JP2018109217A - Electrochemical hydrogen pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrochemical hydrogen pump capable of reducing contact resistance between an electrolyte membrane (cathode catalyst layer) and a cathode gas diffusion layer with a simple configuration as compared with conventional ones.SOLUTION: The electrochemical hydrogen pump includes: an electrolyte membrane having a pair of main surfaces; a cathode catalyst layer provided on one main surface of the electrolyte membrane; an anode catalyst layer provided on the other main surface of the electrolyte membrane; a cathode gas diffusion layer provided for the cathode catalyst layer; an anode gas diffusion layer provided for the anode catalyst layer; and a voltage applicator for applying a voltage between the cathode catalyst layer and the anode catalyst layer. The cathode gas diffusion layer includes a metal sheet provided with a plurality of vent holes, and a metal fiber sintered sheet. The metal sheet is adjacent to the cathode catalyst layer.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to an electrochemical hydrogen pump.

  In recent years, hydrogen has attracted attention as a clean alternative energy source to replace fossil fuels due to environmental problems such as global warming and energy problems such as the depletion of petroleum resources. Even if hydrogen burns, it basically releases only water, and carbon dioxide that causes global warming is not discharged, and nitrogen oxides are hardly discharged. Further, as a device that uses hydrogen as a fuel with high efficiency, for example, there is a fuel cell, and the development and popularization of a fuel cell are progressing for a power source for automobiles and for private power generation for home use.

  In the coming hydrogen society, in addition to producing hydrogen, there is a need for technological development that can store hydrogen at a high density, and can be transported or used at low cost and at low cost. In particular, in order to promote the spread of fuel cells as a distributed energy source, it is necessary to improve the fuel supply infrastructure. Various proposals for purifying and boosting high-purity hydrogen have been made in order to stably supply hydrogen to the fuel supply infrastructure.

  For example, we propose a high-pressure hydrogen production system that produces high-pressure hydrogen on the cathode side by applying voltage between the anode and cathode provided on the electrolyte membrane and electrolyzing water supplied to the anode side. (For example, refer to Patent Document 1).

  Moreover, even if hydrogen (cathode gas) becomes high pressure, the cathode power supply is pressed against the electrolyte membrane using a disc spring or a coil spring so that the contact resistance between the electrolyte membrane and the cathode power supply is less likely to increase. A pressing means that can be brought into close contact has been proposed (see, for example, Patent Document 2).

  In addition, a configuration has been proposed in which a power supply body for an electrochemical cell includes a metal fiber laminate, and titanium coarse particles are filled between the metal fibers and the metal fiber, and the surface of the power supply body is spread with titanium fine particles (for example, And Patent Document 3). Thereby, the damage of the membrane electrode assembly by a metal fiber is reduced, improving the adhesiveness between a electric power feeding body and a membrane electrode assembly.

JP 2001-342587 A JP 2006-70322 A JP 2002-69681 A

  However, the conventional example has not been sufficiently studied to reduce the contact resistance between the electrolyte membrane and the cathode power supply with a simple configuration, and to reduce damage to the electrolyte membrane.

  One aspect of the present disclosure has been made in view of such circumstances, and the contact resistance between the electrolyte membrane (cathode catalyst layer) and the cathode gas diffusion layer with a simpler configuration than the conventional one. An electrochemical hydrogen pump capable of reducing the above is provided. In addition, an electrochemical hydrogen pump that can reduce damage to an electrolyte membrane as compared with the prior art is provided.

In order to solve the above problems, an electrochemical hydrogen pump according to an aspect of the present disclosure includes an electrolyte membrane including a pair of main surfaces, a cathode catalyst layer provided on one main surface of the electrolyte membrane, and the electrolyte membrane. An anode catalyst layer provided on the other main surface, a cathode gas diffusion layer provided for the cathode catalyst layer, an anode gas diffusion layer provided for the anode catalyst layer,
A voltage applicator for applying a voltage between the cathode catalyst layer and the anode catalyst layer, and the cathode gas diffusion layer includes a metal sheet having a plurality of air holes and a metal fiber sintered sheet, The metal sheet is adjacent to the cathode catalyst layer.

  The electrochemical hydrogen pump according to an aspect of the present disclosure has an effect that the contact resistance between the electrolyte membrane (cathode catalyst layer) and the cathode gas diffusion layer can be reduced with a simple configuration as compared with the conventional one. In addition, the electrochemical hydrogen pump according to one embodiment of the present disclosure has an effect that the damage to the electrolyte membrane can be reduced as compared with the related art.

FIG. 1 is a diagram illustrating an example of an electrochemical hydrogen pump according to the first embodiment. FIG. 2 is a diagram illustrating an example of the electrochemical hydrogen pump according to the first embodiment. FIG. 3 is a diagram illustrating an example of a cathode gas diffusion layer of the electrochemical hydrogen pump according to the first embodiment. FIG. 4 is a diagram illustrating an example of an anode gas diffusion device of the electrochemical hydrogen pump according to the first embodiment. FIG. 5 is a diagram illustrating an example of a fastening operation of a single cell of the electrochemical hydrogen pump according to the first embodiment. FIG. 6 is a diagram illustrating an example of the cathode separator of the electrochemical hydrogen pump according to the second embodiment. FIG. 7 is a diagram illustrating an example of a cathode gas diffusion layer of the electrochemical hydrogen pump according to the third embodiment.

  Also in Patent Document 2, as described above, a configuration for reducing the contact resistance between the electrolyte membrane and the cathode power feeder is being studied. However, a pressing means for pressing the cathode power feeder against the electrolyte membrane is provided. Because it is necessary, the number of parts increases. Therefore, in the high-pressure hydrogen production apparatus of Patent Document 2, an increase in the number of parts may complicate the apparatus configuration and increase production costs.

  Even in Patent Document 3, as described above, a structure for reducing the damage of the membrane electrode assembly due to the metal fiber while improving the adhesion between the power feeding body and the membrane electrode assembly has been studied. In the technique of filling the fiber with the conductive material powder, it is difficult to sufficiently smooth the surface of the power feeding body. The reason is as follows.

  In Patent Document 3, titanium coarse particles are filled between metal fibers and the surface of the power feeding body is filled with titanium fine particles. However, supply of titanium particles is performed so that the surface of the power feeding body is spread only with titanium fine particles. It is difficult to control. If titanium coarse particles are present on the surface of the power feeding body, the surface of the power feeding body is partially uneven due to the titanium coarse particles. Therefore, in the power supply body for an electrochemical cell of Patent Document 3, there is a possibility that the membrane electrode assembly is damaged by the unevenness of the surface of the power supply body.

  Therefore, the electrochemical hydrogen pump according to the first aspect of the present disclosure has been devised based on the above knowledge, and is provided on an electrolyte membrane having a pair of main surfaces and one main surface of the electrolyte membrane. Cathode catalyst layer, an anode catalyst layer provided on the other main surface of the electrolyte membrane, a cathode gas diffusion layer provided for the cathode catalyst layer, and an anode gas diffusion layer provided for the anode catalyst layer And a voltage applicator for applying a voltage between the cathode catalyst layer and the anode catalyst layer, and the cathode gas diffusion layer includes a metal sheet having a plurality of air holes and a metal fiber sintered sheet, Is adjacent to the cathode catalyst layer.

  According to such a configuration, the electrochemical hydrogen pump of this aspect can reduce the contact resistance between the electrolyte membrane (cathode catalyst layer) and the cathode gas diffusion layer with a simpler configuration than the conventional one. Specifically, when the cathode gas of the electrochemical hydrogen pump is in a high pressure state during operation of the electrochemical hydrogen pump, the electrolyte membrane does not pass the cathode gas, so that high pressure is applied to the anode gas diffusion layer, the anode catalyst layer, and the electrolyte membrane. Take it. Then, each of the anode gas diffusion layer, the anode catalyst layer, and the electrolyte membrane is compressed and deformed. At this time, since the metal fiber sintered sheet of the cathode gas diffusion layer is an elastic body, the metal sheet and the electrolyte membrane (cathode catalyst layer) even when the above-described compression deformation occurs due to the elastic force of the metal fiber sintered sheet. Can be kept in proper contact with Therefore, the electrochemical hydrogen pump of this embodiment does not require a dedicated member for pressing the metal sheet against the electrolyte membrane (cathode catalyst layer) as in Patent Document 2, and thus has a simpler configuration than that of Patent Document 2. The contact resistance can be reduced.

  Moreover, the electrochemical hydrogen pump of this aspect can reduce the damage of an electrolyte membrane compared with the past. Specifically, the surface of the metal sheet adjacent to the cathode catalyst layer can be formed more smoothly than the powder layer made of the conductive material powder of Patent Document 3. In other words, as described above, this powder layer may be partially uneven due to titanium coarse particles, but the surface of the metal sheet is compared with the powder layer by precise metal surface treatment. Can be relaxed. Therefore, the electrochemical hydrogen pump of this aspect can reduce damage to the electrolyte membrane as compared with Patent Document 3.

  The electrochemical hydrogen pump according to the second aspect of the present disclosure is the electrochemical hydrogen pump according to the first aspect, wherein the main surface of the metal sheet has a larger area than the main surface of the cathode catalyst layer.

  According to such a configuration, the electrochemical hydrogen pump of this aspect can be configured with the entire main surface of the cathode catalyst layer as an electrical contact surface. Therefore, compared with the case where the area of the main surface of the metal sheet is smaller than the area of the main surface of the cathode catalyst layer, the cathode catalyst layer can be used effectively, so that the hydrogen pressurization property of the electrochemical hydrogen pump can be improved.

  An electrochemical hydrogen pump according to a third aspect of the present disclosure is the electrochemical hydrogen pump according to the first aspect or the second aspect. The separator includes a recess that houses a cathode gas diffusion layer, an electrolyte membrane, a cathode catalyst layer, and an anode. And a fastener for fastening a laminate of a catalyst layer, a cathode gas diffusion layer, an anode gas diffusion layer, and a separator. In this case, in the electrochemical hydrogen pump, the cathode gas diffusion layer is disposed so as to protrude in the thickness direction of the recess before the laminated body is fastened by the fastener, and the metal sheet is equal to or less than the thickness of the metal sheet. Thus, it protrudes in the thickness direction of the recess.

  According to this configuration, in the electrochemical hydrogen pump of this aspect, the cathode gas diffusion layer protrudes from the concave portion of the separator in the thickness direction of the concave portion. Can be compressed. Therefore, even when each of the anode gas diffusion layer, the anode catalyst layer, and the electrolyte membrane is compressed and deformed, the metal fiber sintered sheet is elastically deformed in a direction returning from the thickness after compression by the fastener to the thickness before compression. The contact between the metal sheet and the electrolyte membrane (cathode catalyst layer) can be appropriately maintained.

  In addition, since the metal sheet is equal to or less than the thickness of the metal sheet and protrudes in the thickness direction of the recess, the side surface of the recess functions as a sliding guide for the side surface of the metal sheet. Then, the metal fiber sintered sheet can be smoothly elastically deformed (stretched) in the thickness direction of the recess without the metal fiber sintered sheet protruding from the recess.

  The electrochemical hydrogen pump according to the fourth aspect of the present disclosure is the electrochemical hydrogen pump according to the third aspect, wherein the main surface of the metal sheet has a larger area than the main surface of the metal fiber sintered sheet, and the metal fiber sintered sheet. Is adjacent to the main surface of the metal sheet not adjacent to the cathode catalyst layer.

  The electrochemical hydrogen pump according to the fifth aspect of the present disclosure is the electrochemical hydrogen pump according to the third aspect, wherein the metal sheet has a longer outer circumference than the metal fiber sintered sheet.

  When the metal sheet of the cathode gas diffusion layer and the metal fiber sintered sheet are placed in the recess in the size relationship between the metal sheet and the metal fiber sintered sheet and the arrangement relationship between the two, the side surface of the recess and the metal fiber sintered sheet An appropriate gap can be provided between the side surfaces. Then, when compressing a metal fiber sintered sheet to the thickness direction of a recessed part, the deformation | transformation (elongation) of a metal fiber sintered sheet to a surface direction perpendicular | vertical to this thickness direction is performed appropriately by presence of this clearance gap.

  The electrochemical hydrogen pump according to the sixth aspect of the present disclosure is the electrochemical hydrogen pump according to any one of the first to fifth aspects, wherein leakage of hydrogen flowing through the cathode gas diffusion layer is prevented on the separator around the recess. A sealing structure for sealing is provided.

  According to this configuration, the cathode gas diffusion layer can be appropriately sealed using the main surface of the separator.

  Hereinafter, specific examples of the first embodiment, the second embodiment, and the third embodiment will be described with reference to the accompanying drawings. Each of the specific examples described below shows an example of each of the above aspects. Therefore, the shapes, materials, constituent elements, arrangement positions of the constituent elements, connection forms, and the like shown below do not limit each of the above aspects unless otherwise stated in the claims. In addition, among the following constituent elements, constituent elements that are not described in the independent claims indicating the highest concept of this aspect are described as optional constituent elements. In the drawings, the same reference numerals are sometimes omitted. In addition, the drawings schematically show each component for easy understanding, and there are cases where the shape and dimensional ratio are not accurately displayed.

(First embodiment)
[Device configuration]
1 and 2 are diagrams illustrating an example of the electrochemical hydrogen pump according to the first embodiment. FIG. 2 is an enlarged view of a portion A in FIG.

  As shown in FIGS. 1 and 2, the electrochemical hydrogen pump 100 of the present embodiment includes an electrolyte membrane 14, a cathode catalyst layer 15, an anode catalyst layer 16, an anode gas diffusion device 9, and a voltage applicator 19. The fastener 27, the cathode gas diffusion layer 31, and the cathode separator 32 are provided. The anode gas diffusion device 9 includes an anode body 1 including an anode gas diffusion layer 24, an anode gas flow path plate 5, and an anode end plate 10.

  A single cell 100 </ b> A of the electrochemical hydrogen pump 100 includes an electrolyte membrane 14, a cathode catalyst layer 15, an anode catalyst layer 16, a cathode gas diffusion layer 31, a cathode separator 32, and an anode gas diffusion device 9. Therefore, although the electrochemical hydrogen pump 100 of FIG. 1 constitutes a stack in which three single cells 100A are stacked, the number of single cells 100A is not limited to this. That is, the number of stages of the single cell 100A can be set to an appropriate number based on operating conditions such as the amount of hydrogen of the electrochemical hydrogen pump 100.

  The fastener 27 fastens the laminate 100B of the electrolyte membrane 14, the cathode catalyst layer 15, the anode catalyst layer 16, the cathode gas diffusion layer 31, the anode gas diffusion layer 24, and the cathode separator 32.

  That is, in order to appropriately hold a plurality of unit cells 100A including the above-described stacked body 100B in a stacked state, the end surface of the uppermost cathode separator 32 and the end surface of the anode gas diffusion device 9 in the lowermost layer of the unit cell 100A are provided. It is necessary to apply a desired fastening pressure to the single cell 100A by sandwiching between the end plate 26U and the end plate 26D via an insulating plate (not shown). Therefore, a plurality of fasteners 27 including disc springs or the like for applying a fastening pressure to the single cell 100A are provided at appropriate positions of the end plate 26U and the end plate 26D.

  The fastening device 27 may have any configuration as long as the laminated body 100B can be fastened. Examples of the fastener 27 include a bolt penetrating between the end plate 26U and the end plate 26D, and a nut with a disc spring.

  The end plate 26U is provided with a cathode gas outlet pipe 30 through which the cathode gas from the cathode gas diffusion layer 31 flows. That is, the cathode gas outlet pipe 30 communicates with a cylindrical cathode gas outlet manifold (not shown) provided in the stacked unit cell 100A. A seal member such as an O-ring (not shown) is provided between the cathode separator 32 and the anode gas diffusion device 9 so as to surround the cathode gas lead-out manifold in plan view, and the cathode gas lead-out manifold is the seal member. Properly sealed.

  The end plate 26U is also provided with an anode gas outlet pipe 29 through which excess anode gas from the anode gas diffusion device 9 flows. That is, the anode gas outlet pipe 29 communicates with a cylindrical anode gas outlet manifold 29A provided in the stacked single cell 100A. A seal member 40 such as an O-ring is provided between the cathode separator 32 and the anode gas diffusion device 9 so as to surround the anode gas lead-out manifold 29A in plan view, and the anode gas lead-out manifold 29A is connected to the seal member 40. Is properly sealed.

  The end plate 26D is provided with an anode gas introduction pipe 28 through which the anode gas supplied to the anode gas diffusion device 9 flows. That is, the anode gas introduction pipe 28 communicates with a cylindrical anode gas introduction manifold 28A provided in the stacked single cell 100A. A seal member 40 such as an O-ring is provided between the cathode separator 32 and the anode gas diffusion device 9 so as to surround the anode gas introduction manifold 28A in a plan view, and the anode gas introduction manifold 28A is provided with the seal member 40. Is properly sealed.

The electrolyte membrane 14 includes a pair of main surfaces. The electrolyte membrane 14 is a proton conductive polymer membrane that can transmit protons (H ⁺ ). The electrolyte membrane 14 may be any membrane as long as it is a proton conductive polymer membrane. For example, examples of the electrolyte membrane 14 include a fluorine-based polymer electrolyte membrane. Specifically, for example, Nafion (registered trademark, manufactured by DuPont), Aciplex (trade name, manufactured by Asahi Kasei Co., Ltd.) and the like can be used.

  The cathode catalyst layer 15 is provided on one main surface (for example, the front surface) of the electrolyte membrane 14. In plan view, a sealing member 41 such as an O-ring or a gasket is provided so as to surround the cathode catalyst layer 15, and the cathode catalyst layer 15 is appropriately sealed with the sealing member 41. That is, the electrochemical hydrogen pump 100 of this embodiment seals the leakage of the cathode gas (hydrogen) flowing through the cathode gas diffusion layer 31 on the cathode separator 32 on the outer periphery of the recess 35 (see FIG. 3) of the cathode separator 32. A seal structure is provided. Thus, the cathode catalyst layer 15 and the cathode gas diffusion layer 31 can be appropriately sealed using the main surface of the cathode separator 32. The cathode catalyst layer 15 includes, for example, platinum as a catalyst metal, but is not limited thereto.

  The cathode gas diffusion layer 31 is provided for the cathode catalyst layer 15. The detailed configuration of the cathode gas diffusion layer 31 will be described later.

  The anode catalyst layer 16 is provided on the other main surface (for example, the back surface) of the electrolyte membrane 14. In plan view, a sealing member 42 such as an O-ring or a gasket is provided so as to surround the anode catalyst layer 16, and the anode catalyst layer 16 is appropriately sealed with the sealing member 42. That is, the electrochemical hydrogen pump 100 of this embodiment includes a seal structure that seals leakage of the anode gas flowing through the anode gas diffusion layer 24 on the anode body 1 on the outer periphery of the anode gas diffusion layer 24. Thereby, the anode catalyst layer 16 and the anode gas diffusion layer 24 can be appropriately sealed using the main surface of the anode body 1. The anode catalyst layer 16 includes, for example, RuIrFeOx as a catalyst metal, but is not limited thereto.

  The anode gas diffusion layer 24 of the anode gas diffusion device 9 is provided for the anode catalyst layer 16. The detailed configuration of the anode gas diffusion device 9 will be described later.

  The cathode catalyst layer 15 and the anode catalyst layer 16 are not particularly limited because various methods can be used as a method for preparing the catalyst. For example, examples of the catalyst carrier include conductive porous material powder and carbon-based powder. Examples of the carbon-based powder include powders such as graphite, carbon black, and activated carbon having electrical conductivity. The method for supporting platinum or other catalytic metals on a carrier such as carbon is not particularly limited. For example, a method such as powder mixing or liquid phase mixing may be used. Examples of the latter liquid phase mixing include a method of dispersing and adsorbing a carrier such as carbon in a catalyst component colloid liquid. If necessary, platinum or other catalytic metals can be supported in the same manner as described above using the active oxygen removing material as a carrier. The state of the catalyst metal such as platinum supported on the carrier is not particularly limited. For example, the catalyst metal may be finely divided and supported on the carrier with high dispersion.

  The voltage applicator 19 applies a voltage between the cathode catalyst layer 15 and the anode catalyst layer 16. Specifically, the low potential side terminal of the voltage applicator 19 is connected to the conductive cathode separator 32, and the high potential side terminal of the voltage applicator 19 is connected to the conductive anode gas diffusion device 9. . The voltage applicator 19 may have any configuration as long as a voltage can be applied between the cathode catalyst layer 15 and the anode catalyst layer 16.

[Configuration of cathode gas diffusion layer]
FIG. 3 is a diagram illustrating an example of a cathode gas diffusion layer of the electrochemical hydrogen pump according to the first embodiment. FIG. 3A is a view showing a cross-sectional view of the cathode gas diffusion layer 31 and the cathode separator 32 when the cathode gas diffusion layer 31 is housed in the recess 35 of the cathode separator 32. FIG. 3B is a plan view of the BB part of the metal sheet 31 </ b> A of the cathode gas diffusion layer 31. FIG. 3C is an enlarged view of a boundary region (C portion) between the metal sheet 31A of the cathode gas diffusion layer 31 and the metal fiber sintered sheet 31B. FIG. 3D is a perspective view of the cathode gas diffusion layer 31 from the metal fiber sintered sheet 31B side.

  The cathode gas diffusion layer 31 includes a metal sheet 31A and a metal fiber sintered sheet 31B.

  The metal sheet 31 </ b> A includes a plurality of air holes 31 </ b> AH and is adjacent to the cathode catalyst layer 15. The metal sheet 31A is configured such that portions other than the vent hole 31AH do not have gas permeability. Further, the portion other than the vent hole 31AH has higher rigidity than the metal fiber sintered sheet 31B. For example, the metal sheet 31A may be a metal steel plate having a thickness of about several tens of μm to several hundreds of μm (for example, about 100 μm). In addition, such a metal sheet 31A can be manufactured by performing casting and rolling of a metal, for example. Since the metal casting and rolling processes are known, a detailed description is omitted.

  The main surface of the metal sheet 31 </ b> A has a larger area than the main surface of the cathode catalyst layer 15. Specifically, when the cathode catalyst layer 15 is viewed in plan from the metal sheet 31A, the entire cathode catalyst layer 15 is covered with the metal sheet 31A.

  Thereby, the main surface of the cathode catalyst layer 15 can be configured as an electrical contact surface. Therefore, compared with the case where the area of the main surface of the metal sheet 31 </ b> A is smaller than the area of the main surface of the cathode catalyst layer 15, the cathode catalyst layer 15 can be used effectively, so that the hydrogen pressurization property of the electrochemical hydrogen pump 100 can be improved. .

  Further, the plurality of air holes 31AH of the metal sheet 31A may be formed in a matrix shape (lattice shape) at equal intervals in the vertical and horizontal directions. The vent hole 31AH may be, for example, a round hole having a diameter of about several tens of μm (for example, about 20 μm). The material of the metal sheet 31A may be, for example, stainless steel, titanium, titanium alloy, aluminum alloy, or the like. The diameter of the air hole 31AH may be equal to or smaller than the thickness of the metal fiber 31BF so that the metal fiber 31BF of the metal fiber sintered sheet 31B is difficult to penetrate. The reason is that if the diameter of the vent hole 31AH is made smaller than the thickness of the metal fiber 31BF, the metal fiber 31BF of the metal fiber sintered sheet 31B is prevented from penetrating the vent hole 31AH, and the cathode catalyst layer 15 (electrolyte membrane) This is because the damage 14) may be reduced.

  As described above, the metal sheet 31A has desired rigidity and desired electrical conductivity in portions other than the vent hole 31AH, and desired gas permeability in the vent hole 31AH. In addition, the material and shape of the above metal sheet 31A are illustrations, and are not limited to this example.

  The metal fiber sintered sheet 31B is configured to ensure the elasticity, electrical conductivity, and gas permeability required for the cathode gas diffusion layer 31. As such a metal fiber sintered sheet 31B, for example, a metal fiber sintered body obtained by sintering the metal fiber 31BF into a nonwoven fabric can be used. In the nonwoven fabric-like metal fiber sintered body, the metal fibers 31BF are formed in a tertiary shape, and the contacts of each other are sintered. Therefore, the electrical conductivity of the non-woven metal fiber sintered body is high. Moreover, since metal fiber 31BF is comprised by the tertiary form, it is excellent also in the gas dispersibility of a nonwoven fabric-like metal fiber sintered compact. The material of the metal fiber 31BF may be, for example, stainless steel, titanium, titanium alloy, aluminum alloy, or the like. In addition, the material of this metal fiber 31BF is an illustration, Comprising: It is not limited to this example.

  In the cathode gas diffusion layer 31 described above, the metal sheet 31A and the metal fiber sintered sheet 31B are welded, brazed, welded, or the like in a state where the central axes of the metal sheet 31A and the metal fiber sintered sheet 31B are aligned. They may be joined together by metal bonding. For example, the main surface of the metal sheet 31A and the main surface of the metal fiber sintered sheet 31B may be subjected to surface bonding by diffusion bonding or the like.

  Here, in the electrochemical hydrogen pump 100 of this embodiment, as shown in FIG. 3A, the cathode separator 32 includes a recess 35 in which the cathode gas diffusion layer 31 is accommodated.

  Before the laminate 100B (see FIG. 1) is fastened by the fastener 27, the cathode gas diffusion layer 31 is disposed so as to protrude in the thickness direction of the recess 35, and the metal sheet 31A is the metal sheet 31A. Or less in the thickness direction of the recess 35.

  In plan view, the surface shape of the metal sheet 31 </ b> A is substantially the same as the opening shape of the recess 35, and the surface area of the metal sheet 31 </ b> A is slightly smaller than the opening area of the recess 35. When the metal sheet 31A of the cathode gas diffusion layer 31 is placed in such a recess 35, the metal sheet 31A can smoothly slide relative to the recess 35 between the side surface of the metal sheet 31A and the side surface of the recess 35. Only a certain gap is formed. Therefore, the side surface of the recess 35 functions as a sliding guide with respect to the side surface of the metal sheet 31A. Then, the metal fiber sintered sheet 31 </ b> B can be elastically deformed (stretched) smoothly in the thickness direction of the recess 35 without protruding from the recess 35.

  The protruding amount Ecd in the thickness direction of the metal sheet 31A from the recess 35 takes into account the respective compression amounts of the anode gas diffusion layer 24, the anode catalyst layer 16 and the electrolyte membrane 14 when the electrochemical hydrogen pump 100 is operated. To an appropriate value.

  As shown in FIG. 3D, the main surface of the metal sheet 31A has a larger area than the main surface of the metal fiber sintered sheet 31B, and the metal fiber sintered sheet 31B is a metal that is not adjacent to the cathode catalyst layer 15. Adjacent to the main surface of the sheet 31A. That is, the metal sheet 31A has a longer outer peripheral length than the metal fiber sintered sheet 31B. In this case, the surface area of the metal fiber sintered sheet 31B is smaller than the surface area of the metal sheet 31A in plan view.

  Therefore, when the metal sheet 31A and the metal fiber sintered sheet 31B of the cathode gas diffusion layer 31 are placed in the recess 35 in the above-described size relationship between the metal sheet 31A and the metal fiber sintered sheet 31B and the arrangement relationship therebetween, FIG. As shown in (a), between the side surface of the metal fiber sintered sheet 31B and the side surface of the recess 35, a cylindrical gap S corresponding to the separation distance L1 from the side surface of the recess 35 is a metal fiber sintered sheet 31B. It is formed so as to be along the side surface. Thus, when the metal fiber sintered sheet 31B is compressed in the thickness direction of the recess 35, the deformation (elongation) of the metal fiber sintered sheet 31B in the plane direction perpendicular to the thickness direction is caused by the presence of the gap S. Done properly.

  As shown in FIG. 3A, the cathode separator 32 includes a manifold hole 32C and a cathode gas communication path 32B for sending the cathode gas in the recess 35 to the manifold hole 32C. That is, when the single cells 100A are stacked, a cylindrical cathode gas lead-out manifold is formed by the manifold hole 32A (see FIG. 4) provided in the anode gas diffusion device 9 and the manifold hole 32C. Thereby, the cathode gas in a high pressure state can be taken out from the cathode gas diffusion layer 31 through the cathode gas communication path 32B.

[Configuration of anode gas diffusion device]
FIG. 4 is a diagram illustrating an example of an anode gas diffusion device of the electrochemical hydrogen pump according to the first embodiment. FIG. 4A is a plan view of the anode body 1 of the anode gas diffusion device 9. FIG. 4B is a plan view of the anode gas flow path plate 5 of the anode gas diffusion device 9. FIG. 4C is a plan view of the anode end plate 10 of the anode gas diffusion device 9.

  FIG. 4D is a cross-sectional view of the anode gas diffusion device 9. That is, in FIG. 4D, a cross section of the DD portion of the anode gas diffusion device 9 shown in plan view in FIGS. 4A, 4B, and 4C is shown. .

  As shown in FIG. 4 (d), the anode gas diffusion device 9 includes an anode body 1, an anode gas flow path plate 5, and an anode end plate 10.

  The anode body 1 is a metal member that diffuses anode gas. The anode body 1 may have any configuration as long as it is a metal member that diffuses the anode gas. The anode body 1 may be made of a metal such as stainless steel, titanium, titanium alloy, or aluminum alloy. The thickness of the anode body 1 may be about several hundred μm (for example, about 400 μm). These materials and numerical values are examples and are not limited to this example.

  As shown in FIGS. 4A and 4D, the anode body 1 includes an anode gas diffusion layer 24, a manifold hole 3 for introducing an anode gas, and a manifold hole 4 for extracting an anode gas.

  The anode gas diffusion layer 24 provided in the anode body 1 is configured to be able to diffuse the anode gas using a laminated body of metal plates provided with air holes, a sintered body of porous metal powder, or the like. .

  The anode gas flow path plate 5 is provided on the main surface of the anode body 1. In the anode gas diffusion device 9 of the present embodiment, the anode gas flow path plate 5 is provided so as to be in surface contact with the main surface of the anode body 1.

  As a material of the anode gas flow path plate 5, for example, stainless steel, titanium, titanium alloy, aluminum alloy, or the like can be used. The thickness of the anode gas flow path plate 5 may be about several tens of μm (for example, about 50 μm). These materials and numerical values are examples and are not limited to this example.

  As shown in FIGS. 4B and 4D, the anode gas flow path plate 5 includes a manifold hole 7 for introducing an anode gas, a manifold hole 8 for deriving the anode gas, an anode gas flow path 6, Is provided.

  The manifold hole 7 and the manifold hole 8 are disposed so as to face the manifold hole 3 and the manifold hole 4 of the anode body 1, respectively.

  In the anode gas diffusion device 9 of the present embodiment, the anode gas flow path 6 of the anode gas flow path plate 5 includes a plurality of slit holes 36 that communicate with both the manifold hole 7 and the manifold hole 8. In this case, the manifold hole 7 is used for introducing the anode gas into the anode gas diffusion layer 24 by communicating with one end of the plurality of anode gas flow paths 6. That is, the anode gas that has passed through the contact portion between the slit hole 36 of the anode gas flow path 6 and the anode gas diffusion layer 24 is sent to the anode gas diffusion layer 24. The manifold hole 8 communicates with the other ends of the plurality of anode gas flow paths 6 and is used for derivation of the anode gas from the anode gas diffusion layer 24.

  The anode end plate 10 is provided on a main surface (hereinafter referred to as an opposite surface) that does not face the anode body 1 among the main surfaces of the anode gas flow path plate 5. Specifically, the plurality of slit holes 36 of the anode gas flow path plate 5 are covered with the anode end plate 10 from the opposite surface.

  As a material of the anode end plate 10, for example, stainless steel, titanium, a titanium alloy, an aluminum alloy, or the like can be used. The thickness of the anode end plate 10 may be about several tens of μm (for example, about 50 μm). These materials and numerical values are examples and are not limited to this example.

  Further, the anode end plate 10 includes a manifold hole 11 for introducing an anode gas and a manifold hole 12 for extracting the anode gas. The manifold hole 11 and the manifold hole 12 of the anode end plate 10 are respectively arranged so as to face the manifold hole 7 and the manifold hole 8 of the anode gas flow path plate 5.

  As described above, when the single cells 100 </ b> A are stacked, the anode gas introduction manifold 28 </ b> A is formed by the manifold hole 11, the manifold hole 7, the manifold hole 3, and the manifold hole of the cathode separator 32. An anode gas outlet manifold 29 </ b> A is formed by the manifold hole 12, the manifold hole 8, the manifold hole 4, and the manifold hole of the cathode separator 32.

  In the anode gas diffusion device 9 of the present embodiment, the anode end plate 10, the anode gas flow channel plate 5, and the anode main body 1 may be integrally bonded by metal bonding by welding, brazing, welding, or the like. . For example, the main surface of the anode end plate 10, the main surface of the anode gas flow channel plate 5, and the main surface of the anode body 1 may be surface-bonded by diffusion bonding or the like. Thereby, compared with the case where the anode end plate 10, the anode gas flow path plate 5, and the anode main body 1 are fixed and laminated with a mechanical fastening member, the gap at the joint portion disappears, so the anode gas diffusion device 9 contact resistance (electrical resistance) can be reduced. Then, when applying a desired voltage to the anode gas diffusion device 9, an increase in power consumption required for the electrochemical hydrogen pump 100 can be suppressed.

[Single cell fastening operation by a fastener]
FIG. 5 is a diagram illustrating an example of a fastening operation of a single cell of the electrochemical hydrogen pump according to the first embodiment.

  5 shows members (hereinafter referred to as an electrolyte membrane (with a catalyst layer) with the cathode catalyst layer 15 and the anode catalyst layer 16 applied respectively to the main surfaces of the cathode separator 32, the cathode gas diffusion layer 31, and the electrolyte membrane 14. 14A), the anode gas diffusion layer 24 and the cross section of the anode body 1 are shown.

  First, as shown in FIG. 5A, the cathode gas diffusion layer 31, the electrolyte membrane (with catalyst layer) 14A, and the anode gas diffusion layer 24 are aligned so as to face each other.

  Next, as shown in FIG. 5B, the cathode gas diffusion layer 31, the electrolyte membrane (with catalyst layer) 14A, and the anode gas diffusion layer 24 are laminated. At this time, the metal sheet 31A of the cathode gas diffusion layer 31, the electrolyte membrane (with catalyst layer) 14A and the anode gas diffusion layer 24 are in contact with each other, but since the fastening force by the fastener 27 is not applied, A gap corresponding to the protruding amount Ecd in the thickness direction of the metal sheet 31A of the cathode gas diffusion layer 31 is formed between the main surface and the electrolyte membrane (with catalyst layer) 14A. A cylindrical gap S corresponding to the separation distance L1 from the side surface of the recess 35 is also formed between the side surface of the metal fiber sintered sheet 31B of the cathode gas diffusion layer 31 and the side surface of the recess 35.

  Next, as shown in FIG. 5C, the laminate 100 </ b> B is fastened by the fastener 27. Then, the metal fiber sintered sheet 31B of the cathode gas diffusion layer 31 is compressed by the fastening force of the fastener 27, and the main surface of the metal sheet 31A of the cathode gas diffusion layer 31 and the electrolyte membrane (with catalyst layer) 14A are compressed. The main surface is in close contact with the main surface of the anode gas diffusion layer 24. In this case, the compression amount (thickness) of the metal fiber sintered sheet 31B is equal to the protrusion amount Ecd. That is, since the gap between the main surface of the cathode separator 32 and the electrolyte membrane (with catalyst layer) 14A disappears, the thickness T2 after compression is subtracted from the original thickness T1 before compression of the metal fiber sintered sheet 31B. The value is equal to the protrusion amount Ecd. Further, when the metal fiber sintered sheet 31B is compressed in the thickness direction of the concave portion 35, the metal fiber sintered sheet 31B extends in a plane direction perpendicular to the thickness direction. Therefore, the separation distance L2 from the side surface of the concave portion 35 is: It becomes smaller than said separation distance L1 (that is, L1> L2).

  Thus, the fastening of the single cell 100A of the electrochemical hydrogen pump 100 before the operation of the electrochemical hydrogen pump 100 is completed.

[Operation of electrochemical hydrogen pump]
Hereinafter, an example of the operation (operation) of the electrochemical hydrogen pump 100 of the first embodiment will be described with reference to the drawings.

  Part or all of the following operations may be performed by a control program of a controller (not shown). The controller may have any configuration as long as it has a control function. The controller includes, for example, an arithmetic circuit and a storage circuit that stores a control program. Examples of the arithmetic circuit include an MPU and a CPU. An example of the memory circuit is a memory. The controller may be composed of a single controller that performs centralized control, or may be composed of a plurality of controllers that perform distributed control in cooperation with each other.

  First, a voltage is applied between the cathode separator 32 and the anode gas diffusion device 9 by the voltage applicator 19.

  Next, the anode gas is supplied to the anode gas diffusion device 9 through the anode gas introduction pipe 28. Specifically, the anode gas is supplied from the anode gas introduction pipe 28 to the manifold hole 7 of FIG. Then, since the manifold hole 7 communicates with one end of the anode gas flow path 6 of the anode gas flow path plate 5, gas is sent from the manifold hole 7 to the anode gas flow path 6.

  At this time, a part of the anode gas flowing through the anode gas channel 6 is sent to the anode gas diffusion layer 24 of the anode body 1. Since the anode gas diffusion layer 24 has a gas diffusion action, the anode gas directed from the anode gas flow path 6 to the main surface (hereinafter referred to as the opposite surface) of the anode gas diffusion layer 24 not facing the anode gas flow path plate 5 is generated. The anode gas diffusion layer 24 can pass through the opposite surface while being uniformly diffused. As a result, the anode gas is uniformly supplied to the anode catalyst layer 16 disposed on the opposite surface of the anode gas diffusion layer 24. The surplus anode gas that has not passed through the opposite surface is sent to the manifold hole 8 communicating with the other end of the anode gas passage 6 of the anode gas passage plate 5 and discharged to the anode gas outlet pipe 29. The Examples of the anode gas include a hydrogen-containing reformed gas and a hydrogen-containing gas generated by a water electrolysis method.

Thus, hydrogen in the anode gas releases electrons on the anode catalyst layer 16 to become protons (H ⁺ ) (formula (1)). The liberated electrons move to the cathode catalyst layer 15 via the voltage applicator 19.

  On the other hand, protons permeate the electrolyte membrane 14 with water molecules and move to the cathode catalyst layer 15. In the cathode catalyst layer 15, a reduction reaction is performed by protons that have permeated through the electrolyte membrane 14 and electrons, and cathode gas (hydrogen gas) is generated (formula (2)).

As a result, the hydrogen gas is purified with high efficiency from the hydrogen gas (anode gas) containing impurities such as CO ₂ gas. The anode gas sometimes contains CO gas as an impurity. In this case, since CO gas reduces the catalytic activity of the anode catalyst layer 16 and the like, it is better to remove the CO gas by a CO remover (not shown) (for example, a converter, a CO selective oxidizer, etc.).

  The cathode gas pressure P2 is increased by increasing the pressure loss of the cathode gas outlet pipe 30 and increasing the voltage E of the voltage applicator 19. Specifically, the relationship among the anode gas pressure P1, the cathode gas pressure P2, and the voltage E of the voltage applicator 19 is formulated by the following equation (3).

Anode: H ₂ (low pressure) → 2H ⁺ + 2e ⁻ (1)
Cathode: 2H ⁺ + 2e ⁻ → H ₂ (high pressure) (2)
E = (RT / 2F) ln (P2 / P1) + ir (3)
In the formula (3), R is a gas constant (8.3145 J / K · mol), T is a temperature (K), F is a Faraday constant (96485 C / mol), P2 is a cathode gas pressure, and P1 is an anode gas pressure. , I is the current density (A / cm ² ), and r is the cell resistance (Ω · cm ² ).

  From equation (3), it can be easily understood that the cathode gas pressure P2 can be increased by increasing the voltage E of the voltage applicator 19. Note that the pressure loss of the cathode gas outlet pipe 30 can be increased or decreased by, for example, the opening degree of an on-off valve provided in the cathode gas outlet pipe 30.

  When the gas pressure in the cathode gas diffusion layer 31 becomes equal to or higher than a predetermined pressure, the cathode loss of the cathode gas diffusion layer 31 is reduced by reducing the pressure loss of the cathode gas outlet pipe 30 (for example, by increasing the opening of the on-off valve). The gas is charged into a high-pressure hydrogen tank (not shown) through the cathode gas outlet pipe 30. On the other hand, when the gas pressure of the cathode gas diffusion layer 31 becomes less than a predetermined pressure, the cathode gas diffusion layer 31 and the high pressure are increased by increasing the pressure loss of the cathode gas outlet pipe 30 (for example, by reducing the opening of the on-off valve). The hydrogen tank is shut off. As a result, the cathode gas in the high-pressure hydrogen tank is prevented from flowing back to the cathode gas diffusion layer 31.

  Thus, the electrochemical hydrogen pump 100 boosts the high purity cathode gas (hydrogen gas) to a desired target pressure and fills the high pressure hydrogen tank.

  In the cathode gas pressure increasing operation described above, the cathode gas pressure P2 becomes high, and the electrolyte membrane 14, the anode catalyst layer 16, and the anode gas diffusion layer 24 are pressed. Then, the electrolyte membrane 14, the anode catalyst layer 16, and the anode gas diffusion layer 24 are compressed by this pressing. At this time, if the adhesion between the cathode catalyst layer 15 and the cathode gas diffusion layer 31 is low, a gap is likely to be generated between them. If there is a gap between the cathode catalyst layer 15 and the cathode gas diffusion layer 31, the contact resistance between them increases. As a result, the voltage E applied by the voltage applicator 19 increases, which may reduce the operation efficiency of the electrochemical hydrogen pump 100.

  Therefore, in the electrochemical hydrogen pump 100 of the present embodiment, the cathode gas diffusion layer 31 is disposed in the thickness direction from the concave portion 35 of the cathode separator 32 as shown in FIG. 3 before the stacked body 100B is fastened by the fastener 27. In addition, it is configured to protrude by the amount of protrusion Εcd. Further, the metal fiber sintered sheet 31B of the cathode gas diffusion layer 31 is compressed by an amount of protrusion Εcd by the fastener 27 as shown in FIG. 5C when the laminated body 100B is fastened.

  As described above, in the electrochemical hydrogen pump 100 of the present embodiment, the contact resistance between the electrolyte membrane 14 and the cathode gas diffusion layer 31 can be reduced with a simpler configuration than the conventional one. Specifically, when the cathode gas of the electrochemical hydrogen pump 100 is in a high pressure state during operation of the electrochemical hydrogen pump 100, the electrolyte membrane 14 does not pass the cathode gas, so that the anode gas diffusion layer 24, the anode catalyst layer 16 and High pressure is applied to the electrolyte membrane 14. Then, each of the anode gas diffusion layer 24, the anode catalyst layer 16, and the electrolyte membrane 14 is compressed and deformed. At this time, since the metal fiber sintered sheet 31B of the cathode gas diffusion layer 31 is an elastic body, even when the above-described compression deformation occurs due to the elastic force of the metal fiber sintered sheet 31B, the metal sheet 31A and the electrolyte membrane 14 are used. The contact with the (cathode catalyst layer 15) can be appropriately maintained.

  Specifically, since the cathode gas diffusion layer 31 protrudes from the recess 35 of the cathode separator 32 in the thickness direction of the recess 35, the metal fiber sintered sheet 31 </ b> B is connected by the fastener 27 by the amount of protrusion Ecd of the cathode gas diffusion layer 31. Can be compressed. Therefore, even when each of the anode gas diffusion layer 24, the anode catalyst layer 16, and the electrolyte membrane 14 is compressed and deformed, the metal fiber sintered sheet 31B returns from the thickness compressed by the fastener 27 to the thickness before compression. By elastically deforming, the contact between the metal sheet 31A and the electrolyte membrane 14 (cathode catalyst layer 15) can be appropriately maintained. Therefore, the electrochemical hydrogen pump 100 according to the present embodiment does not require a dedicated member for pressing the metal sheet 31A against the electrolyte membrane (cathode catalyst layer) as in Patent Document 2, and thus is simpler than that of Patent Document 2. The contact resistance can be reduced with a simple configuration.

  Moreover, the electrochemical hydrogen pump 100 of this embodiment can reduce the damage of the electrolyte membrane 14 compared with the past.

  Specifically, in Patent Document 3, titanium coarse particles are filled between metal fibers and the surface of the power feeding body is filled with titanium fine particles, but the surface of the power feeding body is spread only with titanium fine particles. It is difficult to control the supply of titanium particles. If titanium coarse particles are present on the surface of the power feeding body, the surface of the power feeding body is partially uneven due to the titanium coarse particles. Therefore, in the power supply body for an electrochemical cell of Patent Document 3, there is a possibility that the membrane electrode assembly is damaged by the unevenness of the surface of the power supply body. In contrast, the unevenness of the surface of the metal sheet 31A can be reduced as compared with the powder layer by a precise metal surface treatment. Therefore, the electrochemical hydrogen pump 100 of the present embodiment can reduce damage to the electrolyte membrane 14 as compared with Patent Document 3.

(Second Embodiment)
FIG. 6 is a diagram illustrating an example of the cathode separator of the electrochemical hydrogen pump according to the second embodiment.

  The electrochemical hydrogen pump 100 according to this embodiment is the electrochemical hydrogen pump 100 according to any one of the first to fifth aspects. The recess 135 of the cathode separator 132 is opened more than the area of the main surface of the metal sheet 31A. A first recess 135A having a large area and a second recess 135B having an opening area smaller than the area of the main surface of the metal sheet 31A are provided.

  That is, in plan view, the opening area of the first recess 135A is larger than the surface area of the metal sheet 31A. In addition, when viewed from the side, the opening depth Ecg1 of the first recess 135A (the amount of step from the main surface of the cathode separator 132) is smaller than the thickness Ect of the metal sheet 31A.

  The opening of the second recess 135B is formed coaxially with the opening of the first recess 135A in plan view. The opening area of the second recess 135B is larger than the surface area of the metal fiber sintered sheet 31B and smaller than the surface area of the metal sheet 31A. In addition, when viewed from the side, the opening depth Ecg2 of the second recess 135B (the step amount from the bottom surface of the first recess 135A) is smaller than the thickness of the metal fiber sintered sheet 31B.

  When the metal sheet 31 </ b> A and the metal fiber sintered sheet 31 </ b> B of the cathode gas diffusion layer 31 are placed in such a recess 135, before the laminate 100 </ b> B (see FIG. 1) is fastened by the fastener 27, the cathode gas diffusion layer 31. Is disposed so as to protrude in the thickness direction of the recess 135, and the metal sheet 31A protrudes in the thickness direction of the recess 135 below the thickness Ect of the metal sheet 31A. The protruding amount Ecd in the thickness direction of the metal sheet 31A from the recess 135 is the sum of the value obtained by subtracting the opening depth Ecg2 of the second recess 135B from the thickness of the metal fiber sintered sheet 31B and the thickness Ect of the metal sheet 31A. , The difference between the opening depth Ecg1 of the first recess 135A. Thereby, the protrusion amount Ecd can be set appropriately. The protruding amount Ecd is set to an appropriate value in consideration of the respective compression amounts of the anode gas diffusion layer 24, the anode catalyst layer 16, and the electrolyte membrane 14 when the electrochemical hydrogen pump 100 is operated.

  Further, between the side surface of the metal fiber sintered sheet 31B and the side surface of the second recess 135B, a cylindrical gap S corresponding to the separation distance L3 from the side surface of the second recess 135B is present in the metal fiber sintered sheet 31B. It is formed along the side.

  As described above, in the electrochemical hydrogen pump 100 of this embodiment, since the cathode gas diffusion layer 31 protrudes from the recess 135 of the cathode separator 132 in the thickness direction of the recess 135, the cathode gas diffusion layer 31 protrudes by the amount Ecd of the protrusion. The metal fiber sintered sheet 31B can be compressed by the container 27. Therefore, even when each of the anode gas diffusion layer 24, the anode catalyst layer 16, and the electrolyte membrane 14 is compressed and deformed, the metal fiber sintered sheet 31B returns from the thickness compressed by the fastener 27 to the thickness before compression. By elastically deforming, the contact between the metal sheet 31A and the electrolyte membrane 14 (cathode catalyst layer 15) can be appropriately maintained.

  Further, when the laminated body 100B is fastened by the fastener 27, the main surface of the metal sheet 31A and the bottom surface of the first recess 135A are in surface contact, and therefore electrical conductivity can be secured even in this contact portion. The applied voltage of the voltage applicator 19 can be reduced.

  Further, the accuracy of the dimension (for example, the diameter of the opening) of the first recess 135A does not need to be higher than the dimensional accuracy of the recess 35 of the first embodiment (FIG. 3). Therefore, the manufacturing cost of the cathode separator 132 can be reduced.

  The electrochemical hydrogen pump 100 of the present embodiment may be the same as the electrochemical hydrogen pump 100 of the first embodiment except for the above features.

(Third embodiment)
FIG. 7 is a diagram illustrating an example of a cathode gas diffusion layer of the electrochemical hydrogen pump according to the third embodiment. FIG. 7 shows an enlarged cross-sectional view of the boundary region between the metal sheet 131A of the cathode gas diffusion layer 131 and the metal fiber sintered sheet 31B.

  The electrochemical hydrogen pump 100 according to the present embodiment is the same as the electrochemical hydrogen pump 100 according to any one of the first aspect-fifth aspect and the second embodiment, wherein the vent hole 131AH of the metal sheet 131A of the cathode gas diffusion layer 131 is The opening area of the opening on the main surface side adjacent to the metal fiber sintered sheet 31B is smaller than the opening area of the opening on the other main surface side. For example, the vent hole 131AH may be a tapered hole extending in a direction from the main surface side adjacent to the metal fiber sintered sheet 31B toward the other main surface side.

  Here, when the air hole 131AH of the metal sheet 131A is formed by, for example, laser or etching, the air hole 131AH is not a straight hole but is often a tapered hole. Specifically, the opening area of the opening portion of the vent hole 131AH of the metal sheet 131A on the laser beam incident side and the etching mask arrangement side tends to be larger than the opening area of the other opening portion.

  Therefore, in the electrochemical hydrogen pump 100 of the present embodiment, the main surface of the metal sheet 131A having a small opening area of the opening portion of the vent hole 131AH is adjacent to the metal fiber sintered sheet 31B.

  As a result, compared to the case where the metal sheet 131A is disposed in the reverse direction, the metal fibers of the metal fiber sintered sheet 31B are less likely to penetrate the vent holes 131AH, and the cathode catalyst layer 15 (electrolyte membrane 14) is damaged. The possibility can be reduced.

  The electrochemical hydrogen pump 100 of the present embodiment may be the same as the electrochemical hydrogen pump 100 of the first embodiment or the second embodiment except for the above features.

  Note that the first embodiment, the second embodiment, and the third embodiment may be combined with each other as long as they do not exclude each other.

  In addition, many modifications and other embodiments of the disclosure are apparent to those skilled in the art from the foregoing description. Accordingly, the foregoing description is to be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the disclosure. Details of the structure and / or function may be substantially changed without departing from the spirit of the present disclosure.

  One aspect of the present disclosure can be used for an electrochemical hydrogen pump that can reduce the contact resistance between the electrolyte membrane (cathode catalyst layer) and the cathode gas diffusion layer with a simple configuration as compared with the related art.

1: Anode body 3: Manifold hole 4: Manifold hole 5: Anode gas flow path plate 6: Anode gas flow path 7: Manifold hole 8: Manifold hole 9: Anode gas diffusion device 10: Anode end plate 11: Manifold hole 12: Manifold hole 14: Electrolyte membrane 15: Cathode catalyst layer 16: Anode catalyst layer 19: Voltage applicator 24: Anode gas diffusion layer 26D: End plate 26U: End plate 27: Fastener 28: Anode gas introduction pipe 28A: Anode gas introduction Manifold 29: Anode gas outlet pipe 29A: Anode gas outlet manifold 30: Cathode gas outlet pipe 31: Cathode gas diffusion layer 31A: Metal sheet 31AH: Ventilation hole 31B: Metal fiber sintered sheet 31BF: Metal fiber 32: Cathode separator 32A: Manifold hole 32B: cathode gas Communication path 32C: Manifold hole 35: Recess 36: Slit hole 40: Seal member 41: Seal member 42: Seal member 100: Electrochemical hydrogen pump 100A: Single cell 100B: Laminate 131: Cathode gas diffusion layer 131A: Metal sheet 131AH : Vent 132: Cathode separator 135: Recess 135A: First recess 135B: Second recess

Claims (9)

An electrolyte membrane comprising a pair of main surfaces;
A cathode catalyst layer provided on one main surface of the electrolyte membrane;
An anode catalyst layer provided on the other main surface of the electrolyte membrane;
A cathode gas diffusion layer provided for the cathode catalyst layer;
An anode gas diffusion layer provided for the anode catalyst layer;
A voltage applicator for applying a voltage between the cathode catalyst layer and the anode catalyst layer,
The cathode gas diffusion layer includes a metal sheet having a plurality of ventilation holes and a metal fiber sintered sheet, and the metal sheet is an electrochemical hydrogen pump adjacent to the cathode catalyst layer.   The electrochemical hydrogen pump according to claim 1, wherein a main surface of the metal sheet has a larger area than a main surface of the cathode catalyst layer. A separator having a recess for accommodating the cathode gas diffusion layer;
The electrolyte membrane, the cathode catalyst layer, the anode catalyst layer, the cathode gas diffusion layer,
A fastener for fastening the laminate of the anode gas diffusion layer and the separator,
Before the laminate is fastened by the fastener, the cathode gas diffusion layer is disposed so as to protrude in the thickness direction of the recess,
3. The electrochemical hydrogen pump according to claim 1, wherein the metal sheet protrudes in a thickness direction of the concave portion less than a thickness of the metal sheet.   The main surface of the metal sheet has a larger area than the main surface of the metal fiber sintered sheet, and the metal fiber sintered sheet is adjacent to the main surface of the metal sheet that is not adjacent to the cathode catalyst layer. The electrochemical hydrogen pump according to claim 3.   The electrochemical hydrogen pump according to claim 3, wherein the metal sheet has a longer outer circumference than the metal fiber sintered sheet.   The said recessed part is equipped with the 1st recessed part with an opening area larger than the area of the main surface of the said metal sheet, and the 2nd recessed part with an opening area smaller than the area of the main surface of the said metal sheet. Electrochemical hydrogen pump.   The electrochemical hydrogen pump according to any one of claims 1 to 6, further comprising a seal structure that seals leakage of hydrogen flowing through the cathode gas diffusion layer on the separator on the outer periphery of the recess.   The ventilation hole of the metal sheet is any one of claims 1-7, wherein an opening area of an opening portion on a main surface side adjacent to the metal fiber sintered sheet is smaller than an opening area of an opening portion on the other main surface side. 2. The electrochemical hydrogen pump according to item 1. A separator having a recess for accommodating the cathode gas diffusion layer;
The electrochemical system according to claim 1, further comprising: a fastener that fastens a laminate of the electrolyte membrane, the cathode catalyst layer, the anode catalyst layer, the cathode gas diffusion layer, the anode gas diffusion layer, and the separator. Hydrogen pump.

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