JP2017204347A - Electrochemical reaction single cell, and method for manufacturing electrochemical reaction single cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of gas leak and support body breakage in an electrochemical reaction single cell.SOLUTION: An electrochemical reaction single cell comprises: a support body functioning as a fuel electrode; an electrolyte layer; and an air electrode. The support body has a cylindrical form opened at both ends and extending in a first direction, and it includes: a porous part having gas permeability and conductivity; and a dense part disposed to be aligned with the porous part in the first direction, and having a porosity lower than that of the porous part. The electrolyte layer is disposed on side of an inner surface of the support body, and it has a cylindrical form extending in the first direction and a porosity lower than that of the porous part. The air electrode is disposed on the side of an inner surface of the electrolyte layer, and it has a cylindrical form extending in the first direction and a porosity higher than that of the electrolyte layer.SELECTED DRAWING: Figure 4

Description

  The technology disclosed by the present specification relates to an electrochemical reaction unit cell.

  One type of fuel cell that generates electricity using an electrochemical reaction between hydrogen and oxygen is a solid oxide fuel cell (hereinafter referred to as “SOFC”) having an electrolyte layer containing a solid oxide. It has been. As a fuel cell single cell (hereinafter referred to as “single cell”) that is a constituent unit of SOFC, a cylindrical support functioning as a fuel electrode, a cylindrical electrolyte layer disposed on the inner surface side of the support, A single cell (hereinafter referred to as “tube type single cell”) having a cylindrical air electrode disposed on the inner surface side of an electrolyte layer is known (for example, see Patent Document 1). In the tube type single cell, fuel gas is supplied to the outside of the tube type single cell, oxidant gas is supplied to the hollow space of the tube type single cell, and hydrogen contained in the fuel gas and oxygen contained in the oxidant gas are mixed. Electrical energy is generated by the electrochemical reaction.

JP 2011-54549 A

  In the tube-type single cell having the above-described configuration, the fuel gas supplied to the outside of the tube-type single cell enters and diffuses into the support (fuel electrode). Therefore, it is necessary to increase the porosity of the support. Therefore, there exists a problem that the intensity | strength of the support body of a tube type single cell cannot fully be made high. Due to such problems, for example, in a configuration in which a joint for connecting a pipe for supplying and discharging oxidant gas to a tube type single cell is attached, the tightening force of the attachment portion cannot be increased sufficiently, and gas leakage occurs. May occur, or the support may be broken without being able to withstand the stress generated at the joint mounting location. Also, for example, in order to collect a plurality of tube-type single cells into a stack configuration, the plate-like member and each tube type with the tube-type single cell inserted into each hole of the plate-like member formed with a plurality of holes. When joining with a single cell, there exists a possibility that a support body may be broken without being able to endure the stress which arises in a joining location.

  Such a problem is not limited to the SOFC single cell, but is common to other types of fuel cells (including metal-air battery systems). Such a problem is not limited to a single fuel cell, but is also common to electrolytic single cells that are constituent units of electrolytic cells that generate hydrogen using an electrolysis reaction of water. In this specification, the fuel cell unit cell and the electrolysis unit cell are collectively referred to as an electrochemical reaction unit cell.

  In this specification, the technique which can solve the subject mentioned above is disclosed.

  The technology disclosed in the present specification can be realized as, for example, the following forms.

(1) The electrochemical reaction unit cell disclosed in the present specification is an electrochemical reaction unit cell having a cylindrical shape with both ends open in the first direction and having gas permeability and conductivity. A support portion that is arranged to be aligned with the porous portion in the first direction and has a lower porosity than the porous portion, and functions as a fuel electrode, and an inner surface side of the support portion An electrolyte layer having a lower porosity than the porous portion, and a cylindrical shape that is disposed on the inner surface side of the electrolyte layer and extends in the first direction. And an air electrode having a higher porosity than the electrolyte layer. According to the present electrochemical reaction single cell, the gas permeability of the support is maintained by the presence of the porous portion, and joining with a joint or the like is performed in the dense portion, thereby causing gas leakage or breakage of the support. Can be suppressed.

(2) In the electrochemical reaction single cell, the support is further disposed between the porous portion and the dense portion in the first direction, and has a lower porosity than the porous portion, and The intermediate portion may have a higher porosity than the dense portion. According to the present electrochemical reaction single cell, the presence of the intermediate portion can alleviate the porosity gradient between the porous portion and the dense portion while maintaining the porosity of the porous portion high, and the support It is possible to suppress the occurrence of breakage at the interface of each part constituting the.

(3) In the electrochemical reaction single cell, the formation material of the porous portion, the formation material of the dense portion, and the formation material of the intermediate portion may have the same composition. According to the present electrochemical reaction single cell, the thermal expansion coefficient of each part constituting the support can be made equal, and the breakage of the support due to the difference in thermal expansion between each part during firing or operation can be prevented. Can be suppressed.

(4) In the electrochemical reaction single cell, the dense portion may be arranged at at least one end of the support in the first direction. According to this electrochemical reaction single cell, gas leakage and breakage of the support are achieved while optimizing the arrangement of the joints, etc., by performing bonding with the joints, etc., in the dense portions arranged at both ends of the support. Can be suppressed.

(5) In the electrochemical reaction single cell, the dense portion may be configured to have conductivity. According to the present electrochemical reaction single cell, the area of the conductive portion of the support can be secured while suppressing the occurrence of breakage of the end of the support, and the conductivity disposed at both ends of the support can be secured. The terminal can be easily taken out from the dense part, and the structure can be simplified and the apparatus can be downsized.

(6) In the above electrochemical reaction unit cell, in the first direction, one end of the electrolyte layer is located at the same position as one end of the support or on the other end side from one end of the support. The one end of the air electrode may be located on the other end side from the one end of the electrolyte layer. According to the present electrochemical reaction single cell, the distance between the dense portion having conductivity and the air electrode can be secured, and the occurrence of a short circuit between them can be suppressed.

(7) In the above electrochemical reaction single cell, it is further disposed on the inner surface side of the electrolyte layer and on the outer surface side of the air electrode, has a higher porosity than the electrolyte layer, and extends in the first direction. It is good also as a structure provided with a cylindrical intermediate | middle layer. According to this electrochemical reaction single cell, the electrolyte layer and the air electrode can be joined via the porous intermediate layer, and the relatively dense electrolyte layer and the relatively porous air electrode are in contact with each other. In comparison, the bondability between the electrolyte layer and the air electrode can be improved.

(8) In the electrochemical reaction single cell, the intermediate layer may be formed of a mixed material of a material constituting the electrolyte layer and a material constituting the air electrode. According to this electrochemical reaction single cell, the difference in thermal expansion coefficient between the electrolyte layer and the air electrode can be reduced, and the occurrence of delamination due to the difference in thermal expansion during firing or operation can be suppressed.

(9) In the electrochemical reaction single cell, the electrolyte layer may be formed of at least one of YSZ, ScSZ, GDC, and LSGM. According to the present electrochemical reaction single cell, the reactivity of the electrochemical reaction can be improved.

(10) In the electrochemical reaction single cell, the porous portion may be formed of at least one of a mixture of Ni and YSZ and a mixture of Ni and GDC. According to the present electrochemical reaction single cell, the reactivity of the electrochemical reaction can be improved.

(11) The method for producing an electrochemical reaction single cell disclosed in the present specification is a cylindrical shape having open ends extending in a first direction, and has a porous portion having gas permeability and conductivity, and the first portion. A dense portion having a lower porosity than the porous portion, and a support functioning as a fuel electrode, disposed on the inner surface side of the support, A cylindrical shape extending in the first direction, having a lower porosity than the porous portion; and a cylindrical shape disposed on an inner surface side of the electrolyte layer and extending in the first direction; In the method for producing an electrochemical reaction single cell comprising an air electrode having a higher porosity than the layer, the support and the electrolyte layer are formed by simultaneously firing the material for forming the support and the material for forming the electrolyte layer. First to produce the first joined body A firing step and a second joined body of the first joined body and the air electrode are produced by disposing and firing the air electrode forming material on the inner surface side of the first joined body. 2 firing steps. According to the method for producing an electrochemical reaction single cell, the air electrode is produced in a second firing step different from the first firing step in which the support and the electrolyte layer are simultaneously fired. Since it can suppress that a porosity becomes low too much, while being able to suppress the fall of the gas permeability in an air electrode, the reduction | decrease of a three-layer interface can be suppressed.

(12) In the method for manufacturing an electrochemical reaction single cell, the second baking step includes a step of applying the air electrode forming material to the inner surface side of the first bonded body by a dip coating method. In the manufacturing method, after the second baking step, the end of the second bonded body in the first direction is deleted, and the position of the end of the support in the first direction is deleted. It is good also as a structure provided with the deletion process which arranges and the position of the end of the air electrode. According to the method for producing an electrochemical reaction single cell, the size of the single cell in the first direction can be reduced while suppressing a decrease in the capacity of the produced single cell.

(13) In the method for producing an electrochemical reaction single cell, the first bonded body includes an intermediate layer having a higher porosity than the electrolyte layer, in addition to the material for forming the support and the material for forming the electrolyte layer. It is a joined body of the support, the electrolyte layer, and the intermediate layer formed by simultaneously firing the forming material, and the second firing step is performed by the dip coating method, and the support, the electrolyte layer, It is good also as a structure including the process of apply | coating the formation material of the said air electrode to the inner surface side in a joined body with the said intermediate | middle layer. According to the method for producing an electrochemical reaction single cell, the presence of the relatively porous intermediate layer can improve the applicability of the air electrode forming material during dip coating.

  The technology disclosed in this specification can be realized in various forms. For example, an electrochemical reaction single cell (fuel cell single cell or electrolytic single cell), a plurality of electrochemical reaction single cells It can be realized in the form of an electrochemical reaction cell stack (fuel cell stack or electrolytic cell stack), a manufacturing method thereof, and the like.

It is explanatory drawing which shows the external appearance structure of the fuel cell single cell module 102 in this embodiment. It is explanatory drawing which shows the cross-sectional structure of the fuel cell single cell module 102 in this embodiment. It is explanatory drawing which shows the cross-sectional structure of the fuel cell single cell 110 in this embodiment. It is explanatory drawing which shows the cross-sectional structure of the fuel cell single cell 110 and the connection member 200 in this embodiment. 4 is a flowchart showing a method for manufacturing the fuel cell single cell module 102 in the present embodiment. It is explanatory drawing which shows the preparation methods of the support body molded object. 6 is a flowchart showing a flow of a manufacturing method of a fuel cell single cell module 102 in a modified example. FIG. 6 is an explanatory view showing a modification in which a plurality of fuel cell single cells 110 constitute a fuel cell stack 100.

A. Embodiment:
A-1. Constitution:
(Configuration of fuel cell single cell module 102)
FIG. 1 is an explanatory view showing an external configuration of a fuel cell single cell module (hereinafter referred to as “single cell module”) 102 in the present embodiment, and FIG. 2 shows a cross-sectional configuration of the single cell module 102 in the present embodiment. It is explanatory drawing shown. In each figure, XYZ axes orthogonal to each other for specifying the direction are shown. In this specification, for the sake of convenience, the positive direction of the Z-axis is referred to as the upward direction, and the negative direction of the Z-axis is referred to as the downward direction. It may be installed. The same applies to FIG. The Z-axis direction (vertical direction) corresponds to the first direction in the claims.

  The single cell module 102 includes a fuel cell single cell (hereinafter referred to as “single cell”) 110 and connection members 200 attached to both ends of the single cell 110. The single cell module 102 is used by being fixed between, for example, two metal plates 310 facing each other in the Z-axis direction. Specifically, the lower connection member 200 of the single cell module 102 is fixed to the lower metal plate 310, and the upper connection member 200 is fixed to the upper metal plate 310. One single cell module 102 may be installed between the two metal plates 310, or a plurality of single cell modules 102 may be installed. The space between the two metal plates 310 constitutes a fuel gas passage 176 through which a fuel gas FG (for example, a hydrogen-rich gas obtained by reforming city gas) flows.

(Configuration of single cell 110)
FIG. 3 is an explanatory diagram showing a cross-sectional configuration of the single cell 110 in the present embodiment. Moreover, FIG. 4 is explanatory drawing which shows the cross-sectional structure of the single cell 110 and the connection member 200 in this embodiment. 3 shows an XY cross-sectional configuration of the single cell 110 at the position of III-III in FIG. 2, and FIG. 4 shows an enlarged cross-sectional configuration of the portion X1 in FIG.

  The single cell 110 has a substantially cylindrical (tube-like) appearance as a whole, and includes a support 116, an electrolyte layer 112, an intermediate layer 113, and an air electrode layer 114. The support 116, the electrolyte layer 112, the intermediate layer 113, and the air electrode layer 114 all have a substantially cylindrical shape that is open at both ends and extends in the Z-axis direction. The support 116 is disposed on the outermost side of the unit cell 110, the electrolyte layer 112 is disposed on the inner surface side of the support 116, and the air electrode layer 114 is disposed on the inner surface side of the electrolyte layer 112. The intermediate layer 113 is disposed on the inner surface side of the electrolyte layer 112 and on the outer surface side of the air electrode layer 114 (that is, between the electrolyte layer 112 and the air electrode layer 114).

  The support 116 is a layer that functions as a fuel electrode while supporting the other layers (the electrolyte layer 112, the intermediate layer 113, and the air electrode layer 114) constituting the single cell 110. The support body 116 includes a porous portion 116a, a dense portion 116b, and an intermediate portion 116c, all of which are substantially cylindrical portions. The porous portion 116a constitutes the vicinity of the center of the support 116 in the Z-axis direction, the dense portion 116b constitutes the vicinity of both ends of the support 116, and the intermediate portion 116c includes the porous portion 116a and each of the dense portions 116b. The part between. That is, the porous portion 116a, the dense portion 116b, and the intermediate portion 116c are arranged so as to be aligned with each other in the Z-axis direction.

  In the present embodiment, the porous portion 116a, the dense portion 116b, and the intermediate portion 116c of the support 116 are made of at least a material having the same composition, specifically, a mixture of Ni and YSZ and a mixture of Ni and GDC. One is formed. Since the porous portion 116a, the dense portion 116b, and the intermediate portion 116c of the support 116 all contain Ni, they have conductivity.

  The porous portion 116a, the dense portion 116b, and the intermediate portion 116c of the support 116 have different porosities. The porosity of the porous portion 116a is, for example, about 40 to 60%, the porosity of the dense portion 116b is, for example, about 0 to 5%, and the porosity of the intermediate portion 116c is, for example, about 10 to 20%. is there. That is, the porosity of the dense portion 116b is lower than the porosity of the porous portion 116a. The porous portion 116a has gas permeability, while the dense portion 116b does not have gas permeability. Further, the porosity of the intermediate portion 116c is lower than the porosity of the porous portion 116a and higher than the porosity of the dense portion 116b. The intermediate portion 116c has gas permeability, but the degree of gas permeability is lower than the degree of gas permeability of the porous portion 116a. In addition, it is preferable that the difference of the porosity of two parts which mutually adjoin among each part which comprises the support body 116 is 20% or less. The porosity of the porous portion 116a is preferably 40% or more in order to ensure a certain degree of gas permeability, and preferably 60% or less in order to ensure a certain degree of structural strength.

  The electrolyte layer 112 is formed of at least one of YSZ (yttria stabilized zirconia), ScSZ (scandia stabilized zirconia), GDC (gadolinium doped ceria), and LSGM (lanthanum strontium gallium magnesium). Thus, the single cell 110 of this embodiment is a solid oxide fuel cell (SOFC) using these solid oxides as an electrolyte. The porosity of the electrolyte layer 112 is lower than the porosity of the porous portion 116 a of the support 116. That is, the electrolyte layer 112 is a relatively dense layer.

  The air electrode layer 114 is made of, for example, a perovskite oxide (for example, LSCF (lanthanum strontium cobalt iron), LSM (lanthanum strontium manganese), LNF (lanthanum nickel iron), etc.). The porosity of the air electrode layer 114 is higher than the porosity of the electrolyte layer 112. That is, the air electrode layer 114 is a relatively porous layer. The space facing the inner surface of the air electrode layer 114 (the hollow space of the single cell 110) constitutes an oxidant gas flow path 166 through which the oxidant gas OG (for example, air) flows.

  The intermediate layer 113 is formed of a mixed material (for example, a mixed material of YSZ and LSM) of the material forming the electrolyte layer 112 and the material forming the air electrode layer 114 described above. The porosity of the intermediate layer 113 is higher than the porosity of the electrolyte layer 112. That is, the intermediate layer 113 is a relatively porous layer.

  As shown in FIGS. 2 and 4, in this embodiment, the length of each layer constituting the single cell 110 in the Z direction is the longest in the support 116, the next longer in the electrolyte layer 112 and the intermediate layer 113, and the air The polar layer 114 is the shortest. That is, as shown in FIG. 4, the lower ends of the electrolyte layer 112 and the intermediate layer 113 are positioned on the upper end side from the lower end of the support 116, and the lower end of the air electrode layer 114 is on the upper end side of the lower end of the electrolyte layer 112. Is located. The same applies to the configuration on the upper end side of the single cell 110.

(Configuration of connecting member 200)
As shown in FIGS. 1 and 2, each connecting member 200 fixes the single cell 110 to the metal plate 310 and also connects the single cell 110 to the oxidant gas pipe 320 (the oxidant gas supply pipe 320 i and the oxidant gas discharge pipe). 320o). Hereinafter, with reference to FIG. 4, the configuration of the connection member 200 on the lower side (side to which the oxidant gas supply pipe 320 i is connected) will be described. The configuration of the upper connecting member 200 is the same.

  As shown in FIG. 4, the connecting member 200 includes a joint fitting 210, a gas seal composite 240, a pressing fitting 230, and a fixing fitting 220.

  The joint fitting 210 is a joint for connecting the oxidant gas pipe 320 (oxidant gas supply pipe 320i) to the single cell 110, and is formed of, for example, a metal such as SUS316. The joint fitting 210 includes a flange portion 213, a substantially cylindrical first tubular portion 211 extending upward from the flange portion 213, and a substantially cylindrical second tubular portion 212 extending downward from the flange portion 213. Screws are formed on the outer peripheral surfaces of the first cylindrical portion 211 and the second cylindrical portion 212. The end of the single cell 110 is inserted into the hollow space of the first tubular portion 211 in a state where it abuts against the flange portion 213. Note that the end portion of the single cell 110 may not be in contact with the flange portion 213. An oxidant gas supply pipe 320i is screwed to the second cylindrical portion 212. Thus, the internal space of the oxidant gas supply pipe 320 i communicates with the oxidant gas flow path 166 configured by the hollow space of the single cell 110 via the internal space of the joint fitting 210. Further, the joint fitting 210 is fixed to the metal plate 310 at the flange portion 213.

  The gas seal composite 240 is a member for sealing between the space in which the oxidant gas OG flows and the space in which the fuel gas FG flows, and the end portion of the single cell 110 (the support body 116 is configured by the dense portion 116b. Of the first cylindrical portion 211 of the joint fitting 210 and the outer peripheral surface of the fitting fitting 210. The gas seal composite 240 is disposed between the first and second gasket members 241 and 242 and the annular first and second gasket members 241 and 242 fitted on the outer peripheral side of the end portion of the unit cell 110. An annular glass seal portion 243 is included. The first and second gasket members 241 and 242 are heat resistant gasket members formed of, for example, expanded graphite. The second gasket member 242 is disposed so as to contact the flange portion 213 of the joint fitting 210, and the first gasket member 241 is disposed above the second gasket member 242 with the glass seal portion 243 interposed therebetween. Further, the glass seal portion 243 is formed of, for example, borosilicate glass, and softens and adheres to the surroundings at the environmental temperature (for example, 550 to 1000 ° C.) in which the single cell 110 is used. A gas sealing function is exhibited together with the members 241 and 242.

  The press fitting 230 is a substantially cylindrical member for pressing the gas seal composite 240, and is formed of a metal such as SUS316, for example. The pressing metal fitting 230 is fitted on the outer peripheral side of the end portion of the single cell 110 and is in contact with the upper end of the gas seal composite 240 (the upper end of the first gasket member 241).

  The fixing bracket 220 is a cylindrical member for fixing the connection member 200, and is formed of, for example, a metal such as SUS316. The fixture 220 includes a substantially cylindrical pressing plate 221 and a cylindrical portion 222 extending downward from the outer peripheral end of the pressing plate 221. The lower surface of the pressing plate 221 is in contact with the upper surface of the pressing fitting 230. A screw is formed on the inner peripheral surface of the cylindrical portion 222. When the screw on the inner peripheral surface of the cylindrical portion 222 of the fixing bracket 220 and the screw on the outer peripheral surface of the first cylindrical portion 211 of the joint bracket 210 are screwed together and tightened, the pressing plate 221 moves the pressing bracket 230 downward. The pressing metal fitting 230 presses the gas seal composite 240 downward. Thereby, the 1st and 2nd gasket members 241 and 242 which constitute gas seal composite 240 are compressed, and the gas seal property of gas seal composite 240 is secured.

A-2. Operation of the single cell module 102:
As shown in FIG. 1 and FIG. 2, when the fuel gas FG is supplied to the fuel gas flow path 176 defined by the two metal plates 310, the supplied fuel gas FG is placed on the outermost side of the single cell 110. It enters and diffuses into the disposed porous support 116 (mainly the porous portion 116a of the support 116). Further, when the oxidant gas OG is supplied from the oxidant gas supply pipe 320 i to the oxidant gas flow path 166 constituted by the hollow space of the single cell 110, the supplied oxidant gas OG is the most It enters and diffuses into the porous air electrode layer 114 (and the porous intermediate layer 113 adjacent thereto) disposed inside. When the unit cell 110 is heated to a predetermined temperature (for example, about 550 ° C. to 1000 ° C.) while supplying the fuel gas FG and the oxidant gas OG, hydrogen and oxidant gas OG contained in the fuel gas FG are supplied. Electrical energy is generated by an electrochemical reaction with the contained oxygen. The electric energy generated in the single cell 110 is taken out by an external circuit that connects the support 116 and the air electrode layer 114. The oxidant gas OG that has passed through the oxidant gas flow path 166 is discharged to the oxidant gas discharge pipe 320o.

A-3. Manufacturing method of the single cell module 102:
Next, a method for manufacturing the single cell module 102 will be described. FIG. 5 is a flowchart showing a method for manufacturing the single cell module 102 in the present embodiment. First, a material for forming each part (porous part 116a, dense part 116b, intermediate part 116c) constituting the support 116 is prepared (S102). In this embodiment, the material for forming each part constituting the support 116 is a material having the same composition (for example, a 60:40 wt% mixture of NiO and YSZ). However, the materials for forming the portions constituting the support 116 are different from each other in the amount of pore former (for example, organic beads) added. A relatively large amount (for example, 20 wt%) of a pore former is added to the material for forming the porous portion 116a, and a relatively small amount (for example, 5 wt.%) Is added to the material for forming the intermediate portion 116c. %) The pore former is added, and the pore former is not added to the material for forming the dense portion 116b (or a smaller amount of pore former than the intermediate portion 116c is added).

  Next, a support body molded body 60 is produced by sequentially filling and pressurizing a material for forming each part of the support body 116 into a rubber mold (S104). FIG. 6 is an explanatory view showing a method for producing the support molded body 60. When the support molded body 60 is manufactured, as shown in FIG. 6A, a rubber mold frame in which a rubber mold 53 is disposed on a flat base 51 is used. The rubber mold 53 has a substantially hollow cylindrical inner hole 55 corresponding to the outer shape of the support 116, and the inner hole 55 has a substantially cylindrical shape corresponding to the shape of the hollow space of the support 116. A center pin 57 is arranged. Thus, a substantially hollow cylindrical mold hole 59 is formed between the inner peripheral surface of the inner hole 55 and the outer peripheral surface of the center pin 57.

  When producing the support molded body 60, first, a material 61 for forming the dense portion 116b of the support 116 is filled in the mold hole 59 of the rubber mold 53 (FIG. 6A). Next, the mold hole 59 is filled with a material 62 for forming the intermediate portion 116c of the support 116 (FIG. 6B). Thereafter, similarly, the material 63 for forming the porous portion 116a of the support 116 is filled in the mold hole 59 (FIG. 6C), and then the support is placed in the mold hole 59. The material 62 for forming the intermediate portion 116c of the body 116 is refilled (FIG. 6D), and then the material 61 for forming the dense portion 116b of the support 116 is placed in the mold hole 59. Fill again (FIG. 6E).

  Next, as shown in FIG. 6 (f), the upper mold 52 is installed on the upper part of the rubber mold 53. A substantially cylindrical convex portion is formed on the lower surface of the upper mold 52. When the upper mold 52 is installed on the upper portion of the rubber mold 53, the convex portion of the upper mold 52 is inserted into the mold hole 59. Then, it contacts the upper material 61 filled in the mold hole 59. In this state, press molding is performed by applying a predetermined pressure P (for example, 100 MPa) from the outside of the rubber mold 53. By such press molding, a support molded body 60 shown in FIG. 6G is produced.

  Next, the calcined body of the support molded body 60 is manufactured by performing heat treatment on the manufactured support molded body 60 under a predetermined condition (for example, 1100 ° C., 1 hour) in the atmosphere ( S106).

  Next, a slurry of a material for forming the electrolyte layer 112 (for example, YSZ) is applied to the calcined body of the support molded body 60 by dip coating (S108). At this time, since the outer peripheral surface of the calcined body of the support molded body 60 is masked with a masking tape, the slurry of the forming material of the electrolyte layer 112 is applied only to the inner surface of the calcined body of the support molded body 60. . Furthermore, a slurry of the formation material of the intermediate layer 113 (for example, a mixed material of YSZ and LSM) is applied to the inner surface of the applied formation material of the electrolyte layer 112 by a dip coating method in the same masked state ( S110).

  Next, the support molded body 60 to which the forming material of the electrolyte layer 112 and the intermediate layer 113 is applied is fired in the air under predetermined conditions (for example, 1400 ° C., 2 hours) (S112). Thereby, the forming material of the support 116, the electrolyte layer 112, and the intermediate layer 113 is simultaneously fired, and a joined body (hereinafter referred to as “first joined body”) composed of the support 116, the electrolyte layer 112, and the intermediate layer 113. ") Is produced.

  Next, a slurry of a material for forming the air electrode layer 114 (for example, LSM) is applied to the inner surface of the first bonded body by a dip coating method with the outer peripheral surface of the first bonded body masked (S114). ). Next, the first bonded body to which the material for forming the air electrode layer 114 is applied is fired in the atmosphere under predetermined conditions (for example, 1200 ° C., 2 hours) (S116). As a result, the forming material of the air electrode layer 114 is fired, and a joined body composed of the first joined body and the air electrode layer 114 (hereinafter referred to as “second joined body”), that is, a single cell 110 is manufactured. Is done.

  Next, the connection member 200 is attached to both ends of the single cell 110, and glass heat treatment is performed in nitrogen under predetermined conditions (for example, 550 ° C., 5 hours) (S118). Thereby, the sealing performance by the gas seal composite 240 is ensured, and the manufacture of the single cell module 102 composed of the single cell 110 and the two connection members 200 is completed.

A-4. Effects of this embodiment:
As described above, the single cell 110 constituting the single cell module 102 of the present embodiment includes the support 116, the electrolyte layer 112, and the air electrode layer 114. The support 116 has a cylindrical shape with both ends open in the Z-axis direction, and is disposed so as to be aligned with the porous portion 116a having gas permeability and conductivity, and the porous portion 116a in the Z-axis direction. And a dense portion 116b having a lower porosity than 116a and functions as a fuel electrode. The electrolyte layer 112 is disposed on the inner surface side of the support 116, has a cylindrical shape extending in the Z-axis direction, and has a lower porosity than the porous portion 116a. The air electrode layer 114 is disposed on the inner surface side of the electrolyte layer 112, has a cylindrical shape extending in the Z-axis direction, and has a higher porosity than the electrolyte layer 112. According to the single cell 110 of the present embodiment having such a configuration, the dense member 116b is joined to the connecting member 200 while maintaining the gas permeability of the support 116 due to the presence of the porous portion 116a. The occurrence of gas leakage and breakage of the support 116 can be suppressed.

  In the single cell 110 of this embodiment, since the electrolyte layer 112 is disposed on the inner surface side of the support 116, the electrolyte layer 112 is compared with the configuration in which the electrolyte layer 112 is disposed on the outer surface side of the support 116. Generation of scratches and pinholes in the layer 112 can be suppressed, and occurrence of cross leaks caused by such scratches and pinholes can be suppressed.

  In the unit cell 110 of the present embodiment, the support 116 further includes an intermediate portion 116c. The intermediate portion 116c is disposed between the porous portion 116a and the dense portion 116b in the Z-axis direction, has a lower porosity than the porous portion 116a, and has a higher porosity than the dense portion 116b. Therefore, according to the single cell 110 of the present embodiment, due to the presence of the intermediate portion 116c, the porosity gradient between the porous portion 116a and the dense portion 116b is reduced while maintaining the porosity of the porous portion 116a high. It is possible to suppress the occurrence of breakage at the interface of each part constituting the support 116.

  In the single cell 110 of the present embodiment, the material for forming the porous portion 116a, the material for forming the dense portion 116b, and the material for forming the intermediate portion 116c have the same composition. Therefore, according to the single cell 110 of the present embodiment, the thermal expansion coefficient of each part constituting the support 116 can be made equal, and the support due to the difference in thermal expansion between the parts during firing or power generation operation. The occurrence of breakage 116 can be suppressed.

  Further, in the unit cell 110 of the present embodiment, the dense portions 116b are disposed at both ends of the support body 116 in the Z-axis direction. Therefore, according to the single cell 110 of the present embodiment, the connection with the connection member 200 or the like for connection with the oxidant gas pipe 320 is performed at the dense portions 116b disposed at both ends of the support body 116, thereby connecting While optimizing the arrangement of the members 200 and the like, it is possible to suppress the occurrence of gas leakage and breakage of the support 116.

  In the unit cell 110 of this embodiment, the dense portion 116b has conductivity in addition to the porous portion 116a and the intermediate portion 116c. Therefore, according to the single cell 110 of the present embodiment, it is possible to secure the area of the conductive portion of the support body 116 while suppressing the occurrence of breakage of the end portion of the support body 116. In addition, according to the single cell 110 of the present embodiment, terminals can be easily taken out from the dense portions 116b having conductivity disposed at both ends of the support 116, thereby simplifying the configuration and reducing the size of the apparatus. Can be realized.

  In the single cell 110 of the present embodiment, the lower end (or upper end) of the electrolyte layer 112 is located on the upper end side (or lower end side) from the lower end (or upper end) of the support 116 in the Z-axis direction. The lower end (or upper end) of the air electrode layer 114 is located on the upper end (or lower end side) from the lower end (or upper end) of the electrolyte layer 112. Therefore, according to the single cell 110 of this embodiment, it is possible to secure a distance between the dense portion 116b having conductivity and the air electrode layer 114, and to suppress the occurrence of a short circuit between them.

  The single cell 110 of this embodiment further includes an intermediate layer 113. The intermediate layer 113 is disposed on the inner surface side of the electrolyte layer 112 and on the outer surface side of the air electrode layer 114, has a higher porosity than the electrolyte layer 112, and has a cylindrical shape extending in the Z-axis direction. Therefore, according to the single cell 110 of the present embodiment, the electrolyte layer 112 and the air electrode layer 114 can be bonded via the porous intermediate layer 113, and the relatively dense electrolyte layer 112 and the relatively porous layer can be bonded. Compared with a configuration in which the air electrode layer 114 is in contact with each other, the bonding property between the electrolyte layer 112 and the air electrode layer 114 can be improved.

  Further, in the single cell 110 of this embodiment, the intermediate layer 113 is formed of a mixed material of the material constituting the electrolyte layer 112 and the material constituting the air electrode layer 114. Therefore, according to the single cell 110 of the present embodiment, the difference in thermal expansion coefficient between the electrolyte layer 112 and the air electrode layer 114 can be reduced, and delamination occurs due to the difference in thermal expansion during firing or power generation operation. Can be suppressed.

  In the single cell 110 of the present embodiment, the electrolyte layer 112 is formed of at least one of YSZ, ScSZ, GDC, and LSGM. Therefore, according to the single cell 110 of this embodiment, the power generation reactivity can be improved.

  In the single cell 110 of the present embodiment, the porous portion 116a is formed of at least one of a mixture of Ni and YSZ and a mixture of Ni and GDC. Therefore, according to the single cell 110 of this embodiment, the power generation reactivity can be improved.

  Further, in the manufacturing method of the single cell module 102 (single cell 110) of the present embodiment, the material of the support 116 and the material of the electrolyte layer 112 are simultaneously baked to form the first of the support 116 and the electrolyte layer 112. 1st baking process (S112) which produces one joined body, and a 1st joined body and an air electrode by arrange | positioning and baking the formation material of the air electrode layer 114 in the inner surface side in a 1st joined body. A second baking step (S116) for producing a second bonded body with the layer 114. Therefore, according to the method for manufacturing the single cell module 102 (single cell 110) of the present embodiment, the air electrode layer 114 is separated from the first baking step in which the support 116 and the electrolyte layer 112 are simultaneously fired. Since the porosity of the air electrode layer 114 can be suppressed from being excessively reduced by the production in the firing step 2, it is possible to suppress a decrease in gas permeability in the air electrode layer 114 and to prevent the three-layer interface. Reduction can be suppressed.

  Further, in the manufacturing method of the single cell module 102 (single cell 110) of the present embodiment, the first bonded body has a porosity higher than that of the electrolyte layer 112 in addition to the forming material of the support 116 and the forming material of the electrolyte layer 112. Is a joined body of the support 116, the electrolyte layer 112, and the intermediate layer 113, which is formed by simultaneously firing the material for forming the intermediate layer 113 having a high thickness. The second firing step is performed by the dip coating method. The process of apply | coating the formation material of the air electrode layer 114 to the inner surface side in 1 joining body is included. Therefore, according to the manufacturing method of the single cell module 102 (single cell 110) of this embodiment, the applicability of the forming material of the air electrode layer 114 at the time of dip coating is improved by the presence of the relatively porous intermediate layer 113. Can be improved.

A-5. Performance evaluation:
Examples and comparative examples of a plurality of single cell modules having different configurations were produced, and various performance evaluations were performed. Hereinafter, the performance evaluation performed will be described. In the following description, components that are not the same in configuration as the above-described embodiment may be denoted by the same reference numerals for easy understanding.

A-5-1. Evaluation of Gas Leakage Suppression Performance at the Joint Location of Single Cell 110 and Connection Member 200:
(Production of Example 1 of the single cell module 102)
As a material for forming the porous portion 116a, the dense portion 116b, and the intermediate portion 116c of the support 116, a 60:40 wt% mixture of NiO and YSZ was prepared. 20 wt% pore former (organic beads) is added to the forming material of the porous portion 116 a, 5 wt% pore forming material is added to the forming material of the intermediate portion 116 c, and the forming material is formed to the dense portion 116 b. No pore material was added. The forming material of each part of the support body 116 was sequentially filled into a rubber mold and pressed at 100 MPa to prepare a support body molded body 60 (see FIG. 6). The obtained support body molded body 60 was heat-treated at 1100 ° C. for 1 hour in the air to obtain a calcined body of the support body molded body 60. A slurry of YSZ, which is a material for forming the electrolyte layer 112, was applied to the inner surface of the calcined body of the obtained support molded body 60 by a dip coating method. Furthermore, a slurry of a material obtained by adding 20 wt% of organic beads as a pore-forming material to a 50:50 vol% mixture of YSZ and LSM, which are forming materials of the intermediate layer 113, is applied onto the YSZ slurry by a dip coating method. did. Thereafter, firing was performed in air at 1400 ° C. for 2 hours to obtain a joined body (first joined body) composed of the support 116, the electrolyte layer 112, and the intermediate layer 113. Furthermore, a single cell 110 is formed by applying a slurry of LSM, which is a material for forming the air electrode layer 114, to the inner surface of the first bonded body by a dip coating method, and performing firing at 1200 ° C. for 2 hours in the atmosphere. Got. At both ends of the obtained unit cell 110, a gas seal composite 240 composed of first and second gasket members 241 and 242 made of expanded graphite and a glass seal portion 243 and a fitting fitting 210 formed of SUS316 are provided. Example 1 of the single cell module 102 was obtained by joining the connecting member 200 provided and performing glass heat treatment at 550 ° C. for 5 hours in nitrogen.

(Preparation of Comparative Example 1 of the single cell module 102)
Compared with Example 1 described above, Comparative Example 1 of the single cell module 102 is such that the entire support 116 is configured by the porous portion 116a, and the gas seal composite 240 does not include the glass seal portion 243. This is different from the point that only the expanded graphite gasket member 241 is configured. That is, in the production of Comparative Example 1, a 60:40 wt% mixture of NiO and YSZ (with 20 wt% pore former added) was prepared as a material for forming the support 116, and this material was used as a rubber mold. The support molded body 60 is prepared by filling in and pressurizing at 100 MPa, and the calcined body of the support molded body 60 is subjected to heat treatment at 1100 ° C. for 1 hour in the atmosphere. The YSZ slurry that is the material for forming the electrolyte layer 112 is applied to the inner surface of the calcined body of the support molded body 60 by the dip coating method, and the YSZ that is the material for forming the intermediate layer 113 is further applied on the YSZ slurry. A slurry of a material obtained by adding 20 wt% of organic beads as a pore former to a 50:50 vol% mixture of LSM and LSM was applied by dip coating, and baked at 1400 ° C. for 2 hours in the atmosphere. The first joined body is obtained by applying a slurry of LSM, which is a material for forming the air electrode layer 114, to the inner surface of the first joined body by a dip coating method, and is heated at 1200 ° C. for 2 hours in the atmosphere. A single cell 110 was obtained by firing. The connection member 200 provided with the gasket member 241 made of expanded graphite and the joint fitting 210 formed of SUS316 was joined to both ends of the obtained single cell 110 to obtain Comparative Example 1 of the single cell module 102. A gas seal composite 240 composed of first and second gasket members 241 and 242 made of expanded graphite and a glass seal portion 243 is attached to both ends of the unit cell 110 of Comparative Example 1, and is 550 ° C. in nitrogen. When the glass heat treatment for 5 hours was performed, the single cell 110 (support 116) was broken by the compressive stress due to melting of the glass.

(First gas leak test)
A first gas leak test was performed using Example 1 and Comparative Example 1 of the single cell module 102. One end of each single cell module 102 is sealed with a metal blind, and He gas is supplied from the inside of the connection member 200 at the other end at a pressure of about 0.8 MPaG to leak outside the single cell module 102. The amount of He gas was measured with a soap film flow meter. In Example 1 of the single cell module 102, the amount of He gas was below the detection lower limit, but in Comparative Example 1 of the single cell module 102, a He gas leak of 1 ml / min was detected. From the result of the first gas leakage test, it was confirmed that the occurrence of gas leakage can be suppressed by joining the connecting member 200 with the dense portion 116b of the support 116.

A-5-2. Evaluation of cross leak suppression performance:
(Production of Evaluation Module Example 2)
As a material for forming the porous portion 116a, the dense portion 116b, and the intermediate portion 116c of the support 116, a 60:40 wt% mixture of NiO and YSZ was prepared. 20 wt% pore former (organic beads) is added to the forming material of the porous portion 116 a, 5 wt% pore forming material is added to the forming material of the intermediate portion 116 c, and the forming material is formed to the dense portion 116 b. No pore material was added. The forming material of each part of the support body 116 was sequentially filled into a rubber mold and pressed at 100 MPa to prepare a support body molded body 60 (see FIG. 6). The obtained support body molded body 60 was heat-treated at 1100 ° C. for 1 hour in the air to obtain a calcined body of the support body molded body 60. A slurry of YSZ, which is a material for forming the electrolyte layer 112, is applied to the inner surface of the calcined body of the obtained support molded body 60 by a dip coating method, and is placed directly on a setter for baking and then dried. Then, the bonded body composed of the support 116 and the electrolyte layer 112 was obtained by firing at 1400 ° C. for 2 hours in the air. A connecting member 200 including a gasket member 241 made of expanded graphite and a joint fitting 210 formed of SUS316 was joined to both ends of the obtained joined body to obtain Example 2 of the evaluation module.

(Production of Evaluation Module Comparative Example 2)
In Comparative Example 2 of the evaluation module, compared to Example 2 described above, the electrolyte is not formed on the inner surface side but on the outer surface side of the support member 116 in that the entire support body 116 is constituted by the porous portion 116a. The difference is that the layer 112 is formed. That is, in the production of Comparative Example 2, a 60:40 wt% mixture of NiO and YSZ (with 20 wt% pore former added) was prepared as a material for forming the support 116, and this material was used as a rubber mold. The support molded body 60 is prepared by filling the substrate and pressurizing at 100 MPa, and subjecting the support molded body 60 to heat treatment at 1100 ° C. for 1 hour in the air, thereby calcining the support molded body 60. The slurry of YSZ, which is a material for forming the electrolyte layer 112, is applied to the outer surface of the calcined body of the support molded body 60 by the dip coating method, and is directly placed on a setter for baking and then dried. By firing at 1400 ° C. for 2 hours in the atmosphere, a joined body composed of the support 116 and the electrolyte layer 112 is obtained, and expanded graphite gasket members 241 and SUS316 are used at both ends of the joined body. Bonding the connecting member 200 and a joint fitting 210 has been made to obtain a comparative example 2 of the evaluation module.

(Second gas leak test)
A second gas leak test was performed using the evaluation module of Example 2 and Comparative Example 2. One end of each evaluation module is sealed with a metal blind, He gas is supplied at a pressure of about 0.8 MPaG from the inside of the connection member 200 at the other end, and He leaks to the outside of the evaluation module. The amount of gas was measured with a soap film flow meter. In Example 2 of the evaluation module, the amount of He gas was below the lower limit of detection, but in Comparative Example 2 of the evaluation module, a He gas leak of about 10 ml / min was detected. When Comparative Example 2 of the evaluation module was immersed in water containing red ink in order to identify the location where the gas leaked, several spots of red ink were found on the surface of the electrolyte layer 112. In Comparative Example 2 of the evaluation module, since the electrolyte layer 112 is formed on the outer surface side of the support 116, it is considered that scratches and pinholes were generated in the electrolyte layer 112. Such scratches and pinholes in the electrolyte layer 112 are not preferable because they cause cross leaks. On the other hand, when Example 2 of the evaluation module was examined in the same manner, it was confirmed that there was no soaking of red ink, and the occurrence of scratches and pinholes in the electrolyte layer 112 causing cross leak was suppressed. . From the result of the second gas leak test, it was confirmed that the occurrence of cross leak can be suppressed by forming the electrolyte layer 112 on the inner surface side of the support 116.

B. Variations:
The technology disclosed in the present specification is not limited to the above-described embodiment, and can be modified into various forms without departing from the gist thereof. For example, the following modifications are possible.

  The configuration of the single cell module 102 in the above embodiment is merely an example, and various modifications can be made. For example, in the above embodiment, the dense portion 116b of the support 116 is conductive, but the dense portion 116b may not be conductive. In the above embodiment, the dense portions 116b are disposed at both ends of the support body 116. However, the dense portions 116b may be disposed only at one end portion of the support body 116. It may be arranged at a portion other than the end of the support 116. In the above embodiment, the length of each layer constituting the single cell 110 in the Z direction is the longest in the support 116, the next in the electrolyte layer 112 and the intermediate layer 113, and the shortest in the air electrode layer 114. The relationship between these lengths (the positional relationship between the end portions of these layers) can be arbitrarily changed. For example, the length of the electrolyte layer 112 and the intermediate layer 113 may be the same as the length of the support 116. Moreover, in the said embodiment, although each layer which comprises the single cell 110 is taken as the substantially cylindrical shape of both ends open, each layer may be a single-end open shape, and the cross-sectional shape of each layer is shapes other than a circle ( For example, an ellipse) may be used.

  Moreover, in the said embodiment, although the support body 116 is provided with the intermediate part 116c, the support body 116 may not be provided with the intermediate part 116c, and may be comprised from the porous part 116a and the precise | minute part 116b. In the above embodiment, the single cell 110 includes the intermediate layer 113, but the single cell 110 does not include the intermediate layer 113, and includes the support 116, the electrolyte layer 112, and the air electrode layer 114. Also good.

  Moreover, the material which forms each member in the said embodiment is an illustration to the last, and each member may be formed with another material. For example, in the above embodiment, the forming material of the porous portion 116a, the forming material of the dense portion 116b, and the forming material of the intermediate portion 116c constituting the support 116 have the same composition, but at least of these forming materials One may have a different composition. In the above embodiment, the intermediate layer 113 is formed of a mixed material of the material forming the electrolyte layer 112 and the material forming the air electrode layer 114, but the forming material of the intermediate layer 113 can be arbitrarily changed. It is.

  Moreover, the manufacturing method of the single cell module 102 in the said embodiment is an example to the last, and can be variously modified. FIG. 7 is a flowchart showing a flow of a manufacturing method of the single cell module 102 in the modification. In the manufacturing method of the modified example shown in FIG. 7, the step (S117) of deleting the end of the second joined body is performed after the production of the second joined body (S116), as shown in FIG. This is different from the manufacturing method of the embodiment. In this deletion step, the end portion of the second bonded body is deleted by cutting or polishing, and the position of the end of the support 116 and the position of the end of the air electrode layer 114 in the Z-axis direction are aligned. According to the manufacturing method of such a modification, the size of the single cell 110 in the Z-axis direction can be reduced while suppressing a decrease in power generation capacity of the manufactured single cell 110. Moreover, according to the manufacturing method of such a modification, the wiring management at the time of comprising a stack by the several single cell 110 manufactured can be made easy.

  Moreover, in the said embodiment, although the single cell 110 is used as the single cell module 102, the single cell 110 may be used as another form. FIG. 8 is an explanatory diagram showing a modification in which a plurality of single cells 110 constitute the fuel cell stack 100. A fuel cell stack 100 shown in FIG. 8 has a configuration in which an integrated body 10 in which a plurality of single cells 110 are integrated is stacked in three stages in the vertical direction. Each integrated body 10 has a configuration in which the vicinity of both ends of a plurality of single cells 110 arranged substantially parallel to each other is held by a holding member 22 made of, for example, ceramics. Each single cell 110 is joined to the holding member 22 via a sealing material 31 containing, for example, glass. A plate member 28 made of, for example, ceramics is disposed on the upper surface of the uppermost holding member 22. Also in the fuel cell stack 100 configured as shown in FIG. 8, if the support body 116 is configured by the dense portion 116 b at the joint portion (both ends in the example of FIG. 8) of each single cell 110 with the holding member 22. The occurrence of breakage of the single cell 110 can be suppressed.

  In the above-described embodiment, the SOFC that generates power using the electrochemical reaction between hydrogen contained in the fuel gas FG and oxygen contained in the oxidant gas OG is targeted. A metal having a structure in which a metal (for example, iron) is disposed on the outer peripheral surface, hydrogen is generated by a reaction between the metal and water vapor by supplying water vapor to the outside of the single cell 110, and the generated hydrogen is supplied to the support 116. The present invention can be similarly applied to an air battery system.

  Further, in the above-described embodiment, the SOFC that generates power using the electrochemical reaction between the hydrogen contained in the fuel gas FG and the oxygen contained in the oxidant gas OG is targeted. The present invention is also applicable to an electrolytic single cell that is the minimum unit of a solid oxide electrolytic cell (SOEC) that generates hydrogen by using a reaction, and an electrolytic cell stack including a plurality of electrolytic single cells. The configuration of the electrolytic cell is well-known as described in, for example, Japanese Patent Application Laid-Open No. 2014-207120 and will not be described in detail here. However, the configuration is generally the same as that of the fuel cell single cell 110 in the above-described embodiment. It is the composition. During the operation of the electrolysis unit cell, a voltage is applied between both electrodes so that the air electrode layer 114 is positive (anode) and the support 116 is negative (cathode), and water vapor as a source gas is supplied. Is done. Thereby, an electrolysis reaction of water occurs in each electrolytic single cell, and hydrogen gas is generated in the support 116. Even in the electrolytic single cell having such a configuration, if the support body 116 has the same structure as that of the above embodiment, the occurrence of gas leakage and breakage of the support body 116 can be suppressed.

10: Accumulated body 22: Holding member 28: Plate member 31: Sealing material 51: Base 52: Upper mold 53: Rubber mold 55: Internal hole 57: Center pin 59: Form hole 60: Support body molded body 61: Material 62: Material 63: Material 100: Fuel cell stack 102: Fuel cell single cell module 110: Fuel cell single cell 112: Electrolyte layer 113: Intermediate layer 114: Air electrode layer 116: Support 116a: Porous portion 116b: Dense Part 116c: Intermediate part 166: Oxidant gas flow path 176: Fuel gas flow path 200: Connection member 210: Joint metal fitting 211: First cylindrical part 212: Second cylindrical part 213: Gutter part 220: Fixing metal part 221: Press plate 222: Cylindrical portion 230: Press fitting 240: Gas seal composite 241: First gasket member 242: Second gas Tsu Preparative member 243: glass seal portion 310: metal plate 320i: oxidizing gas supplying pipe 320O: oxidizing gas discharge pipe

Claims (13)

In an electrochemical reaction single cell,
A cylindrical portion having both ends open in the first direction and having a gas permeable and conductive porous portion, and arranged in line with the porous portion in the first direction. A dense part having a low rate, and a support functioning as a fuel electrode;
An electrolyte layer disposed on the inner surface side of the support and extending in the first direction, having a lower porosity than the porous portion;
An electrochemical reaction unit cell comprising: an air electrode that is disposed on an inner surface side of the electrolyte layer and extends in the first direction and has a higher porosity than the electrolyte layer. The electrochemical reaction single cell according to claim 1,
The support is further disposed between the porous portion and the dense portion in the first direction, and has a lower porosity than the porous portion and a higher porosity than the dense portion. An electrochemical reaction single cell comprising: The electrochemical reaction single cell according to claim 2,
The electrochemical reaction unit cell, wherein the porous portion forming material, the dense portion forming material, and the intermediate portion forming material have the same composition. In the electrochemical reaction single cell as described in any one of Claim 1- Claim 3,
The electrochemical reaction unit cell, wherein the dense portion is disposed at at least one end of the support in the first direction. The electrochemical reaction single cell according to claim 4,
The electrochemical reaction unit cell, wherein the dense portion has conductivity. The electrochemical reaction single cell according to claim 5,
In the first direction,
One end of the electrolyte layer is at the same position as one end of the support, or is located on the other end side from one end of the support,
One end of the air electrode is located on the other end side from one end of the electrolyte layer. The electrochemical reaction single cell according to any one of claims 1 to 6, further comprising:
It is disposed on the inner surface side of the electrolyte layer and on the outer surface side of the air electrode, and has a cylindrical intermediate layer that has a higher porosity than the electrolyte layer and extends in the first direction. Electrochemical reaction single cell. The electrochemical reaction single cell according to claim 7,
The electrochemical reaction unit cell, wherein the intermediate layer is made of a mixed material of a material constituting the electrolyte layer and a material constituting the air electrode. In the electrochemical reaction single cell according to any one of claims 1 to 8,
The electrochemical reaction unit cell, wherein the electrolyte layer is formed of at least one of YSZ, ScSZ, GDC, and LSGM. The electrochemical reaction single cell according to any one of claims 1 to 9,
The electrochemical reaction unit cell, wherein the porous portion is formed of at least one of a mixture of Ni and YSZ and a mixture of Ni and GDC. A cylindrical portion having both ends open in the first direction and having a gas permeable and conductive porous portion, and arranged in line with the porous portion in the first direction. A support portion that functions as a fuel electrode, and a cylindrical shape that is disposed on the inner surface side of the support and extends in the first direction, and has a porosity higher than that of the porous portion. A method for producing an electrochemical reaction unit cell comprising: a low electrolyte layer; and an air electrode that is disposed on an inner surface side of the electrolyte layer and extends in the first direction and has a higher porosity than the electrolyte layer. In
A first firing step for producing a first joined body of the support and the electrolyte layer by simultaneously firing the material for forming the support and the material for forming the electrolyte layer;
A second firing step for producing a second joined body of the first joined body and the air electrode by disposing and firing the air electrode forming material on the inner surface side of the first joined body. When,
A method for producing an electrochemical reaction single cell, comprising: The method for producing an electrochemical reaction unit cell according to claim 11,
The second firing step includes a step of applying the air electrode forming material on the inner surface side of the first bonded body by a dip coating method,
The manufacturing method further includes:
After the second firing step, the end of the second bonded body in the first direction is deleted, and the position of the end of the support and the position of the end of the air electrode in the first direction A method for producing an electrochemical reaction single cell, comprising a deletion step of aligning In the manufacturing method of the electrochemical reaction single cell of Claim 11 or Claim 12,
The first bonded body is formed by simultaneously firing an intermediate layer forming material having a higher porosity than the electrolyte layer, in addition to the support forming material and the electrolyte layer forming material. And a joined body of the electrolyte layer and the intermediate layer,
The second firing step includes a step of applying the air electrode forming material on the inner surface side of the joined body of the support, the electrolyte layer, and the intermediate layer by a dip coating method. The manufacturing method of an electrochemical reaction single cell.

Images