Electrochemical cell stack and gas adsorption device

Abstract

To provide an electrochemical cell stack which has a compact constitution and which can improve an output per physique, and to provide a gas adsorption device.SOLUTION: In an electrochemical cell stack (1) in which a plurality of single layer cells (C) including a frame member (3) for supporting an electrochemical cell (2) is laminated, between the single layer cells (C) adjacent to each other in the lamination direction (X), a gas flow passage (11) is partitioned and formed. The electrochemical cell (2) causes an electrochemical reaction by a gas (G) being introduced to action electrodes (21) arranged oppositely from each other from the gas flow passage (11), and a voltage being applied between counter electrodes (22). The frame member (3) includes a power collection plate part (31), a rib part (32), and a plurality of support leg parts (33) protruding from the power collection plate part (31) and positioned in the gas flow passage (11). In the support leg part (33), a protruding end part (331) is electrically connected to the action electrode (21) of the adjacent single layer cell (C).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electrochemical cell stack and a gas adsorption device. [Background technology]

[0002] Conventionally, electrochemical cell stacks have been used in gas adsorption devices for separating specific gas species contained in mixed gases. The electrochemical cell stack has a structure in which electrochemical cells are stacked, and the gas adsorption device is configured to adsorb and separate specific gas species from the mixed gas introduced to the electrodes of each cell by applying a predetermined voltage to each cell of the electrochemical cell stack.

[0003] For example, Patent Document 1 discloses a carbon dioxide capture system that includes a CO2 capture device using an electrochemical cell and captures CO2 from a CO2-containing gas in a CO2 capture mode. In this system, the electrochemical cell has a working electrode containing a CO2 adsorbent and a counter electrode, and as a voltage for CO2 capture is applied between the two electrodes, the CO2 adsorbent is reduced and bonds with CO2. When the mode is switched from the CO2 capture mode to the CO2 release mode, CO2 is desorbed from the CO2 adsorbent and sent to a CO2 storage tank or a CO2 utilization device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-44999 A Summary of the Invention [Problem to be solved by the invention]

[0005] The CO2 capture device in Patent Document 1 is configured as an electrochemical cell stack in which multiple single-layer cells are stacked. The single-layer cell is configured such that an electrochemical cell including a working electrode and a counter electrode is arranged on a cell frame, and the cell frame made of a resin molded product forms a gas flow path through which a CO2-containing gas flows while insulating adjacent cells.

[0006] Voltage is applied to the electrochemical cell stack, for example, by providing bus bars for power supply at both ends in the stacking direction and connecting them to an external power source. In this case, it is necessary to electrically connect each layer in series by drawing out tab terminals from the current collectors in contact with the working electrode and counter electrode of each layer and connecting them to the tab terminals on the working electrode side or counter electrode side of the adjacent layer.

[0007] On the other hand, in order to improve the CO2 capture output per unit size of the CO2 capture device, it is desirable to configure the electrochemical cell stack more compactly. However, in the conventional structure, as mentioned above, it is necessary to pull out tab terminals for electrical connection between layers, which limits the reduction in the number of parts and the size of the device. In addition, if the electrode area increases with the required output, measures such as thickening will be required to ensure the strength of the cell frame made of molded resin, which may hinder the miniaturization.

[0008] The present invention has been made in view of the above problems, and has an object to provide an electrochemical cell stack and a gas adsorption device that have a compact configuration and are capable of improving output per unit size. [Means for solving the problem]

[0009] One aspect of the present invention is an electrochemical cell stack (1) in which a plurality of single-layer cells (C) each including an electrochemical cell (2) having a working electrode (21) and a counter electrode (22) arranged opposite each other and a frame member (3) supporting the electrochemical cell are stacked in a direction in which the working electrode and the counter electrode face each other, A gas flow path (11) is defined between the single-layer cells adjacent to each other in the stacking direction (X), In the electrochemical cell, a gas (G) is introduced from the gas flow channel to the working electrode, and a voltage is applied between the working electrode and the counter electrode to cause an electrochemical reaction; the frame member has a conductive current collector portion (31) arranged in contact with the counter electrode, a rib portion (32) arranged along an outer peripheral edge portion of the current collector portion and surrounding the outside of the electrochemical cell, and a plurality of conductive support legs (33) protruding from the current collector portion to a side opposite the counter electrode and positioned within the gas flow path, The support legs are in an electrochemical cell stack with protruding ends (331) electrically connected to the working electrodes of the adjacent monolayer cells.

[0010] Another aspect of the present invention is a gas adsorption device (100) including an electrochemical cell stack having the configuration of the above aspect, a pair of bus bars (41, 42) disposed at both ends of the electrochemical cell stack in a stacking direction (X), and a power source (B) connected to the pair of bus bars, The electrochemical cell is in a gas adsorption device configured to include an adsorbent in the working electrode capable of adsorbing a specific gas contained in the gas introduced from the gas flow path, and to adsorb the specific gas into the adsorbent as electrons are supplied from the counter electrode side to the working electrode side by applying a voltage supplied from the power source via the pair of bus bars between the working electrode and the counter electrode. Effect of the Invention

[0011] In the electrochemical cell stack having the above-mentioned configuration, the frame member has a current collector plate portion arranged to abut against the counter electrode and a plurality of conductive support legs, and the protruding ends of the support legs are arranged to abut against the adjacent working electrodes, thereby enabling direct electrical connection with adjacent single-layer cells. This forms a conductive path that electrically connects two adjacent single-layer cells in series. In addition, the electrochemical cell of each single-layer cell is held inside the rib portion by the rib portion along the outer periphery of the current collector plate portion.

[0012] This eliminates the need to pull out tab terminals and the like outside the frame member as in the conventional method, and reduces the number of parts. In addition, since the current collector plate can be made of a metal plate, there is no need to increase the thickness of the electrode due to an increase in the electrode area, as in the case of using a conventional resin product. As a result, the configuration of the electrochemical cell stack can be made compact, and the output per unit size can be improved. When a gas adsorption device is configured with such an electrochemical cell stack, a predetermined voltage is applied between the working electrode and the counter electrode of the electrochemical cell, and electrons can be exchanged through the conductive path formed between the single-layer cells. Then, as electrons are supplied from the counter electrode, the specific gas introduced from the gas flow path can be efficiently adsorbed by the adsorbent contained in the working electrode.

[0013] As described above, according to the above aspects, it is possible to provide an electrochemical cell stack and a gas adsorption device that have a compact configuration and can improve the output per unit size. In addition, the symbols in parentheses described in the claims and the means for solving the problems indicate a correspondence with the specific means described in the embodiments described below, and do not limit the technical scope of the present invention. [Brief description of the drawings]

[0014] [Figure 1] FIG. 3 is a schematic cross-sectional view showing a schematic configuration of an electrochemical cell stack in the first embodiment, and is a cross-sectional view taken along line II in FIG. 2. [Diagram 2] FIG. 1 is a perspective view showing the configuration of a gas adsorption device to which an electrochemical cell stack is applied in a first embodiment. [Diagram 3] FIG. 2 is a perspective view showing a joining structure of frame members that constitute the electrochemical cell stack in the first embodiment. [Figure 4] 1 is an enlarged schematic cross-sectional view showing a main part of an electrochemical cell stack in accordance with Embodiment 1. FIG. [Diagram 5] 4 is an enlarged cross-sectional view of a main portion of the electrochemical cell stack showing a modified example of the frame member in the first embodiment. FIG. [Figure 6]FIG. 11 is a schematic cross-sectional view showing a schematic configuration of an electrochemical cell stack in a comparative embodiment. [Figure 7] 3A to 3C are schematic cross-sectional views comparing conductive paths of electrochemical cell stacks in the first embodiment and a comparative embodiment. [Figure 8] FIG. 2 is a schematic perspective view showing an electrochemical reaction occurring in an electrochemical cell in the first embodiment. [Figure 9] FIG. 1 is a block diagram showing a configuration of a carbon dioxide capture system including a gas adsorption device in a first embodiment. [Figure 10] FIG. 11 is an enlarged schematic cross-sectional view showing a main part of an electrochemical cell stack in a second embodiment. [Figure 11] 10 is an enlarged cross-sectional view of a main portion of an electrochemical cell stack showing a modified example of a frame member in the second embodiment. FIG. [Figure 12] 10 is a schematic cross-sectional view showing the relationship between the load and stress applied to a single-layer cell of an electrochemical cell stack in accordance with Embodiment 2. FIG. [Figure 13] FIG. 11 is a plan view showing the configuration of a frame member in a third embodiment. [Figure 14] FIG. 11 is a cross-sectional view showing a layered structure of an electrochemical cell stack in a third embodiment. [Figure 15] FIG. 11 is an enlarged cross-sectional view of a main portion of an electrochemical cell stack in a third embodiment. [Figure 16] 13A and 13B are a cross-sectional view and a view taken along the arrow A, showing the configuration of a frame member in a fourth embodiment. [Figure 17] FIG. 13 is a perspective view showing a modified example of the frame member in the fourth embodiment. [Figure 18] FIG. 13 is a perspective view showing a layered structure of a modified example of the frame member in the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] (Embodiment 1) An embodiment of an electrochemical cell stack and a gas adsorption device will be described with reference to the drawings. As shown in Fig. 1 and Fig. 2, an electrochemical cell stack 1 is a laminated structure in which a plurality of single-layer cells C are stacked, and hereinafter, the stacking direction (i.e., the vertical direction in the drawings) is referred to as the X-direction. In Fig. 1, each single-layer cell C is composed of an electrochemical cell 2 having a working electrode 21 and a counter electrode 22, and a current collecting frame 3 as a frame member. The current collecting frame 3 supports the electrochemical cell 2. A space that becomes a gas flow path 11 is formed between the single-layer cells C adjacent to each other in the X-direction. The working electrode 21 and the counter electrode 22 are arranged opposite each other, and the single-layer cells C are stacked in the opposing direction.

[0016] In the electrochemical cell 2, an electrochemical reaction occurs when the gas G is introduced from the gas flow path 11 to the working electrode 21 and a voltage is applied between the working electrode 21 and the counter electrode 22. In this embodiment, the working electrode 21 is composed of a working electrode-side current collector 211 and a working electrode-side electrode film 212. In FIG. 2, the electrochemical cell stack 1 is connected to an external power source B, so that a desired voltage can be applied to the electrochemical cell 2. Note that FIG. 1 is a schematic diagram showing a part of a cross section taken along line II in FIG. 2, in which the flow direction of the gas G in the gas flow path 11 is the Y direction (i.e., the direction from the front of the paper to the back of the paper), and the direction perpendicular to the Y direction (i.e., the width direction of the gas flow path 11) is the Z direction.

[0017] As shown in FIG. 1 and FIG. 3, the current collecting frame 3 has a conductive current collecting plate part 31, a support leg part 33, and a rib part 32. The current collecting plate part 31 is disposed in contact with the counter electrode 22 and functions as a current collector on the counter electrode side. The rib part 32 is disposed along the outer periphery of the current collecting plate part 31 and surrounds the outside of the electrochemical cell 2. A plurality of conductive support legs 33 protrude from the surface of the current collecting plate part 31 opposite to the counter electrode 22 and are located in the gas flow path 11. It is desirable that at least a part of the rib part 32 is made of an insulating material so that insulation between the single-layer cells C is maintained. Here, the rib part 32 is configured as a whole integral insulating member. In that case, the rib part 32 is disposed so as to be in close contact with the outer periphery of the electrochemical cell 2 disposed inside (for example, see FIG. 1), thereby ensuring insulation inside the cell. Specifically, the counter electrode 22 has an outer shape smaller than that of the current collecting plate portion 31, and a part of the inner peripheral wall of the rib portion 32 facing the outer periphery of the counter electrode 22 protrudes inward to fill the gap.

[0018] 4, the multiple support legs 33, specifically, have their respective protruding ends 331 in contact with and electrically connected to the working electrodes 21 of the single-layer cells C adjacent to each other in the X direction. This forms a conductive path that electrically connects in series two single-layer cells C adjacent to each other across the gas flow path 11. That is, the current collector plate 31 in contact with the counter electrode 22 of one single-layer cell C and the working electrode 21 of the other single-layer cell C are directly and electrically connected to each other via the multiple support legs 33 held between the two single-layer cells C.

[0019] Specifically, the current collecting plate portion 31 is in contact with the counter electrode 22 to support the entire portion, is made of a rectangular conductive plate material that is impermeable to gas and liquid, forms a current collecting path on the counter electrode 22 side, and separates the counter electrode 22 from the gas flow path 11. In addition, the insulating rib portion 32 rises toward the counter electrode 22 along the outer periphery of the current collecting plate portion 31, and forms a space inside thereof for housing and holding the electrochemical cell 2.

[0020] In this embodiment, the rib portion 32 is a rectangular frame-shaped resin member disposed outside the current collector plate portion 31 and joined to its outer periphery. The height (i.e., the length in the X direction) of the rib portion 32 is equal to or greater than the height of the single-layer cell C, and is adapted to insulate the current collector plate portion 31 and the entire side of the electrochemical cell 2. Preferably, the end of the rib portion 32 on the working electrode side extends to a position where it abuts against the current collector frame 3 of the adjacent single-layer cell C, except for the portion where the gas flow path 11 opens. This makes it possible to suppress gas leakage to the outside and improve the gas sealability between the adjacent single-layer cells C. Specific examples of the shapes of the rib portion 32 and the support leg portion 33 constituting the current collector frame 3 will be described later.

[0021] The current collecting frame 3 configured as described above can maintain insulation between the electrodes of the electrochemical cell 2 by the insulating rib portion 32, while allowing the conductive current collecting plate portion 31 to function as a current collecting plate on the counter electrode 22 side. In addition, the multiple support legs 33 integral with the current collecting plate portion 31 can form a conductive path that directly connects two adjacent single-layer cells C, eliminating the need for connection by a tab terminal as in the past.

[0022] For example, as shown in a modified example in FIG. 5, if an insulating distance from the electrochemical cell 2 can be ensured, a part of the rib portion 32 may be made of metal. In that case, it is sufficient that at least the end of the rib portion 32 facing the frame member 3 of the adjacent single-layer cell C is made of an insulating material. Here, an insulating treatment such as a resin coating is applied to the end face of a rectangular frame-shaped metal member 320 to form a rectangular frame-shaped insulating layer 321. This ensures insulation between two adjacent single-layer cells C even when they are close to each other, and improves gas sealing properties.

[0023] 6 shows an electrochemical cell stack 1 using a resin cell frame 10 as a comparative embodiment. In the case of this comparative electrochemical cell stack 1, the cell frame 10 is configured in a container shape having a plate-like portion on which the electrochemical cell 2 is placed and a rib portion rising from the outer periphery of the plate-like portion, and the entire electrochemical cell 2 is housed inside the cell frame. A plurality of resin support legs 10a are provided integrally on the lower surface of the plate-like portion of the cell frame 10. In this case, the counter electrode-side current collector 20 of the electrochemical cell 2 is disposed in contact with the lower surface of the counter electrode 22.

[0024] 7, in the comparative embodiment, it is necessary to laterally pull out the tab terminals 201 and 202 from the counter electrode side current collector 20 and the working electrode side current collector 211, respectively, and electrically connect them to the adjacent tab terminals 201 and 202. This increases the number of parts and tends to increase the size.

[0025] In FIG. 7, solid arrows indicate conductive paths in an electrochemical cell stack 1 (right diagram) using a conventional resin cell frame 10, in comparison with an electrochemical cell stack 1 (left diagram) of this embodiment. Also, dotted arrows indicate the flow of gas G introduced from a gas flow path 11. The dotted lines in the figure indicate the outer shape of the conventional configuration. In the conventional configuration, adjacent cells are connected via tab terminals 201, 202 to transmit electrons (e - ) moves, increasing the number of parts and lengthening the conductive paths.

[0026] In contrast, in the configuration of this embodiment, the number of parts is reduced and the size is smaller than the conventional configuration because it is not necessary to pull out the conventional tab terminals 201, 202. In Fig. 7, for ease of comparison, the rib portion 32 in the current collecting frame 3 of this embodiment and the portion corresponding to the rib portion in the conventional cell frame 10 are not shown.

[0027] This makes it possible to reduce the number of parts that make up the electrochemical cell stack 1 and to configure a device including the electrochemical cell stack 1 in a compact manner, thereby improving the output per unit size.

[0028] In this embodiment, the electrochemical cell stack 1 having such a configuration is applied to a gas adsorption device and used to adsorb and separate a specific gas species (hereinafter, appropriately referred to as a specific gas) from the gas G flowing through the gas flow passage 11. An example of the specific gas is a gas such as carbon dioxide (CO2), and the CO2 is separated and captured by an electrochemical reaction from a CO2-containing gas as the gas G. The carbon dioxide capture device 100 as the gas adsorption device will be described in detail below.

[0029] 2, the carbon dioxide capture device 100 includes an electrochemical cell stack 1 in which a plurality of single-layer cells C are stacked, a pair of bus bars 41, 42 provided in the electrochemical cell stack 1, and a power source B connected to the pair of bus bars 41, 42. In the electrochemical cell stack 1, a pair of support plates 12, 13 are disposed at both ends in the X direction. The pair of bus bars 41, 42 are fixed to the pair of support plates 12, 13, for example, protrude in the same direction parallel to the plate surfaces, and face each other in the X direction.

[0030] The pair of support plates 12, 13 are rectangular flat plates, and a predetermined number of stacked single-layer cells C are sandwiched between support plate 12, which serves as a top plate, and support plate 13, which serves as a bottom plate. The single-layer cells C are sequentially placed on the upper surface of support plate 13 so that the support legs 33 of the current collecting frame 3 are on the lower side. Support columns 14 are arranged at the four corners between the lower surface of support plate 12 and the upper surface of support plate 13, and the stacking height of the single-layer cells C is set by the height of these support columns 14, and a predetermined load is applied by fastening bolts (not shown) from the support plate 12 side.

[0031] Of the pair of bus bars 41, 42, the bus bar 41 on the support plate 12 side is connected to the negative terminal of a power source B, and the bus bar 42 on the support plate 13 side is connected to the positive terminal of the power source B, forming an electric circuit including a plurality of single-layer cells C connected in series. The electrochemical cell 2 is connected such that the working electrode 21 serves as the negative electrode and the counter electrode 22 serves as the positive electrode, and an oxidation-reduction reaction occurs when electrical energy is supplied. The support plates 12, 13 and the support columns 14 can be made of, for example, metal or resin.

[0032] The electrochemical cell stack 1 may be entirely housed in a chamber (not shown) and connected to a gas inlet and a gas outlet, so that gas G supplied to the gas flow path 11 can be introduced into the electrochemical cell stack 1 and discharged after CO2 is separated from the CO2-containing gas. The electrochemical cell stack 1 has gas flow paths 11 opening at both ends facing each other in a direction perpendicular to the X direction, and by connecting one of the gas flow paths to the gas inlet and the other to the gas outlet, the gas G flows, for example, in the Y direction in the figure.

[0033] The CO2-containing gas introduced into the carbon dioxide capture device 100 is, for example, the atmosphere or an exhaust gas discharged from a factory or the like, and is a mixed gas containing oxygen, nitrogen, and the like in addition to CO2. As shown in FIG. 8, when a CO2-containing gas, which is gas G, is introduced into a single-layer cell C constituting an electrochemical cell stack 1 and a predetermined voltage is applied between both electrodes of the electrochemical cell 2 from a power source B, electrons (e - ) is generated, and electrons (e - ) is supplied. As a result, the CO2 adsorbent contained in the working electrode 21 becomes in a reduced state and combines with the CO2, thereby capturing the CO2. The CO2-excluded gas from which the CO2 has been removed is discharged to the outside of the electrochemical cell stack 1.

[0034] 1, the electrochemical cell 2 specifically includes a working electrode 21, a counter electrode 22, and a separator 23 disposed between them, each of which is formed in a plate shape. The working electrode 21, which is the negative electrode side, includes a working electrode side current collector 211 facing the gas flow channel 11, and a working electrode side electrode film 212 containing a CO2 adsorbent. The counter electrode 22 is an electrode film that pairs with the working electrode side electrode film 212, and is disposed in close contact with a current collector plate portion 31 of a current collector frame 3, which is the positive electrode side current collector.

[0035] The current collecting frame 3 includes a current collecting plate portion 31, a rib portion 32, and a support leg portion 33, and is configured as a frame member that supports the electrochemical cell 2 and also functions as a current collecting plate on the counter electrode side. The current collecting plate portion 31 has a first surface 311 on which the electrochemical cell 2 is placed, and a second surface 312 opposite to the first surface 311. The first surface 311 abuts against the counter electrode 22, and the second surface 312 faces the gas flow path 11.

[0036] The support leg 33 is provided on the second surface 312 of the current collecting plate portion 31 and protrudes in the X direction. The protruding end 331 of the support leg 33 crosses the gas flow passage 11 and is held between the lower single layer cell C located at the opposing position. The arrangement and shape of the support leg 33 can be set arbitrarily. It is preferable to form the support leg 33 so as not to interfere with the gas flow in the gas flow passage 11, to contact the working electrode 21 of the lower single layer cell C to establish electrical connection between adjacent cells, and to enable application of a predetermined cell load.

[0037] Specifically, as shown in Fig. 1 and Fig. 3, the support legs 33 may be plate-shaped bodies of a certain thickness and arranged in parallel to the gas flow at multiple locations on the second surface 312. The number and arrangement of the support legs 33 are appropriately set according to, for example, the size of the electrochemical cell 2, and may be a pair of support legs 33 (see Fig. 1, for example), or three or more support legs 33 may be arranged at a predetermined interval (see Fig. 3, for example). The rectangular support legs 33 may also be arranged in a staggered pattern. By intentionally disturbing the gas flow, such as in the staggered arrangement, the inside of the gas flow channel 11 becomes a turbulent flow region. This improves gas diffusivity and increases the efficiency of CO2 adsorption to the working electrode 21.

[0038] The current collecting frame 3 can be formed by integrally molding the current collecting plate portion 31, on which the support legs 33 are provided in advance, and the rib portion 32, for example, by resin insert molding (see, for example, FIG. 3). Here, the support leg portion 33 is a single plate-like body that extends from one end side to the other end side of the current collecting plate portion 31 in the Y direction, but multiple plate-like bodies may be used and multiple support legs 33 may be arranged in a row at multiple locations on the same straight line in the Y direction.

[0039] 4, the support leg 33 may be formed as a protrusion having a trapezoidal cross section tapered toward a flat surface that becomes the protruding end 331. In this case, it is desirable that the support leg 33 is evenly disposed over the entire second surface 312 of the current collecting plate 31 so that a load is evenly applied to the lower single layer cell C with which the protruding end 331 contacts.

[0040] The material for the conductive current collecting plate 31 and the supporting leg 33 is preferably a metal material that has low electrical resistance and is resistant to elution and corrosion when a voltage is applied, such as Al, SUS, Ni, Cu, Pt, Au, etc. A substrate that has been formed or processed into a predetermined shape and has its surface plated or coated with a material that is resistant to corrosion may also be used.

[0041] The rib portion 32 is disposed outside the current collecting plate portion 31, and a part of an inner peripheral wall portion of the rib portion 32 is joined to an outer peripheral side portion which is a surface 310 connecting a first surface 311 and a second surface 312. That is, the lower surface of the rib portion 32 is at the same position as the second surface 312 of the current collecting plate portion 31, and the upper surface of the rib portion 32 protrudes upward from the first surface 311 to form a wall portion surrounding the space in which the electrochemical cell 2 is housed. The rib portion 32 has a rectangular shape that follows the outer shape of the current collecting plate portion 31, and in order to ensure close contact with each side of the rectangle, the four sides may be divided into two to four members and joined.

[0042] A current collecting frame 3 configured in this way is advantageous when the electrode size is large, and the metal member is prevented from becoming large because the outer periphery is configured with the rib portion 32. In addition, since strict dimensional accuracy is not required for joining the rib portion 32, which is a resin member, to the metal member, and end surface processing of the joint portion is not required, production is relatively easy.

[0043] The resin material constituting the rib portion 32 is preferably one that has weather resistance according to the usage environment, processability according to the molded shape, and the like, and is not easily dissolved in the material that contacts the rib portion 32, for example, the electrolyte solution used as the electrolyte material 24 described below. Examples of such resin materials include polypropylene (PP), polyphenylene sulfide (PPS), polyvinyl chloride resin (PVC), polycarbonate (PC), polyethylene terephthalate (PETP), etc.

[0044] In FIG. 4, the protruding end 331 of the support leg 33 abuts against the working electrode side current collector 211 constituting the working electrode 21 of the lower single-layer cell C. In addition, when the working electrode side electrode film 212 has a current collecting function, the working electrode 21 may not have the working electrode side current collector 211. In that case, the protruding end 331 of the support leg 33 can be configured to directly contact the working electrode side electrode film 212. Alternatively, a conductive member separate from the working electrode 21 may be interposed, and it is sufficient that the support leg 33 and the working electrode 21 are configured to be electrically connectable. In addition, the length of the support leg 33 (i.e., the length from the second surface 312 to the protruding end 331) is preferably longer than the length of the rib portion 32 (i.e., the length of the upper side portion and the lower side portion of the rib portion 32) minus the electrode portion thickness (i.e., the sum of the thicknesses of the electrochemical cell 2 and the current collector plate portion 31). The length of the support leg 33 can be set to be smaller than the thickness of the electrode portion, thereby ensuring a structure in which the support leg 33 is in close contact with the working electrode 21.

[0045] The working electrode side current collector 211 is a porous body made of a conductive material, and is configured to be permeable to the CO2-containing gas flowing through the gas flow passage 11, using, for example, a carbonaceous material or a metallic material. The carbonaceous material is, for example, carbon paper, carbon cloth, a nonwoven carbon mat, a porous gas diffusion layer (GDL), etc., and the metallic material can be, for example, a mesh-like structure using a metal such as Al, Ni, Ti, or SUS.

[0046] The working electrode side electrode film 212 is a mixture film containing a CO2 adsorbent, a working electrode side conductive assistant, and a working electrode side binder. The working electrode side electrode film 212 is attached to the lower surface side of the working electrode side current collector 211, and adsorbs and desorbs CO2 from the introduced CO2-containing gas by an electrochemical reaction.

[0047] The CO2 adsorbent adsorbs CO2 by receiving electrons supplied via the working electrode side current collector 211, and releases the electrons to desorb the adsorbed CO2. The CO2 adsorbent may be any material capable of donating and receiving electrons, and may be, for example, an organic compound such as an organic polymer, an inorganic compound such as a metal oxide, or a porous material such as a carbon material. The organic polymer has a functional group that donates and receives electrons to become an adsorption site for CO2, and may be, for example, polyanthraquinone.

[0048] The working electrode-side conductive assistant is used by mixing with the CO2 adsorbent. The working electrode-side conductive assistant is a conductive material that forms a conductive path in the working electrode-side electrode film 212, and assists the transfer of electrons from the working electrode-side current collector 211 to the CO2 adsorbent. As the working electrode-side conductive assistant, for example, a carbon material such as carbon nanotube, carbon black, graphene, etc. can be used.

[0049] The CO2 adsorbent and the working electrode side conductive assistant may be mixed, for example, by dissolving or dispersing the working electrode side conductive assistant in an organic solvent such as NMP (N-methylpyrrolidone) and contacting the working electrode side conductive assistant dispersed in the organic solvent with the CO2 adsorbent.

[0050] The working electrode side binder is a conductive binder material having adhesive power, and can be used as a mixture of a CO2 adsorbent and a working electrode side conductive assistant. As a result, the CO2 adsorbent and the working electrode side conductive assistant are adhered to the working electrode side current collector 211 while being held by the working electrode side binder, and are therefore less likely to peel off from the working electrode side current collector 211. In addition, the transfer of electrons between the working electrode side current collector 211 and the CO2 adsorbent and the working electrode side conductive assistant is ensured, thereby suppressing a decrease in the amount of CO2 adsorption over time. A non-fluid substance that does not have fluidity can be used as the working electrode side binder.

[0051] As the non-fluid substance, a gel-like substance or a solid-like substance can be used. As the gel-like substance, for example, an ionic liquid gel can be used, and as the solid-like substance, for example, a solid electrolyte or a conductive resin can be used. When using a solid electrolyte, it is desirable to use an ionomer made of a polymer electrolyte or the like in order to increase the contact area with the CO2 adsorbent. When using a conductive resin, an epoxy resin containing Ag or the like as a conductive filler, a fluororesin such as polytetrafluoroethylene (PTFE) or polyvinylidene fluoride (PVDF) can be used.

[0052] The counter electrode 22 is made of a mixture containing a counter electrode side active material, a counter electrode side conductive assistant, and a counter electrode side binder, and is configured as a counter electrode side electrode film that transfers electrons between the working electrode side electrode film 212. The counter electrode side active material is a material that can transfer electrons by changing the valence of the metal or by transferring charges to and from the π electron cloud, and is a supplementary electroactive species that transfers electrons between the working electrode side electrode film 212 and the CO2 adsorbent. As the counter electrode side active material, for example, a metal complex that can transfer electrons by changing the valence of the metal ion can be used. Examples of such metal complexes include cyclopentadienyl metal complexes such as ferrocene, nickelocene, and cobaltocene, and porphyrin metal complexes.

[0053] The counter electrode conductive assistant is a conductive material that is used by mixing with the counter electrode active material and forms a conductive path to the counter electrode active material. The counter electrode conductive assistant may be the same material as the working electrode conductive assistant, or may be a different material.

[0054] The counter electrode side binder is a conductive binder material having adhesive strength, and can be used as a mixture of the counter electrode side active material and the counter electrode side conductive assistant. This allows the counter electrode side active material and the counter electrode side conductive assistant to be held in the counter electrode side binder, and the mixture that becomes the counter electrode side electrode film to be held in close contact with the upper surface of the current collector plate part 31 of the current collector frame 3. This prevents the current collector plate part 31 from peeling off, and ensures the movement of electrons between the current collector plate part 31 and the counter electrode side active material and the counter electrode side conductive assistant. The counter electrode side binder may be made of the same material as the working electrode side binder, or may be made of a different material.

[0055] The separator 23 is disposed between the working electrode 21 and the counter electrode 22. The separator 23 separates the working electrode 21 and the counter electrode 22, and prevents physical contact between the working electrode-side electrode film 212 of the working electrode 21 and the counter electrode-side electrode film of the counter electrode 22. In addition, the separator 23 suppresses electrical short-circuiting between the working electrode-side electrode film 212 and the counter electrode-side electrode film.

[0056] 4, the working electrode 21 and the counter electrode 22 have the same size, and the separator 23 is formed larger than the working electrode 21 and the counter electrode 22. That is, the outer periphery of the separator 23 is located outside the working electrode 21 and the counter electrode 22 and abuts against the inner periphery wall of the rib portion 32.

[0057] The separator 23 may be made of a cellulose film, a polymer, a composite material of polymer and ceramic, etc. The separator 23 may be made of a porous material.

[0058] 4, an electrolyte material 24 having ion conductivity may be provided in the space between the inner peripheral wall portion of the rib portion 32 and the electrochemical cell 2, from the working electrode 21 to the counter electrode 22. The electrolyte material 24 is provided from the working electrode 21 side to the counter electrode 22 side via the separator 23. The electrolyte material 24 promotes electrical conduction to the CO2 adsorbent, and the ions contained in the electrolyte material 24 do not directly react with the CO2 adsorption sites of the CO2 adsorbent.

[0059] The electrolyte material 24 may be, for example, an electrolytic solution or a solid electrolyte. An ionic liquid may be used as the electrolyte. The ionic liquid is a liquid salt that is non-volatile at room temperature and normal pressure. When an ionic liquid is used as the electrolyte material 24, the ionic liquid may be gelled. When a solid electrolyte is used, it is desirable to use an ionomer made of a polymer electrolyte or the like in order to increase the contact area with the CO2 adsorbent.

[0060] The electrochemical cell stack 1 using the single-layer cell C having the configuration of this embodiment allows the carbon dioxide capture device 100 to be configured compactly, and the CO2 capture output per unit size to be improved. In addition, although the configuration shown in Fig. 4 is such that the electrolyte material 24 is also filled in the space outside the counter electrode 22, it may be configured such that the resin rib portion 32 fills the space between the counter electrode 22 as shown in Fig. 1. In that case, it is advantageous for ensuring insulation inside the cell and preventing leakage of the electrolyte solution used as the electrolyte material 24.

[0061] 9, the carbon dioxide capture device 100 can constitute a part of a carbon dioxide capture system S. In this system, a control device 101 can switch between a CO2 capture mode in which the carbon dioxide capture device 100 captures CO2 and a CO2 release mode in which the carbon dioxide capture device 100 releases CO2.

[0062] In the CO2 capture mode, the pump 102 operates to supply gas G, which is a CO2-containing gas, to the carbon dioxide capture device 100, and the flow path switching valve 103 is switched to the atmosphere side. Also, a first voltage for CO2 capture is applied between the two electrodes of the electrochemical cell 2, causing CO2 to be adsorbed by the CO2 adsorbent of the working electrode 21. The flow path switching valve 103 releases the CO2-excluded gas into the atmosphere.

[0063] In the CO2 release mode, the flow path switching valve 103 is switched to the CO2 utilization device 104 side, and the voltage applied between the electrodes of the electrochemical cell 2 is set to a second voltage lower than the first voltage in the CO2 capture mode. This allows CO2 to be desorbed from the CO2 adsorbent and sent from the flow path switching valve 103 to the CO2 utilization device 104. The CO2 utilization device 104 is a storage tank that stores CO2, a device that converts CO2 into hydrocarbon fuel, or the like.

[0064] In this embodiment, a configuration example in which the rib portion 32 of the current collecting frame 3 is joined to the periphery of the metal current collecting plate portion 31 has been shown, but other configurations are also possible. Also, the configuration and shape of the metal members including the current collecting plate portion 31 and the support leg portion 33 can be changed. These configuration examples will be described next.

[0065] (Embodiment 2) Another embodiment of the electrochemical cell stack 1 constituting the gas adsorption device will be described. As shown in Fig. 10, in this embodiment, the joining structure of the rib portion 32 of the current collecting frame 3 is different from that of the above-mentioned embodiment 1. The basic configurations of the electrochemical cell stack 1 including the current collecting frame 3 and the gas adsorption device are similar to those of the above-mentioned embodiment 1, and therefore description thereof will be omitted. In addition, among the symbols used in the second and subsequent embodiments, the same symbols as those used in the previous embodiments represent the same components, etc. as those in the previous embodiments, unless otherwise specified.

[0066] 10, the current collecting frame 3 has a rectangular current collecting plate portion 31, a rectangular frame-like rib portion 32 arranged on the outer periphery of a first surface 311 of the current collecting plate portion 31, and a support leg portion 33 provided integrally with the second surface 312 side of the current collecting plate portion 31. The materials of the conductive current collecting plate portion 31 and the support leg portion 33 and the material of the resin rib portion 32 can be the same as those in the first embodiment.

[0067] The rib portion 32 is a resin member joined along the outer periphery of the current collector plate portion 31 on the first surface 311 of the current collector plate portion 31. That is, the lower surface of the rib portion 32 located on the lower side in the X direction is at the same position as the first surface 311 of the current collector plate portion 31, and the upper surface of the rib portion 32 located on the upper side in the X direction protrudes upward from the first surface 311 to form a wall portion that houses the electrochemical cell 2 inside the rib portion 32. The upper surface of the rib portion 32 abuts against the lower surface of the opposing current collector plate portion 31 to provide a gas seal between the adjacent single-layer cells C. The inner peripheral wall portion of the rib portion 32 is located at a position abutting against the outer periphery of the separator 23 of the electrochemical cell 2, and is disposed at a distance from the outer periphery of the working electrode 21 and the counter electrode 22, which have a smaller outer shape than the separator 23.

[0068] Even in such a configuration, it is possible to prevent short circuits between electrodes and retain the electrolyte by arranging the resin rib portion 32 around the electrochemical cell 2 in the single-layer cell C. In addition, it is possible to ensure insulation between adjacent single-layer cells C on the outside of the current collector plate portion 31 and the support leg portion that form the conductive path to the adjacent electrochemical cell 2, thereby improving the gas sealing performance.

[0069] A current collecting frame 3 configured in this manner is advantageous when the electrode size is small, and since the rib portion 32, which is a resin member, is joined to the upper surface of the metal member, the strength is improved. In addition, positioning is easy, and the rib portion 32 can be joined without dividing it into multiple members. Furthermore, by performing end surface treatment of the rib portion 32 that is joined to the metal member, the adhesion of the joint can be further improved.

[0070] Therefore, the configuration and manufacturing method of the current collecting frame 3 can be appropriately selected depending on the electrode size and manufacturing cost of the electrochemical cell 2. Note that the shape of the support legs 33 of the current collecting frame 3 is a protrusion with a trapezoidal cross section, but is not limited to the shape shown in the figure, and may be a plate-like body with a constant thickness as described above.

[0071] 11, the support leg 33 may be formed in a protrusion shape with a semicircular cross section. In this way, the protruding end 331 becomes spherical, which makes it easier to contact the working electrode 21 of the underlying single-layer cell C. Also, the shape of the support leg 33 is not limited to a semicircular shape, and the cross section of the support leg 33 may be a part of a circle or an ellipse, the protruding end 331 being spherical, or a cylindrical or prismatic protrusion.

[0072] As shown in FIG. 12, in a configuration in which two single-layer cells C are stacked, the upper support leg 33 comes into contact with the lower electrochemical cell 2, and thus a stress is applied to the upper single-layer cell C due to its own weight and the load required to maintain the film adhesion (the stress distribution line is shown by a dashed line in the figure). At this time, depending on the thickness or strength of the electrode film of the working electrode 21 and the counter electrode 22 and the separator 23, material damage or short circuit may occur. Therefore, it is desirable to appropriately set the shape of the support leg 33, the distance between the support legs 33, etc., according to the film configuration of the electrochemical cell 2. In addition, when processing the protruding end 331 of the support leg 33, finishing treatment such as chamfering and deburring is performed to reduce the surface roughness, thereby suppressing material damage and the like.

[0073] (Embodiment 3) Another embodiment of the electrochemical cell stack 1 constituting the gas adsorption device will be described. As shown in Fig. 13 and Fig. 14, in this embodiment, the structure of the support legs 33 of the current collecting frame 3 is different from that of the above-mentioned embodiment 1. The basic configurations of the electrochemical cell stack 1 including the current collecting frame 3 and the gas adsorption device are similar to those of the above-mentioned embodiment 1, and the following description will focus on the differences.

[0074] 14, the structure of the electrochemical cell stack 1 in which a plurality of single-layer cells C are stacked is similar to that of the above-described embodiment 1, and a predetermined number of stacked single-layer cells C are sandwiched between a pair of support plates 12, 13. The current collecting frame 3 constituting the single-layer cells C supports the electrochemical cells 2 and has a large number of support legs 33 protruding from the second surface 312 of the current collecting plate portion 31 to form conductive paths between adjacent single-layer cells C.

[0075] The electrochemical cells 2 supported on the current collecting frame 3 may have the same configuration as in the above-described embodiment 1. In this embodiment, the electrochemical cells 2 are not shown in the drawings in order to mainly show the stacked structure of the current collecting frame 3.

[0076] Here, the current collecting plate part 31 is a rectangular metal plate of a constant thickness and is roughly square in shape, with through holes 313 at the four corners through which the support posts 14 are inserted. The electrochemical cell 2, the outline of which is indicated by a dotted line in Fig. 13 (see the upper diagram), is square in shape with an outer shape smaller than that of the current collecting plate part 31, and is disposed on the first surface 311 inward of the support posts 14.

[0077] 13 (see the lower diagram) and 15, the support legs 33 are metal members having a leaf spring structure, which are integrally provided by being joined to the second surface 312 side of the current collecting plate part 31. The support legs 33 are evenly arranged on the second surface 312 within a range inside the outline of the electrochemical cell 2 on the first surface 311, so as to form a plurality of rows in each of the Y direction and the direction perpendicular to the Y direction.

[0078] The multiple support legs 33 are evenly arranged over the entire surface of the current collecting plate 31. The number and arrangement of the support legs 33 are not particularly limited, but are desirably set so as not to impede the flow of gas G flowing in one direction through the gas flow passage 11 and to ensure a predetermined flow rate. For example, when the Y direction in the figure is the gas flow direction, the support legs 33 are aligned and arranged so that the plate width direction is the Y direction, in other words, the plate thickness direction is perpendicular to the Y direction, thereby preventing the gas flow from colliding with the plate surface.

[0079] 15, a part of the laminated structure is enlarged and shown, the support leg 33 protrudes downward in the X direction from the second surface 312, and the protruding end 331 is in elastic contact with the lower electrochemical cell 2 (not shown). This allows electrical conduction between the current collector plate 31 in contact with the upper electrochemical cell 2 and the lower electrochemical cell 2 via the support leg 33, and electrons emitted to the current collector plate 31 can be supplied to the working electrode side current collector 211 of the working electrode 21 with which the support leg 33 abuts. That is, a conductive path is formed as indicated by the dashed arrow in the figure.

[0080] The support leg 33 can be formed, for example, by bending a strip-shaped metal plate into a substantial Z-shape. The support leg 33 has an upper side portion and a lower side portion parallel to the current collector plate portion 31 and an inclined side portion connecting the upper side portion and the lower side portion, and the upper side portion is joined and fixed to the second surface 312 of the current collector plate portion 31. By stacking the unit cells C, the lower side portion which becomes the protruding end portion 331 is in close contact with the working electrode 21 of the electrochemical cell 2 which faces the current collector plate portion 31 across the gas flow path 11.

[0081] The leaf spring structure of the support leg 33 can be appropriately set so that the unit cells C are stacked to apply a required load to the electrochemical cell 2, a conductive path that connects adjacent electrochemical cells 2 in series is formed, and a required current density distribution is obtained. For example, the distance d1 between the upper side and the lower side of the support leg 33 corresponds to the flow path height H (i.e., the length in the X direction) of the gas flow path 11, and is set to be equal to or slightly larger than a predetermined set height. As a result, when the support leg 33 is sandwiched between the current collector plate 31, which is the upper and lower walls of the gas flow path 11, and the working electrode side current collector 211, the gas flow path 11 is formed to have a predetermined set height, and a load can be applied while securing the conductive path.

[0082] The sizes of the upper and lower sides of the support leg 33 can be set, for example, so that the length of the lower side is smaller than the length of the upper side (i.e., the length in the direction perpendicular to the X direction shown in Fig. 15). This ensures a bonding area between the upper side and the current collecting plate 31, while making it easier for the lower side to come into close contact with the working electrode side current collector 211, contributing to uniformity of the load.

[0083] According to this embodiment, since the support legs 33 have a leaf spring structure, a stable electron supply path between adjacent cells is formed via the multiple support legs 33, a conduction path is ensured, and the variation in load is suppressed, making it possible to apply a uniform load across the surface of the electrochemical cell 2.

[0084] In this embodiment, the shape of the support leg 33 is not limited to the Z-shape, and may be a leaf spring or a coil spring of another shape. The support leg 33 may have any shape as long as it has spring elasticity and is held between adjacent cells, and the same effect can be obtained by having a spring structure.

[0085] (Embodiment 4) 16, in this embodiment, a specific configuration example of the current collecting frame 3 shown in the above-mentioned embodiment 1 will be described. The basic configurations of the electrochemical cell stack 1 including the current collecting frame 3 and the gas adsorption device are similar to those of the above-mentioned embodiment 1, and therefore the description will be omitted.

[0086] 16, the current collecting frame 3 has a current collecting plate portion 31, a rib portion 32 (not shown) joined to a first surface 311 of the current collecting plate portion 31, and a plurality of supporting legs 33 provided integrally on a second surface 312 side of the current collecting plate portion 31. The supporting legs 33 are plate-like members of a constant thickness arranged parallel to each other at a plurality of positions on the second surface 312 in a direction perpendicular to the Y direction, and are arranged from one end side to the other end side in the Y direction of the second surface 312 which is the gas flow direction.

[0087] The current collecting plate portion 31 is, for example, a rectangular metal plate of a predetermined thickness, and the support leg portion 33 can be configured of a thin, elongated metal plate thinner than the current collecting plate portion 31. The support leg portion 33 can be joined and fixed by spot welding or the like so that the angle θ between the support leg portion 33 and the plate surface of the current collecting plate portion 31 is, for example, 90 degrees.

[0088] As shown as a modified example in Fig. 17, the current collecting plate part 31 and the supporting leg part 33 can be formed as an integrally molded product of the same shape by pressing a plate material. In this case, the current collecting plate part 31 and the supporting leg part 33 can be formed by pressing a metal plate material of an appropriate thickness so as to make valley folds and mountain folds at predetermined positions to form the bent parts that become the supporting leg part 33 (see the upper diagram in Fig. 17).

[0089] As shown in the lower diagram of Fig. 17, it is desirable that the bent portions that become the support legs 33 are butted against each other so that there is no gap G (see the upper diagram of Fig. 17) from the tip side that becomes the protruding end 331 to the base side. The current collecting plate portion 31 becomes a flat single plate by the base end sides of the bent portions that become the support legs 33 being tightly attached to each other, and a plurality of support legs 33 that protrude in the X direction from predetermined positions are integrally formed. The current collecting frame 3 is formed by joining a frame-shaped rib portion 32 (not shown) so as to surround the outer periphery of such a current collecting plate portion 31.

[0090] When forming the electrochemical cell stack 1 by stacking the current collecting frames 3 formed by pressing, it is desirable to arrange the positions of the multiple support legs 33 provided on the current collecting plate portion 31 so as to be shifted from the positions of the single layer cells C adjacent to each other in the X direction. For example, as shown in FIG. 18, the positions of the support legs 33 of the upper single layer cell C can be arranged alternately so as to be between the multiple support legs 33 of the lower layer. By stacking the single layer cells C in this way so that the positions of the support legs 33 in the X direction are different, as described above, it is possible to suppress a decrease in adhesion of the bent portion due to the stress (see FIG. 12, for example) applied from the protruding end portion 331 of the support leg 33 to the single layer cell C of the lower layer being concentrated on the base end side of the support leg 33 located directly below.

[0091] According to this embodiment, the metal material used for the current collecting frame 3 of the electrochemical cell stack 1 can be selected according to its workability, required characteristics, etc., and processed into a desired shape using an appropriate processing method. By using the current collecting frame 3 of this embodiment, a conductive path that directly connects the single-layer cells C of the electrochemical cell stack 1 can also be formed, making it possible to configure the carbon dioxide capture device 100 compact and improving the CO2 capture output per unit size.

[0092] In the above embodiment, an example in which the electrochemical cell stack 1 is applied to the carbon dioxide capture device 100 and further to the carbon dioxide capture system S has been described, but the present invention can be applied not only to carbon dioxide capture but also to any gas adsorption device for adsorbing a specific gas contained in a mixed gas. In addition, the system configuration including the gas adsorption device can be appropriately changed. Alternatively, the present invention can be used not only in a gas adsorption device but also in a device having a similar structure in which single-layer cells are stacked and which generates an electrochemical reaction by applying a voltage.

[0093] The present invention is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the spirit and scope of the present invention. In addition, the contents described in the embodiments can be combined. The features of the present invention are as follows. [1] An electrochemical cell stack (1) in which a plurality of single-layer cells (C) each including an electrochemical cell (2) having a working electrode (21) and a counter electrode (22) arranged opposite each other and a frame member (3) supporting the electrochemical cell are stacked in a direction in which the working electrode and the counter electrode face each other, A gas flow path (11) is defined between the single-layer cells adjacent to each other in the stacking direction (X), In the electrochemical cell, a gas (G) is introduced from the gas flow channel to the working electrode, and a voltage is applied between the working electrode and the counter electrode to cause an electrochemical reaction; the frame member has a conductive current collector portion (31) arranged in contact with the counter electrode, a rib portion (32) arranged along an outer peripheral edge portion of the current collector portion and surrounding the outside of the electrochemical cell, and a plurality of conductive support legs (33) protruding from the current collector portion to a side opposite the counter electrode and positioned within the gas flow path, The support leg has a protruding end (331) electrically connected to the working electrode of the adjacent single-layer cell. [2] A gas adsorption device (100) comprising the electrochemical cell stack according to [1], a pair of bus bars (41, 42) arranged at both ends of the electrochemical cell stack in a stacking direction (X), and a power source (B) connected to the pair of bus bars, The electrochemical cell includes an adsorbent in the working electrode capable of adsorbing a specific gas contained in the gas introduced from the gas flow path, and is configured such that when a voltage supplied from the power source via the pair of bus bars is applied between the working electrode and the counter electrode, electrons are supplied from the counter electrode side to the working electrode side, thereby adsorbing the specific gas into the adsorbent. [3] The gas adsorption device described in [2], wherein in the frame member, the current collecting plate portion has a first surface (311) that abuts against the counter electrode and a second surface (312) that faces the gas flow path, and the rib portion is joined to an outer circumferential side portion that connects the first surface and the second surface of the current collecting plate portion or to an outer circumferential edge portion of the first surface. [4] The gas adsorption device described in [2] or [3], wherein in the frame member, the multiple support legs are integrally formed with the current collecting plate portion and formed in a plate or protrusion shape protruding in the stacking direction. [5] The gas adsorption device according to [4], wherein the plurality of support legs in the frame member have a spring structure. [6] The gas adsorption device according to any one of [2] to [5], wherein the specific gas is CO2, and the adsorbent is a CO2 adsorbent. [Explanation of symbols]

[0094] 1. Electrochemical cell stack 11 Gas flow path 2. Electrochemical Cell 21 Working electrode 22 Opposite 3 Frame components (current collecting frame) 31 Current collector plate 32 Rib section 33 Support legs 100 Gas adsorption device (carbon dioxide capture device)

Claims

1. The electrochemical cell stack (1) is formed by stacking a plurality of single-layer cells (C) each including an electrochemical cell (2) having a working electrode (21) and a counter electrode (22) arranged opposite each other, and a frame member (3) supporting the electrochemical cell, in a direction in which the working electrode and the counter electrode face each other, A gas flow path (11) is defined between the single-layer cells adjacent to each other in the stacking direction (X), In the electrochemical cell, a gas (G) is introduced from the gas flow channel to the working electrode, and a voltage is applied between the working electrode and the counter electrode to cause an electrochemical reaction; the frame member has a conductive current collector portion (31) arranged in contact with the counter electrode, a rib portion (32) arranged along an outer peripheral edge portion of the current collector portion and surrounding the outside of the electrochemical cell, and a plurality of conductive support legs (33) protruding from the current collector portion to a side opposite the counter electrode and positioned within the gas flow path, The support leg has a protruding end (331) electrically connected to the working electrode of the adjacent single-layer cell.

2. A gas adsorption device (100) comprising: the electrochemical cell stack according to claim 1; a pair of bus bars (41, 42) disposed at both ends of the electrochemical cell stack in a stacking direction (X); and a power source (B) connected to the pair of bus bars, The electrochemical cell includes an adsorbent in the working electrode capable of adsorbing a specific gas contained in the gas introduced from the gas flow path, and is configured such that when a voltage supplied from the power source via the pair of bus bars is applied between the working electrode and the counter electrode, electrons are supplied from the counter electrode side to the working electrode side, thereby adsorbing the specific gas into the adsorbent.

3. 3. The gas adsorption device according to claim 2, wherein in the frame member, the current collecting plate portion has a first surface (311) that abuts against the counter electrode and a second surface (312) that faces the gas flow path, and the rib portion is joined to an outer circumferential side portion that connects the first surface and the second surface of the current collecting plate portion or to an outer circumferential edge portion of the first surface.

4. 3. The gas adsorption device according to claim 2, wherein in said frame member, said plurality of support legs are integrally provided with said current collecting plate portion and formed in a plate-like or protruding shape protruding in said stacking direction.

5. The gas adsorption apparatus according to claim 4 , wherein the plurality of support legs of the frame member have a spring structure. [Request 6] The specific gas is CO 2 and the adsorbent is CO 2 The gas adsorption device of claim 2 which is an adsorbent.

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