JP2015159080A - Cell, cell stack device, module and module housing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolytic cell, a cell stack device, an electrolytic module and an electrolytic device, capable of inhibiting cracks from being generated.SOLUTION: An electrolytic cell includes: a porous conductive support body 1 having a long shape; an insulating dense cylindrical body 9 which is provided on the side surface of the support body 1 so as to surround the support body 1 and has a first opening 9a in a portion located on the side surface of the support body 1; and a first porous electrode layer 3, a dense solid electrolyte layer 4 and a second porous electrode layer 6, which are provided in the support body 1 in the first opening 9a of the cylindrical body 9. The outer peripheral part of the solid electrolyte layer 4 is joined to the cylindrical body 9.

Description

  The present invention relates to an electrolytic cell, a cell stack device, an electrolytic module, and an electrolytic device.

  In recent years, various fuel cell devices have been proposed in which a cell stack device formed by electrically connecting a plurality of solid oxide fuel cells in series is accommodated in a storage container as next-generation energy.

  As such a solid oxide fuel cell of the fuel cell device, for example, it has a pair of parallel flat surfaces, a fuel gas passage for allowing fuel gas to flow inside, and contains Ni What comprises the electroconductive support body formed by doing is known (for example, refer patent document 1). In Patent Document 1, a fuel electrode layer, a solid electrolyte layer, and an oxygen electrode layer are sequentially stacked on a flat surface on one side of a conductive support, and an interconnector layer is stacked on a flat surface on the other side. .

The solid oxide fuel cell includes a solid electrolyte layer formed of a dense ZrO ₂ oxide formed so as to surround the periphery of the conductive support, and a dense electrolyte at both ends of the solid electrolyte layer. The interconnector layer made of LaCrO ₃ oxide is joined so that both ends overlap each other, and the solid electrolyte layer and the interconnector layer surround the conductive support in an airtight manner, thereby supporting the conductive support. The fuel gas passing through the inside of the body is configured not to leak to the outside from the dense cylindrical body formed by the solid electrolyte layer and the interconnector layer.

JP 2008-84716 A

  In recent years, the ionic conductivity improves as the thickness of the solid electrolyte layer decreases, and the power generation performance of the fuel cell improves. Therefore, the thickness of the solid electrolyte layer is reduced in order to improve the power generation performance. However, if the thickness of the solid electrolyte layer is reduced in order to improve the power generation performance, the strength improvement effect by the solid electrolyte layer is lowered, and there is a possibility that cracks are likely to occur in the fuel cell.

  An object of the present invention is to provide an electrolytic cell, a cell stack device, an electrolytic module, and an electrolytic device that can suppress the occurrence of cracks.

  The electrolysis cell of the present invention is a long and porous conductive support, and is provided on the side surface of the support so as to surround the support, and is first in a portion located on the side of the support. An insulating dense cylindrical body having an opening, and a porous first electrode layer, a dense solid electrolyte layer, and a porous body provided on the support in the first opening of the cylindrical body And a second electrode layer, and an outer peripheral portion of the solid electrolyte layer is joined to the cylindrical body.

The electrolytic cell of the present invention is provided with a long porous conductive support serving as the first electrode layer, and provided on the side surface of the support so as to surround the support. An insulating dense cylindrical body having a first opening in a portion located on a side surface, and a dense solid electrolyte layer and a porous body provided on the support in the opening of the cylindrical body And a second electrode layer, and an outer peripheral portion of the solid electrolyte layer is bonded to the cylindrical body.

  The cell stack device of the present invention comprises a plurality of the above-described electrolysis cells, and is formed by electrically connecting the plurality of electrolysis cells.

  The electrolytic module of the present invention is characterized in that the cell stack device is stored in a storage container.

  The electrolysis apparatus of the present invention is characterized in that the above-described electrolysis module and an auxiliary machine for operating the electrolysis module are housed in an outer case.

  In the electrolytic cell of the present invention, the first opening of the cylindrical body may be closed with a solid electrolyte layer to form a cylindrical sealing layer with the cylindrical body and the solid electrolyte layer, and the inside may be used as a gas passage. While it is possible to improve the electrolytic performance by reducing the thickness of the solid electrolyte layer, the strength of the cylindrical body can be increased by, for example, forming the cylindrical body with a high-strength material or increasing the thickness of the cylindrical body. And the generation of cracks in the electrolytic cell can be suppressed.

  Thereby, a cell stack device, an electrolysis module, and an electrolysis device with high performance and high long-term reliability can be provided.

1 shows a fuel cell, where (a) is a side view seen from the interconnector layer side, and (b) is a side view seen from the oxygen electrode layer side. FIG. 2A is a cross-sectional view taken along line 2a-2a in FIG. 1A, and FIG. 2B is a cross-sectional view taken along line 2b-2b in FIG. (A) is sectional drawing which shows the state which provided the solid electrolyte layer of the electric power generation element part in the opening part of a cylindrical body, (b) is the cylindrical body superimposed on the outer peripheral part of the solid electrolyte layer of an electric power generation element part. It is sectional drawing which shows a state. It is sectional drawing which shows the state in which the outer peripheral part of the solid electrolyte layer of an electric power generation element part has overlapped with the outer peripheral surface of the 1st opening part of a cylindrical body. The fuel cell of the form by which the interconnector layer is not provided in the upper end part is shown, (a) is the side view seen from the interconnector layer side, (b) is the side view seen from the oxygen electrode layer side. . It is explanatory drawing which shows the manufacturing method of the fuel battery cell of FIG. The cell stack apparatus is shown, (a) is a side view, (b) is an enlarged cross-sectional view showing a part of (a). 1 shows a state in which the fuel battery cell of FIG. 1 is bonded and fixed to a gas tank using an adhesive, wherein (a) is a side view seen from the cell arrangement direction, and (b) is a side view seen from the cell width direction ( (Partial cross section). It is an external appearance perspective view which shows an example of a fuel cell module. It is a perspective view which abbreviate | omits and shows a part of fuel cell apparatus.

  1 and 2 show a fuel cell as an example of an electrolysis cell. FIGS. 1A and 1B are side views as seen from the interconnector layer and oxygen electrode layer side, respectively. ) Is a cross-sectional view taken along line 2a-2a in FIG. 1A, and FIG. 2B is a cross-sectional view taken along line 2b-2b. In both drawings, a part of each component of the fuel cell 10 is shown enlarged.

  As shown in FIG. 2, this fuel cell 10 is a hollow flat plate type, has a flat cross section, and has a long and porous conductive structure containing Ni having an elliptical columnar shape as a whole. A support 1 is provided. As shown in FIG. 2, the support 1 has a pair of flat surfaces n on the upper and lower surfaces, and has a pair of arcuate surfaces m that are provided in the cell width direction W and connect the pair of flat surfaces n. Yes. Inside the support 1, a plurality of fuel gas passages 2 are formed at appropriate intervals so as to penetrate in the length direction L of the fuel cell 10, and the fuel cell 10 is formed on the support 1 in various ways. It has the structure where the member of this was provided.

  And in this embodiment, the insulating dense cylindrical body 9 is provided on the side surface of the support body 1 so as to surround the support body 1, and the side surface of the support body 1 of this cylindrical body 9 is provided. Two first openings 9a and second openings 9b are formed in the position. In addition, as shown to Fig.1 (a), the recessed part formed in the upper end of the cylindrical body 9 like the 2nd opening part 9b is also defined as an opening part in this embodiment.

  The first opening 9 a is provided at the center of the cylindrical body 9 in the cell length direction L, is not provided at both ends of the cell length direction, and the second opening 9 b is formed on the cylindrical body 9. Although formed downward from the upper end of the cell length direction L, it is not provided at the lower end of the cell length direction L.

  A porous fuel electrode layer (first electrode layer) 3, a dense solid electrolyte layer 4, and a porous material are provided on the side surface (first side surface) of the support 1 in the first opening 9 a of the cylindrical body 9. An oxygen electrode layer (second electrode layer) 6 is provided, and a portion of the side surface (second side surface) of the support 1 in the second opening 9b of the cylindrical body 9 is formed of a dense conductive ceramic. A connector layer 8 is provided. In addition, the side surface of the support body 1 means a pair of flat surfaces n and a pair of arcuate surfaces m.

  That is, the cylindrical body 9 is formed so as to cover the pair of flat surfaces n and the pair of arcuate surfaces m, and the cylindrical body 9 on the one flat surface n has a rectangular first opening 9a. The cylindrical body 9 on the other flat surface n is provided with a rectangular second opening 9b.

  In the first opening 9a, as shown in FIGS. 2A and 3A, the fuel electrode layer (first electrode layer) 3, the solid electrolyte layer 4, and the oxygen electrode layer (second electrode layer) 6 are provided. These are formed in a rectangular shape, and the outer periphery of the solid electrolyte layer 4 is joined to the wall surface forming the first opening 9 a of the cylindrical body 9.

  In addition, a rectangular interconnector layer 8 is provided in the second opening 9b, and the outer peripheral portion of the interconnector layer 8 is joined to the wall surface and the upper surface of the wall portion constituting the first opening 9a of the cylindrical body 9. doing. The interconnector layer 8 is not formed at the lower end portion in the cell length direction L, and a cylindrical body is formed on the entire outer peripheral surface of the support 1 as shown in FIG.

  The cylindrical body 9 covers the pair of flat surfaces n and the arcuate surfaces m on both sides of the support 1 except for the portion of the support 1 where the solid electrolyte layer 4 and the interconnector layer 8 are provided. The thickness of the solid electrolyte layer 4 is preferably 30 μm or less, particularly 20 μm or less, and more preferably 15 μm or less from the viewpoint of improving power generation performance. The interconnector layer 8 also has a thickness of 70 μm or less, particularly 50 μm or less, because the thinner the interconnector layer 8, the better the conductivity.

  A porous oxygen electrode layer 6 is disposed on the surface of the solid electrolyte layer 4 so as to face the fuel electrode layer 3 via the intermediate layer 5. The intermediate layer 5 is formed on the solid electrolyte layer 4 on which the oxygen electrode layer 6 is formed. The oxygen electrode layer 6 is formed on the upper surface of the intermediate layer 5 and the upper surface of the wall portion constituting the first opening 9a.

Here, in the fuel cell 10, the portion where the fuel electrode layer 3 and the oxygen electrode layer 6 face each other through the solid electrolyte layer 4 functions as a fuel cell to generate electric power. That is, an oxygen-containing gas such as air is allowed to flow outside the oxygen electrode layer 6, and a fuel gas (hydrogen-containing gas) is allowed to flow in the fuel gas passage 2 in the support 1 to generate power by heating to a predetermined operating temperature. . The current generated by such power generation is collected via the interconnector layer 8 provided on the support 1.

  That is, the dense cylindrical body 9 having gas barrier properties, the solid electrolyte layer 4 and the interconnector layer 8 surround the support 1 so that fuel gas flowing through the inside does not leak to the outside. In other words, the cylindrical body 9, the solid electrolyte layer 4 and the interconnector layer 8 form an elliptic cylindrical body having a gas barrier property, and the inside of the elliptic cylindrical body serves as a fuel gas flow path. The fuel gas supplied to the layer 3 and the oxygen-containing gas supplied to the oxygen electrode layer 6 are blocked by an elliptic cylinder. The dense cylindrical body 9, the solid electrolyte layer 4 and the interconnector layer 8 have a porosity of 5% or less, particularly 2% or less, as measured by a scanning electron micrograph using an image analyzer. The solid electrolyte layer 4 and the interconnector layer 8 are referred to.

The cylindrical body 9 may be a dense and high-strength material, but it is particularly desirable that the cylindrical body 9 be made of a solid electrolyte material. As the solid electrolyte material, a material constituting the solid electrolyte layer 4, for example, a zirconia-based oxide, a lanthanum galide-based oxide, or the like can be used. In particular, the same material as the solid electrolyte layer 4 is desirable. The solid electrolyte layer 4 and the cylindrical body 9 are preferably composed of ZrO ₂ containing a rare earth element. In this case, the cylindrical body 9 should have a rare earth element content less than the solid electrolyte layer 4. Is desirable from the viewpoint of improving the strength.

In particular, the solid electrolyte layer 4 is composed of partially stabilized zirconia, for example, ZrO ₂ in which ₃ to 15 mol%, particularly 7 to 9 mol% of Y ₂ O ₃ is dissolved, which improves power generation performance. Is desirable. The solid electrolyte material constituting the cylindrical body 9 is preferably the same partially stabilized zirconia and contains the same rare earth element as the solid electrolyte layer 4. Furthermore, it is desirable from the viewpoint of strength that the rare earth element is less than the solid electrolyte layer 4 and is made of, for example, ZrO ₂ in which ₃ to 5 mol% of Y ₂ O ₃ is dissolved.

  In the fuel cell 10 as described above, since the porous support 1 is surrounded by the dense seal body constituted by the cylindrical body 9, the solid electrolyte layer 4 and the interconnector layer 8, the cylindrical body 9 The interior can be a gas passage. Moreover, since the cylindrical body 9 exists in the portion where the solid electrolyte layer 4 and the interconnector layer 8 are not formed, the thickness of the solid electrolyte layer 4 and the interconnector layer 8 is reduced to improve the power generation performance. On the other hand, the cylindrical body 9 can be reinforced by increasing the thickness, or can be made of a high-strength material. In particular, the arcuate surface m of the support 1 or both ends of the support 1 in the cell length direction It is possible to suppress the occurrence of cracks in the part.

Conventionally, the interconnector layer 8 made of LaCrO ₃ -based oxide expands when exposed to a reducing atmosphere, and the porous conductive support 1 containing Ni is formed from the interconnector layer 8. Due to the elemental diffusion, it tends to expand when exposed to a reducing atmosphere. When the lower end of the fuel cell 10 is joined to the opening of the gas tank with an adhesive made of an inorganic material as shown in FIG. 8 to be described later, an interconnector is provided in a portion where the adhesive of the fuel cell 10 does not exist. While the layer 8 is intended to be reduced and expanded by being exposed to a reducing atmosphere, the adhesive layer suppresses the reduction and expansion of the interconnector layer 8 at the bonding portion of the fuel cell 10 with the adhesive. There was a risk that cracks would occur due to large stress at the lower end.

On the other hand, in this embodiment, the interconnector layer 8 that is reduced and deformed is not formed at the lower end portion of the support 1 in the cell length direction L, and the cylindrical body 9 is formed. The lower end portion of the cylindrical body 9 can be joined with an adhesive, and the interconnector layer 8 portion can be structured not to be joined with an adhesive, whereby the stress at the lower end portion of the cell can be reduced and cracking can be suppressed. .

  1 and 2, the case where the outer peripheral surface of the solid electrolyte layer 4 is joined to the wall surface forming the first opening 9a of the cylindrical body 9 as shown in FIG. However, as shown in FIG. 3B, the outer peripheral surface of the solid electrolyte layer 4 (intermediate layer 5) is overlapped with the outer peripheral portion constituting the first opening 9 a of the cylindrical body 9 via the intermediate layer 5. And the case where the outer peripheral surface of the solid electrolyte layer 4 joins to the wall surface which comprises the 1st opening part 9a may be sufficient. Furthermore, as shown in FIG. 4, the outer peripheral portion of the solid electrolyte layer 4 may be superposed on and bonded to the outer peripheral surface of the first opening 9 a of the cylindrical body 9.

  FIG. 5 shows another form of the fuel cell 10. In this form, the second opening 9 b provided with the interconnector layer 8 is cylindrical at both ends of the support 1 in the cell length direction L. It is provided in a state where a part of the body 9 exists. In this embodiment, since the interconnector layer 8 is not formed at both ends in the cell length direction L of the support 1, stress at both ends of the cell due to reduction expansion of the interconnector layer 8 can be reduced.

  Below, each member which comprises the fuel cell 10 of this embodiment is demonstrated.

  The conductive support 1 is required to be gas permeable in order to allow fuel gas to permeate to the fuel electrode layer 3 and to be conductive in order to collect current via the interconnector layer 8. From, for example, it is preferable to form Ni and / or NiO and an inorganic oxide such as a specific rare earth oxide.

The specific rare earth oxide is used to make the thermal expansion coefficient of the support 1 close to the thermal expansion coefficient of the solid electrolyte layer 4, and is Y, Lu, Yb, Tm, Er, Ho, Dy, Gd. Rare earth oxides containing at least one element selected from the group consisting of Sm, Pr can be used in combination with Ni and / or NiO. Specific examples of such rare earth oxides include Y ₂ O ₃ , Lu ₂ O ₃ , Yb ₂ O ₃ , Tm ₂ O ₃ , Er ₂ O ₃ , Ho ₂ O ₃ , Dy ₂ O ₃ , Gd ₂ O. ₃ , Sm ₂ O ₃ , Pr ₂ O ₃ can be exemplified, there is almost no solid solution and reaction with Ni and / or NiO, the thermal expansion coefficient is the same as that of the solid electrolyte layer 4, and From the point of being cheap, Y ₂ O ₃ and Yb ₂ O ₃ are preferable.

  In the present embodiment, Ni and / or NiO: rare earth oxide = 35: 65 in that the good conductivity of the support 1 is maintained and the thermal expansion coefficient is approximated to that of the solid electrolyte layer 4. It is preferably present in a volume ratio of 65:35. The support 1 may contain other metal components and oxide components as long as required characteristics are not impaired.

  Further, since the support 1 is required to have fuel gas permeability, it is porous and usually has an open porosity of 30% or more, particularly 35 to 50%. . Further, the conductivity of the support 1 is preferably 300 S / cm or more, and particularly preferably 440 S / cm or more.

  Note that the length of the flat surface n of the support 1 (the length of the support 1 in the cell width direction W) is, for example, 15 to 35 mm, and the length of the arcuate surface m (the length of the arc) is 2 to 8 mm. The thickness of the support 1 (thickness between the flat surfaces n) is 1.5 to 5 mm. The length of the support 1 is, for example, 100 to 300 mm.

The fuel electrode layer 3 causes an electrode reaction, and can be formed of a well-known porous conductive ceramic. For example, it can be formed from ZrO _{2 in which a} rare earth element oxide is dissolved or CeO _{2 in} which a rare earth element oxide is dissolved, and Ni and / or NiO. As the rare earth element, the rare earth elements exemplified in the conductive support 1 can be used. For example, the rare earth element can be formed from ZrO ₂ (YSZ) in which Y ₂ O ₃ is dissolved and Ni and / or NiO. .

The content of ZrO ₂ in which the rare earth element oxide is dissolved in the fuel electrode layer 3 or CeO ₂ in which the rare earth element oxide is dissolved is preferably in the range of 35 to 65% by volume, and Ni or The content of NiO is preferably 65 to 35% by volume. Further, the open porosity of the fuel electrode layer 3 is preferably 15% or more, particularly preferably in the range of 20 to 40%, and the thickness thereof is preferably 1 to 30 μm.

The solid electrolyte layer 4 is preferably made of a ceramic made of partially stabilized or stabilized ZrO ₂ containing 3 to 15 mol% of a rare earth element such as Y, Sc, or Yb. As the rare earth element, Y is preferable because it is inexpensive. The solid electrolyte layer 4 is not limited to ceramics made of partially stabilized or stabilized ZrO _2, and may of course be a conventionally known, for example, lanthanum galade based solid electrolyte layer. .

  The solid electrolyte layer 4 and the oxygen electrode layer 6 are strongly bonded to each other between the solid electrolyte layer 4 and the oxygen electrode layer 6 described later, and the components of the solid electrolyte layer 4 react with the components of the oxygen electrode layer 6. Thus, the intermediate layer 5 is formed for the purpose of suppressing the formation of a reaction layer having a high electrical resistance.

The intermediate layer 5 is made of a CeO ₂ based sintered body containing a rare earth element other than Ce. For example, (CeO ₂ ) _1-x (REO _1.5 ) _x (where RE is Sm , Y, Yb, and Gd, and x preferably has a composition represented by the following formula: 0 <x ≦ 0.3. Furthermore, from the viewpoint of reducing electrical resistance, it is preferable to use Sm or Gd as RE, for example, it is preferably made of CeO ₂ in which 10 to 20 mol% of SmO _1.5 or GdO _1.5 is dissolved. .

The oxygen electrode layer 6 is preferably formed of a conductive ceramic made of a so-called ABO ₃ type perovskite oxide. Such perovskite oxides include La-containing transition metal perovskite oxides, particularly at least one of LaMnO ₃ oxides, LaFeO ₃ oxides, and LaCoO ₃ oxides in which Sr and La coexist at the A site. LaCoO ₃ oxides are particularly preferable from the viewpoint of high electrical conductivity at an operating temperature of about 600 to 1000 ° C. In the perovskite oxide, Fe and Mn may exist together with Co at the B site.

  Further, the oxygen electrode layer 6 needs to have gas permeability. Therefore, the conductive ceramic (perovskite oxide) forming the oxygen electrode layer 6 has an open porosity of 20% or more, particularly 30 to 50%. It is preferable that it exists in the range. Furthermore, the thickness of the oxygen electrode layer 6 is preferably 30 to 100 μm from the viewpoint of current collection.

The interconnector layer 8 is made of conductive ceramics. In order to come into contact with fuel gas (hydrogen-containing gas) and oxygen-containing gas, it is necessary to have reduction resistance and oxidation resistance. For this reason, for example, lanthanum chromite-based perovskite oxides (LaCrO ₃ -based oxides) are used as conductive ceramics having reduction resistance and oxidation resistance, and particularly the heat of the support 1 and the solid electrolyte layer 4. For the purpose of approaching the expansion coefficient, a LaCrMgO ₃ -based oxide in which Mg is present at the B site is used. The interconnector layer 8 material may be conductive ceramics and is not particularly limited.

The thickness of the interconnector layer 8 is 1 in terms of preventing gas leakage and electric resistance.
It is preferable that it is 0-70 micrometers. Within this range, gas leakage can be prevented and electrical resistance can be reduced.

  Further, an adhesion layer (not shown) is formed between the support 1 and the interconnector layer 8 in order to reduce the difference in thermal expansion coefficient between the interconnector layer 8 and the support 1. Can do.

Such an adhesion layer may have a composition similar to that of the fuel electrode layer 3. For example, it can be formed from at least one of rare earth oxide, ZrO _{2 in which} a rare earth element oxide is dissolved, and CeO ₂ in which a rare earth element oxide is dissolved, and Ni and / or NiO. More specifically, for example, a composition composed of Y ₂ O ₃ and Ni and / or NiO, a composition composed of ZrO ₂ (YSZ) in which Y ₂ O ₃ is dissolved, and Ni and / or NiO, Y, Sm, Gd It can be formed from a composition composed of CeO ₂ and Ni and / or NiO in which an oxide such as oxide is dissolved. Note that the volume ratio of ZrO ₂ (CeO ₂ ) in which the rare earth oxide or rare earth element oxide is dissolved and Ni and / or NiO is preferably in the range of 40:60 to 60:40.

  An example of a method for producing the fuel battery cell 10 of the present embodiment described above will be described.

First, for example, Ni and / or NiO powder, a rare earth oxide powder such as Y ₂ O ₃ , an organic binder, and a solvent are mixed to prepare a clay, and this clay is used for extrusion molding. As shown in FIG. 6 (a), a support molded body is prepared and dried. In addition, you may use the calcined body which calcined the support body molded object at 900-1000 degreeC for 2 to 6 hours as a support body molded object.

Next, for example, according to a predetermined composition, raw materials of NiO and ZrO ₂ (YSZ) in which Y ₂ O ₃ is dissolved are weighed and mixed. Thereafter, an organic binder and a solvent are mixed with the mixed powder to prepare a slurry for the fuel electrode layer.

Further, for example, CeO ₂ powder in which GdO _1.5 is dissolved is heat-treated at 800 to 900 ° C. for 2 to 6 hours to adjust the raw material powder for the intermediate layer molded body. Toluene is added as a solvent to this raw material powder to prepare an intermediate layer slurry.

Then, a solid electrolyte layer slurry is prepared by adding toluene, a binder powder, a commercially available dispersant, etc. to the ZrO ₂ powder in which the rare earth element oxide is solid-dissolved, and using this, it is molded by a method such as a doctor blade. A sheet-like solid electrolyte layer molded body is produced.

  The fuel electrode layer slurry is applied to one side of the obtained sheet-shaped solid electrolyte layer molding and dried to form a fuel electrode layer molding, and the intermediate layer slurry is applied to the other side. Thus, an intermediate layer molded body is formed, and a sheet-shaped three-layer molded body is formed. The surface on the fuel electrode layer molded body side of the sheet-shaped three-layer molded body in which the fuel electrode layer molded body, the intermediate layer molded body, and the solid electrolyte layer molded body are stacked is laminated on the support molded body, and FIG. A laminated molded body as shown is formed.

Thereafter, for example, a slurry obtained by adding toluene, binder powder, a commercially available dispersant, etc. to ZrO ₂ powder in which ₃ to 5 mol% of Y ₂ O ₃ is solid-dissolved, is obtained by a method such as a doctor blade. A sheet-like molded body constituting a cylindrical body having the first opening 9a as shown in FIG.

Next, as shown in FIG.6 (d), it winds and laminate | stacks so that the 3 layer molded object of a support body molded object may be located in the 1st opening part of the sheet-like molded object which comprises a cylindrical body. After winding, the second
An opening 9a is formed. FIG. 6 (e) shows a front surface and a back surface in a state where the cylindrical body molded body is wound around the support body molded body.

Next, the laminated molded body is calcined at 800 to 1200 ° C. for 2 to 6 hours. Subsequently, an interconnector layer material (for example, LaCrMgO ₃ -based oxide powder), an organic binder, and a solvent are mixed to prepare a slurry.

Subsequently, when an adhesion layer molded body is formed between the support 1 and the interconnector layer 8, it is produced as follows. For example, ZrO _{2 in} which Y ₂ O ₃ is dissolved and NiO are mixed and dried so that the volume ratio is in the range of 40:60 to 60:40, and an organic binder or the like is added to adjust the adhesion layer slurry. Then, the adhesion layer molded body is formed by coating the upper surface of the wall portion constituting the second opening of the cylindrical body molded body and the support molded body in the second opening.

  Thereafter, the interconnector layer slurry is applied onto the adhesion layer molded body to produce a laminated molded body.

  Subsequently, the above-mentioned laminated molded body is subjected to binder removal treatment, and is simultaneously sintered (simultaneously fired) in the atmosphere at 1400 to 1450 ° C. for 2 to 6 hours.

Furthermore, a slurry containing an oxygen electrode layer material (for example, LaCoO ₃ oxide powder), a solvent and a pore-forming agent is applied onto the intermediate layer by dipping or the like, and baked at 1000 to 1300 ° C. for 2 to 6 hours. Thus, the fuel cell 10 of the present embodiment having the structure shown in FIGS.

  In addition, the structure as shown in FIG. 3B is, for example, a sheet-like molded body that forms a cylindrical body in which the size of the first opening 9a is smaller than that of the three-layer molded body. The wall part which comprises the 1st opening part 9a can be obtained by winding and laminating | stacking so that it may overlap with the outer peripheral part of the 3 layer molded object of a support body molded object. Further, the structure as shown in FIG. 4 is obtained by, for example, winding and laminating a sheet-shaped molded body constituting a cylindrical body around a support molded body, and then slurrying the fuel electrode layer in the first opening 9a, solid It can be obtained by applying an electrolyte layer slurry and an intermediate layer slurry. In addition, the slurry for solid electrolyte layers and the slurry for intermediate | middle layers are apply | coated also to the upper surface of the wall part which comprises the 1st opening part 9a.

  FIG. 7 shows an example of a cell stack device configured by electrically connecting a plurality of the above-described fuel cells 10 in series via a current collecting member 13, and (a) shows a cell. The side view which shows a stack apparatus roughly, (b) is a partial expanded sectional view of the cell stack apparatus of (a), and has extracted and shown the part enclosed with the broken line shown by (a). In addition, in (b), the part corresponding to the part enclosed by the broken line shown in (a) is shown by an arrow, and in the fuel cell 10 shown in (b), the intermediate layer described above is shown. Some members such as are omitted.

  In the cell stack device, each fuel cell 10 is arranged via an elastic current collecting member 13 to constitute a cell stack 12, and the lower end of each fuel cell 10 is a fuel cell. A gas tank 16 for supplying fuel gas to the cell 10 is fixed with an insulating adhesive 17 such as a glass sealing material.

  In addition, the cell stack 12 is sandwiched from both ends of the fuel cell 10 in the cell arrangement direction x by the elastically deformable conductive member 14 whose lower end is fixed to the gas tank 16.

Further, in the conductive member 14 shown in FIG. 7, in order to draw out the current generated by the power generation of the cell stack 12 (fuel cell 10) in a shape extending outward along the cell arrangement direction x of the fuel cell 10. Current extraction part 15 is provided.

  FIG. 8 shows a structure for fixing the lower end of the fuel cell 10 to the gas tank 16. The lower end portion of the fuel battery cell 10 is inserted into an opening formed in the gas tank 10 and fixed by an adhesive 17 such as a glass seal material. 8A is a side view seen from the cell arrangement direction x, and FIG. 8B is a side view seen from the cell width direction W. FIG.

  That is, two openings into which the lower ends of the two cell stacks 12 are inserted are formed on the upper wall of the thin box-shaped gas tank 10, and the lower ends of the cell stack 12 are respectively formed in these openings. In the inserted state, it is bonded and fixed with an adhesive 17. The adhesive 17 is filled and sealed between the fuel cell 10 between the cell stack 12 and the wall surface constituting the opening of the upper wall of the gas tank 10.

  As shown in FIG. 8, the adhesive 17 is joined to the lower end portion of the cylindrical body 9, and the lower end portion of the interconnector layer 8 is not embedded in the adhesive 17. Therefore, for example, by forming the cylindrical body 9 with a high-strength material or increasing the thickness of the cylindrical body 9, the lower end portion of the fuel cell 10 can be reinforced, and the occurrence of cracks can be suppressed.

  That is, stress may be generated at the lower end portion of the fuel battery cell 10 due to the difference in materials constituting the gas tank 16, the fuel battery cell 10, and the adhesive 17 made of a heat resistant alloy, and cracks may occur. The body 9 can be reinforced, and the generation of cracks at the lower end of the fuel cell 10 can be prevented.

Further, the interconnector layer 8 made of LaCrO ₃ oxide is reduced and expanded when exposed to a reducing atmosphere, but the lower end portion of the interconnector layer 8 is not covered with the adhesive 17 as shown in FIG. The stress between the portion covered with the adhesive 17 and the portion not covered can be reduced, and the occurrence of cracks at the lower end of the fuel cell 10 can be suppressed.

  FIG. 9 is an external perspective view showing an example of the fuel cell module 18 in which the cell stack device is stored in the storage container. The cell stack device shown in FIG. 8 is stored in the storage container 19 having a rectangular parallelepiped shape. Configured.

  In order to obtain the fuel gas used in the fuel cell 10, a reformer 20 for reforming raw fuel such as natural gas or kerosene to generate fuel gas is disposed above the cell stack 12. ing. The fuel gas generated by the reformer 20 is supplied to the gas tank 16 via the gas flow pipe 21 and supplied to the fuel gas passage 2 provided inside the fuel cell 10 via the gas tank 16. .

  FIG. 9 shows a state in which a part (front and rear surfaces) of the storage container 19 is removed and the cell stack device and the reformer 20 stored inside are taken out rearward. In the fuel cell module 18 shown in FIG. 9, the cell stack device can be slid and stored in the storage container 19. The cell stack device may include the reformer 20.

Further, in FIG. 9, the oxygen-containing gas introduction member 22 provided inside the storage container 19 is disposed between a pair of cell stacks 12 juxtaposed to the gas tank 16, and the oxygen-containing gas flows into the fuel gas flow. In addition, an oxygen-containing gas is supplied to the lower end of the fuel cell 10 so that the side of the fuel cell 10 flows from the lower end toward the upper end. Then, the temperature of the fuel cell 10 can be increased by reacting the fuel gas discharged from the fuel gas passage 2 of the fuel cell 10 with the oxygen-containing gas and burning it on the upper end side of the fuel cell 10. This can accelerate the activation of the cell stack device. Further, by burning the fuel gas and the oxygen-containing gas discharged from the gas passage 2 of the fuel battery cell 10 on the upper end side of the fuel battery cell 10, the fuel cell 10 is placed above the fuel battery cell 10 (cell stack 12). The arranged reformer 20 can be warmed. Thereby, the reforming reaction can be efficiently performed in the reformer 20.

  Further, in the fuel cell module 18 of the present embodiment, the cell stack device using the above-described fuel cell 10 is housed in the housing container 19, so that the fuel cell has high power generation performance and improved long-term reliability. Module 18 may be used.

  FIG. 10 is a perspective view showing an example of a fuel cell device in which the fuel cell module 18 shown in FIG. 9 and an auxiliary machine for operating the cell stack device are housed in an outer case. In FIG. 10, a part of the configuration is omitted.

  The fuel cell device 23 shown in FIG. 10 has a module housing chamber in which an outer case made up of support columns 24 and an outer plate 25 is divided into upper and lower portions by a partition plate 26 and the upper side thereof houses the above-described fuel cell module 18. 27, the lower side is configured as an auxiliary equipment storage chamber 28 for storing auxiliary equipment for operating the fuel cell module 18. In addition, auxiliary machines stored in the auxiliary machine storage chamber 28 are not shown.

  In addition, the partition plate 26 is provided with an air circulation port 29 for flowing the air in the auxiliary machine storage chamber 28 to the module storage chamber 27 side, and a part of the exterior plate 25 constituting the module storage chamber 27 An exhaust port 30 for exhausting the air in the module storage chamber 27 is provided.

  In such a fuel cell device 23, as described above, the power generation performance is high by having the fuel cell module 18 housed in the module storage chamber 27 with high power generation performance and improved reliability. The fuel cell device 23 is high and has high reliability.

  As mentioned above, this invention is not limited to the above-mentioned embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention. For example, a fuel cell in which an oxygen electrode layer, a solid electrolyte layer, and a fuel electrode layer are disposed on a conductive support may be used. Further, for example, in the above embodiment, the fuel electrode layer 3, the solid electrolyte layer 4, and the oxygen electrode layer 6 are laminated on the support 1, but the fuel electrode layer itself is used as the support 1 without using the support 1. The support 1 may be provided with a solid electrolyte layer 4 and an oxygen electrode layer 6.

  In the above embodiment, the hollow plate type solid oxide fuel cell has been described. However, it is needless to say that a cylindrical solid oxide fuel cell may be used. Moreover, you may form various intermediate | middle layers according to a function between each member.

  Moreover, in the said embodiment, although the case where it had the interconnector layer 8 was described, the case where it does not have an interconnector layer may be sufficient.

Furthermore, although the fuel cell, the cell stack device, the fuel cell module, and the fuel cell device have been described in the above embodiment, the present invention is not limited to this, and steam ( It can also be applied to an electrolysis cell (SOEC) that generates hydrogen and oxygen (O ₂ ) by electrolyzing (water), and an electrolysis module and electrolysis apparatus including the electrolysis cell.

1: support body 2: fuel gas passage 3: fuel electrode layer 4: solid electrolyte layer 6: oxygen electrode layer 8: interconnector layer 9: cylindrical body 9a: first opening 9b: second opening 18: fuel cell Module 23: Fuel cell device

The present invention, cell Le, the cell stack device, a module and a module accommodation device.

  In recent years, various fuel cell devices have been proposed in which a cell stack device formed by electrically connecting a plurality of solid oxide fuel cells in series is accommodated in a storage container as next-generation energy.

  As such a solid oxide fuel cell of the fuel cell device, for example, it has a pair of parallel flat surfaces, a fuel gas passage for allowing fuel gas to flow inside, and contains Ni What comprises the electroconductive support body formed by doing is known (for example, refer patent document 1). In Patent Document 1, a fuel electrode layer, a solid electrolyte layer, and an oxygen electrode layer are sequentially stacked on a flat surface on one side of a conductive support, and an interconnector layer is stacked on a flat surface on the other side. .

The solid oxide fuel cell includes a solid electrolyte layer formed of a dense ZrO ₂ oxide formed so as to surround the periphery of the conductive support, and a dense electrolyte at both ends of the solid electrolyte layer. The interconnector layer made of LaCrO ₃ oxide is joined so that both ends overlap each other, and the solid electrolyte layer and the interconnector layer surround the conductive support in an airtight manner, thereby supporting the conductive support. The fuel gas passing through the inside of the body is configured not to leak to the outside from the dense cylindrical body formed by the solid electrolyte layer and the interconnector layer.

JP 2008-84716 A

  In recent years, the ionic conductivity improves as the thickness of the solid electrolyte layer decreases, and the power generation performance of the fuel cell improves. Therefore, the thickness of the solid electrolyte layer is reduced in order to improve the power generation performance. However, if the thickness of the solid electrolyte layer is reduced in order to improve the power generation performance, the strength improvement effect by the solid electrolyte layer is lowered, and there is a possibility that cracks are likely to occur in the fuel cell.

The present invention, Rousset Le can suppress the generation of cracks, the cell stack device, and an object thereof is to provide a module and module accommodation device.

Cell Le of the present invention comprises a porous electrically conductive support with elongated, on the side surface of the support, provided so as to surround the support body, first the portion located on the side surface of the support An insulating dense cylindrical body having an opening, and a porous first electrode layer, a dense solid electrolyte layer, and a porous body provided on the support in the first opening of the cylindrical body And a second electrode layer, and an outer peripheral portion of the solid electrolyte layer is joined to the cylindrical body.

Also, cell Le of the present invention, the elongated porous conductive support serving as the first electrode layer, the side surface of the support, provided so as to surround the support, the said support An insulating dense cylindrical body having a first opening in a portion located on a side surface, and a dense solid electrolyte layer and a porous body provided on the support in the opening of the cylindrical body And a second electrode layer, and an outer peripheral portion of the solid electrolyte layer is bonded to the cylindrical body.

The cell stack device of the present invention, it becomes a plurality including the above cell Le, characterized by comprising electrically connecting the cell Le said plurality of.

Module of the present invention is characterized by formed by housing the cell stack device in the storage container.

Module accommodation device of the present invention, the above modules, the auxiliary device for operating the 該Mo joules and characterized by being accommodated in the exterior case.

The cell Le of the present invention, that the first opening of the tubular body is blocked by the solid electrolyte layer constituting the cylindrical body and cylindrical sealing layer a solid electrolyte layer, and its internal gas passageway While it is possible to improve the electrolytic performance by reducing the thickness of the solid electrolyte layer, the strength of the cylindrical body can be increased by, for example, forming the cylindrical body with a high-strength material or increasing the thickness of the cylindrical body. can be achieved, it can be suppressed cracking in cell.

Thereby, high performance can be provided long term reliable cell stack device, module, the module accommodation device.

1 shows a fuel cell, where (a) is a side view seen from the interconnector layer side, and (b) is a side view seen from the oxygen electrode layer side. FIG. 2A is a cross-sectional view taken along line 2a-2a in FIG. 1A, and FIG. 2B is a cross-sectional view taken along line 2b-2b in FIG. (A) is sectional drawing which shows the state which provided the solid electrolyte layer of the electric power generation element part in the opening part of a cylindrical body, (b) is the cylindrical body superimposed on the outer peripheral part of the solid electrolyte layer of an electric power generation element part. It is sectional drawing which shows a state. It is sectional drawing which shows the state in which the outer peripheral part of the solid electrolyte layer of an electric power generation element part has overlapped with the outer peripheral surface of the 1st opening part of a cylindrical body. The fuel cell of the form by which the interconnector layer is not provided in the upper end part is shown, (a) is the side view seen from the interconnector layer side, (b) is the side view seen from the oxygen electrode layer side. . It is explanatory drawing which shows the manufacturing method of the fuel battery cell of FIG. The cell stack apparatus is shown, (a) is a side view, (b) is an enlarged cross-sectional view showing a part of (a). 1 shows a state in which the fuel battery cell of FIG. 1 is bonded and fixed to a gas tank using an adhesive, wherein (a) is a side view seen from the cell arrangement direction, and (b) is a side view seen from the cell width direction ( (Partial cross section). It is an external appearance perspective view which shows an example of a fuel cell module. It is a perspective view which abbreviate | omits and shows a part of fuel cell apparatus.

1 and 2, which shows a fuel cell which is an example of a cell Le, FIG 1 (a), (b) each of the interconnector layer, a side view seen from the oxygen electrode layer side, FIG. 2 (a ) Is a cross-sectional view taken along line 2a-2a in FIG. 1A, and FIG. 2B is a cross-sectional view taken along line 2b-2b. In both drawings, a part of each component of the fuel cell 10 is shown enlarged.

As shown in FIG. 2, this fuel cell 10 is a hollow flat plate type, has a flat cross section, and has a long and porous conductive structure containing Ni having an elliptical columnar shape as a whole. A support 1 is provided. As shown in FIG. 2, the support 1 has a pair of flat surfaces n on the upper and lower surfaces, and has a pair of arcuate surfaces m that are provided in the cell width direction W and connect the pair of flat surfaces n. Yes. Inside the support 1, a plurality of fuel gas passages 2 are formed at appropriate intervals so as to penetrate in the length direction L of the fuel cell 10, and the fuel cell 10 is formed on the support 1 in various ways. It has the structure where the member of this was provided.

  And in this embodiment, the insulating dense cylindrical body 9 is provided on the side surface of the support body 1 so as to surround the support body 1, and the side surface of the support body 1 of this cylindrical body 9 is provided. Two first openings 9a and second openings 9b are formed in the position. In addition, as shown to Fig.1 (a), the recessed part formed in the upper end of the cylindrical body 9 like the 2nd opening part 9b is also defined as an opening part in this embodiment.

  The first opening 9 a is provided at the center of the cylindrical body 9 in the cell length direction L, is not provided at both ends of the cell length direction, and the second opening 9 b is formed on the cylindrical body 9. Although formed downward from the upper end of the cell length direction L, it is not provided at the lower end of the cell length direction L.

  A porous fuel electrode layer (first electrode layer) 3, a dense solid electrolyte layer 4, and a porous material are provided on the side surface (first side surface) of the support 1 in the first opening 9 a of the cylindrical body 9. An oxygen electrode layer (second electrode layer) 6 is provided, and a portion of the side surface (second side surface) of the support 1 in the second opening 9b of the cylindrical body 9 is formed of a dense conductive ceramic. A connector layer 8 is provided. In addition, the side surface of the support body 1 means a pair of flat surfaces n and a pair of arcuate surfaces m.

  That is, the cylindrical body 9 is formed so as to cover the pair of flat surfaces n and the pair of arcuate surfaces m, and the cylindrical body 9 on the one flat surface n has a rectangular first opening 9a. The cylindrical body 9 on the other flat surface n is provided with a rectangular second opening 9b.

  In the first opening 9a, as shown in FIGS. 2A and 3A, the fuel electrode layer (first electrode layer) 3, the solid electrolyte layer 4, and the oxygen electrode layer (second electrode layer) 6 are provided. These are formed in a rectangular shape, and the outer periphery of the solid electrolyte layer 4 is joined to the wall surface forming the first opening 9 a of the cylindrical body 9.

  In addition, a rectangular interconnector layer 8 is provided in the second opening 9b, and the outer peripheral portion of the interconnector layer 8 is joined to the wall surface and the upper surface of the wall portion constituting the first opening 9a of the cylindrical body 9. doing. The interconnector layer 8 is not formed at the lower end portion in the cell length direction L, and a cylindrical body is formed on the entire outer peripheral surface of the support 1 as shown in FIG.

  The cylindrical body 9 covers the pair of flat surfaces n and the arcuate surfaces m on both sides of the support 1 except for the portion of the support 1 where the solid electrolyte layer 4 and the interconnector layer 8 are provided. The thickness of the solid electrolyte layer 4 is preferably 30 μm or less, particularly 20 μm or less, and more preferably 15 μm or less from the viewpoint of improving power generation performance. The interconnector layer 8 also has a thickness of 70 μm or less, particularly 50 μm or less, because the thinner the interconnector layer 8, the better the conductivity.

  A porous oxygen electrode layer 6 is disposed on the surface of the solid electrolyte layer 4 so as to face the fuel electrode layer 3 via the intermediate layer 5. The intermediate layer 5 is formed on the solid electrolyte layer 4 on which the oxygen electrode layer 6 is formed. The oxygen electrode layer 6 is formed on the upper surface of the intermediate layer 5 and the upper surface of the wall portion constituting the first opening 9a.

  Here, in the fuel cell 10, the portion where the fuel electrode layer 3 and the oxygen electrode layer 6 face each other through the solid electrolyte layer 4 functions as a fuel cell to generate electric power. That is, an oxygen-containing gas such as air is allowed to flow outside the oxygen electrode layer 6, and a fuel gas (hydrogen-containing gas) is allowed to flow in the fuel gas passage 2 in the support 1 to generate power by heating to a predetermined operating temperature. . The current generated by such power generation is collected via the interconnector layer 8 provided on the support 1.

  That is, the dense cylindrical body 9 having gas barrier properties, the solid electrolyte layer 4 and the interconnector layer 8 surround the support 1 so that fuel gas flowing through the inside does not leak to the outside. In other words, the cylindrical body 9, the solid electrolyte layer 4 and the interconnector layer 8 form an elliptic cylindrical body having a gas barrier property, and the inside of the elliptic cylindrical body serves as a fuel gas flow path. The fuel gas supplied to the layer 3 and the oxygen-containing gas supplied to the oxygen electrode layer 6 are blocked by an elliptic cylinder. The dense cylindrical body 9, the solid electrolyte layer 4 and the interconnector layer 8 have a porosity of 5% or less, particularly 2% or less, as measured by a scanning electron micrograph using an image analyzer. The solid electrolyte layer 4 and the interconnector layer 8 are referred to.

The cylindrical body 9 may be a dense and high-strength material, but it is particularly desirable that the cylindrical body 9 be made of a solid electrolyte material. As the solid electrolyte material, a material constituting the solid electrolyte layer 4, for example, a zirconia-based oxide, a lanthanum galide-based oxide, or the like can be used. In particular, the same material as the solid electrolyte layer 4 is desirable. The solid electrolyte layer 4 and the cylindrical body 9 are preferably composed of ZrO ₂ containing a rare earth element. In this case, the cylindrical body 9 should have a rare earth element content less than the solid electrolyte layer 4. Is desirable from the viewpoint of improving the strength.

In particular, the solid electrolyte layer 4 is composed of partially stabilized zirconia, for example, ZrO ₂ in which ₃ to 15 mol%, particularly 7 to 9 mol% of Y ₂ O ₃ is dissolved, which improves power generation performance. Is desirable. The solid electrolyte material constituting the cylindrical body 9 is preferably the same partially stabilized zirconia and contains the same rare earth element as the solid electrolyte layer 4. Furthermore, it is desirable from the viewpoint of strength that the rare earth element is less than the solid electrolyte layer 4 and is made of, for example, ZrO ₂ in which ₃ to 5 mol% of Y ₂ O ₃ is dissolved.

  In the fuel cell 10 as described above, since the porous support 1 is surrounded by the dense seal body constituted by the cylindrical body 9, the solid electrolyte layer 4 and the interconnector layer 8, the cylindrical body 9 The interior can be a gas passage. Moreover, since the cylindrical body 9 exists in the portion where the solid electrolyte layer 4 and the interconnector layer 8 are not formed, the thickness of the solid electrolyte layer 4 and the interconnector layer 8 is reduced to improve the power generation performance. On the other hand, the cylindrical body 9 can be reinforced by increasing the thickness, or can be made of a high-strength material. In particular, the arcuate surface m of the support 1 or both ends of the support 1 in the cell length direction It is possible to suppress the occurrence of cracks in the part.

Conventionally, the interconnector layer 8 made of LaCrO ₃ -based oxide expands when exposed to a reducing atmosphere, and the porous conductive support 1 containing Ni is formed from the interconnector layer 8. Due to the elemental diffusion, it tends to expand when exposed to a reducing atmosphere. When the lower end of the fuel cell 10 is joined to the opening of the gas tank with an adhesive made of an inorganic material as shown in FIG. 8 to be described later, an interconnector is provided in a portion where the adhesive of the fuel cell 10 does not exist. While the layer 8 is intended to be reduced and expanded by being exposed to a reducing atmosphere, the adhesive layer suppresses the reduction and expansion of the interconnector layer 8 at the bonding portion of the fuel cell 10 with the adhesive. There was a risk that cracks would occur due to large stress at the lower end.

  On the other hand, in this embodiment, the interconnector layer 8 that is reduced and deformed is not formed at the lower end portion of the support 1 in the cell length direction L, and the cylindrical body 9 is formed. The lower end portion of the cylindrical body 9 can be joined with an adhesive, and the interconnector layer 8 portion can be structured not to be joined with an adhesive, whereby the stress at the lower end portion of the cell can be reduced and cracking can be suppressed. .

  1 and 2, the case where the outer peripheral surface of the solid electrolyte layer 4 is joined to the wall surface forming the first opening 9a of the cylindrical body 9 as shown in FIG. However, as shown in FIG. 3B, the outer peripheral surface of the solid electrolyte layer 4 (intermediate layer 5) is overlapped with the outer peripheral portion constituting the first opening 9 a of the cylindrical body 9 via the intermediate layer 5. And the case where the outer peripheral surface of the solid electrolyte layer 4 joins to the wall surface which comprises the 1st opening part 9a may be sufficient. Furthermore, as shown in FIG. 4, the outer peripheral portion of the solid electrolyte layer 4 may be superposed on and bonded to the outer peripheral surface of the first opening 9 a of the cylindrical body 9.

  FIG. 5 shows another form of the fuel cell 10. In this form, the second opening 9 b provided with the interconnector layer 8 is cylindrical at both ends of the support 1 in the cell length direction L. It is provided in a state where a part of the body 9 exists. In this embodiment, since the interconnector layer 8 is not formed at both ends in the cell length direction L of the support 1, stress at both ends of the cell due to reduction expansion of the interconnector layer 8 can be reduced.

  Below, each member which comprises the fuel cell 10 of this embodiment is demonstrated.

  The conductive support 1 is required to be gas permeable in order to allow fuel gas to permeate to the fuel electrode layer 3 and to be conductive in order to collect current via the interconnector layer 8. From, for example, it is preferable to form Ni and / or NiO and an inorganic oxide such as a specific rare earth oxide.

The specific rare earth oxide is used to make the thermal expansion coefficient of the support 1 close to the thermal expansion coefficient of the solid electrolyte layer 4, and is Y, Lu, Yb, Tm, Er, Ho, Dy, Gd. Rare earth oxides containing at least one element selected from the group consisting of Sm, Pr can be used in combination with Ni and / or NiO. Specific examples of such rare earth oxides include Y ₂ O ₃ , Lu ₂ O ₃ , Yb ₂ O ₃ , Tm ₂ O ₃ , Er ₂ O ₃ , Ho ₂ O ₃ , Dy ₂ O ₃ , Gd ₂ O. ₃ , Sm ₂ O ₃ , Pr ₂ O ₃ can be exemplified, there is almost no solid solution and reaction with Ni and / or NiO, the thermal expansion coefficient is the same as that of the solid electrolyte layer 4, and From the point of being cheap, Y ₂ O ₃ and Yb ₂ O ₃ are preferable.

  In the present embodiment, Ni and / or NiO: rare earth oxide = 35: 65 in that the good conductivity of the support 1 is maintained and the thermal expansion coefficient is approximated to that of the solid electrolyte layer 4. It is preferably present in a volume ratio of 65:35. The support 1 may contain other metal components and oxide components as long as required characteristics are not impaired.

  Further, since the support 1 is required to have fuel gas permeability, it is porous and usually has an open porosity of 30% or more, particularly 35 to 50%. . Further, the conductivity of the support 1 is preferably 300 S / cm or more, and particularly preferably 440 S / cm or more.

  Note that the length of the flat surface n of the support 1 (the length of the support 1 in the cell width direction W) is, for example, 15 to 35 mm, and the length of the arcuate surface m (the length of the arc) is 2 to 8 mm. The thickness of the support 1 (thickness between the flat surfaces n) is 1.5 to 5 mm. The length of the support 1 is, for example, 100 to 300 mm.

The fuel electrode layer 3 causes an electrode reaction, and can be formed of a well-known porous conductive ceramic. For example, it can be formed from ZrO _{2 in which a} rare earth element oxide is dissolved or CeO _{2 in} which a rare earth element oxide is dissolved, and Ni and / or NiO. As the rare earth element, the rare earth elements exemplified in the conductive support 1 can be used. For example, the rare earth element can be formed from ZrO ₂ (YSZ) in which Y ₂ O ₃ is dissolved and Ni and / or NiO. .

The content of ZrO ₂ in which the rare earth element oxide is dissolved in the fuel electrode layer 3 or CeO ₂ in which the rare earth element oxide is dissolved is preferably in the range of 35 to 65% by volume, and Ni or The content of NiO is preferably 65 to 35% by volume. Further, the open porosity of the fuel electrode layer 3 is preferably 15% or more, particularly preferably in the range of 20 to 40%, and the thickness thereof is preferably 1 to 30 μm.

The solid electrolyte layer 4 is preferably made of a ceramic made of partially stabilized or stabilized ZrO ₂ containing 3 to 15 mol% of a rare earth element such as Y, Sc, or Yb. As the rare earth element, Y is preferable because it is inexpensive. The solid electrolyte layer 4 is not limited to ceramics made of partially stabilized or stabilized ZrO _2, and may of course be a conventionally known, for example, lanthanum galade based solid electrolyte layer. .

  The solid electrolyte layer 4 and the oxygen electrode layer 6 are strongly bonded to each other between the solid electrolyte layer 4 and the oxygen electrode layer 6 described later, and the components of the solid electrolyte layer 4 react with the components of the oxygen electrode layer 6. Thus, the intermediate layer 5 is formed for the purpose of suppressing the formation of a reaction layer having a high electrical resistance.

The intermediate layer 5 is made of a CeO ₂ based sintered body containing a rare earth element other than Ce. For example, (CeO ₂ ) _1-x (REO _1.5 ) _x (where RE is Sm , Y, Yb, and Gd, and x preferably has a composition represented by the following formula: 0 <x ≦ 0.3. Furthermore, from the viewpoint of reducing electrical resistance, it is preferable to use Sm or Gd as RE, for example, it is preferably made of CeO ₂ in which 10 to 20 mol% of SmO _1.5 or GdO _1.5 is dissolved. .

The oxygen electrode layer 6 is preferably formed of a conductive ceramic made of a so-called ABO ₃ type perovskite oxide. Such perovskite oxides include La-containing transition metal perovskite oxides, particularly at least one of LaMnO ₃ oxides, LaFeO ₃ oxides, and LaCoO ₃ oxides in which Sr and La coexist at the A site. LaCoO ₃ oxides are particularly preferable from the viewpoint of high electrical conductivity at an operating temperature of about 600 to 1000 ° C. In the perovskite oxide, Fe and Mn may exist together with Co at the B site.

  Further, the oxygen electrode layer 6 needs to have gas permeability. Therefore, the conductive ceramic (perovskite oxide) forming the oxygen electrode layer 6 has an open porosity of 20% or more, particularly 30 to 50%. It is preferable that it exists in the range. Furthermore, the thickness of the oxygen electrode layer 6 is preferably 30 to 100 μm from the viewpoint of current collection.

The interconnector layer 8 is made of conductive ceramics. In order to come into contact with fuel gas (hydrogen-containing gas) and oxygen-containing gas, it is necessary to have reduction resistance and oxidation resistance. For this reason, for example, lanthanum chromite-based perovskite oxides (LaCrO ₃ -based oxides) are used as conductive ceramics having reduction resistance and oxidation resistance, and particularly the heat of the support 1 and the solid electrolyte layer 4. For the purpose of approaching the expansion coefficient, a LaCrMgO ₃ -based oxide in which Mg is present at the B site is used. The interconnector layer 8 material may be conductive ceramics and is not particularly limited.

  The thickness of the interconnector layer 8 is preferably 10 to 70 μm from the viewpoint of preventing gas leakage and electrical resistance. Within this range, gas leakage can be prevented and electrical resistance can be reduced.

  Further, an adhesion layer (not shown) is formed between the support 1 and the interconnector layer 8 in order to reduce the difference in thermal expansion coefficient between the interconnector layer 8 and the support 1. Can do.

Such an adhesion layer may have a composition similar to that of the fuel electrode layer 3. For example, it can be formed from at least one of rare earth oxide, ZrO _{2 in which} a rare earth element oxide is dissolved, and CeO ₂ in which a rare earth element oxide is dissolved, and Ni and / or NiO. More specifically, for example, a composition composed of Y ₂ O ₃ and Ni and / or NiO, a composition composed of ZrO ₂ (YSZ) in which Y ₂ O ₃ is dissolved, and Ni and / or NiO, Y, Sm, Gd It can be formed from a composition composed of CeO ₂ and Ni and / or NiO in which an oxide such as oxide is dissolved. Note that the volume ratio of ZrO ₂ (CeO ₂ ) in which the rare earth oxide or rare earth element oxide is dissolved and Ni and / or NiO is preferably in the range of 40:60 to 60:40.

  An example of a method for producing the fuel battery cell 10 of the present embodiment described above will be described.

First, for example, Ni and / or NiO powder, a rare earth oxide powder such as Y ₂ O ₃ , an organic binder, and a solvent are mixed to prepare a clay, and this clay is used for extrusion molding. As shown in FIG. 6 (a), a support molded body is prepared and dried. In addition, you may use the calcined body which calcined the support body molded object at 900-1000 degreeC for 2 to 6 hours as a support body molded object.

Next, for example, according to a predetermined composition, raw materials of NiO and ZrO ₂ (YSZ) in which Y ₂ O ₃ is dissolved are weighed and mixed. Thereafter, an organic binder and a solvent are mixed with the mixed powder to prepare a slurry for the fuel electrode layer.

Further, for example, CeO ₂ powder in which GdO _1.5 is dissolved is heat-treated at 800 to 900 ° C. for 2 to 6 hours to adjust the raw material powder for the intermediate layer molded body. Toluene is added as a solvent to this raw material powder to prepare an intermediate layer slurry.

Then, a solid electrolyte layer slurry is prepared by adding toluene, a binder powder, a commercially available dispersant, etc. to the ZrO ₂ powder in which the rare earth element oxide is solid-dissolved, and using this, it is molded by a method such as a doctor blade. A sheet-like solid electrolyte layer molded body is produced.

  The fuel electrode layer slurry is applied to one side of the obtained sheet-shaped solid electrolyte layer molding and dried to form a fuel electrode layer molding, and the intermediate layer slurry is applied to the other side. Thus, an intermediate layer molded body is formed, and a sheet-shaped three-layer molded body is formed. The surface on the fuel electrode layer molded body side of the sheet-shaped three-layer molded body in which the fuel electrode layer molded body, the intermediate layer molded body, and the solid electrolyte layer molded body are stacked is laminated on the support molded body, and FIG. A laminated molded body as shown is formed.

Thereafter, for example, a slurry obtained by adding toluene, binder powder, a commercially available dispersant, etc. to ZrO ₂ powder in which ₃ to 5 mol% of Y ₂ O ₃ is solid-dissolved, is obtained by a method such as a doctor blade. A sheet-like molded body constituting a cylindrical body having the first opening 9a as shown in FIG.

  Next, as shown in FIG.6 (d), it winds and laminate | stacks so that the 3 layer molded object of a support body molded object may be located in the 1st opening part of the sheet-like molded object which comprises a cylindrical body. After the winding, the second opening 9a is formed. FIG. 6 (e) shows a front surface and a back surface in a state where the cylindrical body molded body is wound around the support body molded body.

Next, the laminated molded body is calcined at 800 to 1200 ° C. for 2 to 6 hours. Subsequently, an interconnector layer material (for example, LaCrMgO ₃ -based oxide powder), an organic binder, and a solvent are mixed to prepare a slurry.

Subsequently, when an adhesion layer molded body is formed between the support 1 and the interconnector layer 8, it is produced as follows. For example, ZrO _{2 in} which Y ₂ O ₃ is dissolved and NiO are mixed and dried so that the volume ratio is in the range of 40:60 to 60:40, and an organic binder or the like is added to adjust the adhesion layer slurry. Then, the adhesion layer molded body is formed by coating the upper surface of the wall portion constituting the second opening of the cylindrical body molded body and the support molded body in the second opening.

  Thereafter, the interconnector layer slurry is applied onto the adhesion layer molded body to produce a laminated molded body.

  Subsequently, the above-mentioned laminated molded body is subjected to binder removal treatment, and is simultaneously sintered (simultaneously fired) in the atmosphere at 1400 to 1450 ° C. for 2 to 6 hours.

Furthermore, a slurry containing an oxygen electrode layer material (for example, LaCoO ₃ oxide powder), a solvent and a pore-forming agent is applied onto the intermediate layer by dipping or the like, and baked at 1000 to 1300 ° C. for 2 to 6 hours. Thus, the fuel cell 10 of the present embodiment having the structure shown in FIGS.

  In addition, the structure as shown in FIG. 3B is, for example, a sheet-like molded body that forms a cylindrical body in which the size of the first opening 9a is smaller than that of the three-layer molded body. The wall part which comprises the 1st opening part 9a can be obtained by winding and laminating | stacking so that it may overlap with the outer peripheral part of the 3 layer molded object of a support body molded object. Further, the structure as shown in FIG. 4 is obtained by, for example, winding and laminating a sheet-shaped molded body constituting a cylindrical body around a support molded body, and then laminating a slurry for a fuel electrode layer and a solid in the first opening 9a. It can be obtained by applying an electrolyte layer slurry and an intermediate layer slurry. In addition, the slurry for solid electrolyte layers and the slurry for intermediate | middle layers are apply | coated also to the upper surface of the wall part which comprises the 1st opening part 9a.

  FIG. 7 shows an example of a cell stack device configured by electrically connecting a plurality of the above-described fuel cells 10 in series via a current collecting member 13, and (a) shows a cell. The side view which shows a stack apparatus roughly, (b) is a partial expanded sectional view of the cell stack apparatus of (a), and has extracted and shown the part enclosed with the broken line shown by (a). In addition, in (b), the part corresponding to the part enclosed by the broken line shown in (a) is shown by an arrow, and in the fuel cell 10 shown in (b), the intermediate layer described above is shown. Some members such as are omitted.

In the cell stack device, each fuel cell 10 is arranged via an elastic current collecting member 13 to constitute a cell stack 12, and the lower end of each fuel cell 10 is a fuel cell. A gas tank 16 for supplying fuel gas to the cell 10 is fixed with an insulating adhesive 17 such as a glass sealing material.

  In addition, the cell stack 12 is sandwiched from both ends of the fuel cell 10 in the cell arrangement direction x by the elastically deformable conductive member 14 whose lower end is fixed to the gas tank 16.

  Further, in the conductive member 14 shown in FIG. 7, in order to draw out the current generated by the power generation of the cell stack 12 (fuel cell 10) in a shape extending outward along the cell arrangement direction x of the fuel cell 10. Current extraction part 15 is provided.

  FIG. 8 shows a structure for fixing the lower end of the fuel cell 10 to the gas tank 16. The lower end portion of the fuel battery cell 10 is inserted into an opening formed in the gas tank 10 and fixed by an adhesive 17 such as a glass seal material. 8A is a side view seen from the cell arrangement direction x, and FIG. 8B is a side view seen from the cell width direction W. FIG.

  That is, two openings into which the lower ends of the two cell stacks 12 are inserted are formed on the upper wall of the thin box-shaped gas tank 10, and the lower ends of the cell stack 12 are respectively formed in these openings. In the inserted state, it is bonded and fixed with an adhesive 17. The adhesive 17 is filled and sealed between the fuel cell 10 between the cell stack 12 and the wall surface constituting the opening of the upper wall of the gas tank 10.

  As shown in FIG. 8, the adhesive 17 is joined to the lower end portion of the cylindrical body 9, and the lower end portion of the interconnector layer 8 is not embedded in the adhesive 17. Therefore, for example, by forming the cylindrical body 9 with a high-strength material or increasing the thickness of the cylindrical body 9, the lower end portion of the fuel cell 10 can be reinforced, and the occurrence of cracks can be suppressed.

  That is, stress may be generated at the lower end portion of the fuel battery cell 10 due to the difference in materials constituting the gas tank 16, the fuel battery cell 10, and the adhesive 17 made of a heat resistant alloy, and cracks may occur. The body 9 can be reinforced, and the generation of cracks at the lower end of the fuel cell 10 can be prevented.

Further, the interconnector layer 8 made of LaCrO ₃ oxide is reduced and expanded when exposed to a reducing atmosphere, but the lower end portion of the interconnector layer 8 is not covered with the adhesive 17 as shown in FIG. The stress between the portion covered with the adhesive 17 and the portion not covered can be reduced, and the occurrence of cracks at the lower end of the fuel cell 10 can be suppressed.

  FIG. 9 is an external perspective view showing an example of the fuel cell module 18 in which the cell stack device is stored in the storage container. The cell stack device shown in FIG. 8 is stored in the storage container 19 having a rectangular parallelepiped shape. Configured.

  In order to obtain the fuel gas used in the fuel cell 10, a reformer 20 for reforming raw fuel such as natural gas or kerosene to generate fuel gas is disposed above the cell stack 12. ing. The fuel gas generated by the reformer 20 is supplied to the gas tank 16 via the gas flow pipe 21 and supplied to the fuel gas passage 2 provided inside the fuel cell 10 via the gas tank 16. .

FIG. 9 shows a state in which a part (front and rear surfaces) of the storage container 19 is removed and the cell stack device and the reformer 20 stored inside are taken out rearward. In the fuel cell module 18 shown in FIG. 9, the cell stack device can be slid and stored in the storage container 19. The cell stack device may include the reformer 20.

  Further, in FIG. 9, the oxygen-containing gas introduction member 22 provided inside the storage container 19 is disposed between a pair of cell stacks 12 juxtaposed to the gas tank 16, and the oxygen-containing gas flows into the fuel gas flow. In addition, an oxygen-containing gas is supplied to the lower end of the fuel cell 10 so that the side of the fuel cell 10 flows from the lower end toward the upper end. Then, the temperature of the fuel cell 10 can be increased by reacting the fuel gas discharged from the fuel gas passage 2 of the fuel cell 10 with the oxygen-containing gas and burning it on the upper end side of the fuel cell 10. This can accelerate the activation of the cell stack device. Further, by burning the fuel gas and the oxygen-containing gas discharged from the gas passage 2 of the fuel battery cell 10 on the upper end side of the fuel battery cell 10, the fuel cell 10 is placed above the fuel battery cell 10 (cell stack 12). The arranged reformer 20 can be warmed. Thereby, the reforming reaction can be efficiently performed in the reformer 20.

  Further, in the fuel cell module 18 of the present embodiment, the cell stack device using the above-described fuel cell 10 is housed in the housing container 19, so that the fuel cell has high power generation performance and improved long-term reliability. Module 18 may be used.

  FIG. 10 is a perspective view showing an example of a fuel cell device in which the fuel cell module 18 shown in FIG. 9 and an auxiliary machine for operating the cell stack device are housed in an outer case. In FIG. 10, a part of the configuration is omitted.

  The fuel cell device 23 shown in FIG. 10 has a module housing chamber in which an outer case made up of support columns 24 and an outer plate 25 is divided into upper and lower portions by a partition plate 26 and the upper side thereof houses the above-described fuel cell module 18. 27, the lower side is configured as an auxiliary equipment storage chamber 28 for storing auxiliary equipment for operating the fuel cell module 18. In addition, auxiliary machines stored in the auxiliary machine storage chamber 28 are not shown.

  In addition, the partition plate 26 is provided with an air circulation port 29 for flowing the air in the auxiliary machine storage chamber 28 to the module storage chamber 27 side, and a part of the exterior plate 25 constituting the module storage chamber 27 An exhaust port 30 for exhausting the air in the module storage chamber 27 is provided.

  In such a fuel cell device 23, as described above, the power generation performance is high by having the fuel cell module 18 housed in the module storage chamber 27 with high power generation performance and improved reliability. The fuel cell device 23 is high and has high reliability.

  As mentioned above, this invention is not limited to the above-mentioned embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention. For example, a fuel cell in which an oxygen electrode layer, a solid electrolyte layer, and a fuel electrode layer are disposed on a conductive support may be used. Further, for example, in the above embodiment, the fuel electrode layer 3, the solid electrolyte layer 4, and the oxygen electrode layer 6 are laminated on the support 1, but the fuel electrode layer itself is used as the support 1 without using the support 1. The support 1 may be provided with a solid electrolyte layer 4 and an oxygen electrode layer 6.

  In the above embodiment, the hollow plate type solid oxide fuel cell has been described. However, it is needless to say that a cylindrical solid oxide fuel cell may be used. Moreover, you may form various intermediate | middle layers according to a function between each member.

  Moreover, in the said embodiment, although the case where it had the interconnector layer 8 was described, the case where it does not have an interconnector layer may be sufficient.

Furthermore, the fuel cell in the above embodiment, the cell stack device has been described the fuel cell module and fuel cell device, the present invention is not limited thereto, by applying the steam and voltage cell Le vapor ( It can also be applied to an electrolysis cell (SOEC) that generates hydrogen and oxygen (O ₂ ) by electrolyzing (water), and an electrolysis module and electrolysis apparatus including the electrolysis cell.

1: support body 2: fuel gas passage 3: fuel electrode layer 4: solid electrolyte layer 6: oxygen electrode layer 8: interconnector layer 9: cylindrical body 9a: first opening 9b: second opening 18: fuel cell Module 23: Fuel cell device

Claims (9)

  A long and porous conductive support, and an insulating material provided on a side surface of the support so as to surround the support and having a first opening in a portion located on the side of the support A dense cylindrical body, and a porous first electrode layer, a dense solid electrolyte layer, and a porous second electrode layer provided on the support in the first opening of the cylindrical body; And an outer peripheral portion of the solid electrolyte layer is joined to the cylindrical body.   A long porous conductive support serving as a first electrode layer, and a first opening in a side surface of the support that is provided so as to surround the support and is located on the side of the support And an insulating dense cylindrical body having a portion, and a dense solid electrolyte layer and a porous second electrode layer provided on the support in the first opening of the cylindrical body. And an outer peripheral part of the solid electrolyte layer is joined to the cylindrical body.   The solid electrolyte layer is provided on the first side surface of the support, and a second opening is provided in a portion of the cylindrical body located on the second side of the support. The electrolytic cell according to claim 1, wherein an interconnector layer is provided on the support.   4. The electrolytic cell according to claim 1, wherein the solid electrolyte layer and the cylindrical body are made of a solid electrolyte material. 5. The solid electrolyte material constituting the solid electrolyte layer and the cylindrical body is made of a ZrO ₂ -based material containing a rare earth element, and the cylindrical body has less rare earth element content than the solid electrolyte layer. The electrolysis cell according to claim 4 characterized by things.   A cell stack device comprising a plurality of the electrolysis cells according to any one of claims 1 to 5 and electrically connecting the plurality of electrolysis cells.   7. The cell stack device according to claim 6, wherein one end portion in the length direction of the electrolytic cell is joined to a gas tank with an insulating adhesive.   An electrolytic module comprising the cell stack device according to claim 6 or 7 in a storage container.   9. An electrolysis apparatus comprising the electrolysis module according to claim 8 and an auxiliary machine for operating the electrolysis module housed in an outer case.

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