JP7186208B2 - Electrochemical reaction cell stack - Google Patents

Description

The technology disclosed by this specification relates to an electrochemical reaction cell stack.

A solid oxide fuel cell (hereinafter referred to as "SOFC") is known as one type of fuel cell that generates power using an electrochemical reaction between hydrogen and oxygen. A fuel cell power generation unit (hereinafter simply referred to as "power generation unit"), which is a structural unit of SOFC, is composed of an electrolyte layer containing a solid oxide and a predetermined direction (hereinafter referred to as "first direction") across the electrolyte layer. has a fuel cell single cell (hereinafter simply referred to as "single cell") including an air electrode and a fuel electrode facing each other.

An SOFC generally includes a structure (hereinafter referred to as a "power generation block") in which a plurality of power generation units are arranged in a first direction, and a pair of end members facing each other in the first direction with the power generation block interposed therebetween. is utilized in the form of a fuel cell stack comprising A power generation unit, for example, comprises a single cell and a peripheral member having a frame portion.

In general, a fuel cell stack is formed with a plurality of communication holes extending in a first direction over a plurality of power generation units. is concluded by Further, in this fuel cell stack, a washer, which is an annular flat plate member made of metal, is arranged between the nut and a member (for example, an end member) constituting the fuel cell stack (see, for example, Patent Documents 1).

JP 2018-147709 A

By the way, in the fuel cell stack described above, the end member is simply a plate-shaped member and has low rigidity, so there is a problem that it is difficult to suppress deformation. In addition, due to the low rigidity of the end member, deformation due to the fastening force of the fastening member in the end member, deformation in the first direction (for example, deformation of the end member surface of the fastening portion (head or nut) of the fastening member) It is difficult to transmit the fastening force in the planar direction of the end member, which may lead to deterioration in the performance of the fuel cell stack, for example.

It should be noted that such a problem is solved by an electrolytic cell comprising a plurality of electrolytic single cells, which are constituent units of a solid oxide type electrolytic cell (hereinafter referred to as "SOEC") that generates hydrogen using the electrolysis reaction of water. This is also a common issue for cell stacks. In this specification, the fuel cell single cell and the electrolysis single cell are collectively referred to as an electrochemical reaction single cell, and the fuel cell stack and the electrolysis cell stack are collectively referred to as an electrochemical reaction cell stack. Moreover, such a problem is not limited to SOFCs and SOECs, but is common to other types of electrochemical reaction cell stacks.

This specification discloses a technology capable of solving the above-described problems.

The technology disclosed in this specification can be implemented, for example, in the following forms.

(1) An electrochemical reaction cell stack disclosed in this specification is an electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in a first direction, each of the electrochemical reaction units is an electrochemical reaction unit cell including an electrolyte layer, and an air electrode and a fuel electrode facing each other in the first direction with the electrolyte layer interposed therebetween; when viewed in the first direction, the electrolyte layer; An electrochemical reaction block having a peripheral member having a frame portion surrounding a region where the air electrode and the fuel electrode overlap with each other; a pair of end members arranged so that at least a portion thereof overlaps the frame portion when viewed in the first direction; a shaft portion extending in the first direction; and both end portions of the shaft portion. and a fastening member having a pair of fastening portions coupled to the electrochemical reaction cell stack, wherein at least one of the pair of end members, the specific end member, has a surface perpendicular to the first direction A planar portion extending along a direction, the planar portion having a through hole into which the shaft portion is inserted, and a projection extending along the planar direction and protruding from the planar portion in the first direction. the flat portion of the specific end member; and the specific fastening portion as the fastening portion located on the same side of the electrochemical reaction block as the specific end member in the first direction. and a plate-shaped member disposed between the It has a partial outer edge that is a portion of the outer edge of the specific surface, and the partial outer edge has a shape along the outer edge of the convex portion facing the partial outer edge when viewed in the first direction.

In the present electrochemical reaction cell stack, since the specific end member has the convex portion, the rigidity in the vicinity of the convex portion of the specific end member is improved. deformation in can be suppressed. Further, in the present electrochemical reaction cell stack, the plate-like member is arranged between the plane portion of the specific end member and the specific fastening portion in the first direction. Therefore, the fastening force of the fastening member tends to be transmitted via the plate-shaped member to the vicinity of the outer edge of the plate-shaped member in the planar portion of the specific end member, and further to the planar portion continuous to the vicinity of the outer edge of the plate-shaped member. There is In the present electrochemical reaction cell stack, the partial outer edge, which is a part of the outer edge of the specific surface of the plate member, has a shape along the outer edge of the convex portion of the specific end member facing the partial outer edge when viewed in the first direction. have. In other words, when viewed from the first direction, the distance between the partial outer edge of the specific surface of the plate member and the outer edge of the convex portion of the specific end member is substantially uniform. Therefore, when viewed from the first direction, transmission is carried out via the plate-like member in the planar portion of the specific end member located between the partial outer edge of the specific surface of the plate-like member and the outer edge of the convex portion of the specific end member. The fastening force of the fastening member is substantially uniform in the extending direction of the convex portion. That is, it is possible to suppress deformation in the extending direction of the convex portion, and thus in the planar direction of the specific end member, due to the fastening force applied to the plane portion of the specific end member being concentrated on the specific location. Therefore, according to the present electrochemical reaction cell stack, by suppressing the deformation of the specific end member in the plane direction, it is possible to suppress deterioration of the performance of the electrochemical reaction cell stack.

(2) In the above electrochemical reaction cell stack, when viewed in the first direction, the gap distance between the partial outer edge of the plate-like member and the outer edge of the convex portion is the specified It may be configured to be smaller than the thickness of the planar portion of the end member. In the electrochemical reaction cell stack of this configuration, the gap distance between the partial outer edge of the plate member and the outer edge of the convex portion is smaller than the thickness of the planar portion of the specific end member in the first direction. In other words, the partial outer edge of the plate member and the outer edge of the convex portion are extremely close. According to this electrochemical reaction cell stack, by bringing the partial outer edge of the plate-shaped member, on which the fastening force of the fastening member tends to concentrate, closer to the vicinity of the convex portion with relatively high rigidity, the deformation in the plane direction of the specific end member can be further reduced. can be effectively suppressed.

(3) In the above electrochemical reaction cell stack, the thickness of the plate member in the first direction may be larger than the thickness of the plane portion of the specific end member. According to the electrochemical reaction cell stack of this configuration, the rigidity of the plate-shaped member is greater than the rigidity of the plane portion of the specific end member, so that the fastening is transmitted to the specific end member via the plate-shaped member. The fastening force of the member is relaxed, and thus the deformation in the plane direction of the specific end member can be suppressed more efficiently.

The technology disclosed in this specification can be implemented in various forms. It can be realized in the form of chemical reaction units (fuel cell power generation units or electrolysis cell units), electrochemical reaction cell stacks (fuel cell stacks or electrolysis cell stacks) comprising a plurality of electrochemical reaction units, manufacturing methods thereof, etc. is.

1 is a perspective view showing the external configuration of a fuel cell stack 100 according to this embodiment; FIG. Explanatory drawing showing the XZ cross-sectional configuration of the fuel cell stack 100 at the position II-II in FIG. Explanatory diagram showing the XZ cross-sectional configuration of the fuel cell stack 100 at the position III-III in FIG. Explanatory drawing showing the YZ cross-sectional configuration of the fuel cell stack 100 at the position IV-IV in FIG. Explanatory diagram showing the XZ cross-sectional configuration of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. Explanatory diagram showing the XZ cross-sectional configuration of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. Explanatory diagram showing the YZ cross-sectional configuration of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. Explanatory drawing showing the external configuration of the fuel cell stack 100 as viewed in the Z-axis direction. Explanatory drawing showing the external configuration of the fuel cell stack 100 according to the second embodiment as viewed in the Z-axis direction. Explanatory diagram showing the external configuration of the fuel cell stack 100 according to the third embodiment as viewed in the Z-axis direction.

A. First embodiment:
A-1. Constitution:
(Configuration of fuel cell stack 100)
FIG. 1 is a perspective view showing the external configuration of the fuel cell stack 100 in this embodiment, and FIG. 2 is an explanatory diagram showing the XZ cross-sectional configuration of the fuel cell stack 100 at the position II-II in FIG. 3 is an explanatory diagram showing the XZ cross-sectional configuration of the fuel cell stack 100 at the position III-III in FIG. 1, and FIG. 4 is the YZ cross-sectional configuration of the fuel cell stack 100 at the position IV-IV in FIG. It is an explanatory diagram showing. Each figure shows mutually orthogonal XYZ axes for specifying directions. In this specification, for the sake of convenience, the positive Z-axis direction is referred to as the upward direction, and the negative Z-axis direction is referred to as the downward direction. may be installed. The same applies to FIG. 5 and subsequent figures.

The fuel cell stack 100 includes a plurality of (seven in this embodiment) fuel cell power generation units (hereinafter simply referred to as "power generation units") 102, terminal separators 210, upper end plates 220, lower end plates 189, and a pair of terminals. It includes plates 410 and 420, an insulating portion 200, and a pair of end plates 104 and 106. As shown in FIG. The seven power generation units 102 are arranged side by side in a predetermined arrangement direction (vertical direction in this embodiment). One of the pair of terminal plates 410 and 420 (hereinafter referred to as "upper terminal plate 410") is located above an assembly (hereinafter referred to as "power generation block 103") composed of seven power generation units 102. The other of the pair of terminal plates 410 , 420 (hereinafter referred to as “lower terminal plate 420 ”) is arranged below the power generation block 103 . End separator 210 is positioned above upper terminal plate 410 and lower end plate 189 is positioned below lower terminal plate 420 . The insulating portion 200 is positioned above the terminal separator 210 . One of the pair of end plates 104, 106 (hereinafter referred to as "upper end plate 104") is arranged above the insulating portion 200, and the other of the pair of end plates 104, 106 (hereinafter referred to as "upper end plate 104") , referred to as “lower end plate 106 ”) are disposed below the lower end plate 189 . The pair of end plates 104 and 106 are arranged to sandwich the power generation block 103, the terminal separator 210, the lower end plate 189, the pair of terminal plates 410 and 420, and the insulating portion 200 from above and below. The arrangement direction (vertical direction) corresponds to the first direction in the scope of claims.

As shown in FIGS. 1 and 4, each layer (the power generation block 103, the terminal separator 210, the lower end plate 189, the pair of terminal plates 410 and 420, and the insulating portion 200) constituting the fuel cell stack 100 is shown in the Z-axis direction. Holes penetrating vertically through each layer are formed in the vicinity of the four corners of the outer circumference. Holes (screw holes) are formed through the upper end plate 104 in the vicinity of the four corners of the outer periphery around the Z-axis direction, and the lower end plate 106 near the four corners of the outer periphery of the lower end plate 106 around the Z-axis direction. A hole (screw hole) is formed through the . Corresponding holes formed in each layer communicate with each other in the vertical direction to form bolt holes 109 extending in the vertical direction. In the following description, the holes formed in each layer of the fuel cell stack 100 to constitute the bolt holes 109 may also be referred to as the bolt holes 109 .

A shaft portion 610 of a bolt 600 extending in the vertical direction is inserted through each bolt hole 109 . The bolt 600 has a head portion 620 at the upper end of the shaft portion 610 and includes a portion projecting outward from the shaft portion 610 as viewed in the Z-axis direction. More specifically, the head 620 is located on the same side as the upper end plate 104 (that is, on the upper side) with respect to the power generation block 103 in the Z-axis direction. A lower end portion of the bolt 600 (specifically, the shaft portion 610 ) is screwed into a threaded hole of the nut 630 via a hole of the lower end plate 106 . Each layer of the fuel cell stack 100 is integrally fastened by the bolts 600 and nuts 630 configured in this way. The bolt 600 is made of metal (such as iron or stainless steel). The bolt 600 corresponds to a fastening member in claims. The shaft portion 610 corresponds to the shaft portion in the claims. The head 620 and the nut 630 each correspond to a fastening portion in the claims. Furthermore, the head 620 corresponds to a specific fastening portion in the claims. A detailed configuration of the fastening portion between the head 620 and the upper end plate 104 will be described later.

Further, as shown in FIGS. 1 to 3, each layer (each power generation unit 102, lower terminal plate 420, lower end plate 189, lower end plate 106) constituting the fuel cell stack 100 has peripheral edges around the Z-axis direction. is formed with four holes vertically penetrating each layer, and the corresponding holes formed in each layer communicate with each other in the vertical direction, extending vertically from the uppermost power generation unit 102 to the lower end plate 106 A communication hole 108 extending in the direction is formed. In the following description, the holes formed in each layer of the fuel cell stack 100 to form the communication holes 108 may also be referred to as the communication holes 108 .

As shown in FIGS. 1 and 2, in the vicinity of one side (one of the two sides parallel to the Y-axis, the side on the positive side of the X-axis) that constitutes the outer circumference of the fuel cell stack 100 around the Z-axis direction. One communication hole 108 is a gas flow path through which an oxidant gas OG is introduced from the outside of the fuel cell stack 100 and supplies the oxidant gas OG to an air chamber 166 of each power generation unit 102, which will be described later. One communication hole 108 that functions as a gas supply manifold 161 and is located near the side opposite to the side (the side on the negative side of the X axis among the two sides parallel to the Y axis) is connected to each power generation unit. It functions as an oxidant gas discharge manifold 162 that is a gas flow path for discharging the oxidant offgas OOG, which is the gas discharged from the air chamber 166 of the fuel cell stack 102 , to the outside of the fuel cell stack 100 . For example, air is used as the oxidant gas OG.

1 and 3, among the sides forming the outer circumference of the fuel cell stack 100 around the Z-axis direction, the vicinity of the side closest to the communication hole 108 functioning as the oxidant gas discharge manifold 162 described above. Another communication hole 108 located in the fuel cell stack 100 is a gas flow path for introducing the fuel gas FG from the outside of the fuel cell stack 100 and supplying the fuel gas FG to a fuel chamber 176 of each power generation unit 102, which will be described later. Another communication hole 108 located near the side closest to the communication hole 108 functioning as the gas supply manifold 171 and functioning as the oxidant gas supply manifold 161 described above discharges from the fuel chamber 176 of each power generation unit 102. It functions as a fuel gas discharge manifold 172 that is a gas flow path for discharging the fuel off-gas FOG, which is the gas that has been discharged, to the outside of the fuel cell stack 100 . As the fuel gas FG, for example, a hydrogen-rich gas obtained by reforming city gas is used.

As shown in FIGS. 2 and 3, the fuel cell stack 100 is provided with four gas passage members 27 . Each gas passage member 27 has a hollow tubular body portion 28 and a hollow tubular branch portion 29 branched from a side surface of the main body portion 28 . A hole in the branch portion 29 communicates with a hole in the main body portion 28 . A gas pipe (not shown) is connected to the branch portion 29 of each gas passage member 27 . As shown in FIG. 2, the hole in the body portion 28 of the gas passage member 27 arranged at the position of the oxidant gas supply manifold 161 communicates with the oxidant gas supply manifold 161, and the oxidant gas discharge manifold 162 is connected. The hole of the body portion 28 of the gas passage member 27 arranged at the position communicates with the oxidant gas discharge manifold 162 . Further, as shown in FIG. 3, the hole of the body portion 28 of the gas passage member 27 arranged at the position of the fuel gas supply manifold 171 communicates with the fuel gas supply manifold 171, and the position of the fuel gas discharge manifold 172 is communicated with the fuel gas supply manifold 171. The hole of the main body portion 28 of the gas passage member 27 arranged at 1 is in communication with the fuel gas discharge manifold 172 . An insulating sheet 26 is interposed between each gas passage member 27 and the surface of the lower end plate 106 .

(Configuration of end plates 104, 106)
The pair of end plates 104 and 106 are plate-like members having a substantially rectangular outer shape when viewed in the Z-axis direction, and are made of a conductive material such as stainless steel. Holes 32 and 34 penetrating in the Z-axis direction are formed near the center of the pair of end plates 104 and 106, respectively. As viewed in the Z-axis direction, the inner peripheral lines of the holes 32, 34 formed in the pair of end plates 104, 106 respectively include at least a portion of each single cell 110, which will be described later. A compressive force in the Z-axis direction generated by tightening with each bolt 600 and nut 630 acts mainly on the peripheral portion of each power generation unit 102 (portion on the outer peripheral side from each unit cell 110 described later). The end plates 104 and 106 correspond to end members in the claims. Furthermore, the upper end plate 104 corresponds to a specific end member in the claims. A specific configuration of the end plates 104 and 106 will be described later.

(Configuration of Terminal Plates 410, 420)
The pair of terminal plates 410 and 420 are plate-like members having a substantially rectangular outer shape when viewed in the Z-axis direction, and are made of a conductive material such as stainless steel. A hole 412 is formed near the center of the upper terminal plate 410 so as to penetrate in the Z-axis direction. As viewed in the Z-axis direction, the inner peripheral line of the hole 412 formed in the upper terminal plate 410 includes each single cell 110 described later. As viewed in the Z-axis direction, one end (positive X-axis direction side) of each of the pair of terminal plates 410 and 420 protrudes laterally from the power generation block 103 . In this embodiment, the projecting portion of the upper terminal plate 410 functions as a positive output terminal of the fuel cell stack 100 , and the projecting portion of the lower terminal plate 420 functions as a negative output terminal of the fuel cell stack 100 . do.

(Configuration of upper end plate 220)
The upper end plate 220 is a plate-like member having a substantially rectangular outer shape when viewed in the Z-axis direction, and is made of a conductive material such as stainless steel. The upper end plate 220 is arranged above the power generation block 103 and electrically connected to the interconnector 190 positioned at the upper end of the power generation block 103 . In this embodiment, the upper end plate 220 and the interconnector 190 are electrically connected via a connecting member having the same structure as the fuel electrode side collector member 144 described later.

(Structure of Terminal Separator 210)
The terminal separator 210 is a frame-shaped member having a substantially rectangular through-hole 211 penetrating vertically in the vicinity of the center thereof, and is made of metal, for example. The terminal separator 210 has a relatively thin plate thickness, for example, about 0.05 mm or more and 0.2 mm or less. A portion of the terminal separator 210 surrounding the through hole 211 (hereinafter referred to as a “through hole surrounding portion”) is joined to the upper surface of the peripheral portion of the upper end plate 220 by, for example, welding. The end separator 210 separates the space between the top plate 220 and the power generation block 103 and the space outside the fuel cell stack 100 .

The end separator 210 has an inner portion 216 including a through-hole peripheral portion (a portion surrounding the through-hole 211) of the end separator 210, an outer portion 217 located on the outer peripheral side of the inner portion 216, and an inner portion 216 and an outer portion 217. and a connecting portion 218 that connects the In this embodiment, the inner portion 216 and the outer portion 217 are substantially flat plates extending in a direction substantially orthogonal to the Z-axis direction. Further, the connecting portion 218 has a curved shape that protrudes downward from both the inner portion 216 and the outer portion 217 . A lower portion (on the power generation block 103 side) of the connecting portion 218 is a convex portion, and an upper portion (on the upper end plate 104 side) of the connecting portion 218 is a concave portion. Therefore, the connecting portion 218 includes portions whose positions in the Z-axis direction are different from those of the inner portion 216 and the outer portion 217 .

(Configuration of lower end plate 189)
The lower end plate 189 is a plate-like member having a substantially rectangular outer shape when viewed in the Z-axis direction, and is made of an insulating material, for example. The peripheral edge of the lower end plate 189 is sandwiched between the lower terminal plate 420 and the lower end plate 106, thereby improving the sealing performance of the manifolds 161, 162, 171, 172 and the lower terminal plate 420. and insulation from the lower end plate 106 are ensured.

(Configuration of insulating portion 200)
The insulating part 200 is a frame-shaped (more specifically, rectangular frame-shaped) member having a substantially rectangular through-hole extending vertically through the vicinity of the center thereof. More specifically, as viewed in the Z-axis direction, the inner peripheral portion of the insulating portion 200 is located at the same position as the inner peripheral portion of the fuel electrode side frame 140 over the entire circumference, or is located on the inner peripheral side of the inner peripheral portion. is doing. As viewed in the Z-axis direction, the outer peripheral portion of the insulating portion 200 is positioned over the entire circumference at the same position as the outer peripheral portion of the fuel electrode side frame 140 or on the outer peripheral side of the outer peripheral portion. The insulating part 200 is made of an insulating material such as a mica sheet, a vermiculite sheet, a ceramic fiber sheet, a powdered ceramic sheet, a glass sheet, or a glass-ceramic composite. The thickness (sheet thickness) of the insulating portion 200 in the Z-axis direction is 0.1 mm or more and 5 mm or less, preferably 1 mm or more and 5 mm or less. The insulating portion 200 is sandwiched between the upper end plate 104 and the terminal separator 210 to provide sealing for each manifold 161 , 162 , 171 , 172 and insulation between the upper end plate 104 and the terminal separator 210 . is guaranteed. The holes forming the bolt holes 109 described above are formed in the peripheral edge portion around the Z-axis direction of the insulating portion 200 . In this specification, the term “conductive member” means a member having an electrical resistivity of 100 μΩ·m or less, and the term “insulating member” means a member having an electrical resistivity of 10 MΩ·m or more. is doing.

(Configuration of power generation unit 102)
5 is an explanatory diagram showing the XZ cross-sectional configuration of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. 2, and FIG. FIG. 7 is an explanatory diagram showing the XZ cross-sectional configuration of two power generation units 102, and FIG. 7 is an explanatory diagram showing the YZ cross-sectional configuration of two adjacent power generation units 102 at the same position as the cross section shown in FIG.

As shown in FIGS. 5 to 7, the power generation unit 102 includes a fuel cell single cell (hereinafter referred to as "single cell") 110, a single cell separator 120, an air electrode side frame 130, and a fuel electrode side frame. 140 , a fuel electrode side collector member 144 , and a pair of interconnectors 190 and a pair of IC separators 180 that constitute the uppermost and lowermost layers of the power generation unit 102 . Communicating holes 108 functioning as manifolds 161, 162, 171 and 172 are formed in the periphery of the unit cell separator 120, the air electrode side frame 130, the fuel electrode side frame 140, and the IC separator 180 around the Z-axis direction. Constituting holes and holes constituting each bolt hole 109 are formed.

The single cell 110 includes an electrolyte layer 112, an air electrode 114 arranged on one side (upper side) of the electrolyte layer 112 in the Z-axis direction, and an air electrode 114 arranged on the other side (lower side) of the electrolyte layer 112 in the Z-axis direction. It comprises an anode 116 and a reaction prevention layer 118 disposed between the electrolyte layer 112 and the cathode 114 . The single cell 110 of this embodiment is a fuel electrode supporting type single cell in which the fuel electrode 116 supports the other layers (electrolyte layer 112, air electrode 114, reaction prevention layer 118) that constitute the single cell 110. .

The electrolyte layer 112 is a substantially rectangular plate-shaped member when viewed in the Z-axis direction, and is configured to contain a solid oxide (for example, YSZ (yttria-stabilized zirconia)). That is, the single cell 110 of this embodiment is a solid oxide fuel cell (SOFC) using a solid oxide as an electrolyte. The air electrode 114 is a substantially rectangular plate-shaped member smaller than the electrolyte layer 112 when viewed in the Z-axis direction, and is configured to contain, for example, a perovskite oxide (for example, LSCF (lanthanum strontium cobalt iron oxide)). . The fuel electrode 116 is a substantially rectangular plate-shaped member having substantially the same size as the electrolyte layer 112 when viewed in the Z-axis direction, and is formed of, for example, Ni (nickel), a cermet made of Ni and ceramic particles, a Ni-based alloy, or the like. ing. The reaction prevention layer 118 is a substantially rectangular plate-shaped member having substantially the same size as the air electrode 114 when viewed in the Z-axis direction, and is configured to contain, for example, GDC (gadolinium-doped ceria) and YSZ. The reaction prevention layer 118 is formed by reacting an element (eg, Sr) diffused from the air electrode 114 with an element (eg, Zr) contained in the electrolyte layer 112 to generate a high-resistance substance (eg, SrZrO ₃ ). has the function of suppressing

The single-cell separator 120 is a frame-shaped member having a substantially rectangular through-hole 121 penetrating vertically in the vicinity of the center thereof, and is made of metal, for example. The plate thickness of the single cell separator 120 is relatively thin, for example, about 0.05 mm or more and 0.2 mm or less. A portion of the single-cell separator 120 surrounding the through-hole 121 (hereinafter referred to as a “through-hole surrounding portion”) faces the upper surface of the peripheral portion of the single-cell 110 (electrolyte layer 112). The unit cell separator 120 is joined to the unit cell 110 (electrolyte layer 112) by a joining portion 124 formed of a brazing material (for example, Ag brazing) placed at the opposing portion. An air chamber 166 facing the air electrode 114 and a fuel chamber 176 facing the fuel electrode 116 are partitioned by the single cell separator 120, and gas flows from one electrode side to the other electrode side in the peripheral portion of the single cell 110. leak (cross leak) is suppressed.

The single-cell separator 120 has an inner portion 126 including the through-hole peripheral portion (the portion surrounding the through-hole 121) of the single-cell separator 120, an outer portion 127 located on the outer peripheral side of the inner portion 126, and an inner portion 126. A connecting portion 128 that connects with the outer portion 127 is provided. In this embodiment, the inner portion 126 and the outer portion 127 are substantially flat plates extending in a direction substantially orthogonal to the Z-axis direction. Moreover, the connecting portion 128 has a curved shape that protrudes downward from both the inner portion 126 and the outer portion 127 . The lower side (fuel chamber 176 side) of connecting portion 128 is a convex portion, and the upper side (air chamber 166 side) portion of connecting portion 128 is a concave portion. Therefore, the connecting portion 128 includes portions whose positions in the Z-axis direction are different from those of the inner portion 126 and the outer portion 127 .

A glass seal portion 125 containing glass is arranged near the through hole 121 in the single cell separator 120 . The glass seal portion 125 is positioned on the air chamber 166 side with respect to the joint portion 124, and the surface of the unit cell separator 120 around the through hole and the surface of the unit cell 110 (the electrolyte layer 112 in this embodiment) is formed to contact both the The glass seal portion 125 effectively suppresses gas leak (cross leak) from one electrode side to the other electrode side in the peripheral portion of the unit cell 110 .

The interconnector 190 is a conductive member having a substantially rectangular flat plate-shaped flat plate portion 150 and a plurality of substantially columnar air electrode side current collectors 134 projecting from the flat plate portion 150 toward the air electrode 114 side. (for example, ferritic stainless steel). In this embodiment, the surface of the interconnector 190 (the surface facing the air chamber 166) is formed with a conductive coating layer 194 made of, for example, spinel oxide. Below, the interconnector 190 covered with the covering layer 194 is simply referred to as the interconnector 190 . In each power generation unit 102 , the upper interconnector 190 (the flat plate portion 150 thereof) is arranged above the single cell 110 with the air chamber 166 interposed therebetween. The upper interconnector 190 (each air electrode side current collector 134) is joined to the air electrode 114 of the unit cell 110 via a conductive joint material 196 made of, for example, spinel oxide. is electrically connected to the air electrode 114 of the single cell 110 by . In each power generation unit 102, the lower interconnector 190 is arranged below the unit cell 110 with the fuel chamber 176 interposed therebetween. It is electrically connected to the anode 116 of the cell 110 . The interconnector 190 ensures electrical continuity between the power generation units 102 and suppresses mixing of reaction gases between the power generation units 102 . In addition, in this embodiment, when two power generation units 102 are arranged adjacently, one interconnector 190 is shared by the two adjacent power generation units 102 . That is, the upper interconnector 190 in one power generation unit 102 is the same member as the lower interconnector 190 in another power generation unit 102 adjacent to the upper side of the power generation unit 102 . In addition, since the fuel cell stack 100 includes the lower terminal plate 420 and the lower end plate 189, the lowermost power generation unit 102 in the fuel cell stack 100 does not include the lower interconnector 190 (FIG. 2). to Figure 4).

The IC separator 180 is a frame-shaped member having a substantially rectangular through-hole 181 extending vertically through the vicinity of the center thereof, and is made of metal, for example. The plate thickness of the IC separator 180 is relatively thin, for example, about 0.05 mm or more and 0.2 mm or less. A portion of the IC separator 180 surrounding the through-hole 181 (hereinafter referred to as “through-hole surrounding portion”) is joined to the upper surface of the periphery of the flat plate portion 150 of the interconnector 190 by, for example, welding. Among the pair of IC separators 180 included in a power generation unit 102, the upper IC separator 180 is connected to the air chamber 166 of the power generation unit 102 and the other power generation unit 102 adjacent to the power generation unit 102 on the upper side. and the fuel chamber 176 of the . Also, of the pair of IC separators 180 included in a certain power generation unit 102, the lower IC separator 180 is adjacent to the fuel chamber 176 of the power generation unit 102 and the power generation unit 102 on the lower side. and the air chamber 166 of the power generation unit 102 . In this manner, the IC separator 180 suppresses gas leakage between the power generation units 102 at the periphery of the power generation units 102 . Note that the IC separator 180 joined to the upper interconnector 190 of the power generation unit 102 located at the uppermost position in the fuel cell stack 100 is electrically connected to the upper terminal plate 410 .

The IC separator 180 has an inner portion 186 including the peripheral portion of the through-hole (the portion surrounding the through-hole 181) of the IC separator 180, an outer portion 187 located outside the inner portion 186, and the inner portion 186 and the outer portion. 187 is provided. In this embodiment, the inner portion 186 and the outer portion 187 are substantially flat plates extending in a direction substantially orthogonal to the Z-axis direction. Further, the connecting portion 188 has a curved shape that protrudes downward from both the inner portion 186 and the outer portion 187 . The lower side (air chamber 166 side) of the connecting portion 188 is a convex portion, and the upper side (fuel chamber 176 side) portion of the connecting portion 188 is a concave portion. Therefore, the connecting portion 188 includes portions whose positions in the Z-axis direction are different from those of the inner portion 186 and the outer portion 187 .

As shown in FIGS. 5 to 7, the air electrode side frame 130 is a member having a frame portion in which a substantially rectangular hole 131 penetrating in the Z-axis direction is formed near the center. formed by The frame portion is a portion surrounding the region where the electrolyte layer 112, the air electrode 114, and the fuel electrode 116 overlap each other when viewed in the Z-axis direction, and each communication functioning as each of the manifolds 161, 162, 171, and 172 described above. Holes (manifold holes) forming the holes 108 are formed in the frame portion. A hole 131 in the cathode-side frame 130 constitutes an air chamber 166 facing the cathode 114 . The air electrode side frame 130 is in contact with the upper surface of the periphery of the single cell separator 120 and the lower surface of the periphery of the upper IC separator 180, and the gas sealing property ( That is, it functions as a sealing member that secures the gas sealing property of the air chamber 166 . Also, the cathode-side frame 130 electrically insulates between the pair of IC separators 180 included in the power generation unit 102 (that is, between the pair of interconnectors 190). The air electrode side frame 130 also includes an oxidant gas supply communication passage 132 that communicates the oxidant gas supply manifold 161 and the air chamber 166, and an oxidant gas supply passage 132 that communicates the air chamber 166 and the oxidant gas discharge manifold 162. A gas discharge communication channel 133 is formed.

As shown in FIGS. 5 to 7, the anode-side frame 140 is a member having a frame portion in which a substantially rectangular hole 141 penetrating in the Z-axis direction is formed near the center, and is made of metal, for example. there is The frame portion, like the frame portion of the cathode-side frame 130, is a portion surrounding the above region when viewed in the Z-axis direction. Also in the anode-side frame 140, the holes (manifold holes) forming the communication holes 108 are formed in the frame portion. A hole 141 in the anode-side frame 140 constitutes a fuel chamber 176 facing the anode 116 . The fuel electrode-side frame 140 is in contact with the lower surface of the periphery of the single cell separator 120 and the upper surface of the periphery of the lower IC separator 180 . Further, the fuel electrode side frame 140 has a fuel gas supply communication passage 142 that communicates the fuel gas supply manifold 171 and the fuel chamber 176, and a fuel gas discharge communication passage that communicates the fuel chamber 176 and the fuel gas discharge manifold 172. A path 143 is formed.

As shown in FIGS. 5 to 7 , the fuel electrode side collector member 144 is arranged inside the fuel chamber 176 . The fuel electrode-side current collecting member 144 includes an interconnector-facing portion 146, an electrode-facing portion 145, and a connecting portion 147 that connects the electrode-facing portion 145 and the interconnector-facing portion 146, and is made of, for example, nickel or a nickel alloy. , stainless steel or the like. The electrode facing portion 145 is in contact with the lower surface of the fuel electrode 116 , and the interconnector facing portion 146 is in contact with the upper surface of (the flat plate portion 150 of) the interconnector 190 . However, as described above, since the lowermost power generation unit 102 in the fuel cell stack 100 does not have the lower interconnector 190, the fuel electrode side current collecting member 144 of the power generation unit 102 faces the interconnector. Portion 146 contacts lower terminal plate 420 . Fuel electrode side current collecting member 144 having such a configuration electrically connects fuel electrode 116 and interconnector 190 (or lower end plate 189). A spacer 149 made of mica, for example, is arranged between the electrode facing portion 145 and the interconnector facing portion 146 of the fuel electrode side collector member 144 . Therefore, the fuel electrode side current collecting member 144 follows the deformation of the power generation unit 102 due to the temperature cycle and reaction gas pressure fluctuation, and the fuel electrode 116 and the interconnector 190 (or the lower terminal plate) via the fuel electrode side current collecting member 144. 420) is well maintained.

A-2. Operation of fuel cell stack 100:
As shown in FIGS. 2 and 5, the oxidant gas OG is supplied through a gas pipe (not shown) connected to the branch portion 29 of the gas passage member 27 provided at the position of the oxidant gas supply manifold 161. Then, the oxidizing gas OG is supplied to the oxidizing gas supply manifold 161 via the branch portion 29 of the gas passage member 27 and the hole of the main body portion 28, and the oxidizing gas OG is supplied from the oxidizing gas supply manifold 161 to each power generation unit 102. The agent gas is supplied to the air chamber 166 via the agent gas supply communication channel 132 . 3 and 6, the fuel gas FG is supplied through a gas pipe (not shown) connected to the branch portion 29 of the gas passage member 27 provided at the position of the fuel gas supply manifold 171. Then, the fuel gas FG is supplied to the fuel gas supply manifold 171 via the branch portion 29 of the gas passage member 27 and the hole of the main body portion 28, and the fuel gas supply communication of each power generation unit 102 from the fuel gas supply manifold 171. It is supplied to the fuel chamber 176 via the flow path 142 .

When the oxidant gas OG is supplied to the air chamber 166 of each power generation unit 102 and the fuel gas FG is supplied to the fuel chamber 176, electric power is generated in the single cell 110 by the electrochemical reaction of the oxidant gas OG and the fuel gas FG. will be This power generation reaction is an exothermic reaction. In each power generation unit 102, the air electrode 114 of the single cell 110 is electrically connected to the upper interconnector 190, and the fuel electrode 116 is connected to the lower interconnector 190 (or the lower interconnector) via the fuel electrode current collecting member 144. side terminal plate 420). That is, the plurality of power generation units 102 included in the fuel cell stack 100 are electrically connected in series. The upper interconnector 190 and the IC separator 180 of the uppermost power generation unit 102 are electrically connected to the upper terminal plate 410, and the fuel electrode side collector of the lowermost power generation unit 102 is electrically connected to the upper terminal plate 410. A lower terminal plate 420 is electrically connected to the electrical member 144 . Therefore, the electrical energy generated in each power generation unit 102 is taken out from terminal plates 410 and 420 that function as output terminals of fuel cell stack 100 . Since the SOFC generates power at a relatively high temperature (for example, 700° C. to 1000° C.), the fuel cell stack 100 is heated by the heater ( (not shown).

As shown in FIGS. 2 and 5, the oxidant off-gas OOG discharged from the air chamber 166 of each power generation unit 102 to the oxidant gas discharge manifold 162 through the oxidant gas discharge communication channel 133 is Through the holes in the main body portion 28 and the branch portion 29 of the gas passage member 27 provided at the position of the manifold 162, the gas is supplied to the outside of the fuel cell stack 100 via a gas pipe (not shown) connected to the branch portion 29. Ejected. Further, as shown in FIGS. 3 and 6, the fuel off-gas FOG discharged from the fuel chamber 176 of each power generation unit 102 to the fuel gas discharge manifold 172 through the fuel gas discharge communication passage 143 is The gas is discharged to the outside of the fuel cell stack 100 via a gas pipe (not shown) connected to the branch portion 29 through the holes of the body portion 28 and the branch portion 29 of the gas passage member 27 provided at the position of .

In the fuel cell stack 100 of the present embodiment, as viewed in the Z-axis direction, the oxidant gas supply communication channel 132 communicating with the oxidant gas supply manifold 161 and the fuel gas discharge communication channel 132 communicating with the fuel gas discharge manifold 172 are arranged. The passage 143 is arranged so as to face one side of the unit cell (in the same direction), and communicates with the oxidizing gas discharge manifold 162 and the fuel gas supply. The fuel gas supply communication channel 142 communicating with the manifold 171 is arranged so as to face (in the same direction) the other side of the unit cell 110 that faces one side of the unit cell 110 with the center point of the unit cell 110 therebetween. ing. That is, the power generation unit 102 (fuel cell stack 100) of the present embodiment is configured such that the main flow direction of the oxidizing gas OG in the air chamber 166 (the direction from the positive direction of the X axis to the negative direction of the X axis) and the fuel gas in the fuel chamber 176 This is a counter-flow type SOFC in which the main flow direction of the FG (the direction from the negative direction of the X-axis to the positive direction of the X-axis) is substantially opposite (directions facing each other).

A-3. Detailed Configuration of End Plates 104, 106:
A detailed configuration of the end plates 104 and 106 will be described.

(Configuration of upper end plate 104)
As shown in FIGS. 2-4, the upper end plate 104 includes a planar portion 310, a convex portion 320, and a raised portion 330. As shown in FIG. The planar portion 310 overlaps the fuel electrode side frame 140 when viewed in the Z-axis direction, and extends in a plane direction (direction parallel to the XY plane) perpendicular to the Z-axis direction. The plane portion 310 is a flat portion that has a predetermined area (for example, an area that connects two or more bolt holes 109 into which the fastening member (bolt 600) is inserted) and is parallel to the surface direction. Specifically, the shape of the planar portion 310 as viewed in the Z-axis direction is a rectangular frame shape as a whole. As viewed in the Z-axis direction, the inner peripheral portion of the flat portion 310 (the contour line of the hole 32 ) is located on the inner peripheral side of the contour line of the hole 141 of the fuel electrode side frame 140 over the entire circumference. As viewed in the Z-axis direction, the outer peripheral portion of the planar portion 310 is located at the same position as the outer peripheral portion of the fuel electrode side frame 140 or on the outer peripheral side of the outer peripheral portion over the entire circumference. That is, as viewed in the Z-axis direction, the outer peripheral side of the planar portion 310 overlaps the fuel electrode side frame 140 , and the inner peripheral side of the planar portion 310 protrudes inward from the fuel electrode side frame 140 . The holes forming the bolt holes 109 described above are formed in the peripheral edge portion of the flat portion 310 around the Z-axis direction. The fuel electrode side frame 140 or the air electrode side frame 130 corresponds to a peripheral member in the claims, and the hole 141 corresponds to a frame through hole in the claims. The flat portion 310 corresponds to the flat portion in the claims, and the convex portion 320 and the raised portion 330 respectively correspond to the convex portions in the claims.

The convex portion 320 extends along the surface direction and protrudes from the planar portion 310 in the Z-axis direction. The convex portion 320 is a rib that has a predetermined length (for example, a length greater than the thickness of the convex portion 320) and extends parallel to the surface direction (the convex portion 320). The length (the length in the Z-axis direction) of the convex portion 320 rising from the flat portion 310 is greater than the thickness of the flat portion 310, for example, preferably 30 times or more the thickness of the flat portion 310, and 50 times the thickness of the flat portion 310. A length equal to or greater than is more preferable. In addition, it is preferable that the convex portion 320 is formed at the peripheral portion of the area (flat portion 310) that connects two or more bolt holes 109 into which the fastening member (bolt 600) is inserted, for example.

Specifically, the convex portion 320 has an outer convex portion 322 and an inner convex portion 324 . The outer convex portion 322 protrudes from the outer peripheral portion of the flat portion 310 toward the upper side (the side opposite to the power generation block 103, the Z-axis positive direction side). Outer convex portion 322 is formed along the entire circumference of the outer peripheral portion of flat portion 310 . As viewed in the Z-axis direction, the outer convex portion 322 is arranged at a position overlapping the air electrode side frame 130 . The inner convex portion 324 protrudes from the inner peripheral portion of the flat portion 310 toward the upper side (the side opposite to the power generation block 103, the Z-axis positive direction side). The inner convex portion 324 is formed along the entire circumference of the inner peripheral portion of the planar portion 310 . That is, a plurality of protrusions 320 (outer protrusions 322 and inner protrusions 324) are formed in at least one section parallel to the Z-axis direction of the upper end plate 104 (see FIGS. 2 to 4).

The raised portion 330 is a portion that connects portions of the planar portion 310 and rises in the Z-axis direction in at least one cross section of the upper end plate 104 parallel to the Z-axis direction. That is, the raised portion 330 is formed at a position spaced apart from the peripheral portion of the upper end plate 104 and has a portion (a raised tip portion) whose position in the Z-axis direction is different from that of the planar portion 310 . The raised portion 330 has a predetermined length (for example, a length greater than the thickness of the convex portion 320) and extends parallel to the surface direction (the convex portion 320). Preferably, the raised portion 330 is positioned between two bolt holes 109 into which the fastening member (bolt 600) is inserted, and extends along the direction in which the two bolt holes 109 are arranged (see FIG. 1).

Specifically, ridge 330 is located between outer protrusion 322 and inner protrusion 324 on upper end plate 104 . Each raised portion 330 includes a pair of side walls 332 extending parallel to the protrusion 320, a connecting wall 334 connecting the upper ends of the pair of side walls 332, and a sealing wall connecting the longitudinal ends of the pair of side walls 332. 336 and . Each sidewall 332 is substantially perpendicular to the planar portion 310 , a connecting wall 334 is substantially parallel to the planar portion 310 , and each sealing wall 336 slopes from the connecting wall 334 toward the planar portion 310 . (see Figure 1).

(Configuration of lower end plate 106)
As shown in FIGS. 2-4, the lower end plate 106 includes a planar portion 510 and a convex portion 520. As shown in FIGS. The planar portion 510 overlaps the fuel electrode side frame 140 when viewed in the Z-axis direction, and extends in a plane direction (direction parallel to the XY plane) perpendicular to the Z-axis direction. The plane portion 510 is a flat portion that has a predetermined area (for example, an area that connects two or more bolt holes 109 into which the fastening member (bolt 600) is inserted) and is parallel to the surface direction. Specifically, the shape of the planar portion 510 as viewed in the Z-axis direction is a rectangular frame shape as a whole. As viewed in the Z-axis direction, the inner peripheral portion of the flat portion 510 (the contour line of the hole 34 ) is located on the inner peripheral side of the contour line of the hole 141 of the fuel electrode side frame 140 over the entire circumference. As viewed in the Z-axis direction, the outer peripheral portion of the planar portion 510 is positioned over the entire circumference at the same position as the outer peripheral portion of the fuel electrode side frame 140 or on the outer peripheral side of the outer peripheral portion. That is, as viewed in the Z-axis direction, the outer peripheral side of the planar portion 510 overlaps the fuel electrode side frame 140 , and the inner peripheral side of the planar portion 310 protrudes inward from the fuel electrode side frame 140 . In addition, the holes forming the bolt holes 109 described above are formed in the peripheral portion of the plane portion 510 around the Z-axis direction.

The convex portion 520 extends along the surface direction and protrudes from the planar portion 510 in the Z-axis direction. The convex portion 520 is a rib that has a predetermined length (for example, a length greater than the thickness of the convex portion 520) and extends parallel to the plane direction (the convex portion 520). The length (the length in the Z-axis direction) of the convex portion 520 rising from the flat portion 510 is greater than the thickness of the flat portion 510, for example, preferably 30 times or more the thickness of the flat portion 510, and 50 times the thickness of the flat portion 510. A length equal to or greater than is more preferable. In addition, it is preferable that the convex portion 520 is formed at the peripheral portion of the area (flat portion 510) that connects two or more bolt holes 109 into which the fastening member (bolt 22) is inserted, for example.

Specifically, the convex portion 520 has an outer convex portion 522 and an inner convex portion 524 . The outer convex portion 522 protrudes from the outer peripheral portion of the flat portion 510 toward the lower side (the side opposite to the power generation block 103, the Z-axis negative direction side). Outer convex portion 522 is formed along the entire circumference of the outer peripheral portion of flat portion 510 . As viewed in the Z-axis direction, the outer convex portion 522 is arranged at a position overlapping the fuel electrode side frame 140 . The inner convex portion 524 protrudes from the inner peripheral portion of the planar portion 510 toward the lower side (the side opposite to the power generation block 103, the Z-axis negative direction side). The inner convex portion 524 is formed along the entire circumference of the inner peripheral portion of the planar portion 510 . That is, a plurality of protrusions 520 (outer protrusions 522 and inner protrusions 524) are formed in at least one section parallel to the Z-axis direction of the upper end plate 104 (see FIGS. 2 to 4).

In the above embodiment, the surface of each of the end plates 104, 106 is formed with a passivation coating (for example, an alumina coating). Also, the projections 320 and 520 and the plane portions 310 and 510 are connected via the R portion, and the radius of the inner surface of the R portion is larger than the thickness of the plane portions 310 and 510 . Each of the end plates 104 and 106 is formed by pressing (bending) a plate member. Therefore, the thickness of the flat portions 310, 510, the thickness of the convex portions 320, 520, and the thickness of the raised portion 330 are the same. Specifically, the plate thickness of the end plates 104 and 106 (for example, the plate thickness T104 of the upper end plate 104) is about 0.5 mm or more and 3 mm or less.

In addition, in this embodiment, the tip portion of each of the projections 320 and 520 is bent in the plane direction. Thereby, the rigidity of each end plate 104, 106 is further improved. Further, the tip portion of each of the outer convex portions 322 and 522 is bent toward the outer peripheral side and protrudes outward from the power generation block 103 as viewed in the Z-axis direction. With such a configuration, it is possible to prevent the power generation block 103 from colliding with the floor surface when the fuel cell stack 100 is placed horizontally.

A-4. Detailed configuration of the fastening portion between the head 620 and the upper end plate 104:
FIG. 8 is an explanatory diagram showing the external configuration of the fuel cell stack 100 as viewed in the Z-axis direction. As shown in FIGS. 1, 4 and 8, in the fuel cell stack 100 of this embodiment, between the flat portion 310 of the upper end plate 104 and the head portion 620 of each bolt 600 in the Z-axis direction, A washer 500 is arranged respectively. The washer 500 corresponds to a plate member in the claims.

The washer 500 is a flat plate member having a bolt hole through which the shaft portion 610 of the bolt 600 can be inserted. . The washer 500 can be made of, for example, the same material as the bolt 600, and examples of such a material include metals (eg, iron and stainless steel). A thickness T500 of the washer 500 in the Z-axis direction is larger than a plate thickness T104 of the planar portion 310 of the upper end plate 104 (see FIG. 4). For example, the thickness T500 is about 0.6 mm or more and 15 mm or less. In this embodiment, the upper surface Sp500 of the washer 500 is in contact with the lower surface S620, which is the surface of the head 620 of the bolt 600, facing the upper surface Sp500. Among the surfaces of the flat portion 310 of the end plate 104, it is in contact with the upper side surface S310, which is the surface facing the lower side surface Sn500. Further, when viewed in the Z-axis direction, the outer edge E500 of the washer 500 surrounds the outer edge E620 of the head 620 (see FIG. 8). The lower surface Sn500 corresponds to the specific surface in the claims, and the outer edge E500 corresponds to the outer edge of the specific surface in the claims.

The outer edge E500 of the washer 500 has, as part of the outer edge E500, a partial outer edge Ep501 facing the outer edge E322 of the outer convex portion 322 of the upper end plate 104 and a partial outer edge Ep503 facing the outer edge E330 of the raised portion 330. there is In the present embodiment, the partial outer edge Ep501 is a straight line parallel to a portion of the outer edge E322 facing the partial outer edge Ep501, and when viewed in the Z-axis direction, the gap distance T1 between the partial outer edge Ep501 and the outer edge E322 is It is substantially uniform in the extending direction of the outer edge E322. In other words, when viewed in the Z-axis direction, the partial outer edge Ep501 has a shape along the portion of the outer edge E322 facing the partial outer edge Ep501. As viewed in the Z-axis direction, the gap distance T1 between the partial outer edge Ep501 and the outer edge E322 is smaller than the plate thickness T104 of the flat portion 310 of the upper end plate 104 in the Z-axis direction, for example, 0.1 mm or more. , about 2.5 mm or less. Further, in the present embodiment, the partial outer edge Ep503 is a straight line parallel to a portion of the outer edge E330 facing the partial outer edge Ep503, and the gap distance T3 between the partial outer edge Ep503 and the outer edge E330 is the extension of the outer edge E330. It is substantially uniform in direction. In other words, when viewed in the Z-axis direction, the partial outer edge Ep503 has a shape along the portion of the outer edge E330 facing the partial outer edge Ep503. As viewed in the Z-axis direction, the gap distance T3 between the partial outer edge Ep503 and the outer edge E330 is, for example, about 0.1 mm or more and 2 mm or less.

In addition, in the “partial outer edge facing the outer edge E322 of the outer convex portion 322 of the upper end plate 104” in the outer edge E500 of the washer 500, “opposing” means that the partial outer edge and the outer edge of the outer convex portion 322 are aligned in the plane direction. E322 means that both outer edges face each other with no other outer edge positioned between them. More specifically, the “outer edge E322 of the outer convex portion 322 of the upper end plate 104” is the side on which the washer 500 is positioned with respect to the specific point P on the partial outer edge Ep501 in the imaginary line segment VS shown in FIG. is the outer edge of the projection located on the opposite side (outside in this embodiment). Here, the virtual line segment VS is the virtual straight line VL that passes through the specific point P on the partial outer edge Ep501 and has the shortest distance from the outer convex portion 322 when viewed in the Z-axis direction. This is the part to exclude. A portion FP on the virtual straight line VL is a portion whose distance from the specific point P on the virtual straight line VL is greater than the distance between the specific point P and the intersection point P1. An area OA is an area where the electrolyte layer 112, the air electrode 114, and the fuel electrode 116 overlap each other when viewed in the Z-axis direction, and an intersection point P1 is an intersection point of the virtual straight line VL and the area OA when viewed in the Z-axis direction. This is the point of intersection with the smaller distance from the specific point P, out of P1 and P2.

A-5. Effect of this embodiment:
As described above, in the fuel cell stack 100 of this embodiment, each of the end plates 104, 106 is made of a thin plate with a thickness of 3 mm or less. As a result, compared to the conventional configuration including thick plate end members, the overall weight of the fuel cell stack 100 can be reduced. In addition, since the heat capacity of the entire fuel cell stack 100 can be reduced, it is possible to suppress operation delays in starting and stopping the fuel cell stack 100 due to response delays in the temperature control of the fuel cell stack 100 . However, in a configuration including such thin plate end members, the rigidity of the end members is low, so the end members are likely to be deformed due to repulsive force from the air electrode side frame 130 and the like functioning as compression seal members.

On the other hand, in the present embodiment, the end plates 104 and 106 are formed with convex portions 320 (protruding portions 330). The convex portion 320 (the raised portion 330) extends along the surface direction and protrudes from the flat portion 310 in the Z-axis direction. Therefore, the rigidity of the end plates 104, 106 is improved while reducing the weight and heat capacity of the end plates 104, 106. Specifically, in the fuel cell stack 100 of the present embodiment, the upper end plate 104 is provided with the convex portion 320 (the protruding portion 330), so that the rigidity of the upper end plate 104 near the protruding portion 320 (the protruding portion 330) is increased. In addition, compared to a configuration in which the upper end plate 104 does not include the convex portion 320 (the raised portion 330), the deformation in the surface direction caused by the repulsive force from the air electrode side frame 130 or the like can be suppressed. can be done.

In the present embodiment, a plurality of projections 320, 520 (outer projections 322, 522, inner projections 324, 524) are formed in at least one section parallel to the Z-axis direction of each of the end plates 104, 106. (See Figures 2-4). As a result, the rigidity of each end plate 104, 106 is further improved in comparison with a configuration in which only one protrusion is formed in the same cross section, so that the repulsive force from the air electrode side frame 130 or the like causes the end plate 104, 106 to be stiffened. Deformation of the plates 104 and 106 can be suppressed more effectively.

In this embodiment, the convex portions 320, 520 are formed on both the outer peripheral portion and the inner peripheral portion of the end plates 104, 106, respectively. As a result, the rigidity of the end plates 104, 106 is further improved compared to the configuration in which the protrusions 320, 520 are formed only on one of the outer peripheral portion and the inner peripheral portion of each end plate 104, 106, so that the air electrode Deformation of the end plates 104 and 106 due to the repulsive force from the side frames 130 and the like can be suppressed more effectively.

Protrusions 320 and 520 are formed over the entire circumference of each end plate 104 and 106 . As a result, the rigidity of the end plates 104, 106 is further improved compared to a configuration in which the projections 320, 520 are formed only on a part of the outer peripheral portions of the end plates 104, 106. deformation of the end member due to the repulsive force can be suppressed more effectively.

A raised portion 330 is formed on the upper end plate 104 . The raised portion 330 is a portion that connects portions of the planar portion 310 and rises in the Z-axis direction in at least one cross section of the upper end plate 104 parallel to the Z-axis direction. As a result, the rigidity of the upper end plate 104 is further improved, and deformation of the upper end plate 104 due to the repulsive force from the cathode-side frame 130 and the like can be more effectively suppressed.

The rising length (the length in the Z-axis direction) of the convex portions 320 and 520 from the flat portions 310 and 510 is greater than the thickness of the flat portions 310 and 510 . As a result, the rigidity of the end plates 104 and 106 is further improved compared to a configuration in which the rising length is equal to or less than the thickness of the flat portions 310 and 510, so that the repulsive force from the compression seal member causes the end plates to become stiff. Deformation of 104 and 106 can be suppressed more effectively.

As viewed in the Z-axis direction, the outer protrusions 322 and 522 are arranged at positions overlapping the cathode-side frame 130 . As a result, the sealing performance of the cathode-side frame 130 can be improved compared to a configuration in which none of the projections 320 and 520 are arranged at positions that overlap the cathode-side frame 130 .

In this embodiment, each surface of the end plates 104 and 106 is formed with a passive coating (for example, an alumina coating). When a member on which such a passivation film is formed is used for the end plates 104, 106, it is difficult to increase the thickness of the end plates 104, 106. However, by forming the protrusions 320, 520 and the like on the end plates 104, 106 as in the present embodiment, the rigidity of the end plates 104, 106 can be improved, which is particularly useful.

The convex portions 320, 520 and the flat portions 310, 510 are connected via the R portion, and the radius of the inner surface of the R portion is larger than the thickness of the flat portions 310, 510. As a result, compared to a configuration in which the radius of the R surface between the convex portions 320, 520 and the flat portions 310, 510 is equal to or less than the thickness of the flat portions 310, 510, the convex portions 320, 520 and the flat portions 310, 510 It is possible to suppress damage or the like due to stress concentration on the boundary portion between.

Further, in the fuel cell stack 100 of this embodiment, the washer 500 is arranged between the flat portion 310 of the upper end plate 104 and the bolt 600 in the Z-axis direction. Therefore, the fastening force of the bolt 600 is transmitted via the washer 500 to the vicinity of the outer edge E500 of the washer 500 in the planar portion 310 of the upper end plate 104, and further to the planar portion 310 continuous to the vicinity of the outer edge E500 of the washer 500. tend to In the fuel cell stack 100 of the present embodiment, a partial outer edge Ep501 (partial outer edge Ep503), which is a part of the outer edge E500 of the lower surface Sn500 of the washer 500, faces the partial outer edge Ep501 (partial outer edge Ep503) when viewed in the Z-axis direction. It has a shape along the outer edge E322 of the outer convex portion 322 of the upper end plate 104 (the outer edge E330 of the raised portion 330). In other words, when viewed in the Z-axis direction, between the partial outer edge Ep501 (partial outer edge Ep503) of the lower surface Sn500 of the washer 500 and the outer edge E322 of the outer convex portion 322 of the upper end plate 104 (the outer edge E330 of the raised portion 330). are substantially uniform. Therefore, when viewed in the Z-axis direction, between the partial outer edge Ep501 (partial outer edge Ep503) of the lower surface Sn500 of the washer 500 and the outer edge E322 of the outer convex portion 322 of the upper end plate 104 (outer edge E330 of the raised portion 330). The tightening force of the bolt 600 transmitted via the washer 500 to the flat portion 310 of the upper end plate 104 is substantially uniform in the extending direction of the outer convex portion 322 (the raised portion 330). That is, due to the concentration of the fastening force applied to the flat portion 310 of the upper end plate 104 to a specific portion, the extension direction of the outer convex portion 322 (the raised portion 330), and thus the surface direction of the upper end plate 104 Deformation can be suppressed. Therefore, according to the fuel cell stack 100 of the present embodiment, deterioration of the performance of the fuel cell stack 100 (for example, the sealing performance of the fuel cell stack 100) is suppressed by suppressing deformation of the upper end plate 104 in the plane direction. can do.

In the fuel cell stack 100 of the present embodiment, when viewed in the Z-axis direction, the gap distance T1 between the partial outer edge Ep501 of the washer 500 and the outer edge E322 of the outer convex portion 322, the partial outer edge Ep503 of the washer 500, and the raised portion The gap distance T3 between the outer edge E330 of the upper end plate 104 and the outer edge E330 is smaller than the plate thickness T104 of the flat portion 310 of the upper end plate 104 in the Z-axis direction. In the fuel cell stack 100 of this embodiment, the gap distance T1 (gap distance T3) is smaller than the plate thickness T104 of the planar portion 310 of the upper end plate 104 in the Z-axis direction. In other words, the partial outer edge Ep501 (partial outer edge Ep503) of the washer 500 and the outer edge E322 of the outer convex portion 322 (the outer edge E330 of the raised portion 330) are extremely close. According to the fuel cell stack 100 of the present embodiment, the partial outer edge Ep501 (partial outer edge Ep503) of the washer 500, on which the fastening force of the bolt 600 is likely to concentrate, is positioned near the outer convex portion 322 (the raised portion 330) having relatively high rigidity. By bringing the upper end plate 104 closer, deformation in the plane direction of the upper end plate 104 can be suppressed more efficiently.

In the fuel cell stack 100 of this embodiment, the thickness T500 of the washer 500 in the Z-axis direction is larger than the plate thickness T104 of the planar portion 310 of the upper end plate 104 . According to the fuel cell stack 100 of this embodiment, the rigidity of the washer 500 is greater than the rigidity of the flat portion 310 of the upper end plate 104, so that the transmission is transmitted to the upper end plate 104 via the washer 500. The tightening force of the bolt 600 is relaxed, and thus the deformation of the upper end plate 104 in the plane direction can be suppressed more efficiently.

B. Second embodiment:
FIG. 9 is an explanatory diagram showing the external configuration of the fuel cell stack 100a according to the second embodiment as viewed in the Z-axis direction. As shown in FIG. 9, the fuel cell stack 100a of the second embodiment has an upper end plate 104a and a washer 500a instead of the upper end plate 104 and the washer 500, respectively. It is different from the configuration of the fuel cell stack 100 in the form. In the following, of the configuration of the fuel cell stack 100a of the second embodiment, the same configurations as those of the fuel cell stack 100 of the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. .

The upper end plate 104a includes a flat portion 310a, a convex portion 320a, and a raised portion 330a. The flat portion 310a, the convex portion 320a, and the raised portion 330a have shapes different from those of the flat portion 310, the convex portion 320, and the raised portion 330, respectively, when viewed in the Z-axis direction. The convex portion 320a has an outer convex portion 322a and an inner convex portion 324a. When viewed in the Z-axis direction, the outer convex portion 322a and the inner convex portion 324a each have rounded corners. The flat portion 310a corresponds to the flat portion in the claims, and the convex portion 320a and the raised portion 330a respectively correspond to the convex portions in the claims.

Like the washer 500, the washer 500a is a flat plate member having a bolt hole through which the shaft portion 610 of the bolt 600 can be inserted. are arranged as The washer 500a is made of metal (for example, iron or stainless steel). Like the washer 500, the thickness of the washer 500a in the Z-axis direction is larger than the plate thickness of the flat portion 310a of the upper end plate 104a, and is, for example, about 0.6 mm or more and 15 mm or less. The outer edge E500a of the washer 500a surrounds the outer edge E620 of the head 620 when viewed in the Z-axis direction. The outer edge E500a corresponds to the outer edge of the specific surface in the claims.

The washer 500a has a base 501a and two arms 503a. In the washer 500a, bolt holes for the bolts 600 are formed in the base portion 501a. The arm portion 503a is a portion extending from the base portion 501a in the extending direction of the outer convex portion 322a. The base portion 501a and the two arm portions 503a are integrally formed.

The outer edge E500a of the washer 500a has, as part of the outer edge E500a, a partial outer edge Ep501a facing the outer edge E322a of the outer convex portion 322a of the upper end plate 104a and a partial outer edge Ep503a facing the outer edge E330a of the raised portion 330a. there is In this embodiment, the partial outer edge Ep501a is composed of a straight line parallel to a portion of the outer edge E322a facing the partial outer edge Ep501a and a curved line along the portion. is approximately uniform. In other words, the partial outer edge Ep501a has a shape along the portion of the outer edge E322a facing the partial outer edge Ep501a when viewed in the Z-axis direction. As in the first embodiment, the gap distance T1 is smaller than the plate thickness of the flat portion 310a of the upper end plate 104a in the Z-axis direction, and is, for example, about 0.1 mm or more and 2.5 mm or less. Further, in the present embodiment, the partial outer edge Ep503a is a straight line parallel to a portion of the outer edge E330a facing the partial outer edge Ep503a, and the gap distance T3 between the partial outer edge Ep503a and the outer edge E330a is the extension of the outer edge E330a. It is substantially uniform in direction. In other words, when viewed in the Z-axis direction, the partial outer edge Ep503a has a shape along a portion of the outer edge E330a facing the partial outer edge Ep503a. The gap distance T3 is, for example, about 0.1 mm or more and 2 mm or less, as in the first embodiment.

The fuel cell stack 100a of this embodiment also has the same effect as the fuel cell stack 100 of the first embodiment. That is, in the fuel cell stack 100a of the present embodiment, the partial outer edge Ep501a (partial outer edge Ep503a) of the washer 500a corresponds to the outer protrusion of the upper end plate 104a facing the partial outer edge Ep501a (partial outer edge Ep503a) when viewed in the Z-axis direction. 322a (outer edge E330a of raised portion 330a). Therefore, when viewed in the Z-axis direction, it is located between the partial outer edge Ep501a (partial outer edge Ep503a) of the lower surface of the washer 500a and the outer edge E322a of the outer convex portion 322a of the upper end plate 104a (outer edge E330a of the raised portion 330a). The fastening force of the bolt 600 transmitted via the washer 500a to the flat portion 310a of the upper end plate 104a becomes substantially uniform in the extending direction of the outer convex portion 322a (the raised portion 330a). Therefore, also in the fuel cell stack 100a of the present embodiment, it is possible to suppress deterioration of the performance of the fuel cell stack 100a (for example, the sealing performance of the fuel cell stack 100a).

C. Third embodiment:
FIG. 10 is an explanatory diagram showing the external configuration of the fuel cell stack 100b in the third embodiment as viewed in the Z-axis direction. As shown in FIG. 10, the fuel cell stack 100b of the third embodiment has an upper end plate 104b and a washer 500b instead of the upper end plate 104 and the washer 500, respectively. It is different from the configuration of the fuel cell stack 100 in the form. In the following description, of the configuration of the fuel cell stack 100b of the third embodiment, the configurations that are the same as those of the fuel cell stacks 100 and 100a of the above-described first and second embodiments are denoted by the same reference numerals. Description is omitted as appropriate.

The upper end plate 104b includes a planar portion 310b, a convex portion 320a, and a raised portion 330b. The flat portion 310b and the raised portion 330b have different shapes from the flat portions 310, 310a and the raised portions 330, 330a, respectively, when viewed in the Z-axis direction. The flat portion 310b corresponds to the flat portion in the claims, and the raised portion 330b corresponds to the convex portion in the claims.

Like the washer 500, the washer 500b is a flat plate member having a bolt hole through which the shaft portion 610 of the bolt 600 can be inserted. are arranged as The washer 500b is made of metal (for example, iron or stainless steel). Like the washer 500, the thickness of the washer 500b in the Z-axis direction is greater than the plate thickness of the planar portion 310b of the upper end plate 104b, and is, for example, about 0.6 mm or more and 15 mm or less. The outer edge E500b of the washer 500b surrounds the outer edge E620 of the head 620 when viewed in the Z-axis direction. The outer edge E500b corresponds to the outer edge of the specific surface in the claims.

The outer edge E500b of the washer 500b has, as part of the outer edge E500b, a partial outer edge Ep501b facing the outer edge E322a of the outer protrusion 322a of the upper end plate 104b and a partial outer edge Ep503b facing the outer edge E330b of the raised portion 330b. there is In this embodiment, the partial outer edge Ep501b is composed of a curved line along the portion of the outer edge E322a facing the partial outer edge Ep501b, and the gap distance T1 between the partial outer edge Ep501b and the outer edge E322a is substantially uniform. In other words, the partial outer edge Ep501b has a shape along the portion of the outer edge E322a facing the partial outer edge Ep501b when viewed in the Z-axis direction. As in the first embodiment, the gap distance T1 is smaller than the plate thickness of the flat portion 310b of the upper end plate 104b in the Z-axis direction, and is, for example, about 0.1 mm or more and 2.5 mm or less. Further, in the present embodiment, the partial outer edge Ep503b is a straight line parallel to a portion of the outer edge E330b facing the partial outer edge Ep503b, and the gap distance T3 between the partial outer edge Ep503b and the outer edge E330b is the extension of the outer edge E330b. It is substantially uniform in direction. In other words, when viewed in the Z-axis direction, the partial outer edge Ep503b has a shape along a portion of the outer edge E330b facing the partial outer edge Ep503b. The gap distance T3 is, for example, about 0.1 mm or more and 2 mm or less, as in the first embodiment.

The fuel cell stack 100b of this embodiment also has the same effect as the fuel cell stack 100 of the first embodiment. That is, in the fuel cell stack 100b of the present embodiment, the partial outer edge Ep501b (partial outer edge Ep503b) of the washer 500b corresponds to the outer protrusion of the upper end plate 104b facing the partial outer edge Ep501b (partial outer edge Ep503b) when viewed in the Z-axis direction. It has a shape along the outer edge E322a of 322a (the outer edge E330b of the raised portion 330b). Therefore, when viewed in the Z-axis direction, it is positioned between the partial outer edge Ep501b (partial outer edge Ep503b) of the lower surface of the washer 500b and the outer edge E322a of the outer convex portion 322a of the upper end plate 104a (outer edge E330b of the raised portion 330b). The tightening force of the bolt 600 transmitted via the washer 500b to the flat portion 310b of the upper end plate 104b becomes substantially uniform in the extending direction of the outer convex portion 322a (the raised portion 330b). Therefore, also in the fuel cell stack 100b of the present embodiment, it is possible to suppress deterioration in the performance of the fuel cell stack 100b (for example, the sealing performance of the fuel cell stack 100b).

D. Variant:
The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the scope of the invention. For example, the following modifications are possible.

The configuration of the fuel cell stack 100 and the configuration of each part that constitutes the fuel cell stack 100 in the above-described embodiment are merely examples, and various modifications are possible. For example, in the above embodiment, the single cell separator 120 and the IC separator 180 have the connecting portions 128 and 188, but the single cell separator 120 and the IC separator 180 have the connecting portions 128 and 188. You don't have to.

Further, in the above embodiment, the holes 32, 34 are formed in the pair of end plates 104, 106, but the holes 32, 34 may not be formed in at least one of the pair of end plates 104, 106. . At least one of the pair of end plates 104 and 106 may be a thick plate with a thickness exceeding 3 mm. Also, at least one of the pair of end plates 104, 106 may have a flat plate shape as a whole without the projections 320, 520 and the like. Further, in the above-described embodiment, the pair of terminal plates 410, 420 are provided. good. In this case, the end separator may be the IC separator 180 located at the upper end of the power generation block 103 in the Z-axis direction.

In the above embodiment, the convex portions 320, 520 protrude from the flat portions 310, 510 in the Z-axis direction, but the convex portions 320, 520 are inclined with respect to the direction perpendicular to the flat portions 310, 510. good too. The inclination angle of the convex portions 320, 520 with respect to the flat portions 310, 510 is preferably 70 degrees or more. Also, each of the projections 320, 520 is formed over the entire circumference of each end plate 104, 106, but each projection 320, 520 is formed only part of the entire circumference of each of the end plates 104, 106. may Alternatively, the projections 320, 520 may be formed only on either the outer peripheral portion or the inner peripheral portion of each end plate 104, 106. FIG. The rising length (the length in the Z-axis direction) of the convex portions 320 and 520 from the flat portions 310 and 510 may be equal to or less than the thickness of the flat portions 310 and 510 .

Upper endplate 104 may be configured without raised portion 330 . Also, the lower end plate 106 may be configured with a raised portion. Moreover, the configuration may be such that none of the projections 320 and 520 is arranged at a position not overlapping the air electrode side frame 130 .

In the above embodiment, the surfaces of the end plates 104 and 106 may not be formed with a passivation film. Further, the radius of the R surface between the convex portions 320, 520 and the flat portions 310, 510 may be less than or equal to the thickness of the flat portions 310, 510.

Moreover, although the interconnector 190 includes the conductive coating layer 194 in the above embodiment, the interconnector 190 may not include the coating layer 194 . Further, although the unit cell 110 has the reaction prevention layer 118 in the above embodiment, the unit cell 110 may not have the reaction prevention layer 118 . In the above embodiment, the number of single cells 110 (the number of power generation units 102) included in the fuel cell stack 100 is merely an example, and the number of single cells 110 is the output voltage required for the fuel cell stack 100. can be determined as appropriate. In addition, the materials forming each member in the above-described embodiment are merely examples, and each member may be formed of another material.

In the above-described embodiment, instead of the bolt 600 and the nut 630 having the shaft portion 610 and the head portion 620, for example, a shaft portion and a pair of nuts screwed onto both ends of the shaft portion may be provided.

In the above-described embodiment, the shape of the washers 500 , 500 a , 500 b is merely an example, and various modifications are possible as long as they have a partial outer edge along the outer edge of the convex portion or raised portion 330 . Also, a configuration may be adopted in which a part of the washers 500 , 500 a , 500 b is arranged at a position not overlapping the air electrode side frame 130 and/or the fuel electrode side frame 140 .

In the above embodiments, the outer edges E500, E500a, E500b of the washers 500, 500a, 500b may not surround part of the outer edge E620 of the head 620.

In the above embodiment, the thickness T500 of washer 500 may not be constant in the Z-axis direction. For example, the thickness near the outer edge E500 of the washer 500 may be smaller than the thickness near the bolt hole formed in the washer 500 .

In the above embodiment, a configuration is adopted in which the gap distance T1 (gap distance T3) between the washer 500 and the outer convex portion 322 (the raised portion 330) is equal to or greater than the plate thickness T104 of the flat portion 310 of the upper end plate 104. may Further, a configuration in which the thickness T500 of the washer 500 is equal to or less than the plate thickness T104 of the planar portion 310 of the upper end plate 104 may be employed.

In the above embodiment, a washer having a shape similar to that of the washer 500 and having a partial outer edge along the outer edge of the convex portion 520 of the lower end plate 106 is provided between the lower end plate 106 and the nut 603. may be adopted. Also, a configuration may be adopted in which the washer 500 provided on the upper end plate 104 side is omitted and the washer 500 is provided only on the lower end plate side.

Further, the fuel cell stack 100 of the above embodiment is a counterflow type SOFC, but the technology disclosed in this specification is similarly applicable to a coflow type SOFC. In the co-flow type SOFC, the fuel gas supply communication channel 142 and the oxidant gas supply communication channel 132 are arranged so as to face one side of the single cell 110 as viewed in the Z-axis direction, and , the fuel gas discharge communication channel 143 and the oxidizing gas discharge communication channel 133 are arranged so as to face the other side of the unit cell 110 with the center point of the unit cell 110 interposed therebetween. It has a configuration that is arranged. Also, the technology disclosed in this specification can be similarly applied to a cross-flow type SOFC.

Further, in the above-described embodiment, the target is the fuel cell stack 100 that generates power using the electrochemical reaction between hydrogen contained in the fuel gas and oxygen contained in the oxidant gas, but the present specification discloses The technology is equally applicable to electrolysis cell stacks comprising a plurality of electrolysis single cells, which are the building blocks of a solid oxide electrolysis cell (SOEC) that utilizes the electrolysis reaction of water to produce hydrogen. Note that the basic configuration of the electrolytic cell stack is publicly known as described, for example, in Japanese Patent Application Laid-Open No. 2016-81813, and is approximately as follows. That is, in the configuration of the fuel cell stack 100 of the embodiment described above, the configuration of the electrolysis cell stack is such that the “power generation unit” is replaced with the “electrolysis cell unit”, the “single cell” is replaced with the “electrolysis single cell”, and the “oxidation "oxygen gas supply manifold" should be read as "air discharge manifold", "oxidant gas discharge manifold" should be read as "air supply manifold", "fuel gas supply manifold" should be read as "hydrogen discharge manifold", and "fuel gas discharge manifold" should be read. ” should be read as “water vapor supply manifold”, “oxidant gas supply communication passage” should be read as “air discharge communication passage”, and “oxidant gas discharge communication passage” should be read as “air supply communication passage”. In this configuration, "fuel gas supply communication channel" is read as "hydrogen discharge communication channel", and "fuel gas discharge communication channel" is read as "steam supply communication channel".

During operation of the electrolytic cell stack, a voltage is applied to the electrolytic cell stack such that the air electrode 114 is positive (anode) and the fuel electrode (hydrogen electrode) 116 is negative (cathode). Also, steam as a raw material gas is supplied to the steam supply manifold through the gas passage member 27 . Hydrogen gas may be contained in the water vapor to be supplied. The water vapor supplied to the water vapor supply manifold is supplied from the water vapor supply manifold to the fuel chamber 176 through the water vapor supply communication channel of each electrolysis cell unit, and subjected to the electrolysis reaction of water in each electrolysis single cell. Hydrogen gas generated in the fuel chamber 176 by the electrolysis reaction of water in each electrolysis single cell is discharged to the hydrogen discharge manifold through the hydrogen discharge communication channel together with the surplus water vapor, and is discharged from the hydrogen discharge manifold through the gas passage member 27. It is taken out of the electrolytic cell stack.

Further, during operation of the electrolytic cell stack, air is supplied to the inside of the electrolytic cell stack as necessary in order to control the temperature of the electrolytic cell stack. In this case, the air supplied to the air supply manifold through the gas passage member 27 is supplied to the air chamber 166 from the air supply manifold through the air supply communication channel of each electrolytic cell unit. The air supplied to the air chamber 166 is discharged to the air discharge manifold through the air discharge communication channel together with the oxygen generated at the air electrode 114, and is discharged from the air discharge manifold through the gas passage member 27 to the outside of the electrolytic cell stack. Ejected.

Even in the electrolytic cell stack having such a configuration, by adopting a configuration similar to that of the fuel cell stack 100 in the above embodiment, the same effects as those of the fuel cell stack 100 in the above embodiment can be obtained.

Further, in the above embodiments, a solid oxide fuel cell (SOFC) was described as an example, but the technology disclosed in this specification can be applied to other types of fuel cells (such as a molten carbonate fuel cell (MCFC)). or electrolytic cell).

22: bolt 26: insulating sheet 27: gas passage member 28: main body 29: branch 32: hole 34: hole 100: fuel cell stack 100a: fuel cell stack 100b: fuel cell stack 102: power generation unit 103: power generation block 104 : Upper end plate 104a: Upper end plate 104b: Upper end plate 106: Lower end plate 108: Communication hole 109: Bolt hole 110: Single cell 112: Electrolyte layer 114: Air electrode 116: Fuel electrode 118: Reaction prevention layer 120 : Separator for single cell 121: Through hole 124: Joint portion 125: Glass seal portion 126: Inner portion 127: Outer portion 128: Connecting portion 130: Air electrode side frame 131: Hole 132: Oxidant gas supply communication channel 133: Oxidant gas discharge communication channel 134: air electrode side current collector 140: fuel electrode side frame 141: hole 142: fuel gas supply communication channel 143: fuel gas discharge communication channel 144: fuel electrode side current collector 145: Electrode facing portion 146: Interconnector facing portion 147: Connecting portion 149: Spacer 150: Flat plate portion 161: Oxidant gas supply manifold 162: Oxidant gas discharge manifold 166: Air chamber 171: Fuel gas supply manifold 172: Fuel gas discharge manifold 176: fuel chamber 180: IC separator 181: through hole 186: inner part 187: outer part 188: connecting part 189: lower end plate 190: interconnector 194: coating layer 196: conductive joint material 200: insulating part 210: end Separator 211: Through hole 216: Inner portion 217: Outer portion 218: Connecting portion 220: Upper end plate 310: Flat portion 310a: Flat portion 310b: Flat portion 320: Protruding portion 320a: Protruding portion 322: Outer protruding portion 322a: Outer protruding portion Part 324: Inner Protrusion 324a: Inner Protrusion 330: Raised Part 330a: Raised Part 330b: Raised Part 332: Side Wall 334: Connecting Wall 336: Sealing Wall 410: Upper Terminal Plate 412: Hole 420: Lower Terminal Plate 500 : Washer 500a: Washer 500b: Washer 501a: Base 503a: Arm 510: Plane 520: Convex 522: Outer convex 524: Inner convex 600: Bolt 610: Shaft 620: Head 630: Nut E322: Outer edge E322a: Outer edge E330: Outer edge E330a: Outer edge E330b: Outer edge E500 : Outer edge E500a: Outer edge E500b: Outer edge E620: Outer edge Ep501: Partial outer edge Ep501a: Partial outer edge Ep501b: Partial outer edge Ep503: Partial outer edge Ep503a: Partial outer edge Ep503b: Partial outer edge FG: Fuel gas FOG: Fuel off-gas FP: Part OA: Area OG : Oxidant gas OOG: Oxidant off-gas S310: Upper side S620: Lower side Sn500: Lower side Sp500: Upper side

Claims (3)

An electrochemical reaction block composed of a plurality of electrochemical reaction units arranged side by side in a first direction, wherein each of the electrochemical reaction units includes an electrolyte layer and the first direction with the electrolyte layer interposed therebetween. an electrochemical reaction unit cell including an air electrode and a fuel electrode facing each other; and a frame portion surrounding a region where the electrolyte layer, the air electrode, and the fuel electrode overlap each other when viewed from the first direction. an electrochemical reaction block comprising a peripheral member comprising;
A pair of end members facing each other in the first direction with the electrochemical reaction block interposed therebetween, wherein the pair of end members are arranged such that at least a portion thereof overlaps the frame portion when viewed in the first direction. When,
a fastening member having a shaft portion extending in the first direction and a pair of fastening portions connected to both ends of the shaft portion;
In an electrochemical reaction cell stack comprising:
The specific end member, which is at least one of the pair of end members,
a plane portion along a plane direction perpendicular to the first direction, the plane portion having a through hole into which the shaft portion is inserted;
a convex portion extending along the surface direction and projecting in the first direction from the planar portion;
disposed between the planar portion of the specific end member and a specific fastening portion as the fastening portion located on the same side of the electrochemical reaction block as the specific end member in the first direction; a plate-shaped member,
Of the surfaces of the plate member in the first direction, the outer edge of the specific surface, which is the surface facing the flat portion of the specific end member, has a partial outer edge that is a part of the outer edge of the specific surface. ,
The partial outer edge has a shape along the outer edge of the convex portion facing the partial outer edge when viewed in the first direction,
An electrochemical reaction cell stack characterized by: In the electrochemical reaction cell stack according to claim 1,
When viewed from the first direction, the gap distance between the outer edge of the portion of the plate member and the outer edge of the convex portion is compared with the thickness of the planar portion of the specific end member in the first direction. small,
An electrochemical reaction cell stack characterized by: In the electrochemical reaction cell stack according to claim 1 or claim 2,
the thickness of the plate member in the first direction is greater than the thickness of the plane portion of the specific end member;
An electrochemical reaction cell stack characterized by:

Images