JP2016095924A - Solid oxide fuel battery cell, and manufacturing method and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a solid oxide fuel battery cell, by which small power-generation elements can be formed on a single support body even if the porous support body is low in dimensional accuracy.SOLUTION: A method for manufacturing a solid oxide fuel battery cell (16) in which power-generation elements (16a) are formed on a porous support body (97), and the power-generation elements are connected by interconnectors (102) comprises: a support body formation step; a fuel electrode layer formation step for forming fuel electrode layers (98) of the power-generation elements on the porous support body concurrently by a two-dimensional film formation method; an interconnector formation step for forming the interconnectors by accumulation of slurry dots; an electrolyte layer formation step; an air electrode layer formation step for forming air electrode layers (101) of the power-generation elements on the electrolyte layers (100) by accumulation of slurry dots; and a sintering step for heating the porous support body with the respective functional layers formed thereon to sinter the respective layers.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a solid oxide fuel cell, and in particular, a solid oxide fuel cell in which a plurality of power generation elements are formed on a porous support and these power generation elements are connected by an interconnector, and the production thereof. The present invention relates to a method and a manufacturing apparatus.

  A solid oxide fuel cell (hereinafter also referred to as “SOFC”) uses an oxide ion conductive solid electrolyte as an electrolyte, has electrodes attached to both sides thereof, and supplies fuel gas to one side. The fuel cell operates at a relatively high temperature by supplying an oxidant gas (air, oxygen, etc.) to the other side.

  Japanese Patent Laying-Open No. 2013-175305 (Patent Document 1) describes a method for manufacturing a solid oxide fuel cell. In the solid oxide fuel cell described here, a plurality of power generation elements each including a fuel electrode, a solid electrolyte membrane, and an air electrode are formed on a base tube, and these power generation elements are electrically connected by an interconnector. Is connected to. In this fuel cell manufacturing method, a fuel electrode is formed on a substrate tube by a screen printing method, and then a solid electrolyte membrane and an interconnector are sequentially formed by a screen printing method. The base tube in which each layer is thus formed is co-sintered in the atmosphere, and then an air electrode is formed on the sintered solid electrolyte membrane using a dispenser. That is, the slurry in which the powder of the material forming the air electrode is suspended is discharged onto the solid electrolyte membrane and the interconnector, and the air electrode slurry film is formed at the position where the air electrode is to be formed. Finally, the base tube on which the air electrode is formed is sintered in the atmosphere.

JP 2013-175305 A

  However, the fuel cell in which a plurality of power generation elements are formed on a single support has a problem that it is difficult to integrate a large number of power generation elements. That is, a support such as a base tube is generally a porous body obtained by firing a molded body formed by extrusion molding or the like, and thus it is difficult to form the support with high dimensional accuracy. When forming a plurality of power generation elements on a support with such low dimensional accuracy, it is necessary to allow for a large margin in the distance between the power generation elements to be formed in consideration of the dimensional error and shape error of the support. High integration becomes difficult. In order to ensure the dimensional accuracy of the support, if the fired support is machined, there is a problem that the manufacturing cost is remarkably increased.

  Further, when a plurality of power generation elements are formed on a small fuel cell, each power generation element is downsized, so that a functional layer such as a fuel electrode layer, an electrolyte layer, and an air electrode layer of each power generation element, and An interconnector that electrically connects each power generating element is required to have high dimensional accuracy and positional accuracy. That is, since each power generating element is formed by sequentially laminating each functional layer on the support, the dimensional accuracy of each layer is increased, and the functional layer laminated on top is a functional layer laminated below Need to be accurately positioned. Furthermore, since the interconnector that electrically connects the power generation elements formed by stacking the functional layers in this way is a portion that does not contribute to power generation, it is preferable to form smaller than each power generation element. Dimensional accuracy and position accuracy are particularly required.

  Therefore, the present invention provides a solid oxide fuel cell capable of forming a plurality of small power generating elements on a single support even when the dimensional accuracy of the porous support is low, and a method for manufacturing the same, The object is to provide a manufacturing apparatus.

  In order to solve the above-mentioned problems, the present invention provides a method for producing a solid oxide fuel cell in which a plurality of power generation elements are formed on a porous support and these power generation elements are connected by an interconnector. Forming a porous support and a slurry for forming a fuel electrode layer on the formed porous support to simultaneously form the fuel electrode layers of a plurality of power generating elements on the surface. A fuel electrode layer forming step formed by a film, and slurry dots for forming an interconnector are formed in droplets and continuously ejected so as to be connected to the fuel electrode layer. An interconnector forming step of forming an interconnector by integrating dots, an electrolyte layer forming step of forming an electrolyte layer of a plurality of power generating elements on the fuel electrode layer, and an air on the electrolyte layer Forming an air electrode layer of a plurality of power generation elements by forming dots of the slurry by continuously spraying slurry for forming a layer into droplets, and collecting the dots; And a firing step of firing each layer by heating the porous support on which the fuel electrode layer, the electrolyte layer, and the air electrode layer are formed.

  In the present invention configured as described above, slurry is deposited in the fuel electrode layer forming step on the porous support formed in the support forming step, and the fuel electrode layers of a plurality of power generating elements are formed into a surface film. Are simultaneously formed. Next, in the interconnector forming step, the interconnector is formed so as to be connected to the fuel electrode layer by accumulation of the slurry dots. Furthermore, in the electrolyte layer forming step, an electrolyte layer of a plurality of power generating elements is formed on the fuel electrode layer. On the electrolyte layer, in the air electrode layer forming step, a plurality of power generating elements are accumulated by accumulation of slurry dots. An air electrode layer is formed. Finally, in the firing step, the porous support on which the fuel electrode layer, the electrolyte layer, and the air electrode layer are formed is fired.

  According to the present invention thus configured, the fuel electrode layer formed immediately above the porous support is formed by surface film formation, and the interconnector and air electrode layer formed thereon are formed as slurry dots. It is formed by accumulation. Thus, since the lowermost fuel electrode layer is formed by surface film formation, a fuel electrode layer with high smoothness can be formed, and adverse effects on the upper electrolyte layer and the like can be suppressed. That is, when the fuel electrode layer is formed by accumulation of dots, the smoothness of the surface of the fuel electrode layer is lowered, and therefore, when the fuel electrode layer is subjected to the reduction treatment, it is laminated on the fuel electrode layer. The present inventor has found a new technical problem that the functional layer is adversely affected. This is because when the fuel electrode layer is reduced, oxygen disappears from the layer and the volume is reduced. If the fuel electrode layer has low smoothness, a large shape change occurs on the surface of the layer, resulting in dense formation. That is, peeling or the like occurs between the electrolyte layer.

In addition, according to the present invention, since the interconnector is formed by accumulation of dots, even when the dimensional accuracy of the porous support is low, the interconnector can be easily formed with a small size, high dimensional accuracy, and positional accuracy. be able to. In addition, since the interconnector is small, even when it is formed by dot accumulation, it does not require enormous time for film formation and does not reduce manufacturing efficiency. Furthermore, according to the present invention, since the air electrode layer is also formed by dot accumulation, it can be easily formed with high dimensional accuracy and position accuracy. Further, since the reduction treatment is not performed on the air electrode layer, even if the surface is formed by accumulation of dots and the smoothness of the surface is low, there is no adverse effect due to the shape change.
As described above, according to the present invention, the lowermost fuel electrode layer, the interconnector formed thereon, and the air electrode layer are each formed by an appropriate film forming method. Even when the dimensional accuracy is low, a plurality of small power generating elements can be formed on a single support, and adverse effects associated with the reduction treatment can be avoided.

In the present invention, preferably, the porous support is formed of an insulating material, and the plurality of fuel electrode layers formed on the porous support are insulated from each other.
According to the present invention configured as described above, since the porous support is formed of an insulating material, the fuel electrode layers of the respective power generation elements are formed on the porous support separately from each other. Are insulated from each other. Here, when the fuel electrode layer is formed by accumulation of dots, if the viscosity of the slurry to be injected is low, the slurry penetrates into the porous support body, and a short circuit occurs between the fuel electrode layers formed apart from each other. There is a risk of doing. Further, when the viscosity of the slurry to be sprayed is increased, the penetration of the slurry can be avoided. However, since each dot to be formed becomes smaller, the time required for dot film formation becomes longer and the production efficiency is increased. Is significantly reduced. According to the present invention, since the fuel electrode layer is formed by surface film formation, the viscosity of the slurry for forming the fuel electrode layer is increased, and while preventing the slurry from penetrating into the porous support body, the efficiency is improved. Thus, a fuel electrode layer can be formed.

  In the present invention, preferably, the fuel electrode layer comprises a lower fuel electrode layer formed on the porous support and an upper fuel electrode layer formed on the lower fuel electrode layer. The viscosity of the slurry for forming is higher than the viscosity of the slurry for forming the upper fuel electrode layer.

  According to the present invention configured as described above, since the lower fuel electrode layer formed on the porous support is formed of a highly viscous slurry, it is possible to prevent the slurry from penetrating into the porous support. It is possible to reliably prevent a short circuit between the fuel electrode layers. Further, since the upper fuel electrode layer is formed from a slurry having low viscosity, the surface of the fuel electrode layer can be formed more smoothly, and the adverse effect on the electrolyte layer formed thereon can be extremely reduced. .

  In the present invention, preferably, the lower fuel electrode layer is made of a material having higher conductivity than the upper fuel electrode layer, and the upper fuel electrode layer is made of a material having higher catalytic activity than the lower fuel electrode layer.

  According to the present invention configured as described above, since the upper fuel electrode layer is formed of a material having high catalytic activity, a power generation reaction can be efficiently generated at the boundary with the electrolyte layer, and the lower fuel electrode can be generated. Since the layer is formed of a highly conductive material, the charge generated by the power generation reaction can be transported with low loss.

  In the present invention, preferably, the air electrode layer includes a lower air electrode layer formed on the electrolyte layer and an upper air electrode layer formed on the lower air electrode layer, forming a lower air electrode layer. The viscosity of the slurry for forming the upper air electrode layer is lower than the viscosity of the slurry for forming the upper air electrode layer.

  According to the present invention configured as described above, since the lower air electrode layer is formed by accumulation of dots of low viscosity slurry, the surface of the lower air electrode layer can be made relatively smooth, and oxygen ions Can be made uniform in each part. On the other hand, since the upper air electrode layer is formed by accumulation of highly viscous slurry dots, the upper air electrode layer can be formed thicker and the strength of the air electrode layer can be increased. Thereby, the air electrode layer with high strength of stable performance can be formed.

  In the present invention, preferably, the lower air electrode layer is formed of a material having higher catalytic activity than the upper air electrode layer, and the upper air electrode layer is formed of a material having higher conductivity than the lower air electrode layer.

  According to the present invention configured as described above, since the lower air electrode layer is formed relatively smoothly with a material having high catalytic activity, oxygen ions can be uniformly generated in each part of the air electrode layer, and stable. The generated power generation reaction can be generated. Further, since the upper air electrode layer is formed of a material having high conductivity (electron conductivity), electric charges can be transported to each part in the air electrode layer with low loss.

The present invention also relates to a manufacturing system for carrying out the method for manufacturing a solid oxide fuel cell according to the present invention, wherein the slurry for forming the fuel electrode layer is adhered to the fuel electrode layer so as to face the fuel electrode layer. A fuel electrode layer forming device for forming a film, an interconnector forming device for forming a film of an interconnector by droplets of a slurry for forming an interconnector, and continuously spraying the slurry on the fuel electrode layer An electrolyte layer forming apparatus for forming an electrolyte layer, an air electrode layer forming apparatus for forming a film of the air electrode layer by continuously injecting slurry for forming the air electrode layer into droplets, and a fuel And a heating furnace for heating the porous support on which the electrode layer, the electrolyte layer, and the air electrode layer are formed, and firing each layer.
Furthermore, the present invention is a solid oxide fuel cell produced by the method for producing a solid oxide fuel cell of the present invention.

  According to the solid oxide fuel cell, the manufacturing method, and the manufacturing apparatus of the present invention, a plurality of small power generation elements are formed on a single support even when the dimensional accuracy of the porous support is low. be able to.

1 is an overall configuration diagram showing a solid oxide fuel cell system incorporating a solid oxide fuel cell according to a first embodiment of the present invention. It is sectional drawing of the storage container of the solid oxide fuel cell by 1st Embodiment of this invention. 1 is a perspective view showing an entire solid oxide fuel cell according to a first embodiment of the present invention. It is sectional drawing which expanded and showed the functional layer formed in the porous support body surface of the solid oxide fuel cell by 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic front view showing an entire dot film forming apparatus that is a fuel cell manufacturing apparatus according to a first embodiment of the present invention. It is a schematic sectional drawing which shows the front-end | tip part of the jet dispenser with which the dot film-forming apparatus was equipped. 1 is a schematic front view showing an entire surface film forming apparatus which is a fuel cell manufacturing apparatus according to a first embodiment of the present invention. It is a flow which shows the operation | movement procedure of a surface film-forming apparatus. It is a flowchart which shows the procedure of the manufacturing method of the fuel cell by 1st Embodiment of this invention. In the fuel battery cell by 1st Embodiment of this invention, it is a schematic diagram which shows the lamination | stacking procedures, such as a functional layer, on a porous support body. It is a figure which shows the surface state of the air electrode layer after completion | finish of a 2nd baking process. It is an electron micrograph of each part of the fuel cell according to the first embodiment of the present invention. It is sectional drawing which expanded and showed the functional layer formed in the porous support body surface of the fuel cell by 2nd Embodiment of this invention.

Next, a solid oxide fuel cell (SOFC) according to an embodiment of the present invention will be described with reference to the accompanying drawings.
First, a solid oxide fuel cell according to a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is an overall configuration diagram showing a solid oxide fuel cell system incorporating a solid oxide fuel cell according to a first embodiment of the present invention. As shown in FIG. 1, the solid oxide fuel cell system 1 includes a fuel cell module 2 and an auxiliary unit 4.

  The fuel cell module 2 includes a housing 6, and a fuel cell storage container 8 is disposed inside the housing 6 via a heat insulating material 7. A power generation chamber 10 is formed inside the fuel cell storage container 8, and a plurality of fuel cell cells 16 (solid oxide fuel cell cells) are concentrically arranged in the power generation chamber 10. These fuel battery cells 16 perform a power generation reaction of air that is fuel gas and oxidant gas.

  An exhaust collecting chamber 18 is attached to the upper end of each fuel cell 16. The remaining fuel (off-gas) that is not used in the power generation reaction in each fuel cell 16 is collected in the exhaust collection chamber 18 attached to the upper end, and a plurality of fuel cells 16 provided on the ceiling surface of the exhaust collection chamber 18 are provided. It is discharged from the spout. The fuel that has flowed out is burned by the air remaining in the power generation chamber 10 without being used for power generation, and exhaust gas is generated.

  Next, the auxiliary unit 4 stores a water from a water supply source 24 such as a tap water and uses a filter to obtain pure water, and a water for adjusting the flow rate of the water supplied from the pure water tank. A water flow rate adjustment unit 28 (such as a “water pump” driven by a motor) as a supply device is provided. The auxiliary unit 4 also has a fuel blower 38 (a “fuel pump” driven by a motor) that is a fuel supply device that adjusts the flow rate of a hydrocarbon-based raw fuel gas supplied from a fuel supply source 30 such as city gas. Etc.).

  The raw fuel gas that has passed through the fuel blower 38 is introduced into the fuel cell storage container 8 via the desulfurizer 36 disposed in the fuel cell module 2, the heat exchanger 34, and the electromagnetic valve 35. . The desulfurizer 36 is annularly arranged around the fuel cell storage container 8 and removes sulfur from the raw fuel gas. The heat exchanger 34 is provided to prevent the high temperature raw fuel gas whose temperature has risen in the desulfurizer 36 from flowing directly into the electromagnetic valve 35 and degrading the electromagnetic valve 35. The electromagnetic valve 35 is provided to stop the supply of the raw fuel gas into the fuel cell storage container 8.

  The accessory unit 4 includes an air flow rate adjustment unit 45 (such as an “air blower” driven by a motor) that is an oxidant gas supply device that adjusts the flow rate of air supplied from the air supply source 40.

Further, the auxiliary unit 4 is provided with a hot water production device 50 for recovering the heat of the exhaust gas from the fuel cell module 2. The hot water production apparatus 50 is supplied with tap water, and the tap water is heated by the heat of the exhaust gas and supplied to a hot water storage tank of an external hot water heater (not shown).
Furthermore, the fuel cell module 2 is connected to an inverter 54 that is a power extraction unit (power conversion unit) for supplying the power generated by the fuel cell module 2 to the outside.

Next, the internal structure of the fuel cell storage container 8 will be described with reference to FIG. FIG. 2 is a cross-sectional view of the fuel cell storage container.
As shown in FIG. 2, a plurality of fuel cells 16 are concentrically arranged in a space in the fuel cell storage container 8, and a fuel gas supply channel 20 that is a fuel channel so as to surround the periphery thereof. An exhaust gas discharge passage 21 and an oxidant gas supply passage 22 are formed concentrically in order.

  First, as shown in FIG. 2, the fuel cell storage container 8 is a substantially cylindrical hermetic container, and an oxidant gas introduction pipe serving as an oxidant gas inlet for supplying air for power generation is provided on the side surface thereof. 56 and an exhaust gas exhaust pipe 58 for exhaust gas exhaust are connected. Further, an ignition heater 62 for igniting the remaining fuel that has flowed out of the exhaust collecting chamber 18 protrudes from the upper end surface of the fuel cell storage container 8.

  As shown in FIG. 2, inside the fuel cell storage container 8, an inner cylindrical member 64, which is a power generation chamber constituting member, an outer cylindrical member 66, an inner side in order from the inner side so as to surround the periphery of the fuel cell 16. A cylindrical container 68 and an outer cylindrical container 70 are arranged. The above-described fuel gas supply flow path 20, exhaust gas discharge flow path 21, and oxidant gas supply flow path 22 are flow paths configured between these cylindrical members and cylindrical containers, respectively, and between adjacent flow paths. Heat exchange takes place at. Further, the open space on the lower end side of the fuel cell storage container 8 is closed by a substantially circular dispersion chamber bottom member 72 that constitutes the bottom surface of the fuel gas dispersion chamber 76 that disperses the fuel into each fuel cell 16. .

A combustion catalyst 60 and a sheath heater 61 for heating the combustion catalyst 60 are disposed below the exhaust gas discharge passage 21.
The combustion catalyst 60 is a catalyst filled in an annular space between the outer peripheral surface of the outer cylindrical member 66 and the inner peripheral surface of the inner cylindrical container 68 above the exhaust gas discharge pipe 58. Exhaust gas descending the exhaust gas discharge passage 21 passes through the combustion catalyst 60 to remove carbon monoxide and is discharged from the exhaust gas discharge pipe 58.
The sheath heater 61 is an electric heater attached so as to surround the outer peripheral surface of the outer cylindrical member 66 below the combustion catalyst 60. When the solid oxide fuel cell device 1 is started, the combustion catalyst 60 is heated to the activation temperature by energizing the sheath heater 61.

  An annular space between the outer peripheral surface of the inner cylindrical container 68 and the inner peripheral surface of the outer cylindrical container 70 functions as the oxidant gas supply channel 22. Further, an oxidant gas introduction pipe 56 is connected to the lower side surface of the outer cylindrical container 70, and the oxidant gas supply flow path 22 communicates with the oxidant gas introduction pipe 56.

  A fuel gas dispersion chamber 76 is configured between the first fixing member 63 and the dispersion chamber bottom member 72. In addition, an insertion tube 72 a for inserting the bus bar 80 (FIG. 2) is provided at the center of the dispersion chamber bottom member 72. The bus bar 80 electrically connected to each fuel cell 16 is drawn out of the fuel cell storage container 8 through the insertion tube 72a.

  An oxidant gas injection pipe 74 having a circular cross section for injecting air for power generation is attached so as to hang down from the ceiling surface of the inner cylindrical container 68. The oxidant gas injection pipe 74 extends in the vertical direction on the central axis of the inner cylindrical container 68, and each fuel cell 16 is disposed on a concentric circle around it. The air supplied through the oxidant gas supply channel 22 is injected downward from the tip of the oxidant gas injection pipe 74, hits the upper surface of the first fixing member 63, and spreads throughout the power generation chamber 10.

  The fuel gas dispersion chamber 76 is a cylindrical airtight chamber formed between the first fixing member 63 and the dispersion chamber bottom member 72, and each fuel cell 16 is forested on the upper surface thereof. Each fuel cell 16 attached to the upper surface of the first fixing member 63 has an inner fuel electrode communicating with the inside of the fuel gas dispersion chamber 76. The lower end portion of each fuel cell 16 penetrates the insertion hole of the first fixing member 63 and protrudes into the fuel gas dispersion chamber 76, and each fuel cell 16 is fixed to the first fixing member 63 by bonding. Yes.

  As shown in FIG. 2, the supplied fuel once rises in the space between the inner periphery of the outer cylindrical member 66 and the outer periphery of the intermediate cylindrical member 65, and then the outer periphery of the inner cylindrical member 64 and the inner cylindrical member 65. The space between the circumferences descends and flows into the fuel gas dispersion chamber 76 through the plurality of small holes 64b. The fuel that has flowed into the fuel gas dispersion chamber 76 is distributed to the fuel electrode of each fuel cell 16 attached to the ceiling surface (first fixing member 63) of the fuel gas dispersion chamber 76.

  Further, the lower end portion of each fuel cell 16 projecting into the fuel gas dispersion chamber 76 is electrically connected to the bus bar 80 in the fuel gas dispersion chamber 76, and electric power is drawn out through the insertion tube 72a. The bus bar 80 is electrically connected to a current collector 82 attached to each fuel cell 16 inside the fuel gas dispersion chamber 76. The bus bar 80 is connected to the inverter 54 (FIG. 1) outside the fuel cell storage container 8. The current collector 82 is also attached to the upper end portion of each fuel cell 16 projecting into the exhaust collection chamber 18. The current collectors 82 at the upper end and the lower end connect the plurality of fuel cells 16 in parallel electrically, and connect the plurality of sets of fuel cells 16 connected in parallel electrically in series. The both ends of this series connection are connected to the bus bar 80, respectively.

  Next, the configuration of the exhaust collection chamber 18 will be described. The exhaust concentration chamber 18 is a donut-shaped cross-section chamber attached to the upper end of each fuel cell 16, and an oxidant gas injection pipe 74 extends through the center of the exhaust concentration chamber 18. . A plurality of circular insertion holes are provided on the bottom surface of the aggregation chamber 18. The upper end portions of the fuel cells 16 are inserted into the respective insertion holes. On the other hand, a plurality of jet outlets for jetting the aggregated fuel gas are provided on the ceiling surface of the exhaust aggregation chamber 18. The remaining fuel that is not used for power generation flows into the exhaust collecting chamber 18 from the upper end of each fuel battery cell 16, and the fuel collected in the exhaust collecting chamber 18 flows out from each jet port and burns there. .

Next, a configuration for reforming the raw fuel gas supplied from the fuel supply source 30 will be described with reference to FIG.
First, an evaporating portion 86 for evaporating water for steam reforming is provided at the lower portion of the fuel gas supply flow path 20. The evaporation unit 86 includes a ring-shaped inclined plate 86 a attached to the lower inner periphery of the outer cylindrical member 66 and a water supply pipe 88. The inclined plate 86 a is a metal thin plate formed in a ring shape, and its outer peripheral edge is attached to the inner wall surface of the outer cylindrical member 66. On the other hand, the inner peripheral edge of the inclined plate 86 a is positioned above the outer peripheral edge, and a gap is provided between the inner peripheral edge of the inclined plate 86 a and the outer wall surface of the inner cylindrical member 64.

  The water supply pipe 88 is a pipe that extends in the vertical direction from the lower end of the inner cylindrical member 64 into the fuel gas supply flow path 20, and the water supplied to the upper surface side of the inclined plate 86a is the upper surface of the inclined plate 86a and the outer cylindrical member. It stays between 66 inner walls. The water supplied to the upper surface side of the inclined plate 86a is evaporated there to generate water vapor.

  A fuel gas introduction part for introducing the raw fuel gas into the fuel gas supply channel 20 is provided below the evaporation part 86. The raw fuel gas sent from the fuel blower 38 is introduced into the fuel gas supply channel 20 via the fuel gas supply pipe 90. The raw fuel gas sent from the fuel blower 38 is introduced to the lower side of the inclined plate 86a and rises to the upper side of the inclined plate 86a while the flow path is restricted by the inclination of the inclined plate 86a. The raw fuel gas that has risen to the upper side of the inclined plate 86 a rises together with the water vapor generated in the evaporation section 86.

  A fuel gas supply channel partition wall 92 is provided above the evaporation portion 86 in the fuel gas supply channel 20. A plurality of injection ports 92 a are provided at equal intervals on the circumference of the fuel gas supply channel partition wall 92. The raw fuel gas introduced from the fuel gas supply pipe 90 and the water vapor generated in the evaporation portion 86 once stay in the space below the fuel gas supply flow path partition wall 92 and then pass through each injection port 92a to become fuel. The gas is injected into the space above the gas supply flow path partition wall 92 and mixed sufficiently here.

Further, a reforming portion 94 is provided in the upper part of the annular space between the inner periphery of the intermediate cylindrical member 65 and the outer periphery of the inner cylindrical member 64. The reforming unit 94 includes a catalyst holding plate (not shown) attached to the outer wall surface of the inner cylindrical member 64 and a reforming catalyst 96 held thereby. When the raw fuel gas and steam mixed in the space above the fuel gas supply flow path partition wall 92 come into contact with the reforming catalyst 96, the steam reforming reaction SR shown in Formula (1) is performed in the reforming unit 94. proceed.
C _m H _n + xH ₂ O → aCO ₂ + bCO + cH ₂ (1)

  The fuel gas reformed in the reforming section 94 flows downward in the space between the inner periphery of the intermediate cylindrical member 65 and the outer periphery of the inner cylindrical member 64, flows into the fuel gas dispersion chamber 76, and each fuel cell. 16 is supplied. Although the steam reforming reaction SR is an endothermic reaction, the heat required for the reaction is supplied by the combustion heat of the offgas flowing out from the exhaust collecting chamber 18 and the heat generated in each fuel cell 16.

Next, the structure of the fuel cell according to the first embodiment of the present invention will be described with reference to FIGS. 3 and 4.
FIG. 3 is a perspective view showing the whole fuel cell, and FIG. 4 is an enlarged cross-sectional view showing a functional layer formed on the surface of the porous support of the fuel cell.
As shown in FIG. 3, the fuel cell 16 (solid oxide fuel cell) of this embodiment is a cylindrical horizontal stripe cell using a solid oxide. On each fuel cell 16, a plurality of power generation elements 16 a are formed in a horizontal stripe shape, and one fuel cell 16 is configured by electrically connecting them in series. Each fuel cell 16 is configured such that one end thereof is an anode (anode) and the other end is a cathode (cathode), and half of the plurality of fuel cells 16 has an upper end as an anode and a lower end as a cathode. The other half are arranged so that the upper end is a cathode and the lower end is an anode.

  As shown in FIG. 4, the fuel battery cell 16 of the present embodiment includes a cylindrical porous support 97, a fuel electrode layer 98 that is three functional layers formed thereon, an electrolyte layer 100, and air. It has a polar layer 101. In the fuel cell 16, a plurality of power generation elements 16 a are formed by sequentially forming a fuel electrode layer 98, an electrolyte layer 100, and an air electrode layer 101 on a porous support 97. The fuel electrode layer 98 of each power generation element 16a functions as an anode, and the air electrode layer 101 functions as a cathode. Each of these power generating elements 16 a is electrically connected in series by the interconnector layer 102. In the present embodiment, twelve power generating elements 16 a are formed on one fuel battery cell 16, and these are connected by the interconnector layer 102.

  Specifically, as shown in FIG. 4, one end portion of the fuel electrode layer 98 constituting each power generation element 16 a and the opposite end portion of the air electrode layer 101 are extended. The extended end portion of the fuel electrode layer 98 that is the anode of the power generation element 16a is connected to the extended end portion of the air electrode layer 101 that is the cathode of the power generation element 16a that is disposed adjacently by the interconnector layer 102. ing.

Next, the structure of the porous support body 97 and each functional layer is demonstrated.
In this embodiment, the porous support 97 is formed by extruding a cylindrical mixture of a forsterite powder, which is an electrically insulating material, and adding a binder into a cylindrical shape, followed by sintering.
In this embodiment, the fuel electrode layer 98 is a conductive thin film composed of a mixture of NiO powder and 10YSZ (10 mol% Y ₂ O ₃ -90 mol% ZrO ₂ ) powder.

In the present embodiment, the solid electrolyte layer 100 is a thin film made of LSGM powder having a composition of La _0.9 Sr _0.1 Ga _0.8 Mg _0.2 O ₃ . Electric energy is generated by the reaction between oxide ions and hydrogen or carbon monoxide through the solid electrolyte layer 100.

In this embodiment, the air electrode layer 101 is a conductive thin film composed of LSCF powder having a composition of La _0.6 Sr _0.4 Co _0.8 Fe _0.2 O ₃ .
The interconnector layer 102, in this embodiment, SLT (lanthanum doped strontium titanate) and _{La 1-x Sr x Ti 1} -yz Nb y Fe z O 3 (LSTNF, 0.1 ≦ x ≦ 0.8,0.05 ≦ y ≦ 0.2 , 0.2 ≦ z ≦ 0.5).

Next, the fuel cell manufacturing apparatus according to the first embodiment of the present invention will be described.
First, a dot film forming apparatus used in a dot film forming process for forming a functional layer and the like will be described with reference to FIGS. FIG. 5 is a schematic front view showing the entire dot film forming apparatus, and FIG. 6 is a schematic cross-sectional view showing the tip of a jet dispenser provided in the dot film forming apparatus.

Each functional layer described above is formed by attaching a slurry in which a powder of a material constituting each functional layer is suspended to the porous support 97 and firing the slurry.
In each manufacturing process of the fuel battery cell 16, the dot film forming apparatus 110 forms each slurry for forming the interconnector and the air electrode layer in the form of droplets, and selectively selects only the portion where the dot film should be formed. It is comprised so that it may inject continuously. Further, the dot film forming apparatus 110 has a positioning function for forming an interconnector or an air electrode layer at a predetermined position.

  As shown in FIG. 5, the dot film forming apparatus 110 includes a pedestal 112, a motor 114 for rotating the porous support 97 on which the dot film is to be formed, and a fixing jig 116 that rotatably holds the porous support 97. A head portion 118 that ejects droplets, and a guide rail 120 that guides the head portion 118.

A motor 114 and a fixing jig 116 are installed on the pedestal 112.
The fixing jig 116 is configured to rotatably hold the porous support 97 on which the dot film is to be formed. That is, the fixing jig 116 holds the porous support 97 horizontally so as to sandwich the porous support 97 from both ends by inserting conical tailstocks 116a into both ends of the cylindrical porous support 97, respectively. Each mandrel 116a is configured to be rotatable about a horizontal rotation center line A, and the porous support body 97 held thereby is held to be rotatable about the rotation center line A. The motor 114 is configured to rotate the porous support 97 held by each tailstock 116a around the rotation center line A.

  Here, by supporting the cylindrical porous support body 97 sandwiched from both sides by the conical tailstock 116a, the porous support body 97 has its central axis and the rotational centerline A of the tailstock 116a. Hold to match. However, since the porous support body 97 is not completely cylindrical due to manufacturing errors, the rotation center line A and the central axis line of the porous support body 97 are slightly shifted in practice.

The head unit 118 includes a jet dispenser 122 that ejects slurry and the like in the form of droplets, a slurry container 124 that supplies the jet dispenser 122 with slurry and the like, and a camera 126 that captures an image of the porous support 97 on which dots are to be formed. And having.
The guide rail 120 is configured to move the head portion 118 in parallel with the rotation center line A. At the time of dot film formation, the porous support 97 is rotated while jetting droplet-like slurry from the jet dispenser 122, and the head portion 118 is sent along the guide rail 120 at a predetermined speed, thereby making the porous A belt-like slurry film can be formed around the support 97.

As shown in FIG. 6, the jet dispenser 122 includes a nozzle portion 128 that ejects slurry and the like, and an ejection actuator 129 that controls ejection.
The nozzle portion 128 is provided with an injection nozzle hole 128a oriented in the vertical direction, and a concave portion 128b wider than the injection nozzle hole 128a is formed at the upper end of the injection nozzle hole 128a. Further, a horizontal slurry supply passage 128c is formed in the nozzle portion 128 so as to communicate with the injection nozzle hole 128a. The slurry to be injected is injected from the slurry container 124 into the slurry supply passage 128c. The slurry or the like supplied from the slurry supply passage 128c flows into the injection nozzle hole 128a and is injected from the tip (lower end) of the injection nozzle hole 128a.

The ejection actuator 129 includes a flexible plate 129a and a protrusion 129b attached to the flexible plate 129a.
The flexible plate 129 a is a flexible rubber plate, and is attached so as to cover the recess 128 b provided in the nozzle portion 128. The protrusion 129 b is a metal protrusion attached to the central portion of the flexible plate 129 a and is received in the recess 128 b of the nozzle portion 128. A pulsating air pressure is applied to the back side of the flexible plate 129a (the opposite side of the recess 128b), and the flexible plate 129a bends due to the fluctuation of the air pressure, and a protrusion attached to the flexible plate 129a. 129b moves up and down.

  When the projection 129b is moved downward, the volume in the recess 128b that accommodates the projection 129b decreases, so that the slurry filled in the injection nozzle hole 128a and the recess 128b is made into droplets. Sprayed from the tip of the spray nozzle hole 128a. When the air pressure on the back side of the flexible plate 129a pulsates at a predetermined cycle, the protrusion 129b moves up and down, and droplets and the like are continuously ejected at a predetermined cycle. The ejected slurry droplets form dots on the porous support 97, and a slurry film is formed by the accumulation of the dots.

  The porous support body 97 is rotated by driving the motor 114, and the jet dispenser 122 is sent along the guide rail 120 at a predetermined speed, whereby the dots of the slurry are accumulated in horizontal stripes at desired positions on the porous support body 97. Can be made. The thickness of the layer formed by the dot film formation depends on the number of rotations of the motor 114, the feed speed of the jet dispenser 122, the size of droplets ejected from the jet dispenser 122, the viscosity of the slurry to be ejected, and the like. Can be controlled.

  The camera 126 is configured to take an image of the fuel electrode layer, the interconnector layer, and the like formed on the porous support 97, and specify the position of the boundary line by image analysis. Further, the horizontal distance L between the position on the image captured by the camera 126 and the ejection nozzle hole 128a from which the droplet is ejected is stored in advance in a memory (not shown). For this reason, the injection nozzle hole 128a can be moved to the position specified on the image by sending the head portion 118 by the distance L along the guide rail 120 from the position specified on the captured image. .

Next, a surface film forming apparatus used in the surface film forming process for forming the functional layer will be described with reference to FIGS. FIG. 7 is a schematic front view showing the entire surface film forming apparatus, and FIG. 8 is a flow showing an operation procedure of the surface film forming apparatus.
As shown in FIG. 7, the surface film forming apparatus 130 includes a pedestal 131, a fixing jig 132 provided on the pedestal 131, a motor 134 for rotating the fixing jig 132, and a surface component for discharging slurry. A film nozzle 136, a pump 138 that pumps slurry to the surface film forming nozzle 136, and a slurry container 139 that contains slurry to be supplied are provided.

  A fixing jig 132 is provided on the base 131. The fixing jig 132 supports the both ends of the porous support body 97 so that the porous support body 97 is oriented in the horizontal direction. The motor 134 is connected to the fixing jig 132 so that the fixing jig 132 and the porous support 97 supported by the fixing jig 132 are rotated at a predetermined rotational speed around the central axis of the porous support 97. It is configured.

The surface film forming nozzle 136 is disposed immediately below the porous support 97 supported by the fixing jig 132, and is configured to discharge the slurry upward toward the porous support 97.
The pump 138 is configured to suck up the slurry in the slurry container 139 and discharge the slurry from the surface film forming nozzle 136 at a predetermined flow rate.

  The surface film forming nozzle 136 is provided with slit-like elongated nozzle holes (not shown) so that the slurry is uniformly discharged over the entire surface of the porous support 97 to be formed. ing. The slurry discharged from the surface film forming nozzle 136 is attached to the porous support 97 disposed in the horizontal direction immediately above, and each functional layer of the plurality of power generating elements 16a formed on the porous support 97 is simultaneously formed. A film is formed. Note that a portion on the porous support 97 that does not require surface film formation is masked in advance by a dot film formation apparatus 110 as described later. Slurry remaining without adhering to the porous support 97 flows down around the surface film forming nozzle 136 and is collected.

Next, with reference to FIG. 8, a surface film forming procedure will be described.
First, in step S <b> 101 of FIG. 8, the porous support 97 to be surface-formed is fixed to the fixing jig 132. Note that masking is performed in advance on a portion on the porous support 97 where surface film formation is unnecessary. Next, in step S102, the motor 134 is activated, and the porous support 97 is rotated at a predetermined rotational speed around its central axis. Further, in step S103, the pump 138 is operated. Thereby, the slurry is sucked up from the slurry container 139, and the slurry is pumped toward the surface film-forming nozzle 136 (step S104). The slurry fed under pressure is discharged upward from the surface film forming nozzle 136 (step S105). The slurry discharged from the surface film forming nozzle 136 is applied to the surface of the porous support 97 rotating above the surface film forming nozzle 136 (step S106).

The slurry remaining without adhering to the porous support 97 flows down around the surface film forming nozzle 136. Further, excess slurry adhering to the porous support 97 flows down by the centrifugal force of the rotating porous support 97, and a slurry film having a predetermined thickness is formed on the porous support 97. . Accordingly, the thickness of the layer formed on the porous support 97 can be controlled by the number of rotations of the porous support 97, the discharge flow rate from the surface film forming nozzle 136, the viscosity of the slurry, and the like.
Next, the pump 138 is stopped in step S107, and the motor 134 is stopped in step S108. Further, in step S109, the formed porous support body 97 is removed from the fixing jig 132, and the surface film forming step is completed.

  The dot film forming apparatus 110, the surface film forming apparatus 130, and the heating furnace for firing the formed functional layer described above constitute a solid oxide fuel cell manufacturing system.

Next, with reference to FIG.9 and FIG.10, the manufacturing method of the solid oxide fuel cell by 1st Embodiment of this invention is demonstrated.
FIG. 9 is a flowchart showing a procedure of the manufacturing method of the present embodiment, and FIG. 10 is a schematic diagram showing a procedure for stacking functional layers and the like on the porous support. FIG. 10 schematically shows the overlap of the functional layers and the like, and does not show the specific cross-sectional shape and dimensions of each layer.

First, in step S1 of FIG. 9, a forsterite porous support 97 is formed as a support forming process. Specifically, a clay-like material obtained by adding a binder to forsterite powder is extruded into a cylindrical shape by an extruder (not shown).
Next, in step S2, the porous support body 97 extruded in step S1 is heated in a heating furnace (not shown) and temporarily fired as a temporary firing step. In this embodiment, the molded body of the porous support body 97 is heated in a heating furnace at about 1000 ° C. for about 2 hours and pre-baked. This temporarily fired porous support body 97 made of forsterite is a generally white electrical insulator.

  Next, in step S3, as a first masking formation step, a masking agent is applied to the porous support 97 that has been pre-fired in step S2, and the masking layer 104 is formed. Specifically, in this first masking formation step, the masking layer 104 is dot-formed by the dot film-forming device 110. That is, in the first masking formation step, the jet dispenser 122 (FIG. 5) of the dot film forming apparatus 110 continuously jets the masking agent in the form of droplets onto the area where the masking layer 104 is to be formed. In this process, dots of the mask forming agent are formed on the porous support member 97, and the masking layer 104 is formed into dots by accumulating the dots. Therefore, in the first masking formation step, the dot film forming device 110 functions as a masking layer forming device.

  As shown in FIG. 10A, the masking layer 104 is formed on the porous support 97 where the fuel electrode layer 98 is not required to be formed. If the viscosity of the masking agent is too low, the masking agent penetrates deeply into the porous support 97, which is a superporous material. Therefore, the masking agent is formed many times to form the masking layer 104 having a predetermined thickness. A membrane is required, and the production efficiency is reduced. Further, the penetration of the mask forming agent makes the region where the masking layer 104 is formed inaccurate. On the other hand, when the viscosity of the mask forming agent is too high, the smoothness of the surface of the formed masking layer 104 becomes insufficient. In this case, when the surface film is formed in the next step, the slurry is accumulated on the masking layer 104, and this slurry remains in an unnecessary part of the film formation. In this embodiment, the masking agent is adjusted to an appropriate viscosity.

  The masking layer 104 formed with dots is naturally dried after the masking agent is applied. In the present embodiment, Fluorosurf (trademark) FS-1000 series or FG-3020 series manufactured by Fluoro Technology Co., Ltd. is used as a masking agent.

  In the first masking formation step, the position where the masking layer 104 is to be formed is determined based on the fixing jig 116 provided in the dot film forming apparatus 110. That is, the dot film forming apparatus 110 moves the head portion 118 a predetermined distance from the position of the fixing jig 116 stored in advance, and rotates the porous support 97 from the position to form the dot film on the masking layer 104. To start. All the masking layers 104 formed in the first masking forming step are positioned by the feed amount of the head portion 118 with reference to the position of the fixing jig 116, and masking is performed by the moving distance of the head portion 118 from that position. The width of the layer 104 is set.

  For this reason, the masking layer 104 formed in the first masking formation step is formed in an annular shape orthogonal to the rotation axis A of the dot film forming apparatus 110. Therefore, when the porous support body 97 is bent due to a manufacturing error or the like, the masking layer 104 is not accurately orthogonal to the central axis of the porous support body 97. However, such an error does not cause a problem in the fuel battery cell 16, and the masking layer 104 is formed so as to be orthogonal to the rotational axis A of the dot film forming apparatus 110, thereby responding to the deflection of the porous support 97. There is no need to perform position correction or the like, and film formation can be performed easily. In addition, according to the dot film formation, the masking layer 104 is formed by the accumulation of the dots of the ejected droplets, so that the flexure of the porous support member 97 causes the jet dispenser 122 and the porous support member 97 surface to move. Even when the distance is changed, the thickness of the formed layer is not directly affected. For this reason, even when there is a manufacturing error in the porous support 97, the layer can be formed with an accurate thickness.

  Further, in the first masking layer forming step, the feed of the dot film forming device 110 is adjusted so that the central portion of the masking layer 104 is formed in a raised convex shape. That is, at the start of the formation of each masking layer 104, the amount of overlap in the axial direction of the formed dots is reduced by increasing the feed amount in the axial direction of the jet dispenser 122 of the dot film forming apparatus 110. The masking layer 104 is thinned. Thereafter, by gradually decreasing the feed amount of the jet dispenser 122, the overlapping amount of dots to be formed is increased, and the masking layer 104 is made thicker. At the end of formation of one masking layer 104, the amount of overlap of the jet dispenser 122 in the axial direction is gradually increased to reduce the overlapping amount of dots in the axial direction, thereby making the masking layer 104 thinner. In this way, by forming the masking layer 104 in a high and convex central portion, the slurry contacted from above the masking layer 104 in the next fuel electrode layer forming step quickly flows out of the masking layer 104. As a result, it is possible to suppress a large amount of slurry from being deposited on the masking layer 104 and forming a fuel electrode layer in unnecessary portions.

  Next, in step S4, as a fuel electrode layer forming step, the fuel electrode layer 98, which is one of the functional layers of the power generation element 16a, is formed on the porous support body 97 on which the masking layer 104 is formed in step S3. A film is formed. Specifically, in the fuel electrode layer forming step which is the first surface film forming step, the slurry for forming the fuel electrode is brought into contact with the porous support 97 from above the masking layer 104, The fuel electrode layer 98 is formed on the surface where there is not. That is, in step S3, the porous support body 97 on which the masking layer 104 is formed is fixed to the fixing jig 132 of the surface film forming apparatus 130, and the porous support body 97 is rotated and discharged from the lower surface film forming nozzle 136. The slurry to be applied is applied from above the masking layer 104. Accordingly, in the fuel electrode layer forming step, the surface film forming device 130 functions as a fuel electrode layer forming device.

  This fuel electrode layer forming step is a lower layer surface film forming step in which surface film formation is performed on the lowermost side, and each fuel electrode layer 98 of all the power generating elements 16a formed on one porous support 97 is formed. This is a surface film forming step in which surface film formation is performed simultaneously. In this way, in the fuel electrode layer forming step, the fuel electrode layer 98 is formed by surface film formation, so that no dot marks remain in the dot film formation, and the surface of the fuel electrode layer 98 is formed smoothly. Can do.

  In the present embodiment, the slurry used in the fuel electrode layer forming step is a liquid in which a mixture of NiO powder and 10YSZ powder is suspended in an alcohol-based solvent, while the masking layer 104 is formed. The agent is oil repellent. For this reason, the slurry is brought into contact with the entire porous support 97 from above the masking layer 104, but the slurry on the masking layer 104 is repelled by the masking agent and does not deposit on the masking layer 104. . As a result, as shown in FIG. 10B, the fuel electrode layer film is formed only in the portion where the masking layer 104 is not provided. Furthermore, as shown in FIG. 4, since the slurry deposited on the porous support 97 is repelled by the oil repellent mask forming agent and does not adhere to the masking layer 104, the edges are rounded by the surface tension of the slurry. Is deposited. In this embodiment, an oil-repellent material is used as the mask forming agent. However, depending on the slurry used, a water-repellent mask forming agent can also be used.

  Further, in the fuel electrode layer forming step, after the fuel electrode layer film is formed on the porous support 97, a drying step (not shown) for drying the deposited slurry is performed. In the present embodiment, in the drying step, the slurry is dried at about 100 ° C. for about 5 minutes. Note that the masking layer 104 formed on the porous support 97 is maintained as it is even after the drying step.

  Next, in step S5, a temporary baking process is performed. In the pre-baking step, the porous support 97 on which the fuel electrode layer film is formed in step S4 is heated by a heating furnace (not shown) and pre-baked. As shown in FIG. 10C, the masking layer 104 formed on the porous support body 97 is evaporated and disappears by the pre-baking step, and the porous support body 97 under the masking layer 104 is exposed. Is done. In the present embodiment, the fuel electrode layer 98 is heated and cured at about 1000 ° C. for about 2 hours in a heating furnace. The color of the temporarily fired NiO / YSZ fuel electrode layer 98 is generally light green.

  Next, in step S6, as a first interconnector forming process, an interconnector layer is formed on the fuel electrode layer 98 pre-fired in step S5 by the dot film forming apparatus 110. Specifically, in the first interconnector forming step, the first interconnector layer 102a that is a part of the interconnector layer 102 is formed by dot film formation. That is, in the first interconnector forming step, the slurry for forming the first interconnector layer 102a is continuously sprayed in the form of droplets onto the region where the first interconnector layer 102a is to be formed. This is a dot film forming step in which dots of slurry are formed in a predetermined region on the fuel electrode layer 98, and the first interconnector layer 102a is formed by accumulation of the dots. Accordingly, in the first interconnector forming step, the dot film forming device 110 functions as an interconnector forming device. In the present embodiment, a liquid in which LSTNF powder is suspended in an alcohol solvent can be used as the slurry for forming the first interconnector layer 102a.

  As shown in FIG. 10 (d), the first interconnector layer 102 a is formed on one end of each fuel electrode layer 98. The positioning of the part forming the first interconnector layer 102a is executed based on image analysis. That is, the porous support 97 fixed to the fixing jig 116 of the dot film forming apparatus 110 is imaged by the camera 126, and the portion where the fuel electrode layer 98 is formed on the porous support 97 is formed. The boundary line of the missing part is identified by image analysis. Based on the position of the specified boundary line, the first interconnector layer 102a is formed in a dot pattern in a predetermined region on the fuel electrode layer 98. This boundary line is specified for each fuel electrode layer 98 formed on the porous support 97.

  In the first masking formation process of step S3 in FIG. 9, positioning is performed with reference to the fixing jig 116, but in the first interconnector forming process, image analysis is used as the first positioning process. Then, positioning is performed based on the position of each fuel electrode layer 98. For this reason, the first interconnector layer 102a can be accurately aligned with each fuel electrode layer 98 regardless of the shrinkage of the porous support 97 due to pre-baking or the change in the attachment position of the porous support 97. . Further, the masking layer 104 for forming the fuel electrode layer 98 is formed so as to be orthogonal to the rotation center line A of the porous support 97. For this reason, the edge of the fuel electrode layer 98 is formed so as to be orthogonal to the rotation center line A, and the fuel electrode layer 98 and the porous support body 97 are positioned at any rotational position. The position of the boundary line is constant, and the formation position of the first interconnector layer 102a can be uniquely determined. In the present embodiment, since the porous support 97 is substantially white and the fuel electrode layer 98 is light green, the brightness contrast is high, and image analysis can be performed accurately even with a monochrome captured image. it can. Further, by performing image analysis based on a monochrome image, the processing time required for image analysis can be shortened.

  Further, in the first interconnector forming step, after the film of the first interconnector layer 102a is formed, a drying step (not shown) for drying the deposited slurry is performed. In the present embodiment, in the drying step, the slurry is dried at about 100 ° C. for about 10 minutes.

  Next, a temporary baking process is implemented in step S7. In the pre-baking process, the porous support 97 on which the film of the first interconnector layer 102a is formed in step S6 is heated by a heating furnace (not shown) and pre-baked. By this temporary firing step, the film of the first interconnector layer 102a formed on each fuel electrode layer 98 is cured. In the present embodiment, the first interconnector layer 102a is heated in a heating furnace at about 1000 ° C. for about 2 hours. The color of the pre-fired LSTNF first interconnector layer 102a is generally brown.

  Next, in step S8, as a second masking formation process, a mask forming agent is applied to the first interconnector layer 102a preliminarily baked in step S7 by the dot film forming apparatus 110, and the masking layer 106 is formed. That is, in the second masking formation step, the masking agent is continuously ejected in the form of droplets onto the area where the masking layer 106 is to be formed, thereby forming the masking agent dots on the first interconnector layer 102a. And forming a masking layer 106 by accumulating the dots.

  As shown in FIG. 10 (e), the masking layer 106 is formed on the first interconnector layer 102a so as to cover the first interconnector layer 102a, leaving the end portions on both sides thereof. The positioning of the position where the masking layer 106 is formed is executed by image analysis using the camera 126 of the dot film forming apparatus 110 as the second positioning process. Since the first interconnector layer 102a is brown, the porous support body 97 is substantially white, and the fuel electrode layer 98 is light green, the brightness contrast is high, and it can be accurately positioned by the captured image. The dot-formed masking layer 106 is naturally dried after the masking agent is applied. The mask forming agent used in the second mask forming step is the same as the mask forming agent used in the first mask forming step.

  Next, in step S9, as an electrolyte layer forming step, the electrolyte layer 100, which is one of the functional layers of the power generation element 16a, is formed on the porous support 97 on which the masking layer 106 is formed in step S8. Is done. Specifically, in the electrolyte layer forming step which is the second surface film forming step, the slurry for forming the electrolyte layer is brought into contact with the porous support 97 from above the masking layer 106 by the surface film forming apparatus 130. The electrolyte layer 100 is formed on the surface where the masking layer 106 is absent. Accordingly, in the electrolyte layer forming step, the surface film forming apparatus 130 functions as an electrolyte layer forming apparatus. This electrolyte layer forming step is an upper surface film forming step in which surface film formation is performed on the fuel electrode layer 98 having a surface film formed, and all the power generation elements 16a formed on one porous support 97 are formed. This is a surface film forming step in which the respective electrolyte layers 100 are formed simultaneously.

  In the present embodiment, the slurry used in the electrolyte layer forming step is a liquid in which LSGM powder is suspended in an alcohol solvent. This slurry is brought into contact with the entire porous support 97 from above the masking layer 106, but the slurry is repelled by the masking layer 106 and does not deposit on the masking layer 106. As a result, as shown in FIG. 10F, the film of the electrolyte layer 100 is formed only in a portion where the masking layer 106 is not present. That is, all exposed portions of the porous support 97 and the fuel electrode layer 98 and the edge portions on both sides not covered with the masking layer 106 of the first interconnector layer 102a are covered with the membrane of the electrolyte layer 100.

  Also, as shown in FIG. 4, since the edge of the fuel electrode layer 98 is formed in a round shape, the slurry of the electrolyte layer 100 laminated thereon is the boundary between the fuel electrode layer 98 and the porous support 97. It is possible to prevent the formation of voids under the electrolyte layer 100 without entering the gap. Furthermore, since the slurry to form the electrolyte layer 100 is repelled by the masking layer 106 and does not adhere to the masking layer 106, the edges are deposited rounded by the surface tension. In the electrolyte layer forming step, since the electrolyte layer 100 is formed by surface film formation, no dot marks are generated, and a smooth surface can be obtained. In addition, since the electrolyte layer 100 is formed on the fuel electrode layer 98 that is surface-formed, the smoothness is not impaired by the unevenness of the surface of the lower layer.

  Further, in the electrolyte layer forming step, after the membrane of the electrolyte layer 100 is formed on the porous support 97, a drying step (not shown) for drying the deposited slurry is performed. In the present embodiment, in the drying step, the slurry is dried at about 100 ° C. for about 5 minutes. Note that the masking layer 106 formed on the porous support 97 is maintained as it is even after the drying step.

  Next, in step S10, a temporary baking process is performed. In the pre-baking step, the porous support 97 on which the electrolyte layer 100 film is formed in step S10 is heated by a heating furnace (not shown) and pre-baked. As shown in FIG. 10G, the masking layer 106 formed on the first interconnector layer 102a evaporates and disappears by the temporary firing step. As a result, the portion of the first interconnector layer 102a that was covered with the masking layer 106 is exposed. In this embodiment, the electrolyte layer 100 is heated and cured at about 1000 ° C. for about 2 hours in a heating furnace. The color of the calcified electrolyte layer 100 made of LSGM is generally skin color.

  Next, in step S11, as a second interconnector forming step, a second interconnector layer is formed so as to be electrically connected to the first interconnector layer 102a exposed by the preliminary firing in step S10. Specifically, as shown in FIG. 10 (h), in the second interconnector forming step, the exposed first interconnector layer 102a and the edge of the electrolyte layer 100 adjacent to the exposed portion are covered. The second interconnector layer 102 b is formed by the dot film forming apparatus 110. That is, in the second interconnector forming step, the slurry for forming the second interconnector layer 102b is continuously ejected in the form of droplets onto the region where the second interconnector layer 102b is to be formed. This is a dot film forming process in which dots of slurry are formed in a predetermined region and the second interconnector layer 102b is formed by accumulation of the dots. Accordingly, in the second interconnector forming step, the dot film forming device 110 functions as an interconnector forming device.

  In the present embodiment, as a slurry for forming the second interconnector layer 102b, a liquid in which SLT powder is suspended in an alcohol-based solvent can be used. Thus, in this embodiment, the 1st interconnector layer 102a and the 2nd interconnector layer 102b are formed with a different material. Furthermore, in the second interconnector forming step, after the film of the second interconnector layer 102b is formed, a drying step (not shown) for drying the deposited slurry is performed. In the present embodiment, in the drying step, the slurry is dried at about 100 ° C. for about 10 minutes. In the second interconnector forming step, the positioning of the portion forming the second interconnector layer 102b is executed using image analysis as the third positioning step. In the third positioning step, the boundary lines are specified based on the color difference between the first interconnector layer 102a and the electrolyte layer 100 that have been pre-fired.

  Next, in step S12, a first baking process is performed. In the first firing step, the porous support 97, the fuel electrode layer 98, the electrolyte layer 100, the first interconnector layer 102a, and the second interconnector layer 102b formed up to step S11 are heated in a heating furnace (not shown). ) And fired. Thereby, the porous support body 97 and each functional layer formed on it are integrated. In this embodiment, in a 1st baking process, it heats with a heating furnace at about 1300 degreeC for about 2 hours. In the present embodiment, after the first firing step, the electrolyte layer 100 is generally black and the second interconnector layer 102b is also black, but the end of the second interconnector layer 102b that overlaps the electrolyte layer 100 is approximately It is white.

  Next, in step S13, as an air electrode layer forming step, an air electrode layer that is the outermost functional layer is formed on the electrolyte layer 100 baked in step S12. Specifically, as shown in FIG. 10 (i), in the air electrode layer forming process which is the outermost layer film forming process, the dot formation is performed so as to cover the second interconnector layer 102 b and a part of the electrolyte layer 100. The air electrode layer 101 is formed by the membrane device 110. That is, in the air electrode layer forming step, the slurry for forming the air electrode layer 101 is continuously sprayed in the form of liquid droplets onto the area where the air electrode layer 101 is to be formed, so that the slurry is applied to a predetermined area. This is a dot film forming process in which the air electrode layer 101 is formed by collecting the dots. Accordingly, in the air electrode layer forming step, the dot film forming device 110 functions as an air electrode layer forming device.

  Further, in the air electrode layer forming step, as shown in FIG. 4, the feed of the dot film forming apparatus 110 is adjusted so that the thickness of the edge of the air electrode layer 101 is thinner than the thickness of the central part. . That is, at the start of the formation of each air electrode layer 101, the amount of overlap in the axial direction of the formed dots is reduced by increasing the feed amount in the axial direction of the jet dispenser 122 of the dot film forming apparatus 110. The air electrode layer 101 is thinned. Thereafter, by gradually reducing the feed amount of the jet dispenser 122, the overlapping amount of dots to be formed is increased and the air electrode layer 101 is made thicker. At the end of the formation of one air electrode layer 101, the amount of overlap of the jet dispenser 122 in the axial direction is gradually increased to reduce the overlapping amount of dots in the axial direction, thereby making the air electrode layer 101 thinner. Thus, by forming the edge of the air electrode layer 101 thin, it is possible to prevent the air electrode layer 101 that is the outermost functional layer from being peeled after firing.

  In the present embodiment, a liquid in which LSCF powder is suspended in an alcohol solvent can be used as a slurry for forming the air electrode layer 101. In the air electrode layer forming process, the positioning of the portion where the air electrode layer 101 is formed is executed using image analysis as the fourth positioning process. In the fourth positioning step, the boundary line is specified based on the color difference between the end of the second interconnector layer 102b and the electrolyte layer 100 after the first firing step. Further, in the air electrode layer forming step, after the film of the air electrode layer 101 is formed, a drying step (not shown) for drying the deposited slurry is performed. In the present embodiment, in the drying step, the slurry is dried at about 100 ° C. for about 10 minutes.

  Next, in step S14, a second baking process is performed. In the second firing step, the air electrode layer 101 formed in step S13 is heated and fired by a heating furnace (not shown). Thereby, the air electrode layer 101 is integrated with the electrolyte layer 100 and the second interconnector layer 102b formed on the lower side thereof. In the present embodiment, in the second firing step, heating is performed at about 1000 ° C. for about 2 hours in a heating furnace.

The fuel cell 16 of this embodiment is completed by this second firing step.
FIG. 11 is a view showing the surface state of the air electrode layer 101 after the second firing step, FIG. 11 (a) is an enlarged photograph of the surface of the air electrode layer 101, and FIG. 11 (b) corresponds to the enlarged photograph. It is a figure which shows typically each dot formed in the part to do.

  As shown in FIG. 11A, the surface of the fired air electrode layer 101 has minute cracks at positions corresponding to the edges of the dots. This is because the air electrode layer 101 on which the dot film is formed shrinks in the second baking step, and a minute crack is generated on the surface. Here, in the air electrode layer forming step (step S13), while rotating the porous support body 97 on which the layers up to the second interconnector layer 102b are rotated, the jet dispenser 122 is moved along the guide rail 120. , Slurry droplets are continuously ejected. For this reason, each dot formed when each droplet adheres is arranged so as to draw a spiral while overlapping each other in the circumferential direction and the axial direction.

In the present embodiment, the dots formed by one droplet discharged from the jet dispenser 122 are generally circular with a diameter of about 500 μm, and the dot traces remain on the surface appropriately. By forming the air electrode layer 101 in this way, a minute crack is generated on the surface of the air electrode layer 101, and the surface shape can absorb the shrinkage caused by firing. Preferably, the diameter of the injection nozzle hole 128a of the jet dispenser 122, the viscosity of the slurry, and the like are adjusted so that dots having a diameter of about 200 μm to 1000 μm are formed.
In addition, as a modification, the dot film forming apparatus 110 can be configured so that substantially oval dots are formed. In this case, the length of the long axis of the dots is about 200 μm to 1000 μm. good. The shape of the dots can be appropriately set according to the shape of the ejection nozzle hole 128a, the rotational speed (rpm) of the porous support 97, the interval at which droplets are ejected, the viscosity of the slurry, and the like. Thus, by making each dot of the slurry collected in the air electrode layer forming step into an oval shape, it is possible to increase the overlap at the time of accumulation and enhance the effect of suppressing peeling. In addition, by setting the major axis length of the oval dot to about 200 μm to 1000 μm, it is possible to sufficiently absorb the influence of the thermal expansion of the air electrode layer 101 and prevent peeling, and the air electrode The time required for the layer forming process can also be shortened.

  FIG. 11B schematically shows the arrangement of dots formed in this way. In FIG. 11B, first, the dots I are formed, and then the dots II are formed so as to partially overlap the dots I with the porous support 97 slightly rotated. Subsequently, the dots III and IV are sequentially formed so as to partially overlap. As described above, when the dots are sequentially arranged and the porous support member 97 rotates once and returns to the position of the dot I, the jet dispenser 122 is sent to the position of the dot V in the axial direction, and the dot V is the axial line. It is formed so as to partially overlap the dot I in the direction. Subsequently, the dots VI and VII are sequentially formed so as to partially overlap.

  Since the dots are arranged in this way, for example, the boundary line exposed on the surface of the air electrode layer 101 in the dot II is only the portion indicated by B in FIG. This part is covered with other dots and is not exposed on the surface. For this reason, even if a crack occurs in the exposed boundary line, the other part of the boundary line is pressed by another dot, so that the dot does not fall off due to the crack. Further, by generating minute cracks on the surface of the air electrode layer 101, the strain caused by the difference in thermal expansion coefficient during firing is dispersed and the stress can be absorbed. For this reason, large peeling does not occur in the air electrode layer 101.

  An electron micrograph of each part of the fuel cell 16 thus completed is shown in FIG. 12A shows an electron micrograph of the porous support 97, FIG. 12B shows a fuel electrode layer 98, FIG. 12C shows an electrolyte layer 100, and FIG. 12D shows an electron micrograph of the air electrode layer 101.

  As shown in FIG. 12A, the porous support 97 is a structure for supporting each functional layer, and the higher the fuel gas permeability is, the more preferable it is, and it has a superporous structure. As shown in FIG. 12 (b), the fuel electrode layer 98 functions as a conductor carrying the charge generated by the power generation reaction as well as the function of permeating hydrogen molecules of the fuel gas. It is porous with few voids. Similarly, as shown in FIG. 12 (d), the air electrode layer 101 also functions as a conductor that carries the charge generated by the power generation reaction together with the function of transmitting oxygen molecules in the air. The porosity is less than 97. Further, as shown in FIG. 12C, the electrolyte layer 100 is densely configured to generate a power generation reaction and to ensure airtightness on the fuel electrode side and the air electrode side.

  In FIG. 10 (i), the portion in which the fuel electrode layer 98, the electrolyte layer 100, and the air electrode layer 101 are sequentially laminated on the porous support 97 is a power generation unit formed on the fuel cell 16. It functions as each power generating element 16a. The electric charges generated in these power generation elements 16a are transported through the air electrode layer 101 of the current collector (the portion where only the electrolyte layer 100 and the air electrode layer 101 are laminated on the porous support 97), Adjacent via a connecting portion (a portion where the fuel electrode layer 98, the first interconnector layer 102a, the second interconnector layer 102b, the electrolyte layer 100, and the air electrode layer 101 are sequentially laminated on the porous support 97) Connected to the anode of the power generating element 16a. In addition, the portion where the second interconnector layer 102b and the air electrode layer 101 are not formed on the electrolyte layer 100 (the portion where the electrolyte layer 100 is exposed) is between the air electrode layers 101 of the adjacent power generation elements 16a. Functions as an insulating part for insulation.

  According to the method for manufacturing the solid oxide fuel cell of the first embodiment of the present invention, the fuel electrode layer 98 formed immediately above the porous support 97 is formed by surface film formation (step S4 in FIG. 9). The interconnector 102 and the air electrode layer 101 which are formed and formed thereon are formed by accumulation of the slurry dots (steps S6 and S13 in FIG. 9). Thus, since the lowermost fuel electrode layer 98 is formed by surface film formation, the fuel electrode layer 98 with high smoothness can be formed, and adverse effects on the electrolyte layer 100 and the like on the upper layer can be suppressed. it can. On the other hand, when the fuel electrode layer 98 is formed by accumulation of dots, the smoothness of the surface of the fuel electrode layer 98 is lowered. Therefore, when the fuel electrode layer 98 is subjected to the reduction treatment, There is a possibility of adversely affecting the functional layer laminated on the substrate. This is because when the fuel electrode layer 98 is subjected to reduction treatment, the volume is reduced because oxygen is lost from the inside of the layer. That is, peeling or the like occurs between the electrolyte layer 100 formed on the substrate.

  In addition, according to the manufacturing method of the solid oxide fuel cell of the present embodiment, the interconnector 102 is formed by the accumulation of dots, so even if the dimensional accuracy of the porous support 97 is low, the interconnector 102 Can be easily formed with high dimensional accuracy and position accuracy. Further, since the interconnector 102 is small, even when it is formed by dot accumulation, the film formation does not take a long time, and the manufacturing efficiency is not lowered. Furthermore, according to the present embodiment, since the air electrode layer 101 is also formed by dot accumulation, it can be easily formed with high dimensional accuracy and position accuracy. In addition, since the reduction treatment is not performed on the air electrode layer 101, even if the surface is formed by accumulation of dots and the smoothness of the surface is low, there is no adverse effect due to the shape change.

  As described above, according to the present embodiment, the lowermost fuel electrode layer 98, the interconnector 102 formed above the fuel electrode layer 98, and the air electrode layer 101 are each formed by an appropriate film forming method. Even when the dimensional accuracy of the quality support 97 is low, a plurality of small power generation elements 16a can be formed on the single porous support 97, and adverse effects associated with the reduction process can be avoided.

  Further, according to the method for manufacturing the solid oxide fuel cell of the present embodiment, since the porous support body 97 is formed of an insulating material, the fuel electrode layers 98 of the respective power generation elements 16a are separated from each other. By being formed on the porous support 97, they are insulated from each other. Here, in the case where the fuel electrode layer 98 is formed by accumulation of dots, if the viscosity of the slurry to be injected is low, the slurry penetrates into the porous support body 97, and between the fuel electrode layers 98 formed apart from each other. There is a risk of short circuit. Further, when the viscosity of the slurry to be sprayed is increased, the penetration of the slurry can be avoided. However, since each dot to be formed becomes smaller, the time required for dot film formation becomes longer and the production efficiency is increased. Is significantly reduced. According to this embodiment, since the fuel electrode layer 98 is formed by surface film formation (step S4 in FIG. 9), the viscosity of the slurry for forming the fuel electrode layer 98 is increased and the slurry is supported porously. The fuel electrode layer 98 can be efficiently formed while preventing penetration into the body 97.

Next, a solid oxide fuel cell according to a second embodiment of the present invention will be described with reference to FIG.
The fuel cell according to the second embodiment of the present invention is different from the first embodiment described above in that the fuel electrode layer, the electrolyte layer, and the air electrode layer, which are three functional layers, are each formed of two layers. Is different. Accordingly, here, only the points of the second embodiment of the present invention that are different from the first embodiment will be described, and descriptions of similar configurations, operations, and effects will be omitted.

FIG. 13 is an enlarged cross-sectional view of a functional layer formed on the porous support surface of the fuel cell according to the second embodiment of the present invention.
As shown in FIG. 13, the fuel cell 200 of the present embodiment includes a cylindrical porous support 202, a fuel electrode layer 204 that is three functional layers formed thereon, an electrolyte layer 206, and air. It has a polar layer 208. In the fuel cell 200, a plurality of power generation elements 200 a are formed by sequentially forming a fuel electrode layer 204, an electrolyte layer 206, and an air electrode layer 208 on a porous support 202. Each of these power generating elements 200a is electrically connected in series by an interconnector layer 210. In the present embodiment, twelve power generating elements 200 a are formed on one fuel battery cell 200, and these are connected by an interconnector layer 210.

Next, the structure of the porous support body 202 and each functional layer will be described.
In the present embodiment, the porous support 202 is formed by extruding and sintering a mixture containing forsterite powder as a main component and adding a binder into a cylindrical shape, as in the first embodiment. Yes.
In the present embodiment, the fuel electrode layer 204 is formed of two layers, a lower fuel electrode layer 204a and an upper fuel electrode layer 204b formed thereon. The lower fuel electrode layer 204a of these two layers is a conductive thin film composed of a mixture of NiO powder and 10YSZ (10 mol% Y ₂ O ₃ -90 mol% ZrO ₂ ) powder, as in the first embodiment. It is. On the other hand, the upper fuel electrode layer 204b is a conductive thin film composed of a mixture of NiO powder and GDC (10 mol% Gd ₂ O ₃ -90 mol% CeO ₂ ) powder.

  Here, the fuel electrode layer generally needs to have a catalytic function for reacting hydrogen and oxygen ions and a function for transporting charges (electrons) generated by the reaction. In the fuel cell 200 of the present embodiment, the lower fuel electrode layer 204a is made of a material having higher conductivity than the upper fuel electrode layer 204b, while the upper fuel electrode layer 204b is more catalytically active than the lower fuel electrode layer 204a. Made of high material. As a result, charges generated in the upper fuel electrode layer 204b immediately below the electrolyte layer 206 can be efficiently carried by the lower fuel electrode layer 204a, and a high-performance fuel electrode layer 204 can be configured.

In the present embodiment, the solid electrolyte layer 206 includes a lower electrolyte layer 206a and an upper electrolyte layer 206b formed thereon. Lower electrolyte layer 206a of these two layers, cerium complex oxide (LDC40. I.e., CeO ₂ of 40 mol% of La ₂ O ₃ -60mol%) is a thin film constituted by a powder or the like. On the other hand, the upper electrolyte layer 206b is a thin film made of LSGM powder having a composition of La _0.9 Sr _0.1 Ga _0.8 Mg _0.2 O ₃ , as in the first embodiment.

The lower electrolyte layer 206a functions as a reaction suppression layer, and a chemical reaction between the upper fuel electrode layer 204b and the upper electrolyte layer 206b is suppressed by the lower electrolyte layer 206a.
Similar to the electrolyte layer in the first embodiment, the upper electrolyte layer 206b generates electrical energy through the reaction between oxide ions and hydrogen or carbon monoxide.

In this embodiment, the air electrode layer 208 is composed of a lower air electrode layer 208a and an upper air electrode layer 208b formed thereon. Of these two layers, the lower air electrode layer 208a is a conductive thin film made of LSCF powder having a composition of La _0.6 Sr _0.4 Co _0.2 Fe _0.2 O ₃ . The upper air electrode layer 208b is a conductive thin film made of LSCF powder having a composition of La _0.6 Sr _0.4 Co _0.8 Fe _0.2 O ₃ .

  Here, the air electrode layer generally needs to have a catalytic function of ionizing oxygen in the air and a function of transporting electrons to be reacted with oxygen. In the fuel cell 200 of the present embodiment, the lower air electrode layer 208a is made of a material having higher catalytic activity than the upper air electrode layer 208b (a material having higher oxygen ion conversion performance), while the upper air electrode layer 208b is made lower It is made of a material having higher electron conductivity than the air electrode layer 208a. Thereby, oxygen can be efficiently ionized in the lower air electrode layer 208a adjacent to the electrolyte layer 206 by the electrons carried by the upper air electrode layer 208b, and the high-performance air electrode layer 208 is formed. be able to.

  Similarly to the first embodiment, the interconnector layer 210 includes a first interconnector layer 210a and a second interconnector layer 210b provided thereon.

A method for manufacturing a fuel cell according to the second embodiment of the present invention will be described.
Here, only the changes to the manufacturing process in the first embodiment described with reference to FIG. 9 will be described.
First, steps S1 to S3 in FIG. 9 are the same as those in the first embodiment.

  Next, in the first embodiment, after the fuel electrode layer is surface-formed by the surface film forming apparatus 130 in step S4 of FIG. 9, the deposited slurry is dried by a drying process. In the second embodiment, first, the lower fuel electrode layer 204a is formed by the surface film forming apparatus 130, dried by the drying process, and then the upper fuel electrode layer 204b is formed again by the surface film forming apparatus 130. dry. As a result, the lower fuel electrode layer 204a is formed on the porous support 202 where the masking layer is not formed, and the upper fuel electrode layer 204b is formed on the lower fuel electrode layer 204a.

  Here, the viscosity of the slurry used to form the lower fuel electrode layer 204a is higher than the viscosity of the slurry used to form the upper fuel electrode layer 204b. That is, excessive penetration of the slurry into the porous support 202 can be prevented by increasing the viscosity of the slurry for the lower fuel electrode layer 204a formed directly on the porous support 202. it can. Further, by reducing the viscosity of the slurry for the upper fuel electrode layer 204b, the deposited slurry can be easily spread, and the smoothness of the surface of the deposited upper fuel electrode layer 204b can be increased. The viscosity of the slurry can be appropriately set depending on the ratio of the powder of the material constituting the fuel electrode layer and the solvent in which it is suspended, the particle size of the suspended powder, the type of solvent to be suspended, and the like. .

  When the smoothness of the upper fuel electrode layer 204b is low and the layer thickness becomes nonuniform, the power generation reaction occurring in the fuel electrode layer becomes nonuniform in each part on the fuel electrode layer. When the power generation reaction becomes non-uniform, the current concentrates on the portion where the power generation reaction is strong, and the power generation operation in the fuel cell 200 becomes unstable. According to the present embodiment, such current concentration can be suppressed. Furthermore, by increasing the smoothness of the surface of the upper fuel electrode layer 204b, it is possible to prevent adverse effects on the smoothness of the electrolyte layer 206 and the air electrode layer 208 deposited on the upper fuel electrode layer 204b. it can.

Furthermore, steps S5 to S8 in FIG. 9 are the same as those in the first embodiment.
Next, in the first embodiment, in step S9 of FIG. 9, after the electrolyte layer is surface-formed by the surface film forming apparatus 130, the deposited slurry is dried by a drying process. In the second embodiment, first, the lower electrolyte layer 206a is formed by the surface film forming apparatus 130, dried by the drying process, and then the upper electrolyte layer 206b is formed again by the surface film forming apparatus 130 and dried. . As a result, the lower electrolyte layer 206a is formed on the first interconnector layer 210a where the masking layer is not formed, and the upper electrolyte layer 206b is formed on the lower electrolyte layer 206a.

Furthermore, steps S10 to S12 in FIG. 9 are the same as those in the first embodiment.
Next, in the first embodiment, after the air electrode layer is formed by the dot film forming apparatus 110 in step S13 of FIG. 9, the deposited slurry is dried by a drying process. In the second embodiment, first, the lower air electrode layer 208a is formed by the dot film forming apparatus 110, dried by the drying process, and then the upper air electrode layer 208b is formed again by the dot film forming apparatus 110, dry. Thereby, the lower air electrode layer 208a and the upper air electrode layer 208b are formed so as to cover a part of the second interconnector layer 210b and the upper electrolyte layer 206b.

Here, the viscosity of the slurry used to form the lower air electrode layer 208a is lower than the viscosity of the slurry used to form the upper air electrode layer 208b. That is, by lowering the viscosity of the slurry for the lower air electrode layer 208a, the droplets of the slurry sprayed by the jet dispenser 122 and adhered to the upper electrolyte layer 206b spread thinly, so that the dot traces hardly remain and are smooth. The lower air electrode layer 208a can be formed. On the other hand, by increasing the viscosity of the slurry for the upper air electrode layer 208b, the droplets of the slurry sprayed and adhered to the lower air electrode layer 208a do not spread so much, and the formed upper air electrode layer 208b becomes thicker. . As described above, by smoothly configuring the lower air electrode layer 208a having high catalytic activity, the catalytic reaction in the air electrode layer can be made uniform, and current concentration due to non-uniformity of the catalytic reaction can be suppressed. Can do. Further, since the upper air electrode layer 208b is formed thick, it is possible to reduce the electric resistance of the air electrode layer and to strengthen the upper air electrode layer 208b, which is the outermost functional layer that is most likely to be peeled off. it can.
Finally, the solid oxide fuel cell 200 of the present embodiment is completed by the second firing step of Step S14 in FIG. 9 similar to the first embodiment.

  According to the method for manufacturing the solid oxide fuel cell of the second embodiment of the present invention, the lower fuel electrode layer 204a formed on the porous support 202 is formed of a highly viscous slurry. The penetration of the slurry into the support 202 can be prevented, and a short circuit between the fuel electrode layers 204 can be reliably prevented. Further, since the upper fuel electrode layer 204b is formed from a slurry having low viscosity, the surface of the fuel electrode layer 204 can be formed more smoothly, and the adverse effect on the electrolyte layer 206 formed thereon is extremely reduced. be able to.

  Further, according to the method for manufacturing a solid oxide fuel cell of this embodiment, since the upper fuel electrode layer 204b is formed of a material having high catalytic activity, a power generation reaction is efficiently performed at the boundary with the electrolyte layer 206. In addition to being able to be generated, the lower fuel electrode layer 204a is formed of a highly conductive material, so that the charge generated by the power generation reaction can be transported with low loss.

  Furthermore, according to the manufacturing method of the solid oxide fuel cell of this embodiment, since the lower air electrode layer 208a is formed by accumulation of dots of low viscosity slurry, the surface of the lower air electrode layer 208a is compared. The oxygen ion permeability can be made uniform in each part. On the other hand, since the upper air electrode layer 208b is formed by accumulation of dots of highly viscous slurry, the upper air electrode layer 208b can be formed thick and the strength of the air electrode layer 208 can be increased. As a result, the air electrode layer 208 having stable performance and high strength can be formed.

  Further, according to the method for manufacturing the solid oxide fuel cell of the present embodiment, the lower air electrode layer 208a is formed relatively smoothly from a material having high catalytic activity, so that the air electrode layer 208 can be uniformly formed in each part. Oxygen ions can be generated, and a stable power generation reaction can be generated. Further, since the upper air electrode layer 208b is formed of a material having high conductivity (electron conductivity), electric charges can be transported to each part in the air electrode layer 208 with low loss.

As mentioned above, although preferable embodiment of this invention was described, a various change can be added to embodiment mentioned above. In particular, in the above-described embodiment, the surface film formation apparatus shown in FIG. 7 is used to contact the masked porous support by discharging the slurry from below to perform surface film formation. However, as a modification, the slurry can be contacted in various directions. For example, the slurry can be contacted by allowing the slurry to flow down from above the masked porous support. Moreover, a slurry can also be contacted by spraying a slurry on the porous support body which gave masking. Further, the slurry can be contacted by immersing the masked porous support in a tank containing the slurry.
Alternatively, a screen printing method can be employed as the surface film forming method. That is, surface deposition can be performed by depositing slurry on the porous support and applying the deposited slurry to a predetermined film thickness with a squeegee (not shown).

  Further, in the above-described embodiment, the porous support is cylindrical, but the present invention can be applied to various forms of solid oxide fuel cells such as an elliptical type and a flat type.

DESCRIPTION OF SYMBOLS 1 Solid oxide fuel cell system 2 Fuel cell module 4 Auxiliary machine unit 6 Housing 8 Fuel cell storage container 10 Power generation chamber 16 Fuel cell of embodiment of this invention (solid oxide fuel cell)
16a Power generation element 18 Exhaust gas collection chamber 20 Fuel gas supply flow path 21 Exhaust gas discharge flow path 22 Oxidant gas supply flow path 24 Water supply source 26 Pure water tank 28 Water flow rate adjustment unit 30 Fuel supply source 34 Heat exchanger 35 Electromagnetic valve 36 Desulfurizer 38 Fuel blower 40 Air supply source 45 Air flow rate adjustment unit 50 Hot water production device 54 Inverter 56 Oxidant gas introduction pipe 58 Exhaust gas discharge pipe 60 Combustion catalyst 61 Sheath heater 62 Ignition heater 63 First fixed member 64 Inner cylindrical member 64b Small hole 65 Intermediate cylindrical member 66 Outer cylindrical member 68 Inner cylindrical container 70 Outer cylindrical container 72 Dispersion chamber bottom member 72a Insertion pipe 74 Oxidant gas injection pipe 76 Fuel gas dispersion chamber 80 Bus bar 82 Current collector 86 Evaporating part 86a Inclined plate 88 Water Supply pipe 90 Fuel gas supply pipe 2 Fuel gas supply channel partition wall 92a injection port 94 reforming part 96 reforming catalyst 97 porous support 98 fuel electrode layer 100 electrolyte layer 101 air electrode layer 102 interconnector layer 102a first interconnector layer 102b second interconnector layer DESCRIPTION OF SYMBOLS 104 Masking layer 106 Masking layer 110 Dot film-forming apparatus 112 Base 114 Motor 116 Fixing jig 116a Tail stick 118 Head part 120 Guide rail 122 Jet dispenser 124 Slurry container 126 Camera 128 Nozzle part 128a Injection nozzle hole 128b Recessed part 128c Slurry supply passage 129 Injection actuator 129a Flexible plate 129b Projection part 130 Surface film forming apparatus 131 Base 132 Fixing jig 134 Motor 136 Surface film forming nozzle 138 Pump 139 Slurry container 200 Akira fuel cell of the second embodiment (solid oxide fuel cell)
200a Power generation element 202 Porous support 204 Fuel electrode layer 204a Lower fuel electrode layer 204b Upper fuel electrode layer 206 Electrolyte layer 206a Lower electrolyte layer 206b Upper electrolyte layer 208 Air electrode layer 208a Lower air electrode layer 208b Upper air electrode layer 210 Interconnector Layer 210a First interconnector layer 210b Second interconnector layer

Claims (8)

A method for producing a solid oxide fuel cell in which a plurality of power generation elements are formed on a porous support and these power generation elements are connected by an interconnector,
A support forming step for forming the porous support;
A fuel electrode layer forming step of forming a fuel electrode layer of the plurality of power generating elements by surface film formation simultaneously by attaching a slurry for forming a fuel electrode layer on the formed porous support;
The slurry for forming the interconnector is formed into droplets so as to be connected to the fuel electrode layer, and the dots of the slurry are formed by continuous ejection, and the interconnector is formed by accumulation of the dots. Interconnector forming process,
An electrolyte layer forming step of forming an electrolyte layer of the plurality of power generation elements on the fuel electrode layer;
On the electrolyte layer, slurry for forming the air electrode layer is formed into droplets and continuously ejected to form slurry dots, and the accumulation of the dots forms the air electrode layers of the plurality of power generating elements. Forming an air electrode layer,
A firing step of heating the porous support on which the fuel electrode layer, the electrolyte layer, and the air electrode layer are formed, and firing each layer;
A method for producing a solid oxide fuel cell, comprising:   2. The method for producing a solid oxide fuel cell according to claim 1, wherein the porous support is formed of an insulating material, and the plurality of fuel electrode layers formed on the porous support are insulated from each other. .   The fuel electrode layer is composed of a lower fuel electrode layer formed on the porous support and an upper fuel electrode layer formed on the lower fuel electrode layer, for forming the lower fuel electrode layer. The method for producing a solid oxide fuel cell according to claim 2, wherein the viscosity of the slurry is higher than the viscosity of the slurry for forming the upper fuel electrode layer.   The lower fuel electrode layer is formed of a material having higher conductivity than the upper fuel electrode layer, and the upper fuel electrode layer is formed of a material having higher catalytic activity than the lower fuel electrode layer. A method for producing a solid oxide fuel cell.   The air electrode layer includes a lower air electrode layer formed on the electrolyte layer and an upper air electrode layer formed on the lower air electrode layer, and a slurry for forming the lower air electrode layer. The method for producing a solid oxide fuel cell according to claim 4, wherein the viscosity of is lower than the viscosity of the slurry for forming the upper air electrode layer.   The lower air electrode layer is formed of a material having higher catalytic activity than the upper air electrode layer, and the upper air electrode layer is formed of a material having higher conductivity than the lower air electrode layer. A method for producing a solid oxide fuel cell. A manufacturing system for carrying out the method for manufacturing a solid oxide fuel cell according to any one of claims 1 to 6,
A fuel electrode layer forming device for forming a film of the fuel electrode layer by attaching a slurry for forming the fuel electrode layer;
An interconnector forming apparatus that forms dots on the interconnector by continuously spraying the slurry for forming the interconnector in the form of droplets;
An electrolyte layer forming device for forming the electrolyte layer on the fuel electrode layer;
An air electrode layer forming device that forms dots on the air electrode layer by continuously ejecting the slurry for forming the air electrode layer into droplets; and
A heating furnace for heating the porous support on which the fuel electrode layer, the electrolyte layer, and the air electrode layer are formed, and firing each layer;
A solid oxide fuel cell manufacturing system comprising:   The solid oxide fuel cell manufactured by the manufacturing method of the solid oxide fuel cell of any one of Claims 1 thru | or 6.