JP6258444B2 - Electrochemical cell, oxygen reduction device using the cell, refrigerator and electrochemical device using the oxygen reduction device - Google Patents

Description

  Embodiments of the present invention relate to an electrochemical cell used for, for example, an electrolysis cell that performs electrolysis, an oxygen reduction device using the cell, a refrigerator using the oxygen reduction device, and an electrochemical device.

  Conventionally, a conductive porous material processed by expanding, etching, or punching has been used as an electrode or an electrode base material used in an electrolytic cell, a battery, or the like.

 For example, a catalyst-coated titanium mesh in which a catalyst is coated on a titanium plate having a mesh structure is used as an anode substrate of an electrochemical cell used for producing sodium hydroxide. The mesh-structured titanium plate not only serves as a catalyst carrier, but also serves as a diffusion path for a reaction target substance such as a gas and as a power supply.

The reaction formula in the production of sodium hydroxide is as follows.
Reaction at cathode 2H ₂ O + 2e ⁻ → H ₂ + 2OH
Reaction at anode 2Cl ⁻ → Cl ₂ + 2e ⁻
Total reaction 2H ₂ O + 2NaCl → 2NaOH + Cl ₂ + H ₂
The reason why titanium is used as a base material for an anode for producing sodium hydroxide is that the anode potential is very high. When stainless steel, copper, nickel or the like is used as the anode base material, elution may occur when the anode potential becomes high.

  Regarding the selection of the base material, it is preferable to select a material that is not easily dissolved by the potential applied to the electrode during a desired reaction. For example, as the cathode base material accompanied with hydrogen generation in the reaction formula, stainless steel, copper, carbon and the like can be used in addition to titanium.

  In the above example, a porous body as a base material is shown. However, it is also possible to use a material having catalytic action such as Pt, Ni, Pd or the like as a porous body electrode by processing it into a porous structure.

  Here, when a large number of holes are opened in a substrate made of a conductive plate having a certain thickness by a method capable of mass production such as expanding, etching, punching, etc., the smaller the substrate thickness, the smaller the opening is processed. Is possible. In general, it is difficult to shorten the distance between the openings than the thickness of the substrate due to the problem of workability. For this reason, when trying to open a large number of holes per unit area as much as possible (when increasing the numerical aperture density), the thinner the substrate, the shorter the distance between the openings, which is advantageous.

  An electrode using such a porous base material is used for an electrode of a zero gap electrochemical cell or the like. In the zero gap electrochemical cell, the electrode is disposed in close contact with the solid electrolyte membrane without any gap.

  The electrochemical reaction in this electrochemical cell occurs at the interface between the electrolyte membrane to which ions can move and the catalyst. Considering the mass transfer of the reaction target substance or product, the shorter the distance between the openings, the shorter the distance traveled through the narrow path where the electrolyte membrane and the electrode are in close contact. The shorter the diffusion distance, the lower the diffusion resistance, so the voltage applied to the electrochemical cell decreases.

Another important factor for the reaction to proceed in the electrochemical cell is the reaction area. The reaction area increases as the aperture ratio of the electrode using the porous base material decreases.
For this reason, at the same aperture ratio, the higher the aperture density, the higher the reaction rate can be realized.

  By the way, when the base material of an electrode is made thin, it is anticipated that the conductive path of the base material itself becomes thin and the current collection resistance increases. Therefore, attempts have been made to lower the current collecting resistance by joining a current collecting plate or a power feeding plate to an electrode base material having a mesh structure.

  However, in this configuration, when electrolyte ions enter the current collector plate and the power supply plate, as in the case of the electrode substrate, select a material that does not melt at the potential at which the reaction occurs (hereinafter referred to as the reaction potential) It is necessary to form a current collector plate and a power supply plate.

  Furthermore, even if the material does not dissolve at the reaction potential, contact resistance with the electrode increases when the current collector plate or power supply plate is formed of a material that forms an oxide film on its surface, such as titanium or aluminum. Resulting in. Therefore, it is necessary to coat the surface of the material forming the current collector plate or the power supply plate with a corrosion-resistant substance so that the material forming the current collector plate or the power supply plate does not oxidize directly in contact with the electrode.

For example, a potential higher than 1.23 Vvs RHE is applied to the anode of an electrolysis cell that electrolyzes water.
For this reason, it is necessary to use an anode in which the surface of titanium, which is a conductive plate or a power supply plate, is coated with sputtering or plating with platinum (Pt) that is difficult to dissolve at this potential.

JP 2006-63419 A

  The embodiment has a simple configuration, can improve the reaction rate and power supply performance at the interface with the electrolyte membrane, and is less susceptible to corrosion based on the reaction potential, an oxygen reduction device using the cell, and The object is to provide a refrigerator and an electrochemical device using this oxygen reduction device.

In order to solve the above problems, the electrochemical cell of the embodiment includes an anode, a cathode, and an electrolyte membrane sandwiched therebetween. At least one of the anode and the cathode is formed of a single conductive plate configured integrally. At least one of the electrodes has a first surface in contact with the electrolyte membrane and a second surface spaced from the first surface in the thickness direction. The at least one electrode has a plurality of first holes opened to the first surface and a plurality of second holes opened to the second surface. It communicates with a part of the first hole. Each first hole is made smaller than each second hole, the opening density of the first surface is larger than the opening density of the second surface, and the number of first holes 14 is 30. / Cm ² or more.

It is a perspective view which shows roughly the anode used for the electrochemical cell which concerns on 1st Embodiment. It is a schematic sectional drawing of the anode shown along the F2-F2 line | wire of FIG. It is sectional drawing which expands and shows a part of anode of FIG. It is a graph which shows the relationship between the cell voltage of the electrochemical cell which concerns on 1st Embodiment, and the opening density of the 1st surface of an anode. It is sectional drawing which shows typically the structure of the electrochemical apparatus provided with the electrochemical cell of FIG. 1 as an electrolysis cell. It is sectional drawing which shows typically an example of the oxygen reduction apparatus which concerns on 2nd Embodiment. It is sectional drawing which shows typically the other example of the oxygen reduction apparatus which concerns on 2nd Embodiment. It is sectional drawing which shows typically the further another example of the oxygen reduction apparatus which concerns on 2nd Embodiment. It is a figure which shows typically the refrigerator which concerns on 3rd Embodiment.

(First embodiment)
The electrochemical cell of the first embodiment indicated by reference numeral 1 in FIG. 5 includes an anode 11, a cathode 31, and an electrolyte membrane 35 sandwiched between them.

  The anode 11 is a member that forms an electrode of the electrochemical cell 1 and plays a role not only as a catalyst carrier but also as a diffusion path of a reaction target substance such as a gas, and a current collector and a power feeder. The anode 11 includes an electrode base material (also referred to as an anode base material) and a catalyst layer 16 (see FIG. 3) formed on one surface of the base material. May be configured.

  The electrode base material of the anode 11 is formed of an integrally conductive single plate. The anode 11 made of a single plate has a first surface 12 and a second surface 13 as shown in FIGS. The first surface 12 is a surface in contact with the electrolyte membrane 35 and functions as a reaction surface (electrolytic surface). The second surface 13 is a surface spaced from the first surface 12 in the thickness direction, and is parallel to the first surface 12, for example. The second surface 13 not in contact with the electrolyte membrane 35 functions as a power feeding surface.

  Examples of the element constituting the electrode base material that supports the catalyst layer (also referred to as the anode catalyst layer) of the anode 11 include metal elements such as Ta, Ti, SUS, and Ni, or carbon. These elements are properly used depending on the reaction potential of the anode 11. Criteria for selecting such elements can generally be confirmed by a pH-potential diagram or the like. For example, in the case of an anode electrode base material used for sodium hydroxide production, Ni and SUS are eluted and cannot be used, and titanium (Ti) must be used.

  When the electrode base material itself functions as a catalyst and is active in the reaction, the anode 11 can be formed by this base material itself, and therefore this electrode does not require a catalyst layer. As an element forming such an electrode substrate, for example, platinum (Pt) can be cited. Furthermore, the anode 11 can also be used as a soluble electrode whose electrode is consumed with the reaction according to the use conditions of the electrochemical cell 1.

  As shown in FIGS. 2 and 3, the anode 11 has a porous structure. That is, the anode 11 has a plurality of first holes 14 and a plurality of second holes 15, and the second holes 15 are communicated with a part of the first holes 14. Yes. Each first hole 14 is open to the first surface 12, and each second hole 15 is open to the second surface 13.

  As shown in FIG. 2, the thickness T3 of the region on the second surface 13 side of the anode 11 in which each second hole 15 is formed is the first thickness of the anode 11 in which each first hole 14 is formed. It is thicker than the thickness T2 of the region on the surface 12 side. As a result, the second hole 15 is formed deeper in the thickness direction of the electrode substrate than the first hole 14.

  Furthermore, as shown in FIG. 3, each second hole 15 is narrower toward the first hole 14 connected to the second hole 15 (in other words, closer to the first surface 12), and second The surface 13 is formed wider toward the side (in other words, the farther away from the first hole portion 14).

  The anode 11 having the structure described above can be manufactured by wet-etching a conductive electrode substrate using, for example, various etching solutions. In this case, one side of the electrode substrate made of a single plate may be etched one by one, or both sides of the electrode substrate may be etched simultaneously, and the masking and etching methods are not limited.

  In order to etch the electrode base material one side at a time, the etching may be performed while covering one side to be etched with a mask member having a plurality of predetermined openings and covering the other side with the mask member. Further, in order to simultaneously etch both surfaces of the electrode substrate, the etching may be performed in a state where both surfaces of the electrode substrate are respectively covered with a mask member having a plurality of predetermined openings.

  Further, as the type of etching, photo etching or the like can be considered in addition to wet etching, and it can be applied to manufacture of the anode 11. Note that the anode 11 can be manufactured not only by etching but also by processing using laser, precision cutting, or the like.

  Each first hole 14 is formed smaller than each second hole 15. Furthermore, the opening density of the first hole 14 on the first surface 12 is larger than the opening density of the second hole 15 on the second surface 13.

In this case, the number of the first holes 14 is preferably 30 / cm ² or more, and more preferably 200 / cm ² or more. This is set based on the test results shown in FIG.

  FIG. 4 shows a sample having the configuration shown in FIGS. 1 and 2 and having various numbers of the first holes 14, and using these samples as the anodes of the electrochemical cells. It is the result of measuring the voltage applied in between.

As a result, it was confirmed that the cell voltage rapidly increased when the opening density of the first hole portion 14 was less than 30 / cm ² . At the same time, it was confirmed that the cell voltage gradually decreased when the opening density of the first hole portion 14 was 30 / cm ² to less than 200 / cm ² . Furthermore, when the opening density of the first hole portion 14 exceeded 200 / cm ² , it was confirmed that the cell voltage tended to drop abruptly as compared with the case where the opening density was lower than this. Therefore, in order to suppress the cell voltage applied to the electrochemical cell 1 to 1.2 V or less, it is preferable to set the aperture ratio of the first hole portion 14 as described above.

On the other hand, the number of the second holes 15 opened on the second surface 13 may be adjusted according to the required current collecting performance or power feeding performance, and is set to 30 / cm ² or less, for example.

  In the anode 11 having the catalyst layer 16, an anode catalyst layer (not shown) is formed on the first surface 12 of the electrode substrate. The catalyst material forming the catalyst layer 16 needs to be properly used according to the reaction at the anode 11.

  For example, platinum-based catalysts (including PtCo, PtFe, PtNi, PtPd, PtIr, PtRu, PtSn, etc.) are used as the material for forming the anode catalyst layer for fuel cells that perform electrolytic hydrogen generation, hydrogen oxidation, methanol oxidation, etc. It is more preferable to use However, other metal catalysts, nitrogen-substituted carbon catalysts, oxide catalysts, and the like can also be used.

  In addition, as a material for forming a catalyst layer for an anode for salt electrolysis or an anode for oxygen generation, a metal catalyst such as platinum or palladium, a lead oxide, an iridium composite oxide, a ruthenium composite oxide, an oxide catalyst, or the like should be used. Can do. Examples of methods for producing these catalysts include a thermal decomposition method, a sol-gel method, a complex polymerization method, and a sputtering method. Examples of the composite metal forming the oxide include at least one of Ti, Nb, V, Cr, Mn, Co, Zn, Zr, Mo, Ta, W, Tl, Ru, and Ir.

  The cathode 31 that forms the counter electrode of the anode 11 is a member that forms an electrode formed in a porous structure. The cathode 31 can be made of stainless steel, copper, carbon or the like in addition to titanium.

  The anode 11 having the above configuration can be suitably used as an electrode for soda electrolysis or water splitting, but is not limited to these applications, and can be used as a general zero gap electrode.

  The cathode 31 forming the counter electrode of the anode 11 includes an electrode base material (also referred to as a cathode base material) and a catalyst layer (referred to as a cathode catalyst) formed on one surface of the base material. And the electrode base material itself.

  Examples of the element constituting the electrode base material that supports the catalyst layer of the cathode 31 include metal elements such as Ta, Ti, SUS, and Ni, a gas diffusion layer (GDL) composed of carbon or carbon, and the like. These elements are properly used depending on the reaction potential of the cathode 31. As a catalyst for oxygen reduction oxidation reaction for fuel cells and oxygen reduction elements, platinum-based catalysts (including Pt, PtCo, PtFe, PtNi, PtPd, PtIr, PtRu, PtSn, etc.) are more preferable, but other metal catalysts, nitrogen A substituted carbon catalyst, an oxide catalyst, or the like can also be used.

  Moreover, as a cathode for salt electrolysis or a cathode for oxygen generation, silver, palladium, platinum or the like is preferable, and other metal catalysts, nitrogen-substituted carbon catalysts, oxide catalysts, and carbon can also be used.

  The catalyst layer of the cathode 31 can be produced on the electrode substrate by sputtering, or can be produced by directly applying a suspension in which the catalyst powder is dispersed with water, alcohol or the like to the electrode substrate. it can. If the electrode base material itself functions as a catalyst and is active in the reaction in addition to the catalyst application on the electrode base material as described above, the cathode 31 can be formed with this base material itself. This electrode does not require a catalyst layer. As an element forming such an electrode substrate, for example, platinum (Pt) can be cited. Furthermore, the anode 11 can also be used as an elution electrode that is consumed with the reaction according to the use conditions of the electrochemical cell 1.

  As the electrolyte membrane 35, a polymer electrolyte membrane, for example, a cation exchange solid polymer electrolyte membrane, specifically, a cation exchange membrane, an anion exchange membrane, or a hydrocarbon membrane may be used. it can. Examples of the cation exchange membrane include NAFION (EI DuPont: registered trademark) 112, 115, 117, Flemion (Asahi Glass Co., Ltd .: registered trademark), ACIPLEX (Asahi Kasei Corporation: registered trademark), Gore Select (W.L.). , Gore and Associates: registered trademark). Examples of the anion-exchange membrane include A201 manufactured by Tokuyama Corporation.

  In the electrochemical cell 1 having the above-described configuration, the electrolyte membrane 35 and the anode 11 are joined by hot pressing with the electrolyte membrane 35 sandwiched between the anode 11 and the cathode 31, and the electrolyte membrane 35 and the cathode 31 are joined. Is produced.

  An electrochemical device 2 provided with the electrochemical cell 1 as an electrolytic cell is shown in FIG. 5 is divided into a cathode chamber 4 and an anode chamber 5 by a partition member, for example, a partition wall 3 and an electrochemical cell 1. An electrochemical cell 1 is attached to the partition wall 3. Thereby, for example, the electrochemical cell 1 is disposed in the electrolytic vessel 10 so that the joining direction of each member constituting the electrochemical cell 1 is the same as the vertical direction. The anode 11 of the electrochemical cell 1 faces the anode chamber 5 that occupies the lower portion of the electrolytic vessel 10, and the cathode 31 faces the cathode chamber 4 that occupies the upper portion of the electrolytic vessel 10.

  The electrochemical device 2 further includes voltage application means such as a DC power source 6, voltage detection means such as a voltmeter 7, current detection means such as an ammeter 8, and control means 9.

  Both poles of the power source 6 are electrically connected to the anode 11 and the cathode 31. The power source 6 applies a voltage to the electrochemical cell 1 according to control by the control means 9. The voltmeter 7 is electrically connected to the anode 11 and the cathode 31 and detects a cell voltage applied to the electrochemical cell 1. The detection information is supplied to the control means 9. The ammeter 8 is inserted in a voltage application circuit for the electrochemical cell 1 and detects a cell current flowing through the electrochemical cell 1. The detection information is supplied to the control means 9. The control means 9 controls the application or load of voltage to the electrochemical cell 1 by the power source 6 according to the detection information in accordance with the program stored in the memory of the control means 9.

  In addition, when the electrochemical cell 1 is used for a battery reaction, a voltage is loaded with respect to this cell. When the electrochemical cell 1 is used for a reaction other than the battery reaction, such as a hypoxia reaction, a voltage is applied to the cell. In addition, when implementing as the electrochemical apparatus 2 which performs a battery reaction, the power supply 6 is abbreviate | omitted.

  The electrochemical device 2 applies an electrochemical voltage for electrolysis by applying or loading a voltage between the anode 11 and the cathode 31 in a state where the reaction target substance is supplied to the cathode chamber 4 and the anode chamber 5. Alternatively, an electrochemical reaction for battery reaction is allowed to proceed.

  Since the anode 11 included in the electrochemical cell 1 having the above-described configuration is formed of a single conductive plate configured integrally, the anode 11 serves as an electrode and a current collecting member (or a power feeding member). Thereby, since it is not necessary to install a current collection member with respect to the anode 11, the components of the electrochemical cell 1 are reduced. In addition, unlike the case where a current collecting member is provided for the anode 11, there is no need to perform special processing for imparting resistance to corrosion based on the reaction potential to the current collecting member. Therefore, the structure of the electrochemical cell 1 can be simplified, and the interface corrosion between the current collector and the anode does not occur.

  The electrochemical reaction in the electrochemical cell 1 occurs at the interface between the electrolyte membrane 35 and the first surface 12 of the anode 11. In this case, the integrally structured anode 11 that also serves as a current collecting member does not have an interface with a portion corresponding to the current collecting member. For this reason, although the electrolyte ions enter the anode 11, the ions do not diffuse, and therefore the corrosion of the anode 11 based on the reaction potential hardly occurs.

  At the same time, the anode 11 having a porous structure has a plurality of first holes 14 opened on the first surface 12 in contact with the electrolyte membrane 35 and a plurality of second holes opened on the second surface 13. 15 and the opening density of the first surface 12 is higher than the opening density of the second surface 13, the reaction rate at the interface with the electrolyte membrane 35 can be improved.

  Furthermore, since the anode 11 also serves as a current collecting member, the entire thickness T1 is thicker than the thickness T2 of the region where the first hole 14 is formed. Thereby, the current collecting resistance of the anode 11 is lowered, and the power feeding performance can be improved. In addition, in this embodiment, the thickness T3 of the region on the second surface 13 side of the anode 11 where the second hole 15 is formed is equal to the first thickness of the anode 11 where the first hole 14 is formed. Since it is thicker than the thickness T2 of the region on the surface 12 side, the power feeding performance can be further improved.

  Further, the second hole portion 15 of the anode 11 is formed to be narrower toward the first hole portion 14 connected to the anode 11 and wider toward the second surface 13 side. For this reason, a product such as water produced by the reaction at the anode 11 can be smoothly flowed out from the second hole 15, and the reaction is reduced due to the residence of the product in the anode 11. Can be suppressed.

  The electrochemical cell 1 shown in FIG. 5 and the electrochemical device 2 provided with the same were produced, and water electrolysis characteristics were evaluated using the electrochemical device 2. The anode 11 used in this Example 1 has an electrode substrate formed of a single conductive plate integrally formed as described above.

In Example 1, the cathode 31 described below was used. 5 mL of water and 3 mL of 5 wt% NAFION (registered trademark) solution are mixed with 705 mg of Pt / C (Tanaka Kikinzoku Kogyo Co., Ltd.). Disperse this mixture with ultrasound for 30 minutes. The suspension formed thereby was sprayed onto carbon paper (GDL25BC manufactured by CETEK, thickness 0.32 mm, area 235 cm ² ) subjected to water repellent treatment (20 wt%) and dried. The dried carbon paper was cut into 3 × 4 cm and used as the cathode 31.

Furthermore, in Example 1, the anode 11 described below was used. A solution prepared by adding 1-butanol to 0.25 M (Ir) to iridium chloride (IrCl ₃ .nH ₂ O) was treated in advance in an aqueous 10 wt% oxalic acid solution at 80 ° C. for 1 hour. The solution thus prepared was applied to the first surface 12 of the electrode substrate of the anode 11 and then dried and fired. In this case, drying is performed at 80 ° C. for 10 minutes. Firing was performed at 450 ° C. for 10 minutes. An electrode base material obtained by repeating such coating, drying, and firing five times was cut out into 3 cm × 4 cm and used as the anode 11.

  In this case, the electrode base material is made of titanium, the thickness T1 (see FIG. 2) is 0.5 mm, and the thickness T2 of the region including the first hole 14 is 0.15 mm, and the second hole. The thickness T3 of the region including the portion 15 is 0.35 mm. Further, the width W (see FIG. 1) of the linear portion left by making a mesh at the communication portion between the first hole portion 14 and the second hole portion 15 is 0.1 mm, and the linear portion is made of the linear portion. The width LW (see FIG. 1) of the longer opening of the formed rhombus is 0.57 mm. In addition, W of the wide linear portion remaining on the second surface 13 is 1.0 mm, and LW is 2.0 mm. The angle θ (see FIG. 1) of the second hole 15 opened in a diamond shape is 120 °. The width W of the linear portion is formed so as to satisfy the formula of T1 ≦ W in relation to the thickness T1 of the electrode substrate.

  Next, between the anode 11 and the cathode 31 produced as described above, a polymer electrolyte membrane 35 of 50 μm thick NAFION (registered trademark) 211 is sandwiched from both sides, and this is placed at 150 ° C. and a pressure of 0.36 MPa. Was subjected to hot pressing for 3 minutes to produce an electrochemical cell 1 as a membrane electrode assembly used in Example 1.

  In the electrochemical device 2 of Example 1, the pure water is put into the anode chamber 5 and the cathode chamber 4, respectively, and a voltage is applied between the electrodes of the electrochemical cell 1, that is, between the anode 11 and the cathode 31 by the power source 6. And drove. Thereby, electrolysis of water occurred, oxygen was generated from the anode 11, and hydrogen was generated from the cathode 31.

The reaction formula in this case is as follows.
Reaction at cathode 31 H ₂ → 2H ⁺ + 2e ⁻
Reaction at anode 11 2H ₂ O → 2O ₂ + 4e ⁻ + 4H ⁺
Total reaction 2H ₂ O → 2H ₂ + O ₂
The 100 kHz impedance resistance in the electrochemical device 2 of Example 1 is 44.6 mΩ in one hour after the start of operation. At that time, the electrolytic voltage required for a cell current of 200 mA / cm ² to flow is 1. It was 94V. The impedance resistance after electrolysis for 50 hours from the start of operation was 47 mΩ, and the electrolysis voltage at that time was 1.94V.

(Comparative Example 1)
The first substrate has the same opening diameter as the first surface, the same opening diameter and opening density as the second surface, and has the same thickness as in Example 1 (titanium, thickness 0.5 mm, W 1.0 mm, LW 2.0 mm). , Θ was 120 °), and a porous anode prepared by coating iridium oxide as an anode catalyst in the same manner as in Example 1 was prepared. An electrochemical device of Comparative Example 1 having this anode was prepared, and water was electrolyzed under the same conditions as in Example 1.

The 100 kHz impedance resistance in the electrochemical device of Comparative Example 1 was 52 mΩ in one hour after the start of operation, and the electrolytic voltage required for a 200 mA / cm ² cell current to flow at that time was 2.28 V. .

  On the other hand, in the electrochemical device 2 of Example 1 provided with the anode 11 in which the electrode base material and the current collecting member are integrally formed, the resistance and the electrolysis voltage are lower than those of Comparative Example 1, so that the superiority is clear. It is.

(Comparative Example 2)
Porous structure produced by coating a titanium electrode substrate (T1 0.1 mm, W 0.1 mm, LW 0.57 mm, θ 120 °) with iridium oxide as an anode catalyst as in Example 1. An anode was prepared. An anode joined body was prepared by superimposing a titanium power supply plate (thickness: 0.4 mm, W: 1.0 mm, LW: 2.0 mm, θ: 120 °) whose surface was not subjected to corrosion resistance treatment on the anode. An electrochemical device of Comparative Example 2 provided with this anode assembly was prepared, and water was electrolyzed under the same conditions as in Example 1.

The 100 kHz impedance resistance in the electrochemical device of Comparative Example 2 was 52 mΩ in one hour after the start of operation, and at that time, the electrolytic voltage required for a cell current of 200 mA / cm ² to flow was 1.95 V. . The impedance resistance after electrolysis for 50 hours from the start of operation was 500 mΩ, and the electrolysis voltage at that time was 3.00V.

  The result of this comparative example 2 shows that even if a titanium plate not subjected to corrosion resistance treatment is used as a power supply plate, it is corroded.

  On the other hand, the electrochemical device 2 of Example 1 including the anode 11 in which the electrode base material and the current collecting member are integrally formed has resistance and electrolysis voltage even after electrolysis for 50 hours from the start of operation. Since it can be kept lower than Comparative Example 2, the superiority is clear.

(Comparative Example 3)
Porous structure produced by coating a titanium electrode substrate (T1 0.1 mm, W 0.1 mm, LW 0.57 mm, θ 120 °) with iridium oxide as an anode catalyst as in Example 1. An anode was prepared. An anode joined body in which a titanium power supply plate (thickness: 0.4 mm, W: 1.0 mm, LW: 2.0 mm, θ: 120 °), which is not subjected to corrosion resistance treatment on the anode, is spot welded to the anode. Prepared. Spot welding was performed every 1 cm on an anode assembly having a size of 3 × 4 cm, and the spot welding area was 4 mm ² . The electrochemical device of Comparative Example 3 provided with this anode assembly was prepared, and water was electrolyzed under the same conditions as in Example 1.

The 100 kHz impedance resistance in the electrochemical device of Comparative Example 3 was 51 mΩ 1 hour after the start of operation, and at that time, the electrolysis voltage required for a cell current of 200 mA / cm ² to flow was 1.95 V. . The impedance resistance after electrolysis for 200 hours from the start of operation was 200 mΩ, and the electrolysis voltage at that time was 2.5V.

  This result shows that the characteristics are insufficient in an electrochemical device including an anode assembly in which an electrode substrate coated with iridium oxide and a power supply plate not coated are joined by welding. Such a phenomenon is considered as follows. That is, since there is a conductive path only at the welded portion, after a long period of operation of the electrochemical device, corrosion at the intermetallic interface other than the welded portion proceeds with time. As a result, the absolute amount of the conductive path between the electrode substrate having the mesh structure and the power supply plate was insufficient, and the impedance resistance was increased.

  On the other hand, the electrochemical device 2 of Example 1 including the anode 11 in which the electrode base material and the current collecting member are integrally formed has resistance and electrolysis voltage even after electrolysis for 200 hours from the start of operation. Since it can be kept lower than Comparative Example 3, the superiority is clear.

  Similarly to Example 1, the electrochemical cell 1 was provided and the electrochemical device 2 shown in FIG. In this case, the cathode chamber 4 is filled with pure water, and the anode chamber 5 is filled with a NaCl aqueous solution, specifically, saturated saline, between the electrodes of the electrochemical cell 1, that is, between the anode 11 and the cathode 31. In addition, a voltage was applied from the power source 6 to drive the system. As a result, electrolysis occurred, chlorine was generated from the anode 11, and sodium hydroxide was generated at the cathode 31.

The 100 kHz impedance resistance in the electrochemical device 2 of Example 2 is 45 mΩ in one hour after the start of operation. At that time, the electrolytic voltage necessary for a cell current of 200 mA / cm ² to flow is 1.50 V. there were. The impedance resistance after electrolysis for 200 hours from the start of operation was 45 mΩ, and the electrolysis voltage at that time was 1.52.

(Comparative Example 4)
An electrode base material having the same opening diameter and opening density on the first surface and the second surface and the same thickness as in Example 1 (made of titanium, T1 is 0.5 mm, W is 1.0 mm, LW is 2.0 mm) , Θ was 120 °), and a porous anode prepared by coating iridium oxide as an anode catalyst in the same manner as in Example 1 was prepared. An electrochemical device of Comparative Example 4 having this anode was prepared, and salt electrolysis was performed under the same conditions as in Example 2.

  The 100 kHz impedance resistance in the electrochemical device of Comparative Example 4 was 47 mΩ 1 hour after the start of operation, and the electrolytic voltage required for a cell current of 200 mA / cm 2 to flow at that time was 1.73 V.

  On the other hand, the electrochemical device 2 of Example 2 including the anode 11 in which the electrode base material and the current collecting member are integrally formed has lower resistance and electrolysis voltage than those of Comparative Example 4, so that the superiority is clear. It is.

(Comparative Example 5)
Porous structure produced by coating a titanium electrode substrate (T1 0.1 mm, W 0.1 mm, LW 0.57 mm, θ 120 °) with iridium oxide as an anode catalyst as in Example 1. An anode was prepared. An anode joined body was prepared by superimposing a titanium power supply plate (thickness: 0.4 mm, W: 1.0 mm, LW: 2.0 mm, θ: 120 °) whose surface was not subjected to corrosion resistance treatment on the anode. An electrochemical device of Comparative Example 2 provided with this anode assembly was prepared, and salt electrolysis was performed under the same conditions as in Example 2.

The 100 kHz impedance resistance in the electrochemical device of Comparative Example 5 was 45 mΩ 1 hour after the start of operation, and the electrolytic voltage required for a cell current of 200 mA / cm ² to flow at that time was 1.51 V. . The impedance resistance after electrolysis for 200 hours from the start of operation was 450 mΩ, and the electrolysis voltage at that time was 2.80V.

  This result shows that even if a titanium plate that has not been subjected to corrosion resistance treatment is used as a power supply plate, corrosion occurs.

  On the other hand, the electrochemical device 2 of Example 2 including the anode 11 in which the electrode base material and the current collecting member are integrally formed has resistance and electrolysis voltage even after electrolysis for 200 hours from the start of operation. Since it can be kept lower than Comparative Example 5, the superiority is clear.

(Comparative Example 6)
Porous structure produced by coating a titanium electrode substrate (T1 0.1 mm, W 0.1 mm, LW 0.57 mm, θ 120 °) with iridium oxide as an anode catalyst as in Example 1. An anode was prepared. An anode assembly in which a titanium power supply plate (thickness: 0.4 mm, W: 1.0 mm, LW: 2.0, θ: 120 °), which is not subjected to corrosion resistance treatment on the anode, is spot-welded with this anode. Prepared. Spot welding was performed every 1 cm on an anode assembly having a size of 3 × 4 cm, and the spot welding area was 4 mm ² . An electrochemical device of Comparative Example 6 provided with this anode assembly was prepared, and salt electrolysis was performed under the same conditions as in Example 1.

The 100 kHz impedance resistance in the electrochemical device of Comparative Example 6 was 46 mΩ in one hour after the start of operation, and the electrolytic voltage necessary for a cell current of 200 mA / cm ² to flow at that time was 1.50 V. . The impedance resistance after electrolysis for 200 hours from the start of operation was 190 mΩ, and the electrolysis voltage at that time was 2.0V.

  This result shows that the characteristics are insufficient in an electrochemical device including an anode assembly in which an electrode substrate coated with iridium oxide and a power supply plate not coated are joined by welding. Such a phenomenon is considered as follows. That is, since there is a conductive path only at the welded portion, after a long period of operation of the electrochemical device, corrosion at the intermetallic interface other than the welded portion proceeds with time. As a result, the absolute amount of the conductive path between the electrode substrate having the mesh structure and the power supply plate was insufficient, and the impedance resistance was increased.

  On the other hand, the electrochemical device 2 of Example 2 including the anode 11 in which the electrode base material and the current collecting member are integrally formed has resistance and electrolysis voltage even after electrolysis for 200 hours from the start of operation. Since it can be kept lower than Comparative Example 6, the superiority is clear.

(Second Embodiment)
The second embodiment shows an electrochemical device that includes the electrochemical cell 1 described in the first embodiment and is used as an oxygen reducing device, an oxygen concentrating device, a humidifying device, or a dehumidifying device. Accordingly, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The first electrochemical device 2A schematically shown in FIG. 6 includes an electrochemical cell 1, an electrolytic vessel 10, a partition member such as a sealing material 21, a voltage applying means such as a DC power source 6, and a control means 9. have.

  The electrochemical cell 1 is disposed in the electrolytic vessel 10 so that the joining direction of each member constituting the electrochemical cell 1 is orthogonal to the vertical direction, and is supported by the electrolytic vessel 10 via a sealing material 21. The electrolytic cell 10 is partitioned into the cathode chamber 4 and the anode chamber 5 by the electrochemical cell 1 and the sealing material 21. The anode 11 of the electrochemical cell 1 faces the anode chamber 5, and the cathode 31 faces the cathode chamber 4.

  Both poles of the power source 6 are electrically connected to the anode 11 and the cathode 31. The power source 6 applies a voltage to the electrochemical cell 1 according to control by the control means 9. The control means 9 controls the application of voltage to the electrochemical cell 1 by the power supply 6 according to the program stored in the memory it has. In the first electrochemical device 2 </ b> A, the electrochemical cell 1 may be supported in a semi-fixed state so as to be detachable from the electrolytic vessel 10.

  The electrolytic container 10 included in the second electrochemical device 2B schematically shown in FIG. 7 includes a first container member 10a that partitions the cathode chamber 4 and a second container member 10b that partitions the anode chamber 5. Is formed. The first container member 10a and the second container member 10b are detachably connected. The electrochemical cell 1 is supported on one of the first container member 10a and the second container member 10b, for example, the first container member 10a via a sealing material 21. In this case, the electrochemical cell 1 may be supported in a semi-fixed state so as to be removable from the container member to which the electrochemical cell 1 is attached. The configurations other than those described above are the same as those of the first electrochemical device 2A shown in FIG.

  In the operation of the first electrochemical device 2A and the second electrochemical device 2B configured as described above, an acidic membrane is used for the electrolyte membrane 35, water is supplied to the anode chamber 5, and air is supplied to the cathode chamber 4. It is performed in the state. By this operation, a reaction for decomposing water into oxygen and protons occurs in the anodes 11 of the first electrochemical device 2A and the second electrochemical device 2B. Therefore, the first electrochemical device 2A and the second electrochemical device 2B function as an oxygen concentrator or a dehumidifier.

The reaction at the anode 11 and the cathode 31 in this case is as follows.
Reaction at cathode 31 2O ₂ + 4e ⁻ + 4H ⁺ → 2H ₂ O
Reaction at anode 11 2H ₂ O → 2O ₂ + 4e ⁻ + 4H ⁺
On the other hand, by the above operation, in the cathode 31 of the first electrochemical device 2A and the second electrochemical device 2B provided with an electrolytic cell (electrochemical cell 1) using an acidic electrolyte membrane 35, the cathode chamber 4 Oxygen supplied to the proton reacts with protons generated at the anode 11 and ionically conducted to the cathode 31 through the electrolyte membrane 35 to generate water. Accordingly, the first electrochemical device 2A and the second electrochemical device 2B function as an oxygen reduction device or a humidification device.

  In the first electrochemical device 2A and the second electrochemical device 2B, when the electrolyte membrane 35 is neutral or alkaline, water is consumed at the anode 11 and water is generated at the cathode 31. Cause a reaction.

That is, it functions in the opposite manner to the case of using an acidic electrolyte membrane 35. The reaction at the anode 11 and the cathode 31 in this case is as follows.
Reaction at cathode 31 O ₂ + 2H ₂ O + 4e ⁻ → 4OH ⁻
Reaction at anode 11 4OH ⁻ → O ₂ + 2H ₂ O + 4e ⁻
Therefore, when the first electrochemical device 2A and the second electrochemical device 2B are implemented as a humidifier for humidification or a dehumidifier for dehumidification, the electrolytic vessel 10 is used as a water supply container or a water storage container. Use it.

  The third electrochemical device 2C schematically shown in FIG. 8 is an embodiment as an oxygen reduction device that obtains an oxygen concentration lower than the oxygen concentration in the air. The third electrochemical device 2C includes an electrochemical cell 1 used as an oxygen reducing cell, an electrolytic vessel 10 used as an oxygen reducing container, a partition member such as a sealing material 21, and a voltage applying means such as a direct current. A power source 6 and a control means 9 are provided.

  The electrochemical cell (oxygen reduction cell) 1 is disposed in the electrolytic vessel 10 so that the joining direction of each member constituting the electrochemical cell 1 is orthogonal to the vertical direction, and is supported by the electrolytic vessel 10 through the sealing material 21. Has been. The electrolytic cell 10 is partitioned into the cathode chamber 4 and the anode chamber 5 by the electrochemical cell 1 and the sealing material 21. The anode 11 of the electrochemical cell 1 faces the anode chamber 5, and the cathode 31 faces the cathode chamber 4.

  Both poles of the power source 6 are electrically connected to the anode 11 and the cathode 31. The power source 6 applies a voltage to the electrochemical cell 1 according to control by the control means 9. The control means 9 controls the application of voltage to the electrochemical cell 1 by the power supply 6 according to the program stored in the memory it has. In the third electrochemical device 2 </ b> C, the electrochemical cell 1 may be supported in a semi-fixed state so as to be detachable from the electrolytic vessel 10.

  An acidic material is used for the electrolyte membrane 35 of the third electrochemical device (oxygen reduction device) 2C. The cathode chamber 4 of the third electrochemical device 2C is used as an oxygen reduction chamber. The electrolytic vessel 10 has a door 23. The door 23 is opened and closed when an article such as food to be placed under reduced oxygen is taken in and out of the cathode chamber 4. The anode chamber 5 of the third electrochemical device 2C is used as a water tank.

  The electrolytic vessel 10 has a supply pipe 24 and a discharge pipe 25. The supply pipe 24 is attached in communication with the inside and outside of the anode chamber 5 and supplies water to the anode chamber 5. The discharge pipe 25 communicates with the inside and outside of the anode chamber 5 and is attached to the upper part of the electrolytic vessel 10, and discharges oxygen generated at the anode 11 to the outside of the anode chamber 5.

  In the third electrochemical device 2C, the electrolytic vessel 10 is provided with a member through which an article can be taken in and out and a member for supplying and discharging a gas, liquid or substance such as an intake pipe, an exhaust pipe, a water supply pipe, a drain pipe, etc. You may prepare. These doors and tubes can be of any shape and function depending on the purpose and application of the apparatus.

  In the third electrochemical device 2C, the control means 9 may switch the intake / exhaust, water supply / drainage, sealed area, etc. so that any one of the operations of oxygen reduction, oxygen concentration, dehumidification, or humidification is performed. Good. At the same time, an oxygen concentration meter or a hygrometer may be provided so that the effect of the operation of the third electrochemical device (oxygen reduction device) can be easily confirmed. Furthermore, it may be controlled to have an arbitrary oxygen concentration or humidity. These controls may be controlled electronically by control means 9 using a programmable IC such as a microcomputer or FPGA, or may be controlled manually.

  Similarly to Examples 1 and 2, the electrochemical cell 1 was provided to constitute the third electrochemical device (oxygen reducing device) 2C shown in FIG.

In Example 3, the cathode 31 described below was used. 5 mL of water and 3 mL of 5 wt% NAFION (registered trademark) solution are mixed with 705 mg of Pt / C (Tanaka Kikinzoku Kogyo Co., Ltd.). Disperse this mixture with ultrasound for 30 minutes. The suspension formed thereby was sprayed onto carbon paper (GDL25BC manufactured by CETEK, thickness 0.32 mm, area 235 cm ² ) subjected to water repellent treatment (20 wt%) and dried. The dried carbon paper was cut into 3 × 4 cm and used as the cathode 31.

Furthermore, in Example 3, the anode 11 described below was used. A solution prepared by adding 1-butanol to 0.25 M (Ir) to iridium chloride (IrCl ₃ .nH ₂ O) was treated in advance in an aqueous 10 wt% oxalic acid solution at 80 ° C. for 1 hour. The solution thus prepared was applied to the first surface 12 of the electrode substrate of the anode 11 and then dried and fired. In this case, drying was performed at 80 ° C. for 10 minutes, and baking was performed at 450 ° C. for 10 minutes. An electrode base material obtained by repeating such coating, drying, and firing five times was cut out into 3 cm × 4 cm and used as the anode 11.

  In this case, the electrode base material is made of titanium, and its thickness T1 (see FIG. 2) is 0.5 mm. Among these, the thickness T2 of the region including the first hole 14 is 0.15 mm, and the second The thickness T3 of the region including the hole 15 is 0.35 mm. Further, the width W (see FIG. 1) of the linear portion left by making a mesh at the communication portion between the first hole portion 14 and the second hole portion 15 is 0.1 mm, and the linear portion is made of the linear portion. The width LW (see FIG. 1) of the longer opening of the formed rhombus is 0.57 mm. In addition, W of the wide linear portion remaining on the second surface 13 is 1.0 mm, and LW is 2.0 mm. The angle θ (see FIG. 1) of the second hole 15 opened in a diamond shape is 120 °. The width W of the linear portion is formed so as to satisfy the formula of T1 ≦ W in relation to the thickness T1 of the electrode substrate.

  Next, between the anode 11 and the cathode 31 produced as described above, a polymer electrolyte membrane 35 of 50 μm thick NAFION (registered trademark) 211 is sandwiched from both sides, and this is placed at 150 ° C. and a pressure of 0.36 MPa. Was subjected to hot pressing for 3 minutes to produce an electrochemical cell (oxygen-reduced cell) 1 as a membrane electrode assembly.

  The electrochemical device 2C of Example 3 puts pure water into the anode chamber 5 and supplies air to the cathode chamber 4 between the electrodes of the electrochemical cell 1, that is, between the anode 11 and the cathode 31. A voltage was applied by the power source 6 to operate. As a result, electrolysis of water occurred, water was consumed by the reaction at the anode 11, and oxygen was generated. Oxygen was consumed by the reaction at the cathode 31, and water was generated.

The 100 kHz impedance resistance in the electrochemical device 2C of Example 3 is 44.6 mΩ in one hour after the start of operation, and the electrolytic voltage required for a cell current of 200 mA / cm ² to flow at that time is 1. It was 13V.

(Comparative Example 7)
An electrode substrate having the same opening diameter and opening density as the first surface and the same thickness as in Example 3 (titanium, T1 is 0.5 mm, W is 1.0 mm, and LW is 2.0 mm). , Θ was 120 °), and a porous anode prepared by coating iridium oxide as an anode catalyst in the same manner as in Example 1 was prepared. An electrochemical device of Comparative Example 7 having this anode was prepared, and electrolysis (oxygen reduction operation) was performed under the same conditions as in Example 3.

The 100 kHz impedance resistance in the electrochemical device of Comparative Example 4 was 52 mΩ 1 hour after the start of operation, and at that time, the electrolytic voltage required for a cell current of 200 mA / cm ² to flow was 1.57 V. .

  On the other hand, in the electrochemical device 2 of Example 1 provided with the anode 11 in which the electrode base material and the current collecting member are integrally formed, the resistance and the electrolysis voltage are lower than those of Comparative Example 7, so that the superiority is clear. It is.

  Similarly to Examples 1 and 2, the electrochemical cell 1 was provided to constitute the third electrochemical device (oxygen reducing device) 2C shown in FIG. In this case, the anode 11 and the cathode 31 of the electrochemical cell 1 were produced under the same conditions as in Example 3. While supplying humidified air to the anode chamber 5 of the third electrochemical device 2C and supplying dry air to the cathode chamber 4, between the electrodes of the electrochemical cell 1, that is, between the anode 11 and the cathode 31, A voltage was applied by the power source 6 to operate.

  As a result, electrolysis occurred, moisture in the air was consumed due to the reaction at the anode 11, and oxygen was generated, and oxygen was consumed due to the reaction at the cathode 31, and water was generated.

At this time, it was confirmed that the humidity of the air flowing out from the anode chamber 5 was lower than the air humidity supplied to the anode chamber 5. Specifically, when supply air is sent to the supply pipe 24 of the anode chamber 5 at 25 ° C., 300 CCM, and saturated humidity, it is discharged out of the anode chamber 5 through the discharge pipe 25 at an electrolytic voltage of 50 mA / cm ^2. It was confirmed that the humidity of the air was reduced to 51%.

Further, the 100 kHz impedance resistance in the third electrochemical device (oxygen reduction device) 2C shown in FIG. 8 is 45 mΩ in one hour after the start of operation, and a cell current of 50 mA / cm ² flows at this time. The required electrolysis voltage was 1.3V.

(Comparative Example 8)
An electrode substrate having the same opening diameter and opening density as the first surface and the same thickness as in Example 3 (titanium, T1 is 0.5 mm, W is 1.0 mm, and LW is 2.0 mm). , Θ was 120 °), and a porous anode prepared by coating iridium oxide as an anode catalyst in the same manner as in Example 1 was prepared. An electrochemical device of Comparative Example 8 having this anode was prepared, and electrolysis (oxygen reduction operation) was performed under the same conditions as in Example 4.

  The 100 kHz impedance resistance in the electrochemical device of Comparative Example 8 was 46 mΩ 1 hour after the start of operation, and the electrolytic voltage required for a 50 mA / cm 2 cell current to flow at that time was 2.3 V.

  On the other hand, since the electrochemical device 2 of Example 1 including the anode 11 in which the electrode base material and the current collecting member are integrally formed can maintain the resistance and the electrolysis voltage lower than those of the comparative example 8, it is superior. Is clear.

  A third electrochemical device (oxygen reduction device) 2C described in Example 3 was prepared. However, in the electrochemical device 2 </ b> C of Example 5, the cathode 31 having an integral structure similar to the anode 11 was used.

  That is, the cathode 31 was manufactured by processing a pure Pt plate (thickness T1 of 0.5 mm) by etching so as to have a porous structure with different opening densities on both surfaces, and then cutting out to 3 cm × 4 cm. In this case, the etching was performed so that the thickness T2 of the cathode 31 was 0.35 mm and T1 was 0.15 mm. Further, the configuration of the cathode 31 is the same as the configuration of FIG. 1 described for the anode 11, and the configuration of the first surface of the cathode 31 processed by etching is that W is 1.0 mm, LW is 2.0 mm, and θ is 120 °. At the same time, the configuration of the second surface of the cathode 31 processed by etching is as follows: W is 0.1 mm, LW is 0.57 mm, and θ is 120 °.

The anode 11 is manufactured as follows. That is, a solution prepared by adding 1-butanol to 0.25 M (Ir) to iridium chloride (IrCl ₃ .nH ₂ O) was treated in advance in an aqueous 10 wt% oxalic acid solution at 80 ° C. for 1 hour. The solution thus prepared was applied to the first surface 12 of the electrode substrate of the anode 11 and then dried and fired. In this case, drying was performed at 80 ° C. for 10 minutes, and baking was performed at 450 ° C. for 10 minutes. An electrode base material obtained by repeating such coating, drying, and firing five times was cut out into 3 cm × 4 cm and used as the anode 11.

  In this case, the electrode base material is made of titanium, the thickness T1 (see FIG. 2) is 0.5 mm, and the thickness T2 of the region including the first hole 14 is 0.15 mm, and the second hole 15 The thickness T3 of the region including is 0.35 mm. Further, the width W (see FIG. 1) of the linear portion left by making a mesh at the communication portion between the first hole portion 14 and the second hole portion 15 is 0.1 mm, and the linear portion is made of the linear portion. The width LW (see FIG. 1) of the longer opening of the formed rhombus is 0.57 mm. In addition, W of the wide linear portion remaining on the second surface 13 is 1.0 mm, and LW is 2.0 mm. The angle θ (see FIG. 1) of the second hole 15 opened in a diamond shape is 120 °. The width W of the linear portion is formed so as to satisfy the formula of T1 ≦ W in relation to the thickness T1 of the electrode substrate.

  Next, between the anode 11 and the cathode 31 produced as described above, a polymer electrolyte membrane 35 of 50 μm thick NAFION (registered trademark) 211 is sandwiched from both sides, and this is placed at 150 ° C. and a pressure of 0.36 MPa. Was subjected to hot pressing for 3 minutes to produce an electrochemical cell 1 as a membrane electrode assembly.

  The electrochemical device (oxygen reduction device) 2C of Example 5 using the electrochemical cell 1 thus formed as an oxygen reduction cell was operated. Specifically, pure water is supplied to the anode chamber 5 and air is supplied to the cathode chamber 4, and a voltage is applied between the electrodes of the electrochemical cell 1, that is, between the anode 11 and the cathode 31 by the power source 6. The oxygen reduction device was operated.

  As a result, electrolysis occurred, water was consumed by the reaction at the anode 11, and oxygen was generated, and oxygen was consumed by the reaction at the cathode 31, and water was generated.

The 100 kHz impedance resistance in the electrochemical device (oxygen reduction device) of Example 5 is 40 mΩ in one hour after the start of operation, and the electrolytic voltage required for a cell current of 200 mA / cm ² to flow is 1. 2V.

(Third embodiment)
FIG. 9 is a conceptual diagram of a refrigerator 41 provided with an oxygen reduction device 40. The refrigerator main body 42 provided in the refrigerator 41 shown in FIG. In FIG. 9 schematically showing the refrigerator 41, the oxygen reduction chamber 43 is shown with parallel diagonal lines in order to facilitate identification from other refrigerator compartments and freezer compartments.

  A refrigerant circulates through a wall (not shown) that partitions the oxygen reduction chamber 43 as a storage space. Thereby, the oxygen reduction chamber 43 can preserve | save preservation | save objects, such as vegetables withdrawn / inserted, under low temperature. The oxygen reduction chamber 43 is opened in front of the refrigerator main body 42 in order to take in and out the storage object. This opening is opened and closed by an opening / closing member, and the oxygen-reducing chamber 43 is held in a sealed state with the opening / closing member closed.

  The opening / closing member that opens and closes the oxygen-reducing chamber 43 may be a heat-insulating door that is pivotally attached to the refrigerator main body 42, or is moved in the front-rear direction through the front opening of the oxygen-reducing chamber 43. It may be a heat insulating opening / closing lid that also serves as the front wall of the drawer.

  As the oxygen reduction device 40 included in the refrigerator 41, an oxygen reduction device including an electrochemical cell as an oxygen reduction cell, for example, the oxygen reduction device shown in FIG. 8 can be used. In this case, in the oxygen reduction device 40, the cathode 31 (see FIG. 8) can react with oxygen in the oxygen reduction chamber 43, and water is supplied to the anode 11 (see FIG. 8) via a water supply means (not shown). It is arranged as follows. In the case of the refrigerator 41 provided with the electrochemical device shown in FIG. 8 as the oxygen reduction device 40, the door 23 shown in FIG.

  In the refrigerator 41 of FIG. 9, one room of the refrigerator main body 42 is the oxygen reduction chamber 43, but a part of the one room of the refrigerator main body 42 may be the oxygen reduction chamber 43. The oxygen reduction device 40 may be arranged at any position in the refrigerator main body 42. When the oxygen-reducing operation is performed in the storage room for storing fresh food, the oxidation of the food can be suppressed. Further, in the refrigerator 41, a humidifying device or a dehumidifying device including an electrochemical cell as an electrolytic cell may be used instead of the oxygen reducing device 40 using the electrochemical cell as an oxygen reducing cell.

  In addition, the control unit (not shown in FIG. 9) switches the intake / exhaust, water supply / drainage, sealed area, etc., and the number of devices that can be controlled to perform any one of the oxygen reduction operation, the dehumidification operation, and the humidification operation is reduced. You may provide instead of the oxygen apparatus 40. FIG. Furthermore, an oxygen concentration meter or a hygrometer may be provided in the refrigerator main body 42 so that the effect of the oxygen reduction operation of the oxygen reduction device 40 can be easily confirmed. Moreover, you may control so that it may become arbitrary oxygen concentration or humidity. These controls may be realized by electronic control using a programmable IC such as a microcomputer or FPGA, or may be realized by manual control.

  The oxygen reduction device 40 of the refrigerator 41 shown in FIG. 9 performs an oxygen reduction operation by applying a voltage between the anode 11 and the cathode 31. Thus, when the oxygen reduction device 40 is operated, the oxygen concentration in the oxygen reduction chamber 43 is theoretically reduced within a predetermined time according to the current flowing through the oxygen reduction cell, and the concentration decreases from about 21% to about 10%. Was confirmed to have decreased.

  In the refrigerator 41 shown in FIG. 9, as the door 23 (see FIG. 8) is closed, the oxygen reduction device 40 is operated in the closed state of the door 23. Along with this, the oxygen concentration in the oxygen-reducing chamber (that is, the cathode chamber) 43 in which food is stored is reduced, so that corrosion of the food due to oxidation can be suppressed and the storage period of the food can be extended.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof. Some of the elements described in the specification are indicated by element symbols.

  DESCRIPTION OF SYMBOLS 1 ... Electrochemical cell, 2, 2A, 2B ... Electrochemical apparatus, 2C ... Electrochemical apparatus (oxygen reduction apparatus), 4 ... Anode chamber, 5 ... Cathode chamber (oxygen reduction chamber), 6 ... Power supply (voltage application means) DESCRIPTION OF SYMBOLS 10 ... Electrolytic container, 11 ... Anode, 12 ... First surface of anode, 13 ... Second surface of anode, 14 ... First hole, 15 ... Second hole, 16 ... Catalyst layer, T2 The thickness of the region on the first surface side of the anode, T3: The thickness of the region on the second surface side of the anode, 23 ... Door (opening / closing member), 31 ... Cathode, 35 ... Electrolyte membrane, 40 ... Oxygen reduction device, 41 ... refrigerator, 42 ... refrigerator main body, 43 ... hypoxic chamber.

Claims (11)

In an electrochemical cell comprising an anode, a cathode, and an electrolyte membrane sandwiched therebetween,
At least one of the anode and the cathode is formed of an integrally conductive single plate, and is in a thickness direction from the first surface in contact with the electrolyte membrane and the first surface. Having a spaced second surface,
The at least one electrode has a plurality of first holes opened to the first surface, and a plurality of second holes opened to the second surface, and the second A hole is communicated with a portion of the first hole;
The first holes are smaller than the second holes, and the opening density of the first surface is larger than the opening density of the second surface;
Furthermore, the electrochemical cell whose number of said 1st hole is 30 piece / cm < ² > or more. The electrochemical cell according to claim 1, wherein the number of the first holes is 200 / cm ² or more. 3. The electricity according to claim 1, wherein the second hole is formed narrower toward the first hole connected to the second hole and wider toward the second surface. 4. Chemical cell. The electrochemical cell according to any one of claims 1 to 3 , wherein a catalyst layer is formed on the first surface where the plurality of first holes are opened. An electrolytic container that forms an oxygen reduction chamber that is opened and closed by an opening and closing member, and an electrochemical cell according to any one of claims 1 to 4 , wherein the electrochemical cell is attached to the electrolytic container, An oxygen reduction cell for electrolyzing water with the anode provided and reducing oxygen in the oxygen reduction chamber with a cathode provided in the electrochemical cell; and a voltage applying means for applying a voltage to the oxygen reduction cell. Hypoxic device. A refrigerator body having a reduced oxygen chamber, mounted for opening and closing the decrease oxygen chamber to the refrigerator body, a closing member for holding the reduced oxygen chamber closed state to the closed state, according to claim 5 A refrigerator comprising the oxygen reduction device, the oxygen reduction device disposed in the refrigerator body so that a cathode of an oxygen reduction cell included in the device reacts with oxygen in the oxygen reduction chamber. The electrochemical apparatus using the electrochemical cell as described in any one of Claim 1 to 4 . An electrolytic vessel in which the electrochemical cell according to any one of claims 1 to 4 is disposed;
A power source for applying a voltage to the electrochemical cell;
An electrochemical device comprising control means for controlling application of a voltage to the electrochemical cell. 9. The electrochemical device according to claim 8 , wherein the electrolytic vessel is formed with an anode chamber facing the anode of the electrochemical cell and a cathode chamber facing the cathode of the electrochemical cell. The electrochemical device according to any one of claims 7 to 9 , wherein the electrochemical device is for electrolysis. The electrochemical device according to claim 10 , wherein the electrochemical device is for salt electrolysis.