JP6748518B2 - Method for manufacturing electrochemical reaction cell - Google Patents

Description

The technology disclosed in this specification relates to a method for manufacturing an electrochemical reaction cell.

BACKGROUND ART Solid oxide fuel cells (hereinafter referred to as “SOFC”) are known as one type of fuel cells that generate electricity using an electrochemical reaction between hydrogen and oxygen. A fuel cell unit cell (hereinafter, referred to as “unit cell”) that constitutes an SOFC includes an electrolyte layer containing a solid oxide, and air facing each other in a predetermined direction (hereinafter, referred to as “arrangement direction”) with the electrolyte layer interposed therebetween. A cathode and an anode, and at least one of the electrolyte layer and the anode comprises a partially stabilized Zr.

In the single cell, a substance contained in the air electrode and a substance contained in the electrolyte layer react to suppress a decrease in power generation performance due to the formation of a high resistance layer. A technique of disposing an intermediate layer in between is known (for example, refer to Patent Document 1). The intermediate layer suppresses the formation of the high resistance layer by suppressing the diffusion of the substance, which is the generation source of the high resistance layer, from the air electrode to the electrolyte layer.

The conventional method for manufacturing a single cell including the intermediate layer as described above is as follows. That is, by performing heat treatment on the electrolyte layer precursor, the fuel electrode precursor, and the intermediate layer precursor at a temperature higher than the phase transition temperature of partially stabilized Zr, a laminate of the electrolyte layer, the fuel electrode, and the intermediate layer is formed. Form. Here, the higher the heat treatment temperature, the higher the density of the intermediate layer in the laminate. The higher the density of the intermediate layer, the higher the ability to suppress the diffusion of the substance, which is the generation source of the high resistance layer, from the air electrode to the electrolyte layer. Therefore, the heat treatment for forming the intermediate layer is generally performed at a temperature higher than the phase transition temperature of the partially stabilized Zr. Next, the laminated body and the air electrode precursor are heat-treated at a temperature lower than the phase transition temperature to manufacture a single cell.

JP2012-181928A

The single cell manufactured by the above-described conventional manufacturing method has a problem that the power generation performance greatly varies (decreases) during operation. That is, in the above-mentioned conventional manufacturing method, when the intermediate layer is formed, the crystal system of partially stabilized Zr is changed from tetragonal crystal with low oxygen ion conductivity by heat treatment at a temperature higher than the phase transition temperature of partially stabilized Zr. Phase transition to cubic with high oxygen ion conductivity. Then, when forming the air electrode, heat treatment at a temperature lower than the phase transition temperature is performed for about 4 hours. However, many crystal systems of partially stabilized Zr contained in the electrolyte layer remain cubic and do not undergo phase transition. On the other hand, the operating temperature of the SOFC equipped with the single cell is generally lower than the phase transition temperature. Therefore, when the SOFC is operated for a long time, many crystal systems of partially stabilized Zr contained in the electrolyte layer of the single cell change from cubic crystal having high oxygen ion conductivity to tetragonal crystal having low oxygen ion conductivity. Transfer. This causes a problem that the power generation performance of the single cell varies greatly during operation. If the fluctuation of the power generation performance of the single cell during operation is large, there arises a problem that the operation control of the SOFC becomes complicated, for example, the operating condition of the SOFC is changed according to the fluctuation of the power generation performance.

It should be noted that such a problem is also common to the method for manufacturing a single cell including a fuel electrode containing a partially stabilized Zr and an intermediate layer. Further, it is a common problem in a method for producing a solid oxide type electrolytic cell (hereinafter, referred to as “SOEC”) that produces hydrogen by utilizing an electrolysis reaction of water. In the present specification, the fuel cell single cell and the electrolytic cell are collectively referred to as an electrochemical reaction single cell.

The present specification discloses a technique capable of solving at least a part of the above-described problems.

The technology disclosed in this specification can be implemented as the following modes.

(1) The method for producing an electrochemical reaction cell disclosed in the present specification includes an electrolyte layer containing a solid oxide, an air electrode and a fuel electrode that face each other in a first direction with the electrolyte layer interposed therebetween, and An intermediate layer disposed between an electrolyte layer and the air electrode, wherein at least one of the electrolyte layer and the fuel electrode contains partially stabilized Zr. A body, a fuel electrode precursor, and an intermediate layer precursor, and a temperature above the phase transition temperature of the partially stabilized Zr in the electrolyte layer precursor, the fuel electrode precursor, and the intermediate layer precursor. Forming a laminate of the electrolyte layer, the fuel electrode, and the intermediate layer by performing the first heat treatment of No. 1, and performing a second heat treatment at a temperature lower than the phase transition temperature on the laminate. Forming the electrochemical reaction cell by performing a third heat treatment at a temperature lower than the phase transition temperature on the laminated body and the air electrode precursor after the second heat treatment for a time period of not less than 2 hours. And According to the method for producing an electrochemical reaction cell, the electrolyte layer precursor, the fuel electrode precursor, and the intermediate layer precursor are subjected to the first heat treatment at a temperature equal to or higher than the phase transition temperature of partially stabilized Zr (zirconia). By being exposed, the intermediate layer can be made dense. On the other hand, the first heat treatment causes the partially stabilized Zr crystal system to undergo a phase transition from a tetragonal crystal with low oxygen ion conductivity to a cubic crystal with high oxygen ion conductivity. However, after that, the second heat treatment at a temperature lower than the phase transition temperature is performed for 10 hours or more on the stacked body, so that the crystal system of partially stabilized Zr undergoes a phase transition from a cubic system to a tetragonal system. By performing the third heat treatment at a temperature lower than the phase transition temperature on the laminated body and the air electrode precursor after the second heat treatment, the electrochemical system in which the crystal system of partially stabilized Zr includes a tetragonal crystal sufficiently. A reaction cell is formed. Moreover, by performing the second heat treatment before the formation of the air electrode, it is possible to suppress a decrease in the gas diffusibility of the air electrode due to the progress of the sintering of the air electrode precursor. As a result, it is possible to manufacture an electrochemical reaction cell in which fluctuations (decrease) in electrochemical reaction performance during operation are reduced while suppressing a decrease in gas diffusibility of the air electrode.

(2) In the method for manufacturing an electrochemical reaction cell, the time for performing the third heat treatment may be shorter than the time for performing the second heat treatment. According to the method for producing an electrochemical reaction cell of the present invention, it is possible to more reliably suppress a decrease in gas diffusibility of the air electrode.

The technology disclosed in the present specification can be realized in various forms, and includes, for example, a fuel cell single cell, a fuel cell stack including a plurality of fuel cell single cells, and a power generation module including a fuel cell stack. A fuel cell system including a power generation module, an electrolysis cell unit, an electrolysis cell stack including a plurality of electrolysis cell units, a hydrogen generation module including an electrolysis cell stack, a hydrogen generation system including a hydrogen generation module, and a manufacturing method thereof, etc. It can be realized in a form.

It is a perspective view showing the appearance composition of fuel cell stack 100 in this embodiment. It is explanatory drawing which shows the XZ cross-section structure of the fuel cell stack 100 in the position of II-II of FIG. It is explanatory drawing which shows the YZ cross section structure of the fuel cell stack 100 in the position of III-III of FIG. It is explanatory drawing which shows the XZ cross-section structure of the two electric power generation units 102 which adjoin each other in the same position as the cross section shown in FIG. It is explanatory drawing which shows the YZ cross-section structure of two adjacent power generation units 102 in the same position as the cross section shown in FIG. 5 is a flowchart showing an example of a method for manufacturing the fuel cell stack 100 according to this embodiment. It is explanatory drawing which shows the outline of the manufacturing method of the single cell 110 among the manufacturing methods of the fuel cell stack 100 in this embodiment. It is explanatory drawing which shows the result of the performance evaluation about each sample.

A. First embodiment:
A-1. Constitution:
(Configuration of Fuel Cell Stack 100)
FIG. 1 is a perspective view showing an external configuration of a fuel cell stack 100 according to the present embodiment, and FIG. 2 is an explanatory diagram showing an XZ sectional configuration of the fuel cell stack 100 at a position II-II in FIG. FIG. 3 is an explanatory diagram showing a YZ sectional configuration of the fuel cell stack 100 at the position III-III in FIG. In each drawing, XYZ axes that are orthogonal to each other for specifying the directions are shown. In the present specification, for convenience, the Z-axis positive direction is referred to as the upward direction, and the Z-axis negative direction is referred to as the downward direction, but the fuel cell stack 100 is actually different from such an orientation. It may be installed. The same applies to FIG. 4 and subsequent figures.

The fuel cell stack 100 includes a plurality of (seven in the present embodiment) power generation units 102 and a pair of end plates 104 and 106. The seven power generation units 102 are arranged side by side in a predetermined array direction (vertical direction in this embodiment). The pair of end plates 104 and 106 are arranged so as to sandwich the assembly including the seven power generation units 102 from above and below.

A plurality of (eight in this embodiment) holes penetrating in the vertical direction are formed at the peripheral edge around the Z direction of each layer (power generation unit 102, end plates 104, 106) forming the fuel cell stack 100. , The holes corresponding to each other formed in each layer communicate with each other in the vertical direction to form a communication hole 108 extending in the vertical direction from one end plate 104 to the other end plate 106. In the following description, the hole formed in each layer of the fuel cell stack 100 to form the communication hole 108 may also be referred to as the communication hole 108.

A bolt 22 extending in the vertical direction is inserted into each communication hole 108, and the fuel cell stack 100 is fastened by the bolt 22 and the nuts 24 fitted on both sides of the bolt 22. As shown in FIGS. 2 and 3, between the nut 24 fitted on one side (upper side) of the bolt 22 and the upper surface of the end plate 104 that constitutes the upper end of the fuel cell stack 100, and the bolt. An insulating sheet 26 is interposed between the nut 24 fitted on the other side (lower side) of 22 and the lower surface of the end plate 106 that constitutes the lower end of the fuel cell stack 100. However, at a location where a gas passage member 27, which will be described later, is provided, between the nut 24 and the surface of the end plate 106, the gas passage member 27 and the insulating sheets arranged on the upper side and the lower side of the gas passage member 27, respectively. 26 and 26 are interposed. The insulating sheet 26 is made of, for example, a mica sheet, a ceramic fiber sheet, a ceramic powder sheet, a glass sheet, a glass ceramic composite agent, or the like.

The outer diameter of the shaft portion of each bolt 22 is smaller than the inner diameter of each communication hole 108. Therefore, a space is secured between the outer peripheral surface of the shaft portion of each bolt 22 and the inner peripheral surface of each communication hole 108. As shown in FIGS. 1 and 2, the fuel cell stack 100 is located near the midpoint of one side (the side on the X-axis positive direction side of the two sides parallel to the Y-axis) on the Z-direction outer periphery. The oxidant gas OG is introduced from the outside of the fuel cell stack 100 into the space formed by the bolt 22 (bolt 22A) and the communication hole 108 into which the bolt 22A is inserted, and the oxidant gas OG is used to generate electricity. It functions as an oxidant gas introduction manifold 161 which is a gas flow path to supply to the unit 102, and is a midpoint of a side opposite to the side (the side on the X-axis negative direction side of the two sides parallel to the Y-axis). The space formed by the bolt 22 (bolt 22B) located in the vicinity and the communication hole 108 into which the bolt 22B is inserted is filled with the oxidant off-gas OOG which is the gas discharged from the air chamber 166 of each power generation unit 102. It functions as an oxidant gas discharge manifold 162 that discharges the fuel cell stack 100 to the outside. In this embodiment, for example, air is used as the oxidant gas OG.

In addition, as shown in FIGS. 1 and 3, in the vicinity of the midpoint of one side (the side on the Y axis positive direction side of the two sides parallel to the X axis) on the outer periphery of the fuel cell stack 100 around the Z direction. The fuel gas FG is introduced from the outside of the fuel cell stack 100 into the space formed by the bolt 22 (bolt 22D) located at the position and the communication hole 108 into which the bolt 22D is inserted, and the fuel gas FG is used for power generation. A bolt 22 that functions as a fuel gas introduction manifold 171 that supplies the unit 102, and is located near the midpoint of the side opposite to the side (the Y-axis negative direction side of the two sides parallel to the X-axis). The space formed by the (bolt 22E) and the communication hole 108 into which the bolt 22E is inserted is provided with the fuel off gas FOG, which is the gas discharged from the fuel chamber 176 of each power generation unit 102, outside the fuel cell stack 100. It functions as a fuel gas discharge manifold 172 for discharging the fuel gas. In the present embodiment, as the fuel gas FG, for example, hydrogen-rich gas obtained by reforming city gas is used.

The fuel cell stack 100 is provided with four gas passage members 27. Each gas passage member 27 has a hollow-cylindrical main body portion 28 and a hollow-cylindrical branch portion 29 branched from the side surface of the main body portion 28. The hole of the branch portion 29 communicates with the hole of the main body portion 28. A gas pipe (not shown) is connected to the branch portion 29 of each gas passage member 27. Further, as shown in FIG. 2, the hole of the main body portion 28 of the gas passage member 27 arranged at the position of the bolt 22A forming the oxidant gas introduction manifold 161 communicates with the oxidant gas introduction manifold 161. The hole of the main body portion 28 of the gas passage member 27 arranged at the position of the bolt 22B forming the oxidant gas discharge manifold 162 communicates with the oxidant gas discharge manifold 162. Further, as shown in FIG. 3, the hole of the main body portion 28 of the gas passage member 27 arranged at the position of the bolt 22D forming the fuel gas introduction manifold 171 communicates with the fuel gas introduction manifold 171. The hole of the main body portion 28 of the gas passage member 27 arranged at the position of the bolt 22E forming the discharge manifold 172 communicates with the fuel gas discharge manifold 172.

(Structure of end plates 104 and 106)
The pair of end plates 104 and 106 are substantially rectangular flat plate-shaped conductive members, and are made of, for example, stainless steel. One end plate 104 is arranged above the power generation unit 102 located at the top, and the other end plate 106 is arranged below the power generation unit 102 located at the bottom. The plurality of power generation units 102 are sandwiched by the pair of end plates 104 and 106 while being pressed. The upper end plate 104 functions as a positive output terminal of the fuel cell stack 100, and the lower end plate 106 functions as a negative output terminal of the fuel cell stack 100.

(Configuration of power generation unit 102)
4 is an explanatory diagram showing an XZ 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. 5 is adjacent to each other at the same position as the cross section shown in FIG. It is an explanatory view showing a YZ section composition of two power generation units 102.

As shown in FIGS. 4 and 5, the power generation unit 102, which is the minimum unit of power generation, includes a unit cell 110, a separator 120, an air electrode side frame 130, an air electrode side current collector 134, and a fuel electrode side frame. 140, a fuel electrode side current collector 144, and a pair of interconnectors 150 that form the uppermost layer and the lowermost layer of the power generation unit 102. The separator 120, the air electrode side frame 130, the fuel electrode side frame 140, and the interconnector 150 have holes around the Z direction around the holes corresponding to the communication holes 108 into which the bolts 22 are inserted.

The interconnector 150 is a substantially rectangular flat plate-shaped conductive member, and is made of, for example, ferritic stainless steel. The interconnector 150 secures electrical continuity between the power generation units 102 and prevents reaction gas from mixing between the power generation units 102. In this embodiment, when the two power generation units 102 are arranged adjacent to each other, one interconnector 150 is shared by the two adjacent power generation units 102. That is, the upper interconnector 150 in a certain power generation unit 102 is the same member as the lower interconnector 150 in another power generation unit 102 adjacent to the upper side of the power generation unit 102. Further, since the fuel cell stack 100 includes the pair of end plates 104 and 106, the power generation unit 102 located at the top in the fuel cell stack 100 does not include the upper interconnector 150, but located at the bottom. The power generation unit 102 does not include the lower interconnector 150 (see FIGS. 2 and 3).

The unit cell 110 includes an electrolyte layer 112, an air electrode (cathode) 114 and a fuel electrode (anode) 116 that face each other in the vertical direction (the arrangement direction of the power generation units 102) with the electrolyte layer 112 interposed therebetween, and the electrolyte layer 112. The intermediate layer 300 disposed between the air electrode 114 and the air electrode 114. The unit cell 110 of the present embodiment is a fuel electrode supporting type unit cell in which the fuel electrode 116 supports the electrolyte layer 112, the intermediate layer 300, and the air electrode 114. The unit cell 110 corresponds to the electrochemical reaction cell in the claims.

The electrolyte layer 112 is a substantially rectangular flat plate-shaped member and contains at least partially stabilized Zr. For example, YSZ (yttria stabilized zirconia), ScSZ (scandia stabilized zirconia), CaSZ (calcia stabilized zirconia), etc. It is formed of solid oxide of. By performing heat treatment at a temperature higher than the phase transition temperature, the crystal system of partially stabilized Zr undergoes a phase transition from a tetragonal crystal (tetra) having low oxygen ion conductivity to a cubic crystal (cubic) having high oxygen ion conductivity, When the heat treatment at a temperature lower than the transition temperature is performed for a predetermined time or longer, the crystal system of partially stabilized Zr undergoes a phase transition from a cubic crystal having high oxygen ion conductivity to a tetragonal crystal having low oxygen ion conductivity. For example, according to "Masatomo Yashima", 2 people outside, Solid State lonics, (Netherlands), Elsevier BV (1996), volume86-88, p. 1131, the 8YSZ solid electrolyte layer was used. The phase transition temperature of the partially stabilized Zr contained is 1200 (° C.). The air electrode 114 is a substantially rectangular flat plate-shaped member, and is formed of, for example, a perovskite type oxide (eg, LSCF (lanthanum strontium cobalt iron oxide), LSM (lanthanum strontium manganese oxide), LNF (lanthanum nickel iron)). Has been done. The fuel electrode 116 is a rectangular flat plate-shaped member, and is formed of, for example, Ni (nickel), a cermet made of Ni and ceramic particles, a Ni-based alloy, or the like. As described above, the unit cell 110 (power generation unit 102) of the present embodiment is a solid oxide fuel cell (SOFC) that uses a solid oxide as an electrolyte.

The intermediate layer 300 is a substantially rectangular plate-shaped member, and is made of, for example, a solid oxide such as GDC (gadolinium-doped ceria). The intermediate layer 300 includes a metal element (for example, Sr or La, hereinafter also referred to as “diffusion element”) contained in the air electrode 114 and an electrolyte under a high temperature condition such as during operation of the fuel cell stack 100. The layer 112 functions as a reaction preventing layer that suppresses the formation of the high resistance layer (eg, SrZrO ₃ ) by reacting with the transition element (eg, Zr) contained in the layer 112. Since the intermediate layer 300 has ion conductivity, it also has a function of moving oxide ions generated by the ionization reaction of oxygen molecules contained in the oxidant gas OG at the air electrode 114 to the electrolyte layer 112.

The separator 120 is a frame-shaped member in which a substantially rectangular hole 121 penetrating in the vertical direction is formed near the center, and is formed of, for example, metal. The peripheral portion of the hole 121 in the separator 120 faces the peripheral portion of the surface of the electrolyte layer 112 on the air electrode 114 side. The separator 120 is joined to the electrolyte layer 112 (single cell 110) by a joining portion 124 formed of a brazing material (for example, Ag brazing material) arranged in the facing portion. The separator 120 partitions the air chamber 166 facing the air electrode 114 and the fuel chamber 176 facing the fuel electrode 116, and gas leakage from one electrode side to the other electrode side in the peripheral portion of the unit cell 110 is prevented. Suppressed. The single cell 110 to which the separator 120 is joined is also referred to as a single cell with a separator.

The air electrode side frame 130 is a frame-shaped member in which a substantially rectangular hole 131 penetrating in the vertical direction is formed near the center, and is formed of an insulator such as mica. The hole 131 of the air electrode side frame 130 constitutes an air chamber 166 facing the air electrode 114. The air electrode side frame 130 is in contact with the peripheral edge portion of the surface of the separator 120 opposite to the side facing the electrolyte layer 112 and the peripheral edge portion of the surface of the interconnector 150 facing the air electrode 114. .. Further, the air electrode side frame 130 electrically insulates between the pair of interconnectors 150 included in the power generation unit 102. Further, in the air electrode side frame 130, an oxidant gas supply communication hole 132 that communicates the oxidant gas introduction manifold 161 and the air chamber 166, and an oxidant gas that communicates the air chamber 166 and the oxidant gas discharge manifold 162. A discharge communication hole 133 is formed.

The fuel electrode side frame 140 is a frame-shaped member having a substantially rectangular hole 141 penetrating in the vertical direction near the center, and is made of, for example, metal. The hole 141 of the fuel electrode side frame 140 constitutes a fuel chamber 176 facing the fuel electrode 116. The fuel electrode side frame 140 is in contact with the peripheral edge portion of the surface of the separator 120 facing the electrolyte layer 112 and the peripheral edge portion of the surface of the interconnector 150 facing the fuel electrode 116. Further, in the fuel electrode side frame 140, a fuel gas supply communication hole 142 that communicates the fuel gas introduction manifold 171 and the fuel chamber 176, and a fuel gas discharge communication hole 143 that communicates the fuel chamber 176 and the fuel gas discharge manifold 172. And are formed.

The fuel electrode side current collector 144 is arranged in the fuel chamber 176. The fuel electrode side current collector 144 includes an interconnector facing portion 146, an electrode facing portion 145, and a connecting portion 147 connecting the electrode facing portion 145 and the interconnector facing portion 146, and, for example, nickel or nickel alloy. It is made of stainless steel or the like. The electrode facing portion 145 is in contact with the surface of the fuel electrode 116 on the side opposite to the side facing the electrolyte layer 112, and the interconnector facing portion 146 is on the surface of the interconnector 150 facing the fuel electrode 116. Are in contact. However, as described above, since the lowermost power generation unit 102 in the fuel cell stack 100 does not include the lower interconnector 150, the interconnector facing portion 146 of the power generation unit 102 has a lower end plate. It is in contact with 106. Since the fuel electrode side current collector 144 has such a configuration, it electrically connects the fuel electrode 116 and the interconnector 150 (or the end plate 106). A spacer 149 made of mica, for example, is arranged between the electrode facing portion 145 and the interconnector facing portion 146. Therefore, the fuel electrode side current collector 144 follows the deformation of the power generation unit 102 due to the temperature cycle or the reaction gas pressure fluctuation, and the fuel electrode 116 and the interconnector 150 (or the end plate 106) via the fuel electrode side current collector 144. A good electrical connection with is maintained.

The air electrode side current collector 134 is arranged in the air chamber 166. The air electrode side current collector 134 is composed of a plurality of substantially square pole-shaped current collector elements 135, and is formed of, for example, ferritic stainless steel. The air electrode side current collector 134 is in contact with the surface of the air electrode 114 opposite to the side facing the electrolyte layer 112 and the surface of the interconnector 150 facing the air electrode 114. However, as described above, since the uppermost power generation unit 102 in the fuel cell stack 100 does not include the upper interconnector 150, the air electrode side current collector 134 in the power generation unit 102 is the upper end plate. It is in contact with 104. Since the air electrode side current collector 134 has such a configuration, it electrically connects the air electrode 114 and the interconnector 150 (or the end plate 104). The air electrode side current collector 134 and the interconnector 150 may be formed as an integral member.

A-2. Operation of the fuel cell stack 100:
As shown in FIGS. 2 and 4, the oxidant gas OG is supplied through a gas pipe (not shown) connected to a branch portion 29 of the gas passage member 27 provided at the position of the oxidant gas introduction manifold 161. Then, the oxidant gas OG is supplied to the oxidant gas introduction manifold 161 through the branch portion 29 of the gas passage member 27 and the hole of the main body portion 28, and the oxidant gas introduction manifold 161 oxidizes each power generation unit 102. It is supplied to the air chamber 166 through the agent gas supply communication hole 132. Further, as shown in FIGS. 3 and 5, the fuel gas FG is supplied through a gas pipe (not shown) connected to a branch portion 29 of the gas passage member 27 provided at the position of the fuel gas introduction manifold 171. Then, the fuel gas FG is supplied to the fuel gas introduction manifold 171 through 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 is made from the fuel gas introduction manifold 171. The fuel is supplied to the fuel chamber 176 through the hole 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, power generation is performed in the single cell 110 by an electrochemical reaction of the oxidant gas OG and the fuel gas FG. Be seen. This power generation reaction is an exothermic reaction. In each power generation unit 102, the air electrode 114 of the unit cell 110 is electrically connected to one interconnector 150 via the air electrode side current collector 134, and the fuel electrode 116 via the fuel electrode side current collector 144. It is electrically connected to the other interconnector 150. Further, the plurality of power generation units 102 included in the fuel cell stack 100 are electrically connected in series. Therefore, the electric energy generated in each power generation unit 102 is extracted from the end plates 104 and 106 that function as the output terminals of the 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 ( It may be heated by (not shown).

The oxidant off-gas OOG exhausted from the air chamber 166 of each power generation unit 102 is exhausted to the oxidant gas exhaust manifold 162 via the oxidant gas exhaust communication hole 133 as shown in FIGS. The fuel cell stack 100 is passed through the holes of the main body portion 28 and the branch portion 29 of the gas passage member 27 provided at the position of the agent gas discharge manifold 162, and through the gas pipe (not shown) connected to the branch portion 29. Is discharged to the outside. Further, the fuel off-gas FOG discharged from the fuel chamber 176 of each power generation unit 102 is discharged to the fuel gas discharge manifold 172 through the fuel gas discharge communication hole 143 as shown in FIGS. To the outside of the fuel cell stack 100 via the gas pipe (not shown) connected to the branch portion 29 through the holes of the main body portion 28 and the branch portion 29 of the gas passage member 27 provided at the position of the exhaust manifold 172. Emitted.

A-3. Manufacturing method of the fuel cell stack 100:
FIG. 6 is a flowchart showing an example of a method for manufacturing the fuel cell stack 100 according to this embodiment. Further, FIG. 7 is an explanatory diagram showing an outline of a method of manufacturing the single cell 110 in the method of manufacturing the fuel cell stack 100 according to the present embodiment.

As shown in FIG. 6, first, heat treatment A is performed at a temperature equal to or higher than the phase transition temperature of the partially stabilized Zr included in the electrolyte layer 112 (hereinafter, may be simply referred to as “phase transition temperature T(0)”). The first layered body of the electrolyte layer 112 and the fuel electrode 116 is formed by firing the electrolyte layer precursor and the fuel electrode precursor (S110). For example, a butyral resin, a plasticizer, dioctyl phthalate (DOP), a dispersant, and a mixed solvent of toluene and ethanol are added to YSZ powder and mixed in a ball mill to prepare a slurry. The obtained slurry is thinned by a doctor blade method to prepare an electrolyte layer green sheet 112X (electrolyte layer precursor) having a thickness of about 10 (μm), for example. Further, the NiO powder is weighed so as to be 55 parts by mass in terms of Ni weight, and mixed with 45 parts by mass of the YSZ powder to obtain a mixed powder. A butyral resin, DOP which is a plasticizer, a dispersant, and a mixed solvent of toluene and ethanol are added to this mixed powder and mixed by a ball mill to prepare a slurry. The obtained slurry is thinned by a doctor blade method to prepare, for example, a fuel electrode green sheet 116X (fuel electrode precursor) having a thickness of 270 (μm). Then, as shown in <State 1> of FIG. 7, the electrolyte layer green sheet 112X and the fuel electrode green sheet 116X are attached and dried. After that, as the heat treatment A, the electrolyte layer green sheet 112X and the fuel electrode green sheet 116X that are attached to each other are fired at a temperature T(1) (for example, 1200 (° C.) to 1400 (° C.)) to obtain an electrolyte. A first laminated body 410 of the layer 112 and the fuel electrode 116 is obtained. Since the temperature T(1) is equal to or higher than the phase transition temperature T(0), the heat treatment A changes the crystal system of partially stabilized Zr from a tetragonal crystal with low oxygen ion conductivity to a cubic crystal with high oxygen ion conductivity. Phase transition. The temperature T(1) in the heat treatment A means a temperature in a substantially constant temperature stage, not in the temperature raising stage and the temperature lowering stage. The same applies to the heat treatments B to D.

Next, the intermediate layer precursor is fired by performing a heat treatment B at a temperature equal to or higher than the phase transition temperature T(0), thereby forming the intermediate layer 300 on the first stacked body 410 and forming the electrolyte layer 112. A second stack 420 of the fuel electrode 116 and the intermediate layer 300 is formed (S120). More specifically, for example, a solvent composed of an acrylic binder and isopropyl alcohol is added to GDC powder and mixed to prepare a slurry 300X for forming an intermediate layer (intermediate layer precursor). Then, as shown in <State 2> of FIG. 7, the prepared intermediate layer forming slurry 300X is applied to the surface of the first laminated body on the electrolyte layer 112 side by a screen printing method. Then, the laminated body after coating is fired at a temperature T(2) (for example, 1200 (° C.) to 1400 (° C.)), so that the electrolyte layer 112 and the fuel electrode 112 can be formed as shown in <state 3> of FIG. 7. A second stacked body 420 of 116 and the intermediate layer 300 is obtained. Thus, the denseness of the intermediate layer 300 can be improved by firing the applied laminated body at a high temperature of the phase transition temperature T(0) or higher. Further, since the temperature T(2) is equal to or higher than the phase transition temperature T(0), even after the heat treatment B, the crystal system of partially stabilized Zr remains cubic and does not undergo phase transition. The temperature T(2) may be the same as the temperature T(1) described above, or may be a different temperature as long as the temperature is equal to or higher than the phase transition temperature T(0). The heat treatment A and the heat treatment B correspond to the first heat treatment in the claims, and the second laminate 420 corresponds to the laminate in the claims.

Next, the second laminated body 420 is subjected to the heat treatment C at a temperature lower than the phase transition temperature T(0) for 10 hours or more (S130). More specifically, the heat treatment C at the temperature T(3) (for example, 1000 (° C.) to 1100 (° C.)) is continuously performed on the second stacked body 420 for 10 (hours) or more. Thereby, the crystal system of at least a part (for example, about 10 (%) or more) of the partially stabilized Zr contained in the electrolyte layer 112 is changed from a cubic crystal having high oxygen ion conductivity to a tetragonal crystal having low oxygen ion conductivity. Can be transferred.

Next, the air electrode precursor is fired by performing a heat treatment D at a temperature lower than the phase transition temperature T(0), whereby the air electrode 114 is formed in the second stacked body 420 to form the single cell 110. It is manufactured (S140). More specifically, for example, LSCF powder, alumina powder, polyvinyl alcohol as an organic binder, and butyl carbitol as an organic solvent are mixed and the viscosity is adjusted to prepare the air electrode paste 114X. Then, as shown in <state 4> of FIG. 7, the adjusted air electrode paste 114X is applied to the surface of the second stacked body 420 on the intermediate layer 300 side by, for example, screen printing, and dried. As the method for applying the second laminated body 420, another method such as spray application can be adopted. After that, as the heat treatment D, the applied air electrode paste 114X is fired at a temperature T(4) lower than the phase transition temperature T(0) (for example, 950 (° C.) to 980 (° C.)), and thus FIG. As shown in <State 5>, the air electrode 114 is formed on the electrolyte layer 112 side in the second stacked body 420, and the single cell 110 is manufactured. The heat treatment D corresponds to the third heat treatment in the claims.

A plurality of unit cells 110 are manufactured by the manufacturing method described above, and an assembly step of assembling the manufactured unit cells 110 and other members is performed (S150). Through the above steps, the fuel cell stack 100 having the above configuration is manufactured.

A-4. Performance evaluation of each sample:
Each performance evaluation performed using a plurality of samples 1 to 8 manufactured by a plurality of manufacturing methods having different manufacturing conditions and manufacturing steps will be described. In the performance evaluation of each sample, the fuel cell stack 100 having the above-described configuration was assembled for each of the plurality of samples 1 to 8, and the durability deterioration rate (power generation deterioration rate) was measured. FIG. 8 is an explanatory diagram showing the results of performance evaluation for each sample.

(About sample)
Samples 1 to 6 were manufactured by the manufacturing method shown in FIG. 6, and Samples 7 and 8 were manufactured by a manufacturing method different from the manufacturing method shown in FIG. It is a thing.
(Sample 1)
In the manufacturing method of Sample 1, the temperature T(1) of the heat treatment A and the temperature T(2) of the heat treatment B are 1205 (° C.), the temperature T(3) of the heat treatment C is 1100 (° C.), and the heat treatment C is The execution time of is 10 (hours).
(Sample 2)
In the manufacturing method of sample 2, the temperature T(1) of heat treatment A, the temperature T(2) of heat treatment B, and the temperature T(3) of heat treatment C are the same as those of sample 1, but the execution time of heat treatment C is 50. (Time), which is longer than Sample 1.
(Sample 3)
In the manufacturing method of sample 3, the temperature T(1) of heat treatment A, the temperature T(2) of heat treatment B, and the temperature T(3) of heat treatment C are the same as those of sample 1, but the execution time of heat treatment C is 100. (Time), which is longer than Samples 1 and 2.

(Sample 4)
In the manufacturing method of Sample 4, the temperature T(1) of the heat treatment A and the temperature T(2) of the heat treatment B are the same as those of the sample 1, but the temperature T(3) of the heat treatment C is 1000 (° C.), It is lower than Samples 1 to 3 and the execution time of heat treatment C is 25 (hours), which is longer than that of Sample 1.
(Sample 5)
In the manufacturing method of sample 5, the temperature T(1) of heat treatment A and the temperature T(2) of heat treatment B are the same as those of sample 1, and the temperature T(3) of heat treatment C is the same as that of sample 4. However, the execution time of the heat treatment C is 125 (hours), which is longer than that of the samples 1 to 4.
(Sample 6)
In the manufacturing method of sample 6, the temperature T(1) of heat treatment A and the temperature T(2) of heat treatment B are the same as those of sample 1, and the temperature T(3) of heat treatment C is the same as that of sample 4. However, the execution time of the heat treatment C is 240 (hours), which is longer than that of the samples 1 to 5.

(Sample 7)
In the manufacturing method of the sample 7, the temperature T(1) of the heat treatment A and the temperature T(2) of the heat treatment B are 1100 (° C.), which is lower than those of the samples 1 to 5, and after the heat treatments A and B are performed, Heat treatment D is performed without performing heat treatment C.
(Sample 8)
In the manufacturing method of the sample 8, the temperature T(1) of the heat treatment A and the temperature T(2) of the heat treatment B are the same as those of the sample 1, but like the sample 7, after the heat treatments A and B are performed, the heat treatment C is performed. The heat treatment D is performed without executing the heat treatment.

(About the method of performance evaluation)
First, with respect to the fuel cell stack 100 manufactured by the manufacturing method of each of Samples 1 to 8, the denseness of the intermediate layer 300 was evaluated based on the porosity of the intermediate layer 300 (GDC). The porosity of the intermediate layer 300 is specified as follows. The cross section of the power generation unit 102 orthogonal to the flow direction of the oxidant gas is set at three positions arranged along the flow direction of the oxidant gas (in the present embodiment, the X-axis direction as shown in FIG. 2 ). SEM images (500 times) showing the intermediate layer 300 are obtained at the three positions. That is, nine SEM images are obtained. In each of the obtained SEM images, a plurality of lines orthogonal to the arrangement direction of the power generation units 102 (Z-axis direction in this embodiment) are drawn at predetermined intervals (for example, 1 to 5 μm intervals). The length of the part corresponding to the pores on each straight line is measured, and the ratio of the total length of the part corresponding to the pores to the total length of the straight line is defined as the porosity on the line. The average value of the porosities of a plurality of straight lines drawn on the intermediate layer 300 is the porosity of the intermediate layer 300 in the SEM image. The final porosity of the intermediate layer 300 is obtained by taking the average value of the porosities obtained in the nine SEM images.

Further, with respect to the fuel cell stack 100 manufactured by the manufacturing method of each of Samples 1 to 8, the phase transition peak intensity ratio of the partially stabilized Zr in the electrolyte layer 112 was evaluated. The phase transition peak intensity ratio is, for example, "Taro Shimonosono (5), Solid State lonics (Netherlands), Elsevier BV (2012), volume 225, p. 69-72". Were measured according to Raman spectroscopy as shown in. The phase transition peak intensity ratio is such that the crystal system of partially stabilized Zr contained in the electrolyte layer 112 corresponds to the cubic (600 to 650 cm ⁻¹ ) crystal structure of partially stabilized Zr, and the crystal system of partially stabilized Zr is cubic to tetragonal. Is the ratio of the intensity peak (250 to 300 cm ⁻¹ ) when the phase transitions to. Therefore, the larger the phase transition peak intensity ratio, the greater the proportion of partially stabilized Zr in which the crystal system undergoes a phase transition from cubic to tetragonal.

Further, the fuel cell stack 100 manufactured by the manufacturing method of each of Samples 1 to 8 was generated at 700 (° C.) for 1000 (hours) and then generated at a current density of 0.55 (A/cm ² ). (Post-test voltage) was measured, and the ratio of the difference between the initial voltage and the post-test voltage with respect to the initial voltage was calculated as the power generation deterioration rate (%) by the following formula 1.
<Formula 1>
Power generation deterioration rate (%)=(initial voltage-voltage after test)/initial voltage)×100
The initial voltage means a current density of 0.55 (A/A) at 700 (° C.) with respect to the fuel cell stack 100 in which rated power generation is performed within 1000 hours after being shipped in a power-generating state. It is a voltage value when the power generation operation is performed in cm ² ).
In addition, the post-test voltage refers to the fuel cell stack 100 that has been subjected to rated power generation for 1000 hours from the time of measuring the initial voltage, and power generation at 700 (° C.) with a current density of 0.55 (A/cm 2 ). It is the voltage value after the operation.

(About performance evaluation results)
In each of Samples 1 to 3, the GDC porosity was 20 (%) or less, and the intermediate layer 300 had high denseness. It is considered that this is because the temperatures T(1) to T(3) of the heat treatments A to C are relatively high in the manufacturing method of Samples 1 to 3. In addition, in Samples 1 to 3, as the execution time of the heat treatment C is longer, the phase transition peak intensity ratio becomes closer to 1 and the power generation deterioration rate tends to be low. That is, under the same temperature condition, the longer the heat treatment C is performed, the more the crystal system of partially stabilized Zr undergoes the phase transition from the cubic system to the tetragonal system, so that the power generation deterioration rate can be reduced.

In Samples 4 to 6, the GDC porosity is 22 to 23 (%), and the denseness of the intermediate layer 300 is slightly lower than in Samples 1 to 3. It is considered that this is because the temperature T(3) of the heat treatment C is lower than that of the samples 1 to 3. Further, in sample 4, although the execution time of heat treatment C is longer than in sample 1, the phase transition peak intensity ratio and the power generation deterioration rate are the same as in sample 1. This is because when the temperature T(3) of the heat treatment C is relatively low, the execution time of the heat treatment C is required to obtain the same performance evaluation result as when the temperature T(3) of the heat treatment C is relatively high. Means that is relatively long. Therefore, the temperature T(3) of the heat treatment C is preferably lower than the phase transition temperature and 1000 (° C.) or higher, and further lower than the phase transition temperature and 1100 (° C.) or higher. More preferable. The same applies to the relationship between sample 5 and sample 2 and the relationship between sample 6 and sample 3.

On the other hand, in Sample 7, the GDC porosity is 45 (%), and the denseness of the intermediate layer 300 is extremely low as compared with Samples 1 to 6. It is considered that this is because the temperatures T(1) and T(2) of the heat treatments A and B are lower than those of the samples 1 to 6. As described above, in Sample 7, the denseness of the intermediate layer 300 is extremely low, and therefore the intermediate layer 300 cannot sufficiently exhibit the function as the reaction preventing layer. Therefore, it is difficult to specify the power generation deterioration rate by forming the high resistance layer. Further, in Sample 7, the phase transition peak intensity ratio is 0.905, which is lower than in Samples 1 to 6. In the manufacturing method of Sample 7, heat treatments C and C were not performed, but heat treatments A and B were performed at a temperature at which the crystal system of partially stabilized Zr was lower than the phase transition temperature from tetragonal to cubic. The proportion of partially stabilized Zr in the crystal is relatively low. That is, it is not possible to sufficiently obtain partially stabilized Zr having a tetragonal crystal system and to reduce the porosity of the intermediate layer 300 sufficiently by simply performing the firing at a temperature lower than the phase transition temperature. I understand. Therefore, in Sample 7, it is considered that the resistance value became too large and the power generation deterioration rate could not be measured.

Further, in the sample 8, the GDC porosity is 26 (%), and the intermediate layer 300 has higher density than the sample 7. It is considered that this is because the temperatures T(1) and T(2) of the heat treatments A and B are higher than those of the sample 7. However, in the sample 8, the phase transition peak intensity ratio is 0.900, which is lower than that of the sample 7. This is because the temperature T(1) T(2) of the heat treatments A and B is higher than that of the sample 7, and the relative proportion of partially stabilized Zr in which the crystal system undergoes a phase transition from tetragonal to cubic due to the heat treatments A and B is relatively high. It is considered that this is because the ratio of partially stabilized Zr in which the crystal system remains cubic is large because the heat treatment C is not performed.

A-5. Effects of this embodiment:
According to the manufacturing method of the present embodiment, the electrolyte layer precursor, the fuel electrode precursor, and the intermediate layer precursor are subjected to the heat treatment B at a temperature equal to or higher than the phase transition temperature of the partially stabilized Zr, so that the second stacking is performed. The body 420 is formed and the intermediate layer 300 of the second stack 420 can be densified. On the other hand, the heat treatment B causes the partially stabilized Zr crystal system to undergo a phase transition from a tetragonal crystal with low oxygen ion conductivity to a cubic crystal with high oxygen ion conductivity. However, after that, the second stacked body 420 is subjected to the heat treatment C at a temperature lower than the phase transition temperature for 10 hours or more, so that the crystal system of partially stabilized Zr undergoes a phase transition from a cubic system to a tetragonal system. The second stacked body 420 and the air electrode precursor after the heat treatment C are subjected to the heat treatment D at a temperature lower than the phase transition temperature, so that the crystal system of the partially stabilized Zr contains a tetragonal crystal sufficiently. The cell 110 is formed. Moreover, by performing the heat treatment C before forming the air electrode 114, it is possible to suppress a decrease in gas diffusibility of the air electrode 114 due to the progress of sintering of the air electrode precursor. Accordingly, it is possible to manufacture the single cell 110 in which the fluctuation (decrease) in the power generation performance during operation is reduced while suppressing the decrease in the gas diffusibility of the air electrode 114. Further, since the heat treatment C is performed before the formation of the air electrode 114, the transition metal element (Sr or the like) contained in the air electrode 114 is closer to the electrolyte layer 112 than in the case where the heat treatment C is performed simultaneously with the formation of the air electrode 114. Can be suppressed.

Further, the execution time of the heat treatment D is preferably shorter than the execution time of the heat treatment C. As a result, it is possible to more reliably suppress the decrease in gas diffusibility of the air electrode 114.

B. Modification:
The technique 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 also possible.

In the above embodiment, the single cell 110 including the electrolyte layer 112 containing partially stabilized Zr is exemplified as the electrochemical reaction cell, but the electrochemical reaction cell is not limited to this, and the fuel electrode containing partially stabilized Zr is used. It may be a single cell including. Specifically, the fuel electrode may be formed of a solid oxide such as YSZ, ScSZ, CaSZ.

In the manufacturing method of the fuel cell stack 100 of the above-described embodiment, the heat treatment A and the heat treatment B are performed twice as the first heat treatment. However, the first heat treatment is not limited to this, and the partially stabilized Zr may be used. The heat treatment at a temperature equal to or higher than the phase transition temperature may be performed only once or three times or more. In short, the first heat treatment may be one in which the heat treatment at a temperature equal to or higher than the phase transition temperature of partially stabilized Zr is performed once or plural times. For example, in the above embodiment, the electrolyte layer green sheet 112X, the fuel electrode green sheet 116X, and the intermediate layer forming slurry 300X may be simultaneously fired.

In the above-described embodiment, the intermediate layer 300 composed of one layer is exemplified as the intermediate layer, but the intermediate layer is not limited to this, and the intermediate layer is composed of a plurality of layers arranged in the vertical direction (Z direction). Layers are also good. Further, the intermediate layer is not limited to one that functions as a reaction preventing layer, and may be one that does not function as a reaction preventing layer. Further, the intermediate layer may include another material in addition to the intermediate layer material having ion conductivity.

Further, in the above embodiment, the number of power generation units 102 included in the fuel cell stack 100 is merely an example, and the number of power generation units 102 is appropriately determined according to the output voltage or the like required for the fuel cell stack 100.

Further, in the above embodiment, the nuts 24 are fitted on both sides of the bolt 22, but the bolt 22 has a head and the nut 24 is fitted only on the opposite side of the head of the bolt 22. Good. Further, although the bolt 22 is used as the fastening member in the above embodiment, the fuel cell stack 100 may be fastened by a fastening member other than the bolt 22.

In the above embodiment, the end plates 104 and 106 function as output terminals, but instead of the end plates 104 and 106, separate members (for example, the end plate 104) connected to the end plates 104 and 106, respectively. , 106 and the power generation unit 102 may function as an output terminal.

In the above embodiment, the space between the outer peripheral surface of the shaft portion of each bolt 22 and the inner peripheral surface of each communication hole 108 is used as each manifold, but instead of this, the shaft of each bolt 22 is used. It is also possible to form an axial hole in the portion and use the hole as each manifold. Further, each manifold may be provided separately from the communication hole 108 into which each bolt 22 is inserted.

Further, in the above embodiment, when the two power generation units 102 are arranged adjacent to each other, one interconnector 150 is shared by the two adjacent power generation units 102, but in such a case as well. The two power generation units 102 may include respective interconnectors 150. Further, in the above-described embodiment, the upper interconnector 150 of the power generation unit 102 located at the top and the lower interconnector 150 of the power generation unit 102 located at the bottom in the fuel cell stack 100 are omitted. These interconnectors 150 may be provided without omission.

Further, in the above-described embodiment, the fuel electrode side current collector 144 may have the same configuration as the air electrode side current collector 134, and the fuel electrode side current collector 144 and the interconnector 150 adjacent to the fuel electrode side current collector 144 are integrated members. May be Further, the fuel electrode side frame 140 may be an insulator instead of the air electrode side frame 130. The air electrode side frame 130 and the fuel electrode side frame 140 may have a multi-layered structure.

In addition, the material forming each member in the above embodiment is merely an example, and each member may be formed of other materials.

In the above embodiment, the city gas is reformed to obtain the hydrogen-rich fuel gas FG, but the fuel gas FG may be obtained from other raw materials such as LP gas, kerosene, methanol, and gasoline. Pure hydrogen may be used as the fuel gas FG.

Further, in the above-described embodiment, the SOFC that generates electric power by utilizing the electrochemical reaction between hydrogen contained in the fuel gas and oxygen contained in the oxidant gas is targeted, but the present invention is directed to the electrolysis reaction of water. It is similarly applicable to an electrolytic cell unit, which is the minimum unit of a solid oxide type electrolytic cell (SOEC) that produces hydrogen by utilizing hydrogen, or an electrolytic cell stack including a plurality of electrolytic cell units. The configuration of the electrolysis cell stack is publicly known as described in, for example, JP-A-2016-81813 and will not be described in detail here. However, the configuration of the fuel cell stack 100 in the above-described embodiment is generally the same. It is a composition. That is, the fuel cell stack 100 in the above-described embodiment may be read as an electrolysis cell stack, and the power generation unit 102 may be read as an electrolysis cell unit. However, during the operation of the electrolysis cell stack, a voltage is applied between both electrodes so that the air electrode 114 becomes positive (anode) and the fuel electrode 116 becomes negative (cathode), and at the same time through the communication hole 108. Steam as a raw material gas is supplied. As a result, an electrolysis reaction of water occurs in each electrolytic cell unit, hydrogen gas is generated in the fuel chamber 176, and hydrogen is taken out of the electrolytic cell stack through the communication hole 108. Also in the electrolytic cell unit and the electrolytic cell stack having such a configuration, by the manufacturing method similar to the above embodiment, while suppressing a decrease in the gas diffusibility of the air electrode, the fluctuation of the electrochemical reaction performance during operation is reduced. It is possible to manufacture electrolytic cell units and the like.

22: Bolt 24: Nut 26: Insulation sheet 27: Gas passage member 28: Main body part 29: Branch part 45: Powder 100: Fuel cell stack 102: Power generation unit 104, 106: End plate 108: Communication hole 110: Single cell 112 : Electrolyte layer 112X: Electrolyte layer green sheet 114: Air electrode 114X: Air electrode paste 116: Fuel electrode 116X: Fuel electrode green sheet 120: Separator 121: Hole 124: Joined portion 130: Air electrode side frame 131: Hole 132: Oxidant gas supply communication hole 133: Oxidant gas discharge communication hole 134: Air electrode side current collector 135: Current collector element 140: Fuel electrode side frame 141: Hole 142: Fuel gas supply communication hole 143: Fuel gas Discharge communication hole 144: Fuel electrode side current collector 145: Electrode facing portion 146: Interconnector facing portion 147: Connecting portion 149: Spacer 150: Interconnector 161: Oxidizing gas introduction manifold 162: Oxidizing gas discharge manifold 166: Air Chamber 171: Fuel gas introduction manifold 172: Fuel gas discharge manifold 176: Fuel chamber 270: Thickness 300: Intermediate layer 300X: Slurry for forming intermediate layer 410: Laminated body 420: Laminated body FG: Fuel gas FOG: Fuel off gas OG: Oxidizing agent gas OOG: Oxidizing agent off gas

Claims (2)

An electrolyte layer containing a solid oxide,
An air electrode and a fuel electrode facing each other in the first direction with the electrolyte layer interposed therebetween,
An intermediate layer arranged between the electrolyte layer and the air electrode, wherein at least one of the electrolyte layer and the fuel electrode contains partially stabilized Zr, in the method for producing an electrochemical reaction cell,
A step of preparing an electrolyte layer precursor, a fuel electrode precursor and an intermediate layer precursor,
By subjecting the electrolyte layer precursor, the fuel electrode precursor, and the intermediate layer precursor to a first heat treatment at a temperature equal to or higher than the phase transition temperature of the partially stabilized Zr, the electrolyte layer and the fuel electrode are separated. Forming a laminate with the intermediate layer,
Performing a second heat treatment at a temperature lower than the phase transition temperature on the laminate for 10 hours or more;
The second even after heat treatment, the laminate cathode precursor is formed on the surface of the intermediate layer side, by performing the third heat treatment lower than the phase transition temperature, the electrochemical And a step of forming a reaction cell ,
The step of forming the laminate includes
After forming the first laminated body of the electrolyte layer and the fuel electrode by performing the first heat treatment in a state where the electrolyte layer precursor and the fuel electrode precursor are laminated, the first laminated body A step of performing the first heat treatment in a state where the intermediate layer precursor is laminated on the surface of the body on the side of the electrolyte layer;
Wherein in a state where the electrolyte layer precursor and the fuel electrode precursor was laminated with the intermediate layer precursor, and wherein the step, either one der Rukoto of performing one of the first heat treatment, Method for manufacturing electrochemical reaction cell. The method for producing an electrochemical reaction cell according to claim 1,
The method for manufacturing an electrochemical reaction cell, wherein the time for performing the third heat treatment is shorter than the time for performing the second heat treatment.

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