JP5178056B2 - Fuel cell structure, fuel cell, and electrode layer precursor green sheet - Google Patents

Description

  The present invention relates to a fuel cell structure, a fuel cell, and an electrode layer precursor green sheet.

  In recent years, environmental problems and energy problems have become major issues on a global scale, and fuel cells have attracted attention as a powerful power generation device that can contribute to solving them. Fuel cells are classified into solid oxide form, phosphoric acid form, molten carbonate form, polymer electrolyte form, etc., depending on the type of electrolyte constituting the fuel cell. Taking a solid oxide fuel cell as an example, the structure thereof will be described. A power generation cell having an air electrode layer on one side of a solid electrolyte layer made of an oxide ion conductor and a fuel electrode layer on the other side is provided as a separator. A stacked structure in which a plurality of layers are stacked via a gap (for example, Patent Document 1).

In the fuel cell configured as described above, for example, an oxidant gas (air, oxygen) is supplied from the oxidant gas supply port provided at the center of one side of the separator (the surface joined to the air electrode layer) to the air electrode layer. And supplying fuel gas (H ₂ , CO, CH _4, etc.) to the fuel electrode layer from the fuel gas supply port provided at the center of the other side of the separator (surface joined to the fuel electrode layer) Generate electricity. Oxygen supplied to the air electrode layer side passes through pores in the air electrode layer and reaches the vicinity of the interface with the solid electrolyte layer, and receives electrons from the air electrode layer at this portion to receive oxide ions (O ²⁻ ). Is ionized. The oxide ions diffuse and move in the solid electrolyte layer toward the fuel electrode layer, and the oxide ions that have reached the vicinity of the interface with the fuel electrode layer react with the fuel gas at this portion to react with the reaction product (H ₂ O, CO _2, etc.) are generated, and electrons are emitted to the fuel electrode layer. Electrons generated by the electrode reaction can be taken out as an electromotive force at an external load on another route.
JP 2006-086018 A

  However, in the fuel cell as described above, the concentration of the fuel gas supplied from the fuel gas supply port formed in the separator to the fuel electrode layer decreases as it goes from the central part of the fuel electrode layer to the outer edge part. Occurs. When the fuel gas concentration is uneven in the fuel electrode layer as described above, there is a problem that the battery reaction in the power generation cell is not performed uniformly and the power generation efficiency of the power generation cell is lowered. Further, the amount of heat generation is large in the region where the concentration of fuel gas is high, and the amount of heat generation is small in the region where the concentration of fuel gas is low, resulting in uneven temperature distribution in the power generation cell. As a result, thermal stress strain is generated in the fuel electrode layer, and the fuel electrode layer may be peeled off from the solid electrolyte layer and damaged.

  The present invention has been made to solve such problems, and uses a fuel cell structure capable of preventing the occurrence of non-uniform temperature distribution and increasing power generation efficiency. An object is to provide a fuel cell and an electrode layer precursor green sheet.

  The object of the present invention is a structure for a fuel cell comprising an electrolyte layer and one of an electrode layer of a fuel electrode layer or an air electrode layer formed in a film shape on one surface of the electrolyte layer, At least a part of the electrode layer is achieved by a fuel cell structure formed such that the reaction gas consumption rate changes along the film surface direction.

  In this fuel cell structure, it is preferable that at least a part of the electrode layer is formed so that the reaction gas consumption rate changes continuously or stepwise.

  Further, at least a part of the electrode layer is formed so that the reaction gas consumption rate changes stepwise, and a boundary portion where the reaction gas consumption rate changes is a groove where the surface of the electrolyte layer is exposed. It is preferable that it is provided.

  The electrode layer is formed of a mixture of a metal catalyst and an oxide ion conductor, and the reaction gas consumption rate is changed by changing the compounding ratio of the metal constituting the metal catalyst in the mixture. It is preferable to be formed.

  The electrode layer is preferably made of a metal oxide having a perovskite crystal structure, and is formed so that the reaction gas consumption rate is changed by changing the composition of the metal oxide. .

  The above-mentioned object of the present invention is achieved by a fuel cell comprising the above-described fuel cell structure.

  In this fuel cell, it is preferable that the fuel cell further includes a gas supply port that guides the reaction gas to the electrode layer, and is formed so that the reaction gas consumption rate of the electrode layer increases as the gas supply port moves away from the gas supply port. .

  Further, the above object of the present invention is an electrode layer precursor green sheet comprising any one of a fuel electrode layer and an air electrode layer formed in a film shape on one surface of a sheet-like base material, At least a part of the electrode layer is achieved by the electrode layer precursor green sheet formed so that the reaction gas consumption rate changes along the film surface direction.

  According to the present invention, there are provided a structure for a fuel cell capable of preventing generation of nonuniform temperature distribution and increasing power generation efficiency, a fuel cell using the same, and an electrode layer precursor green sheet. Can do.

  Hereinafter, a fuel cell according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side view showing a schematic configuration of a fuel cell according to an embodiment of the present invention. FIG. 2A is an enlarged cross-sectional view of the main part of the fuel cell shown in FIG. 1, and FIG. FIG. 3 is a plan view seen from an arrow A direction in FIG.

  As shown in FIGS. 1 and 2, a fuel cell 1 according to the present invention is a so-called flat plate type two-chamber solid oxide fuel cell, and includes a plurality of power generation cells 2. The fuel cell 1 has a stack structure in which a plurality of power generation cells 2 are stacked via separators 6, and currents generated by power generation reactions in each of the power generation cells 2 are serially connected in the stacking direction of the power generation cells 2. It is configured to flow.

  Each power generation cell 2 includes electrode layers 4 and 5 on both surfaces of a thin-film solid electrolyte layer 3 and is formed in a circular shape in plan view. The electrode layer provided on one surface of the solid electrolyte layer 3 is a fuel electrode layer 4 to which a fuel gas as a reaction gas is supplied, and the electrode layer provided on the other surface is an air to which an oxidant gas as a reaction gas is supplied. It is the polar layer 5. Here, the structure including the fuel electrode layer 4 on one surface of the solid electrolyte layer 3 is referred to as a fuel cell structure.

  As a material for forming the solid electrolyte layer 3, for example, a material having a fluorite type or perovskite type crystal structure that is widely known as an electrolyte material for a solid oxide fuel cell can be preferably used. Examples of those having a fluorite-type crystal structure include yttria stabilized zirconia (YSZ), scandia stabilized zirconia (ScSZ), samarium doped cerium oxide (SDC), gadolinium doped cerium oxide (GDC), and the like. Examples of those having a perovskite type crystal structure include lanthanum galide oxides doped with strontium and magnesium.

  The fuel electrode layer 4 is formed in a thin film shape having a circular shape in plan view, and fuel gas as a reaction gas supplied via a fuel gas supply port 62b of the separator 6 described later reaches the interface with the solid electrolyte layer 3. It is formed to be a porous layer so that it can be made. As a material for forming the fuel electrode layer 4, a mixture containing an oxide ion conductor such as a ceramic powder material and a metal catalyst can be used. As the oxide ion conductor, one having a fluorite-type or perovskite-type crystal structure can be preferably used. Examples of those having a fluorite-type crystal structure include SDC, GDC, ScSZ, and YSZ. Examples of those having a perovskite type crystal structure include lanthanum galide oxides doped with strontium and magnesium. As a metal constituting the metal catalyst, a material that is stable in a reducing atmosphere and has a hydrogen oxidation activity can be used. For example, nickel, iron, cobalt, or the like, or a noble metal (platinum, ruthenium, palladium, or the like) ) Etc. can be used. Among the above metals, nickel having high hydrogen oxidation activity is preferable. As a mixture containing a metal catalyst using nickel as a metal and an oxide ion conductor, for example, NiO / YSZ (YSZ: yttria stabilized zirconia) composite particles, NiO / SDC (SDC: samaria doped ceria) composite particles, Examples thereof include NiO / ScSz composite particles, NiO / YDC (YDC: yttria doped ceria) composite particles, and NiO / LSGM (LSGM: lanthanum strontium gallium magnesium oxide) composite particles.

  In addition, at least a part of the fuel electrode layer 4 is formed such that the consumption rate of the fuel gas, which is the reaction gas, changes along the film surface direction (in-plane direction). More specifically, as shown in FIG. 2, the fuel electrode layer 4 is concentrically divided into three regions 4a, 4b, and 4c from the center to the outer edge of the fuel electrode layer 4 in plan view. The regions 4a, 4b, and 4c are formed so that the consumption rates of the fuel gas that is the reaction gas are different. The fuel gas consumption rate in the central region 4a of the fuel electrode layer 4 is the lowest compared to the other regions 4b and 4c, and the fuel gas consumption rate in the outer edge region 4c of the fuel electrode layer 4 is lower than those in the other regions 4a and 4b. It is formed to be the highest. That is, the fuel electrode layer 4 is configured such that the fuel gas consumption rate increases stepwise from the center portion of the fuel electrode layer 4 toward the outer edge portion. Here, the fuel gas consumption rate is defined as the ratio between the flow rate of fuel gas consumed for power generation in an arbitrary region and the flow rate of fuel gas supplied to that region.

As described above, as a method of forming the fuel electrode layer 4 so that the fuel gas consumption rate changes along the film surface direction, an oxide ion conductor and a metal catalyst, which are materials for forming the fuel electrode layer 4, are used. The method of performing by changing the compounding ratio of the metal which comprises the metal catalyst contained in the mixture to contain is mentioned. For example, by changing the mixing ratio of Ni in each material such as the above-mentioned NiO / YSZ (YSZ: yttria stabilized zirconia) composite particles, NiO / SDC (SDC: samaria doped ceria) composite particles, the film The fuel electrode layer 4 can be formed so that the fuel gas consumption rate changes along the plane direction. By changing the mixing ratio of Ni, the electrode reaction in each of the regions 4a, 4b, and 4c can be increased or decreased. As a result, the flow rate of the fuel gas used for power generation in each of the regions 4a, 4b, 4c changes, and the fuel gas consumption rate can be changed. In the present embodiment, Ni—Ce _0.8 Sm _0.2 O ₂ composite particles that are NiO / SDC (SDC: samaria doped ceria) composite particles are employed as a material for forming the fuel electrode layer 4. In the region, the fuel gas consumption rate is changed by changing the volume ratio of Ni. In the central region 4a of the fuel electrode layer 4, it is preferable to adjust so that the volume ratio of Ni in the Ni—Ce _0.8 Sm _0.2 O ₂ composite particles is in the range of 30% to 45%. Moreover, in the outer edge part area | region 4c of the fuel electrode layer 4, it is preferable to adjust so that the same volume ratio may be in the range of 46%-65%. And in the area | region pinched | interposed by the center part area | region 4a and the outer edge part area | region 4c of the fuel electrode layer 4, it is preferable to adjust so that the same volume ratio may be in the range of 66%-80%.

The air electrode layer 5 is formed in a thin film shape having a circular shape in plan view, and an oxidant gas as a reaction gas supplied via an oxidant gas supply port 61b of the separator 6 described later is interfaced with the solid electrolyte layer 3. It is formed so that it may become a porous layer so that it can reach | attain. As a material for forming the air electrode layer 5, for example, metal oxide particles having a perovskite crystal structure can be used. Specifically, metal oxide particles such as LaMnO ₃ oxide, LaCoO ₃ oxide, and SmCoO ₃ oxide can be exemplified. One kind of the metal oxide particles described above may be used alone, or two or more kinds may be mixed and used. In addition, as a material for forming the air electrode layer 5, a noble metal such as platinum, ruthenium or palladium can be used.

  The power generation cell 2 including the fuel electrode layer 4 on one surface of the solid electrolyte layer 3 and the air electrode layer 5 on the other surface is, for example, between the electrode layer precursor green sheets that respectively form the fuel electrode layer 4 and the air electrode layer 5. In addition, the solid electrolyte layer precursor green sheet can be laminated, pressure-bonded and fired.

  The above various green sheets are, for example, mixed with materials for forming the fuel electrode layer 4, the air electrode layer 5, and the solid electrolyte layer 3, respectively, with an organic binder, a surfactant, a solvent, and the like to produce a paste-like material, It is manufactured by applying a predetermined thickness to one surface of a sheet-like base material by a screen printing method or a doctor blade method. In addition, the sheet-like base material in various green sheets is formed of a material made of hydrocarbon or carbon fiber such as urethane foam which can be removed by combustion at the time of firing. Here, when the electrode layer precursor green sheet for the fuel electrode layer 4 is manufactured, by using a known masking technique, a predetermined region of the fuel electrode layer 4 is separately coated with a material having a different fuel gas consumption rate, An electrode layer precursor green sheet for the fuel electrode layer 4 formed so that the fuel gas consumption rate changes along the film surface direction of the fuel electrode layer 4 can be manufactured.

The separator 6 is formed in a thin film shape having a circular shape in plan view as shown in FIG. 2 (b), and electrically connects the air electrode layer 5 and the fuel electrode layer 4 of the power generation cell 2 adjacent in the vertical direction. It is configured as follows. As shown in FIG. 2A, the separator 6 includes an oxidant gas channel 61 and a fuel gas channel 62 inside. One end of the oxidant gas flow path 61 constitutes an oxidant gas introduction port 61 a into which the oxidant gas is introduced, and is open to the side surface 6 a of the separator 6. The other end of the oxidant gas flow path 61 constitutes an oxidant gas supply port 61b for supplying oxidant gas to the air electrode layer 5, and one side of the separator 6 (surface joined to the air electrode layer 5). ) In the center. One end of the fuel gas flow path 62 constitutes a fuel gas inlet 62 a through which fuel gas is introduced, and is open to the side surface 6 a of the separator 6. The other end of the fuel gas flow path 62 constitutes a fuel gas supply port 62b for supplying fuel gas to the fuel electrode layer 4, and is the center of the other surface of the separator 6 (surface joined to the fuel electrode layer 4). Open to the part. With such a configuration, the separator 6 can supply an oxidant gas (air, oxygen) as a reaction gas to the air electrode layer 5 of the power generation cell 2 and also a fuel gas (H ₂ as a reaction gas) to the fuel electrode layer 4. , CO, CH _4, etc.).

Examples of a material for forming the separator 6 include conductive metals such as platinum, gold, silver, nickel, copper, and SUS, or metal-based materials, or La (Cr, Mg) O ₃ , (La, Ca) CrO _3. A conductive ceramic material such as lanthanum chromite such as (La, Sr) CrO ₃ can be used. One of these may be used alone, or two or more may be mixed and used.

The operation of the fuel cell 1 configured as described above will be described below. First, an oxidant gas (air, oxygen) is supplied to the air electrode layer 5 side through the oxidant gas supply port 61b of the separator 6, and a fuel gas (H) is supplied to the fuel electrode layer 4 side through the fuel gas supply port 62b. ₂ , CO, CH _4, etc.). Oxygen supplied to the air electrode layer 5 side passes through the pores in the air electrode layer 5 and reaches the vicinity of the interface with the solid electrolyte layer 3, and receives electrons from the air electrode layer 5 in this portion and receives oxide ions ( It is ionized to O ²⁻ ). The oxide ions diffuse and move in the solid electrolyte layer 3 toward the fuel electrode layer 4, and the oxide ions that have reached the vicinity of the interface with the fuel electrode layer 4 react with the fuel gas in this portion to produce a reaction product. (H ₂ O, CO _2, etc.) are generated, and electrons are emitted to the fuel electrode layer 4. The generated electrons are taken out as an electromotive force.

  In this manner, oxide ion conduction occurs between the fuel electrode layer 4 and the air electrode layer 5 through the solid electrolyte layer 3, and power generation is performed. Due to this power generation, Joule heat is generated by internal resistance or the like in the power generation cell 2, and this thermal energy is radiated to the outside.

  Here, the fuel electrode layer 4 in the fuel cell 1 according to the present invention is formed such that the fuel gas consumption rate increases stepwise along the film surface direction as the fuel electrode layer 4 moves away from the fuel gas supply port 62b. . Therefore, even if a phenomenon occurs in which the concentration of the fuel supplied from the fuel gas supply port 62b decreases from the fuel gas supply port 62b toward the outer edge of the fuel electrode layer 4, in the entire region of the fuel electrode layer 4, The fuel consumption can be made uniform, and the battery reaction in the power generation cell 2 can be made uniform. As a result, the power generation efficiency of the power generation cell 2 can be improved. In addition, since the battery reaction in the power generation cell 2 can be performed uniformly, the amount of heat generated in each of the regions 4a, 4b, and 4c can be substantially the same, and the temperature distribution in the power generation cell 2 is not uniform. It is possible to prevent the occurrence. Thereby, the situation where the fuel electrode layer 4 peels from the solid electrolyte layer 3 due to thermal stress strain can be effectively suppressed.

  As mentioned above, although one Embodiment of the fuel cell 1 which concerns on this invention was described, the specific structure of this invention is not limited to the said embodiment. For example, in the above-described embodiment, the fuel electrode layer 4 constituting the power generation cell 2 is configured so that the consumption rate of the fuel gas, which is the reaction gas, changes stepwise from the central part to the outer edge part of the fuel electrode layer 4. However, for example, the fuel gas consumption rate can be changed continuously from the central portion of the fuel electrode layer 4 toward the outer edge portion. Normally, the concentration of the fuel gas supplied from the fuel gas supply port 62b continuously decreases from the center of the fuel electrode layer 4 closest to the fuel gas supply port 62b toward the side edge of the fuel electrode layer 4. Therefore, by adopting such a configuration, the battery reaction in the power generation cell 2 is performed more uniformly, the power generation efficiency of the power generation cell 2 is improved, and the temperature distribution in the power generation cell 2 is not uniform. Can be prevented more reliably.

  Further, in the above-described embodiment, only the fuel electrode layer 4 is configured such that the consumption rate of the fuel gas, which is a reaction gas, changes in the film surface direction. In addition, the air electrode layer 5 can also be configured so that the consumption rate of the oxidant gas as the reaction gas changes in the film surface direction. Or only the air electrode layer 5 can also be comprised so that the consumption rate of the oxidizing gas which is a reactive gas may change to a film surface direction. In this case, the structure including the air electrode layer 5 on the other surface of the solid electrolyte layer 3 is a fuel cell structure. Here, the oxidant gas consumption rate is defined as a ratio between an oxidant gas flow rate consumed for power generation in an arbitrary region and an oxidant gas flow rate supplied to the region.

  As a method of configuring the air electrode layer 5 so that the consumption rate of the oxidant gas that is a reaction gas changes in the film surface direction, the composition of the material forming the air electrode layer 5 is changed along the film surface direction. A method can be illustrated. By changing the composition of the material forming the air electrode layer 5, the electrode reaction can be increased or decreased for each region having a different material composition. As a result, the flow rate of the oxidant gas used for power generation is changed for each region having a different material composition, and the oxidant gas consumption rate can be changed. For example, when a metal oxide having a perovskite crystal structure represented by the following chemical formula (1) is adopted as a material for forming the air electrode layer 5, x in the formula is changed to change A in the metal oxide. By changing the composition ratio of B and B, the consumption rate in the air electrode layer 5 of the oxidant gas as the reaction gas can be changed along the film surface direction.

A _1-x B _x MO ₃ chemical formula (1)
Here, A in the formula is La or Sm, B is one substance selected from Sr, Ca and Ba, and M is one substance selected from Co, Mn and Fe. . X is in the range of 0 <x ≦ 0.5.

  In addition, as shown in FIG. 3, in the fuel electrode layer 4, the boundary portion 4 d between the regions 4 a, 4 b, 4 c having different fuel gas consumption rates is configured to include a groove 7 in which the solid electrolyte layer 3 is exposed. You can also. As described above, the boundary portion 4d where the fuel gas consumption rate of the fuel electrode layer 4 changes has the groove 7, so that due to the difference in the material forming the regions 4a, 4b, 4c of the fuel electrode layer 4, Even if there is a difference in the amount of thermal elongation between the regions 4a, 4b, and 4c, it is effective that the groove absorbs the difference in the amount of thermal elongation and damages such as cracks and peeling occur in the boundary portion 4d. It becomes possible to prevent.

  Further, as shown in FIG. 4, the fuel electrode layer 4 has a multi-layer structure 4A, 4B, and the consumption rate of the fuel gas, which is a reaction gas, is changed toward the film surface direction in each layer 4A, 4B. You can also. With such a configuration, the amount of fuel consumed in the fuel electrode layer 4 can be made uniform with high accuracy throughout the fuel electrode layer 4, and non-uniform temperature distribution in the power generation cell 2 can be prevented. However, the power generation efficiency of the power generation cell 2 can be improved.

  Moreover, in the said embodiment, what is called a two-chamber type fuel cell 1 is employ | adopted, For example, the single-chamber type fuel cell 1 is also employable. When the single-chamber fuel cell 1 is employed, an enlarged cross-sectional view of the main part of FIG. 5A and a plan view of the fuel electrode layer 4 viewed from the direction indicated by the arrow B (FIG. 5B) As shown by D, the mixed gas of the fuel gas and the oxidant gas as the reaction gas is supplied to the power generation cell 2 from the outside in the radial direction of the power generation cell 2. In such a case, the fuel gas consumption rate of the fuel electrode layer 4 increases in the order of the outer edge region 4c of the fuel electrode layer 4, the region 4b sandwiched between the outer edge region 4c and the central region 4a, and the central region 4a. The fuel electrode layer 4 may be configured as described above. In the case of the fuel cell 1 as shown in FIG. 5, the side surface 4h of the fuel electrode layer 4 constitutes the fuel gas supply port 62b.

  Further, depending on how the fuel cell 1 is used, local temperature distribution may be uneven at various positions. In such a case, nonuniform temperature distribution occurs by forming the fuel electrode layer 4 by changing the fuel gas consumption rate in the local portion of the fuel electrode layer 4 where the temperature distribution is uneven. Can be prevented. For example, a steam generator or reformer used for steam reforming the fuel gas may be provided in the vicinity of the fuel cell 1 separately. The temperature of the outer edge region 4 c may be higher than the temperature of the region sandwiched between the outer edge region 4 c and the central region 4 a of the fuel electrode layer 4. In such a case, the fuel gas consumption rate in the outer edge region 4c of the fuel electrode layer 4 is lower than the fuel gas consumption rate in the region sandwiched between the central region 4a and the outer edge region 4c of the fuel electrode layer 4. By setting, it is possible to reduce the temperature of the outer edge region 4c and suppress the occurrence of non-uniform temperature distribution.

  Moreover, in the said embodiment, the separator 6 has the fuel gas flow path 62 inside, and the fuel gas supply formed in the center part of the other side (surface joined to the fuel electrode layer 4) of the said separator 6 Although it is configured to discharge the fuel gas to the central portion of the fuel electrode layer 4 through the port 62b, it is not particularly limited to such a configuration. For example, as shown in the enlarged cross-sectional view of the main part of FIG. 6A, the fuel gas supply port 62b is provided at the outer edge of the other surface of the separator 6 so that the fuel gas is discharged to the outer edge of the fuel electrode layer 4. It can also be formed. In the case of such a configuration, as shown in FIG. 6 (b) which is a plan view of the fuel electrode layer 4 viewed from the direction of arrow C in FIG. 6 (a), the fuel electrode layer 4 is divided into a plurality of belt-like regions 4e, The fuel electrode layer 4 is formed so that the fuel gas consumption rate in each region increases as the distance from the fuel gas supply port 62b increases.

  In the present embodiment, the fuel cell 1 is a flat plate fuel cell 1, but is not particularly limited to such a form, and may be, for example, a cylindrical fuel cell 1. Further, the fuel electrode layer 4, the solid electrolyte layer 3, the air electrode layer 5, and the separator 6 have a circular shape in plan view, but are not particularly limited thereto. It can be made into a shape.

  In this embodiment, a solid electrolyte fuel cell is adopted as the fuel cell 1, but various fuel cells such as phosphoric acid type, molten carbonate type, and polymer electrolyte type are adopted. Is possible.

1 is a side view showing a schematic configuration of a fuel cell according to an embodiment of the present invention. (A) is a principal part expanded sectional view of the fuel cell shown in FIG. 1, (b) is a top view of the fuel electrode layer seen from the arrow A direction. FIG. 6 is an enlarged cross-sectional view of a main part showing a modification of the fuel cell shown in FIG. 1. FIG. 6 is an enlarged cross-sectional view of a main part showing a modification of the fuel cell shown in FIG. 1. (A) is a principal part expanded sectional view which shows the modification of the fuel cell shown in FIG. 1, (b) is a top view of the fuel electrode layer seen from the arrow B direction. (A) is a principal part expanded sectional view which shows the modification of the fuel cell shown in FIG. 1, (b) is a top view of the fuel electrode layer seen from the arrow C direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Power generation cell 3 Solid electrolyte layer 4 Fuel electrode layer (electrode layer)
5 Air electrode layer (electrode layer)
6 Separator 61 Oxidant gas channel 61a Oxidant gas inlet 61b Oxidant gas supply port 62 Fuel gas channel 62a Fuel gas inlet 62b Fuel gas supply port 7 Groove

Claims (4)

A fuel cell structure comprising: an electrolyte layer; and one electrode layer of a fuel electrode layer or an air electrode layer formed in a film shape on one surface of the electrolyte layer,
The electrode layer is formed from a mixture of a metal catalyst and an oxide ion conductor,
At least a portion of the electrode layer, by changing the mixing ratio of the metal constituting the metal catalyst in the mixture, is formed so that stepwise reaction gas consumption rate varies along the membrane surface direction ,
The boundary part where the reaction gas consumption rate changes is a fuel cell structure including a groove in which the surface of the electrolyte layer is exposed . A fuel cell comprising the fuel cell structure according to claim 1 . A gas supply port for introducing a reaction gas to the electrode layer;
The follow away from the gas supply port, the fuel cell according to claim 2 which the reaction gas consumption rate of the electrode layer is formed to be higher. An electrode layer precursor green sheet comprising an electrode layer of either a fuel electrode layer or an air electrode layer formed in a film shape on one surface of a sheet-like substrate,
The electrode layer is formed from a mixture of a metal catalyst and an oxide ion conductor,
At least a part of the electrode layer is formed such that the reaction gas consumption rate changes stepwise along the film surface direction by changing the compounding ratio of the metal constituting the metal catalyst in the mixture. ,
The boundary part where the reaction gas consumption rate changes is an electrode layer precursor green sheet provided with a groove in which the surface of the electrolyte layer is exposed .

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