Electrochemical cell stack

Abstract

To provide an electrochemical cell stack which can be prevented from generating defects.SOLUTION: The electrochemical cell stack according to an embodiment includes: an electrochemical cell in the shape of a flat plate; a separator laminated on the electrochemical cell alternately; a fuel pole conductive member; and an air pole conductive member. The electrochemical cell includes a fuel pole, an air pole, and an electrolyte layer inserted between the fuel pole and the air pole. The fuel pole conductive member is inserted between the fuel pole and the separator. The air pole conductive member is inserted between the air pole and the separator. At least one of the fuel pole conductive member and the air pole conductive member has a Young ratio of 10-2 GPa to 10 GPa.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This embodiment relates to an electrochemical cell stack.

Background Art

[0002] Hydrogen is one of the raw materials for generating new energy. As a technology for utilizing this hydrogen, a fuel cell that converts chemical energy into electrical energy by electrochemically reacting hydrogen and oxygen is known. Fuel cells have high energy utilization efficiency and are being developed as large-scale distributed power sources, household power sources, and mobile power sources. Fuel cells are classified into solid polymer type, phosphoric acid type, molten carbonate type, solid oxide type, etc. according to the temperature range, the materials used, or the type of fuel. Among these, the solid oxide fuel cell (SOFC) is known to have high efficiency. In an SOFC, an electrochemical cell including an electrolyte layer made of a solid oxide is used, and electrical energy is obtained by performing an electrochemical reaction.

[0003] On the other hand, as a method for producing hydrogen, an electrolysis reaction method of water is known. One of the electrolysis reaction methods is a high-temperature steam electrolysis method in which electrolysis is performed in a state of high-temperature steam. This high-temperature steam electrolysis method has the characteristic of being more efficient than a general water electrolysis method. Its operating principle is based on a reaction opposite to that of an SOFC. Also in the high-temperature steam electrolysis method, an electrochemical cell (SOEC) including an electrolyte layer made of a solid oxide is used, similar to an SOFC.

[0004] The solid oxide type electrochemical cells used in SOFCs and SOECs can be configured in various shapes such as flat plate type, cylindrical type, cylindrical flat plate type, honeycomb type, etc. The electrochemical cells are stacked to form a stack. For example, flat plate type electrochemical cells are stacked via a conductive separator to form an electrochemical cell stack. The separator has the role of isolating the anode / cathode atmospheres and electrically connecting the electrochemical cells to each other. Also, the separator may sometimes play a role in equalizing the flow of reaction / exhaust gas.

[0005] As described above, in an electrochemical cell stack using a flat electrochemical cell, the electrochemical cell and the separator are laminated. For this reason, there is a concern about the occurrence of defects due to a decrease in the dimensional accuracy of the electrochemical cell and the separator, or the occurrence of some assembly defects.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The embodiments have been made in consideration of such points, and an object thereof is to provide an electrochemical cell stack capable of suppressing the occurrence of defects.

Means for Solving the Problems

[0008] The electrochemical cell stack according to the embodiment includes a flat electrochemical cell, a separator laminated alternately with the electrochemical cell, a fuel electrode conductive member, and an air electrode conductive member. The electrochemical cell includes a fuel electrode, an air electrode, and an electrolyte layer interposed between the fuel electrode and the air electrode. The fuel electrode conductive member is interposed between the fuel electrode and the separator. The air electrode conductive member is interposed between the air electrode and the separator. At least one of the fuel electrode conductive member and the air electrode conductive member has a Young's modulus of 10 -2 GPa to 10 GPa.

Effects of the Invention

[0009] According to the embodiment, the occurrence of defects can be suppressed.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

BEST MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, with reference to the drawings, the electrochemical cell stack according to the present embodiment will be described. In the drawings, for ease of understanding, the scale, the aspect ratio in the vertical and horizontal directions, etc. are appropriately changed and exaggerated from those of the actual object.

[0012] (First Embodiment) First, with reference to FIGS. 1 to 5, the electrochemical cell stack 1 according to the first embodiment will be described.

[0013] As shown in FIGS. 1 and 2, the electrochemical cell stack 1 includes a plurality of cell units 2 each including an electrochemical cell 10. The cell unit 2 includes a flat-plate type electrochemical cell 10, a separator 20, a fuel electrode conductive member 30, an air electrode conductive member 40, a support member 50, and an insulating member 60. A plurality of cell units 2 are stacked to form a stack 3. As shown in FIG. 1, the electrochemical cell stack 1 is assembled by pressing the stack 3 from both the upper and lower sides with clamping plates 4. The clamping plates 4 are tightened with bolts, nuts, etc. to press the stack 3.

[0014] As shown in FIG. 2, the electrochemical cell 10 includes a fuel electrode 11, an air electrode 12, and an electrolyte layer 13. The electrolyte layer 13 is interposed between the fuel electrode 11 and the air electrode 12. The air electrode 12 has a planar shape smaller than that of the fuel electrode 11 and the electrolyte layer 13. The electrolyte layer 13 is exposed around the air electrode 12. The electrochemical cell 10 may have a rectangular planar shape along the X direction and the Y direction described later, or may have a square or rectangular planar shape. However, the planar shape of the electrochemical cell 10 may be circular and is arbitrary.

[0015] The electrochemical cell 10 may be a solid oxide type cell. Also, the electrochemical cell 10 may be of an electrode-supported type or an electrolyte-supported type, and the support type of the electrochemical cell 10 is arbitrary.

[0016] The electrochemical cell 10 is configured such that the fuel gas supplied to the fuel electrode 11 and the air supplied to the air electrode 12 undergo an electrochemical reaction. When the electrochemical cell stack 1 is used as an SOFC, a power generation reaction for generating electric energy is performed. In this case, the fuel gas may be a gas mainly composed of hydrogen, a gas obtained by reforming a hydrocarbon-based fuel, or ammonia gas. When the electrochemical cell stack 1 is used as an SOEC, an electrolysis reaction is performed using electric energy. In this case, water vapor or carbon dioxide gas as the fuel gas may be electrolyzed.

[0017] The separator 20 is alternately laminated with the electrochemical cell 10. The separator 20 has conductivity and gas impermeability. The separator 20 isolates the fuel gas atmosphere and the air atmosphere.

[0018] The separator 20 may include a separator recess 21 that houses the fuel electrode conductive member 30, the fuel electrode 11, and the electrolyte layer 13. When the electrochemical cell 10 has a rectangular planar shape, the separator recess 21 may have a rectangular planar shape along the X direction and the Y direction described later. The depth of the separator recess 21 may be equal to the total thickness of the fuel electrode conductive member 30, the fuel electrode 11, and the electrolyte layer 13.

[0019] The separator 20 may include a frame plate portion 22 and a convex plate portion 23. The frame plate portion 22 is formed around the separator recess 21 and may have a rectangular frame-shaped planar shape. The frame plate portion 22 is a portion sandwiched between the support member 50 and the insulating member 60.

[0020] The convex plate portion 23 protrudes from the frame plate portion 22. The convex plate portion 23 defines the separator recess 21. The convex plate portion 23 includes a bottom plate portion 24 and a side plate portion 25. The bottom plate portion 24 may be parallel to the frame plate portion 22. The bottom plate portion 24 is a portion sandwiched between the fuel electrode conductive member 30 and the air electrode conductive member 40. The side plate portion 25 may be perpendicular to the frame plate portion 22 and the bottom plate portion 24. The separator recess 21 according to the present embodiment has a rectangular cross-sectional shape.

[0021] The separator 20 is formed as a single part. More specifically, the frame plate portion 22 and the convex plate portion 23 are integrally and continuously formed. Such a separator 20 can be manufactured using any processing method, and for example, it may be manufactured by sheet metal processing or press processing. The plate thickness of the separator 20 may be, for example, 1.0 mm or less, or may be 0.5 mm or less.

[0022] The fuel electrode conductive member 30 is interposed between the fuel electrode 11 and the separator 20. The fuel electrode conductive member 30 is in contact with the fuel electrode 11 and also in contact with the bottom plate portion 24 of the separator 20. The side surface 30a of the fuel electrode conductive member 30 faces the side plate portion 25 of the separator 20. The fuel electrode conductive member 30 has conductivity. The fuel electrode conductive member 30 may have a rectangular planar shape along the X direction and the Y direction, which will be described later.

[0023] The air electrode conductive member 40 is interposed between the air electrode 12 and the separator 20. The air electrode conductive member 40 is in contact with the air electrode 12 and also in contact with the bottom plate portion 24 of the separator 20. The side surface 40a of the air electrode conductive member 40 faces the inner side surface 60a of the insulating member 60. The air electrode conductive member 40 has conductivity. The air electrode conductive member 40 may have a rectangular planar shape along the X direction and the Y direction, which will be described later.

[0024] The support member 50 is disposed on the surface of the frame plate portion 22 of the separator 20 on the side of the convex plate portion 23. In the example shown in FIG. 2, the support member 50 is disposed below the frame plate portion 22. The support member 50 is interposed between the frame plate portion 22 and the insulating member 60. The support member 50 may be in close contact with the frame plate portion 22. The support member 50 may include a support opening 51 for accommodating the convex plate portion 23. The inner side surface of the support member 50 defining the support opening 51 may be in contact with, or close to and spaced from, the side plate portion 25. When the separator recess 21 has a rectangular planar shape, the support member 50 may have a rectangular frame-like planar shape. The thickness of the support member 50 may be equal to the height of the convex plate portion 23, or may be larger than the height of the convex plate portion 23. The support member 50 may have conductivity or may have insulating properties.

[0025] The insulating member 60 is disposed on the surface of the frame plate portion 22 of the separator 20 opposite to the convex plate portion 23. In the example shown in FIG. 2, the insulating member 60 is disposed above the frame plate portion 22. The insulating member 60 is interposed between the frame plate portion 22 and the support member 50. The insulating member 60 may include an insulating opening 61 that houses the air electrode 12 and the air electrode conductive member 40. The insulating opening 61 is defined by the inner surface 60a described above. The insulating member 60 may have a rectangular frame-like planar shape when the electrochemical cell 10 has a rectangular planar shape. The insulating member 60 extends to a position where it abuts against the electrolyte layer 13. The inner portion of the insulating member 60 abuts against the electrolyte layer 13 exposed around the air electrode 12, ensuring the airtightness between the insulating member 60 and the electrolyte layer 13. Further, the insulating member 60 also abuts against the bottom plate portion 24 of the separator 20 of the adjacent cell unit 2. The insulating member 60 has insulating properties and gas impermeability. The insulating member 60 separates the fuel gas atmosphere from the air atmosphere.

[0026] As described above, the electrochemical cell 10, the separator 20, the fuel electrode conductive member 30, and the air electrode conductive member 40 are pressed by the pressing force applied from the clamping plate 4. This ensures the conductivity within the laminate 3 and also ensures the airtightness.

[0027] As shown in FIGS. 2 to 4, the electrochemical cell stack 1 includes a fuel supply flow path 70, a fuel discharge flow path 75, an air supply flow path 80, and an air discharge flow path 85. FIG. 2 is a cross-sectional view taken along the line A-A shown in FIG. 3, and FIG. 4 is a cross-sectional view taken along the line B-B shown in FIG. 3. As shown in FIG. 3, an X direction and a Y direction orthogonal to the X direction are defined and will be described below. The stacking direction D of the laminate 3 is a direction orthogonal to both the X direction and the Y direction.

[0028] The fuel supply flow path 70 is configured to supply fuel gas to the fuel electrode 11. The fuel discharge flow path 75 is configured to discharge fuel gas from the fuel electrode 11.

[0029] As shown in FIG. 2, the fuel supply passage 70 includes a fuel supply main passage 71 and a fuel supply individual passage 72. The fuel supply main passage 71 is formed to extend in the stacking direction D of the laminate 3 and penetrates through the frame plate portion 22 of the separator 20, the support member 50, and the insulating member 60. The fuel supply individual passage 72 is formed to supply fuel gas from the fuel supply main passage 71 to the fuel passage 31 (described later) of the fuel electrode conductive member 30. As shown in FIGS. 2 and 3, the fuel supply individual passage 72 may be defined by a flow path recess 72a formed in a concave shape on the surface of the frame plate portion 22 of the separator 20 opposite to the convex plate portion 23 and the insulating member 60.

[0030] The fuel discharge passage 75 includes a fuel discharge main passage 76 and a fuel discharge individual passage 77. The fuel discharge main passage 76 is formed to extend in the stacking direction D of the laminate 3. The fuel discharge individual passage 77 is formed to discharge fuel gas from the fuel passage 31 of the fuel electrode conductive member 30 to the fuel discharge main passage 76. As shown in FIGS. 2 and 3, the fuel discharge individual passage 77 may be defined by a flow path recess 77a formed in a concave shape on the surface of the frame plate portion 22 of the separator 20 opposite to the convex plate portion 23 and the insulating member 60.

[0031] As shown in FIG. 3, the fuel supply main passage 71 is disposed on one side of the fuel electrode conductive member 30 in the X direction. The fuel discharge main passage 76 is disposed on the other side of the fuel electrode conductive member 30 in the X direction. The fuel electrode conductive member 30 is disposed between the fuel supply main passage 71 and the fuel discharge main passage 76. In the example shown in FIG. 3, one fuel supply main passage 71 and one fuel discharge main passage 76 are formed, but the number of the fuel supply main passages 71 and the number of the fuel discharge main passages 76 are arbitrary.

[0032] As shown in FIG. 3, when viewed in the stacking direction D, a fuel space 32 is formed between the fuel electrode conductive member 30 and the separator 20. The fuel space 32 is formed by the side surface 30a of the fuel electrode conductive member 30 and the side plate portion 25 of the convex plate portion 23 being separated from each other. The fuel space 32 includes a fuel inlet space 32a formed on the side of the fuel supply main flow path 71 with respect to the fuel electrode conductive member 30, and a fuel outlet space 32b formed on the side of the fuel discharge main flow path 76. The fuel inlet space 32a is disposed on one side of the fuel electrode conductive member 30 in the X direction, and the fuel outlet space 32b is disposed on the other side of the fuel electrode conductive member 30 in the X direction.

[0033] The fuel space 32 is also formed between the fuel electrode 11 and the separator 20 and between the electrolyte layer 13 and the separator 20 when viewed in the stacking direction D. As shown in FIGS. 2 and 4, the fuel space 32 extends in the stacking direction D to a position between the electrolyte layer 13 of the electrochemical cell 10 and the side plate portion 25. The fuel space 32 may be defined by the fuel electrode 11, the electrolyte layer 13, the convex plate portion 23, the fuel electrode conductive member 30, and the insulating member 60.

[0034] As shown in FIGS. 2 to 4, the fuel electrode conductive member 30 may include a plurality of fuel flow paths 31 through which the fuel gas supplied to the fuel electrode 11 flows. One end of the fuel flow path 31 opens into the fuel inlet space 32a, and the other end of the fuel flow path 31 opens into the fuel outlet space 32b. The fuel flow path 31 may be formed in a concave shape on the surface of the fuel electrode conductive member 30 on the side of the fuel electrode 11. With such a configuration, the fuel gas that has passed through the fuel supply individual flow path 72 and the fuel inlet space 32a from the fuel supply main flow path 71 flows into the fuel flow path 31. The fuel gas that has passed through the fuel flow path 31 is discharged into the fuel discharge individual flow path 77 through the fuel outlet space 32b. As shown in FIG. 3, the fuel flow path 31 may be configured as a straight flow path extending in the X direction, but the configuration of the fuel flow path 31 is not particularly limited. For example, the fuel flow path 31 may be configured by a serpentine flow path or the like. In FIG. 3, for the sake of convenience, one fuel flow path 31 is represented by a single line.

[0035] As shown in FIG. 3, the fuel electrode conductive member 30 may include a shielding portion 33. The shielding portion 33 is configured to prevent fuel gas from flowing from the fuel supply main channel 71 toward the fuel discharge main channel 76 without passing through the fuel flow channel 31 in the fuel space 32. As shown in FIG. 3, the shielding portions 33 are formed on both sides of the fuel electrode conductive member 30 in the Y direction. Each shielding portion 33 may be in contact with, or adjacent to and spaced apart from, an adjacent portion of the side plate portion 25 in the Y direction. The shielding portion 33 may be formed to protrude into the fuel space 32 when viewed in the stacking direction D. The shielding portion 33 divides the fuel inlet space 32a and the fuel outlet space 32b. As shown in FIGS. 3 and 4, the fuel space 32 is not formed at the position where the shielding portion 33 is present. The two shielding portions 33 may be arranged at the same position in the X direction or at different positions from each other.

[0036] As shown in FIG. 4, the shielding portion 33 extends to a position corresponding to the electrolyte layer 13 in the stacking direction D. More specifically, the shielding portion 33 extends in the stacking direction D to a position between the electrolyte layer 13 and the side plate portion 25. The shielding portion 33 may be in contact with the insulating member 60. In this way, the shielding portion 33 shields the flow of fuel gas in the fuel space 32.

[0037] The air supply channel 80 is configured to supply air to the air electrode 12. The air discharge channel 85 is configured to discharge air from the air electrode 12.

[0038] As shown in FIG. 4, the air supply channel 80 includes an air supply main channel 81 and an air supply individual channel 82. The air supply main channel 81 is formed to extend in the stacking direction D of the laminate 3 and penetrates the frame plate portion 22, the support member 50, and the insulating member 60 of the separator 20. The air supply individual channel 82 is formed to supply air from the air supply main channel 81 to the air flow channel 41 (described later) of the air electrode conductive member 40. The air supply individual channel 82 may be formed in a concave shape in the insulating member 60 as shown in FIG. 4, or may be formed in the support member 50.

[0039] As shown in FIG. 4, the air discharge passage 85 includes an air discharge main passage 86 and an air discharge individual passage 87. The air discharge main passage 86 is formed to extend in the stacking direction D of the laminate 3. The air discharge individual passage 87 is formed to discharge air from the air passage 41 of the air electrode conductive member 40 to the air discharge main passage 86. The air discharge individual passage 87 may be formed in a concave shape in the insulating member 60 or may be formed in the support member 50 as shown in FIG. 4.

[0040] As shown in FIG. 3, the air supply main passage 81 is disposed on one side of the air electrode conductive member 40 in the Y direction. The air discharge main passage 86 is disposed on the other side of the air electrode conductive member 40 in the Y direction. The air electrode conductive member 40 is disposed between the air supply main passage 81 and the air discharge main passage 86. In the example shown in FIG. 3, one air supply main passage 81 and one air discharge main passage 86 are formed, but the number of the air supply main passages 81 and the number of the air discharge main passages 86 are arbitrary.

[0041] As shown in FIG. 4, an air space 42 is formed between the air electrode conductive member 40 and the insulating member 60. The air space 42 according to the present embodiment is formed around the air electrode conductive member 40 within the insulating opening 61. More specifically, the air space 42 is formed by the separation between the side surface 40a of the air electrode conductive member 40 and the inner surface 60a of the insulating member 60. The air space 42 extends in the stacking direction D and is also formed around the air electrode 12 of the electrochemical cell 10. The air space 42 may be defined by the air electrode 12, the electrolyte layer 13, the bottom plate portion 24, the air electrode conductive member 40, and the insulating member 60.

[0042] As shown in FIGS. 2 and 4, the air electrode conductive member 40 may include a plurality of air flow paths 41 through which the air supplied to the air electrode 12 flows. Both ends of the air flow path 41 are open to the air space 42. The air flow path 41 may be formed in a concave shape on the surface of the air electrode conductive member 40 on the side of the air electrode 12. The flow path cross-sectional area of the air flow path 41 may be larger than the fuel cross-sectional area of the fuel flow path 31 described above. With such a configuration, air that has passed through the air supply individual flow path 82 and the air space 42 from the air supply main flow path 81 flows into the air flow path 41. The air that has passed through the air flow path 41 is discharged into the air discharge main flow path 86 through the air space 42 and the air discharge individual flow path 87. The air flow path 41 may be configured as a straight flow path extending in the Y direction, but the configuration of the air flow path 41 is not particularly limited. For example, the air flow path 41 may be configured by a serpentine flow path or the like.

[0043] The fuel electrode conductive member 30 and the air electrode conductive member 40 have conductivity even under high temperature conditions of 500°C to 1000°C. Further, the conductive members 30 and 40 may have flexibility. The conductive members 30 and 40 may have a structure such as a porous structure or a fibrous structure.

[0044] More specifically, at least one of the fuel electrode conductive member 30 and the air electrode conductive member 40 may have a Young's modulus of 10 -2 GPa to 10 GPa. In the present embodiment, both the fuel electrode conductive member 30 and the air electrode conductive member 40 have a Young's modulus of 10 -2 GPa to 10 GPa. However, this is not limited thereto, and if one of the fuel electrode conductive member 30 and the air electrode conductive member 40 has a Young's modulus of 10 -2 GPa to 10 GPa, the other may not have a Young's modulus of 10 -2 GPa to 10 GPa. The Young's modulus is 10 -2By setting it to 10 GPa or more, the conductive members 30 and 40 can ensure mechanical strength against the pressing force by the tightening plate 4. By setting the Young's modulus to 10 GPa or less, the conductive members 30 and 40 can have flexibility. The Young's modulus of the conductive members 30 and 40 may not be the Young's modulus obtained from a solid member made of the components described later that constitute the conductive members 30 and 40, but may be the Young's modulus obtained from a member made of the porous structure or fibrous structure described above. The Young's modulus may be a value under normal temperature environment. Since the assembly of the electrochemical cell stack 1 is performed under normal temperature environment, it is sufficient that the Young's modulus under normal temperature environment is defined. As a method for obtaining the Young's modulus, for example, a static measurement method can be mentioned. The static measurement method is a method of applying a static load such as tension, compression, bending, or torsion to a test piece and measuring stress and strain to obtain it. As a measuring device, for example, a precision universal testing machine (Model 5566) manufactured by Instron Corporation or a material testing machine (Autograph AG-25TD) manufactured by Shimadzu Corporation can be mentioned. The Young's modulus may be obtained from the graph of the stress-strain curve obtained from the measurement using such a device.

[0045] Examples of the materials of such conductive members 30 and 40 are not particularly limited. For example, Ni, Ag, Pt, Co, Cr, Cu, Ti, Sn, Al, and alloys containing at least two of these components can be mentioned as examples of the materials of the conductive members 30 and 40.

[0046] Next, the operation of the electrochemical cell stack 1 according to this embodiment having such a configuration will be described.

[0047] The fuel gas supplied to the fuel supply main flow path 71 passes through the fuel supply individual flow paths 72 and the fuel space 32 and flows into the fuel flow path 31 of the fuel electrode conductive member 30. While flowing through the fuel flow path 31, the fuel gas is supplied to the fuel electrode 11. On the other hand, the air supplied to the air supply main flow path 81 passes through the air supply individual flow paths 82 and the air space 42 and flows into the air flow path 41 of the air electrode conductive member 40. While flowing through the air flow path 41, the air is supplied to the air electrode 12. Then, an electrochemical reaction takes place in the electrochemical cell 10. When the electrochemical cell stack 1 is used as an SOFC, a power generation reaction occurs between the fuel gas and the air, generating electrical energy. When the electrochemical cell stack 1 is used as an SOEC, an electrolysis reaction takes place, and the fuel gas is electrolyzed.

[0048] The fuel gas that has passed through the fuel flow path 31 passes through the fuel space 32 and the fuel discharge individual flow path 77 and is supplied to the fuel discharge main flow path 76. The air that has passed through the air flow path 41 passes through the air space 42 and the air discharge individual flow path 87 and is discharged to the air discharge main flow path 86.

[0049] In this way, the fuel gas is continuously supplied to the fuel electrode 11, and the air is continuously supplied to the air electrode 12, and an electrochemical reaction takes place.

[0050] Thus, according to this embodiment, the fuel electrode conductive member 30 and the air electrode conductive member 40 are 10 -2It has a Young's modulus of from GPa to 10 GPa. As a result, each of the conductive members 30 and 40 can have flexibility. For this reason, the fuel electrode conductive member 30 can be in close contact with the bottom plate portion 24 of the separator 20 and can also be in close contact with the fuel electrode 11. The air electrode conductive member 40 can be in close contact with the bottom plate portion 24 of the separator 20 and can also be in close contact with the air electrode 12. For example, even when the dimensional accuracy of the electrochemical cell 10, the separator 20, and each of the conductive members 30 and 40 is low, or when these members are warped, the conductive members 30 and 40 can be deformed to be in close contact with other members. In this case, the conductivity of the electrochemical cell stack 1 can be improved. Further, it is possible to suppress the formation of a gap through which fuel gas flows between the fuel electrode conductive member 30 and the bottom plate portion 24 of the separator 20, and the fuel gas can be evenly flowed through the fuel flow path 31. Similarly, it is possible to suppress the formation of a gap through which air flows between the air electrode conductive member 40 and the bottom plate portion 24 of the separator 20, and the air can be evenly flowed through the air flow path 41. As a result, the occurrence of defects can be suppressed.

[0051] Further, according to the present embodiment, the separator 20 includes a separator recess 21 that houses the fuel electrode conductive member 30, the fuel electrode 11, and the electrolyte layer 13. Thereby, the thickness of the electrochemical cell stack 1 can be reduced.

[0052] Further, according to the present embodiment, it includes a convex plate portion 23 that defines the separator recess 21, and the convex plate portion 23 protrudes from the frame plate portion 22. Thereby, the separator 20 having the separator recess 21 can be easily manufactured. For example, the separator 20 can be easily manufactured by sheet metal working or press working.

[0053] Further, according to the present embodiment, the support member 50 is disposed on the surface of the frame plate portion 22 on the side of the convex plate portion 23. Thereby, even for the separator 20 including the convex plate portion 23, the separator 20 can be easily laminated by interposing the support member 50.

[0054] Further, according to the present embodiment, an insulating member 60 is disposed on the surface of the frame plate portion 22 opposite to the convex plate portion 23. This enables electrical insulation between adjacent frame plate portions 22 in the stacking direction D. Therefore, current can be collected by each of the conductive members 30 and 40.

[0055] Further, according to the present embodiment, the insulating member 60 extends to a position where it abuts on the electrolyte layer 13. This enables ensuring airtightness between the insulating member 60 and the electrolyte layer 13. Therefore, the atmosphere of the fuel gas and the atmosphere of the air can be isolated.

[0056] Further, according to the present embodiment, the fuel electrode conductive member 30 includes a fuel flow path 31 through which the fuel gas supplied to the fuel electrode 11 flows. This eliminates the need to form a flow path for flowing the fuel gas in the separator 20. Therefore, it is possible to suppress the occurrence of processing strain and the like in the separator 20, and to suppress the occurrence of defects due to assembly failure.

[0057] Further, according to the present embodiment, the fuel electrode conductive member 30 includes a shielding portion 33 that shields the flow of the fuel gas from the fuel supply main flow path 71 toward the fuel discharge main flow path 76 in the fuel space 32 formed between the fuel electrode conductive member 30 and the separator 20 when viewed in the stacking direction D without passing through the fuel flow path 31. This prevents the fuel gas from being discharged without passing through the fuel flow path 31 of the fuel electrode conductive member 30. Therefore, the fuel gas can be efficiently supplied to the fuel electrode 11, and the efficiency of the electrochemical reaction can be improved.

[0058] Further, according to the present embodiment, the shielding portion 33 extends to a position corresponding to the electrolyte layer 13 in the stacking direction D. Thus, even when a fuel space 32 is formed between the electrochemical cell 10 and the separator 20, it is possible to prevent the fuel gas flowing from the fuel supply main flow path 71 toward the fuel discharge main flow path 76 from flowing without passing through the fuel flow path 31. Therefore, it is possible to further prevent the fuel gas from being discharged without passing through the fuel flow path 31 of the fuel electrode conductive member 30. For this reason, the fuel gas can be supplied to the fuel electrode 11 more efficiently, and the efficiency of the electrochemical reaction can be further improved.

[0059] Further, according to the present embodiment, the air electrode conductive member 40 includes an air flow path 41 through which the air supplied to the air electrode 12 flows. Thus, it is not necessary to form a flow path for flowing air in the separator 20. Therefore, it is possible to suppress the occurrence of processing strain and the like in the separator 20, and it is possible to suppress the occurrence of defects due to assembly failure.

[0060] In the above-described present embodiment, an example in which the shielding portion 33 is formed on both sides in the Y direction with respect to the fuel electrode conductive member 30 has been described. However, the present invention is not limited to this. For example, as shown in FIG. 6, the shielding portion 33 may be formed on one side in the X direction with respect to the fuel electrode conductive member 30. As shown in FIG. 6, the two shielding portions 33 may be arranged on the side of the fuel supply main flow path 71. Alternatively, the two shielding portions 33 may be arranged on the side of the fuel discharge main flow path 76. One shielding portion 33 may be arranged on the side of the fuel supply main flow path 71, and the other shielding portion 33 may be arranged on the side of the fuel discharge main flow path 76.

[0061] In the above-described embodiment, an example has been described in which the separator 20 includes a separator recess 21 that houses the fuel electrode conductive member 30, the fuel electrode 11, and the electrolyte layer 13. However, the present invention is not limited to this. For example, the separator 20 may not include the separator recess 21. In this case, the separator 20 may be formed in a flat shape as a whole. In this case, for example, the support member 50 may be disposed on the surface of the frame plate portion 22 opposite to the convex plate portion 23.

[0062] In the above-described embodiment, an example has been described in which the shielding portion 33 extends to a position corresponding to the electrolyte layer 13 in the stacking direction D to shield the flow of the fuel gas. However, the present invention is not limited to this. For example, the shielding portion 33 may not extend in the stacking direction D. In this case, the fuel electrode 11 and the electrolyte layer 13 may each include a shielding portion (not shown) similar to the shielding portion 33 at a position overlapping the shielding portion 33 when viewed in the stacking direction D.

[0063] (Second Embodiment) Next, an electrochemical cell stack according to the second embodiment will be described with reference to FIGS. 6 to 8.

[0064] In the second embodiment shown in FIGS. 6 to 8, the main difference is that the side plate portion of the separator is inclined with respect to the bottom plate portion, and other configurations are substantially the same as those of the first embodiment shown in FIGS. 1 to 5. In FIGS. 6 to 8, the same parts as those of the first embodiment shown in FIGS. 1 to 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

[0065] As shown in FIG. 6, the side plate portion 25 of the separator 20 according to the present embodiment is inclined with respect to the bottom plate portion 24. The side plate portion 25 is inclined so as to spread outward of the laminate 3 from the bottom plate portion 24 toward the frame plate portion 22. The separator recess 21 has a reverse trapezoidal cross-sectional shape. The side plate portion 25 is also inclined with respect to the frame plate portion 22.

[0066] As shown in FIG. 7, the shielding portion 33 according to the present embodiment extends in the X direction of the fuel electrode conductive member 30, and may be in contact with, or close to and spaced from, adjacent portions in the X direction of the side plate portion 25 of the separator 20. The shielding portion 33 partitions the fuel inlet space 32a and the fuel outlet space 32b. As shown in FIGS. 7 and 8, the fuel space 32 is not formed at the position where the shielding portion 33 exists.

[0067] The fuel electrode conductive member 30 according to the present embodiment includes a conductive member recess 34 that houses the fuel electrode 11 and the electrolyte layer 13. The conductive member recess 34 may be defined by the two shielding portions 33 described above. The shielding portion 33 may be in contact with the insulating member 60 in the stacking direction D.

[0068] Thus, according to the present embodiment, the side plate portion 25 of the separator 20 is inclined with respect to the bottom plate portion 24. As a result, the separator 20 can be manufactured more easily. For example, the separator 20 can be easily manufactured by pressing.

[0069] Further, according to the present embodiment, the fuel electrode conductive member 30 includes a conductive member recess 34 that houses the fuel electrode 11 and the electrolyte layer 13. Thereby, it is possible to suppress the formation of a gap through which the fuel gas flows between the fuel electrode conductive member 30 and the bottom plate portion 24 of the separator 20, and the fuel gas can flow evenly through the fuel flow path 31. Further, the electrochemical cell 10 can be housed in the conductive member recess 34, and it is possible to prevent the electrochemical cell 10 from being displaced with respect to the fuel electrode conductive member 30.

[0070] In the above-described embodiment, an example in which the fuel electrode conductive member 30 includes the conductive member recess 34 that houses the fuel electrode 11 and the electrolyte layer 13 has been described. Such a conductive member recess 34 may be included in the fuel electrode conductive member 30 according to the first embodiment shown in FIGS. 1 to 6. In this case, the shielding portion 33 according to the first embodiment shown in FIGS. 1 to 6 may be configured in the same manner as the shielding portion 33 shown in FIG. 8.

[0071] According to the above-described specific embodiments, the occurrence of defects can be suppressed.

[0072] Although some embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalent scope. Also, naturally, within the scope of the gist of the present invention, it is also possible to appropriately combine these embodiments.

Explanation of Reference Numerals

[0073] 1: Electrochemical cell stack, 10: Electrochemical cell, 11: Fuel electrode, 12: Air electrode, 13: Electrolyte layer, 20: Separator, 21: Separator recess, 22: Frame plate portion, 23: Convex plate portion, 30: Fuel electrode conductive member, 30a: Side surface, 31: Fuel flow path, 32: Fuel space, 33: Shielding portion, 34: Conductive member recess, 40: Air electrode conductive member, 40a: Side surface, 41: Air flow path, 42: Air space, 50: Support member, 51: Support opening, 60: Insulating member, 61: Insulating opening, 71: Fuel supply main flow path, 76: Fuel discharge main flow path, 81: Air supply main flow path, 86: Air discharge main flow path, D: Laminating direction

Claims

1. A flat-type electrochemical cell including a fuel electrode, an air electrode, and an electrolyte layer interposed between the fuel electrode and the air electrode; A separator alternately laminated with the electrochemical cell; A fuel electrode conductive member interposed between the fuel electrode and the separator; An air electrode conductive member interposed between the air electrode and the separator, and At least the fuel electrode conductive member of the fuel electrode conductive member and the air electrode conductive member has a Young's modulus of 10 －２ GPa to 10 GPa, The separator includes a separator recess for accommodating the fuel electrode conductive member, the fuel electrode, and the electrolyte layer, a frame plate portion provided around the separator recess, and a convex plate portion protruding from the frame plate portion and defining the separator recess. An insulating member is disposed on a surface of the frame plate portion opposite to the convex plate portion. The insulating member includes an insulating opening for accommodating the air electrode and the air electrode conductive member. The insulating member extends to a position where it abuts against the electrolyte layer. An electrochemical cell stack in which, when viewed in the stacking direction, the fuel electrode conductive member overlaps the insulating member.

2. Further comprising a support member disposed on a surface of the frame plate portion on the side of the convex plate portion, and The support member includes a support opening for accommodating the convex plate portion. The electrochemical cell stack according to claim 1.

3. The convex plate portion includes a bottom plate portion and a side plate portion, and The side plate portion is inclined with respect to the bottom plate portion. The electrochemical cell stack according to claim 1 or 2.

4. The fuel electrode conductive member includes a conductive member recess for accommodating the fuel electrode and the electrolyte layer. The electrochemical cell stack according to any one of claims 1 to 3.

5. The fuel electrode conductive member includes a fuel flow path through which fuel gas supplied to the fuel electrode flows. The electrochemical cell stack according to any one of claims 1 to 4.

6. A fuel supply main flow path that penetrates the separator and supplies fuel gas to the fuel electrode, and A fuel discharge main flow path that penetrates the separator and discharges the fuel gas from the fuel electrode, and The fuel electrode conductive member includes a shielding portion that prevents the fuel gas from flowing from the fuel supply main flow path toward the fuel discharge main flow path without passing through the fuel flow path in a fuel space formed between the fuel electrode conductive member and the separator when viewed in the stacking direction. The electrochemical cell stack according to claim 5.

7. The shielding portion extends to a position corresponding to the electrolyte layer in the stacking direction. The electrochemical cell stack according to claim 6.

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