JP5196216B2 - Electrochemical reactor - Google Patents

Description

  The present invention relates to a cell integration unit and an electrochemical reactor, and more particularly, to form an electrochemical cell on the inner wall surface of all or part of the through holes included in the integrated structure of the through holes made of an electrode material. The present invention relates to a cell integrated unit having the structure described above and a high-performance small-sized and high-efficiency electrochemical reactor composed thereof. The present invention is a cell integrated unit having a structure in which an electrochemical cell is formed on the inner wall surface of a through-hole included in an integrated structure of through-holes made of an electrode material, and the size of the through-hole is 1 mm or less, It is an object of the present invention to provide a cell integrated unit which can achieve high output by using the inner wall surface of the through hole as a structural support and an electrode layer of an electrochemical reaction cell, and a high performance electrochemical reactor composed thereof.

  As an application example of an electrochemical reactor, there is a solid oxide fuel cell (hereinafter referred to as “SOFC”) using a solid electrolyte having oxide ion conductivity as an electrolyte. The basic structure of this SOFC is composed of a single cell in which three layers of an air electrode / solid electrolyte / fuel electrode are joined. The geometric shape of the SOFC single cell can be classified into a flat plate type and a tubular type.

  As a volumetric power density, a flat plate type SOFC is advantageous, but in order to use the flat plate type as an electrochemical reactor, it is necessary to laminate separators and single cells alternately, and there is a problem in the gas sealing method and the like. was there. Further, in order to further increase the output, it is necessary to increase the area of the flat plate type single cell. However, since the conventional flat plate type single cell uses an electrode as a support, it gives a predetermined mechanical strength. Therefore, it was necessary to make the support thicker. For this reason, there existed a problem that the weight of a single cell became heavy and material cost also became large.

  As an alternative SOFC single cell integrated structure, a honeycomb structure has been proposed (Patent Documents 1 and 2). This is a structure in which the fuel electrode layer and the air electrode layer are alternately formed on the inner wall surface of each hole of the honeycomb support made of an electrolyte, and the fuel electrode hole and the air electrode hole are alternately arranged. It is necessary to supply gas and air.

  However, this type of honeycomb structure has advanced and highly accurate gas supply manifolds and gas seals that reduce the pore size or reduce the wall thickness of the electrolyte honeycomb support to improve the volumetric power density. Technology is required. Furthermore, in order to maintain the strength of the honeycomb structure, the wall thickness, that is, the thickness of the electrolyte needs to be 0.1 mm or more, and the SOFC cell performance is improved due to the ohmic loss in the electrolyte membrane. It was difficult.

  In addition, as proposed in the prior documents (Patent Document 3 and Patent Document 4), an SOFC single cell integration method using an electrode as a honeycomb support has also been reported. However, in Patent Document 3, half of the honeycomb holes are used as SOFC cells and the remaining half of the holes are used for gas supply. Therefore, as in Patent Document 1 and Patent Document 2, advanced gas supply manifolds and gas seals are used. There is a problem that technology is required.

  On the other hand, in Patent Document 4, SOFC cells are constructed in all of the honeycomb holes, and improvement measures such as gas sealing have been proposed, but unresolved technical problems such as a film formation technique on the wall surface of the through holes are proposed. Therefore, only 3-5 mm size has been tried as a through-hole so far, high pressure of 0.1-1 mm through-hole size, which has a low pressure loss and can expect a rapid increase in volume output density of the cell integrated unit. Realization of the region (see FIG. 1 attached hereto) has been difficult.

  In addition to SOFC, exhaust gas purification electrochemical reactors and hydrogen production reactors can be used as electrochemical reactor applications. As with the SOFC, there is a limit to downsizing and high integration of electrochemical reaction single cells. In the field, there has been a strong demand to develop a new technology that can achieve both miniaturization and high integration of electrochemical reaction cells.

  At present, an electrochemical reactor is constructed by combining a plurality of members such as an interconnector and a current collecting wire using a plate type or tubular type electrochemical reaction unit cell which is widely used. However, this type of method has a problem that the total size of the electrochemical reactor is large, and it is difficult to achieve high efficiency per unit volume. In addition, when trying to reduce the size of a single cell, advanced technology is required to form an interconnector and a gas seal, and there is a limit to downsizing a cell integrated unit and an electrochemical reactor composed thereof.

Japanese Patent Laid-Open No. 10-40934 JP-A-11-297344 JP 2002-216777 A JP 2004-152645 A

  Under such circumstances, the present inventors have conducted intensive research with the goal of developing a high-performance, compact, high-efficiency electrochemical reactor in view of the above-described conventional technology. As a result, the present inventors have succeeded in developing an electrochemical reactor having the integrated structure of No. 1 as a basic skeleton and completed the present invention. In the present invention, an electrochemical cell is formed on the inner wall surface of all or a part of the through-holes included in an integrated structure of through-holes having a through-hole size of 0.1 to 1 mm and an electrode material. It is an object of the present invention to provide a cell integrated unit having a structure using a wall surface as a structure support and an electrode layer of an electrochemical reaction cell, and an electrochemical reactor composed thereof.

The present invention for solving the above-described problems comprises the following technical means.
(1) A cell integrated unit having a structure in which an electrochemical cell is formed on the inner wall surface of a through-hole included in an integrated structure of through-holes made of an electrode material, the through-hole size being 0.1 to 1 mm, In addition, an electrochemical reaction cell is formed on the inner wall surface of all or part of the through-holes included in the integrated structure of through-holes made of electrode material, and the inner wall surface is used as a structure support body and an electrode layer of the electrochemical reaction cell A method of manufacturing a cell integrated unit having the structure used,
a) forming a molded body for an integrated structure of through-holes made of one electrode material by gel casting or extrusion, and drying or calcining;
b) a step of constructing a cell structure on the inner wall surface of all or a part of the through-holes contained in the molded body for the accumulated structure of through-holes obtained by slurry press-fitting method
A method for producing a cell integrated unit, comprising:
(2) A cell integrated unit obtained by the manufacturing method according to (1),
1) It is composed of an integrated structure of through-holes made of an electrode material and an electrochemical cell structure constructed on the inner wall surface of the through-holes included in the integrated structure. 2) The size of the through-holes is 0.1 to 0.1. 1 mm, and the inner wall surface is a structure support and an electrode layer of an electrochemical reaction cell. 3) The integrated structure is porous and has a porosity of 15 to 50%. 5) The integrated structure is made of an air electrode material. 5) The electrochemical reaction cell formed on the inner wall surface of all or part of the through holes included in the integrated structure made of the air electrode material is an air electrode. 6) The air electrode reaction active layer material is composed of Ag, La, Sr, Mn, Co, Fe, Sm, Ca, Ba, Ni, and the reaction active layer, the electrolyte layer, and the fuel electrode layer. , Mg elements or oxide compounds containing one or more of these elements Is al arrangement, 7) cells integrated unit which can be less volume output density at 600 ° C. is 2W / cc, characterized by.
(3) The cell integrated unit according to (2), wherein all or part of the end surface of the through hole included in the integrated structure is closed.
(4) In the above (2), the thickness of the air electrode reaction active layer is 1 to 10 microns, the thickness of the electrolyte layer is 1 to 50 microns, and the thickness of the fuel electrode layer is 1 to 100 microns. The cell integrated unit described.
(5) The cell integrated unit according to (2), wherein a wall of the structure that continues from the outer peripheral surface of the integrated structure is used as a gas flow path.
(6) The cell integrated unit according to (4), wherein the gas is a gas containing one or more kinds of fuel or oxygen.
(7) the electrolyte layer, ceria based _{oxide: Ce 1-x Ln x O} 2-x / 2 ( although, Ln is La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Including at least one of Tm, Yb, Lu, and Y, and x is 0.05 or more and 0.50 or less), scandia-stabilized zirconia oxide: a mol% Sc ₂ O ₃ -b mol% CeO ₂ -c mol % ZrO ₂ (where a is 8 or more and 15 or less, b is 0 or more and 2 or less, and a + b + c = 100), lanthanum gallate oxide: La _1-m Sr _m Ga _1-n Mg _n O ₃ (where m is The cell integrated unit according to (2), which is one type of 0.05 or more and 0.3 or less and n is 0 or more and 0.3 or less), or a composite of two or more types.
(8) The fuel electrode layer material is composed of Ni, Cu, Pt, Pd, Au, Ru, Co, La, Sr, Ti elements or an oxide compound containing one or more of these elements. The cell integrated unit according to 2).
(9) The cell integrated unit according to (8), wherein the fuel electrode layer material is a composite with the electrolyte material according to (7).
(10) The electrode layer includes an active auxiliary material, and the active auxiliary material includes Pt, Pd, Ag, Ba, Sr, Ca, Mg, K, Na, Mn, Fe, Co, Ni, Cu, Zn, The cell integrated unit according to (2), which is a metal containing at least one element of Ti, Al, Ga, Nb, Ta, V, and La, or an oxide containing one or more of these elements.
(11) the air electrode reaction active layer material is a composite comprising one or more of the activities auxiliary material according to the electrolyte layer material or (10) according to (7), to (2) The cell integrated unit described.
(12) An electrochemical reactor comprising the cell integrated unit according to any one of ( 2 ) to (11).

Next, the present invention will be described in more detail.
The present invention is a cell integrated unit having a structure in which an electrochemical cell is formed on the inner wall surface of a through-hole included in an integrated structure of through-holes made of an electrode material, and the through-hole size is 0.1 to 1 mm. And a cell integrated unit in which an electrolyte layer and a counter electrode layer are formed by multilayer coating on the inner wall surface of all or part of the through-holes included in the integrated structure of through-holes made of electrode material, and the cell It has a major feature in terms of a small and highly efficient electrochemical reactor in which electrochemical reaction cells composed of integrated units are integrated at high density.

  Conventional electrochemical reaction cells use an electrode material for the support, and it is necessary to provide a certain level of mechanical strength, so there is a limit to reducing the thickness of the support. It was disadvantageous. However, by constructing a high-density cell integrated unit and an electrochemical reactor composed thereof as shown in the present invention, it is possible to develop a high-performance, compact and highly efficient electrochemical reaction reactor.

  The electrochemical reaction reactor of the present invention is preferably applied to, for example, a solid oxide fuel cell (SOFC), an exhaust gas purification electrochemical reactor, a hydrogen production reactor, and the like. In the electrochemical reaction cell of the present invention, by appropriately selecting the air electrode, the electrolyte, and the fuel electrode material, the cell structure can be made a suitable structure. Can be provided.

  Next, the cell integrated unit of the present invention and the electrochemical reactor composed thereof will be described. The electrochemical reactor according to the present invention includes a plurality of cell integrated units in which electrochemical reaction cells are formed and integrated on all or part of inner wall surfaces of through holes included in an integrated structure of through holes made of an electrode material. Constructed by connecting in series or parallel. The shape of the electrochemical reaction single cell is determined by the shape of the through hole, but an appropriate shape such as a tubular shape or a square shape can be selected according to the purpose. In addition, as the integrated structure of the through holes, a honeycomb structure having a regular arrangement structure of hexagonal shape or quadrangular shape is exemplified, but the structure is not limited thereto.

  FIG. 2 shows an outline of a cell integrated unit that is a basic skeleton of an electrochemical reactor. A dense electrolyte layer 2 and the other electrode layer 3 are formed on the inner wall surface of the through hole of the through hole integrated structure 1 made of an electrode material. A similar cell structure comprising a wall / electrolyte layer 2 / electrode layer 3 comprising an integrated structure 1 of through-holes made of an electrode material can be applied to all or part of other through-holes contained in the integrated structure. By forming them simultaneously, a cell integrated unit is constructed, and further, an electrochemical reactor is constructed by joining the cell integrated units in series or in parallel.

  In the present invention, the integrated structure is porous and preferably has a porosity of 15 to 50%, and all or part of the end surface of the through-hole included in the integrated structure is closed. It is possible that Two types of structures are conceivable for the electrochemical cell using the through holes included in the integrated structure of through holes made of an electrode material. One is a structure in which the integrated structure is composed of an air electrode, and a cell structure is constructed on the inner wall surface of the through-hole. The other is a structure in which the integrated structure is composed of a fuel electrode and the cell is formed on the inner wall surface of the through-hole. It is a format for constructing a structure.

  Here, FIG. 3 shows a current collection loss estimated for an integrated structure of through holes made of an air electrode material or a fuel electrode material. In the present invention, the air electrode material is selected as the material for the integrated structure, because the current collection loss is suppressed to about 1/8 compared to the integrated structure made of the fuel electrode material. . The reason for this is that, for the internal electrode layer (electrode layer 3 in FIG. 2) having a very small current collection area, generally, an air electrode material whose conductivity is only about 1/10 of the fuel electrode material must be used. There is something to be done. If a highly conductive material such as metal can be added to the air electrode material and its conductivity can be increased, an integrated structure of through-holes made of fuel electrode material can also be applied, but the reactor operating temperature is several hundred degrees Celsius or higher. Therefore, the application of the highly conductive material-air electrode material composite and its long-term stability are currently unknown.

  In the present invention, the electrochemical reaction cell formed on all or part of the inner wall surface of the through-hole included in the integrated structure made of the air electrode material is formed by the two-layer coating of the electrolyte layer and the fuel electrode layer. An electrochemical reaction cell formed on the inner wall surface of all or part of the through-holes included in the integrated structure made of the air electrode material has an air electrode reaction active layer, an electrolyte layer, and a fuel electrode layer. For the inner wall coat layer, the thickness of the air electrode reaction active layer is 1 to 10 microns, the thickness of the electrolyte layer is 1 to 50 microns, and the thickness of the fuel electrode layer is 1 to 100 microns. It is preferable.

  The air electrode reaction active layer material used for the integrated structure is preferably, for example, Ag, La, Sr, Mn, Co, Fe, Sm, Ca, Ba, Ni, or Mg, or these elements. Oxides containing one or more kinds, and as the fuel electrode layer material, Ni, Cu, Pt, Pd, Au, Ru, Co, La, Sr, or Ti elements or oxidation containing one or more of these elements Or a composite or cermet containing at least one of an electrolyte layer material and an active auxiliary material described later.

As the electrolyte layer material, it is necessary to use a material having high ionic conductivity. Preferably, for example, a ceria-based oxide: Ce _1-x Ln _x O _{2−x / 2} (where Ln is Including at least one of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, and x is 0.05 to 0.50), scandia stabilization zirconia _{oxide: a mol% Sc 2 O 3} -b mol% CeO 2 -c mol% ZrO 2 ( where, a is 8 to 15, b is 0 to 2, and a + b + c = 100) , lanthanum gallate oxide : La _1-m Sr _m Ga _1-n Mg _n O ₃ (where m is 0.05 or more and 0.3 or less, n is 0 or more and 0.3 or less), or two or more kinds of composites It is desirable to use it.

  Moreover, in order to improve the electrode reaction activity of the said air electrode or a fuel electrode, it is also possible to combine an active auxiliary material. As a method of combining the active auxiliary material with the electrode material, the active auxiliary material is directly mixed into the electrode material, or an intermediate layer containing the active auxiliary material is inserted between the electrode and the electrolyte, depending on the purpose. The method can be selected.

  Further, as active auxiliary materials to be directly mixed with the electrode material, Pt, Pd, Ag, Ba, Sr, Ca, Mg, K, Na, Mn, Fe, Co, Ni, Cu, Zn, Ti, Al, Ga, A metal containing at least one element of Nb, Ta, V, or La, or an oxide containing one or more elements of these elements is desirable. As the active layer inserted between the air electrode and the electrolyte, it is preferable to use a composite containing one or more of the above-mentioned electrolyte material or the above-mentioned active auxiliary material with respect to the air electrode material.

  Next, the porosity required for the wall of the integrated structure of through holes made of an electrode material will be described. In order for all electrochemical reaction cells included in the cell integrated unit made of electrode material to function, the gas (SOFC air) required for the electrode reaction of the electrode material constituting the basic skeleton (through hole integrated structure) It is necessary that air in the polar material and fuel gas in the fuel electrode material for SOFC diffuse through the wall of the integrated structure and be continuously supplied to the interface with the dense electrolyte layer.

  Therefore, gas permeability is required for the integrated structure wall. In order to satisfy the condition, it is preferable that the wall of the integrated structure has a porosity of 15% or more. At the same time, since the cell integrated unit composed of the integrated structure forms the basic skeleton of the electrochemical reactor, the maximum porosity is preferably 50% or less in order to maintain its strength.

  Also, an integrated structure in which the gas necessary for the electrode reaction of the electrode material constituting the basic skeleton (through hole integrated structure) (air in the SOFC air electrode material, fuel gas in the SOFC fuel electrode material) is composed of the electrode material. The inside of the body wall is not only supplied to the interface with the electrolyte layer as a gas supply path, but also the exposed electrode hole is used as a reaction gas supply path without constructing a cell structure in a part of the through hole. It can also be used.

  In the present invention, it is preferable that the wall of the structure continuously connected from the outer peripheral surface of the integrated structure is used as a gas flow path, and that the gas is a gas containing one or more kinds of fuel or oxygen. Depending on the reaction rate (utilization rate) of the supply gas such as air or fuel, all or a part of the end face of the through hole included in the integrated structure of the through holes made of the electrode material may be closed.

  Here, the electrolyte layer is dense and preferably has a thickness in the range of 1 to 50 microns. Further, in order to suppress the electric resistance of the electrolyte, the thickness is preferably 20 microns or less. Further, the fuel electrode layer is porous and preferably has a thickness in the range of 1 to 100 microns, and more preferably has a thickness of 10 microns or more in order to suppress current collection resistance. The reaction active layer is preferably porous and has a thickness in the range of 1 to 10 microns.

  Next, a cell integrated unit according to the present invention and a method for producing an electrochemical reactor composed thereof will be described. Specifically, the manufacturing method of the electrochemical reactor of the present invention is to produce an integrated structure of through holes made of an electrode material, and to form an electrochemical reaction cell structure on the inner wall surface of all or part of the through holes. It consists of a process of applying a multilayer coating and firing.

The method for producing an electrochemical reactor according to the present invention basically includes the following steps.
(1) A step of shaping an accumulated structure of through-holes made of one electrode material by gel casting or extrusion, and drying or calcining; and
(2) A step of constructing a cell structure on all or a part of inner wall surfaces of the through-holes included in the obtained through-hole integrated structure by a slurry press-fitting method.
Hereafter, the said process is demonstrated in detail.

  First, a binder is added to the powder of the air electrode material and kneaded with water, and the obtained plastic mixture is formed into an integrated structure of predetermined through holes by an extrusion method or the like. Here, it is important to use a cellulosic organic polymer. The amount of the binder added is preferably 5 to 50 g of a cellulose-based organic polymer, preferably 10 to 30 g, per 100 g of the electrode material. In this case, a pore-generating agent such as carbon powder can be added as necessary. The obtained through-hole integrated structure is dried at room temperature. If necessary, it can be calcined to ˜1100 ° C. Thus, an integrated structure of through-holes made of an electrode material having a porosity of 15% or more after firing can be obtained.

  Also, for example, a ceramic slurry for forming an integrated structure of through-holes obtained by mixing 50 to 200 g of electrode material and 1 to 10 g of a gelling agent with 100 g of water is cast into a mold, gelled and dried. After the mold release, it is possible to obtain an integrated structure of through holes made of a predetermined electrode material. In this case, a pore forming agent such as carbon powder can be added to the ceramic slurry as necessary.

  When a plurality of cores arranged in parallel are put in the mold, a plurality of through holes arranged in parallel are formed in the porous molded body. As the shape of the core, various shapes such as a columnar shape and a prismatic shape can be used. Similar to the extrusion molding method, the obtained molded body can be calcined up to 1100 ° C. as necessary. Thus, an integrated structure of through-holes made of an electrode material having a porosity of 15% or more after firing can be produced.

  Next, an electrolyte material and an electrode material are coated so that an electrochemical reaction cell structure is formed on all or part of the inner wall surface of the through-holes included in the integrated structure of through-holes made of electrode materials. Then, by drying and firing, a cell integrated unit having an integrated structure as shown in FIG. 4 can be manufactured, and by joining a plurality of cell integrated units in series or in parallel, electrochemical A reactor can be made.

  As a process of manufacturing a cell integrated unit from an integrated structure of through-holes made of an electrode material, a laminated coating layer necessary for constructing a cell structure is formed for each layer of all or a part of the through-holes. It can be formed using appropriate methods and means, such as a method of repeating coating and baking, or a method of simultaneous baking after coating a plurality of layers.

  As an example of a method for coating the inner wall surface of the through hole, a slurry press-fitting method is exemplified. The slurry is required to have good wettability with the electrode substrate, high adhesion to the substrate after drying, sufficient film thickness and density control that can function as an electrolyte or fuel electrode after firing, and the like.

  Therefore, for 100 to 200 ml of ethanol solvent, 100 g of coating material such as electrolyte layer, fuel electrode layer, electrode reaction active layer, 5 to 20 g of cellulose organic binder, 1 to 5 g of organic dispersant, 2 to 5 g of It is preferable to use a mixture of organic plasticizers. Preferably, a mixing ratio of 100 g of a coating material, 5 to 10 g of a cellulose organic binder, 1 to 2 g of an organic dispersant, and 3 to 5 g of an organic plasticizer is exemplified with respect to 100 to 150 ml of an ethanol solvent. The

  So far, as described in the above-mentioned patent document, slurry coating represented by the dip method has been tried as a coating method for the through-hole. Slurry coating is a technique in which a substrate is directly immersed in a slurry in which raw material powder is dispersed, and a coating film is deposited on the surface of the substrate. If the through-hole size is as large as several millimeters or more, this method is used. Is applicable. In addition, as the through-hole size of the honeycomb type SOFC reported so far, only 3 to 5 mm is selected. However, when the through-hole size proposed in the present invention is 0.1 to 1 mm, bubbles are likely to remain in the through-hole, resulting in an uncoated region, and unnecessary portions being coated with slurry. There was a problem that the slurry remained in the pores more than necessary, and it was difficult to apply.

  On the other hand, the slurry press-fitting method of the present invention is a method of sucking the filled slurry while adjusting the pressure after press-fitting the slurry accurately only into the through-hole using a syringe pump or the like, and the target is 0.1 to Even if the through-hole size is 1 mm, the coating film can be precisely formed on the inner wall surface.

  At that time, depending on the slurry conditions, various coating defects such as uncoated areas, unnecessary coating materials remaining in the through holes, and film density control not being possible, as in the dipping method. (Refer to FIG. 5 shown as a comparative example.) As described above, highly accurate slurry adjustment as described above is important.

  In addition, in the slurry press-fitting method of the present invention, it is possible to form a coat film on all the through holes at the same time, but by simultaneously sealing a part of the through holes, a coat film can be simultaneously formed on all the remaining through holes. Is also possible. The method for forming a coating layer in the present invention is preferably the above slurry press-fitting method, but is not limited to this, and an appropriate coating method can be arbitrarily used. In the present invention, a penetration made of an electrode material is used. The porosity of the hole integrated structure, the size and shape of the through holes, and the thickness and denseness of the deposited film can be arbitrarily set.

The present invention has the following effects.
(1) In the present invention, the electrochemical reaction cell can be highly integrated, and the cell electrode area can be dramatically increased.
(2) The electrochemical reactor can be miniaturized by highly integrating the electrochemical reaction cell using the cell integrated unit of the present invention.
(3) By highly integrating the electrochemical reaction cell using the cell integrated unit of the present invention, high efficiency of the electrochemical reactor can be achieved.
(4) By highly integrating the electrochemical reaction cell using the cell integrated unit of the present invention, the electrochemical reactor can be operated at a low temperature.
(5) By selecting the air electrode material as the basic skeleton of the cell integrated unit, the current collection loss can be greatly reduced.
(6) By the slurry press-fitting method according to the present invention, the through hole size is 0.1 to 1 mm, and all or part of the inner wall surface of the through hole included in the integrated structure of the through hole made of the electrode material A chemical cell structure can be constructed.

  EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited at all by the following Examples.

  In this example, first, an integrated structure of through holes made of an air electrode material was formed according to the following procedure. Nitrocellulose as a binder is added to lanthanum manganate (hereinafter referred to as LSM), which is a kind of air electrode material, kneaded with water and made into a clay, and then an integrated structure of through-holes by extrusion molding. Was molded. The obtained through-hole integrated structure had an outer diameter of 15 mm × 15 mm, a number of holes of 16 × 16, a hole size of 0.8 mm × 0.8 mm, and a wall thickness of 0.2 mm.

  After calcining the molded body for the integrated structure of through-holes made of LSM obtained at 1000 ° C., it was attached to a coating jig and filled with electrolyte slurry in all through-holes with a syringe pump, With the same syringe pump, the filled slurry was sucked and an electrolyte coating was applied to the wall surface of the through hole. The electrolyte-coated LSM compact was co-fired at 1300 ° C. to simultaneously form a dense electrolyte membrane having a thickness of 10 μm on all through-hole wall surfaces.

  The porosity of the integrated structure wall of through-holes made of co-fired LSM was 30% and had a sufficient porosity as an air electrode. The integrated structure of through-holes after co-firing had an outer diameter of 12 mm × 12 mm, a hole size of 0.65 mm × 0.65 mm, and a wall thickness of 0.16 mm.

  Here, the electrolyte slurry used was 100 g of an electrolyte material such as ceria-based oxide (hereinafter referred to as GDC) or scandia-stabilized zirconia (hereinafter referred to as ScSZ), 150 ml of ethanol-toluene mixed solvent, polyvinyl. It was prepared by ball mill mixing of 10 g of butyral binder, 1 g of dispersant, and 5 g of plasticizer.

  The fuel electrode slurry is further coated on all the electrolyte membranes on the inner wall of the through hole by the same method as described above, and then baked at a temperature of 1100 ° C. or higher to form a through hole made of an air electrode as shown in FIG. A cell integrated unit having a hole integrated structure as a basic skeleton was manufactured.

Electrochemical evaluation of LSM (base material, porosity 30%) / GDC (intermediate layer) / ScSZ (electrolyte layer) / NiO-GDC (fuel electrode layer) cell structure produced by the same coating method was performed. As a result, at maximum power density 73mW ^/ cm 2, 700 ℃ at 600 ° C., the maximum power density 230 mW / cm ² was obtained (see FIG. 6). In this material system, when a cell integration unit with a through-hole integrated structure consisting of air electrodes as a basic skeleton is formed, a volume output density of 2 W / cc or higher can be expected even at 600 ° C. An electrochemical reactor can be realized.

  As described above in detail, the present invention electrically connects all or part of the inner wall surface of the through-holes included in the integrated structure of through-holes having a through-hole size of 0.1 to 1 mm and made of an air electrode material. A cell integrated unit used as a structure support body and an air electrode of a chemical reaction cell, and an electrochemical reactor including the cell integrated unit. By the manufacturing method of the present invention, an integrated structure of through-holes made of a small high-performance electrode material Is a basic skeleton, and an electrochemical reactor can be manufactured by joining a plurality of cell integrated units in series or in parallel. In the present invention, by integrating the electrochemical reaction cells having a through-hole size of 0.1 to 1 mm with high density, the cell integrated unit can be reduced in size and efficiency, and can be operated at a low temperature. By improving, it is possible to realize a high-performance electrochemical reactor that can achieve 2 W / cc or more even at 600 ° C. INDUSTRIAL APPLICABILITY The present invention is useful for providing new technologies and new products related to electrochemical reaction systems such as solid oxide fuel cells.

The relationship between the hole size, volume power density, and pressure loss regarding a cell integrated unit is shown. A schematic diagram of a cell integration unit is shown. The relationship between support material and current collection loss is shown. A sectional view of a cell integrated unit and an enlarged view of a cell structure part are shown. Various coating defects are shown. The electrical characteristics of the LSM (base material) / GDC (intermediate layer) / ScSZ (electrolyte layer) / NiO-GDC (fuel electrode layer) cell structure are shown.

Claims (12)

A cell integrated unit having a structure in which an electrochemical cell is formed on an inner wall surface of a through-hole included in an integrated structure of through-holes made of an electrode material, the through-hole size being 0.1 to 1 mm, and the electrode material A structure in which an electrochemical reaction cell is formed on the inner wall surface of all or a part of the through-holes included in the integrated structure of through-holes, and the inner wall surface is used as a structural support and an electrode layer of the electrochemical reaction cell A method of manufacturing a cell integrated unit comprising:
(1) A step of shaping a molded body for an integrated structure of through-holes made of one electrode material by gel casting or extrusion, and drying or calcining,
(2) A step of constructing a cell structure on the inner wall surface of all or part of the through-holes contained in the molded body for the integrated structure of through-holes obtained by the slurry press-fitting method,
A method for producing a cell integrated unit, comprising: A cell integrated unit obtained by the manufacturing method according to claim 1,
1) It is composed of an integrated structure of through-holes made of an electrode material and an electrochemical cell structure constructed on the inner wall surface of the through-holes included in the integrated structure. 2) The size of the through-holes is 0.1 to 0.1. 1 mm, and the inner wall surface is a structure support and an electrode layer of an electrochemical reaction cell. 3) The integrated structure is porous and has a porosity of 15 to 50%. 5) The integrated structure is made of an air electrode material. 5) The electrochemical reaction cell formed on the inner wall surface of all or part of the through holes included in the integrated structure made of the air electrode material is an air electrode. 6) The air electrode reaction active layer material is composed of Ag, La, Sr, Mn, Co, Fe, Sm, Ca, Ba, Ni, and the reaction active layer, the electrolyte layer, and the fuel electrode layer. , Mg elements or oxide compounds containing one or more of these elements Is al arrangement, 7) cells integrated unit which can be less volume output density at 600 ° C. is 2W / cc, characterized by.   The cell integrated unit according to claim 2, wherein all or part of the end surface of the through hole included in the integrated structure is closed.   The cell integration according to claim 2, wherein the inner wall coat layer has an air electrode reaction active layer thickness of 1 to 10 microns, an electrolyte layer thickness of 1 to 50 microns, and a fuel electrode layer thickness of 1 to 100 microns. unit.   The cell integrated unit according to claim 2, wherein a wall of the structure that continues from the outer peripheral surface of the integrated structure is used as a gas flow path.   The cell integrated unit according to claim 4, wherein the gas is a gas containing one or more kinds of fuel or oxygen. The electrolyte layer, ceria based _{oxide: Ce 1-x Ln x O} 2-x / 2 ( although, Ln is La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb , Lu, Y, and x is 0.05 or more and 0.50 or less), scandia-stabilized zirconia oxide: a mol% Sc ₂ O ₃ -b mol% CeO ₂ -c mol% ZrO ₂ (Where a is 8 or more and 15 or less, b is 0 or more and 2 or less, and a + b + c = 100), lanthanum gallate oxide: La _1-m Sr _m Ga _1-n Mg _n O ₃ (where m is 0.05 The cell integrated unit according to claim 2, wherein the cell integrated unit is one type of 0.3 or less and n is 0 or more and 0.3 or less), or two or more types of composites.   The said fuel electrode layer material is comprised from the oxide compound containing the element of Ni, Cu, Pt, Pd, Au, Ru, Co, La, Sr, Ti, or one or more of these elements. Cell integration unit.   The cell integrated unit according to claim 8, wherein the fuel electrode layer material is a composite with the electrolyte material according to claim 7.   The electrode layer includes an active auxiliary material, and the active auxiliary material includes Pt, Pd, Ag, Ba, Sr, Ca, Mg, K, Na, Mn, Fe, Co, Ni, Cu, Zn, Ti, and Al. 3. The cell integrated unit according to claim 2, wherein the cell integrated unit is a metal containing at least one kind of elements of Ga, Nb, Ta, V, and La, or an oxide containing one or more kinds of these elements. The cell integrated unit according to claim 2 , wherein the air electrode reaction active layer material is a composite containing one or more of the electrolyte layer material according to claim 7 or the active auxiliary material according to claim 10. An electrochemical reactor comprising the cell integrated unit according to any one of claims 2 to 11.