided on the upper surface of the frame 24 . An anode 28 is provided in the anode chamber 22 . Anode 28 is provided on one side surface of electrolytic cell 3 . The anode 28 is provided on one side of the electrolytic cell 3, and can be a metal electrode such as a so-called DSA, which is a titanium base coated with an oxide containing ruthenium and iridium.

The cathode section 30 has a cathode chamber 32 . The cathode chamber 32 is defined by a frame 34 . A gasket 36 is provided on the upper surface (seal surface) 34 a of the frame 34 . The cathode chamber 32 is provided with a cathode 38 , a collector plate 40 , ribs (supports) 42 and a mattress (elastic body) 44 .

A cathode 38 is provided on the other side of the electrolytic cell 3 . As the cathode 38 that can be used in the zero-gap electrolytic cell, a cathode with a small wire diameter and a small number of meshes is preferred because of its high flexibility. Various known materials can be used for such a cathode substrate. The cathode 38 may have, for example, a wire diameter of 0.1 mm to 0.5 mm and an opening of about 20 mesh to 80 mesh.

The cathode coating is preferably a thin noble metal or noble metal oxide coating, and may contain rare earth elements in addition to the noble metal. By making the coating thinner, it tends to be possible to secure sufficient flexibility of the cathode and prevent local damage to the ion-exchange membrane 5 . Highly active noble metal or noble metal oxide coatings are preferred for thin coatings. Therefore, the thickness of the coating layer is preferably 0.5 μm to 50 μm, more preferably 1 μm to 10 μm.

As shown in FIG. 4, the current collector plate 40 is arranged along the cathode 38 . The current collecting plate 40 is for enhancing the current collecting effect of the cathode 38 . The current collector plate 40 has a pair of front surfaces (first surfaces) 40a and rear surfaces (second surfaces) 40b that face each other. The current collector plate 40 is arranged so that the surface 40 a faces the cathode 38 .

Moreover, the current collector plate 40 conducts electricity to the mattress 44 and the cathode 38 and supports the load pressed from the mattress 44 and the cathode 38 . Furthermore, the current collector plate 40 has a function of allowing hydrogen gas generated from the cathode 38 to pass through to the partition wall 50 side. Therefore, the current collector plate 40 is preferably an expanded metal plate or a punched perforated plate. The aperture ratio of the holes provided in the current collector plate 40 is preferably 40% or more in order to extract the hydrogen gas generated from the cathode 38 to the partition wall 50 side. Nickel, a nickel alloy, stainless steel, iron, or the like can be used as the material of the current collector plate 40 from the viewpoint of corrosion resistance, but nickel is preferable from the viewpoint of conductivity. As the collector plate 40, the cathode used in the finite gap electrolysis cell can be used as it is. Further, as the collector plate 40, a cathode for a finite gap or the like, in which expanded metal is coated with nickel oxide by plasma spraying, can be used.

The rib 42 is located inside the cathode chamber 32 and is arranged between the partition wall 50 and the back surface 40 b side of the current collector plate 40 . The ribs 42 support and fix the collector plate 40 . The ribs 42 are welded and fixed to the partition wall 50 and the collector plate 40 respectively.

A mattress 44 is arranged between the cathode 38 and the surface 40a side of the collector plate 40 . In the zero-gap electrolytic cell 3, the rigidity of the anode 28 is ensured so that the ion exchange membrane 5 is not easily deformed even when pressed. On the other hand, the electrolysis cell 3 has a flexible structure on the side of the cathode 38 to absorb unevenness due to manufacturing tolerances of the electrolysis cell 3 and electrode deformation, thereby maintaining a zero gap. A mattress 44 is used to provide a flexible structure on the cathode 38 side.

The mattress 44 has a function of transmitting electricity to the cathode 38 and a function of passing hydrogen gas generated from the cathode 38 to the current collector plate 40 side. The mattress 44 applies a suitable and uniform pressure to the cathode 38 in contact with the ion exchange membrane 5 without damaging the ion exchange membrane 5 . Thereby, the cathode 38 is in close contact with the ion exchange membrane 5 .

As the mattress 44, a conventionally known one can be used. A wire diameter of 0.05 mm or more and 0.25 mm or less is preferably used as the wire diameter of the mattress 44 . When the wire diameter of the mattress 44 is 0.05 mm or more, the mattress is more prevented from being crushed. Since there is a tendency to prevent the pressing pressure from increasing excessively, the performance of the ion exchange membrane 5 is less likely to be affected. More preferably, the mattress has a wire diameter of 0.08 mm or more and 0.20 mm or less. Nickel is used as the material of the mattress 44 from the viewpoint of conductivity and alkali resistance. For example, a braided nickel wire having a wire diameter of about 0.1 mm may be corrugated.

The partition wall 50 is arranged between the anode chamber 22 and the cathode chamber 32 (the anode section 20 and the cathode section 30). The partition wall 50 is sometimes called a separator, and separates the anode chamber 22 and the cathode chamber 32 from each other. As the partition wall 50, a known separator for electrolysis can be used, and examples thereof include a partition wall in which a plate made of nickel is welded to the cathode side and titanium is welded to the anode side.

Next, the mounting structure and mounting method of the cathode 38 will be described in detail. As shown in FIG. 4, the cathode 38 has its upper end portion (part of the peripheral portion) folded toward the rear surface 40b of the current collector plate 40 . Specifically, the upper end portion of the cathode 38 is inserted into the gap S formed between the frame 34 and the edge portion 40c of the current collector plate 40, straddling the edge portion 40c of the current collector plate 40 to the rear surface 40b. folded to the side. Furthermore, in the present embodiment, not only the cathode 38 but also the mattress 44 has its upper end portion (part of the peripheral portion) folded toward the back surface 40b of the current collector plate 40. As shown in FIG. That is, the upper end of the mattress 44 is also inserted into the gap S formed between the frame 34 and the edge 40c of the current collector 40, straddles the edge 40c of the current collector 40, and is folded back toward the back surface 40b. be Conventionally, the mattress 44 was partially spot-welded and fixed to the current collector plate 40 from the viewpoint of preventing the mattress 44 from hanging down to the lower end of the electrolysis cell 3 during electrolysis and from the viewpoint of conductivity. , the upper end portion (part of the peripheral portion) of the mattress 44 is folded toward the back surface 40b of the current collector plate 40, that is, at least a portion of the peripheral portion of the mattress 44 is folded into the edge portion of the current collector plate 40. The above-mentioned spot welding becomes unnecessary by adopting a structure extending so as to straddle the back surface 40b. In other words, not only is the workability of member replacement improved, but it is possible to prevent the breakage of the mattress that may occur during mattress replacement, and as a result, damage to the inside of the electrolytic cell, such as damage to the ion exchange membrane, is effectively prevented. can be effectively prevented.

A gap S formed between the frame 34 and the edge 40c of the current collector plate 40 is preferably 3 mm or more and 10 mm or less. More preferably, it is 4 mm or more and 7 mm or less. When the gap S is 3 mm or more, it tends to be easier to insert the cathode 38 and the mattress 44 into the gap. Further, when the gap S is 10 mm or less, it is possible to effectively prevent the ion-exchange membrane 5 from falling into the gap due to contraction of the ion-exchange membrane 5, and as a result, damage to the ion-exchange membrane 5 can be prevented more effectively. There is a tendency.

In order to realize the structure described above, the cathode 38 is preferably cut larger than the current-carrying portion of the electrolytic cell 3 . Here, the dimension of the portion (the portion longer than the current-carrying portion) where the cathode 38 is folded into the back surface 40b of the current collector plate 40, that is, the portion of the cathode 38 and the mattress 44 located on the back surface 40b of the current collector plate 40 The dimension is referred to as the folded length L below. The folded length L is preferably 3 mm or more and 20 mm or less. It is more preferably 5 mm or more and 15 mm or less. When the folded length L is 20 mm or less, there is a tendency that the cathode 38 and the mattress 44 in the folded portion can be sufficiently fixed to the collector plate 40 . Further, when the folded length L is 3 mm or more, it tends to be difficult for the cathode 38 and the mattress 44 to come off the collector plate 40 . From the same viewpoint as above, the folded length L is more preferably 10 mm or more and 15 mm or less. In addition, the folding length L can be specifically specified as the shortest distance from the edge 40 c to the terminal end of the cathode 38 and the mattress 44 .

Although FIG. 4 shows the configurations of the upper portions of the cathode 38 and the mattress 44 , the lower ends of the cathode 38 and the mattress 44 may also be folded toward the rear surface 40 b of the collector plate 40 . That is, both ends (entire peripheries) of the cathode 38 and the mattress 44 may be folded toward the rear surface 40b of the collector plate 40 . In this way, the cathode 38 and the mattress 44 can be fixed to the current collector plate 40 by folding the respective upper ends of the cathode 38 and the mattress 44 into the back surface 40 b side of the current collector plate 40 . In addition, by folding the lower ends of the cathode 38 and the mattress 44 toward the rear surface 40b of the collector plate 40, the cathode 38 and the mattress 44 are more firmly fixed to the collector plate 40, and the hanging of the mattress 44 is effectively prevented. can be effectively prevented. More preferably, the cathode 38 and the mattress 44 can be more firmly fixed to the current collector plate 40 by folding all the outer peripheral edges of the cathode 38 and the mattress 44 toward the back surface 40b of the current collector plate 40 .

When attaching the cathode 38 and the mattress 44 to the collector plate 40, it is preferable to cut the corners of the cathode 38. As shown in FIG. By notching the corner, the cathode 38 can be inserted at the corner. Although it is possible to make a diagonal notch in the corner (a linear notch extending from the corner to the in-plane direction of the cathode) and insert it, if cut in this way, the cathode 38 will not fit here. It is preferable to notch the corners as described above, as they tend to tear easily as starting points.

As a jig for folding the cathode 38 and the mattress 44 into the back surface 40b side of the collector plate 40, various known jigs can be used. Specifically, each end of the cathode 38 and the mattress 44 is pushed into the electrolytic cell 3 along the edge of the current collector plate 40 with a spatula and a rotating roller, so that the cathode 38 and the mattress 44 are pushed into the back surface of the current collector plate 40 . It can be folded and fixed to the 40b side. From the viewpoint of workability, the jig for folding the cathode 38 and the mattress 44 is preferably a rotating roller. The thickness of the blade of the rotating roller is preferably 0.2 mm or more. When the thickness is 0.2 mm or more, sufficient rigidity is ensured, and it tends to be easier to insert the cathode 38 and the mattress 44 . Also, if the thickness is greater than the gap S between the current collector plate 40 and the frame 34 (seal surface 34a of the gasket 36), the rotating roller itself cannot be inserted, making it difficult to insert the cathode 38 and the mattress 44. More preferably, it ranges from 0.2 mm to 2 mm. The diameter of the rotating roller is not particularly limited, and a roller having a diameter of about 100 mm is usually easy to operate.

This embodiment is not limited to the above. For example, in addition to the above, the cathode 38 may be sandwiched between the gasket 36 and the collector plate 40 as shown in FIG. With such a configuration, when the electrolysis cells 3 are connected in series by the presser 7, even the tip of the gasket 36 that is not in contact with the sealing surface 34 can press the ion exchange membrane 5, and the gasket 36 It is possible to prevent caustic soda from entering between and the ion-exchange membrane 5 and suppress damage to the ion-exchange membrane 5 .

4 and 5 show a mode in which the cathode 38 and the mattress 44 extend without contacting the back surface 40b of the current collector 40. Even in this state, the cathode 38 and the mattress 44 are 40 , and from the viewpoint of stronger fixation, it is preferable that the cathode 38 and the mattress 44 extend so as to come into contact with the back surface 40 b of the current collector plate 40 .

Although the electrode structure (that is, cathode structure) in which the electrode is a cathode has been described above, the electrode in this embodiment may be an anode. That is, the electrode structure of this embodiment can also be applied to an anode chamber as an anode structure. In that case, various known members can be used as the anode chamber, and various known members can be applied as the anode.

The present embodiment will be described in more detail below based on examples. This embodiment is not limited only to these examples.

A zero-gap electrolytic cell having a width of 2400 mm and a height of 1289 mm was prepared as follows. A nickel plate having a size of 1149 mm×2347 mm and a thickness of 1.2 mm was prepared as a current collector, and a mattress (nickel knitted fabric) having a wire diameter of 0.15 mm was placed on the surface thereof. Then, a rotating roller with a diameter of 100 mm is used to apply the peripheral edge (all four sides) of the mattress onto the back surface of the current collector through the gap formed between the frame of the electrolytic cell and the edge of the current collector. It was bent into position, straddled over the edge of the current collector and pushed onto the back surface of the current collector with a spatula. The folding length at this time was 10 mm.
In addition, a cathode made of nickel fine mesh substrate coated with ruthenium oxide was placed on the mattress. A rotating roller with a diameter of 100 mm was used to bend the peripheral edge (all four sides) of the cathode so that it straddled the edge of the current collector through a gap and was positioned on the back surface of the current collector. That is, the peripheral edge of the cathode was folded toward the rear surface 40b of the current collector plate 40 and fixed. The folding length at this time was 10 mm.
This electrolytic cell is incorporated into an electrolytic bath, and as the anode, a titanium base material coated with an oxide containing ruthenium and iridium as components is used, and as the ion exchange membrane, ACIPLEX (registered trademark) F6801 is used as the anode. About 300 g/L of salt water was supplied as a liquid, and dilute caustic soda was supplied to the cathode chamber so that the caustic soda concentration was about 32% by weight near the discharge port. Electrolysis was performed for 4 days at a pressure of 40 kPa, a cathode chamber side gas pressure of 44 kPa, and a current density of 4 kA/m ² , and then the current density was increased to 6 kA/m ² for a total of 152 days of electrolysis. Further, electrolysis was performed by adding hydrochloric acid to the supplied salt water so that the pH of the salt water near the discharge of the anolyte was 2. The ion-exchange membrane taken out after electrolysis had no abnormality such as pinholes. Observation of the cathode seal surface after completion of electrolysis revealed no corrosion at all.

1 electrolytic cell,
22 anode chamber,
32 cathode chamber,
38 cathode,
40 current collector,
44a surface (first surface),
44b back surface (second surface),
44c edge,
42 ribs (supports),
44 mattress (elastic body)

Claims (5)

an electrode;
a current collector plate having a first surface facing the electrode and a second surface opposite to the first surface;
an elastic body positioned between the electrode and the first surface of the current collector plate and having electrical conductivity;
with
An electrode structure, wherein at least part of the peripheral edge of the electrode and at least part of the peripheral edge of the elastic body extend across the edge of the current collector plate so as to be positioned on the second surface. 2. The electrode structure according to claim 1, wherein the entire peripheral edge portion of the electrode and the entire peripheral edge portion of the elastic body extend across the edge of the current collector plate so as to be positioned on the second surface. 3. The electrode structure according to claim 1, wherein lengths of portions of said electrode and said elastic body located on said second surface of said current collector plate are 3 mm or more and 20 mm or less. a cathode chamber;
a partition facing the cathode chamber;
an anode chamber facing the partition wall and located on the side opposite to the cathode chamber;
with
An electrolytic cell, wherein at least one of the cathode compartment and the anode compartment comprises an electrode structure according to any one of claims 1-3. an electrolytic cell according to claim 4;
an ion exchange membrane facing the electrolytic cell;
an electrolytic cell.

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